AUTHOR=Zhang Shasha , Dong Ying , Qiang Ruiying , Zhang Yuan , Zhang Xiaoli , Chen Yin , Jiang Pei , Ma Xiangyu , Wu Leilei , Ai Jingru , Gao Xia , Wang Pengjun , Chen Jie , Chai Renjie 

TITLE=Characterization of Strip1 Expression in Mouse Cochlear Hair Cells

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.625867

DOI=10.3389/fgene.2021.625867

ISSN=1664-8021

ABSTRACT=<p>Striatin-interacting protein 1 (<italic>Strip1</italic>) is a core component of the striatin interacting phosphatase and kinase (STRIPAK) complex, which is involved in embryogenesis and development, circadian rhythms, type 2 diabetes, and cancer progression. However, the expression and role of <italic>Strip1</italic> in the mammalian cochlea remains unclear. Here we studied the expression and function of <italic>Strip1</italic> in the mouse cochlea by using <italic>Strip1</italic> knockout mice. We first found that the mRNA and protein expression of <italic>Strip1</italic> increases as mice age starting from postnatal day (P) 3 and reaches its highest expression level at P30 and that the expression of <italic>Strip1</italic> can be detected by immunofluorescent staining starting from P14 only in cochlear HCs, and not in supporting cells (SCs). Next, we crossed <italic>Strip1</italic> heterozygous knockout (<italic>Strip</italic> +/−) mice to obtain <italic>Strip1</italic> homozygous knockout (<italic>Strip1</italic>−/−) mice for studying the role of <italic>Strip1</italic> in cochlear HCs. However, no <italic>Strip1</italic>−/− mice were obtained and the ratio of <italic>Strip</italic> +/− to <italic>Strip1</italic>+/+ mice per litter was about 2:1, which suggested that homozygous <italic>Strip1</italic> knockout is embryonic lethal. We measured hearing function and counted the HC number in P30 and P60 <italic>Strip</italic> +/− mice and found that they had normal hearing ability and HC numbers compared to <italic>Strip1</italic>+/+ mice. Our study suggested that <italic>Strip1</italic> probably play important roles in HC development and maturation, which needs further study in the future.</p>