Epigenetic regulations of cellular senescence in osteoporosis.

Osteoporosis (OP) is a prevalent age-related disease that is characterized by a decrease in bone mineral density (BMD) and systemic bone microarchitectural disorders. With age, senescent cells accumulate and exhibit the senescence-associated secretory phenotype (SASP) in bone tissue, leading to the imbalance of bone homeostasis, osteopenia, changes in trabecular bone structure, and increased bone fragility. Cellular senescence in the bone microenvironment involves osteoblasts, osteoclasts, and bone marrow mesenchymal stem cells (BMSCs), whose effects on bone homeostasis are regulated by epigenetics. Therefore, the epigenetic regulatory mechanisms of cellular senescence have received considerable attention as potential targets for preventing and treating osteoporosis. In this paper, we systematically review the mechanisms of aging-associated epigenetic regulation in osteoporosis, emphasizing the impact of epigenetics on cellular senescence, and summarize three current methods of targeting cellular senescence, which is helpful better to understand the pathogenic mechanisms of cellular senescence in osteoporosis and provides strategies for the development of epigenetic drugs for the treatment of osteoporosis.

Changes in the gut microbiota structure and function in rats with doxorubicin-induced heart failure.

Objectives: The rat model of heart failure (HF) induced by doxorubicin (DOX), a broad spectrum and highly effective chemotherapeutic anthracycline with high-affinity to myocardial tissue that causes severe dose-dependent irreversible cardiotoxicity has been widely recognized and applied in HF pathogenesis and drug therapy studies. The gut microbiota (GM) has attracted significant attention due to its potential role in HF, and research in this area may provide beneficial therapeutic strategies for HF. Considering the differences in the route, mode, and total cumulative dose of DOX administration used to establish HF models, the optimal scheme for studying the correlation between GM and HF pathogenesis remains to be determined. Therefore, focusing on establishing the optimal scheme, we evaluated the correlation between GM composition/function and DOX-induced cardiotoxicity (DIC). Methods: Three schemes were investigated: DOX (at total cumulative doses of 12, 15 or 18 mg/kg using a fixed or alternating dose via a tail vein or intraperitoneal injection) was administered to Sprague Dawley (SD) for six consecutive weeks. The M-mode echocardiograms performed cardiac function evaluation. Pathological changes in the intestine were observed by H&E staining and in the heart by Masson staining. The serum levels of N-terminal pre-B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) were measured by ELISA. The GM was analysed by 16S rRNA gene sequencing. Key findings: Strikingly, based on the severity of cardiac dysfunction, there were marked differences in the abundance and grouping of GM under different schemes. The HF model established by tail vein injection of DOX (18 mg/kg, alternating doses) was more stable; moreover, the degree of myocardial injury and microbial composition were more consistent with the clinical manifestations of HF. Conclusions: The model of HF established by tail vein injection of doxorubicin, administered at 4mg/kg body weight (2mL/kg) at weeks 1, 3 and 5, and at 2mg/kg body weight (1mL/kg) at weeks 2, 4 and 6, with a cumulative total dose of 18mg/kg, is a better protocol to study the correlation between HF and GM.

Effect of pharmacological treatment on outcomes of heart failure with preserved ejection fraction: an updated systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Optimal treatment strategies for patients with heart failure with preserved ejection fraction (HFpEF) remain uncertain. The goal of this study was to compare the treatment effects of different therapeutic agents for patients with HFpEF. METHODS: Randomized controlled trials (RCTs) published before June 2022 were searched from PubMed, Clinical Trials gov, and the Cochrane Central Register databases. Combined odds ratios (ORs) with 95% confidence intervals (CI) were calculated for the primary and secondary outcomes. All-cause death was the primary endpoint and cardiac death, hospitalization for HF, and worsening HF (WHF) events were secondary endpoints in this meta-analysis. RESULTS: Fifteen RCTs including 31,608 patients were included in this meta-analysis. All-cause and cardiac death were not significantly correlated between drug treatments and placebo. Compared with placebo, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor neprilysin inhibitors (ARNIs), and sodium-glucose cotransporter-2 (SGLT2) inhibitors significantly reduced HF hospitalizations [odds ratio (OR) = 0.64, (95% confidence interval (95%CI 0.43 - 0.96), OR = 0.73, (95%CI 0.61 - 0.86), and OR = 0.74, (95%CI 0.66 - 0.83), respectively] without heterogeneity among studies. Only SGLT2 inhibitors significantly reduced WHF events [OR = 0.75, (95%CI 0.67 - 0.83)]. CONCLUSIONS: No treatments were effective in reducing mortality, but ARNIs, ACEIs or SGLT2 inhibitors reduced HF hospitalizations and only SGLT2 inhibitors reduced WHF events for patients with HFpEF.