scholarly journals Abnormal Mucosal Extracellular Matrix Deposition Is Associated with Increased TGF-β Receptor-expressing Mesenchymal Cells in a Mouse Model of Colitis

2003 ◽  
Vol 51 (9) ◽  
pp. 1177-1189 ◽  
Author(s):  
Christine V. Whiting ◽  
John F. Tarlton ◽  
Michael Bailey ◽  
Clare L. Morgan ◽  
Paul W. Bland

Transforming growth factor-β (TGF-β) depresses mucosal inflammation and upregulates extracellular matrix (ECM) deposition. We analyzed TGF-β receptors RI and RII as well as ECM components using the CD4+ T-cell-transplanted SCID mouse model of colitis. The principal change in colitis was an increased proportion of TGF-β RII+ mucosal mesenchymal cells, predominantly α-smooth muscle actin (SMA)+ myofibroblasts, co-expressing vimentin and basement membrane proteins, but not type I collagen. TGF-β RII+ SMA− fibroblasts producing type I collagen were also increased, particularly in areas of infiltration and in ulcers. Type IV collagen and laminin were distributed throughout the gut lamina propria in disease but were restricted to the basement membrane in controls. In areas of severe epithelial damage, type IV collagen was lost and increased type I collagen was observed. To examine ECM production by these cells, mucosal mesenchymal cells were isolated. Cultured cells exhibited a similar phenotype and matrix profile to those of in vivo cells. The data suggested that there were at least two populations of mesenchymal cells responsible for ECM synthesis in the mucosa and that ligation of TGF-β receptors on these cells resulted in the disordered and increased ECM production observed in colitic mucosa.

1990 ◽  
Vol 96 (1) ◽  
pp. 159-169
Author(s):  
A.E. Canfield ◽  
T.D. Allen ◽  
M.E. Grant ◽  
S.L. Schor ◽  
A.M. Schor

Bovine retinal pericytes plated on a two-dimensional substratum display a characteristic stellate morphology. In post-confluent cultures these cells aggregate spontaneously to form multicellular nodules. The same cells plated within a three-dimensional collagen matrix display an elongated sprouting morphology. Sprouting pericytes may be embedded within a gel either as individual cells or as multicellular aggregates. We have compared the nature of the matrix proteins synthesised by pericytes displaying these different phenotypes. Stellate pericytes cultured on plastic dishes synthesised predominantly type I collagen, some type III collagen and only traces of type IV collagen. The same collagen types were secreted when nodules had formed in postconfluent cultures on plastic, and by sprouting cells plated as single cells within the collagen gel. By contrast, sprouting pericytes plated as aggregates within the collagen gel secreted increased levels of type IV collagen and reduced amounts of type I collagen. Fibronectin was synthesized by pericytes under all experimental conditions examined; thrombospondin was produced in relatively large amounts by cells grown on plastic dishes, whereas only trace amounts could be detected in the medium when the cells were cultured within a collagen gel matrix. Transmission electron microscopy revealed that pericyte aggregates within a collagen gel contained cells in close apposition surrounded by a dense extracellular matrix. In contrast, cells in the centre of a nodule on plastic appeared to be separated from each other by loose extracellular material. These results suggest that the morphological and biosynthetic phenotypes of retinal pericytes are modulated by cell-matrix and/or cell-cell interactions.


2017 ◽  
Vol 131 (5) ◽  
pp. 411-423 ◽  
Author(s):  
Bo Wang ◽  
Kevin Yao ◽  
Andrea F. Wise ◽  
Ricky Lau ◽  
Hsin-Hui Shen ◽  
...  

The regulatory role of a novel miRNA, miR-378, was determined in the development of fibrosis through repression of the MAPK1 pathway, miR-378 and fibrotic gene expression was examined in streptozotocin (STZ)-induced diabetic mice at 18 weeks or in unilateral ureteral obstruction (UUO) mice at 7 days. miR-378 transfection of proximal tubular epithelial cells, NRK52E and mesangial cells was assessed with/without endogenous miR-378 knockdown using the locked nucleic acid (LNA) inhibitor. NRK52E cells were co-transfected with the mothers against decapentaplegic homolog 3 (SMAD3) CAGA reporter and miR-378 in the presence of transforming growth factor-β (TGF-β1) was assessed. Quantitative polymerase chain reaction (qPCR) showed a significant reduction in miR-378 (P<0.05) corresponding with up-regulated type I collagen, type IV collagen and α-smooth muscle actin (SMA) in kidneys of STZ or UUO mice, compared with controls. TGF-β1 significantly increased mRNA expression of type I collagen (P<0.05), type IV collagen (P<0.05) and α-SMA (P<0.05) in NRK52E cells, which was significantly reduced (P<0.05) following miR-378 transfection and reversed following addition of the LNA inhibitor of endogenous miR-378. Overexpression of miR-378 inhibited mesangial cell expansion and proliferation in response to TGF-β1, with LNA–miR-378 transfection reversing this protective effect, associated with cell morphological alterations. The protective function of MAPK1 on miR-378 was shown in kidney cells treated with the MAPK1 inhibitor, selumetinib, which inhibited mesangial cell hypertrophy in response to TGF-β1. Taken together, these results suggest that miR-378 acts via regulation of the MAPK1 pathway. These studies demonstrate the protective function of MAPK1, regulated by miR-378, in the induction of kidney cell fibrosis and mesangial hypertrophy.


1985 ◽  
Vol 33 (7) ◽  
pp. 655-664 ◽  
Author(s):  
S Berrih ◽  
W Savino ◽  
S Cohen

The immunohistochemical detection of elements of the human thymic extracellular matrix in situ and in vitro is described. In the normal thymus, the intracapsular and intraseptal fibers were strongly labeled by anti-type I collagen antiserum. Basement membranes bordering the capsule, septae, and perivascular spaces were intensely stained by anti-type IV collagen, anti-fibronectin, and anti-laminin sera. In hyperplastic myasthenia gravis thymuses, the major changes consisted of discontinuities of the basement membrane adjacent to clusters of epithelial (keratin-containing) cells, among which an unusual connective framework (densely labeled by all the antisera) was observed. In vitro, most epithelial cells were strongly labeled by antifibronectin serum and to a lesser extent by the anti-type IV collagen and anti-laminin sera. In addition, fibronectin, laminin, and type IV collagen were detected in the intercellular spaces bordering the epithelial cells in culture. Results show that thymic epithelial cells participate in the synthesis of extracellular matrix elements, which as a result of their localization and influence on epithelial cell growth, should be regarded as constitutive components of the thymic microenvironment.


2004 ◽  
Vol 15 (10) ◽  
pp. 4467-4475 ◽  
Author(s):  
Yasuhiro Matsuoka ◽  
Hiroshi Kubota ◽  
Eijiro Adachi ◽  
Naoko Nagai ◽  
Toshihiro Marutani ◽  
...  

Hsp47 is a molecular chaperone that specifically recognizes procollagen in the endoplasmic reticulum. Hsp47-null mouse embryos produce immature type I collagen and form discontinuous basement membranes. We established Hsp47-/- embryonic stem cell lines and examined formation of basement membrane and production of type IV collagen in embryoid bodies, a model for postimplantation egg-cylinder stage embryos. The visceral endodermal cell layers surrounding Hsp47-/- embryoid bodies were often disorganized, a result that suggested abnormal function of the basement membrane under the visceral endoderm. Rate of type IV collagen secretion by Hsp47-/- cells was fourfold lower than that of Hsp47+/+ cells. Furthermore, type IV collagen secreted from Hsp47-/- cells was much more sensitive to protease digestion than was type IV collagen secreted from Hsp47+/+ cells, which suggested insufficient or incorrect triple helix formation in type IV collagen in the absence of Hsp47. These results indicate for the first time that Hsp47 is required for the molecular maturation of type IV collagen and suggest that misfolded type IV collagen causes abnormal morphology of embryoid bodies.


2019 ◽  
Vol 68 (2) ◽  
pp. 149-162 ◽  
Author(s):  
Marì Regoli ◽  
Gian Marco Tosi ◽  
Giovanni Neri ◽  
Annalisa Altera ◽  
Daniela Orazioli ◽  
...  

Idiopathic epiretinal membranes are sheets of tissue that develop in the vitreoretinal interface. They are formed by cells and extracellular matrix, and they are considered the expression of a fibrotic disorder of the eye. Confocal and immunoelectron microscopy of the extracellular matrix of excised membranes, revealed high contents of type IV collagen. It was distributed within epiretinal membranes in basement membrane-like structures associated with cells and in interstitial deposits. In both cases, type IV collagen was always associated with type I collagen. Col IV was also coupled with Col VI and laminin. At high magnification, type IV collagen immunolabelling was associated with interstitial deposits and showed a reticular appearance due to the intersection of beaded microfilaments. The microfilaments are about 12 nm in diameter with interbead distance of 30–40 nm. Cells of the epiretinal membranes showed intracellular lysosome-like bodies heavily labeled for type IV collagen suggesting an active role in membrane remodeling. Hence, type IV collagen is not necessarily always associated with basement membranes; the molecular interactions that it may develop when not incorporated in basement membranes are still unknown. It is conceivable, however, that they might have implications in the progression of epiretinal membranes and other fibrotic disorders.


1998 ◽  
Vol 4 (1) ◽  
pp. 21-26 ◽  
Author(s):  
D.F. Kallmes ◽  
G.R. Hankins ◽  
M.K. Borland ◽  
H.J. Cloft ◽  
M.E. Jensen ◽  
...  

We determined the propensity for and reversibility of transforming growth factor-ß (TGFß) binding to uncoated Guglielmi Detachable Coils (GDC) and to GDC coated with extracellular matrix (ECM) proteins. Three 1.0 centimetre samples each of uncoated GDC-18 and of GDC-18 coated with either poly-L-lysine, laminin, type I collagen, type IV collagen, fibronectin, or poly-L-lysine and laminin were prepared. These samples were immersed briefly in a solution containing I125-labelled TGFß at a concentration of 0.225 μg/ml with initial specific activity of 123.3 mCi/mg (DuPont-NEN, Billerica, MA), and were counted using a scintillation counter. Each sample was then placed in a vial containing saline, shaken for 60 seconds, and counted again. Selected samples were immersed for varying periods within the TGFß solution and counted before and after saline rinse. Samples were rinsed one week after initial rinsing and counted again. The amount of binding between coil types was compared using the Student t test. For all samples initial binding of TGFß was in the order of 60–120 pg/cm. For the pre-rinse data there were no statistically significant differences between the amount bound to any single coil coating type relative to other coatings. Compared to the initial accumulations, the amount remaining after rinsing ranged from 40% (poly-L-lysine) to 63% (poly-L-lysine with laminin), with a mean of 55% among the seven coil types. After rinsing there was more growth factor remaining on uncoated coils than on poly-L-lysine-coated coils (p=0.05), fibronectin-coated coils (p=0.01), and type IV collagen-coated coils (p=0.04). There was a trend toward greater residual growth factor on coils coated with poly-L-lysine and laminin compared to coils coated with poly-L-lysine alone (p=0.10). Delayed, second rinsing of the samples one week after initial testing demonstrated only minor incremental loss of TGFß from the coil surfaces. After five minutes of immersion, accumulation was approximately 200% greater than that noted with brief submersion, but immersions lasting over five minutes did not yield increasing levels of TGFß binding. TGFß binds to GDC coils. Binding is not improved with ECM protein-coated coils compared to uncoated coils. The absolute amount of TGFß bound to the coil will likely result in local concentrations of growth factor in the order of those required for biological activity in vivo.


2007 ◽  
Vol 196 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Toru Takahashi ◽  
Osamu Yamada ◽  
Michael J Soares ◽  
Kazuyoshi Hashizume

The bovine placenta produces an array of proteins structurally similar to pituitary prolactin (PRL). At least ten genes of the bovine placental PRL family, including bovine placental lactogen (bPL) and ten bovine PRL-related protein-I to -X (bPRP-I to -X), encode hormones/cytokines predicted to be involved in the establishment and maintenance of pregnancy. Targets and biological roles for most members of the bovine PRL family have yet to be specified. This study focused on three members of bovine PRL family, bPL, bPRP-I, and bPRP-VI. An alkaline phosphatase (AP) tagging strategy was used to monitor interactions of the ligands with their targets. AP-bPRP-I and AP-bPRP-VI specifically bound to tissue sections of the bovine placentome. AP-bPRP-I and AP-bPRP-VI binding within the placentome mimicked the distribution of the extracellular matrix (ECM). Consequently, AP fusion protein binding to individual ECM components (heparin, laminin, fibronectin, type I collagen, and type IV collagen) was evaluated. AP-bPRP-I specifically bound to type IV collagen, but not to the other ECM components. AP-bPRP-VI exhibited weak interactions with ECM components, while AP-bPL and AP did not show significant binding to any of the ECM components. Binding of AP-bPRP-I to type IV collagen was concentration-dependent, influenced by salt concentrations, and specific to the N-terminal cross-linking domain (7S) of type IV collagen but not its triple-helical domain. The interaction of bPRP-I with type IV collagen suggests that bPRP-I accumulates in the ECM where it likely acts on cells traversing the bovine placentome.


Author(s):  
Lazarina Gyoneva ◽  
Mohammad F. Hadi ◽  
Yoav Segal ◽  
Kevin D. Dorfman ◽  
Victor H. Barocas

The basement membrane is a specialized part of the extra-cellular matrix. It is usually characterized as a scaffold for epithelial cells but in some tissues it serves other, mechanical, roles [1]. The mechanical properties of the basement membrane are mainly determined by one of its main constituents — type IV collagen. Unlike the well-known fibrous type I collagen, collagen IV assembles into planar networks (Fig. 1) [2]. The α 1(IV) and α 2(IV) collagen IV chains assemble into the so-called major chain network, present in all basement membranes. The α 3(IV), α 4(IV), α 5(IV) collagen IV chains form the minor chain network which is found only in the adult basement membranes of the kidney glomerular capillaries (GBM), ocular lens (LBM), cochlea, and the testes [3]. The minor chains have a higher number of cysteine residues, allowing them to form a higher number of lateral interactions. In the minor chain network, the greater potential to interact laterally manifests in the formation of super-coils, which are rarely observed in the major chain network [4]. Increasing the number of cross-links in a polymeric material is known to increase material stiffness; therefore, it is believed that the minor chain network confers basement membranes with additional strength and stability [5]. In the hereditary disease Alport syndrome, a mutation causes the absence of the minor chain network. The GBM and LBM of Alport patients appear weakened and unable to meet their mechanical demands, further supporting this theory [6]. The objective of this study was to evaluate the importance of cross-linking in the minor chains for the mechanical properties of type IV collagen networks, specifically in the GBM and LBM where the absence of the minor chains has an observed mechanical effect.


1985 ◽  
Vol 73 (1) ◽  
pp. 19-32
Author(s):  
W.C. Young ◽  
I.M. Herman

We utilized fluorescence microscopy and affinity-purified antibodies to probe the form and function of cytoplasmic actin in endothelial cells (EC) recovering from injury and grown on extracellular matrices in vitro. Bovine aortic EC were seeded onto glass microscope coverslips that had been coated with either BSA, fibronectin, type I and III (interstitial) collagens, type IV (basement membrane) collagen or gelatin. After EC that had been grown on glass, glass-BSA or extracellular matrix-coated coverslips reached confluence, a 300–400 micron zone of cells was mechanically removed to stimulate EC migration and proliferation. Post-injury EC movements were monitored with time-lapse, phase-contrast videomicrography before fixation for actin localization with fluorescence microscopy using affinity-purified antibodies. We found that the number of stress fibres within EC was inversely proportional to the rate of movement; and, the rates of movement for EC grown on glass or glass-BSA were approximately eight times faster than EC grown on gelatin or type IV collagen (X velocity = 0.5 micron/min versus 0.06 micron/min). EC movements on fibronectin and interstitial collagens were similar (X velocity = 0.2 micron/min). These results suggest that extracellular matrix molecules modulate EC stress fibre expression, thereby producing alterations in the cytoskeleton and the resultant EC movements that follow injury in vitro. Moreover, the induction of stress fibres in the presence of basement membrane (type IV) collagen may explain the failure of aortic EC to migrate and repopulate wounded regions of intima during atherogenesis in vivo.


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