LncRNA SNHG12 ameliorates brain microvascular endothelial cell injury by targeting miR-199a.

Long non-coding RNAs regulate brain microvascular endothelial cell death, the inflammatory response and angiogenesis during and after ischemia/reperfusion and oxygen-glucose deprivation/reoxygenation (OGD/R) insults. The long non-coding RNA, SNHG12, is upregulated after ischemia/reperfusion and OGD/R in microvascular endothelial cells of the mouse brain. However, its role in ischemic stroke has not been studied. We hypothesized that SNHG12 positively regulates ischemic stroke, and therefore we investigated its mechanism of action. We established an OGD/R mouse cell model to mimic ischemic stroke by exposing brain microvascular endothelial cells to OGD for 0, 2, 4, 8, 16 or 24 hours and reoxygenation for 4 hours. Quantitative real-time polymerase chain reaction showed that SNHG12 levels in brain microvascular endothelial cells increased with respect to OGD exposure time. Brain microvascular endothelial cells were transfected with pcDNA-control, pcDNA-SNHG12, si-control, or si-SNHG12. After exposure to OGD for 16 hours, these cells were then analyzed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, trypan blue exclusion, western blot, and capillary-like tube formation assays. Overexpression of SNHG12 inhibited brain microvascular endothelial cell death and the inflammatory response but promoted angiogenesis after OGD/R, while SNHG12 knockdown had the opposite effects. miR-199a was identified as a target of SNHG12, and SNHG12 overexpression reversed the effect of miR-199a on brain microvascular endothelial cell death, the inflammatory response, and angiogenesis. These findings suggest that SNHG12 suppresses endothelial cell injury induced by OGD/R by targeting miR-199a.

Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells.

OBJECTIVE: To investigate the protective effects of hydrogen peroxide preconditioning (HPP) on the pheochromocytoma (PC12) cells treated with 1-methyl-4-phenylpyridinium (MPP(+)) and to explore the potential mechanisms. METHODS: The viability and apoptosis of PC12 cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6'-diamidino-2-phenylindole (DAPI) staining, respectively. The expressions of 14-3-3 protein and phosphorylated p38 mitogen-activated protein kinase (MAPK) were determined by Western blot. Enzyme-linked immunosorbent assay (ELISA) was used to measure the activity of extracellular signal-regulated protein kinase 1/2 (ERK1/2). RESULTS: The cell viability decreased and the number of apoptotic cells increased dramatically in MPP(+) group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP(+)-treated PC12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC12 cells induced by HPP. CONCLUSION: HPP protects PC12 cells against MPP(+) toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

Correlation between angiotensinogen gene and primary hypertension with cerebral infarction in the Li nationality of China.

OBJECTIVE: To investigate the relationship of four single nucleotide polymorphism (SNP) haplotypes in the angiotensinogen (AGT) gene to the primary hypertension with or without cerebral infarction in the Li nationality of Hainan, China. METHODS: Total 300 subjects were allocated into three different groups: Group 1, 100 patients who have primary hypertension; Group 2, 100 patients who have primary hypertension with cerebral infarction; and control group, 100 healthy individuals. The genotypes of all subjects were determined by PCR-sequencing to analyze the four polymorphisms at position -152 (G-A), -20 (A-C), -18 (C-T), and -6 (A-G) in the promoter region of AGT. RESULTS: The frequencies of CT genotype of AGT-18 and T allele in Group 1 (P = 0.003, P = 0.004) and Group 2 (P = 0.002, P = 0.002) were both significantly higher than in healthy controls. The frequency of G allele of AGT-6 was significantly higher in Group 2 than in the control group (P = 0.016), while there is no significant difference between Group 1 and the control. Haplotype analysis revealed that H6 haplotype frequency which included -20C and -6G was significantly increased in Group 2 (P = 0.003) compared with the control group, while H5 haplotype frequency which included -20C and -18T was significantly increased in Group 1 (P = 0.006) versus the control. CONCLUSION: The -20 (A-C) and -18 (C-T) of the AGT may play an important role in pathogenesis of primary hypertension; and -20 (A-C), -18 (C-T), and -6 (A-G) may be the genetic risk factors for the onset of primary hypertension with cerebral infarction in the Li nationality of Hainan, China.