CHD7 regulates otic lineage differentiation and deafness gene expression in human inner ear organoids

2021 ◽  
Author(s):  
Jing Nie ◽  
Yoshitomo Ueda ◽  
Alexander Solivais ◽  
Eri Hashino
Keyword(s):  
Gene Expression ◽  
Inner Ear ◽  
Chromatin Remodeling ◽  
Hair Cells ◽  
Critical Role ◽  
Transcriptome Profiling ◽  
Underlying Mechanism ◽  
Lineage Differentiation ◽  
Deafness Gene ◽  
Human Inner Ear

Abstract Mutations in the chromatin remodeling enzyme CHD7 cause CHARGE syndrome, which affects multiple organs including the inner ear. We investigated how CHD7 mutations affect otic development in human inner ear organoids. We found loss of CHD7 or its chromatin remodeling activity leads to complete absence of hair cells and supporting cells, which can be explained by dysregulation of key otic development-associated genes in mutant otic progenitors. Further analysis of the mutant otic progenitors suggested that CHD7 can regulate otic genes through a chromatin remodeling-independent mechanism. Results from transcriptome profiling of hair cells revealed disruption of deafness gene expression as a potential underlying mechanism of CHARGE-associated sensorineural hearing loss. Notably, co-differentiating CHD7 knockout and wild-type cells in chimeric organoids partially rescued mutant phenotypes by restoring otherwise severely dysregulated otic genes. Taken together, our results suggest that CHD7 plays a critical role in regulating human otic lineage differentiation and deafness gene expression.

scholarly journals Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos

2021 ◽  
Vol 22 (12) ◽  
pp. 6497
Author(s):  
Anna Ghilardi ◽  
Alberto Diana ◽  
Renato Bacchetta ◽  
Nadia Santo ◽  
Miriam Ascagni ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Hair Cells ◽  
Muscle Fibers ◽  
Underlying Mechanism ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Developmental Defects ◽  
Inner Ear Development ◽  
Syndromic Hearing Loss

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.

scholarly journals LSD1, a double-edged sword, confers dynamic chromatin regulation but commonly promotes aberrant cell growth

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2016 ◽  
Author(s):  
Meghan M Kozub ◽  
Ryan M Carr ◽  
Gwen L Lomberk ◽  
Martin E Fernandez-Zapico
Keyword(s):  
Gene Expression ◽  
Chromatin Remodeling ◽  
Cellular Differentiation ◽  
Critical Role ◽  
Histone Demethylase ◽  
Epigenetic Changes ◽  
Lysine Specific Demethylase ◽  
Wide Range ◽  
Histone Modifying Enzymes

Histone-modifying enzymes play a critical role in chromatin remodeling and are essential for influencing several genome processes such as gene expression and DNA repair, replication, and recombination. The discovery of lysine-specific demethylase 1 (LSD1), the first identified histone demethylase, dramatically revolutionized research in the field of epigenetics. LSD1 plays a pivotal role in a wide range of biological operations, including development, cellular differentiation, embryonic pluripotency, and disease (for example, cancer). This mini-review focuses on the role of LSD1 in chromatin regulatory complexes, its involvement in epigenetic changes throughout development, and its importance in physiological and pathological processes.

scholarly journals The ATP-dependent chromatin remodeling enzyme CHD7 regulates pro-neural gene expression and neurogenesis in the inner ear

Development ◽  
2010 ◽  
Vol 137 (18) ◽  
pp. 3139-3150 ◽  
Author(s):  
E. A. Hurd ◽  
H. K. Poucher ◽  
K. Cheng ◽  
Y. Raphael ◽  
D. M. Martin
Keyword(s):  
Gene Expression ◽  
Inner Ear ◽  
Chromatin Remodeling

scholarly journals Direct SARS-CoV-2 infection of the human inner ear may underlie COVID-19-associated audiovestibular dysfunction

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Minjin Jeong ◽  
Karen E. Ocwieja ◽  
Dongjun Han ◽  
P. Ashley Wackym ◽  
Yichen Zhang ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hair Cells ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Induced Pluripotent Stem Cell ◽  
In Vitro Models ◽  
Cellular Models ◽  
Induced Pluripotent ◽  
Human Inner Ear

Abstract Background COVID-19 is a pandemic respiratory and vascular disease caused by SARS-CoV-2 virus. There is a growing number of sensory deficits associated with COVID-19 and molecular mechanisms underlying these deficits are incompletely understood. Methods We report a series of ten COVID-19 patients with audiovestibular symptoms such as hearing loss, vestibular dysfunction and tinnitus. To investigate the causal relationship between SARS-CoV-2 and audiovestibular dysfunction, we examine human inner ear tissue, human inner ear in vitro cellular models, and mouse inner ear tissue. Results We demonstrate that adult human inner ear tissue co-expresses the angiotensin-converting enzyme 2 (ACE2) receptor for SARS-CoV-2 virus, and the transmembrane protease serine 2 (TMPRSS2) and FURIN cofactors required for virus entry. Furthermore, hair cells and Schwann cells in explanted human vestibular tissue can be infected by SARS-CoV-2, as demonstrated by confocal microscopy. We establish three human induced pluripotent stem cell (hiPSC)-derived in vitro models of the inner ear for infection: two-dimensional otic prosensory cells (OPCs) and Schwann cell precursors (SCPs), and three-dimensional inner ear organoids. Both OPCs and SCPs express ACE2, TMPRSS2, and FURIN, with lower ACE2 and FURIN expression in SCPs. OPCs are permissive to SARS-CoV-2 infection; lower infection rates exist in isogenic SCPs. The inner ear organoids show that hair cells express ACE2 and are targets for SARS-CoV-2. Conclusions Our results provide mechanistic explanations of audiovestibular dysfunction in COVID-19 patients and introduce hiPSC-derived systems for studying infectious human otologic disease.

scholarly journals Hairless is a nuclear receptor corepressor essential for skin function

2009 ◽  
Vol 7 (1) ◽  
pp. nrs.07010 ◽  
Author(s):  
Catherine C. Thompson
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Nuclear Receptors ◽  
Chromatin Remodeling ◽  
Transcriptional Repression ◽  
Critical Role ◽  
Epithelial Stem Cells ◽  
Skin Function

The activity of nuclear receptors is modulated by numerous coregulatory factors. Corepressors can either mediate the ability of nuclear receptors to repress transcription, or can inhibit transactivation by nuclear receptors. As we learn more about the mechanisms of transcriptional repression, the importance of repression by nuclear receptors in development and disease has become clear. The protein encoded by the mammalian Hairless (Hr) gene was shown to be a corepressor by virtue of its functional similarity to the well-established corepressors N-CoR and SMRT. Mutation of the Hr gene results in congenital hair loss in both mice and men. Investigation of Hairless function both in vitro and in mouse models in vivo has revealed a critical role in maintaining skin and hair by regulating the differentiation of epithelial stem cells, as well as a putative role in regulating gene expression via chromatin remodeling.

The mouse Snell's waltzer deafness gene encodes an unconventional myosin required for structural integrity of inner ear hair cells

1995 ◽  
Vol 11 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Karen B. Avraham ◽  
Tama Hasson ◽  
Karen P. Steel ◽  
David M. Kingsley ◽  
Liane B. Russell ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hair Cells ◽  
Structural Integrity ◽  
Unconventional Myosin ◽  
Deafness Gene

scholarly journals Barhl1 Regulatory Sequences Required for Cell-Specific Gene Expression and Autoregulation in the Inner Ear and Central Nervous System

2008 ◽  
Vol 28 (6) ◽  
pp. 1905-1914 ◽  
Author(s):  
Ramesh Chellappa ◽  
Shengguo Li ◽  
Sarah Pauley ◽  
Israt Jahan ◽  
Kangxin Jin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Central Nervous System ◽  
Nervous System ◽  
Inner Ear ◽  
Hair Cells ◽  
Cerebellar Granule Cells ◽  
Sensory Cells ◽  
Specific Gene ◽  
Regulatory Sequences ◽  
Specific Gene Expression

ABSTRACT The development of the nervous system requires the concerted actions of multiple transcription factors, yet the molecular events leading to their expression remain poorly understood. Barhl1, a mammalian homeodomain transcription factor of the BarH class, is expressed by developing inner ear hair cells, cerebellar granule cells, precerebellar neurons, and collicular neurons. Targeted gene inactivation has demonstrated a crucial role for Barhl1 in the survival and/or migration of these sensory cells and neurons. Here we report the regulatory sequences of Barhl1 necessary for directing its proper spatiotemporal expression pattern in the inner ear and central nervous system (CNS). Using a transgenic approach, we have found that high-level and cell-specific expression of Barhl1 within the inner ear and CNS depends on both its 5′ promoter and 3′ enhancer sequences. Further transcriptional, binding, and mutational analyses of the 5′ promoter have identified two homeoprotein binding motifs that can be occupied and activated by Barhl1. Moreover, proper Barhl1 expression in inner ear hair cells and cerebellar and precerebellar neurons requires the presence of Atoh1. Together, these data delineate useful Barhl1 regulatory sequences that direct strong and specific gene expression to inner ear hair cells and CNS sensory neurons, establish a role for autoregulation in the maintenance of Barhl1 expression, and identify Atoh1 as a key upstream regulator.

Transcriptome profiling reveals an IAA-regulated response to adventitious root formation in lotus seedling

2018 ◽  
Vol 73 (5-6) ◽  
pp. 229-240 ◽  
Author(s):  
Cheng Libao ◽  
Jiang Runzhi ◽  
Yang Jianjun ◽  
Xu Xiaoyong ◽  
Zeng Haitao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Root Formation ◽  
Molecular Level ◽  
Critical Role ◽  
Transcriptome Profiling ◽  
Adventitious Root Formation ◽  
Transcriptional Level ◽  
Comprehensive Understanding ◽  
Sequencing Technique ◽  
Indole 3 Acetic Acid

AbstractAdventitious roots (ARs) of lotus (NelumbonuciferaGaertn.) play a critical role in water and nutrient uptake. We found that exogenously applied 10-μM indole-3-acetic acid (IAA) promoted the formation of ARs, while 150-μM IAA significantly inhibited the emergence of ARs. However, little is known about these different responses to various concentrations of IAA at the molecular level. This study, therefore, examined the gene expression profiling in four libraries treated with 10- and 150-μM IAA based on the high-throughout tag sequencing technique. Approximately 2.4×107clean tags were obtained after the removal of low-quality tags from each library respectively, among which about 10% clean tags were unambiguous tag-mapped genes to the reference genes. We found that some genes involved in auxin metabolism showed a similar tendency for expression in the A/CK and C/CK libraries, while three genes were enhanced their expression only in the A/CK libraries. Two transcription factors including B3 domain-containing protein At2g36080-like and trihelix transcription factor were up-regulated for transcriptional level in the A/C libraries. The expressions of six important genes related to AR formation were significantly different in the A/CK and C/CK libraries. In summary, this study provides a comprehensive understanding of gene expression regulated by IAA involved in AR formation in lotus.

scholarly journals Gfi1-Foxo1 axis controls the fidelity of effector gene expression and developmental maturation of thymocytes

2016 ◽  
Vol 114 (1) ◽  
pp. E67-E74 ◽  
Author(s):  
Lewis Zhichang Shi ◽  
Jordy Saravia ◽  
Hu Zeng ◽  
Nishan S. Kalupahana ◽  
Clifford S. Guy ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Underlying Mechanism ◽  
Cell Receptor ◽  
Gene Expression Program ◽  
Double Positive ◽  
Lineage Differentiation ◽  
Tcr Signals ◽  
Expression Program ◽  
Developmental Maturation

Double-positive (DP) thymocytes respond to intrathymic T-cell receptor (TCR) signals by undergoing positive selection and lineage differentiation into single-positive (SP) mature cells. Concomitant with these well-characterized events is the acquisition of a mature T-cell gene expression program characterized by the induction of the effector molecules IL-7Rα, S1P1, and CCR7, but the underlying mechanism remains elusive. We report here that transcription repressor Growth factor independent 1 (Gfi1) orchestrates the fidelity of the DP gene expression program and developmental maturation into SP cells. Loss of Gfi1 resulted in premature induction of effector genes and the transcription factors forkhead box protein O1 (Foxo1) and Klf2 in DP thymocytes and the accumulation of postselection intermediate populations and accelerated transition into SP cells. Strikingly, partial loss of Foxo1 function, but not restored survival fitness, rectified the dysregulated gene expression and thymocyte maturation in Gfi1-deficient mice. Our results establish the Gfi1-Foxo1 axis and the transcriptional circuitry that actively maintain DP identity and shape the proper generation of mature T cells.

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