Spermatogenesis is a process where an important contribution of genes involved in folate-mediated one-carbon metabolism is observed. The aim of the present study was to investigate the association between male infertility and the MTHFR (677C > T; 1298A > C), MTR (2756A > G) and MTRR (66A > G) polymorphisms in a Polish population. No significant differences in genotype or allele frequencies were detected between the groups of 284 infertile men and of 352 fertile controls. These results demonstrate that common polymorphisms in folate pathway genes are not major risk factors for non-obstructive male infertility in the Polish population.

Membrane monocarboxylate transporter 1 (SLC16A1/MCT1) plays an important role in hepatocyte homeostasis, as well as drug handling. However, there is no available information about the impact of liver pathology on the transporter levels and function. The study was aimed to quantify SLC16A1 mRNA (qRT-PCR) and MCT1 protein abundance (liquid chromatography–tandem mass spectrometry (LC¬¬–MS/MS)) in the livers of patients diagnosed, according to the standard clinical criteria, with hepatitis C, primary biliary cirrhosis, primary sclerosing hepatitis, alcoholic liver disease (ALD), and autoimmune hepatitis. The stage of liver dysfunction was classified according to Child–Pugh score. Downregulation of SLC16A1/MCT1 levels was observed in all liver pathology states, significantly for ALD. The progression of liver dysfunction, from Child–Pugh class A to C, involved the gradual decline in SLC16A1 mRNA and MCT1 protein abundance, reaching a clinically significant decrease in class C livers. Reduced levels of MCT1 were associated with significant intracellular lactate accumulation. The MCT1 transcript and protein did not demonstrate significant correlations regardless of the liver pathology analyzed, as well as the disease stage, suggesting posttranscriptional regulation, and several microRNAs were found as potential regulators of MCT1 abundance. MCT1 membrane immunolocalization without cytoplasmic retention was observed in all studied liver pathologies. Overall, the study demonstrates that SLC16A1/MCT1 is involved in liver pathology, especially in ALD.

Recent efforts have been made to identify genetic markers of CYP3A4 enzymatic activity within genes encoding for regulatory elements. The aim of the current study was to investigate the impact of polymorphism of PPARA and POR genes on tacrolimus (TAC) dose-adjusted trough concentration and risk of new-onset diabetes after transplantation (NODAT). A total of 241 White kidney transplant patients were genotyped for three functional single nucleotide polymorphisms: rs1057868 (*28) in POR, rs4253728:G>A, and rs4823613:A>G in PPARA. No significant genotype-dependent differences in TAC dose-adjusted trough concentration were observed for either POR or PPARA variants. No significant differences in the incidence of NODAT were observed between patients stratified by PPARA and POR genotypes. The frequency of NODAT among PPARA rs4253728 AA homozygotes (42%) was higher compared with heterozygotes (22%) and GG homozygotes (19%), but the difference was not significant. Testing TAC-medicated renal transplant recipients for POR and PPARA variants seems to have limited clinical application.