Distribution of Cell Membrane-associated Proteins Along the Human Nephron

Kwon, Oh Hun; Bd, Myers; Sibley, R; Dafoe, Donald C.; Alfrey, Edward J.; Wj, Nelson

doi:10.1177/002215549804601211

Cited by 28 publications

(19 citation statements)

References 58 publications

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“…3). The pattern of localization appeared to parallel renal occludin immunostaining patterns in other vertebrates (Furuse et al, 1993;Kwon et al, 1998;González-Mariscal et al, 2000;Chasiotis and Kelly, 2008). More specifically, the presence of occludin immunostaining was observed in 'tighter' regions of the amphibian nephron (e.g.…”

Section: Occludin Expression and Localization In Xenopussupporting

confidence: 52%

Occludin and hydromineral balance inXenopus laevis

Chasiotis

Kelly

2009

Journal of Experimental Biology

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SUMMARYTo investigate the response of the tight junction (TJ) protein occludin to environmental change in an anuran amphibian, we examined occludin tissue distribution, immunolocalization and alterations in mRNA expression in African clawed frogs (Xenopus laevis) acclimated to brackish water (BW) conditions (from freshwater to 2‰, 5‰ or 10‰ salt water). Occludin mRNA is widely expressed in Xenopus and is abundant in tissues involved in regulating salt and water balance, such as the gastrointestinal (GI) tract, kidney and urinary bladder. Immunohistochemical analyses revealed strong occludin immunolabelling in the apicolateral region of epithelia lining the GI tract and mRNA expression increased along the longitudinal axis of the gut. In kidney tissue, occludin was differentially expressed on the luminal side of the nephron tubule, appearing in the distal tubules and collecting ducts only. In response to BW acclimation, Xenopus exhibited a significant loss of tissue water as well as salinity-dependent elevations in serum osmolality as a result of increased urea levels followed by elevated serum Na + and Cl -levels. Tissue-specific alterations in the ionomotive enzyme Na

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Section: Occludin Expression and Localization In Xenopussupporting

confidence: 52%

Occludin and hydromineral balance inXenopus laevis

Chasiotis

Kelly

2009

Journal of Experimental Biology

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“…Furthermore, specific patterns of Na al., 1995; Kwon et al, 1998;Sabolic et al, 1999;Sturla et al, 2003). The differential occludin expression patterns observed in the goldfish nephron were similar to those observed in the mammalian kidney (Kwon et al, 1998;González-Mariscal et al, 2000). In mammals, differential occludin immunostaining patterns correlate with renal epithelial 'tightness', such that 'tighter' nephron segments (as determined by TER measurements) express higher levels of occludin protein than 'leakier' nephron regions.…”

Section: Discussion Overviewmentioning

confidence: 73%

“…Similar differential Na + ,K + -ATPase staining patterns have been observed in other fish species and basolateral localization of Na + ,K + -ATPase concurs with models illustrating region-specific ion transport mechanisms in fish renal epithelia (Nebel et al, 2005;Beyenbach, 2004). Furthermore, specific patterns of Na al., 1995; Kwon et al, 1998;Sabolic et al, 1999;Sturla et al, 2003). The differential occludin expression patterns observed in the goldfish nephron were similar to those observed in the mammalian kidney (Kwon et al, 1998;González-Mariscal et al, 2000).…”

Section: Discussion Overviewmentioning

confidence: 74%

“…In mammals, differential occludin immunostaining patterns correlate with renal epithelial 'tightness', such that 'tighter' nephron segments (as determined by TER measurements) express higher levels of occludin protein than 'leakier' nephron regions. In human and rabbit renal tubules, occludin immunostaining was weakest in 'leaky' proximal tubules and strongest in 'tight' distal tubules (Kwon et al, 1998;González-Mariscal et al, 2000). Furthermore, Western blot analysis of microdissected rabbit renal tubules revealed low occludin protein expression in 'leaky' proximal tubules and significantly higher occludin protein expression in 'tight' distal and collecting segments (González-Mariscal et al, 2000).…”

Section: Discussion Overviewmentioning

confidence: 92%

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Occludin immunolocalization and protein expression in goldfish

Chasiotis

Kelly

2008

Journal of Experimental Biology

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SUMMARYTight junctions (TJs) are an integral component of models illustrating ion transport mechanisms across fish epithelia; however, little is known about TJ proteins in fishes. Using immunohistochemical methods and Western blot analysis, we examined the localization and expression of occludin, a transmembrane TJ protein, in goldfish tissues. In goldfish gills, discontinuous occludin immunostaining was detected along the edges of secondary gill lamellae and within parts of the interlamellar region that line the lateral walls of the central venous sinus. In the goldfish intestine, occludin immunolocalized in a TJ-specific distribution pattern to apical regions of columnar epithelial cells lining the intestinal lumen. In the goldfish kidney, occludin was differentially expressed in discrete regions of the nephron. Occludin immunostaining was strongest in the distal segment of the nephron, moderate in the collecting duct and absent in the proximal segment. To investigate a potential role for occludin in the maintenance of the hydromineral balance of fishes, we subjected goldfish to 1, 2 and 4 weeks of food deprivation, and then examined the endpoints of hydromineral status, Na + ,K + -ATPase activity and occludin protein expression in the gills, intestine and kidney. Occludin expression altered in response to hydromineral imbalance in a tissue-specific manner suggesting a dynamic role for this TJ protein in the regulation of epithelial permeability in fishes.

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“…A mobile phase consisting of water containing 0.1% formic acid (A) and acetonitrile containing 0.1% formic acid (B) was employed. A flow Ernest et al, 1997;Kwon et al, 1998;Miyanaka et al, 1998;Motohashi et al, 2002;Reyes et al, 2002;Higgins et al, 2004;Kuusniemi et Proteomics Analysis of OCT-Embedded Tissue Samples Table 1S). MS/MS analysis was performed by monitoring the surrogate peptides and the internal standards using instrument parameters provided in Supplemental Table 1S.…”

Section: Methodsmentioning

confidence: 99%

An Optimized Method for Protein Extraction from OCT-Embedded Human Kidney Tissue for Protein Quantification by LC-MS/MS Proteomics

Vrana

Goodling

Afkarian

et al. 2016

Drug Metabolism and Disposition

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The existing biobanks of remnant tissue from clinically indicated kidney biopsies are attractive potential reservoirs for quantification of clinically relevant human tissue proteins by quantitative proteomics. However, a significant caveat of this strategy is that the tissues are often preserved in optimal cutting temperature (OCT) medium. Although OCT is an effective method of preserving the morphologic and immunohistological characteristics of tissues for later study, it significantly impacts efforts to quantify protein expression by liquid chromatography-tandem mass spectrometry methods. We report here a simple, reproducible, and cost-effective procedure to extract proteins from OCT-embedded tissue samples. Briefly, the excess frozen OCT medium was scraped before thawing from the tissue specimens stored at -80°C for ∼3 months. The tissue samples were homogenized and diethyl ether/methanol extraction was performed to remove the remaining OCT medium. The recovered protein was denatured, reduced, and alkylated. The second step of protein extraction and desalting was performed by chloroform/methanol/ water extraction of denatured proteins. The resultant protein pellet was trypsin-digested and the marker proteins of various kidney cellular compartments were quantified by targeted selective reaction monitoring proteomics. Upon comparison of peptide signals from OCT-embedded tissue and flash-frozen tissue from the same donors, both individual protein quantities, and their interindividual variabilities, were similar. Therefore, the approach reported here can be applied to clinical reservoirs of OCT-preserved kidney tissue to be used for quantitative proteomics studies of clinically relevant proteins expressed in different parts of the kidney (including drug transporters and metabolizing enzymes).

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Distribution of Cell Membrane-associated Proteins Along the Human Nephron

Cited by 28 publications

References 58 publications

Occludin and hydromineral balance inXenopus laevis

Occludin and hydromineral balance inXenopus laevis

Occludin immunolocalization and protein expression in goldfish

An Optimized Method for Protein Extraction from OCT-Embedded Human Kidney Tissue for Protein Quantification by LC-MS/MS Proteomics

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