Desórdenes neurológicos

Conotoxins: Possible Therapeutic Measure for Huntingtons Disease

Abstract

Pallavi Bhosle and Sawarkar Vaibhav

Huntington’s disease (HD) is a genetic disorder with autosomal dominant inheritance with progressive degeneration of neurons. It is characterized by affective, cognitive, behavioral, and motor dysfunctions. 3 nitropropionic acid is well established animal model which initiates a complex series of neurochemical and signaling changes that lead to pathological events including neuronal excitotoxicity by excessive glutamate release, neuroinflammation and energy impairment. Excitotoxins like NMDA and kainic acid which binds to these receptors to release high levels of glutamate that can cause excitotoxicity by allowing high levels of calcium ions (Ca2+) to enter the cell. Ca2+ influx into cells activates a number of enzymes, including phospholipases, endonucleases, and proteases such as calpain. These enzymes increase apoptosis, oxidative stress and energy impairment thereby causing mitochondrial dysfunctions and go on to damage neuronal structures. The toxic venom used by the cone shells called conotoxin contains up to 50 different peptides that selectively inhibit the function of ion channels and excitatory amino acid receptors such as NMDA involved in the transmission of nerve signals in animals representing an extensive array of ion channel blockers each showing a high degree of selectivity for particular types of channels. Conotoxins selectively target a range of ion channels and NMDA receptors, making them widely useful tool for probing nervous system function. Here we hypothize the protective effect of conotoxins, from genus Conus geographus named w-conotoxin and conantoxin, against excitotoxic neuronal cell death using 3 NP induced Huntington’s model.