Evaluation of gene-therapy as an alternative to pharmacological based approaches in mouse models of Rett syndrome
Year: 2019
Type: dissertation
Abstract: Rett syndrome (RTT) is a neurological disorder characterized by severe impairment of motor and cognitive functions, caused in >95 % of patients by de novo mutations in the X-linked gene, methyl-CpG-binding protein 2 (MECP2) gene.The protein product of this gene, MeCP2, is widely expressed but especially abundant in postmitotic neurons of the central nervous system (CNS).However, there remains a fundamental lack of knowledge about the downstream pathways involved in gene function.Both Mecp2 knock-out and knock-in mutant mice present many of the overt neurological features seen in RTT patients.Both provide a very useful model for testing potential therapeutic applications.The current lack of effective therapies together with the monogenicity of the disorder and established reversibility of the phenotype in mice suggest that replacement of the MECP2 gene is a potential therapeutic option worthy of exploration, mainly using viral based delivery of MECP2-based gene constructs.Significant challenges remain, both in the efficiency of delivery of gene constructs to target cells and controlling construct-derived toxicity.In this study, I have explored the potential for augmentation gene therapy in RTT mice.First, I determine the best RTT mouse model and modify behavioral tests for RTT mice in preparation for the experiment testing therapeutic agents.Second, I assessed escalating doses of viral vector containing human MECP2_e1 isoform coding sequences cloned into an AAV2 vector backbone with AAV9 capsid (scAAV9) under control of the murine Mecp2 endogenous core promoter (MeP229), a first generation vector, to ascertain the dose that has greater efficacy and lower toxicity after delivery to young adult Mecp2 knockout male mice.Third, I assess the safety and effectiveness of a new AAV vector construct design aiming to reduce the toxicity observed with the first-generation vector.This was carried out by direct brain injection in male neonates proving the efficacy of this vector.In the mouse behavioural studies, symptomatic hemizygous male and heterozygous female mice were used for assessment the two mouse models.The results demonstrated that in males, the Mecp2 knockout mouse model differed
Author: Vudhironarit, Thishnapha
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W3000209649