Fas/Fas ligand system was shown to be related to insulin resistance and type 2 diabetes mellitus (T2DM). However, the role of soluble Fas ligand (sFasL) in functioning of immune cells in type 2 diabetes mellitus (T2DM) has not been studied yet. The aim of the present study was to determine in vitro effects of sFasL on neutrophil activation and apoptosis. We demonstrate here that sFasL exhibited proinflammatory effect and induced mRNA levels of caspase-1, NF-κB, IL-1β and CD18 expression. At the same time, sFasL induced reactive oxygen species (ROS) production. Activation of caspase-1 activity abolished sFasL-dependent apoptosis, and suppressed Fas expression and mRNA levels of caspase-3 in neutrophils from T2DM patients. Collectively, our findings identify a novel proinflammatory role of sFasL in T2DM neutrophils that is dependent of caspase activity. Thus, sFasL enhances inflammatory response of neutrophils from T2DM patients without increasing apoptosis suggesting its triggering role in T2DM inflammation.

PD-1/PD-L1 axis plays an important role in maintaining homeostasis and prevention from autoimmunity; however, in the tumor microenvironment, PD-1/PD-L1 interaction is responsible for the evasion of immune surveillance by tumor cells. We therefore hypothesized that single nucleotide polymorphisms (SNPs) in genes encoding PD-1 and PD-L1 molecules are associated with the development and outcome of renal cell carcinoma (RCC). Here we genotyped nine polymorphisms: five of PDCD1: rs36084323G>A, rs11568821G>A, rs2227981C>T, rs10204525G>A, rs7421861T>C and four of PD-L1: rs822335C>T, rs4143815G>C, rs4742098A>G, rs10815225G>C in 237 RCC patients (including 208 with clear cell RCC (ccRCC)) and 256 controls, with application of allelic discrimination method with use of TaqMan Assays. Interestingly, we found the SNP-SNP interaction between rs10815225 and rs7421861 polymorphisms associated with ccRCC risk. The rs7421861 TC genotype decreased the risk of ccRCC development compared to TT and CC genotypes in the group of rs10815225 GC + CC individuals (OR = 0.21, CI95% = 0.08; 0.54). While possessing of rs10815225 GC or CC genotype increased susceptibility to ccRCC when compared to rs10815225 GG genotype in individuals with rs7421861 TT or CC genotype (OR = 2.40, CI95% = 1.25; 4.61). In conclusion, genetic variants in PDCD1 and PD-L1 genes, especially taken together as SNP-SNP interactions, can be considered to be ccRCC risk factors.

Decreased UCP2 gene expression in mononuclear cells from obese and diabetic patients might contribute to the immunological abnormalities in these metabolic disorders and suggests its role as a candidate gene in future studies of obesity and diabetes.