TGF-beta1 and CTGF mRNAs are correlated with urinary protein level in IgA nephropathy.
The degree of tubulointerstitial fibrosis is a poor prognostic indicator in IgA nephropathy (IgAN). Recently, connective tissue growth factor (CTGF) was observed to be strongly up-regulated in human proliferative and fibrogenic diseases. Renal biopsy specimens were obtained from the 20 patients with IgAN. Based on a previously reported study (MDRD study), all cases were categorized into 2 groups. Group A included patients with urinary protein (u-protein) <1.0 g/day, and group B, those with u-protein > or =1.0 g/day. Expressions of transforming growth factor beta1 (TGF-beta1) and CTGF mRNAs in tubular epithelial cells (TECs) were examined in all cases using rapid in situ hybridization (rISH). Significantly strong and diffuse expressions of TGF-beta1 and CTGF mRNAs were observed in proximal TECs in group B, while the expressions of these 2 mRNAs were weak in proximal TECs in group A and in glomerular resident cells in both groups. These results closely correlated with the degree of disorder in conventional pathohistological findings and clinical parameters except for u-protein level. The increase of u-protein level is one of the most important factors influencing the expression of TGF-beta1 and CTGF mRNAs in TECs. Therefore, the authors conclude that both u-protein level and expressions of these 2 mRNAs in TECs were significantly correlated with the degree of tubulointerstitial damage in IgAN.
Nonaka Takahashi
Sachiko
S
Division of Nephrology and Endocrinology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. nsachiko@med.nihon-u.ac.jp
Fujita
Takayuki
T
Takahashi
Teruyiki
T
Wada
Yuki
Y
Fuke
Yoshinobu
Y
Satomura
Atsushi
A
Matsumoto
Koichi
K
D055513:Connective Tissue Growth Factor; D005922:Glomerulonephritis, IGA / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D007684:Kidney Tubules / Q000378:metabolism; D011507:Proteinuria / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis*; D053773:Transforming Growth Factor beta1 / Q000235:genetics*
C526317:CCN2 protein, human; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D055513:Connective Tissue Growth Factor