Role of thrombin-PAR1-PKCθ/δ axis in brain pericytes in thrombin-induced MMP-9 production and blood-brain barrier dysfunction in vitro.
Thrombin, an essential component in the coagulation cascade, participates in the pathogenesis of brain diseases, such as ischemic stroke, intracerebral hemorrhage, Alzheimer's disease and Parkinson's disease through blood-brain barrier (BBB) dysfunction. It is thought that the thrombin-matrix metalloproteinase (MMP)-9 axis is an important process in the pathogenesis of neurovascular disease, such as BBB dysfunction. We recently reported that brain pericytes are the most MMP-9-releasing cells in response to thrombin stimulation among the BBB-constituting cells. This thrombin-induced MMP-9 release is partially due to protease-activated receptor (PAR1), one of the specific thrombin receptors. Then, we evaluated the intracellular signaling pathways involved in MMP-9 release and the contribution of thrombin-reactive brain pericytes to BBB dysfunction. PKC activator evoked MMP-9 release from brain pericytes. The thrombin-induced MMP-9 release was inhibited by U0126, LY294002, Go6976, and Go6983. However, Go6976 decreased phosphorylation levels of PKCθ and Akt, and Go6983 decreased phosphorylation levels of PKCδ and extracellular signal-regulated kinase (ERK). Additionally, treatment of pericytes with thrombin or PAR1-activating peptide stimulated PKCδ/θ signaling. These substances impaired brain endothelial barrier function in the presence of brain pericytes. Brain pericytes function through two independent downstream signaling pathways via PAR1 activation to release MMP-9 in response to thrombin - the PKCθ-Akt pathway and the PKCδ-ERK1/2 pathway. These pathways participate in PAR1-mediated MMP-9 release from pericytes, which leads to BBB dysfunction. Brain pericytes and their specific signaling pathways could provide novel therapeutic targets for thrombin-induced neurovascular diseases.
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Takashi
T
Machida
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Shinya
S
Dohgu
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan; BBB Laboratory, PharmaCo-Cell Co., Ltd., Nagasaki, Japan.
Fuyuko
F
Takata
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Junichi
J
Matsumoto
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Ikuya
I
Kimura
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Mariko
M
Koga
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Keiko
K
Nakamoto
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Atsushi
A
Yamauchi
Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan; BBB Laboratory, PharmaCo-Cell Co., Ltd., Nagasaki, Japan. Electronic address: ykataoka@fukuoka-u.ac.jp.
Yasufumi
Y
Kataoka
D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D020286:Pericytes / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000378:metabolism*; D000074121:Protein Kinase C-theta / Q000378:metabolism*; D051381:Rats; D044463:Receptor, PAR-1 / Q000378:metabolism*; D018179:Receptors, Thrombin / Q000378:metabolism; D013917:Thrombin / Q000378:metabolism*
D044463:Receptor, PAR-1; D018179:Receptors, Thrombin; D051745:Protein Kinase C-delta; D000074121:Protein Kinase C-theta; D048049:Extracellular Signal-Regulated MAP Kinases; D013917:Thrombin; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat
cell signaling; in vitro BBB model; pericyte; permeability; thrombin