Browsing by Author "Liu, Xue Zhong"

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    Early Wnt Signaling Activation Promotes Inner Ear Differentiation via Cell Caudalization in Mouse Stem Cell-Derived Organoids
    (Oxford University Press, 2023) Tang, Pei-Ciao; Chen, Li; Singh, Sunita; Groves, Andrew K.; Koehler, Karl R.; Liu, Xue Zhong; Nelson, Rick F.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    The inner ear is derived from the otic placode, one of the numerous cranial sensory placodes that emerges from the pre-placodal ectoderm (PPE) along its anterior-posterior axis. However, the molecular dynamics underlying how the PPE is regionalized are poorly resolved. We used stem cell-derived organoids to investigate the effects of Wnt signaling on early PPE differentiation and found that modulating Wnt signaling significantly increased inner ear organoid induction efficiency and reproducibility. Alongside single-cell RNA sequencing, our data reveal that the canonical Wnt signaling pathway leads to PPE regionalization and, more specifically, medium Wnt levels during the early stage induce (1) expansion of the caudal neural plate border (NPB), which serves as a precursor for the posterior PPE, and (2) a caudal microenvironment that is required for otic specification. Our data further demonstrate Wnt-mediated induction of rostral and caudal cells in organoids and more broadly suggest that Wnt signaling is critical for anterior-posterior patterning in the PPE.
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    The natural history and genotype-phenotype correlations of TMPRSS3 hearing loss: an international, multi-center, cohort analysis
    (Springer, 2024) Colbert, Brett M.; Lanting, Cris; Smeal, Molly; Blanton, Susan; Dykxhoorn, Derek M.; Tang, Pei-Ciao; Getchell, Richard L.; Velde, Hedwig; Fehrmann, Mirthe; Thorpe, Ryan; Chapagain, Prem; Elkhaligy, Heidy; Kremer, Hannie; Yntema, Helger; Haer-Wigman, Lonneke; Redfield, Shelby; Sun, Tieqi; Bruijn, Saskia; Plomp, Astrid; Goderie, Thadé; van de Kamp, Jiddeke; Free, Rolien H.; Wassink-Ruiter, Jolien Klein; Widdershoven, Josine; Vanhoutte, Els; Rotteveel, Liselotte; Kriek, Marjolein; van Dooren, Marieke; Hoefsloot, Lies; de Gier, Heriette H. W.; DOOFNL Consortium; Schaefer, Amanda; Kolbe, Diana; Azaiez, Hela; Rabie, Grace; Aburayyan, Armal; Kawas, Mariana; Kanaan, Moien; Holder, Jourdan; Usami, Shin-Ichi; Chen, Zhengyi; Dai, Pu; Holt, Jeffrey; Nelson, Rick; Choi, Byung Yoon; Shearer, Eliot; Smith, Richard J. H.; Pennings, Ronald; Liu, Xue Zhong; Otolaryngology -- Head and Neck Surgery, School of Medicine
    TMPRSS3-related hearing loss presents challenges in correlating genotypic variants with clinical phenotypes due to the small sample sizes of previous studies. We conducted a cross-sectional genomics study coupled with retrospective clinical phenotype analysis on 127 individuals. These individuals were from 16 academic medical centers across 6 countries. Key findings revealed 47 unique TMPRSS3 variants with significant differences in hearing thresholds between those with missense variants versus those with loss-of-function genotypes. The hearing loss progression rate for the DFNB8 subtype was 0.3 dB/year. Post-cochlear implantation, an average word recognition score of 76% was observed. Of the 51 individuals with two missense variants, 10 had DFNB10 with profound hearing loss. These 10 all had at least one of 4 TMPRSS3 variants predicted by computational modeling to be damaging to TMPRSS3 structure and function. To our knowledge, this is the largest study of TMPRSS3 genotype-phenotype correlations. We find significant differences in hearing thresholds, hearing loss progression, and age of presentation, by TMPRSS3 genotype and protein domain affected. Most individuals with TMPRSS3 variants perform well on speech recognition tests after cochlear implant, however increased age at implant is associated with worse outcomes. These findings provide insight for genetic counseling and the on-going design of novel therapeutic approaches.