Evaluation of CaSR rs1801725 and circulating miRNA-21-5p and miRNA-124-3p expression in chronic kidney disease-mineral and bone disorder patients

Abstract Background Chronic kidney disease-mineral and bone disorder (CKD-MBD) has been a prominent consequence of end-stage renal disease (ESRD), increasing cardiovascular risk and skeletal fragility. Emerging research shows that genetic and epigenetic variables play an important role in determining the development and progression of CKD-MBD. This study aimed to evaluate the potential role of calcium-sensing receptor (CaSR) rs1801725 polymorphism and the circulating microRNAs (miRNA-21-5p, miRNA-124-3p) as diagnostic biomarkers for CKD-MBD. This case-control study involved 100 Egyptian participants: 50 hemodialysis patients with CKD-MBD and 50 age- and sex-matched healthy controls. The CaSR rs1801725 polymorphism was genotyped using TaqMan ® allelic discrimination assays. Through the use of real-time quantitative reverse transcription PCR (qRT-PCR), the expression levels of serum miRNA-21-5p and miRNA-124-3p were measured. Results The GT and TT genotypes of CaSR rs1801725 were more frequent in CKD-MBD patients but didn’t reach statistical significance. The TT genotype was linked to higher parathyroid hormone (PTH) and bone specific alkaline phosphatase (b-ALP) levels and lower calcium. Both miRNA-21-5p and miRNA-124-3p were notably downregulated in CKD-MBD, with miRNA-21-5p inversely correlating with PTH. Receiver operating characteristic (ROC) analysis suggests both miRNAs, especially miRNA-21-5p, could serve as diagnostic biomarkers. Conclusions This study highlights the potential of serum miRNA-21-5p and miRNA-124-3p expression levels, as promising biomarkers for CKD-MBD but CaSR rs1801725 polymorphism not reach statistical significance as an independent diagnostic marker.