This study aimed to assess the effects of simulated microgravity (SMG) on bovine muscle satellite cells (bSCs). The results demonstrated that bSCs maintained a fibroblast-like morphology throughout SMG exposure from day 3 to day 7. However, cells in the SMG group exhibited reduced proliferation compared to the control group, as indicated by lower cell density at both time points. In contrast, cell viability was higher in the SMG group than in the control group. Cell cycle analysis revealed a higher proportion of SMG-treated bSCs in the G0/G1 phase and a lower proportion in the S phase at day 3, suggesting cell cycle arrest at an early stage. Interestingly, by day 7, the percentage of cells in the S phase increased in the SMG group and exceeded that of the control group, indicating a partial recovery of proliferative activity. Western blot analysis showed decreased expression of key cell cycle-related proteins, including cyclin A1/A2, cyclin D1, and CDK2, in SMG-treated cells compared to controls at the early stage. Notably, cyclin D1 and CDK2 expression levels were upregulated at the later stage under SMG conditions. Additionally, nuclear morphology in SMG-treated bSCs displayed enlargement and irregularity. Overall, these findings suggest that SMG initially suppresses bSC proliferation by inducing cell cycle arrest, but cells can partially retrieve their proliferative capacity at later stages, potentially through upregulation of cell cycle regulatory proteins.
To explore the ameliorating effect of treadmill exercise on depression-like behavior in rats with chronic unpredictable stress (CUS). Thirty-six Sprague-Dawley rats were divided into three groups (n=12 per group): a control group, a CUS group and a CUS+exercise (CUS+EX) group. The CUS and CUS+EX groups received a 4-week CUS treatment, and the CUS+EX group began a 4-week moderate-intensity treadmill exercise at the second week of CUS treatment. Following the CUS treatment and treadmill exercise, the depressive-like behavior of rats was assessed using the open field test (OFT) and tail suspension test (TST). Plasma melatonin levels were measured using an enzyme-linked immunosorbent assay, and the superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in the prefrontal cortex (PFC) were detected using commercial kits. Compared with the control group, the CUS group showed shortened latency to first immobility and prolonged total immobility time in the TST, and decreased time spent in the center and reduced crossing and vertical activities in the OFT. Additionally, the SOD activity and the protein expressions of sirtuin 1 (SIRT1) and nuclear factor E2 associated factor 2 (Nrf2) in the PFC decreased, whereas the MDA level increased in the CUS group. Four weeks of concurrent treadmill exercise attenuated the effects of CUS: compared with the CUS group, the CUS+EX group exhibited reduced depressive-like behaviors, prevention of the CUS-induced decline in PFC SOD activity and SIRT1/Nrf2 protein expression and attenuation of the CUS-induced increase in PFC MDA levels. Treadmill exercise concurrently increased plasma melatonin levels and activated the SIRT1/Nrf2 antioxidant pathway in the PFC, which may contribute to the observed improvement in depressive-like behavior.
Excessive osteoclast activity drives bone-resorptive disorders, and oxidative stress is a key regulator of osteoclast differentiation. Hydrogen sulfide (H?S), an endogenous antioxidant, may modulate this process, but its mechanisms remain unclear. In this study, RANKL (50 ng/mL) was used to induce osteoclastogenesis in RAW264.7 cells, with or without the H?S donor sodium hydrosulfide (NaHS; 50-200 ?M). Osteoclast formation was evaluated by TRAP staining and NFATc1/Cathepsin K expression, while oxidative stress, lipid peroxidation, mitochondrial function, and ferroptosis-related parameters were assessed. Mechanistic studies revealed that NaHS promoted Nrf2 nuclear translocation and upregulated GPX4, HO-1, and NQO1, whereas inhibition of Nrf2 or GPX4 partially reversed these effects. NaHS significantly suppressed osteoclast differentiation, alleviated oxidative stress, and restored mitochondrial function. These findings demonstrate that H?S inhibits RANKL-induced osteoclastogenesis via the Nrf2/GPX4 pathway and suggest this redox axis as a potential therapeutic target for bone-resorptive diseases.
Sepsis is a complicated disorder caused by infection, which may trigger various symptoms. Lipopolysaccharides (LPS) are among the primary pathogens which can stimulate host's immunoreaction. In the late stage of sepsis, the patients' immune system is significantly suppressed, thus the mortality increases. Notably, autophagy is pivotal during sepsis, in which autophagosome-lysosome fusion mediated by syntaxin 17 (STX17) is a key step. Previous studies have shown that histone deacetylase 2 (HDAC2) deacetylated STX17 to promote autophagosome-lysosome fusion. Trichostatin A (TSA) as a HDAC inhibitor (HDACi) has the capability of inhibiting histone deacetylase activity, while such an effect can be reversed by ITSA-1. This time LPS was used to stimulate human monocyte-macrophages (THP-1 cells) to establish the inflammatory cell model. TSA and ITSA-1 were administrated. The cell proliferation was examined by WST-1. Cytokines such as TNF-? and IL-6, as well as HDAC2 activity and deacetylated STX17 (DA-STX17) expression were detected by ELISA. Also, autophagy-related proteins such as P62 and microtubule-associated protein light chain 3 (LC3) were detected by Western Blotting (WB), and autophagosome-lysosome fusion was observed by fluorescence assay. Cell apoptosis was measured by flow cytometry. Besides, network pharmacology analysis was conducted. The data showed that TSA inhibited HDAC2 activity, and remarkably downregulated DA-STX17 expression, accompanied by the lower expression of P62 and LC3 ?/I. Decreased DA-STX17 promoted autophagosome-lysosome fusion, and inhibited TNF-? secretion. Furthermore, network pharmacology analysis revealed an inner relationship concerning HDAC2 between TSA and sepsis. Therefore, TSA can be considered a potential drug to cure sepsis-related diseases.
Despite the widespread use of silver nanoparticles (AgNPs) in consumer, industrial, and biomedical products, their potential effects on female reproductive health, particularly during critical developmental periods, remain insufficiently understood. The present study was therefore designed to investigate in vivo the dose-dependent effects of AgNP exposure on ovarian function and reproductive health in pubertal female rats. Pubertal Wistar albino female rats were divided into control and two AgNP groups (0.05 and 0.50 mg/kg/day). After one month of therapy, the females in the different groups were euthanized, and ovarian samples were collected. The results indicated that administration of AgNPs significantly increases the number of primordial follicles and significantly increases the number of growing follicles. Western blot analysis revealed that aromatase (Cyp19) and proliferating cell nuclear antigen (PCNA) were upregulated in both treatment groups. Similarly, the number of mRNA transcripts associated with folliculogenesis and steroidogenesis increased significantly in the high-dose treatment group. In addition, the level of growth differentiation factor 9 (GDF9) mRNA increased significantly in a dose-dependent manner. However, the levels of anti-Müllerian hormone (Amh) mRNA were considerably higher in the low-dose group and lower in the high-dose group, demonstrating that the detailed regulation of this gene is affected by AgNP dose. Analysis of the phosphatidylinositol 3-kinase signaling pathway revealed that compared to a 0.05 mg/kg, a AgNP exposure at 0.5 mg/kg significantly enhanced the PI3K/AKT/mTOR pathway and impacted Ampk signaling in a distinct manner. These findings suggest that AgNPs increase follicular development and deplete the follicular reserve, resulting in a phenomenon known as “burnout”.
