lysosomal storage disease microglia mucopolysaccharidosis neurodegeneration stem cells
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摘要

Mucopolysaccharidosis IIIB is a paediatric lysosomal storage disease caused by deficiency of the enzyme α-N-acetylglucosaminidase (NAGLU), involved in the degradation of the glycosaminoglycan heparan sulphate. Absence of NAGLU leads to accumulation of partially degraded heparan sulphate within lysosomes and the extracellular matrix, giving rise to severe CNS degeneration with progressive cognitive impairment and behavioural problems. There are no therapies. Haematopoietic stem cell transplant shows great efficacy in the related disease mucopolysaccharidosis I, where donor-derived monocytes can transmigrate into the brain following bone marrow engraftment, secrete the missing enzyme and cross-correct neighbouring cells. However, little neurological correction is achieved in patients with mucopolysaccharidosis IIIB. We have therefore developed an ex vivo haematopoietic stem cell gene therapy approach in a mouse model of mucopolysaccharidosis IIIB, using a high-titre lentiviral vector and the myeloid-specific CD11b promoter, driving the expression of NAGLU (LV.NAGLU). To understand the mechanism of correction we also compared this with a poorly secreted version of NAGLU containing a C-terminal fusion to IGFII (LV.NAGLU-IGFII). Mucopolysaccharidosis IIIB haematopoietic stem cells were transduced with vector, transplanted into myeloablated mucopolysaccharidosis IIIB mice and compared at 8 months of age with mice receiving a wild-type transplant. As the disease is characterized by increased inflammation, we also tested the anti-inflammatory steroidal agent prednisolone alone, or in combination with LV.NAGLU, to understand the importance of inflammation on behaviour. NAGLU enzyme was substantially increased in the brain of LV.NAGLU and LV.NAGLU-IGFII-treated mice, with little expression in wild-type bone marrow transplanted mice. LV.NAGLU treatment led to behavioural correction, normalization of heparan sulphate and sulphation patterning, reduced inflammatory cytokine expression and correction of astrocytosis, microgliosis and lysosomal compartment size throughout the brain. The addition of prednisolone improved inflammatory aspects further. Substantial correction of lysosomal storage in neurons and astrocytes was also achieved in LV.NAGLU-IGFII-treated mice, despite limited enzyme secretion from engrafted macrophages in the brain. Interestingly both wild-type bone marrow transplant and prednisolone treatment alone corrected behaviour, despite having little effect on brain neuropathology. This was attributed to a decrease in peripheral inflammatory cytokines. Here we show significant neurological disease correction is achieved using haematopoietic stem cell gene therapy, suggesting this therapy alone or in combination with anti-inflammatories may improve neurological function in patients.

译文

粘多糖病 IIIB 是一种由 α-N-乙酰氨基葡萄糖苷酶 (NAGLU) 缺乏引起的儿童溶酶体贮存性疾病,该酶参与糖胺聚糖硫酸乙酰肝素的降解。NAGLU 的缺失导致部分降解的硫酸乙酰肝素在溶酶体和细胞外基质中的积累,导致严重的 CNS 退化,并伴有进行性认知障碍和行为问题。没有治疗方法。造血干细胞移植在相关疾病粘多糖症 I 中显示出巨大的疗效,在这种疾病中,供体来源的单核细胞可以在骨髓植入后迁移到大脑,分泌缺失的酶并交叉校正邻近细胞。然而,粘多糖病 IIIB 患者几乎没有神经矫正。因此,我们利用高滴度慢病毒载体和髓系特异性 CD11b 启动子,在粘多糖 IIIB 的小鼠模型中开发了一种体外造血干细胞基因治疗方法, 驱动 NAGLU 的表达 (LV。 NAGLU)。为了理解矫正的机制,我们还将其与分泌不良的 NAGLU 版本进行了比较,该版本包含了 IGFII 的 C 端融合 (LV.NAGLU-IGFII)。粘多糖症 IIIB 造血干细胞用载体转导,移植到清髓粘多糖症 IIIB 小鼠中,并在 8 个月大时与接受野生型移植的小鼠进行比较。由于这种疾病的特征是炎症增加,我们还单独或与 LV.NAGLU 联合测试了抗炎甾体制剂泼尼松龙,以了解炎症对行为的重要性。NAGLU 酶在 LV.NAGLU 和 LV.NAGLU-IGFII 处理的小鼠的大脑中显著增加,在野生型骨髓移植小鼠中很少表达。LV.NAGLU 治疗导致行为矫正、硫酸乙酰胆碱和硫酸化模式正常化、炎症细胞因子表达减少以及整个大脑星形细胞增多症、小胶质细胞增生和溶酶体隔室大小的矫正。泼尼松龙的加入进一步改善了炎症方面。尽管大脑中植入的巨噬细胞的酶分泌有限,但 LV.NAGLU-IGFII 处理的小鼠也实现了对神经元和星形胶质细胞中溶酶体储存的实质性校正。有趣的是,尽管对大脑神经病理学影响很小,但野生型骨髓移植和泼尼松龙单独治疗都纠正了行为。这归因于外周炎症细胞因子的减少。在这里,我们展示了使用造血干细胞基因疗法可以实现显著的神经疾病矫正,这表明这种疗法单独或与消炎药联合使用可以改善患者的神经功能。

Mucopolysaccharidosis

内分泌 代谢紊乱 疾病
概述  :  

黏多糖贮积病是一组代谢紊乱,是由分解称为糖胺聚糖(GAGs)分子所需的溶酶体酶的缺失或功能异常引起的。粘多糖贮积酶是溶酶体贮积病家族的一部分,溶酶体贮积病家族是由40多种遗传性疾病组成的群体,当动物细胞中的溶酶体细胞器发生故障时会导致这种疾病。溶酶体可以被认为是细胞的回收中心,因为它会将不需要的物质加工成细胞可以利用的其他物质。溶酶体通过酶(对生存至关重要的高度专门化的蛋白质)分解这种有害物质。当一种特定的酶的量太少或完全缺失时,就会引发溶酶体疾病,如粘多糖贮积症。临床表现粘多糖酶具有许多临

mucopolysaccharidosis   英 /'mju:kəu,pɔli,sækərai'dəusis/

释    义   n. 黏多糖病(指任何一种涉及黏多糖先天性代谢紊乱的疾病)

例    句   Objective To probe criteria for diagnosing mucopolysaccharidosis using X-ray.果糖的什么化学性质可以解释这两个观察事实?目的探讨粘多糖贮积症的X线诊断要点。

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