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Results for “Extracellular Matrix”

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PubMed1993

Cell density modulates growth, extracellular matrix, and protein synthesis of cultured rat mesangial cells.

Mesangial cell (MC) hyperplasia and accumulation of extracellular matrix are hallmarks of chronic glomerular disease. The present in vitro study examined the effects of cell density on growth, extracellular matrix formation, and protein synthesis of cultured rat MCs. A negative linear relationship was found between initial plating density and DNA synthesis per cell after 24 hours incubation in medium with 10% fetal calf serum (range: 1 x 10(3) to 7 x 10(5) MCs/2cm2, r = 0.996, P < 0.001). Enzyme-linked immunosorbent assay of the amount of fibronectin in the conditioned medium after 72 hours showed a negative relationship with increasing cell density. In contrast, the amount of cell-associated fibronectin increased to maximal values in confluent cultures, and no further increase was seen at supraconfluency. The relative collagen synthesis in the conditioned medium and cell layer--assessed by collagenase digestion after 5 hours [3H]proline pulse labeling--showed a similar pattern. Secreted collagen decreased with increasing cell density from 3.4% to 0.2% of total protein synthesis. In contrast, cell-associated collagen increased from 1.1% to 11.8% of newly synthesized protein until confluency followed by a decrease to 4.2% at supraconfluency. Specific immunoprecipitation of collagen types I, III, and IV revealed a significant (twofold) increase in collagen I synthesis per cell at confluency. Collagen III and IV synthesis was not affected by cell density. Specific protein expression in both the medium and cell layer were analyzed by two-dimensional polyacrylamide gel electrophoresis (150 to 20 kd, pI 5.0 to 7.0) after 20 hours steady-state metabolic labeling with [35S]methionine. Supraconfluent MCs displayed overexpression of 10, underexpression of four, new expression of five, and changed mobility of three different intracellular proteins. Of interest was the overexpression of two proteins (89 kd, pI 5.31 and 72 kd, pI 5.32) that were identified by immunoblotting as the stress proteins heat-shock protein 90 and glucose-related protein 78, respectively. The progressive increase of cell-associated fibronectin and collagens, particularly collagen type I, in confluent MCs resembles extracellular matrix accumulation in glomerular disease. The increased expression of stress proteins in supraconfluent MCs is of interest in view of the analogy between glomerulosclerosis and atherosclerosis in which stress proteins are expressed in high concentrations.

Animals↗

PubMed1994

Reciprocal interactions between human ovarian surface epithelial cells and adjacent extracellular matrix.

The human ovarian surface epithelium (OSE), or ovarian mesothelium, is functionally complex as seen by its capacity to proliferate, migrate, and contribute to ovulation and ovulatory repair in response to cyclic hormonal and environmental changes. We wished to determine whether this phenotypic versatility is reflected in cell-extracellular matrix interactions in primary and low-passage culture. Comparisons of cultures maintained on different substrata revealed that these cells form cohesive monolayers on plastic, while fibrin clots enhance cell dispersion, and thus may provide a migratory cue. The cells invaded Matrigel as multicellular aggregates, while collagen gels mediated a morphologic epithelial-mesenchymal conversion. On plastic, the cells produced extracellular matrix components characteristic of epithelial basement membrane (laminin and collagen type IV), as well as stroma (collagen types I and III). In addition, ovarian surface epithelial cells secreted serine proteases and matrix metalloproteinases. The levels of chymotrypsin- and elastase-like proteases were dictated by the substratum: low levels were secreted by cells grown on plastic, intermediate levels on collagen gels and fibrin clots, and most protease was produced on Matrigel. The rate of cell proliferation varied with the substrata and was inversely related to protease secretion. Integrin expression was greatest on plastic and least on collagen gels where integrins were downregulated with time. alpha 6/beta 4 was absent from all cells while varying levels of alpha 2, alpha 3, alpha 5, beta 1, and vitronectin receptor were detected depending on the culture substratum employed. In low-passage cultures of human ovarian surface epithelial cells, then, cell shape, growth, protease production, and integrin expression are modulated by the extracellular matrix. The cells, in turn, alter extracellular matrix by synthesis, lysis, and physical remodeling, and express both stromal and epithelial characteristics. The broad repertoire of these functions may be related to their mesodermal origin, and may reflect the expression of a dual, epithelio-mesenchymal phenotype by relatively immature, uncommitted cells. The results demonstrate the great complexity and versatility of these interactions which render OSE cells capable of participating in numerous physiological and pathological processes.

Adult↗

PubMed2003

Alternative splicing of papilin and the diversity of Drosophila extracellular matrix during embryonic morphogenesis.

Papilins are extracellular matrix proteins that share a particular, common order of types of protein domains. They occur widely, from nematodes to man, and can differ in the number of repeats of a given type of domain. Protein variety is increased by differential splicing of pre-mRNA. We report that Drosophila, which has a compact genome, expresses three splice variants of papilin during embryogenesis in developmentally defined patterns. These isoforms have different numbers of Kunitz and IgC2 domains. The papilin isoforms are expressed in specific cell types and contribute to different extracellular matrices in gastrulation folds, early mesoderm, heart formation, basement membranes, and elaboration of the excorporeal peritrophic membrane that lines the gut. This finding indicates an unexpectedly broad spectrum of different pericellular matrices in Drosophila embryos. Such papilin-containing matrices have developmental as well as functional significance, as we previously showed that both suppression of papilin synthesis and ectopic overexpression lethally disrupt organogenesis.

Alternative Splicing↗

PubMed1997

On the roles of extracellular matrix remodeling by gelatinase B.

Human extracellular matrix is constantly remodelled by de novo synthesis of structural components and by degradation of the matrix proteins by various proteinases. The secreted proteolytic enzymes are regulated at several levels: by control of gene transcription, by glycosylation, by specific inhibitors and by enzyme activation processes. The latter level most often involves clipping of a proenzyme or zymogen into an active proteinase. A series of such activation reactions leads to enzyme cascades. Whereas proteolytic activation is an all-or-none phenomenon, glycosylation usually has a restricted or fine-tuning effect on the catalytic activity of enzymes. Commonly, a two- to threefold reduction in specific activity is imposed by N-glycosylation on each member of the multi-enzyme chain. In a series comprising e.g. four enzymes, this can lead to significant influences (2(4)-3(4)-fold increase) on the substrate converting activity of the terminal member of a cascade. Gelatinase B is a terminal member of the protease cascade which leads to matrix degradation. It cleaves gelatins (denatured collagens or collagen fragments after digestion by collagenase) and other substrates and is thought to be involved in matrix remodeling during the normal processes of embryogenesis, tissue remodeling and development. Gelatinase B expression is upregulated in pathological states such as invasion of cancer cells and when leukocytes are released from the bone marrow and migrate towards an inflammatory focus. Proteases, including gelatinase B, are transcriptionally regulated by cytokines and directly by the activation processes. The gene regulation of enzyme inhibitors as well as other humoral factors, which contribute to protease activation, influence protease activities in an indirect way. Proteases might also play a role in the pathophysiology of chronic inflammation and autoimmunity by cleaving extracellular structural proteins and by generating proteolytic fragments. Indeed, these remnant fragments antigenically resemble the original precursor proteins, but are structurally and quantitatively different and may provoke an autoimmune response. Application of the knowledge of the structure, function and regulation of gelatinase B has contributed to the understanding of the mechanism of action of some gelatinase-inhibiting antirheumatic drugs and promises to contribute further to the development of novel treatment strategies for autoimmune diseases such as multiple sclerosis and for invasive cancers.

Animals↗

PubMed1992

Identification of a factor in fetal bovine serum that stabilizes the cumulus extracellular matrix. A role for a member of the inter-alpha-trypsin inhibitor family.

Fetal bovine serum (FBS) has been widely used in the culture of cumulus-oocyte complexes, since it is believed that FBS stabilizes the expanding cumulus extracellular matrix. In this study, we have identified a factor in FBS that is responsible for this effect. FBS was first fractionated by stepwise precipitation with ammonium sulfate followed by high performance liquid chromatography (HPLC) on a gel filtration column. Active fractions, as determined by their ability to stabilize the cumulus extracellular matrix in a bioassay system, were further purified by HPLC on DEAE ion-exchange and gel filtration columns. The purified factor was exhibited as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent Mr 150,000 and a single peak on a C-8 reverse-phase HPLC. The sequence of the first 14 NH2-terminal amino acids was determined by Edman degradation, revealing significant sequence identity of the bovine serum factor with the light chain shared by members of the inter-alpha-trypsin inhibitor family. Western blot analysis using anti-human I alpha I IgG shows that the antibody reacts positively with the purified factor, and immunodepletion of FBS with anti-I alpha I antibody agarose eliminated its ability to stabilize the extracellular matrix. This factor is found in mouse follicular fluid collected 6 h following human chorionic gonadotropin injection to stimulate ovulation, but not in unstimulated mice. Anti-I alpha I-positive epitopes were also localized within the cumulus extracellular matrix of mouse preovulatory follicles in immunocytochemical preparations using anti-human I alpha I IgG, supporting the possibility that this molecule or molecules may diffuse into follicular fluid after an ovulatory stimulus to act as structural linkers that ensure normal cumulus expansion, through stabilization of the cumulus extracellular matrix thus supporting the process of ovulation.

Alpha-Globulins↗

PubMed1999

Bisdiamine inhibits extracellular matrix formation and cell proliferation of atrioventricular mesenchyme from developing chick heart valves.

Abnormalities of the cushion tissues lead to atrioventricular septal defects (AVSD) and truncus arteriosus (TA). Bisdiamine exposure in the embryo frequently causes AVSD and TA in the newborn chick, mouse, or rat. We studied the effects of bisdiamine on mesenchymal cells grown in aggregate culture isolated from the developing atrioventricular valves of the stage-36 chick embryo. Fibronectin extracellular matrix formation and cell proliferation in the aggregates were assessed in various media. Chick serum stimulated the cells to produce an extracellular matrix and to divide, and the inclusion of bisdiamine inhibited both responses. If we isolated an extracellular matrix from a monolayer of mesenchymal cells and added the sonicated matrix to the medium containing serum and bisdiamine, the matrix incorporated into the aggregates and the cells entered the mitotic cycle. Our previous work established that cells need to attach to an intact extracellular matrix to begin cell division. Thus, we suggest that bisdiamine inhibits the normal formation of the extracellular matrix, leading to reduced cell proliferation, but it does not affect matrix-cell interaction. The lack of cushion growth in situ may be the cause of AVSD or TA.

Animals↗

PubMed2006

The inhibitory effects of endostatin on endothelial cells are modulated by extracellular matrix.

We investigated the ability of extracellular matrix (ECM) proteins to modulate the response of endothelial cells to both promoters and inhibitors of angiogenesis. Using human dermal microvascular endothelial cells (HDMEC), we found that cells demonstrated different adhesive properties and proliferative responses to the growth factor VEGF depending upon which ECM protein with which they were in contact, with fibronectin having the most impact on VEGF-induced HDMEC proliferation and survival. More importantly, we observed that ECM could modulate the ability of the angiogenic inhibitor endostatin to prevent endothelial cell proliferation, survival and migration. We observed that growth on vitronectin or fibronectin impaired the ability of endostatin to inhibit VEGF-induced HDMEC proliferation to the greatest extent as determined by BrdU incorporation. We found that, following growth on collagen I or collagen IV, endostatin only inhibited VEGF-induced HDMEC proliferation at the highest dose tested (2500 ng/ml). In a similar manner, we observed that growth on ECM proteins modulated the ability of endostatin to induce endothelial cell apoptosis, with growth on collagen I, fibronectin and collagen IV impairing endostatin-induced apoptosis. Interestingly, endostatin inhibited VEGF-induced HDMEC migration following culture on collagen I, collagen IV and laminin, while migration was not inhibited by endostatin following HDMEC culture on other matrices including vitronectin, fibronectin and tenascin-C. These results suggest that different matrix proteins may affect different mechanisms of endostatin inhibition of angiogenesis. Taken together, our results suggest that the ECM may have a profound impact on the ability of angiostatic molecules such as endostatin to inhibit angiogenesis and thus may have impact on the clinical efficacy of such inhibitors.

Apoptosis↗

PubMed2003

Calreticulin--an endoplasmic reticulum protein with calcium-binding activity is also found in the extracellular matrix.

Previous studies have reported that calreticulin (CRT), a calcium-binding and chaperoning protein, is expressed only in the endoplasmatic reticulum, nucleus and at the cell surface. In this study we clearly show that odontoblasts and predentin matrix contain CRT. To our knowledge, this is the first time CRT has been described in the extracellular matrix. The expression of CRT was studied by immunohistochemistry, ultrastructural immunocytochemistry and in situ hybridization in developing rat teeth. CRT was detected as a 59-kDa protein in rat pulp cell culture medium and dentin extracellular matrix extract by Western blotting. The presence of the protein was shown in rat odontoblasts and predentin with immunohistochemistry. At the ultrastructural level, the labeling was distributed in the rat odontoblasts, ameloblasts and predentin. Northern blotting showed the presence of CRT mRNA in rat molars, which was confirmed by in situ hybridization in odontoblasts and ameloblasts. We now present the first convincing evidence that CRT is found in extracellular matrix where it may play an important role in mineralization.

Ameloblasts↗

PubMed1982

Extracellular matrix synthesis by skeletal muscle in culture. Proteins and effect of enzyme degradation.

Extracellular matrix proteins produced by a mouse skeletal muscle cell line, G8-1, were isolated and characterized. Cultures were incubated with [35S]methionine or [3H]glycine and [3H]proline, and the labeled, substrate-attached proteins were obtained after cellular proteins were extracted by deoxycholate in neutral salt. The labeled matrix was analyzed by gel electrophoresis and fluorography before and after enzymatic digestion. Of the nine major bands present in the matrix, four were identified. Fibronectin and collagen were detected on the bases of their relative mobilities, differential labeling with 3H-versus 35S-labeled amino acids and their solubilization by protease free collagenase. High molecular weight material which was present in the matrix was also sensitive to collagenase and probably included cross-linked collagen and laminin. Proteins co-migrating with actin and myosin were also present in the extracellular matrix. These results are novel in that they demonstrate that the skeletal muscle phenotype, not contaminated with fibroblastic elements, is able to synthesize basal lamina-type macromolecules and incorporate them into an insoluble, extracellular matrix. Since this cell line is able to form functional synaptic contacts with neuronal cells, the influence of nerve on basal lamina production by muscle in vitro is possible.

Animals↗

PubMed2005

Varied low density lipoprotein binding property of proteoglycans synthesized by vascular smooth muscle cells cultured on extracellular matrix.

Earlier we showed that the extracellular matrix (ECM) secreted by vascular cells modulated proteoglycan synthesis by vascular smooth muscle cells in culture and altered the proteoglycan characteristics. In this study, we tested the hypothesis that these ECM-mediated alterations increased the affinity of the proteoglycans for plasma low density lipoprotein (LDL). Newly synthesized proteoglycans were isolated from smooth muscle cells cultured on the ECMs secreted by vascular endothelial cells, smooth muscle cells, or THP-1 macrophages and their binding affinity for LDL determined. Proteoglycans from all cultures contained sub-fractions that bound LDL with low and high affinity. However, compared with the cells plated on the endothelial cell ECM, the cells plated on the smooth muscle cell ECM and macrophage ECM synthesized significantly more high affinity proteoglycans. Removal of collagen, elastin, and chondroitin sulfates from the smooth muscle cell ECM and chondroitin sulfates from the macrophage ECM increased the production of high affinity proteoglycans by 15-22%. However, neutralization of fibronectin from both ECMs decreased the high affinity proteoglycans by 20%. Removal of matrix-bound growth factors had no effect on the synthesis of high affinity proteoglycans. Compared with the low affinity proteoglycans, the high affinity proteoglycans were larger, more sulfated and contained higher proportions of chondritin sulfate, dermatan sulfate, and N-sulfated heparan sulfate chains. These results suggest that the ECM-mediated alterations in vascular smooth muscle cell proteoglycans may lead to increased deposition of LDL in the arterial wall.

Binding, Competitive↗

PubMed1998

Expression of hepatocyte low-density lipoprotein receptor-related protein is post-transcriptionally regulated by extracellular matrix.

The low-density lipoprotein receptor-related protein (LRP) is a multifunctional member of the low-density lipoprotein receptor family that has been implicated in a variety of physiologic and pathologic processes. However, little is known about LRP regulation at the molecular level, and the factors that might mediate LRP have not yet been characterized. This is particularly true of hepatocytes, an important site of LRP expression. Hepatocyte gene expression is known to be dependent on extracellular matrix composition, although the effect of extracellular matrix on lipoprotein receptor expression has not yet been investigated. Also, the mechanisms by which the extracellular matrix affects hepatocyte gene expression are not well understood. In this study, we show that hepatocyte LRP expression decreases rapidly at the mRNA, protein, and functional levels on collagen type I, but remains high on an Engelbreth-Holm-Swarm sarcoma matrix-preparation, Matrigel. LRP function was assessed with ligand binding studies and a novel cytotoxicity assay, using Pseudomonas exotoxin A. Investigation of the mechanism of LRP down-regulation revealed a two-fold longer LRP mRNA half-life in hepatocytes cultured on Matrigel relative to collagen. Taken together, these studies reveal that LRP expression in primary hepatocytes is dependent on the extracellular matrix, and that matrix-dependent differences in hepatocyte LRP mRNA expression are primarily due to changes in mRNA stability, indicating for the first time that the expression of LRP is subject to post-transcriptional regulation.

Animals↗

PubMedDate not supplied

Distinct patterns of microvascular endothelial cell morphology are determined by extracellular matrix composition.

Endothelial interactions with the extracellular matrix (ECM) play important roles in angiogenesis but whether specific ECM signals can determine specific cellular morphologies is unclear. The authors compared in vitro ECM-induced morphological responses of the phenotypically distinct human placental microvascular endothelial cells (HPMECs) with large vessel endothelial cells (HUVECs). HPMECs showed distinct patterns of reorganization in response to collagen-I or collagen-IV (monolayer disruption, sprouting, migration) and Matrigel or laminin-A (intussusception, cord formation, tubulogenesis), and an intermediate response to fibrin; whereas HUVECs responded similarly to collagen-1 and Matrigel (elongation, lattice formation, vacuolation) and showed little response to fibrin. Although the extent of collagen and Matrigel responses of HPMECs were increased by serum, acidic or basic fibroblast growth factor (aFGF, bFGF), or vascular endothelial growth factor (VEGF), and varied with matrix protein concentration, the basic patterns were matrix specific, and were independent of fibronectin. The collagen responses correlated with disruption of adherens and tight junctions and the formation of filopodial protrusions. Matrigel responses were associated with up-regulated junctional localization of VE-cadherin, and tubulogenesis developed mainly through paracellular remodeling rather than intracellular vacuolation. Overall, these findings suggest that distinct ECM interactions stimulate specific morphological responses. These signals may regulate morphological behaviour in the angiogenesis cycle, switching endothelial cells between migratory and vasculogenic phenotypes.

Antigens, CD↗

PubMed2003

Role of extracellular matrix in kidney development and repair.

Extracellular matrix (ECM) molecules and their receptors exert a dynamic role in cell-matrix interactions during kidney development and repair processes. They provide a physical substratum for the spatial organization of the cells, but also regulate cell growth and proliferation by interacting with growth factors. In addition, they can regulate signal transduction pathways by binding to integrins or by modulating the activity of signaling molecules such as Wnts. ECM and ECM-related molecules control multiple (if not all) steps of kidney development, including ureteric bud branching morphogenesis, mesenchymal condensation, nephron formation, terminal differentiation of renal tubules, and glomerular basement membrane assembly. Their role still needs to be better documented in renal repair. The emergence of conditionally mutated mice for basement membrane components will provide a useful tool to demonstrate further the involvement of ECM and ECM-related proteins in development and repair.

Animals↗

PubMed1990

Extracellular matrix influences hormone and protein production by human chorionic villi.

Increasing evidence confirms that the extracellular matrix greatly influences cell behaviour and function. Collagen and fibrin are in contact with trophoblast throughout pregnancy. To investigate whether these two matrices influence hormone production by the trophoblast, explants from first-trimester chorionic villi were cultured for up to 30 days either a) in medium with agitation, b) embedded in type-I collagen (three-dimensional gels), or c) embedded in fibrin (three-dimensional gels). The supernatant culture medium was changed every 48 h and tested by radioimmunoassay for hCG, progesterone and pregnancy-associated plasma protein A. In addition, after 3, 7, 15, and 30 days of culture villi were fixed and studied by light and electron microscopy. Embedding in the extracellular matrix showed higher and longer-lasting production rates of all measured products and superior structural preservation as compared to cultures with agitation. Collagen matrix proved to be superior to fibrin. As established by several tests, this difference was neither due to thrombin used to polymerize fibrinogen, nor to differences in the diffusion rates through the two different matrices used. We conclude that extracellular matrix, particularly collagen, influences the synthesis of trophoblastic products. Embedding of the villous explants in three-dimensional gels constitutes a new method for long-term cultures of chorionic villi.

Chorionic Gonadotropin↗

PubMed1995

Tumor cell attachment to laminin promotes degradation of the extracellular matrix and cell migration in high-metastatic clone cells of RCT sarcoma in vitro.

We investigated the roles of extracellular matrix proteins, laminin and fibronectin, in promoting invasiveness through the extracellular matrix in high-metastatic [RCT(+)] clone cells established from poorly differentiated murine RCT sarcoma in C3H/He mice. Laminin stimulated the type IV collagenolytic activity of RCT(+) cells. After more than 6 h of incubation, the type IV collagenolysis of the cell-conditioned medium was significantly higher in laminin-treated groups compared with the control. The migration activity of RCT(+) cells was stimulated by laminin. However, fibronectin did not influence the type IV collagenolysis or cell migration in this clone cell. The amino acid sequence YIGSR, which is derived from laminin, inhibited the laminin-mediated cell attachment and the laminin-promoted type IV collagenolysis, as well as cell migration of RCT(+) cells. RGD derived from fibronectin did not influence the cell attachment to laminin or Matrigel in this clone. In the invasion assay employing a Matrigel coated filter in a Boyden chamber, YIGSR showed greater inhibition of invasion through the Matrigel than did RGD with RCT(+) cells. YIGSR might inhibit the promoted-matrix degradation and cell migration in response to the cell attachment to laminin by competing with laminin for binding to cell surface laminin receptor. We suggest that laminin-mediated cell attachment to the extracellular matrix may play a role in promoting the matrix degradation and cell migration during metastatic cascades.

Amino Acid Sequence↗

PubMed1993

Radiation-induced transforming growth factor beta and subsequent extracellular matrix reorganization in murine mammary gland.

Little is known about radiation-induced protein expression in vivo nor has the relationship between early molecular events and subsequent tissue repair, fibrosis, or carcinogenesis been fully appraised. In this study, expression of proteins involved in tissue remodeling was examined in mammary gland immediately and shortly after ionizing radiation exposure. Using indirect immunofluorescence, selected antigens were followed as a function of time after 0, 5, or 10 Gy of whole body gamma-radiation in the mammary gland of adult female BALB/c mice. Rapid induction of transforming growth factor beta (TGF beta) immunoreactivity was observed at 1 h post radiation. Extracellular and intracellular TGF beta increased in the periepithelial stromal sheath as evidenced by immunoreactivity with antibodies CC(1-30) and LC(1-30), respectively. Furthermore, both extracellular and intracellular TGF beta were unexpectedly expressed in the previously negative adipose stroma. Elevated expression persisted for 7 days after irradiation. Thus an early response to radiation exposure is the induction of TGF beta, which mediates myriad events during tissue repair, growth, and extracellular matrix production. The distribution of extracellular matrix proteins was examined as a function of time post radiation exposure. Collagen III immunoreactivity decreased in the periepithelial stroma at day 1. In contrast, at day 3 collagen III was newly evident in the adipose stroma, and periepithelial collagen III had increased in both abundance and intensity. By day 7 collagen III expression in the adipose stroma had resolved but was enhanced in the periepithelial stroma. Over this same period stromal collagen I immunoreactivity surrounding the epithelium became diffuse and possibly diminished. Fibronectin, laminin, and collagen IV localization were unchanged over the time course. I postulate that radiation-induced TGF beta may mediate the remodeling of the stromal extracellular matrix in the irradiated mammary gland.

Adipose Tissue↗

PubMed2006

Extracellular matrix functions in follicle maturation.

The extracellular matrix (ECM) promotes and/or inhibits many cellular processes, including but not limited to proliferation, differentiation, and survival, which must occur for follicle growth and oocyte maturation. The ECM regulation of cellular processes in ovarian cells is being investigated in many animal models, including avian, rat, bovine, porcine, rabbit, sheep, human, and mouse. Granulosa cells are more frequently employed; however, the culture of intact follicles and ovaries has been developed and enables ECM functions in folliculogenesis to be studied. ECM components that have been examined are used individually (collagen, laminin, fibronectin) or collectively (Matrigel, isolated basal lamina, and ECM produced by cell lines) in both two- and three-dimensional model systems. In granulosa cell cultures, ECM affects morphology, aggregation and communication, survival, proliferation, and steroidogenesis; whereas follicle and ovary cultures demonstrate a regulation of folliculogenesis. This article describes the ECM functionality on ovarian cells throughout development, and highlights the potential of developing technologies to identify structure-function relationships in follicle maturation.

Animals↗

PubMed2005

Integrin-supported fast rate intracellular delivery of plasmid DNA by extracellular matrix protein embedded calcium phosphate complexes.

Extracellular matrix (ECM) proteins, such as collagen and fibronectin, play vital roles in development and maintenance of hard tissue (bone or tooth) and are, consequently, thoroughly investigated for construction of biomimetic scaffolds in combination with calcium phosphate (CaP) material (the major component of hard tissue) for bone or dental tissue engineering. Realizing the natural affinity of ECM components toward inorganic constituents of hard tissue, we successfully constructed the nanohybrids of DNA/CaP particles with either collagen 1 or fibronectin, which finally possessed the capability of specific recognition of integrin receptor for being swiftly internalized across the plasma membrane, leading to remarkably high transgene expression in mammalian cells. This new approach with precise receptor-specific delivery as well as 10- to 50-fold enhanced efficiency level compared to the classical one, has immediate applications for basic research and large scale production of recombinant therapeutic proteins and looks promising for gene therapy.

3T3 Cells↗