Evaluation of lens epithelial cell differentiation by quantitation of MP26 mRNA relative to gamma-crystallin mRNA in initiation of galactose cataracts in the rat.
It is well established that in response to feeding of galactose to four-week-old rats cataracts develop (Unakar, Genyea, Reddan & Reddy, Exp. Eye Res. 26, 123-33, 1978). Initiation of cataracts leads to epithelial cell proliferation. In the lens, the main intrinsic membrane protein, MP26, is recognized as a fiber cell-specific gene product, and gamma-crystallin is found in terminally differentiated fiber cells. By Northern blot analysis we quantitated the MP26 and gamma-crystallin mRNAs found in the lens at various times spanning from 0 to 96 hr on galactose. We find that by 24 hr, MP26 mRNA, as well as gamma-crystallin mRNA, increased significantly above the zero time levels. The data was also confirmed by in situ hybridization of various lens sections to both gamma-crystallin and MP26 35S-labeled antisense RNA probes. As expected, at later periods beyond 24 hr, the levels of gamma-crystallin and MP26 mRNAs dropped to below the control levels. The initial increase in MP26 and gamma-crystallin mRNAs lead us to conclude that initiation of galactose cataracts appears to support, although for a short time period, both epithelial cell elongation and fiber cell differentiation.
Wen
Y
Y
Doheny Eye Institute, Los Angeles, CA 90033.
Unakar
N J
NJ
Bekhor
I
I
D000818:Animals; D020346:Aquaporins; D015152:Blotting, Northern; D002386:Cataract / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D003459:Crystallins / Q000096:biosynthesis*; D005136:Eye Proteins / Q000096:biosynthesis; D005260:Female; D005690:Galactose; D007908:Lens, Crystalline / Q000378:metabolism / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D020346:Aquaporins; D003459:Crystallins; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; C030328:aquaporin 0; D005690:Galactose