[The effects of Hedgehog-Gli 1 signaling pathway on proliferation and apoptosis of hepatic stellate cells].
OBJECTIVE
To investigate the effect of Hedgehog-Gli1 signaling pathway on proliferation, apoptosis and activation of hepatic stellate cells (HSCs) in vitro.


METHODS
The expression of Shh, Smo, Ptc and Gli-1 in HSC-T6 cells was analyzed by RT-PCR. HSC-T6 cells were incubated with various concentration of cyclopamine (0, 50, 100, 150, 200, 250 mumol/L) for 24 hours, cell viability was checked by MTT colorimetric assay, cell cycle was analyzed by flow cytometry, apoptosis was assayed by agarose electrophoresis of DNA and PI-Annexin V fluorescent staining, and the mRNA levels of Gli-1, TGF beta 1, PDGF and Bcl-2 were quantified by real-time RT-PCR.


RESULTS
RT-PCR indicated that the components of the Hedgehog-Gli1 signaling pathway were expressed in HSC-T6 cells. MTT assay indicated that cyclopamine inhibited cell viability in a concentration dependant manner (F = 636.81, P less than 0.01). Flow cytometry indicated that cells were piled up at G0/G1 phase in cyclopamine treated cells (65.08%+/-1.50%) as compared to control cells (55.41%+/-2.54%, t = -8.05, P less than 0.01). Cyclopamine treatment resulted in apoptosis as indicated by DNA fragmentation and PI-Annexin V staining. The mRNA levels of Gli-1, TGF beta 1, PDGF and Bcl-2 in cyclopamine treated cells were significantly lower than that in control cells (P less than 0.01).


CONCLUSIONS
Cyclopamine may inhibit the Hedgehog-Gli1 signaling, and hence repress proliferation and promote apoptosis in hepatic stellate cells.
Liu
Jun
J
Department of Gastroenterology, Tenth People's Hospital of Tongji University, Shanghai 200072, China.
Xu
Xuan-Fu
XF
Yang
Wen-Juan
WJ
D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D014704:Veratrum Alkaloids / Q000494:pharmacology; D000071676:Zinc Finger Protein GLI1
C400551:GLI1 protein, human; D053823:Hedgehog Proteins; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D014157:Transcription Factors; D053773:Transforming Growth Factor beta1; D014704:Veratrum Alkaloids; D000071676:Zinc Finger Protein GLI1; C000541:cyclopamine