RFRP-3 suppresses ovarian granulosa cell function in Tan sheep via dual signaling pathways: PI3K/AKT/mTOR and MAPK/ERK1/2

  • Theriogenology. 2026 Aug:260:117909. doi: 10.1016/j.theriogenology.2026.117909.
Shihao Wei  1 ,  Tianshu Dai  2 ,  Wei Song  1 ,  Yun Ma  3 ,  Xingang Dan  4
Affiliations
  • 1. College of Animal Science and Technology, Ningxia University, Yinchuan, China; Ningxia Key Laboratory of Precision Breeding and Nutritional Regulation for Advantageous and Distinctive Livestock and Poultry, Yinchuan, China.
  • 2. College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
  • 3. College of Animal Science and Technology, Ningxia University, Yinchuan, China; Ningxia Key Laboratory of Precision Breeding and Nutritional Regulation for Advantageous and Distinctive Livestock and Poultry, Yinchuan, China. Electronic address: [email protected].
  • 4. College of Animal Science and Technology, Ningxia University, Yinchuan, China; Ningxia Key Laboratory of Precision Breeding and Nutritional Regulation for Advantageous and Distinctive Livestock and Poultry, Yinchuan, China. Electronic address: [email protected].
PMID: 41924772 DOI: 10.1016/j.theriogenology.2026.117909
Abstract

The inhibitory role of RFRP-3 in the hypothalamic-pituitary axis is established, but its direct intra-ovarian actions remain poorly defined. This study reveals, for the first time, the expression of RFRP-3 and its receptor GPR147 in ovarian granulosa cells of Tan sheep. We demonstrate that RFRP-3 acts locally to suppress steroidogenesis by downregulating key steroidogenic Enzymes (STAR, CYP19A1, HSD17B2). Furthermore, it inhibits proliferation and promotes Apoptosis by modulating cell-cycle regulators (PCNA, CCND1, CDK4, CDK1, CCNB) and apoptosis-related proteins (Bcl-2, Bax, p53). A pivotal and novel finding, revealed by transcriptome Sequencing and Western blot, is that RFRP-3 exerts these dual effects through the concurrent inhibition of two major signaling pathways: it impedes steroid hormone synthesis via the MAPK/ERK1/2 pathway and inhibits cell proliferation and promotes Apoptosis via the PI3K/Akt/mTOR pathway. This study provides the first evidence of a local RFRP-3 system in the Tan sheep ovary and delineates a unique dual-pathway mechanism that precisely controls granulosa cell function. These findings provide theoretical insights into novel mechanisms of reproductive regulation in Tan sheep and establish a foundation for developing targeted strategies to enhance their reproductive capacity.

Keywords
Apoptosis; Granulosa cells; Proliferation; RFRP-3; Signaling pathways; Steroid hormones.
Products