Decreased expression of ribosomal proteins in human age-related cataract.
OBJECTIVE
To identify lens epithelial genes with altered expression levels in age-related human cataract.


METHODS
Epithelia from age-related cataracts and from normal lenses were microdissected and RNA was extracted. RNAs were compared for gene expression differences by RT-PCR differential display. Transcripts exhibiting altered levels of gene expression were cloned and identified by sequencing. The expression levels of identified clones were confirmed by semiquantitative RT-PCR with three separately isolated RNA preparations. Specific primers were designed and used to examine the mRNA levels of other genes important in protein synthesis.


RESULTS
Numerous transcripts exhibited altered levels of gene expression. One transcript exhibiting a decreased level of expression in cataract compared with normal lenses was identified as encoding ribosomal protein L21. Three additional ribosomal proteins, L15, L13a, and L7a, also exhibited decreased expression in cataract compared with normal human lenses. By contrast, the levels of elongation factor (EF)-1alpha1 and eucaryotic initiation factor (eIF)-4E remained unchanged.


CONCLUSIONS
The results provide evidence that human age-related cataract is associated with decreased expression of L21 and other ribosomal proteins. The results suggest that modulation of protein synthesis and/or other functions mediated by ribosomal proteins is associated with age-related cataract.
Zhang
WeiYan
W
The Department of Biology, West Virginia University, Morgantown, West Virginia 26506-6057, USA.
Hawse
John
J
Huang
QingLing
Q
Sheets
Nancy
N
Miller
Kevin M
KM
Horwitz
Joseph
J
Kantorow
Marc
M
D000368:Aged; D000375:Aging / Q000378:metabolism*; D001483:Base Sequence; D002386:Cataract / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005784:Gene Amplification; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D012269:Ribosomal Proteins; C060232:ribosomal protein L21; D012313:RNA