Protein Tyrosine Phosphatase 1B-Mediated Granulosa Cell Insulin Resistance Links Metabolic Stress to Aging-Relevant Ovarian Dysfunction and Is Reversed by Gengnianchun.

Abstract

Metabolic disorders, particularly insulin resistance, are increasingly recognized as accelerators of female reproductive decline. However, the molecular mechanisms by which peripheral metabolic stress translates into impaired ovarian reserve remain incompletely understood. Here, we propose that protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, serves as a molecular bridge linking systemic insulin resistance to aging-relevant ovarian dysfunction and can be pharmacologically targeted. By integrating transcriptomic profiling of granulosa cells from women with diminished ovarian reserve (DOR) with network-based pharmacology and IR-DOR-associated gene annotations, we identified PTP1B as a candidate mediator of a metabolic stress-associated ovarian dysfunction axis. In a high-fat diet (HFD)-induced mouse model of systemic insulin resistance and metabolic stress-associated ovarian dysfunction, treatment with the traditional multi-herbal formula Gengnianchun (GNC) improved systemic glucose homeostasis, restored estrous cyclicity, and preserved primordial and growing follicles. These effects were accompanied by reduced ovarian PTP1B expression, reactivation of IRS1-AKT2 signaling, and enhanced GLUT4-mediated glucose handling in granulosa cells. In human granulosa-like KGN cells, GNC selectively restored insulin signaling and cell migration under insulin-resistant conditions; these effects were phenocopied by PTP1B knockdown and attenuated by PTP1B overexpression or pharmacological inhibition of AKT2. Collectively, these findings identify ovarian PTP1B as a key mediator of metabolic stress-associated, aging-relevant ovarian dysfunction and highlight PTP1B-directed interventions, including GNC, as potential strategies to preserve ovarian function in metabolically vulnerable states.