Expression and regulation of latent TGF-beta binding protein-1 transcripts and their splice variants in human glomerular endothelial cells.
Latent transforming growth factor (TGF)-beta-binding protein (LTBP) is required for the assembly, secretion, matrix association, and activation of latent TGF-beta complex. To elucidate the cell specific expression of the genes of LTBP-1 and their splice variants and the factors that regulate the gene expression, we cultured primary human glomerular endothelial cells (HGEC) under different conditions. Basal expression of LTBP-1 mRNA was suppressed in HGEC compared to WI-38 human embryonic lung fibroblasts. High glucose, H(2)O(2), and TGF-beta1 upregulated and vascular endothelial growth factor (VEGF) further downregulated LTBP-1 mRNA in HGEC. RT-PCR with a primer set for LTBP-1S produced many clones but no clone was gained with a primer set for LTBP-1L. Of 12 clones selected randomly, Sca I mapping and DNA sequencing revealed that only one was LTBP-1S and all the others were LTBP-1Sdelta53. TGF-beta1, but not high glucose, H(2)O(2) or VEGF, tended to increase LTBP-1Sdelta53 mRNA. In conclusion, HGEC express LTBP-1 mRNA which is suppressed at basal state but upregulated by high glucose, H(2)O(2), and TGF-beta1 and downregulated by VEGF. Major splice variant of LTBP-1 in HGEC was LTBP-1S 53. Modification of LTBP-1S 53 gene in HGEC may abrogate fibrotic action of TGF-beta1 but this requires confirmation.
Kwak
Joon Hyeok
JH
Hyonam Kidney Laboratory, Soon Chun Hyang University, Korea.
Woo
Ji Su
JS
Shin
Kunyoo
K
Kim
Hee Joon
HJ
Jeong
Hoe Su
HS
Han
Dong Cheol
DC
Kim
Sung Il
SI
Park
Choon Sik
CS
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D007678:Kidney Glomerulus / Q000166:cytology; D053779:Latent TGF-beta Binding Proteins; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
D047908:Intracellular Signaling Peptides and Proteins; C509032:LTBP1 protein, human; D053779:Latent TGF-beta Binding Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D006861:Hydrogen Peroxide; D005947:Glucose