Mpzl2-KO Mouse

Mpzl2, encoding the epithelial junctional protein Myelin Protein Zero-like 2, is essential for hearing. It is an adhesion molecule mediating epithelial cell-cell interactions, and its function in the inner ear seems unique [5].

Mutations in Mpzl2 cause autosomal recessive non-syndromic hearing loss [1,2,4,5,6,7,8]. Patients typically show mild to moderate progressive hearing loss, with onset age varying from congenital to young adult stage [2,5,6]. In Chinese populations, the genetic load of Mpzl2 defects in hearing loss patients is 0.24% (8/3272), and 7.02% in patients with hereditary moderate sensorineural hearing loss caused by certain genes [2]. A mouse model with a deletion in the Mpzl2 gene displayed moderate and slowly progressive hearing loss, mimicking the human DFNB111 phenotype. Gene replacement therapy mediated by AAV-ie for Mpzl2-/-mice significantly lowered auditory thresholds and restored structural integrity in outer hair cells and Deiters cells, suggesting potential for treating Mpzl2-related deafness [3].

In conclusion, Mpzl2 is crucial for hearing. Studies on Mpzl2-deficient mouse models have revealed its role in maintaining the structural integrity of the inner ear and the progression of hearing loss. These findings provide valuable insights for understanding the mechanism of Mpzl2-related hearing loss and offer potential therapeutic strategies for this condition.