The effects of urokinase-type plasminogen activator (uPA) on cell proliferation and phenotypic transformation of rat mesangial cells induced by high glucose.
OBJECTIVE
To investigate the effects of urokinase-type plasminogen activator (uPA) on proliferation and phenotypic transformation of rat mesangial cells (MCs) under high glucose conditions and its possible signal transduction pathway.


METHODS
Rat MC were divided into 4 groups: the control group, the high glucose group, the high glucose and wortmannin group, and the high glucose and uPA group. MC proliferation in all groups was detected by the 3-(4,5-dimethylthiazol-)-2,5-diphenyltetrazolium bromide (MTT) method. MC cell cycle was analyzed by flow cytometry. Expression of cyclin dependent kinase 2 (CDK2), and activity of the signaling protein Akt in MC were detected by Western blot. Expression pattern and quantity of α-smooth muscle actin (α-SMA) in MC were examined using laser confocal microscopy. The expression of plasminogen activator inhibitor-1 (PAI-1), and collagen IV in renal tissues in rats was tested with immunohistochemistry and Western blotting methods.


RESULTS
Activation of Akt induced by high glucose can be reduced significantly by wortmannin and uPA. There was no obvious change in CDK2 protein expression in different groups (P>0.05). Expression of α-SMA in MC cytoplasm increased dramatically (P<0.01). Expression of α-SMA decreased significantly in the high glucose and wortmannin group and the high glucose and uPA group compared with that of the high glucose group (P<0.01). In diabetic rats, uPA down-regulated PAI-1 and collagen IV expression in mesangial matrix (P<0.05).


CONCLUSIONS
uPA antagonizes cell proliferation and phenotypic transformation of MCs induced by high glucose through inhibiting Akt signaling pathway.
Dept of Nephrology, Renmin Hospital of Wuhan University, P. R. C.. Electronic address: chenghui.116@163.com.
Hui
H
Cheng
Dept of Nephrology, Renmin Hospital of Wuhan University, P. R. C.
Cheng
C
Chen
Dept of Nephrology, Renmin Hospital of Wuhan University, P. R. C.
Siyuan
S
Wang
Dept of Nephrology, Renmin Hospital of Wuhan University, P. R. C.
Guohua
G
Ding
Dept of Nephrology, Renmin Hospital of Wuhan University, P. R. C.
Ming
M
Shi
D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects*; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology*; D008297:Male; D050527:Mesangial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018613:Microscopy, Confocal; D010641:Phenotype; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D013549:Sweetening Agents / Q000494:pharmacology*; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology*
D000199:Actins; D005947:Glucose; D051057:Proto-Oncogene Proteins c-akt; D013549:Sweetening Agents; D014568:Urokinase-Type Plasminogen Activator; C498862:Acta2 protein, rat
Mesangial cells (MC) proliferation; Signal transduction; Urokinase-type plasminogen activator (uPA)