Research Paper Volume 11, Issue 1 pp 185—208
Rapamycin-mediated mTOR inhibition impairs silencing of sex chromosomes and the pachytene piRNA pathway in the mouse testis
- 1 State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- 2 The People's Hospital of Gaochun, Nanjing, China
- 3 Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- 4 Heart and Vascular Center, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzho, Zhejiang 310003, China
- 5 The First Medical School of Nanjing Medical University, Nanjing, China
Received: September 26, 2018 Accepted: December 19, 2018 Published: January 13, 2019
https://doi.org/10.18632/aging.101740How to Cite
Abstract
Mechanistic target of rapamycin (mTOR) controls cell growth and metabolism in response to environmental and metabolic signals. Rapamycin robustly extends the lifespan in mammals and has clinical relevance in organ transplantation and cancer therapy but side effects include male infertility. Here, we report that chronic rapamycin treatment causes spermatogenic arrest in adult male mice due to defects in sex body formation and meiotic sex chromosome inactivation (MSCI). Many sex chromosome-linked genes were up-regulated in isolated pachytene spermatocytes from rapamycin-treated mice. RNA-Seq analysis also identified mRNAs encoding the core piRNA pathway components were decreased. Furthermore, rapamycin treatment was associated with a drastic reduction in pachytene piRNA populations. The inhibitory effects of rapamycin on spermatogenesis were partially reversible, with restoration of testis mass and sperm motility within 2 months of treatment cessation. Collectively, we have defined an essential role of mTOR in MSCI and identified a novel function as a regulator of small RNA homeostasis in male germ cells.