Activation of protein kinase Czeta is essential for cytokine-induced metalloproteinase-1, -3, and -9 secretion from rabbit smooth muscle cells and inhibits proliferation.
Several matrix metalloproteinases (MMPs), including MMP-1, -3, and -9, mediate matrix destruction during chronic inflammatory diseases such as arthritis and atherosclerosis. MMP up-regulation by inflammatory cytokines involves interactions between several transcription factors, including activator protein-1 and nuclear factor kappaB (NF-kappaB). The upstream regulatory pathways are less well understood. We investigated the role of isoforms of protein kinase C (PKC) in basic fibroblast growth factor- and interleukin-1alpha-mediated MMP production from cultured rabbit aortic smooth muscle cells. A synthetic PKC inhibitor, RO318220, inhibited MMP-1, -3, and -9 production by 89 +/- 3, 75 +/- 18, and 89 +/- 9%, respectively. However, down-regulation of conventional and novel isoforms did not inhibit but rather increased MMP-9 production by 48 +/- 16%, implicating an atypical PKC isoform. Consistent with this, PKCzeta protein levels and activity were stimulated 3.3- and 13-fold, respectively, by basic fibroblast growth factor plus interleukin-1alpha and antisense oligonucleotides to PKCzeta significantly decreased MMP-9 formation by 62 +/- 18% compared with scrambled sequences. Moreover, adenovirus-mediated overexpression of a dominant-negative (DN) PKCzeta reduced MMP-1, -3, and -9 production by 78 +/- 9, 76 +/- 8, and 76 +/- 5%, respectively. DN-PKCzeta inhibited NF-kappaB DNA binding but did not affect ERK1/2 activation or AP-1 binding. Antisense PKCzeta oligonucleotides and DN-PKCzeta stimulated cell proliferation by 89 +/- 14% (n = 4) and 305 +/- 74% (n = 3), respectively (both p < 0.05). Our results show that PKCzeta is essential for cytokine-induced up-regulation of MMP-1, -3, and -9, most likely by activating NF-kappaB. Selective inhibition of PKCzeta is therefore a possible strategy to inhibit MMP production in inflammatory diseases such as atherosclerosis.
Hussain
Shaista
S
Bristol Heart Institute and University Research Centre for Neuroendocrinology, Royal Infirmary, University of Bristol, Bristol BS2 8HW, UK.
Assender
Jean W
JW
Bond
Mark
M
Wong
Liang-Fong
LF
Murphy
David
D
Newby
Andrew C
AC
D000818:Animals; D015153:Blotting, Western; D002455:Cell Division; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D015536:Down-Regulation; D004789:Enzyme Activation; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005799:Genes, Dominant; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009130:Muscle, Smooth / Q000166:cytology; D009841:Oligonucleotides / Q000494:pharmacology; D016376:Oligonucleotides, Antisense / Q000378:metabolism / Q000494:pharmacology; D010703:Phorbol Esters / Q000378:metabolism; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000378:metabolism*; D011817:Rabbits; D015854:Up-Regulation; D000099221:Protein Kinase C zeta
D016207:Cytokines; D016222:Fibroblast Growth Factor 2; D020781:Matrix Metalloproteinase 1; D019278:Matrix Metalloproteinase 3; D020780:Matrix Metalloproteinase 9; D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D010703:Phorbol Esters; D020033:Protein Isoforms; D011493:Protein Kinase C; D000099221:Protein Kinase C zeta