|
|
||||||||
1 From the Departments of Ophthalmology and 2 Cell Biology, University of Oklahoma Health Sciences Center; 3 Dean A. McGee Eye Institute, Oklahoma City; and 4 Department of Neurobiology, 5 Jules Stein Eye Institute, and 6 Brain Research Institute, University of California, Los Angeles.
PURPOSE. Humans with retinitis pigmentosa and dogs with progressive rodcone degeneration (prcd) have lower than normal blood levels of long-chain polyunsaturated fatty acids, including docosahexaenoic acid (DHA), the major fatty acid found in retinal rod outer segments (ROS). In addition, prcd-affected dogs have lower levels of DHA in their ROS than control animals. The present study was designed to determine whether mice that are heterozygous for the rds mutation and transgenic mice heterozygous for a specific rds/peripherin mutation (P216L) have lower DHA levels in their ROS and other tissues than do control mice.
METHODS. Wild-type (rds+/+) mice, mice with the rds-/- (null) and rds+/- mutations, and mice with the P216L rds/peripherin mutation on the rds+/- background were maintained in the vivarium under identical husbandry conditions, and tissues were removed from each group for analysis at approximately 2 months of age. Fatty acid compositions of total lipids from plasma, red blood cells, liver, and ROS were determined by gasliquid chromatography. ROS purity from each group was determined by SDS-PAGE with silver staining. The morphologic status of retinas representing each genotype was analyzed by light and electron microscopy.
RESULTS. There was no difference between rds+/-, P216L on rds+/-, and rds+/+ (control) animals in the fatty acid composition of plasma, expressed as relative mole percent or as nanomoles fatty acid per milliliter of plasma. Small but statistically significant differences were found in 18:0 and C-22 polyunsaturated fatty acids of red blood cells. In the liver, the control animals had higher levels of 20:4n-6. In contrast, the ROS of control animals had levels of DHA that were 1.4 times that of ROS from either rds+/- or P216L on rds+/- mice of the same age. The reduction in DHA was not accompanied by an increase in 22:5n-6, which always occurs in neural tissues of animals deprived of n-3 fatty acids. SDS-PAGE of the three ROS membrane preparations showed that they were of identical purity.
CONCLUSIONS. Mice heterozygous for the spontaneous rds/peripherin mutation or mice carrying the P216L mutation on this heterozygous background have a statistically significant reduction of DHA in their ROS membranes. The authors propose that reduction in DHA is an adaptive response to metabolic stress caused by the mutation.
This article has been cited by other articles:
![]() |
M. Tanito, R. S. Brush, M. H. Elliott, L. D. Wicker, K. R. Henry, and R. E. Anderson High levels of retinal membrane docosahexaenoic acid increase susceptibility to stress-induced degeneration J. Lipid Res., May 1, 2009; 50(5): 807 - 819. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Tanito, M. H. Elliott, Y. Kotake, and R. E. Anderson Protein Modifications by 4-Hydroxynonenal and 4-Hydroxyhexenal in Light-Exposed Rat Retina Invest. Ophthalmol. Vis. Sci., October 1, 2005; 46(10): 3859 - 3868. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Chen, A. Rattner, and J. Nathans The Rod Photoreceptor-Specific Nuclear Receptor Nr2e3 Represses Transcription of Multiple Cone-Specific Genes J. Neurosci., January 5, 2005; 25(1): 118 - 129. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. L. Berson, B. Rosner, M. A. Sandberg, C. Weigel-DiFranco, A. Moser, R. J. Brockhurst, K. C. Hayes, C. A. Johnson, E. J. Anderson, A. R. Gaudio, et al. Further Evaluation of Docosahexaenoic Acid in Patients With Retinitis Pigmentosa Receiving Vitamin A Treatment: Subgroup Analyses Arch Ophthalmol, September 1, 2004; 122(9): 1306 - 1314. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. K. Mukherjee, V. L. Marcheselli, C. N. Serhan, and N. G. Bazan From The Cover: Neuroprotectin D1: A docosahexaenoic acid-derived docosatriene protects human retinal pigment epithelial cells from oxidative stress PNAS, June 1, 2004; 101(22): 8491 - 8496. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |