scholarly journals Region-Specific Microtubule Transport in Motile Cells

2000 ◽  
Vol 151 (5) ◽  
pp. 1003-1012 ◽  
Author(s):  
Anne-Marie C. Yvon ◽  
Patricia Wadsworth

Photoactivation and photobleaching of fluorescence were used to determine the mechanism by which microtubules (MTs) are remodeled in PtK2 cells during fibroblast-like motility in response to hepatocyte growth factor (HGF). The data show that MTs are transported during cell motility in an actomyosin-dependent manner, and that the direction of transport depends on the dominant force in the region examined. MTs in the leading lamella move rearward relative to the substrate, as has been reported in newt cells (Waterman-Storer, C.M., and E.D. Salmon. 1997. J. Cell Biol. 139:417–434), whereas MTs in the cell body and in the retraction tail move forward, in the direction of cell locomotion. In the transition zone between the peripheral lamella and the cell body, a subset of MTs remains stationary with respect to the substrate, whereas neighboring MTs are transported either forward, with the cell body, or rearward, with actomyosin retrograde flow. In addition to transport, the photoactivated region frequently broadens, indicating that individual marked MTs are moved either at different rates or in different directions. Mark broadening is also observed in nonmotile cells, indicating that this aspect of transport is independent of cell locomotion. Quantitative measurements of the dissipation of photoactivated fluorescence show that, compared with MTs in control nonmotile cells, MT turnover is increased twofold in the lamella of HGF-treated cells but unchanged in the retraction tail, demonstrating that microtubule turnover is regionally regulated.

2004 ◽  
Vol 287 (4) ◽  
pp. G886-G898 ◽  
Author(s):  
Ann M. Hopkins ◽  
Matthias Bruewer ◽  
G. Thomas Brown ◽  
A’Drian A. Pineda ◽  
Julie J. Ha ◽  
...  

Superficial wounds in the gastrointestinal tract rapidly reseal by coordinated epithelial cell migration facilitated by cytokines such as hepatocyte growth factor (HGF)/scatter factor released in the wound vicinity. However, the mechanisms by which HGF promotes physiological and pathophysiologic epithelial migration are incompletely understood. Using in vitro models of polarized T84 and Caco-2 intestinal epithelia, we report that HGF promoted epithelial spreading and RhoA GTPase activation in a time-dependent manner. Inducible expression of enhanced green fluorescent protein-tagged dominant-negative RhoA significantly attenuated HGF-induced spreading. HGF expanded a zone of partially flattened cells behind the wound edge containing basal F-actin fibers aligned in the direction of spreading. Concomitantly, plaques positive for the focal adhesion protein paxillin were enhanced. HGF induced an increase in the translation of paxillin and, to a lesser extent, β1-integrin. This was independent of cell-matrix adhesion through β1-integrin. Subcellular fractionation revealed increased cosedimentation of paxillin with plasma membrane-containing fractions following HGF stimulation, without corresponding enhancements in paxillin coassociation with β1 integrin or actin. Tyrosine phosphorylation of paxillin was reduced by HGF and was sensitive to the Src kinase inhibitor PP2. With these taken together, we propose that HGF upregulates a free cytosolic pool of paxillin that is unaffiliated with either the cytoskeleton or focal cell-matrix contacts. Thus early spreading responses to HGF may partly relate to increased paxillin availability for incorporation into, and turnover within, dynamic cytoskeletal/membrane complexes whose rapid and transient adhesion to the matrix drives migration.


2005 ◽  
Vol 288 (1) ◽  
pp. F8-F15 ◽  
Author(s):  
Purba Biswas ◽  
Abinash Roy ◽  
Rujun Gong ◽  
Angelito Yango ◽  
Evelyn Tolbert ◽  
...  

Hepatocyte growth factor (HGF) is a multifunctional cytokine that plays a crucial role in renal development, injury, and repair. HGF also serves a protective role in chronic renal disease by preventing tissue fibrosis. Endothelin-1 (ET-1), produced primarily by endothelial cells, is a potent vasoconstrictor that also acts as a proinflammatory peptide, promoting vascular injury and renal damage. In addition to mediating a variety of epithelial cell responses, HGF also induces hemodynamic changes that are poorly understood. The aim of the present study was to study the acute and chronic effects of HGF on ET-1 production in the kidney. We hypothesized that hemodynamic changes upon HGF treatment are likely mediated by immediate ET-1 release, whereas protection from renal fibrosis in rats chronically treated with HGF is likely due to suppression of ET-1 production. Acute HGF infusion into rats caused a decline in blood pressure that was enhanced by pretreatment with bosentan (an endothelin A and B receptor antagonist). HGF infusion also resulted in a decline in glomerular filtration rate (GFR) that could be entirely prevented by bosentan, suggesting that HGF acutely increases production and/or release of ET-1, which then mediates the observed decline in GFR. In cultured glomerular endothelial cells, HGF induced ET-1 production in a dose-dependent manner. Moreover, although there was an initial increase in ET-1 production upon HGF treatment, longer administration suppressed ET-1 production. This finding was consistent with the observation in vivo of a decrease in ET-1 production in renal parenchyma of rats chronically treated with HGF. Our data suggest both a hemodynamic and biological role for HGF-mediated ET-1 regulation.


2003 ◽  
Vol 74 (5) ◽  
pp. 760-768 ◽  
Author(s):  
E. Cacci ◽  
M. Salani ◽  
S. Anastasi ◽  
I. Perroteau ◽  
G. Poiana ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4238
Author(s):  
Masahiro Mizuno ◽  
Behnoush Khaledian ◽  
Masao Maeda ◽  
Takanori Hayashi ◽  
Seiya Mizuno ◽  
...  

Adipose tissue is a component of the tumor microenvironment and is involved in tumor progression. We have previously shown that adipokine adipsin (CFD) functions as an enhancer of tumor proliferation and cancer stem cell (CSC) properties in breast cancers. We established the Cfd-knockout (KO) mice and the mammary adipose tissue-derived stem cells (mADSCs) from them. Cfd-KO in mADSCs significantly reduced their ability to enhance tumorsphere formation of breast cancer patient-derived xenograft (PDX) cells, which was restored by the addition of Cfd in the culture medium. Hepatocyte growth factor (HGF) was expressed and secreted from mADSCs in a Cfd-dependent manner. HGF rescued the reduced ability of Cfd-KO mADSCs to promote tumorsphere formation in vitro and tumor formation in vivo by breast cancer PDX cells. These results suggest that HGF is a downstream effector of Cfd in mADSCs that enhances the CSC properties in breast cancers.


2003 ◽  
Vol 13 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Y.-H. Park ◽  
H.-S. Ryu ◽  
D.-S. Choi ◽  
K.-H. Chang ◽  
D.-W. Park ◽  
...  

Matrix metalloproteinase (MMP)-2 and -9 are secreted and translocated from endometrial stromal cells to HEC-1 A cells in a steroid-dependent manner. We investigated the paracrine effect of hepatocyte growth factor (HGF) on MMPs and metalloproteinase tissue inhibitor (TIMP) expression in stromal and endometrial cancer cells, and correlated with cancer cell invasiveness in three-dimensional (3D) coculture. The 3D coculture of endometrial stromal and cancer cell lines (HEC-1 A, HEC-IB, or KLE) were maintained in the presence or absence of HGF. The expression of MMP-2 and -9, MT1-MMP, TIMP-1 and -2 were examined by RT-PCR and zymography. Under the same conditions, invasion of the cancer cells was quantified by Boyden's chamber assay. HGF strongly induced MMP-9 mRNA expression in stromal cells, but had little effect on MMP-2 mRNA. MT1-MMP mRNA was detected only in KLE and stromal cells, which was also increased by HGF. TIMP-1 and -2 mRNAs was ubiquitous with no dependence on HGF. Zymographic analysis of MMPs showed that activation of MMP-2 and -9 was enhanced by HGF. A significant increase in invasion of all three cancer cells with HGF was observed. The effect of HGF on the invasiveness of 3D cocultured endometrial cancer cells and stromal cells appears to be due to induction of MMP-9 mRNA expression in stromal cells and /or increased activation of MMP-2 and MMP-9 by proteolytic digestion.


1991 ◽  
Vol 100 (1) ◽  
pp. 173-177 ◽  
Author(s):  
R.A. Furlong ◽  
T. Takehara ◽  
W.G. Taylor ◽  
T. Nakamura ◽  
J.S. Rubin

Scatter factor, a stimulant of epithelial cell motility, and Hepatocyte Growth Factor (HGF) were compared by cross-biological studies using naturally occurring and recombinant proteins in four bioassays. Both scatter factor and HGF produced similar effects in cell motility and DNA synthesis assays. Antibodies to scatter factor or HGF neutralized the biological activities of each cytokine, and in immunoblotting reacted with species of the same Mr. These results, together with the available sequence data, suggest that scatter factor and HGF are the same protein.


1999 ◽  
Vol 112 (12) ◽  
pp. 1999-2009 ◽  
Author(s):  
J.A. Deakin ◽  
M. Lyon

Hepatocyte growth factor interacts with both heparan and dermatan sulphates, in addition to its specific signalling receptor, Met. However, the extent of glycosaminoglycan involvement in its biological activity remains uncertain. We have investigated the effects of exogenous glycosaminoglycan addition upon hepatocyte growth factor-stimulated motility of Madin-Darby canine kidney cells. Exogenous heparan/dermatan sulphate chains behave similarly as either potentiators or inhibitors of cell motility (depending upon the assay). Specific heparan sulphate oligosaccharides, of octasaccharide or larger, elicit similar effects, though with reduced potency. Additionally we have investigated the motility of cells made completely deficient in functional proteoglycans by metabolic inhibition of glycosaminoglycan sulphation, using chlorate. Such cells are completely unresponsive to hepatocyte growth factor, both in terms of downstream phosphorylation of mitogen-activated protein kinase and actual cell motility, though they do remain responsive to phorbol ester. Interestingly, although cell responsiveness to hepatocyte growth factor is not restored by exogenous heparan/dermatan sulphate chains, it is by an immobilised heparan sulphate proteoglycan substratum. These findings suggest that hepatocyte growth factor activity is not only critically dependent upon the presence of glycosaminoglycan, but specifically requires an intact proteoglycan structure located in close apposition to cell surface Met.


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