Molecular and Cellular Biochemistry最新文献

Previous studies have demonstrated that the USP14 inhibitor IU1 and USP14/UCHL5 inhibitor b-AP15 can extend the survival period of TP53-deficient mice with spontaneous osteosarcoma (OS). However, the underlying molecular mechanisms remain to be fully elucidated. The transmembrane protein TMEM158 has been identified as a key regulator in the progression of various cancers. Nevertheless, its functional role in OS remains largely unknown. In this study, we conducted comprehensive bioinformatics analyses-including cluster analysis, differential expression analysis, and functional enrichment analysis-on clinical OS databases to assess the correlation between TMEM158 expression and the proteasome-associated USP14 and UCHL5. Primary tumor cells (TP53-deficient OS cells), SAOS-2 and U-2OS cells were treated with IU1 or b-AP15, respectively. The expression levels of TMEM158 were quantified using qPCR. Subsequently, TMEM158 was knocked down in three cell lines, and subsequent changes in cellular activity and TGF-β signaling were evaluated. Concurrently, single-cell RNA sequencing data were analyzed to identify cell types exhibiting high TMEM158 expression and to explore their associated intercellular communication patterns. Both IU1 and b-AP15 significantly prolonged the survival of TP53-deficient OS mice and exhibited enhanced cytotoxic effects on TP53-deficient OS cells. These compounds selectively suppressed TMEM158 expression in TP53-deficient primary OS and SAOS-2 cells. Bioinformatics analysis revealed that TMEM158 is positively correlated with USP14 and UCHL5 expression and serves as an independent prognostic marker for poor clinical outcomes in OS patients. Experimental validation showed that TMEM158 knockdown significantly reduced the viability of TP53-deficient primary OS and SAOS-2 cells, and inhibited TGF-β pathway activation. Osteoblastic OS cells displayed concurrent suppression of the P53 pathway and activation of the TGF-β pathway, with a strong covariant relationship between TMEM158 and activity of TGF-β pathway. Meanwhile, there may be intercellular TGF-β signaling communication between osteoblastic OS cells with high expression levels of TMEM158 and macrophages. Our findings demonstrated that the TMEM158-TGF-β pathway plays a central role in mediating the heightened sensitivity of TP53-deficient OS to USP14 inhibition. Targeting this pathway may represent a promising therapeutic strategy for precision treatment of osteosarcoma.

MicroRNAs mediate the protective effects of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) against myocardial injury. This study aimed to elucidate the specific role of exosomal miR-125b-5p in ischemic myocardial injury, focusing on its regulatory interaction with B-cell translocation gene 2 (BTG2). Murine BMSCs were transfected with miR-125b-5p inhibitor or negative-control (NC) oligonucleotides and then used to generate miR-125b-5p-knockdown (miR-125b-5p^KD)-Exos or NC-Exos under hypoxic condition. In vivo, myocardial infarction (MI) was induced by LAD ligation, followed by intramyocardial injection with 50 μl of PBS, or containing 200 μg of NC-Exos, or miR-125b-5p^KD-Exos. In vitro, HL-1 cells were treated with NC-Exos or miR-125b-5p^KD-Exos at a final concentration of 50 μg/ml under hypoxia/serum-deprived (HSD) condition. Cell apoptosis, inflammation, fibrosis, cardiac function and BTG2 expression were assessed. Exosomes uptake was detected by fluorescence microscopy after exosomes labeled with DiD dye were injected into ischemic myocardium or co-cultured with HL-1 cells under HSD condition. Dual-luciferase reporter assay was applied to validate miR-125b-5p/BTG2 interaction. When compared with group MI, treatment with NC-Exos significantly alleviated the inflammatory response (inflammation score: 1.70 ± 0.37 vs. 3.47 ± 0.22, P < 0.01), inhibited cardiac fibrosis (fibrotic area ratio: 15.98% ± 2.79% vs. 31.55% ± 3.54%, P < 0.01), and improved cardiac function (ejection fraction: 49.48% ± 6.43% vs. 29.35% ± 5.79%, P < 0.01 and fractional shortening: 30.88% ± 3.70% vs. 16.15 ± 2.72%, P < 0.01). NC-Exos reduced the cell apoptosis by 41.5% in vivo (18.00% ± 3.74% vs. 30.75% ± 3.86%, P < 0.01) when compared with group MI and by 52.2% in vitro (10.48% ± 1.80% vs. 21.93% ± 1.76%, P < 0.001) when compared with group HSD. Treatment with NC-Exos also resulted in remarkable down-regulation of BTG2 expression. The knockdown of miR-125b-5p weakened these protective effects of NC-Exos. The effective uptake of DiD-labeled exosomes by ischemic myocardium and HL-1 cells were confirmed by fluorescence microscopy. Dual-luciferase reporter assay further confirmed that BTG2 is the target of miR-125b-5p. BMSC-derived exosomes confer cardioprotection, at least in part, by transferring miR-125b-5p into cardiomyocytes to target BTG2.

Myelosuppression, a dose-limiting toxicity affecting a substantial proportion of chemotherapy patients globally (Wilson et al in Lancet Oncol 20(6):769-780, 2019. https://doi.org/10.1016/S1470-20451930163-9) remains a major clinical barrier to curative intent therapies and long-term survival. It leads to treatment delays, dose reductions, infection-related morbidity, and mortality, thereby imposing substantial healthcare burdens and diminishing patient quality of life. Here, we integrate recent metabolomics-driven discoveries to characterize chemotherapy- and radiotherapy-induced metabolic dysregulation across glucose, amino acid, lipid, and mitochondrial pathways and delineate how these alterations impair hematopoietic stem cell (HSC) function and disrupt the bone marrow microenvironment. We further connect metabolic perturbations with functional consequences, including HSC quiescence loss, oxidative stress, stromal niche remodeling, and immune dysregulation. We highlight emerging metabolite-based biomarkers, metabolic checkpoints, and nutrient-targeted therapeutic strategies capable of preventing or mitigating myelosuppression. In addition, we discuss metabolic-pathway-specific interventions, such as amino acid deprivation therapy, ketone-mediated hematopoietic protection, and mitochondrial stress modulation, emphasizing the translational potential of precision metabolic monitoring. Our analysis underscores the central role of precision metabolomics in predicting, stratifying, and reducing treatment-related hematotoxicity, providing a mechanistic and clinically actionable framework for improving therapeutic tolerance. This metabolomics-centered perspective supports individualized intervention strategies that may ultimately enhance therapeutic index and reduce hematological complications.

Leber congenital amaurosis type 2 (LCA2) is an inherited retinal disorder, with severe vision impairment in children, progressing to complete blindness in the later stages of life. The current approved treatment involves Adeno-associated virus (AAV) vector serotype 2-based subretinal delivery of human RPE65 gene. However, long-term follow-up have reported gradual loss of phenotypic response. To overcome this, we have pursued strategies aimed at improving the transduction efficacy of the vector, optimizing the transgene for enhanced protein expression and co-delivering the therapeutic vector along with the anti-apoptotic factor, Survivin /baculoviral IAP repeat containing 5 (BIRC5) gene in the neural retina. We tested the efficacy of modified RPE65 transgene (Kozak/ codon optimized [CodOpt]) carried by an improved AAV2 vector (AAV2K665Q) against RPE65 wild type (WT) and observed that vector carrying CodOptRPE65 performed 1.8-fold better in vitro. Subsequently, the codon optimized RPE65 transgene containing vector was evaluated in a pre-clinical mouse model of LCA2 (rd12) with co-delivery of Survivin in an AAV5 vector. Animals were monitored for up to 6 months, and electroretinography revealed improved A- and B-wave response of 2.57- fold and 1.76-fold, respectively in combination treated eyes (CodOptRPE65 + Survivin) as compared to mock group. Co-delivery of CodOptRPE65 + Survivin did not significantly enhance retinal function by ERG when compared to AAV2K665Q-CMV-codon-optimized RPE65 alone. However, immunohistochemistry revealed that expression of apoptotic marker Bax is significantly reduced and anti-apoptotic marker Bcl2 significantly increased in animals receiving the combination therapy. A TUNEL assay further confirmed the decrease in apoptosis in the combination treatment group. These findings suggest that incorporating anti-apoptotic factors may strengthen the phenotypic rescue and control degeneration of the neural retina in LCA2 patients, offering a promising avenue for future clinical implementation.