title: Inhibition of apoptotic signalling in spermine-treated vascular smooth muscle cells by a novel glutathione precursor.
abstract: CKD (chronic kidney disease) is a public health problem, mediated by haemodynamic and non-haemodynamic events including oxidative stress. We investigated the effect of two GSH (glutathione) precursors, NAC (N-acetylcysteine) and cystine as the physiological carrier of cysteine in GSH with added selenomethionine (F1) in preventing spermine (uraemic toxin)-induced apoptosis in cultured human aortic VSMC (vascular smooth muscle cells). VSMCs exposed to spermine (15 microM) with or without antioxidants (doses 50, 100, 200 and 500 microg/ml) were assessed for apoptosis, JNK (c-Jun-NH2-terminal kinase) activation and iNOS (inducible nitric oxide synthase) induction and activation of intrinsic pathway signalling. Spermine exposure resulted in activation of JNK and iNOS induction and apoptosis. NAC and F1 (dose range 50-500 microg/ml) attenuated spermine-induced acceleration of VSMC apoptosis but only F1 (at 200 and 500 microg/ml) maintained spermine-induced apoptosis at control levels. Spermine-induced JNK activation was prevented by 200 microg/ml of both NAC and F1, while iNOS induction was blocked only by F1. Notably, the adverse effects of spermine on BAX/BCL-2 ratio, cytochrome c release and caspase activation was fully attenuated by F1. In conclusion, F1 was more effective than NAC in preventing spermine-induced apoptosis and downstream changes in related signal transduction pathways in VSMCs. Further studies are needed to examine the effect of these compounds in preventing CKD-associated vascular disease.
authors.affiliation: Department of Medicine, Charles Drew University, Los Angeles, CA 90059, USA. insinhah@cdrewu.edu
authors.forename: Indrani
authors.initials: I
authors.lastname: Sinha-Hikim
authors.forename: Ruoqing
authors.initials: R
authors.lastname: Shen
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Kovacheva
authors.forename: Albert
authors.initials: A
authors.lastname: Crum
authors.forename: Nosratola D
authors.initials: ND
authors.lastname: Vaziri
authors.forename: Keith C
authors.initials: KC
authors.lastname: Norris
mesh_terms: D000111:Acetylcysteine / Q000378:metabolism / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D003553:Cystine / Q000378:metabolism / Q000494:pharmacology*; D004789:Enzyme Activation; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D018384:Oxidative Stress; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects*; D013096:Spermine / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000975:Antioxidants; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D013096:Spermine; D003553:Cystine; D052247:Nitric Oxide Synthase Type II; D048031:JNK Mitogen-Activated Protein Kinases; D005978:Glutathione; D000111:Acetylcysteine