Acute and chronic effect of dietary phosphorus restriction on protein expression in young rat renal proximal tubules

Abstract

Renal proximal tubules play a vital role in phosphorus (P) homeostasis. It is well known that dietary P restriction up-regulates the activities of 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1-OHase), an enzyme that is involved in activation of vitamin D and thereby maintaining P balance. However, the mechanism involved in such regulation is not known. In the present study, we aim to identify proteins that might be involved in the renal adaptation to dietary P restriction using a proteomic approach. Renal proximal tubules were harvested from young rats fed either normal P diet or low P diet (LPD) for 1 to 7 days. Western blotting analysis of 1-OHase and signaling proteins in insulin-like growth factor I axis indicated an increase in expression of these proteins upon dietary P restriction. Using two-dimensional electrophoresis, we found that LPD reduced the total number of protein species expressed in renal proximal tubules. Differentially expressed proteins were analyzed and located using the software Melanie III, and their identities were found using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Our results showed that beta-actin, gamma-actin, major urinary protein, phosphatidylinositol transfer protein beta isoform, and G1/S-specific cyclin D3 are up-regulated and nonspecific lipid transfer protein is down-regulated by LPD.

Differential proteomic analysis of proteins induced by glucocorticoids in cultured murine podocytes

“…We present for the first time, to our knowledge, a proteomic analysis of a glomerular cell type (podocyte), and a differential analysis of changes in protein expression in any cell type in response to glucocorticoids. A limited number of renal proteomic analyses have been performed to date, including proteomic profiles of urine proteins [26][27][28][29], renal cancer cells [30,31], isolated proximal tubules [32], and kidney tissue [29,33]. The only analysis we are aware of on the effect of steroids on the mammalian proteome is a study describing a genomic and proteomic analysis of prostate cancer cells in response to dihydroxytestosterone [34].…”

From Molecules to Mechanisms: Functional Proteomics and Its Application to Renal Tubule Physiology

“…One of the commonly used isolation methods is Percoll density gradient centrifugation, in which the renal cortical tissue is removed by dissection and digested with collagenase to release the cortical tubules, which are then resuspended in a 42.5-45% Percoll solution and centrifuged. Approximately 95% purity of proximal tubules can be obtained with this method (28,38,52,53,99,148,170,171).…”

Differential protein expression profile in the liver of pikeperch (Sander lucioperca) larvae fed with increasing levels of phospholipids

“…To date, only a limited number of studies have explored the dietary regulation of protein or gene expression (Cousins, 1999;Cheung et al, 2001;Schmid et al, 2003;Zeisel et al, 2005;De Roos et al, 2005), especially in fish species (Panserat et al, 2001;Martin et al, 2001;2003;Vilhelmsson et al, 2004;Brunt et al, 2008;Murray et al, 2009;Sissener et al, 2009). In addition to understand the metabolic processes involved in the adaptive responses, these studies help to improve the animal health status and growth performances.…”