From the identification of a draggable target for the Olanzapine-induced Metabolic Syndrome to the development of a new therapeutic approach using CRISPR/Cas7-11S.

Metabolic Syndrome (MS) is a clinical condition characterized by multiple risk factors for cardiovascular diseases. Component features of MS include obesity, dyslipidemia, diabetes, and high blood pressure. Unbalanced diets, alcohol consumption, and reduced physical activity are the main risk factors for metabolic dysfunction. Moreover, MS represents one of the major side effects of commonly prescribed drugs like neuropsychiatric medications (antidepressants, antipsychotics, and mood stabilizers). Previously, using an unbiased approach, we identified the involvement of Histamine Receptor 1 (H1R) and Cannabinoid receptor 1 (CB1R) in the MS signature in hypothalamic gene expression in female mouse models of both diet and drug-induced MS. Here, we uncover the interplay between these two GPCRs in the pathophysiology of Olanzapine (OL) induced MS. Then, using the CRISPR-Cas9 approach, we demonstrate that the CB1R knockout in hypothalamic neurons is sufficient to reverse OL-induced MS while avoiding the side effects observed with Rimonabant treatment. This result underlines the need to develop a site-specific CB1R targeting therapy for MS. However, the stable changes in the genome using Cas9 as a therapeutic strategy in humans raise health concerns. To overcome this significant limitation and ensure a cell- and site-specific target of CB1R, the new RNA targeting CRISPR-Cas seems promising. Here, we developed a CRISPR-Cas7-11S toolbox for both in vitro and in vivo RNA targeting while designing and cloning spacer RNA sequences against CB1R RNA that would work for both human and mouse transcriptomes. Then, we screened the efficiency of CRISPR-Cas7-11S and single and multiple spacer RNAs compared with a non-targeting guide using the neuroblastoma cell lines. To provide a safety switch-off in case of undesired side effects of the CRISPR/Cas7-11S therapeutic system, the study aims to identify and test in vitro new ligands acting as cleavage breakers or complex formation inhibitors, arresting the enzymatic activity of CRISPR-Cas7-11S.