Effects of Different Degrees of Carotid Artery Stenosis on the Expression of XIAP and Smac in the Ischemic Penumbra of Rats with Cerebral Ischemia-Reperfusion

Correlation analysis of serum miR-145 and miR-210 with carotid artery stenosis and their predictive value for cerebral ischemic events

OBJECTIVE

To analyze the significance of serum miR-145 and miR-210 expression levels in the diagnosis of carotid artery stenosis.

METHODS

During the same period, 55 healthy individuals who received physical examination in the same hospital were recruited as controls and assigned to a non-stenosis group. Among the included patients, there were 45 cases of mild stenosis, 14 cases of moderate stenosis, and 6 cases of severe stenosis after carotid color Doppler ultrasonography. The expression levels of miR-145 and miR-210 in serum were measured using real-time fluorescence quantitative polymerase chain reaction (qPCR) technology.

RESULTS

The expression levels of serum miR-145 and miR-210 in carotid artery stenosis group were significantly lower than those in non-stenosis group (p < 0.001). Multivariate Logistic regression analysis showed that smoking history, diabetes, hypertension and total cholesterol were positively correlated with the occurrence of carotid artery stenosis (p < 0.05). The expression levels of miR-145 and miR-210 were significantly negatively correlated with carotid artery stenosis (p < 0.001). In addition, patients with carotid artery stenosis and low expression levels of miR-145 and miR-210 had a greater risk of cerebral ischemia (p < 0.05). Cox regression analysis showed that the low expression of miR-145 and miR-210 were independent predictors of cerebral ischemic events. ROC analysis confirmed that miR-145 and miR-210 had good diagnostic efficacy in cerebral ischemia (p < 0.001).

CONCLUSION

The decreased expression of miR-145 and miR-210 in serum is closely related to the diagnostic significance of carotid artery stenosis, and may be used to predict the occurrence of cerebral ischemic events.

Effect of Butylphthalide Capsules on Smac and XIAP Expression in Rats after Ischemia Reperfusion

INTRODUCTION

Little is known about the protective effects of butylphthalide on cerebral ischemia-reperfusion injury. This study aims to investigate the impact on the second mitochondrial-derived activator of Caspases (Smac) and X-linked inhibitor of apoptosis protein (XIAP) expression in the ischemic semidark area using a rat model of carotid artery stenosis.

METHODS

Thirty Sprague-Dawley rats were randomly divided into the sham-operated group, carotid stenosis model controls, low-dose (20 mg/kg), medium-dose (40 mg/kg), and high-dose (80 mg/kg) butylphthalide groups. The neurological function was scored by the balance beam test (BBT). The morphological changes of brain tissue were detected by Hematoxylin-eosin (HE) staining, with apoptosis detected by Terminal Deoxynucleotidyl Transferase mediated dUTP Nick-End Labeling (TUNEL) staining. Smac and XIAP protein expression were detected by immunohistochemistry (IHC). The expressions of Smac and XIAP mRNA were detected by real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

HE showed that neuronal loss, nuclear consolidation, and vacuolar degeneration were significantly reduced in the medium and high-dose butylphthalide groups compared with the model controls. The BBT scores and apoptotic index were significantly lower in the medium and high doses of butylphthalide compared with the model controls. RT-qPCR and IHC showed that Smac, XIAP mRNA and protein expressions in the ischemic hemispheric region were significantly reduced in low, medium, and high doses of butylphthalide compared with the model controls (P < 0.05), showing some concentration effect.

CONCLUSIONS

Butylphthalide can significantly reduce Smac and XIAP mRNA and protein expression, inhibit neuronal apoptosis induced by ischemia-reperfusion injury in rats with carotid stenosis, and exert neuroprotective effects.

Mechanism of lncRNA SNHG16 in oxidative stress and inflammation in oxygen-glucose deprivation and reoxygenation-induced SK-N-SH cells

Cerebral ischemia-reperfusion injury imposes a clinical challenge for physicians in the wake of ischemic stroke. Meanwhile, recent evidence has come to light eliciting the neuroprotective function of SNHG16 in cerebrovascular diseases. Accordingly, the current study sought to analyze the regulatory mechanism of long non-coding RNA small nucleolar RNA host gene16 (SNHG16) in oxidative stress (OS) injury and cell inflammation. Firstly, models of oxygen-glucose deprivation and reoxygenation (OGD/R) were established in SK-N-SH cells. Cell proliferation and apoptosis were appraised using cell counting kit-8 and flow cytometry. Additionally, SNHG16, X-linked inhibitor of apoptosis protein (XIAP), microRNA (miR-421), reactive oxygen species (ROS), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor -α, interleukin (IL)-1β, and IL-10 expression patterns were determined. In addition, we determined and validated the subcellular localization of SNHG16 and the binding relationships between SNHG16 and miR-421, and miR-421 and XIAP. It was found that SNHG16 was poorly-expressed in OGD/R-treated cells. On the other hand, SNHG16 over-expression enhanced cell proliferation, inhibited apoptosis, and alleviated OS and cell inflammation. Furthermore, SNHG16 bound to miR-421 to facilitate the expression of XIAP. Up-regulation of miR-421 or down-regulation of XIAP could reverse the suppressive effects of SNHG16 on OS and cell inflammation. Collectively, our findings indicated that SNHG16 bound to miR-421 to facilitate XIAP expression, thus alleviating OS injury and inflammation in OGD/R-induced SK-N-SH cells.

Oxygen-Glucose Deprivation/Reperfusion-Induced Sirt3 Reduction Facilitated Neuronal Injuries in an Apoptosis-Dependent Manner During Prolonged Reperfusion

Cerebral ischemia is a major cause of morbidity and permanent disability. To date, no treatments for cerebral ischemia/reperfusion injury can be effectively administered beyond 4-6 h after the ischemic insult. Our study aimed to clarify the significance of Sirt3 during acute cerebral ischemia and explore Sirt3-targeted therapy for ischemic injuries. Upon establishing the oxygen-glucose deprivation/reperfusion (OGD/R) cell model, changes of Sirt3 protein levels and the effects of Sirt3 overexpression on primary hippocampal neurons were detected at indicated time points. Moreover, mitochondrial damage was observed in neurons upon OGD/R injury. The results showed that compared with the normoxia group, Sirt3 protein was significantly decreased in hippocampal neurons exposed to 1 h of OGD followed by 12 h of reperfusion. In addition, the reduction of Sirt3 protein levels contributed to OGD/R-induced neuronal injuries, a higher ratio of neuronal apoptosis, and extensive production of reactive oxygen species (ROS). However, all neuronal injuries were partly rescued by Sirt3 overexpression induced by lentivirus transfection. Mitochondrial morphologies were significantly impaired after OGD/R, but partly salvaged by Sirt3 overexpression. We further explored whether pharmacologically activating Sirt3 is protective for neurons, and found that treatment with honokiol (a Sirt3 agonist) after OGD exposure activated Sirt3 during reperfusion and significantly alleviated OGD/R-induced neuronal injuries. Because mitochondrial functions are essential for neuronal survival, the current results indicate that Sirt3 may be an efficient target to suppress ischemic injuries via maintenance of mitochondrial homeostasis. Our current findings shed light on a novel therapeutic strategy against subacute ischemic injuries.