Kinetic Super-Resolution Long-Wave Infrared (KSR LWIR) Thermography Diagnostic for Building Envelopes: Camp Lejeune, NC

DTIC Science & Technology

2015-08-18

of Defense (DoD) to achieve cost-effective energy efficiency at much greater scale than other commercially available techniques of measuring energy...recommends specific energy conservation measures (ECMs), and quantifies significant potential return on investment. ERDC/CERL TR-15-18 iii...effective energy efficiency at much greater scale than other commercially available techniques of measuring energy loss due to envelope inefficien- cies

Kinetic Super-Resolution Long-Wave Infrared (KSR LWIR) Thermography Diagnostic for Building Envelopes: Scott AFB, IL

DTIC Science & Technology

2015-08-18

techniques of measuring energy loss due to enve- lope inefficiencies from the built environment. A multi-sensor hardware device attached to the roof of a...at this installa- tion, recommends specific energy conservation measures (ECMs), and quantifies significant potential return on investment. ERDC/CERL...to several thousand square feet, total building square feet was used as a metric to measure the cost effectiveness of handheld versus mobile

Effectiveness of energy conservation management on fatigue and participation in multiple sclerosis: A randomized controlled trial.

PubMed

Blikman, Lyan Jm; van Meeteren, Jetty; Twisk, Jos Wr; de Laat, Fred Aj; de Groot, Vincent; Beckerman, Heleen; Stam, Henk J; Bussmann, Johannes Bj

2017-10-01

Fatigue is a frequently reported and disabling symptom in multiple sclerosis (MS). To investigate the effectiveness of an individual energy conservation management (ECM) intervention on fatigue and participation in persons with primary MS-related fatigue. A total of 86 severely fatigued and ambulatory adults with a definite diagnosis of MS were randomized in a single-blind, two-parallel-arm randomized clinical trial to the ECM group or the information-only control group in outpatient rehabilitation departments. Blinded assessments were carried out at baseline and at 8, 16, 26 and 52 weeks after randomization. Primary outcomes were fatigue (fatigue subscale of Checklist Individual Strength - CIS20r) and participation (Impact on Participation and Autonomy scale - IPA). Modified intention-to-treat analysis was based on 76 randomized patients (ECM, n = 36; MS nurse, n=40). No significant ECM effects were found for fatigue (overall difference CIS20r between the groups = -0.81; 95% confidence interval (CI), -3.71 to 2.11) or for four out of five IPA domains. An overall unfavourable effect was found in the ECM group for the IPA domain social relations (difference between the groups = 0.19; 95% CI, 0.03 to 0.35). The individual ECM format used in this study did not reduce MS-related fatigue and restrictions in participation more than an information-only control condition.

Institutional Transformation 2.5 Building Module Help Manual.

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

Villa, Daniel

The Institutional Transformation (IX) building module is a software tool developed at Sandia National Laboratories to evaluate energy conservation measures (ECMs) on hundreds of DOE-2 building energy models simultaneously. In IX, ECMs can be designed through parameterizing DOE-2 building models and doing further processing via visual basic for applications subroutines. IX provides the functionality to handle multiple building models for different years, which enables incrementally changing a site of hundreds of buildings over time. It also enables evaluation of the effects of changing climate, comparisons between data and modeling results, and energy use of centralized utility buildings (CUBs). IX consistsmore » of a Microsoft Excel(r) user interface, Microsoft Access(r) database, and Microsoft Excel(r) CUB build utility whose functionalities are described in detail in this report. In addition to descriptions of the user interfaces, descriptions of every ECM already designed in IX is included. SAND2016-8983 IX 2.5 Help Manual« less

Biological and mechanical interplay at the Macro- and Microscales Modulates the Cell-Niche Fate.

PubMed

Sarig, Udi; Sarig, Hadar; Gora, Aleksander; Krishnamoorthi, Muthu Kumar; Au-Yeung, Gigi Chi Ting; de-Berardinis, Elio; Chaw, Su Yin; Mhaisalkar, Priyadarshini; Bogireddi, Hanumakumar; Ramakrishna, Seeram; Boey, Freddy Yin Chiang; Venkatraman, Subbu S; Machluf, Marcelle

2018-03-02

Tissue development, regeneration, or de-novo tissue engineering in-vitro, are based on reciprocal cell-niche interactions. Early tissue formation mechanisms, however, remain largely unknown given complex in-vivo multifactoriality, and limited tools to effectively characterize and correlate specific micro-scaled bio-mechanical interplay. We developed a unique model system, based on decellularized porcine cardiac extracellular matrices (pcECMs)-as representative natural soft-tissue biomaterial-to study a spectrum of common cell-niche interactions. Model monocultures and 1:1 co-cultures on the pcECM of human umbilical vein endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) were mechano-biologically characterized using macro- (Instron), and micro- (AFM) mechanical testing, histology, SEM and molecular biology aspects using RT-PCR arrays. The obtained data was analyzed using developed statistics, principal component and gene-set analyses tools. Our results indicated biomechanical cell-type dependency, bi-modal elasticity distributions at the micron cell-ECM interaction level, and corresponding differing gene expression profiles. We further show that hMSCs remodel the ECM, HUVECs enable ECM tissue-specific recognition, and their co-cultures synergistically contribute to tissue integration-mimicking conserved developmental pathways. We also suggest novel quantifiable measures as indicators of tissue assembly and integration. This work may benefit basic and translational research in materials science, developmental biology, tissue engineering, regenerative medicine and cancer biomechanics.

Drosophila Perlecan Regulates Intestinal Stem Cell Activity via Cell-Matrix Attachment

PubMed Central

You, Jia; Zhang, Yan; Li, Zhouhua; Lou, Zhefeng; Jin, Longjin; Lin, Xinhua

2014-01-01

Summary Stem cells require specialized local microenvironments, termed niches, for normal retention, proliferation, and multipotency. Niches are composed of cells together with their associated extracellular matrix (ECM). Currently, the roles of ECM in regulating niche functions are poorly understood. Here, we demonstrate that Perlecan (Pcan), a highly conserved ECM component, controls intestinal stem cell (ISC) activities and ISC-ECM attachment in Drosophila adult posterior midgut. Loss of Pcan from ISCs, but not other surrounding cells, causes ISCs to detach from underlying ECM, lose their identity, and fail to proliferate. These defects are not a result of a loss of epidermal growth factor receptor (EGFR) or Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling activity but partially depend on integrin signaling activity. We propose that Pcan secreted by ISCs confers niche properties to the adjacent ECM that is required for ISC maintenance of stem cell identity, activity, and anchorage to the niche. PMID:24936464

[Soil propagule bank of ectomycorrhizal fungi in natural forest of Pinus bungeana].

PubMed

Zhao, Nan Xing; Han, Qi Sheng; Huang, Jian

2017-12-01

To conserve and restore the forest of Pinu bungeana, we investigated the soil propagule bank of ectomycorrhizal (ECM) fungi in a severely disturbed natural forest of P. bungeana in Shaanxi Province, China. We used a seedling-bioassay method to bait the ECM fungal propagules in the soils collected from the forest site. ECM was identified by combining morph typing with ITS-PCR-sequencing. We obtained 73 unique sequences from the ECM associated with P. bungeana seedlings, and assigned them into 12 ECM fungal OTUs at the threshold of 97% based on the sequence similarity. Rarefaction curve displayed almost all ECM fungi in the propagule bank were detected. The most frequent OTU (80%) showed poor similarity (75%) with existing sequences in the online database, which suggested it might be a new species. Cenococcum geophilum, Tomentella sp., Tuber sp. were common species in the propagule bank. Although C. geophilum and Tomentella sp. were frequently detected in other soil propagule banks of pine forest, the most frequent OTU was not assigned to known genus or family, which indicated the host-specif of ECM propagule banks associa-ted with P. bungeana. This result confirmed the importance of the special ECM propagule banks associated with P. bungeana for natural forest restoration.

Genetic Background is a Key Determinant of Glomerular Extracellular Matrix Composition and Organization

PubMed Central

Randles, Michael J.; Woolf, Adrian S.; Huang, Jennifer L.; Byron, Adam; Humphries, Jonathan D.; Price, Karen L.; Kolatsi-Joannou, Maria; Collinson, Sophie; Denny, Thomas; Knight, David; Mironov, Aleksandr; Starborg, Toby; Korstanje, Ron; Humphries, Martin J.; Long, David A.

2015-01-01

Glomerular disease often features altered histologic patterns of extracellular matrix (ECM). Despite this, the potential complexities of the glomerular ECM in both health and disease are poorly understood. To explore whether genetic background and sex determine glomerular ECM composition, we investigated two mouse strains, FVB and B6, using RNA microarrays of isolated glomeruli combined with proteomic glomerular ECM analyses. These studies, undertaken in healthy young adult animals, revealed unique strain- and sex-dependent glomerular ECM signatures, which correlated with variations in levels of albuminuria and known predisposition to progressive nephropathy. Among the variation, we observed changes in netrin 4, fibroblast growth factor 2, tenascin C, collagen 1, meprin 1-α, and meprin 1-β. Differences in protein abundance were validated by quantitative immunohistochemistry and Western blot analysis, and the collective differences were not explained by mutations in known ECM or glomerular disease genes. Within the distinct signatures, we discovered a core set of structural ECM proteins that form multiple protein–protein interactions and are conserved from mouse to man. Furthermore, we found striking ultrastructural changes in glomerular basement membranes in FVB mice. Pathway analysis of merged transcriptomic and proteomic datasets identified potential ECM regulatory pathways involving inhibition of matrix metalloproteases, liver X receptor/retinoid X receptor, nuclear factor erythroid 2-related factor 2, notch, and cyclin-dependent kinase 5. These pathways may therefore alter ECM and confer susceptibility to disease. PMID:25896609

Genetic Background is a Key Determinant of Glomerular Extracellular Matrix Composition and Organization.

PubMed

Randles, Michael J; Woolf, Adrian S; Huang, Jennifer L; Byron, Adam; Humphries, Jonathan D; Price, Karen L; Kolatsi-Joannou, Maria; Collinson, Sophie; Denny, Thomas; Knight, David; Mironov, Aleksandr; Starborg, Toby; Korstanje, Ron; Humphries, Martin J; Long, David A; Lennon, Rachel

2015-12-01

Glomerular disease often features altered histologic patterns of extracellular matrix (ECM). Despite this, the potential complexities of the glomerular ECM in both health and disease are poorly understood. To explore whether genetic background and sex determine glomerular ECM composition, we investigated two mouse strains, FVB and B6, using RNA microarrays of isolated glomeruli combined with proteomic glomerular ECM analyses. These studies, undertaken in healthy young adult animals, revealed unique strain- and sex-dependent glomerular ECM signatures, which correlated with variations in levels of albuminuria and known predisposition to progressive nephropathy. Among the variation, we observed changes in netrin 4, fibroblast growth factor 2, tenascin C, collagen 1, meprin 1-α, and meprin 1-β. Differences in protein abundance were validated by quantitative immunohistochemistry and Western blot analysis, and the collective differences were not explained by mutations in known ECM or glomerular disease genes. Within the distinct signatures, we discovered a core set of structural ECM proteins that form multiple protein-protein interactions and are conserved from mouse to man. Furthermore, we found striking ultrastructural changes in glomerular basement membranes in FVB mice. Pathway analysis of merged transcriptomic and proteomic datasets identified potential ECM regulatory pathways involving inhibition of matrix metalloproteases, liver X receptor/retinoid X receptor, nuclear factor erythroid 2-related factor 2, notch, and cyclin-dependent kinase 5. These pathways may therefore alter ECM and confer susceptibility to disease. Copyright © 2015 by the American Society of Nephrology.

New Tricks for “Old” Domains: How Novel Architectures and Promiscuous Hubs Contributed to the Organization and Evolution of the ECM

PubMed Central

Cromar, Graham; Wong, Ka-Chun; Loughran, Noeleen; On, Tuan; Song, Hongyan; Xiong, Xuejian; Zhang, Zhaolei; Parkinson, John

2014-01-01

The extracellular matrix (ECM) is a defining characteristic of metazoans and consists of a meshwork of self-assembling, fibrous proteins, and their functionally related neighbours. Previous studies, focusing on a limited number of gene families, suggest that vertebrate complexity predominantly arose through the duplication and subsequent modification of retained, preexisting ECM genes. These genes provided the structural underpinnings to support a variety of specialized tissues, as well as a platform for the organization of spatio-temporal signaling and cell migration. However, the relative contributions of ancient versus novel domains to ECM evolution have not been quantified across the full range of ECM proteins. Here, utilizing a high quality list comprising 324 ECM genes, we reveal general and clade-specific domain combinations, identifying domains of eukaryotic and metazoan origin recruited into new roles in approximately two-third of the ECM proteins in humans representing novel vertebrate proteins. We show that, rather than acquiring new domains, sampling of new domain combinations has been key to the innovation of paralogous ECM genes during vertebrate evolution. Applying a novel framework for identifying potentially important, noncontiguous, conserved arrangements of domains, we find that the distinct biological characteristics of the ECM have arisen through unique evolutionary processes. These include the preferential recruitment of novel domains to existing architectures and the utilization of high promiscuity domains in organizing the ECM network around a connected array of structural hubs. Our focus on ECM proteins reveals that distinct types of proteins and/or the biological systems in which they operate have influenced the types of evolutionary forces that drive protein innovation. This emphasizes the need for rigorously defined systems to address questions of evolution that focus on specific systems of interacting proteins. PMID:25323955

Morphological responses of dissociated sponge cells to different organic substrata.

PubMed

Gaino, E; Magnino, G; Burlando, B; Sara', M

1993-06-01

To study interactions between sponge cells and components of the extracellular matrix (ECM), cells of the calcareous sponge Clathrina cerebrum were investigated in vitro by scanning electron microscopy. Cells were settled on glass coverslips, used as controls, and on coverslips coated with various ECM components (laminin, collagens and fibronectin), and with an adhesive substance (polylysine). Cells tended to conserve a rounded shape, producing thin, stiff processes (scleropodia) and lamellipodia, whose shape and extension varied according to the substrata. Spreading was observed only on polylysine, inducing cells to assume a fibroblast-like aspect. On laminin, cell adhesion was assured only by scleropodia. On fibronectin, scleropodia and lamellipodia were present, but reduced in size and length. On collagens, laminar processes occurred among prevailing scleropodia. Measurements of cell area and perimeter allowed statistical comparison of substrata, on the basis of their induction of cell flattening and protuberance formation. In summary, sponge cells were found to modulate their morphology in response to the external environment, expressing features for dynamic activities most fully in the presence of substances close to their natural ECM constituents. These results are discussed in the context of tissue rearrangement as a basic adaptation occurring throughout the life span of these organisms.

Patterns in spatial distribution and root trait syndromes for ecto and arbuscular mycorrhizal temperate trees in a mixed broadleaf forest.

PubMed

Valverde-Barrantes, Oscar J; Smemo, Kurt A; Feinstein, Larry M; Kershner, Mark W; Blackwood, Christopher B

2018-03-01

Functional differences between trees with arbuscular (AM) or ectomycorrhizal (ECM) partnerships influence important ecological processes including nutrient cycling, community assembly, and biomass allocation patterns. Although most broadleaf temperate forests show both mycorrhizal types, relatively few studies have addressed functional difference among coexisting mycorrhizal tree species. The maintenance of ECM associations usually requires higher C investment than AM, leading to (A) lower root biomass and (B) more conservative root trait syndromes in ECM tree species compared to AM species. Here we quantified the representation and trait syndromes of 14 canopy tree species associated with either AM or ECM fungi in a natural forest community. Our results showed that, whereas species root abundance was proportional to basal area, some ECM tree roots were largely under-represented (up to ~ 33%). Most of the under-representation was due to lower than expected root abundance of Quercus rubra and Fagus grandifolia. Functional root traits in tree species were similar, with the exception of higher tissue density in ECM species. Moreover, closely related AM and ECM exhibited similar traits, suggesting inherited trait syndrome from a common ancestor. Thus, we found little evidence of divergent functional root trait syndromes between mycorrhizal types. Cores dominated by ECM species influenced trait distribution at the community level, but not total biomass, suggesting that mycorrhizal affiliation may have a stronger effect on the spatial distribution of traits but not on biomass stocks. Our results present an important step toward relating belowground carbon dynamics to species traits, including mycorrhizal type, in broadleaf temperate forests.

Long-term fertilization, but not warming, shifts rates of ectomycorrhizal nutrient cycling in Arctic tussock tundra.

NASA Astrophysics Data System (ADS)

Dunleavy, H.; Mack, M. C.

2017-12-01

The role of ectomycorrhizae (ECM) in Arctic nutrient cycling may be changing as temperature, nutrient availability, and ECM shrub abundance and size increase. A shift in ECM function has been proposed as a possible mechanism for shrub expansion. While several studies demonstrate a higher abundance of ECM as well as community compositional shifts in response to long-term experimental warming and fertilization, direct measurements of functional responses are missing. To understand the potential role of ECM in soil biogeochemical processes of the changing Arctic, we investigated the functional response of ECM to 30 years of summer warming and increased nutrient availability by measuring potential activities of extracellular enzymes associated with nitrogen (N) and phosphorous (P) acquisition on ECM root tips. We hypothesize ECM enzyme activities will be higher with warmer temperatures. Conversely, fertilization will lower ECM enzyme activities as N and P become less limiting to host plants. Preliminary results strongly support our latter hypothesis, but not the first. Warming decreased hydrolytic P-associated and labile N-associated enzyme activities on individual root tips (pmol/min/mm2 root tip) by 30% and 83%, respectively. However, warming increased ECM abundance and did not alter community-level activities (pmol/min/cm3 soil). Fertilization decreased hydrolytic and oxidative enzymatic activities on individual root tips by 34 to 80% as well as on a community level by 67 to 93%, even though ECM shrubs were almost monodominant. The combined effect of warming and fertilization decreased labile N-associated enzyme activity by 82%, but had little effect on oxidative and other hydrolytic enzyme activities. Although both warming and fertilization decreased root tip activities, reflecting a potential reduction in plant allocation to mycorrhizal nutrient acquisition, only fertilization lowered rates of ECM nutrient cycling. The indirect relationship between ECM abundance and individual root tip activity highlights the importance of measuring ECM function to assess the role of this symbiosis in nutrient cycling.

Extracellular matrix elasticity and topography: material-based cues that affect cell function via conserved mechanisms

PubMed Central

Janson, Isaac A.; Putnam, Andrew J.

2014-01-01

Chemical, mechanical, and topographic extracellular matrix (ECM) cues have been extensively studied for their influence on cell behavior. These ECM cues alter cell adhesion, cell shape, and cell migration, and activate signal transduction pathways to influence gene expression, proliferation, and differentiation. ECM elasticity and topography, in particular, have emerged as material properties of intense focus based on strong evidence these physical cue can partially dictate stem cell differentiation. Cells generate forces to pull on their adhesive contacts, and these tractional forces appear to be a common element of cells’ responses to both elasticity and topography. This review focuses on recently published work that links ECM topography and mechanics and their influence on differentiation and other cell behaviors, We also highlight signaling pathways typically implicated in mechanotransduction that are (or may be) shared by cells subjected to topographic cues. Finally, we conclude with a brief discussion of the potential implications of these commonalities for cell based therapies and biomaterial design. PMID:24910444

Crystal Structure of Saccharomyces cerevisiae ECM4, a Xi-Class Glutathione Transferase that Reacts with Glutathionyl-(hydro)quinones

PubMed Central

Schwartz, Mathieu; Didierjean, Claude; Hecker, Arnaud; Girardet, Jean-Michel; Morel-Rouhier, Mélanie; Gelhaye, Eric; Favier, Frédérique

2016-01-01

Glutathionyl-hydroquinone reductases (GHRs) belong to the recently characterized Xi-class of glutathione transferases (GSTXs) according to unique structural properties and are present in all but animal kingdoms. The GHR ScECM4 from the yeast Saccharomyces cerevisiae has been studied since 1997 when it was found to be potentially involved in cell-wall biosynthesis. Up to now and in spite of biological studies made on this enzyme, its physiological role remains challenging. The work here reports its crystallographic study. In addition to exhibiting the general GSTX structural features, ScECM4 shows extensions including a huge loop which contributes to the quaternary assembly. These structural extensions are probably specific to Saccharomycetaceae. Soaking of ScECM4 crystals with GS-menadione results in a structure where glutathione forms a mixed disulfide bond with the cysteine 46. Solution studies confirm that ScECM4 has reductase activity for GS-menadione in presence of glutathione. Moreover, the high resolution structures allowed us to propose new roles of conserved residues of the active site to assist the cysteine 46 during the catalytic act. PMID:27736955

Measurement of Emotional/Psychological Child Maltreatment: A Review

ERIC Educational Resources Information Center

Tonmyr, Lil; Draca, Jasminka; Crain, Jennifer; MacMillan, Harriet L.

2011-01-01

Background: Emotional/psychological child maltreatment (ECM) is a major public health problem with serious consequences including emotional and behavioral problems. Nevertheless, ECM is an understudied area. Objectives: The aims of this review are to identify measures of ECM and to evaluate their psychometric properties and utilities. We provide a…

Human Pulse Wave Measurement by MEMS Electret Condenser Microphone

NASA Astrophysics Data System (ADS)

Nomura, Shusaku; Hanasaka, Yasushi; Ishiguro, Tadashi; Ogawa, Hiroshi

A micro Electret Condenser Microphone (ECM) fabricated by Micro Electro Mechanical System (MEMS) technology was employed as a novel apparatus for human pulse wave measurement. Since ECM frequency response characteristic, i.e. sensitivity, logically maintains a constant level at lower than the resonance frequency (stiffness control), the slightest pressure difference at around 1.0Hz generated by human pulse wave is expected to detect by MEMS-ECM. As a result of the verification of frequency response of MEMS-ECM, it was found that -20dB/dec of reduction in the sensitivity around 1.0Hz was engendered by a high input-impedance amplifier, i.e. the field effect transistor (FET), mounted near MEMS chip for amplifying tiny ECM signal. Therefore, MEMS-ECM is assumed to be equivalent with a differentiation circuit at around human pulse frequency. Introducing compensation circuit, human pulse wave was successfully obtained. In addition, the radial and ulnar artery tracing, and pulse wave velocity measurement at forearm were demonstrated; as illustrating a possible application of this micro device.

Comparison of root-associated communities of native and non-native ectomycorrhizal hosts in an urban landscape.

PubMed

Lothamer, K; Brown, S P; Mattox, J D; Jumpponen, A

2014-05-01

Non-native tree species are often used as ornamentals in urban landscapes. However, their root-associated fungal communities remain yet to be examined in detail. Here, we compared richness, diversity and community composition of ectomycorrhizosphere fungi in general and ectomycorrhizal (EcM) fungi in particular between a non-native Pinus nigra and a native Quercus macrocarpa across a growing season in urban parks using 454-pyrosequencing. Our data show that, while the ectomycorrhizosphere community richness and diversity did not differ between the two host, the EcM communities associated with the native host were often more species rich and included more exclusive members than those of the non-native hosts. In contrast, the ectomycorrhizosphere communities of the two hosts were compositionally clearly distinct in nonmetric multidimensional ordination analyses, whereas the EcM communities were only marginally so. Taken together, our data suggest EcM communities with broad host compatibilities and with a limited numbers of taxa with preference to the non-native host. Furthermore, many common fungi in the non-native Pinus were not EcM taxa, suggesting that the fungal communities of the non-native host may be enriched in non-mycorrhizal fungi at the cost of the EcM taxa. Finally, while our colonization estimates did not suggest a shortage in EcM inoculum for either host in urban parks, the differences in the fungi associated with the two hosts emphasize the importance of using native hosts in urban environments as a tool to conserve endemic fungal diversity and richness in man-made systems.

[Impact of cork oak management on the ectomycorrhizal fungal diversity associated with Quercus suber in the Mâamora forest (Morocco)].

PubMed

Maghnia, Fatima Z; Sanguin, Hervé; Abbas, Younes; Verdinelli, Marcello; Kerdouh, Benaissa; El Ghachtouli, Naima; Lancellotti, Enrico; Bakkali Yakhlef, Salah Eddine; Duponnois, Robin

2017-05-01

The cork oak forest is an ecosystem playing a major role in Moroccan socio-economy and biodiversity conservation. However, this ecosystem is negatively impacted by extensive human- and climate-driven pressures, causing a strong decrease in its distribution and a worsening of the desertification processes. This study aims at characterising the impact of cork oak forest management on a major actor of its functioning, the ectomycorrhizal (EcM) fungal community associated with Quercus suber, and the determination of EcM bio-indicators. The EcM fungal community has been monitored during spring and winter seasons in two sites of the Moroccan Mâamora forest, corresponding to a forest site either impacted by human activities or protected. A significant impact of cork oak forest management on the EcM fungal community has been revealed, with major differences during the summer season. The results confirmed the potential ecological significance of several EcM fungi (e.g., Cenococcum) in the sustainability of the cork oak forest functioning, but also the significant association of certain EcM fungi (Pachyphloeus, Russula, Tomentella) with a perturbation or a season, and consequently to the cork oak forest status or to climatic conditions, respectively. The development of study at the Mediterranean scale may improve the robustness of ecological models to predict the impact of global changes on this emblematic ecosystem of Mediterranean basin. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Micro- and Macrorheology of Jellyfish Extracellular Matrix

PubMed Central

Gambini, Camille; Abou, Bérengère; Ponton, Alain; Cornelissen, Annemiek J.M.

2012-01-01

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish. PMID:22225792

Micro- and macrorheology of jellyfish extracellular matrix.

PubMed

Gambini, Camille; Abou, Bérengère; Ponton, Alain; Cornelissen, Annemiek J M

2012-01-04

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The role of Mycobacterium avium complex fibronectin attachment protein in adherence to the human respiratory mucosa.

PubMed

Middleton, A M; Chadwick, M V; Nicholson, A G; Dewar, A; Groger, R K; Brown, E J; Wilson, R

2000-10-01

Mycobacterium avium complex (MAC) are opportunistic respiratory pathogens that infect non-immunocompromised patients with established lung disease, although they can also cause primary infections. The ability to bind fibronectin is conserved among many mycobacterial species. We have investigated the adherence of a sputum isolate of MAC to the mucosa of organ cultures constructed with human tissue and the contribution of M. avium fibronectin attachment protein (FAP) to the process. MAC adhered to fibrous, but not globular mucus, and to extracellular matrix (ECM) in areas of epithelial damage, but not to intact extruded cells and collagen fibres. Bacteria occasionally adhered to healthy unciliated epithelium and to cells that had degenerated exposing their contents, but never to ciliated cells. The results obtained with different respiratory tissues were similar. Two ATCC strains of MAC gave similar results. There was a significant reduction (P < 0.05) in the number of bacteria adhering to ECM after preincubation of bacteria with fibronectin and after preincubation of the tissue with M. avium FAP in a concentration-dependant manner. The number of bacteria adhering to fibrous mucus was unchanged. Immunogold labelling demonstrated fibronectin in ECM as well as in other areas of epithelial damage, but only ECM bound FAP. A Mycobacterium smegmatis strain had the same pattern of adherence to the mucosa as MAC. When the FAP gene was deleted, the strain demonstrated reduced adherence to ECM, and adherence was restored when the strain was transfected with an M. avium FAP expression construct. We conclude that MAC adheres to ECM in areas of epithelial damage via FAP and to mucus with a fibrous appearance via another adhesin. Epithelial damage exposing ECM and poor mucus clearance will predispose to MAC airway infection.

Carbon and nutrients recycling when leaves falling off: mycorrhizal association matters

NASA Astrophysics Data System (ADS)

Zhang, H., II; Lü, X. T.; Hartmann, H.; Han, X.; Trumbore, S.

2016-12-01

Root-associated mycorrhizal fungi is being increasingly recognized for their roles in influencing soil carbon (C) storage, plant growth and nutrient cycling, whereas mycorrhizae-mediated C dynamics and nutrient acquisition strategy strongly different. Because of a reinforcing feedback from belowground, how different mycorrhizal plants differ in aboveground nutrient status and recycle from senesced to green leaves remains unknown. Based on a global database of C and nutrients concentrations in plant green and senesced leaves, we further identified plant mycorrhizal types (here focus on arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants) for woody species and tested whether mycorrhizal types showing consistent effects in plant nutrient status and recycle. Generally, nutrient resorptions from senesced to green leaves for ECM plants are more conservative, balanced and sensitive to climate compare to AM plants. Specifically, we first found lower nutrients concentrations in green and senesced leaves whereas greater nutrient resorption efficiency (NuR) for ECM vs. AM plants. However, C concentration in green and senesced leaves were significant greater while NuR was lower for ECM plants. Second, compare to that for AM plants, we found a general balanced N:P resorption ratio ( 1) for ECM plants, indicating ECM plants had greater ability to balance their N and P resorption simultaneously. Third, we found NuR in N, P and K (potassium) for ECM plants were sensitive to the variation of MAT and MAP while these for AM plants showed no clear trend. Our results suggested that accounting for the influence of mycorrhizae on C and nutrient dynamics in vegetation models will be critical for predicting ecosystem responses and feedbacks to climate change.

Frequency-dependent micromechanics of cellularized biopolymer networks

NASA Astrophysics Data System (ADS)

Jones, Chris; Kim, Jihan; McIntyre, David; Sun, Bo

Mechanical interactions between cells and the extracellular matrix (ECM) influence many cellular behaviors such as growth, differentiation, and migration. These are dynamic processes in which the cells actively remodel the ECM. Reconstituted collagen gel is a common model ECM for studying cell-ECM interactions in vitro because collagen is the most abundant component of mammalian ECM and gives the ECM its material stiffness. We embed micron-sized particles in collagen and use holographic optical tweezers to apply forces to the particles in multiple directions and over a range of frequencies up to 10 Hz. We calculate the local compliance and show that it is dependent on both the direction and frequency of the applied force. Performing the same measurement on many particles allows us to characterize the spatial inhomogeneity of the mechanical properties and shows that the compliance decreases at higher frequencies. Performing these measurements on cell-populated collagen gels shows that cellular remodeling of the ECM changes the mechanical properties of the collagen and we investigate whether this change is dependent on the local strain and distance from nearby cells.

Effect of eosinophils activated with Alternaria on the production of extracellular matrix from nasal fibroblasts.

PubMed

Shin, Seung-Heon; Ye, Mi-Kyung; Choi, Sung-Yong; Kim, Yee-Hyuk

2016-06-01

Eosinophils and fibroblasts are known to play major roles in the pathogenesis of nasal polyps. Fungi are commonly found in nasal secretion and are associated with airway inflammation. To investigate whether activated eosinophils by airborne fungi can influence the production of extracellular matrix (ECM) from nasal fibroblasts. Inferior turbinate and nasal polyp fibroblasts were stimulated with Alternaria or Aspergillus, respectively, for 24 hours and ECM messenger RNA (mRNA) and protein expressions were measured. Eosinophils isolated from healthy volunteers were stimulated with Alternaria or Aspergillus for 4 hours then superoxide, eosinophil peroxidase, and transforming growth factor β1 were measured. Then activated eosinophils were cocultured with nasal fibroblasts for 24 hours, and ECM mRNA expressions were measured. Alternaria strongly enhanced ECM mRNA expression and protein production from nasal fibroblasts. Alternaria also induced the production of superoxide, eosinophil peroxidase, and transforming growth factor β1 from eosinophils, and activated eosinophils enhanced ECM mRNA expression when they were cocultured without the Transwell insert system. Eosinophils activated with Alternaria enhanced ECM mRNA expression from nasal polyp fibroblasts. Alternaria plays an important role in tissue fibrosis in the pathogenesis of nasal polyps by directly or indirectly influencing the production of ECM from nasal fibroblasts. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Computing the carbonate chemistry of the coral calcifying medium and its response to ocean acidification.

PubMed

Raybaud, Virginie; Tambutté, Sylvie; Ferrier-Pagès, Christine; Reynaud, Stéphanie; Venn, Alexander A; Tambutté, Éric; Nival, Paul; Allemand, Denis

2017-07-07

Critical to determining vulnerability or resilience of reef corals to Ocean Acidification (OA) is a clearer understanding of the extent to which corals can control carbonate chemistry in their Extracellular Calcifying Medium (ECM) where the CaCO 3 skeleton is produced. Here, we employ a mathematical framework to calculate ECM aragonite saturation state (Ω arag.(ECM) ) and carbonate system ion concentration using measurements of calcification rate, seawater characteristics (temperature, salinity and pH) and ECM pH (pH (ECM) ). Our calculations of ECM carbonate chemistry at current-day seawater pH, indicate that Ω arag.(ECM) ranges from ∼10 to 38 (mean 20.41), i.e. about 5 to 6-fold higher than seawater. Accordingly, Dissolved Inorganic Carbon (DIC) and Total Alkalinity (TA) were calculated to be around 3 times higher in the ECM than in seawater. We also assessed the effects of acidification on ECM chemical properties of the coral Stylophora pistillata. At reduced seawater pH our calculations indicate that Ω arag.(ECM) remains almost constant. DIC (ECM) and TA (ECM) gradually increase as seawater pH declines, reaching values about 5 to 6-fold higher than in seawater, respectively for DIC and TA. We propose that these ECM characteristics buffer the effect of acidification and explain why certain corals continue to produce CaCO 3 even when seawater chemistry is less favourable. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 1065.915 - PEMS instruments.

Code of Federal Regulations, 2010 CFR

2010-07-01

... max 0.5 % of max. Engine torque estimator, BSFC (This is a signal from an engine's ECM) T or BSFC 1 s... standards to account for ambient effects on PEMS. (d) ECM signals. You may use signals from the engine's electronic control module (ECM) in place of values measured by individual instruments within a PEMS, subject...

Extracellular matrix remodeling and matrix metalloproteinases (ajMMP-2 like and ajMMP-16 like) characterization during intestine regeneration of sea cucumber Apostichopus japonicus.

PubMed

Miao, Ting; Wan, Zixuan; Sun, Lina; Li, Xiaoni; Xing, Lili; Bai, Yucen; Wang, Fang; Yang, Hongsheng

2017-10-01

Remodeling of extracellular matrix (ECM) regulated by matrix metalloproteinases (MMPs) is essential for tissue regeneration. In the present study, we used immunohistochemistry (IHC) techniques against ECM components to reveal changes of ECM during intestine regeneration of Apostichopus japonicus. The expression of collagen I and laminin reduced apparently from the eviscerated intestine, while fibronectin exhibited continuous expression in all regeneration stages observed. Meanwhile, we cloned two MMP genes from A. japonicus by RACE PCR. The full-length cDNA of ajMMP-2 like is 2733bp and contains a predicted open reading frame (ORF) of 1716bp encoding 572 amino acids. The full-length cDNA of ajMMP-16 like is 2705bp and contains an ORF of 1452bp encoding 484 amino acids. The predicted protein sequences of each MMP contain two conserved domains, ZnMc_MMP and HX. Homology and phylogenetic analysis revealed that ajMMP-2 like and ajMMP-16 like share high sequence similarity with MMP-2 and MMP-16 from Strongylocentrotus purpuratus, respectively. Then we investigated spatio-temporal expression of ajMMP-2 like and ajMMP-16 like during different regeneration stages by qRT-PCR and IHC. The expression pattern of them showed a roughly opposite trend from that of ECM components. According to our results, a fibronectin-dominate temporary matrix is created in intestine regeneration, and it might provide structural integrity for matrix and promote cell movement. We also hypothesize that ajMMP-2 like and ajMMP-16 like could accelerate cell migration and regulate interaction between ECM components and growth factors. This work provides new evidence of ECM and MMPs involvement in sea cucumber regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

In vivo comparison of biomimetic approaches for tissue regeneration of the scarred vocal fold.

PubMed

Thibeault, Susan L; Klemuk, Sarah A; Smith, Marshall E; Leugers, Cecilia; Prestwich, Glenn

2009-07-01

The objective of this study was to determine if three different biomimetic approaches could facilitate tissue regeneration and improve viscoelastic properties in the scarred vocal fold lamina propria extracellular matrix (ECM). Twenty rabbit vocal folds were biopsied bilaterally; 2 months postinjury rabbits were unilaterally treated with (i) autologous fibroblasts, (ii) a semisynthetic ECM (sECM), or (iii) autologous fibroblasts encapsulated in sECM. Saline was injected as a control into the contralateral fold. Animals were sacrificed 2 months after treatment. Outcomes measured were procollagen, collagen, and fibronectin levels in the lamina propria, and tissue viscosity and elasticity across three frequency decades. All treatment groups demonstrated accelerated proliferation of the ECM. Vocal fold lamina propria treated with autologous fibroblasts were found to have significantly improved viscosity (p = 0.0077) and elasticity (p = 0.0081) compared to saline. This treatment group had significantly elevated fibronectin levels. sECM and autologous fibroblasts/sECM groups had significantly elevated levels of procollagen, collagen, and fibronectin, indicating abundant matrix production as compared to saline with viscoelastic measures that did not differ statistically from controls. The use of autologous fibroblasts led to better restoration of the vocal fold lamina propria biomechanical properties. Optimization of cell-scaffold interactions and subsequent cell behavior is necessary for utilization of scaffold and scaffold-cell approaches.

Dentin extracellular matrix (ECM) proteins: comparison to bone ECM and contribution to dynamics of dentinogenesis.

PubMed

Butler, William T; Brunn, Jan C; Qin, Chunlin

2003-01-01

Dentinogenesis involves the initial odontoblastic synthesis of a collagen-rich extracellular matrix (ECM) and predentin that is converted to dentin when the collagen fibrils become mineralized. Since the width of predentin is rather uniform, we postulate that extracellular events regulate dentinogenesis. Similarly, osteogenesis involves an initial unmineralized osteoid that is mineralized and converted to bone. To gain insights into these two processes, we compared ECM proteins in bone with those in dentin, focusing upon the sialic acid (SA)-rich proteins. We observed qualitative similarities between the SA-rich proteins, but distinct differences in the amounts of osteopontin (OPN) and dentin sialoprotein (DSP). OPN, a predominant protein in bone, was found in much smaller amounts in dentin. Conversely, DSP was abundant in dentin ECM, but found sparingly in bone. Molecular cloning experiments indicate that coding sequences for DSP and dentin phosphoprotein (DPP) are found on the same mRNA. We believe that the initial form of the precursor protein DSPP is inactive in influencing the mineralization process and that it must be activated by cleavage of peptide bonds in conserved regions. Thus, unknown proteinases would act on DSPP, possibly at the mineralization front, and liberate active DPP, which plays an initiation and regulatory role in the formation of apatite crystals. This post-translational processing reaction would represent an important control point in dentinogenesis. Recently, we identified uncleaved DSPP in dentin extracts, which should allow us to test portions of our hypothesis.

Automatic generation and simulation of urban building energy models based on city datasets for city-scale building retrofit analysis

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

Chen, Yixing; Hong, Tianzhen; Piette, Mary Ann

Buildings in cities consume 30–70% of total primary energy, and improving building energy efficiency is one of the key strategies towards sustainable urbanization. Urban building energy models (UBEM) can support city managers to evaluate and prioritize energy conservation measures (ECMs) for investment and the design of incentive and rebate programs. This paper presents the retrofit analysis feature of City Building Energy Saver (CityBES) to automatically generate and simulate UBEM using EnergyPlus based on cities’ building datasets and user-selected ECMs. CityBES is a new open web-based tool to support city-scale building energy efficiency strategic plans and programs. The technical details ofmore » using CityBES for UBEM generation and simulation are introduced, including the workflow, key assumptions, and major databases. Also presented is a case study that analyzes the potential retrofit energy use and energy cost savings of five individual ECMs and two measure packages for 940 office and retail buildings in six city districts in northeast San Francisco, United States. The results show that: (1) all five measures together can save 23–38% of site energy per building; (2) replacing lighting with light-emitting diode lamps and adding air economizers to existing heating, ventilation and air-conditioning (HVAC) systems are most cost-effective with an average payback of 2.0 and 4.3 years, respectively; and (3) it is not economical to upgrade HVAC systems or replace windows in San Francisco due to the city's mild climate and minimal cooling and heating loads. Furthermore, the CityBES retrofit analysis feature does not require users to have deep knowledge of building systems or technologies for the generation and simulation of building energy models, which helps overcome major technical barriers for city managers and their consultants to adopt UBEM.« less

Automatic generation and simulation of urban building energy models based on city datasets for city-scale building retrofit analysis

DOE PAGES

Chen, Yixing; Hong, Tianzhen; Piette, Mary Ann

2017-08-07

Buildings in cities consume 30–70% of total primary energy, and improving building energy efficiency is one of the key strategies towards sustainable urbanization. Urban building energy models (UBEM) can support city managers to evaluate and prioritize energy conservation measures (ECMs) for investment and the design of incentive and rebate programs. This paper presents the retrofit analysis feature of City Building Energy Saver (CityBES) to automatically generate and simulate UBEM using EnergyPlus based on cities’ building datasets and user-selected ECMs. CityBES is a new open web-based tool to support city-scale building energy efficiency strategic plans and programs. The technical details ofmore » using CityBES for UBEM generation and simulation are introduced, including the workflow, key assumptions, and major databases. Also presented is a case study that analyzes the potential retrofit energy use and energy cost savings of five individual ECMs and two measure packages for 940 office and retail buildings in six city districts in northeast San Francisco, United States. The results show that: (1) all five measures together can save 23–38% of site energy per building; (2) replacing lighting with light-emitting diode lamps and adding air economizers to existing heating, ventilation and air-conditioning (HVAC) systems are most cost-effective with an average payback of 2.0 and 4.3 years, respectively; and (3) it is not economical to upgrade HVAC systems or replace windows in San Francisco due to the city's mild climate and minimal cooling and heating loads. Furthermore, the CityBES retrofit analysis feature does not require users to have deep knowledge of building systems or technologies for the generation and simulation of building energy models, which helps overcome major technical barriers for city managers and their consultants to adopt UBEM.« less

Extracellular matrix components expression in human pluripotent stem cell-derived retinal organoids recapitulates retinogenesis in vivo and reveals an important role for IMPG1 and CD44 in the development of photoreceptors and interphotoreceptor matrix.

PubMed

Felemban, Majed; Dorgau, Birthe; Hunt, Nicola Claire; Hallam, Dean; Zerti, Darin; Bauer, Roman; Ding, Yuchun; Collin, Joseph; Steel, David; Krasnogor, Natalio; Al-Aama, Jumana; Lindsay, Susan; Mellough, Carla; Lako, Majlinda

2018-05-17

The extracellular matrix (ECM) plays an important role in numerous processes including cellular proliferation, differentiation, migration, maturation, adhesion guidance and axonal growth. To date, there has been no detailed analysis of the ECM distribution during retinal ontogenesis in humans and the functional importance of many ECM components is poorly understood. In this study, the expression of key ECM components in adult mouse and monkey retina, developing and adult human retina and retinal organoids derived from human pluripotent stem cells was studied. Our data indicate that basement membrane ECMs (Fibronectin and Collagen IV) were expressed in Bruch's membrane and the inner limiting membrane of the developing human retina, whilst the hyalectins (Versican and Brevican), cluster of differentiation 44 (CD44), photoreceptor-specific ECMs Interphotoreceptor Matrix Proteoglycan 1 (IMPG1) and Interphotoreceptor Matrix Proteoglycan 2 (IMPG2) were detected in the developing interphotoreceptor matrix (IPM). The expression of IMPG1, Versican and Brevican in the developing IPM was conserved between human developing retina and human pluripotent stem cell-derived retinal organoids. Blocking the action of CD44 and IMPG1 in pluripotent stem cell derived retinal organoids affected the development of photoreceptors, their inner/outer segments and connecting cilia and disrupted IPM formation, with IMPG1 having an earlier and more significant impact. Together, our data suggest an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation during human retinogenesis. The expression and the role of many extracellular matrix (ECM) components during human retinal development is not fully understood. In this study, expression of key ECM components (Collagen IV, Fibronectin, Brevican, Versican, IMPG1 and IMPG2) was investigated during human retinal ontogenesis. Collagen IV and Fibronectin were expressed in Bruch's membrane; whereas Brevican, Versican, IMPG1 & IMPG2 in the developing interphotoreceptor matrix (IPM). Retinal organoids were successfully generated from pluripotent stem cells. The expression of ECM components was examined in the retinal organoids and found to recapitulate human retinal development in vivo. Using functional blocking experiments, we were able to highlight an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation. Copyright © 2018 Acta Materialia Inc. All rights reserved.

A fibronectin receptor on Candida albicans mediates adherence of the fungus to extracellular matrix

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

Klotz, S.A.; Smith, R.L.

1991-03-01

Binding of fibronectin, an extracellular matrix (ECM) protein, to Candida albicans was measured, and adherence of the fungus to immobilized ECM proteins, fibronectin, laminin, types I and IV collagen, and subendothelial ECM was studied. 125I-labeled fibronectin was inhibited from binding to the fungus by unlabeled human plasma fibronectin and by Arg-Gly-Asp (RGD), Gly-Arg-Gly-Glu-Ser-Pro (GRGESP), and Gly-Arg-Gly-Asp-Thr-Pro (GRGDTP), but binding was not inhibited by Gly-Arg-Gly-Asp-Ser-Pro. Soluble fibronectin, RGD, GRGESP, and GRGDTP also inhibited fungal adherence to the individual immobilized ECM proteins in a complex pattern, but only soluble fibronectin (10(-7) M) inhibited fungal adherence to subendothelial ECM. Thus, C. albicans possessesmore » at least one type of cell surface receptor for binding soluble fibronectin that can be inhibited with peptides. This receptor apparently is used to bind the fungus to immobilized ECM proteins and to subendothelial ECM and may play a role in the initiation of disseminated disease by bloodborne fungi by providing for adherence of the microorganisms to ECM proteins.« less

Beyond the Matrix: The Many Non-ECM Ligands for Integrins

PubMed Central

LaFoya, Bryce; Munroe, Jordan A.; Miyamoto, Alison; Detweiler, Michael A.; Crow, Jacob J.; Gazdik, Tana

2018-01-01

The traditional view of integrins portrays these highly conserved cell surface receptors as mediators of cellular attachment to the extracellular matrix (ECM), and to a lesser degree, as coordinators of leukocyte adhesion to the endothelium. These canonical activities are indispensable; however, there is also a wide variety of integrin functions mediated by non-ECM ligands that transcend the traditional roles of integrins. Some of these unorthodox roles involve cell-cell interactions and are engaged to support immune functions such as leukocyte transmigration, recognition of opsonization factors, and stimulation of neutrophil extracellular traps. Other cell-cell interactions mediated by integrins include hematopoietic stem cell and tumor cell homing to target tissues. Integrins also serve as cell-surface receptors for various growth factors, hormones, and small molecules. Interestingly, integrins have also been exploited by a wide variety of organisms including viruses and bacteria to support infectious activities such as cellular adhesion and/or cellular internalization. Additionally, the disruption of integrin function through the use of soluble integrin ligands is a common strategy adopted by several parasites in order to inhibit blood clotting during hematophagy, or by venomous snakes to kill prey. In this review, we strive to go beyond the matrix and summarize non-ECM ligands that interact with integrins in order to highlight these non-traditional functions of integrins. PMID:29393909

Local alignment vectors reveal cancer cell-induced ECM fiber remodeling dynamics

PubMed Central

Lee, Byoungkoo; Konen, Jessica; Wilkinson, Scott; Marcus, Adam I.; Jiang, Yi

2017-01-01

Invasive cancer cells interact with the surrounding extracellular matrix (ECM), remodeling ECM fiber network structure by condensing, degrading, and aligning these fibers. We developed a novel local alignment vector analysis method to quantitatively measure collagen fiber alignment as a vector field using Circular Statistics. This method was applied to human non-small cell lung carcinoma (NSCLC) cell lines, embedded as spheroids in a collagen gel. Collagen remodeling was monitored using second harmonic generation imaging under normal conditions and when the LKB1-MARK1 pathway was disrupted through RNAi-based approaches. The results showed that inhibiting LKB1 or MARK1 in NSCLC increases the collagen fiber alignment and captures outward alignment vectors from the tumor spheroid, corresponding to high invasiveness of LKB1 mutant cancer cells. With time-lapse imaging of ECM micro-fiber morphology, the local alignment vector can measure the dynamic signature of invasive cancer cell activity and cell-migration-induced ECM and collagen remodeling and realigning dynamics. PMID:28045069

75 FR 68448 - Revisions to In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

....915 To Allow the Use of ECM Fuel Rate To Determine NTE Mass Emission Rate We are taking this... (ECM) along with other information, including the CO 2 , CO, and hydrocarbon emissions to calculate the... nonroad diesel engines will be equipped with ECMs that report fuel flow within the time frame proposed for...

A tumor growth model with deformable ECM

NASA Astrophysics Data System (ADS)

Sciumè, G.; Santagiuliana, R.; Ferrari, M.; Decuzzi, P.; Schrefler, B. A.

2014-12-01

Existing tumor growth models based on fluid analogy for the cells do not generally include the extracellular matrix (ECM), or if present, take it as rigid. The three-fluid model originally proposed by the authors and comprising tumor cells (TC), host cells (HC), interstitial fluid (IF) and an ECM, considered up to now only a rigid ECM in the applications. This limitation is here relaxed and the deformability of the ECM is investigated in detail. The ECM is modeled as a porous solid matrix with Green-elastic and elasto-visco-plastic material behavior within a large strain approach. Jauman and Truesdell objective stress measures are adopted together with the deformation rate tensor. Numerical results are first compared with those of a reference experiment of a multicellular tumor spheroid (MTS) growing in vitro, then three different tumor cases are studied: growth of an MTS in a decellularized ECM, growth of a spheroid in the presence of host cells and growth of a melanoma. The influence of the stiffness of the ECM is evidenced and comparison with the case of a rigid ECM is made. The processes in a deformable ECM are more rapid than in a rigid ECM and the obtained growth pattern differs. The reasons for this are due to the changes in porosity induced by the tumor growth. These changes are inhibited in a rigid ECM. This enhanced computational model emphasizes the importance of properly characterizing the biomechanical behavior of the malignant mass in all its components to correctly predict its temporal and spatial pattern evolution.

Identification of a conserved set of upregulated genes in mouse skeletal muscle hypertrophy and regrowth.

PubMed

Chaillou, Thomas; Jackson, Janna R; England, Jonathan H; Kirby, Tyler J; Richards-White, Jena; Esser, Karyn A; Dupont-Versteegden, Esther E; McCarthy, John J

2015-01-01

The purpose of this study was to compare the gene expression profile of mouse skeletal muscle undergoing two forms of growth (hypertrophy and regrowth) with the goal of identifying a conserved set of differentially expressed genes. Expression profiling by microarray was performed on the plantaris muscle subjected to 1, 3, 5, 7, 10, and 14 days of hypertrophy or regrowth following 2 wk of hind-limb suspension. We identified 97 differentially expressed genes (≥2-fold increase or ≥50% decrease compared with control muscle) that were conserved during the two forms of muscle growth. The vast majority (∼90%) of the differentially expressed genes was upregulated and occurred at a single time point (64 out of 86 genes), which most often was on the first day of the time course. Microarray analysis from the conserved upregulated genes showed a set of genes related to contractile apparatus and stress response at day 1, including three genes involved in mechanotransduction and four genes encoding heat shock proteins. Our analysis further identified three cell cycle-related genes at day and several genes associated with extracellular matrix (ECM) at both days 3 and 10. In conclusion, we have identified a core set of genes commonly upregulated in two forms of muscle growth that could play a role in the maintenance of sarcomere stability, ECM remodeling, cell proliferation, fast-to-slow fiber type transition, and the regulation of skeletal muscle growth. These findings suggest conserved regulatory mechanisms involved in the adaptation of skeletal muscle to increased mechanical loading. Copyright © 2015 the American Physiological Society.

Identification of a conserved set of upregulated genes in mouse skeletal muscle hypertrophy and regrowth

PubMed Central

Chaillou, Thomas; Jackson, Janna R.; England, Jonathan H.; Kirby, Tyler J.; Richards-White, Jena; Esser, Karyn A.; Dupont-Versteegden, Esther E.

2014-01-01

The purpose of this study was to compare the gene expression profile of mouse skeletal muscle undergoing two forms of growth (hypertrophy and regrowth) with the goal of identifying a conserved set of differentially expressed genes. Expression profiling by microarray was performed on the plantaris muscle subjected to 1, 3, 5, 7, 10, and 14 days of hypertrophy or regrowth following 2 wk of hind-limb suspension. We identified 97 differentially expressed genes (≥2-fold increase or ≥50% decrease compared with control muscle) that were conserved during the two forms of muscle growth. The vast majority (∼90%) of the differentially expressed genes was upregulated and occurred at a single time point (64 out of 86 genes), which most often was on the first day of the time course. Microarray analysis from the conserved upregulated genes showed a set of genes related to contractile apparatus and stress response at day 1, including three genes involved in mechanotransduction and four genes encoding heat shock proteins. Our analysis further identified three cell cycle-related genes at day and several genes associated with extracellular matrix (ECM) at both days 3 and 10. In conclusion, we have identified a core set of genes commonly upregulated in two forms of muscle growth that could play a role in the maintenance of sarcomere stability, ECM remodeling, cell proliferation, fast-to-slow fiber type transition, and the regulation of skeletal muscle growth. These findings suggest conserved regulatory mechanisms involved in the adaptation of skeletal muscle to increased mechanical loading. PMID:25554798

Effects of geometry and cell-matrix interactions on the mechanics of 3D engineered microtissues

NASA Astrophysics Data System (ADS)

Bose, Prasenjit; Eyckmans, Jeroen; Chen, Christopher; Reich, Daniel

Approaches to measure and control cell-extracellular matrix (ECM) interactions in a dynamic mechanical environment are important both for studies of mechanobiology and for tissue design for bioengineering applications. We have developed a microtissue-based platform capable of controlling the ECM alignment of 3D engineered microtissues while simultaneously permitting measurement of cellular contractile forces and the tissues' mechanical properties. The tissues self-assemble from cell-laden collagen gels placed in micro-fabricated wells containing sets of flexible elastic pillars. Tissue geometry and ECM alignment are controlled by the pillars' number, shape and location. Optical tracking of the pillars provides readout of the tissues' contractile forces. Magnetic materials bound to selected pillars allow quasi-static or dynamic stretching of the tissue, and together with simultaneous measurements of the tissues' local dynamic strain field, enable characterization of the mechanical properties of the system, including their degree of anisotropy. Results on the effects of symmetry and degree of ECM alignment and organization on the role of cell-ECM interactions in determining tissue mechanical properties will be discussed. This work is supported by NSF CMMI-1463011 and CMMI-1462710.

Targeting Heparin to Collagen within Extracellular Matrix Significantly Reduces Thrombogenicity and Improves Endothelialization of Decellularized Tissues.

PubMed

Jiang, Bin; Suen, Rachel; Wertheim, Jason A; Ameer, Guillermo A

2016-12-12

Thrombosis within small-diameter vascular grafts limits the development of bioartificial, engineered vascular conduits, especially those derived from extracellular matrix (ECM). Here we describe an easy-to-implement strategy to chemically modify vascular ECM by covalently linking a collagen binding peptide (CBP) to heparin to form a heparin derivative (CBP-heparin) that selectively binds a subset of collagens. Modification of ECM with CBP-heparin leads to increased deposition of functional heparin (by ∼7.2-fold measured by glycosaminoglycan composition) and a corresponding reduction in platelet binding (>70%) and whole blood clotting (>80%) onto the ECM. Furthermore, addition of CBP-heparin to the ECM stabilizes long-term endothelial cell attachment to the lumen of ECM-derived vascular conduits, potentially through recruitment of heparin-binding growth factors that ultimately improve the durability of endothelialization in vitro. Overall, our findings provide a simple yet effective method to increase deposition of functional heparin on the surface of ECM-based vascular grafts and thereby minimize thrombogenicity of decellularized tissue, overcoming a significant challenge in tissue engineering of bioartificial vessels and vascularized organs.

Determining Near-Bottom Fluxes of Passive Tracers in Aquatic Environments

NASA Astrophysics Data System (ADS)

Bluteau, Cynthia E.; Ivey, Gregory N.; Donis, Daphne; McGinnis, Daniel F.

2018-03-01

In aquatic systems, the eddy correlation method (ECM) provides vertical flux measurements near the sediment-water interface. The ECM independently measures the turbulent vertical velocities w' and the turbulent tracer concentration c' at a high sampling rate (> 1 Hz) to obtain the vertical flux w'c'¯ from their time-averaged covariance. This method requires identifying and resolving all the flow-dependent time (and length) scales contributing to w'c'¯. With increasingly energetic flows, we demonstrate that the ECM's current technology precludes resolving the smallest flux-contributing scales. To avoid these difficulties, we show that for passive tracers such as dissolved oxygen, w'c'¯ can be measured from estimates of two scalar quantities: the rate of turbulent kinetic energy dissipation ɛ and the rate of tracer variance dissipation χc. Applying this approach to both laboratory and field observations demonstrates that w'c'¯ is well resolved by the new method and can provide flux estimates in more energetic flows where the ECM cannot be used.

Effect of Urea and Thiourea on Generation of Xenogeneic Extracellular Matrix Scaffolds for Tissue Engineering

PubMed Central

Wong, Maelene L.; Wong, Janelle L.; Horn, Rebecca M.; Sannajust, Kimberley C.; Rice, Dawn A.

2016-01-01

Effective solubilization of proteins by chaotropes in proteomic applications motivates their use in solubilization-based antigen removal/decellularization strategies. A high urea concentration has previously been reported to significantly reduce lipophilic antigen content of bovine pericardium (BP); however, structure and function of the resultant extracellular matrix (ECM) scaffold were compromised. It has been recently demonstrated that in vivo ECM scaffold fate is determined by two primary outcome measures as follows: (1) sufficient reduction in antigen content to avoid graft-specific adaptive immune responses and (2) maintenance of native ECM structural proteins to avoid graft-specific innate responses. In this work, we assessed residual antigenicity, ECM architecture, ECM content, thermal stability, and tensile properties of BP subjected to a gradient of urea concentrations to determine whether an intermediate concentration exists at which both antigenicity and structure–function primary outcome measures for successful in vivo scaffold outcome can simultaneously be achieved. Alteration in tissue structure–function properties at various urea concentrations with decreased effectiveness for antigen removal makes use of urea-mediated antigen removal unlikely to be suitable for functional scaffold generation. PMID:27230226

Effect of calving interval and parity on milk yield per feeding day in Danish commercial dairy herds.

PubMed

Lehmann, J O; Fadel, J G; Mogensen, L; Kristensen, T; Gaillard, C; Kebreab, E

2016-01-01

The idea of managing cows for extended lactations rather than lactations of the traditional length of 1 yr primarily arose from observations of increasing problems with infertility and cows being dried off with high milk yields. However, it is vital for the success of extended lactation practices that cows are able to maintain milk yield per feeding day when the length of the calving interval (CInt) is increased. Milk yield per feeding day is defined as the cumulated lactation milk yield divided by the sum of days between 2 consecutive calvings. The main objective of this study was to investigate the milk production of cows managed for lactations of different lengths, and the primary aim was to investigate the relationship between CInt, parity, and milk yield. Five measurements of milk yield were used: energy-corrected milk (ECM) yield per feeding day, ECM yield per lactating day, cumulative ECM yield during the first 305 d of lactation, as well as ECM yield per day during early and late lactation. The analyses were based on a total of 1,379 completed lactations from cows calving between January 2007 and May 2013 in 4 Danish commercial dairy herds managed for extended lactation for several years. Herd-average CInt length ranged from 414 to 521 d. The herds had Holstein, Jersey, or crosses between Holstein, Jersey, and Red Danish cows with average milk yields ranging from 7,644 to 11,286 kg of ECM per cow per year. A significant effect of the CInt was noted on all 5 measurements of milk yield, and this effect interacted with parity for ECM per feeding day, ECM per lactating day and ECM per day during late lactation. The results showed that cows were at least able to produce equivalent ECM per feeding day with increasing CInt, and that first- and second-parity cows maintained ECM per lactating day. Cows with a CInt between 17 and 19 mo produced 476 kg of ECM more during the first 305 d compared with cows with a CInt of less than 13 mo. Furthermore, early-lactation ECM yield was greater for all cows and late-lactation ECM yield was less for second-parity and older cows when undergoing an extended compared with a shorter lactation. Increasing CInt increased the dry period length with 3 to 5d. In conclusion, the group of cows with longer CInt were able to produce at least equivalent amounts of ECM per feeding day when the CInt was up to 17 to 19 mo on these 4 commercial dairy farms. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Chronological refinement of an ice core record at Upper Fremont Glacier in south central North America

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

Schuster, Paul F.; White, David E.; Naftz, David L.

2000-02-27

The potential to use ice cores from alpine glaciers in the midlatitudes to reconstruct paleoclimatic records has not been widely recognized. Although excellent paleoclimatic records exist for the polar regions, paleoclimatic ice core records are not common from midlatitude locations. An ice core removed from the Upper Fremont Glacier in Wyoming provides evidence for abrupt climate change during the mid-1800s. Volcanic events (Krakatau and Tambora) identified from electrical conductivity measurements (ECM) and isotopic and chemical data from the Upper Fremont Glacier were reexamined to confirm and refine previous chronological estimates of the ice core. At a depth of 152 mmore » the refined age-depth profile shows good agreement (1736{+-}10 A.D.) with the {sup 14}C age date (1729{+-}95 A.D.). The {delta}{sup 18}O profile of the Upper Fremont Glacier (UFG) ice core indicates a change in climate known as the Little Ice Age (LIA). However, the sampling interval for {delta}{sup 18}O is sufficiently large (20 cm) such that it is difficult to pinpoint the LIA termination on the basis of {delta}{sup 18}O data alone. Other research has shown that changes in the {delta}{sup 18}O variance are generally coincident with changes in ECM variance. The ECM data set contains over 125,000 data points at a resolution of 1 data point per millimeter of ice core. A 999-point running average of the ECM data set and results from f tests indicates that the variance of the ECM data decreases significantly at about 108 m. At this depth, the age-depth profile predicts an age of 1845 A.D. Results indicate the termination of the LIA was abrupt with a major climatic shift to warmer temperatures around 1845 A.D. and continuing to present day. Prediction limits (error bars) calculated for the profile ages are {+-}10 years (90% confidence level). Thus a conservative estimate for the time taken to complete the LIA climatic shift to present-day climate is about 10 years, suggesting the LIA termination in alpine regions of central North America may have occurred on a relatively short (decadal) timescale. (c) 2000 American Geophysical Union.« less

New advances in probing cell–extracellular matrix interactions

PubMed Central

2017-01-01

The extracellular matrix (ECM) provides structural and biochemical support to cells within tissues. An emerging body of evidence has established that the ECM plays a key role in cell mechanotransduction – the study of coupling between mechanical inputs and cellular phenotype – through either mediating transmission of forces to the cells, or presenting mechanical cues that guide cellular behaviors. Recent progress in cell mechanotransduction research has been facilitated by advances of experimental tools, particularly microtechnologies, engineered biomaterials, and imaging and analytical methods. Microtechnologies have enabled the design and fabrication of controlled physical microenvironments for the study and measurement of cell–ECM interactions. Advances in engineered biomaterials have allowed researchers to develop synthetic ECMs that mimic tissue microenvironments and investigate the impact of altered physicochemical properties on various cellular processes. Finally, advanced imaging and spectroscopy techniques have facilitated the visualization of the complex interaction between cells and ECM in vitro and in living tissues. This review will highlight the application of recent innovations in these areas to probing cell–ECM interactions. We believe cross-disciplinary approaches, combining aspects of the different technologies reviewed here, will inspire innovative ideas to further elucidate the secrets of ECM-mediated cell control. PMID:28352896

The endogenous fluorescence of fibroblast in collagen gels as indicator of stiffness of the extracellular matrix

NASA Astrophysics Data System (ADS)

Padilla-Martinez, J. P.; Ortega-Martinez, A.; Franco, W.

2016-03-01

The stiffness or rigidity of the extracellular matrix (ECM) regulates cell response. Established mechanical tests to measure stiffness, such as indentation and tensile tests, are invasive and destructive to the sample. Endogenous or native molecules to cells and ECM components, like tryptophan and cross-links of collagen, display fluorescence upon irradiation with ultraviolet light. Most likely, the concentration of these endogenous fluorophores changes as the stiffness of the ECM changes. In this work we investigate the endogenous fluorescence of collagen gels containing fibroblasts as a non-invasive non-destructive method to measure stiffness of the ECM. Human fibroblast cells were cultured in three-dimensional gels of type I collagen (50,000 cells/ml). This construct is a simple model of tissue contraction. During contraction, changes in the excitation-emission matrix (a fluorescence map in the 240-520/290-530 nm range) of constructs were measured with a spectrofluoremeter, and changes in stiffness were measured with a standard indentation test over 16 days. Results show that a progressive increase in fluorescence of the 290/340 nm excitation-emission pair correlates with a progressive increase in stiffness (r=0.9, α=0.5). The fluorescence of this excitation-emission pair is ascribed to tryptophan and variations in the fluorescence of this pair correlate with cellular proliferation. In this tissue model, the endogenous functional fluorescence of proliferating fibroblast cells is a biomechanical marker of stiffness of the ECM.

Mechanoregulatory tumor-stroma crosstalk in pancreatic cancer: Measurements of the effects of extracellular matrix mechanics on tumor growth behavior, and vice-versa, to inform therapeutics

NASA Astrophysics Data System (ADS)

Celli, Jonathan; Jones, Dustin; El-Hamidi, Hamid; Cramer, Gwendolyn; Hanna, William; Caide, Andrew; Jafari, Seyedehrojin

The rheological properties of the extracellular matrix (ECM) have been shown to play key roles in regulating tumor growth behavior through mechanotranduction pathways. The role of the mechanical microenvironment may be particularly important tumors of the pancreas, noted for an abundance of rigid fibrotic stroma, implicated in therapeutic resistance. At the same time, cancer cells and their stromal partners (e.g. tumor associated fibroblasts) continually alter the mechanical microenvironment in response to extracellular physical and biochemical cues as part of a two-way mechanoregulatory dialog. Here, we describe experimental studies using 3D pancreatic cell cultures with customized mechanical properties, combined with optical microrheology to provide insight into tumor-driven matrix remodeling. Quantitative microscopy provides measurements of phenotypic changes accompanying systematic variation of ECM composition in collagen and laminin-rich basement membrane admixtures, while analysis of the trajectories of passive tracer particles embedded in ECM report dynamic changes in heterogeneity, microstructure and local shear modulus accompanying both ECM stiffening (fibrosis) processes, and ECM degradation near invading cells. We gratefully acknowledge funding from the National Cancer Institute, R00CA155045 (PI: Celli).

Invasion-promoting extracellular matrix composition enhances photodynamic therapy response in 3D pancreatic cancer models

NASA Astrophysics Data System (ADS)

Cramer, Gwendolyn M.; El-Hamidi, Hamid; Celli, Jonathan P.

2017-02-01

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extracellular matrix-rich stromal involvement, but it is not clear how ECM properties that affect invasiveness and chemotherapy response influence efficacy of photodynamic therapy (PDT). To disentangle the mechanical and biochemical effects of ECM composition, we measured the effects of various combinations of ECM proteins on growth behavior, invasive potential, and therapeutic response of multicellular 3D pancreatic tumor models. These spheroids were grown in attachment-free conditions before embedding in combinations of rheologically characterized collagen 1 and Matrigel combinations and treated with oxaliplatin chemotherapy and PDT. We find that cells invading from collagen-embedded tumor spheroids, the least rigid ECM substrate described here, displayed better response to PDT than to oxaliplatin chemotherapy. Overall, our results support that ECM-mediated invading PDAC populations remain responsive to PDT in conditions that induce chemoresistance.

Biophysical force regulation in 3D tumor cell invasion

NASA Astrophysics Data System (ADS)

Wu, Mingming

When embedded within 3D extracellular matrices (ECM), animal cells constantly probe and adapt to the ECM locally (at cell length scale) and exert forces and communicate with other cells globally (up to 10 times of cell length). It is now well accepted that mechanical crosstalk between animal cells and their microenvironment critically regulate cell function such as migration, proliferation and differentiation. Disruption of the cell-ECM crosstalk is implicated in a number of pathologic processes including tumor progression and fibrosis. Central to the problem of cell-ECM crosstalk is the physical force that cells generate. By measuring single cell generated force within 3D collagen matrices, we revealed a mechanical crosstalk mechanism between the tumor cells and the ECM. Cells generate sufficient force to stiffen collagen fiber network, and stiffer matrix, in return promotes larger cell force generation. Our work highlights the importance of fibrous nonlinear elasticity in regulating tumor cell-ECM interaction, and results may have implications in the rapid tissue stiffening commonly found in tumor progression and fibrosis. This work is partially supported by NIH Grants R21RR025801 and R21GM103388.

Portfolio-Scale Optimization of Customer Energy Efficiency Incentive and Marketing: Cooperative Research and Development Final Report, CRADA Number CRD-13-535

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

Brackney, Larry J.

North East utility National Grid (NGrid) is developing a portfolio-scale application of OpenStudio designed to optimize incentive and marketing expenditures for their energy efficiency (EE) programs. NGrid wishes to leverage a combination of geographic information systems (GIS), public records, customer data, and content from the Building Component Library (BCL) to form a JavaScript Object Notation (JSON) input file that is consumed by an OpenStudio-based expert system for automated model generation. A baseline model for each customer building will be automatically tuned using electricity and gas consumption data, and a set of energy conservation measures (ECMs) associated with each NGrid incentivemore » program will be applied to the model. The simulated energy performance and return on investment (ROI) will be compared with customer hurdle rates and available incentives to A) optimize the incentive required to overcome the customer hurdle rate and B) determine if marketing activity associated with the specific ECM is warranted for that particular customer. Repeated across their portfolio, this process will enable NGrid to substantially optimize their marketing and incentive expenditures, targeting those customers that will likely adopt and benefit from specific EE programs.« less

A combinatorial extracellular matrix platform identifies cell-extracellular matrix interactions that correlate with metastasis

PubMed Central

Reticker-Flynn, Nathan E.; Braga Malta, David F.; Winslow, Monte M.; Lamar, John M.; Xu, Mary J.; Underhill, Gregory H.; Hynes, Richard O.; Jacks, Tyler E.; Bhatia, Sangeeta N.

2013-01-01

Extracellular matrix interactions play essential roles in normal physiology and many pathological processes. While the importance of ECM interactions in metastasis is well documented, systematic approaches to identify their roles in distinct stages of tumorigenesis have not been described. Here we report a novel screening platform capable of measuring phenotypic responses to combinations of ECM molecules. Using a genetic mouse model of lung adenocarcinoma, we measure the ECM-dependent adhesion of tumor-derived cells. Hierarchical clustering of the adhesion profiles differentiates metastatic cell lines from primary tumor lines. Furthermore, we uncovered that metastatic cells selectively associate with fibronectin when in combination with galectin-3, galectin-8, or laminin. We show that these molecules correlate with human disease and that their interactions are mediated in part by α3β1 integrin. Thus, our platform allowed us to interrogate interactions between metastatic cells and their microenvironments, and identified ECM and integrin interactions that could serve as therapeutic targets. PMID:23047680

Contributions of adipose tissue architectural and tensile properties toward defining healthy and unhealthy obesity.

PubMed

Lackey, Denise E; Burk, David H; Ali, Mohamed R; Mostaedi, Rouzbeh; Smith, William H; Park, Jiyoung; Scherer, Philipp E; Seay, Shundra A; McCoin, Colin S; Bonaldo, Paolo; Adams, Sean H

2014-02-01

The extracellular matrix (ECM) plays an important role in the maintenance of white adipose tissue (WAT) architecture and function, and proper ECM remodeling is critical to support WAT malleability to accommodate changes in energy storage needs. Obesity and adipocyte hypertrophy place a strain on the ECM remodeling machinery, which may promote disordered ECM and altered tissue integrity and could promote proinflammatory and cell stress signals. To explore these questions, new methods were developed to quantify omental and subcutaneous WAT tensile strength and WAT collagen content by three-dimensional confocal imaging, using collagen VI knockout mice as a methods validation tool. These methods, combined with comprehensive measurement of WAT ECM proteolytic enzymes, transcript, and blood analyte analyses, were used to identify unique pathophenotypes of metabolic syndrome and type 2 diabetes mellitus in obese women, using multivariate statistical modeling and univariate comparisons with weight-matched healthy obese individuals. In addition to the expected differences in inflammation and glycemic control, approximately 20 ECM-related factors, including omental tensile strength, collagen, and enzyme transcripts, helped discriminate metabolically compromised obesity. This is consistent with the hypothesis that WAT ECM physiology is intimately linked to metabolic health in obese humans, and the studies provide new tools to explore this relationship.

Extracellular Matrix and Dermal Fibroblast Function in the Healing Wound

PubMed Central

Tracy, Lauren E.; Minasian, Raquel A.; Caterson, E.J.

2016-01-01

Significance: Fibroblasts play a critical role in normal wound healing. Various extracellular matrix (ECM) components, including collagens, fibrin, fibronectin, proteoglycans, glycosaminoglycans, and matricellular proteins, can be considered potent protagonists of fibroblast survival, migration, and metabolism. Recent Advances: Advances in tissue culture, tissue engineering, and ex vivo models have made the examination and precise measurements of ECM components in wound healing possible. Likewise, the development of specific transgenic animal models has created the opportunity to characterize the role of various ECM molecules in healing wounds. In addition, the recent characterization of new ECM molecules, including matricellular proteins, dermatopontin, and FACIT collagens (Fibril-Associated Collagens with Interrupted Triple helices), further demonstrates our cursory knowledge of the ECM in coordinated wound healing. Critical Issues: The manipulation and augmentation of ECM components in the healing wound is emerging in patient care, as demonstrated by the use of acellular dermal matrices, tissue scaffolds, and wound dressings or topical products bearing ECM proteins such as collagen, hyaluronan (HA), or elastin. Once thought of as neutral structural proteins, these molecules are now known to directly influence many aspects of cellular wound healing. Future Directions: The role that ECM molecules, such as CCN2, osteopontin, and secreted protein, acidic and rich in cysteine, play in signaling homing of fibroblast progenitor cells to sites of injury invites future research as we continue investigating the heterotopic origin of certain populations of fibroblasts in a healing wound. Likewise, research into differently sized fragments of the same polymeric ECM molecule is warranted as we learn that fragments of molecules such as HA and tenascin-C can have opposing effects on dermal fibroblasts. PMID:26989578

Increased extracellular matrix density decreases MCF10A breast cell acinus formation in 3D culture conditions.

PubMed

Lance, Amanda; Yang, Chih-Chao; Swamydas, Muthulekha; Dean, Delphine; Deitch, Sandy; Burg, Karen J L; Dréau, Didier

2016-01-01

The extracellular matrix (ECM) contributes to the generation and dynamic of normal breast tissue, in particular to the generation of polarized acinar and ductal structures. In vitro 3D culture conditions, including variations in the composition of the ECM, have been shown to directly influence the formation and organization of acinus-like and duct-like structures. Furthermore, the density of the ECM appears to also play a role in the normal mammary tissue and tumour formation. Here we show that the density of the ECM directly influences the number, organization and function of breast acini. Briefly, non-malignant human breast MCF10A cells were incubated in increasing densities of a Matrigel®-collagen I matrix. Elastic moduli near and distant to the acinus structures were measured by atomic force microscopy, and the number of acinus structures was determined. Immunochemistry was used to investigate the expression levels of E-cadherin, laminin, matrix metalloproteinase-14 and ß-casein in MCF10A cells. The modulus of the ECM was significantly increased near the acinus structures and the number of acinus structures decreased with the increase in Matrigel-collagen I density. As evaluated by the expression of laminin, the organization of the acinus structures present was altered as the density of the ECM increased. Increases in both E-cadherin and MMP14 expression by MCF10A cells as ECM density increased were also observed. In contrast, MCF10A cells expressed lower ß-casein levels as the ECM density increased. Taken together, these observations highlight the key role of ECM density in modulating the number, organization and function of breast acini. Copyright © 2013 John Wiley & Sons, Ltd.

Quantification of focal adhesion dynamics of cell movement based on cell-induced collagen matrix deformation using second-harmonic generation microscopy.

PubMed

Kang, Yong Guk; Jang, Hwanseok; Yang, Taeseok Daniel; Notbohm, Jacob; Choi, Youngwoon; Park, Yongdoo; Kim, Beop-Min

2018-06-01

Mechanical interactions of living cells with the surrounding environment via focal adhesion (FA) in three dimensions (3-D) play a key role in dynamic biological events, such as tissue regeneration, wound healing, and cancer invasion. Recently, several methods for observing 3-D cell-extracellular matrix (ECM) interactions have been reported, lacking solid and quantitative analysis on the dynamics of the physical interaction between the cell and the ECM. We measured the submicron displacements of ECM deformation in 3-D due to protrusion-retraction dynamics during cell migration, using second-harmonic generation without labeling the matrix structures. We then quantitatively analyzed the mechanical deformation between the ECM and the cells based on spatiotemporal volumetric correlations. The greatest deformations within the collagen matrix were found to occur at sites of colocalization of the FA site-related proteins vinculin and actin, which confirms that FA sites play a critical role in living cells within the ECM as a point for adhesion, traction, and migration. We believe that this modality can be used in studies of cell-ECM interaction during angiogenesis, wound healing, and metastasis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Extracellular matrix production by human osteoblasts cultured on biodegradable polymers applicable for tissue engineering.

PubMed

El-Amin, S F; Lu, H H; Khan, Y; Burems, J; Mitchell, J; Tuan, R S; Laurencin, C T

2003-03-01

The nature of the extracellular matrix (ECM) is crucial in regulating cell functions via cell-matrix interactions, cytoskeletal organization, and integrin-mediated signaling. In bone, the ECM is composed of proteins such as collagen (CO), fibronectin (FN), laminin (LM), vitronectin (VN), osteopontin (OP) and osteonectin (ON). For bone tissue engineering, the ECM should also be considered in terms of its function in mediating cell adhesion to biomaterials. This study examined ECM production, cytoskeletal organization, and adhesion of primary human osteoblastic cells on biodegradable matrices applicable for tissue engineering, namely polylactic-co-glycolic acid 50:50 (PLAGA) and polylactic acid (PLA). We hypothesized that the osteocompatible, biodegradable polymer surfaces promote the production of bone-specific ECM proteins in a manner dependent on polymer composition. We first examined whether the PLAGA and PLA matrices could support human osteoblastic cell growth by measuring cell adhesion at 3, 6 and 12h post-plating. Adhesion on PLAGA was consistently higher than on PLA throughout the duration of the experiment, and comparable to tissue culture polystyrene (TCPS). ECM components, including CO, FN, LM, ON, OP and VN, produced on the surface of the polymers were quantified by ELISA and localized by immunofluorescence staining. All of these proteins were present at significantly higher levels on PLAGA compared to PLA or TCPS surfaces. On PLAGA, OP and ON were the most abundant ECM components, followed by CO, FN, VN and LN. Immunofluorescence revealed an extracellular distribution for CO and FN, whereas OP and ON were found both intracellularly as well as extracellularly on the polymer. In addition, the actin cytoskeletal network was more extensive in osteoblasts cultured on PLAGA than on PLA or TCPS. In summary, we found that osteoblasts plated on PLAGA adhered better to the substrate, produced higher levels of ECM molecules, and showed greater cytoskeletal organization than on PLA and TCPS. We propose that this difference in ECM composition is functionally related to the enhanced cell adhesion observed on PLAGA. There is initial evidence that specific composition of the PLAGA polymer favors the ECM. Future studies will seek to optimize ECM production on these matrices for bone tissue engineering applications.

75 FR 68575 - Revisions To In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

... this rule. F. Revision of 40 CFR 1065.915 To Allow the Use of ECM Fuel Rate To Determine NTE Mass... electronic control module (ECM) along with other information, including the CO 2 , CO, and hydrocarbon... all large horsepower nonroad diesel engines will [[Page 68580

Contribution of titin and extracellular matrix to passive pressure and measurement of sarcomere length in the mouse left ventricle

PubMed Central

Chung, Charles S; Granzier, Henk L

2011-01-01

It remains to be established to what degree titin and the extracellular matrix (ECM) contribute to passive pressure in the left ventricle (LV). Thus, we aimed to elucidate the contribution of major molecular determinants of passive pressure in the normal mouse LV. Furthermore, we determined the working sarcomere length (SL) range of the LV to bridge our findings to earlier work in skinned muscle fibers. We utilized Frank-Starling type protocols to obtain diastolic pressure-volume relationships (PVR) in Langendorff perfused isolated LVs. To quantify the molecular contribution of titin and ECM, we innovated on methods of fiber mechanics to chemically permeabilize intact LVs and measure a fully passive PVR. To differentially dissect the contributions of the ECM and titin, we utilized myofilament extraction techniques in permeabilized LVs, measuring passive PVRs at each stage in the protocol. Myofilament extraction suggests that titin contributes ~80% of passive pressures in the heart. Langendorff perfusion was also used to chemically fix passive and BaCl2 activated hearts at specific volumes to determine that the maximal working SL range of the midwall LV fibers is approximately 1.8-2.2 μm. A model of the passive SL-Volume relationship was then used to estimate the pressure-SL relationships, indicating that the ECM contribution does not exceed titin's contribution until large volumes with SLs>~2.2μm. In conclusion, within physiological volumes titin is the dominant contributor to LV passive pressure, and ECM-based pressures dominates at larger volumes. PMID:21255582

Peroxidase enzymes regulate collagen extracellular matrix biosynthesis.

PubMed

DeNichilo, Mark O; Panagopoulos, Vasilios; Rayner, Timothy E; Borowicz, Romana A; Greenwood, John E; Evdokiou, Andreas

2015-05-01

Myeloperoxidase and eosinophil peroxidase are heme-containing enzymes often physically associated with fibrotic tissue and cancer in various organs, without any direct involvement in promoting fibroblast recruitment and extracellular matrix (ECM) biosynthesis at these sites. We report herein novel findings that show peroxidase enzymes possess a well-conserved profibrogenic capacity to stimulate the migration of fibroblastic cells and promote their ability to secrete collagenous proteins to generate a functional ECM both in vitro and in vivo. Mechanistic studies conducted using cultured fibroblasts show that these cells are capable of rapidly binding and internalizing both myeloperoxidase and eosinophil peroxidase. Peroxidase enzymes stimulate collagen biosynthesis at a post-translational level in a prolyl 4-hydroxylase-dependent manner that does not require ascorbic acid. This response was blocked by the irreversible myeloperoxidase inhibitor 4-amino-benzoic acid hydrazide, indicating peroxidase catalytic activity is essential for collagen biosynthesis. These results suggest that peroxidase enzymes, such as myeloperoxidase and eosinophil peroxidase, may play a fundamental role in regulating the recruitment of fibroblast and the biosynthesis of collagen ECM at sites of normal tissue repair and fibrosis, with enormous implications for many disease states where infiltrating inflammatory cells deposit peroxidases. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Essential roles of fibronectin in the development of the left-right embryonic body plan.

PubMed

Pulina, Maria V; Hou, Shuan-Yu; Mittal, Ashok; Julich, Dorthe; Whittaker, Charlie A; Holley, Scott A; Hynes, Richard O; Astrof, Sophie

2011-06-15

Studies in Xenopus laevis suggested that cell-extracellular matrix (ECM) interactions regulate the development of the left-right axis of asymmetry; however, the identities of ECM components and their receptors important for this process have remained unknown. We discovered that FN is required for the establishment of the asymmetric gene expression pattern in early mouse embryos by regulating morphogenesis of the node, while cellular fates of the nodal cells, canonical Wnt and Shh signaling within the node were not perturbed by the absence of FN. FN is also required for the expression of Lefty 1/2 and activation of SMADs 2 and 3 at the floor plate, while cell fate specification of the notochord and the floor plate, as well as signaling within and between these two embryonic organizing centers remained intact in FN-null mutants. Furthermore, our experiments indicate that a major cell surface receptor for FN, integrin α5β1, is also required for the development of the left-right asymmetry, and that this requirement is evolutionarily conserved in fish and mice. Taken together, our studies demonstrate the requisite role for a structural ECM protein and its integrin receptor in the development of the left-right axis of asymmetry in vertebrates. Copyright © 2011 Elsevier Inc. All rights reserved.

Mycorrhizal strategies for nitrogen acquisition have divergent effects on soil carbon

NASA Astrophysics Data System (ADS)

Wurzburger, N.; Brookshire, J.

2016-12-01

Most land plants acquire nitrogen (N) through associations with mycorrhizal fungi, but these symbioses employ contrasting strategies for N acquisition, which may lead to different stocks of soil carbon (C). Here we experimentally test the hypothesis that contrasting strategies for N acquisition by arbuscular (AM) and ectomycorrhizal (ECM) plants drive divergent patterns in soil decomposer activity and C loss. By employing a simple mesocosm system where we grew AM and ECM trees in 13C- and 15N-enriched organic matter, we quantified loss rates of soil C, uptake of N and net contributions of new plant C to soil. We found that AM trees promoted greater soil C loss relative to ECM trees and key mechanisms of N acquisition explained this pattern. AM trees were less dependent on biomass C to acquire N than ECM trees, and N uptake was correlated with soil C loss for AM, but not ECM trees. Further, while new plant C inputs stimulated soil C loss in both symbioses, we detected plant C inputs more frequently and measured higher rates of decomposer activity in soils colonized by AM relative to ECM trees. Together, our findings suggest that contrasting strategies of N acquisition by AM and ECM, including differences in stimulating decomposition, explain mycorrhizal effects on soil C. Our study provides experimental demonstration of the key mechanisms by which mycorrhizal strategies may give rise to broad patterns in soil C across terrestrial ecosystems.

[Biocompatibility testing of various biomaterials as dependent on immune status].

PubMed

Endres, S; Landgraff, M; Kratz, M; Wilke, A

2004-01-01

This study deals with the ingrowth behaviour of biomaterials (hydroxyapatite, cp-titanium, cobalt-chromium-molybdenum and PAEK) in relationship to the immunological competence in an animal model. Measured were the production of extracellular matrix (ECM) after implantation in non-immunocompetent naked mice and immunocompetent wild mice. Intention of the trial was to find out if either the immunological competence or the duration of implantation influences the quantity of produced ECM. In addition, the ingrowth behaviour was investigated under these conditions by using four different biomaterials. Biomaterials (hydroxyapatite, cp-titanium, cobalt-chromium-molybdenum and PAEK) were implanted for 14 or 60 days, respectively. CLSM, SEM and SEM-EDX were used for analysis of the ECM and for measuring the distance between ECM and the biomaterials. CLSM was also used for the detection of collagen I and III as a parameter of the quality of osteointegration. In all cases a matrix grew on the surface of the biomaterials. The CLSM detected a co-localisation of collagen I and III. In the case of hydroxyapatite collagen I and III were found at a distance of 1 micro m over the surface. The largest space between the surface of the implant and the ECM was found in the case of PAEK. The smallest space was in the case of hydroxyapatite. In all investigated biomaterials the proportion of collagen I to collagen III varied through the duration of implantation. As is known from the literature we found different ingrowth behaviours on using different biomaterials. Furthermore, we found a statistically significant influence of the immunological competence of the host with regard to ECM production. We draw the conclusion that immunological competence improves the ingrowth behaviour of biomaterials.

Electrodiagnostic Evaluation of Individuals Implanted With Extracellular Matrix for the Treatment of Volumetric Muscle Injury: Case Series

PubMed Central

Han, Nami; Yabroudi, Mohammad A.; Stearns-Reider, Kristen; Helkowski, Wendy; Sicari, Brian M.; Rubin, J. Peter; Badylak, Stephen F.; Boninger, Michael L.

2016-01-01

Background Electrodiagnosis can reveal the nerve and muscle changes following surgical placement of an extracellular matrix (ECM) bioscaffold for treatment of volumetric muscle loss (VML). Objective The purpose of this study was to characterize nerve conduction study (NCS) and electromyography (EMG) changes following ECM bioscaffold placement in individuals with VML. The ability of presurgical NCS and EMG to be used as a tool to help identify candidates who are likely to display improvements postsurgically also was explored. Design A longitudinal case series design was used. Methods The study was conducted at the McGowan Institute for Regenerative Medicine at the University of Pittsburgh. Eight individuals with a history of chronic VML participated. The intervention was surgical placement of an ECM bioscaffold at the site of VML. The strength of the affected region was measured using a handheld dynamometer, and electrophysiologic evaluation was conducted on the affected limb with standard method of NCS and EMG. All measurements were obtained the day before surgery and repeated 6 months after surgery. Results Seven of the 8 participants had a preoperative electrodiagnosis of incomplete mononeuropathy within the site of VML. After ECM treatment, 5 of the 8 participants showed improvements in NCS amplitude or needle EMG parameters. The presence of electrical activity within the scaffold remodeling site was concomitant with clinical improvement in muscle strength. Limitations This study had a small sample size, and participants served as their own controls. The electromyographers and physical therapists performing the evaluation were not blinded. Conclusions Electrodiagnostic data provide objective evidence of physiological improvements in muscle function following ECM placement at sites of VML. Future studies are warranted to further investigate the potential of needle EMG as a predictor of successful outcomes following ECM treatment for VML. PMID:26564252

A three-dimensional collagen-fiber network model of the extracellular matrix for the simulation of the mechanical behaviors and micro structures.

PubMed

Dong, Shoubin; Huang, Zetao; Tang, Liqun; Zhang, Xiaoyang; Zhang, Yongrou; Jiang, Yi

2017-07-01

The extracellular matrix (ECM) provides structural and biochemical support to cells and tissues, which is a critical factor for modulating cell dynamic behavior and intercellular communication. In order to further understand the mechanisms of the interactive relationship between cell and the ECM, we developed a three-dimensional (3D) collagen-fiber network model to simulate the micro structure and mechanical behaviors of the ECM and studied the stress-strain relationship as well as the deformation of the ECM under tension. In the model, the collagen-fiber network consists of abundant random distributed collagen fibers and some crosslinks, in which each fiber is modeled as an elastic beam and a crosslink is modeled as a linear spring with tensile limit, it means crosslinks will fail while the tensile forces exceed the limit of spring. With the given parameters of the beam and the spring, the simulated tensile stress-strain relation of the ECM highly matches the experimental results including damaged and failed behaviors. Moreover, by applying the maximal inscribed sphere method, we measured the size distribution of pores in the fiber network and learned the variation of the distribution with deformation. We also defined the alignment of the collagen-fibers to depict the orientation of fibers in the ECM quantitatively. By the study of changes of the alignment and the damaged crosslinks against the tensile strain, this paper reveals the comprehensive mechanisms of four stages of 'toe', 'linear', 'damage' and 'failure' in the tensile stress-strain relation of the ECM which can provide further insight in the study of cell-ECM interaction.

Nitrogen fertilization decouples roots and microbes: Reductions in belowground carbon allocation limit microbial activity

NASA Astrophysics Data System (ADS)

Carrara, J.; Walter, C. A.; Govindarajulu, R.; Hawkins, J.; Brzostek, E. R.

2017-12-01

Nitrogen (N) deposition has enhanced the ability of trees to capture atmospheric carbon (C). The effect of elevated N on belowground C cycling, however, is variable and response mechanisms are largely unknown. Recent research has highlighted distinct differences between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) trees in the strength of root-microbial interactions. In particular, ECM trees send more C to rhizosphere microbes to stimulate enzyme activity and nutrient mobilization than AM trees, which primarily rely on saprotrophic microbes to mobilize N. As such, we hypothesized that N fertilization would weaken root-microbial interactions and soil decomposition in ECM stands more than in AM stands. To test this hypothesis, we measured root-microbial interactions in ECM and AM plots in two long-term N fertilization studies, the Fernow Experimental Forest, WV and Bear Brook Watershed, ME. We found that N fertilization led to declines in plant C allocation belowground to fine root biomass, branching, and root exudation in ECM stands to a greater extent than in AM stands. As ECM roots are tightly coupled to the soil microbiome through energy and nutrient exchange, reductions in belowground C allocation were mirrored by shifts in microbial community composition and reductions in fungal gene expression. These shifts were accompanied by larger reductions in fungal-derived lignolytic and hydrolytic enzyme activity in ECM stands than in AM stands. In contrast, as the AM soil microbiome is less reliant on trees for C and are more adapted to high inorganic nutrient environments, the soil metagenome and transcriptome were more resilient to decreases in belowground C allocation. Collectively, our results indicate the N fertilization decoupled root-microbial interactions by reducing belowground carbon allocation in ECM stands. Thus, N fertilization may reduce soil turnover and increase soil C storage to a greater extent in forests dominated by ECM than AM trees.

Game and Information Theory Analysis of Electronic Counter Measures in Pursuit-Evasion Games

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

Griffin, Christopher H

Two-player Pursuit-Evasion games in the literature typically either assume both players have perfect knowledge of the opponent s positions or use primitive sensing models. This unrealistically skews the problem in favor of the pursuer who need only maintain a faster velocity at all turning radii. In real life, an evader usually escapes when the pursuer no longer knows the evader s position. In our previous work, we modeled pursuit-evasion without perfect information as a two-player bi-matrix game by using a realistic sensor model and information theory to compute game theoretic payoff matrices. That game has a saddle point when themore » evader uses strategies that exploit sensor limitations, while the pursuer relies on strategies that ignore the sensing limitations. In this paper, we consider for the first time the effect of many types of electronic counter measures (ECM) on pursuit evasion games. The evader s decision to initiate its ECM is modeled as a function of the distance between the players. Simulations show how to find optimal strategies for ECM use when initial conditions are known. We also discuss the effectiveness of different ECM technologies in pursuit-evasion games.« less

Laser speckle micro-rheology for biomechanical evaluation of breast tumors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hajjarian Kashany, Zeinab; Nadkarni, Seemantini K.

2016-03-01

The stiffness of the extra cellular matrix (ECM) is recognized as a key regulator of cancer cell proliferation, migration and invasion. Therefore technologies that quantify ECM stiffness with micro-scale scale resolution will likely provide important insights into neoplastic progression. Laser Speckle Micro-Rheology (LSM) is a novel optical tool for measuring tissue viscoelastic properties with micro-scale resolution. In LSM, speckle images are collected through an objective lens by a high-speed camera. Spatio-temporal correlation analysis of speckle frames yields the intensity autocorrelation function, g2(t), for each pixel, and subsequently a 2D map of viscoelastic modulus, G*(ω) is reconstructed. Here, we investigate the utility of LSM for micro-mechanical evaluation of the ECM in human breast lesions. Specimens collected 18 women undergoing lumpectomy or mastectomy were evaluated with LSM. Because collagen is the key protein associated with ECM stiffness, G*(ω) maps obtained from LSM were compared with collagen content measured by second harmonic generation (SHG) microscopy. Regions of low G*(ω), identified by LSM, corresponded to low-intensity SHG signal and adipose tissue. Likewise, regions with high G*(ω) in LSM images matched high intensity SHG signal caused by desmoplastic collagen accumulation. Quantitative regression analysis demonstrated a strong, statistically significant correlation between G*(ω) and SHG signal intensity (R=0.66 p< 0.01). These findings highlight the capability of LSM for quantifying the ECM micro-mechanics, potentially providing important insights into the biomechanical regulators of breast cancer progression.

Attenuation of Lipopolysaccharide-Induced Lung Vascular Stiffening by Lipoxin Reduces Lung Inflammation

PubMed Central

Meng, Fanyong; Mambetsariev, Isa; Tian, Yufeng; Beckham, Yvonne; Meliton, Angelo; Leff, Alan; Gardel, Margaret L.; Allen, Michael J.; Birukov, Konstantin G.

2015-01-01

Reversible changes in lung microstructure accompany lung inflammation, although alterations in tissue micromechanics and their impact on inflammation remain unknown. This study investigated changes in extracellular matrix (ECM) remodeling and tissue stiffness in a model of LPS-induced inflammation and examined the role of lipoxin analog 15-epi-lipoxin A4 (eLXA4) in the reduction of stiffness-dependent exacerbation of the inflammatory process. Atomic force microscopy measurements of live lung slices were used to directly measure local tissue stiffness changes induced by intratracheal injection of LPS. Effects of LPS on ECM properties and inflammatory response were evaluated in an animal model of LPS-induced lung injury, live lung tissue slices, and pulmonary endothelial cell (EC) culture. In vivo, LPS increased perivascular stiffness in lung slices monitored by atomic force microscopy and stimulated expression of ECM proteins fibronectin, collagen I, and ECM crosslinker enzyme, lysyl oxidase. Increased stiffness and ECM remodeling escalated LPS-induced VCAM1 and ICAM1 expression and IL-8 production by lung ECs. Stiffness-dependent exacerbation of inflammatory signaling was confirmed in pulmonary ECs grown on substrates with high and low stiffness. eLXA4 inhibited LPS-increased stiffness in lung cross sections, attenuated stiffness-dependent enhancement of EC inflammatory activation, and restored lung compliance in vivo. This study shows that increased local vascular stiffness exacerbates lung inflammation. Attenuation of local stiffening of lung vasculature represents a novel mechanism of lipoxin antiinflammatory action. PMID:24992633

Dominant mycorrhizal association of trees alters carbon and nutrient cycling by selecting for microbial groups with distinct enzyme function.

PubMed

Cheeke, Tanya E; Phillips, Richard P; Brzostek, Edward R; Rosling, Anna; Bever, James D; Fransson, Petra

2017-04-01

While it is well established that plants associating with arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi cycle carbon (C) and nutrients in distinct ways, we have a limited understanding of whether varying abundance of ECM and AM plants in a stand can provide integrative proxies for key biogeochemical processes. We explored linkages between the relative abundance of AM and ECM trees and microbial functioning in three hardwood forests in southern Indiana, USA. Across each site's 'mycorrhizal gradient', we measured fungal biomass, fungal : bacterial (F : B) ratios, extracellular enzyme activities, soil carbon : nitrogen ratio, and soil pH over a growing season. We show that the percentage of AM or ECM trees in a plot promotes microbial communities that both reflect and determine the C to nutrient balance in soil. Soils dominated by ECM trees had higher F : B ratios and more standing fungal biomass than AM stands. Enzyme stoichiometry in ECM soils shifted to higher investment in extracellular enzymes needed for nitrogen and phosphorus acquisition than in C-acquisition enzymes, relative to AM soils. Our results suggest that knowledge of mycorrhizal dominance at the stand or landscape scale may provide a unifying framework for linking plant and microbial community dynamics, and predicting their effects on ecological function. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Fibrous nonlinear elasticity enables positive mechanical feedback between cells and ECMs

PubMed Central

Hall, Matthew S.; Alisafaei, Farid; Ban, Ehsan; Feng, Xinzeng; Hui, Chung-Yuen; Shenoy, Vivek B.; Wu, Mingming

2016-01-01

In native states, animal cells of many types are supported by a fibrous network that forms the main structural component of the ECM. Mechanical interactions between cells and the 3D ECM critically regulate cell function, including growth and migration. However, the physical mechanism that governs the cell interaction with fibrous 3D ECM is still not known. In this article, we present single-cell traction force measurements using breast tumor cells embedded within 3D collagen matrices. We recreate the breast tumor mechanical environment by controlling the microstructure and density of type I collagen matrices. Our results reveal a positive mechanical feedback loop: cells pulling on collagen locally align and stiffen the matrix, and stiffer matrices, in return, promote greater cell force generation and a stiffer cell body. Furthermore, cell force transmission distance increases with the degree of strain-induced fiber alignment and stiffening of the collagen matrices. These findings highlight the importance of the nonlinear elasticity of fibrous matrices in regulating cell–ECM interactions within a 3D context, and the cell force regulation principle that we uncover may contribute to the rapid mechanical tissue stiffening occurring in many diseases, including cancer and fibrosis. PMID:27872289

Phylotranscriptomic analysis uncovers a wealth of tissue inhibitor of metalloproteinases variants in echinoderms

PubMed Central

Clouse, Ronald M.; Linchangco, Gregorio V.; Kerr, Alexander M.; Reid, Robert W.; Janies, Daniel A.

2015-01-01

Tissue inhibitors of metalloproteinases (TIMPs) help regulate the extracellular matrix (ECM) in animals, mostly by inhibiting matrix metalloproteinases (MMPs). They are important activators of mutable collagenous tissue (MCT), which have been extensively studied in echinoderms, and the four TIMP copies in humans have been studied for their role in cancer. To understand the evolution of TIMPs, we combined 405 TIMPs from an echinoderm transcriptome dataset built from 41 specimens representing all five classes of echinoderms with variants from protostomes and chordates. We used multiple sequence alignment with various stringencies of alignment quality to cull highly divergent sequences and then conducted phylogenetic analyses using both nucleotide and amino acid sequences. Phylogenetic hypotheses consistently recovered TIMPs as diversifying in the ancestral deuterostome and these early lineages continuing to diversify in echinoderms. The four vertebrate TIMPs diversified from a single copy in the ancestral chordate, all other copies being lost. Consistent with greater MCT needs owing to body wall liquefaction, evisceration, autotomy and reproduction by fission, holothuroids had significantly more TIMPs and higher read depths per contig. Ten cysteine residues, an HPQ binding site and several other residues were conserved in at least 70% of all TIMPs. The conservation of binding sites and the placement of echinoderm TIMPs involved in MCT modification suggest that ECM regulation remains the primary function of TIMP genes, although within this role there are a large number of specialized copies. PMID:27017967

Therapeutic Strategies for Modulating the Extracellular Matrix to Improve Pancreatic Islet Function and Survival After Transplantation.

PubMed

Smink, Alexandra M; de Vos, Paul

2018-05-19

Extracellular matrix (ECM) components modulate the interaction between pancreatic islet cells. During the islet isolation prior to transplantation as treatment for type 1 diabetes, the ECM is disrupted impacting functional graft survival. Recently, strategies for restoring ECM have shown to improve transplantation outcomes. This review discusses the current therapeutic strategies to modulate ECM components to improve islet engraftment. Approaches applied are seeding islets in ECM of decellularized organs, supplementation of specific ECM components in polymeric scaffolds or immunoisolating capsules, and stimulating islet ECM production with specific growth factors or ECM-producing cells. These strategies have shown success in improving functional islet survival. However, the same experiments show that caution should be taken as some ECM components may negatively impact islet function and engraftment. ECM restoration resulted in improved transplantation outcomes, but careful selection of beneficial ECM components and strategies is warranted.

The GPI transamidase complex subunit PbGPI16 of Plasmodium berghei is important for inducing experimental cerebral malaria.

PubMed

Liu, Qingyang; Zhao, Yan; Zheng, Li; Zhu, Xiaotong; Cui, Liwang; Cao, Yaming

2018-05-21

In animal models of experimental cerebral malaria (ECM), the glycosylphosphatidylinositols (GPIs) and GPI anchors are the major factors that induce nuclear factor kappa B (NF-κB) activation and proinflammatory responses, which contribute to malaria pathogenesis. GPIs and GPI anchors are transported to the cell surface via a process called GPI transamidation, which involves the GPI transamidase (GPI-T) complex. In this study, we showed that GPI16, one of the GPI-T subunits, is highly conserved among Plasmodium species. Genetic knockout of pbgpi16 ( Δpbgpi16 ) in the rodent malaria parasite Plasmodium berghei ANKA strain led to a significant reduction of the amount of GPIs in the membranes of merozoites as well as surface display of several GPI-anchored merozoite surface proteins. Compared with the wild-type parasites, Δpbgpi16 parasites in C57BL/6 mice caused much less NF-κB activation and elicited a substantially attenuated T helper type 1 response. As a result, Δpbgpi16 -infected mice displayed much less severe brain pathology and considerably fewer Δpbgpi16 -infected mice died from ECM. This study corroborated the GPI toxin as a significant inducer of ECM and further suggested that vaccines against parasite GPIs may be a promising strategy to limit the severity of malaria. Copyright © 2018 American Society for Microbiology.

49 CFR Appendix A to Part 395 - Electronic On-Board Recorder Performance Specifications

Code of Federal Regulations, 2011 CFR

2011-10-01

... (to home office or wireless service provider). External Sensor Issue NO_ECM no ECM data No sensory information received from vehicle's Engine Control Module (ECM). External Sensor Issue ECM_ID ECM ID number mismatch ECM identification/serial number mismatch (with preprogrammed information). 2. Communications...

Morphological plasticity of ectomycorrhizal short roots in Betula sp and Picea abies forests across climate and forest succession gradients: its role in changing environments

PubMed Central

Ostonen, Ivika; Rosenvald, Katrin; Helmisaari, Heljä-Sisko; Godbold, Douglas; Parts, Kaarin; Uri, Veiko; Lõhmus, Krista

2013-01-01

Morphological plasticity of ectomycorrhizal (EcM) short roots (known also as first and second order roots with primary development) allows trees to adjust their water and nutrient uptake to local environmental conditions. The morphological traits (MTs) of short-living EcM roots, such as specific root length (SRL) and area, root tip frequency per mass unit (RTF), root tissue density, as well as mean diameter, length, and mass of the root tips, are good indicators of acclimation. We investigated the role of EcM root morphological plasticity across the climate gradient (48–68°N) in Norway spruce (Picea abies (L.) Karst) and (53–66°N) birch (Betula pendula Roth., B. pubescens Ehrh.) forests, as well as in primary and secondary successional birch forests assuming higher plasticity of a respective root trait to reflect higher relevance of that characteristic in acclimation process. We hypothesized that although the morphological plasticity of EcM roots is subject to the abiotic and biotic environmental conditions in the changing climate; the tools to achieve the appropriate morphological acclimation are tree species-specific. Long-term (1994–2010) measurements of EcM roots morphology strongly imply that tree species have different acclimation-indicative root traits in response to changing environments. Birch EcM roots acclimated along latitude by changing mostly SRL [plasticity index (PI) = 0.60], while spruce EcM roots became adjusted by modifying RTF (PI = 0.68). Silver birch as a pioneer species must have a broader tolerance to environmental conditions across various environments; however, the mean PI of all MTs did not differ between early-successional birch and late-successional spruce. The differences between species in SRL, and RTF, diameter, and length decreased southward, toward temperate forests with more favorable growth conditions. EcM root traits reflected root-rhizosphere succession across forest succession stages. PMID:24032035

Morphological plasticity of ectomycorrhizal short roots in Betula sp and Picea abies forests across climate and forest succession gradients: its role in changing environments.

PubMed

Ostonen, Ivika; Rosenvald, Katrin; Helmisaari, Heljä-Sisko; Godbold, Douglas; Parts, Kaarin; Uri, Veiko; Lõhmus, Krista

2013-01-01

Morphological plasticity of ectomycorrhizal (EcM) short roots (known also as first and second order roots with primary development) allows trees to adjust their water and nutrient uptake to local environmental conditions. The morphological traits (MTs) of short-living EcM roots, such as specific root length (SRL) and area, root tip frequency per mass unit (RTF), root tissue density, as well as mean diameter, length, and mass of the root tips, are good indicators of acclimation. We investigated the role of EcM root morphological plasticity across the climate gradient (48-68°N) in Norway spruce (Picea abies (L.) Karst) and (53-66°N) birch (Betula pendula Roth., B. pubescens Ehrh.) forests, as well as in primary and secondary successional birch forests assuming higher plasticity of a respective root trait to reflect higher relevance of that characteristic in acclimation process. We hypothesized that although the morphological plasticity of EcM roots is subject to the abiotic and biotic environmental conditions in the changing climate; the tools to achieve the appropriate morphological acclimation are tree species-specific. Long-term (1994-2010) measurements of EcM roots morphology strongly imply that tree species have different acclimation-indicative root traits in response to changing environments. Birch EcM roots acclimated along latitude by changing mostly SRL [plasticity index (PI) = 0.60], while spruce EcM roots became adjusted by modifying RTF (PI = 0.68). Silver birch as a pioneer species must have a broader tolerance to environmental conditions across various environments; however, the mean PI of all MTs did not differ between early-successional birch and late-successional spruce. The differences between species in SRL, and RTF, diameter, and length decreased southward, toward temperate forests with more favorable growth conditions. EcM root traits reflected root-rhizosphere succession across forest succession stages.

Oligomerization-Dependent Regulation of Motility and Morphogenesis by the Collagen Xviii Nc1/Endostatin Domain

PubMed Central

Kuo, Calvin J.; LaMontagne, Kenneth R.; Garcia-Cardeña, Guillermo; Ackley, Brian D.; Kalman, Daniel; Park, Susan; Christofferson, Rolf; Kamihara, Junne; Ding, Yuan-Hua; Lo, Kin-Ming; Gillies, Stephen; Folkman, Judah; Mulligan, Richard C.; Javaherian, Kashi

2001-01-01

Collagen XVIII (c18) is a triple helical endothelial/epithelial basement membrane protein whose noncollagenous (NC)1 region trimerizes a COOH-terminal endostatin (ES) domain conserved in vertebrates, Caenorhabditis elegans and Drosophila. Here, the c18 NC1 domain functioned as a motility-inducing factor regulating the extracellular matrix (ECM)-dependent morphogenesis of endothelial and other cell types. This motogenic activity required ES domain oligomerization, was dependent on rac, cdc42, and mitogen-activated protein kinase, and exhibited functional distinction from the archetypal motogenic scatter factors hepatocyte growth factor and macrophage stimulatory protein. The motility-inducing and mitogen-activated protein kinase–stimulating activities of c18 NC1 were blocked by its physiologic cleavage product ES monomer, consistent with a proteolysis-dependent negative feedback mechanism. These data indicate that the collagen XVIII NC1 region encodes a motogen strictly requiring ES domain oligomerization and suggest a previously unsuspected mechanism for ECM regulation of motility and morphogenesis. PMID:11257123

A spectrophotometer-based diffusivity assay reveals that diffusion hindrance of small molecules in extracellular matrix gels used in 3D cultures is dominated by viscous effects.

PubMed

Galgoczy, Roland; Pastor, Isabel; Colom, Adai; Giménez, Alicia; Mas, Francesc; Alcaraz, Jordi

2014-08-01

The design of 3D culture studies remains challenging due to the limited understanding of extracellular matrix (ECM)-dependent hindered diffusion and the lack of simple diffusivity assays. To address these limitations, we set up a cost-effective diffusivity assay based on a Transwell plate and the spectrophotometer of a Microplate Reader, which are readily accessible to cell biology groups. The spectrophotometer-based assay was used to assess the apparent diffusivity D of FITC-dextrans with molecular weight (4-70kDa) spanning the physiological range of signaling factors in a panel of acellular ECM gels including Matrigel, fibrin and type I collagen. Despite their technical differences, D data exhibited ∼15% relative difference with respect to FRAP measurements. Our results revealed that diffusion hindrance of small particles is controlled by the enhanced viscosity of the ECM gel in conformance with the Stokes-Einstein equation rather than by geometrical factors. Moreover, we provided a strong rationale that the enhanced ECM viscosity is largely contributed to by unassembled ECM macromolecules. We also reported that gels with the lowest D exhibited diffusion hindrance closest to the large physiologic hindrance of brain tissue, which has a typical pore size much smaller than ECM gels. Conversely, sparse gels (≤1mg/ml), which are extensively used in 3D cultures, failed to reproduce the hindered diffusion of tissues, thereby supporting that dense (but not sparse) ECM gels are suitable tissue surrogates in terms of macromolecular transport. Finally, the consequences of reduced diffusivity in terms of optimizing the design of 3D culture experiments were addressed in detail. Copyright © 2014 Elsevier B.V. All rights reserved.

Dynamics of Cancer Cell near Collagen Fiber Chain

NASA Astrophysics Data System (ADS)

Kim, Jihan; Sun, Bo

Cell migration is an integrated process that is important in life. Migration is essential for embryonic development as well as homeostatic processes such as wound healing and immune responses. When cell migrates through connective extracellular matrix (ECM), it applies cellular traction force to ECM and senses the rigidity of their local environment. We used human breast cancer cell (MDA-MB-231) which is highly invasive and applies strong traction force to ECM. As cancer cell applies traction force to type I collage-based ECM, it deforms collagen fibers near the surface. Patterns of deforming collagen fibers are significantly different with pairs of cancer cells compared to a single cancer cell. While a pair of cancer cells within 60 um creates aligned collagen fiber chains between them permanently, a single cancer cell does not form any fiber chains. In this experiment we measured a cellular response and an interaction between a pair of cells through the chain. Finally, we analyzed correlation of directions between cancer cell migration and the collagen chain alignment.

Creation of bony microenvironment with CaP and cell-derived ECM to enhance human bone-marrow MSC behavior and delivery of BMP-2

PubMed Central

Kang, Yunqing; Kim, Sungwoo; Khademhosseini, Ali; Yang, Yunzhi

2011-01-01

Extracellular matrix (ECM) comprises a rich meshwork of proteins and proteoglycans, which not only contains biological cues for cell behavior, but is also a reservoir for binding growth factors and controlling their release. Here we aimed to create a suitable bony microenvironment with cell-derived ECM and biodegradable β-tricalcium phosphate (β-TCP). More specifically, we investigated whether the ECM produced by bone marrow-derived mesenchymal stem cells (hBMSC) on a β-TCP scaffold can bind bone morphogenetic protein-2 (BMP-2) and control its release in a sustained manner, and further examined the effect of ECM and the BMP-2 released from ECM on cell behaviors. The ECM was obtained through culturing the hBMSC on a β-TCP porous scaffold and performing decellularization and sterilization. SEM, XPS, FTIR, and immunofluorescent staining results indicated the presence of ECM on the β-TCP and the amount of ECM increased with the incubation time. BMP-2 was loaded onto the β-TCP with and without ECM by immersing the scaffolds in the BMP-2 solution. The loading and release kinetics of the BMP-2 on the β-TCP/ECM were significantly slower than those on the β-TCP. The β-TCP/ECM exhibited a sustained release profile of the BMP-2, which was also affected by the amount of ECM. This is probably because the β-TCP/ECM has different binding mechanisms with BMP-2. The β-TCP/ECM promoted cell proliferation. Furthermore, the BMP-2-loaded β-TCP/ECM stimulated reorganization of the actin cytoskeleton, increased expression of alkaline phosphatase and calcium deposition by the cells compared to those without BMP-2 loading and the β-TCP with BMP-2 loading. PMID:21632105

Quantifying the need for enhanced case management for TB patients as part of TB cohort audit in the North West of England: a descriptive study.

PubMed

Tucker, Angela; Mithoo, Jeniffer; Cleary, Paul; Woodhead, Mark; MacPherson, Peter; Wingfield, Tom; Davies, Stefanie; Wake, Carolyn; McMaster, Paddy; Bertel Squire, S

2017-11-15

Patients with TB have diverse and often challenging clinical and social needs that may hamper successful treatment outcomes. Understanding the need for additional support during treatment (enhanced case management, or ECM) is important for workforce capacity planning. North West England TB Cohort Audit (TBCA) has introduced a 4-level ECM classification system (ECM 0-3) to quantify the need for ECM in the region. This study describes the data from the first 2 years of ECM classification. Data collected between April 2013 and July 2015 were used to analyse the proportions of patients allocated to each ECM level and the prevalence of social and clinical factors indicating need for ECM. Single variable and multivariable logistic regression models were constructed to examine the association between ECM level and treatment outcome. Of 1714 notified cases 99.8% were assigned an ECM level: 31% ECM1, 19% ECM2 and 14% ECM3. The most common factors indicating need for ECM were language barriers (20.3%) and clinical complexity (16.9%). 1342/1493 (89.9%) of drug-sensitive, non-CNS cases completed treatment within 12 months. Patients in ECM2 and 3 were less likely to complete treatment at 12 months than patients in ECM0 (adjusted OR 0.47 [95% CI 0.27-0.84] and 0.23 [0.13-0.41] respectively). Use of TBCA to quantify different levels of need for ECM is feasible and has demonstrated that social and clinical complexity is common in the region. Results will inform regional workforce planning and assist development of innovative methods to improve treatment outcomes in these vulnerable groups.

Computational modeling of three-dimensional ECM-rigidity sensing to guide directed cell migration.

PubMed

Kim, Min-Cheol; Silberberg, Yaron R; Abeyaratne, Rohan; Kamm, Roger D; Asada, H Harry

2018-01-16

Filopodia have a key role in sensing both chemical and mechanical cues in surrounding extracellular matrix (ECM). However, quantitative understanding is still missing in the filopodial mechanosensing of local ECM stiffness, resulting from dynamic interactions between filopodia and the surrounding 3D ECM fibers. Here we present a method for characterizing the stiffness of ECM that is sensed by filopodia based on the theory of elasticity and discrete ECM fiber. We have applied this method to a filopodial mechanosensing model for predicting directed cell migration toward stiffer ECM. This model provides us with a distribution of force and displacement as well as their time rate of changes near the tip of a filopodium when it is bound to the surrounding ECM fibers. Aggregating these effects in each local region of 3D ECM, we express the local ECM stiffness sensed by the cell and explain polarity in the cellular durotaxis mechanism.

Spatial distributions of pericellular stiffness in natural extracellular matrices are dependent on cell-mediated proteolysis and contractility.

PubMed

Keating, M; Kurup, A; Alvarez-Elizondo, M; Levine, A J; Botvinick, E

2017-07-15

Bulk tissue stiffness has been correlated with regulation of cellular processes and conversely cells have been shown to remodel their pericellular tissue according to a complex feedback mechanism critical to development, homeostasis, and disease. However, bulk rheological methods mask the dynamics within a heterogeneous fibrous extracellular matrix (ECM) in the region proximal to a cell (pericellular region). Here, we use optical tweezers active microrheology (AMR) to probe the distribution of the complex material response function (α=α'+α″, in units of µm/nN) within a type I collagen ECM, a biomaterial commonly used in tissue engineering. We discovered cells both elastically and plastically deformed the pericellular material. α' is wildly heterogeneous, with 1/α' values spanning three orders of magnitude around a single cell. This was observed in gels having a cell-free 1/α' of approximately 0.5nN/µm. We also found that inhibition of cell contractility instantaneously softens the pericellular space and reduces stiffness heterogeneity, suggesting the system was strain hardened and not only plastically remodeled. The remaining regions of high stiffness suggest cellular remodeling of the surrounding matrix. To test this hypothesis, cells were incubated within the type I collagen gel for 24-h in a media containing a broad-spectrum matrix metalloproteinase (MMP) inhibitor. While pericellular material maintained stiffness asymmetry, stiffness magnitudes were reduced. Dual inhibition demonstrates that the combination of MMP activity and contractility is necessary to establish the pericellular stiffness landscape. This heterogeneity in stiffness suggests the distribution of pericellular stiffness, and not bulk stiffness alone, must be considered in the study of cell-ECM interactions and design of complex biomaterial scaffolds. Collagen is a fibrous extracellular matrix (ECM) protein widely used to study cell-ECM interactions. Stiffness of ECM has been shown to instruct cells, which can in turn modify their ECM, as has been shown in the study of cancer and regenerative medicine. Here we measure the stiffness of the collagen microenvironment surrounding cells and quantitatively measure the dependence of pericellular stiffness on MMP activity and cytoskeletal contractility. Competent cell-mediated stiffening results in a wildly heterogeneous micromechanical topography, with values spanning orders of magnitude around a single cell. We speculate studies must consider this notable heterogeneity generated by cells when testing theories regarding the role of ECM mechanics in health and disease. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

MT1-MMP regulates the turnover and endocytosis of extracellular matrix fibronectin

PubMed Central

Shi, Feng; Sottile, Jane

2011-01-01

The extracellular matrix (ECM) is dynamically remodeled by cells during development, normal tissue homeostasis and in a variety of disease processes. We previously showed that fibronectin is an important regulator of ECM remodeling. The deposition and/or polymerization of fibronectin into the ECM controls the deposition and stability of other ECM molecules. In addition, agents that inhibit fibronectin polymerization promote the turnover of fibronectin fibrils and enhance ECM fibronectin endocytosis and intracellular degradation. Endocytosis of ECM fibronectin is regulated by β1 integrins, including α5β1 integrin. We have examined the role of extracellular proteases in regulating ECM fibronectin turnover. Our data show that membrane type matrix metalloproteinase 1 (MT1-MMP; also known as MMP14) is a crucial regulator of fibronectin turnover. Cells lacking MT1-MMP show reduced turnover and endocytosis of ECM fibronectin. MT1-MMP regulates ECM fibronectin remodeling by promoting extracellular cleavage of fibronectin and by regulating α5β1-integrin endocytosis. Our data also show that fibronectin polymerization stabilizes fibronectin fibrils and inhibits ECM fibronectin endocytosis by inhibiting α5β1-integrin endocytosis. These data are the first to show that an ECM protein and its modifying enzyme can regulate integrin endocytosis. These data also show that integrin trafficking plays a major role in modulating ECM fibronectin remodeling. The dual dependence of ECM fibronectin turnover on extracellular proteolysis and endocytosis highlights the complex regulatory mechanisms that control ECM remodeling to ensure maintenance of proper tissue function. PMID:22159414

Measurement of sigma(e+e- -->psi(3770)-->hadrons) at Ec.m.=3773 MeV.

PubMed

Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Arms, K; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J; Shepherd, M R; Asner, D M; Edwards, K W

2006-03-10

We measure the cross section for e+e- -->psi(3770) -->hadrons at Ec.m.=3773 MeV to be (6.38+/-0.08(+0.41)(-0.30) nb using the CLEO detector at the CESR e+e- collider. The difference between this and the e+e- -->psi(3770) -->DD cross section at the same energy is found to be (-0.01+/-0.08(+0.41)(-0.30) nb. With the observed total cross section, we extract Gamma(ee)(psi(3770))=(0.204+/-0.003(+0.041)(-0.027) keV. Uncertainties shown are statistical and systematic, respectively.

Generation of a Close-to-Native In Vitro System to Study Lung Cells-Extracellular Matrix Crosstalk.

PubMed

Garlíková, Zuzana; Silva, Ana Catarina; Rabata, Anas; Potěšil, David; Ihnatová, Ivana; Dumková, Jana; Koledová, Zuzana; Zdráhal, Zbyněk; Vinarský, Vladimír; Hampl, Aleš; Pinto-do-Ó, Perpétua; Nascimento, Diana Santos

2018-01-01

Extracellular matrix (ECM) is an essential component of the tissue microenvironment, actively shaping cellular behavior. In vitro culture systems are often poor in ECM constituents, thus not allowing for naturally occurring cell-ECM interactions. This study reports on a straightforward and efficient method for the generation of ECM scaffolds from lung tissue and its subsequent in vitro application using primary lung cells. Mouse lung tissue was subjected to decellularization with 0.2% sodium dodecyl sulfate, hypotonic solutions, and DNase. Resultant ECM scaffolds were devoid of cells and DNA, whereas lung ECM architecture of alveolar region and blood and airway networks were preserved. Scaffolds were predominantly composed of core ECM and ECM-associated proteins such as collagens I-IV, nephronectin, heparan sulfate proteoglycan core protein, and lysyl oxidase homolog 1, among others. When homogenized and applied as coating substrate, ECM supported the attachment of lung fibroblasts (LFs) in a dose-dependent manner. After ECM characterization and biocompatibility tests, a novel in vitro platform for three-dimensional (3D) matrix repopulation that permits live imaging of cell-ECM interactions was established. Using this system, LFs colonized the ECM scaffolds, displaying a close-to-native morphology in intimate interaction with the ECM fibers, and showed nuclear translocation of the mechanosensor yes-associated protein (YAP), when compared with cells cultured in two dimensions. In conclusion, we developed a 3D-like culture system, by combining an efficient decellularization method with a live-imaging culture platform, to replicate in vitro native lung cell-ECM crosstalk. This is a valuable system that can be easily applied to other organs for ECM-related drug screening, disease modeling, and basic mechanistic studies.

Towards integrating extracellular matrix and immunological pathways.

PubMed

Boyd, David F; Thomas, Paul G

2017-10-01

The extracellular matrix (ECM) is a complex and dynamic structure made up of an estimated 300 different proteins. The ECM is also a rich source of cytokines and growth factors in addition to numerous bioactive ECM degradation products that influence cell migration, proliferation, and differentiation. The ECM is constantly being remodeled during homeostasis and in a wide range of pathological contexts. Changes in the ECM modulate immune responses, which in turn regulate repair and regeneration of tissues. Here, we review the many components of the ECM, enzymes involved in ECM remodeling, and the signals that feed into immunological pathways in the context of a dynamic ECM. We highlight studies that have taken an integrative approach to studying immune responses in the context of the ECM and studies that use novel proteomic strategies. Finally, we discuss research challenges relevant to the integration of immune and ECM networks and propose experimental and translational approaches to resolve these issues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fibrosis of extracellular matrix is related to the duration of the disease but is unrelated to the dynamics of collagen metabolism in dilated cardiomyopathy.

PubMed

Rubiś, Paweł; Wiśniowska-Śmialek, Sylwia; Wypasek, Ewa; Biernacka-Fijalkowska, Barbara; Rudnicka-Sosin, Lucyna; Dziewiecka, Ewa; Faltyn, Patrycja; Khachatryan, Lusine; Karabinowska, Aleksandra; Kozanecki, Artur; Tomkiewicz-Pająk, Lidia; Podolec, Piotr

2016-12-01

Fibrosis of extracellular matrix (ECM) in dilated cardiomyopathy (DCM) corresponds to the myocardial over-production of various types of collagens. However, mechanism of this process is poorly understood. To investigate whether enhanced metabolism of ECM occur in DCM. Seventy consecutive DCM patients (pts) (48 ± 12.1 years, EF 24.4 ± 7.4 %) and 20 healthy volunteers were studied. Based on symptoms duration, pts were divided into new-onset (n = 35, 6 months) and chronic DCM (n = 35, >6 months). Markers of collagen type I and III synthesis-procollagen type I carboxy- and amino-terminal peptides (PICP and PINP) and procollagen type III carboxy- and amino-terminal peptides (PIIICP and PIIINP), collagen 1 (col-1), ECM metabolism controlling factors-tumor growth factor beta-1 (TGF1-β), connective tissue growth factor (CTGF), and ECM degradation enzymes-matrix metalloproteinases (MMP-2, MMP-9) and their tissue inhibitor (TIMP-1) were measured in serum. All pts underwent right ventricular endomyocardial biopsy to study ECM fibrosis. The presence of fibrosis was detected in 24 (34.3 %) pts and was more prevalent in chronic DCM [17 (48.6 %) vs. 7 (20 %), p < 0.01]. The levels of PIIINP [4.41 (2.17-6.08) vs. 3.32 (1.69-5.02) ng/ml, p < 0.001], CTGF [3.82 (0.48-23.87) vs. 2.37 (0.51-25.32) ng/ml, p < 0.01], MMP-2 [6.06 (2.72-14.8) vs. 4.43 (2.27-7.4) ng/ml, p < 0.001], MMP-9 [1.98 (0.28-9.25) vs. 1.01 (0.29-3.59) ng/ml, p < 0.002)], and TIMP-1 [15.29 (1.8-36.17) vs. 2.61 (1.65-24.09) ng/ml, p < 0.004] were significantly higher in DCM, whereas levels of col-1 [57.7 (23.1-233.4) vs. 159.4 (31.2-512.9) pg/ml, p < 0.001] were significantly lower in DCM compared to controls. There were no differences in all measured serum markers of ECM metabolism between newonset and chronic DCM and as well as fibrosis positive and negative pts. Fibrosis was weakly correlated only with the duration of DCM (r = 0.23, p < 0.05), however, not a single serum marker of fibrosis correlated with fibrosis. Neither unadjusted nor adjusted models, constructed from serum markers of ECM metabolism, predicted the probability of myocardial fibrosis. Dynamics of ECM turnover in DCM is high, which is reflected by the increased levels CTGF and degradation enzymes. Synthesis of collagen type III prevailed over collagen type I. ECM metabolism was not different in DCM regardless of the duration of the disease and status of myocardial fibrosis. Serum markers of ECM metabolism were found not to be useful for the prediction of myocardial fibrosis in DCM.

Hydrogels Derived from Central Nervous System Extracellular Matrix

PubMed Central

Medberry, Christopher J.; Crapo, Peter M.; Siu, Bernard F.; Carruthers, Christopher A.; Wolf, Matthew T.; Nagarkar, Shailesh P.; Agrawal, Vineet; Jones, Kristen E.; Kelly, Jeremy; Johnson, Scott A.; Velankar, Sachin S.; Watkins, Simon C.; Modo, Michel

2012-01-01

Biologic scaffolds composed of extracellular matrix (ECM) are commonly used repair devices in preclinical and clinical settings; however the use of these scaffolds for peripheral and central nervous system (CNS) repair has been limited. Biologic scaffolds developed from brain and spinal cord tissue have recently been described, yet the conformation of the harvested ECM limits therapeutic utility. An injectable CNS-ECM derived hydrogel capable of in vivo polymerization and conformation to irregular lesion geometries may aid in tissue reconstruction efforts following complex neurologic trauma. The objectives of the present study were to develop hydrogel forms of brain and spinal cord ECM and compare the resulting biochemical composition, mechanical properties, and neurotrophic potential of a brain derived cell line to a non-CNS-ECM hydrogel, urinary bladder matrix. Results showed distinct differences between compositions of brain ECM, spinal cord ECM, and urinary bladder matrix. The rheologic modulus of spinal cord ECM hydrogel was greater than that of brain ECM and urinary bladder matrix. All ECMs increased the number of cells expressing neurites, but only brain ECM increased neurite length, suggesting a possible tissue-specific effect. All hydrogels promoted three-dimensional uni- or bi-polar neurite outgrowth following 7 days in culture. These results suggest that CNS-ECM hydrogels may provide supportive scaffolding to promote in vivo axonal repair. PMID:23158935

Fabrication of porous scaffolds with decellularized cartilage matrix for tissue engineering application.

PubMed

Nasiri, Bita; Mashayekhan, Shohreh

2017-07-01

Due to the avascular nature of articular cartilage, damaged tissue has little capacity for spontaneous healing. Three-dimensional scaffolds have potential for use in tissue engineering approach for cartilage repair. In this study, bovine cartilage tissue was decellularized and chemically crosslinked hybrid chitosan/extracellular matrix (ECM) scaffolds were fabricated with different ECM weight ratios by simple freeze drying method. Various properties of chitosan/ECM scaffolds such as microstructure, mechanical strength, swelling ratio, and biodegradability rate were investigated to confirm improved structural and biological characteristics of chitosan scaffolds in the presence of ECM. The results indicated that by introducing ECM to chitosan, pore sizes in scaffolds with 1% and 2% ECM decreased and thus the mechanical properties were improved. The presence of ECM in the same scaffolds also improved the swelling ratio and biodegradation rate in the hybrid scaffolds. MTT cytotoxicity assays performed on chondrocyte cells cultured on chitosan/ECM scaffolds having various amounts of ECM showed that the greatest cell attachment belongs to the sample with intermediate ECM content (2% ECM). Overall, it can be concluded from all obtained results that the prepared scaffold with intermediate concentration of ECM could be a proper candidate for use in cartilage tissue engineering. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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

2017-10-15

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

Mitochondrial function in engineered cardiac tissues is regulated by extracellular matrix elasticity and tissue alignment.

PubMed

Lyra-Leite, Davi M; Andres, Allen M; Petersen, Andrew P; Ariyasinghe, Nethika R; Cho, Nathan; Lee, Jezell A; Gottlieb, Roberta A; McCain, Megan L

2017-10-01

Mitochondria in cardiac myocytes are critical for generating ATP to meet the high metabolic demands associated with sarcomere shortening. Distinct remodeling of mitochondrial structure and function occur in cardiac myocytes in both developmental and pathological settings. However, the factors that underlie these changes are poorly understood. Because remodeling of tissue architecture and extracellular matrix (ECM) elasticity are also hallmarks of ventricular development and disease, we hypothesize that these environmental factors regulate mitochondrial function in cardiac myocytes. To test this, we developed a new procedure to transfer tunable polydimethylsiloxane disks microcontact-printed with fibronectin into cell culture microplates. We cultured Sprague-Dawley neonatal rat ventricular myocytes within the wells, which consistently formed tissues following the printed fibronectin, and measured oxygen consumption rate using a Seahorse extracellular flux analyzer. Our data indicate that parameters associated with baseline metabolism are predominantly regulated by ECM elasticity, whereas the ability of tissues to adapt to metabolic stress is regulated by both ECM elasticity and tissue alignment. Furthermore, bioenergetic health index, which reflects both the positive and negative aspects of oxygen consumption, was highest in aligned tissues on the most rigid substrate, suggesting that overall mitochondrial function is regulated by both ECM elasticity and tissue alignment. Our results demonstrate that mitochondrial function is regulated by both ECM elasticity and myofibril architecture in cardiac myocytes. This provides novel insight into how extracellular cues impact mitochondrial function in the context of cardiac development and disease. NEW & NOTEWORTHY A new methodology has been developed to measure O 2 consumption rates in engineered cardiac tissues with independent control over tissue alignment and matrix elasticity. This led to the findings that matrix elasticity regulates basal mitochondrial function, whereas both matrix elasticity and tissue alignment regulate mitochondrial stress responses. Copyright © 2017 the American Physiological Society.

7Be and hydrological model for more efficient implementation of erosion control measure

NASA Astrophysics Data System (ADS)

Al-Barri, Bashar; Bode, Samuel; Blake, William; Ryken, Nick; Cornelis, Wim; Boeckx, Pascal

2014-05-01

Increased concern about the on-site and off-site impacts of soil erosion in agricultural and forested areas has endorsed interest in innovative methods to assess in an unbiased way spatial and temporal soil erosion rates and redistribution patterns. Hence, interest in precisely estimating the magnitude of the problem and therefore applying erosion control measures (ECM) more efficiently. The latest generation of physically-based hydrological models, which fully couple overland flow and subsurface flow in three dimensions, permit implementing ECM in small and large scales more effectively if coupled with a sediment transport algorithm. While many studies focused on integrating empirical or numerical models based on traditional erosion budget measurements into 3D hydrological models, few studies evaluated the efficiency of ECM on watershed scale and very little attention is given to the potentials of environmental Fallout Radio-Nuclides (FRNs) in such applications. The use of FRN tracer 7Be in soil erosion/deposition research proved to overcome many (if not all) of the problems associated with the conventional approaches providing reliable data for efficient land use management. This poster will underline the pros and cones of using conventional methods and 7Be tracers to evaluate the efficiency of coconuts dams installed as ECM in experimental field in Belgium. It will also outline the potentials of 7Be in providing valuable inputs for evolving the numerical sediment transport algorithm needed for the hydrological model on field scale leading to assess the possibility of using this short-lived tracer as a validation tool for the upgraded hydrological model on watershed scale in further steps. Keywords: FRN, erosion control measures, hydrological modes

Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems

NASA Technical Reports Server (NTRS)

Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1994-01-01

Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

A feedback mechanism converts individual cell features into a supracellular ECM structure in Drosophila trachea

PubMed Central

Öztürk-Çolak, Arzu; Moussian, Bernard; Araújo, Sofia J; Casanova, Jordi

2016-01-01

The extracellular matrix (ECM), a structure contributed to and commonly shared by many cells in an organism, plays an active role during morphogenesis. Here, we used the Drosophila tracheal system to study the complex relationship between the ECM and epithelial cells during development. We show that there is an active feedback mechanism between the apical ECM (aECM) and the apical F-actin in tracheal cells. Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM. Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions. Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation. DOI: http://dx.doi.org/10.7554/eLife.09373.001 PMID:26836303

Recruitment of dental pulp cells by dentine and pulp extracellular matrix components.

PubMed

Smith, J G; Smith, A J; Shelton, R M; Cooper, P R

2012-11-01

The present study aimed to determine whether dentine tissue and preparations of extracellular matrix (ECM) from pulp (pECM) and dentine (dECM), and breakdown products, influenced pulp cell migration. Chemotaxis transwell and agarose spot assays demonstrated that both dentine and pulp ECM molecules acted as chemoattractants for primary pulp cells. Chemoattractant activities of dECM and pECM were enhanced when subjected to acid and enzymatic breakdown, respectively. This enhanced activity following physiologically relevant breakdown may be pertinent to the disease environment. Pulp cell migration in response to dental ECMs was dependent on an active rho pathway. Recruited cells exhibited increased stem cell marker expression indicating that dental ECMs and their breakdown products selectively attract progenitor cells that contribute to repair processes. In conclusion, combined these results indicate that ECM molecules contribute to cell recruitment necessary for regeneration of the dentine-pulp complex after injury. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantitative inhibition of soil C and N cycling by ectomycorrhizal fungi under field condition

NASA Astrophysics Data System (ADS)

Averill, C.; Hawkes, C.

2014-12-01

Ectomycorrhizal (ECM) ecosystems store more carbon than non-ectomycorrhizal ecosystems at global scale. Recent theoretical and empirical work suggests the presence of ECM fungi allows plants to compete directly with decomposers for soil nitrogen (N) via exo-enzyme synthesis. Experimental ECM exclusion often results in a release from competition of saprotrophic decomposers, allowing for increased C-degrading enzyme production, increased microbial biomass, and eventually declines in soil C stocks. Our knowledge of this phenomenon is limited, however, to the presence or absence of ECM fungi. It remains unknown if competitive repression of saprotrophic microbes and soil C cycling by ECM fungi varies with ECM abundance. This is particularly relevant to global change experiments when manipulations alter plant C allocation to ECM symbionts. To test if variation in ECM abundance alters the competitive inhibition of saprotrophic soil microbes (quantitative inhibition) we established experimental ECM exclusion treatments along an ECM abundance gradient. We dug trenches to experimentally exclude ECM fungi, allowing us to test for competitive release of soil saprotrophs from competition. To control for disturbance we placed in-growth bags both inside and outside of trenches. Consistent with the quantitative inhibition hypothesis, sites with more ECM fungi had significantly less microbial biomass per unit soil C and lower rates of N mineralization. Consistent with a release from competition, C-degrading enzyme activities were higher and gross proteolytic rates were lower per unit microbial biomass inside compared to outside trenches. We interpret this to reflect increased microbial investment in C-acquisition and decreased investment in N-acquisition in the absence of ECM fungi. Furthermore, the increase in C-degrading enzymes per unit microbial biomass was significantly greater in sites with the most abundant ECM fungi. Based on these results, ECM-saprotroph competition does appear to slow soil C cycling and the effect is quantitative. Soil C cycling is at least partly controlled by interactions between ECM fungi and soil saprotrophs. Environmental change that alters ECM abundance may thus alter soil C stocks by ameliorating or exacerbating plant-decomposer competition for nitrogen.

Ectomycorrhizal Fungal Communities in Urban Parks Are Similar to Those in Natural Forests but Shaped by Vegetation and Park Age

PubMed Central

Liu, Xinxin; Kotze, D. Johan; Jumpponen, Ari; Francini, Gaia; Setälä, Heikki

2017-01-01

ABSTRACT Ectomycorrhizal (ECM) fungi are important mutualists for the growth and health of most boreal trees. Forest age and its host species composition can impact the composition of ECM fungal communities. Although plentiful empirical data exist for forested environments, the effects of established vegetation and its successional trajectories on ECM fungi in urban greenspaces remain poorly understood. We analyzed ECM fungi in 5 control forests and 41 urban parks of two plant functional groups (conifer and broadleaf trees) and in three age categories (10, ∼50, and >100 years old) in southern Finland. Our results show that although ECM fungal richness was marginally greater in forests than in urban parks, urban parks still hosted rich and diverse ECM fungal communities. ECM fungal community composition differed between the two habitats but was driven by taxon rank order reordering, as key ECM fungal taxa remained largely the same. In parks, the ECM communities differed between conifer and broadleaf trees. The successional trajectories of ECM fungi, as inferred in relation to the time since park construction, differed among the conifers and broadleaf trees: the ECM fungal communities changed over time under the conifers, whereas communities under broadleaf trees provided no evidence for such age-related effects. Our data show that plant-ECM fungus interactions in urban parks, in spite of being constructed environments, are surprisingly similar in richness to those in natural forests. This suggests that the presence of host trees, rather than soil characteristics or even disturbance regime of the system, determine ECM fungal community structure and diversity. IMPORTANCE In urban environments, soil and trees improve environmental quality and provide essential ecosystem services. ECM fungi enhance plant growth and performance, increasing plant nutrient acquisition and protecting plants against toxic compounds. Recent evidence indicates that soil-inhabiting fungal communities, including ECM and saprotrophic fungi, in urban parks are affected by plant functional type and park age. However, ECM fungal diversity and its responses to urban stress, plant functional type, or park age remain unknown. The significance of our study is in identifying, in greater detail, the responses of ECM fungi in the rhizospheres of conifer and broadleaf trees in urban parks. This will greatly enhance our knowledge of ECM fungal communities under urban stresses, and the findings can be utilized by urban planners to improve urban ecosystem services. PMID:28970220

A strategy for tissue self-organization that is robust to cellular heterogeneity and plasticity.

PubMed

Cerchiari, Alec E; Garbe, James C; Jee, Noel Y; Todhunter, Michael E; Broaders, Kyle E; Peehl, Donna M; Desai, Tejal A; LaBarge, Mark A; Thomson, Matthew; Gartner, Zev J

2015-02-17

Developing tissues contain motile populations of cells that can self-organize into spatially ordered tissues based on differences in their interfacial surface energies. However, it is unclear how self-organization by this mechanism remains robust when interfacial energies become heterogeneous in either time or space. The ducts and acini of the human mammary gland are prototypical heterogeneous and dynamic tissues comprising two concentrically arranged cell types. To investigate the consequences of cellular heterogeneity and plasticity on cell positioning in the mammary gland, we reconstituted its self-organization from aggregates of primary cells in vitro. We find that self-organization is dominated by the interfacial energy of the tissue-ECM boundary, rather than by differential homo- and heterotypic energies of cell-cell interaction. Surprisingly, interactions with the tissue-ECM boundary are binary, in that only one cell type interacts appreciably with the boundary. Using mathematical modeling and cell-type-specific knockdown of key regulators of cell-cell cohesion, we show that this strategy of self-organization is robust to severe perturbations affecting cell-cell contact formation. We also find that this mechanism of self-organization is conserved in the human prostate. Therefore, a binary interfacial interaction with the tissue boundary provides a flexible and generalizable strategy for forming and maintaining the structure of two-component tissues that exhibit abundant heterogeneity and plasticity. Our model also predicts that mutations affecting binary cell-ECM interactions are catastrophic and could contribute to loss of tissue architecture in diseases such as breast cancer.

The extracellular matrix protein laminin-10 promotes blood-brain barrier repair after hypoxia and inflammation in vitro.

PubMed

Kangwantas, Korakoch; Pinteaux, Emmanuel; Penny, Jeffrey

2016-02-01

The blood-brain barrier (BBB) of the central nervous system (CNS) is essential for normal brain function. However, the loss of BBB integrity that occurs after ischaemic injury is associated with extracellular matrix (ECM) remodelling and inflammation, and contributes to poor outcome. ECM remodelling also contributes to BBB repair after injury, but the precise mechanisms and contribution of specific ECM molecules involved are unknown. Here, we investigated the mechanisms by which hypoxia and inflammation trigger loss of BBB integrity and tested the hypothesis ECM changes could contribute to BBB repair in vitro. We used an in vitro model of the BBB, composed of primary rat brain endothelial cells grown on collagen (Col) I-, Col IV-, fibronectin (FN)-, laminin (LM) 8-, or LM10-coated tissue culture plates, either as a single monolayer culture or on Transwell® inserts above mixed glial cell cultures. Cultures were exposed to oxygen-glucose deprivation (OGD) and/or reoxygenation, in the absence or the presence of recombinant interleukin-1β (IL-1β). Cell adhesion to ECM molecules was assessed by cell attachment and cell spreading assays. BBB dysfunction was assessed by immunocytochemistry for tight junction proteins occludin and zona occludens-1 (ZO-1) and measurement of trans-endothelial electrical resistance (TEER). Change in endothelial expression of ECM molecules was assessed by semi-quantitative RT-PCR. OGD and/or IL-1 induce dramatic changes associated with loss of BBB integrity, including cytoplasmic relocalisation of membrane-associated tight junction proteins occludin and ZO-1, cell swelling, and decreased TEER. OGD and IL-1 also induced gene expression of key ECM molecules associated with the BBB, including FN, Col IV, LM 8, and LM10. Importantly, we found that LM10, but not FN, Col IV, nor LM8, plays a key role in maintenance of BBB integrity and reversed most of the key hallmarks of BBB dysfunction induced by IL-1. Our data unravel new mechanisms of BBB dysfunction induced by hypoxia and inflammation and identify LM10 as a key ECM molecule involved in BBB repair after hypoxic injury and inflammation.

A Human Amnion-Derived Extracellular Matrix-Coated Cell-Free Scaffold for Cartilage Repair: In Vitro and In Vivo Studies.

PubMed

Nogami, Makiko; Kimura, Tomoatsu; Seki, Shoji; Matsui, Yoshito; Yoshida, Toshiko; Koike-Soko, Chika; Okabe, Motonori; Motomura, Hiraku; Gejo, Ryuichi; Nikaido, Toshio

2016-04-01

Extracellular matrix (ECM) derived from human amniotic mesenchymal cells (HAMs) has various biological activities. In this study, we developed a novel HAM-derived ECM-coated polylactic-co-glycolic acid (ECM-PLGA) scaffold, examined its property on mesenchymal cells, and investigated its potential as a cell-free scaffold for cartilage repair. ECM-PLGA scaffolds were developed by inoculating HAM on a PLGA. After decellularization by irradiation, accumulated ECM was examined. Exogenous cell growth and differentiation of rat mesenchymal stem cells (MSCs) on the ECM-PLGA were analyzed in vitro by cell attachment/proliferation assay and reverse transcription-polymerase chain reaction. The cell-free ECM-PLGA scaffolds were implanted into osteochondral defects in the trochlear groove of rat knees. After 4, 12, or 24 weeks, the animals were sacrificed and the harvested tissues were examined histologically. The ECM-PLGA contained ECM that mimicked natural amniotic stroma that contains type I collagen, fibronectin, hyaluronic acid, and chondroitin sulfates. The ECM-PLGA showed excellent properties of cell attachment and proliferation. MSCs inoculated on the ECM-PLGA scaffold showed accelerated type II collagen mRNA expression after 3 weeks in culture. The ECM-PLGA implanted into an osteochondral defect in rat knees induced gradual tissue regeneration and resulted in hyaline cartilage repair, which was better than that in the empty control group. These in vitro and in vivo experiments show that the cell-free scaffold composed of HAM-derived ECM and PLGA provides a favorable growth environment for MSCs and facilitates the cartilage repair process. The ECM-PLGA may become a "ready-made" biomaterial for cartilage repair therapy.

40 CFR 1065.915 - PEMS instruments.

Code of Federal Regulations, 2011 CFR

2011-07-01

....5% of max. Engine torque estimator, BSFC (This is a signal from an engine's ECM) T or BSFC 1 s 1 Hz... PEMS. (d) ECM signals. You may use signals from the engine's electronic control module (ECM) in place...) Recording ECM signals. If your ECM updates a broadcast signal more or less frequently than 1 Hz, process...

Influence of surfaces modified with biomimetic extracellular matrices on adhesion and proliferation of mesenchymal stem cells and osteosarcoma cells.

PubMed

Cai, Rong; Kawazoe, Naoki; Chen, Guoping

2015-02-01

Preparation of surfaces modified with biomimetic extracellular matrices (ECMs) is important for investigation of the interaction between ECMs and cells. In the present study, surfaces modified with ECMs from normal somatic cells, stem cells and tumor cells were prepared by cell culture method. The ECMs derived from bone marrow-derived mesenchymal stem cells (MSCs), dermal fibroblasts (FBs), osteoblasts (OBs) and MG63 osteosarcoma cells were deposited on the surfaces of cell-culture polystyrene plates (TCPS). The ECMs from different cell types had different compositions. The effects of the ECM-deposited surfaces on the adhesion, spreading and proliferation of MSCs and MG63 human osteosarcoma cells were dependent on the type of both ECMs and cells. The surfaces deposited with ECMs from MSCs, FBs and OBs promoted cell adhesion more strongly than surfaces deposited with ECMs from MG63 cells and TCPS. Compared to TCPS, the ECM-deposited surfaces promoted proliferation of MSCs while they inhibited the proliferation of MG63 cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Incorporation of Tenascin-C into the Extracellular Matrix by Periostin Underlies an Extracellular Meshwork Architecture*

PubMed Central

Kii, Isao; Nishiyama, Takashi; Li, Minqi; Matsumoto, Ken-ichi; Saito, Mitsuru; Amizuka, Norio; Kudo, Akira

2010-01-01

Extracellular matrix (ECM) underlies a complicated multicellular architecture that is subjected to significant forces from mechanical environment. Although various components of the ECM have been enumerated, mechanisms that evolve the sophisticated ECM architecture remain to be addressed. Here we show that periostin, a matricellular protein, promotes incorporation of tenascin-C into the ECM and organizes a meshwork architecture of the ECM. We found that both periostin null mice and tenascin-C null mice exhibited a similar phenotype, confined tibial periostitis, which possibly corresponds to medial tibial stress syndrome in human sports injuries. Periostin possessed adjacent domains that bind to tenascin-C and the other ECM protein: fibronectin and type I collagen, respectively. These adjacent domains functioned as a bridge between tenascin-C and the ECM, which increased deposition of tenascin-C on the ECM. The deposition of hexabrachions of tenascin-C may stabilize bifurcations of the ECM fibrils, which is integrated into the extracellular meshwork architecture. This study suggests a role for periostin in adaptation of the ECM architecture in the mechanical environment. PMID:19887451

Incorporation of tenascin-C into the extracellular matrix by periostin underlies an extracellular meshwork architecture.

PubMed

Kii, Isao; Nishiyama, Takashi; Li, Minqi; Matsumoto, Ken-Ichi; Saito, Mitsuru; Amizuka, Norio; Kudo, Akira

2010-01-15

Extracellular matrix (ECM) underlies a complicated multicellular architecture that is subjected to significant forces from mechanical environment. Although various components of the ECM have been enumerated, mechanisms that evolve the sophisticated ECM architecture remain to be addressed. Here we show that periostin, a matricellular protein, promotes incorporation of tenascin-C into the ECM and organizes a meshwork architecture of the ECM. We found that both periostin null mice and tenascin-C null mice exhibited a similar phenotype, confined tibial periostitis, which possibly corresponds to medial tibial stress syndrome in human sports injuries. Periostin possessed adjacent domains that bind to tenascin-C and the other ECM protein: fibronectin and type I collagen, respectively. These adjacent domains functioned as a bridge between tenascin-C and the ECM, which increased deposition of tenascin-C on the ECM. The deposition of hexabrachions of tenascin-C may stabilize bifurcations of the ECM fibrils, which is integrated into the extracellular meshwork architecture. This study suggests a role for periostin in adaptation of the ECM architecture in the mechanical environment.

Linearized texture of three-dimensional extracellular matrix is mandatory for bladder cancer cell invasion.

PubMed

Alfano, Massimo; Nebuloni, Manuela; Allevi, Raffaele; Zerbi, Pietro; Longhi, Erika; Lucianò, Roberta; Locatelli, Irene; Pecoraro, Angela; Indrieri, Marco; Speziali, Chantal; Doglioni, Claudio; Milani, Paolo; Montorsi, Francesco; Salonia, Andrea

2016-10-25

In the fields of biomaterials and tissue engineering simulating the native microenvironment is of utmost importance. As a major component of the microenvironment, the extracellular matrix (ECM) contributes to tissue homeostasis, whereas modifications of native features are associated with pathological conditions. Furthermore, three-dimensional (3D) geometry is an important feature of synthetic scaffolds favoring cell stemness, maintenance and differentiation. We analyzed the 3D structure, geometrical measurements and anisotropy of the ECM isolated from (i) human bladder mucosa (basal lamina and lamina propria) and muscularis propria; and, (ii) bladder carcinoma (BC). Next, binding and invasion of bladder metastatic cell line was observed on synthetic scaffold recapitulating anisotropy of tumoral ECM, but not on scaffold with disorganized texture typical of non-neoplastic lamina propria. This study provided information regarding the ultrastructure and geometry of healthy human bladder and BC ECMs. Likewise, using synthetic scaffolds we identified linearization of the texture as a mandatory feature for BC cell invasion. Integrating microstructure and geometry with biochemical and mechanical factors could support the development of an innovative synthetic bladder substitute or a tumoral scaffold predictive of chemotherapy outcomes.

Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension

NASA Technical Reports Server (NTRS)

Wang, N.; Ingber, D. E.

1994-01-01

We have investigated how extracellular matrix (ECM) alters the mechanical properties of the cytoskeleton (CSK). Mechanical stresses were applied to integrin receptors on the apical surfaces of adherent endothelial cells using RGD-coated ferromagnetic microbeads (5.5-microns diameter) in conjunction with a magnetic twisting device. Increasing the number of basal cell-ECM contacts by raising the fibronectin (FN) coating density from 10 to 500 ng/cm2 promoted cell spreading by fivefold and increased CSK stiffness, apparent viscosity, and permanent deformation all by more than twofold, as measured in response to maximal stress (40 dyne/cm2). When the applied stress was increased from 7 to 40 dyne/cm2, the stiffness and apparent viscosity of the CSK increased in parallel, although cell shape, ECM contacts, nor permanent deformation was altered. Application of the same stresses over a lower number ECM contacts using smaller beads (1.4-microns diameter) resulted in decreased CSK stiffness and apparent viscosity, confirming that this technique probes into the depth of the CSK and not just the cortical membrane. When magnetic measurements were carried out using cells whose membranes were disrupted and ATP stores depleted using saponin, CSK stiffness and apparent viscosity were found to rise by approximately 20%, whereas permanent deformation decreased by more than half. Addition of ATP (250 microM) under conditions that promote CSK tension generation in membrane-permeabilized cells resulted in decreases in CSK stiffness and apparent viscosity that could be detected within 2 min after ATP addition, before any measurable change in cell size.(ABSTRACT TRUNCATED AT 250 WORDS).

Remodelling the extracellular matrix in development and disease

PubMed Central

Bonnans, Caroline; Chou, Jonathan; Werb, Zena

2015-01-01

The extracellular matrix (ECM) is a highly dynamic structure that is present in all tissues and continuously undergoes controlled remodelling. This process involves quantitative and qualitative changes in the ECM, mediated by specific enzymes that are responsible for ECM degradation, such as metalloproteinases. The ECM interacts with cells to regulate diverse functions, including proliferation, migration and differentiation. ECM remodelling is crucial for regulating the morphogenesis of the intestine and lungs, as well as of the mammary and submandibular glands. Dysregulation of ECM composition, structure, stiffness and abundance contributes to several pathological conditions, such as fibrosis and invasive cancer. A better understanding of how the ECM regulates organ structure and function and of how ECM remodelling affects disease progression will contribute to the development of new therapeutics. PMID:25415508

A new conceptual framework for unifying the heterogeneity of plant-microbe interactions in forests by linking belowground measurements with large-scale modeling and remote sensing

NASA Astrophysics Data System (ADS)

Brzostek, E. R.; Phillips, R.; Fisher, J. B.

2015-12-01

Recognition of the importance of rhizosphere interactions to ecosystem processes has led to efforts to integrate these dynamics into a conceptual framework that can be tested, refined and applied across spatial scales. A new view suggests that a plant's mycorrhizal association represents a "trait integrator" for a suite of aboveground and belowground functional traits involved in coupling C-nutrient cycles, since nearly all plants associate with a single type of mycorrhizal fungi. The MANE framework predicts that tree species that associate with arbuscular mycorrhizal (AM) fungi differ from trees that associate with ectomycorrhizal (ECM) fungi in a suite of functional traits, and that such differences contribute to unique "biogeochemical syndromes" in forests with varying abundances of AM- and ECM-associated trees. To date, we have found that relative to AM trees, the leaf litter of ECM trees decomposes nearly 50% more slowly; as such, the nutrient economy of ECM-dominated stands is driven by organic forms of N and P whereas the nutrient economy of AM-dominated stands in driven by inorganic forms of N and P. Moreover, differences in the nutrient economies between AM- and ECM-dominated stands can affect the carbon (C) cost of nutrient acquisition. For example, while ECM trees allocate 2-3-fold more C to fine roots and mycorrhizal fungi, this greater investment results in the enhanced activity of enzymes that mobilize nitrogen (N) and phosphorus (P) from soil organic matter, and ultimately the greater uptake of nutrients by plants. However, this enhanced uptake by ECM trees comes at a cost to soil organic C, which declines as a function of root-accelerated N mineralization. By incorporating these dynamics into a coupled nutrient acquisition-microbial decomposition model, and scaling these processes following development of a map of mycorrhizal associations, we are now quantifying how belowground processes shape ecosystem sensitivity to global changes (e.g., rising CO2, warming) at regional- and continental-scales.

The regulation of growth and metabolism of kidney stem cells with regional specificity using extracellular matrix derived from kidney.

PubMed

O'Neill, John D; Freytes, Donald O; Anandappa, Annabelle J; Oliver, Juan A; Vunjak-Novakovic, Gordana V

2013-12-01

Native extracellular matrix (ECM) that is secreted and maintained by resident cells is of great interest for cell culture and cell delivery. We hypothesized that specialized bioengineered niches for stem cells can be established using ECM-derived scaffolding materials. Kidney was selected as a model system because of the high regional diversification of renal tissue matrix. By preparing the ECM from three specialized regions of the kidney (cortex, medulla, and papilla; whole kidney, heart, and bladder as controls) in three forms: (i) intact sheets of decellularized ECM, (ii) ECM hydrogels, and (iii) solubilized ECM, we investigated how the structure and composition of ECM affect the function of kidney stem cells (with mesenchymal stem cells, MSCs, as controls). All three forms of the ECM regulated KSC function, with differential structural and compositional effects. KSCs cultured on papilla ECM consistently displayed lower proliferation, higher metabolic activity, and differences in cell morphology, alignment, and structure formation as compared to KSCs on cortex and medulla ECM, effects not observed in corresponding MSC cultures. These data suggest that tissue- and region-specific ECM can provide an effective substrate for in vitro studies of therapeutic stem cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

An investigation of the Eigenvalue Calibration Method (ECM) using GASP for non-imaging and imaging detectors

NASA Astrophysics Data System (ADS)

Kyne, Gillian; Lara, David; Hallinan, Gregg; Redfern, Michael; Shearer, Andrew

2016-02-01

Polarised light from astronomical targets can yield a wealth of information about their source radiation mechanisms, and about the geometry of the scattered light regions. Optical observations, of both the linear and circular polarisation components, have been impeded due to non-optimised instrumentation. The need for suitable observing conditions and the availability of luminous targets are also limiting factors. The science motivation of any instrument adds constraints to its operation such as high signal-to-noise (SNR) and detector readout speeds. These factors in particular lead to a wide range of sources that have yet to be observed. The Galway Astronomical Stokes Polarimeter (GASP) has been specifically designed to make observations of these sources. GASP uses division of amplitude polarimeter (DOAP) (Compain and Drevillon Appl. Opt. 37, 5938-5944, 1998) to measure the four components of the Stokes vector (I, Q, U and V) simultaneously, which eliminates the constraints placed upon the need for moving parts during observation, and offers a real-time complete measurement of polarisation. Results from the GASP calibration are presented in this work for both a 1D detector system, and a pixel-by-pixel analysis on a 2D detector system. Following Compain et al. (Appl. Opt. 38, 3490-3502 1999) we use the Eigenvalue Calibration Method (ECM) to measure the polarimetric limitations of the instrument for each of the two systems. Consequently, the ECM is able to compensate for systematic errors introduced by the calibration optics, and it also accounts for all optical elements of the polarimeter in the output. Initial laboratory results of the ECM are presented, using APD detectors, where errors of 0.2 % and 0.1° were measured for the degree of linear polarisation (DOLP) and polarisation angle (PA) respectively. Channel-to-channel image registration is an important aspect of 2-D polarimetry. We present our calibration results of the measured Mueller matrix of each sample, used by the ECM, when 2 Andor iXon Ultra 897 detectors were loaned to the project. A set of Zenith flat-field images were recorded during an observing campaign at the Palomar 200 inch telescope in November 2012. From these we show the polarimetric errors from the spatial polarimetry indicating both the stability and absolute accuracy of GASP.

Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

NASA Astrophysics Data System (ADS)

Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

2015-11-01

The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils.

Diversity and community structure of ectomycorrhizal fungi associated with Larix chinensis across the alpine treeline ecotone of Taibai Mountain.

PubMed

Han, Qisheng; Huang, Jian; Long, Dongfeng; Wang, Xiaobing; Liu, Jianjun

2017-07-01

Alpine treeline ecotones represent ecosystems that are vulnerable to climate change. We investigated the ectomycorrhizal (ECM) community, which has potential to stabilize alpine ecosystems. ECM communities associated with Larix chinensis were studied in four zones along a natural ecotone from a mixed forest stand over pure forest stands, the timberline, and eventually, the treeline (3050-3450 m) in Tabai Mountain, China. Sixty operational taxonomic units (OTUs) of ECM fungi were identified by sequencing the rDNA internal transcribed spacer of ECM tips. The richness of ECM species increased with elevation. The soil C/N ratio was the most important factor explaining ECM species richness. The treeline zone harbored some unique ECM fungi whereas no unique genera were observed in the timberline and pure forest zone. Elevation and topography were equally important factors influencing ECM communities in the alpine region. We suggest that a higher diversity of the ECM fungal community associated with L. chinensis in the treeline zone could result from niche differentiation.

Extracellular matrix in lung development, homeostasis and disease

DOE PAGES

Zhou, Yong; Horowitz, Jeffrey C.; Naba, Alexandra; ...

2018-03-08

The lung's unique extracellular matrix (ECM), while providing structural support for cells, is critical in the regulation of developmental organogenesis, homeostasis and injury-repair responses. The ECM, via biochemical or biomechanical cues, regulates diverse cell functions, fate and phenotype. The composition and function of lung ECM become markedly deranged in pathological tissue remodeling. ECM-based therapeutics and bioengineering approaches represent promising novel strategies for regeneration/repair of the lung and treatment of chronic lung diseases. In this paper, we assess the current state of lung ECM biology, including fundamental advances in ECM composition, dynamics, topography, and biomechanics; the role of the ECM inmore » normal and aberrant lung development, adult lung diseases and autoimmunity; and ECM in the regulation of the stem cell niche. Finally, we identify opportunities to advance the field of lung ECM biology and provide a set recommendations for research priorities to advance knowledge that would inform novel approaches to the pathogenesis, diagnosis, and treatment of chronic lung diseases.« less

Institutional Transformation Version 2.5 Modeling and Planning.

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

Villa, Daniel; Mizner, Jack H.; Passell, Howard D.

Reducing the resource consumption and emissions of large institutions is an important step toward a sustainable future. Sandia National Laboratories' (SNL) Institutional Transformation (IX) project vision is to provide tools that enable planners to make well-informed decisions concerning sustainability, resource conservation, and emissions reduction across multiple sectors. The building sector has been the primary focus so far because it is the largest consumer of resources for SNL. The IX building module allows users to define the evolution of many buildings over time. The module has been created so that it can be generally applied to any set of DOE-2 (more » http://doe2.com ) building models that have been altered to include parameters and expressions required by energy conservation measures (ECM). Once building models have been appropriately prepared, they are checked into a Microsoft Access (r) database. Each building can be represented by many models. This enables the capability to keep a continuous record of models in the past, which are replaced with different models as changes occur to the building. In addition to this, the building module has the capability to apply climate scenarios through applying different weather files to each simulation year. Once the database has been configured, a user interface in Microsoft Excel (r) is used to create scenarios with one or more ECMs. The capability to include central utility buildings (CUBs) that service more than one building with chilled water has been developed. A utility has been created that joins multiple building models into a single model. After using the utility, several manual steps are required to complete the process. Once this CUB model has been created, the individual contributions of each building are still tracked through meters. Currently, 120 building models from SNL's New Mexico and California campuses have been created. This includes all buildings at SNL greater than 10,000 sq. ft., representing 80% of the energy consumption at SNL. SNL has been able to leverage this model to estimate energy savings potential of many competing ECMs. The results helped high level decision makers to create energy reduction goals for SNL. These resources also have multiple applications for use of the models as individual buildings. In addition to the building module, a solar module built in Powersim Studio (r) allows planners to evaluate the potential photovoltaic (PV) energy generation potential for flat plate PV, concentrating solar PV, and concentration solar thermal technologies at multiple sites across SNL's New Mexico campus. Development of the IX modeling framework was a unique collaborative effort among planners and engineers in SNL's facilities division; scientists and computer modelers in SNL's research and development division; faculty from Arizona State University; and energy modelers from Bridger and Paxton Consulting Engineers Incorporated.« less

Ectomycorrhizal Fungal Communities in Urban Parks Are Similar to Those in Natural Forests but Shaped by Vegetation and Park Age.

PubMed

Hui, Nan; Liu, Xinxin; Kotze, D Johan; Jumpponen, Ari; Francini, Gaia; Setälä, Heikki

2017-12-01

Ectomycorrhizal (ECM) fungi are important mutualists for the growth and health of most boreal trees. Forest age and its host species composition can impact the composition of ECM fungal communities. Although plentiful empirical data exist for forested environments, the effects of established vegetation and its successional trajectories on ECM fungi in urban greenspaces remain poorly understood. We analyzed ECM fungi in 5 control forests and 41 urban parks of two plant functional groups (conifer and broadleaf trees) and in three age categories (10, ∼50, and >100 years old) in southern Finland. Our results show that although ECM fungal richness was marginally greater in forests than in urban parks, urban parks still hosted rich and diverse ECM fungal communities. ECM fungal community composition differed between the two habitats but was driven by taxon rank order reordering, as key ECM fungal taxa remained largely the same. In parks, the ECM communities differed between conifer and broadleaf trees. The successional trajectories of ECM fungi, as inferred in relation to the time since park construction, differed among the conifers and broadleaf trees: the ECM fungal communities changed over time under the conifers, whereas communities under broadleaf trees provided no evidence for such age-related effects. Our data show that plant-ECM fungus interactions in urban parks, in spite of being constructed environments, are surprisingly similar in richness to those in natural forests. This suggests that the presence of host trees, rather than soil characteristics or even disturbance regime of the system, determine ECM fungal community structure and diversity. IMPORTANCE In urban environments, soil and trees improve environmental quality and provide essential ecosystem services. ECM fungi enhance plant growth and performance, increasing plant nutrient acquisition and protecting plants against toxic compounds. Recent evidence indicates that soil-inhabiting fungal communities, including ECM and saprotrophic fungi, in urban parks are affected by plant functional type and park age. However, ECM fungal diversity and its responses to urban stress, plant functional type, or park age remain unknown. The significance of our study is in identifying, in greater detail, the responses of ECM fungi in the rhizospheres of conifer and broadleaf trees in urban parks. This will greatly enhance our knowledge of ECM fungal communities under urban stresses, and the findings can be utilized by urban planners to improve urban ecosystem services. Copyright © 2017 American Society for Microbiology.

Asynchronous origins of ectomycorrhizal clades of Agaricales.

PubMed

Ryberg, Martin; Matheny, P Brandon

2012-05-22

The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild.

Asynchronous origins of ectomycorrhizal clades of Agaricales

PubMed Central

Ryberg, Martin; Matheny, P. Brandon

2012-01-01

The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild. PMID:22171078

A time- and matrix-dependent TGFBR3–JUND–KRT5 regulatory circuit in single breast epithelial cells and basal-like premalignancies

PubMed Central

Wang, Chun-Chao; Bajikar, Sameer S.; Jamal, Leen; Atkins, Kristen A.; Janes, Kevin A.

2014-01-01

Basal-like breast carcinoma is characterized by poor prognosis and high intratumor heterogeneity. In an immortalized basal-like breast epithelial cell line, we identified two anti-correlated gene-expression programs that arise among single extracellular matrix (ECM)-attached cells during organotypic 3D culture. The first contains multiple TGFβ-related genes including TGFBR3, whereas the second contains JUND and the basal-like marker, KRT5. TGFBR3 and JUND interconnect through four negative-feedback loops to form a circuit that exhibits spontaneous damped oscillations in 3D culture. The TGFBR3–JUND circuit appears conserved in some premalignant lesions that heterogeneously express KRT5. The circuit depends on ECM engagement, as detachment causes a rewiring that is triggered by RPS6 dephosphorylation and maintained by juxtacrine tenascin C, which is critical for intraductal colonization of basal-like breast cancer cells in vivo. Intratumor heterogeneity need not stem from partial differentiation and could instead reflect dynamic toggling of cells between expression states that are not cell autonomous. PMID:24658685

Distinct Effects of RGD-glycoproteins on Integrin-Mediated Adhesion and Osteogenic Differentiation of Human Mesenchymal Stem Cells

PubMed Central

Schwab, Elisabeth H.; Halbig, Maria; Glenske, Kristina; Wagner, Alena-Svenja; Wenisch, Sabine; Cavalcanti-Adam, Elisabetta A.

2013-01-01

The detailed interactions of mesenchymal stem cells (MSCs) with their extracellular matrix (ECM) and the resulting effects on MSC differentiation are still largely unknown. Integrins are the main mediators of cell-ECM interaction. In this study, we investigated the adhesion of human MSCs to fibronectin, vitronectin and osteopontin, three ECM glycoproteins which contain an integrin-binding sequence, the RGD motif. We then assayed MSCs for their osteogenic commitment in the presence of the different ECM proteins. As early as 2 hours after seeding, human MSCs displayed increased adhesion when plated on fibronectin, whereas no significant difference was observed when adhering either to vitronectin or osteopontin. Over a 10-day observation period, cell proliferation was increased when cells were cultured on fibronectin and osteopontin, albeit after 5 days in culture. The adhesive role of fibronectin was further confirmed by measurements of cell area, which was significantly increased on this type of substrate. However, integrin-mediated clusters, namely focal adhesions, were larger and more mature in MSCs adhering to vitronectin and osteopontin. Adhesion to fibronectin induced elevated expression of α5-integrin, which was further upregulated under osteogenic conditions also for vitronectin and osteopontin. In contrast, during osteogenic differentiation the expression level of β3-integrin was decreased in MSCs adhering to the different ECM proteins. When MSCs were cultured under osteogenic conditions, their commitment to the osteoblast lineage and their ability to form a mineralized matrix in vitro was increased in presence of fibronectin and osteopontin. Taken together these results indicate a distinct role of ECM proteins in regulating cell adhesion, lineage commitment and phenotype of MSCs, which is due to the modulation of the expression of specific integrin subunits during growth or osteogenic differentiation. PMID:24324361

Distinct effects of RGD-glycoproteins on Integrin-mediated adhesion and osteogenic differentiation of human mesenchymal stem cells.

PubMed

Schwab, Elisabeth H; Halbig, Maria; Glenske, Kristina; Wagner, Alena-Svenja; Wenisch, Sabine; Cavalcanti-Adam, Elisabetta A

2013-01-01

The detailed interactions of mesenchymal stem cells (MSCs) with their extracellular matrix (ECM) and the resulting effects on MSC differentiation are still largely unknown. Integrins are the main mediators of cell-ECM interaction. In this study, we investigated the adhesion of human MSCs to fibronectin, vitronectin and osteopontin, three ECM glycoproteins which contain an integrin-binding sequence, the RGD motif. We then assayed MSCs for their osteogenic commitment in the presence of the different ECM proteins. As early as 2 hours after seeding, human MSCs displayed increased adhesion when plated on fibronectin, whereas no significant difference was observed when adhering either to vitronectin or osteopontin. Over a 10-day observation period, cell proliferation was increased when cells were cultured on fibronectin and osteopontin, albeit after 5 days in culture. The adhesive role of fibronectin was further confirmed by measurements of cell area, which was significantly increased on this type of substrate. However, integrin-mediated clusters, namely focal adhesions, were larger and more mature in MSCs adhering to vitronectin and osteopontin. Adhesion to fibronectin induced elevated expression of α₅-integrin, which was further upregulated under osteogenic conditions also for vitronectin and osteopontin. In contrast, during osteogenic differentiation the expression level of β₃-integrin was decreased in MSCs adhering to the different ECM proteins. When MSCs were cultured under osteogenic conditions, their commitment to the osteoblast lineage and their ability to form a mineralized matrix in vitro was increased in presence of fibronectin and osteopontin. Taken together these results indicate a distinct role of ECM proteins in regulating cell adhesion, lineage commitment and phenotype of MSCs, which is due to the modulation of the expression of specific integrin subunits during growth or osteogenic differentiation.

Species turnover (β-diversity) in ectomycorrhizal fungi linked to NH4+ uptake capacity.

PubMed

Kranabetter, J M; Hawkins, B J; Jones, M D; Robbins, S; Dyer, T; Li, T

2015-12-01

Ectomycorrhizal (EcM) fungal communities may be shaped by both deterministic and stochastic processes, potentially influencing ecosystem development and function. We evaluated community assembly processes for EcM fungi of Pseudotsuga menziesii among 12 sites up to 400 km apart in southwest British Columbia (Canada) by investigating species turnover (β-diversity) in relation to soil nitrogen (N) availability and physical distance. We then examined functional traits for an N-related niche by quantifying net fluxes of NH4+, NO3- and protons on excised root tips from three contrasting sites using a microelectrode ion flux measurement system. EcM fungal communities were well aligned with soil N availability and pH, with no effect of site proximity (distance-decay curve) on species assemblages. Species turnover was significant (β(1/2) = 1.48) along soil N gradients, with many more Tomentella species on high N than low N soils, in contrast to Cortinarius species. Ammonium uptake was greatest in the spring on the medium and rich sites and averaged over 190 nmol/m(2)/s for Tomentella species. The lowest uptake rates of NH4+ were by nonmycorrhizal roots of axenically grown seedlings (10 nmol/m(2)/s), followed by Cortinarius species (60 nmol/m(2)/s). EcM roots from all sites displayed only marginal uptake of nitrate (8.3 nmol/m(2)/s). These results suggest NH4+ uptake capacity is an important functional trait influencing the assembly of EcM fungal communities. The diversity of EcM fungal species across the region arguably provides critical belowground adaptations to organic and inorganic N supply that are integral to temperate rainforest ecology. © 2015 John Wiley & Sons Ltd.

Extracellular Matrix Hydrogel Derived from Human Umbilical Cord as a Scaffold for Neural Tissue Repair and Its Comparison with Extracellular Matrix from Porcine Tissues.

PubMed

Kočí, Zuzana; Výborný, Karel; Dubišová, Jana; Vacková, Irena; Jäger, Aleš; Lunov, Oleg; Jiráková, Klára; Kubinová, Šárka

2017-06-01

Extracellular matrix (ECM) hydrogels prepared by tissue decellularization have been reported as natural injectable materials suitable for neural tissue repair. In this study, we prepared ECM hydrogel derived from human umbilical cord (UC) and evaluated its composition and mechanical and biological properties in comparison with the previously described ECM hydrogels derived from porcine urinary bladder (UB), brain, and spinal cord. The ECM hydrogels did not differ from each other in the concentration of collagen, while the highest content of glycosaminoglycans as well as the shortest gelation time was found for UC-ECM. The elastic modulus was then found to be the highest for UB-ECM. In spite of a different origin, topography, and composition, all ECM hydrogels similarly promoted the migration of human mesenchymal stem cells (MSCs) and differentiation of neural stem cells, as well as axonal outgrowth in vitro. However, only UC-ECM significantly improved proliferation of tissue-specific UC-derived MSCs when compared with the other ECMs. Injection of UC-ECM hydrogels into a photothrombotic cortical ischemic lesion in rats proved its in vivo gelation and infiltration with host macrophages. In summary, this study proposes UC-ECM hydrogel as an easily accessible biomaterial of human origin, which has the potential for neural as well as other soft tissue reconstruction.

Testing the link between community structure and function for ectomycorrhizal fungi involved in a global tripartite symbiosis.

PubMed

Walker, Jennifer K M; Cohen, Hannah; Higgins, Logan M; Kennedy, Peter G

2014-04-01

Alnus trees associate with ectomycorrhizal (ECM) fungi and nitrogen-fixing Frankia bacteria and, although their ECM fungal communities are uncommonly host specific and species poor, it is unclear whether the functioning of Alnus ECM fungal symbionts differs from that of other ECM hosts. We used exoenzyme root tip assays and molecular identification to test whether ECM fungi on Alnus rubra differed in their ability to access organic phosphorus (P) and nitrogen (N) when compared with ECM fungi on the non-Frankia host Pseudotsuga menziesii. At the community level, potential acid phosphatase (AP) activity of ECM fungal root tips from A. rubra was significantly higher than that from P. menziesii, whereas potential leucine aminopeptidase (LA) activity was significantly lower for A. rubra root tips at one of the two sites. At the individual species level, there was no clear relationship between ECM fungal relative root tip abundance and relative AP or LA enzyme activities on either host. Our results are consistent with the hypothesis that ECM fungal communities associated with Alnus trees have enhanced organic P acquisition abilities relative to non-Frankia ECM hosts. This shift, in combination with the chemical conditions present in Alnus forest soils, may drive the atypical structure of Alnus ECM fungal communities. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Global Analysis Reveals the Complexity of the Human Glomerular Extracellular Matrix

PubMed Central

Byron, Adam; Humphries, Jonathan D.; Randles, Michael J.; Carisey, Alex; Murphy, Stephanie; Knight, David; Brenchley, Paul E.; Zent, Roy; Humphries, Martin J.

2014-01-01

The glomerulus contains unique cellular and extracellular matrix (ECM) components, which are required for intact barrier function. Studies of the cellular components have helped to build understanding of glomerular disease; however, the full composition and regulation of glomerular ECM remains poorly understood. We used mass spectrometry-based proteomics of enriched ECM extracts for a global analysis of human glomerular ECM in vivo and identified a tissue-specific proteome of 144 structural and regulatory ECM proteins. This catalog includes all previously identified glomerular components plus many new and abundant components. Relative protein quantification showed a dominance of collagen IV, collagen I, and laminin isoforms in the glomerular ECM together with abundant collagen VI and TINAGL1. Protein network analysis enabled the creation of a glomerular ECM interactome, which revealed a core of highly connected structural components. More than one half of the glomerular ECM proteome was validated using colocalization studies and data from the Human Protein Atlas. This study yields the greatest number of ECM proteins relative to previous investigations of whole glomerular extracts, highlighting the importance of sample enrichment. It also shows that the composition of glomerular ECM is far more complex than previously appreciated and suggests that many more ECM components may contribute to glomerular development and disease processes. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000456. PMID:24436468

Growth Factor-Reinforced ECM Fabricated from Chemically Hypoxic MSC Sheet with Improved In Vivo Wound Repair Activity.

PubMed

Du, Hui-Cong; Jiang, Lin; Geng, Wen-Xin; Li, Jing; Zhang, Rui; Dang, Jin-Ge; Shu, Mao-Guo; Li, Li-Wen

2017-01-01

MSC treatment can promote cutaneous wound repair through multiple mechanisms, and paracrine mediators secreted by MSC are responsible for most of its therapeutic benefits. Recently, MSC sheet composed of live MSCs and their secreted ECMs was reported to promote wound healing; however, whether its ECM alone could accelerate wound closure remained unknown. In this study, Nc-ECM and Cc-ECM were prepared from nonconditioned and CoCl 2 -conditioned MSC sheets, respectively, and their wound healing properties were evaluated in a mouse model of full-thickness skin defect. Our results showed that Nc-ECM can significantly promote wound repair through early adipocyte recruitment, rapid reepithelialization, enhanced granulation tissue growth, and augmented angiogenesis. Moreover, conditioning of MSC sheet with CoCl 2 dramatically enriched its ECM with collagen I, collagen III, TGF- β 1, VEGF, and bFGF via activation of HIF-1 α and hence remarkably improved its ECM's in vivo wound healing potency. All the Cc-ECM-treated wounds completely healed on day 7, while Nc-ECM-treated wounds healed about 85.0% ± 8.6%, and no-treatment wounds only healed 69.8% ± 9.6% ( p < 0.05). Therefore, we believe that such growth factor-reinforced ECM fabricated from chemically hypoxic MSC sheet has the potential for clinical translation and will lead to a MSC-derived, cost-effective, bankable biomaterial for wound management.

Qualitative human body composition analysis assessed with bioelectrical impedance.

PubMed

Talluri, T

1998-12-01

Body composition is generally aiming at quantitative estimates of fat mass, inadequate to assess nutritional states that on the other hand are well defined by the intra/extra cellular masses proportion (ECM/BCM). Direct measures performed with phase sensitive bioelectrical impedance analyzers can be used to define the current distribution in normal and abnormal populations. Phase angle and reactance nomogram is directly reflecting the ECM/BCM pathways proportions and body impedance analysis (BIA) is also validated to estimate the individual content of body cell mass (BCM). A new body cell mass index (BCMI) obtained dividing the weight of BCM in kilograms by the body surface in square meters is confronted to the scatterplot distribution of phase angle and reactance values obtained from controls and patients, and proposed as a qualitative approach to identify abnormal ECM/BCM ratios and nutritional states.

ECM1 regulates tumor metastasis and CSC-like property through stabilization of β-catenin.

PubMed

Lee, K-m; Nam, K; Oh, S; Lim, J; Kim, R K; Shim, D; Choi, J-h; Lee, S-J; Yu, J-H; Lee, J W; Ahn, S H; Shin, I

2015-12-10

Extracellular Matrix Protein 1 (ECM1) is a marker for tumorigenesis and is correlated with invasiveness and poor prognosis in various types of cancer. However, the functional role of ECM1 in cancer metastasis is unclear. Here, we detected high ECM1 level in breast cancer patient sera that was associated with recurrence of tumor. The modulation of ECM1 expression affected not only cell migration and invasion, but also sphere-forming ability and drug resistance in breast cancer cell lines. In addition, ECM1 regulated the gene expression associated with the epithelial to mesenchymal transition (EMT) progression and cancer stem cell (CSC) maintenance. Interestingly, ECM1 increased β-catenin expression at the post-translational level through induction of MUC1, which was physically associated with β-catenin. Indeed, the association between β-catenin and the MUC1 cytoplasmic tail was increased by ECM1. Furthermore, forced expression of β-catenin altered the gene expression that potentiated EMT progression and CSC phenotype maintenance in the cells. These data provide evidence that ECM1 has an important role in cancer metastasis through β-catenin stabilization.

Trabecular meshwork ECM remodeling in glaucoma: could RAS be a target?

PubMed

Agarwal, Puneet; Agarwal, Renu

2018-06-14

Disturbances of extracellular matrix (ECM) homeostasis in trabecular meshwork (TM) cause increased aqueous outflow resistance leading to elevated intraocular pressure (IOP) in glaucomatous eyes. Therefore, restoration of ECM homeostasis is a rational approach to prevent disease progression. Since renin-angiotensin system (RAS) inhibition positively alters ECM homeostasis in cardiovascular pathologies involving pressure and volume overload, it is likely that RAS inhibitors reduce IOP primarily by restoring ECM homeostasis. Areas covered: Current evidence showing the presence of RAS components in ocular tissue and its role in regulating aqueous humor dynamics is briefly summarized. The role of RAS in ECM remodeling is discussed both in terms of its effects on ECM synthesis and its breakdown. The mechanisms of ECM remodeling involving interactions of RAS with transforming growth factor-β, Wnt/β-catenin signaling, bone morphogenic proteins, connective tissue growth factor, and matrix metalloproteinases in ocular tissue are discussed. Expert opinion: Current literature strongly indicates a significant role of RAS in ECM remodeling in TM of hypertensive eyes. Hence, IOP-lowering effect of RAS inhibitors may primarily be attributed to restoration of ECM homeostasis in aqueous outflow pathways rather than its vascular effects. However, the mechanistic targets for RAS inhibitors have much wider distribution and consequences, which remain relatively unexplored in TM.

Preparation and Characterization of a Chitosan/Gelatin/Extracellular Matrix Scaffold and Its Application in Tissue Engineering.

PubMed

Wang, Xiaoyan; Yu, Tailong; Chen, Guanghua; Zou, Jilong; Li, Jianzhong; Yan, Jinglong

2017-03-01

Previous studies have demonstrated that extracellular matrix (ECM) can be used in tissue engineering due to its bioactivity. However, adipose-derived ECM (A-dECM) has never been applied in bone tissue engineering, and it is unknown whether it would be beneficial to the growth of bone marrow mesenchymal stem cells (BMSCs). In this study, we produced chitosan/gelatin/A-dECM (C/G/A-dECM) scaffolds via lyophilization and crosslinking; chitosan/gelatin (C/G) scaffolds were used as controls. For the C/G/A-dECM scaffolds, the average pore size was 285.93 ± 85.39 μm; the average porosity was 90.62 ± 3.65%; the average compressive modulus was 0.87 ± 0.05 kPa; and the average water uptake ratio was 13.73 ± 1.16. In vitro, A-dECM scaffolds could promote the attachment and proliferation of BMSCs. In the same osteogenic-inducing reagent, better osteogenic differentiation could be observed for the C/G/A-dECM scaffolds than for the C/G scaffolds. Thus, we conclude that A-dECM is a promising material and that C/G/A-dECM scaffolds are a candidate for bone tissue engineering.

Online quantitative monitoring of live cell engineered cartilage growth using diffuse fiber-optic Raman spectroscopy.

PubMed

Bergholt, Mads S; Albro, Michael B; Stevens, Molly M

2017-09-01

Tissue engineering (TE) has the potential to improve the outcome for patients with osteoarthritis (OA). The successful clinical translation of this technique as part of a therapy requires the ability to measure extracellular matrix (ECM) production of engineered tissues in vitro, in order to ensure quality control and improve the likelihood of tissue survival upon implantation. Conventional techniques for assessing the ECM content of engineered cartilage, such as biochemical assays and histological staining are inherently destructive. Raman spectroscopy, on the other hand, represents a non-invasive technique for in situ biochemical characterization. Here, we outline current roadblocks in translational Raman spectroscopy in TE and introduce a comprehensive workflow designed to non-destructively monitor and quantify ECM biomolecules in large (>3 mm), live cell TE constructs online. Diffuse near-infrared fiber-optic Raman spectra were measured from live cell cartilaginous TE constructs over a 56-day culturing period. We developed a multivariate curve resolution model that enabled quantitative biochemical analysis of the TE constructs. Raman spectroscopy was able to non-invasively quantify the ECM components and showed an excellent correlation with biochemical assays for measurement of collagen (R 2  = 0.84) and glycosaminoglycans (GAGs) (R 2  = 0.86). We further demonstrated the robustness of this technique for online prospective analysis of live cell TE constructs. The fiber-optic Raman spectroscopy strategy developed in this work offers the ability to non-destructively monitor construct growth online and can be adapted to a broad range of TE applications in regenerative medicine toward controlled clinical translation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comprehensive proteomic characterization of stem cell-derived extracellular matrices.

PubMed

Ragelle, Héloïse; Naba, Alexandra; Larson, Benjamin L; Zhou, Fangheng; Prijić, Miralem; Whittaker, Charles A; Del Rosario, Amanda; Langer, Robert; Hynes, Richard O; Anderson, Daniel G

2017-06-01

In the stem-cell niche, the extracellular matrix (ECM) serves as a structural support that additionally provides stem cells with signals that contribute to the regulation of stem-cell function, via reciprocal interactions between cells and components of the ECM. Recently, cell-derived ECMs have emerged as in vitro cell culture substrates to better recapitulate the native stem-cell microenvironment outside the body. Significant changes in cell number, morphology and function have been observed when mesenchymal stem cells (MSC) were cultured on ECM substrates as compared to standard tissue-culture polystyrene (TCPS). As select ECM components are known to regulate specific stem-cell functions, a robust characterization of cell-derived ECM proteomic composition is critical to better comprehend the role of the ECM in directing cellular processes. Here, we characterized and compared the protein composition of ECM produced in vitro by bone marrow-derived MSC, adipose-derived MSC and neonatal fibroblasts from different donors, employing quantitative proteomic methods. Each cell-derived ECM displayed a specific and unique matrisome signature, yet they all shared a common set of proteins. We evaluated the biological response of cells cultured on the different matrices and compared them to cells on standard TCPS. The matrices lead to differential survival and gene-expression profiles among the cell types and as compared to TCPS, indicating that the cell-derived ECMs influence each cell type in a different manner. This general approach to understanding the protein composition of different tissue-specific and cell-derived ECM will inform the rational design of defined systems and biomaterials that recapitulate critical ECM signals for stem-cell culture and tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lepton electric dipole moment and strong CP violation

NASA Astrophysics Data System (ADS)

Ghosh, Diptimoy; Sato, Ryosuke

2018-02-01

Contribution of the strong CP angle, θ bar , to the Wilson Coefficients of electron and muon electric dipole moment (EDM) operators are discussed. Previously, θ bar contribution to the electron EDM operator was calculated by Choi and Hong [1]. However, the effect of CP-violating three meson coupling was missing in [1]. We include this missing contribution for the first time in the literature, and reevaluate the Wilson coefficients of the lepton EDM operator. We obtain de = - (2.2 - 8.6) ×10-28 θ bar e-cm which is 15-70% of the result obtained in [1]. We also estimated the muon EDM as dμ = - (0.5 - 1.8) ×10-25 θ bar e-cm. Using | θ bar | ≲10-10 suggested by the neutron EDM measurements, we obtain |de | ≲ 8.6 ×10-38e-cm and |dμ | ≲ 1.8 ×10-35e-cm. The θ bar contribution to the muon EDM is much below the sensitivities of the current and near future experiments. Our result shows that the θ bar contribution to de,μ can be larger than the CKM contributions by many orders of magnitude.

Nanoscale viscoelasticity of extracellular matrix proteins in soft tissues: A multiscale approach.

PubMed

Miri, Amir K; Heris, Hossein K; Mongeau, Luc; Javid, Farhad

2014-02-01

It is hypothesized that the bulk viscoelasticity of soft tissues is determined by two length-scale-dependent mechanisms: the time-dependent response of the extracellular matrix (ECM) proteins at the nanometer scale and the biophysical interactions between the ECM solid structure and interstitial fluid at the micrometer scale. The latter is governed by poroelasticity theory assuming free motion of the interstitial fluid within the porous ECM structure. In a recent study (Heris, H.K., Miri, A.K., Tripathy, U., Barthelat, F., Mongeau, L., 2013. J. Mech. Behav. Biomed. Mater.), atomic force microscopy was used to measure the response of porcine vocal folds to a creep loading and a 50-nm sinusoidal oscillation. A constitutive model was calibrated and verified using a finite element model to accurately predict the nanoscale viscoelastic moduli of ECM. A generally good correlation was obtained between the predicted variation of the viscoelastic moduli with depth and that of hyaluronic acids in vocal fold tissue. We conclude that hyaluronic acids may regulate vocal fold viscoelasticity. The proposed methodology offers a characterization tool for biomaterials used in vocal fold augmentations. © 2013 Elsevier Ltd. All rights reserved.

Extracellular matrix in lung development, homeostasis and disease

DOE PAGES

Zhou, Yong; Horowitz, Jeffrey C.; Naba, Alexandra; ...

2018-03-08

Here, the lung's unique extracellular matrix (ECM), while providing structural support for cells, is critical in the regulation of developmental organogenesis, homeostasis and injury-repair responses. The ECM, via biochemical or biomechanical cues, regulates diverse cell functions, fate and phenotype. The composition and function of lung ECM become markedly deranged in pathological tissue remodeling. ECM-based therapeutics and bioengineering approaches represent promising novel strategies for regeneration/repair of the lung and treatment of chronic lung diseases. In this review, we assess the current state of lung ECM biology, including fundamental advances in ECM composition, dynamics, topography, and biomechanics; the role of the ECMmore » in normal and aberrant lung development, adult lung diseases and autoimmunity; and ECM in the regulation of the stem cell niche. We identify opportunities to advance the field of lung ECM biology and provide a set recommendations for research priorities to advance knowledge that would inform novel approaches to the pathogenesis, diagnosis, and treatment of chronic lung diseases.« less

Extracellular matrix in lung development, homeostasis and disease

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

Zhou, Yong; Horowitz, Jeffrey C.; Naba, Alexandra

Here, the lung's unique extracellular matrix (ECM), while providing structural support for cells, is critical in the regulation of developmental organogenesis, homeostasis and injury-repair responses. The ECM, via biochemical or biomechanical cues, regulates diverse cell functions, fate and phenotype. The composition and function of lung ECM become markedly deranged in pathological tissue remodeling. ECM-based therapeutics and bioengineering approaches represent promising novel strategies for regeneration/repair of the lung and treatment of chronic lung diseases. In this review, we assess the current state of lung ECM biology, including fundamental advances in ECM composition, dynamics, topography, and biomechanics; the role of the ECMmore » in normal and aberrant lung development, adult lung diseases and autoimmunity; and ECM in the regulation of the stem cell niche. We identify opportunities to advance the field of lung ECM biology and provide a set recommendations for research priorities to advance knowledge that would inform novel approaches to the pathogenesis, diagnosis, and treatment of chronic lung diseases.« less

Molecular assessment of collagen denaturation in decellularized tissues using a collagen hybridizing peptide.

PubMed

Hwang, Jeongmin; San, Boi Hoa; Turner, Neill J; White, Lisa J; Faulk, Denver M; Badylak, Stephen F; Li, Yang; Yu, S Michael

2017-04-15

Decellularized extracellular matrix (ECM) derived from tissues and organs are emerging as important scaffold materials for regenerative medicine. Many believe that preservation of the native ECM structure during decellularization is highly desirable. However, because effective techniques to assess the structural damage in ECM are lacking, the disruptive effects of a decellularization method and the impact of the associated structural damage upon the scaffold's regenerative capacity are often debated. Using a novel collagen hybridizing peptide (CHP) that specifically binds to unfolded collagen chains, we investigated the molecular denaturation of collagen in the ECM decellularized by four commonly used cell-removing detergents: sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), sodium deoxycholate (SD), and Triton X-100. Staining of the detergent-treated porcine ligament and urinary bladder matrix with carboxyfluorescein-labeled CHP demonstrated that SDS and Triton X-100 denature the triple helical collagen molecule while CHAPS and SD do not, although second harmonic generation imaging and transmission electron microscopy (TEM) revealed that all four detergents disrupt collagen fibrils. Our findings from the CHP staining were further confirmed by the circular dichroism spectra of intact triple helical collagen molecules in CHAPS and SD solutions, and the TEM images of CHP-conjugated gold nanoparticles binding only to the SDS and Triton X-100 treated collagen fibrils. CHP is a powerful new tool for direct and reliable measurement of denatured collagen molecules in decellularized tissues. It is expected to have wide applications in the development and standardization of the tissue/organ decellularization technology. Preservation of the native ECM structure in decellularized tissues is highly desirable, since denaturation of ECM molecules (e.g., collagen) during decellularization can strongly influence the cellular response. Unfortunately, conventional techniques (SEM, SHG) are not conducive to identifying denatured collagen molecules in tissues. We demonstrate the first investigation into the molecular denaturation of collagen in decellularized ECM enabled by a novel Collagen Hybridizing Peptide (CHP) that specifically binds to unfolded collagen chains. We show that SDS and Triton X-100 denature collagen molecules while CHAPS and SD cannot. Such detection has been nearly impossible with other existing techniques. The CHP technique will advance our understanding about the effect of the cell-removing process on ECM, and lead to development of the decellularization technology. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Molecular assessment of collagen denaturation in decellularized tissues using a collagen hybridizing peptide

PubMed Central

Hwang, Jeongmin; San, Boi Hoa; Turner, Neill J.; White, Lisa J.; Faulk, Denver M.; Badylak, Stephen F.; Li, Yang; Yu, S. Michael

2017-01-01

Decellularized extracellular matrix (ECM) derived from tissues and organs are emerging as important scaffold materials for regenerative medicine. Many believe that preservation of the native ECM structure during decellularization is highly desirable. However, because effective techniques to assess the structural damage in ECM are lacking, the disruptive effects of a decellularization method and the impact of the associated structural damage upon the scaffold’s regenerative capacity are often debated. Using a novel collagen hybridizing peptide (CHP) that specifically binds to unfolded collagen chains, we investigated the molecular denaturation of collagen in the ECM decellularized by four commonly used cellremoving detergents: sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propa nesulfonate (CHAPS), sodium deoxycholate (SD), and Triton X-100. Staining of the detergent-treated porcine ligament and urinary bladder matrix with carboxyfluorescein-labeled CHP demonstrated that SDS and Triton X-100 denature the triple helical collagen molecule while CHAPS and SD do not, although second harmonic generation imaging and transmission electron microscopy (TEM) revealed that all four detergents disrupt collagen fibrils. Our findings from the CHP staining were further confirmed by the circular dichroism spectra of intact triple helical collagen molecules in CHAPS and SD solutions, and the TEM images of CHP-conjugated gold nanoparticles binding only to the SDS and Triton X-100 treated collagen fibrils. CHP is a powerful new tool for direct and reliable measurement of denatured collagen molecules in decellularized tissues. It is expected to have wide applications in the development and standardization of the tissue/organ decellularization technology. Statement of Significance Preservation of the native ECM structure in decellularized tissues is highly desirable, since denaturation of ECM molecules (e.g., collagen) during decellularization can strongly influence the cellular response. Unfortunately, conventional techniques (SEM, SHG) are not conducive to identifying denatured collagen molecules in tissues. We demonstrate the first investigation into the molecular denaturation of collagen in decellularized ECM enabled by a novel Collagen Hybridizing Peptide (CHP) that specifically binds to unfolded collagen chains. We show that SDS and Triton X-100 denature collagen molecules while CHAPS and SD cannot. Such detection has been nearly impossible with other existing techniques. The CHP technique will advance our understanding about the effect of the cell-removing process on ECM, and lead to development of the decellularization technology. PMID:28161576

Using Bayesian hierarchical models to better understand nitrate sources and sinks in agricultural watersheds.

PubMed

Xia, Yongqiu; Weller, Donald E; Williams, Meghan N; Jordan, Thomas E; Yan, Xiaoyuan

2016-11-15

Export coefficient models (ECMs) are often used to predict nutrient sources and sinks in watersheds because ECMs can flexibly incorporate processes and have minimal data requirements. However, ECMs do not quantify uncertainties in model structure, parameters, or predictions; nor do they account for spatial and temporal variability in land characteristics, weather, and management practices. We applied Bayesian hierarchical methods to address these problems in ECMs used to predict nitrate concentration in streams. We compared four model formulations, a basic ECM and three models with additional terms to represent competing hypotheses about the sources of error in ECMs and about spatial and temporal variability of coefficients: an ADditive Error Model (ADEM), a SpatioTemporal Parameter Model (STPM), and a Dynamic Parameter Model (DPM). The DPM incorporates a first-order random walk to represent spatial correlation among parameters and a dynamic linear model to accommodate temporal correlation. We tested the modeling approach in a proof of concept using watershed characteristics and nitrate export measurements from watersheds in the Coastal Plain physiographic province of the Chesapeake Bay drainage. Among the four models, the DPM was the best--it had the lowest mean error, explained the most variability (R 2  = 0.99), had the narrowest prediction intervals, and provided the most effective tradeoff between fit complexity (its deviance information criterion, DIC, was 45.6 units lower than any other model, indicating overwhelming support for the DPM). The superiority of the DPM supports its underlying hypothesis that the main source of error in ECMs is their failure to account for parameter variability rather than structural error. Analysis of the fitted DPM coefficients for cropland export and instream retention revealed some of the factors controlling nitrate concentration: cropland nitrate exports were positively related to stream flow and watershed average slope, while instream nitrate retention was positively correlated with nitrate concentration. By quantifying spatial and temporal variability in sources and sinks, the DPM provides new information to better target management actions to the most effective times and places. Given the wide use of ECMs as research and management tools, our approach can be broadly applied in other watersheds and to other materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Critical Role of Transient Activity of MT1-MMP for ECM Degradation in Invadopodia

PubMed Central

Watanabe, Ayako; Hosino, Daisuke; Koshikawa, Naohiko; Seiki, Motoharu; Suzuki, Takashi; Ichikawa, Kazuhisa

2013-01-01

Focal degradation of extracellular matrix (ECM) is the first step in the invasion of cancer cells. MT1-MMP is a potent membrane proteinase employed by aggressive cancer cells. In our previous study, we reported that MT1-MMP was preferentially located at membrane protrusions called invadopodia, where MT1-MMP underwent quick turnover. Our computer simulation and experiments showed that this quick turnover was essential for the degradation of ECM at invadopodia (Hoshino, D., et al., (2012) PLoS Comp. Biol., 8: e1002479). Here we report on characterization and analysis of the ECM-degrading activity of MT1-MMP, aiming at elucidating a possible reason for its repetitive insertion in the ECM degradation. First, in our computational model, we found a very narrow transient peak in the activity of MT1-MMP followed by steady state activity. This transient activity was due to the inhibition by TIMP-2, and the steady state activity of MT1-MMP decreased dramatically at higher TIMP-2 concentrations. Second, we evaluated the role of the narrow transient activity in the ECM degradation. When the transient activity was forcibly suppressed in computer simulations, the ECM degradation was heavily suppressed, indicating the essential role of this transient peak in the ECM degradation. Third, we compared continuous and pulsatile turnover of MT1-MMP in the ECM degradation at invadopodia. The pulsatile insertion showed basically consistent results with the continuous insertion in the ECM degradation, and the ECM degrading efficacy depended heavily on the transient activity of MT1-MMP in both models. Unexpectedly, however, low-frequency/high-concentration insertion of MT1-MMP was more effective in ECM degradation than high-frequency/low-concentration pulsatile insertion even if the time-averaged amount of inserted MT1-MMP was the same. The present analysis and characterization of ECM degradation by MT1-MMP together with our previous report indicate a dynamic nature of MT1-MMP at invadopodia and the importance of its transient peak in the degradation of the ECM. PMID:23737743

A strategy for tissue self-organization that is robust to cellular heterogeneity and plasticity

PubMed Central

Cerchiari, Alec E.; Garbe, James C.; Jee, Noel Y.; Todhunter, Michael E.; Broaders, Kyle E.; Peehl, Donna M.; Desai, Tejal A.; LaBarge, Mark A.; Thomson, Matthew; Gartner, Zev J.

2015-01-01

Developing tissues contain motile populations of cells that can self-organize into spatially ordered tissues based on differences in their interfacial surface energies. However, it is unclear how self-organization by this mechanism remains robust when interfacial energies become heterogeneous in either time or space. The ducts and acini of the human mammary gland are prototypical heterogeneous and dynamic tissues comprising two concentrically arranged cell types. To investigate the consequences of cellular heterogeneity and plasticity on cell positioning in the mammary gland, we reconstituted its self-organization from aggregates of primary cells in vitro. We find that self-organization is dominated by the interfacial energy of the tissue–ECM boundary, rather than by differential homo- and heterotypic energies of cell–cell interaction. Surprisingly, interactions with the tissue–ECM boundary are binary, in that only one cell type interacts appreciably with the boundary. Using mathematical modeling and cell-type-specific knockdown of key regulators of cell–cell cohesion, we show that this strategy of self-organization is robust to severe perturbations affecting cell–cell contact formation. We also find that this mechanism of self-organization is conserved in the human prostate. Therefore, a binary interfacial interaction with the tissue boundary provides a flexible and generalizable strategy for forming and maintaining the structure of two-component tissues that exhibit abundant heterogeneity and plasticity. Our model also predicts that mutations affecting binary cell–ECM interactions are catastrophic and could contribute to loss of tissue architecture in diseases such as breast cancer. PMID:25633040

The alterations in the extracellular matrix composition guide the repair of damaged liver tissue

PubMed Central

Klaas, Mariliis; Kangur, Triin; Viil, Janeli; Mäemets-Allas, Kristina; Minajeva, Ave; Vadi, Krista; Antsov, Mikk; Lapidus, Natalia; Järvekülg, Martin; Jaks, Viljar

2016-01-01

While the cellular mechanisms of liver regeneration have been thoroughly studied, the role of extracellular matrix (ECM) in liver regeneration is still poorly understood. We utilized a proteomics-based approach to identify the shifts in ECM composition after CCl4 or DDC treatment and studied their effect on the proliferation of liver cells by combining biophysical and cell culture methods. We identified notable alterations in the ECM structural components (eg collagens I, IV, V, fibronectin, elastin) as well as in non-structural proteins (eg olfactomedin-4, thrombospondin-4, armadillo repeat-containing x-linked protein 2 (Armcx2)). Comparable alterations in ECM composition were seen in damaged human livers. The increase in collagen content and decrease in elastic fibers resulted in rearrangement and increased stiffness of damaged liver ECM. Interestingly, the alterations in ECM components were nonhomogenous and differed between periportal and pericentral areas and thus our experiments demonstrated the differential ability of selected ECM components to regulate the proliferation of hepatocytes and biliary cells. We define for the first time the alterations in the ECM composition of livers recovering from damage and present functional evidence for a coordinated ECM remodelling that ensures an efficient restoration of liver tissue. PMID:27264108

Extracellular matrix components in breast cancer progression and metastasis.

PubMed

Oskarsson, Thordur

2013-08-01

The extracellular matrix (ECM) is composed of highly variable and dynamic components that regulate cell behavior. The protein composition and physical properties of the ECM govern cell fate through biochemical and biomechanical mechanisms. This requires a carefully orchestrated and thorough regulation considering that a disturbed ECM can have serious consequences and lead to pathological conditions like cancer. In breast cancer, many ECM proteins are significantly deregulated and specific matrix components promote tumor progression and metastatic spread. Intriguingly, several ECM proteins that are associated with breast cancer development, overlap substantially with a group of ECM proteins induced during the state of tissue remodeling such as mammary gland involution. Fibrillar collagens, fibronectin, hyaluronan and matricellular proteins are matrix components that are common to both involution and cancer. Moreover, some of these proteins have in recent years been identified as important constituents of metastatic niches in breast cancer. In addition, specific ECM molecules, their receptors or enzymatic modifiers are significantly involved in resistance to therapeutic intervention. Further analysis of these ECM proteins and the downstream ECM mediated signaling pathways may provide a range of possibilities to identify druggable targets against advanced breast cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ectomycorrhizal fungi of the Seychelles: diversity patterns and host shifts from the native Vateriopsis seychellarum (Dipterocarpaceae) and Intsia bijuga (Caesalpiniaceae) to the introduced Eucalyptus robusta (Myrtaceae), but not Pinus caribea (Pinaceae).

PubMed

Tedersoo, Leho; Suvi, Triin; Beaver, Katy; Kõljalg, Urmas

2007-01-01

Ectomycorrhizal (ECM) fungi form highly diverse communities in temperate forests, but little is known about their community ecology in tropical ecosystems. Using anatomotyping and rDNA sequencing, ECM fungi were identified on root tips of the introduced Eucalyptus robusta and Pinus caribea as well as the endemic Vateriopsis seychellarum and indigenous Intsia bijuga in the Seychelles. Sequencing revealed 30 species of ECM fungi on root tips of V. seychellarum and I. bijuga, with three species overlapping. Eucalyptus robusta shared five of these taxa, whereas P. caribea hosted three unique species of ECM fungi that were likely cointroduced with containerized seedlings. The thelephoroid (including the anamorphic genus Riessiella), euagaric, boletoid and hymenochaetoid clades of basidiomycetes dominated the ECM fungal community of native trees. Two species of Annulatascaceae (Sordariales, Ascomycota) were identified and described as ECM symbionts of V. seychellarum. The low diversity of native ECM fungi is attributed to deforestation and long-term isolation of the Seychelles. Native ECM fungi associate with exotic eucalypts, whereas cointroduced ECM fungi persist in pine plantations for decades.

Extracellular Matrix Degradation and Remodeling in Development and Disease

PubMed Central

Lu, Pengfei; Takai, Ken; Weaver, Valerie M.; Werb, Zena

2011-01-01

The extracellular matrix (ECM) serves diverse functions and is a major component of the cellular microenvironment. The ECM is a highly dynamic structure, constantly undergoing a remodeling process where ECM components are deposited, degraded, or otherwise modified. ECM dynamics are indispensible during restructuring of tissue architecture. ECM remodeling is an important mechanism whereby cell differentiation can be regulated, including processes such as the establishment and maintenance of stem cell niches, branching morphogenesis, angiogenesis, bone remodeling, and wound repair. In contrast, abnormal ECM dynamics lead to deregulated cell proliferation and invasion, failure of cell death, and loss of cell differentiation, resulting in congenital defects and pathological processes including tissue fibrosis and cancer. Understanding the mechanisms of ECM remodeling and its regulation, therefore, is essential for developing new therapeutic interventions for diseases and novel strategies for tissue engineering and regenerative medicine. PMID:21917992

Hindrances to precise recovery of cellular forces in fibrous biopolymer networks.

PubMed

Zhang, Yunsong; Feng, Jingchen; Heizler, Shay I; Levine, Herbert

2018-01-11

How cells move through the three-dimensional extracellular matrix (ECM) is of increasing interest in attempts to understand important biological processes such as cancer metastasis. Just as in motion on flat surfaces, it is expected that experimental measurements of cell-generated forces will provide valuable information for uncovering the mechanisms of cell migration. However, the recovery of forces in fibrous biopolymer networks may suffer from large errors. Here, within the framework of lattice-based models, we explore possible issues in force recovery by solving the inverse problem: how can one determine the forces cells exert to their surroundings from the deformation of the ECM? Our results indicate that irregular cell traction patterns, the uncertainty of local fiber stiffness, the non-affine nature of ECM deformations and inadequate knowledge of network topology will all prevent the precise force determination. At the end, we discuss possible ways of overcoming these difficulties.

High-performance fiber optic link for ECM antenna remoting

NASA Astrophysics Data System (ADS)

Edge, Colin; Burgess, John W.; Wale, Michael J.; Try, Nicholas W.

1998-11-01

The ability to remotely radiate microwave signals has become an essential feature of modern electronic counter-measures (ECM) systems. The use of fiber optics allows remote microwave links to be constructed which have very low propagation loss and dispersion, are very flexible and light in weight, and have a high degree of immunity from external electromagnetic fields, crosstalk and environmental effects. This combination of desirable characteristics are very beneficial to avionic ECM antenna remoting as well as many other applications. GEC-Marconi have developed high performance fiber components for use in a towed radar decoy. The resulting rugged and compact optical transmitter and receiver modules have been developed and proven to maintain the required performance over the full hostile range of environmental conditions encountered on a fast jet. Packaged fiber optic links have been produced which can achieve a compression dynamic range of greater than 87 dB in 1 MHz bandwidth over a 2 to 18 GHz.

Hindrances to precise recovery of cellular forces in fibrous biopolymer networks

NASA Astrophysics Data System (ADS)

Zhang, Yunsong; Feng, Jingchen; Heizler, Shay I.; Levine, Herbert

2018-03-01

How cells move through the three-dimensional extracellular matrix (ECM) is of increasing interest in attempts to understand important biological processes such as cancer metastasis. Just as in motion on flat surfaces, it is expected that experimental measurements of cell-generated forces will provide valuable information for uncovering the mechanisms of cell migration. However, the recovery of forces in fibrous biopolymer networks may suffer from large errors. Here, within the framework of lattice-based models, we explore possible issues in force recovery by solving the inverse problem: how can one determine the forces cells exert to their surroundings from the deformation of the ECM? Our results indicate that irregular cell traction patterns, the uncertainty of local fiber stiffness, the non-affine nature of ECM deformations and inadequate knowledge of network topology will all prevent the precise force determination. At the end, we discuss possible ways of overcoming these difficulties.

The Ectomycorrhizal Fungal Community in a Neotropical Forest Dominated by the Endemic Dipterocarp Pakaraimaea dipterocarpacea

PubMed Central

Smith, Matthew E.; Henkel, Terry W.; Uehling, Jessie K.; Fremier, Alexander K.; Clarke, H. David; Vilgalys, Rytas

2013-01-01

Ectomycorrhizal (ECM) plants and fungi can be diverse and abundant in certain tropical ecosystems. For example, the primarily paleotropical ECM plant family Dipterocarpaceae is one of the most speciose and ecologically important tree families in Southeast Asia. Pakaraimaea dipterocarpacea is one of two species of dipterocarp known from the Neotropics, and is also the only known member of the monotypic Dipterocarpaceae subfamily Pakaraimoideae. This Guiana Shield endemic is only known from the sandstone highlands of Guyana and Venezuela. Despite its unique phylogenetic position and unusual geographical distribution, the ECM fungal associations of P. dipterocarpacea are understudied throughout the tree’s range. In December 2010 we sampled ECM fungi on roots of P. dipterocarpacea and the co-occurring ECM tree Dicymbe jenmanii (Fabaceae subfamily Caesalpinioideae) in the Upper Mazaruni River Basin of Guyana. Based on ITS rDNA sequencing we documented 52 ECM species from 11 independent fungal lineages. Due to the phylogenetic distance between the two host tree species, we hypothesized that P. dipterocarpacea would harbor unique ECM fungi not found on the roots of D. jenmanii. Although statistical tests suggested that several ECM fungal species did exhibit host preferences for either P. dipterocarpacea or D. jenmanii, most of the ECM fungi were multi-host generalists. We also detected several ECM fungi that have never been found in long-term studies of nearby rainforests dominated by other Dicymbe species. One particular mushroom-forming fungus appears to be unique and may represent a new ECM lineage of Agaricales that is endemic to the Neotropics. PMID:23383090

Components, structure, biogenesis and function of the Hydra extracellular matrix in regeneration, pattern formation and cell differentiation.

PubMed

Sarras, Michael P

2012-01-01

The body wall of Hydra is organized as an epithelial bilayer (ectoderm and endoderm) with an intervening extracellular matrix (ECM), termed mesoglea by early biologists. Morphological studies have determined that Hydra ECM is composed of two basal lamina layers positioned at the base of each epithelial layer with an intervening interstitial matrix. Molecular and biochemical analyses of Hydra ECM have established that it contains components similar to those seen in more complicated vertebrate species. These components include such macromolecules as laminin, type IV collagen, and various fibrillar collagens. These components are synthesized in a complicated manner involving cross-talk between the epithelial bilayer. Any perturbation to ECM biogenesis leads to a blockage in Hydra morphogenesis. Blockage in ECM/cell interactions in the adult polyp also leads to problems in epithelial transdifferentiation processes. In terms of biophysical parameters, Hydra ECM is highly flexible; a property that facilitates continuous movements along the organism's longitudinal and radial axis. This is in contrast to the more rigid matrices often found in vertebrates. The flexible nature of Hydra ECM can in part now be explained by the unique structure of the organism's type IV collagen and fibrillar collagens. This review will focus on Hydra ECM in regard to: 1) its general structure, 2) its molecular composition, 3) the biophysical basis for the flexible nature of Hydra's ECM, 4) the relationship of the biogenesis of Hydra ECM to regeneration of body form, and 5) the functional role of Hydra ECM during pattern formation and cell differentiation.

Extracellular matrix biomimicry for the creation of investigational and therapeutic devices.

PubMed

Pellowe, Amanda S; Gonzalez, Anjelica L

2016-01-01

The extracellular matrix (ECM) is a web of fibrous proteins that serves as a scaffold for tissues and organs, and is important for maintaining homeostasis and facilitating cellular adhesion. Integrin transmembrane receptors are the primary adhesion molecules that anchor cells to the ECM, thus integrating cells with their microenvironments. Integrins play a critical role in facilitating cell-matrix interactions and promoting signal transduction, both from the cell to the ECM and vice versa, ultimately mediating cell behavior. For this reason, many advanced biomaterials employ biomimicry by replicating the form and function of fibrous ECM proteins. The ECM also acts as a reservoir for small molecules and growth factors, wherein fibrous proteins directly bind and present these bioactive moieties that facilitate cell activity. Therefore biomimicry can be enhanced by incorporating small molecules into ECM-like substrates. Biomimetic ECM materials have served as invaluable research tools for studying interactions between cells and the surrounding ECM, revealing that cell-matrix signaling is driven by mechanical forces, integrin engagement, and small molecules. Mimicking pathological ECMs has also elucidated disease specific cell behaviors. For example, biomimetic tumor microenvironments have been used to induce metastatic cell behaviors, and have thereby shown promise for in vitro cancer drug testing and targeting. Further, ECM-like substrates have been successfully employed for autologous cell recolonization for tissue engineering and wound healing. As we continue to learn more about the mechanical and biochemical characteristics of the ECM, these properties can be harnessed to develop new biomaterials, biomedical devices, and therapeutics. © 2015 Wiley Periodicals, Inc.

The influence of extracelluar matrix on intramuscular and extramuscular adipogenesis

USDA-ARS?s Scientific Manuscript database

The extracellular matrix (ECM) and specific ECM components can have a major influence on cell growth, development and phenotype. The influence of the ECM and ECM components on adipogenesis in vivo and in vitro will be reviewed. Engelbreth-Holm-Swarm (EHS) substratum and laminin per se markedly incre...

Non-Muscle Myosin II Isoforms Have Different Functions in Matrix Rearrangement by MDA-MB-231 Cells

PubMed Central

Hindman, Bridget; Goeckeler, Zoe; Sierros, Kostas; Wysolmerski, Robert

2015-01-01

The role of a stiffening extra-cellular matrix (ECM) in cancer progression is documented but poorly understood. Here we use a conditioning protocol to test the role of nonmuscle myosin II isoforms in cell mediated ECM arrangement using collagen constructs seeded with breast cancer cells expressing shRNA targeted to either the IIA or IIB heavy chain isoform. While there are several methods available to measure changes in the biophysical characteristics of the ECM, we wanted to use a method which allows for the measurement of global stiffness changes as well as a dynamic response from the sample over time. The conditioning protocol used allows the direct measurement of ECM stiffness. Using various treatments, it is possible to determine the contribution of various construct and cellular components to the overall construct stiffness. Using this assay, we show that both the IIA and IIB isoforms are necessary for efficient matrix remodeling by MDA-MB-231 breast cancer cells, as loss of either isoform changes the stiffness of the collagen constructs as measured using our conditioning protocol. Constructs containing only collagen had an elastic modulus of 0.40 Pascals (Pa), parental MDA-MB-231 constructs had an elastic modulus of 9.22 Pa, while IIA and IIB KD constructs had moduli of 3.42 and 7.20 Pa, respectively. We also calculated the cell and matrix contributions to the overall sample elastic modulus. Loss of either myosin isoform resulted in decreased cell stiffness, as well as a decrease in the stiffness of the cell-altered collagen matrices. While the total construct modulus for the IIB KD cells was lower than that of the parental cells, the IIB KD cell-altered matrices actually had a higher elastic modulus than the parental cell-altered matrices (4.73 versus 4.38 Pa). These results indicate that the IIA and IIB heavy chains play distinct and non-redundant roles in matrix remodeling. PMID:26136073

Extracellular matrix and its receptors in Drosophila neural development

PubMed Central

Broadie, Kendal; Baumgartner, Stefan; Prokop, Andreas

2011-01-01

Extracellular matrix (ECM) and matrix receptors are intimately involved in most biological processes. The ECM plays fundamental developmental and physiological roles in health and disease, including processes underlying the development, maintenance and regeneration of the nervous system. To understand the principles of ECM-mediated functions in the nervous system, genetic model organisms like Drosophila provide simple, malleable and powerful experimental platforms. This article provides an overview of ECM proteins and receptors in Drosophila. It then focuses on their roles during three progressive phases of neural development: 1) neural progenitor proliferation, 2) axonal growth and pathfinding and 3) synapse formation and function. Each section highlights known ECM and ECM-receptor components and recent studies done in mutant conditions to reveal their in vivo functions, all illustrating the enormous opportunities provided when merging work on the nervous system with systematic research into ECM-related gene functions. PMID:21688401

Implications of Extracellular Matrix Production by Adipose Tissue-Derived Stem Cells for Development of Wound Healing Therapies.

PubMed

Hyldig, Kathrine; Riis, Simone; Pennisi, Cristian Pablo; Zachar, Vladimir; Fink, Trine

2017-05-31

The synthesis and deposition of extracellular matrix (ECM) plays an important role in the healing of acute and chronic wounds. Consequently, the use of ECM as treatment for chronic wounds has been of special interest-both in terms of inducing ECM production by resident cells and applying ex vivo produced ECM. For these purposes, using adipose tissue-derived stem cells (ASCs) could be of use. ASCs are recognized to promote wound healing of otherwise chronic wounds, possibly through the reduction of inflammation, induction of angiogenesis, and promotion of fibroblast and keratinocyte growth. However, little is known regarding the importance of ASC-produced ECM for wound healing. In this review, we describe the importance of ECM for wound healing, and how ECM production by ASCs may be exploited in developing new therapies for the treatment of chronic wounds.

42 CFR 456.725 - Funding of ECM system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 4 2011-10-01 2011-10-01 false Funding of ECM system. 456.725 Section 456.725... Claims Management System for Outpatient Drug Claims § 456.725 Funding of ECM system. (a) For funds....722, FFP is available at a matching rate of 90 percent. After fiscal year 1992, ECM subsystems are...

42 CFR 456.725 - Funding of ECM system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Funding of ECM system. 456.725 Section 456.725... Claims Management System for Outpatient Drug Claims § 456.725 Funding of ECM system. (a) For funds....722, FFP is available at a matching rate of 90 percent. After fiscal year 1992, ECM subsystems are...

Coating extracellular matrix proteins on a (3-aminopropyl)triethoxysilane-treated glass substrate for improved cell culture.

PubMed

Masuda, Hiro-taka; Ishihara, Seiichiro; Harada, Ichiro; Mizutani, Takeomi; Ishikawa, Masayori; Kawabata, Kazushige; Haga, Hisashi

2014-01-01

We demonstrate that a (3-aminopropyl)triethoxysilane-treated glass surface is superior to an untreated glass surface for coating with extracellular matrix (ECM) proteins when used as a cell culture substrate to observe cell physiology and behavior. We found that MDCK cells cultured on untreated glass coated with ECM removed the coated ECM protein and secreted different ECM proteins. In contrast, the cells did not remove the coated ECM protein when seeded on (3-aminopropyl)triethoxysilane-treated (i.e., silanized) glass coated with ECM. Furthermore, the morphology and motility of cells grown on silanized glass differed from those grown on non-treated glass, even when both types of glass were initially coated with laminin. We also found that cells on silanized glass coated with laminin had higher motility than those on silanized glass coated with fibronectin. Based on our results, we suggest that silanized glass is a more suitable cell culture substrate than conventional non-treated glass when coated by ECM for observations of ECM effects on cell physiology.

In vivo imaging of basement membrane movement: ECM patterning shapes Hydra polyps.

PubMed

Aufschnaiter, Roland; Zamir, Evan A; Little, Charles D; Özbek, Suat; Münder, Sandra; David, Charles N; Li, Li; Sarras, Michael P; Zhang, Xiaoming

2011-12-01

Growth and morphogenesis during embryonic development, asexual reproduction and regeneration require extensive remodeling of the extracellular matrix (ECM). We used the simple metazoan Hydra to examine the fate of ECM during tissue morphogenesis and asexual budding. In growing Hydra, epithelial cells constantly move towards the extremities of the animal and into outgrowing buds. It is not known, whether these tissue movements involve epithelial migration relative to the underlying matrix or whether cells and ECM are displaced as a composite structure. Furthermore, it is unclear, how the ECM is remodeled to adapt to the shape of developing buds and tentacles. To address these questions, we used a new in vivo labeling technique for Hydra collagen-1 and laminin, and tracked the fate of ECM in all body regions of the animal. Our results reveal that Hydra 'tissue movements' are largely displacements of epithelial cells together with associated ECM. By contrast, during the evagination of buds and tentacles, extensive movement of epithelial cells relative to the matrix is observed, together with local ECM remodeling. These findings provide new insights into the nature of growth and morphogenesis in epithelial tissues.

Proteolytic and non-proteolytic regulation of collective cell invasion: tuning by ECM density and organization

PubMed Central

Kumar, Sandeep; Kapoor, Aastha; Desai, Sejal; Inamdar, Mandar M.; Sen, Shamik

2016-01-01

Cancer cells manoeuvre through extracellular matrices (ECMs) using different invasion modes, including single cell and collective cell invasion. These modes rely on MMP-driven ECM proteolysis to make space for cells to move. How cancer-associated alterations in ECM influence the mode of invasion remains unclear. Further, the sensitivity of the two invasion modes to MMP dynamics remains unexplored. In this paper, we address these open questions using a multiscale hybrid computational model combining ECM density-dependent MMP secretion, MMP diffusion, ECM degradation by MMP and active cell motility. Our results demonstrate that in randomly aligned matrices, collective cell invasion is more efficient than single cell invasion. Although increase in MMP secretion rate enhances invasiveness independent of cell–cell adhesion, sustenance of collective invasion in dense matrices requires high MMP secretion rates. However, matrix alignment can sustain both single cell and collective cell invasion even without ECM proteolysis. Similar to our in-silico observations, increase in ECM density and MMP inhibition reduced migration of MCF-7 cells embedded in sandwich gels. Together, our results indicate that apart from cell intrinsic factors (i.e., high cell–cell adhesion and MMP secretion rates), ECM density and organization represent two important extrinsic parameters that govern collective cell invasion and invasion plasticity. PMID:26832069

Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems.

PubMed

Baskaran, Preetisri; Hyvönen, Riitta; Berglund, S Linnea; Clemmensen, Karina E; Ågren, Göran I; Lindahl, Björn D; Manzoni, Stefano

2017-02-01

Tree growth in boreal forests is limited by nitrogen (N) availability. Most boreal forest trees form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve the uptake of inorganic N and also have the capacity to decompose soil organic matter (SOM) and to mobilize organic N ('ECM decomposition'). To study the effects of 'ECM decomposition' on ecosystem carbon (C) and N balances, we performed a sensitivity analysis on a model of C and N flows between plants, SOM, saprotrophs, ECM fungi, and inorganic N stores. The analysis indicates that C and N balances were sensitive to model parameters regulating ECM biomass and decomposition. Under low N availability, the optimal C allocation to ECM fungi, above which the symbiosis switches from mutualism to parasitism, increases with increasing relative involvement of ECM fungi in SOM decomposition. Under low N conditions, increased ECM organic N mining promotes tree growth but decreases soil C storage, leading to a negative correlation between C stores above- and below-ground. The interplay between plant production and soil C storage is sensitive to the partitioning of decomposition between ECM fungi and saprotrophs. Better understanding of interactions between functional guilds of soil fungi may significantly improve predictions of ecosystem responses to environmental change. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Cauda equina-derived extracellular matrix for fabrication of nanostructured hybrid scaffolds applied to neural tissue engineering.

PubMed

Wen, Xiaoxiao; Wang, Yu; Guo, Zhiyuan; Meng, Haoye; Huang, Jingxiang; Zhang, Li; Zhao, Bin; Zhao, Qing; Zheng, Yudong; Peng, Jiang

2015-03-01

Extracellular matrix (ECM) components have become important candidate materials for use as neural scaffolds for neural tissue engineering. In the current study, we prepared cauda equina-derived ECM materials for the production of scaffolds. Natural porcine cauda equina was decellularized using Triton X-100 and sodium deoxycholate, shattered physically, and made into a suspension by differential centrifugation. The decellularization procedure resulted in the removal of >94% of the nuclear material and preserved the extracellular collagen and sulfated glycosaminoglycan. Immunofluorescent staining confirmed the presence of collagen type I, laminin, and fibronectin in the ECM. The cauda equine-derived ECM was blended with poly(l-lactide-co-glycolide) (PLGA) to fabricate nanostructured scaffolds using electrospinning. The incorporation of the ECM increased the hydrophilicity of the scaffolds. Fourier transform infrared spectroscopy and multiphoton-induced autofluorescence images showed the presence of the ECM in the scaffolds. ECM/PLGA scaffolds were beneficial for the survival of Schwann cells compared with scaffolds consisting of PLGA alone, and the aligned fibers could regulate cell morphologic features by modulating cellular orientation. Axons in the dorsal root ganglia explants extended to a greater extent along ECM/PLGA compared with PLGA-alone fibers. The cauda equina ECM might be a promising material for forming scaffolds for use in neural tissue engineering.

Fetal brain extracellular matrix boosts neuronal network formation in 3D bioengineered model of cortical brain tissue.

PubMed

Sood, Disha; Chwalek, Karolina; Stuntz, Emily; Pouli, Dimitra; Du, Chuang; Tang-Schomer, Min; Georgakoudi, Irene; Black, Lauren D; Kaplan, David L

2016-01-01

The extracellular matrix (ECM) constituting up to 20% of the organ volume is a significant component of the brain due to its instructive role in the compartmentalization of functional microdomains in every brain structure. The composition, quantity and structure of ECM changes dramatically during the development of an organism greatly contributing to the remarkably sophisticated architecture and function of the brain. Since fetal brain is highly plastic, we hypothesize that the fetal brain ECM may contain cues promoting neural growth and differentiation, highly desired in regenerative medicine. Thus, we studied the effect of brain-derived fetal and adult ECM complemented with matricellular proteins on cortical neurons using in vitro 3D bioengineered model of cortical brain tissue. The tested parameters included neuronal network density, cell viability, calcium signaling and electrophysiology. Both, adult and fetal brain ECM as well as matricellular proteins significantly improved neural network formation as compared to single component, collagen I matrix. Additionally, the brain ECM improved cell viability and lowered glutamate release. The fetal brain ECM induced superior neural network formation, calcium signaling and spontaneous spiking activity over adult brain ECM. This study highlights the difference in the neuroinductive properties of fetal and adult brain ECM and suggests that delineating the basis for this divergence may have implications for regenerative medicine.

Extracellular matrix hydrogels from decellularized tissues: Structure and function.

PubMed

Saldin, Lindsey T; Cramer, Madeline C; Velankar, Sachin S; White, Lisa J; Badylak, Stephen F

2017-02-01

Extracellular matrix (ECM) bioscaffolds prepared from decellularized tissues have been used to facilitate constructive and functional tissue remodeling in a variety of clinical applications. The discovery that these ECM materials could be solubilized and subsequently manipulated to form hydrogels expanded their potential in vitro and in vivo utility; i.e. as culture substrates comparable to collagen or Matrigel, and as injectable materials that fill irregularly-shaped defects. The mechanisms by which ECM hydrogels direct cell behavior and influence remodeling outcomes are only partially understood, but likely include structural and biological signals retained from the native source tissue. The present review describes the utility, formation, and physical and biological characterization of ECM hydrogels. Two examples of clinical application are presented to demonstrate in vivo utility of ECM hydrogels in different organ systems. Finally, new research directions and clinical translation of ECM hydrogels are discussed. More than 70 papers have been published on extracellular matrix (ECM) hydrogels created from source tissue in almost every organ system. The present manuscript represents a review of ECM hydrogels and attempts to identify structure-function relationships that influence the tissue remodeling outcomes and gaps in the understanding thereof. There is a Phase 1 clinical trial now in progress for an ECM hydrogel. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Erratum: Measurement of σ(e+e-→ψ(3770)→hadrons) at Ec.m.=3773MeV [Phys. Rev. Lett. 96, 092002 (2006)

NASA Astrophysics Data System (ADS)

Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Gong, D. T.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Smith, A.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Zweber, P.; Ernst, J.; Arms, K.; Severini, H.; Dytman, S. A.; Love, W.; Mehrabyan, S.; Mueller, J. A.; Savinov, V.; Li, Z.; Lopez, A.; Mendez, H.; Ramirez, J.; Huang, G. S.; Miller, D. H.; Pavlunin, V.; Sanghi, B.; Shipsey, I. P. J.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Napolitano, J.; He, Q.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Coan, T. E.; Gao, Y. S.; Liu, F.; Artuso, M.; Boulahouache, C.; Blusk, S.; Butt, J.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Redjimi, R.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, K.; Csorna, S. E.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Briere, R. A.; Chen, G. P.; Chen, J.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Berkelman, K.; Cassel, D. G.; Duboscq, J. E.; Ecklund, K. M.; Ehrlich, R.; Fields, L.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Meyer, T. O.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Phillips, E. A.; Pivarski, J.; Riley, D.; Ryd, A.; Sadoff, A. J.; Schwarthoff, H.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Weinberger, M.; Athar, S. B.; Avery, P.; Breva-Newell, L.; Patel, R.; Potlia, V.; Stoeck, H.; Yelton, J.; Rubin, P.; Cawlfield, C.; Eisenstein, B. I.; Karliner, I.; Kim, D.; Lowrey, N.; Naik, P.; Sedlack, C.; Selen, M.; White, E. J.; Wiss, J.; Shepherd, M. R.; Asner, D. M.; Edwards, K. W.

2010-04-01

We have updated our measurement of the cross section for e^+e^- -> psi(3770) -> hadrons, our publication "Measurement of sigma(e^+e^- -> psi(3770) -> hadrons) at E_{c.m.} = 3773 MeV", arXiv:hep-ex/0512038, Phys.Rev.Lett.96, 092002 (2006). Simultaneous with this arXiv update, we have published an erratum in Phys.Rev.Lett.104, 159901 (2010). There, and in this update, we have corrected a mistake in the computation of the error on the difference of the cross sections for e^+e^- -> psi(3770) -> hadrons and e^+e^- -> psi(3770) -> DDbar. We have also used a more recent CLEO measurement of cross section for e^+e^- -> psi(3770) -> DDbar. From this, we obtain an upper limit on the branching fraction for psi(3770) -> non-DDbar of 9% at 90% confidence level.

Chitosan/silk fibroin-based, Schwann cell-derived extracellular matrix-modified scaffolds for bridging rat sciatic nerve gaps.

PubMed

Gu, Yun; Zhu, Jianbin; Xue, Chengbin; Li, Zhenmeiyu; Ding, Fei; Yang, Yumin; Gu, Xiaosong

2014-02-01

Extracellular matrix (ECM) plays a prominent role in establishing and maintaining an ideal microenvironment for tissue regeneration, and ECM scaffolds are used as a feasible alternative to cellular and molecular therapy in the fields of tissue engineering. Because of their advantages over tissue-derived ECM scaffolds, cultured cell-derived ECM scaffolds are beginning to attract attention, but they have been scarcely studied for peripheral nerve repair. Here we aimed to develop a tissue engineered nerve scaffold by reconstituting nerve cell-derived ECM with natural biomaterials. A protocol was adopted to prepare and characterize the cultured Schwann cell (SC)-derived ECM. A chitosan conduit and silk fibroin (SF) fibers were prepared, cultured with SCs for ECM deposition, and subjected to decellularization, followed by assembly into a chitosan/SF-based, SC-derived ECM-modified scaffold, which was used to bridge a 10 mm rat sciatic nerve gap. The results from morphological analysis as well as electrophysiological examination indicated that regenerative outcomes achieved by our developed scaffold were similar to those by an acellular nerve graft (namely a nerve tissue-derived ECM scaffold), but superior to those by a plain chitosan/SF scaffold. Moreover, blood and histopathological parameters confirmed the safety of scaffold modification by SC-derived ECM. Therefore, a hybrid scaffold based on joint use of acellular and classical biomaterials represents a promising approach to nerve tissue engineering. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dexamethasone attenuates oxidation of extracellular matrix proteins by human monocytes.

PubMed

Ahmed, Shahid; Adamidis, Ananea; Jan, Louis C; Gibbons, Nora; Mattana, Joseph

2003-10-01

In response to infection or in immune complex-mediated diseases, inflammatory cells may oxidatively damage extracellular matrix (ECM) proteins. In this study we evaluated whether human monocytes could oxidize ECM and whether this could be modulated by exposure to LPS, IgG complexes, and dexamethasone (DEX). Wells in tissue culture plates were coated with the ECM preparation Matrigel. Porous inserts with or without the human monocyte cell line THP-1 were placed into ECM-containing wells and cells were exposed to control conditions or to LPS (10 ng/ml), IgG complexes (200 and 500 microg/ml), or DEX (10(-7) and 10(-6) M). ECM was then subjected to Western blot analysis using an antibody to oxidized protein. In addition, Western blot analysis was carried out on DEX-treated cells to evaluate expression of the NADPH oxidase components p67-phox and gp91-phox. THP-1 cells enhanced ECM oxidation and this effect was augmented by LPS and by IgG aggregates. Preincubation of cells with DEX attenuated ECM oxidation and was also associated with decreased expression of p67-phox and gp91-phox. These findings suggest that human monocytes can oxidize ECM proteins and that this may be modulated by IgG complexes and LPS. Dexamethasone appears to attenuate ECM oxidation and a better understanding of this mechanism might allow for interventions to minimize oxidative damage to ECM proteins by monocytes in infectious and inflammatory states.

Feasibility of autologous bone marrow mesenchymal stem cell-derived extracellular matrix scaffold for cartilage tissue engineering.

PubMed

Tang, Cheng; Xu, Yan; Jin, Chengzhe; Min, Byoung-Hyun; Li, Zhiyong; Pei, Xuan; Wang, Liming

2013-12-01

Extracellular matrix (ECM) materials are widely used in cartilage tissue engineering. However, the current ECM materials are unsatisfactory for clinical practice as most of them are derived from allogenous or xenogenous tissue. This study was designed to develop a novel autologous ECM scaffold for cartilage tissue engineering. The autologous bone marrow mesenchymal stem cell-derived ECM (aBMSC-dECM) membrane was collected and fabricated into a three-dimensional porous scaffold via cross-linking and freeze-drying techniques. Articular chondrocytes were seeded into the aBMSC-dECM scaffold and atelocollagen scaffold, respectively. An in vitro culture and an in vivo implantation in nude mice model were performed to evaluate the influence on engineered cartilage. The current results showed that the aBMSC-dECM scaffold had a good microstructure and biocompatibility. After 4 weeks in vitro culture, the engineered cartilage in the aBMSC-dECM scaffold group formed thicker cartilage tissue with more homogeneous structure and higher expressions of cartilaginous gene and protein compared with the atelocollagen scaffold group. Furthermore, the engineered cartilage based on the aBMSC-dECM scaffold showed better cartilage formation in terms of volume and homogeneity, cartilage matrix content, and compressive modulus after 3 weeks in vivo implantation. These results indicated that the aBMSC-dECM scaffold could be a successful novel candidate scaffold for cartilage tissue engineering. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

Efficacy of rhBMP-2 Loaded PCL/β-TCP/bdECM Scaffold Fabricated by 3D Printing Technology on Bone Regeneration.

PubMed

Bae, Eun-Bin; Park, Keun-Ho; Shim, Jin-Hyung; Chung, Ho-Yun; Choi, Jae-Won; Lee, Jin-Ju; Kim, Chang-Hwan; Jeon, Ho-Jun; Kang, Seong-Soo; Huh, Jung-Bo

2018-01-01

This study was undertaken to evaluate the effect of 3D printed polycaprolactone (PCL)/ β -tricalcium phosphate ( β -TCP) scaffold containing bone demineralized and decellularized extracellular matrix (bdECM) and human recombinant bone morphogenetic protein-2 (rhBMP-2) on bone regeneration. Scaffolds were divided into PCL/ β -TCP, PCL/ β -TCP/bdECM, and PCL/ β -TCP/bdECM/BMP groups. In vitro release kinetics of rhBMP-2 were determined with respect to cell proliferation and osteogenic differentiation. These three reconstructive materials were implanted into 8 mm diameter calvarial bone defect in male Sprague-Dawley rats. Animals were sacrificed four weeks after implantation for micro-CT, histologic, and histomorphometric analyses. The findings obtained were used to calculate new bone volumes (mm 3 ) and new bone areas (%). Excellent cell bioactivity was observed in the PCL/ β -TCP/bdECM and PCL/ β -TCP/bdECM/BMP groups, and new bone volume and area were significantly higher in the PCL/ β -TCP/bdECM/BMP group than in the other groups ( p < .05). Within the limitations of this study, bdECM printed PCL/ β -TCP scaffolds can reproduce microenvironment for cells and promote adhering and proliferating the cells onto scaffolds. Furthermore, in the rat calvarial defect model, the scaffold which printed rhBMP-2 loaded bdECM stably carries rhBMP-2 and enhances bone regeneration confirming the possibility of bdECM as rhBMP-2 carrier.

A quantitative brain map of experimental cerebral malaria pathology.

PubMed

Strangward, Patrick; Haley, Michael J; Shaw, Tovah N; Schwartz, Jean-Marc; Greig, Rachel; Mironov, Aleksandr; de Souza, J Brian; Cruickshank, Sheena M; Craig, Alister G; Milner, Danny A; Allan, Stuart M; Couper, Kevin N

2017-03-01

The murine model of experimental cerebral malaria (ECM) has been utilised extensively in recent years to study the pathogenesis of human cerebral malaria (HCM). However, it has been proposed that the aetiologies of ECM and HCM are distinct, and, consequently, no useful mechanistic insights into the pathogenesis of HCM can be obtained from studying the ECM model. Therefore, in order to determine the similarities and differences in the pathology of ECM and HCM, we have performed the first spatial and quantitative histopathological assessment of the ECM syndrome. We demonstrate that the accumulation of parasitised red blood cells (pRBCs) in brain capillaries is a specific feature of ECM that is not observed during mild murine malaria infections. Critically, we show that individual pRBCs appear to occlude murine brain capillaries during ECM. As pRBC-mediated congestion of brain microvessels is a hallmark of HCM, this suggests that the impact of parasite accumulation on cerebral blood flow may ultimately be similar in mice and humans during ECM and HCM, respectively. Additionally, we demonstrate that cerebrovascular CD8+ T-cells appear to co-localise with accumulated pRBCs, an event that corresponds with development of widespread vascular leakage. As in HCM, we show that vascular leakage is not dependent on extensive vascular destruction. Instead, we show that vascular leakage is associated with alterations in transcellular and paracellular transport mechanisms. Finally, as in HCM, we observed axonal injury and demyelination in ECM adjacent to diverse vasculopathies. Collectively, our data therefore shows that, despite very different presentation, and apparently distinct mechanisms, of parasite accumulation, there appear to be a number of comparable features of cerebral pathology in mice and in humans during ECM and HCM, respectively. Thus, when used appropriately, the ECM model may be useful for studying specific pathological features of HCM.

Priming Endothelial Cells With a Melanoma-Derived Extracellular Matrix Triggers the Activation of αvβ3/VEGFR2 Axis.

PubMed

Helal-Neto, Edward; Brandão-Costa, Renata M; Saldanha-Gama, Roberta; Ribeiro-Pereira, Cristiane; Midlej, Victor; Benchimol, Marlene; Morandi, Verônica; Barja-Fidalgo, Christina

2016-11-01

The unique composition of tumor-produced extracellular matrix (ECM) can be a determining factor in changing the profile of endothelial cells in the tumor microenvironment. As the main receptor for ECM proteins, integrins can activate a series of signaling pathways related to cell adhesion, migration, and differentiation of endothelial cells that interact with ECM proteins. We studied the direct impact of the decellularized ECM produced by a highly metastatic human melanoma cell line (MV3) on the activation of endothelial cells and identified the intracellular signaling pathways associated with cell differentiation. Our data show that compared to the ECM derived from a human melanocyte cell line (NGM-ECM), ECM produced by a melanoma cell line (MV3-ECM) is considerably different in ultrastructural organization and composition and possesses a higher content of tenascin-C and laminin and a lower expression of fibronectin. When cultured directly on MV3-ECM, endothelial cells change morphology and show increased adhesion, migration, proliferation, and tubulogenesis. Interaction of endothelial cells with MV3-ECM induces the activation of integrin signaling, increasing FAK phosphorylation and its association with Src, which activates VEGFR2, potentiating the receptor response to VEGF. The blockage of αvβ3 integrin inhibited the FAK-Src association and VEGFR activation, thus reducing tubulogenesis. Together, our data suggest that the interaction of endothelial cells with the melanoma-ECM triggers integrin-dependent signaling, leading to Src pathway activation that may potentiate VEGFR2 activation and up-regulate angiogenesis. J. Cell. Physiol. 231: 2464-2473, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effect of chondrocyte-derived early extracellular matrix on chondrogenesis of placenta-derived mesenchymal stem cells.

PubMed

Park, Yong-Beom; Seo, Sinji; Kim, Jin-A; Heo, Jin-Chul; Lim, Young-Cheol; Ha, Chul-Won

2015-06-24

The extracellular matrix (ECM) surrounding cells contains a variety of proteins that provide structural support and regulate cellular functions. Previous studies have shown that decellularized ECM isolated from tissues or cultured cells can be used to improve cell differentiation in tissue engineering applications. In this study we evaluated the effect of decellularized chondrocyte-derived ECM (CDECM) on the chondrogenesis of human placenta-derived mesenchymal stem cells (hPDMSCs) in a pellet culture system. After incubation with or without chondrocyte-derived ECM in chondrogenic medium for 1 or 3 weeks, the sizes and wet masses of the cell pellets were compared with untreated controls (hPDMSCs incubated in chondrogenic medium without chondrocyte-derived ECM). In addition, histologic analysis of the cell pellets (Safranin O and collagen type II staining) and quantitative reverse transcription-PCR analysis of chondrogenic markers (aggrecan, collagen type II, and SOX9) were carried out. Our results showed that the sizes and masses of hPDMSC pellets incubated with chondrocyte-derived ECM were significantly higher than those of untreated controls. Differentiation of hPDMSCs (both with and without chondrocyte-derived ECM) was confirmed by Safranin O and collagen type II staining. Chondrogenic marker expression and glycosaminoglycan (GAG) levels were significantly higher in hPDMSC pellets incubated with chondrocyte-derived ECM compared with untreated controls, especially in cells precultured with chondrocyte-derived ECM for 7 d. Taken together, these results demonstrate that chondrocyte-derived ECM enhances the chondrogenesis of hPDMSCs, and this effect is further increased by preculture with chondrocyte-derived ECM. This preculture method for hPDMSC chondrogenesis represents a promising approach for cartilage tissue engineering.

A quantitative brain map of experimental cerebral malaria pathology

PubMed Central

Schwartz, Jean-Marc; Greig, Rachel; Mironov, Aleksandr; de Souza, J. Brian; Cruickshank, Sheena M.; Craig, Alister G.; Milner, Danny A.; Allan, Stuart M.

2017-01-01

The murine model of experimental cerebral malaria (ECM) has been utilised extensively in recent years to study the pathogenesis of human cerebral malaria (HCM). However, it has been proposed that the aetiologies of ECM and HCM are distinct, and, consequently, no useful mechanistic insights into the pathogenesis of HCM can be obtained from studying the ECM model. Therefore, in order to determine the similarities and differences in the pathology of ECM and HCM, we have performed the first spatial and quantitative histopathological assessment of the ECM syndrome. We demonstrate that the accumulation of parasitised red blood cells (pRBCs) in brain capillaries is a specific feature of ECM that is not observed during mild murine malaria infections. Critically, we show that individual pRBCs appear to occlude murine brain capillaries during ECM. As pRBC-mediated congestion of brain microvessels is a hallmark of HCM, this suggests that the impact of parasite accumulation on cerebral blood flow may ultimately be similar in mice and humans during ECM and HCM, respectively. Additionally, we demonstrate that cerebrovascular CD8+ T-cells appear to co-localise with accumulated pRBCs, an event that corresponds with development of widespread vascular leakage. As in HCM, we show that vascular leakage is not dependent on extensive vascular destruction. Instead, we show that vascular leakage is associated with alterations in transcellular and paracellular transport mechanisms. Finally, as in HCM, we observed axonal injury and demyelination in ECM adjacent to diverse vasculopathies. Collectively, our data therefore shows that, despite very different presentation, and apparently distinct mechanisms, of parasite accumulation, there appear to be a number of comparable features of cerebral pathology in mice and in humans during ECM and HCM, respectively. Thus, when used appropriately, the ECM model may be useful for studying specific pathological features of HCM. PMID:28273147

Soil Type Has a Stronger Role than Dipterocarp Host Species in Shaping the Ectomycorrhizal Fungal Community in a Bornean Lowland Tropical Rain Forest

PubMed Central

Essene, Adam L.; Shek, Katherine L.; Lewis, J. D.; Peay, Kabir G.; McGuire, Krista L.

2017-01-01

The role that mycorrhizal fungal associations play in the assembly of long-lived tree communities is poorly understood, especially in tropical forests, which have the highest tree diversity of any ecosystem. The lowland tropical rain forests of Southeast Asia are characterized by high levels of species richness within the family Dipterocarpaceae, the entirety of which has been shown to form obligate ectomycorrhizal (ECM) fungal associations. Differences in ECM assembly between co-occurring species of dipterocarp have been suggested, but never tested in adult trees, as a mechanism for maintaining the coexistence of closely related tree species in this family. Testing this hypothesis has proven difficult because the assembly of both dipterocarps and their ECM associates co-varies with the same edaphic variables. In this study, we used high-throughput DNA sequencing of soils and Sanger sequencing of root tips to evaluate how ECM fungi were structured within and across a clay–sand soil nutrient ecotone in a mixed-dipterocarp rain forest in Malaysian Borneo. We compared assembly patterns of ECM fungi in bulk soil to ECM root tips collected from three ecologically distinct species of dipterocarp. This design allowed us to test whether ECM fungi are more strongly structured by soil type or host specificity. As with previous studies of ECM fungi on this plot, we observed that clay vs. sand soil type strongly structured both the bulk soil and root tip ECM fungal communities. However, we also observed significantly different ECM communities associated with two of the three dipterocarp species evaluated on this plot. These results suggest that ECM fungal assembly on these species is shaped by a combination of biotic and abiotic factors, and that the soil edaphic niche occupied by different dipterocarp species may be mediated by distinct ECM fungal assemblages. PMID:29163567

Simulating ectomycorrhiza in boreal forests: implementing ectomycorrhizal fungi model MYCOFON in CoupModel (v5)

NASA Astrophysics Data System (ADS)

He, Hongxing; Meyer, Astrid; Jansson, Per-Erik; Svensson, Magnus; Rütting, Tobias; Klemedtsson, Leif

2018-02-01

The symbiosis between plants and Ectomycorrhizal fungi (ECM) is shown to considerably influence the carbon (C) and nitrogen (N) fluxes between the soil, rhizosphere, and plants in boreal forest ecosystems. However, ECM are either neglected or presented as an implicit, undynamic term in most ecosystem models, which can potentially reduce the predictive power of models.

In order to investigate the necessity of an explicit consideration of ECM in ecosystem models, we implement the previously developed MYCOFON model into a detailed process-based, soil-plant-atmosphere model, Coup-MYCOFON, which explicitly describes the C and N fluxes between ECM and roots. This new Coup-MYCOFON model approach (ECM explicit) is compared with two simpler model approaches: one containing ECM implicitly as a dynamic uptake of organic N considering the plant roots to represent the ECM (ECM implicit), and the other a static N approach in which plant growth is limited to a fixed N level (nonlim). Parameter uncertainties are quantified using Bayesian calibration in which the model outputs are constrained to current forest growth and soil C / N ratio for four forest sites along a climate and N deposition gradient in Sweden and simulated over a 100-year period.

The nonlim approach could not describe the soil C / N ratio due to large overestimation of soil N sequestration but simulate the forest growth reasonably well. The ECM implicit and explicit approaches both describe the soil C / N ratio well but slightly underestimate the forest growth. The implicit approach simulated lower litter production and soil respiration than the explicit approach. The ECM explicit Coup-MYCOFON model provides a more detailed description of internal ecosystem fluxes and feedbacks of C and N between plants, soil, and ECM. Our modeling highlights the need to incorporate ECM and organic N uptake into ecosystem models, and the nonlim approach is not recommended for future long-term soil C and N predictions. We also provide a key set of posterior fungal parameters that can be further investigated and evaluated in future ECM studies.

Region-Specific Effect of the Decellularized Meniscus Extracellular Matrix on Mesenchymal Stem Cell-Based Meniscus Tissue Engineering.

PubMed

Shimomura, Kazunori; Rothrauff, Benjamin B; Tuan, Rocky S

2017-03-01

The meniscus is the most commonly injured knee structure, and surgical repair is often ineffective. Tissue engineering-based repair or regeneration may provide a needed solution. Decellularized, tissue-derived extracellular matrices (ECMs) have received attention for their potential use as tissue-engineered scaffolds. In considering meniscus-derived ECMs (mECMs) for meniscus tissue engineering, it is noteworthy that the inner and outer regions of the meniscus have different structural and biochemical features, potentially directing the differentiation of cells toward region-specific phenotypes. To investigate the applicability of mECMs for meniscus tissue engineering by specifically comparing region-dependent effects of mECMs on 3-dimensional constructs seeded with human bone marrow mesenchymal stem cells (hBMSCs). Controlled laboratory study. Bovine menisci were divided into inner and outer halves and were minced, treated with Triton X-100 and DNase, and extracted with urea. Then, hBMSCs (1 × 10 6 cells/mL) were encapsulated in a photo-cross-linked 10% polyethylene glycol diacrylate scaffold containing mECMs (60 μg/mL) derived from either the inner or outer meniscus, with an ECM-free scaffold as a control. The cell-seeded constructs were cultured with chondrogenic medium containing recombinant human transforming growth factor β3 (TGF-β3) and were analyzed for expression of meniscus-associated genes as well as for the collagen (hydroxyproline) and glycosaminoglycan content as a function of time. Decellularization was verified by the absence of 4',6-diamidino-2-phenylindole (DAPI)-stained cell nuclei and a reduction in the DNA content. Quantitative real-time polymerase chain reaction showed that collagen type I expression was significantly higher in the outer mECM group than in the other groups, while collagen type II and aggrecan expression was highest in the inner mECM group. The collagen (hydroxyproline) content was highest in the outer mECM group, while the glycosaminoglycan content was higher in both the inner and outer mECM groups compared with the control group. These results showed that the inner mECM enhances the fibrocartilaginous differentiation of hBMSCs, while the outer mECM promotes a more fibroblastic phenotype. Our findings support the feasibility of fabricating bioactive scaffolds using region-specific mECM preparations for meniscus tissue engineering. This is the first report to demonstrate the feasibility of applying region-specific mECMs for the engineering of meniscus implants capable of reproducing the biphasic, anatomic, and biochemical characteristics of the meniscus, features that should contribute to the feasibility of their clinical application.

Assessing the functional mechanical properties of bioengineered organs with emphasis on the lung.

PubMed

Suki, Béla

2014-09-01

Recently, an exciting new approach has emerged in regenerative medicine pushing the forefront of tissue engineering to create bioartificial organs. The basic idea is to create biological scaffolds made of extracellular matrix (ECM) that preserves the three-dimensional architecture of an entire organ. These scaffolds are then used as templates for functional tissue and organ reconstruction after re-seeding the structure with stem cells or appropriately differentiated cells. In order to make sure that these bioartificial organs will be able to function in the mechanical environment of the native tissue, it is imperative to fully characterize their mechanical properties and match them with those of the normal native organs. This mini-review briefly summarizes modern measurement techniques of mechanical function characterized mostly by the material or volumetric stiffness. Micro-scale and macro-scale techniques such as atomic force microscopy and the tissue strip stress-strain approach are discussed with emphasis on those that combine mechanical measurements with structural visualization. Proper micro-scale stiffness helps attachment and differentiation of cells in the bioartificial organ whereas macro-scale functionality is provided by the overall mechanical properties of the construct. Several approaches including failure mechanics are also described, which specifically probe the contributions of the main ECM components including collagen, elastin, and proteoglycans to organ level ECM function. Advantages, drawbacks, and possible pitfalls as well as interpretation of the data are given throughout. Finally, specific techniques to assess the functionality of the ECM of bioartificial lungs are separately discussed. © 2014 Wiley Periodicals, Inc.

Power Plant Replacement Study

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

Reed, Gary

2010-09-30

This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to bemore » self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.« less

77 FR 41260 - Second Amendment to July 14, 2011 Order for Swap Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... herein; and removes any reference to the exempt commercial market (``ECM'') and exempt board of trade... transacted on either an ECM or EBOT to include transactions in agricultural commodities. \\7\\ Amendment to... agricultural swaps to be entered into or executed on an ECM or EBOT. The Commission noted that ECMs and EBOTs...

Matrix-Dependent Perturbation of TGFβ Signaling and Disease

PubMed Central

Doyle, Jefferson J.; Gerber, Elizabeth E.; Dietz, Harry C.

2012-01-01

Transforming growth factor beta (TGFβ) is a multipotent cytokine that is sequestered in the extracellular matrix (ECM) through interactions with a number of ECM proteins. The ECM serves to concentrate latent TGFβ at sites of intended function, to influence the bioavailability and/or function of TGFβ activators, and perhaps to regulate the intrinsic performance of cell surface effectors of TGFβ signal propagation. The downstream consequences of TGFβ signaling cascades in turn provide feedback modulation of the ECM. This review covers recent examples of how genetic mutations in constituents of the ECM or TGFβ signaling cascade result in altered ECM homeostasis, cellular performance and ultimately disease, with an emphasis on emerging therapeutic strategies that seek to capitalize on this refined mechanistic understanding. PMID:22641039

Probing cooperative force generation in collective cancer invasion

NASA Astrophysics Data System (ADS)

Alobaidi, Amani A.; Xu, Yaopengxiao; Chen, Shaohua; Jiao, Yang; Sun, Bo

2017-08-01

Collective cellular dynamics in the three-dimensional extracellular matrix (ECM) plays a crucial role in many physiological processes such as cancer invasion. Both chemical and mechanical signaling support cell-cell communications on a variety of length scales, leading to collective migratory behaviors. Here we conduct experiments using 3D in vitro tumor models and develop a phenomenological model in order to probe the cooperativity of force generation in the collective invasion of breast cancer cells. In our model, cell-cell communication is characterized by a single parameter that quantifies the correlation length of cellular migration cycles. We devise a stochastic reconstruction method to generate realizations of cell colonies with specific contraction phase correlation functions and correlation length a. We find that as a increases, the characteristic size of regions containing cells with similar contraction phases grows. For small a values, the large fluctuations in individual cell contraction phases smooth out the temporal fluctuations in the time-dependent deformation field in the ECM. For large a values, the periodicity of an individual cell contraction cycle is clearly manifested in the temporal variation of the overall deformation field in the ECM. Through quantitative comparisons of the simulated and experimentally measured deformation fields, we find that the correlation length for collective force generation in the breast cancer diskoid in geometrically micropatterned ECM (DIGME) system is a≈ 25~μ \\text{m} , which is roughly twice the linear size of a single cell. One possible mechanism for this intermediate cell correlation length is the fiber-mediated stress propagation in the 3D ECM network in the DIGME system.

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in hypertension and their relationship to cardiovascular risk and treatment: a substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT).

PubMed

Tayebjee, Muzahir H; Nadar, Sunil; Blann, Andrew D; Gareth Beevers, D; MacFadyen, Robert J; Lip, Gregory Y H

2004-09-01

Hypertension results in structural changes to the cardiac and vascular extracellular matrix (ECM). Matrix metalloproteinases (MMP) and their inhibitors (TIMP) may play a central role in the modulation of this matrix. We hypothesized that both MMP-9 and TIMP-1 would be abnormal in hypertension, reflecting alterations in ECM turnover, and that their circulating levels should be linked to cardiovascular (CHD) and stroke (CVA) risk scores using the Framingham equation. Second, we hypothesized that treatment would result in changes in ECM indices. Plasma MMP-9 and TIMP-1 were measured before and after treatment (median 3 years) from 96 patients with uncontrolled hypertension participating in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT). Pretreatment values were compared to circulating MMP-9 and TIMP-1 levels in 45 age- and sex-matched healthy controls. Circulating pretreatment MMP-9 and TIMP-1 levels were significantly higher in patients with hypertension than in the normotensive controls (P =.0041 and P =.0166, respectively). Plasma MMP-9 levels decreased, and TIMP-1 levels increased after treatment (P =.035 and P =.005, respectively). Levels of MMP-9 correlated with CHD risk (r = 0.317, P =.007) and HDL cholesterol (r = -0.237, P =.022), but not CVA risk. There were no significant correlations between TIMP-1 and CVA or CHD scores. Increased circulating MMP-9 and TIMP-1 at baseline in patients with hypertension could reflect an increased deposition and retention of type I collagen at the expense of other components of ECM within the cardiac and vascular ECM. After cardiovascular risk management, MMP-9 levels decreased and TIMP-1 levels increased. Elevated levels of MMP-9 also appeared to be associated with higher Framingham cardiovascular risk scores. Our observations suggest a possible role for these surrogate markers of tissue ECM composition and the prognosis of cardiovascular events in hypertension. Copyright 2004 American Journal of Hypertension, Ltd.

Formation and remodeling of the brain extracellular matrix in neural plasticity: Roles of chondroitin sulfate and hyaluronan.

PubMed

Miyata, Shinji; Kitagawa, Hiroshi

2017-10-01

The extracellular matrix (ECM) of the brain is rich in glycosaminoglycans such as chondroitin sulfate (CS) and hyaluronan. These glycosaminoglycans are organized into either diffuse or condensed ECM. Diffuse ECM is distributed throughout the brain and fills perisynaptic spaces, whereas condensed ECM selectively surrounds parvalbumin-expressing inhibitory neurons (PV cells) in mesh-like structures called perineuronal nets (PNNs). The brain ECM acts as a non-specific physical barrier that modulates neural plasticity and axon regeneration. Here, we review recent progress in understanding of the molecular basis of organization and remodeling of the brain ECM, and the involvement of several types of experience-dependent neural plasticity, with a particular focus on the mechanism that regulates PV cell function through specific interactions between CS chains and their binding partners. We also discuss how the barrier function of the brain ECM restricts dendritic spine dynamics and limits axon regeneration after injury. The brain ECM not only forms physical barriers that modulate neural plasticity and axon regeneration, but also forms molecular brakes that actively controls maturation of PV cells and synapse plasticity in which sulfation patterns of CS chains play a key role. Structural remodeling of the brain ECM modulates neural function during development and pathogenesis. Genetic or enzymatic manipulation of the brain ECM may restore neural plasticity and enhance recovery from nerve injury. This article is part of a Special Issue entitled Neuro-glycoscience, edited by Kenji Kadomatsu and Hiroshi Kitagawa. Copyright © 2017 Elsevier B.V. All rights reserved.

Concentration-dependent rheological properties of ECM hydrogel for intracerebral delivery to a stroke cavity

PubMed Central

Massensini, Andre R.; Ghuman, Harmanvir; Saldin, Lindsey T.; Medberry, Christopher J.; Keane, Timothy J.; Nicholls, Francesca J.; Velankar, Sachin S.; Badylak, Stephen F.; Modo, Michel

2015-01-01

Biomaterials composed of mammalian extracellular matrix (ECM) promote constructive tissue remodeling with minimal scar tissue formation in many anatomical sites. However, the optimal shape and form of ECM scaffold for each clinical application can vary markedly. ECM hydrogels have been shown to promote chemotaxis and differentiation of neuronal stem cells, but minimally invasive delivery of such scaffold materials to the central nervous system (CNS) would require an injectable form. These ECM materials can be manufactured to exist in fluid phase at room temperature, while forming hydrogels at body temperature in a concentration-dependent fashion. Implantation into the lesion cavity after a stroke could hence provide a means to support endogenous repair mechanisms. Herein, we characterize the rheological properties of an ECM hydrogel composed of urinary bladder matrix (UBM) that influence its delivery and in vivo interaction with host tissue. There was a notable concentration-dependence in viscosity, stiffness, and elasticity; all characteristics important for minimally invasive intracerebral delivery. An efficient MRI-guided injection with drainage of fluid from the cavity is described to assess in situ hydrogel formation and ECM retention at different concentrations (0, 1, 2, 3, 4, and 8 mg/mL). Only ECM concentrations >3 mg/mL gelled within the stroke cavity. Lower concentrations were not retained within the cavity, but extensive permeation of the liquid phase ECM into the peri-infarct area was evident. The concentration of ECM hydrogel is hence an important factor affecting gelation, host-biomaterial interface, as well intra-lesion distribution. PMID:26318805

Bi-directional signaling: Extracellular Matrix and Integrin Regulation of Breast Tumor Progression

PubMed Central

Gehler, Scott; Ponik, Suzanne M.; Riching, Kristin M; Keely, Patricia J.

2016-01-01

Cell transformation and tumor progression involves a common set of acquired capabilities, including increased proliferation, failure of cell death, self-sufficiency in growth, angiogenesis, and tumor cell invasion and metastasis (1). The stromal environment consists of many cell types, including fibroblasts, macrophages, and endothelial cells, in addition to various extracellular matrix (ECM) proteins that function to support normal tissue maintenance, but have also been implicated in tumor progression (2). Both the chemical and mechanical properties of the ECM have been shown to influence normal and malignant cell behavior. For instance, mesenchymal stem cells differentiate into specific lineages that are dependent on matrix stiffness (3), while tumor cells undergo changes in cell behavior and gene expression in response to matrix stiffness (4). ECM remodeling is implicated in tumor progression and includes changes in both the chemical and mechanical properties of the ECM (5) that can be a result of 1.) increased deposition of stromal ECM, 2.) enhanced contraction of ECM fibrils, and 3.) altered collagen alignment and ECM stiffness. In addition, remodeling of the ECM may alter whether tumor cells employ proteolytic degradation mechanisms during invasion and metastasis. Tumor cells respond to such changes in ECM remodeling through altered intracellular signaling and cell cycle control that lead to enhanced proliferation, loss of normal tissue architecture, and local tumor cell migration and invasion into the surrounding stromal tissue (6). This review will focus on the bi-directional interplay between the mechanical properties of the ECM and changes in integrin-mediated signal transduction events in an effort to elucidate cell behaviors during tumor progression. PMID:23582036

Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone-related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor.

PubMed

Kong, Li; Zhao, Yun-Peng; Tian, Qing-Yun; Feng, Jian-Quan; Kobayashi, Tatsuya; Merregaert, Joseph; Liu, Chuan-Ju

2016-08-01

Chondrogenesis and endochondral ossification are precisely controlled by cellular interactions with surrounding matrix proteins and growth factors that mediate cellular signaling pathways. Here, we report that extracellular matrix protein 1 (ECM1) is a previously unrecognized regulator of chondrogenesis. ECM1 is induced in the course of chondrogenesis and its expression in chondrocytes strictly depends on parathyroid hormone-related peptide (PTHrP) signaling pathway. Overexpression of ECM1 suppresses, whereas suppression of ECM1 enhances, chondrocyte differentiation and hypertrophy in vitro and ex vivo In addition, target transgene of ECM1 in chondrocytes or osteoblasts in mice leads to striking defects in cartilage development and endochondral bone formation. Of importance, ECM1 seems to be critical for PTHrP action in chondrogenesis, as blockage of ECM1 nearly abolishes PTHrP regulation of chondrocyte hypertrophy, and overexpression of ECM1 rescues disorganized growth plates of PTHrP-null mice. Furthermore, ECM1 and progranulin chondrogenic growth factor constitute an interaction network and act in concert in the regulation of chondrogenesis.-Kong, L., Zhao, Y.-P., Tian, Q.-Y., Feng, J.-Q., Kobayashi, T., Merregaert, J., Liu, C.-J. Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone-related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor. © FASEB.

Chondrogenic properties of collagen type XI, a component of cartilage extracellular matrix.

PubMed

Li, Ang; Wei, Yiyong; Hung, Clark; Vunjak-Novakovic, Gordana

2018-08-01

Cartilage extracellular matrix (ECM) has been used for promoting tissue engineering. However, the exact effects of ECM on chondrogenesis and the acting mechanisms are not well understood. In this study, we investigated the chondrogenic effects of cartilage ECM on human mesenchymal stem cells (MSCs) and identified the contributing molecular components. To this end, a preparation of articular cartilage ECM was supplemented to pellets of chondrogenically differentiating MSCs, pellets of human chondrocytes, and bovine articular cartilage explants to evaluate the effects on cell proliferation and the production of cartilaginous matrix. Selective enzymatic digestion and screening of ECM components were conducted to identify matrix molecules with chondrogenic properties. Cartilage ECM promoted MSC proliferation, production of cartilaginous matrix, and maturity of chondrogenic differentiation, and inhibited the hypertrophic differentiation of MSC-derived chondrocytes. Selective digestion of ECM components revealed a contributory role of collagens in promoting chondrogenesis. The screening of various collagen subtypes revealed strong chondrogenic effect of collagen type XI. Finally, collagen XI was found to promote production and inhibit degradation of cartilage matrix in human articular chondrocyte pellets and bovine articular cartilage explants. Our results indicate that cartilage ECM promotes chondrogenesis and inhibits hypertrophic differentiation in MSCs. Collagen type XI is the ECM component that has the strongest effects on enhancing the production and inhibiting the degradation of cartilage matrix. Copyright © 2018 Elsevier Ltd. All rights reserved.

Plant-derived micronutrients suppress monocyte adhesion to cultured human aortic endothelial cell layer by modulating its extracellular matrix composition.

PubMed

Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

2008-07-01

Monocyte adhesion to endothelium plays an important role in atherosclerosis. We investigated the effects of micronutrients on monocyte-binding properties of extracellular matrix (ECM) produced by human aortic endothelial cells (AoEC). Confluent cultures of AoEC were exposed to ascorbic acid, quercetin, gotu kola extract (10% asiatic acid), green tea extract (40% epigallocatechin gallate), or a mixture of these micronutrients for 48 hours. AoEC-produced ECM was exposed by differential treatment. U937 monocyte adhesion was assayed by fluorescence. ECM composition was assayed immunochemically and with radiolabeled metabolic precursors. AoEC exposure to micronutrients reduced ECM capacity to bind monocytes in a dose-dependent manner. This effect was accompanied by profound changes in the ECM composition. Correlation analysis revealed that changes in monocyte adhesion to ECM had the strongest positive correlation with ECM content for laminin (CC = 0.9681, P < 0.01), followed by fibronectin, collagens type III, I, and IV, biglycan, heparan sulfate, and elastin. The strongest negative correlation was with chondroitin sulfate (CC = -0.9623, P < 0.01), followed by perlecan and versican. Individual micronutrients had diverse effects on ECM composition and binding properties, and their mixture was the most effective treatment. In conclusion, micronutrient-dependent reduction of monocyte adhesion to endothelium is partly mediated through specific modulation of ECM composition and properties.

Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone–related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor

PubMed Central

Kong, Li; Zhao, Yun-Peng; Tian, Qing-Yun; Feng, Jian-Quan; Kobayashi, Tatsuya; Merregaert, Joseph; Liu, Chuan-Ju

2016-01-01

Chondrogenesis and endochondral ossification are precisely controlled by cellular interactions with surrounding matrix proteins and growth factors that mediate cellular signaling pathways. Here, we report that extracellular matrix protein 1 (ECM1) is a previously unrecognized regulator of chondrogenesis. ECM1 is induced in the course of chondrogenesis and its expression in chondrocytes strictly depends on parathyroid hormone–related peptide (PTHrP) signaling pathway. Overexpression of ECM1 suppresses, whereas suppression of ECM1 enhances, chondrocyte differentiation and hypertrophy in vitro and ex vivo. In addition, target transgene of ECM1 in chondrocytes or osteoblasts in mice leads to striking defects in cartilage development and endochondral bone formation. Of importance, ECM1 seems to be critical for PTHrP action in chondrogenesis, as blockage of ECM1 nearly abolishes PTHrP regulation of chondrocyte hypertrophy, and overexpression of ECM1 rescues disorganized growth plates of PTHrP-null mice. Furthermore, ECM1 and progranulin chondrogenic growth factor constitute an interaction network and act in concert in the regulation of chondrogenesis.—Kong, L., Zhao, Y.-P., Tian, Q.-Y., Feng, J.-Q., Kobayashi, T., Merregaert, J., Liu, C.-J. Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone–related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor. PMID:27075243

Adipose Extracellular Matrix/Stromal Vascular Fraction Gel Secretes Angiogenic Factors and Enhances Skin Wound Healing in a Murine Model.

PubMed

Sun, Mingliang; He, Yunfan; Zhou, Tao; Zhang, Pan; Gao, Jianhua; Lu, Feng

2017-01-01

Mesenchymal stem cells are an attractive cell type for cytotherapy in wound healing. The authors recently developed a novel, adipose-tissue-derived, injectable extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel) for stem cell therapy. This study was designed to assess the therapeutic effects of ECM/SVF-gel on wound healing and potential mechanisms. ECM/SVF-gel was prepared for use in nude mouse excisional wound healing model. An SVF cell suspension and phosphate-buffered saline injection served as the control. The expression levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and monocyte chemotactic protein-1 (MCP-1) in ECM/SVF-gel were analyzed at different time points. Angiogenesis (tube formation) assays of ECM/SVF-gel extracts were evaluated, and vessels density in skin was determined. The ECM/SVF-gel extract promoted tube formation in vitro and increased the expression of the angiogenic factors VEGF and bFGF compared with those in the control. The expression of the inflammatory chemoattractant MCP-1 was high in ECM/SVF-gel at the early stage and decreased sharply during the late stage of wound healing. The potent angiogenic effects exerted by ECM/SVF-gel may contribute to the improvement of wound healing, and these effects could be related to the enhanced inflammatory response in ECM/SVF-gel during the early stage of wound healing.

76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of the vehicle. 2. The ECM shall be set at no more than 68 mph by the manufacturer. 3. The ECM should be... ECM to be adjusted to let the vehicle exceed 68 mph. 4. Immediately upon the rule taking effect...

75 FR 23718 - Orders Finding That the Henry Financial Basis Contract, Henry Financial Index Contract and Henry...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... exempt commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or... with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs'') are traded--and treating ECMs in that category...

Effects of Ethanol on Brain Extracellular Matrix: Implications for Alcohol Use Disorder

PubMed Central

Lasek, Amy W.

2016-01-01

The brain extracellular matrix (ECM) occupies the space between cells and is involved in cell-matrix and cell-cell adhesion. However, in addition to providing structural support to brain tissue, the ECM activates cell signaling and controls synaptic transmission. The expression and activity of brain ECM components are regulated by alcohol exposure. This review will discuss what is currently known about the effects of alcohol on the activity and expression of brain ECM components. An interpretation of how these changes might promote alcohol use disorder (AUD) will be also provided. Ethanol exposure decreases levels of structural proteins involved in the interstitial matrix and basement membrane, with a concomitant increase in proteolytic enzymes that degrade these components. In contrast, ethanol exposure generally increases perineuronal net (PN) components. Because the ECM has been shown to regulate both synaptic plasticity and behavioral responses to drugs of abuse, regulation of the brain ECM by alcohol may be relevant to the development of alcoholism. Although investigation of the function of brain ECM in alcohol abuse is still in early stages, a greater understanding of the interplay between ECM and alcohol might lead to novel therapeutic strategies for treating AUD. PMID:27581478

Statistical Analysis of Categorical Time Series of Atmospheric Elementary Circulation Mechanisms - Dzerdzeevski Classification for the Northern Hemisphere

PubMed Central

Brenčič, Mihael

2016-01-01

Northern hemisphere elementary circulation mechanisms, defined with the Dzerdzeevski classification and published on a daily basis from 1899–2012, are analysed with statistical methods as continuous categorical time series. Classification consists of 41 elementary circulation mechanisms (ECM), which are assigned to calendar days. Empirical marginal probabilities of each ECM were determined. Seasonality and the periodicity effect were investigated with moving dispersion filters and randomisation procedure on the ECM categories as well as with the time analyses of the ECM mode. The time series were determined as being non-stationary with strong time-dependent trends. During the investigated period, periodicity interchanges with periods when no seasonality is present. In the time series structure, the strongest division is visible at the milestone of 1986, showing that the atmospheric circulation pattern reflected in the ECM has significantly changed. This change is result of the change in the frequency of ECM categories; before 1986, the appearance of ECM was more diverse, and afterwards fewer ECMs appear. The statistical approach applied to the categorical climatic time series opens up new potential insight into climate variability and change studies that have to be performed in the future. PMID:27116375

Remodeling and homeostasis of the extracellular matrix: implications for fibrotic diseases and cancer

PubMed Central

Cox, Thomas R.; Erler, Janine T.

2011-01-01

Dynamic remodeling of the extracellular matrix (ECM) is essential for development, wound healing and normal organ homeostasis. Life-threatening pathological conditions arise when ECM remodeling becomes excessive or uncontrolled. In this Perspective, we focus on how ECM remodeling contributes to fibrotic diseases and cancer, which both present challenging obstacles with respect to clinical treatment, to illustrate the importance and complexity of cell-ECM interactions in the pathogenesis of these conditions. Fibrotic diseases, which include pulmonary fibrosis, systemic sclerosis, liver cirrhosis and cardiovascular disease, account for over 45% of deaths in the developed world. ECM remodeling is also crucial for tumor malignancy and metastatic progression, which ultimately cause over 90% of deaths from cancer. Here, we discuss current methodologies and models for understanding and quantifying the impact of environmental cues provided by the ECM on disease progression, and how improving our understanding of ECM remodeling in these pathological conditions is crucial for uncovering novel therapeutic targets and treatment strategies. This can only be achieved through the use of appropriate in vitro and in vivo models to mimic disease, and with technologies that enable accurate monitoring, imaging and quantification of the ECM. PMID:21324931

ECM-Based Biohybrid Materials for Engineering Compliant, Matrix-Dense Tissues

PubMed Central

Bracaglia, Laura G.; Fisher, John P.

2015-01-01

An ideal tissue engineering scaffold should not only promote, but take an active role in, constructive remodeling and formation of site appropriate tissue. ECM-derived proteins provide unmatched cellular recognition, and therefore influence cellular response towards predicted remodeling behaviors. Materials built with only these proteins, however, can degrade rapidly or begin too weak to substitute for compliant, matrix-dense tissues. The focus of this review is on biohybrid materials that incorporate polymer components with ECM-derived proteins, to produce a substrate with desired mechanical and degradation properties, as well as actively guide tissue remodeling. Materials are described through four fabrication methods: (1) polymer and ECM-protein fibers woven together, (2) polymer and ECM proteins combined in a bilayer, (3) cell-built ECM on polymer scaffold, and (4) ECM proteins and polymers combined in a single hydrogel. Scaffolds from each fabrication method can achieve characteristics suitable for different types of tissue. In vivo testing has shown progressive remodeling in injury models, and suggests ECM-based biohybrid materials promote a prohealing immune response over single component alternatives. The prohealing immune response is associated with lasting success and long term host maintenance of the implant. PMID:26227679

In vivo imaging of basement membrane movement: ECM patterning shapes Hydra polyps

PubMed Central

Aufschnaiter, Roland; Zamir, Evan A.; Little, Charles D.; Özbek, Suat; Münder, Sandra; David, Charles N.; Li, Li; Sarras, Michael P.; Zhang, Xiaoming

2011-01-01

Growth and morphogenesis during embryonic development, asexual reproduction and regeneration require extensive remodeling of the extracellular matrix (ECM). We used the simple metazoan Hydra to examine the fate of ECM during tissue morphogenesis and asexual budding. In growing Hydra, epithelial cells constantly move towards the extremities of the animal and into outgrowing buds. It is not known, whether these tissue movements involve epithelial migration relative to the underlying matrix or whether cells and ECM are displaced as a composite structure. Furthermore, it is unclear, how the ECM is remodeled to adapt to the shape of developing buds and tentacles. To address these questions, we used a new in vivo labeling technique for Hydra collagen-1 and laminin, and tracked the fate of ECM in all body regions of the animal. Our results reveal that Hydra ‘tissue movements’ are largely displacements of epithelial cells together with associated ECM. By contrast, during the evagination of buds and tentacles, extensive movement of epithelial cells relative to the matrix is observed, together with local ECM remodeling. These findings provide new insights into the nature of growth and morphogenesis in epithelial tissues. PMID:22194305

Biological and MRI characterization of biomimetic ECM scaffolds for cartilage tissue regeneration.

PubMed

Ravindran, Sriram; Kotecha, Mrignayani; Huang, Chun-Chieh; Ye, Allen; Pothirajan, Padmabharathi; Yin, Ziying; Magin, Richard; George, Anne

2015-12-01

Osteoarthritis is the most common joint disorder affecting millions of people. Most scaffolds developed for cartilage regeneration fail due to vascularization and matrix mineralization. In this study we present a chondrogenic extracellular matrix (ECM) incorporated collagen/chitosan scaffold (chondrogenic ECM scaffold) for potential use in cartilage regenerative therapy. Biochemical characterization showed that these scaffolds possess key pro-chondrogenic ECM components and growth factors. MRI characterization showed that the scaffolds possess mechanical properties and diffusion characteristics important for cartilage tissue regeneration. In vivo implantation of the chondrogenic ECM scaffolds with bone marrow derived mesenchymal stem cells (MSCs) triggered chondrogenic differentiation of the MSCs without the need for external stimulus. Finally, results from in vivo MRI experiments indicate that the chondrogenic ECM scaffolds are stable and possess MR properties on par with native cartilage. Based on our results, we envision that such ECM incorporated scaffolds have great potential in cartilage regenerative therapy. Additionally, our validation of MR parameters with histology and biochemical analysis indicates the ability of MRI techniques to track the progress of our ECM scaffolds non-invasively in vivo; highlighting the translatory potential of this technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Defining the extracellular matrix using proteomics

PubMed Central

Byron, Adam; Humphries, Jonathan D; Humphries, Martin J

2013-01-01

The cell microenvironment has a profound influence on the behaviour, growth and survival of cells. The extracellular matrix (ECM) provides not only mechanical and structural support to cells and tissues but also binds soluble ligands and transmembrane receptors to provide spatial coordination of signalling processes. The ability of cells to sense the chemical, mechanical and topographical features of the ECM enables them to integrate complex, multiparametric information into a coherent response to the surrounding microenvironment. Consequently, dysregulation or mutation of ECM components results in a broad range of pathological conditions. Characterization of the composition of ECM derived from various cells has begun to reveal insights into ECM structure and function, and mechanisms of disease. Proteomic methodologies permit the global analysis of subcellular systems, but extracellular and transmembrane proteins present analytical difficulties to proteomic strategies owing to the particular biochemical properties of these molecules. Here, we review advances in proteomic approaches that have been applied to furthering our understanding of the ECM microenvironment. We survey recent studies that have addressed challenges in the analysis of ECM and discuss major outcomes in the context of health and disease. In addition, we summarize efforts to progress towards a systems-level understanding of ECM biology. PMID:23419153

Statistical Analysis of Categorical Time Series of Atmospheric Elementary Circulation Mechanisms - Dzerdzeevski Classification for the Northern Hemisphere.

PubMed

Brenčič, Mihael

2016-01-01

Northern hemisphere elementary circulation mechanisms, defined with the Dzerdzeevski classification and published on a daily basis from 1899-2012, are analysed with statistical methods as continuous categorical time series. Classification consists of 41 elementary circulation mechanisms (ECM), which are assigned to calendar days. Empirical marginal probabilities of each ECM were determined. Seasonality and the periodicity effect were investigated with moving dispersion filters and randomisation procedure on the ECM categories as well as with the time analyses of the ECM mode. The time series were determined as being non-stationary with strong time-dependent trends. During the investigated period, periodicity interchanges with periods when no seasonality is present. In the time series structure, the strongest division is visible at the milestone of 1986, showing that the atmospheric circulation pattern reflected in the ECM has significantly changed. This change is result of the change in the frequency of ECM categories; before 1986, the appearance of ECM was more diverse, and afterwards fewer ECMs appear. The statistical approach applied to the categorical climatic time series opens up new potential insight into climate variability and change studies that have to be performed in the future.

Low-dose oral rapamycin treatment reduces fibrogenesis, improves liver function, and prolongs survival in rats with established liver cirrhosis.

PubMed

Neef, Markus; Ledermann, Monika; Saegesser, Hans; Schneider, Vreni; Reichen, Juerg

2006-12-01

Mammalian target of rapamycin (mTOR) signalling is central in the activation of hepatic stellate cells (HSCs), the key source of extracellular matrix (ECM) in fibrotic liver. We tested the therapeutic potential of the mTOR inhibitor rapamycin in advanced cirrhosis. Cirrhosis was induced by bile duct-ligation (BDL) or thioacetamide injections (TAA). Rats received oral rapamycin (0.5 mg/kg/day) for either 14 or 28 days. Untreated BDL and TAA-rats served as controls. Liver function was quantified by aminopyrine breath test. ECM and ECM-producing cells were quantified by morphometry. MMP-2 activity was measured by zymography. mRNA expression of procollagen-alpha1, transforming growth factor-beta1 (TGF-beta1) and beta2 was quantified by RT-PCR. Fourteen days of rapamycin improved liver function. Accumulation of ECM was decreased together with numbers of activated HSCs and MMP-2 activity in both animal models. TGF-beta1 mRNA was downregulated in TAA, TGF-beta2 mRNA was downregulated in BDL. 28 days of rapamycin treatment entailed a survival advantage of long-term treated BDL-rats. Low-dose rapamycin treatment is effectively antifibrotic and attenuates disease progression in advanced fibrosis. Our results warrant the clinical evaluation of rapamycin as an antifibrotic drug.

Tree-mycorrhizal associations detected remotely from canopy spectral properties.

PubMed

Fisher, Joshua B; Sweeney, Sean; Brzostek, Edward R; Evans, Tom P; Johnson, Daniel J; Myers, Jonathan A; Bourg, Norman A; Wolf, Amy T; Howe, Robert W; Phillips, Richard P

2016-07-01

A central challenge in global ecology is the identification of key functional processes in ecosystems that scale, but do not require, data for individual species across landscapes. Given that nearly all tree species form symbiotic relationships with one of two types of mycorrhizal fungi - arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi - and that AM- and ECM-dominated forests often have distinct nutrient economies, the detection and mapping of mycorrhizae over large areas could provide valuable insights about fundamental ecosystem processes such as nutrient cycling, species interactions, and overall forest productivity. We explored remotely sensed tree canopy spectral properties to detect underlying mycorrhizal association across a gradient of AM- and ECM-dominated forest plots. Statistical mining of reflectance and reflectance derivatives across moderate/high-resolution Landsat data revealed distinctly unique phenological signals that differentiated AM and ECM associations. This approach was trained and validated against measurements of tree species and mycorrhizal association across ~130 000 trees throughout the temperate United States. We were able to predict 77% of the variation in mycorrhizal association distribution within the forest plots (P < 0.001). The implications for this work move us toward mapping mycorrhizal association globally and advancing our understanding of biogeochemical cycling and other ecosystem processes. © 2016 John Wiley & Sons Ltd.

Electron Beam Sterilization Does Not Have a Detrimental Effect on the Ability of Extracellular Matrix Scaffolds to Support In Vivo Ligament Healing

PubMed Central

Proffen, Benedikt L.; Perrone, Gabriel S.; Fleming, Braden C.; Sieker, Jakob T.; Kramer, Joshua; Hawes, Michael L.; Badger, Gary J.; Murray, Martha M.

2015-01-01

Purpose Extra-cellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method, which effectively sterilizes the material without significantly impairing in vivo function, is desirable. Methods 16 Yorkshire pigs underwent ACL transection and were randomly assigned to bridge-enhanced ACL repair – primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold - with either 1) an aseptically processed ECM scaffold, or 2) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at eight weeks after surgery. Results Scaffolds treated with 15kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Conclusions Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. PMID:25676876

Late development of hagfish vertebral elements.

PubMed

Ota, Kinya G; Fujimoto, Satoko; Oisi, Yasuhiro; Kuratani, Shigeru

2013-05-01

It has been demonstrated recently that hagfishes, one of two groups of extant jawless vertebrates, have cartilaginous vertebral elements. Embryological and gene expression analyses have also shown that this group of animals develops a sclerotome, the potential primordium of the axial skeleton. However, it has not been shown unequivocally that the hagfish sclerotome truly differentiates into cartilage, because access to late-stage embryos and information about the cartilaginous extracellular matrix (ECM) are lacking for these animals. Here we investigated the expression patterns of the biglycan/decorin (BGN/DCN) gene in the inshore hagfish, Eptatretus burgeri. The homologue of this gene encodes the major noncollagenous component of the cartilaginous ECM among gnathostomes. We clearly identified the expression of this gene in adult vertebral tissues and in embryonic mesenchymal cells on the ventral aspect of the notochord. Taking into account that the sclerotome in the gnathostomes expresses BGN/DCN gene during the chondrogenesis, it is highly expected the hagfish BGN/DCN-positive mesenchymal cells are derived from the sclerotomes. We propose that hagfishes and gnathostomes share conserved developmental mechanisms not only in their somite differentiation, but also in chondrogenesis of their vertebral elements. Copyright © 2013 Wiley Periodicals, Inc.

Fabrication of type I collagen microcarrier using a microfluidic 3D T-junction device and its application for the quantitative analysis of cell-ECM interactions.

PubMed

Yoon, Junghyo; Kim, Jaehoon; Jeong, Hyo Eun; Sudo, Ryo; Park, Myung-Jin; Chung, Seok

2016-08-26

We presented a new quantitative analysis for cell and extracellular matrix (ECM) interactions, using cell-coated ECM hydrogel microbeads (hydrobeads) made of type I collagen. The hydrobeads can carry cells as three-dimensional spheroidal forms with an ECM inside, facilitating a direct interaction between the cells and ECM. The cells on hydrobeads do not have a hypoxic core, which opens the possibility for using as a cell microcarrier for bottom-up tissue reconstitution. This technique can utilize various types of cells, even MDA-MB-231 cells, which have weak cell-cell interactions and do not form spheroids in conventional spheroid culture methods. Morphological indices of the cell-coated hydrobead visually present cell-ECM interactions in a quantitative manner.

Substrate stress relaxation regulates cell spreading

NASA Astrophysics Data System (ADS)

Chaudhuri, Ovijit; Gu, Luo; Darnell, Max; Klumpers, Darinka; Bencherif, Sidi A.; Weaver, James C.; Huebsch, Nathaniel; Mooney, David J.

2015-02-01

Studies of cellular mechanotransduction have converged upon the idea that cells sense extracellular matrix (ECM) elasticity by gauging resistance to the traction forces they exert on the ECM. However, these studies typically utilize purely elastic materials as substrates, whereas physiological ECMs are viscoelastic, and exhibit stress relaxation, so that cellular traction forces exerted by cells remodel the ECM. Here we investigate the influence of ECM stress relaxation on cell behaviour through computational modelling and cellular experiments. Surprisingly, both our computational model and experiments find that spreading for cells cultured on soft substrates that exhibit stress relaxation is greater than cells spreading on elastic substrates of the same modulus, but similar to that of cells spreading on stiffer elastic substrates. These findings challenge the current view of how cells sense and respond to the ECM.

Disruption of the Aspergillus fumigatus ECM33 homologue results in rapid conidial germination, antifungal resistance and hypervirulence.

PubMed

Romano, Jacob; Nimrod, Guy; Ben-Tal, Nir; Shadkchan, Yona; Baruch, Koti; Sharon, Haim; Osherov, Nir

2006-07-01

The ECM33/SPS2 family of glycosylphosphatidylinositol-anchored proteins plays an important role in maintaining fungal cell wall integrity and virulence. However, the precise molecular role of these proteins is unknown. In this work, AfuEcm33, the gene encoding the ECM33 homologue in the important pathogenic fungus Aspergillus fumigatus, has been cloned and its function analysed. It is shown that disruption of AfuEcm33 results in rapid conidial germination, increased cell-cell adhesion, resistance to the antifungal agent caspofungin and increased virulence in an immunocompromised mouse model for disseminated aspergillosis. These results suggest that the protein encoded by AfuEcm33 is involved in key aspects of cell wall morphogenesis and plays an important role in A. fumigatus virulence.

One size does not fit all: developing a cell-specific niche for in vitro study of cell behavior.

PubMed

Marinkovic, Milos; Block, Travis J; Rakian, Rubie; Li, Qihong; Wang, Exing; Reilly, Matthew A; Dean, David D; Chen, Xiao-Dong

2016-01-01

For more than 100years, cells and tissues have been studied in vitro using glass and plastic surfaces. Over the last 10-20years, a great body of research has shown that cells are acutely sensitive to their local environment (extracellular matrix, ECM) which contains both chemical and physical cues that influence cell behavior. These observations suggest that modern cell culture systems, using tissue culture polystyrene (TCP) surfaces, may fail to reproduce authentic cell behavior in vitro, resulting in "artificial outcomes." In the current study, we use bone marrow (BM)- and adipose (AD)-derived stromal cells to prepare BM-ECM and AD-ECM, which are decellularized after synthesis by the cells, to mimic the cellular niche for each of these tissues. Each ECM was characterized for its ability to affect BM- and AD-mesenchymal stem cell (MSC) proliferation, as well as proliferation of three cancer cell lines (HeLa, MCF-7, and MDA-MB-231), modulate cell spreading, and direct differentiation relative to standard TCP surfaces. We found that both ECMs promoted the proliferation of MSCs, but that this effect was enhanced when the tissue-origin of the cells matched that of the ECM (i.e. BM-ECM promoted the proliferation of BM-MSCs over AD-MSCs, and vice versa). Moreover, BM- and AD-ECM were shown to preferentially direct MSC differentiation towards either osteogenic or adipogenic lineage, respectively, suggesting that the effects of the ECM were tissue-specific. Further, each ECM influenced cell morphology (i.e. circularity), irrespective of the origin of the MSCs, lending more support to the idea that effects were tissue specific. Interestingly, unlike MSCs, these ECMs did not promote the proliferation of the cancer cells. In an effort to further understand how these three culture substrates influence cell behavior, we evaluated the chemical (protein composition) and physical properties (architecture and mechanical) of the two ECMs. While many structural proteins (e.g. collagen and fibronectin) were found at equivalent levels in both BM- and AD-ECM, the architecture (i.e. fiber orientation; surface roughness) and physical properties (storage modulus, surface energy) of each were unique. These results, demonstrating differences in cell behavior when cultured on the three different substrates (BM- and AD-ECM and TCP) with differences in chemical and physical properties, provide evidence that the two ECMs may recapitulate specific elements of the native stem cell niche for bone marrow and adipose tissues. More broadly, it could be argued that ECMs, elaborated by cells ex vivo, serve as an ideal starting point for developing tissue-specific culture environments. In contrast to TCP, which relies on the "one size fits all" paradigm, native tissue-specific ECM may be a more rational model to approach engineering 3D tissue-specific culture systems to replicate the in vivo niche. We suggest that this approach will provide more meaningful information for basic research studies of cell behavior as well as cell-based therapeutics. Published by Elsevier B.V.

75 FR 42390 - Orders Finding That the PJM WH Real Time Peak Contract and PJM WH Real Time Off-Peak Contract...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

... commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act... with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs'') are traded--and treating ECMs in that category...

75 FR 42380 - Orders Finding That the SP-15 Financial Day-Ahead LMP Peak Contract and SP-15 Financial Day-Ahead...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

...Exchange, Inc. (``ICE''), an exempt commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity... with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs'') are traded--and treating ECMs in that category...

75 FR 42399 - Orders Finding That the PJM WH Real Time Peak Daily Contract, PJM WH Real Time Off-Peak Daily...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

...Exchange, Inc. (``ICE''), an exempt commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity... regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs'') are traded--and treating ECMs in...

* Tissue-Specific Extracellular Matrix Enhances Skeletal Muscle Precursor Cell Expansion and Differentiation for Potential Application in Cell Therapy.

PubMed

Zhang, Deying; Zhang, Yong; Zhang, Yuanyuan; Yi, Hualin; Wang, Zhan; Wu, Rongpei; He, Dawei; Wei, Guanghui; Wei, Shicheng; Hu, Yun; Deng, Junhong; Criswell, Tracy; Yoo, James; Zhou, Yu; Atala, Anthony

2017-08-01

Skeletal muscle precursor cells (MPCs) are considered a key candidate for cell therapy in the treatment of skeletal muscle dysfunction due to injury, disease, or age. However, expansion of a sufficient number of functional skeletal muscle cells in vitro from a small tissue biopsy has been challenging due to changes in phenotypic expression of these cells under traditional culture conditions. Thus, the aim of the study was to develop a better culture system for the expansion and myo-differentiation of MPCs that could further be used for therapy. For this purpose, we developed an ideal method of tissue decellularization and compared the ability of different matrices to support MPC growth and differentiation. Porcine-derived skeletal muscle and liver and kidney extracellular matrix (ECM) were generated by decellularization methods consisting of distilled water, 0.2 mg/mL DNase, or 5% fetal bovine serum. Acellular matrices were further homogenized, dissolved, and combined with a hyaluronic acid-based hydrogel decorated with heparin (ECM-HA-HP). The cell proliferation and myogenic differentiation capacity of human MPCs were assessed when grown on gel alone, ECM, or each ECM-HA-HP substrate. Human MPC proliferation was significantly enhanced when cultured on the ECM-HA-HP substrates compared to the other substrates tested, with the greatest proliferation on the muscle ECM-HA-HP (mECM-HA-HP) substrate. The number of differentiated myotubes was significantly increased on the mECM-HA-HP substrate compared to the other gel-ECM substrates, as well as the numbers of MPCs expressing specific myogenic cell markers (i.e., myosin, desmin, myoD, and myf5). In conclusion, skeletal mECM-HA-HP as a culture substrate provided an optimal culture microenvironment potentially due to its similarity to the in vivo environment. These data suggest a potential use of skeletal muscle-derived ECM gel for the expansion and differentiation of human MPCs for cell-based therapy for skeletal muscle dysfunction.

Decellularized extracellular matrices produced from immortal cell lines derived from different parts of the placenta support primary mesenchymal stem cell expansion

PubMed Central

Kusuma, Gina D.; Brennecke, Shaun P.; O’Connor, Andrea J.; Kalionis, Bill

2017-01-01

Mesenchymal stem/stromal cells (MSCs) exhibit undesired phenotypic changes during ex vivo expansion, limiting production of the large quantities of high quality primary MSCs needed for both basic research and cell therapies. Primary MSCs retain many desired MSC properties including proliferative capacity and differentiation potential when expanded on decellularized extracellular matrix (dECM) prepared from primary MSCs. However, the need to use low passage number primary MSCs (passage 3 or lower) to produce the dECM drastically limits the utility and impact of this technology. Here, we report that primary MSCs expanded on dECM prepared from high passage number (passage 25) human telomerase reverse transcriptase (hTERT) transduced immortal MSC cell lines also exhibit increased proliferation and osteogenic differentiation. Two hTERT-transduced placenta-derived MSC cell lines, CMSC29 and DMSC23 [derived from placental chorionic villi (CMSCs) and decidua basalis (DMSCs), respectively], were used to prepare dECM-coated substrates. These dECM substrates showed structural and biochemical differences. Primary DMSCs cultured on dECM-DMSC23 showed a three-fold increase in cell number after 14 days expansion in culture and increased osteogenic differentiation compared with controls. Primary CMSCs cultured on the dECM-DMSC23 exhibited a two-fold increase in cell number and increased osteogenic differentiation. We conclude that immortal MSC cell lines derived from different parts of the placenta produce dECM with varying abilities for supporting increased primary MSC expansion while maintaining important primary MSC properties. Additionally, this is the first demonstration of using high passage number cells to produce dECM that can promote primary MSC expansion, and this advancement greatly increases the feasibility and applicability of dECM-based technologies. PMID:28152107

Comparison of three methods for the derivation of a biologic scaffold composed of adipose tissue extracellular matrix.

PubMed

Brown, Bryan N; Freund, John M; Han, Li; Rubin, J Peter; Reing, Janet E; Jeffries, Eric M; Wolf, Mathew T; Tottey, Stephen; Barnes, Christopher A; Ratner, Buddy D; Badylak, Stephen F

2011-04-01

Extracellular matrix (ECM)-based scaffold materials have been used successfully in both preclinical and clinical tissue engineering and regenerative medicine approaches to tissue reconstruction. Results of numerous studies have shown that ECM scaffolds are capable of supporting the growth and differentiation of multiple cell types in vitro and of acting as inductive templates for constructive tissue remodeling after implantation in vivo. Adipose tissue represents a potentially abundant source of ECM and may represent an ideal substrate for the growth and adipogenic differentiation of stem cells harvested from this tissue. Numerous studies have shown that the methods by which ECM scaffold materials are prepared have a dramatic effect upon both the biochemical and structural properties of the resultant ECM scaffold material as well as the ability of the material to support a positive tissue remodeling outcome after implantation. The objective of the present study was to characterize the adipose ECM material resulting from three methods of decellularization to determine the most effective method for the derivation of an adipose tissue ECM scaffold that was largely free of potentially immunogenic cellular content while retaining tissue-specific structural and functional components as well as the ability to support the growth and adipogenic differentiation of adipose-derived stem cells. The results show that each of the decellularization methods produced an adipose ECM scaffold that was distinct from both a structural and biochemical perspective, emphasizing the importance of the decellularization protocol used to produce adipose ECM scaffolds. Further, the results suggest that the adipose ECM scaffolds produced using the methods described herein are capable of supporting the maintenance and adipogenic differentiation of adipose-derived stem cells and may represent effective substrates for use in tissue engineering and regenerative medicine approaches to soft tissue reconstruction.

Decellularized extracellular matrices produced from immortal cell lines derived from different parts of the placenta support primary mesenchymal stem cell expansion.

PubMed

Kusuma, Gina D; Brennecke, Shaun P; O'Connor, Andrea J; Kalionis, Bill; Heath, Daniel E

2017-01-01

Mesenchymal stem/stromal cells (MSCs) exhibit undesired phenotypic changes during ex vivo expansion, limiting production of the large quantities of high quality primary MSCs needed for both basic research and cell therapies. Primary MSCs retain many desired MSC properties including proliferative capacity and differentiation potential when expanded on decellularized extracellular matrix (dECM) prepared from primary MSCs. However, the need to use low passage number primary MSCs (passage 3 or lower) to produce the dECM drastically limits the utility and impact of this technology. Here, we report that primary MSCs expanded on dECM prepared from high passage number (passage 25) human telomerase reverse transcriptase (hTERT) transduced immortal MSC cell lines also exhibit increased proliferation and osteogenic differentiation. Two hTERT-transduced placenta-derived MSC cell lines, CMSC29 and DMSC23 [derived from placental chorionic villi (CMSCs) and decidua basalis (DMSCs), respectively], were used to prepare dECM-coated substrates. These dECM substrates showed structural and biochemical differences. Primary DMSCs cultured on dECM-DMSC23 showed a three-fold increase in cell number after 14 days expansion in culture and increased osteogenic differentiation compared with controls. Primary CMSCs cultured on the dECM-DMSC23 exhibited a two-fold increase in cell number and increased osteogenic differentiation. We conclude that immortal MSC cell lines derived from different parts of the placenta produce dECM with varying abilities for supporting increased primary MSC expansion while maintaining important primary MSC properties. Additionally, this is the first demonstration of using high passage number cells to produce dECM that can promote primary MSC expansion, and this advancement greatly increases the feasibility and applicability of dECM-based technologies.

DEVELOPMENT OF TECHNIQUES FOR EDDY-CORRELATION MEASUREMENTS OF NON-METHANE VOLATILE ORGANIC COMPOUND FLUXED IN THE ATMOSPHERE

EPA Science Inventory

An analytical technique for the measurement of the exchange (flux) of trace gases between the earth's surface and the atmosphere will be developed. Measurements will rely on the eddy correlation method (ECM). Target compounds are biogenically and anthropogenically emitted v...

An assessment of ectomycorrhizal fungal communities in Tasmanian temperate high-altitude Eucalyptus delegatensis forest reveals a dominance of the Cortinariaceae.

PubMed

Horton, Bryony M; Glen, Morag; Davidson, Neil J; Ratkowsky, David A; Close, Dugald C; Wardlaw, Tim J; Mohammed, Caroline

2017-01-01

Fungal diversity of Australian eucalypt forests remains underexplored. We investigated the ectomycorrhizal (EcM) fungal community characteristics of declining temperate eucalypt forests in Tasmania. Within this context, we explored the diversity of EcM fungi of two forest types in the northern highlands in the east and west of the island. We hypothesised that EcM fungal community richness and composition would differ between forest type but that the Cortinariaceae would be the dominant family irrespective of forest type. We proposed that EcM richness would be greater in the wet sclerophyll forest than the dry sclerophyll forest type. Using both sporocarps and EcM fungi from root tips amplified by PCR and sequenced in the rDNA ITS region, 175 EcM operational taxonomic units were identified of which 97 belonged to the Cortinariaceae. The Cortinariaceae were the most diverse family, in both the above and below ground communities. Three distinct fungal assemblages occurred within the wet and dry sclerophyll forest types and two geographic regions that were studied, although this pattern did not remain when only the root tip data were analysed. EcM sporocarp richness was unusually higher than root tip richness and EcM richness did not significantly differ among forest types. The results are discussed in relation to the importance of the Cortinariaceae and the drivers of EcM fungal community composition within these forests.

Enabling screening in 3D microenvironments: probing matrix and stromal effects on the morphology and proliferation of T47D breast carcinoma cells.

PubMed

Montanez-Sauri, Sara I; Sung, Kyung Eun; Berthier, Erwin; Beebe, David J

2013-03-01

During breast carcinoma progression, the three-dimensional (3D) microenvironment is continuously remodeled, and changes in the composition of the extracellular matrix (ECM) occur. High throughput screening platforms have been used to decipher the complexity of the microenvironment and to identify ECM components responsible for cancer progression. However, traditional screening platforms are typically limited to two-dimensional (2D) cultures, and often exclude the influence of ECM and stromal components. In this work, a system that integrates 3-dimensional cell culture techniques with an automated microfluidic platform was used to create a new ECM screening platform that cultures cells in more physiologically relevant 3D in vitro microenvironments containing stromal cells and different ECM molecules. This new ECM screening platform was used to culture T47D breast carcinoma cells in mono- and co-culture with human mammary fibroblasts (HMF) with seven combinations of three different ECM proteins (collagen, fibronectin, laminin). Differences in the morphology of T47D clusters, and the proliferation of T47D cells were found in ECM compositions rich in fibronectin or laminin. In addition, an MMP enzyme activity inhibition screening showed the capabilities of the platform for small molecule screening. The platform presented in this work enables screening for the effects of matrix and stromal compositions and show promises for providing new insights in the identification of key ECM components involved in breast cancer.

Osteoblasts extracellular matrix induces vessel like structures through glycosylated collagen I

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

Palmieri, D.; Valli, M.; Viglio, S.

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 ofmore » 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.« less

Heterogeneity of Focal Adhesions and Focal Contacts in Motile Fibroblasts.

PubMed

Gladkikh, Aleena; Kovaleva, Anastasia; Tvorogova, Anna; Vorobjev, Ivan A

2018-01-01

Cell-extracellular matrix (ECM) adhesion is an important property of virtually all cells in multicellular organisms. Cell-ECM adhesion studies, therefore, are very significant both for biology and medicine. Over the last three decades, biomedical studies resulted in a tremendous advance in our understanding of the molecular basis and functions of cell-ECM adhesion. Based on morphological and molecular criteria, several different types of model cell-ECM adhesion structures including focal adhesions, focal complexes, fibrillar adhesions, podosomes, and three-dimensional matrix adhesions have been described. All the subcellular structures that mediate cell-ECM adhesion are quite heterogeneous, often varying in size, shape, distribution, dynamics, and, to a certain extent, molecular constituents. The morphological "plasticity" of cell-ECM adhesion perhaps reflects the needs of cells to sense, adapt, and respond to a variety of extracellular environments. In addition, cell type (e.g., differentiation status, oncogenic transformation, etc.) often exerts marked influence on the structure of cell-ECM adhesions. Although molecular, genetic, biochemical, and structural studies provide important maps or "snapshots" of cell-ECM adhesions, the area of research that is equally valuable is to study the heterogeneity of FA subpopulations within cells. Recently time-lapse observations on the FA dynamics become feasible, and behavior of individual FA gives additional information on cell-ECM interactions. Here we describe a robust method of labeling of FA using plasmids with fluorescent markers for paxillin and vinculin and quantifying the morphological and dynamical parameters of FA.

Applications and limitations of electron correlation microscopy to study relaxation dynamics in supercooled liquids

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

Zhang, Pei; He, Li; Besser, Matthew F.

Here, electron correlation microscopy (ECM) is a way to measure structural relaxation times, τ, of liquids with nanometer-scale spatial resolution using coherent electron scattering equivalent of photon correlation spectroscopy. We have applied ECM with a 3.5 nm diameter probe to Pt 57.5Cu 14.7Ni 5.3P 22.5 amorphous nanorods and Pd 40Ni 40P 20 bulk metallic glass (BMG) heated inside the STEM into the supercooled liquid region. These data demonstrate that the ECM technique is limited by the characteristics of the time series, which must be at least 40τ to obtain a well-converged correlation function g 2(t), and the time per frame,more » which must be less than 0.1τ to obtain sufficient sampling. A high-speed direct electron camera enables fast acquisition and affords reliable g 2(t) data even with low signal per frame.« less

Applications and limitations of electron correlation microscopy to study relaxation dynamics in supercooled liquids

DOE PAGES

Zhang, Pei; He, Li; Besser, Matthew F.; ...

2016-09-08

Here, electron correlation microscopy (ECM) is a way to measure structural relaxation times, τ, of liquids with nanometer-scale spatial resolution using coherent electron scattering equivalent of photon correlation spectroscopy. We have applied ECM with a 3.5 nm diameter probe to Pt 57.5Cu 14.7Ni 5.3P 22.5 amorphous nanorods and Pd 40Ni 40P 20 bulk metallic glass (BMG) heated inside the STEM into the supercooled liquid region. These data demonstrate that the ECM technique is limited by the characteristics of the time series, which must be at least 40τ to obtain a well-converged correlation function g 2(t), and the time per frame,more » which must be less than 0.1τ to obtain sufficient sampling. A high-speed direct electron camera enables fast acquisition and affords reliable g 2(t) data even with low signal per frame.« less

Biofilm-specific extracellular matrix proteins of non-typeable Haemophilus influenzae

PubMed Central

Wu, Siva; Baum, Marc M.; Kerwin, James; Guerrero-Given, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

2014-01-01

Non-typeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24 hr and 96 hr NTHi biofilms contained polysaccharides and proteinaceous components as detected by NMR and FTIR spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24 hr biofilms, two were found only in 96 hr biofilms, and fifteen were present in the ECM of both 24 hr and 96 hr NTHi biofilms. All proteins identified were either associated with bacterial membranes or were cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. PMID:24942343

Effects of Ethanol on Brain Extracellular Matrix: Implications for Alcohol Use Disorder.

PubMed

Lasek, Amy W

2016-10-01

The brain extracellular matrix (ECM) occupies the space between cells and is involved in cell-matrix and cell-cell adhesion. However, in addition to providing structural support to brain tissue, the ECM activates cell signaling and controls synaptic transmission. The expression and activity of brain ECM components are regulated by alcohol exposure. This review will discuss what is currently known about the effects of alcohol on the activity and expression of brain ECM components. An interpretation of how these changes might promote alcohol use disorder (AUD) will be also provided. Ethanol (EtOH) exposure decreases levels of structural proteins involved in the interstitial matrix and basement membrane, with a concomitant increase in proteolytic enzymes that degrade these components. In contrast, EtOH exposure generally increases perineuronal net components. Because the ECM has been shown to regulate both synaptic plasticity and behavioral responses to drugs of abuse, regulation of the brain ECM by alcohol may be relevant to the development of alcoholism. Although investigation of the function of brain ECM in alcohol abuse is still in early stages, a greater understanding of the interplay between ECM and alcohol might lead to novel therapeutic strategies for treating AUD. Copyright © 2016 by the Research Society on Alcoholism.

A novel culture device for the evaluation of three-dimensional extracellular matrix materials.

PubMed

Akhyari, Payam; Ziegler, Heiko; Gwanmesia, Patricia; Barth, Mareike; Schilp, Soeren; Huelsmann, Joern; Hoffmann, Stefanie; Bosch, Julia; Kögler, Gesine; Lichtenberg, Artur

2014-09-01

Cell-matrix interactions in a three-dimensional (3D) extracellular matrix (ECM) are of fundamental importance in living tissue, and their in vitro reconstruction in bioartificial structures represents a core target of contemporary tissue engineering concepts. For a detailed analysis of cell-matrix interaction under highly controlled conditions, we developed a novel ECM evaluation culture device (EECD) that allows for a precisely defined surface-seeding of 3D ECM scaffolds, irrespective of their natural geometry. The effectiveness of EECD was evaluated in the context of heart valve tissue engineering. Detergent decellularized pulmonary cusps were mounted in EECD and seeded with endothelial cells (ECs) to study EC adhesion, morphology and function on a 3D ECM after 3, 24, 48 and 96 h. Standard EC monolayers served as controls. Exclusive top-surface-seeding of 3D ECM by viable ECs was demonstrated by laser scanning microscopy (LSM), resulting in a confluent re-endothelialization of the ECM after 96 h. Cell viability and protein expression, as demonstrated by MTS assay and western blot analysis (endothelial nitric oxide synthase, von Willebrand factor), were preserved at maintained levels over time. In conclusion, EECD proves as a highly effective system for a controlled repopulation and in vitro analysis of cell-ECM interactions in 3D ECM. Copyright © 2012 John Wiley & Sons, Ltd.

Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

PubMed

Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

2017-02-01

Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Electronic case management with homeless youth.

PubMed

Bender, Kimberly; Schau, Nicholas; Begun, Stephanie; Haffejee, Badiah; Barman-Adhikari, Anamika; Hathaway, Jessica

2015-06-01

Case management, a widely practiced form of service brokerage, is associated with a variety of positive outcomes for homeless youth, but it may be difficult to implement, as youth face logistical barriers to attending in-person meetings. As part of a larger clinical trial, the current study investigates the feasibility of providing electronic case management (ECM) to homeless youth, using cell-phones, texts, email, and Facebook. Youth were given prepaid cell-phones and a case manager who provided four ECM sessions every 2-3 weeks over a 3-month period. Contact logs were used to record how many youth engaged in ECM, how many attempts were necessary to elicit engagement, and youths' preferred technology methods for engaging. Although engagement in the number of ECM sessions varied, the majority of youth (87.5%) engaged in at least one ECM session. Youth (41%) most commonly needed one contact before they engaged in an ECM session, and the majority responded by the third attempt. While youth most commonly answered calls directly, their chosen method of returning calls was texting. The majority of youth (80%) described ECM positively, reporting themes of convenience, connection, and accountability. The use of ECM, particularly of texting, offers promising implications for providing services to homeless youth. Copyright © 2015 Elsevier Ltd. All rights reserved.

Smooth muscle cell biglycan overexpression results in increased lipoprotein retention on extracellular matrix: implications for the retention of lipoproteins in atherosclerosis.

PubMed

O'Brien, Kevin D; Lewis, Katherine; Fischer, Jens W; Johnson, Pamela; Hwang, Jin-Yong; Knopp, Eleanor A; Kinsella, Michael G; Barrett, P Hugh R; Chait, Alan; Wight, Thomas N

2004-11-01

Lipoprotein retention on extracellular matrix (ECM) may play a central role in atherogenesis, and a specific extracellular matrix proteoglycan, biglycan, has been implicated in lipoprotein retention in human atherosclerosis. To test whether increased cellular biglycan expression results in increased retention of lipoproteins on ECM, rat aortic smooth muscle cells (SMCs) were transduced with a human biglycan cDNA-containing retroviral vector (LBSN) or with an empty retroviral vector (LXSN). To assess the importance of biglycan's glycosaminoglycan side chains in lipoprotein retention, ECM binding studies were also performed using RASMCs transduced with a retroviral vector encoding for a mutant, glycosaminoglycan-deficient biglycan (LBmutSN). Human biglycan mRNA and protein were confirmed in LBSN and LBmutSN RASMCs by Northern and Western blot analyses. HDL3+E binding to SMC ECM was increased significantly (as determined by 95% confidence intervals for binding curves) for LBSN as compared to either LXSN or LBmutSN cells; the increases for LBSN cell ECM were due primarily to an approximately 50% increase in binding sites (increased Bmax) versus LXSN cell ECM and of approximately 25% versus LBmutSN cell ECM. These results are consistent with the hypothesis that biglycan, through its glycosaminoglycan side chains, may mediate lipoprotein retention on atherosclerotic plaque ECM.

Engineering a clinically-useful matrix for cell therapy.

PubMed

Prestwich, Glenn D

2008-01-01

The design criteria for matrices for encapsulation of cells for cell therapy include chemical, biological, engineering, marketing, regulatory, and financial constraints. What is required is a biocompatible material for culture of cells in three-dimensions (3-D) that offers ease of use, experimental flexibility to alter composition and compliance, and a composition that would permit a seamless transition from in vitro to in vivo use. The challenge is to replicate the complexity of the native extracellular matrix (ECM) environment with the minimum number of components necessary to allow cells to rebuild a given tissue. Our approach is to deconstruct the ECM to a few modular components that can be reassembled into biomimetic materials that meet these criteria. These semi-synthetic ECMs (sECMs) employ thiol-modified derivatives of hyaluronic acid (HA) that can form covalently crosslinked, biodegradable hydrogels. These sECMs are "living" biopolymers, meaning that they can be crosslinked in the presence of cells or tissues to enable cell therapy and tissue engineering. Moreover, the sECMs allow inclusion of the appropriate biological cues needed to simulate the complexity of the ECM of a given tissue. Taken together, the sECM technology offers a manufacturable, highly reproducible, flexible, FDA-approvable, and affordable vehicle for cell expansion and differentiation in 3-D.

Stretching the boundaries of extracellular matrix research.

PubMed

Hynes, Richard O

2014-12-01

Extracellular matrix (ECM) proteins constitute >1% of the proteome and interact with many modifiers and growth factors to affect most aspects of cellular behaviour during development and normal physiology, as well as in diseases such as fibroses, cancer and many genetic disorders. In addition to biochemical signals provided to cells by ECM proteins, important cell–ECM interactions involve bidirectional mechanotransduction influences, which are dependent on the physical structure and organization of the ECM. These are beginning to be understood using twenty-first-century approaches, including biophysics, nanotechnology, biological engineering and modern microscopy. Articles in this issue of Nature Reviews Molecular Cell Biology review progress in our understanding of the ECM.

FAP-overexpressing fibroblasts produce an extracellular matrix that enhances invasive velocity and directionality of pancreatic cancer cells.

PubMed

Lee, Hyung-Ok; Mullins, Stefanie R; Franco-Barraza, Janusz; Valianou, Matthildi; Cukierman, Edna; Cheng, Jonathan D

2011-06-13

Alterations towards a permissive stromal microenvironment provide important cues for tumor growth, invasion, and metastasis. In this study, Fibroblast activation protein (FAP), a serine protease selectively produced by tumor-associated fibroblasts in over 90% of epithelial tumors, was used as a platform for studying tumor-stromal interactions. We tested the hypothesis that FAP enzymatic activity locally modifies stromal ECM (extracellular matrix) components thus facilitating the formation of a permissive microenvironment promoting tumor invasion in human pancreatic cancer. We generated a tetracycline-inducible FAP overexpressing fibroblastic cell line to synthesize an in vivo-like 3-dimensional (3D) matrix system which was utilized as a stromal landscape for studying matrix-induced cancer cell behaviors. A FAP-dependent topographical and compositional alteration of the ECM was characterized by measuring the relative orientation angles of fibronectin fibers and by Western blot analyses. The role of FAP in the matrix-induced permissive tumor behavior was assessed in Panc-1 cells in assorted matrices by time-lapse acquisition assays. Also, FAP+ matrix-induced regulatory molecules in cancer cells were determined by Western blot analyses. We observed that FAP remodels the ECM through modulating protein levels, as well as through increasing levels of fibronectin and collagen fiber organization. FAP-dependent architectural/compositional alterations of the ECM promote tumor invasion along characteristic parallel fiber orientations, as demonstrated by enhanced directionality and velocity of pancreatic cancer cells on FAP+ matrices. This phenotype can be reversed by inhibition of FAP enzymatic activity during matrix production resulting in the disorganization of the ECM and impeded tumor invasion. We also report that the FAP+ matrix-induced tumor invasion phenotype is β1-integrin/FAK mediated. Cancer cell invasiveness can be affected by alterations in the tumor microenvironment. Disruption of FAP activity and β1-integrins may abrogate the invasive capabilities of pancreatic and other tumors by disrupting the FAP-directed organization of stromal ECM and blocking β1-integrin dependent cell-matrix interactions. This provides a novel preclinical rationale for therapeutics aimed at interfering with the architectural organization of tumor-associated ECM. Better understanding of the stromal influences that fuel progressive tumorigenic behaviors may allow the effective future use of targeted therapeutics aimed at disrupting specific tumor-stromal interactions. © 2011 Lee et al; licensee BioMed Central Ltd.

FAP-overexpressing fibroblasts produce an extracellular matrix that enhances invasive velocity and directionality of pancreatic cancer cells

PubMed Central

2011-01-01

Background Alterations towards a permissive stromal microenvironment provide important cues for tumor growth, invasion, and metastasis. In this study, Fibroblast activation protein (FAP), a serine protease selectively produced by tumor-associated fibroblasts in over 90% of epithelial tumors, was used as a platform for studying tumor-stromal interactions. We tested the hypothesis that FAP enzymatic activity locally modifies stromal ECM (extracellular matrix) components thus facilitating the formation of a permissive microenvironment promoting tumor invasion in human pancreatic cancer. Methods We generated a tetracycline-inducible FAP overexpressing fibroblastic cell line to synthesize an in vivo-like 3-dimensional (3D) matrix system which was utilized as a stromal landscape for studying matrix-induced cancer cell behaviors. A FAP-dependent topographical and compositional alteration of the ECM was characterized by measuring the relative orientation angles of fibronectin fibers and by Western blot analyses. The role of FAP in the matrix-induced permissive tumor behavior was assessed in Panc-1 cells in assorted matrices by time-lapse acquisition assays. Also, FAP+ matrix-induced regulatory molecules in cancer cells were determined by Western blot analyses. Results We observed that FAP remodels the ECM through modulating protein levels, as well as through increasing levels of fibronectin and collagen fiber organization. FAP-dependent architectural/compositional alterations of the ECM promote tumor invasion along characteristic parallel fiber orientations, as demonstrated by enhanced directionality and velocity of pancreatic cancer cells on FAP+ matrices. This phenotype can be reversed by inhibition of FAP enzymatic activity during matrix production resulting in the disorganization of the ECM and impeded tumor invasion. We also report that the FAP+ matrix-induced tumor invasion phenotype is β1-integrin/FAK mediated. Conclusion Cancer cell invasiveness can be affected by alterations in the tumor microenvironment. Disruption of FAP activity and β1-integrins may abrogate the invasive capabilities of pancreatic and other tumors by disrupting the FAP-directed organization of stromal ECM and blocking β1-integrin dependent cell-matrix interactions. This provides a novel preclinical rationale for therapeutics aimed at interfering with the architectural organization of tumor-associated ECM. Better understanding of the stromal influences that fuel progressive tumorigenic behaviors may allow the effective future use of targeted therapeutics aimed at disrupting specific tumor-stromal interactions. PMID:21668992

Cell-ECM Interactions During Cancer Invasion

NASA Astrophysics Data System (ADS)

Jiang, Yi

The extracellular matrix (ECM), a fibrous material that forms a network in a tissue, significantly affects many aspects of cellular behavior, including cell movement and proliferation. Transgenic mouse tumor studies indicate that excess collagen, a major component of ECM, enhances tumor formation and invasiveness. Clinically, tumor associated collagen signatures are strong markers for breast cancer survival. However, the underlying mechanisms are unclear since the properties of ECM are complex, with diverse structural and mechanical properties depending on various biophysical parameters. We have developed a three-dimensional elastic fiber network model, and parameterized it with in vitro collagen mechanics. Using this model, we study ECM remodeling as a result of local deformation and cell migration through the ECM as a network percolation problem. We have also developed a three-dimensional, multiscale model of cell migration and interaction with ECM. Our model reproduces quantitative single cell migration experiments. This model is a first step toward a fully biomechanical cell-matrix interaction model and may shed light on tumor associated collagen signatures in breast cancer. This work was partially supported by NIH-U01CA143069.

Effect of ECM2 expression on bovine skeletal muscle-derived satellite cell differentiation.

PubMed

Liu, Chang; Tong, Huili; Li, Shufeng; Yan, Yunqin

2018-05-01

Extracellular matrix components have important regulatory functions during cell proliferation and differentiation. In recent study, extracellular matrix were shown to have a strong effect on skeletal muscle differentiation. Here, we aimed to elucidate the effects of extracellular matrix protein 2 (ECM2), an extracellular matrix component, on the differentiation of bovine skeletal muscle-derived satellite cells (MDSCs). Western blot and immunofluorescence analyses were used to elucidate the ECM2 expression pattern in bovine MDSCs during differentiation in vitro. CRISPR/Cas9 technology was used to activate or inhibit ECM2 expression to study its effects on the in vitro differentiation of bovine MDSCs. ECM2 expression was shown to increase gradually during bovine MDSC differentiation, and the levels of this protein were higher in more highly differentiated myotubes. ECM2 activation promoted MDSC differentiation, whereas its suppression inhibited the differentiation of these cells. Here, for the first time, we demonstrated the importance of ECM2 expression during bovine MDSC differentiation; these results could lead to treatments that help to increase beef cattle muscularity. © 2018 International Federation for Cell Biology.

Methods for the visualization and analysis of extracellular matrix protein structure and degradation.

PubMed

Leonard, Annemarie K; Loughran, Elizabeth A; Klymenko, Yuliya; Liu, Yueying; Kim, Oleg; Asem, Marwa; McAbee, Kevin; Ravosa, Matthew J; Stack, M Sharon

2018-01-01

This chapter highlights methods for visualization and analysis of extracellular matrix (ECM) proteins, with particular emphasis on collagen type I, the most abundant protein in mammals. Protocols described range from advanced imaging of complex in vivo matrices to simple biochemical analysis of individual ECM proteins. The first section of this chapter describes common methods to image ECM components and includes protocols for second harmonic generation, scanning electron microscopy, and several histological methods of ECM localization and degradation analysis, including immunohistochemistry, Trichrome staining, and in situ zymography. The second section of this chapter details both a common transwell invasion assay and a novel live imaging method to investigate cellular behavior with respect to collagen and other ECM proteins of interest. The final section consists of common electrophoresis-based biochemical methods that are used in analysis of ECM proteins. Use of the methods described herein will enable researchers to gain a greater understanding of the role of ECM structure and degradation in development and matrix-related diseases such as cancer and connective tissue disorders. © 2018 Elsevier Inc. All rights reserved.

Performance of some diagnostic systems in the prediction of occlusal caries in permanent molars in 6- and 11-year-old children.

PubMed

Fennis-Ie, Y L; Verdonschot, E H; van't Hof, M A

1998-01-01

Attempts have been made to develop diagnostic methods which enable an early diagnosis of occlusal lesions which are not detectable by visual inspection. The aim of this study was to compare the performance of visual inspection focused on finding signs of fissure decalcification and discoloration, visual inspection upon fibre-optic transillumination (FOTI), and electrical conductance measurements (ECMs) in predicting the onset of occlusal caries in 6- and 11-year-old children. Fifty children aged 5-7 and 11-15 years, having first or second permanent molar teeth that were not exposed to the oral environment for more than half a year, participated in the study. Following baseline data recording, the diagnostic measurements were repeated six times at 6-month intervals over a period of 2.5 years. Data were collected at predefined sites in the fissures. During the study, 220 of the 652 sites, i.e. 75 of 197 molars in 31 of the 50 children were judged to require a sealant or a sealant restoration. Two examiners jointly decided on the decay status at the sites. Survival plots showed that ECMs were superior to FOTI and fissure discoloration in predicting the onset of occlusal caries, although the differences were small. ECM is a better predictor of occlusal caries than fissure discoloration and FOTI, although the differences among the performance of the three methods in this study were very small. A cost-effective analysis is envisaged to obtain insight into the practical value of ECMs in the prediction of occlusal caries and, thus, into the effectiveness of sealant application.

Cardiac fibrosis and dysfunction in experimental diabetic cardiomyopathy are ameliorated by alpha-lipoic acid.

PubMed

Li, Chun-jun; Lv, Lin; Li, Hui; Yu, De-min

2012-06-19

Alpha-lipoic acid (ALA), a naturally occurring compound, exerts powerful protective effects in various cardiovascular disease models. However, its role in protecting against diabetic cardiomyopathy (DCM) has not been elucidated. In this study, we have investigated the effects of ALA on cardiac dysfunction, mitochondrial oxidative stress (MOS), extracellular matrix (ECM) remodeling and interrelated signaling pathways in a diabetic rat model. Diabetes was induced in rats by I.V. injection of streptozotocin (STZ) at 45 mg/kg. The animals were randomly divided into 4 groups: normal groups with or without ALA treatment, and diabetes groups with or without ALA treatment. All studies were carried out 11 weeks after induction of diabetes. Cardiac catheterization was performed to evaluate cardiac function. Mitochondrial oxidative biochemical parameters were measured by spectophotometeric assays. Extracellular matrix content (total collagen, type I and III collagen) was assessed by staining with Sirius Red. Gelatinolytic activity of Pro- and active matrix metalloproteinase-2 (MMP-2) levels were analyzed by a zymogram. Cardiac fibroblasts differentiation to myofibroblasts was evaluated by Western blot measuring smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β). Key components of underlying signaling pathways including the phosphorylation of c-Jun N-terminal kinase (JNK), p38 MAPK and ERK were also assayed by Western blot. DCM was successfully induced by the injection of STZ as evidenced by abnormal heart mass and cardiac function, as well as the imbalance of ECM homeostasis. After administration of ALA, left ventricular dysfunction greatly improved; interstitial fibrosis also notably ameliorated indicated by decreased collagen deposition, ECM synthesis as well as enhanced ECM degradation. To further assess the underlying mechanism of improved DCM by ALA, redox status and cardiac remodeling associated signaling pathway components were evaluated. It was shown that redox homeostasis was disturbed and MAPK signaling pathway components activated in STZ-induced DCM animals. While ALA treatment favorably shifted redox homeostasis and suppressed JNK and p38 MAPK activation. These results, coupled with the excellent safety and tolerability profile of ALA in humans, demonstrate that ALA may have therapeutic potential in the treatment of DCM by attenuating MOS, ECM remodeling and JNK, p38 MAPK activation.

FK506 protects against articular cartilage collagenous extra-cellular matrix degradation.

PubMed

Siebelt, M; van der Windt, A E; Groen, H C; Sandker, M; Waarsing, J H; Müller, C; de Jong, M; Jahr, H; Weinans, H

2014-04-01

Osteoarthritis (OA) is a non-rheumatologic joint disease characterized by progressive degeneration of the cartilage extra-cellular matrix (ECM), enhanced subchondral bone remodeling, activation of synovial macrophages and osteophyte growth. Inhibition of calcineurin (Cn) activity through tacrolimus (FK506) in in vitro monolayer chondrocytes exerts positive effects on ECM marker expression. This study therefore investigated the effects of FK506 on anabolic and catabolic markers of osteoarthritic chondrocytes in 2D and 3D in vitro cultures, and its therapeutic effects in an in vivo rat model of OA. Effects of high and low doses of FK506 on anabolic (QPCR/histochemistry) and catabolic (QPCR) markers were evaluated in vitro on isolated (2D) and ECM-embedded chondrocytes (explants, 3D pellets). Severe cartilage damage was induced unilaterally in rat knees using papain injections in combination with a moderate running protocol. Twenty rats were treated with FK506 orally and compared to twenty untreated controls. Subchondral cortical and trabecular bone changes (longitudinal microCT) and macrophage activation (SPECT/CT) were measured. Articular cartilage was analyzed ex vivo using contrast enhanced microCT and histology. FK506 treatment of osteoarthritic chondrocytes in vitro induced anabolic (mainly collagens) and reduced catabolic ECM marker expression. In line with this, FK506 treatment clearly protected ECM integrity in vivo by markedly decreasing subchondral sclerosis, less development of subchondral pores, depletion of synovial macrophage activation and lower osteophyte growth. FK506 protected cartilage matrix integrity in vitro and in vivo. Additionally, FK506 treatment in vivo reduced OA-like responses in different articular joint tissues and thereby makes Cn an interesting target for therapeutic intervention of OA. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

A Serological Biomarker of Versican Degradation is Associated with Mortality Following Acute Exacerbations of Idiopathic Interstitial Pneumonia.

PubMed

Sand, Jannie M B; Tanino, Yoshinori; Karsdal, Morten A; Nikaido, Takefumi; Misa, Kenichi; Sato, Yuki; Togawa, Ryuichi; Wang, Xintao; Leeming, Diana J; Munakata, Mitsuru

2018-05-04

Idiopathic interstitial pneumonia (IIP) is characterized by an increased rate of extracellular matrix (ECM) remodeling resulting in fibrosis. Acute exacerbations of IIP represent periods of increased disease activity, thus we hypothesized that ECM remodeling was altered during acute exacerbations and investigated this by serological neo-epitope biomarkers. Patients who were sequentially admitted to the hospital with acute exacerbations of IIP were retrospectively analyzed for ECM remodeling at time of exacerbation (AE-IIP) and at clinical stability (S-IIP). Biomarkers released by matrix metalloproteinase-mediated degradation of collagen type I (C1M), III (C3M), IV (C4M), and VI (C6M), elastin (ELM7), versican (VCANM), biglycan (BGM), and C-reactive protein (CRPM) were assessed in serum by competitive ELISAs utilizing neo-epitope specific monoclonal antibodies. Sixty-eight patients at AE-IIP and 29 at S-IIP were included in this retrospective analysis. Of these, 28 and 11 patients, respectively, had idiopathic pulmonary fibrosis. At AE-IIP, serum levels of C4M (p = 0.002) and C6M (p = 0.024) were increased as compared with S-IIP, while ELM7 (p = 0.024) and VCANM (p < 0.0001) were decreased. Lower VCANM levels at AE-IIP were associated with increased risk of mortality (HR 0.64 [95% CI 0.43-0.94], p = 0.022). The ECM remodeling profile was significantly altered during acute exacerbations of IIP, and a biomarker of versican degradation was related to mortality outcome. These results indicate that biomarkers of ECM remodeling may be useful in the non-invasive evaluation of acute exacerbations of IIP. Especially versican degradation, as measured serologically by VCANM, may have prognostic potential and help guide treatment for acute exacerbations.

Increased Platelet Concentration does not Improve Functional Graft Healing in Bio-Enhanced ACL Reconstruction

PubMed Central

Fleming, Braden C.; Proffen, Benedikt L.; Vavken, Patrick; Shalvoy, Matthew R.; Machan, Jason T.; Murray, Martha M.

2014-01-01

Purpose The use of an extra-cellular matrix scaffold (ECM) combined with platelets to enhance healing of an ACL graft (“bio-enhanced ACL reconstruction”) has shown promise in animal models. However, the effects of platelet concentration on graft healing remains unknown. The objectives of this study were to determine if increasing the platelet concentration in the ECM scaffold would; 1) improve the graft biomechanical properties, and 2) decrease cartilage damage after surgery. Methods Fifty-five adolescent minipigs were randomized to 5 treatment groups; untreated ACL transection (n=10), conventional ACL reconstruction (n=15), and bio-enhanced ACL reconstruction using 1X (n=10), 3X (n=10) or 5X (n=10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. Results The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1X preparation was significantly greater than traditional reconstruction while the 3X and 5X preparations were not. The failure loads of all the ACL reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the ligament maturity index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Conclusions Only the 1X platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1X to 5X in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery. PMID:24633008

Increased platelet concentration does not improve functional graft healing in bio-enhanced ACL reconstruction.

PubMed

Fleming, Braden C; Proffen, Benedikt L; Vavken, Patrick; Shalvoy, Matthew R; Machan, Jason T; Murray, Martha M

2015-04-01

The use of an extracellular matrix scaffold (ECM) combined with platelets to enhance healing of an anterior cruciate ligament (ACL) graft ("bio-enhanced ACL reconstruction") has shown promise in animal models. However, the effects of platelet concentration on graft healing remain unknown. The objectives of this study were to determine whether increasing the platelet concentration in the ECM scaffold would (1) improve the graft biomechanical properties and (2) decrease cartilage damage after surgery. Fifty-five adolescent minipigs were randomized to five treatment groups: untreated ACL transection (n = 10), conventional ACL reconstruction (n = 15) and bio-enhanced ACL reconstruction using 1× (n = 10), 3× (n = 10) or 5× (n = 10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1× preparation was significantly greater than traditional reconstruction, while the 3× and 5× preparations were not. The failure loads of all the ACL-reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the Ligament Maturity Index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Only the 1× platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1× to 5× in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery.

A non-equilibrium thermodynamic model for tumor extracellular matrix with enzymatic degradation

NASA Astrophysics Data System (ADS)

Xue, Shi-Lei; Li, Bo; Feng, Xi-Qiao; Gao, Huajian

2017-07-01

The extracellular matrix (ECM) of a solid tumor not only affords scaffolding to support tumor architecture and integrity but also plays an essential role in tumor growth, invasion, metastasis, and therapeutics. In this paper, a non-equilibrium thermodynamic theory is established to study the chemo-mechanical behaviors of tumor ECM, which is modeled as a poroelastic polyelectrolyte consisting of a collagen network and proteoglycans. By using the principle of maximum energy dissipation rate, we deduce a set of governing equations for drug transport and mechanosensitive enzymatic degradation in ECM. The results reveal that osmosis is primarily responsible for the compression resistance of ECM. It is suggested that a well-designed ECM degradation can effectively modify the tumor microenvironment for improved efficiency of cancer therapy. The theoretical predictions show a good agreement with relevant experimental observations. This study aimed to deepen our understanding of tumor ECM may be conducive to novel anticancer strategies.

Biological Regulation of Bone Quality

PubMed Central

Alliston, Tamara

2014-01-01

The ability of bone to resist fracture is determined by the combination of bone mass and bone quality. Like bone mass, bone quality is carefully regulated. Of the many aspects of bone quality, this review focuses on biological mechanisms that control the material quality of the bone extracellular matrix (ECM). Bone ECM quality depends upon ECM composition and organization. Proteins and signaling pathways that affect the mineral or organic constituents of bone ECM impact bone ECM material properties, such as elastic modulus and hardness. These properties are also sensitive to pathways that regulate bone remodeling by osteoblasts, osteoclasts, and osteocytes. Several extracellular proteins, signaling pathways, intracellular effectors, and transcription regulatory networks have been implicated in the control of bone ECM quality. A molecular understanding of these mechanisms will elucidate the biological control of bone quality and suggest new targets for the development of therapies to prevent bone fragility. PMID:24894149

Extracellular matrix structure.

PubMed

Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

2016-02-01

Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.

Mechanistic understanding of nanoparticles' interactions with extracellular matrix: the cell and immune system.

PubMed

Engin, Ayse Basak; Nikitovic, Dragana; Neagu, Monica; Henrich-Noack, Petra; Docea, Anca Oana; Shtilman, Mikhail I; Golokhvast, Kirill; Tsatsakis, Aristidis M

2017-06-24

Extracellular matrix (ECM) is an extraordinarily complex and unique meshwork composed of structural proteins and glycosaminoglycans. The ECM provides essential physical scaffolding for the cellular constituents, as well as contributes to crucial biochemical signaling. Importantly, ECM is an indispensable part of all biological barriers and substantially modulates the interchange of the nanotechnology products through these barriers. The interactions of the ECM with nanoparticles (NPs) depend on the morphological characteristics of intercellular matrix and on the physical characteristics of the NPs and may be either deleterious or beneficial. Importantly, an altered expression of ECM molecules ultimately affects all biological processes including inflammation. This review critically discusses the specific behavior of NPs that are within the ECM domain, and passing through the biological barriers. Furthermore, regenerative and toxicological aspects of nanomaterials are debated in terms of the immune cells-NPs interactions.

Insight On Colorectal Carcinoma Infiltration by Studying Perilesional Extracellular Matrix

PubMed Central

Nebuloni, Manuela; Albarello, Luca; Andolfo, Annapaola; Magagnotti, Cinzia; Genovese, Luca; Locatelli, Irene; Tonon, Giovanni; Longhi, Erika; Zerbi, Pietro; Allevi, Raffaele; Podestà, Alessandro; Puricelli, Luca; Milani, Paolo; Soldarini, Armando; Salonia, Andrea; Alfano, Massimo

2016-01-01

The extracellular matrix (ECM) from perilesional and colorectal carcinoma (CRC), but not healthy colon, sustains proliferation and invasion of tumor cells. We investigated the biochemical and physical diversity of ECM in pair-wised comparisons of healthy, perilesional and CRC specimens. Progressive linearization and degree of organization of fibrils was observed from healthy to perilesional and CRC ECM, and was associated with a steady increase of stiffness and collagen crosslinking. In the perilesional ECM these modifications coincided with increased vascularization, whereas in the neoplastic ECM they were associated with altered modulation of matrisome proteins, increased content of hydroxylated lysine and lysyl oxidase. This study identifies the increased stiffness and crosslinking of the perilesional ECM predisposing an environment suitable for CRC invasion as a phenomenon associated with vascularization. The increased stiffness of colon areas may represent a new predictive marker of desmoplastic region predisposing to invasion, thus offering new potential application for monitoring adenoma with invasive potential. PMID:26940881

Mesenchymal stem cell-derived extracellular matrix enhances chondrogenic phenotype of and cartilage formation by encapsulated chondrocytes in vitro and in vivo.

PubMed

Yang, Yuanheng; Lin, Hang; Shen, He; Wang, Bing; Lei, Guanghua; Tuan, Rocky S

2018-03-15

Mesenchymal stem cell derived extracellular matrix (MSC-ECM) is a natural biomaterial with robust bioactivity and good biocompatibility, and has been studied as a scaffold for tissue engineering. In this investigation, we tested the applicability of using decellularized human bone marrow derived MSC-ECM (hBMSC-ECM) as a culture substrate for chondrocyte expansion in vitro, as well as a scaffold for chondrocyte-based cartilage repair. hBMSC-ECM deposited by hBMSCs cultured on tissue culture plastic (TCP) was harvested, and then subjected to a decellularization process to remove hBMSCs. Compared with chondrocytes grown on TCP, chondrocytes seeded onto hBMSC-ECM exhibited significantly increased proliferation rate, and maintained better chondrocytic phenotype than TCP group. After being expanded to the same cell number and placed in high-density micromass cultures, chondrocytes from the ECM group showed better chondrogenic differentiation profile than those from the TCP group. To test cartilage formation ability, composites of hBMSC-ECM impregnated with chondrocytes were subjected to brief trypsin treatment to allow cell-mediated contraction, and folded to form 3-dimensional chondrocyte-impregnated hBMSC-ECM (Cell/ECM constructs). Upon culture in vitro in chondrogenic medium for 21 days, robust cartilage formation was observed in the Cell/ECM constructs. Similarly prepared Cell/ECM constructs were tested in vivo by subcutaneous implantation into SCID mice. Prominent cartilage formation was observed in the implanted Cell/ECM constructs 14 days post-implantation, with higher sGAG deposition compared to controls consisting of chondrocyte cell sheets. Taken together, these findings demonstrate that hBMSC-ECM is a superior culture substrate for chondrocyte expansion and a bioactive matrix potentially applicable for cartilage regeneration in vivo. Current cell-based treatments for focal cartilage defects face challenges, including chondrocyte dedifferentiation, need for xenogenic scaffolds, and suboptimal cartilage formation. We present here a novel technique that utilizes adult stem cell-derived extracellular matrix, as a culture substrate and/or encapsulation scaffold for human adult chondrocytes, for the repair of cartilage defects. Chondrocytes cultured in stem cell-derived matrix showed higher proliferation, better chondrocytic phenotype, and improved redifferentiation ability upon in vitro culture expansion. Most importantly, 3-dimensional constructs formed from chondrocytes folded within stem cell matrix manifested excellent cartilage formation both in vitro and in vivo. These findings demonstrate the suitability of stem cell-derived extracellular matrix as a culture substrate for chondrocyte expansion as well as a candidate bioactive matrix for cartilage regeneration. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats

PubMed Central

Goyal, Ritu; Guvendiren, Murat; Freeman, Onyi; Mao, Yong; Kohn, Joachim

2017-01-01

The design of composite tissue scaffolds containing an extracellular matrix (ECM) and synthetic polymer fibers is a new approach to create bioactive scaffolds that can enhance cell function. Currently, studies investigating the effects of ECM-deposition and decellularization on polymer degradation are still lacking, as are data on optimizing the stability of the ECM-containing composite scaffolds during prolonged cell culture. In this study, we develop fibrous scaffolds using three polymer compositions, representing slow (E0000), medium (E0500), and fast (E1000) degrading materials, to investigate the stability, degradation, and mechanics of the scaffolds during ECM deposition and decellularization, and during the complete cellularization-decell-recell cycle. We report data on percent molecular weight (% Mw) retention of polymeric fiber mats, changes in scaffold stiffness, ECM deposition, and the presence of fibronectin after decellularization. We concluded that the fast degrading E1000 (Mw retention ≤ 50% after 28 days) was not sufficiently stable to allow scaffold handling after 28 days in culture, while the slow degradation of E0000 (Mw retention ≥ 80% in 28 days) did not allow deposited ECM to replace the polymer support. The scaffolds made from medium degrading E0500 (Mw retention about 60% at 28 days) allowed the gradual replacement of the polymer network with cell-derived ECM while maintaining the polymer network support. Thus, polymers with an intermediate rate of degradation, maintaining good scaffold handling properties after 28 days in culture, seem best suited for creating ECM-polymer composite scaffolds. PMID:28085047

Resistance to infection of five different materials in a rat body wall model.

PubMed

Medberry, Christopher J; Tottey, Stephen; Jiang, Hongbin; Johnson, Scott A; Badylak, Stephen F

2012-03-01

Infection occurs after approximately 1% of hernia repair procedures. The resistance to infection of the repair materials is therefore an important consideration. We evaluated the infection resistance of five different materials in a rat model of body wall repair, two of which, urinary bladder matrix (UBM-ECM) and Revive, were not previously evaluated in a controlled model of infection. An inoculum of 1 × 10(8) colony forming units of Staphylococcus aureus was delivered to the wound site following implantation of an autograft, UBM-ECM, Proceed, Prolene, or Revive. Infection was monitored by white blood cell counts, body temperature, bacterial culture, and histomorphologic analysis of the implant site. Infection was shown in all groups through increased white blood cell count and body temperature. Animals with UBM-ECM returned to pre-surgery body temperature before all other groups. Substantial bacterial clearance was found in the autograft, UBM-ECM, and Prolene. Histomorphologic analysis showed evidence for persistent bacterial infection in Prolene, Proceed, and Revive 28 d after implantation, whereas the autograft and UBM-ECM appeared free of infection. The autograft showed a pyogranulomatous inflammatory reaction at 28 d while UBM-ECM was similar to uninfected controls. Superior infection resistance was shown by UBM-ECM compared with the other materials, which were substantially equivalent. Histomorphologic analysis clearly showed an increased ability to resist persistent bacterial infection for UBM-ECM. Our results suggest UBM-ECM may be useful as a repair material in areas of high risk for infection. Copyright © 2012 Elsevier Inc. All rights reserved.

Word-wide meta-analysis of Quercus forests ectomycorrhizal fungal diversity reveals southwestern Mexico as a hotspot.

PubMed

García-Guzmán, Olimpia Mariana; Garibay-Orijel, Roberto; Hernández, Edith; Arellano-Torres, Elsa; Oyama, Ken

2017-11-01

Quercus is the most diverse genus of ectomycorrhizal (ECM) host plants; it is distributed in the Northern and Southern Hemispheres, from temperate to tropical regions. However, their ECM communities have been scarcely studied in comparison to those of conifers. The objectives of this study were to determine the richness of ECM fungi associated with oak forests in the Cuitzeo basin in southwestern Mexico; and to determine the level of richness, potential endemism and species similarity among ECM fungal communities associated with natural oak forests worldwide through a meta-analysis. The ITS DNA sequences of ECM root tips from 14 studies were included in the meta-analysis. In total, 1065 species of ECM fungi have been documented worldwide; however, 812 species have been only found at one site. Oak forests in Europe contain 416 species, Mexico 307, USA 285, and China 151. Species with wider distributions are Sebacinaceae sp. SH197130, Amanita subjunquillea, Cenococcum geophilum, Cortinarius decipiens, Russula hortensis, R. risigallina, R. subrubescens, Sebacinaceae sp. SH214607, Tomentella ferruginea, and T. lapida. The meta-analysis revealed (1) that Mexico is not only a hotspot for oak species but also for their ECM mycobionts. (2) There is a particularly high diversity of ECM Pezizales in oak seasonal forests from western USA to southwestern Mexico. (3) The oak forests in southwestern Mexico have the largest number of potential endemic species. (4) Globally, there is a high turnover of ECM fungal species associated with oaks, which indicates high levels of alpha and beta diversity in these communities.

Effects of Matrix Alignment and Mechanical Constraints on Cellular Behavior in 3D Engineered Microtissues

NASA Astrophysics Data System (ADS)

Bose, Prasenjit; Eyckmans, Jeroen; Chen, Christopher; Reich, Daniel

The adhesion of cells to the extracellular matrix (ECM) plays a crucial role in a variety of cellular functions. The main building blocks of the ECM are 3D networks of fibrous proteins whose structure and alignments varies with tissue type. However, the impact of ECM alignment on cellular behaviors such as cell adhesion, spreading, extension and mechanics remains poorly understood. We present results on the development of a microtissue-based system that enables control of the structure, orientation, and degree of fibrillar alignment in 3D fibroblast-populated collagen gels. The tissues self-assemble from cell-laden collagen gels placed in micro-fabricated wells containing sets of elastic pillars. The contractile action of the cells leads to controlled alignment of the fibrous collagen, depending on the number and location of the pillars in each well. The pillars are elastic, and are utilized to measure the contractile forces of the microtissues, and by incorporating magnetic material in selected pillars, time-varying forces can be applied to the tissues for dynamic stimulation and measurement of mechanical properties. Results on the effects of varying pillar shape, spacing, location, and stiffness on microtissue organization and contractility will be presented. This work is supported by NSF CMMI-1463011.

Quantitative proteomics identify an association between extracellular matrix degradation and immunopathology of genotype VII Newcastle disease virus in the spleen in chickens.

PubMed

Hu, Zenglei; Gu, Han; Hu, Jiao; Hu, Shunlin; Wang, Xiaoquan; Liu, Xiaowen; Jiao, Xinan; Liu, Xiufan

2018-06-15

Pathogenesis of genotype VII Newcastle disease virus (NDV) is characterized with remarkable immunopathology in the spleen in chickens. However, the mechanism for this unique pathological phenotype is not fully understood. Previous transcriptomics data showed that genotype VII NDV JS5/05 caused a greater downregulation of extracellular matrix (ECM) genes than genotype IV virus Herts/33 in the spleen. In this study, the role of ECM in pathology of genotype VII NDV was investigated using quantitative proteomics. Pathology studies showed that JS5/05 caused severe immunopathology characterized with remarkable necrosis in the spleen, whereas Herts/33 only induced mild pathological changes. The ECM was firstly enriched from the spleens and ECM proteins of different categories were identified by LC-MS/MS. Quantitative proteomic analysis showed that JS5/05 caused a significant disruption of ECM integrity and molecular composition compared to Herts/33. Particularly, JS5/05 induced a more remarkable collagen breakdown in the spleen compared to Herts/33. Moreover, matrix metalloproteinase (MMP)-13 and -14 were significantly upregulated by JS5/05 infection. KEGG pathway analysis suggested that differential regulation of ECM proteins by JS5/05 and Herts/33 may impact pathology through different pathways. Therefore, our results suggested that MMP upregulation and consequent ECM degradation contribute to immunopathology of genotype VII NDV in the spleen. Pathogenesis of genotype VII NDV is characterized with severe immunopathology in the spleen in chickens. Elucidating the mechanism of this pathology phenotype is critical to understand pathogenesis of genotype VII NDV. Here, we present the proteomic data of an important non-cellular compartment, the extracellular matrix (ECM), in the spleen from chickens infected with genotype VII and IV NDVs. Our results suggest that significant upregulation of matrix metalloproteinases by genotype VII NDV and consequent disruption of ECM integrity and composition may be associated with immunopathology in the spleen. Moreover, ECM degradation, represented by collagen breakdown, is an important pathology event in the process of genotype VII NDV infection. Our study for the first time presents evidence of ECM regulation by NDV and adds ECM remodeling as a new manifestation for NDV pathology. Our findings also deepen the understanding of NDV pathogenesis. Copyright © 2018. Published by Elsevier B.V.

Extracellular matrix motion and early morphogenesis

PubMed Central

Loganathan, Rajprasad; Rongish, Brenda J.; Smith, Christopher M.; Filla, Michael B.; Czirok, Andras; Bénazéraf, Bertrand

2016-01-01

For over a century, embryologists who studied cellular motion in early amniotes generally assumed that morphogenetic movement reflected migration relative to a static extracellular matrix (ECM) scaffold. However, as we discuss in this Review, recent investigations reveal that the ECM is also moving during morphogenesis. Time-lapse studies show how convective tissue displacement patterns, as visualized by ECM markers, contribute to morphogenesis and organogenesis. Computational image analysis distinguishes between cell-autonomous (active) displacements and convection caused by large-scale (composite) tissue movements. Modern quantification of large-scale ‘total’ cellular motion and the accompanying ECM motion in the embryo demonstrates that a dynamic ECM is required for generation of the emergent motion patterns that drive amniote morphogenesis. PMID:27302396

Extracellular Matrix as a Regulator of Epidermal Stem Cell Fate.

PubMed

Chermnykh, Elina; Kalabusheva, Ekaterina; Vorotelyak, Ekaterina

2018-03-27

Epidermal stem cells reside within the specific anatomic location, called niche, which is a microenvironment that interacts with stem cells to regulate their fate. Regulation of many important processes, including maintenance of stem cell quiescence, self-renewal, and homeostasis, as well as the regulation of division and differentiation, are common functions of the stem cell niche. As it was shown in multiple studies, extracellular matrix (ECM) contributes a lot to stem cell niches in various tissues, including that of skin. In epidermis, ECM is represented, primarily, by a highly specialized ECM structure, basement membrane (BM), which separates the epidermal and dermal compartments. Epidermal stem cells contact with BM, but when they lose the contact and migrate to the overlying layers, they undergo terminal differentiation. When considering all of these factors, ECM is of fundamental importance in regulating epidermal stem cells maintenance, proper mobilization, and differentiation. Here, we summarize the remarkable progress that has recently been made in the research of ECM role in regulating epidermal stem cell fate, paying special attention to the hair follicle stem cell niche. We show that the destruction of ECM components impairs epidermal stem cell morphogenesis and homeostasis. A deep understanding of ECM molecular structure as well as the development of in vitro system for stem cell maintaining by ECM proteins may bring us to developing new approaches for regenerative medicine.

Development of extracellular matrix in chick paravertebral sympathetic ganglia.

PubMed

Luckenbill-Edds, L

1986-08-01

Alcian blue staining coupled with enzyme digestion or critical electrolyte staining revealed differences in the development of extracellular matrix (ECM) within sympathetic ganglia compared with the surrounding capsule. On day 5 of chick development (Hamburger-Hamilton stage 26) only hyaluronic acid (HA) could be detected in the ECM surrounding condensing primary ganglia. By day 7 (st 30) the ganglionic capsule contained HA, as well as sulfated glycosaminoglycans (GAGs), and this pattern continued into the adult stage. During the later stages of embryonic life (st 41-45) satellite cells appear, showing fine structural characteristics that point to their role in the secretion of intraganglionic ECM. Only during these stages could ECM be detected histochemically within ganglia, the same stages (days 15-19) when routine electron microscopic methods reveal collagen fibrils embedded in a granular ground substance. Thus, the intraganglionic environment appears as a separate compartment free of detectable amounts of GAG until late embryonic stages when ECM is secreted around satellite cells. This developmental pattern could represent a role of ECM in the histological stabilization of ganglia during the late stages of differentiation, since the appearance of intraganglionic ECM is correlated with the appearance of small dense-cored vesicles characteristic of adult neurons. The developmental pattern of ECM in differentiating sympathetic ganglia is compared with that of other tissues that undergo condensation and morphogenesis.

Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)

NASA Astrophysics Data System (ADS)

Klocke, F.; Herrig, T.; Zeis, M.; Klink, A.

2017-10-01

Combining the working principle of electrochemical machining (ECM) with a universal rotating tool, like a wire, could manage lots of challenges of the classical ECM sinking process. Such a wire-ECM process could be able to machine flexible and efficient 2.5-dimensional geometries like fir tree slots in turbine discs. Nowadays, established manufacturing technologies for slotting turbine discs are broaching and wire electrical discharge machining (wire EDM). Nevertheless, high requirements on surface integrity of turbine parts need cost intensive process development and - in case of wire-EDM - trim cuts to reduce the heat affected rim zone. Due to the process specific advantages, ECM is an attractive alternative manufacturing technology and is getting more and more relevant for sinking applications within the last few years. But ECM is also opposed with high costs for process development and complex electrolyte flow devices. In the past, few studies dealt with the development of a wire ECM process to meet these challenges. However, previous concepts of wire ECM were only suitable for micro machining applications. Due to insufficient flushing concepts the application of the process for machining macro geometries failed. Therefore, this paper presents the modeling and simulation of a new flushing approach for process assessment. The suitability of a rotating structured wire electrode in combination with an axial flushing for electrodes with high aspect ratios is investigated and discussed.

Advanced Communications Technology Satellite high burst rate link evaluation terminal experiment control and monitor software maintenance manual, version 1.0

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

1992-01-01

The Experiment Control and Monitor (EC&M) software was developed at NASA Lewis Research Center to support the Advanced Communications Technology Satellite (ACTS) High Burst Rate Link Evaluation Terminal (HBR-LET). The HBR-LET is an experimenter's terminal to communicate with the ACTS for various investigations by government agencies, universities, and industry. The EC&M software is one segment of the Control and Performance Monitoring (C&PM) software system of the HBR-LET. The EC&M software allows users to initialize, control, and monitor the instrumentation within the HBR-LET using a predefined sequence of commands. Besides instrument control, the C&PM software system is also responsible for computer communication between the HBR-LET and the ACTS NASA Ground Station and for uplink power control of the HBR-LET to demonstrate power augmentation during rain fade events. The EC&M Software User's Guide, Version 1.0 (NASA-CR-189160) outlines the commands required to install and operate the EC&M software. Input and output file descriptions, operator commands, and error recovery procedures are discussed in the document. The EC&M Software Maintenance Manual, Version 1.0 (NASA-CR-189161) is a programmer's guide that describes current implementation of the EC&M software from a technical perspective. An overview of the EC&M software, computer algorithms, format representation, and computer hardware configuration are included in the manual.

Biofilm-specific extracellular matrix proteins of nontypeable Haemophilus influenzae.

PubMed

Wu, Siva; Baum, Marc M; Kerwin, James; Guerrero, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

2014-12-01

Nontypeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen, can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24- and 96-h NTHi biofilms contained polysaccharides and proteinaceous components as detected by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24-h biofilms, two were found only in 96-h biofilms, and fifteen were present in the ECM of both 24- and 96-h NTHi biofilms. All proteins identified were either associated with bacterial membranes or cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Cell motility and ECM proteolysis regulate tumor growth and tumor relapse by altering the fraction of cancer stem cells and their spatial scattering

NASA Astrophysics Data System (ADS)

Kumar, Sandeep; Kulkarni, Rahul; Sen, Shamik

2016-06-01

Tumors consist of multiple cell sub-populations including cancer stem cells (CSCs), transiently amplifying cells and terminally differentiated cells (TDCs), with the CSC fraction dictating the aggressiveness of the tumor and drug sensitivity. In epithelial cancers, tumor growth is influenced greatly by properties of the extracellular matrix (ECM), with cancer progression associated with an increase in ECM density. However, the extent to which increased ECM confinement induced by an increase in ECM density influences tumor growth and post treatment relapse dynamics remains incompletely understood. In this study, we use a cellular automata-based discrete modeling approach to study the collective influence of ECM density, cell motility and ECM proteolysis on tumor growth, tumor heterogeneity, and tumor relapse after drug treatment. We show that while increased confinement suppresses tumor growth and the spatial scattering of CSCs, this effect can be reversed when cells become more motile and proteolytically active. Our results further suggest that, in addition to the absolute number of CSCs, their spatial positioning also plays an important role in driving tumor growth. In a nutshell, our study suggests that, in confined environments, cell motility and ECM proteolysis are two key factors that regulate tumor growth and tumor relapse dynamics by altering the number and spatial distribution of CSCs.

Cellular Mechanics of Primary Human Cervical Fibroblasts: Influence of Progesterone and a Pro-inflammatory Cytokine.

PubMed

Shukla, Vasudha; Barnhouse, Victoria; Ackerman, William E; Summerfield, Taryn L; Powell, Heather M; Leight, Jennifer L; Kniss, Douglas A; Ghadiali, Samir N

2018-01-01

The leading cause of neonatal mortality, pre-term birth, is often caused by pre-mature ripening/opening of the uterine cervix. Although cervical fibroblasts play an important role in modulating the cervix's extracellular matrix (ECM) and mechanical properties, it is not known how hormones, i.e., progesterone, and pro-inflammatory insults alter fibroblast mechanics, fibroblast-ECM interactions and the resulting changes in tissue mechanics. Here we investigate how progesterone and a pro-inflammatory cytokine, IL-1β, alter the biomechanical properties of human cervical fibroblasts and the fibroblast-ECM interactions that govern tissue-scale mechanics. Primary human fibroblasts were isolated from non-pregnant cervix and treated with estrogen/progesterone, IL-1β or both. The resulting changes in ECM gene expression, matrix remodeling, traction force generation, cell-ECM adhesion and tissue contractility were monitored. Results indicate that IL-1β induces a significant reduction in traction force and ECM adhesion independent of pre-treatment with progesterone. These cell level effects altered tissue-scale mechanics where IL-1β inhibited the contraction of a collagen gel over 6 days. Interestingly, progesterone treatment alone did not modulate traction forces or gel contraction but did result in a dramatic increase in cell-ECM adhesion. Therefore, the protective effect of progesterone may be due to altered adhesion dynamics as opposed to altered ECM remodeling.

Adipose extracellular matrix remodelling in obesity and insulin resistance☆

PubMed Central

Lin, De; Chun, Tae-Hwa; Kang, Li

2016-01-01

The extracellular matrix (ECM) of adipose tissues undergoes constant remodelling to allow adipocytes and their precursor cells to change cell shape and function in adaptation to nutritional cues. Abnormal accumulation of ECM components and their modifiers in adipose tissues has been recently demonstrated to cause obesity-associated insulin resistance, a hallmark of type 2 diabetes. Integrins and other ECM receptors (e.g. CD44) that are expressed in adipose tissues have been shown to regulate insulin sensitivity. It is well understood that a hypoxic response is observed in adipose tissue expansion during obesity progression and that hypoxic response accelerates fibrosis and inflammation in white adipose tissues. The expansion of adipose tissues should require angiogenesis; however, the excess deposition of ECM limits the angiogenic response of white adipose tissues in obesity. While recent studies have focused on the metabolic consequences and the mechanisms of adipose tissue expansion and remodelling, little attention has been paid to the role played by the interaction between peri-adipocyte ECM and their cognate cell surface receptors. This review will address what is currently known about the roles played by adipose ECM, their modifiers, and ECM receptors in obesity and insulin resistance. Understanding how excess ECM deposition in the adipose tissue deteriorates insulin sensitivity would provide us hints to develop a new therapeutic strategy for the treatment of insulin resistance and type 2 diabetes. PMID:27179976

Home Performance with ENERGY STAR: Utility Bill Analysis on Homes Participating in Austin Energy's Program

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

Belzer, D.; Mosey, G.; Dagher, L.

2008-01-01

Home Performance with ENERGY STAR (HPwES) is a jointly managed program of the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA). This program focuses on improving energy efficiency in existing homes via a whole-house approach to assessing and improving a home's energy performance, and helping to protect the environment. As a local sponsor for HPwES, Austin Energy's HPwES program offers a complete home energy assessment and a list of recommendations for efficiency improvements, along with cost estimates. The owner can choose to implement only one or the complete set of energy conservation measures. Austin Energy facilitatesmore » the process by providing economic incentives to the homeowner through its HPwES Loan program and its HPwES Rebate program. In 2005, the total number of participants in both programs was approximately 1,400. Both programs are only available for improvements made by a participating HPwES contractor. The individual household billing data - encompassing more than 7,000 households - provided by Austin Energy provides a rich data set to estimate the impacts of its HPwES program. The length of the billing histories is sufficient to develop PRISM-type models of electricity use based on several years of monthly bills before and after the installation of the conservation measures. Individual household savings were estimated from a restricted version of a PRISM-type regression model where the reference temperature to define cooling (or heating degree days) was estimated along with other parameters. Because the statistical quality of the regression models varies across individual households, three separate samples were used to measure the aggregate results. The samples were distinguished on the basis of the statistical significance of the estimated (normalized) cooling consumption. A normalized measure of cooling consumption was based on average temperatures observed over the most recent nine-year period ending in 2006. This study provided a statistically rigorous approach to incorporating the variability of expected savings across the households in the sample together with the uncertainty inherent in the regression models used to estimate those savings. While the impact of the regression errors was found to be relatively small in these particular samples, this approach may be useful in future studies using individual household billing data. The median percentage savings for the largest sample of 6,000 households in the analysis was 32%, while the mean savings was 28%. Because the number of households in the sample is very large, the standard error associated with the mean percentage savings are very small, less than 1%. A conservative statement of the average savings is that is falls in the range of 25% to 30% with a high level of certainty. This preliminary analysis provides robust estimates of average program savings, but offers no insight into how savings may vary by type of conservation measure or whether savings vary by the amount of cooling electricity used prior to undertaking the measure. Follow-up researchers may want to analyze the impacts of specific ECMs. Households that use electricity for heating might also be separately analyzed. In potential future work several methodological improvements could also be explored. As mentioned in Section 2, there was no formal attempt to clean the data set of outliers and other abnormal patterns of billing data prior to the statistical analysis. The restriction of a constant reference temperature might also be relaxed. This approach may provide evidence as to whether any 'take-back' efforts are present, whereby thermostat settings are lowered during the summer months after the measures are undertaken (reflected in lower reference temperatures in the post-ECM period). A more extended analysis may also justify the investment in and use of the PRISM software package, which may provide more diagnostic measures with respect to the reference temperature. PRISM also appears to contain some built-in capability to detect outliers and other anomalous data points.« less

Extracellular matrix in uterine leiomyoma pathogenesis: a potential target for future therapeutics.

PubMed

Islam, Md Soriful; Ciavattini, Andrea; Petraglia, Felice; Castellucci, Mario; Ciarmela, Pasquapina

2018-01-01

Uterine leiomyoma (also known as fibroid or myoma) is the most common benign tumor of the uterus found in women of reproductive age. It is not usually fatal but can produce serious clinical symptoms, including excessive uterine bleeding, pelvic pain or pressure, infertility and pregnancy complications. Due to lack of effective medical treatments surgery has been a definitive choice for the management of this tumor. Extracellular matrix (ECM) accumulation and remodeling are thought to be crucial for fibrotic diseases such as uterine leiomyoma. Indeed, ECM plays important role in forming the bulk structure of leiomyoma, and the ECM-rich rigid structure within these tumors is thought to be a cause of abnormal bleeding and pelvic pain. Therefore, a better understanding of ECM accumulation and remodeling is critical for developing new therapeutics for uterine leiomyoma. PubMed and Google Scholar were searched for all original and review articles/book chapters related to ECM and medical treatments of uterine leiomyoma published in English until May 2017. This review discusses the involvement of ECM in leiomyoma pathogenesis as well as current and future medical treatments that target ECM directly or indirectly. Uterine leiomyoma is characterized by elevated levels of collagens, fibronectin, laminins and proteoglycans. They can induce the mechanotransduction process, such as activation of the integrin-Rho/p38 MAPK/ERK pathway, resulting in cellular responses that are involved in pathogenesis and altered bidirectional signaling between leiomyoma cells and the ECM. ECM accumulation is affected by growth factors (TGF-β, activin-A and PDGF), cytokines (TNF-α), steroid hormones (estrogen and progesterone) and microRNAs (miR-29 family, miR-200c and miR-93/106b). Among these, TGF-βs (1 and 3) and activin-A have been suggested as key players in the accumulation of excessive ECM (fibrosis) in leiomyoma. The presence of elevated levels of ECM and myofibroblasts in leiomyoma supports the fibrotic character of these tumors. Interestingly, ECM may serve as a reservoir of profibrotic growth factors and enhance their activity by increasing their stability and extending their duration of signaling. At present, several classes of compounds, including gonadotropin-releasing hormone (GnRH) agonist (leuprolide acetate), GnRH antagonist (cetrorelix acetate), selective progesterone receptor modulators (ulipristate acetate and asoprisnil), antiprogestin (mifepristone) and natural compounds like vitamin D and resveratrol have been studied as medical treatments that target ECM in uterine leiomyoma. Although several types of drugs (mostly antiproliferative agents) are available for leiomyoma treatment, none of them were introduced specifically as antifibrotic agents. In light of its critical role in the process of fibrosis in leiomyoma, we propose that ECM should be considered as a crucial target for future therapeutics. Thus, the introduction of drugs that are specifically antifibrotic could be a good solution to control abnormal leiomyoma growth and associated clinical symptoms. The antifibrotic compounds can be introduced based on their ability to regulate ECM components and their receptors, as well as growth factors, cytokines, steroid hormones and their corresponding receptors and intracellular signaling pathways, as well as microRNAs, involved in ECM production in leiomyoma. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Mid-term function and remodeling potential of tissue engineered tricuspid valve: Histology and biomechanics.

PubMed

Ropcke, Diana M; Rasmussen, Jonas; Ilkjær, Christine; Skov, Søren N; Tjørnild, Marcell J; Baandrup, Ulrik T; Christian Danielsen, Carl; Hjortdal, Vibeke E; Nielsen, Sten L

2018-04-11

Tricuspid valve reconstruction using a small intestinal submucosal porcine extracellular matrix (ECM) tube graft is hypothesized to be durable for six months and show signs of recellularization and growth potential. The purpose was to histologically and biomechanically test ECM valves before and after six months of implantation in pigs for comparison with native valves. Ten 60 kg pigs were included, which survived tricuspid valve tube graft insertion. Anterior and septal tricuspid leaflets were explanted from all animals surviving more than one month and examined histologically (n = 9). Endothelialization, collagen content, mineralization, neovascularization, burst strength and tensile strength were determined for native valves (n = 5), ECM before implantation (n = 5), and ECM after six months (n = 5). Collagen density was significantly larger in ECM at implantation (baseline) compared to native leaflet tissue (0.3 ± 0.02 mg/mm 3 vs. 0.1 ± 0.03 mg/mm 3 , p < .0001), but collagen density decreased and reached native leaflet collagen content, six months after ECM implantation (native vs. ECM valve at six months: 0.1 ± 0.03 mg/mm 3 vs. 0.2 ± 0.05 mg/mm 3 , p = .8). Histologically, ECM valves showed endothelialization, host cell infiltration and structural collagen organization together with elastin generation after six months, indicating tissue remodeling and -engineering together with gradual development of a close-to-native leaflet structure without foreign body response. ECM tricuspid tube grafts were stronger than native leaflet tissue. Histologically, the acellular ECM tube grafts showed evidence of constructive tissue remodeling with endothelialization and connective tissue organization. These findings support the concept of tissue engineering and recellularization, which are prerequisites for growth. Copyright © 2018 Elsevier Ltd. All rights reserved.

Disruption of fibronectin matrix affects type IV collagen, fibrillin and laminin deposition into extracellular matrix of human trabecular meshwork (HTM) cells.

PubMed

Filla, Mark S; Dimeo, Kaylee D; Tong, Tiegang; Peters, Donna M

2017-12-01

Fibronectin fibrils are a major component of the extracellular matrix (ECM) of the trabecular meshwork (TM). They are a key mediator of the formation of the ECM which controls aqueous humor outflow and contributes to the pathogenesis of glaucoma. The purpose of this work was to determine if a fibronectin-binding peptide called FUD, derived from the Streptococcus pyogenes Functional Upstream Domain of the F1 adhesin protein, could be used to control fibronectin fibrillogenesis and hence ECM formation under conditions where its expression was induced by treatment with the glucocorticoid dexamethasone. FUD was very effective at preventing fibronectin fibrillogenesis in the presence or absence of steroid treatment as well as the removal of existing fibronectin fibrils. Disruption of fibronectin fibrillogenesis by FUD also disrupted the incorporation of type IV collagen, laminin and fibrillin into the ECM. The effect of FUD on these other protein matrices, however, was found to be dependent upon the maturity of the ECM when FUD was added. FUD effectively disrupted the incorporation of these other proteins into matrices when added to newly confluent cells that were forming a nascent ECM. In contrast, FUD had no effect on these other protein matrices if the cell cultures already possessed a pre-formed, mature ECM. Our studies indicate that FUD can be used to control fibronectin fibrillogenesis and that these fibrils play a role in regulating the assembly of other ECM protein into matrices involving type IV collagen, laminin, and fibrillin within the TM. This suggests that under in vivo conditions, FUD would selectively disrupt fibronectin fibrils and de novo assembly of other proteins into the ECM. Finally, our studies suggest that targeting fibronectin fibril assembly may be a viable treatment for POAG as well as other glaucomas involving excessive or abnormal matrix deposition of the ECM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proteomic Analysis of Altered Extracellular Matrix Turnover in Bleomycin-induced Pulmonary Fibrosis

PubMed Central

Decaris, Martin L.; Gatmaitan, Michelle; FlorCruz, Simplicia; Luo, Flora; Li, Kelvin; Holmes, William E.; Hellerstein, Marc K.; Turner, Scott M.; Emson, Claire L.

2014-01-01

Fibrotic disease is characterized by the pathological accumulation of extracellular matrix (ECM) proteins. Surprisingly, very little is known about the synthesis and degradation rates of the many proteins and proteoglycans that constitute healthy or pathological extracellular matrix. A comprehensive understanding of altered ECM protein synthesis and degradation during the onset and progression of fibrotic disease would be immensely valuable. We have developed a dynamic proteomics platform that quantifies the fractional synthesis rates of large numbers of proteins via stable isotope labeling and LC/MS-based mass isotopomer analysis. Here, we present the first broad analysis of ECM protein kinetics during the onset of experimental pulmonary fibrosis. Mice were labeled with heavy water for up to 21 days following the induction of lung fibrosis with bleomycin. Lung tissue was subjected to sequential protein extraction to fractionate cellular, guanidine-soluble ECM proteins and residual insoluble ECM proteins. Fractional synthesis rates were calculated for 34 ECM proteins or protein subunits, including collagens, proteoglycans, and microfibrillar proteins. Overall, fractional synthesis rates of guanidine-soluble ECM proteins were faster than those of insoluble ECM proteins, suggesting that the insoluble fraction reflected older, more mature matrix components. This was confirmed through the quantitation of pyridinoline cross-links in each protein fraction. In fibrotic lung tissue, there was a significant increase in the fractional synthesis of unique sets of matrix proteins during early (pre-1 week) and late (post-1 week) fibrotic response. Furthermore, we isolated fast turnover subpopulations of several ECM proteins (e.g. type I collagen) based on guanidine solubility, allowing for accelerated detection of increased synthesis of typically slow-turnover protein populations. This establishes the presence of multiple kinetic pools of pulmonary collagen in vivo with altered turnover rates during evolving fibrosis. These data demonstrate the utility of dynamic proteomics in analyzing changes in ECM protein turnover associated with the onset and progression of fibrotic disease. PMID:24741116

Full-Thickness Skin Wound Healing Using Human Placenta-Derived Extracellular Matrix Containing Bioactive Molecules

PubMed Central

Choi, Ji Suk; Kim, Jae Dong; Yoon, Hyun Soo

2013-01-01

The human placenta, a complex organ, which facilitates exchange between the fetus and the mother, contains abundant extracellular matrix (ECM) components and well-preserved endogenous growth factors. In this study, we designed a new dermal substitute from human placentas for full-thickness wound healing. Highly porous, decellularized ECM sheets were fabricated from human placentas via homogenization, centrifugation, chemical and enzymatic treatments, molding, and freeze-drying. The physical structure and biological composition of human placenta-derived ECM sheets dramatically supported the regeneration of full-thickness wound in vivo. At the early stage, the ECM sheet efficiently absorbed wound exudates and tightly attached to the wound surface. Four weeks after implantation, the wound was completely closed, epidermic cells were well arranged and the bilayer structure of the epidermis and dermis was restored. Moreover, hair follicles and microvessels were newly formed in the ECM sheet-implanted wounds. Overall, the ECM sheet produced a dermal substitute with similar cellular organization to that of normal skin. These results suggest that human placenta-derived ECM sheets provide a microenvironment favorable to the growth and differentiation of cells, and positive modulate the healing of full-thickness wounds. PMID:22891853

Ectomycorrhizal Fungal Communities and Enzymatic Activities Vary across an Ecotone between a Forest and Field.

PubMed

Rúa, Megan A; Moore, Becky; Hergott, Nicole; Van, Lily; Jackson, Colin R; Hoeksema, Jason D

2015-08-28

Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing for <5 years. ECM community and environmental characteristics influenced enzyme activity in the field, indicating that controls on enzyme activity may be intricately linked to the ECM community, but this was not true in the forest. Members of the Russulaceae were associated with increased phenol oxidase activity and decreased peroxidase activity in the field. Members of the Atheliaceae were particularly susceptible to changes in their abiotic environment, but this did not mediate differences in enzyme activity. These results emphasize the complex nature of factors that dictate the distribution of ECM and activity of their enzymes across a habitat boundary.

Decellularized Swine Dental Pulp as a Bioscaffold for Pulp Regeneration

PubMed Central

Hu, Lei; Gao, Zhenhua; Zhu, Zhao; Zhang, Chunmei; Wang, Jinsong

2017-01-01

Endodontic regeneration shows promise in treating dental pulp diseases; however, no suitable scaffolds exist for pulp regeneration. Acellular natural extracellular matrix (ECM) is a favorable scaffold for tissue regeneration since the anatomical structure and ECM of the natural tissues or organs are well-preserved. Xenogeneic ECM is superior to autologous or allogeneic ECM in tissue engineering for its unlimited resources. This study investigated the characteristics of decellularized dental pulp ECM from swine and evaluated whether it could mediate pulp regeneration. Dental pulps were acquired from the mandible anterior teeth of swine 12 months of age and decellularized with 10% sodium dodecyl sulfate (SDS) combined with Triton X-100. Pulp regeneration was conducted by seeding human dental pulp stem cells into decellularized pulp and transplanted subcutaneously into nude mice for 8 weeks. The decellularized pulp demonstrated preserved natural shape and structure without any cellular components. Histological analysis showed excellent ECM preservation and pulp-like tissue, and newly formed mineralized tissues were regenerated after being transplanted in vivo. In conclusion, decellularized swine dental pulp maintains ECM components favoring stem cell proliferation and differentiation, thus representing a suitable scaffold for improving clinical outcomes and functions of teeth with dental pulp diseases. PMID:29387727

Decellularized heart ECM hydrogel using supercritical carbon dioxide for improved angiogenesis.

PubMed

Seo, Yoojin; Jung, Youngmee; Kim, Soo Hyun

2018-02-01

Initial angiogenesis within the first 3 days is critical for healing ischemic diseases such as myocardial infarction. Recently, decellularized extracellular matrix (dECM) has been reported to provide tissue-derived ECM components and can be used as a scaffold for cell delivery for angiogenesis in tissue engineering. Decellularization by various detergents such as sodium dodecyl sulfate (SDS) and triton X-100 can remove the cell nuclei in tissue organs. However, this leads to ECM structure denaturation, decreased presence of various ECM proteins and cytokines, and loss of mechanical properties. To overcome these limitations, in this study, we developed a supercritical carbon dioxide and ethanol co-solvent (scCO 2 -EtOH) decellularization method, which is a detergent-free system that prevents ECM structure disruption and retains various angiogenic proteins in the heart dECM, and tested on rat heart tissues. The heart tissue was placed into the scCO 2 reactor and decellularized at 37 °C and 350 bar. After scCO 2 -EtOH treatment, the effects were evaluated by DNA, collagen, and glycosaminoglycan (GAG) quantification and hematoxylin and eosin and immunofluorescence staining to determine the absence of nucleic acids and preservation of heart ECM components. Similar to the native group, the scCO 2 -EtOH group contained more ECM components such as collagen, GAGs, collagen I, laminin, and fibronectin and angiogenic factors including vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor and others in comparison to the detergent group. In addition, to estimate angiogenesis of the dECM hydrogels, the neutralized dECM solution was injected in a rat subcutaneous layer (n = 6 in each group: collagen, scCO 2 -EOH, and detergent group), after which the solution naturally formed gelation in the subcutaneous layer. After 3 days, the gels were harvested and estimated by immunofluorescence staining and the ImageJ program for angiogenesis analysis. Consequently, blood vessel formation and density of vWF and α-SMA in the scCO 2 -EtOH group were significantly greater than that in the collagen group. Here we suggest that heart-derived decellularized extracellular matrix (dECM) with scCO 2 -EtOH treatment is a highly promising angiogenic material for healing in ischemic disease. Supercritical carbon dioxide (scCO 2 ) in a supercritical phase has low viscosity and high diffusivity between gas and liquid properties and is known to be affordable, non-toxic, and eco-friendly. Therefore, scCO 2 extraction technology has been extensively used in commercial and industrial fields. Recently, decellularized extracellular matrix (dECM) was applied to tissue engineering and regenerative medicine as a scaffold, therapeutic material, and bio-ink for 3D printing. Moreover, the general decellularization method using detergents has limitations including eliminating tissue-derived ECM components and disrupting their structures after decellularization. To overcome these limitations, heart tissues were treated with scCO 2 -EtOH for decellularization, resulting in preserving of tissue due to the various ECM and angiogenic factors derived. In addition, initiation of angiogenesis was highly induced even after 3 days of injection. Copyright © 2017. Published by Elsevier Ltd.

A Gingiva-Derived Mesenchymal Stem Cell-Laden Porcine Small Intestinal Submucosa Extracellular Matrix Construct Promotes Myomucosal Regeneration of the Tongue

PubMed Central

Xu, Qilin; Shanti, Rabie M.; Zhang, Qunzhou; Cannady, Steven B.

2017-01-01

In the oral cavity, the tongue is the anatomic subsite most commonly involved by invasive squamous cell carcinoma. Current treatment protocols often require significant tissue resection to achieve adequate negative margins and optimal local tumor control. Reconstruction of the tongue while preserving and/or restoring its critical vocal, chewing, and swallowing functions remains one of the major challenges in head and neck oncologic surgery. We investigated the in vitro feasibility of fabricating a novel combinatorial construct using porcine small intestinal submucosa extracellular matrix (SIS-ECM) and human gingiva-derived mesenchymal stem cells (GMSCs) as a GMSC/SIS-ECM tissue graft for the tongue reconstruction. We developed a rat model of critical-sized myomucosal defect of the tongue that allowed the testing of therapeutic effects of an acellular SIS-ECM construct versus a GMSC/SIS-ECM construct on repair and regeneration of the tongue defect. We showed that the GMSC/SIS-ECM construct engrafted at the host recipient site, promoted soft tissue healing, and regenerated the muscular layer, compared to the SIS-ECM alone or nontreated defect controls. Furthermore, our results revealed that transplantation of the GMSC/SIS-ECM construct significantly increased the expression of several myogenic transcriptional factors and simultaneously suppressed the expression of type I collagen at the wounded area of the tongue. These compelling findings suggest that, unlike the tongue contracture and fibrosis of the nontreated defect group, transplantation of the combinatorial GMSC/SIS-ECM constructs accelerates wound healing and muscle regeneration and maintains the overall tongue shape, possibly by both enhancing the function of endogenous skeletal progenitor cells and suppressing fibrosis. Together, our findings indicate that GMSC/SIS-ECM potentially served as a myomucosal graft for tongue reconstruction postsurgery of head and neck cancer. PMID:27923325

Correlation between ECM guidance and actin polymerization on osteogenic differentiation of human adipose-derived stem cells

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

Keller, Vivian; Deiwick, Andrea; Pflaum, Michael

The correlation between extracellular matrix (ECM) components, cell shape, and stem cell guidance can shed light in understanding and mimicking the functionality of stem cell niches for various applications. This interplay on osteogenic guidance of human adipose-derived stem cells (hASCs) was focus of this study. Proliferation and osteogenic markers like alkaline phosphatase activity and calcium mineralization were slightly increased by the ECM components laminin (LA), collagen I (COL), and fibronectin (FIB); with control medium no differentiation occurred. ECM guided differentiation was rather dependent on osterix than on Runx2 pathway. FIB significantly enhanced cell elongation even in presence of actin polymerizationmore » blockers cytochalasin D (CytoD) and ROCK inhibitor Y-27632, which generally caused more rounded cells. Except for the COL surface, both inhibitors increased the extent of osterix, while the Runx2 pathway was more sensitive to the culture condition. Both inhibitors did not affect hASC proliferation. CytoD enabled osteogenic differentiation independently from the ECM, while it was rather blocked via Y-27632 treatment; on FIB the general highest extent of differentiation occurred. Taken together, the ECM effect on hASCs occurs indirectly and selectively via a dominant role of FIB: it sustains osteogenic differentiation in case of a tension-dependent control of actin polymerization. - Highlights: • Interplay of ECM and cell shape guides osteogenic differentiation of hASCs. • ECM components only present a promotive but not stimulative effect. • No direct correlation between ECM-enhanced cell elongation and differentiation. • Suppression of differentiation depends on a specific actin polymerization blocking. • Fibronectin sustains cell elongation and differentiation in case of blocking actin.« less

CARTILAGE OLIGOMERIC MATRIX PROTEIN ENHANCES MATRIX ASSEMBLY DURING CHONDROGENESIS OF HUMAN MESENCHYMAL STEM CELLS

PubMed Central

Haleem-Smith, Hana; Calderon, Raul; Song, Yingjie; Tuan, Rocky S.; Chen, Faye H.

2011-01-01

Cartilage oligomeric matrix protein/thrombospondin-5 (COMP/TSP5) is an abundant cartilage extracellular matrix (ECM) protein that interacts with major cartilage ECM components, including aggrecan and collagens. To test our hypothesis that COMP/TSP5 functions in the assembly of the ECM during cartilage morphogenesis, we have employed mesenchymal stem cell (MSC) chondrogenesis in vitro as a model to examine the effects of COMP over-expression on neo-cartilage formation. Human bone marrow-derived MSCs were transfected with either full-length COMP cDNA or control plasmid, followed by chondrogenic induction in three-dimensional pellet or alginate-hydrogel culture. MSC chondrogenesis and ECM production was estimated based on quantitation of sulfated glycosaminoglycan (sGAG) accumulation, immunohistochemistry of the presence and distribution of cartilage ECM proteins, and real-time RT-PCR analyis of mRNA expression of cartilage markers. Our results showed that COMP over-expression resulted in increased total sGAG content during the early phase of MSC chondrogenesis, and increased immuno-detectable levels of aggrecan and collagen type II in the ECM of COMP-transfected pellet and alginate cultures, indicating more abundant cartilaginous matrix. COMP transfection did not significantly increase the transcript levels of the early chondrogenic marker, Sox9, or aggrecan, suggesting that enhancement of MSC cartilage ECM was effected at post-transcriptional levels. These findings strongly suggest that COMP functions in mesenchymal chondrogenesis by enhancing cartilage ECM organization and assembly. The action of COMP is most likely mediated not via direct changes in cartilage matrix gene expression but via interactions of COMP with other cartilage ECM proteins, such as aggrecan and collagens, that result in enhanced assembly and retention. PMID:22095699

Human fibroblast matrices bio-assembled under macromolecular crowding support stable propagation of human embryonic stem cells.

PubMed

Peng, Yanxian; Bocker, Michael Thomas; Holm, Jennifer; Toh, Wei Seong; Hughes, Christopher Stephen; Kidwai, Fahad; Lajoie, Gilles Andre; Cao, Tong; Lyko, Frank; Raghunath, Michael

2012-11-01

Stable pluripotent feeder-free propagation of human embryonic stem cells (hESCs) prior to their therapeutic applications remains a major challenge. Matrigel™ (BD Singapore) is a murine sarcoma-derived extracellular matrix (ECM) widely used as a cell-free support combined with conditioned or chemically defined media; however, inherent xenogenic and immunological threats invalidate it for clinical applications. Using human fibrogenic cells to generate ECM is promising but currently suffers from inefficient and time-consuming deposition in vitro. We recently showed that macromolecular crowding (MMC) accelerated ECM deposition substantially in vitro. In the current study, we used dextran sulfate 500 kDa as a macromolecular crowder to induce WI-38 fetal human lung fibroblasts at 0.5% serum condition to deposit human ECM in three days. After decellularization, the generated ECMs allowed stable propagation of H9 hESCs over 20 passages in chemically-defined medium (mTEsR1) with an overall improved outcome compared to Matrigel in terms of population doubling while retaining teratoma formation and differentiation capacity. Of significance, only ECMs generated by MMC allowed the successful propagation of hESCs. ECMs were highly complex and in contrast to Matrigel, contained no vitronectin but did contain collagen XII, ig-h3 and novel for hESC-supporting human matrices, substantial amounts of transglutaminase 2. Genome-wide analysis of promoter DNA methylation states revealed high overall similarity between human ECM- and Matrigel-cultured hESCs; however, distinct differences were observed with 49 genes associated with a variety of cellular functions. Thus, human ECMs deposited by MMC by selected fibroblast lines are a suitable human microenvironment for stable hESC propagation and clinically translational settings. Copyright © 2012 John Wiley & Sons, Ltd.

The extracellular matrix: A dynamic niche in cancer progression

PubMed Central

Lu, Pengfei; Weaver, Valerie M.

2012-01-01

The local microenvironment, or niche, of a cancer cell plays important roles in cancer development. A major component of the niche is the extracellular matrix (ECM), a complex network of macromolecules with distinctive physical, biochemical, and biomechanical properties. Although tightly controlled during embryonic development and organ homeostasis, the ECM is commonly deregulated and becomes disorganized in diseases such as cancer. Abnormal ECM affects cancer progression by directly promoting cellular transformation and metastasis. Importantly, however, ECM anomalies also deregulate behavior of stromal cells, facilitate tumor-associated angiogenesis and inflammation, and thus lead to generation of a tumorigenic microenvironment. Understanding how ECM composition and topography are maintained and how their deregulation influences cancer progression may help develop new therapeutic interventions by targeting the tumor niche. PMID:22351925

Extracellular matrix motion and early morphogenesis.

PubMed

Loganathan, Rajprasad; Rongish, Brenda J; Smith, Christopher M; Filla, Michael B; Czirok, Andras; Bénazéraf, Bertrand; Little, Charles D

2016-06-15

For over a century, embryologists who studied cellular motion in early amniotes generally assumed that morphogenetic movement reflected migration relative to a static extracellular matrix (ECM) scaffold. However, as we discuss in this Review, recent investigations reveal that the ECM is also moving during morphogenesis. Time-lapse studies show how convective tissue displacement patterns, as visualized by ECM markers, contribute to morphogenesis and organogenesis. Computational image analysis distinguishes between cell-autonomous (active) displacements and convection caused by large-scale (composite) tissue movements. Modern quantification of large-scale 'total' cellular motion and the accompanying ECM motion in the embryo demonstrates that a dynamic ECM is required for generation of the emergent motion patterns that drive amniote morphogenesis. © 2016. Published by The Company of Biologists Ltd.

75 FR 33198 - Co-Location/Proximity Hosting Services

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

... Execution Facilities (DTEFs), and Exempt Commercial Markets (ECMs) that list significant price discovery..., DTEFs, and ECMs with SPDCs, that offer co-location and/ or proximity hosting services, to disclose.... Finally, the Proposal would require DCMs, DTEFs, and ECMs with SPDCs, that approve third-parties to...

Exploring the Use of Enterprise Content Management Systems in Unification Types of Organizations

NASA Astrophysics Data System (ADS)

Izza Arshad, Noreen; Mehat, Mazlina; Ariff, Mohamed Imran Mohamed

2014-03-01

The aim of this paper is to better understand how highly standardized and integrated businesses known as unification types of organizations use Enterprise Content Management Systems (ECMS) to support their business processes. Multiple case study approach was used to study the ways two unification organizations use their ECMS in their daily work practices. Arising from these case studies are insights into the differing ways in which ECMS is used to support businesses. Based on the comparisons of the two cases, this study proposed that unification organizations may use ECMS in four ways, for: (1) collaboration, (2) information sharing that supports a standardized process structure, (3) building custom workflows that support integrated and standardized processes, and (4) providing links and access to information systems. These findings may guide organizations that are highly standardized and integrated in fashion, to achieve their intended ECMS-use, to understand reasons for ECMS failures and underutilization and to exploit technologies investments.

New methods to study the composition and structure of the extracellular matrix in natural and bioengineered tissues

PubMed Central

Schiller, Jürgen; Huster, Daniel

2012-01-01

The extracellular matrix (ECM) comprises a gel of numerous biopolymers that occurs in a multitude of biological tissues. The ECM provides the basic support and mechanical strength of skeletal tissue and is responsible for shape retention. At the same time, the ECM is responsible for the viscoelastic properties and the elasticity of soft tissues. As expected, there are several important diseases that affect and degenerate the ECM with severe consequences for its properties. Bioengineering is a promising approach to support the regenerative capacity of the body. Unfortunately, the biomechanical properties of bioengineered ECM often only poorly meet the standards of their native counterparts. Many bioengineered tissues are characterized by an increased glycosaminoglycan (GAG) but decreased collagen content. This leads to an enhanced water content that strongly alters the viscoelastic and thus the biomechanical properties. Therefore, compositional analysis is important to estimate the tissue quality. We will show that nuclear magnetic resonance (NMR) spectroscopy and soft-ionization mass spectrometry (MS) represent useful techniques for ECM research both in natural and bioengineered tissues. Both methods are strongly complimentary: while MS techniques such as matrix-assisted laser desorption and ionization (MALDI) are excellent and very sensitive analytical tools to determine the collagen and the GAG contents of tissues, NMR spectroscopy provides insight into the molecular architecture of the ECM, its dynamics and other important parameters such as the water content of the tissue as well as the diffusion of molecules within the ECM. PMID:23507863

Is the switch to an ectomycorrhizal state an evolutionary key innovation in mushroom-forming fungi? A case study in the Tricholomatineae (Agaricales).

PubMed

Sánchez-García, Marisol; Matheny, Patrick Brandon

2017-01-01

Although fungi are one of the most diverse groups of organisms, little is known about the processes that shape their high taxonomic diversity. This study focuses on evolution of ectomycorrhizal (ECM) mushroom-forming fungi, symbiotic associates of many trees and shrubs, in the suborder Tricholomatineae of the Agaricales. We used the BiSSE model and BAMM to test the hypothesis that the ECM habit represents an evolutionary key innovation that allowed the colonization of new niches followed by an increase in diversification rate. Ancestral state reconstruction (ASR) supports the ancestor of the Tricholomatineae as non-ECM. We detected two diversification rate increases in the genus Tricholoma and the Rhodopolioid clade of the genus Entoloma. However, no increases in diversification were detected in the four other ECM clades of Tricholomatineae. We suggest that diversification of Tricholoma was not only due to the evolution of the ECM lifestyle, but also to the expansion and dominance of its main hosts and ability to associate with a variety of hosts. Diversification in the Rhodopolioid clade could be due to the unique combination of spore morphology and ECM habit. The spore morphology may represent an exaptation that aided spore dispersal and colonization. This is the first study to investigate rate shifts across a phylogeny that contains both non-ECM and ECM lineages. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Extracellular Matrix and the Mechanics of Large Artery Development

PubMed Central

Cheng, Jeffrey K.; Wagenseil, Jessica E.

2012-01-01

The large, elastic arteries, as their name suggests, provide elastic distention and recoil during the cardiac cycle in vertebrate animals. The arteries are distended from the pressure of ejecting blood during active contraction of the left ventricle (LV) during systole, and recoil to their original dimensions during relaxation of the LV during diastole. The cyclic distension occurs with minimal energy loss, due to the elastic properties of one of the major structural extracellular matrix (ECM) components, elastin. The maximum distension is limited to prevent damage to the artery by another major ECM component, collagen. The mix of ECM components in the wall largely determines the passive mechanical behavior of the arteries and the subsequent load on the heart during systole. While much research has focused on initial artery formation, there has been less attention on the continuing development of the artery to produce the mature composite wall complete with endothelial cells (ECs), smooth muscle cells (SMCs), and the necessary mix of ECM components for proper cardiovascular function. This review focuses on the physiology of large artery development, including SMC differentiation and ECM production. The effects of hemodynamic forces and ECM deposition on the evolving arterial structure and function are discussed. Human diseases and mouse models with genetic mutations in ECM proteins that affect large artery development are summarized. A review of constitutive models and growth and remodeling theories is presented, along with future directions to improve understanding of ECM and the mechanics of large artery development. PMID:22584609

A 3D tension bioreactor platform to study the interplay between ECM stiffness and tumor phenotype.

PubMed

Cassereau, Luke; Miroshnikova, Yekaterina A; Ou, Guanqing; Lakins, Johnathon; Weaver, Valerie M

2015-01-10

Extracellular matrix (ECM) structure, composition, and stiffness have profound effects on tissue development and pathologies such as cardiovascular disease and cancer. Accordingly, a variety of synthetic hydrogel systems have been designed to study the impact of ECM composition, density, mechanics, and topography on cell and tissue phenotype. However, these synthetic systems fail to accurately recapitulate the biological properties and structure of the native tissue ECM. Natural three dimensional (3D) ECM hydrogels, such as collagen or hyaluronic acid, feature many of the chemical and physical properties of tissue, yet, these systems have limitations including the inability to independently control biophysical properties such as stiffness and pore size. Here, we present a 3D tension bioreactor system that permits precise mechanical tuning of collagen hydrogel stiffness, while maintaining consistent composition and pore size. We achieve this by mechanically loading collagen hydrogels covalently-conjugated to a polydimethylsiloxane (PDMS) membrane to induce hydrogel stiffening. We validated the biological application of this system with oncogenically transformed mammary epithelial cell organoids embedded in a 3D collagen I hydrogel, either uniformly stiffened or calibrated to create a gradient of ECM stiffening, to visually demonstrate the impact of ECM stiffening on transformation and tumor cell invasion. As such, this bioreactor presents the first tunable 3D natural hydrogel system that is capable of independently assessing the role of ECM stiffness on tissue phenotype. Copyright © 2014 Elsevier B.V. All rights reserved.

Minireview: Fibronectin in retinal disease.

PubMed

Miller, Charles G; Budoff, Greg; Prenner, Jonathan L; Schwarzbauer, Jean E

2017-01-01

Retinal fibrosis, characterized by dysregulation of extracellular matrix (ECM) protein deposition by retinal endothelial cells, pigment epithelial cells, and other resident cell-types, is a unifying feature of several common retinal diseases. Fibronectin is an early constituent of newly deposited ECM and serves as a template for assembly of other ECM proteins, including collagens. Under physiologic conditions, fibronectin is found in all layers of Bruch's membrane. Proliferative vitreoretinopathy (PVR), a complication of retinal surgery, is characterized by ECM accumulation. Among the earliest histologic manifestations of diabetic retinopathy (DR) is capillary basement membrane thickening, which occurs due to perturbations in ECM homeostasis. Neovascularization, the hallmark of late stage DR as well as exudative age-related macular degeneration (AMD), involves ECM assembly as a scaffold for the aberrant new vessel architecture. Rodent models of retinal injury demonstrate a key role for fibronectin in complications characteristic of PVR, including retinal detachment. In mouse models of DR, reducing fibronectin gene expression has been shown to arrest the accumulation of ECM in the capillary basement membrane. Alterations in matrix metalloproteinase activity thought to be important in the pathogenesis of AMD impact the turnover of fibronectin matrix as well as collagens. Growth factors involved in PVR, AMD, and DR, such as PDGF and TGFβ, are known to stimulate fibronectin matrix assembly. A deeper understanding of how pathologic ECM deposition contributes to disease progression may help to identify novel targets for therapeutic intervention. © 2016 by the Society for Experimental Biology and Medicine.

Effects of natural cartilaginous extracellular matrix on chondrogenic potential for cartilage cell transplantation.

PubMed

Yang, W; Lee, S; Jo, Y H; Lee, K M; Nemeno, J G; Nam, B M; Kim, B Y; Jang, I J; Kim, H N; Takebe, T; Lee, J I

2014-05-01

Autologous chondrocyte transplantation (ACT) has been established to contribute cartilage regeneration over the past years; however, many obstacles need to be overcome. Recently, newer ACT technique involves cotransplantation of chondrocytes and biomaterial. Although various proposed intelligent biomaterials exist, many of them remain insufficient and controversial. In this study, we aimed to examine the effects of natural extracellular matrix (ECM) to the proliferation rate and differentiation on the chondrocytes. We first derived a natural ECM sheet from 10-μm-thick frozen sections of porcine knee cartilages. We then cultured the chondrocytes derived from a rabbit's knee on a dish precoated with the natural ECM. Then we assessed differentiation and chondrogenic potential of the cells compared with those grown in untreated culture dishes. We characterized the gene expression of chondrogenic markers, such as collagen type II, SOX-9, and aggrecan, as well as the level of ECM protein with the use of reverse-transcription polymerase chain reaction analysis. The cells cultured with the ECM sheet showed highest chondrogenic potential and differentiation. Therefore, we can induce good chondrogenesis by with the use of a natural ECM sheet on the culture dish. The readily available and easy-to-handle thin ECM sheets create an environment that promotes efficient cartilage regeneration. Our data suggest that this natural ECM scaffold improved the chondrogenic differentiation of the cells in vitro by providing a favorable microenvironment. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot.

PubMed

Glassman, Sydney I; Levine, Carrie R; DiRocco, Angela M; Battles, John J; Bruns, Thomas D

2016-05-01

After severe wildfires, pine recovery depends on ectomycorrhizal (ECM) fungal spores surviving and serving as partners for regenerating forest trees. We took advantage of a large, severe natural forest fire that burned our long-term study plots to test the response of ECM fungi to fire. We sampled the ECM spore bank using pine seedling bioassays and high-throughput sequencing before and after the California Rim Fire. We found that ECM spore bank fungi survived the fire and dominated the colonization of in situ and bioassay seedlings, but there were specific fire adapted fungi such as Rhizopogon olivaceotinctus that increased in abundance after the fire. The frequency of ECM fungal species colonizing pre-fire bioassay seedlings, post-fire bioassay seedlings and in situ seedlings were strongly positively correlated. However, fire reduced the ECM spore bank richness by eliminating some of the rare species, and the density of the spore bank was reduced as evidenced by a larger number of soil samples that yielded uncolonized seedlings. Our results show that although there is a reduction in ECM inoculum, the ECM spore bank community largely remains intact, even after a high-intensity fire. We used advanced techniques for data quality control with Illumina and found consistent results among varying methods. Furthermore, simple greenhouse bioassays can be used to determine which fungi will colonize after fires. Similar to plant seed banks, a specific suite of ruderal, spore bank fungi take advantage of open niche space after fires.

The five-year survival of children with Down syndrome in Norway 1994-2009 differed by associated congenital heart defects and extracardiac malformations.

PubMed

Brodwall, Kristoffer; Greve, Gottfried; Leirgul, Elisabeth; Klungsøyr, Kari; Holmstrøm, Henrik; Vollset, Stein Emil; Øyen, Nina

2018-05-01

We investigated the prevalence of Down syndrome in a nationwide birth cohort, focusing on congenital heart defects (CHDs), their associations with extracardiac malformations (ECM) and survival. National registers were used to identify Norwegian births (1994-2009) and deaths (1994-2014) and updated with hospital diagnoses. We estimated birth defect frequencies in Down syndrome and the general population, the association between CHDs and ECM and hazard ratios for death from different combinations of CHDs and ECM. Down syndrome was found in 1672 of 953 450 births (17.6 per 10 000). Of the 1251 live births (13.3 per 10 000), 58% had CHD and 9% ECM. CHDs were associated with oesophageal atresia (p = 0.02) and Hirschsprung's disease (p = 0.03) but with no other malformations. The five-year survival for Down syndrome increased from 91.8% (1994-1999) to 95.8% (2000-2009) (p = 0.006), and overall survival was 92.0% with CHD and 97.4% without. Compared with Down syndrome children without CHD or ECM, the five-year mortality was similar for those with nonsevere CHDs, without or with ECM, but 4-7 times higher in those with severe CHDs without ECM and 13-28 times higher in those with severe CHDs and ECM. Down syndrome childhood survival improved, but mortality remained high with severe CHDs and extracardiac defects. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Extracellular Matrix Reorganization During Wound Healing and Its Impact on Abnormal Scarring

PubMed Central

Xue, Meilang; Jackson, Christopher J.

2015-01-01

Significance: When a cutaneous injury occurs, the wound heals via a dynamic series of physiological events, including coagulation, granulation tissue formation, re-epithelialization, and extracellular matrix (ECM) remodeling. The final stage can take many months, yet the new ECM forms a scar that never achieves the flexibility or strength of the original tissue. In certain circumstances, the normal scar is replaced by pathological fibrotic tissue, which results in hypertrophic or keloid scars. These scars cause significant morbidity through physical dysfunction and psychological stress. Recent Advances and Critical Issues: The cutaneous ECM comprises a complex assortment of proteins that was traditionally thought to simply provide structural integrity and scaffolding characteristics. However, recent findings show that the ECM has multiple functions, including, storage and delivery of growth factors and cytokines, tissue repair and various physiological functions. Abnormal ECM reconstruction during wound healing contributes to the formation of hypertrophic and keloid scars. Whereas adult wounds heal with scarring, the developing foetus has the ability to heal wounds in a scarless fashion by regenerating skin and restoring the normal ECM architecture, strength, and function. Recent studies show that the lack of inflammation in fetal wounds contributes to this perfect healing. Future Directions: Better understanding of the exact roles of ECM components in scarring will allow us to produce therapeutic agents to prevent hypertrophic and keloid scars. This review will focus on the components of the ECM and their role in both physiological and pathological (hypertrophic and keloid) cutaneous scar formation. PMID:25785236

Dual ECM Biomimetic Scaffolds for Dental Pulp Regenerative Applications

PubMed Central

Huang, Chun-Chieh; Narayanan, Raghuvaran; Warshawsky, Noah; Ravindran, Sriram

2018-01-01

Dental pulp is a highly vascularized and innervated tissue that provides sensitivity and vitality to the tooth. Chronic caries results in an infected pulp tissue prone to necrosis. Existing clinical treatments replace the living pulp tissue with a non-responsive resin filling resulting in loss of tooth vitality. Tissue engineering approaches to dental pulp tissue regeneration have been investigated to preserve tooth vitality and function. However, a critical criterion is the choice of growth factors that may promote mesenchymal stem cell differentiation and more importantly, vascularization. But, the problems associated with growth factor dosage, delivery, safety, immunological and ectopic complications affect their translatory potential severely. The purpose of this study is to develop, characterize and evaluate a biomimetic native extracellular matrix (ECM) derived dual ECM scaffold that consists of a pulp-specific ECM to promote MSC attachment, proliferation and differentiation and an endothelial ECM to promote migration of host endothelial cells and eventual vascularization in vivo. Our results show that the dual ECM scaffolds possess similar properties as a pulp-ECM scaffold to promote MSC attachment and odontogenic differentiation in vitro. Additionally, when implanted subcutaneously in a tooth root slice model in vivo, the dual ECM scaffolds promoted robust odontogenic differentiation of both dental pulp and bone marrow derived MSCs and also extensive vascularization when compared to respective controls. These scaffolds are mass producible for clinical use and hence have the potential to replace root canal therapy as a treatment for chronic dental caries. PMID:29887803

Stimulatory effects of advanced glycation endproducts (AGEs) on fibronectin matrix assembly.

PubMed

Pastino, Alexandra K; Greco, Todd M; Mathias, Rommel A; Cristea, Ileana M; Schwarzbauer, Jean E

2017-05-01

Advanced glycation endproducts (AGEs) are a heterogeneous group of compounds that form via non-enzymatic glycation of proteins throughout our lifespan and at a higher rate in certain chronic diseases such as diabetes. AGEs contribute to the progression of fibrosis, in part by stimulating cellular pathways that affect gene expression. Long-lived ECM proteins are targets for non-enzymatic glycation but the question of whether the AGE-modified ECM leads to excess ECM accumulation and fibrosis remains unanswered. In this study, cellular changes due to AGE accretion in the ECM were investigated. Non-enzymatic glycation of proteins in a decellularized fibroblast ECM was achieved by incubating the ECM in a solution of methylglyoxal (MGO). Mass spectrometry of fibronectin (FN) isolated from the glycated matrix identified twenty-eight previously unidentified MGO-derived AGE modification sites including functional sites such as the RGD integrin-binding sequence. Mesangial cells grown on the glycated, decellularized matrix assembled increased amounts of FN matrix. Soluble AGE-modified bovine serum albumin (BSA) also stimulated FN matrix assembly and this effect was reduced by function-blocking antibodies against the receptor for AGE (RAGE). These results indicate that cells respond to AGEs by increasing matrix assembly and that RAGE is involved in this response. This raises the possibility that the accumulation of ECM during the progression of fibrosis may be enhanced by cell interactions with AGEs on a glycated ECM. Copyright © 2016 Elsevier B.V. All rights reserved.

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot

PubMed Central

Glassman, Sydney I; Levine, Carrie R; DiRocco, Angela M; Battles, John J; Bruns, Thomas D

2016-01-01

After severe wildfires, pine recovery depends on ectomycorrhizal (ECM) fungal spores surviving and serving as partners for regenerating forest trees. We took advantage of a large, severe natural forest fire that burned our long-term study plots to test the response of ECM fungi to fire. We sampled the ECM spore bank using pine seedling bioassays and high-throughput sequencing before and after the California Rim Fire. We found that ECM spore bank fungi survived the fire and dominated the colonization of in situ and bioassay seedlings, but there were specific fire adapted fungi such as Rhizopogon olivaceotinctus that increased in abundance after the fire. The frequency of ECM fungal species colonizing pre-fire bioassay seedlings, post-fire bioassay seedlings and in situ seedlings were strongly positively correlated. However, fire reduced the ECM spore bank richness by eliminating some of the rare species, and the density of the spore bank was reduced as evidenced by a larger number of soil samples that yielded uncolonized seedlings. Our results show that although there is a reduction in ECM inoculum, the ECM spore bank community largely remains intact, even after a high-intensity fire. We used advanced techniques for data quality control with Illumina and found consistent results among varying methods. Furthermore, simple greenhouse bioassays can be used to determine which fungi will colonize after fires. Similar to plant seed banks, a specific suite of ruderal, spore bank fungi take advantage of open niche space after fires. PMID:26473720

Generating favorable growth factor and protease release profiles to enable extracellular matrix accumulation within an in vitro tissue engineering environment.

PubMed

Zhang, Xiaoqing; Battiston, Kyle G; Labow, Rosalind S; Simmons, Craig A; Santerre, J Paul

2017-05-01

Tissue engineering (particularly for the case of load-bearing cardiovascular and connective tissues) requires the ability to promote the production and accumulation of extracellular matrix (ECM) components (e.g., collagen, glycosaminoglycan and elastin). Although different approaches have been attempted in order to enhance ECM accumulation in tissue engineered constructs, studies of underlying signalling mechanisms that influence ECM deposition and degradation during tissue remodelling and regeneration in multi-cellular culture systems have been limited. The current study investigated vascular smooth muscle cell (VSMC)-monocyte co-culture systems using different VSMC:monocyte ratios, within a degradable polyurethane scaffold, to assess their influence on ECM generation and degradation processes, and to elucidate relevant signalling molecules involved in this in vitro vascular tissue engineering system. It was found that a desired release profile of growth factors (e.g. insulin growth factor-1 (IGF-1)) and hydrolytic proteases (e.g. matrix-metalloproteinases 2, 9, 13 and 14 (MMP2, MMP9, MMP13 and MMP14)), could be achieved in co-culture systems, yielding an accumulation of ECM (specifically for 2:1 and 4:1 VSMC:monocyte culture systems). This study has significant implications for the tissue engineering field (including vascular tissue engineering), not only because it identified important cytokines and proteases that control ECM accumulation/degradation within synthetic tissue engineering scaffolds, but also because the established culture systems could be applied to improve the development of different types of tissue constructs. Sufficient extracellular matrix accumulation within cardiovascular and connective tissue engineered constructs is a prerequisite for their appropriate function in vivo. This study established co-culture systems with tissue specific cells (vascular smooth muscle cells (VSMCs)) and defined ratios of immune cells (monocytes) to investigate extracellular matrix (ECM) generation and degradation processes, revealing important mechanisms underlying ECM turnover during vascular tissue regeneration/remodelling. A specific growth factor (IGF-1), as well as hydrolytic proteases (e.g. MMP2, MMP9, MMP13 and MMP14), were identified as playing important roles in these processes. ECM accumulation was found to be dependent on achieving a desired release profile of these ECM-promoting and ECM-degrading factors within the multi-cellular microenvironment. The findings enhance our understanding of ECM deposition and degradation during in vitro tissue engineering and would be applicable to the repair or regeneration of a variety of tissues. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Mef2c Regulates Transcription of the Extracellular Matrix Protein Cartilage Link Protein 1 in the Developing Murine Heart

PubMed Central

Phelps, Aimee L.; Ghatnekar, Angela V.; Barth, Jeremy L.; Norris, Russell A.; Wessels, Andy

2013-01-01

Cartilage Link Protein 1 (Crtl1) is an extracellular matrix (ECM) protein that stabilizes the interaction between hyaluronan and versican and is expressed in endocardial and endocardially-derived cells in the developing heart, including cells in the atrioventricular (AV) and outflow tract (OFT) cushions. Previous investigations into the transcriptional regulation of the Crtl1 gene have shown that Sox9 regulates Crtl1 expression in both cartilage and the AV valves. The cardiac transcription factor Mef2c is involved in the regulation of gene expression in cardiac and skeletal muscle cell lineages. In this study we have investigated the potential role of Mef2c in the regulation of ECM production in the endocardial and mesenchymal cell lineages of the developing heart. We demonstrate that the Crtl1 5′ flanking region contains two highly conserved Mef2 binding sites and that Mef2c is able to bind to these sites in vivo during cardiovascular development. Additionally, we show that Crtl1 transcription is dependent on Mef2c expression in fetal mitral valve interstitial cells (VICs). Combined, these findings highlight a new role for Mef2c in cardiac development and the regulation of cardiac extracellular matrix protein expression. PMID:23468913

75 FR 24641 - Order Finding That the HSC1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... commercial market (``ECM'') under sections 2(h)(3)--(5) of the Commodity Exchange Act (``CEA'' or the ``Act... (``Reauthorization Act'') \\4\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

75 FR 15635 - Delegations of Authority To Disclose Confidential Information

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-30

... significant price discovery contracts (``SPDCs'') on exempt commercial markets (``ECMs'') and, among other statutory amendments, adds ECMs with SPDCs to the definition of ``registered entity'' in section 1(a)(29) of the CEA.\\7\\ Accordingly, with respect to a contract that the Commission determines is a SPDC, the ECM...

42 CFR 456.725 - Funding of ECM system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 4 2014-10-01 2014-10-01 false Funding of ECM system. 456.725 Section 456.725 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Claims Management System for Outpatient Drug Claims § 456.725 Funding of ECM system. (a) For funds...

42 CFR 456.725 - Funding of ECM system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 4 2012-10-01 2012-10-01 false Funding of ECM system. 456.725 Section 456.725 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Claims Management System for Outpatient Drug Claims § 456.725 Funding of ECM system. (a) For funds...

The Air Force Did Not Monitor the Energy Savings Performance Contract at Joint Base McGuire

DTIC Science & Technology

2015-06-29

4: Chiller Plant Upgrade (see Figure 2) • ECM 5: Natural Gas Rate Reduction4 3 ETL 08-5, April 14, 2008; ETL 11-24, July 18, 2011; and ETL 13-13...2009. 6 DOE contract number: DE-AM36-99EE73682. Figure 1. ECM 1 Boiler in Building 2784 Source: DoD OIG Figure 2. ECM 4 Chiller in Building 1908...personnel were unaware of the problem. Furthermore, while reviewing ECM-4, the chiller plant upgrade, we found an additional boiler that contractor

Electrochromic mirror using viologen-anchored nanoparticles

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

Kim, Han Na; University of Science and Technology, Advanced Device Technology, 217 Gajeong-roYuseong-gu, Daejeon 305-350; Cho, Seong M.

Highlights: • Three types of ECM device were fabricated using viologen-anchored ECDs. • The devices were investigated according to their optical structures. • The anti-reflection material affects the reflectance and the coloration efficiency. • The device design of ECMs is a crucial factor for clear reflected images. - Abstract: Electrochromic mirrors (ECMs) that are used in automobile mirrors need to have high reflectance, a high contrast ratio, and a clear image. In particular, it is critical that distortions of clear images are minimized for safety. Therefore, an ECM is fabricated using viologen-anchored nanoparticles and a magnesium fluoride (MgF{sub 2}) layermore » with an anti-reflection function. The ECM has approximately 30.42% in the reflectance dynamic range and 125 cm{sup 2}/C high coloration efficiency.« less

Decellularized Tendon Extracellular Matrix—A Valuable Approach for Tendon Reconstruction?

PubMed Central

Schulze-Tanzil, Gundula; Al-Sadi, Onays; Ertel, Wolfgang; Lohan, Anke

2012-01-01

Tendon healing is generally a time-consuming process and often leads to a functionally altered reparative tissue. Using degradable scaffolds for tendon reconstruction still remains a compromise in view of the required high mechanical strength of tendons. Regenerative approaches based on natural decellularized allo- or xenogenic tendon extracellular matrix (ECM) have recently started to attract interest. This ECM combines the advantages of its intrinsic mechanical competence with that of providing tenogenic stimuli for immigrating cells mediated, for example, by the growth factors and other mediators entrapped within the natural ECM. A major restriction for their therapeutic application is the mainly cell-associated immunogenicity of xenogenic or allogenic tissues and, in the case of allogenic tissues, also the risk of disease transmission. A survey of approaches for tendon reconstruction using cell-free tendon ECM is presented here, whereby the problems associated with the decellularization procedures, the success of various recellularization strategies, and the applicable cell types will be thoroughly discussed. Encouraging in vivo results using cell-free ECM, as, for instance, in rabbit models, have already been reported. However, in comparison to native tendon, cells remain mostly inhomogeneously distributed in the reseeded ECM and do not align. Hence, future work should focus on the optimization of tendon ECM decellularization and recolonization strategies to restore tendon functionality. PMID:24710540

Influence of residual composition on the structure and properties of extracellular matrix derived hydrogels.

PubMed

Claudio-Rizo, Jesús A; Rangel-Argote, Magdalena; Castellano, Laura E; Delgado, Jorge; Mata-Mata, José L; Mendoza-Novelo, Birzabith

2017-10-01

In this work, hydrolysates of extracellular matrix (hECM) were obtained from rat tail tendon (TR), bovine Achilles tendon (TAB), porcine small intestinal submucosa (SIS) and bovine pericardium (PB), and they were polymerized to generate ECM hydrogels. The composition of hECM was evaluated by quantifying the content of sulphated glycosaminoglycans (sGAG), fibronectin and laminin. The polymerization process, structure, physicochemical properties, in vitro degradation and biocompatibility were studied and related to their composition. The results indicated that the hECM derived from SIS and PB were significantly richer in sGAG, fibronectin and laminin, than those derived from TAB and TR. These differences in hECM composition influenced the polymerization and the structural characteristics of the fibrillar gel network. Consequently, the swelling, mechanics and degradation of the hydrogels showed a direct relationship with the remaining composition. Moreover, the cytocompatibility and the secretion of transforming growth factor beta-1 (TGF-β1) by macrophages were enhanced in hydrogels with the highest residual content of ECM biomolecules. The results of this work evidenced the role of the ECM molecules remaining after both decellularization and hydrolysis steps to produce tissue derived hydrogels with structure and properties tailored to enhance their performance in tissue engineering and regenerative medicine applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Ectomycorrhizal Fungal Communities and Enzymatic Activities Vary across an Ecotone between a Forest and Field

PubMed Central

Rúa, Megan A.; Moore, Becky; Hergott, Nicole; Van, Lily; Jackson, Colin R.; Hoeksema, Jason D.

2015-01-01

Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing for <5 years. ECM community and environmental characteristics influenced enzyme activity in the field, indicating that controls on enzyme activity may be intricately linked to the ECM community, but this was not true in the forest. Members of the Russulaceae were associated with increased phenol oxidase activity and decreased peroxidase activity in the field. Members of the Atheliaceae were particularly susceptible to changes in their abiotic environment, but this did not mediate differences in enzyme activity. These results emphasize the complex nature of factors that dictate the distribution of ECM and activity of their enzymes across a habitat boundary. PMID:29376908

Susceptibility of ectomycorrhizal fungi to soil heating.

PubMed

Kipfer, Tabea; Egli, Simon; Ghazoul, Jaboury; Moser, Barbara; Wohlgemuth, Thomas

2010-01-01

Ectomycorrhizal (EcM) fungi are an important biotic factor for successful tree recruitment because they enhance plant growth and alleviate drought stress of their hosts. Thus, EcM propagules are expected to be a key factor for forest regeneration after major disturbance events such as stand-replacing forest fires. Yet the susceptibility of soil-borne EcM fungi to heat is unclear. In this study, we investigated the heat tolerance of EcM fungi of Scots pine (Pinus sylvestris L., Pinaceae). Soil samples of three soil depths were heated to the temperature of 45, 60 and 70 °C, respectively, and surviving EcM fungi were assessed by a bioassay using Scots pine as an experimental host plant. EcM species were identified by a combination of morphotyping and sequencing of the ITS region. We found that mean number of species per sample was reduced by the 60 and 70 °C treatment, but not by the 45 °C treatment. Species composition changed due to heat. While some EcM fungi species did not survive heating, the majority of species was also found in the heated samples. The most frequent species in the heat treatment were Rhizopogon roseolus, Cenococcum geophilum and several unidentified species. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Programmable Control in Extracellular Matrix-mimicking Polymer Hydrogels.

PubMed

Hof, Kevin S; Bastings, Maartje M C

2017-06-28

The extracellular matrix (ECM) and cells have a reciprocal relationship, one shapes the other and vice versa. One of the main challenges of synthetic material systems for developmental cell culturing, organoid and stem cell work includes the implementation of this reciprocal nature. The largest hurdle to achieve true cell-instructive materials in biomaterials engineering is a lack of spatial and temporal control over material properties and the display of bioactive signals compared to the natural cell environment. ECM-mimicking hydrogels have been developed using a wide range of polymers, assembly and cross-linking strategies. While our synthetic toolbox is larger than nature, often our systems underperform when compared to ECM systems with natural components like Matrigel. Material properties and three-dimensional structure ill-represent the three-dimensional ECM reciprocal nature and ligand presentation is an oversimplified version of the complexity found in nature. We hypothesize that the lack of programmable control in properties and ligand presentation forms the basis of this mismatch in performance and analyze the presence of control in current state of the art ECM-mimicking systems based on covalent, supramolecular and recombinant polymers. We conclude that through combining the dynamics of supramolecular materials, robustness from covalent systems and the programmable spatial control of bio-activation in recombinant ECM materials, the optimal synthetic artificial ECM could be assembled.

Designing ECM-mimetic Materials Using Protein Engineering

PubMed Central

Cai, Lei; Heilshorn, Sarah C.

2014-01-01

The natural extracellular matrix (ECM), with its multitude of evolved cell-instructive and cell-responsive properties, provides inspiration and guidelines for the design of engineered biomaterials. One strategy to create ECM-mimetic materials is the modular design of protein-based engineered ECM (eECM) scaffolds. This modular design strategy involves combining multiple protein domains with different functionalities into a single, modular polymer sequence, resulting in a multifunctional matrix with independent tunability of the individual domain functions. These eECMs often enable decoupled control over multiple material properties for fundamental studies of cell-matrix interactions. In addition, since the eECMs are frequently composed entirely of bioresorbable amino acids, these matrices have immense clinical potential for a variety of regenerative medicine applications. This brief review demonstrates how fundamental knowledge gained from structure-function studies of native proteins can be exploited in the design of novel protein-engineered biomaterials. While the field of protein-engineered biomaterials has existed for over 20 years, the community is only now beginning to fully explore the diversity of functional peptide modules that can be incorporated into these materials. We have chosen to highlight recent examples that either (1) demonstrate exemplary use as matrices with cell-instructive and cell-responsive properties or (2) demonstrate outstanding creativity in terms of novel molecular-level design and macro-level functionality. PMID:24365704

Proteomic Analysis of the Extracellular Matrix Produced by Mesenchymal Stromal Cells: Implications for Cell Therapy Mechanism

PubMed Central

Harvey, Adam; Yen, Ten-Yang; Aizman, Irina; Tate, Ciara; Case, Casey

2013-01-01

Mesenchymal stromal cells (MSCs) transiently transfected with notch1 intracellular domain (NICD) are beneficial for neurological disorders as observed in several preclinical studies. Extracellular matrix (ECM) derived from NICD-transfected MSCs has been previously shown to support in vitro neural cell growth and survival better than that of un-transfected MSCs. To understand the underlying mechanism(s) by which NICD-transfected MSC-derived ECM supports neural cell growth and survival, we investigated the differences in NICD-transfected MSC- and MSC-derived ECM protein quantity and composition. To compare the ECM derived from MSCs and NICD-transfected MSCs, the proteins were sequentially solubilized using sodium dodecyl sulfate (SDS) and urea, quantified, and compared across four human donors. We then analyzed ECM proteins using either in-gel digests or in-solution surfactant-assisted trypsin digests (SAISD) coupled with reverse phase nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Analyses using nLC-MS/MS identified key components of ECM from NICD-transfected MSCs and un-transfected MSCs and revealed significant differences in their respective compositions. This work provides a reproducible method for identifying and comparing in vitro cell-derived ECM proteins, which is crucial for exploring the mechanisms underlying cellular therapy. PMID:24244468

Preparation of decellularized vascular matrix by co-crosslinking of procyanidins and glutaraldehyde.

PubMed

Wang, Xiaotong; Ma, Bing; Chang, Jiang

2015-01-01

Vascular extracellular matrices (vECMs) have shown potential for small-diameter blood vessel tissue engineering applications. However, problems such as chemical instability and easy calcification are still remained. Chemical crosslinking using crosslinkers such as glutaraldehyde (GA) can improve mechanical properties and proteolysis resistance of vECMs, but leads to calcification and cytotoxicity. Procyanidins (PC) can crosslink ECMs with anti-calcification property and cytocompatibility, but the mechanical properties and chemical stability are unsatisfactory. A novel co-crosslinking technique using PC and GA was developed, which combines the advantages of both PC and GA for enhancing mechanical properties and stability of vECMs with reduced calcification and cytotoxicity. Fresh carotid were decellularized and then crosslinked by PC and subsequent GA for 6 h respectively. The mechanical properties, dynamic release of PC, enzymatic degradation, calcification and cytotoxicity of crosslinked samples were evaluated. The co-crosslinked vECMs showed enhanced tensile strength, chemical and biological stability, comparable anti-calcification property as compared to pure PC-crosslinked samples. Cytotoxicity assay showed that the co-crosslinked vECMs were cytocompatible for supporting the adhesion and proliferation of HUVECs. Co-crosslinking with PC and GA might be a useful method for preparation of vECM scaffolds with potential applications in small-diameter blood vessel tissue engineering.

Three distinct cell populations express extracellular matrix proteins and increase in number during skeletal muscle fibrosis.

PubMed

Chapman, Mark A; Mukund, Kavitha; Subramaniam, Shankar; Brenner, David; Lieber, Richard L

2017-02-01

Tissue extracellular matrix (ECM) provides structural support and creates unique environments for resident cells (Bateman JF, Boot-Handford RP, Lamandé SR. Nat Rev Genet 10: 173-183, 2009; Kjaer M. Physiol Rev 84: 649-98, 2004). However, the identities of cells responsible for creating specific ECM components have not been determined. In striated muscle, the identity of these cells becomes important in disease when ECM changes result in fibrosis and subsequent increased tissue stiffness and dysfunction. Here we describe a novel approach to isolate and identify cells that maintain the ECM in both healthy and fibrotic muscle. Using a collagen I reporter mouse, we show that there are three distinct cell populations that express collagen I in both healthy and fibrotic skeletal muscle. Interestingly, the number of collagen I-expressing cells in all three cell populations increases proportionally in fibrotic muscle, indicating that all cell types participate in the fibrosis process. Furthermore, while some profibrotic ECM and ECM-associated genes are significantly upregulated in fibrotic muscle, the fibrillar collagen gene expression profile is not qualitatively altered. This suggests that muscle fibrosis in this model results from an increased number of collagen I-expressing cells and not the initiation of a specific fibrotic collagen gene expression program. Finally, in fibrotic muscle, we show that these collagen I-expressing cell populations differentially express distinct ECM proteins-fibroblasts express the fibrillar components of ECM, fibro/adipogenic progenitors cells differentially express basal laminar proteins, and skeletal muscle progenitor cells differentially express genes important for the satellite cell. Copyright © 2017 the American Physiological Society.

Endothelin-1 Mediated Induction of Extracellular Matrix Genes in Strial Marginal Cells Underlies Strial Pathology in Alport Mice

PubMed Central

Meehan, Daniel T.; Delimont, Duane; Dufek, Brianna; Zallocchi, Marisa; Phillips, Grady; Gratton, Michael Anne; Cosgrove, Dominic

2016-01-01

Alport syndrome, a type IV collagen disorder, manifests as glomerular disease associated with hearing loss with thickening of the glomerular and strial capillary basement membranes (SCBMs). We have identified a role for endothelin-1 (ET-1) activation of endothelin A receptors (ETARs) in glomerular pathogenesis. Here we explore whether ET-1 plays a role in strial pathology. Wild type (WT) and Alport mice were treated with the ETAR antagonist, sitaxentan. The stria vascularis was analyzed for SCBM thickness and for extracellular matrix (ECM) proteins. Additional WT and Alport mice were exposed to noise or hypoxia and the stria analyzed for hypoxia-related and ECM genes. A strial marginal cell line cultured under hypoxic conditions, or stimulated with ET-1 was analyzed for expression of hypoxia-related and ECM transcripts. Noise exposure resulted in significantly elevated ABR thresholds in Alport mice relative to wild type littermates. Alport stria showed elevated expression of collagen α1(IV), laminin α2, and laminin α5 proteins relative to WT. SCBM thickening and elevated ECM protein expression was ameliorated by ETAR blockade. Stria from normoxic Alport mice and hypoxic WT mice showed upregulation of hypoxia-related, ECM, and ET-1 transcripts. Both ET-1 stimulation and hypoxia up-regulated ECM transcripts in cultured marginal cells. We conclude that ET-1 mediated activation of ETARs on strial marginal cells results in elevated expression of ECM genes and thickening of the SCBMs in Alport mice. SCBM thickening results in hypoxic stress further elevating ECM and ET-1 gene expression, exacerbating strial pathology. PMID:27553900

Nitrogen Ion Form and Spatio-temporal Variation in Root Distribution Mediate Nitrogen Effects on Lifespan of Ectomycorrhizal Roots

NASA Astrophysics Data System (ADS)

Kou, L.; McCormack, M. L.; Chen, W.; Guo, D.; Wang, H.; Li, S.; Gao, W.; Yang, H.

2017-12-01

Background and Aims Absorptive roots active in soil resource uptake are often intimately associated with mycorrhizal fungi, yet it remains unclear how nitrogen (N) loading affects lifespan of absorptive roots associating with ectomycorrhizal (ECM) fungi. Methods Through a three-year minirhizotron experiment, we investigated the responses of ECM lifespan to different rates of N addition and examined the roles of N ion form, rooting depth, seasonal root cohort, and ECM morphotype in mediating the N effects on ECM lifespan in a slash pine (Pinus elliottii) forest in subtropical China. Results High rates of NH4Cl significantly decreased foliar P concentrations and increased foliar N: P ratios, and mean ECM lifespan was negatively correlated to foliar P concentration. N additions generally increased the lifespan of most ectomycorrhizas, but the specific differences were context dependent. N rates and forms exerted significant positive effects on ECM lifespan with stronger effects occurring at high N rates and under ammonium N addition. N additions extended lifespan of ectomycorrhizas in shallower soil and born in spring and autumn, but shortened lifespan of ectomycorrhizas in deeper soil and born in summer and winter. N additions reduced lifespan of dichotomous ectomycorrhizas, but increased lifespan of coralloid ectomycorrhizas. Conclusions The increased ECM lifespan in response to N additions may primarily be driven by the persistent and aggravated P limitation to plants. Our findings highlight the importance of environmental contexts in controlling ECM lifespan and the need to consider potential differences among mycorrhizal morphotypes when studying N—lifespan relationships of absorptive roots in the context of N deposition.

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold

PubMed Central

Kim, Eun Na; Sung, Myung Whun; Kwon, Tack-Kyun; Cho, Yong Woo; Kwon, Seong Keun

2016-01-01

Vocal fold paralysis results from various etiologies and can induce voice changes, swallowing complications, and issues with aspiration. Vocal fold paralysis is typically managed using injection laryngoplasty with fat or synthetic polymers. Injection with autologous fat has shown excellent biocompatibility. However, it has several disadvantages such as unpredictable resorption rate, morbidities associated with liposuction procedure which has to be done in operating room under general anesthesia. Human adipose-derived extracellular matrix (ECM) grafts have been reported to form new adipose tissue and have greater biostability than autologous fat graft. Here, we present an injectable hydrogel that is constructed from adipose tissue derived soluble extracellular matrix (sECM) and methylcellulose (MC) for use in vocal fold augmentation. Human sECM derived from adipose tissue was extracted using two major steps—ECM was isolated from human adipose tissue and was subsequently solubilized. Injectable sECM/MC hydrogels were prepared by blending of sECM and MC. Sustained vocal fold augmentation and symmetric vocal fold vibration were accomplished by the sECM/MC hydrogel in paralyzed vocal fold which were confirmed by laryngoscope, histology and a high-speed imaging system. There were increased number of collagen fibers and fatty granules at the injection site without significant inflammation or fibrosis. Overall, these results indicate that the sECM/MC hydrogel can enhance vocal function in paralyzed vocal folds without early resorption and has potential as a promising material for injection laryngoplasty for stable vocal fold augmentation which can overcome the shortcomings of autologous fat such as unpredictable duration and morbidity associated with the fat harvest. PMID:27768757

Three distinct cell populations express extracellular matrix proteins and increase in number during skeletal muscle fibrosis

PubMed Central

Chapman, Mark A.; Mukund, Kavitha; Subramaniam, Shankar; Brenner, David

2017-01-01

Tissue extracellular matrix (ECM) provides structural support and creates unique environments for resident cells (Bateman JF, Boot-Handford RP, Lamandé SR. Nat Rev Genet 10: 173–183, 2009; Kjaer M. Physiol Rev 84: 649–98, 2004). However, the identities of cells responsible for creating specific ECM components have not been determined. In striated muscle, the identity of these cells becomes important in disease when ECM changes result in fibrosis and subsequent increased tissue stiffness and dysfunction. Here we describe a novel approach to isolate and identify cells that maintain the ECM in both healthy and fibrotic muscle. Using a collagen I reporter mouse, we show that there are three distinct cell populations that express collagen I in both healthy and fibrotic skeletal muscle. Interestingly, the number of collagen I-expressing cells in all three cell populations increases proportionally in fibrotic muscle, indicating that all cell types participate in the fibrosis process. Furthermore, while some profibrotic ECM and ECM-associated genes are significantly upregulated in fibrotic muscle, the fibrillar collagen gene expression profile is not qualitatively altered. This suggests that muscle fibrosis in this model results from an increased number of collagen I-expressing cells and not the initiation of a specific fibrotic collagen gene expression program. Finally, in fibrotic muscle, we show that these collagen I-expressing cell populations differentially express distinct ECM proteins—fibroblasts express the fibrillar components of ECM, fibro/adipogenic progenitors cells differentially express basal laminar proteins, and skeletal muscle progenitor cells differentially express genes important for the satellite cell. PMID:27881411

Developing Extracellular Matrix Technology to Treat Retinal or Optic Nerve Injury

PubMed Central

van der Merwe, Yolandi

2015-01-01

Abstract Adult mammalian CNS neurons often degenerate after injury, leading to lost neurologic functions. In the visual system, retinal or optic nerve injury often leads to retinal ganglion cell axon degeneration and irreversible vision loss. CNS axon degeneration is increasingly linked to the innate immune response to injury, which leads to tissue-destructive inflammation and scarring. Extracellular matrix (ECM) technology can reduce inflammation, while increasing functional tissue remodeling, over scarring, in various tissues and organs, including the peripheral nervous system. However, applying ECM technology to CNS injuries has been limited and virtually unstudied in the visual system. Here we discuss advances in deriving fetal CNS-specific ECMs, like fetal porcine brain, retina, and optic nerve, and fetal non-CNS-specific ECMs, like fetal urinary bladder, and the potential for using tissue-specific ECMs to treat retinal or optic nerve injuries in two platforms. The first platform is an ECM hydrogel that can be administered as a retrobulbar, periocular, or even intraocular injection. The second platform is an ECM hydrogel and polymer “biohybrid” sheet that can be readily shaped and wrapped around a nerve. Both platforms can be tuned mechanically and biochemically to deliver factors like neurotrophins, immunotherapeutics, or stem cells. Since clinical CNS therapies often use general anti-inflammatory agents, which can reduce tissue-destructive inflammation but also suppress tissue-reparative immune system functions, tissue-specific, ECM-based devices may fill an important need by providing naturally derived, biocompatible, and highly translatable platforms that can modulate the innate immune response to promote a positive functional outcome. PMID:26478910

Mesenchymal stromal cells improve human islet function through released products and extracellular matrix.

PubMed

Arzouni, Ahmed A; Vargas-Seymour, Andreia; Rackham, Chloe L; Dhadda, Paramjeet; Huang, Guo-Cai; Choudhary, Pratik; Nardi, Nance; King, Aileen J F; Jones, Peter M

2017-12-01

The aims of the present study were (i) to determine whether the reported beneficial effects of mesenchymal stromal cells (MSCs) on mouse islet function extend to clinically relevant human tissues (islets and MSCs), enabling translation into improved protocols for clinical human islet transplantation; and (ii) to identify possible mechanisms through which human MSCs influence human islet function. Human islets were co-cultured with human adipose tissue-derived MSCs (hASCs) or pre-treated with its products - extracellular matrix (ECM) and annexin A1 (ANXA1). Mouse islets were pre-treated with mouse MSC-derived ECM. Islet insulin secretory function was assessed in vitro by radioimmunoassay. Quantitative RT-PCR was used to screen human adipMSCs for potential ligands of human islet G-protein-coupled receptors. We show that co-culture with hASCs improves human islet secretory function in vitro , as measured by glucose-stimulated insulin secretion, confirming previous reports using rodent tissues. Furthermore, we demonstrate that these beneficial effects on islet function can be partly attributed to the MSC-derived products ECM and ANXA1. Our results suggest that hASCs have the potential to improve the quality of human islets isolated for transplantation therapy of Type 1 diabetes. Furthermore, it may be possible to achieve improvements in human islet quality in a cell-free culture system by using the MSC-derived products ANXA1 and ECM. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

In Vivo engineering of the vocal fold ECM with injectable HA hydrogels-late effects on tissue repair and biomechanics in a rabbit model.

PubMed

Thibeault, Susan L; Klemuk, Sarah A; Chen, Xia; Quinchia Johnson, Beatriz H

2011-03-01

To determine if the utilization of injectable chemically modified hyaluronan (HA) derivative at the time of intentional vocal fold resection may facilitate wound repair and preserve the unique viscoelastic properties of the extracellular matrix (ECM) and lamina propria 6 months after treatment. Prospective, controlled animal study. Twelve rabbit vocal folds were biopsied bilaterally, and the left side of vocal fold was treated with Extracel, an injectable, chemically modified HA derivative, and the right side of vocal fold was injected with saline as control at the time of resection. Animals were sacrificed 6 months after biopsy and injection. Outcomes measured include transcription levels for procollagen, fibronectin, fibromodulin, transforming growth factor beta one (TGF-β1), HA synthase, and hyaluronidase, and tissue biomechanics-viscosity and elasticity. Extracel-treated vocal folds were found to have significantly less fibrosis than saline-treated controls. Extracel-treated vocal folds had significantly improved biomechanical properties of elasticity and viscosity. Significantly decreased levels of fibronectin, fibromodulin, TGF-β1, procollagen I, and HA synthase were measured. Prophylactic in vivo manipulation of the ECM with an injectable HA hydrogel appears to induce vocal fold tissue regeneration to yield improved tissue composition and biomechanical properties at 6 months. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

75 FR 56513 - Orders Regarding the Treatment of Petitions Seeking Grandfather Relief for Exempt Commercial...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... for relief, identified with ``ECM/EBOT Grandfather Relief'' in the subject line, whichever is... exempt market categories--exempt commercial markets (``ECMs'') and exempt boards of trade (``EBOTs... strike CEA Section 2(h)(3)-(7) and, thus, eliminate the ECM category.\\6\\ Similarly, Section 734 of the...

78 FR 20087 - Privacy Act of 1974; Proposed New System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

... is comprised of two components--Enterprise Content Management (ECM) and the Account Management System (AMS). The heart of the system is the ECM component, which manages the workflows that were developed..., digital media, and/or CD-ROM. PAS is a customized module within USDA's Enterprise Content Management (ECM...

The Strategic Association between Enterprise Content Management and Decision Support

ERIC Educational Resources Information Center

Alalwan, Jaffar Ahmad

2012-01-01

To deal with the increasing information overload and with the structured and unstructured data complexity, many organizations have implemented enterprise content management (ECM) systems. Published research on ECM so far is very limited and reports on ECM implementations have been scarce until recently (Tyrvainen et al. 2006). However, the little…

76 FR 35372 - Effective Date for Swap Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

... on an electronic trading facility (called exempt commercial markets, or ``ECMs''); \\28\\ 7 U.S.C. 2(h... it would extend grandfather relief to ECMs and EBOTs provided that certain conditions are met. See... electronic trading facility that, as of July 15, 2011, is not already operating as an ECM pursuant to CEA...

75 FR 24606 - Order Finding That the TCO Financial Basis Contract Traded on the IntercontinentalExchange, Inc...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

...'') contract traded on the IntercontinentalExchange, Inc. (``ICE''), an exempt commercial market (``ECM...\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs...

76 FR 80233 - Amendment to July 14, 2011 Order for Swap Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-23

... amendment to agricultural swaps; and, (3) the expiry date applicable to exempt commercial markets (``ECMs... on exempt and excluded commodities, may trade on either a DCM, ECM or exempt board of trade (``EBOT... agricultural commodities on ECMs or EBOTs.\\35\\ Nothing in the Notice or the Commission's recently promulgated...

75 FR 24619 - Order Finding That the Permian Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

...'') contract traded on the IntercontinentalExchange, Inc. (``ICE''), an exempt commercial market (``ECM...\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price [[Page 24620

Influence of long-term repeated prescribed burning on mycelial communities of ectomycorrhizal fungi.

PubMed

Bastias, Brigitte A; Xu, Zhihong; Cairney, John W G

2006-01-01

To demonstrate the efficacy of direct DNA extraction from hyphal ingrowth bags for community profiling of ectomycorrhizal (ECM) mycelia in soil, we applied the method to investigate the influence of long-term repeated prescribed burning on an ECM fungal community. DNA was extracted from hyphal ingrowth bags buried in forest plots that received different prescribed burning treatments for 30 yr, and denaturing gradient gel electrophoresis (DGGE) profiles of partial fungal rDNA internal transcribed spacer (ITS) regions were compared. Restriction fragment length polymorphism (RFLP) and sequence analyses were also used to compare clone assemblages between the treatments. The majority of sequences derived from the ingrowth bags were apparently those of ECM fungi. DGGE profiles for biennially burned plots were significantly different from those of quadrennially burned and unburned control plots. Analysis of clone assemblages indicated that this reflected altered ECM fungal community composition. The results indicate that hyphal ingrowth bags represent a useful method for investigation of ECM mycelial communities, and that frequent long-term prescribed burning can influence below-ground ECM fungal communities.

Extraction and Assembly of Tissue-Derived Gels for Cell Culture and Tissue Engineering

PubMed Central

Uriel, Shiri; Labay, Edwardine; Francis-Sedlak, Megan; Moya, Monica L.; Weichselbaum, Ralph R.; Ervin, Natalia; Cankova, Zdravka

2009-01-01

Interactions with the extracellular matrix (ECM) play an important role in regulating cell function. Cells cultured in, or on, three-dimensional ECM recapitulate similar features to those found in vivo that are not present in traditional two-dimensional culture. In addition, both natural and synthetic materials containing ECM components have shown promise in a number of tissue engineering applications. Current materials available for cell culture and tissue engineering do not adequately reflect the diversity of ECM composition between tissues. In this paper, a method is presented for extracting solutions of proteins and glycoproteins from soft tissues and inducing assembly of these proteins into gels. The extracts contain ECM proteins specific to the tissue source with low levels of intracellular molecules. Gels formed from the tissue-derived extracts have nanostructure similar to ECM in vivo and can be used to culture cells as both a thin substrate coating and a thick gel. This technique could be used to assemble hydrogels with varying composition depending upon the tissue source, hydrogels for three-dimensional culture, as scaffolds for tissue engineering therapies, and to study cell–matrix interactions. PMID:19115821

Modulation of adhesion-dependent cAMP signaling by echistatin and alendronate

NASA Technical Reports Server (NTRS)

Fong, J. H.; Ingber, D. E.

1996-01-01

We measured intracellular cAMP levels in cells during attachment and spreading on different extracellular matrix (ECM) proteins. Increases in cAMP were observed within minutes when cells attached to fibronectin, vitronectin, and a synthetic RGD-containing fibronectin peptide (Petite 2000), but not when they adhered to another integrin alpha nu beta 3 ligand, echistatin. Because echistatin also inhibits bone resorption, we measured the effects of adding another osteoporosis inhibitor, alendronate, in this system. Alendronate inhibited the cAMP increase induced by ligands that primarily utilize integrin alpha nu beta 3 (vitronectin, Peptite 2000), but not by fibronectin which can also use integrin alpha 5 beta 1. These results show that cell adhesion to ECM can increase intracellular cAPM levels and raise the possibility that inhibitors of osteoporosis may act, in part, by preventing activation of this pathway by integrins.

Neuroimmunological Blood Brain Barrier Opening in Experimental Cerebral Malaria

PubMed Central

Baer, Kerstin; Mikolajczak, Sebastian A.; Kappe, Stefan H. I.; Frevert, Ute

2012-01-01

Plasmodium falciparum malaria is responsible for nearly one million annual deaths worldwide. Because of the difficulty in monitoring the pathogenesis of cerebral malaria in humans, we conducted a study in various mouse models to better understand disease progression in experimental cerebral malaria (ECM). We compared the effect on the integrity of the blood brain barrier (BBB) and the histopathology of the brain of P. berghei ANKA, a known ECM model, P. berghei NK65, generally thought not to induce ECM, P. yoelii 17XL, originally reported to induce human cerebral malaria-like histopathology, and P. yoelii YM. As expected, P. berghei ANKA infection caused neurological signs, cerebral hemorrhages, and BBB dysfunction in CBA/CaJ and Swiss Webster mice, while Balb/c and A/J mice were resistant. Surprisingly, PbNK induced ECM in CBA/CaJ mice, while all other mice were resistant. P. yoelii 17XL and P. yoelii YM caused lethal hyperparasitemia in all mouse strains; histopathological alterations, BBB dysfunction, or neurological signs were not observed. Intravital imaging revealed that infected erythrocytes containing mature parasites passed slowly through capillaries making intimate contact with the endothelium, but did not arrest. Except for relatively rare microhemorrhages, mice with ECM presented no obvious histopathological alterations that would explain the widespread disruption of the BBB. Intravital imaging did reveal, however, that postcapillary venules, but not capillaries or arterioles, from mice with ECM, but not hyperparasitemia, exhibit platelet marginalization, extravascular fibrin deposition, CD14 expression, and extensive vascular leakage. Blockage of LFA-1 mediated cellular interactions prevented leukocyte adhesion, vascular leakage, neurological signs, and death from ECM. The endothelial barrier-stabilizing mediators imatinib and FTY720 inhibited vascular leakage and neurological signs and prolonged survival to ECM. Thus, it appears that neurological signs and coma in ECM are due to regulated opening of paracellular-junctional and transcellular-vesicular fluid transport pathways at the neuroimmunological BBB. PMID:23133375

Comparative analysis of secretomes from Ectomycorrhizal fungi with an emphasis on small-secreted proteins

DOE PAGES

Pellegrin, Clement; Morin, Emmanuelle; Martin, Francis M.; ...

2015-11-18

Fungi are major players in the carbon cycle in forest ecosystems due to the wide range of interactions they have with plants either through soil degradation processes by litter decayers or biotrophic interactions with pathogenic and ectomycorrhizal symbionts. Secretion of fungal proteins mediates these interactions by allowing the fungus to interact with its environment and/or host. Ectomycorrhizal (ECM) symbiosis independently appeared several times throughout evolution and involves approximately 80% of trees. Despite extensive physiological studies on ECM symbionts, little is known about the composition and specificities of their secretomes. In this study, we used a bioinformatics pipeline to predict andmore » analyze the secretomes of 49 fungal species, including 11 ECM fungi, wood and soil decayers and pathogenic fungi to tackle the following questions: (1) Are there differences between the secretomes of saprophytic and ECM fungi? (2) Are small-secreted proteins (SSPs) more abundant in biotrophic fungi than in saprophytic fungi? and (3) Are there SSPs shared between ECM, saprotrophic and pathogenic fungi? We showed that the number of predicted secreted proteins is similar in the surveyed species, independently of their lifestyle. The secretome from ECM fungi is characterized by a restricted number of secreted CAZymes, but their repertoires of secreted proteases and lipases are similar to those of saprotrophic fungi. Focusing on SSPs, we showed that the secretome of ECM fungi is enriched in SSPs compared with other species. Most of the SSPs are coded by orphan genes with no known PFAM domain or similarities to known sequences in databases. Finally, based on the clustering analysis, we identified shared- and lifestyle-specific SSPs between saprotrophic and ECM fungi. The presence of SSPs is not limited to fungi interacting with living plants as the genome of saprotrophic fungi also code for numerous SSPs. As a result, ECM fungi shared lifestyle-specific SSPs likely involved in symbiosis that are good candidates for further functional analyses.« less

The mycorrhizal type governs root exudation and nitrogen uptake of temperate tree species.

PubMed

Liese, Rebecca; Lübbe, Torben; Albers, Nora W; Meier, Ina C

2018-01-01

Even though the two dominant mycorrhizal associations of temperate tree species differentially couple carbon (C) and nitrogen (N) cycles in temperate forests, systematic differences between the biogeochemical cycles of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species remain poorly described. A classification according to the mycorrhizal type offers the chance, though, to develop a global frame concept for the prediction of temperate ecosystem responses to environmental change. Focusing on the influence of mycorrhizal types on two key plant processes of biogeochemical cycling (root exudation and N acquisition), we investigated four temperate deciduous tree species per mycorrhizal type in a drought experiment in large mesocosms. We hypothesized that (H1) C loss by root exudation is higher in ECM than in AM trees, (H2) drought leads to higher reductions in root exudation of drought-sensitive ECM trees and (H3) inorganic N uptake is higher in AM than in ECM trees. In contradiction to H2, we found no systematic difference in root exudation between the mycorrhizal types at ample soil moisture, but almost twofold higher exudation in ECM trees when exposed to soil drought. In addition, photosynthetic C cost of root exudation strongly increased by ~10-fold in drought-treated ECM trees, while it only doubled in AM trees, which confirms H1. With respect to H3, we corroborated that AM trees had higher absolute and relative inorganic N acquisition rates than ECM trees, while the organic N uptake did not differ between mycorrhizal types. We conclude that ECM trees are less efficient in inorganic N uptake than AM trees, but ECM trees increase root C release as an adaptive response to dry soil to maintain hydraulic conductivity and/or nutrient availability. These systematic differences in key biogeochemical processes support hints on the key role of the mycorrhizal types in coupling C and N cycles in temperate forests. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparative analysis of secretomes from Ectomycorrhizal fungi with an emphasis on small-secreted proteins

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

Pellegrin, Clement; Morin, Emmanuelle; Martin, Francis M.

Fungi are major players in the carbon cycle in forest ecosystems due to the wide range of interactions they have with plants either through soil degradation processes by litter decayers or biotrophic interactions with pathogenic and ectomycorrhizal symbionts. Secretion of fungal proteins mediates these interactions by allowing the fungus to interact with its environment and/or host. Ectomycorrhizal (ECM) symbiosis independently appeared several times throughout evolution and involves approximately 80% of trees. Despite extensive physiological studies on ECM symbionts, little is known about the composition and specificities of their secretomes. In this study, we used a bioinformatics pipeline to predict andmore » analyze the secretomes of 49 fungal species, including 11 ECM fungi, wood and soil decayers and pathogenic fungi to tackle the following questions: (1) Are there differences between the secretomes of saprophytic and ECM fungi? (2) Are small-secreted proteins (SSPs) more abundant in biotrophic fungi than in saprophytic fungi? and (3) Are there SSPs shared between ECM, saprotrophic and pathogenic fungi? We showed that the number of predicted secreted proteins is similar in the surveyed species, independently of their lifestyle. The secretome from ECM fungi is characterized by a restricted number of secreted CAZymes, but their repertoires of secreted proteases and lipases are similar to those of saprotrophic fungi. Focusing on SSPs, we showed that the secretome of ECM fungi is enriched in SSPs compared with other species. Most of the SSPs are coded by orphan genes with no known PFAM domain or similarities to known sequences in databases. Finally, based on the clustering analysis, we identified shared- and lifestyle-specific SSPs between saprotrophic and ECM fungi. The presence of SSPs is not limited to fungi interacting with living plants as the genome of saprotrophic fungi also code for numerous SSPs. As a result, ECM fungi shared lifestyle-specific SSPs likely involved in symbiosis that are good candidates for further functional analyses.« less

Comparative Analysis of Secretomes from Ectomycorrhizal Fungi with an Emphasis on Small-Secreted Proteins

PubMed Central

Pellegrin, Clement; Morin, Emmanuelle; Martin, Francis M.; Veneault-Fourrey, Claire

2015-01-01

Fungi are major players in the carbon cycle in forest ecosystems due to the wide range of interactions they have with plants either through soil degradation processes by litter decayers or biotrophic interactions with pathogenic and ectomycorrhizal symbionts. Secretion of fungal proteins mediates these interactions by allowing the fungus to interact with its environment and/or host. Ectomycorrhizal (ECM) symbiosis independently appeared several times throughout evolution and involves approximately 80% of trees. Despite extensive physiological studies on ECM symbionts, little is known about the composition and specificities of their secretomes. In this study, we used a bioinformatics pipeline to predict and analyze the secretomes of 49 fungal species, including 11 ECM fungi, wood and soil decayers and pathogenic fungi to tackle the following questions: (1) Are there differences between the secretomes of saprophytic and ECM fungi? (2) Are small-secreted proteins (SSPs) more abundant in biotrophic fungi than in saprophytic fungi? and (3) Are there SSPs shared between ECM, saprotrophic and pathogenic fungi? We showed that the number of predicted secreted proteins is similar in the surveyed species, independently of their lifestyle. The secretome from ECM fungi is characterized by a restricted number of secreted CAZymes, but their repertoires of secreted proteases and lipases are similar to those of saprotrophic fungi. Focusing on SSPs, we showed that the secretome of ECM fungi is enriched in SSPs compared with other species. Most of the SSPs are coded by orphan genes with no known PFAM domain or similarities to known sequences in databases. Finally, based on the clustering analysis, we identified shared- and lifestyle-specific SSPs between saprotrophic and ECM fungi. The presence of SSPs is not limited to fungi interacting with living plants as the genome of saprotrophic fungi also code for numerous SSPs. ECM fungi shared lifestyle-specific SSPs likely involved in symbiosis that are good candidates for further functional analyses. PMID:26635749

Experimental Cerebral Malaria Pathogenesis—Hemodynamics at the Blood Brain Barrier

PubMed Central

Nacer, Adéla; Movila, Alexandru; Sohet, Fabien; Girgis, Natasha M.; Gundra, Uma Mahesh; Loke, P'ng; Daneman, Richard; Frevert, Ute

2014-01-01

Cerebral malaria claims the lives of over 600,000 African children every year. To better understand the pathogenesis of this devastating disease, we compared the cellular dynamics in the cortical microvasculature between two infection models, Plasmodium berghei ANKA (PbA) infected CBA/CaJ mice, which develop experimental cerebral malaria (ECM), and P. yoelii 17XL (PyXL) infected mice, which succumb to malarial hyperparasitemia without neurological impairment. Using a combination of intravital imaging and flow cytometry, we show that significantly more CD8+ T cells, neutrophils, and macrophages are recruited to postcapillary venules during ECM compared to hyperparasitemia. ECM correlated with ICAM-1 upregulation on macrophages, while vascular endothelia upregulated ICAM-1 during ECM and hyperparasitemia. The arrest of large numbers of leukocytes in postcapillary and larger venules caused microrheological alterations that significantly restricted the venous blood flow. Treatment with FTY720, which inhibits vascular leakage, neurological signs, and death from ECM, prevented the recruitment of a subpopulation of CD45hi CD8+ T cells, ICAM-1+ macrophages, and neutrophils to postcapillary venules. FTY720 had no effect on the ECM-associated expression of the pattern recognition receptor CD14 in postcapillary venules suggesting that endothelial activation is insufficient to cause vascular pathology. Expression of the endothelial tight junction proteins claudin-5, occludin, and ZO-1 in the cerebral cortex and cerebellum of PbA-infected mice with ECM was unaltered compared to FTY720-treated PbA-infected mice or PyXL-infected mice with hyperparasitemia. Thus, blood brain barrier opening does not involve endothelial injury and is likely reversible, consistent with the rapid recovery of many patients with CM. We conclude that the ECM-associated recruitment of large numbers of activated leukocytes, in particular CD8+ T cells and ICAM+ macrophages, causes a severe restriction in the venous blood efflux from the brain, which exacerbates the vasogenic edema and increases the intracranial pressure. Thus, death from ECM could potentially occur as a consequence of intracranial hypertension. PMID:25474413

Influence of the amyloid dye Congo red on curli, cellulose, and the extracellular matrix in E. coli during growth and matrix purification.

PubMed

Reichhardt, Courtney; McCrate, Oscar A; Zhou, Xiaoxue; Lee, Jessica; Thongsomboon, Wiriya; Cegelski, Lynette

2016-11-01

Microbial biofilms are communities of cells characterized by a hallmark extracellular matrix (ECM) that confers functional attributes to the community, including enhanced cohesion, adherence to surfaces, and resistance to external stresses. Understanding the composition and properties of the biofilm ECM is crucial to understanding how it functions and protects cells. New methods to isolate and characterize ECM are emerging for different biofilm systems. Solid-state nuclear magnetic resonance was used to quantitatively track the isolation of the insoluble ECM from the uropathogenic Escherichia coli strain UTI89 and understand the role of Congo red in purification protocols. UTI89 assembles amyloid-integrated biofilms when grown on YESCA nutrient agar. The ECM contains curli amyloid fibers and a modified form of cellulose. Biofilms formed by UTI89 and other E. coli and Salmonella strains are often grown in the presence of Congo red to visually emphasize wrinkled agar morphologies and to score the production of ECM. Congo red is a hallmark amyloid-binding dye and binds to curli, yet also binds to cellulose. We found that growth in Congo red enabled more facile extraction of the ECM from UTI89 biofilms and facilitates isolation of cellulose from the curli mutant, UTI89ΔcsgA. Yet, Congo red has no influence on the isolation of curli from curli-producing cells that do not produce cellulose. Sodium dodecyl sulfate can remove Congo red from curli, but not from cellulose. Thus, Congo red binds strongly to cellulose and possibly weakens cellulose interactions with the cell surface, enabling more complete removal of the ECM. The use of Congo red as an extracellular matrix purification aid may be applied broadly to other organisms that assemble extracellular amyloid or cellulosic materials. Graphical abstract Solid-state NMR was used to quantitatively track the isolation of the insoluble amyloid-associated ECM from uropathogenic E. coli and understand the role of Congo red in purification protocols.

Repair of traumatic skeletal muscle injury with bone-marrow-derived mesenchymal stem cells seeded on extracellular matrix.

PubMed

Merritt, Edward K; Cannon, Megan V; Hammers, David W; Le, Long N; Gokhale, Rohit; Sarathy, Apurva; Song, Tae J; Tierney, Matthew T; Suggs, Laura J; Walters, Thomas J; Farrar, Roger P

2010-09-01

Skeletal muscle injury resulting in tissue loss poses unique challenges for surgical repair. Despite the regenerative potential of skeletal muscle, if a significant amount of tissue is lost, skeletal myofibers will not grow to fill the injured area completely. Prior work in our lab has shown the potential to fill the void with an extracellular matrix (ECM) scaffold, resulting in restoration of morphology, but not functional recovery. To improve the functional outcome of the injured muscle, a muscle-derived ECM was implanted into a 1 x 1 cm(2), full-thickness defect in the lateral gastrocnemius (LGAS) of Lewis rats. Seven days later, bone-marrow-derived mesenchymal stem cells (MSCs) were injected directly into the implanted ECM. Partial functional recovery occurred over the course of 42 days when the LGAS was repaired with an MSC-seeded ECM producing 85.4 +/- 3.6% of the contralateral LGAS. This was significantly higher than earlier recovery time points (p < 0.05). The specific tension returned to 94 +/- 9% of the contralateral limb. The implanted MSC-seeded ECM had more blood vessels and regenerating skeletal myofibers than the ECM without cells (p < 0.05). The data suggest that the repair of a skeletal muscle defect injury by the implantation of a muscle-derived ECM seeded with MSCs can improve functional recovery after 42 days.

Preparation of hydroxy-PAAm hydrogels for decoupling the effects of mechanotransduction cues.

PubMed

Grevesse, Thomas; Versaevel, Marie; Gabriele, Sylvain

2014-08-28

It is now well established that many cellular functions are regulated by interactions of cells with physicochemical and mechanical cues of their extracellular matrix (ECM) environment. Eukaryotic cells constantly sense their local microenvironment through surface mechanosensors to transduce physical changes of ECM into biochemical signals, and integrate these signals to achieve specific changes in gene expression. Interestingly, physicochemical and mechanical parameters of the ECM can couple with each other to regulate cell fate. Therefore, a key to understanding mechanotransduction is to decouple the relative contribution of ECM cues on cellular functions. Here we present a detailed experimental protocol to rapidly and easily generate biologically relevant hydrogels for the independent tuning of mechanotransduction cues in vitro. We chemically modified polyacrylamide hydrogels (PAAm) to surmount their intrinsically non-adhesive properties by incorporating hydroxyl-functionalized acrylamide monomers during the polymerization. We obtained a novel PAAm hydrogel, called hydroxy-PAAm, which permits immobilization of any desired nature of ECM proteins. The combination of hydroxy-PAAm hydrogels with microcontact printing allows to independently control the morphology of single-cells, the matrix stiffness, the nature and the density of ECM proteins. We provide a simple and rapid method that can be set up in every biology lab to study in vitro cell mechanotransduction processes. We validate this novel two-dimensional platform by conducting experiments on endothelial cells that demonstrate a mechanical coupling between ECM stiffness and the nucleus.

Cell-derived micro-environment helps dental pulp stem cells promote dental pulp regeneration.

PubMed

Zhang, Xuexin; Li, Hui; Sun, Jingjing; Luo, Xiangyou; Yang, Hefeng; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

2017-10-01

The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture. DPM promoted the replication of DPSCs and exhibited retention of their mineralization. Then, the DPM-based culture strategy under odontogenic culture medium was further investigated, and the mineralization-related markers showed that DPSCs were regulated towards odontogenic differentiation. Dental pulp-like tissue with well-arranged ECM was harvested after a 2-month subcutaneous implantation in nude mice with DPM application. Additionally, DPSCs cultured on the plastic culture surface showed the up-regulation of mineralization makers in vitro, but there was a disorder in matrix formation and mineralization when the cells were cultured in vivo. DPM-based cultivation could serve as a cell niche and modulate DPSC behaviour, and this method also provided an alternative to harvest tissue-specific ECM and provided a strategy for ECM-cell interaction. © 2017 John Wiley & Sons Ltd.

Decellularized Human Kidney Cortex Hydrogels Enhance Kidney Microvascular Endothelial Cell Maturation and Quiescence.

PubMed

Nagao, Ryan J; Xu, Jin; Luo, Ping; Xue, Jun; Wang, Yi; Kotha, Surya; Zeng, Wen; Fu, Xiaoyun; Himmelfarb, Jonathan; Zheng, Ying

2016-10-01

The kidney peritubular microvasculature is highly susceptible to injury from drugs and toxins, often resulting in acute kidney injury and progressive chronic kidney disease. Little is known about the process of injury and regeneration of human kidney microvasculature, resulting from the lack of appropriate kidney microvascular models that can incorporate the proper cells, extracellular matrices (ECMs), and architectures needed to understand the response and contribution of individual vascular components in these processes. In this study, we present methods to recreate the human kidney ECM (kECM) microenvironment by fabricating kECM hydrogels derived from decellularized human kidney cortex. The majority of native matrix proteins, such as collagen-IV, laminin, and heparan sulfate proteoglycan, and their isoforms were preserved in similar proportions as found in normal kidneys. Human kidney peritubular microvascular endothelial cells (HKMECs) became more quiescent when cultured on this kECM gel compared with culture on collagen-I-assessed using phenotypic, genotypic, and functional assays; whereas human umbilical vein endothelial cells became stimulated on kECM gels. We demonstrate for the first time that human kidney cortex can form a hydrogel suitable for use in flow-directed microphysiological systems. Our findings strongly suggest that selecting the proper ECM is a critical consideration in the development of vascularized organs on a chip and carries important implications for tissue engineering of all vascularized organs.

Novel function of Extracellular matrix protein 1 in suppressing Th17 cell development in experimental autoimmune encephalomyelitis

PubMed Central

Su, Pan; Chen, Sheng; Zheng, Yu Han; Zhou, Hai Yan; Yan, Cheng Hua; Yu, Fang; Zhang, Ya Guang; He, Lan; Zhang, Yuan; Wang, Yanming; Wu, Lei; Wu, Xiaoai; Yu, Bingke; Ma, Li Yan; Yang, Zhiru; Wang, Jianhua; Zhao, Guixian; Zhu, Jinfang; Wu, Zhi-Ying; Sun, Bing

2016-01-01

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS characterized by demyelination and axonal damage. Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model for human MS. While Th17 cells are important for the disease induction, Th2 cells are inhibitory in this process. Here, we report the effect of a Th2 cell product, extracellular matrix protein 1 (ECM1), on the differentiation of Th17 cells and the development of experimental autoimmune encephalomyelitis (EAE). Our results demonstrated that ECM1 administration from day 1 to day 7 following the EAE induction could ameliorate the Th17 cell responses and EAE development in vivo. Further mechanism study revealed that ECM1 could interact with αv integrin on DC cells and block the αv integrin-mediated activation of latent TGF-β, resulting in an inhibition of Th17 differentiation at early stage of EAE induction. Furthermore, overexpression of ECM1 in vivo significantly inhibited Th17 cell response and EAE induction in ECM1 transgenic mouse. Overall, our work has identified a novel function of ECM1 in inhibiting Th17 differentiation in the EAE model, suggesting that ECM1 may have a potential to be used in clinical applications for understanding the pathogenesis of MS and its diagnosis. PMID:27316685

SPARC Regulates Transforming Growth Factor Beta Induced (TGFBI) Extracellular Matrix Deposition and Paclitaxel Response in Ovarian Cancer Cells.

PubMed

Tumbarello, David A; Andrews, Melissa R; Brenton, James D

2016-01-01

TGFBI has been shown to sensitize ovarian cancer cells to the cytotoxic effects of paclitaxel via an integrin receptor-mediated mechanism that modulates microtubule stability. Herein, we determine that TGFBI localizes within organized fibrillar structures in mesothelial-derived ECM. We determined that suppression of SPARC expression by shRNA decreased the deposition of TGFBI in mesothelial-derived ECM, without affecting its overall protein expression or secretion. Conversely, overexpression of SPARC increased TGFBI deposition. A SPARC-YFP fusion construct expressed by the Met5a cell line co-localized with TGFBI in the cell-derived ECM. Interestingly, in vitro produced SPARC was capable of precipitating TGFBI from cell lysates dependent on an intact SPARC carboxy-terminus with in vitro binding assays verifying a direct interaction. The last 37 amino acids of SPARC were shown to be required for the TGFBI interaction while expression of a SPARC-YFP construct lacking this region (aa 1-256) did not interact and co-localize with TGFBI in the ECM. Furthermore, ovarian cancer cells have a reduced motility and decreased response to the chemotherapeutic agent paclitaxel when plated on ECM derived from mesothelial cells lacking SPARC compared to control mesothelial-derived ECM. In conclusion, SPARC regulates the fibrillar ECM deposition of TGFBI through a novel interaction, subsequently influencing cancer cell behavior.

SPARC Regulates Transforming Growth Factor Beta Induced (TGFBI) Extracellular Matrix Deposition and Paclitaxel Response in Ovarian Cancer Cells

PubMed Central

Andrews, Melissa R.; Brenton, James D.

2016-01-01

TGFBI has been shown to sensitize ovarian cancer cells to the cytotoxic effects of paclitaxel via an integrin receptor-mediated mechanism that modulates microtubule stability. Herein, we determine that TGFBI localizes within organized fibrillar structures in mesothelial-derived ECM. We determined that suppression of SPARC expression by shRNA decreased the deposition of TGFBI in mesothelial-derived ECM, without affecting its overall protein expression or secretion. Conversely, overexpression of SPARC increased TGFBI deposition. A SPARC-YFP fusion construct expressed by the Met5a cell line co-localized with TGFBI in the cell-derived ECM. Interestingly, in vitro produced SPARC was capable of precipitating TGFBI from cell lysates dependent on an intact SPARC carboxy-terminus with in vitro binding assays verifying a direct interaction. The last 37 amino acids of SPARC were shown to be required for the TGFBI interaction while expression of a SPARC-YFP construct lacking this region (aa 1–256) did not interact and co-localize with TGFBI in the ECM. Furthermore, ovarian cancer cells have a reduced motility and decreased response to the chemotherapeutic agent paclitaxel when plated on ECM derived from mesothelial cells lacking SPARC compared to control mesothelial-derived ECM. In conclusion, SPARC regulates the fibrillar ECM deposition of TGFBI through a novel interaction, subsequently influencing cancer cell behavior. PMID:27622658

Growth Response of Drought-Stressed Pinus sylvestris Seedlings to Single- and Multi-Species Inoculation with Ectomycorrhizal Fungi

PubMed Central

Kipfer, Tabea; Wohlgemuth, Thomas; van der Heijden, Marcel G. A.; Ghazoul, Jaboury; Egli, Simon

2012-01-01

Many trees species form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve nutrient and water acquisition of their host. Until now it is unclear whether the species richness of ECM fungi is beneficial for tree seedling performance, be it during moist conditions or drought. We performed a pot experiment using Pinus sylvestris seedlings inoculated with four selected ECM fungi (Cenococcum geophilum, Paxillus involutus, Rhizopogon roseolus and Suillus granulatus) to investigate (i) whether these four ECM fungi, in monoculture or in species mixtures, affect growth of P. sylvestris seedlings, and (ii) whether this effect can be attributed to species number per se or to species identity. Two different watering regimes (moist vs. dry) were applied to examine the context-dependency of the results. Additionally, we assessed the activity of eight extracellular enzymes in the root tips. Shoot growth was enhanced in the presence of S. granulatus, but not by any other ECM fungal species. The positive effect of S. granulatus on shoot growth was more pronounced under moist (threefold increase) than under dry conditions (twofold increase), indicating that the investigated ECM fungi did not provide additional support during drought stress. The activity of secreted extracellular enzymes was higher in S. granulatus than in any other species. In conclusion, our findings suggest that ECM fungal species composition may affect seedling performance in terms of aboveground biomass. PMID:22496914

Growth response of drought-stressed Pinus sylvestris seedlings to single- and multi-species inoculation with ectomycorrhizal fungi.

PubMed

Kipfer, Tabea; Wohlgemuth, Thomas; van der Heijden, Marcel G A; Ghazoul, Jaboury; Egli, Simon

2012-01-01

Many trees species form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve nutrient and water acquisition of their host. Until now it is unclear whether the species richness of ECM fungi is beneficial for tree seedling performance, be it during moist conditions or drought. We performed a pot experiment using Pinus sylvestris seedlings inoculated with four selected ECM fungi (Cenococcum geophilum, Paxillus involutus, Rhizopogon roseolus and Suillus granulatus) to investigate (i) whether these four ECM fungi, in monoculture or in species mixtures, affect growth of P. sylvestris seedlings, and (ii) whether this effect can be attributed to species number per se or to species identity. Two different watering regimes (moist vs. dry) were applied to examine the context-dependency of the results. Additionally, we assessed the activity of eight extracellular enzymes in the root tips. Shoot growth was enhanced in the presence of S. granulatus, but not by any other ECM fungal species. The positive effect of S. granulatus on shoot growth was more pronounced under moist (threefold increase) than under dry conditions (twofold increase), indicating that the investigated ECM fungi did not provide additional support during drought stress. The activity of secreted extracellular enzymes was higher in S. granulatus than in any other species. In conclusion, our findings suggest that ECM fungal species composition may affect seedling performance in terms of aboveground biomass.

Effect of laser energy, substrate film thickness and bioink viscosity on viability of endothelial cells printed by Laser-Assisted Bioprinting

NASA Astrophysics Data System (ADS)

Catros, Sylvain; Guillotin, Bertrand; Bačáková, Markéta; Fricain, Jean-Christophe; Guillemot, Fabien

2011-04-01

Biofabrication of three dimensional tissues by Laser-Assisted Bioprinting (LAB) implies to develop specific strategies for assembling the extracellular matrix (ECM) and cells. Possible strategies consist in (i) printing cells onto or in the depth of ECM layer and/or (ii) printing bioinks containing both cells and ECM-like printable biomaterial. The aim of this article was to evaluate combinatorial effects of laser pulse energy, ECM thickness and viscosity of the bioink on cell viability. A LAB workstation was used to print Ea.hy926 endothelial cells onto a quartz substrate covered with a film of ECM mimicking Matrigel™. Hence, effect of laser energy, Matrigel™ film thickness and bioink viscosity was addressed for different experimental conditions (8-24 μJ, 20-100 μm and 40-110 mPa s, respectively). Cell viability was assessed by live/dead assay performed 24 h post-printing. Results show that increasing the laser energy tends to augment the cell mortality while increasing the thickness of the Matrigel™ film and the viscosity of the bioink support cell viability. Hence, critical printing parameters influencing high cell viability have been related to the cell landing conditions and more specifically to the intensity of the cell impacts occurring at the air-ECM interface and at the ECM-glass interface.

Microemulsion-based synergistic dual-drug codelivery system for enhanced apoptosis of tumor cells.

PubMed

Qu, Ding; Ma, Yihua; Sun, Wenjie; Chen, Yan; Zhou, Jing; Liu, Congyan; Huang, Mengmeng

2015-01-01

A microemulsion-based synergistic dual-drug codelivery system was developed for enhanced cell apoptosis by transporting coix seed oil and etoposide into A549 (human lung carcinoma) cells simultaneously. Results obtained by dynamic light scattering showed that an etoposide (VP16)-loaded coix seed oil microemulsion (EC-ME) delivery system had a small size around 35 nm, a narrow polydispersity index, and a slightly negative surface charge. The encapsulating efficiency and total drug loading rate were 97.01% and 45.48%, respectively, by high-performance liquid chromatography. The release profiles at various pH values showed an obvious pH-responsive difference, with the accumulated amount of VP16 released at pH 4.5 (and pH 5.5) being 2.7-fold higher relative to that at pH 7.4. Morphologic alteration (particle swelling) associated with a mildly acidic pH environment was found on transmission electron microscopy. In the cell study, the EC-ME system showed a significantly greater antiproliferative effect toward A549 cells in comparison with free VP16 and the mixture of VP16 and coix seed oil. The half-maximal inhibitory concentration of the EC-ME system was 3.9-fold and 10.4-fold lower relative to that of free VP16 and a mixture of VP16 and coix seed oil, respectively. Moreover, fluorescein isothiocyanate and VP16 (the green fluorescent probe and entrapped drug, respectively) were efficiently internalized into the cells by means of coix seed oil microemulsion through intuitive observation and quantitative measurement. Importantly, an EC-ME system containing 20 μg/mL of VP16 showed a 3.3-fold and 3.5-fold improvement in induction of cell apoptosis compared with the VP-16-loaded microemulsion and free VP16, respectively. The EC-ME combination strategy holds promise as an efficient drug delivery system for induction of apoptosis and treatment of lung cancer.

Changes in muscle fiber contractility and extracellular matrix production during skeletal muscle hypertrophy.

PubMed

Mendias, Christopher L; Schwartz, Andrew J; Grekin, Jeremy A; Gumucio, Jonathan P; Sugg, Kristoffer B

2017-03-01

Skeletal muscle can adapt to increased mechanical loads by undergoing hypertrophy. Transient reductions in whole muscle force production have been reported during the onset of hypertrophy, but contractile changes in individual muscle fibers have not been previously studied. Additionally, the extracellular matrix (ECM) stores and transmits forces from muscle fibers to tendons and bones, and determining how the ECM changes during hypertrophy is important in understanding the adaptation of muscle tissue to mechanical loading. Using the synergist ablation model, we sought to measure changes in muscle fiber contractility, collagen content, and cross-linking, and in the expression of several genes and activation of signaling proteins that regulate critical components of myogenesis and ECM synthesis and remodeling during muscle hypertrophy. Tissues were harvested 3, 7, and 28 days after induction of hypertrophy, and nonoverloaded rats served as controls. Muscle fiber specific force (sF o ), which is the maximum isometric force normalized to cross-sectional area, was reduced 3 and 7 days after the onset of mechanical overload, but returned to control levels by 28 days. Collagen abundance displayed a similar pattern of change. Nearly a quarter of the transcriptome changed over the course of overload, as well as the activation of signaling pathways related to hypertrophy and atrophy. Overall, this study provides insight into fundamental mechanisms of muscle and ECM growth, and indicates that although muscle fibers appear to have completed remodeling and regeneration 1 mo after synergist ablation, the ECM continues to be actively remodeling at this time point. NEW & NOTEWORTHY This study utilized a rat synergist ablation model to integrate changes in single muscle fiber contractility, extracellular matrix composition, activation of important signaling pathways in muscle adaption, and corresponding changes in the muscle transcriptome to provide novel insight into the basic biological mechanisms of muscle fiber hypertrophy. Copyright © 2017 the American Physiological Society.

Changes in muscle fiber contractility and extracellular matrix production during skeletal muscle hypertrophy

PubMed Central

Schwartz, Andrew J.; Grekin, Jeremy A.; Gumucio, Jonathan P.; Sugg, Kristoffer B.

2017-01-01

Skeletal muscle can adapt to increased mechanical loads by undergoing hypertrophy. Transient reductions in whole muscle force production have been reported during the onset of hypertrophy, but contractile changes in individual muscle fibers have not been previously studied. Additionally, the extracellular matrix (ECM) stores and transmits forces from muscle fibers to tendons and bones, and determining how the ECM changes during hypertrophy is important in understanding the adaptation of muscle tissue to mechanical loading. Using the synergist ablation model, we sought to measure changes in muscle fiber contractility, collagen content, and cross-linking, and in the expression of several genes and activation of signaling proteins that regulate critical components of myogenesis and ECM synthesis and remodeling during muscle hypertrophy. Tissues were harvested 3, 7, and 28 days after induction of hypertrophy, and nonoverloaded rats served as controls. Muscle fiber specific force (sFo), which is the maximum isometric force normalized to cross-sectional area, was reduced 3 and 7 days after the onset of mechanical overload, but returned to control levels by 28 days. Collagen abundance displayed a similar pattern of change. Nearly a quarter of the transcriptome changed over the course of overload, as well as the activation of signaling pathways related to hypertrophy and atrophy. Overall, this study provides insight into fundamental mechanisms of muscle and ECM growth, and indicates that although muscle fibers appear to have completed remodeling and regeneration 1 mo after synergist ablation, the ECM continues to be actively remodeling at this time point. NEW & NOTEWORTHY This study utilized a rat synergist ablation model to integrate changes in single muscle fiber contractility, extracellular matrix composition, activation of important signaling pathways in muscle adaption, and corresponding changes in the muscle transcriptome to provide novel insight into the basic biological mechanisms of muscle fiber hypertrophy. PMID:27979985

75 FR 75665 - Agency Information Collection Activities Under OMB Review: Notice of Intent To Renew Collection...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

... Commodity Exchange Act (Act) provides that exempt commercial markets (ECMs) are markets excluded from the...) implements the notification requirements, and rule 36.3(b)(1) establishes information requirements for ECMs consistent with section 2(h)(5)(B) of the Act. An ECM may provide the Commission with access to transactions...

75 FR 23679 - Order Finding That the ICE Malin Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act...\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs...

75 FR 24586 - Order Finding That the San Juan Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act''), performs a...\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs...

76 FR 4991 - Petition for Exemption From the Vehicle Theft Prevention Standard; Suzuki

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-27

... include an electronically coded key fob, Body Control Module (BCM), Engine Control Module (ECM) and a... results are identical, the BCM will send data to the ECM allowing the vehicle to start. If either the key..., Suzuki stated that the ECM will prohibit operation of the vehicle. In addressing the specific content...

78 FR 3081 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; Toyota

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-15

... receiver, electrical key and an electronic control module (ECM). The conventional key components consist of a transponder key ECU assembly, transponder key coil, security indicator, ignition key and an ECM... certification ECU and steering lock ECU receive confirmation of the valid key, allowing the ECM to start the...

77 FR 28819 - Second Amendment to July 14, 2011 Order for Swap Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

... described herein; and (4) removing any reference to the exempt commercial market (``ECM'') and exempt board... scope of transactions eligible to be transacted on either an ECM or EBOT to include transactions in... transactions) that: (1) Are executed on an ECM or EBOT that is operating under the terms of the Commission's...

76 FR 42508 - Effective Date for Swap Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... trading facility (called exempt commercial markets, or ``ECMs''); \\32\\ 7 U.S.C. 2(h)(3)-(7). \\33\\ The term... 723(c) and 734(c) of the Dodd-Frank Act, to ECMs and EBOTs provided that certain conditions are met... available to an electronic trading facility that, as of July 15, 2011, is not already operating as an ECM...

75 FR 23686 - Order Finding That the Carbon Financial Instrument Contract Offered for Trading on the Chicago...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... commercial market (``ECM'') under Section 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act... (``Reauthorization Act'') \\2\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

Development of a Function-Blocking Antibody Against Fibulin-3 as a Targeted Reagent for Glioblastoma.

PubMed

Nandhu, Mohan S; Behera, Prajna; Bhaskaran, Vivek; Longo, Sharon L; Barrera-Arenas, Lina M; Sengupta, Sadhak; Rodriguez-Gil, Diego J; Chiocca, E Antonio; Viapiano, Mariano S

2018-02-15

Purpose: We sought a novel approach against glioblastomas (GBM) focused on targeting signaling molecules localized in the tumor extracellular matrix (ECM). We investigated fibulin-3, a glycoprotein that forms the ECM scaffold of GBMs and promotes tumor progression by driving Notch and NFκB signaling. Experimental Design: We used deletion constructs to identify a key signaling motif of fibulin-3. An mAb (mAb428.2) was generated against this epitope and extensively validated for specific detection of human fibulin-3. mAb428.2 was tested in cultures to measure its inhibitory effect on fibulin-3 signaling. Nude mice carrying subcutaneous and intracranial GBM xenografts were treated with the maximum achievable dose of mAb428.2 to measure target engagement and antitumor efficacy. Results: We identified a critical 23-amino acid sequence of fibulin-3 that activates its signaling mechanisms. mAb428.2 binds to that epitope with nanomolar affinity and blocks the ability of fibulin-3 to activate ADAM17, Notch, and NFκB signaling in GBM cells. mAb428.2 treatment of subcutaneous GBM xenografts inhibited fibulin-3, increased tumor cell apoptosis, and enhanced the infiltration of inflammatory macrophages. The antibody reduced tumor growth and extended survival of mice carrying GBMs as well as other fibulin-3-expressing tumors. Locally infused mAb428.2 showed efficacy against intracranial GBMs, increasing tumor apoptosis and reducing tumor invasion and vascularization, which are enhanced by fibulin-3. Conclusions: To our knowledge, this is the first rationally developed, function-blocking antibody against an ECM target in GBM. Our results offer a proof of principle for using "anti-ECM" strategies toward more efficient targeted therapies for malignant glioma. Clin Cancer Res; 24(4); 821-33. ©2017 AACR . ©2017 American Association for Cancer Research.

Biological functionality and mechanistic contribution of extracellular matrix-ornamented three dimensional Ti-6Al-4V mesh scaffolds.

PubMed

Kumar, A; Nune, K C; Misra, R D K

2016-11-01

The 3D printed metallic implants are considered bioinert in nature because of the absence of bioactive molecules. Thus, surface modification of bioinert materials is expected to favorably promote osteoblast functions and differentiation. In this context, the objective of this study is to fundamentally elucidate the effect of cell-derived decellularized extracellular matrix (dECM) ornamented 3D printed Ti-6Al-4V scaffolds on biological functions, involving cell adhesion, proliferation, and synthesis of vinculin and actin proteins. To mimic the natural ECM environment, the mineralized ECM of osteoblasts was deposited on the Ti-6Al-4V porous scaffolds, fabricated by electron beam melting (EBM) method. The process comprised of osteoblast proliferation, differentiation, and freeze-thaw cycles to obtain decellularized extra cellular matrix (dECM), in vitro. The dECM provided a natural environment to restore the natural cell functionality of osteoblasts that were cultured on dECM ornamented Ti-6Al-4V scaffolds. In comparison to the bare Ti-6Al-4V scaffolds, a higher cell functionality such as cell adhesion, proliferation, and growth including cell-cell and cell-material interaction were observed on dECM ornamented Ti-6Al-4V scaffolds, which were characterized by using markers for focal adhesion and cytoskeleton such as vinculin and actin. Moreover, electron microscopy also indicated higher cell-material interaction and enhanced proliferation of cells on dECM ornamented Ti-6Al-4V scaffolds, supported by MTT assay. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2751-2763, 2016. © 2016 Wiley Periodicals, Inc.

Endothelin-1 Treatment Induces an Experimental Cerebral Malaria-Like Syndrome in C57BL/6 Mice Infected with Plasmodium berghei NK65.

PubMed

Martins, Yuri C; Freeman, Brandi D; Akide Ndunge, Oscar B; Weiss, Louis M; Tanowitz, Herbert B; Desruisseaux, Mahalia S

2016-11-01

Plasmodium berghei ANKA infection of C57BL/6 mice is a widely used model of experimental cerebral malaria (ECM). By contrast, the nonneurotropic P. berghei NK65 (PbN) causes severe malarial disease in C57BL/6 mice but does not cause ECM. Previous studies suggest that endothelin-1 (ET-1) contributes to the pathogenesis of ECM. In this study, we characterize the role of ET-1 on ECM vascular dysfunction. Mice infected with 10 6 PbN-parasitized red blood cells were treated with either ET-1 or saline from 2 to 8 days postinfection (dpi). Plasmodium berghei ANKA-infected mice served as the positive control. ET-1-treated PbN-infected mice exhibited neurological signs, hypothermia, and behavioral alterations characteristic of ECM, dying 4 to 8 dpi. Parasitemia was not affected by ET-1 treatment. Saline-treated PbN-infected mice did not display ECM, surviving until 12 dpi. ET-1-treated PbN-infected mice displayed leukocyte adhesion to the vascular endothelia and petechial hemorrhages throughout the brain at 6 dpi. Intravital microscopic images demonstrated significant brain arteriolar vessel constriction, decreased functional capillary density, and increased blood-brain barrier permeability. These alterations were not present in either ET-1-treated uninfected or saline-treated PbN-infected mice. In summary, ET-1 treatment of PbN-infected mice induced an ECM-like syndrome, causing brain vasoconstriction, adherence of activated leukocytes in the cerebral microvasculature, and blood-brain barrier leakage, indicating that ET-1 is involved in the genesis of brain microvascular alterations that are the hallmark of ECM. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I.

PubMed

Paduano, Francesco; Marrelli, Massimo; White, Lisa J; Shakesheff, Kevin M; Tatullo, Marco

2016-01-01

The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs) on hydrogel scaffolds derived from bone extracellular matrix (bECM) in comparison to those seeded on collagen I (Col-I), one of the main components of dental pulp ECM. DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF) supplements. DPSCs cultivated on tissue culture polystyrene (TCPS) with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE) was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and mineral deposition was observed by Von Kossa staining. When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions. These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs.

High resolution three-dimensional reconstruction of fibrotic skeletal muscle extracellular matrix.

PubMed

Gillies, Allison R; Chapman, Mark A; Bushong, Eric A; Deerinck, Thomas J; Ellisman, Mark H; Lieber, Richard L

2017-02-15

Fibrosis occurs secondary to many skeletal muscle diseases and injuries, and can alter muscle function. It is unknown how collagen, the most abundant extracellular structural protein, alters its organization during fibrosis. Quantitative and qualitative high-magnification electron microscopy shows that collagen is organized into perimysial cables which increase in number in a model of fibrosis, and cables have unique interactions with collagen-producing cells. Fibrotic muscles are stiffer and have a higher concentration of collagen-producing cells. These results improve our understanding of the organization of fibrotic skeletal muscle extracellular matrix and identify novel structures that might be targeted by antifibrotic therapy. Skeletal muscle extracellular matrix (ECM) structure and organization are not well understood, yet the ECM plays an important role in normal tissue homeostasis and disease processes. Fibrosis is common to many muscle diseases and is typically quantified based on an increase in ECM collagen. Through the use of multiple imaging modalities and quantitative stereology, we describe the structure and composition of wild-type and fibrotic ECM, we show that collagen in the ECM is organized into large bundles of fibrils, or collagen cables, and the number of these cables (but not their size) increases in desmin knockout muscle (a fibrosis model). The increase in cable number is accompanied by increased muscle stiffness and an increase in the number of collagen producing cells. Unique interactions between ECM cells and collagen cables were also observed and reconstructed by serial block face scanning electron microscopy. These results demonstrate that the muscle ECM is more highly organized than previously reported. Therapeutic strategies for skeletal muscle fibrosis should consider the organization of the ECM to target the structures and cells contributing to fibrotic muscle function. © 2016 Rehabilitation Institute of Chicago. The Journal of Physiology © 2016 The Physiological Society.

Endothelin-1 mediated induction of extracellular matrix genes in strial marginal cells underlies strial pathology in Alport mice.

PubMed

Meehan, Daniel T; Delimont, Duane; Dufek, Brianna; Zallocchi, Marisa; Phillips, Grady; Gratton, Michael Anne; Cosgrove, Dominic

2016-11-01

Alport syndrome, a type IV collagen disorder, manifests as glomerular disease associated with hearing loss with thickening of the glomerular and strial capillary basement membranes (SCBMs). We have identified a role for endothelin-1 (ET-1) activation of endothelin A receptors (ET A Rs) in glomerular pathogenesis. Here we explore whether ET-1 plays a role in strial pathology. Wild type (WT) and Alport mice were treated with the ET A R antagonist, sitaxentan. The stria vascularis was analyzed for SCBM thickness and for extracellular matrix (ECM) proteins. Additional WT and Alport mice were exposed to noise or hypoxia and the stria analyzed for hypoxia-related and ECM genes. A strial marginal cell line cultured under hypoxic conditions, or stimulated with ET-1 was analyzed for expression of hypoxia-related and ECM transcripts. Noise exposure resulted in significantly elevated ABR thresholds in Alport mice relative to wild type littermates. Alport stria showed elevated expression of collagen α1(IV), laminin α2, and laminin α5 proteins relative to WT. SCBM thickening and elevated ECM protein expression was ameliorated by ET A R blockade. Stria from normoxic Alport mice and hypoxic WT mice showed upregulation of hypoxia-related, ECM, and ET-1 transcripts. Both ET-1 stimulation and hypoxia up-regulated ECM transcripts in cultured marginal cells. We conclude that ET-1 mediated activation of ET A Rs on strial marginal cells results in elevated expression of ECM genes and thickening of the SCBMs in Alport mice. SCBM thickening results in hypoxic stress further elevating ECM and ET-1 gene expression, exacerbating strial pathology. Copyright © 2016 Elsevier B.V. All rights reserved.

High resolution three‐dimensional reconstruction of fibrotic skeletal muscle extracellular matrix

PubMed Central

Gillies, Allison R.; Chapman, Mark A.; Bushong, Eric A.; Deerinck, Thomas J.; Ellisman, Mark H.

2016-01-01

Key points Fibrosis occurs secondary to many skeletal muscle diseases and injuries, and can alter muscle function.It is unknown how collagen, the most abundant extracellular structural protein, alters its organization during fibrosis.Quantitative and qualitative high‐magnification electron microscopy shows that collagen is organized into perimysial cables which increase in number in a model of fibrosis, and cables have unique interactions with collagen‐producing cells.Fibrotic muscles are stiffer and have a higher concentration of collagen‐producing cells.These results improve our understanding of the organization of fibrotic skeletal muscle extracellular matrix and identify novel structures that might be targeted by antifibrotic therapy. Abstract Skeletal muscle extracellular matrix (ECM) structure and organization are not well understood, yet the ECM plays an important role in normal tissue homeostasis and disease processes. Fibrosis is common to many muscle diseases and is typically quantified based on an increase in ECM collagen. Through the use of multiple imaging modalities and quantitative stereology, we describe the structure and composition of wild‐type and fibrotic ECM, we show that collagen in the ECM is organized into large bundles of fibrils, or collagen cables, and the number of these cables (but not their size) increases in desmin knockout muscle (a fibrosis model). The increase in cable number is accompanied by increased muscle stiffness and an increase in the number of collagen producing cells. Unique interactions between ECM cells and collagen cables were also observed and reconstructed by serial block face scanning electron microscopy. These results demonstrate that the muscle ECM is more highly organized than previously reported. Therapeutic strategies for skeletal muscle fibrosis should consider the organization of the ECM to target the structures and cells contributing to fibrotic muscle function. PMID:27859324

Edaphic factors do not govern the ectomycorrhizal specificity of Pisonia grandis (Nyctaginaceae).

PubMed

Hayward, Jeremy A; Horton, Thomas R

2012-11-01

Pisonia grandis (Nyctaginaceae), a widespread tree of Pacific coral atolls and islands, displays one of the more restrictive ranges of ectomycorrhizal (ECM) fungus associates among autotrophic plants. Only five ECM fungi are currently known associates; our study adds one. In many habitats, P. grandis is restricted to large seabird colonies where nitrogen and phosphorus inputs in the form of guano are substantial. It has been suggested that the ECM specificity displayed by P. grandis is the result of the unusual nutrient-rich habitat in which P. grandis grows. On Rota, Commonwealth of the Northern Mariana Islands, P. grandis grows in habitats heavily influenced by guano additions and also in upland forests where seabirds do not roost or nest. To test the hypothesis that the ECM specificity displayed by P. grandis is the result of nutrient-related or toxicity-related factors associated with guano inputs, we sampled P. grandis growing in both guano-rich and guano-poor habitats on Rota, Commonwealth of the Northern Mariana Islands. We identified ECM symbionts of P. grandis from both habitats as well as two symbionts of Intsia bijuga (Fabaceae) from nutrient-rich habitats. We identified three ECM symbionts of P. grandis from Rota; all three were found in both guano-rich and guano-poor habitats. No differences in community diversity were detected between guano-rich and guano-poor habitats. We also detected two ECM fungal species associating with I. bijuga but not associating with P. grandis inside guano-rich habitats. From these results, we infer that edaphic factors are not responsible for limiting the ECM community associating with P. grandis to its observed level of specificity.

Syndecan-2 is upregulated in colorectal cancer cells through interactions with extracellular matrix produced by stromal fibroblasts.

PubMed

Vicente, Carolina Meloni; Ricci, Ritchelli; Nader, Helena Bonciani; Toma, Leny

2013-05-25

The extracellular matrix (ECM) influences the structure, viability and functions of cells and tissues. Recent evidence indicates that tumor cells and stromal cells interact through direct cell-cell contact, the production of ECM components and the secretion of growth factors. Syndecans are a family of transmembrane heparan sulfate proteoglycans that are involved in cell adhesion, motility, proliferation and differentiation. Syndecan-2 has been found to be highly expressed in colorectal cancer cell lines and appears to be critical for cancer cell behavior. We have examined the effect of stromal fibroblast-produced ECM on the production of proteoglycans by colorectal cancer cell lines. Our results showed that in a highly metastatic colorectal cancer cell line, HCT-116, syndecan-2 expression is enhanced by fibroblast ECM, while the expression of other syndecans decreased. Of the various components of the stromal ECM, fibronectin was the most important in stimulating the increase in syndecan-2 expression. The co-localization of syndecan-2 and fibronectin suggests that these two molecules are involved in the adhesion of HCT-116 cells to the ECM. Additionally, we demonstrated an increase in the expression of integrins alpha-2 and beta-1, in addition to an increase in the expression of phospho-FAK in the presence of fibroblast ECM. Furthermore, blocking syndecan-2 with a specific antibody resulted in a decrease in cell adhesion, migration, and organization of actin filaments. Overall, these results show that interactions between cancer cells and stromal ECM proteins induce significant changes in the behavior of cancer cells. In particular, a shift from the expression of anti-tumorigenic syndecans to the tumorigenic syndecan-2 may have implications in the migratory behavior of highly metastatic tumor cells.

Role of extracellular matrix in regulation of staurosporine-induced apoptosis in breast cancer cells.

PubMed

Vasaturo, F; Malacrino, C; Sallusti, E; Coppotelli, G; Birarelli, P; Giuffrida, A; Albonici, L; Simonelli, L; Modesti, A; Modesti, M; Scarpa, S

2005-04-01

Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.

Ornamenting 3D printed scaffolds with cell-laid extracellular matrix for bone tissue regeneration.

PubMed

Pati, Falguni; Song, Tae-Ha; Rijal, Girdhari; Jang, Jinah; Kim, Sung Won; Cho, Dong-Woo

2015-01-01

3D printing technique is the most sophisticated technique to produce scaffolds with tailorable physical properties. But, these scaffolds often suffer from limited biological functionality as they are typically made from synthetic materials. Cell-laid mineralized ECM was shown to be potential for improving the cellular responses and drive osteogenesis of stem cells. Here, we intend to improve the biological functionality of 3D-printed synthetic scaffolds by ornamenting them with cell-laid mineralized extracellular matrix (ECM) that mimics a bony microenvironment. We developed bone graft substitutes by using 3D printed scaffolds made from a composite of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) and mineralized ECM laid by human nasal inferior turbinate tissue-derived mesenchymal stromal cells (hTMSCs). A rotary flask bioreactor was used to culture hTMSCs on the scaffolds to foster formation of mineralized ECM. A freeze/thaw cycle in hypotonic buffer was used to efficiently decellularize (97% DNA reduction) the ECM-ornamented scaffolds while preserving its main organic and inorganic components. The ECM-ornamented 3D printed scaffolds supported osteoblastic differentiation of newly-seeded hTMSCs by upregulating four typical osteoblastic genes (4-fold higher RUNX2; 3-fold higher ALP; 4-fold higher osteocalcin; and 4-fold higher osteopontin) and increasing calcium deposition compared to bare 3D printed scaffolds. In vivo, in ectopic and orthotopic models in rats, ECM-ornamented scaffolds induced greater bone formation than that of bare scaffolds. These results suggest a valuable method to produce ECM-ornamented 3D printed scaffolds as off-the-shelf bone graft substitutes that combine tunable physical properties with physiological presentation of biological signals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of simulated nitrogen deposition on ectomycorrhizae community structure in hybrid larch and its parents grown in volcanic ash soil: The role of phosphorous.

PubMed

Wang, Xiaona; Agathokleous, Evgenios; Qu, Laiye; Fujita, Saki; Watanabe, Makoto; Tamai, Yutaka; Mao, Qiaozhi; Koyama, Akihiro; Koike, Takayoshi

2018-03-15

With the rapid industrial development and modern agricultural practices, increasing nitrogen (N) deposition can cause nutrient imbalance in immature volcanic ash soil commonly found in Japan. Larch species, widely distributed in northeast Eurasia, are associated with ectomycorrhizal (ECM) fungi which play a critical role in nutrient acquisition for their hosts. In this study, we investigated species richness and diversity of ECM fungi associated with a hybrid larch (F 1 ) and its parents, Dahurian larch (Larix gmelinii var. japonica) and Japanese larch (L. kaempferi), under simulated N deposition (0 and 100kgha -1 yr -1 ) with/without phosphorous (P) (0 and 50kgha -1 yr -1 ). Seedlings planted in immature volcanic ash with low nutrient availability were subjected to the N and P treatments for fifteen months. We found that response of ECM community structure to the increased nutrient availability depended on host genotypes. Nutrient addition significantly affected ECM structure in Japanese larch, but no such significant effect was found for Dahurian larch. Effects of the nutrient addition to ECM fungal community in F 1 were intermediate. F 1 was tolerant to high N loading, which was due to consistent, relatively high association with Suillus sp. and Hebeloma sp. F 1 showed heterosis in relative biomass, which was most apparent under high N treatments. This co-variation of ECM fungal community structure and F 1 biomass in response to N loading suggest that ECM community structure might play an important role in host growth. The present findings indicate effects of N deposition on ECM fungal community structure can depend on larch species, thus it is challenging to predict general trends. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Spencer, Virginia A.; Xu, Ren; Bissell, Mina J.

Almost three decades ago, we presented a model where theextracellular matrix (ECM) was postulated to influence gene expressionand tissue-specificity through the action of ECM receptors and thecytoskeleton. This hypothesis implied that ECM molecules could signal tothe nucleus and that the unit of function in higher organisms was not thecell alone, but the cell plus its microenvironment. We now know that ECMinvokes changes in tissue and organ architecture and that tissue, cell,nuclear, and chromatin structure are changed profoundly as a result ofand during malignant progression. Whereas some evidence has beengenerated for a link between ECM-induced alterations in tissuearchitecture and changes inmore » both nuclear and chromatin organization, themanner by which these changes actively induce or repress gene expressionin normal and malignant cells is a topic in need of further attention.Here, we will discuss some key findings that may provide insights intomechanisms through which ECM could influence gene transcription and howtumor cells acquire the ability to overcome these levels ofcontrol.« less

Why regenerative medicine needs an extracellular matrix.

PubMed

Prestwich, Glenn D; Healy, Kevin E

2015-01-01

Regenerative medicine is now coming of age. Many attempts at cell therapy have failed to show significant efficacy, and the umbrella term 'stem cell therapy' is perceived in some quarters as hype or just expensive and unnecessary medical tourism. Here we present a short editorial in three parts. First, we examine the importance of using a semisynthetic extracellular matrix (ECM) mimetic, or sECM, to deliver and retain therapeutic cells at the site of administration. Second, we describe one approach in which biophysical and biochemical properties are tailored to each tissue type, which we call "design for optimal functionality." Third, we describe an alternative approach to sECM design and implementation, called "design for simplicity," in which a deconstructed, minimalist sECM is employed and biology is allowed to perform the customization in situ. We opine that an sECM, whether minimal or instructive, is an essential contributor to improve the outcomes of cell-based therapies.

Dynamic expression patterns of ECM molecules in the developing mouse olfactory pathway

PubMed Central

Shay, Elaine L.; Greer, Charles A.; Treloar, Helen B.

2009-01-01

Olfactory sensory neuron (OSN) axons follow stereotypic spatio-temporal paths in the establishment of the olfactory pathway. Extracellular matrix (ECM) molecules are expressed early in the developing pathway and are proposed to have a role in its initial establishment. During later embryonic development, OSNs sort out and target specific glomeruli to form precise, complex topographic projections. We hypothesized that ECM cues may help to establish this complex topography. The aim of this study was to characterize expression of ECM molecules during the period of glomerulogenesis, when synaptic contacts are forming. We examined expression of laminin-1, perlecan, tenascin-C and CSPGs and found a coordinated pattern of expression of these cues in the pathway. These appear to restrict axons to the pathway while promoting axon outgrowth within. Thus, ECM molecules are present in dynamic spatio-temporal positions to affect OSN axons as they navigate to the olfactory bulb and establish synapses. PMID:18570250

Matrix metalloproteinases in liver injury, repair and fibrosis

PubMed Central

Duarte, Sergio; Baber, John; Fujii, Takehiro; Coito, Ana J.

2015-01-01

The liver is a large highly vascularized organ with a central function in metabolic homeostasis, detoxification, and immunity. Due to its roles, the liver is frequently exposed to various insults which can cause cell death and hepatic dysfunction. Alternatively, the liver has a remarkable ability to self-repair and regenerate after injury. Liver injury and regeneration have both been linked to complex extracellular matrix (ECM) related pathways. While normal degradation of ECM components is an important feature of tissue repair and remodeling, irregular ECM turnover contributes to a variety of liver diseases. Matrix metalloproteinases (MMPs) are the main enzymes implicated in ECM degradation. MMPs not only remodel the ECM, but also regulate immune responses. In this review, we highlight some of the MMP-attributed roles in acute and chronic liver injury and emphasize the need for further experimentation to better understand their functions during hepatic physiological conditions and disease progression. PMID:25599939

Role of YAP/TAZ in cell-matrix adhesion-mediated signalling and mechanotransduction

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

Dupont, Sirio, E-mail: sirio.dupont@unipd.it

2016-04-10

Signalling from the extracellular matrix (ECM) is a fundamental cellular input that sustains proliferation, opposes cell death and regulates differentiation. Through integrins, cells perceive both the chemical composition and physical properties of the ECM. In particular, cell behaviour is profoundly influenced by the mechanical elasticity or stiffness of the ECM, which regulates the ability of cells to develop forces through their contractile actomyosin cytoskeleton and to mature focal adhesions. This mechanosensing ability affects fundamental cellular functions, such that alterations of ECM stiffness is nowadays considered not a simple consequence of pathology, but a causative input driving aberrant cell behaviours. Wemore » here discuss recent advances on how mechanical signals intersect nuclear transcription and in particular the activity of YAP/TAZ transcriptional coactivators, known downstream transducers of the Hippo pathway and important effectors of ECM mechanical cues.« less

Atomic Scale Medium Range Order and Relaxation Dynamics in Metallic Glass

NASA Astrophysics Data System (ADS)

Zhang, Pei

We studied the atomic scale structure of bulk metallic glass (BMG) with the combination of fluctuation electron microscopy (FEM) and hybrid reverse Monte Carlo (HRMC) simulation. Medium range order (MRO), which occupies the length scale between short range order (SRO) and long-range order, plays an important role on the properties of metallic glass, but the characterization of MRO in experiment is difficult because conventional techniques are not sensitive to the structure at MRO scale. Compared with the X-ray and neutron which can measure SRO by two-body correlation functions, FEM is an effective way to detect MRO structure through three and four-body correlation functions, providing information about the size, distribution, and internal structure of MRO combing HRMC modeling. Thickness estimation is necessary in FEM experiment and HRMC calculation, so in Chapter 3, we measured the elastic and inelastic mean free paths of metallic glass alloys based on focused ion beam prepared thin samples with measured thickness gradients. We developed a model based on the Wentzel atomic model to predict the elastic mean free path for other amorphous materials. In Chapter 4, we studied the correlation of MRO and glass forming ability ZrCuAl alloy. Results from Variable resolution fluctuation microscopy show that in Zr50Cu35Al15 the crystal-like clusters shrink but become more ordered, while icosahedral-like clusters grow. Compared with Zr50Cu45Al5, Zr50Cu35Al15 with poorer glass forming ability exhibits more stable crystal-like structure under annealing, indicating that destabilizing crystal-like structures is important to achieve better glass forming ability in this alloy. In Chapter 5, we studied the crystallization and MRO structural in deformed and quenched Ni60Nb40 metallic glass. The deformed Ni60Nb40 contains fewer icosahedral-like Voronoi clusters and more crystal-like and bcc-like Voronoi clusters. The crystal-like and bcc-like medium range order clusters may be the structural origin for its lower crystallization temperature compared with quenched alloy. Dynamics heterogeneity is proposed to be the microscopic origin of the dynamic nature of glass transition. Some experimental evidence and simulation have indicated that different regions of materials indeed relax at fast or slow rate. However, the spatial distribution of relaxation time visualized from the experiment as the direct evidence of heterogeneous dynamics is still challenging. We proposed to measure the structural dynamics of supercooled metallic glasses with electron correlation microscopy (ECM) technique at the nanometer scale. ECM was developed as a way to measure structural relaxation times of liquids with nanometer-scale spatial resolution using the coherent electron scattering equivalent of photon correlation spectroscopy. In chapter 6, we studied the experimental requirements of ECM to obtain reliable results. For example, the trajectory length must be at least 40 times the relaxation time to obtain a well-converged g2( t), and the time per frame must be less than 0.1 time the relaxation time to obtain sufficient sampling. ECM experiment was firstly realized in scanning transmission electron microscopy (STEM) mode and applied to measure the structural relaxation time of Pd based metallic glass. In order to overcome the drift problem and capture the spatial information, we developed ECM experiment in dark field (DF) mode. In Chapter 7, through DF-ECM, we visualized the spatially heterogeneous dynamics by in-situ heating Pt57.5Cu14.7Ni 5.3P22.5 nanowire into supercooled liquid state, and quantify the size of the heterogeneity by four-point correlation function. The thickness effect and temporal evolution of the heterogeneous domain were also discussed. Additionally, a fast near-surface dynamics was discovered, providing an effective mechanism for surface crystallization of liquids by homogeneous nucleation.

75 FR 24626 - Order Finding That the TETCO-M3 Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act''), performs a...\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs...

75 FR 38478 - Orders Finding That the Mid-C Financial Peak Daily Contract and Mid-C Financial Off-Peak Daily...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... exempt commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or... (``Reauthorization Act'') \\4\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

75 FR 24612 - Order Finding That the Zone 6-NY Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act''), performs a... (``Reauthorization Act'') \\2\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

78 FR 28018 - Petition for Exemption From the Vehicle Theft Prevention Standard; Nissan

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-13

... (ECM). Nissan will also install an audible and visible alarm system on the Infiniti QX60 as standard... and transmitted to the BCM. The ECM then requests the BCM to start the encrypted communication. If the encrypted code is correct, the BCM sends an ``OK-code'' and encrypted code to the ECM. If the code is not...

77 FR 4396 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; Toyota

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

..., transmission control ECU, electronic control module (ECM) and security indicator. The Prius v wagon will... located on the instrument panel to start the vehicle. The correct key has to be recognized by the ECM in... receive confirmation of the valid key and allows the ECM to start the engine. On the Prius v model, the...

75 FR 24592 - Order Finding that the TETCO-M3 Financial Basis Contract Traded on the IntercontinentalExchange...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act''), performs a... (``Reauthorization Act'') \\2\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

75 FR 42411 - Orders Finding That the SP-15 Financial Day-Ahead LMP Peak Daily Contract; SP-15 Financial Day...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

...''), an exempt commercial market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA... (``Reauthorization Act'') \\5\\ significantly broadened the CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price...

75 FR 38469 - Orders Finding That the Mid-C Financial Peak Contract and Mid-C Financial Off-Peak Contract...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... market (``ECM'') under sections 2(h)(3)-(5) of the Commodity Exchange Act (``CEA'' or the ``Act... CFTC's regulatory authority with respect to ECMs by creating, in section 2(h)(7) of the CEA, a new regulatory category--ECMs on which significant price discovery contracts (``SPDCs'') are traded--and treating...

75 FR 56512 - Notice Regarding the Treatment of Petitions Seeking Grandfather Relief for Trading Activity Done...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... affected by the Dodd-Frank Act's elimination of the CEA Section 2(h)(3)-(7) exempt commercial market (``ECM... foresaw that many entities that currently operate as ECMs or EBOTs will seek to become either swap... regulatory provisions are not likely to be completed until close to the same time that the ECM and EBOT...

Back to basics--how the evolution of the extracellular matrix underpinned vertebrate evolution.

PubMed

Huxley-Jones, Julie; Pinney, John W; Archer, John; Robertson, David L; Boot-Handford, Raymond P

2009-04-01

The extracellular matrix (ECM) is a complex substrate that is involved in and influences a spectrum of behaviours such as growth and differentiation and is the basis for the structure of tissues. Although a characteristic of all metazoans, the ECM has elaborated into a variety of tissues unique to vertebrates, such as bone, tendon and cartilage. Here we review recent advances in our understanding of the molecular evolution of the ECM. Furthermore, we demonstrate that ECM genes represent a pivotal family of proteins the evolution of which appears to have played an important role in the evolution of vertebrates.

Matrix metalloproteinase-2 plays a critical role in overload induced skeletal muscle hypertrophy.

PubMed

Zhang, Qia; Joshi, Sunil K; Lovett, David H; Zhang, Bryon; Bodine, Sue; Kim, Hubert T; Liu, Xuhui

2014-01-01

extracellular matrix (ECM) components are instrumental in maintaining homeostasis and muscle fiber functional integrity. Skeletal muscle hypertrophy is associated with ECM remodeling. Specifically, recent studies have reported the involvement of matrix metalloproteinases (MMPs) in muscle ECM remodeling. However, the functional role of MMPs in muscle hypertrophy remains largely unknown. in this study, we examined the role of MMP-2 in skeletal muscle hypertrophy using a previously validated method where the plantaris muscle of mice were subjected to mechanical overload due to the surgical removal of synergist muscles (gastrocnemius and soleus). following two weeks of overload, we observed a significant increase in MMP-2 activity and up-regulation of ECM components and remodeling enzymes in the plantaris muscles of wild-type mice. However, MMP-2 knockout mice developed significantly less hypertrophy and ECM remodeling in response to overload compared to their wild-type littermates. Investigation of protein synthesis rate and Akt/mTOR signaling revealed no difference between wild-type and MMP-2 knockout mice, suggesting that a difference in hypertrophy was independent of protein synthesis. taken together, our results suggest that MMP-2 is a key mediator of ECM remodeling in the setting of skeletal muscle hypertrophy.

Matrix metalloproteinase-2 plays a critical role in overload induced skeletal muscle hypertrophy.

PubMed

Zhang, Qia; Joshi, Sunil K; Lovett, David H; Zhang, Bryon; Bodine, Sue; Kim, Hubert; Liu, Xuhui

2014-07-01

extracellular matrix (ECM) components are instrumental in maintaining homeostasis and muscle fiber functional integrity. Skeletal muscle hypertrophy is associated with ECM remodeling. Specifically, recent studies have reported the involvement of matrix metalloproteinases (MMPs) in muscle ECM remodeling. However, the functional role of MMPs in muscle hypertrophy remains largely unknown. in this study, we examined the role of MMP-2 in skeletal muscle hypertrophy using a previously validated method where the plantaris muscle of mice were subjected to mechanical overload due to the surgical removal of synergist muscles (gastrocnemius and soleus). following two weeks of overload, we observed a significant increase in MMP-2 activity and up-regulation of ECM components and remodeling enzymes in the plantaris muscles of wild-type mice. However, MMP-2 knockout mice developed significantly less hypertrophy and ECM remodeling in response to overload compared to their wild-type littermates. Investigation of protein synthesis rate and Akt/mTOR signaling revealed no difference between wild-type and MMP-2 knockout mice, suggesting that a difference in hypertrophy was independent of protein synthesis. taken together, our results suggest that MMP-2 is a key mediator of ECM remodeling in the setting of skeletal muscle hypertrophy.

Effects of warming on ectomycorrhizal colonization and nitrogen nutrition of Picea asperata seedlings grown in two contrasting forest ecosystems

PubMed Central

Li, Yuejiao; Sun, Didi; Li, Dandan; Xu, Zhenfeng; Zhao, Chunzhang; Lin, Honghui; Liu, Qing

2015-01-01

Ectomycorrhiza (ECM) plays an important role in plant nitrogen (N) nutrition and regulates plant responded to climate warming. We conducted a field experiment in a natural forest and a plantation in the eastern Tibetan Plateau to estimate the warming effects of open-top chambers (OTC) on ECM and N nutrition of Picea asperata seedlings. Four-year warming significantly decreased ECM colonization, ECM fungal biomass, fine root vigor, and the N concentration of leaf, stem and coarse root, but significantly increased fine root N concentration and N content of leaf, stem, fine root and whole plant in natural forest. Contrarily, warming induced no obvious change in most of these parameters in plantation. Moreover, warming decreased rhizospheric soil inorganic N content in both forests. Our results showed that four-year warming was not beneficial for ECM colonization of P. asperata seedlings in the two forests, and the seedlings in natural forest were more sensitive and flexible to experimental warming than in plantation. The changes of ECM colonization and fine root biomass for effective N uptake would be good for plant growth and remit N leaching under future warming in natural forest. PMID:26655633

Tricholoma matsutake in a natural Pinus densiflora forest: correspondence between above- and below-ground genets, association with multiple host trees and alteration of existing ectomycorrhizal communities.

PubMed

Lian, Chunlan; Narimatsu, Maki; Nara, Kazuhide; Hogetsu, Taizo

2006-01-01

Tricholoma matsutake (matsutake) is an ectomycorrhizal (ECM) fungus that produces economically important mushrooms in Japan. Here, we use microsatellite markers to identify genets of matsutake sporocarps and below-ground ECM tips, as well as associated host genotypes of Pinus densiflora. We also studied ECM fungal community structure inside, beneath and outside the matsutake fairy rings, using morphological and internal transcribed spacer (ITS) polymorphism analysis. Based on sporocarp samples, one to four genets were found within each fairy ring, and no genetic differentiation among six sites was detected. Matsutake ECM tips were only found beneath fairy rings and corresponded with the genotypes of the above-ground sporocarps. We detected nine below-ground matsutake genets, all of which colonized multiple pine trees (three to seven trees per genet). The ECM fungal community beneath fairy rings was species-poor and significantly differed from those inside and outside the fairy rings. We conclude that matsutake genets occasionally establish from basidiospores and expand on the root systems of multiple host trees. Although matsutake mycelia suppress other ECM fungi during expansion, most of them may recover after the passage of the fairy rings.

Fibrin hydrogels functionalized with cartilage extracellular matrix and incorporating freshly isolated stromal cells as an injectable for cartilage regeneration.

PubMed

Almeida, H V; Eswaramoorthy, R; Cunniffe, G M; Buckley, C T; O'Brien, F J; Kelly, D J

2016-05-01

Freshly isolated stromal cells can potentially be used as an alternative to in vitro expanded cells in regenerative medicine. Their use requires the development of bioactive hydrogels or scaffolds which provide an environment to enhance their proliferation and tissue-specific differentiation in vivo. The goal of the current study was to develop an injectable fibrin hydrogel functionalized with cartilage ECM microparticles and transforming growth factor (TGF)-β3 as a putative therapeutic for articular cartilage regeneration. ECM microparticles were produced by cryomilling and freeze-drying porcine articular cartilage. Up to 2% (w/v) ECM could be incorporated into fibrin without detrimentally affecting its capacity to form stable hydrogels. To access the chondroinductivity of cartilage ECM, we compared chondrogenesis of infrapatellar fat pad-derived stem cells in fibrin hydrogels functionalized with either particulated ECM or control gelatin microspheres. Cartilage ECM particles could be used to control the delivery of TGF-β3 to IFP-derived stem cells within fibrin hydrogels in vitro, and furthermore, led to higher levels of sulphated glycosaminoglycan (sGAG) and collagen accumulation compared to control constructs loaded with gelatin microspheres. In vivo, freshly isolated stromal cells generated a more cartilage-like tissue within fibrin hydrogels functionalized with cartilage ECM particles compared to the control gelatin loaded constructs. These tissues stained strongly for type II collagen and contained higher levels of sGAGs. These results support the use of fibrin hydrogels functionalized with cartilage ECM components in single-stage, cell-based therapies for joint regeneration. An alternative to the use of in vitro expanded cells in regenerative medicine is the use of freshly isolated stromal cells, where a bioactive scaffold or hydrogel is used to provide an environment that enhances their proliferation and tissue-specific differentiation in vivo. The objective of this study was to develop an injectable fibrin hydrogel functionalized with cartilage ECM micro-particles and the growth factor TGF-β3 as a therapeutic for articular cartilage regeneration. This study demonstrates that freshly isolated stromal cells generate cartilage tissue in vivo when incorporated into such a fibrin hydrogels functionalized with cartilage ECM particles. These findings open up new possibilities for in-theatre, single-stage, cell-based therapies for joint regeneration. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Direct studies of low-energy resonances in 31P(p, ) 28Si and 35Cl(p, )32S

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

Moazen, Brian; Matei, Catalin; Bardayan, Daniel W

2011-01-01

Low-energy resonances in 31P(p,a)28Si and 35Cl(p,a)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae, supernovae, and X-ray bursts. Resonance strengths at Ec:m = 600 and 622 keV in 31P(p,a)28Si were measured as well as the Ec:m: = 611 keV resonance in 35Cl(p,a)32S, the lowest energy that any resonance in this reaction has been observed. The strengths of these resonances were found to be lower than previously determined through indirect methods, resulting in weak cycling in the Si-Ar region.

Extracellular matrix composition and rigidity regulate invasive behavior and response to PDT in 3D pancreatic tumor models

NASA Astrophysics Data System (ADS)

Cramer, Gwendolyn; El-Hamidi, Hamid; Jafari, Seyedehrojin; Jones, Dustin P.; Celli, Jonathan P.

2016-03-01

The composition and mechanical compliance of the extracellular matrix (ECM) have been shown to serve as regulators of tumor growth and invasive behavior. These effects may be particularly relevant in tumors of the pancreas, noted for a profound desmoplastic reaction and an abundance of stroma rich in ECM. In view of recent progress in the clinical implementation of photodynamic therapy (PDT) for pancreatic tumors, in this report we examine how ECM composition and rheological properties impact upon invasive behavior and response to PDT in 3D multicellular pancreatic tumor spheroids in ECM environments with characterized rheological properties. Tumor spheroids were cultured initially in attachment-free conditions to form millimeter-sized spheroids that were transplanted into reconstituted ECM microenvironments (Matrigel and Type I Collagen) that were characterized using bulk oscillatory shear rheology. Analysis of growth behavior shows that the soft collagen ECM promoted growth and extensive invasion and this microenvironment was used in subsequent assessment of PDT and chemotherapy response. Evaluation of treatment response revealed that primary tumor nodule growth is inhibited more effectively with PDT, while verteporfin PDT response is significantly enhanced in the ECM-infiltrating populations that are non-responsive to oxaliplatin chemotherapy. This finding is potentially significant, suggesting the potential for PDT to target these clinically problematic invasive populations that are associated with aggressive metastatic progression and chemoresistance. Experiments to further validate and identify the mechanistic basis of this observation are ongoing.

Synovial fibroblasts self-direct multicellular lining architecture and synthetic function in three-dimensional organ culture.

PubMed

Kiener, Hans P; Watts, Gerald F M; Cui, Yajun; Wright, John; Thornhill, Thomas S; Sköld, Markus; Behar, Samuel M; Niederreiter, Birgit; Lu, Jun; Cernadas, Manuela; Coyle, Anthony J; Sims, Gary P; Smolen, Josef; Warman, Matthew L; Brenner, Michael B; Lee, David M

2010-03-01

To define the intrinsic capacity of fibroblast-like synoviocytes (FLS) to establish a 3-dimensional (3-D) complex synovial lining architecture characterized by the multicellular organization of the compacted synovial lining and the elaboration of synovial fluid constituents. FLS were cultured in spherical extracellular matrix (ECM) micromasses for 3 weeks. The FLS micromass architecture was assessed histologically and compared with that of dermal fibroblast controls. Lubricin synthesis was measured via immunodetection. Basement membrane matrix and reticular fiber stains were performed to examine ECM organization. Primary human and mouse monocytes were prepared and cocultured with FLS in micromass to investigate cocompaction in the lining architecture. Cytokine stimuli were applied to determine the capacity for inflammatory architecture rearrangement. FLS, but not dermal fibroblasts, spontaneously formed a compacted lining architecture over 3 weeks in the 3-D ECM micromass organ cultures. These lining cells produced lubricin. FLS rearranged their surrounding ECM into a complex architecture resembling the synovial lining and supported the survival and cocompaction of monocyte/macrophages in the neo-lining structure. Furthermore, when stimulated by cytokines, FLS lining structures displayed features of the hyperplastic rheumatoid arthritis synovial lining. This 3-D micromass organ culture method demonstrates that many of the phenotypic characteristics of the normal and the hyperplastic synovial lining in vivo are intrinsic functions of FLS. Moreover, FLS promote survival and cocompaction of primary monocytes in a manner remarkably similar to that of synovial lining macrophages. These findings provide new insight into inherent functions of the FLS lineage and establish a powerful in vitro method for further investigation of this lineage.

A human pericardium biopolymeric scaffold for autologous heart valve tissue engineering: cellular and extracellular matrix structure and biomechanical properties in comparison with a normal aortic heart valve.

PubMed

Straka, Frantisek; Schornik, David; Masin, Jaroslav; Filova, Elena; Mirejovsky, Tomas; Burdikova, Zuzana; Svindrych, Zdenek; Chlup, Hynek; Horny, Lukas; Daniel, Matej; Machac, Jiri; Skibová, Jelena; Pirk, Jan; Bacakova, Lucie

2018-04-01

The objective of our study was to compare the cellular and extracellular matrix (ECM) structure and the biomechanical properties of human pericardium (HP) with the normal human aortic heart valve (NAV). HP tissues (from 12 patients) and NAV samples (from 5 patients) were harvested during heart surgery. The main cells in HP were pericardial interstitial cells, which are fibroblast-like cells of mesenchymal origin similar to the valvular interstitial cells in NAV tissue. The ECM of HP had a statistically significantly (p < 0.001) higher collagen I content, a lower collagen III and elastin content, and a similar glycosaminoglycans (GAGs) content, in comparison with the NAV, as measured by ECM integrated density. However, the relative thickness of the main load-bearing structures of the two tissues, the dense part of fibrous HP (49 ± 2%) and the lamina fibrosa of NAV (47 ± 4%), was similar. In both tissues, the secant elastic modulus (Es) was significantly lower in the transversal direction (p < 0.05) than in the longitudinal direction. This proved that both tissues were anisotropic. No statistically significant differences in UTS (ultimate tensile strength) values and in calculated bending stiffness values in the longitudinal or transversal direction were found between HP and NAV. Our study confirms that HP has an advantageous ECM biopolymeric structure and has the biomechanical properties required for a tissue from which an autologous heart valve replacement may be constructed.

Lytic and mechanical stability of clots composed of fibrin and blood vessel wall components.

PubMed

Rottenberger, Z; Komorowicz, E; Szabó, L; Bóta, A; Varga, Z; Machovich, R; Longstaff, C; Kolev, K

2013-03-01

Proteases expressed in atherosclerotic plaque lesions generate collagen fragments, release glycosaminoglycans (chondroitin sulfate [CS] and dermatan sulfate [DS]) and expose extracellular matrix (ECM) proteins (e.g. decorin) at sites of fibrin formation. Here we address the effect of these vessel wall components on the lysis of fibrin by the tissue plasminogen activator (tPA)/plasminogen system and on the mechanical stability of clots. MMP-8-digested collagen fragments, isolated CS, DS, glycosylated decorin and its core protein were used to prepare mixed matrices with fibrin (additives present at a 50-fold lower mass concentration than fibrinogen). Scanning electron microscopy (SEM) showed that the presence of ECM components resulted in a coarse fibrin structure, most pronounced for glycosylated decorin causing an increase in the median fiber diameter from 85 to 187 nm. Rheological measurements indicated that these structural alterations were coupled to decreased shear resistance (1.8-fold lower shear stress needed for gel/fluid transition of the clots containing glycosylated decorin) and rigidity (reduction of the storage modulus from 54.3 to 33.2 Pa). The lytic susceptibility of the modified fibrin structures was increased. The time to 50% lysis by plasmin was reduced approximately 2-fold for all investigated ECM components (apart from the core protein of decorin which produced a moderate reduction of the lysis time by 25%), whereas fibrin-dependent plasminogen activation by tPA was inhibited by up to 30%. ECM components compromise the chemical and mechanical stability of fibrin as a result of changes in its ultrastructure. © 2012 International Society on Thrombosis and Haemostasis.

Stiffness of hyaluronic acid gels containing liver extracellular matrix supports human hepatocyte function and alters cell morphology.

PubMed

Deegan, Daniel B; Zimmerman, Cynthia; Skardal, Aleksander; Atala, Anthony; Shupe, Thomas D

2015-03-01

Tissue engineering and cell based liver therapies have utilized primary hepatocytes with limited success due to the failure of hepatocytes to maintain their phenotype in vitro. In order to overcome this challenge, hyaluronic acid (HA) cell culture substrates were formulated to closely mimic the composition and stiffness of the normal liver cellular microenvironment. The stiffness of the substrate was modulated by adjusting HA hydrogel crosslinking. Additionally, the repertoire of bioactive molecules within the HA substrate was bolstered by supplementation with normal liver extracellular matrix (ECM). Primary human hepatocyte viability and phenotype were determined over a narrow physiologically relevant range of substrate stiffnesses from 600 to 4600Pa in both the presence and absence of liver ECM. Cell attachment, viability, and organization of the actin cytoskeleton improved with increased stiffness up to 4600Pa. These differences were not evident in earlier time points or substrates containing only HA. However, gene expression for the hepatocyte markers hepatocyte nuclear factor 4 alpha (HNF4α) and albumin significantly decreased on the 4600Pa stiffness at day 7 indicating that cells may not have maintained their phenotype long-term at this stiffness. Function, as measured by albumin secretion, varied with both stiffness and time in culture and peaked at day 7 at the 1200Pa stiffness, slightly below the stiffness of normal liver ECM at 3000Pa. Overall, gel stiffness affected primary human hepatocyte cell adhesion, functional marker expression, and morphological characteristics dependent on both the presence of liver ECM in gel substrates and time in culture. Copyright © 2015 Elsevier Ltd. All rights reserved.

An arctic community of symbiotic fungi assembled by long-distance dispersers: phylogenetic diversity of ectomycorrhizal basidiomycetes in Svalbard based on soil and sporocarp DNA

Treesearch

J. Geml; I. Timling; C.H. Robinson; N. Lennon; H.C. Nusbaum; C. Brochmann; M.E. Noordeloos; D.L. Taylor

2011-01-01

Current evidence from temperate studies suggests that ectomycorrhizal (ECM) fungi require overland routes for migration because of their obligate symbiotic associations with woody plants. Despite their key roles in arctic ecosystems, the phylogenetic diversity and phylogeography of arctic ECM fungi remains little known. Here we assess the phylogenetic diversity of ECM...

Magnetomotive optical coherence elastography for relating lung structure and function in cystic fibrosis

NASA Astrophysics Data System (ADS)

Chhetri, Raghav K.; Carpenter, Jerome; Superfine, Richard; Randell, Scott H.; Oldenburg, Amy L.

2010-02-01

Cystic fibrosis (CF) is a genetic defect in the cystic fibrosis transmembrane conductance regulator protein and is the most common life-limiting genetic condition affecting the Caucasian population. It is an autosomal recessive, monogenic inherited disorder characterized by failure of airway host defense against bacterial infection, which results in bronchiectasis, the breakdown of airway wall extracellular matrix (ECM). In this study, we show that the in vitro models consisting of human tracheo-bronchial-epithelial (hBE) cells grown on porous supports with embedded magnetic nanoparticles (MNPs) at an air-liquid interface are suitable for long term, non-invasive assessment of ECM remodeling using magnetomotive optical coherence elastography (MMOCE). The morphology of ex vivo CF and normal lung tissues using OCT and correlative study with histology is also examined. We also demonstrate a quantitative measure of normal and CF airway elasticity using MMOCE. The improved understanding of pathologic changes in CF lung structure and function and the novel method of longitudinal in vitro ECM assessment demonstrated in this study may lead to new in vivo imaging and elastography methods to monitor disease progression and treatment in cystic fibrosis.

Semicarbazide-sensitive amine oxidase and extracellular matrix deposition by smooth-muscle cells

NASA Technical Reports Server (NTRS)

Langford, Shannon D.; Trent, Margaret B.; Boor, Paul J.

2002-01-01

We have recently reported in vivo disruption of collagen and elastin architecture within blood vessel walls resulting from the selective inhibition of the enzyme semicarbazide-sensitive amine oxidase (SSAO). This study further investigates the effects of SSAO inhibition on extracellular matrix deposition by smooth-muscle cells (SMCs) cultured from neonatal rat hearts. SMCs were characterized, SSAO activity was measured, and soluble and insoluble collagen and elastin in the extracellular matrix (ECM) were quantified. Cultured neonatal rat heart SMC exhibited a monotypic synthetic phenotype that likely represents a myofibroblast. Detectable levels of SSAO activity present throughout 30-d culture peaked at 7-14 d, coinciding with the production of ECM. The addition of enzyme inhibitors and alternate SSAO substrates (benzylamine) produced varied and, in some cases, marked changes in SSAO activity as well as in the composition of mature and soluble matrix components. Similar to our previous in vivo findings, in vitro SSAO inhibition produced aberrations in collagen and elastin deposition by heart SMC. Because changes in SSAO activity are associated with cardiovascular pathologic states, this enzyme may play a protective or modulating role by regulating ECM production during pathologic insult.

Collisional super-Penrose process and Wald inequalities

NASA Astrophysics Data System (ADS)

Tanatarov, Igor V.; Zaslavskii, Oleg B.

2017-09-01

We consider collision of two massive particles in the equatorial plane of an axially symmetric stationary spacetime that produces two massless particles afterwards. It is implied that the horizon is absent but there is a naked singularity or another potential barrier that makes possible the head-on collision. The relationship between the energy in the center of mass frame E_{c.m.} and the Killing energy E measured at infinity is analyzed. It follows immediately from the Wald inequalities that unbounded E is possible for unbounded E_{c.m.} only. This can be realized if the spacetime is close to the threshold of the horizon formation. Different types of spacetimes (black holes, naked singularities, wormholes) correspond to different possible relations between E_{c.m.} and E. We develop a general approach that enables us to describe the collision process in the frames of the stationary observer and zero angular momentum observer. The escape cone and escape fraction are derived. A simple explanation of the existence of the bright spot is given. For the particular case of the Kerr metric, our results agree with the previous ones found in Patil et al. (Phys Rev D 93:104015, 2016).

Vocal fold tissue failure: preliminary data and constitutive modeling.

PubMed

Chan, Roger W; Siegmund, Thomas

2004-08-01

In human voice production (phonation), linear small-amplitude vocal fold oscillation occurs only under restricted conditions. Physiologically, phonation more often involves large-amplitude oscillation associated with tissue stresses and strains beyond their linear viscoelastic limits, particularly in the lamina propria extracellular matrix (ECM). This study reports some preliminary measurements of tissue deformation and failure response of the vocal fold ECM under large-strain shear The primary goal was to formulate and test a novel constitutive model for vocal fold tissue failure, based on a standard-linear cohesive-zone (SL-CZ) approach. Tissue specimens of the sheep vocal fold mucosa were subjected to torsional deformation in vitro, at constant strain rates corresponding to twist rates of 0.01, 0.1, and 1.0 rad/s. The vocal fold ECM demonstrated nonlinear stress-strain and rate-dependent failure response with a failure strain as low as 0.40 rad. A finite-element implementation of the SL-CZ model was capable of capturing the rate dependence in these preliminary data, demonstrating the model's potential for describing tissue failure. Further studies with additional tissue specimens and model improvements are needed to better understand vocal fold tissue failure.

Analysis of the Negative-SET Behaviors in Cu/ZrO2/Pt Devices

NASA Astrophysics Data System (ADS)

Liu, Sen; Zhao, Xiaolong; Li, Qingjiang; Li, Nan; Wang, Wei; Liu, Qi; Xu, Hui

2016-12-01

Metal oxide-based electrochemical metallization memory (ECM) shows promising performance for next generation non-volatile memory. The negative-SET behavior has been observed in various oxide-based ECM devices. But the underlying mechanism of this behavior remains unaddressed and the role of the metal cation and oxygen vacancy in this behavior is unclear. In this work, we have observed two kinds of negative-SET (labeled as N-SET1 and N-SET2) behaviors in our Cu/ZrO2/Pt devices. Both the two behaviors can result in hard breakdown due to the high compliance current in reset process. The I-V characteristic shows that the two negative-SET behaviors have an obvious difference in operation voltage. Using four-probe resistance measurement method, the resistance-temperature characteristics of the ON-state after various negative-SET behaviors have been studied. The temperature dependence results demonstrate that the N-SET1 behavior is dominated by Cu conductive filament (CF) reformation caused by the Cu CF overgrowth phenomenon while the N-SET2 is related to the formation of oxygen vacancy CF. This work may provide a comprehensive understanding of the switching mechanism in oxide-based ECM devices.

Modulation of extracellular matrix in cancer is associated with enhanced tumor cell targeting by bacteriophage vectors.

PubMed

Yata, Teerapong; Lee, Eugene L Q; Suwan, Keittisak; Syed, Nelofer; Asavarut, Paladd; Hajitou, Amin

2015-06-03

Gene therapy has been an attractive paradigm for cancer treatment. However, cancer gene therapy has been challenged by the inherent limitation of vectors that are able to deliver therapeutic genes to tumors specifically and efficiently following systemic administration. Bacteriophage (phage) are viruses that have shown promise for targeted systemic gene delivery. Yet, they are considered poor vectors for gene transfer. Recently, we generated a tumor-targeted phage named adeno-associated virus/phage (AAVP), which is a filamentous phage particle whose genome contains the adeno-associated virus genome. Its effectiveness in delivering therapeutic genes to tumors specifically both in vitro and in vivo has been shown in numerous studies. Despite being a clinically useful vector, a multitude of barriers impede gene transduction to tumor cells. We hypothesized that one such factor is the tumor extracellular matrix (ECM). We used a number of tumor cell lines from different species and histological types in 2D monolayers or 3D multicellular tumor spheroid (MCTS) models. To assess whether the ECM is a barrier to tumor cell targeting by AAVP, we depleted the ECM using collagenase, hyaluronidase, or combination of both. We employed multiple techniques to investigate and quantify the effect of ECM depletion on ECM composition (including collagen type I, hyaluronic acid, fibronectin and laminin), and how AAVP adsorption, internalisation, gene expression and therapeutic efficacy are subsequently affected. Data were analyzed using a student's t test when comparing two groups or one-way ANOVA and post hoc Tukey tests when using more than two groups. We demonstrate that collagenase and hyaluronidase-mediated degradation of tumor ECM affects the composition of collagen, hyaluronic acid and fibronectin. Consequently, AAVP diffusion, internalisation, gene expression and tumor cell killing were enhanced after enzymatic treatment. Our data suggest that enhancement of gene transfer by the AAVP is solely attributed to ECM depletion. We provide substantial evidence that ECM modulation is relevant in clinically applicable settings by using 3D MCTS, which simulates in vivo environments more accurately. Our findings suggest that ECM depletion is an effective strategy to enhance the efficiency of viral vector-guided gene therapy.

Supercritical carbon dioxide extracted extracellular matrix material from adipose tissue.

PubMed

Wang, Jun Kit; Luo, Baiwen; Guneta, Vipra; Li, Liang; Foo, Selin Ee Min; Dai, Yun; Tan, Timothy Thatt Yang; Tan, Nguan Soon; Choong, Cleo; Wong, Marcus Thien Chong

2017-06-01

Adipose tissue is a rich source of extracellular matrix (ECM) material that can be isolated by delipidating and decellularizing the tissue. However, the current delipidation and decellularization methods either involve tedious and lengthy processes or require toxic chemicals, which may result in the elimination of vital proteins and growth factors found in the ECM. Hence, an alternative delipidation and decellularization method for adipose tissue was developed using supercritical carbon dioxide (SC-CO 2 ) that eliminates the need of any harsh chemicals and also reduces the amount of processing time required. The resultant SC-CO 2 -treated ECM material showed an absence of nuclear content but the preservation of key proteins such as collagen Type I, collagen Type III, collagen Type IV, elastin, fibronectin and laminin. In addition, other biological factors such as glycosaminoglycans (GAGs) and growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were also retained. Subsequently, the resulting SC-CO 2 -treated ECM material was used as a bioactive coating on tissue culture plastic (TCP). Four different cell types including adipose tissue-derived mesenchymal stem cells (ASCs), human umbilical vein endothelial cells (HUVECs), immortalized human keratinocyte (HaCaT) cells and human monocytic leukemia cells (THP-1) were used in this study to show that the SC-CO 2 -treated ECM coating can be potentially used for various biomedical applications. The SC-CO 2 -treated ECM material showed improved cell-material interactions for all cell types tested. In addition, in vitro scratch wound assay using HaCaT cells showed that the presence of SC-CO 2 -treated ECM material enhanced keratinocyte migration whilst the in vitro cellular studies using THP-1-derived macrophages showed that the SC-CO 2 -treated ECM material did not evoke pro-inflammatory responses from the THP-1-derived macrophages. Overall, this study shows the efficacy of SC-CO 2 method for delipidation and decellularization of adipose tissue whilst retaining its ECM and its subsequent utilization as a bioactive surface coating material for soft tissue engineering, angiogenesis and wound healing applications. Copyright © 2017 Elsevier B.V. All rights reserved.

ECM1 and TMPRSS4 Are Diagnostic Markers of Malignant Thyroid Neoplasms and Improve the Accuracy of Fine Needle Aspiration Biopsy

PubMed Central

Kebebew, Electron; Peng, Miao; Reiff, Emily; Duh, Quan-Yang; Clark, Orlo H.; McMillan, Alex

2005-01-01

Objective: The objective of this study was to determine whether genes that regulate cellular invasion and metastasis are differentially expressed and could serve as diagnostic markers of malignant thyroid nodules. Summary and Background Data: Patients whose thyroid nodules have indeterminate or suspicious cytologic features on fine needle aspiration (FNA) biopsy require thyroidectomy because of a 20% to 30% risk of thyroid cancer. Cell invasion and metastasis is a hallmark of malignant phenotype; therefore, genes that regulate these processes might be differentially expressed and could serve as diagnostic markers of malignancy. Methods: Differentially expressed genes (2-fold higher or lower) in malignant versus benign thyroid neoplasms were identified by extracellular matrix and adhesion molecule cDNA array analysis and confirmed by real-time quantitative polymerase chain reaction (PCR). The area under the receiver operating characteristic (AUC) curve was calculated to determine diagnostic accuracy of gene expression level cutoffs established by logistic regression analysis. Results: By cDNA array analysis, ADAMTS8, ECM1, MMP8, PLAU, SELP, and TMPRSS4 were upregulated, and by quantitative PCR, ECM1, SELP, and TMPRSS4 mRNA expression was higher in malignant (n = 57) than in benign (n = 38) thyroid neoplasms (P< 0.002). ECM1 and TMPRSS4 mRNA expression levels were independent predictors of a malignant thyroid neoplasm (P < 0.003). The AUC was 0.956 for ECM1 and 0.926 for TMPRSS4. Combining both markers improved their diagnostic use (AUC 0.985; sensitivity, 91.7%; specificity, 89.8%; positive predictive value, 85.7%; negative predictive value, 82.8%). ECM1 and TMPRSS4 expression analysis improved the diagnostic accuracy of FNA biopsy in 35 of 38 indeterminate or suspicious results. The level of ECM1 mRNA expression was higher in TNM stage I differentiated thyroid cancers than in stage II and III tumors (P ≤ 0.031). Conclusions: ECM1 and TMPRSS4 are excellent diagnostic markers of malignant thyroid nodules and may be used to improve the diagnostic accuracy of FNA biopsy. ECM1 is also a marker of the extent of disease in differentiated thyroid cancers. PMID:16135921

The History of Early Polar Ice Cores

DTIC Science & Technology

2008-01-01

different aspects of the research discussed herein; they include J. Weertman, R, Rutford, G. Denton, H. Ueda, J. Brown, G. Frankenstein , B. Stauffer, H...continuously measure micro-particle concentrations and eruptive volcanic-acid horizons by the new electrical conductivity method (ECM) invented by

Validation of masks for determination of V̇O2 max in horses exercising at high intensity.

PubMed

Sides, R H; Kirkpatrick, R; Renner, E; Gough, K; Katz, L M; Evans, D L; Bayly, W M

2018-01-01

The need for a horse to be ridden while wearing a measurement device that allows unrestricted ventilation and gas exchange has hampered accurate measurement of its maximal oxygen consumption (V̇O 2 max) under field conditions. Design and validate a facemask with the potential to measure V̇O 2 max accurately in the field. Experiment with 6 × 6 Latin square design. Two variations of a mask and associated electronic control module (ECM) were designed to enable breath-by-breath measurement of airflows through two 7.8 cm diameter pneumotachometers located 7.5 cm in front of each narus. The ECM was comprised of an analogue-to-digital converter and a lithium-ion battery that provided power and signal filtering to the pneumotachometers and an oxygen sensing cell, and powered a pump connected to gas sampling ports between the nares and pneumotachometers. Airflow and oxygen content of inspired and expired gases were recorded through the ECM and electronically transferred to a notebook. V̇O 2 was determined from these recordings using a customised software program. Mask B encased the lower jaw. Mask R left the jaw free so the horse could wear a bit if ridden. V̇O 2 max and arterial blood gases were measured in 6 horses during multiple treadmill tests. Each mask was worn twice and results compared to those from an established open flow-through system (O) by ANOVA-RM (P<0.05). System utility was evaluated using the intraclass correlation coefficient of 4 independent raters. Blood gases and V̇O 2 max (151.9±7.0 [mean±s.d.; O], 151.5±9.6 [B], 149.5±7.5 [R] ml/[kg.min]) were not different between masks. V̇O 2 max measures were reproducible for each mask. Intraclass correlation coefficient between raters = 0.99. Some rebreathing of expired air from mask dead space. Masks capable of measuring V̇O 2 max during treadmill exercise were developed, tested and found to be accurate. Mask R has potential application to measurement of V̇O 2 max under field conditions. © 2017 EVJ Ltd.

Collagen and related extracellular matrix proteins in atherosclerotic plaque development.

PubMed

Shami, Annelie; Gonçalves, Isabel; Hultgårdh-Nilsson, Anna

2014-10-01

The structure, composition and turnover of the extracellular matrix (ECM) as well as cell-matrix interactions are crucial in the developing atherosclerotic plaque. There is a need for further insight into specific proteins in the ECM and their functions in the developing plaque, and during the last few years a number of publications have highlighted this very important field of research. These novel findings will be addressed in the present review. This review covers literature focused on collagen and ECM proteins interacting with collagen, and what their roles may be in plaque development. Acute myocardial infarction and stroke are common diseases that cause disability and mortality, and the underlying mechanism is often the rupture of a vulnerable atherosclerotic plaque. The vascular ECM and the tissue repair in the atherosclerotic lesion are important players in plaque progression. Understanding how specific proteins in the ECM interact with cells in the plaque and affect the fate of the plaque can lead to new treatments for cardiovascular disease.

Myogenic Progenitor Cells Control Extracellular Matrix Production by Fibroblasts during Skeletal Muscle Hypertrophy.

PubMed

Fry, Christopher S; Kirby, Tyler J; Kosmac, Kate; McCarthy, John J; Peterson, Charlotte A

2017-01-05

Satellite cells, the predominant stem cell population in adult skeletal muscle, are activated in response to hypertrophic stimuli and give rise to myogenic progenitor cells (MPCs) within the extracellular matrix (ECM) that surrounds myofibers. This ECM is composed largely of collagens secreted by interstitial fibrogenic cells, which influence satellite cell activity and muscle repair during hypertrophy and aging. Here we show that MPCs interact with interstitial fibrogenic cells to ensure proper ECM deposition and optimal muscle remodeling in response to hypertrophic stimuli. MPC-dependent ECM remodeling during the first week of a growth stimulus is sufficient to ensure long-term myofiber hypertrophy. MPCs secrete exosomes containing miR-206, which represses Rrbp1, a master regulator of collagen biosynthesis, in fibrogenic cells to prevent excessive ECM deposition. These findings provide insights into how skeletal stem and progenitor cells interact with other cell types to actively regulate their extracellular environments for tissue maintenance and adaptation. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Xu, Ren; Boudreau, Aaron; Bissell, Mina J

Mammary gland development, functional differentiation, and homeostasis are orchestrated and sustained by a balance of biochemical and biophysical cues from the organ's microenvironment. The three-dimensional microenvironment of the mammary gland, predominantly 'encoded' by a collaboration between the extracellular matrix (ECM), hormones, and growth factors, sends signals from ECM receptors through the cytoskeletal intracellular matrix to nuclear and chromatin structures resulting in gene expression; the ECM in turn is regulated and remodeled by signals from the nucleus. In this chapter, we discuss how coordinated ECM deposition and remodeling is necessary for mammary gland development, how the ECM provides structural and biochemicalmore » cues necessary for tissue-specific function, and the role of the cytoskeleton in mediating the extra - to intracellular dialogue occurring between the nucleus and the microenvironment. When operating normally, the cytoskeletal-mediated dynamic and reciprocal integration of tissue architecture and function directs mammary gland development, tissue polarity, and ultimately, tissue-specific gene expression. Cancer occurs when these dynamic interactions go awry for an extended time.« less

Global Gene Expression Analysis in PKCα-/- Mouse Skin Reveals Structural Changes in the Dermis and Defective Wound Granulation Tissue.

PubMed

Cooper, Nichola H; Balachandra, Jeya P; Hardman, Matthew J

2015-12-01

The skin's mechanical integrity is maintained by an organized and robust dermal extracellular matrix (ECM). Resistance to mechanical disruption hinges primarily on homeostasis of the dermal collagen fibril architecture, which is regulated, at least in part, by members of the small leucine-rich proteoglycan (SLRP) family. Here we present data linking protein kinase C alpha (PKCα) to the regulated expression of multiple ECM components including SLRPs. Global microarray profiling reveals deficiencies in ECM gene expression in PKCα-/- skin correlating with abnormal collagen fibril morphology, disorganized dermal architecture, and reduced skin strength. Detailed analysis of the skin and wounds from wild-type and PKCα-/- mice reveals a failure to upregulate collagen and other ECM components in response to injury, resulting in delayed granulation tissue deposition in PKCα-/- wounds. Thus, our data reveal a previously unappreciated role for PKCα in the regulation of ECM structure and deposition during skin wound healing.

Engineering hydrogels as extracellular matrix mimics

PubMed Central

Geckil, Hikmet; Xu, Feng; Zhang, Xiaohui; Moon, SangJun

2010-01-01

Extracellular matrix (ECM) is a complex cellular environment consisting of proteins, proteoglycans, and other soluble molecules. ECM provides structural support to mammalian cells and a regulatory milieu with a variety of important cell functions, including assembling cells into various tissues and organs, regulating growth and cell–cell communication. Developing a tailored in vitro cell culture environment that mimics the intricate and organized nanoscale meshwork of native ECM is desirable. Recent studies have shown the potential of hydrogels to mimic native ECM. Such an engineered native-like ECM is more likely to provide cells with rational cues for diagnostic and therapeutic studies. The research for novel biomaterials has led to an extension of the scope and techniques used to fabricate biomimetic hydrogel scaffolds for tissue engineering and regenerative medicine applications. In this article, we detail the progress of the current state-of-the-art engineering methods to create cell-encapsulating hydrogel tissue constructs as well as their applications in in vitro models in biomedicine. PMID:20394538

Tumor Mechanics and Metabolic Dysfunction

PubMed Central

Tung, Jason C.; Barnes, J. Matthew; Desai, Shraddha R.; Sistrunk, Christopher; Conklin, Matthew; Schedin, Pepper; Keely, Patricia J.; Seewaldt, Victoria L.; Weaver, Valerie M.

2015-01-01

Desmosplasia is a characteristic of most solid tumors and leads to fibrosis through abnormal extracellular matrix (ECM) deposition, remodeling and post translational modifications. The resulting stiff tumor stroma not only compromises vascular integrity to induce hypoxia and impede drug delivery, but also promotes aggressiveness by potentiating the activity of key growth, invasion, and survival pathways. Intriguingly, many of the pro-tumorigenic signaling pathways which are mechanically activated by ECM stiffness also promote glucose uptake and aerobic glycolysis, and an altered metabolism is a recognized hallmark of cancer. Indeed, emerging evidence suggests that metabolic alterations and an abnormal ECM may cooperatively drive cancer cell aggression and treatment resistance. Accordingly, improved methods to monitor tissue mechanics and metabolism promise to improve diagnostics and treatments to ameliorate ECM stiffening and elevated mechanosignaling may improve patient outcome. Here we discuss the interplay between ECM mechanics and metabolism in tumor biology and suggest that monitoring these processes and targeting their regulatory pathways may improve diagnostics, therapy, and the prevention of malignant transformation. PMID:25532934

In Sickness and in Health: Perineuronal Nets and Synaptic Plasticity in Psychiatric Disorders

PubMed Central

Pantazopoulos, Harry; Berretta, Sabina

2016-01-01

Rapidly emerging evidence implicates perineuronal nets (PNNs) and extracellular matrix (ECM) molecules that compose or interact with PNNs, in the pathophysiology of several psychiatric disorders. Studies on schizophrenia, autism spectrum disorders, mood disorders, Alzheimer's disease, and epilepsy point to the involvement of ECM molecules such as chondroitin sulfate proteoglycans, Reelin, and matrix metalloproteases, as well as their cell surface receptors. In many of these disorders, PNN abnormalities have also been reported. In the context of the “quadripartite” synapse concept, that is, the functional unit composed of the pre- and postsynaptic terminals, glial processes, and ECM, and of the role that PNNs and ECM molecules play in regulating synaptic functions and plasticity, these findings resonate with one of the most well-replicated aspects of the pathology of psychiatric disorders, that is, synaptic abnormalities. Here we review the evidence for PNN/ECM-related pathology in these disorders, with particular emphasis on schizophrenia, and discuss the hypothesis that such pathology may significantly contribute to synaptic dysfunction. PMID:26839720

ECM and ECM-like materials - Biomaterials for applications in regenerative medicine and cancer therapy.

PubMed

Hinderer, Svenja; Layland, Shannon Lee; Schenke-Layland, Katja

2016-02-01

Regenerative strategies such as stem cell-based therapies and tissue engineering applications are being developed with the aim to replace, remodel, regenerate or support damaged tissues and organs. In addition to careful cell type selection, the design of appropriate three-dimensional (3D) scaffolds is essential for the generation of bio-inspired replacement tissues. Such scaffolds are usually made of degradable or non-degradable biomaterials and can serve as cell or drug carriers. The development of more effective and efficient drug carrier systems is also highly relevant for novel cancer treatment strategies. In this review, we provide a summary of current approaches that employ ECM and ECM-like materials, or ECM-synthetic polymer hybrids, as biomaterials in the field of regenerative medicine. We further discuss the utilization of such materials for cell and drug delivery, and highlight strategies for their use as vehicles for cancer therapy. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Optical metrics of the extracellular matrix predict compositional and mechanical changes after myocardial infarction

NASA Astrophysics Data System (ADS)

Quinn, Kyle P.; Sullivan, Kelly E.; Liu, Zhiyi; Ballard, Zachary; Siokatas, Christos; Georgakoudi, Irene; Black, Lauren D.

2016-11-01

Understanding the organization and mechanical function of the extracellular matrix (ECM) is critical for the development of therapeutic strategies that regulate wound healing following disease or injury. However, these relationships are challenging to elucidate during remodeling following myocardial infarction (MI) due to rapid changes in cellularity and an inability to characterize both ECM microstructure and function non-destructively. In this study, we overcome those challenges through whole organ decellularization and non-linear optical microscopy to directly relate the microstructure and mechanical properties of myocardial ECM. We non-destructively quantify collagen organization, content, and cross-linking within decellularized healthy and infarcted myocardium using second harmonic generation (SHG) and two photon excited autofluorescence. Tensile mechanical testing and compositional analysis reveal that the cumulative SHG intensity within each image volume and the average collagen autofluorescence are significantly correlated with collagen content and elastic modulus of the ECM, respectively. Compared to healthy ECM, infarcted tissues demonstrate a significant increase in collagen content and fiber alignment, and a decrease in cross-linking and elastic modulus. These findings indicate that cross-linking plays a key role in stiffness at the collagen fiber level following infarction, and highlight how this non-destructive approach to assessing remodeling can be used to understand ECM structure-function relationships.

Extracellular matrix control of mammary gland morphogenesis and tumorigenesis: insights from imaging

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

Ghajar, Cyrus M; Bissell, Mina J

2008-10-23

The extracellular matrix (ECM), once thought to solely provide physical support to a tissue, is a key component of a cell's microenvironment responsible for directing cell fate and maintaining tissue specificity. It stands to reason, then, that changes in the ECM itself or in how signals from the ECM are presented to or interpreted by cells can disrupt tissue organization; the latter is a necessary step for malignant progression. In this review, we elaborate on this concept using the mammary gland as an example. We describe how the ECM directs mammary gland formation and function, and discuss how a cell'smore » inability to interpret these signals - whether as a result of genetic insults or physicochemical alterations in the ECM - disorganizes the gland and promotes malignancy. By restoring context and forcing cells to properly interpret these native signals, aberrant behavior can be quelled and organization re-established. Traditional imaging approaches have been a key complement to the standard biochemical, molecular, and cell biology approaches used in these studies. Utilizing imaging modalities with enhanced spatial resolution in live tissues may uncover additional means by which the ECM regulates tissue structure, on different length scales, through its pericellular organization (short-scale) and by biasing morphogenic and morphostatic gradients (long-scale).« less

Human acellular dermal wound matrix: evidence and experience.

PubMed

Kirsner, Robert S; Bohn, Greg; Driver, Vickie R; Mills, Joseph L; Nanney, Lillian B; Williams, Marie L; Wu, Stephanie C

2015-12-01

A chronic wound fails to complete an orderly and timely reparative process and places patients at increased risk for wound complications that negatively impact quality of life and require greater health care expenditure. The role of extracellular matrix (ECM) is critical in normal and chronic wound repair. Not only is ECM the largest component of the dermal skin layer, but also ECM proteins provide structure and cell signalling that are necessary for successful tissue repair. Chronic wounds are characterised by their inflammatory and proteolytic environment, which degrades the ECM. Human acellular dermal matrices, which provide an ECM scaffold, therefore, are being used to treat chronic wounds. The ideal human acellular dermal wound matrix (HADWM) would support regenerative healing, providing a structure that could be repopulated by the body's cells. Experienced wound care investigators and clinicians discussed the function of ECM, the evidence related to a specific HADWM (Graftjacket(®) regenerative tissue matrix, Wright Medical Technology, Inc., licensed by KCI USA, Inc., San Antonio, TX), and their clinical experience with this scaffold. This article distills these discussions into an evidence-based and practical overview for treating chronic lower extremity wounds with this HADWM. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Transfer to forest nurseries significantly affects mycorrhizal community composition of Asteropeia mcphersonii wildings.

PubMed

Henry, Charline; Raivoarisoa, Jeanne-Françoise; Razafimamonjy, Angélo; Ramanankierana, Heriniaina; Andrianaivomahefa, Paul; Ducousso, Marc; Selosse, Marc-André

2017-05-01

Mycorrhizal symbiosis is extremely important for tree growth, survival and resistance after transplantation particularly in Madagascar where deforestation is a major concern. The importance of mycorrhizal symbiosis is further increased when soil conditions at the planting site are limiting. To identify technical itineraries capable of improving ecological restoration in Madagascar, we needed to obtain native ectomycorrhizal (ECM) saplings with a wide diversity of ECM fungi. To this end, we transplanted ECM seedlings from the wild (wildlings) to a nursery. Using molecular characterisation of internal transcribed spacer (ITS) rDNA, we tested the effect of transplanting Asteropeia mcphersonii wildlings on ECM communities after 8 months of growth in the nursery. With or without the addition of soil from the site where the seedlings were sampled to the nursery substrate, we observed a dramatic change in the composition of fungal communities with a decrease in the ECM infection rate, a tremendous increase in the abundance of an operational taxonomic unit (OTU) taxonomically close to the order Trechisporales and the disappearance of all OTUs of Boletales. Transplanting to the nursery and/or to nursery conditions was shown to be incompatible with the survival and even less with the development in the nursery of most ECM fungi naturally associated with A. mcphersonii wildings.

Pinus pinaster seedlings and their fungal symbionts show high plasticity in phosphorus acquisition in acidic soils.

PubMed

Ali, M A; Louche, J; Legname, E; Duchemin, M; Plassard, C

2009-12-01

Young seedlings of maritime pine (Pinus pinaster Soland in Aït.) were grown in rhizoboxes using intact spodosol soil samples from the southwest of France, in Landes of Gascogne, presenting a large variation of phosphorus (P) availability. Soils were collected from a 93-year-old unfertilized stand and a 13-year-old P. pinaster stand with regular annual fertilization of either only P or P and nitrogen (N). After 6 months of culture in controlled conditions, different morphotypes of ectomycorrhiza (ECM) were used for the measurements of acid phosphatase activity and molecular identification of fungal species using amplification of the ITS region. Total biomass, N and P contents were measured in roots and shoots of plants. Bicarbonate- and NaOH-available inorganic P (Pi), organic P (Po) and ergosterol concentrations were measured in bulk and rhizosphere soil. The results showed that bulk soil from the 93-year-old forest stand presented the highest Po levels, but relatively higher bicarbonate-extractable Pi levels compared to 13-year-old unfertilized stand. Fertilizers significantly increased the concentrations of inorganic P fractions in bulk soil. Ergosterol contents in rhizosphere soil were increased by fertilizer application. The dominant fungal species was Rhizopogon luteolus forming 66.6% of analysed ECM tips. Acid phosphatase activity was highly variable and varied inversely with bicarbonate-extractable Pi levels in the rhizosphere soil. Total P or total N in plants was linearly correlated with total plant biomass, but the slope was steep only between total P and biomass in fertilized soil samples. In spite of high phosphatase activity in ECM tips, P availability remained a limiting nutrient in soil samples from unfertilized stands. Nevertheless young P. pinaster seedlings showed a high plasticity for biomass production at low P availability in soils.

Engineering Breast Cancer Microenvironments and 3D Bioprinting

PubMed Central

Belgodere, Jorge A.; King, Connor T.; Bursavich, Jacob B.; Burow, Matthew E.; Martin, Elizabeth C.; Jung, Jangwook P.

2018-01-01

The extracellular matrix (ECM) is a critical cue to direct tumorigenesis and metastasis. Although two-dimensional (2D) culture models have been widely employed to understand breast cancer microenvironments over the past several decades, the 2D models still exhibit limited success. Overwhelming evidence supports that three dimensional (3D), physiologically relevant culture models are required to better understand cancer progression and develop more effective treatment. Such platforms should include cancer-specific architectures, relevant physicochemical signals, stromal–cancer cell interactions, immune components, vascular components, and cell-ECM interactions found in patient tumors. This review briefly summarizes how cancer microenvironments (stromal component, cell-ECM interactions, and molecular modulators) are defined and what emerging technologies (perfusable scaffold, tumor stiffness, supporting cells within tumors and complex patterning) can be utilized to better mimic native-like breast cancer microenvironments. Furthermore, this review emphasizes biophysical properties that differ between primary tumor ECM and tissue sites of metastatic lesions with a focus on matrix modulation of cancer stem cells, providing a rationale for investigation of underexplored ECM proteins that could alter patient prognosis. To engineer breast cancer microenvironments, we categorized technologies into two groups: (1) biochemical factors modulating breast cancer cell-ECM interactions and (2) 3D bioprinting methods and its applications to model breast cancer microenvironments. Biochemical factors include matrix-associated proteins, soluble factors, ECMs, and synthetic biomaterials. For the application of 3D bioprinting, we discuss the transition of 2D patterning to 3D scaffolding with various bioprinting technologies to implement biophysical cues to model breast cancer microenvironments. PMID:29881724

In vivo xenogeneic scaffold fate is determined by residual antigenicity and extracellular matrix preservation.

PubMed

Wong, Maelene L; Wong, Janelle L; Vapniarsky, Natalia; Griffiths, Leigh G

2016-06-01

The immunological potential of animal-derived tissues and organs is the critical hurdle to increasing their clinical implementation. Glutaraldehyde-fixation cross-links proteins in xenogeneic tissues (e.g., bovine pericardium) to delay immune rejection, but also compromises the regenerative potential of the resultant biomaterial. Unfixed xenogeneic biomaterials in which xenoantigenicity has been ameliorated and native extracellular matrix (ECM) architecture has been maintained have the potential to overcome limitations of current clinically utilized glutaraldehyde-fixed biomaterials. The objective of this work was to determine how residual antigenicity and ECM architecture preservation modulate recipient immune and regenerative responses towards unfixed bovine pericardium (BP) ECM scaffolds. Disruption of ECM architecture during scaffold generation, with either SDS-decellularization or glutaraldehyde-fixation, stimulated recipient foreign body response and resultant fibrotic encapsulation following leporine subpannicular implantation. Conversely, BP scaffolds subjected to stepwise removal of hydrophilic and lipophilic antigens using amidosulfobetaine-14 (ASB-14) maintained native ECM architecture and thereby avoided fibrotic encapsulation. Removal of hydrophilic and lipophilic antigens significantly decreased local and systemic graft-specific, adaptive immune responses and subsequent calcification of BP scaffolds compared to scaffolds undergoing hydrophile removal only. Critically, removal of antigenic components and preservation of ECM architecture with ASB-14 promoted full-thickness recipient non-immune cellular repopulation of the BP scaffold. Further, unlike clinically utilized fixed BP, ASB-14-treated scaffolds fostered rapid intimal and medial vessel wall regeneration in a porcine carotid patch angioplasty model. This work highlights the importance of residual antigenicity and ECM architecture preservation in modulating recipient immune and regenerative responses towards xenogeneic biomaterial generation. Copyright © 2016. Published by Elsevier Ltd.

Phrase Mining of Textual Data to Analyze Extracellular Matrix Protein Patterns Across Cardiovascular Disease.

PubMed

Liem, David Alexandre; Murali, Sanjana; Sigdel, Dibakar; Shi, Yu; Wang, Xuan; Shen, Jiaming; Choi, Howard; Caufield, J Harry; Wang, Wei; Ping, Peipei; Han, Jiawei

2018-05-18

Extracellular matrix (ECM) proteins have been shown to play important roles regulating multiple biological processes in an array of organ systems, including the cardiovascular system. By using a novel bioinformatics text-mining tool, we studied six categories of cardiovascular disease (CVD), namely ischemic heart disease (IHD), cardiomyopathies (CM), cerebrovascular accident (CVA), congenital heart disease (CHD), arrhythmias (ARR), and valve disease (VD), anticipating novel ECM protein-disease and protein-protein relationships hidden within vast quantities of textual data. We conducted a phrase-mining analysis, delineating the relationships of 709 ECM proteins with the six groups of CVDs reported in 1,099,254 abstracts. The technology pipeline known as Context-aware Semantic Online Analytical Processing (CaseOLAP) was applied to semantically rank the association of proteins to each and all six CVDs, performing analyses to quantify each protein-disease relationship. We performed principal component analysis and hierarchical clustering of the data, where each protein is visualized as a six dimensional vector. We found that ECM proteins display variable degrees of association with the six CVDs; certain CVDs share groups of associated proteins whereas others have divergent protein associations. We identified 82 ECM proteins sharing associations with all six CVDs. Our bioinformatics analysis ascribed distinct ECM pathways (via Reactome) from this subset of proteins, namely insulin-like growth factor regulation and interleukin-4 and interleukin-13 signaling, suggesting their contribution to the pathogenesis of all six CVDs. Finally, we performed hierarchical clustering analysis and identified protein clusters associated with a targeted CVD; analyses revealed unexpected insights underlying ECM-pathogenesis of CVDs.

Fabrication of Extracellular Matrix-derived Foams and Microcarriers as Tissue-specific Cell Culture and Delivery Platforms.

PubMed

Kornmuller, Anna; Brown, Cody F C; Yu, Claire; Flynn, Lauren E

2017-04-11

Cell function is mediated by interactions with the extracellular matrix (ECM), which has complex tissue-specific composition and architecture. The focus of this article is on the methods for fabricating ECM-derived porous foams and microcarriers for use as biologically-relevant substrates in advanced 3D in vitro cell culture models or as pro-regenerative scaffolds and cell delivery systems for tissue engineering and regenerative medicine. Using decellularized tissues or purified insoluble collagen as a starting material, the techniques can be applied to synthesize a broad array of tissue-specific bioscaffolds with customizable geometries. The approach involves mechanical processing and mild enzymatic digestion to yield an ECM suspension that is used to fabricate the three-dimensional foams or microcarriers through controlled freezing and lyophilization procedures. These pure ECM-derived scaffolds are highly porous, yet stable without the need for chemical crosslinking agents or other additives that may negatively impact cell function. The scaffold properties can be tuned to some extent by varying factors such as the ECM suspension concentration, mechanical processing methods, or synthesis conditions. In general, the scaffolds are robust and easy to handle, and can be processed as tissues for most standard biological assays, providing a versatile and user-friendly 3D cell culture platform that mimics the native ECM composition. Overall, these straightforward methods for fabricating customized ECM-derived foams and microcarriers may be of interest to both biologists and biomedical engineers as tissue-specific cell-instructive platforms for in vitro and in vivo applications.

Prevalence of associated extracardiac malformations in the congenital heart disease population.

PubMed

Egbe, Alexander; Uppu, Santosh; Lee, Simon; Ho, Deborah; Srivastava, Shubhika

2014-10-01

The authors hypothesized that changes in prenatal factors such as termination of pregnancy for fetal anomalies and prenatal vitamin supplementation have altered the epidemiology of patients with multiple congenital anomalies and may have had an impact on their prevalence in the current era. This study reviewed the Nationwide Inpatient Sample database from 1998 to 2008 and compared the prevalence of ECM among live births with a CHD diagnosis (case) and that among live births without a CHD diagnosis (control). For this study, 42 ECM and 10 CHD diagnoses were selected for subanalysis. Longitudinal analysis also was performed to determine temporal variation of ECM prevalence in the CHD population during the 11-year study period. The cohort in this study consisted of 97,154 patients in the case group and 12,078,482 subjects in the control group. The prevalences in the CHD population were 11.4 % for nonsyndromic congenital malformation (NSCM), 2.2 % for genetic syndrome (GS), and 13.6 % for overall extracardiac congenital malformation (ECM). The prevalences in the control group were 6.7 % for NSCM, 0.3 % for GS, and 7.0 % for ECM. The findings showed a strong association of NSCM [odds ratio (OR) 1.88; 95 % confidence interval (CI) 1.73-1.94], GS (OR 2.52; 95 % CI 2.44-2.61), and overall ECM (OR 2.01; 95 % CI 1.97-2.14) with CHD. The prevalences of GS and multiple organ system CM decreased significantly during the study period. This study was the largest and most comprehensive population-based study to evaluate the association between CHD and ECM in newborns.

Extracolonic findings (ECF) on CT colonography (CTC) in patients presenting with colorectal symptoms.

PubMed

Badiani, Sarit; Tomas-Hernandez, Silvia; Karandikar, Sharad; Roy-Choudhury, Shuvro

2013-10-01

Computed tomographic colonography (CTC) is now an established method for imaging the colon and rectum in the screening and symptomatic setting. Additional benefit of CTC is the ability to assess for extracolonic findings especially in patients presenting with colorectal symptoms. To determine prevalence of extracolonic findings (ECF) in symptomatic patients undergoing CTC and determine accuracy of CTC for exclusion of significant abdominal disease and extracolonic malignancy (ECM). A total of 1359 unenhanced prone and postcontrast supine CTC studies were performed between March 2002 and December 2007. ECF were retrospectively classified according to C-RADS criteria into E1 to E4 findings. For ECM, a gold standard of clinical and/or radiological follow-up supplemented with data from the regional cancer registry with a median follow-up of 42 months was created. Sensitivity and negative predictive values for ECM was calculated. Following exclusions, 1177 CTCs were analyzed. Of 1423 extracolonic findings reported, 328/1423 (23%) E3 and 100/1423 (7%) E4 (including six eventual FP studies) findings were identified. Thirty-two ECMs were confirmed following further investigations. Seven further small ECMs were detected during the entire follow-up, of which two were potentially visible in retrospect (false-negative studies). Additional tests were generated from 55/1177 (4.7%) studies. Sensitivity and negative predictive value for ECM was 94.1% (95% CI 78.9-98.9%) and 99.8% (95% CI 99.3-99.9%), respectively. One in 37 patients were found to have an ECM. Two potentially detectable cancers were missed. Only a small proportion of patients underwent additional work-up.

Heparin-induced conformational changes of fibronectin within the extracellular matrix promote hMSC osteogenic differentiation.

PubMed

Li, Bojun; Lin, Zhe; Mitsi, Maria; Zhang, Yang; Vogel, Viola

2015-01-01

An increasing body of evidence suggests important roles of extracellular matrix (ECM) in regulating stem cell fate. This knowledge can be exploited in tissue engineering applications for the design of ECM scaffolds appropriate to direct stem cell differentiation. By probing the conformation of fibronectin (Fn) using fluorescence resonance energy transfer (FRET), we show here that heparin treatment of the fibroblast-derived ECM scaffolds resulted in more extended conformations of fibrillar Fn in ECM. Since heparin is a highly negatively charged molecule while fibronectin contains segments of positively charged modules, including FnIII13, electrostatic interactions between Fn and heparin might interfere with residual quaternary structure in relaxed fibronectin fibers thereby opening up buried sites. The conformation of modules FnIII12-14 in particular, which contain one of the heparin binding sites as well as binding sites for many growth factors, may be activated by heparin, resulting in alterations in growth factor binding to Fn. Indeed, upregulated osteogenic differentiation was observed when hMSCs were seeded on ECM scaffolds that had been treated with heparin and were subsequently chemically fixed. In contrast, either rigidifying relaxed fibers by fixation alone, or heparin treatment without fixation had no effect. We hypothesize that fibronectin's conformations within the ECM are activated by heparin such as to coordinate with other factors to upregulate hMSC osteogenic differentiation. Thus, the conformational changes of fibronectin within the ECM could serve as a 'converter' to tune hMSC differentiation in extracellular matrices. This knowledge could also be exploited to promote osteogenic stem cell differentiation on biomedical surfaces.

Ectomycorrhizal fungal diversity associated with endemic Tristaniopsis spp. (Myrtaceae) in ultramafic and volcano-sedimentary soils in New Caledonia.

PubMed

Waseem, Muhammad; Ducousso, Marc; Prin, Yves; Domergue, Odile; Hannibal, Laure; Majorel, Clarisse; Jourand, Philippe; Galiana, Antoine

2017-05-01

New Caledonian serpentine (ultramafic) soils contain high levels of toxic heavy metals, in particular nickel, (up to 20 g kg -1 ) and are deficient in essential elements like carbon, nitrogen and phosphorus while having a high magnesium/calcium ratio. Although previous studies showed that ectomycorrhizal symbioses could play an important role in the adaptation of the endemic plants to ultramafic soils (FEMS Microbiol Ecol 72:238-49, 2010), none of them have compared the diversity of microbial communities from ultramafic vs non-ultramafic soils in New Caledonia. We explored the impact of edaphic characteristics on the diversity of ectomycorrhizal (ECM) fungi associated with different endemic species of Tristaniopsis (Myrtaceae) growing under contrasting soil conditions in the natural ecosystems of New Caledonia. ECM root tips were thus sampled from two different ultramafic sites (Koniambo massif and Desmazures forest) vs two volcano-sedimentary ones (Arama and Mont Ninndo). The molecular characterization of the ECM fungi through partial sequencing of the ITS rRNA gene revealed the presence of different dominant fungal genera including, both soil types combined, Cortinarius (36.1%), Pisolithus (18.5%), Russula (13.4%), Heliotales (8.2%) and Boletellus (7.2%). A high diversity of ECM taxa associated with Tristaniopsis species was found in both ultramafic and volcano-sedimentary soils but no significant differences in ECM genera distribution were observed between both soil types. No link could be established between the phylogenetic clustering of ECM taxa and their soil type origin, thus suggesting a possible functional-rather than taxonomical-adaptation of ECM fungal communities to ultramafic soils.

Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins

PubMed Central

Jamerson, Melissa; da Rocha-Azevedo, Bruno; Cabral, Guy A.

2012-01-01

Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis. PMID:22222499

Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins.

PubMed

Jamerson, Melissa; da Rocha-Azevedo, Bruno; Cabral, Guy A; Marciano-Cabral, Francine

2012-03-01

Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis.

Accumulation of Extracellular Matrix in Advanced Lesions of Canine Distemper Demyelinating Encephalitis

PubMed Central

Seehusen, Frauke; Al-Azreg, Seham A.; Raddatz, Barbara B.; Haist, Verena; Puff, Christina; Spitzbarth, Ingo; Ulrich, Reiner; Baumgärtner, Wolfgang

2016-01-01

In demyelinating diseases, changes in the quality and quantity of the extracellular matrix (ECM) may contribute to demyelination and failure of myelin repair and axonal sprouting, especially in chronic lesions. To characterize changes in the ECM in canine distemper demyelinating leukoencephalitis (DL), histochemical and immunohistochemical investigations of formalin-fixed paraffin-embedded cerebella using azan, picrosirius red and Gomori`s silver stain as well as antibodies directed against aggrecan, type I and IV collagen, fibronectin, laminin and phosphacan showed alterations of the ECM in CDV-infected dogs. A significantly increased amount of aggrecan was detected in early and late white matter lesions. In addition, the positive signal for collagens I and IV as well as fibronectin was significantly increased in late lesions. Conversely, the expression of phosphacan was significantly decreased in early and more pronounced in late lesions compared to controls. Furthermore, a set of genes involved in ECM was extracted from a publically available microarray data set and was analyzed for differential gene expression. Gene expression of ECM molecules, their biosynthesis pathways, and pro-fibrotic factors was mildly up-regulated whereas expression of matrix remodeling enzymes was up-regulated to a relatively higher extent. Summarized, the observed findings indicate that changes in the quality and content of ECM molecules represent important, mainly post-transcriptional features in advanced canine distemper lesions. Considering the insufficiency of morphological regeneration in chronic distemper lesions, the accumulated ECM seems to play a crucial role upon regenerative processes and may explain the relatively small regenerative potential in late stages of this disease. PMID:27441688

Accumulation of Extracellular Matrix in Advanced Lesions of Canine Distemper Demyelinating Encephalitis.

PubMed

Seehusen, Frauke; Al-Azreg, Seham A; Raddatz, Barbara B; Haist, Verena; Puff, Christina; Spitzbarth, Ingo; Ulrich, Reiner; Baumgärtner, Wolfgang

2016-01-01

In demyelinating diseases, changes in the quality and quantity of the extracellular matrix (ECM) may contribute to demyelination and failure of myelin repair and axonal sprouting, especially in chronic lesions. To characterize changes in the ECM in canine distemper demyelinating leukoencephalitis (DL), histochemical and immunohistochemical investigations of formalin-fixed paraffin-embedded cerebella using azan, picrosirius red and Gomori`s silver stain as well as antibodies directed against aggrecan, type I and IV collagen, fibronectin, laminin and phosphacan showed alterations of the ECM in CDV-infected dogs. A significantly increased amount of aggrecan was detected in early and late white matter lesions. In addition, the positive signal for collagens I and IV as well as fibronectin was significantly increased in late lesions. Conversely, the expression of phosphacan was significantly decreased in early and more pronounced in late lesions compared to controls. Furthermore, a set of genes involved in ECM was extracted from a publically available microarray data set and was analyzed for differential gene expression. Gene expression of ECM molecules, their biosynthesis pathways, and pro-fibrotic factors was mildly up-regulated whereas expression of matrix remodeling enzymes was up-regulated to a relatively higher extent. Summarized, the observed findings indicate that changes in the quality and content of ECM molecules represent important, mainly post-transcriptional features in advanced canine distemper lesions. Considering the insufficiency of morphological regeneration in chronic distemper lesions, the accumulated ECM seems to play a crucial role upon regenerative processes and may explain the relatively small regenerative potential in late stages of this disease.

Ectomycorrhizal fungi reduce the light compensation point and promote carbon fixation of Pinus thunbergii seedlings to adapt to shade environments.

PubMed

Shi, Liang; Wang, Jie; Liu, Binhao; Nara, Kazuhide; Lian, Chunlan; Shen, Zhenguo; Xia, Yan; Chen, Yahua

2017-11-01

We examined the effects of three ectomycorrhizal (ECM) symbionts on the growth and photosynthesis capacity of Japanese black pine (Pinus thunbergii) seedlings and estimated physiological and photosynthetic parameters such as the light compensation point (LCP), biomass, and phosphorus (Pi) concentration of P. thunbergii seedlings. Through this investigation, we documented a new role of ectomycorrhizal (ECM) fungi: enhancement of the survival and competitiveness of P. thunbergii seedlings under low-light condition by reducing the LCP of seedlings. At a CO 2 concentration of 400 ppm, the LCP of seedlings with ECM inoculations was 40-70 μmol photons m -2  s -1 , significantly lower than that of non-mycorrhizal (NM) seedlings (200 μmol photons m -2  s -1 ). In addition, photosynthetic carbon fixation (Pn) increased with light intensity and CO 2 level, and the Pn of ECM seedlings was significantly higher than that of NM seedlings; Pisolithus sp. (Pt)- and Laccaria amethystea (La)-mycorrhizal seedlings had significantly lower Pn than Cenococcum geophilum (Cg)-mycorrhizal seedlings. However, La-mycorrhizal seedlings exhibited the highest fresh weight, relative water content (RWC), and the lowest LCP in the mycorrhizal group. Concomitantly, ECM seedlings showed significantly increased chlorophyll content of needles and higher Pi concentrations compared to NM seedlings. Overall, ECM symbionts promoted growth and photosynthesis while reducing the LCP of P. thunbergii seedlings. These findings indicate that ECM fungi can enhance the survival and competitiveness of host seedlings under low light.

Cell-cell and cell-extracellular matrix adhesions cooperate to organize actomyosin networks and maintain force transmission during dorsal closure.

PubMed

Goodwin, Katharine; Lostchuck, Emily E; Cramb, Kaitlyn M L; Zulueta-Coarasa, Teresa; Fernandez-Gonzalez, Rodrigo; Tanentzapf, Guy

2017-05-15

Tissue morphogenesis relies on the coordinated action of actin networks, cell-cell adhesions, and cell-extracellular matrix (ECM) adhesions. Such coordination can be achieved through cross-talk between cell-cell and cell-ECM adhesions. Drosophila dorsal closure (DC), a morphogenetic process in which an extraembryonic tissue called the amnioserosa contracts and ingresses to close a discontinuity in the dorsal epidermis of the embryo, requires both cell-cell and cell-ECM adhesions. However, whether the functions of these two types of adhesions are coordinated during DC is not known. Here we analyzed possible interdependence between cell-cell and cell-ECM adhesions during DC and its effect on the actomyosin network. We find that loss of cell-ECM adhesion results in aberrant distributions of cadherin-mediated adhesions and actin networks in the amnioserosa and subsequent disruption of myosin recruitment and dynamics. Moreover, loss of cell-cell adhesion caused up-regulation of cell-ECM adhesion, leading to reduced cell deformation and force transmission across amnioserosa cells. Our results show how interdependence between cell-cell and cell-ECM adhesions is important in regulating cell behaviors, force generation, and force transmission critical for tissue morphogenesis. © 2017 Goodwin, Lostchuck, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Thick Acellular Heart Extracellular Matrix with Inherent Vasculature: A Potential Platform for Myocardial Tissue Regeneration

PubMed Central

Sarig, Udi; Au-Yeung, Gigi C.T.; Wang, Yao; Bronshtein, Tomer; Dahan, Nitsan; Boey, Freddy Y.C.; Venkatraman, Subbu S.

2012-01-01

The decellularization of porcine heart tissue offers many opportunities for the production of physiologically relevant myocardial mimetic scaffolds. Earlier, we reported the successful isolation of a thin porcine cardiac extracellular matrix (pcECM) exhibiting relevant bio-mechanical properties for myocardial tissue engineering. Nevertheless, since native cardiac tissue is much thicker, such thin scaffolds may offer limited regeneration capacity. However, generation of thicker myocardial mimetic tissue constructs is hindered by diffusion limitations (∼100 μm), and the lack of a proper vascular-like network within these constructs. In our present work, we focused on optimizing the decellularization procedure for thicker tissue slabs (10–15 mm), while retaining their inherent vasculature, and on characterizing the resulting pcECM. The trypsin/Triton-based perfusion procedure that resulted in a nonimmunogenic and cell-supportive pcECM was found to be more effective in cell removal and in the preservation of fiber morphology and structural characteristics than stirring, sonication, or sodium dodecyl sulfate/Triton-based procedures. Mass spectroscopy revealed that the pcECM is mainly composed of ECM proteins with no apparent cellular protein remains. Mechanical testing indicated that the obtained pcECM is viscoelastic in nature and possesses the typical stress-strain profile of biological materials. It is stiffer than native tissue yet exhibits matched mechanical properties in terms of energy dissipation, toughness, and ultimate stress behavior. Vascular network functionality was maintained to the first three–four branches from the main coronary vessels. Taken together, these results reaffirm the efficiency of the decellularization procedure reported herein for yielding thick nonimmunogenic cell-supportive pcECM scaffolds, preserving both native tissue ultra-structural properties and an inherent vascular network. When reseeded with the appropriate progenitor cells, these scaffolds can potentially serve as ex vivo screening platforms for new therapeutics, as models for human cardiac ECM, or as biomedical constructs for patch or transmural transplantation strategies. PMID:22663095

Effects of Mycorrhizae on Carbon Cycling in Response to Extreme Drought

NASA Astrophysics Data System (ADS)

Ficken, C. D.; Warren, J.

2016-12-01

Plant-mycorrhizal symbioses are being increasingly accepted as drivers of ecosystem-level biogeochemical patterns and play an important role plant resource acquisition. Although some evidence suggests that mycorrhizal association increases plant drought-tolerance, direct comparisons of drought-resilience between mycorrhizal groups (i.e. arbuscular and ectomycorrhizal) are lacking. Indeed, soil CO2 pulses following dry-wet cycles are detectable at the ecosystem scale, but it remains unclear whether these pulses are driven by the activity of mycorrhizae or free-living microbes. These knowledge gaps hinder our ability to predict CO2 fluxes in the face of increased precipitation variability and have broad implications for understanding plant performance during, and recovery following, drought. We predicted that arbuscular mycorrhizae (AM) would be more resilient to drought than ectomycorrhizae (ECM) because narrower AM hyphae may access water from smaller soil pores and because AM produce a glycoprotein that increases soil aggregation. To compare the functioning of AM and ECM throughout drought, we examined soil respiration dynamics between AM- and ECM-dominated mesocosms throughout moderate and extreme drought. Mesocosms were partitioned with mesh dividers into chambers (roots+hyphae+microbes; hyphae+microbes; microbes only) to compare the relative functioning of biotic pools throughout drought. We found that respiration responses to drought differed substantially between AM and ECM-dominated systems. Under dry conditions, respiration from both root- and hyphal-exclusion chambers did not differ between AM and ECM mesocosms. In contrast, under wet conditions, respiration was significantly greater from AM than ECM mesocosms. Following rewetting, the respiration pulse in AM systems was largely due to to free-living microbes (+330% C flux above dry conditions), whereas in ECM systems there was a proportionally greater increase from mycorrhizal chambers (+130%). This suggests, in contrast to our predictions, that ECM fungi are more resilient to drought and are an important driver of C flux following rewetting.

Ectomycorrhizal fungal communities on seedlings and conspecific trees of Pinus mugo grown on the coastal dunes of the Curonian Spit in Lithuania.

PubMed

Aučina, Algis; Rudawska, Maria; Leski, Tomasz; Ryliškis, Darius; Pietras, Marcin; Riepšas, Edvardas

2011-04-01

Ectomycorrhizal (ECM) communities of mature trees and regenerating seedlings of a non-native tree species Pinus mugo grown in a harsh environment of the coastal region of the Curonian Spit National Park in Lithuania were assessed. We established three study sites (S1, S2, and S3) that were separated from each other by 15 km. The ECM species richness was rather low in particular for mature, 100-year-old trees: 12 ectomycorrhizal taxa were identified by molecular analysis from 11 distinguished morphotypes. All 12 taxa were present on seedlings and on mature trees, with between 8-11 and 9-11 taxa present on seedlings and mature trees, respectively. Cenococcum geophilum dominated all ECM communities, but the relative abundance of C. geophilum mycorrhizas was nearly two times higher on seedlings than on mature trees. Mycorrhizal associations formed by Wilcoxina sp., Lactarius rufus, and Russula paludosa were also abundant. Several fungal taxa were only occasionally detected, including Cortinarius sp., Cortinarius obtusus, Cortinarius croceus, and Meliniomyces sp. Shannon's diversity indices for the ECM assemblages of P. mugo ranged from 0.98 to 1.09 for seedling and from 1.05 to 1.31 for mature trees. According to analysis of similarity, the mycorrhizal communities were similar between the sites (R = 0.085; P = 0.06) and only slightly separated between seedlings and mature trees (R = 0.24; P < 0.0001). An incidental fruiting body survey that was conducted weakly reflected the below-ground assessment of the ECM fungal community and once again showed that ECM and fruiting body studies commonly supply different partial accounts of the true ECM fungal diversity. Our results show that P. mugo has moved into quite distinct habitats and is able to adapt a suite of ECM symbionts that sufficiently support growth and development of this tree and allow for natural seedling regeneration.

Metabolomics revealed an association of metabolite changes and defective growth in Methylobacterium extorquens AM1 overexpressing ecm during growth on methanol

DOE PAGES

Cui, Jinyu; Good, Nathan M.; Hu, Bo; ...

2016-04-26

Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multi-carbon compounds. The ethylmalonyl-CoA (EMC) pathway is one of the central assimilatory pathways in M. extorquens during growth on C1 and C2 substrates. Previous studies had shown that ethylmalonyl-CoA mutase functioned as a control point during the transition from growth on succinate to growth on ethylamine. In this study we overexpressed ecm, phaA, mcmAB and found that upregulating ecm by expressing it from the strong constitutive mxaF promoter caused a 27% decrease in growth rate on methanol compared to the strain with an empty vector. Targetedmore » metabolomics demonstrated that most of the central intermediates in the ecm over-expressing strain did not change significantly compared to the control strain; However, poly-β-hydroxybutyrate (PHB) was 4.5-fold lower and 3-hydroxybutyryl-CoA was 1.6-fold higher. Moreover, glyoxylate, a toxic and highly regulated essential intermediate, was determined to be 2.6-fold higher when ecm was overexpressed. These results demonstrated that overexpressing ecm can manipulate carbon flux through the EMC pathway and divert it from the carbon and energy storage product PHB, leading to an accumulation of glyoxylate. Furthermore, untargeted metabolomics discovered two unusual metabolites, alanine (Ala)-meso-diaminopimelic acid (mDAP) and Ala-mDAP-Ala, each over 45-fold higher in the ecm overexpressing strain. These two peptides were also found to be highly produced in a dose-dependent manner when glyoxylate was added to the control strain. Overall, this work has explained a direct association of ecm overexpression with glyoxylate accumulation up to a toxic level, which inhibits cell growth on methanol. Lastly, this research provides useful insight for manipulating the EMC pathway for efficiently producing high-value chemicals in M. extorquens.« less

Metabolomics revealed an association of metabolite changes and defective growth in Methylobacterium extorquens AM1 overexpressing ecm during growth on methanol

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

Cui, Jinyu; Good, Nathan M.; Hu, Bo

Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multi-carbon compounds. The ethylmalonyl-CoA (EMC) pathway is one of the central assimilatory pathways in M. extorquens during growth on C1 and C2 substrates. Previous studies had shown that ethylmalonyl-CoA mutase functioned as a control point during the transition from growth on succinate to growth on ethylamine. In this study we overexpressed ecm, phaA, mcmAB and found that upregulating ecm by expressing it from the strong constitutive mxaF promoter caused a 27% decrease in growth rate on methanol compared to the strain with an empty vector. Targetedmore » metabolomics demonstrated that most of the central intermediates in the ecm over-expressing strain did not change significantly compared to the control strain; However, poly-β-hydroxybutyrate (PHB) was 4.5-fold lower and 3-hydroxybutyryl-CoA was 1.6-fold higher. Moreover, glyoxylate, a toxic and highly regulated essential intermediate, was determined to be 2.6-fold higher when ecm was overexpressed. These results demonstrated that overexpressing ecm can manipulate carbon flux through the EMC pathway and divert it from the carbon and energy storage product PHB, leading to an accumulation of glyoxylate. Furthermore, untargeted metabolomics discovered two unusual metabolites, alanine (Ala)-meso-diaminopimelic acid (mDAP) and Ala-mDAP-Ala, each over 45-fold higher in the ecm overexpressing strain. These two peptides were also found to be highly produced in a dose-dependent manner when glyoxylate was added to the control strain. Overall, this work has explained a direct association of ecm overexpression with glyoxylate accumulation up to a toxic level, which inhibits cell growth on methanol. Lastly, this research provides useful insight for manipulating the EMC pathway for efficiently producing high-value chemicals in M. extorquens.« less

Spatial Anisotropies and Temporal Fluctuations in Extracellular Matrix Network Texture during Early Embryogenesis

PubMed Central

Loganathan, Rajprasad; Potetz, Brian R.; Rongish, Brenda J.; Little, Charles D.

2012-01-01

Early stages of vertebrate embryogenesis are characterized by a remarkable series of shape changes. The resulting morphological complexity is driven by molecular, cellular, and tissue-scale biophysical alterations. Operating at the cellular level, extracellular matrix (ECM) networks facilitate cell motility. At the tissue level, ECM networks provide material properties required to accommodate the large-scale deformations and forces that shape amniote embryos. In other words, the primordial biomaterial from which reptilian, avian, and mammalian embryos are molded is a dynamic composite comprised of cells and ECM. Despite its central importance during early morphogenesis we know little about the intrinsic micrometer-scale surface properties of primordial ECM networks. Here we computed, using avian embryos, five textural properties of fluorescently tagged ECM networks — (a) inertia, (b) correlation, (c) uniformity, (d) homogeneity, and (e) entropy. We analyzed fibronectin and fibrillin-2 as examples of fibrous ECM constituents. Our quantitative data demonstrated differences in the surface texture between the fibronectin and fibrillin-2 network in Day 1 (gastrulating) embryos, with the fibronectin network being relatively coarse compared to the fibrillin-2 network. Stage-specific regional anisotropy in fibronectin texture was also discovered. Relatively smooth fibronectin texture was exhibited in medial regions adjoining the primitive streak (PS) compared with the fibronectin network investing the lateral plate mesoderm (LPM), at embryonic stage 5. However, the texture differences had changed by embryonic stage 6, with the LPM fibronectin network exhibiting a relatively smooth texture compared with the medial PS-oriented network. Our data identify, and partially characterize, stage-specific regional anisotropy of fibronectin texture within tissues of a warm-blooded embryo. The data suggest that changes in ECM textural properties reflect orderly time-dependent rearrangements of a primordial biomaterial. We conclude that the ECM microenvironment changes markedly in time and space during the most important period of amniote morphogenesis—as determined by fluctuating textural properties. PMID:22693609

Direct Measurement of Intracellular Pressure

PubMed Central

Petrie, Ryan J.; Koo, Hyun

2014-01-01

A method to directly measure the intracellular pressure of adherent, migrating cells is described in the Basic Protocol. This approach is based on the servo-null method where a microelectrode is introduced into the cell to directly measure the physical pressure of the cytoplasm. We also describe the initial calibration of the microelectrode as well as the application of the method to cells migrating inside three-dimensional (3D) extracellular matrix (ECM). PMID:24894836

Proteomic Analysis of Pathogenic Fungi Reveals Highly Expressed Conserved Cell Wall Proteins

PubMed Central

Champer, Jackson; Ito, James I.; Clemons, Karl V.; Stevens, David A.; Kalkum, Markus

2016-01-01

We are presenting a quantitative proteomics tally of the most commonly expressed conserved fungal proteins of the cytosol, the cell wall, and the secretome. It was our goal to identify fungi-typical proteins that do not share significant homology with human proteins. Such fungal proteins are of interest to the development of vaccines or drug targets. Protein samples were derived from 13 fungal species, cultured in rich or in minimal media; these included clinical isolates of Aspergillus, Candida, Mucor, Cryptococcus, and Coccidioides species. Proteomes were analyzed by quantitative MSE (Mass Spectrometry—Elevated Collision Energy). Several thousand proteins were identified and quantified in total across all fractions and culture conditions. The 42 most abundant proteins identified in fungal cell walls or supernatants shared no to very little homology with human proteins. In contrast, all but five of the 50 most abundant cytosolic proteins had human homologs with sequence identity averaging 59%. Proteomic comparisons of the secreted or surface localized fungal proteins highlighted conserved homologs of the Aspergillus fumigatus proteins 1,3-β-glucanosyltransferases (Bgt1, Gel1-4), Crf1, Ecm33, EglC, and others. The fact that Crf1 and Gel1 were previously shown to be promising vaccine candidates, underlines the value of the proteomics data presented here. PMID:26878023

Evaluating Aircrew and Maintainer Warfighter Performance in Aeronautical Systems using Mission-Oriented Measures of Effectiveness

DTIC Science & Technology

2001-02-01

ECM Electronic Countermeasures EEG Electroencephalograph EKG Electrocardiogram EPA Extended Planning Annex EPF Equipment Performance Factor...related physiological measures Changes in the brain/neural system caused by workload. Rehmann, 1995, p. 12 M 8.2.16 Electroencephalograph ( EEG ...architecture TMD Operational Objectives: Destroy Theater Missiles ( TM ) and their infrastructure as far forward as possible (Attack Operations

2-photon laser scanning microscopy on native human cartilage

NASA Astrophysics Data System (ADS)

Martini, Joerg; Toensing, Katja; Dickob, Michael; Anselmetti, Dario

2005-08-01

Native hyaline cartilage from a human knee joint was directly investigated with laser scanning microscopy via 2-photon autofluorescence excitation with no additional staining or labelling protocols in a nondestructive and sterile manner. Using a femtosecond, near-infrared (NIR) Ti:Sa laser for 2-photon excitation and a dedicated NIR long distance objective, autofluorescence imaging and measurements of the extracellular matrix (ECM) tissue with incorporated chondrocytes were possible with a penetration depth of up to 460 μm inside the sample. Via spectral autofluorescence separation these experiments allowed the discrimination of chondrocytes from the ECM and therefore an estimate of chondrocytic cell density within the cartilage tissue to approximately 0.2-2•107cm3. Furthermore, a comparison of the relative autofluorescence signals between nonarthritic and arthritic cartilage tissue exhibited distinct differences in tissue morphology. As these morphological findings are in keeping with the macroscopic diagnosis, our measurement has the potential of being used in future diagnostic applications.

Methods of Manufacturing Bioactive Gels from Extracellular Matrix Material

NASA Technical Reports Server (NTRS)

Janis, Abram D. (Inventor); Kentner, Kimberly A. (Inventor); Stuart, Katherine A. (Inventor)

2014-01-01

The present invention is directed to methods of manufacturing bioactive gels from ECM material, i.e., gels which retain bioactivity, and can serve as scaffolds for preclinical and clinical tissue engineering and regenerative medicine approaches to tissue reconstruction. The manufacturing methods take advantage of a new recognition that bioactive gels from ECM material can be created by digesting particularized ECM material in an alkaline environment and neutralizing to provide bioactive gels.

Methods of Manufacturing Bioactive Gels from Extracellular Matrix Material

NASA Technical Reports Server (NTRS)

Kentner, Kimberly A. (Inventor); Stuart, Katherine A. (Inventor); Janis, Abram D. (Inventor)

2015-01-01

The present invention is directed to methods of manufacturing bioactive gels from ECM material, i.e., gels which retain bioactivity, and can serve as scaffolds for preclinical and clinical tissue engineering and regenerative medicine approaches to tissue reconstruction. The manufacturing methods take advantage of a new recognition that bioactive gels from ECM material can be created by digesting particularized ECM material in an alkaline environment and neutralizing to provide bioactive gels.

Methods of Manufacturing Bioactive Gels from Extracellular Matrix Material

NASA Technical Reports Server (NTRS)

Kentner, Kimberly A. (Inventor); Stuart, Katherine A. (Inventor); Janis, Abram D. (Inventor)

2016-01-01

The present invention is directed to methods of manufacturing bioactive gels from ECM material, i.e., gels which retain bioactivity, and can serve as scaffolds for preclinical and clinical tissue engineering and regenerative medicine approaches to tissue reconstruction. The manufacturing methods take advantage of a new recognition that bioactive gels from ECM material can be created by digesting particularized ECM material in an alkaline environment and neutralizing to provide bioactive gels.

Methods of Manufacturing Bioactive Gels from Extracellular Matrix Material

NASA Technical Reports Server (NTRS)

Kentner, Kimberly (Inventor); Janis, Abram D. (Inventor); Stuart, Katherine A. (Inventor)

2017-01-01

The present invention is directed to methods of manufacturing bioactive gels from ECM material, i.e., gels which retain bioactivity, and can serve as scaffolds for preclinical and clinical tissue engineering and regenerative medicine approaches to tissue reconstruction. The manufacturing methods take advantage of a new recognition that bioactive gels from ECM material can be created by digesting particularized ECM material in an alkaline environment and neutralizing to provide bioactive gels.

ECM remodeling and its plasticity

NASA Astrophysics Data System (ADS)

Feng, Jingchen; Jones, Christopher A. R.; Cibula, Matthew; Mao, Xiaoming; Sander, Leonard M.; Levine, Herbert; Sun, Bo

The mechanical interactions between cells and Extracellular Matrix (ECM) are of great importance in many cellular processes. These interactions are reciprocal, i.e. contracting cells pull and reorganize the surrounding matrix, while the remodeled matrix feeds back to regulate cell activities. Recent experiments show in collagen gels with densely distributed cells, aligned fiber bundles are formed in the direction between neighboring cells. Fibers flow into the center region between contracting cell pairs in this process, which causes the concentration of fibers in the fiber bundles to become significantly enhanced. Using an extended lattice-based model, we show that viscoelasticity plays an essential role in ECM remodeling and contributes to the enhanced concentration in fiber bundles. We further characterize ECM plasticity within our model and verify our results with rheometer experiments.

Contractile forces originating from Cancer Diskiod regulated by geometrical ECM properties

NASA Astrophysics Data System (ADS)

Alobaidi, Amani; Sun, Bo

Cancer cell migration in three-dimensional extracellular matrix is a major cause of death for cancer patients. Although extensive studies have enlightened detailed mechanism of single cell 3D invasion and cell-ECM interaction, 3D collective cancer invasion is still poorly understood. To capture collective cancer invasion with more realistic, we developed a novel 3D invasion assay, Diskiod In Geometrically Micropatterned ECM (DIGME). DIGME allows us to independently controlling the shape the shape of tumor organoids, microstructure and spatial heterogeneity of the extracellular matrix all at the same time. Here we study the affect of contractile forces originating from different geometrical cancer diskiods. We show that cancer invasion could be regulated by geometrical ECM properties.

Role of the extracellular matrix during neural crest cell migration.

PubMed

Perris, R; Perissinotto, D

2000-07-01

Once specified to become neural crest (NC), cells occupying the dorsal portion of the neural tube disrupt their cadherin-mediated cell-cell contacts, acquire motile properties, and embark upon an extensive migration through the embryo to reach their ultimate phenotype-specific sites. The understanding of how this movement is regulated is still rather fragmentary due to the complexity of the cellular and molecular interactions involved. An additional intricate aspect of the regulation of NC cell movement is that the timings, modes and patterns of NC cell migration are intimately associated with the concomitant phenotypic diversification that cells undergo during their migratory phase and the fact that these changes modulate the way that moving cells interact with their microenvironment. To date, two interplaying mechanisms appear central for the guidance of the migrating NC cells through the embryo: one involves secreted signalling molecules acting through their cognate protein kinase/phosphatase-type receptors and the other is contributed by the multivalent interactions of the cells with their surrounding extracellular matrix (ECM). The latter ones seem fundamental in light of the central morphogenetic role played by the intracellular signals transduced through the cytoskeleton upon integrin ligation, and the convergence of these signalling cascades with those triggered by cadherins, survival/growth factor receptors, gap junctional communications, and stretch-activated calcium channels. The elucidation of the importance of the ECM during NC cell movement is presently favoured by the augmenting knowledge about the macromolecular structure of the specific ECM assembled during NC development and the functional assaying of its individual constituents via molecular and genetic manipulations. Collectively, these data propose that NC cell migration may be governed by time- and space-dependent alterations in the expression of inhibitory ECM components; the relative ratio of permissive versus non-permissive ECM components; and the supramolecular assembly of permissive ECM components. Six multidomain ECM constituents encoded by a corresponding number of genes appear to date the master ECM molecules in the control of NC cell movement. These are fibronectin, laminin isoforms 1 and 8, aggrecan, and PG-M/version isoforms V0 and V1. This review revisits a number of original observations in amphibian and avian embryos and discusses them in light of more recent experimental data to explain how the interaction of moving NC cells with these ECM components may be coordinated to guide cells toward their final sites during the process of organogenesis.

Updated (BP3) Technical and Economic Feasibility Study - Electrochemical Membrane for Carbon Dioxide Capture and Power Generation

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

Ghezel-Ayagh, Hossein

This topical report summarizes the results of an updated Technical & Economic Feasibility Study (T&EFS) which was conducted in Budget Period 3 of the project to evaluate the performance and cost of the Electrochemical Membrane (ECM)-based CO 2 capture system. The ECM technology is derived from commercially available inorganic membranes; the same used in FuelCell Energy’s commercial fuel cell power plants and sold under the trade name Direct FuelCell® (DFC®). The ECM stacks are utilized in the Combined Electric Power (generation) And Carbon dioxide Separation (CEPACS) systems which can be deployed as add-ons to conventional power plants (Pulverized Coal, Combinedmore » Cycle, etc.) or industrial facilities to simultaneously produce power while capturing >90% of the CO 2 from the flue gas. In this study, an ECM-based CEPACS plant was designed to capture and compress >90% of the CO 2 (for sequestration or beneficial use) from the flue gas of a reference 550 MW (nominal, net AC) Pulverized Coal (PC) Rankine Cycle (Subcritical steam) power plant. ECM performance was updated based on bench scale ECM stack test results. The system process simulations were performed to generate the CEPACS plant performance estimates. The performance assessment included estimation of the parasitic power consumption for CO 2 capture and compression, and the efficiency impact on the PC plant. While the ECM-based CEPACS system for the 550 MW PC plant captures 90% of CO 2 from the flue gas, it generates additional (net AC) power after compensating for the auxiliary power requirements of CO 2 capture and compression. An equipment list, ECM stacks packaging design, and CEPACS plant layout were developed to facilitate the economic analysis. Vendor quotes were also solicited. The economic feasibility study included estimation of CEPACS plant capital cost, cost of electricity (COE) analyses and estimation of cost per ton of CO 2 captured. The incremental COE for the ECM-based CO 2 capture is expected to meet U.S. DOE’s target of 35%. This study has indicated that CEPACS systems offer significant benefits with respect to cost, performance, water consumption and emissions to environment. The realization of these benefits will provide a single solution to carbon dioxide capture in addition to meeting the increasing demand for electricity.« less

Updated (BP3) Technical and Economic Feasibility Study - Electrochemical Membrane for Carbon Dioxide Capture and Power Generation

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

Ghezel-Ayagh, Hossein

This topical report summarizes the results of an updated Technical & Economic Feasibility Study (T&EFS) which was conducted in Budget Period 3 of the project to evaluate the performance and cost of the Electrochemical Membrane (ECM)-based CO2 capture system. The ECM technology is derived from commercially available inorganic membranes; the same used in FuelCell Energy’s commercial fuel cell power plants and sold under the trade name Direct FuelCell® (DFC®). The ECM stacks are utilized in the Combined Electric Power (generation) And Carbon dioxide Separation (CEPACS) systems which can be deployed as add-ons to conventional power plants (Pulverized Coal, Combined Cycle,more » etc.) or industrial facilities to simultaneously produce power while capturing >90% of the CO2 from the flue gas. In this study, an ECM-based CEPACS plant was designed to capture and compress >90% of the CO2 (for sequestration or beneficial use) from the flue gas of a reference 550 MW (nominal, net AC) Pulverized Coal (PC) Rankine Cycle (Subcritical steam) power plant. ECM performance was updated based on bench scale ECM stack test results. The system process simulations were performed to generate the CEPACS plant performance estimates. The performance assessment included estimation of the parasitic power consumption for CO2 capture and compression, and the efficiency impact on the PC plant. While the ECM-based CEPACS system for the 550 MW PC plant captures 90% of CO2 from the flue gas, it generates additional (net AC) power after compensating for the auxiliary power requirements of CO2 capture and compression. An equipment list, ECM stacks packaging design, and CEPACS plant layout were developed to facilitate the economic analysis. Vendor quotes were also solicited. The economic feasibility study included estimation of CEPACS plant capital cost, cost of electricity (COE) analyses and estimation of cost per ton of CO2 captured. The incremental COE for the ECM-based CO2 capture is expected to meet U.S. DOE’s target of 35%. This study has indicated that CEPACS systems offer significant benefits with respect to cost, performance, water consumption and emissions to environment. The realization of these benefits will provide a single solution to carbon dioxide capture in addition to meeting the increasing demand for electricity.« less

Estimates of carbon allocation to ectomycorrhizal fungi in a temperate forest

NASA Astrophysics Data System (ADS)

Ouimette, A.; Ollinger, S. V.; Vadeboncoeur, M. A.; Hobbie, E. A.

2012-12-01

The capacity of temperate and boreal forests to grow and sequester carbon (C) is limited by the amount of available nitrogen (N) in soils. While the importance of N to carbon storage is well known, we lack a thorough understanding of the mechanisms of N acquisition and the belowground carbon investment required for trees to compete for N. Resolving these uncertainties is critical for predicting future carbon budgets, given expected changes in climate, N deposition, atmospheric CO2, and tree species distribution. Some of the greatest uncertainties surrounding belowground C-N interactions involve the symbiotic fungi that serve as an interface between trees and various forms of N they acquire. Nearly all temperate and boreal forest trees have associations with one of two types of fungi: ectomycorrhizal (ECM) or arbuscular mycorrhizal (AM) fungi. Both types of fungi provide trees with soil nitrogen and other nutrients necessary for growth and in return receive carbon (sugars) from trees. Understanding the differences between these fungal groups is important because they differ dramatically in their carbon requirements and in their ability to access different forms of N. ECM fungi have higher carbon demand, more extensive hyphae (fungal roots), and much stronger capabilities to break down soil organic matter than AM fungi. Despite their importance in the terrestrial C cycle, mycorrhizal fungi are distinctly absent from forest ecosystem C and N models, primarily due to a lack of quantitative data on carbon allocation to mycorrhizal fungi in forests. Quantifying carbon allocation to mycorrhizal fungi is inherently difficult given their small (microscopic) size and lack of specific quantitative biomarkers. Here we present simple measurements that make use of natural abundance N stable isotope data (δ15N) of plant and soil pools, as well as forest C and N budget data, to provide estimates of C allocation to ECM fungi across temperate forest stands with a range of soil N availabilities and species composition. Results show that the fraction of NPP allocated to ECM fungi is related to soil N availability and tree functional type (coniferous vs. broadleaf). These estimates of C allocation will help parameterize ecosystem models to specifically include ECM fungi.

Inhibitory effect of ginsenoside Rg1 on extracellular matrix production via extracellular signal-regulated protein kinase/activator protein 1 pathway in nasal polyp-derived fibroblasts.

PubMed

Cho, Jung-Sun; Moon, You-Mi; Um, Ji-Young; Moon, Jun-Hyeok; Park, Il-Ho; Lee, Heung-Man

2012-06-01

Nasal polyps are associated with chronic inflammation of the sinonasal mucosa and are involved in myofibroblast differentiation and extracellular matrix (ECM) accumulation. Ginsenoside Rg1, a compound derived from Panax ginseng, shows antifibrotic and anticancer effects. However, the molecular effects of Rg1 on myofibroblast differentiation and ECM production remain unknown. The aims of this study were to investigate the effect of Rg1 on transforming growth factor (TGF)-β1-induced myofibroblast differentiation and ECM production and to determine the molecular mechanism of Rg1 in nasal polyp-derived fibroblasts (NPDFs). NPDFs were isolated from nasal polyps of seven patients who had chronic rhinosinusitis with nasal polyp. NPDFs were exposed to TGF-β1 with or without Rg1. Expression levels of α-smooth muscle actin (SMA), fibronectin and collagen type Iα1 were determined by reverse transcription polymerase chain reaction, Western blot and immunofluorescent staining. TGF-β1 signaling molecules, including Smad2/3, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 were analyzed by Western blotting. Transcription factors involved with TGF-β1 signaling, nuclear factor (NF)-κB and activator protein 1 (AP-1) were also assessed by Western blot. The cytotoxic effect of Rg1 was measured by an established viability assay. The mRNA and protein expression levels of α-SMA, fibronectin and collagen type Iα1 were increased in TGF-β1-induced NPDFs. Rg1 inhibited these effects. The inhibitory molecular mechanism of Rg1 was involved in the ERK pathway. Rg1 inhibited the transcription factor activation of AP-1. Rg1 itself was not cytotoxic. The ginsenoside Rg1 has inhibitory effects on myofibroblast differentiation and ECM production. The inhibitory mechanism of Rg1 is involved with the ERK and AP-1 signaling pathways. Rg1 may be useful as an inhibitor of ECM deposition, and has potential to be used as a novel treatment option for nasal polyps.

Extracellular matrix controls tubulin monomer levels in hepatocytes by regulating protein turnover

NASA Technical Reports Server (NTRS)

Mooney, D. J.; Hansen, L. K.; Langer, R.; Vacanti, J. P.; Ingber, D. E.

1994-01-01

Cells have evolved an autoregulatory mechanism to dampen variations in the concentration of tubulin monomer that is available to polymerize into microtubules (MTs), a process that is known as tubulin autoregulation. However, thermodynamic analysis of MT polymerization predicts that the concentration of free tubulin monomer must vary if MTs are to remain stable under different mechanical loads that result from changes in cell adhesion to the extracellular matrix (ECM). To determine how these seemingly contradictory regulatory mechanisms coexist in cells, we measured changes in the masses of tubulin monomer and polymer that resulted from altering cell-ECM contacts. Primary rat hepatocytes were cultured in chemically defined medium on bacteriological petri dishes that were precoated with different densities of laminin (LM). Increasing the LM density from low to high (1-1000 ng/cm2), promoted cell spreading (average projected cell area increased from 1200 to 6000 microns2) and resulted in formation of a greatly extended MT network. Nevertheless, the steady-state mass of tubulin polymer was similar at 48 h, regardless of cell shape or ECM density. In contrast, round hepatocytes on low LM contained a threefold higher mass of tubulin monomer when compared with spread cells on high LM. Furthermore, similar results were obtained whether LM, fibronectin, or type I collagen were used for cell attachment. Tubulin autoregulation appeared to function normally in these cells because tubulin mRNA levels and protein synthetic rates were greatly depressed in round cells that contained the highest level of free tubulin monomer. However, the rate of tubulin protein degradation slowed, causing the tubulin half-life to increase from approximately 24 to 55 h as the LM density was lowered from high to low and cell rounding was promoted. These results indicate that the set-point for the tubulin monomer mass in hepatocytes can be regulated by altering the density of ECM contacts and changing cell shape. This finding is consistent with a mechanism of MT regulation in which the ECM stabilizes MTs by both accepting transfer of mechanical loads and altering tubulin degradation in cells that continue to autoregulate tubulin synthesis.

Extracellular Matrix Plasticity and GABAergic Inhibition of Prefrontal Cortex Pyramidal Cells Facilitates Relapse to Heroin Seeking

PubMed Central

Van den Oever, Michel C; Lubbers, Bart R; Goriounova, Natalia A; Li, Ka W; Van der Schors, Roel C; Loos, Maarten; Riga, Danai; Wiskerke, Joost; Binnekade, Rob; Stegeman, M; Schoffelmeer, Anton N M; Mansvelder, Huibert D; Smit, August B; De Vries, Taco J; Spijker, Sabine

2010-01-01

Successful treatment of drug addiction is hampered by high relapse rates during periods of abstinence. Neuroadaptation in the medial prefrontal cortex (mPFC) is thought to have a crucial role in vulnerability to relapse to drug seeking, but the molecular and cellular mechanisms remain largely unknown. To identify protein changes that contribute to relapse susceptibility, we investigated synaptic membrane fractions from the mPFC of rats that underwent 21 days of forced abstinence following heroin self-administration. Quantitative proteomics revealed that long-term abstinence from heroin self-administration was associated with reduced levels of extracellular matrix (ECM) proteins. After extinction of heroin self-administration, downregulation of ECM proteins was also present in the mPFC, as well as nucleus accumbens (NAc), and these adaptations were partially restored following cue-induced reinstatement of heroin seeking. In the mPFC, these ECM proteins are condensed in the perineuronal nets that exclusively surround GABAergic interneurons, indicating that ECM adaptation might alter the activity of GABAergic interneurons. In support of this, we observed an increase in the inhibitory GABAergic synaptic inputs received by the mPFC pyramidal cells after the re-exposure to heroin-conditioned cues. Recovering levels of ECM constituents by metalloproteinase inhibitor treatment (FN-439; i.c.v.) prior to a reinstatement test attenuated subsequent heroin seeking, suggesting that the reduced synaptic ECM levels during heroin abstinence enhanced sensitivity to respond to heroin-conditioned cues. We provide evidence for a novel neuroadaptive mechanism, in which heroin self-administration-induced adaptation of the ECM increased relapse vulnerability, potentially by augmenting the responsivity of mPFC GABAergic interneurons to heroin-associated stimuli. PMID:20592718

Associated genetic syndromes and extracardiac malformations strongly influence outcomes of fetuses with congenital heart diseases.

PubMed

Bensemlali, Myriam; Bajolle, Fanny; Ladouceur, Magalie; Fermont, Laurent; Lévy, Marilyne; Le Bidois, Jérôme; Salomon, Laurent J; Bonnet, Damien

2016-05-01

Congenital heart disease (CHD) is often associated with extracardiac malformations (ECMs) and genetic syndromes. To determine the effect of cytogenetic anomalies and/or ECMs associated with CHD on parental decision to choose termination of pregnancy (TOP) or compassionate care (CC), as well as on the outcome of children born alive. This 10-year retrospective study included all prenatally diagnosed cases of CHD in a single tertiary referral centre. From January 2002 to December 2011, 2036 consecutive cases of fetal CHD (798 TOPs and 1238 live births, including 59 with postnatal CC) were included. CHD was associated with a known cytogenetic anomaly in 9.8% of cases and a major ECM in 11.7% of cases. The proportion of prenatally identified associated cytogenetic anomalies was significantly lower in the live-birth group than in the TOP plus CC group (4.2% vs 17.5%; P<0.001); this was also true for ECMs (8.1% vs 16.7%; P<0.001). The mortality rate was higher in the group with an associated cytogenetic anomaly or ECM (29.1%) than in cases with isolated CHD; a 2.4-fold increase in the death rate was observed (95% confidence interval 1.34-4.38; P=0.003). These associations remained significant after multivariable analysis, including the severity of the CHD (uni- or biventricular physiology). Prenatal diagnosis of a known cytogenetic anomaly or major ECM strongly influences parental decision to choose TOP or postnatal CC. Genetic syndromes and ECMs are associated with a higher mortality rate, independent of the complexity of the CHD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Teaching the extracellular matrix and introducing online databases within a multidisciplinary course with i-cell-MATRIX: A student-centered approach.

PubMed

Sousa, João Carlos; Costa, Manuel João; Palha, Joana Almeida

2010-03-01

The biochemistry and molecular biology of the extracellular matrix (ECM) is difficult to convey to students in a classroom setting in ways that capture their interest. The understanding of the matrix's roles in physiological and pathological conditions study will presumably be hampered by insufficient knowledge of its molecular structure. Internet-available resources can bridge the division between the molecular details and ECM's biological properties and associated processes. This article presents an approach to teach the ECM developed for first year medical undergraduates who, working in teams: (i) Explore a specific molecular component of the matrix, (ii) identify a disease in which the component is implicated, (iii) investigate how the component's structure/function contributes to ECM' supramolecular organization in physiological and in pathological conditions, and (iv) share their findings with colleagues. The approach-designated i-cell-MATRIX-is focused on the contribution of individual components to the overall organization and biological functions of the ECM. i-cell-MATRIX is student centered and uses 5 hours of class time. Summary of results and take home message: A "1-minute paper" has been used to gather student feedback on the impact of i-cell-MATRIX. Qualitative analysis of student feedback gathered in three consecutive years revealed that students appreciate the approach's reliance on self-directed learning, the interactivity embedded and the demand for deeper insights on the ECM. Learning how to use internet biomedical resources is another positive outcome. Ninety percent of students recommend the activity for subsequent years. i-cell-MATRIX is adaptable by other medical schools which may be looking for an approach that achieves higher student engagement with the ECM. Copyright © 2010 International Union of Biochemistry and Molecular Biology, Inc.

Regulation of ecmF gene expression and genetic hierarchy among STATa, CudA, and MybC on several prestalk A-specific gene expressions in Dictyostelium.

PubMed

Saga, Yukika; Inamura, Tomoka; Shimada, Nao; Kawata, Takefumi

2016-05-01

STATa, a Dictyostelium homologue of metazoan signal transducer and activator of transcription, is important for the organizer function in the tip region of the migrating Dictyostelium slug. We previously showed that ecmF gene expression depends on STATa in prestalk A (pstA) cells, where STATa is activated. Deletion and site-directed mutagenesis analysis of the ecmF/lacZ fusion gene in wild-type and STATa null strains identified an imperfect inverted repeat sequence, ACAAATANTATTTGT, as a STATa-responsive element. An upstream sequence element was required for efficient expression in the rear region of pstA zone; an element downstream of the inverted repeat was necessary for sufficient prestalk expression during culmination. Band shift analyses using purified STATa protein detected no sequence-specific binding to those ecmF elements. The only verified upregulated target gene of STATa is cudA gene; CudA directly activates expL7 gene expression in prestalk cells. However, ecmF gene expression was almost unaffected in a cudA null mutant. Several previously reported putative STATa target genes were also expressed in cudA null mutant but were downregulated in STATa null mutant. Moreover, mybC, which encodes another transcription factor, belonged to this category, and ecmF expression was downregulated in a mybC null mutant. These findings demonstrate the existence of a genetic hierarchy for pstA-specific genes, which can be classified into two distinct STATa downstream pathways, CudA dependent and independent. The ecmF expression is indirectly upregulated by STATa in a CudA-independent activation manner but dependent on MybC, whose expression is positively regulated by STATa. © 2016 Japanese Society of Developmental Biologists.

Escherichia coli biofilms have an organized and complex extracellular matrix structure.

PubMed

Hung, Chia; Zhou, Yizhou; Pinkner, Jerome S; Dodson, Karen W; Crowley, Jan R; Heuser, John; Chapman, Matthew R; Hadjifrangiskou, Maria; Henderson, Jeffrey P; Hultgren, Scott J

2013-09-10

Bacterial biofilms are ubiquitous in nature, and their resilience is derived in part from a complex extracellular matrix that can be tailored to meet environmental demands. Although common developmental stages leading to biofilm formation have been described, how the extracellular components are organized to allow three-dimensional biofilm development is not well understood. Here we show that uropathogenic Escherichia coli (UPEC) strains produce a biofilm with a highly ordered and complex extracellular matrix (ECM). We used electron microscopy (EM) techniques to image floating biofilms (pellicles) formed by UPEC. EM revealed intricately constructed substructures within the ECM that encase individual, spatially segregated bacteria with a distinctive morphology. Mutational and biochemical analyses of these biofilms confirmed curli as a major matrix component and revealed important roles for cellulose, flagella, and type 1 pili in pellicle integrity and ECM infrastructure. Collectively, the findings of this study elucidated that UPEC pellicles have a highly organized ultrastructure that varies spatially across the multicellular community. Bacteria can form biofilms in diverse niches, including abiotic surfaces, living cells, and at the air-liquid interface of liquid media. Encasing these cellular communities is a self-produced extracellular matrix (ECM) that can be composed of proteins, polysaccharides, and nucleic acids. The ECM protects biofilm bacteria from environmental insults and also makes the dissolution of biofilms very challenging. As a result, formation of biofilms within humans (during infection) or on industrial material (such as water pipes) has detrimental and costly effects. In order to combat bacterial biofilms, a better understanding of components required for biofilm formation and the ECM is required. This study defined the ECM composition and architecture of floating pellicle biofilms formed by Escherichia coli.

The architecture of Norway spruce ectomycorrhizae: three-dimensional models of cortical cells, fungal biomass, and interface for potential nutrient exchange.

PubMed

Stögmann, Bernhard; Marth, Andreas; Pernfuß, Barbara; Pöder, Reinhold

2013-08-01

Gathering realistic data on actual fungal biomass in ectomycorrhized fine root systems is still a matter of concern. Thus far, observations on architecture of ectomycorrhizae (ECMs) have been limited to analyses of two-dimensional (2-D) images of tissue sections. This unavoidably causes stereometrical problems that lead to inadequate assumptions about actual size of cells and their arrangement within ECM's functional compartments. Based on extensive morphological investigations of field samples, we modeled the architectural components of an average-sized Norway spruce ECM. In addition to our comprehensive and detailed quantitative data on cell sizes, we studied actual shape and size, in vivo arrangement, and potential nutrient exchange area of plant cortical cells (CCs) using computer-aided three-dimensional (3-D) reconstructions based on semithin serial sections. We extrapolated a factual fungal biomass in ECMs (Hartig net (HN) included) of 1.71 t ha(-1) FW (0.36 t ha(-1) DW) for the top 5 cm of soil for an autochthonous, montane, optimum Norway spruce stand in the Tyrolean Alps. The corresponding potential nutrient exchange area in ECMs including main axes of ECM systems, which is defined as the sum of interfaces between plant CCs and the HN, amounts to at least 3.2 × 10(5) m(2) ha(-1). This is the first study that determines the contribution of the HN to the total fungal biomass in ECMs as well as the quantification of its contact area. Our results may stimulate future research on fungal below-ground processes and their impact on the global carbon cycle.

LARGE STRAIN STIMULATION PROMOTES EXTRACELLULAR MATRIX PRODUCTION AND STIFFNESS IN AN ELASTOMERIC SCAFFOLD MODEL

PubMed Central

D’more, Antonio; Soares, Joao; Stella, John A.; Zhang, Will; Amoroso, Nicholas J.; Mayer, John E.; Wagner, William R.; Sacks, Michael S.

2016-01-01

Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC biosynthetic behavior was quite sensitive to tissue strain maximum level, and that collagen was the primary ECM component synthesized. Moreover, we found that while a 30% peak strain level achieved maximum ECM synthesis rate, further increases in strain level lead to a reduction in ECM biosynthesis. Subsequent mechanical analysis of the formed collagen fiber network was performed by removing the scaffold mechanical responses using a strain-energy based approach, showing that the de-novo collagen also demonstrated mechanical behaviors substantially better than previously obtained with small strain training and comparable to mature collagenous tissues. We conclude that the application of large deformations can play a critical role not only in the quantity of ECM synthesis (i.e. the rate of mass production), but also on the modulation of the stiffness of the newly formed ECM constituents. The improved understanding of the process of growth and development of ECM in these mechano-sensitive cell-scaffold systems will lead to more rational design and manufacturing of engineered tissues operating under highly demanding mechanical environments. PMID:27344402

Diamagnetic chemical exchange saturation transfer (diaCEST) affords magnetic resonance imaging of extracellular matrix hydrogel implantation in a rat model of stroke.

PubMed

Jin, Tao; Nicholls, Francesca J; Crum, William R; Ghuman, Harmanvir; Badylak, Stephen F; Modo, Michel

2017-01-01

Extracellular matrix (ECM) is widely used as an inductive biological scaffold to repair soft tissue after injury by promoting functional site-appropriate remodeling of the implanted material. However, there is a lack of non-invasive analysis methods to monitor the remodeling characteristics of the ECM material after implantation and its biodegradation over time. We describe the use of diamagnetic chemical exchange saturation transfer (CEST) magnetic resonance imaging to monitor the distribution of an ECM hydrogel after intracerebral implantation into a stroke cavity. In vitro imaging indicated a robust concentration-dependent detection of the ECM precursor and hydrogel at 1.8 and 3.6 ppm, which broadly corresponded to chondroitin sulfate and fibronectin. This detection was robust to changes in pH and improved at 37 °C. In vivo implantation of ECM hydrogel into the stroke cavity in a rat model corresponded macroscopically to the distribution of biomaterial as indicated by histology, but mismatches were also evident. Indeed, CEST imaging detected an endogenous "increased deposition". To account for this endogenous activity, pre-implantation images were subtracted from post-implantation images to yield a selective visualization of hydrogel distribution in the stroke cavity and its evolution over 7 days. The CEST detection of ECM returned to baseline within 3 days due to a decrease in fibronectin and chondroitin sulfate in the hydrogel. The distribution of ECM hydrogel within the stroke cavity is hence feasible in vivo, but further advances are required to warrant a selective long-term monitoring in the context of biodegradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lung extracellular matrix and redox regulation

PubMed Central

Watson, Walter H.; Ritzenthaler, Jeffrey D.; Roman, Jesse

2016-01-01

Pulmonary fibrosis affects millions worldwide and, even though there has been a significant investment in understanding the processes involved in wound healing and maladaptive repair, a complete understanding of the mechanisms responsible for lung fibrogenesis eludes us, and interventions capable of reversing or halting disease progression are not available. Pulmonary fibrosis is characterized by the excessive expression and uncontrolled deposition of extracellular matrix (ECM) proteins resulting in erosion of the tissue structure. Initially considered an ‘end-stage’ process elicited after injury, these events are now considered pathogenic and are believed to contribute to the course of the disease. By interacting with integrins capable of signal transduction and by influencing tissue mechanics, ECM proteins modulate processes ranging from cell adhesion and migration to differentiation and growth factor expression. In doing so, ECM proteins help orchestrate complex developmental processes and maintain tissue homeostasis. However, poorly controlled deposition of ECM proteins promotes inflammation, fibroproliferation, and aberrant differentiation of cells, and has been implicated in the pathogenesis of pulmonary fibrosis, atherosclerosis and cancer. Considering their vital functions, ECM proteins are the target of investigation, and oxidation–reduction (redox) reactions have emerged as important regulators of the ECM. Oxidative stress invariably accompanies lung disease and promotes ECM expression directly or through the overproduction of pro-fibrotic growth factors, while affecting integrin binding and activation. In vitro and in vivo investigations point to redox reactions as targets for intervention in pulmonary fibrosis and related disorders, but studies in humans have been disappointing probably due to the narrow impact of the interventions tested, and our poor understanding of the factors that regulate these complex reactions. This review is not meant to provide a comprehensive review of this field, but rather to highlight what has been learned and to raise interest in this area in need of much attention. PMID:26938939

Locostatin, a disrupter of Raf kinase inhibitor protein, inhibits extracellular matrix production, proliferation, and migration in human uterine leiomyoma and myometrial cells.

PubMed

Janjusevic, Milijana; Greco, Stefania; Islam, Md Soriful; Castellucci, Clara; Ciavattini, Andrea; Toti, Paolo; Petraglia, Felice; Ciarmela, Pasquapina

2016-11-01

To investigate the presence of Raf kinase inhibitor protein (RKIP) in human myometrium and leiomyoma as well as to determine the effect of locostatin (RKIP inhibitor) on extracellular matrix (ECM) production, proliferation, and migration in human myometrial and leiomyoma cells. Laboratory study. Human myometrium and leiomyoma. Thirty premenopausal women who were admitted to the hospital for myomectomy or hysterectomy. Myometrial and leiomyoma tissues were used to investigate the localization and the expression level of RKIP through immunohistochemistry and Western blotting. Myometrial and leiomyoma cells were treated with locostatin (10 μM) to measure ECM expression by real-time polymerase chain reaction, GSK3β expression by Western blotting, cell migration by wound-healing assay, and cell proliferation by MTT assay and immunocytochemistry. The expression of RKIP in human myometrial and leiomyoma tissue; ECM components and GSK3β expression, migration, and proliferation in myometrial and leiomyoma cells. RKIP is expressed in human myometrial and leiomyoma tissue. Locostatin treatment resulted in the activation of the mitogen-activated protein kinase (MAPK) signal pathway (ERK phosphorylation), providing a powerful validation of our targeting protocol. Further, RKIP inhibition by locostatin reduces ECM components. Moreover, the inhibition of RKIP by locostatin impaired cell proliferation and migration in both leiomyoma and myometrial cells. Finally, locostatin treatment reduced GSK3β expression. Therefore, even if the activation of MAPK pathway should increase proliferation and migration, the destabilization of GSK3β leads to the reduction of proliferation and migration of myometrial and leiomyoma cells. Our results indicate that RKIP may be involved in leiomyoma pathophysiology. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Increased tenascin C and Toll-like receptor 4 levels in visceral adipose tissue as a link between inflammation and extracellular matrix remodeling in obesity.

PubMed

Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Ramírez, Beatriz; Rotellar, Fernando; Valentí, Victor; Silva, Camilo; Gil, María J; Salvador, Javier; Frühbeck, Gema

2012-10-01

Obesity is associated with an altered inflammatory and extracellular matrix (ECM) profile. Tenascin C (TNC) is an ECM glycoprotein with proinflammatory effects. We aimed to explore the expression levels of TNC in adipose tissue analyzing the contribution of adipocytes and stromovascular fraction cells (SVFC) as well as its impact on inflammation and ECM regulation. We also analyzed the effect of the stimulation with TNF-α and lipopolysaccharide (LPS) on both SVFC and adipocytes. Samples obtained from 75 subjects were used in the study. Expression levels of TNC, TLR4, MMP2, and MMP9 were analyzed in visceral adipose tissue (VAT) as well as in both adipocytes and SVFC. In addition, Tnc expression was measured in two mice models of obesity. We show, for the first time, that VAT expression levels of TNC are increased in normoglycemic and type 2 diabetic obese patients (P<0.01) as well as in obese patients with nonalcoholic steatohepatitis (P<0.01). Furthermore, expression levels of Tnc in epididymal adipose tissue from two different mice models of obesity were significantly increased (P<0.01). TNC and TLR4 were mainly expressed by SVFC, and its expression was significantly enhanced (P<0.01) by TNF-α treatment. LPS treatment also increased mRNA levels of TNC. Moreover, the addition of exogenous TNC induced (P<0.05) TLR4 and CCL2 mRNA expression in human adipocyte cultures. These findings indicate that TNC is involved in the etiopathology of obesity via visceral adipose tissue inflammation representing a link with ECM remodeling.

Age- and gender-related alteration in plasma advanced oxidation protein products (AOPP) and glycosaminoglycan (GAG) concentrations in physiological ageing.

PubMed

Komosinska-Vassev, Katarzyna; Olczyk, Pawel; Winsz-Szczotka, Katarzyna; Kuznik-Trocha, Kornelia; Klimek, Katarzyna; Olczyk, Krystyna

2012-02-13

The authors studied the role of increased oxidative stress in the development of oxidative protein damage and extracellular matrix (ECM) components in ageing. The age- and gender-associated disturbances in connective tissue metabolism were evaluated by the plasma chondroitin sulphated glycosaminoglycans (CS-GAG) and non-sulphated GAG-hyaluronan (HA) measurements. Plasma concentration of advanced oxidation protein products (AOPP) was analysed in order to assess oxidative protein damage and evaluate the possible deleterious role of oxidative phenomenon on tissue proteoglycans' metabolism during the physiological ageing process. Sulphated and non-sulphated GAGs as well as AOPP were quantified in plasma samples from 177 healthy volunteers. A linear age-related decline of plasma CS-GAG level was found in this study (r=-0.46; p<0.05). In contrast, HA concentrations rise gradually with age (r=0.44; p<0.05) in plasma samples. For both ECM components, the observed differences were not gender-specific. A strong age-dependent relationship has been shown in regard to AOPP. AOPP levels significantly increased with age (r=0.63; p<0.05), equally strongly in both men (r=0.69; p<0.05) and women (r=0.57; p<0.05) during physiological ageing. A significant correlation was found between the concentrations of AOPP and both CS-GAG (r=-0.31; p<0.05) and HA (r=0.33; p<0.05). Proceeding with age changes in the ECM are reflected by CS-GAG and HA plasma levels. Strong correlations between AOPP and ECM components indicate that oxidative stress targets protein and non-protein components of the connective tissue matrix during human ageing.

Early Impairment of Lung Mechanics in a Murine Model of Marfan Syndrome

PubMed Central

Uriarte, Juan J.; Meirelles, Thayna; Gorbenko del Blanco, Darya; Nonaka, Paula N.; Campillo, Noelia; Sarri, Elisabet; Navajas, Daniel; Egea, Gustavo; Farré, Ramon

2016-01-01

Early morbidity and mortality in patients with Marfan syndrome (MFS) -a connective tissue disease caused by mutations in fibrillin-1 gene- are mainly caused by aorta aneurysm and rupture. However, the increase in the life expectancy of MFS patients recently achieved by reparatory surgery promotes clinical manifestations in other organs. Although some studies have reported respiratory alterations in MFS, our knowledge of how this connective tissue disease modifies lung mechanics is scarce. Hence, we assessed whether the stiffness of the whole lung and of its extracellular matrix (ECM) is affected in a well-characterized MFS mouse model (FBN1C1039G/+). The stiffness of the whole lung and of its ECM were measured by conventional mechanical ventilation and atomic force microscopy, respectively. We studied 5-week and 9-month old mice, whose ages are representative of early and late stages of the disease. At both ages, the lungs of MFS mice were significantly more compliant than in wild type (WT) mice. By contrast, no significant differences were found in local lung ECM stiffness. Moreover, histopathological lung evaluation showed a clear emphysematous-like pattern in MFS mice since alveolar space enlargement was significantly increased compared with WT mice. These data suggest that the mechanism explaining the increased lung compliance in MFS is not a direct consequence of reduced ECM stiffness, but an emphysema-like alteration in the 3D structural organization of the lung. Since lung alterations in MFS are almost fully manifested at an early age, it is suggested that respiratory monitoring could provide early biomarkers for diagnosis and/or follow-up of patients with the Marfan syndrome. PMID:27003297

Application of new optical coherence elastography to monitor the mineralization processing in bone tissue engineering constructs

NASA Astrophysics Data System (ADS)

Guan, Guangying; Song, Shaozhen; Huang, Zhihong; Yang, Ying

2015-03-01

Generation of functional tissue in vitro through tissue engineering technique is a promising direction to repair and replace malfunctioned organ and tissue in the modern medicine for various diseases which could not been treated well by conventional therapy. Similar to the embryo development, the generation of tissue in vitro is a highly dynamic processing. Obtaining the feedback of the processing real time is highly demanded. In this study, a new methodology has been explored aiming to monitor the morphological and mechanical property alteration of bone tissue engineering constructs simultaneously. Optical coherence elastography (OCE) equipped with a LDS V201 permanent magnet shaker and a modulated acoustic radiation force (ARF) to provide a vibration signal, has been used for the real time and non-destructive monitoring. A phantom construct system has been used to optimize the measurement conditions in which agar hydrogel with concentration from 0, 0.75 to 2% with/without hydroxyappatite particles have been injected to 3D porous poly (lactic acid) scaffolds to simulate the collagenous extracellular matrix (ECM) and mineralized ECM. The structural and elastography images of the constructs have clearly demonstrated the linear relation with the increased mechanical property versus the increase of agar concentration within the pores of the scaffolds. The MG63 bone cells seeded in the scaffolds and cultured for 4 weeks have been monitored by the established protocol exhibiting the increased mechanical strength in the pore wall where the ECM or mineralized ECM was assumed to be formed in comparison to empty pores. This study confirms that OCE-ARF could become a valuable tool in regenerative medicine to assess the biological events during in vitro culture and conditioning.

Physical training improves visceral adipose tissue health by remodelling extracellular matrix in rats with estrogen absence: a gene expression analysis.

PubMed

Duarte, Fernanda O; Gomes-Gatto, Camila do Valle; Oishi, Jorge C; Lino, Anderson Diogo de S; Stotzer, Uliana S; Rodrigues, Maria Fernanda C; Gatti da Silva, Guilherme H; Selistre-de-Araújo, Heloisa S

2017-08-01

Adipose tissue development is associated with modifications involving extracellular matrix remodelling, and metalloproteinases play a significant role in this process. Reduced circulating sexual hormones cause impacts on the size, morphology and functions of the adipose tissue, increasing susceptibility to diseases. This study investigated whether exercise training may be an alternative strategy to combat the effects promoted by estrogen decay through modulation in gene expression patterns in the extracellular matrix (ECM) of visceral adipose tissue of ovariectomized rats. Nulliparous rats (n = 40) were randomly distributed into four groups (n = 10/group): sham sedentary (Sh-S), sham resistance training (Sh-Rt), ovariectomized sedentary (Ovx-S) and ovariectomized resistance training (Ovx-Rt). The Sh-S animals did not have any type of training. The body mass and food intake, ECM gene expression, gelatinase MMP-2 activity and adipocyte area were measured. A lack of estrogen promoted an increase in body mass, food intake and the visceral, parametrial and subcutaneous adipocyte areas. The ovariectomy upregulated the expression of MMP-2, MMP-9, TGF-β, CTGF, VEGF-A and MMP-2 activity. On the other hand, resistance training decreased the body mass, food intake and the adipocyte area of the three fat depots analysed; upregulated TIMP-1, VEGF-A and MMP-2 gene expression; downregulated MMP-9, TGF-β and CTGF gene expression; and decreased the MMP-2 activity. We speculate that resistance training on a vertical ladder could play an important role in maintaining and remodelling ECM by modulation in the ECM gene expression and MMP-2 activity, avoiding its destabilization which is impaired by the lack of estrogen. © 2017 The Authors. International Journal of Experimental Pathology © 2017 International Journal of Experimental Pathology.

Elastic, silk-cardiac extracellular matrix hydrogels exhibit time-dependent stiffening that modulates cardiac fibroblast response

PubMed Central

Stoppel, Whitney L.; Gao, Albert E.; Greaney, Allison M.; Partlow, Benjamin P.; Bretherton, Ross C.; Kaplan, David L.; Black, Lauren D.

2018-01-01

Heart failure is the leading cause of death in the United States and rapidly becoming the leading cause of death worldwide. While pharmacological treatments can reduce progression to heart failure following myocardial infarction, there still exists a need for new therapies that promote better healing post injury for a more functional cardiac repair and methods to understand how the changes to tissue mechanical properties influence cell phenotype and function following injury. To address this need, we have optimized a silk-based hydrogel platform containing cardiac tissue-derived extracellular matrix (cECM). These silk-cECM hydrogels have tunable mechanical properties, as well as rate-controllable hydrogel stiffening over time. In vitro, silk-cECM scaffolds led to enhanced cardiac fibroblast (CF) cell growth and viability with culture time. cECM incorporation improved expression of integrin an focal adhesion proteins, suggesting that CFs were able to interact with the cECM in the hydrogel. Subcutaneous injection of silk hydrogels in rats demonstrated that addition of the cECM led to endogenous cell infiltration and promoted endothelial cell ingrowth after 4 weeks in vivo. This naturally derived silk fibroin platform is applicable to the development of more physiologically relevant constructs that replicate healthy and diseased tissue in vitro and has the potential to be used as an injectable therapeutic for cardiac repair. PMID:27480328

Vinculin is required for cell polarization, migration, and extracellular matrix remodeling in 3D collagen.

PubMed

Thievessen, Ingo; Fakhri, Nikta; Steinwachs, Julian; Kraus, Viola; McIsaac, R Scott; Gao, Liang; Chen, Bi-Chang; Baird, Michelle A; Davidson, Michael W; Betzig, Eric; Oldenbourg, Rudolf; Waterman, Clare M; Fabry, Ben

2015-11-01

Vinculin is filamentous (F)-actin-binding protein enriched in integrin-based adhesions to the extracellular matrix (ECM). Whereas studies in 2-dimensional (2D) tissue culture models have suggested that vinculin negatively regulates cell migration by promoting cytoskeleton-ECM coupling to strengthen and stabilize adhesions, its role in regulating cell migration in more physiologic, 3-dimensional (3D) environments is unclear. To address the role of vinculin in 3D cell migration, we analyzed the morphodynamics, migration, and ECM remodeling of primary murine embryonic fibroblasts (MEFs) with cre/loxP-mediated vinculin gene disruption in 3D collagen I cultures. We found that vinculin promoted 3D cell migration by increasing directional persistence. Vinculin was necessary for persistent cell protrusion, cell elongation, and stable cell orientation in 3D collagen, but was dispensable for lamellipodia formation, suggesting that vinculin-mediated cell adhesion to the ECM is needed to convert actin-based cell protrusion into persistent cell shape change and migration. Consistent with this finding, vinculin was necessary for efficient traction force generation in 3D collagen without affecting myosin II activity and promoted 3D collagen fiber alignment and macroscopical gel contraction. Our results suggest that vinculin promotes directionally persistent cell migration and tension-dependent ECM remodeling in complex 3D environments by increasing cell-ECM adhesion and traction force generation. © FASEB.

Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma

PubMed Central

Ramos, Grasieli de Oliveira; Bernardi, Lisiane; Lauxen, Isabel; Sant’Ana Filho, Manoel; Horwitz, Alan Rick; Lamers, Marcelo Lazzaron

2016-01-01

Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization. PMID:26978651

Electrochemical metallization memories--fundamentals, applications, prospects.

PubMed

Valov, Ilia; Waser, Rainer; Jameson, John R; Kozicki, Michael N

2011-06-24

This review focuses on electrochemical metallization memory cells (ECM), highlighting their advantages as the next generation memories. In a brief introduction, the basic switching mechanism of ECM cells is described and the historical development is sketched. In a second part, the full spectra of materials and material combinations used for memory device prototypes and for dedicated studies are presented. In a third part, the specific thermodynamics and kinetics of nanosized electrochemical cells are described. The overlapping of the space charge layers is found to be most relevant for the cell properties at rest. The major factors determining the functionality of the ECM cells are the electrode reaction and the transport kinetics. Depending on electrode and/or electrolyte material electron transfer, electro-crystallization or slow diffusion under strong electric fields can be rate determining. In the fourth part, the major device characteristics of ECM cells are explained. Emphasis is placed on switching speed, forming and SET/RESET voltage, R(ON) to R(OFF) ratio, endurance and retention, and scaling potentials. In the last part, circuit design aspects of ECM arrays are discussed, including the pros and cons of active and passive arrays. In the case of passive arrays, the fundamental sneak path problem is described and as well as a possible solution by two anti-serial (complementary) interconnected resistive switches per cell. Furthermore, the prospects of ECM with regard to further scalability and the ability for multi-bit data storage are addressed.

Decellularized bone extracellular matrix and human dental pulp stem cells as a construct for bone regeneration.

PubMed

Paduano, Francesco; Marrelli, Massimo; Alom, Noura; Amer, Mahetab; White, Lisa J; Shakesheff, Kevin M; Tatullo, Marco

2017-06-01

Dental pulp tissue represents a source of mesenchymal stem cells that have a strong differentiation potential towards the osteogenic lineage. The objective of the current study was to examine in vitro osteogenic induction of dental pulp stem cells (DPSCs) cultured on hydrogel scaffolds derived from decellularized bone extracellular matrix (bECM) compared to collagen type I (Col-I), the major component of bone matrix. DPSCs in combination with bECM hydrogels were cultured under three different conditions: basal medium, osteogenic medium and medium supplemented with growth factors (GFs) and cell growth, mineral deposition, gene and protein expression were investigated. The DPSCs/bECM hydrogel constructs cultured in basal medium showed that cells were viable after three weeks and that the expression of runt-related transcription factor 2 (RUNX-2) and bone sialoprotein (BSP) were significantly upregulated in the absence of extra osteogenic inducers compared to Col-I hydrogel scaffolds. In addition, the protein expression levels of BSP and osteocalcin were higher on bECM with respect to Col-I hydrogel scaffolds. Furthermore, DPSCs/bECM hydrogels cultured with osteogenic or GFs supplemented medium displayed a higher upregulation of the osteo-specific markers compared to Col-I hydrogels in identical media. Collectively, our results demonstrate that bECM hydrogels might be considered as suitable scaffolds to support osteogenic differentiation of DPSCs.

Electrochemical metallization memories—fundamentals, applications, prospects

NASA Astrophysics Data System (ADS)

Valov, Ilia; Waser, Rainer; Jameson, John R.; Kozicki, Michael N.

2011-06-01

This review focuses on electrochemical metallization memory cells (ECM), highlighting their advantages as the next generation memories. In a brief introduction, the basic switching mechanism of ECM cells is described and the historical development is sketched. In a second part, the full spectra of materials and material combinations used for memory device prototypes and for dedicated studies are presented. In a third part, the specific thermodynamics and kinetics of nanosized electrochemical cells are described. The overlapping of the space charge layers is found to be most relevant for the cell properties at rest. The major factors determining the functionality of the ECM cells are the electrode reaction and the transport kinetics. Depending on electrode and/or electrolyte material electron transfer, electro-crystallization or slow diffusion under strong electric fields can be rate determining. In the fourth part, the major device characteristics of ECM cells are explained. Emphasis is placed on switching speed, forming and SET/RESET voltage, RON to ROFF ratio, endurance and retention, and scaling potentials. In the last part, circuit design aspects of ECM arrays are discussed, including the pros and cons of active and passive arrays. In the case of passive arrays, the fundamental sneak path problem is described and as well as a possible solution by two anti-serial (complementary) interconnected resistive switches per cell. Furthermore, the prospects of ECM with regard to further scalability and the ability for multi-bit data storage are addressed.

Bile canaliculi formation and biliary transport in 3D sandwich-cultured hepatocytes in dependence of the extracellular matrix composition.

PubMed

Deharde, Daniela; Schneider, Christin; Hiller, Thomas; Fischer, Nicolas; Kegel, Victoria; Lübberstedt, Marc; Freyer, Nora; Hengstler, Jan G; Andersson, Tommy B; Seehofer, Daniel; Pratschke, Johann; Zeilinger, Katrin; Damm, Georg

2016-10-01

Primary human hepatocytes (PHH) are still considered as gold standard for investigation of in vitro metabolism and hepatotoxicity in pharmaceutical research. It has been shown that the three-dimensional (3D) cultivation of PHH in a sandwich configuration between two layers of extracellular matrix (ECM) enables the hepatocytes to adhere three dimensionally leading to formation of in vivo like cell-cell contacts and cell-matrix interactions. The aim of the present study was to investigate the influence of different ECM compositions on morphology, cellular arrangement and bile canaliculi formation as well as bile excretion processes in PHH sandwich cultures systematically. Freshly isolated PHH were cultured for 6 days between two ECM layers made of collagen and/or Matrigel in four different combinations. The cultures were investigated by phase contrast microscopy and immunofluorescence analysis with respect to cell-cell connections, repolarization as well as bile canaliculi formation. The influence of the ECM composition on cell activity and viability was measured using the XTT assay and a fluorescent dead or alive assay. Finally, the bile canalicular transport was analyzed by live cell imaging to monitor the secretion and accumulation of the fluorescent substance CDF in bile canaliculi. Using collagen and Matrigel in different compositions in sandwich cultures of hepatocytes, we observed differences in morphology, cellular arrangement and cell activity of PHH in dependence of the ECM composition. Sandwich-cultured hepatocytes with an underlay of collagen seem to represent the best in vivo tissue architecture in terms of formation of trabecular cell arrangement. Cultures overlaid with collagen were characterized by the formation of abundant bile canaliculi, while the bile canaliculi network in hepatocytes cultured on a layer of Matrigel and overlaid with collagen showed the most branched and stable canalicular network. All cultures showed a time-dependent leakage of CDF from the bile canaliculi into the culture supernatant with variations in dependence on the used matrix combination. In conclusion, the results of this study show that the choice of ECM has an impact on the morphology, cell assembly and bile canaliculi formation in PHH sandwich cultures. The morphology and the multicellular arrangement were essentially influenced by the underlaying matrix, while bile excretion and leakage of sandwich-cultured hepatocytes were mainly influenced by the overlay matrix. Leaking and damaged bile canaliculi could be a limitation of the investigated sandwich culture models in long-term excretion studies.

Mechanics and crack formation in the extracellular matrix with articular cartilage as a model system

NASA Astrophysics Data System (ADS)

Kearns, Sarah; Silverberg, Jesse; Bonassar, Lawrence; Cohen, Itai; Das, Moumita

We investigate the mechanical structure-function relations in the extracellular matrix (ECM) with focus on crack formation and failure. As a model system, our study focuses on the ECM in articular cartilage (AC), the tissue that covers the ends of bones, and distributes load in joints including in the knees, shoulders, and hips. The strength, toughness, and crack resistance of native articular cartilage is unparalleled in materials made by humankind. This mechanical response is mainly due to its ECM. The ECM in AC has two major mechanobiological components: a network of the biopolymer collagen and a flexible aggrecan gel. We model this system as a biopolymer network embedded in a swelling gel, and investigate the conditions for the formation and propagation of cracks using a combination of rigidity percolation theory and energy minimization approaches. Our results may provide useful insights into the design principles of the ECM as well as of biomimetic hydrogels that are mechanically robust and can, at the same time, easily adapt to cues in their surroundings. This work was partially supported by a Cottrell College Science Award.

Fundamentals of protein and cell interactions in biomaterials.

PubMed

Aiyelabegan, Hammed Tanimowo; Sadroddiny, Esmaeil

2017-04-01

The extracellular matrix (ECM) is an active and complex microenvironment with outstanding biomechanical, biophysical, and biochemical characteristics, which can indirectly or directly controls cell adhesion, migration, proliferation, and differentiation, as well as partaking in regeneration and homeostasis of organs and tissues. The ECM has captivated a great deal of attention with the rapid progress of tissue engineering (TE) in the field of regenerative medicine (RM). Approaches to TE, RM and cancer therapy center on the necessity to deliver cell signals to direct cell proliferation and differentiation. These "external signals" are induced from cell-cell, and cell-ECM, interactions, as well as from physico-chemical, mechanical stimuli and growth factors. With the advent of new biomaterials such as casein, we gave a general insight into cell-ECM protein interactions in biomaterials and their applications in TE, RM and cancer therapy. An account of the main ECM molecules and cellular receptors with emphasis on integrins and its ligands was given, their effect on the induction of particular signal transduction pathways is also elucidated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Advanced communications technology satellite high burst rate link evaluation terminal experiment control and monitor software user's guide, version 1.0

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

1992-01-01

The Experiment Control and Monitor (EC&M) software was developed at NASA Lewis Research Center to support the Advanced Communications Technology Satellite (ACTS) High Burst Rate Link Evaluation Terminal (HBR-LET). The HBR-LET is an experimenter's terminal to communicate with the ACTS for various investigations by government agencies, universities, and industry. The EC&M software is one segment of the Control and Performance Monitoring (C&PM) software system of the HBR-LET. The EC&M software allows users to initialize, control, and monitor the instrumentation within the HBR-LET using a predefined sequence of commands. Besides instrument control, the C&PM software system is also responsible for computer communication between the HBR-LET and the ACTS NASA Ground Station and for uplink power control of the HBR-LET to demonstrate power augmentation during rain fade events. The EC&M Software User's Guide, Version 1.0 (NASA-CR-189160) outlines the commands required to install and operate the EC&M software. Input and output file descriptions, operator commands, and error recovery procedures are discussed in the document.

The effects of multiple metal contamination on ectomycorrhizal Scots pine (Pinus sylvestris) seedlings.

PubMed

Hartley, J; Cairney, J W; Freestone, P; Woods, C; Meharg, A A

1999-09-01

Experiments were conducted to investigate the effects of single and multiple metal contamination (Cd, Pb, Zn, Sb, Cu) on Scots pine seedlings colonised by ectomycorrhizal (ECM) fungi from natural soil inoculum. Seedlings were grown in either contaminated field soil from the site of a chemical accident, soils amended with five metals contaminating the site, or in soil from an uncontaminated control site. Although contaminated and metal-amended soil significantly inhibited root and shoot growth of the Scots pine seedlings, total root tip density was not affected. Of the five metals tested in amended soils, Cd was the most toxic to ECM Scots pine. Field-contaminated soil had a toxic effect on ECM fungi associated with Scots pine seedlings and caused shifts in ECM species composition on ECM seedlings. When compared to soils amended with only one metal, soils amended with a combination of all five metals tested had lower relative toxicity and less accumulation of Pb, Zn and Sb into seedlings. This would indicate that the toxicity of multiple metal contamination cannot be predicted from the individual toxicity of the metals investigated.

Extracellular matrix-derived hydrogels for dental stem cell delivery.

PubMed

Viswanath, Aiswarya; Vanacker, Julie; Germain, Loïc; Leprince, Julian G; Diogenes, Anibal; Shakesheff, Kevin M; White, Lisa J; des Rieux, Anne

2017-01-01

Decellularized mammalian extracellular matrices (ECM) have been widely accepted as an ideal substrate for repair and remodelling of numerous tissues in clinical and pre-clinical studies. Recent studies have demonstrated the ability of ECM scaffolds derived from site-specific homologous tissues to direct cell differentiation. The present study investigated the suitability of hydrogels derived from different source tissues: bone, spinal cord and dentine, as suitable carriers to deliver human apical papilla derived mesenchymal stem cells (SCAP) for spinal cord regeneration. Bone, spinal cord, and dentine ECM hydrogels exhibited distinct structural, mechanical, and biological characteristics. All three hydrogels supported SCAP viability and proliferation. However, only spinal cord and bone derived hydrogels promoted the expression of neural lineage markers. The specific environment of ECM scaffolds significantly affected the differentiation of SCAP to a neural lineage, with stronger responses observed with spinal cord ECM hydrogels, suggesting that site-specific tissues are more likely to facilitate optimal stem cell behavior for constructive spinal cord regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 319-328, 2017. © 2016 Wiley Periodicals, Inc.