Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Control of redox homeostasis in tick blood feeding

Sabadin, Gabriela AlvesXavier, Marina AmaralVaz Junior, Itabajara da Silva

Introduction: Ticks are hematophagous ectoparasites that cause significate economical losses. Acaricide application is themain method to tick control. However, it causes environmental contamination and selects resistant ticks. The immunological control represents a suitable method to replace or complement acaricide application. During its life cycle, female ticksingest large amounts of blood, which contains toxic components able to damage biomolecules. Understanding which molecular mechanisms and proteins are involved in avoid damages caused by blood intake in ticks and other hematophagousarthropods could help to found potential candidate antigens to compose an anti-tick vaccine.Review: Hemoglobin comprises almost 20% of mammalian blood proteins, its hydrolysis during tick digestion increasestotal free heme that can potentially generate reactive oxygen species (ROS), which easily oxidize lipids, proteins and DNA,modifying they structure and function. Lipids are more susceptible to high ROS levels. It can lead to membrane instabilityand cell death. Protein modifications caused by ROS can promote the protein loss of function and cell disturbance, however,it can also work as post-translational modifications, acting in cell signaling processes. DNA presents more efficient protective mechanisms against ROS, but damages can lead to double helix rupture. Oxidative stress is defined as a disturbance inthe balance between the production and elimination of ROS, in favor of ROS production, leading to a disruption in redoxhomeostasis and/or molecular damage. Despite the well-recognized heme oxidative power and its already demonstratedcytotoxicity, ticks are able to feed on blood, controlling the redox homeostasis without causing oxidative stress. This occurs because ticks developed physiological adaptations to transport, store, metabolize and secrete toxic components fromthe diet. The strategies, such as heme compartmentalization in specialized organelles...(AU)

Texto completo