» Articles » PMID: 8328956

Rat Liver Mitochondrial Phospholipase A2 is an Endotoxin-stimulated Membrane-associated Enzyme of Kupffer Cells Which is Released During Liver Perfusion

Overview
Journal Biochem J
Specialty Biochemistry
Date 1993 Jul 1
PMID 8328956
Citations 5
Authors
Affiliations
Soon will be listed here.
Abstract

A novel fluorescence assay for phospholipase A2 [Wilton (1990) Biochem. J. 266, 435-439] has been used to study the Group-II rat liver mitochondrial enzyme, and a number of novel properties of this enzyme were identified. (1) The enzyme activity was located in the liver macrophages (Kupffer cells) while negligible activity was associated with hepatocytes. (2) Although subcellular fractionation of whole liver confirmed the predominantly mitochondrial location of this enzyme activity, the analysis of the hepatocyte-free Kupffer-cell-enriched fraction revealed a different enzyme distribution, with the majority of activity being associated with the microsomal membrane fraction. (3) Bacterial endotoxin has been previously shown to be scavenged by Kupffer cells in rats. Treatment of rats with bacterial lipopolysaccharide (endotoxin) resulted in a dramatic time- and dose-dependent increase in liver phospholipase A2 activity. (4) It is known that injection of endotoxin into rodents results in elevated serum phospholipase A2 activity, while a similar phenomenon is seen in the condition of septic shock in man. The source of this serum enzyme was unknown. In this study perfusion of livers from rats pretreated with lipopolysaccharide with physiological saline demonstrated a 6-fold increase in phospholipase A2 activity in the perfusate compared with sham-treated controls, with only minor release of hepatic lipase. (5) Western-blot analysis confirmed an increased release of this Group-II phospholipase A2 into the perfusate of lipopolysaccharide-treated rats compared with sham-treated controls. These results suggest that liver Kupffer cells are a major source of the endotoxin-induced serum Group-II phospholipase A2 activity associated with bacterial infection and trauma.

Citing Articles

S-Adenosylmethionine Decreases Bacterial Translocation, Proinflammatory Cytokines, Oxidative Stress and Apoptosis Markers in Hepatic Ischemia-Reperfusion Injury in Wistar Rats.

Valdes S, Paredes S, Garcia Carreras C, Zuluaga P, Rancan L, Linillos-Pradillo B Antioxidants (Basel). 2023; 12(8).

PMID: 37627534 PMC: 10451188. DOI: 10.3390/antiox12081539.


Regulation of the Ca(2+)-independent phospholipase A2 in liver mitochondria by changes in the energetic state.

Rauckhorst A, Broekemeier K, Pfeiffer D J Lipid Res. 2014; 55(5):826-36.

PMID: 24586040 PMC: 3995461. DOI: 10.1194/jlr.M043307.


Reactive oxygen species, mitochondria, apoptosis and aging.

Papa S, Skulachev V Mol Cell Biochem. 1997; 174(1-2):305-19.

PMID: 9309704


Oxidative damage and mitochondrial decay in aging.

Shigenaga M, Hagen T, Ames B Proc Natl Acad Sci U S A. 1994; 91(23):10771-8.

PMID: 7971961 PMC: 45108. DOI: 10.1073/pnas.91.23.10771.


Enhanced hydrolysis of phosphatidylcholine by human group II non-pancreatic secreted phospholipase A2 as a result of interfacial activation by specific anions. Potential role of cholesterol sulphate.

Kinkaid A, Wilton D Biochem J. 1995; 308 ( Pt 2):507-12.

PMID: 7772034 PMC: 1136954. DOI: 10.1042/bj3080507.

References
1.
Vadas P, Pruzanski W, Stefanski E . Extracellular phospholipase A2: causative agent in circulatory collapse of septic shock?. Agents Actions. 1988; 24(3-4):320-5. PMC: 7096008. DOI: 10.1007/BF02028289. View

2.
Ono T, Tojo H, Kuramitsu S, KAGAMIYAMA H, Okamoto M . Purification and characterization of a membrane-associated phospholipase A2 from rat spleen. Its comparison with a cytosolic phospholipase A2 S-1. J Biol Chem. 1988; 263(12):5732-8. View

3.
Ishizaki J, Ohara O, Nakamura E, Tamaki M, Ono T, Kanda A . cDNA cloning and sequence determination of rat membrane-associated phospholipase A2. Biochem Biophys Res Commun. 1989; 162(3):1030-6. DOI: 10.1016/0006-291x(89)90777-8. View

4.
Arthur M, Friedman S, Roll F, BISSELL D . Lipocytes from normal rat liver release a neutral metalloproteinase that degrades basement membrane (type IV) collagen. J Clin Invest. 1989; 84(4):1076-85. PMC: 329763. DOI: 10.1172/JCI114270. View

5.
Komada M, Kudo I, Mizushima H, Kitamura N, Inoue K . Structure of cDNA coding for rat platelet phospholipase A2. J Biochem. 1989; 106(4):545-7. DOI: 10.1093/oxfordjournals.jbchem.a122890. View