Exogenous PAMPs, such as LPS released by bacterial lysis, lead to macrophage M1 polarization and release of large quantities of pro-inflammatory cytokines, including TGF-α and PGE2, as well as proteases, such as matrix metalloproteinase-1 (MMP1), which are key components of the inflammatory cascade response mediating soft tissue degradation in periodontal disease and destruction of alveolar bone. Here, MMP1 is linked to periodontal disorder.