[SMC] AAV9-MEDIATED GENE THERAPY OF CHOLINE ACETYLTRANSFERASE DEFICIENT MICE

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Hum Gene Ther. 2024 Feb 1. doi: 10.1089/hum.2023.173. Online ahead of print.

ABSTRACT

The enzyme choline acetyltransferase (ChAT) synthesizes acetylcholine from acetyl-CoA and choline at the neuromuscular junction and at the nerve terminals of cholinergic neurons. Mutations in the ChAT gene (CHAT) result in a presynaptic congenital myasthenic syndrome (CMS) that often associates with life-threatening episodes of apnea. Knockout mice for Chat (Chat -/-) die at birth. To circumvent the lethality of this model, we crossed mutant mice possessing loxP sites flanking Chat exons 4 and 5 with mice that expressed Cre-ERT2. Injection of tamoxifen (Tx) at postnatal (P) day 11 life in these mice induced downregulation of Chat, autonomic failure, weakness, and death. However, a proportion of Chatflox/flox-Cre-ERT2 mice receiving at birth an intracerebroventricular injection of 2x1013 vg/kg adeno-associated virus type 9 (AAV9) carrying human CHAT (AAV9-CHAT) survived a subsequent tamoxifen injection and lived to adulthood without showing signs of weakness. Likewise, injection of AAV9-CHAT by intracisternal injection at P28 after the onset of weakness also resulted in survival to adulthood. The expression of Chat in spinal motor neurons of Chatflox/flox-Cre-ERT2 mice injected with Tx was markedly reduced, but AAV-injected mice showed a robust recovery of ChAT expression, which was mainly translated by the human CHATRNA. The biodistribution of the viral genome was widespread but maximal in the spinal cord and brain of AAV-injected mice. No significant histopathologic changes were observed in the brain, liver, and heart of AAV-injected mice after a follow-up of one year. Thus, AAV9-mediated gene therapy may provide an effective and safe treatment for patients severely affected with CHAT-CMS.

PMID:38299967 | DOI:10.1089/hum.2023.173


Source: https://pubmed.ncbi.nlm.nih.gov/3829996 ... 2&v=2.18.0