Sodium Hydrosulfide Post-conditioning Protects Hippocampal CA1 Neurons from Neuronal Cell Injury in the Rat Model of Transient Global Cerebral Ischemia Through Activation of Extracellular-regulated Kinases Signaling.

INTRODUCTION: The effect of hydrogen sulfide (H2S) on global cerebral ischemia remains partially understood. This study aimed to investigate the neuroprotective effect of sodium hydrosulfide (NaHS, a donor of H2S) post-conditioning and its underlying mechanism in a transient global cerebral ischemia (tGCI) model. MATERIALS & METHODS: The tGCI rat model was established by the four-vessel occlusion method. Wistar rats were randomly assigned into 6 groups: sham, tGCI, tGCI +NaHS, tGCI+vehicle, tGCI+U0126 and tGCI+U0126+NaHS groups. Neurons survival was assessed by Nissl staining and NeuN immunostaining. Levels of extracellular extracellular-regulated kinases (ERK)1/2 and p-ERK1/2 were determined by western blot and immunohistochemistry (IHC). Intraperitoneal injection of NaHS (24 µmol/kg) at 24 h post-tGCI attenuated tGCI-induced decrease of the survival and NeuN-positive neurons in the hippocampal CA1 subregion. RESULTS: Compared to the sham group, tGCI significantly up-regulated p-ERK1/2 protein at 26 and 48 h post-tGCI. NaHS post-conditioning further enhanced the phosphorylation of ERK1/2 at 26, 48 and 168 h post-tGCI. Nevertheless, U0126 (an inhibitor of MEK1/2) pre-treatment reduced the p-ERK1/2 level in both the tGCI+ U0126 group and the tGCI+ U0126+ NaHS group. IHC staining revealed that p-ERK1/2-positive cell could be observed in several hippocampal subregions of the rats receiving NaHS post-conditioning. Immunofluorescence staining showed that some neurons were double-stained with p-ERK1/2 and NeuN. Furthermore, U0126 pre-treatment significantly attenuated the protective effect of NaHS post-conditioning on the neurons survival and NeuNpositive neurons in CA1 subregion. CONCLUSION: These results suggested that NaHS post-conditioning can protect hippocampal CA1 neurons from tGCI-induced injury, at least partially, through activation of ERK1/2 signaling.

Metabolic syndrome and the short-term prognosis of acute ischemic stroke: a hospital-based retrospective study.

BACKGROUND: Metabolic syndrome (MetS) is an important risk factor for cerebral ischemic stroke, yet previous studies on the relationship between MetS or its components and acute cerebral infarction have been inconsistent. This study aims to evaluate the effects of MetS and its components on the short-term prognosis of patients with acute ischemic stroke. METHODS: Subjects with ischemic stroke of <7-day duration (530 cases) were enrolled. MetS was defined based on the modified criteria of the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. Demographic data, vascular risk factors, National Institutes of Health Stroke Scale score, the results of physical, laboratory and imaging examinations and clinical outcomes at 30 and 90 days were recorded. Using univariate analysis, we compared different baseline characteristics between patients with MetS and those without MetS. Further, we assessed MetS and its 5 components on the contribution to short-term prognosis of ischemic stroke with multiple logistic regression models after adjusting for age and sex. RESULTS: The prevalence of MetS among the patients with acute ischemic stroke in the study is 58.3%, with more in females (70.3%) than in males (49.7%, p < 0.001). As expected, among the MetS components, elevated waist circumference, elevated triglyceride, high fasting blood glucose and low high density lipoprotein cholesterol (HDL-C) were significantly more prevalent in patients with MetS than those without MetS (all p < 0.001). There was no correlation between MetS itself and the short-term prognosis of acute ischemic stroke. Only hyperglycemia in the serum was shown to have impact on poor functional outcomes in 30 and 90 days after the onset of stroke. CONCLUSIONS: The occurrence of MetS among patients with acute ischemic stroke in our study is 58.3%. MetS itself may not be predictive for the short-term prognosis of patients, while hyperglycemia is a significant predictor for poor functional outcomes in our study.