INTRACELLULAR PH IN LIVER CELL INJURY

Project: Research project

Description

Intracellular depletion of ATP and a decrease in intracellular pH are
prominent features of anoxic and other types of cell injury, Although the
effects of ATP depletion have drawn considerable attention, there is a
lack of basic information regarding the effects of intracellular pH (pHi)
in cell damage. Preliminary experiments by us in rat hepatocytes
demonstrated that an acidic pHi developed during ATP depletion and
protected against the onset of cell death. The overall objective of this
proposal is to extend this observation by testing the hypothesis that (1)
intracellular acidosis develops in all liver cells during anoxic,
oxidative and hypoxic stress, and that (ii) an acidic pHi exerts a
protective effect by inhibition of a specific, identifiable mechanism
responsible for lethal cell injury. The specific aims are:1) to establish
individual models for cell injury in hepatocytes, endothelial, Kupffer
and bile duct epithelial cells isolated from rat liver and to determine
the influence of intracellular and extracellular pH on cell killing; 2)
to determine pHi during basal conditions and cell injury; 3) to determine
the contribution of plasma membrane transporters to pHi homeostasis
during basal conditions and cell injury; 4) to determine the pH
dependence of possible causative mechanisms responsible for cell death;
and 5) to determine the effect of pHi on specific cell functions. These
studies will employ cultures and suspensions of liver cells and utilize
novel biochemical and fluorescent imaging techniques. Employing single,
cultured cells, fluorescent probes and multiparameter digitized video
microscopy, pHi, cytosolic free Ca+2, mitochondrial membrane potential,
loss of cell viability, organic anion transport, rates of fluid phase and
receptor-mediated endocytosis, and changes in cytosolic free Ca+2
mediated by hormonal stimulation will be determined during basal
conditions and during cell injury. In dispersed cell suspensions, rates
of cell killing, proteolysis, phospholipid hydrolysis, ATP depletion,
intracellular H2O2 generation, lipid peroxidation and thiol depletion
will be measured and the effect of pHi on these various processes
evaluated. The results will provide fundamental new insight into the role
of pHi in cell injury, permit identification of common and dissimiliar
mechanisms culminating in cell death, and provide an understanding of
hepatic dysfunction during liver injury. In addition, the results may
lead to the identification of treatment modalities effective in the
preservation of liver tissue during anoxic, oxidative and hypoxic
insults.
StatusActive
Effective start/end date8/1/893/31/20

Funding

  • National Institutes of Health: $208,749.00
  • National Institutes of Health: $317,878.00
  • National Institutes of Health: $246,925.00
  • National Institutes of Health: $211,558.00
  • National Institutes of Health: $41,746.00
  • National Institutes of Health: $312,617.00
  • National Institutes of Health: $323,955.00
  • National Institutes of Health: $246,925.00
  • National Institutes of Health: $219,865.00
  • National Institutes of Health: $12,395.00
  • National Institutes of Health: $357,750.00
  • National Institutes of Health
  • National Institutes of Health: $357,750.00
  • National Institutes of Health: $394,250.00
  • National Institutes of Health: $327,372.00
  • National Institutes of Health: $323,955.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $325,435.00
  • National Institutes of Health: $99,635.00
  • National Institutes of Health: $311,520.00
  • National Institutes of Health: $335,250.00
  • National Institutes of Health: $246,925.00
  • National Institutes of Health: $53,127.00
  • National Institutes of Health: $246,925.00
  • National Institutes of Health: $323,955.00
  • National Institutes of Health: $35,628.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $246,925.00

Fingerprint

Liver
Wounds and Injuries
Apoptosis
Bile Acids and Salts
Hepatocytes
Nonesterified Fatty Acids
Poisons
TNF-Related Apoptosis-Inducing Ligand Receptors
1-Phosphatidylinositol 4-Kinase
Proteolysis
Cell Membrane
Cholestasis
Cell Death
Death Domain Receptor Signaling Adaptor Proteins
Peptide Hydrolases
Calpain
Caspases
CD95 Antigens
Adenosine Triphosphate
Caspase 8

ASJC

  • Medicine(all)