Overexpression of the steroidogenic acute regulatory protein increases the expression of ATP-binding cassette transporters in microvascular endothelial cells (bEnd.3).

OBJECTIVE: To determine the effect of steroidogenic acute regulatory protein (StAR) overexpression on the levels of adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) in an endothelial cell line (bEnd.3). METHODS: The StAR gene was induced in bEnd.3 cells with adenovirus infection. The infection efficiency was detected by fluorescence activated cell sorter (FACS) and fluorescence microscopy. The expressions of StAR gene and protein levels were detected by real-time polymerase chain reaction (PCR) and Western blot. The gene and protein levels of ABCA1 and ABCG1 were detected by real-time PCR and Western blot after StAR overexpression. RESULTS: The result shows that StAR was successfully overexpressed in bEnd.3 cells by adenovirus infection. The mRNA and protein expressions of ABCA1 and ABCG1 were greatly increased by StAR overexpression in bEnd.3 cells. CONCLUSION: Overexpression of StAR increases ABCA1 and ABCG1 expressions in endothelial cells.

Effects of RNA interference-induced tryptase down-regulation in P815 cells on IL-6 and TNF-alpha release of endothelial cells.

OBJECTIVE: To explore the effects of down-regulated tryptase expression in mast cells on the synthesis and release of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) of vascular endothelial cells. METHODS: Tryptase-siRNA (small-interfering RNA) vector was constructed to inhibit tryptase expression in P815 cells. The medium of P815 cells treated by the tryptase-siRNA (RNAi-P815 group) or pure vector (P815 group) was collected and used to culture bEnd.3 cells. The messenger RNAs (mRNAs) of IL-6 and TNF-alpha in bEnd.3 cells and their protein levels in the medium were measured by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: IL-6 and TNF-alpha mRNAs in bEnd.3 cells cultured in RNAi-P815-conditioned medium decreased significantly compared to those in P815-conditioned medium. Consistently, IL-6 and TNF-alpha protein levels in the medium of bEnd.3 of RNAi-P815 group were lower than those of P815 group. CONCLUSION: Reduced tryptase expression significantly inhibited the synthesis and release of IL-6 and TNF-alpha in vascular endothelial cells. RNA interference targeting tryptase expression may be a new anti-inflammatory strategy for vascular diseases.