Berberine inhibits platelet-derived growth factor-induced growth and migration partly through an AMPK-dependent pathway in vascular smooth muscle cells.
Platelet-derived growth factor (PDGF) is released from vascular smooth muscle cells (VSMCs), endothelial cells, or macrophages after percutaneous coronary intervention and is related with neointimal proliferation and restenosis. Berberine is a well-known component of the Chinese herb medicine Huanglian (Coptis chinensis), and is capable of inhibiting growth and endogenous PDGF synthesis in VSMCs after in vitro mechanical injury. We analyzed the effects of berberine on VSMC growth, migration, and signaling events after exogenous PDGF stimulation in vitro in order to mimic a post-angioplasty PDGF shedding condition. Pretreatment of VSMCs with berberine inhibited PDGF-induced proliferation. Berberine significantly suppressed PDGF-stimulated Cyclin D1/D3 and Cyclin-dependent kinase (Cdk) gene expression. Moreover, berberine increased the activity of AMP-activated protein kinase (AMPK), which led to phosphorylation activation of p53 and increased protein levels of the Cdk inhibitor p21(Cip1). Compound C, an AMPK inhibitor, partly but significantly attenuated berberine-elicited growth inhibition. In addition, stimulation of VSMCs with PDGF led to a transient increase in GTP-bound, active form of Ras, Cdc42 and Rac1, as well as VSMC migration. However, pretreatment with berberine significantly inhibited PDGF-induced Ras, Cdc42 and Rac1 activation and cell migration. Co-treatment with farnesyl pyrophosphate and geranylgeranyl pyrophosphate drastically reversed berberine-mediated anti-proliferative and migratory effects in VSMCs. Based on these findings, we conclude that berberine inhibited PDGF-induced VSMC growth via activation of AMPK/p53/p21(Cip1) signaling while inactivating Ras/Rac1/Cyclin D/Cdks and suppressing PDGF-stimulated migration via inhibition of Rac1 and Cdc42. These observations offer a molecular explanation for the anti-proliferative and anti-migratory properties of berberine.
Liang
Kae-Woei
KW
Institute of Clinical Medicine, Cardiovascular Research Center and Department of Medicine, National Yang-Ming University, Taipei, Taiwan.
Yin
Sui-Chu
SC
Ting
Chih-Tai
CT
Lin
Shing-Jong
SJ
Hsueh
Chi-Mei
CM
Chen
Chiu-Yuan
CY
Hsu
Shih-Lan
SL
D055372:AMP-Activated Protein Kinases; D000818:Animals; D001599:Berberine / Q000494:pharmacology*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000032:analysis; D056743:Cyclin D3; D016213:Cyclins / Q000032:analysis; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D009097:Multienzyme Complexes / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
C534698:Ccnd3 protein, rat; D056743:Cyclin D3; D016213:Cyclins; D009097:Multienzyme Complexes; D010982:Platelet-Derived Growth Factor; D001599:Berberine; D019938:Cyclin D1; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D020830:rac1 GTP-Binding Protein