Neuroprotective mechanism of HIF-1α overexpression in the early stage of acute cerebral infarction in rats

Relationship between serum HIF-1α and VEGF levels and prognosis in patients with acute cerebral infarction combined with cerebral-cardiac syndrome

Objective

This research was conducted to discuss the recent prognosis of patients with acute cerebral infarction (ACI) combined with cerebral-cardiac syndrome (CCS).

Method

Eighty-seven patients with ACI were selected, which were divided into the ACI group (52 patients) and the CCS group (35 patients) according to whether the CCS was combined, and another 30 health controls were selected as the control group. Serum hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) levels of subjects in each group at the 1st day, the 3rd day, and the 7th day after admission were measured by enzyme-linked immunosorbent assay. After discharge for 30 days, the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) score were utilized to evaluate the prognosis of patients. The role of serum HIF-1α and VEGF levels in the prognosis of ACI combined with CCS patients was assessed by receiver operating characteristic curve and the binary logistic regression analysis.

Results

Higher serum HIF-1α and VEGF levels were observed in the CCS and ACI groups versus the control group, and the levels of which were even higher in the CCS group in comparison to the ACI group. According to the prognosis of the NIHSS score, fasting blood glucose (FBG), Acute Physiology and Chronic Health Evaluation II score, creatine kinase-MB (CK-MB), and HIF-1α and VEGF levels at the 7th day of admission were higher while Glasgow coma scale (GCS) score was lower in the poor prognosis group than those in the good prognosis group, and the area under the curve (AUC) of serum HIF-1α and VEGF levels was 0.895 (95% confident interval [CI], 0.786-1.000), and 0.855 (95% CI, 0.731-0.980). According to the prognosis of the mRS score, FBG, CK-MB, and HIF-1α and VEGF levels at the 7th day of admission were higher while GCS score was lower in the poor prognosis group than those in the good prognosis group, and the AUC of serum HIF-1α and VEGF levels was 0.850 (95% CI, 0.722-0.979) and 0.901 (95% CI, 0.798-1.000). The results of the binary logistic regression analysis revealed that HIF-1α and VEGF levels may be independent risk factors influencing the prognosis of ACI combined with CCS.

Conclusion

Serum HIF-1α and VEGF have a good predictive value for assessing the recent prognosis of patients with ACI combined with CCS, which could be independent risk factors influencing the prognosis of disease.

HIF‑1α in cerebral ischemia (Review)

Cerebral ischemic injury may lead to a series of serious brain diseases, death or different degrees of disability. Hypoxia-inducible factor-1α (HIF-1α) is an oxygen-sensitive transcription factor, which mediates the adaptive metabolic response to hypoxia and serves a key role in cerebral ischemia. HIF-1α is the main molecule that responds to hypoxia. HIF-1α serves an important role in the development of cerebral ischemia by participating in numerous processes, including metabolism, proliferation and angiogenesis. The present review focuses on the endogenous protective mechanism of cerebral ischemia and elaborates on the role of HIF-1α in cerebral ischemia. In addition, it focuses on cerebral ischemia interventions that act on the HIF-1α target, including biological factors, non-coding RNA, hypoxic-ischemic preconditioning and drugs, and expands upon the measures to strengthen the endogenous compensatory response to support HIF-1α as a therapeutic target, thus providing novel suggestions for the treatment of cerebral ischemia.

miR-124 Is Downregulated in Serum of Acute Cerebral Infarct Patients and Shows Diagnostic and Prognostic Value

Acute cerebral infarct (ACI) is a severe subtype of ischemic stroke. microRNAs (miRNAs) are implicated in the pathogenesis of ACI. This study investigated the expression pattern and clinical implication of miR-124 in ACI patients. Serum samples were collected from 108 healthy people and 108 ACI patients at 24 h, 48 h, and 72 h. Serum miR-124 expression was tested using qRT-PCR. The levels of interleukin (IL)-6, IL-8, and C-reactive protein (CRP) were detected using ELISA kits. The correlations between miR-124 expression and infarct classification, infarct size, risk factors, and inflammatory factors were analyzed. The diagnostic efficacy of miR-124 in ACI was analyzed by the ROC curve. ACI patients were assigned to the miR-124 high/low expression group and the incidence of poor prognosis was compared between the two groups. miR-124 expression was poorly expressed in the serum of ACI patients. The area under the ROC curve of miR-124 in the diagnosis of ACI was 0.9527, the specificity was 91.67%, and the sensitivity was 93.52%. miR-124 expression in ACI patients was not affected by infarct classification, infarct size, low-density lipoprotein level, and homocysteine level. miR-124 expression was negatively correlated with IL-6, IL-8, and CRP in ACI patients. Low expression of miR-124 was positively correlated with the poor prognosis of ACI. miR-124 was poorly expressed in the serum of ACI patients and served as a biomarker for the diagnosis and prognosis. This study shall confer a promising novel target for the diagnosis and treatment of ACI.

Expression and significance of S-100β, CysC and NF-κB in patients with acute cerebral infarction

The present study aimed to explore the expression and significance of S100 protein β (S100β), cystatin C (CysC), and nuclear factor kappa B (NF-κB) in patients with acute cerebral infarction (ACI). ACI patients (n=120) were selected as the experimental group at Xuzhou Central Hospital from August 2016 to August 2018. Ninety healthy subjects who underwent a physical examination at Xuzhou Central Hospital during the same period were selected as the control group. The expression levels of S-100β, CysC and NF-κB were compared between the two groups. Serum S-100β, CysC and NF-κB levels were compared between ACI patients with different degree of nervous functional defects, different infarct size and different prognosis. ROC curve analysis was used for the diagnosis of ACI by serum S-100β, CysC and NF-κB levels. Serum S-100β, CysC and NF-κB levels in the experimental group were higher than those in the control group (P<0.05). The levels of serum S-100β, CysC and NF-κB in patients with different neurological deficits were significantly different. The levels of serum S-100β, CysC and NF-κB in the severe and medium type infarction group were significantly higher than those in the mild type infarction group (both P<0.05). The levels of serum S-100β, CysC and NF-κB in the severe type infarction group were higher than those in the medium type infarction group (P<0.05). There were significant differences in serum S-100β, CysC and NF-κB levels in patients with different infarct sizes. The levels of serum S-100β, CysC and NF-κB in patients with large and medium size infarction were higher than those in the small size infarction group (both P<0.05). The levels of serum S-100β, CysC and NF-κB in patients with large size infarction were higher than those in patients with medium size infarction (P<0.05). Serum S-100β, CysC and NF-κB levels in patients of the worsening group were significantly higher than those in patients of the non-worsening group. The levels of S-100β, CysC, NF-κB in ACI patients were significantly higher than those in healthy subjects. Increased levels of S-100β, CysC and NF-κB can be used as ideal indexes for diagnosing cerebral infarction and studying the condition.

Willed‑movement training reduces middle cerebral artery occlusion‑induced motor deficits and improves angiogenesis and survival of cerebral endothelial cells via upregulating hypoxia‑inducible factor‑1α

Willed movement facilitates neurological rehabilitation in patients with stroke. Focal ischaemia is the hallmark of patients after stroke, though the detailed molecular mechanism by which willed movement affects neurological rehabilitation after stroke is not fully understood. The aim of the present study was to dissect the key factors of the hypoxia signaling pathway responsible for the willed movement‑improved rehabilitation. Sprague‑Dawley rats undergoing right middle cerebral artery occlusion (MCAO) surgery were randomly divided into four groups: MCAO alone, willed movement (WM), environmental modification (EM) and common rehabilitation (CR). The neurological behaviour score was assessed, and infarction areas were detected by TTC staining. In addition, angiogenesis‑associated genes (vascular epithelial growth factor, angiogenin‑1, matrix metalloproteinases‑2 and ‑9) and hypoxia inducible factor (HIF)‑1α expression was investigated in cells derived from MCAO, WM, EM and CR groups. Finally, the role of HIF‑1α using HIF‑1α knockdown in HUVECs under hypoxic conditions was evaluated. WM significantly improved neurological behaviour and rehabilitation by increasing the behaviour score and by decreasing the infarction area. In addition, CR, EM and WM raised the expression of angiogenesis‑associated genes and HIF‑1α, thereby promoting in vitro tube formation of primary endothelial cells. Knockdown of HIF‑1α in HUVECs restored the increased expression of angiogenesis‑associated genes to normal levels and inhibited in vitro tube formation of HUVECs. Willed movement most effectively improved the neurological rehabilitation of rats with focal ischaemia through upregulation of HIF‑1α. The present findings provide insight into willed movement‑facilitated rehabilitation and may help treat stroke‑triggered motor deficit and improve angiogenesis of cerebral endothelial cells.

LncRNA SNHG1 alleviates OGD induced injury in BMEC via miR-338/HIF-1α axis

BACKGROUND

Brain microvascular endothelial cell (BMEC) is an important therapeutic target for the inhibition of brain vascular dysfunction in ischemic stroke. Expression of long non-coding RNA SNHG1 is reportedly upregulated in BMEC after OGD. The present study aims to investigate the potential roles of SNHG1 in OGD-induced injury in BMEC.

METHODS

Mice primary brain microvascular endothelial cells (BMEC) were cultured under "normal" or "oxygen/glucose-deprived" (OGD) conditions. The expression of SNHG1 and miR-338 after OGD were examined by qPCR. shRNA against SNHG1 was used to knockdown SNHG1 in BMEC. MiR-338-3p mimic and inhibitor were used to change the expression of miR-338 in BMEC. The relationship between SNHG1 and miR-338, and the relationship between miR-338 and HIF-1α were clarified using RNA pull-down and luciferase reporter gene assays, respectively.

RESULTS

SNHG1 and miR-338 were upregulated in OGD induced BMEC. SNHG1 silence aggravated OGD-induced cell apoptosis by down-regulating Bcl-2, HIF-1α and VEGF-A, and upregulating caspase 3 activity and Bax. MiR-338 was upregulated in SNHG1-silenced BMEC. RNA pull-down assays showed that SNHG1 could be directly bound by miR-338. In addition, miR-338 overexpression reduced cell viability in OGD while miR-338 inhibition protected BMEC against OGD-induced injury. Furthermore, luciferase reporter assay showed that HIF-1α was a direct target of miR-338.

CONCLUSIONS

SNHG1 exerted protective effects against OGD induced injury via sponging miR-338, thus upregulating HIF-1α/VEGF-A in BMEC.

Signal Mechanism of the Protective Effect of Combined Preconditioning by Amtizole and Moderate Hypoxia

The content of regulatory proteins involved in adaptation to hypoxia and ischemia was studied in brain rat homogenate under conditions of normoxia and after bilateral ligation of the common carotid arteries. Preconditioning with amtizole in combination with moderate hypoxia increased the levels of HIF-1α, erythropoietin, vascular endothelial growth factor under conditions of normoxia. During experimental ischemia, combined preconditioning led to stabilization of the content of these regulatory proteins at the level of intact control and to a decrease in glycogen synthase-3β kinase activity. This pattern of changes in regulatory proteins was noted during the early and late periods of preconditioning.

Analysis of intestinal microbial communities of cerebral infarction and ischemia patients based on high throughput sequencing technology and glucose and lipid metabolism

Currently, cerebral infarction (CI) is the leading cause of disability and the second leading cause of mortality in China, seriously affecting patient quality of life. Ischemia (IS) is considered to be the early stage of CI. The present study aims to investigate the variation of intestinal microbial communities in patients with CI and IS using high throughput sequencing technology, and then analyze the results to identify a novel potential pathogenic mechanism of CI and IS. In total, 8 patients with CI, 2 patients with IS and 10 healthy volunteers as a control were selected. Throughput sequencing technology was used to analyze the character and microbial population of the gut. The abundance of Escherichia, Bacteroides, Megamonas, Parabacteroides, Akkermansia, Prevotella, Faecalibacterium, Dialister, Bifidobacterium and Ruminococcus was the significant difference in the intestinal microbial communities of the CI and IS patients compared with the healthy group. It was also observed that CI and IS were closely associated with internal glucose metabolism. The intestinal gut disturbance of CI patients may be one of the causes inducing CI by glucose metabolism and maybe considered as a potential method to predict the disease.