MicroRNA-181c provides neuroprotection in an intracerebral hemorrhage model

摘要

Apoptosis is an important factor during the early stage of intracerebral hemorrhage.MiR-181 c plays a key regulatory role in apoptosis.However,whether miR-181 c is involved in apoptosis of prophase cells after intracerebral hemorrhage remains unclear.Therefore,in vitro and in vivo experiments were conducted to test this hypothesis.In vivo experiments:collagenase type VII was injected into the basal ganglia of adult Sprague-Dawley rats to establish an intracerebral hemorrhage model.MiR-181 c mimic or inhibitor was injected in situ 4 hours after intracerebral hemorrhage.Neurological functional defects(neurological severity scores)were assessed 1,7,and 14 days after model establishment.Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and western blot assay were conducted 14 days after model establishment.In vitro experiments:PC12 cells were cultured under oxygen-glucose deprivation,and hemins were added to simulate intracerebral hemorrhage in vitro.MiR-181 c mimic or inhibitor was added to regulate miR-181 c expression.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay,luciferase reporter system,and western blot assay were performed.Experimental results revealed differences in miR-181 c expression in brain tissues of both patients and rats with cerebral hemorrhage.In addition,in vitro experiments found that miR-181 c overexpression could upregulate the Bcl-2/Bax ratio to inhibit apoptosis,while inhibition of miR-181 c expression could reduce the Bcl-2/Bax ratio and aggravate apoptosis of cells.Regulation of apoptosis occurred through the phosphoinositide 3 kinase(PI3 K)/Akt pathway by targeting of phosphatase and tensin homolog deleted on chromosome ten(PTEN).Higher miR-181 c overexpression correlated with lower neurological severity scores,indicating better recovery of neurological function.In conclusion,miR-181 c affects the prognosis of intracerebral hemorrhage by regulating apoptosis,and these effects might be directly mediated and regulated by targeting of the PTENPI3 K/Akt pathway and Bcl-2/Bax ratio.Furthermore,these results indicated that miR-181 c played a neuroprotective role in intracerebral hemorrhage by regulating apoptosis of nerve cells,thus providing a potential target for the prevention and treatment of intracerebral hemorrhage.Testing of human serum was authorized by the Ethics Committee of China Medical University(No.2012-38-1)on February 20,2012.The protocol was registered with the Chinese Clinical Trial Registry(Registration No.ChiCTR-COC-17013559).The animal study was approved by the Institutional Animal Care and Use Committee of China Medical University(approval No.2017008)on March 8,2017.