Science.gov

Sample records for collagen induced ear

  1. Prostaglandins in the perilymph of guinea pig with type II collagen induced ear diseases

    SciTech Connect

    Takeda, T.; Chiang, T.; Kitano, H.; Sudo, N.; Kim, S.Y.; Ha, S.; Woo, V.; Wolf, B.; Floyd, R.; Yoo, T.J.

    1986-03-01

    The authors have studied the prostaglandins (PGs) in the perilymph from guinea pig with type II collagen induced autoimmune ear disease. Hartly guinea pigs were immunized with type II collagen in CFA and auditory brain stem responses (ABR) were measured at 2, 3, 4, and 6 months after initial immunization perilymph was obtained and the levels of PGE2 and 6 keto-PGFl..cap alpha.. were measured by radioimmunoassays. Temporal bones were examined for the histopathologic changes. Immunized guinea pigs showed the evidence of hearing loss by ABR. The temporal bones showed the following changes: spiral ganglia degeneration, mild to moderate degree of degeneration in organ of Corti, infrequent very mild endolymphatic hydrops and labrynthitis. The perilymph from immunized animals contained about 5 times more PGE2 and about 3 times more 6 keto-PGFl..cap alpha.. than control animals. However, between these two groups, there was no difference in the CSF and sera levels of PGE2 and 6 keto-PGFl..cap alpha... Thus, this study suggests that these inflammatory mediators might be involved in the pathogenesis of collagen induced autoimmune inner ear disease.

  2. Profile of capsaicin-induced mouse ear oedema as neurogenic inflammatory model: comparison with arachidonic acid-induced ear oedema.

    PubMed Central

    Inoue, H.; Nagata, N.; Koshihara, Y.

    1993-01-01

    1. We have investigated the mechanism of capsaicin-induced mouse ear oedema compared with that of arachidonic acid (AA)-induced ear oedema, and evaluated the possible involvement of neuropeptides in the development of capsaicin-induced oedema. 2. Topical application of capsaicin (0.1-1.0 mg per ear) to the ear of mice produced immediate vasodilatation and erythema followed by the development of oedema which was maximal at 30 min after the treatment. This oedema was of shorter duration with less swelling than AA-induced oedema (2.0 mg per ear). 3. Capsaicin-induced ear oedema was unaffected when inhibitors of arachidonate metabolites including platelet activating factor (PAF) were administered before capsaicin (250 micrograms per ear) application, while these agents significantly prevented AA-induced oedema. Dexamethasone, histamine H1 and/or 5-hydroxytryptamine (5-HT) antagonists, and substance P (SP) antagonists were effective in inhibiting both models. Furthermore, a Ca(2+)-channel blocker and the capsaicin inhibitor, ruthenium red, were effective inhibitors of capsaicin oedema but had no effect on AA-induced oedema. 4. Phosphoramidon (50 micrograms kg-1, i.v.), an endopeptidase inhibitor, markedly (P < 0.001) enhanced only capsaicin-induced ear oedema, but bestatin (0.5 mg kg-1, i.v.), an aminopeptidase, failed to enhance oedema formation. 5. Neuropeptides (1-100 pmol per site) such as rat calcitonin gene-related peptide (CGRP), SP, neurokinin A (NKA), and vasoactive intestinal peptide (VIP), which are released from capsaicin-sensitive neurones, caused ear oedema by intradermal injection. Furthermore, a synergistic effect of CGRP (10 fmol per site) and SP (10pmol per site) on oedema formation was observed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7508328

  3. Protective effect of small molecule analogues of the Acanthocheilonema viteae secreted product ES-62 on oxazolone-induced ear inflammation

    PubMed Central

    Al-Riyami, Lamyaa; Rodgers, David T.; Rzepecka, Justyna; Pineda, Miguel A.; Suckling, Colin J.; Harnett, Margaret M.; Harnett, William

    2015-01-01

    ES-62 is the major secreted protein of the rodent filarial nematode Acanthocheilonema viteae. The molecule contains covalently attached phosphorylcholine (PC) residues, which confer anti-inflammatory properties on ES-62, underpinning the idea that drugs based on this active moiety may have therapeutic potential in human diseases associated with aberrant inflammation. Here we demonstrate that two synthetic small molecule analogues (SMAs) of ES-62 termed SMA 11a and SMA 12b are protective in the oxazolone-induced acute allergic contact dermatitis mouse model of skin inflammation, as measured by a significant reduction in ear inflammation following their administration before oxazolone sensitisation and before oxazolone challenge. Furthermore, it was found that when tested, 12b was effective at reducing ear swelling even when first administered before challenge. Histological analysis of the ears showed elevated cellular infiltration and collagen deposition in oxazolone-treated mice both of which were reduced by treatment with the two SMAs. Likewise, the oxazolone-induced increase in IFNγ mRNA in the ears was reduced but no effect on other cytokines investigated was observed. Finally, no influence on the mast cell populations in the ear was observed. PMID:25836375

  4. Lack of Collagen VI Promotes Wound-Induced Hair Growth.

    PubMed

    Chen, Peiwen; Cescon, Matilde; Bonaldo, Paolo

    2015-10-01

    Collagen VI is an extracellular matrix molecule that is abundantly expressed in the skin. However, the role of collagen VI in hair follicle growth is unknown. Here, we show that collagen VI is strongly deposited in hair follicles, and is markedly upregulated by skin wounding. Lack of collagen VI in Col6a1(-/-) mice delays hair cycling and growth under physiological conditions, but promotes wound-induced hair regrowth without affecting skin regeneration. Conversely, addition of purified collagen VI rescues the abnormal wound-induced hair regrowth in Col6a1(-/-) mice. Mechanistic studies revealed that the increased wound-induced hair regrowth of Col6a1(-/-) mice is triggered by activation of the Wnt/β-catenin signaling pathway, and is abolished by inhibition of this pathway. These findings highlight the essential relationships between extracellular matrix (ECM) and hair follicle regeneration, and suggest that collagen VI could be a potential therapeutic target for hair loss and other skin-related diseases. PMID:25989472

  5. Aza-Glycine Induces Collagen Hyperstability.

    PubMed

    Zhang, Yitao; Malamakal, Roy M; Chenoweth, David M

    2015-10-01

    Hydrogen bonding is fundamental to life on our planet, and nature utilizes H-bonding in nearly all biomolecular interactions. Often, H-bonding is already maximized in natural biopolymer systems such as nucleic acids, where Watson-Crick H-bonds are fully paired in double-helical structures. Synthetic chemistry allows molecular editing of biopolymers beyond nature's capability. Here we demonstrate that substitution of glycine (Gly) with aza-glycine in collagen may increase the number of interfacial cross-strand H-bonds, leading to hyperstability in the triple-helical form. Gly is the only amino acid that has remained intolerant to substitution in collagen. Our results highlight the vital importance of maximizing H-bonding in higher order biopolymer systems using minimally perturbing alternatives to nature's building blocks. PMID:26368649

  6. Collagen-induced thrombosis in murine arteries and veins.

    PubMed

    Cooley, Brian C

    2013-01-01

    Collagen is a powerful thrombotic stimulus that functions by direct and indirect binding to various platelet receptors. A variety of collagen types are known and several (e.g., collagen Types I, III, IV) are found in vascular tissues and are exposed upon disruption of the endothelium or more extensive vessel wall rupture. Some murine models of thrombosis purport to expose collagen to initiate thrombosis, however, the nature and extent of this exposure is not clear. This study was undertaken to place a known collagen-dominated surface into the in vivo arterial or venous circulation as a method for direct study of collagen-induced thrombosis in mice. The epigastric artery was removed from donor mice and a microsuture with attached needle was knotted into one cut end. Anesthetized mice had this needle/suture/small-artery inserted into and out of a 0.5-mm length of the larger carotid artery or femoral vein, leaving the collagen-rich adventitial surface of the epigastric artery intralumenally in the larger vessel. Extensive platelet and fibrin deposition on this surface were in evidence and were quantitated with fluorescence imaging; administration of clopidogrel reduced thrombus development in both arteries and veins. A method was developed to evert the epigastric artery and disrupt the exteriorized endothelium; with the same needle/suture vessel-insertion technique, this surface stimulated significantly less thrombotic response in both arteries and veins, suggesting differential thrombogenesis based on the molecular composition of the induction factor. This new model of thrombosis offers a method for directly assessing the role of collagen-mediated thrombosis in murine arteries and veins. PMID:23063056

  7. Skin pathology induced by snake venom metalloproteinase: acute damage, revascularization, and re-epithelization in a mouse ear model.

    PubMed

    Jiménez, Natalia; Escalante, Teresa; Gutiérrez, José María; Rucavado, Alexandra

    2008-10-01

    Viperid snakebite envenomation induces blistering and dermonecrosis. The pathological alterations induced by a snake venom metalloproteinase in the skin were investigated in a mouse ear model. Metalloproteinase BaP1, from Bothrops asper, induced rapid edema, hemorrhage, and blistering; the latter two effects were abrogated by preincubation with the metalloproteinase inhibitor batimastat. Neutrophils did not play a role in the pathology, as depletion of these cells resulted in a similar histological picture. Blisters are likely to result from the direct proteolytic activity of BaP1 of proteins at the dermal-epidermal junction, probably at the lamina lucida, as revealed by immunostaining for type IV collagen and laminin. Widespread apoptosis of keratinocytes was detected by the TUNEL assay, whereas no apoptosis of capillary endothelial cells was observed. BaP1 induced a drastic reduction in the microvessel density, revealed by immunostaining for the endothelial marker vascular endothelial growth factor receptor-2. This was followed by a rapid angiogenic response, leading to a partial revascularization. Skin damage was followed by inflammation and granulation tissue formation. Then, a successful re-epithelization process occurred, and the skin of the ear regained its normal structure by 2 weeks. Venom metalloproteinase-induced skin damage reproduces the pathological changes described in snakebitten patients. PMID:18449209

  8. Modulation by glycyrrhetinic acid derivatives of TPA-induced mouse ear oedema.

    PubMed Central

    Inoue, H.; Mori, T.; Shibata, S.; Koshihara, Y.

    1989-01-01

    1. The anti-inflammatory effects of glycyrrhetinic acid and its derivatives on TPA (12-O-tetradecanoylphorbol-13-acetate)-induced mouse ear oedema were studied. The mechanisms of TPA-induced ear oedema were first investigated with respect to the chemical mediators. 2. The formation of ear oedema reached a maximum 5 h after TPA application (2 micrograms per ear) and the prostaglandin E2 (PGE2) production of mouse ear increased with the oedema formation. 3. TPA-induced ear oedema was prevented by actinomycin D and cycloheximide (0.1 mg per ear, respectively) when applied during 60 min after TPA treatment. 4. Of glycyrrhetinic acid derivatives examined, dihemiphthalate derivatives (IIe, IIe', IIIa, IIIa', IVa, IVa') most strongly inhibited ear oedema on both topical (ID50, 1.6 mg per ear for IIe, 2.0 mg per ear for IIIa and 1.6 mg per ear for IVa) and oral (ID50, 88 mg kg-1 for IIe', 130 mg kg-1 for IIIa' and 92 mg kg-1 for IVa') administration. 5. Glycyrrhetinic acid (Ia) and its derivatives applied 30 min before TPA treatment were much more effective in inhibiting oedema than when applied 30 min after TPA. A dihemiphthalate of triterpenoid compound IVa completely inhibited oedema, even when applied 3 h before TPA treatment. 6. Glycyrrhetinic acid (Ia) and deoxoglycyrrhetol (IIa), the parent compounds, produced little inhibition by oral administration at less than 200 mg kg-1. 7. These results suggest that the dihemiphthalate derivatives of triterpenes derived from glycyrrhetinic acid by chemical modification are useful for the treatment of skin inflammation by both topical and oral application. PMID:2924072

  9. Characteristics of laser-induced shock wave injury to the inner ear of rats

    NASA Astrophysics Data System (ADS)

    Kurioka, Takaomi; Matsunobu, Takeshi; Niwa, Katsuki; Tamura, Atsushi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro

    2014-12-01

    Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury.

  10. Characteristics of laser-induced shock wave injury to the inner ear of rats.

    PubMed

    Kurioka, Takaomi; Matsunobu, Takeshi; Niwa, Katsuki; Tamura, Atsushi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro

    2014-12-01

    Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury. PMID:25467523

  11. Inorganic pyrophosphatase induces type I collagen in osteoblasts

    PubMed Central

    Polewski, Monika D.; Johnson, Kristen A.; Foster, Melissa; Millán, José Luis; Terkeltaub, Robert

    2009-01-01

    Introduction The physiologic selectivity of calcification in bone tissue reflects selective co-expression by osteoblasts of fibrillar collagen I and of tissue nonspecific alkaline phosphatase (TNAP), which hydrolyzes the calcification inhibitor pyrophosphate (PPi) and generates phosphate (Pi). Humans and mice deficient in the PPi-generating ecto-enzyme NPP1 demonstrate soft tissue calcification, occurring at sites of extracellular matrix expansion. Significantly, the function in osteoblasts of cytosolic inorganic pyrophosphatase (abbreviated iPPiase), which generates Pi via PPi hydrolysis with neutral pH optimum, remains unknown. We assessed iPPiase in Enpp1−/− and wild type (WT) mouse osteoblasts and we tested the hypothesis that iPPiase regulates collagen I expression. Methods We treated mouse calvarial osteoblasts with ascorbate and β-glycerol phosphate to promote calcification, and we assessed cytosolic Pi and PPi levels, sodium-dependent Pi uptake, Pit-1 Pi co-transporter expression, and iPPiase and TNAP activity and expression. We also assessed the function of transfected Ppa1 in osteoblasts. Results Inorganic pyrophosphatase but not TNAP was elevated in Enpp1−/− calvariae in situ. Cultured primary Enpp1−/− calvarial osteoblasts demonstrated increased calcification despite flat TNAP activity rather than physiologic TNAP up-regulation seen in WT osteoblasts. Despite decreased cytosolic PPi in early culture, Enpp1−/− osteoblasts maintained cytosolic Pi levels comparable to WT osteoblasts, in association with increased iPPiase, enhanced sodium-dependent Pi uptake and expression of Pit-1, and markedly increased collagen I synthesis. Suppression of collagen synthesis in Enpp1−/− osteoblasts using 3,4-dehydroproline markedly suppressed calcification. Last, transfection of Ppa1 in WT osteoblasts increased cytosolic Pi and decreased cytosolic but not extracellular PPi, and induced both collagen I synthesis and calcification. Conclusions Increased

  12. Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy.

    PubMed

    Hovhannisyan, V; Guo, H W; Hovhannisyan, A; Ghukasyan, V; Buryakina, T; Chen, Y F; Dong, C Y

    2014-05-01

    Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the natural pigment hypericin induces photosensitized destruction of collagen-based tissues. We demonstrate that hypericin-mediated processes in collagen fibers are irreversible and may be used for the treatment of cancer and collagen-related disorders. PMID:24877000

  13. Arthritis in mice induced by a single immunisation with collagen.

    PubMed Central

    Kato, F; Nomura, M; Nakamura, K

    1996-01-01

    OBJECTIVE: To determine whether collagen induced arthritis (CIA) in mice can be satisfactorily induced by a single immunisation and whether this model has some advantages compared with conventional CIA, which is induced by two immunisations. METHODS: The incidence of arthritis was observed under different immunisation conditions (variation of species of Mycobacterium included in complete Freund's adjuvant and the method of emulsification) and immunological, histopathological, and pharmacological features were examined. RESULTS: Under optimum immunisation conditions, joint inflammation developed two to three weeks after the primary immunisation with an incidence of 100% at four to five weeks. The progression of the arthritis was mild and was associated with moderate increases in concentrations of serum IgG against type II collagen. This CIA model was similar to the conventional model in histopathological and pharmacological features. CONCLUSIONS: Murine CIA could be successfully induced by a single immunisation. An important feature of this model was a mild progression of joint inflammation. This feature seems to be of benefit for monitoring the development of arthritis from an early stage in the disease and for the development of novel antirheumatic drugs for such early stage patients. Images PMID:8774181

  14. Sirt2 suppresses inflammatory responses in collagen-induced arthritis

    SciTech Connect

    Lin, Jiangtao; Sun, Bing; Jiang, Chuanqiang; Hong, Huanyu; Zheng, Yanping

    2013-11-29

    Highlights: •Sirt2 expression decreases in collagen-induced arthritis (CIA). •Sirt2 knockout aggravates severity of arthritis in mice with CIA. •Sirt2 knockout increases levels of pro-inflammatory factors in the serum. •Sirt2 deacetylates p65 and inhibits pro-inflammatory factors expression. •Sirt2 rescue abates severity of arthritis in mice with CIA. -- Abstract: Arthritis is a common autoimmune disease that is associated with progressive disability, systemic complications and early death. However, the underling mechanisms of arthritis are still unclear. Sirtuins are a NAD{sup +}-dependent class III deacetylase family, and regulate cellular stress, inflammation, genomic stability, carcinogenesis, and energy metabolism. Among the sirtuin family members, Sirt1 and Sirt6 are critically involved in the development of arthritis. It remains unknown whether other sirtuin family members participate in arthritis. Here in this study, we demonstrate that Sirt2 inhibits collagen-induced arthritis (CIA) using in vivo and in vitro evidence. The protein and mRNA levels of Sirt2 significantly decreased in joint tissues of mice with CIA. When immunized with collagen, Sirt2-KO mice showed aggravated severity of arthritis based on clinical scores, hind paw thickness, and radiological and molecular findings. Mechanically, Sirt2 deacetylated p65 subunit of nuclear factor-kappa B (NF-κB) at lysine 310, resulting in reduced expression of NF-κB-dependent genes, including interleukin 1β (IL-1β), IL-6, monocyte chemoattractant protein 1(MCP-1), RANTES, matrix metalloproteinase 9 (MMP-9) and MMP-13. Importantly, our rescue experiment showed that Sirt2 re-expression abated the severity of arthritis in Sirt2-KO mice. Those findings strongly indicate Sirt2 as a considerably inhibitor of the development of arthritis.

  15. Assessment of thermal treatment via irrigation of external ear to reduce cisplatin-induced hearing loss.

    PubMed

    Spankovich, Christopher; Lobarinas, Edward; Ding, Dalian; Salvi, Richard; Le Prell, Colleen G

    2016-02-01

    Systemic and local changes in body temperature can have a profound effect on traumatic injuries including those to the inner ear. Therefore, we investigated the effects of acutely increasing or decreasing the temperature of the external ear canal on cisplatin-induced hearing loss. The external auditory canals of male guinea pigs were acutely irrigated with warm (44 °C), euthermic (37 °C), or cool (30 °C) water and subsequently injected with cisplatin (12 mg/kg, i.p.). Hearing was assessed by the auditory brainstem response and cochleograms were prepared to determine loss of hair cells. Ear canal irrigation with warm water potentiated cisplatin-induced hearing loss and outer hair cell loss whereas cool ear canal irrigation showed significant protection from cisplatin-induced hearing loss and outer hair cell loss. These results suggest that non-invasive cool water ear canal irrigation may be highly effective clinical procedure for protecting against cisplatin-induced hearing loss. PMID:26639015

  16. Suppression of collagen induced arthritis by idiotype coupled lymphoid cells

    SciTech Connect

    Nagler-Anderson, C.; Gurish, M.F.; Robinson, M.E.; Thorbecke, G.J.

    1986-03-01

    Studies were initiated to evaluate the regulatory influence of idiotype (Id) networks in an experimental auto-immune disease. Collagen induced arthritis is an animal model of polyarthritis induced in susceptible mice by immunization with collagen II (CII). A humoral immune response to CII appears to be critical for the development of diseases. If subpopulations of the anti-CII abs, important for the induction of arthritis, could be identified and manipulated through the presence of a major Id, it should be possible to decrease arthritis incidence by suppressing the production of these Ids. Specifically purified anti-CII abs from arthritic DBA/1 mice were coupled to syngeneic spleen cells and administered IV prior to intradermal immunization with CII. By day 34 after 1/sup 0/ immunization, 100% of control mice and 50% of treated mice had developed arthritis. Suppression of the Id population administered to the treated group was confirmed by RIA. Sera from individual mice were tested as inhibitors of binding of /sup 125/I-labelled polyclonal DBA/1 anti-CII to a rabbit anti-Id directed against polyclonal anti-CII isolated from the sera of arthritic mice. Mean percentage of inhibition of binding of /sup 125/I-Id to rabbit anti-Id by sera from non-arthritic treated mice was found to be significantly lower than that observed in the arthritic control group (p = .045), but did not correlate with total anti-CII ab titers.

  17. Development of biomimetic tilapia collagen nanofibers for skin regeneration through inducing keratinocytes differentiation and collagen synthesis of dermal fibroblasts.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2015-02-11

    In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides, and its denaturation temperature was 44.99 °C. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4+/CD8+ lymphocytes, and the level of IgG or IgM in Sprague-Dawley rat. The contact angle, tensile strength, and weight loss temperature of collagen nanofibers were 21.2°, 6.72±0.44 MPa, and 300 °C, respectively. The nanofibers could promote the viabilities of human keratinocytes (HaCaTs) and human dermal fibroblasts (HDFs), inducing epidermal differentiation through the gene expression of involucrin, filaggrin, and type I transglutaminase of HaCaTs, and they could also accelerate migration of HaCaTs with the expression of matrix metalloproteinase-9 and transforming growth factor-β1 (TGF-β1). Besides, the nanofibers could upregulate the protien level of Col-I in HDFs both via a direct effect and TGF-β1 secreted from HaCaTs, thus facilitating the formation of collagen fibers. Furthermore, the collagen nanofibers stimulated the skin regeneration rapidly and effectively in vivo. These biological effects could be explained as the contributions from the biomimic extracellular cell matrix structure, hydrophilicity, and the multiple amino acids of the collagen nanofibers. PMID:25598076

  18. Immune regulation and anti-inflammatory effects of isogarcinol extracted from Garcinia mangostana L. against collagen-induced arthritis.

    PubMed

    Fu, Yanxia; Zhou, Hailing; Wang, Mengqi; Cen, Juren; Wei, Qun

    2014-05-01

    Isogarcinol is a natural compound that we extracted from Garcinia mangostana L., and we were the first to report that it is a new immunosuppressant. In the present study, we investigated the immune regulation and anti-inflammatory effects of isogarcinol on collagen-induced arthritis (CIA) and explored its potential mechanism in the treatment of rheumatoid arthritis. The oral administration of isogarcinol significantly reduced clinical scores, alleviated cartilage and bone erosion, and reduced the levels of serum inflammatory cytokines in CIA mice. Isogarcinol inhibited xylene-induced mouse ear edema in vivo. In vitro, isogarcinol decreased iNOS and COX-2 mRNA expression and NO content by inhibiting NF-κB expression. Furthermore, isogarcinol decreased the activity of NFAT and inhibited IL-2 expression. The mechanism of action of isogarcinol is associated with down-regulation of both autoimmune and inflammatory reactions. PMID:24738849

  19. Cantharidin-induced inflammation in mouse ear model for translational research of novel anti-inflammatories.

    PubMed

    Ivetic Tkalcevic, Vanesa; Hrvacic, Boska; Bosnar, Martina; Cuzic, Snjezana; Bosnjak, Berislav; Erakovic Haber, Vesna; Glojnaric, Ines

    2012-08-01

    The murine model of cantharidin-induced ear inflammation was profiled in detail for its alignment with the human model and to explore the mechanism of anti-inflammatory activity of the macrolide antibiotics, clarithromycin and azithromycin. Ear swelling in CD1 mice persisted for 7 days, with peak intensity at 16 h after inflammation induction. As in humans, cantharidin (12.5 μg/ear) generated macrophage-inflammatory protein (MIP)-2, monocyte chemoattractant protein (MCP)-1, keratinocyte-derived chemokine (KC), interleukin (IL)-6, IL-1β, and myeloperoxidase (MPO) production, as well as neutrophil accumulation in mouse ear tissue. The tested macrolides, clarithromycin and azithromycin, administered orally (2 × 150 mg/kg) 0.5 h before and 5 h after cantharidin challenge, reduced MIP-2, MCP-1, KC, and MPO concentrations and thereby decreased ear swelling. Our results suggest that cantharidin-induced acute inflammation represents an excellent model for translational research of novel anti-inflammatories. PMID:22677362

  20. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    SciTech Connect

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  1. Protective effects of papaverine salicylate in mouse ear dermatitis and PAF-induced rat paw oedema.

    PubMed

    de Bernardis, E; Leonardi, G; Caruso, A; Cutuli, V M; Amico-Roxas, M

    1994-08-01

    Papaverine salicylate (MR-800) has been tested as a topical antiinflammatory agent in several models of skin inflammation in rodents, such as mouse ear dermatitis induced by croton oil, cantharidin or zymosan, and rat paw oedema induced by PAF. MR-800 exerted a dose-dependent inhibitory activity in all assays, when equimolar doses of sodium salicylate or papaverine were less effective, suggesting the existence of a favourable synergism between salicylate and papaverine. PMID:7847181

  2. Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

    SciTech Connect

    Yano, Hiroyuki; Hamanaka, Ryoji; Nakamura, Miki; Sumiyoshi, Hideaki; Matsuo, Noritaka; Yoshioka, Hidekatsu

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer We examine how radiation affects the expression level and signal pathway of collagen. Black-Right-Pointing-Pointer TGF-{beta}1 mRNA is elevated earlier than those of collagen genes after irradiation. Black-Right-Pointing-Pointer Smad pathway mediates the expression of collagen in radiation induced fibrosis. Black-Right-Pointing-Pointer MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both {alpha}1and {alpha}2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-{beta}1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-{beta} receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of {alpha}2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

  3. Pathophysiology of the inner ear after blast injury caused by laser-induced shock wave

    PubMed Central

    Niwa, Katsuki; Mizutari, Kunio; Matsui, Toshiyasu; Kurioka, Takaomi; Matsunobu, Takeshi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro; Kobayashi, Yasushi

    2016-01-01

    The ear is the organ that is most sensitive to blast overpressure, and ear damage is most frequently seen after blast exposure. Blast overpressure to the ear results in sensorineural hearing loss, which is untreatable and is often associated with a decline in the quality of life. In this study, we used a rat model to demonstrate the pathophysiological and structural changes in the inner ear that replicate pure sensorineural hearing loss associated with blast injury using laser-induced shock wave (LISW) without any conductive hearing loss. Our results indicate that threshold elevation of the auditory brainstem response (ABR) after blast exposure was primarily caused by outer hair cell dysfunction induced by stereociliary bundle disruption. The bundle disruption pattern was unique; disturbed stereocilia were mostly observed in the outermost row, whereas those in the inner and middle rows stereocilia remained intact. In addition, the ABR examination showed a reduction in wave I amplitude without elevation of the threshold in the lower energy exposure group. This phenomenon was caused by loss of the synaptic ribbon. This type of hearing dysfunction has recently been described as hidden hearing loss caused by cochlear neuropathy, which is associated with tinnitus or hyperacusis. PMID:27531021

  4. Pathophysiology of the inner ear after blast injury caused by laser-induced shock wave.

    PubMed

    Niwa, Katsuki; Mizutari, Kunio; Matsui, Toshiyasu; Kurioka, Takaomi; Matsunobu, Takeshi; Kawauchi, Satoko; Satoh, Yasushi; Sato, Shunichi; Shiotani, Akihiro; Kobayashi, Yasushi

    2016-01-01

    The ear is the organ that is most sensitive to blast overpressure, and ear damage is most frequently seen after blast exposure. Blast overpressure to the ear results in sensorineural hearing loss, which is untreatable and is often associated with a decline in the quality of life. In this study, we used a rat model to demonstrate the pathophysiological and structural changes in the inner ear that replicate pure sensorineural hearing loss associated with blast injury using laser-induced shock wave (LISW) without any conductive hearing loss. Our results indicate that threshold elevation of the auditory brainstem response (ABR) after blast exposure was primarily caused by outer hair cell dysfunction induced by stereociliary bundle disruption. The bundle disruption pattern was unique; disturbed stereocilia were mostly observed in the outermost row, whereas those in the inner and middle rows stereocilia remained intact. In addition, the ABR examination showed a reduction in wave I amplitude without elevation of the threshold in the lower energy exposure group. This phenomenon was caused by loss of the synaptic ribbon. This type of hearing dysfunction has recently been described as hidden hearing loss caused by cochlear neuropathy, which is associated with tinnitus or hyperacusis. PMID:27531021

  5. Cell Alignment Driven by Mechanically Induced Collagen Fiber Alignment in Collagen/Alginate Coatings.

    PubMed

    Chaubaroux, Christophe; Perrin-Schmitt, Fabienne; Senger, Bernard; Vidal, Loïc; Voegel, Jean-Claude; Schaaf, Pierre; Haikel, Youssef; Boulmedais, Fouzia; Lavalle, Philippe; Hemmerlé, Joseph

    2015-09-01

    For many years it has been a major challenge to regenerate damaged tissues using synthetic or natural materials. To favor the healing processes after tendon, cornea, muscle, or brain injuries, aligned collagen-based architectures are of utmost interest. In this study, we define a novel aligned coating based on a collagen/alginate (COL/ALG) multilayer film. The coating exhibiting a nanofibrillar structure is cross-linked with genipin for stability in physiological conditions. By stretching COL/ALG-coated polydimethylsiloxane substrates, we developed a versatile method to align the collagen fibrils of the polymeric coating. Assays on cell morphology and alignment were performed to investigate the properties of these films. Microscopic assessments revealed that cells align with the stretched collagen fibrils of the coating. The degree of alignment is tuned by the stretching rate (i.e., the strain) of the COL/ALG-coated elastic substrate. Such coatings are of great interest for strategies that require aligned nanofibrillar biological material as a substrate for tissue engineering. PMID:25658028

  6. A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation

    PubMed Central

    Buonanno, M.; Randers-Pehrson, G.; Smilenov, L. B.; Kleiman, N. J.; Young, E.; Ponnayia, B.; Brenner, D. J.

    2015-01-01

    Radiation-induced bystander effects have been observed in vitro and in cell and tissue culture models, however, there are few reported studies showing these effects in vivo. To our knowledge, this is the first reported study on bystander effects induced by microbeam irradiation in an intact living mammal. The mouse ear was used to investigate radiation-induced bystander effects in keratinocytes, utilizing a 3 MeV proton microbeam (LET 13.1 keV/µm) with a range in skin of about 135 µm. Using a custom-designed holder, the ear of an anesthetized C57BL/6J mouse was flattened by gentle suction and placed over the microbeam port to irradiate cells along a 35 µm wide, 6 mm long path. Immunohistochemical analysis of γ-H2AX foci formation in tissue sections revealed, compared to control tissue, proton-induced γ-H2AX foci formation in one of the two epidermal layers of the mouse ear. Strikingly, a higher number of cells than expected showed foci from direct irradiation effects. Although the proton-irradiated line was ~35 µm wide, the average width spanned by γ-H2AX-positive cells exceeded 150 µm. Cells adjacent to or in the epidermal layer opposite the γ-H2AX-positive region did not exhibit foci. These findings validate this mammalian model as a viable system for investigating radiation-induced bystander effects in an intact living organism. PMID:26207682

  7. Heparin fragments modulate the collagen phenotype of fibroblasts from radiation-induced subcutaneous fibrosis

    SciTech Connect

    el Nabout, R.; Martin, M.; Remy, J.; Robert, L.; Lafuma, C. )

    1989-10-01

    Acute local gamma irradiation of porcine skin induces, as in human skin, an extensive and mutilating sclerosis characterized by continuous expansion of the fibrosis invading the adjacent muscle and by accumulation of the macromolecular components of the extracellular matrix. Collagen synthesis, content, and types were studied in the presence of heparin fragments (100 micrograms/10(6) cells) in the culture medium, by measuring the incorporation of the radiolabeled precursor (3H)proline into confluent primary cultures of porcine fibroblasts obtained from normal and irradiated fibrotic dermis. Enhancement in collagen biosynthesis and deposition and preferential increase in collagen type III synthesis were observed in fibrotic fibroblast cultures when compared to those in normal dermis fibroblasts. The total collagen synthesis and the rate of collagen hydroxylation appear unmodified by heparin fragments both in normal and in fibrotic fibroblast cultures. But heparin fragments induce a 10- and 2-fold decrease, respectively, in collagen type III and type V syntheses by fibrosis fibroblasts. As only minor effects upon collagen type III and V are observed in cultures of normal dermis fibroblasts, these results highly suggest that heparin fragments are capable of specifically modulating the collagen phenotype of fibroblasts derived from radiation-induced dermis fibrosis and thus are able to regulate the fibrotic process.

  8. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    SciTech Connect

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E. State Univ. of New York, Buffalo )

    1987-11-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of ({sup 3}H)serotonin, or alter the dose-responsive binding of {sup 125}I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF.

  9. Infection of corn ears by Fusarium spp. induces the emission of volatile sesquiterpenes.

    PubMed

    Becker, Eva-Maria; Herrfurth, Cornelia; Irmisch, Sandra; Köllner, Tobias G; Feussner, Ivo; Karlovsky, Petr; Splivallo, Richard

    2014-06-01

    Infection of corn (Zea mays L.) ears with fungal pathogens of the Fusarium genus might result in yield losses and in the accumulation of mycotoxins. The aim of this study was to investigate whether volatile profiles could be used to identify Fusarium-infected corn ears. The volatiles released by corn ears infected by Fusarium graminearum, Fusarium verticillioides, and Fusarium subglutinans were studied. Volatile emission was recorded at 24 days postinoculation (dpi) and in a time series (from 4 to 24 dpi). Twenty-two volatiles were differentially emitted from Fusarium-infected versus healthy corn ears. These included C6-C8 compounds and sesquiterpenoids. All volatiles indicative of Fusarium infection were detectable as early as 4-8 dpi and continued to be produced to the final sampling time (early milk maturity stage). The induced emission of β-macrocarpene and β-bisabolene correlated with an increased transcript accumulation of corn terpene synthase 6/11 (tps6/11). Additionally, the modification of volatile profiles after Fusarium infection was accompanied by the induction of plant defense compounds such as zealexins and oxylipins. Together, these results reveal a broad metabolic response of the plant to pathogen attack. Volatile biomarkers of Fusarium infection are promising indicators for the early detection of fungal infection before disease symptoms become visible. PMID:24816267

  10. Riboflavin-induced photo-crosslinking of collagen hydrogel and its application in meniscus tissue engineering.

    PubMed

    Heo, Jiseung; Koh, Rachel H; Shim, Whuisu; Kim, Hwan D; Yim, Hyun-Gu; Hwang, Nathaniel S

    2016-04-01

    A meniscus tear is a common knee injury, but its regeneration remains a clinical challenge. Recently, collagen-based scaffolds have been applied in meniscus tissue engineering. Despite its prevalence, application of natural collagen scaffold in clinical setting is limited due to its extremely low stiffness and rapid degradation. The purpose of the present study was to increase the mechanical properties and delay degradation rate of a collagen-based scaffold by photo-crosslinking using riboflavin (RF) and UV exposure. RF is a biocompatible vitamin B2 that showed minimal cytotoxicity compared to conventionally utilized photo-initiator. Furthermore, collagen photo-crosslinking with RF improved mechanical properties and delayed enzyme-triggered degradation of collagen scaffolds. RF-induced photo-crosslinked collagen scaffolds encapsulated with fibrochondrocytes resulted in reduced scaffold contraction and enhanced gene expression levels for the collagen II and aggrecan. Additionally, hyaluronic acid (HA) incorporation into photo-crosslinked collagen scaffold showed an increase in its retention. Based on these results, we demonstrate that photo-crosslinked collagen-HA hydrogels can be potentially applied in the scaffold-based meniscus tissue engineering. PMID:25809935

  11. Pierced Ears

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Pierced Ears KidsHealth > For Kids > Pierced Ears Print A A ... cool, but infected ears do not! Getting Your Ears Pierced It's important to get your ears pierced ...

  12. Osmotic pressure induced tensile forces in tendon collagen

    PubMed Central

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone. PMID:25608644

  13. Osmotic pressure induced tensile forces in tendon collagen

    NASA Astrophysics Data System (ADS)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  14. Nutrient-Enhanced Diet Reduces Noise-Induced Damage to the Inner Ear and Hearing Loss

    PubMed Central

    Le Prell, C. G.; Gagnon, P. M; Bennett, D. C.; Ohlemiller, K. K.

    2011-01-01

    Oxidative stress has been broadly implicated as a cause of cell death and neural degeneration in multiple disease conditions; however, the evidence for successful intervention with dietary antioxidant manipulations has been mixed. In this study, we investigated the potential for protection of cells in the inner ear using a dietary supplement with multiple antioxidant components, selected for their potential interactive effectiveness. Protection against permanent threshold shift (PTS) was observed in CBA/J mice maintained on a diet supplemented with a combination of β-carotene, vitamins C and E, and magnesium when compared to PTS in control mice maintained on a nutritionally complete control diet. Although hair cell survival was not enhanced, noise-induced loss of Type II fibrocytes in the lateral wall was significantly reduced (p<0.05), and there was a trend towards less noise-induced loss in strial cell density in animals maintained on the supplemented diet. Taken together, our data suggest that pre-noise oral treatment with the high-nutrient diet can protect cells in the inner ear and reduce PTS in mice. Demonstration of functional and morphological preservation of cells in the inner ear with oral administration of this antioxidant supplemented diet supports the possibility of translation to human patients, and suggests an opportunity to evaluate antioxidant protection in mouse models of oxidative stress-related disease and pathology. PMID:21708355

  15. Nutrient-enhanced diet reduces noise-induced damage to the inner ear and hearing loss.

    PubMed

    Le Prell, Colleen G; Gagnon, Patricia M; Bennett, David C; Ohlemiller, Kevin K

    2011-07-01

    Oxidative stress has been implicated broadly as a cause of cell death and neural degeneration in multiple disease conditions; however, the evidence for successful intervention with dietary antioxidant manipulations has been mixed. In this study, we investigated the potential for protection of cells in the inner ear using a dietary supplement with multiple antioxidant components, which were selected for their potential interactive effectiveness. Protection against permanent threshold shift (PTS) was observed in CBA/J mice maintained on a diet supplemented with a combination of β-carotene, vitamins C and E, and magnesium when compared with PTS in control mice maintained on a nutritionally complete control diet. Although hair cell survival was not enhanced, noise-induced loss of type II fibrocytes in the lateral wall was significantly reduced (P < 0.05), and there was a trend toward less noise-induced loss in strial cell density in animals maintained on the supplemented diet. Taken together, our data suggest that prenoise oral treatment with the high-nutrient diet can protect cells in the inner ear and reduce PTS in mice. The demonstration of functional and morphologic preservation of cells in the inner ear with oral administration of this antioxidant supplemented diet supports the possibility of translation to human patients and suggests an opportunity to evaluate antioxidant protection in mouse models of oxidative stress-related disease and pathology. PMID:21708355

  16. A histological evaluation for guided bone regeneration induced by a collagenous membrane.

    PubMed

    Taguchi, Yuya; Amizuka, Norio; Nakadate, Masayoshi; Ohnishi, Hideo; Fujii, Noritaka; Oda, Kimimitsu; Nomura, Shuichi; Maeda, Takeyasu

    2005-11-01

    This study was designed to evaluate the histological changes during ossification and cellular events including osteogenic differentiation responding to collagenous bioresorbable membranes utilized for GBR. Standardized artificial bony defects were prepared at rat maxillae, and covered with a collagenous bioresorbable membrane. These animals were sacrificed at 1, 2, 3 and 4 weeks after the GBR-operation. The paraffin sections were subject to tartrate resistant acid phosphatase (TRAP) enzyme histochemistry and immunohistochemistry for alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC). In the first week of the experimental group, woven bone with ALP-positive osteoblasts occupied the lower half of the cavity. The collagenous membrane included numerous ALP-negative cells and OP-immunoreactive extracellular matrices. At 2 weeks, the ALP-, OP- and OC-immunoreactivity came to be recognizable in the region of collagenous membrane. Since ALP-negative soft tissue separated the collagenous membrane and the new bone originating from the cavity bottom, the collagenous membrane appeared to induce osteogenesis in situ. At 3 weeks, numerous collagen fibers of the membrane were embedded in the adjacent bone matrix. At 4 weeks, the membrane-associated and the cavity-derived bones had completely integrated, showing the same height of the periosteal ridge as the surrounding alveolar bones. The collagen fibers of a GBR-membrane appear to participate in osteogenic differentiation. PMID:15885767

  17. Magnetically induced behaviour of ferritin corpuscles in avian ears: can cuticulosomes function as magnetosomes?

    PubMed Central

    Jandacka, Petr; Burda, Hynek; Pistora, Jaromir

    2015-01-01

    Magnetoreception is an enigmatic, poorly understood sensory ability, described mainly on the basis of behavioural studies in animals of diverse taxa. Recently, corpuscles containing superparamagnetic iron-storage protein ferritin were found in the inner ear hair cells of birds, a predominantly single ferritin corpuscle per cell. It was suggested that these corpuscles might represent magnetosomes and function as magnetosensors. Here we determine ferritin low-field paramagnetic susceptibility to estimate its magnetically induced intracellular behaviour. Physical simulations show that ferritin corpuscles cannot be deformed or rotate in weak geomagnetic fields, and thus cannot provide magnetoreception via deformation of the cuticular plate. Furthermore, we reached an alternative hypothesis that ferritin corpuscle in avian ears may function as an intracellular electromagnetic oscillator. Such an oscillator would generate additional cellular electric potential related to normal cell conditions. Though the phenomenon seems to be weak, this effect deserves further analyses. PMID:25551148

  18. Objective assessment of endogenous collagen in vivo during tissue repair by laser induced fluorescence.

    PubMed

    Prabhu, Vijendra; Rao, Satish B S; Fernandes, Edward Mark; Rao, Anuradha C K; Prasad, Keerthana; Mahato, Krishna K

    2014-01-01

    Collagen, a triple helical protein with the primary role of mechanical function, provides tensile strength to the skin, and plays a pivotal task in tissue repair. During tissue regeneration, collagen level increases gradually and therefore, monitoring of such changes in vivo by laser induced fluorescence was the main objective behind the present study. In order to accomplish this, 15 mm diameter excisional wounds were created on six to eight week old Swiss albino mice. The collagen deposition accelerated upon irradiation of single exposure of 2 J/cm2 He-Ne laser dose immediately after wounding was recorded by laser induced autofluorescence in vivo along with un-illuminated and un-wounded controls. Autofluorescence spectra were recorded for each animal of the experimental groups on 0, 5, 10, 30, 45 and 60 days post-wounding, by exciting the granulation tissue/skin with 325 nm He-Cd laser. The variations in the average collagen intensities from the granulation tissue/skin of mice were inspected as a function of age and gender. Further, the spectral findings of the collagen synthesis in wound granulation tissue/un-wounded skin tissues were validated by Picro-Sirius red- polarized light microscopy in a blinded manner through image analysis of the respective collagen birefringence. The in vivo autofluorescence studies have shown a significant increase in collagen synthesis in laser treated animals as compared to the un-illuminated controls. Image analysis of the collagen birefringence further authenticated the ability of autofluorescence in the objective monitoring of collagen in vivo. Our results clearly demonstrate the potential of laser induced autofluorescence in the monitoring of collegen synthesis during tissue regeneration, which may have clinical implications. PMID:24874229

  19. Laser-induced collagen remodeling and deposition within the basilar membrane of the mouse cochlea

    PubMed Central

    Wenzel, Gentiana I.; Anvari, Bahman; Mazhar, Amaan; Pikkula, Brian; Oghalai, John S.

    2013-01-01

    The cochlea is the mammalian organ of hearing. Its predominant vibratory element, the basilar membrane, is tonotopically tuned, based on the spatial variation of its mass and stiffness. The constituent collagen fibers of the basilar membrane affect its stiffness. Laser irradiation can induce collagen remodeling and deposition in various tissues. We tested whether similar effects could be induced within the basilar membrane. Trypan blue was perfused into the scala tympani of anesthetized mice to stain the basilar membrane. We then irradiated the cochleas with a 694-nm pulsed ruby laser at 15 or 180 J /cm2. The mice were sacrificed 14 to 16 days later and collagen organization was studied. Polarization microscopy revealed that laser irradiation increased the birefringence within the basilar membrane in a dose-dependent manner. Electron microscopy demonstrated an increase in the density of collagen fibers and the deposition of new fibrils between collagen fibers after laser irradiation. As an assessment of hearing, auditory brainstem response (ABR) thresholds were found to increase moderately after 15 J/cm2 and substantially after 180 J /cm2. Our results demonstrate that collagen remodeling and new collagen deposition occurs within the basilar membrane after laser irradiation in a similar fashion to that found in other tissues. PMID:17477714

  20. A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation.

    PubMed

    Buonanno, M; Randers-Pehrson, G; Smilenov, L B; Kleiman, N J; Young, E; Ponnayia, B; Brenner, D J

    2015-08-01

    Radiation-induced bystander effects have been observed in vitro and in cell and tissue culture models, however, there are few reported studies showing these effects in vivo. To our knowledge, this is the first reported study on bystander effects induced by microbeam irradiation in an intact living mammal. The mouse ear was used to investigate radiation-induced bystander effects in keratinocytes, utilizing a 3 MeV proton microbeam (LET 13.1 keV/μm) with a range in skin of about 135 μm. Using a custom-designed holder, the ear of an anesthetized C57BL/6J mouse was flattened by gentle suction and placed over the microbeam port to irradiate cells along a 35 μm wide, 6 mm long path. Immunohistochemical analysis of γ-H2AX foci formation in tissue sections revealed, compared to control tissue, proton-induced γ-H2AX foci formation in one of the two epidermal layers of the mouse ear. Strikingly, a higher number of cells than expected showed foci from direct irradiation effects. Although the proton-irradiated line was ~35 μm wide, the average width spanned by γ-H2AX-positive cells exceeded 150 μm. Cells adjacent to or in the epidermal layer opposite the γ-H2AX-positive region did not exhibit foci. These findings validate this mammalian model as a viable system for investigating radiation-induced bystander effects in an intact living organism. PMID:26207682

  1. Distinct roles of GPVI and integrin α2β1 in platelet shape change and aggregation induced by different collagens

    PubMed Central

    Jarvis, Gavin E; Atkinson, Ben T; Snell, Daniel C; Watson, Steve P

    2002-01-01

    Various platelet membrane glycoproteins have been proposed as receptors for collagen, in some cases as receptors for specific collagen types. In this study we have compared the ability of a range of collagen types to activate platelets. Bovine collagen types I–V, native equine tendon collagen fibrils and collagen-related peptide (CRP) all induced platelet aggregation and shape change. Responses were abolished in FcRγ chain-deficient platelets, which also lack GPVI, indicating a critical dependence on the GPVI/FcRγ chain complex. Responses to all collagens were unaffected in CD36-deficient platelets. A monoclonal antibody (6F1) which binds to the α2 integrin subunit of human platelets had a minimal effect on the rate and extent of aggregation induced by the collagens; however, it delayed the onset of aggregation following addition of all collagens. For shape change, 6F1 abolished the response induced by collagen types I and IV, substantially attenuated that to collagen types II, III and V, but only partially inhibited Horm collagen. Simultaneous blockade of the P2Y1 and P2Y12 receptors, and inhibition of cyclo-oxygenase demonstrated that CRP can activate platelets independently of ADP and TxA2; however, responses to the collagens were dependent on these mediators. This study confirms the importance of the GPVI/FcRγ chain complex in platelet responses induced by a range of collagen agonists, while providing no evidence for collagen type-specific receptors. It also provides evidence for a modulatory role of α2β1, the significance of which depends on the collagen preparation. PMID:12183336

  2. Non-thermal atmospheric plasma brush induces HEMA grafting onto dentin collagen

    PubMed Central

    Chen, Mingsheng; Zhang, Ying; Dusevich, Vladimir; Liu, Yi; Yu, Qingsong; Wang, Yong

    2014-01-01

    Objective Non-thermal atmospheric plasma (NTAP) brush has been regarded as a promising technique to enhance dental interfacial bonding. However, the principal enhancement mechanisms have not been well identified. In this study, the effect of non-thermal plasmas on grafting of HEMA, a typical dental monomer, onto dentin collagen thin films was investigated. Methods Human dentin was sectioned into 10-um-thick films. After total demineralization in 0.5 M EDTA solution for 30 min, the dentin collagen films were water-rinsed, air-dried, treated with 35 wt% HEMA aqueous solution. The films were then subject to plasma-exposure under a NTAP brush with different time (1–8 min) / input power (5–15 w). For comparison, the dentin collagen films were also treated with the above HEMA solution containing photo-initiators, then subject to light-curing. After plasma-exposure or light-curing, the HEMA-collagen films were rinsed in deionized water, and then examined by FTIR spectroscopy and TEM. Results The FITR results indicated that plasma-exposure could induce significant HEMA grafting onto dentin collagen thin films. In contrast, light-curing led to no detectable interaction of HEMA with dentin collagen. Quantitative IR spectral analysis (i.e., 1720/3075 or 749/3075, HEMA/collagen ratios) further suggested that the grafting efficacy of HEMA onto the plasma-exposed collagen thin films strongly depended on the treatment time and input power of plasmas. TEM results indicated that plasma treatment did not alter collagen’s banding structure. Significance The current study provides deeper insight into the mechanism of dental adhesion enhancement induced by non-thermal plasmas treatment. The NTAP brush could be a promising method to create chemical bond between resin monomers and dentin collagen. PMID:25458523

  3. Swimmer's Ear

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Swimmer's Ear KidsHealth > For Kids > Swimmer's Ear Print A A ... How Do I Know if I Have Swimmer's Ear? Swimmer's ear may start with some itching, but ...

  4. Ear Tubes

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  5. Electrospun tilapia collagen nanofibers accelerating wound healing via inducing keratinocytes proliferation and differentiation.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2016-07-01

    The development of biomaterials with the ability to induce skin wound healing is a great challenge in biomedicine. In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4(+)/CD8(+) lymphocytes, and the level of IgG or IgM in Sprague-Dawley rats. The tensile strength and contact angle of collagen nanofibers were 6.72±0.44MPa and 26.71±4.88°, respectively. They also had good thermal stability and swelling property. Furthermore, the nanofibers could significantly promote the proliferation of human keratinocytes (HaCaTs) and stimulate epidermal differentiation through the up-regulated gene expression of involucrin, filaggrin, and type I transglutaminase in HaCaTs. The collagen nanofibers could also facilitate rat skin regeneration. In the present study, electrospun biomimetic tilapia skin collagen nanofibers were succesfully prepared, were proved to have good bioactivity and could accelerate rat wound healing rapidly and effectively. These biological effects might be attributed to the biomimic extracellular matrix structure and the multiple amino acids of the collagen nanofibers. Therefore, the cost-efficient tilapia collagen nanofibers could be used as novel wound dressing, meanwhile effectively avoiding the risk of transmitting animal disease in the future clinical apllication. PMID:27037778

  6. Proneurotrophin-3 may induce Sortilin dependent death in inner ear neurons

    PubMed Central

    Tauris, Jacob; Gustafsen, Camilla; Christensen, Erik Ilsø; Jansen, Pernille; Nykjaer, Anders; Nyengaard, Jens R.; Teng, Kenneth K.; Schwarz, Elisabeth; Ovesen, Therese; Madsen, Peder; Petersen, Claus Munck

    2010-01-01

    The precursor of the neurotrophin NGF (proNGF) serves physiological functions distinct from its mature counterpart as it induces neuronal apoptosis through activation of a p75 neurotrophin receptor (p75NTR) and Sortilin death-signalling complex. The neurotrophins BDNF and NT3 provide essential trophic support to auditory neurons. Injury to the neurotrophin secreting cells in the inner ear is followed by irreversible degeneration of spiral ganglion neurons with consequences such as impaired hearing or deafness. Lack of mature neurotrophins may explain the degeneration of spiral ganglion neurons, but another mechanism is possible since unprocessed proNTs released from the injured cells may contribute to the degeneration by induction of apoptosis. Recent studies demonstrate that proBDNF, like proNGF, is a potent inducer of Sortilin:p75NTR mediated apoptosis. In addition, a coincident upregulation of proBDNF and p75NTR has been observed in degenerating spiral ganglion neurons, but the Sortilin expression in the inner ear is unresolved. Here we demonstrate that Sortilin and p75NTR are coexpressed in neurons of the neonatal inner ear. Furthermore, we establish that proNT3 exhibits high affinity binding to Sortilin and has the capacity to enhance cell surface Sortilin:p75NTR complex formation as well as to mediate apoptosis in neurons coexpressing p75NTR and Sortilin. Based on examination of wt and Sortilin deficient mouse embryos, Sortilin does not significantly influence the developmental selection of spiral ganglion neurons. However, our results suggest that proNT3 and proBDNF may play important roles in the response to noise-induced injuries or ototoxic damage via the Sortilin:p75NTR death-signalling complex. PMID:21261755

  7. Polymerized-Type I Collagen Induces Upregulation of Foxp3-Expressing CD4 Regulatory T Cells and Downregulation of IL-17-Producing CD4+ T Cells (Th17) Cells in Collagen-Induced Arthritis

    PubMed Central

    Furuzawa-Carballeda, Janette; Macip-Rodríguez, Perla; Galindo-Feria, Angeles S.; Cruz-Robles, David; Soto-Abraham, Virgina; Escobar-Hernández, Sergio; Aguilar, Diana; Alpizar-Rodríguez, Deshiré; Férez-Blando, Karen; Llorente, Luis

    2012-01-01

    Previous studies showed that polymerized-type I collagen (polymerized collagen) exhibits potent immunoregulatory properties. This work evaluated the effect of intramuscular administration of polymerized collagen in early and established collagen-induced arthritis (CIA) in mice and analyzed changes in Th subsets following therapy. Incidence of CIA was of 100% in mice challenged with type II collagen. Clinimorphometric analysis showed a downregulation of inflammation after administration of all treatments (P < 0.05). Histological analysis showed that the CIA-mice group had extensive bone erosion, pannus and severe focal inflammatory infiltrates. In contrast, there was a remarkable reduction in the severity of arthritis in mice under polymerized collagen, methotrexate or methotrexate/polymerized collagen treatment. Polymerized Collagen but not methotrexate induced tissue joint regeneration. Polymerized Collagen and methotrexate/polymerized collagen but not methotrexate alone induces downregulation of CD4+/IL17A+ T cells and upregulation of Tregs and CD4+/IFN-γ+ T cells. Thus, Polymerized Collagen could be an effective therapeutic agent in early and established rheumatoid arthritis by exerting downregulation of autoimmune inflammation. PMID:22028728

  8. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    SciTech Connect

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo; Kim, So Young; Jang, Hwan-Hee; Ryu, Sung Ho; Kim, Beom Joon; Lee, Taehoon G.

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. Black-Right-Pointing-Pointer YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. Black-Right-Pointing-Pointer There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. Black-Right-Pointing-Pointer The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. Black-Right-Pointing-Pointer The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the {beta}1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate

  9. Gene Therapy Induces Antigen-Specific Tolerance in Experimental Collagen-Induced Arthritis

    PubMed Central

    Jirholt, Pernilla; Turesson, Olof; Wing, Kajsa; Holmdahl, Rikard; Kihlberg, Jan; Stern, Anna; Mårtensson, Inga-Lill; Henningsson, Louise; Gustafsson, Kenth; Gjertsson, Inger

    2016-01-01

    Here, we investigate induction of immunological tolerance by lentiviral based gene therapy in a mouse model of rheumatoid arthritis, collagen II-induced arthritis (CIA). Targeting the expression of the collagen type II (CII) to antigen presenting cells (APCs) induced antigen-specific tolerance, where only 5% of the mice developed arthritis as compared with 95% of the control mice. In the CII-tolerized mice, the proportion of Tregs as well as mRNA expression of SOCS1 (suppressors of cytokine signaling 1) increased at day 3 after CII immunization. Transfer of B cells or non-B cell APC, as well as T cells, from tolerized to naïve mice all mediated a certain degree of tolerance. Thus, sustainable tolerance is established very early during the course of arthritis and is mediated by both B and non-B cells as APCs. This novel approach for inducing tolerance to disease specific antigens can be used for studying tolerance mechanisms, not only in CIA but also in other autoimmune diseases. PMID:27159398

  10. Short Stimulation of Electro-Responsive PAA/Fibrin Hydrogel Induces Collagen Production

    PubMed Central

    Rahimi, Nastaran; Swennen, Geertje; Verbruggen, Sanne; Scibiorek, Martyna; Molin, Daniel G.

    2014-01-01

    Acrylic acid/fibrin hydrogel can mechanically stimulate cells when an external electrical field is applied, enabling them to migrate and align throughout the depth of the gel. The ability of electro-responsive polyacrylic acid (PAA)/fibrin hydrogel to promote collagen production and remodeling has been investigated by three-dimensional (3D) culturing and conditioning of smooth muscle cells (SMCs). SMCs-seeded hydrogels were subjected to an alternating electrical field (0.06 V/mm) for 2 h for one, two, or three times per week during 4 weeks of culturing. Fluorescent images of collagen structure and accumulation, assessed by CNA-35 probe, showed increased collagen content (>100-fold at 1× stimulation/week) in the center of the hydrogels after 4 weeks of culture. The increase in collagen production correlated with increasing extracellular matrix gene expression and resulted in significantly improved mechanical properties of the stimulated hydrogels. Matrix metalloproteinase (MMP)-2 activity was also significantly enhanced by stimulation, which probably has a role in the reorganization of the collagen. Short stimulation (2 h) induced a favorable response in the cells and enhanced tissue formation and integrity of the scaffold by inducing collagen production. The presented set up could be used for conditioning and improving the functionality of current tissue-engineered vascular grafts. PMID:24341313

  11. Apigenin Induces Dermal Collagen Synthesis Via smad2/3 Signaling Pathway

    PubMed Central

    Zhang, Y.; Wang, J.; Cheng, X.; Yi, B.; Zhang, X.; Li, Q.

    2015-01-01

    Decrease in fibroblast-produced collagen has been proven to be the pivotal cause of skin aging, but there is no satisfactory drug which directly increases dermal thickness and collage density. Here we found that a flavonoid natural product, apigenin, could significantly increase collagen synthesis. NIH/3T3 and primary human dermal fibroblasts (HDFs) were incubated with various concentrations of apigenin, with dimethyl sulfoxide (DMSO) serving as the negative control. Real-time reverse-transcription polymerase chain reaction (PCR), Western Blot, and Toluidine blue staining demonstrated that apigenin stimulated type-I and type-III collagen synthesis of fibroblasts on the mRNA and protein levels. Meanwhile, apigenin did not induce expression of alpha smooth muscle actin (α-SMA) in vitro and in vivo, a fibrotic marker in living tissues. Then the production of collagen was confirmed by Masson’s trichrome stain, Picrosirius red stain and immunohistochemistry in mouse models. We also clarified that this compound induced collagen synthesis by activating smad2/3 signaling pathway. Taken together, without obvious influence on fibroblasts’ apoptosis and viability, apigenin could promote the type-I and type-III collagen synthesis of dermal fibroblasts in vitro and in vivo, thus suggesting that apigenin may serve as a potential agent for esthetic and reconstructive skin rejuvenation. PMID:26150153

  12. In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

    PubMed

    Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

    2007-03-01

    In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition. PMID:17261065

  13. Isorhamnetin attenuates collagen-induced arthritis via modulating cytokines and oxidative stress in mice

    PubMed Central

    Wang, Xuewen; Zhong, Wei

    2015-01-01

    Inflammation and oxidative stress were involved in the development and progression of rheumatoid arthritis (RA). Isorhamnetin has anti-inflammatory and anti-oxidative activities, but its effects on RA have not been investigated. In order to observe the possible therapeutic effects of isorhamnetin on RA, we established a collagen-induced arthritis mouse model and treated the animal with isorhamnetin for 3 weeks. Besides, fibroblast-like synoviocytes (FLS) were treated with lipopolysaccharide (LPS) and isorhamnetin. The severity of arthritis was assessed by arthritis score, joint destruction score and inflammation score. Levels of cytokines TNF-α, IL-1β, IL-6, IL-17A, IL-17F, IL-10 and IL-35 in the joint tissue homogenate and cell culture medium as well as anti-type II collagen antibody in serum were measured using ELISA. Contents of H2O2 and malondialdehyde (MDA) in joint tissue homogenate were measured using assay kits. We found collagen immunization induced significant arthritis in mice and isorhamnetin at the dose of 10 and 20 mg/kg/day could significantly attenuate the collagen-induced arthritis. Isorhamnetin also modulated the production of cytokines and suppressed the oxidative stress in the mice with collagen-induced arthritis at the dose of 10 and 20 mg/kg/day. These data suggested that isorhamnetin might be a potential agent for the management of RA. PMID:26629181

  14. Sulfur mustard induces an endoplasmic reticulum stress response in the mouse ear vesicant model

    SciTech Connect

    Chang, Yoke-Chen; Wang, James D.; Svoboda, Kathy K.; Casillas, Robert P.; Laskin, Jeffrey D.; Gordon, Marion K.; Gerecke, Donald R.

    2013-04-15

    The endoplasmic reticulum (ER) stress response is a cell survival pathway upregulated when cells are under severe stress. Severely damaged mouse ear skin exposed to the vesicant, sulfur mustard (bis-2-chloroethyl sulfide, SM), resulted in increased expression of ER chaperone proteins that accompany misfolded and incorrectly made proteins targeted for degradation. Time course studies with SM using the mouse ear vesicant model (MEVM) showed progressive histopathologic changes including edema, separation of the epidermis from the dermis, persistent inflammation, upregulation of laminin γ2 (one of the chains of laminin-332, a heterotrimeric skin glycoprotein required for wound repair), and delayed wound healing from 24 h to 168 h post exposure. This was associated with time related increased expression of the cell survival ER stress marker, GRP78/BiP, and the ER stress apoptosis marker, GADD153/CHOP, suggesting simultaneous activation of both cell survival and non-mitochondrial apoptosis pathways. Dual immunofluorescence labeling of a keratinocyte migration promoting protein, laminin γ2 and GRP78/BIP, showed colocalization of the two molecules 72 h post exposure indicating that the laminin γ2 was misfolded after SM exposure and trapped within the ER. Taken together, these data show that ER stress is induced in mouse skin within 24 h of vesicant exposure in a defensive response to promote cell survival; however, it appears that this response is rapidly overwhelmed by the apoptotic pathway as a consequence of severe SM-induced injury. - Highlights: ► We demonstrated ER stress response in the mouse ear vesicant model. ► We described the asymmetrical nature of wound repair in the MEVM. ► We identified the distribution of various ER stress markers in the MEVM.

  15. Collagen V-induced nasal tolerance downregulates pulmonary collagen mRNA gene and TGF-beta expression in experimental systemic sclerosis

    PubMed Central

    2010-01-01

    Background The purpose of this study was to evaluate collagen deposition, mRNA collagen synthesis and TGF-beta expression in the lung tissue in an experimental model of scleroderma after collagen V-induced nasal tolerance. Methods Female New Zealand rabbits (N = 12) were immunized with 1 mg/ml of collagen V in Freund's adjuvant (IM). After 150 days, six immunized animals were tolerated by nasal administration of collagen V (25 μg/day) (IM-TOL) daily for 60 days. The collagen content was determined by morphometry, and mRNA expressions of types I, III and V collagen were determined by Real-time PCR. The TGF-beta expression was evaluated by immunostaining and quantified by point counting methods. To statistic analysis ANOVA with Bonferroni test were employed for multiple comparison when appropriate and the level of significance was determined to be p < 0.05. Results IM-TOL, when compared to IM, showed significant reduction in total collagen content around the vessels (0.371 ± 0.118 vs. 0.874 ± 0.282, p < 0.001), bronchioles (0.294 ± 0.139 vs. 0.646 ± 0.172, p < 0.001) and in the septal interstitium (0.027 ± 0.014 vs. 0.067 ± 0.039, p = 0.026). The lung tissue of IM-TOL, when compared to IM, showed decreased immunostaining of types I, III and V collagen, reduced mRNA expression of types I (0.10 ± 0.07 vs. 1.0 ± 0.528, p = 0.002) and V (1.12 ± 0.42 vs. 4.74 ± 2.25, p = 0.009) collagen, in addition to decreased TGF-beta expression (p < 0.0001). Conclusions Collagen V-induced nasal tolerance in the experimental model of SSc regulated the pulmonary remodeling process, inhibiting collagen deposition and collagen I and V mRNA synthesis. Additionally, it decreased TGF-beta expression, suggesting a promising therapeutic option for scleroderma treatment. PMID:20047687

  16. Sulfur mustard induces an endoplasmic reticulum stress response in the mouse ear vesicant model

    PubMed Central

    Chang, Yoke-Chen; Wang, James D.; Svoboda, Kathy K.; Casillas, Robert P.; Laskin, Jeffrey D.; Gordon, Marion K.; Gerecke, Donald R.

    2013-01-01

    The endoplasmic reticulum (ER) stress response is a cell survival pathway upregulated when cells are under severe stress. Severely damaged mouse ear skin exposed to the vesicant, sulfur mustard (bis-2-chloroethyl sulfide, SM), resulted in increased expression of ER chaperone proteins that accompany misfolded and incorrectly made proteins targeted for degradation. Time course studies with SM using the mouse ear vesicant model (MEVM) showed progressive histopathologic changes including edema, separation of the epidermis from the dermis, persistent inflammation, upregulation of laminin γ2 (one of the chains of laminin-332, a heterotrimeric skin glycoprotein required for wound repair), and delayed wound healing from 24 h to 168 h post exposure. This was associated with time related increased expression of the cell survival ER stress marker, GRP78/BiP, and the ER stress apoptosis marker, GADD153/CHOP, suggesting simultaneous activation of both cell survival and non-mitochondrial apoptosis pathways. Dual immunofluorescence labeling of a keratinocyte migration promoting protein, laminin γ2 and GRP78/BIP, showed colocalization of the two molecules 72 h post exposure indicating that the laminin γ2 was misfolded after SM exposure and trapped within the ER. Taken together, these data show that ER stress is induced in mouse skin within 24 h of vesicant exposure in a defensive response to promote cell survival; however, it appears that this response is rapidly overwhelmed by the apoptotic pathway as a consequence of severe SM-induced injury. PMID:23357548

  17. The effects of an inhibitor of diglyceride lipase on collagen-induced platelet activation.

    PubMed

    Jackson, Elke C G; Ortar, Giorgio; McNicol, Archie

    2013-12-01

    Human platelet activation by collagen occurs in a dose-dependent manner. High concentrations of collagen bind to a pair of receptors, the α2β1 integrin and glycoprotein (GP)VI/Fc-receptor γ-chain (FcRγ), which stimulate a cascade of events including Syk, LAT, Btk, Gads, and phospholipase Cγ2, leading to calcium release and protein kinase C (PKC) activation. Calcium and PKC are responsible for a range of platelet responses including exocytosis and aggregation, as well as the cytosolic phospholipase A2 (cPLA2)-mediated release of arachidonic acid, which is converted to thromboxane (Tx)A2. In contrast, low concentrations of collagen are acutely aspirin-sensitive, and calcium release and aggregation are TxA2-dependent. Under these conditions, cPLA2 is not involved and it has been suggested that phospholipase C generates 1,2-diacylglycerol (DG) from which arachidonic acid is liberated by diglyceride lipase (DGL). Here a novel DGL blocker (OMDM-188) inhibited collagen-, but not arachidonic acid-induced aggregation and TxA2 synthesis. Furthermore, OMDM-188 inhibited collagen-induced arachidonic acid release. Finally OMDM-188 inhibited collagen-induced p38(MAPK) phosphorylation, but not extracellular signal-regulated kinase (ERK) phosphorylation, with no effect on the phosphorylation of either enzyme in response to arachidonic acid. Taken together, these data suggest a role for a pathway involving phospholipase C liberating DG from membrane phospholipids in response to minimally activating concentrations of collagen. The DG serves as a substrate for DGL, potentially under the regulations of p38(MAPK), to release arachidonic acid, which is subsequently converted to TxA2, which mediates the final platelet response. PMID:24042163

  18. In vivo left ventricular function and collagen expression in aldosterone/salt-induced hypertension.

    PubMed

    Ramirez-Gil, J F; Delcayre, C; Robert, V; Wassef, M; Trouve, P; Mougenot, N; Charlemagne, D; Lechat, P

    1998-12-01

    Cardiac fibrosis is linked to aldosterone-induced hypertension, but the effects on in vivo left ventricular (LV) function are not established. We studied the relations between in vivo LV function and aldosterone/salt cardiac fibrosis. Adult guinea pigs (GPs) were treated for 3 months with an aldosterone infusion and high-salt diet. This treatment induced arterial hypertension (+35%) and moderate LV hypertrophy (LVH; +60%) without right ventricular (RV) hypertrophy. Echo-Doppler LV assessment demonstrated unaltered cardiac output, stroke volume, or LV relaxation. Type I collagen messenger RNA (mRNA) was significantly increased in both ventricles (LV, +48%; RV, +77%) and accompanied by a significant increase in total collagen deposition (LV, from 0.52% in controls to 4.4% in treated GPs; RV, from 0.82 to 5.5% in treated GPs). Plasma norepinephrine levels increased 2.6-fold (p < 0.01) and correlated with the increase in collagen deposition in both ventricles. Collagen content was not correlated with hypertension or LVH. We conclude that aldosterone administration induces cardiac collagen accumulation and a sympathetic stimulation, which might preserve systolic and diastolic function. PMID:9869498

  19. Nimesulide Improves the Symptomatic and Disease Modifying Effects of Leflunomide in Collagen Induced Arthritis

    PubMed Central

    Al-Abd, Ahmed M.; Al-Abbasi, Fahad A.; Nofal, Salwa M.; Khalifa, Amani E.; Williams, Richard O.; El-Eraky, Wafaa I.; Nagy, Ayman A.; Abdel-Naim, Ashraf B.

    2014-01-01

    Nimesulide is a COX-2 inhibitor used for symptomatic relief of rheumatoid arthritis. Leflunomide is an anti-pyrimidine used to manage the progression of rheumatoid arthritis. Herein we studied the influence of nimesulide and leflunomide combination in terms of disease symptoms and progression using collagen-induced arthritis model in mice, as a model for rheumatoid arthritis. Collagen induced arthritis was induced by immunization with type II collagen. Assessment of joint stiffness and articular hyperalgesia were evaluated using a locomotor activity cage and the Hargreaves method, respectively. Disease progression was assessed via arthritic index scoring, X-ray imaging, myeloperoxidase enzyme activity and histopathologic examination. Nimesulide induced only transient symptomatic alleviation on the top of decreased leucocytic infiltration compared to arthritis group. However, nimesulide alone failed to induce any significant improvement in the radiological or pathological disease progression. Leflunomide alone moderately alleviates the symptoms of arthritis and moderately retarded the radiological and pathological disease progression. Combination of nimesulide and leflunomide significantly improved symptomatic (analgesia and joint stiffness) and arthritic disease progression (radiological, pathological and Myeloperoxidase enzyme activity) in collagen induced arthritis animal model. PMID:25375820

  20. Changes in corneal collagen induced by holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Timberlake, George T.; Reinke, Martin H.; Miller, Alvin

    1996-05-01

    Holmium:YAG laser thermokeratoplasty corrects hyperopia (farsightedness) by producing small areas of corneal collagen shrinkage that cause the central cornea to bulge outward, increasing optical power. Collagen shrinkage is probably caused by laser-heated corneal water, but details of the shrinkage mechanism are not known. We investigated the shrinkage mechanism by measuring changes in corneal ultrastructure, surface shrinkage, water content, and strength following Ho:YAG laser exposures. Morphological changes in collagen were documented by measurements from electron micrographs. Corneal adhesive strength was determined by measuring tearing force in a plane parallel to the corneal surface. Laser-induced water loss was measured by weighing corneal samples before and after exposure. Corneal surface shrinkage was assessed by photographing the movement of particles on the cornea. Lasered collagen fibrils increased in diameter, lost their orderly arrangement, and appeared `frayed.' The corneal surface contracted toward lasered areas with a maximal shift of approximately 190 micrometers , more than could be explained by a model based on collagen fibril changes. Water loss plays a minor role in corneal shrinkage since corneal samples lost about only about 1.4% of their weight after massive laser exposure. Despite marked changes in collagen structure, corneal adhesive force was unchanged.

  1. Blister-inducing antibodies target multiple epitopes on collagen VII in mice

    PubMed Central

    Csorba, Kinga; Chiriac, Mircea Teodor; Florea, Florina; Ghinia, Miruna Georgiana; Licarete, Emilia; Rados, Andreea; Sas, Alexandra; Vuta, Vlad; Sitaru, Cassian

    2014-01-01

    Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease of mucous membranes and the skin caused by autoantibodies against collagen VII. In silico and wet laboratory epitope mapping studies revealed numerous distinct epitopes recognized by EBA patients' autoantibodies within the non-collagenous (NC)1 and NC2 domains of collagen VII. However, the distribution of pathogenic epitopes on collagen VII has not yet been described. In this study, we therefore performed an in vivo functional epitope mapping of pathogenic autoantibodies in experimental EBA. Animals (n = 10/group) immunized against fragments of the NC1 and NC2 domains of collagen VII or injected with antibodies generated against the same fragments developed to different extent experimental EBA. Our results demonstrate that antibodies targeting multiple, distinct epitopes distributed over the entire NC1, but not NC2 domain of collagen VII induce blistering skin disease in vivo. Our present findings have crucial implications for the development of antigen-specific B- and T cell-targeted therapies in EBA. PMID:25091020

  2. Blister-inducing antibodies target multiple epitopes on collagen VII in mice.

    PubMed

    Csorba, Kinga; Chiriac, Mircea Teodor; Florea, Florina; Ghinia, Miruna Georgiana; Licarete, Emilia; Rados, Andreea; Sas, Alexandra; Vuta, Vlad; Sitaru, Cassian

    2014-09-01

    Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease of mucous membranes and the skin caused by autoantibodies against collagen VII. In silico and wet laboratory epitope mapping studies revealed numerous distinct epitopes recognized by EBA patients' autoantibodies within the non-collagenous (NC)1 and NC2 domains of collagen VII. However, the distribution of pathogenic epitopes on collagen VII has not yet been described. In this study, we therefore performed an in vivo functional epitope mapping of pathogenic autoantibodies in experimental EBA. Animals (n = 10/group) immunized against fragments of the NC1 and NC2 domains of collagen VII or injected with antibodies generated against the same fragments developed to different extent experimental EBA. Our results demonstrate that antibodies targeting multiple, distinct epitopes distributed over the entire NC1, but not NC2 domain of collagen VII induce blistering skin disease in vivo. Our present findings have crucial implications for the development of antigen-specific B- and T cell-targeted therapies in EBA. PMID:25091020

  3. Hindlimb unloading induces a collagen isoform shift in the soleus muscle of the rat

    NASA Technical Reports Server (NTRS)

    Miller, T. A.; Lesniewski, L. A.; Muller-Delp, J. M.; Majors, A. K.; Scalise, D.; Delp, M. D.

    2001-01-01

    To determine whether hindlimb unloading (HU) alters the extracellular matrix of skeletal muscle, male Sprague-Dawley rats were subjected to 0 (n = 11), 1 (n = 11), 14 (n = 13), or 28 (n = 11) days of unloading. Remodeling of the soleus and plantaris muscles was examined biochemically for collagen abundance via measurement of hydroxyproline, and the percentage of cross-sectional area of collagen was determined histologically with picrosirius red staining. Total hydroxyproline content in the soleus and plantaris muscles was unaltered by HU at any time point. However, the relative proportions of type I collagen in the soleus muscle decreased relative to control (Con) with 14 and 28 days HU (Con 68 +/- 5%; 14 days HU 53 +/- 4%; 28 days HU 53 +/- 7%). Correspondingly, type III collagen increased in soleus muscle with 14 and 28 days HU (Con 32 +/- 5%; 14 days HU 47 +/- 4%; 28 days HU 48 +/- 7%). The proportion of type I muscle fibers in soleus muscle was diminished with HU (Con 96 +/- 2%; 14 days HU 86 +/- 1%; 28 days HU 83 +/- 1%), and the proportion of hybrid type I/IIB fibers increased (Con 0%; 14 days HU 8 +/- 2%; 28 days HU 14 +/- 2%). HU had no effect on the proportion of type I and III collagen or muscle fiber composition in plantaris muscle. The data demonstrate that HU induces a shift in the relative proportion of collagen isoform (type I to III) in the antigravity soleus muscle, which occurs concomitantly with a slow-to-fast myofiber transformation.

  4. Effect of drill-induced noise on hearing in non-operated ear

    PubMed Central

    Abtahi, Seyyed Hamidreza; Fazel, Alireza; Rogha, Mehrdad; Nilforoush, Mohamadhosein; Solooki, Reza

    2016-01-01

    Background: The aim of this study was to evaluate the effect of drill-generated noise on hearing loss in non-operated ear and if any, was temporary or persistent. Materials and Methods: In this prospective clinical study, 23 patients who had undergone mastoidectomy and normal contralateral hearing were enrolled. Patients were evaluated preoperatively and postoperatively (1 and 7 days) following surgery using low and high-frequency pure tone audiometry (PTA) and low and high-frequency transient evoked and distortion product otoacoustic emission (DPOAE) testing. Results: Comparing preoperative and 1-day after surgery, PTA averages were significantly different at low frequencies, but no statistical significant differences were observed at 0.25 KHz and high-frequencies. Comparing 1-day after surgery and 7 days after surgery showed that, PTA averages at 0.5, 2 and 2 KHz were significantly different with no significant differences at the other average of thresholds in low and high frequencies; PTA average at 1 KHz was significantly different with, no significant differences at the other averages of thresholds in low and high frequencies. DPOAEs showed a significant difference preoperative and 1-day after surgery, 1-day and 7 days after, but DPOAEs were not significantly different. Transiently evoked otoacoustic emissions (TEOAEs) had a significant difference preoperative and 1-day after surgery, 1-day and 7 days after but when comparing preoperative and 7 days after surgery, TEOAEs were not significantly different. Conclusions: Drill-induced noise during ear surgery (mastoidectomy) can cause reversible changes in PTA, DPOAEs and TEOAEs in the non-operated ear. PMID:27274502

  5. Histological characteristics of collagen denaturation and injuries in bipolar radiofrequency-induced colonic anastomoses.

    PubMed

    Zhao, Lingxi; Zhuo, Changhua; Song, Chengli; Li, Xinxiang; Zhou, Yu; Shi, Debing

    2015-03-01

    Bipolar radiofrequency-induced thermo-fusion has been explored as an advanced surgical method for intestinal anastomoses; however, the histological characteristics of collagen denaturation and injuries arising from this process remain unclear. The aim of this study was to investigate the microcosmic changes and tissue damage of fusion regions with various parameters of injury. Ex vivo colons of pigs were fused serosa-serosa on two carrier rings, which were installed on a homemade anastomotic device. Five levels of compressive pressure from 171 to 313 kPa were applied for 5s to fuse the colons under radiofrequency power of 160 W, and then the collagen denaturation of the fused region was examined by transmission electron microscopy. Light microscopy was utilized to observe histological slices that were stained with picrosirius red in order to visualize the tissue injuries under two levels of radiofrequency power (120 vs. 140 W) and operation time (5 vs. 10s). Transmission electron micrographs showed that increased compressive pressure led to thicker denatured collagen fibrils and wider gaps between each collagen fibril. Serosa adhesion regions appeared abundant in collagen. No histological differences were observed when 120 W of power was applied for 5 and 10s. Significant muscle cracking occurred when colons were fused using 140 W for 5s. When the operation time was extended to 10s, 140 W led to tight fusion and less splitting on muscles. These results suggest that higher compressive pressure results in more severe collagen unfolding and also reduces collagen crosslinking in fused colons. Improved radiofrequency power along with operation time could avoid tissue injury upon radiofrequency-induced colonic anastomoses. PMID:25434604

  6. Aortic VCAM-1: an early marker of vascular inflammation in collagen-induced arthritis.

    PubMed

    Denys, Anne; Clavel, Gaëlle; Lemeiter, Delphine; Schischmanoff, Olivier; Boissier, Marie-Christophe; Semerano, Luca

    2016-05-01

    Cardiovascular disease (CVD) is a major cause of morbidity and mortality in rheumatoid arthritis (RA). There are limited experimental data on vascular involvement in arthritis models. To study the link between CVD and inflammation in RA, we developed a model of vascular dysfunction and articular inflammation by collagen-induced arthritis (CIA) in C57Bl/6 (B6) mice. We studied the expression of vascular inflammatory markers in CIA with and without concomitant hyperlipidic diet (HD). Collagen-induced arthritis was induced with intradermal injection of chicken type-II collagen followed by a boost 21 days later. Mice with and without CIA were fed a standard diet or an HD for 12 weeks starting from the day of the boost. Arthritis severity was evaluated with a validated clinical score. Aortic mRNA levels of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS) and interleukin-17 were analysed by quantitative RT-PCR. Vascular cell adhesion molecule-1 localization in the aortic sinus was determined by immunohistochemistry. Atherosclerotic plaque presence was assessed in aortas. Collagen-induced arthritis was associated with increased expression of VCAM-1, independent of diet. VCAM-1 overexpression was detectable as early as 4 weeks after collagen immunization and persisted after 15 weeks. The HD induced atheroma plaque formation and aortic iNOS expression regardless of CIA. Concomitant CIA and HD had no additive effect on atheroma or VCAM-1 or iNOS expression. CIA and an HD diet induced a distinct and independent expression of large-vessel inflammation markers in B6 mice. This model may be relevant for the study of CVD in RA. PMID:26859834

  7. Regional alterations of type I collagen in rat tibia induced by skeletal unloading

    NASA Technical Reports Server (NTRS)

    Shiiba, Masashi; Arnaud, Sara B.; Tanzawa, Hideki; Kitamura, Eiji; Yamauchi, Mitsuo

    2002-01-01

    Skeletal unloading induces loss of mineral density in weight-bearing bones that leads to inferior bone mechanical strength. This appears to be caused by a failure of bone formation; however, its mechanisms still are not well understood. The objective of this study was to characterize collagen, the predominant matrix protein in bone, in various regions of tibia of rats that were subjected to skeletal unloading by 4 weeks tail suspension. Sixteen male Sprague-Dawley rats (4 months old) were divided into tail suspension and ambulatory controls (eight rats each). After the tail suspension, tibias from each animal were collected and divided into five regions and collagen was analyzed. The collagen cross-linking and the extent of lysine (Lys) hydroxylation in unloaded bones were significantly altered in proximal epiphysis, diaphysis, and, in particular, proximal metaphysis but not in distal regions. The pool of immature/nonmineralized collagen measured by its extractability with a chaotropic solvent was significantly increased in proximal metaphysis. These results suggest that skeletal unloading induced an accumulation of post-translationally altered nonmineralized collagen and that these changes are bone region specific. These alterations might be caused by impaired osteoblastic function/differentiation resulting in a mineralization defect.

  8. Regulation of collagen synthesis in human dermal fibroblasts by ascorbic-induced lipid peroxidation

    SciTech Connect

    Geesin, J.C. Johnson and Johnson Consumer Products, Inc., Skillman, NJ ); Gordon, J.S. ); Gordon, J.S. ); Berg, R.A. )

    1991-03-11

    Ascorbic acid has been shown to stimulate collagen synthesis through the induction of lipid peroxidation which leads to increased transcription of the collagen genes. To test the ability of aldehyde products of lipid peroxidation to mediate this effect, the authors treated cultured fibroblasts with 1-200{mu}M of malondialdehyde, acetaldehyde, glyoxal or hexenal in the presence of lipid peroxidation inducing or noninducing concentrations of ascorbic acid. The treatment process involved either pretreatment of cells for 66hrs with either concentration of ascorbate before a 6hr treatment in the presence of ascorbate and the aldehydes, or 6 or 72hr treatment of the cells in the presence of either concentration of ascorbate plus the aldehydes. No effect of any of these aldehydes was seen on ascorbate-stimulated collagen synthesis. Also, pretreatment of fibroblasts for 24hrs with 100nM phorbol myristate acetate (PMA), which produces down regulation of protein kinase C(PKC), failed to alter the ascorbate-stimulation of collagen synthesis. Additionally, the authors tested the ability of benzamide, a poly ACP ribosylation inhibitor, to inhibit the ascorbate response with no specific effect noted. These results do not support the proposed roles for aldehydes, PKC, or poly ADP ribosylation in the mediation of the lipid peroxidation induced stimulation of collagen synthesis.

  9. Glutaraldehyde-induced remineralization improves the mechanical properties and biostability of dentin collagen.

    PubMed

    Chen, Chaoqun; Mao, Caiyun; Sun, Jian; Chen, Yi; Wang, Wei; Pan, Haihua; Tang, Ruikang; Gu, Xinhua

    2016-10-01

    The purpose of this study was to induce a biomimetic remineralization process by using glutaraldehyde (GA) to reconstruct the mechanical properties and biostability of demineralized collagen. Demineralized dentin disks (35% phosphoric acid, 10s) were pretreated with a 5% GA solution for 3min and then cultivated in a calcium phosphate remineralization solution. The remineralization kinetics and superstructure of the remineralization layer were evaluated by Raman spectroscopy, transmission electron microscopy, scanning electron microscopy and nanoindentation tests. The biostability was examined by enzymatic degradation experiments. A significant difference was found in dentin remineralization process between dentin with and without GA pretreating. GA showed a specific affinity to dentin collagen resulting in the formation of a cross-linking superstructure. GA pretreating could remarkably shorten remineralization time from 7days to 2days. The GA-induced remineralized collagen fibrils were well encapsulated by newly formed hydroxyapatite mineral nanocrystals. With the nano-hydroxyapatite coating, both the mechanical properties (elastic modulus and hardness) and the biostability against enzymatic degradation of the collagen were significantly enhanced, matching those of natural dentin. The results indicated that GA cross-linking of dentin collagen could promote dentin biomimetic remineralization, resulting in an improved mechanical properties and biostability. It may provide a promising tissue-engineering technology for dentin repair. PMID:27287165

  10. Piperlongumine Blocks JAK2-STAT3 to Inhibit Collagen-Induced Platelet Reactivity Independent of Reactive Oxygen Species†

    PubMed Central

    Yuan, Hengjie; Houck, Katie L.; Tian, Ye; Bharadwaj, Uddalak; Hull, Ken; Zhou, Zhou; Zhou, Mingzhao; Wu, Xiaoping; Tweardy, David J.; Romo, Daniel; Fu, Xiaoyun; Zhang, Yanjun; Zhang, Jianning; Dong, Jing-fei

    2015-01-01

    Background Piperlongumine (PL) is a compound isolated from the piper longum plant. It possesses anti-cancer activities through blocking the transcription factor STAT3 and by inducing reactive oxygen species (ROS) in cancer, but not normal cells. It also inhibits platelet aggregation induced by collagen, but the underlying mechanism is not known. Objective We conducted in vitro experiments to test the hypothesis that PL regulates a non-transcriptional activity of STAT3 to specifically reduce the reactivity of human platelets to collagen. Results PL dose-dependently blocked collagen-induced platelet aggregation, calcium influx, CD62p expression and thrombus formation on collagen with a maximal inhibition at 100 μM. It reduced platelet microvesiculation induced by collagen. PL blocked the activation of JAK2 and STAT3 in collagen-stimulated platelets. This inhibitory effect was significantly reduced in platelets pretreated with a STAT3 inhibitor. Although PL induced ROS production in platelets; quenching ROS using excessive reducing agents: 20 μM GSH and 0.5 mM L-Cysteine, did not block the inhibitory effects. The NADPH oxidase inhibitor Apocynin also had no effect. Conclusions PL inhibited collagen-induced platelet reactivity by targeting the JAK2-STAT3 pathway. We also provide experimental evidence that PL and collagen induce different oxidants that have differential effects on platelets. Studying these differential effects may uncover new mechanisms of regulating platelet functions by oxidants in redox signals. PMID:26645674

  11. Type V Collagen Induced Tolerance Suppresses Collagen Deposition, TGF-β and Associated Transcripts in Pulmonary Fibrosis

    PubMed Central

    Vittal, Ragini; Mickler, Elizabeth A.; Fisher, Amanda J.; Zhang, Chen; Rothhaar, Katia; Gu, Hongmei; Brown, Krista M.; Emtiazdjoo, Amir; Lott, Jeremy M.; Frye, Sarah B.; Smith, Gerald N.; Sandusky, George E.; Cummings, Oscar W.; Wilkes, David S.

    2013-01-01

    Rationale Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease characterized by progressive scarring and matrix deposition. Recent reports highlight an autoimmune component in IPF pathogenesis. We have reported anti-col(V) immunity in IPF patients. The objective of our study was to determine the specificity of col(V) expression profile and anti-col(V) immunity relative to col(I) in clinical IPF and the efficacy of nebulized col(V) in pre-clinical IPF models. Methods Col(V) and col(I) expression profile was analyzed in normal human and IPF tissues. C57-BL6 mice were intratracheally instilled with bleomycin (0.025 U) followed by col(V) nebulization at pre-/post-fibrotic stage and analyzed for systemic and local responses. Results Compared to normal lungs, IPF lungs had higher protein and transcript expression of the alpha 1 chain of col(V) and col(I). Systemic anti-col(V) antibody concentrations, but not of anti-col(I), were higher in IPF patients. Nebulized col(V), but not col(I), prevented bleomycin-induced fibrosis, collagen deposition, and myofibroblast differentiation. Col(V) treatment suppressed systemic levels of anti-col(V) antibodies, IL-6 and TNF-α; and local Il-17a transcripts. Compared to controls, nebulized col(V)-induced tolerance abrogated antigen-specific proliferation in mediastinal lymphocytes and production of IL-17A, IL-6, TNF-α and IFN-γ. In a clinically relevant established fibrosis model, nebulized col(V) decreased collagen deposition. mRNA array revealed downregulation of genes specific to fibrosis (Tgf-β, Il-1β, Pdgfb), matrix (Acta2, Col1a2, Col3a1, Lox, Itgb1/6, Itga2/3) and members of the TGF-β superfamily (Tgfbr1/2, Smad2/3, Ltbp1, Serpine1, Nfkb/Sp1/Cebpb). Conclusions Anti-col(V) immunity is pathogenic in IPF, and col(V)-induced tolerance abrogates bleomycin-induced fibrogenesis and down regulates TGF- β-related signaling pathways. PMID:24204629

  12. Effect of cadmium chloride exposure during the induction of collagen induced arthritis.

    PubMed

    Ansari, Md Meraj; Neha; Khan, Haider A

    2015-08-01

    The precise cause of autoimmune diseases such as rheumatoid arthritis remains uncertain. Collagen induced arthritis (CIA) in animals is the most commonly used model of human rheumatoid arthritis (RA). Exposure of humans and animals to toxic metals is widespread. Cadmium is one of the most prevalent nephrotoxic heavy metal, but it may cause other systemic toxicity as well. Cadmium may cause adverse health effects by impairment of the immune systems and induction of reactive oxygen species. Since rheumatoid arthritis pathogenesis involve immune system disorder and chronic inflammation, the present study has been designed to find out the effect of cadmium chloride exposure on clinical manifestation of development of collagen induced rheumatoid arthritis. Arthritis was induced in rats by intradermal injection of emulsion of type II collagen in Complete Freund's Adjuvant. Rats were treated with cadmium chloride dissolved in drinking water at concentrations of 5ppm and 50ppm for 21 days from day of immunization. The effects of cadmium in the rats were assessed by biochemical parameters (articular elastase, articular nitrite, lipid peroxidation, reduced glutathione, catalase and superoxide dismutase) histopathological analysis and immunohistochemical expression of pro-inflammatory cytokines in rat joint tissue. Histopathological changes further confirmed the biochemical and immunohistochemical results. Our results suggest that exposure to cadmium chloride during the induction phase of collagen induced arthritis abrogate disease development at lower dose whereas exacerbates at higher dose in Wistar rats. PMID:26070417

  13. In vivo collagen turnover during development of thyroxine-induced left ventricular hypertrophy.

    PubMed

    Karim, M A; Ferguson, A G; Wakim, B T; Samarel, A M

    1991-02-01

    Cardiac fibroblasts synthesize large amounts of procollagens, yet only a small fraction of mature collagens accumulate in the extracellular matrix. To determine the roles of intracellular degradation of newly synthesized procollagens and extracellular degradation of mature collagens during normal growth and during thyroxine-induced left ventricular hypertrophy, in vivo left ventricular procollagen synthetic rates were assessed in control rats and rats treated with L-thyroxine for 1, 2, 4, and 8 wk (1 mg.kg-1.day-1). A modification of the flooding infusion method was developed using measurements of cardiac prolyl-tRNA, and tissue-free and protein-bound hydroxyproline specific radioactivities 60 min after intravenous administration of a massive dose of [3H]proline. Degradative rates of newly synthesized procollagens and mature collagens were then derived as the difference between rates of procollagen synthesis and collagen accumulation. Left ventricular procollagen synthetic rates were markedly increased after 1 wk of hormone administration (256 +/- 16 and 166 +/- 13 micrograms/day per left ventricle for thyroxine-treated and control animals, respectively; P less than 0.01). An even greater increase in procollagen synthetic rates was observed after 8 wk (438 +/- 46 and 202 +/- 18 micrograms/day for thyroxine-treated and control animals, respectively; P less than 0.01). Despite increased procollagen synthesis, disproportionate accumulation of fibrillar collagens (assessed as the relative concentration of protein-bound hydroxyproline in left ventricular tissue) did not occur. Derived left ventricular degradative rates for newly synthesized procollagens as well as for mature collagens were increased in thyroxine-treated animals. Increased procollagen synthesis, enhanced flux of newly synthesized procollagens through intracellular degradative pathways, and extensive extracellular matrix remodeling without disproportionate collagen accumulation are characteristics of this

  14. Ear Infections

    MedlinePlus

    MENU Return to Web version Ear Infections Overview How does the ear work? A tube called the eustachian (say: "you-stay-shee-an") tube connects the middle ear with the back of the nose. Normally this ...

  15. Cauliflower Ear

    MedlinePlus

    ... Here's Help White House Lunch Recipes What's Cauliflower Ear? KidsHealth > For Kids > What's Cauliflower Ear? Print A A A Text Size Have you ever seen someone whose ear looks bumpy and lumpy? The person might have ...

  16. Swimmer's ear

    MedlinePlus

    ... such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) Vinegar (acetic acid) ear drops People with chronic swimmer's ear may ... drop of alcohol with 1 drop of white vinegar and placing the mixture into the ears after ...

  17. Ear Disorders

    MedlinePlus

    ... ear, where they make your eardrum vibrate. The vibrations are transmitted through three tiny bones, called ossicles, in your middle ear. The vibrations travel to your inner ear, a snail-shaped ...

  18. Lack of collagen VI promotes neurodegeneration by impairing autophagy and inducing apoptosis during aging

    PubMed Central

    Castagnaro, Silvia; Gregorio, Ilaria; Bonaldo, Paolo

    2016-01-01

    Collagen VI is an extracellular matrix (ECM) protein with a broad distribution in different tissues and mostly deposited at the close periphery of the cell surface. Previous studies revealed that collagen VI protects neurons from the toxicity of amyloid-βpeptides and from UV-induced damage. However, the physiological role of this protein in the central nervous system (CNS) remains unknown. Here, we established primary neural cultures from murine cortex and hippocampus, and carried out in vitro and in vivo studies in wild-type and collagen VI null (Col6a1−/−) mice. Col6a1−/− neural cultures displayed an increased incidence of spontaneous apoptosis and higher vulnerability to oxidative stress, accompanied by altered regulation of autophagy with increased p62 protein levels and decreased LC3 lipidation. Analysis of brain sections confirmed increased apoptosis and abnormal regulation of autophagy in the CNS of collagen VI-deficient animals. To investigate the in vivo physiological consequences of these CNS defects, we carried out functional studies and found that motor and memory task performances were impaired in aged Col6a1−/− mice. These findings indicate that lack of collagen VI leads to spontaneous apoptosis and defective autophagy in neural cells, and point at a protective role for this ECM protein in the CNS during physiological aging. PMID:27060109

  19. Lack of collagen VI promotes neurodegeneration by impairing autophagy and inducing apoptosis during aging.

    PubMed

    Cescon, Matilde; Chen, Peiwen; Castagnaro, Silvia; Gregorio, Ilaria; Bonaldo, Paolo

    2016-05-01

    Collagen VI is an extracellular matrix (ECM) protein with a broad distribution in different tissues and mostly deposited at the close periphery of the cell surface. Previous studies revealed that collagen VI protects neurons from the toxicity of amyloid-βpeptides and from UV-induced damage. However, the physiological role of this protein in the central nervous system (CNS) remains unknown. Here, we established primary neural cultures from murine cortex and hippocampus, and carried out in vitro and in vivo studies in wild-type and collagen VI null (Col6a1-/-) mice. Col6a1-/- neural cultures displayed an increased incidence of spontaneous apoptosis and higher vulnerability to oxidative stress, accompanied by altered regulation of autophagy with increased p62 protein levels and decreased LC3 lipidation. Analysis of brain sections confirmed increased apoptosis and abnormal regulation of autophagy in the CNS of collagen VI-deficient animals. To investigate the in vivo physiological consequences of these CNS defects, we carried out functional studies and found that motor and memory task performances were impaired in aged Col6a1-/-mice. These findings indicate that lack of collagen VI leads to spontaneous apoptosis and defective autophagy in neural cells, and point at a protective role for this ECM protein in the CNS during physiological aging. PMID:27060109

  20. Panax ginseng induces human Type I collagen synthesis through activation of Smad signaling.

    PubMed

    Lee, Jongsung; Jung, Eunsun; Lee, Jiyoung; Huh, Sungran; Kim, Jieun; Park, Mijung; So, Jungwoon; Ham, Younggeun; Jung, Kwangseon; Hyun, Chang-Gu; Kim, Yeong Shik; Park, Deokhoon

    2007-01-01

    Skin aging appears to be principally related to a decrease in levels of Type I collagen, the primary component of the dermal layer of skin. It is important to introduce an efficient agent for effective management of skin aging; this agent should have the fewest possible side effects and the greatest wrinkle-reducing effect. In the course of screening collagen production-promoting agents, we obtained Panax ginseng C.A. Meyer. This study was designed to investigate the possible collagen production-promoting activities of Panax ginseng C.A. Meyer root extract (PGRE) in human dermal fibroblast cells. As a first step to this end, human COL1A2 promoter luciferase assay was performed in human dermal fibroblast cells. In this assay, PGRE activated human COL1A2 promoter activity in a concentration-dependent manner. Human Type I procollagen synthesis was also induced by PGRE. These results suggest that PGRE promotes collagen production in human dermal fibroblast cells. Additionally, we have attempted to characterize the mechanism of action of PGRE in Type I procollagen synthesis. PGRE was found to induce the phosphorylation of Smad2, an important transcription factor in the production of Type I procollagen. When applied topically in a human skin primary irritation test, PGRE did not induce any adverse reactions. Therefore, based on these results, we suggest the possibility that PGRE may be considered as an attractive, wrinkle-reducing candidate for topical application. PMID:16890388

  1. 1alpha,25-dihydroxyvitamin D3 rapidly inhibits fibroblast-induced collagen gel contraction.

    PubMed

    Greiling, D; Thieroff-Ekerdt, R

    1996-06-01

    1alpha,25-Dihydroxyvitamin D3 (1,25-D3) inhibits the proliferation of fibroblasts in vitro in monolayer culture. We investigated the effect of 1,25-D3 on normal murine and human fibroblasts cultured in collagen type I gels, which more closely resembles the in vivo situation in the dermis. In this culture system 1,25-D3 had no effect on fibroblast proliferation; however, the fibroblast-induced collagen gel contraction was inhibited in a time- and concentration-dependent manner in the nanomolar concentration range. 25-Hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 were inactive. 1,25-D3 had no effect in fibroblasts lacking a functional vitamin D receptor. Pretreatment of fibroblasts in monolayer culture for 5 min was sufficient to trigger the inhibition of collagen gel contraction. Nifedipine increased collagen gel contraction and counteracted the effect of 1,25-D3. The inhibition of collagen gel contraction by 1,25-D3 is supposed to be mediated by the vitamin D receptor because a functional vitamin D receptor is required, and vitamin D metabolites with low affinity to the vitamin D receptor were inactive. Brief pretreatment of fibroblasts was sufficient to trigger the inhibitory effect of 1,25-D3, suggesting a nongenomic effect. A genomic mode of action could not be ruled out, however, because the inhibition was first measured after 24 h. The antagonism of the calcium channel antagonist nifedipine probably represents the sum of two opposite effects rather than supporting evidence for a nongenomic mode of action of 1,25-D3. In conclusion, 1,25-D3 has a specific and rapidly triggered inhibitory effect on fibroblast-induced collagen gel contraction. PMID:8752663

  2. Impact of Cyclic Stretch on Induced Elastogenesis Within Collagenous Conduits

    PubMed Central

    Venkataraman, Lavanya; Bashur, Chris A.

    2014-01-01

    In vitro tissue engineering of vascular conduits requires a synergy between several external factors, including biochemical supplementation and mechanotranductive stimulation. The goal of this study was to improve adult human vascular smooth muscle cell orientation and elastic matrix synthesis within 3D tubular collagen gel constructs. We used a combination of elastogenic factors (EFs) previously tested in our lab, along with cyclic circumferential strains at low amplitude (2.5%) delivered at a range of frequencies (0.5, 1.5, and 3 Hz). After 21 days of culture, the constructs were analyzed for elastic matrix outcomes, activity of matrix metalloproteinases (MMPs)-2 and −9, cell densities and phenotype, and mechanical properties of constructs. While cell densities remained unaffected by the addition of stretch, contractile phenotypic markers were elevated in all stretched constructs relative to control. Constructs cultured with EFs stretched at 1.5 Hz exhibited the maximum elastin mRNA expression and total matrix elastin (over sixfold vs. the static EFs control). MMP-2 content was comparable in all treatment conditions, but MMP-9 levels were elevated at the higher frequencies (1.5 and 3 Hz). Minimal circumferential orientation was achieved and the mechanical properties remained comparable among the treatment conditions. Overall, constructs treated with EFs and stretched at 1.5 Hz exhibited the most elastogenic outcomes. PMID:24313750

  3. Lipopolysaccharide induces expression of collagen VI in the rat lung.

    PubMed

    Okawa, Sayuri; Unuma, Kana; Yamada, Atsushi; Aki, Toshihiko; Uemura, Koichi

    2015-01-01

    The involvement of the lung during the septic systemic inflammatory response elicited by administration of lipopolysaccharide (LPS) was investigated. Eight-week-old male Sprague-Dawley rats were injected i.p. with 15 mg/kg LPS. After 24 h, the lungs were excised to evaluate the cellular responses to LPS. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) analysis revealed that type VI collagen (ColVI) was extremely upregulated during sepsis in the rat lung within the first 24 h of LPS administration. Upregulation of ColVI protein and its mRNA was demonstrated by Western blot analysis, real time PCR, and immunohistochemistry. To the best of our knowledge, this is the first report demonstrating the activation of ColVI in the rat lung at the early stage of systemic inflammation. Activation of ColVI might be involved in sepsis-mediated lung fibrosis at an early stage. PMID:26023260

  4. Effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis in rats.

    PubMed

    Cannon, G W; McCall, S; Cole, B C; Radov, L A; Ward, J R; Griffiths, M M

    1993-03-01

    The prophylactic and therapeutic effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis (CIA) were evaluated in DA rats. Prophylactic treatment with cyclosporin A and cyclophosphamide suppressed the arthritis incidence, clinical inflammation, destructive bone changes, and development of anti-collagen antibody in DA rats subsequently injected with porcine type-II collagen. Therapeutic treatment with cyclosporin A and cyclophosphamide had a definite suppression on established CIA when started 21 days after the initial collagen injection, but the suppression was less marked than that of prophylactic treatment. Gold had no impact on CIA in DA rats when administered either prophylactically or therapeutically. PMID:8213350

  5. Two-photon induced collagen cross-linking in bioartificial cardiac tissue

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, Kai; Kensah, George; Heidrich, Marko; Meyer, Heiko; Martin, Ulrich; Gruh, Ina; Heisterkamp, Alexander

    2011-08-01

    Cardiac tissue engineering is a promising strategy for regenerative therapies to overcome the shortage of donor organs for transplantation. Besides contractile function, the stiffness of tissue engineered constructs is crucial to generate transplantable tissue surrogates with sufficient mechanical stability to withstand the high pressure present in the heart. Although several collagen cross-linking techniques have proven to be efficient in stabilizing biomaterials, they cannot be applied to cardiac tissue engineering, as cell death occurs in the treated area. Here, we present a novel method using femtosecond (fs) laser pulses to increase the stiffness of collagen-based tissue constructs without impairing cell viability. Raster scanning of the fs laser beam over riboflavin-treated tissue induced collagen cross-linking by two-photon photosensitized singlet oxygen production. One day post-irradiation, stress-strain measurements revealed increased tissue stiffness by around 40% being dependent on the fibroblast content in the tissue. At the same time, cells remained viable and fully functional as demonstrated by fluorescence imaging of cardiomyocyte mitochondrial activity and preservation of active contraction force. Our results indicate that two-photon induced collagen cross-linking has great potential for studying and improving artificially engineered tissue for regenerative therapies.

  6. Exercise prevents β-aminopropionitrile-induced morphological changes to type I collagen in murine bone

    PubMed Central

    Hammond, Max A; Wallace, Joseph M

    2015-01-01

    This study evaluated the effects of reduced enzymatic crosslinking, exercise and the ability of exercise to prevent the deleterious impact of reduced crosslinking on collagen D-spacing. Eight-week-old female mice were divided into four weight-matched groups receiving daily injections of either phosphate-buffered saline (PBS) or 300 mg kg−1 β-aminopropionitrile (BAPN) while undergoing normal cage activity (Sed) or 30 min per day of treadmill exercise (Ex) for 21 consecutive days. BAPN caused a downward shift in the D-spacing distribution in Sed BAPN compared with Sed PBS (P<0.001) but not in Ex BAPN (P=0.429), indicating that exercise can prevent changes in collagen morphology caused by BAPN. Exercise had no effect on D-spacing in PBS control mice (P=0.726), which suggests that exercise-induced increases in lysyl oxidase may be a possible mechanism for preventing BAPN-induced changes in D-spacing. The D-spacing changes were accompanied by an increase in mineral crystallinity/maturity due to the main effect of BAPN (P=0.016). However, no changes in nanoindentation, reference point indentation or other Raman spectroscopy parameters were observed. The ability of exercise to rescue BAPN-driven changes in collagen morphology necessitates further research into the use of mechanical stimulation as a preventative therapy for collagen-based diseases. PMID:25798234

  7. Assessing cisplatin-induced ototoxicity and otoprotection in whole organ culture of the mouse inner ear in simulated microgravity.

    PubMed

    Tropitzsch, Anke; Arnold, Heinz; Bassiouni, Mohamed; Müller, Andrea; Eckhard, Andreas; Müller, Marcus; Löwenheim, Hubert

    2014-06-16

    Cisplatin is a widely used anti-cancer drug. Ototoxicity is a major dose-limiting side-effect. A reproducible mammalian in-vitro model of cisplatin ototoxicity is required to screen and validate otoprotective drug candidates. We utilized a whole organ culture system of the postnatal mouse inner ear in a rotating wall vessel bioreactor under "simulated microgravity" culture conditions. As previously described this system allows whole organ culture of the inner ear and quantitative assessment of ototoxic effects of aminoglycoside induced hair cell loss. Here we demonstrate that this model is also applicable to the assessment of cisplatin induced ototoxicity. In this model cisplatin induced hair cell loss was dose and time dependent. Increasing exposure time of cisplatin led to decreasing EC50 concentrations. Outer hair cells were more susceptible than inner hair cells, and hair cells in the cochlear base were more susceptible than hair cells in the cochlear apex. Initial cisplatin dose determined the final extent of hair cell loss irrespective if the drug was withdrawn or continued. Dose dependant otoprotection was demonstrated by co-administration of the antioxidant agent N-acetyl l-cysteine. The results support the use of this inner ear organ culture system as an in vitro assay and validation platform for inner ear toxicology and the search for otoprotective compounds. PMID:24709139

  8. Libby amphibole-induced mesothelial cell autoantibodies promote collagen deposition in mice.

    PubMed

    Gilmer, John; Serve, Kinta; Davis, Chad; Anthony, Marti; Hanson, Robert; Harding, Tanner; Pfau, Jean C

    2016-06-01

    Libby amphibole (LA) causes a unique progressive lamellar pleural fibrosis (LPF) that is associated with pulmonary function decline. Pleural fibrosis among the LA-exposed population of Libby, MT, has been associated with the production of anti-mesothelial cell autoantibodies (MCAA), which induce collagen production from cultured human mesothelial cells. We hypothesized that the progressive nature of LPF could be at least partially attributed to an autoimmune process and sought to demonstrate that LA-induced MCAA trigger collagen deposition in vivo. C57BL/6 mice were exposed to LA for 7 mo, and serum was tested for MCAA by cell-based ELISA on primary mouse mesothelial cells. When treated in vitro with serum from mice exposed to LA, mesothelial cells upregulated collagen matrix production. This effect was lost when the serum was cleared of IgG using protein G beads, implicating IgG autoantibodies. Using the peritoneal cavity as a surrogate for the pleural cavity, groups of naïve (non-asbestos-exposed) mice were injected intraperitoneally with 1) control serum, 2) one dose of serum from LA-exposed mice (LA serum), 3) two doses of LA serum, or 4) two doses of LA serum cleared of IgG. After 1 mo, analysis of collagen in peritoneal walls using two-photon confocal microscopy (SHG analysis) and a hydroxyproline assay demonstrated significant increases in collagen by LA serum but not control or cleared serum. These data support the hypothesis that MCAA in LA-exposed mice induce fibrotic responses in vivo, demonstrating that an autoimmune component may be contributing to the progressive pleural fibrosis seen in LA-exposed patients. PMID:27106292

  9. Developing functional musculoskeletal tissues through hypoxia and lysyl oxidase-induced collagen cross-linking

    PubMed Central

    Makris, Eleftherios A.; Responte, Donald J.; Hu, Jerry C.; Athanasiou, Kyriacos A.

    2014-01-01

    The inability to recapitulate native tissue biomechanics, especially tensile properties, hinders progress in regenerative medicine. To address this problem, strategies have focused on enhancing collagen production. However, manipulating collagen cross-links, ubiquitous throughout all tissues and conferring mechanical integrity, has been underinvestigated. A series of studies examined the effects of lysyl oxidase (LOX), the enzyme responsible for the formation of collagen cross-links. Hypoxia-induced endogenous LOX was applied in multiple musculoskeletal tissues (i.e., cartilage, meniscus, tendons, ligaments). Results of these studies showed that both native and engineered tissues are enhanced by invoking a mechanism of hypoxia-induced pyridinoline (PYR) cross-links via intermediaries like LOX. Hypoxia was shown to enhance PYR cross-linking 1.4- to 6.4-fold and, concomitantly, to increase the tensile properties of collagen-rich tissues 1.3- to 2.2-fold. Direct administration of exogenous LOX was applied in native cartilage and neocartilage generated using a scaffold-free, self-assembling process of primary chondrocytes. Exogenous LOX was found to enhance native tissue tensile properties 1.9-fold. LOX concentration- and time-dependent increases in PYR content (∼16-fold compared with controls) and tensile properties (approximately fivefold compared with controls) of neocartilage were also detected, resulting in properties on par with native tissue. Finally, in vivo subcutaneous implantation of LOX-treated neocartilage in nude mice promoted further maturation of the neotissue, enhancing tensile and PYR content approximately threefold and 14-fold, respectively, compared with in vitro controls. Collectively, these results provide the first report, to our knowledge, of endogenous (hypoxia-induced) and exogenous LOX applications for promoting collagen cross-linking and improving the tensile properties of a spectrum of native and engineered tissues both in vitro and in

  10. CALCOSPHERULITES* ISOLATED FROM THE MINERALIZATION FRONT OF BONE INDUCE THE MINERALIZATION OF TYPE I COLLAGEN

    PubMed Central

    Midura, Ronald J.; Vasanji, Amit; Su, Xiaowei; Wang, Aimin; Midura, Sharon B.; Gorski, Jeff P.

    2007-01-01

    Previous work has suggested that “calcospherulites” actively participate in the mineralization of developing and healing bone. This study sought to directly test this hypothesis by developing a method to isolate calcospherulites and analyzing their capacity to seed mineralization of fibrillar collagen. The periosteal surface of juvenile rat tibial diaphysis was enriched in spherulites of ~0.5-micron diameter exhibiting a Ca/P ratio of 1.3. Their identity as calcospherulites was confirmed by their uptake of calcein at the tibial mineralization front 24 h following in vivo injection. Periosteum was dissected and unmineralized osteoid removed by collagenase in order to expose calcospherulites. Calcein-labeled calcospherulites were then released from the mineralization front by dispase digestion and isolated via fluorescence flow sorting. X-ray diffraction analysis revealed they contained apatite crystals (c-axis length of 17.5 ± 0.2 nm), though their Ca/P ratio of 1.3 is lower than that of hydroxyapatite. Much of their non-mineral phosphorous content was removed by ice-cold ethanol, elevating their Ca/P ratio to 1.6, suggesting the presence of phospholipids. Western blot analyses showed the presence of bone matrix proteins and type I collagen in these preparations. Incubating isolated calcospherulites in collagen hydrogels demonstrated that they could seed a mineralization reaction on type I collagen fibers in vitro. Ultrastructural analyses revealed crystals on the collagen fibers that were distributed rather uniformly along the fiber lengths. Furthermore, crystals were observed at distances well away from the observed calcospherulites. Our results directly support an active role for calcospherulites in inducing the mineralization of type I collagen fibers at the mineralization front of bone. PMID:17936099

  11. Ear Pieces

    ERIC Educational Resources Information Center

    DiJulio, Betsy

    2011-01-01

    In this article, the author describes an art project wherein students make fanciful connections between art and medicine. This project challenges students to interpret "ear idioms" (e.g. "blow it out your ear," "in one ear and out the other") by relying almost entirely on realistic ear drawings, the placement of them, marks, and values. In that…

  12. Simulating Reflex Induced Changes in the Acoustic Impedance of the Ear.

    ERIC Educational Resources Information Center

    Sirlin, Mindy W.; Levitt, Harry

    1991-01-01

    A simple procedure for measuring changes in the acoustic impedance of the ear is described. The technique has several applications, including simulation using a standard coupler of changes in real ear impedance produced by the acoustic reflex, and calibration of response time of an otoadmittance meter. (Author/DB)

  13. Native Australian plant extracts differentially induce Collagen I and Collagen III in vitro and could be important targets for the development of new wound healing therapies.

    PubMed

    Adams, Damian H; Shou, Qingyao; Wohlmuth, Hans; Cowin, Allison J

    2016-03-01

    Australian native plants have a long history of therapeutic use in indigenous cultures, however, they have been poorly studied scientifically. We analysed the effects of 14 plant derived compounds from the species Pilidiostigma glabrum, Myoporum montanum, Geijera parviflora, and Rhodomyrtus psidioides for their potential wound healing properties by assessing their ability to induce or suppress Collagen I and Collagen III expression in human skin fibroblasts in culture. The compound 7-geranyloxycoumarin was able to significantly increase Collagen I (23.7%, p<0.0002) expression in comparison to control. Significant suppression of Collagen III was observed for the compounds flindersine (11.1%, p<0.02), and (N-acetoxymethyl) flindersine (27%, p<0.00005). The implications of these finding is that these compounds could potentially alter the expression of different collagens in the skin allowing for the potential development of new wound healing therapies and new approaches for treating various skin diseases as well as photo (sun) damaged, and aged skin. PMID:26705840

  14. The effects of experimentally induced conductive hearing loss on spectral and temporal aspects of sound transmission through the ear

    PubMed Central

    Lupo, J. Eric; Koka, Kanthaiah; Thornton, Jennifer L.; Tollin, Daniel J.

    2010-01-01

    Conductive hearing loss (CHL) is known to produce hearing deficits, including deficits in sound localization ability. The differences in sound intensities and timing experienced between the two tympanic membranes are important cues to sound localization (ILD and ITD, respectively). Although much is known about the effect of CHL on hearing levels, little investigation has been conducted into the actual impact of CHL on sound location cues. This study investigated effects of CHL induced by earplugs on cochlear microphonic (CM) amplitude and timing and their corresponding effect on the ILD and ITD location cues. Acoustic and CM measurements were made in 5 chinchillas before and after earplug insertion, and again after earplug removal using pure tones (500 Hz to 24 kHz). ILDs in the unoccluded condition demonstrated position and frequency dependence where peak far-lateral ILDs approached 30 dB for high frequencies. Unoccluded ear ITD cues demonstrated positional and frequency dependence with increased ITD cue for both decreasing frequency (± 420 µs at 500 Hz, ± 310 µs for 1–4 kHz ) and increasingly lateral sound source locations. Occlusion of the ear canal with foam plugs resulted in a mild, frequency-dependent conductive hearing loss of 10–38 dB (mean 31 ± 3.9 dB) leading to a concomitant frequency dependent increase in ILDs at all source locations. The effective ITDs increased in a frequency dependent manner with ear occlusion as a direct result of the acoustic properties of the plugging material, the latter confirmed via acoustical measurements using a model ear canal with varying volumes of acoustic foam. Upon ear plugging with acoustic foam, a mild CHL is induced. Furthermore, the CHL induced by acoustic foam results in substantial changes in the magnitudes of both the ITD and ILD cues to sound location. PMID:21073935

  15. Increased limb involvement in murine collagen-induced arthritis following treatment with anti-interferon-gamma.

    PubMed Central

    Williams, R O; Williams, D G; Feldmann, M; Maini, R N

    1993-01-01

    We have tested the effect of administering H22, a hamster neutralizing MoAb to murine interferon-gamma (IFN-gamma) in collagen-induced arthritis. Mice were immunized with human type II collagen in adjuvant on day 1 and boosted with soluble collagen on day 21. H22 was administered (250 micrograms, intraperitoneally) either during the induction of arthritis (on days 0, 6, 13 and 20) or around the time of disease manifestation (on days 21, 28, 35 and 42). Control mice received either an isotype-matched non-neutralizing MoAb or saline. Both treatment regimes gave similar results. Treatment with H22 did not significantly affect the incidence of arthritis, time of onset, degree of oedema, histopathological severity, or level of anti-type II collagen IgG. However, a highly significant increase (P < 0.01) in the number of limbs affected by arthritis was observed in the H22-treated group, irrespective of whether the antibody was administered during the induction of arthritis, or during the time of clinical manifestation of disease. From these results it was concluded that anti-IFN-gamma treatment caused an increase in the number of arthritic lesions, but did not affect the severity of each individual lesion. PMID:8485917

  16. Embryonic brain extract induces collagen biosynthesis in cultured muscle cells: involvement in acetylcholine receptor aggregation.

    PubMed Central

    Kalcheim, C; Vogel, Z; Duksin, D

    1982-01-01

    The involvement of extracellular matrix components in induction of the aggregation of acetylcholine (AcCho) receptors by factor(s) present in embryonic brain extract was investigated. Embryonic brain extract induced a three-fold increase in the number of AcCho receptor aggregates on the surface of cultured myotubes and a 5- to 10-fold increase in the synthesis of procollagen, which was secreted into the medium and converted to collagen. Adult brain extract, embryonic serum, and embryonic liver extract were less active in stimulating both collagen synthesis and AcCho receptor aggregation. A physiological connection between the two processes is suggested, since the number of AcCho receptor aggregates could be reduced to control levels by treating brain extract-stimulated myotubes with purified bacterial collagenase. In addition, stimulation of collagen secretion by ascorbic acid (50 micrograms/ml) promoted a 1.6-fold increase in AcCho receptor aggregation. When ascorbic acid was added together with the brain extract, further increases in both collagen synthesis and AcCho receptor aggregation were observed. Images PMID:6285338

  17. Inhibition of GSK-3β Alleviates Collagen II-Induced Rheumatoid Arthritis in Rats

    PubMed Central

    Zhou, Haiyan; Liu, Jun; Zeng, Jiashun; Hu, Bailong; Fang, Xiuyi; Li, Long

    2016-01-01

    Background Glycogen synthase kinase-3β (GSK-3β) inhibitor is a serine/threonine kinase with an inhibitory role in glycogen synthesis, which is essential in inflammatory and immunological diseases. The purpose of our study was to determine if TDZD-8 can alleviate collagen II-induced rheumatoid arthritis in rats. Material/Methods Twenty collagen II-induced rheumatoid arthritis rats were treated with selective GSK-3β inhibitor. The effects of GSK-3β inhibition on collagen II-induced rheumatoid arthritis in the rats were evaluated by paw edema, histological examination of arthritic synovium, radiographic examination of knee joint, and the level of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine. The level of cytokines such as IL-6, IL-12, IL-10, and TNF-α, was examined by Elisa. Results GSK-3β inhibitor significantly reduced the development of rheumatoid arthritis in rats. The levels of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine were decreased in the TDZD-8 group. Serum levels of IL-6, IL-12, and TNF-α were significantly reduced in the TDZD-8 group compared with the RA group. Conclusions Treatment with GSK-3β inhibitor suppressed inflammatory response in RA rats. These findings suggest that the inhibition of GSK-3β can be an effective treatment for RA. PMID:27029564

  18. Transgenic Disruption of Glucocorticoid Signaling in Osteoblasts Attenuates Joint Inflammation in Collagen Antibody-Induced Arthritis.

    PubMed

    Tu, Jinwen; Zhang, Yaqing; Kim, Sarah; Wiebe, Edgar; Spies, Cornelia M; Buttgereit, Frank; Cooper, Mark S; Seibel, Markus J; Zhou, Hong

    2016-05-01

    The role of endogenous glucocorticoids (GCs) in rheumatoid arthritis remains unclear. Herein, we examined the role of osteoblastic GC signaling in collagen antibody-induced arthritis. Intracellular GC signaling was abrogated exclusively in mature osteoblasts via transgenic (tg) expression of 11ß-hydroxysteroid dehydrogenase type 2. Arthritis was induced in 8-week-old male tg mice and their wild-type (WT) littermates. Paw swelling was scored daily from induction to end point (day 14). Inflammation, cartilage degradation, and local bone erosion were assessed at the wrist, knee, and ankle joints. Systemic skeletal changes were determined by microcomputed tomography and histomorphometrical analysis of the tibiae. Both tg and WT mice developed acute arthritis in response to the administration of collagen antibodies. However, compared with WT mice, both clinical and histological indexes of joint inflammation were significantly mitigated in animals with disrupted osteoblastic GC signaling. In WT mice, arthritis was associated with increased bone resorption, decreased bone formation, and significant bone loss. In contrast, bone turnover and bone mass remained unchanged in tg arthritic mice. Disruption of GC signaling in osteoblasts significantly reduces joint inflammation and prevents structural bone and cartilage damage in collagen antibody-induced arthritis. These data corroborate the concept that osteoblasts modulate the inflammatory response in immune-mediated arthritis via a GC-dependent pathway. PMID:26988651

  19. Osteoblasts extracellular matrix induces vessel like structures through glycosylated collagen I

    SciTech Connect

    Palmieri, D.; Valli, M.; Viglio, S.; Ferrari, N.; Ledda, B.; Volta, C.; Manduca, P.

    2010-03-10

    Extracellular matrix (ECM) plays a fundamental role in angiogenesis affecting endothelial cells proliferation, migration and differentiation. Vessels-like network formation in vitro is a reliable test to study the inductive effects of ECM on angiogenesis. Here we utilized matrix deposed by osteoblasts as substrate where the molecular and structural complexity of the endogenous ECM is preserved, to test if it induces vessel-like network formation by endothelial cells in vitro. ECM is more similar to the physiological substrate in vivo than other substrates previously utilized for these studies in vitro. Osteogenic ECM, prepared in vitro from mature osteoblasts at the phase of maximal deposition and glycosylation of collagen I, induces EAhy926, HUVEC, and HDMEC endothelial cells to form vessels-like structures and promotes the activation of metalloproteinase-2 (MMP-2); the functionality of the p-38/MAPK signaling pathway is required. Osteogenic ECM also induces a transient increase of CXCL12 and a decrease of the receptor CXCR4. The induction of vessel-like networks is dependent from proper glycosylation of collagens and does not occur on osteogenic ECMs if deglycosylated by -galactosidase or on less glycosylated ECMs derived from preosteoblasts and normal fibroblasts, while is sustained on ECM from osteogenesis imperfecta fibroblasts only when their mutation is associated with over-glycosylation of collagen type I. These data support that post-translational glycosylation has a role in the induction in endothelial cells in vitro of molecules conductive to self-organization in vessels-like structures.

  20. Two-dimensional infrared spectroscopic study on the thermally induced structural changes of glutaraldehyde-crosslinked collagen

    NASA Astrophysics Data System (ADS)

    Tian, Zhenhua; Wu, Kun; Liu, Wentao; Shen, Lirui; Li, Guoying

    2015-04-01

    The thermal stability of collagen solution (5 mg/mL) crosslinked by glutaraldehyde (GTA) [GTA/collagen (w/w) = 0.5] was measured by differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR), and the thermally induced structural changes were analyzed using two-dimensional (2D) correlation spectra. The denaturation temperature (Td) and enthalpy change (ΔH) of crosslinked collagen were respectively about 27 °C and 88 J/g higher than those of native collagen, illuminating the thermal stability increased. With the increase of temperature, the red-shift of absorption bands and the decreased AIII/A1455 value obtained from FTIR spectra indicated that hydrogen bonds were weakened and the unwinding of triple helix occurred for both native and crosslinked collagens; whereas the less changes in red-shifting and AIII/A1455 values for crosslinked collagen also confirmed the increase in thermal stability. Additionally, the 2D correlation analysis provided information about the thermally induced structural changes. In the 2D synchronous spectra, the intensities of auto-peaks at 1655 and 1555 cm-1, respectively assigned to amide I band (Cdbnd O stretching vibration) and amide II band (combination of Nsbnd H bending and Csbnd N stretching vibrations) in helical conformation were weaker for crosslinked collagen than those for native collagen, indicating that the helical structure of crosslinked collagen was less sensitive to temperature. Moreover, the sequence of the band intensity variations showed that the band at 1555 cm-1 moved backwards owing to the addition of GTA, demonstrating that the response of helical structure of crosslinked collagen to the increased temperature lagged. It was speculated that the stabilization of collagen by GTA was due to the reinforcement of triple helical structure.

  1. Two-dimensional infrared spectroscopic study on the thermally induced structural changes of glutaraldehyde-crosslinked collagen.

    PubMed

    Tian, Zhenhua; Wu, Kun; Liu, Wentao; Shen, Lirui; Li, Guoying

    2015-04-01

    The thermal stability of collagen solution (5 mg/mL) crosslinked by glutaraldehyde (GTA) [GTA/collagen (w/w)=0.5] was measured by differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR), and the thermally induced structural changes were analyzed using two-dimensional (2D) correlation spectra. The denaturation temperature (Td) and enthalpy change (ΔH) of crosslinked collagen were respectively about 27°C and 88 J/g higher than those of native collagen, illuminating the thermal stability increased. With the increase of temperature, the red-shift of absorption bands and the decreased AIII/A1455 value obtained from FTIR spectra indicated that hydrogen bonds were weakened and the unwinding of triple helix occurred for both native and crosslinked collagens; whereas the less changes in red-shifting and AIII/A1455 values for crosslinked collagen also confirmed the increase in thermal stability. Additionally, the 2D correlation analysis provided information about the thermally induced structural changes. In the 2D synchronous spectra, the intensities of auto-peaks at 1655 and 1555 cm(-1), respectively assigned to amide I band (CO stretching vibration) and amide II band (combination of NH bending and CN stretching vibrations) in helical conformation were weaker for crosslinked collagen than those for native collagen, indicating that the helical structure of crosslinked collagen was less sensitive to temperature. Moreover, the sequence of the band intensity variations showed that the band at 1555 cm(-1) moved backwards owing to the addition of GTA, demonstrating that the response of helical structure of crosslinked collagen to the increased temperature lagged. It was speculated that the stabilization of collagen by GTA was due to the reinforcement of triple helical structure. PMID:25617846

  2. Anti-PD1-induced collagenous colitis in a melanoma patient.

    PubMed

    Baroudjian, Barouyr; Lourenco, Nelson; Pagès, Cécile; Chami, Ichrak; Maillet, Marianne; Bertheau, Philippe; Bagot, Martine; Gornet, Jean-Marc; Lebbé, Céleste; Allez, Matthieu

    2016-06-01

    Targeted immunotherapy has markedly improved the survival of melanoma patients. We report the case of a melanoma patient who developed a collagenous colitis under an anti-PD1 regimen. A 68-year-old woman was treated for a stage IV melanoma. An anti-PD1, pembrolizumab, was introduced after the failure of a first-line therapy with an anti-CTLA4. At cycle 14, pembrolizumab was interrupted because of grade 3 diarrhea. Histologic analysis of colon mucosa showed a thickened apical subepithelial collagen layer with irregular collagen deposition of more than 25 µm thickness. Budesonide 9 mg/day and cholestyramin 8 g/day were then introduced, leading to a decrease in the number of stools to grade 2. Because of the prognosis of the disease, the efficacy of pembrolizumab in this patient and the lack of other efficient treatments, pembrolizumab was restarted, with no worsening of the diarrhea after a follow-up of 8 weeks. In the era of immunotherapy, a new type of drug-induced colitis has emerged because of monoclonal antibodies targeting immune checkpoints such as CTLA-4 and PD1. Gastrointestinal tract immune-mediated adverse effects are now well described with ipilimumab. To the best of our knowledge, this is the first report of a collagenous colitis in a patient treated with pembrolizumab, thus suggesting a new mechanism of toxicity. Classically, collagenous colitis first-line treatment is based on discontinuation of the suspected treatment. However, there may be a strong benefit to maintaining an anti-PD1 regimen in our patients. In this case, symptomatic management associated with budesonide and cholestyramin enabled continuation of pembrolizumab. PMID:26990271

  3. Probing collagen/enzyme mechanochemistry in native tissue with dynamic, enzyme-induced creep.

    PubMed

    Zareian, Ramin; Church, Kelli P; Saeidi, Nima; Flynn, Brendan P; Beale, John W; Ruberti, Jeffrey W

    2010-06-15

    Mechanical strain or stretch of collagen has been shown to be protective of fibrils against both thermal and enzymatic degradation. The details of this mechanochemical relationship could change our understanding of load-bearing tissue formation, growth, maintenance, and disease in vertebrate animals. However, extracting a quantitative relationship between strain and the rate of enzymatic degradation is extremely difficult in bulk tissue due to confounding diffusion effects. In this investigation, we develop a dynamic, enzyme-induced creep assay and diffusion/reaction rate scaling arguments to extract a lower bound on the relationship between strain and the cutting rate of bacterial collagenase (BC) at low strains. The assay method permits continuous, forced probing of enzyme-induced strain which is very sensitive to degradation rate differences between specimens at low initial strain. The results, obtained on uniaxially loaded strips of bovine corneal tissue (0.1, 0.25, or 0.5 N), demonstrate that small differences in strain alter the enzymatic cutting rate of the BC substantially. It was estimated that a change in tissue elongation of only 1.5% (at approximately 5% strain) reduces the maximum cutting rate of the enzyme by more than half. Estimation of the average load per monomer in the tissue strips indicates that this protective "cutoff" occurs when the collagen monomers are transitioning from an entropic to an energetic mechanical regime. The continuous tracking of the enzymatic cleavage rate as a function of strain during the initial creep response indicates that the decrease in the cleavage rate of the BC is nonlinear (initially steep between 4.5 and 6.5% and then flattens out from 6.5 to 9.5%). The high sensitivity to strain at low strain implies that even lightly loaded collagenous tissue may exhibit significant strain protection. The dynamic, enzyme-induced creep assay described herein has the potential to permit the rapid characterization of collagen

  4. Gene expression profile and synovial microcirculation at early stages of collagen-induced arthritis

    PubMed Central

    Gierer, Philip; Ibrahim, Saleh; Mittlmeier, Thomas; Koczan, Dirk; Moeller, Steffen; Landes, Jürgen; Gradl, Georg; Vollmar, Brigitte

    2005-01-01

    A better understanding of the initial mechanisms that lead to arthritic disease could facilitate development of improved therapeutic strategies. We characterized the synovial microcirculation of knee joints in susceptible mouse strains undergoing intradermal immunization with bovine collagen II in complete Freund's adjuvant to induce arthritis (i.e. collagen-induced arthritis [CIA]). Susceptible DBA1/J and collagen II T-cell receptor transgenic mice were compared with CIA-resistant FVB/NJ mice. Before onset of clinical symptoms of arthritis, in vivo fluorescence microscopy of knee joints revealed marked leucocyte activation and interaction with the endothelial lining of synovial microvessels. This initial inflammatory cell response correlated with the gene expression profile at this disease stage. The majority of the 655 differentially expressed genes belonged to classes of genes that are involved in cell movement and structure, cell cycle and signal transduction, as well as transcription, protein synthesis and metabolism. However, 24 adhesion molecules and chemokine/cytokine genes were identified, some of which are known to contribute to arthritis (e.g. CD44 and neutrophil cytosolic factor 1) and some of which are novel in this respect (e.g. CC chemokine ligand-27 and IL-13 receptor α1). Online in vivo data on synovial tissue microcirculation, together with gene expression profiling, emphasize the potential role played by early inflammatory events in the development of arthritis. PMID:15987489

  5. Molecular basis for T cell response induced by altered peptide ligand of type II collagen.

    PubMed

    Park, Jeoung-Eun; Cullins, David; Zalduondo, Lillian; Barnett, Stacey L; Yi, Ae-Kyung; Kleinau, Sandra; Stuart, John M; Kang, Andrew H; Myers, Linda K

    2012-06-01

    Mounting evidence from animal models has demonstrated that alterations in peptide-MHC interactions with the T cell receptor (TCR) can lead to dramatically different T cell outcomes. We have developed an altered peptide ligand of type II collagen, referred to as A9, which differentially regulates TCR signaling in murine T cells leading to suppression of arthritis in the experimental model of collagen-induced arthritis. This study delineates the T cell signaling pathway used by T cells stimulated by the A9·I-A(q) complex. We have found that T cells activated by A9 bypass the requirement for Zap-70 and CD3-ζ and signal via FcRγ and Syk. Using collagen-specific T cell hybridomas engineered to overexpress either Syk, Zap-70, TCR-FcRγ, or CD3-ζ, we demonstrate that A9·I-A(q) preferentially activates FcRγ/Syk but not CD3-ζ/Zap-70. Moreover, a genetic absence of Syk or FcRγ significantly reduces the altered peptide ligand induction of the nuclear factor GATA3. By dissecting the molecular mechanism of A9-induced T cell signaling we have defined a new alternate pathway that is dependent upon FcRγ and Syk to secrete immunoregulatory cytokines. Given the interest in using Syk inhibitors to treat patients with rheumatoid arthritis, understanding this pathway may be critical for the proper application of this therapy. PMID:22511761

  6. Dense fibrillar collagen is a potent inducer of invadopodia via a specific signaling network

    PubMed Central

    Swatkoski, Stephen; Matsumoto, Kazue; Campbell, Catherine B.; Petrie, Ryan J.; Dimitriadis, Emilios K.; Li, Xin; Mueller, Susette C.; Bugge, Thomas H.; Gucek, Marjan

    2015-01-01

    Cell interactions with the extracellular matrix (ECM) can regulate multiple cellular activities and the matrix itself in dynamic, bidirectional processes. One such process is local proteolytic modification of the ECM. Invadopodia of tumor cells are actin-rich proteolytic protrusions that locally degrade matrix molecules and mediate invasion. We report that a novel high-density fibrillar collagen (HDFC) matrix is a potent inducer of invadopodia, both in carcinoma cell lines and in primary human fibroblasts. In carcinoma cells, HDFC matrix induced formation of invadopodia via a specific integrin signaling pathway that did not require growth factors or even altered gene and protein expression. In contrast, phosphoproteomics identified major changes in a complex phosphosignaling network with kindlin2 serine phosphorylation as a key regulatory element. This kindlin2-dependent signal transduction network was required for efficient induction of invadopodia on dense fibrillar collagen and for local degradation of collagen. This novel phosphosignaling mechanism regulates cell surface invadopodia via kindlin2 for local proteolytic remodeling of the ECM. PMID:25646088

  7. Identification and characterization of a collagen-induced platelet aggregation inhibitor, triplatin, from salivary glands of the assassin bug, Triatoma infestans.

    PubMed

    Morita, Akihiro; Isawa, Haruhiko; Orito, Yuki; Iwanaga, Shiroh; Chinzei, Yasuo; Yuda, Masao

    2006-07-01

    To facilitate feeding, certain hematophagous invertebrates possess inhibitors of collagen-induced platelet aggregation in their saliva. However, their mechanisms of action have not been fully elucidated. Here, we describe two major salivary proteins, triplatin-1 and -2, from the assassin bug, Triatoma infestans, which inhibited platelet aggregation induced by collagen but not by other agents including ADP, arachidonic acid, U46619 and thrombin. Furthermore, these triplatins also inhibited platelet aggregation induced by collagen-related peptide, a specific agonist of the major collagen-signaling receptor glycoprotein (GP)VI. Moreover, triplatin-1 inhibited Fc receptor gamma-chain phosphorylation induced by collagen, which is the first step of GPVI-mediated signaling. These results strongly suggest that triplatins target GPVI and inhibit signal transduction necessary for platelet activation by collagen. This is the first report on the mechanism of action of collagen-induced platelet aggregation inhibitors from hematophagus invertebrates. PMID:16759235

  8. Sialylation converts arthritogenic IgG into inhibitors of collagen-induced arthritis.

    PubMed

    Ohmi, Yuhsuke; Ise, Wataru; Harazono, Akira; Takakura, Daisuke; Fukuyama, Hidehiro; Baba, Yoshihiro; Narazaki, Masashi; Shoda, Hirofumi; Takahashi, Nobunori; Ohkawa, Yuki; Ji, Shuting; Sugiyama, Fumihiro; Fujio, Keishi; Kumanogoh, Atsushi; Yamamoto, Kazuhiko; Kawasaki, Nana; Kurosaki, Tomohiro; Takahashi, Yoshimasa; Furukawa, Koichi

    2016-01-01

    Rheumatoid arthritis (RA)-associated IgG antibodies such as anti-citrullinated protein antibodies (ACPAs) have diverse glycosylation variants; however, key sugar chains modulating the arthritogenic activity of IgG remain to be clarified. Here, we show that reduced sialylation is a common feature of RA-associated IgG in humans and in mouse models of arthritis. Genetically blocking sialylation in activated B cells results in exacerbation of joint inflammation in a collagen-induced arthritis (CIA) model. On the other hand, artificial sialylation of anti-type II collagen antibodies, including ACPAs, not only attenuates arthritogenic activity, but also suppresses the development of CIA in the antibody-infused mice, whereas sialylation of other IgG does not prevent CIA. Thus, our data demonstrate that sialylation levels control the arthritogenicity of RA-associated IgG, presenting a potential target for antigen-specific immunotherapy. PMID:27046227

  9. Ionizing radiations and collagen metabolism: from oxygen free radicals to radio-induced late fibrosis

    NASA Astrophysics Data System (ADS)

    Nguyen, Tan Dat; Maquart, François-Xavier; Monboisse, Jean-Claude

    2005-02-01

    Skin fibrosis is one of the most common late adverse effects observed after radiation therapy for cancer. As a dose-limiting factor and hence a major hindrance to increase the amount of radiation delivered to the tumor, this problem can be addressed according to the very early steps of the fibrotic process: the oxygen free radical production. Reactive oxygen species (ROS) generated during radiotherapy result from both inflammatory response and water radiolysis. Many studies have demonstrated that the extracellular matrix molecules are potential targets for ROS, and that collagen metabolism and properties are deeply and permanently modified after irradiation, both in vitro and in vivo. It is therefore possible to design different therapeutic approaches such as the clinical use of liposomal superoxide dismutase able to reverse the imbalance between collagen matrix synthesis and degradation. Finally, the so-called oxidative stress induced by radiation represents a significant parameter leading to fibrosis and will undoubtedly serve to design further experimental and clinical studies.

  10. Sialylation converts arthritogenic IgG into inhibitors of collagen-induced arthritis

    PubMed Central

    Ohmi, Yuhsuke; Ise, Wataru; Harazono, Akira; Takakura, Daisuke; Fukuyama, Hidehiro; Baba, Yoshihiro; Narazaki, Masashi; Shoda, Hirofumi; Takahashi, Nobunori; Ohkawa, Yuki; Ji, Shuting; Sugiyama, Fumihiro; Fujio, Keishi; Kumanogoh, Atsushi; Yamamoto, Kazuhiko; Kawasaki, Nana; Kurosaki, Tomohiro; Takahashi, Yoshimasa; Furukawa, Koichi

    2016-01-01

    Rheumatoid arthritis (RA)-associated IgG antibodies such as anti-citrullinated protein antibodies (ACPAs) have diverse glycosylation variants; however, key sugar chains modulating the arthritogenic activity of IgG remain to be clarified. Here, we show that reduced sialylation is a common feature of RA-associated IgG in humans and in mouse models of arthritis. Genetically blocking sialylation in activated B cells results in exacerbation of joint inflammation in a collagen-induced arthritis (CIA) model. On the other hand, artificial sialylation of anti-type II collagen antibodies, including ACPAs, not only attenuates arthritogenic activity, but also suppresses the development of CIA in the antibody-infused mice, whereas sialylation of other IgG does not prevent CIA. Thus, our data demonstrate that sialylation levels control the arthritogenicity of RA-associated IgG, presenting a potential target for antigen-specific immunotherapy. PMID:27046227

  11. Ear examination

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003340.htm Ear examination To use the sharing features on this page, ... ear References King EF, Couch ME. History, physical examination, and the preoperative evaluation. In: Flint PW, Haughey ...

  12. Ear wax

    MedlinePlus

    ... water to drain. You may need to repeat irrigation several times. To avoid damaging your ear or ... who may remove the wax by: Repeating the irrigation attempts Suctioning the ear canal Using a small ...

  13. Ear wax

    MedlinePlus

    ... in the ear: Baby oil Commercial drops Glycerin Mineral oil Water Another method is to wash out the ... cloth or paper tissue wrapped around your finger. Mineral oil can be used to moisturize the ear and ...

  14. Your Ears

    MedlinePlus

    ... Protect your hearing by wearing earplugs at loud music concerts and around noisy machinery, like in wood ... For Parents MORE ON THIS TOPIC Can Loud Music Hurt My Ears? What Is an Ear Infection? ...

  15. Ear emergencies

    MedlinePlus

    ... the ear. CUTS ON THE OUTER EAR Apply direct pressure until the bleeding stops. Cover the injury ... Mosby; 2013:chap 143. Thomas SH, Goodloe JM. Foreign bodies. In: Marx JA, Hockberger RS, Walls RM, ...

  16. Loudness changes resulting from an electrically induced middle-ear reflex.

    NASA Technical Reports Server (NTRS)

    Gunn, W. J.

    1973-01-01

    An experiment was conducted in order to determine the changes in loudness brought about by electro-cutaneous elicitation of the middle-ear reflex. Subjects were required to judge the relative loudness of the second of three consecutive 30-msec bursts of tone, the second tone being accompanied by an electrical shock to the external auditory meatus, capable of eliciting a contraction of the middle-ear muscles. The difference between these judgments and those of the control condition (shock on the arm) was taken to represent a measure of the attenuation provided by contraction of the middle-ear muscles. Test tones were 500, 1000, 2000, and 3000 Hz at levels of 65, 75, 85, 95, and 105 dB. The results indicate that the middle-ear reflex decreases the middle-ear's transmission mainly for low-frequency sounds. The results fail to lend support to the Loeb-Riopelle hypothesis that the middle-ear reflex acts as a limiter, rather than a linear attenuator.

  17. Ear barotrauma

    MedlinePlus

    Barotitis media; Barotrauma; Ear popping; Pressure-related ear pain; Eustachian tube dysfunction ... The air pressure in the middle ear is most often the same as the air pressure outside of the body. The Eustachian tube is a connection between the middle ...

  18. Ear Infections

    MedlinePlus

    ... affects the middle ear and is called otitis media. The tubes inside the ears become clogged with fluid and mucus. This can affect hearing, because sound cannot get through all that fluid. If your child isn't old enough to say "My ear ...

  19. Super Ears.

    ERIC Educational Resources Information Center

    Thompson, Stan

    1995-01-01

    Presents an activity in which students design, construct, and test "super ears" to investigate sound and hearing. Students work in groups of three and explore how the outer ear funnels sound waves to the inner ear and how human hearing compares to that of other animals. (NB)

  20. Attenuation of collagen-induced arthritis in mice by salmon proteoglycan.

    PubMed

    Yoshimura, Sayuri; Asano, Krisana; Nakane, Akio

    2014-01-01

    Rheumatoid arthritis (RA) is a serious autoimmune disease caused by chronic inflammation of connective tissues. The basic principle of RA treatment is aimed to reduce joint inflammation. Our previous studies demonstrated that salmon cartilage proteoglycan (PG) suppresses excess inflammation in different mouse inflammatory diseases. In this study, we investigated the prophylactic effect of PG on the progression of RA using an experimental mouse model, collagen-induced arthritis (CIA). Clinical and histological severity of CIA was attenuated by daily oral administration of PG. In the joints of PG-administered mice, infiltration of macrophages and neutrophils and also osteoclast accumulation were limited. In comparison to nonadministered mice, anti-collagen antibodies in the sera of PG-administered mice did not alter. On the other hand, local expression of interleukin-17A (IL-17A), IL-6, IL-1 β, interferon- γ (IFN- γ), C-C chemokine ligand 2 (CCL2), C-X-C chemokine ligand 1 (CXCL1), and CXCL2 in the joints of PG-administered mice decreased. Moreover, in the response of type II collagen- (CII-) restimulation ex vivo, IL-17A and IFN- γ production by splenocytes from PG-administered mice was less than that of control mice. These data suggested that daily ingested PG attenuated CIA pathogenesis by modulating immune response of splenocytes to CII stimulation and local production inflammatory cytokines and chemokines in the joints. PMID:25032213

  1. Libby amphibole-induced mesothelial cell autoantibodies bind to surface plasminogen and alter collagen matrix remodeling.

    PubMed

    Hanson, Robert; Evilia, Caryn; Gilmer, John; Woods, Linda; Black, Brad; Flores, Raja; Pfau, Jean C

    2016-08-01

    Lamellar pleural thickening (LPT) is a fibrotic disease induced by exposure to Libby amphibole (LA) asbestos that causes widespread scarring around the lung, resulting in deterioration of pulmonary function. Investigating the effects of autoantibodies to mesothelial cells (MCAA) present in the study populations has been a major part of the effort to understand the mechanism of pathogenesis. It has been shown in vitro that human mesothelial cells (Met5a) exposed to MCAA increase collagen deposition into the extracellular matrix (ECM). In this study, we sought to further elucidate how MCAA drive increased collagen deposition by identifying the protein targets bound by MCAA on the cellular surface using biotinylation to label and isolate surface proteins. Isolated surface protein fractions were identified as containing MCAA targets using ELISA The fractions that demonstrated binding by MCAA were then analyzed by tandem mass spectrometry (MS/MS) and MASCOT analysis. The most promising result from the MASCOT analysis, plasminogen (PLG), was tested for MCAA binding using purified human PLG in an ELISA We report that serum containing MCAA bound at an optical density (OD) 3 times greater than that of controls, and LA-exposed subjects had a high frequency of positive tests for anti-PLG autoantibodies. This work implicates the involvement of the plasminogen/plasmin system in the mechanism of excess collagen deposition in Met5a cells exposed to MCAA Elucidating this mechanism could contribute to the understanding of LPT. PMID:27519611

  2. Thermally induced irreversible conformational changes in collagen probed by optical second harmonic generation and laser-induced fluorescence.

    PubMed

    Theodossiou, T; Rapti, G S; Hovhannisyan, V; Georgiou, E; Politopoulos, K; Yova, D

    2002-01-01

    Irreversible thermal conformational changes induced to collagen have been studied by optical methods. More specifically, second harmonic generation (SHG) from incident nanosecond Ng:YAG 1064 nm radiation and laser-induced fluorescence by 337 nm, pulsed nanosecond nitrogen laser excitation, at 405, 410 and 415 nm emission wavelengths were registered at eight temperatures (40 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees and 80 degrees C) and normalised with respect to the corresponding values at the ambient temperature of 30 degrees C. The heating protocol used in this work, was selected to monitor only permanent changes reflecting in the optical properties of the samples under investigation. In this context, the SHG, directly related to the collagen fibril population in triple helix conformation, indicated on irreversible phase transition around 64 degrees C. On the other hand fluorescence related to the destruction of cross-linked chromophores in collagen, some of which are related to the triple helix tertiary structure, also indicated a permanent phase transition around 63 degrees C. These results are in agreement with previous results from studies with differential scanning calorimetry. However SHG and fluorescence, being non-invasive optical methods are expected to have a significant impact in the fields of laser ablative surgery and laser tissue welding. PMID:11845366

  3. STAT6-Dependent Collagen Synthesis in Human Fibroblasts Is Induced by Bovine Milk

    PubMed Central

    Kippenberger, Stefan; Zöller, Nadja; Kleemann, Johannes; Müller, Jutta; Kaufmann, Roland; Hofmann, Matthias; Bernd, August; Meissner, Markus; Valesky, Eva

    2015-01-01

    Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids. PMID:26134630

  4. The Aminopeptidase CD13 Induces Homotypic Aggregation in Neutrophils and Impairs Collagen Invasion

    PubMed Central

    Fiddler, Christine A.; Parfrey, Helen; Cowburn, Andrew S.; Luo, Ding; Nash, Gerard B.; Murphy, Gillian; Chilvers, Edwin R.

    2016-01-01

    Aminopeptidase N (CD13) is a widely expressed cell surface metallopeptidase involved in the migration of cancer and endothelial cells. Apart from our demonstration that CD13 modulates the efficacy of tumor necrosis factor-α-induced apoptosis in neutrophils, no other function for CD13 has been ascribed in this cell. We hypothesized that CD13 may be involved in neutrophil migration and/or homotypic aggregation. Using purified human blood neutrophils we confirmed the expression of CD13 on neutrophils and its up-regulation by pro-inflammatory agonists. However, using the anti-CD13 monoclonal antibody WM-15 and the aminopeptidase enzymatic inhibitor bestatin we were unable to demonstrate any direct involvement of CD13 in neutrophil polarisation or chemotaxis. In contrast, IL-8-mediated neutrophil migration in type I collagen gels was significantly impaired by the anti-CD13 monoclonal antibodies WM-15 and MY7. Notably, these antibodies also induced significant homotypic aggregation of neutrophils, which was dependent on CD13 cross-linking and was attenuated by phosphoinositide 3-kinase and extracellular signal-related kinase 1/2 inhibition. Live imaging demonstrated that in WM-15-treated neutrophils, where homotypic aggregation was evident, the number of cells entering IL-8 impregnated collagen I gels was significantly reduced. These data reveal a novel role for CD13 in inducing homotypic aggregation in neutrophils, which results in a transmigration deficiency; this mechanism may be relevant to neutrophil micro-aggregation in vivo. PMID:27467268

  5. STAT6-Dependent Collagen Synthesis in Human Fibroblasts Is Induced by Bovine Milk.

    PubMed

    Kippenberger, Stefan; Zöller, Nadja; Kleemann, Johannes; Müller, Jutta; Kaufmann, Roland; Hofmann, Matthias; Bernd, August; Meissner, Markus; Valesky, Eva

    2015-01-01

    Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids. PMID:26134630

  6. Adenovector-mediated gene delivery to human umbilical cord mesenchymal stromal cells induces inner ear cell phenotype.

    PubMed

    Devarajan, Keerthana; Forrest, M Laird; Detamore, Michael S; Staecker, Hinrich

    2013-02-01

    Hearing is one of our main sensory systems and having a hearing disorder can have a significant impact in an individual's quality of life. Sensory neural hearing loss (SNHL) is the most common form of hearing loss; it results from the degeneration of inner ear sensory hair cells and auditory neurons in the cochlea, cells that are terminally differentiated. Stem cell-and gene delivery-based strategies provide an opportunity for the replacement of these cells. In recent years, there has been an increasing interest in gene delivery to mesenchymal stem cells. In this study, we evaluated the potential of human umbilical cord mesenchymal stromal cells (hUCMSCs) as a possible source for regenerating inner ear hair cells. The expression of Atoh1 induced the differentiation of hUCMSCs into cells that resembled inner ear hair cells morphologically and immunocytochemically, evidenced by the expression of hair cell-specific markers. The results demonstrated for the first time that hUCMSCs can differentiate into hair cell-like cells, thus introducing a new potential tissue engineering and cell transplantation approach for the treatment of hearing loss. PMID:23379581

  7. Human-induced contaminant impacts on migratory birds: lessons from the North American eared grebe (Podiceps nigricollis)

    USGS Publications Warehouse

    Sladky, Kurt K.; Quist, Charlotte; Ramirez, Pedro; Hill, David; Dein, F. Joshua

    2003-01-01

    The effects of aquatic contaminants generated by soda ash mining processes on the North American eared grebe (Podiceps nigricollis) population illustrates important issues associated with human-induced habitat degradation on the health of migratory species. Eared grebes have been extensively studied in their staging and breeding habitats, but little is known about their 2- to 3-day migratory periods. During migration, few bodies of water are available to the birds for refuge between freshwater breeding areas in Canada and hypersaline lakes (e.g., Great Salt Lake in Utah or Mono Lake in California) to which they migrate. One geographic refuge area includes a series of "tailings" ponds associated with soda ash mining operations in southwestern Wyoming. The ponds range from 100-1200 acres, with water containing high concentrations of sodium decahydrate (Na2CO3•10H2O). At cool temperatures (generally < 40°F) sodium decahydrate precipitates out of the water and crystallizes on solid objects in the ponds or on the water surface. Bird mortality on these ponds has been recognized since the early 1970's, and the mining companies have developed hazing strategies and rehabilitation programs in order to minimize mortality. In order to determine causes of grebe mortality and devise strategies to reduce mortality, a field epidemiologic investigation was developed with the following objectives: 1) to determine whether eared grebes have quantifiable physiologic abnormalities associated with exposure to soda ash mine pond water; 2) to evaluate physical effects of sodium decahydrate crystallization on grebe survival; 3) to establish cause of death based on necropsy of deceased grebes; 4) to determine long-term survivability of eared grebes after exposure to the pond water; and 5) to evaluate water quality and determine whether aquatic invertebrates are present in the ponds as a possible food source.

  8. Bisphosphonate-induced osteonecrosis of the external ear canal: a retrospective study.

    PubMed

    Froelich, K; Radeloff, A; Köhler, C; Mlynski, R; Müller, J; Hagen, R; Kleinsasser, N H

    2011-08-01

    In 2003, osteonecrosis of the jaw was described as an intraoral complication of bisphosphonate therapy. More recently, cases of avascular necrosis of the hip were reported in patients with long-lasting bisphosphonate therapy. Thus, it was the aim of the present study to analyze cases of benign osteonecrosis of the external ear canal and to retrospectively identify a possible relationship to long-lasting bisphosphonate therapy. 13 patients with osteonecrosis of the external ear canal operated on between 2005 and 2009 were included. Patient histories were reviewed for possible previous or current bisphosphonate therapy. Three patients with osteonecrosis of the external ear canal and long-term bisphosphonate therapy could be identified. They had been treated either for breast cancer or multiple myeloma. Certainly, the jaw is an area of increased risk for developing osteonecrosis with its high mechanical stress and intraoral bacterial flora. However, osteonecrosis of the hips and the external ear canal in patients receiving long-term bisphosphonate therapy necessitate further investigation of a possible systemic, bisphosphonate-related phenomenon. PMID:21327733

  9. A heterocyclic molecule kartogenin induces collagen synthesis of human dermal fibroblasts by activating the smad4/smad5 pathway.

    PubMed

    Wang, Jing; Zhou, Jia; Zhang, Ning; Zhang, Xiaoling; Li, Qingfeng

    2014-07-18

    Declined production of collagen by fibroblasts is one of the major causes of aging appearance. However, only few of compounds found in cosmetic products are able to directly increase collagen synthesis. A novel small heterocyclic compound called kartogenin (KGN) was found to stimulate collagen synthesis of mesenchymal stem cells (MSCs). So, we hypothesized and tested that if KGN could be applied to stimulate the collagen synthesis of fibroblasts. Human dermal fibroblasts in vitro were treated with various concentrations of KGN, with dimethyl sulfoxide (DMSO) serving as the negative control. Real-time reverse-transcription polymerase chain reaction, Western blot, and immunofluorescence analyses were performed to examine the expression of collagen and transforming growth factor beta (TGF-β) signaling pathway. The production of collagen was also tested in vivo by Masson's trichrome stain and immunohistochemistry in the dermis of mice administrated with KGN. Results showed that without obvious influence on fibroblasts' apoptosis and viability, KGN stimulated type-I collagen synthesis of fibroblasts at the mRNA and protein levels in a time-dependent manner, but KGN did not induce expression of α-skeletal muscle actin (α-sma) or matrix metallopeptidase1 (MMP1), MMP9 in vitro. Smad4/smad5 of the TGF-β signaling pathway was activated by KGN while MAPK signaling pathway remained unchanged. KGN also increased type-I collagen synthesis in the dermis of BALB/C mice. Our results indicated that KGN promoted the type-I collagen synthesis of dermal fibroblasts in vitro and in the dermis of mice through activation of the smad4/smad5 pathway. This molecule could be used in wound healing, tissue engineering of fibroblasts, or aesthetic and reconstructive procedures. PMID:24928394

  10. Collagen-Hydroxyapatite Scaffolds Induce Human Adipose Derived Stem Cells Osteogenic Differentiation In Vitro.

    PubMed

    Calabrese, Giovanna; Giuffrida, Raffaella; Fabbi, Claudia; Figallo, Elisa; Lo Furno, Debora; Gulino, Rosario; Colarossi, Cristina; Fullone, Francesco; Giuffrida, Rosario; Parenti, Rosalba; Memeo, Lorenzo; Forte, Stefano

    2016-01-01

    Mesenchymal stem cells (MSCs) play a crucial role in regulating normal skeletal homeostasis and, in case of injury, in bone healing and reestablishment of skeletal integrity. Recent scientific literature is focused on the development of bone regeneration models where MSCs are combined with biomimetic three-dimensional scaffolds able to direct MSC osteogenesis. In this work the osteogenic potential of human MSCs isolated from adipose tissue (hADSCs) has been evaluated in vitro in combination with collagen/Mg doped hydroxyapatite scaffolds. Results demonstrate the high osteogenic potential of hADSCs when cultured in specific differentiation induction medium, as revealed by the Alizarin Red S staining and gene expression profile analysis. In combination with collagen/hydroxyapatite scaffold, hADSCs differentiate into mature osteoblasts even in the absence of specific inducing factors; nevertheless, the supplement of the factors markedly accelerates the osteogenic process, as confirmed by the expression of specific markers of pre-osteoblast and mature osteoblast stages, such as osterix, osteopontin (also known as bone sialoprotein I), osteocalcin and specific markers of extracellular matrix maturation and mineralization stages, such as ALPL and osteonectin. Hence, the present work demonstrates that the scaffold per se is able to induce hADSCs differentiation, while the addition of osteo-inductive factors produces a significant acceleration of the osteogenic process. This observation makes the use of our model potentially interesting in the field of regenerative medicine for the treatment of bone defects. PMID:26982592

  11. Treatment with SI000413, a new herbal formula, ameliorates murine collagen-induced arthritis.

    PubMed

    Park, Jee-Hun; Lee, Jeong-Min; Kim, Se-Na; Lee, Seung-Ha; Jun, Sung-Hoon; You, Jae-Hoon; Ahn, Kyoo-Seok; Kang, Hee

    2008-07-01

    We tested the effects of SI000413, a new formula, consisting of Pyrolae herba and Trachelospermi caulis, on type II collagen-induced arthritis (CIA). CIA was induced in DBA/1J mice by immunization with bovine type II collagen (CII) on days 1 and 21. SI000413 was orally administered 3 times per week throughout the experiment and indomethacin was served as a positive control. Clinical scores, the count of arthritic legs, levels of interleukin 6 (IL-6) and anti-CII antibody, and lymphocyte subsets in blood were examined. SI000413 suppressed CIA development in a dose dependent manner and reduced the incidence of arthritic legs in mice. Histological analysis showed administration of SI000413 reduced inflammatory signs and cartilage destruction. Serum levels of IL-6 and anti-CII antibody were significantly decreased in SI000413-treated mice and the percentages of CD4 T cell, CD8 T cell and B cell in blood were restored to normal levels. In conclusion, we demonstrate that SI000413 ameliorates CIA both clinically and histologically and inhibits the production of anti-CII antibody and pro-inflammatory cytokine in the CIA mouse. These findings suggest that SI000413 is a potential new therapeutic herbal formula for the treatment of RA. PMID:18591771

  12. Rosiglitazone-mediated dendritic cells ameliorate collagen-induced arthritis in mice.

    PubMed

    Byun, Sei-Hee; Lee, Jun-Ho; Jung, Nam-Chul; Choi, Hyun-Ji; Song, Jie-Young; Seo, Han Geuk; Choi, Jinjung; Jung, Sang Youn; Kang, Sangjin; Choi, Yong-Soo; Chung, Ji Hyung; Lim, Dae-Seog

    2016-09-01

    Rosiglitazone is a selective ligand for peroxisome proliferator-activated receptor-gamma (PPAR-γ), which serves diverse biological functions. A number of autoimmune disease models have been used to examine the anti-inflammatory and immunosuppressive effects of tolerogenic dendritic cells (tDCs). The aim of the present study was to investigate whether rosiglitazone-mediated DC (Rosi-DC) therapy suppressed arthritis in a collagen-induced arthritis (CIA) mouse model. Rosi-DCs were generated by treating immature DCs with TNF-α, type II collagen, and rosiglitazone. CIA mice then received subcutaneously (s.c.) two injections of Rosi-DCs. The severity of arthritis was then assessed histopathologically. The phenotypes of the DC and regulatory T (Treg) cell populations in CIA mice were determined by flow cytometry and the effect of Rosi-DCs on the secretion of autoimmunity-inducing cytokines was examined by ELISA. Rosi-DCs expressed lower levels of DC-related surface markers than mature DCs. Histopathological examination revealed that the degree of inflammation in the paws of Rosi-DC-treated mice was much lower than that in the paws of PBS-treated CIA mice. Taken together, these results clearly show that rosiglitazone-mediated DCs ameliorate CIA, most likely via the induction of antigen-specific Treg cells. PMID:27208887

  13. Collagen-Hydroxyapatite Scaffolds Induce Human Adipose Derived Stem Cells Osteogenic Differentiation In Vitro

    PubMed Central

    Fabbi, Claudia; Figallo, Elisa; Lo Furno, Debora; Gulino, Rosario; Colarossi, Cristina; Fullone, Francesco; Giuffrida, Rosario; Parenti, Rosalba; Memeo, Lorenzo; Forte, Stefano

    2016-01-01

    Mesenchymal stem cells (MSCs) play a crucial role in regulating normal skeletal homeostasis and, in case of injury, in bone healing and reestablishment of skeletal integrity. Recent scientific literature is focused on the development of bone regeneration models where MSCs are combined with biomimetic three-dimensional scaffolds able to direct MSC osteogenesis. In this work the osteogenic potential of human MSCs isolated from adipose tissue (hADSCs) has been evaluated in vitro in combination with collagen/Mg doped hydroxyapatite scaffolds. Results demonstrate the high osteogenic potential of hADSCs when cultured in specific differentiation induction medium, as revealed by the Alizarin Red S staining and gene expression profile analysis. In combination with collagen/hydroxyapatite scaffold, hADSCs differentiate into mature osteoblasts even in the absence of specific inducing factors; nevertheless, the supplement of the factors markedly accelerates the osteogenic process, as confirmed by the expression of specific markers of pre-osteoblast and mature osteoblast stages, such as osterix, osteopontin (also known as bone sialoprotein I), osteocalcin and specific markers of extracellular matrix maturation and mineralization stages, such as ALPL and osteonectin. Hence, the present work demonstrates that the scaffold per se is able to induce hADSCs differentiation, while the addition of osteo-inductive factors produces a significant acceleration of the osteogenic process. This observation makes the use of our model potentially interesting in the field of regenerative medicine for the treatment of bone defects. PMID:26982592

  14. NLRP3 Inflammasome Plays an Important Role in the Pathogenesis of Collagen-Induced Arthritis

    PubMed Central

    Zhang, Yongfeng; Zheng, Yi; Li, Hongbin

    2016-01-01

    Objective. To investigate the relationship between NLRP3 and the pathogenesis of collagen-induced arthritis. Methods. We used the collagen-induced arthritis (CIA) mouse model. The mice were divided into two groups: the model group (CIA, n = 16) and the control group (Normal, n = 8). The mice were sacrificed seven weeks after immunization. The arthritis score and imaging evaluation (X-rays, Micro-CT, and MRI) were performed. Synovial tissue NLRP3 expression and peripheral blood cytokine levels were analyzed. Results. The arthritis score (6.00 ± 2.52), imaging score (4.63 ± 0.92), and synovial tissue NLRP3 expression (4.00 ± 2.03) significantly increased in the CIA mice. The expression of synovial NLRP3 was positively correlated with arthritis clinical and radiographic scores (r = 0.792 and r = 0.669, resp.). Conclusions. The synovial NLRP3 expression increased at the early onset of RA. Synovial NLRP3 expression level was correlated with the clinical arthritis severity and extent of radiological destruction, suggesting that NLRP3 is involved in the pathogenesis of RA. PMID:27034595

  15. Beta-amyrin from Ardisia elliptica Thunb. is more potent than aspirin in inhibiting collagen-induced platelet aggregation.

    PubMed

    Ching, Jianhong; Chua, Tung-Kian; Chin, Lee-Cheng; Lau, Aik-Jiang; Pang, Yun-Keng; Jaya, Johannes Murti; Tan, Chay-Hoon; Koh, Hwee-Ling

    2010-03-01

    Ardisia elliptica Thunberg (Myrsinaceae) is a medicinal plant traditionally used for alleviating chest pains, treatment of fever, diarrhoea, liver poisoning and parturition complications. The objectives of the study were to investigate the effect of A. elliptica on collagen induced platelet aggregation and to isolate and purify potential antiplatelet components. Fresh A. elliptica leaves were extracted using methanol (70% v/v) by Soxhlet extraction and the extract was analysed for its inhibition of collagen-induced platelet aggregation. Inhibition of platelet aggregation was assessed by incubating the extracts with rabbit blood and collagen in a whole blood aggregometer and measuring the impedance. The leaf extract was found to inhibit platelet aggregation with an IC50 value of 167 microg/ml. Using bioassay guided fractionation, beta-amyrin was isolated and purified. The IC50 value of beta-amyrin was found to be 4.5 microg/ml (10.5 microM) while that of aspirin was found to be 11 microg/ml (62.7 microM), indicating that beta-amyrin was six times as active as aspirin in inhibiting platelet aggregation. This paper is the first report that beta-amyrin isolated from A. elliptica is more potent than aspirin in inhibiting collagen-induced platelet aggregation. In conclusion, A. elliptica leaves were found to inhibit collagen-induced platelet aggregation and one of the bioactive components responsible for the observed effect was determined to be beta-amyrin. PMID:21046981

  16. Mobilization of natural killer cells inhibits development of collagen-induced arthritis.

    PubMed

    Leavenworth, Jianmei W; Wang, Xiaoyang; Wenander, Carola Schellack; Spee, Pieter; Cantor, Harvey

    2011-08-30

    Although natural killer (NK) cells have been implicated in regulating immune responses, their ability to modulate disease development in autoimmune arthritis has not been analyzed. Here we investigate the contribution of NK cells to regulating collagen-induced arthritis, a well-characterized preclinical model of human rheumatoid arthritis. We find that the disease is induced by the combined action of two CD4(+) T helper (T(H)) subsets: follicular T(H) cells and T(H)17 cells. Both CD4(+) T(H) subsets are highly susceptible to lysis by NK cells after activation. Administration of antibody that activates NK cells through blockade of its inhibitory CD94/NKG2A receptor allows enhanced elimination of pathogenic follicular T(H) and T(H)17 cells and arrest of disease progression. These results suggest that antibody-dependent enhancement of NK activity may yield effective, previously undescribed therapeutic approaches to this autoimmune disorder. PMID:21873193

  17. Changes in collagen fibril pattern and adhesion force with collagenase-induced injury in rat Achilles tendon observed via AFM.

    PubMed

    Lee, Gi-Ja; Choi, Samjin; Chon, Jinmann; Yoo, Seungdon; Cho, Ilsung; Park, Hun-Kuk

    2011-01-01

    The Achilles tendon consists mainly of type I collagen fibers that contain collagen fibrils. When the Achilles tendon is injured, it is inflamed. The collagenase-induced model has been widely used to study tendinitis. The major advantages of atomic force microscopy (AFM) over conventional optical and electron microscopy for bio-imaging include its non-requirement of a special coating and vacuum, and its capability to perform imaging in all environments. AFM force-distance measurements have become a fundamental tool in the fields of surface chemistry, biochemistry and materials science. Therefore, the changes in the ultrastructure and adhesion force of the collagen fibrils on the Achilles tendons of rats with Achilles tendinitis were observed using AFM. The changes in the structure of the Achilles tendons were evaluated based on the diameter and D-banding of the collagen fibrils. Collagenase-induced Achilles tendinitis was induced with the injection of 30 microl crude collagenase into 7-week-old male Sprague-Dawley rats. The animals were each sacrificed on the first, second, third, fifth and seventh day after the collagenase injection. The normal and injured Achilles tendons were fixed in 4% buffered formalin and dehydrated with increasing concentrations of ethanol. AFM was performed using the non-contact mode at the resolution of 512 x 512 pixels, with a scan speed of 0.8 line/sec. The adhesion force was measured via the force-distance curve that resulted from the interactions between the AFM tip and the collagen fibril sample using the contact mode. The diameter of the collagen fibrils in the Achilles tendons significantly decreased (p < 0.05) after the collagenase injection, and the pattern of the D-banding of the collagen fibrils was similar to that of the diameter changes. The adhesion force decreased until the fifth day after the collagenase injection, but increased on the seventh day after the collagenase injection (p < 0.0001). PMID:21446543

  18. Ear Problems

    MedlinePlus

    ... this condition. Try an over-the-counter decongestant medicine for a few days. Putting a warm heating pad on your ear may help relieve the pain. If the pain is intense or doesn't go away in 1 or 2 days, see your doctor. No 9. Do you have tooth pain on the same side as the ear ...

  19. Elephant ear

    MedlinePlus

    Elephant ear plants are indoor or outdoor plants with very large, arrow-shaped leaves. Poisoning may occur if you ... The harmful substances in elephant ear plants are: Oxalic acid ... plant Note: Leaves and stems are the most dangerous when eaten ...

  20. [Sonic hedgehog (SHH) promotes the proliferation of synovial fibroblasts of rats with collagen-induced arthritis].

    PubMed

    Li, Hui; Qin, Suping; Sun, Dexu; Pan, Wei; Li, Xiangyang; Kong, Fanyun; Zhen, Kuiyang; Tang, Renxian

    2016-05-01

    Objective To investigate the effect of sonic hedgehog (SHH) on the proliferation of synovial fibroblasts (SFs). Methods The serum samples were collected from 30 rheumatoid arthritis (RA) patients, 30 systemic lupus erythematosus (SLE) patients, 30 ankylosing spondylitis (AS) patients and 30 healthy subjects. The concentrations of serum SHH were detected by ELISA. Collagen induced arthritis (CIA) were developed by type 2 collagen in Sprague-Dawley rats. The SFs were isolated from knee synovial tissues of CIA rats, and then identified by the detection of vimentin by immunofluorescence technique. Before and 72 hours after blocking SHH-glioma-associated oncogene 1 (Gli-1) signaling pathway with GANT61, the expression level of SHH in SFs was detected by Western blotting, and the proliferation of SFs was examined with CCK-8 assay. Results The level of serum SHH in the RA patients was remarkably higher than that in the SLE, AS patients and the healthy controls. In the CIA rats, the expression of SHH in SFs in vitro was higher than that in the healthy control rats. After 72-hour treatment of GANT61 to block SHH-Gli-1 signaling pathway, the expression level of SHH protein in SFs from CIA rats was reduced, and meanwhile the proliferation of the SFs was inhibited. Conclusion SHH plays an important role in the proliferation of SFs and could be used as a potential therapeutic target for RA. PMID:27126942

  1. Metabolomics analysis of collagen-induced arthritis in rats and interventional effects of oral tolerance.

    PubMed

    Ding, Xinghong; Hu, Jinbo; Li, Jinfeng; Zhang, Yan; Shui, Bingjie; Ding, Zhishan; Yao, Li; Fan, Yongsheng

    2014-08-01

    A serum metabolomics method based on rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RRLC-Q-TOF-MS) was performed for a holistic evaluation of the metabolic changes of collagen-induced arthritis (CIA) in rats and to assess the interventional effects of type II collagen (CII) in this model. Partial least-squares-discriminant analysis (PLS-DA) was employed to study the metabolic profiling of CIA rats and control rats. Ten metabolites, namely, 12(S)-HHTrE, 12(S)-HEPE, PGE2, TXB2, 12(S)-HETE, LysoPE(16:0), PE(O-18:0/0:0), Lyso-PE(18:2), Lyso-PE(20:4), and Lyso-PC(22:5) were identified as differential metabolites associated with the pathogenesis of CIA. These results suggested that dysregulation of the arachidonic acid (AA) and phospholipid metabolic networks is involved in the pathomechanism of CIA. Differential metabolomics and histopathological analyses demonstrated that CII inhibits the progress of arthritis. Furthermore, the therapeutic effects of CII on CIA may involve regulation of the disordered AA and phospholipid metabolic networks. This metabolomics study provides new insights into the pathogenesis of arthritis and, furthermore, indicates the potential mechanism underlying the significantly increased prevalence of metabolic syndrome, defined as a clustering of cardiovascular disease (CVD) risk factors, in arthritis patients. PMID:24814225

  2. Adiponectin exacerbates collagen-induced arthritis via enhancing Th17 response and prompting RANKL expression.

    PubMed

    Sun, Xiaoxuan; Feng, Xiaoke; Tan, Wenfeng; Lin, Na; Hua, Minhui; Wei, Yu; Wang, Fang; Li, Ningli; Zhang, Miaojia

    2015-01-01

    We previously reported adiponectin (AD) is highly expressed in the inflamed synovial joint tissue and correlates closely with progressive bone erosion in Rheumatoid arthritis (RA) patients. Here, we investigate the role of adiponectin in regulating Th17 response and the expression of receptor activator of nuclear factor-κB ligand (RANKL) in mice with CIA mice by intraarticularly injection of adiponectin into knee joints on day 17, day 20 and day 23 post first collagen immunization. The increased adiponectin expression was found in inflamed joint tissue of collagen-induced arthritis (CIA) mice. Adiponectin injection resulted in an earlier onset of arthritis, an aggravated arthritic progression, more severe synovial hyperplasia, bone erosion and osteoporosis in CIA mice. CD4(+)IL-17(+) Th17 cells, IL-17 mRNA and RANKL mRNA expression were markedly increased in the joint tissue of adiponectin treated CIA mice. Moreover, adiponectin treatment markedly enhanced Th17 cell generation from naive CD4(+) T cells in vitro, which accompanied by the high expression of Th17 transcription factor ROR-γt, and Th17 cytokine genes included IL-22 and IL-23. This study reveals a novel effect of adiponectin in exacerbating CIA progression by enhancing Th17 cell response and RANKL expression. PMID:26063682

  3. The role of lipopolysaccharide injected systemically in the reactivation of collagen-induced arthritis in mice

    PubMed Central

    Yoshino, Shin; Ohsawa, Motoyasu

    2000-01-01

    We investigated the role of bacterial lipopolysaccharide (LPS) in the reactivation of autoimmune disease by using collagen-induced arthritis (CIA) in mice in which autoimmunity to the joint cartilage component type II collagen (CII) was involved.CIA was induced by immunization with CII emulsified with complete Freund's adjuvant at the base of the tail (day 0) followed by a booster injection on day 21. Varying doses of LPS from E. coli were i.p. injected on day 50.Arthritis began to develop on day 25 after immunization with CII and reached a peak on day 35. Thereafter, arthritis subsided gradually but moderate joint inflammation was still observed on day 50. An i.p. injection of LPS on day 50 markedly reactivated arthritis on a dose-related fashion. Histologically, on day 55, there were marked oedema of synovium which had proliferated by the day of LPS injection, new formation of fibrin, and intense infiltration of neutrophils accompanied with a large number of mononuclear cells. The reactivation of CIA by LPS was associated with increases in anti-CII IgG and IgG2a antibodies as well as various cytokines including IL-12, IFN-γ, IL-1β, and TNF-α. LPS from S. enteritidis, S. typhimurium, and K. neumoniae and its component, lipid A from E. coli also reactivated the disease. Polymyxin B sulphate suppressed LPS- or lipid A-induced reactivation of CIA.These results suggest that LPS may play an important role in the reactivation of autoimmune joint inflammatory diseases such as rheumatoid arthritis in humans. PMID:10742285

  4. Boswellia serrata extract attenuates inflammatory mediators and oxidative stress in collagen induced arthritis.

    PubMed

    Umar, Sadiq; Umar, Khalid; Sarwar, Abu Hasnath Md Golam; Khan, Altaf; Ahmad, Niyaz; Ahmad, Sayeed; Katiyar, Chandra Kant; Husain, Syed Akhtar; Khan, Haider A

    2014-05-15

    Rheumatoid arthritis (RA) is a chronic inflammatory disease which leads to destruction of joints. Current treatment modalities for RA either produce symptomatic relief (NSAIDs) or modify the disease process (DMARDs). Though effective, their use is also limited by their side effects. As a result, the interest in alternative, well tolerated anti-inflammatory remedies has re-emerged. Our aim was to evaluate the antioxidant and antiarthritic activity of Boswellia serrata gum resin extract (BSE) in collagen induced arthritis. Arthritis was induced in male Wistar rats by collagen induced arthritis (CIA) method. BSE was administered at doses of 100 and 200mg/kg body weight once daily for 21 days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, catalase, SOD and NO), inflammatory mediators (IL-1β, IL-6, TNF-α, IL-10, IFN-γ and PGE2), and histological studies in joints. BSE was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, catalase, SOD and NO) studied. Oral administration of BSE resulted in significantly reduced levels of inflammatory mediators (IL-1β, IL-6, TNF-α, IFN-γ and PGE2), and increased level of IL-10. The protective effects of BSE against RA were also evident from the decrease in arthritis scoring and bone histology. The abilities to inhibit proinflammatory cytokines and modulation of antioxidant status suggest that the protective effect of Boswellia serrata extract on arthritis in rats might be mediated via the modulation of immune system. PMID:24667331

  5. Keratocytes are induced to produce collagen type II: A new strategy for in vivo corneal matrix regeneration.

    PubMed

    Greene, Carol Ann; Green, Colin R; Dickinson, Michelle E; Johnson, Virginia; Sherwin, Trevor

    2016-09-10

    The stroma, the middle layer of the cornea, is a connective tissue making up most of the corneal thickness. The stromal extracellular matrix (ECM) consists of highly organised lamellae which are made up of tightly packed fibrils primarily composed of collagens type I and V. This layer is interspersed with keratocytes, mesenchymal cells of neural crest origin. We have previously shown that adult corneal keratocytes exhibit phenotypic plasticity and can be induced into a neuronal phenotype. In the current study we evaluated the potential of keratocytes to produce collagen type II via phenotypic reprogramming with exogenous chondrogenic factors. The cornea presents a challenge to tissue engineers owing to its high level of organisation and the phenotypic instability of keratocytes. Traditional approaches based on a scar model do not support the engineering of functional stromal tissue. Type II collagen is not found in the adult cornea but is reported to be expressed during corneal development, raising the possibility of using such an approach to regenerate the corneal ECM. Keratocytes in culture and within intact normal and diseased tissue were induced to produce collagen type II upon treatment with transforming growth factor Beta3 (TGFβ3) and dexamethasone. In vivo treatment of rat corneas also resulted in collagen type II deposition and a threefold increase in corneal hardness and elasticity. Furthermore, the treatment of corneas and subsequent deposition of collagen type II did not cause opacity, fibrosis or scarring. The induction of keratocytes with specific exogenous factors and resulting deposition of type II collagen in the stroma can potentially be controlled by withdrawal of the factors. This might be a promising new approach for in vivo corneal regeneration strategies aimed at increasing corneal integrity in diseases associated with weakened ectatic corneal tissue such as keratoconus. PMID:27539660

  6. Identification of a major quantitative trait locus for ear size induced by space flight in sweet corn.

    PubMed

    Yu, Y T; Li, G K; Yang, Z L; Hu, J G; Zheng, J R; Qi, X T

    2014-01-01

    The development of molecular markers has contributed to progress in identifying the gene(s) responsible for favorable variations in maize studies. In this study, quantitative trait locus (QTL) mapping was conducted using simple sequence repeat markers in an F2 sweet corn population from a cross between parental line 1132 and space flight-induced mutant line 751 to identify the loci contributing to an increase in some yield traits. A primary mutated genomic region was located on chromosome 9. In total, 26 QTL were detected for eight yield-related traits and assembled into three clusters on chromosome 9. The largest QTL cluster at bin 9.02/03, primarily contributing to >10% of the phenotypic variation in ear and cob diameters, was likely due to a major QTL. Desired alleles of these QTL were provided by the mutant line 751. The primary action of the major mutant allele was an additive effect. Another mutant locus, which was induced in bin 9.01, increased cob and ear diameters by dominant genetic action. PMID:24782164

  7. Recombinant Human Decorin Inhibits TGF-b1 Induced Contraction of Collagen Lattice by Keloid Fibroblasts.

    PubMed

    Zhang, Zhi; Garron, Tania; Li, Xiao-Jian; Liu, Yan; Zhang, Xiong; Li, Ye-Yang; Xu, Wei-Shi

    2009-02-01

    While wound contraction plays an important role in healing, it may lead to excessive scar formation and pathological wound contracture in extreme conditions. To date, the key regulator of wound contraction and keloid formation is transforming growth factor-beta (TGF-b1). Decorin has been reported to bind TGF-b1 and neutralize some of its activities. The present study investigated whether decorin affected TGF-b1-induced fibroblast contractile activity by using fibroblast-populated collagen lattice (FPCL), which has been generally used as an in-vitro model thought to mimic wound contraction in vivo, modified by the incorporation of recombinant human decorin into collagen gel. As expected, TGF-b1 significantly enhanced the contraction of collagen gel at hour 12, 24, 48, 72, and 96 (P < 0.05). Recombinant human decorin inhibited both the basal and TGF-b1-enhanced contraction of collagen gel by keloid fibroblasts (P < 0.05). These inhibitory effects of recombinant human decorin were associated with suppression of TGF-b1-induced filamentous actin (F-actin) expression in keloid fibroblasts. Furthermore, recombinant human decorin inhibited TGF-b1 induced a-smooth muscle actin (a-SMA), PAI-1 (plasminogen activator inhibitor-1) protein, and mRNA expressions in keloid fibroblasts (P < 0.05). These data indicate that recombinant human decorin can suppress TGF-b1-induced contraction of collagen gel by keloid fibroblasts. Moreover, decorin can inhibit basal contraction of collagen gel by keloid fibroblasts. These results suggest that decorin may have therapeutic potential for excessive skin contraction as observed in a keloid. . PMID:25903025

  8. Triplex Forming Oligonucleotides against Type α 1(I) Collagen attenuates Liver Fibrosis induced by Bile Duct ligation

    PubMed Central

    Panakanti, Ravikiran; Pratap, Akshay; Yang, Ningning; Jackson, John S.; Mahato, Ram I.

    2010-01-01

    Liver fibrosis is a consequence of chronic liver disorders which lead to the accumulation of extracellular matrix (ECM). Particularly, there is an increased accumulation of collagen in the fibrotic liver. We have therefore used a triplex forming oligonucleotide (TFO) against the type α 1 (I) collagen and evaluated, whether it can attenuate liver fibrosis induced by common bile duct ligation (CBDL) in rats. There was a significant decrease in hydroxyproline levels and Masson’s trichrome staining for collagen in TFO-treated CBDL groups compared to non-treated CBDL group. There was over expression of type α1(I) collagen, α-smooth muscle actin (α-SMA) and TGF-β1 expression in the CBDL group compared to TFO-treated CBDL group. Also, the serum alanine transaminase (ALT) and aspartate transaminase (AST) concentrations were less in the TFO treated group compared to non-treated CBDL group. There was also less neutrophils accumulation in TFO treated CBDL group assayed by myeloperoxidase (MPO) assay. These results suggests that TFO can be used to downregulate type 1 collagen gene expression and can alleviate liver fibrosis induced by common bile duct ligation. PMID:20816672

  9. Collagen Induces Maturation of Human Monocyte-Derived Dendritic Cells by Signaling through Osteoclast-Associated Receptor

    PubMed Central

    Schultz, Heidi S.; Nitze, Louise M.; Zeuthen, Louise H.; Keller, Pernille; Gruhler, Albrecht; Pass, Jesper; Chen, Jianhe; Guo, Li; Fleetwood, Andrew J.; Hamilton, John A.; Berchtold, Martin W.

    2015-01-01

    Osteoclast-associated receptor (OSCAR) is widely expressed on human myeloid cells. Collagen types (Col)I, II, and III have been described as OSCAR ligands, and ColII peptides can induce costimulatory signaling in receptor activator for NF-κB–dependent osteoclastogenesis. In this study, we isolated collagen as an OSCAR-interacting protein from the membranes of murine osteoblasts. We have investigated a functional outcome of the OSCAR–collagen interaction in human monocyte-derived dendritic cells (DCs). OSCAR engagement by ColI/II-induced activation/maturation of DCs is characterized by upregulation of cell surface markers and secretion of cytokines. These collagen-matured DCs (Col-DCs) were efficient drivers of allogeneic and autologous naive T cell proliferation. The T cells expanded by Col-DCs secreted cytokines with no clear T cell polarization pattern. Global RNA profiling revealed that multiple proinflammatory mediators, including cytokines and cytokine receptors, components of the stable immune synapse (namely CD40, CD86, CD80, and ICAM-1), as well as components of TNF and TLR signaling, are transcriptional targets of OSCAR in DCs. Our findings indicate the existence of a novel pathway by which extracellular matrix proteins locally drive maturation of DCs during inflammatory conditions, for example, within synovial tissue of rheumatoid arthritis patients, where collagens become exposed during tissue remodeling and are thus accessible for interaction with infiltrating precursors of DCs. PMID:25725106

  10. Alignment and assembly of adsorbed collagen molecules induced by anisotropic chemical nanopatterns.

    PubMed

    Denis, Frédéric A; Pallandre, Antoine; Nysten, Bernard; Jonas, Alain M; Dupont-Gillain, Christine C

    2005-10-01

    Collagen, a protein widely used to control cell-material interactions, is known to self-assemble in solution. Supramolecular structures also form on material surfaces following collagen adsorption. Herein, we report the use of anisotropic, flat, surface chemical nanopatterns, which consist of alkyl-terminated tracks drawn in an oligo(ethylene glycol)-terminated matrix, to direct collagen adsorption. As revealed by atomic force microscopy, the spontaneous collagen adsorption performed on such patterned substrates results in the accumulation of collagen on the hydrophobic tracks. Moreover, the width of the tracks (30-90 nm), which is much smaller than the length of the collagen molecule (approximately 300 nm), is the origin of preferential alignment of the molecules and of their assembly into continuous bundles of adsorbed collagen. This chemical guidance effect due to self-confinement of proteins upon adsorption may bring novel and valuable applications, specifically in biomaterials science and cell growth control. PMID:17193383

  11. Epithelial derived CTGF promotes breast tumor progression via inducing EMT and collagen I fibers deposition

    PubMed Central

    Zhao, Zhen; Sheng, Jianting; Wang, Jiang; Liu, Jiyong; Cui, Kemi; Chang, Jenny; Zhao, Hong; Wong, Stephen

    2015-01-01

    Interactions among tumor cells, stromal cells, and extracellular matrix compositions are mediated through cytokines during tumor progression. Our analysis of 132 known cytokines and growth factors in published clinical breast cohorts and our 84 patient-derived xenograft models revealed that the elevated connective tissue growth factor (CTGF) in tumor epithelial cells significantly correlated with poor clinical prognosis and outcomes. CTGF was able to induce tumor cell epithelial-mesenchymal transition (EMT), and promote stroma deposition of collagen I fibers to stimulate tumor growth and metastasis. This process was mediated through CTGF-tumor necrosis factor receptor I (TNFR1)-IκB autocrine signaling. Drug treatments targeting CTGF, TNFR1, and IκB signaling each prohibited the EMT and tumor progression. PMID:26318291

  12. Anti-arthritic effect of eugenol on collagen-induced arthritis experimental model.

    PubMed

    Grespan, Renata; Paludo, Marcia; Lemos, Henrique de Paula; Barbosa, Carmem Patrícia; Bersani-Amado, Ciomar Aparecida; Dalalio, Marcia Machado de Oliveira; Cuman, Roberto Kenji Nakamura

    2012-01-01

    This study was designed to test the efficacy of eugenol, a compound obtained from the essential oil of cloves (Syzygium aromaticum) in collagen-induced arthritis (CIA), a well characterized murine model of rheumatoid arthritis. Macroscopic clinical evidence of CIA manifests first as periarticular erythema and edema in the hind paws. Treatment with eugenol starting at the onset of arthritis (day 25) ameliorated these clinical signs of CIA. Furthermore, eugenol inhibited mononuclear cell infiltration into the knee joints of arthritic mice and also lowered the levels of cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-γ and tumor growth factor (TGF)-β) within the ankle joints. Eugenol treatment did not affect the in vitro cell viability as assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Therefore, eugenol ameliorates experimental arthritis and could be useful as a beneficial supplement in treating human arthritis. PMID:23037170

  13. Collagen-induced binding to human platelets of platelet-derived growth factor leading to inhibition of P43 and P20 phosphorylation

    SciTech Connect

    Bryckaert, M.C.; Rendu, F.; Tobelem, G.; Wasteson, A.

    1989-03-15

    Platelet-derived growth factor (PDGF) is known to inhibit collagen-induced platelet aggregation. Collagen-induced binding of /sup 125/I-PDGF to human washed platelets was therefore investigated. It was found to be time-dependent, reaching a plateau at 20 degrees C after 30 min, collagen concentration-dependent, specifically inhibited by unlabeled PDGF, and saturable. Scatchard plot analysis showed a single class of sites with 3000 +/- 450 molecules bound/cell and an apparent KD of 1.2 +/- 0.2 10(-8) M. The effects of PDGF on collagen-induced phosphoinositide breakdown and protein phosphorylation were also investigated. At 50 ng/ml PDGF, a concentration which completely inhibited collagen-induced aggregation, the breakdown of (/sup 32/P)phosphatidylinositol 4,5-biphosphate (PIP2) and (/sup 32/P)phosphatidylinositol 4-phosphate (PIP) was observed, but the subsequent replenishment of (/sup 32/P)PIP2 was inhibited. The same PDGF concentration totally inhibited collagen-induced phosphatidic acid formation. PDGF also completely prevented phosphorylation of P43 and P20, as a result of protein kinase C activation consecutive to phosphoinositide metabolism. These results suggest that a specific PDGF receptor can be induced by collagen, and PDGF can effect the early events of collagen-induced platelet activation by inhibiting PIP2 resynthesis and P43 and P20 phosphorylation. It is concluded that PDGF might be involved in a negative feed-back control of platelet activation.

  14. Vascular pentraxin 3 controls arterial thrombosis by targeting collagen and fibrinogen induced platelets aggregation

    PubMed Central

    Bonacina, F.; Barbieri, S.S.; Cutuli, L.; Amadio, P.; Doni, A.; Sironi, M.; Tartari, S.; Mantovani, A.; Bottazzi, B.; Garlanda, C.; Tremoli, E.; Catapano, A.L.; Norata, G.D.

    2016-01-01

    Aim The long pentraxin PTX3 plays a non-redundant role during acute myocardial infarction, atherosclerosis and in the orchestration of tissue repair and remodeling during vascular injury, clotting and fibrin deposition. The aim of this work is to investigate the molecular mechanisms underlying the protective role of PTX3 during arterial thrombosis. Methods and results PTX3 KO mice transplanted with bone marrow from WT or PTX3 KO mice presented a significant reduction in carotid artery blood flow following FeCl3 induced arterial thrombosis (− 80.36 ± 11.5% and − 95.53 ± 4.46%), while in WT mice transplanted with bone marrow from either WT or PTX3 KO mice, the reduction was less dramatic (− 45.55 ± 1.37% and − 53.39 ± 9.8%), thus pointing to a protective effect independent of a hematopoietic cell's derived PTX3. By using P-selectin/PTX3 double KO mice, we further excluded a role for P-selectin, a target of PTX3 released by neutrophils, in vascular protection played by PTX3. In agreement with a minor role for hematopoietic cell-derived PTX3, platelet activation (assessed by flow cytometric expression of markers of platelet activation) was similar in PTX3 KO and WT mice as were haemostatic properties. Histological analysis indicated that PTX3 localizes within the thrombus and the vessel wall, and specific experiments with the N-terminal and the C-terminal PTX3 domain showed the ability of PTX3 to selectively dampen either fibrinogen or collagen induced platelet adhesion and aggregation. Conclusion PTX3 interacts with fibrinogen and collagen and, by dampening their pro-thrombotic effects, plays a protective role during arterial thrombosis. PMID:26976330

  15. Age-Related Differences in Collagen-Induced Arthritis: Clinical and Imaging Correlations

    PubMed Central

    Wilson-Gerwing, Tracy D; Pratt, Isaac V; Cooper, David M L; Silver, Tawni I; Rosenberg, Alan M

    2013-01-01

    Arthritis is among the most common chronic diseases in both children and adults. Although intraarticular inflammation is the feature common among all patients with chronic arthritis there are, in addition to age at onset, clinical characteristics that further distinguish the disease in pediatric and adult populations. In this study, we aimed to demonstrate the utility of microCT (µCT) and ultrasonography in characterizing pathologic age-related differences in a collagen-induced arthritis (CIA) rat model. Juvenile (35 d old) and young adult (91 d old) male Wistar rats were immunized with bovine type II collagen and incomplete Freund adjuvant to induce polyarthritis. Naïve male Wistar rats served as controls. All paws were scored on a scale of 0 (normal paw) to 4 (disuse of paw). Rats were euthanized at 14 d after the onset of arthritis and the hindpaws imaged by µCT and ultrasonography. Young adult rats had more severe signs of arthritis than did their juvenile counterparts. Imaging demonstrated that young adult CIA rats exhibited more widespread and severe skeletal lesions of the phalanges, metatarsals, and tarsal bones, whereas juvenile CIA rats had more localized and less proliferative and osteolytic damage that was confined predominantly to the phalanges and metatarsals. This report demonstrates the utility of imaging modalities to compare juvenile and young adult rats with CIA and provides evidence that disease characteristics and progression differ between the 2 age groups. Our observations indicate that the CIA model could help discern age-related pathologic processes in inflammatory joint diseases. PMID:24326225

  16. Elephant ear

    MedlinePlus

    The harmful substances in elephant ear plants are: Oxalic acid Asparagine, a protein found in this plant Note: ... days to a week if treated correctly. Rarely, oxalic acid may cause swelling severe enough to block the ...

  17. Swimmer's ear

    MedlinePlus

    ... or a respiratory infection such as a cold. Swimming in unclean water can lead to swimmer's ear. ... very well after it has gotten wet. Avoid swimming in polluted water. Use earplugs when swimming. Try ...

  18. Anti-Inflammatory and Antioxidant Effects of Repeated Exposure to Cruciferous Allyl Nitrile in Sensitizer-Induced Ear Edema in Mice

    PubMed Central

    Tanii, Hideji; Sugitani, Kayo; Saijoh, Kiyofumi

    2016-01-01

    Background Skin sensitizers induce allergic reactions through the induction of reactive oxygen species. Allyl nitrile from cruciferous vegetables has been reported to induce antioxidants and phase II detoxification enzymes in various tissues. We assessed the effects of repeated exposure to allyl nitrile on sensitizer-induced allergic reactions. Material/Methods Mice were dosed with allyl nitrile (0–200 μmol/kg), and then received a dermal application of 1 of 3 sensitizers on the left ear or 1 of 2 vehicles on the right ear. Quantitative assessment of edema was carried out by measuring the difference in weight between the portions taken from the right and left ears. We tested enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and thiobarbituric acid reactive substances (TBARS) in ears. Results Repeated exposure to allyl nitrile reduced edemas induced by glutaraldehyde and by 2, 4-dinitrochlorobenzene (DNCB), but not by formaldehyde. The repeated exposure decreased levels of TBARS, a marker of oxidative stress, induced by glutaraldehyde and by DNCB, but not by formaldehyde. Allyl nitrile elevated SOD levels for the 3 sensitizers, and CAT levels for formaldehyde and DNCB. Allyl nitrile also increased GPx levels for formaldehyde and DNCB, but not for glutaraldehyde. The reduced edemas were associated with changes in oxidative stress levels and antioxidant enzymes. Conclusions Repeated exposure to allyl nitrile reduced allergic reactions induced by glutaraldehyde and by DNCB, but not by formaldehyde. This reduction was associated with changes in ROS levels and antioxidant enzyme activities. PMID:26932717

  19. Simultaneous 3D imaging of sound-induced motions of the tympanic membrane and middle ear ossicles.

    PubMed

    Chang, Ernest W; Cheng, Jeffrey T; Röösli, Christof; Kobler, James B; Rosowski, John J; Yun, Seok Hyun

    2013-10-01

    Efficient transfer of sound by the middle ear ossicles is essential for hearing. Various pathologies can impede the transmission of sound and thereby cause conductive hearing loss. Differential diagnosis of ossicular disorders can be challenging since the ossicles are normally hidden behind the tympanic membrane (TM). Here we describe the use of a technique termed optical coherence tomography (OCT) vibrography to view the sound-induced motion of the TM and ossicles simultaneously. With this method, we were able to capture three-dimensional motion of the intact TM and ossicles of the chinchilla ear with nanometer-scale sensitivity at sound frequencies from 0.5 to 5 kHz. The vibration patterns of the TM were complex and highly frequency dependent with mean amplitudes of 70-120 nm at 100 dB sound pressure level. The TM motion was only marginally sensitive to stapes fixation and incus-stapes joint interruption; however, when additional information derived from the simultaneous measurement of ossicular motion was added, it was possible to clearly distinguish these different simulated pathologies. The technique may be applicable to clinical diagnosis in Otology and to basic research in audition and acoustics. PMID:23811181

  20. Chemically Modified Interleukin-6 Aptamer Inhibits Development of Collagen-Induced Arthritis in Cynomolgus Monkeys

    PubMed Central

    Murakami, Ikuo; Ishikawa, Yuichi; Suzuki, Tomoki; Sumida, Shun-ichiro; Ibaragi, Shigeru; Kasai, Hayato; Horai, Naoto; Drolet, Daniel W.; Gupta, Shashi; Janjic, Nebojsa

    2016-01-01

    Interleukin-6 (IL-6) is a potent mediator of inflammatory and immune responses, and a validated target for therapeutic intervention of inflammatory diseases. Previous studies have shown that SL1026, a slow off-rate modified aptamer (SOMAmer) antagonist of IL-6, neutralizes IL-6 signaling in vitro. In the present study, we show that SL1026 delays the onset and reduces the severity of rheumatoid symptoms in a collagen-induced arthritis model in cynomolgus monkeys. SL1026 (1 and 10 mg/kg), administered q.i.d., delayed the progression of arthritis and the concomitant increase in serum IL-6 levels compared to the untreated control group. Furthermore, SL1026 inhibited IL-6-induced STAT3 phosphorylation ex vivo in T lymphocytes from human blood and IL-6-induced C-reactive protein and serum amyloid A production in human primary hepatocytes. Importantly, SOMAmer treatment did not elicit an immune response, as evidenced by the absence of anti-SOMAmer antibodies in plasma of treated monkeys. These results demonstrate that SOMAmer antagonists of IL-6 may be attractive agents for the treatment of IL-6-mediated diseases, including rheumatoid arthritis. PMID:26579954

  1. Lactobacillus acidophilus maintained oxidative stress from reproductive organs in collagen-induced arthritic rats

    PubMed Central

    Amdekar, Sarika; Singh, Vinod

    2016-01-01

    CONTEXTS: Nonsteroidal anti-inflammatory drugs (NSAIDs) induced organ damage is a well-known fact. Previous studies suggest that Lactobacillus scavenge the free radicals from liver and kidney and also protect animals from arthritis. AIMS: Comparing protective properties of Lactobacillus acidophilus in reducing oxidative stress from reproductive organs developed during collagen-induced arthritis in animal model. METHODS: Arthritis was induced in Wistar rats. Oral administration of L. acidophilus, indomethacin, and distilled water were all started on the same day. Arthritis scores were calculated for each group. Oxidative stress parameters were estimated in testis and ovary homogenates. Histopathology of ovary and testis was also performed. RESULTS AND CONCLUSION: L. acidophilus decreased arthritis score (P < 0.001) as well as maintained normal histology of reproductive organs. L. acidophilus maintained oxidative stress parameters from ovaries and testis (P < 0.001). These results provide strong evidence that NSAIDs increase oxidative stress in reproductive organs while L. acidophilus not only scavenges free radicals from reproductive organs but also protects rats from arthritis symptoms. PMID:27110077

  2. Fenugreek seed (Trigonella foenum graecum) polyphenols inhibit ethanol-induced collagen and lipid accumulation in rat liver.

    PubMed

    Kaviarasan, S; Viswanathan, P; Anuradha, C V

    2007-11-01

    Chronic alcoholism is associated with fatty liver and fibrosis characterized by collagen accumulation. Seeds of fenugreek, an annual herb, are reported to possess hepatoprotective activity. The study aims to investigate the effects of fenugreek seed polyphenol extract (FPEt) on liver lipids and collagen in experimental hepatotoxic rats. Hepatotoxicity was induced in male albino Wistar rats by administrating ethanol (6 g/kg per day) for 30 days. Control rats were given isocaloric glucose solution. FPEt was co-administered with ethanol at a dose of 200 mg/kg per day for the next 30 days. Silymarin was used as a positive control. Ethanol treatment caused increase in plasma and liver lipids, together with alterations in collagen content and properties. Administration of FPEt to alcohol-fed rats significantly improved lipid profile and reduced collagen content, crosslinking, aldehyde content and peroxidation. The effects were comparable with that of silymarin. FPEt administration had a positive influence on both lipid profile and on the quantitative and qualitative properties of collagen in alcoholic liver disease. The protective effect is presumably due to the bioactive phytochemicals in fenugreek seeds. PMID:17453353

  3. Identification of the epitope for a monoclonal antibody that blocks platelet aggregation induced by type III collagen.

    PubMed Central

    Glattauer, V; Werkmeister, J A; Kirkpatrick, A; Ramshaw, J A

    1997-01-01

    A library of eight conformation-dependent monoclonal antibodies that react with distinct epitopes on native human type III collagen has been examined for the ability of these antibodies to inhibit platelet aggregation induced by this collagen. Six of these antibodies had no effects; one, 1E7-D7/Col3, delayed the onset and slowed the rate of platelet aggregation, while another, 2G8-B1/Col3, completely inhibited aggregation. In order to identify the epitope recognized by this inhibitory antibody, a series of peptides that could fold to form triple-helical fragments was examined. Each peptide included six Gly-Xaa-Yaa triplets from the human type III collagen sequence, where Xaa and Yaa represent the particular amino acids in the sequence, and a C-terminal (Gly-Pro-Hyp)4 sequence to enhance triple-helical stability. Using these peptides we have identified the epitope as a nine-amino-acid sequence, GLAGAOGLR (where O is the one-letter code for 4-hydroxyproline), starting at position 520 in the human type III collagen helical domain. This sequence is proximal to the site proposed for the interaction of type III collagen with alpha2beta1-integrin of platelets. PMID:9173900

  4. Porphyromonas gingivalis oral infection exacerbates the development and severity of collagen-induced arthritis

    PubMed Central

    2013-01-01

    Introduction Clinical studies suggest a direct influence of periodontal disease (PD) on serum inflammatory markers and disease assessment of patients with established rheumatoid arthritis (RA). However, the influence of PD on arthritis development remains unclear. This investigation was undertaken to determine the contribution of chronic PD to immune activation and development of joint inflammation using the collagen-induced arthritis (CIA) model. Methods DBA1/J mice orally infected with Porphyromonas gingivalis were administered with collagen II (CII) emulsified in complete Freund’s adjuvant (CFA) or incomplete Freund’s adjuvant (IFA) to induce arthritis. Arthritis development was assessed by visual scoring of paw swelling, caliper measurement of the paws, mRNA expression, paw micro-computed tomography (micro-CT) analysis, histology, and tartrate resistant acid phosphatase for osteoclast detection (TRAP)-positive immunohistochemistry. Serum and reactivated splenocytes were evaluated for cytokine expression. Results Mice induced for PD and/or arthritis developed periodontal disease, shown by decreased alveolar bone and alteration of mRNA expression in gingival tissues and submandibular lymph nodes compared to vehicle. P. gingivalis oral infection increased paw swelling and osteoclast numbers in mice immunized with CFA/CII. Arthritis incidence and severity were increased by P. gingivalis in mice that received IFA/CII immunizations. Increased synovitis, bone erosions, and osteoclast numbers in the paws were observed following IFA/CII immunizations in mice infected with P gingivalis. Furthermore, cytokine analysis showed a trend toward increased serum Th17/Th1 ratios when P. gingivalis infection was present in mice receiving either CFA/CII or IFA/CII immunizations. Significant cytokine increases induced by P. gingivalis oral infection were mostly associated to Th17-related cytokines of reactivated splenic cells, including IL-1β, IL-6, and IL-22 in the CFA

  5. Torilin ameliorates type II collagen-induced arthritis in mouse model of rheumatoid arthritis.

    PubMed

    Endale, Mehari; Lee, Whi Min; Kwak, Yi-Seong; Kim, Na-Mi; Kim, Bok-Kyu; Kim, Seung-Hyung; Cho, Jaeyoul; Kim, Suk; Park, Seung-Chun; Yun, Bong-Sik; Ko, Dukhwan; Rhee, Manhee

    2013-06-01

    Advancements in rheumatoid-arthritis-(RA) therapies have shown considerable progresses in the comprehension of disease. However, the development of new potential agents with relative safety and efficacy continues and natural compounds have been considered as alternatives to identify new entities. Since previous in-vivo data and our in-vitro findings showed that torilin has a strong anti-inflammatory property, we further investigated its effect against collagen-induced-arthritis-(CIA) in mice. CIA-induced DBA/1J mice were treated with torilin or methotrexate (MTX) for 5-weeks. Arthritis severity was evaluated by arthritic score and joint histopathology. Draining lymph node (dLN), joint and peripheral-blood mononuclear-cell (PBMC) counts, and activation/localization of T-/B-lymphocytes, dendritic cells (DCs) and neutrophils were examined by FACS analysis. Serum anti-type-II-collagen-(CII) antibody levels and cultured-splenocyte and serum cytokines were also evaluated. Torilin markedly reduced CIA-induced arthritic score, histopathology and leukocyte counts. Besides, torilin suppressed CIA-activated T-cells including CD3+, CD3+/CD69+, CD8+, CD4+ and CD4+/CD25+ in dLNs or joints. It also modified CD19+ or CD20+/CD23+ (B-cells), MHCII+/CD11c+ (DCs) and Gr-1+/CD11b+ (neutrophil) subpopulations. It further depressed total anti-CII-IgG, anti-CII-IgG1 and anti-CII-IgG2a antibody productions. Moreover, while IFN-γ and IL-10 were not affected, torilin suppressed CIA-induced serum TNF-α, IL-1β and IL-6 levels. Interestingly, torilin also blocked IFN-γ, IL-17 and IL-6 cytokines while it did not affect IL-10 but enhanced IL-4 in splenocytes. These results show that torilin attenuated arthritis severity, modified leukocyte activations in dLNs or joints, and restored serum and splenocyte cytokine imbalances. Torilin may have immunomodulatory and anti-inflammatory properties with the capacity to ameliorate the inflammatory response in CIA-mice. PMID:23623942

  6. Effects of low molecular weight chondroitin sulfate on type II collagen-induced arthritis in DBA/1J mice.

    PubMed

    Cho, So Yean; Sim, Joon-Soo; Jeong, Choon Sik; Chang, Seung Yeup; Choi, Don Woong; Toida, Toshihiko; Kim, Yeong Shik

    2004-01-01

    In order to evaluate the improvement in the treatment of chronic arthritis, we investigated chondroitin sulfate depolymerization product (low molecular weight chondroitin sulfate, LMWCS) and intact chondroitin sulfate (CS) in vitro and in vivo. LMWCS was prepared by a chemical depolymerization process induced by hydrogen peroxide in the presence of copper salts. LMWCS (300 mg/kg) and CS (1200 mg/kg) were orally administered to DBA/1J mice once daily for 14 d prior to initial immunization with type II collagen. Their elastase activities and the production of cytokines in sera were examined on type II collagen-induced arthritis in DBA/1J mice. We also compared the paracellular transport of LMWCS and CS across Caco-2 cell monolayers and examined the inhibitory effects on elastase activities. LMWCS inhibited elastase activity slightly, but CS did not show inhibition. Hind paw edema was significantly decreased by LMWCS treatment. Levels of anti-type II collagen antibody and tumor necrosis factor-alpha (TNF-alpha) in sera were also reduced by LMWCS treatment but not in case of CS, although no significant difference was observed between LMWCS and CS on interleukin-6 (IL-6) induction. The LMWCS preparation showed preventive effects on the type II collagen-induced arthritis in DBA/1J mice and better permeability through Caco-2 cells. PMID:14709897

  7. Regenerative effects of moxibustion on skeletal muscle in collagen-induced arthritic mice.

    PubMed

    Kim, Min-Jung; Namgung, Uk; Hong, Kwon-Eui

    2012-06-01

    In this study, we demonstrate that the direct application of moxibustion significantly enhances muscle regeneration in mice with collagen-induced arthritis (CIA). Twelve Dilute Brown Non-Agouti (DBA)/1 J male mice were randomly divided into the following groups: intact control (n=4), CIA (n=4), and CIA with moxibustion treatment (CIA+moxi, n=4). Mice in the CIA and CIA+moxi groups were immunized twice via intradermal injections of bovine type II collagen (C II) at 3-week intervals. After the second injection, moxibustion was applied to the mouse equivalent of the BL24 and ST36 acupoints with a moxa cone five times/day, every other day (except Sundays), for 3 weeks (a total of 9 treatments were administered). Phospho-Erk1/2, myostatin, TFG-B1, and IGF-1 were analyzed using ELISA. Protein levels in skeletal muscle tissues of the hind limb were analyzed by Western blotting and immunofluorescent staining. Treatment with direct moxibustion led to a marked improvement in CIA and atrophy of individual muscle fibers. Collagen protein signaling in the muscle of the CIA group was stronger than the control and CIA+moxi groups. Myostatin protein expression, as determined by Western blotting and immunofluorescent staining, were stronger in the CIA group compared with the control and CIA+moxi groups. Immunofluorescent staining confirmed that the CIA group had the strongest TGF-B1 protein signals among the three groups. However, in serum analysis the intact control group showed the strongest TGF-B1 protein signaling. RT-PCR analysis of the muscle tissues of the CIA+moxi group showed significant IGF-1 mRNA expression, and the most intense phospho-Erk1/2 protein signaling was detected in the muscle tissues of the CIA group via Western blotting and immunofluorescent staining. These results confirm that the direct administration of moxibustion at Shenshu (BL 23) and Zusanli (ST 36) influences muscle regeneration in the CIA mouse model. Our results suggest that the establishment of

  8. Novel therapeutic compound tuftsin-phosphorylcholine attenuates collagen-induced arthritis.

    PubMed

    Bashi, T; Shovman, O; Fridkin, M; Volkov, A; Barshack, I; Blank, M; Shoenfeld, Y

    2016-04-01

    Treatment with helminthes and helminthes ova improved the clinical symptoms of several autoimmune diseases in patients and in animal models. Phosphorylcholine (PC) proved to be the immunomodulatory molecule. We aimed to decipher the tolerogenic potential of tuftsin-PC (TPC), a novel helminth-based compound in collagen-induced arthritis (CIA) a mouse model of rheumatoid arthritis (RA). CIA DBA/1 mice were treated with TPC subcutaneously (5 µg/0.1 ml) or orally (250 µg/0.1 ml), starting prior to disease induction. The control groups were treated with PBS. Collagen antibodies were tested by enzyme-linked immunosorbent assay (ELISA), cytokine protein levels by ELISA kits and regulatory T (Treg ) and regulatory B (Breg ) cell phenotypes by fluorescence-activated cell sorter (FACS). TPC-treated mice had a significantly lower arthritis score of 1.5 in comparison with control mice 11.8 (P < 0.0001) in both subcutaneous and orally treated groups at day 31. Moreover, histology analysis demonstrated highly inflamed joints in control mice, whereas TPC-treated mice maintained normal joint structure. Furthermore, TPC decreased the titres of circulating collagen II antibodies in mice sera (P < 0.0001), enhanced expression of IL-10 (P < 0.0001) and inhibited production of tumour necrosis factor (TNF)-α, interleukin (IL)-17 and IL-1β (P < 0.0001). TPC significantly expanded the CD4(+) CD25(+) forkhead box protein 3 (FoxP3(+) ) Treg cells and CD19(+) IL-10(+) CD5(high) CD1d(high) T cell immunoglobulin mucin-1 (TIM-1(+) ) Breg cell phenotypes (P < 0.0001) in treated mice. Our data indicate that treatment with TPC attenuates CIA in mice demonstrated by low arthritic score and normal joints histology. TPC treatment reduced proinflammatory cytokines and increased anti-inflammatory cytokine expression, as well as expansion of Treg and Breg cells. Our results may lead to a new approach for a natural therapy for early rheumatoid arthritis onset. PMID:26618631

  9. Parathyroid hormone attenuates radiation-induced increases in collagen crosslink ratio at periosteal surfaces of mouse tibia.

    PubMed

    Oest, Megan E; Gong, Bo; Esmonde-White, Karen; Mann, Kenneth A; Zimmerman, Nicholas D; Damron, Timothy A; Morris, Michael D

    2016-05-01

    As part of our ongoing efforts to understand underlying mechanisms contributing to radiation-associated bone fragility and to identify possible treatments, we evaluated the longitudinal effects of parathyroid hormone (PTH) treatment on bone quality in a murine model of limited field irradiation. We hypothesized PTH would mitigate radiation-induced changes in the chemical composition and structure of bone, as measured by microscope-based Raman spectroscopy. We further hypothesized that collagen crosslinking would be especially responsive to PTH treatment. Raman spectroscopy was performed on retrieved tibiae (6-7/group/time point) to quantify metrics associated with bone quality, including: mineral-to-matrix ratio, carbonate-to-phosphate ratio, mineral crystallinity, collagen crosslink (trivalent:divalent) ratio, and the mineral and matrix depolarization ratios. Irradiation disrupted the molecular structure and orientation of bone collagen, as evidenced by a higher collagen crosslink ratio and lower matrix depolarization ratio (vs. non-irradiated control bones), persisting until 12weeks post-irradiation. Radiation transiently affected the mineral phase, as evidenced by increased mineral crystallinity and mineral-to-matrix ratio at 4weeks compared to controls. Radiation decreased bone mineral depolarization ratios through 12weeks, indicating increased mineral alignment. PTH treatment partially attenuated radiation-induced increases in collagen crosslink ratio, but did not restore collagen or mineral alignment. These post-radiation matrix changes are consistent with our previous studies of radiation damage to bone, and suggest that the initial radiation damage to bone matrix has extensive effects on the quality of tissue deposited thereafter. In addition to maintaining bone quality, preventing initial radiation damage to the bone matrix (i.e. crosslink ratio, matrix orientation) may be critical to preventing late-onset fragility fractures. PMID:26960578

  10. Nanoparticulate Delivery of Agents for Induced Elastogenesis in 3-Dimensional Collagenous Matrices

    PubMed Central

    Venkataraman, Lavanya; Sivaraman, Balakrishnan; Vaidya, Pratik; Ramamurthi, Anand

    2014-01-01

    The degradation of elastic matrix in the infrarenal aortic wall is a critical parameter underlying the formation and progression of abdominal aortic aneurysms (AAAs). It is mediated by the chronic overexpression of matrix metalloproteases (MMPs) -2 and -9, leading to a progressive loss of elasticity and weakening of the aortic wall. Delivery of therapeutic agents to inhibit MMPs, while concurrently coaxing cell-based regenerative repair of the elastic matrix represents a potential strategy for slowing or arresting AAA growth. Our prior studies have demonstrated elastogenic induction of healthy and aneurysmal aortic smooth muscle cells (SMCs) and inhibition of MMPs, following exogenous delivery of elastogenic factors such as TGF-β1, as well as MMP-inhibitors such as doxycycline (DOX) in two-dimensional (2-D) culture. Based on these findings, and others that demonstrated elastogenic benefits of nanoparticulate delivery of these agents in 2-D culture, we have developed poly(lactide-co-glycolide) nanoparticles for localized, controlled and sustained delivery of DOX and TGF-β1 to human aortic SMCs (HASMCs) within a three-dimensional (3-D) gels of type-I collagen gel, which closely evoke the arterial tissue microenvironment. DOX and TGF-β1 released from these NPs influenced elastogenic outcomes positively within the collagen constructs over 21 days of culture, which were comparable to that induced by exogenous supplementation of DOX and TGF-β1 within the culture medium. However, this was accomplished at doses ∼20-fold lower than the exogenous dosages of the agents, illustrating that their localized, controlled, and sustained delivery from NPs embedded within a 3-D scaffold is an efficient strategy for directed elastogenesis. PMID:24737693

  11. Phenotypic characterization of type II collagen-induced arthritis in Wistar rats

    PubMed Central

    SONG, HOU-PAN; LI, XIN; YU, RONG; ZENG, GUANG; YUAN, ZHEN-YI; WANG, WEI; HUANG, HUI-YONG; CAI, XIONG

    2015-01-01

    The aim of the present study was to determine a more specific, efficient and simple method for the induction of collagen-induced arthritis (CIA) in rats. Different strains of rats were injected at the base of the tail with bovine type II collagen (CII) emulsified in incomplete Freund's adjuvant (IFA). The onset and severity of arthritis were evaluated by clinical assessment. The established CIA model was analyzed using a comprehensive examination of clinical, hematological, histological and radiological parameters. The results demonstrated that Wistar rats were the most susceptible strain to CIA followed by Wistar Furth rats, with Sprague Dawley rats being the least susceptible. Following primary and booster immunization, female Wistar rats developed severe arthritis, with an incidence of >83% and low variability in clinical signs. The development of arthritis was accompanied by a significantly elevated erythrocyte sedimentation rate compared with that in the control rats. The radiographic examination revealed bone matrix resorption, considerable soft tissue swelling, periosteal new bone formation and bone erosion in the arthritic joints of the CIA rats. Histopathologically, the synovial joints of CIA rats were characterized by synovial hyperplasia, pannus formation, marked cellular infiltration, bone and cartilage erosion and narrowing of the joint space. The administration of an intradermal injection of only 200 µg bovine CII emulsified in IFA at the base of the tail therefore leads to the successful development of a CIA rat model. This well-characterized CIA rat model could be specifically used to study the pathophysiology of human rheumatoid arthritis as well as to test and develop anti-arthritic agents for humans. PMID:26622511

  12. Adipose-Derived Mesenchymal Stem Cells Prevent Systemic Bone Loss in Collagen-Induced Arthritis.

    PubMed

    Garimella, Manasa G; Kour, Supinder; Piprode, Vikrant; Mittal, Monika; Kumar, Anil; Rani, Lekha; Pote, Satish T; Mishra, Gyan C; Chattopadhyay, Naibedya; Wani, Mohan R

    2015-12-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammatory synovitis leading to joint destruction and systemic bone loss. The inflammation-induced bone loss is mediated by increased osteoclast formation and function. Current antirheumatic therapies primarily target suppression of inflammatory cascade with limited or no success in controlling progression of bone destruction. Mesenchymal stem cells (MSCs) by virtue of their tissue repair and immunomodulatory properties have shown promising results in various autoimmune and degenerative diseases. However, the role of MSCs in prevention of bone destruction in RA is not yet understood. In this study, we investigated the effect of adipose-derived MSCs (ASCs) on in vitro formation of bone-resorbing osteoclasts and pathological bone loss in the mouse collagen-induced arthritis (CIA) model of RA. We observed that ASCs significantly inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in both a contact-dependent and -independent manner. Additionally, ASCs inhibited RANKL-induced osteoclastogenesis in the presence of proinflammatory cytokines such as TNF-α, IL-17, and IL-1β. Furthermore, treatment with ASCs at the onset of CIA significantly reduced clinical symptoms and joint pathology. Interestingly, ASCs protected periarticular and systemic bone loss in CIA mice by maintaining trabecular bone structure. We further observed that treatment with ASCs reduced osteoclast precursors in bone marrow, resulting in decreased osteoclastogenesis. Moreover, ASCs suppressed autoimmune T cell responses and increased the percentages of peripheral regulatory T and B cells. Thus, we provide strong evidence that ASCs ameliorate inflammation-induced systemic bone loss in CIA mice by reducing osteoclast precursors and promoting immune tolerance. PMID:26538398

  13. Full-Length Fibronectin Drives Fibroblast Accumulation at the Surface of Collagen Microtissues during Cell-Induced Tissue Morphogenesis.

    PubMed

    Foolen, Jasper; Shiu, Jau-Ye; Mitsi, Maria; Zhang, Yang; Chen, Christopher S; Vogel, Viola

    2016-01-01

    Generating and maintaining gradients of cell density and extracellular matrix (ECM) components is a prerequisite for the development of functionality of healthy tissue. Therefore, gaining insights into the drivers of spatial organization of cells and the role of ECM during tissue morphogenesis is vital. In a 3D model system of tissue morphogenesis, a fibronectin-FRET sensor recently revealed the existence of two separate fibronectin populations with different conformations in microtissues, i.e. 'compact and adsorbed to collagen' versus 'extended and fibrillar' fibronectin that does not colocalize with the collagen scaffold. Here we asked how the presence of fibronectin might drive this cell-induced tissue morphogenesis, more specifically the formation of gradients in cell density and ECM composition. Microtissues were engineered in a high-throughput model system containing rectangular microarrays of 12 posts, which constrained fibroblast-populated collagen gels, remodeled by the contractile cells into trampoline-shaped microtissues. Fibronectin's contribution during the tissue maturation process was assessed using fibronectin-knockout mouse embryonic fibroblasts (Fn-/- MEFs) and floxed equivalents (Fnf/f MEFs), in fibronectin-depleted growth medium with and without exogenously added plasma fibronectin (full-length, or various fragments). In the absence of full-length fibronectin, Fn-/- MEFs remained homogenously distributed throughout the cell-contracted collagen gels. In contrast, in the presence of full-length fibronectin, both cell types produced shell-like tissues with a predominantly cell-free compacted collagen core and a peripheral surface layer rich in cells. Single cell assays then revealed that Fn-/- MEFs applied lower total strain energy on nanopillar arrays coated with either fibronectin or vitronectin when compared to Fnf/f MEFs, but that the presence of exogenously added plasma fibronectin rescued their contractility. While collagen decoration of

  14. Sympathetic Neurotransmitters Modulate Osteoclastogenesis and Osteoclast Activity in the Context of Collagen-Induced Arthritis

    PubMed Central

    Muschter, Dominique; Schäfer, Nicole; Stangl, Hubert; Straub, Rainer H.; Grässel, Susanne

    2015-01-01

    Excessive synovial osteoclastogenesis is a hallmark of rheumatoid arthritis (RA). Concomitantly, local synovial changes comprise neuronal components of the peripheral sympathetic nervous system. Here, we wanted to analyze if collagen-induced arthritis (CIA) alters bone marrow-derived macrophage (BMM) osteoclastogenesis and osteoclast activity, and how sympathetic neurotransmitters participate in this process. Therefore, BMMs from Dark Agouti rats at different CIA stages were differentiated into osteoclasts in vitro and osteoclast number, cathepsin K activity, matrix resorption and apoptosis were analyzed in the presence of acetylcholine (ACh), noradrenaline (NA) vasoactive intestinal peptide (VIP) and assay-dependent, adenylyl cyclase activator NKH477. We observed modulation of neurotransmitter receptor mRNA expression in CIA osteoclasts without affecting protein level. CIA stage-dependently altered marker gene expression associated with osteoclast differentiation and activity without affecting osteoclast number or activity. Neurotransmitter stimulation modulated osteoclast differentiation, apoptosis and activity. VIP, NA and adenylyl cyclase activator NKH477 inhibited cathepsin K activity and osteoclastogenesis (NKH477, 10-6M NA) whereas ACh mostly acted pro-osteoclastogenic. We conclude that CIA alone does not affect metabolism of in vitro generated osteoclasts whereas stimulation with NA, VIP plus specific activation of adenylyl cyclase induced anti-resorptive effects probably mediated via cAMP signaling. Contrary, we suggest pro-osteoclastogenic and pro-resorptive properties of ACh mediated via muscarinic receptors. PMID:26431344

  15. Anti-Arthritic Effect of Chebulanin on Collagen-Induced Arthritis in Mice

    PubMed Central

    Zhao, Yinglan; Liu, Fang; Liu, Yao; Zhou, Dan; Dai, Qing; Liu, Songqing

    2015-01-01

    Rheumatoid arthritis is a chronic degenerative autoimmune disease characterized by persistent inflammation of synovial membranes, which leads to cartilage destruction and bone erosion. To date, there are no effective therapies to slow the progress of this degenerative condition. Here, we evaluate the anti-arthritic effect of chebulanin, an abundant anti-inflammatory agent isolated from Terminalia chebula, in collagen induced arthritis in DBA/1 mice by intragastric administration. Arthritic severity was scored by performing histopathological evaluation of the joints and measuring the expression of inflammatory cytokines and relative enzymes by immunohistochemical staining. In parallel, bone destruction and erosion were confirmed by micro-CT. Our data revealed that chebulanin significantly improved the severity of arthritis. Specifically, the histopathological characteristics of the tissues were improved and expression of TNF-α, IL-6, MMP-3 and COX-2 in the paws and joints of the treated mice decreased in a dose-dependent manner compared with control mice. Furthermore, micro-CT analysis revealed that chebulanin induced a dose-dependent reduction in cartilage destruction and bone erosion. Taken together, our findings suggest that chebulanin suppresses the expression of inflammatory mediators and prevents cartilage destruction and bone erosion in mice. Therefore, chebulanin is a strong therapeutic alternative for the treatment of RA. PMID:26402786

  16. Compression loading-induced stress responses in intervertebral disc cells encapsulated in 3D collagen constructs

    PubMed Central

    Chooi, Wai Hon; Chan, Barbara Pui

    2016-01-01

    Cells protect themselves from stresses through a cellular stress response. In the interverebral disc, such response was also demonstrated to be induced by various environmental stresses. However, whether compression loading will cause cellular stress response in the nucleus pulposus cells (NPCs) is not well studied. By using an in vitro collagen microencapsulation model, we investigated the effect of compression loading on the stress response of NPCs. Cell viability tests, and gene and protein expression experiments were conducted, with primers for the heat shock response (HSR: HSP70, HSF1, HSP27 and HSP90), and unfolded protein response (UPR: GRP78, GRP94, ATF4 and CHOP) genes and an antibody to HSP72. Different gene expression patterns occurred due to loading type throughout experiments. Increasing the loading strain for a short duration did not increase the stress response genes significantly, but over longer durations, HSP70 and HSP27 were upregulated. Longer loading durations also resulted in a continuous upregulation of HSR genes and downregulation of UPR genes, even after load removal. The rate of apoptosis did not increase significantly after loading, suggesting that stress response genes might play a role in cell survival following mechanical stress. These results demonstrate how mechanical stress might induce and control the expression of HSR and UPR genes in NPCs. PMID:27197886

  17. Mucosal Administration of Collagen V Ameliorates the Atherosclerotic Plaque Burden by Inducing Interleukin 35-dependent Tolerance.

    PubMed

    Park, Arick C; Huang, Guorui; Jankowska-Gan, Ewa; Massoudi, Dawiyat; Kernien, John F; Vignali, Dario A; Sullivan, Jeremy A; Wilkes, David S; Burlingham, William J; Greenspan, Daniel S

    2016-02-12

    We have shown previously that collagen V (col(V)) autoimmunity is a consistent feature of atherosclerosis in human coronary artery disease and in the Apoe(-/-) mouse model. We have also shown sensitization of Apoe(-/-) mice with col(V) to markedly increase the atherosclerotic burden, providing evidence of a causative role for col(V) autoimmunity in atherosclerotic pathogenesis. Here we sought to determine whether induction of immune tolerance to col(V) might ameliorate atherosclerosis, providing further evidence for a causal role for col(V) autoimmunity in atherogenesis and providing insights into the potential for immunomodulatory therapeutic interventions. Mucosal inoculation successfully induced immune tolerance to col(V) with an accompanying reduction in plaque burden in Ldlr(-/-) mice on a high-cholesterol diet. The results therefore demonstrate that inoculation with col(V) can successfully ameliorate the atherosclerotic burden, suggesting novel approaches for therapeutic interventions. Surprisingly, tolerance and reduced atherosclerotic burden were both dependent on the recently described IL-35 and not on IL-10, the immunosuppressive cytokine usually studied in the context of induced tolerance and amelioration of atherosclerotic symptoms. In addition to the above, using recombinant protein fragments, we were able to localize two epitopes of the α1(V) chain involved in col(V) autoimmunity in atherosclerotic Ldlr(-/-) mice, suggesting future courses of experimentation for the characterization of such epitopes. PMID:26721885

  18. Compression loading-induced stress responses in intervertebral disc cells encapsulated in 3D collagen constructs.

    PubMed

    Chooi, Wai Hon; Chan, Barbara Pui

    2016-01-01

    Cells protect themselves from stresses through a cellular stress response. In the interverebral disc, such response was also demonstrated to be induced by various environmental stresses. However, whether compression loading will cause cellular stress response in the nucleus pulposus cells (NPCs) is not well studied. By using an in vitro collagen microencapsulation model, we investigated the effect of compression loading on the stress response of NPCs. Cell viability tests, and gene and protein expression experiments were conducted, with primers for the heat shock response (HSR: HSP70, HSF1, HSP27 and HSP90), and unfolded protein response (UPR: GRP78, GRP94, ATF4 and CHOP) genes and an antibody to HSP72. Different gene expression patterns occurred due to loading type throughout experiments. Increasing the loading strain for a short duration did not increase the stress response genes significantly, but over longer durations, HSP70 and HSP27 were upregulated. Longer loading durations also resulted in a continuous upregulation of HSR genes and downregulation of UPR genes, even after load removal. The rate of apoptosis did not increase significantly after loading, suggesting that stress response genes might play a role in cell survival following mechanical stress. These results demonstrate how mechanical stress might induce and control the expression of HSR and UPR genes in NPCs. PMID:27197886

  19. Resistance to collagen-induced arthritis in SHPS-1 mutant mice

    SciTech Connect

    Okuzawa, Chie; Kaneko, Yoriaki; Murata, Yoji; Miyake, Astuko; Saito, Yasuyuki; Okajo, Jun; Tomizawa, Takeshi; Kaneko, Yuka; Okazawa, Hideki; Ohnishi, Hiroshi; Matozaki, Takashi Nojima, Yoshihisa

    2008-07-04

    SHPS-1 is a transmembrane protein that binds the protein tyrosine phosphatases SHP-1 and SHP-2 through its cytoplasmic region and is abundantly expressed on dendritic cells and macrophages. Here we show that mice expressing a mutant form of SHPS-1 fail to develop type-II collagen (CII)-induced arthritis (CIA), a model for rheumatoid arthritis in humans. Histological examinations of the arthritic paws from immunized wild-type mice revealed that cartilage was destroyed in association with marked mononuclear cell infiltration, while only mild cell infiltration was observed in immunized SHPS-1 mutant mice. Consistently, the serum levels of both IgG and IgG2a specific to CII and of IL-1{beta} in immunized SHPS-1 mutant mice were markedly reduced compared with those apparent for wild-type mice. The CII-induced proliferation of, and production of cytokines by, T cells from immunized SHPS-1 mutant mice were reduced compared to wild-type cells. These results suggest that SHPS-1 is essential for development of CIA.

  20. The involvement of platelets and the coronary vasculature in collagen-induced sudden death in rabbits.

    PubMed

    Mallarkey, G; Smith, G M

    1985-02-18

    The mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TXB2) and 6-keto prostaglandin F1a (6-keto PGF1a). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBS), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TXB2 levels. 6-keto PGF1a could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TXB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KCl, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBS physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death. PMID:3992523

  1. Tolerogenic splenic IDO (+) dendritic cells from the mice treated with induced-Treg cells suppress collagen-induced arthritis.

    PubMed

    Yang, Jie; Yang, Yiming; Fan, Huahua; Zou, Hejian

    2014-01-01

    TGF-β-induced regulatory T cells (iTregs) retain Foxp3 expression and immune-suppressive activity in collagen-induced arthritis (CIA). However, the mechanisms whereby transferred iTregs suppress immune responses, particularly the interplay between iTregs and dendritic cells (DCs) in vivo, remain incompletely understood. In this study, we found that after treatment with iTregs, splenic CD11c(+)DCs, termed "DCiTreg," expressed tolerogenic phenotypes, secreted high levels of IL-10, TGF-β, and IDO, and showed potent immunosuppressive activity in vitro. After reinfusion with DCiTreg, marked antiarthritic activity improved clinical scores and histological end-points were observed. The serological levels of inflammatory cytokines and anti-CII antibodies were low and TGF-β production was high in the DCiTreg-treated group. DCiTreg also induced new iTregs in vivo. Moreover, the inhibitory activity of DCiTreg on CIA was lost following pretreatment with the inhibitor of indoleamine 2,3-dioxygenase (IDO). Collectively, these findings suggest that transferred iTregs could induce tolerogenic characteristics in splenic DCs and these cells could effectively dampen CIA in an IDO-dependent manner. Thus, the potential therapeutic effects of iTregs in CIA are likely maintained through the generation of tolerogenic DCs in vivo. PMID:25405209

  2. Multiphoton microscopy of engineered dermal substitutes: assessment of 3-D collagen matrix remodeling induced by fibroblast contraction

    NASA Astrophysics Data System (ADS)

    Pena, Ana-Maria; Fagot, Dominique; Olive, Christian; Michelet, Jean-François; Galey, Jean-Baptiste; Leroy, Frédéric; Beaurepaire, Emmanuel; Martin, Jean-Louis; Colonna, Anne; Schanne-Klein, Marie-Claire

    2010-09-01

    Dermal fibroblasts are responsible for the generation of mechanical forces within their surrounding extracellular matrix and can be potentially targeted by anti-aging ingredients. Investigation of the modulation of fibroblast contraction by these ingredients requires the implementation of three-dimensional in situ imaging methodologies. We use multiphoton microscopy to visualize unstained engineered dermal tissue by combining second-harmonic generation that reveals specifically fibrillar collagen and two-photon excited fluorescence from endogenous cellular chromophores. We study the fibroblast-induced reorganization of the collagen matrix and quantitatively evaluate the effect of Y-27632, a RhoA-kinase inhibitor, on dermal substitute contraction. We observe that collagen fibrils rearrange around fibroblasts with increasing density in control samples, whereas collagen fibrils show no remodeling in the samples containing the RhoA-kinase inhibitor. Moreover, we show that the inhibitory effects are reversible. Our study demonstrates the relevance of multiphoton microscopy to visualize three-dimensional remodeling of the extracellular matrix induced by fibroblast contraction or other processes.

  3. Membrane-associated 41-kDa GTP-binding protein in collagen-induced platelet activation

    SciTech Connect

    Walker, G.; Bourguignon, L.Y. )

    1990-08-01

    Initially we established that the binding of collagen to human blood platelets stimulates both the rapid loss of PIP2 and the generation of inositol-4,5-bisphosphate (IP2) and inositol-1,4,5-triphosphate (IP3). These results indicate that the binding of collagen stimulates inositol phospholipid-specific phospholipase C during platelet activation. The fact that GTP or GTP-gamma-S augments, and pertussis toxin inhibits, collagen-induced IP3 formation suggests that a GTP-binding protein or (or proteins) may be directly involved in the regulation of phospholipase C-mediated phosphoinositide turnover in human platelets. We have used several complementary techniques to isolate and characterize a platelet 41-kDa polypeptide (or polypeptides) that has a number of structural and functional similarities to the regulatory alpha i subunit of the GTP-binding proteins isolated from bovine brain. This 41-kDa polypeptide (or polypeptides) is found to be closely associated with at least four membrane glycoproteins (e.g., gp180, gp110, gp95, and gp75) in a 330-kDa complex that can be dissociated by treatment with high salt plus urea. Most important, we have demonstrated that antilymphoma 41-kDa (alpha i subunit of GTP-binding proteins) antibody cross-reacts with the platelet 41-kDa protein (or proteins) and the alpha i subunit of bovine brain Gi alpha proteins, and blocks GTP/collagen-induced IP3 formation. These data provide strong evidence that the 41-kDa platelet GTP-binding protein (or proteins) is directly involved in collagen-induced signal transduction during platelet activation.

  4. Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation: From Clinical to Bench Studies.

    PubMed

    Hung, Chi-Sheng; Chou, Chia-Hung; Liao, Che-Wei; Lin, Yen-Tin; Wu, Xue-Ming; Chang, Yi-Yao; Chen, Ying-Hsien; Wu, Vin-Cent; Su, Ming-Jai; Ho, Yi-Lwun; Chen, Ming-Fong; Wu, Kwan-Dun; Lin, Yen-Hung

    2016-06-01

    Aldosterone induces myocardial fibrosis. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a key factor of myocardial fibrosis. This study tested the hypothesis that aldosterone induces TIMP-1 expression and contributes to the fibrotic process. We prospectively enrolled 54 patients with primary aldosteronism, and measured plasma TIMP-1 and echocardiographic parameters. In the cell study, we investigated the possible molecular mechanism by which aldosterone induces TIMP-1 secretion and the effects on collagen accumulation. In the animal study, we measured serum TIMP-1 levels, cardiac TIMP-1 levels, and cardiac structure in an aldosterone infusion mouse model using implantation of aldosterone pellets. In patients with primary aldosteronism, plasma TIMP-1 was correlated with 24-hour urinary aldosterone, left ventricular mass, and impairment of left ventricular diastolic function. In human cardiac fibroblasts, TIMP-1 protein and mRNA expressions were significantly increased by aldosterone through the glucocorticoid receptor/PI3K/Akt/nuclear factor-κB pathway. TIMP-1 small-interfering RNA significantly reduced aldosterone-induced collagen accumulation, and aldosterone did not alter the levels of collagen1a1 or matrix metalloproteinase-1 mRNA. The aldosterone-induced TIMP-1 expression was inversely related to matrix metalloproteinase-1 activity. Furthermore, in the animal model, the serum and cardiac levels of TIMP-1 were significantly elevated in the mice that received aldosterone infusion. This elevation was blocked by RU-486 but not by eplerenone, suggesting that the effect was through glucocorticoid receptors. In a long-term aldosterone infusion model, serum TIMP-1 was associated with serum aldosterone level, cardiac structure, and fibrosis. In conclusion, aldosterone induced TIMP-1 expression in vivo and in vitro. This increased TIMP-1 expression resulted in enhanced collagen accumulation via the suppression of matrix metalloproteinase-1 activity. PMID:27113051

  5. Cosmetic ear surgery

    MedlinePlus

    Otoplasty; Ear pinning; Ear surgery - cosmetic; Ear reshaping; Pinnaplasty ... 31. Thorne CH. Otoplasty. In: Neligan PC, ed. Plastic Surgery . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2013:chap ...

  6. Cu,Zn-SOD deficiency induces the accumulation of hepatic collagen.

    PubMed

    Sakiyama, Haruhiko; Fujiwara, Noriko; Yoneoka, Yuka; Yoshihara, Daisaku; Eguchi, Hironobu; Suzuki, Keiichiro

    2016-06-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic diseases, and results in the development of fibrosis. Oxidative stress is thought to be one of the underlying causes of NAFLD. Copper/zinc superoxide dismutase (SOD1) is a primary antioxidative enzyme that scavenges superoxide anion radicals. Although SOD1 knockout (KO) mice have been reported to develop fatty livers, it is not known whether this lack of SOD1 leads to the development of fibrosis. Since the accumulation of collagen typically precedes liver fibrosis, we assessed the balance between the synthesis and degradation of collagen in liver tissue from SOD1 KO mice. We found a higher accumulation of collagen in the livers of SOD1 KO mice compared to wild type mice. The level of expression of HSP47, a chaperone of collagen, and a tissue inhibitor (TIMP1) of matrix metalloproteinases (a collagen degradating enzyme) was also increased in SOD1 KO mice livers. These results indicate that collagen synthesis is increased but that its degradation is inhibited in SOD1 KO mice livers. Moreover, SOD1 KO mice liver sections were extensively modified by advanced glycation end products (AGEs), which suggest that collagen in SOD1 KO mice liver might be also modified with AGEs and then would be more resistant to the action of collagen degrading enzymes. These findings clearly show that oxidative stress plays an important role in the progression of liver fibrosis. PMID:26981929

  7. Collagen-gel-induced resistance of overlying keratinocyte cultures to photosensitization

    NASA Astrophysics Data System (ADS)

    Katsantonis, John C.; Georgiou, Savas K.; Providaki, Mary G.; Vlahonikolis, John G.; Tosca, Andronicki D.

    1997-12-01

    In the present study it was found that human keratinocytes grown on collagen substrate, exhibited increased resistance to the hematoprophyrin-mediated photodynamic treatment, in comparison to keratinocytes grown on Petri dishes without collagen. Interestingly, no protection was afforded by the collagen gel to the cells in the corresponding control ('hematoprophyrin only' and 'light only') experiments. This observation was found to be independent of light dose and drug concentration, and the relative degree of resistance was the same for both normal and malignant cells. The degree of keratinocyte resistance was found to be closely related to the duration of cell attachment on the collagen substrate. These results are indicative of an active interference of collagen gel with the cellular evolution of the photodynamic phenomenon and they are also suggestive of variation in the photodynamic treatment efficacy according to the cellular environment.

  8. Nanofibrous clinical-grade collagen scaffolds seeded with human cardiomyocytes induces cardiac remodeling in dilated cardiomyopathy.

    PubMed

    Joanne, Pierre; Kitsara, Maria; Boitard, Solène-Emmanuelle; Naemetalla, Hany; Vanneaux, Valérie; Pernot, Mathieu; Larghero, Jérôme; Forest, Patricia; Chen, Yong; Menasché, Philippe; Agbulut, Onnik

    2016-02-01

    Limited data are available on the effects of stem cells in non-ischemic dilated cardiomyopathy (DCM). Since the diffuse nature of the disease calls for a broad distribution of cells, this study investigated the scaffold-based delivery of human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) in a mouse model of DCM. Nanofibrous scaffolds were produced using a clinical grade atelocollagen which was electrospun and cross-linked under different conditions. As assessed by scanning electron microscopy and shearwave elastography, the optimum crosslinking conditions for hiPS-CM colonization proved to be a 10% concentration of citric acid crosslinking agent and 150 min of post-electrospinning baking. Acellular collagen scaffolds were first implanted in both healthy mice and those with induced DCM by a cardiac-specific invalidation of serum response factor (SRF). Seven and fourteen days after implantation, the safety of the scaffold was demonstrated by echocardiography and histological assessments. The subsequent step of implantation of the scaffolds seeded with hiPS-CM in DCM induced mice, using cell-free scaffolds as controls, revealed that after fourteen days heart function decreased in controls while it remained stable in the treated mice. This pattern was associated with an increased number of endothelial cells, in line with the greater vascularity of the scaffold. Moreover, a lesser degree of fibrosis consistent with the upregulation of several genes involved in extracellular matrix remodeling was observed. These results support the interest of the proposed hiPS-CM seeded electrospun scaffold for the stabilization of the DCM outcome with potential for its clinical use in the future. PMID:26708641

  9. Full-Length Fibronectin Drives Fibroblast Accumulation at the Surface of Collagen Microtissues during Cell-Induced Tissue Morphogenesis

    PubMed Central

    Foolen, Jasper; Shiu, Jau-Ye; Mitsi, Maria; Zhang, Yang; Chen, Christopher S.; Vogel, Viola

    2016-01-01

    Generating and maintaining gradients of cell density and extracellular matrix (ECM) components is a prerequisite for the development of functionality of healthy tissue. Therefore, gaining insights into the drivers of spatial organization of cells and the role of ECM during tissue morphogenesis is vital. In a 3D model system of tissue morphogenesis, a fibronectin-FRET sensor recently revealed the existence of two separate fibronectin populations with different conformations in microtissues, i.e. ‘compact and adsorbed to collagen’ versus ‘extended and fibrillar’ fibronectin that does not colocalize with the collagen scaffold. Here we asked how the presence of fibronectin might drive this cell-induced tissue morphogenesis, more specifically the formation of gradients in cell density and ECM composition. Microtissues were engineered in a high-throughput model system containing rectangular microarrays of 12 posts, which constrained fibroblast-populated collagen gels, remodeled by the contractile cells into trampoline-shaped microtissues. Fibronectin’s contribution during the tissue maturation process was assessed using fibronectin-knockout mouse embryonic fibroblasts (Fn-/- MEFs) and floxed equivalents (Fnf/f MEFs), in fibronectin-depleted growth medium with and without exogenously added plasma fibronectin (full-length, or various fragments). In the absence of full-length fibronectin, Fn-/- MEFs remained homogenously distributed throughout the cell-contracted collagen gels. In contrast, in the presence of full-length fibronectin, both cell types produced shell-like tissues with a predominantly cell-free compacted collagen core and a peripheral surface layer rich in cells. Single cell assays then revealed that Fn-/- MEFs applied lower total strain energy on nanopillar arrays coated with either fibronectin or vitronectin when compared to Fnf/f MEFs, but that the presence of exogenously added plasma fibronectin rescued their contractility. While collagen

  10. The IκB kinase inhibitor ACHP strongly attenuates TGFβ1-induced myofibroblast formation and collagen synthesis.

    PubMed

    Mia, Masum M; Bank, Ruud A

    2015-12-01

    Excessive accumulation of a collagen-rich extracellular matrix (ECM) by myofibroblasts is a characteristic feature of fibrosis, a pathological state leading to serious organ dysfunction. Transforming growth factor beta1 (TGFβ1) is a strong inducer of myofibroblast formation and subsequent collagen production. Currently, there are no remedies for the treatment of fibrosis. Activation of the nuclear factor kappa B (NF-κB) pathway by phosphorylating IκB with the enzyme IκB kinase (IKK) plays a major role in the induction of fibrosis. ACHP {2-Amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-(4-piperidinyl)-3 pyridinecarbonitrile}, a selective inhibitor of IKK, prohibits the activation of the NF-κB pathway. It is not known whether ACHP has potential anti-fibrotic properties. Using adult human dermal and lung fibroblasts we have investigated whether ACHP has the ability to inhibit the TGFβ1-induced transition of fibroblasts into myofibroblasts and its excessive synthesis of ECM. The presence of ACHP strongly suppressed the induction of the myofibroblast markers alpha-smooth muscle actin (αSMA) and SM22α, as well as the deposition of the ECM components collagen type I and fibronectin. Furthermore, post-treatment with ACHP partly reversed the expression of αSMA and collagen type I production. Finally, ACHP suppressed the expression of the three collagen-modifying enzymes lysyl hydroxylase (PLOD1, PLOD2 and PLOD3) in dermal fibroblasts, but did not do so in lung fibroblasts. We conclude that the IKK inhibitor ACHP has potent antifibrotic properties, and that the NF-κB pathway plays an important role in myofibroblast biology. PMID:26337045

  11. Aqueous and Methanolic Extracts of Caulerpa mexicana Suppress Cell Migration and Ear Edema Induced by Inflammatory Agents

    PubMed Central

    Bitencourt, Mariana Angelica Oliveira; Dantas, Gracielle Rodrigues; Lira, Daysianne Pereira; Barbosa-Filho, Jose Maria; de Miranda, George Emmanuel Cavalcanti; de Oliveira Santos, Barbara Viviana; Souto, Janeusa Trindade

    2011-01-01

    The regulation of the inflammatory response is essential to maintaining homeostasis. Several studies have investigated new drugs that may contribute to avoiding or minimizing excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexicana on models inflammation. In mice, the inflammatory peritonitis model is induced by zymosan. Previous treatment of mice with aqueous and methanolic extracts of C. mexicana was able to suppress the cell migration to the peritoneal cavity, in a time-dependent but not in a dose-dependent manner. The treatment of mice with C. mexicana extracts also decreased the xylene-induced ear edema, exerting strong inhibitory leukocyte migration elicited by zymosan into the air pouch. We concluded that administration of the extracts resulted in a reduction of cell migration to different sites as well as a decrease in edema formation induced by chemical irritants. This study demonstrates for the first time the anti-inflammatory effect of aqueous and methanolic extracts from the green marine algae Caulerpa mexicana. PMID:21892348

  12. [Inner Ear Hearing Loss].

    PubMed

    Hesse, G

    2016-06-01

    Hearing loss is one of the most dominant handicaps in modern societies, which additionally very often is not realized or not admitted. About one quarter of the general population suffers from inner ear hearing loss and is therefore restricted in communicational skills. Demographic factors like increasing age play an important role as well as environmental influences and an increasing sound and noise exposure especially in leisure activities. Thus borders between a "classical" presbyacusis - if it ever existed - and envirionmentally induced hearing loss disappear. Today restrictions in hearing ability develop earlier in age but at the same time they are detected and diagnosed earlier. This paper can eventually enlighten the wide field of inner ear hearing loss only fragmentarily; therefore mainly new research, findings and developments are reviewed. The first part discusses new aspects of diagnostics of inner ear hearing loss and different etiologies. PMID:27259171

  13. Lysyl hydroxylase 2 induces a collagen cross-link switch in tumor stroma

    PubMed Central

    Chen, Yulong; Terajima, Masahiko; Yang, Yanan; Sun, Li; Ahn, Young-Ho; Pankova, Daniela; Puperi, Daniel S.; Watanabe, Takeshi; Kim, Min P.; Blackmon, Shanda H.; Rodriguez, Jaime; Liu, Hui; Behrens, Carmen; Wistuba, Ignacio I.; Minelli, Rosalba; Scott, Kenneth L.; Sanchez-Adams, Johannah; Guilak, Farshid; Pati, Debananda; Thilaganathan, Nishan; Burns, Alan R.; Creighton, Chad J.; Martinez, Elisabeth D.; Zal, Tomasz; Grande-Allen, K. Jane; Yamauchi, Mitsuo; Kurie, Jonathan M.

    2015-01-01

    Epithelial tumor metastasis is preceded by an accumulation of collagen cross-links that heighten stromal stiffness and stimulate the invasive properties of tumor cells. However, the biochemical nature of collagen cross-links in cancer is still unclear. Here, we postulated that epithelial tumorigenesis is accompanied by changes in the biochemical type of collagen cross-links. Utilizing resected human lung cancer tissues and a p21CIP1/WAF1-deficient, K-rasG12D-expressing murine metastatic lung cancer model, we showed that, relative to normal lung tissues, tumor stroma contains higher levels of hydroxylysine aldehyde–derived collagen cross-links (HLCCs) and lower levels of lysine aldehyde–derived cross-links (LCCs), which are the predominant types of collagen cross-links in skeletal tissues and soft tissues, respectively. Gain- and loss-of-function studies in tumor cells showed that lysyl hydroxylase 2 (LH2), which hydroxylates telopeptidyl lysine residues on collagen, shifted the tumor stroma toward a high-HLCC, low-LCC state, increased tumor stiffness, and enhanced tumor cell invasion and metastasis. Together, our data indicate that LH2 enhances the metastatic properties of tumor cells and functions as a regulatory switch that controls the relative abundance of biochemically distinct types of collagen cross-links in the tumor stroma. PMID:25664850

  14. [THE INFLUENCE OF HYDROGEN SULFIDE ON COLLAGEN-INDUCED AGGREGATION OF HUMAN PLATELETS].

    PubMed

    Petrova, I V; Trubacheva, O A; Mangataeva, O S; Suslova, T E; Kovalev, I V; Gusakova, S V

    2015-10-01

    Study the impact of hydrogen sulfide on collagen-induced platelet aggregation from healthy donors and patients with type 2 diabetes. In healthy individuals, in contrast to patients with type 2 diabetes, NaHS significantly inhibited platelet aggregation. Activators of cAMP signaling (forskolin and phosphodiesterase inhibitor) significantly reduced platelet aggregation in both groups of examinees. NO-synthase inhibitors increased platelet aggregation in healthy volunteers, but not in patients with type 2 diabetes. The presence of H2S donor did not alter the extent of platelet aggregation at high concentrations of cAMP or decreased production of nitric oxide. It is assumed that the antiplatelet effect of H2S is not associated with the effect on the signal system, mediated cAMP or nitric oxide. Change H2S-dependent regulation of platelet aggregation in patients with type 2 diabetes is caused by disorders have been reported with this disease: the increase of intracellular calcium ion concentration, oxidative damage to proteins, hyperhomocysteinemia, glycosylation of key proteins involved in this process. PMID:26827498

  15. Suppression of interleukin 17 production by Brazilian propolis in mice with collagen-induced arthritis.

    PubMed

    Tanaka, Mayuri; Okamoto, Yoshihiro; Fukui, Takashi; Masuzawa, Toshiyuki

    2012-02-01

    Propolis is a resinous substance collected by honeybees from leaf buds and cracks in the bark of various plants. Propolis has been reported to have immunomodulatory activity. We hypothesized that propolis would be able to reduce the disease severity of rheumatoid arthritis. We evaluated the effect of Brazilian propolis ethanolic extract on the pathogenesis of collagen-induced arthritis (CIA) in mice. Mice fed propolis exhibited significant lower clinical arthritis scores than those fed the control diet. To investigate the mechanism of the effect of propolis on CIA mice, we examined interleukin-17 (IL-17) production in CIA mice fed propolis using an enzyme-linked immunospot assay and flow cytometric analysis. The numbers of IL-17-producing cells in the CIA mice fed propolis were significantly decreased. To determine direct influence of propolis on cytokine production, splenocytes were stimulated with phorbol myristate acetate in the presence of propolis extract in vitro. Concentration-dependent declines in IL-17 expression were observed by ELISA and real-time PCR methods. We further found that propolis significantly inhibited the differentiation of Th17 cells from murine splenocytes in a concentration-dependent manner. Taken together, our results may provide a new light on the potential mechanism of the immunosuppressive and anti-inflammatory effects of propolis. PMID:21861090

  16. Polymorphism of the MHC class II Eb gene determines the protection against collagen-induced arthritis

    SciTech Connect

    Gonzalez-Gay, M.A.; Zanelli, E.; Krco, C.J.

    1995-05-01

    Collagen-induced arthritis (CIA) is an animal model of auto immune polyarthritis, sharing similarities with rheumatoid arthritis (RA). Paradoxally, susceptibility to mouse CIA is controlled by the H2A loci (DQ homologous) while RA is linked to HLA.DR genes (H2E homologous). We recently showed that the E{beta}{sup d} molecule prevents CIA development in susceptible H2{sup q} mice. We addressed the question of whether H2Eb polymorphism will influence CIA incidence as HLA.DRB1 polymorphism does in RA. In F{sub 1} mice, only H2Eb{sup d} and H2Eb{sup s} molecules showed protection. Using recombinant B10.RDD (Eb{sup d/b}) mice, we found that CIA protection was mediated by the first domain of the E{beta}{sup d} molecule. Using peptides covering the third hypervariable region of the E{beta} chain, we found a perfect correlation between presentation of E{beta} peptides by the H2A{sup q} molecule and protection on CIA. Therefore, the mechanism by which H2Eb protects against CIA seems to rely on the affinity of E{beta} peptides for the H2A{sup q} molecule. 35 refs., 2 figs., 3 tabs.

  17. Repeated Electroacupuncture Persistently Elevates Adenosine and Ameliorates Collagen-Induced Arthritis in Rats

    PubMed Central

    Ye, Tian-shen; Du, Zhong-heng; Li, Zhi-hui; Xie, Wen-xia; Huang, Ka-te; Chen, Yong; Chen, Zhou-yang; Hu, Huan; Wang, Jun-lu; Fang, Jian-Qiao

    2016-01-01

    The aim of this paper was to investigate the effect of repeated electroacupuncture (EA) over 21 days on the adenosine concentration in peripheral blood of rats with collagen-induced arthritis (CIA). Wistar rats were divided into three groups of 6 animals each: sham-control, CIA-control, and CIA-EA. We determined the adenosine concentration in peripheral blood and assessed pathological changes of ankle joints. Quantitative reverse-transcription-polymerase chain reaction was used to determine mRNA levels of ecto-5′-nucleotidase (CD73), adenosine deaminase (ADA), and tumor necrosis factor-alpha (TNF-α). Immunohistochemical staining was used to detect expression of ADA and CD73 in synovial tissue. Repeated EA treatment on CIA resulted in the persistence of high concentrations of adenosine in peripheral blood, significantly reduced pathological scores, TNF-α mRNA concentrations, and synovial hyperplasia. Importantly, EA treatment led to a significant increase in CD73 mRNA levels in peripheral blood but was associated with a decrease of CD73 immunostaining in synovial tissue. In addition, EA treatment resulted in a significant decrease of both ADA mRNA levels in peripheral blood and ADA immunostaining in synovial tissue. Thus, repeated EA treatment exerts an anti-inflammatory and immunoregulatory effect on CIA by increasing the concentration of adenosine. The mechanism of EA action may involve the modulation of CD73 and ADA expression levels. PMID:26941824

  18. Retrovirus-induced insertional mutagenesis: mechanism of collagen mutation in Mov13 mice.

    PubMed Central

    Barker, D D; Wu, H; Hartung, S; Breindl, M; Jaenisch, R

    1991-01-01

    The Mov13 mouse strain carries a mutation in the alpha 1(I) procollagen gene which is due to the insertion of a Moloney murine leukemia provirus into the first intron. This insertion results in the de novo methylation of the provirus and flanking DNA, the alteration of chromatin structure, and the transcriptional inactivity of the collagen promoter. To address the mechanism of mutagenesis, we reintroduced a cloned and therefore demethylated version of the Mov13 mutant allele into mouse fibroblasts. The transfected gene was not transcribed, indicating that the transcriptional defect was not due to the hypermethylation. Rather, this result strongly suggests that the mutation is due to the displacement or disruption of cis-acting regulatory DNA sequences within the first intron. We also constructed a Mov13 variant allele containing a single long terminal repeat instead of the whole provirus. This construct also failed to express mRNA, indicating that the Mov13 mutation does not revert by provirus excision as has been observed for other retrovirus-induced mutations. Images PMID:1922037

  19. Ear Plastic Surgery

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  20. Autoimmune Inner Ear Disease

    MedlinePlus

    ... Find an ENT Doctor Near You Autoimmune Inner Ear Disease Autoimmune Inner Ear Disease Patient Health Information ... with a hearing loss. How Does the Healthy Ear Work? The ear has three main parts: the ...

  1. Better Ear Health

    MedlinePlus

    ... Calendar Find an ENT Doctor Near You Better Ear Health Better Ear Health Patient Health Information News ... often helpful to those with this condition. Swimmer’s Ear An infection of the outer ear structures caused ...

  2. How the Ear Works

    MedlinePlus

    ... Find an ENT Doctor Near You How the Ear Works How the Ear Works Patient Health Information News media interested in ... public relations staff at newsroom@entnet.org . The ear has three main parts: the outer ear (including ...

  3. Cosmetic ear surgery

    MedlinePlus

    Otoplasty; Ear pinning; Ear surgery - cosmetic; Ear reshaping; Pinnaplasty ... Cosmetic ear surgery may be done in the surgeon's office, an outpatient clinic, or a hospital. It can be performed under ...

  4. Somatic Antigens of Tropical Liver Flukes Ameliorate Collagen-Induced Arthritis in Wistar Rats

    PubMed Central

    Khan, Yasir Akhtar; Umar, Sadiq; Abidi, Syed M. A.

    2015-01-01

    Parasitic helminths polarize immune response of their vertebrate hosts towards anti-inflammatory Th2 type and therefore it is hypothesized that they may suppress the inflammatory conditions in autoimmune disorders. The present study was undertaken to investigate in vivo immunomodulatory and therapeutic potential of somatic antigens (Ag) of liver infecting digenetic trematodes [Fasciola gigantica (Fg) and Gigantocotyle explanatum (Ge)] in collagen-induced arthritic (CIA) Wistar rats. The CIA rats were administered subcutaneously with different doses (50 μg, 100 μg and 150 μg) of somatic antigens of Fg and Ge, daily for 21 days, the time period required to establish infection in natural host (Bubalus bubalis). Thereafter, the control, diseased and treated rats were compared for different parameters viz. hind paw thickness; serum interleukins, IL-4 and IL-10, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ); expression level of matrix metalloproteinases (MMPs) -2, -9, -13 and nitric oxide (NO) in knee joints and patellar morphology. The CIA rats treated with different antigens, Fg-Ag and Ge-Ag, show significant amelioration of the disease by down regulation of serum TNF-α and IFN-γ (p< 0.05) and upregulation of IL-4 and IL-10 cytokines (p< 0.05); inhibition (p< 0.05) of MMPs (-2,-9,-13) and NO in knee joints and improved patellar morphology with decreased synovial hypertrophy and reduced infiltration of ploymorphonuclear cells. The activity of pro as well as active MMPs (-2 and -9) and active MMP-13 in knee joints of CIA rats was very high compared to the control and treatment groups, suggesting the extent of collagen degradation in CIA rats. Interestingly, the highest dose (150 μg) of Ge-Ag almost wiped out MMP-13 expression. The overall findings suggest that the somatic proteins of Ge-Ag appeared to be therapeutically more effective than Fg-Ag, reflecting interspecific molecular differences which could contribute to the ability of these worms to

  5. Hesperidin inhibits collagen-induced arthritis possibly through suppression of free radical load and reduction in neutrophil activation and infiltration.

    PubMed

    Umar, Sadiq; Kumar, Anubhav; Sajad, Mir; Zargan, Jamil; Ansari, Meraj; Ahmad, Sayeed; Katiyar, Chandra Kant; Khan, Haider A

    2013-03-01

    Rheumatoid arthritis is a chronic inflammatory disease characterized by the destruction of articular cartilage and bone in a chronic phase. Pathology of rheumatoid arthritis suggests autoimmunity linked to inflammation. In our study, rheumatoid arthritis was induced in Wistar rats by intradermal injections of 100 μl of emulsion containing bovine type II collagen in complete Freund's adjuvant at the base of the tail. Disease developed about 13 ± 1 days after immunization and treatment with hesperidin (HES) at a dose of 160 mg kg(-1) body weight was given after onset of disease daily until 20th day. The effect of treatment in the rats was monitored by clinical scoring, biochemical parameters and histological evaluations in joints. A steady increase in the articular elastase, nitric oxide and lipid peroxidation was observed in joints of arthritic rats as compared to control, whereas a significant decrease in reduced glutathione, superoxide dismutase activity and catalase was observed in collagen-induced arthritis rats as compared to control group. The results from the present work indicate that the treatment with hesperidin was effective in bringing about significant changes on all the parameters studied in collagen-induced arthritis rats. These data confirm that erosive destruction of the joint cartilage in collagen-induced arthritis is due free radicals released by activated neutrophils and produced by other biochemical pathways. In the present study, an attempt has been made to amelioration of the disease process by a natural product. These results suggest that oral administration of HES could be effective for treating human RA patients. PMID:22527139

  6. Autoantibody profile in the experimental model of scleroderma induced by type V human collagen

    PubMed Central

    Callado, Maria R M; Viana, Vilma S T; Vendramini, Margarete B G; Leon, Elaine P; Bueno, Cleonice; Velosa, Ana P P; Teodoro, Walcy R; Yoshinari, Natalino H

    2007-01-01

    The aim of this study is to evaluate the humoral autoimmune response in the experimental model of systemic sclerosis (SSc) induced by human type V collagen (huCol V). New Zealand rabbits were immunized with huCol V in Freund's complete adjuvant (FCA) and boosted twice with 15 days intervals with huCol V in Freund's incomplete adjuvant. Control groups included animals injected only with FCA or bovine serum albumin. Bleeding was done at days 0, 30, 75 and 120. Tissue specimens were obtained for histopathological investigation. Serological analysis included detection of antibodies against huCol V and anti-topoisomerase I (Anti-Scl70) by enzyme-linked immunosorbent assay, antinuclear antibodies (ANA) by indirect immunofluorescence, and rheumatoid factor (RF) by a latex agglutination test. Target antigens were characterized by immunoblot. Histological analysis revealed extracellular matrix remodeling with fibrosis and vasculitis. Anti-Scl70 and ANA were detected as early as 30 days in all huCol V animals. The universal ANA staining pattern was Golgi-like. This serum reactivity was not abolished by previous absorption with huCol V. Characterization of the target antigen by immunoblot revealed two major protein fractions of 175 000 and 220 000 MW. Similarly to ANA, there was a gradual increase of reactivity throughout the immunization and also it was not abolished by preincubation of serum samples with huCol V. RF testing was negative in hyperimmune sera. Conclusion: The production of autoantibodies, including anti-Scl70, a serological marker for SSc associated with histopathological alterations, validates huCol V induced-experimental model and brings out its potential for understanding the pathophysiology of SSc. PMID:17442023

  7. Treatment of Collagen-Induced Arthritis Using Immune Modulatory Properties of Human Mesenchymal Stem Cells.

    PubMed

    Park, Kyu-Hyung; Mun, Chin Hee; Kang, Mi-Il; Lee, Sang-Won; Lee, Soo-Kon; Park, Yong-Beom

    2016-01-01

    Mesenchymal stem cells (MSCs) have immune modulatory properties. We investigated the potential therapeutic effects of human bone marrow (BM)-, adipose tissue (AD)-, and cord blood (CB)-derived MSCs in an experimental animal model of rheumatoid arthritis (RA) and explored the mechanism underlying immune modulation by MSCs. We evaluated the therapeutic effect of clinically available human BM-, AD-, and CB-derived MSCs in DBA/1 mice with collagen-induced arthritis (CIA). CIA mice were injected intraperitoneally with three types of MSCs. Treatment control animals were injected with 35 mg/kg methotrexate (MTX) twice weekly. Clinical activity in CIA mice, degree of inflammation, cytokine expression in the joint, serum cytokine levels, and regulatory T cells (Tregs) were evaluated. Mice treated with human BM-, AD-, and CB-MSCs showed significant improvement in clinical joint score, comparable to MTX-treated mice. Histologic examination showed greatly reduced joint inflammation and damage in MSC-treated mice compared with untreated mice. Microcomputed tomography also showed little joint damage in the MSC-treated group. MSCs significantly decreased serum interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, and interferon-γ and increased IL-10 and transforming growth factor-β levels. Tregs were increased in mice treated with MSCs compared to untreated or MTX-treated mice. Human BM-, AD-, and CB-MSCs significantly suppressed joint inflammation in CIA mice. The cells decreased proinflammatory cytokines and upregulated anti-inflammatory cytokines and induced Tregs. Therefore, our study suggests that the use of human BM-, AD-, and CB-MSCs could be an effective therapeutic approach for RA. PMID:25853338

  8. Biosynthesis of collagen crosslinks. III. In vivo labeling and stability of lung collagen in rats with bleomycin-induced pulmonary fibrosis

    SciTech Connect

    Last, J.A.; Reiser, K.M. )

    1989-08-01

    Rats were injected intraperitoneally with 1 mCi (each) of (3H)lysine at Day 11 of neonatal life to label their lung collagen. Five weeks later, half of the animals were given an intratracheal injection of 1.5 U of bleomycin sulfate via a tracheostomy; control animals received saline intratracheally by the same technique. Age-matched groups of control and bleomycin-treated rats were killed, and their lung collagen was analyzed at zero (control animals only), 1, 2, 4, 6, and 10 wk after bleomycin administration, a time course appropriate for development of pulmonary fibrosis in this animal model. We measured radioactivity in hydroxylysine and in the difunctional collagen crosslinks hydroxylysinonorleucine and dihydroxylysinonorleucine at each time point. No evidence of breakdown of this pool of mature, preformed collagen was observed in lungs of either the control or the bleomycin-treated rats. We also measured the total lung content of hydroxypyridinium, a trifunctional collagen crosslink, by its intrinsic fluorescence. There was no evidence of collagen degradation in lungs of either group of rats by this criterion either. We conclude that there is no biochemically detectable turnover of mature lung collagen, defined as that pool of lung collagen that is obligatorily extracellular (i.e., crosslinked and containing labeled hydroxylysine from an injection of precursor 5 to 15 wk earlier), in either normal rat lungs or lungs of rats made fibrotic with bleomycin. Statistical analysis of the data suggests that our methodology was sensitive and precise enough to have detected turnover of less than 0.5% of lung collagen per day, some 20-fold less than estimates of lung collagen turnover that have been suggested to be occurring in vivo by others using different techniques and presumably studying different pools of lung collagen.

  9. Methacrylation Induces Rapid, Temperature-Dependent, Reversible Self-Assembly of Type-I Collagen

    PubMed Central

    2015-01-01

    Type-I collagen self-assembles into a fibrillar gel at physiological temperature and pH to provide a cell-adhesive, supportive, structural network. As such, it is an attractive, popular scaffold for in vitro evaluations of cellular behavior and for tissue engineering applications. In this study, type-I collagen is modified to introduce methacrylate groups on the free amines of the lysine residues to create collagen methacrylamide (CMA). CMA retains the properties of collagen such as self-assembly, biodegradability, and natural bioactivity but is also photoactive and can be rapidly cross-linked or functionalized with acrylated molecules when irradiated with ultraviolet light in the presence of a photoinitiator. CMA also demonstrates unique temperature-dependent behavior. For natural type-I collagen, the overall structure of the fiber network remains largely static over time scales of a few hours upon heating and cooling at temperatures below its denaturation point. CMA, however, is rapidly thermoreversible and will oscillate between a liquid macromer suspension and a semisolid fibrillar hydrogel when the temperature is modulated between 10 and 37 °C. Using a series of mechanical, scattering, and spectroscopic methods, we demonstrate that structural reversibility is manifest across multiple scales from the protein topology of the triple helix up through the rheological properties of the CMA hydrogel. Electron microscopy imaging of CMA after various stages of heating and cooling shows that the canonical collagen-like D-periodic banding ultrastructure of the fibers is preserved. A rapidly thermoreversible collagen-based hydrogel is expected to have wide utility in tissue engineering and drug delivery applications as a biofunctional, biocompatible material. Thermal reversibility also makes CMA a powerful model for studying the complex process of hierarchical collagen self-assembly. PMID:25208340

  10. How can the auditory efferent system protect our ears from noise-induced hearing loss? Let us count the ways

    NASA Astrophysics Data System (ADS)

    Marshall, Lynne; Miller, Judi A. Lapsley

    2015-12-01

    It is a cause for some debate as to how the auditory olivocochlear (OC) efferent system could protect hearing from noise trauma. In this review, we examined physiological research to find mechanisms that could effectively attenuate the response to sound. For each purported mechanism, we indicate which part of the OC-efferent system is responsible for the function and the site of action. These mechanisms include basilar-membrane phase shifts at high stimulus levels; changes in outer-hair-cell stiffness and phase lag associated with efferent slow effects; small decreases in endocochlear potentials causing small decreases in outer- and inner-hair-cell output; low-spontaneous-rate and medium-spontaneous-rate fibers showing OC-induced decrements at high levels; auditory-nerve initial-peak reduction; OC effect increasing over minutes; cholinergic activation of anti-apoptotic pathways; and anti-excitotoxicity. There are clearly multiple opportunities for the OC-efferent system to protect the inner ear from noise trauma. From further exploration into the mechanisms outlined here, as well as to-be-discovered mechanisms, we will gain a greater understanding of the protective nature of the OC-efferent system. These findings could aid our ability to design better predictive tests for people at risk for noise-induced hearing loss.

  11. Platelet receptor recognition and cross-talk in collagen-induced activation of platelets.

    PubMed

    Farndale, R W; Slatter, D A; Siljander, P R-M; Jarvis, G E

    2007-07-01

    Comprehensive mapping of protein-binding sites within human collagen III has allowed the recognition motifs for integrin alpha(2)beta(1) and VWF A3 domain to be identified. Glycoprotein VI-binding sites are understood, although less well defined. This information, together with recent developments in understanding collagen fiber architecture, and crystal structures of the receptor collagen-binding domains, allows a coherent model for the interaction of collagen with the platelet surface to be developed. This complements our understanding of the orchestration of receptor presentation by membrane microdomains, such that the polyvalent collagen surface may stabilize signaling complexes within the heterogeneous receptor composition of the lipid raft. The ensuing interactions lead to the convergence of signals from each of the adhesive receptors, mediated by FcR gamma-chain and/or FcgammaRIIa, leading to concerted and co-operative platelet activation. Each receptor has a shear-dependent role, VWF/GpIb essential at high shear, and alpha(2)beta(1) at low and intermediate shear, whilst GpVI provides core signals that contribute to enhanced integrin affinity, tighter binding to collagen and consequent platelet activation. PMID:17635730

  12. Nanostructural and nanomechanical responses of collagen fibrils in the collagenase-induced Achilles tendinitis rat model.

    PubMed

    Lee, Gi-Ja; Choi, Samjin; Chon, Jinmann; Yoo, Seung Don; Kim, Hee-Sang; Park, Hun-Kuk; Chung, Joo Ho

    2013-11-01

    Achilles tendons are vulnerable to acute or chronic injuries that lead to inflammation. We investigated nanostructural and nanomechanical changes in collagen fibrils from rat Achilles tendons over a period of 9 weeks after injury using atomic force microscopy (AFM). To evaluate the nanostructural changes in Achilles tendons, we measured the diameter and D-banding of collagen fibrils by AFM. And the adhesion forces, which were related to cross-linking of collagen, were calculated from the retraction process of a force-distance curve. We successfully observed the time course of changes in collagen fibrils during healing using AFM. The diameters and D-banding in healed tendons were similar to those of uninjured tendons at 9 weeks after injury, but the adhesion forces remained different from those of uninjured tendons. Our AFM results depicted the minute changes in Achilles tendon surface by natural healing quite well, even drawbacks to naturally healed tendon. Understanding changes in collagen cross-linking and structure while healing will lead to better understanding of healing mechanisms and subsequent improvements in treatment. And AFM can be applied as powerful tool to evaluate structural and property changes in collagen fibrils before and after injury and/or treatment in Achilles tendon. PMID:24245243

  13. An essential role for mast cells as modulators of neutrophils influx in collagen-induced arthritis in the mouse

    PubMed Central

    Pimentel, Tatiana Aparecida; Sampaio, Andrxsé Luiz Franco; D’Acquisto, Fulvio; Perretti, Mauro; Oliani, Sonia Maria

    2012-01-01

    Mast cells are involved in immune disorders so that many of the proinflammatory and tissue destructive mediators produced by these cells have been implicated in the pathogenesis of rheumatoid arthritis. This scenario prompted us to investigate the correlation between mast cell degranulation and neutrophil influx within the digits and knees joints of arthritic mice assessing what could be the functional role(s) of joint mast cells in the response to collagen immunization. DBA/1J mice were submitted to collagen-induced arthritis and disease was assessed on day 21, 32 and 42 post-immunization. Pharmacological treatment with the glucocorticoid prednisolone, commonly used in the clinic, and nedocromil, a mast cell stabilizer, was performed from day 21 to 30. Arthritis developing after immunization gradually increased up to day 42. Neutrophil infiltration peaked on day 32 and 21, in the digits and knees, respectively, showing an unequal pattern of recruitment between these tissues. This difference emerged for mast cell they peaked in the digits on day 21, but a higher degree of degranulation could be measured in the knee joints. Uneven modulation of arthritis occurred after treatment of mice with prednisolone or nedocromil. Neutrophils migration to the tissue was reduced after both therapies, but only prednisolone augmented mast cell migration to the joints. Nedocromil exerted inhibitory properties both on mast cell proliferation and migration, more effectively on the digit joints. Thus, collagen induced an inflammatory process characterized by tissue mast cells activation and degranulation, suggesting a potential driving force in propagating inflammatory circuits yielding recruitment of neutrophils. However, the different degree of affected joint involvement suggests a time-related implication of digits and knees during collagen-induced arthritis development. These results provide evidence for local alterations whereby mast cells contribute to the initiation of

  14. Puerarin attenuates inflammation and oxidation in mice with collagen antibody-induced arthritis via TLR4/NF-κB signaling.

    PubMed

    Wang, Changxing; Wang, Weidong; Jin, Xiaping; Shen, Jianguo; Hu, Weifeng; Jiang, Tao

    2016-08-01

    Puerarin is an important active ingredient in the root of kudzu vine due to its pharmacological properties. The aim of the present study is to contribute to the existing knowledge of the effect of puerarin in the attenuation of inflammation and oxidation in mice with collagen antibody-induced arthritis via toll‑like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling. Arthritis was induced using injection of anti‑type II collagen antibodies. Treatment with puerarin was observed to significantly decrease clinical scoring of the collagen antibody‑induced arthritis and suppress oxidative stress and the inflammatory response in mice. Furthermore, puerarin was demonstrated to inhibit mRNA expression of matrix metalloproteinase‑9 and protein expression of TLR4 following collagen antibody-induced arthritis in mice. The effect of puerarin may be associated with the suppression of NF‑κB activity in collagen antibody‑induced arthritis mice. Furthermore, upregulation of phosphorylated (p)‑Janus kinase 2 and p‑signal transducer and activator of transcription 3 protein expression was suppressed by puerarin. The results of the present study indicate, for the first time, the effect of puerarin to attenuate inflammation and oxidation in mice with collagen antibody‑induced arthritis via TLR4/NF-κB signaling. PMID:27278131

  15. Radiation-Induced Middle Ear and Mastoid Opacification in Skull Base Tumors Treated With Radiotherapy

    SciTech Connect

    Walker, Gary V.; Ahmed, Salmaan; Allen, Pamela; Gidley, Paul W.; Woo, Shiao Y.; DeMonte, Franco; Chang, Eric L.; Mahajan, Anita

    2011-12-01

    Purpose: To assess the incidence of middle ear (ME) pathology in patients treated with radiotherapy (RT) for skull base tumors. Methods and Materials: A retrospective analysis of 61 patients treated with RT between 2003 and 2008 for skull base tumors was conducted. Clinical outcomes and demographics were reviewed. Dose-volume histogram analysis was performed on the eustachian canal (EC), ME, mastoid air cells, vestibular apparatus, cochlea, internal auditory canal, lateral and posterior nasopharynx, and temporal lobes to relate doses to symptoms and radiographic change. Otomastoid opacification was rated 0 (none), 1 (mild), 2 (moderate), and 3 (severe) by a neuroradiologist blinded to clinical outcomes and doses. Results: The median prescribed dose was 50.4 Gy (range, 14-74 Gy). The ME mean dose was 14 Gy and 34 Gy for Grade 0-1 and 2-3 opacification, respectively (p < 0.0001). The mean mastoid dose was 10 Gy and 26 Gy for Grade 0-1 and 2-3, respectively (p < 0.0001). The mean EC dose was 17 Gy and 32 Gy for Grade 0-1 and 2-3, respectively (p = 0.0001). Otomastoid opacification resolved in 17 of 40 patients (42.5%), at a mean of 17 months after RT (range, 2-45 months). Otomastoid opacification persisted in 23 of 40 patients (57.5%), with a mean follow-up of 23 months (range, 2-55 months). Multivariate analysis showed that mastoid dose >30 Gy (odds ratio = 28.0, p < 0.001) and posterior nasopharynx dose of >30 Gy (odds ratio = 4.9, p = 0.009) were associated with Grade 2-3 effusions, whereas other factors including dose to EC and ME were not significant. Conclusions: A mean RT dose >30 Gy to the mastoid air cells or posterior nasopharynx is associated with increased risk of moderate to severe otomastoid opacification, which persisted in more than half of patients at 2-year follow-up.

  16. Lupeol acetate ameliorates collagen-induced arthritis and osteoclastogenesis of mice through improvement of microenvironment.

    PubMed

    Wang, Wei-Hsun; Chuang, Hui-Yen; Chen, Chien-Hui; Chen, Wun-Ke; Hwang, Jeng-Jong

    2016-04-01

    Lupeol has been shown with anti-inflammation and antitumor capability, however, the poor bioavailability limiting its applications in living subjects. Lupeol acetate (LA), a derivative of lupeol, shows similar biological activities as lupeol but with better bioavailability. Here RAW 264.7 cells and bone marrow-derived macrophages (BMDMs) stimulated by lipopolysaccharide (LPS) were treated with 0-80μM of LA, and assayed for TNF-α, IL-1β, COX-2, MCP-1 using Western blotting. Moreover, osteoclatogenesis was examined with reverse transcription PCR (RT-PCR) and tartrate-resistant acid phosphatase (TRAP) staining. For in vivo study, collagen-induced arthritis (CIA)-bearing DBA/1J mice were randomly separated into three groups: vehicle, LA-treated (50mg/kg) and curcumin-treated (100mg/kg). Therapeutic efficacies were assayed by the clinical score, expression levels of serum cytokines including TNF-α and IL-1β, (18)F-fluorodeoxyglucose ((18)F-FDG) microPET/CT and histopathology. The results showed that LA could inhibit the activation, migration, and formation of osteoclastogenesis of macrophages in a dose-dependent manner. In RA-bearing mice, the expressions of inflammation-related cytokines were suppressed, and clinical symptoms and bone erosion were ameliorated by LA. The accumulation of (18)F-FDG in the joints of RA-bearing mice was also significantly decreased by LA. The results indicate that LA significantly improves the symptoms of RA by down-regulating expressions of inflammatory cytokines and osteoclastogenesis. PMID:27044833

  17. Pharmacokinetics, pharmacodynamics, and toxicities of methotrexate in healthy and collagen-induced arthritic rats

    PubMed Central

    Liu, Dong-Yang; Lon, Hoi-Kei; Wang, Yan-Lin; DuBois, Debra C.; Almon, Richard R.; Jusko, William J.

    2013-01-01

    Methotrexate (MTX) is an anchor drug used to treat rheumatoid arthritis (RA), but responsiveness is variable in effectiveness and toxicity. Methotrexate and its polyglutamate conjugates (MTXPGn) in red blood cells (RBC) have been associated with patient response. In the current study, 13 collagen-induced arthritic (CIA) rats and 12 healthy rats were given subcutaneous doses of either saline or 0.3 or 1.5 mg/kg per 2 days of MTX from day 21 to 43 post-induction. Blood samples were obtained at various times to measure MTX in plasma, and MTX and MTXPGn in RBC. Effects on disease progression were indicated by body weight and paw size. After multiple-doses, RBC MTX reached steady-state (82.4 nM) within 4 days. The MTXPG2 and MTXPG3 in RBC kept increasing until the end of the study attaining 12.5 and 17.7 nM. Significant weight loss was observed after dosing of 1.5 mg/kg/2 days, whereas moderate effectiveness was observed after dosing of 0.3 mg/kg/2 days. A pharmacokinetic/ pharmacodynamic/disease (PK/PD/DIS) model with indirect mechanisms and transduction components incorporating plasma MTX, RBC MTX, and RBC MTXPGn concentrations, and paw size was developed using naïve data pooling and ADAPT 5. The PK/PD in CIA rats dosed at 0.3 mg/kg/2 days were captured well by our proposed model. MTX showed modest (Imaxd = 0.16) but sensitive (IC50d = 0.712 nM) effectiveness on paw edema. The higher dose produced toxicity. The proposed model offers improved understanding of MTX effects on rheumatoid arthritis. PMID:23456770

  18. Antibody-mediated delivery of IL-10 inhibits the progression of established collagen-induced arthritis

    PubMed Central

    Trachsel, Eveline; Bootz, Frank; Silacci, Michela; Kaspar, Manuela; Kosmehl, Hartwig; Neri, Dario

    2007-01-01

    The antibody-mediated targeted delivery of cytokines to sites of disease is a promising avenue for cancer therapy, but it is largely unexplored for the treatment of chronic inflammatory conditions. Using both radioactive and fluorescent techniques, the human monoclonal antibodies L19 and G11 (specific to two markers of angiogenesis that are virtually undetectable in normal adult tissues) were found to selectively localize at arthritic sites in the murine collagen-induced model of rheumatoid arthritis following intravenous (i.v.) administration. The same animal model was used to study the therapeutic action of the L19 antibody fused to the cytokines IL-2, tumour necrosis factor (TNF) and IL-10. Whereas L19–IL-2 and L19–TNF treatment led to increased arthritic scores and paw swellings, the fusion protein L19–IL-10 displayed a therapeutic activity, which was superior to the activity of IL-10 fused to an antibody of irrelevant specificity in the mouse. The anti-inflammatory cytokine IL-10 has been investigated for the treatment of patients with rheumatoid arthritis, but clinical development plans have been discontinued because of a lack of efficacy. Because the antigen recognised by L19 is strongly expressed at sites of arthritis in humans and identical in both mice and humans, it suggests that the fusion protein L19–IL-10 might help overcome some of the clinical limitations of IL-10 and provide a therapeutic benefit to patients with chronic inflammatory disorders, including arthritis. PMID:17261171

  19. Adding Water to the Mill: Olmesartan-Induced Collagenous Sprue-A Case Report and Brief Literature Review.

    PubMed

    Desruisseaux, Claudine; Bensoussan, Michaël; Désilets, Etienne; Tran, Hanh-Khiem; Arcand, Robert; Poirier, Germain; Wisniewski, Andrew; Manière, Thibaut

    2016-01-01

    Collagenous sprue (CS) is a distinct clinicopathological disorder histologically defined by a thickened subepithelial band (Freeman, 2011). It is a rare condition which has been recently observed in a significant proportion of sprue-like enteropathy associated with olmesartan, a novel entity described by Rubio-Tapia et al. in 2012. CS is historically associated with a poor prognosis (Marthey et al., 2014). However, histological and clinical improvements have been described in most studies with concomitant usage of corticosteroids and/or gluten-free diet (Marthey et al., 2014). We report a unique case of olmesartan-induced collagenous sprue in a 79-year-old man that showed complete histological and clinical remission with the sole withdrawal of the incriminating drug. The literature on this topic is briefly reviewed. PMID:27446843

  20. Inhibition of collagen, and thrombin-induced platelet aggregation by Lansberg's hognose pit viper (Porthidium lansbergii hutmanni) venom.

    PubMed

    López-Johnston, Juan C; de Bosch, Norma; Scannone, Héctor; Rodríguez-Acosta, Alexis

    2007-12-01

    The Porthidium genus is represented by the P. lansbergii rozei and P. lansbergii hutmanni (Plh) subspecies in Venezuela. The venom components of these have been little studied, probably due to the low incidence of reported accidents, although acute and serious local effects such as invasive edema and disseminated ecchymosis are present during human envenonation. The aim of this work was to characterize the in vitro effects of crude P. l. hutmanni venom, and its fractions, on platelet aggregation triggered by two physiologic agonists: thrombin and collagen. The effects of thrombin and collagen were observed on a platelet-rich plasma (PRP) solution (3 x 10(5) platelets/microL) using serial dilutions of P. l. hutmanni venom (0.625-40 microg). The crude venom was fractionated by anionic exchange chromatography and two peaks obtained. Crude venom and both fractions were highly inhibitory on platelet aggregation mediated by the two agonists. The anti-aggregating dose (AD(50)) for both agonists was determined. PRP collagen-triggered aggregation was most inhibited by the crude venom (AD(50) = 0.67 microg) when compared with PRP thrombin-triggered aggregation (AD(50) = 4.92 microg). Collagen-induced aggregation was more intensely inhibited by venom than thrombin-induced aggregation. In conclusion, to specify the inhibition mechanisms involved for each of the active components in the venom from these subspecies, we must characterize and purify the inhibitors of aggregation from P. l. hutmanni venom, with the purpose of suggesting new pharmacological substances to be incorporated into the therapeutic arsenal to treat hemostatic pathologies related to high levels of platelet aggregation. PMID:17486300

  1. Lipopolysaccharide-Induced Middle Ear Inflammation Disrupts the cochlear Intra-Strial Fluid–Blood Barrier through Down-Regulation of Tight Junction Proteins

    PubMed Central

    Zhang, Jinhui; Chen, Songlin; Hou, Zhiqiang; Cai, Jing; Dong, Mingmin; Shi, Xiaorui

    2015-01-01

    Middle ear infection (or inflammation) is the most common pathological condition that causes fluid to accumulate in the middle ear, disrupting cochlear homeostasis. Lipopolysaccharide, a product of bacteriolysis, activates macrophages and causes release of inflammatory cytokines. Many studies have shown that lipopolysaccharides cause functional and structural changes in the inner ear similar to that of inflammation. However, it is specifically not known how lipopolysaccharides affect the blood-labyrinth barrier in the stria vascularis (intra-strial fluid–blood barrier), nor what the underlying mechanisms are. In this study, we used a cell culture-based in vitro model and animal-based in vivo model, combined with immunohistochemistry and a vascular leakage assay, to investigate lipopolysaccharide effects on the integrity of the mouse intra-strial fluid–blood barrier. Our results show lipopolysaccharide-induced local infection significantly affects intra-strial fluid–blood barrier component cells. Pericytes and perivascular-resident macrophage-like melanocytes are particularly affected, and the morphological and functional changes in these cells are accompanied by substantial changes in barrier integrity. Significant vascular leakage is found in the lipopolysaccharide treated-animals. Consistent with the findings from the in vivo animal model, the permeability of the endothelial cell monolayer to FITC-albumin was significantly higher in the lipopolysaccharide-treated monolayer than in an untreated endothelial cell monolayer. Further study has shown the lipopolysaccharide-induced inflammation to have a major effect on the expression of tight junctions in the blood barrier. Lipopolysaccharide was also shown to cause high frequency hearing loss, corroborated by previous reports from other laboratories. Our findings show lipopolysaccharide-evoked middle ear infection disrupts inner ear fluid balance, and its particular effects on the intra-strial fluid

  2. The Methoxyflavonoid Isosakuranetin Suppresses UV-B-Induced Matrix Metalloproteinase-1 Expression and Collagen Degradation Relevant for Skin Photoaging.

    PubMed

    Jung, Hana; Lee, Eunjoo H; Lee, Tae Hoon; Cho, Man-Ho

    2016-01-01

    Solar ultraviolet (UV) radiation is a main extrinsic factor for skin aging. Chronic exposure of the skin to UV radiation causes the induction of matrix metalloproteinases (MMPs), such as MMP-1, and consequently results in alterations of the extracellular matrix (ECM) and skin photoaging. Flavonoids are considered as potent anti-photoaging agents due to their UV-absorbing and antioxidant properties and inhibitory activity against UV-mediated MMP induction. To identify anti-photoaging agents, in the present study we examined the preventative effect of methoxyflavonoids, such as sakuranetin, isosakuranetin, homoeriodictyol, genkwanin, chrysoeriol and syringetin, on UV-B-induced skin photo-damage. Of the examined methoxyflavonoids, pretreatment with isosakuranetin strongly suppressed the UV-B-mediated induction of MMP-1 in human keratinocytes in a concentration-dependent manner. Isosakuranetin inhibited UV-B-induced phosphorylation of mitogen-activated protein kinase (MAPK) signaling components, ERK1/2, JNK1/2 and p38 proteins. This result suggests that the ERK1/2 kinase pathways likely contribute to the inhibitory effects of isosakuranetin on UV-induced MMP-1 production in human keratinocytes. Isosakuranetin also prevented UV-B-induced degradation of type-1 collagen in human dermal fibroblast cells. Taken together, our findings suggest that isosakuranetin has the potential for development as a protective agent for skin photoaging through the inhibition of UV-induced MMP-1 production and collagen degradation. PMID:27598131

  3. Oxidative damage to collagen.

    PubMed

    Monboisse, J C; Borel, J P

    1992-01-01

    Extracellular matrix molecules, such as collagens, are good targets for oxygen free radicals. Collagen is the only protein susceptible to fragmentation by superoxide anion as demonstrated by the liberation of small 4-hydroxyproline-containing-peptides. It seems likely that hydroxyl radicals in the presence of oxygen cleave collagen into small peptides, and the cleavage seems to be specific to proline or 4-hydroxyproline residues. Hydroxyl radicals in the absence of oxygen or hypochlorous acid do not induce fragmentation of collagen molecules, but they trigger a polymerization of collagen through the formation of new cross-links such as dityrosine or disulfure bridges. Moreover, these cross-links can not explain the totality of high molecular weight components generated under these experimental conditions, and the nature of new cross-links induced by hydroxyl radicals or hypochlorous acid remains unclear. PMID:1333311

  4. Fabrication of Compositionally and Topographically Complex Robust Tissue Forms by 3D-Electrochemical Compaction of Collagen

    PubMed Central

    Younesi, Mousa; Islam, Anowarul; Kishore, Vipuil; Panit, Stefi; Akkus, Ozan

    2015-01-01

    Collagen solutions are phase-transformed to mechanically robust shell structures with curviplanar topographies using electrochemically induced pH gradients. The process enables rapid layer-by-layer deposition of collagen-rich mixtures over the entire field simultaneously to obtain compositionally diverse multilayered structures. In-plane tensile strength and modulus of the electrocompacted collagen sheet samples were 5200 -fold and 2300 -fold greater than that of uncompacted collagen samples. Out of plane compression tests showed 27 -fold and fold increase in compressive stress and 46 -fold increase in compressive modulus compared to uncompacted collagen sheets. Cells proliferated 4.9 times faster, and cellular area spread was 2.7 times greater on compacted collagen sheets. Electrocompaction also resulted in 2.9 times greater focal adhesion area than on regular collagen hydrogel. The reported improvements in the cell-matrix interactions with electrocompaction would serve to expedite the population of electrocompacted collagen scaffolds by cells. The capacity of the method to fabricate nonlinear curved topographies with compositional heterogeneous layers is demonstrated by sequential deposition of collagenhydroxyapatite layer over a collagen layer. The complex curved topography of the nasal structure is replicated by the electrochemical compaction method. The presented electrochemical compaction process is an enabling modality which holds significant promise for reconstruction of a wide spectrum of topographically complex systems such as joint surfaces, craniofacial defects, ears, nose or urogenital forms. PMID:26069162

  5. Autoantibodies to Type VII Collagen Mediate Fcγ-Dependent Neutrophil Activation and Induce Dermal-Epidermal Separation in Cryosections of Human Skin

    PubMed Central

    Sitaru, Cassian; Kromminga, Arno; Hashimoto, Takashi; Bröcker, Eva B.; Zillikens, Detlef

    2002-01-01

    Epidermolysis bullosa acquisita is an autoimmune subepidermal blistering disease associated with autoantibodies to type VII collagen, the major constituent of anchoring fibrils. Previous attempts to demonstrate the blister-inducing potential of autoantibodies to this protein have failed. To address this question, we used an in vitro model involving cryosections of human skin incubated with patients’ autoantibodies and leukocytes from healthy donors. We show that sera from 14 of 16 epidermolysis bullosa acquisita patients, in contrast to sera from healthy controls, induced dermal-epidermal separation in the cryosections. Recruitment and activation of neutrophils at the dermal-epidermal junction was necessary for split induction, whereas mononuclear cells were not required. Importantly, patients’ autoantibodies affinity-purified against a recombinant form of the noncollagenous 1 domain of type VII collagen retained their blister-inducing capacity in a dose-dependent manner, whereas patients’ IgG that was depleted of reactivity to type VII collagen lost this ability. Monoclonal antibody LH7.2 to the noncollagenous 1 domain of type VII collagen also induced subepidermal splits in the cryosections; F(ab′)2 fragments of autoantibodies to type VII collagen were not pathogenic. We demonstrate the capacity of autoantibodies to type VII collagen to trigger an Fcγ-dependent inflammation leading to split formation in cryosections of human skin. PMID:12107115

  6. Arginase inhibition prevents bleomycin-induced pulmonary hypertension, vascular remodeling, and collagen deposition in neonatal rat lungs.

    PubMed

    Grasemann, Hartmut; Dhaliwal, Rupinder; Ivanovska, Julijana; Kantores, Crystal; McNamara, Patrick J; Scott, Jeremy A; Belik, Jaques; Jankov, Robert P

    2015-03-15

    Arginase is an enzyme that limits substrate L-arginine bioavailability for the production of nitric oxide by the nitric oxide synthases and produces L-ornithine, which is a precursor for collagen formation and tissue remodeling. We studied the pulmonary vascular effects of arginase inhibition in an established model of repeated systemic bleomycin sulfate administration in neonatal rats that results in pulmonary hypertension and lung injury mimicking the characteristics typical of bronchopulmonary dysplasia. We report that arginase expression is increased in the lungs of bleomycin-exposed neonatal rats and that treatment with the arginase inhibitor amino-2-borono-6-hexanoic acid prevented the bleomycin-induced development of pulmonary hypertension and deposition of collagen. Arginase inhibition resulted in increased L-arginine and L-arginine bioavailability and increased pulmonary nitric oxide production. Arginase inhibition also normalized the expression of inducible nitric oxide synthase, and reduced bleomycin-induced nitrative stress while having no effect on bleomycin-induced inflammation. Our data suggest that arginase is a promising target for therapeutic interventions in neonates aimed at preventing lung vascular remodeling and pulmonary hypertension. PMID:25595650

  7. 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. PMID:26431909

  8. Rosiglitazone Prevents High Glucose-Induced Vascular Endothelial Growth Factor and Collagen IV Expression in Cultured Mesangial Cells

    PubMed Central

    Whiteside, Catharine; Wang, Hong; Xia, Ling; Munk, Snezana; Goldberg, Howard J.; Fantus, I. George

    2009-01-01

    Peroxisome proliferator-activated receptor (PPARγ), a ligand-dependent transcription factor, negatively modulates high glucose effects. We postulated that rosiglitazone (RSG), an activator of PPARγ prevents the upregulation of vascular endothelial growth factor (VEGF) and collagen IV by mesangial cells exposed to high glucose. Primary cultured rat mesangial cells were growth-arrested in 5.6 mM (NG) or 25 mM D-glucose (HG) for up to 48 hours. In HG, PPARγ mRNA and protein were reduced within 3 h, and enhanced ROS generation, expression of p22phox, VEGF and collagen IV, and PKC-ζ membrane association were prevented by RSG. In NG, inhibition of PPARγ caused ROS generation and VEGF expression that were unchanged by RSG. Reduced AMP-activated protein kinase (AMPK) phosphorylation in HG was unchanged with RSG, and VEGF expression was unaffected by AMPK inhibition. Hence, PPARγ is a negative modulator of HG-induced signaling that acts through PKC-ζ but not AMPK and regulates VEGF and collagen IV expression by mesangial cells. PMID:19609456

  9. Nanoparticulate Mineralized Collagen Scaffolds and BMP-9 Induce a Long-Term Bone Cartilage Construct in Human Mesenchymal Stem Cells.

    PubMed

    Ren, Xiaoyan; Weisgerber, Daniel W; Bischoff, David; Lewis, Michael S; Reid, Russell R; He, Tong-Chuan; Yamaguchi, Dean T; Miller, Timothy A; Harley, Brendan A C; Lee, Justine C

    2016-07-01

    Engineering the osteochondral junction requires fabrication of a microenvironment that supports both osteogenesis and chondrogenesis. Multiphasic scaffold strategies utilizing a combination of soluble factors and extracellular matrix components are ideally suited for such applications. In this work, the contribution of an osteogenic nanoparticulate mineralized glycosaminoglycan scaffold (MC-GAG) and a dually chondrogenic and osteogenic growth factor, BMP-9, in the differentiation of primary human mesenchymal stem cells (hMSCs) is evaluated. Although 2D cultures demonstrate alkaline phosphatase activity and mineralization of hMSCs induced by BMP-9, MC-GAG scaffolds do not demonstrate significant differences in the collagen I expression, osteopontin expression, or mineralization. Instead, BMP-9 increases expression of collagen II, Sox9, aggrecan (ACAN), and cartilage oligomeric protein. However, the hypertrophic chondrocyte marker, collagen X, is not elevated with BMP-9 treatment. In addition, histologic analyses demonstrate that while BMP-9 does not increase mineralization, BMP-9 treatment results in an increase of sulfated glycosaminoglycans. Thus, the combination of BMP-9 and MC-GAG stimulates chondrocytic and osteogenic differentiation of hMSCs. PMID:27275929

  10. Ear defects.

    PubMed

    Shonka, David C; Park, Stephen S

    2009-08-01

    The projection and exposure of the auricle make it particularly susceptible to actinic injury and thus to cutaneous malignancies. Auricular reconstruction is challenging because of its unique surface anatomy and undulating topography. This article organizes auricular defects into different categories based on anatomic location and extent of tissue loss, including skin-only defects, small composite defects, full-thickness defects involving or sparing the upper third of the ear, and total auricular loss. The authors share an algorithm for repair of the array of auricular defects. PMID:19698921

  11. Increased Inner Ear Susceptibility to Noise Injury in Mice With Streptozotocin-Induced Diabetes

    PubMed Central

    Fujita, Takeshi; Yamashita, Daisuke; Katsunuma, Sayaka; Hasegawa, Shingo; Tanimoto, Hitoshi; Nibu, Ken-ichi

    2012-01-01

    We aimed to investigate the pathophysiology of diabetes-associated hearing impairment in type 1 diabetes using mice with streptozotocin-induced diabetes (C57BL/6J; male). Hearing function was evaluated 1, 3, and 5 months after induction of diabetes (five diabetic and five control animals per time point) using auditory-evoked brain stem responses (ABRs). Mice (four diabetic and four control) were exposed to loud noise (105 dB) 5 months after induction of diabetes. ABRs were measured before and after noise exposure. Cochlear blood flows were measured by laser-Doppler flowmeter. Spiral ganglion cells (SGCs) were counted. Vessel endothelial cells were observed by CD31 immunostaining. Chronologic changes in the ABR threshold shift were not significantly different between the diabetic and control groups. However, vessel walls in the modiolus of the cochleae were significantly thicker in the diabetic group than the control group. Additionally, recovery from noise-induced injury was significantly impaired in diabetic mice. Reduced cochlea blood flows and SGC loss were observed in diabetic mice cochleae after noise exposure. Our data suggest that diabetic cochleae are more susceptible than controls to loud noise exposure, and decreased cochlear blood flow due to sclerosis of the vessels and consequent loss of SGCs are possible mechanisms of hearing impairment in diabetic patients. PMID:22851574

  12. pH-responsive collagen fibrillogenesis in confined droplets induced by vapour diffusion.

    PubMed

    Ramírez-Rodríguez, Gloria Belén; Iafisco, Michele; Tampieri, Anna; Gómez-Morales, Jaime; Delgado-López, José Manuel

    2014-10-01

    A novel methodology for the assembly of collagen fibrils in microliter drops is proposed. It consists in the gradual increase of pH by means of vapour diffusion coming from the decomposition of NH4HCO3 solutions. The pH increase rate as well as the final steady pH of solutions containing collagen can be adjusted by varying the concentration of NH4HCO3. Both parameters are of predominant importance in collagen fibrillogenesis. The effect of these parameters on the kinetic of the fibrillogenesis process and on the fibrils morphology was studied. We found that both the kinetic and the morphology are mainly driven by electrostatic interactions. A gradual increase of pH slows down the formation of collagen fibres and favours the lateral interaction between fibrils producing broader fibres. On the other hand, a rapid increase of pH reduces the lateral electrostatic interactions favouring the formation of thinner fibres. The formation of the D-band periodicity is also a pH-dependent process that occurs after fibrillogenesis when the most stable state of fibres formation has been reached. PMID:24652593

  13. Statins accelerate the onset of collagen type II-induced arthritis in mice

    PubMed Central

    2012-01-01

    Introduction Statins (hydroxymethylglutaryl coenzyme A reductase inhibitors) are effective in reducing the risk of cardiovascular morbidity and mortality in patients with hyperlipidemia, hypertension, or type II diabetes. Next to their cholesterol-lowering activity, statins have immunomodulatory properties. Based on these properties, we hypothesized that statin use may eventually lead to dysregulation of immune responses, possibly resulting in autoimmunity. We have recently shown in an observational study that statin use was associated with an increased risk of developing rheumatoid arthritis. Our objective was to investigate whether a causal relationship could be established for this finding. Methods The mouse collagen type II (CII)-induced arthritis (CIA) model was used, with immunization, challenge, and euthanasia at days 0, 21, and 42, respectively. Statins were given orally before (day -28 until day 21) or after (day 21 until day 42) CIA induction. Atorvastatin (0.2 mg/day) or pravastatin (0.8 mg/day) was administered. Arthritis was recorded three times a week. Serum anti-CII autoantibodies and cytokines in supernatants from Concanavalin-A-stimulated lymph node cells and CII-stimulated spleen cells were measured. Results Statin administration accelerated arthritis onset and resulted in 100% arthritic animals, whereas only seven out of 12 nonstatin control animals developed arthritis. Atorvastatin administration after CIA induction resulted in earlier onset than atorvastatin administration before induction, or than pravastatin administration before or after induction. The arthritic score of animals given pravastatin before CIA induction was similar to that of the nonstatin controls, whereas the other groups that received statins showed higher arthritic scores. Atorvastatin administration, especially before CIA induction, increased anti-CII autoantibody production. IL-2 and IL-17 production by lymph node and spleen cells was higher in CIA animals than in PBS

  14. Aronia melanocarpa Concentrate Ameliorates Pro-Inflammatory Responses in HaCaT Keratinocytes and 12-O-Tetradecanoylphorbol-13-Acetate-Induced Ear Edema in Mice.

    PubMed

    Goh, Ah Ra; Youn, Gi Soo; Yoo, Ki-Yeon; Won, Moo Ho; Han, Sang-Zin; Lim, Soon Sung; Lee, Keun Wook; Choi, Soo Young; Park, Jinseu

    2016-07-01

    Abnormal expression of pro-inflammatory mediators such as cell adhesion molecules and cytokines has been implicated in various inflammatory skin diseases, including atopic dermatitis. In this study, we investigated the anti-inflammatory activity of Aronia melanocarpa concentrate (AC) and its action mechanisms using in vivo and in vitro skin inflammation models. Topical application of AC on mouse ears significantly suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema formation, as judged by measuring ear thickness and weight, and histological analysis. Topical administration of AC also reduced the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 in TPA-stimulated mouse ears. Pretreatment with AC suppressed TNF-α-induced ICAM-I expression and subsequent monocyte adhesiveness in human keratinocyte cell line HaCaT. In addition, AC significantly decreased intracellular reactive oxygen species (ROS) generation as well as mitogen-activated protein kinase (MAPK) activation in TNF-α-stimulated HaCaT cells. AC and its constituent cyanidin 3-glucoside also attenuated TNF-α-induced IKK activation, IκB degradation, p65 phosphorylation/nuclear translocation, and p65 DNA binding activity in HaCaT cells. Overall, our results indicate that AC exerts anti-inflammatory activities by inhibiting expression of pro-inflammatory mediators in vitro and in vivo possibly through suppression of ROS-MAPK-NF-κB signaling pathways. Therefore, AC may be developed as a therapeutic agent to treat various inflammatory skin diseases. PMID:27331630

  15. Induction of PNAd and N-acetylglucosamine 6-O-sulfotransferases 1 and 2 in mouse collagen-induced arthritis

    PubMed Central

    Yang, Jiwei; Rosen, Steven D; Bendele, Philip; Hemmerich, Stefan

    2006-01-01

    Background Leukocyte recruitment across blood vessels is fundamental to immune surveillance and inflammation. Lymphocyte homing to peripheral lymph nodes is mediated by the adhesion molecule, L-selectin, which binds to sulfated carbohydrate ligands on high endothelial venules (HEV). These glycoprotein ligands are collectively known as peripheral node addressin (PNAd), as defined by the function-blocking monoclonal antibody known as MECA-79. The sulfation of these ligands depends on the action of two HEV-expressed N-acetylglucosamine 6-O-sulfotransferases: GlcNAc6ST-2 and to a lesser degree GlcNAc6ST-1. Induction of PNAd has also been shown to occur in a number of human inflammatory diseases including rheumatoid arthritis (RA). Results In order to identify an animal model suitable for investigating the role of PNAd in chronic inflammation, we examined the expression of PNAd as well as GlcNAc6ST-1 and -2 in collagen-induced arthritis in mice. Here we show that PNAd is expressed in the vasculature of arthritic synovium in mice immunized with collagen but not in the normal synovium of control animals. This de novo expression of PNAd correlates strongly with induction of transcripts for both GlcNAc6ST-1 and GlcNAc6ST-2, as well as the expression of GlcNAc6ST-2 protein. Conclusion Our results demonstrate that PNAd and the sulfotransferases GlcNAc6ST-1 and 2 are induced in mouse collagen-induced arthritis and suggest that PNAd antagonists or inhibitors of the enzymes may have therapeutic benefit in this widely-used mouse model of RA. PMID:16772045

  16. Flow-Induced Crystallization of Collagen: A Potentially Critical Mechanism in Early Tissue Formation.

    PubMed

    Paten, Jeffrey A; Siadat, Seyed Mohammad; Susilo, Monica E; Ismail, Ebraheim N; Stoner, Jayson L; Rothstein, Jonathan P; Ruberti, Jeffrey W

    2016-05-24

    The type I collagen monomer is one of nature's most exquisite and prevalent structural tools. Its 300 nm triple-helical motifs assemble into tough extracellular fibers that transition seamlessly across tissue boundaries and exceed cell dimensions by up to 4 orders of magnitude. In spite of extensive investigation, no existing model satisfactorily explains how such continuous structures are generated and grown precisely where they are needed (aligned in the path of force) by discrete, microscale cells using materials with nanoscale dimensions. We present a simple fiber drawing experiment, which demonstrates that slightly concentrated type I collagen monomers can be "flow-crystallized" to form highly oriented, continuous, hierarchical fibers at cell-achievable strain rates (<1 s(-1)) and physiologically relevant concentrations (∼50 μM). We also show that application of tension following the drawing process maintains the structural integrity of the fibers. While mechanical tension has been shown to be a critical factor driving collagen fibril formation during tissue morphogenesis in developing animals, the precise role of force in the process of building tissue is not well understood. Our data directly couple mechanical tension, specifically the extensional strain rate, to collagen fibril assembly. We further derive a "growth equation" which predicts that application of extensional strains, either globally by developing muscles or locally by fibroblasts, can rapidly drive the fusion of already formed short fibrils to produce long-range, continuous fibers. The results provide a pathway to scalable connective tissue manufacturing and support a mechano-biological model of collagen fibril deposition and growth in vivo. PMID:27070851

  17. COLLAGEN PROCESSING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collagen dispersions, produced from fibrils recovered from milled bovine collagen, have shown promise in environmental remediation in applications as settling aids, filtration aids, fractionation media, oil drop stabilizers, and water purification aids. Macroporous structures, processed by controll...

  18. Epidermal growth factor (EGF) antagonizes transforming growth factor (TGF)-beta1-induced collagen lattice contraction by human skin fibroblasts.

    PubMed

    Park, J S; Kim, J Y; Cho, J Y; Kang, J S; Yu, Y H

    2000-12-01

    Wound contraction plays an important role in healing, but in extreme conditions, it may lead to excessive scar formation and pathological wound contracture. To date, the key regulator of excessive contracture is known to be transforming growth factor-beta (TGF-beta1). In this study, we have evaluated epidermal growth factor (EGF) antagonism in fibroblast-populated collagen lattice (FPCL) gel contraction, which has been generally used as an in vitro model thought to mimic wound contraction in vivo. As expected, TGF-beta1 treatment enhanced normal fibroblast-induced collagen gel contraction in a dose-dependent manner. In contrast, EGF did not affect normal gel formation, but significantly antagonized TGF-beta1-induced gel formation (p<0.05 at 100 ng/ml), whereas the other growth factor, platelet-derived growth factor (PDGF), did not altered either normal or TGF-beta1-induced gel contractions. Similarly, EGF treatment, but not PDGF, also significantly suppressed TGF-beta1 release that was autologously elicited by TGF-beta1 treatment (p<0.01 at 100 ng/ml). Therefore, the results suggest that EGF may negatively regulate the role of TGF-beta1 through attenuating autologous release of TGF-beta1. PMID:11145189

  19. Mechanical investigations of sound-induced responses in a simple ear

    NASA Astrophysics Data System (ADS)

    Nowotny, Manuela; Hummel, Jennifer; Kössl, Manfred; Udayashankar, Arun Palghat; Wolf, Konstantin

    2015-12-01

    Previous in-vivo studies have shown that the tonotopically-organized hearing organ, the crista acustica, of the bushcricket Mecopoda elongata is a promising model for investigations of basic hearing mechanics. This linearly arranged organ with a length of <1 mm consists of about 45 receptor units and processes frequencies from about 4 up to at least 80 kHz. Pure-tone stimulation of the crista acustica leads to travelling waves along the longitudinal axis of the hearing organ. We found that the amplitude maximum of the sound-induced travelling waves is shifted in the radial direction during the propagation of the travelling wave. The overall amplitude maximum was found to be located always on one side (anterior) in respect to the transduction place. This mechanical biasing presumably optimizes the signal transduction. Additionally, the amplitude response maximum of the travelling wave during one cycle of motion exhibits different degrees in the radial shift. During broad-band noise stimulation, the mechanical response of the crista acustica exhibits a low-frequency dominance. When using the conspecific chirp of M. elongata (2-90 kHz), as stimulus frequencies above 30 kHz do not lead to large responses even though the hearing organ is able to detect frequencies up to at least 80 kHz, covering the frequency range of the chirp with its amplitude maximum at about 70 kHz.

  20. Ears and Altitude

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ears and Altitude Ears and Altitude Patient Health Information ... uncomfortable feeling of fullness or pressure. Why do ears pop? Normally, swallowing causes a little click or ...

  1. Ear tube insertion

    MedlinePlus

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  2. Ear tube insertion - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100045.htm Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Update Date 8/ ...

  3. Delphinidin prevents high glucose-induced cell proliferation and collagen synthesis by inhibition of NOX-1 and mitochondrial superoxide in mesangial cells.

    PubMed

    Song, Seung Eun; Jo, Hye Jun; Kim, Yong-Woon; Cho, Young-Je; Kim, Jae-Ryong; Park, So-Young

    2016-04-01

    This study examined the effect of delphinidin on high glucose-induced cell proliferation and collagen synthesis in mesangial cells. Glucose dose-dependently (5.6-25 mM) increased cell proliferation and collagen I and IV mRNA levels, whereas pretreatment with delphinidin (50 μM) prevented cell proliferation and the increased collagen mRNA levels induced by high glucose (25 mM). High glucose increased reactive oxygen species (ROS) generation, and this was suppressed by pretreating delphinidin or the antioxidant N-acetyl cysteine. NADPH oxidase (NOX) 1 was upregulated by high glucose, but pretreatment with delphinidin abrogated this upregulation. Increased mitochondrial superoxide by 25 mM glucose was also suppressed by delphinidin. The NOX inhibitor apocynin and mitochondria-targeted antioxidant Mito TEMPO inhibited ROS generation and cell proliferation induced by high glucose. Phosphorylation of extracellular signal regulated kinase (ERK)1/2 was increased by high glucose, which was suppressed by delphinidin, apocynin or Mito TEMPO. Furthermore, PD98059 (an ERK1/2 inhibitor) prevented the high glucose-induced cell proliferation and increased collagen mRNA levels. Transforming growth factor (TGF)-β protein levels were elevated by high glucose, and pretreatment with delphinidin or PD98059 prevented this augmentation. These results suggest that delphinidin prevents high glucose-induced cell proliferation and collagen synthesis by inhibition of NOX-1 and mitochondrial superoxide in mesangial cells. PMID:27103328

  4. Bleomycin-induced pulmonary fibrosis in hamsters. An alveolar macrophage product increases fibroblast prostaglandin E2 and cyclic adenosine monophosphate and suppresses fibroblast proliferation and collagen production.

    PubMed Central

    Clark, J G; Kostal, K M; Marino, B A

    1983-01-01

    Bleomycin-induced pulmonary fibrosis in hamsters is associated with collagen accumulation that results from increased lung collagen synthesis rates. However, 1-2 wk after intratracheal instillation of bleomycin, lung collagen synthesis rates decline toward control values. To evaluate the potential role of the bronchoalveolar macrophage in regulating lung collagen production, we studied the effects of macrophages from normal and bleomycin-treated hamsters upon fibroblasts in vitro. We observed: (a) Medium from macrophage cultures decreased fibroblast [3H]thymidine incorporation and nondialyzable [3H]hydroxyproline production in a dose-dependent manner. Fibroblast cell counts were decreased in exposed cultures, and fibroblast viability was unchanged. Procollagen prolyl hydroxylation and prolyl-transfer RNA-specific activity were not altered by macrophage medium; this indicates that [3H]hydroxyproline reflects collagen production rate under the experimental conditions. (b) The suppressive effect of macrophage medium was selective for collagen since collagen production decreased more than noncollagen protein production. (c) Medium from bleomycin-treated hamster macrophages suppressed fibroblast proliferation and collagen production to a greater degree than medium from normal hamster macrophages. (d) Fibroblast suppression by macrophage medium was associated with increased fibroblast endogenous prostaglandin E2 production and intracellular cyclic AMP (cAMP). (e) Incubation of fibroblasts with indomethacin before exposure completely inhibited prostaglandin E2 production and increases in cAMP, and eliminated suppression of fibroblast proliferation and collagen production. The macrophage-derived suppressive factor has an apparent molecular weight of 20,000-30,000 and is heat stable. It does not appear to be species restricted since both hamster and human lung fibroblasts are similarly suppressed. It is at least in part preformed in macrophages obtained by lavage, but its

  5. Shikonin reduces TGF-β1-induced collagen production and contraction in hypertrophic scar-derived human skin fibroblasts.

    PubMed

    Fan, Chen; Dong, Ying; Xie, Yan; Su, Yonghua; Zhang, Xufang; Leavesley, David; Upton, Zee

    2015-10-01

    Hypertrophic scarring/hypertrophic scars (HS) is a highly prevalent condition following burns and trauma wounds. Numerous studies have demonstrated that transforming growth factor-β1 (TGF‑β1) plays an essential role in the wound healing process by regulating cell differentiation, collagen production and extracellular matrix degradation. The increased expression of TGF-β1 is believed to result in the formation of HS. Shikonin (SHI), an active component extracted from the Chinese herb, Radix Arnebiae, has previously been found to downregulate the expression of TGF-β1 in keratinocyte/fibroblast co-culture conditioned medium. In view of this, in this study, we aimed to further investigate the effects of SHI on TGF-β1-stimulated hypertrophic scar-derived human skin fibroblasts (HSFs) and examined the underlying mechanisms. Cell viability and proliferation were measured using alamarBlue and CyQUANT assays. The total amount of collagen and cell contraction were examined using Sirius red staining and the cell contraction assay kit. Gene expression and signalling pathway activation were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis. Our results revealed that SHI reduced TGF-β1‑induced collagen production through the ERK/Smad signalling pathway and attenuated TGF-β1‑induced cell contraction by downregulating α-smooth muscle actin (αSMA) expression in the HSFs. The data from this study provide evidence supporting the potential use of SHI as a novel treatment for HS. PMID:26239419

  6. Treatment for chemotherapy-induced alopecia in mice using parathyroid hormone agonists and antagonists linked to a collagen binding domain

    PubMed Central

    Katikaneni, Ranjitha; Ponnapakkam, Tulasi; Suda, Hirofumi; Miyata, Shigeru; Sakon, Joshua; Matsushita, Osamu; Gensure, Robert C.

    2013-01-01

    Parathyroid hormone (PTH) agonists and antagonists have been shown to improve hair growth after chemotherapy; however, rapid clearance and systemic side-effects complicate their usage. To facilitate delivery and retention to skin, we fused PTH agonists and antagonists to the collagen binding domain (CBD) of Clostridium histolyticum collagenase. in-vitro studies showed that the agonist fusion protein, PTH-CBD, bound collagen and activated the PTH/parathyroid hormone-related peptide receptor in SaOS-2 cells. The antagonist fusion proteins, PTH(7–33)-CBD and PTH([−1]–33)-CBD, also bound collagen and antagonized PTH(1–34) effect in SaOS-2 cells; however, PTH(7–33)-CBD had lower intrinsic activity. Distribution studies confirmed uptake of PTH-CBD to the skin at 1 and 12 hr after subcutaneous injection. We assessed in vivo efficacy of PTH-CBD and PTH(7–33)-CBD in C57BL/6J mice. Animals were depilated to synchronize the hair follicles; treated on Day 7 with agonist, antagonist, or vehicle; treated on Day 9 with cyclophosphamide (150 mg/kg i.p.) or vehicle; and sacrificed on Day 39. Normal mice (no chemo and no treatment) showed rapid regrowth of hair and normal histology. Chemo + Vehicle mice showed reduced hair regrowth and decreased pigmentation; histology revealed reduced number and dystrophic anagen/catagen follicles. Chemo + Antagonist mice were grossly and histologically indistinguishable from Chemo + Vehicle mice. Chemo + Agonist mice showed more rapid regrowth and repigmentation of hair; histologically, there was a normal number of hair follicles, most of which were in the anagen phase. Overall, the agonist PTH-CBD had prominent effects in reducing chemotherapy-induced damage of hair follicles and may show promise as a therapy for chemotherapy-induced alopecia. PMID:22130912

  7. IL-10-producing regulatory B10 cells ameliorate collagen-induced arthritis via suppressing Th17 cell generation.

    PubMed

    Yang, Min; Deng, Jun; Liu, Yang; Ko, King-Hung; Wang, Xiaohui; Jiao, Zhijun; Wang, Shengjun; Hua, Zichun; Sun, Lingyun; Srivastava, Gopesh; Lau, Chak-Sing; Cao, Xuetao; Lu, Liwei

    2012-06-01

    IL-10-producing CD1d(hi)CD5(+) B cells, also known as B10 cells, have been shown to possess a regulatory function in the inhibition of immune responses, but whether and how B10 cells suppress the development of autoimmune arthritis remain largely unclear. In this study, we detected significantly decreased numbers of IL-10-producing B cells, but increased IL-17-producing CD4(+) T (Th17) cells in both spleen and draining lymph nodes of mice during the acute stage of collagen-induced arthritis (CIA) when compared with adjuvant-treated control mice. On adoptive transfer of in vitro expanded B10 cells, collagen-immunized mice showed a marked delay of arthritis onset with reduced severity of both clinical symptoms and joint damage, accompanied by a substantial reduction in the number of Th17 cells. To determine whether B10 cells directly inhibit the generation of Th17 cells in culture, naive CD4(+) T cells labeled with carboxyfluorescein succinimidyl ester (CFSE) were co-cultured with B10 cells. These B10 cells suppressed Th17 cell differentiation via the reduction of STAT3 phosphorylation and retinoid-related orphan receptor γt (RORγt) expression. Moreover, Th17 cells showed significantly decreased proliferation when co-cultured with B10 cells. Although adoptive transfer of Th17 cells triggered the development of collagen-induced arthritis in IL-17(-/-)DBA/1J mice, co-transfer of B10 cells with Th17 cells profoundly delayed the onset of arthritis. Thus, our findings suggest a novel regulatory role of B10 cells in arthritic progression via the suppression of Th17 cell generation. PMID:22538089

  8. Anti-angiogenic therapy increases intratumoral adenovirus distribution by inducing collagen degradation

    PubMed Central

    Thaci, Bart; Ulasov, Ilya V.; Ahmed, Atique U.; Ferguson, Sherise D.; Han, Yu; Lesniak, Maciej S.

    2012-01-01

    Conditionally replicating adenoviruses (CRAd) are a promising class of gene therapy agents that can overcome already known glioblastoma (GBM) resistance mechanisms but have limited distribution upon direct intratumoral (i.t.) injection. Collagen bundles in the extracellular matrix (ECM) play an important role in inhibiting virus distribution. In fact, ECM pre-treatment with collagenases improves virus distributions to tumor cells. Matrix metalloproteinases (MMPs) are an endogenous class of collagenases secreted by tumor cells whose function can be altered by different drugs including anti-angiogenic agents, such as bevacizumab. In this study we hypothesized that up-regulation of MMP activity during antiangiogenic therapy can improve CRAd-S-pk7 distribution in GBM. We find that MMP-2 activity in human U251 GBM xenografts increases (*p=0.03) and collagen IV content decreases (*p=0.01) during vascular endothelial growth factor (VEGF-A) antibody neutralization. After proving that collagen IV inhibits CRAd-S-pk7 distribution in U251 xenografts (Spearman rho= −0.38; **p=0.003), we show that VEGF blocking antibody treatment followed by CRAd-S-pk7 i.t. injection reduces U251 tumor growth more than each individual agent alone (***p<0.0001). Our data proposes a novel approach to improve virus distribution in tumors by relying on the early effects of anti-angiogenic therapy. PMID:22673390

  9. Anti-angiogenic therapy increases intratumoral adenovirus distribution by inducing collagen degradation.

    PubMed

    Thaci, B; Ulasov, I V; Ahmed, A U; Ferguson, S D; Han, Y; Lesniak, M S

    2013-03-01

    Conditionally replicating adenoviruses (CRAd) are a promising class of gene therapy agents that can overcome already known glioblastoma (GBM) resistance mechanisms but have limited distribution upon direct intratumoral (i.t.) injection. Collagen bundles in the extracellular matrix (ECM) have an important role in inhibiting virus distribution. In fact, ECM pre-treatment with collagenases improves virus distributions to tumor cells. Matrix metalloproteinases (MMPs) are an endogenous class of collagenases secreted by tumor cells whose function can be altered by different drugs including anti-angiogenic agents, such as bevacizumab. In this study we hypothesized that upregulation of MMP activity during anti-angiogenic therapy can improve CRAd-S-pk7 distribution in GBM. We find that MMP-2 activity in human U251 GBM xenografts increases (*P=0.03) and collagen IV content decreases (*P=0.01) during vascular endothelial growth factor (VEGF-A) antibody neutralization. After proving that collagen IV inhibits CRAd-S-pk7 distribution in U251 xenografts (Spearman rho=-0.38; **P=0.003), we show that VEGF-blocking antibody treatment followed by CRAd-S-pk7 i.t. injection reduces U251 tumor growth more than each individual agent alone (***P<0.0001). Our data propose a novel approach to improve virus distribution in tumors by relying on the early effects of anti-angiogenic therapy. PMID:22673390

  10. Platelet receptor interplay regulates collagen-induced thrombus formation in flowing human blood.

    PubMed

    Siljander, Pia R-M; Munnix, Imke C A; Smethurst, Peter A; Deckmyn, Hans; Lindhout, Theo; Ouwehand, Willem H; Farndale, Richard W; Heemskerk, Johan W M

    2004-02-15

    The platelet glycoproteins (GPs) Ib, integrin alpha(2)beta(1), and GPVI are considered central to thrombus formation. Recently, their relative importance has been re-evaluated based on data from murine knockout models. To examine their relationship during human thrombus formation on collagen type I fibers at high shear (1000 s(-1)), we tested a novel antibody against GPVI, an immunoglobulin single-chain variable fragment, 10B12, together with specific antagonists for GPIb alpha (12G1 Fab(2)) and alpha(2)beta(1) (6F1 mAb or GFOGER-GPP peptide). GPVI was found to be crucial for aggregate formation, Ca(2+) signaling, and phosphatidylserine (PS) exposure, but not for primary adhesion, even with more than 97% receptor blockade. Inhibiting alpha(2)beta(1) revealed its involvement in regulating Ca(2+) signaling, PS exposure, and aggregate size. Both GPIb alpha and alpha(2)beta(1) contributed to primary adhesion, showing overlapping function. The coinhibition of receptors revealed synergism in thrombus formation: the coinhibition of adenosine diphosphate (ADP) receptors with collagen receptors further decreased adhesion and aggregation, and, crucially, the complete eradication of thrombus formation required the coinhibition of GPVI with either GPIb alpha or alpha(2)beta(1). In summary, human platelet deposition on collagen depends on the concerted interplay of several receptors: GPIb in synergy with alpha(2)beta(1) mediating primary adhesion, reinforced by activation through GPVI, which further regulates the thrombus formation. PMID:14563646