TY - JOUR
T1 - Acute and chronic effect of dietary phosphorus restriction on protein expression in young rat renal proximal tubules
AU - Cheung, Pik Yuen
AU - Lai, Wan Ping
AU - Lau, Hoi Yan
AU - Lo, Chun Lap Samuel
AU - Wong, Man Sau
PY - 2002/9/1
Y1 - 2002/9/1
N2 - 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 D3-1 α-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 β-actin, γ-actin, major urinary protein, phosphatidylinositol transfer protein β isoform, and G1/S-specific cyclin D3 are up-regulated and nonspecific lipid transfer protein is down-regulated by LPD.
AB - 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 D3-1 α-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 β-actin, γ-actin, major urinary protein, phosphatidylinositol transfer protein β isoform, and G1/S-specific cyclin D3 are up-regulated and nonspecific lipid transfer protein is down-regulated by LPD.
KW - Insulin-like growth facor I axis
KW - Phosphorus restriction
KW - Rat renal proximal tubules
KW - Two-dimensional gel electrophoresis
UR - http://www.scopus.com/inward/record.url?scp=0036745418&partnerID=8YFLogxK
U2 - 10.1002/1615-9861(200209)2:9<1211::AID-PROT1211>3.0.CO;2-#
DO - 10.1002/1615-9861(200209)2:9<1211::AID-PROT1211>3.0.CO;2-#
M3 - Journal article
C2 - 12362338
SN - 1615-9853
VL - 2
SP - 1211
EP - 1219
JO - Proteomics
JF - Proteomics
IS - 9
ER -