Tonabersat Significantly Reduces Disease Progression in an Experimental Mouse Model of Multiple Sclerosis

• Published in: International journal of molecular sciences Vol. 24; no. 24; p. 17454
• Main Authors: Kwakowsky, Andrea, Chawdhary, Bhavya, de Souza, Antonio, Meyer, Emily, Kaye, Andrew H, Green, Colin R, Stylli, Stanley S, Danesh-Meyer, Helen
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 14-12-2023
• Subjects: Adenosine triphosphate; Behavior; brain; Connexin 43; inflammasome; Multiple sclerosis; Neuropathology; Paralysis; tonabersat; Connexin 43; brain; tonabersat; inflammasome; multiple sclerosis
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms242417454

Multiple sclerosis (MS) is a neurodegenerative disease marked by chronic neuroinflammation thought to be mediated by the inflammasome pathway. Connexin 43 (Cx43) hemichannels contribute to the activation of the inflammasome through the release of adenosine triphosphate (ATP) inflammasome activation signals. The objective of the study was to evaluate if the Cx43 hemichannel blocker, tonabersat, is effective in modulating the inflammatory response and reducing disability in the myelin oligodendrocyte glycoprotein 35-55-induced experimental autoimmune encephalomyelitis (MOG
EAE) model of MS. Here, we show that the Cx43 hemichannel blocking drug, tonabersat, significantly reduced expression of neuroinflammatory markers for microglial activation (ionized calcium-binding adapter molecule 1 (Iba1)) and astrogliosis (glial fibrillary acidic protein (GFAP)) while preserving myelin basic protein (MBP) expression levels in the corpus callosum, motor cortex, and striatum regions of the brain in MOG
EAE mice. Reduced NOD-like receptor protein 3 (NLRP3) inflammasome complex assembly and Caspase-1 activation confirmed the drug's mode of action. MOG
EAE mice showed clinical signs of MS, but MOG
EAE mice treated with tonabersat retained behavior closer to normal. These data suggest that clinical trial phase IIb-ready tonabersat may merit further investigation as a promising candidate for MS treatment.