Effects of Rho GTPase expression and migration induced by transform growth factor?1 in hepatic stellate cells
- VernacularTitle:转化生长因子?_1对肝星状细胞迁移及细胞内Rho三磷酸鸟苷酶表达的影响
- Author:
Lei LI
;
Wei JIANG
;
Ji-Yao WANG
;
Changqing YANG
;
Yiqing WANG
;
- Publication Type:Journal Article
- Keywords:
Transforming growth factor?1;
Hepatic stellate cells;
Migration;
Cytoskeleton
- From:
Chinese Journal of Digestion
2001;0(08):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of Rho GTPase expression,actin cytoskeleton re- organization and cell migration in hepatic stellate cells after transform growth factor(TGF)?_1 stimulated. Methods Primary rat hepatic stellate cells were isolated and cultured.A Transwell Chamber system was used to observe the changes of serum starved HSCs haptotactic migration (direct stimulation) and chem- otactie migration(indirect stimulation) after different concentration of TGF?_1 treatment.Changes in ac- tin cytoskeletal organization were visualized by fluorescence staining using FITC labeled phalloidin and fluorescence images were recorded using confocal microscopy.The activation of GTP-loaded GTPases were evaluated by GST pull-down assays with GST-fusion proteins of GTPase hinging domains of differ- ent effectors for Rho GTPases.Results TGF?_1 treatment of hepatic stellate cells resulted in the en- hancement of migration in response to haptotactic and chemotactic stimuli,especially after 5ng/ml TGF?_1 stimulation(haptotactic migration cells :130.90?7.64 vs 102.93?1.01,P＜0.05;chemotactie migration cells:205.17?10.78 vs 102.93?1.01,P＜0.05).Serum-starved,untreated cells had a rounded-up morphology.Stimulation of hepatic stellate cells with 5 ng/ml TGF?_1 induced a rapid mor- phological change concomitant with a robust reorganization of actin cytoskeleton.Five minutes after TGF?_1 stimulation,the cells flattened out and the formation of lamellipodia occurred.Five minutes after TGF?_1 was added,stress fibers became visible,and after 15-30 minutes,the cells became well spread with fully developed stress fibers.TGF?_1 stimulation did not alter the amount of GTP-bound Racl.In contrast,Cdc42 and RhoA GTPase activity was significantly augmented after more than 5ng/ml TGF?_1 stimulation(GTP-Cdc42:0.273?0.024 vs 0.176?0.001,P＜0.05;GTP-RhoA:0.176?0.005 vs 0.096?0.004,P＜0.05).Conclusion The stimulation of TGF?_1 can induce the actin cytoskeleton re- organization,which appears to be mediated through the activity of the Rho GTPases signaling pathway. The ability of TGF?_1 to trigger activation of Cdc42 and RhoA GTPase along with actin cytoskeleton reor- ganization might well play a crucial role in hepatic stellate cells migration.
