P0421STUDY OF DIFFERENT EXPRESSION PROFILES OF “TRANSIENT RECEPTOR POTENTIAL ION CHANNEL (TRPC) GENE FAMILY” IN PATIENTS UNDERGOING RENAL BIOPSY WITH CLINICAL SUSPECTED GLOMERULONEPHRITIS

Abstract Background and Aims The transient receptor potential ion channels (TRPC) are non-selective Ca+ 2 permeable cation channels and are widely expressed in the tissues of vertebrates. They become active in response to signal transduction pathways associated with phospholipase C stimulation. TRPC6 is expressed in podocytes and is a component of the slit diaphragm. In genetic and acquired glomerular kidney diseases, TRPC6 overactivation causes podocyte damage by pathological Ca+ 2 entry. TRPC1, TRPC2, TRPC4, and TRPC5 interact with a protein called stromal-interacting molecule 1 (STIM 1), which is susceptible to intracellular calcium storage content. As a result of binding with this protein, TRPC channels bind to calcium-releasing zone in endosomes. The aim of the study was to investigate different expression profiles of TRPC family members in renal biopsy specimens in patients with clinically considered glomerulonephritis. Method This study was conducted with 108 patients admitted to Ege University Faculty of Medicine Nephrology Clinic who underwent a kidney biopsy with a preliminary diagnosis of glomerulonephritis and 37 patients who underwent a nephrectomy in urology clinic with a diagnosis of primary kidney tumour as a control case. PKD2, NPHS2, TRPC1, TRPC3, TRPC6, STIM-1 and Orai-1 mRNA levels were studied in the biopsy samples. Results When we compared the patient and the control group, the gender distribution of both groups was similar. The frequency of diabetes and hypertension was similar. The control group was statistically significantly older and glomerular filtration rates were higher than the patient group. In pathological examination, glomerulonephritis (57.5%) was diagnosed in the majority of patients. The most common etiologic factors were membranous nephropathy 23.1%, IgA nephropathy 13%, Amyloidosis 11.2%, focal segmental glomerulosclerosis 7.1%, proliferative glomerulonephritis 4.6%, minimal change disease 2.8% and membranoproliferative glomerulonephritis was 1.9%. 7.4% of the patients were diagnosed with diabetic nephropathy by renal biopsy. When we compared the TRPC expression profiles of the patient and the control group, the TRPC1, TRPC6, PKD2, NPHS2, STIM-1 and ORAi-1 mRNA levels of the patient group were statistically significantly higher than those of the control group (Figure). In contrast, TRPC3 mRNA levels were significantly lower in the patient group compared to the control group. When we performed subgroup analysis, the TR