Regulation of matrix metalloproteinase-2 production by cytokines and pharmacological agents in human pulp cell cultures

Type IV matrix metalloproteinases (MMPs) are members of the family of MMPs and are thought to play an important role in degradation of extracellular c omponents. Human pulp cells can secrete and produce these enzymes. Recent e vidence shows that MMPs may play a role in pulpal inflammation. To date lit tle is known regarding the regulation of MMPs in human pulp cell cultures. The purpose of this study was to determine the effects of cytokines (interl eukin-1 and transforming growth factor-beta (TGF-beta), protein synthesis i nhibitor cycloheximide (CD), and protein kinase C inhibitors (H7 and Go6976 ) on the secretion and production of MMPs by human pulp cell cultures using gelatin zymography. The main gelatinase secreted by human pulp cells migra ted at 72 kDa and respresented MMP-2. Minor gelatinolytic bands were also o bserved at 92 kDa regions that correspond to MMP-9. After an 8-day culture period TGF-beta, CD, H7, and Go6976 were found to depress MMP-2 production. The inhibition decreased in an order of CD > H7 > TGF-beta > Go6976. IL-1 was found to elevate MMP-2 production. Human pulp cells, however treated wi th either cytokines or pharmacological agents had no effect on the pattern of MMP-9 produced or secreted in either cell extracts or conditioned medium fractions. These observations suggest that the cytokines and pharmacologic al agents can regulate MMP-2 produced by human pulp cells. Inflammatory cyt okines stimulate the production of elevated levels of MMP-2 and MMP-2 might playa role in pulpal inflammation. In addition agents that target protein synthesis or the protein kinase C pathway in human pulp cells inhibit MMP-2 production, and such inhibition may contribute to the pathogenesis of pulp al inflammation. Such inhibition might contribute to therapeutic efficacy.