Upper Zone of Growth Plate and Cartilage Matrix (UCMA) Levels in Patients with Chronic Kidney Disease

Abstract Chronic kidney disease (CKD) is an important health problem across the world affecting the adult population with an enormous social and economic burden. Calcium regulation is also affected in patients with CKD, and related to several disorders including vascular calcifications, mineral bone disorders, and cardiovascular diseases (CVD). Upper zone of growth plate and cartilage matrix (UCMA) is vitamin K-dependent protein (VKDP) and acts as a calcification inhibitor in the cardiovascular system. The molecular mechanism of UCMA action remains unclear in CKD. In the current study, we aimed to investigate serum total UCMA levels and its association with calcium metabolism parameters in CKD patients including hemodialysis (HD) patients. Thirty-seven patients with CKD stage 3-5, 41 HD patients, and 34 healthy individuals were enrolled in this cross-sectional study. Serum UCMA and calcification related protein levels (Matrix Gla Protein (MGP), Osteocalcin (OC), and Fetuin-A) were analyzed with enzyme-linked immunosorbent assay (ELISA). Calcium mineral disorder parameters (Serum Ca, P, iPTH) were quantified with routine techniques. We, for the first time, report the potential biomarker role of UCMA in CKD including HD. Serum total UCMA levels were significantly higher in patients with CKD including HD patients than the healthy controls. Also, serum UCMA levels showed negative correlations with serum calcium, and eGFR, while showed positive relationships with P, iPTH, MGP, OC. Increased total UCMA levels may have a role in the Ca metabolism disorder and related to the pathogenesis of Vascular Calcification in patients with CKD.

The relationship between matrix Gla protein gene polymorphism, serum osteocalcin levels and bone mineral density in postmenopausal Korean women / 대한산부인과학회지

OBJECTIVE: To investigate the relationship between the matrix Gla protein (MGP) gene polymorphism, serum osteocalcin levels and bone mineral density (BMD) in postmenopausal Korean women. METHODS: The MGP gene cytosine-adenine (CA) polymorphism was analyzed by polyacrylamide-urea gel eletrophoresis, genescan and DNA sequencing in 267 postmenopausal Korean women. Serum osteocalcin, bone alkaline phosphatase (BAP), and CrossLaps (CTX) were measured by immunoassay, and enzyme linked immunosorbent assay respectively. BMD at the lumbar spine and proximal femur was determined by dual energy X-ray absorptiometry. RESULTS: Six MGP alleles were observed with product sizes ranging between 204-214 bp, and their distributions were as follows: 210 bp 57.5%, 221 bp 27.9%, 206 bp 13.3% etc. There were no significant differences in BMD of the lumbar spine and proximal femur across the MGP genotypes. No significant differences in the distribution of MGP genotypes among normal, osteopenic, and osteoporotic postmenopausal women were observed. Serum osteocalcin level was significantly higher in women who did not 210 bp MGP (CA) allele than in women carrying at least one copy of this allele, while no significant differences in serum BAP and CTX levels were noted among MGP genotypes. CONCLUSION: The MGP gene (CA) polymorphism does not affect BMD but serum osteocalcin levels in postmenopausal Korean women.