Regional expression of disease-related genes in human and monkey retina.
OBJECTIVE
Although specific genes play a role in regional retinal disease, the correlation of regional gene expression in the disease-affected site has not been previously ascertained. Non-human primates are widely used in models of human retinal function and are theorized to have identical (to human) patterns of expression, but no correlation between primate and human regional retinal gene expression has ever been performed. We wanted to evaluate the pattern of regional gene expression for a number of genes whose dysfunctions are known to selectively affect specific regions of the human retina, and to determine whether patterns of regional gene expression in nonhuman primates correlate with the human.


METHODS
Human and rhesus monkey eyes were dissected into retina, retinal pigment epithelium (RPE)/choroid and isolated RPE. Retinal regions were dissected, total RNA was isolated and northern analysis performed. Complementary DNA (cDNA) probes were prepared from genes associated with regional retinal disease. These genes are: rod opsin, the alpha-subunit of rod phosphodiesterase, RDS-peripherin, rod outer membrane (ROM) protein, ornithine aminotransferase (OAT), choroideremia gene product (CHM), tissue specific inhibitor of metalloproteinases-3 (TIMP-3), and red/green photoreceptor pigment protein. We also compared expression of Norrie disease product (NDP), a gene whose mutation is known to globally affect the retina.


RESULTS
Rod-specific mRNA expression is highest in the retinal midperiphery, and cone-specific mRNA levels were highest in total RNA from the cone-dominant fovea. mRNA levels for genes coding for proteins expressed in both rod- and cone photoreceptors (RDS-peripherin and ROM-1) are also highest in total RNA from the retinal midperiphery. Regional mRNA levels of CHM and OAT do not directly correlate with their patterns of disease expression. NDP mRNA expression was equivalent in both fovea and midperipheral retina total RNA. Patterns of gene expression were qualitatively similar for both human and rhesus monkey retina.


CONCLUSIONS
Regional retinal gene expression is an important factor in regional disease. However, for genes not solely expressed by a single photoreceptor subtype, other factors, such as regional metabolic differences, intra- and intercellular interactions, are also likely to be important in predisposing a single retinal region to disease. The pattern of neural retina OAT mRNA expression may have important implications in determining the appropriate tissue approach in gene therapy for gyrate atrophy. Regional retinal gene expression likely plays a significant, but nonexclusive role in the development of regional retinal disease.
Bernstein
S L
SL
Laboratory of Molecular Research, Department of Ophthalmology, University of Maryland, Baltimore, MD 21201, USA. slbernst@umabnet.ab.umd.edu
Wong
P
P
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019883:Alkyl and Aryl Transferases; D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000378:metabolism; D002648:Child; D002829:Choroid / Q000378:metabolism; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; D005136:Eye Proteins / Q000378:metabolism; D005584:Fovea Centralis / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008253:Macaca mulatta; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009953:Ornithine-Oxo-Acid Transaminase / Q000378:metabolism; D064531:Peripherins; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000378:metabolism*; D012162:Retinal Degeneration / Q000235:genetics / Q000378:metabolism*; D012168:Retinal Pigments / Q000378:metabolism; D017299:Rod Opsins / Q000378:metabolism; D059470:Tetraspanins; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000378:metabolism; D020691:rab GTP-Binding Proteins
D048868:Adaptor Proteins, Signal Transducing; C081787:CHM protein, human; D002352:Carrier Proteins; D005136:Eye Proteins; D007381:Intermediate Filament Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C081848:NDP protein, human; D009419:Nerve Tissue Proteins; C578994:PRPH protein, human; C578997:PRPH2 protein, human; D064531:Peripherins; D012333:RNA, Messenger; C513106:ROM1 protein, human; D012168:Retinal Pigments; D017299:Rod Opsins; D059470:Tetraspanins; D019717:Tissue Inhibitor of Metalloproteinase-3; D019883:Alkyl and Aryl Transferases; D009953:Ornithine-Oxo-Acid Transaminase; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C096885:PDE6C protein, human; D020691:rab GTP-Binding Proteins