Biomarker Analysis for Kidney Injury

Urine, blood and kidney samples were harvested at different time points as described above, and kept frozen at −80°C. BUN was assessed using a QuantiChrom Urea Assay kit (BioAssay Systems, DIUR-500) as described previously (Mattison et al., 2012 (link)). The urinary creatinine levels were measured using a colorimetric assay (R&D Systems, KGE005). Albuminuria was measured with a mouse albumin ELISA kit (Bethyl Laboratories, E99-134) and expressed as a ratio of the urinary creatinine. In addition, SDS-PAGE (4-12%) was carried out with 5 ml urine that was then stained with Coomassie Blue stain solution (Bio-Rad) to detect changes in high- and low-molecular mass urinary proteins as described previously (Das et al., 2016 (link)). For measuring the FGF-2 levels, blood was collected in tubes with EDTA, centrifuged at 4000 g for 5 min and stored immediately at −70°C. FGF-2 secreted by cells transduced with the rAd-FGF-2 vectors was measured with a human FGF basic/FGF-2/Quantikine ELISA Kit (R&D Systems, DFB50), as previously described.