Research Newsletter - September 2010

Spotlight

This month we highlight a paper published in the journal Cell by HSCI Principal Faculty member Pier Paolo Pandolfi, MD, PhD, and colleagues.

Plzf regulates germline progenitor self-renewal by opposing mTORC1

Abstract:

Hyperactivity of mTORC1, a key mediator of cell growth, leads to stem cell depletion, although the underlying mechanisms are poorly defined. Using spermatogonial progenitor cells (SPCs) as a model system, we show that mTORC1 impairs stem cell maintenance by a negative feedback from mTORC1 to receptors required to transduce niche-derived signals. We find that SPCs lacking Plzf, a transcription factor essential for SPC maintenance, have enhanced mTORC1 activity. Aberrant mTORC1 activation in Plzf(-/-) SPCs inhibits their response to GDNF, a growth factor critical for SPC self-renewal, via negative feedback at the level of the GDNF receptor. Plzf opposes mTORC1 activity by inducing expression of the mTORC1 inhibitor Redd1. Thus, we identify the mTORC1-Plzf functional interaction as a critical rheostat for maintenance of the spermatogonial pool and propose a model whereby negative feedback from mTORC1 to the GDNF receptor balances SPC growth with self-renewal.

Hobbs RM, Seandel M, Falciatori I, Rafii S, Pandolfi PP . Plzf regulates germline progenitor self-renewal by opposing mTORC1. Cell. 2010 Aug 6;142(3):468-79. Read Paper.

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