Dr Sidis is an Instructor in Medicine at Harvard Medical School, and an Assistant in Biochemistry at Massachusetts General Hospital.

His research has focused on the role of paracrine and autocrine signals in the regulation of the female reproductive axis. Present investigations aim to understand the function and mechanism of action of activins and related factors in the development and maturation of the ovarian follicle and in the control of pituitary FSH biosynthesis.

Activins are multi-potent cytokines that belong to the TGF-b super-family of growth and differentiation factors. They have been implicted in a diverse range of biological functions including reproduction, embryonic development, hematopoietic and bone cell differentiation, wound repair and inflammation response.

We utilize advanced molecular and cellular biology techniques in combination with traditional biochemical and endocrinology approaches to study structural and functional determinants involved in the interaction between activin and its binding proteins follistatin and FSRP (follistatin related protein/FLRG). These interactions are crucial for achieving proper biological response in target tissue since they establish the overall bioavailability of activin at its cell surface receptors. Another set of studies focuses on the molecular mechanisms that mediate the antagonistic effects of activins and its closely related factors inhibins in the context of various reproductive cell models.

Selected Publications:

• Xia Y, Sidis Y, Mukherjee A, Samad TA, Brenner G, Woolf CJ, Lin HY, Schneyer A. Localization and action of Dragon (RGMb), a novel BMP co-receptor, throughout the reproductive axis. Endocrinology 2005: In Press.

• Sidis Y, Schneyer AL, Keutmann HT. Heparin and activin-binding determinants in follistatin and FSTL3. Endocrinology. 2005 Jan;146(1):130-6. Epub 2004 Oct 7.

• Samad TA, Rebbapragada A, Bell E, Zhang Y, Sidis Y, Jeong SJ, Campagna JA, Perusini S, Fabrizio DA, Schneyer AL, Lin HY, Brivanlou AH, Attisano L, Woolf CJ. DRAGON, a bone morphogenetic protein co-receptor. J Biol Chem. 2005 Apr 8;280(14):14122-9. Epub 2005 Jan 25

• Del Re E, Sidis Y, Fabrizio DA, Lin HY, Schneyer A. Reconstitution and analysis of soluble inhibin and activin recetor complexes in a cell-free system. J. Biol. Chem 2004; 279:53126-35.

• Keutmann HT, Schneyer AL, Sidis Y. The role of follistatin domains in follistatin biological action. Mol Endocrinol. 2004 Jan;18(1):228-40. Epub 2003 Oct 16.

• Schneyer A, Sidis Y, Xia Y, Saito S, del Re E, Lin HY, Keutmann H. Differential actions of follistatin and follistatin-like 3. Mol. Cell. Endo. 2004 Oct;225(1-2):25-28.

• Schneyer AL, Wang Q, Sidis Y, Sluss PM. Differential distribution of follistatin isoforms: Application of a new FS315-specific immunoassay. J. Clin Endocrinol Metab 2004; 89:5067-75.

• Xia Y, Sidis Y, Schneyer A. Overexpression of follistatin-like 3 in gonads causes defects in gonadal development and function in transgenic mice. Mol Endocrinol. 2004 Apr;18(4):979-94.

• Sidis Y, Tortoriello DV, Holmes WE, Pan Y, Keutmann HT, Schneyer AL. Follistatin-related protein and follistatin differentially neutralize endogenous vs. exogenous activin. Endocrinology. 2002 May;143(5):1613-24.

• Sidis Y, Schneyer AL, Sluss PM, Johnson LN, Keutmann HT. Follistatin: essential role for the N-terminal domain in activin binding and neutralization. J Biol Chem. 2001 May 25; 276(21):17718-26.