SIRT5 Regulates Ferroptosis through the Nrf2/HO-1 Signaling Axis to Participate in Ischemia-Reperfusion Injury in Ischemic Stroke.

This work aimed to study the role and mechanism of SIRT5 regulation of ferroptosis in cerebral ischemia-reperfusion (I/R) injury. A model of middle cerebral artery occlusion in rats was prepared using the method of thread occlusion. The ferroptosis inhibitor was injected intraperitoneally while the SIRT5 interfering lentivirus were injected into the brain, and neurological disorders were scored in the rats. TTC staining was used to detect infarct volume, and immunohistochemistry was used to detect the expression of SIRT5 in tissues. Rat hippocampal neuronal cells H19-7 were transduced with SIRT5 interfering lentivirus and ferroptosis was induced using erastin. The CCK8 detection kit was used to detect cell viability. Commercial kits were used to detect levels of iron ions, ROS, MDA, SOD, and inflammatory factor (TNF-α and IL-6) in brain tissue or cell supernatant. Western blot was used to detect the expression changes of ferroptosis related proteins GPX4, Nrf2, and HO-1 in tissues or cells. Compared with the sham group, the MCAO model group showed higher levels of neurological impairment score, increased cerebral infarction volume, iron ions, inflammatory factors, and oxidative stress levels in rats. Compared with the MCAO group, the MCAO + fer-1 group exhibited lower levels of neurological impairment scores, cerebral infarction volume, decreased iron ions, inflammatory factors, and oxidative stress levels in rats. Meanwhile, compared with the MCAO + DMSO/LV-shRNA group, the MCAO + fer-1/LV-shSIRT5 group showed a significant decrease in neurological impairment scores, cerebral infarction volume, iron ions, inflammatory factors, and oxidative stress levels in rats. In vitro experiments have found that LV-shSIRT5 can prevent erastin-induced cell ferroptosis. In summary, SIRT5 regulates ferroptosis through the Nrf2/HO-1 signaling axis to participate in ischemia-reperfusion injury in ischemic stroke.

Differential reinforcement of cGAS-STING pathway-involved immunotherapy by biomineralized bacterial outer membrane-sensitized EBRT and RNT.

Radiotherapy (RT), including external beam radiation therapy (EBRT) and radionuclide therapy (RNT), realizes physical killing of local tumors and activates systemic anti-tumor immunity. However, these effects need to be further strengthened and the difference between EBRT and RNT should be discovered. Herein, bacterial outer membrane (OM) was biomineralized with manganese oxide (MnO2) to obtain OM@MnO2-PEG nanoparticles for enhanced radio-immunotherapy via amplifying EBRT/RNT-induced immunogenic cell death (ICD) and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) activation. OM@MnO2-PEG can react with H2O2 and then gradually produce O2, Mn2+ and OM fragments in the tumor microenvironment. The relieved tumor hypoxia improves the radio-sensitivity of tumor cells, resulting in enhanced ICD and DNA damage. Mn2+ together with the DNA fragments in the cytoplasm activate the cGAS-STING pathway, further exhibiting a positive role in various aspects of innate immunity and adaptive immunity. Besides, OM fragments promote tumor antigen presentation and anti-tumor macrophages polarization. More importantly, our study reveals that OM@MnO2-PEG-mediated RNT triggers much stronger cGAS-STING pathway-involved immunotherapy than that of EBRT, owing to the duration difference of RT. Therefore, this study develops a powerful sensitizer of radio-immunotherapy and uncovers some differences between EBRT and RNT in the activation of cGAS-STING pathway-related anti-tumor immunity.

Association Between Diverse Cell Death Patterns Related Gene Signature and Prognosis, Drug Sensitivity, and Immune Microenvironment in Glioblastoma.

Glioblastoma (GBM) is the most invasive type of glioma and is difficult to treat. Diverse programmed cell death (PCD) patterns have a significant association with tumor initiation and progression. A novel prognostic model based on PCD genes may serve as an effective tool to predict the prognosis of GBM. The study incorporated 11 PCD patterns, namely apoptosis, necroptosis, pyroptosis, ferroptosis, cuproptosis, entotic cell death, netotic cell death, parthanatos, lysosome-dependent cell death, autophagy-dependent cell death, alkaliptosis, and oxeiptosis, to develop the model. To construct and validate the model, both bulk and single-cell transcriptome data, along with corresponding clinical data from GBM cases, were obtained from the TCGA-GBM, REMBRANDT, CGGA, and GSE162631 datasets. A cell death-related signature containing 14 genes was constructed with the TCGA-GBM cohort and validated in the REMBRANDT and CGGA datasets. GBM patients with a higher cell death index (CDI) were significantly associated with poorer survival outcomes. Two separate clusters associated with clinical outcomes emerged from unsupervised analysis. A multivariate Cox regression analysis was conducted to examine the association of CDI with clinical characteristics, and a prognostic nomogram was developed. Drug sensitivity analysis revealed high-CDI GBM patients might be resistant to carmustine while sensitive to 5-fluorouracil. Less abundance of natural killer cells was found in GBM cases with high CDI and bulk transcriptome data. A cell death-related prognostic model that could predict the prognosis of GBM patients with good performance was established, which could discriminate between the prognosis and drug sensitivity of GBM.

Dysregulation of LINC00324 promotes poor prognosis in patients with glioma.

BACKGROUND: LINC00324 is a long-stranded non-coding RNA, which is aberrantly expressed in various cancers and is associated with poor prognosis and clinical features. It involves multiple oncogenic molecular pathways affecting cell proliferation, migration, invasion, and apoptosis. However, the expression, function, and mechanism of LINC00324 in glioma have not been reported. MATERIAL AND METHODS: We assessed the expression of LINC00324 of LINC00324 in glioma patients based on data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) to identify pathways involved in LINC00324-related glioma pathogenesis. RESULTS: Based on our findings, we observed differential expression of LINC00324 between tumor and normal tissues in glioma patients. Our analysis of overall survival (OS) and disease-specific survival (DSS) indicated that glioma patients with high LINC00324 expression had a poorer prognosis compared to those with low LINC00324 expression. By integrating clinical data and genetic signatures from TCGA patients, we developed a nomogram to predict OS and DSS in glioma patients. Gene set enrichment analysis (GSEA) revealed that several pathways, including JAK/STAT3 signaling, epithelial-mesenchymal transition, STAT5 signaling, NF-κB activation, and apoptosis, were differentially enriched in glioma samples with high LINC00324 expression. Furthermore, we observed significant correlations between LINC00324 expression, immune infiltration levels, and expression of immune checkpoint-related genes (HAVCR2: r = 0.627, P = 1.54e-77; CD40: r = 0.604, P = 1.36e-70; ITGB2: r = 0.612, P = 6.33e-7; CX3CL1: r = -0.307, P = 9.24e-17). These findings highlight the potential significance of LINC00324 in glioma progression and suggest avenues for further research and potential therapeutic targets. CONCLUSION: Indeed, our results confirm that the LINC00324 signature holds promise as a prognostic predictor in glioma patients. This finding opens up new possibilities for understanding the disease and may offer valuable insights for the development of targeted therapies.