Protein oxidation as a novel biomarker of bladder decompensation

Abstract

Objective: To measure the degree to which partial bladder outlet obstruction (PBOO) results in oxidative bladder damage, which subcellular components of the bladder are affected and whether these changes correlate with bladder function.

Materials and methods: In all, 32 rabbits were divided into four groups. Each group underwent PBOO for 1, 2, 4, and 8 weeks, respectively. Bladder tissue from each group was homogenized and separated into subcellular fractions via differential centrifugation. The carbonyl content within the subcellular fractions, including the nuclear, mitochondrial, and microsomal pellets, was then quantified by dot blot analysis.

Results: Total bladder oxidation increased with duration of obstruction across all subcellular fractions. The largest increase in total oxidation occurred between 4 and 8 weeks. Protein oxidation density in the nuclear and microsomal fractions both showed increases at 2 weeks obstruction, decreases at 4 weeks, and then large increases at 8 weeks. The increase in protein oxidation density between 4 and 8 weeks obstruction was most pronounced in the microsomal fraction.

Conclusions: Overall bladder protein oxidation increased with the duration of obstruction and increased at a greater rate during the transition to decompensation. Furthermore, the subcellular fraction that exhibited the most oxidation was the microsomal pellet. The amount of protein oxidation correlated with the functional changes in the bladder.