Pin1 and secondary hyperparathyroidism of chronic kidney disease: Gene polymorphisms and protein levels

Abstract

Background: Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1) is a key regulator of PTH mRNA stability. Secondary hyperparathyroidism (SHPT), which is characterized by elevated serum PTH levels, is a common complication of CKD. We investigated the possible associations between CKD with SHPT (CKD SHPT) and single-nucleotide polymorphisms of the Pin1 gene and compared the levels of the Pin1 protein in the CKD SHPT patients with those of the controls. Methods: The study group included 251 CKD SHPT patients and 61 controls. One putative functional SNP (single nucleotide polymorphism) in the Pin1 promoter (rs2233679C>T: c.−667C>T) is the main object. Genotyping was performed on purified DNA using polymerase chain reaction-restriction (PCR) and restriction fragment length polymorphisms (RFLP). The levels of Pin1 were measured in serum using an enzyme-linked immunosorbent assay. Results: Genotyping showed that CT+TT in the Pin1 promoter was significantly more common in the CKD SHPT group than in the control group (p