Association of Expression of the Selenoprotein S Variants with Metabolic Syndrome in Subjects with Cardiovascular Disease

Background: selenoproteins S (SELS or VIMP) encodes a member of the selenoproteins family, characterized by a selenocysteine (Sec) residue at the active site. Studies suggest that this protein may regulate cytokine production, and thus play a key role in the control of the inflammatory response. Alternative splicing results in multiple transcript variants encoding different isoforms. Therefore, based on the innovative results concerning the operation of this gene, the present study is intended to assess this expression of VIMP in serum of cardiovascular subjects to achieve a probable metabolic syndrome (MetS) pathway.
Methods: The study sample consisted of 136 Iranian patients with cardiovascular disease (65 MetS-affected individuals, 71 MetS un-affected individuals) in the selengene study. Patients recruited sequentially during their angiography, myocardial revascularization or CABG in Isfahan, Iran. Expression of two variants of VIMP including VIMP I and VIMP II levels measured by using Real-Time PCR and SelS analyzed by ELIZA method.
Results: Subjects with MetS have higher serum levels of triglycerides, fasting blood glucose, and waist circumferences (P < 0.05). Family history of cardiovascular disease is higher in MetS patients compared to their MetS^- group (4.5% vs. 21.1%, P = 0.107). The level of VIMP II was lower in MetS⁺ compared to the MetS^- subjects (P <0.05) similarly the level of SELS is lower among MetS⁺ (P=0.02). We found no significant differences in quantitative expression of VIMPI in both groups. Whereas VIMP I has reverse correlation with FBS (r = -0.45, P= 0.009). We did not find any significant correlation between these variants with waist circumference, systolic and diastolic blood pressure and HDL–cholesterol. However SelS has negative correlation with WC(r = -0.171, P= 0.049) and positive correlation with HDL(r = 0.176, P= 0.046).
Conclusion: In the present assessment, it is evident that expression of VIMP varies highly among individuals with MetS as well as those without MetS. So regarding the functional role of this protein, it is possible to be deduced lower expression of it leads to higher secretion of unfolded protein to the cytosol and outside the cell which cannot play their exact role in different pathways.