title: Astrocytes produce the antiinflammatory and neuroprotective agent hydrogen sulfide.
abstract: Hydrogen sulfide (H(2)S) is an essential physiological product in brain. We investigated the expression of cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CGL), the two H(2)S synthesizing enzymes, in human cell lines and in human brain. Only astrocytes were strongly immunostained for CBS. Cultured astrocytes synthesized H(2)S at the rate of 15.06 micromol/g protein/h, which was 7.57 fold higher than microglial cells, 10.27 fold higher than SH-SY5Y cells and 11.32 fold higher than NT-2 cells. The H(2)S synthesis in all these cell types was inhibited by the CBS inhibitor hydroxylamine, but not by the CGL inhibitor propargylglycine (PAG). Synthesis of H(2)S by HUVEC cells was inhibited by PAG but not by hydroxylamine indicating that these vascular cells utilize CGL but not CBS. Inflammatory activation of microglia and astrocytes caused induction of NFkappaB, release of the inflammatory mediators TNFalpha, IL-6 and nitrite ions, down-regulation of CBS, and down-regulation of H(2)S synthesis. There was no effect of such treatment on HUVEC cells. The effects were partially reversed by pretreatment of cells with the H(2)S releasing agent NaSH. These data indicate that H(2)S is an endogenous antiinflammatory and neuroprotective agent under the synthetic control of CBS. H(2)S releasing drugs may have therapeutic potential in neurodegenerative disorders of aging such as Alzheimer disease and Parkinson disease.
authors.affiliation: Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada.
authors.forename: Moonhee
authors.initials: M
authors.lastname: Lee
authors.forename: Claudia
authors.initials: C
authors.lastname: Schwab
authors.forename: Sheng
authors.initials: S
authors.lastname: Yu
authors.forename: Edith
authors.initials: E
authors.lastname: McGeer
authors.forename: Patrick L
authors.initials: PL
authors.lastname: McGeer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000480:Alkynes / Q000494:pharmacology; D001253:Astrocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D001921:Brain / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D003541:Cystathionine beta-Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D019811:Hydroxylamine / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D017628:Microglia / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D018696:Neuroprotective Agents / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000480:Alkynes; D004791:Enzyme Inhibitors; C508600:IL6 protein, human; D015850:Interleukin-6; D016328:NF-kappa B; D018696:Neuroprotective Agents; D009573:Nitrites; D014409:Tumor Necrosis Factor-alpha; D019811:Hydroxylamine; C009055:propargylglycine; D003541:Cystathionine beta-Synthase; D003542:Cystathionine gamma-Lyase; D005998:Glycine; D006862:Hydrogen Sulfide