Downregulated microRNA-155 expression in peripheral blood mononuclear cells of type 2 diabetic patients is not correlated with increased inflammatory cytokine production

• Published in: Cytokine (Philadelphia, Pa.) Pa.), 2015-12, Vol.76 (2), p.403-408
• Main Authors: Mazloom, Hossein, Alizadeh, Samira, Pasalar, Parvin, Esfahani, Ensieh Nasli, Meshkani, Reza
• Format: Article
• Language: English
• Subjects: Adult; Case-Control Studies; Cytokine; Cytokines - biosynthesis; Cytokines - blood; Diabetes; Diabetes Mellitus, Type 2 - blood; Down-Regulation; Female; Humans; Inflammation; Inflammation Mediators - blood; Male; MicroRNAs - blood; MicroRNAs - genetics; Middle Aged; miR-155; Monocytes - metabolism; Peripheral blood mononuclear cells
• ISSN: 1043-4666; 1096-0023
• DOI: 10.1016/j.cyto.2015.07.007

•Aberrant expression of miR-155 has been linked to multiple inflammatory diseases.•Role of miR-155 in inflammatory responses of the diabetic patients remains unknown.•LPS upregulates miR-155 expression in PBMCs of both control and diabetic groups.•In basal state, miR-155 is downregulated in PBMCs of the diabetic patients.•miR-155 has not a role in increased cytokine production from PBMCs of diabetic patients. Objectives: The role of miR-155 in immune responses of PBMCs of type 2 diabetic (T2D) patients has not been studied. Design and methods: 20 Healthy and 20 T2D subjects were participated in the study. miR-155 expression in PBMCs of the subjects was measured using real-time PCR. The levels of secreted IL-6 and TNF-α cytokines were quantified using ELISA. Results: A downregulation of miR-155 expression was observed in untreated and LPS treated PBMCs of diabetic patients compared to controls. There was a significant upregulation of miR-155 after LPS treatment in PBMCs of both control and diabetic groups. In healthy subjects and in both untreated and LPS-treated conditions, miR-155 expression was negatively correlated with weight, waist circumference and body mass index. In diabetic group, there was a negative correlation between miR-155 expression and glucose levels only in LPS treated cells. Furthermore, systolic blood pressure was found to negatively correlate with miR-155 expression in untreated PBMCs of both healthy and diabetic subjects. The results also showed a significant correlation between miR-155 expression and TNF-α and IL-6 levels in LPS treated cells. Conclusions: Our data demonstrate that miR-155 expression is reduced in PBMCs of diabetic patients and this reduced expression does not seem to be involved in increased cytokine production from PBMCs of these patients.