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Postmenopausal osteoporosis (OP) is a prevalent skeletal disease with not fully understood molecular mechanisms. This study aims to investigate the role of circular RNA (circRNA) in postmenopausal OP and to elucidate the potential mechanisms of the circRNA--miRNA--mRNA regulatory network. We obtained circRNA and miRNA expression profiles from postmenopausal OP patients from the Gene Expression Omnibus database. By identifying differentially expressed circRNAs and miRNAs, we constructed a circRNA--miRNA--mRNA network and identified key genes associated with OP. Further, through a range of experimental approaches, including dual-luciferase reporter assays, RNA pull-down experiments, and qRT-PCR, we examined the roles of circ_0134120, miR-590-5p, and STAT3 in the progression of OP. Our findings reveal that the interaction between circ_0134120 and miR-590-5p in regulating STAT3 gene expression is a key mechanism in OP, suggesting the circRNA--miRNA--mRNA network is a potential therapeutic target for this condition. [ABSTRACT FROM AUTHOR]

Carbamazepine (CBZ), an anticonvulsant and mood-stabilizing pharmaceutical, is a widespread contaminant in aquatic environments. In this study, the effects of chronic exposure to environmentally relevant CBZ concentrations were investigated in freshwater clams Corbicula fluminea. Adult C. fluminea were exposed to 0.5, 5, and 50 µg/L of CBZ for 30 days, after which siphoning behavior (filtration rates), biomarker levels, and heat shock protein expression were measured. The filtration rates were significantly decreased (p < 0.05) by 50 µg/L CBZ treatment, indicating a negative impact on C. fluminea health. Superoxide dismutase (SOD) and glutathione reductase (GR) activities were decreased, and catalase (CAT) activity and malondialdehyde (MDA) content were increased in the gills and digestive gland, suggesting that CBZ induced an oxidative effect. The levels of Hsp22, Hsp40, and Hsp70 mRNAs were also markedly induced after 5 or 50 µg/L CBZ treatment (p < 0.05), whereas Hsp60 and Hsp90 mRNAs in gills and Hsp60 mRNA in digestive gland were significantly repressed (p < 0.05). Finally, the expression of Hsp70 protein was significantly increased (p < 0.05) by 5 and 50 µg/L exposure. In aggregate, these results confirm that environmentally relevant concentrations of CBZ can exert a negative effect on C. fluminea tissue at the molecular and protein level. [ABSTRACT FROM AUTHOR]