[Interventional effects of emodin on transforming growth factor-beta1/integrin-linked kinase signal way in interleukin-1beta-induced transdifferentiation of rat tubular epithelial-myofibroblasts].
OBJECTIVE
To study the effects of transforming growth factor-beta1/integrin-linked kinase (TGF-beta1/ILK) signal way in interleukin-1beta (IL-1beta)-induced rat tubular epithelial-myofibroblast transdifferentiation (TEMT), and to investigate whether emodin inhibits IL-1beta-induced TEMT through the TGF-beta1/ILK signal way-dependent mechanism.


METHODS
Normal rat kidney epithelial cell line (NRK52E) was used in this study. NRK52E cells were divided into blank control group, emodin control group, IL-1beta-induced group, emodin-inhibited group, SB431542 (TGF-beta 1 type I receptor blocker)-inhibited group, emodin plus SB431542-inhibited group, emodin-pretreated group and emodin-reversed group. After 48-hour culture, morphological changes of the NRK52E cells were observed by an inverted phase contrast microscope. The expressions of alpha-smooth muscle actin (alpha-SMA) and E-cadherin were detected by two-color immunohistochemical staining, while the expressions of TGF-beta1 and ILK were detected by one-color immunohistochemical staining. We also performed the imaging analysis to quantitatively analyze the result of the immunohistochemical staining. The secretion of fibronectin (FN) was analyzed by enzyme-linked immunosorbent assay.


RESULTS
Compared with the blank control group, IL-1beta might induce TEMT, which was showed in increasing expression of alpha-SMA, increasing secreting of FN and decreasing expression of E-cadherin, and at the same time the expressions of TGF-beta1 and ILK were enhanced (P<0.05). Emodin might inhibit all of those changes induced by IL-1beta (P<0.05). When TGF-beta1 signal way was intercepted, IL-1beta induced-TEMT was suppressed and the expression of ILK was decreased, however, there was no significant difference in expression of TGF-beta1 between the SB431542 group and the IL-1beta-induced group. Compared with emodin-inhibited group, emodin-pretreatment could not prevent IL-1beta induced-TEMT in a certain extent, but emodin could not revert IL-1beta-induced TEMT. Spearman correlation analysis showed that TGF-beta1 expression had positive correlation with expressions of alpha-SMA, FN, ILK and negative correlation with E-cadherin expression, and the expression of ILK was positively correlated with the expressions of alpha-SMA and FN and negatively correlated with E-cadherin expression.


CONCLUSIONS
IL-1beta induces TEMT partly depending on TGF-beta1/ILK signal way, partly via which emodin inhibits the TEMT induced by IL-1beta.
Chen
Ting-fang
TF
Department of Nephrology, Luzhou Medical College, Luzhou, Sichuan Province 646000, China.
Chen
Ming
M
Qin
Jian-hua
JH
Wang
Ming-yong
MY
D000199:Actins / Q000378:metabolism; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D054338:Cell Transdifferentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004642:Emodin / Q000494:pharmacology*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D007684:Kidney Tubules / Q000166:cytology; D058628:Myofibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D000099200:Scaffold Protein ILK
D000199:Actins; D015820:Cadherins; D004642:Emodin; D053583:Interleukin-1beta; D017346:Protein Serine-Threonine Kinases; D053773:Transforming Growth Factor beta1; D000099200:Scaffold Protein ILK; C508962:Tgfb1 protein, rat; C498862:Acta2 protein, rat