Differential regulation of matrix metalloproteinase-2 and -9 expression and activity in adult rat cardiac fibroblasts in response to interleukin-1beta.
Matrix metalloproteinases (MMPs), a family of endoproteinases, are implicated in cardiac remodeling. Interleukin-1beta (IL-1beta), which is increased in the heart following myocardial infarction, increases expression and activity of MMP-2 (gelatinase A) and -9 (gelatinase B) in cardiac fibroblasts. Previously, we have shown that IL-1beta activates ERK1/2, JNKs, and protein kinase C (PKC). However, signaling pathways involved in the regulation of MMP-2 and -9 expression and activity are not yet well understood. Using adult rat cardiac fibroblasts, we show that inhibition of ERK1/2 and JNKs inhibits IL-1beta-stimulated increases in MMP-9, not MMP-2, expression and activity. Chelerythrine, an inhibitor of PKC, inhibited activation of ERK1/2 and JNKs and expression and activity of both MMPs. Selective inhibition of PKC-alpha/beta1 using Gö6976 inhibited JNKs activation and the expression and activity of MMP-9, not MMP-2. Inhibition of PKC-theta and PKC-zeta using pseudosubstrates inhibited IL-1beta-stimulated activation of ERK1/2 and JNKs and the expression and activity of MMP-2 and -9. Inhibition of PKC-epsilon had no effect. IL-1beta activated NF-kappaB pathway as measured by increased phosphorylation of IKKalpha/beta and IkappaB-alpha. Inhibition of ERK1/2, JNKs, and PKC-alpha/beta1 had no effect on NF-kappaB activation, whereas inhibition of PKC-theta and PKC-zeta inhibited IL-1beta-stimulated activation of NF-kappaB. SN50, NF-kappaB inhibitor peptide, inhibited IL-1beta-stimulated increases in MMP-2 and -9 expression and activity. These observations suggest that 1) activation of ERK1/2 and JNKs plays a critical role in the regulation of MMP-9, not MMP-2, expression and activity; 2) PKC-alpha/beta1 act upstream of JNKs, not ERK1/2; 3) PKC-zeta and -theta, not PKC-epsilon, act upstream of JNKs, ERK1/2, and NF-kappaB; and 4) activation of NF-kappaB stimulates expression and activity of MMP-2 and -9.
Xie
Zhonglin
Z
Department of Physiology, James H Quillen College of Medicine, James H Quillen Veterans Affairs Medical Center, East Tennessee State University, Johnson City, Tennessee 37614, USA.
Singh
Mahipal
M
Singh
Krishna
K
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007375:Interleukin-1 / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2 / Q000235:genetics* / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics* / Q000378:metabolism*; 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; D009206:Myocardium / Q000166:cytology* / Q000201:enzymology; D016328:NF-kappa B / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D000074121:Protein Kinase C-theta; D051381:Rats; D000099221:Protein Kinase C zeta
D004791:Enzyme Inhibitors; D007375:Interleukin-1; D007527:Isoenzymes; D048031:JNK Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016328:NF-kappa B; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta; D000099221:Protein Kinase C zeta; C489591:Prkcq protein, rat