Atrial Cardiomyopathy Predicts the Functional Outcome and Mortality in Stroke Patients.

AIM: Atrial cardiomyopathy (ACM) is characterized by atrial dysfunction. This study aims to assess the prognostic significance of ACM in patients with noncardioembolic stroke (NCS). METHODS: Patients with NCS within seven days of onset were prospectively enrolled between January 2019 and December 2020. ACM was defined as either an N-terminal pro-brain natriuretic peptide (NT-pro BNP) ＞250 pg/ml or a P-terminal force in precordial lead V1 (PTFV1) ≥ 5000µV·ms. A poor functional outcome was determined as a score of 3-6 on the modified Rankin Scale (mRS) within a 2-year follow-up period. Logistic regression and Cox regression analyses were employed to examine the relationship between ACM and the long-term prognosis of patients with NCS. RESULTS: A total of 1,346 patients were enrolled, of whom 299 (22.2%) patients were diagnosed with ACM. A total of 207(15.4%) patients experienced a poor functional outcome, and 58 (4.3%) patients died. A multivariate logistic regression analysis indicated that ACM was significantly associated with a poor functional outcome in NCS patients [adjusted odds ratio (aOR): 2.01; 95% confidence interval (CI): 1.42-2.87; p＜0.001]. Additionally, a multivariate Cox regression analysis showed that an NT-pro BNP ＞250 pg/ml was significantly associated with an increased risk of all-cause mortality [adjusted hazard ratio (aHR), 2.51; 95% CI: 1.42-4.43; p=0.001]. CONCLUSIONS: ACM may serve as a novel predictor of a poor long-term functional outcome in patients with NCS. Elevated NT-pro BNP levels (＞250 pg/ml) were found to be associated with a higher risk of all-cause mortality. These findings warrant further validation in multicenter studies.

Gasdermin D inhibition ameliorates neutrophil mediated brain damage in acute ischemic stroke.

Acute ischemic stroke (AIS) induces high level of neutrophils, which correlates inversely with patient survival. Pyroptosis induced by gasdermin D (GSDMD) has been shown to have an important role in the pathophysiology of several inflammatory disorders. The role of GSDMD in the high level of neutrophils after AIS is unknown. Using a middle cerebral artery occlusion (MCAO) mouse model, we identified activation of pyroptosis signal, including expression of caspase-1/11, GSDMD, and interleukin-1ß/18 (IL-1ß/18), in the brain and spleen at early ischemic injury. Knockout of GSDMD in mice reduced infarct size, improved neurological function, and increased survival after MCAO. GSDMD deficiency decreased the overall degree of inflammation and the proportion of neutrophils in the brain after MCAO. Quantitative studies of neutrophils at several time intervals and organs demonstrated that early inflammatory leucocyte production and supplement (1 day after MCAO) was GSDMD-dependent. A series of bone marrow transplantation experiments, neutrophil depletion experiments, and RNA sequencing results demonstrated that neutrophil specific GSDMD is essential for the production and supply of neutrophil in bone marrow to blood. Moreover, pharmacological suppression of GSDMD decreased pathological abnormalities, infarct volume, and ameliorated neurological function. These results provided a new viewpoint on the immunological modulation of neutrophils after MCAO and suggest that suppression of GSDMD may relieve the neuroinflammatory load, thereby providing a potential treatment strategy for stroke. The absence of GSDMD reduces the high level of neutrophils in the brain, the production of neutrophils in bone marrow, and the supply of blood and spleen, while simultaneously the neutrophil-specific GSDMD signal deficiency restrains leukocytosis to improve the pathological outcome of AIS.

Edaravone dexborneol provides neuroprotective benefits by suppressing NLRP3 inflammasome-induced microglial pyroptosis in experimental ischemic stroke.

Edaravone dexborneol (EDB) is a traditional prescription that consists of two components, edaravone and (+)-borneol, which have synergistic antioxidant and anti-inflammatory activities in animal models of ischemic stroke. Pyroptosis is a form of cell death that has only recently been discovered. In this study, we investigated the therapeutic effects and potential mechanisms of EDB in acute ischemic stroke. We used an in vivo mouse transient middle cerebral artery occlusion (tMCAO) model along with an in vitro BV2 cell oxygen-glucose deprivation (OGD) model to perform specific experiments. The executive protein of pyroptosis, gasdermin D (GSDMD), was increased after tMCAO. The administration of EDB dramatically reduced sensorimotor deficits and infarct sizes in mice with tMCAO. In addition, EDB inhibited the production of the NLRP3-inflammasome and the activation of the NF-κB signaling pathway. This effect inhibited both the in vitro and in vivo expression of inflammatory factors, including IL-1ß and IL-18. Collectively, our data indicate that EDB exerted positive effects after ischemic stroke. EDB inhibited the activation of NLRP3 inflammasome-induced microglial pyroptosis in experimental ischemic stroke. The findings of this research indicate that the NF-κB/NLRP3/GSDMD signaling pathway may serve as a therapeutic target for EDB to promote functional recovery after stroke.

Decoding the Transcriptional Response to Ischemic Stroke in Obese and Non-obese Mice Brain.

BACKGROUND: Ischemic Stroke (IS) is a serious cerebrovascular disease, which leads to irreversible damage or death of brain cells. Effective control of stroke risk factors can effectively reduce the incidence of IS. However, there was an "obesity paradox" about the relationship between obesity and the prognosis of IS, in which obesity would not bring worse outcomes than non-obese IS patients. OBJECTIVE: Herein, we aimed to investigate the transcriptional response to IS in obese and nonobese mice brain via RNA-Seq technology. The datasets of obese and non-obese mice with/without IS were obtained from the Gene Expression Omnibus (GEO) database. METHODS: Differentially expressed genes (DEGs) between Control and Obesity (DEGsObesity) and between Obesity and Obese-Stroke (DEGsObese-Stroke) were identified. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Protein-Protein Interaction (PPI) network analysis were performed to predict the function of DEGs. 28 and 109 DEGs were screened in DEGsObesity and DEGsObese-Stroke, respectively. RESULTS: Significantly, in the top 10 key-genes of DEGsObese-Stroke (Tnf, Lgals3, Serpinb2, Ly6c2, Chil3, Clec4e, Mmp3, Mefv, Spn, Tlr8), Tnf and Mefv were involved in the NOD-like receptor signaling pathway, which was consistent with KEGG pathway enrichment results. And Chil3, as a mononuclear cell marker, was significantly elevated in Obese-Stroke compared with Stroke, suggesting mononuclear cell, rather than other peripheral immune cells, infiltrated into the brain of Obese-stroke. CONCLUSION: Hence, we concluded that obesity could affect the brain microenvironment at the transcriptome level and Stroke after obesity could lead to more changes in NOD-like receptor signaling pathway and monocyte infiltration, compared with non-obese Stroke.

Regulatory T cell is critical for interleukin-33-mediated neuroprotection against stroke.

Interleukin-33 (IL-33) is known to activate the regulatory T lymphocytes (Tregs), which are negatively correlated with brain damage after ischemic stroke. In this study, we aimed to investigate the role of Tregs in IL-33-mediated neuroprotection and elucidate the underlying mechanisms. In vivo, male C57BL/6 N mice were subjected to 60 min of transient middle cerebral artery occlusion (tMCAO), followed by daily administration of vehicle or IL-33 immediately after injury. Tregs were depleted by intraperitoneal administration of anti-CD25 antibody (anti-CD25Ab). Behavioral changes, brain edema, neuronal injury, Treg percentages, and cytokine expression levels were investigated in each group. In vitro experiments, primary mouse neuronal cells were subjected to oxygen-glucose deprivation (OGD) for 3 h. Vehicle- or drug-conditioned Tregs were applied to the neurons at the time of induction of hypoxia. Neuronal apoptosis and cytokine expression were measured in each group. The results indicate that intraperitoneal administration of anti-CD25Ab reduced CD4 + CD25 + Foxp3+ Tregs, increased infarct volume, enhanced stroke-induced cell death, and decreased sensorimotor functions. Notably, IL-33 increased CD4 + CD25 + Foxp3+ Tregs in the spleen and brain. However, blockading ST2 attenuated these effects of IL-33. The supernatant of the IL-33-treated Treg culture reduced neuronal apoptosis and elevated the production of the Treg cytokines IL-10, IL-35, and transforming growth factor-ß (TGF-ß). Anti-CD25Ab abrogated the neuroprotective effect of IL-33. Mechanistically, the neuroprotective effects of IL-33 were associated with reduction in apoptosis-related proteins and production of Tregs related cytokines. Overall, these findings showed that IL-33 afforded neuroprotection against ischemic brain injury by enhancing ST2-dependent regulatory T-cell expansion and activation via a mechanism involving anti-apoptosis proteins and cytokines, representing a promising immune modulatory target for the treatment of stroke.

The Association Between Serum Apelin-13 and the Prognosis of Acute Ischemic Stroke.

While a number of studies have reported an association between apelin-13 and ischemic stroke, few have verified its clinical effect. We investigated the prognostic value of serum apelin-13 levels in patients with acute ischemic stroke (AIS). We prospectively recruited 244 AIS patients within 24 h after stroke onset, and 167 healthy controls. We assessed the serum apelin-13 levels using ELISA, and the severity of AIS using the National Institutes of Health Stroke Scale (NIHSS). The primary outcomes included death or major disability (modified Rankin Scale score, 3-6) and major disability (modified Rankin Scale score, 3-5). Secondary outcomes included recurrent stroke and combined events (all-cause death, or cardiovascular and cerebrovascular events). We found that the serum apelin-13 levels in the patients (38.63 ng/mL (interquartile range [IQR], 29.86-50.99)) were lower than those in the healthy controls (42.50 ng/mL [IQR, 31.25-59.17]) (P = 0.017). Patients with a NIHSS score ≤ 3 had higher apelin-13 levels than those with a NIHSS score > 3 (P = 0.048). At the 3-month follow-up, multivariate logistic regression analysis indicated an association between apelin-13 and death or major disability (OR 0.31; 95% CI 0.11-0.86; P = 0.024) and major disability (OR 0.32; 95% CI 0.11-0.90; P = 0.030). At the 1-year follow-up, the patients with high apelin-13 levels showed a lower incidence of stroke and combined events (Log-rank test P < 0.05). Our findings indicate that serum apelin-13 may be a potential prognostic biomarker for AIS.