Overexpression of AScombined with the antibacterial monomer DMAHDM interferes with the VicRK two-component system to attenuate the cariogenicity of.

Abstract

BACKGROUND: () is a primary cariogenic pathogen responsible for acid production, exopolysaccharides (EPS) production and biofilm formation. Two-component systems (TCS) regulate EPS metabolism, especially the VicRK TCS. Overexpression of antisense(AS) can reduce EPS production and thereby weaken the cariogenicity ofAlthough the antimicrobial monomer dimethylaminohexadecyl methacrylate (DMAHDM) exhibits potent antibacterial properties, maturebiofilms can protect themselves by extracellular matrix. Emerging evidence suggests that genetic intervention enhances drug efficacy, yet the underlying regulatory mechanisms remain largely unexplored. OBJECTIVE: To investigate the chemical-genetic cooperative antibiofilm strategy inhibition and mechanisms of ASoverexpression combined with DMAHDM onbiofilm formation, acid and EPS metabolism, and cariogenicity through the VicRK system. METHODS: The minimal inhibitory concentration and minimal bactericidal concentration of DMAHDM and chlorhexidine were determined. Biofilm properties were evaluated via biomass assessment, EPS quantification, lactate production measurement, and colony-forming unit counting. Biofilm structures were examined by scanning electron microscopy. Mechanisms were investigated using RT-qPCR, zymography, and western blot. Rat caries model was employed to assess caries formation under different treatment conditions. RESULTS: The ASstrain exhibited an approximate 2-fold increase in susceptibility to DMAHDM and chlorhexidine. The combination treatment reduced biofilm CFU by approximately 4 log units, significantly lowered lactate and EPS levels, and resulted in a loose, porous biofilm structure. The expression levels of cariogenic virulence factors as well as the VicRK TCS genes and proteins were significantly downregulated., the combined treatment reduced the overall caries severity score to 12.7% of the control group (p<0.05) without observing any systemic adverse effects. CONCLUSION: The strategy of combining ASoverexpression with DMAHDM effectively modulates EPS metabolism and cariogenicity inby interfering with the VicRK TCS, providing a potential therapeutic approach for clinical caries management.