title: Nestin protects mouse podocytes against high glucose-induced apoptosis by a Cdk5-dependent mechanism.
abstract: Podocyte apoptosis contributes to the pathogenesis of diabetic nephropathy (DN). However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis remain poorly understood. Recent findings indicate that the disruption of the cytoskeleton is related to the podocyte apoptosis. In the present study, we investigated the involvement of nestin, an important cytoskeleton-associated class VI intermediate filament (IF) protein, in the high glucose (HG)-induced podocyte apoptosis. Our data showed that HG decreased the expression level of nestin, either mRNA or protein, in a time-dependent manner in cultured podocytes. Also, through knockdown of nestin expression by miRNA interference, the HG-induced podocyte apoptotic rate was significantly increased. The expression of cleaved caspase-3 was also markedly elevated. Considering that nestin is a substrate of cyclin-dependent kinase 5 (Cdk5), we further assessed the expression of Cdk5 in HG-treated podocytes. The results showed that HG stimulation increased the protein and mRNA expression of Cdk5 in a time-dependent manner in cultured mouse podocytes. The protein activator of Cdk5, p35, was also increased in a time-dependent manner by HG stimulation, and downregulation of Cdk5 by miRNA interference attenuated the nestin reduction in HG-treated podocytes; the HG-induced podocyte apoptosis, the increased cleaved caspase-3 expression and the Bax/Bcl-2 ratio were all effectively attenuated. These data suggested that nestin, which is dependent on Cdk5 regulation, plays a cytoprotective role in HG-induced podocyte apoptosis.
authors.affiliation: Department of Pathology, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Hao
authors.forename: Shuxia
authors.initials: S
authors.lastname: Liu
authors.forename: Qingjuan
authors.initials: Q
authors.lastname: Liu
authors.forename: Song
authors.initials: S
authors.lastname: Zhao
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Shi
authors.forename: Huijun
authors.initials: H
authors.lastname: Duan
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism; D051360:Cyclin-Dependent Kinase 5 / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D055785:Gene Knockdown Techniques; D005947:Glucose / Q000009:adverse effects*; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D064231:Nestin; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism; D050199:Podocytes / Q000187:drug effects* / Q000473:pathology; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: C492236:Cdk5r1 protein, mouse; D003470:Culture Media; D007381:Intermediate Filament Proteins; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D012333:RNA, Messenger; D010770:Phosphotransferases; D051360:Cyclin-Dependent Kinase 5; C495906:Cdk5 protein, mouse; C505409:Casp3 protein, mouse; D053148:Caspase 3; D005947:Glucose