scholarly journals Centrosome and ciliary abnormalities in fetal akinesia deformation sequence human fibroblasts

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ramona Jühlen ◽  
Valérie Martinelli ◽  
Chiara Vinci ◽  
Jeroen Breckpot ◽  
Birthe Fahrenkrog

Abstract Ciliopathies are clinical disorders of the primary cilium with widely recognised phenotypic and genetic heterogeneity. Here, we found impaired ciliogenesis in fibroblasts derived from individuals with fetal akinesia deformation sequence (FADS), a broad spectrum of neuromuscular disorders arising from compromised foetal movement. We show that cells derived from FADS individuals have shorter and less primary cilia (PC), in association with alterations in post-translational modifications in α-tubulin. Similarly, siRNA-mediated depletion of two known FADS proteins, the scaffold protein rapsyn and the nucleoporin NUP88, resulted in defective PC formation. Consistent with a role in ciliogenesis, rapsyn and NUP88 localised to centrosomes and PC. Furthermore, proximity-ligation assays confirm the respective vicinity of rapsyn and NUP88 to γ-tubulin. Proximity-ligation assays moreover show that rapsyn and NUP88 are adjacent to each other and that the rapsyn-NUP88 interface is perturbed in the examined FADS cells. We suggest that the perturbed rapsyn-NUP88 interface leads to defects in PC formation and that defective ciliogenesis contributes to the pleiotropic defects seen in FADS.

2019 ◽  
Author(s):  
Ramona Jühlen ◽  
Valérie Martinelli ◽  
Chiara Vinci ◽  
Jeroen Breckpot ◽  
Birthe Fahrenkrog

AbstractCiliopathies are clinical disorders of the primary cilium with widely recognised phenotypic and genetic heterogeneity. Here we found impaired ciliogenesis in fibroblasts derived from individuals with fetal akinesia deformation sequence (FADS), a broad spectrum of neuromuscular disorders arising from impaired foetal movement. We show that cells derived from FADS individuals have shorter and less primary cilia (PC), in association with alterations in post-translational modifications in α-tubulin. Similarly, siRNA-mediated depletion of two known FADS proteins, the scaffold protein rapsyn and the nucleoporin NUP88, resulted in defective PC formation. Consistent with a role in ciliogenesis, rapsyn and NUP88 localised to centrosomes and PC. By proximity-ligation assays, we show that rapsyn and NUP88 are adjacent and that both proteins are adjoining to all three tubulin isoforms (α, and γ rapsyn-NUP88 interface, as well as their contact to microtubules, is perturbed in the examined FADS cells. We suggest that the perturbed rapsyn-NUP88-tubulin interface leads to defects in PC formation and that defective ciliogenesis contributes to the pleiotropic defects seen in FADS.SummaryFibroblasts derived from fetal akinesia individuals are characterised by ciliary defects and rapsyn and NUP88 are required for proper formation of the primary cilium.


2017 ◽  
Vol 97 (1) ◽  
pp. 108-117 ◽  
Author(s):  
P. Cela ◽  
M. Hampl ◽  
N.A. Shylo ◽  
K.J. Christopher ◽  
M. Kavkova ◽  
...  

A broad spectrum of human diseases called ciliopathies is caused by defective primary cilia morphology or signal transduction. The primary cilium is a solitary organelle that responds to mechanical and chemical stimuli from extracellular and intracellular environments. Transmembrane protein 107 (TMEM107) is localized in the primary cilium and is enriched at the transition zone where it acts to regulate protein content of the cilium. Mutations in TMEM107 were previously connected with oral-facial-digital syndrome, Meckel-Gruber syndrome, and Joubert syndrome exhibiting a range of ciliopathic defects. Here, we analyze a role of Tmem107 in craniofacial development with special focus on palate formation, using mouse embryos with a complete knockout of Tmem107. Tmem107–/– mice were affected by a broad spectrum of craniofacial defects, including shorter snout, expansion of the facial midline, cleft lip, extensive exencephaly, and microphthalmia or anophthalmia. External abnormalities were accompanied by defects in skeletal structures, including ossification delay in several membranous bones and enlargement of the nasal septum or defects in vomeronasal cartilage. Alteration in palatal shelves growth resulted in clefting of the secondary palate. Palatal defects were caused by increased mesenchymal proliferation leading to early overgrowth of palatal shelves followed by defects in their horizontalization. Moreover, the expression of epithelial stemness marker SOX2 was altered in the palatal shelves of Tmem107–/– animals, and differences in mesenchymal SOX9 expression demonstrated the enhancement of neural crest migration. Detailed analysis of primary cilia revealed region-specific changes in ciliary morphology accompanied by alteration of acetylated tubulin and IFT88 expression. Moreover, Shh and Gli1 expression was increased in Tmem107–/– animals as shown by in situ hybridization. Thus, TMEM107 is essential for proper head development, and defective TMEM107 function leads to ciliary morphology disruptions in a region-specific manner, which may explain the complex mutant phenotype.


2021 ◽  
Author(s):  
Shuwei Xie ◽  
Ellie Smith ◽  
Carter Dierlam ◽  
Danita Mathew ◽  
Angelina Davis ◽  
...  

The mammalian retromer is comprised of subunits VPS26, VPS29 and VPS35, and a more loosely-associated sorting nexin (SNX) heterodimer. Despite known roles for the retromer in multiple trafficking events in yeast and mammalian cells, its role in development is poorly understood, and its potential function in primary ciliogenesis remains unknown. Using CRISPR-Cas9 editing, we demonstrated that vps-26 homozygous knockout C. elegans have reduced brood sizes and impaired vulval development, as well as decreased body length which has been linked to defects in primary ciliogenesis. Since many endocytic proteins are implicated in the generation of primary cilia, we addressed whether the retromer regulates ciliogenesis in mammalian cells. We observed VPS35 localized to the primary cilium, and depletion of VPS26, VPS35 or SNX1/SNX5 led to decreased ciliogenesis. Retromer also coimmunoprecipitated with the capping protein, CP110, and was required for its removal from the mother centriole. Herein, we characterize new roles for the retromer in C. elegans development and in the regulation of ciliogenesis in mammalian cells, and suggest a novel role for the retromer in CP110 removal from the mother centriole.


Author(s):  
Leticia Labat-de-Hoz ◽  
Armando Rubio-Ramos ◽  
Javier Casares-Arias ◽  
Miguel Bernabé-Rubio ◽  
Isabel Correas ◽  
...  

Primary cilia are solitary, microtubule-based protrusions surrounded by a ciliary membrane equipped with selected receptors that orchestrate important signaling pathways that control cell growth, differentiation, development and homeostasis. Depending on the cell type, primary cilium assembly takes place intracellularly or at the cell surface. The intracellular route has been the focus of research on primary cilium biogenesis, whereas the route that occurs at the cell surface, which we call the “alternative” route, has been much less thoroughly characterized. In this review, based on recent experimental evidence, we present a model of primary ciliogenesis by the alternative route in which the remnant of the midbody generated upon cytokinesis acquires compact membranes, that are involved in compartmentalization of biological membranes. The midbody remnant delivers part of those membranes to the centrosome in order to assemble the ciliary membrane, thereby licensing primary cilium formation. The midbody remnant's involvement in primary cilium formation, the regulation of its inheritance by the ESCRT machinery, and the assembly of the ciliary membrane from the membranes originally associated with the remnant are discussed in the context of the literature concerning the ciliary membrane, the emerging roles of the midbody remnant, the regulation of cytokinesis, and the role of membrane compartmentalization. We also present a model of cilium emergence during evolution, and summarize the directions for future research.


2013 ◽  
Vol 304 (10) ◽  
pp. F1283-F1294 ◽  
Author(s):  
Jee In Kim ◽  
Jinu Kim ◽  
Hee-Seong Jang ◽  
Mi Ra Noh ◽  
Joshua H. Lipschutz ◽  
...  

The primary cilium is a microtubule-based nonmotile organelle that extends from the surface of cells, including renal tubular cells. Here, we investigated the alteration of primary cilium length during epithelial cell injury and repair, following ischemia/reperfusion (I/R) insult, and the role of reactive oxygen species in this alteration. Thirty minutes of bilateral renal ischemia induced severe renal tubular cell damage and an increase of plasma creatinine (PCr) concentration. Between 8 and 16 days following the ischemia, the increased PCr returned to normal range, although without complete histological restoration. Compared with the primary cilium length in normal kidney tubule cells, the length was shortened 4 h and 1 day following ischemia, increased over normal 8 days after ischemia, and then returned to near normal 16 days following ischemia. In the urine of I/R-subjected mice, acetylated tubulin was detected. The cilium length of proliferating cells was shorter than that in nonproliferating cells. Mature cells had shorter cilia than differentiating cells. Treatment with Mn(III) tetrakis(1-methyl-4-pyridyl) porphyrin (MnTMPyP), an antioxidant, during the recovery of damaged kidneys accelerated normalization of cilia length concomitant with a decrease of oxidative stress and morphological recovery in the kidney. In the Madin-Darby canine kidney (MDCK) cells, H2O2 treatment caused released ciliary fragment into medium, and MnTMPyP inhibited the deciliation. The ERK inhibitor U0126 inhibited elongation of cilia in normal and MDCK cells recovering from H2O2 stress. Taken together, our results suggest that primary cilia length reflects cell proliferation and the length of primary cilium is regulated, at least, in part, by reactive oxygen species through ERK.


2018 ◽  
Vol 10 ◽  
pp. 175883591880116 ◽  
Author(s):  
María Álvarez-Satta ◽  
Ander Matheu

Glioblastoma (GBM) represents the most common, malignant and lethal primary brain tumour in adults. The primary cilium is a highly conserved and dynamic organelle that protrudes from the apical surface of virtually every type of mammalian cell. There is increasing evidence that abnormal cilia are involved in cancer progression, since primary cilia regulate cell cycle and signalling transduction. In this review, we summarize the role of primary cilium specifically with regard to GBM, where there is evidence postulating it as a critical mediator of GBM tumorigenesis and progression. This opens the way to the application of cilia-targeted therapies (‘ciliotherapy’) as a new approach in the fight against this devastating tumour.


Author(s):  
R. John Leigh ◽  
David S. Zee

This chapter reviews contributions of orbital tissues and extraocular muscles (EOM) to the control of eye movements. The anatomy of the orbit, fascia, fibromuscular pulleys, and EOM are described and related to the kinematics of 3-D eye rotations. Current concepts of the embryology of the EOM and their unique and diverse characteristics are described, suggesting why they are more vulnerable to certain neuromuscular disorders and less susceptible to others, compared with skeletal muscles. Electrophysiological properties of different EOM fiber types (and their motor neuron innervation) are contrasted, describing new models that attempt to account for nonlinear mechanical properties of the orbit. The substrate and roles of extraocular proprioception in the control of eye movements are summarized and related to clinical disorders affecting EOM. The anatomy of the cranial nerves supplying the EOM is summarized, diagrammed and highlighted to aid diagnosis of common palsies of the oculomotor, trochlear, and abducens nerves.


2009 ◽  
Vol 88 (6) ◽  
pp. 545-550 ◽  
Author(s):  
T. Ochiai ◽  
M. Nagayama ◽  
T. Nakamura ◽  
T. Morrison ◽  
D. Pilchak ◽  
...  

Primary cilia regulate several developmental processes and mediate hedgehog signaling. To study their roles in cranial base development, we created conditional mouse mutants deficient in Polaris, a critical primary cilium component, in cartilage. Mutant post-natal cranial bases were deformed, and their synchondrosis growth plates were disorganized. Expression of Indian hedgehog, Patched-1, collagen X, and MMP-13 was reduced and accompanied by decreases in endochondral bone. Interestingly, there was excessive intramembranous ossification along the perichondrium, accompanied by excessive Patched-1 expression, suggesting that Ihh distribution was wider and responsible for such excessive response. Indeed, expression of heparan sulfate proteoglycans (HS-PGs), normally involved in restricting hedgehog distribution, was barely detectable in mutant synchondroses. Analyses of the data provides further evidence for the essential roles of primary cilia and hedgehog signaling in cranial base development and chondrocyte maturation, and point to a close interdependence between cilia and HS-PGs to delimit targets of hedgehog action in synchondroses.


2019 ◽  
Vol 116 (10) ◽  
pp. 4316-4325 ◽  
Author(s):  
Michaela Kunova Bosakova ◽  
Alexandru Nita ◽  
Tomas Gregor ◽  
Miroslav Varecha ◽  
Iva Gudernova ◽  
...  

Vertebrate primary cilium is a Hedgehog signaling center but the extent of its involvement in other signaling systems is less well understood. This report delineates a mechanism by which fibroblast growth factor (FGF) controls primary cilia. Employing proteomic approaches to characterize proteins associated with the FGF-receptor, FGFR3, we identified the serine/threonine kinase intestinal cell kinase (ICK) as an FGFR interactor. ICK is involved in ciliogenesis and participates in control of ciliary length. FGF signaling partially abolished ICK’s kinase activity, through FGFR-mediated ICK phosphorylation at conserved residue Tyr15, which interfered with optimal ATP binding. Activation of the FGF signaling pathway affected both primary cilia length and function in a manner consistent with cilia effects caused by inhibition of ICK activity. Moreover, knockdown and knockout of ICK rescued the FGF-mediated effect on cilia. We provide conclusive evidence that FGF signaling controls cilia via interaction with ICK.


Author(s):  
Koji Ikegami ◽  
Faryal Ijaz

Abstract Mammalian cells have a tiny hair-like protrusion on their surface called a primary cilium. Primary cilia are thought to be the antennae for the cells, receiving signals from the environment. In some studies, extracellular vesicles (EVs) were found attached to the surface of the primary cilium. An idea for the phenomenon is that the primary cilium is the receptor for receiving the EVs. Meanwhile, a unicellular organism, Chlamydomonas, which has two long cilia, usually called flagella, release EVs termed ectosomes from the surface of the flagella. Accumulating evidence suggests that the primary cilium also functions as the ‘emitter’ of EVs. Physiological and pathological impacts are also elucidated for the release of EVs from primary cilia. However, the roles of released cilia-derived EVs remain to be clarified. This review introduces the historical background of the relationship between EVs and cilia, and recent progresses in the research field.


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