Journal Article

Therapeutic potential for insulin on type 1 diabetes‐associated periodontitis: Analysis of experimental periodontitis in streptozotocin‐induced diabetic rats

Adachi, Kei, Naruse, Keiko, Nishikawa, Toru, Mizutani, Makoto, Kikuchi, Takeshi, Honda, Masaki, Noguchi, Toshihide, Nakamura, Nobuhisa, Mitani, Akio, Miyabe, Megumi, Minato, Tomomi, Suzuki, Yuki, Miyajima, Shin‐ichi, Toriumi, Taku, Matsubara, Tatsuaki, Ohno, Norikazu, Sawada, Noritaka, Kobayashi, Yasuko

2020

Overview

Aims/Introduction The association between diabetes and periodontal disease is considered to be bidirectional. However, there is still controversy surrounding the relationship between periodontal disease and type 1 diabetes. We investigated whether insulin improves periodontitis without any local treatments for periodontitis under type 1 diabetes conditions using the ligature‐induced experimental periodontitis model. Materials and Methods Type 1 diabetic rats were induced by streptozotocin injection. Experimental periodontitis was induced by ligature in normal and diabetic rats. Half of the diabetic rats were treated with insulin. Two weeks after the ligature, periodontitis was evaluated. Results Insulin treatment significantly improved inflammatory cell infiltration and inflammatory cytokine gene expression, leading to suppression of alveolar bone loss, in the periodontitis of diabetic rats. Insulin also suppressed the periodontitis‐increased nitric oxide synthase‐positive cells in periodontal tissue of the diabetic rats. Even without induction of periodontitis, diabetic rats showed decreased gingival blood flow and an increased number of nitric oxide synthase‐positive cells in the gingiva and alveolar bone loss compared with normal rats, all of which were ameliorated by insulin treatment. We further confirmed that insulin directly suppressed lipopolysaccharide‐induced inflammatory cytokine expressions in THP‐1 cells. Conclusions There were abnormalities of periodontal tissue even without the induction of periodontitis in streptozotocin‐induced diabetic rats. Insulin treatment significantly ameliorated periodontitis without local periodontitis treatment in diabetic rats. These data suggest the therapeutic impacts of insulin on periodontitis in type 1 diabetes. There was a slight increase in the numbers of inflammatory cells in the gingiva on the periodontitis side of normal rats and on the control side of diabetic rats. The inflammatory cells were markedly increased on the periodontitis side of diabetic rats. Insulin treatment decreased the inflammatory cells in the periodontitis gingiva of diabetic rats.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: Alveolar bone / Animals / Blood flow / Bone loss / Cytokines / Deoxyribonucleic acid / Diabetes / Diabetes mellitus (insulin dependent) / Diabetes Mellitus, Experimental - complications / Diabetes Mellitus, Type 1 - complications / DNA / Experiments / Gene expression / Glucose / Gum disease / Hemoglobin / Humans / Hypoglycemic Agents - therapeutic use / Inflammation / Insulin / Insulin - therapeutic use / Lipopolysaccharides / Male / Nitric-oxide synthase / Original / Periodontal diseases / Periodontitis / Periodontitis - drug therapy / Periodontitis - etiology / Periodontitis - pathology / Rats / Rats, Sprague-Dawley / Rodents / Streptozocin / Tumor necrosis factor-TNF / Type 1 diabetes