Effects of a bacterial lipid byproduct on human pulp fibroblasts in vitro.
Butyrate, a short chain fatty acid, is a metabolic lipid byproduct of various root canal pathogens, such as Porphyromonas endodontalis. However, little is known about the effects of butyrate on cultured human pulp fibroblasts. H33258 fluorescence, flow cytometry, and protein synthesis assays were used to investigate the pathobiologic effects of butyrate on cultured human pulp fibroblasts. Butyrate exhibited cytotoxic effects on human pulp fibroblasts in a concentration-dependent manner (p < 0.05). The addition of butyrate resulted in G2/M phase arrest (p < 0.05). Butyrate also inhibited protein synthesis in a dose-dependent manner (p < 0.05). To determine whether glutathione (GSH) levels were important in the cytotoxicity of butyrate, we pretreated cells with the GSH precursor, 2-oxothiazolidine-4-carboxylic acid (OTZ), to boost thiol levels, or buthionine sulfoximine (BSO) to deplete GSH. The addition of OTZ acted as a protective effect on the butyrate-induced cytotoxicity (p < 0.05). In contrast, the addition of BSO enhanced the butyrate-induced cytotoxicity (p < 0.05). These results indicate that butyrate is cytotoxic to human pulp fibroblasts by inhibiting cell growth, cell-cycle kinetics, and protein synthesis. These inhibitory effects were associated with intracellular GSH levels.
Ho
Yung-Chuan
YC
School of Applied Chemistry, Chung Shan Medical University, Taichung, Taiwan.
Chang
Yu-Chao
YC
D001419:Bacteria / Q000378:metabolism; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D002087:Butyrates / Q000633:toxicity*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D005453:Fluorescence; D016195:G2 Phase / Q000187:drug effects; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006801:Humans; D008066:Lipolysis; D011498:Protein Precursors / Q000494:pharmacology; D011506:Proteins / Q000037:antagonists & inhibitors; D011761:Pyrrolidonecarboxylic Acid / Q000494:pharmacology; D053778:Thiazolidines / Q000494:pharmacology
D002087:Butyrates; D004791:Enzyme Inhibitors; D011498:Protein Precursors; D011506:Proteins; D053778:Thiazolidines; D019328:Buthionine Sulfoximine; D005978:Glutathione; D011761:Pyrrolidonecarboxylic Acid; C029536:2-oxothiazolidine-4-carboxylic acid