My research interests are focused towards understanding how various factors like steroid hormones, intra-follicular proteins and gonadotropins regulate ovarian physiology, specifically follicular development in normal and patho-physiological conditions affecting female fertility. My present research encompasses 2 projects:
Androgen signaling in ovarian development and function: Androgens have long been referred to as the "male" hormone and almost universally were considered detrimental to normal folliculogenesis, and elevated androgens in women have been associated with poor health and reduced fertility. Interestingly, in recent years, our studies have helped in putting forth a new concept suggesting that sufficient androgen signaling through the androgen receptor (AR) is necessary for normal follicle development and function. We have developed an ovary-specific AR knockout mouse model to determine the role of granulosa cell-specific ARs in follicular development and female fertility. Another major effort of my research is to determine the intra-cellular mechanism of androgens and how it regulates ovarian physiology and female fertility in normal and patho-physiological conditions like pre-mature ovarian failure (POF) or diminished ovarian reserve (DOR). In recent years the use of androgen treatments in women with DOR or POF has become highly popular across the world. Thus, through collaboration with IVF clinicians we are now extending our observations in the mouse to a clinical setting.

My second research project involves in understanding ovarian effects of obesity and its contribution to female sub-fertility or infertility. I am specifically interested in identifying local intra-follicular regulatory molecules, their cognate signaling pathways and their respective actions affecting ovarian function under obese conditions. We have identified a novel intra-cellular mechanism of action for leptin in the ovary that accounts for most of leptin's known negative effects of obesity on ovarian function. Using transgenic mouse models and human samples our aim is to develop a potential biomarker for obesity-related fertility problems that has predictive value for in vitro fertilization (IVF) outcomes in obese patients.

• Sen A, Caiazza F. Oocyte Maturation: A story of arrest and release . Front Biosci (Schol Ed). 2013; 5:451-77.
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• Sen A, De Castro I, Defranco DB, Deng FM, Melamed J, Kapur P, Raj GV, Rossi R, Hammes SR. Paxillin mediates extranuclear and intranuclear signaling in prostate cancer proliferation. J Clin Invest. 2012 Jul 2; 122(7):2469-81.
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• Sen A, Prizant H, Hammes SR. Understanding extranuclear (nongenomic) androgen signaling: what a frog oocyte can tell us about human biology. Steroids. 2011 Aug; 76(9):822-8.
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• Sen A, O'Malley K, Wang Z, Raj GV, Defranco DB, Hammes SR. Paxillin regulates androgen- and epidermal growth factor-induced MAPK signaling and cell proliferation in prostate cancer cells. J Biol Chem. 2010 Sep 10; 285(37):28787-95.
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• Sen A, Hammes SR. Just when you thought it was safe to go into the membrane: the growing complexities of extra-nuclear progesterone signaling. Breast Cancer Res. 2010; 12(3):109.
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• Sen A, Hammes SR. Granulosa cell-specific androgen receptors are critical regulators of ovarian development and function. Mol Endocrinol. 2010 Jul; 24(7):1393-403.
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• Sen A, Lv L, Bello N, Ireland JJ, Smith GW. Cocaine- and amphetamine-regulated transcript accelerates termination of follicle-stimulating hormone-induced extracellularly regulated kinase 1/2 and Akt activation by regulating the expression and degradation of specific mitogen-activated protein kinase phosphatases in bovine granulosa cells. Mol Endocrinol. 2008 Dec; 22(12):2655-76.
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• Bettegowda A, Yao J, Sen A, Li Q, Lee KB, Kobayashi Y, Patel OV, Coussens PM, Ireland JJ, Smith GW. JY-1, an oocyte-specific gene, regulates granulosa cell function and early embryonic development in cattle. Proc Natl Acad Sci U S A. 2007 Nov 6; 104(45):17602-7.
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