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Keratinocyte stimulation of matrix metalloproteinase-1 production and proliferation in fibroblasts: regulation through mitogen-activated protein kinase signalling events.

Moon SE, Bhagavathula N, Varani J - Br. J. Cancer (2002)

Bottom Line: In fibroblasts exposed to keratinocyte-conditioned medium, mitogen-activated protein kinase signalling through both the extracellular signal-related kinase pathway and p38 pathway occurred.A p38 signalling inhibitor (SB203580) blocked matrix metalloproteinase-1 elaboration induced by keratinocyte-conditioned medium or interleukin-1beta, but did not inhibit matrix metalloproteinase-1 elaboration or cell growth induced by epidermal growth factor.These data indicate that keratinocyte-fibroblast interactions are mediated by multiple stimulating agents acting on specific receptors to induce signalling through different mitogen-activated protein kinase pathways leading to altered expression of key biological functions.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The University of Michigan Medical School, 1301 Catherine Road, Box 0602, Ann Arbor, Michigan, MI 48109, USA.

ABSTRACT
Incubation of human dermal fibroblasts in keratinocyte-conditioned culture medium led to a 5.7-fold increase in the level of matrix metalloproteinase-1. Virtually all of the matrix metalloproteinase-1 - inducing activity could be related to agonists acting through members of the epidermal growth factor receptor family or to agonists acting through the interleukin-1 receptor. The same keratinocyte-conditioned medium also induced a modest increase in fibroblast proliferation (approximately 1.8-fold). Growth-stimulating activity could be attributed to epidermal growth factor receptor (but not interleukin-1 receptor) function. In fibroblasts exposed to keratinocyte-conditioned medium, mitogen-activated protein kinase signalling through both the extracellular signal-related kinase pathway and p38 pathway occurred. When recombinant epidermal growth factor or recombinant interleukin-1beta were used as a control, they induced mitogen-activated protein kinase signalling consistent with the combined effects of epidermal growth factor receptor - specific and interleukin-1 receptor - specific agonists in keratinocyte-conditioned medium. Recombinant epidermal growth factor stimulated both matrix metalloproteinase-1 induction and proliferation while recombinant interleukin-1beta stimulated matrix metalloproteinase-1 elaboration but not fibroblast growth. An inhibitor of extracellular signal-related kinase pathway signalling (U0126) blocked induction of matrix metalloproteinase-1 production induced by keratinocyte-conditioned medium (as well as by epidermal growth factor or interleukin-1beta), and also inhibited proliferation. A p38 signalling inhibitor (SB203580) blocked matrix metalloproteinase-1 elaboration induced by keratinocyte-conditioned medium or interleukin-1beta, but did not inhibit matrix metalloproteinase-1 elaboration or cell growth induced by epidermal growth factor. These data indicate that keratinocyte-fibroblast interactions are mediated by multiple stimulating agents acting on specific receptors to induce signalling through different mitogen-activated protein kinase pathways leading to altered expression of key biological functions.

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Effects of an IL-1 receptor antagonist and an EGF receptor tyrosine kinase antagonist (PD169540) on p38 phosphorylation induced by keratinocyte-conditioned medium. Fibroblasts were exposed for 30 or 60 min to culture medium alone or to a 50 : 50 mixture of culture medium and keratinocyte-conditioned medium with or without 50 μg ml−1 IL-1 receptor antagonist or 1 μM PD169540. At the end of the incubation period, extracts were prepared and assayed for phospho-p38 expression as described in the Materials and Methods section. Values shown are expressed as fold-induction relative to the level detected in cells exposed to culture medium alone. The insert demonstrates a Western blot from one experiment. p38-P=phosphorylated p38. p38-SS=total p38 protein.
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fig5: Effects of an IL-1 receptor antagonist and an EGF receptor tyrosine kinase antagonist (PD169540) on p38 phosphorylation induced by keratinocyte-conditioned medium. Fibroblasts were exposed for 30 or 60 min to culture medium alone or to a 50 : 50 mixture of culture medium and keratinocyte-conditioned medium with or without 50 μg ml−1 IL-1 receptor antagonist or 1 μM PD169540. At the end of the incubation period, extracts were prepared and assayed for phospho-p38 expression as described in the Materials and Methods section. Values shown are expressed as fold-induction relative to the level detected in cells exposed to culture medium alone. The insert demonstrates a Western blot from one experiment. p38-P=phosphorylated p38. p38-SS=total p38 protein.

Mentions: Additional experiments were conducted in which an IL-1 receptor antagonist and a potent EGF receptor tyrosine kinase antagonist (PD169540) were examined for ability to modulate p38 phosphorylation induced by keratinocyte culture fluid. In the presence of IL-1 receptor antagonist (50 μg ml−1), p38 phosphorylation was inhibited by 80% at 30 min and virtually 100% at 60 min. Not surprising in light of the failure of EGF to induce p38 phosphorylation, PD169540 (1 μM) was completely ineffective in preventing p38 phosphorylation (Figure 5Figure 5


Keratinocyte stimulation of matrix metalloproteinase-1 production and proliferation in fibroblasts: regulation through mitogen-activated protein kinase signalling events.

Moon SE, Bhagavathula N, Varani J - Br. J. Cancer (2002)

Effects of an IL-1 receptor antagonist and an EGF receptor tyrosine kinase antagonist (PD169540) on p38 phosphorylation induced by keratinocyte-conditioned medium. Fibroblasts were exposed for 30 or 60 min to culture medium alone or to a 50 : 50 mixture of culture medium and keratinocyte-conditioned medium with or without 50 μg ml−1 IL-1 receptor antagonist or 1 μM PD169540. At the end of the incubation period, extracts were prepared and assayed for phospho-p38 expression as described in the Materials and Methods section. Values shown are expressed as fold-induction relative to the level detected in cells exposed to culture medium alone. The insert demonstrates a Western blot from one experiment. p38-P=phosphorylated p38. p38-SS=total p38 protein.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2376127&req=5

fig5: Effects of an IL-1 receptor antagonist and an EGF receptor tyrosine kinase antagonist (PD169540) on p38 phosphorylation induced by keratinocyte-conditioned medium. Fibroblasts were exposed for 30 or 60 min to culture medium alone or to a 50 : 50 mixture of culture medium and keratinocyte-conditioned medium with or without 50 μg ml−1 IL-1 receptor antagonist or 1 μM PD169540. At the end of the incubation period, extracts were prepared and assayed for phospho-p38 expression as described in the Materials and Methods section. Values shown are expressed as fold-induction relative to the level detected in cells exposed to culture medium alone. The insert demonstrates a Western blot from one experiment. p38-P=phosphorylated p38. p38-SS=total p38 protein.
Mentions: Additional experiments were conducted in which an IL-1 receptor antagonist and a potent EGF receptor tyrosine kinase antagonist (PD169540) were examined for ability to modulate p38 phosphorylation induced by keratinocyte culture fluid. In the presence of IL-1 receptor antagonist (50 μg ml−1), p38 phosphorylation was inhibited by 80% at 30 min and virtually 100% at 60 min. Not surprising in light of the failure of EGF to induce p38 phosphorylation, PD169540 (1 μM) was completely ineffective in preventing p38 phosphorylation (Figure 5Figure 5

Bottom Line: In fibroblasts exposed to keratinocyte-conditioned medium, mitogen-activated protein kinase signalling through both the extracellular signal-related kinase pathway and p38 pathway occurred.A p38 signalling inhibitor (SB203580) blocked matrix metalloproteinase-1 elaboration induced by keratinocyte-conditioned medium or interleukin-1beta, but did not inhibit matrix metalloproteinase-1 elaboration or cell growth induced by epidermal growth factor.These data indicate that keratinocyte-fibroblast interactions are mediated by multiple stimulating agents acting on specific receptors to induce signalling through different mitogen-activated protein kinase pathways leading to altered expression of key biological functions.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The University of Michigan Medical School, 1301 Catherine Road, Box 0602, Ann Arbor, Michigan, MI 48109, USA.

ABSTRACT
Incubation of human dermal fibroblasts in keratinocyte-conditioned culture medium led to a 5.7-fold increase in the level of matrix metalloproteinase-1. Virtually all of the matrix metalloproteinase-1 - inducing activity could be related to agonists acting through members of the epidermal growth factor receptor family or to agonists acting through the interleukin-1 receptor. The same keratinocyte-conditioned medium also induced a modest increase in fibroblast proliferation (approximately 1.8-fold). Growth-stimulating activity could be attributed to epidermal growth factor receptor (but not interleukin-1 receptor) function. In fibroblasts exposed to keratinocyte-conditioned medium, mitogen-activated protein kinase signalling through both the extracellular signal-related kinase pathway and p38 pathway occurred. When recombinant epidermal growth factor or recombinant interleukin-1beta were used as a control, they induced mitogen-activated protein kinase signalling consistent with the combined effects of epidermal growth factor receptor - specific and interleukin-1 receptor - specific agonists in keratinocyte-conditioned medium. Recombinant epidermal growth factor stimulated both matrix metalloproteinase-1 induction and proliferation while recombinant interleukin-1beta stimulated matrix metalloproteinase-1 elaboration but not fibroblast growth. An inhibitor of extracellular signal-related kinase pathway signalling (U0126) blocked induction of matrix metalloproteinase-1 production induced by keratinocyte-conditioned medium (as well as by epidermal growth factor or interleukin-1beta), and also inhibited proliferation. A p38 signalling inhibitor (SB203580) blocked matrix metalloproteinase-1 elaboration induced by keratinocyte-conditioned medium or interleukin-1beta, but did not inhibit matrix metalloproteinase-1 elaboration or cell growth induced by epidermal growth factor. These data indicate that keratinocyte-fibroblast interactions are mediated by multiple stimulating agents acting on specific receptors to induce signalling through different mitogen-activated protein kinase pathways leading to altered expression of key biological functions.

Show MeSH
Related in: MedlinePlus