The In Vitro Immunomodulatory Effects of Gold Nanocomplex on THP-1-Derived Macrophages

IMMUNOTOXICITY OF RELEVANT MIXTURES OF PESTICIDES AND METABOLITES ON THP-1 CELLS

Pesticides are used to combat agricultural pests but also trigger side effects on non-target organisms. Particularly, immune system dysregulation is a major concern due to the organism's increased vulnerability to diseases, including cancer development. Macrophages play essential roles in innate and adaptive immunity and can undergo classical (M1) or alternative (M2) activation. The M1 pro-inflammatory phenotype has an antitumor role, while M2 favors tumor promotion. Although previous studies have linked pesticide exposure to immune compromise, macrophage polarization is still poorly studied. Here, we investigated the effects of 72 h-long exposure to the mixture of four pesticides widely used in Brazil (glyphosate, 2,4-D, mancozeb, and atrazine), and their main metabolites (aminomethylphosphonic acid, 2,4-diclorophenol, ethylenethiourea, and desethylatrazine) on human leukemia monocytic THP-1 cell line at concentrations based on the Acceptable Daily Intake (ADI) value established in the country. The data revealed immunotoxicity related to impaired cell metabolism in all exposed groups, decreased cell attachment (Pes: 10^-1; Met: 10^-1; Mix: all concentrations), and disturbance in nitric oxide (NO) levels (Met: 10^-1, 10¹; Mix: all concentrations). The polarization of macrophages towards a more pro-tumor M2-like phenotype was also supported by decreased secretion of the pro-inflammatory cytokine TNF-α (Pes 10⁰, 10¹) and increased IL-8 (Pes 10¹). These outcomes alert about the risk of pesticide exposure in the Brazilian population.

The Immunomodulatory and Regenerative Effect of Biodentine™ on Human THP-1 Cells and Dental Pulp Stem Cells: In Vitro Study

Background

Pulp tissue affected by deep caries and trauma can be protected by vital pulp therapies in which pulp regeneration success depends on the degree of pulp inflammation and the presence of regenerative signals. Reparative dentinogenesis requires dental pulp stem cell (DPSC) activity which can be stimulated by many bioactive molecules to repair the dentine, mediating a balance between the inflammatory response and the reparative events. Therefore, this study was performed in order to investigate the immune-inflammatory effect of Biodentine capping material on DPSCs and macrophages.

Method

THP-1, a human monocytic cell line, was differentiated to macrophages, and flow cytometry was used to analyze the expressions of specific macrophage markers. LPS-mediated infection was created for macrophages and DPSCs followed by treatment with Biodentine. CBA array was used to investigate the cytokine secretion followed by qPCR. Migration potential of treated DPSCs was also determined.

Results

Our results showed that THP-1 cell line was successfully differentiated into macrophages as shown by surface marker expression. CBA array and qPCR results showed that Biodentine-treated DPSCs and macrophages upregulated anti-inflammatory cytokines and downregulated proinflammatory cytokines. Also, Biodentine enhances the migration potential of treated DPSCs.

Conclusion

Biodentine capping material mediated the polarization of M1 to M2 macrophages suggestive of tissue repair properties of macrophages and enhanced the anti-inflammatory cytokines of DPSCs responsible for dentine-pulp regeneration.