Profile of messenger RNA decay in the Emory mouse lens in cataractogenesis and in aging.
The Emory mouse is presumed to be a model for studies on human senile cataracts. The cataract develops in 5-8 months after birth, and it does not appear to have an osmotic component. To date, no specific metabolic lesion has been uncovered as a probable cause to this cataract. Several studies have shown that the Emory mouse undergoes accelerated aging changes, possibly leading to development of senile-type cataracts. In this study we quantitated changes that might occur in the population of various mRNAs for proteins presumed to be essential for lens transparency, and for proteins that may contribute to development of cataracts. By Northern blot hybridization analysis we quantitated the mRNAs for: alpha A-crystallin, beta B1-crystallin, gamma-crystallin, the main lens intrinsic membrane protein, MP26, and aldose reductase; all in lenses of Emory mouse early cataract strain (EMEC), and of an age-matched cataract resistant strain (CR). These measurements were done in increments of 1 month over a 6-month period, then at both 9 and 12 months. The results show that all of these mRNAs decrease with age and with development of cataracts; although in some cases the initial concentrations at 1 month appear to be lower in the EMEC than in the CR strain. The most dramatic change occurred with the MP26 mRNA. In the CR strain, MP26 mRNA maintained its high concentration for a period of about 6 months before it began its decline to the 12 month level (about 25% of the 1 month level).(ABSTRACT TRUNCATED AT 250 WORDS)
Shi
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Laboratory for Molecular Genetics, University of Southern California School of Dentistry, Los Angeles.
Bekhor
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D000375:Aging / Q000378:metabolism; D000449:Aldehyde Reductase / Q000096:biosynthesis; D000818:Animals; D020346:Aquaporins; D015152:Blotting, Northern; D002386:Cataract / Q000235:genetics* / Q000378:metabolism; D003459:Crystallins / Q000096:biosynthesis; D005136:Eye Proteins / Q000096:biosynthesis; D007908:Lens, Crystalline / Q000378:metabolism*; D008562:Membrane Glycoproteins; D051379:Mice; D008815:Mice, Inbred Strains; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism*; D013997:Time Factors
D020346:Aquaporins; D003459:Crystallins; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; C030328:aquaporin 0; D000449:Aldehyde Reductase