High Glucose Affects Proliferation, Reactive Oxygen Species and Mineralization of Human Dental Pulp Cells

Abstract

Diabetes is a group of metabolic disorders that can lead to damage and dysfunction of many organs including the dental pulp. Increased inflammatory response, reduction of dentin formation and impaired healing were reported in diabetic dental pulp. Hyperglycemia, which is a main characteristic of diabetes, was suggested to play a role in many diabetic complications. Therefore our aim was to investigate the effects of high glucose levels on proliferation, reactive oxygen species (ROS) production and odontogenic differentiation of human dental pulp cells (HDPCs). HDPCs were cultured under low glucose (5.5mM Glucose), high glucose (25 mM Glucose) and mannitol (iso-osmolar control) conditions. Cell proliferation was analyzed by MTT assay for 11 days. Glutathione and DCFH-DA assay were used to assess ROS and antioxidant levels after 24 h of glucose exposure. Odontogenic differentiation was evaluated and quantified by alizarin red staining on day 21. Expression of mineralization-associated genes, which were alkaline phosphatase, dentin sialophosphoprotein and osteonectin, was determined by RT-qPCR on day 14. The results showed that high glucose concentration decreased proliferation of HDPCs. Odontogenic differentiation, both by gene expression and mineral matrix deposit, was inhibited by high glucose condition. In addition, high DCF levels and low reduced glutathione levels were observed in high glucose condition. However, no differences were observed between mannitol and low glucose conditions. In conclusion, the results clearly showed the negative effect of high glucose condition on HDPCs proliferation and differentiation. Moreover, it also induced ROS production of HDPCs.

Bacterial quantity and interleukin‐17 expression in necrotic teeth with apical periodontitis from type II diabetic patients

“…It demonstrated that the induced periapical lesions were significantly larger with severe alveolar bone resorption and more bacteria in the diabetic rat's model than in non‐diabetic controls (Fouad et al, 2002; Iwama et al, 2003; Kohsaka, 1996; Samuel et al, 2019). This suggests that the hyperglycaemic environment, impaired immune response and dental pulp circulatory disorders resulted in decreased oxygen supply that favours microorganism proliferation and promotes colonization, especially the growth of anaerobic organisms in diabetic patients (Bender & Bender, 2003; Horsophonphong et al, 2020).…”

The Role of Cellular Metabolism in Maintaining the Function of the Dentine-Pulp Complex: A Narrative Review

“…Previously, it was reported that elevated AGE levels might promote pulp calcification in diabetic rats [126]. In contrast, high glucose levels inhibited the proliferation of human dental pulp cells and their odontogenic differentiation, as well as stimulated ROS production [127]. Therefore, hyperglycaemia plays a negative role in the healing and regeneration of pulp and periapical tissues in patients with diabetes.…”

“…Based on an in vitro study, Horsophonphong et al [127] found that high glucose levels decreased the proliferation and odontogenic differentiation of human dental pulp cells. Additionally, a high glucose level induced ROS production and reduced glutathione (GSH) level, suggesting an imbalance between free radical synthesis and antioxidant defence that may cause cellular damage.…”

Oyster Mushroom (Pleurotus Ostreatus) Ethanolic Extract Protects Yeast Cells From Hyper- And Hypo-Glycemic Stress

“…Cell treatment with ethanolic extract of P. ostreatus caused a slight but significant increase in reduced RGR (Figure 2B). High and low glucose conditions markedly affect the proliferation of most cells (Horsophonphong et al, 2020;Pluskal et al, 2011) due to variable glucosemediated responses including alterations in gene expression, metabolic processes, or antioxidant status of the cell. This suggests that the positive effect of P. ostreatus extract on cell proliferation results from its collateral impact on the regulation of different essential cellular processes.…”