FSH inhibits mitophagy via the mTOR/TFEB axis to preserve mitochondrial function in goat Sertoli cells

Sertoli cells sustain spermatogenesis by providing metabolic and structural support to germ cells. However, how endocrine signals regulate mitochondrial quality control, particularly mitophagy, in Sertoli cells remains unclear. Here, we investigated the role of follicle-stimulating hormone (FSH) in modulating mitophagy and mitochondrial function in primary goat Sertoli cells. FSH treatment increased the expression of LC3-II, PINK1 and Parkin, indicating activation of mitophagy initiation. However, the accumulation of p62 and the reduced colocalization between mitochondria and lysosomes revealed that FSH inhibited mitophagic flux by impairing autophagic degradation. FSH suppressed the nuclear translocation of transcription factor EB (TFEB) through activation of the mTOR pathway, thereby reducing lysosomal biogenesis and autophagic degradation capacity. Pharmacological and genetic manipulation of TFEB confirmed that TFEB is required for maintaining mitophagy and lysosomal function in Sertoli cells. Inhibition of mitophagy preserved mitochondrial integrity. Moreover, FSH-mediated suppression of mitophagy enhanced Sertoli cell metabolic and secretory activities, including lactate production and the secretion of key regulatory factors. Conditioned medium from FSH-treated Sertoli cells significantly promoted spermatogonial stem cell (SSC) proliferation and differentiation, indicating that Sertoli cell mitophagy indirectly regulates SSC fate. Collectively, our findings reveal that FSH restrains mitophagic flux via the mTOR/TFEB axis, thereby preserving mitochondrial function and enhancing Sertoli cell support capacity for SSC development. These findings identify FSH as a key regulator of mitophagy that preserves mitochondrial function and enhances the supportive capacity of Sertoli cells for SSC development.