Structure of the Elastin-Contractile Units in the Thoracic Aorta and How Genes That Cause Thoracic Aortic Aneurysms and Dissections Disrupt This Structure.

PubMed

Karimi, Ashkan; Milewicz, Dianna M

2016-01-01

The medial layer of the aorta confers elasticity and strength to the aortic wall and is composed of alternating layers of smooth muscle cells (SMCs) and elastic fibres. The SMC elastin-contractile unit is a structural unit that links the elastin fibres to the SMCs and is characterized by the following: (1) layers of elastin fibres that are surrounded by microfibrils; (2) microfibrils that bind to the integrin receptors in focal adhesions on the cell surface of the SMCs; and (3) SMC contractile filaments that are linked to the focal adhesions on the inner side of the membrane. The genes that are altered to cause thoracic aortic aneurysms and aortic dissections encode proteins involved in the structure or function of the SMC elastin-contractile unit. Included in this gene list are the genes encoding protein that are structural components of elastin fibres and microfibrils, FBN1, MFAP5, ELN, and FBLN4. Also included are genes that encode structural proteins in the SMC contractile unit, including ACTA2, which encodes SMC-specific α-actin and MYH11, which encodes SMC-specific myosin heavy chain, along with MYLK and PRKG1, which encode kinases that control SMC contraction. Finally, mutations in the gene encoding the protein linking integrin receptors to the contractile filaments, FLNA, also predispose to thoracic aortic disease. Thus, these data suggest that functional SMC elastin-contractile units are important for maintaining the structural integrity of the aorta. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Detection of altered extracellular matrix in surface layers of unstable carotid plaque: an optical spectroscopy, birefringence and microarray genetic analysis.

PubMed

Korol, Renee M; Canham, Peter B; Liu, Li; Viswanathan, Kasinath; Ferguson, Gary G; Hammond, Rob R; Finlay, Helen M; Baker, Henry V; Lopez, Cecilia; Lucas, Alexandra R

2011-01-01

Erosion and rupture of surface layers in atherosclerotic plaque can cause heart attack and stroke; however, changes in luminal surface composition are incompletely defined. Laser-induced fluorescence spectroscopy (LIFS), with limited tissue penetration, was used to investigate the surface of unstable carotid plaque and correlated with microscopy, birefringence and gene expression. Arterial matrix collagens I, III and elastin were assessed in unstable plaques (n = 25) and reference left internal mammary arteries (LIMA, n = 10). LIFS in addition to selective histological staining with picrosirius red, Movat pentachrome and immunostaining revealed decreased elastin and increased collagen I and III (P < 0.05) in carotid plaque when compared with LIMA. Within plaque, collagen I was elevated in the internal carotid region versus the common carotid region. Polarized light microscopy detected layers of aligned collagen and associated mechanical rigidity of the fibrous cap. Microarray analysis of three carotid and three LIMA specimens confirmed up-regulation of collagen I, III and IV, lysyl oxidase and MMP-12. In conclusion, LIFS analysis coupled with microscopy revealed marked regional differences in collagen I, III and elastin in surface layers of carotid plaque; indicative of plaque instability. Birefringence measurements demonstrated mechanical rigidity and weakening of the fibrous cap with complementary changes in ECM gene expression. © 2011 The Authors. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

Elastin as a self-organizing biomaterial: use of recombinantly expressed human elastin polypeptides as a model for investigations of structure and self-assembly of elastin.

PubMed

Keeley, Fred W; Bellingham, Catherine M; Woodhouse, Kimberley A

2002-02-28

Elastin is the major extracellular matrix protein of large arteries such as the aorta, imparting characteristics of extensibility and elastic recoil. Once laid down in tissues, polymeric elastin is not subject to turnover, but is able to sustain its mechanical resilience through thousands of millions of cycles of extension and recoil. Elastin consists of ca. 36 domains with alternating hydrophobic and cross-linking characteristics. It has been suggested that these hydrophobic domains, predominantly containing glycine, proline, leucine and valine, often occurring in tandemly repeated sequences, are responsible for the ability of elastin to align monomeric chains for covalent cross-linking. We have shown that small, recombinantly expressed polypeptides based on sequences of human elastin contain sufficient information to self-organize into fibrillar structures and promote the formation of lysine-derived cross-links. These cross-linked polypeptides can also be fabricated into membrane structures that have solubility and mechanical properties reminiscent of native insoluble elastin. Understanding the basis of the self-organizational ability of elastin-based polypeptides may provide important clues for the general design of self-assembling biomaterials.

Molecular, histologic, and trace mineral characterization of metacarpophalangeal and metatarsophalangeal joint hyperextension in juvenile llamas.

PubMed

Semevolos, Stacy A; Reed, Shannon K

2011-04-01

To evaluate molecular and histologic characteristics of the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) and assess trace-mineral concentrations in serum, liver, and hair of juvenile llamas with metacarpophalangeal and metatarsophalangeal joint hyperextension. 12 juvenile llamas (6 with bilateral hyperextension of metacarpophalangeal joints, metatarsophalangeal joints, or both and 6 clinically normal control llamas). Radiography and ultrasonography of metacarpophalangeal and metatarsophalangeal regions were performed. Llamas were euthanized, and SDFT, DDFT, and SL samples were collected for histologic evaluation of collagen and elastin content and orientation, proteoglycan content, and collagen type III immunohistochemistry. Total RNA was isolated from SL tissue, and gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 was evaluated via real-time quantitative reverse transcriptase PCR assay. Liver, serum, and hair samples were evaluated for trace mineral content. Collagen type III gene expression and proteoglycan content were significantly increased in SL samples of affected juvenile llamas, compared with those of control llamas. No difference was detected in collagen and elastin content and orientation or in gene expression of collagen type I, lysyl oxidase, or matrix metalloproteinase-13 between groups. Affected llamas had significantly increased serum molybdenum and decreased liver cobalt concentrations, compared with values for control llamas. Increased collagen type III gene expression and proteoglycan content in SL samples of affected juvenile llamas provided evidence of ongoing SL matrix repair. Trace mineral differences may have been attributable to dietary imbalances in affected llamas.

GABA promotes elastin synthesis and elastin fiber formation in normal human dermal fibroblasts (HDFs).

PubMed

Uehara, Eriko; Hokazono, Hideki; Hida, Mariko; Sasaki, Takako; Yoshioka, Hidekatsu; Matsuo, Noritaka

2017-06-01

The multiple physiological effects of γ-aminobutyric acid (GABA) as a functional food component have been recently reported. We previously reported that GABA upregulated the expression of type I collagen in human dermal fibroblasts (HDFs), and that oral administration of GABA significantly increased skin elasticity. However, details of the regulatory mechanism still remain unknown. In this study, we further examined the effects of GABA on elastin synthesis and elastin fiber formation in HDFs. Real-time PCR indicated that GABA significantly increased the expression of tropoelastin transcript in a dose-dependent manner. Additionally, the expression of fibrillin-1, fibrillin-2, and fibulin-5/DANCE, but not lysyl oxidase and latent transforming factor-β-binding protein 4, were also significantly increased in HDFs. Finally, immunohistochemical analysis confirmed that treatment with GABA dramatically increased the formation of elastic fibers in HDFs. Taken together, our results showed that GABA improves skin elasticity in HDFs by upregulating elastin synthesis and elastin fiber formation.

Pentagalloyl glucose increases elastin deposition, decreases reactive oxygen species and matrix metalloproteinase activity in pulmonary fibroblasts under inflammatory conditions.

PubMed

Parasaram, Vaideesh; Nosoudi, Nasim; Chowdhury, Aniqa; Vyavahare, Naren

2018-04-30

Emphysema is characterized by degradation of lung alveoli that leads to poor airflow in lungs. Irreversible elastic fiber degradation by matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity leads to loss of elasticity and drives the progression of this disease. We investigated if a polyphenol, pentagalloyl glucose (PGG) can increase elastin production in pulmonary fibroblasts. We also studied the effect of PGG treatment in reducing MMP activity and ROS levels in cells. We exposed rat pulmonary fibroblasts to two different types of inflammatory environments i.e., tumor necrosis factor-α (TNF-α) and cigarette smoke extract (CSE) to mimic the disease. Parameters like lysyl oxidase (LOX) and elastin gene expression, MMP-9 activity in the medium, lysyl oxidase (LOX) activity and ROS levels were studied to assess the effect of PGG on pulmonary fibroblasts. CSE inhibited lysyl oxidase (LOX) enzyme activity that resulted in a decreased elastin formation. Similarly, TNF-α treated cells showed less elastin in the cell layers. Both these agents caused increase in MMP activity and ROS levels in cells. However, when supplemented with PGG treatment along with these two inflammatory agents, we saw a significant increase in elastin deposition, reduction in both MMP activity and ROS levels. Thus PGG, which has anti-inflammatory, anti-oxidant properties coupled with its ability to aid in elastic fiber formation, can be a multifunctional drug to potentially arrest the progression of emphysema. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of birth trauma and estrogen on urethral elastic fibers and elastin expression.

PubMed

Lin, Guiting; Ning, Hongxiu; Wang, Guifang; Banie, Lia; Lue, Tom F; Lin, Ching-Shwun

2010-10-01

To investigate the effects of birth trauma and estrogen on urethral elastic fibers and elastin expression. Pregnant rats were subjected to sham operation (Delivery-only), DVDO (delivery, vaginal distension and ovariectomy), or DVDO + E₂ (estrogen). At 2, 4, 8, or 12 weeks, their urethras were harvested for elastic fiber staining and reverse transcription-polymerase chain reaction analysis. Urethral cells were treated with transforming growth factor- β1 (TGFβ1) and/or estrogen and analyzed for elastin mRNA expression. Urethral cells were also examined for the activities of Smad1- and Smad3/4-responsive elements in response to TGFβ1 and estrogen. At 8 weeks post-treatment, the urethras of DVDO rats had fewer and shorter elastic fibers when compared with Delivery-only rats, and those of DVDO + E₂ rats had fewer and shorter elastic fibers when compared with DVDO rats. Elastin mRNA was expressed at low levels in Delivery-only rats and at increasingly higher levels in DVDO rats at 2, 4, and 8 weeks but at sharply lower levels in DVDO + E₂ rats when compared with DVDO rats at 8 weeks. Urethral cells expressed increasingly higher levels of elastin mRNA in response to increasing concentrations of TGFβ1 up to 1 ng/mL. At this TGFβ1 concentration, urethral cells expressed significantly lower levels of elastin mRNA when treated with estrogen before or after TGFβ1 treatment. Both Smad1- and Smad3/4-responsive elements were activated by TGFβ1 and such activation was suppressed by estrogen. Birth trauma appears to activate urethral elastin expression via TGFβ1 signaling. Estrogen interferes with this signaling, resulting in improper assembly of elastic fibers. Copyright © 2010 Elsevier Inc. All rights reserved.

Dynamic expression of chymotrypsin-like elastase 1 over the course of murine lung development

PubMed Central

Liu, Sheng; Young, Sarah Marie

2014-01-01

Postnatal lung development requires coordination of three processes (surface area expansion, microvascular growth, and matrix remodeling). Because normal elastin structure is important for lung morphogenesis, because physiological remodeling of lung elastin has never been defined, and because elastin remodeling is angiogenic, we sought to test the hypothesis that, during lung development, elastin is remodeled in a defined temporal-spatial pattern, that a novel protease is associated with this remodeling, and that angiogenesis is associated with elastin remodeling. By elastin in situ zymography, lung elastin remodeling increased 24-fold between embryonic day (E) 15.5 and postnatal day (PND) 14. Remodeling was restricted to major vessels and airways on PND1 with a sevenfold increase in alveolar wall elastin remodeling from PND1 to PND14. By inhibition assays and literature review, we identified chymotrypsin-like elastase 1 (CELA1) as a potential mediator of elastin remodeling. CELA1 mRNA levels increased 12-fold from E15.5 to PND9, and protein levels increased 3.4-fold from E18.5 to PND9. By costaining experiments, the temporal-spatial pattern of CELA1 expression matched that of elastin remodeling, and 58–85% of CELA1+ cells were <10 μm from an elastase signal. An association between elastin remodeling and angiogenesis was tested by similar methods. At PND7 and PND14, 60–95% of angiogenin+ cells were associated with elastin remodeling. Both elastase inhibition and CELA1 silencing impaired angiogenesis in vitro. Our data defines the temporal-spatial pattern of elastin remodeling during lung development, demonstrates an association of this remodeling with CELA1, and supports a role for elastin remodeling in regulating angiogenesis. PMID:24793170

High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

PubMed

Bahniuk, Markian S; Alshememry, Abdullah K; Unsworth, Larry D

2016-12-01

The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.

An Investigation of Voice Quality in Individuals with Inherited Elastin Gene Abnormalities

ERIC Educational Resources Information Center

Watts, Christopher R.; Awan, Shaheen N.; Marler, Jeffrey A.

2008-01-01

The human elastin gene (ELN) is responsible for the generation of elastic fibres in the extracellular matrix of connective tissue throughout the body, including the vocal folds. Individuals with Supravalvular aortic stenosis (SVAS) and Williams syndrome (WS) lack one normal ELN allele due to heterozygous ELN abnormalities, resulting in a…

Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

PubMed

Preil, Simone Andrea Rørdam; Thorsen, Anne-Sofie Faarvang; Christiansen, Anne Lindegaard; Poulsen, Mikael Kjær; Karsdal, Morten Asser; Leeming, Diana Julie; Rasmussen, Lars Melholt

2017-11-01

Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM. Blood samples from 302 type 2 diabetic patients were analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index. T2DM patients with peripheral arterial disease (low ankle-brachial index) (PAD) display higher levels of MMP-2 and ELM compared to patients without PAD. However, none of the proteins or degradation products correlated with myocardial ischemia or a combined measure of CVD-signs, including myocardial ischemia, increased carotid thickness and decreased ankle-brachial blood pressure. Our results suggest that the diabetic environment affects the circulating amounts of MMP-2 and ELM in patients with PAD. However, the same connection could not be seen in diabetic patients with CVD broadly identified in three vascular territories. LOX and ELM-2 did not correlate to any type of CVD. Overall, serum levels of elastin-related molecules are only remotely related to CVD in type 2 diabetes.

Systemic elastin degradation in chronic obstructive pulmonary disease.

PubMed

Maclay, John D; McAllister, David A; Rabinovich, Roberto; Haq, Imran; Maxwell, Scott; Hartland, Stephen; Connell, Martin; Murchison, John T; van Beek, Edwin J R; Gray, Robert D; Mills, Nicholas L; Macnee, William

2012-07-01

Development of emphysema and vascular stiffness in chronic obstructive pulmonary disease (COPD) may be due to a common mechanism of susceptibility to pulmonary and systemic elastin degradation. To investigate whether patients with COPD have evidence of systemic elastin degradation in the skin. The authors measured cutaneous elastin degradation using immunohistochemistry (percentage area of elastin fibres) in sun-exposed (exposed) and non-sun-exposed (non-exposed) skin biopsies in 16 men with COPD and 15 controls matched for age and cigarette smoke exposure. Quantitative PCR of matrix metalloproteinase (MMP)-2, -9, -12 and tissue inhibitor of metalloproteinase-1 mRNA and zymography for protein expression of MMP-2 and -9 were performed on homogenised skin. Arterial stiffness and emphysema severity were measured using carotid-femoral pulse wave velocity and quantitative CT scanning. Skin elastin degradation was greater in exposed and non-exposed skin of patients with COPD compared with controls (exposed, mean (SD); 43.5 (12.1)% vs 26.3 (6.9)%, p<0.001; non-exposed 22.4 (5.2)% vs 18.1 (4.3)%, p=0.02). Cutaneous expression of MMP-9 mRNA and proMMP-9 concentrations was increased in exposed skin of COPD patients (p=0.004 and p=0.02, respectively) and was also associated with increased skin elastin degradation (r=0.62, p<0.001 and r=0.47, p=0.01, respectively). In the entire cohort of ex-smokers, cutaneous elastin degradation was associated with emphysema severity, FEV(1) and pulse wave velocity. Patients with COPD have increased skin elastin degradation compared with controls, which is related to emphysema severity and arterial stiffness. Systemic elastin degradation due to increased proteolytic activity may represent a novel shared mechanism for the pulmonary, vascular and cutaneous features of COPD.

MicroRNA-29 facilitates transplantation of bone marrow-derived mesenchymal stem cells to alleviate pelvic floor dysfunction by repressing elastin.

PubMed

Jin, Minfei; Wu, Yuelin; Wang, Jun; Ye, Weiping; Wang, Lei; Yin, Peipei; Liu, Wei; Pan, Chenhao; Hua, Xiaolin

2016-11-17

Pelvic floor dysfunction (PFD) is a condition affecting many women worldwide, with symptoms including stress urinary incontinence (SUI) and pelvic organ prolapse (POP). We have previously demonstrated stable elastin-expressing bone marrow-derived mesenchymal stem cells (BMSCs) attenuated PFD in rats, and aim to further study the effect of microRNA-29a-3p regulation on elastin expression and efficacy of BMSC transplantation therapy. We inhibited endogenous microRNA-29a-3p in BMSCs and investigated its effect on elastin expression by RT-PCR and Western blot. MicroRNA-29-inhibited BMSCs were then transplanted into PFD rats, accompanied by sustained release of bFGF using formulated bFGF in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP), followed by evaluation of urodynamic tests. MicroRNA-29a-3p inhibition resulted in upregulated expression and secretion of elastin in in vitro culture of BMSCs. After co-injection with PLGA-loaded bFGF NP into the PFD rats in vivo, microRNA-29a-3p-inhibited BMSCs significantly improved the urodynamic test results. Our multidisciplinary study, combining microRNA biology, genetically engineered BMSCs, and nanoparticle technology, provides an excellent stem cell-based therapy for repairing connective tissues and treating PFD.

Elastin: a possible genetic biomarker for more severe ligament injuries in elite soccer. A pilot study

PubMed Central

Artells, Rosa; Pruna, Ricard; Dellal, Alexandre; Maffulli, Nicola

2016-01-01

Summary Background The study of new genetic biomarkers in genes related to connective tissue repair and regeneration may help to identify individuals with greater predisposition to injury, who may benefit from targeted preventive measures, and those who require longer recovery time following a muscle, ligament or tendon injury. The present study investigated whether single nucleotide polymorphisms of the Elastin gene could be related to MCL injury. Methods 60 top class football players were studied to identify single nucleotide polymorphisms for the Elastin (ELN) gene using Allelic Discrimination analysis. Each player was followed for 7 seasons, and each MCL injury was noted. Results Ligament injury rate, severity and recovery time are related to specific genotypes observed in the elastin gene, especially the ELN-AA (16 MCL) and the ELN-AG (3 MCL). Players with the ELN-GG genotype sustained no MCL injury during the 7 seasons of the study. Conclusions The identification of polymorphisms in the ELN gene may be used as a novel tool to better define an athlete’s genotype, and help to plan training and rehabilitation programmes to prevent or minimize MCL ligament injuries, and optimize the therapeutic and rehabilitation process after soft tissue injuries, and manage the workloads during trainings and matches. PMID:27900291

Lysyl Oxidase Induces Vascular Oxidative Stress and Contributes to Arterial Stiffness and Abnormal Elastin Structure in Hypertension: Role of p38MAPK.

PubMed

Martínez-Revelles, Sonia; García-Redondo, Ana B; Avendaño, María S; Varona, Saray; Palao, Teresa; Orriols, Mar; Roque, Fernanda R; Fortuño, Ana; Touyz, Rhian M; Martínez-González, Jose; Salaices, Mercedes; Rodríguez, Cristina; Briones, Ana M

2017-09-01

Vascular stiffness, structural elastin abnormalities, and increased oxidative stress are hallmarks of hypertension. Lysyl oxidase (LOX) is an elastin crosslinking enzyme that produces H 2 O 2 as a by-product. We addressed the interplay between LOX, oxidative stress, vessel stiffness, and elastin. Angiotensin II (Ang II)-infused hypertensive mice and spontaneously hypertensive rats (SHR) showed increased vascular LOX expression and stiffness and an abnormal elastin structure. Mice over-expressing LOX in vascular smooth muscle cells (TgLOX) exhibited similar mechanical and elastin alterations to those of hypertensive models. LOX inhibition with β-aminopropionitrile (BAPN) attenuated mechanical and elastin alterations in TgLOX mice, Ang II-infused mice, and SHR. Arteries from TgLOX mice, Ang II-infused mice, and/or SHR exhibited increased vascular H 2 O 2 and O 2 .- levels, NADPH oxidase activity, and/or mitochondrial dysfunction. BAPN prevented the higher oxidative stress in hypertensive models. Treatment of TgLOX and Ang II-infused mice and SHR with the mitochondrial-targeted superoxide dismutase mimetic mito-TEMPO, the antioxidant apocynin, or the H 2 O 2 scavenger polyethylene glycol-conjugated catalase (PEG-catalase) reduced oxidative stress, vascular stiffness, and elastin alterations. Vascular p38 mitogen-activated protein kinase (p38MAPK) activation was increased in Ang II-infused and TgLOX mice and this effect was prevented by BAPN, mito-TEMPO, or PEG-catalase. SB203580, the p38MAPK inhibitor, normalized vessel stiffness and elastin structure in TgLOX mice. We identify LOX as a novel source of vascular reactive oxygen species and a new pathway involved in vascular stiffness and elastin remodeling in hypertension. LOX up-regulation is associated with enhanced oxidative stress that promotes p38MAPK activation, elastin structural alterations, and vascular stiffness. This pathway contributes to vascular abnormalities in hypertension. Antioxid. Redox Signal. 27, 379-397.

Lysyl Oxidase Induces Vascular Oxidative Stress and Contributes to Arterial Stiffness and Abnormal Elastin Structure in Hypertension: Role of p38MAPK

PubMed Central

Martínez-Revelles, Sonia; García-Redondo, Ana B.; Avendaño, María S.; Varona, Saray; Palao, Teresa; Orriols, Mar; Roque, Fernanda R.; Fortuño, Ana; Touyz, Rhian M.; Martínez-González, Jose; Salaices, Mercedes

2017-01-01

Abstract Aims: Vascular stiffness, structural elastin abnormalities, and increased oxidative stress are hallmarks of hypertension. Lysyl oxidase (LOX) is an elastin crosslinking enzyme that produces H2O2 as a by-product. We addressed the interplay between LOX, oxidative stress, vessel stiffness, and elastin. Results: Angiotensin II (Ang II)-infused hypertensive mice and spontaneously hypertensive rats (SHR) showed increased vascular LOX expression and stiffness and an abnormal elastin structure. Mice over-expressing LOX in vascular smooth muscle cells (TgLOX) exhibited similar mechanical and elastin alterations to those of hypertensive models. LOX inhibition with β-aminopropionitrile (BAPN) attenuated mechanical and elastin alterations in TgLOX mice, Ang II-infused mice, and SHR. Arteries from TgLOX mice, Ang II-infused mice, and/or SHR exhibited increased vascular H2O2 and O2.− levels, NADPH oxidase activity, and/or mitochondrial dysfunction. BAPN prevented the higher oxidative stress in hypertensive models. Treatment of TgLOX and Ang II-infused mice and SHR with the mitochondrial-targeted superoxide dismutase mimetic mito-TEMPO, the antioxidant apocynin, or the H2O2 scavenger polyethylene glycol-conjugated catalase (PEG-catalase) reduced oxidative stress, vascular stiffness, and elastin alterations. Vascular p38 mitogen-activated protein kinase (p38MAPK) activation was increased in Ang II-infused and TgLOX mice and this effect was prevented by BAPN, mito-TEMPO, or PEG-catalase. SB203580, the p38MAPK inhibitor, normalized vessel stiffness and elastin structure in TgLOX mice. Innovation: We identify LOX as a novel source of vascular reactive oxygen species and a new pathway involved in vascular stiffness and elastin remodeling in hypertension. Conclusion: LOX up-regulation is associated with enhanced oxidative stress that promotes p38MAPK activation, elastin structural alterations, and vascular stiffness. This pathway contributes to vascular abnormalities in hypertension. Antioxid. Redox Signal. 27, 379–397. PMID:28010122

Synthesis and Structural Characterization of Reflectin Proteins

DTIC Science & Technology

2012-02-29

constructs of interest included a reflectin 1a domain 3 (D3) monomer, a domain 3 dimer, subdomain peptides, recombinant reflectin 1b, an elastin -reflectin...diblock copolymer, and an elastin -reflectin-GFP fusion protein. After construction of the sequences of interest at the DNA level, protein expression...characterization was performed. The unique spectral properties associated with recombinant reflectin protein materials make elastin -reflectin

RNA interference targeting carbohydrate sulfotransferase 3 diminishes macrophage accumulation, inhibits MMP-9 expression and promotes lung recovery in murine pulmonary emphysema.

PubMed

Kai, Yoshiro; Tomoda, Koichi; Yoneyama, Hiroyuki; Yoshikawa, Masanori; Kimura, Hiroshi

2015-12-09

Chondroitin sulfate proteoglycans are an important mediators in inflammation and leukocyte trafficking. However, their roles in pulmonary emphysema have not been explored. In a murine model of elastase-induced pulmonary emphysema, we found increased carbohydrate sulfotransferase 3 (CHST3), a specific enzyme that synthesizes chondroitin 6-sulfate proteoglycan (C6SPG). To elucidate the role of C6SPG, we investigated the effect of small interfering RNA (siRNA) targeting CHST3 that inhibits C6SPG-synthesis on the pathogenesis of pulmonary emphysema. Mice were intraperitoneally injected with CHST3 siRNA or negative control siRNA on day0 and 7 after intratracheal instillation of elastase. Histology, respiratory function, glycosaminoglycans (GAGs) content, bronchoalveolar lavage (BAL), elastin staining and gene expressions of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-9 mRNA were evaluated on day7 and/or day21. CHST3 mRNA increased at day 7 and decreased thereafter in lung. CHST3 siRNA successfully inhibited the expression of CHST3 mRNA throughout the study and this was associated with significant reduction of GAGs and C6SPG. Airway destruction and respiratory function were improved by the treatment with CHST3 siRNA. CHST3 siRNA reduced the number of macrophages both in BAL and lung parenchyma and also suppressed the increased expressions of TNF-α and MMP-9 mRNA. Futhermore, CHST3 siRNA improved the reduction of the elastin in the alveolar walls. CHST3 siRNA diminishes accumulation of excessive macrophages and the mediators, leading to accelerate the functional recovery from airway damage by repair of the elastin network associated with pulmonary emphysema.

Use of versican variant V3 and versican antisense expression to engineer cultured human skin containing increased content of insoluble elastin.

PubMed

Merrilees, Mervyn J; Falk, Ben A; Zuo, Ning; Dickinson, Michelle E; May, Barnaby C H; Wight, Thomas N

2017-01-01

Skin substitutes for repair of dermal wounds are deficient in functional elastic fibres. We report that the content of insoluble elastin in the dermis of cultured human skin can be increased though the use of two approaches that enhance elastogenesis by dermal fibroblasts, forced expression of versican variant V3, which lacks glycosaminoglycan (GAG) chains, and forced expression of versican antisense to decrease levels of versican variant V1 with GAG chains. Human dermal fibroblasts transduced with V3 or anti-versican were cultured under standard conditions over a period of 4 weeks to produce dermal sheets, with growth enhanced though multiple seedings for the first 3 weeks. Human keratinocytes, cultured in supplemented media, were added to the 4-week dermal sheets and the skin layer cultured for a further week. At 5 weeks, keratinocytes were multilayered and differentiated, with desmosome junctions thoughout and keratin deposits in the upper squamous layers. The dermal layer was composed of layered fibroblasts surrounded by extracellular matrix of collagen bundles and, in control cultures, small scattered elastin deposits. Forced expression of V3 and versican antisense slowed growth, decreased versican V1 expression, increased tropoelastin expression and/or the deposition of large aggregates of insoluble elastin in the dermal layer, and increased tissue stiffness, as measured by nano-indentation. Skin sheets were also cultured on Endoform Dermal Template™, the biodegradable wound dressing made from the lamina propria of sheep foregut. Skin structure and the enhanced deposition of elastin by forced expression of V3 and anti-versican were preserved on this supportive substrate. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Racial Differences in the Extracellular Matrix and Histone Acetylation of the Lamina Cribrosa and Peripapillary Sclera.

PubMed

Park, Hae-Young Lopilly; Kim, Jie Hyun; Jung, Younhea; Park, Chan Kee

2017-08-01

We investigated the extracellular matrix (ECM) of the lamina cribrosa (LC) and peripapillary sclera (PPS) and compared histone acetylation and related enzymes to identify racial differences between Korean and Caucasian donor eyes. Posterior segment tissues were obtained from 30 Caucasian donors and 42 age and axial length-matched Korean donors. Histone modification was assessed for histone deacetylase (HDAC) 2, HDAC3, and acetylated histone H3. The promoter regions of the major ECM in the LC and PPS including collagen type I and III, and elastic fiber components (elastin and fibrillin-1) and lysyl oxidase enzymes including lysyl oxidase-like 1 and 2 (LOXL2) were evaluated by chromatin immunoprecipitation (ChIP) assay. Protein and mRNA expression of major ECM components were assessed using real-time polymerase chain reaction analysis, western blot analysis, and immunohistochemical staining. HDAC2 and HDAC3 expression levels were decreased and acetylated histone H3 was increased in the LC and PPS of Korean eyes than Caucasian eyes. The promoter regions of LOXL2, elastin, and fribrillin-1 genes were highly acetylated in Korean LC. Expression of LOXL2 and elastic fiber components (elastin and fibrillin-1) were significantly increased in Korean LC and PPS than Caucasians according to the real-time polymerase chain reaction, western blot analyses, and quantification of elastic fiber staining. Histone acetylation status differed in the promoter regions of the elastic fiber components and LOXL2 in the LC and PPS according to race. Further study to reveal the association with these findings to the pathogenesis of glaucoma in Korean eyes is needed.

Impact of elastin incorporation into electrochemically aligned collagen fibers on mechanical properties and smooth muscle cell phenotype.

PubMed

Nguyen, Thuy-Uyen; Bashur, Chris A; Kishore, Vipuil

2016-03-17

Application of tissue-engineered vascular grafts (TEVGs) for the replacement of small-diameter arteries is limited due to thrombosis and intimal hyperplasia. Previous studies have attempted to address the limitations of TEVGs by developing scaffolds that mimic the composition (collagen and elastin) of native arteries to better match the mechanical properties of the graft with the native tissue. However, most existing scaffolds do not recapitulate the aligned topography of the collagen fibers found in native vessels. In the current study, based on the principles of isoelectric focusing, two different types of elastin (soluble and insoluble) were incorporated into highly oriented electrochemically aligned collagen (ELAC) fibers and the effect of elastin incorporation on the mechanical properties of the ELAC fibers and smooth muscle cell (SMC) phenotype was investigated. The results indicate that elastin incorporation significantly decreased the modulus of ELAC fibers to converge upon that of native vessels. Further, a significant increase in yield strain and decrease in Young's modulus was observed on all fibers post SMC culture compared with before the culture. Real-time polymerase chain reaction results showed a significant increase in the expression of α-smooth muscle actin and calponin on ELAC fibers with insoluble elastin, suggesting that incorporation of insoluble elastin induces a contractile phenotype in SMCs after two weeks of culture on ELAC fibers. Immunofluorescence results showed that calponin expression increased with time on all fibers. In conclusion, insoluble elastin incorporated ELAC fibers have the potential to be used for the development of functional TEVGs for the repair and replacement of small-diameter arteries.

Insights into the role of elastin in vocal fold health and disease

PubMed Central

Moore, Jaime

2011-01-01

Elastic fibers are large, complex and surprisingly poorly understood extracellular matrix (ECM) macromolecules. The elastin fiber, generated from a single human gene - elastin (ELN), is a self assembling integral protein that endows critical mechanic proprieties to elastic tissues and organs such as the skin, lungs, and arteries. The biology of elastic fibers is complex because they have multiple components, a tightly regulated developmental deposition, a multi-step hierarchical assembly and unique biomechanical functions. Elastin is present in vocal folds, where it plays a pivotal role in the quality of phonation. This review article provides an overview of the genesis of elastin and its wide- ranging structure and function. Specific distribution within the vocal fold lamina propria across the lifespan in normal and pathological states and its contribution to vocal fold biomechanics will be examined. Elastin and elastin-derived molecules are increasingly investigated for their application in tissue engineering. The properties of various elastin– based materials will be discussed and their current and future applications evaluated. A new level of understanding of the biomechanical properties of vocal fold elastin composites and their molecular basis should lead to new strategies for elastic fiber repair and regeneration in aging and disease. PMID:21708449

Coenzyme Q(10) enhances dermal elastin expression, inhibits IL-1α production and melanin synthesis in vitro.

PubMed

Zhang, M; Dang, L; Guo, F; Wang, X; Zhao, W; Zhao, R

2012-06-01

Coenzyme Q(10) (CoQ(10) ) is a well-known antioxidant and has been used in many skincare products for anti-ageing purpose. However, the molecular mechanisms of CoQ(10) function in skin cells are not fully understood. In this paper, we compared the effects of CoQ(10) on primary human dermal fibroblasts from three individuals, including adult. We demonstrated that CoQ(10) treatment promoted proliferation of fibroblasts, increased type IV collagen expression and reduced UVR-induced matrix metalloproteinases-1 (MMP-1) level in embryonic and adult cells. In addition, CoQ(10) treatment increased elastin gene expression in cultured fibroblasts and significantly decreased UVR-induced IL-1α production in HaCat cells. Taken together, CoQ(10) presented anti-ageing benefits against intrinsic ageing as well as photo damage. Interestingly, CoQ(10) was able to inhibit tyrosinase activity, resulting in reduced melanin content in B16 cells. Thus, CoQ(10) may have potential depigmentation effects for skincare. © 2012 Space Biology Research & Technology Center, CASC. ICS © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Human umbilical cord-derived mesenchymal stem cells protect from hyperoxic lung injury by ameliorating aberrant elastin remodeling in the lung of O2-exposed newborn rat.

PubMed

Hou, Chen; Peng, Danyi; Gao, Li; Tian, Daiyin; Dai, Jihong; Luo, Zhengxiu; Liu, Enmei; Chen, Hong; Zou, Lin; Fu, Zhou

2018-01-08

The incidence and mortality rates of bronchopulmonary dysplasia (BPD) remain very high. Therefore, novel therapies are imminently needed to improve the outcome of this disease. Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) show promising therapeutic effects on oxygen-induced model of BPD. In our experiment, UC-MSCs were intratracheally delivered into the newborn rats exposed to hyperoxia, a well-established BPD model. This study demonstrated that UC-MSCs reduce elastin expression stimulated by 90% O 2 in human lung fibroblasts-a (HLF-a), and inhibit HLF-a transdifferentiation into myofibroblasts. In addition, the therapeutic effects of UC-MSCs in neonatal rats with BPD, UC-MSCs could inhibit lung elastase activity and reduce aberrant elastin expression and deposition in the lung of BPD rats. Overall, this study suggested that UC-MSCs could ameliorate aberrant elastin expression in the lung of hyperoxia-induced BPD model which may be associated with suppressing increased TGFβ1 activation. Copyright © 2017. Published by Elsevier Inc.

Role of Matrix Metalloproteinases-1 and -2 in Interleukin-13–Suppressed Elastin in Airway Fibroblasts in Asthma

PubMed Central

Slade, David; Church, Tony D.; Francisco, Dave; Heck, Karissa; Sigmon, R. Wesley; Ghio, Michael; Murillo, Anays; Firszt, Rafael; Lugogo, Njira L.; Que, Loretta; Sunday, Mary E.; Kraft, Monica

2016-01-01

Elastin synthesis and degradation in the airway and lung parenchyma contribute to airway mechanics, including airway patency and elastic recoil. IL-13 mediates many features of asthma pathobiology, including airway remodeling, but the effects of IL-13 on elastin architecture in the airway wall are not known. We hypothesized that IL-13 modulates elastin expression in airway fibroblasts from subjects with allergic asthma. Twenty-five subjects with mild asthma (FEV1, 89 ± 3% predicted) and 30 normal control subjects (FEV1, 102 ± 2% predicted) underwent bronchoscopy with endobronchial biopsy. Elastic fibers were visualized in airway biopsy specimens using Weigert’s resorcin-fuchsin elastic stain. Airway fibroblasts were exposed to IL-13; a pan-matrix metalloproteinase (MMP) inhibitor (GM6001); specific inhibitors to MMP-1, -2, -3, and -8; and combinations of IL-13 with MMP inhibitors in separate conditions in serum-free media for 48 hours. Elastin (ELN) expression as well as MMP secretion and activity were quantified. Results of this study show that elastic fiber staining of airway biopsy tissue was significantly associated with methacholine PC20 (i.e., the provocative concentration of methacholine resulting in a 20% fall in FEV1 levels) in patients with asthma. IL-13 significantly suppressed ELN expression in asthmatic airway fibroblasts as compared with normal control fibroblasts. The effect of IL-13 on ELN expression was significantly correlated with postbronchodilator FEV1/FVC in patients with asthma. MMP inhibition significantly stimulated ELN expression in patients with asthma as compared with normal control subjects. Specific inhibition of MMP-1 and MMP-2, but not MMP-3 or MMP-8, reversed the IL-13–induced suppression of ELN expression. In asthma, MMP-1 and MMP-2 mediate IL-13–induced suppression of ELN expression in airway fibroblasts. PMID:26074138

Role of Matrix Metalloproteinases-1 and -2 in Interleukin-13-Suppressed Elastin in Airway Fibroblasts in Asthma.

PubMed

Ingram, Jennifer L; Slade, David; Church, Tony D; Francisco, Dave; Heck, Karissa; Sigmon, R Wesley; Ghio, Michael; Murillo, Anays; Firszt, Rafael; Lugogo, Njira L; Que, Loretta; Sunday, Mary E; Kraft, Monica

2016-01-01

Elastin synthesis and degradation in the airway and lung parenchyma contribute to airway mechanics, including airway patency and elastic recoil. IL-13 mediates many features of asthma pathobiology, including airway remodeling, but the effects of IL-13 on elastin architecture in the airway wall are not known. We hypothesized that IL-13 modulates elastin expression in airway fibroblasts from subjects with allergic asthma. Twenty-five subjects with mild asthma (FEV1, 89 ± 3% predicted) and 30 normal control subjects (FEV1, 102 ± 2% predicted) underwent bronchoscopy with endobronchial biopsy. Elastic fibers were visualized in airway biopsy specimens using Weigert's resorcin-fuchsin elastic stain. Airway fibroblasts were exposed to IL-13; a pan-matrix metalloproteinase (MMP) inhibitor (GM6001); specific inhibitors to MMP-1, -2, -3, and -8; and combinations of IL-13 with MMP inhibitors in separate conditions in serum-free media for 48 hours. Elastin (ELN) expression as well as MMP secretion and activity were quantified. Results of this study show that elastic fiber staining of airway biopsy tissue was significantly associated with methacholine PC20 (i.e., the provocative concentration of methacholine resulting in a 20% fall in FEV1 levels) in patients with asthma. IL-13 significantly suppressed ELN expression in asthmatic airway fibroblasts as compared with normal control fibroblasts. The effect of IL-13 on ELN expression was significantly correlated with postbronchodilator FEV1/FVC in patients with asthma. MMP inhibition significantly stimulated ELN expression in patients with asthma as compared with normal control subjects. Specific inhibition of MMP-1 and MMP-2, but not MMP-3 or MMP-8, reversed the IL-13-induced suppression of ELN expression. In asthma, MMP-1 and MMP-2 mediate IL-13-induced suppression of ELN expression in airway fibroblasts.

Chromosomal mapping of quantitative trait loci controlling elastin content in rat aorta.

PubMed

Gauguier, Dominique; Behmoaras, Jacques; Argoud, Karène; Wilder, Steven P; Pradines, Christelle; Bihoreau, Marie Thérèse; Osborne-Pellegrin, Mary; Jacob, Marie Paule

2005-03-01

Extracellular matrix molecules such as elastin and collagens provide mechanical support to the vessel wall. In addition to its structural role, elastin is a regulator that maintains homeostasis through biologic signaling. Genetically determined minor modifications in elastin and collagen in the aorta could influence the onset and evolution of arterial pathology, such as hypertension and its complications. We previously demonstrated that the inbred Brown Norway (BN) rat shows an aortic elastin deficit in both abdominal and thoracic segments, partly because of a decrease in tropoelastin synthesis when compared with the LOU rat, that elastin gene polymorphisms in these strains do not significantly account for. After a genome-wide search for quantitative trait loci (QTL) influencing the aortic elastin, collagen, and cell protein contents in an F2 population derived from BN and LOU rats, we identified on chromosomes 2 and 14, 3 QTL specifically controlling elastin levels, and a further highly significant QTL on chromosome 17 linked to the level of cell proteins. We also mapped 3 highly significant QTL linked to body weight (on chromosomes 1 and 3) and heart weight (on chromosome 1) in the cross. This study demonstrates the polygenic control of the content of key components of the arterial wall. Such information represents a first step in understanding possible mechanisms involved in dysregulation of these parameters in arterial pathology.

Low molecular weight fucoidan attenuates experimental abdominal aortic aneurysm through interfering the leukocyte-endothelial cells interaction.

PubMed

Zhou, Min; Ding, Yong; Cai, Liang; Wang, Yonggang; Lin, Changpo; Shi, Zhenyu

2018-05-01

Low molecular weight fucoidan (LMWF) is a sulfated polysaccharide extracted from Saccharina Japonica that presents high affinity for P-selectin and abolish selectin-dependent recruitment of leukocytes. We hypothesized that dietary intake of LMWF, as a competitive binding agent of P‑selectin, could limit the inflammatory infiltration and aneurysmal growth in an Angiotensin II‑induced abdominal aortic aneurysm (AAA) mouse model. The Gene Expression Omnibus database was used for gene expressions and gene set enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that focal adhesion was involved in the development of AAA. However, dietary intake of LMWF could limit the enlargement of AAA, decreasing maximal aortic diameter and preserving elastin lamellae. Although LMWF did not decrease the circulatory monocytes count and lower the expression of P‑selectin in endothelium, it reduced macrophages infiltration in media and adventitia. Furthermore, matrix metalloproteinase expression was markedly downregulated, accompanied with reduced expression of inflammatory mediators, including interleukin 1β, tumor necrosis factor‑α and monocyte chemotactic protein‑1. The present study revealed a novel target for the treatment of AAA and the anti‑inflammatory effects of LMWF.

Enhanced elastin synthesis and maturation in human vascular smooth muscle tissue derived from induced-pluripotent stem cells.

PubMed

Eoh, Joon H; Shen, Nian; Burke, Jacqueline A; Hinderer, Svenja; Xia, Zhiyong; Schenke-Layland, Katja; Gerecht, Sharon

2017-04-01

Obtaining vascular smooth muscle tissue with mature, functional elastic fibers is a key obstacle in tissue-engineered blood vessels. Poor elastin secretion and organization leads to a loss of specialization in contractile smooth muscle cells, resulting in over proliferation and graft failure. In this study, human induced-pluripotent stem cells (hiPSCs) were differentiated into early smooth muscle cells, seeded onto a hybrid poly(ethylene glycol) dimethacrylate/poly (l-lactide) (PEGdma-PLA) scaffold and cultured in a bioreactor while exposed to pulsatile flow, towards maturation into contractile smooth muscle tissue. We evaluated the effects of pulsatile flow on cellular organization as well as elastin expression and assembly in the engineered tissue compared to a static control through immunohistochemistry, gene expression and functionality assays. We show that culturing under pulsatile flow resulted in organized and functional hiPSC derived smooth muscle tissue. Immunohistochemistry analysis revealed hiPSC-smooth muscle tissue with robust, well-organized cells and elastic fibers and the supporting microfibril proteins necessary for elastic fiber assembly. Through qRT-PCR analysis, we found significantly increased expression of elastin, fibronectin, and collagen I, indicating the synthesis of necessary extracellular matrix components. Functionality assays revealed that hiPSC-smooth muscle tissue cultured in the bioreactor had an increased calcium signaling and contraction in response to a cholinergic agonist, significantly higher mature elastin content and improved mechanical properties in comparison to the static control. The findings presented here detail an effective approach to engineering elastic human vascular smooth muscle tissue with the functionality necessary for tissue engineering and regenerative medicine applications. Obtaining robust, mature elastic fibers is a key obstacle in tissue-engineered blood vessels. Human induced-pluripotent stem cells have become of interest due to their ability to supplement tissue engineered scaffolds. Their ability to differentiate into cells of vascular lineages with defined phenotypes serves as a potential solution to a major cause of graft failure in which phenotypic shifts in smooth muscle cells lead to over proliferation and occlusion of the graft. Herein, we have differentiated human induced-pluripotent stem cells in a pulsatile flow bioreactor, resulting in vascular smooth muscle tissue with robust elastic fibers and enhanced functionality. This study highlights an effective approach to engineering elastic functional vascular smooth muscle tissue for tissue engineering and regenerative medicine applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Mineralocorticoid effects in the late gestation ovine fetal lung

PubMed Central

McCartney, Jarret; Richards, Elaine M.; Wood, Charles E.; Keller‐Wood, Maureen

2014-01-01

Abstract This study was designed to determine the effects of corticosteroids at MR in the late‐gestation fetal lung. Since both the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR) are expressed at relatively high levels in the fetal lung, endogenous corticosteroids may act at MR as well as GR in the preterm fetal lung. The GR agonist, betamethasone, the MR agonist, aldosterone, or both were infused intravenously for 48 h in ovine fetuses of approximately 130 days gestation. Effects on airway pressures during stepwise inflation of the in situ lung, expression of ENaC alpha (SCNN1A), ENaC beta (SCNN1B), and Na,K ATPase (ATP1A1), and elastin and collagen content were determined after the infusions. We found that aldosterone significantly reduced the airway pressure measured during the initial step in inflation of the lung, although aldosterone had no overall effect on lung compliance, nor did aldosterone induce expression of ENaCα, ENaCβ or Na,K ATPaseα1. Betamethasone significantly increased expression of the epithelial sodium channel (ENaC) subunit mRNAs, and collagen and elastin content in the lungs, although this dose of betamethasone also had no effect on lung compliance. There was no synergy between effects of the MR and GR agonists. Transcriptomic analysis suggested that although aldosterone did not alter genes in pathways related to epithelial sodium transport, aldosterone did alter genes in pathways involved in cell proliferation in the lungs. The results are consistent with corticosteroid‐induced fluid reabsorption at birth through GR rather than MR, but suggest that MR facilitates lung maturation, and may contribute to inflation with the first breaths via mechanisms distinct from known aldosterone effects in other epithelia. PMID:25347852

Anti-aging effects of Piper cambodianum P. Fourn. extract on normal human dermal fibroblast cells and a wound-healing model in mice.

PubMed

Lee, Hyunji; Hong, Youngeun; Kwon, So Hee; Park, Jongsun; Park, Jisoo

2016-01-01

Aging of skin is associated with environmental factors such as ultraviolet rays, air pollution, gravity, and genetic factors, all of which can lead to wrinkling of skin. Previous reports suggest that the wound repair is impaired by the aging process and strategies to manipulate the age-related wound healing are necessary in order to stimulate repair. Several traditional plant extracts are well-known for their properties of skin protection and care. Piper cambodianum P. Fourn. (PPF), a member of Piperacecae, is a plant found in Vietnam that might have therapeutic properties. Therefore, the effects of PPF stem and leaf extract on aging process were investigated in vitro and in vivo. PPF extract dissolved in methanol was investigated using Western blotting, real-time quantitative reverse transcription-polymerase chain reaction, flow cytometry, and cell wound-healing assays. We assessed the anti-aging effect of PPF in mouse using the wound-healing assay. The results were analyzed by Student's unpaired t-test; *P<0.05 and **P<0.01 were considered to indicate significant and highly significant values, respectively, compared with corresponding controls. PPF treatment demonstrated in vitro and in vivo anti-aging activity. Western blot analysis of PPF-treated normal human dermal fibroblast cells showed a dose-dependent increase in the expression of extracellular matrix genes such as collagen and elastin, but decreased expression of the aging gene matrix metalloproteinase-3. Quantitative polymerase chain reaction showed that PPF-treated cells displayed dose-dependent increase in messenger RNA expression levels of collagen, elastin, and hyaluronan synthase-2 and decreased expression levels of matrix metalloproteinase-1 aging gene. PPF treatment led to decreased production of reactive oxygen species in cells subjected to ultraviolet irradiation. Furthermore, PPF extract showed positive wound-healing effects in mice. This study demonstrated the anti-aging and wound-healing effects of PPF extract. Therefore, PPF extract represents a promising new therapeutic agent for anti-aging and wound-healing treatments.

Basic components of connective tissues and extracellular matrix: elastin, fibrillin, fibulins, fibrinogen, fibronectin, laminin, tenascins and thrombospondins.

PubMed

Halper, Jaroslava; Kjaer, Michael

2014-01-01

Collagens are the most abundant components of the extracellular matrix and many types of soft tissues. Elastin is another major component of certain soft tissues, such as arterial walls and ligaments. Many other molecules, though lower in quantity, function as essential components of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its muldomain structure plays a role of "master organizer" in matrix assembly as it forms a bridge between cell surface receptors, e.g., integrins, and compounds such collagen, proteoglycans and other focal adhesion molecules. It also plays an essential role in the assembly of fibrillin-1 into a structured network. Laminins contribute to the structure of the extracellular matrix (ECM) and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin by thrombin, it also binds to a variety of compounds, particularly to various growth factors, and as such fibrinogen is a player in cardiovascular and extracellular matrix physiology. Elastin, an insoluble polymer of the monomeric soluble precursor tropoelastin, is the main component of elastic fibers in matrix tissue where it provides elastic recoil and resilience to a variety of connective tissues, e.g., aorta and ligaments. Elastic fibers regulate activity of TGFβs through their association with fibrillin microfibrils. Elastin also plays a role in cell adhesion, cell migration, and has the ability to participate in cell signaling. Mutations in the elastin gene lead to cutis laxa. Fibrillins represent the predominant core of the microfibrils in elastic as well as non-elastic extracellular matrixes, and interact closely with tropoelastin and integrins. Not only do microfibrils provide structural integrity of specific organ systems, but they also provide a scaffold for elastogenesis in elastic tissues. Fibrillin is important for the assembly of elastin into elastic fibers. Mutations in the fibrillin-1 gene are closely associated with Marfan syndrome. Fibulins are tightly connected with basement membranes, elastic fibers and other components of extracellular matrix and participate in formation of elastic fibers. Tenascins are ECM polymorphic glycoproteins found in many connective tissues in the body. Their expression is regulated by mechanical stress both during development and in adulthood. Tenascins mediate both inflammatory and fibrotic processes to enable effective tissue repair and play roles in pathogenesis of Ehlers-Danlos, heart disease, and regeneration and recovery of musculo-tendinous tissue. One of the roles of thrombospondin 1 is activation of TGFβ. Increased expression of thrombospondin and TGFβ activity was observed in fibrotic skin disorders such as keloids and scleroderma. Cartilage oligomeric matrix protein (COMP) or thrombospondin-5 is primarily present in the cartilage. High levels of COMP are present in fibrotic scars and systemic sclerosis of the skin, and in tendon, especially with physical activity, loading and post-injury. It plays a role in vascular wall remodeling and has been found in atherosclerotic plaques as well.

Intracranial arteries in individuals with the elastin gene hemideletion of Williams syndrome.

PubMed

Wint, D P; Butman, J A; Masdeu, J C; Meyer-Lindenberg, A; Mervis, C B; Sarpal, D; Morris, C A; Berman, K F

2014-01-01

Williams syndrome, a rare genetic disorder with a striking neurobehavioral profile characterized by extreme sociability and impaired visuospatial construction abilities, is caused by a hemideletion that includes the elastin gene, resulting in frequent supravavular aortic stenosis and other stenotic arterial lesions. Strokes have been reported in Williams syndrome. Although the extracranial carotid artery has been studied in a sample of patients with Williams syndrome, proximal intracranial arteries have not. Using MRA, we studied the intracranial vessels in 27 participants: 14 patients with Williams syndrome (age range, 18-44 years; mean age, 27.3 ± 9.1; 43% women) and 13 healthy control participants with similar age and sex distribution (age range, 22-52 years; mean age, 33.4 ± 7.6; 46% women). All participants with Williams syndrome had hemideletions of the elastin gene. Blinded to group allocation or to any other clinical data, a neuroradiologist determined the presence of intracranial vascular changes in the 2 groups. The Williams syndrome group and the healthy control group had similar patency of the proximal intracranial arteries, including the internal carotid and vertebral arteries; basilar artery; and stem and proximal branches of the anterior cerebral artery, MCA, and posterior cerebral arteries. The postcommunicating segment of the anterior cerebral artery was longer in the Williams syndrome group. Despite the elastin haploinsufficiency, the proximal intracranial arteries in Williams syndrome preserve normal patency.

Elastin receptor (S-gal) occupancy by elastin peptides modulates T-cell response during murine emphysema.

PubMed

Meghraoui-Kheddar, Aïda; Pierre, Alexandre; Sellami, Mehdi; Audonnet, Sandra; Lemaire, Flora; Le Naour, Richard

2017-09-01

Chronic obstructive pulmonary disease and emphysema are associated with increased elastin peptides (EP) production because of excessive breakdown of lung connective tissue. We recently reported that exposure of mice to EP elicited hallmark features of emphysema. EP effects are largely mediated through a receptor complex that includes the elastin-binding protein spliced-galactosidase (S-gal). In previous studies, we established a correlation between cytokine production and S-gal protein expression in EP-treated immune cells. In this study, we investigated the S-gal-dependent EP effects on T-helper (Th) and T-cytotoxic (Tc) responses during murine EP-triggered pulmonary inflammation. C57BL/6J mice were endotracheally instilled with the valine-glycine-valine-alanine-proline-glycine (VGVAPG) elastin peptide, and, 21 days after treatment, local and systemic T-lymphocyte phenotypes were analyzed at cytokine and transcription factor expression levels by multicolor flow cytometry. Exposure of mice to the VGVAPG peptide resulted in a significant increase in the proportion of the CD4 + and CD8 + T cells expressing the cytokines IFN-γ or IL-17a and the transcription factors T-box expressed in T cells or retinoic acid-related orphan receptor-γt (RORγt) without effects on IL-4 and Gata-binding protein 3 to DNA sequence [A/T]GATA[A/G] expression. These effects were maximized when each T-cell subpopulation was challenged ex vivo with EP, and they were inhibited in vivo when an analogous peptide antagonizing the EP/S-gal interactions was instilled together with the VGVAPG peptide. This study demonstrates that, during murine emphysema, EP-S-gal interactions contribute to a Th-1 and Th-17 proinflammatory T-cell response combined with a Tc-1 response. Our study also highlights the S-gal receptor as a putative pharmacological target to modulate such an immune response. Copyright © 2017 the American Physiological Society.

Chronic Treatment with Minoxidil Induces Elastic Fiber Neosynthesis and Functional Improvement in the Aorta of Aged Mice.

PubMed

Coquand-Gandit, Marion; Jacob, Marie-Paule; Fhayli, Wassim; Romero, Beatriz; Georgieva, Miglena; Bouillot, Stéphanie; Estève, Eric; Andrieu, Jean-Pierre; Brasseur, Sandrine; Bouyon, Sophie; Garcia-Honduvilla, Natalio; Huber, Philippe; Buján, Julia; Atanasova, Milena; Faury, Gilles

2017-06-01

Normal arterial aging processes involve vascular cell dysfunction associated with wall stiffening, the latter being due to progressive elastin and elastic fiber degradation, and elastin and collagen cross-linking by advanced glycation end products (AGEs). These processes progressively lead to cardiovascular dysfunction during aging. Elastin is only synthesized during late gestation and childhood, and further degradation occurring throughout adulthood cannot be physiologically compensated by replacement of altered material. However, the ATP-dependent K + channel opener minoxidil has been shown to stimulate elastin expression in vitro and in vivo in the aorta of young adult rats. Therefore, we have studied the effect of a 10-week chronic oral treatment with minoxidil (120 mg/L in drinking water) on the aortic structure and function in aged 24-month-old mice. Minoxidil treatment increased tropoelastin, fibulin-5, and lysyl-oxidase messenger RNA levels, reinduced a moderate expression of elastin, and lowered the levels of AGE-related molecules. This was accompanied by the formation of newly synthesized elastic fibers, which had diverse orientations in the wall. A decrease in the glycation capacity of aortic elastin was also produced by minoxidil treatment. The ascending aorta also underwent a minoxidil-induced increase in diameter and decrease in wall thickness, which partly reversed the age-associated thickening and returned the wall thickness value and strain-stress relation closer to those of younger adult animals. In conclusion, our results suggest that minoxidil presents an interesting potential for arterial remodeling in an antiaging perspective, even when treating already aged animals.

Highly variable cutis laxa resulting from a dominant splicing mutation of the elastin gene.

PubMed

Graul-Neumann, Luitgard M; Hausser, Ingrid; Essayie, Maximilian; Rauch, Anita; Kraus, Cornelia

2008-04-15

Autosomal dominant congenital cutis laxa (ADCL) is genetically heterogeneous and shows clinical variability. Only seven ADCL families with mutations in the elastin gene (ELN) have been described previously. We present morphological and molecular genetic studies in a cutis laxa kindred with a previously undescribed highly variable phenotype caused by a novel ELN mutation c.1621 C > T. The proband presented with severe cutis laxa, severe congenital lung disease previously undescribed in ADCL and pulmonary artery disease, which is often seen in ARCL but rare in ADCL. He also developed infantile spasms (OMIM 308350; West syndrome), which we consider a coincidental association although recessive cutis laxa or even digenic inheritance cannot be excluded. Electron microscopy of the proband's dermis revealed only mild rarefication of elastic fibers (in contrast to most recessive cutis laxa types). Apart from mild elastic fiber fragmentation, dermal morphology of the proband's father was within normal range. Molecular analysis of the ELN gene using genomic DNA from blood and RNA from cultured skin fibroblasts indicated a novel splice site mutation in the proband and his clinically healthy father. Analysis of ELN expression in fibroblasts provided evidence for a dominant-negative effect in the child, while due to an unknown mechanism, the father showed haploinsufficiency which might explain the significant clinical variability. Copyright 2008 Wiley-Liss, Inc.

A cytokine axis regulates elastin formation and degradation

PubMed Central

Sproul, Erin P.; Argraves, W. Scott

2013-01-01

Underlying the dynamic regulation of tropoelastin expression and elastin formation in development and disease are transcriptional and post-transcriptional mechanisms that have been the focus of much research. Of particular importance is the cytokine–governed elastin regulatory axis in which the pro-elastogenic activities of transforming growth factor β-1 (TGFβ1) and insulin-like growth factor-I (IGF-I) are opposed by anti-elastogenic activities of basic fibroblast growth factor (bFGF/FGF-2), heparin-binding epidermal growth factor-like growth factor (HB-EGF), EGF, PDGF-BB, TGFα, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and noncanonical TGFβ1 signaling. A key mechanistic feature of the regulatory axis is that cytokines influence elastin formation through effects on the cell cycle involving control of cyclin–cyclin dependent kinase complexes and activation of the Ras/MEK/ERK signaling pathway. In this article we provide an overview of the major cytokines/growth factors that modulate elastogenesis and describe the underlying molecular mechanisms for their action on elastin production. PMID:23160093

Deficient Circumferential Growth Is the Primary Determinant of Aortic Obstruction Attributable to Partial Elastin Deficiency.

PubMed

Jiao, Yang; Li, Guangxin; Korneva, Arina; Caulk, Alexander W; Qin, Lingfeng; Bersi, Matthew R; Li, Qingle; Li, Wei; Mecham, Robert P; Humphrey, Jay D; Tellides, George

2017-05-01

Williams syndrome is characterized by obstructive aortopathy attributable to heterozygous loss of ELN , the gene encoding elastin. Lesions are thought to result primarily from excessive smooth muscle cell (SMC) proliferation and consequent medial expansion, although an initially smaller caliber and increased stiffness of the aorta may contribute to luminal narrowing. The relative contributions of such abnormalities to the obstructive phenotype had not been defined. We quantified determinants of luminal stenosis in thoracic aortas of Eln -/- mice incompletely rescued by human ELN . Moderate obstruction was largely because of deficient circumferential growth, most prominently of ascending segments, despite increased axial growth. Medial thickening was evident in these smaller diameter elastin-deficient aortas, with medial area similar to that of larger diameter control aortas. There was no difference in cross-sectional SMC number between mutant and wild-type genotypes at multiple stages of postnatal development. Decreased elastin content was associated with medial fibrosis and reduced aortic distensibility because of increased structural stiffness but preserved material stiffness. Elastin-deficient SMCs exhibited greater contractile-to-proliferative phenotypic modulation in vitro than in vivo. We confirmed increased medial collagen without evidence of increased medial area or SMC number in a small ascending aorta with thickened media of a Williams syndrome subject. Deficient circumferential growth is the predominant mechanism for moderate obstructive aortic disease resulting from partial elastin deficiency. Our findings suggest that diverse aortic manifestations in Williams syndrome result from graded elastin content, and SMC hyperplasia causing medial expansion requires additional elastin loss superimposed on ELN haploinsufficiency. © 2017 American Heart Association, Inc.

Elastin Is Differentially Regulated by Pressure Therapy in a Porcine Model of Hypertrophic Scar.

PubMed

Carney, Bonnie C; Liu, Zekun; Alkhalil, Abdulnaser; Travis, Taryn E; Ramella-Roman, Jessica; Moffatt, Lauren T; Shupp, Jeffrey W

Beneficial effects of pressure therapy for hypertrophic scars have been reported, but the mechanisms of action are not fully understood. This study evaluated elastin and its contribution to scar pliability. The relationship between changes in Vancouver Scar Scale (VSS) scores of pressure-treated scars and differential regulation of elastin was assessed. Hypertrophic scars were created and assessed weekly using VSS and biopsy procurement. Pressure treatment began on day 70 postinjury. Treated scars were compared with untreated shams. Treatment lasted 2 weeks, through day 84, and scars were assessed weekly through day 126. Transcript and protein levels of elastin were quantified. Pressure treatment resulted in lower VSS scores compared with sham-treated scars. Pliability (VSSP) was a key contributor to this difference. At day 70 pretreatment, VSSP = 2. Without treatment, sham-treated scars became less pliable, while pressure-treated scars became more pliable. The percentage of elastin in scars at day 70 was higher than in uninjured skin. Following treatment, the percentage of elastin increased and continued to increase through day 126. Untreated sham scars did not show a similar increase. Quantification of Verhoeff-Van Gieson staining corroborated the findings and immunofluorescence revealed the alignment of elastin fibers. Pressure treatment results in increased protein level expression of elastin compared with sham-untreated scars. These findings further characterize the extracellular matrix's response to the application of pressure as a scar treatment, which will contribute to the refinement of rehabilitation practices and ultimately improvements in functional and psychosocial outcomes for patients.

PKCε Increases Extracellular Elastin and Fibulin-5/DANCE in Dermal Fibroblasts.

PubMed

Nishizaki, Tomoyuki

2018-01-01

In the earlier study, the selective PKCε activator DCP-LA increased elastic fibres in the dermis of HR-1 hairless mice. As a process of elastic fibre formation, tropoelastin, an elastin monomer, is secreted into the extracellular space. Secreted tropoelastin is delivered to the microfibrils by fibulin-5/developmental arteries and neural crest epidermal growth factor-like (DANCE) and undergoes self-association. Then, tropoelastin assembles around the microfibrils, growing into elastin and elastic fibres by lysyl oxidase (LOX)- or LOX-like (LOXL)-mediated cross-linking. The present study was conducted to understand the mechanism underlying DCP-LA-induced increase in elastin/elastic fibre. Western blotting, immunocytochemistory, and real-time reverse transcription-polymerase chain reaction (RT-PCR) were carried out in cultured human dermal fibroblasts. PKCε, mammalian target of rapamycin complex (mTOR), and p70 S6 kinase (S6K) were knocked-down by transfecting each siRNA. DCP-LA increased elastin and fibulin-5/DANCE in a treatment time (6-24 h)- and a bell-shaped concentration (1 nM-1 µM)-dependent manner in the culture medium of human dermal fibroblasts. DCP-LA markedly increased elastic fibres in the extracellular space of cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was abolished by a PKC inhibitor or knocking-down PKCε. DCP-LA did not affect expression of mRNAs for tropoelastin and fiblin-5/DANCE in cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was not inhibited by the protein synthesis inhibitor cycloheximide or by knocking-down mTOR and S6K. DCP-LA never increased extracellular elastin in the presence of elastase, that breaks down elastin. An inhibitor of matrix metalloproteinase 9, that degrades multiple extracellular matrix components including elastin, had no effect on the basal levels and the DCP-LA-induced increase levels of extracellular elastin. The results of the present study indicate that PKCε, activated by DCP-LA, increases elastin and fibulin-5/DANCE in the extracellular space of cultured fibroblasts by the mechanism independent of transcriptional and translational modulation or inhibition of elastolysis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Insoluble elastin reduces collagen scaffold stiffness, improves viscoelastic properties, and induces a contractile phenotype in smooth muscle cells.

PubMed

Ryan, Alan J; O'Brien, Fergal J

2015-12-01

Biomaterials with the capacity to innately guide cell behaviour while also displaying suitable mechanical properties remain a challenge in tissue engineering. Our approach to this has been to utilise insoluble elastin in combination with collagen as the basis of a biomimetic scaffold for cardiovascular tissue engineering. Elastin was found to markedly alter the mechanical and biological response of these collagen-based scaffolds. Specifically, during extensive mechanical assessment elastin was found to reduce the specific tensile and compressive moduli of the scaffolds in a concentration dependant manner while having minimal effect on scaffold microarchitecture with both scaffold porosity and pore size still within the ideal ranges for tissue engineering applications. However, the viscoelastic properties were significantly improved with elastin addition with a 3.5-fold decrease in induced creep strain, a 6-fold increase in cyclical strain recovery, and with a four-parameter viscoelastic model confirming the ability of elastin to confer resistance to long term deformation/creep. Furthermore, elastin was found to result in the modulation of SMC phenotype towards a contractile state which was determined via reduced proliferation and significantly enhanced expression of early (α-SMA), mid (calponin), and late stage (SM-MHC) contractile proteins. This allows the ability to utilise extracellular matrix proteins alone to modulate SMC phenotype without any exogenous factors added. Taken together, the ability of elastin to alter the mechanical and biological response of collagen scaffolds has led to the development of a biomimetic biomaterial highly suitable for cardiovascular tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cues for cellular assembly of vascular elastin networks

NASA Astrophysics Data System (ADS)

Kothapalli, Chandrasekhar R.

Elastin, a structural protein distributed in the extracellular matrix of vascular tissues is critical to the maintenance of vascular mechanics, besides regulation of cell-signaling pathways involved in injury response and morphogenesis. Thus, congenital absence or disease-mediated degradation of vascular elastin and its malformation within native vessels due to innately poor elastin synthesis by adult vascular cells compromise vascular homeostasis. Current elastin regenerative strategies using tissue engineering principles are limited by the progressive destabilization of tropoelastin mRNA expression in adult vascular cells and the unavailability of scaffolds that can provide cellular cues necessary to up-regulate elastin synthesis and regenerate faithful mimics of native elastin. Since our earlier studies demonstrated the elastogenic utility of hyaluronan (HA)-based cues, we have currently sought to identify a unique set of culture conditions based on HA fragments (0.756-2000 kDa), growth factors (TGF-beta1, IGF-1) and other biomolecules (Cu2+ ions, LOX), which will together enhance synthesis, crosslinking, maturation and fibrous elastin matrix formation by adult SMCs, under both healthy and inflammatory conditions. It was observed that TGF-beta1 (1 ng/mL) together with HA oligomers (0.2 microg/mL) synergistically suppressed SMC proliferation, enhanced tropoelastin (8-fold) and matrix elastin synthesis (5.5-fold), besides improving matrix yield (4.5-fold), possibly by increasing production and activity of lysyl oxidase (LOX). Though addition of IGF-1 alone did not offer any advantage, HA fragments (20-200 kDa) in the presence of IGF-1 stimulated tropoelastin and soluble elastin synthesis more than 2.2-fold, with HMW HA contributing for ˜5-fold increase in crosslinked matrix elastin synthesis. Similarly, 0.1 M of Cu2+ ions, alone or together with HA fragments stimulated synthesis of tropoelastin (4-fold) and crosslinked matrix elastin (4.5-fold), via increases in LOX protein synthesis (2.5-fold); these cues also enhanced deposition of mature elastic fibers (˜1 mum diameter) within these cultures. Interestingly, instead of copper salt addition, even release of Cu 2+ ions (˜0.1 M) from copper nanoparticles (400 ng/mL), concurrent with HA oligomers, promoted crosslinking of elastin into mature matrix, with multiple bundles of highly-crosslinked elastin fiber formation observed (diameter ˜200-500 nm). These results strongly attest to the potential individual and combined benefits of these cues to faithful elastin matrix regeneration by healthy, patient-derived cells within tissue-engineered vascular constructs. When these cues (TGF-beta1 and HA oligomers) were added to TNF-alpha-stimulated SMC cultures, model cell culture systems mimicking phenotypically-altered cells within aneurysms, they upregulated elastin matrix production, organized elastin protein into fibers, and simultaneously stabilized this matrix by attenuating production of elastolytic enzymes. Similarly these cues also attenuated inflammatory cytokines release within cells isolated from induced-aortic aneurysms in rats, and significantly upregulated elastin synthesis and matrix formation by upregulating LOX and desmosine protein amounts. The cues were also highly effective in organizing the elastin into fibrous matrix structures mimicking the native elastin deposition process. The outcomes of this study might be of tremendous use in optimizing design of HA constructs to modulate vascular healing and matrix synthesis following revascularization, and in enabling repair of elastin networks within diseased or inflammatory (aneurysmal) adult vascular tissues.

Anti-aging effects of Piper cambodianum P. Fourn. extract on normal human dermal fibroblast cells and a wound-healing model in mice

PubMed Central

Lee, Hyunji; Hong, Youngeun; Kwon, So Hee; Park, Jongsun; Park, Jisoo

2016-01-01

Background Aging of skin is associated with environmental factors such as ultraviolet rays, air pollution, gravity, and genetic factors, all of which can lead to wrinkling of skin. Previous reports suggest that the wound repair is impaired by the aging process and strategies to manipulate the age-related wound healing are necessary in order to stimulate repair. Objective Several traditional plant extracts are well-known for their properties of skin protection and care. Piper cambodianum P. Fourn. (PPF), a member of Piperacecae, is a plant found in Vietnam that might have therapeutic properties. Therefore, the effects of PPF stem and leaf extract on aging process were investigated in vitro and in vivo. Methods PPF extract dissolved in methanol was investigated using Western blotting, real-time quantitative reverse transcription-polymerase chain reaction, flow cytometry, and cell wound-healing assays. We assessed the anti-aging effect of PPF in mouse using the wound-healing assay. The results were analyzed by Student’s unpaired t-test; *P<0.05 and **P<0.01 were considered to indicate significant and highly significant values, respectively, compared with corresponding controls. Results PPF treatment demonstrated in vitro and in vivo anti-aging activity. Western blot analysis of PPF-treated normal human dermal fibroblast cells showed a dose-dependent increase in the expression of extracellular matrix genes such as collagen and elastin, but decreased expression of the aging gene matrix metalloproteinase-3. Quantitative polymerase chain reaction showed that PPF-treated cells displayed dose-dependent increase in messenger RNA expression levels of collagen, elastin, and hyaluronan synthase-2 and decreased expression levels of matrix metalloproteinase-1 aging gene. PPF treatment led to decreased production of reactive oxygen species in cells subjected to ultraviolet irradiation. Furthermore, PPF extract showed positive wound-healing effects in mice. Conclusion This study demonstrated the anti-aging and wound-healing effects of PPF extract. Therefore, PPF extract represents a promising new therapeutic agent for anti-aging and wound-healing treatments. PMID:27536082

Mitochondria-targeted antioxidant therapy with MitoQ ameliorates aortic stiffening in old mice.

PubMed

Gioscia-Ryan, Rachel A; Battson, Micah L; Cuevas, Lauren M; Eng, Jason S; Murphy, Michael P; Seals, Douglas R

2018-05-01

Aortic stiffening is a major independent risk factor for cardiovascular diseases, cognitive dysfunction, and other chronic disorders of aging. Mitochondria-derived reactive oxygen species are a key source of arterial oxidative stress, which may contribute to arterial stiffening by promoting adverse structural changes-including collagen overabundance and elastin degradation-and enhancing inflammation, but the potential for mitochondria-targeted therapeutic strategies to ameliorate aortic stiffening with primary aging is unknown. We assessed aortic stiffness [pulse-wave velocity (aPWV)], ex vivo aortic intrinsic mechanical properties [elastic modulus (EM) of collagen and elastin regions], and aortic protein expression in young (~6 mo) and old (~27 mo) male C57BL/6 mice consuming normal drinking water (YC and OC) or water containing mitochondria-targeted antioxidant MitoQ (250 µM; YMQ and OMQ) for 4 wk. Both baseline and postintervention aPWV values were higher in OC vs. YC (post: 482 ± 21 vs. 420 ± 5 cm/s, P < 0.05). MitoQ had no effect in young mice but decreased aPWV in old mice (OMQ, 426 ± 20, P < 0.05 vs. OC). MitoQ did not affect age-associated increases in aortic collagen-region EM, collagen expression, or proinflammatory cytokine expression, but partially attenuated age-associated decreases in elastin region EM and elastin expression. Our results demonstrate that MitoQ reverses in vivo aortic stiffness in old mice and suggest that mitochondria-targeted antioxidants may represent a novel, promising therapeutic strategy for decreasing aortic stiffness with primary aging and, possibly, age-related clinical disorders in humans. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation/reversal of age-related aortic elastin degradation. NEW & NOTEWORTHY We show that 4 wk of treatment with the mitochondria-specific antioxidant MitoQ in mice completely reverses the age-associated elevation in aortic stiffness, assessed as aortic pulse-wave velocity. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation of age-related aortic elastin degradation. Our results suggest that mitochondria-targeted therapeutic strategies may hold promise for decreasing arterial stiffening with aging in humans, possibly decreasing the risk of many chronic age-related clinical disorders.

Mitochondria-targeted antioxidant therapy with MitoQ ameliorates aortic stiffening in old mice

PubMed Central

Gioscia-Ryan, Rachel A.; Battson, Micah L.; Cuevas, Lauren M.; Eng, Jason S.; Murphy, Michael P.

2018-01-01

Aortic stiffening is a major independent risk factor for cardiovascular diseases, cognitive dysfunction, and other chronic disorders of aging. Mitochondria-derived reactive oxygen species are a key source of arterial oxidative stress, which may contribute to arterial stiffening by promoting adverse structural changes—including collagen overabundance and elastin degradation—and enhancing inflammation, but the potential for mitochondria-targeted therapeutic strategies to ameliorate aortic stiffening with primary aging is unknown. We assessed aortic stiffness [pulse-wave velocity (aPWV)], ex vivo aortic intrinsic mechanical properties [elastic modulus (EM) of collagen and elastin regions], and aortic protein expression in young (~6 mo) and old (~27 mo) male C57BL/6 mice consuming normal drinking water (YC and OC) or water containing mitochondria-targeted antioxidant MitoQ (250 µM; YMQ and OMQ) for 4 wk. Both baseline and postintervention aPWV values were higher in OC vs. YC (post: 482 ± 21 vs. 420 ± 5 cm/s, P < 0.05). MitoQ had no effect in young mice but decreased aPWV in old mice (OMQ, 426 ± 20, P < 0.05 vs. OC). MitoQ did not affect age-associated increases in aortic collagen-region EM, collagen expression, or proinflammatory cytokine expression, but partially attenuated age-associated decreases in elastin region EM and elastin expression. Our results demonstrate that MitoQ reverses in vivo aortic stiffness in old mice and suggest that mitochondria-targeted antioxidants may represent a novel, promising therapeutic strategy for decreasing aortic stiffness with primary aging and, possibly, age-related clinical disorders in humans. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation/reversal of age-related aortic elastin degradation. NEW & NOTEWORTHY We show that 4 wk of treatment with the mitochondria-specific antioxidant MitoQ in mice completely reverses the age-associated elevation in aortic stiffness, assessed as aortic pulse-wave velocity. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation of age-related aortic elastin degradation. Our results suggest that mitochondria-targeted therapeutic strategies may hold promise for decreasing arterial stiffening with aging in humans, possibly decreasing the risk of many chronic age-related clinical disorders. PMID:29074712

Williams-Beuren syndrome: phenotypic variability and deletions of chromosomes 7, 11, and 22 in a series of 52 patients.

PubMed Central

Joyce, C A; Zorich, B; Pike, S J; Barber, J C; Dennis, N R

1996-01-01

Fluorescence in situ hybridisation (FISH) and conventional chromosome analysis were performed on a series of 52 patients with classical Williams-Beuren syndrome (WBS), suspected WBS, or supravalvular aortic stenosis (SVAS). In the classical WBS group, 22/23 (96%) had a submicroscopic deletion of the elastin locus on chromosome 7, but the remaining patient had a unique interstitial deletion of chromosome 11 (del(11)(q13.5q14.2)). In the suspected WBS group 2/22 (9%) patients had elastin deletions but a third patient had a complex karyotype including a ring chromosome 22 with a deletion of the long arm (r(22)(p11-->q13)). In the SVAS group, 1/7 (14%) had an elastin gene deletion, despite having normal development and minimal signs of WBS. Overall, some patients with submicroscopic elastin deletions have fewer features of Williams-Beuren syndrome than those with other cytogenetic abnormalities. These results, therefore, emphasise the importance of a combined conventional and molecular cytogenetic approach to diagnosis and suggest that the degree to which submicroscopic deletions of chromosome 7 extend beyond the elastin locus may explain some of the phenotypic variability found in Williams-Beuren syndrome. Images PMID:9004128

In vivo assessment of aortic aneurysm wall integrity using elastin-specific molecular magnetic resonance imaging.

PubMed

Botnar, René M; Wiethoff, Andrea J; Ebersberger, Ullrich; Lacerda, Sara; Blume, Ulrike; Warley, Alice; Jansen, Christian H P; Onthank, David C; Cesati, Richard R; Razavi, Reza; Marber, Michael S; Hamm, Bernd; Schaeffter, Tobias; Robinson, Simon P; Makowski, Marcus R

2014-07-01

The incidence of abdominal aortic aneurysms (AAAs) has increased during the last decades. However, there is still controversy about the management of medium-sized AAAs. Therefore, novel biomarkers, besides aneurysmal diameter, are needed to assess aortic wall integrity and risk of rupture. Elastin is the key protein for maintaining aortic wall tensile strength and stability. The progressive breakdown of structural proteins, in particular, medial elastin, is responsible for the inability of the aortic wall to withstand intraluminal hemodynamic forces. Here, we evaluate the usefulness of elastin-specific molecular MRI for the in vivo characterization of AAAs. To induce AAAs, ApoE(-/-) mice were infused with angiotensin-II. An elastin-specific magnetic resonance molecular imaging agent (ESMA) was administered after 1, 2, 3, and 4 weeks of angiotensin-II infusion to assess elastin composition of the aorta (n=8 per group). The high signal provided by ESMA allowed for imaging with high spatial resolution, resulting in an accurate assessment of ruptured elastic laminae and the compensatory expression of elastic fibers. In vivo contrast-to-noise ratios and R1-relaxation rates after ESMA administration were in good agreement with ex vivo histomorphometry (Elastica van Gieson stain) and gadolinium concentrations determined by inductively coupled plasma mass spectroscopy. Electron microscopy confirmed colocalization of ESMA with elastic fibers. Changes in elastin content could be readily delineated and quantified at different stages of AAAs by elastin-specific molecular magnetic resonance imaging. ESMA-MRI offers potential for the noninvasive detection of the aortic rupture site prior to dilation of the aorta and the subsequent in vivo monitoring of compensatory repair processes during the progression of AAAs. © 2014 American Heart Association, Inc.

Nitric oxide donor restores lung growth factor and receptor expression in hyperoxia-exposed rat pups.

PubMed

Lopez, Emmanuel; Boucherat, Olivier; Franco-Montoya, Marie-Laure; Bourbon, Jacques R; Delacourt, Christophe; Jarreau, Pierre-Henri

2006-06-01

Exposure of newborn rats to hyperoxia impairs alveolarization. Nitric oxide (NO) may prevent this evolution. Angiogenesis and factors involved in this process, but also other growth factors (GFs) involved in alveolar development, are likely potential therapeutic targets for NO. We studied the effects of the NO donor, [Z]-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)aminio]diazen-1-ium-1, 2-diolate, also termed DETANONOate (D-NO), on hyperoxia-induced changes in key regulatory factors of alveolar development in neonatal rats, and its possible preventive effect on the physiologic consequences of hyperoxia. Newborn rat pups were randomized at birth to hyperoxia (> 95% O2) or room air exposure for 6 or 10 d, while receiving D-NO or its diluent. On Day 6, several GFs and their receptors were studied at pre- and/or post-translational levels. Elastin transcript determination on Day 6, and elastin deposition in tissue and morphometric analysis of the lungs on Day 10, were also performed. Hyperoxia decreased the expression of vascular endothelial growth factor (VEGF) receptor (VEGFR) 2, fibroblast growth factor (FGF)-18, and FGF receptors (FGFRs) FGFR3 and FGFR4, increased mortality, and impaired alveolarization and capillary growth. D-NO treatment of hyperoxia-exposed pups restored the expression level of FGF18 and FGFR4, induced an increase of both VEGF mRNA and protein, enhanced elastin expression, and partially restored elastin deposition in alveolar walls. Although, under the present conditions, D-NO failed to prevent the physiologic consequences of hyperoxia in terms of survival and lung alveolarization, our findings demonstrate molecular effects of NO on GFs involved in alveolar development that may have contributed to the protective effects previously reported for NO.

Aortic microcalcification is associated with elastin fragmentation in Marfan syndrome.

PubMed

Wanga, Shaynah; Hibender, Stijntje; Ridwan, Yanto; van Roomen, Cindy; Vos, Mariska; van der Made, Ingeborg; van Vliet, Nicole; Franken, Romy; van Riel, Luigi Amjg; Groenink, Maarten; Zwinderman, Aeilko H; Mulder, Barbara Jm; de Vries, Carlie Jm; Essers, Jeroen; de Waard, Vivian

2017-11-01

Marfan syndrome (MFS) is a connective tissue disorder in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery (<5 cm) may unexpectedly experience an aortic dissection or rupture, despite yearly monitoring. Hence, there is a clear need for improved prognostic markers to predict such aortic events. We hypothesize that elastin fragments play a causal role in aortic calcification in MFS, and that microcalcification serves as a marker for aortic disease severity. To address this hypothesis, we analysed MFS patient and mouse aortas. MFS patient aortic tissue showed enhanced microcalcification in areas with extensive elastic lamina fragmentation in the media. A causal relationship between medial injury and microcalcification was revealed by studies in vascular smooth muscle cells (SMCs); elastin peptides were shown to increase the activity of the calcification marker alkaline phosphatase (ALP) and reduce the expression of the calcification inhibitor matrix GLA protein in human SMCs. In murine Fbn1 C1039G/+ MFS aortic SMCs, Alpl mRNA and activity were upregulated as compared with wild-type SMCs. The elastin peptide-induced ALP activity was prevented by incubation with lactose or a neuraminidase inhibitor, which inhibit the elastin receptor complex, and a mitogen-activated protein kinase kinase-1/2 inhibitor, indicating downstream involvement of extracellular signal-regulated kinase-1/2 (ERK1/2) phosphorylation. Histological analyses in MFS mice revealed macrocalcification in the aortic root, whereas the ascending aorta contained microcalcification, as identified with the near-infrared fluorescent bisphosphonate probe OsteoSense-800. Significantly, microcalcification correlated strongly with aortic diameter, distensibility, elastin breaks, and phosphorylated ERK1/2. In conclusion, microcalcification co-localizes with aortic elastin degradation in MFS aortas of humans and mice, where elastin-derived peptides induce a calcification process in SMCs via the elastin receptor complex and ERK1/2 activation. We propose microcalcification as a novel imaging marker to monitor local elastin degradation and thus predict aortic events in MFS patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Oxygenation decreases elastin secretion from rat ductus arteriosus smooth muscle cells.

PubMed

Kawakami, Shoji; Minamisawa, Susumu

2015-08-01

The ductus arteriosus (DA), a fetal arterial connection between the main pulmonary artery and the descending aorta, normally closes immediately after birth. The oxygen concentration in the blood rises after birth, and in the DA this increase in oxygen concentration causes functional closure, which is induced by smooth muscle contraction. Previous studies have demonstrated that hypoxia and/or oxygenation affect vascular remodeling of various vessels. Therefore, we hypothesized that the rise in oxygen concentration would affect the vascular structure of the DA due to production of proteins secreted from DA smooth muscle cells (SMC). Liquid chromatography-tandem mass spectrometry was used to comprehensively investigate the secreted proteins in the supernatant of rat DA SMC harvested under hypoxic conditions (1% oxygen) or under normoxic conditions (21% oxygen). We found that the rise in oxygen concentration reduced the secretion of elastin from DA SMC. On reverse transcription-polymerase chain reaction, the expression of elastin mRNA was not significantly changed in DA SMC from hypoxic to normoxic conditions. Given that elastin forms internal elastic lamina and elastic fibers in the vascular muscle layers, and that a rise in oxygen concentration reduced the secretion of elastin, this suggests that the rise in blood oxygen concentration after birth reduces the secretion of elastin, and therefore may play a role in DA structural remodeling after birth. © 2015 Japan Pediatric Society.

Crosslinked elastic fibers are necessary for low energy loss in the ascending aorta.

PubMed

Kim, Jungsil; Staiculescu, Marius Catalin; Cocciolone, Austin J; Yanagisawa, Hiromi; Mecham, Robert P; Wagenseil, Jessica E

2017-08-16

In the large arteries, it is believed that elastin provides the resistance to stretch at low pressure, while collagen provides the resistance to stretch at high pressure. It is also thought that elastin is responsible for the low energy loss observed with cyclic loading. These tenets are supported through experiments that alter component amounts through protease digestion, vessel remodeling, normal growth, or in different artery types. Genetic engineering provides the opportunity to revisit these tenets through the loss of expression of specific wall components. We used newborn mice lacking elastin (Eln -/- ) or two key proteins (lysyl oxidase, Lox -/- , or fibulin-4, Fbln4 -/- ) that are necessary for the assembly of mechanically-functional elastic fibers to investigate the contributions of elastic fibers to large artery mechanics. We determined component content and organization and quantified the nonlinear and viscoelastic mechanical behavior of Eln -/- , Lox -/- , and Fbln4 -/- ascending aorta and their respective controls. We confirmed that the lack of elastin, fibulin-4, or lysyl oxidase leads to absent or highly fragmented elastic fibers in the aortic wall and a 56-97% decrease in crosslinked elastin amounts. We found that the resistance to stretch at low pressure is decreased only in Eln -/- aorta, confirming the role of elastin in the nonlinear mechanical behavior of the aortic wall. Dissipated energy with cyclic loading and unloading is increased 53-387% in Eln -/- , Lox -/- , and Fbln4 -/- aorta, indicating that not only elastin, but properly assembled and crosslinked elastic fibers, are necessary for low energy loss in the aorta. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deposition of insoluble elastin by pulmonary fibroblasts from patients with COPD is increased by treatment with versican siRNA.

PubMed

Wu, Lian; Zhang, Jing; Qu, Jie Ming; Bai, Chun-Xue; Merrilees, Mervyn J

2017-01-01

A reduced content of alveolar elastic fibers is a key feature of COPD lung. Despite continued elastogenic potential by alveolar fibroblasts in the lung affected by COPD, repair of elastic fibers does not take place, which is due to increased levels of the chondroitin sulfate proteoglycan versican that inhibits the assembly of tropoelastin into fibers. In this study, primary pulmonary fibroblast cell lines from COPD and non-COPD patients were treated with a small interfering RNA (siRNA) against versican to determine if knockdown of versican could restore the deposition of insoluble elastin. Versican siRNA treatment reduced versican expression and secretion by pulmonary fibroblasts from both COPD and non-COPD patients ( P <0.01) and significantly increased deposition of insoluble elastin in the COPD cell cultures ( P <0.05). The treatment, however, did not significantly affect production of soluble elastin (tropoelastin) in either the COPD or non-COPD cell cultures, supporting a role for versican in inhibiting assembly but not synthesis of tropoelastin. These results suggest that removal or knockdown of versican may be a possible therapeutic strategy for increasing deposition of insoluble elastin and stimulating repair of elastic fibers in COPD lung.

Hydroxyapatite and Calcified Elastin Induce Osteoblast-like Differentiation in Rat Aortic Smooth Muscle Cells

PubMed Central

Lei, Yang; Sinha, Aditi; Nosoudi, Nasim; Grover, Ankit; Vyavahare, Naren

2014-01-01

Vascular calcification can be categorized into two different types. Intimal calcification related to atherosclerosis and elastin-specific medial arterial calcification (MAC). Osteoblast-like differentiation of vascular smooth muscle cells (VSMCs) has been shown in both types; however, how this relates to initiation of vascular calcification is unclear. We hypothesize that the initial deposition of hydroxyapatite-like mineral in MAC occurs on degraded elastin first and that causes osteogenic transformation of VSMCs. To test this, rat aortic smooth muscle cells (RASMCs) were cultured on hydroxyapatite crystals and calcified aortic elastin. Using RT-PCR and specific protein assays, we demonstrate that RASMCs lose their smooth muscle lineage markers like alpha smooth muscle actin (SMA) and myosin heavy chain (MHC) and undergo chondrogenic/osteogenic transformation. This is indicated by an increase in the expression of typical chondrogenic proteins such as aggrecan, collagen type II alpha 1(Col2a1) and bone proteins such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, when calcified conditions are removed, cells return to their original phenotype. Our data supports the hypothesis that elastin degradation and calcification precedes VSMCs' osteoblast-like differentiation. PMID:24447384

Heparin Stimulates Elastogenesis: Application to Silk-Based Vascular Grafts

PubMed Central

Baughman, Cassandra; Kaplan, David L.; Castellot, John J.

2013-01-01

With over 500,000 coronary artery bypass grafts (CABG) performed annually in the United States alone, there is a significant clinical need for a small diameter tissue engineered vascular graft. A principle goal in tissue engineering is to develop materials and growth conditions that encourage appropriate re-cellularization and extracellular matrix formation in vivo. A particular challenge in vascular tissue engineering results from the inability of adult cells to produce elastin, as its expression is developmentally limited. We investigated factors to stimulate elastogenesis in vitro, and found that heparin treatment of adult human vascular smooth muscle cells promoted the formation of elastic fibers. This effect was heparin-specific, and dependent on cell density and growth state. We then applied this information to a silk-based construct, and found that immobilized heparin showed essentially identical biological effects to that of soluble heparin. These findings indicate that heparinized vascular grafts may promote elastin formation and regulate restenosis, in addition to heparin’s well-established antithrombotic properties. Given the increase in elastin mRNA level and the increase in extracellular elastin present, our data suggests that there may be multiple levels of elastin regulation that are mediated by heparin treatment. PMID:21600981

Actin isoform and alpha 1B-adrenoceptor gene expression in aortic and coronary smooth muscle is influenced by cyclical stretch.

PubMed

Lundberg, M S; Sadhu, D N; Grumman, V E; Chilian, W M; Ramos, K S

1995-09-01

The occurrence of vascular domains with specific biological and pharmacological characteristics suggests that smooth muscle cells in different arteries may respond differentially to a wide range of environmental stimuli. To determine if some of these vessel-specific differences may be attributable to mechano-sensitive gene regulation, the influence of cyclical stretch on the expression of actin isoform and alpha 1B-adrenoceptor genes was examined in aortic and coronary smooth muscle cells. Cells were seeded on an elastin substrate and subjected to maximal stretching (24% elongation) and relaxation cycles at a frequency of 120 cycles/min in a Flexercell strain unit for 72 h. Total RNA was extracted and hybridized to radiolabeled cDNA probes to assess gene expression. Stretch caused a greater reduction of actin isoform mRNA levels in aortic smooth muscle cells as compared to cells from the coronary artery. Steady-state mRNA levels of alpha 1B-adrenoceptor were also decreased by cyclical stretch in both cell types but the magnitude of the response was greater in coronary smooth muscle cells. No changes in alpha 1B-adrenoceptor or beta/gamma-actin steady-state mRNA levels were observed in H4IIE cells, a nonvascular, immortalized cell line. The relative gene expression of heat shock protein 70 was not influenced by the cyclic stretch regimen in any of these cell types. These results suggest that stretch may participate in the regulation of gene expression in vascular smooth muscle cells and that this response exhibits some degree of cell-specificity.

Expression and purification of short hydrophobic elastin-like polypeptides with maltose-binding protein as a solubility tag.

PubMed

Bataille, Laure; Dieryck, Wilfrid; Hocquellet, Agnès; Cabanne, Charlotte; Bathany, Katell; Lecommandoux, Sébastien; Garbay, Bertrand; Garanger, Elisabeth

2015-06-01

Elastin-like polypeptides (ELPs) are biodegradable polymers with interesting physico-chemical properties for biomedical and biotechnological applications. The recombinant expression of hydrophobic elastin-like polypeptides is often difficult because they possess low transition temperatures, and therefore form aggregates at sub-ambient temperatures. To circumvent this difficulty, we expressed in Escherichia coli three hydrophobic ELPs (VPGIG)n with variable lengths (n=20, 40, and 60) in fusion with the maltose-binding protein (MBP). Fusion proteins were soluble and yields of purified MBP-ELP ranged between 66 and 127mg/L culture. After digestion of the fusion proteins by enterokinase, the ELP moiety was purified by using inverse transition cycling. The purified fraction containing ELP40 was slightly contaminated by traces of undigested fusion protein. Purification of ELP60 was impaired because of co-purification of the MBP tag during inverse transition cycling. ELP20 was successfully purified to homogeneity, as assessed by gel electrophoresis and mass spectrometry analyses. The transition temperature of ELP20 was measured at 15.4°C in low salt buffer. In conclusion, this method can be used to produce hydrophobic ELP of low molecular mass. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation and characterization of human smooth muscle cell lines derived from atherosclerotic plaque.

PubMed

Bonin, L R; Madden, K; Shera, K; Ihle, J; Matthews, C; Aziz, S; Perez-Reyes, N; McDougall, J K; Conroy, S C

1999-03-01

The study of atherogenesis in humans has been restricted by the limited availability and brief in vitro life span of plaque smooth muscle cells (SMCs). We describe plaque SMC lines with extended life spans generated by the expression of the human papillomavirus (HPV)-16 E6 and E7 genes, which has been shown to extend the life span of normal adult human aortic SMCs. Resulting cell lines (pdSMC1A and 2) demonstrated at least 10-fold increases in life span; pdSMC1A became immortal. The SMC identity of both pdSMC lines was confirmed by SM22 mRNA expression. pdSMC2 were generally diploid but with various structural and numerical alterations; pdSMC1A demonstrated several chromosomal abnormalities, most commonly -Y, +7, -13, anomalies previously reported in both primary pdSMCs and atherosclerotic tissue. Confluent pdSMC2 appeared grossly similar to HPV-16 E6/E7-expressing normal adult aortic SMCs (AASMCs), exhibiting typical SMC morphology/growth patterns; pdSMC1A displayed irregular cell shape/organization with numerous mitotic figures. Dedifferentiation to a synthetic/proliferative phenotype has been hypothesized as a critical step in atherogenesis, because rat neonatal SMCs and adult intimal SMCs exhibit similar gene expression patterns. To confirm that our pdSMC lines likewise express this apparent plaque phenotype, osteopontin, platelet-derived growth factor B, and elastin mRNA levels were determined in pdSMC1A, pdSMC2, and AASMCs. However, no significant increases in osteopontin or platelet-derived growth factor B expression levels were observed in either pdSMC compared with AASMCs. pdSMC2 alone expressed high levels of elastin mRNA. Lower levels of SM22 mRNA in pdSMC1A suggested greater dedifferentiation and/or additional population doublings in pdSMC1A relative to pdSMC2. Both pdSMC lines (particularly 1A) demonstrated high message levels for matrix Gla protein, previously reported to be highly expressed by human neointimal SMCs in vitro. These results describe 2 novel plaque cell lines exhibiting various features of plaque SMC biology; pdSMC2 may represent an earlier plaque SMC phenotype, whereas pdSMC1A may be representative of cells comprising an advanced atherosclerotic lesion.

Clusterin associates with altered elastic fibers in human photoaged skin and prevents elastin from ultraviolet-induced aggregation in vitro.

PubMed

Janig, Elke; Haslbeck, Martin; Aigelsreiter, Ariane; Braun, Nathalie; Unterthor, Daniela; Wolf, Peter; Khaskhely, Noor M; Buchner, Johannes; Denk, Helmut; Zatloukal, Kurt

2007-11-01

Clusterin is a secreted glycoprotein with stress-induced expression in various diseased and aged tissues. It shares basic features with small heat shock proteins because it may stabilize proteins in a folding-competent state. Besides its presence in all human body fluids, clusterin associates with altered extracellular matrix proteins, such as beta-amyloid in Alzheimer senile plaques in the brain. Because dermal connective tissue alterations occur because of aging and UV radiation, we explored the occurrence of clusterin in young, aged, and sun-exposed human skin. Immunohistochemical analysis showed that clusterin is constantly associated with altered elastic fibers in aged human skin. Elastotic material of sun-damaged skin (solar elastosis), in particular, revealed a strong staining for clusterin. Because of the striking co-localization of clusterin with abnormal elastic material, we investigated the interaction of clusterin with elastin in vitro. A chaperone assay was established in which elastin was denatured by UV irradiation in the absence or presence of clusterin. This assay demonstrated that clusterin exerted a chaperone-like activity and effectively inhibited UV-induced aggregation of elastin. The interaction of both proteins was further analyzed by electron microscopy, size exclusion chromatography, and mass spectrometry, in which clusterin was found in a stable complex with elastin after UV exposure.

Clusterin Associates with Altered Elastic Fibers in Human Photoaged Skin and Prevents Elastin from Ultraviolet-Induced Aggregation in Vitro

PubMed Central

Janig, Elke; Haslbeck, Martin; Aigelsreiter, Ariane; Braun, Nathalie; Unterthor, Daniela; Wolf, Peter; Khaskhely, Noor M.; Buchner, Johannes; Denk, Helmut; Zatloukal, Kurt

2007-01-01

Clusterin is a secreted glycoprotein with stress-induced expression in various diseased and aged tissues. It shares basic features with small heat shock proteins because it may stabilize proteins in a folding-competent state. Besides its presence in all human body fluids, clusterin associates with altered extracellular matrix proteins, such as β-amyloid in Alzheimer senile plaques in the brain. Because dermal connective tissue alterations occur because of aging and UV radiation, we explored the occurrence of clusterin in young, aged, and sun-exposed human skin. Immunohistochemical analysis showed that clusterin is constantly associated with altered elastic fibers in aged human skin. Elastotic material of sun-damaged skin (solar elastosis), in particular, revealed a strong staining for clusterin. Because of the striking co-localization of clusterin with abnormal elastic material, we investigated the interaction of clusterin with elastin in vitro. A chaperone assay was established in which elastin was denatured by UV irradiation in the absence or presence of clusterin. This assay demonstrated that clusterin exerted a chaperone-like activity and effectively inhibited UV-induced aggregation of elastin. The interaction of both proteins was further analyzed by electron microscopy, size exclusion chromatography, and mass spectrometry, in which clusterin was found in a stable complex with elastin after UV exposure. PMID:17872975

[Expression of collagen and elastin fibers in the rectum of patients with obstructed defecation syndrome and its significance].

PubMed

Li, Juan; Lin, Hongcheng; Ren, Donglin

2015-12-01

To detect the expression of collagen and elastin fibers in the rectum of patients with obstructive defecation syndrome (ODS), and to explore the possible role of these fibers in the pathogenesis of ODS. The rectum specimens of 20 patients with ODS were collected. These patients had undergone stapled transanal rectal resection (STARR) surgery in our hospital since 2012. Full-thickness rectal specimens were stained with Masson and EVG staining to show collagen and elastin fibers. As the control, rectum specimens of 20 patients with severe prolapsed hemorrhoids also undergoing STARR surgery in our hospital during the same period were collected. Masson staining showed that the structure of collagen fibers in submucosa was slender, area decreased [(13.88±7.02)% vs. (30.98±3.46)%, P<0.01], and the expression level was significantly lower in ODS group compared with control group. EVG staining also showed that collagen fiber area of ODS patients was reduced compared with control group [(17.18±7.24)% vs. (27.04±9.65)%, P<0.01]. Meanwhile EVG staining revealed that elastic fibers were fragmented in ODS group and the expression level was lower compared with control group [(1.20±1.39)% vs. (1.47±1.06)%], whereas the difference was not statistically significant(P>0.05). The expression level of collagen fibers in patients with ODS is significantly reduced, which may play an important role in the pathogenesis of ODS.

Silk-elastin-like protein biomaterials for the controlled delivery of therapeutics.

PubMed

Huang, Wenwen; Rollett, Alexandra; Kaplan, David L

2015-05-01

Genetically engineered biomaterials are useful for controlled delivery owing to their rational design, tunable structure-function, biocompatibility, degradability and target specificity. Silk-elastin-like proteins (SELPs), a family of genetically engineered recombinant protein polymers, possess these properties. Additionally, given the benefits of combining semi-crystalline silk-blocks and elastomeric elastin-blocks, SELPs possess multi-stimuli-responsive properties and tunability, thereby becoming promising candidates for targeted cancer therapeutics delivery and controlled gene release. An overview of SELP biomaterials for drug delivery and gene release is provided. Biosynthetic strategies used for SELP production, fundamental physicochemical properties and self-assembly mechanisms are discussed. The review focuses on sequence-structure-function relationships, stimuli-responsive features and current and potential drug delivery applications. The tunable material properties allow SELPs to be pursued as promising biomaterials for nanocarriers and injectable drug release systems. Current applications of SELPs have focused on thermally-triggered biomaterial formats for the delivery of therapeutics, based on local hyperthermia in tumors or infections. Other prominent controlled release applications of SELPs as injectable hydrogels for gene release have also been pursued. Further biomedical applications that utilize other stimuli to trigger the reversible material responses of SELPs for targeted delivery, including pH, ionic strength, redox, enzymatic stimuli and electric field, are in progress. Exploiting these additional stimuli-responsive features will provide a broader range of functional biomaterials for controlled therapeutics release and tissue regeneration.

In vitro study of RRS HA injectable mesotherapy/biorevitalization product on human skin fibroblasts and its clinical utilization

PubMed Central

Deglesne, Pierre-Antoine; Arroyo, Rodrigo; Ranneva, Evgeniya; Deprez, Philippe

2016-01-01

Mesotherapy/biorevitalization with hyaluronic acid (HA) is a treatment approach currently used for skin rejuvenation. Various products with a wide range of polycomponent formulations are available on the market. Most of these formulations contain noncross-linked HA in combination with a biorevitalization cocktail, formed by various amounts of vitamins, minerals, amino acids, nucleotides, coenzymes, and antioxidants. Although ingredients are very similar among the different products, in vitro and clinical effects may vary substantially. There is a real need for better characterization of these products in terms of their action on human skin or in vitro skin models. In this study, we analyzed the effect of the RRS® (Repairs, Refills, Stimulates) HA injectable medical device on human skin fibroblasts in vitro. Skin fibroblast viability and its capacity to induce the production of key extracellular matrix were evaluated in the presence of different concentrations of RRS HA injectable. Viability was evaluated through colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, and key extracellular matrix genes, type I collagen and elastin, were quantified by quantitative polymerase chain reaction. Results demonstrated that RRS HA injectable could promote human skin fibroblast viability (+15%) and increase fibroblast gene expression of type I collagen and elastin by 9.7-fold and 14-fold in vitro, respectively. These results demonstrate that mesotherapy/biorevitalization products can, at least in vitro, effectively modulate human skin fibroblasts. PMID:26966384

Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro

PubMed Central

Wang, Guo-Qi; Li, Tong-Tong; Li, Zhi-Rui; Zhang, Li-Cheng

2016-01-01

Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria–Bertani medium at negative pressure of −125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A). Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p < 0.01). Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes. PMID:28074188

Elastin structure and its involvement in skin photoageing.

PubMed

Weihermann, A C; Lorencini, M; Brohem, C A; de Carvalho, C M

2017-06-01

Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non-functional deposition of elastic fibers. The occurrence of UV radiation-induced alternative splicing of the elastin gene, which leads to inadequate synthesis of the proteins required for the correct assembly of elastic fibers, is a potential explanation for this phenomenon. Innovative studies have been fundamental for the elucidation of rarely explored photoaging mechanisms and have enabled the identification of effective therapeutic alternatives such as cosmetic products. This review addresses cutaneous photoaging and the changes that affect elastin in this process. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Antiageing Mechanisms of a Standardized Supercritical CO2 Preparation of Black Jack (Bidens pilosa L.) in Human Fibroblasts and Skin Fragments

PubMed Central

Dieamant, Gustavo; Pereda, Maria Del Carmen V.; Nogueira, Cecília; Eberlin, Samara; Facchini, Gustavo; Checon, Juliana Tibério; Cesar, Camila Kappke; Mussi, Lilian; Polezel, Márcio Antonio; Martins-Oliveira, Divino; Di Stasi, Luiz Claudio

2015-01-01

The use of topical retinoids to treat skin disorders and ageing can induce local reactions, while oral retinoids are potent teratogens and produce several unwanted effects. This way, efforts to explore complementary care resources should be supported. Based on this, we evaluate the antiageing effects of a supercritical CO2 extract from Bidens pilosa L. (BPE-CO2A) containing a standardized multicomponent mixture of phytol, linolenic, palmitic, linoleic, and oleic acids. BPE-CO2A was assessed for its effects on human dermal fibroblasts (TGF-β1 and FGF levels using ELISA; collagen, elastin, and glycosaminoglycan by colorimetric assays, and mRNA expression of RXR, RAR, and EGFr by qRT-PCR) and human skin fragments (RAR, RXR, collagen, elastin, and glycosaminoglycan by immunohistochemical analysis). Levels of extracellular matrix elements, TGF-β1 and FGF, and EGFr gene expression were significantly increased by BPE-CO2A. The modulation of RXR and RAR was positively demonstrated after the treatment with BPE-CO2A or phytol, a component of BPE-CO2A. The effects produced by BPE-CO2A were similar to or better than those produced by retinol and retinoic acid. The ability to stimulate extracellular matrix elements, increase growth factors, and modulate retinoid and rexinoid receptors provides a basis for the development of preparation containing BPE-CO2A as an antiageing/skin-repair agent. PMID:25883669

Elastin is a key regulator of outward remodeling in arteriovenous fistulas.

PubMed

Wong, C Y; Rothuizen, T C; de Vries, M R; Rabelink, T J; Hamming, J F; van Zonneveld, A J; Quax, P H A; Rotmans, J I

2015-04-01

Maturation failure is the major limitation of arteriovenous fistulas (AVFs) as hemodialysis access conduits. Indeed, 30-50% of AVFs fail to mature due to intimal hyperplasia and insufficient outward remodeling. Elastin has emerged as an important determinant of vascular remodeling. Here the role of elastin in AVF remodeling in elastin haplodeficient (eln(+/-)) mice undergoing AVF surgery has been studied. Unilateral AVFs between the branch of the jugular vein and carotid artery in an end to side manner were created in wild-type (WT) C57BL/6 (n = 11) and in eln(+/-) mice (n = 9). Animals were killed at day 21 and the AVFs were analyzed histologically and at an mRNA level using real-time quantitative polymerase chain reaction. Before AVF surgery, a marked reduction in elastin density in the internal elastic lamina (IEL) of eln(+/-) mice was observed. AVF surgery resulted in fragmentation of the venous internal elastic lamina in both groups while the expression of the tropoelastin mRNA was 53% lower in the eln(+/-) mice than in WT mice (p < .001). At 21 days after AVF surgery, the circumference of the venous outflow tract of the AVF was 21% larger in the eln(+/-) mice than in the WT mice (p = .037), indicating enhanced outward remodeling in the eln(+/-) mice. No significant difference in intimal hyperplasia was observed. The venous lumen of the AVF in the eln(+/-) mice was 53% larger than in the WT mice, although this difference was not statistically significant (eln(+/-), 350,116 ± 45,073 μm(2); WT, 229,405 ± 40,453 μm(2); p = .064). In a murine model, elastin has an important role in vascular remodeling following AVF creation, in which a lower amount of elastin results in enhanced outward remodeling. Interventions targeting elastin degradation might be a viable option in order to improve AVF maturation. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Nature and Nurture: Williams Syndrome across Cultures

ERIC Educational Resources Information Center

Zitzer-Comfort, Carol; Doyle, Teresa; Masataka, Nobuo; Korenberg, Julie; Bellugi, Ursula

2007-01-01

This study is concerned with ways in which children with Williams syndrome (WS), a rare neurodevelopmental disorder arising from a hemizygous deletion in chromosome band 7q11.23 including the gene for elastin (ELN) and approximately 20 surrounding genes, are affected by social mores of vastly differing cultures: the United States and Japan. WS…

mTOR (Mechanistic Target of Rapamycin) Inhibition Decreases Mechanosignaling, Collagen Accumulation, and Stiffening of the Thoracic Aorta in Elastin-Deficient Mice.

PubMed

Jiao, Yang; Li, Guangxin; Li, Qingle; Ali, Rahmat; Qin, Lingfeng; Li, Wei; Qyang, Yibing; Greif, Daniel M; Geirsson, Arnar; Humphrey, Jay D; Tellides, George

2017-09-01

Elastin deficiency because of heterozygous loss of an ELN allele in Williams syndrome causes obstructive aortopathy characterized by medial thickening and fibrosis and consequent aortic stiffening. Previous work in Eln -null mice with a severe arterial phenotype showed that inhibition of mTOR (mechanistic target of rapamycin), a key regulator of cell growth, lessened the aortic obstruction but did not prevent early postnatal death. We investigated the effects of mTOR inhibition in Eln -null mice partially rescued by human ELN that manifest a less severe arterial phenotype and survive long term. Thoracic aortas of neonatal and juvenile mice with graded elastin deficiency exhibited increased signaling through both mTOR complex 1 and 2. Despite lower predicted wall stress, there was increased phosphorylation of focal adhesion kinase, suggestive of greater integrin activation, and increased transforming growth factor-β-signaling mediators, associated with increased collagen expression. Pharmacological blockade of mTOR by rapalogs did not improve luminal stenosis but reduced mechanosignaling (in delayed fashion after mTOR complex 1 inhibition), medial collagen accumulation, and stiffening of the aorta. Rapalog administration also retarded somatic growth, however, and precipitated neonatal deaths. Complementary, less-toxic strategies to inhibit mTOR via altered growth factor and nutrient responses were not effective. In addition to previously demonstrated therapeutic benefits of rapalogs decreasing smooth muscle cell proliferation in the absence of elastin, we find that rapalogs also prevent aortic fibrosis and stiffening attributable to partial elastin deficiency. Our findings suggest that mTOR-sensitive perturbation of smooth muscle cell mechanosensing contributes to elastin aortopathy. © 2017 American Heart Association, Inc.

Elastase-Induced Parenchymal Disruption and Airway Hyper Responsiveness in Mouse Precision Cut Lung Slices: Toward an Ex vivo COPD Model.

PubMed

Van Dijk, Eline M; Culha, Sule; Menzen, Mark H; Bidan, Cécile M; Gosens, Reinoud

2016-01-01

Background: COPD is a progressive lung disease characterized by emphysema and enhanced bronchoconstriction. Current treatments focused on bronchodilation can delay disease progression to some extent, but recovery or normalization of loss of lung function is impossible. Therefore, novel therapeutic targets are needed. The importance of the parenchyma in airway narrowing is increasingly recognized. In COPD, the parenchyma and extracellular matrix are altered, possibly affecting airway mechanics and enhancing bronchoconstriction. Our aim was to set up a comprehensive ex vivo Precision Cut Lung Slice (PCLS) model with a pathophysiology resembling that of COPD and integrate multiple readouts in order to study the relationship between parenchyma, airway functionality, and lung repair processes. Methods: Lungs of C57Bl/6J mice were sliced and treated ex vivo with elastase (2.5 μg/ml) or H 2 O 2 (200 μM) for 16 h. Following treatment, parenchymal structure, airway narrowing, and gene expression levels of alveolar Type I and II cell repair were assessed. Results: Following elastase, but not H 2 O 2 treatment, slices showed a significant increase in mean linear intercept (Lmi), reflective of emphysema. Only elastase-treated slices showed disorganization of elastin and collagen fibers. In addition, elastase treatment lowered both alveolar Type I and II marker expression, whereas H 2 O 2 stimulation lowered alveolar Type I marker expression only. Furthermore, elastase-treated slices showed enhanced methacholine-induced airway narrowing as reflected by increased pEC50 (5.87 at basal vs. 6.50 after elastase treatment) and Emax values (47.96 vs. 67.30%), and impaired chloroquine-induced airway opening. The increase in pEC50 correlated with an increase in mean Lmi. Conclusion: Using this model, we show that structural disruption of elastin fibers leads to impaired alveolar repair, disruption of the parenchymal compartment, and altered airway biomechanics, enhancing airway contraction. This finding may have implications for COPD, as the amount of elastin fiber and parenchymal tissue disruption is associated with disease severity. Therefore, we suggest that PCLS can be used to model certain aspects of COPD pathophysiology and that the parenchymal tissue damage observed in COPD contributes to lung function decline by disrupting airway biomechanics. Targeting the parenchymal compartment may therefore be a promising therapeutic target in the treatment of COPD.

Structure and applications of a temperature responsive recombinant protein hydrogel based on silk- and elastin-like amino acid motifs

NASA Astrophysics Data System (ADS)

Drummy, Lawrence; Tomczak, Melanie; Macauliffe, Joseph; Vaia, Richard; Naik, Rajesh

2008-03-01

Proteins form the main components of many natural materials, and they can be designed to offer tailored functionality and material properties. Silk elastin-like proteins (SELP)s come from a family of repeat sequence protein polymers based on Bombyx mori silk and mammalian elastin that are recombinantly expressed in E. coli. SELP gels are formed by heating the protein solutions in order to induce physical crosslinking of the silk β-sheet regions, they contain approximately 80-90% water by weight and they can be used for encapsulation of enzymes or nanoparticles. For example, horseradish peroxidase demonstrates added resistance to drying and heat treatment when encapsulated in the gel matrix. During gel formation, small angle X-ray scattering shows intensity increases in two distinct regions of reciprocal space, one reversible with temperature and one irreversible. By fitting the scattering data to a unified power-law/Gunier model, morphological parameters are extracted. The thermally reversible intensity changes are attributed to a hydrophilic/hydrophobic transition in the elastin segments, while the irreversible intensity change is due to the crystalline regions formed by the silk blocks.

Elastin hydrolysate derived from fish enhances proliferation of human skin fibroblasts and elastin synthesis in human skin fibroblasts and improves the skin conditions.

PubMed

Shiratsuchi, Eri; Nakaba, Misako; Yamada, Michio

2016-03-30

Recent studies have shown that certain peptides significantly improve skin conditions, such as skin elasticity and the moisture content of the skin of healthy woman. This study aimed to investigate the effects of elastin hydrolysate on human skin. Proliferation and elastin synthesis were evaluated in human skin fibroblasts exposed to elastin hydrolysate and proryl-glycine (Pro-Gly), which is present in human blood after elastin hydrolysate ingestion. We also performed an ingestion test with elastin hydrolysate in humans and evaluated skin condition. Elastin hydrolysate and Pro-Gly enhanced the proliferation of fibroblasts and elastin synthesis. Maximal proliferation response was observed at 25 ng mL(-1) Pro-Gly. Ingestion of elastin hydrolysate improved skin condition, such as elasticity, number of wrinkles, and blood flow. Elasticity improved by 4% in the elastin hydrolysate group compared with 2% in the placebo group. Therefore, elastin hydrolysate activates human skin fibroblasts and has beneficial effects on skin conditions. © 2015 Society of Chemical Industry.

Serological assessment of neutrophil elastase activity on elastin during lung ECM remodeling.

PubMed

Kristensen, Jacob H; Karsdal, Morten A; Sand, Jannie Mb; Willumsen, Nicholas; Diefenbach, Claudia; Svensson, Birte; Hägglund, Per; Oersnes-Leeming, Diana J

2015-05-03

During the pathological destruction of lung tissue, neutrophil elastase (NE) degrades elastin, one of the major constituents of lung parenchyma. However there are no non-invasive methods to quantify NE degradation of elastin. We selected specific elastin fragments generated by NE for antibody generation and developed an ELISA assay (EL-NE) for the quantification of NE-degraded elastin. Monoclonal antibodies were developed against 10 NE-specific cleavage sites on elastin. One EL-NE assay was tested for analyte stability, linearity and intra- and inter-assay variation. The NE specificity was demonstrated using elastin cleaved in vitro with matrix metalloproteinases (MMPs), cathepsin G (CatG), NE and intact elastin. Clinical relevance was assessed by measuring levels of NE-generated elastin fragments in serum of patients diagnosed with idiopathic pulmonary fibrosis (IPF, n = 10) or lung cancer (n = 40). Analyte recovery of EL-NE for human serum was between 85% and 104%, the analyte was stable for four freeze/thaw cycles and after 24 h storage at 4°C. EL-NE was specific for NE-degraded elastin. Levels of NE-generated elastin fragments for elastin incubated in the presence of NE were 900% to 4700% higher than those seen with CatG or MMP incubation or in intact elastin. Serum levels of NE-generated elastin fragments were significantly increased in patients with IPF (137%, p = 0.002) and in patients with lung cancer (510%, p < 0.001) compared with age- and sex-matched controls. The EL-NE assay was specific for NE-degraded elastin. The EL-NE assay was able to specifically quantify NE-degraded elastin in serum. Serum levels of NE-degraded elastin might be used to detect excessive lung tissue degradation in lung cancer and IPF.

Tunable elastin-like polypeptide hollow sphere as a high payload and controlled delivery gene depot.

PubMed

Dash, Biraja C; Mahor, Sunil; Carroll, Oliver; Mathew, Asha; Wang, Wenxin; Woodhouse, Kimberly A; Pandit, Abhay

2011-06-30

Self-assembly driven processes can be utilized to produce a variety of nanostructures useful for various in vitro and in vivo applications. Characteristics such as size, stability, biocompatibility, high therapeutic loading and controlled delivery of these nanostructures are particularly crucial in relation to in vivo applications. In this study, we report the fabrication of tunable monodispersed elastin-like polypeptide (ELP) hollow spheres of 100, 300, 500 and 1000 nm by exploiting the self-assembly property and net positive charge of ELP. The microbial transglutaminase (mTGase) cross-linking provided robustness and stability to the hollow spheres while maintaining surface functional groups for further modifications. The resulting hollow spheres showed a higher loading efficiency of plasmid DNA (pDNA) by using polyplex (~70 μg pDNA/mg of hollow sphere) than that of self-assembled ELP particles and demonstrated controlled release triggered by protease and elastase. Moreover, polyplex-loaded hollow spheres showed better cell viability than polyplex alone and yielded higher luciferase expression by providing protection against endosomal degradation. Overall, the monodispersed, tunable hollow spheres with a capability of post-functionalization can provide an exciting new opportunity for use in a range of therapeutic and diagnostic applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Elastin aging and lipid oxidation products in human aorta.

PubMed

Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

2015-01-01

Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Elastin aging and lipid oxidation products in human aorta

PubMed Central

Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

2014-01-01

Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. PMID:25553420

The development of a novel wound healing material, silk-elastin sponge.

PubMed

Kawabata, Shingo; Kawai, Katsuya; Somamoto, Satoshi; Noda, Kazuo; Matsuura, Yoshitaka; Nakamura, Yoko; Suzuki, Shigehiko

2017-12-01

Silk-elastin is a recombinant protein polymer with repeating units of silk and elastin blocks. This novel wound healing promoting material has the ability to self-assemble from a liquid to a gel. We have already reported that an aqueous solution of silk-elastin has the potential to accelerate wound healing; however, there are several problems in applying silk-elastin in the clinical setting. To solve these problems, we developed a silk-elastin sponge that is easy to use in the clinical setting. In the present study, we examined whether the wound healing effect of the silk-elastin sponge is equal to the aqueous solution of silk-elastin in vivo. The granulation tissue formation promoting effect of the silk-elastin sponge was equal to that of the aqueous solution the silk-elastin, as after application to the wound surface, the sponge was absorbed and dissolved by the exudate. At body temperature the silk-elastin then formed temperature gel. The silk-elastin gel that was obtained contained abundant cytokines from the exudate. We believe that silk-elastin sponge can be applied to various wounds that are difficult to treat with the aqueous solution.

Expression and purification of moricin CM4 and human β-defensins 4 in Escherichia coli using a new technology.

PubMed

Shen, Yang; Ai, Hong-Xin; Song, Ren; Liang, Zhen-Ning; Li, Jian-Feng; Zhang, Shuang-Quan

2010-10-20

Different strategies have been developed to produce small antimicrobial peptides using recombinant techniques. Here we report a new technology of biosynthesis of moricin CM4 and human β-defensins 4 (HβD4) in the Escherichia coli. The CM4 and HβD4 gene were cloned into a vector containing the tags elastin-like peptide (ELP) and intein to construct the expression vector pET-EI-CM4 and pET-EI-HβD4. All the peptides, expressed as soluble fusions, were isolated from the protein debris by the method called inverse transition cycling (ITC) rather than traditional immobilized metal affinity chromatography (IMAC) and separated from the fusion leader by self-cleavage. Fully reduced peptides that were purified exhibited expected antimicrobial activity. The approach described here is a low-cost, convenient and potential way for generating small antimicrobial peptide. Copyright © 2010 Elsevier GmbH. All rights reserved.

Procyanidins-crosslinked aortic elastin scaffolds with distinctive anti-calcification and biological properties.

PubMed

Wang, Xiaoya; Zhai, Wanyin; Wu, Chengtie; Ma, Bing; Zhang, Jiamin; Zhang, Hongfeng; Zhu, Ziyan; Chang, Jiang

2015-04-01

Elastin, a main component of decellularized extracellular matrices and elastin-containing materials, has been used for tissue engineering applications due to their excellent biocompatibility. However, elastin is easily calcified, leading to the decrease of life span for elastin-based substitutes. How to inhibit the calcification of elastin-based scaffolds, but maintain their good biocompatibility, still remains significantly challenging. Procyanidins (PC) are a type of natural polyphenols with crosslinking ability. To investigate whether pure elastin could be crosslinked by PC with anti-calcification effect, PC was first used to crosslink aortic elastin. Results show that PC can crosslink elastin and effectively inhibit elastin-initiated calcification. Further experiments reveal the possible mechanisms for the anti-calcification of PC crosslinking including (1) inhibiting inflammation cell attachment, and secretion of inflammatory factors such as MMPs and TNF-α, (2) preventing elastin degradation by elastase, and (3) direct inhibition of mineral nucleation in elastin. Moreover, the PC-crosslinked aortic elastin maintains natural structure with high pore volume (1111 μL/g), large pore size (10-300 μm) and high porosity (75.1%) which facilitates recellularization of scaffolds in vivo, and displays excellent hemocompatibility, anti-thrombus and anti-inflammatory potential. The advantages of PC-crosslinked porous aortic elastin suggested that it can serve as a promising scaffold for tissue engineering. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Transcriptome-Wide Expression Profiling in Skin Fibroblasts of Patients with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome Hypermobility Type.

PubMed

Chiarelli, Nicola; Carini, Giulia; Zoppi, Nicoletta; Dordoni, Chiara; Ritelli, Marco; Venturini, Marina; Castori, Marco; Colombi, Marina

2016-01-01

Joint hypermobility syndrome/Ehlers-Danlos syndrome hypermobility type (JHS/EDS-HT), is likely the most common systemic heritable connective tissue disorder, and is mostly recognized by generalized joint hypermobility, joint instability complications, minor skin changes and a wide range of satellite features. JHS/EDS-HT is considered an autosomal dominant trait but is still without a defined molecular basis. The absence of (a) causative gene(s) for JHS/EDS-HT is likely attributable to marked genetic heterogeneity and/or interaction of multiple loci. In order to help in deciphering such a complex molecular background, we carried out a comprehensive immunofluorescence analysis and gene expression profiling in cultured skin fibroblasts from five women affected with JHS/EDS-HT. Protein study revealed disarray of several matrix structural components such as fibrillins, tenascins, elastin, collagens, fibronectin, and their integrin receptors. Transcriptome analysis indicated perturbation of different signaling cascades that are required for homeostatic regulation either during development or in adult tissues as well as altered expression of several genes involved in maintenance of extracellular matrix architecture and homeostasis (e.g., SPON2, TGM2, MMP16, GPC4, SULF1), cell-cell adhesion (e.g., CDH2, CHD10, PCDH9, CLDN11, FLG, DSP), immune/inflammatory/pain responses (e.g., CFD, AQP9, COLEC12, KCNQ5, PRLR), and essential for redox balance (e.g., ADH1C, AKR1C2, AKR1C3, MAOB, GSTM5). Our findings provide a picture of the gene expression profile and dysregulated pathways in JHS/EDS-HT skin fibroblasts that correlate well with the systemic phenotype of the patients.

Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo.

PubMed

Li, Wen-Hwa; Wong, Heng-Kuan; Serrano, José; Randhawa, Manpreet; Kaur, Simarna; Southall, Michael D; Parsa, Ramine

2017-05-01

Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

Liberation of Desmosine and Isodesmosine as Amino Acids from Insoluble Elastin by Elastolytic Proteases

PubMed Central

Umeda, Hideyuki; Aikawa, Masanori; Libby, Peter

2011-01-01

The development of atherosclerotic lesions and abdominal aortic aneurysms involves degradation and loss of extracellular matrix components, such as collagen and elastin. Releases of the elastin cross-links desmosine (DES) and isodesmosine (IDE) may reflect elastin degradation in cardiovascular diseases. This study investigated the production of soluble elastin cross-linking structures by proteinases implicated in arterial diseases. Recombinant MMP-12 and neutrophil elastase liberated DES and IDE as amino acids from insoluble elastin. DES and IDE were also released from insoluble elastin exposed to monocyte/macrophage cell lines or human primary macrophages derived from peripheral blood monocytes. Elastin oxidized by reactive oxygen species (ROS) liberated more unconjugated DES and IDE than did non-oxidized elastin when incubated with MMP-12 or neutrophil elastase. These results support the exploration of free DES and IDE as biomarkers of elastin degradation. PMID:21726534

Soluble elastin peptides in cardiovascular homeostasis: Foe or ally.

PubMed

Qin, Zhenyu

2015-05-01

Elastin peptides, also known as elastin-derived peptides or elastokines, are soluble polypeptides in blood and tissue. The blood levels of elastin peptides are usually low but can increase during cardiovascular diseases, such as atherosclerosis, aortic aneurysm and diabetes with vascular complications. Generally, elastin peptides are derived from the degradation of insoluble elastic polymers. The biological activities of elastin peptides are bidirectional, e.g., a pro-inflammatory effect on monocyte migration induction vs. a protective effect on vasodilation promotion. However, recent in vivo studies have demonstrated that elastin peptides promote the formation of atherosclerotic plaques in hypercholesterolemic mice and induce hyperglycemia and elevations in plasma lipid levels in fasted mice. More important, the detrimental effects induced by elastin peptides can be largely inhibited by genetic or pharmacological blockade of the elastin receptor complex or by neutralization of an antibody against elastin peptides. These studies indicate new therapeutic strategies for the treatment of cardiovascular diseases by targeting elastin peptide metabolism. Therefore, the goal of this review is to summarize current knowledge about elastin peptides relevant to cardiovascular pathologies to further delineate their potential application in cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Contribution of elastin and collagen to the inflation response of the pig thoracic aorta: assessing elastin's role in mechanical homeostasis.

PubMed

Lillie, M A; Armstrong, T E; Gérard, S G; Shadwick, R E; Gosline, J M

2012-08-09

This study was undertaken to understand elastin's role in the mechanical homeostasis of the arterial wall. The mechanical properties of elastin vary along the aorta, and we hypothesized this maintained a uniform mechanical environment for the elastin, despite regional variation in loading. Elastin's physiological loading was determined by comparing the inflation response of intact and autoclave purified elastin aortas from the proximal and distal thoracic aorta. Elastin's stretch and stress depend on collagen recruitment. Collagen recruitment started in the proximal aorta at systolic pressures (13.3 to 14.6 kPa) and in the distal at sub-diastolic pressures (9.3 to 10.6 kPa). In the proximal aorta collagen did not contribute significantly to the stress or stiffness, indicating that elastin determined the vessel properties. In the distal aorta, the circumferential incremental modulus was 70% higher than in the proximal aorta, half of which (37%) was due to a stiffening of the elastin. Compared to the elastin tissue in the proximal aorta, the distal elastin suffered higher physiological circumferential stretch (29%, P=0.03), circumferential stress (39%, P=0.02), and circumferential stiffness (37%, P=0.006). Elastin's physiological axial stresses were also higher (67%, P=0.003). These findings do not support the hypothesis that the loading on elastin is constant along the aorta as we expected from homeostasis. Copyright © 2012 Elsevier Ltd. All rights reserved.

An injectable elastin-based gene delivery platform for dose-dependent modulation of angiogenesis and inflammation for critical limb ischemia.

PubMed

Dash, Biraja C; Thomas, Dilip; Monaghan, Michael; Carroll, Oliver; Chen, Xizhe; Woodhouse, Kimberly; O'Brien, Timothy; Pandit, Abhay

2015-10-01

Critical limb ischemia is a major clinical problem. Despite rigorous treatment regimes, there has been only modest success in reducing the rate of amputations in affected patients. Reduced level of blood flow and enhanced inflammation are the two major pathophysiological changes that occur in the ischemic tissue. The objective of this study was to develop a controlled dual gene delivery system capable of delivering therapeutic plasmid eNOS and IL-10 in a temporal manner. In order to deliver multiple therapeutic genes, an elastin-like polypeptide (ELP) based injectable system was designed. The injectable system was comprised of hollow spheres and an in situ-forming gel scaffold of elastin-like polypeptide capable of carrying gene complexes, with an extended manner release profile. In addition, the ELP based injectable system was used to deliver human eNOS and IL-10 therapeutic genes in vivo. A subcutaneous dose response study showed enhanced blood vessel density in the treatment groups of eNOS (20 μg) and IL-10 (10 μg)/eNOS (20 μg) and reduced inflammation with IL-10 (10 μg) alone. Next, we carried out a hind-limb ischemia model comparing the efficacy of the following interventions; Saline; IL-10, eNOS and IL-10/eNOS. The selected dose of eNOS, exhibited enhanced angiogenesis. IL-10 treatment groups showed reduction in the level of inflammatory cells. Furthermore, we demonstrated that eNOS up-regulated major proangiogenic growth factors such as vascular endothelial growth factors, platelet derived growth factor B, and fibroblast growth factor 1, which may explain the mechanism of this approach. These factors help in formation of a stable vascular network. Thus, ELP injectable system mediating non-viral delivery of human IL10-eNOS is a promising therapy towards treating limb ischemia. Copyright © 2015 Elsevier Ltd. All rights reserved.

The OmpL37 surface-exposed protein is expressed by pathogenic Leptospira during infection and binds skin and vascular elastin.

PubMed

Pinne, Marija; Choy, Henry A; Haake, David A

2010-09-07

Pathogenic Leptospira spp. shed in the urine of reservoir hosts into freshwater can be transmitted to a susceptible host through skin abrasions or mucous membranes causing leptospirosis. The infection process involves the ability of leptospires to adhere to cell surface and extracellular matrix components, a crucial step for dissemination and colonization of host tissues. Therefore, the elucidation of novel mediators of host-pathogen interaction is important in the discovery of virulence factors involved in the pathogenesis of leptospirosis. In this study, we assess the functional roles of transmembrane outer membrane proteins OmpL36 (LIC13166), OmpL37 (LIC12263), and OmpL47 (LIC13050), which we recently identified on the leptospiral surface. We determine the capacity of these proteins to bind to host tissue components by enzyme-linked immunosorbent assay. OmpL37 binds elastin preferentially, exhibiting dose-dependent, saturating binding to human skin (K(d), 104±19 nM) and aortic elastin (K(d), 152±27 nM). It also binds fibrinogen (K(d), 244±15 nM), fibrinogen fragment D (K(d), 132±30 nM), plasma fibronectin (K(d), 359±68 nM), and murine laminin (K(d), 410±81 nM). The binding to human skin elastin by both recombinant OmpL37 and live Leptospira interrogans is specifically enhanced by rabbit antiserum for OmpL37, suggesting the involvement of OmpL37 in leptospiral binding to elastin and also the possibility that host-generated antibodies may promote rather than inhibit the adherence of leptospires to elastin-rich tissues. Further, we demonstrate that OmpL37 is recognized by acute and convalescent leptospirosis patient sera and also by Leptospira-infected hamster sera. Finally, OmpL37 protein is detected in pathogenic Leptospira serovars and not in saprophytic Leptospira. Thus, OmpL37 is a novel elastin-binding protein of pathogenic Leptospira that may be promoting attachment of Leptospira to host tissues.

Total Defense + Repair: A Novel Concept in Solar Protection and Skin Rejuvenation.

PubMed

McDaniel, David H; Hamzavi, Iltefat H; Zeichner, Joshua A; Fabi, Sabrina G; Bucay, Vivian W; Harper, Julie C; Comstock, Jody A; Makino, Elizabeth T; Mehta, Rahul C; Vega, Virginia L

2015-07-01

For more than a century, solar radiation has been known to contribute significantly to the extrinsic aging of skin. Until recently, this was almost exclusively attributed to the photodamage caused by ultraviolet (UV) light. However, a growing body of evidence now indicates that both infrared (IR) and visible light may also contribute to extrinsic skin aging. Infrared radiation, comprised of IR-A, IR-B, and IR-C, accounts for 54.3% of the total solar radiation reaching the skin. Studies have shown that IR radiation is also responsible for skin aging. Thus, IR-A radiation regulates hundreds of genes in skin, with roles in extracellular matrix (ECM) homeostasis regulation, apoptosis, cell growth, and stress responses. IR-B and IR-C radiation are primarily responsible for the increase in skin temperature associated with solar exposure, and are implicated in heat-related skin destruction of collagen and elastin, which is characterized by an increase in the expression of matrix metalloproteinases (MMPs). The contribution of visible light to photoaging is less well understood; however, some preliminary indication associates visible light with the upregulation of MMPs' expression, DNA damage, and keratinocyte proliferation. Interestingly, the common denominator that links skin damage to the different solar wavelengths is the enhanced production of reactive molecule species (RMS) and therewith increased oxidative stress. SkinMedica® Total Defense + Repair (TD+R; SkinMedica Inc., an Allergan company, Irvine, CA) is a "superscreen," which combines broad spectrum UV protection with a unique blend of antioxidants (SOL-IR Advanced Antioxidant Complex™) that provide protection from IR radiation while promoting skin repair. Preclinical studies have indicated that TD+R SPF34 prevents the formation of UV-induced sunburn cells and cyclobutane pyrimidine dimers while preserving or improving the expression of ECM genes. In addition, it prevents IR-A-triggered fragmentation of elastin fibers and expression of MMP-1. Initial clinical studies indicate that TDR+R SPF34 reduces the increase in surface temperature seen with IR radiation. A significant improvement in the appearance of lines and wrinkles was reported as early as week 2 in patients using TDR+R SPF34. In summary, we observed that the unique blend of antioxidants present in TD+R acts in harmony with SPF active ingredients, expanding solar protection beyond UV radiation and counterbalancing the deleterious effects of free radicals on skin cells by promoting endogenous repair.

Temperature-sensitive elastin-mimetic dendrimers: Effect of peptide length and dendrimer generation to temperature sensitivity.

PubMed

Kojima, Chie; Irie, Kotaro; Tada, Tomoko; Tanaka, Naoki

2014-06-01

Dendrimers are synthetic macromolecules with unique structure, which are a potential scaffold for peptides. Elastin is one of the main components of extracellular matrix and a temperature-sensitive biomacromolecule. Previously, Val-Pro-Gly-Val-Gly peptides have been conjugated to a dendrimer for designing an elastin-mimetic dendrimer. In this study, various elastin-mimetic dendrimers using different length peptides and different dendrimer generations were synthesized to control the temperature dependency. The elastin-mimetic dendrimers formed β-turn structure by heating, which was similar to the elastin-like peptides. The elastin-mimetic dendrimers exhibited an inverse phase transition, largely depending on the peptide length and slightly depending on the dendrimer generation. The elastin-mimetic dendrimers formed aggregates after the phase transition. The endothermal peak was observed in elastin-mimetic dendrimers with long peptides, but not with short ones. The peptide length and the dendrimer generation are important factors to tune the temperature dependency on the elastin-mimetic dendrimer. Copyright © 2013 Wiley Periodicals, Inc.

Investigation of water-soluble elastin as a multifunctional cosmetic material: Moisturizing and whitening effects.

PubMed

Inoue, Asako; Hikima, Tomohiro; Taniguchi, Suguru; Nose, Takeru; Maeda, Iori

Elastin and collagen are extracellular matrix proteins that are widely distributed in the body. Although elastin essentially functions as a skin moisturizer, there have been few reports on its other fundamental chemical and biological functions. In this study, we investigated the moisturizing and whitening (tyrosinase inhibition) effects of elastin to examine its usefulness as a cosmetic material. Water-soluble hot alkali pig aorta (HAPA)-elastin was prepared from pig aorta using the hot alkali method. HAPA-elastin showed a widely distributed molecular weight and had a coacervation property that mediated reversible self-assembly of its molecules with increasing temperature. Amino acid analysis of HAPA-elastin showed a high content (81.5%) of hydrophobic amino acids such as Gly, Ala, Val, and Pro. Des (desmosine) and Ide (isodesmosine), which are characteristic amino acids of elastin, accounted for more than 0.4% of the total amino acid content. HAPA-elastin showed a moisture-retaining property. The water content of skin samples treated with and without HAPA-elastin was 77.2% ± 7.8% and 49.4% ± 10.1%, respectively. HAPA-elastin also inhibited tyrosinase activity by 11.3% ± 3.9%. The results obtained indicate that elastin has a useful function as a cosmetic material.

Induction and regulation of murine emphysema by elastin peptides.

PubMed

Sellami, Mehdi; Meghraoui-Kheddar, Aïda; Terryn, Christine; Fichel, Caroline; Bouland, Nicole; Diebold, Marie-Daniele; Guenounou, Moncef; Héry-Huynh, Stéphanie; Le Naour, Richard

2016-01-01

Emphysema is the major component of chronic obstructive pulmonary disease (COPD). During emphysema, elastin breakdown in the lung tissue originates from the release of large amounts of elastase by inflammatory cells. Elevated levels of elastin-derived peptides (EP) reflect massive pulmonary elastin breakdown in COPD patients. Only the EP containing the GXXPG conformational motif with a type VIII β-turn are elastin receptor ligands inducing biological activities. In addition, the COOH-terminal glycine residue of the GXXPG motif seems a prerequisite to the biological activity. In this study, we endotracheally instilled C57BL/6J mice with GXXPG EP and/or COOH-terminal glycine deleted-EP whose sequences were designed by molecular dynamics and docking simulations. We investigated their effect on all criteria associated with the progression of murine emphysema. Bronchoalveolar lavages were recovered to analyze cell profiles by flow cytometry and lungs were prepared to allow morphological and histological analysis by immunostaining and confocal microscopy. We observed that exposure of mice to EP elicited hallmark features of emphysema with inflammatory cell accumulation associated with increased matrix metalloproteinases and desmosine expression and of remodeling of parenchymal tissue. We also identified an inactive COOH-terminal glycine deleted-EP that retains its binding-activity to EBP and that is able to inhibit the in vitro and in vivo activities of emphysema-inducing EP. This study demonstrates that EP are key actors in the development of emphysema and that they represent pharmacological targets for an alternative treatment of emphysema based on the identification of EP analogous antagonists by molecular modeling studies. Copyright © 2016 the American Physiological Society.

Hypoxia-Response Element (HRE)–Directed Transcriptional Regulation of the Rat Lysyl Oxidase Gene in Response to Cobalt and Cadmium

PubMed Central

Li, Wande

2013-01-01

Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Computer analysis indicated that at least four hypoxia-response element (HRE) consensuses (5′-ACGTG-3′) exist in the cloned LO promoter. Treatment of rat lung fibroblasts (RFL6) with CoCl2 (Co, 10–100 μM), a chemical hypoxia reagent, enhanced LO mRNA expression and promoter activities. Overexpression of LO was associated with upregulation of hypoxia-inducible factor (HIF)-1α at mRNA levels in cobalt (Co)–treated cells. Thus, LO is a hypoxia-responsive gene. Dominant negative-HIF-1α inhibited LO promoter activities stimulated by Co. Electrophoretic mobility shift, oligonucleotide competition, and in vitro translated HIF-1α binding assays indicated that only one HRE mapped at −387/−383 relative to ATG was functionally active among four consensuses. Site-directed mutation of this HRE significantly diminished the Co-induced and LO promoter-directed expression of the reporter gene. Cadmium (Cd), an inducer of reactive oxygen species, inhibited HIF-1α mRNA expression and HIF-1α binding to the LO gene in Co-treated cells as revealed by RT-PCR and ChIP assays, respectively. Thus, modulation of the HRE activity by Co and Cd plays a critical role in LO gene transactivation. PMID:23161664

Hypoxia-response element (HRE)-directed transcriptional regulation of the rat lysyl oxidase gene in response to cobalt and cadmium.

PubMed

Gao, Song; Zhou, Jing; Zhao, Yinzhi; Toselli, Paul; Li, Wande

2013-04-01

Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Computer analysis indicated that at least four hypoxia-response element (HRE) consensuses (5'-ACGTG-3') exist in the cloned LO promoter. Treatment of rat lung fibroblasts (RFL6) with CoCl2 (Co, 10-100 μM), a chemical hypoxia reagent, enhanced LO mRNA expression and promoter activities. Overexpression of LO was associated with upregulation of hypoxia-inducible factor (HIF)-1α at mRNA levels in cobalt (Co)-treated cells. Thus, LO is a hypoxia-responsive gene. Dominant negative-HIF-1α inhibited LO promoter activities stimulated by Co. Electrophoretic mobility shift, oligonucleotide competition, and in vitro translated HIF-1α binding assays indicated that only one HRE mapped at -387/-383 relative to ATG was functionally active among four consensuses. Site-directed mutation of this HRE significantly diminished the Co-induced and LO promoter-directed expression of the reporter gene. Cadmium (Cd), an inducer of reactive oxygen species, inhibited HIF-1α mRNA expression and HIF-1α binding to the LO gene in Co-treated cells as revealed by RT-PCR and ChIP assays, respectively. Thus, modulation of the HRE activity by Co and Cd plays a critical role in LO gene transactivation.

Elastin distribution in the normal uterus, uterine leiomyomas, adenomyosis and adenomyomas: a comparison.

PubMed

Zheng, Wei-Qiang; Ma, Rong; Zheng, Jian-Ming; Gong, Zhi-Jing

2006-04-01

To describe the histologic distribution of elastin in the nonpregnant human uterus, uterine leiomyomas, adenomyosis and adenomyomas. Uteri were obtained from women undergoing hysterectomy for benign conditions, including 26 cases of uterine leiomyomas, 24 cases of adenomyosis, 18 adenomyomas and 6 cases of autopsy specimens. Specific histochemical staining techniques were employed in order to demonstrate the distribution of elastin. The distribution of elastin components in the uterus was markedly uneven and showed a decreasing gradient from outer to inner myometrium. No elastin was present within leiomyomas, adenomyomas or adenomyosis. The distribution of elastin may help explain the normal function of the myometrium in labor. It implies that the uneven distribution of elastin components and absence of elastin within leiomyomas, adenomyomas and adenomyosis could be of some clinical significance. The altered elastin distribution in disease states may help explain such symptoms as dysmenorrhea in uterine endometriosis.

Vascular nanomedicine: Site specific delivery of elastin stabilizing therapeutics to damaged arteries

NASA Astrophysics Data System (ADS)

Sinha, Aditi

Elastin, a structural protein in the extra-cellular matrix, plays a critical role in the normal functioning of blood vessels. Apart from performing its primary function of providing resilience to arteries, it also plays major role in regulating cell-cell and cell-matrix interactions, response to injury, and morphogenesis. Medial arterial calcification (MAC) and abdominal aortic aneurysm (AAA) are two diseases where the structural and functional integrity of elastin is severely compromised. Although the clinical presentation of MAC and AAA differ, they have one common underlying causative mechanism---pathological degradation of elastin. Hence prevention of elastin degradation in the early stages of MAC and AAA can mitigate, partially if not wholly, the fatal consequences of both the diseases. The work presented here is motivated by the overwhelming statistics of people afflicted by elastin associated cardiovascular diseases and the unavailability of cure for the same. Overall goal of our research is to understand role of elastin degradation in cardiovascular diseases and to develop a targeted vascular drug delivery system that is minimally invasive, biodegradable, and non-toxic, that prevents elastin from degradation. Our hope is that such treatment will also help regenerate elastin, thereby providing a multi-fold treatment option for elasto-degenerative vascular diseases. For this purpose, we have first confirmed the combined role of degraded elastin and hyperglycemia in the pathogenesis of MAC. We have shown that in the absence of degraded elastin and TGF-beta1 (abundantly present in diabetic arteries) vascular smooth muscle cells maintain their homeostatic state, regardless of environmental glucose concentrations. However simultaneous exposure to glucose, elastin peptides and TGF-beta1 causes the pathological transgenesis of vascular cells to osteoblast-like cells. We show that plant derived polyphenols bind to vascular elastin with great affinity resulting in improved resistance to elastolytic digestion. We further show that the same polyphenols interact with monomeric tropoelastin released by the vascular cells and dramatically increasing their self-assembly in-vitro. In addition, we demonstrate the elastogenic ability of these polyphenols in aiding the crosslinking of tropoelastin released by aneurysmal cells converting it into mature elastin. Finally, we developed a nanoparticle system functionalized with elastin antibody on the surface that, upon systemic delivery, can recognize and bind to sites of damaged elastin in the aorta. We are able to show that this nanoparticle system works in representative animal models for MAC and AAA. These nanoparticles demonstrated spatial and functional specificity for degraded elastin. In conclusion, our work is focused on understanding the role of elastin degradation in vascular calcification and aortic aneurysms. We tested approaches to halt elastin degradation and to regenerate elastin in arteries so that homeostasis can be achieved.

Mechanical contribution of lamellar and interlamellar elastin along the mouse aorta.

PubMed

Clark, T E; Lillie, M A; Vogl, A W; Gosline, J M; Shadwick, R E

2015-10-15

The mechanical properties of aortic elastin vary regionally, but the microstructural basis for this variation is unknown. This study was designed to identify the relative contributions of lamellar and interlamellar elastin to circumferential load bearing in the mouse thoracic and abdominal aortas. Forces developed in uniaxial tests of samples of fresh and autoclaved aorta were correlated with elastin content and morphology obtained from histology and multiphoton laser scanning microscopy. Autoclaving should render much of the interlamellar elastin mechanically incompetent. In autoclaved tissue force per unit sample width correlated with lamellar elastin content (P≪0.001) but not total elastin content. In fresh tissue at low strain where elastin dominates the mechanical response, forces were higher than in the autoclaved tissue, but force did not correlate with total elastin content. Therefore although interlamellar elastin likely contributed to the stiffness in the fresh aorta, its contribution appeared not in proportion to its quantity. In both fresh and autoclaved tissue, elastin stiffness consistently decreased along the abdominal aorta, a key area for aneurysm development, and this difference could not be fully accounted for on the basis of either lamellar or total elastin content. These findings are relevant to the development of mathematical models of arterial mechanics, particularly for mouse models of arterial diseases involving elastic tissue. In microstructural based models the quantity of each mural constituent determines its contribution to the total response. This study shows elastin's mechanical response cannot necessarily be accounted for on the basis of fibre quantity, orientation, and modulus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Elastin Calcification and its Prevention with Aluminum Chloride Pretreatment

PubMed Central

Vyavahare, Narendra; Ogle, Matthew; Schoen, Frederick J.; Levy, Robert J.

1999-01-01

Elastin, an abundant structural protein present in the arterial wall, is prone to calcification in a number of disease processes including porcine bioprosthetic heart valve calcification and atherosclerosis. The mechanisms of elastin calcification are not completely elucidated. In the present work, we demonstrated calcification of purified elastin in rat subdermal implants (Ca2+ = 89.73 ± 9.84 μg/mg after 21 days versus control, unimplanted Ca2+ = 0.16 ± 0.04 μg/mg). X-ray diffraction analysis along with resolution enhanced FTIR spectroscopy demonstrated the mineral phase to be a poorly crystalline hydroxyapatite. We investigated the time course of calcification, the effect of glutaraldehyde crosslinking on calcification, and mechanisms of inhibition of elastin calcification by pretreatment with aluminum chloride (AlCl3). Glutaraldehyde pretreatment did not affect calcification (Ca2+ = 89.06 ± 17.93 μg/mg for glutaraldehyde crosslinked elastin versus Ca2+ = 89.73 ± 9.84 μg/mg for uncrosslinked elastin). This may be explained by radioactive (3H) glutaraldehyde studies showing very low reactivity between glutaraldehyde and elastin. Our results further demonstrated that AlCl3 pretreatment of elastin led to complete inhibition of elastin calcification using 21-day rat subdermal implants, irrespective of glutaraldehyde crosslinking (Ca2+ = 0.73–2.15 μg/mg for AlCl3 pretreated elastin versus 89.73 ± 9.84 for untreated elastin). The AlCl3 pretreatment caused irreversible binding of aluminum ions to elastin, as assessed by atomic emission spectroscopy. Moreover, aluminum ion binding altered the spatial configuration of elastin as shown by circular dichroism (CD), Fourier transform infrared (FTIR), and 13C nuclear magnetic resonance (NMR) spectroscopy studies, suggesting a net structural change including a reduction in the extent of β sheet structures and an increase in coil-turn conformations. Thus, it is concluded that purified elastin calcifies in rat subdermal implants, and that the AlCl3-pretreated elastin completely resists calcification due to irreversible aluminum ion binding and subsequent structural alterations caused by AlCl3. PMID:10487855

Molecular cloning of the cDNA and gene for an elastinolytic aspartic proteinase from Aspergillus fumigatus and evidence of its secretion by the fungus during invasion of the host lung.

PubMed Central

Lee, J D; Kolattukudy, P E

1995-01-01

Hydrolysis of structural proteins in the lung by extracellular proteinases secreted by Aspergillus fumigatus is thought to play a significant role in invasive aspergillosis. This fungus was found previously to secrete an elastinolytic serine proteinase and a metalloproteinase. We report that A. fumigatus also secretes an aspartic proteinase (aspergillopepsin F) that can catalyze hydrolysis of the major structural proteins of basement membrane, elastin, collagen, and laminin. The pH optimum for the enzymatic activity was 5.0 with elastin-Congo red as the substrate, and the activity was not significantly inhibited by pepstatin A, diazoacetyl norleucine methylester, and 1,2-epoxy-3-(p-nitrophenoxy) propane. The cDNA and gene encoding this aspartic proteinase were cloned and sequenced. The open reading frame, interrupted by three introns, would encode a protein of 393 amino acids composed of a putative 21-amino-acid signal peptide and a 49-amino-acid propeptide preceding the 323-amino-acid mature protein. The amino acid sequence of A. fumigatus aspartic proteinase has 70, 66, and 67% homology to the sequences of those from Aspergillus oryzae, Aspergillus awamori, and Aspergillus saitoi, respectively. The active-site motif (DTG) and the catalytic aspartic residues characteristic of aspartic proteinases are found in the presently described enzyme, indicating that it belongs to a family of aspartic proteinases. Polyclonal antibodies were produced in rabbits against both the mature and precursor forms of the aspartic proteinase expressed in Escherichia coli. Immunoblotting with both antibodies detected a 39-kDa mature enzyme in the culture supernatant of A. fumigatus. The aspartic proteinase activity was inhibited by the antibodies, suggesting that the aspartic proteinase in the culture supernatant corresponds to the product of the cloned gene. Immunogold electron microscopy showed that the aspartic proteinase was secreted by A. fumigatus invading neutropenic mouse lung and its secretion was directed toward the germ tubes of penetrating hyphae. PMID:7558282

Effects of cell penetrating Notch inhibitory peptide conjugated to elastin-like polypeptide on glioblastoma cells.

PubMed

Opačak-Bernardi, Teuta; Ryu, Jung Su; Raucher, Drazen

2017-07-01

Notch pathway was found to be activated in most glioblastomas (GBMs), underlining the importance of Notch in formation and recurrence of GBM. In this study, a Notch inhibitory peptide, dominant negative MAML (dnMAML), was conjugated to elastin-like polypeptide (ELP) for tumor targeted delivery. ELP is a thermally responsive polypeptide that can be actively and passively targeted to the tumor site by localized application of hyperthermia. This complex was further modified with the addition of a cell penetrating peptide, SynB1, for improved cellular uptake and blood-brain barrier penetration. The SynB1-ELP1-dnMAML was examined for its cellular uptake, cytotoxicity, apoptosis, cell cycle inhibition and the inhibition of target genes' expression. SynB1-ELP1-dnMAML inhibited the growth of D54 and U251 cells by inducing apoptosis and cell cycle arrest, especially in the presence of hyperthermia. Hyperthermia increased overall uptake of the polypeptide by the cells and enhanced the resulting pharmacological effects of dnMAML, showing the inhibition of targets of Notch pathway such as Hes-1 and Hey-L. These results confirm that dnMAML is an effective Notch inhibitor and combination with ELP may allow thermal targeting of the SynB1-ELP1-dnMAML complex in cancer cells while avoiding the dangers of systemic Notch inhibition.

Mechanistic Insights into Elastin Degradation by Pseudolysin, the Major Virulence Factor of the Opportunistic Pathogen Pseudomonas aeruginosa

PubMed Central

Yang, Jie; Zhao, Hui-Lin; Ran, Li-Yuan; Li, Chun-Yang; Zhang, Xi-Ying; Su, Hai-Nan; Shi, Mei; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong

2015-01-01

Pseudolysin is the most abundant protease secreted by Pseudomonas aeruginosa and is the major extracellular virulence factor of this opportunistic human pathogen. Pseudolysin destroys human tissues by solubilizing elastin. However, the mechanisms by which pseudolysin binds to and degrades elastin remain elusive. In this study, we investigated the mechanism of action of pseudolysin on elastin binding and degradation by biochemical assay, microscopy and site-directed mutagenesis. Pseudolysin bound to bovine elastin fibers and preferred to attack peptide bonds with hydrophobic residues at the P1 and P1’ positions in the hydrophobic domains of elastin. The time-course degradation processes of both bovine elastin fibers and cross-linked human tropoelastin by pseudolysin were further investigated by microscopy. Altogether, the results indicate that elastin degradation by pseudolysin began with the hydrophobic domains on the fiber surface, followed by the progressive disassembly of macroscopic elastin fibers into primary structural elements. Moreover, our site-directed mutational results indicate that five hydrophobic residues in the S1-S1’ sub-sites played key roles in the binding of pseudolysin to elastin. This study sheds lights on the pathogenesis of P. aeruginosa infection. PMID:25905792

The Effect of Static Stretch on Elastin Degradation in Arteries

PubMed Central

Chow, Ming-Jay; Choi, Myunghwan; Yun, Seok Hyun; Zhang, Yanhang

2013-01-01

Previously we have shown that gradual changes in the structure of elastin during an elastase treatment can lead to important transition stages in the mechanical behavior of arteries [1]. However, in vivo arteries are constantly being loaded due to systolic and diastolic pressures and so understanding the effects of loading on the enzymatic degradation of elastin in arteries is important. With biaxial tensile testing, we measured the mechanical behavior of porcine thoracic aortas digested with a mild solution of purified elastase (5 U/mL) in the presence of a static stretch. Arterial mechanical properties and biochemical composition were analyzed to assess the effects of mechanical stretch on elastin degradation. As elastin is being removed, the dimensions of the artery increase by more than 20% in both the longitude and circumference directions. Elastin assays indicate a faster rate of degradation when stretch was present during the digestion. A simple exponential decay fitting confirms the time constant for digestion with stretch (0.11±0.04 h−1) is almost twice that of digestion without stretch (0.069±0.028 h−1). The transition from J-shaped to S-shaped stress vs. strain behavior in the longitudinal direction generally occurs when elastin content is reduced by about 60%. Multiphoton image analysis confirms the removal/fragmentation of elastin and also shows that the collagen fibers are closely intertwined with the elastin lamellae in the medial layer. After removal of elastin, the collagen fibers are no longer constrained and become disordered. Release of amorphous elastin during the fragmentation of the lamellae layers is observed and provides insights into the process of elastin degradation. Overall this study reveals several interesting microstructural changes in the extracellular matrix that could explain the resulting mechanical behavior of arteries with elastin degradation. PMID:24358135

Mécano-Stimulation™ of the skin improves sagging score and induces beneficial functional modification of the fibroblasts: clinical, biological, and histological evaluations

PubMed Central

Humbert, Philippe; Fanian, Ferial; Lihoreau, Thomas; Jeudy, Adeline; Elkhyat, Ahmed; Robin, Sophie; Courderot-Masuyer, Carol; Tauzin, Hélène; Lafforgue, Christine; Haftek, Marek

2015-01-01

Background Loss of mechanical tension appears to be the major factor underlying decreased collagen synthesis in aged skin. Numerous in vitro studies have shown the impact of mechanical forces on fibroblasts through mechanotransduction, which consists of the conversion of mechanical signals to biochemical responses. Such responses are characterized by the modulation of gene expression coding not only for extracellular matrix components (collagens, elastin, etc.) but also for degradation enzymes (matrix metalloproteinases [MMPs]) and their inhibitors (tissue inhibitors of metalloproteinases [TIMPs]). A new device providing a mechanical stimulation of the cutaneous and subcutaneous tissue has been used in a simple, blinded, controlled, and randomized study. Materials and methods Thirty subjects (aged between 35 years and 50 years), with clinical signs of skin sagging, were randomly assigned to have a treatment on hemiface. After a total of 24 sessions with Mécano-Stimulation™, biopsies were performed on the treated side and control area for in vitro analysis (dosage of hyaluronic acid, elastin, type I collagen, MMP9; equivalent dermis retraction; GlaSbox®; n=10) and electron microscopy (n=10). Furthermore, before and after the treatment, clinical evaluations and self-assessment questionnaire were done. Results In vitro analysis showed increases in hyaluronic acid, elastin, type I collagen, and MMP9 content along with an improvement of the migratory capacity of the fibroblasts on the treated side. Electron microscopy evaluations showed a clear dermal remodeling in relation with the activation of fibroblast activity. A significant improvement of different clinical signs associated with skin aging and the satisfaction of the subjects were observed, correlated with an improvement of the sagging cheek. Conclusion Mécano-Stimulation is a noninvasive and safe technique delivered by flaps microbeats at various frequencies, which can significantly improve the skin trophicity. Results observed with objective measurements, ie, in vitro assessments and electron microscopy, confirm the firming and restructuring effect clinically observed. PMID:25673979

Biomimetic collagen/elastin meshes for ventral hernia repair in a rat model.

PubMed

Minardi, Silvia; Taraballi, Francesca; Wang, Xin; Cabrera, Fernando J; Van Eps, Jeffrey L; Robbins, Andrew B; Sandri, Monica; Moreno, Michael R; Weiner, Bradley K; Tasciotti, Ennio

2017-03-01

Ventral hernia repair remains a major clinical need. Herein, we formulated a type I collagen/elastin crosslinked blend (CollE) for the fabrication of biomimetic meshes for ventral hernia repair. To evaluate the effect of architecture on the performance of the implants, CollE was formulated both as flat sheets (CollE Sheets) and porous scaffolds (CollE Scaffolds). The morphology, hydrophylicity and in vitro degradation were assessed by SEM, water contact angle and differential scanning calorimetry, respectively. The stiffness of the meshes was determined using a constant stretch rate uniaxial tensile test, and compared to that of native tissue. CollE Sheets and Scaffolds were tested in vitro with human bone marrow-derived mesenchymal stem cells (h-BM-MSC), and finally implanted in a rat ventral hernia model. Neovascularization and tissue regeneration within the implants was evaluated at 6weeks, by histology, immunofluorescence, and q-PCR. It was found that CollE Sheets and Scaffolds were not only biomechanically sturdy enough to provide immediate repair of the hernia defect, but also promoted tissue restoration in only 6weeks. In fact, the presence of elastin enhanced the neovascularization in both sheets and scaffolds. Overall, CollE Scaffolds displayed mechanical properties more closely resembling those of native tissue, and induced higher gene expression of the entire marker genes tested, associated with de novo matrix deposition, angiogenesis, adipogenesis and skeletal muscles, compared to CollE Sheets. Altogether, this data suggests that the improved mechanical properties and bioactivity of CollE Sheets and Scaffolds make them valuable candidates for applications of ventral hernia repair. Due to the elevated annual number of ventral hernia repair in the US, the lack of successful grafts, the design of innovative biomimetic meshes has become a prime focus in tissue engineering, to promote the repair of the abdominal wall, avoid recurrence. Our meshes (CollE Sheets and Scaffolds) not only showed promising mechanical performance, but also allowed for an efficient neovascularization, resulting in new adipose and muscle tissue formation within the implant, in only 6weeks. In addition, our meshes allowed for the use of the same surgical procedure utilized in clinical practice, with the commercially available grafts. This study represents a significant step in the design of bioactive acellular off-the-shelf biomimetic meshes for ventral hernia repair. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Engineering aqueous fiber assembly into silk-elastin-like protein polymers.

PubMed

Zeng, Like; Jiang, Linan; Teng, Weibing; Cappello, Joseph; Zohar, Yitshak; Wu, Xiaoyi

2014-07-01

Self-assembled peptide/protein nanofibers are valuable 1D building blocks for creating complex structures with designed properties and functions. It is reported that the self-assembly of silk-elastin-like protein polymers into nanofibers or globular aggregates in aqueous solutions can be modulated by tuning the temperature of the protein solutions, the size of the silk blocks, and the charge of the elastin blocks. A core-sheath model is proposed for nanofiber formation, with the silk blocks in the cores and the hydrated elastin blocks in the sheaths. The folding of the silk blocks into stable cores--affected by the size of the silk blocks and the charge of the elastin blocks--plays a critical role in the assembly of silk-elastin nanofibers. Furthermore, enhanced hydrophobic interactions between the elastin blocks at elevated temperatures greatly influence the nanoscale features of silk-elastin nanofibers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Circulating elastin peptides, role in vascular pathology.

PubMed

Robert, L; Labat-Robert, J

2014-12-01

The atherosclerotic process starts with the degradation of elastic fibers. Their presence was demonstrated in the circulation as well as several of their biological properties elucidated. We described years ago a procedure to obtain large elastin peptides by organo-alkaline hydrolysis, κ-elastin. This method enabled also the preparation of specific antibodies used to determine elastin peptides, as well as anti-elastin antibodies in body fluids and tissue extracts. Elastin peptides were determined in a large number of human blood samples. Studies were carried out to explore their pharmacological properties. Similar recent studies by other laboratories confirmed our findings and arose new interest in circulating elastin peptides for their biological activities. This recent trend justified the publication of a review of the biological and pathological activities of elastin peptides demonstrated during our previous studies, subject of this article. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

In vitro myogenesis induced by human recombinant elastin-like proteins.

PubMed

D'Andrea, Paola; Scaini, Denis; Ulloa Severino, Luisa; Borelli, Violetta; Passamonti, Sabina; Lorenzon, Paola; Bandiera, Antonella

2015-10-01

Mammalian adult skeletal muscle has a limited ability to regenerate after injury, usage or trauma. A promising strategy for successful regenerative technology is the engineering of bio interfaces that mimic the characteristics of the extracellular matrix. Human elastin-like polypeptides (HELPs) have been synthesized as biomimetic materials that maintain some peculiar properties of the native protein. We developed a novel Human Elastin Like Polypeptide obtained by fusing the elastin-like backbone to a domain present in the α2 chain of type IV collagen, containing two RGD motives. We employed this peptide as adhesion substrate for C2C12 myoblasts and compared its effects to those induced by two other polypeptides of the HELP series. Myoblast adhered to all HELPs coatings, where they assumed morphology and cytoarchitecture that depended on the polypeptide structure. Adhesion to HELPs stimulated at a different extent cell proliferation and differentiation, the expression of Myosin Heavy Chain and the fusion of aligned fibers into multinucleated myotubes. Adhesion substrates significantly altered myotubes stiffness, measured by Atomic Force Microscopy, and differently affected the cells Ca(2+) handling capacity and the maturation of excitation-contraction coupling machinery, evaluated by Ca(2+) imaging. Overall, our findings indicate that the properties of HELP biopolymers can be exploited for dissecting the molecular connections underlying myogenic differentiation and for designing novel substrates for skeletal muscle regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Elastin-like polypeptides: the power of design for smart cell encapsulation.

PubMed

Bandiera, Antonella

2017-01-01

Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

Circulating Anti-Elastin Antibody Levels and Arterial Disease Characteristics: Associations with Arterial Stiffness and Atherosclerosis.

PubMed

Lee, Seung-Hyun; Shin, Kihyuk; Park, Sungha; Kang, Seok-Min; Choi, Donghoon; Lee, Seung-Hyo; Lee, Sang-Hak

2015-11-01

Elastin is a major arterial structural protein, and elastin-derived peptides are related to arterial change. We previously reported on a novel assay developed using aortic elastin peptides; however, its clinical implications remain unclear. In this study, we assessed whether anti-elastin antibody titers reflect the risk of coronary artery disease (CAD) or its characteristics. We included 174 CAD patients and 171 age- and sex-matched controls. Anti-elastin antibody titers were quantified by enzyme-linked immunosorbent assay. Parameters of arterial stiffness, including the augmentation index (AI) and heart-to-femoral pulse wave velocity (hfPWV), were measured non-invasively. The clinical and angiographic characteristics of CAD patients were also evaluated. Associations between anti-elastin levels and vascular characteristics were examined by linear regression analysis. The median blood level of anti-elastin was significantly lower in the CAD group than in the controls [197 arbitrary unit (a.u.) vs. 63 a.u., p<0.001]. Levels of anti-elastin were significantly lower in men and in subjects with hypertension, diabetes mellitus, hyperlipidemia, or high hfPWV. Nevertheless, anti-elastin levels were not dependent on atherothrombotic events or the angiographic severity of CAD. In a multivariate analysis, male sex (β=-0.38, p<0.001), diabetes mellitus (β=-0.62, p<0.001), hyperlipidemia (β=-0.29, p<0.001), and AI (β=-0.006, p=0.02) were ultimately identified as determinants of anti-elastin levels. Lower levels of anti-elastin are related to CAD. The association between antibody titers and CAD is linked to arterial stiffness rather than the advancement of atherosclerosis.

Resveratrol Inhibits Aortic Root Dilatation in the Fbn1C1039G/+ Marfan Mouse Model.

PubMed

Hibender, Stijntje; Franken, Romy; van Roomen, Cindy; Ter Braake, Anique; van der Made, Ingeborg; Schermer, Edith E; Gunst, Quinn; van den Hoff, Maurice J; Lutgens, Esther; Pinto, Yigal M; Groenink, Maarten; Zwinderman, Aeilko H; Mulder, Barbara J M; de Vries, Carlie J M; de Waard, Vivian

2016-08-01

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the fibrillin-1 gene. Patients with MFS are at risk of aortic aneurysm formation and dissection. Usually, blood pressure-lowering drugs are used to reduce aortic events; however, this is not sufficient for most patients. In the aorta of smooth muscle cell-specific sirtuin-1-deficient mice, spontaneous aneurysm formation and senescence are observed. Resveratrol is known to enhance sirtuin-1 activity and to reduce senescence, which prompted us to investigate the effectiveness of resveratrol in inhibition of aortic dilatation in the Fbn1(C1039G/+) MFS mouse model. Aortic senescence strongly correlates with aortic root dilatation rate in MFS mice. However, although resveratrol inhibits aortic dilatation, it only shows a trend toward reduced aortic senescence. Resveratrol enhances nuclear localization of sirtuin-1 in the vessel wall and, in contrast to losartan, does not affect leukocyte infiltration nor activation of SMAD2 and extracellular signal-regulated kinases 1/2 (ERK1/2). Interestingly, specific sirtuin-1 activation (SRT1720) or inhibition (sirtinol) in MFS mice does not affect aortic root dilatation rate, although senescence is changed. Resveratrol reduces aortic elastin breaks and decreases micro-RNA-29b expression coinciding with enhanced antiapoptotic Bcl-2 expression and decreased number of terminal apoptotic cells. In cultured smooth muscle cells, the resveratrol effect on micro-RNA-29b downregulation is endothelial cell and nuclear factor κB-dependent. Resveratrol inhibits aortic root dilatation in MFS mice by promoting elastin integrity and smooth muscle cell survival, involving downregulation of the aneurysm-related micro-RNA-29b in the aorta. On the basis of these data, resveratrol holds promise as a novel intervention strategy for patients with MFS. © 2016 The Authors.

Resveratrol Inhibits Aortic Root Dilatation in the Fbn1C1039G/+ Marfan Mouse Model

PubMed Central

Hibender, Stijntje; Franken, Romy; van Roomen, Cindy; ter Braake, Anique; van der Made, Ingeborg; Schermer, Edith E.; Gunst, Quinn; van den Hoff, Maurice J.; Lutgens, Esther; Pinto, Yigal M.; Groenink, Maarten; Zwinderman, Aeilko H.; Mulder, Barbara J.M.; de Vries, Carlie J.M.

2016-01-01

Objective— Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the fibrillin-1 gene. Patients with MFS are at risk of aortic aneurysm formation and dissection. Usually, blood pressure–lowering drugs are used to reduce aortic events; however, this is not sufficient for most patients. In the aorta of smooth muscle cell–specific sirtuin-1–deficient mice, spontaneous aneurysm formation and senescence are observed. Resveratrol is known to enhance sirtuin-1 activity and to reduce senescence, which prompted us to investigate the effectiveness of resveratrol in inhibition of aortic dilatation in the Fbn1C1039G/+ MFS mouse model. Approach and Results— Aortic senescence strongly correlates with aortic root dilatation rate in MFS mice. However, although resveratrol inhibits aortic dilatation, it only shows a trend toward reduced aortic senescence. Resveratrol enhances nuclear localization of sirtuin-1 in the vessel wall and, in contrast to losartan, does not affect leukocyte infiltration nor activation of SMAD2 and extracellular signal–regulated kinases 1/2 (ERK1/2). Interestingly, specific sirtuin-1 activation (SRT1720) or inhibition (sirtinol) in MFS mice does not affect aortic root dilatation rate, although senescence is changed. Resveratrol reduces aortic elastin breaks and decreases micro-RNA-29b expression coinciding with enhanced antiapoptotic Bcl-2 expression and decreased number of terminal apoptotic cells. In cultured smooth muscle cells, the resveratrol effect on micro-RNA-29b downregulation is endothelial cell and nuclear factor κB-dependent. Conclusions— Resveratrol inhibits aortic root dilatation in MFS mice by promoting elastin integrity and smooth muscle cell survival, involving downregulation of the aneurysm-related micro-RNA-29b in the aorta. On the basis of these data, resveratrol holds promise as a novel intervention strategy for patients with MFS. PMID:27283746

Fabricated Elastin.

PubMed

Yeo, Giselle C; Aghaei-Ghareh-Bolagh, Behnaz; Brackenreg, Edwin P; Hiob, Matti A; Lee, Pearl; Weiss, Anthony S

2015-11-18

The mechanical stability, elasticity, inherent bioactivity, and self-assembly properties of elastin make it a highly attractive candidate for the fabrication of versatile biomaterials. The ability to engineer specific peptide sequences derived from elastin allows the precise control of these physicochemical and organizational characteristics, and further broadens the diversity of elastin-based applications. Elastin and elastin-like peptides can also be modified or blended with other natural or synthetic moieties, including peptides, proteins, polysaccharides, and polymers, to augment existing capabilities or confer additional architectural and biofunctional features to compositionally pure materials. Elastin and elastin-based composites have been subjected to diverse fabrication processes, including heating, electrospinning, wet spinning, solvent casting, freeze-drying, and cross-linking, for the manufacture of particles, fibers, gels, tubes, sheets and films. The resulting materials can be tailored to possess specific strength, elasticity, morphology, topography, porosity, wettability, surface charge, and bioactivity. This extraordinary tunability of elastin-based constructs enables their use in a range of biomedical and tissue engineering applications such as targeted drug delivery, cell encapsulation, vascular repair, nerve regeneration, wound healing, and dermal, cartilage, bone, and dental replacement. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabricated elastin

PubMed Central

Yeo, Giselle C.; Weiss, Anthony S.

2015-01-01

The mechanical stability, elasticity, inherent bioactivity, and self-assembly properties of elastin make it a highly attractive candidate for the fabrication of versatile biomaterials. The ability to engineer specific peptide sequences derived from elastin allows for precise control of these physicochemical and organizational characteristics, and further broadens the diversity of elastin-based applications. Elastin and elastin-like peptides can also be modified or blended with other natural or synthetic moieties, including peptides, proteins, polysaccharides and polymers, to augment existing capabilities or confer additional architectural and biofunctional features to compositionally pure materials. Elastin and elastin-based composites have been subjected to diverse fabrication processes, including heating, electrospinning, wet spinning, solvent casting, freeze-drying, and cross-linking, for the manufacture of particles, fibers, gels, tubes, sheets and films. The resulting materials can be tailored to possess specific strength, elasticity, morphology, topography, porosity, wettability, surface charge and bioactivity. This extraordinary tunability of elastin-based constructs enables their use in a range of biomedical and tissue engineering applications such as targeted drug delivery, cell encapsulation, vascular repair, nerve regeneration, wound healing, and dermal, cartilage, bone and dental replacement. PMID:25771993

Human skin gene expression: Natural (trans) resveratrol versus five resveratrol analogs for dermal applications.

PubMed

Lephart, Edwin D; Andrus, Merritt B

2017-09-01

Resveratrol (RV) is a polyphenolic compound naturally produced by plants. Polyphenolic compounds incorporated into medicinal products are beneficial but, RV is rapidly metabolized with an associated decline in biological activity. This study tested RV as the standard and compared five structurally modified RV analogs: butyrate, isobutyrate, palmitoate, acetate, and diacetate (to improve functionality) at 1% concentration(s) for 24 h in epiderm full thickness cultures by gene array/qPCR mRNA analysis. When silent mating type information regulation 2 homolog 1, extracellular elements (collagen1A1, 3A1, 4A1; elastin, tissue inhibitor of matrix metalloproteinase 1, fibrillin 1 laminin beta1 and matrix metalloproteinase 9), anti-aging and aging genes, inflammatory biomarkers (interleukin-1A [IL1A], IL1R2, IL-6 and IL-8), nerve growth factor, and the antioxidants (proliferating cell nuclear antigen, catalase, superoxide dismutase and metallothionein 1H/2H) were evaluated, ranking each from highest-to-lowest for gene expression: butyrate > isobutyrate > diacetate > acetate > palmitoate. This study showed that the butyrate and isobutyrate analogs are more biologically active compared to resveratrol and have potential use in topical applications to improve dermal and other health applications. Impact statement Resveratrol has been reported to have a wide variety of health benefits but its rapid metabolism especially after oral ingestion results in very low bioavailability. Notably, the first human skin gene expression study of resveratrol was not published until 2014. The purpose of this study was to determine if increased stability and biological activity could be obtained by modifying the chemical structure of natural (trans) resveratrol and quantifying human gene expression by qPCR of skin biomarkers that enhance dermal health. Five resveratrol analogs were synthesized that increased their lipophilic index to enhance tissue penetration and augment biological activities on the measured parameters that expand the current knowledge of structure/function relationships. The butyrate and isobutyrate modifications displayed gene expression values significantly above resveratrol and suggest that oral application of these and potentially other resveratrol analogs may yield similar results to improve stability and biological activity to benefit/address various disorders/diseases.

Elastin Fiber Accumulation in Liver Correlates with the Development of Hepatocellular Carcinoma.

PubMed

Yasui, Yutaka; Abe, Tokiya; Kurosaki, Masayuki; Higuchi, Mayu; Komiyama, Yasuyuki; Yoshida, Tsubasa; Hayashi, Tsuguru; Kuwabara, Konomi; Takaura, Kenta; Nakakuki, Natsuko; Takada, Hitomi; Tamaki, Nobuharu; Suzuki, Shoko; Nakanishi, Hiroyuki; Tsuchiya, Kaoru; Itakura, Jun; Takahashi, Yuka; Hashiguchi, Akinori; Sakamoto, Michiie; Izumi, Namiki

2016-01-01

The fibrosis stage, which is evaluated by the distribution pattern of collagen fibers, is a major predictor for the development of hepatocellular carcinoma (HCC) for patients with hepatitis C. Meanwhile, the role of elastin fibers has not yet been elucidated. The present study was conducted to determine the significance of quantifying both collagen and elastin fibers. We enrolled 189 consecutive patients with hepatitis C and advanced fibrosis. Using Elastica van Gieson-stained whole-slide images of pretreatment liver biopsies, collagen and elastin fibers were evaluated pixel by pixel (0.46 μm/pixel) using an automated computational method. Consequently, fiber amount and cumulative incidences of HCC within 3 years were analyzed. There was a significant correlation between collagen and elastin fibers, whereas variation in elastin fiber was greater than in collagen fiber. Both collagen fiber (p = 0.008) and elastin fiber (p < 0.001) were significantly correlated with F stage. In total, 30 patients developed HCC during follow-up. Patients who have higher elastin fiber (p = 0.002) in addition to higher collagen fiber (p = 0.05) showed significantly higher incidences of HCC. With regard to elastin fiber, this difference remained significant in F3 patients. Furthermore, for patients with a higher collagen fiber amount, higher elastin was a significant predictor for HCC development (p = 0.02). Computational analysis is a novel technique for quantification of fibers with the added value of conventional staging. Elastin fiber is a predictor for the development of HCC independently of collagen fiber and F stage.

Impaired revascularization in a mouse model of type 2 diabetes is associated with dysregulation of a complex angiogenic-regulatory network.

PubMed

Schiekofer, Stephan; Galasso, Gennaro; Sato, Kaori; Kraus, Benjamin J; Walsh, Kenneth

2005-08-01

Diabetes is a risk factor for the development of cardiovascular diseases associated with impaired angiogenesis or increased endothelial cell apoptosis. Here it is shown that angiogenic repair of ischemic hindlimbs was impaired in Lepr(db/db) mice, a leptin receptor-deficient model of diabetes, compared with wild-type (WT) C57BL/6 mice, as evaluated by laser Doppler flow and capillary density analyses. To identify molecular targets associated with this disease process, hindlimb cDNA expression profiles were created from adductor muscle of Lepr(db/db) and WT mice before and after hindlimb ischemia using Affymetrix GeneChip Mouse Expression Set microarrays. The expression patterns of numerous angiogenesis-related proteins were altered in Lepr(db/db) versus WT mice after ischemic injury. These transcripts included neuropilin-1, vascular endothelial growth factor-A, placental growth factor, elastin, and matrix metalloproteinases implicated in blood vessel growth and maintenance of vessel wall integrity. These data illustrate that impaired ischemia-induced neovascularization in type 2 diabetes is associated with the dysregulation of a complex angiogenesis-regulatory network.

Circulating Anti-Elastin Antibody Levels and Arterial Disease Characteristics: Associations with Arterial Stiffness and Atherosclerosis

PubMed Central

Lee, Seung-Hyun; Shin, Kihyuk; Park, Sungha; Kang, Seok-Min; Choi, Donghoon

2015-01-01

Purpose Elastin is a major arterial structural protein, and elastin-derived peptides are related to arterial change. We previously reported on a novel assay developed using aortic elastin peptides; however, its clinical implications remain unclear. In this study, we assessed whether anti-elastin antibody titers reflect the risk of coronary artery disease (CAD) or its characteristics. Materials and Methods We included 174 CAD patients and 171 age- and sex-matched controls. Anti-elastin antibody titers were quantified by enzyme-linked immunosorbent assay. Parameters of arterial stiffness, including the augmentation index (AI) and heart-to-femoral pulse wave velocity (hfPWV), were measured non-invasively. The clinical and angiographic characteristics of CAD patients were also evaluated. Associations between anti-elastin levels and vascular characteristics were examined by linear regression analysis. Results The median blood level of anti-elastin was significantly lower in the CAD group than in the controls [197 arbitrary unit (a.u.) vs. 63 a.u., p<0.001]. Levels of anti-elastin were significantly lower in men and in subjects with hypertension, diabetes mellitus, hyperlipidemia, or high hfPWV. Nevertheless, anti-elastin levels were not dependent on atherothrombotic events or the angiographic severity of CAD. In a multivariate analysis, male sex (β=-0.38, p<0.001), diabetes mellitus (β=-0.62, p<0.001), hyperlipidemia (β=-0.29, p<0.001), and AI (β=-0.006, p=0.02) were ultimately identified as determinants of anti-elastin levels. Conclusion Lower levels of anti-elastin are related to CAD. The association between antibody titers and CAD is linked to arterial stiffness rather than the advancement of atherosclerosis. PMID:26446635

Transmural variation in elastin fiber orientation distribution in the arterial wall.

PubMed

Yu, Xunjie; Wang, Yunjie; Zhang, Yanhang

2018-01-01

The complex three-dimensional elastin network is a major load-bearing extracellular matrix (ECM) component of an artery. Despite the reported anisotropic behavior of arterial elastin network, it is usually treated as an isotropic material in constitutive models. Our recent multiphoton microscopy study reported a relatively uniform elastin fiber orientation distribution in porcine thoracic aorta when imaging from the intima side (Chow et al., 2014). However it is questionable whether the fiber orientation distribution obtained from a small depth is representative of the elastin network structure in the arterial wall, especially when developing structure-based constitutive models. To date, the structural basis for the anisotropic mechanical behavior of elastin is still not fully understood. In this study, we examined the transmural variation in elastin fiber orientation distribution in porcine thoracic aorta and its association with elastin anisotropy. Using multi-photon microscopy, we observed that the elastin fibers orientation changes from a relatively uniform distribution in regions close to the luminal surface to a more circumferential distribution in regions that dominate the media, then to a longitudinal distribution in regions close to the outer media. Planar biaxial tensile test was performed to characterize the anisotropic behavior of elastin network. A new structure-based constitutive model of elastin network was developed to incorporate the transmural variation in fiber orientation distribution. The new model well captures the anisotropic mechanical behavior of elastin network under both equi- and nonequi-biaxial loading and showed improvements in both fitting and predicting capabilities when compared to a model that only considers the fiber orientation distribution from the intima side. We submit that the transmural variation in fiber orientation distribution is important in characterizing the anisotropic mechanical behavior of elastin network and should be considered in constitutive modeling of an artery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular Mechanisms of Stress-Responsive Changes in Collagen and Elastin Networks in Skin.

PubMed

Aziz, Jazli; Shezali, Hafiz; Radzi, Zamri; Yahya, Noor Azlin; Abu Kassim, Noor Hayaty; Czernuszka, Jan; Rahman, Mohammad Tariqur

2016-01-01

Collagen and elastin networks make up the majority of the extracellular matrix in many organs, such as the skin. The mechanisms which are involved in the maintenance of homeostatic equilibrium of these networks are numerous, involving the regulation of genetic expression, growth factor secretion, signalling pathways, secondary messaging systems, and ion channel activity. However, many factors are capable of disrupting these pathways, which leads to an imbalance of homeostatic equilibrium. Ultimately, this leads to changes in the physical nature of skin, both functionally and cosmetically. Although various factors have been identified, including carcinogenesis, ultraviolet exposure, and mechanical stretching of skin, it was discovered that many of them affect similar components of regulatory pathways, such as fibroblasts, lysyl oxidase, and fibronectin. Additionally, it was discovered that the various regulatory pathways intersect with each other at various stages instead of working independently of each other. This review paper proposes a model which elucidates how these molecular pathways intersect with one another, and how various internal and external factors can disrupt these pathways, ultimately leading to a disruption in collagen and elastin networks. © 2016 S. Karger AG, Basel.

Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders.

PubMed

Kristensen, J H; Larsen, L; Dasgupta, B; Brodmerkel, C; Curran, M; Karsdal, M A; Sand, J M B; Willumsen, N; Knox, A J; Bolton, C E; Johnson, S R; Hägglund, P; Svensson, B; Leeming, D J

2015-11-01

Elastin is a signature protein of the lungs. Matrix metalloproteinase-7 (MMP-7) is important in lung defence mechanisms and degrades elastin. However, MMP-7 activity in regard to elastin degradation has never been quantified serologically in patients with lung diseases. An assay for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer. Monoclonal antibodies (mABs) were raised against eight carefully selected MMP-7 cleavage sites on elastin. After characterisation and validation of the mABs, one mAB targeting the ELM7 fragment was chosen. ELM7 fragment levels were assessed in serum samples from patients diagnosed with IPF (n=123, baseline samples, CTgov reg. NCT00786201), and lung cancer (n=40) and compared with age- and sex-matched controls. The ELM7 assay was specific towards in vitro MMP-7 degraded elastin and the ELM7 neoepitope but not towards other MMP-7 derived elastin fragments. Serum ELM7 levels were significantly increased in IPF (113%, p<0.0001) and lung cancer (96%, p<0.0001) compared to matched controls. MMP-7-generated elastin fragments can be quantified in serum and may reflect pathological lung tissue turnover in several important lung diseases. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Elastin Fiber Accumulation in Liver Correlates with the Development of Hepatocellular Carcinoma

PubMed Central

Kurosaki, Masayuki; Higuchi, Mayu; Komiyama, Yasuyuki; Yoshida, Tsubasa; Hayashi, Tsuguru; Kuwabara, Konomi; Takaura, Kenta; Nakakuki, Natsuko; Takada, Hitomi; Tamaki, Nobuharu; Suzuki, Shoko; Nakanishi, Hiroyuki; Tsuchiya, Kaoru; Itakura, Jun; Takahashi, Yuka; Hashiguchi, Akinori; Sakamoto, Michiie; Izumi, Namiki

2016-01-01

Background & Aims The fibrosis stage, which is evaluated by the distribution pattern of collagen fibers, is a major predictor for the development of hepatocellular carcinoma (HCC) for patients with hepatitis C. Meanwhile, the role of elastin fibers has not yet been elucidated. The present study was conducted to determine the significance of quantifying both collagen and elastin fibers. Methods We enrolled 189 consecutive patients with hepatitis C and advanced fibrosis. Using Elastica van Gieson-stained whole-slide images of pretreatment liver biopsies, collagen and elastin fibers were evaluated pixel by pixel (0.46 μm/pixel) using an automated computational method. Consequently, fiber amount and cumulative incidences of HCC within 3 years were analyzed. Results There was a significant correlation between collagen and elastin fibers, whereas variation in elastin fiber was greater than in collagen fiber. Both collagen fiber (p = 0.008) and elastin fiber (p < 0.001) were significantly correlated with F stage. In total, 30 patients developed HCC during follow-up. Patients who have higher elastin fiber (p = 0.002) in addition to higher collagen fiber (p = 0.05) showed significantly higher incidences of HCC. With regard to elastin fiber, this difference remained significant in F3 patients. Furthermore, for patients with a higher collagen fiber amount, higher elastin was a significant predictor for HCC development (p = 0.02). Conclusions Computational analysis is a novel technique for quantification of fibers with the added value of conventional staging. Elastin fiber is a predictor for the development of HCC independently of collagen fiber and F stage. PMID:27128435

Fluorescence, aggregation properties and FT-IR microspectroscopy of elastin and collagen fibers.

PubMed

Vidal, Benedicto de Campos

2014-10-01

Histological and histochemical observations support the hypothesis that collagen fibers can link to elastic fibers. However, the resulting organization of elastin and collagen type complexes and differences between these materials in terms of macromolecular orientation and frequencies of their chemical vibrational groups have not yet been solved. This study aimed to investigate the macromolecular organization of pure elastin, collagen type I and elastin-collagen complexes using polarized light DIC-microscopy. Additionally, differences and similarities between pure elastin and collagen bundles (CB) were investigated by Fourier transform-infrared (FT-IR) microspectroscopy. Although elastin exhibited a faint birefringence, the elastin-collagen complex aggregates formed in solution exhibited a deep birefringence and formation of an ordered-supramolecular complex typical of collagen chiral structure. The FT-IR study revealed elastin and CB peptide NH groups involved in different types of H-bonding. More energy is absorbed in the vibrational transitions corresponding to CH, CH2 and CH3 groups (probably associated with the hydrophobicity demonstrated by 8-anilino-1-naphtalene sulfonic acid sodium salt [ANS] fluorescence), and to νCN, δNH and ωCH2 groups of elastin compared to CB. It is assumed that the α-helix contribution to the pure elastin amide I profile is 46.8%, whereas that of the B-sheet is 20% and that unordered structures contribute to the remaining percentage. An FT-IR profile library reveals that the elastin signature within the 1360-1189cm(-1) spectral range resembles that of Conex-Toray aramid fibers. Copyright © 2014 Elsevier GmbH. All rights reserved.

Molecular-level insights into aging processes of skin elastin.

PubMed

Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang; Heyroth, Frank; Heinz, Andrea

2016-01-01

Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating the influence of intrinsic (chronological aging) and extrinsic factors (sun exposure) on the morphology and susceptibility of elastin towards enzymatic degradation. Elastin was isolated from biopsies derived from sun-protected or sun-exposed skin of differently aged individuals. The morphology of the elastin fibers was characterized by scanning electron microscopy. Mass spectrometric analysis and label-free quantification allowed identifying differences in the cleavage patterns of the elastin samples after enzymatic digestion. Principal component analysis and hierarchical cluster analysis were used to visualize differences between the samples and to determine the contribution of extrinsic and intrinsic aging to the proteolytic susceptibility of elastin. Moreover, the release of potentially bioactive peptides was studied. Skin aging is associated with the decomposition of elastin fibers, which is more pronounced in sun-exposed tissue. Marker peptides were identified, which showed an age-related increase or decrease in their abundances and provide insights into the progression of the aging process of elastin fibers. Strong age-related cleavage occurs in hydrophobic tropoelastin domains 18, 20, 24 and 26. Photoaging makes the N-terminal and central parts of the tropoelastin molecules more susceptible towards enzymatic cleavage and, hence, accelerates the age-related degradation of elastin. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Transcriptome analysis of skin fibroblasts with dominant negative COL3A1 mutations provides molecular insights into the etiopathology of vascular Ehlers-Danlos syndrome

PubMed Central

Chiarelli, Nicola; Carini, Giulia; Zoppi, Nicoletta; Ritelli, Marco

2018-01-01

Vascular Ehlers-Danlos syndrome (vEDS) is a dominantly inherited connective tissue disorder caused by mutations in the COL3A1 gene that encodes type III collagen (COLLIII), which is the major expressed collagen in blood vessels and hollow organs. The majority of disease-causing variants in COL3A1 are glycine substitutions and in-frame splice mutations in the triple helix domain that through a dominant negative effect are associated with the severe clinical spectrum potentially lethal of vEDS, characterized by fragility of soft connective tissues with arterial and organ ruptures. To shed lights into molecular mechanisms underlying vEDS, we performed gene expression profiling in cultured skin fibroblasts from three patients with different structural COL3A1 mutations. Transcriptome analysis revealed significant changes in the expression levels of several genes involved in maintenance of cell redox and endoplasmic reticulum (ER) homeostasis, COLLs folding and extracellular matrix (ECM) organization, formation of the proteasome complex, and cell cycle regulation. Protein analyses showed that aberrant COLLIII expression is associated with the disassembly of many structural ECM constituents, such as fibrillins, EMILINs, and elastin, as well as with the reduction of the proteoglycans perlecan, decorin, and versican, all playing an important role in the vascular system. Furthermore, the altered distribution of the ER marker protein disulfide isomerase PDI and the strong reduction of the COLLs-modifying enzyme FKBP22 are consistent with the disturbance of ER-related homeostasis and COLLs biosynthesis and post-translational modifications, indicated by microarray analysis. Our findings add new insights into the pathophysiology of this severe vascular disorder, since they provide a picture of the gene expression changes in vEDS skin fibroblasts and highlight that dominant negative mutations in COL3A1 also affect post-translational modifications and deposition into the ECM of several structural proteins crucial to the integrity of soft connective tissues. PMID:29346445

Transcriptome analysis of skin fibroblasts with dominant negative COL3A1 mutations provides molecular insights into the etiopathology of vascular Ehlers-Danlos syndrome.

PubMed

Chiarelli, Nicola; Carini, Giulia; Zoppi, Nicoletta; Ritelli, Marco; Colombi, Marina

2018-01-01

Vascular Ehlers-Danlos syndrome (vEDS) is a dominantly inherited connective tissue disorder caused by mutations in the COL3A1 gene that encodes type III collagen (COLLIII), which is the major expressed collagen in blood vessels and hollow organs. The majority of disease-causing variants in COL3A1 are glycine substitutions and in-frame splice mutations in the triple helix domain that through a dominant negative effect are associated with the severe clinical spectrum potentially lethal of vEDS, characterized by fragility of soft connective tissues with arterial and organ ruptures. To shed lights into molecular mechanisms underlying vEDS, we performed gene expression profiling in cultured skin fibroblasts from three patients with different structural COL3A1 mutations. Transcriptome analysis revealed significant changes in the expression levels of several genes involved in maintenance of cell redox and endoplasmic reticulum (ER) homeostasis, COLLs folding and extracellular matrix (ECM) organization, formation of the proteasome complex, and cell cycle regulation. Protein analyses showed that aberrant COLLIII expression is associated with the disassembly of many structural ECM constituents, such as fibrillins, EMILINs, and elastin, as well as with the reduction of the proteoglycans perlecan, decorin, and versican, all playing an important role in the vascular system. Furthermore, the altered distribution of the ER marker protein disulfide isomerase PDI and the strong reduction of the COLLs-modifying enzyme FKBP22 are consistent with the disturbance of ER-related homeostasis and COLLs biosynthesis and post-translational modifications, indicated by microarray analysis. Our findings add new insights into the pathophysiology of this severe vascular disorder, since they provide a picture of the gene expression changes in vEDS skin fibroblasts and highlight that dominant negative mutations in COL3A1 also affect post-translational modifications and deposition into the ECM of several structural proteins crucial to the integrity of soft connective tissues.

Glucose Suppresses Biological Ferroelectricity in Aortic Elastin

PubMed Central

Liu, Yuanming; Wang, Yunjie; Chow, Ming-Jay; Chen, Nataly Q.; Ma, Feiyue; Zhang, Yanhang; Li, Jiangyu

2013-01-01

Elastin is an intriguing extracellular matrix protein present in all connective tissues of vertebrates, rendering essential elasticity to connective tissues subjected to repeated physiological stresses. Using piezoresponse force microscopy, we show that the polarity of aortic elastin is switchable by an electrical field, which may be associated with the recently discovered biological ferroelectricity in the aorta. More interestingly, it is discovered that the switching in aortic elastin is largely suppressed by glucose treatment, which appears to freeze the internal asymmetric polar structures of elastin, making it much harder to switch, or suppressing the switching completely. Such loss of ferroelectricity could have important physiological and pathological implications from aging to arteriosclerosis that are closely related to glycation of elastin. PMID:23679639

ELASTIN: DIMINISHED REACTIVITY WITH ALDEHYDE REAGENTS IN COPPER DEFICIENCY AND LATHYRISM

PubMed Central

Miller, E. J.; Fullmer, Harold M.

1966-01-01

Elastin fibers in the aortas of control, lathyritic, copper-supplemented, and copper-deficient chicks were examined histochemically and chemically for aldehyde content. Diminished staining for aldehydes was obtained in the fibers from the aortas of lathyritic and copper-deficient chicks. Chemical studies of elastin isolated from the aortas of control and lathyritic chicks showed an apparent loss of lysine residues in control elastin to be associated with an increase in aldehyde content providing evidence that lysine is converted to an aldehyde-containing intermediate during biosynthesis of desmosine and isodesmosine. Approximately 6 aldehyde groups were present for every 1000 amino acids in elastin isolated from the aortas of control animals, while the corresponding number in lathyritic elastin was 4. At least two types of aldehydes, saturated and α,β-unsaturated, appear to be associated with elastin, suggesting the presence of more than one intermediate between lysine and the desmosines. PMID:5941783

Phase separation and mechanical properties of an elastomeric biomaterial from spider wrapping silk and elastin block copolymers.

PubMed

Muiznieks, Lisa D; Keeley, Fred W

2016-10-01

Elastin and silk spidroins are fibrous, structural proteins with elastomeric properties of extension and recoil. While elastin is highly extensible and has excellent recovery of elastic energy, silks are particularly strong and tough. This study describes the biophysical characterization of recombinant polypeptides designed by combining spider wrapping silk and elastin-like sequences as a strategy to rationally increase the strength of elastin-based materials while maintaining extensibility. We demonstrate a thermo-responsive phase separation and spontaneous colloid-like droplet formation from silk-elastin block copolymers, and from a 34 residue disordered region of Argiope trifasciata wrapping silk alone, and measure a comprehensive suite of tensile mechanical properties from cross-linked materials. Silk-elastin materials exhibited significantly increased strength, toughness, and stiffness compared to an elastin-only material, while retaining high failure strains and low energy loss upon recoil. These data demonstrate the mechanical tunability of protein polymer biomaterials through modular, chimeric recombination, and provide structural insights into mechanical design. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 693-703, 2016. © 2016 Wiley Periodicals, Inc.

Polyphenol-Stabilized Tubular Elastin Scaffolds for Tissue Engineered Vascular Grafts

PubMed Central

Chuang, Ting-Hsien; Stabler, Christopher; Simionescu, Agneta

2009-01-01

Tissue-engineered vascular grafts require elastic, acellular porous scaffolds with controlled biodegradability and properties matching those of natural arteries. Elastin would be a desirable component for such applications, but elastin does not easily regenerate experimentally. Our approach is to develop tubular elastin scaffolds using decellularization and removal of collagen from porcine carotid arteries (∼5 mm diameter) using alkaline extraction. Because elastin is susceptible to rapid degeneration after implantation, scaffolds were further treated with penta-galloyl glucose (PGG), an established polyphenolic elastin-stabilizing agent. Scaffolds were compared in vitro with detergent-decellularized arteries for structure, composition, resistance to degradation, mechanical properties, and cytotoxicity and in vivo for cell infiltration and remodeling potential. Results showed effective decellularization and almost complete collagen removal by alkaline extraction. PGG-treated elastin scaffolds proved to be resistant to elastase digestion in vitro, maintained their cylindrical shapes, showed high resistance to burst pressures, and supported growth of endothelial cells and fibroblasts. In vivo results showed that PGG treatment reduced the rate of elastin biodegradation and controlled cell infiltration but did not hamper new collagen and proteoglycan deposition and secretion of matrix-degrading proteases. Alkali-purified, PGG-treated tubular arterial elastin scaffolds exhibit many desirable properties to be recommended for clinical applications as vascular grafts. PMID:19254115

Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

PubMed

Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

2016-10-01

Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P < 0.05). Elastin-like polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

Prolyl hydroxylation in elastin is not random.

PubMed

Schmelzer, Christian E H; Nagel, Marcus B M; Dziomba, Szymon; Merkher, Yulia; Sivan, Sarit S; Heinz, Andrea

2016-10-01

This study aimed to investigate the prolyl and lysine hydroxylation in elastin from different species and tissues. Enzymatic digests of elastin samples from human, cattle, pig and chicken were analyzed using mass spectrometry and bioinformatics tools. It was confirmed at the protein level that elastin does not contain hydroxylated lysine residues regardless of the species. In contrast, prolyl hydroxylation sites were identified in all elastin samples. Moreover, the analysis of the residues adjacent to prolines allowed the determination of the substrate site preferences of prolyl 4-hydroxylase. It was found that elastins from all analyzed species contain hydroxyproline and that at least 20%-24% of all proline residues were partially hydroxylated. Determination of the hydroxylation degrees of specific proline residues revealed that prolyl hydroxylation depends on both the species and the tissue, however, is independent of age. The fact that the highest hydroxylation degrees of proline residues were found for elastin from the intervertebral disc and knowledge of elastin arrangement in this tissue suggest that hydroxylation plays a biomechanical role. Interestingly, a proline-rich domain of tropoelastin (domain 24), which contains several repeats of bioactive motifs, does not show any hydroxyproline residues in the mammals studied. The results show that prolyl hydroxylation is not a coincidental feature and may contribute to the adaptation of the properties of elastin to meet the functional requirements of different tissues. The study for the first time shows that prolyl hydroxylation is highly regulated in elastin. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of glucose on the biomechanical function of arterial elastin

PubMed Central

Wang, Yunjie; Zeinali-Davarani, Shahrokh; Davis, Elaine C.; Zhang, Yanhang

2015-01-01

Elastin is essential to provide elastic support for blood vessels. As a remarkably long-lived protein, elastin can suffer from cumulative effects of exposure to biochemical damages, which can greatly compromise its biomechanical properties. Non-enzymatic glycation is one of the main mechanisms of aging and its effect is magnified in diabetic patients. The purpose of this study is to investigate the effects of glucose on mechanical properties of isolated porcine aortic elastin. Elastin samples were incubated in 2 M glucose solution and were allowed to equilibrate for 4, 7, 14, 21 or 28 days at 37°C. Equibiaxial tensile tests were performed to study the changes of elastic properties of elastin due to glycation. Significant decreases in tissue dimension were observed after 7 days glucose incubation. Elastin samples treated for 14, 21 or 28 days demonstrate a significant increase in hysteresis in the stress-stretch curves, indicating a greater energy loss due to glucose treatment. Both the longitudinal and the circumferential directions show significant increases in tangent modulus with glucose treatment, however only significant increases are observed after 7 days for the circumferential direction. An eight-chain statistical mechanics based microstructural model was used to study the hyperelastic and orthotropic behavior of the glucose-treated elastin and the material parameters were estimated using a nonlinear least squares method. Material parameters in the model were related to elastin density and fiber orientation, and, hence, the possible microstructural changes in glucose-treated elastin. Estimated material parameters show a general increasing trend in elastin density per unit volume with glucose incubation. The simulation results also indicate that more elastic fibers are aligned in the longitudinal and circumferential directions, rather than in the radial direction. PMID:26042769

Effect of glucose on the biomechanical function of arterial elastin.

PubMed

Wang, Yunjie; Zeinali-Davarani, Shahrokh; Davis, Elaine C; Zhang, Yanhang

2015-09-01

Elastin is essential to provide elastic support for blood vessels. As a remarkably long-lived protein, elastin can suffer from cumulative effects of exposure to biochemical damages, which can greatly compromise its biomechanical properties. Non-enzymatic glycation is one of the main mechanisms of aging and its effect is magnified in diabetic patients. The purpose of this study is to investigate the effects of glucose on mechanical properties of isolated porcine aortic elastin. Elastin samples were incubated in 2 M glucose solution and were allowed to equilibrate for 4, 7, 14, 21 or 28 days at 37 °C. Equibiaxial tensile tests were performed to study the changes of elastic properties of elastin due to glycation. Significant decreases in tissue dimension were observed after 7 days glucose incubation. Elastin samples treated for 14, 21 or 28 days demonstrate a significant increase in hysteresis in the stress-stretch curves, indicating a greater energy loss due to glucose treatment. Both the longitudinal and the circumferential directions show significant increases in tangent modulus with glucose treatment, however only significant increases are observed after 7 days for the circumferential direction. An eight-chain statistical mechanics based microstructural model was used to study the hyperelastic and orthotropic behavior of the glucose-treated elastin and the material parameters were estimated using a nonlinear least squares method. Material parameters in the model were related to elastin density and fiber orientation, and, hence, the possible microstructural changes in glucose-treated elastin. Estimated material parameters show a general increasing trend in elastin density per unit volume with glucose incubation. The simulation results also indicate that more elastic fibers are aligned in the longitudinal and circumferential directions, rather than in the radial direction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecular cloning and sequencing of the cDNA and gene for a novel elastinolytic metalloproteinase from Aspergillus fumigatus and its expression in Escherichia coli.

PubMed Central

Sirakova, T D; Markaryan, A; Kolattukudy, P E

1994-01-01

An extracellular elastinolytic metalloproteinase, purified from Aspergillus fumigatus isolated from an aspergillosis and patient/and an internal peptide derived from it were subjected to N-terminal sequencing. Oligonucleotide primers based on these sequences were used to PCR amplify a segment of the metalloproteinase cDNA, which was used as a probe to isolate the cDNA and gene for this enzyme. The gene sequence matched exactly with the cDNA sequence except for the four introns that interrupted the open reading frame. According to the deduced amino acid sequence, the metalloproteinase has a signal sequence and 227 additional amino acids preceding the sequence for the mature protein of 389 amino acids with a calculated molecular mass of 42 kDa, which is close to the size of the purified mature fungal proteinase. This sequence contains segments that matched both the N terminus of the mature protein and the internal peptide. A. fumigatus metalloproteinase contains some of the conserved zinc-binding and active-site motifs characteristic of metalloproteinases but shows no overall homology with known metalloproteinases. The cDNA of the mature protein when introduced into Escherichia coli directed the expression of a protein with a size, N-terminal sequence, and immunological cross-reactivity identical to those of the native fungal enzyme. Although the enzyme in the inclusion bodies could not be renatured, expression at 30 degrees C yielded soluble enzyme that showed chromatographic behavior identical to that of the native fungal enzyme and catalyzed hydrolysis of elastin. The metalloproteinase gene described here was not found in Aspergillus flavus. Images PMID:7927676

Regulation of aortic extracellular matrix synthesis via noradrenergic system and angiotensin II in juvenile rats.

PubMed

Dab, Houcine; Hachani, Rafik; Dhaouadi, Nedra; Sakly, Mohsen; Hodroj, Wassim; Randon, Jacques; Bricca, Giampiero; Kacem, Kamel

2012-10-01

Extracellular matrix (ECM) synthesis regulation by sympathetic nervous system (SNS) or angiotensin II (ANG II) was widely reported, but interaction between the two systems on ECM synthesis needs further investigation. We tested implication of SNS and ANG II on ECM synthesis in juvenile rat aorta. Sympathectomy with guanethidine (50 mg/kg, subcutaneous) and blockade of the ANG II AT1 receptors (AT1R) blocker with losartan (20 mg/kg/day in drinking water) were performed alone or in combination in rats. mRNA and protein synthesis of collagen and elastin were examined by Q-RT-PCR and immunoblotting. Collagen type I and III mRNA were increased respectively by 62 and 43% after sympathectomy and decreased respectively by 31 and 60% after AT1R blockade. Combined treatment increased collagen type III by 36% but not collagen type I. The same tendency of collagen expression was observed at mRNA and protein levels after the three treatments. mRNA and protein level of elastin was decreased respectively by 63 and 39% and increased by 158 and 15% after losartan treatment. Combined treatment abrogates changes induced by single treatments. The two systems act as antagonists on ECM expression in the aorta and combined inhibition of the two systems prevents imbalance of mRNA and protein level of collagen I and elastin induced by single treatment. Combined inhibition of the two systems prevents deposit or excessive reduction of ECM and can more prevent cardiovascular disorders.

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus.

PubMed

Price, Daniel L; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G; Yu, Yong A; Szalay, Aladar A; Cappello, Joseph; Fong, Yuman; Wong, Richard J

2016-02-01

Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. © 2014 Wiley Periodicals, Inc.

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus

PubMed Central

Price, Daniel L.; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G.; Yu, Yong A.; Szalay, Aladar A.; Cappello, Joseph; Fong, Yuman; Wong, Richard J.

2016-01-01

Background Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Methods Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. Results GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. Conclusion The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. PMID:25244076

Self-assembly of silk-elastinlike protein polymers into three-dimensional scaffolds for biomedical applications

NASA Astrophysics Data System (ADS)

Zeng, Like

Production of brand new protein-based materials with precise control over the amino acid sequences at single residue level has been made possible by genetic engineering, through which artificial genes can be developed that encode protein-based materials with desired features. As an example, silk-elastinlike protein polymers (SELPs), composed of tandem repeats of amino acid sequence motifs from Bombyx mori (silkworm) silk and mammalian elastin, have been produced in this approach. SELPs have been studied extensively in the past two decades, however, the fundamental mechanism governing the self-assembly process to date still remains largely unresolved. Further, regardless of the unprecedented success when exploited in areas including drug delivery, gene therapy, and tissue augmentation, SELPs scaffolds as a three-dimensional cell culture model system are complicated by the inability of SELPs to provide the embedded tissue cells with appropriate biochemical stimuli essential for cell survival and function. In this dissertation, it is reported that the self-assembly of silk-elastinlike protein polymers (SELPs) into nanofibers in aqueous solutions can be modulated by tuning the curing temperature, the size of the silk blocks, and the charge of the elastin blocks. A core-sheath model was proposed for nanofiber formation, with the silk blocks in the cores and the hydrated elastin blocks in the sheaths. The folding of the silk blocks into stable cores -- affected by the size of the silk blocks and the charge of the elastin blocks -- plays a critical role in the assembly of silk-elastin nanofibers. The assembled nanofibers further form nanofiber clusters on the microscale, and the nanofiber clusters then coalesce into nanofiber micro-assemblies, interconnection of which eventually leads to the formation of three-dimensional scaffolds with distinct nanoscale and microscale features. SELP-Collagen hybrid scaffolds were also fabricated to enable independent control over the scaffolds' biochemical input and matrix stiffness. It is reported herein that in the hybrid scaffolds, collagen provides essential biochemical cues needed to promote cell attachment and function while SELP imparts matrix stiffness tunability. To obtain tissue-specificity in matrix stiffness that spans over several orders of magnitude covering from soft brain to stiff cartilage, the hybrid SELP-Collagen scaffolds were crosslinked by transglutaminase at physiological conditions compatible for simultaneous cell encapsulation. The effect of the increase in matrix stiffness induced by such enzymatic crosslinking on cellular viability and proliferation was also evaluated using in vitro cell assays.

Elastin-like Protein-Hyaluronic acid (ELP-HA) Hydrogels with Decoupled Mechanical and Biochemical cues for Cartilage Regeneration

PubMed Central

Zhu, Danqing; Wang, Huiyuan; Trinh, Pavin; Heilshorn, Sarah C.; Yang, Fan

2018-01-01

Hyaluronic acid (HA) is a major component of cartilage extracellular matrix and is an attractive material for use as 3D injectable matrices for cartilage regeneration. While previous studies have shown the promise of HA-based hydrogels to support cell-based cartilage formation, varying HA concentration generally led to simultaneous changes in both biochemical cues and stiffness. How cells respond to the change of biochemical content of HA remains largely unknown. Here we report an adaptable elastin-like protein-hyaluronic acid (ELP-HA) hydrogel platform using dynamic covalent chemistry, which allows varyiation of HA concentration without affecting matrix stiffness. ELP-HA hydrogels were created through dynamic hydrazone bonds via the reaction between hydrazine-modified ELP (ELP-HYD) and aldehyde-modified HA (HA-ALD). By tuning the stoichiometric ratio of aldehyde groups to hydrazine groups while maintaining ELP-HYD concentration constant, hydrogels with variable HA concentration (1.5%, 3%, or 5%) (w/v) were fabricated with comparable stiffness. To evaluate the effects of HA concentration on cell-based cartilage regeneration, chondrocytes were encapsulated within ELP-HA hydrogels with varying HA concentration. Increasing HA concentration led to a dose-dependent increase in cartilage-marker gene expression and enhanced sGAG deposition while minimizing undesirable fibrocartilage phenotype. The use of adaptable protein hydrogels formed via dynamic covalent chemistry may be broadly applicable as 3D scaffolds with decoupled niche properties to guide other desirable cell fates and tissue repair. PMID:28268018

Elastin-like protein-hyaluronic acid (ELP-HA) hydrogels with decoupled mechanical and biochemical cues for cartilage regeneration.

PubMed

Zhu, Danqing; Wang, Huiyuan; Trinh, Pavin; Heilshorn, Sarah C; Yang, Fan

2017-05-01

Hyaluronic acid (HA) is a major component of cartilage extracellular matrix and is an attractive material for use as 3D injectable matrices for cartilage regeneration. While previous studies have shown the promise of HA-based hydrogels to support cell-based cartilage formation, varying HA concentration generally led to simultaneous changes in both biochemical cues and stiffness. How cells respond to the change of biochemical content of HA remains largely unknown. Here we report an adaptable elastin-like protein-hyaluronic acid (ELP-HA) hydrogel platform using dynamic covalent chemistry, which allows variation of HA concentration without affecting matrix stiffness. ELP-HA hydrogels were created through dynamic hydrazone bonds via the reaction between hydrazine-modified ELP (ELP-HYD) and aldehyde-modified HA (HA-ALD). By tuning the stoichiometric ratio of aldehyde groups to hydrazine groups while maintaining ELP-HYD concentration constant, hydrogels with variable HA concentration (1.5%, 3%, or 5%) (w/v) were fabricated with comparable stiffness. To evaluate the effects of HA concentration on cell-based cartilage regeneration, chondrocytes were encapsulated within ELP-HA hydrogels with varying HA concentration. Increasing HA concentration led to a dose-dependent increase in cartilage-marker gene expression and enhanced sGAG deposition while minimizing undesirable fibrocartilage phenotype. The use of adaptable protein hydrogels formed via dynamic covalent chemistry may be broadly applicable as 3D scaffolds with decoupled niche properties to guide other desirable cell fates and tissue repair. Copyright © 2017 Elsevier Ltd. All rights reserved.

Elastin governs the mechanical response of medial collateral ligament under shear and transverse tensile loading.

PubMed

Henninger, Heath B; Valdez, William R; Scott, Sara A; Weiss, Jeffrey A

2015-10-01

Elastin is a highly extensible structural protein network that provides near-elastic resistance to deformation in biological tissues. In ligament, elastin is localized between and along the collagen fibers and fascicles. When ligament is stretched along the primary collagen axis, elastin supports a relatively high percentage of load. We hypothesized that elastin may also provide significant load support under elongation transverse to the primary collagen axis and shear along the collagen axis. Quasi-static transverse tensile and shear material tests were performed to quantify the mechanical contributions of elastin during deformation of porcine medial collateral ligament. Dose response studies were conducted to determine the level of elastase enzymatic degradation required to produce a maximal change in the mechanical response. Maximal changes in peak stress occurred after 3h of treatment with 2U/ml porcine pancreatic elastase. Elastin degradation resulted in a 60-70% reduction in peak stress and a 2-3× reduction in modulus for both test protocols. These results demonstrate that elastin provides significant resistance to elongation transverse to the collagen axis and shear along the collagen axis while only constituting 4% of the tissue dry weight. The magnitudes of the elastin contribution to peak transverse and shear stress were approximately 0.03 MPa, as compared to 2 MPa for axial tensile tests, suggesting that elastin provides a highly anisotropic contribution to the mechanical response of ligament and is the dominant structural protein resisting transverse and shear deformation of the tissue. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The influence of angiotensin-converting enzyme inhibitors on the aorta elastin metabolism in diet-induced hypercholesterolaemia in rabbits.

PubMed

Wojakowski, W; Gminski, J; Siemianowicz, K; Goss, M; Machalski, M

2001-03-01

Aortic elastin turnover is significantly accelerated in atherosclerosis, partly because of activation of the renin-angiotensin-aldosterone system caused by hypercholesterolaemia. We postulated that angiotensin-converting enzyme inhibitors (ACE-I) prevent the aortic elastin loss in experimental hypercholesterolaemia. Two doses of ACE-I (captopril, enalapril and quinapril) were used: a dose equivalent to that applied to human subjects and a dose 10 times higher. We found that the increase in serum and aortic elastolytic activity in cholesterol-fed rabbits was prevented by high-dose captopril. The elastin content in aorta homogenates from cholesterol-fed rabbits was significantly decreased. The higher dose of captopril, but no other ACE-I, prevented this decrease in aortic elastin content. In cholesterol-fed rabbits the elastin-bound calcium content was significantly elevated. The higher doses of captopril and enalapril lowered the elastin-bound calcium content. In serum and aortic homogenates of cholesterol-fed rabbits, ACE activity was elevated by 15% and 77%, respectively. Both doses of captopril, enalapril and quinapril prevented this cholesterol-induced increase in serum and aortic ACE activity. We conclude that: 1) administration of captopril at doses 10 times higher than those used in humans prevents hypercholesterolaemia increased aortic elastin loss. 2) higher doses of captopril and enalapril prevent the hypercholesterolaemia-induced increase in aortic elastin-bound calcium.

Effect of Elastin Digestion on the Quasi-static Tensile Response of Medial Collateral Ligament

PubMed Central

Henninger, Heath B.; Underwood, Clayton J.; Romney, Steven J.; Davis, Grant L.; Weiss, Jeffrey A.

2014-01-01

Elastin is a structural protein that provides resilience to biological tissues. We examined the contributions of elastin to the quasi-static tensile response of porcine medial collateral ligament through targeted disruption of the elastin network with pancreatic elastase. Elastase concentration and treatment time were varied to determine a dose response. Whereas elastin content decreased with increasing elastase concentration and treatment time, the change in peak stress after cyclic loading reached a plateau above 1 U/ml elastase and 6 hr treatment. For specimens treated with 2 U/ml elastase for 6 hr, elastin content decreased approximately 35%. Mean peak tissue strain after cyclic loading (4.8%, p≥0.300), modulus (275 MPa, p≥0.114) and hysteresis (20%, p≥0.553) were unaffected by elastase digestion, but stress decreased significantly after treatment (up to 2 MPa, p≤0.049). Elastin degradation had no effect on failure properties, but tissue lengthened under the same pre-stress. Stiffness in the linear region was unaffected by elastase digestion, suggesting that enzyme treatment did not disrupt collagen. These results demonstrate that elastin primarily functions in the toe region of the stress-strain curve, yet contributes load support in the linear region. The increase in length after elastase digestion suggests that elastin may pre-stress and stabilize collagen crimp in ligaments. PMID:23553827

Neutrophil elastase-induced elastin degradation mediates macrophage influx and lung injury in 60% O2-exposed neonatal rats.

PubMed

Masood, Azhar; Yi, Man; Belcastro, Rosetta; Li, Jun; Lopez, Lianet; Kantores, Crystal; Jankov, Robert P; Tanswell, A Keith

2015-07-01

Neutrophil (PMNL) influx precedes lung macrophage (LM) influx into the lung following exposure of newborn pups to 60% O2. We hypothesized that PMNL were responsible for the signals leading to LM influx. This was confirmed when inhibition of PMNL influx with a CXC chemokine receptor-2 antagonist, SB-265610, also prevented the 60% O2-dependent LM influx, LM-derived nitrotyrosine formation, and pruning of small arterioles. Exposure to 60% O2 was associated with increased lung contents of neutrophil elastase and α-elastin, a marker of denatured elastin, and a decrease in elastin fiber density. This led us to speculate that neutrophil elastase-induced elastin fragments were the chemokines that led to a LM influx into the 60% O2-exposed lung. Inhibition of neutrophil elastase with sivelestat or elafin attenuated the LM influx. Sivelestat also attenuated the 60% O2-induced decrease in elastin fiber density. Daily injections of pups with an antibody to α-elastin prevented the 60% O2-dependent LM influx, impaired alveologenesis, and impaired small vessel formation. This suggests that neutrophil elastase inhibitors may protect against neonatal lung injury not only by preventing structural elastin degradation, but also by blocking elastin fragment-induced LM influx, thus preventing tissue injury from LM-derived peroxynitrite formation. Copyright © 2015 the American Physiological Society.

Prevalence of scoliosis in Williams-Beuren syndrome patients treated at a regional reference center

PubMed Central

Damasceno, Marcelo Loquette; Cristante, Alexandre Fogaça; Marcon, Raphael Martus; de Barros Filho, Tarcísio Eloy Pessoa

2014-01-01

OBJECTIVE: This study assessed the prevalence of scoliosis and the patterns of scoliotic curves in patients with Williams-Beuren syndrome. Williams-Beuren syndrome is caused by a chromosome 7q11.23 deletion in a region containing 28 genes, with the gene encoding elastin situated approximately at the midpoint of the deletion. Mutation of the elastin gene leads to phenotypic changes in patients, including neurodevelopmental impairment of varying degrees, characteristic facies, cardiovascular abnormalities, hypercalcemia, urological dysfunctions, and bone and joint dysfunctions. METHODS: A total of 41 patients diagnosed with Williams-Beuren syndrome, who were followed up at the genetics ambulatory center of a large referral hospital, were included in the study. There were 25 male subjects. The patients were examined and submitted to radiographic investigation for Cobb angle calculation. RESULTS: It was observed that 14 patients had scoliosis; of these 14 patients, 10 were male. The pattern of deformity in younger patients was that of flexible and simple curves, although adults presented with double and triple curves. Statistical analysis showed no relationships between scoliosis and age or sex. CONCLUSION: This study revealed a prevalence of scoliosis in patients with Williams-Beuren syndrome of 34.1%; however, age and sex were not significantly associated with scoliosis or with the severity of the curves. PMID:25029575

Collagen and elastin cross-linking is altered during aberrant late lung development associated with hyperoxia.

PubMed

Mižíková, Ivana; Ruiz-Camp, Jordi; Steenbock, Heiko; Madurga, Alicia; Vadász, István; Herold, Susanne; Mayer, Konstantin; Seeger, Werner; Brinckmann, Jürgen; Morty, Rory E

2015-06-01

Maturation of the lung extracellular matrix (ECM) plays an important role in the formation of alveolar gas exchange units. A key step in ECM maturation is cross-linking of collagen and elastin, which imparts stability and functionality to the ECM. During aberrant late lung development in bronchopulmonary dysplasia (BPD) patients and animal models of BPD, alveolarization is blocked, and the function of ECM cross-linking enzymes is deregulated, suggesting that perturbed ECM cross-linking may impact alveolarization. In a hyperoxia (85% O2)-based mouse model of BPD, blunted alveolarization was accompanied by alterations to lung collagen and elastin levels and cross-linking. Total collagen levels were increased (by 63%). The abundance of dihydroxylysinonorleucine collagen cross-links and the dihydroxylysinonorleucine-to-hydroxylysinonorleucine ratio were increased by 11 and 18%, respectively, suggestive of a profibrotic state. In contrast, insoluble elastin levels and the abundance of the elastin cross-links desmosine and isodesmosine in insoluble elastin were decreased by 35, 30, and 21%, respectively. The lung collagen-to-elastin ratio was threefold increased. Treatment of hyperoxia-exposed newborn mice with the lysyl oxidase inhibitor β-aminopropionitrile partially restored normal collagen levels, normalized the dihydroxylysinonorleucine-to-hydroxylysinonorleucine ratio, partially normalized desmosine and isodesmosine cross-links in insoluble elastin, and partially restored elastin foci structure in the developing septa. However, β-aminopropionitrile administration concomitant with hyperoxia exposure did not improve alveolarization, evident from unchanged alveolar surface area and alveoli number, and worsened septal thickening (increased by 12%). These data demonstrate that collagen and elastin cross-linking are perturbed during the arrested alveolarization of developing mouse lungs exposed to hyperoxia. Copyright © 2015 the American Physiological Society.

In vitro cross-linking of elastin peptides and molecular characterization of the resultant biomaterials.

PubMed

Heinz, Andrea; Ruttkies, Christoph K H; Jahreis, Günther; Schräder, Christoph U; Wichapong, Kanin; Sippl, Wolfgang; Keeley, Fred W; Neubert, Reinhard H H; Schmelzer, Christian E H

2013-04-01

Elastin is a vital protein and the major component of elastic fibers which provides resilience to many vertebrate tissues. Elastin's structure and function are influenced by extensive cross-linking, however, the cross-linking pattern is still unknown. Small peptides containing reactive allysine residues based on sequences of cross-linking domains of human elastin were incubated in vitro to form cross-links characteristic of mature elastin. The resultant insoluble polymeric biomaterials were studied by scanning electron microscopy. Both, the supernatants of the samples and the insoluble polymers, after digestion with pancreatic elastase or trypsin, were furthermore comprehensively characterized on the molecular level using MALDI-TOF/TOF mass spectrometry. MS(2) data was used to develop the software PolyLinX, which is able to sequence not only linear and bifunctionally cross-linked peptides, but for the first time also tri- and tetrafunctionally cross-linked species. Thus, it was possible to identify intra- and intermolecular cross-links including allysine aldols, dehydrolysinonorleucines and dehydromerodesmosines. The formation of the tetrafunctional cross-link desmosine or isodesmosine was unexpected, however, could be confirmed by tandem mass spectrometry and molecular dynamics simulations. The study demonstrated that it is possible to produce biopolymers containing polyfunctional cross-links characteristic of mature elastin from small elastin peptides. MALDI-TOF/TOF mass spectrometry and the newly developed software PolyLinX proved suitable for sequencing of native cross-links in proteolytic digests of elastin-like biomaterials. The study provides important insight into the formation of native elastin cross-links and represents a considerable step towards the characterization of the complex cross-linking pattern of mature elastin. Copyright © 2013 Elsevier B.V. All rights reserved.

Dimerization effects on coacervation property of an elastin-derived synthetic peptide (FPGVG)5.

PubMed

Suyama, Keitaro; Taniguchi, Suguru; Tatsubo, Daiki; Maeda, Iori; Nose, Takeru

2016-04-01

Elastin, a core protein of the elastic fibers, exhibits the coacervation (temperature-dependent reversible association/dissociation) under physiological conditions. Because of this characteristic, elastin and elastin-derived peptides have been considered to be useful as base materials for developing various biomedical products, skin substitutes, synthetic vascular grafts, and drug delivery systems. Although elastin-derived polypeptide (Val-Pro-Gly-Val-Gly)n also has been known to demonstrate coacervation property, a sufficiently high (VPGVG)n repetition number (n>40) is required for coacervation. In the present study, a series of elastin-derived peptide (Phe-Pro-Gly-Val-Gly)5 dimers possessing high coacervation potential were newly developed. These novel dimeric peptides exhibited coacervation at significantly lower concentrations and temperatures than the commonly used elastin-derived peptide analogs; this result suggests that the coacervation ability of the peptides is enhanced by dimerization. Circular dichroism (CD) measurements indicate that the dimers undergo similar temperature-dependent and reversible conformational changes when coacervation occurs. The molecular dynamics calculation results reveal that the sheet-turn-sheet motif involving a type II β-turn-like structure commonly observed among the dimers and caused formation of globular conformation of them. These synthesized peptide dimers may be useful not only as model peptides for structural analysis of elastin and elastin-derived peptides, but also as base materials for developing various temperature-sensitive biomedical and industrial products. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

A wrinkle in flight: the role of elastin fibres in the mechanical behaviour of bat wing membranes

PubMed Central

Cheney, Jorn A.; Konow, Nicolai; Bearnot, Andrew; Swartz, Sharon M.

2015-01-01

Bats fly using a thin wing membrane composed of compliant, anisotropic skin. Wing membrane skin deforms dramatically as bats fly, and its three-dimensional configurations depend, in large part, on the mechanical behaviour of the tissue. Large, macroscopic elastin fibres are an unusual mechanical element found in the skin of bat wings. We characterize the fibre orientation and demonstrate that elastin fibres are responsible for the distinctive wrinkles in the surrounding membrane matrix. Uniaxial mechanical testing of the wing membrane, both parallel and perpendicular to elastin fibres, is used to distinguish the contribution of elastin and the surrounding matrix to the overall membrane mechanical behaviour. We find that the matrix is isotropic within the plane of the membrane and responsible for bearing load at high stress; elastin fibres are responsible for membrane anisotropy and only contribute substantially to load bearing at very low stress. The architecture of elastin fibres provides the extreme extensibility and self-folding/self-packing of the wing membrane skin. We relate these findings to flight with membrane wings and discuss the aeromechanical significance of elastin fibre pre-stress, membrane excess length, and how these parameters may aid bats in resisting gusts and preventing membrane flutter. PMID:25833238

A wrinkle in flight: the role of elastin fibres in the mechanical behaviour of bat wing membranes.

PubMed

Cheney, Jorn A; Konow, Nicolai; Bearnot, Andrew; Swartz, Sharon M

2015-05-06

Bats fly using a thin wing membrane composed of compliant, anisotropic skin. Wing membrane skin deforms dramatically as bats fly, and its three-dimensional configurations depend, in large part, on the mechanical behaviour of the tissue. Large, macroscopic elastin fibres are an unusual mechanical element found in the skin of bat wings. We characterize the fibre orientation and demonstrate that elastin fibres are responsible for the distinctive wrinkles in the surrounding membrane matrix. Uniaxial mechanical testing of the wing membrane, both parallel and perpendicular to elastin fibres, is used to distinguish the contribution of elastin and the surrounding matrix to the overall membrane mechanical behaviour. We find that the matrix is isotropic within the plane of the membrane and responsible for bearing load at high stress; elastin fibres are responsible for membrane anisotropy and only contribute substantially to load bearing at very low stress. The architecture of elastin fibres provides the extreme extensibility and self-folding/self-packing of the wing membrane skin. We relate these findings to flight with membrane wings and discuss the aeromechanical significance of elastin fibre pre-stress, membrane excess length, and how these parameters may aid bats in resisting gusts and preventing membrane flutter. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering.

PubMed

Palumbo, Fabio Salvatore; Pitarresi, Giovanna; Fiorica, Calogero; Rigogliuso, Salvatrice; Ghersi, Giulio; Giammona, Gaetano

2013-07-01

In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. The presence of α-elastin grafted to HA-EDA improves attachment, viability and proliferation of primary rat dermal fibroblasts and human umbilical artery smooth muscle cells. Biological performance of HA-EDA-g-α-elastin/EGDGE scaffold resulted comparable to that of a commercial collagen type I sponge (Antema®), chosen as a positive control. Copyright © 2013 Elsevier B.V. All rights reserved.

Fetal development of the elastic-fiber-mediated enthesis in the human middle ear.

PubMed

Takanashi, Yoshitaka; Shibata, Shunichi; Katori, Yukio; Murakami, Gen; Abe, Shinichi; Rodríguez-Vázquez, Jose Francisco; Kawase, Tetsuaki

2013-10-01

In the human middle ear, the annular ligament of the incudostapedial joint and the insertions of the tensor tympani and stapedius muscles contain abundant elastic fibers; i.e., the elastic-fiber-mediated entheses. Hyaluronan also coexists with the elastic fibers. In the present study using immunohistochemistry, we demonstrated the distribution of elastin not only in the incudostapedial joint but also in the other two joints of the middle ear in adults and fetuses. In adults, the expression of elastin did not extend out of the annular ligament composed of mature elastic fibers but clearly overlapped with it. Electron microscopic observations of the annular ligament demonstrated a few microfibrils along the elastic fibers. Thus, in contrast to the vocal cord, the middle ear entheses seemed not to contain elaunin and oxytalan fibers. In mid-term fetuses (at approximately 15-16 weeks of gestation) before opening of the external acoustic meatus, the incudostapedial joint showed abundant elastic fibers, but the incudomalleolar and stapediovestibular joints did not. At this stage, hyaluronan was not colocalized, but distributed diffusely in loose mesenchymal tissues surrounding the ear ossicles. Therefore, fetal development of elastin and elastic fibers in the middle ear entheses is unlikely to require acoustic oscillation. In late-stage fetuses (25-30 weeks), whose ear ossicles were almost the same size as those in adults, we observed bundling and branching of elastic fibers. However, hyaluronan expression was not as strong as in adults. Colocalization between elastic fibers and hyaluronan appeared to be a result of postnatal maturation of the entheses. Copyright © 2013 Elsevier GmbH. All rights reserved.

Loss of fibulin-4 disrupts collagen synthesis and maturation: implications for pathology resulting from EFEMP2 mutations

PubMed Central

Papke, Christina L.; Tsunezumi, Jun; Ringuette, Léa-Jeanne; Nagaoka, Hideaki; Terajima, Masahiko; Yamashiro, Yoshito; Urquhart, Greg; Yamauchi, Mitsuo; Davis, Elaine C.; Yanagisawa, Hiromi

2015-01-01

Homozygous recessive mutations in either EFEMP2 (encoding fibulin-4) or FBLN5 (encoding fibulin-5), critical genes for elastogenesis, lead to autosomal recessive cutis laxa types 1B and 1A, respectively. Previously, fibulin-4 was shown to bind lysyl oxidase (LOX), an elastin/collagen cross-linking enzyme, in vitro. Consistently, reported defects in humans with EFEMP2 mutations are more severe and broad in range than those due to FBLN5 mutations and encompass both elastin-rich and collagen-rich tissues. However, the underlying disease mechanism in EFEMP2 mutations has not been fully addressed. Here, we show that fibulin-4 is important for the integrity of aortic collagen in addition to elastin. Smooth muscle-specific Efemp2 loss in mouse (termed SMKO) resulted in altered fibrillar collagen localization with larger, poorly organized fibrils. LOX activity was decreased in Efemp2-null cells, and collagen cross-linking was diminished in SMKO aortas; however, elastin cross-linking was unaffected and the level of mature LOX was maintained to that of wild-type aortas. Proteomic screening identified multiple proteins involved in procollagen processing and maturation as potential fibulin-4-binding partners. We showed that fibulin-4 binds procollagen C-endopeptidase enhancer 1 (Pcolce), which enhances proteolytic cleavage of the procollagen C-terminal propeptide during procollagen processing. Interestingly, however, procollagen cleavage was not affected by the presence or absence of fibulin-4 in vitro. Thus, our data indicate that fibulin-4 serves as a potential scaffolding protein during collagen maturation in the extracellular space. Analysis of collagen in other tissues affected by fibulin-4 loss should further increase our understanding of underlying pathologic mechanisms in patients with EFEMP2 mutations. PMID:26220971

Multiphoton microscopy observations of 3D elastin and collagen fiber microstructure changes during pressurization in aortic media.

PubMed

Sugita, Shukei; Matsumoto, Takeo

2017-06-01

Elastin and collagen fibers play important roles in the mechanical properties of aortic media. Because knowledge of local fiber structures is required for detailed analysis of blood vessel wall mechanics, we investigated 3D microstructures of elastin and collagen fibers in thoracic aortas and monitored changes during pressurization. Using multiphoton microscopy, autofluorescence images from elastin and second harmonic generation signals from collagen were acquired in media from rabbit thoracic aortas that were stretched biaxially to restore physiological dimensions. Both elastin and collagen fibers were observed in all longitudinal-circumferential plane images, whereas alternate bright and dark layers were observed along the radial direction and were recognized as elastic laminas (ELs) and smooth muscle-rich layers (SMLs), respectively. Elastin and collagen fibers are mainly oriented in the circumferential direction, and waviness of collagen fibers was significantly higher than that of elastin fibers. Collagen fibers were more undulated in longitudinal than in radial direction, whereas undulation of elastin fibers was equibiaxial. Changes in waviness of collagen fibers during pressurization were then evaluated using 2-dimensional fast Fourier transform in mouse aortas, and indices of waviness of collagen fibers decreased with increases in intraluminal pressure. These indices also showed that collagen fibers in SMLs became straight at lower intraluminal pressures than those in EL, indicating that SMLs stretched more than ELs. These results indicate that deformation of the aorta due to pressurization is complicated because of the heterogeneity of tissue layers and differences in elastic properties of ELs, SMLs, and surrounding collagen and elastin.

Retained structural integrity of collagen and elastin within cryopreserved human heart valve tissue as detected by two-photon laser scanning confocal microscopy.

PubMed

Gerson, Cindy J; Goldstein, Steven; Heacox, Albert E

2009-10-01

Cryopreservation is commonly used for the long-term storage of heart valve allografts. Despite the excellent hemodynamic performance and durability of cryopreserved allografts, reports have questioned whether cryopreservation affects the valvular structural proteins, collagen and elastin. This study uses two-photon laser scanning confocal microscopy (LSCM) to evaluate the effect of cryopreservation on collagen and elastin integrity within the leaflet and conduit of aortic and pulmonary human heart valves. To permit pairwise comparisons of fresh and cryopreserved tissue, test valves were bisected longitudinally with one segment imaged fresh and the other imaged after cryopreservation and brief storage in liquid nitrogen. Collagen was detected by second harmonic generation (SHG) stimulation and elastin by autofluorescence excitation. Qualitative analysis of all resultant images indicated the maintenance of collagen and elastin structure within leaflet and conduit post-cryopreservation. Analysis of the optimized percent laser transmission (OPLT) required for full dynamic range imaging of collagen and elastin showed that OPLT observations were highly variable among both fresh and cryopreserved samples. Changes in donor-specific average OPLT in response to cryopreservation exhibited no consistent directional trend. The donor-aggregated results predominantly showed no statistically significant change in collagen and elastin average OPLT due to cryopreservation. Since OPLT has an inverse relationship with structural signal intensity, these results indicate that there was largely no statistical difference in collagen and elastin signal strength between fresh and cryopreserved tissue. Overall, this study indicates that the conventional cryopreservation of human heart valve allografts does not detrimentally affect their collagen and elastin structural integrity.

Production of novel biopolymers in plants: recent technological advances and future prospects.

PubMed

Snell, Kristi D; Singh, Vijay; Brumbley, Stevens M

2015-04-01

The production of novel biopolymers in plants has the potential to provide renewable sources of industrial materials through agriculture. In this review we will highlight recent progress with plant-based production of polyhydroxyalkanoates (PHAs), silk, elastin, collagen, and cyanophycin with an emphasis on the synthesis of poly[(R)-3-hydroxybutyrate] (PHB), a renewable biodegradable PHA polymer with potential commercial applications in plastics, chemicals, and feed markets. Improved production of PHB has required manipulation of promoters driving expression of transgenes, reduction in activity of endogenous enzymes in competing metabolic pathways, insertion of genes to increase carbon flow to polymer, and basic plant biochemistry to understand metabolic limitations. These experiments have increased our understanding of carbon availability and partitioning in different plant organelles, cell types, and organs, information that is useful for the production of other novel molecules in plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Discrete microstructural cues for the attenuation of fibrosis following myocardial infarction.

PubMed

Pinney, James R; Du, Kim T; Ayala, Perla; Fang, Qizhi; Sievers, Richard E; Chew, Patrick; Delrosario, Lawrence; Lee, Randall J; Desai, Tejal A

2014-10-01

Chronic fibrosis caused by acute myocardial infarction (MI) leads to increased morbidity and mortality due to cardiac dysfunction. We have developed a therapeutic materials strategy that aims to mitigate myocardial fibrosis by utilizing injectable polymeric microstructures to mechanically alter the microenvironment. Polymeric microstructures were fabricated using photolithographic techniques and studied in a three-dimensional culture model of the fibrotic environment and by direct injection into the infarct zone of adult rats. Here, we show dose-dependent down-regulation of expression of genes associated with the mechanical fibrotic response in the presence of microstructures. Injection of this microstructured material into the infarct zone decreased levels of collagen and TGF-β, increased elastin deposition and vascularization in the infarcted region, and improved functional outcomes after six weeks. Our results demonstrate the efficacy of these discrete anti-fibrotic microstructures and suggest a potential therapeutic materials approach for combatting pathologic fibrosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anti-Inflammation Activities of Mycosporine-Like Amino Acids (MAAs) in Response to UV Radiation Suggest Potential Anti-Skin Aging Activity

PubMed Central

Suh, Sung-Suk; Hwang, Jinik; Park, Mirye; Seo, Hyo Hyun; Kim, Hyoung-Shik; Lee, Jeong Hun; Moh, Sang Hyun; Lee, Taek-Kyun

2014-01-01

Certain photosynthetic marine organisms have evolved mechanisms to counteract UV-radiation by synthesizing UV-absorbing compounds, such as mycosporine-like amino acids (MAAs). In this study, MAAs were separated from the extracts of marine green alga Chlamydomonas hedleyi using HPLC and were identified as porphyra-334, shinorine, and mycosporine-glycine (mycosporine-Gly), based on their retention times and maximum absorption wavelengths. Furthermore, their structures were confirmed by triple quadrupole MS/MS. Their roles as UV-absorbing compounds were investigated in the human fibroblast cell line HaCaT by analyzing the expression levels of genes associated with antioxidant activity, inflammation, and skin aging in response to UV irradiation. The mycosporine-Gly extract, but not the other MAAs, had strong antioxidant activity in the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Furthermore, treatment with mycosporine-Gly resulted in a significant decrease in COX-2 mRNA levels, which are typically increased in response to inflammation in the skin, in a concentration-dependent manner. Additionally, in the presence of MAAs, the UV-suppressed genes, procollagen C proteinase enhancer (PCOLCE) and elastin, which are related to skin aging, had increased expression levels equal to those in UV-mock treated cells. Interestingly, the increased expression of involucrin after UV exposure was suppressed by treatment with the MAAs mycosporine-Gly and shinorine, but not porphyra-334. This is the first report investigating the biological activities of microalgae-derived MAAs in human cells. PMID:25317535

Anti-inflammation activities of mycosporine-like amino acids (MAAs) in response to UV radiation suggest potential anti-skin aging activity.

PubMed

Suh, Sung-Suk; Hwang, Jinik; Park, Mirye; Seo, Hyo Hyun; Kim, Hyoung-Shik; Lee, Jeong Hun; Moh, Sang Hyun; Lee, Taek-Kyun

2014-10-14

Certain photosynthetic marine organisms have evolved mechanisms to counteract UV-radiation by synthesizing UV-absorbing compounds, such as mycosporine-like amino acids (MAAs). In this study, MAAs were separated from the extracts of marine green alga Chlamydomonas hedleyi using HPLC and were identified as porphyra-334, shinorine, and mycosporine-glycine (mycosporine-Gly), based on their retention times and maximum absorption wavelengths. Furthermore, their structures were confirmed by triple quadrupole MS/MS. Their roles as UV-absorbing compounds were investigated in the human fibroblast cell line HaCaT by analyzing the expression levels of genes associated with antioxidant activity, inflammation, and skin aging in response to UV irradiation. The mycosporine-Gly extract, but not the other MAAs, had strong antioxidant activity in the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Furthermore, treatment with mycosporine-Gly resulted in a significant decrease in COX-2 mRNA levels, which are typically increased in response to inflammation in the skin, in a concentration-dependent manner. Additionally, in the presence of MAAs, the UV-suppressed genes, procollagen C proteinase enhancer (PCOLCE) and elastin, which are related to skin aging, had increased expression levels equal to those in UV-mock treated cells. Interestingly, the increased expression of involucrin after UV exposure was suppressed by treatment with the MAAs mycosporine-Gly and shinorine, but not porphyra-334. This is the first report investigating the biological activities of microalgae-derived MAAs in human cells.

Biophysical characterization of a de novo elastin

NASA Astrophysics Data System (ADS)

Greenland, Kelly Nicole

Natural human elastin is found in tissue such as the lungs, arteries, and skin. This protein is formed at birth with no mechanism present to repair or supplement the initial quantity formed. As a result, the functionality and durability of elastin's elasticity is critically important. To date, the mechanics of this ability to stretch and recoil is not fully understood. This study utilizes de novo protein design to create a small library of simplistic versions of elastin-like proteins, demonstrate the elastin-like proteins, maintain elastin's functionality, and inquire into its structure using solution nuclear magnetic resonance (NMR). Elastin is formed from cross-linked tropoelastin. Therefore, the first generation of designed proteins consisted of one protein that utilized homogony of interspecies tropoelastin by using three common domains, two hydrophobic and one cross-linking domains. Basic modifications were made to open the hydrophobic region and also to make the protein easier to purify and characterize. The designed protein maintained its functionality, self-aggregating as the temperature increased. Uniquely, the protein remained self-aggregated as the temperature returned below the critical transition temperature. Self-aggregation was additionally induced by increasing salt concentrations and by modifying the pH. The protein appeared to have little secondary structure when studied with solution NMR. These results fueled a second generation of designed elastin-like proteins. This generation contained variations designed to study the cross-linking domain, one specific hydrophobic domain, and the effect of the length of the elastin-like protein. The cross-linking domain in one variation has been significantly modified while the flanking hydrophobic domains have remained unchanged. This characterization of this protein will answer questions regarding the specificity of the homologous nature of the cross-linking domain of tropoelastin across species. A second protein has additional hydrophobic domains flanking the originally designed elastin-like protein. The characterization of this protein will answer questions regarding the functionality of longer or more hydrophobic elastin-like proteins. The final variation designed is one hydrophobic domain and the new cross-linking domain repeating several times. The characterization of this protein will answer questions regarding the specific hydrophobic domain and its functionality.

Use of elastin fibre detection in the diagnosis of ventilator associated pneumonia.

PubMed

el-Ebiary, M; Torres, A; González, J; Martos, A; Puig de la Bellacasa, J; Ferrer, M; Rodriguez-Roisin, R

1995-01-01

Elastin fibre detection could be a simple and reliable marker of ventilator associated pneumonia. To confirm this, a prospective study was undertaken to evaluate the diagnostic yield of elastin fibre detection in the diagnosis of ventilator associated pneumonia. Seventy eight mechanically ventilated patients were evaluated by examining endotracheal aspirates for the presence of elastin fibres. All patients were previously treated with antibiotics. Quantitative bacterial cultures of endotracheal aspirates and protected specimen brush samples were also performed. Patients were classified into three diagnostic categories: group 1, definite pneumonia (n = 25); group 2, probable pneumonia (n = 35); and group 3, controls (n = 18). Patients with definite and probable pneumonia were grouped together. The presence of elastin fibres in endotracheal aspirate samples was more frequent in groups 1 and 2, being found in 19 of the 60 patients compared with five of the control group. Although the presence of elastin fibres had a low sensitivity (32%), it was a reasonably specific marker (72%) of pneumonia. This specificity increased to 86% and 81% respectively when only Gram negative bacilli and Pseudomonas aeruginosa pneumonia were considered. Again, calculated sensitivity was 43% and 44% when analysing cases infected by Gram negative bacilli and Ps aeruginosa, respectively. The negative predictive value of the detection of elastin fibres in pneumonia caused by Ps aeruginosa was 81%. Detection was more frequent with infection by Gram negative bacilli (14/19), particularly with Ps aeruginosa (8/14). By contrast, pneumonia due to Gram positive cocci or non-bacterial agents uncommonly resulted in positive elastin fibre preparations (4/19, 21%). When analysing patients with and without chronic obstructive pulmonary disease, the diagnostic value of elastin fibre detection did not change. Potassium hydroxide preparation of elastin fibres is a rapid and simple specific marker of ventilator associated pneumonia and may be a useful technique to help diagnose pulmonary infections in mechanically ventilated patients, although this assessment is at present limited to patients without adult respiratory distress syndrome.

Use of elastin fibre detection in the diagnosis of ventilator associated pneumonia.

PubMed Central

el-Ebiary, M.; Torres, A.; González, J.; Martos, A.; Puig de la Bellacasa, J.; Ferrer, M.; Rodriguez-Roisin, R.

1995-01-01

BACKGROUND--Elastin fibre detection could be a simple and reliable marker of ventilator associated pneumonia. To confirm this, a prospective study was undertaken to evaluate the diagnostic yield of elastin fibre detection in the diagnosis of ventilator associated pneumonia. METHODS--Seventy eight mechanically ventilated patients were evaluated by examining endotracheal aspirates for the presence of elastin fibres. All patients were previously treated with antibiotics. Quantitative bacterial cultures of endotracheal aspirates and protected specimen brush samples were also performed. Patients were classified into three diagnostic categories: group 1, definite pneumonia (n = 25); group 2, probable pneumonia (n = 35); and group 3, controls (n = 18). RESULTS--Patients with definite and probable pneumonia were grouped together. The presence of elastin fibres in endotracheal aspirate samples was more frequent in groups 1 and 2, being found in 19 of the 60 patients compared with five of the control group. Although the presence of elastin fibres had a low sensitivity (32%), it was a reasonably specific marker (72%) of pneumonia. This specificity increased to 86% and 81% respectively when only Gram negative bacilli and Pseudomonas aeruginosa pneumonia were considered. Again, calculated sensitivity was 43% and 44% when analysing cases infected by Gram negative bacilli and Ps aeruginosa, respectively. The negative predictive value of the detection of elastin fibres in pneumonia caused by Ps aeruginosa was 81%. Detection was more frequent with infection by Gram negative bacilli (14/19), particularly with Ps aeruginosa (8/14). By contrast, pneumonia due to Gram positive cocci or non-bacterial agents uncommonly resulted in positive elastin fibre preparations (4/19, 21%). When analysing patients with and without chronic obstructive pulmonary disease, the diagnostic value of elastin fibre detection did not change. CONCLUSIONS--Potassium hydroxide preparation of elastin fibres is a rapid and simple specific marker of ventilator associated pneumonia and may be a useful technique to help diagnose pulmonary infections in mechanically ventilated patients, although this assessment is at present limited to patients without adult respiratory distress syndrome. PMID:7886642

Elastin-like polypeptide matrices for enhancing adeno-associated virus-mediated gene delivery to human neural stem cells.

PubMed

Kim, J-S; Chu, H S; Park, K I; Won, J-I; Jang, J-H

2012-03-01

The successful development of efficient and safe gene delivery vectors continues to be a major obstacle to gene delivery in stem cells. In this study, we have developed an elastin-like polypeptide (ELP)-mediated adeno-associated virus (AAV) delivery system for transducing fibroblasts and human neural stem cells (hNSCs). AAVs have significant promise as therapeutic vectors because of their safety and potential for use in gene targeting in stem cell research. ELP has been recently employed as a biologically inspired 'smart' biomaterial that exhibits an inverse temperature phase transition, thereby demonstrating promise as a novel drug carrier. The ELP that was investigated in this study was composed of a repetitive penta-peptide with [Val-Pro-Gly-Val-Gly]. A novel AAV variant, AAV r3.45, which was previously engineered by directed evolution to enhance transduction in rat NSCs, was nonspecifically immobilized onto ELPs that were adsorbed beforehand on a tissue culture polystyrene surface (TCPS). The presence of different ELP quantities on the TCPS led to variations in surface morphology, roughness and wettability, which were ultimately key factors in the modulation of cellular transduction. Importantly, with substantially reduced viral quantities compared with bolus delivery, ELP-mediated AAV delivery significantly enhanced delivery efficiency in fibroblasts and hNSCs, which have great potential for use in tissue engineering applications and neurodegenerative disorder treatments, respectively. The enhancement of cellular transduction in stem cells, as well as the feasibility of ELPs for utilization in three-dimensional scaffolds, will contribute to the advancement of gene therapy for stem cell research and tissue regenerative medicine.

Degradation of tropoelastin and skin elastin by neprilysin.

PubMed

Mora Huertas, Angela C; Schmelzer, Christian E H; Luise, Chiara; Sippl, Wolfgang; Pietzsch, Markus; Hoehenwarter, Wolfgang; Heinz, Andrea

2018-03-01

Neprilysin is also known as skin fibroblast-derived elastase, and its up-regulation during aging is associated with impairments of the elastic fiber network, loss of skin elasticity and wrinkle formation. However, information on its elastase activity is still limited. The aim of this study was to investigate the degradation of fibrillar skin elastin by neprilysin and the influence of the donor's age on the degradation process using mass spectrometry and bioinformatics approaches. The results showed that cleavage by neprilysin is dependent on previous damage of elastin. While neprilysin does not cleave young and intact skin elastin well, it degrades elastin fibers from older donors, which may further promote aging processes. With regards to the cleavage behavior of neprilysin, a strong preference for Gly at P1 was found, while Gly, Ala and Val were well accepted at P1' upon cleavage of tropoelastin and skin elastin. The results of the study indicate that the progressive release of bioactive elastin peptides by neprilysin upon skin aging may enhance local tissue damage and accelerate extracellular matrix aging processes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Extraction and characterization of elastin from poultry skin

NASA Astrophysics Data System (ADS)

Nadalian, Mehdi; Yusop, Salma Mohamad; Mustapha, Wan Aida Wan; Azman, Mohd Azri; Babji, Abdul Salam

2013-11-01

Poultry by-products have a great economic potential that need to be exploited. Poultry skin could be utilized to produce elastin, which is often incorporated in the production of functional food or medicine due to its antioxidative properties. This study was conducted to determine the physicochemical and microstructural characteristics of elastins isolated from broiler and spent hen skin. Analyses including proximate and amino acid composition along with transmission electron microscopy (TEM) were carried out. In this study, elastin was successfully extracted from broiler and spent hen skin using three successive solvents extract of NaCl, acetone and NaOH respectively. It was apparent that the fat content of extracted elastin from broiler skin was higher (P < 0.05) than spent hen's, with both samples recording less than 1% fat. Moreover, broiler skin elastin also had a higher protein content (68.3%) than spent hen's (67.8%). Both skin sources contained glycine as the major amino acid (19-20%), followed by glutamic acid, proline, alanine and arginine. The results of TEM indicated that the use of collagenase enzyme or further purification efforts should be incorporated along with the extraction methods used because of the presence of collagen and other debris in the resultant elastin.

Remote Exosites of the Catalytic Domain of Matrix Metalloproteinase-12 Enhance Elastin Degradation┼

PubMed Central

Fulcher, Yan G.; Van Doren, Steven R.

2011-01-01

How does matrix metalloproteinase-12 (MMP-12 or metalloelastase) degrade elastin with high specific activity? NMR suggested soluble elastin to cover surfaces of MMP-12 far from its active site. Two of these surfaces have been found, by mutagenesis guided by the BINDSIght approach, to affect degradation and affinity for elastin substrates but not a small peptide substrate. Main exosite 1 has been extended out to Asp124 that binds calcium. Novel exosite 2 comprises residues from the II–III loop and β-strand I near the back of the catalytic domain. The high exposure of these distal exosites may make them accessible to elastin made more flexible by partial hydrolysis. Importantly, combination of a lesion at each of exosites 1 and 2 and active site decreased catalytic competence towards soluble elastin by 13- to 18-fold to the level of MMP-3, homologue and poor elastase. Double mutant cycle analysis of conservative mutations of Met156 (exosite 2) and either Asp124 (exosite 1) or Ile180 (active site) had additive effects. Compared to polar substitutions observed in other MMPs, Met156 enhanced affinity and Ile180 kcat for soluble elastin. Both residues detracted from the higher folding stability with polar mutations. This resembles the trend in enzymes of an inverse relationship between folding stability and activity. Restoring Asp124 from combination mutants enhanced kcat for soluble elastin. In elastin degradation, exosites 1 and 2 contributed independently of each other and Ile180 at the active site, but with partial coupling to Ala182 near the active site. The concept of weak, separated interactions coalescing somewhat independently can be extended to this proteolytic digestion of a protein from fibrils. PMID:21967233

Broadband diffuse optical characterization of elastin for biomedical applications.

PubMed

Konugolu Venkata Sekar, Sanathana; Beh, Joo Sin; Farina, Andrea; Dalla Mora, Alberto; Pifferi, Antonio; Taroni, Paola

2017-10-01

Elastin is a key structural protein of dynamic connective tissues widely found in the extracellular matrix of skin, arteries, lungs and ligaments. It is responsible for a range of diseases related to aging of biological tissues. The optical characterization of elastin can open new opportunities for its investigation in biomedical studies. In this work, we present the absorption spectra of elastin using a broadband (550-1350nm) diffuse optical spectrometer. Distortions caused by fluorescence and finite bandwidth of the laser source on estimated absorption were effectively accounted for in measurements and data analysis and compensated. A comprehensive summary and comparison between collagen and elastin is presented, highlighting distinct features for its accurate quantification in biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Elastin in the human intervertebral disk. A histological and biochemical study comparing it with elastin in the human yellow ligament.

PubMed

Mikawa, Y; Hamagami, H; Shikata, J; Yamamuro, T

1986-01-01

The elastic fiber and elastin in the human yellow ligament and intervertebral disk were studied histologically and biochemically. The elastic fiber in the human intervertebral disk, which until now had not been clearly identified microscopically, was observed clearly. We found the distribution of the elastic fiber in the intervertebral disk to be very sparse and irregular, and its diameter was small, being about one-tenth of that found in the yellow ligament. The elastin contents of the yellow ligament and intervertebral disk were 46.7% +/- 0.9% and 1.7% +/- 0.2% respectively (mean +/- SE) of the total dry weight. The amino acid composition of elastin in the yellow ligament is similar to that of other tissue, as reported in the literature; however, that found in the intervertebral disk is significantly different. It would appear, therefore, that the elastin in the intervertebral disk is of a different type from that found elsewhere.

Details of the Collagen and Elastin Architecture in the Human Limbal Conjunctiva, Tenon's Capsule and Sclera Revealed by Two-Photon Excited Fluorescence Microscopy.

PubMed

Park, Choul Yong; Marando, Catherine M; Liao, Jason A; Lee, Jimmy K; Kwon, Jiwon; Chuck, Roy S

2016-10-01

To investigate the architecture and distribution of collagen and elastin in human limbal conjunctiva, Tenon's capsule, and sclera. The limbal conjunctiva, Tenon's capsule, and sclera of human donor corneal buttons were imaged with an inverted two-photon excited fluorescence microscope. No fixation process was necessary. The laser (Ti:sapphire) was tuned at 850 nm for two-photon excitation. Backscatter signals of second harmonic generation (SHG) and autofluorescence (AF) were collected through a 425/30-nm and a 525/45-nm emission filter, respectively. Multiple, consecutive, and overlapping (z-stack) images were acquired. Collagen signals were collected with SHG, whereas elastin signals were collected with AF. The size and density of collagen bundles varied widely depending on depth: increasing from conjunctiva to sclera. In superficial image planes, collagen bundles were <10 μm in width, in a loose, disorganized arrangement. In deeper image planes (episclera and superficial sclera), collagen bundles were thicker (near 100 μm in width) and densely packed. Comparatively, elastin fibers were thinner and sparse. The orientation of elastin fibers was independent of collagen fibers in superficial layers; but in deep sclera, elastin fibers wove through collagen interbundle gaps. At the limbus, both collagen and elastin fibers were relatively compact and were distributed perpendicular to the limbal annulus. Two-photon excited fluorescence microscopy has enabled us to understand in greater detail the collagen and elastin architecture of the human limbal conjunctiva, Tenon's capsule, and sclera.

Genome and transcriptome studies of the protozoan parasites Trypanosoma cruzi and Giardia intestinalis

NASA Astrophysics Data System (ADS)

Farran, Alexandra J. E.

Vocal fold (VF) diseases and disorders are difficult to treat surgically or therapeutically. Tissue engineering offers an alternative strategy for the restoration of functional VF. In this work, we have developed tissue engineering methodologies for the functional reconstruction of VF. As a first step, the structure, composition and mechanical properties of native VF tissues have been investigated. In pigs ranging from fetal to 2+ years old, the VF structure and viscoelastic properties were found to be age-dependent. Adult tissues were more organized, displaying a denser lamina propria, and mature elastin fibers compared to fetal tissues, resulting in higher storage moduli. Secondly, biomimetic scaffolds which recaptured the mechanical properties of the native VF were developed. Chemically-defined collagen-hyaluronic acid (HA) composite hydrogels, and elastin-mimetic hybrid polymers (EMHPs) were successfully used as conducive 3D matrices, and 2D elastic scaffolds respectively, to in vitro static culture of fibroblasts. While the collagen-HA hydrogels allowed for in situ cell encapsulation and supported cell attachment and proliferation in 3D, the integrin-binding domain RGDSP was needed for cell proliferation on EMHPs. To emulate in vitro the mechanical environment of the native VF tissue, a dynamic culture system capable of generating vibratory stimulations at human phonation frequencies was successfully created and characterized. Gene expression analysis of fibroblasts subjected to 1 hour vibrations in 2D revealed that the expression of ECM-related genes was altered in response to changes in vibratory frequency and amplitude. Finally, expanding on our previous studies, the dynamic culture system was modified to accommodate for the long-term dynamic culture of cell-laden hydrogels. Human mesenchymal stem cells (hMSCs) encapsulated in a collagen/HA-based hydrogel, cultured in presence of connective tissue growth factor (CTGF), and subjected to high frequency vibrations were shown to respond to all three type of external factors. In summary, microenvironments such as biomimetic scaffolds, soluble factors, and mechanical stimuli are important modulator of cellular function. The strategic combination of those microenvironments into a biomimicking VF tissue engineering 3D system did not only provide an in vitro platform for the investigation of VF diseases, but also have the potential to offer alternative treatments for VF disorders.

LOXL1 deficiency in the lamina cribrosa as candidate susceptibility factor for a pseudoexfoliation-specific risk of glaucoma.

PubMed

Schlötzer-Schrehardt, Ursula; Hammer, Christian M; Krysta, Anita W; Hofmann-Rummelt, Carmen; Pasutto, Francesca; Sasaki, Takako; Kruse, Friedrich E; Zenkel, Matthias

2012-09-01

To test the hypothesis that a primary disturbance in lysyl oxidase-like 1 (LOXL1) and elastin metabolism in the lamina cribrosa of eyes with pseudoexfoliation syndrome constitutes an independent risk factor for glaucoma development and progression. Observational, consecutive case series. Posterior segment tissues obtained from 37 donors with early and late stages of pseudoexfoliation syndrome without glaucoma, 37 normal age-matched control subjects, 5 eyes with pseudoexfoliation-associated open-angle glaucoma, and 5 eyes with primary open-angle glaucoma (POAG). Protein and mRNA expression of major elastic fiber components (elastin, fibrillin-1, fibulin-4), collagens (types I, III, and IV), and lysyl oxidase crosslinking enzymes (LOX, LOXL1, LOXL2) were assessed in situ by quantitative real-time polymerase chain reaction, (immuno)histochemistry, and light and electron microscopy. Lysyl oxidase-dependent elastin fiber assembly was assessed by primary optic nerve head astrocytes in vitro. Expression levels of elastic proteins, collagens, and lysyl oxidases in the lamina cribrosa. Lysyl oxidase-like 1 proved to be the major lysyl oxidase isoform in the normal lamina cribrosa in association with a complex elastic fiber network. Compared with normal and POAG specimens, lamina cribrosa tissues obtained from early and late stages of pseudoexfoliation syndrome without and with glaucoma consistently revealed a significant coordinated downregulation of LOXL1 and elastic fiber constituents on mRNA and protein level. In contrast, expression levels of collagens and other lysyl oxidase isoforms were not affected. Dysregulated expression of LOXL1 and elastic proteins was associated with pronounced (ultra)structural alterations of the elastic fiber network in the laminar beams of pseudoexfoliation syndrome eyes. Inhibition of LOXL1 interfered with elastic fiber assembly by optic nerve head astrocytes in vitro. The findings provide evidence for a pseudoexfoliation-specific elastinopathy of the lamina cribrosa resulting from a primary disturbance in LOXL1 regulation and elastic fiber homeostasis, possibly rendering pseudoexfoliation syndrome eyes more vulnerable to pressure-induced optic nerve damage and glaucoma development and progression. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Extraction and characterization of elastin from poultry skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nadalian, Mehdi; Yusop, Salma Mohamad; Mustapha, Wan Aida Wan

2013-11-27

Poultry by-products have a great economic potential that need to be exploited. Poultry skin could be utilized to produce elastin, which is often incorporated in the production of functional food or medicine due to its antioxidative properties. This study was conducted to determine the physicochemical and microstructural characteristics of elastins isolated from broiler and spent hen skin. Analyses including proximate and amino acid composition along with transmission electron microscopy (TEM) were carried out. In this study, elastin was successfully extracted from broiler and spent hen skin using three successive solvents extract of NaCl, acetone and NaOH respectively. It was apparentmore » that the fat content of extracted elastin from broiler skin was higher (P < 0.05) than spent hen’s, with both samples recording less than 1% fat. Moreover, broiler skin elastin also had a higher protein content (68.3%) than spent hen’s (67.8%). Both skin sources contained glycine as the major amino acid (19–20%), followed by glutamic acid, proline, alanine and arginine. The results of TEM indicated that the use of collagenase enzyme or further purification efforts should be incorporated along with the extraction methods used because of the presence of collagen and other debris in the resultant elastin.« less

Controlled release of ascorbic acid from gelatin hydrogel attenuates abdominal aortic aneurysm formation in rat experimental abdominal aortic aneurysm model.

PubMed

Tanaka, Akiko; Hasegawa, Tomomi; Morimoto, Keisuke; Bao, Wulan; Yu, Jie; Okita, Yutaka; Tabata, Yasuhiko; Okada, Kenji

2014-09-01

Abdominal aortic aneurysms (AAAs) are associated with oxidative stress and inflammatory response. We investigated the hypothesis that the known antioxidant ascorbic acid, which can also promote elastin and collagen production by smooth muscle cells, would prevent AAA formation in a rat model. An intraluminal elastase and extraluminal calcium chloride-induced rat AAA model was used, and the animals were divided into three groups: control (group C, n = 18), the aorta wrapped with a saline-impregnated gelatin hydrogel sheet (group G, n = 18), and the aorta wrapped with a gelatin hydrogel sheet incorporating ascorbic acid (group A, n = 18). Wrapping of the sheet was completed at the end of treatment for AAA creation. The aortic dilatation ratio was measured, and aortic tissues were further examined for oxidative stress and oxidative DNA damage using biochemical and histologic techniques. Aortic dilatation at both 4 and 8 weeks was inhibited in group A (dilatation ratio [%] at 4 weeks: 186.2 ± 21.8 in group C, 152.3 ± 10.2 in group G, 126.8 ± 11.6 in group A; P < .0001; dilatation ratio [%] at 8 weeks: 219.3 ± 37.5 in group C, 194.0 ± 11.6 in group G, 145.7 ± 8.3 in group A; P = .0002). Elastin and collagen content were significantly preserved in group A (elastin, P = .0015; collagen, P < .0001). The messenger RNA expressions of matrix metalloproteinase (MMP)-9, monocyte chemotactic protein-1, interleukin-1β, and tissue necrosis factor-α (P = .0024, P < .0001, P < .0001, and P < .0001, respectively) were downregulated in group A (P = .0024), whereas tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 were both upregulated in group A (TIMP-1, P = .0014; TIMP-2, P < .0001). Gelatin zymography showed activities of pro-MMP-2, MMP-2, and MMP-9 were significantly suppressed in group C (P < .0001 for each). Reactive oxygen species expression and 8-hydroxydeoxyguanosine and cluster of differentiation 68 staining were significantly suppressed in group A (reactive oxygen species expression, P < .0001; 8-hydroxydeoxyguanosine-positive cells, P < .0001; cluster of differentiation 68 positive cells, P < .0001). Controlled release of ascorbic acid using gelatin hydrogel sheet-attenuated AAA formation through antioxidant and anti-inflammatory effect, regulation of MMP-2, TIMP-1, and TIMP-2, and preserving elastin and collagen in this animal model. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Fourier transform infrared spectroscopy to quantify collagen and elastin in an in vitro model of extracellular matrix degradation in aorta.

PubMed

Cheheltani, Rabee; McGoverin, Cushla M; Rao, Jayashree; Vorp, David A; Kiani, Mohammad F; Pleshko, Nancy

2014-06-21

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues.

Fourier Transform Infrared Spectroscopy to Quantify Collagen and Elastin in an In Vitro Model of Extracellular Matrix Degradation in Aorta

PubMed Central

Cheheltani, Rabee; McGoverin, Cushla M.; Rao, Jayashree; Vorp, David A.; Kiani, Mohammad F.; Pleshko, N.

2014-01-01

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues. PMID:24761431

Elastin Shapes Small Molecule Distribution in Lymph Node Conduits.

PubMed

Lin, Yujia; Louie, Dante; Ganguly, Anutosh; Wu, Dequan; Huang, Peng; Liao, Shan

2018-05-01

The spatial and temporal Ag distribution determines the subsequent T cell and B cell activation at the distinct anatomical locations in the lymph node (LN). It is well known that LN conduits facilitate small Ag distribution in the LN, but the mechanism of how Ags travel along LN conduits remains poorly understood. In C57BL/6J mice, using FITC as a fluorescent tracer to study lymph distribution in the LN, we found that FITC preferentially colocalized with LN capsule-associated (LNC) conduits. Images generated using a transmission electron microscope showed that LNC conduits are composed of solid collagen fibers and are wrapped with fibroblastic cells. Superresolution images revealed that high-intensity FITC is typically colocalized with elastin fibers inside the LNC conduits. Whereas tetramethylrhodamine isothiocyanate appears to enter LNC conduits as effectively as FITC, fluorescently-labeled Alexa-555-conjugated OVA labels significantly fewer LNC conduits. Importantly, injection of Alexa-555-conjugated OVA with LPS substantially increases OVA distribution along elastin fibers in LNC conduits, indicating immune stimulation is required for effective OVA traveling along elastin in LN conduits. Finally, elastin fibers preferentially surround lymphatic vessels in the skin and likely guide fluid flow to the lymphatic vessels. Our studies demonstrate that fluid or small molecules are preferentially colocalized with elastin fibers. Although the exact mechanism of how elastin fibers regulate Ag trafficking remains to be explored, our results suggest that elastin can be a potentially new target to direct Ag distribution in the LN during vaccine design. Copyright © 2018 by The American Association of Immunologists, Inc.

Tyrosinase-Mediated Construction of a Silk Fibroin/Elastin Nanofiber Bioscaffold.

PubMed

Hong, Yanqing; Zhu, Xueke; Wang, Ping; Fu, Haitian; Deng, Chao; Cui, Li; Wang, Qiang; Fan, Xuerong

2016-04-01

Elastin has characteristics of elasticity, biological activity, and mechanical stability. In the present work, tyrosinase-mediated construction of a bioscaffold with silk fibroin and elastin was carried out, aiming at developing a novel medical biomaterial. The efficiency of enzymatic oxidation of silk fibroin and the covalent reaction between fibroin and elastin were examined by spectrophotometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and size exclusion chromatography (SEC). The properties of composite air-dried and nanofiber scaffolds were investigated. The results reveal that elastin was successfully bonded to silk fibroins, resulting in an increase in molecular weight of fibroin proteins. ATR-FTIR spectra indicated that tyrosinase treatment impacted the conformational structure of fibroin-based membrane. The thermal behaviors and mechanical properties of the tyrosinase-treated scaffolds were also improved compared with the untreated group. NIH/3T3 cells exhibited optimum densities when grown on the nanofiber scaffold, implying that the nanofiber scaffold has enhanced biocompatibility compared to the air-dried scaffold. A biological nanofiber scaffold constructed from tyrosinase-treated fibroin and elastin could potentially be utilized in biomedical applications.

Effect of elastin-derived peptides on the production of tissue inhibitor of metalloproteinase-1, -2, and -3 and the ratios in various endothelial cell lines.

PubMed

Siemianowicz, Krzysztof; Likus, Wirginia; Francuz, Tomasz; Garczorz, Wojciech

2015-06-01

Tissue inhibitors of metalloproteinases (TIMPs) control the activity of metalloproteinases. Elastin-derived peptides (EDPs) are generated as a result of the degradation of elastin fibers. The EDPs bind to the elastin receptor and exert numerous biological effects. The aim of the present study was to compare the production of TIMP-1, TIMP-2 and TIMP-3 and their ratios in human endothelial cells (ECs) derived from three clinically important vascular localizations (coronary arteries, aorta and iliac artery), and evaluate the influence of a well-known EDP, κ-elastin. The highest concentration of TIMP-1 was identified in the aortic ECs, while the lowest concentration was observed in the ECs derived from the coronary artery. The opposite pattern was observed for TIMP-2 production. When the TIMP-3 concentration was analyzed in the three EC lines, no statistically significant differences were observed. Application of κ-elastin was found to decrease the TIMP-1 concentration in the aortic ECs, while an increase in the TIMP-1 concentration was observed in the ECs derived from the iliac artery. The most significant decrease in TIMP-2 concentration following κ-elastin administration was observed in the ECs obtained from the coronary arteries. Furthermore, the highest concentration of κ-elastin resulted in an increase in TIMP-3 production in the ECs derived from the coronary arteries. The following ratios of the TIMP concentrations were calculated: TIMP-1/TIMP-2, TIMP-1/TIMP-3 and TIMP-2/TIMP-3. Each ratio presented different values for the ECs obtained from the various localizations. In the majority of cases, the addition of κ-elastin did not significantly change these proportions. Therefore, these indicators may be characteristic features that can be used to describe ECs in various clinically important vascular localizations.

Effect of elastin-derived peptides on the production of tissue inhibitor of metalloproteinase-1, -2, and -3 and the ratios in various endothelial cell lines

PubMed Central

SIEMIANOWICZ, KRZYSZTOF; LIKUS, WIRGINIA; FRANCUZ, TOMASZ; GARCZORZ, WOJCIECH

2015-01-01

Tissue inhibitors of metalloproteinases (TIMPs) control the activity of metalloproteinases. Elastin-derived peptides (EDPs) are generated as a result of the degradation of elastin fibers. The EDPs bind to the elastin receptor and exert numerous biological effects. The aim of the present study was to compare the production of TIMP-1, TIMP-2 and TIMP-3 and their ratios in human endothelial cells (ECs) derived from three clinically important vascular localizations (coronary arteries, aorta and iliac artery), and evaluate the influence of a well-known EDP, κ-elastin. The highest concentration of TIMP-1 was identified in the aortic ECs, while the lowest concentration was observed in the ECs derived from the coronary artery. The opposite pattern was observed for TIMP-2 production. When the TIMP-3 concentration was analyzed in the three EC lines, no statistically significant differences were observed. Application of κ-elastin was found to decrease the TIMP-1 concentration in the aortic ECs, while an increase in the TIMP-1 concentration was observed in the ECs derived from the iliac artery. The most significant decrease in TIMP-2 concentration following κ-elastin administration was observed in the ECs obtained from the coronary arteries. Furthermore, the highest concentration of κ-elastin resulted in an increase in TIMP-3 production in the ECs derived from the coronary arteries. The following ratios of the TIMP concentrations were calculated: TIMP-1/TIMP-2, TIMP-1/TIMP-3 and TIMP-2/TIMP-3. Each ratio presented different values for the ECs obtained from the various localizations. In the majority of cases, the addition of κ-elastin did not significantly change these proportions. Therefore, these indicators may be characteristic features that can be used to describe ECs in various clinically important vascular localizations. PMID:26136968

Targeting prostate cancer cells with hybrid elastin-like polypeptide/liposome nanoparticles

PubMed Central

Zhang, Wei; Song, Yunmei; Eldi, Preethi; Guo, Xiuli; Hayball, John D; Garg, Sanjay; Albrecht, Hugo

2018-01-01

Prostate cancer cells frequently overexpress the gastrin-releasing peptide receptor, and various strategies have been applied in preclinical settings to target this receptor for the specific delivery of anticancer compounds. Recently, elastin-like polypeptide (ELP)-based self-assembling micelles with tethered GRP on the surface have been suggested to actively target prostate cancer cells. Poorly soluble chemotherapeutics such as docetaxel (DTX) can be loaded into the hydrophobic cores of ELP micelles, but only limited drug retention times have been achieved. Herein, we report the generation of hybrid ELP/liposome nanoparticles which self-assembled rapidly in response to temperature change, encapsulated DTX at high concentrations with slow release, displayed the GRP ligand on the surface, and specifically bound to GRP receptor expressing PC-3 cells as demonstrated by flow cytometry. This novel type of drug nanocarrier was successfully used to reduce cell viability of prostate cancer cells in vitro through the specific delivery of DTX. PMID:29391790

Physiological regulation of extracellular matrix collagen and elastin in the arterial wall of rats by noradrenergic tone and angiotensin II.

PubMed

Dab, Houcine; Kacem, Kamel; Hachani, Rafik; Dhaouadi, Nadra; Hodroj, Wassim; Sakly, Mohsen; Randon, Jacques; Bricca, Giampiero

2012-03-01

The interactions between the effects of the sympathetic nervous system (SNS) and angiotensin II (ANG II) on vascular extracellular matrix (ECM) synthesis were determined in rats. The mRNA and protein content of collagen I, collagen III and elastin in the abdominal aorta (AA) and femoral artery (FA) was investigated in Wistar-Kyoto rats treated for 5 weeks with guanethidine, a sympathoplegic, losartan, an ANG II AT1 receptor (AT1R) blocker, or both. The effects of noradrenaline (NE) and ANG II on collagen III and elastin mRNA, and the receptor involved, were tested in cultured vascular smooth muscle cells (VSMCs) in vitro. Guanethidine increased collagen types I and III and decreased elastin, while losartan had an opposite effect, although without effect on collagen III. The combination of treatments abrogated changes induced by simple treatment with collagen I and elastin, but increased collagen III mRNA in AA and not in FA. NE stimulated collagen III mRNA via β receptors and elastin via α1 and α2 receptors. ANG II stimulated collagen III but inhibited elastin mRNA via AT1R. Overall, SNS and ANG II exert opposite and antagonistic effects on major components of ECM in the vascular wall. This may be of relevance for the choice of a therapeutic strategy in vascular diseases.

Proline-poor hydrophobic domains modulate the assembly and material properties of polymeric elastin.

PubMed

Muiznieks, Lisa D; Reichheld, Sean E; Sitarz, Eva E; Miao, Ming; Keeley, Fred W

2015-10-01

Elastin is a self-assembling extracellular matrix protein that provides elasticity to tissues. For entropic elastomers such as elastin, conformational disorder of the monomer building block, even in the polymeric form, is essential for elastomeric recoil. The highly hydrophobic monomer employs a range of strategies for maintaining disorder and flexibility within hydrophobic domains, particularly involving a minimum compositional threshold of proline and glycine residues. However, the native sequence of hydrophobic elastin domain 30 is uncharacteristically proline-poor and, as an isolated polypeptide, is susceptible to formation of amyloid-like structures comprised of stacked β-sheet. Here we investigated the biophysical and mechanical properties of multiple sets of elastin-like polypeptides designed with different numbers of proline-poor domain 30 from human or rat tropoelastins. We compared the contributions of these proline-poor hydrophobic sequences to self-assembly through characterization of phase separation, and to the tensile properties of cross-linked, polymeric materials. We demonstrate that length of hydrophobic domains and propensity to form β-structure, both affecting polypeptide chain flexibility and cross-link density, play key roles in modulating elastin mechanical properties. This study advances the understanding of elastin sequence-structure-function relationships, and provides new insights that will directly support rational approaches to the design of biomaterials with defined suites of mechanical properties. © 2015 Wiley Periodicals, Inc.

Ligand affinity of the 67-kD elastin/laminin binding protein is modulated by the protein's lectin domain: visualization of elastin/laminin-receptor complexes with gold-tagged ligands

PubMed Central

1991-01-01

Video-enhanced microscopy was used to examine the interaction of elastin- or laminin-coated gold particles with elastin binding proteins on the surface of live cells. By visualizing the binding events in real time, it was possible to determine the specificity and avidity of ligand binding as well as to analyze the motion of the receptor-ligand complex in the plane of the plasma membrane. Although it was difficult to interpret the rates of binding and release rigorously because of the possibility for multiple interactions between particles and the cell surface, relative changes in binding have revealed important aspects of the regulation of affinity of ligand-receptor interaction in situ. Both elastin and laminin were found to compete for binding to the cell surface and lactose dramatically decreased the affinity of the receptor(s) for both elastin and laminin. These findings were supported by in vitro studies of the detergent-solubilized receptor. Further, immobilization of the ligand-receptor complexes through binding to the cytoskeleton dramatically decreased the ability of bound particles to leave the receptor. The changes in the kinetics of ligand-coated gold binding to living cells suggest that both laminin and elastin binding is inhibited by lactose and that attachment of receptor to the cytoskeleton increases its affinity for the ligand. PMID:1848864

Elastin density: Link between histological and biomechanical properties of vaginal tissue in women with pelvic organ prolapse?

PubMed

de Landsheere, Laurent; Brieu, Mathias; Blacher, Silvia; Munaut, Carine; Nusgens, Betty; Rubod, Chrystèle; Noel, Agnès; Foidart, Jean-Michel; Nisolle, Michelle; Cosson, Michel

2016-04-01

The aim of the study was to correlate histological and biomechanical characteristics of the vaginal wall in women with pelvic organ prolapse (POP). Tissue samples were collected from the anterior [point Ba; POP Questionnaire (POP-Q)] and/or posterior (point Bp; POP-Q) vaginal wall of 15 women who underwent vaginal surgery for POP. Both histological and biomechanical assessments were performed from the same tissue samples in 14 of 15 patients. For histological assessment, the density of collagen and elastin fibers was determined by combining high-resolution virtual imaging and computer-assisted digital image analysis. For biomechanical testing, uniaxial tension tests were performed to evaluate vaginal tissue stiffness at low (C0) and high (C1) deformation rates. Biomechanical testing highlights the hyperelastic behavior of the vaginal wall. At low strains (C0), vaginal tissue appeared stiffer when elastin density was low. We found a statistically significant inverse relationship between C0 and the elastin/collagen ratio (p = 0.048) in the lamina propria. However, at large strain levels (C1), no clear relationship was observed between elastin density or elastin/collagen ratio and stiffness, likely reflecting the large dispersion of the mechanical behavior of the tissue samples. Histological and biomechanical properties of the vaginal wall vary from patient to patient. This study suggests that elastin density deserves consideration as a relevant factor of vaginal stiffness in women with POP.

MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang

Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a rolemore » in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl{sub 4}-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.« less

Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI).

PubMed

Protti, Andrea; Lavin, Begoña; Dong, Xuebin; Lorrio, Silvia; Robinson, Simon; Onthank, David; Shah, Ajay M; Botnar, Rene M

2015-08-13

Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin-specific contrast agent (Gd-ESMA) was used to image tropoelastin and mature elastin fibers for in vivo assessment of extracellular matrix remodeling post-MI. Gd-ESMA enhancement was studied in a mouse model of myocardial infarction using a 7 T MRI scanner and results were compared to those achieved after injection of a nonspecific control contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the infarcted tissue, Gd-ESMA uptake (measured as R1 relaxation rate) steadily increased from day 3 to day 21 as a result of the synthesis of elastin/tropoelastin. R1 values were in good agreement with histological findings. A similar R1 behavior was observed in the remote myocardium. No mature cross-linked elastin was found at any time point. In contrast, Gd-DTPA uptake was only observed in the infarct with no changes in R1 values between 3 and 21 days post-MI. We demonstrate the feasibility of in vivo imaging of extracellular matrix remodeling post-MI using a tropoelastin/elastin binding MR contrast agent, Gd-ESMA. We found that tropoelastin is the main contributor to the increased MRI signal at late stages of MI where its augmentation in areas of infarction was in good agreement with the R1 increase. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The action of neutrophil serine proteases on elastin and its precursor.

PubMed

Heinz, Andrea; Jung, Michael C; Jahreis, Günther; Rusciani, Anthony; Duca, Laurent; Debelle, Laurent; Weiss, Anthony S; Neubert, Reinhard H H; Schmelzer, Christian E H

2012-01-01

This study aimed to investigate the degradation of the natural substrates tropoelastin and elastin by the neutrophil-derived serine proteases human leukocyte elastase (HLE), proteinase 3 (PR3) and cathepsin G (CG). Focus was placed on determining their cleavage site specificities using mass spectrometric techniques. Moreover, the release of bioactive peptides from elastin by the three proteases was studied. Tropoelastin was comprehensively degraded by all three proteases, whereas less cleavage occurred in mature cross-linked elastin. An analysis of the cleavage site specificities of the three proteases in tropoelastin and elastin revealed that HLE and PR3 similarly tolerate hydrophobic and/or aliphatic amino acids such as Ala, Gly and Val at P(1), which are also preferred by CG. In addition, CG prefers the bulky hydrophobic amino acid Leu and accepts the bulky aromatic amino acids Phe and Tyr. CG shows a strong preference for the charged amino acid Lys at P(1) in tropoelastin, whereas Lys was not identified at P(1) in CG digests of elastin due to extensive cross-linking at Lys residues in mature elastin. All three serine proteases showed a clear preference for Pro at P(2) and P(4)'. With respect to the liberation of potentially bioactive peptides from elastin, the study revealed that all three serine proteases have a similar ability to release bioactive sequences, with CG producing the highest number of these peptides. In bioactivity studies, potentially bioactive peptides that have not been investigated on their bioactivity to date, were tested. Three new bioactive GxxPG motifs were identified; GVYPG, GFGPG and GVLPG. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Purification of Microbially Expressed Recombinant Proteins via a Dual ELP Split Intein System.

PubMed

Shi, Changhua; Han, Tzu-Chiang; Wood, David W

2017-01-01

Fusions of elastin-like peptide (ELP) purification tags and self-cleaving inteins provide a powerful platform for purifying tagless recombinant proteins without the need for conventional packed-bed columns. A drawback to this method has been premature cleaving of the ELP tag during expression, before the purification procedure can take place. Here we demonstrate a split-intein method, where the self-cleaving intein is divided into two inactive segments during expression and purification. Spontaneous assembly of the purified intein segments then restores self-cleaving activity to deliver the tagless target protein.

Cellular senescence of human mammary epithelial cells (HMEC) is associated with an altered MMP-7/HB-EGF signaling and increased formation of elastin-like structures.

PubMed

Bertram, Catharina; Hass, Ralf

2009-10-01

The extracellular matrix (ECM) and a complex interplay of cell-to-cell and cell-to-matrix (ECM) interactions provide important platforms to determine cellular senescence and a potentially tumorigenic transformation of normal human mammary epithelial cells (HMEC). An enhanced formation of extracellular filaments, consisting of elastin-like structures, in senescent post-selection HMEC populations was paralleled by a significantly increased expression of its precursor protein tropoelastin and matched with a markedly elevated activity of the cross-linking enzyme family of lysyl oxidases (LOX). RNAi experiments revealed both the ECM metalloproteinase MMP-7 and the growth factor HB-EGF as potential effectors of an increased tropoelastin expression. Moreover, co-localization of MMP-7 and HB-EGF as well as a concomittant downstream signaling via Fra-1 indicated a possible association between the reduced MMP-7 enzyme activity and an impaired HB-EGF processing, resulting in an enhanced tropoelastin synthesis during senescence of HMEC. In agreement with previous work, these findings suggested an important influence of the extracellular proteinase MMP-7 on the aging process of HMEC, affecting both extracellular remodeling as well as intracellular signaling pathways.

Moyamoya disease and artery tortuosity as rare phenotypes in a patient with an elastin mutation.

PubMed

Ishiwata, Tsukasa; Tanabe, Nobuhiro; Shigeta, Ayako; Yokota, Hajime; Tsushima, Kenji; Terada, Jiro; Sakao, Seiichiro; Morisaki, Hiroko; Morisaki, Takayuki; Tatsumi, Koichiro

2016-07-01

Sporadic and familial elastin mutations can occur in large vessel stenosis such as supravalvular aortic stenosis and narrowing of the descending aorta. However, there are very few reports regarding the arteriopathy of cerebral, pulmonary or abdominal arteries in elastin mutations. We herein report the case of a Japanese female patient presenting with multiple arteriopathy including moyamoya disease, a tortuosity of abdominal arteries and pulmonary hypertension due to peripheral pulmonary artery stenosis. This case suggests the possible progression of cerebral arteriopathy including moyamoya disease in patients with elastin mutations. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Mechanistic Insight into the Elastin Degradation Process by the Metalloprotease Myroilysin from the Deep-Sea Bacterium Myroides profundi D25

PubMed Central

Yang, Jie; Zhao, Hui-Lin; Tang, Bai-Lu; Chen, Xiu-Lan; Su, Hai-Nan; Zhang, Xi-Ying; Song, Xiao-Yan; Zhou, Bai-Cheng; Xie, Bin-Bin; Weiss, Anthony S.; Zhang, Yu-Zhong

2015-01-01

Elastases have been widely studied because of their important uses as medicine and meat tenderizers. However, there are relatively few studies on marine elastases. Myroilysin, secreted by Myroides profundi D25 from deep-sea sediment, is a novel elastase. In this study, we examined the elastin degradation mechanism of myroilysin. When mixed with insoluble bovine elastin, myroilysin bound hydrophobically, suggesting that this elastase may interact with the hydrophobic domains of elastin. Consistent with this, analysis of the cleavage pattern of myroilysin on bovine elastin and recombinant tropoelastin revealed that myroilysin preferentially cleaves peptide bonds with hydrophobic residues at the P1 and/or P1′ positions. Scanning electron microscopy (SEM) of cross-linked recombinant tropoelastin degraded by myroilysin showed preferential damages of spherules over cross-links, as expected for a hydrophobic preference. The degradation process of myroilysin on bovine elastin fibres was followed by light microscopy and SEM, revealing that degradation begins with the formation of crevices and cavities at the fibre surface, with these openings increasing in number and size until the fibre breaks into small pieces, which are subsequently fragmented. Our results are helpful for developing biotechnological applications for myroilysin. PMID:25793427

Evaluation of a biomimetic 3D substrate based on the Human Elastin-like Polypeptides (HELPs) model system for elastolytic activity detection.

PubMed

Corich, Lucia; Busetti, Marina; Petix, Vincenzo; Passamonti, Sabina; Bandiera, Antonella

2017-08-10

Elastin is a fibrous protein that confers elasticity to tissues such as skin, arteries and lung. It is extensively cross-linked, highly hydrophobic and insoluble. Nevertheless, elastin can be hydrolysed by bacterial proteases in infectious diseases, resulting in more or less severe tissue damage. Thus, development of substrates able to reliably and specifically detect pathogen-secreted elastolytic activity is needed to improve the in vitro evaluation of the injury that bacterial proteases may provoke. In this work, two human biomimetic elastin polypeptides, HELP and HELP1, as well as the matrices derived from HELP, have been probed as substrates for elastolytic activity detection. Thirty strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients were analyzed in parallel with standard substrates, to detect proteolytic and elastolytic activity. Results point to the HELP-based 3D matrix as an interesting biomimetic model of elastin to assess bacterial elastolytic activity in vitro. Moreover, this model substrate enables to further elucidate the mechanism underlying elastin degradation at molecular level, as well as to develop biomimetic material-based devices responsive to external stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization

PubMed Central

Misbah, Mohamed Hamed; Santos, Mercedes; Quintanilla, Luis; Günter, Christina; Alonso, Matilde; Taubert, Andreas

2017-01-01

Understanding the mechanisms responsible for generating different phases and morphologies of calcium phosphate by elastin-like recombinamers is supreme for bioengineering of advanced multifunctional materials. The generation of such multifunctional hybrid materials depends on the properties of their counterparts and the way in which they are assembled. The success of this assembly depends on the different approaches used, such as recombinant DNA technology and click chemistry. In the present work, an elastin-like recombinamer bearing lysine amino acids distributed along the recombinamer chain has been cross-linked via Huisgen [2 + 3] cycloaddition. The recombinamer contains the SNA15 peptide domains inspired by salivary statherin, a peptide epitope known to specifically bind to and nucleate calcium phosphate. The benefit of using click chemistry is that the hybrid elastin-like-statherin recombinamers cross-link without losing their fibrillar structure. Mineralization of the resulting hybrid elastin-like-statherin recombinamer hydrogels with calcium phosphate is described. Thus, two different hydroxyapatite morphologies (cauliflower- and plate-like) have been formed. Overall, this study shows that crosslinking elastin-like recombinamers leads to interesting matrix materials for the generation of calcium phosphate composites with potential applications as biomaterials. PMID:28487820

The effect of glycation on arterial microstructure and mechanical response.

PubMed

Stephen, Elizabeth A; Venkatasubramaniam, Arundhathi; Good, Theresa A; Topoleski, L D T

2014-08-01

Like engineered materials, an artery's biomechanical behavior and function depend on its microstructure. Glycation is associated with both normal aging and diabetes and has been shown to increase arterial stiffness. In this study we examined the direct effect of glycation on the mechanical response of intact arteries and on the mechanical response and structure of elastin isolated from the arteries. Samples of intact arteries and isolated elastin were prepared from porcine aortas and glycated. The mechanical response of all samples was completed using a uniaxial material test system. Glycation levels were measured using ELISA. A confocal microscope was used to image differences in the structure of the glycated and untreated elastin fibers. We found that, under the conditions used in this study, glycation led to decreased stiffness of elastin isolated from arteries, which was associated with a thinning of elastin fibers as imaged by confocal microscopy. We observed no effect of glycation on collagen fibers under our treatment conditions. These results suggest that glycation leads to weakening of the elastin component of arteries that could contribute to vascular defects seen in diabetes and aging. Prevention of glycation reactions may be an important consideration for vascular health later in life. © 2013 Wiley Periodicals, Inc.

Smooth Muscle-Mediated Connective Tissue Remodeling in Pulmonary Hypertension

NASA Astrophysics Data System (ADS)

Mecham, Robert P.; Whitehouse, Loren A.; Wrenn, David S.; Parks, William C.; Griffin, Gail L.; Senior, Robert M.; Crouch, Edmond C.; Stenmark, Kurt R.; Voelkel, Norbert F.

1987-07-01

Abnormal accumulation of connective tissue in blood vessels contributes to alterations in vascular physiology associated with disease states such as hypertension and atherosclerosis. Elastin synthesis was studied in blood vessels from newborn calves with severe pulmonary hypertension induced by alveolar hypoxia in order to investigate the cellular stimuli that elicit changes in pulmonary arterial connective tissue production. A two- to fourfold increase in elastin production was observed in pulmonary artery tissue and medial smooth muscle cells from hypertensive calves. This stimulation of elastin production was accompanied by a corresponding increase in elastin messenger RNA consistent with regulation at the transcriptional level. Conditioned serum harvested from cultures of pulmonary artery smooth muscle cells isolated from hypertensive animals contained one or more low molecular weight elastogenic factors that stimulated the production of elastin in both fibroblasts and smooth muscle cells and altered the chemotactic responsiveness of fibroblasts to elastin peptides. These results suggest that connective tissue changes in the pulmonary vasculature in response to pulmonary hypertension are orchestrated by the medial smooth muscle cell through the generation of specific differentiation factors that alter both the secretory phenotype and responsive properties of surrounding cells.

Age estimation based on aspartic acid racemization in elastin from the yellow ligaments.

PubMed

Ritz-Timme, S; Laumeier, I; Collins, M

2003-04-01

The yellow ligaments of the spine are characterized by an exceptionally high content of elastin, a protein with a proved longevity in several human tissues. This unique biochemical composition suggested a suitability of yellow ligaments for age estimation based on aspartic acid racemization (AAR), which was tested by determination of AAR in total tissue specimens and in purified elastin from yellow ligaments of individuals of known age. AAR was found to increase with age in both sample sets. The purified elastin samples exhibited a much faster kinetics than the total tissue, with ca. 3.7-4.6-fold higher apparent rates. The relationship between AAR and age was much closer in the purified elastin samples ( r=0.96-0.99) and it can therefore be used as a basis for biochemical age estimation. The analysis of total tissue samples cannot be recommended since the AAR values can be strongly influenced even by slight, histologically non-detectable variations in the collagen content. Age estimation based on AAR in purified elastin from yellow ligaments may be a valuable additional tool in the identification of unidentified cadavers, especially in cases where other methods cannot be applied (e.g. no available teeth, body parts).

Elastin-PLGA hybrid electrospun nanofiber scaffolds for salivary epithelial cell self-organization and polarization.

PubMed

Foraida, Zahraa I; Kamaldinov, Tim; Nelson, Deirdre A; Larsen, Melinda; Castracane, James

2017-10-15

Development of electrospun nanofibers that mimic the structural, mechanical and biochemical properties of natural extracellular matrices (ECMs) is a promising approach for tissue regeneration. Electrospun fibers of synthetic polymers partially mimic the topography of the ECM, however, their high stiffness, poor hydrophilicity and lack of in vivo-like biochemical cues is not optimal for epithelial cell self-organization and function. In search of a biomimetic scaffold for salivary gland tissue regeneration, we investigated the potential of elastin, an ECM protein, to generate elastin hybrid nanofibers that have favorable physical and biochemical properties for regeneration of the salivary glands. Elastin was introduced to our previously developed poly-lactic-co-glycolic acid (PLGA) nanofiber scaffolds by two methods, blend electrospinning (EP-blend) and covalent conjugation (EP-covalent). Both methods for elastin incorporation into the nanofibers improved the wettability of the scaffolds while only blend electrospinning of elastin-PLGA nanofibers and not surface conjugation of elastin to PLGA fibers, conferred increased elasticity to the nanofibers measured by Young's modulus. After two days, only the blend electrospun nanofiber scaffolds facilitated epithelial cell self-organization into cell clusters, assessed with nuclear area and nearest neighbor distance measurements, leading to the apicobasal polarization of salivary gland epithelial cells after six days, which is vital for cell function. This study suggests that elastin electrospun nanofiber scaffolds have potential application in regenerative therapies for salivary glands and other epithelial organs. Regenerating the salivary glands by mimicking the extracellular matrix (ECM) is a promising approach for long term treatment of salivary gland damage. Despite their topographic similarity to the ECM, electrospun fibers of synthetic polymers lack the biochemical complexity, elasticity and hydrophilicity of the ECM. Elastin is an ECM protein abundant in the salivary glands and responsible for tissue elasticity. Although it's widely used for tissue regeneration of other organs, little is known about its utility in regenerating the salivary tissue. This study describes the use of elastin to improve the elasticity, hydrophilicity and biochemical complexity of synthetic nanofibers and its potential in directing in vivo-like organization of epithelial salivary cells which helps the design of efficient salivary gland regeneration scaffolds. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Matrix Metalloproteinase 9 (MMP-9) Regulates Vein Wall Biomechanics in Murine Thrombus Resolution

PubMed Central

Nguyen, Khanh P.; McGilvray, Kirk C.; Puttlitz, Christian M.; Mukhopadhyay, Subhradip; Chabasse, Christine; Sarkar, Rajabrata

2015-01-01

Objective Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9), a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall. Methods and Results The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice. Conclusions MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution. PMID:26406902

Fingerprinting Desmosine-Containing Elastin Peptides

NASA Astrophysics Data System (ADS)

Schräder, Christoph U.; Heinz, Andrea; Majovsky, Petra; Schmelzer, Christian E. H.

2015-05-01

Elastin is a vital protein of the extracellular matrix of jawed vertebrates and provides elasticity to numerous tissues. It is secreted in the form of its soluble precursor tropoelastin, which is subsequently cross-linked in the course of the elastic fiber assembly. The process involves the formation of the two tetrafunctional amino acids desmosine (DES) and isodesmosine (IDES), which are unique to elastin. The resulting high degree of cross-linking confers remarkable properties, including mechanical integrity, insolubility, and long-term stability to the protein. These characteristics hinder the structural elucidation of mature elastin. However, MS2 data of linear and cross-linked peptides released by proteolysis can provide indirect insights into the structure of elastin. In this study, we performed energy-resolved collision-induced dissociation experiments of DES, IDES, their derivatives, and DES-/IDES-containing peptides to determine characteristic product ions. It was found that all investigated compounds yielded the same product ion clusters at elevated collision energies. Elemental composition determination using the exact masses of these ions revealed molecular formulas of the type CxHyN, suggesting that the pyridinium core of DES/IDES remains intact even at relatively high collision energies. The finding of these specific product ions enabled the development of a similarity-based scoring algorithm that was successfully applied on LC-MS/MS data of bovine elastin digests for the identification of DES-/IDES-cross-linked peptides. This approach facilitates the straightforward investigation of native cross-links in elastin.

Fingerprinting desmosine-containing elastin peptides.

PubMed

Schräder, Christoph U; Heinz, Andrea; Majovsky, Petra; Schmelzer, Christian E H

2015-05-01

Elastin is a vital protein of the extracellular matrix of jawed vertebrates and provides elasticity to numerous tissues. It is secreted in the form of its soluble precursor tropoelastin, which is subsequently cross-linked in the course of the elastic fiber assembly. The process involves the formation of the two tetrafunctional amino acids desmosine (DES) and isodesmosine (IDES), which are unique to elastin. The resulting high degree of cross-linking confers remarkable properties, including mechanical integrity, insolubility, and long-term stability to the protein. These characteristics hinder the structural elucidation of mature elastin. However, MS(2) data of linear and cross-linked peptides released by proteolysis can provide indirect insights into the structure of elastin. In this study, we performed energy-resolved collision-induced dissociation experiments of DES, IDES, their derivatives, and DES-/IDES-containing peptides to determine characteristic product ions. It was found that all investigated compounds yielded the same product ion clusters at elevated collision energies. Elemental composition determination using the exact masses of these ions revealed molecular formulas of the type CxHyN, suggesting that the pyridinium core of DES/IDES remains intact even at relatively high collision energies. The finding of these specific product ions enabled the development of a similarity-based scoring algorithm that was successfully applied on LC-MS/MS data of bovine elastin digests for the identification of DES-/IDES-cross-linked peptides. This approach facilitates the straightforward investigation of native cross-links in elastin.

Development of short and highly potent self-assembling elastin-derived pentapeptide repeats containing aromatic amino acid residues.

PubMed

Taniguchi, Suguru; Watanabe, Noriko; Nose, Takeru; Maeda, Iori

2016-01-01

Tropoelastin is the primary component of elastin, which forms the elastic fibers that make up connective tissues. The hydrophobic domains of tropoelastin are thought to mediate the self-assembly of elastin into fibers, and the temperature-mediated self-assembly (coacervation) of one such repetitive peptide sequence (VPGVG) has been utilized in various bio-applications. To elucidate a mechanism for coacervation activity enhancement and to develop more potent coacervatable elastin-derived peptides, we synthesized two series of peptide analogs containing an aromatic amino acid, Trp or Tyr, in addition to Phe-containing analogs and tested their functional characteristics. Thus, position 1 of the hydrophobic pentapeptide repeat of elastin (X(1)P(2)G(3)V(4)G(5)) was substituted by Trp or Tyr. Eventually, we acquired a novel, short Trp-containing elastin-derived peptide analog (WPGVG)3 with potent coacervation ability. From the results obtained during this process, we determined the importance of aromaticity and hydrophobicity for the coacervation potency of elastin-derived peptide analogs. Generally, however, the production of long-chain synthetic polypeptides in quantities sufficient for commercial use remain cost-prohibitive. Therefore, the identification of (WPGVG)3, which is a 15-mer short peptide consisting simply of five natural amino acids and shows temperature-dependent self-assembly activity, might serve as a foundation for the development of various kinds of biomaterials. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

The changes in crosslink contents in tissues after formalin fixation.

PubMed

Abe, Masashi; Takahashi, Masaaki; Horiuchi, Kentaro; Nagano, Akira

2003-07-01

The aim of this study was to detect crosslinks of collagen and elastin in formalin-fixed tissue, to perform quantification of these crosslinks, and to investigate the effects of formalin fixation on crosslink contents in human yellow ligament and cartilage. Pyridinoline (Pyr) is a stable and nonreducible crosslink of collagen. Pentosidine (Pen) is a senescent crosslink formed between arginine and lysine in matrix proteins, including collagen. Desmosine (Des) and its isomer isodesmosine (Isodes) are crosslinks specifically found in elastin. It is useful to measure crosslink contents of collagen and elastin as a way of investigating the properties of various tissues or their pathological changes. If it is possible to evaluate crosslinks of collagen and elastin in formalin-fixed tissues, we can investigate crosslinks in a wide variety of tissues. We used HPLC to compare the concentrations of Pyr, Pen, Des, and Isodes in the formalin-fixed tissues with their concentrations in the frozen tissues. Pyr and Pen were detected in both the formalin-fixed yellow ligament and the cartilage, and their concentrations were not significantly affected by or related to the duration of formalin fixation. Des and Isodes were detected in the formalin-fixed yellow ligament but in significantly lower amounts compared to the frozen samples. We concluded that crosslinks of collagen were preserved in formalin, but crosslinks of elastin were not preserved in it. The reason for this might be that formalin did not fix elastin tissues sufficiently or it destroyed, masked, or altered elastin crosslinks.

Chronic antihypertensive treatment improves pulse pressure but not large artery mechanics in a mouse model of congenital vascular stiffness

PubMed Central

Halabi, Carmen M.; Broekelmann, Thomas J.; Knutsen, Russell H.; Ye, Li; Mecham, Robert P.

2015-01-01

Increased arterial stiffness is a common characteristic of humans with Williams-Beuren syndrome and mouse models of elastin insufficiency. Arterial stiffness is associated with multiple negative cardiovascular outcomes, including myocardial infarction, stroke, and sudden death. Therefore, identifying therapeutic interventions that improve arterial stiffness in response to changes in elastin levels is of vital importance. The goal of this study was to determine the effect of chronic pharmacologic therapy with different classes of antihypertensive medications on arterial stiffness in elastin insufficiency. Elastin-insufficient mice 4–6 wk of age and wild-type littermates were subcutaneously implanted with osmotic micropumps delivering a continuous dose of one of the following: vehicle, losartan, nicardipine, or propranolol for 8 wk. At the end of treatment period, arterial blood pressure and large artery compliance and remodeling were assessed. Our results show that losartan and nicardipine treatment lowered blood pressure and pulse pressure in elastin-insufficient mice. Elastin and collagen content of abdominal aortas as well as ascending aorta and carotid artery biomechanics were not affected by any of the drug treatments in either genotype. By reducing pulse pressure and shifting the working pressure range of an artery to a more compliant region of the pressure-diameter curve, antihypertensive medications may mitigate the consequences of arterial stiffness, an effect that is drug class independent. These data emphasize the importance of early recognition and long-term management of hypertension in Williams-Beuren syndrome and elastin insufficiency. PMID:26232234

Congenital heart defects in Williams syndrome.

PubMed

Yuan, Shi-Min

2017-01-01

Yuan SM. Congenital heart defects in Williams syndrome. Turk J Pediatr 2017; 59: 225-232. Williams syndrome (WS), also known as Williams-Beuren syndrome, is a rare genetic disorder involving multiple systems including the circulatory system. However, the etiologies of the associated congenital heart defects in WS patients have not been sufficiently elucidated and represent therapeutic challenges. The typical congenital heart defects in WS were supravalvar aortic stenosis, pulmonary stenosis (both valvular and peripheral), aortic coarctation and mitral valvar prolapse. The atypical cardiovascular anomalies include tetralogy of Fallot, atrial septal defects, aortic and mitral valvular insufficiencies, bicuspid aortic valves, ventricular septal defects, total anomalous pulmonary venous return, double chambered right ventricle, Ebstein anomaly and arterial anomalies. Deletion of the elastin gene on chromosome 7q11.23 leads to deficiency or abnormal deposition of elastin during cardiovascular development, thereby leading to widespread cardiovascular abnormalities in WS. In this article, the distribution, treatment and surgical outcomes of typical and atypical cardiac defects in WS are discussed.

Genetically engineered nanocarriers for drug delivery.

PubMed

Shi, Pu; Gustafson, Joshua A; MacKay, J Andrew

2014-01-01

Cytotoxicity, low water solubility, rapid clearance from circulation, and off-target side-effects are common drawbacks of conventional small-molecule drugs. To overcome these shortcomings, many multifunctional nanocarriers have been proposed to enhance drug delivery. In concept, multifunctional nanoparticles might carry multiple agents, control release rate, biodegrade, and utilize target-mediated drug delivery; however, the design of these particles presents many challenges at the stage of pharmaceutical development. An emerging solution to improve control over these particles is to turn to genetic engineering. Genetically engineered nanocarriers are precisely controlled in size and structure and can provide specific control over sites for chemical attachment of drugs. Genetically engineered drug carriers that assemble nanostructures including nanoparticles and nanofibers can be polymeric or non-polymeric. This review summarizes the recent development of applications in drug and gene delivery utilizing nanostructures of polymeric genetically engineered drug carriers such as elastin-like polypeptides, silk-like polypeptides, and silk-elastin-like protein polymers, and non-polymeric genetically engineered drug carriers such as vault proteins and viral proteins.

Genetically engineered nanocarriers for drug delivery

PubMed Central

Shi, Pu; Gustafson, Joshua A; MacKay, J Andrew

2014-01-01

Cytotoxicity, low water solubility, rapid clearance from circulation, and off-target side-effects are common drawbacks of conventional small-molecule drugs. To overcome these shortcomings, many multifunctional nanocarriers have been proposed to enhance drug delivery. In concept, multifunctional nanoparticles might carry multiple agents, control release rate, biodegrade, and utilize target-mediated drug delivery; however, the design of these particles presents many challenges at the stage of pharmaceutical development. An emerging solution to improve control over these particles is to turn to genetic engineering. Genetically engineered nanocarriers are precisely controlled in size and structure and can provide specific control over sites for chemical attachment of drugs. Genetically engineered drug carriers that assemble nanostructures including nanoparticles and nanofibers can be polymeric or non-polymeric. This review summarizes the recent development of applications in drug and gene delivery utilizing nanostructures of polymeric genetically engineered drug carriers such as elastin-like polypeptides, silk-like polypeptides, and silk-elastin-like protein polymers, and non-polymeric genetically engineered drug carriers such as vault proteins and viral proteins. PMID:24741309

The Effect of Conditioned Media of Adipose-Derived Stem Cells on Wound Healing after Ablative Fractional Carbon Dioxide Laser Resurfacing

PubMed Central

Zhou, Bing-Rong; Xu, Yang; Guo, Shi-Lei; Xu, Yan; Wang, Ying; Zhu, Fen; Wu, Di; Yin, Zhi-Qiang; Luo, Dan

2013-01-01

Objective. To evaluate the benefits of conditioned medium of Adipose-derived stem cells (ADSC-CM) on wound healing after fractional carbon dioxide laser resurfacing (FxCR) on human skin. Materials and Methods. Nineteen subjects were treated with FxCR on the bilateral inner arms. ADSC-CM was applied on FxCR site of one randomly selected arm. Transepidermal water loss (TEWL), skin color, and gross-elasticity of FxCR site on both arms were measured. Skin samples were taken by biopsy from three subjects 3 weeks after treatment for histopathological manifestations and mRNA expressions of procollagen types I and III, elastin genes were noted. Results. The index of erythema, melanin, and TEWL of the ADSC-CM-treated skin were significantly lower than those of the control side. The mRNA expression of type III procollagen in ADSC-CM-treated group at 3 weeks posttreatment was 2.6 times of that of the control group. Conclusion. Application of allograft ADSC-CM is an effective method for enhancing wound healing after FxCR, by reducing transient adverse effects such as erythema, hyperpigmentation, and increased TEWL. PMID:24381938

Vibration stimulates vocal mucosa-like matrix expression by hydrogel-encapsulated fibroblasts.

PubMed

Kutty, Jaishankar K; Webb, Ken

2010-01-01

The composition and organization of the vocal fold extracellular matrix (ECM) provide the viscoelastic mechanical properties that are required to sustain high-frequency vibration during voice production. Although vocal injury and pathology are known to produce alterations in matrix physiology, the mechanisms responsible for the development and maintenance of vocal fold ECM are poorly understood. The objective of this study was to investigate the effect of physiologically relevant vibratory stimulation on ECM gene expression and synthesis by fibroblasts encapsulated within hyaluronic acid hydrogels that approximate the viscoelastic properties of vocal mucosa. Relative to static controls, samples exposed to vibration exhibited significant increases in mRNA expression levels of HA synthase 2, decorin, fibromodulin and MMP-1, while collagen and elastin expression were relatively unchanged. Expression levels exhibited a temporal response, with maximum increases observed after 3 and 5 days of vibratory stimulation and significant downregulation observed at 10 days. Quantitative assays of matrix accumulation confirmed significant increases in sulphated glycosaminoglycans and significant decreases in collagen after 5 and 10 days of vibratory culture, relative to static controls. Cellular remodelling and hydrogel viscosity were affected by vibratory stimulation and were influenced by varying the encapsulated cell density. These results indicate that vibration is a critical epigenetic factor regulating vocal fold ECM and suggest that rapid restoration of the phonatory microenvironment may provide a basis for reducing vocal scarring, restoring native matrix composition and improving vocal quality. 2009 John Wiley & Sons, Ltd.

Mechanical, structural, and dynamical modifications of cholesterol exposed porcine aortic elastin.

PubMed

Bilici, Kubra; Morgan, Steven W; Silverstein, Moshe C; Wang, Yunjie; Sun, Hyung Jin; Zhang, Yanhang; Boutis, Gregory S

2016-11-01

Elastin is a protein of the extracellular matrix that contributes significantly to the elasticity of connective tissues. In this study, we examine dynamical and structural modifications of aortic elastin exposed to cholesterol by NMR spectroscopic and relaxation methodologies. Macroscopic measurements are also presented and reveal that cholesterol treatment may cause a decrease in the stiffness of tissue. 2 H NMR relaxation techniques revealed differences between the relative populations of water that correlate with the swelling of the tissue following cholesterol exposure. 13 C magic-angle-spinning NMR spectroscopy and relaxation methods indicate that cholesterol treated aortic elastin is more mobile than control samples. Molecular dynamics simulations on a short elastin repeat VPGVG in the presence of cholesterol are used to investigate the energetic and entropic contributions to the retractive force, in comparison to the same peptide in water. Peptide stiffness is observed to reduce following cholesterol exposure due to a decrease in the entropic force. Copyright © 2016 Elsevier B.V. All rights reserved.

Small leucine-rich repeat proteoglycans associated with mature insoluble elastin serve as binding sites for galectins.

PubMed

Itoh, Aiko; Nonaka, Yasuhiro; Ogawa, Takashi; Nakamura, Takanori; Nishi, Nozomu

2017-11-01

We previously reported that galectin-9 (Gal-9), an immunomodulatory animal lectin, could bind to insoluble collagen preparations and exerted direct cytocidal effects on immune cells. In the present study, we found that mature insoluble elastin is capable of binding Gal-9 and other members of the human galectin family. Lectin blot analysis of a series of commercial water-soluble elastin preparations, PES-(A) ~ PES-(E), revealed that only PES-(E) contained substances recognized by Gal-9. Gal-9-interacting substances in PES-(E) were affinity-purified, digested with trypsin and then analyzed by reversed-phase HPLC. Peptide fragments derived from five members of the small leucine-rich repeat proteoglycan family, versican, lumican, osteoglycin/mimecan, prolargin, and fibromodulin, were identified by N-terminal amino acid sequence analysis. The results indicate that Gal-9 and possibly other galectins recognize glycans attached to small leucine-rich repeat proteoglycans associated with insoluble elastin and also indicate the possibility that mature insoluble elastin serves as an extracellular reservoir for galectins.

Mechanical, Structural, and Dynamical Modifications of Cholesterol Exposed Porcine Aortic Elastin

PubMed Central

Bilici, Kubra; Morgan, Steven W.; Silverstein, Moshe C.; Wang, Yunjie; Sun, Hyung Jin; Zhang, Katherine; Boutis, Gregory S.

2016-01-01

Elastin is a protein of the extracellular matrix that contributes significantly to the elasticity of connective tissues. In this study, we examine dynamical and structural modifications of aortic elastin exposed to cholesterol by NMR spectroscopic and relaxation methodologies. Macroscopic measurements are also presented and reveal that cholesterol treatment may cause a decrease in the stiffness of tissue. 2H NMR relaxation techniques revealed differences between the relative populations of water that correlate with the swelling of the tissue following cholesterol exposure. 13C magic-angle-spinning NMR spectroscopy and relaxation methods indicate that cholesterol treated aortic elastin appears more mobile than control samples. Molecular dynamics simulations on a short elastin repeat VPGVG in the presence of cholesterol are used to investigate the energetic and entropic contributions to the retractive force, in comparison to the same peptide in water. Peptide stiffness is observed to reduce following cholesterol exposure due to a decrease in the entropic force. PMID:27648754

Thermo-responsive human α-elastin self-assembled nanoparticles for protein delivery.

PubMed

Kim, Jae Dong; Jung, Youn Jae; Woo, Chang Hee; Choi, Young Chan; Choi, Ji Suk; Cho, Yong Woo

2017-01-01

Self-assembled nanoparticles based on PEGylated human α-elastin were prepared as a potential vehicle for sustained protein delivery. The α-elastin was extracted from human adipose tissue and modified with methoxypolyethyleneglycol (mPEG) to control particle size and enhance the colloidal stability. The PEGylated human α-elastin showed sol-to-particle transition with a lower critical solution temperature (LCST) of 25°C-40°C in aqueous media. The PEGylated human α-elastin nanoparticles (PhENPs) showed a narrow size distribution with an average diameter of 330±33nm and were able to encapsulate significant amounts of insulin and bovine serum albumin (BSA) upon simple mixing at low temperature in water and subsequent heating to physiological temperature. The release profiles of insulin and BSA showed sustained release for 72h. Overall, the thermo-responsive self-assembled PhENPs provide a useful tool for a range of protein delivery and tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

The coupled bio-chemo-electro-mechanical behavior of glucose exposed arterial elastin

NASA Astrophysics Data System (ADS)

Zhang, Yanhang; Li, Jiangyu; Boutis, Gregory S.

2017-04-01

Elastin, the principle protein component of the elastic fiber, is a critical extracellular matrix (ECM) component of the arterial wall providing structural resilience and biological signaling essential in vascular morphogenesis and maintenance of mechanical homeostasis. Pathogenesis of many cardiovascular diseases have been associated with alterations of elastin. As a long-lived ECM protein that is deposited and organized before adulthood, elastic fibers can suffer from cumulative effects of biochemical exposure encountered during aging and/or disease, which greatly compromise their mechanical function. This review article covers findings from recent studies of the mechanical and structural contribution of elastin to vascular function, and the effects of biochemical degradation. Results from diverse experimental methods including tissue-level mechanical characterization, fiber-level nonlinear optical imaging, piezoelectric force microscopy, and nuclear magnetic resonance are reviewed. The intriguing coupled bio-chemo-electro-mechanical behavior of elastin calls for a multi-scale and multi-physical understanding of ECM mechanics and mechanobiology in vascular remodeling.

Lineage Analysis in Pulmonary Arterial Hypertension

DTIC Science & Technology

2013-06-01

monocrotaline pyrrole . The fate of lacZ-expressing cells will be correlated with immunofluorescent staining of endothelial marker CD31, mesenchymal marker...A) Pilot study: Time course of development of pulmonary hypertension in pneumonectomized mice injected with monocrotaline pyrrole (P/MCTP, n = 4... pyrrole . A, B) Normal muscular pulmonary artery (PA) adjacent to bronchiole (Br) A) hematoxylin and eosin stain (H&E), B) elastin-van Gieson stain (EVG

Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

NASA Astrophysics Data System (ADS)

Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

2004-05-01

Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

Aspartic acid racemisation in purified elastin from arteries as basis for age estimation.

PubMed

Dobberstein, R C; Tung, S-M; Ritz-Timme, S

2010-07-01

Aspartic acid racemisation (AAR) results in an age-dependent accumulation of D: -aspartic acid in durable human proteins and can be used as a basis for age estimation. Routinely, age estimation based on AAR is performed by analysis of dentine. However, in forensic practise, teeth are not always available. Non-dental tissues for age estimation may be suitable for age estimation based on AAR if they contain durable proteins that can be purified and analysed. Elastin is such a durable protein. To clarify if purified elastin from arteries is a suitable sample for biochemical age estimation, AAR was determined in purified elastin from arteries from individuals of known age (n = 68 individuals, including n = 15 putrefied corpses), considering the influence of different stages of atherosclerosis and putrefaction on the AAR values. AAR was found to increase with age. The relationship between AAR and age was good enough to serve as basis for age estimation, but worse than known from dentinal proteins. Intravital and post-mortem degradation of elastin may have a moderate effect on the AAR values. Age estimation based on AAR in purified elastin from arteries may be a valuable additional tool in the identification of unidentified cadavers, especially in cases where other methods cannot be applied (e.g., no available teeth and body parts).

Prophylactic effects of elastin peptide derived from the bulbus arteriosus of fish on vascular dysfunction in spontaneously hypertensive rats.

PubMed

Takemori, Kumiko; Yamamoto, Ei; Ito, Hiroyuki; Kometani, Takashi

2015-01-01

To determine the prophylactic effects of an elastin peptide derived from the bulbus arteriosus of bonitos and prolylglycine (PG), a degradation product of elastin peptide, on vascular dysfunction in spontaneously hypertensive rats (SHRs). Male 15-week-old SHR/Izm rats were fed without (control group) or with elastin peptide (1 g/kg body weight) for 5 weeks (EP group), or were infused via an osmotic mini-pump for 4 weeks with PG (PG group) or saline (control group). Using thoracic aortas, we assessed endothelial changes by scanning electron microscopy. Vascular reactivity (contraction and relaxation) and pressure-induced distension was compared. mRNA production levels of endothelial nitric oxide synthase (eNOS) and intercellular adhesion molecule-1 (ICAM-1) were investigated by real-time-polymerase chain reaction. Aortas of the EP group displayed limited endothelial damage compared with that in the control group. Under treatment of SHRs with elastin peptide, the effect of phenylephrine returned closer to the normal level observed in normotensive Wistar-Kyoto (WKY/Izm) rats. mRNA production of eNOS (but not ICAM-1) was greater in the EP group than in the control group. Endothelial damage was suppressed and pressure-induced vascular distension was greater in the PG group than in the corresponding control group. These results suggest that elastin peptide from bonitos elicits prophylactic affects hypertension-associated vascular dysfunction by targeting the eNOS signaling pathway. PG may be a key mediator of the beneficial effects of elastin peptide. Copyright © 2014 Elsevier Inc. All rights reserved.

Design of an elastin-layered dermal regeneration template.

PubMed

Mithieux, Suzanne M; Weiss, Anthony S

2017-04-01

We demonstrate a novel approach for the production of tunable quantities of elastic fibers. We also show that exogenous tropoelastin is rate-limiting for elastin synthesis regardless of the age of the dermal fibroblast donor. Additionally, we provide a strategy to further enhance synthesis by older cells through the application of conditioned media. We show that this approach delivers an elastin layer on one side of the leading dermal repair template for contact with the deep dermis in order to deliver prefabricated elastic fibers to a physiologically appropriate site during subsequent surgery. This system is attractive because it provides for the first time a viable path for sufficient, histologically detectable levels of patient elastin into full-thickness wound sites that have until now lacked this elastic underlayer. The scars of full thickness wounds typically lack elasticity. Elastin is essential for skin elasticity and is enriched in the deep dermis. This paper is significant because it shows that: (1) we can generate elastic fibers in tunable quantities, (2) tropoelastin is the rate-limiting component in elastin synthesis in vitro, (3) we can generate elastin fibers regardless of donor age, (4) we describe a novel approach to further increase the numbers and thickness of elastic fibers for older donors, (5) we improve on Integra Dermal Regeneration Template and generate a new hybrid biomaterial intended to subsequently surgically deliver these elastic fibers, (6) the elastic fiber layer is presented on the side of Integra that is intended for delivery into its physiologically appropriate site i.e. the deep dermis. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A fiber-based constitutive model predicts changes in amount and organization of matrix proteins with development and disease in the mouse aorta

PubMed Central

Cheng, Jeffrey K.; Stoilov, Ivan; Mecham, Robert P.

2013-01-01

Decreased elastin in mice (Eln+/−) yields a functioning vascular system with elevated blood pressure and increased arterial stiffness that is morphologically distinct from wild-type mice (WT). Yet, function is retained enough that there is no appreciable effect on life span and some mechanical properties are maintained constant. It is not understood how the mouse modifies the normal developmental process to produce a functioning vascular system despite a deficiency in elastin. To quantify changes in mechanical properties, we have applied a fiber-based constitutive model to mechanical data from the ascending aorta during postnatal development of WT and Eln+/− mice. Results indicate that the fiber-based constitutive model is capable of distinguishing elastin amounts and identifying trends during development. We observe an increase in predicted circumferential stress contribution from elastin with age, which correlates with increased elastin amounts from protein quantification data. The model also predicts changes in the unloaded collagen fiber orientation with age, which must be verified in future work. In Eln+/− mice, elastin amounts are decreased at each age, along with the predicted circumferential stress contribution of elastin. Collagen amounts in Eln+/− aorta are comparable to WT, but the predicted circumferential stress contribution of collagen is increased. This may be due to altered organization or structure of the collagen fibers. Relating quantifiable changes in arterial mechanics with changes in extracellular matrix (ECM) protein amounts will help in understanding developmental remodeling and in producing treatments for human diseases affecting ECM proteins. PMID:22790326

Chronic antihypertensive treatment improves pulse pressure but not large artery mechanics in a mouse model of congenital vascular stiffness.

PubMed

Halabi, Carmen M; Broekelmann, Thomas J; Knutsen, Russell H; Ye, Li; Mecham, Robert P; Kozel, Beth A

2015-09-01

Increased arterial stiffness is a common characteristic of humans with Williams-Beuren syndrome and mouse models of elastin insufficiency. Arterial stiffness is associated with multiple negative cardiovascular outcomes, including myocardial infarction, stroke, and sudden death. Therefore, identifying therapeutic interventions that improve arterial stiffness in response to changes in elastin levels is of vital importance. The goal of this study was to determine the effect of chronic pharmacologic therapy with different classes of antihypertensive medications on arterial stiffness in elastin insufficiency. Elastin-insufficient mice 4-6 wk of age and wild-type littermates were subcutaneously implanted with osmotic micropumps delivering a continuous dose of one of the following: vehicle, losartan, nicardipine, or propranolol for 8 wk. At the end of treatment period, arterial blood pressure and large artery compliance and remodeling were assessed. Our results show that losartan and nicardipine treatment lowered blood pressure and pulse pressure in elastin-insufficient mice. Elastin and collagen content of abdominal aortas as well as ascending aorta and carotid artery biomechanics were not affected by any of the drug treatments in either genotype. By reducing pulse pressure and shifting the working pressure range of an artery to a more compliant region of the pressure-diameter curve, antihypertensive medications may mitigate the consequences of arterial stiffness, an effect that is drug class independent. These data emphasize the importance of early recognition and long-term management of hypertension in Williams-Beuren syndrome and elastin insufficiency. Copyright © 2015 the American Physiological Society.

Prostaglandin F2α receptor silencing attenuates vascular remodeling in rats with type 2 diabetes.

PubMed

Li, Ya; Han, Lu; Ding, Wen-Yuan; Ti, Yun; Li, Yi-Hui; Tang, Meng-Xiong; Wang, Zhi-Hao; Zhang, Yun; Zhang, Wei; Zhong, Ming

2015-12-01

Vascular remodeling is an important feature of diabetic macrovascular complications. The prostaglandin F2α receptor (FP), the expression of which is upregulated by insulin resistance and diabetes, is reportedly involved in myocardial remodeling. In this study, we aimed to investigate whether the FP receptor is implicated in diabetes-induced vascular remodeling. A type 2 diabetic rat model was induced through a high-fat diet and low-dose streptozotocin (STZ). Thirty-two rats were randomized into four groups: control, diabetes, diabetes treated with empty virus and diabetes treated with FP receptor-shRNA. Then, we evaluated the metabolic index, FP receptor expression and vascular remodeling. We used FP receptor gene silencing in vivo to investigate the role that the FP receptor plays in the pathophysiologic features of vascular remodeling. Diabetic rats displayed increased levels of blood glucose, cholesterol, and triglycerides, as well as severe insulin resistance and FP receptor overexpression. In addition, increased medial thickness, excessive collagen deposition and diminished elastic fibers were observed in the diabetic rats, resulting in vascular remodeling. In the FP receptor-shRNA group, the medial thickness, collagen content, elastin/collagen ratio, and collagen I/collagen III content ratio were markedly decreased. Additionally, with FP receptor gene silencing, the JNK phosphorylation level was markedly decreased. Silencing of the FP receptor exerts a protective effect on diabetes-induced vascular remodeling, thereby suggesting a new therapeutic target for vascular remodeling in diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

Arterial extracellular matrix: a mechanobiological study of the contributions and interactions of elastin and collagen.

PubMed

Chow, Ming-Jay; Turcotte, Raphaël; Lin, Charles P; Zhang, Yanhang

2014-06-17

The complex network structure of elastin and collagen extracellular matrix (ECM) forms the primary load bearing components in the arterial wall. The structural and mechanobiological interactions between elastin and collagen are important for properly functioning arteries. Here, we examined the elastin and collagen organization, realignment, and recruitment by coupling mechanical loading and multiphoton imaging. Two-photon excitation fluorescence and second harmonic generation methods were performed with a multiphoton video-rate microscope to capture real time changes to the elastin and collagen structure during biaxial deformation. Enzymatic removal of elastin was performed to assess the structural changes of the remaining collagen structure. Quantitative analysis of the structural changes to elastin and collagen was made using a combination of two-dimensional fast Fourier transform and fractal analysis, which allows for a more complete understanding of structural changes. Our study provides new quantitative evidence, to our knowledge on the sequential engagement of different arterial ECM components in response to mechanical loading. The adventitial collagen exists as large wavy bundles of fibers that exhibit fiber engagement after 20% strain. The medial collagen is engaged throughout the stretching process, and prominent elastic fiber engagement is observed up to 20% strain after which the engagement plateaus. The fiber orientation distribution functions show remarkably different changes in the ECM structure in response to mechanical loading. The medial collagen shows an evident preferred circumferential distribution, however the fiber families of adventitial collagen are obscured by their waviness at no or low mechanical strains. Collagen fibers in both layers exhibit significant realignment in response to unequal biaxial loading. The elastic fibers are much more uniformly distributed and remained relatively unchanged due to loading. Removal of elastin produces similar structural changes in collagen as mechanical loading. Our study suggests that the elastic fibers are under tension and impart an intrinsic compressive stress on the collagen. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Measurement of MMP-9 and -12 degraded elastin (ELM) provides unique information on lung tissue degradation

PubMed Central

2012-01-01

Background Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases. Methods Elastin fragments were identified by mass-spectrometry and one sequence, generated by MMP-9 and -12 (ELN-441), was selected for monoclonal antibody generation and used in the development of an ELISA. Soluble and insoluble elastin from lung was cleaved in vitro and the time-dependent release of fragments was assessed in the ELN-441 assay. The release of ELN-441 in human serum from patients with chronic obstructive pulmonary disease (COPD) (n = 10) and idiopathic pulmonary fibrosis (IPF) (n = 29) were compared to healthy matched controls (n = 11). Results The sequence ELN-441 was exclusively generated by MMP-9 and -12 and was time-dependently released from soluble lung elastin. ELN-441 levels were 287% higher in patients diagnosed with COPD (p < 0.001) and 124% higher in IPF patients (p < 0.0001) compared with controls. ELN-441 had better diagnostic value in COPD patients (AUC 97%, p = 0.001) than in IPF patients (AUC 90%, p = 0.0001). The odds ratios for differentiating controls from COPD or IPF were 24 [2.06–280] for COPD and 50 [2.64–934] for IPF. Conclusions MMP-9 and -12 time-dependently released the ELN-441 epitope from elastin. This fragment was elevated in serum from patients with the lung diseases IPF and COPD, however these data needs to be validated in larger clinical settings. PMID:22818364

Reduction of facial wrinkles by hydrolyzed water-soluble egg membrane associated with reduction of free radical stress and support of matrix production by dermal fibroblasts

PubMed Central

Jensen, Gitte S; Shah, Bijal; Holtz, Robert; Patel, Ashok; Lo, Donald C

2016-01-01

Objective The aim of this study was to evaluate the effects of water-soluble egg membrane (WSEM) on wrinkle reduction in a clinical pilot study and to elucidate specific mechanisms of action using primary human immune and dermal cell-based bioassays. Methods To evaluate the effects of topical application of WSEM (8%) on human skin, an open-label 8-week study was performed involving 20 healthy females between the age of 45 years and 65 years. High-resolution photography and digital analysis were used to evaluate the wrinkle depth in the facial skin areas beside the eye (crow’s feet). WSEM was tested for total antioxidant capacity and effects on the formation of reactive oxygen species by human polymorphonuclear cells. Human keratinocytes (HaCaT cells) were used for quantitative polymerase chain reaction analysis of the antioxidant response element genes Nqo1, Gclm, Gclc, and Hmox1. Evaluation of effects on human primary dermal fibroblasts in vitro included cellular viability and production of the matrix components collagen and elastin. Results Topical use of a WSEM-containing facial cream for 8 weeks resulted in a significant reduction of wrinkle depth (P<0.05). WSEM contained antioxidants and reduced the formation of reactive oxygen species by inflammatory cells in vitro. Despite lack of a quantifiable effect on Nrf2, WSEM induced the gene expression of downstream Nqo1, Gclm, Gclc, and Hmox1 in human keratinocytes. Human dermal fibroblasts treated with WSEM produced more collagen and elastin than untreated cells or cells treated with dbcAMP control. The increase in collagen production was statistically significant (P<0.05). Conclusion The topical use of WSEM on facial skin significantly reduced the wrinkle depth. The underlying mechanisms of this effect may be related to protection from free radical damage at the cellular level and induction of several antioxidant response elements, combined with stimulation of human dermal fibroblasts to secrete high levels of matrix components. PMID:27789968

Self-Assembly of a Modular Polypeptide Based on Blocks of Silk-Mimetic and Elastin-Mimetic Sequences

DTIC Science & Technology

2002-04-01

Silk -Mimetic and Elastin-Mimetic Sequences DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following...724 © 2002 Materials Research Society N3.8 Self-Assembly of a Modular Polypeptide based on Blocks of Silk -Mimetic and Elastin- Mimetic Sequences...Chrystelle S. Cazalis, and Vincent P. Conticello* Department of Chemistry, Emory University, Atlanta, GA 30322 ABSTRACT Spider dragline silk fiber displays

Heme oxygenase-1 upregulation modulates tone and fibroelastic properties of internal anal sphincter

PubMed Central

Krishna, Chadalavada Vijay; Singh, Jagmohan; Kumar, Sumit

2014-01-01

A compromise in the internal anal sphincter (IAS) tone and fibroelastic properties (FEP) plays an important role in rectoanal incontinence. Herein, we examined the effects of heme oxygenase (HO)-1 upregulation on these IAS characteristics in young rats. We determined the effect of HO-1 upregulator hemin on HO-1 mRNA and protein expressions and on basal IAS tone and its FEP before and after HO-1 inhibitor tin protoporphyrin IX. For FEP, we determined the kinetics of the IAS smooth muscle responses, by the velocities of relaxation, and recovery of the IAS tone following 0 Ca2+ and electrical field stimulation. To characterize the underlying signal transduction for these changes, we determined the effects of hemin on RhoA-associated kinase (RhoA)/Rho kinase (ROCK) II, myosin-binding subunit of myosin light chain phosphatase 1, fibronectin, and elastin expression levels. Hemin increased HO-1 mRNA and protein similar to the increases in the basal tone, and in the FEP of the IAS. Underlying mechanisms in the IAS characteristics are associated with increases in the genetic and translational expressions of RhoA/ROCKII, and elastin. Fibronectin expression levels on the other hand were found to be decreased following HO-1 upregulation. The results of our study show that the hemin/HO-1 system regulates the tone and FEP of IAS. The hemin/HO-1 system thus provides a potential target for the development of new interventions aimed at treatment of gastrointestinal motility disorders, specifically the age-related IAS dysfunction. PMID:25035109

Influence of elastin-derived peptides on metalloprotease production in endothelial cells.

PubMed

Siemianowicz, Krzysztof; Gminski, Jan; Goss, Malgorzata; Francuz, Tomasz; Likus, Wirginia; Jurczak, Teresa; Garczorz, Wojciech

2010-11-01

Matrix metalloproteases (MMPs) are a family of zinc-dependent endopeptidases that degrade extracellular matrix proteins. MMP-1 and MMP-2 are produced by endothelial cells and are involved in specific vascular pathologies, including atherosclerosis and aortal aneurysm. One of the most important differences between these two metalloproteases is the possibility of hydrolysis of elastin and collagen type IV by MMP-2, but not by MMP-1. Elastin-derived peptides are generated as a result of the degradation of elastin fibers. The aim of our study was to compare the production of MMP-1 and MMP-2 in cultured human arterial endothelial cells derived from vascular pathologies localized at three different sites, the coronary artery, iliac artery and aorta, measured as their concentration in cell culture medium. The second aim was to evaluate the influence of κ-elastin (at concentrations 0.1, 0.4, 1.0, 2.5 or 5.0 μg/ml) on the production of the evaluated metalloproteases in three endothelial cell lines. The production of MMP-1 was statistically significantly greater in endothelial cells derived from the aorta compared to that in the endothelium obtained from the coronary and iliac arteries. There were no statistically significant differences in the production of MMP-2 among the endothelial cell lines tested. The addition of κ-elastin at all evaluated concentrations did not statistically significantly influence the concentration of MMP-1 in the cultured coronary artery endothelium. Furthermore, no statistically significant differences were observed in the cultured iliac artery endothelium. In the cultured endothelium derived from the aorta, κ-elastin at concentrations of 0.1 and 0.4 μg/ml significantly increased the amount of MMP-1.

Influence of elastin-derived peptides on metalloprotease production in endothelial cells

PubMed Central

SIEMIANOWICZ, KRZYSZTOF; GMINSKI, JAN; GOSS, MALGORZATA; FRANCUZ, TOMASZ; LIKUS, WIRGINIA; JURCZAK, TERESA; GARCZORZ, WOJCIECH

2010-01-01

Matrix metalloproteases (MMPs) are a family of zinc-dependent endopeptidases that degrade extracellular matrix proteins. MMP-1 and MMP-2 are produced by endothelial cells and are involved in specific vascular pathologies, including atherosclerosis and aortal aneurysm. One of the most important differences between these two metalloproteases is the possibility of hydrolysis of elastin and collagen type IV by MMP-2, but not by MMP-1. Elastin-derived peptides are generated as a result of the degradation of elastin fibers. The aim of our study was to compare the production of MMP-1 and MMP-2 in cultured human arterial endothelial cells derived from vascular pathologies localized at three different sites, the coronary artery, iliac artery and aorta, measured as their concentration in cell culture medium. The second aim was to evaluate the influence of κ-elastin (at concentrations 0.1, 0.4, 1.0, 2.5 or 5.0 μg/ml) on the production of the evaluated metalloproteases in three endothelial cell lines. The production of MMP-1 was statistically significantly greater in endothelial cells derived from the aorta compared to that in the endothelium obtained from the coronary and iliac arteries. There were no statistically significant differences in the production of MMP-2 among the endothelial cell lines tested. The addition of κ-elastin at all evaluated concentrations did not statistically significantly influence the concentration of MMP-1 in the cultured coronary artery endothelium. Furthermore, no statistically significant differences were observed in the cultured iliac artery endothelium. In the cultured endothelium derived from the aorta, κ-elastin at concentrations of 0.1 and 0.4 μg/ml significantly increased the amount of MMP-1. PMID:22993640

Synthetic ligands of the elastin receptor induce elastogenesis in human dermal fibroblasts via activation of their IGF-1 receptors.

PubMed

Qa'aty, Nour; Vincent, Matthew; Wang, Yanting; Wang, Andrew; Mitts, Thomas F; Hinek, Aleksander

2015-12-01

We have previously reported that a mixture of peptides obtained after chemical or enzymatic degradation of bovine elastin, induced new elastogenesis in human skin. Now, we investigated the elastogenic potential of synthetic peptides mimicking the elastin-derived, VGVAPG sequence, IGVAPG sequence that we found in the rice bran, and a similar peptide, VGVTAG that we identified in the IGF-1-binding protein-1 (IGFBP-1). We now demonstrate that treatment with each of these xGVxxG peptides (recognizable by the anti-elastin antibody), up-regulated the levels of elastin-encoding mRNA, tropoelastin protein, and the deposition of new elastic fibers in cultures of human dermal fibroblasts and in cultured explants of human skin. Importantly, we found that such induction of new elastogenesis may involve two parallel signaling pathways triggered after activation of IGF-1 receptor. In the first one, the xGVxxG peptides interact with the cell surface elastin receptor, thereby causing the downstream activation of the c-Src kinase and a consequent cross-activation of the adjacent IGF-1R, even in the absence of its principal ligand. In the second pathway their hydrophobic association with the N-terminal domain (VGVTAG) of the serum-derived IGFBP-1 induces conformational changes of this IGF-1 chaperone allowing for the release of its cargo and a consequent ligand-specific phosphorylation of IGF-1R. We present a novel, clinically relevant mechanism in which products of partial degradation of dermal elastin may stimulate production of new elastic fibers by dermal fibroblasts. Our findings particularly encourage the use of biologically safe synthetic xGVxxG peptides for regeneration of the injured or aged human skin. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Elephantiasis, elastin, and chronic wound healing: 19th century and contemporary viewpoints relevant to hypotheses concerning lymphedema, leprosy, erysipelas, and psoriasis--review and reflections.

PubMed

Ryan, T J

2009-03-01

Both wound healing and lymphedema have fibrosis of the skin in common. They also share destruction of elastin by elastases from neutrophils as a significant feature. These are not new observations, and the writings of Unna and Kaposi are recalled. The contemporary observations on elastin by Gerli and his team are discussed in the light of these much earlier opinions.

Development of Intra-Articular Drug Delivery to Alter Progression of Arthritis Following Joint Injury

DTIC Science & Technology

2012-04-01

2012Revised AnnualApril 2012 DESIGN: A novel injectable and in situ forming drug depot based on thermally-responsive elastin -like polypeptide (ELP) will... Elastin -like polypeptide, Drug Depot – technology allowing sustained release of biologically active agent , Active agents used include IL1Ra...The abstract has been removed and an appendix has been included. In brief this protocol explores the use of elastin like polypeptide (ELP) as a

Effects of solvent concentration and composition on protein dynamics: 13C MAS NMR studies of elastin in glycerol-water mixtures.

PubMed

Demuth, Dominik; Haase, Nils; Malzacher, Daniel; Vogel, Michael

2015-08-01

We use (13)C CP MAS NMR to investigate the dependence of elastin dynamics on the concentration and composition of the solvent at various temperatures. For elastin in pure glycerol, line-shape analysis shows that larger-scale fluctuations of the protein backbone require a minimum glycerol concentration of ~0.6 g/g at ambient temperature, while smaller-scale fluctuations are activated at lower solvation levels of ~0.2 g/g. Immersing elastin in various glycerol-water mixtures, we observe at room temperature that the protein mobility is higher for lower glycerol fractions in the solvent and, thus, lower solvent viscosity. When decreasing the temperature, the elastin spectra approach the line shape for the rigid protein at 245 K for all studied samples, indicating that the protein ceases to be mobile on the experimental time scale of ~10(-5) s. Our findings yield evidence for a strong coupling between elastin fluctuations and solvent dynamics and, hence, such interaction is not restricted to the case of protein-water mixtures. Spectral resolution of different carbon species reveals that the protein-solvent couplings can, however, be different for side chain and backbone units. We discuss these results against the background of the slaving model for protein dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

Structural and Functional Differences Between Porcine Aorta and Vena Cava.

PubMed

Mattson, Jeffrey M; Zhang, Yanhang

2017-07-01

Elastin and collagen fibers are the major load-bearing extracellular matrix (ECM) constituents of the vascular wall. Arteries function differently than veins in the circulatory system; however as a result from several treatment options, veins are subjected to sudden elevated arterial pressure. It is thus important to recognize the fundamental structure and function differences between a vein and an artery. Our research compared the relationship between biaxial mechanical function and ECM structure of porcine thoracic aorta and inferior vena cava. Our study suggests that aorta contains slightly more elastin than collagen due to the cyclical extensibility, but vena cava contains almost four times more collagen than elastin to maintain integrity. Furthermore, multiphoton imaging of vena cava showed longitudinally oriented elastin and circumferentially oriented collagen that is recruited at supraphysiologic stress, but low levels of strain. However in aorta, elastin is distributed uniformly, and the primarily circumferentially oriented collagen is recruited at higher levels of strain than vena cava. These structural observations support the functional finding that vena cava is highly anisotropic with the longitude being more compliant and the circumference stiffening substantially at low levels of strain. Overall, our research demonstrates that fiber distributions and recruitment should be considered in addition to relative collagen and elastin contents. Also, the importance of accounting for the structural and functional differences between arteries and veins should be taken into account when considering disease treatment options.

Elastin-derived peptides promote abdominal aortic aneurysm formation by modulating M1/M2 macrophage polarization1

PubMed Central

Dale, Matthew A; Xiong, Wanfen; Carson, Jeffrey S; Suh, Melissa K; Karpisek, Andrew D.; Meisinger, Trevor M.; Casale, George P.; Baxter, B. Timothy

2016-01-01

Abdominal aortic aneurysm (AAA) is a dynamic vascular disease characterized by inflammatory cell invasion and extracellular matrix (ECM) degradation. Damage to elastin in the ECM results in release of elastin-derived peptides (EDPs), which are chemotactic for inflammatory cells such as monocytes. Their effect on macrophage polarization is less well known. Pro-inflammatory M1 macrophages initially are recruited to sites of injury but, if their effects are prolonged, they can lead to chronic inflammation that prevents normal tissue repair. Conversely, anti-inflammatory M2 macrophages reduce inflammation and aid in wound healing. Thus, a proper M1/M2 ratio is vital for tissue homeostasis. AAA tissue reveals a high M1/M2 ratio where pro-inflammatory cells and their associated markers dominate. In the present study, in vitro treatment of bone marrow-derived macrophages with EDPs induced M1 macrophage polarization. By using C57Bl/6 mice, antibody-mediated neutralization of EDPs reduced aortic dilation, matrix metalloproteinase activity, and pro-inflammatory cytokine expression at early and late time points after aneurysm induction. Furthermore, direct manipulation of the M1/M2 balance altered aortic dilation. Injection of M2 polarized macrophages reduced aortic dilation after aneurysm induction. EDPs promoted a pro-inflammatory environment in aortic tissue by inducing M1 polarization and neutralization of EDPs attenuated aortic dilation. The M1/M2 imbalance is vital to aneurysm formation. PMID:27183603

Suppressive effects of dietary EPA-rich fish oil on the degradation of elastin fibers in the aortic wall in nicotine-administered mice.

PubMed

Kugo, Hirona; Zaima, Nobuhiro; Onozato, Megumi; Miyamoto, Chie; Hashimoto, Keisuke; Yanagimoto, Kenichi; Moriyama, Tatsuya

2017-08-01

Abdominal aortic aneurysm (AAA) is a vascular disease involving gradual dilation of the abdominal aorta. Recent studies suggest that nicotine, which is a primary component in cigarette smoke, is closely associated with the development and rupture of an AAA. Nicotine accelerates AAA development through the weakening of the vascular wall by increasing oxidative stress and matrix metalloproteinase (MMP)-2 expression. However, little is known about preventing the AAA induced by nicotine. A non-surgical means of preventing the weakening of the vascular wall before the onset of AAA by functional food factors would be a valuable option over surgery. Fish oil is a functional food that is rich in n-3 polyunsaturated fatty acids that have an anti-inflammatory effect. In this study, we evaluated the effect of dietary fish oil on the weakening of the aortic wall due to nicotine administration in a mouse model. Histological analysis showed that the dietary fish oil suppressed the degradation of elastin fibers in the nicotine-administered mice. Additionally, the dietary fish oil suppressed the protein level of MMP-12, macrophage infiltration, and the oxidative stress in the vascular wall. These results suggest that fish oil could suppress the weakening of the vascular wall by suppressing the elastin fiber degradation caused by nicotine. By suppressing the nicotine induced weakening of the vascular wall, fish oil might help prevent the development of AAA.

Progesterone and gravidity differentially regulate expression of extracellular matrix components in the pregnant rat myometrium.

PubMed

Shynlova, Oksana; Mitchell, Jennifer A; Tsampalieros, Anne; Langille, B Lowell; Lye, Stephen J

2004-04-01

Myometrial growth and remodeling during pregnancy depends on increased synthesis of interstitial matrix proteins. We hypothesize that the presence of mechanical tension in a specific hormonal environment regulates the expression of extracellular matrix (ECM) components in the uterus. Myometrial tissue was collected from pregnant rats on Gestational Days 0, 12, 15, 17, 19, 21, 22, 23 (labor), and 1 day postpartum and ECM expression was analyzed by Northern blotting. Expression of fibronectin, laminin beta2, and collagen IV mRNA was low during early gestation but increased dramatically on Day 23 during labor. Expression of fibrillar collagens (type I and III) peaked Day 19 and decreased near term. In contrast, elastin mRNA remained elevated from midgestation onward. Injection of progesterone (P4) on Days 20-23 (to maintain elevated plasma P4 levels) delayed the onset of labor, caused dramatic reductions in the levels of fibronectin and laminin mRNA, and prevented the fall of collagen III mRNA levels on Day 23. Treatment of pregnant rats with the progesterone receptor antagonist RU486 on Day 19 induced preterm labor on Day 20 and a premature increase in mRNA levels of collagen IV, fibronectin, and laminin. Analysis of the uterine tissue from unilaterally pregnant rats revealed that most of the changes in ECM gene expression occurred specifically in the gravid horn. Our results show a decrease in expression of fibrillar collagens and a coordinated temporal increase in expression of components of the basement membrane near term associated with decreased P4 and increased mechanical tension. These ECM changes contribute to myometrial growth and remodeling during late pregnancy and the preparation for the synchronized contractions of labor.

Knockdown of versican 1 blocks cigarette-induced loss of insoluble elastin in human lung fibroblasts.

PubMed

Xu, Lu-lu; Lu, Yun-tao; Zhang, Jing; Wu, Lian; Merrilees, Mervyn J; Qu, Jie-ming

2015-08-15

COPD lung is characterized by loss of alveolar elastic fibers and an increase in the chondroitin sulfate (CS) matrix proteoglycan versican V1 (V1). V1 is a known inhibitor of elastic fiber deposition and this study investigates the effects of knockdown of V1, and add-back of CS, on CCL-210 lung fibroblasts treated with cigarette smoke extract (CSE) as a model for COPD. CSE inhibited fibroblast proliferation, viability, tropoelastin synthesis, and elastin deposition, and increased V1 synthesis and secretion. V1 siRNA decreased V1 and constituent CS, did not affect tropoelastin production, but blocked the CSE-induced loss in insoluble elastin. Exogenous CS reduced insoluble elastin, even in the presence of V1 siRNA. These findings confirm that V1 and CS impair the assembly of tropoelastin monomers into insoluble fibers, and further demonstrate that specific knockdown of V1 alleviates the impaired assembly of elastin seen in cultures of pulmonary fibroblasts exposed to CSE, indicating a regulatory role for this protein in the pathophysiology of COPD. Copyright © 2015 Elsevier B.V. All rights reserved.

Matrix ageing and vascular impacts: focus on elastin fragmentation.

PubMed

Duca, Laurent; Blaise, Sébastien; Romier, Béatrice; Laffargue, Muriel; Gayral, Stéphanie; El Btaouri, Hassan; Kawecki, Charlotte; Guillot, Alexandre; Martiny, Laurent; Debelle, Laurent; Maurice, Pascal

2016-06-01

Cardiovascular diseases (CVDs) are the leading cause of death worldwide and represent a major problem of public health. Over the years, life expectancy has considerably increased throughout the world, and the prevalence of CVD is inevitably rising with the growing ageing of the population. The normal process of ageing is associated with progressive deterioration in structure and function of the vasculature, commonly called vascular ageing. At the vascular level, extracellular matrix (ECM) ageing leads to molecular alterations in long half-life proteins, such as elastin and collagen, and have critical effects on vascular diseases. This review highlights ECM alterations occurring during vascular ageing with a specific focus on elastin fragmentation and also the contribution of elastin-derived peptides (EDP) in age-related vascular complications. Moreover, current and new pharmacological strategies aiming at minimizing elastin degradation, EDP generation, and associated biological effects are discussed. These strategies may be of major relevance for preventing and/or delaying vascular ageing and its complications. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Elasticity and Inverse Temperature Transition in Elastin

DOE PAGES

Perticaroli, Stefania; Ehlers, Georg; Jalarvo, Niina; ...

2015-09-22

Structurally, elastin is protein and biomaterial that provides elasticity and resilience to a range of tissues. This work provides insights into the elastic properties of elastin and its peculiar inverse temperature transition (ITT). These features are dependent on hydration of elastin and are driven by a similar mechanism of hydrophobic collapse to an entropically favorable state. Moreover, when using neutron scattering, we quantify the changes in the geometry of molecular motions above and below the transition temperature, showing a reduction in the displacement of water-induced motions upon hydrophobic collapse at the ITT. Finally, we measured the collective vibrations of elastinmore » gels as a function of elongation, revealing no changes in the spectral features associated with local rigidity and secondary structure, in agreement with the entropic origin of elasticity.« less

Visualization of dermal alteration in skin lesions with discoid lupus erythematosus by multiphoton microscopy

NASA Astrophysics Data System (ADS)

Lin, L. H.; Yu, H. B.; Zhu, X. Q.; Zhuo, S. M.; Wang, Y. Y.; Yang, Y. H.; Chen, J. X.

2013-04-01

Discoid lupus erythematosus (DLE) is a chronic dermatological disease which lacks valid methods for early diagnosis and therapeutic monitoring. Considering the collagen and elastin disorder due to mucin deposition of DLE, multiphoton microscopy (MPM) imaging techniques were employed to obtain high-resolution collagen and elastin images from the dermis. The content and distribution of collagen and elastin were quantified to characterize the dermal pathological status of skin lesions with DLE in comparison with normal skin. Our results showed a significant difference between skin lesions with DLE and normal skin in terms of the morphological structure of collagen and elastin in the dermis, demonstrating the possibility of MPM for noninvasively tracking the pathological process of DLE even in its early stages and evaluating the therapeutic efficacy at the molecular level.

Sida rhomboidea.Roxb aqueous extract down-regulates in vivo expression of vascular cell adhesion molecules in atherogenic rats and inhibits in vitro macrophage differentiation and foam cell formation.

PubMed

Thounaojam, Menaka C; Jadeja, Ravirajsinh N; Salunke, Sunita P; Devkar, Ranjitsinh V; Ramachandran, A V

2012-10-01

The present study evaluates efficacy of Sida rhomboidea.Roxb (SR) leaves extract in ameliorating experimental atherosclerosis using in vitro and in vivo experimental models. Atherogenic (ATH) diet fed rats recorded significant increment in the serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), very LDL (VLDL), autoantibody against oxidized LDL (Ox-LDL), markers of LDL oxidation and decrement in high-density lipoprotein (HDL) along with increment in aortic TC and TG. The ex vivo LDL oxidation assay revealed an increased susceptibility of LDL isolated from ATH rats to undergo copper mediated oxidation. These set of changes were minimized by simultaneous co-supplementation of SR extract to ATH diet fed rats. Histopathology of aorta and immunolocalization studies recorded pronounced atheromatous plaque formation, vascular calcification, significant elastin derangements and higher expression of macrophage surface marker (F4/80), vascular cell adhesion molecule-1 (VCAM-1) and p-selectin in ATH rats. Whereas, ATH+SR rats depicted minimal evidence of atheromatous plaque formation, calcium deposition, distortion/defragmentation of elastin and accumulation of macrophages along with lowered expression of VCAM-1 and P-selectin compared to ATH rats. Further, monocyte to macrophage differentiation and in vitro foam cell formation were significantly attenuated in presence of SR extract. In conclusion, SR extract has the potency of controlling experimental atherosclerosis and can be used as promising herbal supplement in combating atherosclerosis.

Elastin Based Cell-laden Injectable Hydrogels with Tunable Gelation, Mechanical and Biodegradation Properties

PubMed Central

Fathi, Ali; Mithieux, Suzanne M.; Wei, Hua; Chrzanowski, Wojciech; Valtchev, Peter; Weiss, Anthony S.; Dehghani, Fariba

2015-01-01

Injectable hydrogels made from extracellular matrix proteins such as elastin show great promise for various biomedical applications. Use of cytotoxic reagents, fixed gelling behavior, and lack of mechanical strength in these hydrogels are the main associated drawbacks. The aim of this study was to develop highly cytocompatible and injectable elastin-based hydrogels with alterable gelation characteristics, favorable mechanical properties and structural stability for load bearing applications. A thermoresponsive copolymer, poly(N-isopropylacrylamide-co-polylactide-2-hydroxyethyl methacrylate-co-oligo(ethylene glycol)monomethyl ether methacrylate, was functionalized with succinimide ester groups by incorporating N-acryloxysuccinimide monomer. These ester groups were exploited to covalently bond this polymer, denoted as PNPHO, to different proteins with primary amine groups such as α-elastin in aqueous media. The incorporation of elastin through covalent bond formation with PNPHO promotes the structural stability, mechanical properties and live cell proliferation within the structure of hydrogels. Our results demonstrated that elastin-co-PNPHO solutions were injectable through fine gauge needles and converted to hydrogels in situ at 37 °C in the absence of any crosslinking reagent. By altering PNPHO content, the gelling time of these hydrogels can be finely tuned within the range of 2 to 15 min to ensure compatibility with surgical requirements. In addition, these hydrogels exhibited compression moduli in the range of 40 to 145 kPa, which are substantially higher than those of previously developed elastin-based hydrogels. These hydrogels were highly stable in the physiological environment with the evidence of 10 wt% mass loss in 30 days of incubation in a simulated environment. This class of hydrogels is in vivo bioabsorbable due to the gradual increase of the lower critical solution temperature of the copolymer to above 37 °C due to the cleavage of polylactide from the PNPHO copolymer. Moreover, our results demonstrated that more than 80% of cells encapsulated in these hydrogels remained viable, and the number of encapsulated cells increased for at least 5 days. These unique properties mark elastin-co-PNHPO hydrogels as favorable candidates for a broad range of tissue engineering applications. PMID:24731705

A novel microsatellite DNA marker at locus D7S1870 detects hemizygosity in 75% of patients with Williams syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert-Dussardier, B.; Bonneau, D.; Gigarel, N.

1995-02-01

Williams syndrome (WS) is a predominantly sporadic developmental disorder characterized by dysmorphic facial features, infantile hypercalcemia, premature aging of skin, mental retardation and gregarious personality. Supravalvular aortic stenosis (SVAS) and other vascular diseases caused by the narrowing of large elastic arteries are present in almost 80% of cases. Recently, hemizygosity at the elastin locus has been shown in sporadic WS, suggesting that this disease is caused by deletions encompassing the elastin gene on chromosome 7q11.23. Taking advantage of a large series of sporadic WS (27 cases), we have explored the potential application of novel microsatellite DNA markers in the rapidmore » detection of hemizygosity in WS. We report here a highly informative marker at locus D7S1870, which detected failure of parental inheritance in almost 75% of cases of WS in our series. This marker can be regarded therefore as a reliable and useful diagnostic tool in suspected cases of WS as well as in complicated forms of supravalvular aortic stenosis. 10 refs., 2 figs.« less

Changes in cell wall properties coincide with overexpression of extensin fusion proteins in suspension cultured tobacco cells.

PubMed

Tan, Li; Pu, Yunqiao; Pattathil, Sivakumar; Avci, Utku; Qian, Jin; Arter, Allison; Chen, Liwei; Hahn, Michael G; Ragauskas, Arthur J; Kieliszewski, Marcia J

2014-01-01

Extensins are one subfamily of the cell wall hydroxyproline-rich glycoproteins, containing characteristic SerHyp4 glycosylation motifs and intermolecular cross-linking motifs such as the TyrXaaTyr sequence. Extensins are believed to form a cross-linked network in the plant cell wall through the tyrosine-derivatives isodityrosine, pulcherosine, and di-isodityrosine. Overexpression of three synthetic genes encoding different elastin-arabinogalactan protein-extensin hybrids in tobacco suspension cultured cells yielded novel cross-linking glycoproteins that shared features of the extensins, arabinogalactan proteins and elastin. The cell wall properties of the three transgenic cell lines were all changed, but in different ways. One transgenic cell line showed decreased cellulose crystallinity and increased wall xyloglucan content; the second transgenic cell line contained dramatically increased hydration capacity and notably increased cell wall biomass, increased di-isodityrosine, and increased protein content; the third transgenic cell line displayed wall phenotypes similar to wild type cells, except changed xyloglucan epitope extractability. These data indicate that overexpression of modified extensins may be a route to engineer plants for bioenergy and biomaterial production.

Small Artery Elastin Distribution and Architecture-Focus on Three Dimensional Organization.

PubMed

Hill, Michael A; Nourian, Zahra; Ho, I-Lin; Clifford, Philip S; Martinez-Lemus, Luis; Meininger, Gerald A

2016-11-01

The distribution of ECM proteins within the walls of resistance vessels is complex both in variety of proteins and structural arrangement. In particular, elastin exists as discrete fibers varying in orientation across the adventitia and media as well as often resembling a sheet-like structure in the case of the IEL. Adding to the complexity is the tissue heterogeneity that exists in these structural arrangements. For example, small intracranial cerebral arteries lack adventitial elastin while similar sized arteries from skeletal muscle and intestinal mesentery exhibit a complex adventitial network of elastin fibers. With regard to the IEL, several vascular beds exhibit an elastin sheet with punctate holes/fenestrae while in others the IEL is discontinuous and fibrous in appearance. Importantly, these structural patterns likely sub-serve specific functional properties, including mechanosensing, control of external forces, mechanical properties of the vascular wall, cellular positioning, and communication between cells. Of further significance, these processes are altered in vascular disorders such as hypertension and diabetes mellitus where there is modification of ECM. This brief report focuses on the three-dimensional wall structure of small arteries and considers possible implications with regard to mechanosensing under physiological and pathophysiological conditions. © 2016 John Wiley & Sons Ltd.

Processing and characterization of α-elastin electrospun membranes

NASA Astrophysics Data System (ADS)

Araujo, J.; Padrão, J.; Silva, J. P.; Dourado, F.; Correia, D. M.; Botelho, G.; Gomez Ribelles, J. L.; Lanceros-Méndez, S.; Sencadas, V.

2014-06-01

Elastin isolated from fresh bovine ligaments was dissolved in a mixture of 1,1,1,3,3,3-Hexafluoro-2-propanol and water were electrospun into fiber membranes under different processing conditions. Fiber mats of randomly and aligned fibers were obtained with fixed and rotating ground collectors and fibrils were composed by thin ribbons whose width depends on electrospinning conditions; fibrils with 721 nm up to 2.12 μm width were achieved. After cross-linking with glutaraldehyde, α-elastin can uptake as much as 1700 % of PBS solution and a slight increase on fiber thickness was observed. The glass transition temperature of electrospun fiber mats was found to occur at ˜80 °C. Moreover, α-Elastin showed to be a perfect elastomeric material, and no mechanical hysteresis was found in cycle mechanical measurements. The elastic modulus obtained for random and aligned fibers mats in a PBS solution was 330±10 kPa and 732±165 kPa, respectively. Finally, the electrospinning and cross-linking process does not inhibit MC-3T3-E1 cell adhesion. Cell culture results showed good cell adhesion and proliferation in the cross-linked elastin fiber mats.

Synthetic serine elastase inhibitor reduces cigarette smoke-induced emphysema in guinea pigs.

PubMed

Wright, Joanne L; Farmer, Stephen G; Churg, Andrew

2002-10-01

To test whether a serine elastase inhibitor could prevent or reduce emphysema, we exposed guinea pigs to cigarette smoke acutely, or daily for 6 months, and treated some animals with the neutrophil elastase inhibitor ZD0892. Acute smoke exposure increased lavage neutrophils and increased desmosine and hydroxyproline, measures of elastin and collagen breakdown; all these measures were reduced by ZD0892. Long-term smoke exposure produced emphysema and increases in lavage neutrophils, desmosine, hydroxyproline, and plasma tumor necrosis factor alpha (TNF-alpha). ZD0892 treatment returned lavage neutrophils, desmosine, and hydroxyproline levels to control values, and decreased airspace enlargement by 45% and TNF-alpha by 30%. Animals exposed to smoke for 4 months and then to smoke plus ZD0892 for 2 months were not protected against emphysema. Mice exposed to smoke showed increases in gene expression of neutrophil chemoattractant macrophage inflammatory protein-2, macrophage chemoattractant protein-1, and TNF-alpha at 2 hours along with increased plasma TNF-alpha; ZD0892 prevented the increases in macrophage inflammatory protein-2 and macrophage chemoattractant protein-1 expression and reduced plasma TNF-alpha levels to baseline. These data demonstrate that a serine elastase inhibitor ameliorates the inflammatory and destructive effects of cigarette smoke, and that these effects are mediated in part by neutrophils and by smoke-driven TNF-alpha production.

In utero and postnatal exposure to arsenic alters pulmonary structure and function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, R. Clark; Southwest Environmental Health Science Center, University of Arizona, Tucson, AZ 85721; BIO5 Institute, University of Arizona, Tucson, AZ 85721

2009-02-15

In addition to cancer endpoints, arsenic exposures can also lead to non-cancerous chronic lung disease. Exposures during sensitive developmental time points can contribute to the adult disease. Using a mouse model, in utero and early postnatal exposures to arsenic (100 ppb or less in drinking water) were found to alter airway reactivity to methacholine challenge in 28 day old pups. Removal of mice from arsenic exposure 28 days after birth did not reverse the alterations in sensitivity to methacholine. In addition, adult mice exposed to similar levels of arsenic in drinking water did not show alterations. Therefore, alterations in airwaymore » reactivity were irreversible and specific to exposures during lung development. These functional changes correlated with protein and gene expression changes as well as morphological structural changes around the airways. Arsenic increased the whole lung levels of smooth muscle actin in a dose dependent manner. The level of smooth muscle mass around airways was increased with arsenic exposure, especially around airways smaller than 100 {mu}m in diameter. This increase in smooth muscle was associated with alterations in extracellular matrix (collagen, elastin) expression. This model system demonstrates that in utero and postnatal exposure to environmentally relevant levels of arsenic can irreversibly alter pulmonary structure and function in the adults.« less

Inhibition of microRNA-29 enhances elastin levels in cells haploinsufficient for elastin and in bioengineered vessels--brief report.

PubMed

Zhang, Pei; Huang, Angela; Ferruzzi, Jacopo; Mecham, Robert P; Starcher, Barry C; Tellides, George; Humphrey, Jay D; Giordano, Frank J; Niklason, Laura E; Sessa, William C

2012-03-01

The goal of this study was to determine whether antagonizing microRNA (miR)-29 enhances elastin (ELN) levels in cells and tissues lacking ELN. miR-29 mimics reduced ELN levels in fibroblasts and smooth muscle cells, whereas miR-29 inhibition increased ELN levels. Antagonism of miR-29 also increased ELN levels in cells from patients haploinsufficient for ELN and in bioengineered human vessels. miR-29 antagonism may promote increased ELN levels during conditions of ELN deficiencies.

The Human Skeletal Muscle Transcriptome in Response to Oral Shilajit Supplementation

PubMed Central

Das, Amitava; Datta, Soma; Rhea, Brian; Sinha, Mithun; Veeraragavan, Muruganandam; Gordillo, Gayle

2016-01-01

Abstract The objective of the present study (clinicaltrials.gov NCT02026414) was to observe the effects of oral supplementation of a purified and standardized Shilajit extract on skeletal muscle adaptation in adult overweight/class I obese human subjects from the U.S. population. Shilajit is a mineral pitch that oozes out of Himalayan rocks. The study design consisted of a baseline visit, followed by 8 weeks of 250 mg of oral Shilajit supplementation b.i.d., and additional 4 weeks of supplementation with exercise. At each visit, blood samples and muscle biopsies were collected for further analysis. Supplementation was well tolerated without any changes in blood glucose levels and lipid profile after 8 weeks of oral supplementation and the additional 4 weeks of oral supplementation with exercise. In addition, no changes were noted in creatine kinase and serum myoglobin levels after 8 weeks of oral supplementation and the additional 4 weeks of supplementation with exercise. Microarray analysis identified a cluster of 17 extracellular matrix (ECM)-related probe sets that were significantly upregulated in muscles following 8 weeks of oral supplementation compared with the expression at the baseline visit. This cluster included tenascin XB, decorin, myoferlin, collagen, elastin, fibrillin 1, and fibronectin 1. The differential expression of these genes was confirmed using quantitative real-time polymerase chain reaction (RT-PCR). The study provided maiden evidence that oral Shilajit supplementation in adult overweight/class I obese human subjects promoted skeletal muscle adaptation through upregulation of ECM-related genes that control muscle mechanotransduction properties, elasticity, repair, and regeneration. PMID:27414521

The Human Skeletal Muscle Transcriptome in Response to Oral Shilajit Supplementation.

PubMed

Das, Amitava; Datta, Soma; Rhea, Brian; Sinha, Mithun; Veeraragavan, Muruganandam; Gordillo, Gayle; Roy, Sashwati

2016-07-01

The objective of the present study ( clinicaltrials.gov NCT02026414) was to observe the effects of oral supplementation of a purified and standardized Shilajit extract on skeletal muscle adaptation in adult overweight/class I obese human subjects from the U.S. Shilajit is a mineral pitch that oozes out of Himalayan rocks. The study design consisted of a baseline visit, followed by 8 weeks of 250 mg of oral Shilajit supplementation b.i.d., and additional 4 weeks of supplementation with exercise. At each visit, blood samples and muscle biopsies were collected for further analysis. Supplementation was well tolerated without any changes in blood glucose levels and lipid profile after 8 weeks of oral supplementation and the additional 4 weeks of oral supplementation with exercise. In addition, no changes were noted in creatine kinase and serum myoglobin levels after 8 weeks of oral supplementation and the additional 4 weeks of supplementation with exercise. Microarray analysis identified a cluster of 17 extracellular matrix (ECM)-related probe sets that were significantly upregulated in muscles following 8 weeks of oral supplementation compared with the expression at the baseline visit. This cluster included tenascin XB, decorin, myoferlin, collagen, elastin, fibrillin 1, and fibronectin 1. The differential expression of these genes was confirmed using quantitative real-time polymerase chain reaction (RT-PCR). The study provided maiden evidence that oral Shilajit supplementation in adult overweight/class I obese human subjects promoted skeletal muscle adaptation through upregulation of ECM-related genes that control muscle mechanotransduction properties, elasticity, repair, and regeneration.

Comparative transcriptional analysis of three human ligaments with distinct biomechanical properties

PubMed Central

Lorda-Diez, Carlos I; Canga-Villegas, Ana; Cerezal, Luis; Plaza, Santiago; Hurlé, Juan M; García-Porrero, Juan A; Montero, Juan A

2013-01-01

One major aim of regenerative medicine targeting the musculoskeletal system is to provide complementary and/or alternative therapeutic approaches to current surgical therapies, often involving the removal and prosthetic substitution of damaged tissues such as ligaments. For these approaches to be successful, detailed information regarding the cellular and molecular composition of different musculoskeletal tissues is required. Ligaments have often been considered homogeneous tissues with common biomechanical properties. However, advances in tissue engineering research have highlighted the functional relevance of the organisational and compositional differences between ligament types, especially in those with higher risks of injury. The aim of this study was to provide information concerning the relative expression levels of a subset of key genes (including extracellular matrix components, transcription factors and growth factors) that confer functional identity to ligaments. We compared the transcriptomes of three representative human ligaments subjected to different biomechanical demands: the anterior cruciate ligament (ACL); the ligamentum teres of the hip (LT); and the iliofemoral ligament (IL). We revealed significant differences in the expression of type I collagen, elastin, fibromodulin, biglycan, transforming growth factor β1, transforming growth interacting factor 1, hypoxia-inducible factor 1-alpha and transforming growth factor β-induced gene between the IL and the other two ligaments. Thus, considerable molecular heterogeneity can exist between anatomically distinct ligaments with differing biomechanical demands. However, the LT and ACL were found to show remarkable molecular homology, suggesting common functional properties. This finding provides experimental support for the proposed role of the LT as a hip joint stabiliser in humans. PMID:24128114

Increased fibroblast density in actinic cheilitis: association with tryptase-positive mast cells, actinic elastosis and epithelial p53 and COX-2 expression.

PubMed

Rojas, Isolde G; Boza, Yadira V; Spencer, Maria Loreto; Flores, Maritza; Martínez, Alejandra

2012-01-01

Actinic cheilitis (AC) is characterized by epithelial and connective tissue alterations caused by ultraviolet sunlight overexposure known as photodamage. Fibroblasts have been linked to photodamage and tumor progression during skin carcinogenesis; however, their role in early lip carcinogenesis remains unknown. The aim of this study was to assess the density of fibroblasts in AC and normal lip (NL) samples and determine their association with markers of lip photodamage. Fibroblasts, mast cells, p53, COX-2, and elastin were detected in NL (n = 20) and AC (n = 28) biopsies using immunohistochemistry/histochemistry. Mast cell and fibroblast density and epithelial p53 and COX-2 expression scores were then obtained. Elastosis was scored 1-4 according to elastin fiber density and tortuosity. Fibroblasts, mast cells, p53, COX-2, and elastosis were increased in AC as compared to NL (P < 0.001). Multivariate analysis showed an association between fibroblast and mast cell density at the papillary and reticular areas of AC and NL (P < 0.05). Papillary fibroblast density was also associated with epithelial p53 and COX-2 expression (P < 0.05). Increased fibroblast density, both papillary and reticular, was found in the high elastosis group (scores 3-4) as compared to the low elastosis group (scores 1-2) (P < 0.01). Increased reticular mast cell density was detected only in the high elastosis group (P < 0.01). Fibroblasts are increased in AC, and they are associated with mast cell density, epithelial p53 and COX-2 expression, and actinic elastosis. Therefore, fibroblasts may contribute to lip photodamage and could be considered useful markers of early lip carcinogenesis. © 2011 John Wiley & Sons A/S.

Col-F, a fluorescent probe for ex vivo confocal imaging of collagen and elastin in animal tissues.

PubMed

Biela, Ewa; Galas, Jerzy; Lee, Brian; Johnson, Gary L; Darzynkiewicz, Zbigniew; Dobrucki, Jurek W

2013-06-01

A new low-molecular-weight fluorescent probe, Col-F, that exhibits affinity to collagen and elastin, was used successfully in imaging of extracellular matrix in freshly excised animal tissues. Col-F readily penetrates between live cells into tissues and binds to fibers of collagen and elastin by a noncovalent mechanism. Fibers of collagen and elastin have been stained in a variety of tissues, including tendon, skeletal muscle, connective tissue, and arteries. Cells migrating in a Col-F-stained collagenous biomaterial were also imaged. No phototoxic effects were detected when live keratocytes were imaged in the in vitro culture in the presence of Col-F. In conclusion, Col-F provides a simple and convenient tool for fluorescence three-dimensional imaging of intricate collagenous and elastic structures in live and fixed animal tissues, as well as in collagen-containing biomaterials. Copyright © 2013 International Society for Advancement of Cytometry.

Expression and Purification of Neurotrophin-Elastin-Like Peptide Fusion Proteins for Neural Regeneration.

PubMed

Johnson, Tamina; Koria, Piyush

2016-04-01

Neural injuries such as spinal cord injuries, traumatic brain injuries, or nerve transection injuries pose a major health problem. Neurotrophins such as nerve growth factor (NGF) or brain-derived neurotrophic factor (BDNF) have been shown to improve the outcome of neural injuries in several pre-clinical models, but their use in clinics is limited by the lack of a robust delivery system that enhances their bioavailability and half-life. We describe two fusion proteins comprising NGF or BDNF fused with elastin-like peptides (ELPs). The aim of this study was to investigate the biological activity of neurotrophin-ELP (N-ELP) fusion proteins via in vitro culture models. NGF and BDNF were cloned in front of an elastin-like polypeptide sequence V40C2. These proteins were expressed in bacteria as inclusion bodies. These fusion proteins underwent solubilization via 8 M urea and purification via inverse transition cycling (ITC). We measured the particle size and the effect of temperature on precipitated particles using dynamic light scattering (DLS). We used western blot analysis to confirm the specificity of NGF-ELP to tropomyosin receptor kinase A (TrkA) antibody and to confirm the specificity of BDNF-ELP to TrkB antibody. PC12 cells were used to perform a neurite outgrowth assay to determine the biological activity of NGF-ELP. Bioactivity of BDNF-ELP was ascertained via transfecting human epithelial kidney (HEK 293-T) cells to express the TrkB receptor. The proteins were successfully purified to high homogeneity by exploiting the phase transition property of ELPs and urea, which solubilize inclusion bodies. Using PC12 neurite outgrowth assay, we further demonstrated that the biological activity of NGF was retained in the fusion. Similarly, BDNF-ELP phosphorylated the TrkB receptor, suggesting the biological activity of BDNF was also retained in the fusion. We further show that owing to the phase transition property of ELPs in the fusion, these proteins self-assembled into nanoparticles at their respective transition temperatures. These fusion proteins are useful for neural regeneration, as they not only retain the biological activity of the neurotrophin but also self-assemble into nanoparticles, thereby simultaneously serving as drug-delivery vehicles. These nanoparticles can serve as drug depots and will increase bioavailability by limiting neurotrophin loss due to diffusion, thereby allowing controlled spatio-temporal delivery of the neurotrophin.

NMR and Bioinformatics Discovery of Exosites That Tune Metalloelastase Specificity for Solubilized Elastin and Collagen Triple Helices*

PubMed Central

Palmier, Mark O.; Fulcher, Yan G.; Bhaskaran, Rajagopalan; Duong, Vinh Q.; Fields, Gregg B.; Van Doren, Steven R.

2010-01-01

The catalytic domain of metalloelastase (matrix metalloproteinase-12 or MMP-12) is unique among MMPs in exerting high proteolytic activity upon fibrils that resist hydrolysis, especially elastin from lungs afflicted with chronic obstructive pulmonary disease or arteries with aneurysms. How does the MMP-12 catalytic domain achieve this specificity? NMR interface mapping suggests that α-elastin species cover the primed subsites, a strip across the β-sheet from β-strand IV to the II–III loop, and a broad bowl from helix A to helix C. The many contacts may account for the comparatively high affinity, as well as embedding of MMP-12 in damaged elastin fibrils in vivo. We developed a strategy called BINDSIght, for bioinformatics and NMR discovery of specificity of interactions, to evaluate MMP-12 specificity without a structure of a complex. BINDSIght integration of the interface mapping with other ambiguous information from sequences guided choice mutations in binding regions nearer the active site. Single substitutions at each of ten locations impair specific activity toward solubilized elastin. Five of them impair release of peptides from intact elastin fibrils. Eight lesions also impair specific activity toward triple helices from collagen IV or V. Eight sites map to the “primed” side in the III–IV, V–B, and S1′ specificity loops. Two map to the “unprimed” side in the IV–V and B–C loops. The ten key residues circumscribe the catalytic cleft, form an exosite, and are distinctive features available for targeting by new diagnostics or therapeutics. PMID:20663866

Pathogenesis of aortic dilatation in mucopolysaccharidosis VII mice may involve complement activation

PubMed Central

Baldo, Guilherme; Wu, Susan; Howe, Ruth A.; Ramamoothy, Meera; Knutsen, Russell H.; Fang, Jiali; Mecham, Robert P.; Liu, Yuli; Wu, Xiaobo; Atkinson, John P.; Ponder, Katherine P.

2012-01-01

Mucopolysaccharidosis VII (MPS VII) is due to mutations within the gene encoding the lysosomal enzyme β-glucuronidase, and results in the accumulation of glycosaminoglycans. MPS VII causes aortic dilatation and elastin fragmentation, which is associated with upregulation of the elastases cathepsin S (CtsS) and matrix metalloproteinase 12 (MMP12). To test the role of these enzymes, MPS VII mice were crossed with mice deficient in CtsS or MMP12, and the effect upon aortic dilatation was determined. CtsS deficiency did not protect against aortic dilatation in MPS VII mice, but also failed to prevent an upregulation of cathepsin enzyme activity. Further analysis with substrates and inhibitors specific for particular cathepsins suggests that this enzyme activity was due to CtsB, which could contribute to elastin fragmentation. Similarly, MMP12 deficiency and deficiency of both MMP12 and CtsS could not prevent aortic dilatation in MPS VII mice. Microarray and reverse-transcriptase real-time PCR were performed to look for upregulation of other elastases. This demonstrated that mRNA for complement component D was elevated in MPS VII mice, while immunostaining demonstrated high levels of complement component C3 on surfaces within the aortic media. Finally, we demonstrate that neonatal intravenous injection of a retroviral vector encoding β-glucuronidase reduced aortic dilatation. We conclude that neither CtsS nor MMP12 are necessary for elastin fragmentation in MPS VII mouse aorta, and propose that CtsB and/or complement component D may be involved. Complement may be activated by the GAGs that accumulate, and may play a role in signal transduction pathways that upregulate elastases. PMID:21944884

Williams syndrome predisposes to vascular stiffness modified by antihypertensive use and copy number changes in NCF1.

PubMed

Kozel, Beth A; Danback, Joshua R; Waxler, Jessica L; Knutsen, Russell H; de Las Fuentes, Lisa; Reusz, Gyorgy S; Kis, Eva; Bhatt, Ami B; Pober, Barbara R

2014-01-01

Williams syndrome is caused by the deletion of 26 to 28 genes, including elastin, on human chromosome 7. Elastin insufficiency leads to the cardiovascular hallmarks of this condition, namely focal stenosis and hypertension. Extrapolation from the Eln(+/-) mouse suggests that affected people may also have stiff vasculature, a risk factor for stroke, myocardial infarction, and cardiac death. NCF1, one of the variably deleted Williams genes, is a component of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex and is involved in the generation of oxidative stress, making it an interesting candidate modifier for vascular stiffness. Using a case-control design, vascular stiffness was evaluated by pulse wave velocity in 77 Williams cases and matched controls. Cases had stiffer conducting vessels than controls (P<0.001), with increased stiffness observed in even the youngest children with Williams syndrome. Pulse wave velocity increased with age at comparable rates in cases and controls, and although the degree of vascular stiffness varied, it was seen in both hypertensive and normotensive Williams participants. Use of antihypertensive medication and extension of the Williams deletion to include NCF1 were associated with protection from vascular stiffness. These findings demonstrate that vascular stiffness is a primary vascular phenotype in Williams syndrome and that treatment with antihypertensives or agents inhibiting oxidative stress may be important in managing patients with this condition, potentially even those who are not overtly hypertensive.

Computational smart polymer design based on elastin protein mutability.

PubMed

Tarakanova, Anna; Huang, Wenwen; Weiss, Anthony S; Kaplan, David L; Buehler, Markus J

2017-05-01

Soluble elastin-like peptides (ELPs) can be engineered into a range of physical forms, from hydrogels and scaffolds to fibers and artificial tissues, finding numerous applications in medicine and engineering as "smart polymers". Elastin-like peptides are attractive candidates as a platform for novel biomaterial design because they exhibit a highly tunable response spectrum, with reversible phase transition capabilities. Here, we report the design of the first virtual library of elastin-like protein models using methods for enhanced sampling to study the effect of peptide chemistry, chain length, and salt concentration on the structural transitions of ELPs, exposing associated molecular mechanisms. We describe the behavior of the local molecular structure under increasing temperatures and the effect of peptide interactions with nearest hydration shell water molecules on peptide mobility and propensity to exhibit structural transitions. Shifts in the magnitude of structural transitions at the single-molecule scale are explained from the perspective of peptide-ion-water interactions in a library of four unique elastin-like peptide systems. Predictions of structural transitions are subsequently validated in experiment. This library is a valuable resource for recombinant protein design and synthesis as it elucidates mechanisms at the single-molecule level, paving a feedback path between simulation and experiment for smart material designs, with applications in biomedicine and diagnostic devices. Copyright © 2017. Published by Elsevier Ltd.

Elastin: a representative ideal protein elastomer.

PubMed Central

Urry, D W; Hugel, T; Seitz, M; Gaub, H E; Sheiba, L; Dea, J; Xu, J; Parker, T

2002-01-01

During the last half century, identification of an ideal (predominantly entropic) protein elastomer was generally thought to require that the ideal protein elastomer be a random chain network. Here, we report two new sets of data and review previous data. The first set of new data utilizes atomic force microscopy to report single-chain force-extension curves for (GVGVP)(251) and (GVGIP)(260), and provides evidence for single-chain ideal elasticity. The second class of new data provides a direct contrast between low-frequency sound absorption (0.1-10 kHz) exhibited by random-chain network elastomers and by elastin protein-based polymers. Earlier composition, dielectric relaxation (1-1000 MHz), thermoelasticity, molecular mechanics and dynamics calculations and thermodynamic and statistical mechanical analyses are presented, that combine with the new data to contrast with random-chain network rubbers and to detail the presence of regular non-random structural elements of the elastin-based systems that lose entropic elastomeric force upon thermal denaturation. The data and analyses affirm an earlier contrary argument that components of elastin, the elastic protein of the mammalian elastic fibre, and purified elastin fibre itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension. PMID:11911774

Complementary effects of multi-protein components on biomineralization in vitro

PubMed Central

Ba, Xiaolan; Rafailovich, Miriam; Meng, Yizhi; Pernodet, Nadine; Wirick, Sue; Füredi-Milhofer, Helga; Qin, Yi-Xian; DiMasi, Elaine

2016-01-01

The extracellular matrix (ECM) is composed of mixed protein fibers whose precise composition affects biomineralization. New methods are needed to probe the interactions of these proteins with calcium phosphate mineral and with each other. Here we follow calcium phosphate mineralization on protein fibers self-assembled in vitro from solutions of fibronectin, elastin and their mixture. We probe the surface morphology and mechanical properties of the protein fibers during the early stages. The development of mineral crystals on the protein matrices is also investigated. In physiological mineralization solution, the elastic modulus of the fibers in the fibronectin-elastin mixture increases to a greater extent than that of the fibers from either pure protein. In the presence of fibronectin, longer exposure in the mineral solution leads to the formation of amorphous calcium phosphate particles templated along the self-assembled fibers, while elastin fibers only collect calcium without any mineral observed during early stage. TEM images confirm that small needle-shape crystals are confined inside elastin fibers which suppress the release of mineral outside the fibers during late stage, while hydroxyapatite crystals form when fibronectin is present. These results demonstrate complementary actions of the two ECM proteins fibronectin and elastin to collect cations and template mineral, respectively. PMID:20035875

Nitinol-based Nanotubular and Nanowell Coatings for the Modulation of Human Vascular Cell Functions

NASA Astrophysics Data System (ADS)

Lee, Phin Peng

Current approaches to reducing restenosis do not balance the reduction of vascular smooth muscle cell proliferation with the increase in the healing of the endothelium. Here, I present my study on the synthesis and characterization of a nanotubular coating on Nitinol substrates. I found that the coating demonstrated 'pro-healing' properties by increasing primary human aortic endothelial cell spreading, migration and collagen and elastin production. Certain cellular functions such as collagen and elastin production were also found to be affected by changes in nanotube diameter. The coating also reduced the proliferation and mRNA expression of collagen I and MMP2 for primary human aortic smooth muscle cells. I will also demonstrate the synthesis of a nanowell coating on Nitinol stents as well as an additional poly(lactic-co-glycolic acid) coating on top of the nanowells that has the potential for controlling drug release. These findings demonstrate the potential for the coatings to aid in the prevention of restenosis and sets up future explorations of ex vivo and in vivo studies.

Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly

NASA Astrophysics Data System (ADS)

Mozhdehi, Davoud; Luginbuhl, Kelli M.; Simon, Joseph R.; Dzuricky, Michael; Berger, Rüdiger; Varol, H. Samet; Huang, Fred C.; Buehne, Kristen L.; Mayne, Nicholas R.; Weitzhandler, Isaac; Bonn, Mischa; Parekh, Sapun H.; Chilkoti, Ashutosh

2018-05-01

Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C14 alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.

A new dermocosmetic containing retinaldehyde, delta-tocopherol glucoside and glycylglycine oleamide for managing naturally aged skin: results from in vitro to clinical studies

PubMed Central

Rouvrais, Céline; Bacqueville, Daniel; Bogdanowicz, Patrick; Haure, Marie-José; Duprat, Laure; Coutanceau, Christine; Castex-Rizzi, Nathalie; Duplan, Hélène; Mengeaud, Valérie; Bessou-Touya, Sandrine

2017-01-01

Introduction Natural aging of skin tissues, the addition of the cumulative action of the time and radiation exposure result in skin atrophy, wrinkles and degeneration of the extracellular matrix (ECM). The aim of the study was to investigate the beneficial effect of a combination containing retinaldehyde (RAL), delta-tocopherol glucoside (delta-TC) and glycylglycine ole-amide (GGO) and of a dermocosmetic containing the combination. Materials and methods The protective effect of the combination was assessed through in vitro gene expression of ultraviolet (UV)-irradiated fibroblasts. A skin aging assay using UV light on ex vivo skin samples and a clinical study conducted in 36 women aged from 35 to 55 years with a minimum of level 4 to a maximum of level 6 on the crow’s feet photoscale assessed the antiaging effect of the dermocosmetic. Results When added to UV-irradiated fibroblasts, the combination substantially improved the ECM in activating the elastin fiber production (fibrillin 2, fibulin 1 and 5 and lysyl oxidase-like 2) as well as that of proteins involved in the cellular ECM interactions (integrin b1, paxillin and actin a2). An ex vivo photodamaged human skin model showed that the dermocosmetic formulation containing the combination of the active ingredients protected the elastic network against UV-induced alterations including both elastin and fibrillin-rich fibers in the dermis. A daily application of the dermocosmetic for 2 months on naturally aged skin resulted in a statistically significant improvement (p<0.05) of visible signs of aging comprising crow’s feet, wrinkles and periocular fine lines. Finally, the formulation was well tolerated. Conclusion The dermocosmetic containing RAL, delta-TC and GGO provides a substantial benefit in the daily care of naturally aged skin in women aged 35–55 years. PMID:28203099

Fibulin-4 E57K Knock-in Mice Recapitulate Cutaneous, Vascular and Skeletal Defects of Recessive Cutis Laxa 1B with both Elastic Fiber and Collagen Fibril Abnormalities.

PubMed

Igoucheva, Olga; Alexeev, Vitali; Halabi, Carmen M; Adams, Sheila M; Stoilov, Ivan; Sasaki, Takako; Arita, Machiko; Donahue, Adele; Mecham, Robert P; Birk, David E; Chu, Mon-Li

2015-08-28

Fibulin-4 is an extracellular matrix protein essential for elastic fiber formation. Frameshift and missense mutations in the fibulin-4 gene (EFEMP2/FBLN4) cause autosomal recessive cutis laxa (ARCL) 1B, characterized by loose skin, aortic aneurysm, arterial tortuosity, lung emphysema, and skeletal abnormalities. Homozygous missense mutations in FBLN4 are a prevalent cause of ARCL 1B. Here we generated a knock-in mouse strain bearing a recurrent fibulin-4 E57K homozygous missense mutation. The mutant mice survived into adulthood and displayed abnormalities in multiple organ systems, including loose skin, bent forelimb, aortic aneurysm, tortuous artery, and pulmonary emphysema. Biochemical studies of dermal fibroblasts showed that fibulin-4 E57K mutant protein was produced but was prone to dimer formation and inefficiently secreted, thereby triggering an endoplasmic reticulum stress response. Immunohistochemistry detected a low level of fibulin-4 E57K protein in the knock-in skin along with altered expression of selected elastic fiber components. Processing of a precursor to mature lysyl oxidase, an enzyme involved in cross-linking of elastin and collagen, was compromised. The knock-in skin had a reduced level of desmosine, an elastin-specific cross-link compound, and ultrastructurally abnormal elastic fibers. Surprisingly, structurally aberrant collagen fibrils and altered organization into fibers were characteristics of the knock-in dermis and forelimb tendons. Type I collagen extracted from the knock-in skin had decreased amounts of covalent intermolecular cross-links, which could contribute to the collagen fibril abnormalities. Our studies provide the first evidence that fibulin-4 plays a role in regulating collagen fibril assembly and offer a preclinical platform for developing treatments for ARCL 1B. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Upregulation of MMP12 and its activity by UVA1 in human skin: potential implications for photoaging.

PubMed

Tewari, Angela; Grys, Katarzyna; Kollet, Jutta; Sarkany, Robert; Young, Antony R

2014-10-01

UVA1 constitutes around 75% of the terrestrial UV radiation, and most of the output of artificial tanning sources. However, the molecular effects of UVA1 in human skin in vivo are surprisingly poorly understood. We have examined time-dependent whole-genome expression, along with mRNA and protein changes in the skin after one minimal erythema dose of spectrally pure UVA1 (50 J cm(-2)) and 300 nm UVB (30 mJ cm(-2)). After 24 hours, the genes induced to the greatest extent were those involved in extracellular matrix remodeling with both UVA1 (P=5.5e-7) and UVB (P=2.9e-22). UVA1 and UVB caused different effects on matrix metalloproteinase (MMP) expression: UVB induced MMP1, MMP3, and MMP10 mRNA at 24 hours to a much greater extent than UVA1. MMP12 induction by UVA1 at 6 hours is marked and much greater than that by UVB. We have found that MMP12 mRNA induction by UVA1 resulted in expression of MMP12 protein, which is functional as an elastase. This induction of elastase activity did not occur with UVB. We hypothesize that the UVA1 induction of MMP12 mediates some of its photoaging effects, particularly by contributing to elastin degeneration in late solar elastosis. MMP12 is a good marker of UVA1 exposure.

Lung matrix and vascular remodeling in mechanically ventilated elastin haploinsufficient newborn mice

PubMed Central

Hilgendorff, Anne; Parai, Kakoli; Ertsey, Robert; Navarro, Edwin; Jain, Noopur; Carandang, Francis; Peterson, Joanna; Mokres, Lucia; Milla, Carlos; Preuss, Stefanie; Alcazar, Miguel Alejandre; Khan, Suleman; Masumi, Juliet; Ferreira-Tojais, Nancy; Mujahid, Sana; Starcher, Barry; Rabinovitch, Marlene

2014-01-01

Elastin plays a pivotal role in lung development. We therefore queried if elastin haploinsufficient newborn mice (Eln+/−) would exhibit abnormal lung structure and function related to modified extracellular matrix (ECM) composition. Because mechanical ventilation (MV) has been linked to dysregulated elastic fiber formation in the newborn lung, we also asked if elastin haploinsufficiency would accentuate lung growth arrest seen after prolonged MV of neonatal mice. We studied 5-day-old wild-type (Eln+/+) and Eln+/− littermates at baseline and after MV with air for 8–24 h. Lungs of unventilated Eln+/− mice contained ∼50% less elastin and ∼100% more collagen-1 and lysyl oxidase compared with Eln+/+ pups. Eln+/− lungs contained fewer capillaries than Eln+/+ lungs, without discernible differences in alveolar structure. In response to MV, lung tropoelastin and elastase activity increased in Eln+/+ neonates, whereas tropoelastin decreased and elastase activity was unchanged in Eln+/− mice. Fibrillin-1 protein increased in lungs of both groups during MV, more in Eln+/− than in Eln+/+ pups. In both groups, MV caused capillary loss, with larger and fewer alveoli compared with unventilated controls. Respiratory system elastance, which was less in unventilated Eln+/− compared with Eln+/+ mice, was similar in both groups after MV. These results suggest that elastin haploinsufficiency adversely impacts pulmonary angiogenesis and that MV dysregulates elastic fiber integrity, with further loss of lung capillaries, lung growth arrest, and impaired respiratory function in both Eln+/+ and Eln+/− mice. Paucity of lung capillaries in Eln+/− newborns might help explain subsequent development of pulmonary hypertension previously reported in adult Eln+/− mice. PMID:25539853

Direct detection of crosslinks of collagen and elastin in the hydrolysates of human yellow ligament using single-column high performance liquid chromatography.

PubMed

Chen, J R; Takahashi, M; Kushida, K; Suzuki, M; Suzuki, K; Horiuchi, K; Nagano, A

2000-02-15

Collagen and elastin are recognized as two major connective tissue proteins of human yellow ligament. In both collagen and elastin there are many kinds of intra- or intermolecular crosslinks. Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are mature crosslinks which maintain the structure of the collagen fibril. Desmosine (Des) and isodesmosine (Isodes) represent the major crosslinking components of elastin. Pentosidine (Pen), which is a senescent crosslink and one of the advanced glycation end products, accumulates with age in tissue proteins including collagen. We developed a direct and one-injection HPLC method to measure Pyr, Dpyr, Des, Isodes, and Pen in the hydrolysate of human yellow ligament. This method used one column and two detectors. Recovery rates of Pyr, Dpyr, Pen, Des, and Isodes were 86.4-98.3, 83.6-96.8, 78.7-95.6, 83.6-97.9, and 85.6-99.3%, respectively (n = 8). The intraassay coefficients of variation for Pyr, Dpyr, Pen, Des, and Isodes were 3.7, 4.1, 5.4, 4.5, and 4.7%, respectively (n = 8), and the interassay coefficients of variation for Pyr, Dpyr, Pen, Des, and Isodes were 4.4, 5.1, 4.9, 4.6 and 4.1%, respectively. Linear regression analysis showed the linearity (r = 0.99, P = 0.0001) of calibration line for each Pyr, Dpyr, Pen, Des, and Isodes. Using this method, we investigated age-related changes in the crosslinks of collagen and elastin in human yellow ligament. There was a significant correlation between Pen and age, but no correlations with Pyr, Dpyr, Des, and Isodes. We believe that this method is useful for investigating the content of these crosslinks in both collagen and elastin under various conditions. Copyright 2000 Academic Press.

Compared With Elastin Stains, h-Caldesmon and Desmin Offer Superior Detection of Vessel Invasion in Gastric, Pancreatic, and Colorectal Adenocarcinomas.

PubMed

Ekinci, Özgür; Öğüt, Betül; Çelik, Bülent; Dursun, Ayşe

2018-06-01

The presence of vessel invasion is considered indicative of a poor prognosis in many malignant tumors. We aimed to compare the sensitivity of elastin stains (van Gieson's and orcein methods) with 2 smooth muscle markers (h-caldesmon and desmin) in gastric, pancreatic, and colorectal adenocarcinoma specimens. We used 27 (29.3%) gastric, 35 (38.0%) pancreatic, and 30 (32.6%) colorectal resection specimens. We applied a provisional classification of vessel invasion patterns: type A, a focus with a nearby artery unaccompanied by a vein; type T, a focus at the invasive front without an unaccompanied artery; and type X, foci that only appeared by any of the 4 stains used. There were 369 foci. The smooth muscle markers were more sensitive than the elastin stains, and h-caldesmon more sensitive than desmin, in all types. Among the 139 type A foci, 33 (23.7%) were positive by desmin and h-caldesmon, whereas the elastin stains were not ( P = .001). h-Caldesmon was the only positive marker in 11 (7.9%; P = .011). Among the 78 type T foci, 21 (26.9%) were positive by desmin and h-caldesmon, when both elastin stains were negative ( P = .000). In 16 (20.5%) foci, h-caldesmon was the only positive marker ( P = .002). Among 152 type X foci, 91 (59.9%) were positive by all markers, 26 (17.1%) by both desmin and h-caldesmon, and 9 (5.9%) by only the 2 elastin stains ( P = .001). We recommend these stains for suspect foci in gastric, pancreatic, and colorectal adenocarcinoma specimens. They might highlight both predictable and unpredictable foci.

Ferroelectric switching of elastin

PubMed Central

Liu, Yuanming; Cai, Hong-Ling; Zelisko, Matthew; Wang, Yunjie; Sun, Jinglan; Yan, Fei; Ma, Feiyue; Wang, Peiqi; Chen, Qian Nataly; Zheng, Hairong; Meng, Xiangjian; Sharma, Pradeep; Zhang, Yanhang; Li, Jiangyu

2014-01-01

Ferroelectricity has long been speculated to have important biological functions, although its very existence in biology has never been firmly established. Here, we present compelling evidence that elastin, the key ECM protein found in connective tissues, is ferroelectric, and we elucidate the molecular mechanism of its switching. Nanoscale piezoresponse force microscopy and macroscopic pyroelectric measurements both show that elastin retains ferroelectricity at 473 K, with polarization on the order of 1 μC/cm2, whereas coarse-grained molecular dynamics simulations predict similar polarization with a Curie temperature of 580 K, which is higher than most synthetic molecular ferroelectrics. The polarization of elastin is found to be intrinsic in tropoelastin at the monomer level, analogous to the unit cell level polarization in classical perovskite ferroelectrics, and it switches via thermally activated cooperative rotation of dipoles. Our study sheds light onto a long-standing question on ferroelectric switching in biology and establishes ferroelectricity as an important biophysical property of proteins. This is a critical first step toward resolving its physiological significance and pathological implications. PMID:24958890

Changes in the composition of the thoracic aortic wall in spontaneously hypertensive rats treated with losartan or spironolactone.

PubMed

Han, Wei-Qing; Wu, Ling-Yun; Zhou, Hai-Yan; Zhang, Jia; Che, Zai-Qian; Wu, Yong-Jie; Liu, Jian-Jun; Zhu, Ding-Liang; Gao, Ping-Jin

2009-05-01

1. In the present study, we compared the elastin and collagen content of thoracic aortic medial and adventitial layers from Wistar-kyoto (WKY) and spontaneously hypertensive rats (SHR). In addition, the effects of losartan, an angiotensin II receptor antagonist, and spironolactone, a mineralocorticoid receptor antagonist, on collagen and elastin content were determined. 2. Prehypertensive (4-week-old) and hypertensive (16-week-old) SHR were randomly divided into three groups treated with either 0.9% NaCl, losartan (20 mg/kg per day) or spironolactone (200 mg/kg per day). Prehypertensive and hypertensive SHR were treated for 12 and 16 weeks, respectively. Age-matched WKY rats were not treated with NaCl, losartan or spironolactone and served as the control group. 3. The medial and adventitial layers of the thoracic aorta were composed mainly of elastin and collagen, respectively, in both SHR and WKY rats. Compared with WKY rats, SHR exhibited greater collagen and elastin content in the media, but decreased collagen and elastin content in the adventitial layer. Both medial and adventitial collagen and elastin content increased significantly with age in both strains and was greater in 32-week-old rats compared with 16-week-old rats. Spironolactone treatment decreased collagen content in the media of thoracic aortas from prehypertensive SHR, whereas losartan decreased collagen content in the media of aortas from hypertensive SHR. In contrast, neither spironolactone nor losartan had any effect on adventitial collagen content in prehypertensive and hypertensive SHR. Medial collagen and elastin were positively related to pulse pressure (PP), but there was no correlation between adventitial mass or collagen content and PP or mean arterial pressure in untreated and treated SHR and WKY rats. 4. In conclusion, the composition of the medial and adventitial layers of the thoracic aorta differs and treatment of SHR with losartan and spironolactone decreases collagen content when delivered at the hypertensive or prehypertensive stage, respectively. However, neither drug has any effect on adventitial collagen content in SHR.

Changes in Cell Wall Properties Coincide with Overexpression of Extensin Fusion Proteins in Suspension Cultured Tobacco Cells

DOE PAGES

Tan, Li; Pu, Yunqiao; Pattathil, Sivakumar; ...

2014-12-23

Extensins are one subfamily of the cell wall hydroxyproline-rich glycoproteins, containing characteristic SerHyp4 glycosylation motifs and intermolecular cross-linking motifs such as the TyrXaaTyr sequence. Extensins are believed to form a cross-linked network in the plant cell wall through the tyrosine-derivatives isodityrosine, pulcherosine, and di-isodityrosine. Overexpression of three synthetic genes encoding different elastin-arabinogalactan protein-extensin hybrids in tobacco suspension cultured cells yielded novel cross-linking glycoproteins that shared features of the extensins, arabinogalactan proteins and elastin. The cell wall properties of the three transgenic cell lines were all changed, but in different ways. One transgenic cell line showed decreased cellulose crystallinity and increasedmore » wall xyloglucan content; the second transgenic cell line contained dramatically increased hydration capacity and notably increased cell wall biomass, increased di-isodityrosine, and increased protein content; the third transgenic cell line displayed wall phenotypes similar to wild type cells, except changed xyloglucan epitope extractability. In conclusion, these data indicate that overexpression of modified extensins may be a route to engineer plants for bioenergy and biomaterial production.« less

Confocal microscopy for automatic measurement of the density and distance between elastin fibers of histologic preparations of normotensive and hypertensive patients

NASA Astrophysics Data System (ADS)

Vieira, G.; Ferro, D. P.; Adam, R. L.; de Thomaz, A. A.; Cesar, C. L.; Metze, K.

2010-02-01

Elastic fibers are essential components of the human aorta, and there is an association between elastin fibers remodeling and several diseases. Hypertension is one such example of a disease leading to elastin fibers remodeling. These fibers can be easily seen in eosin-hematoxilin (HE) stained histologic sections when observed by UV-excited fluorescence microscopy or by a much more precise Laser Scanning Confocal Microscope (LSCM). In order to study the effect of the hypertension on the elastin fibers pattern we developed an automatic system (software and hardware) to count the number of elastin fibers and to measure the distance between them in a LSCM and used it compare the statistical distribution of the distance between these fibers in normotensive and hypertensive patients. The full image of the whole sample (2 or 3mm long) was composed by several 220×220μm frames with 512×512 pixels. The software counters fiber and distance between fibers. We compared the elastic fiber texture in routinely HE-stained histologic slides of the aorta ascendens in 24 normotensive and 30 hypertensive adult patients of both sexes and of similar age from our autopsy files. Our results show that the average number of fibers is the same for both cases but the distance between the fibers are larger for hypertensive patients than for normotensive ones.

Hydrogels for lung tissue engineering: Biomechanical properties of thin collagen-elastin constructs.

PubMed

Dunphy, Siobhán E; Bratt, Jessica A J; Akram, Khondoker M; Forsyth, Nicholas R; El Haj, Alicia J

2014-10-01

In this study, collagen-elastin constructs were prepared with the aim of producing a material capable of mimicking the mechanical properties of a single alveolar wall. Collagen has been used in a wide range of tissue engineering applications; however, due to its low mechanical properties its use is limited to non load-bearing applications without further manipulation using methods such as cross-linking or mechanical compression. Here, it was hypothesised that the addition of soluble elastin to a collagen hydrogel could improve its mechanical properties. Hydrogels made from collagen only and collagen plus varying amounts elastin were prepared. Young׳s modulus of each membrane was measured using the combination of a non-destructive indentation and a theoretical model previously described. An increase in Young׳s modulus was observed with increasing concentration of elastin. The use of non-destructive indentation allowed for online monitoring of the elastic moduli of cell-seeded constructs over 8 days. The addition of lung fibroblasts into the membrane increased the stiffness of the hydrogels further and cell-seeded collagen hydrogels were found to have a stiffness equal to the theoretical value for a single alveolar wall (≈5kPa). Through provision of some of the native extracellular matrix components of the lung parenchyma these scaffolds may be able to provide an initial building block toward the regeneration of new functional lung tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Morphometric changes in the aortic arch with advancing age in fetal to mature thoroughbred horses.

PubMed

Endoh, Chihiro; Matsuda, Kazuya; Okamoto, Minoru; Tsunoda, Nobuo; Taniyama, Hiroyuki

2017-03-28

Aortic rupture is a well recognized cause of sudden death in thoroughbred horses. Some microscopic lesions, such as those caused by cystic medial necrosis and medionecrosis, can lead to aortic rupture. However, these microscopic lesions are also observed in normal horses. On the other hand, a previous study of aortic rupture suggested that underlying elastin and collagen deposition disorders might be associated with aortic rupture. Therefore, the purpose of this study was to compare the structural components of the tunica media of the aortic arch, which is composed of elastin, collagen, smooth muscle cells and mucopolysaccharides (MPS), in fetal to mature thoroughbred horses. The percentage area of elastin was greatest in the young horses and subsequently decreased with aging. The percentage area of collagen increased with aging, and the elderly horses (aged ≥20) exhibited significantly higher percentage areas of collagen than the young horses. The percentage area of smooth muscle cells did not change with age. The percentage area of MPS was inversely proportional to the percentage area of elastin. The fetuses exhibited a markedly larger percentage area of MPS than the mature horses. We concluded that the medial changes seen in the aortic arch, which included a reduction in the amount of elastin and increases in the amounts of collagen and MPS, were age-related variations.

Human elastin polypeptides improve the biomechanical properties of three-dimensional matrices through the regulation of elastogenesis.

PubMed

Boccafoschi, Francesca; Ramella, Martina; Sibillano, Teresa; De Caro, Liberato; Giannini, Cinzia; Comparelli, Roberto; Bandiera, Antonella; Cannas, Mario

2015-03-01

The replacement of diseased tissues with biological substitutes with suitable biomechanical properties is one of the most important goal in tissue engineering. Collagen represents a satisfactory choice for scaffolds. Unfortunately, the lack of elasticity represents a restriction to a wide use of collagen for several applications. In this work, we studied the effect of human elastin-like polypeptide (HELP) as hybrid collagen-elastin matrices. In particular, we studied the biomechanical properties of collagen/HELP scaffolds considering several components involved in ECM remodeling (elastin, collagen, fibrillin, lectin-like receptor, metalloproteinases) and cell phenotype (myogenin, myosin heavy chain) with particular awareness for vascular tissue engineering applications. Elastin and collagen content resulted upregulated in collagen-HELP matrices, even showing an improved structural remodeling through the involvement of proteins to a ECM remodeling activity. Moreover, the hybrid matrices enhanced the contractile activity of C2C12 cells concurring to improve the mechanical properties of the scaffold. Finally, small-angle X-ray scattering analyses were performed to enable a very detailed analysis of the matrices at the nanoscale, comparing the scaffolds with native blood vessels. In conclusion, our work shows the use of recombinant HELP, as a very promising complement able to significantly improve the biomechanical properties of three-dimensional collagen matrices in terms of tensile stress and elastic modulus. © 2014 Wiley Periodicals, Inc.

Reduction of NADPH-Oxidase Activity Ameliorates the Cardiovascular Phenotype in a Mouse Model of Williams-Beuren Syndrome

PubMed Central

Campuzano, Victoria; Segura-Puimedon, Maria; Terrado, Verena; Sánchez-Rodríguez, Carolina; Coustets, Mathilde; Menacho-Márquez, Mauricio; Nevado, Julián; Bustelo, Xosé R.; Francke, Uta; Pérez-Jurado, Luis A.

2012-01-01

A hallmark feature of Williams-Beuren Syndrome (WBS) is a generalized arteriopathy due to elastin deficiency, presenting as stenoses of medium and large arteries and leading to hypertension and other cardiovascular complications. Deletion of a functional NCF1 gene copy has been shown to protect a proportion of WBS patients against hypertension, likely through reduced NADPH-oxidase (NOX)–mediated oxidative stress. DD mice, carrying a 0.67 Mb heterozygous deletion including the Eln gene, presented with a generalized arteriopathy, hypertension, and cardiac hypertrophy, associated with elevated angiotensin II (angII), oxidative stress parameters, and Ncf1 expression. Genetic (by crossing with Ncf1 mutant) and/or pharmacological (with ang II type 1 receptor blocker, losartan, or NOX inhibitor apocynin) reduction of NOX activity controlled hormonal and biochemical parameters in DD mice, resulting in normalized blood pressure and improved cardiovascular histology. We provide strong evidence for implication of the redox system in the pathophysiology of the cardiovascular disease in a mouse model of WBS. The phenotype of these mice can be ameliorated by either genetic or pharmacological intervention reducing NOX activity, likely through reduced angII–mediated oxidative stress. Therefore, anti-NOX therapy merits evaluation to prevent the potentially serious cardiovascular complications of WBS, as well as in other cardiovascular disorders mediated by similar pathogenic mechanism. PMID:22319452

Remodeling of Aorta Extracellular Matrix as a Result of Transient High Oxygen Exposure in Newborn Rats: Implication for Arterial Rigidity and Hypertension Risk

PubMed Central

Castro, Michele M.; Cloutier, Anik; Bertagnolli, Mariane; Sartelet, Hervé; Germain, Nathalie; Comte, Blandine; Schulz, Richard; DeBlois, Denis; Nuyt, Anne Monique

2014-01-01

Neonatal high-oxygen exposure leads to elevated blood pressure, microvascular rarefaction, vascular dysfunction and arterial (aorta) rigidity in adult rats. Whether structural changes are present in the matrix of aorta wall is unknown. Considering that elastin synthesis peaks in late fetal life in humans, and early postnatal life in rodents, we postulated that transient neonatal high-oxygen exposure can trigger premature vascular remodelling. Sprague Dawley rat pups were exposed from days 3 to 10 after birth to 80% oxygen (vs. room air control) and were studied at 4 weeks. Blood pressure and vasomotor response of the aorta to angiotensin II and to the acetylcholine analogue carbachol were not different between groups. Vascular superoxide anion production was similar between groups. There was no difference between groups in aortic cross sectional area, smooth muscle cell number or media/lumen ratio. In oxygen-exposed rats, aorta elastin/collagen content ratio was significantly decreased, the expression of elastinolytic cathepsin S was increased whereas collagenolytic cathepsin K was decreased. By immunofluorescence we observed an increase in MMP-2 and TIMP-1 staining in aortas of oxygen-exposed rats whereas TIMP-2 staining was reduced, indicating a shift in the balance towards degradation of the extra-cellular matrix and increased deposition of collagen. There was no significant difference in MMP-2 activity between groups as determined by gelatin zymography. Overall, these findings indicate that transient neonatal high oxygen exposure leads to vascular wall alterations (decreased elastin/collagen ratio and a shift in the balance towards increased deposition of collagen) which are associated with increased rigidity. Importantly, these changes are present prior to the elevation of blood pressure and vascular dysfunction in this model, and may therefore be contributory. PMID:24743169

Topically delivered dissolved oxygen reduces inflammation and positively influences structural proteins in healthy intact human skin.

PubMed

Kellar, Robert S; Audet, Robert G; Roe, David F; Rheins, Lawrence A; Draelos, Zoe Diana

2013-06-01

As oxygen is essential for wound healing and there is limited diffusion across the stratum corneum into the epidermis, we wanted to evaluate whether the topical delivery of a total dissolved oxygen in dressing form on intact human subject skin would improve clinical and histologic skin functioning. Fifty normal, healthy subjects completed a pilot clinical evaluation to assess the efficacy and tolerability of a dissolved oxygen dressing (OxygeneSys™-Continuous) to improve the health and appearance of intact skin. Clinical analysis was performed on 50 subjects; histological and gene expression analysis was performed on 12 of the 50 subjects to assess the effect of the dissolved oxygen dressing. Clinical data demonstrate that the dressing is well tolerated, and several measures of skin health and integrity showed improvements compared with a control dressing site. Skin hydration measurements showed a statistically significant increase in skin hydration at 0-4, 4-8, and 0-8 weeks (P < 0.05 at each time point). The blinded clinical investigator's grading of desquamation, roughness, and skin texture show significant decreases from baseline to the 8-week time point (P < 0.05). The dressings were removed prior to the blinded clinical investigator's grading. These data were supported by the histological and gene expression studies, which showed a general reduction in inflammatory response markers and transcription products (IL-6, IL-8, TNF-alpha, MMP-1, and MMP-12), while facilitating a general increase in structural skin proteins (collagen I, elastin, and filaggrin). Additionally, p53 signals from biopsy samples support the clinical investigator's observations of no safety concerns. The data from this study demonstrate that the dressing has no deleterious effects and stimulates beneficial effects on intact, nonwounded skin. © 2013 Wiley Periodicals, Inc.

Deregulation of versican and elastin binding protein in solar elastosis.

PubMed

Knott, Anja; Reuschlein, Katja; Lucius, Ralph; Stäb, Franz; Wenck, Horst; Gallinat, Stefan

2009-04-01

Several changes in skin appearance including loss of elasticity and wrinkle formation are associated with alterations in the composition of the dermal extracellular matrix. They are induced by intrinsic aging or by environmental factors such as UV light referred to as photoaging. A general characteristic in the histology of photoaged skin is the accumulation of elastotic material suggesting impaired formation and/or massive breakdown of elastic fibres. In order to shed light on some of the underlying mechanisms we tracked two of the major players in elastic fibre formation in different skin conditions: EBP (elastin binding protein), a regulator of elastic fibre assembly and VER (versican), a component of functional elastic fibres as well as non-functional elastotic material. Using quantitative RT-PCR on skin biopsies we found that the expression levels of VER and EBP were unaltered during intrinsic skin aging. Upon acute UV stress however, VER and EBP showed different regulation patterns: VER mRNA increased after 6 h and was further up-regulated until 24 h. The EBP mRNA by contrast was reduced after 6 h but showed massive induction at 24 h after acute UV stress. In chronically sun-exposed skin, VER protein was accumulated similar to elastotic material in the extracellular space, whereas its mRNA level was consistently reduced compared to sun-protected skin. The EBP mRNA by contrast showed slightly increased expression levels in the sun-exposed area compared to its sun-protected counterpart. Based on these data we propose a model which may help to explain parts of the mechanisms leading to the formation of elastotic masses. We further hypothesize that the presence of elastotic material triggers some yet unknown feedback mechanism(s) resulting in altered expression patterns of VER and EBP in chronically sun-exposed skin.

Elastin cross-linking in the skin from patients with amyotrophic lateral sclerosis

NASA Technical Reports Server (NTRS)

Ono, S.; Yamauchi, M.

1994-01-01

Two cross-links unique to elastin, desmosine and isodesmosine were measured and compared in skin tissue (left upper arm) from 10 patients with amyotrophic lateral sclerosis (ALS) and from seven age-matched controls. The contents of desmosine and isodesmosine were significantly decreased (p < 0.01 and p < 0.01, respectively) in patients with ALS compared with those of controls, and were negatively and significantly associated with duration of illness in ALS patients (r = -0.77, p < 0.01 and r = -0.65, p < 0.05, respectively). The decline in skin desmosine and isodesmosine is more rapid in ALS than in normal ageing. Thus cross-linking of skin elastin is affected in ALS.

Tissue factor activity and ECM-related gene expression in human aortic endothelial cells grown on electrospun biohybrid scaffolds.

PubMed

Han, Jingjia; Gerstenhaber, Jonathan A; Lazarovici, Philip; Lelkes, Peter I

2013-05-13

All blood vessels are lined with a quiescent endothelium, which aids in regulating regular blood flow and avoiding thrombus formation. Current attempts at replacing diseased blood vessels frequently fail due to the intrinsic thrombogenicity of the materials used as vascular grafts. In extending our previous work where we introduced a new candidate scaffolds for vascular grafts electrospun from a blend solution of PLGA, gelatin, and elastin (PGE), this study aimed to evaluate the potential of PGE scaffolds to support nonthrombogenic monolayers of primary isolates of human aortic endothelial cells (HAECs), as assessed by a combination of biochemical, molecular, and bioinformatics-based analyses. After 24 h of culture on 3-D fibrous PGE scaffolds, HAECs formed a confluent, nonthrombogenic, and physiologically competent monolayer, as assessed by tissue factor (TF) gene expression and protein activity assays. The levels of TF mRNA/protein activity in HAECs grown on PGE scaffolds were similar to those on gelatin or collagen IV-coated 2-D surfaces. In addition, bioinformatics-based analysis of a focused microarray containing 84 ECM-related cDNA probes demonstrated that HAECs essentially expressed a histotypic ECM-related "transcriptome" on PGE scaffolds, where cells were more quiescent than cells cultured on 2-D coverslips coated with gelatin (a well-known "inert" substrate for conventional EC culture), but less so than on 2-D PGE films. These data suggest an important role for nanorough substrates (PGE films) in passivating endothelial cells and confirm the crucial effect of substrate composition in this process. Principal component analysis of microarray data on the above substrates (including collagen IV) implied that substrate composition plays a greater role than surface topography in affecting the endothelial ECM-related "transcriptome". Taken together, our findings suggest that electrospun PGE scaffolds are potentially suitable for application in small diameter vascular tissue engineering.

Decrease of reactive oxygen species-related biomarkers in the tissue-mimic 3D spheroid culture of human lung cells exposed to zinc oxide nanoparticles.

PubMed

Kim, Eunjoo; Jeon, Won Bae; Kim, Soonhyun; Lee, Soo-Keun

2014-05-01

Common 2-dimensional (2D) cell cultures do not adequately represent cell-cell and cell-matrix signaling and substantially different diffusion/transport pathways. To obtain tissue-mimic information on nanoparticle toxicity from in vitro cell tests, we used a 3-dimensional (3D) culture of human lung cells (A549) prepared with elastin-like peptides modified with an arginine-glycine-aspartate motif. The 3D cells showed different cellular phenotypes, gene expression profiles, and functionalities compared to the 2D cultured cells. In gene array analysis, 3D cells displayed the induced extracellular matrix (ECM)-related biological functions such as cell-to-cell signaling and interaction, cellular function and maintenance, connective tissue development and function, molecular transport, and tissue morphology. Additionally, the expression of ECM-related molecules, such as laminin, fibronectin, and insulin-like growth factor binding protein 3 (IGFBP3), was simultaneously induced at both mRNA and protein levels. When 0.08-50 microg/ml zinc oxide nanoparticles (ZnO-NPs) were administered to 2D and 3D cells, the cell proliferation was not significantly changed. The level of molecular markers for oxidative stress, such as superoxide dismutase (SOD), Bcl-2, ATP synthase, and Complex IV (cytochrome C oxidase), was significantly reduced in 2D culture when exposed to 10 microg/ml ZnO-NPs, but no significant decrease was detected in 3D culture when exposed to the same concentration of ZnO-NPs. In conclusion, the tissue-mimic phenotype and functionality of 3D cells could be achieved through the elevated expression of ECM components. The 3D cells were expected to help to better predict the nanotoxicity of ZnO-NPs at tissue-level by increased cell-cell and cell-ECM adhesion and signaling. The tissue-mimic morphology would also be useful to simulate the diffusion/transport of the nanoparticles in vitro.

All-trans retinoic acid results in irregular repair of septa and fails to inhibit proinflammatory macrophages.

PubMed

Seifart, C; Muyal, J P; Plagens, A; Yildirim, A Ö; Kohse, K; Grau, V; Sandu, S; Reinke, C; Tschernig, T; Vogelmeier, C; Fehrenbach, H

2011-08-01

All-trans retinoic acid (ATRA) is controversially discussed in emphysema therapy. We re-evaluated ATRA in the elastase model and hypothesised that beneficial effects should be reflected by increased alveolar surface area, elastin expression and downregulation of inflammatory mediators and matrix metalloproteinases (MMPs). Emphysema was induced by porcine pancreatic elastase versus saline in Sprague-Dawley rats. On days 26-37, rats received daily intraperitoneal injections with ATRA (500 μg · kg(-1) body weight) versus olive oil. Lungs were removed at day 38. Rat alveolar epithelial L2 cells were incubated with/without elastase followed by ATRA- or vehicle-treatment, respectively. ATRA only partially ameliorated structural defects. Alveolar walls exhibited irregular architecture: increased arithmetic mean thickness, reduction in surface coverage by alveolar epithelial cells type II. ATRA only partially restored reduced soluble elastin. It tended to increase the ratio of ED1(+):ED2(+) macrophages. Bronchoalveolar lavage (BAL) cells exhibited a proinflammatory state and high expression of interleukin-1β, cytokine-induced neutrophil chemoattractant-1, tumour necrosis factor-α, nuclear factor-κB, MMP-2, MMP-9, MMP-12, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in emphysema, with ATRA exerting only few effects. MMP-7 was highly induced by ATRA in healthy but not in emphysematous lungs. ATRA reduced both MMP-2 and TIMP-1 activity in BAL fluid of emphysematous lungs. ATRA-therapy may bear the risk of unwanted side-effects on alveolar septal architecture in emphysematous lungs.

Sequence-Independent Cloning and Post-Translational Modification of Repetitive Protein Polymers through Sortase and Sfp-Mediated Enzymatic Ligation.

PubMed

Ott, Wolfgang; Nicolaus, Thomas; Gaub, Hermann E; Nash, Michael A

2016-04-11

Repetitive protein-based polymers are important for many applications in biotechnology and biomaterials development. Here we describe the sequential additive ligation of highly repetitive DNA sequences, their assembly into genes encoding protein-polymers with precisely tunable lengths and compositions, and their end-specific post-translational modification with organic dyes and fluorescent protein domains. Our new Golden Gate-based cloning approach relies on incorporation of only type IIS BsaI restriction enzyme recognition sites using PCR, which allowed us to install ybbR-peptide tags, Sortase c-tags, and cysteine residues onto either end of the repetitive gene polymers without leaving residual cloning scars. The assembled genes were expressed in Escherichia coli and purified using inverse transition cycling (ITC). Characterization by cloud point spectrophotometry, and denaturing polyacrylamide gel electrophoresis with fluorescence detection confirmed successful phosphopantetheinyl transferase (Sfp)-mediated post-translational N-terminal labeling of the protein-polymers with a coenzyme A-647 dye (CoA-647) and simultaneous sortase-mediated C-terminal labeling with a GFP domain containing an N-terminal GG-motif in a one-pot reaction. In a further demonstration, we installed an N-terminal cysteine residue into an elastin-like polypeptide (ELP) that was subsequently conjugated to a single chain poly(ethylene glycol)-maleimide (PEG-maleimide) synthetic polymer, noticeably shifting the ELP cloud point. The ability to straightforwardly assemble repetitive DNA sequences encoding ELPs of precisely tunable length and to post-translationally modify them specifically at the N- and C- termini provides a versatile platform for the design and production of multifunctional smart protein-polymeric materials.

Development of Intra-Articular Drug Delivery to Alter Progression of Arthritis Following Joint Injury

DTIC Science & Technology

2013-04-01

sTNFRII in combination. The treatments were encapsulated in elastin -like polypeptide (ELP) drug depots that have been associated with a 25-fold...or both IL-1Ra and sTNFRII. The drugs were encapsulated in elastin -like polypeptide (ELP) drug depots that slowly disaggregate for prolonged IA

Measurement of the Exchange Rate of Waters of Hydration in Elastin by 2D T(2)-T(2) Correlation Nuclear Magnetic Resonance Spectroscopy.

PubMed

Sun, Cheng; Boutis, Gregory S

2011-02-28

We report on the direct measurement of the exchange rate of waters of hydration in elastin by T(2)-T(2) exchange spectroscopy. The exchange rates in bovine nuchal ligament elastin and aortic elastin at temperatures near, below and at the physiological temperature are reported. Using an Inverse Laplace Transform (ILT) algorithm, we are able to identify four components in the relaxation times. While three of the components are in good agreement with previous measurements that used multi-exponential fitting, the ILT algorithm distinguishes a fourth component having relaxation times close to that of free water and is identified as water between fibers. With the aid of scanning electron microscopy, a model is proposed allowing for the application of a two-site exchange analysis between any two components for the determination of exchange rates between reservoirs. The results of the measurements support a model (described elsewhere [1]) wherein the net entropy of bulk waters of hydration should increase upon increasing temperature in the inverse temperature transition.

Elastin in large artery stiffness and hypertension

PubMed Central

Wagenseil, Jessica E.; Mecham, Robert P.

2012-01-01

Large artery stiffness, as measured by pulse wave velocity (PWV), is correlated with high blood pressure and may be a causative factor in essential hypertension. The extracellular matrix components, specifically the mix of elastin and collagen in the vessel wall, determine the passive mechanical properties of the large arteries. Elastin is organized into elastic fibers in the wall during arterial development in a complex process that requires spatial and temporal coordination of numerous proteins. The elastic fibers last the lifetime of the organism, but are subject to proteolytic degradation and chemical alterations that change their mechanical properties. This review discusses how alterations in the amount, assembly, organization or chemical properties of the elastic fibers affect arterial stiffness and blood pressure. Strategies for encouraging or reversing alterations to the elastic fibers are addressed. Methods for determining the efficacy of these strategies, by measuring elastin amounts and arterial stiffness, are summarized. Therapies that have a direct effect on arterial stiffness through alterations to the elastic fibers in the wall may be an effective treatment for essential hypertension. PMID:22290157

Quantitative and qualitative evaluation of dermal elastin of draught horses with chronic progressive lymphoedema.

PubMed

De Cock, H E V; Van Brantegem, L; Affolter, V K; Oosterlinck, M; Ferraro, G L; Ducatelle, R

2009-01-01

Chronic progressive lymphoedema (CPL) in horses, a disease of certain draught breeds, is associated with altered elastin metabolism. The characteristic lesions are seen in the skin of the lower (distal) limbs. This study was based on horses of susceptible breeds, with and without CPL, and on horses of a non-susceptible breed. Skin samples were obtained for examination from the neck (considered a non-affected region) and from the distal limb. The skin lesions were characterized histologically and the dermal elastic fibres were evaluated morphologically and quantitatively. In all horses the mean elastin concentrations were highest in the superficial dermis, gradually decreasing in the mid-dermis and deep dermis. As compared with horses of a non-susceptible breed, affected horses had increased amounts of dermal elastin in both the distal limb and neck, while non-affected horses of a susceptible breed had decreased amounts. The findings support an earlier hypothesis that CPL of horses is a generalized disease. Reduced efficiency of the elastic network in supporting the dermal lymphatics may explain the development of CPL.

Vascular replacement using a layered elastin-collagen vascular graft in a porcine model: one week patency versus one month occlusion

PubMed Central

Koens, M J W; Krasznai, A G; Hanssen, A E J; Hendriks, T; Praster, R; Daamen, W F; van der Vliet, J A; van Kuppevelt, T H

2015-01-01

abstract A persistent clinical demand exists for a suitable arterial prosthesis. In this study, a vascular conduit mimicking the native 3-layered artery, and constructed from the extracellular matrix proteins type I collagen and elastin, was evaluated for its performance as a blood vessel equivalent. A tubular 3-layered graft (elastin-collagen-collagen) was prepared using highly purified type I collagen fibrils and elastin fibers, resembling the 3-layered native blood vessel architecture. The vascular graft was crosslinked and heparinised (37 ± 4 μg heparin/mg graft), and evaluated as a vascular graft using a porcine bilateral iliac artery model. An intra-animal comparison with clinically-used heparinised ePTFE (Propaten®) was made. Analyses included biochemical characterization, duplex scanning, (immuno)histochemistry and scanning electron microscopy. The tubular graft was easy to handle with adequate suturability. Implantation resulted in pulsating grafts without leakage. One week after implantation, both ePTFE and the natural acellular graft had 100% patencies on duplex scanning. Grafts were partially endothelialised (Von Willebrand-positive endothelium with a laminin-positive basal membrane layer). After one month, layered thrombi were found in the natural (4/4) and ePTFE graft (1/4), resulting in occlusion which in case of the natural graft is likely due to the porosity of the inner elastin layer. In vivo application of a molecularly-defined tubular graft, based on nature's matrix proteins, for vascular surgery is feasible. PMID:26060888

Targeted chelation therapy with EDTA-loaded albumin nanoparticles regresses arterial calcification without causing systemic side effects

PubMed Central

Lei, Yang; Nosoudi, Nasim; Vyavahare, Naren

2014-01-01

Background and aims Elastin-specific medial arterial calcification (MAC) is an arterial disease commonly referred as Monckeberg’s sclerosis. It causes significant arterial stiffness, and as yet, no clinical therapy exists to prevent or reverse it. We developed albumin nanoparticles (NPs) loaded with disodium ethylene diaminetetraacetic acid (EDTA) that were designed to target calcified elastic lamina when administrated by intravenous injection. Methods and Results We optimized NP size, charge, and EDTA-loading efficiency (150~200 nm, zeta potential of − 22.89 ~ − 31.72 mV, loading efficiency for EDTA ~20 %) for in vivo targeting in rats. These NPs released EDTA slowly for up to 5 days. In both ex-vivo study and in vivo study with injury-induced local abdominal aortic calcification, we showed that elastin antibody-coated and EDTA-loaded albumin NPs targeted the damaged elastic lamina while sparing healthy artery. Intravenous NP injections reversed elastin-specific MAC in rats after four injections over a 2-week period. EDTA-loaded albumin NPs did not cause the side effects observed in EDTA injection alone, such as decrease in serum calcium (Ca), increase in urine Ca, or toxicity to kidney. There was no bone loss in any treated groups. Conclusion We demonstrate that elastin antibody-coated and EDTA-loaded albumin NPs might be a promising nanoparticle therapy to reverse elastin-specific MAC and circumvent side effects associated with systemic EDTA chelation therapy. PMID:25285609

Quantification of aortic and cutaneous elastin and collagen morphology in Marfan syndrome by multiphoton microscopy.

PubMed

Cui, Jason Z; Tehrani, Arash Y; Jett, Kimberly A; Bernatchez, Pascal; van Breemen, Cornelis; Esfandiarei, Mitra

2014-09-01

In a mouse model of Marfan syndrome, conventional Verhoeff-Van Gieson staining displays severe fragmentation, disorganization and loss of the aortic elastic fiber integrity. However, this method involves chemical fixatives and staining, which may alter the native morphology of elastin and collagen. Thus far, quantitative analysis of fiber damage in aorta and skin in Marfan syndrome has not yet been explored. In this study, we have used an advanced noninvasive and label-free imaging technique, multiphoton microscopy to quantify fiber fragmentation, disorganization, and total volumetric density of aortic and cutaneous elastin and collagen in a mouse model of Marfan syndrome. Aorta and skin samples were harvested from Marfan and control mice aged 3-, 6- and 9-month. Elastin and collagen were identified based on two-photon excitation fluorescence and second-harmonic-generation signals, respectively, without exogenous label. Measurement of fiber length indicated significant fragmentation in Marfan vs. control. Fast Fourier transform algorithm analysis demonstrated markedly lower fiber organization in Marfan mice. Significantly reduced volumetric density of elastin and collagen and thinner skin dermis were observed in Marfan mice. Cutaneous content of elastic fibers and thickness of dermis in 3-month Marfan resembled those in the oldest control mice. Our findings of early signs of fiber degradation and thinning of skin dermis support the potential development of a novel non-invasive approach for early diagnosis of Marfan syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

Diversity in the organization of elastin bundles and intramembranous muscles in bat wings.

PubMed

Cheney, Jorn A; Allen, Justine J; Swartz, Sharon M

2017-04-01

Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross-polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the constituents of the skin of the wing likely plays a key role in shaping wings during flight. © 2017 Anatomical Society.

Towards an in vitro model mimicking the foreign body response: tailoring the surface properties of biomaterials to modulate extracellular matrix.

PubMed

Damanik, Febriyani F R; Rothuizen, Tonia C; van Blitterswijk, Clemens; Rotmans, Joris I; Moroni, Lorenzo

2014-09-19

Despite various studies to minimize host reaction following a biomaterial implantation, an appealing strategy in regenerative medicine is to actively use such an immune response to trigger and control tissue regeneration. We have developed an in vitro model to modulate the host response by tuning biomaterials' surface properties through surface modifications techniques as a new strategy for tissue regeneration applications. Results showed tunable surface topography, roughness, wettability, and chemistry by varying treatment type and exposure, allowing for the first time to correlate the effect of these surface properties on cell attachment, morphology, strength and proliferation, as well as proinflammatory (IL-1β, IL-6) and antiinflammatory cytokines (TGF-β1, IL-10) secreted in medium, and protein expression of collagen and elastin. Surface microstructuring, derived from chloroform partial etching, increased surface roughness and oxygen content. This resulted in enhanced cell adhesion, strength and proliferation as well as a balance of soluble factors for optimum collagen and elastin synthesis for tissue regeneration. By linking surface parameters to cell activity, we could determine the fate of the regenerated tissue to create successful soft tissue-engineered replacement.

Towards an in vitro model mimicking the foreign body response: tailoring the surface properties of biomaterials to modulate extracellular matrix

NASA Astrophysics Data System (ADS)

Damanik, Febriyani F. R.; Rothuizen, Tonia C.; van Blitterswijk, Clemens; Rotmans, Joris I.; Moroni, Lorenzo

2014-09-01

Despite various studies to minimize host reaction following a biomaterial implantation, an appealing strategy in regenerative medicine is to actively use such an immune response to trigger and control tissue regeneration. We have developed an in vitro model to modulate the host response by tuning biomaterials' surface properties through surface modifications techniques as a new strategy for tissue regeneration applications. Results showed tunable surface topography, roughness, wettability, and chemistry by varying treatment type and exposure, allowing for the first time to correlate the effect of these surface properties on cell attachment, morphology, strength and proliferation, as well as proinflammatory (IL-1β, IL-6) and antiflammatory cytokines (TGF-β1, IL-10) secreted in medium, and protein expression of collagen and elastin. Surface microstructuring, derived from chloroform partial etching, increased surface roughness and oxygen content. This resulted in enhanced cell adhesion, strength and proliferation as well as a balance of soluble factors for optimum collagen and elastin synthesis for tissue regeneration. By linking surface parameters to cell activity, we could determine the fate of the regenerated tissue to create successful soft tissue-engineered replacement.

Comparative Biology of Decellularized Lung Matrix: Implications of Species Mismatch in Regenerative Medicine

PubMed Central

Balestrini, Jenna L.; Gard, Ashley L.; Gerhold, Kristin A.; Wilcox, Elise C.; Liu, Angela; Schwan, Jonas; Le, Andrew V.; Baevova, Pavlina; Dimitrievska, Sashka; Zhao, Liping; Sundaram, Sumati; Sun, Huanxing; Rittié, Laure; Dyal, Rachel; Broekelmann, Tom J.; Mecham, Robert P.; Schwartz, Martin A.; Niklason, Laura E.; White, Eric S.

2016-01-01

Lung engineering is a promising technology, relying on re-seeding of either human or xenographic decellularized matrices with patient-derived pulmonary cells. Little is known about the species-specificity of decellularization in various models of lung regeneration, or if species dependent cell-matrix interactions exist within these systems. Therefore decellularized scaffolds were produced from rat, pig, primate and human lungs, and assessed by measuring residual DNA, mechanical properties, and key matrix proteins (collagen, elastin, glycosaminoglycans). To study intrinsic matrix biologic cues, human endothelial cells were seeded onto acellular slices and analyzed for markers of cell health and inflammation. Despite similar levels of collagen after decellularization, human and primate lungs were stiffer, contained more elastin, and retained fewer glycosaminoglycans than pig or rat lung scaffolds. Human endothelial cells seeded onto human and primate lung tissue demonstrated less expression of vascular cell adhesion molecule and activation of nuclear factor-κB compared to those seeded onto rodent or porcine tissue. Adhesion of endothelial cells was markedly enhanced on human and primate tissues. Our work suggests that species-dependent biologic cues intrinsic to lung extracellular matrix could have profound effects on attempts at lung regeneration. PMID:27344365

Mechanical factors direct mouse aortic remodelling during early maturation

PubMed Central

Le, Victoria P.; Cheng, Jeffrey K.; Kim, Jungsil; Staiculescu, Marius C.; Ficker, Shawn W.; Sheth, Saahil C.; Bhayani, Siddharth A.; Mecham, Robert P.; Yanagisawa, Hiromi; Wagenseil, Jessica E.

2015-01-01

Numerous diseases have been linked to genetic mutations that lead to reduced amounts or disorganization of arterial elastic fibres. Previous work has shown that mice with reduced amounts of elastin (Eln+/−) are able to live a normal lifespan through cardiovascular adaptations, including changes in haemodynamic stresses, arterial geometry and arterial wall mechanics. It is not known if the timeline and presence of these adaptations are consistent in other mouse models of elastic fibre disease, such as those caused by the absence of fibulin-5 expression (Fbln5−/−). Adult Fbln5−/− mice have disorganized elastic fibres, decreased arterial compliance and high blood pressure. We examined mechanical behaviour of the aorta in Fbln5−/− mice through early maturation when the elastic fibres are being assembled. We found that the physiologic circumferential stretch, stress and modulus of Fbln5−/− aorta are maintained near wild-type levels. Constitutive modelling suggests that elastin contributions to the total stress are decreased, whereas collagen contributions are increased. Understanding how collagen fibre structure and mechanics compensate for defective elastic fibres to meet the mechanical requirements of the maturing aorta may help to better understand arterial remodelling in human elastinopathies. PMID:25652465

International Congress of Biorheology (3rd) Held at the University of California, San Diego on August 28 - September 1, 1978.

DTIC Science & Technology

1979-01-30

12. Hemorheology and Hemodynamics 13. New Hypotheses in Hemorheology and Muscle Contraction 14. Bone and Cartilage 15. Tissue Space 16. Elastin...Hemodynamics 13. New Hypotheses in Hemorheology and Muscle Contraction 14. Bone and Cartilage 15. Tissue Space 16. Elastin, Collagen and Tendons 17. Clinical

Acoustic fingerprints of dye-labeled protein submicrosphere photoacoustic contrast agents

NASA Astrophysics Data System (ADS)

McDonald, Michael A.; Jankovic, Ladislav; Shahzad, Khalid; Burcher, Michael; Li, King C. P.

2009-05-01

Dye-labeled protein microspheres, submicron in size and capable of producing thermoelastically generated ultrasound in response to laser stimulation, are presented as contrast agents for photoacoustic imaging. Incident laser energy absorbed by fluorescein isothiocyanate (FITC)-labeled elastin submicrospheres results in thermoelastically generated sound production. Plotted A-line graphs reveal a distinctive morphology and a greater than two orders of magnitude increase in signal amplitude subsequent to converting FITC elastin into submicrospheres (despite a four orders of magnitude decrease in concentration). Evidence of nonlinearity and enhancement of ultrasound backscatter indicate a potential use in contrast-enhanced harmonic imaging. Photoacoustic and ultrasound imaging of FITC-elastin submicrospheres in a water-filled phantom vessel shows enhanced contrast at low concentration and clear delineation of the phantom vessel wall.

Loss of Endothelial Barrier in Marfan Mice (mgR/mgR) Results in Severe Inflammation after Adenoviral Gene Therapy

PubMed Central

Weymann, Alexander; Arif, Rawa; Weber, Antje; Zaradzki, Marcin; Richter, Karsten; Ensminger, Stephan; Robinson, Peter Nicholas; Wagner, Andreas H.; Karck, Matthias; Kallenbach, Klaus

2016-01-01

Objectives Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs). In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1) in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR) in order to reduce elastolysis. Methods We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group). Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6) were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1) or β-galactosidase (Ad.β-Gal). As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC) and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI), and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM). Results IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43), but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00). Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001). As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001). However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated Marfan aorta: Ad.hTIMP-1 p = 0.902; control Ad.β-Gal. p = 0.165). The virus-untreated and not transplanted mgR/mgR aorta revealed a significant increase of albumin diffusion through the endothelial barrier (p = 0.037). TEM analysis of adenovirus-exposed mgR/mgR aortas displayed disruption of the basement membrane and basolateral space. Conclusions Murine Marfan aortic grafts developed severe inflammation after adenoviral contact. We demonstrated that fibrillin-1 deficiency is associated with relevant dysfunction of the endothelial barrier that enables adenovirus to induce vessel-harming inflammation. Endothelial dysfunction may play a pivotal role in the development of the vascular phenotype of Marfan syndrome. PMID:26840980

Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

PubMed

Nielsen, M J; Lehmann, J; Leeming, D J; Schierwagen, R; Klein, S; Jansen, C; Strassburg, C P; Bendtsen, F; Møller, S; Sauerbruch, T; Karsdal, M A; Krag, A; Trebicka, J

2015-11-01

Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

The effect of oxidation on the mechanical response and microstructure of porcine aortas.

PubMed

Stephen, Elizabeth A; Venkatasubramaniam, Arundhathi; Good, Theresa A; Topoleski, L D Timmie

2014-09-01

Reactive oxygen species (ROS), a product of many cellular functions, has been implicated in many age-related pathophysiological processes, including cardiovascular disease. The arterial proteins collagen and elastin may also undergo structural and functional changes due to damage caused by ROS. This study examined the effect of oxidation on the mechanical response of porcine aortas and aorta elastin and the associated changes in structural protein ultrastructure as a step in exploring the role of molecular changes in structural proteins with aging on elastic artery function. We examined the change in mechanical properties of aorta samples after various oxidation times as a first step in understanding how the oxidative environment associated with aging could impact mechanical properties of arterial structural proteins. We used confocal microscopy to visualize how the microstructure of isolated elastin changed with oxidation. We find that short term oxidation of elastin isolated from aortas leads to an increase in material stiffness, but also an increase in the fiber diameter, increase in void space in the matrix, and a decrease in the fiber orientation, possibly due to fiber cross-linking. The short term effects of oxidation on arterial collagen is more complex, with increase in material stiffness seen in the collagen region of the stress stretch curve at low extents of oxidation, but not at high levels of oxidation. These results may provide insight into the relationship between oxidative damage to tissue associated with aging and disease, structure of the arterial proteins elastin and collagen, and arterial mechanical properties and function. © 2013 Wiley Periodicals, Inc.

Age-related morphological changes of the dermal matrix in human skin documented in vivo by multiphoton microscopy

NASA Astrophysics Data System (ADS)

Wang, Hequn; Shyr, Thomas; Fevola, Michael J.; Cula, Gabriela Oana; Stamatas, Georgios N.

2018-03-01

Two-photon fluorescence (TPF) and second harmonic generation (SHG) microscopy provide direct visualization of the skin dermal fibers in vivo. A typical method for analyzing TPF/SHG images involves averaging the image intensity and therefore disregarding the spatial distribution information. The goal of this study is to develop an algorithm to document age-related effects of the dermal matrix. TPF and SHG images were acquired from the upper inner arm, volar forearm, and cheek of female volunteers of two age groups: 20 to 30 and 60 to 80 years of age. The acquired images were analyzed for parameters relating to collagen and elastin fiber features, such as orientation and density. Both collagen and elastin fibers showed higher anisotropy in fiber orientation for the older group. The greatest difference in elastin fiber anisotropy between the two groups was found for the upper inner arm site. Elastin fiber density increased with age, whereas collagen fiber density decreased with age. The proposed analysis considers the spatial information inherent to the TPF and SHG images and provides additional insights into how the dermal fiber structure is affected by the aging process.

On the occurrence of polyproline II structure in elastin

NASA Astrophysics Data System (ADS)

Martino, M.; Bavoso, A.; Guantieri, V.; Coviello, A.; Tamburro, A. M.

2000-02-01

To shed light on the occurrence of the polyproline II (PP II) structure in the elastomeric protein elastin, the octapeptide sequence ALGGGALG of the N-terminal region of human elastin was studied in its monomeric and polymeric form, both in solution and in the solid state. Furthermore, the polymer poly(PG), chosen by us as an a priori reference compound for investigating the stability of PP II structure in presence of alternating proline and glycine residues along the polypeptide chain, was studied by circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Its "monomeric" form Boc-PG-OH, was also analyzed by X-ray diffraction. It was shown that, in the solid state the presence of PG or GGG sequences in polypeptide chains and even in a short peptide as Boc-PG-OH induces the acquisition of the PP II structural motif. However, in solution this conformation appears to be much more unstable even in the case of long polypeptide chains. The finding that at room temperature the PP II structure is always in equilibrium with other conformers suggests that its dynamics could also contribute to the molecular mechanism of elastin elasticity.

Role of fetal nutrient restriction and postnatal catch-up growth on structural and mechanical alterations of rat aorta.

PubMed

Gutiérrez-Arzapalo, Perla Y; Rodríguez-Rodríguez, Pilar; Ramiro-Cortijo, David; López de Pablo, Ángel L; López-Giménez, María Rosario; Condezo-Hoyos, Luis; Greenwald, Stephen E; González, Maria Del Carmen; Arribas, Silvia M

2017-12-26

Intrauterine growth restriction (IUGR), induced by maternal undernutrition, leads to impaired aortic development. This is followed by hypertrophic remodelling associated with accelerated growth during lactation. Fetal nutrient restriction is associated with increased aortic compliance at birth and at weaning, but not in adult animals. This mechanical alteration may be related to a decreased perinatal collagen deposition. Aortic elastin scaffolds purified from young male and female IUGR animals also exhibit increased compliance, only maintained in adult IUGR females. These mechanical alterations may be related to differences in elastin deposition and remodelling. Fetal undernutrition induces similar aortic structural and mechanical alterations in young male and female rats. Our data argue against an early mechanical cause for the sex differences in hypertension development induced by maternal undernutrition. However, the larger compliance of elastin in adult IUGR females may contribute to the maintenance of a normal blood pressure level. Fetal undernutrition programmes hypertension development, males being more susceptible. Deficient fetal elastogenesis and vascular growth is a possible mechanism. We investigated the role of aortic mechanical alterations in a rat model of hypertension programming, evaluating changes at birth, weaning and adulthood. Dams were fed ad libitum (Control) or 50% of control intake during the second half of gestation (maternal undernutrition, MUN). Offspring aged 3 days, 21 days and 6 months were studied. Blood pressure was evaluated in vivo. In the thoracic aorta we assessed gross structure, mechanical properties (intact and purified elastin), collagen and elastin content and internal elastic lamina (IEL) organization. Only adult MUN males developed hypertension (systolic blood pressure: MUN males  = 176.6 ± 5.6 mmHg; Control males  = 136.1 ± 4.9 mmHg). At birth MUN rats were lighter, with smaller aortic cross-sectional area (MUN males  = (1.51 ± 0.08) × 10 5  μm 2 , Control males  = (2.8 ± 0.04) × 10 5  μm 2 ); during lactation MUN males and females exhibited catch-up growth and aortic hypertrophy (MUN males  = (14.5 ± 0.5) × 10 5  μm 2 , Control males  = (10.4 ± 0.9) × 10 5  μm 2 ), maintained until adulthood. MUN aortas were more compliant until weaning (functional stiffness: MUN males  = 1.0 ± 0.04; Control males  = 1.3 ± 0.03), containing less collagen with larger IEL fenestrae, returning to normal in adulthood. Purified elastin from young MUN offspring was more compliant in both sexes; only MUN adult females maintained larger elastin compliance (slope: MUN females  = 24.1 ± 1.9; Control females  = 33.3 ± 2.8). Fetal undernutrition induces deficient aortic development followed by hypertrophic remodelling and larger aortic compliance in the perinatal period, with similar alterations in collagen and elastin in both sexes. The observed alterations argue against an initial mechanical cause for sex differences in hypertension development. However, the maintenance of high elastin compliance in adult females might protect them against blood pressure rise. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Dietary Foeniculum vulgare Mill extract attenuated UVB irradiation-induced skin photoaging by activating of Nrf2 and inhibiting MAPK pathways.

PubMed

Sun, Zhengwang; Park, Sang Yong; Hwang, Eunson; Park, Bom; Seo, Seul A; Cho, Jin-Gyeong; Zhang, Mengyang; Yi, Tae-Hoo

2016-11-15

Foeniculum vulgare Mill (FV) has long been prescribed in traditional medicine due to its antioxidant anti-inflammatory properties. However, little research has been done on the use of FV to alleviate changes in UVB-induced photoaging PURPOSE: This study was to investigate the photoprotective effects and mechanism of FV in vitro and in vivo. The anti-photoaging effect of FV was assessed in normal human dermal fibroblasts (NHDFs) in vitro. The secretion of reactive oxygen species (ROS), lactate dehydrogenase (LDH), GSH, matrix metalloproteinases (MMPs), procollagen type I, IL-6 and transforming growth factor-β1 (TGF-β1) were measured by kits. Additionally, the level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), p-ERK and p38 were evaluated by western blotting. In vivo, H&E and Masson's trichrome staining were employed. The expression of MMP-1, procollagen type I, TGF-β1 and elastin were measured by western blot. FV significantly increased the production of collagen, elastin and TGF-β1 levels, while blocked matrix metalloproteinases (MMPs) production in UVB irradiation induced hairless mice, which were consistent with the result in NHDFs. Furthermore, FV dose-dependently decreased the production of ROS and LDH by promoting the nuclear amount of Nrf2 and enhancing the expression of cytoprotective antioxidants such as GSH. FV also significantly quenched UVB-induced phosphorylation of ERK and p38 in NHDFs. Our results indicate that FV is a potential botanical agent for the treatment of skin damage induced by UV irradiation. Copyright © 2016 Elsevier GmbH. All rights reserved.

Corneal stroma microfibrils.

PubMed

Hanlon, Samuel D; Behzad, Ali R; Sakai, Lynn Y; Burns, Alan R

2015-03-01

Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (∼10 nm diameter). Immunogold evidence clearly identified these fibrils as fibrillin EFMBs and EFMBs were also observed with TEM (without immunogold) in adult mammals of several species. Evidence of the presence of EFMBs in adult corneas will hopefully pique an interest in further studies that will ultimately improve our understanding of the cornea's biomechanical properties and its capacity to repair. Copyright © 2015 Elsevier Ltd. All rights reserved.

Corneal Stroma Microfibrils

PubMed Central

Hanlon, Samuel D.; Behzad, Ali R.; Sakai, Lynn Y.; Burns, Alan R.

2015-01-01

Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (∼10nm diameter). Immunogold evidence clearly identified these fibrils as fibrillin EFMBs and EFMBs were also observed with TEM (without immunogold) in adult mammals of several species. Evidence of the presence of EFMBs in adult corneas will hopefully pique an interest in further studies that will ultimately improve our understanding of the cornea's biomechanical properties and its capacity to repair. PMID:25613072

Mild aerobic exercise blocks elastin fiber fragmentation and aortic dilatation in a mouse model of Marfan syndrome associated aortic aneurysm.

PubMed

Gibson, Christine; Nielsen, Cory; Alex, Ramona; Cooper, Kimbal; Farney, Michael; Gaufin, Douglas; Cui, Jason Z; van Breemen, Cornelis; Broderick, Tom L; Vallejo-Elias, Johana; Esfandiarei, Mitra

2017-07-01

Regular low-impact physical activity is generally allowed in patients with Marfan syndrome, a connective tissue disorder caused by heterozygous mutations in the fibrillin-1 gene. However, being above average in height encourages young adults with this syndrome to engage in high-intensity contact sports, which unfortunately increases the risk for aortic aneurysm and rupture, the leading cause of death in Marfan syndrome. In this study, we investigated the effects of voluntary (cage-wheel) or forced (treadmill) aerobic exercise at different intensities on aortic function and structure in a mouse model of Marfan syndrome. Four-week-old Marfan and wild-type mice were subjected to voluntary and forced exercise regimens or sedentary lifestyle for 5 mo. Thoracic aortic tissue was isolated and subjected to structural and functional studies. Our data showed that exercise improved aortic wall structure and function in Marfan mice and that the beneficial effect was biphasic, with an optimum at low intensity exercise (55-65% V̇o 2max ) and tapering off at a higher intensity of exercise (85% V̇o 2max ). The mechanism underlying the reduced elastin fragmentation in Marfan mice involved reduction of the expression of matrix metalloproteinases 2 and 9 within the aortic wall. These findings present the first evidence of potential beneficial effects of mild exercise on the structural integrity of the aortic wall in Marfan syndrome associated aneurysm. Our finding that moderate, but not strenuous, exercise protects aortic structure and function in a mouse model of Marfan syndrome could have important implications for the medical care of young Marfan patients. NEW & NOTEWORTHY The present study provides conclusive scientific evidence that daily exercise can improve aortic health in a mouse model of Marfan syndrome associated aortic aneurysm, and it establishes the threshold for the exercise intensity beyond which exercise may not be as protective. These findings establish a platform for a new focus on promoting regular exercise in Marfan patients at an optimum intensity and create a paradigm shift in clinical care of Marfan patients suffering from aortic aneurysm complications. Copyright © 2017 the American Physiological Society.

Assessment of clinical scoring systems for the diagnosis of Williams-Beuren syndrome.

PubMed

Leme, D E S; Souza, D H; Mercado, G; Pastene, E; Dias, A; Moretti-Ferreira, D

2013-09-04

Williams-Beuren syndrome (WBS) is a genetic disorder characterized by physical and intellectual developmental delay, associated with congenital heart disease and facial dysmorphism. WBS is caused by a microdeletion on chromosome 7 (7q11.23), which encompasses the elastin (ELN) gene and about 27 other genes. The gold standard for WBS laboratory diagnosis is FISH (fluorescence in situ hybridization), which is very costly. As a possible alternative, we investigated the accuracy of three clinical diagnostic scoring systems in 250 patients with WBS diagnosed by FISH. We concluded that all three systems could be used for the clinical diagnosis of WBS, but they all gave a low percentage of false-positive (6.0-9.2%) and false-negative (0.8-4.0%) results. Therefore, their use should be associated with FISH testing.

Hydrophobic drug-triggered self-assembly of nanoparticles from silk-elastin-like protein polymers for drug delivery.

PubMed

Xia, Xiao-Xia; Wang, Ming; Lin, Yinan; Xu, Qiaobing; Kaplan, David L

2014-03-10

Silk-elastin-like protein polymers (SELPs) combine the mechanical and biological properties of silk and elastin. These properties have led to the development of various SELP-based materials for drug delivery. However, SELPs have rarely been developed into nanoparticles, partially due to the complicated fabrication procedures, nor assessed for potential as an anticancer drug delivery system. We have recently constructed a series of SELPs (SE8Y, S2E8Y, and S4E8Y) with various ratios of silk to elastin blocks and described their capacity to form micellar-like nanoparticles upon thermal triggering. In this study, we demonstrate that doxorubicin, a hydrophobic antitumor drug, can efficiently trigger the self-assembly of SE8Y (SELPs with silk to elastin ratio of 1:8) into uniform micellar-like nanoparticles. The drug can be loaded in the SE8Y nanoparticles with an efficiency around 6.5% (65 ng doxorubicin/μg SE8Y), S2E8Y with 6%, and S4E8Y with 4%, respectively. In vitro studies with HeLa cell lines demonstrate that the protein polymers are not cytotoxic (IC50 > 200 μg/mL), while the doxorubicin-loaded SE8Y nanoparticles showed a 1.8-fold higher cytotoxicity than the free drug. Confocal laser scanning microscopy (CLSM) and flow cytometry indicate significant uptake of the SE8Y nanoparticles by the cells and suggest internalization of the nanoparticles through endocytosis. This study provides an all-aqueous, facile method to prepare nanoscale, drug-loaded SELPs packages with potential for tumor cell treatments.

Qualitative and quantitative assessment of collagen and elastin in annulus fibrosus of the physiologic and scoliotic intervertebral discs.

PubMed

Kobielarz, Magdalena; Szotek, Sylwia; Głowacki, Maciej; Dawidowicz, Joanna; Pezowicz, Celina

2016-09-01

The biophysical properties of the annulus fibrosus of the intervertebral disc are determined by collagen and elastin fibres. The progression of scoliosis is accompanied by a number of pathological changes concerning these structural proteins. This is a major cause of dysfunction of the intervertebral disc. The object of the study were annulus fibrosus samples excised from intervertebral discs of healthy subjects and patients treated surgically for scoliosis in the thoracolumbar or lumbar spine. The research material was subjected to structural analysis by light microscopy and quantitative analysis of the content of collagen types I, II, III and IV as well as elastin by immunoenzymatic test (ELISA). A statistical analysis was conducted to assess the impact of the sampling site (Mann-Whitney test, α=0.05) and scoliosis (Wilcoxon matched pairs test, α=0.05) on the obtained results. The microscopic studies conducted on scoliotic annulus fibrosus showed a significant architectural distortion of collagen and elastin fibres. Quantitative biochemical assays demonstrated region-dependent distribution of only collagen types I and II in the case of healthy intervertebral discs whereas in the case of scoliotic discs region-dependent distribution concerned all examined proteins of the extracellular matrix. Comparison of scoliotic and healthy annulus fibrosus revealed a significant decrease in the content of collagen type I and elastin as well as a slight increase in the proportion of collagen types III and IV. The content of collagen type II did not differ significantly between both groups. The observed anomalies are a manifestation of degenerative changes affecting annulus fibrosus of the intervertebral disc in patients suffering from scoliosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Conformational dynamics of minimal elastin-like polypeptides: the role of proline revealed by molecular dynamics and nuclear magnetic resonance.

PubMed

Glaves, Rachel; Baer, Marcel; Schreiner, Eduard; Stoll, Raphael; Marx, Dominik

2008-12-22

Previous molecular dynamics studies of the elastin-like peptide (ELP) GVG(VPGVG) predict that this ELP undergoes a conformational transition from an open to a more compact closed state upon an increase in temperature. These structural changes occurring in this minimal elastin model at the so-called inverse temperature transition (ITT), which takes place when elastin is heated to temperatures of about 20-40 (omicron)C, are investigated further in this work by means of a combined theoretical and experimental approach. To do this, additional extensive classical molecular dynamics (MD) simulations of the capped octapeptide are carried out, analyzed, and compared to data obtained from homonuclear magnetic resonance (NMR) spectroscopy of the same octapeptide. Moreover, in the previous simulations, the proline residue in the ELP is found to act as a hinge, thereby allowing for the large-amplitude opening and closing conformational motion of the ITT. To explore the role of proline in such elastin repeating units, a point mutant (P5I), which replaces the proline residue with an isoleucine residue, is also investigated using the aforementioned theoretical and experimental techniques. The results show that the site-directed mutation completely alters the properties of this ELP, thus confirming the importance of the highly conserved proline residue in the ITT. Furthermore, a correlation between the two different methods employed is seen. Both methods predict the mutant ELP to be present in an unstructured form and the wild type ELP to have a beta-turn-like structure. Finally, the role of the peptidyl cis to trans isomerization of the proline hinge is assessed in detail.

Spontaneous aortic dissecting hematoma in two dogs.

PubMed

Boulineau, Theresa Marie; Andrews-Jones, Lydia; Van Alstine, William

2005-09-01

This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation.

Applications of elastin-like polypeptides in drug delivery

PubMed Central

MacEwan, Sarah R; Chilkoti, Ashutosh

2014-01-01

Elastin-like polypeptides (ELPs) are biopolymers inspired by human elastin. Their lower critical solution temperature phase transition behavior and biocompatibility make them useful materials for stimulus-responsive applications in biological environments. Due to their genetically encoded design and recombinant synthesis, the sequence and size of ELPs can be exactly defined. These design parameters control the structure and function of the ELP with a precision that is unmatched by synthetic polymers. Due to these attributes, ELPs have been used extensively for drug delivery in a variety of different embodiments—as soluble macromolecular carriers, self-assembled nanoparticles, cross-linked microparticles, or thermally coacervated depots. These ELP systems have been used to deliver biologic therapeutics, radionuclides, and small molecule drugs to a variety of anatomical sites for the treatment of diseases including cancer, type 2 diabetes, osteoarthritis, and neuroinflammation. PMID:24979207

Elastic fibers in human skin: quantitation of elastic fibers by computerized digital image analyses and determination of elastin by radioimmunoassay of desmosine.

PubMed

Uitto, J; Paul, J L; Brockley, K; Pearce, R H; Clark, J G

1983-10-01

The elastic fibers in the skin and other organs can be affected in several disease processes. In this study, we have developed morphometric techniques that allow accurate quantitation of the elastic fibers in punch biopsy specimens of skin. In this procedure, the elastic fibers, visualized by elastin-specific stains, are examined through a camera unit attached to the microscope. The black and white images sensing various gray levels are then converted to binary images after selecting a threshold with an analog threshold selection device. The binary images are digitized and the data analyzed by a computer program designed to express the properties of the image, thus allowing determination of the volume fraction occupied by the elastic fibers. As an independent measure of the elastic fibers, alternate tissue sections were used for assay of desmosine, an elastin-specific cross-link compound, by a radioimmunoassay. The clinical applicability of the computerized morphometric analyses was tested by examining the elastic fibers in the skin of five patients with pseudoxanthoma elasticum or Buschke-Ollendorff syndrome. In the skin of 10 healthy control subjects, the elastic fibers occupied 2.1 +/- 1.1% (mean +/- SD) of the dermis. The volume fractions occupied by the elastic fibers in the lesions of pseudoxanthoma elasticum or Buschke-Ollendorff syndrome were increased as much as 6-fold, whereas the values in the unaffected areas of the skin in the same patients were within normal limits. A significant correlation between the volume fraction of elastic fibers, determined by computerized morphometric analyses, and the concentration of desmosine, quantitated by radioimmunoassay, was noted in the total material. These results demonstrate that computerized morphometric techniques are helpful in characterizing disease processes affecting skin. This methodology should also be applicable to other tissues that contain elastic fibers and that are affected in various heritable and acquired diseases.

Three dimensional microstructural network of elastin, collagen, and cells in Achilles tendons.

PubMed

Pang, Xin; Wu, Jian-Ping; Allison, Garry T; Xu, Jiake; Rubenson, Jonas; Zheng, Ming-Hao; Lloyd, David G; Gardiner, Bruce; Wang, Allan; Kirk, Thomas Brett

2017-06-01

Similar to most biological tissues, the biomechanical, and functional characteristics of the Achilles tendon are closely related to its composition and microstructure. It is commonly reported that type I collagen is the predominant component of tendons and is mainly responsible for the tissue's function. Although elastin has been found in varying proportions in other connective tissues, previous studies report that tendons contain very small quantities of elastin. However, the morphology and the microstructural relationship among the elastic fibres, collagen, and cells in tendon tissue have not been well examined. We hypothesize the elastic fibres, as another fibrillar component in the extracellular matrix, have a unique role in mechanical function and microstructural arrangement in Achilles tendons. It has been shown that elastic fibres present a close connection with the tenocytes. The close relationship of the three components has been revealed as a distinct, integrated and complex microstructural network. Notably, a "spiral" structure within fibril bundles in Achilles tendons was observed in some samples in specialized regions. This study substantiates the hierarchical system of the spatial microstructure of tendon, including the mapping of collagen, elastin and tenocytes, with 3-dimensional confocal images. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1203-1214, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility.

PubMed

Le, Duc H T; Tsutsui, Yoko; Sugawara-Narutaki, Ayae; Yukawa, Hiroshi; Baba, Yoshinobu; Ohtsuki, Chikara

2017-09-01

We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and β-sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2475-2484, 2017. © 2017 Wiley Periodicals, Inc.

Multiscale mechanical integrity of human supraspinatus tendon in shear after elastin depletion.

PubMed

Fang, Fei; Lake, Spencer P

2016-10-01

Human supraspinatus tendon (SST) exhibits region-specific nonlinear mechanical properties under tension, which have been attributed to its complex multiaxial physiological loading environment. However, the mechanical response and underlying multiscale mechanism regulating SST behavior under other loading scenarios are poorly understood. Furthermore, little is known about the contribution of elastin to tendon mechanics. We hypothesized that (1) SST exhibits region-specific shear mechanical properties, (2) fiber sliding is the predominant mode of local matrix deformation in SST in shear, and (3) elastin helps maintain SST mechanical integrity by facilitating force transfer among collagen fibers. Through the use of biomechanical testing and multiphoton microscopy, we measured the multiscale mechanical behavior of human SST in shear before and after elastase treatment. Three distinct SST regions showed similar stresses and microscale deformation. Collagen fiber reorganization and sliding were physical mechanisms observed as the SST response to shear loading. Measures of microscale deformation were highly variable, likely due to a high degree of extracellular matrix heterogeneity. After elastase treatment, tendon exhibited significantly decreased stresses under shear loading, particularly at low strains. These results show that elastin contributes to tendon mechanics in shear, further complementing our understanding of multiscale tendon structure-function relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a nonlinear fiber-optic spectrometer for human lung tissue exploration

PubMed Central

Peyrot, Donald A.; Lefort, Claire; Steffenhagen, Marie; Mansuryan, Tigran; Ducourthial, Guillaume; Abi-Haidar, Darine; Sandeau, Nicolas; Vever-Bizet, Christine; Kruglik, Sergei G.; Thiberville, Luc; Louradour, Frédéric; Bourg-Heckly, Geneviève

2012-01-01

Several major lung pathologies are characterized by early modifications of the extracellular matrix (ECM) fibrillar collagen and elastin network. We report here the development of a nonlinear fiber-optic spectrometer, compatible with an endoscopic use, primarily intended for the recording of second-harmonic generation (SHG) signal of collagen and two-photon excited fluorescence (2PEF) of both collagen and elastin. Fiber dispersion is accurately compensated by the use of a specific grism-pair stretcher, allowing laser pulse temporal width around 70 fs and excitation wavelength tunability from 790 to 900 nm. This spectrometer was used to investigate the excitation wavelength dependence (from 800 to 870 nm) of SHG and 2PEF spectra originating from ex vivo human lung tissue samples. The results were compared with spectral responses of collagen gel and elastin powder reference samples and also with data obtained using standard nonlinear microspectroscopy. The excitation-wavelength-tunable nonlinear fiber-optic spectrometer presented in this study allows performing nonlinear spectroscopy of human lung tissue ECM through the elastin 2PEF and the collagen SHG signals. This work opens the way to tunable excitation nonlinear endomicroscopy based on both distal scanning of a single optical fiber and proximal scanning of a fiber-optic bundle. PMID:22567579

One-stage Reconstruction of Soft Tissue Defects with the Sandwich Technique: Collagen-elastin Dermal Template and Skin Grafts

PubMed Central

Wollina, Uwe

2011-01-01

Background: A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome. Objective: The objective was to evaluate a sandwich technique combining the dermal collagen–elastin matrix with skin grafts in a one-stage procedure. Materials and Methods: Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen–elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ‘sandwich’ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy. Results: The size of defects was ≤875 cm2. The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage. Conclusions: Sandwich transplantation with the collagen–elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons. PMID:22279382

Antibiotic free selection for the high level biosynthesis of a silk-elastin-like protein

PubMed Central

Barroca, Mário; Rodrigues, Paulo; Sobral, Rómulo; Costa, M. Manuela R.; Chaves, Susana R.; Machado, Raul; Casal, Margarida; Collins, Tony

2016-01-01

Silk-elastin-like proteins (SELPs) are a family of genetically engineered recombinant protein polymers exhibiting mechanical and biological properties suited for a wide range of applications in the biomedicine and materials fields. They are being explored as the next generation of biomaterials but low productivities and use of antibiotics during production undermine their economic viability and safety. We have developed an industrially relevant, scalable, fed-batch process for the high level production of a novel SELP in E. coli in which the commonly used antibiotic selection marker of the expression vector is exchanged for a post segregational suicide system, the separate-component-stabilisation system (SCS). SCS significantly augments SELP productivity but also enhances the product safety profile and reduces process costs by eliminating the use of antibiotics. Plasmid content increased following induction but no significant differences in plasmid levels were discerned when using SCS or the antibiotic selection markers under the controlled fed-batch conditions employed. It is suggested that the absence of competing plasmid-free cells improves host cell viability and enables increased productivity with SCS. With the process developed, 12.8 g L−1 purified SELP was obtained, this is the highest SELP productivity reported to date and clearly demonstrates the commercial viability of these promising polymers. PMID:27982135

Effects of Galla chinensis extracts on UVB-irradiated MMP-1 production in hairless mice.

PubMed

Sun, Zheng-wang; Hwang, Eunson; Lee, Hyun Ji; Lee, Tae Youp; Song, Hyun Geun; Park, Sang-Yong; Shin, Heon-Sub; Lee, Don-Gil; Yi, Tae Hoo

2015-01-01

Galla chinensis (GAC) is a natural traditional Chinese medicine that has been widely used in folk medicine. Although GAC compounds (mainly gallic acid and methyl gallate) possess strong antiviral, antibacterial, anticancer, and antioxidant activities, there is no report regarding topical or oral administration of GAC compounds on UVB irradiation-induced photoaging in hairless mice (SKH: HR-1). In the present study, we examined cell viability, intracellular reactive oxygen species (ROS), matrix metalloproteinase-1 (MMP-1), and interleukin-6 (IL-6) in skin fibroblasts and keratinocytes induced by UVB in vitro. We also studied skin damage by measuring skin thickness, elasticity, wrinkling and levels of protein MMP-1, elastin, procollagen type I, and transforming growth factor-β1 (TGF-β1) in hairless mouse skin chronically irradiated by UVB in vivo. GAC treatment significantly prevented skin photoaging by reducing the levels of ROS, MMP-1, and IL-6 and promoting production of elastin, procollagen type I, and TGF-β1. According to the results of H&E staining and Masson's trichrome staining, GAC reduced skin thickness and wrinkle formation while it increased skin elasticity. The effects of GAC on UVB-induced skin photoaging may be due to suppressed MMP-1 expression. These findings could be referenced for the development of new agents that target UVB-induced photoaging.

Photoreactive elastin-like proteins for use as versatile bioactive materials and surface coatings

PubMed Central

Raphel, Jordan; Parisi-Amon, Andreina; Heilshorn, Sarah

2012-01-01

Photocrosslinkable, protein-engineered biomaterials combine a rapid, controllable, cytocompatible crosslinking method with a modular design strategy to create a new family of bioactive materials. These materials have a wide range of biomedical applications, including the development of bioactive implant coatings, drug delivery vehicles, and tissue engineering scaffolds. We present the successful functionalization of a bioactive elastin-like protein with photoreactive diazirine moieties. Scalable synthesis is achieved using a standard recombinant protein expression host followed by site-specific modification of lysine residues with a heterobifunctional N-hydroxysuccinimide ester-diazirine crosslinker. The resulting biomaterial is demonstrated to be processable by spin coating, drop casting, soft lithographic patterning, and mold casting to fabricate a variety of two- and three-dimensional photocrosslinked biomaterials with length scales spanning the nanometer to millimeter range. Protein thin films proved to be highly stable over a three-week period. Cell-adhesive functional domains incorporated into the engineered protein materials were shown to remain active post-photo-processing. Human adipose-derived stem cells achieved faster rates of cell adhesion and larger spread areas on thin films of the engineered protein compared to control substrates. The ease and scalability of material production, processing versatility, and modular bioactive functionality make this recombinantly engineered protein an ideal candidate for the development of novel biomaterial coatings, films, and scaffolds. PMID:23015764

Photoreactive elastin-like proteins for use as versatile bioactive materials and surface coatings.

PubMed

Raphel, Jordan; Parisi-Amon, Andreina; Heilshorn, Sarah

2012-10-07

Photocrosslinkable, protein-engineered biomaterials combine a rapid, controllable, cytocompatible crosslinking method with a modular design strategy to create a new family of bioactive materials. These materials have a wide range of biomedical applications, including the development of bioactive implant coatings, drug delivery vehicles, and tissue engineering scaffolds. We present the successful functionalization of a bioactive elastin-like protein with photoreactive diazirine moieties. Scalable synthesis is achieved using a standard recombinant protein expression host followed by site-specific modification of lysine residues with a heterobifunctional N-hydroxysuccinimide ester-diazirine crosslinker. The resulting biomaterial is demonstrated to be processable by spin coating, drop casting, soft lithographic patterning, and mold casting to fabricate a variety of two- and three-dimensional photocrosslinked biomaterials with length scales spanning the nanometer to millimeter range. Protein thin films proved to be highly stable over a three-week period. Cell-adhesive functional domains incorporated into the engineered protein materials were shown to remain active post-photo-processing. Human adipose-derived stem cells achieved faster rates of cell adhesion and larger spread areas on thin films of the engineered protein compared to control substrates. The ease and scalability of material production, processing versatility, and modular bioactive functionality make this recombinantly engineered protein an ideal candidate for the development of novel biomaterial coatings, films, and scaffolds.

Exosomes derived from human umbilical cord blood mesenchymal stem cells stimulates rejuvenation of human skin.

PubMed

Kim, Yoon-Jin; Yoo, Sae Mi; Park, Hwan Hee; Lim, Hye Jin; Kim, Yu-Lee; Lee, Seunghee; Seo, Kwang-Won; Kang, Kyung-Sun

2017-11-18

Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) play an important role in cutaneous wound healing, and recent studies suggested that MSC-derived exosomes activate several signaling pathways, which are conducive in wound healing and cell growth. In this study, we investigated the roles of exosomes that are derived from USC-CM (USC-CM Exos) in cutaneous collagen synthesis and permeation. We found that USC-CM has various growth factors associated with skin rejuvenation. Our in vitro results showed that USC-CM Exos integrate in Human Dermal Fibroblasts (HDFs) and consequently promote cell migration and collagen synthesis of HDFs. Moreover, we evaluated skin permeation of USC-CM Exos by using human skin tissues. Results showed that Exo-Green labeled USC-CM Exos approached the outermost layer of the epidermis after 3 h and gradually approached the epidermis after 18 h. Moreover, increased expressions of Collagen I and Elastin were found after 3 days of treatment on human skin. The results showed that USC-CM Exos is absorbed into human skin, it promotes Collagen I and Elastin synthesis in the skin, which are essential to skin rejuvenation and shows the potential of USC-CM integration with the cosmetics or therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

Numerical model study of radio frequency vessel sealing thermodynamics

NASA Astrophysics Data System (ADS)

Pearce, John

2015-03-01

Several clinically successful clinical radio frequency vessel-sealing devices are currently available. The dominant thermodynamic principles at work involve tissue water vaporization processes. It is necessary to thermally denature vessel collagen, elastin and their adherent proteins to achieve a successful fusion. Collagens denature at middle temperatures, between about 60 and 90 C depending on heating time and rate. Elastin, and its adherent proteins, are more thermally robust, and require temperatures in excess of the boiling point of water at atmospheric pressure to thermally fuse. Rapid boiling at low apposition pressures leads to steam vacuole formation, brittle tissue remnants and frequently to substantial disruption in the vessel wall, particularly in high elastin-content arteries. High apposition pressures substantially increase the equilibrium boiling point of tissue water and are necessary to ensure a high probability of a successful seal. The FDM numerical models illustrate the beneficial effects of high apposition pressures.

Differential Regulation of Elastic Fiber Formation by Fibulin-4 and -5*

PubMed Central

Choudhury, Rawshan; McGovern, Amanda; Ridley, Caroline; Cain, Stuart A.; Baldwin, Andrew; Wang, Ming-Chuan; Guo, Chun; Mironov, Aleksandr; Drymoussi, Zoe; Trump, Dorothy; Shuttleworth, Adrian; Baldock, Clair; Kielty, Cay M.

2009-01-01

Fibulin-4 and -5 are extracellular glycoproteins with essential non-compensatory roles in elastic fiber assembly. We have determined how they interact with tropoelastin, lysyl oxidase, and fibrillin-1, thereby revealing how they differentially regulate assembly. Strong binding between fibulin-4 and lysyl oxidase enhanced the interaction of fibulin-4 with tropoelastin, forming ternary complexes that may direct elastin cross-linking. In contrast, fibulin-5 did not bind lysyl oxidase strongly but bound tropoelastin in terminal and central regions and could concurrently bind fibulin-4. Both fibulins differentially bound N-terminal fibrillin-1, which strongly inhibited their binding to lysyl oxidase and tropoelastin. Knockdown experiments revealed that fibulin-5 controlled elastin deposition on microfibrils, although fibulin-4 can also bind fibrillin-1. These experiments provide a molecular account of the distinct roles of fibulin-4 and -5 in elastic fiber assembly and how they act in concert to chaperone cross-linked elastin onto microfibrils. PMID:19570982

[A turning point in the knowledge of the structure-function-activity relations of elastin].

PubMed

Alix, A J

2001-01-01

In this review are presented the last new results of our research group dealing with the molecular structures (atomic level) of tropoelastin, elastin and elastin derived peptides studied by using essentially methods of bioinformatics (theoretical predictions and molecular modelling) linked to experimental circular dichroism spectroscopic studies. We already had characterized both the local secondary structure and some parts of the tertiary structure of the tropoelastin and elastin molecules (human, bovine...), by using either theoretical predictions (local secondary structure, linear epitopes...) and/or experimental data (optical spectroscopic methods: Raman scattering, infrared absorption, circular dichroism). Except the cross-linking regions which are in helical conformations, the whole tropoelastin structure displays a lot of beta-reverse turns which usually belong to irregular structures in proteins. These turns play a key role in other regularly structures orientation (alpha-helix, beta-strand), thus they are very important in the native protein 3D architecture. It is particularly true for human tropoelastin, because its sequence is rich in glycines and prolines, and these residues are frequently met in beta-turns (a beta-turn is made of four consecutive residues which are stabilized by an hydrogen bond). Several types of beta-turns can be defined with the dihedral angles values phi and psi of the two central residues. Thus, by using a very recent updated set of propensities for the amino acid residues to belong to given types of reverse beta-turns (extracted from a reference set of known 3-D structures of globular proteins), we have determined, (by using our home made software COUDES), for all possible tetrapeptides of the human tropoelastin sequence, the distribution and the characterization of the possible type of turns. Thus, it is shown that the locations and/or the types of these reverse beta-turns reveal a regularity and are not all random. This confirms our hypothesis that intra-molecular elasticity of tropoelastin could be explained by the possibility of transitions between conformations involving short beta-strands and beta-turns. This result is of great interest in the construction (by using molecular biology) of elastic biomaterials derived from the elastin sequence (particularly, the elastin derived peptides corresponding to the sequence exon 21--(exon 24--exon 24...). Our study permit also to predict the conformations of specific elastin derived peptides which could have interesting biological activity. Peptides resulting from the degradation of elastin, the insoluble polymer of tropoelastin and responsible for the elasticity of vertebrate tissues, can induce biological effects and notably the regulation of matrix metalloproteinases (MMP-s) activity. Recently, it was proposed that some elastin derived hexapeptides resulting from circular permutations of VGVAPG (a three fold repetition sequence in exon 24 of human tropoelastin) possess MMP-1 production and activation regulation properties. This effect depends on the presence of the tropoelastin specific membraneous receptor 67 KDa EBP (Elastin Binding Protein). Our results obtained by using both circular dichroism spectroscopy and linear predictions confirmed the hypothesis of a structure dependent mechanism with a possibly occurring type VIII beta-turn on the first four residues of the GXXPG sequence consensus which is only present among all active peptides. Thus, we have performed extensive molecular dynamics studies, in both implicit and explicit solvent, on these active and inactive elastin derived hexapeptides. Using our own analysis method of pattern recognition of the types of the beta-reverse-turns followed during the molecular dynamics trajectory, we found that active and inactive peptides effectively form two well distinct conformational groups in which active peptides preferentially adopt conformation close to type VIII GXXP (beta-reverse-turn. The structural role of the C terminal G residue could also be explained. Additional molecular simulations on (VGVAPG)2 and (VGVAPG)3 show the formation of two or three GXXP tetrapeptides adopting a structure close to type VIII beta-reverse-turn, suggesting a local conformational preference for this motif. This observation of a specific structural single and/or repeated motif is in agreement with the circular dichroism spectra of the involved (VGVAPG)1, (VGVAPG)2 and (VGVAPG)3 peptides and then it can be proposed that their biological activities have to be linear. The final aim of this type of work is to understand more about the sequence/structure/function/activity relationships of those structured peptides in order to propose specific sequences (corresponding to specific structures) for best biological activity results.

LGL1 modulates proliferation, apoptosis, and migration of human fetal lung fibroblasts.

PubMed

Zhang, Hui; Sweezey, Neil B; Kaplan, Feige

2015-02-15

Rapid growth and formation of new gas exchange units (alveogenesis) are hallmarks of the perinatal lung. Bronchopulmonary dysplasia (BPD), common in very premature infants, is characterized by premature arrest of alveogenesis. Mesenchymal cells (fibroblasts) regulate both lung branching and alveogenesis through mesenchymal-epithelial interactions. Temporal or spatial deficiency of late-gestation lung 1/cysteine-rich secretory protein LD2 (LGL1/CRISPLD2), expressed in and secreted by lung fibroblasts, can impair both lung branching and alveogenesis (LGL1 denotes late gestation lung 1 protein; LGL1 denotes the human gene; Lgl1 denotes the mouse/rat gene). Absence of Lgl1 is embryonic lethal. Lgl1 levels are dramatically reduced in oxygen toxicity rat models of BPD, and heterozygous Lgl1(+/-) mice exhibit features resembling human BPD. To explore the role of LGL1 in mesenchymal-epithelial interactions in developing lung, we developed a doxycycline (DOX)-inducible RNA-mediated LGL1 knockdown cellular model in human fetal lung fibroblasts (MRC5(LGL1KD)). We assessed the impact of LGL1 on cell proliferation, cell migration, apoptosis, and wound healing. DOX-induced MRC5(LGL1KD) suppressed cell growth and increased apoptosis of annexin V(+) staining cells and caspase 3/7 activity. LGL1-conditioned medium increased migration of fetal rat primary lung epithelial cells and human airway epithelial cells. Impaired healing by MRC5(LGL1KD) cells of a wound model was attenuated by addition of LGL1-conditioned medium. Suppression of LGL1 was associated with dysregulation of extracellular matrix genes (downregulated MMP1, ColXVα1, and ELASTIN) and proapoptosis genes (upregulated BAD, BAK, CASP2, and TNFRSF1B) and inhibition of 44/42MAPK phosphorylation. Our findings define a role for LGL1 in fibroblast expansion and migration, epithelial cell migration, and mesenchymal-epithelial signaling, key processes in fetal lung development. Copyright © 2015 the American Physiological Society.

The effect of a collagen-elastin matrix on adhesion formation after flexor tendon repair in a rabbit model.

PubMed

Wichelhaus, Dagmar Alice; Beyersdoerfer, Sascha Tobias; Gierer, Philip; Vollmar, Brigitte; Mittlmeier, Th

2016-07-01

The outcome of flexor tendon surgery is negatively affected by the formation of adhesions which can occur during the healing of the tendon repair. In this experimental study, we sought to prevent adhesion formation by wrapping a collagen-elastin scaffold around the repaired tendon segment. In 28 rabbit hind legs, the flexor tendons of the third and fourth digits were cut and then repaired using a two-strand suture technique on the fourth digit and a four-strand technique on the third digit. Rabbits were randomly assigned to study and control groups. In the control group, the operation ended by closing the tendon sheath and the skin. In the study group, a collagen-elastin scaffold was wrapped around the repaired tendon segment in both digits. After 3 and 8 weeks, the tendons were harvested and processed histologically. The range of motion of the digits and the gap formation between the repaired tendon ends were measured. The formation of adhesions, infiltration of leucocytes and extracellular inflammatory response were quantified. At the time of tendon harvesting, all joints of the operated toes showed free range of motion. Four-strand core sutures lead to significantly less diastasis between the repaired tendon ends than two-strand core suture repairs. The collagen-elastin scaffold leads to greater gapping after 3 weeks compared to the controls treated without the matrix. Within the tendons treated with the collagen-elastin matrix, a significant boost of cellular and extracellular inflammation could be stated after 3 weeks which was reflected by a higher level of CAE positive cells and more formation of myofibroblasts in the αSMA stain in the study group. The inflammatory response subsided gradually and significantly until the late stage of the study. Both the cellular and extracellular inflammatory response was emphasized with the amount of material used for the repair. The use of a collagen-elastin matrix cannot be advised for the prevention of adhesion formation in flexor tendon surgery, because it enhances both cellular and extracellular inflammation. Four-strand core sutures lead to less gapping than two-strand core sutures, but at the same time, the cellular and extracellular inflammatory response is more pronounced.

The role of peroxisome proliferator-activated receptor-coactivator-1 gene in skin aging

PubMed Central

Aghaei, Shahrzad; Nilforoushzadeh, Mohammad Ali; Aghaei, Maryam

2016-01-01

Skin aging is a continuous process that exhibits fine and deep wrinkles, thin and transparent skin, loss of underlying fat, dry skin and itch, following decreased collagen and elastin synthesis. Both extrinsic and intrinsic agents are considered in the pathogenesis on skin aging. Extrinsic factors such as sun exposure, windy and dry weather, nutrition, and lifestyle may induce premature aging, toxic-free radicals, and reactive oxygen species due to decreasing normal function of mitochondria which play the major intrinsic factors in premature skin aging. One of the major genetic factors in mitochondrial function is peroxisome proliferator-activated receptor-coactivator-1 (PGC-1) gene. This factor could delay skin aging by increasing the mitochondrial biogenesis and replication and oxidative phosphorylation and so may induce free radical scavenging. This review is focused on intrinsic skin aging and the role of PGC-1 protein in decreasing effect of aging causes. PMID:27904582

Growth Factor Stimulation Improves the Structure and Properties of Scaffold-Free Engineered Auricular Cartilage Constructs

PubMed Central

Rosa, Renata G.; Joazeiro, Paulo P.; Bianco, Juares; Kunz, Manuela; Weber, Joanna F.; Waldman, Stephen D.

2014-01-01

The reconstruction of the external ear to correct congenital deformities or repair following trauma remains a significant challenge in reconstructive surgery. Previously, we have developed a novel approach to create scaffold-free, tissue engineering elastic cartilage constructs directly from a small population of donor cells. Although the developed constructs appeared to adopt the structural appearance of native auricular cartilage, the constructs displayed limited expression and poor localization of elastin. In the present study, the effect of growth factor supplementation (insulin, IGF-1, or TGF-β1) was investigated to stimulate elastogenesis as well as to improve overall tissue formation. Using rabbit auricular chondrocytes, bioreactor-cultivated constructs supplemented with either insulin or IGF-1 displayed increased deposition of cartilaginous ECM, improved mechanical properties, and thicknesses comparable to native auricular cartilage after 4 weeks of growth. Similarly, growth factor supplementation resulted in increased expression and improved localization of elastin, primarily restricted within the cartilaginous region of the tissue construct. Additional studies were conducted to determine whether scaffold-free engineered auricular cartilage constructs could be developed in the 3D shape of the external ear. Isolated auricular chondrocytes were grown in rapid-prototyped tissue culture molds with additional insulin or IGF-1 supplementation during bioreactor cultivation. Using this approach, the developed tissue constructs were flexible and had a 3D shape in very good agreement to the culture mold (average error <400 µm). While scaffold-free, engineered auricular cartilage constructs can be created with both the appropriate tissue structure and 3D shape of the external ear, future studies will be aimed assessing potential changes in construct shape and properties after subcutaneous implantation. PMID:25126941

Biaxial deformation of collagen and elastin fibers in coronary adventitia

PubMed Central

Chen, Huan; Slipchenko, Mikhail N.; Liu, Yi; Zhao, Xuefeng; Cheng, Ji-Xin; Lanir, Yoram

2013-01-01

The microstructural deformation-mechanical loading relation of the blood vessel wall is essential for understanding the overall mechanical behavior of vascular tissue in health and disease. We employed simultaneous mechanical loading-imaging to quantify in situ deformation of individual collagen and elastin fibers on unstained fresh porcine coronary adventitia under a combination of vessel inflation and axial extension loading. Specifically, the specimens were imaged under biaxial loads to study microscopic deformation-loading behavior of fibers in conjunction with morphometric measurements at the zero-stress state. Collagen fibers largely orientate in the longitudinal direction, while elastin fibers have major orientation parallel to collagen, but with additional orientation angles in each sublayer of the adventitia. With an increase of biaxial load, collagen fibers were uniformly stretched to the loading direction, while elastin fibers gradually formed a network in sublayers, which strongly depended on the initial arrangement. The waviness of collagen decreased more rapidly at a circumferential stretch ratio of λθ = 1.0 than at λθ = 1.5, while most collagen became straightened at λθ = 1.8. These microscopic deformations imply that the longitudinally stiffer adventitia is a direct result of initial fiber alignment, and the overall mechanical behavior of the tissue is highly dependent on the corresponding microscopic deformation of fibers. The microstructural deformation-loading relation will serve as a foundation for micromechanical models of the vessel wall. PMID:24092692

Histopathological Differences Between the Anterior and Posterior Brain Arteries as a Function of Aging.

PubMed

Roth, William; Morgello, Susan; Goldman, James; Mohr, Jay P; Elkind, Mitchell S V; Marshall, Randolph S; Gutierrez, Jose

2017-03-01

We tested the hypothesis that posterior brain arteries differ pathologically from anterior brain arteries and that this difference varies with age. Brain large arteries from 194 autopsied individuals (mean age 56±17 years, 63% men, 25% nonwhite, 17% with brain infarcts) were analyzed to obtain the areas of arterial layers and lumen as well as the relative content of elastin, collagen, and amyloid. Visual rating was used to determine the prevalence of atheroma, calcification, vasa vasorum , pattern of intima thickening, and internal elastic lamina gaps. We used multilevel models adjusting for age, sex, ethnicity, vascular risk factors, artery type and location, and multiple comparisons. Of 1362 large artery segments, 5% had vasa vasorum, 5% had calcifications, 15% had concentric intimal thickening, and 11% had atheromas. Posterior brain arteries had thinner walls, less elastin, and more concentric intima thickening than anterior brain arteries. Compared to anterior brain arteries, the basilar artery had higher arterial area encircled by the internal elastic lamina, whereas the vertebral arteries had higher prevalence of elastin loss, concentric intima thickening, and nonatherosclerotic stenosis. In younger individuals, vertebral artery calcifications were more likely than calcification in anterior brain arteries, but this difference attenuated with age. Posterior brain arteries differ pathologically from anterior brain arteries in the degree of wall thickening, elastin loss, and concentric intimal thickening. © 2017 American Heart Association, Inc.

Elastin Cables Define the Axial Connective Tissue System in the Murine Lung.

PubMed

Wagner, Willi; Bennett, Robert D; Ackermann, Maximilian; Ysasi, Alexandra B; Belle, Janeil; Valenzuela, Cristian D; Pabst, Andreas; Tsuda, Akira; Konerding, Moritz A; Mentzer, Steven J

2015-11-01

The axial connective tissue system is a fiber continuum of the lung that maintains alveolar surface area during changes in lung volume. Although the molecular anatomy of the axial system remains undefined, the fiber continuum of the lung is central to contemporary models of lung micromechanics and alveolar regeneration. To provide a detailed molecular structure of the axial connective tissue system, we examined the extracellular matrix of murine lungs. The lungs were decellularized using a 24 hr detergent treatment protocol. Systematic evaluation of the decellularized lungs demonstrated no residual cellular debris; morphometry demonstrated a mean 39 ± 7% reduction in lung dimensions. Scanning electron microscopy (SEM) demonstrated an intact structural hierarchy within the decellularized lung. Light, fluorescence, and SEM of precision-cut lung slices demonstrated that alveolar duct structure was defined by a cable line element encased in basement membrane. The cable line element arose in the distal airways, passed through septal tips and inserted into neighboring blood vessels and visceral pleura. The ropelike appearance, collagenase resistance and anti-elastin immunostaining indicated that the cable was an elastin macromolecule. Our results indicate that the helical line element of the axial connective tissue system is composed of an elastin cable that not only defines the structure of the alveolar duct, but also integrates the axial connective tissue system into visceral pleura and peripheral blood vessels. © 2015 Wiley Periodicals, Inc.

Advances in biomimetic regeneration of elastic matrix structures

PubMed Central

Sivaraman, Balakrishnan; Bashur, Chris A.

2012-01-01

Elastin is a vital component of the extracellular matrix, providing soft connective tissues with the property of elastic recoil following deformation and regulating the cellular response via biomechanical transduction to maintain tissue homeostasis. The limited ability of most adult cells to synthesize elastin precursors and assemble them into mature crosslinked structures has hindered the development of functional tissue-engineered constructs that exhibit the structure and biomechanics of normal native elastic tissues in the body. In diseased tissues, the chronic overexpression of proteolytic enzymes can cause significant matrix degradation, to further limit the accumulation and quality (e.g., fiber formation) of newly deposited elastic matrix. This review provides an overview of the role and importance of elastin and elastic matrix in soft tissues, the challenges to elastic matrix generation in vitro and to regenerative elastic matrix repair in vivo, current biomolecular strategies to enhance elastin deposition and matrix assembly, and the need to concurrently inhibit proteolytic matrix disruption for improving the quantity and quality of elastogenesis. The review further presents biomaterial-based options using scaffolds and nanocarriers for spatio-temporal control over the presentation and release of these biomolecules, to enable biomimetic assembly of clinically relevant native elastic matrix-like superstructures. Finally, this review provides an overview of recent advances and prospects for the application of these strategies to regenerating tissue-type specific elastic matrix structures and superstructures. PMID:23355960

13C, 2H NMR Studies of Structural and Dynamical Modifications of Glucose-Exposed Porcine Aortic Elastin

PubMed Central

Silverstein, Moshe C.; Bilici, Kübra; Morgan, Steven W.; Wang, Yunjie; Zhang, Yanhang; Boutis, Gregory S.

2015-01-01

Elastin, the principal component of the elastic fiber of the extracellular matrix, imparts to vertebrate tissues remarkable resilience and longevity. This work focuses on elucidating dynamical and structural modifications of porcine aortic elastin exposed to glucose by solid-state NMR spectroscopic and relaxation methodologies. Results from macroscopic stress-strain tests are also presented and indicate that glucose-treated elastin is mechanically stiffer than the same tissue without glucose treatment. These measurements show a large hysteresis in the stress-strain behavior of glucose-treated elastin—a well-known signature of viscoelasticity. Two-dimensional relaxation NMR methods were used to investigate the correlation time, distribution, and population of water in these samples. Differences are observed between the relative populations of water, whereas the measured correlation times of tumbling motion of water across the samples were similar. 13C magic-angle-spinning NMR methods were applied to investigate structural and dynamical modifications after glucose treatment. Although some overall structure is preserved, the process of glucose exposure results in more heterogeneous structures and slower mobility. The correlation times of tumbling motion of the 13C-1H internuclear vectors in the glucose-treated sample are larger than in untreated samples, pointing to their more rigid structure. The 13C cross-polarization spectra reveal a notably increased α-helical character in the alanine motifs after glucose exposure. Results from molecular dynamics simulations are provided that add further insight into dynamical and structural changes of a short repeat, [VPGVG]5, an alanine pentamer, desmosine, and isodesmosine sites with and without glucose. The simulations point to changes in the entropic and energetic contributions in the retractive forces of VPGVG and AAAAA motifs. The most notable change is the increase of the energetic contribution in the retractive force due to peptide-glucose interactions of the VPGVG motif, which may play an important role in the observed stiffening in glucose-treated elastin. PMID:25863067

Antibodies to elastin peptides in sera of Belgian Draught horses with chronic progressive lymphoedema.

PubMed

van Brantegem, L; de Cock, H E V; Affolter, V K; Duchateau, L; Hoogewijs, M K; Govaere, J; Ferraro, G L; Ducatelle, R

2007-09-01

Chronic progressive lymphoedema (CPL) is a recently recognised disease of the lymphatic system characterised by lesions in the skin of the lower legs in several draught horse breeds, including the Belgian Draught hourse. Clinical signs slowly progress and result in severe disfigurement of the limbs. Ideally, supportive treatment should be started early in the disease process. However early diagnosis and monitoring progression of CPL is still a challenge. Elastin changes, characterised by morphological alterations as well as increased desmosine levels, in the skin of the distal limbs of horses affected with CPL are probably associated with a marked release of elastin degradation products, which elicit production of circulating anti-elastin antibodies (AEAbs) in the serum. An enzyme-linked immunosorbent assay (ELISA) for detection of serum AEAbs may document elastin breakdown. An ELISA technique was used to evaluate levels of AEAbs in sera of 97 affected Belgian Draught horses that were clinically healthy except for possible skin lesions, associated with CPL in their distal limbs. The horses were divided into 5 groups according to the severity of these skin lesions: normal horses (Group 1, n = 36), horses with mild lesions (Group 2, n = 43), horses with moderate lesions (Group 3, n = 8), horses with severe lesions (Group 4, n = 10) and, as a control, healthy Warmblood horses, unaffected by the disease (Group 5, n = 83). Horses with clinical signs of CPL had significantly higher AEAb levels compared to clinically normal Belgian Draught horses and to healthy Warmblood horses. These levels correlated with severity of lesions. CPL in draught horses is associated with an increase of serum AEAbs. Evaluation of serum levels of AEAbs by ELISA might be a useful diagnostic aid for CPL. Pathological degradation of elastic fibres, resulting in deficient support of the distal lymphatics, is proposed as a contributing factor for CPL in Belgian Draught horses.

Elastomeric Polypeptides

PubMed Central

van Eldijk, Mark B.; McGann, Christopher L.

2013-01-01

Elastomeric polypeptides are very interesting biopolymers and are characterized by rubber-like elasticity, large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Their useful properties have motivated their use in a wide variety of materials and biological applications. This chapter focuses on elastin and resilin – two elastomeric biopolymers – and the recombinant polypeptides derived from them (elastin-like polypeptides and resilin-like polypeptides). This chapter also discusses the applications of these recombinant polypeptides in the fields of purification, drug delivery, and tissue engineering. PMID:21826606

Elastin-like-polypeptide based fusion proteins for osteogenic factor delivery in bone healing.

PubMed

McCarthy, Bryce; Yuan, Yuan; Koria, Piyush

2016-07-08

Modern treatments of bone injuries and diseases are becoming increasingly dependent on the usage of growth factors to stimulate bone growth. Bone morphogenetic protein-2 (BMP-2), a potent osteogenic inductive protein, exhibits promising results in treatment models, but recently has had its practical efficacy questioned due to the lack of local retention, ectopic bone formation, and potentially lethal inflammation. Where a new delivery technique of the BMP-2 is necessary, here we demonstrate the viability of an elastin-like peptide (ELP) fusion protein containing BMP-2 for delivery of the BMP-2. This fusion protein retains the performance characteristics of both the BMP-2 and ELP. The fusion protein was found to induce osteogenic differentiation of mesenchymal stem cells as evidenced by the production of alkaline phosphatase and extracellular calcium deposits in response to treatment by the fusion protein. Retention of the ELPs inverse phase transition property has allowed for expression of the fusion protein within a bacterial host (such as Escherichia coli) and easy and rapid purification using inverse transition cycling. The fusion protein formed self-aggregating nanoparticles at human-body temperature. The data collected suggests the viability of these fusion protein nanoparticles as a dosage-efficient and location-precise noncytotoxic delivery vehicle for BMP-2 in bone treatment. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1029-1037, 2016. © 2016 American Institute of Chemical Engineers.

[Purification and physicochemical properties of Bacillus thuringiensis IMB B-7324 peptidase with elastolytic and fibrinolytic activity].

PubMed

Matseliukh, O V; Nidialkova, N A; Varbanets', L D

2012-01-01

The scheme of isolation and purification of Bacillus thuringiensis IMV B-7324 peptidase has been developed. This scheme includes ammonium sulfate precipitation and chromatography on neutral and charged TSK-gels. It was found that the enzyme hydrolyzes elastin and fibrin. The molecular weight is 26 kDa. It was shown that the enzyme is an alkaline serine peptidase. The optimal pH of hydrolysis of elastin and fibrin were 9.0 and 10.0, respectively. The optimal temperature of elastin and fibrin hydrolysis are 40 and 50 degrees C, respectively. The high stability of the purified preparation in the studied range of pH and temperature was shown. The stabilizing effect of zinc at a concentration of 1 mM on the elastase activity, and the inhibitory effect of other divalent cations under study have been established. The investigated chloride and acetate anions reduced activity by 20%, while phosphate anions increased activity by 15-30%.

Multiphoton microscopy of ECM proteins in baboon aortic leaflet

NASA Astrophysics Data System (ADS)

Gonzalez, Mariacarla; Saytashev, Ilyas; Luna, Camila; Gonzalez, Brittany; Pinero, Alejandro; Perez, Manuel; Ramaswamy, Sharan; Ramella-Roman, Jessica

2018-02-01

The extracellular matrix (ECM) plays crucial role in defining mechanical properties of a heart valve yet the mechanobiological role of the ECM proteins - collagen and elastin - in living heart valve leaflets is still poorly understood. In this study, non-linear microscopy was used to obtain three dimensional images of collagen and elastin arrangement in aortic leaflets under combined steady flow (850 ml/min) and cyclic flexure (1 Hz) mechanical (dynamic) training. A novel bioreactor capable of mimicking the flow conditions in a living heart was used in this study and was optimized for microscopic imagery. A custom made non-linear microscope was used in this study to provide Second Harmonic Generation (SHG) imaging of collagen arrangement and two-photon imaging of elastin. Two control and three trained leaflet samples from static and dynamic tissue culture were imaged to observe protein changes in the tissue for a period of seven days. Dynamic training led to a decrease in alignment index of the protein fibers compared to the static treatment.

Dual stimuli-sensitive dendrimers: Photothermogenic gold nanoparticle-loaded thermo-responsive elastin-mimetic dendrimers.

PubMed

Fukushima, Daichi; Sk, Ugir Hossain; Sakamoto, Yasuhiro; Nakase, Ikuhiko; Kojima, Chie

2015-08-01

Dendrimers are synthetic macromolecules with unique structures that can work as nanoplatforms for both photothermogenic gold nanoparticles (AuNPs) and thermosensitive elastin-like peptides (ELPs) with valine-proline-glycine-valine-glycine (VPGVG) repeats. In this study, photothermogenic AuNPs were loaded into thermo-responsive elastin-mimetic dendrimers (dendrimers conjugating ELPs at their periphery) to produce dual stimuli-sensitive nanoparticles. Polyamidoamine G4 dendrimers were modified with acetylated VPGVG and (VPGVG)2, and the resulting materials were named ELP1-den and ELP2-den, respectively. The AuNPs were prepared by the reduction of Au ions using a dendrimer-nanotemplated method. The AuNP-loaded elastin-mimetic dendrimers exhibited photothermal properties. ELP1-den and ELP2-den showed similar temperature-dependent changes in their conformations. Phase transitions were observed at around 55°C and 35°C for the AuNP-loaded ELP1-den and AuNP-loaded ELP2-den, respectively, but not for the corresponding PEGylated dendrimer. In contrast to the AuNP-loaded PEGylated dendrimer, AuNP-loaded ELP2-den readily associated with cells and induced efficient photocytotoxicity at 37°C. The cell association and the photocytotoxicity properties of AuNP-loaded ELP2-den could be controlled by temperature. These results therefore suggest that dual stimuli-sensitive dendrimer nanoparticles of this type could be used for photothermal therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Continuous exposure to low amplitude extremely low frequency electrical fields characterizing the vascular streaming potential alters elastin accumulation in vascular smooth muscle cells.

PubMed

Bergethon, Peter R; Kindler, Dean D; Hallock, Kevin; Blease, Susan; Toselli, Paul

2013-07-01

In normal development and pathology, the vascular system depends on complex interactions between cellular elements, biochemical molecules, and physical forces. The electrokinetic vascular streaming potential (EVSP) is an endogenous extremely low frequency (ELF) electrical field resulting from blood flowing past the vessel wall. While generally unrecognized, it is a ubiquitous electrical biophysical force to which the vascular tree is exposed. Extracellular matrix elastin plays a central role in normal blood vessel function and in the development of atherosclerosis. It was hypothesized that ELF fields of low amplitude would alter elastin accumulation, supporting a link between the EVSP and the biology of vascular smooth muscle cells. Neonatal rat aortic smooth muscle cell cultures were exposed chronically to electrical fields characteristic of the EVSP. Extracellular protein accumulation, DNA content, and electron microscopic (EM) evaluation were performed after 2 weeks of exposure. Stimulated cultures showed no significant change in cellular proliferation as measured by the DNA concentration. The per-DNA normalized protein in the extracellular matrix was unchanged while extracellular elastin accumulation decreased 38% on average. EM analysis showed that the stimulated cells had a 2.85-fold increase in mitochondrial number. These results support the formulation that ELF fields are a potential factor in both normal vessel biology and in the pathogenesis of atherosclerotic diseases including heart disease, stroke, and peripheral vascular disease. Copyright © 2013 Wiley Periodicals, Inc.

Extracellular Matrix Disarray as A Mechanism for Greater Abdominal vs. Thoracic Aortic Stiffness with Aging in Primates

PubMed Central

Zhang, Jie; Zhao, Xin; Vatner, Dorothy E; McNulty, Tara; Bishop, Sanford; Sun, Zhe; Shen, You-Tang; Chen, Li; Meininger, Gerald A; Vatner, Stephen F

2016-01-01

Objective Increased vascular stiffness is central to the pathophysiology of aging, hypertension, diabetes and atherosclerosis. However, relatively few studies have examined vascular stiffness in both the thoracic and abdominal aorta with aging, despite major differences in anatomy, embryological origin and relation to aortic aneurysm. Approach and Results The two other unique features of this study were 1) to study young (9±1 years) and old (26±1 years) male monkeys, and 2) to study direct and continuous measurements of aortic pressure and thoracic and abdominal aortic diameters in conscious monkeys. As expected, aortic stiffness, β, was increased p<0.05, 2–3 fold, in old vs. young thoracic aorta, and augmented further with superimposition of acute hypertension with phenylephrine. Surprisingly, stiffness was not greater in old thoracic aorta than young abdominal aorta. These results can be explained in part by the collagen/elastin ratio, but more importantly, by disarray of collagen and elastin, which correlated best with vascular stiffness. However, vascular smooth muscle cell stiffness, was not different in thoracic vs. abdominal aorta in either young or old monkeys. Conclusions Thus, aortic stiffness increases with aging as expected, but the most severe increases in aortic stiffness observed in the abdominal aorta is novel, where values in young monkeys equaled, or even exceeded, values of thoracic aortic stiffness in old monkeys. These results can be explained by alterations in collagen/elastin ratio, but even more importantly by collagen and elastin disarray. PMID:26891739

Murray's Law in elastin haploinsufficient (Eln+/-) and wild-type (WT) mice.

PubMed

Sather, Bradley A; Hageman, Daniel; Wagenseil, Jessica E

2012-12-01

Using either the principle of minimum energy or constant shear stress, a relation can be derived that predicts the diameters of branching vessels at a bifurcation. This relation, known as Murray's Law, has been shown to predict vessel diameters in a variety of cardiovascular systems from adult humans to developing chicks. The goal of this study is to investigate Murray's Law in vessels from mice that are haploinsufficient for the elastin protein (Eln+/-). Elastin is one of the major proteins in the blood vessel wall and is organized in concentric rings, known as lamellae, with smooth muscle cells (SMCs) around the vessel lumen. Eln+/- mice have an increased number of lamellae, as well as smaller, thinner vessels. It is possible that due to decreased amounts of elastin available for vessel wall remodeling during development and in adulthood, Eln+/- vessels would not follow Murray's Law. We examined vessel bifurcations in six different physiologic regions, including the brain, heart, epidermis, ceocum (or cecum), testes, and intestines, in Eln+/- mice and wild-type (WT) littermates. All vessels were between 40 and 300 μm in diameter. We found that the diameters of both Eln+/- and WT vessels have an average of 13% error from the diameters predicted by Murray's Law, with no significant differences between genotypes or physiologic regions. The data suggest that vessels are optimized to follow Murray's Law, despite limitations on the proteins available for growth and remodeling of the vessel wall.

Quantitative comparison of structure and dynamics of elastin following three isolation schemes by 13C solid state NMR and MALDI mass spectrometry.

PubMed

Papaioannou, A; Louis, M; Dhital, B; Ho, H P; Chang, E J; Boutis, G S

2015-05-01

Methods for isolating elastin from fat, collagen, and muscle, commonly used in the design of artificial elastin based biomaterials, rely on exposing tissue to harsh pH levels and temperatures that usually denature many proteins. At present, a quantitative measurement of the modifications to elastin following isolation from other extracellular matrix constituents has not been reported. Using magic angle spinning (13)C NMR spectroscopy and relaxation methodologies, we have measured the modification in structure and dynamics following three known purification protocols. Our experimental data reveal that the (13)C spectra of the hydrated samples appear remarkably similar across the various purification methods. Subtle differences in the half maximum widths were observed in the backbone carbonyl suggesting possible structural heterogeneity across the different methods of purification. Additionally, small differences in the relative signal intensities were observed between purified samples. Lyophilizing the samples results in a reduction of backbone motion and reveals additional differences across the purification methods studied. These differences were most notable in the alanine motifs indicating possible changes in cross-linking or structural rigidity. The measured correlation times of glycine and proline moieties are observed to also vary considerably across the different purification methods, which may be related to peptide bond cleavage. Lastly, the relative concentration of desmosine cross-links in the samples quantified by MALDI mass spectrometry is reported. Copyright © 2015 Elsevier B.V. All rights reserved.

The gene for replication factor C subunit 2 (RFC2) is within the 7q11.23 Williams syndrome deletion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peoples, R.; Perez-Jurado, L.; Francke, U.

1996-06-01

Williams syndrome (WS) is a developmental disorder with multiple system manifestations, including supraval var aortic stenosis (SVAS), peripheral pulmonic stenosis, connective tissue abnormalities, short stature, characteristic personality profile and cognitive deficits, and variable hypercalcemia in infancy. It is caused by heterozygosity for a chromosomal deletion of part of band 7q11.23 including the elastin locus (ELN). Since disruption of the ELN gene causes autosomal dominant SVAS, it is assumed that ELN haploinsufficiency is responsible for the cardiovascular features of WS. The deletion that extends from the ELN locus in both directions is {ge}200 kb in size, although estimates of {ge}2 Mbmore » are suggested by high-resolution chromosome banding and physical mapping studies. We have searched for additional dosage-sensitive genes within the deletion that may be responsible for the noncardiovascular features. We report here that the gene for replication factor C subunit 2 (RFC2) maps within the WS deletion region and was found to be deleted in all of 18 WS patients studied. The protein product of RFC2 is part of a multimeric complex involved in DNA elongation during replication. 14 refs., 3 figs.« less

Biofilm density and detection of biofilm-producing genes in methicillin-resistant Staphylococcus aureus strains.

PubMed

Szczuka, Ewa; Urbańska, Katarzyna; Pietryka, Marta; Kaznowski, Adam

2013-01-01

Many serious diseases caused by Staphylococcus aureus appear to be associated with biofilms. Therefore, we investigated the biofilm-forming ability of the methicillin-resistant S. aureus (MRSA) isolates collected from hospitalized patients. As many as 96 % strains had the ability to form biofilm in vitro. The majority of S. aureus strains formed biofilm in ica-dependent mechanism. However, 23 % of MRSA isolates formed biofilm in ica-independent mechanism. Half of these strains carried fnbB genes encoding surface proteins fibronectin-binding protein B involved in intercellular accumulation and biofilm development in S. aureus strains. The biofilm structures were examined via confocal laser scanning microscopy (CLSM) and three-dimensional structures were reconstructed. The images obtained in CLSM revealed that the biofilm created by ica-positive strains was different from biofilm formed by ica-negative strains. The MRSA population showed a large genetic diversity and we did not find a single clone that occurred preferentially in hospital environment. Our results demonstrated the variation in genes encoding adhesins for the host matrix proteins (elastin, laminin, collagen, fibronectin, and fibrinogen) and in the gene involved in biofilm formation (icaA) within the majority of S. aureus clones.

Development of a Recombinant Multifunctional Biomacromolecule for Targeted Gene Transfer to Prostate Cancer Cells.

PubMed

Hatefi, Arash; Karjoo, Zahra; Nomani, Alireza

2017-09-11

The objective of this study was to genetically engineer a fully functional single chain fusion peptide composed of motifs from diverse biological and synthetic origins that can perform multiple tasks including DNA condensation, cell targeting, cell transfection, particle shielding from immune system and effective gene transfer to prostate tumors. To achieve the objective, a single chain biomacromolecule (vector) consisted of four repeatative units of histone H2A peptide, fusogenic peptide GALA, short elastin-like peptide, and PC-3 cell targeting peptide was designed. To examine the functionality of each motif in the vector sequence, it was characterized in terms of size and zeta potential by Zetasizer, PC-3 cell targeting and transfection by flowcytometry, IgG induction by immunogenicity assay, and PC-3 tumor transfection by quantitative live animal imaging. Overall, the results of this study showed the possibility of using genetic engineering techniques to program various functionalities into one single chain vector and create a multifunctional nonimmunogenic biomacromolecule for targeted gene transfer to prostate cancer cells. This proof-of-concept study is a significant step forward toward creating a library of vectors for targeted gene transfer to any cancer cell type at both in vitro and in vivo levels.

Stepwise Mechanism of Temperature-Dependent Coacervation of the Elastin-like Peptide Analogue Dimer, (C(WPGVG)3)2.

PubMed

Tatsubo, Daiki; Suyama, Keitaro; Miyazaki, Masaya; Maeda, Iori; Nose, Takeru

2018-03-13

Elastin-like peptides (ELPs) are distinct, repetitive, hydrophobic sequences, such as (VPGVG) n , that exhibit coacervation, the property of reversible, temperature-dependent self-association and dissociation. ELPs can be found in elastin and have been developed as new scaffold biomaterials. However, the detailed relationship between their amino acid sequences and coacervation properties remains obscure because of the structural flexibility of ELPs. In this study, we synthesized a novel, dimeric ELP analogue (H-C(WPGVG) 3 -NH 2 ) 2 , henceforth abbreviated (CW3)2, and analyzed its self-assembly properties and structural factors as indicators of coacervation. Turbidity measurements showed that (CW3)2 demonstrated coacervation at a concentration much lower than that of its monomeric form and another ELP. In addition, the coacervate held water-soluble dye molecules. Thus, potent and distinct coacervation was obtained with a remarkably short sequence of (CW3)2. Furthermore, fluorescence microscopy, dynamic light scattering, and optical microscopy revealed that the coacervation of (CW3)2 was a stepwise process. The structural factors of (CW3)2 were analyzed by molecular dynamics simulations and circular dichroism spectroscopy. These measurements indicated that helical structures primarily consisting of proline and glycine became more disordered at high temperatures with concurrent, significant exposure of their hydrophobic surfaces. This extreme change in the hydrophobic surface contributes to the potent coacervation observed for (CW3)2. These results provide important insights into more efficient applications of ELPs and their analogues, as well as the coacervation mechanisms of ELP and elastin.

Biomechanical and morphological properties of the multiparous ovine vagina and effect of subsequent pregnancy.

PubMed

Rynkevic, Rita; Martins, Pedro; Hympanova, Lucie; Almeida, Henrique; Fernandes, Antonio A; Deprest, Jan

2017-05-24

Pelvic floor soft tissues undergo changes during the pregnancy. However, the degree and nature of this process is not completely characterized. This study investigates the effect of subsequent pregnancy on biomechanical and structural properties of ovine vagina. Vaginal wall from virgin, pregnant (in their third pregnancy) and parous (one year after third vaginal delivery) Swifter sheep (n=5 each) was harvested. Samples for biomechanics and histology, were cut in longitudinal axis (proximal and distal regions). Outcome measurements describing Young's modulus, ultimate stress and elongation were obtained from stress-strain curves. For histology samples were stained with Miller's Elastica staining. Collagen, elastin and muscle cells and myofibroblasts contents were estimated, using image processing techniques. Statistical analyses were performed in order to determine significant differences among experimental groups. Significant regional differences were identified. The proximal vagina was stiffer than distal, irrespective the reproductive status. During the pregnancy proximal vagina become more compliant than in parous (+47.45%) or virgin sheep (+64.35%). This coincided with lower collagen (-15 to -21%), higher elastin (+30 to +60%), and more smooth muscle cells (+17 to +37%). Vaginal tissue from parous ewes was weaker than of virgins, coinciding with lower collagen (-10%), higher elastin (+50%), more smooth muscle cells (+20%). It could be proposed that after pregnancy biomechanical properties of vagina do not recover to those of virgins. Since elastin has a significant influence on the compliance of soft tissues and collagen is the main "actor" regarding strength, histological analysis performed in this study justifies the mechanical behavior observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chitosan/γ-poly(glutamic acid) scaffolds with surface-modified albumin, elastin and poly-l-lysine for cartilage tissue engineering.

PubMed

Kuo, Yung-Chih; Ku, Hao-Fu; Rajesh, Rajendiran

2017-09-01

Cartilage has limited ability to self-repair due to the absence of blood vessels and nerves. The application of biomaterial scaffolds using biomimetic extracellular matrix (ECM)-related polymers has become an effective approach to production of engineered cartilage. Chitosan/γ-poly(glutamic acid) (γ-PGA) scaffolds with different mass ratios were prepared using genipin as a cross-linker and a freeze-drying method, and their surfaces were modified with elastin, human serum albumin (HSA) and poly-l-lysine (PLL). The scaffolds were formed through a complex between NH 3 + of chitosan and COO - of γ-PGA, confirmed by Fourier transform infrared spectroscopy, and exhibited an interconnected porous morphology in field emission scanning electron microscopy analysis. The prepared chitosan/γ-PGA scaffolds, at a 3:1 ratio, obtained the required porosity (90%), pore size (≥100μm), mechanical strength (compressive strength>4MPa, Young's modulus>4MPa) and biodegradation (30-60%) for articular cartilage tissue engineering applications. Surface modification of the scaffolds showed positive indications with improved activity toward cell proliferation (deoxyribonucleic acid), cell adhesion and ECM (glycoaminoglycans and type II collagen) secretion of bovine knee chondrocytes compared with unmodified scaffolds. In caspase-3 detection, elastin had a higher inhibitory effect on chondrocyte apoptosis in vitro, followed by HSA, and then PLL. We concluded that utilizing chitosan/γ-PGA scaffolds with surface active biomolecules, including elastin, HSA and PLL, can effectively promote the growth of chondrocytes, secrete ECM and improve the regenerative ability of cartilaginous tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of plasma anti-elastin antibodies for use as a diagnostic aid for chronic progressive lymphoedema in Belgian Draught Horses.

PubMed

De Keyser, K; Berth, M; Christensen, N; Willaert, S; Janssens, S; Ducatelle, R; Goddeeris, B M; De Cock, H E V; Buys, N

2015-01-15

Diagnosis of chronic progressive lymphoedema (CPL) in draught horses, including the Belgian Draught Horse, is mainly based on clinical evaluation of typical lower limb lesions. A deficient perilymphatic elastic support, caused by a pathological elastin degradation in skin and subcutis, has been suggested as a contributing factor for CPL. Elastin degradation products induce the generation of anti-elastin Ab (AEAb), detectable in horse serum by ELISA. For a clinically healthy group of draught horses, a significantly lower average AEAb-level than 3 clinically affected groups (mild, moderate and severe symptoms) was demonstrated previously. To improve CPL-diagnosis, we evaluated the AEAb-ELISA as an in vitro diagnostic aid in individual horses. Test reproducibility was assessed, performing assays independently in 2 laboratories on a total of 345 horses. Possible factors associated with AEAb-levels (age, gender, pregnancy, test lab and date of blood collection) were analyzed using a mixed statistical model. Results were reproducible in both laboratories. AEAb-levels in moderately and severely affected horses were significantly higher than in healthy horses. Nevertheless, this was only demonstrated in barren mares, and, there was a very large overlap between the clinical groups. Consequently, even when a high AEAb cut-off was handled to obtain a reasonable specificity of 90%, a very low sensitivity (21%) of AEAb for CPL-diagnosis was obtained. Results on the present sample demonstrate that the described ELISA procedure is of no use as a diagnostic test for CPL in individual horses. Copyright © 2014 Elsevier B.V. All rights reserved.

Expression and purification of ELP-intein-tagged target proteins in high cell density E. coli fermentation.

PubMed

Fong, Baley A; Wood, David W

2010-10-19

Elastin-like polypeptides (ELPs) are useful tools that can be used to non-chromatographically purify proteins. When paired with self-cleaving inteins, they can be used as economical self-cleaving purification tags. However, ELPs and ELP-tagged target proteins have been traditionally expressed using highly enriched media in shake flask cultures, which are generally not amenable to scale-up. In this work, we describe the high cell-density expression of self-cleaving ELP-tagged targets in a supplemented minimal medium at a 2.5 liter fermentation scale, with increased yields and purity compared to traditional shake flask cultures. This demonstration of ELP expression in supplemented minimal media is juxtaposed to previous expression of ELP tags in extract-based rich media. We also describe several sets of fed-batch conditions and their impact on ELP expression and growth medium cost. By using fed batch E. coli fermentation at high cell density, ELP-intein-tagged proteins can be expressed and purified at high yield with low cost. Further, the impact of media components and fermentation design can significantly impact the overall process cost, particularly at large scale. This work thus demonstrates an important advances in the scale up of self-cleaving ELP tag-mediated processes.

Expression and purification of ELP-intein-tagged target proteins in high cell density E. coli fermentation

PubMed Central

2010-01-01

Background Elastin-like polypeptides (ELPs) are useful tools that can be used to non-chromatographically purify proteins. When paired with self-cleaving inteins, they can be used as economical self-cleaving purification tags. However, ELPs and ELP-tagged target proteins have been traditionally expressed using highly enriched media in shake flask cultures, which are generally not amenable to scale-up. Results In this work, we describe the high cell-density expression of self-cleaving ELP-tagged targets in a supplemented minimal medium at a 2.5 liter fermentation scale, with increased yields and purity compared to traditional shake flask cultures. This demonstration of ELP expression in supplemented minimal media is juxtaposed to previous expression of ELP tags in extract-based rich media. We also describe several sets of fed-batch conditions and their impact on ELP expression and growth medium cost. Conclusions By using fed batch E. coli fermentation at high cell density, ELP-intein-tagged proteins can be expressed and purified at high yield with low cost. Further, the impact of media components and fermentation design can significantly impact the overall process cost, particularly at large scale. This work thus demonstrates an important advances in the scale up of self-cleaving ELP tag-mediated processes. PMID:20959011

Hyaluronan Hybrid Cooperative Complexes as a Novel Frontier for Cellular Bioprocesses Re-Activation

PubMed Central

Stellavato, Antonietta; Corsuto, Luisana; D’Agostino, Antonella; La Gatta, Annalisa; Diana, Paola; Bernini, Patrizia; De Rosa, Mario

2016-01-01

Hyaluronic Acid (HA)-based dermal formulations have rapidly gained a large consensus in aesthetic medicine and dermatology. HA, highly expressed in the Extracellular Matrix (ECM), acts as an activator of biological cascades, stimulating cell migration and proliferation, and operating as a regulator of the skin immune surveillance, through specific interactions with its receptors. HA may be used in topical formulations, as dermal inducer, for wound healing. Moreover, intradermal HA formulations (injectable HA) provide an attractive tool to counteract skin aging (e.g., facial wrinkles, dryness, and loss of elasticity) and restore normal dermal functions, through simple and minimally invasive procedures. Biological activity of a commercially available hyaluronic acid, Profhilo®, based on NAHYCO™ technology, was compared to H-HA or L-HA alone. The formation of hybrid cooperative complexes was confirmed by the sudden drop in η0 values in the rheological measurements. Besides, hybrid cooperative complexes proved stable to hyaluronidase (BTH) digestion. Using in vitro assays, based on keratinocytes, fibroblasts cells and on the Phenion® Full Thickness Skin Model 3D, hybrid cooperative complexes were compared to H-HA, widely used in biorevitalization procedures, and to L-HA, recently proposed as the most active fraction modulating the inflammatory response. Quantitative real-time PCR analyses were accomplished for the transcript quantification of collagens and elastin. Finally immunofluorescence staining permitted to evaluate the complete biosynthesis of all the molecules investigated. An increase in the expression levels of type I and type III collagen in fibroblasts and type IV and VII collagen in keratinocytes were found with the hybrid cooperative complexes, compared to untreated cells (CTR) and to the H-HA and L-HA treatments. The increase in elastin expression found in both cellular model and in the Phenion® Full Thickness Skin Model 3D also at longer time (up to 7 days), supports the clinically observed improvement of skin elasticity. The biomarkers analyzed suggest an increase of tissue remodeling in the presence of Profhilo®, probably due to the long lasting release and the concurrent action of the two HA components. PMID:27723763

Protective effect of dietary Alchemilla mollis on UVB-irradiated premature skin aging through regulation of transcription factor NFATc1 and Nrf2/ARE pathways.

PubMed

Hwang, Eunson; Ngo, Hien T T; Seo, Seul A; Park, Bom; Zhang, Mengyang; Yi, Tae-Hoo

2018-01-15

Alchemilla mollis (lady's mantle) is a common ingredient in skin care products. However, the protective mechanism of A. mollis against skin problems has not been elucidated. This study was to investigate the effects of A. mollis ethanolic extract (AM) on UVB-irradiated normal human dermal fibroblasts (NHDF) and hairless mice. The in vitro anti-photoaging effect of AM was performed in NHDFs. The antioxidant activities were assessed through DPPH, ABTS, and reactive oxygen species (ROS) assays. Matrix metalloproteinase 1 (MMP-1), IL-6, procollagen type I, and transforming growth factor-β1 (TGF-β1) were measured by kits. The protein levels of p-c-Jun, p-c-Fos, Nrf2, NQO-1, HO-1, nuclear NFATc1 and cytosolic p-NFATc1 were evaluated by western blotting. In in vivo, H&E and Masson's trichrome staining were carried out. Skin texture was analyzed using the roughness parameters. The expression of MMP-1, procollagen type I, TGF-β1 and elastin were measured by western blot. AM included gallic acid as an active constituent. AM exhibited a strong antioxidant effect by inhibiting DPPH and ABTS free radicals, as well as ROS production. It was also found to upregulate transforming growth factor β1, type I procollagen and elastin expression, and to downregulate matrix metalloproteinase-1 and interleukin-6 expression in AM-treated NHDFs under UVB irradiation. These effects were attributed to AP-1 and Nrf2/ARE signaling pathways. Significantly, it was demonstrated that AM regulated the UVB-induced NFATc1 dephosphorylation in nucleus. Based on dietary data, AM was effective for the prevention of wrinkle formation, skin thickening, water loss, and erythema in UVB-exposed mouse skin. Our data indicate that A. mollis provides protection from UVB exposure in both hairless mice skin in vivo and NHDFs in vitro. AM might therefore be useful as a cosmetic material and functional food for the prevention of UVB-induced human skin photoaging. Copyright © 2017 Elsevier GmbH. All rights reserved.

Lysyl oxidase interacts with AGE signalling to modulate collagen synthesis in polycystic ovarian tissue

PubMed Central

Papachroni, Katerina K; Piperi, Christina; Levidou, Georgia; Korkolopoulou, Penelope; Pawelczyk, Leszek; Diamanti-Kandarakis, Evanthia; Papavassiliou, Athanasios G

2010-01-01

Abstract Connective tissue components – collagen types I, III and IV – surrounding the ovarian follicles undergo drastic changes during ovulation. Abnormal collagen synthesis and increased volume and density of ovarian stroma characterize the polycystic ovary syndrome (PCOS). During the ovulatory process, collagen synthesis is regulated by prolyl hydroxylase and lysyl oxidase (LOX) activity in ovarian follicles. LOX catalyzes collagen and elastin cross-linking and plays essential role in coordinating the control of ovarian extracellular matrix (ECM) during follicular development. We have recently shown accumulation of advanced glycation end products (AGEs), molecules that stimulate ECM production and abnormal collagen cross-linking, in ovarian tissue. However, the possible link between LOX and AGEs-induced signalling in collagen production and stroma formation in ovarian tissue from PCOS remains elusive. The present study investigates the hypothesis of AGE signalling pathway interaction with LOX gene activity in polycystic ovarian (PCO) tissue. We show an increased distribution and co-localization of LOX, collagen type IV and AGE molecules in the PCO tissue compared to control, as well as augmented expression of AGE signalling mediators/effectors, phospho(p)-ERK, phospho(p)-c-Jun and nuclear factor κB (NF-κB) in pathological tissue. Moreover, we demonstrate binding of AGE-induced transcription factors, NF-κB and activator protein-1 (AP-1) on LOX promoter, indicating a possible involvement of AGEs in LOX gene regulation, which may account for the documented increase in LOX mRNA and protein levels compared to control. These findings suggest that deposition of excess collagen in PCO tissue that induces cystogenesis may, in part, be due to AGE-mediated stimulation of LOX activity. PMID:19583806

In planta production of ELPylated spidroin-based proteins results in non-cytotoxic biopolymers.

PubMed

Hauptmann, Valeska; Menzel, Matthias; Weichert, Nicola; Reimers, Kerstin; Spohn, Uwe; Conrad, Udo

2015-02-19

Spider silk is a tear-resistant and elastic biopolymer that has outstanding mechanical properties. Additionally, exiguous immunogenicity is anticipated for spider silks. Therefore, spider silk represents a potential ideal biomaterial for medical applications. All known spider silk proteins, so-called spidroins, reveal a composite nature of silk-specific units, allowing the recombinant production of individual and combined segments. In this report, a miniaturized spidroin gene, named VSO1 that contains repetitive motifs of MaSp1 has been synthesized and combined to form multimers of distinct lengths, which were heterologously expressed as elastin-like peptide (ELP) fusion proteins in tobacco. The elastic penetration moduli of layered proteins were analyzed for different spidroin-based biopolymers. Moreover, we present the first immunological analysis of synthetic spidroin-based biopolymers. Characterization of the binding behavior of the sera after immunization by competitive ELISA suggested that the humoral immune response is mainly directed against the fusion partner ELP. In addition, cytocompatibility studies with murine embryonic fibroblasts indicated that recombinant spidroin-based biopolymers, in solution or as coated proteins, are well tolerated. The results show that spidroin-based biopolymers can induce humoral immune responses that are dependent on the fusion partner and the overall protein structure. Furthermore, cytocompatibility assays gave no indication of spidroin-derived cytotoxicity, suggesting that recombinant produced biopolymers composed of spider silk-like repetitive elements are suitable for biomedical applications.

Tribbles 3: A potential player in diabetic aortic remodelling.

PubMed

Ti, Yun; Xie, Guo-lu; Wang, Zhi-hao; Ding, Wen-yuan; Zhang, Yun; Zhong, Ming; Zhang, Wei

2016-01-01

Tribbles 3, whose expression is up-regulated by insulin resistance, was confirmed to be involved in diabetic cardiomyopathy in our previous study. However, it is not known whether Tribbles 3 has a role on conduit arteries such as the aorta in diabetes. Type 2 diabetic rat model was induced by high-fat diet and low-dose streptozotocin. We evaluated the characteristics of diabetic rats by serial ultrasonography and histopathologic analyses of aortic wall architecture. Diabetic rats displayed increased aortic medial thickness, excessive collagen deposition, diminished elastic fibres and reduced vascular compliance together with Tribbles 3 overexpression. To further investigate the role of Tribbles 3 in aortic remodelling, we used Tribbles 3 gene silencing in vivo 12 weeks after onset of diabetes. Silence of Tribbles 3 significantly reversed pathological aortic remodelling without blood pressure modification. In Tribbles 3-small interfering RNA group, medial thickness and perivascular fibrosis were markedly decreased; moreover, there were prominent reductions in collagen content and collagen/elastin ratio, resulting in an improved arterial compliance. Additionally, with Tribbles 3 silencing, the diminished phosphorylation of PI3K/Akt was restored, and increased activation of MKK4/JNK was decreased. Silence of Tribbles 3 is potent in mediating reversal of aortic remodelling, implicating that Tribbles 3 is proposed to be a potential therapeutic target for vascular complication in diabetes. © The Author(s) 2015.

Resveratrol, 4' Acetoxy Resveratrol, R-equol, Racemic Equol or S-equol as Cosmeceuticals to Improve Dermal Health.

PubMed

Lephart, Edwin D

2017-06-03

Phytochemicals are botanical compounds used in dermatology applications as cosmeceuticals to improve skin health. Resveratrol and equol are two of the best-known polyphenolic or phytoestrogens having similar chemical structures and some overlapping biological functions to 17β-estradiol. Human skin gene expression was reviewed for 28 different biomarkers when resveratrol, 4' acetoxy resveratrol (4AR), R -equol, racemic equol or S -equol were tested. Sirtuin 1 activator (SIRT 1) was stimulated by resveratrol and 4AR only. Resveratrol, R -equol and racemic equol were effective on the aging biomarkers proliferating cell nuclear factor (PCNA), nerve growth factor (NGF), 5α-reductase and the calcium binding proteins S100 A8 and A9. Racemic equol and 4AR displayed among the highest levels for the collagens, elastin and tissue inhibitor of the matrix metalloproteinase 1 (TIMP 1). S -equol displayed the lowest level of effectiveness compared to the other compounds. The 4AR analog was more effective compared to resveratrol by 1.6-fold. R -equol and racemic equol were almost equal in potency displaying greater inhibition vs. resveratrol or its 4' analog for the matrix metalloproteinases (MMPs), but among the inflammatory biomarkers, resveratrol, 4AR, R -equol and racemic equol displayed high inhibition. Thus, these cosmeceuticals display promise to improve dermal health; however, further study is warranted to understand how phytochemicals protect/enhance the skin.

Characterization of atherosclerotic plaques by cross-polarization optical coherence tomography

NASA Astrophysics Data System (ADS)

Gubarkova, Ekaterina V.; Dudenkova, Varvara V.; Feldchtein, Felix I.; Timofeeva, Lidia B.; Kiseleva, Elena B.; Kuznetsov, Sergei S.; Moiseev, Alexander A.; Gelikonov, Gregory V.; Vitkin, Alex I.; Gladkova, Natalia D.

2016-02-01

We combined cross-polarization optical coherence tomography (CP OCT) and non-linear microscopy based on second harmonic generation (SHG) and two-photon-excited fluorescence (2PEF) to assess collagen and elastin fibers in the development of the atherosclerotic plaque (AP). The study shows potential of CP OCT for the assessment of collagen and elastin fibers condition in atherosclerotic arteries. Specifically, the additional information afforded by CP OCT, related to birefringence and cross-scattering properties of arterial tissues, may improve the robustness and accuracy of assessment about the microstructure and composition of the plaque for different stages of atherosclerosis.

Biocompatibility of two model elastin-like recombinamer-based hydrogels formed through physical or chemical cross-linking for various applications in tissue engineering and regenerative medicine.

PubMed

Ibáñez-Fonseca, Arturo; Ramos, Teresa L; González de Torre, Israel; Sánchez-Abarca, Luis Ignacio; Muntión, Sandra; Arias, Francisco Javier; Del Cañizo, María Consuelo; Alonso, Matilde; Sánchez-Guijo, Fermín; Rodríguez-Cabello, José Carlos

2018-03-01

Biocompatibility studies, especially innate immunity induction, in vitro and in vivo cytotoxicity, and fibrosis, are often lacking for many novel biomaterials including recombinant protein-based ones, such as elastin-like recombinamers (ELRs), and has not been extensively explored in the scientific literature, in contrast to traditional biomaterials. Herein, we present the results from a set of experiments designed to elucidate the preliminary biocompatibility of 2 types of ELRs that are able to form extracellular matrix-like hydrogels through either physical or chemical cross-linking both of which are intended for different applications in tissue engineering and regenerative medicine. Initially, we present in vitro cytocompatibility results obtained upon culturing human umbilical vein endothelial cells on ELR substrates, showing optimal proliferation up to 9 days. Regarding in vivo cytocompatibility, luciferase-expressing hMSCs were viable for at least 4 weeks in terms of bioluminescence emission when embedded in ELR hydrogels and injected subcutaneously into immunosuppressed mice. Furthermore, both types of ELR-based hydrogels were injected subcutaneously in immunocompetent mice and serum TNFα, IL-1β, IL-4, IL-6, and IL-10 concentrations were measured by enzyme-linked immunosorbent assay, confirming the lack of inflammatory response, as also observed upon macroscopic and histological evaluation. All these findings suggest that both types of ELRs possess broad biocompatibility, thus making them very promising for tissue engineering and regenerative medicine-related applications. Copyright © 2017 John Wiley & Sons, Ltd.

Use of a collagen-elastin matrix as transport carrier system to transfer proliferating epidermal cells to human dermis in vitro.

PubMed

Waaijman, Taco; Breetveld, Melanie; Ulrich, Magda; Middelkoop, Esther; Scheper, Rik J; Gibbs, Susan

2010-01-01

This in vitro study describes a novel cell culture, transport, and transfer protocol that may be highly suitable for delivering cultured proliferating keratinocytes and melanocytes to large open skin wounds (e.g., burns). We have taken into account previous limitations identified using other keratinocyte transfer techniques, such as regulatory issues, stability of keratinocytes during transport (single cell suspensions undergo terminal differentiation), ease of handling during application, and the degree of epidermal blistering resulting after transplantation (both related to transplanting keratinocyte sheets). Large numbers of proliferating epidermal cells (EC) (keratinocytes and melanocytes) were generated within 10-14 days and seeded onto a three-dimensional matrix composed of elastin and collagen types I, III, and V (Matriderm®), which enabled easy and stable transport of the EC for up to 24 h under ambient conditions. All culture conditions were in accordance with the regulations set by the Dutch Central Committee on Research Involving Human Subjects (CCMO). As an in vitro model system for clinical in vivo transfer, the EC were then transferred from Matriderm onto human acellular dermis during a period of 3 days. After transfer the EC maintained the ability to regenerate into a fully differentiated epidermis containing melanocytes on the human dermis. Proliferating keratinocytes were located in the basal layer and keratin-10 expression was located in differentiating suprabasal layers similar to that found in human epidermis. No blistering was observed (separation of the epidermis from the basement membrane). Keratin-6 expression was strongly upregulated in the regenerating epidermis similar to normal wound healing. In summary, we show that EC-Matriderm contains viable, metabolically active keratinocytes and melanocytes cultured in a manner that permits easy transportation and contains epidermal cells with the potential to form a pigmented reconstructed epidermis. This in vitro study has produced a robust protocol that is ready for clinical studies in the future.

AT1-receptor blockade attenuates outward aortic remodeling associated with diet-induced obesity in mice.

PubMed

Krueger, Friedrich; Kappert, Kai; Foryst-Ludwig, Anna; Kramer, Frederike; Clemenz, Markus; Grzesiak, Aleksandra; Sommerfeld, Manuela; Paul Frese, Jan; Greiner, Andreas; Kintscher, Ulrich; Unger, Thomas; Kaschina, Elena

2017-08-01

The renin-angiotensin system (RAS) and obesity have been implicated in vascular outward remodeling, including aneurysms, but the precise mechanisms are not yet understood. We investigated the effect of the angiotensin receptor type 1 (AT1-receptor) antagonist telmisartan on aortic outward remodeling in a diet-induced obesity model in mice. C57/Black6J mice were fed either a low-fat diet (LFD) or a high-fat diet (HFD) for 14 weeks. One group of HFD mice was additionally exposed to telmisartan (3 mg/kg per day) for the last 4 weeks. HFD led to aortic outward remodeling, characterized by increased proteolysis, along with structural changes, such as fragmentation of elastic fibers and decreased elastin content. Vascular damage was associated with up-regulation of matrix metalloproteinase (MMP)-2 (MMP-2), MMP-3, MMP-12, cathepsin D, and cathepsin B. HFD aortae exhibited an enhanced inflammatory status, characterized by tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) colocalized with adipocytes in the adventitia. HFD resulted in a significant increase in aortic dimensions, evident by ultrasound measurements. Telmisartan abolished aortic dilatation and preserved elastin content. HFD induced enhanced expression of aortic MMP-2, MMP-9, and TNF-α was abrogated by telmisartan. Adventitial proteolytic and inflammatory factors were also examined in samples from human abdominal aneurysms. The expression of TNF-α, IL-1β, and MMP-9 was higher in the adventitial fat of diseased vessels compared with healthy tissues. Finally, adipocytes treated with TNF-α showed enhanced MMP-2, MMP-3, and cathepsin D, which was prevented by telmisartan. Taken together, HFD in mice induced aortic dilatation with up-regulation of matrix degrading and inflammatory pathways similar to those seen in human aortic aneurysmatic tissue. The HFD-induced vascular pathology was reduced by AT1-receptor antagonist telmisartan. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Evidence for age-dependent air-space enlargement contributing to loss of lung tissue elastic recoil pressure and increased shear modulus in older age.

PubMed

Subramaniam, K; Kumar, H; Tawhai, M H

2017-07-01

As a normal part of mature aging, lung tissue undergoes microstructural changes such as alveolar air-space enlargement and redistribution of collagen and elastin away from the alveolar duct. The older lung also experiences an associated decrease in elastic recoil pressure and an increase in specific tissue elastic moduli, but how this relates mechanistically to microstructural remodeling is not well-understood. In this study, we use a structure-based mechanics analysis to elucidate the contributions of age-related air-space enlargement and redistribution of elastin and collagen to loss of lung elastic recoil pressure and increase in tissue elastic moduli. Our results show that age-related geometric changes can result in reduction of elastic recoil pressure and increase in shear and bulk moduli, which is consistent with published experimental data. All elastic moduli were sensitive to the distribution of stiffness (representing elastic fiber density) in the alveolar wall, with homogenous stiffness near the duct and through the septae resulting in a more compliant tissue. The preferential distribution of elastic proteins around the alveolar duct in the healthy young adult lung therefore provides for a more elastic tissue. NEW & NOTEWORTHY We use a structure-based mechanics analysis to correlate air-space enlargement and redistribution of elastin and collagen to age-related changes in the mechanical behavior of lung parenchyma. Our study highlights that both the cause (redistribution of elastin and collagen) and the structural effect (alveolar air-space enlargement) contribute to decline in lung tissue elastic recoil with age; these results are consistent with published data and provide a new avenue for understanding the mechanics of the older lung. Copyright © 2017 the American Physiological Society.

Segmental and age differences in the elastin network, collagen, and smooth muscle phenotype in the tunica media of the porcine aorta.

PubMed

Tonar, Zbyněk; Kubíková, Tereza; Prior, Claudia; Demjén, Erna; Liška, Václav; Králíčková, Milena; Witter, Kirsti

2015-09-01

The porcine aorta is often used in studies on morphology, pathology, transplantation surgery, vascular and endovascular surgery, and biomechanics of the large arteries. Using quantitative histology and stereology, we estimated the area fraction of elastin, collagen, alpha-smooth muscle actin, vimentin, and desmin within the tunica media in 123 tissue samples collected from five segments (thoracic ascending aorta; aortic arch; thoracic descending aorta; suprarenal abdominal aorta; and infrarenal abdominal aorta) of porcine aortae from growing domestic pigs (n=25), ranging in age from 0 to 230 days. The descending thoracic aorta had the greatest elastin fraction, which decreased proximally toward the aortic arch as well as distally toward the abdominal aorta. Abdominal aortic segments had the highest fraction of actin, desmin, and vimentin positivity and all of these vascular smooth muscle markers were lower in the thoracic aortic segments. No quantitative differences were found when comparing the suprarenal abdominal segments with the infrarenal abdominal segments. The area fraction of actin within the media was comparable in all age groups and it was proportional to the postnatal growth. Thicker aortic segments had more elastin and collagen with fewer contractile cells. The collagen fraction decreased from ascending aorta and aortic arch toward the descending aorta. By revealing the variability of the quantitative composition of the porcine aorta, the results are suitable for planning experiments with the porcine aorta as a model, i.e. power test analyses and estimating the number of samples necessary to achieving a desirable level of precision. The complete primary morphometric data, in the form of continuous variables, are made publicly available for biomechanical modeling of site-dependent distensibility and compliance of the porcine aorta. Copyright © 2015 Elsevier GmbH. All rights reserved.

An In Vivo Study of Composite Microgels Based on Hyaluronic Acid and Gelatin for the Reconstruction of Surgically Injured Rat Vocal Folds

PubMed Central

Coppoolse, Jiska M. S.; Van Kooten, T. G.; Heris, Hossein K.; Mongeau, Luc; Li, Nicole Y. K.; Thibeault, Susan L.; Pitaro, Jacob; Akinpelu, Olubunmi; Daniel, Sam J.

2016-01-01

Purpose The objective of this study was to investigate local injection with a hierarchically microstructured hyaluronic acid–gelatin (HA-Ge) hydrogel for the treatment of acute vocal fold injury using a rat model. Method Vocal fold stripping was performed unilaterally in 108 Sprague-Dawley rats. A volume of 25 ml saline (placebo controls), HA-bulk, or HA-Ge hydrogel was injected into the lamina propria (LP) 5 days after surgery. The vocal folds were harvested at 3, 14, and 28 days after injection and analyzed using hematoxylin and eosin staining and immunohistochemistry staining for macrophages, myofibroblasts, elastin, collagen type I, and collagen type III. Results The macrophage count was statistically significantly lower in the HA-Ge group than in the saline group (p < .05) at Day 28. Results suggested that the HA-Ge injection did not induce inflammatory or rejection response. Myofibroblast counts and elastin were statistically insignificant across treatment groups at all time points. Increased elastin deposition was qualitatively observed in both HA groups from Day 3 to Day 28, and not in the saline group. Significantly more elastin was observed in the HA-bulk group than in the uninjured group at Day 28. Significantly more collagen type I was observed in the HA-bulk and HA-Ge groups than in the saline group (p < .05) at Day 28. The collagen type I concentration in the HA-Ge and saline groups was found to be comparable to that in the uninjured controls at Day 28. The concentration of collagen type III in all treatment groups was similar to that in uninjured controls at Day 28. Conclusion Local HA-Ge and HA-bulk injections for acute injured vocal folds were biocompatible and did not induce adverse response. PMID:24687141

Brain arterial aging and its relationship to Alzheimer dementia

PubMed Central

Honig, Lawrence; Elkind, Mitchell S.V.; Mohr, Jay P.; Goldman, James; Dwork, Andrew J.; Morgello, Susan; Marshall, Randolph S.

2016-01-01

Objective: To test the hypothesis that brain arterial aging is associated with the pathologic diagnosis of Alzheimer disease (AD). Methods: Brain large arteries were assessed for diameter, gaps in the internal elastic lamina (IEL), luminal stenosis, atherosclerosis, and lumen-to-wall ratio. Elastin, collagen, and amyloid were assessed with Van Gieson, trichrome, and Congo red staining intensities, and quantified automatically. Brain infarcts and AD (defined pathologically) were assessed at autopsy. We created a brain arterial aging (BAA) score with arterial characteristics associated with aging after adjusting for demographic and clinical variables using cross-sectional generalized linear models. Results: We studied 194 autopsied brains, 25 (13%) of which had autopsy evidence of AD. Brain arterial aging consisted of higher interadventitial and lumen diameters, thickening of the wall, increased prevalence of IEL gaps, concentric intima thickening, elastin loss, increased amyloid deposition, and a higher IEL proportion without changes in lumen-to-wall ratio. In multivariable analysis, a high IEL proportion (B = 1.96, p = 0.030), thick media (B = 3.50, p = 0.001), elastin loss (B = 6.16, p < 0.001), IEL gaps (B = 3.14, p = 0.023), and concentric intima thickening (B = 7.19, p < 0.001) were used to create the BAA score. Adjusting for demographics, vascular risk factors, atherosclerosis, and brain infarcts, the BAA score was associated with AD (B = 0.022, p = 0.002). Conclusions: Aging of brain large arteries is characterized by arterial dilation with a commensurate wall thickening, elastin loss, and IEL gaps. Greater intensity of arterial aging was associated with AD independently of atherosclerosis and brain infarcts. Understanding the drivers of arterial aging may advance the knowledge of the pathophysiology of AD. PMID:26984942

Brain arterial aging and its relationship to Alzheimer dementia.

PubMed

Gutierrez, Jose; Honig, Lawrence; Elkind, Mitchell S V; Mohr, Jay P; Goldman, James; Dwork, Andrew J; Morgello, Susan; Marshall, Randolph S

2016-04-19

To test the hypothesis that brain arterial aging is associated with the pathologic diagnosis of Alzheimer disease (AD). Brain large arteries were assessed for diameter, gaps in the internal elastic lamina (IEL), luminal stenosis, atherosclerosis, and lumen-to-wall ratio. Elastin, collagen, and amyloid were assessed with Van Gieson, trichrome, and Congo red staining intensities, and quantified automatically. Brain infarcts and AD (defined pathologically) were assessed at autopsy. We created a brain arterial aging (BAA) score with arterial characteristics associated with aging after adjusting for demographic and clinical variables using cross-sectional generalized linear models. We studied 194 autopsied brains, 25 (13%) of which had autopsy evidence of AD. Brain arterial aging consisted of higher interadventitial and lumen diameters, thickening of the wall, increased prevalence of IEL gaps, concentric intima thickening, elastin loss, increased amyloid deposition, and a higher IEL proportion without changes in lumen-to-wall ratio. In multivariable analysis, a high IEL proportion (B = 1.96, p = 0.030), thick media (B = 3.50, p = 0.001), elastin loss (B = 6.16, p < 0.001), IEL gaps (B = 3.14, p = 0.023), and concentric intima thickening (B = 7.19, p < 0.001) were used to create the BAA score. Adjusting for demographics, vascular risk factors, atherosclerosis, and brain infarcts, the BAA score was associated with AD (B = 0.022, p = 0.002). Aging of brain large arteries is characterized by arterial dilation with a commensurate wall thickening, elastin loss, and IEL gaps. Greater intensity of arterial aging was associated with AD independently of atherosclerosis and brain infarcts. Understanding the drivers of arterial aging may advance the knowledge of the pathophysiology of AD. © 2016 American Academy of Neurology.

Prevention of abdominal aortic aneurysm progression by targeted inhibition of matrix metalloproteinase activity with batimastat-loaded nanoparticles.

PubMed

Nosoudi, Nasim; Nahar-Gohad, Pranjal; Sinha, Aditi; Chowdhury, Aniqa; Gerard, Patrick; Carsten, Christopher G; Gray, Bruce H; Vyavahare, Naren R

2015-11-06

Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of development and progression of abdominal aortic aneurysms. Systemic treatments of MMP inhibitors have shown effectiveness in animal models, but it did not translate to clinical success either because of low doses used or systemic side effects of MMP inhibitors. We propose a targeted nanoparticle (NP)-based delivery of MMP inhibitor at low doses to the abdominal aortic aneurysms site. Such therapy will be an attractive option for preventing expansion of aneurysms in patients without systemic side effects. Our previous study showed that poly(d,l-lactide) NPs conjugated with an antielastin antibody could be targeted to the site of an aneurysm in a rat model of abdominal aortic aneurysms. In the study reported here, we tested whether such targeted NPs could deliver the MMP inhibitor batimastat (BB-94) to the site of an aneurysm and prevent aneurysmal growth. Poly(d,l-lactide) NPs were loaded with BB-94 and conjugated with an elastin antibody. Intravenous injections of elastin antibody-conjugated BB-94-loaded NPs targeted the site of aneurysms and delivered BB-94 in a calcium chloride injury-induced abdominal aortic aneurysms in rats. Such targeted delivery inhibited MMP activity, elastin degradation, calcification, and aneurysmal development in the aorta (269% expansion in control versus 40% elastin antibody-conjugated BB-94-loaded NPs) at a low dose of BB-94. The systemic administration of BB-94 alone at the same dose was ineffective in producing MMP inhibition. Targeted delivery of MMP inhibitors using NPs may be an attractive strategy to inhibit aneurysmal progression. © 2015 American Heart Association, Inc.

Tenascin-X, Collagen, Elastin and the Ehlers-Danlos Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bristow, James; Carey, William; Schalkwijk, Joost

2005-08-31

Tenascin-X is an extracellular matrix protein initially identified because of its overlap with the human CYP21B gene. Because studies of gene and protein function of other tenascins had been poorly predictive of essential functions in vivo, we used a genetic approach that critically relied on an understanding of the genomic locus to uncover an association between inactivating tenascin-X mutations and novel recessive and dominant forms of Ehlers-Danlos syndrome. Tenascin-X provides the first example of a gene outside of the fibrillar collagens and their processing enzymes that causes Ehlers-Danlos syndrome. Tenascin-X null mice recapitulate the skin findings of the human disease,more » confirming a causative role for this gene in Ehlers-Danlos syndrome. Further evaluation of these mice showed that tenascin-X is an important regulator of collagen deposition in vivo, suggesting a novel mechanism of disease in this form of Ehlers-Danlos syndrome. Further studies suggest that tenascin-X may do this through both direct and indirect interactions with the collagen fibril. Recent studies show that TNX effects on matrix extend beyond the collagen to the elastogenic pathway and matrix remodeling enzymes. Tenascin-X serves as a compelling example of how human experiments of nature can guide us to an understanding of genes whose function may not be evident from their sequence or in vitro studies of their encoded proteins.« less

Multicolor Luminescence from Conjugates of Genetically Encoded Elastin-like Polymers and Terpyridine-Lanthanides

DOE PAGES

Ghosh, Koushik; Balog, Eva Rose M.; Kahn, Jennifer L.; ...

2015-08-20

Functional hybrid materials with optically active metal-ligand moieties embedded within a polymer matrix have a great potential in (bio)materials science, including applications in light-emitting diode devices. Here, we report a simple strategy to incorporate terpyridine derivatives into the side chains of elastin-like polymers (ELPs). The further binding of trivalent lanthanide ions with the terpyridine ligands generated an array of photoluminescence ranging from the visible to the near-infrared regions. Lastly, as thin films, these ELP-based optical materials also exhibited distinct morphologies that depend upon the temperature of the aqueous solutions from which the hybrid polymers were spin coated or drop cast.

Elastin Degradation by Cathepsin V Requires Two Exosites*

PubMed Central

Du, Xin; Chen, Nelson L. H.; Wong, Andre; Craik, Charles S.; Brömme, Dieter

2013-01-01

Cathepsin V is a highly effective elastase and has been implicated in physiological and pathological extracellular matrix degradation. However, its mechanism of action remains elusive. Whereas human cathepsin V exhibits a potent elastolytic activity, the structurally homologous cathepsin L, which shares a 78% amino acid sequence, has only a minimal proteolytic activity toward insoluble elastin. This suggests that there are distinct structural domains that play an important role in elastinolysis. In this study, a total of 11 chimeras of cathepsins V and L were generated to identify elastin-binding domains in cathepsin V. Evaluation of these chimeras revealed two exosites contributing to the elastolytic activity of cathepsin V that are distant from the active cleft of the protease and are located in surface loop regions. Replacement of exosite 1 or 2 with analogous residues from cathepsin L led to a 75 and 43% loss in the elastolytic activity, respectively. Replacement of both exosites yielded a non-elastase variant similar to that of cathepsin L. Identification of these exosites may contribute to the design of inhibitors that will only affect the elastolytic activity of cysteine cathepsins without interfering with other physiological protease functions. PMID:24121514

Semicarbazide-sensitive amine oxidase and extracellular matrix deposition by smooth-muscle cells

NASA Technical Reports Server (NTRS)

Langford, Shannon D.; Trent, Margaret B.; Boor, Paul J.

2002-01-01

We have recently reported in vivo disruption of collagen and elastin architecture within blood vessel walls resulting from the selective inhibition of the enzyme semicarbazide-sensitive amine oxidase (SSAO). This study further investigates the effects of SSAO inhibition on extracellular matrix deposition by smooth-muscle cells (SMCs) cultured from neonatal rat hearts. SMCs were characterized, SSAO activity was measured, and soluble and insoluble collagen and elastin in the extracellular matrix (ECM) were quantified. Cultured neonatal rat heart SMC exhibited a monotypic synthetic phenotype that likely represents a myofibroblast. Detectable levels of SSAO activity present throughout 30-d culture peaked at 7-14 d, coinciding with the production of ECM. The addition of enzyme inhibitors and alternate SSAO substrates (benzylamine) produced varied and, in some cases, marked changes in SSAO activity as well as in the composition of mature and soluble matrix components. Similar to our previous in vivo findings, in vitro SSAO inhibition produced aberrations in collagen and elastin deposition by heart SMC. Because changes in SSAO activity are associated with cardiovascular pathologic states, this enzyme may play a protective or modulating role by regulating ECM production during pathologic insult.

Architecturally defined scaffolds from synthetic collagen and elastin analogues for the fabrication of bioengineered tissues

NASA Astrophysics Data System (ADS)

Caves, Jeffrey Morris

The microstructure and mechanics of collagen and elastin protein fiber networks dictate the mechanical responses of all soft tissues and related organ systems. In this project, we endeavored to meet or exceed native tissue biomechanical properties through mimicry of these extracellular matrix components with synthetic collagen fiber and a recombinant elastin-like protein polymer. Significantly, this work led to the development of a framework for the design and fabrication of protein-based tissue substitutes with enhanced strength, resilience, anisotropy, and more. We began with the development of a spinning process for scalable production of synthetic collagen fiber. Fiber with an elliptical cross-section of 53 +/- 14 by 21 +/- 3 mum and an ultimate tensile strength of 90 +/- 19 MPa was continuously produced at 60 meters per hour from an ultrafiltered collagen solution. The starting collagen concentration, flowrate, and needle size could be adjusted to control fiber size. The fiber was characterized with mechanical analysis, micro-differential scanning calorimetry, transmission electron microscopy, second harmonic generation analysis, and subcutaneous murine implant. We subsequently describe the scalable, semi-automated fabrication of elastin-like protein sheets reinforced with synthetic collagen fibers that can be positioned in a precisely defined three-dimensional hierarchical pattern. Multilamellar, fiber-reinforced elastic protein sheets were constructed with controlled fiber orientation and volume fraction. Structures were analyzed with scanning electron microscopy, transmission electron microscopy, and digital volumetric imaging. The effect of fiber orientation and volume fraction on Young's Modulus, yield stress, ultimate tensile stress, strain-to-failure, and resilience was evaluated in uniaxial tension. Increased fiber volume fraction and alignment with applied deformation significantly increased Young's Modulus, resilience, and yield stress. Highly extensible, elastic tissues display a functionally important mechanical transition from low to high modulus deformation at a strain dictated by the crimped microstructure of native collagen fiber. We report the fabrication of dense arrays of microcrimped synthetic collagen fiber embedded in elastin-like protein lamellae that mimic this aspect of tissue mechanics. Microcrimped fiber arrays were characterized with scanning electron microscopy, confocal laser scanning microscopy, and uniaxial tension analysis. Crimp wavelength was 143 +/- 5 mum. The degree of crimping was varied from 3.1% to 9.4%, and corresponded to mechanical modulus transitions at 4.6% and 13.3% strain. Up to 1000 cycles of tensile loading did not substantially alter microcrimp morphology. We designed and prototyped a series of small-diameter vascular grafts consisting of elastin-like protein reinforced with controlled volume fractions and orientations of collagen fiber. A pressure-diameter system was developed and implemented to study the effects of fiber distribution on graft mechanics. The optimal design satisfied target properties with suture retention strength of 173 +/- 4 g-f, burst strength of 1483 +/- 143 mm Hg, and compliance of 5.1 +/- 0.8 %/100 mm Hg.

Heterozygous Vangl2Looptail mice reveal novel roles for the planar cell polarity pathway in adult lung homeostasis and repair

PubMed Central

Poobalasingam, Thanushiyan; Yates, Laura L.; Walker, Simone A.; Pereira, Miguel; Gross, Nina Y.; Ali, Akmol; Kolatsi-Joannou, Maria; Jarvelin, Marjo-Riitta; Pekkanen, Juha; Papakrivopoulou, Eugenia; Long, David A.; Griffiths, Mark; Wagner, Darcy; Königshoff, Melanie; Hind, Matthew; Minelli, Cosetta; Lloyd, Clare M.

2017-01-01

ABSTRACT Lung diseases impose a huge economic and health burden worldwide. A key aspect of several adult lung diseases, such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), including emphysema, is aberrant tissue repair, which leads to an accumulation of damage and impaired respiratory function. Currently, there are few effective treatments available for these diseases and their incidence is rising. The planar cell polarity (PCP) pathway is critical for the embryonic development of many organs, including kidney and lung. We have previously shown that perturbation of the PCP pathway impairs tissue morphogenesis, which disrupts the number and shape of epithelial tubes formed within these organs during embryogenesis. However, very little is known about the role of the PCP pathway beyond birth, partly because of the perinatal lethality of many PCP mouse mutant lines. Here, we investigate heterozygous Looptail (Lp) mice, in which a single copy of the core PCP gene, Vangl2, is disrupted. We show that these mice are viable but display severe airspace enlargement and impaired adult lung function. Underlying these defects, we find that Vangl2Lp/+ lungs exhibit altered distribution of actin microfilaments and abnormal regulation of the actin-modifying protein cofilin. In addition, we show that Vangl2Lp/+ lungs exhibit many of the hallmarks of tissue damage, including an altered macrophage population, abnormal elastin deposition and elevated levels of the elastin-modifying enzyme, Mmp12, all of which are observed in emphysema. In vitro, disruption of VANGL2 impairs directed cell migration and reduces the rate of repair following scratch wounding of human alveolar epithelial cells. Moreover, using population data from a birth cohort of young adults, all aged 31, we found evidence of an interactive effect between VANGL2 and smoking on lung function. Finally, we show that PCP genes VANGL2 and SCRIB are significantly downregulated in lung tissue from patients with emphysema. Our data reveal an important novel role for the PCP pathway in adult lung homeostasis and repair and shed new light on the genetic factors which may modify destructive lung diseases such as emphysema. PMID:28237967

Integrin-binding elastin-like polypeptide as an in situ gelling delivery matrix enhances the therapeutic efficacy of adipose stem cells in healing full-thickness cutaneous wounds.

PubMed

Choi, Seong-Kyoon; Park, Jin-Kyu; Kim, Jung-Hee; Lee, Kyeong-Min; Kim, Enjoo; Jeong, Kyu-Shik; Jeon, Won Bae

2016-09-10

One crucial issue in stem cell therapy used for tissue repair is often the lack of selective carriers to deliver stem cells to the site of injury where the native extracellular matrix is pathologically damaged or lost. Therefore, it is necessary to develop a biomaterial that is permissive to stem cells and is suitable to replace injured or missing matrix. The major aim of this study is to investigate the potential of an RGD-containing elastin-like polypeptide (REP) with the structure TGPG[VGRGD(VGVPG)6]20WPC to engraft adipose stem cells (ASC) to full-thickness excisional wounds in mice. We implanted REP into the wound defects via body temperature-induced in situ aggregation. Engrafted REP exhibited a half-life of 2.6days in the wounds and did not elicit any pathological immune responses. REP itself significantly accelerated wound closure and reepithelialization and upregulated the expression of dermal tissue components. A combined administration of REP and ASC formed a hydrogel-like ASC/REP composite, which provided better neovascularization than the use of ASCs alone and increased the viability of transplanted ASC, improving overall wound healing. In vitro and in vivo mechanistic investigations suggested that REP enhances ASC survival at least in part via the Fak/Src adhesion-induced upregulation of Mek/Erk and PI3K/Akt survival pathways. We conclude that REP is a promising therapeutic agent for the improvement of stem cell-based therapy for enhanced tissue regeneration and repair. Copyright © 2016 Elsevier B.V. All rights reserved.

Utility of Adipocyte Fractions in Fat Grafting in an Athymic Rat Model.

PubMed

Akgul, Yucel; Constantine, Ryan; Bartels, Mason; Scherer, Philipp; Davis, Kathryn; Kenkel, Jeffrey M

2018-05-02

Multiple processing and handling methods of autologous fat yields to variations in graft retention and viability, which results in unpredictable clinical outcomes. This study aims to understand the skin effects of fat graft preparations that contain a varying ratio of free-lipid and stem-cell-bearing stromal vascular fractions (SVF). Lipoaspirates from consenting patients were processed into emulsified fat and then SVF and adipocyte fractions (free-lipid). SVF enriched with 0%, 5%, and 15% free-lipid were grafted along the dorsum of athymic rats. The xenografts were collected 45 days after grafting and then prepped for immunostaining. Xenografts resulted in viable tissue mass under the panniculus carnosus of rats as confirmed with human specific markers. A low percentage of human cells was also detected in the lower reticular dermis. Although grafts with SVF formed adipocytes of normal architecture, grafts formed with free-lipid alone resulted in large lipid vacuoles in varying sizes. Among graft preparations, SVF with 10% free-lipid resulted in much-developed adipocyte architecture with collagen and elastin. Compared with SVF alone grafts, SVF with free-lipid had higher CD44 expression, suggesting a localized immune response of adipocytes. Current studies suggest that SVF enriched with approximately 10% free-lipid provides the best conditions for fat graft differentiation into viable fat tissue formation as well as collagen and elastin production to provide mechanical support for overlaying skin in an athymic rat model. Additionally, application of this therapeutic modality in a simple clinical setting may offer a practical way to concentrate SVF with free-lipid in a small volume for the improvement of clinical defects.

Structural remodeling of coronary resistance arteries: effects of age and exercise training

PubMed Central

Hanna, Mina A.; Taylor, Curtis R.; Chen, Bei; La, Hae-Sun; Maraj, Joshua J.; Kilar, Cody R.; Behnke, Bradley J.; Delp, Michael D.

2014-01-01

Age is known to induce remodeling and stiffening of large-conduit arteries; however, little is known of the effects of age on remodeling and mechanical properties of coronary resistance arteries. We employed a rat model of aging to investigate whether 1) age increases wall thickness and stiffness of coronary resistance arteries, and 2) exercise training reverses putative age-induced increases in wall thickness and stiffness of coronary resistance arteries. Young (4 mo) and old (21 mo) Fischer 344 rats remained sedentary or underwent 10 wk of treadmill exercise training. Coronary resistance arteries were isolated for determination of wall-to-lumen ratio, effective elastic modulus, and active and passive responses to changes in intraluminal pressure. Elastin and collagen content of the vascular wall were assessed histologically. Wall-to-lumen ratio increased with age, but this increase was reversed by exercise training. In contrast, age reduced stiffness, and exercise training increased stiffness in coronary resistance arteries from old rats. Myogenic responsiveness was reduced with age and restored by exercise training. Collagen-to-elastin ratio (C/E) of the wall did not change with age and was reduced with exercise training in arteries from old rats. Thus age induces hypertrophic remodeling of the vessel wall and reduces the stiffness and myogenic function of coronary resistance arteries. Exercise training reduces wall-to-lumen ratio, increases wall stiffness, and restores myogenic function in aged coronary resistance arteries. The restorative effect of exercise training on myogenic function of coronary resistance arteries may be due to both changes in vascular smooth muscle phenotype and expression of extracellular matrix proteins. PMID:25059239

Tuning Thermoresponsive Properties of Cationic Elastin-like Polypeptides by Varying Counterions and Side-Chains.

PubMed

Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

2017-05-17

We report the synthesis of methionine-containing recombinant elastin-like polypeptides (ELPs) of different lengths that contain periodically spaced methionine residues. These ELPs were chemoselectively alkylated at all methionine residues to give polycationic derivatives. Some of these samples were found to possess solubility transitions in water, where the temperature of these transitions varied with ELP concentration, nature of the methionine alkylating group, and nature of the sulfonium counterions. These studies show that introduction and controlled spacing of methionine sulfonium residues into ELPs can be used as a means both to tune their solubility transition temperatures in water using a variety of different parameters and to introduce new side-chain functionality.

Lysyl oxidase propeptide inhibits smooth muscle cell signaling and proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurtado, Paola A.; Vora, Siddharth; Sume, Siddika Selva

2008-02-01

Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression.more » In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-{alpha}-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology.« less

Low-Tech, Pilot Scale Purification of a Recombinant Spider Silk Protein Analog from Tobacco Leaves.

PubMed

Heppner, René; Weichert, Nicola; Schierhorn, Angelika; Conrad, Udo; Pietzsch, Markus

2016-10-09

Spider dragline is used by many members of the Araneae family not only as a proteinogenic safety thread but also for web construction. Spider dragline has been shown to possess high tensile strength in combination with elastic behavior. This high tensile strength can be attributed to the presence of antiparallel β-sheets within the thread; these antiparallel β-sheets are why the protein is classified as a silk. Due to the properties of spider silk and its technical and medical uses, including its use as a suture material and as a scaffold for tissue regeneration, spider dragline is a focus of the biotechnology industry. The production of sufficient amounts of spider silk is challenging, as it is difficult to produce large quantities of fibers because of the cannibalistic behavior of spiders and their large spatial requirements. In recent years, the heterologous expression of genes coding for spider silk analogs in various hosts, including plants such as Nicotiana tabacum , has been established. We developed a simple and scalable method for the purification of a recombinant spider silk protein elastin-like peptide fusion protein (Q-/K-MaSp1-100× ELP) after heterologous production in tobacco leaves involving heat and acetone precipitation. Further purification was performed using centrifugal Inverse Transition Cycling (cITC). Up to 400 mg of highly pure spider silk protein derivatives can be isolated from six kilograms of tobacco leaves, which is the highest amount of silk protein derivatives purified from plants thus far.

Resveratrol, 4′ Acetoxy Resveratrol, R-equol, Racemic Equol or S-equol as Cosmeceuticals to Improve Dermal Health

PubMed Central

Lephart, Edwin D.

2017-01-01

Phytochemicals are botanical compounds used in dermatology applications as cosmeceuticals to improve skin health. Resveratrol and equol are two of the best-known polyphenolic or phytoestrogens having similar chemical structures and some overlapping biological functions to 17β-estradiol. Human skin gene expression was reviewed for 28 different biomarkers when resveratrol, 4′ acetoxy resveratrol (4AR), R-equol, racemic equol or S-equol were tested. Sirtuin 1 activator (SIRT 1) was stimulated by resveratrol and 4AR only. Resveratrol, R-equol and racemic equol were effective on the aging biomarkers proliferating cell nuclear factor (PCNA), nerve growth factor (NGF), 5α-reductase and the calcium binding proteins S100 A8 and A9. Racemic equol and 4AR displayed among the highest levels for the collagens, elastin and tissue inhibitor of the matrix metalloproteinase 1 (TIMP 1). S-equol displayed the lowest level of effectiveness compared to the other compounds. The 4AR analog was more effective compared to resveratrol by 1.6-fold. R-equol and racemic equol were almost equal in potency displaying greater inhibition vs. resveratrol or its 4′ analog for the matrix metalloproteinases (MMPs), but among the inflammatory biomarkers, resveratrol, 4AR, R-equol and racemic equol displayed high inhibition. Thus, these cosmeceuticals display promise to improve dermal health; however, further study is warranted to understand how phytochemicals protect/enhance the skin. PMID:28587197

Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

PubMed

Cho, S; Dong, S; Parent, K N; Chen, M

2016-01-01

Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

Form and function of the bulbus arteriosus in yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus) and blue marlin (Makaira nigricans): static properties.

PubMed

Braun, Marvin H; Brill, Richard W; Gosline, John M; Jones, David R

2003-10-01

The juxtaposition of heart and gills in teleost fish means that the Windkessel function characteristic of the whole mammalian arterial tree has to be subserved by the extremely short ventral aorta and bulbus arteriosus. Over the functional pressure range, arteries from blue marlin (Makaira nigricans) and yellowfin tuna (Thunnus albacares) have J-shaped pressure-volume (P-V) loops, while bulbi from the same species have r-shaped P-V loops, with a steep initial rise followed by a compliant plateau phase. The steep initial rise in pressure is due to the geometry of the lumen. The interactions between radius, pressure and tension require a large initial pressure to open the bulbar lumen for flow. The plateau is due to the unique organization of the bulbar wall. The large elastin:collagen ratio, limited amount of collagen arranged circumferentially, lack of elastin lamellae and low hydrophobicity of the elastin itself all combine to lower stiffness, increase extensibility and allow efficient recoil. Even though the modulus of bulbus material is much lower than that of an artery, at large volumes the overall stiffness of the bulbus increases rapidly. The morphological features that give rise to the special inflation characteristics of the bulbus help to extend flow and maintain pressure during diastole.

Vitamin K deficiency: the linking pin between COPD and cardiovascular diseases?

PubMed

Piscaer, Ianthe; Wouters, Emiel F M; Vermeer, Cees; Janssens, Wim; Franssen, Frits M E; Janssen, Rob

2017-11-13

Cardiovascular diseases are prevalent in patients with chronic obstructive pulmonary disease (COPD). Their coexistence implies that many COPD patients require anticoagulation therapy. Although more and more replaced by direct oral anticoagulants, vitamin K antagonists (VKAs) are still widely used. VKAs induce profound deficiency of vitamin K, a key activator in the coagulation pathway. It is recognized however that vitamin K is also an essential cofactor in the activation of other extrahepatic proteins, such as matrix Gla protein (MGP), a potent inhibitor of arterial calcification. No or insufficient MGP activation by the use of VKAs is associated with a rapid progression of vascular calcification, which may enhance the risk for overt cardiovascular disease. Vitamin K consumption, on the other hand, seems to have a protective effect on the mineralization of arteries. Furthermore, vascular calcification mutually relates to elastin degradation, which is accelerated in patients with COPD associating with impaired survival. In this commentary, we hypothesize that vitamin K is a critical determinant to the rate of elastin degradation. We speculate on the potential link between poor vitamin K status and crucial mechanisms of COPD pathogenesis and raise concerns about the use of VKAs in patients with this disease. Future intervention studies are needed to explore if vitamin K supplementation is able to reduce elastin degradation and vascular calcification in COPD patients.

Diagnostic Exome Sequencing Identifies a Novel Gene, EMILIN1, Associated with Autosomal-Dominant Hereditary Connective Tissue Disease.

PubMed

Capuano, Alessandra; Bucciotti, Francesco; Farwell, Kelly D; Tippin Davis, Brigette; Mroske, Cameron; Hulick, Peter J; Weissman, Scott M; Gao, Qingshen; Spessotto, Paola; Colombatti, Alfonso; Doliana, Roberto

2016-01-01

Heritable connective tissue diseases are a highly heterogeneous family of over 200 disorders that affect the extracellular matrix. While the genetic basis of several disorders is established, the etiology has not been discovered for a large portion of patients, likely due to rare yet undiscovered disease genes. By performing trio-exome sequencing of a 55-year-old male proband presenting with multiple symptoms indicative of a connective disorder, we identified a heterozygous missense alteration in exon 1 of the Elastin Microfibril Interfacer 1 (EMILIN1) gene, c.64G>A (p.A22T). The proband presented with ascending and descending aortic aneurysms, bilateral lower leg and foot sensorimotor peripheral neuropathy, arthropathy, and increased skin elasticity. Sanger sequencing confirmed that the EMILIN1 alteration, which maps around the signal peptide cleavage site, segregated with disease in the affected proband, mother, and son. The impaired secretion of EMILIN-1 in cells transfected with the mutant p.A22T coincided with abnormal protein accumulation within the endoplasmic reticulum. In skin biopsy of the proband, we detected less EMILIN-1 with disorganized and abnormal coarse fibrils, aggregated deposits underneath the epidermis basal lamina, and dermal cells apoptosis. These findings collectively suggest that EMILIN1 may represent a new disease gene associated with an autosomal-dominant connective tissue disorder. © 2015 The Authors. **Human Mutation published by Wiley Periodicals, Inc.

Controlled Release from Recombinant Polymers

PubMed Central

Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

2014-01-01

Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

Biomechanical and morphological differences between the sclera canal ring and a peripheral sclera ring in the porcine eye.

PubMed

Terai, Naim; Schlötzer-Schrehardt, Ursula; Spoerl, Eberhard; Hornykewycz, Karin; Haentzschel, Janek; Haustein, Michael; Pillunat, Lutz E

2012-01-01

To investigate a possible association between the biomechanical load and unload behaviour and the elastin content of the sclera canal ring (SCR) and a superiorly localized sclera ring (SPS) in the porcine eye. Two sclera rings were trephined from each of 40 porcine eyes, one containing the SCR and the other an SPS. The load and the unload curves were measured in the extension range of 0-2.0 mm by a biomaterial tester. Hysteresis was determined from the area enclosed by the loading and unloading curve. Histochemical staining with resorcin-fuchsin and morphometric analysis of paraffin-embedded sections of both rings were performed to detect the area occupied by elastin fibres. At 1 mm extension, the mean load of the SCR was 0.89 ± 0.22 N and that of the SPS 1.13 ± 0.19 N, which was not significantly different between both rings (p > 0.05). Mean hysteresis in the SCR was 1.55 ± 0.30 N × mm and 1.90 ± 0.18 N × mm in the SPS, which was significantly different between both rings (p = 0.01). Mean sclera thickness was 986 μm in the SCR (range: 900-1,060 μm) and 971 μm in the SPS (range: 800-1,200 μm) without a statistically significant difference between both sclera rings (p = 0.78). The area occupied by elastin fibres was 15.5 ± 3.4% in the SCR and 4.5 ± 1.5% in the SPS, which was significantly different between both rings (p = 0.0001). Hysteresis in the SCR was significantly lower than in the SPS, indicating a higher elasticity of the SCR in the porcine eye. This effect could be explained by a higher content of elastin in the surrounding ring of the peripapillary optic nerve head providing reversible contraction in cases of intra-ocular pressure variations. Copyright © 2011 S. Karger AG, Basel.

Elastin-like-recombinamers multilayered nanofibrous scaffolds for cardiovascular applications.

PubMed

Putzu, M; Causa, F; Nele, V; de Torre, I González; Rodriguez-Cabello, J C; Netti, P A

2016-11-15

Coronary angioplasty is the most widely used technique for removing atherosclerotic plaques in blood vessels. The regeneration of the damaged intima layer after this treatment is still one of the major challenges in the field of cardiovascular tissue engineering. Different polymers have been used in scaffold manufacturing in order to improve tissue regeneration. Elastin-mimetic polymers are a new class of molecules that have been synthesized and used to obtain small diameter fibers with specific morphological characteristics. Elastin-like polymers produced by recombinant techniques and called elastin-like recombinamers (ELRs) are particularly promising due to their high degree of functionalization. Generally speaking, ELRs can show more complex molecular designs and a tighter control of their sequence than other chemically synthetized polymers Rodriguez Cabello et al (2009 Polymer 50 5159-69, 2011 Nanomedicine 6 111-22). For the fabrication of small diameter fibers, different ELRs were dissolved in 2,2,2-fluoroethanol (TFE). Dynamic light scattering was used to identify the transition temperature and get a deep characterization of the transition behavior of the recombinamers. In this work, we describe the use of electrospinning technique for the manufacturing of an elastic fibrous scaffold; the obtained fibers were characterized and their cytocompatibility was tested in vitro. A thorough study of the influence of voltage, flow rate and distance was carried out in order to determine the appropriate parameters to obtain fibrous mats without beads and defects. Moreover, using a rotating mandrel, we fabricated a tubular scaffold in which ELRs containing different cell adhesion sequences (mainly REDV and RGD) were collected. The stability of the scaffold was improved by using genipin as a crosslinking agent. Genipin-ELRs crosslinked scaffolds  show a good stability and fiber morphology. Human umbilical vein endothelial cells  were used to assess the in vitro bioactivity of the cell adhesion domains within the backbone of the ELRs.

Autosomal dominant inheritance of Williams-Beuren syndrome in a father and son with haploinsufficiency for FKBP6.

PubMed

Metcalfe, Kay; Simeonov, Emil; Beckett, William; Donnai, Dian; Tassabehji, May

2005-04-01

Williams-Beuren syndrome (WBS) is a neurodevelopmental microdeletion disorder that usually occurs sporadically due to its location within a highly repetitive genomic region that is unstable and prone to unequal cross-over during meiosis. The consequential loss of chromosomal material includes approximately 1.5 Mb of DNA at 7q11.23. Whilst cases of dominant inheritance have been described in the literature, there have been few reports of molecular confirmation and none have carried out detailed genotyping. We describe a Bulgarian father and son with WBS detected by fluorescent in situ hybridisation (with an elastin gene probe) and loss of heterozygosity mapping using microsatellite markers located in the critical region. These individuals appear to have a common WBS heterozygous deletion, confirming the expected dominant transmission and adding to the few familial cases reported. The deletion includes the gene FKBP6 which has recently been shown to play a role in homologous chromosome pairing in meiosis and male fertility in mouse models. Homozygous Fkbp6 -/- male mice are infertile and our data suggests that haploinsufficiency for FKBP6 does not appear to preclude male fertility in WBS, although male infertility involving this gene has the potential to follow the mouse model as a human autosomal recessive condition.

Matrix metalloproteinase interactions with collagen and elastin.

PubMed

Van Doren, Steven R

2015-01-01

Most abundant in the extracellular matrix are collagens, joined by elastin that confers elastic recoil to the lung, aorta, and skin. These fibrils are highly resistant to proteolysis but can succumb to a minority of the matrix metalloproteinases (MMPs). Considerable inroads to understanding how such MMPs move to the susceptible sites in collagen and then unwind the triple helix of collagen monomers have been gained. The essential role in unwinding of the hemopexin-like domain of interstitial collagenases or the collagen binding domain of gelatinases is highlighted. Elastolysis is also facilitated by the collagen binding domain in the cases of MMP-2 and MMP-9, and remote exosites of the catalytic domain in the case of MMP-12. Copyright © 2015. Published by Elsevier B.V.

Thermally targeted delivery of chemotherapeutics and anti-cancer peptides by elastin-like polypeptide.

PubMed

Raucher, Drazen; Massodi, Iqbal; Bidwell, Gene L

2008-03-01

Current chemotherapy treatment of solid tumors is limited due to a lack of specific delivery of the drugs to the tumor, leading to systemic toxicity. Therefore, it is necessary to develop targeted cancer therapies and tumor-targeted drug carriers. The authors review the development of elastin-like polypeptide (ELP) as a potential carrier for thermally targeted delivery of therapeutics. The authors searched Medline for articles concerning the application of ELP as a drug delivery vector for small molecule drugs and therapeutic peptides. ELP has been demonstrated to be a promising thermally targeted carrier. Further examination of the in vivo biodistribution and efficacy will provide the necessary data to advance ELP technology toward the ultimate goal of human therapeutics.

Engineering poly(hydroxy butyrate-co-hydroxy valerate) based vascular scaffolds to mimic native artery.

PubMed

Deepthi, S; Nivedhitha Sundaram, M; Vijayan, Ponni; Nair, Shantikumar V; Jayakumar, R

2018-04-01

Electrospun tri-layered fibrous scaffold incorporating VEGF and Platelet Factor Concentrate (PFC) in multiple layers having different layer architectures was designed to mimic native artery. The scaffold consisted of longitudinally aligned poly(hydroxy butyrate-co-hydroxy valerate) (PHBV) and poly(vinyl alcohol) (PVA) nanofibers (inner layer), radially aligned PHBV-elastin nanofibers (middle layer) to provide the bi-directional alignment and combination of longitudinally aligned PHBV-elastin and random PHBV/PVA multiscale fibers (peripheral layer). Tubular constructs of diameter <6 mm were developed. The developed electrospun fibers were characterised by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy and Tensile tests. Further the burst strength, compliance and stiffness index of tri-layered tubular scaffold was evaluated. SEM images of fibrous layers showed the typical longitudinal and radial alignment of fibers in the tubular construct. SEM images showed that the prepared PHBV nanofibers were in the range of 500-800 nm and PHBV microfibers were of 1-2 μm in diameter in the tri-layered electrospun membrane. PVA nanofibers were of size 200-250 nm. The tensile strength, percentage compliance and stiffness index of tri-layered membrane was in accordance with that of native small blood vessels. The developed tri-layered membrane was blood compatible, with hemolysis degree 0.85 ± 0.21% and did not activate platelets. Controlled release of VEGF and PFC was observed from the scaffold. The biocompatibility of the tri-layered scaffold was evaluated using HUVECs, SMCs and MSCs and SMCs infiltration from the outer layer was also evaluated. Specific protein expression for the HUVECs and SMCs was evaluated by flow cytometry and immunocytochemistry. HUVECs and SMCs exhibited good elongation and alignment along the direction of fibers and was found to maintain its CD31, VE-Cadherin and αSMA expression respectively. The results highlight the importance of bi-directional fiber alignment on the tri-layered electrospun scaffold as a suitable architectural prototype for vascular scaffolds to mimic the native arteries. Copyright © 2017 Elsevier B.V. All rights reserved.

Diphlorethohydroxycarmalol of Ishige okamurae and Caffeine Modified the Expression of Extracellular Fibrillars during Adipogenesis of Mouse Subcutaneous Adipose Derived Stem Cell

PubMed Central

Jeon, Younmi; Song, Siyoung; Kim, Hagju; Cheon, Yong-Pil

2013-01-01

Although, one of the etiologies of localized lipodystrophy of the subcutaneous connective tissue (cellulite) is the histological alternation of adipose tissue, the characteristics of expression of the components of extracellular matrix (ECM) components during adipogenesis are not uncovered. In this study, the effects of caffeine and Ishige okamurae originated diphlorethohydroxycarmalol (DPHC) on the expression of extracellualr fibers was analyzed with quantitative RT-PCR during differentiation induction of mouse subcutaneous adipose derived stem cells (msADSC) into adipocyte. The expression levels of Col1a, Col3a1, and Col61a were decreased by the adipogenci induction in a time-dependent manners. However, Col2a mRNA and Col4a1 mRNA expressions were oposit to them. Caffeine and DPHC stimulated the changes of the expression of these collagens. Eln mRNA expression was increased by induction. DPHC stimulated the expression of it. Mfap5 mRNA expression was deceased in both adipogenic cell and matured adipocytes. Caffeine suppressed the expression of Mfap5 but the effect of DPHC was different by the concentration. The expression of bioglycan, decorin, and lumican were also modified by caffeine and DPHC in a concentration-dependent manner. Based on this study, we revealed firstly the effects of caffeine and DPHC on the expression of collagens, elastin, and glycoproteins during adipogenesis of msADSCs. Those results suggest that DPHC may have antiadipogenic effect and has more positive effets on normal adipose tissue generation and work as suppressor the abnormality of ECM structure. Such results indicate that DPHC can be applied in keeping the stability of the ECM of adipogenic tissues. PMID:25949143

Silk-based biomaterials functionalized with fibronectin type II promotes cell adhesion.

PubMed

Pereira, Ana Margarida; Machado, Raul; da Costa, André; Ribeiro, Artur; Collins, Tony; Gomes, Andreia C; Leonor, Isabel B; Kaplan, David L; Reis, Rui L; Casal, Margarida

2017-01-01

The objective of this work was to exploit the fibronectin type II (FNII) module from human matrix metalloproteinase-2 as a functional domain for the development of silk-based biopolymer blends that display enhanced cell adhesion properties. The DNA sequence of spider dragline silk protein (6mer) was genetically fused with the FNII coding sequence and expressed in Escherichia coli. The chimeric protein 6mer+FNII was purified by non-chromatographic methods. Films prepared from 6mer+FNII by solvent casting promoted only limited cell adhesion of human skin fibroblasts. However, the performance of the material in terms of cell adhesion was significantly improved when 6mer+FNII was combined with a silk-elastin-like protein in a concentration-dependent behavior. With this work we describe a novel class of biopolymer that promote cell adhesion and potentially useful as biomaterials for tissue engineering and regenerative medicine. This work reports the development of biocompatible silk-based composites with enhanced cell adhesion properties suitable for biomedical applications in regenerative medicine. The biocomposites were produced by combining a genetically engineered silk-elastin-like protein with a genetically engineered spider-silk-based polypeptide carrying the three domains of the fibronectin type II module from human metalloproteinase-2. These composites were processed into free-standing films by solvent casting and characterized for their biological behavior. To our knowledge this is the first report of the exploitation of all three FNII domains as a functional domain for the development of bioinspired materials with improved biological performance. The present study highlights the potential of using genetically engineered protein-based composites as a platform for the development of new bioinspired biomaterials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Matrix-directed differentiation of human adipose-derived mesenchymal stem cells to dermal-like fibroblasts that produce extracellular matrix.

PubMed

Sivan, Unnikrishnan; Jayakumar, K; Krishnan, Lissy K

2016-10-01

Commercially available skin substitutes lack essential non-immune cells for adequate tissue regeneration of non-healing wounds. A tissue-engineered, patient-specific, dermal substitute could be an attractive option for regenerating chronic wounds, for which adipose-derived mesenchymal stem cells (ADMSCs) could become an autologous source. However, ADMSCs are multipotent in nature and may differentiate into adipocytes, osteocytes and chondrocytes in vitro, and may develop into undesirable tissues upon transplantation. Therefore, ADMSCs committed to the fibroblast lineage could be a better option for in vitro or in vivo skin tissue engineering. The objective of this study was to standardize in vitro culture conditions for ADMSCs differentiation into dermal-like fibroblasts which can synthesize extracellular matrix (ECM) proteins. Biomimetic matrix composite, deposited on tissue culture polystyrene (TCPS), and differentiation medium (DM), supplemented with fibroblast-conditioned medium and growth factors, were used as a fibroblast-specific niche (FSN) for cell culture. For controls, ADMSCs were cultured on bare TCPS with either DM or basal medium (BM). Culture of ADMSCs on FSN upregulated the expression of differentiation markers such as fibroblast-specific protein-1 (FSP-1) and a panel of ECM molecules specific to the dermis, such as fibrillin-1, collagen I, collagen IV and elastin. Immunostaining showed the deposition of dermal-specific ECM, which was significantly higher in FSN compared to control. Fibroblasts derived from ADMSCs can synthesize elastin, which is an added advantage for successful skin tissue engineering as compared to fibroblasts from skin biopsy. To obtain rapid differentiation of ADMSCs to dermal-like fibroblasts for regenerative medicine, a matrix-directed differentiation strategy may be employed. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Antioxidant Vitamin C attenuates experimental abdominal aortic aneurysm development in an elastase-induced rat model.

PubMed

Shang, Tao; Liu, Zhao; Liu, Chang-jian

2014-05-01

We investigated the hypothesis that an antioxidant, Vitamin C, could attenuate abdominal aortic aneurysm (AAA) development in a rat model. An AAA model induced by intraluminal infusion was created in 36 male Sprague Dawley rats, which were randomly distributed into three groups: Sham (saline infused, placebo treated), Control (elastase infused, placebo treated), and Vitamin C (elastase infused, vitamin C treated). Vitamin C and placebo were intraperitoneally injected, initiating 1 wk before the infusion and continuing throughout the study. The aortic dilatation ratio was measured, and aortic tissues were further examined using biochemical and histologic techniques. Vitamin C attenuated the development of AAA, decreasing maximal aortic diameter by 25.8% (P < 0.05) and preserving elastin lamellae (P < 0.05). Vitamin C also decreased 8-hydroxyguanine (a marker of oxidative damage to DNA) and 8-isoprostane content (a marker of oxidative stress) in aortic tissues (P < 0.05, respectively). The proteins of matrix metalloproteinase (MMP)-2, MMP-9, and interleukin 6 were markedly downregulated (P < 0.05, respectively), accompanied with notably reduced messenger RNA expression of tumor necrosis factor-α, MMP-2/9, and interleukin 1β (P < 0.05, respectively). However, messenger RNA of tissue inhibitors of metalloproteinase-1 and tissue inhibitors of metalloproteinase-2 were both significantly upregulated in Vitamin C group. Vitamin C treatment had no significant effect on systolic blood pressure (P > 0.05). Vitamin C attenuated AAA development in an elastase-induced rat model via crucial protective effect, which was mediated by an increased level of antioxidant in cooperation with preserving elastin lamellae, inhibiting matrix-degrading proteinases and suppressing inflammatory responses. Copyright © 2014. Published by Elsevier Inc.

Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid)

NASA Astrophysics Data System (ADS)

Kakinoki, Sachiro; Nakayama, Midori; Moritan, Toshiyuki; Yamaoka, Tetsuji

2014-07-01

We developed a microfibrous poly(L-lactic acid) (PLLA) nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG)30) that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol) was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG)30 composisting of an elastin-like repetitive sequence (VPGIG)30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73) was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG)30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG)30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG)30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG)30 inner layer.

In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

PubMed

Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

2017-06-01

Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly) n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746-1755, 2017. © 2017 Wiley Periodicals, Inc.

Contribution of collagen and elastin fibers to the mechanical behavior of an abdominal connective tissue.

PubMed

Levillain, A; Orhant, M; Turquier, F; Hoc, T

2016-08-01

The linea alba is a complex structure commonly involved in hernia formation. Knowledge of its mechanical behavior is essential to design suitable meshes and reduce the risk of recurrence. The aim of this study was to investigate the relationships between the mechanical properties of the linea alba and the organization of collagen and elastin fibers. For that purpose, longitudinal and transversal samples were removed from four porcine and three human linea alba, to perform tensile tests under a biphotonic confocal microscope, in each direction. Microscopic observation revealed a tissue composed of two layers, made of transversal collagen fibers in the dorsal side and oblique collagen fibers in the ventral side. This particular architecture led to an anisotropic mechanical behavior, with higher stress in the transversal direction. During loading, oblique fibers of the ventral layer reoriented toward the tensile axis in both directions, while fibers of the dorsal layer remained in the transversal direction. This rotation of oblique fibers progressively increased the stiffness of the tissue and induced a non-linear stress-stretch relation. Elastin fibers formed a layer covering the collagen fibers and followed their movement, suggesting that they ensure their elastic recoil. All of these results demonstrated the strong relationships between the microstructure and the mechanical behavior of the linea alba. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential Stiffening between the Abdominal and Thoracic Aorta: Effect of Salt Loading in Stroke-Prone Hypertensive Rats.

PubMed

Lindesay, George; Bézie, Yvonnick; Ragonnet, Christophe; Duchatelle, Véronique; Dharmasena, Chandima; Villeneuve, Nicole; Vayssettes-Courchay, Christine

2018-06-08

Central artery stiffening is recognized as a cardiovascular risk. The effects of hypertension and aging have been shown in human and animal models but the effect of salt is still controversial. We studied the effect of a high-salt diet on aortic stiffness in salt-sensitive spontaneously hypersensitive stroke-prone rats (SHRSP). Distensibility, distension, and β-stiffness were measured at thoracic and abdominal aortic sites in the same rats, using echotracking recording of the aortic diameter coupled with blood pressure (BP), in SHRSP-salt (5% salted diet, 5 weeks), SHRSP, and normotensive Wistar-Kyoto (WKY) rats. Hemodynamic parameters were measured at BP matched to that of WKY. Histological staining and immunohistochemistry were used for structural analysis. Hemodynamic isobaric parameters in SHRSP did not differ from WKY and only those from the abdominal aorta of SHRSP-salt presented decreased distensibility and increased stiffness compared with WKY and SHRSP. The abdominal and thoracic aortas presented similar thickening, increased fibrosis, and remodeling with no change in collagen content. SHRSP-salt presented a specific increased elastin disarray at the abdominal aorta level but a decrease in elastin content in the thoracic aorta. This study demonstrates the pro-stiffening effect of salt in addition to hypertension; it shows that only the abdominal aorta presents a specific pressure-independent stiffening, in which elastin disarray is likely a key mechanism. © 2018 S. Karger AG, Basel.

In vitro characterization of a collagen scaffold enzymatically cross-linked with a tailored elastin-like polymer.

PubMed

Garcia, Yolanda; Hemantkumar, Naik; Collighan, Russell; Griffin, Martin; Rodriguez-Cabello, Jose Carlos; Pandit, Abhay

2009-04-01

Collagen, the main structural component of the extracellular matrix (ECM), provides tensile stiffness to different structures and organs against rupture. However, collagen tissue-engineered implants are hereto still lacking in mechanical strength. Attempts to create stiffer scaffolds have resulted in increased brittleness of the material, reducing the versatility of the original component. The hypothesis behind this research is that the introduction of an elastic element in the scaffold will enhance the mechanical properties of the collagen-based scaffolds, as elastin does in the ECM to prevent irreversible deformation. In this study, an elastin-like polymer (ELP) designed and synthesized using recombinant DNA methodology is used with the view to providing increased proteolytic resistance and increased functionality to the scaffolds by carrying specific sequences for microbial transglutaminase cross-linking, endothelial cell adhesion, and drug delivery. Evaluation of the effects that cross-linking ELP-collagen has on the physicochemical properties of the scaffold such as porosity, presence of cross-linking, thermal behavior, and mechanical strength demonstrated that the introduction of enzymatically resistant covalent bonds between collagen and ELP increases the mechanical strength of the scaffolds in a dose-dependent manner without significantly affecting the porosity or thermal properties of the original scaffold. Importantly, the scaffolds also showed selective behavior, in a dose (ELP)-dependent manner toward human umbilical vein endothelial cells and smooth muscle cells when compared to fibroblasts.

Designing Protein-Based Biomaterials for Medical Applications

PubMed Central

Gagner, Jennifer E.; Kim, Wookhyun; Chaikof, Elliot L.

2013-01-01

Biomaterials produced by nature have been honed through billions of years, evolving exquisitely precise structure-function relationships that scientists strive to emulate. Advances in genetic engineering have facilitated extensive investigations to determine how changes in even a single peptide within a protein sequence can produce biomaterials with unique thermal, mechanical and biological properties. Elastin, a naturally occurring protein polymer, serves as a model protein to determine the relationship between specific structural elements and desirable material characteristics. The modular, repetitive nature of the protein facilitates the formation of well-defined secondary structures with the ability to self-assemble into complex three-dimensional architectures on a variety of length scales. Furthermore, many opportunities exist to incorporate other protein-based motifs and inorganic materials into recombinant protein-based materials, extending the range and usefulness of these materials in potential biomedical applications. Elastin-like polypeptides can be assembled into 3D architectures with precise control over payload encapsulation, mechanical and thermal properties, as well as unique functionalization opportunities through both genetic and enzymatic means. An overview of current protein-based materials, their properties and uses in biomedicine will be provided, with a focus on the advantages of elastin-like polypeptides. Applications of these biomaterials as imaging and therapeutic delivery agents will be discussed. Finally, broader implications and future directions of these materials as diagnostic and therapeutic systems will be explored. PMID:24121196

Histopathological analysis of cellular localization of cathepsins in abdominal aortic aneurysm wall.

PubMed

Lohoefer, Fabian; Reeps, Christian; Lipp, Christina; Rudelius, Martina; Zimmermann, Alexander; Ockert, Stefan; Eckstein, Hans-Henning; Pelisek, Jaroslav

2012-08-01

An important feature of abdominal aortic aneurysm (AAA) is the destruction of vessel wall, especially elastin and collagen. Besides matrix metalloproteinases, cathepsins are the most potent elastolytic enzymes. The expression of cathepsins with known elastolytic and collagenolytic activities in the individual cells within AAA has not yet been determined. The vessel wall of 32 AAA patients and 10 organ donors was analysed by immunohistochemistry for expression of cathepsins B, D, K, L and S, and cystatin C in all cells localized within AAA. Luminal endothelial cells (ECs) of AAA were positive for cathepsin D and partially for cathepsins B, K and S. Endothelial cells of the neovessels and smooth muscle cells in the media were positive for all cathepsins tested, especially for cathepsin B. In the inflammatory infiltrate all cathepsins were expressed in the following pattern: B > D = S > K = L. Macrophages showed the highest staining intensity for all cathepsins. Furthermore, weak overall expression of cystatin C was observed in all the cells localized in the AAA with the exception of the ECs. There is markedly increased expression of the various cathepsins within the AAA wall compared to healthy aorta. Our data are broadly consistent with a role for cathepsins in AAA; and demonstrate expression of cathepsins D, B and S in phagocytic cells in the inflammatory infiltrate; and also may reveal a role for cathepsin B in lymphocytes. © 2012 The Authors. International Journal of Experimental Pathology © 2012 International Journal of Experimental Pathology.

Cardiac arrest related to anaesthesia in Williams-Beuren syndrome.

PubMed

Lucena Delgado, J; Sanabria Carretero, P; Durán la Fuente, P; Gónzalez Rocafort, A; Castro Parga, L; Reinoso Barbero, F

2018-04-01

Williams-Beuren syndrome is the clinical manifestation of a congenital genetic disorder in the elastin gene, among others. There is a history of cardiac arrest refractory to resuscitation manoeuvres in anaesthesia. The incidence of myocardial ischaemia is high during anaesthetic induction, but there are patients who do not have this condition yet also have had very serious cardiac events, and issues that are still to be resolved. Case descriptions will enable the common pathophysiological factors to be defined, and decrease morbidity and mortality. We report the case of a 3-year-old boy with cardiac arrest at induction, rescued with circulatory assistance with extracorporeal membrane oxygenation and hypothermia induced for cerebral protection. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Your Skin

MedlinePlus

... contains nerve endings, blood vessels, oil glands, and sweat glands. It also contains collagen and elastin, which ... absorb water and get soggy. You also have sweat glands on your epidermis. Even though you can' ...

Exploring the Properties of Genetically Engineered Silk-Elastin-Like Protein Films.

PubMed

Machado, Raul; da Costa, André; Sencadas, Vitor; Pereira, Ana Margarida; Collins, Tony; Rodríguez-Cabello, José Carlos; Lanceros-Méndez, Senentxu; Casal, Margarida

2015-12-01

Free standing films of a genetically engineered silk-elastin-like protein (SELP) were prepared using water and formic acid as solvents. Exposure to methanol-saturated air promoted the formation of aggregated β-strands rendering aqueous insolubility and improved the mechanical properties leading to a 10-fold increase in strain-to-failure. The films were optically clear with resistivity values similar to natural rubber and thermally stable up to 180 °C. Addition of glycerol showed to enhance the flexibility of SELP/glycerol films by interacting with SELP molecules through hydrogen bonding, interpenetrating between the polymer chains and granting more conformational freedom. This detailed characterization provides cues for future and unique applications using SELP based biopolymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elastin and collagen fibre microstructure of the human aorta in ageing and disease: a review

PubMed Central

Tsamis, Alkiviadis; Krawiec, Jeffrey T.; Vorp, David A.

2013-01-01

Aortic disease is a significant cause of death in developed countries. The most common forms of aortic disease are aneurysm, dissection, atherosclerotic occlusion and ageing-induced stiffening. The microstructure of the aortic tissue has been studied with great interest, because alteration of the quantity and/or architecture of the connective fibres (elastin and collagen) within the aortic wall, which directly imparts elasticity and strength, can lead to the mechanical and functional changes associated with these conditions. This review article summarizes the state of the art with respect to characterization of connective fibre microstructure in the wall of the human aorta in ageing and disease, with emphasis on the ascending thoracic aorta and abdominal aorta where the most common forms of aortic disease tend to occur. PMID:23536538

Photoinduced Thiol-ene Chemistry Applied to the Synthesis of Self-Assembling Elastin-Inspired Glycopeptides.

PubMed

Piccirillo, Germano; Pepe, Antonietta; Bedini, Emiliano; Bochicchio, Brigida

2017-02-21

Synthetic (glyco)peptides inspired by proteins able to self-assemble are appealing biomaterials in the field of tissue engineering and regenerative medicine. Herein, for the first time, taking advantage of thiol-ene chemistry coupled to solid-phase peptide synthesis, a self-assembling peptide inspired by elastin protein was bioconjugated to three carbohydrates in order to obtain the corresponding glycopeptides. They were studied at the molecular and supramolecular level. The results show that the carbohydrate influences the molecular conformation of the glycopeptide and its self-aggregation properties as well. As future perspective, the results could enable us to tune the final self-aggregation properties of the glycopeptide by changing the sugar moiety. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective Tuning of Elastin-like Polypeptide Properties via Methionine Oxidation.

PubMed

Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Dieryck, Wilfrid; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

2017-02-13

We have designed and prepared a recombinant elastin-like polypeptide (ELP) containing precisely positioned methionine residues, and performed the selective and complete oxidation of its methionine thioether groups to both sulfoxide and sulfone derivatives. Since these oxidation reactions substantially increase methionine residue polarity, they were found to be a useful means to precisely adjust the temperature responsive behavior of ELPs in aqueous solutions. In particular, lower critical solution temperatures were found to be elevated in oxidized sample solutions, but were not eliminated. These transition temperatures were found to be further tunable by the use of solvents containing different Hofmeister salts. Overall, the ability to selectively and fully oxidize methionine residues in ELPs proved to be a convenient postmodification strategy for tuning their transition temperatures in aqueous media.

Modulating the Behaviors of Mesenchymal Stem Cells Via the Combination of High-Frequency Vibratory Stimulations and Fibrous Scaffolds

PubMed Central

Tong, Zhixiang; Duncan, Randall L.

2013-01-01

We are interested in the in vitro engineering of artificial vocal fold tissues via the strategic combination of multipotent mesenchymal stem cells (MSCs), physiologically relevant mechanical stimulations, and biomimetic artificial matrices. We have constructed a vocal fold bioreactor that is capable of imposing vibratory stimulations on the cultured cells at human phonation frequencies. Separately, fibrous poly (ɛ-caprolactone) (PCL) scaffolds emulating the ligamentous structure of the vocal fold were prepared by electrospinning, were incorporated in the vocal fold bioreactor, and were driven into a wave-like motion in an axisymmetrical fashion by the oscillating air. MSC-laden PCL scaffolds were subjected to vibrations at 200 Hz with a normal center displacement of ∼40 μm for a total of 7 days. A continuous (CT) or a 1 h-on-1 h-off (OF) regime with a total dynamic culture time of 12 h per day was applied. The dynamic loading did not cause any physiological trauma to the cells. Immunohistotochemical staining revealed the reinforcement of the actin filament and the enhancement of α5β1 integrin expression under selected dynamic culture conditions. Cellular expression of essential vocal fold extracellular matrix components, such as elastin, hyaluronic acid, and matrix metalloproteinase-1, was significantly elevated as compared with the static controls, and the OF regime is more conducive to matrix production than the CT vibration mode. Analyses of genes of typical fibroblast hallmarks (tenascin-C, collagen III, and procollagen I) as well as markers for MSC differentiation into nonfibroblastic lineages confirmed MSCs' adaptation of fibroblastic behaviors. Overall, the high-frequency vibratory stimulation, when combined with a synthetic fibrous scaffold, serves as a potent modulator of MSC functions. The novel bioreactor system presented here, as a versatile, yet well-controlled model, offers an in vitro platform for understanding vibration-induced mechanotransduction and for engineering of functional vocal fold tissues. PMID:23516973

mPGES-1 (Microsomal Prostaglandin E Synthase-1) Mediates Vascular Dysfunction in Hypertension Through Oxidative Stress.

PubMed

Avendaño, María S; García-Redondo, Ana B; Zalba, Guillermo; González-Amor, María; Aguado, Andrea; Martínez-Revelles, Sonia; Beltrán, Luis M; Camacho, Mercedes; Cachofeiro, Victoria; Alonso, María J; Salaices, Mercedes; Briones, Ana M

2018-06-11

mPGES-1 (microsomal prostaglandin E synthase-1), the downstream enzyme responsible for PGE 2 (prostaglandin E 2 ) synthesis in inflammatory conditions and oxidative stress are increased in vessels from hypertensive animals. We evaluated the role of mPGES-1-derived PGE 2 in the vascular dysfunction and remodeling in hypertension and the possible contribution of oxidative stress. We used human peripheral blood mononuclear cells from asymptomatic patients, arteries from untreated and Ang II (angiotensin II)-infused mPGES-1 -/- and mPGES-1 +/+ mice, and vascular smooth muscle cells exposed to PGE 2 In human cells, we found a positive correlation between mPGES-1 mRNA and carotid intima-media thickness ( r =0.637; P <0.001) and with NADPH oxidase-dependent superoxide production ( r =0.417; P <0.001). In Ang II-infused mice, mPGES-1 deletion prevented all of the following: (1) the augmented wall:lumen ratio, vascular stiffness, and altered elastin structure; (2) the increased gene expression of profibrotic and proinflammatory markers; (3) the increased vasoconstrictor responses and endothelial dysfunction; (4) the increased NADPH oxidase activity and the diminished mitochondrial membrane potential; and (5) the increased reactive oxygen species generation and reduced NO bioavailability. In vascular smooth muscle cells or aortic segments, PGE 2 increased NADPH oxidase expression and activity and reduced mitochondrial membrane potential, effects that were abolished by antagonists of the PGE 2 receptors (EP), EP1 and EP3, and by JNK (c-Jun N-terminal kinase) and ERK1/2 (extracellular-signal-regulated kinases 1/2) inhibition. Deletion of mPGES-1 augmented vascular production of PGI 2 suggesting rediversion of the accumulated PGH 2 substrate. In conclusion, mPGES-1-derived PGE 2 is involved in vascular remodeling, stiffness, and endothelial dysfunction in hypertension likely through an increase of oxidative stress produced by NADPH oxidase and mitochondria. © 2018 American Heart Association, Inc.

Preliminary results in single-step wound closure procedure of full-thickness facial burns in children by using the collagen-elastin matrix and review of pediatric facial burns.

PubMed

Demircan, Mehmet; Cicek, Tugrul; Yetis, Muhammed Ikbal

2015-09-01

Management of full-thickness facial burns remains one of the greatest challenges. Controversy exists among surgeons regarding the use of early excision for facial burns. Unfortunately, delayed excision of deeper burns often results in more scarring and subsequent reconstruction becomes more difficult. A collagen-elastin matrix is used to improve the quality of the reconstructed skin, to reduce scarring and to prevent wound contraction. It serves as a foundation for split thickness skin graft and enhances short and long-term results. We report the usage of a collagen-elastin matrix during single-step wound closure technique of severe full-thickness facial burns in 15 children with large burned body surface area, and also we review the literature about pediatric facial burns. There were 15 pediatric patients with severe facial burns, 8 girls and 7 boys ranging in age from 10 months to 12 years, mean age 7 years and 6 months old. The facial burn surface area (FBSA) among the patients includes seven patients with 100%, five with 75%, and three with 50%. The average total body surface area (TBSA) for the patients was 72%, ranging between 50 and 90%. 5 of the patients' admissions were late, more than four days after burns while the rest of the patients were admitted within the first four days (acute admission time). The burns were caused by flame in eight of the patients, bomb blast in four, and scalding in three. All patients were treated by the simultaneous application of the collagen-elastin matrix and an unmeshed split thickness skin graft at Turgut Özal Medical Center, Pediatric Burn Center, Malatya, Turkey. After the treatment only two patients needed a second operation for revision of the grafts. All grafts transplanted to the face survived. The average Vancouver scar scales (VSS) were 2.55±1.42, ranging between one and six, in the first 10 of 15 patients at the end of 6 months postoperatively. VSS measurements of the last 5 patients were not taken since the 6 months postoperative period was not over. In regard to early results, graft quality was close to normal skin in terms of vascularity, elasticity, pliability, texture and color. Esthetic and functional results have been encouraging. This study shows us that the collagen-elastin matrix as a dermal substitute is a useful adjunct, which may result in quick healing with satisfying esthetic and functional results. It also may enhance short and long-term results in after burn facial wound closure in children. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Hemizygosity at the NCF1 Gene in Patients with Williams-Beuren Syndrome Decreases Their Risk of Hypertension

PubMed Central

Del Campo, Miguel; Antonell, Anna; Magano, Luis F.; Muñoz, Francisco J.; Flores, Raquel; Bayés, Mònica; Pérez Jurado, Luis A.

2006-01-01

Williams-Beuren syndrome (WBS), caused by a heterozygous deletion at 7q11.23, represents a model for studying hypertension, the leading risk factor for mortality worldwide, in a genetically determined disorder. Haploinsufficiency at the elastin gene is known to lead to the vascular stenoses in WBS and is also thought to predispose to hypertension, present in ∼50% of patients. Detailed clinical and molecular characterization of 96 patients with WBS was performed to explore clinical-molecular correlations. Deletion breakpoints were precisely defined and were found to result in variability at two genes, NCF1 and GTF2IRD2. Hypertension was significantly less prevalent in patients with WBS who had the deletion that included NCF1 (P=.02), a gene coding for the p47phox subunit of the NADPH oxidase. Decreased p47phox protein levels, decreased superoxide anion production, and lower protein nitrotyrosination were all observed in cell lines from patients hemizygous at NCF1. Our results indicate that the loss of a functional copy of NCF1 protects a proportion of patients with WBS against hypertension, likely through a lifelong reduced angiotensin II–mediated oxidative stress. Therefore, antioxidant therapy that reduces NADPH oxidase activity might have a potential benefit in identifiable patients with WBS in whom serious complications related to hypertension have been reported, as well as in forms of essential hypertension mediated by a similar pathogenic mechanism. PMID:16532385

Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

PubMed

Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart; Heusinkveld, Maarten H G; Thorsted, Bjarne; Rosenstand, Kristoffer; Nissen, Inger; Hansen, Ulla M; Brewer, Jonathan R; Bagatolli, Luis A; Rasmussen, Lars M; Irmukhamedov, Akhmadjon; Reesink, Koen D; De Mey, Jo G R

2017-07-01

The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R 2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies. NEW & NOTEWORTHY This is the first study to quantitatively relate pressure-induced microstructural changes in resistance arteries to the mechanics of their wall. Principal findings using a pig model system were confirmed in human arteries. The combined methods provide a strong tool for future hypothesis-driven studies of microvascular pathologies. Copyright © 2017 the American Physiological Society.

Production and Assessment of Decellularized Pig and Human Lung Scaffolds

PubMed Central

Niles, Jean; Riddle, Michael; Vargas, Gracie; Schilagard, Tuya; Ma, Liang; Edward, Kert; La Francesca, Saverio; Sakamoto, Jason; Vega, Stephanie; Ogadegbe, Marie; Mlcak, Ronald; Deyo, Donald; Woodson, Lee; McQuitty, Christopher; Lick, Scott; Beckles, Daniel; Melo, Esther; Cortiella, Joaquin

2013-01-01

The authors have previously shown that acellular (AC) trachea-lung scaffolds can (1) be produced from natural rat lungs, (2) retain critical components of the extracellular matrix (ECM) such as collagen-1 and elastin, and (3) be used to produce lung tissue after recellularization with murine embryonic stem cells. The aim of this study was to produce large (porcine or human) AC lung scaffolds to determine the feasibility of producing scaffolds with potential clinical applicability. We report here the first attempt to produce AC pig or human trachea-lung scaffold. Using a combination of freezing and sodium dodecyl sulfate washes, pig trachea-lungs and human trachea-lungs were decellularized. Once decellularization was complete we evaluated the structural integrity of the AC lung scaffolds using bronchoscopy, multiphoton microscopy (MPM), assessment of the ECM utilizing immunocytochemistry and evaluation of mechanics through the use of pulmonary function tests (PFTs). Immunocytochemistry indicated that there was loss of collagen type IV and laminin in the AC lung scaffold, but retention of collagen-1, elastin, and fibronectin in some regions. MPM scoring was also used to examine the AC lung scaffold ECM structure and to evaluate the amount of collagen I in normal and AC lung. MPM was used to examine the physical arrangement of collagen-1 and elastin in the pleura, distal lung, lung borders, and trachea or bronchi. MPM and bronchoscopy of trachea and lung tissues showed that no cells or cell debris remained in the AC scaffolds. PFT measurements of the trachea-lungs showed no relevant differences in peak pressure, dynamic or static compliance, and a nonrestricted flow pattern in AC compared to normal lungs. Although there were changes in content of collagen I and elastin this did not affect the mechanics of lung function as evidenced by normal PFT values. When repopulated with a variety of stem or adult cells including human adult primary alveolar epithelial type II cells both pig and human AC scaffolds supported cell attachment and cell viability. Examination of scaffolds produced using a variety of detergents indicated that detergent choice influenced human immune response in terms of T cell activation and chemokine production. PMID:23638920

Production and assessment of decellularized pig and human lung scaffolds.

PubMed

Nichols, Joan E; Niles, Jean; Riddle, Michael; Vargas, Gracie; Schilagard, Tuya; Ma, Liang; Edward, Kert; La Francesca, Saverio; Sakamoto, Jason; Vega, Stephanie; Ogadegbe, Marie; Mlcak, Ronald; Deyo, Donald; Woodson, Lee; McQuitty, Christopher; Lick, Scott; Beckles, Daniel; Melo, Esther; Cortiella, Joaquin

2013-09-01

The authors have previously shown that acellular (AC) trachea-lung scaffolds can (1) be produced from natural rat lungs, (2) retain critical components of the extracellular matrix (ECM) such as collagen-1 and elastin, and (3) be used to produce lung tissue after recellularization with murine embryonic stem cells. The aim of this study was to produce large (porcine or human) AC lung scaffolds to determine the feasibility of producing scaffolds with potential clinical applicability. We report here the first attempt to produce AC pig or human trachea-lung scaffold. Using a combination of freezing and sodium dodecyl sulfate washes, pig trachea-lungs and human trachea-lungs were decellularized. Once decellularization was complete we evaluated the structural integrity of the AC lung scaffolds using bronchoscopy, multiphoton microscopy (MPM), assessment of the ECM utilizing immunocytochemistry and evaluation of mechanics through the use of pulmonary function tests (PFTs). Immunocytochemistry indicated that there was loss of collagen type IV and laminin in the AC lung scaffold, but retention of collagen-1, elastin, and fibronectin in some regions. MPM scoring was also used to examine the AC lung scaffold ECM structure and to evaluate the amount of collagen I in normal and AC lung. MPM was used to examine the physical arrangement of collagen-1 and elastin in the pleura, distal lung, lung borders, and trachea or bronchi. MPM and bronchoscopy of trachea and lung tissues showed that no cells or cell debris remained in the AC scaffolds. PFT measurements of the trachea-lungs showed no relevant differences in peak pressure, dynamic or static compliance, and a nonrestricted flow pattern in AC compared to normal lungs. Although there were changes in content of collagen I and elastin this did not affect the mechanics of lung function as evidenced by normal PFT values. When repopulated with a variety of stem or adult cells including human adult primary alveolar epithelial type II cells both pig and human AC scaffolds supported cell attachment and cell viability. Examination of scaffolds produced using a variety of detergents indicated that detergent choice influenced human immune response in terms of T cell activation and chemokine production.

Different properties of skin of different body sites: The root of keloid formation?

PubMed

Butzelaar, Liselotte; Niessen, Frank B; Talhout, Wendy; Schooneman, Dennis P M; Ulrich, Magda M; Beelen, Robert H J; Mink van der Molen, Aebele B

2017-09-01

The purpose of this study was to examine extracellular matrix composition, vascularization, and immune cell population of skin sites prone to keloid formation. Keloids remain a complex problem, posing esthetical as well as functional difficulties for those affected. These scars tend to develop at anatomic sites of preference. Mechanical properties of skin vary with anatomic location and depend largely on extracellular matrix composition. These differences in extracellular matrix composition, but also vascularization and resident immune cell populations might play a role in the mechanism of keloid formation. To examine this hypothesis, skin samples of several anatomic locations were taken from 24 human donors within zero to 36 hours after they had deceased. Collagen content and cross-links were determined through high-performance liquid chromatography. The expression of several genes, involved in extracellular matrix production and degradation, was measured by means of real-time PCR. (Immuno)histochemistry was performed to detect fibroblasts, collagen, elastin, blood vessels, Langerhans cells, and macrophages. Properties of skin of keloid predilections sites were compared to properties of skin from other locations (nonpredilection sites [NPS]). The results indicated that there are site specific variations in extracellular matrix properties (collagen and cross-links) as well as macrophage numbers. Moreover, predilection sites (PS) for keloid formation contain larger amounts of collagen compared to NPS, but decreased numbers of macrophages, in particular classically activated CD40 positive macrophages. In conclusion, the altered (histological, protein, and genetic) properties of skin of keloid PS may cause a predisposition for and contribute to keloid formation. © 2017 by the Wound Healing Society.

Smad4 Deficiency in Smooth Muscle Cells Initiates the Formation of Aortic Aneurysm.

PubMed

Zhang, Peng; Hou, Siyuan; Chen, Jicheng; Zhang, Jishuai; Lin, Fuyu; Ju, Renjie; Cheng, Xuan; Ma, Xiaowei; Song, Yao; Zhang, Youyi; Zhu, Minsheng; Du, Jie; Lan, Yu; Yang, Xiao

2016-02-05

Aortic aneurysm is a life-threatening cardiovascular disorder caused by the predisposition for dissection and rupture. Genetic studies have proved the involvement of the transforming growth factor-β (TGF-β) pathway in aortic aneurysm. Smad4 is the central mediator of the canonical TGF-β signaling pathway. However, the exact role of Smad4 in smooth muscle cells (SMCs) leading to the pathogenesis of aortic aneurysms is largely unknown. To determine the role of smooth muscle Smad4 in the pathogenesis of aortic aneurysms. Conditional gene knockout strategy combined with histology and expression analysis showed that Smad4 or TGF-β receptor type II deficiency in SMCs led to the occurrence of aortic aneurysms along with an upregulation of cathepsin S and matrix metallopeptidase-12, which are proteases essential for elastin degradation. We further demonstrated a previously unknown downregulation of matrix metallopeptidase-12 by TGF-β in the aortic SMCs, which is largely abrogated in the absence of Smad4. Chemotactic assay and pharmacologic treatment demonstrated that Smad4-deficient SMCs directly triggered aortic wall inflammation via the excessive production of chemokines to recruit macrophages. Monocyte/macrophage depletion or blocking selective chemokine axis largely abrogated the progression of aortic aneurysm caused by Smad4 deficiency in SMCs. The findings reveal that Smad4-dependent TGF-β signaling in SMCs protects against aortic aneurysm formation and dissection. The data also suggest important implications for novel therapeutic strategies to limit the progression of the aneurysm resulting from TGF-β signaling loss-of-function mutations. © 2015 American Heart Association, Inc.

TGF-β mediates early angiogenesis and latent fibrosis in an Emilin1-deficient mouse model of aortic valve disease

PubMed Central

Munjal, Charu; Opoka, Amy M.; Osinska, Hanna; James, Jeanne F.; Bressan, Giorgio M.; Hinton, Robert B.

2014-01-01

Aortic valve disease (AVD) is characterized by elastic fiber fragmentation (EFF), fibrosis and aberrant angiogenesis. Emilin1 is an elastin-binding glycoprotein that regulates elastogenesis and inhibits TGF-β signaling, but the role of Emilin1 in valve tissue is unknown. We tested the hypothesis that Emilin1 deficiency results in AVD, mediated by non-canonical (MAPK/phosphorylated Erk1 and Erk2) TGF-β dysregulation. Using histology, immunohistochemistry, electron microscopy, quantitative gene expression analysis, immunoblotting and echocardiography, we examined the effects of Emilin1 deficiency (Emilin1−/−) in mouse aortic valve tissue. Emilin1 deficiency results in early postnatal cell-matrix defects in aortic valve tissue, including EFF, that progress to latent AVD and premature death. The Emilin1−/− aortic valve displays early aberrant provisional angiogenesis and late neovascularization. In addition, Emilin1−/− aortic valves are characterized by early valve interstitial cell activation and proliferation and late myofibroblast-like cell activation and fibrosis. Interestingly, canonical TGF-β signaling (phosphorylated Smad2 and Smad3) is upregulated constitutively from birth to senescence, whereas non-canonical TGF-β signaling (phosphorylated Erk1 and Erk2) progressively increases over time. Emilin1 deficiency recapitulates human fibrotic AVD, and advanced disease is mediated by non-canonical (MAPK/phosphorylated Erk1 and Erk2) TGF-β activation. The early manifestation of EFF and aberrant angiogenesis suggests that these processes are crucial intermediate factors involved in disease progression and therefore might provide new therapeutic targets for human AVD. PMID:25056700

Pressure-Induced Dissolution and Reentrant Formation of Condensed, Liquid-Liquid Phase-Separated Elastomeric α-Elastin.

PubMed

Cinar, Hasan; Cinar, Süleyman; Chan, Hue Sun; Winter, Roland

2018-05-08

We investigated the combined effects of temperature and pressure on liquid-liquid phase separation (LLPS) phenomena of α-elastin up to the multi-kbar regime. FT-IR spectroscopy, CD, UV/Vis absorption, phase-contrast light and fluorescence microscopy techniques were employed to reveal structural changes and mesoscopic phase states of the system. A novel pressure-induced reentrant LLPS was observed in the intermediate temperature range. A molecular-level picture, in particular on the role of hydrophobic interactions, hydration, and void volume in controlling LLPS phenomena is presented. The potential role of the LLPS phenomena in the development of early cellular compartmentalization is discussed, which might have started in the deep sea, where pressures up to the kbar level are encountered. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of evolving biomechanical properties of tissue engineered vascular grafts in the arterial circulation.

PubMed

Udelsman, Brooks V; Khosravi, Ramak; Miller, Kristin S; Dean, Ethan W; Bersi, Matthew R; Rocco, Kevin; Yi, Tai; Humphrey, Jay D; Breuer, Christopher K

2014-06-27

We used a murine model to assess the evolving biomechanical properties of tissue engineered vascular grafts (TEVGs) implanted in the arterial circulation. The initial polymeric tubular scaffold was fabricated from poly(lactic acid)(PLA) and coated with a 50:50 copolymer of poly(caprolactone) and poly(lactic acid)(P[PC/LA]). Following seeding with syngeneic bone marrow derived mononuclear cells, TEVGs (n=50) were implanted as aortic interposition grafts in wild-type mice and monitored serially using ultrasound. A custom biaxial mechanical testing device was used to quantify the in vitro circumferential and axial mechanical properties of grafts explanted at 3 or 7 months. At both times, TEVGs were much stiffer than native tissue in both directions. Repeated mechanical testing of some TEVGs treated with elastase or collagenase suggested that elastin did not contribute significantly to the overall stiffness whereas collagen did contribute. Traditional histology and immunostaining revealed smooth muscle cell layers, significant collagen deposition, and increasing elastin production in addition to considerable scaffold at both 3 and 7 months, which likely dominated the high stiffness seen in mechanical testing. These results suggest that PLA has inadequate in vivo degradation, which impairs cell-mediated development of vascular neotissue having properties closer to native arteries. Assessing contributions of individual components, such as elastin and collagen, to the developing neovessel is needed to guide computational modeling that may help to optimize the design of the TEVG. Copyright © 2014 Elsevier Ltd. All rights reserved.

Is glycine effective against elevated blood pressure?

PubMed

El Hafidi, Mohammed; Pérez, Israel; Baños, Guadalupe

2006-01-01

Glycine, a non-essential amino acid, has been found to protect against oxidative stress in several pathological situations, and it is required for the biosynthesis of structural proteins such as elastin. As hypertension is a disease in which free radicals and large vessel elasticity are involved, this article will examine the possible mechanisms by which glycine may protect against high blood pressure. The addition of glycine to the diet reduces high blood pressure in a rat model of the metabolic syndrome. Also, glycine supplemented to the low protein diet of rat dams during pregnancy has a beneficial effect on blood pressure in their offspring. The mechanism by which glycine decreases high blood pressure can be attributed to its participation in the reduction of the generation of free radicals, increasing the availability of nitric oxide. In addition, as glycine is required for a number of critical metabolic pathways, such as the synthesis of the structural proteins collagen and elastin, the perturbation of these leads to impaired elastin formation in the aorta. This involves changes in the aorta's elastic properties, which would contribute to the development of hypertension. The use of glycine to lower high blood pressure could have a significant clinical impact in patients with the metabolic syndrome and with limited resources. On the other hand, more studies are needed to explore the beneficial effect of glycine in other models of hypertension and to investigate possible side-effects of treatment with glycine.

Confocal microscopy for automatic texture analysis of elastic fibers in histologic preparations

NASA Astrophysics Data System (ADS)

Adam, R. L.; Vieira, G.; Ferro, D. P.; de Thomaz, A. A.; Cesar, C., L.; Metze, K.

2009-07-01

Elastic fibers are an important component of many organs and tissues, such as skin, lungs, arteries, ligaments, intervertebral discs and cartilage Their function is to endow tissues with elastic recoil and resilience, to act as an important adhesion template for cells, and to regulate growth factor availability (1,2). Loss or remodeling of the elastic fiber texture occurs in many diseases. Degeneration and fragmentation of elastic fibers and aging are intimately related (3). Recently, the importance of elastin for the study of malignant tumor progression has been emphasized (4,5). Elastic tissue may be a significant reservoir of angiostatic molecules and soluble elastin as well as elastin peptides, that are inhibitors of the metastatic process in experimental tumor models (4). Elastic fibers are involved in the anatomic remodeling of chronic pulmonary diseases (6) and, especially, of diseases of the arterial wall (7, 8). The study of these phenomena is important for the understanding of the pathophysiologic basis of the diseases. Recently the role of elastic fibers in small diameter vascular graft design has been emphasized (2). The possibility to regenerate or engineer elastic fibres and tissues creates an important challenge, not only to understand the molecular basis of elastic-fibre biology (1,2), but also of its spatial arrangement and remodeling in the diseased tissues. Subtle changes of the complex elastic fiber network may be involved in the pathogenesis of diseases. Therefore a precise and objective histopathologic description is necessary.

Effect of collagen and elastin content on the burst pressure of human blood vessel seals formed with a bipolar tissue sealing system.

PubMed

Latimer, Cassandra A; Nelson, Meghan; Moore, Camille M; Martin, Kimberly E

2014-01-01

Bipolar devices are routinely used to seal blood vessels instead of sutures and clips. Recent work examining the impact of vascular proteins on bipolar seal performance found that collagen and elastin (CE) content within porcine arteries was a significant predictor of a vessel's burst pressure (VBPr). This study examined seal performance across a range of human blood vessels to investigate whether a similar relationship existed. In addition, we compared VBPr and CE content between porcine and human blood vessels. Our primary hypothesis is that higher collagen-to-elastin ratio will predict higher VBPr in human vasculature. In six cadavers, 185 blood vessels from nine anatomic locations were sealed using a bipolar electrosurgical system. A linear mixed model framework was used to evaluate the impact of vessel diameter and CE content on VBPr. The effect of CE ratio on VBPr is modified by vessel size, with CE ratio having larger influence on VBPr in smaller diameter vessels. Seal burst pressure of vessels 2-5 mm in diameter was significantly associated with their CE content. Comparison of average VBPr between species revealed porcine carotid and iliac arteries (440-670 mmHg) to be the best vessel types for predicting the seal strength of most human blood vessels (420-570 mmHg) examined. CE content significantly modified the seal strength of small to medium sized blood vessels but had limited impact on vessels >5 mm. Copyright © 2014 Elsevier Inc. All rights reserved.

Detection of airway ischaemic damage after lung transplantation by using autofluorescence imaging bronchoscopy.

PubMed

Iga, Norichika; Oto, Takahiro; Okada, Masanori; Harada, Masaaki; Nishikawa, Hitoshi; Miyoshi, Kentaroh; Otani, Shinji; Sugimoto, Seiichiro; Yamane, Masaomi; Toyooka, Shinichi; Miyoshi, Shinichiro

2014-03-01

Airway complications related to ischaemia are a major cause of morbidity after lung transplantation. Early detection of airway ischaemia and optimal management of the anastomotic site could reduce the risk of airway complications. Autofluorescence imaging (AFI) bronchoscopy has been increasingly recognized as an effective technique for detecting abnormal mucosal thickening. The aim of this study was to investigate whether AFI bronchoscopy can facilitate the detection of airway ischaemic damage in lung transplant patients. Twenty Landrace pigs were used to create a tracheal autotransplantation model. A four-ring length of trachea was excised and implanted orthotopically. The tracheal autograft was observed on postoperative days 0, 2, 4 and 7 with AFI bronchoscopy. The extent and origin of graft autofluorescence were examined using histology and measured according to fluorescence intensity. The lesions on the tracheal autografts appeared as bright green fluorescence on AFI bronchoscopy. On confocal fluorescence microscopy, high-intensity green fluorescence was observed in the elastin fibre layer of the submucosa. The fluorescence intensity of elastin was significantly higher in the graft showing fluorescence than the graft that did not show fluorescence and that at the control site. Bright green fluorescence was seen in an elastin fibre layer in the submucosa, which was likely a result of epithelial sloughing. There is a close relationship between the bright green fluorescence pattern observed using AFI bronchoscopy and airway ischaemic damage. We conclude that AFI bronchoscopy may detect airway ischaemic damage after lung transplantation.

Matrix composition and mechanics of decellularized lung scaffolds.

PubMed

Petersen, Thomas H; Calle, Elizabeth A; Colehour, Maegen B; Niklason, Laura E

2012-01-01

The utility of decellularized native tissues for tissue engineering has been widely demonstrated. Here, we examine the production of decellularized lung scaffolds from native rodent lung using two different techniques, principally defined by use of either the detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) or sodium dodecyl sulfate (SDS). All viable cellular material is removed, including at least 99% of DNA. Histochemical staining and mechanical testing indicate that collagen and elastin are retained in the decellularized matrices with CHAPS-based decellularization, while SDS-based decellularization leads to loss of collagen and decline in mechanical strength. Quantitative assays confirm that most collagen is retained with CHAPS treatment but that about 80% of collagen is lost with SDS treatment. In contrast, for both detergent methods, at least 60% of elastin content is lost along with about 95% of native proteoglycan content. Mechanical testing of the decellularized scaffolds indicates that they are mechanically similar to native lung using CHAPS decellularization, including retained tensile strength and elastic behavior, demonstrating the importance of collagen and elastin in lung mechanics. With SDS decellularization, the mechanical integrity of scaffolds is significantly diminished with some loss of elastic function as well. Finally, a simple theoretical model of peripheral lung matrix mechanics is consonant with our experimental findings. This work demonstrates the feasibility of producing a decellularized lung scaffold that can be used to study lung matrix biology and mechanics, independent of the effects of cellular components. Copyright © 2011 S. Karger AG, Basel.

Glycosaminoglycans of abdominal skin after massive weight loss in post-bariatric female patients.

PubMed

Veiga, Daniela Francescato; Bussolaro, Rodolpho A; Kobayashi, Elsa Y; Medeiros, Valquíria P; Martins, João R M; Garcia, Elvio B; Novo, Neil F; Nader, Helena B; Ferreira, Lydia M

2011-06-01

The number of post-bariatric patients had a significant increase over the last years, and a better understanding of the consequences of massive weight loss on skin is imperative. Despite weight-loss-related changes in collagen and elastin have been reported, less is known about changes in another of the matrix components of the skin, the glycosaminoglycans. The objective of this study is to evaluate abdominal skin glycosaminoglycans concentrations and perlecan and collagen III expression in post-bariatric female patients. Skin tissue samples from the abdomen of lean (n = 19) and post-bariatric (n = 24) female patients were compared. Sulfated glycosaminoglycans and hyaluronic acid were extracted, characterized and quantified. Perlecan and collagen III expression was assessed by immunofluorescence. The major glycosaminoglycans found were dermatan sultafe and hyaluronic acid; the others were found in smaller amounts. The skin of the post-bariatric patients had lower concentrations of heparan sulfate (p = 0.002) while hyaluronic acid, dermatan sulfate, and chondroitin sulfate concentrations were similar to the lean women's skin. Post-bariatric skin showed decreased expression of perlecan and increased expression of collagen III. No correlation was found among glycosaminoglycans concentrations and age, body mass index, frequency of pregnancies, or skin types, but it was observed in higher skin heparan sulfate concentrations in post-bariatric patients who had their weights stabilized for over than 24 months (p = 0.000). Abdominal skin of post-bariatric women presented decreased heparan sulfate concentrations and perlecan expression and increased expression of collagen III.

A physical map, including a BAC/PAC clone contig, of the Williams-Beuren syndrome--deletion region at 7q11.23.

PubMed

Peoples, R; Franke, Y; Wang, Y K; Pérez-Jurado, L; Paperna, T; Cisco, M; Francke, U

2000-01-01

Williams-Beuren syndrome (WBS) is a developmental disorder caused by haploinsufficiency for genes in a 2-cM region of chromosome band 7q11.23. With the exception of vascular stenoses due to deletion of the elastin gene, the various features of WBS have not yet been attributed to specific genes. Although >/=16 genes have been identified within the WBS deletion, completion of a physical map of the region has been difficult because of the large duplicated regions flanking the deletion. We present a physical map of the WBS deletion and flanking regions, based on assembly of a bacterial artificial chromosome/P1-derived artificial chromosome contig, analysis of high-throughput genome-sequence data, and long-range restriction mapping of genomic and cloned DNA by pulsed-field gel electrophoresis. Our map encompasses 3 Mb, including 1.6 Mb within the deletion. Two large duplicons, flanking the deletion, of >/=320 kb contain unique sequence elements from the internal border regions of the deletion, such as sequences from GTF2I (telomeric) and FKBP6 (centromeric). A third copy of this duplicon exists in inverted orientation distal to the telomeric flanking one. These duplicons show stronger sequence conservation with regard to each other than to the presumptive ancestral loci within the common deletion region. Sequence elements originating from beyond 7q11.23 are also present in these duplicons. Although the duplicons are not present in mice, the order of the single-copy genes in the conserved syntenic region of mouse chromosome 5 is inverted relative to the human map. A model is presented for a mechanism of WBS-deletion formation, based on the orientation of duplicons' components relative to each other and to the ancestral elements within the deletion region.

Elastin-like polypeptides: Therapeutic applications for an emerging class of nanomedicines.

PubMed

Despanie, Jordan; Dhandhukia, Jugal P; Hamm-Alvarez, Sarah F; MacKay, J Andrew

2016-10-28

Elastin-like polypeptides (ELPs) constitute a genetically engineered class of 'protein polymers' derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain soluble below a transition temperature (T t ) but form amorphous coacervates above T t . Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields. Copyright © 2015. Published by Elsevier B.V.

Modelling volumetric growth in a thick walled fibre reinforced artery

NASA Astrophysics Data System (ADS)

Eriksson, T. S. E.; Watton, P. N.; Luo, X. Y.; Ventikos, Y.

2014-12-01

A novel framework for simulating growth and remodelling (G&R) of a fibre-reinforced artery, including volumetric adaption, is proposed. We show how to implement this model into a finite element framework and propose and examine two underlying assumptions for modelling growth, namely constant individual density (CID) or adaptive individual density (AID). Moreover, we formulate a novel approach which utilises a combination of both AID and CID to simulate volumetric G&R for a tissue composed of several different constituents. We consider a special case of the G&R of an artery subjected to prescribed elastin degradation and we theorise on the assumptions and suitability of CID, AID and the mixed approach for modelling arterial biology. For simulating the volumetric changes that occur during aneurysm enlargement, we observe that it is advantageous to describe the growth of collagen using CID whilst it is preferable to model the atrophy of elastin using AID.

Improvement of physical properties of calcium phosphate cement by elastin-like polypeptide supplementation.

PubMed

Jang, Ji-Hyun; Shin, Sumi; Kim, Hyun-Jung; Jeong, Jinyoung; Jin, Hyo-Eon; Desai, Malav S; Lee, Seung-Wuk; Kim, Sun-Young

2018-03-26

Calcium phosphate cements (CPCs) are synthetic bioactive cements widely used as hard tissue substitutes. Critical limitations of use include their poor mechanical properties and poor anti-washout behaviour. To address those limitations, we combined CPC with genetically engineered elastin-like polypeptides (ELPs). We investigated the effect of the ELPs on the physical properties and biocompatibility of CPC by testing ELP/CPC composites with various liquid/powder ratios. Our results show that the addition of ELPs improved the mechanical properties of the CPC, including the microhardness, compressive strength, and washout resistance. The biocompatibility of ELP/CPC composites was also comparable to that of the CPC alone. However, supplementing CPC with ELPs functionalized with octaglutamate as a hydroxyapatite binding peptide increased the setting time of the cement. With further design and modification of our biomolecules and composites, our research will lead to products with diverse applications in biology and medicine.

Lysyl Oxidase-like-2 (LOXL2) Is a Major Isoform in Chondrocytes and Is Critically Required for Differentiation*

PubMed Central

Iftikhar, Mussadiq; Hurtado, Paola; Bais, Manish V.; Wigner, Nate; Stephens, Danielle N.; Gerstenfeld, Louis C.; Trackman, Philip C.

2011-01-01

The lysyl oxidase family is made up of five members: lysyl oxidase (LOX) and lysyl oxidase-like 1–4 (LOXL1-LOXL4). All members share conserved C-terminal catalytic domains that provide for lysyl oxidase or lysyl oxidase-like enzyme activity; and more divergent propeptide regions. LOX family enzyme activities catalyze the final enzymatic conversion required for the formation of normal biosynthetic collagen and elastin cross-links. The importance of lysyl oxidase enzyme activity to normal bone development has long been appreciated, but regulation and roles for specific LOX isoforms in bone formation in vivo is largely unexplored. Fracture healing recapitulates aspects of endochondral bone development. The present study first investigated the expression of all LOX isoforms in fracture healing. A remarkable coincidence of LOXL2 expression with the chondrogenic phase of fracture healing was found, prompting more detailed analyses of LOXL2 expression in normal growth plates, and LOXL2 expression and function in developing ATDC5 chondrogenic cells. Data show that LOXL2 is expressed by pre-hypertrophic and hypertrophic chondrocytes in vivo, and that LOXL2 expression is regulated in vitro as a function of chondrocyte differentiation. Moreover, LOXL2 knockdown studies in vitro show that LOXL2 expression is required for ATDC5 chondrocyte cell line differentiation through regulation of SNAIL and SOX9, important transcription factors that control chondrocyte differentiation. Taken together, data provide evidence that LOXL2, like LOX, is a multifunctional protein. LOXL2 promotes chondrocyte differentiation by mechanisms that are likely to include roles as both a regulator and an effector of chondrocyte differentiation. PMID:21071451

GEM-TREND: a web tool for gene expression data mining toward relevant network discovery

PubMed Central

Feng, Chunlai; Araki, Michihiro; Kunimoto, Ryo; Tamon, Akiko; Makiguchi, Hiroki; Niijima, Satoshi; Tsujimoto, Gozoh; Okuno, Yasushi

2009-01-01

Background DNA microarray technology provides us with a first step toward the goal of uncovering gene functions on a genomic scale. In recent years, vast amounts of gene expression data have been collected, much of which are available in public databases, such as the Gene Expression Omnibus (GEO). To date, most researchers have been manually retrieving data from databases through web browsers using accession numbers (IDs) or keywords, but gene-expression patterns are not considered when retrieving such data. The Connectivity Map was recently introduced to compare gene expression data by introducing gene-expression signatures (represented by a set of genes with up- or down-regulated labels according to their biological states) and is available as a web tool for detecting similar gene-expression signatures from a limited data set (approximately 7,000 expression profiles representing 1,309 compounds). In order to support researchers to utilize the public gene expression data more effectively, we developed a web tool for finding similar gene expression data and generating its co-expression networks from a publicly available database. Results GEM-TREND, a web tool for searching gene expression data, allows users to search data from GEO using gene-expression signatures or gene expression ratio data as a query and retrieve gene expression data by comparing gene-expression pattern between the query and GEO gene expression data. The comparison methods are based on the nonparametric, rank-based pattern matching approach of Lamb et al. (Science 2006) with the additional calculation of statistical significance. The web tool was tested using gene expression ratio data randomly extracted from the GEO and with in-house microarray data, respectively. The results validated the ability of GEM-TREND to retrieve gene expression entries biologically related to a query from GEO. For further analysis, a network visualization interface is also provided, whereby genes and gene annotations are dynamically linked to external data repositories. Conclusion GEM-TREND was developed to retrieve gene expression data by comparing query gene-expression pattern with those of GEO gene expression data. It could be a very useful resource for finding similar gene expression profiles and constructing its gene co-expression networks from a publicly available database. GEM-TREND was designed to be user-friendly and is expected to support knowledge discovery. GEM-TREND is freely available at . PMID:19728865

GEM-TREND: a web tool for gene expression data mining toward relevant network discovery.

PubMed

Feng, Chunlai; Araki, Michihiro; Kunimoto, Ryo; Tamon, Akiko; Makiguchi, Hiroki; Niijima, Satoshi; Tsujimoto, Gozoh; Okuno, Yasushi

2009-09-03

DNA microarray technology provides us with a first step toward the goal of uncovering gene functions on a genomic scale. In recent years, vast amounts of gene expression data have been collected, much of which are available in public databases, such as the Gene Expression Omnibus (GEO). To date, most researchers have been manually retrieving data from databases through web browsers using accession numbers (IDs) or keywords, but gene-expression patterns are not considered when retrieving such data. The Connectivity Map was recently introduced to compare gene expression data by introducing gene-expression signatures (represented by a set of genes with up- or down-regulated labels according to their biological states) and is available as a web tool for detecting similar gene-expression signatures from a limited data set (approximately 7,000 expression profiles representing 1,309 compounds). In order to support researchers to utilize the public gene expression data more effectively, we developed a web tool for finding similar gene expression data and generating its co-expression networks from a publicly available database. GEM-TREND, a web tool for searching gene expression data, allows users to search data from GEO using gene-expression signatures or gene expression ratio data as a query and retrieve gene expression data by comparing gene-expression pattern between the query and GEO gene expression data. The comparison methods are based on the nonparametric, rank-based pattern matching approach of Lamb et al. (Science 2006) with the additional calculation of statistical significance. The web tool was tested using gene expression ratio data randomly extracted from the GEO and with in-house microarray data, respectively. The results validated the ability of GEM-TREND to retrieve gene expression entries biologically related to a query from GEO. For further analysis, a network visualization interface is also provided, whereby genes and gene annotations are dynamically linked to external data repositories. GEM-TREND was developed to retrieve gene expression data by comparing query gene-expression pattern with those of GEO gene expression data. It could be a very useful resource for finding similar gene expression profiles and constructing its gene co-expression networks from a publicly available database. GEM-TREND was designed to be user-friendly and is expected to support knowledge discovery. GEM-TREND is freely available at http://cgs.pharm.kyoto-u.ac.jp/services/network.

Neighboring Genes Show Correlated Evolution in Gene Expression

PubMed Central

Ghanbarian, Avazeh T.; Hurst, Laurence D.

2015-01-01

When considering the evolution of a gene’s expression profile, we commonly assume that this is unaffected by its genomic neighborhood. This is, however, in contrast to what we know about the lack of autonomy between neighboring genes in gene expression profiles in extant taxa. Indeed, in all eukaryotic genomes genes of similar expression-profile tend to cluster, reflecting chromatin level dynamics. Does it follow that if a gene increases expression in a particular lineage then the genomic neighbors will also increase in their expression or is gene expression evolution autonomous? To address this here we consider evolution of human gene expression since the human-chimp common ancestor, allowing for both variation in estimation of current expression level and error in Bayesian estimation of the ancestral state. We find that in all tissues and both sexes, the change in gene expression of a focal gene on average predicts the change in gene expression of neighbors. The effect is highly pronounced in the immediate vicinity (<100 kb) but extends much further. Sex-specific expression change is also genomically clustered. As genes increasing their expression in humans tend to avoid nuclear lamina domains and be enriched for the gene activator 5-hydroxymethylcytosine, we conclude that, most probably owing to chromatin level control of gene expression, a change in gene expression of one gene likely affects the expression evolution of neighbors, what we term expression piggybacking, an analog of hitchhiking. PMID:25743543

Elastin-like Polypeptide Linkers for Single-Molecule Force Spectroscopy.

PubMed

Ott, Wolfgang; Jobst, Markus A; Bauer, Magnus S; Durner, Ellis; Milles, Lukas F; Nash, Michael A; Gaub, Hermann E

2017-06-27

Single-molecule force spectroscopy (SMFS) is by now well established as a standard technique in biophysics and mechanobiology. In recent years, the technique has benefitted greatly from new approaches to bioconjugation of proteins to surfaces. Indeed, optimized immobilization strategies for biomolecules and refined purification schemes are being steadily adapted and improved, which in turn has enhanced data quality. In many previously reported SMFS studies, poly(ethylene glycol) (PEG) was used to anchor molecules of interest to surfaces and/or cantilever tips. The limitation, however, is that PEG exhibits a well-known trans-trans-gauche to all-trans transition, which results in marked deviation from standard polymer elasticity models such as the worm-like chain, particularly at elevated forces. As a result, the assignment of unfolding events to protein domains based on their corresponding amino acid chain lengths is significantly obscured. Here, we provide a solution to this problem by implementing unstructured elastin-like polypeptides as linkers to replace PEG. We investigate the suitability of tailored elastin-like polypeptides linkers and perform direct comparisons to PEG, focusing on attributes that are critical for single-molecule force experiments such as linker length, monodispersity, and bioorthogonal conjugation tags. Our results demonstrate that by avoiding the ambiguous elastic response of mixed PEG/peptide systems and instead building the molecular mechanical systems with only a single bond type with uniform elastic properties, we improve data quality and facilitate data analysis and interpretation in force spectroscopy experiments. The use of all-peptide linkers allows alternative approaches for precisely defining elastic properties of proteins linked to surfaces.

Monocyte activation by smooth muscle cell-derived matrices.

PubMed

Kaufmann, J; Jorgensen, R W; Martin, B M; Franzblau, C

1990-12-01

Mononuclear phagocytes adhere to and penetrate the vessel wall endothelium and contact the subendothelial space prior to the development of the atherosclerotic plaque. In an attempt to model the early events of plaque development we used an elastin-rich, multicomponent, cell-derived matrix from neonatal rat aortic smooth muscle cells as a substratum for monocytes. Using this model, we show that human monocyte morphology and metabolism are markedly altered by the matrix substratum. When a mixed mononuclear cell population is seeded on matrix or plastic, only monocytes adhere to the matrix surface. In contrast, lymphocytes as well as monocytes adhere to the plastic surface. The matrix-adherent monocytes develop large intracellular granules and form extensive clusters of individual cells. Metabolically, these cells develop sodium fluoride resistant non-specific esterase activity and their media contain more growth factor activity and PGE2. Although total protein synthesis is equivalent in both cultures, the matrix contact induces an increase in specific proteins in the media. We also show that a purified alpha-elastin substratum induces some, but not all, of the monocyte changes seen when using the matrix substratum. Using the alpha-elastin substratum, there is selective adhesion of monocytes and increased growth factor activity, however, the cells are morphologically different from the matrix-adherent cells. Thus, the use of the smooth muscle cell-derived matrix, in conjunction with purified matrix components, serves as a model that can provide insight into the mechanisms of monocyte adhesion and stimulation by the matrix environment that exists in vivo. Such mechanisms may be particularly important in atherogenesis.

Skin findings in Williams syndrome.

PubMed

Kozel, Beth A; Bayliss, Susan J; Berk, David R; Waxler, Jessica L; Knutsen, Russell H; Danback, Joshua R; Pober, Barbara R

2014-09-01

Previous examination in a small number of individuals with Williams syndrome (also referred to as Williams-Beuren syndrome) has shown subtly softer skin and reduced deposition of elastin, an elastic matrix protein important in tissue recoil. No quantitative information about skin elasticity in individuals with Williams syndrome is available; nor has there been a complete report of dermatologic findings in this population. To fill this knowledge gap, 94 patients with Williams syndrome aged 7-50 years were recruited as part of the skin and vascular elasticity (WS-SAVE) study. They underwent either a clinical dermatologic assessment by trained dermatologists (2010 WSA family meeting) or measurement of biomechanical properties of the skin with the DermaLab™ suction cup (2012 WSA family meeting). Clinical assessment confirmed that soft skin is common in this population (83%), as is premature graying of the hair (80% of those 20 years or older), while wrinkles (92%), and abnormal scarring (33%) were detected in larger than expected proportions. Biomechanical studies detected statistically significant differences in dP (the pressure required to lift the skin), dT (the time required to raise the skin through a prescribed gradient), VE (viscoelasticity), and E (Young's modulus) relative to matched controls. The RT (retraction time) also trended longer but was not significant. The biomechanical differences noted in these patients did not correlate with the presence of vascular defects also attributable to elastin insufficiency (vascular stiffness, hypertension, and arterial stenosis) suggesting the presence of tissue specific modifiers that modulate the impact of elastin insufficiency in each tissue. © 2014 Wiley Periodicals, Inc.

Elastin-Like Recombinamers As Smart Drug Delivery Systems.

PubMed

Arias, F Javier; Santos, Mercedes; Ibanez-Fonseca, Arturo; Pina, Maria Jesus; Serrano, Sofía

2018-02-19

Drug delivery systems that are able to control the release of bioactive molecules and designed to carry drugs to target sites are of particular interest for tissue therapy. Moreover, systems comprising materials that can respond to environmental stimuli and promote self-assembly and higher order supramolecular organization are especially useful in the biomedical field. Objetive: This review focuses on biomaterials suitable for this purpose and that include elastin-like recombinamers (ELRs), a class of proteinaceous polymers bioinspired by natural elastin, designed using recombinant technologies. The self-assembly and thermoresponsive behaviour of these systems, along with their biodegradability, biocompatibility and well-defined composition as a result of their tailormade design, make them particularly attractive for controlled drug delivery. ELR-based delivery systems that allow targeted delivery are reviewed, especially ELR-drug recombinant fusion constructs, ELR-drug systems chemically bioconjugated in their monomeric and soluble forms, and drug encapsulation by nanoparticle-forming ELRs. Subsequently, the review focuses on those drug carriers in which smart release is triggered by pH or temperature with a particular focus on cancer treatments. Systems for controlled drug release based on depots and hydrogels that act as both a support and reservoir in which drugs can be stored will be described, and their applications in drug delivery discussed. Finally, smart drug-delivery systems not based on ELRs, including those comprising proteins, synthetic polymers and non-polymeric systems, will also be briefly discussed. Several different constructions based on ELRs are potential candidates for controlled drug delivery to be applied in advanced biomedical treatments. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Could the differences in the biochemistry of prostate carcinoma compared to benign prostate tissue biopsy fragments be evaluated through Raman spectroscopy?

NASA Astrophysics Data System (ADS)

Silveira, Landulfo; Leite, Kátia Ramos M.; Srougi, Miguel; Silveira, Fabrício L.; Pacheco, Marcos Tadeu T.; Zângaro, Renato A.; Pasqualucci, Carlos A.

2013-03-01

It has been proposed a spectral model to evaluate the biochemical differences between prostate carcinoma and benign fragments using dispersive Raman spectroscopy. We have examined 51 prostate fragments from surgically removed PrCa; each fragment was snap-frozen and stored (-80°C) prior spectral analysis. Raman spectrum was measured using a Raman spectrometer (830 nm excitation) coupled to a fiber-optic probe. Integration time and laser power were set to 50 s and 300 mW, respectively. It has been collected triplicate spectra from each fragment (total 153 spectra). Some samples exhibited a strong fluorescence, which was removed by a 7th order polynomial fitting. It has been developed a spectral model based on the least-squares fitting of the spectra of pure biochemicals (actin, collagen, elastin, carotene, glycogen, phosphatidylcholine, hemoglobin, and water) with the spectra of tissues, where the fitting parameters are the relative contribution of the compounds to the tissue spectrum. The spectra (600-1800 cm-1 range) are dominated by bands of proteins; it has been found a small difference in the mean spectra of PrCa compared to the benign tissue, mainly in the 1000-1400 cm-1 region, indicating similar biochemical constitution. The spectral fitting model revealed that elastin and phosphatidylcholine were increased in PrCa, whereas blood and water were reduced in malignant lesions (p < 0.05). A discrimination of PrCa from benign tissue using Mahalanobis distance applied to the contribution of elastin, hemoglobin and phosphatidylcholine resulted in sensitivity of 72% and specificity of 70%.

Amyloid associated with elastin-staining laminar aggregates in the lungs of patients diagnosed with acute respiratory distress syndrome

PubMed Central

Fan, Kang; Nagle, William A

2002-01-01

Background The heterogeneity of conditions underlying respiratory distress, whether classified clinically as acute lung injury (ALI) or the more severe acute respiratory distress syndrome (ARDS), has hampered efforts to identify and more successfully treat these patients. Examination of postmortem lungs among cases clinically diagnosed as ARDS identified a cohort that showed a consistent morphology at the light and electron microscope levels, and featured pathognomonic structures which we termed elastin-staining laminar structures (ELS). Methods Postmortem tissues were stained using the Verhoeff-Van Gieson procedure for elastic fibers, and with Congo red for examination under a polarizing microscope. Similar samples were examined by transmission EM. Results The pathognomonic ELS presented as ordered molecular aggregates when stained using the Verhoeff-van Gieson technique for elastic fibers. In several postmortem lungs, the ELS also displayed apple-green birefringence after staining with Congo red, suggesting the presence of amyloid. Remarkably, most of the postmortem lungs with ELS exhibited no significant acute inflammatory cellular response such as neutrophilic reaction, and little evidence of widespread edema except for focal intra-alveolar hemorrhage. Conclusions Postmortem lungs that exhibit the ELS constitute a morphologically-identifiable subgroup of ARDS cases. The ordered nature of the ELS, as indicated by both elastin and amyloid stains, together with little morphological evidence of inflammation or edema, suggests that this cohort of ARDS may represent another form of conformational disease. If this hypothesis is confirmed, it will require a new approach in the diagnosis and treatment of patients who exhibit this form of acute lung injury. PMID:12377106

Treatment of stress urinary incontinence with adipose tissue-derived stem cells.

PubMed

Lin, Guiting; Wang, Guifang; Banie, Lia; Ning, Hongxiu; Shindel, Alan W; Fandel, Thomas M; Lue, Tom F; Lin, Ching-Shwun

2010-01-01

Effective treatment for stress urinary incontinence (SUI) is lacking. This study investigated whether transplantation of adipose tissue-derived stem cells (ADSC) can treat SUI in a rat model. Rats were induced to develop SUI by postpartum vaginal balloon dilation and bilateral ovariectomy. ADSC were isolated from the peri-ovary fat, examined for stem cell properties, and labeled with thymidine analog BrdU or EdU. Ten rats received urethral injection of saline as a control. Twelve rats received urethral injection of EdU-labeled ADSC and six rats received intravenous injection of BrdU-labeled ADSC through the tail vein. Four weeks later, urinary voiding function was assessed by conscious cystometry. The rats were then killed and their urethras harvested for tracking of ADSC and quantification of elastin, collagen and smooth muscle contents. Cystometric analysis showed that eight out 10 rats in the control group had abnormal voiding, whereas four of 12 (33.3%) and two of six (33.3%) rats in the urethra-ADSC and tail vein-ADSC groups, respectively, had abnormal voiding. Histologic analysis showed that the ADSC-treated groups had significantly higher elastin content than the control group and, within the ADSC-treated groups, rats with normal voiding pattern also had significantly higher elastin content than rats with voiding dysfunction. ADSC-treated normal-voiding rats had significantly higher smooth muscle content than control or ADSC-treated rats with voiding dysfunction. Transplantation of ADSC via urethral or intravenous injection is effective in the treatment and/or prevention of SUI in a pre-clinical setting.

Identification of Human HK Genes and Gene Expression Regulation Study in Cancer from Transcriptomics Data Analysis

PubMed Central

Zhang, Zhang; Liu, Jingxing; Wu, Jiayan; Yu, Jun

2013-01-01

The regulation of gene expression is essential for eukaryotes, as it drives the processes of cellular differentiation and morphogenesis, leading to the creation of different cell types in multicellular organisms. RNA-Sequencing (RNA-Seq) provides researchers with a powerful toolbox for characterization and quantification of transcriptome. Many different human tissue/cell transcriptome datasets coming from RNA-Seq technology are available on public data resource. The fundamental issue here is how to develop an effective analysis method to estimate expression pattern similarities between different tumor tissues and their corresponding normal tissues. We define the gene expression pattern from three directions: 1) expression breadth, which reflects gene expression on/off status, and mainly concerns ubiquitously expressed genes; 2) low/high or constant/variable expression genes, based on gene expression level and variation; and 3) the regulation of gene expression at the gene structure level. The cluster analysis indicates that gene expression pattern is higher related to physiological condition rather than tissue spatial distance. Two sets of human housekeeping (HK) genes are defined according to cell/tissue types, respectively. To characterize the gene expression pattern in gene expression level and variation, we firstly apply improved K-means algorithm and a gene expression variance model. We find that cancer-associated HK genes (a HK gene is specific in cancer group, while not in normal group) are expressed higher and more variable in cancer condition than in normal condition. Cancer-associated HK genes prefer to AT-rich genes, and they are enriched in cell cycle regulation related functions and constitute some cancer signatures. The expression of large genes is also avoided in cancer group. These studies will help us understand which cell type-specific patterns of gene expression differ among different cell types, and particularly for cancer. PMID:23382867

Neighboring Genes Show Correlated Evolution in Gene Expression.

PubMed

Ghanbarian, Avazeh T; Hurst, Laurence D

2015-07-01

When considering the evolution of a gene's expression profile, we commonly assume that this is unaffected by its genomic neighborhood. This is, however, in contrast to what we know about the lack of autonomy between neighboring genes in gene expression profiles in extant taxa. Indeed, in all eukaryotic genomes genes of similar expression-profile tend to cluster, reflecting chromatin level dynamics. Does it follow that if a gene increases expression in a particular lineage then the genomic neighbors will also increase in their expression or is gene expression evolution autonomous? To address this here we consider evolution of human gene expression since the human-chimp common ancestor, allowing for both variation in estimation of current expression level and error in Bayesian estimation of the ancestral state. We find that in all tissues and both sexes, the change in gene expression of a focal gene on average predicts the change in gene expression of neighbors. The effect is highly pronounced in the immediate vicinity (<100 kb) but extends much further. Sex-specific expression change is also genomically clustered. As genes increasing their expression in humans tend to avoid nuclear lamina domains and be enriched for the gene activator 5-hydroxymethylcytosine, we conclude that, most probably owing to chromatin level control of gene expression, a change in gene expression of one gene likely affects the expression evolution of neighbors, what we term expression piggybacking, an analog of hitchhiking. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Atrophia maculosa varioliformis cutis.

PubMed

Kuflik, Julianne H; Schwartz, Robert A; Becker, Kenneth A; Lambert, W Clark

2005-10-01

Atrophia maculosa varioliformis cutis is a rare disease characterized by spontaneously formed facial scars in young adults. Its etiology is unknown; there may be an underlying defect of dermal elastin. We discuss a patient with this unusual disorder and review its literature.

A comprehensive study of layer-specific morphological changes in the microstructure of carotid arteries under uniaxial load.

PubMed

Krasny, Witold; Morin, Claire; Magoariec, Hélène; Avril, Stéphane

2017-07-15

The load bearing properties of large blood vessels are principally conferred by collagen and elastin networks and their microstructural organization plays an important role in the outcomes of various arterial pathologies. In particular, these fibrous networks are able to rearrange and reorient spatially during mechanical deformations. In this study, we investigate for the first time whether these well-known morphological rearrangements are the same across the whole thickness of blood vessels, and subsequently if the underlying mechanisms that govern these rearrangements can be predicted using affine kinematics. To this aim, we submitted rabbit carotid samples to uniaxial load in three distinct deformation directions, while recording live images of the 3D microstructure using multiphoton microscopy. Our results show that the observed realignment of collagen and elastin in the media layer, along with elastin of the adventitia layer, remained limited to small angles that can be predicted by affine kinematics. We show also that collagen bundles of fibers in the adventitia layer behaved in significantly different fashion. They showed a remarkable capacity to realign in the direction of the load, whatever the loading direction. Measured reorientation angles of the fibers were significantly higher than affine predictions. This remarkable property of collagen bundles in the adventitia was never observed before, it shows that the medium surrounding collagen in the adventitia undergoes complex deformations challenging traditional hyperelastic models based on mixture theories. The biomechanical properties of arteries are conferred by the rearrangement under load of the collagen and elastin fibers making up the arterial microstructure. Their kinematics under deformation is not yet characterized for all fiber networks. In this respect we have submitted samples of arterial tissue to uniaxial tension, simultaneously to confocal imaging of their microstructure. Our method allowed identifying for the first time the remarkable ability of adventitial collagen fibers to reorient in the direction of the load, achieving reorientation rotations that exceeded those predicted by affine kinematics, while all other networks followed the affine kinematics. Our results highlight new properties of the microstructure, which might play a role in the outcomes of vascular pathologies like aneurysms. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Application of community phylogenetic approaches to understand gene expression: differential exploration of venom gene space in predatory marine gastropods.

PubMed

Chang, Dan; Duda, Thomas F

2014-06-05

Predatory marine gastropods of the genus Conus exhibit substantial variation in venom composition both within and among species. Apart from mechanisms associated with extensive turnover of gene families and rapid evolution of genes that encode venom components ('conotoxins'), the evolution of distinct conotoxin expression patterns is an additional source of variation that may drive interspecific differences in the utilization of species' 'venom gene space'. To determine the evolution of expression patterns of venom genes of Conus species, we evaluated the expression of A-superfamily conotoxin genes of a set of closely related Conus species by comparing recovered transcripts of A-superfamily genes that were previously identified from the genomes of these species. We modified community phylogenetics approaches to incorporate phylogenetic history and disparity of genes and their expression profiles to determine patterns of venom gene space utilization. Less than half of the A-superfamily gene repertoire of these species is expressed, and only a few orthologous genes are coexpressed among species. Species exhibit substantially distinct expression strategies, with some expressing sets of closely related loci ('under-dispersed' expression of available genes) while others express sets of more disparate genes ('over-dispersed' expression). In addition, expressed genes show higher dN/dS values than either unexpressed or ancestral genes; this implies that expression exposes genes to selection and facilitates rapid evolution of these genes. Few recent lineage-specific gene duplicates are expressed simultaneously, suggesting that expression divergence among redundant gene copies may be established shortly after gene duplication. Our study demonstrates that venom gene space is explored differentially by Conus species, a process that effectively permits the independent and rapid evolution of venoms in these species.

Orthodontic Treatment and Maxillary Anterior Segmental Distraction Osteogenesis of a Subject with Williams–Beuren Syndrome and Isolated Cleft Palate: A Long-Term Follow-Up from the Age of 5 to 24 Years

PubMed Central

Shirota, Tatsuo; Adel, Mohamed; Takahashi, Masahiro; Haga, Shugo; Nagahama, Ryo; Nakashima, Misato; Furuhata, Mayu; Kamatani, Takaaki; Maki, Koutaro

2017-01-01

Williams–Beuren syndrome (WBS) is a rare multisystem disorder caused by a hemizygous deletion of the elastin gene on chromosome 7q11.23. WBS patients have characteristic skeletal features and dental anomalies accompanied by mental retardation, a friendly outgoing personality, and mild to moderate intellectual disability or learning problems. In this case report, we present the combined orthodontic and surgical treatment of a WBS patient with an isolated cleft palate through a long-term follow-up from the age of 5 to 24 years. During the period of active treatment, comprehensive orthodontic treatment combined with maxillary anterior segmental distraction osteogenesis and prosthetic treatment using dental implants were effective in dramatically improving the patient's malocclusion. The patient's mental abilities and the cooperation shown by the patient and her family were crucial for the success of this complex and long-term treatment course. PMID:28744380

Role of dextran in maintaining adhesive and stiffness properties of prestripped DMEK lenticules.

PubMed

Parekh, Mohit; Ruzza, Alessandro; Di Mundo, Rosa; Ferrari, Stefano; Recchia, Giuseppina; Elbadawy, Hossein; Carbone, Giuseppe; Ponzin, Diego

2017-05-11

To investigate the adhesive and stiffness properties of prestripped Descemet membrane endothelial keratoplasty (DMEK) lenticules in different preservation conditions (with and without dextran). The study included 3 conditions: (C1) tissues collected from tissue culture media (TCM), stripped and preserved in TCM; (C2) tissues collected from transport media (TM) (TCM supplemented with 6% dextran T-500), stripped and preserved in TM; and (C3) tissues collected from TCM, stripped and preserved in TM. Using a hinge, 9.5-mm stripped DMEK lenticules were restored back on the stroma and preserved for 4 days at room temperature (RT) in different conditions as above. Nine tissues, 3 from each condition, were used to check the adhesive (fibronectin, laminin, and vitronectin) and elastic properties (fibrillin, elastin, and collagen VI) using different antibodies. Six tissues, 2 from each condition, were used to check the stiffness properties after preservation using atomic force microscopy (AFM) nanoindentation method. On the Descemet membrane, fibronectin was strongly expressed in C2 and C3, whereas laminin was intense in C2 postpreservation. Vitronectin was expressed in all the conditions. Elastic proteins were not expressed in either of the conditions apart from collagen VI, which was expressed on the posterior stroma. Atomic force microscopy showed higher stiffness in C3 and an insignificant but lower rigidity in C2 as compared to C1. The tissues from C2 showed expression of adherent proteins and lower stiffness. Dextran may be suitable in preservation of DMEK grafts before and after preparation. Less stiff tissues may help reduce manipulations required in the recipient eye during DMEK surgery.

Expression of platelet-derived growth factor B is upregulated in patients with thoracic aortic dissection.

PubMed

Meng, Weixin; Liu, Shangdian; Li, Dandan; Liu, Zonghong; Yang, Hui; Sun, Bo; Liu, Hongyu

2018-04-20

Thoracic aortic dissection (TAD) is a serious condition requiring urgent treatment to avoid catastrophic consequences. The inflammatory response is involved in the occurrence and development of TAD, possibly potentiated by platelet-derived growth factors (PDGFs). This study aimed to determine whether expression of PDGF-B (a subunit of PDGF-BB) was increased in TAD patients and to explore the factors responsible for its upregulation and subsequent effects on TAD. Full-thickness ascending aorta wall specimens from TAD patients (n = 15) and control patients (n = 10) were examined for expression of PDGF-B and its receptor (PDGFRB) and in terms of morphology, inflammation, and fibrosis. Blood samples from TAD and control patients were collected to detect plasma levels of PDGF-BB and soluble elastins. Expression levels of PDGF-B, PDGFRB, and collagen I were significantly enhanced in ascending aorta wall specimens from TAD patients compared with controls. Furthermore, soluble elastic fragments and PDGF-BB were significantly increased in plasma from TAD patients compared with controls, and numerous irregular elastic fibers and macrophages were seen in the ascending aorta wall in TAD patients. An increase in elastic fragments in the aorta wall might be responsible for inducing the activation and migration of macrophages to injured sites, leading to elevated expression of PDGF-B, which in turn induces deposition of collagen, disrupts extracellular matrix homeostasis, and increases the stiffness of the aorta wall, resulting in compromised aorta compliance. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tashiro, Kanae; Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka; Shishido, Mayumi

2014-01-03

Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Westernmore » blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility.« less

Synthesis of elastic microfibrillar components fibrillin-1 and fibrillin-2 by human optic nerve head astrocytes in situ and in vitro.

PubMed

Pena, J D; Mello, P A; Hernandez, M R

2000-05-01

The purpose of this study was to identify elastic microfibrillar components fibrillin-1 and fibrillin-2 in optic nerve heads of adult normal and glaucomatous subjects, in cultured optic nerve head astrocytes (type 1B astrocytes), as well as fibrillin-1 in fetal optic nerve heads. To characterize synthesis and gene expression of microfibrillar proteins in human optic nerve heads and cultured type 1B astrocytes, light microscopy immunohistochemistry, in situ hybridization, and RT-PCR or Northern blots were performed. Our results demonstrated that fibrillin-1 was associated with blood vessels, astrocytes in the glial columns and cribriform plates, and with astrocyte processes in the nerve bundles in all samples. In glaucomatous optic nerves there was enhanced fibrillin-1 immunoreactivity, especially surrounding blood vessels. Fibrillin-2 was localized primarily to blood vessels in all samples, without qualitative differences between normal and glaucomatous samples. In fetal optic nerve heads fibrillin-1 mRNA was localized to glial cells and to the blood vessel walls. In adult optic nerve heads, there was little fibrillin-1 mRNA as detectable by in situ hybridization and RT-PCR. There was no detectable upregulation of fibrillin-1 mRNA in glaucoma. In cultured type 1B astrocytes, fibrillin-1 staining was mostly pericellular. There was little fibrillin-2 immunoreactivity. In conclusion, astrocytes from the optic nerve head deposit elastic microfibrillar components in situ and in vitro, with a predominance of fibrillin-1. Upregulation of fibrillin-1 mRNA was not observed in glaucoma, suggesting that increased transcription may occur early in the disease process. Cultures of type 1B astrocytes from the optic nerve head provides a useful model to study mechanisms regulating the interactions of elastin and the microfibrils in optic nerve head astrocytes.

Pre-Clinical Model to Study Recurrent Venous Thrombosis in the Inferior Vena Cava.

PubMed

Andraska, Elizabeth A; Luke, Catherine E; Elfline, Megan A; Henke, Samuel P; Madapoosi, Siddharth S; Metz, Allan K; Hoinville, Megan E; Wakefield, Thomas W; Henke, Peter K; Diaz, Jose A

2018-06-01

 Patients undergoing deep vein thrombosis (VT) have over 30% recurrence, directly increasing their risk of post-thrombotic syndrome. Current murine models of inferior vena cava (IVC) VT model host one thrombosis event.  We aimed to develop a murine model to study IVC recurrent VT in mice.  An initial VT was induced using the electrolytic IVC model (EIM) with constant blood flow. This approach takes advantage of the restored vein lumen 21 days after a single VT event in the EIM demonstrated by ultrasound. We then induced a second VT 21 days later, using either EIM or an IVC ligation model for comparison. The control groups were a sham surgery and, 21 days later, either EIM or IVC ligation. IVC wall and thrombus were harvested 2 days after the second insult and analysed for IVC and thrombus size, gene expression of fibrotic markers, histology for collagen and Western blot for citrullinated histone 3 (Cit-H3) and fibrin.  Ultrasound confirmed the first VT and its progressive resolution with an anatomical channel allowing room for the second thrombus by day 21. As compared with a primary VT, recurrent VT has heavier walls with significant up-regulation of transforming growth factor-β (TGF-β), elastin, interleukin (IL)-6, matrix metallopeptidase 9 (MMP9), MMP2 and a thrombus with high citrullinated histone-3 and fibrin content.  Experimental recurrent thrombi are structurally and compositionally different from the primary VT, with a greater pro-fibrotic remodelling vein wall profile. This work provides a VT recurrence IVC model that will help to improve the current understanding of the biological mechanisms and directed treatment of recurrent VT. Schattauer GmbH Stuttgart.

The role of extracellular matrix components in pin bone attachments during storage-a comparison between farmed Atlantic salmon (Salmo salar) and cod (Gadus morhua L.).

PubMed

Rønning, Sissel B; Østbye, Tone-Kari; Krasnov, Aleksei; Vuong, Tram T; Veiseth-Kent, Eva; Kolset, Svein O; Pedersen, Mona E

2017-04-01

Pin bones represent a major problem for processing and quality of fish products. Development of methods of removal requires better knowledge of the pin bones' attachment to the muscle and structures involved in the breakdown during loosening. In this study, pin bones from cod and salmon were dissected from fish fillets after slaughter or storage on ice for 5 days, and thereafter analysed with molecular methods, which revealed major differences between these species before and after storage. The connective tissue (CT) attaches the pin bone to the muscle in cod, while the pin bones in salmon are embedded in adipose tissue. Collagens, elastin, lectin-binding proteins and glycosaminoglycans (GAGs) are all components of the attachment site, and this differ between salmon and cod, resulting in a CT in cod that is more resistant to enzymatic degradation compared to the CT in salmon. Structural differences are reflected in the composition of transcriptome. Microarray analysis comparing the attachment sites of the pin bones with a reference muscle sample showed limited differences in salmon. In cod, on the other hand, the variances were substantial, and the gene expression profiles suggested difference in myofibre structure, metabolism and cell processes between the pin bone attachment site and the reference muscle. Degradation of the connective tissue occurs closest to the pin bones and not in the neighbouring tissue, which was shown using light microscopy. This study shows that the attachment of the pin bones in cod and salmon is different; therefore, the development of methods for removal should be tailored to each individual species.

A bioinspired elastin-based protein for a cytocompatible underwater adhesive.

PubMed

Brennan, M Jane; Kilbride, Bridget F; Wilker, Jonathan J; Liu, Julie C

2017-04-01

The development of adhesives that can be applied and create strong bonds underwater is a significant challenge for materials engineering. When the adhesive is intended for biomedical applications, further criteria, such as biocompatibility, must be met. Current biomedical adhesive technologies do not meet these needs. In response, we designed a bioinspired protein system that shows promise to achieve biocompatible underwater adhesion coupled with environmentally responsive behavior that is "smart" - that is, it can be tuned to suit a specific application. The material, ELY 16 , is constructed from an elastin-like polypeptide (ELP) that can be produced in high yields from Escherichia coli and can coacervate in response to environmental factors such as temperature, pH, and salinity. To confer wet adhesion, we utilized design principles from marine organisms such as mussels and sandcastle worms. When expressed, ELY 16 is rich in tyrosine. Upon modification with the tyrosinase enzyme to form mELY 16 , the tyrosine residues are converted to 3,4-dihydroxyphenylalanine (DOPA). Both ELY 16 and mELY 16 exhibit cytocompatibility and significant dry adhesion strength (>2 MPa). Modification with DOPA increases protein adsorption to glass and provides moderate adhesion strength (∼240 kPa) in a highly humid environment. Furthermore, this ELP exhibits a tunable phase transition behavior that can be formulated to coacervate in physiological conditions and provides a convenient mechanism for application underwater. Finally, mELY 16 possesses significantly higher adhesion strength in dry, humid, and underwater environments compared with a commercially available fibrin sealant. To our knowledge, mELY 16 provides the strongest bonds of any rationally designed protein when used completely underwater, and its high yields make it more viable for commercial application compared to natural adhesive proteins. In conclusion, this ELP shows great potential to be a new "smart" underwater adhesive. Copyright © 2017 Elsevier Ltd. All rights reserved.

FARO server: Meta-analysis of gene expression by matching gene expression signatures to a compendium of public gene expression data.

PubMed

Manijak, Mieszko P; Nielsen, Henrik B

2011-06-11

Although, systematic analysis of gene annotation is a powerful tool for interpreting gene expression data, it sometimes is blurred by incomplete gene annotation, missing expression response of key genes and secondary gene expression responses. These shortcomings may be partially circumvented by instead matching gene expression signatures to signatures of other experiments. To facilitate this we present the Functional Association Response by Overlap (FARO) server, that match input signatures to a compendium of 242 gene expression signatures, extracted from more than 1700 Arabidopsis microarray experiments. Hereby we present a publicly available tool for robust characterization of Arabidopsis gene expression experiments which can point to similar experimental factors in other experiments. The server is available at http://www.cbs.dtu.dk/services/faro/.

Digital gene expression analysis of the zebra finch genome

PubMed Central

2010-01-01

Background In order to understand patterns of adaptation and molecular evolution it is important to quantify both variation in gene expression and nucleotide sequence divergence. Gene expression profiling in non-model organisms has recently been facilitated by the advent of massively parallel sequencing technology. Here we investigate tissue specific gene expression patterns in the zebra finch (Taeniopygia guttata) with special emphasis on the genes of the major histocompatibility complex (MHC). Results Almost 2 million 454-sequencing reads from cDNA of six different tissues were assembled and analysed. A total of 11,793 zebra finch transcripts were represented in this EST data, indicating a transcriptome coverage of about 65%. There was a positive correlation between the tissue specificity of gene expression and non-synonymous to synonymous nucleotide substitution ratio of genes, suggesting that genes with a specialised function are evolving at a higher rate (or with less constraint) than genes with a more general function. In line with this, there was also a negative correlation between overall expression levels and expression specificity of contigs. We found evidence for expression of 10 different genes related to the MHC. MHC genes showed relatively tissue specific expression levels and were in general primarily expressed in spleen. Several MHC genes, including MHC class I also showed expression in brain. Furthermore, for all genes with highest levels of expression in spleen there was an overrepresentation of several gene ontology terms related to immune function. Conclusions Our study highlights the usefulness of next-generation sequence data for quantifying gene expression in the genome as a whole as well as in specific candidate genes. Overall, the data show predicted patterns of gene expression profiles and molecular evolution in the zebra finch genome. Expression of MHC genes in particular, corresponds well with expression patterns in other vertebrates. PMID:20359325

The Role of Neprilysin in Regulating the Hair Cycle

PubMed Central

Morisaki, Naoko; Ohuchi, Atsushi; Moriwaki, Shigeru

2013-01-01

In most mammals, each hair follicle undergoes a cyclic process of growing, regressing and resting phases (anagen, catagen, telogen, respectively) called the hair cycle. Various biological factors have been reported to regulate or to synchronize with the hair cycle. Some factors involved in the extracellular matrix, which is a major component of skin tissue, are also thought to regulate the hair cycle. We have focused on an enzyme that degrades elastin, which is associated with skin elasticity. Since our previous study identified skin fibroblast elastase as neprilysin (NEP), we examined the fluctuation of NEP enzyme activity and its expression during the synchronized hair cycle of rats. NEP activity in the skin was elevated at early anagen, and decreased during catagen to telogen. The expression of NEP mRNA and protein levels was modulated similarly. Immunostaining showed changes in NEP localization throughout the hair cycle, from the follicular epithelium during early anagen to the dermal papilla during catagen. To determine whether NEP plays an important role in regulating the hair cycle, we used a specific inhibitor of NEP (NPLT). NPLT was applied topically daily to the dorsal skin of C3H mice, which had been depilated in advance. Mice treated with NPLT had significantly suppressed hair growth. These data suggest that NEP plays an important role in regulating the hair cycle by its increased expression and activity in the follicular epithelium during early anagen. PMID:23418484

A novel approach for human whole transcriptome analysis based on absolute gene expression of microarray data.

PubMed

Bikel, Shirley; Jacobo-Albavera, Leonor; Sánchez-Muñoz, Fausto; Cornejo-Granados, Fernanda; Canizales-Quinteros, Samuel; Soberón, Xavier; Sotelo-Mundo, Rogerio R; Del Río-Navarro, Blanca E; Mendoza-Vargas, Alfredo; Sánchez, Filiberto; Ochoa-Leyva, Adrian

2017-01-01

In spite of the emergence of RNA sequencing (RNA-seq), microarrays remain in widespread use for gene expression analysis in the clinic. There are over 767,000 RNA microarrays from human samples in public repositories, which are an invaluable resource for biomedical research and personalized medicine. The absolute gene expression analysis allows the transcriptome profiling of all expressed genes under a specific biological condition without the need of a reference sample. However, the background fluorescence represents a challenge to determine the absolute gene expression in microarrays. Given that the Y chromosome is absent in female subjects, we used it as a new approach for absolute gene expression analysis in which the fluorescence of the Y chromosome genes of female subjects was used as the background fluorescence for all the probes in the microarray. This fluorescence was used to establish an absolute gene expression threshold, allowing the differentiation between expressed and non-expressed genes in microarrays. We extracted the RNA from 16 children leukocyte samples (nine males and seven females, ages 6-10 years). An Affymetrix Gene Chip Human Gene 1.0 ST Array was carried out for each sample and the fluorescence of 124 genes of the Y chromosome was used to calculate the absolute gene expression threshold. After that, several expressed and non-expressed genes according to our absolute gene expression threshold were compared against the expression obtained using real-time quantitative polymerase chain reaction (RT-qPCR). From the 124 genes of the Y chromosome, three genes (DDX3Y, TXLNG2P and EIF1AY) that displayed significant differences between sexes were used to calculate the absolute gene expression threshold. Using this threshold, we selected 13 expressed and non-expressed genes and confirmed their expression level by RT-qPCR. Then, we selected the top 5% most expressed genes and found that several KEGG pathways were significantly enriched. Interestingly, these pathways were related to the typical functions of leukocytes cells, such as antigen processing and presentation and natural killer cell mediated cytotoxicity. We also applied this method to obtain the absolute gene expression threshold in already published microarray data of liver cells, where the top 5% expressed genes showed an enrichment of typical KEGG pathways for liver cells. Our results suggest that the three selected genes of the Y chromosome can be used to calculate an absolute gene expression threshold, allowing a transcriptome profiling of microarray data without the need of an additional reference experiment. Our approach based on the establishment of a threshold for absolute gene expression analysis will allow a new way to analyze thousands of microarrays from public databases. This allows the study of different human diseases without the need of having additional samples for relative expression experiments.

Differential gene expression analysis in glioblastoma cells and normal human brain cells based on GEO database.

PubMed

Wang, Anping; Zhang, Guibin

2017-11-01

The differentially expressed genes between glioblastoma (GBM) cells and normal human brain cells were investigated to performed pathway analysis and protein interaction network analysis for the differentially expressed genes. GSE12657 and GSE42656 gene chips, which contain gene expression profile of GBM were obtained from Gene Expression Omniub (GEO) database of National Center for Biotechnology Information (NCBI). The 'limma' data packet in 'R' software was used to analyze the differentially expressed genes in the two gene chips, and gene integration was performed using 'RobustRankAggreg' package. Finally, pheatmap software was used for heatmap analysis and Cytoscape, DAVID, STRING and KOBAS were used for protein-protein interaction, Gene Ontology (GO) and KEGG analyses. As results: i) 702 differentially expressed genes were identified in GSE12657, among those genes, 548 were significantly upregulated and 154 were significantly downregulated (p<0.01, fold-change >1), and 1,854 differentially expressed genes were identified in GSE42656, among the genes, 1,068 were significantly upregulated and 786 were significantly downregulated (p<0.01, fold-change >1). A total of 167 differentially expressed genes including 100 upregulated genes and 67 downregulated genes were identified after gene integration, and the genes showed significantly different expression levels in GBM compared with normal human brain cells (p<0.05). ii) Interactions between the protein products of 101 differentially expressed genes were identified using STRING and expression network was established. A key gene, called CALM3, was identified by Cytoscape software. iii) GO enrichment analysis showed that differentially expressed genes were mainly enriched in 'neurotransmitter:sodium symporter activity' and 'neurotransmitter transporter activity', which can affect the activity of neurotransmitter transportation. KEGG pathway analysis showed that the differentially expressed genes were mainly enriched in 'protein processing in endoplasmic reticulum', which can affect protein processing in endoplasmic reticulum. The results showed that: i) 167 differentially expressed genes were identified from two gene chips after integration; and ii) protein interaction network was established, and GO and KEGG pathway analyses were successfully performed to identify and annotate the key gene, which provide new insights for the studies on GBN at gene level.

Discovery and validation of a glioblastoma co-expressed gene module

PubMed Central

Dunwoodie, Leland J.; Poehlman, William L.; Ficklin, Stephen P.; Feltus, Frank Alexander

2018-01-01

Tumors exhibit complex patterns of aberrant gene expression. Using a knowledge-independent, noise-reducing gene co-expression network construction software called KINC, we created multiple RNAseq-based gene co-expression networks relevant to brain and glioblastoma biology. In this report, we describe the discovery and validation of a glioblastoma-specific gene module that contains 22 co-expressed genes. The genes are upregulated in glioblastoma relative to normal brain and lower grade glioma samples; they are also hypo-methylated in glioblastoma relative to lower grade glioma tumors. Among the proneural, neural, mesenchymal, and classical glioblastoma subtypes, these genes are most-highly expressed in the mesenchymal subtype. Furthermore, high expression of these genes is associated with decreased survival across each glioblastoma subtype. These genes are of interest to glioblastoma biology and our gene interaction discovery and validation workflow can be used to discover and validate co-expressed gene modules derived from any co-expression network. PMID:29541392

Discovery and validation of a glioblastoma co-expressed gene module.

PubMed

Dunwoodie, Leland J; Poehlman, William L; Ficklin, Stephen P; Feltus, Frank Alexander

2018-02-16

Tumors exhibit complex patterns of aberrant gene expression. Using a knowledge-independent, noise-reducing gene co-expression network construction software called KINC, we created multiple RNAseq-based gene co-expression networks relevant to brain and glioblastoma biology. In this report, we describe the discovery and validation of a glioblastoma-specific gene module that contains 22 co-expressed genes. The genes are upregulated in glioblastoma relative to normal brain and lower grade glioma samples; they are also hypo-methylated in glioblastoma relative to lower grade glioma tumors. Among the proneural, neural, mesenchymal, and classical glioblastoma subtypes, these genes are most-highly expressed in the mesenchymal subtype. Furthermore, high expression of these genes is associated with decreased survival across each glioblastoma subtype. These genes are of interest to glioblastoma biology and our gene interaction discovery and validation workflow can be used to discover and validate co-expressed gene modules derived from any co-expression network.

Gender-Specific Gene Expression in Post-Mortem Human Brain: Localization to Sex Chromosomes

PubMed Central

Vawter, Marquis P; Evans, Simon; Choudary, Prabhakara; Tomita, Hiroaki; Meador-Woodruff, Jim; Molnar, Margherita; Li, Jun; Lopez, Juan F; Myers, Rick; Cox, David; Watson, Stanley J; Akil, Huda; Jones, Edward G; Bunney, William E

2011-01-01

Gender differences in brain development and in the prevalence of neuropsychiatric disorders such as depression have been reported. Gender differences in human brain might be related to patterns of gene expression. Microarray technology is one useful method for investigation of gene expression in brain. We investigated gene expression, cell types, and regional expression patterns of differentially expressed sex chromosome genes in brain. We profiled gene expression in male and female dorsolateral prefrontal cortex, anterior cingulate cortex, and cerebellum using the Affymetrix oligonucleotide microarray platform. Differentially expressed genes between males and females on the Y chromosome (DBY, SMCY, UTY, RPS4Y, and USP9Y) and X chromosome (XIST) were confirmed using real-time PCR measurements. In situ hybridization confirmed the differential expression of gender-specific genes and neuronal expression of XIST, RPS4Y, SMCY, and UTY in three brain regions examined. The XIST gene, which silences gene expression on regions of the X chromosome, is expressed in a subset of neurons. Since a subset of neurons express gender-specific genes, neural subpopulations may exhibit a subtle sexual dimorphism at the level of differences in gene regulation and function. The distinctive pattern of neuronal expression of XIST, RPS4Y, SMCY, and UTY and other sex chromosome genes in neuronal subpopulations may possibly contribute to gender differences in prevalence noted for some neuropsychiatric disorders. Studies of the protein expression of these sex- chromosome-linked genes in brain tissue are required to address the functional consequences of the observed gene expression differences. PMID:14583743

THERMALLY TRIGGERED PURIFICATION AND IMMOBILIZATION OF ELASTIN-OPH FUSION. (R829606)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Gene expression variability in human hepatic drug metabolizing enzymes and transporters.

PubMed

Yang, Lun; Price, Elvin T; Chang, Ching-Wei; Li, Yan; Huang, Ying; Guo, Li-Wu; Guo, Yongli; Kaput, Jim; Shi, Leming; Ning, Baitang

2013-01-01

Interindividual variability in the expression of drug-metabolizing enzymes and transporters (DMETs) in human liver may contribute to interindividual differences in drug efficacy and adverse reactions. Published studies that analyzed variability in the expression of DMET genes were limited by sample sizes and the number of genes profiled. We systematically analyzed the expression of 374 DMETs from a microarray data set consisting of gene expression profiles derived from 427 human liver samples. The standard deviation of interindividual expression for DMET genes was much higher than that for non-DMET genes. The 20 DMET genes with the largest variability in the expression provided examples of the interindividual variation. Gene expression data were also analyzed using network analysis methods, which delineates the similarities of biological functionalities and regulation mechanisms for these highly variable DMET genes. Expression variability of human hepatic DMET genes may affect drug-gene interactions and disease susceptibility, with concomitant clinical implications.

A novel approach for human whole transcriptome analysis based on absolute gene expression of microarray data

PubMed Central

Bikel, Shirley; Jacobo-Albavera, Leonor; Sánchez-Muñoz, Fausto; Cornejo-Granados, Fernanda; Canizales-Quinteros, Samuel; Soberón, Xavier; Sotelo-Mundo, Rogerio R.; del Río-Navarro, Blanca E.; Mendoza-Vargas, Alfredo; Sánchez, Filiberto

2017-01-01

Background In spite of the emergence of RNA sequencing (RNA-seq), microarrays remain in widespread use for gene expression analysis in the clinic. There are over 767,000 RNA microarrays from human samples in public repositories, which are an invaluable resource for biomedical research and personalized medicine. The absolute gene expression analysis allows the transcriptome profiling of all expressed genes under a specific biological condition without the need of a reference sample. However, the background fluorescence represents a challenge to determine the absolute gene expression in microarrays. Given that the Y chromosome is absent in female subjects, we used it as a new approach for absolute gene expression analysis in which the fluorescence of the Y chromosome genes of female subjects was used as the background fluorescence for all the probes in the microarray. This fluorescence was used to establish an absolute gene expression threshold, allowing the differentiation between expressed and non-expressed genes in microarrays. Methods We extracted the RNA from 16 children leukocyte samples (nine males and seven females, ages 6–10 years). An Affymetrix Gene Chip Human Gene 1.0 ST Array was carried out for each sample and the fluorescence of 124 genes of the Y chromosome was used to calculate the absolute gene expression threshold. After that, several expressed and non-expressed genes according to our absolute gene expression threshold were compared against the expression obtained using real-time quantitative polymerase chain reaction (RT-qPCR). Results From the 124 genes of the Y chromosome, three genes (DDX3Y, TXLNG2P and EIF1AY) that displayed significant differences between sexes were used to calculate the absolute gene expression threshold. Using this threshold, we selected 13 expressed and non-expressed genes and confirmed their expression level by RT-qPCR. Then, we selected the top 5% most expressed genes and found that several KEGG pathways were significantly enriched. Interestingly, these pathways were related to the typical functions of leukocytes cells, such as antigen processing and presentation and natural killer cell mediated cytotoxicity. We also applied this method to obtain the absolute gene expression threshold in already published microarray data of liver cells, where the top 5% expressed genes showed an enrichment of typical KEGG pathways for liver cells. Our results suggest that the three selected genes of the Y chromosome can be used to calculate an absolute gene expression threshold, allowing a transcriptome profiling of microarray data without the need of an additional reference experiment. Discussion Our approach based on the establishment of a threshold for absolute gene expression analysis will allow a new way to analyze thousands of microarrays from public databases. This allows the study of different human diseases without the need of having additional samples for relative expression experiments. PMID:29230367

Strong correlation of elastin deletions, detected by FISH, with Williams syndrome: Evaluation of 235 patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowery, M.C.; Brothman, L.J.; Leonard, C.O.

1995-07-01

Williams syndrome (WS) is generally characterized by mental deficiency, gregarious personality, dysmorphic facies, supravalvular aortic stenosis, and idiopathic infantile hypercalcemia. Patients with WS show allelic loss of elastin (ELN), exhibiting a submicroscopic deletion, at 7q11.23, detectable by FISH. Hemizygosity is likely the cause of vascular abnormalities in WS patients. A series of 235 patients was studied, and molecular cytogenetic deletions were seen in 96% of patients with classic WS. Patients included 195 solicited through the Williams Syndrome Association (WSA), plus 40 clinical cytogenetics cases referred by primary-care physicians. Photographs and medical records of most WSA subjects were reviewed, and patientsmore » were identified as {open_quotes}classic{open_quotes} (n = 114) or{open_quotes}uncertain{close_quotes} (n = 39). An additional 42 WSA patients were evaluated without clinical information. FISH was performed with biotinylated ELN cosmids on metaphase cells from immortalized lymphoblastoid lines from WSA patients and after high-resolution banding analysis on clinical referral patients. An alpha-satellite probe for chromosome 7 was included in hybridizations, as an internal control. Ninety-six percent of the patients with classic WS showed a deletion in one ELN allele; four of these did not show a deletion. Of the uncertain WS patients, only 3 of 39 showed a deletion. Of the 42 who were not classified phenotypically, because of lack of clinical information, 25 patients (60%) showed a deletion. Thirty-eight percent (15/40) of clinical cytogenetics cases showed an ELN deletion and no cytogenetic deletion by banded analysis. These results support the usefulness of FISH for the detection of elastin deletions as an initial diagnostic assay for WS. 14 refs., 2 figs., 4 tabs.« less

Genetically Programmable Thermoresponsive Plasmonic Gold/Silk-Elastin Protein Core/Shell Nanoparticles

PubMed Central

2015-01-01

The design and development of future molecular photonic/electronic systems pose the challenge of integrating functional molecular building blocks in a controlled, tunable, and reproducible manner. The modular nature and fidelity of the biosynthesis method provides a unique chemistry approach to one-pot synthesis of environmental factor-responsive chimeric proteins capable of energy conversion between the desired forms. In this work, facile tuning of dynamic thermal response in plasmonic nanoparticles was facilitated by genetic engineering of the structure, size, and self-assembly of the shell silk-elastin-like protein polymers (SELPs). Recombinant DNA techniques were implemented to synthesize a new family of SELPs, S4E8Gs, with amino acid repeats of [(GVGVP)4(GGGVP)(GVGVP)3(GAGAGS)4] and tunable molecular weight. The temperature-reversible conformational switching between the hydrophilic random coils and the hydrophobic β-turns in the elastin blocks were programmed to between 50 and 60 °C by site-specific glycine mutation, as confirmed by variable-temperature proton NMR and circular dichroism (CD) spectroscopy, to trigger the nanoparticle aggregation. The dynamic self-aggregation/disaggregation of the Au-SELPs nanoparticles was regulated in size and pattern by the β-sheet-forming, thermally stable silk blocks, as revealed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The thermally reversible, shell dimension dependent, interparticle plasmon coupling was investigated by both variable-temperature UV–vis spectroscopy and finite-difference time-domain (FDTD)-based simulations. Good agreement between the calculated and measured spectra sheds light on design and synthesis of responsive plasmonic nanostructures by independently tuning the refractive index and size of the SELPs through genetic engineering. PMID:24712906

Enzymatic cross-linking of human recombinant elastin (HELP) as biomimetic approach in vascular tissue engineering.

PubMed

Bozzini, Sabrina; Giuliano, Liliana; Altomare, Lina; Petrini, Paola; Bandiera, Antonella; Conconi, Maria Teresa; Farè, Silvia; Tanzi, Maria Cristina

2011-12-01

The use of polymers naturally occurring in the extracellular matrix (ECM) is a promising strategy in regenerative medicine. If compared to natural ECM proteins, proteins obtained by recombinant DNA technology have intrinsic advantages including reproducible macromolecular composition, sequence and molecular mass, and overcoming the potential pathogens transmission related to polymers of animal origin. Among ECM-mimicking materials, the family of recombinant elastin-like polymers is proposed for drug delivery applications and for the repair of damaged elastic tissues. This work aims to evaluate the potentiality of a recombinant human elastin-like polypeptide (HELP) as a base material of cross-linked matrices for regenerative medicine. The cross-linking of HELP was accomplished by the insertion of cross-linking sites, glutamine and lysine, in the recombinant polymer and generating ε-(γ-glutamyl) lysine links through the enzyme transglutaminase. The cross-linking efficacy was estimated by infrared spectroscopy. Freeze-dried cross-linked matrices showed swelling ratios in deionized water (≈2500%) with good structural stability up to 24 h. Mechanical compression tests, performed at 37°C in wet conditions, in a frequency sweep mode, indicated a storage modulus of 2/3 kPa, with no significant changes when increasing number of cycles or frequency. These results demonstrate the possibility to obtain mechanically resistant hydrogels via enzymatic crosslinking of HELP. Cytotoxicity tests of cross-linked HELP were performed with human umbilical vein endothelial cells, by use of transwell filter chambers for 1-7 days, or with its extracts in the opportune culture medium for 24 h. In both cases no cytotoxic effects were observed in comparison with the control cultures. On the whole, the results suggest the potentiality of this genetically engineered HELP for regenerative medicine applications, particularly for vascular tissue regeneration.

Morphological and biochemical studies of the elastic fibres in the craniomandibular joint articular disc of the tight-skin mouse.

PubMed

O'dell, N L; Burlison, S K; Starcher, B C; Pennington, C B

1996-05-01

The tight-skin (TSK) mouse is characterized by the hyperplasia of loose connective tissues, and of excessive growth of cartilage and of bones including the mandible. Since the fibroelastic connective tissues of the craniomandibular joint (CMJ) are essential to the functions of this joint, the present histological study compared the presence and general distribution of elastic fibres in CMJ discal tissues of TSK and normal mice. The excised CMJs were processed for light microscopy. The tissues were fixed, demineralized, embedded in paraffin, sectioned and then stained with resorcin-fuchsin to demonstrate elastic fibres. There were no obvious histological differences in either the amount or the distribution of elastic fibres in the discs from the two groups. In both groups, elastic fibres were found in the disc and in many of the attachments of the disc to the mandible and squamosal bone. In addition to the morphological preparations, articular discs and samples of lung tissue were excised from other mice and subjected to a radioimmunoassay for desmosine in order to estimate the amounts of elastin in these tissues; the amount of elastin was significantly reduced in the TSK lung, but the amounts of elastin in the TSK and normal CMJ discal tissues were not significantly different statistically. These morphological and histochemical results suggest that the distribution and quantity of elastic fibres in the TSK mouse disc are not significantly different from those in the normal mouse articular disc. Moreover, these data may be interpreted to either suggest a differential effect on the elastic fibres in different TSK tissues, or to support the suggestion that abnormal degradation of elastic fibres may not be characteristic of the TSK mouse.

Fractional versus ablative erbium:yttrium-aluminum-garnet laser resurfacing for facial rejuvenation: an objective evaluation.

PubMed

El-Domyati, Moetaz; Abd-El-Raheem, Talal; Abdel-Wahab, Hossam; Medhat, Walid; Hosam, Wael; El-Fakahany, Hasan; Al Anwer, Mustafa

2013-01-01

Laser is one of the main tools for skin resurfacing. Erbium:yttrium-aluminum-garnet (Er:YAG) was the second ablative laser, after carbon dioxide, emitting wavelength of 2940 nm. Fractional laser resurfacing has been developed to overcome the drawbacks of ablative lasers. We aimed to objectively evaluate the histopathological and immunohistochemical effects of Er:YAG 2940-nm laser for facial rejuvenation (multiple sessions of fractional vs single session of ablative Er:YAG laser). Facial resurfacing with single-session ablative Er:YAG laser was performed on 6 volunteers. Another 6 were resurfaced using fractional Er:YAG laser (4 sessions). Histopathological (hematoxylin-eosin, orcein, Masson trichrome, and picrosirius red stains) and immunohistochemical assessment for skin biopsy specimens were done before laser resurfacing and after 1 and 6 months. Histometry for epidermal thickness and quantitative assessment for neocollagen formation; collagen I, III, and VII; elastin; and tropoelastin were done for all skin biopsy specimens. Both lasers resulted in increased epidermal thickness. Dermal collagen showed increased neocollagen formation with increased concentration of collagen types I, III, and VII. Dermal elastic tissue studies revealed decreased elastin whereas tropoelastin concentration increased after laser resurfacing. Neither laser showed significant difference between their effects clinically and on dermal collagen. Changes in epidermal thickness, elastin, and tropoelastin were significantly more marked after ablative laser. The small number of patients is a limitation, yet the results show significant improvement. Multiple sessions of fractional laser have comparable effects to a single session of ablative Er:YAG laser on dermal collagen but ablative laser has more effect on elastic tissue and epidermis. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Characterization of chronic vocal fold scarring in a rabbit model.

PubMed

Rousseau, Bernard; Hirano, Shigeru; Chan, Roger W; Welham, Nathan V; Thibeault, Susan L; Ford, Charles N; Bless, Diane M

2004-03-01

The purpose of the current study was to assess the histologic and rheologic properties of the scarred vocal fold lamina propria during a chronic phase of wound repair in a rabbit model. Eighteen rabbit larynges were scarred using a procedure that involved stripping the vocal fold lamina propria down to the thyroarytenoid muscle, using 3-mm microforceps. The approximate dimension of injury to the vocal fold was 3 x 1.5 x 0.5 mm [length x width x depth]. At 6 months postoperatively, histologic analysis of the scarred and control lamina propria in eight of these rabbits was completed for collagen, procollagen, elastin, and hyaluronic acid. Compared with control samples, scarred tissue samples revealed fragmented and disorganized elastin fibers. Additionally, collagen was significantly increased, organized, and formed thick bundles in the scarred vocal fold lamina propria. Measurements of the viscoelastic shear properties of the scarred and control lamina propria in the remaining 10 rabbits revealed increased elastic shear modulus (G') in 8 of 10 scarred samples and increased dynamic viscosity (eta') in 9 of 10 scarred samples. Although rheologic differences were not statistically significant, they revealed that on average, scarred samples were stiffer and more viscous than the normal controls. Histologic data are interpreted as indicating that by 6 months postinjury, the scarred rabbit vocal fold has reached a mature phase of wound repair, characterized by an increased, organized, and thick bundle collagen matrix. Rheologic data are interpreted as providing support for the potential role of increased, thick bundle collagen, and a disorganized elastin network on shear stiffness and dynamic viscosity in the chronic vocal fold scar. Based on these results, a 6-month postoperative time frame is proposed for future studies of chronic vocal fold scarring using the rabbit animal model.

Induction of Macrophage Chemotaxis by Aortic Extracts from Patients with Marfan Syndrome Is Related to Elastin Binding Protein

PubMed Central

Guo, Gao; Gehle, Petra; Doelken, Sandra; Martin-Ventura, José Luis; von Kodolitsch, Yskert; Hetzer, Roland; Robinson, Peter N.

2011-01-01

Marfan syndrome is an autosomal dominantly inherited disorder of connective tissue with prominent skeletal, ocular, and cardiovascular manifestations. Aortic aneurysm and dissection are the major determinants of premature death in untreated patients. In previous work, we showed that extracts of aortic tissues from the mgR mouse model of Marfan syndrome showed increased chemotactic stimulatory activity related to the elastin-binding protein. Aortic samples were collected from 6 patients with Marfan syndrome and 8 with isolated aneurysms of the ascending aorta. Control samples were obtained from 11 organ donors without known vascular or connective tissue diseases. Soluble proteins extracted from the aortic samples of the two patient groups were compared against buffer controls and against the aortic samples from controls with respect to the ability to induce macrophage chemotaxis as measured using a modified Boyden chamber, as well as the reactivity to a monoclonal antibody BA4 against bioactive elastin peptides using ELISA. Samples from Marfan patients displayed a statistically significant increase in chemotactic inductive activity compared to control samples. Additionally, reactivity to BA4 was significantly increased. Similar statistically significant increases were identified for the samples from patients with idiopathic thoracic aortic aneurysm. There was a significant correlation between the chemotactic index and BA4 reactivity, and the increases in chemotactic activity of extracts from Marfan patients could be inhibited by pretreatment with lactose, VGVAPG peptides, or BA4, which indicates the involvement of EBP in mediating the effects. Our results demonstrate that aortic extracts of patients with Marfan syndrome can elicit macrophage chemotaxis, similar to our previous study on aortic extracts of the mgR mouse model of Marfan syndrome (Guo et al., Circulation 2006; 114:1855-62). PMID:21647416

Fiber micro-architecture in the longitudinal-radial and circumferential-radial planes of ascending thoracic aortic aneurysm media

PubMed Central

Tsamis, Alkiviadis; Phillippi, Julie A.; Koch, Ryan G.; Pasta, Salvatore; D'Amore, Antonio; Watkins, Simon C.; Wagner, William R.; Gleason, Thomas G.; Vorp, David A.

2013-01-01

It was recently demonstrated by our group that the delamination strength of ascending thoracic aortic aneurysms (ATAA) was lower than that of control (CTRL, non-aneurysmal) ascending thoracic aorta (ATA), and the reduced strength was more pronounced among bicuspid (BAV) vs. tricuspid aortic valve (TAV) patients, suggesting a different risk of aortic dissection for BAV patients. We hypothesized that aortic valve morphologic phenotype predicts fiber micro-architectural anomalies in ATA. To test the hypothesis, we characterized the micro-architecture in the longitudinal-radial (Z-RAD) and circumferential-radial (Θ-RAD) planes of human ATA tissue that was artificially dissected medially. The outer and inner-media of CTRL-ATA, BAV-ATAA and TAV-ATAA were imaged using multi-photon microscopy in the Z-RAD and Θ-RAD planes to observe collagen and elastin. Micrographs were processed using an image-based tool to quantify several micro-architectural characteristics. In the outer-media of BAV-ATAA, elastin was more undulated and less aligned about the Θ-axis when compared with CTRL-ATA, which is consistent with increased tensile stretch at inflection point of Θ-strips of adventitial-medial half of BAV-ATAA (1.28) when compared with CTRL-ATA (1.13). With increasing age, collagen became more undulated about the Z-axis within the outer-media of TAV-ATAA, and elastin became more oriented in the Z-axis and collagen less radially-oriented within the inner-media of TAV-ATAA. This discrepancy in the micro-architecture with fibers in the inner layers being more stretched and with disrupted radially-oriented components than fibers in the outer layers may be associated with the development, progression and vascular remodeling in aneurysms arising in TAV patients. PMID:24075403

Characterization of mechanical properties of lamellar structure of the aortic wall: Effect of aging.

PubMed

Taghizadeh, Hadi; Tafazzoli-Shadpour, Mohammad

2017-01-01

Arterial wall tissues are sensitive to their mechanical surroundings and remodel their structure and mechanical properties when subjected to mechanical stimuli such as increased arterial pressure. Such remodeling is evident in hypertension and aging. Aging is characterized by stiffening of the artery wall which is assigned to disturbed elastin function and increased collagen content. To better understand and provide new insight on microstructural changes induced by aging, the lamellar model of the aortic media was utilized to characterize and compare wall structure and mechanical behavior of the young and old human thoracic aortic samples. Such model regards arterial media as two sets of alternating concentric layers, namely sheets of elastin and interlamellar layers. Histological and biaxial tests were performed and microstructural features and stress-strain curves of media were evaluated in young and old age groups. Then using optimization algorithms and hyperelastic constitutive equations the stress-strain curves of layers were evaluated for both age groups. Results indicated slight elevation in the volume fraction of interlamellar layer among old subjects most probably due to age related collagen deposition. Aging indicated substantial stiffening of interlamellar layers accompanied by noticeable softening of elastic lamellae. The general significant stiffening of old samples were attributed to both increase of volume fraction of interlamellar layers and earlier recruitment of collagen fibers during load bearing due to functional loss of elastin within wall lamellae. Mechanical characterization of lamellar structure of wall media is beneficial in study of arterial remodeling in response to alternated mechanical environment in aging and clinical conditions through coupling of wall microstructure and mechanical behavior. Copyright © 2016 Elsevier Ltd. All rights reserved.

The impact of knowledge transfer on the detection of venous invasion in colorectal cancer.

PubMed

Kirsch, Richard; Assarzadegan, Naziheh; Messenger, David E; Juda, Ari; Riddell, Robert H; Pollett, Aaron; Streutker, Catherine J; Divaris, Dimitrios X; Newell, Ken J; Price, Russell G; Smith, Sharyn; Al-Haddad, Sahar; Parfitt, Jeremy R; Driman, David K

2017-09-01

Venous invasion (VI) is an independent predictor of hematogenous metastasis and mortality in colorectal cancer (CRC) yet remains widely underreported. Its detection may require recognition of subtle morphologic clues, which at times are only unmasked with an elastin stain. This study evaluates the impact of a knowledge transfer initiative (KTI) on VI detection in a "real-world" pathology practice setting. Following participation in an interobserver variability study of VI detection (Kirsch et al, 2013), 12 participants received educational materials highlighting key issues in VI detection. Eighteen months later, participants were invited to submit pathology reports from all CRC resections signed out 18 months prior to and 18 months following the KTI (n = 266 and n = 244, respectively). Nine pathologists participated. Reports were reviewed for VI and other established prognostic factors. Numbers of elastin stains and tumor-containing blocks were also recorded. Comparative analyses were adjusted for baseline differences in tumor, lymph node, and metastasis stage; tumor location; use of neoadjuvant therapy; and number of tumor-containing blocks. VI detection increased significantly post-KTI versus pre-KTI (39.3% versus 18.4%, adjusted odds ratio [OR] 2.86 [1.91-4.28], P < .001). Increased VI detection post-KTI was observed in both stage II (31.8% versus 12.5%, adjusted OR 3.27 [1.45-7.42], P = .004) and stage III CRC (62.4% versus 28.2%, adjusted OR 4.23 [2.37-7.55], P < .001). All pathologists demonstrated increased VI detection post-KTI. Use of elastin stains was significantly higher post-KTI versus pre-KTI (61.5% versus 5.3% of cases respectively, P < .001). This study demonstrates the effectiveness of knowledge transfer in increasing VI detection in routine pathology practice. Copyright © 2017 Elsevier Inc. All rights reserved.

First delivery and ovariectomy affect biomechanical and structural properties of the vagina in the ovine model.

PubMed

Urbankova, Iva; Callewaert, Geertje; Blacher, Silvia; Deprest, Dries; Hympanova, Lucie; Feola, Andrew; De Landsheere, Laurent; Deprest, Jan

2018-01-08

Animal models are useful for investigating the genesis of pelvic floor dysfunction and for developing novel therapies for its treatment. There is a need for an alternative large-animal model to the nonhuman primate. Therefore we studied the effects of the first vaginal delivery, ovariectomy and systemic hormonal replacement therapy (HRT) on the biomechanical and structural properties of the ovine vagina. We examined the gross anatomical properties of nulliparous, primiparous, ovariectomized multiparous, and ovariectomized hormone-replaced multiparous sheep (six animals per group). We also harvested mid-vaginal and distal vaginal tissue to determine smooth muscle contractility and passive biomechanical properties, for morphometric assessment of the vaginal wall layers, to determine collagen and elastin content, and for immunostaining for α-smooth muscle actin and estrogen receptor-α. There were no regional differences in the nulliparous vagina. One year after the first vaginal delivery, stiffness and contractility of the distal vagina were decreased, whereas the elastin content increased. The mid-vagina of ovariectomized sheep was stiff, and its epithelium was thin and lacked glycogen. HRT decreased the stiffness of the mid-vagina by 45% but had no measurable effect on contractility or elastin content, and increased epithelial thickness and glycogen content. HRT also increased the epithelial thickness and glycogen content of the distal vagina. At this location, there were no changes in morphology or stiffness. In sheep, life events including delivery and ovariectomy affect the biomechanical properties of the vagina in a region-specific way. Vaginal delivery mainly affects the distal region by decreasing stiffness and contractility. HRT can reverse the increase in stiffness of the mid-vagina observed after surgical induction of menopause. These observations are in line with scanty biomechanical measurements in comparable clinical specimens.

Fiber micro-architecture in the longitudinal-radial and circumferential-radial planes of ascending thoracic aortic aneurysm media.

PubMed

Tsamis, Alkiviadis; Phillippi, Julie A; Koch, Ryan G; Pasta, Salvatore; D'Amore, Antonio; Watkins, Simon C; Wagner, William R; Gleason, Thomas G; Vorp, David A

2013-11-15

It was recently demonstrated by our group that the delamination strength of ascending thoracic aortic aneurysms (ATAA) was lower than that of control (CTRL, non-aneurysmal) ascending thoracic aorta (ATA), and the reduced strength was more pronounced among bicuspid (BAV) vs. tricuspid aortic valve (TAV) patients, suggesting a different risk of aortic dissection for BAV patients. We hypothesized that aortic valve morphologic phenotype predicts fiber micro-architectural anomalies in ATA. To test the hypothesis, we characterized the micro-architecture in the longitudinal-radial (Z-RAD) and circumferential-radial (Θ-RAD) planes of human ATA tissue that was artificially dissected medially. The outer and inner-media of CTRL-ATA, BAV-ATAA and TAV-ATAA were imaged using multi-photon microscopy in the Z-RAD and Θ-RAD planes to observe collagen and elastin. Micrographs were processed using an image-based tool to quantify several micro-architectural characteristics. In the outer-media of BAV-ATAA, elastin was more undulated and less aligned about the Θ-axis when compared with CTRL-ATA, which is consistent with increased tensile stretch at inflection point of Θ-strips of adventitial-medial half of BAV-ATAA (1.28) when compared with CTRL-ATA (1.13). With increasing age, collagen became more undulated about the Z-axis within the outer-media of TAV-ATAA, and elastin became more oriented in the Z-axis and collagen less radially-oriented within the inner-media of TAV-ATAA. This discrepancy in the micro-architecture with fibers in the inner layers being more stretched and with disrupted radially-oriented components than fibers in the outer layers may be associated with the development, progression and vascular remodeling in aneurysms arising in TAV patients. © 2013 Elsevier Ltd. All rights reserved.