The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China.
Hum Gene Ther. 2023 Jun;34(11-12):567-577. doi: 10.1089/hum.2023.008. Epub 2023 May 17.
Dentin is a major type of hard tissue of teeth and plays essential roles for normal tooth function. Odontoblasts are responsible for dentin formation. Mutations or deficiency in various genes affect the differentiation of odontoblasts, leading to irreversible dentin developmental defects in animals and humans. Whether such dentin defects can be reversed by gene therapy for odontoblasts remains unknown. In this study, we compare the infection efficiencies of six commonly used adeno-associated virus (AAV) serotypes (AAV1, AAV5, AAV6, AAV8, AAV9, and AAVDJ) in cultured mouse odontoblast-like cells (OLCs). We show that AAV6 serotype infects OLCs with the highest efficiency among the six AAVs. Two cellular receptors, which are able to recognize AAV6, AAV receptor (AAVR), and epidermal growth factor receptor (EGFR), are strongly expressed in the odontoblast layer of mouse teeth. After local administration to mouse molars, AAV6 infects the odontoblast layer with high efficiency. Furthermore, AAV6-Mdm2 was successfully delivered to teeth and prevents the defects in odontoblast differentiation and dentin formation in conditional knockout mice (a mouse model of dentinogenesis imperfecta type Ⅲ). These results suggest that AAV6 can serve as a reliable and efficient vehicle for gene delivery to odontoblasts through local injection. In addition, human OLCs were also successfully infected by AAV6 with high efficiency, and both AAVR and EGFR are strongly expressed in the odontoblast layer of extracted human developing teeth. These findings suggest that AAV6-mediated gene therapy through local injection may be a promising treatment approach for hereditary dentin disorders in humans.
牙本质是牙齿的主要硬组织类型，对正常牙齿功能起着至关重要的作用。成牙本质细胞负责牙本质的形成。各种基因的突变或缺失会影响成牙本质细胞的分化，导致动物和人类的牙本质发育缺陷不可逆转。成牙本质细胞的基因治疗是否能逆转这种牙本质缺陷尚不清楚。在这项研究中，我们比较了六种常用腺相关病毒（AAV）血清型（AAV1、AAV5、AAV6、AAV8、AAV9 和 AAVDJ）在培养的小鼠成牙本质样细胞（OLC）中的感染效率。结果显示，AAV6 血清型在这六种 AAV 中对 OLC 的感染效率最高。两种能够识别 AAV6 的细胞受体，即 AAV 受体（AAVR）和表皮生长因子受体（EGFR），在小鼠牙齿的成牙本质细胞层中强烈表达。局部注射到小鼠磨牙后，AAV6 能高效感染成牙本质细胞层。此外，AAV6-Mdm2 成功递送至牙齿，并可预防条件性基因敲除小鼠（牙本质生成不全Ⅲ型的小鼠模型）中成牙本质细胞分化和牙本质形成的缺陷。这些结果表明，AAV6 可作为一种可靠、高效的载体，通过局部注射将基因递送至成牙本质细胞。此外，AAV6 也能高效感染人 OLC，AAVR 和 EGFR 在人发育牙齿的成牙本质细胞层中强烈表达。这些发现表明，通过局部注射 AAV6 介导的基因治疗可能是治疗人类遗传性牙本质疾病的一种有前途的方法。
