Objective We attempted to investigate the effect and role of Sept4 in mouse fibrotic livers infected with Schistosoma japonicum. We also attempted to observe the expression of miR-454 in HSCs and fibrotic livers and to study the effect and mechanism of miR-454 on activation of HSCs.Methods1. ICR mice(n=30) were adaptive fed for 1 week and randomly divided into 3 groups, named as PBS group(infected with Schistosoma japonicum and treated with PBS), Ad-GFP group(infected with Schistosoma japonicum and treated with Ad-GFP), Ad-Sept4 group(infected with Schistosoma japonicum and treated with Ad-Sept4). PBS group, Ad-GFP group and Ad-Sept4 group were given praziquantel(PZQ)(250mg/kg/24h) at 12 w post-infection to kill adult worms, and then treated with PBS, Ad-GFP and Ad-Sept4, respectivelly. All mice were killed at 15 w post-infection, and the changes in the fibrotic livers were detected via HE staining and Sirius red staining. The expression of Sept4, pro-collα1(I), α-SMA, cleaved-caspase-3, TGF-β1 and IL-6 was detected by Western Blot and qRT-PCR. And TUNEL analysis was used to observe the apoptosis phenomenon in the fibrotic livers treated with or without Ad-Sept4.2. ICR mice(n=16) were adaptive fed for 1 week and randomly divided into 2 groups, named as normal group and infection group(infected with Schistosoma japonicum). Mice were sacrificed at 8w post-infection. We detected the expression of miR-454 in fibrotic livers and in HSCs via qRT-PCR. We observed the effect of miR-454 on proliferation and cell cycle of HSCs by MTT analysis and flow cytometry, and we also observed the role of miR-454 on HSCs activation by Western Blot.Results1. Ad-Sept4 could ameliorate liver fibrosis, as detected by HE staining and Sirius red staining. The number of TUNEL-positive cells was increased in the Ad-Sept4 treated group, compared with the Ad-GFP group. The expression of Sept4 and cleaved-caspase-3 was increased, and the expression of α-SMA, pro-collα1(I), TGF-β1 and IL-6 was decreased, compared with that expressed in the Ad-GFP group.2. Expression of miR-454 was down-regulated in the activated HSCs and in the livers infected with Schistosoma japonicum. miR-454 did not affect the proliferation and cell cycle of activated HSCs. However, over-expression of miR-454 could inhibit the expression of α-SMA and Smad4.3. miR-454 mimics could inhibit the Smad4 luciferase activity in the activated HSCs.Conclusions1. Ad-Sept4 can inhibit the development of liver fibrosis induced by Schistosoma japonicum.2. Expression of mi R-454 is down-regulated in activated HSCs and in the fibrotic livers infected with Schistosoma japonicum.3. Over-expression of miR-454 can inhibit the activation of HSCs by inhibiting the activity of 3’ UTR domain of Smad4. |