Induction of matrix metalloproteinase-9 (MMP-9) in lipopolysaccharide-stimulated primary astrocytes is mediated by extracellular signal-regulated protein kinase 1/2 (Erk1/2).
In the present study, we investigated whether the activation of protein kinase C (PKC) and extracellular signal-regulated kinase 1/2 (Erk1/2) are involved in the induction of MMP-9 in lipopolysaccharide (LPS)-stimulated primary astrocytes. The expression of MMP-9 but not MMP-2 was increased by LPS. LPS treatment induced activation of Erk1/2 within 30 min, which was dose-dependently inhibited by PD98059, a specific inhibitor of the Erk kinase (MEK). In this condition, PD98059 blocked the increase in MMP-9 protein and mRNA level as well as gelatin-digesting activity. Inhibition of PKC activity blocked the LPS-induced activation of Erk1/2 as well as MMP-9 expression. In addition, activation of PKC by phorbol myristoyl acetate (PMA) activated Erk1/2 with concomitant increase in MMP-9 production. Moreover, treatment of PD98059 dose-dependently decreased the PMA-induced MMP-9 expression. The results from the present study suggest that induction of MMP-9 by LPS in rat primary astrocytes is mediated, at least in part, by the sequential activation of PKC and Erk1/2. The Erk1/2-mediated MMP-9 induction may provide insights into the regulation of MMP-9 production in CNS, which may occur in vivo in pathological situations such as CNS inflammation.
Lee
Woo Jong
WJ
Department of Pharmacology, College of Pharmacy, Seoul National University, Korea.
Shin
Chan Young
CY
Yoo
Byoung Kwon
BK
Ryu
Jae Ryun
JR
Choi
Eui Yul
EY
Cheong
Jae Hoon
JH
Ryu
Jong Hoon
JH
Ko
Kwang Ho
KH
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D020536:Enzyme Activators / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D005419:Flavonoids; D008070:Lipopolysaccharides; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one