17 β-Estradiol alleviates oxidative damage in osteoblasts by regulating miR-320/RUNX2 signaling pathway

17β-estradiol inhibits lipopolysaccharide-induced inflammation and pyroptosis of Leydig cells of the domestic yak (Bos grunniens) via the SIRT1/Nox4/ROS pathway

Estradiol (E2) secreted by Leydig cells (LCs) can accumulate in the testes due to constriction of the reproductive lumen. Estrogen is not only important for reproduction, but also protects against inflammation. In this study, the role of pyroptosis in testicular inflammation and the effects of E2 against inflammation and pyroptosis of yak interstitial cells were investigated. Inflamed testes exhibited structural damage and pyroptosis with decreased E2, testosterone, and estrogen receptor β (ERβ) levels in testicular fluid. E2 alone inhibited testosterone secretion and increased ERβ expression in mature LCs. In LCs, lipopolysaccharide (LPS) causes inflammation by activation of TNF-α and IL-6, and pyroptosis via activation of the classical and non-classical pyroptosis pathways. LPS inhibits sex hormone secretion and ERβ expression in LCs. E2 inhibited the LPS-induced decrease of ER expression in LCs and also inhibited LPS-induced interstitial cell inflammation and pyroptosis, which was partially blocked by Selisistat (EX-527, SIRT1 inhibitor) or Fulvestrant (ICI 182,780, E2 non-genomic receptor inhibitors). In conclusion, E2 relieved LPS-induced inflammation and pyroptosis of yak LCs via the SIRT1/Nox4/ROS pathway. This finding provides new insights into the role of estrogen in male reproductive health and offers a potential therapeutic strategy to improve testicular immune and reproductive function by modulating hormonal homeostasis.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Chrysophanol Ameliorates Hemin-Induced Oxidative Stress and Endoplasmic Reticulum Stress by Regulating MicroRNA-320-5p/Wnt3a Pathway in HT22 Cells

Oxidative stress, endoplasmic reticulum (ER) stress, and neuronal cell apoptosis have been considered as the main pathogenesis factors of brain injury after intracerebral hemorrhage (ICH). Chrysophanol (CHR) has been proved to have neuroprotective effects, but the role and underlying mechanisms of CHR in ICH remain unclear. HT22 cells were dealt with hemin to mimic an in vitro ICH model and then subjected to treatment with or without CHR. The cell viability, apoptosis, ER stress, and oxidative stress were evaluated by conducting the cell counting kit-8 (CCK-8), TdT-mediated dUTP nick end labeling (TUNEL) staining assays, western blot, and corresponding kit, respectively. Further, microRNA-sequencing, bioinformatic analysis, dual-luciferase reporter method, and rescue experiments were conducted to explore the molecular mechanisms of CHR alleviating hemin-induced ER in HT22 cell. Our data revealed that CHR increased cells viability, antiapoptosis, anti-ER stress, and antioxidative stress under conditions of hemin-induced HT22 cell injury. Mechanically, it was observed that Wnt3a was competitively sponged by miR-320-5p, and CHR activated β-catenin pathway by regulating miR-320-5p/Wnt3a molecular axis. Finally, results from the rescue experiment suggested that CHR inhibited hemin-induced cells apoptosis, ER stress, and oxidative stress through regulating the miR-320-5p/Wnt3a axis in HT22 cells. In conclusion, CHR prevented hemin-induced apoptosis, ER stress, and oxidative stress via inhibiting the miR-320-5p/Wnt3a/β-catenin pathway in HT22 cells. Our results certified that CHR could be served as a promising treatment for brain damage following ICH.