scholarly journals Evaluation of biomarkers for in vitro prediction of drug‐induced nephrotoxicity: comparison of HK ‐2, immortalized human proximal tubule epithelial, and primary cultures of human proximal tubular cells

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Johnny X. Huang ◽  
Geraldine Kaeslin ◽  
Max V. Ranall ◽  
Mark A. Blaskovich ◽  
Bernd Becker ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Primary Cultures ◽  
Proximal Tubular Cells ◽  
Drug Induced ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Human Proximal Tubule

20-Hydroxyeicosatetraenoic acid is formed in response to EGF and is a mitogen in rat proximal tubule

1995 ◽  
Vol 269 (6) ◽  
pp. F806-F816 ◽  
Author(s):  
F. Lin ◽  
A. Rios ◽  
J. R. Falck ◽  
Y. Belosludtsev ◽  
M. L. Schwartzman
Keyword(s):  
Arachidonic Acid ◽  
Proximal Tubule ◽  
Cell Lines ◽  
Primary Cultures ◽  
Cell Number ◽  
Brdu Incorporation ◽  
Maximal Effect ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Proximal Tubular

Hydroxyeicosatetraenoic acid (20-HETE) is a major cytochrome P-450-arachidonic acid metabolite in the rat kidney, and its synthesis along the nephron is specifically localized to the proximal tubule, where receptor density for epidermal growth factor (EGF) is the highest. EGF stimulated endogenous 20-HETE formation in a concentration and time-dependent manner, i.e., from 1.6 to 2.6 +/- 0.3 and 3.0 +/- 0.6 pmol 20-HETE.mg-1.min-1 at 10(-8) and 10(-7) M EGF, respectively. The effect of 20-HETE on proximal tubular cell proliferation was examined using primary cultures of rat proximal tubular cells and proximal tubular-derived cell lines, LLC-PK1 and opossum kidney OK. In both cell lines, 20-HETE increased thymidine incorporation into DNA with maximal effect at 10(-9) M. Addition of 20-HETE to serum-deprived LLC-PK1 or OK cells for 48 h caused a concentration-dependent increase in cell number with maximal effect at 10(-9) M. This effect was specific, as structurally similar eicosanoids such as 20-COOH-arachidonic acid, 19(R)-HETE, and 19(S)-HETE did not increase cell number. In 4-day primary cultures of proximal tubular cells, EGF (10(-9) M) and 20-HETE (10(-9) M) increased bromodeoxyuridine (BrdU) incorporation by 40 and 28%, respectively. Addition of both resulted in a twofold increase in BrdU incorporation. Although 20-HETE synthesis in cultured cells is greatly diminished with time, significant picomolar concentrations can be obtained in 4-day cultures. Addition of 17-octadecynoic acid (17-ODYA), an inhibitor of 20-HETE synthesis, significantly inhibited EGF-stimulated BrdU incorporation. The demonstrations that EGF stimulates proximal tubular 20-HETE production and that the latter is a potent mitogen to these cells suggests that 20-HETE may act as a mediator of the EGF effect on cellular growth in the proximal tubule.

CD36 mediates proximal tubular binding and uptake of albumin and is upregulated in proteinuric nephropathies

2012 ◽  
Vol 303 (7) ◽  
pp. F1006-F1014 ◽  
Author(s):  
Richard J. Baines ◽  
Ravinder S. Chana ◽  
Matthew Hall ◽  
Maria Febbraio ◽  
David Kennedy ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Renal Biopsy ◽  
Renal Diseases ◽  
Creatinine Ratio ◽  
Proximal Tubular Cells ◽  
Opossum Kidney ◽  
Tubular Cells ◽  
Proximal Tubular

Dysregulation of renal tubular protein handling in proteinuria contributes to the development of chronic kidney disease. We investigated the role of CD36 as a novel candidate mediator of albumin binding and endocytosis in the kidney proximal tubule using both in vitro and in vivo approaches, and in nephrotic patient renal biopsy samples. In CD36-transfected opossum kidney proximal tubular cells, both binding and uptake of albumin were substantially enhanced. A specific CD36 inhibitor abrogated this effect, but receptor-associated protein, which blocks megalin-mediated endocytosis of albumin, did not. Mouse proximal tubular cells expressed CD36 and this was absent in CD36 null animals, whereas expression of megalin was equal in these animals. Compared with wild-type mice, CD36 null mice demonstrated a significantly increased urinary protein-to-creatinine ratio and albumin-to-creatinine ratio. Proximal tubular cells expressed increased CD36 when exposed to elevated albumin concentrations in culture medium. Expression of CD36 was studied in renal biopsy tissue obtained from adult patients with heavy proteinuria due to minimal change disease, membranous nephropathy, or focal segmental glomerulosclerosis. Proximal tubular CD36 expression was markedly increased in proteinuric individuals. We conclude that CD36 is a novel mediator influencing binding and uptake of albumin in the proximal tubule that is upregulated in proteinuric renal diseases. CD36 may represent a potential therapeutic target in proteinuric nephropathy.

Carbohydrate metabolism by primary cultures of rabbit proximal tubules

1989 ◽  
Vol 256 (3) ◽  
pp. C532-C539 ◽  
Author(s):  
M. J. Tang ◽  
K. R. Suresh ◽  
R. L. Tannen
Keyword(s):  
Pyruvate Kinase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Cultured Cells ◽  
Primary Cultures ◽  
Lactate Production ◽  
Proximal Tubules ◽  
Glycolytic Metabolism ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Proximal Tubular

Renal proximal tubular epithelia were used to assess the factors responsible for the induction of glycolysis in cultured cells. Primary cultures of rabbit proximal tubules, which achieved confluency at 6 days, exhibited hormonal responsiveness and brush-border characteristics typical of proximal tubular cells. Beginning at day 4, these cultured cells exhibited increased glycolytic metabolism reflected by enhanced glucose uptake and lactate production, along with parallel increases in activity of the glycolytic enzymes, pyruvate kinase and lactate dehydrogenase. The gluconeogenic enzymes, phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FDP), were downregulated, and the cultured cells exhibited lower oxygen consumption rates than fresh tubules. Cells grown on a rocker, to mitigate hypoxia, exhibited a metabolic and enzymatic profile similar to cells grown under still conditions. ATP levels in cultured cells were higher than in fresh tubules. Furthermore, pyruvate kinase activity was higher in cells grown in media containing 0.5 as contrasted with 25 mM glucose. The enhanced glycolytic metabolism exhibited by cultured proximal tubular cells appears to be a characteristic of proliferation and is not a response to hypoxia, the Pasteur effect, or environmental glucose.

scholarly journals Palmitate aggravates proteinuria-induced cell death and inflammation via CD36-inflammasome axis in the proximal tubular cells of obese mice

2018 ◽  
Vol 315 (6) ◽  
pp. F1720-F1731 ◽  
Author(s):  
Lung-Chih Li ◽  
Jenq-Lin Yang ◽  
Wen-Chin Lee ◽  
Jin-Bor Chen ◽  
Chien-Te Lee ◽  
...  
Keyword(s):  
Cell Death ◽  
Tubular Injury ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Caspase 1 ◽  
Proximal Tubular ◽  
Renal Tubular ◽  
Nlrp3 Inflammasomes

High levels of serum free fatty acids (FFAs) and proteinuria have been implicated in the pathogenesis of obesity-related nephropathy. CD36, a class B scavenger receptor, is highly expressed in the renal proximal tubules and mediates FFA uptake. It is not clear whether FFA- and proteinuria-mediated CD36 activation coordinates NLRP3 inflammasomes to induce renal tubular injury and inflammation. In this study, we investigated the roles of CD36 and NLRP3 inflammasomes in FFA-induced renal injury in high-fat diet (HFD)-induced obesity. HFD-fed C57BL/6 mice and palmitate-treated HK2 renal tubular cells were used as in vivo and in vitro models. Immunohistochemical staining showed that CD36, IL-1β, and IL-18 levels increased progressively in the kidneys of HFD-fed mice. Sulfo- N-succinimidyl oleate (SSO), a CD36 inhibitor, attenuated the HFD-induced upregulation of NLRP3, IL-1β, and IL-18 and suppressed the colocalization of NLRP3 and ASC in renal tubular cells. In vitro, SSO abolished the palmitate-induced activation of IL-1β, IL-18, and caspase-1 in HK2 proximal tubular cells. Furthermore, treatment with SSO and the knockdown of caspase-1 expression by siRNA both inhibited palmitate-induced cell death and apoptosis in HK2 cells. Collectively, palmitate causes renal tubular inflammation, cell death, and apoptosis via the CD36/NLRP3/caspase-1 axis, which may explain, at least in part, the mechanism underlying FFA-related renal tubular injury. The blockade of CD36-induced cellular processes is therefore a promising strategy for treating obesity-related nephropathy.

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