High Glucose-Mediated Cytokine Regulation in Gingival Fibroblasts and THP-1 Macrophage: a Possible Mechanism of Severe Periodontitis with Diabetes

Abstract

Background/Aims: Diabetic patients are susceptible to severe periodontitis, but the precise mechanism is not fully understood. Aim of this study was to explore the biological pathogenesis of severe periodontitis in diabetic patients focusing on the crosstalk of human gingival fibroblasts (HGFs) and macrophages. Methods: A total of 70 periodontitis patients with or without diabetes mellitus (DM) were enrolled, and the statistical relationships of diabetic conditions to the periodontal inflammatory parameters were examined by cross-sectional study. In in vitro study, HGFs cell line CRL-2014® (ATCC) and differentiated THP-1 macrophages were cultured with normal glucose (NG: 5.5 mM) or high glucose (HG: 25 mM) condition, and treated with indicated inflammatory factors such as calprotectin (CPT), interleukin (IL)-1β and IL-6. To examine the effects of HG on soluble IL-6 receptor (sIL-6R) production in THP-1 macrophages, the supernatants were collected and the sIL-6R levels were measured by ELISA. To examine the effects of HG on IL-1β or IL-6-induced matrix metalloproteinase (MMPs) production in HGFs, the supernatants were collected. Levels of MMP-1 and tissue inhibitor of MMP-1 (TIMP-1) were measured by ELISA. Finally, after conditioned medium (CM) from THP-1 macrophages cultured with NG or HG conditions was collected, HGFs were treated with the CM. The supernatants were collected 24 hours later and the levels of MMP-1 and TIMP-1 were measured. To examine the specific effects of IL-1β contained in CM on MMP-1 and TIMP-1 production in HGFs, IL-1 receptor antagonist (IL-1ra) was used. Results: There were statistical correlation between IL-1β and sIL-6R levels in gingival crevicular fluid (GCF) and HbA1c in periodontitis patients with DM (IL-1β: P=0.035, sIL-6R: P=0.040). HG and CPT significantly induced sIL-6R production in THP-1 macrophages. HG significantly enhanced IL-1β or IL-6/sIL-6R-induced MMP-1 production in HGFs. The increase of MMP-1 by both IL-1β and IL-6/sIL-6R was significantly inhibited by specific ERK or IκB inhibitors. Corresponding to the regulation of MMP-1 production, HG condition increased the phosphorylation of p44/42 MAPK and IκBα in HGFs treated with IL-1β or IL-6/sIL-6R. Finally, MMP-1 production in HGFs cultured with HG increased significantly by CM from THP-1 macrophages cultured with HG. The induction of MMP-1 by the CM from THP-1 macrophages cultured with HG was significantly inhibited by dose dependent of IL-1ra in HGFs cultured with HG. Conclusion: Diabetic conditions such as HG induce IL-1β and sIL-6R production from macrophages in inflammatory periodontal tissues and may exacerbate the periodontitis synergistically via MMP-1 production from HGFs.

TET1 Knockdown Inhibits Porphyromonas gingivalis LPS/IFN-γ-Induced M1 Macrophage Polarization through the NF-κB Pathway in THP-1 Cells

“…The M1-related cytokines IL-1β and IL-6, which are secreted by macrophages, induce the expression of matrix metalloproteinases (MMPs) in human gingival fibroblasts (HGFs). MMPs then cause the destruction of gingival collagen fibers in inflamed periodontal tissue under high-glucose conditions [17]. These findings demonstrate that M1 macrophages might play an important role in the occurrence and development of periodontitis.…”

Mechanism of Glucose Water as a Neural Injection: A Perspective on Neuroinflammation

“…The reduction in proinflammatory cytokines and inflammatory mediators by exposure to high glucose suggests a potential correction for cellular impairment (inflammation). Elevated levels of TNF-α have been documented to increase energy expenditure, promote energy updates, and potentially result in glucose deprivation [ 74 , 75 , 76 , 77 , 78 ]. We postulate that pretreatment with TNF-α elevation may initiate a glucose deprivation state, and that high glucose (25 mM) restores impaired glucose metabolism.…”

The relationship between periodontite and diabetes mellitus type ii facing the new classification of periodontal diseases: literature review

“…These can contribute to tissue destruction, characteristic of periodontitis. In sick sites of subjects with uncontrolled diabetes and periodontitis, there is a significant increase in levels of IL-6, TNF-α, known pro-inflammatory cytokines able to synergistically stimulate connective tissue degradation, and bone resorption via MMP-1, which has its production increased by fibroblasts in conditions of hyperglycemia [19,20]. Healthy sites of diabetic individuals have higher concentrations of proinflammatory biomarkers than healthy sites of non-diabetic subjects with the same biomarkers [19].…”