Temperature-sensitive SV40 immortalized rat proximal tubule cell line has functional renin-angiotensin system

1995 ◽  
Vol 268 (3) ◽  
pp. F435-F446 ◽  
Author(s):  
S. S. Tang ◽  
F. Jung ◽  
D. Diamant ◽  
D. Brown ◽  
D. Bachinsky ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Renin Angiotensin System ◽  
Temperature Sensitive ◽  
Proximal Tubule Cell ◽  
Permissive Temperature ◽  
Ang Ii ◽  
Tubule Cell ◽  
Angiotensin System ◽  
Rat Proximal Tubule

Immortalized rat proximal tubule cell (IRPTC) lines should be useful for investigation of proximal tubule (PT) regulation and function but previously have been unavailable. We now report the establishment and characterization of an immortalized transformed, temperature-sensitive IRPTC cell line containing renin-angiotensin system (RAS) components. Primary PT cells prepared from male Wistar rats (4-5 wk old) after collagenase digestion, sieving, and Percoll gradient were cultured on collagen-coated T-75 flasks in Dulbecco's modified Eagle's medium containing 5% fetal calf serum. Subconfluent PT cells were transfected with the temperature-sensitive SV40 mutant viruses (tsA SV40) by direct exposure. After 7-8 wk, several clones were obtained, from which one has been characterized and designated as line 3-2. This cell line appears stable up to 45 passages. Clonal cells transformed with this virus exhibit a transformed phenotype at a permissive temperature of 34 degrees C and grow in multiple layers. When the cells are subsequently placed at a nonpermissive temperature of 41 degrees C, they return to morphology similar to that of untransformed cells of the same lineage. At either 34 degrees C or 41 degrees C, this cell line expresses a variety of PT markers including alkaline phosphatase, cytokeratin, carbonic anhydrase, and glucose transporter isoform 2 (GLUT2), while not expressing factor VIII. Uniquely, these cells also appear to express PT proteins gp330 and CHIP28, markers which are usually lost in cultured cells. Furthermore, the cell line expresses protein and mRNA components of RAS, including angiotensinogen, angiotensin converting enzyme, and renin. The IRPTC cell line expresses few angiotensin II (ANG II) receptors at 34 degrees C, the permissive temperature. However, at the nonpermissive temperature, 41 degrees C, IRPTC expresses ANG II receptor (dissociation constant of 0.7 nM; maximum binding capacity of 265 fmol/mg protein). ANG II (10(-8) M) induced a transient rise in cytoplasmic Ca2+ concentration, which was nearly abolished with losartan but not PD-123319, suggesting this finding is AT1 receptor mediated. This cell line should provide an excellent model of PT and should make it possible to study the cell and molecular biology of the RAS, as well as other regulatory systems of the PT.

Rat proximal tubule cell line transformed with origin-defective SV40 DNA: autocrine ANG II feedback

1999 ◽  
Vol 276 (2) ◽  
pp. F218-F227 ◽  
Author(s):  
Julie R. Ingelfinger ◽  
Flavia Jung ◽  
Daniel Diamant ◽  
Liam Haveran ◽  
Edwin Lee ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Renin Angiotensin System ◽  
Receptor Subtypes ◽  
Proximal Tubule Cell ◽  
Ang Ii ◽  
Angiotensin System ◽  
Main Site ◽  
Sv40 Dna ◽  
Competition Assays

The renal proximal tubule (PT) is a major site for a complete tissue renin-angiotensin system (RAS) and produces endogenous angiotensin II (ANG II). The present studies demonstrate autocrine RAS feedback in a line of origin-defective SV40 plasmid transformed immortalized rat PT cells (IRPTC) designated as line 93-p-2–1, which are highly differentiated and express all RAS components. Receptor competition assays and Southern blot following RT-PCR demonstrated that these IRPTC express AT1 and AT2 angiotensin receptor subtypes. Autocrine RAS feedback was examined following exposure to ANG II (10−8 M), and it was noted that angiotensinogen mRNA increases significantly by 1 h and remains elevated through 24 h. The AT1 blocker losartan prevents this increase. Moreover, ANG II upregulates expression of ANG II receptor mRNA (both AT1 and AT2). Thus the present studies demonstrate positive ANG II feedback with angiotensinogen and ANG II receptors in PTC, suggesting that the main site of such intrarenal feedback in vivo is within PT. ANG II secreted by line 93-p-2–1 is increased by isoproterenol, suggesting β-adrenergic regulation in IRPTC.

scholarly journals The actin cytoskeleton and integrin expression in the recovery of cell adhesion after oxidant stress to a proximal tubule cell line (JTC-12).

1998 ◽  
Vol 9 (10) ◽  
pp. 1787-1797
Author(s):  
S Nigam ◽  
C E Weston ◽  
C H Liu ◽  
E E Simon
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Proximal Tubule ◽  
Cell Line ◽  
Oxidant Stress ◽  
Proximal Tubule Cell ◽  
Integrin Expression ◽  
Tubule Cell ◽  
Essentially Normal ◽  
Atp Levels

This study examines the role of the actin cytoskeleton and integrin expression in the recovery of cell adhesion in the proximal tubule cell line JTC-12 after peroxide injury. The cells were exposed to 10, 20, or 50 mM hydrogen peroxide for 10 min and then allowed to recover. Viability measurements by trypan blue exclusion confirmed that the injury was largely nonlethal with 85% viability at 1 h even at 50 mM peroxide. ATP levels fell immediately after the peroxide incubation in all groups to approximately 10% of normal, but already showed some recovery by 1 h and full recovery in the 10 and 20 mM groups by 24 h. Cell adhesion to extracellular matrix immediately after injury was depressed at 20 and 50 mM peroxide, but by 12 h was abnormal only at 50 mM peroxide and at 24 h was essentially normal at all peroxide concentrations. Immediately after exposure to 10 mM peroxide, there were subtle abnormalities in the actin cytoskeleton (thickening of fibrils) as assessed by phalloidin staining, with more pronounced effects at 20 and 50 mM. At 1 h, many cells showed collapse of the actin cytoskeleton to the periphery. There was some recovery at 4 h; by 12 h, the actin cytoskeleton showed further recovery, although was still abnormal (coarsened microfilaments), especially at 20 and 50 mM peroxide. By 24 h, the actin cytoskeleton showed only subtle coarsening. Integrin surface expression was assessed by flow cytometry. The alpha6 subunit on cells exposed to 20 mM peroxide was unchanged at 1 h and 4 h, but by 12 h had increased to 118.5+/-4.5% and by 24 h to 146+/-13.4% of control levels. The expression of the beta1 and alphaVbeta3 integrins remained unchanged. Thus, despite coarsening of the actin cytoskeleton and depressed ATP levels, cell adhesion recovered from oxidant stress. Abnormal cell adhesion after injury was not a consequence of a decrease in integrin expression, and recovery of cell adhesion was not a consequence of the modest and selective increase in integrin expression.

Expression of xenobiotic transporters in the human renal proximal tubule cell line RPTEC/TERT1

2015 ◽  
Vol 30 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Lydia Aschauer ◽  
Giada Carta ◽  
Nadine Vogelsang ◽  
Eberhard Schlatter ◽  
Paul Jennings
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Renal Proximal Tubule ◽  
Proximal Tubule Cell ◽  
Tubule Cell

Nitric oxide activates PKCα and inhibits Na+-K+-ATPase in opossum kidney cells

1999 ◽  
Vol 277 (6) ◽  
pp. F859-F865 ◽  
Author(s):  
Mingyu Liang ◽  
Franklyn G. Knox
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Proximal Tubule ◽  
Cell Line ◽  
Soluble Guanylate Cyclase ◽  
Inhibitory Effect ◽  
Proximal Tubule Cell ◽  
Tubule Cell ◽  
Opossum Kidney ◽  
Ok Cells

Nitric oxide (NO) reduces the molecular activity of Na+-K+-ATPase in opossum kidney (OK) cells, a proximal tubule cell line. In the present study, we investigated the cellular mechanisms for the inhibitory effect of NO on Na+-K+-ATPase. Sodium nitroprusside (SNP), a NO donor, inhibited Na+-K+-ATPase in OK cells, but not in LLC-PK1cells, another proximal tubule cell line. Similarly, phorbol 12-myristate 13-acetate, a protein kinase C (PKC) activator, inhibited Na+-K+-ATPase in OK, but not in LLC-PK1, cells. PKC inhibitors staurosporine or calphostin C, but not the protein kinase G inhibitor KT-5823, abolished the inhibitory effect of NO on Na+-K+-ATPase in OK cells. Immunoblotting demonstrated that treatment with NO donors caused significant translocation of PKCα from cytosolic to particulate fractions in OK, but not in LLC-PK1, cells. Furthermore, the translocation of PKCα in OK cells was attenuated by either the phospholipase C inhibitor U-73122 or the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one. U-73122 also blunted the inhibitory effect of SNP on Na+-K+-ATPase in OK cells. The phospholipase A2inhibitor AACOCF3 did not blunt the inhibitory effect of SNP on Na+-K+-ATPase in OK cells. AACOCF3 alone, however, also decreased Na+-K+-ATPase activity in OK cells. In conclusion, our results demonstrate that NO activates PKCα in OK, but not in LLC-PK1, cells. The activation of PKCα in OK cells by NO is associated with inhibition of Na+-K+-ATPase.

Angiotensin (AT1A) receptor-mediated increases in transcellular sodium transport in proximal tubule cells

1998 ◽  
Vol 274 (5) ◽  
pp. F897-F905 ◽  
Author(s):  
Thomas J. Thekkumkara ◽  
Rochelle Cookson ◽  
Stuart L. Linas
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Epithelial Tissue ◽  
Proximal Tubule Cell ◽  
Ang Ii ◽  
Binding Studies ◽  
Proximal Tubule Cells ◽  
Tubule Cells ◽  
And Function ◽  
In Cells

Angiotensin II (ANG II), acting through angiotensin type 1A receptors (AT1A), is important in regulating proximal tubule salt and water balance. AT1A are present on apical (AP) and basolateral (BL) surfaces of proximal tubule epithelial cells (PTEC). The molecular mechanism of AT1A function in epithelial tissue is not well understood, because specific binding of ANG II to intact PTEC has not been found and because a number of isoforms of AT receptors are present in vivo. To overcome this problem, we developed a cell line from opossum kidney (OK) proximal tubule cells, which stably express AT1A( K d = 5.27 nM, Bmax = 6.02 pmol/mg protein). Characterization of nontransfected OK cells revealed no evidence of AT1A mRNA (reverse transcriptase-polymerase chain reaction analysis) or protein (125I-labeled ANG II binding studies) expression. In cells stably expressing AT1A, ANG II binding was saturable, reversible, and regulated by G proteins. Transfected receptors were coupled to increases in intracellular calcium and inhibition of cAMP. To determine the polarity of AT1A expression and function in proximal tubules, transfected cells were grown to confluence on membrane inserts under conditions that allowed selective access to AP or BL surfaces. AT1A were expressed on both AP ( K d = 8.7 nM, Bmax = 3.33 pmol/mg protein) and BL ( K d = 10.1 nM, Bmax = 5.50 pmol/mg protein) surfaces. Both AP and BL AT1Areceptors underwent agonist-dependent endocytosis (AP receptor: t 1/2 = 7.9 min, Ymax = 78.5%; BL receptor: t 1/2 = 2.1 min, Ymax = 86.3%). In cells transfected with AT1A, ANG II caused time- and concentration-dependent increases in transepithelial22Na transport (2-fold over control at 20 min) by increasing Na/H exchange. In conclusion, we have established a stable proximal tubule cell line that expresses AT1A on both AP and BL surfaces, undergoes agonist-dependent receptor endocytosis, and is functional, as evidenced by inhibition of cAMP and increases in cytosolic calcium mobilization and transepithelial sodium movement. This cell line should prove useful for understanding the molecular and biochemical regulation of AT1A expression and function in PTEC.

The intrarenal renin-angiotensin system in autosomal dominant polycystic kidney disease

2004 ◽  
Vol 287 (4) ◽  
pp. F775-F788 ◽  
Author(s):  
Mahmoud Loghman-Adham ◽  
Carlos E. Soto ◽  
Tadashi Inagami ◽  
Lisa Cassis
Keyword(s):  
Kidney Disease ◽  
Proximal Tubule ◽  
Polycystic Kidney Disease ◽  
Autosomal Dominant ◽  
Renin Angiotensin System ◽  
Distal Tubule ◽  
Ang Ii ◽  
Polycystic Kidney ◽  
Angiotensin System ◽  
Autosomal Dominant Polycystic Kidney

Hypertension is a common complication of autosomal dominant polycystic kidney disease (ADPKD), often present before the onset of renal failure. A role for the renin-angiotensin system (RAS) has been proposed, but studies of systemic RAS have failed to show a correlation between plasma renin activity and blood pressure in ADPKD. Ectopic renin expression by cyst epithelium was first reported in 1992 (Torres VE, Donovan KA, Sicli G, Holley KE, Thibodeau ST, Carretero OA, Inagami T, McAteer JA, and Johnson CM. Kidney Int 42: 364–373, 1992). It is not known, however, whether other RAS components are also expressed by cysts in ADPKD. We show that, in addition to renin, angiotensinogen (AGT) is produced by some cysts and dilated tubules. Angiotensin-converting enzyme, ANG II type 1 receptor, and ANG II peptide are also present within cysts and in many tubules; and some cyst fluids contain high ANG II concentrations. Additionally, cyst-derived cells in culture continue to express the components of the RAS at both the protein and mRNA levels. We further show that renin is expressed primarily in cysts of distal tubule origin and in cyst-derived cells with distal tubule characteristics, whereas AGT is expressed primarily in cysts of proximal tubule origin and in cyst-derived cells with proximal tubule characteristics. Renin production by cyst-derived cells appears to be regulated by extracellular Na+ concentration. Based on these observations, we propose a model of an autocrine/paracrine RAS in polycystic kidney disease, whereby overactivity of the intrarenal system results in sustained increases in intratubular ANG II concentrations.

scholarly journals P-GLYCOPROTEIN IN HK-2 PROXIMAL TUBULE CELL LINE

Renal Failure ◽  
2001 ◽  
Vol 23 (3-4) ◽  
pp. 331-337 ◽  
Author(s):  
Gianfranco Tramonti ◽  
Nadia Romiti ◽  
Maria Norpoth ◽  
Elisabetta Chieli
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Proximal Tubule Cell ◽  
Tubule Cell ◽  
P Glycoprotein

scholarly journals Long-term in vitro effects of exposing the human HK-2 proximal tubule cell line to 3-monochloropropane-1,2-diol

2020 ◽  
Vol 45 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Miriam E. Mossoba ◽  
Mapa S.T. Mapa ◽  
Magali Araujo ◽  
Yang Zhao ◽  
Brenna Flannery ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Proximal Tubule Cell ◽  
Tubule Cell

In Vitro to In Vivo Concordance of Toxicity Using the Human Proximal Tubule Cell Line HK-2

2020 ◽  
Vol 39 (5) ◽  
pp. 452-464
Author(s):  
Miriam E. Mossoba ◽  
Robert L. Sprando
Keyword(s):  
Proximal Tubule ◽  
Cell Line ◽  
Cell Injury ◽  
Culture Media ◽  
Sugar Transport ◽  
Molecular Characteristics ◽  
Proximal Tubule Cell ◽  
Tubule Cell

The renal proximal tubule cell line, human kidney 2 (HK-2), recapitulates many of the functional cellular and molecular characteristics of differentiated primary proximal tubule cells. These features include anchorage dependence, gluconeogenesis capability, and sodium-dependent sugar transport. In order to ascertain how well HK-2 cells can reliably reveal the toxicological profile of compounds having a potential to cause proximal tubule injury in vivo, we sought to evaluate the effects of known proximal tubule toxicants using the HK-2 cell line. We selected 20 pure nephrotoxic compounds that included chemotherapeutic drugs, antibiotics, and heavy metal-containing compounds and evaluated their ability to induce HK-2 cell injury relative to 10 innocuous pure compounds or cell culture media alone. We performed a comprehensive set of in vitro cellular toxicological assays to evaluate cell viability, oxidative stress, mitochondrial integrity, and a specific biomarker of renal injury, Kidney Injury Molecule 1. For each of our selected compounds, we were able to establish a reproducible profile of toxicological outcomes. We compared our results to those described in peer-reviewed publications to understand how well the HK-2 cellular model agrees with overall in vivo rat or human toxicological outcomes. This study begins to address the question of how well in vitro data generated with HK-2 cells can mirror in vivo animal and human outcomes.

Sign in / Sign up

Export Citation Format

Share Document