Nitric oxide differentially regulates the gene expression of caspase genes but not some autophagic genes.
Nitric oxide (NO) is fundamentally important molecule which produces a wide range of cellular effects with the most poorly understood one being alteration in the sensitivity to cell death. The objective of this study was to test the hypothesis that NO would differentially affect caspase or autophagy gene expression in a manner that might account for the disparate actions of NO to either enhance or protect against cell death. Neonatal mouse cardiomyocytes in culture were treated with the NO donor SIN-1 (3-morpholinosydnonimine hydrochloride) for up to 20 h. RNA was collected, after either 2, 4 or 20 h, labeled and hybridized to cDNA microarray slides The concentration of SIN-1 was selected after concentration response studies of SIN-1 on cell viability, assessed by the MTT assay. The cDNA microarrays were used that contained the mouse genome version 2.0 with genes for enzymes crucial to apoptosis, namely caspases-1, -2, -3, -6, -7, -8, -9, -11, -12 and -14, as well as for enzymes crucial to autophagy namely beclin-1, Apg5l and Apg12l. Considering the entire 20 h period, treatment with SIN-1 was associated with significant (p<0.05) changes in five caspases. In contrast, there were no changes in the three separate genes involved in autophagy. Time course experiments showed a consistent increase in caspase-8, -11 and -14, and a consistent decrease in caspase-1 and -6. Notably, caspase-1 showed a persistent and marked reduction so that after 20 h of treatment, caspase-1 was dramatically reduced, almost ten fold, to 0.14+/-0.11 of control. In conclusion, these results suggest that: (i) NO regulates the expression of genes involved in apoptotic but not some involved in autophagic cell death; (ii) the more recently discovered caspase-14 may have a role in the heart; (iii) NO-induced alteration of different caspases may explain the ability of NO to either enhance or protect against cell death depending on whether associated factors involve, respectively caspases-8, -11, and -14 or -1 and -6.
Rabkin
Simon W
SW
University of British Columbia, Room D410, 2733 Heather Street, Vancouver, BC, Canada V5Z 3J5. rabkin@interchange.ubc.ca
Klassen
Shaun S
SS
D000818:Animals; D000831:Animals, Newborn; D051017:Apoptosis Regulatory Proteins; D001343:Autophagy / Q000235:genetics*; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; D000071186:Beclin-1; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D011506:Proteins / Q000235:genetics / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; C491971:Atg12 protein, mouse; C495773:Atg5 protein, mouse; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; D000071186:Beclin-1; C115010:Becn1 protein, mouse; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D020030:Nitric Oxide Donors; D011506:Proteins; D009569:Nitric Oxide; C002385:linsidomine; D008981:Molsidomine; D020169:Caspases