Butyrate Stimulates Histone H3 Acetylation, RANKL Expression, But Inhibited Osteoprotegerin Expression/Secretion in MG-63 Osteoblastic Cells

Abstract

Butyric acid as a histone deacetylase (HDAC) inhibitor was produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on matrix and mineralization markers’ expression of MG-63 osteoblasts. Cell viability and proliferation were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/Annexin V flow cytometry. Protein and mRNA expression of OPG, and RANKL were analyzed by western blotting and RT-PCR. OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, MMP-2, osteonectin (SPARC), osteocalcin and osteopontin secretion into culture medium were measured by enzyme-linked immunosorbant assay. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and western blot. We found that butyrate induced morphologic changes of growing MG-63 cells, with bigger and flattened in appearance. Butyrate activated histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell number with no marked increase in apoptosis and necrosis. Butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas sRANKL level was below detection limit. Butyrate stimulated 8-isoprostane, MMP-2 and osteopontin secretion, but not procollagen I, osteonectin, osteocalcin in MG-63 cells. In conclusion, butyric acid generated by periodontal and root canal microorganisms may potentially induce bony destruction and impair bone repair by alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2, and osteopontin secretion, and affect cell proliferation. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis of periodontal and periapical destruction.

Changes in the composition of gut and vaginal microbiota in patients with postmenopausal osteoporosis

“…The results showed that the proportion of bacteria involved in butyric acid production significantly decreased in the osteoporosis and osteopenia groups than the control group. Butyric acid can regulate bone metabolism in various ways (45,46). It was reported that people with metabolic diseases and inflammatory diseases usually have low levels of butyrate-producing bacteria in their intestines (47), and that inflammatory cytokines can enhance osteoclast activity, leading to a decrease in bone mass (48).…”

Metabolomics in Periodontal Disease - A Mini Review

“…9 Chung MC et al found in their study that butyric acid affects periodontal destruction and healing. 10 In periodontal disease, there is marked decrease in the level of formic acid, lactic acid, alpha amino butyric acid and formic acid. There is drastic decrease in the level of lactic acid that indicates change in the level of commensal bacteria i.e.…”