Characterization of a knock-in mouse model of the homozygous p.V37I variant in Gjb2.
The homozygous p.V37I variant in GJB2 is prevalent in East and Southeast Asians and may lead to mild-to-moderate hearing loss with reduced penetrance. To investigate the pathogenic mechanism underlying this variant, we generated a knock-in mouse model of homozygous p.V37I by an embryonic stem cell gene targeting method. Auditory brainstem response test showed that the knock-in mice developed progressive, mild-to-moderate hearing loss over the first 4-9 months. Overall no significant developmental and morphological abnormality was observed in the knock-in mouse cochlea, while confocal immunostaining and electron microscopic scanning revealed minor loss of the outer hair cells. Gene expression microarray analysis identified 105 up-regulated and 43 down-regulated genes in P5 knock-in mouse cochleae (P < 0.05 adjusted by the Benjamini &Hochberg method), among which four top candidate genes with the highest fold-changes or implication to deafness Fcer1g, Nnmt and Lars2 and Cuedc1 were verified by quantitative real-time PCR. Our study demonstrated that the homozygous p.V37I knock-in mouse modeled the hearing phenotype of the human patients and can serve as a useful animal model for further studies. The differentially expressed genes identified in this study may shed new insights into the understanding of the pathogenic mechanism and the phenotypic modification of homozygous p.V37I.
Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.|Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Ying
Y
Chen
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Lingxiang
L
Hu
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Xueling
X
Wang
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Changling
C
Sun
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Xin
X
Lin
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Lei
L
Li
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Ling
L
Mei
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Zhiwu
Z
Huang
Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Tao
T
Yang
Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.|Ear Institute, Shanghai Jiaotong University, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.|Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Hao
H
Wu
D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics; D000818:Animals; D044466:Asian People; D003051:Cochlea / Q000473:pathology / Q000648:ultrastructure; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D053595:Embryonic Stem Cells / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D055879:Gene Knock-In Techniques; D034381:Hearing Loss / Q000235:genetics* / Q000503:physiopathology; D006320:Hearing Tests; D006801:Humans; D051379:Mice; D046228:Microarray Analysis; D009154:Mutation; D050903:Nicotinamide N-Methyltransferase / Q000235:genetics; D011961:Receptors, Fc / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics
C576361:CUEDC2 protein, mouse; D017630:Connexins; C000622314:FCER1G, human; C000607042:GJB2 protein, human; C000607043:Gjb2 protein, mouse; D011961:Receptors, Fc; D012097:Repressor Proteins; D000072259:Connexin 26; D050903:Nicotinamide N-Methyltransferase; C494407:Nnmt protein, mouse; D000604:Amino Acyl-tRNA Synthetases; C549096:LARS2 protein, human