Introduction
The ovary is a highly dynamic organ subjected to a variety of hypoxic and oxidative stress conditions, which involve members of the TGFβ superfamily. Vasorin/ATIA (Vasn) is a type I membrane protein, which can attenuate TGFβ signaling, and was recently identified as an oxidative stress regulator through binding of the mitochondrial antioxidant Thioredoxin 2 (Trx2).
Aim
Elucidate the role of Vasn in ovarian physiology under hypoxic/oxidative stress conditions and during aging
Materials & Methods
Super-ovulation was induced in 26-day-old female C57BL/6 mice using the PMSG/ hCG treatment protocol. Expression of Vasn mRNA was evaluated by qPCR and in-situ hybridization. Expression of RNA of potential binding partners of Vasn, such as Trx2 and TGFβ1, was assessed by qPCR. Cell fractionation followed by western blot analysis was employed for the study of Vasn protein expression in the mitochondria and cytosol of the granulosa cells.
Results
Our results demonstrated the expression of Vasn mRNA by ovarian granulosa cells during folliculogenesis and its upregulation by hCG. The corresponding protein is localized to the mitochondria and the cytosol of these ovarian cells. We also found that the mRNA of Trx2 and TGFβ1 are expressed by granulosa cells and are slightly up regulated in response to hCG. Both, Vasn and TRX2 are down regulated with age.
Conclusions
Our results support the hypothesis that Vasn is involved in ovarian physiology and aging. Our future experiments will use Vasn KO mice to identify the specific role of Vasn in protection against hypoxic and oxidative stress condition in the ovary.
