scholarly journals Plumbagin Alleviates Capillarization of Hepatic Sinusoids In Vitro by Downregulating ET-1, VEGF, LN, and Type IV Collagen

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Guiyu Li ◽  
Yue Peng ◽  
Tiejian Zhao ◽  
Jiyong Lin ◽  
Xuelin Duan ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Basement Membrane ◽  
Molecular Mechanisms ◽  
Type Iv Collagen ◽  
Vascular Endothelial ◽  
Liver Sinusoidal Endothelial Cells ◽  
Collagen Mrna ◽  
Type Iv ◽  
Endothelial Growth Factor

Critical roles for liver sinusoidal endothelial cells (LSECs) in liver fibrosis have been demonstrated, while little is known regarding the underlying molecular mechanisms of drugs delivered to the LSECs. Our previous study revealed that plumbagin plays an antifibrotic role in liver fibrosis. In this study, we investigated whether plumbagin alleviates capillarization of hepatic sinusoids by downregulating endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), laminin (LN), and type IV collagen on leptin-stimulated LSECs. We found that normal LSECs had mostly open fenestrae and no organized basement membrane. Leptin-stimulated LSECs showed the formation of a continuous basement membrane with few open fenestrae, which were the features of capillarization. Expression of ET-1, VEGF, LN, and type IV collagen was enhanced in leptin-stimulated LSECs. Plumbagin was used to treat leptin-stimulated LSECs. The sizes and numbers of open fenestrae were markedly decreased, and no basement membrane production was found after plumbagin administration. Plumbagin decreased the levels of ET-1, VEGF, LN, and type IV collagen in leptin-stimulated LSECs. Plumbagin promoted downregulation of ET-1, VEGF, LN, and type IV collagen mRNA. Altogether, our data reveal that plumbagin reverses capillarization of hepatic sinusoids by downregulation of ET-1, VEGF, LN, and type IV collagen.

scholarly journals Formation of basement membranes in the embryonic kidney: an immunohistological study

1981 ◽  
Vol 91 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Ekblom
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Basement Membranes ◽  
Glomerular Endothelial Cell ◽  
Type Iv ◽  
Endothelial Cell Differentiation ◽  
Inductive Interaction ◽  
Immunohistological Study

Specific antibodies to laminin, type IV collagen, basement-membrane proteoglycan, and fibronectin have been used in immunofluorescence microscopy to study the development of basement membranes of the embryonic kidney. Kidney tubules are known to form from the nephrogenic mesenchyme as a result of an inductive tissue interaction. This involves a change in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses fibronectin but no detectable laminin, type IV collagen, or basement-membrane proteoglycan. During the inductive interaction, basement-membrane specific components (laminin, type IV collagen, basement membrane proteoglycan) become detectable in the induced area, whereas fibronectin is lost. While the differentiation to epithelial cells of the kidney requires an inductive interaction, the development of the vasculature seems to involve an ingrowth of cells which throughout development deposits basement-membrane specific components, as well as fibronectin. These cells form the endothelium and possibly also the mesangium of the glomerulus, and contribute to the formation of the glomerular basement membrane. An analysis of differentiation of the kidney mesenchyme in vitro in the absence of circulation supports these conclusions. Because a continuity with vasculature is required for glomerular endothelial cell differentiation, it is possible that these cells are derived from outside vasculature.

scholarly journals Cells that emerge from embryonic explants produce fibers of type IV collagen.

1985 ◽  
Vol 101 (4) ◽  
pp. 1175-1181 ◽  
Author(s):  
J M Chen ◽  
C D Little
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Polyclonal Antibodies ◽  
Mouse Lung ◽  
Embryonic Mouse ◽  
Type Iv ◽  
Collagen Substratum

Double immunofluorescence staining experiments designed to examine the synthesis and deposition of collagen types I and IV in cultured explants of embryonic mouse lung revealed the presence of connective tissue-like fibers that were immunoreactive with anti-type IV collagen antibodies. This observation is contrary to the widely accepted belief that type IV collagen is found only in sheet-like arrangements beneath epithelia or as a sheath-like layer enveloping bundles of nerve or muscle cells. The extracellular matrix produced by cells that migrate from embryonic mouse lung rudiments in vitro was examined by double indirect immunofluorescence microscopy. Affinity-purified monospecific polyclonal antibodies were used to examine cells after growth on glass or native collagen substrata. The data show that embryonic mesenchymal cells can produce organized fibers of type IV collagen that are not contained within a basement membrane, and that embryonic epithelial cells deposit fibers and strands of type IV collagen beneath their basal surface when grown on glass; however, when grown on a rat tail collagen substratum the epithelial cells produce a fine meshwork. To our knowledge this work represents the first report that type IV collagen can be organized by cells into a fibrous extracellular matrix that is not a basement membrane.

Abrogation of PDGFR by STI571: Effect on PDGF/VEGF in HNSCC

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P89-P89
Author(s):  
Gregor Bran ◽  
Jens Stern-Straeter ◽  
Ulrich R. Goessler ◽  
Birgit Bran ◽  
Karl Hoermann ◽  
...  
Keyword(s):  
Cell Lines ◽  
Tyrosine Kinases ◽  
Molecular Mechanisms ◽  
Vascular Endothelial ◽  
Elisa Technique ◽  
Tumor Types ◽  
Endothelial Growth Factor ◽  
In Vitro Treatment ◽  
Hnscc Cell

Problem Angiogenesis is increased in head and neck squamous cell carcinoma (HNSCC), and correlates with tumor progression and metastasis. Vascular endothelial growth factor (VEGF) has been shown to be a key regulator of angiogenesis. Microvascular density is known to correlate with metastasis and aggressiveness. PDGF and PDGFR are expressed by many tumor types, including HNSCC. The PDGF/PDGFR-System is believed to play a pivotal role in tumorigenesis. The compound STI571 (Imatinib mesylate, Gleevec) inhibits PDGFR tyrosine kinases. In this study, we seek to determine whether targeting PDGFR signalling in HNSCC cell lines may affect expression and secretion of PDGF as well as VEGF in vitro. Methods Established human HNSCC cell lines were incubated with STI571 of different concentrations for 24h and 72h. PDGF and VEGF concentrations were determined by an ELISA technique, and gene expression was analyzed by RTPCR. Results In vitro treatment of HNSCC cell lines with STI571 resulted in a significant reduction of expression and secretion of PDGF and VEGF. We also observed a dose related effect for VEGF synthesis. Conclusion The results in this study suggest, that inhibition of PDGFR using STI571 might have an antitumor effect mediated in part by inhibition of VEGF-induced angiogenesis in HNSCC. Further studies need to be conducted to improve understanding of the molecular mechanisms. Significance Our study indicates that STI571 might play a role in establishing new therapeutic strategies against HNSCC.

scholarly journals Assembly of the exogenous extracellular matrix during basement membrane formation by alveolar epithelial cells in vitro

2000 ◽  
Vol 113 (5) ◽  
pp. 859-868 ◽  
Author(s):  
A. Furuyama ◽  
K. Mochitate
Keyword(s):  
Epithelial Cells ◽  
Basement Membrane ◽  
Type Iv Collagen ◽  
Alveolar Epithelial Cells ◽  
Coarse Mesh ◽  
Lamina Densa ◽  
Alveolar Epithelial ◽  
Type Iv ◽  
Laminin 1

We found that immortalized alveolar type II epithelial cells (SV40-T2 cells) that were cultured on dense fibrillar collagen supplemented with Matrigel gel formed a thin and continuous lamina densa beneath them. Immunohistochemical analysis of laminin-1, type IV collagen, entactin (nidogen) and perlecan in the culture indicated that all these components were integrated into a sheet structure of basement membrane beneath the cells. Analysis of the temporal and spatial distribution of the basement membrane macromolecules revealed that the initial deposits of laminin-1 and entactin were significantly greater in area in the presence of Matrigel. These globular deposits and the coarse mesh of basement membrane macromolecules developed into a flat membranous basement membrane. In the absence of Matrigel, the SV40-T2 cells failed to form a continuous lamina densa, and the deposits stayed in the coarse mesh. The major biotinylated Matrigel components that were integrated into the basement membrane were laminin-1 and entactin. Furthermore, SV40-T2 cells supplemented with exogenous laminin-1 alone as well as laminin-1 contaminated with entactin formed a continuous lamina densa. These results indicate that the laminin-1 and entactin supplied from the Matrigel were incorporated into a basement membrane beneath the SV40-T2 cells, and contributed to the formation of basement membrane. Therefore, we concluded that the alveolar epithelial cells synthesize laminin-1, entactin, type IV collagen, and perlecan, but that they also needed to assemble exogenous laminin-1 into the basement membrane to complete its formation in vitro.

Macromolecular organization of basement membrane laminin

1991 ◽  
Vol 49 ◽  
pp. 176-177
Author(s):  
Peter D. Yurchenco
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Embryonal Carcinoma ◽  
Basement Membranes ◽  
Carcinoma Cells ◽  
Structural Studies ◽  
Type Iv ◽  
Polypeptide Chains ◽  
Macromolecular Organization

Laminin isoforms are major structural and cell-interacting components of basement membranes. The most extensively studied isoform of this glycoprotein (800 kDa) is murine EHS laminin which consists of three polypeptide chains (A,B1,B2) disulfide linked to form a flexible four-armed molecule which in turn is often complexed to entactin, a smaller dumbell-shaped sulfated glycoprotein. One of the functions proposed for laminin is selfassembly into a polymer that constitutes a major part of basement membrane architecture. The principal evidence for this hypothesis has derived from biochemical and structural studies of laminin polymerization in vitro. Embryonal carcinoma cells (M1536B3) grown in suspension culture will differentiate into multicellular spherules that produce basement membrane cores rich in laminin/entactin but devoid of type IV collagen, a characteristic of some basement membranes of developing tissues. We now report that these cores share the same structural/biochemical features with reconstituted laminin polymers.

scholarly journals Basement membrane structure in situ: evidence for lateral associations in the type IV collagen network.

1987 ◽  
Vol 105 (6) ◽  
pp. 2559-2568 ◽  
Author(s):  
P D Yurchenco ◽  
G C Ruben
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Thin Sheet ◽  
Great Part ◽  
Molecular Architecture ◽  
Branch Points ◽  
Collagen Network ◽  
Type Iv

To determine molecular architecture of the type IV collagen network in situ, the human amniotic basement membrane has been studied en face in stereo relief by high resolution unidirectional metal shadow casting aided by antibody decoration and morphometry. The appearance of the intact basement membrane is that of a thin sheet in which there are regions of branching strands. Salt extraction further exposes these strands to reveal an extensive irregular polygonal network that can be specifically decorated with gold-conjugated anti-type IV collagen antibody. At high magnification one sees that the network, which contains integral (9-11 nm net diameter) globular domains, is formed in great part by lateral association of monomolecular filaments to form branching strands of variable but narrow diameters. Branch points are variably spaced apart by an average of 45 nm with 4.4 globular domains per micron of strand length. Monomolecular filaments (1.7-nm net diameter) often appear to twist around each other along the strand axis; we propose that super helix formation is an inherent characteristic of lateral assembly. A previous study (Yurchenco, P. D., and H. Furthmayr. 1984. Biochemistry. 23:1839) presented evidence that purified murine type IV collagen dimers polymerize to form polygonal arrays of laterally as well as end-domain-associated molecules. The architecture of this polymer is similar to the network seen in the amnion, with lateral binding a major contributor to each. Thus, to a first approximation, isolated type IV collagen can reconstitute in vitro the polymeric molecular architecture it assumes in vivo.

Abstract 387: Role of Aldehyde Dehydrogenase (aldh) 2 in Angiotensin II-induced Decrease in Angiogenesis of Coronary Endothelial Cells

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Bipradas Roy ◽  
Suresh S Palaniyandi
Keyword(s):  
Angiotensin Ii ◽  
Aldehyde Dehydrogenase ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Tube Formation ◽  
Vascular Endothelial ◽  
Ang Ii ◽  
Endothelial Growth Factor

Diabetes-induced coronary endothelial cell (CEC) dysfunction following defective angiogenesis is reported in cardiovascular diseases (CVD). Angiotensin II (Ang II), a vasoactive molecule, is upregulated in diabetes. However, the underlying molecular mechanisms of Ang II-induced CEC dysfunction are not fully understood. Aldehyde dehydrogenase (ALDH) 2 is cytoprotective in diabetic CVD. Thus, we hypothesize that ALDH2 improves Ang II-mediated defective CEC angiogenesis. To test our hypothesis, we treated the cultured mouse CECs with Ang II (0.1, 1 and 10 μM) for 2 and 4 hours. Next, we treated CEC with Alda-1 (10 μM), an ALDH2 activator or disulfiram (2.5 μM), an ALDH2 inhibitor, before challenging MCECs with Ang II. We found that Ang II attenuated tube formation (P<0.05 vs control) which indicates in vitro angiogenesis. Next, we found that Ang II have downregulated the mRNA expressions of vascular endothelial growth factor receptor VEGFR1 (p<0.05) and upregulated angiotensin II type-2 receptor (AT2R) (P<0.05) in cultured CECs compared to controls. ALDH2 inhibition with disulfiram potentiated Ang II-induced decrease in angiogenesis (P<0.005) by decreasing the expressions of VEGFR1 (P<0.0005) and increasing the expression of AT2R (p<0.05) relative to Ang II alone. Additionally, activation of ALDH2 activity with Alda-1 rescued Ang II-induced decrease in angiogenesis (P<0.05) by increasing the expression of VEGFR1 (P<0.05) and decreasing the expression of AT2R (P<0.05) relative to Ang II alone. Finally, we conclude that ALDH2 can be an important therapeutic target to improve coronary angiogenesis in diabetic CVD.

scholarly journals Characterization of the Hemorrhagic Reaction Caused by Vibrio vulnificus Metalloprotease, a Member of the Thermolysin Family

1998 ◽  
Vol 66 (10) ◽  
pp. 4851-4855 ◽  
Author(s):  
Shin-ichi Miyoshi ◽  
Hiromi Nakazawa ◽  
Koji Kawata ◽  
Ken-ichi Tomochika ◽  
Kazuo Tobe ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Vibrio Vulnificus ◽  
Vascular Endothelial Cells ◽  
Human Pathogen ◽  
Membrane Breakdown ◽  
Type Iv ◽  
Hemorrhagic Activity

ABSTRACT Vibrio vulnificus is an opportunistic human pathogen causing wound infections and septicemia, characterized by hemorrhagic and edematous damage to the skin. This human pathogen secretes a metalloprotease (V. vulnificus protease [VVP]) as an important virulence determinant. When several bacterial metalloproteases including VVP were injected intradermally into dorsal skin, VVP showed the greatest hemorrhagic activity. The level of the in vivo hemorrhagic activity of the bacterial metalloproteases was significantly correlated with that of the in vitro proteolytic activity for the reconstituted basement membrane gel. Of two major basement membrane components (laminin and type IV collagen), only type IV collagen was easily digested by VVP. Additionally, the immunoglobulin G antibody against type IV collagen, but not against laminin, showed sufficient protection against the hemorrhagic reaction caused by VVP. Capillary vessels are known to be stabilized by binding of the basal surface of vascular endothelial cells to the basement membrane. Therefore, specific degradation of type IV collagen may cause destruction of the basement membrane, breakdown of capillary vessels, and leakage of blood components including erythrocytes.

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