Perifollicular stromal cells sustain folliculogenesis via MDK–NCL signaling in mice and humans

Integrated Single-cell Proteomic and Transcriptomic Landscape of Mouse Folliculogenesis.

Folliculogenesis is a complex process essential to female fertility, characterized by multifaceted communication between oocytes and granulosa cells (GCs). While transcriptional regulation during folliculogenesis has been extensively studied, the proteomic landscape remains largely unexplored. Here, we profiled both the proteomic and transcriptomic landscapes of single oocytes and their surrounding mini-bulk GCs across four consecutive stages, from secondary to preovulatory follicles. Integrated dual-omics analysis provided a high-resolution characterization of cell type-specific transcriptional and proteomic changes. Proteomic profiling revealed coordinated metabolic programs, in which oocytes shift toward lipid storage while GCs enhance energy production and steroidogenic metabolism to support oocyte maturation. These metabolic changes in oocytes were accompanied by dynamic remodeling of mitochondrial organization. In addition, we identified novel transcription factors involved in regulating folliculogenesis, as well as a SATB1-centered regulatory network that may reflect preparatory chromatin remodeling preceding zygotic genome activation. Furthermore, GDF9-BMPR2 signaling progressively increased from the secondary stage to the preovulatory stage, indicating strengthened intercellular communication between oocytes and GCs. Together, these findings provide mechanistic insights into oocyte development and follicle growth, with potential implications for novel fertility treatments and diagnostic strategies.

A transcriptomic map of ligand-receptor interactions within bovine antral follicles predicts intrafollicular factors for improving oocyte quality

Reconstructing a map of intrafollicular interactions provides novel insights and important clues for understanding cellular and molecular mechanisms that fine-tune antral folliculogenesis and offers a roadmap for predicting candidate factors that can be used for optimizing mammalian in vitro embryo production systems.

Theca cells: active orchestrators of ovarian aging.

Ovarian aging is characterized by the progressive depletion of the follicular reserve and deterioration of reproductive endocrine function, yet its cellular basis has been disproportionately attributed to oocyte and granulosa cell decline. Theca cells - the principal androgen-producing cell type of the ovarian follicle - have remained critically underappreciated in this context. Operating through the classical two-cell, two-gonadotropin model, theca cells supply androgen precursors that granulosa cells aromatize into estradiol, and their dysfunction therefore impairs estrogen biosynthesis irrespective of granulosa cell competence. During ovarian aging, theca cells undergo quantitative decline, transcriptional reprogramming, and progressive steroidogenic impairment. Single-cell transcriptomic analyses reveal age-dependent upregulation of senescence pathways - including CDKN1A, NF-κB, and SASP-associated factors - alongside downregulation of FOXP1, a transcription factor that normally suppresses cellular senescence through direct repression of CDKN1A. Senescent theca-interstitial cells elaborate pro-inflammatory mediators, most notably CCL5, TNF-α, IL-1β, and IL-6, which suppress steroidogenic gene expression, induce granulosa cell apoptosis, and promote ovarian fibrosis, collectively accelerating follicular atresia. At the molecular level, mitochondrial dysfunction driven by aberrant GSK3β activation impairs oxidative phosphorylation and steroidogenic capacity, while dysregulation of the PTEN/PI3K/Akt/FOXO1 axis uncouples theca cells from LH-dependent gonadotropin signaling. Theca cell dysfunction further underlies distinct clinical entities, including premature ovarian insufficiency, diminished ovarian reserve, and polycystic ovary syndrome. Emerging therapeutic strategies - encompassing mesenchymal stem cell-derived exosomes, senolytics, mitochondria-targeted interventions, and Wnt/β-catenin pathway modulation - have demonstrated efficacy in restoring theca cell function in preclinical models. This review repositions theca cells as active, bidirectionally regulated participants in ovarian aging-integral to, rather than upstream of, the oocyte-granulosa-theca unit-and proposes theca-specific biomarkers and targeted interventions as priorities for future translational research.

Single-cell atlas of the developing mouse oviduct reveals smooth muscle heterogeneity and identifies Vps34 as a critical regulator of female fertility

The oviduct smooth muscle layer is traditionally regarded as a contractile unit. Limited understanding exists regarding the molecular heterogeneity and intercellular communication during development timeline, which is critical for female reproductive function. To address this, we performed single-cell RNA sequencing (scRNA-seq) to profile the cellular composition of mice oviducts at four developmental stages: neonatal (7 days), pre-pubertal (3 weeks), young adult (8 weeks) and middle-aged (9 months). We aim to provide a framework for further investigation of oviduct biology and associated reproductive disorders. We delineate three distinct (SMC) subtypes, with their relative proportions shifting dynamically across the developmental timeline. SMC1 represented a transient progenitor population exclusive to neonatal oviducts. SMC2 displayed a mature contractile phenotype, while SMC3 uniquely expressed hormone-responsive genes (Esr1, Pgr) and showed enrichment of autophagy-related pathways. Functional studies demonstrated that SMC-specific deletion of Vps34 disrupts oviduct coiling and muscular integrity, leading to vacuolar degeneration and a significant reduction in litter size in mice. Additionally, we map five ciliated and six secretory epithelial subtypes and suggest that FN1 signaling may serve as a potential mediator of crosstalk between epithelial and SMCs during development, with the FN1-SDC4 axis emerging as the dominant interaction in mature oviducts. Thus, while the contractile and hormone-responsive functions of the oviductal muscle layer have long been recognized, our work provides its underlying cellular complexity during development. Our study constructs a developmental atlas of murine oviduct SMCs, revealing that the myosalpinx is composed of functionally distinct SMC subtypes with dynamic developmental trajectories. The identification of Vps34 as a critical guardian of myosalpinx integrity offers a new cellular framework for understanding human tubal pathologies. These findings highlight the importance of SMC subtype homeostasis and autophagy-mediated maintenance of myosalpinx structure, providing a basis for future mechanistic studies on oviduct function and dysfunction.

ZBP1-driven PANoptosis in granulosa cells mediates follicular arrest in PCOS: integrated transcriptomic evidence and baicalin's therapeutic potential.

Royal jelly ameliorates age-associated stem cell dysfunction with Chi3l1-mediated increase in CD206-positive macrophages

Abstract Nutritional interventions, including Royal Jelly (RJ), are potential modulators of tissue function during aging. However, the molecular mechanisms underlying food-derived modulation of tissue physiology remain poorly understood. Here we show that dietary RJ enhances stem/progenitor cell activity with age- and tissue-dependent Chi3l1 -mediated increases in CD206-positive macrophages. In aged mice, RJ administration increased proliferative activity of stem/progenitor cells in the skin and brain, accompanied by improved hair phenotypes and enhanced neurogenesis. Transcriptomic screening in human mesenchymal stem/stromal cells identified CHI3L1 as an RJ-responsive gene that is downregulated during cellular senescence. Hepatocyte-specific disruption of Chi3l1 using adeno-associated virus-mediated gene editing demonstrated that Chi3l1 is required for maintaining hepatic CD206-positive macrophage populations in vivo. Similar effects were observed with 10-hydroxy-2-decenoic acid, a major RJ component. These findings suggest that Chi3l1 is a physiologically regulated immune mediator, rather than a pathogenic factor in disease contexts, highlighting the importance of mechanistic studies of food-derived biological effects.