Attenuation of CALCR protein expression in stone affected region of kidney biopsy tissue: Case presentation

Calcitonin is one of the most important hormones in human body which regulates calcium homeostasis. It binds with Calcitonin Receptor (CALCR) and reduces serum calcium level by inhibiting bone resorption and proximal renal reabsorption. Alteration in calcium homeostasis promotes diseases like osteoporosis, urolithiasis etc. An interesting finding of reduced CALCR protein expression in a urolithiasis patient motivated us to investigate its level in stone affected region of kidney biopsy tissue and hence in the present study, CALCR expression was checked in urolithiasis patients who had gone through open nephrolithotomy for stone removal. Basic and clinical parameters of the patients were recorded followed by analysis of stone composition, genotypic analysis and studying CALCR protein expression level in the kidney biopsy tissue samples (in the location of stone and an adjacent control area). CALCR protein expression was found to be attenuated in the stone affected region of kidney biopsy tissue as compared to adjacent control tissues (4-6 cm apart from the stone affected region) in all our studied samples (n=5). This case series represents an interesting finding as it is the first time report in the world, regarding expression of CALCR protein in kidney tissues of urolithiasis patients. Keywords: Urolithiasis; CALCR; Protein expression; SNP.