Glucose deprivation increases hydrogen peroxide level in immunostimulated rat primary astrocytes.
Activated astrocytes produce a large amount of bioactive molecules, including reactive oxygen and nitrogen species. Astrocytes are in general resistant to those reactive species. However, we previously reported that immunostimulated astrocytes became highly vulnerable to metabolic insults, such as glucose deprivation. In this study, we investigated whether H(2)O(2) production was associated with the increased vulnerability. Glucose deprivation for up to 8 hr did not change the intracellular level of H(2)O(2) in astrocytes. Treatment with lipopolysaccharide plus interferon-gamma for 48 hr evoked astroglial H(2)O(2) production; however, no apparent death or injury was observed in immunostimulated astrocytes. Glucose deprivation after 48 hr of immunostimulation markedly increased H(2)O(2) level, depleted adenosine triphosphate (ATP), and enhanced lactate dehydrogenase (LDH) release. The ATP depletion and LDH release were in part prevented by catalase, mannitol, and N-acetyl-L-cysteine. The enhanced level of H(2)O(2) in glucose-deprived immunostimulated astrocytes appeared to be secondary to the depletion of reduced glutathione. 4-(2-Aminoethyl)bebzenesulfonyl fluoride (AEBSF), an inhibitor of NADPH oxidase, reduced H(2)O(2) level and LDH release in glucose-deprived immunostimulated astrocytes. H(2)O(2), either endogenously produced or exogenously added, depolarized mitochondrial transmembrane potential in glucose-deprived astrocytes, leading to their ATP depletion and death. The present results strongly indicate that glucose deprivation causes deterioration of immunostimulated astrocytes by increasing the intracellular concentration of H(2)O(2).
Department of Pharmacology, College of Pharmacy, Seoul National University, Seoul, Republic of Korea.
Ji Woong
JW
Choi
Chan Young
CY
Shin
Byoung Kwon
BK
Yoo
Min Sik
MS
Choi
Woo Jong
WJ
Lee
Byoung Hee
BH
Han
Won-Ki
WK
Kim
Hyoung-Chun
HC
Kim
Kwang Ho
KH
Ko
D000255:Adenosine Triphosphate / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D005947:Glucose / Q000172:deficiency* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007114:Immunization; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D016877:Oxidants / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D008070:Lipopolysaccharides; D016877:Oxidants; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D005947:Glucose