Diagnosis of kidney diseases has recently become more comprehensive and accurate by using new renal markers. Despite the fact that creatinine and cystatin c have been sufficient in determining kidney function, they did not indicate the exact site of the damage and they were often insufficient in predicting the course of the disease. Aim of the study was to evaluate the potential correlations and differences in levels of six factors related to kidney function and injury: kidney injury molecule-1 (KIM-1), ncalbindin (CALB), glutathione S-transferase Pi (GST-Pi), calbindin and monocyte chemoattractant protein-1 (MCP-1), between renal patients with diabetic nephropathy (DM), congenital defects (CD) of the kidney and glomerulonephritis (GN). Study involved 75 patients: 49 with diabetic nephropathy, 12 with congenital defects and 14 with glomerulonephritis. Levels of renalase was measured using immunoenzymatic tests. Levels of other markers: calbindin, glutathione-S-transferase (GST-pi), interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1) and monocyte chemoattractant protein-1 (MCP-1), were analyzed using Kidney Toxicity-1 Panel and BioPlex system, designed for analyses in urine and optimized by us for serum.From all analyzed markers, only levels of KIM-1 differed significantly between any subgroups, and that was for CD and DM. Renalase correlated significantly negatively with creatinine and positively with all other markers, apart from MCP-1. Obtained results indicate, that serum renalase, KIM-1, calbindin and GST-pi are related to kidney function, with KIM-1 being the most exact, while MCP-1 levels are unrelated to creatinine and glucose levels, does not differ between patients with diabetic nephropathy and other subgroups, and therefore seem to be independent of diabetes. Also, serum-optimized Kidney Toxicity Panel 1 kit for determination of selected markers gave results similar to previous ones and therefore the method can be valuable in determination of analyzed factors.

The most prevalent Ca2+-buffer proteins (CaBPs: parvalbumin—PV; calbindin—CaB; calretinin—CaR) are widely expressed by various neurons throughout the brain, including the retinal ganglion cells (RGCs). Even though their retinal expression has been extensively studied, a coherent assessment of topographical variations is missing. To examine this, we performed immunohistochemistry (IHC) in the mouse retina. We found variability in the expression levels and cell numbers for CaR, with stronger and more numerous labels in the dorso-central area. CaBP+ cells contributed to RGCs with all soma sizes, indicating heterogeneity. We separated 4-9 RGC clusters in each area based on expression levels and soma sizes. Besides the overall high variety in cluster number and size, the peripheral half of the temporal retina showed the greatest cluster number, indicating a better separation of RGC subtypes there. Multiple labels showed that 39% of the RGCs showed positivity for a single CaBP, 30% expressed two CaBPs, 25% showed no CaBP expression and 6% expressed all three proteins. Finally, we observed an inverse relation between CaB and CaR expression levels in CaB/CaR dually- and CaB/CaR/PV triple labeled RGCs, suggesting a mutual complementary function.