title: Adipocyte-derived factors impair insulin signaling in differentiated human vascular smooth muscle cells via the upregulation of miR-143.
abstract: Cardiovascular complications are common in patients with type 2 diabetes. Adipokines have been implicated in the induction of proliferative and pro-atherogenic alterations in human vascular smooth muscle cells (hVSMC). Other reports demonstrated the importance of the miRNA cluster miR-143/145 in the regulation of VSMC homeostasis and insulin sensitivity. Here we investigated whether the detrimental effects of adipokines on hVSMC function could be ascribed to alterations in miR-143/145 expression. The exposure of hVSMC to conditioned media (CM) from primary human subcutaneous adipocytes increased the expression of smooth muscle α-actin (SMA), and the miR-143/145 cluster, but markedly impaired the insulin-mediated phosphorylation of Akt and its substrate endothelial nitric oxide synthase (eNOS). Furthermore, CM promoted the phosphorylation of SMAD2 and p38, which have both been linked to miR-143/145 induction. Accordingly, the induction of miR-143/145 as well as the inhibition of insulin-mediated Akt- and eNOS-phosphorylation was prevented when hVSMC were treated with pharmacological inhibitors for Alk-4/5/7 and p38 before the addition of CM. The transfection of hVSMC with precursor miR-143, but not with precursor miR-145, resulted in impaired insulin-mediated phosphorylation of Akt and eNOS. This inhibition of insulin signaling by CM and miR-143 is associated with a reduction in the expression of the oxysterol-binding protein-related protein 8 (ORP8). Finally, the knock-down of ORP8 resulted in impaired insulin-mediated phosphorylation of Akt in hVSMC. Thus, the detrimental effects of adipocyte-derived conditioned media on insulin action in primary hVSMC can be ascribed to the Alk- and p38-dependent induction of miR-143 and subsequent downregulation of ORP8.
authors: Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany.
authors: Marcel
authors: M
authors: Blumensatt
authors: Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany.
authors: Nina
authors: N
authors: Wronkowitz
authors: Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany.
authors: Claudia
authors: C
authors: Wiza
authors: Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany.
authors: Andrea
authors: A
authors: Cramer
authors: Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany.
authors: Heidi
authors: H
authors: Mueller
authors: Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Martijn J
authors: MJ
authors: Rabelink
authors: Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Rob C
authors: RC
authors: Hoeben
authors: Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany.
authors: Juergen
authors: J
authors: Eckel
authors: Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany.
authors: Henrike
authors: H
authors: Sell
authors: Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany; Department of Endocrinology, Ghent University Hospital, Ghent, Belgium. Electronic address: margriet.ouwens@ddz.uni-duesseldorf.de.
authors: D Margriet
authors: DM
authors: Ouwens
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000328:Adult; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D034622:RNA Interference; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D051899:Smad2 Protein / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000098825:Oxysterol Binding Proteins
chemical_list: D017077:Culture Media, Conditioned; D007328:Insulin; C542359:MIRN143 microRNA, human; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D011987:Receptors, Steroid; D051899:Smad2 Protein; D000098825:Oxysterol Binding Proteins; D048051:p38 Mitogen-Activated Protein Kinases
keywords: Adipokines; Insulin signaling; Vascular smooth muscle cells; miRNA; p38