ABSTRACT
Dysregulation of microRNAs (miRNAs) is involved in abnormal development and pathophysiology in the brain. Although miR-20b plays essential roles in various human diseases, its function in cerebral ischemic stroke remains unclear. A cell model of oxygen glucose deprivation/reoxygenation (OGD/R) and A rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) were constructed. qRT-PCR and western blot were used to evaluate the expression of miR-20b and TXNIP. Cell viability was detected by MTT assay, and cell apoptosis was evaluated by flow cytometry. Targetscan and Starbase were used to predict the potential targets of miR-20b. Luciferase reporter assay was applied to determine the interaction between miR-20b and TXNIP. Rescue experiments were conducted to confirm the functions of miR-20b/TXNIP axis in cerebral ischemic stroke. MiR-20b was significantly downregulated after I/R both in vitro and in vivo. Upregulation of miR-20b inhibited OGD/R-induced neurons apoptosis and attenuated ischemic brain injury in rat model. Bioinformatic prediction suggested that TXNIP might be a target of miR-20b, and luciferase reporter assay revealed that miR-20b negatively regulated TXNIP expression by directly binding to the 3’-UTR of TXNIP. Downregulation of TXNIP inhibited OGD/R-induced neurons apoptosis in vitro and ischemic brain injury in vivo. Rescue experiments indicated that downregulation of TXNIP effectively reversed the effect of miR-20b inhibitor in neurons apoptosis after OGD/R-treatment and ischemic brain injury in a mouse model after MCAO/R-treatment. Our study demonstrated that upregulation of miR-20b protected the brain from ischemic brain injury by targeting TXNIP, extending our understanding of miRNAs in cerebral ischemic stroke.
ABSTRACT
Dysregulation of microRNAs (miRNAs) is involved in abnormal development and pathophysiology in the brain. Although miR-20b plays essential roles in various human diseases, its function in cerebral ischemic stroke remains unclear. A cell model of oxygen glucose deprivation/reoxygenation (OGD/R) and A rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) were constructed. qRT-PCR and western blot were used to evaluate the expression of miR-20b and TXNIP. Cell viability was detected by MTT assay, and cell apoptosis was evaluated by flow cytometry. Targetscan and Starbase were used to predict the potential targets of miR-20b. Luciferase reporter assay was applied to determine the interaction between miR-20b and TXNIP. Rescue experiments were conducted to confirm the functions of miR-20b/TXNIP axis in cerebral ischemic stroke. MiR-20b was significantly downregulated after I/R both in vitro and in vivo. Upregulation of miR-20b inhibited OGD/R-induced neurons apoptosis and attenuated ischemic brain injury in rat model. Bioinformatic prediction suggested that TXNIP might be a target of miR-20b, and luciferase reporter assay revealed that miR-20b negatively regulated TXNIP expression by directly binding to the 3’-UTR of TXNIP. Downregulation of TXNIP inhibited OGD/R-induced neurons apoptosis in vitro and ischemic brain injury in vivo. Rescue experiments indicated that downregulation of TXNIP effectively reversed the effect of miR-20b inhibitor in neurons apoptosis after OGD/R-treatment and ischemic brain injury in a mouse model after MCAO/R-treatment. Our study demonstrated that upregulation of miR-20b protected the brain from ischemic brain injury by targeting TXNIP, extending our understanding of miRNAs in cerebral ischemic stroke.
ABSTRACT
AIM: To explore the way and the feasible time of olfactory ensheathing cells (OECs) transplanting to experimental autoimmune encephalomyelitis (EAE) rats, and to investigate the migration of OECs after transplanted to EAE and the possible mechanism of inducing the protective effect. METHODS: The Lewis rats, which were divided into MOG group and GPSCH group according to the induction by MOG~Igd and GPSCH separately, were used to made EAE model. The animals in MOG group were divided into 3 subsets: OECs blank group (MOG0 group, 4 rats );OECs transplantation by vena caudalis (MOG1 group, 7 rats);OECs transplantation by lateral cerebral ventricle (MOG2 group, 4 rats). The animals in GPSCH group were also divided into 2 subsets: OECs blank group (GPSCH0 group, 4 rats);OECs transplanted by vena caudalis (GPSCH1 group, 4 rats). OECs transplanted through different ways in peak incidence, then the rats were measured to determine whether the symptom was ameliorated. Two weeks after transplantion, the rats were killed and the methods of histofluorescence and histopathology (HE staining and Luxol fast blue staining) were used to examine the distribution of the labeled OECs in EAE rats' bodies and to explore whether there was some amelioration in histology. RESULTS: After OECs transplantation by vena caudalis or lateral cerebral ventricle, the rats' symptom improved. Compared to OECs blank groups, there was significant difference in clinical scores (F=18.470, P<0.01;t=-7.147, P<0.01). No significant difference between MOG1 group and MOG2 group was observed (P>0.05). The labeled OECs entered into the brain through the broken blood-brain-barrier after transplantation by vena caud-alis, the labeled OECs near the subpial area and around the lesions were found. OECs transplantation by the way of lateral cerebral ventricle showed great migration potential, the cells moved towards to the lesions extensively. No significant difference between OECs transplantation group and OECs blank group in histopathology (HE staining and LFB staining) was observed (P>0.05), and the same thing also happened between MOG1 group and MOG2 group (P>0.05). CONCLUSION: The transplantation of adult rats' OECs improves the EAE rats' symptom at some degree by the ways of vena caudalis or lateral cerebral ventricle.