FSH directly regulates chondrocyte dedifferentiation and cartilage development

EGF-driven EGFR/miR-27b-3p/FOXO1 promotes rat FSH synthesis and secretion

The adenopituitary secretes follicle-stimulating hormone (FSH), which plays a crucial role in regulating the growth, development, and reproductive functions of organisms. Investigating the process of FSH synthesis and secretion can offer valuable insights into potential areas of focus for reproductive research. Epidermal growth factor (EGF) is a significant paracrine/autocrine factor within the body, and studies have demonstrated its ability to stimulate FSH secretion in animals. However, the precise mechanisms that regulate this action are still poorly understood. In this research, in vivo and in vitro experiments showed that the activation of epidermal growth factor receptor (EGFR) by EGF induces the upregulation of miR-27b-3p and that miR-27b-3p targets and inhibits Foxo1 mRNA expression, resulting in increased FSH synthesis and secretion. In summary, this study elucidates the precise molecular mechanism through which EGF governs the synthesis and secretion of FSH via the EGFR/miR-27b-3p/FOXO1 pathway.

Uncovering the "riddle of femininity" in osteoarthritis: a systematic review and meta-analysis of menopausal animal models and mathematical modeling of estrogen treatment

OBJECTIVE

Post-menopausal women are disproportionately affected by osteoarthritis (OA). As such, the purpose of this study was to (1) summarize the state-of-the-science aimed at understanding the effects of menopause on OA in animal models and (2) investigate how dosage and timing of initiation of estrogen treatment affect cartilage degeneration.

DESIGN

A systematic review identified articles studying menopausal effects on cartilage in preclinical models. A meta-analysis was performed using overlapping cartilage outcomes in conjunction with a rigor and reproducibility analysis. Ordinary differential equation models were used to determine if a relationship exists between cartilage degeneration and the timing of initiation or dosage of estrogen treatment.

RESULTS

Thirty-eight manuscripts were eligible for inclusion. The most common menopause model used was ovariectomy (92%), and most animals were young at the time of menopause induction (86%). Most studies did not report inclusion criteria, animal monitoring, protocol registration, or data accessibility. Cartilage outcomes were worse in post-menopausal animals compared to age-matched, non-menopausal animals, as evidenced by cartilage histological scoring [0.75, 1.72], cartilage thickness [-4.96, -0.96], type II collagen [-4.87, -0.56], and c-terminal cross-linked telopeptide of type II collagen (CTX-II) [2.43, 5.79] (95% CI of Effect Size (+greater in menopause, -greater in non-menopause)). Moreover, modeling suggests that cartilage health may be improved with early initiation and higher doses of estrogen treatment.

CONCLUSIONS

To improve translatability, animal models that consider aging and natural menopause should be utilized, and more attention to rigor and reproducibility is needed. Timing of initiation and dosage may be important factors modulating therapeutic effects of estrogen on cartilage.

Integrative Proteomics and Phosphoproteomics Analysis of the Rat Adenohypophysis after GnRH Treatment

The regulation of mammalian reproductive activity is tightly dependent on the HPG axis crosstalk, in which several reproductive hormones play important roles. Among them, the physiological functions of gonadotropins are gradually being uncovered. However, the mechanisms by which GnRH regulates FSH synthesis and secretion still need to be more extensively and deeply explored. With the gradual completion of the human genome project, proteomes have become extremely important in the fields of human disease and biological process research. To explore the changes of protein and protein phosphorylation modifications in the adenohypophysis after GnRH stimulation, proteomics and phosphoproteomics analyses of rat adenohypophysis after GnRH treatment were performed by using TMT markers, HPLC classification, LC/MS, and bioinformatics analysis in this study. A total of 6762 proteins and 15,379 phosphorylation sites contained quantitative information. Twenty-eight upregulated proteins and fifty-three downregulated proteins were obtained in the rat adenohypophysis after GnRH treatment. The 323 upregulated phosphorylation sites and 677 downregulated phosphorylation sites found in the phosphoproteomics implied that a large number of phosphorylation modifications were regulated by GnRH and were involved in FSH synthesis and secretion. These data constitute a protein-protein phosphorylation map in the regulatory mechanism of "GnRH-FSH," which provides a basis for future studies on the complex molecular mechanisms of FSH synthesis and secretion. The results will be helpful for understanding the role of GnRH in the development and reproduction regulated by the pituitary proteome in mammals.

LINC00707 knockdown inhibits IL-1β-induced apoptosis and extracellular matrix degradation of osteoarthritis chondrocytes by the miR-330-5p/FSHR axis

BACKGROUND

Osteoarthritis (OA) is a severe disabling condition that causes major health problems. The roles of lncRNAs in regulating OA progression have been increasingly researched. Based on previously published microarray analysis, LINC00707 is upregulated in OA. This research was done to uncover the function of LINC00707 in IL-1β-induced chondrocyte injury and its possible mechanisms.

METHODS

LINC00707, miR-330-5p, and FSHR expression in OA cartilage tissues were assessed by RT-qPCR. Primary chondrocytes were isolated from OA tissues and treated with IL-1β to establish an in vitro OA model. Under the indicated treatment, chondrocyte apoptosis, senescence, ECM degradation, and inflammation were determined using flow cytometry, TUNEL, SA-β-Gal staining, and ELISA experiments, respectively. Interactions between gene were evaluated using Ago2 RIP and luciferase reporter assays.

RESULTS

LINC00707 and FSHR were elevated, and miR-330-5p was reduced in cartilage tissues of OA patients and in IL-1β-treated primary chondrocytes. Silencing LINC00707 hampered chondrocytes apoptosis, senescence, ECM degradation, and inflammation. LINC00707 acted as a ceRNA to regulate FSHR through controlling miR-330-5p availability. Additionally, both miR-330-5p depletion and FSHR overexpression diminished the effects of silencing LINC00707 in OA progression.

CONCLUSION

Silencing LINC00707 mitigates chondrocyte injury in osteoarthritis via sponging miR-330-5p and inhibiting FSHR.

FSH modulated cartilage ECM metabolism by targeting the PKA/CREB/SOX9 pathway

INTRODUCTION

Osteoarthritis (OA) is a common joint disease characterized by articular cartilage degeneration. The prevalence of OA is higher among women than men, and this prevalence is closely related to menopause. The classic view assumes that the underlying mechanism of postmenopausal OA is attributed to declining estrogen levels. Although follicle-stimulating hormone (FSH) levels become elevated in parallel, the effects of FSH on OA have been poorly explored. The present study aimed to study the effect of FSH on cartilage metabolism.

METHODS

Chondrocyte-like ATDC5 cells were treated with recombinant FSH protein. Then the cell viability was measured using cell counting kit-8 assay. Expressions of crucial factors involved in the extracellular matrix (ECM) metabolic and PKA-CREB-SOX9 pathway were analyzed by western blot, RT-qPCR, and immunofluorescence staining. Intracellular cAMP levels were assessed by ELISA assay. Experimental OA in mice was induced by destabilization of the medial meniscus (DMM) surgery. Adeno-associated virus expressing shRNA against FSHR (AAV-shFSHR) was intra-articular (IA) injected into the OA model animals to specifically knock down FHSR in cartilage. Histological staining and OARSI scores were used to assess the efficacy of AAV-shFSHR injections.

RESULTS

We found that FSH down-regulated the expression of ECM-related proteins in chondrocyte-like ATDC5 cells. The underlying mechanism is probably associated with regulating PKA/CREB/SOX9 pathway. Besides, blocking FSH signaling via shRNA-mediated downregulation of FSHR in joint tissues effectively delayed the development of posttraumatic OA in mice.

CONCLUSIONS

Our results collectively indicated that FSH plays an essential role in the pathogenesis of OA and acts as a crucial mediator.

Males and Females Have Distinct Molecular Events in the Articular Cartilage during Knee Osteoarthritis

Osteoarthritis (OA) is a major public health challenge that imposes a remarkable burden on the affected individuals and the healthcare system. Based on the clinical observation, males and females have different prevalence rates and severity levels of OA. Thus, sex-based differences may play essential roles in OA’s prognosis and treatment outcomes. To date, the comprehensive understanding of the relationship between sex and OA is still largely lacking. In the current study, we analyzed a published transcriptome dataset of knee articular cartilage (GSE114007) from 18 healthy (five females, 13 males) and 20 OA (11 females, nine males) donors to provide a slight insight into this important but complex issue. First, comparing female healthy cartilage samples with those of males revealed 36 differential expression genes (DEGs), indicating the fundamental sex-related differences at the molecular level. Meanwhile, 923 DEGs were distinguished between OA and healthy female cartilage, which can be enriched to 15 Reactome pathways. On the other hand, when comparing OA and healthy male cartilage, there are only 419 DEGs were identified, and only six pathways were enriched against the Reactome database. The different signaling response to OA in the male and female cartilage was further enforced by recognizing 50 genes with significantly different OA-responsive expression fold changes in males and females. Particularly, 14 Reactome pathways, such as “Extracellular matrix organization”, “Collagen biosynthesis and modifying enzymes”, “Dissolution of fibrin clot”, and “Platelet Aggregation (Plug formation)”, can be noted from these 50 sex-dependent OA-responsive genes. Overall, the current study explores the Sex as a Biological Variable (SABV) at the transcriptomic level in the knee articular cartilage in both healthy status and OA event, which could help predict the differential OA prognosis and treatment outcome of males and female patients.