Vitamin D supplementation has no effect on matrix metalloproteinases-2, -9, and tissue inhibitor matrix metalloproteinase-1 in subjects with metabolic syndrome: A pilot study

Association between Circulating Levels of 25-Hydroxyvitamin D3 and Matrix Metalloproteinase-10 (MMP-10) in Patients with Type 2 Diabetes

Background: Matrix metalloproteinase-10 (MMP-10) levels increase progressively starting from early diabetic kidney disease (DKD) stages. Vitamin D3 (vitD3) deficit is associated with a higher risk of diabetic microangiopathy. Reduced MMP-10 expression has been observed after exposure to vitD3. Aim: to assess how vitD3 status is related to MMP-10 levels in patients with Type 2 diabetes (T2D). Methods: 256 patients with T2D were included in this cross-sectional study. Demographic, clinical and serum MMP-10 and 25-hydroxyvitamin D3 (25(OH)D3) levels were collected from each patient. The association between MMP-10 and (25(OH)D3) levels was assessed using a correlation analysis and fitting a multivariate linear regression model. Results: Serum MMP-10 levels were inversely correlated with circulating 25(OH)D3 (rho = −0.25; p < 0.001). In the subgroup analysis this correlation was significant in patients with DKD (rho = −0.28; p = 0.001) and in subjects with vitD3 deficit (rho = −0.24; p = 0.005). In the regression model adjusted for kidney function, body adiposity, smoking and vitD supplementation MMP-10 levels were 68.7 pg/mL lower in patients with 25(OH)D3 > 20 ng/mL, with respect to ≤20 ng/mL (p = 0.006). Conclusions: vitD3 repletion status is an independent predictor of MMP-10 levels in T2D patients. Perhaps, high 25(OH)D3 values should be targeted in these patients in order to prevent vascular complications.

Key metalloproteinase-mediated pathways in the kidney

Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinases (ADAMs) belong to the metzincin family of zinc-containing multidomain molecules, and can act as soluble or membrane-bound proteases. These enzymes inactivate or activate other soluble or membrane-expressed mediator molecules, which enables them to control developmental processes, tissue remodelling, inflammatory responses and proliferative signalling pathways. The dysregulation of MMPs and ADAMs has long been recognized in acute kidney injury and in chronic kidney disease, and genetic targeting of selected MMPs and ADAMs in different mouse models of kidney disease showed that they can have detrimental and protective roles. In particular, MMP-2, MMP-7, MMP-9, ADAM10 and ADAM17 have been shown to have a mainly profibrotic effect and might therefore represent therapeutic targets. Each of these proteases has been associated with a different profibrotic pathway that involves tissue remodelling, Wnt-β-catenin signalling, stem cell factor-c-kit signalling, IL-6 trans-signalling or epidermal growth factor receptor (EGFR) signalling. Broad-spectrum metalloproteinase inhibitors have been used to treat fibrotic kidney diseases experimentally but more targeted approaches have since been developed, including inhibitory antibodies, to avoid the toxic side effects initially observed with broad-spectrum inhibitors. These advances not only provide a solid foundation for additional preclinical studies but also encourage further translation into clinical research.

The effects of vitamin D supplementation on inflammatory biomarkers in patients with abnormal glucose homeostasis: A systematic review and meta-analysis of randomized controlled trials

FINDINGS

on the level of inflammatory cytokines following vitamin D supplementation among individuals with abnormal glucose homeostasis (AGH) are controversial. Therefore, the present study was conducted on AGH patients to assess the impact of vitamin D on inflammatory cytokines such as CRP, TNF-α and IL-6. A systematic search up to September 2020 was performed through PubMed and Scopus databases. All clinical studies which evaluated the effect of oral vitamin D supplementation on inflammation in patients with AGH were included. The random-effects model was applied to obtain pooled results. For dose-response analysis, we used a fractional polynomial model. Overall, 38 studies, with 46 effect sizes, were included in this study. Combining effect sizes, we found that vitamin D considerably decrease serum concentrations of CRP (weight mean difference (WMD): - 0.67 mg/l; 95%CI: - 0.92, - 0.43; P < 0.001), IL-6 (WMD: -1.93 pg/mL; 95%CI: -2.80, -1.07; P < 0.001) and TNF-α (WMD: -0.81 pg/mL; 95%CI: -1.59, -0.03; P = 0.04). In the dose-response analysis, we failed to find any correlation between dosage of supplements and inflammatory biomarkers concentrations. Summarizing earlier studies, we demonstrated that circulating concentrations of inflammatory cytokines such as CRP, TNF-α, and IL-6 might be decreased following vitamin D supplementation among individuals with AGH.