Demonstration of nuclear compartmentalization of glutathione in hepatocytes.
The intracellular distribution of glutathione (GSH) in cultured hepatocytes has been investigated by using the compound monochlorobimane (BmCl), which interacts specifically with GSH to form a highly fluorescent adduct. Image analysis of BmCl-labeled hepatocytes predominantly localized the fluorescence in the nucleus; the nuclear/cytoplasmic concentration gradient was approximately three. This concentration gradient was collapsed by treatment of the cells with ATP-depleting agents. The uneven distribution of BmCl fluorescence was not attributable to (i) nonspecific interaction of BmCl with protein sulfhydryl groups, (ii) any selective nuclear localization of the GSH transferase(s) catalyzing formation of the GSH-BmCl conjugate, or (iii) any apparent alterations in cell morphology from culture conditions, suggesting that this distribution did, indeed, reflect a nuclear compartmentalization of GSH. That the nuclear pool of GSH was found more resistant to depletion by several agents than the cytoplasmic pool supports the assumption that GSH is essential in protecting DNA and other nuclear structures from chemical injury.
Bellomo
G
G
Dipartimento di Medicina Interna e Terapia Medica, University of Pavia, Italy.
Vairetti
M
M
Stivala
L
L
Mirabelli
F
F
Richelmi
P
P
Orrenius
S
S
D000818:Animals; D001643:Bridged Bicyclo Compounds; D019328:Buthionine Sulfoximine; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D005033:Ethylmaleimide / Q000494:pharmacology; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D005978:Glutathione / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008298:Maleates / Q000494:pharmacology; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D011720:Pyrazoles; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence / Q000379:methods; D013347:Subcellular Fractions / Q000378:metabolism; D014812:Vitamin K / Q000494:pharmacology
D001643:Bridged Bicyclo Compounds; D005456:Fluorescent Dyes; D008298:Maleates; D011720:Pyrazoles; D014812:Vitamin K; D008717:Methionine Sulfoximine; D019328:Buthionine Sulfoximine; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C059597:monochlorobimane; C014476:diethyl maleate; D005978:Glutathione; D016650:Fluorescein-5-isothiocyanate; D005033:Ethylmaleimide; C028381:monobromobimane