Proteome of melamine urinary bladder stones and implication for stone formation.
Melamine can cause urinary stones related to nephropathy of the kidney and hyperplasia or carcinoma of the bladder, but the mechanism of stone formation is not well understood. In this study, male rats were administered melamine for thirteen weeks to establish melamine bladder stone models and the stones were analysed by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS) and western blot, respectively, for the composition and proteome, and to explore the implication of proteins for stone formation. The results showed bladder stones were composed of predominant melamine and a few amount of proteins. The proteins had a wide range of molecular weights and 1051 proteins were identified. Gene Ontology (GO) classification of the identified proteins showed most proteins were from injured cells, involved in various metabolic processes and had binding functions. Of the identified proteins, there were a few inflammatory proteins and urinary proteins. Physicochemical characteristics of the identified proteins showed that 67.1% proteins' isoelectric points (pI) value was below 7.0, 91.1% proteins' grand average of hydropathicity (GRAVY) scores were below 0 and nearly half of the proteins were stable. Our data indicated proteins might play an important role in melamine bladder stone formation.
School of Public Health, Sun Yat-sen University, 74 Zhongshan Road 2, Guangzhou 510080, PR China.
Jian-dong
JD
Liu
Jian-jun
JJ
Liu
Jian-hui
JH
Yuan
Gong-hua
GH
Tao
De-sheng
DS
Wu
Xi-fei
XF
Yang
Lin-qing
LQ
Yang
Hai-yan
HY
Huang
Li
L
Zhou
Xin-yun
XY
Xu
Jun-jie
JJ
Hu
Zhi-xiong
ZX
Zhuang
D000818:Animals; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D020543:Proteome / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012117:Resins, Synthetic / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D053719:Tandem Mass Spectrometry; D014227:Triazines / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D001744:Urinary Bladder Calculi / Q000139:chemically induced* / Q000737:chemistry / Q000378:metabolism; D014961:X-Ray Diffraction
D020543:Proteome; D012117:Resins, Synthetic; D014227:Triazines; C011907:melamine