Rho-family small GTPases are involved in forskolin-induced cell-cell contact formation of renal glomerular podocytes in vitro

2007 ◽  
Vol 328 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Shuang-yan Gao ◽  
Chun-yu Li ◽  
Tetsuya Shimokawa ◽  
Takehiro Terashita ◽  
Seiji Matsuda ◽  
...  
2001 ◽  
Vol 114 (4) ◽  
pp. 695-707 ◽  
Author(s):  
I. Grosheva ◽  
M. Shtutman ◽  
M. Elbaum ◽  
A.D. Bershadsky

The molecular basis for contact inhibition of cell locomotion is still largely unknown. Cadherins, the major receptors mediating cell-cell adhesion, associate in the cytoplasm with armadillo family proteins, including beta- and gamma-catenin and p120 catenin (p120ctn). E-cadherin-mediated contact formation was shown to inhibit cellular motility. We examine whether p120ctn may have a role in this regulation. We show here that overexpression of p120ctn in fibroblasts and epithelial cells induces pronounced changes in cell shape, motility and adhesion to the extracellular matrix. p120ctn-transfected cells display increased filopodial/lamellipodial activity, decreased contractility and focal adhesion formation, and augmented migratory ability. These effects of p120ctn are mediated by small GTPases of the Rho family. Direct assessment of the activity of these GTPases in cells expressing a 5-fold higher level of p120ctn as compared to non-transfected control cells revealed significant augmentation of Cdc42 and Rac activity. Moreover, co-transfection of p120ctn with dominant-negative Cdc42 and Rac, or constitutively active Rho suppressed morphological effects of p120ctn. Confocal immunofluorescence visualization of the distribution of endogenous p120ctn in dense cultures showed that formation of cadherin-mediated cell-cell contacts is accompanied by sequestering of p120ctn to the junction regions. In sparse cultures p120ctn is distributed over the cytoplasm. Co-transfection with an excess of E-cadherin leads to sequestration of exogenous p120ctn to cell-cell junctions or to small cadherin-containing vesicles, and abolishes p120ctn effects on cell morphology. Thus, p120ctn may couple the formation and disruption of cadherin-mediated contacts with regulation of cell motility by triggering pathway(s) affecting Rho family GTPases.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-wen Cheng ◽  
Li-xia Duan ◽  
Yang Yu ◽  
Pu Wang ◽  
Jia-le Feng ◽  
...  

Abstract Background Mesenchymal stem cells (MSCs) play a crucial role in cancer development and tumor resistance to therapy in prostate cancer, but the influence of MSCs on the stemness potential of PCa cells by cell–cell contact remains unclear. In this study, we investigated the effect of direct contact of PCa cells with MSCs on the stemness of PCa and its mechanisms. Methods First, the flow cytometry, colony formation, and sphere formation were performed to determine the stemness of PCaMSCs, and the expression of stemness-related molecules (Sox2, Oct4, and Nanog) was investigated by western blot analysis. Then, we used western blot and qPCR to determine the activity levels of two candidate pathways and their downstream stemness-associated pathway. Finally, we verified the role of the significantly changed pathway by assessing the key factors in this pathway via in vitro and in vivo experiments. Results We established that MSCs promoted the stemness of PCa cells by cell–cell contact. We here established that the enhanced stemness of PCaMSCs was independent of the CCL5/CCR5 pathway. We also found that PCaMSCs up-regulated the expression of Notch signaling-related genes, and inhibition of Jagged1-Notch1 signaling in PCaMSCs cells significantly inhibited MSCs-induced stemness and tumorigenesis in vitro and in vivo. Conclusions Our results reveal a novel interaction between MSCs and PCa cells in promoting tumorigenesis through activation of the Jagged1/Notch1 pathway, providing a new therapeutic target for the treatment of PCa.


1989 ◽  
Vol 52 (6) ◽  
pp. 1958-1961 ◽  
Author(s):  
Volker Seybold ◽  
Harald Rösner ◽  
Christian Greis ◽  
Eva Beck ◽  
Hinrich Rahmann

2021 ◽  
Author(s):  
Mattias Malaguti ◽  
Rosa Portero Migueles ◽  
Jennifer Annoh ◽  
Daina Sadurska ◽  
Guillaume Blin ◽  
...  

ABSTRACTCell-cell interactions govern differentiation and cell competition in pluripotent cells during early development, but the investigation of such processes is hindered by a lack of efficient analysis tools. Here we introduce SyNPL: clonal pluripotent stem cell lines which employ optimised Synthetic Notch (SynNotch) technology to report cell-cell interactions between engineered “sender” and “receiver” cells in cultured pluripotent cells and chimaeric mouse embryos. A modular design makes it straightforward to adapt the system for programming differentiation decisions non-cell-autonomously in receiver cells in response to direct contact with sender cells. We demonstrate the utility of this system by enforcing neuronal differentiation at the boundary between two cell populations. In summary, we provide a new tool which could be used to identify cell interactions and to profile changes in gene or protein expression that result from direct cell-cell contact with defined cell populations in culture and in early embryos, and which can be adapted to generate synthetic patterning of cell fate decisions.


1996 ◽  
Vol 132 (1) ◽  
pp. 181-193 ◽  
Author(s):  
S Yoshida ◽  
A Fujisawa-Sehara ◽  
T Taki ◽  
K Arai ◽  
Y Nabeshima

Myogenic cells provide excellent in vitro models for studying the cell growth and differentiation. In this study we report that lysophosphatidic acid (LPA), a bioactive phospholipid contained in serum, stimulates the growth and inhibits the differentiation of mouse C2C12 myoblast cells, in a distinct manner from basic fibroblast growth factor (bFGF) whose mitotic and anti-differentiation actions have been well investigated. These actions of LPA were both blocked by pertussis toxin, suggesting the involvement of Gi class of G proteins, whereas bFGF acts through receptor tyrosine kinases. Detailed analysis revealed that LPA and bFGF act differently in regulating the myogenic basic helix-loop-helix (bHLH) proteins, the key players in myogenic differentiation process. LPA stimulates the proliferation of undifferentiated myoblasts allowing the continued expression of MyoD, but in contrast, bFGF does so with the MyoD expression suppressed at the mRNA level. Both compounds maintain the myf-5 expression, and suppress the myogenin expression. In addition, while LPA did not inhibit cell-cell contact-induced differentiation, bFGF strongly inhibited this process. Furthermore, LPA and bFGF act cooperatively in their mitogenic and anti-differentiation abilities. These findings indicate that LPA and bFGF differently stimulate intracellular signaling pathways, resulting in proliferating myoblasts each bearing a distinct expression pattern of myogenic bHLH proteins and distinct differentiation potentials in response to cell-cell contact, and illustrate the biological significance of Gi-mediated and tyrosine kinase-mediated signals.


2012 ◽  
Vol 23 (11) ◽  
pp. 2076-2091 ◽  
Author(s):  
Qingwen Wan ◽  
Jing Liu ◽  
Zhen Zheng ◽  
Huabin Zhu ◽  
Xiaogang Chu ◽  
...  

Cell–cell contact formation following cadherin engagement requires actomyosin contraction along the periphery of cell–cell contact. The molecular mechanisms that regulate myosin activation during this process are not clear. In this paper, we show that two polarity proteins, partitioning defective 3 homologue (Par3) and mammalian homologues of Drosophila Lethal (2) Giant Larvae (Lgl1/2), antagonize each other in modulating myosin II activation during cell–cell contact formation in Madin-Darby canine kidney cells. While overexpression of Lgl1/2 or depletion of endogenous Par3 leads to enhanced myosin II activation, knockdown of Lgl1/2 does the opposite. Intriguingly, altering the counteraction between Par3 and Lgl1/2 induces cell–cell internalization during early cell–cell contact formation, which involves active invasion of the lateral cell–cell contact underneath the apical-junctional complexes and requires activation of the Rho–Rho-associated, coiled-coil containing protein kinase (ROCK)–myosin pathway. This is followed by predominantly nonapoptotic cell-in-cell death of the internalized cells and frequent aneuploidy of the host cells. Such effects are reminiscent of entosis, a recently described process observed when mammary gland epithelial cells were cultured in suspension. We propose that entosis could occur without matrix detachment and that overactivation of myosin or unbalanced myosin activation between contacting cells may be the driving force for entosis in epithelial cells.


1994 ◽  
Vol 160 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Masanobu Nanno ◽  
Masahiro Hata ◽  
Hideki Yagi ◽  
Tsunetoshi Itoh ◽  
Hideyuki Doi ◽  
...  

2011 ◽  
Vol 22 (14) ◽  
pp. 2509-2519 ◽  
Author(s):  
Jian J. Liu ◽  
Rebecca A. Stockton ◽  
Alexandre R. Gingras ◽  
Ararat J. Ablooglu ◽  
Jaewon Han ◽  
...  

Activation of Rap1 small GTPases stabilizes cell–cell junctions, and this activity requires Krev Interaction Trapped gene 1 (KRIT1). Loss of KRIT1 disrupts cardiovascular development and causes autosomal dominant familial cerebral cavernous malformations. Here we report that native KRIT1 protein binds the effector loop of Rap1A but not H-Ras in a GTP-dependent manner, establishing that it is an authentic Rap1-specific effector. By modeling the KRIT1–Rap1 interface we designed a well-folded KRIT1 mutant that exhibited a ∼40-fold-reduced affinity for Rap1A and maintained other KRIT1-binding functions. Direct binding of KRIT1 to Rap1 stabilized endothelial cell–cell junctions in vitro and was required for cardiovascular development in vivo. Mechanistically, Rap1 binding released KRIT1 from microtubules, enabling it to locate to cell–cell junctions, where it suppressed Rho kinase signaling and stabilized the junctions. These studies establish that the direct physical interaction of Rap1 with KRIT1 enables the translocation of microtubule-sequestered KRIT1 to junctions, thereby supporting junctional integrity and cardiovascular development.


1991 ◽  
Vol 112 (3) ◽  
pp. 479-490 ◽  
Author(s):  
M G Lampugnani ◽  
M Resnati ◽  
E Dejana ◽  
P C Marchisio

This paper shows that, in confluent human umbilical vein endothelial cell (EC) monolayers, the integrin heterodimers alpha 2 beta 1 and alpha 5 beta 1, but not other members of the beta 1 subfamily, are located at cell-cell contact borders and not at cellular free edges. Also the alpha v chain, but not its most common partner beta 3, that is widely expressed in EC cell-matrix junctions, is found at cell-cell borders. In EC monolayers, the putative ligands of alpha 2 beta 1 and alpha 5 beta 1 receptors, i.e., laminin, collagen type IV, and fibronectin, are also organized in strands corresponding to cell-cell borders. The location of the above integrin receptors is not an artifact of in vitro culture since it has been noted also in explanted islets of the native umbilical vein endothelium. The integrins alpha 2 beta 1 and alpha 5 beta 1 play a role in the maintenance of endothelial monolayer continuity in vitro. Indeed, specific antibodies to alpha 2 beta 1, alpha 5 beta 1, and the synthetic peptide GRGDSP alter its continuity without any initial cell detachment. Moreover, antibodies to alpha 5 beta 1 increase the permeation of macromolecules across confluent EC monolayers. In contrast beta 3 antibodies were ineffective. It is suggested that the relocation of integrins to cell-cell borders is a feature of cells programmed to form polarized monolayers since integrins have a different distribution in nonpolar confluent dermal fibroblasts. The conclusion is that some members of the integrin superfamily collaborate with other intercellular molecules to form lateral junctions and to control both the monolayer integrity and the permeability properties of the vascular endothelial lining. This also suggest that integrins are adhesion molecules provided with a unique biochemical adaptability to different biological functions.


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