category
bioRxiv
date
Feb 22, 2026
slug
status
Published
summary
首次构建两种RARB-RD突变小鼠模型,发现异质性突变导致纹状体Drd2神经元减少、运动协调障碍及认知损伤;通过转录组分析揭示RARB-RD变异与亨廷顿病共享 striatum 神经元存活机制,提出沉默致病等位基因的治疗策略。
tags
测序技术
基因编辑
type
Post
📄 原文题目
Compromised striatal structure and function in mouse models of RARB-related disorder
🔗 原文链接
💡 AI 核心解读
首次构建两种RARB-RD突变小鼠模型,发现异质性突变导致纹状体Drd2神经元减少、运动协调障碍及认知损伤;通过转录组分析揭示RARB-RD变异与亨廷顿病共享 striatum 神经元存活机制,提出沉默致病等位基因的治疗策略。
📝 英文原版摘要
Dominant variants in the retinoic acid receptor beta (RARB) gene cause a complex disorder known as RARB-related disorder (RARB-RD), characterized by multiple congenital anomalies, global developmental delay, and dystonia. RARB-RD variants have been classified as either gain-of-function (GOF) or dominant-negative (DN) based on their cell-based transcriptional responses to retinoids. To investigate the mechanisms underlying this disorder, we generated mouse models carrying either the p.R387C or p.L402P RARB-RD variant, previously categorized as GOF and DN, respectively. Homozygous mice for either RARB-RD variant died perinatally with colonic aganglionosis, while heterozygous mice survived and recapitulated several features of RARB-RD. In addition to microphthalmia, both RarbR387C/+ and RarbL402P/+ mice exhibited progressive coordination deficits, increased active-phase locomotor activity, and cognitive impairment in the novel object recognition test. In contrast, mice heterozygous for a null allele of Rarb (Rarb+/-) did not display these abnormalities. In the brain, Rarb is predominantly expressed in the two major populations of projection neurons of the striatum recognizable by the expression of dopamine receptors D1R/Drd1 and D2R/Drd2. Marker analysis revealed a reduction in Drd2-expressing neurons without changes in Drd1-expressing neurons in both RARB-RD models. Furthermore, RARB-RD mice showed partial resistance to the cataleptic effects of haloperidol, a D2R-specific antagonist. These behavioral, cellular, and dopaminergic deficits - though not the cognitive impairments - have previously been observed in Rarb-/- mice. To determine whether the in vitro effects of RARB-RD variants correlate with distinct transcriptional signatures in vivo, we compared the striatal tra
nscriptome of RarbR387C/+, RarbL402P/+, Rarb-/- and Rarb+/- mice with their littermate controls. We found that the heterozygous RARB-RD variants and the homozygous null allele affected a large subset of common genes, with putative direct RARB targets predominantly downregulated. Notably, the transcriptional impact of the RARB-RD variants was more profound than that of the null allele, regardless of zygosity. Additionally, transcriptional changes in RARB-RD mice extensively overlapped with those observed in mouse models of Huntington's disease, suggesting shared mechanisms affecting neuronal survival in the striatum. We conclude that the p.R387C and p.L402P variants similarly compromise striatal integrity and function, likely through a DN mechanism. Progressive emergence of most neurologic deficits highlights a potential therapeutic window. Our results support the development of strategies aimed at silencing RARB-RD alleles.
- 作者:NotionNext
- 链接:https://tangly1024.com/article/30f48bd6-1f96-8158-a6d6-ea801731b6cd
- 声明:本文采用 CC BY-NC-SA 4.0 许可协议,转载请注明出处。
相关文章
