Limits...
Hydration status affects osteopontin expression in the rat kidney

View Article: PubMed Central - PubMed

ABSTRACT

Osteopontin (OPN) is a secretory protein that plays an important role in urinary stone formation. Hydration status is associated with the development of urolithiasis. This study was conducted to examine the effects of dehydration and hydration on OPN expression in the rat kidney. Animals were divided into three groups, control, dehydrated, and hydrated. Kidney tissues were processed for light and electron microscope immunocytochemistry, in situ hybridization, and immunoblot analysis. Dehydration induced a significant increase in OPN protein expression, whereas increased fluid intake induced a decrease in protein expression. Under control conditions, OPN protein and mRNA expression were only detected in the descending thin limb (DTL). Dehydration induced increased expression in the DTL and the development of detectable expression in the thick ascending limb (TAL). In contrast, OPN expression levels declined to less than the controls in the DTL after hydration, while no expression of either protein or mRNA was detectable in the TAL. Immunoelectron microscopy demonstrated that hydration status altered tubular ultrastructure and intracellular OPN expression in the Golgi apparatus and secretory cytoplasmic vesicles. These data confirm that changes in oral fluid intake can regulate renal tubular epithelial cell OPN expression.

No MeSH data available.


Related in: MedlinePlus

(A) Immunoblots of proteins (10 µg per lane) from renal medulla of control (C), dehydrated (D) and hydrated (H) rats. A distinct band of 70 kD corresponding to the molecular weight of OPN is present. Blots demonstrate increased OPN expression in dehydrated and decreased expression in hydrated kidneys based on comparison of relative optical densities to those of controls (B). *p < 0.05 by t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5037293&req=5

Figure 1: (A) Immunoblots of proteins (10 µg per lane) from renal medulla of control (C), dehydrated (D) and hydrated (H) rats. A distinct band of 70 kD corresponding to the molecular weight of OPN is present. Blots demonstrate increased OPN expression in dehydrated and decreased expression in hydrated kidneys based on comparison of relative optical densities to those of controls (B). *p < 0.05 by t-test.

Mentions: Fig. 1 shows the results of immunoblot analyses and the relative optical densities of proteins from the renal medulla. Immunoblot analysis against OPN showed a single band corresponding to approximately 70 kD, which is characteristic of OPN on standard SDS-polyacrylamide gels. The OPN expression was increased in dehydrated rats (129.2% vs. 100%, p < 0.05), and decreased in hydrated rats (65.7% vs. 100%, p < 0.05) when relative optical densities were compared using control rats as a 100% reference. The OPN protein was undetectable by immunoblot of renal cortical homogenates during these experiments.


Hydration status affects osteopontin expression in the rat kidney
(A) Immunoblots of proteins (10 µg per lane) from renal medulla of control (C), dehydrated (D) and hydrated (H) rats. A distinct band of 70 kD corresponding to the molecular weight of OPN is present. Blots demonstrate increased OPN expression in dehydrated and decreased expression in hydrated kidneys based on comparison of relative optical densities to those of controls (B). *p < 0.05 by t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037293&req=5

Figure 1: (A) Immunoblots of proteins (10 µg per lane) from renal medulla of control (C), dehydrated (D) and hydrated (H) rats. A distinct band of 70 kD corresponding to the molecular weight of OPN is present. Blots demonstrate increased OPN expression in dehydrated and decreased expression in hydrated kidneys based on comparison of relative optical densities to those of controls (B). *p < 0.05 by t-test.
Mentions: Fig. 1 shows the results of immunoblot analyses and the relative optical densities of proteins from the renal medulla. Immunoblot analysis against OPN showed a single band corresponding to approximately 70 kD, which is characteristic of OPN on standard SDS-polyacrylamide gels. The OPN expression was increased in dehydrated rats (129.2% vs. 100%, p < 0.05), and decreased in hydrated rats (65.7% vs. 100%, p < 0.05) when relative optical densities were compared using control rats as a 100% reference. The OPN protein was undetectable by immunoblot of renal cortical homogenates during these experiments.

View Article: PubMed Central - PubMed

ABSTRACT

Osteopontin (OPN) is a secretory protein that plays an important role in urinary stone formation. Hydration status is associated with the development of urolithiasis. This study was conducted to examine the effects of dehydration and hydration on OPN expression in the rat kidney. Animals were divided into three groups, control, dehydrated, and hydrated. Kidney tissues were processed for light and electron microscope immunocytochemistry, in situ hybridization, and immunoblot analysis. Dehydration induced a significant increase in OPN protein expression, whereas increased fluid intake induced a decrease in protein expression. Under control conditions, OPN protein and mRNA expression were only detected in the descending thin limb (DTL). Dehydration induced increased expression in the DTL and the development of detectable expression in the thick ascending limb (TAL). In contrast, OPN expression levels declined to less than the controls in the DTL after hydration, while no expression of either protein or mRNA was detectable in the TAL. Immunoelectron microscopy demonstrated that hydration status altered tubular ultrastructure and intracellular OPN expression in the Golgi apparatus and secretory cytoplasmic vesicles. These data confirm that changes in oral fluid intake can regulate renal tubular epithelial cell OPN expression.

No MeSH data available.


Related in: MedlinePlus