Leptin Signaling in Reproductive Physiology

Leptin, an adipocyte-derived hormone, serves as a critical link between energy homeostasis and reproductive function. Acting centrally, leptin modulates hypothalamic centres that regulate gonadotropin-releasing hormone secretion and thus influences the hypothalamic–pituitary–gonadal axis. Peripherally, leptin receptors are expressed in ovarian cells where leptin shapes steroidogenic pathways, follicle development and oocyte maturation. Through interactions with intracellular effectors such as JAK–STAT and MAPK cascades, leptin influences the expression of genes essential for steroidogenic acute regulatory protein and downstream synthesis of oestradiol and progesterone. By acting as a metabolic gatekeeper, leptin ensures that reproductive events proceed only under favourable energy conditions. Dysregulation of leptin signalling, whether through nutritional imbalance, obesity or receptor defects, disrupts follicular hierarchy, impairs steroidogenesis and alters oocyte competence. Understanding the pleiotropic actions of leptin across central and peripheral sites is essential for elucidating the mechanisms that integrate metabolic status with fertility, and for developing strategies to address infertility associated with metabolic disorders.

Research from Nature Portfolio

Recent studies have identified follicular fluid leptin concentration as a robust predictor of oocyte maturity in assisted reproduction. Quantitative analysis of follicular cytokines in patients with varying ovarian reserves revealed that optimal leptin levels correlate with the highest yields of mature oocytes. By establishing a threshold concentration for leptin within the follicular microenvironment, researchers have proposed its use as a biomarker to refine oocyte selection and improve clinical outcomes. This work highlights the utility of local leptin measurement in guiding in vitro fertilisation protocols and underscores the hormone’s direct involvement in folliculogenesis.

Leptin Signaling in Reproductive Physiology publication trend

The graph below shows the total number of articles in leptin signaling in reproductive physiology across all publications each year (not limited to Nature Index journals).

Technical terms

Leptin: A peptide hormone produced by adipose tissue that conveys information about energy stores to reproductive and metabolic centres.

Leptin receptor (LepR): A transmembrane protein whose activation by leptin initiates intracellular signalling cascades, notably JAK–STAT and MAPK pathways.

Granulosa cells: Somatic ovarian cells that surround the oocyte, synthesise steroid hormones and respond to gonadotropins and metabolic signals.

Folliculogenesis: The process of growth and maturation of ovarian follicles culminating in ovulation.

Steroidogenesis: The enzymatic pathway by which cholesterol is converted to steroid hormones such as oestradiol and progesterone.

References

1. The intrafollicular concentration of leptin as a potential biomarker to predict oocyte maturity in in-vitro fertilization. Scientific Reports (2022).
2. Leptin interferes with 3',5'-Cyclic Adenosine Monophosphate (cAMP) signaling to inhibit steroidogenesis in human granulosa cells. Reproductive Biology and Endocrinology (2009).
3. Maternal obesity and ovarian failure: is leptin the culprit?. Animal Reproduction (2022).