The up-regulation of angiotensin II receptor type 1 and connective tissue growth factor are involved in high-glucose-induced fibronectin production by cultured human dermal fibroblasts.
BACKGROUND
The expansion of extracellular matrix in diabetes occur in many tissues, including skin, but the underlying mechanisms are poorly understood. We were interested to study whether the activation of angiotensin II/receptor type 1 pathway with the consequent involvement of CTGF may be the possible cause of high-glucose-induced matrix abnormalities in cultured dermal fibroblasts.


OBJECTIVE
We aimed to investigate the effect of high glucose on the generation of angiotensin II and the expression of angiotensin II receptors, and on the expression of CTGF mediating the fibronectin production in cultured human dermal fibroblasts.


METHODS
Cell culturing, ELISA, semi-quantitative RT-PCR, Western blotting.


RESULTS
High glucose treatment of cultured dermal fibroblasts led to: (1) the angiotensin II receptor type 1 was up-regulated at the level of mRNA and protein, unlike the receptor type 2; (2) the generation of angiotensin II and the mRNA expression of all components of the local renin-angiotensin system were not altered; (3) the mRNA and protein expression of CTGF was up-regulated, and this effect was cancelled by losartan; (4) the fibronectin production was increased, also was cancelled by losartan, while an anti-CTGF-neutralizing antibody only partly reduced it; (5) TGFbeta1 expression, the secretion of total and active TGFbeta1 were not changed; (6) the hyperosmotic action of high glucose had no effect.


CONCLUSIONS
The up-regulation of angiotensin II receptor type 1 and the consequent increase of CTGF expression, independently of TGFbeta1, participate in high-glucose-induced fibronectin production in cultured human dermal fibroblasts.
Yevdokimova
Natalia
N
Department of Molecular Immunology, Institute of Biochemistry, National Academy of Sciences of Ukraine, 9 Leontovich Str., 01030 Kyiv, Ukraine. berezan@mathber.carrier.kiev.ua
Podpryatov
Sergij
S
D000328:Adult; D002452:Cell Count; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D017077:Culture Media, Conditioned / Q000494:pharmacology; D020405:Dermis / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005353:Fibronectins / Q000378:metabolism*; D005355:Fibrosis; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
C526317:CCN2 protein, human; D017077:Culture Media, Conditioned; D005353:Fibronectins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D053773:Transforming Growth Factor beta1; D055513:Connective Tissue Growth Factor; D005947:Glucose