TSPO exacerbates acute cerebral ischemia/reperfusion injury by inducing autophagy dysfunction.

Autophagy is considered a double-edged sword, with a role in the regulation of the pathophysiological processes of the central nervous system (CNS) after cerebral ischemia-reperfusion injury (CIRI). The 18-kDa translocator protein (TSPO) is a highly conserved protein, with its expression level in the nervous system closely associated with the regulation of pathophysiological processes. In addition, the ligand of TSPO reduces neuroinflammation in brain diseases, but the potential role of TSPO in CIRI is largely undiscovered. On this basis, we investigated whether TSPO regulates neuroinflammatory response by affecting autophagy in microglia. In our study, increased expression of TSPO was detected in rat brain tissues with transient middle cerebral artery occlusion (tMCAO) and in BV2 microglial cells exposed to oxygen-glucose deprivation or reoxygenation (OGD/R) treatment, respectively. In addition, we confirmed that autophagy was over-activated during CIRI by increased expression of autophagy activation related proteins with Beclin-1 and LC3B, while the expression of p62 was decreased. The degradation process of autophagy was inhibited, while the expression levels of LAMP-1 and Cathepsin-D were significantly reduced. Results of confocal laser microscopy and transmission electron microscopy (TEM) indicated that autophagy flux was disordered. In contrast, inhibition of TSPO prevented autophagy over-activation both in vivo and in vitro. Interestingly, suppression of TSPO alleviated nerve cell damage by reducing reactive oxygen species (ROS) and pro-inflammatory factors, including TNF-α and IL-6 in microglia cells. In summary, these results indicated that TSPO might affect CIRI by mediating autophagy dysfunction and thus might serve as a potential target for ischemic stroke treatment.

An immunogenic cell death-related regulators classification patterns and immune microenvironment infiltration characterization in intracranial aneurysm based on machine learning.

Background: Immunogenic Cell Death (ICD) is a novel way to regulate cell death and can sufficiently activate adaptive immune responses. Its role in immunity is still emerging. However, the involvement of ICD in Intracranial Aneurysms (IA) remains unclear. This study aimed to identify biomarkers associated with ICDs and determine the relationship between them and the immune microenvironment during the onset and progression of IA. Methods: The IA gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) in IA were identified and the effects of the ICD on immune microenvironment signatures were studied. Techniques like Lasso, Bayes, DT, FDA, GBM, NNET, RG, SVM, LR, and multivariate analysis were used to identify the ICD gene signatures in IA. A consensus clustering algorithm was used for conducting the unsupervised cluster analysis of the ICD patterns in IA. Furthermore, enrichment analysis was carried out for investigating the various immune responses and other functional pathways. Along with functional annotation, the weighted gene co-expression network analysis (WGCNA), protein-protein interaction (PPI) network and module construction, identification of the hub gene, and co-expression analysis were also carried out. Results: The above techniques were used for establishing the ICD gene signatures of HMGB1, HMGN1, IL33, BCL2, HSPA4, PANX1, TLR9, CLEC7A, and NLRP3 that could easily distinguish IA from normal samples. The unsupervised cluster analysis helped in identifying three ICD gene patterns in different datasets. Gene enrichment analysis revealed that the IA samples showed many differences in pathways such as the cytokine-cytokine receptor interaction, regulation of actin cytoskeleton, chemokine signaling pathway, NOD-like receptor signaling pathway, viral protein interaction with the cytokines and cytokine receptors, and a few other signaling pathways compared to normal samples. In addition, the three ICD modification modes showed obvious differences in their immune microenvironment and the biological function pathways. Eight ICD-regulators were identified and showed meaningful associations with IA, suggesting they could severe as potential prognostic biomarkers. Conclusions: A new gene signature for IA based on ICD features was created. This signature shows that the ICD pattern and the immune microenvironment are closely related to IA and provide a basis for optimizing risk monitoring, clinical decision-making, and developing novel treatment strategies for patients with IA.

Effect of hemodynamic changes on the risk of intracranial aneurysm rupture: a systematic review and meta-analysis.

OBJECTIVE: In this study, the hemodynamic parameters of ruptured intracranial aneurysms (IAs) in various studies were summarized and analyzed to provide predictive parameters for IA rupture in clinical work. METHODS: We searched PubMed, Web of science, Embase, and Cochrane databases for articles published before December 2021 to collect data on hemodynamic parameters associated with IA rupture. Differences in wall shear stress (WSS), oscillatory shear index (OSI), and low wall shear stress area (LSA) between ruptured and unruptured IAs in the literature were summarized and analyzed, and the standardized mean difference (SMD) of 95% CI was calculated by Review Manager 5.3. RESULTS: By searching and screening the literature, this meta-analysis included 17 studies comprising 1,373 IA patients. In the ruptured aneurysm group, the level of WSS decreased significantly, while OSI and LSA increased obviously. CONCLUSION: Low WSS, high OSI, and high LSA are closely related to the rupture of IAs, indicating the role of WSS, OSI, and LSA as important hemodynamic parameters for predicting the rupture of IAs in clinical work.

m6A regulator-mediated RNA methylation modification patterns and immune microenvironment infiltration characterization in patients with intracranial aneurysms.

Background: The role of epigenetic modulation in immunity is receiving increased recognition-particularly in the context of RNA N6-methyladenosine (m6A) modifications. Nevertheless, it is still uncertain whether m6A methylation plays a role in the onset and progression of intracranial aneurysms (IAs). This study aimed to establish the function of m6A RNA methylation in IA, as well as its correlation with the immunological microenvironment. Methods: Our study included a total of 97 samples (64 IA, 33 normal) in the training set and 60 samples (44 IA, 16 normal) in the validation set to systematically assess the pattern of RNA modifications mediated by 22 m6A regulators. The effects of m6A modifications on immune microenvironment features, i.e., immune response gene sets, human leukocyte antigen (HLA) genes, and infiltrating immune cells were explored. We employed Lasso, machine learning, and logistic regression for the purpose of identifying an m6A regulator gene signature of IA with external data validation. For the unsupervised clustering analysis of m6A modification patterns in IA, consensus clustering methods were employed. Enrichment analysis was used to assess immune response activity along with other functional pathways. The identification of m6A methylation markers was identified based on a protein-protein interaction network and weighted gene co-expression network analysis. Results: We identified an m6A regulator signature of IGFBP2, IGFBP1, IGF2BP2, YTHDF3, ALKBH5, RBM15B, LRPPRC, and ELAVL1, which could easily distinguish individuals with IA from healthy individuals. Unsupervised clustering revealed three m6A modification patterns. Gene enrichment analysis illustrated that the tight junction, p53 pathway, and NOTCH signaling pathway varied significantly in m6A modifier patterns. In addition, the three m6A modification patterns showed significant differences in m6A regulator expression, immune microenvironment, and bio-functional pathways. Furthermore, macrophages, activated T cells, and other immune cells were strongly correlated with m6A regulators. Eight m6A indicators were discovered-each with a statistically significant correlation with IA-suggesting their potential as prognostic biological markers. Conclusion: Our study demonstrates that m6A RNA methylation and the immunological microenvironment are both intricately correlated with the onset and progression of IA. The novel insight into patterns of m6A modification offers a foundation for the development of innovative treatment approaches for IA.

Diagnosis, treatment, and misdiagnosis analysis of 28 cases of central nervous system echinococcosis.

BACKGROUND: To explore central nervous system (CNS) involvement in this disease, from the perspectives of diagnosis, treatment, and misdiagnosis METHODS: Twenty-eight patients with CNS echinococcosis were included in this retrospective study, including 18 males (64.3%) and 10 (35.7%) females. The average age of all the patients were 23.5 years (ranged 4-60 years). Twenty-three (23) patients (82.1%) received the first surgical resection in our hospital. Five (5) patients (17.9%) gave up surgical treatment for multiple-organ hydatidosis and previous surgery history at other hospitals, and albendazole was applied for a long-term (3-6 months) adjunct therapy for the 5 patients. The average follow-up time was 8 years. RESULTS: For the 28 patients, 23 cases received surgical treatments, and the diagnosis was confirmed by pathological examinations. The diagnosis of 4 cases of brain echinococcosis and 2 cases of spinal cord echinococcosis could not be confirmed, resulting in a misdiagnosis rate of 21.4% (6/28). For the pathological examination, a total of 17 cases were infected with Echinococcus granulosus (including 2 cases of spinal cord echinococcosis), and 6 cases were infected with Echinococcus alveolaris. CONCLUSION: The diagnosis should be specifically considered in endemic regions. The clinical features of CNS hydatidosis were intracranial space-occupying lesions. For the treatment, the surgical removal of cysts should be necessary. In addition, the adjuvant therapy with drug and intraoperative prophylaxis is also suggested. The misdiagnosis may have resulted from atypical clinical features and radiographic manifestations, as well as the accuracy of hydatid immunologic test.

Identification of potential key pathways, genes and circulating markers in the development of intracranial aneurysm based on weighted gene co-expression network analysis.

Background: Intracranial aneurysm (IA) is a disease resulted from weak brain control, characterized by local expansion or dilation of brain artery. This study aimed to construct a gene co-expression network by Weighted Gene Correlation Network Analysis (WGCNA) to explore the potential key pathways and genes for the development of IA.Method: Six IA-related gene expression data sets were downloaded from the Gene Expression Omnibus (GEO) database for identifying differentially expressed genes (DEGs). WGCNA was used to identify modules associated with IA. Functional enrichment analysis was used to explore the potential biological functions. ROC analysis was used to find markers for predicting IA.Results: Purple, greenyellow and yellow modules were significantly associated with unruptured intracranial aneurysms, while blue and turquoise modules were significantly associated with ruptured intracranial aneurysms. Functional modules significantly related to IA were enriched in Ribosome, Glutathione metabolism, cAMP signalling pathway, Lysosome, Glycosaminoglycan degradation and other pathways. CD163, FCEREG, FPR1, ITGAM, NLRC4, PDG, and TYROBP were up-regulated ruptured intracranial aneurysms and serum, these genes were potential circulating markers for predicting IA rupture.Conclusions: Potential IA-related key pathways, genes and circulating markers were identified for predicting IA rupture by WGCNA analysis.

Comparison of administration routes for adipose-derived stem cells in the treatment of middle cerebral artery occlusion in rats.

Given that adult adipose tissue is an abundant, accessible and safe source of stem cells, the use of adipose-derived stem cells (ADSCs) provides a promising approach in ischemic stroke. The delivery route, however, for transplantation of ADSCs in clinical application remains controversial regarding the time window, cell type, safety issues, 'first pass' effect and therapeutic effect. To determine the optimal administration route in transplantation of ADSCs, we compared the therapeutic effect of the three mainly used administration routes of ADSCs in a middle cerebral artery occlusion (MCAO) rat model. Cells isolated from the adipose tissue of adult rodents were differentiated and characterized in vitro, and further transplanted in vivo by intravenous, intra-arterial or intra-ventricular delivery. The infarct volume, expression of neurotrophic factors and the neurobehavioral improvements were evaluated after the equal dose of BrdU labeled ADSCs transplantation. Our results indicated that the equal dose of ADSCs delivered intravenously were effective in improving the neurological outcome and reducing the infarct volume after ischemic brain injury in long term duration in contrast to intra-arterial and intra-ventricular delivery. At 1-7 days after transplantation, the increased expression levels of BDNF, VEGF, bFGF, Bcl-2, IL-10 and decreased levels of caspase-3 and TNF-α in the intra-ventricular and intra-arterial groups were significant in contrast to the intravenous group. There was no significant difference among the three groups after 7 days. Our findings suggest that compared with the intra-ventricular delivery, intravascular injection allows higher dose injection with fewer invasions and appears to be optimal in application with regard to therapeutic efficacy, safety and feasibility.