Postmenopausal osteoporosis, primarily driven by estrogen deficiency, is predominantly mediated through estrogen receptors such as ERα. However, the underlying mechanisms necessitate further investigation. In this study, we established an ERα-deficient model in rBMSCs to elucidate the role of ERα in osteogenic differentiation and miRNA expression profiles. Our findings demonstrate that knockdown of ERα inhibits osteogenic differentiation in rBMSCs, resulting in upregulation of 25 miRNAs and downregulation of 184 miRNAs, including a significant increase in the expression of miR-214-3p. Validation using qPCR, Western blotting, and bioinformatics analysis revealed that miR-214-3p negatively regulates osteogenic differentiation via the Wnt/β-catenin signaling pathway. Furthermore, we explored the potential therapeutic effects of quercetin (QUE) on rBMSCs. CCK8, alkaline phosphatase activity assays, and Alizarin Red staining demonstrated that QUE dose-dependently enhances rBMSCs proliferation, alkaline phosphatase activity, and mineralization within the concentration range of 0.1-1 μM. Importantly, QUE was found to downregulate miR-214-3p expression and activate the Wnt3a/β-catenin signaling pathway. Rescue experiments confirmed that QUE could counteract the inhibitory effects of miR-214-3p on the Wnt3a/β-catenin signaling pathway. Collectively, our study provides compelling evidence that knockdown of ERα inhibits the osteogenic differentiation of rBMSCs by affecting the miRNA expression profile, while QUE can reverse the inhibitory effect exerted by miR-214-3p on the Wnt3a/β-catenin signaling pathway, thereby offering novel insights into diagnosis, prevention, and treatment strategies for postmenopausal osteoporosis.

The role of estrogen receptor β (ERβ) in bone health is closely associated with its function in vivo, and ERβ^−/− mice have been widely utilized to explore the related influences. In this study, ERβ^−/− female mice were established to investigate the differential expression of circular RNAs (circRNAs) by RNA-Sequencing (RNA-Seq). Among these circRNAs, mmu_circ_0011379 (named Circ-Spen) exhibited high expression in ERβ^−/− female mice. However, the precise mechanism by which Circ-Spen regulates bone health remained unclear. This study identified Circ-Spen as a positive regulator of mouse bone marrow mesenchymal stem cell (mBMSC) viability. The expression of Circ-Spen was markedly increased in ERβ^−/− mice femurs tested by RT-qPCR. Moreover, Circ-Spen exhibited an enhanced expression during the bone formation process of mBMSCs. Qualitative experiments also demonstrated that Circ-Spen possessed a circular structure and was localized within the nucleus of mBMSCs. Functionally, it inhibited apoptosis via caspase-3, BCL-2, and BAX, while also promoting autophagy through BECN1 and P62 in mBMSCs tested by MTT assays, transmission electron microscopy (TEM), and Western blotting. These findings reveal the potential of targeting Circ-Spen as a promising therapeutic strategy for rejuvenating senescent mBMSCs and enhancing the efficiency of mBMSC transplantation, which lays the foundation for advancements in the field of bone therapy.

Colorectal cancer (CRC) ranks as the third most diagnosed cancer and the second leading cause of cancer-related mortality globally. Hexokinase II, a key rate-limiting enzyme in tumor glycolysis, is an important therapeutic target. In this study, we report that baicalin, a flavonoid derived from Scutellaria baicalensis , acts as a HK2 inhibitor and exerts anti–colorectal cancer activity. In vitro , baicalin markedly suppressed colorectal cancer cell proliferation and colony formation. Molecular docking, molecular dynamics simulations, DARTS, and CETSA suggest an association between baicalin and HK2, while MG132 rescue and HK2 immunoprecipitation indicate that baicalin promotes ubiquitination-associated proteasomal degradation of HK2. Mechanistically, baicalin inhibits HK2, reduces glycolysis, and causes mitochondrial damage, thereby activating the cGAS/STING innate immune signaling pathway and increasing IFN-β production. IFN-β contributes to reshaping the tumor immune microenvironment. In an MC38 syngeneic tumor model, baicalin significantly inhibited tumor growth, reduced HK2 protein levels, activated the cGAS/STING pathway, and promoted a shift in tumor-associated macrophages toward an M1-like polarization state. Collectively, this study uncovers a novel strategy for targeting HK2 to regulate both tumor cell metabolism and the immune microenvironment, providing a potential therapeutic approach for colorectal cancer.