The activation of hepatic stellate cells (HSCs) is the key event of the pathogenesis of hepatic fibrosis. Platelet-derived growth factor (PDGF) is the most potent mitogen for HSCs, and PDGF receptor-beta subunit (PDGFR-beta) is required for the proliferation of HSCs induced by PDGF. In this study, a high gene-silencing-efficacy PDGFR-beta small interference RNA (siRNA) was synthesized that could suppress the PDGFR-beta expression and inhibit the activation and proliferation but could not induce the apoptosis of HSCs in vitro. To avoid the side effect of nonspecific interference of PDGFR-beta, we constructed an HSCs-specific short hairpin RNA (shRNA) expression plasmid in which PDGFR-beta shRNA was driven by a glial fibrillary acidic protein (GFAP) promoter. The double-staining immunofluorescence examination indicated that GFAP promoter could target the transgene expression into HSCs in carbon tetrachloride induced acute injured rat's liver and bile duct ligation (BDL)-induced chronic injured rat's liver. Furthermore, HSCs-specific PDGFR-beta shRNA could relieve liver injury and hepatic fibrosis in the rat's model induced by BDL. This study demonstrates that PDGFR-beta siRNA may be presented as an antifibrogenic agent. The application of HSCs-specific RNA interference induced by the GFAP promoter might supply a new powerful tool for cell-specific gene therapy of hepatic fibrogenesis.
The hypothesis that pioneer fibers, which develop relatively early in the differentiation of insect appendages, serve to organize the peripheral sensory nerves was tested by ablating apical regions of the cercal rudiments in embryos of Acheta domesticus. Multiple nerve bundles rather than the normal middorsal and midventral pair of nerves were formed within the cercus following ablation of the cercal tip before pioneer fiber differentiation, but the cercal nerve was normal when lesions were made after formation of the pioneer fiber tracts and associated glia. These results indicate a necessary morphogenetic role for the pioneer fibers.
The first two authors contributed equally to this work Bone morphogenetic protein 2 (BMP-2) is a member of the TGF-IJ superfamily of signaling molecules, and has been shown to function as a tumor suppressor involved in development and progression of many malignancies. BMP-2 has previously been reported to be closely correlated with lung cancer. But, the role and molecular mechanisms of BMP-2 in lung cancer have not yet been comprehensively explained. The present study aims to elucidate the role of BMP-2 in growth and invasion of human lung adenocarcinoma (LAC) in vitro and in vivo. Adenovirus vector-mediated BMP-2 small hairpin RNA (shBMP-2) was used to transfect into A549 LAC cells to determine the functional relevance of BMP-2 and tumor growth and invasion in vitro and in vivo, and further investigate the expression levels of BMP-2, vascular endothelial growth factor (VEGF), matrix metallopeptidase-9 (MMP-9), phosphatidylinositol 3-kinase p85a (PI3Kp85a) and phosphorylated AKT (P-AKT). As a result, LAC cell proliferation and invasion were significantly diminished by knockdown of BMP-2 indicated by MTT and Transwell assays, and cell apoptosis and cycle arrest were markedly induced indicated by flow cytometry. When BMP-2 expression was knocked down, the expression of PI3Kp85a, p-AKT, VEGF and MMP-9 was also down-regulated in LAC cells. In addition, the tumor volumes in LAC subcutaneous nude mouse model treated with shBMP-2 were significantly smaller than those in control and ad-GFP groups. Taken together, our findings indicate that knockdown of BMP-2 inhibits growth and invasion of LAC cells possibly via blockade of the PI3KJ AKT signaling pathway, and BMP-2 may be a potential therapeutic target for lung cancer.Lung cancer was the most commonly diagnosed cancer as well as the leading cause of cancer death in males in 2008 globally. Among females, it was the fourth most commonly diagnosed cancer and the second leading cause of cancer death (1). The current best approach for treatment of cancer is complete surgical removal of the tumor with the adjacent lymph nodes. However, the efficacy of this therapeutic approach, as well as hormone-, radio-, and chemo-therapy, is very limited (2). Tumor is also a genetic disease developing from a multi-step process. Single or multiple gene mutations is related to growth control, invasion and metastasis form the molecular genetic basis of malignant transformation and tumor progression. Therefore, identification of key genes or targets related to tumorigenesis is
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