Histone deacetylase 2 and 3 of <i>Sarcoptes scabiei</i> : characterization of a potential drug target

Scabies is a contagious zoonotic parasitic disease that causes a substantial risk to both human and animal health and results in significant financial losses. No vaccine is available for scabies, and drug resistance to the conventional treatment for the disease has increased. Histone deacetylase (HDAC) modifies proteins by removing acetyl moieties from histones, regulates transcription, and is crucial for the immune system and apoptotic processes. This study aimed to clone, express, and determine the immunoreactivity of HDAC-2 and HDAC-3 of scabies mites to investigate their potential as scabies drug targets. The effects of inhibitors on recombinant <i>Sarcoptes scabiei</i> HDAC-2 (rSsHDAC-2) and rSsHDAC-3, as well as on the survival rate and ultrastructure of scabies mites <i>in vitro</i>, were also verified. The findings showed that the inhibitors reduced the acetylase activity of rSsHDAC-2 and rSsHDAC-3. Additionally, these inhibitors could significantly reduce the survival rate of scabies mites, making structural alterations in the mites such as mitochondrial pyknosis and cytoplasmic vacuoles and reaching a fatality rate of 76.7% after 24 h of action. In conclusion, HDAC-2 and HDAC-3 were critical to the survival of scabies mites and might be targeted by medications. Furthermore, the effect of inhibitors on the survival rate and structure of isolated scabies mites provides a new direction for developing therapeutic drugs for scabies.IMPORTANCEIn this study, we successfully cloned and expressed recombinant SsHDAC-2 and SsHDAC-3 in a prokaryotic system and confirmed their acetylation-deacetylase activities. These results provide a solid experimental foundation for subsequent research on SsHDAC-2 and SsHDAC-3. Furthermore, we report for the first time the use of SsHDAC-2 and SsHDAC-3 as drug targets. We demonstrated that the inhibition of these HDACs by pharmacological agents can lead to structural damage in the parasite, thereby impacting the survival activity of the scabies mite. This finding opens up a novel therapeutic avenue for the treatment of scabies.