[Hyperlipidemia induced by high fat diet ingestion activates TGF-beta/Smad signaling pathway in the kidney of diabetic rats].
OBJECTIVE
To investigate the effect of diet-induced hyperlipidemia on TGF-beta/Smad signaling pathway in the kidney of diabetic rats, and to explore the mechanism by which hyperlipidemia leads to renal injury in diabetes.


METHODS
Diabetic rats and non-diabetic rats were fed with normal fat diet and high fat diet for 16 weeks, respectively. The expressions of TGF-beta1, TbetaRII, and Col-IV mRNA in the renal cortex were examined by reverse transcriptase-PCR,TbetaRII and p-Smad staining in glomerular cells were detected by immunohistochemical staining, and the expression of TGF-beta1 and Col-IV protein was determined by Western blot.


RESULTS
Diet-induced hyperlipidemia up-regulated the levels of TGF-beta1, TbetaRII, p-Smad, and Col-IV protein and mRNA in the renal cortex of diabetic rats compared with those of non-diabetic rats. However, feeding high fat diet to non-diabetic rats had no influence on the expression of TGF-beta1, TbetaRII, p-Smad2, and Col-IV in the renal cortex.


CONCLUSIONS
Hyperlipidemia induced by high fat diet ingestion leads to renal injury in diabetic rats through activating TGF-beta1 /Smad signaling pathway.
Chen
Zhou-xiong
ZX
Department of Endocrinology, Xiangya Hospital, Central South University, Changsha 410008, China.
Xie
Xiao-yun
XY
Yu
Ri-chen
RC
Zhang
Jun
J
Lei
Min-xiang
MX
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000378:metabolism*; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006949:Hyperlipidemias / Q000150:complications / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D051785:Smad Proteins / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
D004041:Dietary Fats; D051785:Smad Proteins; D053773:Transforming Growth Factor beta1