Dataset Information

Integrin alpha8beta1 regulates adhesion, migration and proliferation of human intestinal crypt cells via a predominant RhoA/ROCK-dependent mechanism.

ABSTRACT:

Background

Integrins are transmembrane alphabeta heterodimer receptors that function as structural and functional bridges between the cytoskeleton and ECM (extracellular matrix) molecules. The RGD (arginine-glycine-aspartate tripeptide motif)-dependent integrin alpha8beta1 has been shown to be involved in various cell functions in neuronal and mesenchymal-derived cell types. Its role in epithelial cells remains unknown.

Results

Integrin alpha8beta1 was found to be expressed in the crypt cell population of the human intestine but was absent from differentiating and mature epithelial cells of the villus. The function of alpha8beta1 in epithelial crypt cells was investigated at the cellular level using normal HIECs (human intestinal epithelial cells). Specific knockdown of alpha8 subunit expression using an shRNA (small-hairpin RNA) approach showed that alpha8beta1 plays important roles in RGD-dependent cell adhesion, migration and proliferation via a RhoA/ROCK (Rho-associated kinase)-dependent mechanism as demonstrated by active RhoA quantification and pharmacological inhibition of ROCK. Moreover, loss of alpha8beta1, through RhoA/ROCK, impairs FA (focal adhesion) complex integrity as demonstrated by faulty vinculin recruitment.

Conclusions

Integrin alpha8beta1 is expressed in epithelial cells. In intestinal crypt cells, alpha8beta1 is closely involved in the regulation of adhesion, migration and cell proliferation via a predominant RhoA/ROCK-dependent mechanism. These results suggest an important role for this integrin in intestinal crypt cell homoeostasis.

SUBMITTER: Benoit YD

PROVIDER: S-EPMC2782361 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Integrin alpha8beta1 regulates adhesion, migration and proliferation of human intestinal crypt cells via a predominant RhoA/ROCK-dependent mechanism.

Benoit Yannick D YD Lussier Carine C Ducharme Pierre-Alexandre PA Sivret Sophie S Schnapp Lynn M LM Basora Nuria N Beaulieu Jean-François JF

Biology of the cell 20090914 12

<h4>Background</h4>Integrins are transmembrane alphabeta heterodimer receptors that function as structural and functional bridges between the cytoskeleton and ECM (extracellular matrix) molecules. The RGD (arginine-glycine-aspartate tripeptide motif)-dependent integrin alpha8beta1 has been shown to be involved in various cell functions in neuronal and mesenchymal-derived cell types. Its role in epithelial cells remains unknown.<h4>Results</h4>Integrin alpha8beta1 was found to be expressed in the ...[more]

PMID: 19527220

Similar Datasets

Project description:BackgroundFibronectin (FN) assembly into an insoluble fibrillar matrix is a crucial step in many cell responses to extracellular matrix (ECM) properties, especially with regards to the integrin-related mechanosensitive signaling pathway. We have previously reported that the silencing of expression of integrin-linked kinase (ILK) in human intestinal epithelial crypt (HIEC) cells causes significant reductions in proliferation and spreading through concomitantly acquired impairment of soluble FN deposition. These defects in ILK-depleted cells are rescued by growth on exogenous FN. In the present study we investigated the contribution of ILK in the fibrillogenesis of FN and its relation to integrin-actin axis signaling and organization.ResultsWe show that de novo fibrillogenesis of endogenous soluble FN is ILK-dependent. This function seemingly induces the assembly of an ECM that supports increased cytoskeletal tension and the development of a fully spread contractile cell phenotype. We observed that HIEC cell adhesion to exogenous FN or collagen-I (Col-I) is sufficient to restore fibrillogenesis of endogenous FN in ILK-depleted cells. We also found that optimal engagement of the Ras homolog gene family member A (RhoA) GTPase/Rho-associated kinase (ROCK-1, ROCK-2)/myosin light chain (MLC) pathway, actin ventral stress fiber formation, and integrin adhesion complex (IAC) maturation rely primarily upon the cell's capacity to execute FN fibrillogenesis, independent of any significant ILK input. Lastly, we confirm the integrin α5β1 as the main integrin responsible for FN assembly, although in ILK-depleted cells αV-class integrins expression is needed to allow the rescue of FN fibrillogenesis on exogenous substrate.ConclusionOur study demonstrates that ILK specifically induces the initiation of FN fibrillogenesis during cell spreading, which promotes RhoA/ROCK-dependent cell contractility and maturation of the integrin-actin axis structures. However, the fibrillogenesis process and its downstream effect on RhoA signaling, cell contractility and spreading are ILK-independent in human intestinal epithelial crypt cells.

Project description:BackgroundThe pathogenesis of benign prostatic hyperplasia (BPH) has not been fully elucidated. Ras homology family member A (RhoA) plays an important role in regulating cell cytoskeleton, growth and fibrosis. The role of RhoA in BPH remains unclear.MethodsThis study aimed to clarify the expression, functional activity and mechanism of RhoA in BPH. Human prostate tissues, human prostate cell lines, BPH rat model were used. Cell models of RhoA knockdown and overexpression were generated. Immunofluorescence staining, quantitative real time PCR (qRT-PCR), Western blotting, cell counting kit-8 (CCK-8), flow cytometry, phalloidine staining, organ bath study, gel contraction assay, protein stability analysis, isolation and extraction of nuclear protein and cytoplasmic protein were performed.ResultsIn this study we found that RhoA was localized in prostate stroma and epithelial compartments and was up-regulated in both BPH patients and BPH rats. Functionally, RhoA knockdown induced cell apoptosis and inhibited cell proliferation, fibrosis, epithelial-mesenchymal transformation (EMT) and contraction. Consistently, overexpression of RhoA reversed all aforementioned processes. More importantly, we found that β-catenin and the downstream of Wnt/β-catenin signaling, including C-MYC, Survivin and Snail were up-regulated in BPH rats. Downregulation of RhoA significantly reduced the expression of these proteins. Rho kinase inhibitor Y-27632 also down-regulated β-catenin protein in a concentration-dependent manner. However, overexpression of β-catenin did not affect RhoA-ROCK levels, suggesting that β-catenin was the downstream of RhoA-ROCK regulation. Further data suggested that RhoA increased nuclear translocation of β-catenin and up-regulated β-catenin expression by inhibiting its proteasomal degradation, thereby activating Wnt/β-catenin signaling. Overexpression of β-catenin partially reversed the changes in cell growth, fibrosis and EMT except cell contraction caused by RhoA downregulation. Finally, Y-27632 partially reversed prostatic hyperplasia in vivo, further suggesting the potential of RhoA-ROCK signaling in BPH treatment.ConclusionOur novel data demonstrated that RhoA regulated both static and dynamic factors of BPH, RhoA-ROCK-β-catenin signaling axis played an important role in the development of BPH and might provide more possibilities for the formulation of subsequent clinical treatment strategies.

Dataset Information

Integrin alpha8beta1 regulates adhesion, migration and proliferation of human intestinal crypt cells via a predominant RhoA/ROCK-dependent mechanism.

Background

Results

Conclusions

Publications

Integrin alpha8beta1 regulates adhesion, migration and proliferation of human intestinal crypt cells via a predominant RhoA/ROCK-dependent mechanism.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets