Protection by glycine of proximal tubules from injury due to inhibitors of mitochondrial ATP production

1990 ◽  
Vol 258 (6) ◽  
pp. C1127-C1140 ◽  
Author(s):  
J. M. Weinberg ◽  
J. A. Davis ◽  
M. Abarzua ◽  
T. Kiani ◽  
R. Kunkel
Keyword(s):  
Mitochondrial Function ◽  
Structural Integrity ◽  
Cell Injury ◽  
Buthionine Sulfoximine ◽  
Proximal Tubules ◽  
Atp Depletion ◽  
Protective Effects ◽  
Atp Production ◽  
Carbonyl Cyanide ◽  
Severe Impairment

We have determined whether glycine or glutathione can protect rabbit proximal tubules damaged by chemical inhibitors of oxidative phosphorylation: antimycin A, rotenone, cyanide, oligomycin, or carbonyl cyanide m-chlorophenylhdrazone (CCCP). All the agents severely depleted cell ATP levels within 15 min and caused lethal cell injury, as quantified by lactate dehydrogenase (LDH) release. Glycine and glutathione largely prevented this injury without altering the primary effects of the inhibitors on tubule respiration or the depletion of ATP. Buthionine sulfoximine and 1,3-bis(2-chloroethyl)-1-nitrosourea decreased cell glutathione but did not prevent the protective effects of either glycine or glutathione in tubules treated with rotenone. Protection was sustained during both a 15-min exposure and a 45-min postwash period irrespective of whether the wash removed the agent or mitochondrial function recovered. Cysteine uniquely induced a dramatic recovery of mitochondrial function in tubules washed after treatment with CCCP. These data 1) demonstrate that the cytoprotective effects of glycine previously seen during hypoxia extend to other tubule lesions characterized by severe ATP depletion, 2) emphasize the actions of glycine to preserve cell structural integrity in spite of sustained severe impairment of ATP-generating processes in proximal tubules, and 3) indicate that it is glycine rather than intracellular or extracellular glutathione which mediates protection.

Relationships between intracellular amino acid levels and protection against injury to isolated proximal tubules

1991 ◽  
Vol 260 (3) ◽  
pp. F410-F419 ◽  
Author(s):  
J. M. Weinberg ◽  
I. Nissim ◽  
N. F. Roeser ◽  
J. A. Davis ◽  
S. Schultz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Structural Integrity ◽  
Cell Injury ◽  
Amino Acid Content ◽  
Proximal Tubules ◽  
Atp Depletion ◽  
Acute Injury ◽  
Intracellular Amino Acid ◽  
Sites Of Action

Metabolism and cellular levels of glycine, alanine, and other relevant amino acids in proximal tubules were studied during models of acute injury and protection by glycine. Freeze-clamped, normal rabbit renal cortex was very rich in glycine (66.8 nmol/mg protein) and glutamate and also had substantial levels of taurine, alanine, glutamine, serine, and aspartate. Isolated proximal tubules were severely depleted of all these amino acids (glycine, 2.1 nmol/mg protein). During 37 degrees C incubation in presence of alanine, tubules recovered only glutamate to a level approximating that in vivo (38.8 nmol/mg protein, 15.2 mM). Glycine added to medium at levels ranging from 0.25 to 2 mM was actively concentrated four- to sixfold by tubule cells. Two millimolar glycine potently protected tubules from lethal cell injury induced by hypoxia, antimycin A, or ouabain. Glycine levels of injured tubules rapidly equilibrated with medium, irrespective of whether glycine was loaded by preincubation or was added concomitantly with the injury maneuver. Metabolism of glycine during protection, assessed by changes in total levels, gas chromatography-mass spectroscopy determination of the fate of [13C]glycine, and redistribution of label from [3H]glycine was minimal. The data suggest that glycine plays an essential, constitutive role in maintenance of tubule cell structural integrity independently of common metabolic pathways. Intracellular amino acid content is sufficiently labile for depletion of structurally essential amino acids to potentially occur in a variety of settings, but, even with severe ATP depletion or Na+ pump inhibition, supplemental glycine is readily available to intracellular sites of action.

ATP depletion and mitochondrial functional loss during ischemia in slow and fast heart-rate hearts

1990 ◽  
Vol 259 (6) ◽  
pp. H1759-H1766 ◽  
Author(s):  
W. Rouslin ◽  
C. W. Broge ◽  
I. L. Grupp
Keyword(s):  
Mitochondrial Function ◽  
Atp Depletion ◽  
Mitochondrial Atpase ◽  
Small Contribution ◽  
Bicarbonate Buffer ◽  
Tissue Ph ◽  
Atp Production ◽  
Dog Heart ◽  
Rat Hearts

In the present study, isolated dog and rat hearts were perfused in the Langendorff mode with Krebs bicarbonate buffer in the absence and presence of 10(-5) M oligomycin. The perfusion protocols employed allowed tissue pH to drop during subsequent ischemic incubations essentially as it would in blood-perfused hearts. Tissue pH, ATP, lactate, and mitochondrial respiratory function were measured during the course of subsequent zero-flow ischemic incubations. The adenosinetriphosphatase (ATPase) activities attributable to both mitochondrial and nonmitochondrial ATPases in sonicated heart homogenates and the actomyosin ATPase in isolated cardiac myofibrils were measured in both species. Consistent with earlier results with a different model in which tissue pH was buffered during the ischemic incubations [W. Rouslin, J. L. Erickson, and R. J. Solaro. Am. J. Physiol. 250 (Heart Circ. Physiol. 19): H503-H508, 1986], the inhibition of the mitochondrial ATPase in situ by oligomycin markedly slowed both tissue ATP depletion and the loss of mitochondrial function during ischemia in the dog. However, oligomycin had only a very small and transient effect on ATP depletion and mitochondrial function in the rat. This was apparently so because of the fivefold higher rate of glycolytic ATP production as well as the nearly threefold higher total nonmitochondrial ATPase activity of ischemic rat compared with ischemic dog heart. These results suggest that although the inhibition of the mitochondrial ATPase makes a major contribution to ATP conservation in ischemic dog heart, it makes only a very small contribution in rat.

scholarly journals HIF-1-mediated production of exosomes during hypoxia is protective in renal tubular cells

2017 ◽  
Vol 313 (4) ◽  
pp. F906-F913 ◽  
Author(s):  
Wei Zhang ◽  
Xiangjun Zhou ◽  
Qisheng Yao ◽  
Yutao Liu ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Cell Injury ◽  
Hypoxia Inducible Factor ◽  
Atp Depletion ◽  
Tubular Cell ◽  
Renal Tubular Cell ◽  
Dependent Manner ◽  
Protective Effects ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Renal Tubular

Exosomes are nano-sized vesicles produced and secreted by cells to mediate intercellular communication. The production and function of exosomes in kidney tissues and cells remain largely unclear. Hypoxia is a common pathophysiological condition in kidneys. This study was designed to characterize exosome production during hypoxia of rat renal proximal tubular cells (RPTCs), investigate the regulation by hypoxia-inducible factor-1 (HIF-1), and determine the effect of the exosomes on ATP-depletion-induced tubular cell injury. Hypoxia did not change the average sizes of exosomes secreted by RPTCs, but it significantly increased exosome production in a time-dependent manner. HIF-1 induction with dimethyloxalylglycine also promoted exosome secretion, whereas pharmacological and genetic suppression of HIF-1 abrogated the increase of exosome secretion under hypoxia. The exosomes from hypoxic RPTCs had inhibitory effects on apoptosis of RPTCs following ATP depletion. The protective effects were lost in the exosomes from HIF-1α knockdown cells. It is concluded that hypoxia stimulates exosome production and secretion in renal tubular cells. The exosomes from hypoxic cells are protective against renal tubular cell injury. HIF-1 mediates exosome production during hypoxia and contributes to the cytoprotective effect of the exosomes.

Developmental changes in ATP utilization during graded hypoxia and reoxygenation in the heart in vivo

1996 ◽  
Vol 270 (1) ◽  
pp. H216-H223 ◽  
Author(s):  
M. A. Portman ◽  
T. A. Standaert ◽  
X. H. Ning
Keyword(s):  
Mitochondrial Function ◽  
Atp Depletion ◽  
Developmental Changes ◽  
Time Resolved ◽  
Atp Production ◽  
Oxygen Gradient ◽  
Rapid Pcr ◽  
Myocardial O2 Consumption ◽  
Predicted Values

Myocardial ATP utilization and resynthesis during hypoxia and reoxygenation were studied in vivo as a function of maturation. Graded hypoxia was performed in newborn (NB; 4-10 days old, n = 6) and mature sheep (MAT; 30-60 days old, n = 6). Time-resolved 31P-nuclear magnetic resonance was used to monitor myocardial phosphates throughout hypoxia and to monitor reoxygenation concomitant with rate of myocardial O2 consumption (MVO2) measurement. Oxygen delivery and MVO2 were constant in both groups throughout hypoxia, with substantial and similar increases in both parameters during reoxygenation. Hypoxic myocardial lactate release was similar in NB and MAT. Phosphocreatine (PCr), but not ATP, decreased in NB only during milder hypoxia. Rapid PCr and slower ATP depletion occurred with severe hypoxia, consistent with ATP utilization/synthesis imbalance. Depletion rates were higher in MAT. Creatine rephosphorylation rates, measures of mitochondrial function reported as percentage of predicted values, were similar. 34 +/- 12 in NB and 26 +/- 9% in mature lambs. In conclusion, 1) phosphorylation potential decreases in NB but not MAT in response to a decreasing oxygen gradient; 2) ATP utilization during hypoxia increases more in mature lambs; 3) anaerobic ATP production is not greater in NB; and 4) despite the greater energy imbalance imposed on MAT during hypoxia, mitochondrial function is similar to NB during reoxygenation.

Differential effects of respiratory inhibitors on glycolysis in proximal tubules

1990 ◽  
Vol 258 (6) ◽  
pp. F1608-F1615 ◽  
Author(s):  
K. G. Dickman ◽  
L. J. Mandel
Keyword(s):  
Oxidative Metabolism ◽  
Cell Injury ◽  
Lactate Production ◽  
Proximal Tubules ◽  
Antimycin A ◽  
Transport Function ◽  
Atp Production ◽  
Rotenone Treatment ◽  
Glycolytic Atp ◽  
Ldh Release

The effects of inhibition of mitochondrial energy production at various points along the respiratory chain on glycolytic lactate production and transport function were examined in a suspension of purified rabbit renal proximal tubules. Paradoxically, partial blockage at site 3 by hypoxia (1% O2) induced lactate production, whereas total site 3 blockage by anoxia (0% O2) failed to stimulate glycolysis. Compared with anoxia, hypoxic tubules exhibited greater preservation of ATP and K+ contents during O2 deprivation and more fully recovered oxidative metabolism and transport function during reoxygenation. The mitochondrial site 1 inhibitor rotenone and the uncoupler carbonyl cyanide-p-trifluorome-thoxyphenylhydrazone (FCCP) were equipotent stimuli for lactate production, whereas the site 2 inhibitor antimycin A failed to stimulate glycolysis despite a 90% inhibition of O2 consumption. Compared with antimycin A, treatment with rotenone or FCCP resulted in less cell injury [measured by lactate dehydrogenase (LDH) release] and greater preservation of cell K+ and ATP contents. 2-Deoxyglucose blocked lactate production by 50% in the presence of rotenone and increased LDH release, suggesting that glycolytic ATP is partially protective. Addition of ouabain during rotenone treatment reduced lactate production by 50%, indicating that glycolytic ATP can be used to fuel the Na pump when mitochondrial ATP production is inhibited. We conclude that 1) proximal tubules can generate lactate during inhibition of oxidative metabolism by hypoxia, rotenone, or FCCP; 2) mitochondrial inhibition is not obligatorily linked to activation of glycolysis, since neither anoxia nor antimycin A stimulate lactate production; 3) when ATP can be produced through anaerobic glycolysis it serves to protect cell viability and transport function during respiratory inhibition.

Renal mouse proximal tubular cells are more susceptible than MDCK cells to chemical anoxia

1993 ◽  
Vol 265 (3) ◽  
pp. F342-F350 ◽  
Author(s):  
A. M. Sheridan ◽  
J. H. Schwartz ◽  
V. M. Kroshian ◽  
A. M. Tercyak ◽  
J. Laraia ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Cell Injury ◽  
Mdck Cells ◽  
Primary Cultures ◽  
Atp Depletion ◽  
Atp Content ◽  
Atp Production ◽  
Continuous Cell Lines ◽  
Proximal Tubular ◽  
Chemical Anoxia

To elucidate the mechanisms responsible for the resistance of continuous cell lines to anoxic injury, we have compared the effects of ATP depletion induced by chemical anoxia on primary cultures of mouse proximal tubular (MPT) cells and on Madin-Darby canine kidney (MDCK) cells. Inhibition of ATP production by cyanide and 2-deoxyglucose (CN+DOG) in the absence of dextrose reduced cell ATP content to < 5% of control values in MPT cells and caused progressive deterioration in mitochondrial function as well as loss of cell viability in these cells. Cell free fatty acid (FFA) content rose from 4.3 +/- 0.9 to 23.7 +/- 2.0 micrograms/mg of total lipid weight after 4 h of CN + DOG (P < 0.05). The mitochondrial injury and cell death induced by CN + DOG in MPT cells was ameliorated by the addition of fatty acid-free bovine albumin to the cell medium, which reduced cell FFA content during chemical anoxia from 25.0 +/- 3.0 to 10.4 +/- 2.0 micrograms/mg (P < 0.05). The phospholipase A2 (PLA2) inhibitor, mepacrine, also resulted in functional protection and reduction of cell FFA content from 20.2 +/- 2.3 to 15.9 +/- 1.7 micrograms/mg (P < 0.05). These data suggest a role for phospholipase activation and accumulation of toxic lipid metabolites in the pathophysiology of MPT cell injury. We then compared cell injury induced by CN + DOG in MPT and MDCK cells. Despite comparable reduction in cell ATP content in the two cell types, injury was far more severe in MPT than MDCK cells.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Protective effects of glutathione, glycine, or alanine in an in vitro model of renal anoxia.

1992 ◽  
Vol 2 (8) ◽  
pp. 1338-1344 ◽  
Author(s):  
M S Paller ◽  
M Patten
Keyword(s):  
Cell Injury ◽  
Primary Cultures ◽  
Buthionine Sulfoximine ◽  
Experimental Models ◽  
Protective Effects ◽  
Synthesis Inhibitor ◽  
Lactate Dehydrogenase Release ◽  
Reoxygenation Injury ◽  
Vitro Model

Both glutathione and glycine provide some protection against ischemic renal injury in a variety of experimental models. However, results have been inconsistent and there may also be model heterogeneity. The effects of glutathione, glycine, and alanine in a cell culture model of renal anoxia/reoxygenation injury were tested. When primary cultures of rat proximal tubule epithelial cells were subjected to 60 min of anoxia and 30 min of reoxygenation, glutathione (2 mM) essentially eliminated lethal cell injury as determined by lactate dehydrogenase release. Glycine or alanine, on the other hand, provided only partial protection. Glutamate did not protect, although cysteine did. The glutathione synthesis inhibitor buthionine sulfoximine blocked the protective effect of exogenous glutathione, and the glutathione transport inhibitor probenecid partially blocked glutathione protection. A combination of glycine, glutamate, plus cysteine also protected against anoxia/reoxygenation injury. The studies suggest that both glutathione degradation with intracellular resynthesis and transport of intact glutathione into the cell are involved in the protection afforded by exogenous glutathione. These results are different from those obtained in other experimental models of renal ischemia, such as freshly isolated proximal tubules, because the protective effects of glutathione were not derived solely from glycine generation. These studies also suggest the need for caution in extrapolating results from one model of renal anoxic injury to another.

scholarly journals Depletion of ATP and Oxidative Stress Underlie Zinc-Induced Cell Injury

2007 ◽  
Vol 50 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Emil Rudolf
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Cell Death ◽  
Nadph Oxidase ◽  
Cell Injury ◽  
Atp Depletion ◽  
Atp Production ◽  
Apoptosis And Necrosis ◽  
Positive Effect ◽  
And Oxidative Stress

The mechanisms of cell injury resulting in a special type of cell death combining the features of apoptosis and necrosis were examined in Hep-2 cells exposed to 300 μM zinc sulfate during 24h. Acute exposure to zinc induced a rapid rise in metallothionein levels and increased oxidative stress occurring in the absence of a significant early ATP depletion. Accentuated ATP loss and elevated levels of superoxide at later treatment intervals (12h and longer) were present along with increased DNA damage. Manipulation with ATP production and inhibition of NADPH oxidase had a positive effect on zinc-related increase in oxidative stress and influenced the observed type of cell death. These results suggest that Hep-2 cells acutely exposed to zinc increase intracellular labile zinc stores and over express metalothioneins. Elevated production of peroxides in zinc-treated cells is at later treatment intervals accompanied by an increase in superoxide levels, possibly by activation of NADPH oxidase, DNA damage and severe ATP loss. Prevention of critical ATP depletion and, in particular, inhibition of oxidative stress attenuates zinc-mediated cell injury and stimulates apoptosis-like phenotype in exposed cells.

scholarly journals Protective Role ofPsoralea corylifoliaL. Seed Extract against Hepatic Mitochondrial Dysfunction Induced by Oxidative Stress or Aging

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Eunhui Seo ◽  
Yoon Sin Oh ◽  
Donghee Kim ◽  
Mi-Young Lee ◽  
Sungwook Chae ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Hepg2 Cells ◽  
Peroxisome Proliferator ◽  
Ros Production ◽  
Protective Effects ◽  
Peroxisome Proliferator Activated Receptor ◽  
Atp Production ◽  
Genome Damage

The accumulation of oxidative damage and mitochondrial dysfunction is an important factor that contributes to aging. ThePsoralea corylifoliaseeds (PCS), commonly known as “Boh-Gol-Zhee” in Korea, have been used traditionally as a medicinal remedy. We investigated whether an extract of PCS has protective effects on oxidative stress and mitochondrial function in hepatocytes. The PCS extract showed an antisenescence effect on human diploid fibroblasts as evidenced by a decreased expression ofp16INK4amRNA and senescence-associatedβ-galactosidase staining. PCS extract treatment reduced H2O2-induced reactive oxygen species (ROS) production in HepG2 cells, inhibited ROS production in hepatocytes of aged mice, and increased superoxide dismutase activity. In H2O2-treated HepG2 cells, PCS extract treatment recovered ATP production. PCS extract treatment recovered the oxygen consumption rate and inhibited reduction of mitochondrial membrane potential induced by oxidative stress, suggesting improvement of mitochondrial function. In addition, PCS extract treatment recovered peroxisome proliferator-activated receptorγcoactivator 1αand carnitine palmitoyltransferase 1 mRNA and protein expression, and inhibited mitochondrial genome damage. Treatment with the major component of PCS extract, bakuchiol, also recovered mitochondrial dysfunction. On the basis of these results, we conclude that PCS extract inhibits ROS production and mitochondrial dysfunction induced by oxidative stress in hepatocytes.

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