|
|
||||||||
CALL FOR PAPERS
Oxidative Stress
1Biochemistry Department, 4Veterinary and Biomedical Sciences Department, University of Nebraska, Lincoln, Nebraska 68588-0664; 3Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80220; 2University of Iowa Carver College of Medicine and Veterans Affairs Medical Center, Iowa City, Iowa 52242; and 5Departments of Medicine, Baylor College of Medicine, and Veterans Affairs Medical Center, Houston, Texas 77030
Submitted 16 January 2004 ; accepted in final form 11 March 2004
Elevated plasma levels of homocysteine are a risk factor for cardiovascular diseases, neural tube defects, and Alzheimer's disease. The transsulfuration pathway converts homocysteine to cysteine, and
50% of the cysteine in glutathione is derived from homocysteine in human liver cells, which suggests the hypothesis that defects in the transsulfuration pathway perturb redox homeostasis. To test this hypothesis, we examined a murine model for hyperhomocysteinemia in which the gene encoding the first enzyme in the transsulfuration pathway, cystathionine
-synthase (CBS), has been disrupted. Limited metabolite profiling and CBS expression studies in liver, kidney, and brain reveal tissue-specific differences in the response to Cbs disruption. Homozygous disruption of Cbs lowered cysteine concentration in all three organs. Glutathione concentration was diminished in liver and brain, thus affecting the redox buffering capacity in these organs, whereas the approximately twofold higher glutathione synthesis capacity in kidney helped preserve the glutathione pool size despite loss of the transsulfuration pathway in this organ. In contrast, disruption of a single Cbs allele elicited only minor redox perturbations. Furthermore, the Cbs+/ genotype did not confer a significant disadvantage compared with the Cbs+/+ genotype in hepatocytes challenged by oxidative stress from exposure to tertiary butylhydroperoxide. These studies provide evidence that homozygous disruption of Cbs perturbs redox homeostasis and reduces cysteine levels, raising the possibility that these changes may be important in the etiology of the clinical manifestations of CBS deficiency.
cystathionine
-synthase; homocystinuria; cysteine; glutathione
This article has been cited by other articles:
![]() |
D. C. Cabelof, H. V. Patel, Q. Chen, H. van Remmen, L. H. Matherly, Y. Ge, and J. W. Taub Mutational spectrum at GATA1 provides insights into mutagenesis and leukemogenesis in Down syndrome Blood, September 24, 2009; 114(13): 2753 - 2763. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Li, E. Arning, C. Liu, V. Vitvitsky, C. Hernandez, R. Banerjee, T. Bottiglieri, and J. D. Lin Regulation of homocysteine homeostasis through the transcriptional coactivator PGC-1{alpha} Am J Physiol Endocrinol Metab, March 1, 2009; 296(3): E543 - E548. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Dayal and S. R. Lentz Murine Models of Hyperhomocysteinemia and Their Vascular Phenotypes Arterioscler Thromb Vasc Biol, September 1, 2008; 28(9): 1596 - 1605. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Akahoshi, C. Kobayashi, Y. Ishizaki, T. Izumi, T. Himi, M. Suematsu, and I. Ishii Genetic background conversion ameliorates semi-lethality and permits behavioral analyses in cystathionine {beta}-synthase-deficient mice, an animal model for hyperhomocysteinemia Hum. Mol. Genet., July 1, 2008; 17(13): 1994 - 2005. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Vitvitsky, A. Prudova, S. Stabler, S. Dayal, S. R. Lentz, and R. Banerjee Testosterone regulation of renal cystathionine beta-synthase: implications for sex-dependent differences in plasma homocysteine levels Am J Physiol Renal Physiol, August 1, 2007; 293(2): F594 - F600. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Ernest, A. Hosack, W. E. O'Brien, D. S. Rosenblatt, and J. H. Nadeau Homocysteine levels in A/J and C57BL/6J mice: genetic, diet, gender, and parental effects Physiol Genomics, May 11, 2005; 21(3): 404 - 410. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |