title: A three-dimensional collagen lattice induces protein kinase C-zeta activity: role in alpha2 integrin and collagenase mRNA expression.
abstract: A three-dimensional collagen lattice can provide skin fibroblasts with a cell culture environment that simulates normal dermis. Such a collagen matrix environment regulates interstitial collagenase (type I metalloproteinase [MMP-1], collagenase-1) and collagen receptor alpha2 subunit mRNA expression in both unstimulated or platelet-derived growth factor-stimulated dermal fibroblasts (Xu, J., and R.A.F. Clark. 1996. J. Cell Biol. 132:239-249). Here we report that the collagen gel can signal protein kinase C (PKC)-zeta activation in human dermal fibroblasts. An in vitro kinase assay demonstrated that autophosphorylation of PKC-zeta immunoprecipitates was markedly increased by a collagen matrix. In contrast, no alteration in PKC-zeta protein levels or intracellular location was observed. DNA binding activity of nuclear factor kappaB (NF-kappaB), a downstream regulatory target of PKC-zeta, was also increased by fibroblasts grown in collagen gel. The composition of the NF-kappaB/Rel complexes that contained p50, was not changed. The potential role of PKC-zeta in collagen gel-induced mRNA expression of collagen receptor alpha2 subunit and human fibroblast MMP-1 was assessed by the following evidence. Increased levels of alpha2 and MMP-1 mRNA in collagen gel-stimulated fibroblasts were abrogated by bisindolylmaleimide GF 109203X and calphostin C, chemical inhibitors for PKC, but retained when cells were depleted of 12-myristate 13-acetate (PMA)-inducible PKC isoforms by 24 h of pretreatment with phorbol PMA. Antisense oligonucleotides complementary to the 5' end of PKC-zeta mRNA sequences significantly reduced the collagen lattice-stimulated alpha2 and MMP-1 mRNA levels. Taken together, these data indicate that PKC-zeta, a PKC isoform not inducible by PMA or diacylglycerol, is a component of collagen matrix stimulatory pathway for alpha2 and MMP-1 mRNA expression. Thus, a three-dimensional collagen lattice maintains the dermal fibroblast phenotype, in part, through the activation of PKC-zeta.
authors.affiliation: Department of Dermatology, School of Medicine, SUNY at Stony Brook, New York 11794-8165, USA.
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: R A
authors.initials: RA
authors.lastname: Clark
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D000077214:Becaplermin; D002467:Cell Nucleus / Q000201:enzymology; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry* / Q000502:physiology*; D017364:Collagenases / Q000096:biosynthesis* / Q000235:genetics; D003593:Cytoplasm / Q000201:enzymology; D004247:DNA / Q000378:metabolism; D004789:Enzyme Activation; D005782:Gels; D006801:Humans; D039421:Integrin alpha2; D020781:Matrix Metalloproteinase 1; D016328:NF-kappa B / Q000378:metabolism; D016376:Oligonucleotides, Antisense; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D014176:Protein Biosynthesis; D011493:Protein Kinase C / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013873:Thionucleotides; D000099221:Protein Kinase C zeta
chemical_list: D015703:Antigens, CD; D000077214:Becaplermin; D003094:Collagen; D017364:Collagenases; D004247:DNA; D005782:Gels; D039421:Integrin alpha2; D020781:Matrix Metalloproteinase 1; D016328:NF-kappa B; D016376:Oligonucleotides, Antisense; D010982:Platelet-Derived Growth Factor; D011493:Protein Kinase C; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; D013873:Thionucleotides; D000099221:Protein Kinase C zeta