Vitamin D Levels Correlate with Metabolic Syndrome Criteria in Algerian Patients: The Ex-vivo Immunomodulatory Effect of α, 25 Dihydroxyvitamin D3.

Background: Metabolic syndrome (MetS) is a combination of metabolic disorders with increased risks for several diseases, such as cardiovascular diseases and diabetes. It is associated with the presence of various inflammatory molecules. Vitamin D plays an important role in the regulation of metabolism homeostasis.

Objective: The main goal of this work is to investigate vitamin D levels among Algerian MetS patients and its possible outcomes on key molecules of the immune response, as well, the immunomodulatory effects of its active metabolite.

Methods: We evaluated vitamin D status by the electrochemiluminescence method, Nitric Oxide (NO) levels by the Griess method and Matrix Metalloproteinases (MMPs) activities such as MMP-2 and MMP-9 by zymography in plasma of patients and healthy controls (HC). The immunomodulatory effects of the active metabolite of vitamin D (α-25 (OH)2D3) on the production of NO, IL-6, IL-10, TGF- β and s-CTLA-4 were assessed by Griess method and ELISA, in peripheral blood mononuclear cells (PBMCs) of Algerian MetS patients and HC. MMPs activities were also determined ex-vivo, while iNOS expression was assessed by immunofluorescence staining.

Results: Severe vitamin D deficiency was registered in Algerian MetS patients. The deficiency was found to be associated with an elevated in vivo NO production and high MMPs activity. Interestingly, α-25 (OH)2D3 declined the NO/iNOS system and IL-6 production, as well as MMPs activities. However, the ex-vivo production of IL-10, TGF-β increased in response to the treatment. We observed in the same way, the implication of s-CTLA-4 in MetS, which was markedly up-regulated with α-25 (OH)2D3.

Conclusion: Our report indicated the relationship between MetS factors and Vitamin D deficiency. The ex-vivo findings emphasize its impact on maintaining regulated immune balance.