High glucose inhibits gene expression of tyrosyl-tRNA synthetase in osteoblast cells.
It has been suggested that bone metabolism disorders are one of the major complications of diabetes mellitus. However, the exact mechanisms as to how diabetes affects bone metabolism are yet to be determined. In the present study, we have searched for high glucose regulated genes in osteoblast-like UMR-106 cells. UMR-106 cells were treated with normal glucose (5.5 mM), high glucose (16.5 mM or 30.5 mM) and mannitol (16.5 mM) as a hyperosmotic control. Following the isolation of total RNA, GeneFishing differential display-PCR (DDPCR) was carried out and followed by cloning, sequencing and searching in a gene bank data base to identify the high glucose induced gene(s). Through the DD-PCR technique which employs Annealing Control Primer, or ACP, it has been found that expression of a PCR product was significantly decreased by high glucose treatment: it was identified as tyrosyl-tRNA synthetase. Furthermore, reverse transcriptase PCR analysis confirmed that high glucose significantly decreases mRNA expression of tyrosyl-tRNA synthetase, whereas mannitol treatment does not cause any change in such expression. These results suggest that high glucose may play a significant role in the protein synthesis process of osteoblast cells by decreasing expression of tyrosyl-tRNA synthetase. In a Western blot analysis, the protein expression of tyrosyl-tRNA synthetase was also decreased by high glucose treatment. Taken together, these results suggest that high glucose could affect bone metabolism by regulating the expression of tyrosyl-tRNA synthetase genes.
Department of Pharmacology and Metabolic Diseases Research Laboratoy, School of Dentistry, Kyung Hee University, Seoul, Korea.
Jun Hoe
JH
Kim
Yun-Young
YY
Kim
Sung-Jin
SJ
Kim
D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014448:Tyrosine-tRNA Ligase / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D012333:RNA, Messenger; D008353:Mannitol; D014448:Tyrosine-tRNA Ligase; D005947:Glucose