Overexpression of decorin induces apoptosis and cell growth arrest in cultured rat mesangial cells in vitro.
BACKGROUND
Decorin (DCN) is a small leucine-rich proteoglycan that plays an important role in the regulation of intercellular contact, cell migration and proliferation. DCN suppresses cell growth and induces apoptosis in various tumour cells. The aim of this study was to investigate whether overexpression of DCN could induce apoptosis and cell growth arrest in mesangial cells (MsCs) in vitro.


METHODS
PcDNA3.1A-DCN plasmid was transfected into cultured rat MsCs, and positive clones stably expressing DCN (MsC/DCN) were selected. SiRNA was used for blocking DCN expression in MsC/DCN. Apoptosis and cell growth of MsCs were assayed by flow cytometry. Hoechst staining was used for observing apoptotic cells. Expressions of active Caspase-3, epidermal growth factor receptor (EGFR), P21 and transforming growth factor-beta (TGF-beta1) were analyzed using Western blot.


RESULTS
Overexpression of DCN in MsCs induced apoptosis and arrested cells in the G(0)/G(1) phase. The protein level of active Caspase-3 was significantly elevated in MsC/DCN (P < 0.01). DCN transfection induced downregulation of EGFR and up-expression of P21. In addition, the expression of TGF-beta1 was significantly inhibited. DCN-siRNA transfection remarkably blocked the expression of DCN and reversed the downregulatory effects of DCN on MsC's proliferation.


CONCLUSIONS
Overexpression of DCN could inhibit MsCs proliferation by inducing apoptosis and cell growth arrest in vitro and it also downregulates expression of TGF-beta1. These results suggest novel strategies for regulating the proliferation of MsC in glomerular diseases.
Department of Pathology and Key Laboratory of Molecular Medicine, Ministry of Education of China, Fudan University, Shanghai, China.
Huijuan
H
Wu
Suxia
S
Wang
Aimin
A
Xue
Yuan
Y
Liu
Ye
Y
Liu
Huijun
H
Wang
Qi
Q
Chen
Muyi
M
Guo
Zhigang
Z
Zhang
D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle; D049109:Cell Proliferation; D002478:Cells, Cultured; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D058575:Decorin; D066246:ErbB Receptors / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D005434:Flow Cytometry; D008297:Male; D050527:Mesangial Cells / Q000166:cytology*; D011509:Proteoglycans / Q000037:antagonists & inhibitors / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D053773:Transforming Growth Factor beta1 / Q000235:genetics
C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; C546880:Dcn protein, rat; D058575:Decorin; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans; D034741:RNA, Small Interfering; D053773:Transforming Growth Factor beta1; D066246:ErbB Receptors; D053148:Caspase 3