dentification of testosterone-/androgen receptor-regulated genes in mouse Sertoli cells

Androgen and androgen receptor （AR） play important roles in male spermatogenesis and fertility, yet detailed androgen/AR signals in Sertoli cells remain unclear. To identify AR target genes in Sertoli cells, we analyzed the gene expression profiles of testis between mice lacking AR in Sertoli cells （S-AR-/y） and their littermate wild-type （WT） mice. Digital gene expression analysis identified 2276 genes downregulated and 2865 genes upregulated in the S-AR-/y mice testis compared to WT ones. To further nail down the difference within Sertoli cells, we first constructed Sertoli cell line TM4 with stably transfected AR （named as TM4/AR） and found androgens failed to transactivate AR in Sertoli TM4 and TM4/AR cells. Interestingly, additional transient transfection of AR-cDNA resulted in significant androgen responsiveness with TM4/AR cells showing 10 times more androgen sensitivity than TM4 cells. In the condition where maximal androgen response was demonstrated, we then analyzed gene expression and found the expression levels of 2313 genes were changed more than twofold by transient transfection of AR-cDNA in the presence of testosterone. Among these genes, 603 androgen-/ AR-regulated genes, including 164 upregulated and 439 downregulated, were found in both S-AR-/y mice testis and TM4/AR cells. Using informatics analysis, the gene ontology was applied to analyze these androgen-/AR-regulated genes to predict the potential roles of androgen/AR in the process of spermatogenesis. Together, using gene analysis in both S-AR-/y mice testis and TM4/AR cells may help us to better understand the androeen/AR signals in Sertoli cells and their influences in spermatogenesis.

Endogenous tissue factor pathway inhibitor in vascular smooth muscle cells inhibits arterial thrombosis

Tissue factor pathway inhibitor （TFPI） is the main inhibitor of tissue factor-mediated coagulation. TFPI is expressed by endothelial and smooth muscle cells in the vasculature. Endothefium-derived TFPI has been reported to play a regulatory role in arterial thrombosis. However, the role of endogenous TFPI in vascular smooth muscle cells （VSMCs） in thrombosis and vascular disease development has yet to be elucidated. In this TFPI^Flox mice crossbred with Sma-Cre mice were utilized to establish TFPI conditional knockout mice and to examine the effects of VSMC-directed TFPI deletion on development, hemostasis, and thrombosis. The mice with deleted TFPI in VSMCs （TFP^Sma） reproduced viable offspring. Plasma TFPI concentration was reduced 7.2% in the TFPIsma mice compared with TFPI^Flox littermate controls. Plasma TFPI concentration was also detected in the TFPI^Tle2 （mice deleted TFPI in endothefial ceils and cells of hematopoietic origin） mice. Plasma TFPI concentration of the TFPI^Tle2 mice was 80.4% lower （P 〈 0.001） than that of the TFPI^Flox mice. No difference in hemostatic measures （PT, APTT, and tail bleeding） was observed between TFPIsma and TFPI^Flox mice. However, TFP^Sma mice had increased ferric chloride-indueed arterial thrombosis compared with TFPI^Flox littermate controls. Taken together, these data indicated that endogenous TFPI from VSMCs inhibited ferric chloride-induced arterial thrombosis without causing hemostatic effects.