Quantification of glomerular TGF-beta 1 mRNA in patients with diabetes mellitus.
Transforming growth factor-beta 1 (TGF-beta 1) is a primary determinant of the mesangial expansion observed in diabetic nephropathy. In this study, we quantitated the levels of intraglomerular TGF-beta 1 mRNA in patients with diabetes mellitus using a competitive polymerase chain reaction (PCR) method. Renal biopsy specimens were obtained from 29 patients with non-insulin-dependent diabetes mellitus. Total RNA was extracted from the glomeruli and reverse transcribed into cDNA with reverse transcriptase. To prepare samples containing identical amounts of beta-actin cDNA (8 pg), we performed competitive PCR by co-amplifying mutant templates of beta-actin with a unique EcoRI site. We also used this competitive PCR method to measure TGF-beta 1 cDNA by co-amplifying mutant templates of TGF-beta 1. We observed higher expression of TGF-beta 1 mRNA in glomeruli of patients with diabetic nephropathy as compared with normal glomeruli. Intraglomerular TGF-beta 1 mRNA was elevated, even in the early stage of diabetic nephropathy. Moreover, levels of intraglomerular TGF-beta 1 mRNA correlated with values of HbA1c. These data suggest that hyperglycemia induces intraglomerular TGF-beta 1 mRNA expression in vivo, and that TGF-beta 1 overproduction may be associated with the progression of diabetic nephropathy.
Iwano
M
M
First Department of Internal Medicine, Nara Medical University, Japan.
Kubo
A
A
Nishino
T
T
Sato
H
H
Nishioka
H
H
Akai
Y
Y
Kurioka
H
H
Fujii
Y
Y
Kanauchi
M
M
Shiiki
H
H
Dohi
K
K
D000368:Aged; D001483:Base Sequence; D001706:Biopsy; D015139:Blotting, Southern; D003094:Collagen / Q000235:genetics; D003920:Diabetes Mellitus / Q000235:genetics* / Q000378:metabolism; D003929:Diabetic Neuropathies / Q000235:genetics* / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007678:Kidney Glomerulus / Q000737:chemistry* / Q000473:pathology; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000235:genetics*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D003094:Collagen