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Intense angiogenesis is critical for the development of the corpus luteum and is tightly regulated by numerous factors. However, the exact role transforming growth factor-b1 (TGFB1) plays during this follicular-luteal transition remains unclear. This study hypothesised that TGFB1, acting through TGFB receptor 1 (TGFBR1) and Smad2/3 signalling, would suppress angiogenesis during the follicular-luteal transition. Using a serum-free luteinising follicular angiogenesis culture system, TGFB1 (1 and 10 ngmL -1) markedly disrupted the formation of capillary-like structures, reducing the endothelial cell network area and the number of branch points (P,0.001 compared with control). Furthermore, TGFB1 activated canonical Smad signalling and inhibited endothelial nitric oxide synthase (NOS3) mRNA expression, but upregulated latent TGFB-binding protein and TGFBR1, serpin family E member 1 (SERPINE1) and serpin family B member 5 (SERPINB5) mRNA expression. SB431542, a TGFBR1 inhibitor, reversed the TGFB1-induced upregulation of SERPINE1 and SERPINB5. In addition, TGFB1 reduced progesterone synthesis by decreasing the expression of steroidogenic acute regulatory protein (STAR), cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and 3b-hydroxysteroid dehydrogenase (HSD3B1) expression. These results show that TGFB1 regulates NOS3, SERPINE1 and SERPINB5 expression via TGFBR1 and Smad2/3 signalling and this could be the mechanism by which TGFB1 suppresses endothelial networks. Thereby, TGFB1 may provide critical homeostatic control of angiogenesis during the follicular-luteal transition. The findings of this study reveal the molecular mechanisms underlying the actions of TGFB1 in early luteinisation, which may lead to novel therapeutic strategies to reverse luteal inadequacy. [ABSTRACT FROM AUTHOR]

Pheochromocytoma, as a neuroendocrine tumor with the highest genetic correlation in all types of tumors, has attracted extensive attention. Von Hipper Lindau (VHL) has the highest mutation frequency among the genes associated with pheochromocytoma. However, the effect of VHL on the proteome of pheochromocytoma remains to be explored. In this study, the VHL knockdown (VHL-KD) PC12 cell model was established by RNA interference (shRNA). We compared the proteomics of VHL-KD and VHL-WT PC12 cell lines. The results showed that the expression of 434 proteins (VHL shRNA/WT > 1.3) changed significantly in VHL-KD-PC12 cells. Among the 434 kinds of proteins, 83 were involved in cell proliferation, cell cycle and cell migration, and so on. More importantly, among these proteins, we found seven novel key genes, including Connective Tissue Growth Factor (CTGF), Syndecan Binding Protein (SDCBP), Cysteine Rich Protein 61 (CYR61/CCN1), Collagen Type III Alpha 1 Chain (COL3A1), Collagen Type I Alpha 1 Chain (COL1A1), Collagen Type V Alpha 2 Chain (COL5A2), and Serpin Family E Member 1 (SERPINE1), were overexpressed and simultaneously regulated cell proliferation and migration in VHL-KD PC12 cells. Furthermore, the abnormal accumulation of HIF2α caused by VHL-KD significantly increased the expression of these seven genes during hypoxia. Moreover, cell-counting, scratch, and transwell assays demonstrated that VHL-KD could promote cell proliferation and migration, and changed cell morphology. These findings indicated that inhibition of VHL expression could promote the development of pheochromocytoma by activating the expression of cell proliferation and migration associated genes. [ABSTRACT FROM AUTHOR]