title: Regulation of Vascular Smooth Muscle Cell Dysfunction Under Diabetic Conditions by miR-504.
abstract: Diabetes mellitus accelerates proatherogenic and proinflammatory phenotype of vascular smooth muscle cell (VSMC) associated with vascular complications. Evidence shows that microRNAs (miRNAs) play key roles in VSMC functions, but their role under diabetic conditions is unclear. We profiled miRNAs in VSMC from diabetic mice and examined their role in VSMC dysfunction.
  
  
  
  High throughput small RNA-sequencing identified 135 differentially expressed miRNAs in VSMC from type 2 diabetic db/db mice (db/dbVSMC) versus nondiabetic db/+ mice. Several of these miRNAs were known to regulate VSMC functions. We further focused on miR-504, because it was highly upregulated in db/dbVSMC, and its function in VSMC is unknown. miR-504 and its host gene Fgf13 were significantly increased in db/dbVSMC and in aortas from db/db mice. Bioinformatics analysis predicted that miR-504 targets including signaling adaptor Grb10 and transcription factor Egr2 could regulate growth factor signaling. We experimentally validated Grb10 and Egr2 as novel targets of miR-504. Overexpression of miR-504 in VSMC inhibited contractile genes and enhanced extracellular signal-regulated kinase 1/2 activation, proliferation, and migration. These effects were blocked by miR-504 inhibitors. Grb10 knockdown mimicked miR-504 functions and increased inflammatory genes. Egr2 knockdown-inhibited anti-inflammatory Socs1 and increased proinflammatory genes. Furthermore, high glucose and palmitic acid upregulated miR-504 and inflammatory genes, but downregulated Grb10.
  
  
  
  Diabetes mellitus misregulates several miRNAs including miR-504 that can promote VSMC dysfunction. Because changes in many of these miRNAs are sustained in diabetic VSMC even after in vitro culture, they may be involved in metabolic memory of vascular complications. Targeting such mechanisms could offer novel therapeutic strategies for diabetic complications.
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Marpadga A
authors.initials: MA
authors.lastname: Reddy
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Sadhan
authors.initials: S
authors.lastname: Das
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhuo
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Wen
authors.initials: W
authors.lastname: Jin
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
authors.forename: Linda
authors.initials: L
authors.lastname: Lanting
authors.affiliation: From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA. rnatarajan@coh.org mreddy@coh.org.
authors.forename: Rama
authors.initials: R
authors.lastname: Natarajan
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism / Q000473:pathology; D001018:Aortic Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D019295:Computational Biology; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D003925:Diabetic Angiopathies / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D051767:Early Growth Response Protein 2 / Q000235:genetics / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000378:metabolism; D051383:GRB10 Adaptor Protein / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation; D005947:Glucose / Q000494:pharmacology; D059014:High-Throughput Nucleotide Sequencing; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D019308:Palmitic Acid / Q000494:pharmacology; D010641:Phenotype; D034622:RNA Interference; D015398:Signal Transduction; D000071222:Suppressor of Cytokine Signaling 1 Protein / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D051767:Early Growth Response Protein 2; C497327:Egr2 protein, mouse; C495959:Grb10 protein, mouse; C000620513:MIRN504 microRNA, mouse; D035683:MicroRNAs; C491590:Socs1 protein, mouse; D000071222:Suppressor of Cytokine Signaling 1 Protein; D051383:GRB10 Adaptor Protein; D019308:Palmitic Acid; C108111:fibroblast growth factor 13; D005346:Fibroblast Growth Factors; D048049:Extracellular Signal-Regulated MAP Kinases; D005947:Glucose
keywords: aorta; atherosclerosis; diabetes complications; inflammation; microRNAs; vascular smooth muscle cells