Screening and development of molecules targeting presynaptic SNARE protein-protein interactions as novel pharmacological strategy in schizophrenia and other mental illnesses

Screening and development of molecules targeting presynaptic SNARE protein-protein interactions as novel pharmacological strategy in schizophrenia and other mental illnesses Schizophrenia is one of the major disabling mental disorders with a worldwide prevalence of about one percent. Although the cause  of schizophrenia remains unclear, converging data indicate that dysfunctions altering neurotransmitter levels in the synaptic cleft, the tiny space between nerve cells in which nerve impulses are conducted, might be at the core of this disorder. In presynaptic cells, neurotransmitter release is governed by SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor).  Findings in the schizophrenic postmortem brain have revealed increased SNARE protein-protein interactions, which may explain the unbalanced neurotransmitter levels in schizophrenia, and reduced SNARE complexes in antipsychotic-treated patients. In accordance, genetic differences in SNARE-coding genes have been associated with schizophrenia.

Despite the growing evidence involving presynaptic dysfunction in mental illnesses, no attempts have been made to develop a pharmacological approach targeting the SNARE complex. Furthermore, the sole active agent against SNARE proteins, Botox cannot be used due to its irreversible, and lethal effects, presenting a challenge to finding SNARE-interfering compounds and pharmaceutically treating schizophrenia.

Against this background, the objective of Dr. Ramos-Miguel’s clinical research project is to find SNARE-interfering compounds, and further address their potential benefits in the pharmacological management of schizophrenia.

To meet this goal, an  agreement involving UBC, the Centre for Drug Research and Development (CDRD), and Roche-Canada, will allow Dr. Ramos-Miguel’s team to  screen the company's largest library, containing more than one million compounds. Additionally, an immunoassay-derived method has been automated for high throughput screening of compounds modifying SNARE interactions. This assay successfully screened the CDRD 26,000-compound library, and identified at least two SNARE "inhibitors". Further hits from the screening project will be subjected to a number of preclinical tests, including immunological, electrophysiological, toxicological and behavioral assays.

Identification of SNARE-interfering substances may have potential to improve pharmacological treatment of schizophrenia through a completely novel strategy.