title: MicroRNAs miR-21a and miR-93 are down regulated in peripheral blood mononuclear cells (PBMCs) from patients with type 1 diabetes.
abstract: BACKGROUND
  It is well established that type 1 diabetes (T1D) is an autoimmune disease. Controversial data exists regarding the differential control of the immune system in T1D patients compared to unaffected individuals. MicroRNAs (miRNAs) are involved in the control of gene expression (by negative regulation of gene expression at post-transcriptional level, by mediating translational repression or degradation of the mRNA targets). Their potential role in T cell activation and autoimmunity is controversial.
  
  
  OBJECTIVE
  We investigated the expression profile of miR-21a and miR-93 in PMC samples of 20 T1D patients and 20 healthy controls by means of qPCR in different glucose concentrations (basal, 11 nM and 25 mM), and we analyzed the possible relationship of this expression pattern with autoimmunity.
  
  
  RESULTS
  MiR-21a was significantly underexpressed in T1D samples (media values expression 0.23 ± 0.05, p < 0.01) compared to controls (values less than 1 indicate a decrease in gene expression). When the PMCs were incubated with glucose 11 mM and 25 mM, miR-21a expression decreased in controls and increased in T1D samples (0.506 ± 0.05, p < 0.04). MiR-93 was underexpressed in T1D patients (0.331 ± 0.05, p < 0.02) compared to control samples. However, when the PBMCs were incubated with glucose, no changes were observed. No association with autoimmunity was observed.
  
  
  CONCLUSIONS
  We demonstrated that miRNAs have a differential expression in PBMCs from T1D patients compared to controls, suggesting that these miRNAs or others could be involved in T cell regulation.
authors.affiliation: Laboratorio de Genómica Nutricional, Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Chile.
authors.forename: Francisca
authors.initials: F
authors.lastname: Salas-Pérez
authors.forename: Ethel
authors.initials: E
authors.lastname: Codner
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Valencia
authors.forename: Carolina
authors.initials: C
authors.lastname: Pizarro
authors.forename: Elena
authors.initials: E
authors.lastname: Carrasco
authors.forename: Francisco
authors.initials: F
authors.lastname: Pérez-Bravo
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000235:genetics* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D035683:MicroRNAs / Q000097:blood / Q000235:genetics*
chemical_list: C524940:MIRN21 microRNA, human; C543350:MIRN93 microRNA, human; D035683:MicroRNAs; D005947:Glucose