Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025014
Ferroptosis is a novel form of regulated cell death characterized by the iron-dependent accumulation of lipid peroxides. Recent research has suggested that ferroptosis in osteoblasts contributes to steroid-induced osteonecrosis of the femoral head (SONFH). However, the relationship between ferroptosis and SONFH remains unclear. In this study, in vitro experiments show that dexamethasone (Dex) treatment reduces the expressions of key ferroptosis regulators, SLC7A11 and GPX4, in MC3T3-E1 cells. This reduction leads to a decrease in intracellular glutathione (GSH) levels, accompanied by elevated levels of total iron, malondialdehyde (MDA), and reactive oxygen species (ROS). Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively reverses Dex-induced ferroptosis in MC3T3-E1 cells. Furthermore, RNA-seq analysis reveals that the long noncoding RNA (lncRNA) XR_877193.1 is significantly upregulated in Dex-treated MC3T3-E1 cells. Functional studies demonstrate that the knockdown of lncRNA XR_877193.1 promotes osteogenic differentiation by inhibiting Dex-induced ferroptosis in MC3T3-E1 cells, whereas its overexpression exacerbates cell death via ferroptosis. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis reveals that the differentially expressed lncRNA XR_877193.1 is enriched in ferroptosis-related pathways, including the PI3K/AKT signaling pathway. Moreover, PI3K/AKT inhibitors reverse ferroptosis in MC3T3-E1 cells inhibited by lncRNA XR_877193.1 knockdown. Collectively, our findings indicate that lncRNA XR_877193.1 knockdown exerts anti-ferroptosis effects by stimulating the PI3K/AKT signaling pathway, suggesting a promising therapeutic strategy for attenuating SONFH.
Acta Biochimica et Biophysica Sinica•2026•DOI: 10.3724/abbs.2025114
Bladder cancer (BCa) is one of the most common malignant tumors of the urinary system, but its pathogenesis is still unclear. T1G3 BCa is particularly invasive and relapses readily after treatment, with progression to invasive cancer or distant metastasis. Therefore, identification of the molecular mechanism by which it invades and metastasizes to guide treatment and predict patient prognosis is needed. Cofilin1 plays an important role in regulating gene expression and the invasiveness of tumors. In this study, we show that Cofilin1 is highly expressed in BCa and lymph nodes with metastasis, which is positively related to the grade of BCa, and is significantly related to clinicopathological parameters and cancer-specific survival. Phenotypic analysis reveals that Cofilin1 knockout inhibits the proliferation and migration of BCa cells, whereas Cofilin1 overexpression promotes the opposite phenotype. Cofilin1 binds to cortactin, thereby reducing the expression of F-actin and promoting the formation of invadopodia in BCa cells. Further experiments reveal that TCF7L2 can bind to the promoter of Cofilin1 and transactivate it, promoting a malignant phenotype. TCF7L2 may also reverse the inhibitory effect of miR-206 on the binding of Cofilin1 and cortactin and promote the metastasis of BCa by inhibiting the transcription maturation of miR-206. This study confirms that Cofilin1 is an oncogene in T1G3 BCa, and the TCF7L2/miR-206/Cofilin1 signaling pathway plays an important role in the formation of invadopodia in BCa.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024024
Myocardial ischemia/reperfusion (I/R) injury is a classic type of cardiovascular disease characterized by injury to cardiomyocytes leading to different types of cell death. The degree of irreversible myocardial damage is closely related to age, and ferroptosis is involved in cardiomyocyte damage. However, the mechanisms underlying ferroptosis regulation in aging myocardial I/R injury are still unclear. The present study aims to explore the underlying mechanism of piRNA regulation in ferroptosis. Using left anterior descending coronary artery ligation in an aging rat model and a D-galactose-induced rat cardiomyocyte line (H9C2) to construct an aging cardiomyocyte model, we investigate whether ferroptosis occurs after reperfusion injury in vitro and in vivo. This study focuses on the upregulation of piR-000699 after hypoxia/reoxygenation treatment in aging cardiomyocytes by observing hypoxia/reoxygenation (H/R) injury indicators and ferroptosis-related indicators and clarifying the role of piR-000699 in H/R injury caused by ferroptosis in aging cardiomyocytes. Bioinformatics analysis reveals that SLC39A14 is a gene that binds to piR-000699. Our data show that ferroptosis plays an important role in I/R injury both in vivo and in vitro. Furthermore, the results show the potential role of piR-000699 in regulating SLC39A14 in ferroptosis in aging cardiomyocytes under hypoxia/reoxygenation conditions. Together, our results reveal that the mechanism by which piR-000699 binds to SLC39A14 regulates ferroptosis in aging myocardial I/R injury.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024096
Autophagy is a cellular mechanism for self-renewal that involves the breakdown of cytoplasmic proteins or organelles within lysosomes. Although preeclampsia (PE) exhibits several characteristics that could imply disrupted autophagy, there is limited evidence supporting the notion that impaired placental autophagy directly causes PE, as indicated by differential expression profiling of whole placental tissue. In this study, we aim to explore the significance of autophagy in maintaining pregnancy and its association with PE. First, the RNA-seq results show that 218 genes are differentially expressed in placentas from preeclamptic pregnancies. Notably, KEGG pathway analysis reveals significant enrichment of genes related to autophagy-related signaling pathways, including the PI3K-Akt signaling pathway, the AMPK signaling pathway, and the mTOR signaling pathway. Additionally, our findings indicate an increase in autophagy in placentas from pregnancies complicated by preeclampsia as well as in trophoblasts subjected to hypoxic conditions. Next, we examine the impact of 3-methyladenine (3-MA), a targeted inhibitor of autophagy, on the progression of PE. The administration of 3-MA profoundly alleviates the severity of PE-like symptoms in rats subjected to reduced uterine perfusion pressure (RUPP). The findings from our study suggest that inhibiting autophagy may serve as a promising approach for adjuvant chemotherapy for PE.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025096
Ferroptosis, a novel form of regulated necrosis, has drawn the attention of the scientific community. Nevertheless, few studies have focused on the impact of ferroptosis on MC3T3-E1 cells in the context of steroid-induced osteonecrosis of the femoral head (SONFH). In this study, we explore the relationship between the degree of ferroptosis induced by dexamethasone (Dex) and the expression of silent information regulatory protein 1 (Sirt1). The results indicate that the ferroptosis level induced by Dex is mediated by the downregulation of Sirt1. Overexpression of Sirt1 increases the levels of the ferroptosis-related proteins SLC7A11 and GPX4 in MC3T3-E1 cells following Dex exposure. Moreover, the effect of Dex on Sirt1 expression is regulated by hypermethylation of the Sirt1 promoter, which is catalyzed by DNA methyltransferase 3a (DNMT3a). In summary, this study reveals that Dex can trigger ferroptosis by promoting DNMT3a-mediated DNA methylation and downregulating Sirt1 expression. Our findings provide an additional new mechanism for Dex-induced ferroptosis in MC3T3-E1 cells.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21475
BACKGROUND: The pathogenesis of steroid-induced osteonecrosis of the femoral head remains unclear; however, it is closely associated with mitochondrial damage in osteoblasts. OBJECTIVE: To explore the impact of dexamethasone on mitochondrial dysfunction in osteoblasts following steroid-induced osteonecrosis of the femoral head and to analyze its regulatory roles in osteoblast apoptosis and autophagy. METHODS: MC3T3-E1 cells were cultured in vitro and divided into control group (no treatment) and dexamethasone group (1 μmol/L dexamethasone treatment for 24 hours). Osteoblast differentiation capacity was assessed by alizarin red staining and qRT-PCR. Mitochondrial morphology was examined using transmission electron microscopy, MitoTracker Red fluorescence staining, and flow cytometry. Mitochondrial membrane potential and energy metabolism were evaluated by JC-1 fluorescence staining and ATP content detection. Mitochondrial superoxide levels were measured using MitoSOX fluorescence probe and flow cytometry. Intracellular total reactive oxygen species and glutathione content were also measured to assess oxidative stress status. Additionally, Western blot and qRT-PCR were used to detect the expression of apoptosis-related proteins (Bax, Bcl-2) and autophagy markers (LC3B, p62), flow cytometry was used to analyze apoptosis rate, and autophagy flux was observed via mRFP-GFP-LC3 adenovirus transfection combined with confocal microscopy. RESULTS AND CONCLUSION: Compared with the control group, the dexamethasone group showed significantly reduced osteogenic differentiation capacity of MC3T3-E1 cells, abnormal mitochondrial structure (swelling, cristae disruption), decreased mitochondrial membrane potential, reduced ATP synthesis, increased mitochondrial superoxide and total reactive oxygen species levels, and increased glutathione consumption (P < 0.05). The dexamethasone group showed significantly upregulated pro-apoptotic protein Bax (P < 0.01), significantly downregulated anti-apoptotic protein Bcl-2 (P < 0.01), increased LC3B-II/I ratio (P < 0.01), and decreased p62 levels (P < 0.01); dexamethasone treatment significantly increased the apoptosis rate (P < 0.01). mRFP-GFP-LC3 adenovirus tracing revealed increased formation of autophagosomes and autolysosomes. These results indicate that dexamethasone induces mitochondrial dysfunction and oxidative stress, synergistically regulating apoptosis and autophagy in MC3T3-E1 cells, thereby impairing bone formation and repair function. This mechanism may be a key pathological basis for the pathogenesis of steroid-induced osteonecrosis of the femoral head.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025096
Steroid-induced osteonecrosis of the femoral head (SONFH) is a progressive bone disorder driven by prolonged glucocorticoid exposure, with limited therapeutic options. Ferroptosis, a regulated form of necrosis, has emerged as a potential contributor to SONFH pathogenesis, yet its mechanistic link to osteoblast dysfunction remains poorly defined. This study investigates the relationship between dexamethasone (Dex)-induced ferroptosis and silent information regulator 1 (Sirt1) in MC3T3-E1 osteoblastic cells. Dex treatment downregulated Sirt1 expression and increased ferroptosis markers, while Sirt1 overexpression elevated the ferroptosis-related proteins SLC7A11 and GPX4 following Dex exposure. Mechanistically, Dex promoted hypermethylation of the Sirt1 promoter via DNA methyltransferase 3a (DNMT3a), leading to Sirt1 suppression. These findings establish a novel epigenetic axis—DNMT3a-mediated Sirt1 promoter hypermethylation—that drives Dex-induced ferroptosis in osteoblasts. The study was conducted exclusively in vitro, and the pathophysiological relevance requires validation in animal models. Nevertheless, this work provides a foundation for understanding the epigenetic regulation of osteoblast ferroptosis and suggests potential therapeutic avenues for preventing SONFH.