The Rapamycin-Sensitive Complex of Mammalian Target of Rapamycin Is Essential to Maintain Male Fertility

Am J Pathol. 2016 Feb;186(2):324-36. doi: 10.1016/j.ajpath.2015.10.012. Epub 2015 Dec 10.


The mammalian target of rapamycin complex 1 (mTORC1) inhibitor rapamycin and its analogs are being increasingly used in solid-organ transplantation. A commonly reported side effect is male subfertility to infertility, yet the precise mechanisms of mTOR interference with male fertility remain obscure. With the use of a conditional mouse genetic approach we demonstrate that deficiency of mTORC1 in the epithelial derivatives of the Wolffian duct is sufficient to cause male infertility. Analysis of spermatozoa from Raptor fl/fl*KspCre mice revealed an overall decreased motility pattern. Both epididymis and seminal vesicles displayed extensive organ regression with increasing age. Histologic and ultrastructural analyses demonstrated increased amounts of destroyed and absorbed spermatozoa in different segments of the epididymis. Mechanistically, genetic and pharmacologic mTORC1 inhibition was associated with an impaired cellular metabolism and a disturbed protein secretion of epididymal epithelial cells. Collectively, our data highlight the role of mTORC1 to preserve the function of the epididymis, ductus deferens, and the seminal vesicles. We thus reveal unexpected new insights into the frequently observed mTORC1 inhibitor side effect of male infertility in transplant recipients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation / drug effects*
  • Fertility / drug effects*
  • Male
  • Mammals
  • Mechanistic Target of Rapamycin Complex 1
  • Mice, Transgenic
  • Multiprotein Complexes / drug effects*
  • Phosphorylation
  • Seminal Vesicles / drug effects*
  • Seminal Vesicles / metabolism
  • Signal Transduction / drug effects*
  • Sirolimus / pharmacology*
  • TOR Serine-Threonine Kinases / drug effects*
  • Transcription Factors / metabolism


  • Multiprotein Complexes
  • Transcription Factors
  • Mechanistic Target of Rapamycin Complex 1
  • TOR Serine-Threonine Kinases
  • Sirolimus