scholarly journals Par3 regulates Rac1 signaling and microtubule organization during planar polarization of auditory hair cells

2018 ◽  
Author(s):  
Andre Landin Malt ◽  
Zachary Dailey ◽  
Julia Holbrook-rasmussen ◽  
Yuqiong Zheng ◽  
Quansheng Du ◽  
...  
Keyword(s):  
Inner Ear ◽  
Cell Polarity ◽  
Hair Cells ◽  
Planar Cell Polarity ◽  
Tissue Level ◽  
Hair Bundle ◽  
Microtubule Organization ◽  
Reciprocal Regulation ◽  
Auditory Hair Cells ◽  
Pcp Signaling

AbstractIn the inner ear sensory epithelia, hair bundles atop sensory hair cells are mechanosensory apparati with planar polarized structure and orientation. This is established during development by the concerted action of tissue-level planar cell polarity (PCP) signaling and a hair cell-intrinsic, microtubule-mediated machinery. However, how various polarity signals are integrated during hair bundle morphogenesis is poorly understood. Here, we show that the conserved cell polarity protein Par3 plays a key role in planar polarization of hair cells. Par3 deletion in the inner ear resulted in defects in cochlear length, hair bundle orientation and kinocilium positioning. During PCP establishment, Par3 promotes localized Rac-Pak signaling through an interaction with Tiam1. Par3 regulates microtubule dynamics and organization, which is crucial for basal body positioning. Moreover, there is reciprocal regulation of Par3 and the core PCP molecule Vangl2. Thus, we conclude that Par3 is an effector and integrator of cell-intrinsic and tissue-level PCP signaling.One sentence summaryPar3 regulates planar polarity of auditory hair cells

scholarly journals Par3 is essential for the establishment of planar cell polarity of inner ear hair cells

2019 ◽  
Vol 116 (11) ◽  
pp. 4999-5008 ◽  
Author(s):  
Andre Landin Malt ◽  
Zachary Dailey ◽  
Julia Holbrook-Rasmussen ◽  
Yuqiong Zheng ◽  
Arielle Hogan ◽  
...  
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Cell Polarity ◽  
Hair Cells ◽  
Planar Cell Polarity ◽  
Tissue Level ◽  
Hair Bundle ◽  
Nucleotide Exchange ◽  
Genetic Mosaic ◽  
Pcp Signaling

In the inner ear sensory epithelia, stereociliary hair bundles atop sensory hair cells are mechanosensory apparatus with planar polarized structure and orientation. This is established during development by the concerted action of tissue-level, intercellular planar cell polarity (PCP) signaling and a hair cell-intrinsic, microtubule-mediated machinery. However, how various polarity signals are integrated during hair bundle morphogenesis is poorly understood. Here, we show that the conserved cell polarity protein Par3 is essential for planar polarization of hair cells. Par3 deletion in the inner ear disrupted cochlear outgrowth, hair bundle orientation, kinocilium positioning, and basal body planar polarity, accompanied by defects in the organization and cortical attachment of hair cell microtubules. Genetic mosaic analysis revealed that Par3 functions both cell-autonomously and cell-nonautonomously to regulate kinocilium positioning and hair bundle orientation. At the tissue level, intercellular PCP signaling regulates the asymmetric localization of Par3, which in turn maintains the asymmetric localization of the core PCP protein Vangl2. Mechanistically, Par3 interacts with and regulates the localization of Tiam1 and Trio, which are guanine nucleotide exchange factors (GEFs) for Rac, thereby stimulating Rac-Pak signaling. Finally, constitutively active Rac1 rescued the PCP defects in Par3-deficient cochleae. Thus, a Par3–GEF–Rac axis mediates both tissue-level and hair cell-intrinsic PCP signaling.

scholarly journals Ick Ciliary Kinase Is Essential for Planar Cell Polarity Formation in Inner Ear Hair Cells and Hearing Function

2017 ◽  
Vol 37 (8) ◽  
pp. 2073-2085 ◽  
Author(s):  
Shio Okamoto ◽  
Taro Chaya ◽  
Yoshihiro Omori ◽  
Ryusuke Kuwahara ◽  
Shun Kubo ◽  
...  
Keyword(s):  
Inner Ear ◽  
Cell Polarity ◽  
Hair Cells ◽  
Planar Cell Polarity ◽  
Hearing Function

scholarly journals Coupling Planar Cell Polarity Signaling to Morphogenesis

2002 ◽  
Vol 2 ◽  
pp. 434-454 ◽  
Author(s):  
Jeffrey D. Axelrod ◽  
Helen McNeill
Keyword(s):  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Fruit Fly ◽  
Convergent Extension ◽  
Cytoskeletal Reorganization ◽  
Directional Information ◽  
Cochlear Hair Cell ◽  
Cellular Asymmetry ◽  
Pcp Signaling ◽  
Unknown Signal

Epithelial cells and other groups of cells acquire a polarity orthogonal to their apical–basal axes, referred to as Planar Cell Polarity (PCP). The process by which these cells become polarized requires a signaling pathway using Frizzled as a receptor. Responding cells sense cues from their environment that provide directional information, and they translate this information into cellular asymmetry. Most of what is known about PCP derives from studies in the fruit fly,Drosophila. We review what is known about how cells translate an unknown signal into asymmetric cytoskeletal reorganization. We then discuss how the vertebrate processes of convergent extension and cochlear hair-cell development may relate toDrosophilaPCP signaling.

scholarly journals Non-Canonical Wnt Signaling Regulates Cochlear Outgrowth and Planar Cell Polarity via Gsk3β Inhibition

2021 ◽  
Vol 9 ◽  
Author(s):  
Andre Landin Malt ◽  
Shaylyn Clancy ◽  
Diane Hwang ◽  
Alice Liu ◽  
Connor Smith ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Small Gtpase ◽  
Hair Bundle ◽  
Apical Surface ◽  
Canonical Wnt Signaling ◽  
Genetic Rescue ◽  
Genetic Ablation ◽  
Canonical Wnt

During development, sensory hair cells (HCs) in the cochlea assemble a stereociliary hair bundle on their apical surface with planar polarized structure and orientation. We have recently identified a non-canonical, Wnt/G-protein/PI3K signaling pathway that promotes cochlear outgrowth and coordinates planar polarization of the HC apical cytoskeleton and alignment of HC orientation across the cochlear epithelium. Here, we determined the involvement of the kinase Gsk3β and the small GTPase Rac1 in non-canonical Wnt signaling and its regulation of the planar cell polarity (PCP) pathway in the cochlea. We provided the first in vivo evidence for Wnt regulation of Gsk3β activity via inhibitory Ser9 phosphorylation. Furthermore, we carried out genetic rescue experiments of cochlear defects caused by blocking Wnt secretion. We showed that cochlear outgrowth was partially rescued by genetic ablation of Gsk3β but not by expression of stabilized β-catenin; while PCP defects, including hair bundle polarity and junctional localization of the core PCP proteins Fzd6 and Dvl2, were partially rescued by either Gsk3β ablation or constitutive activation of Rac1. Our results identify Gsk3β and likely Rac1 as downstream components of non-canonical Wnt signaling and mediators of cochlear outgrowth, HC planar polarity, and localization of a subset of core PCP proteins in the cochlea.

scholarly journals SHROOM3 is a novel component of the planar cell polarity pathway whose disruption causes congenital heart disease

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Alison Schmidt ◽  
Matthew Durbin, MS MD ◽  
James O’Kane, MS ◽  
Stephanie M. Ware, MD PHD
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Signaling Pathway ◽  
Cell Polarity ◽  
Congenital Heart ◽  
Planar Cell Polarity ◽  
Cardiac Development ◽  
Genetic Interaction ◽  
Compound Heterozygous ◽  
Pcp Signaling

Congenital heart disease (CHD) is the most common cause of death due to birth defects. Despite CHD frequency, the etiology remains mostly unknown. Understanding CHD genetics and elucidating disease mechanism will help establish prognosis, identify comorbidity risks, and develop targeted therapies. CHD often results from disrupted cytoarchitecture and signaling pathways. We have identified a novel CHD candidate SHROOM3, a protein associated with the actin cytoskeleton and the Wnt/Planar Cell Polarity (PCP) signaling pathway. SHROOM3 induces actomyosin constriction within the apical side of cells and is implicated in neural tube defects and chronic renal failure in humans. A recent study demonstrated that SHROOM3 interacts with Dishevelled2 (DVL2), a component of the PCP signaling pathway, suggesting that SHROOM3 serves as an important link between acto-myosin constriction and PCP signaling. PCP signaling establishes cell polarity required for multiple developmental processes, and is required for cardiac development. In Preliminary data we utilized a Shroom3 gene-trap mouse (Shroom3gt/gt) to demonstrated that SHROOM3 disruption leads to cardiac defects phenocopy PCP disruption. We also demonstrate that patients with CHD phenotypes have rare and potentially damaging SHROOM3 variants within SHROOM3’s PCP-binding domain. We hypothesize SHROOM3 is a novel terminal effector of PCP signaling, and disruption is a novel contributor to CHD. To test this, we assessed genetic interaction between SHROOM3 and PCP during cardiac development and the ultimate effect on cell structure and movement. Heterozygous Shroom3+/gt mice and heterozygous Dvl2 +/- mice are phenotypically normal. We demonstrated genetic interaction between SHROOM3 and PCP signaling by generating compound heterozygous Shroom3+/gt ;Dvl2 +/- mice and identifying a Double Outlet Right Ventricle and Ventricular Septal Defect in one embryo. We also observed fewer compound heterozygous mice than anticipated by Mendelian rations (observed: 18.4%; expected: 25%; n=76), suggesting potential lethality in utero. Immunohistochemistry demonstrates disrupted actomyosin in the SHROOM3gt/gt mice, characteristic of PCP disruption. These data help strengthen SHROOM3 as a novel CHD candidate gene and a component of the PCP Signaling pathway. Further characterization of this gene is important for CHD diagnosis and therapeutic development.

scholarly journals Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear

2014 ◽  
Vol 395 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Chonnettia Jones ◽  
Dong Qian ◽  
Sun Myoung Kim ◽  
Shuangding Li ◽  
Dongdong Ren ◽  
...  
Keyword(s):  
Inner Ear ◽  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Functional Homolog ◽  
Polarity Gene

scholarly journals Generation of Cochlear Hair Cells from Sox2 Positive Supporting Cells via DNA Demethylation

2020 ◽  
Vol 21 (22) ◽  
pp. 8649
Author(s):  
Xin Deng ◽  
Zhengqing Hu
Keyword(s):  
Transgenic Mice ◽  
Inner Ear ◽  
Hair Cells ◽  
Dna Methyltransferase ◽  
Dna Demethylation ◽  
Egfp Expression ◽  
Supporting Cells ◽  
Cochlear Hair Cells ◽  
Auditory Hair Cells ◽  
Adult Mice

Regeneration of auditory hair cells in adult mammals is challenging. It is also difficult to track the sources of regenerated hair cells, especially in vivo. Previous paper found newly generated hair cells in deafened mouse by injecting a DNA methyltransferase inhibitor 5-azacytidine into the inner ear. This paper aims to investigate the cell sources of new hair cells. Transgenic mice with enhanced green fluorescent protein (EGFP) expression controlled by the Sox2 gene were used in the study. A combination of kanamycin and furosemide was applied to deafen adult mice, which received 4 mM 5-azacytidine injection into the inner ear three days later. Mice were followed for 3, 5, 7 and 14 days after surgery to track hair cell regeneration. Immunostaining of Myosin VIIa and EGFP signals were used to track the fate of Sox2-expressing supporting cells. The results show that (i) expression of EGFP in the transgenic mice colocalized the supporting cells in the organ of Corti, and (ii) the cell source of regenerated hair cells following 5-azacytidine treatment may be supporting cells during 5–7 days post 5-azacytidine injection. In conclusion, 5-azacytidine may promote the conversion of supporting cells to hair cells in chemically deafened adult mice.

scholarly journals Planar Cell Polarity Signaling Pathway in Congenital Heart Diseases

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Gang Wu ◽  
Jiao Ge ◽  
Xupei Huang ◽  
Yimin Hua ◽  
Dezhi Mu
Keyword(s):  
Signaling Pathway ◽  
Cell Polarity ◽  
Congenital Heart ◽  
Planar Cell Polarity ◽  
Heart Diseases ◽  
Multiple Roles ◽  
Cardiac Differentiation ◽  
Tissue Polarity ◽  
Cardiac Disorder ◽  
Pcp Signaling

Congenital heart disease (CHD) is a common cardiac disorder in humans. Despite many advances in the understanding of CHD and the identification of many associated genes, the fundamental etiology for the majority of cases remains unclear. The planar cell polarity (PCP) signaling pathway, responsible for tissue polarity inDrosophilaand gastrulation movements and cardiogenesis in vertebrates, has been shown to play multiple roles during cardiac differentiation and development. The disrupted function of PCP signaling is connected to some CHDs. Here, we summarize our current understanding of how PCP factors affect the pathogenesis of CHD.

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