Lentivirus-mediated RNA interference targeting STAT4 inhibits the proliferation of vascular smooth muscle cells.
BACKGROUND
STAT4 is a key transcription factor regulating Th1 development. However, its presence and role in vascular smooth muscle cells (VSMCs) has not been well studied. In the current study, we have utilized lentivirus-mediated shRNA for functional gene knockdown in human umbilical artery smooth muscle cells in order to access the potential role of STAT4 in VSMC growth.


METHODS
Cells were isolated from the umbilical arteries of newborns and used at passage 3-5. Recombinant lentivirus producing STAT4 siRNA was prepared. Protein and mRNA expression of STAT4 and relevant genes were examined by Western blot, ELISA, and quantitative RT-PCR analysis, and the effects of the lentivirus on cell growth and apoptosis were determined using MTT assay and flow cytometry, respectively.


RESULTS
Lentivirus-mediated RNAi effectively reduced endogenous STAT4 expression and downregulation of STAT4 in VSMCs and significantly reduced VSMC growth rate in vitro. We found that STAT4 knockdown led to impaired pSTAT4 protein expression. SOCS-3 as well as MCP-1 production were also markedly decreased, consistent with the suppression of STAT4 expression.


CONCLUSIONS
Results from our study suggest that STAT4 may play a role in VSMC proliferation, and thus is a novel therapeutic target for neointima formation following vascular injury, e.g., post-angioplasty restenosis.
Lv
Lei
L
Department of Vascular Surgery, Renji Hospital, Shanghai Jiaotong University, Shanghai, China.
Zhang
Jiwei
J
Huang
Xiaozhong
X
Zhao
Yiping
Y
Zhou
Zhaoxiong
Z
Zhang
Hao
H
D001483:Base Sequence; D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis; D003001:Cloning, Molecular; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D034622:RNA Interference; D050797:STAT4 Transcription Factor / Q000235:genetics*; D014161:Transduction, Genetic
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D017931:DNA Primers; D050797:STAT4 Transcription Factor