scholarly journals Properties of Non-Aminoglycoside Compounds Used to Stimulate Translational Readthrough of PTC Mutations in Primary Ciliary Dyskinesia

2021 ◽  
Vol 22 (9) ◽  
pp. 4923
Author(s):  
Maciej Dabrowski ◽  
Zuzanna Bukowy-Bieryllo ◽  
Claire L. Jackson ◽  
Ewa Zietkiewicz
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Negative Impact ◽  
Beat Frequency ◽  
Autosomal Recessive Inheritance ◽  
Hek293 Cells ◽  
Functional Protein ◽  
Lower Efficiency ◽  
Translational Readthrough ◽  
And Function ◽  
Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a rare disease with autosomal recessive inheritance, caused mostly by bi-allelic gene mutations that impair motile cilia structure and function. Currently, there are no causal treatments for PCD. In many disease models, translational readthrough of premature termination codons (PTC-readthrough) induced by aminoglycosides has been proposed as an effective way of restoring functional protein expression and reducing disease symptoms. However, variable outcomes of pre-clinical trials and toxicity associated with long-term use of aminoglycosides prompt the search for other compounds that might overcome these problems. Because a high proportion of PCD-causing variants are nonsense mutations, readthrough therapies are an attractive option. We tested a group of chemical compounds with known PTC-readthrough potential (ataluren, azithromycin, tylosin, amlexanox, and the experimental compound TC007), collectively referred to as non-aminoglycosides (NAGs). We investigated their PTC-readthrough efficiency in six PTC mutations found in Polish PCD patients, in the context of cell and cilia health, and in comparison to the previously tested aminoglycosides. The NAGs did not compromise the viability of the primary nasal respiratory epithelial cells, and the ciliary beat frequency was retained, similar to what was observed for gentamicin. In HEK293 cells transfected with six PTC-containing inserts, the tested compounds stimulated PTC-readthrough but with lower efficiency than aminoglycosides. The study allowed us to select compounds with minimal negative impact on cell viability and function but still the potential to induce PTC-readthrough.

scholarly journals Higher throughput drug screening for rare respiratory diseases: Readthrough therapy in primary ciliary dyskinesia

2021 ◽  
pp. 2000455
Author(s):  
Dani Do Hyang Lee ◽  
Daniela Cardinale ◽  
Ersilia Nigro ◽  
Colin R. Butler ◽  
Andrew Rutman ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
High Throughput Screening ◽  
Primary Ciliary Dyskinesia ◽  
Respiratory Diseases ◽  
Beat Frequency ◽  
Screening Method ◽  
Respiratory Epithelium ◽  
Basal Cells ◽  
Translational Readthrough ◽  
Ciliary Dyskinesia

Development of therapeutic approaches for rare respiratory diseases is hampered by the lack of systems that allow medium-to-high-throughput screening of fully differentiated respiratory epithelium from affected patients. This is a particular problem for primary ciliary dyskinesia (PCD), a rare genetic disease caused by mutations in genes that adversely affect ciliary movement and consequently mucociliary transport. Primary cell culture of basal epithelial cells from nasal brush biopsies, followed by ciliated differentiation at air-liquid interface (ALI) has proven to be a useful tool in PCD diagnostics but the technique's broader utility, including in pre-clinical PCD research, has been restricted by the limited number of basal cells that it is possible to expand from such biopsies. Here, we describe an immunofluorescence screening method, enabled by extensive expansion of PCD patient basal cells and their culture into differentiated respiratory epithelium in miniaturised 96-well transwell format ALI cultures. Analyses of ciliary ultrastructure, beat pattern and beat frequency indicate that a range of different PCD defects can be retained in these cultures. As proof-of-principle, we performed a personalised investigation in a patient with a rare and severe form of PCD (reduced generation of motile cilia, RGMC), in this case caused by a homozygous nonsense mutation in the MCIDAS gene. The screening system allowed drugs that induce translational readthrough to be evaluated alone or in combination with nonsense-mediated decay inhibitors. Restoration of basal body formation in the patient's nasal epithelial cells was seen in vitro, suggesting a novel avenue for drug evaluation and development in PCD.

scholarly journals Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia

2019 ◽  
Vol 57 (4) ◽  
pp. 237-244 ◽  
Author(s):  
Sylvain Blanchon ◽  
Marie Legendre ◽  
Mathieu Bottier ◽  
Aline Tamalet ◽  
Guy Montantin ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
High Speed ◽  
Genetic Disorder ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Central Complex ◽  
Ciliary Beating ◽  
Recovery Stroke ◽  
Biallelic Mutations ◽  
Ciliary Dyskinesia

BackgroundPrimary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.MethodsWe prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).ResultsSixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.ConclusionQuantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

scholarly journals Pcdp1 is a central apparatus protein that binds Ca2+-calmodulin and regulates ciliary motility

2010 ◽  
Vol 189 (3) ◽  
pp. 601-612 ◽  
Author(s):  
Christen G. DiPetrillo ◽  
Elizabeth F. Smith
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Calcium Concentration ◽  
Beat Frequency ◽  
Calcium Sensor ◽  
Central Pair ◽  
Ciliary Motility ◽  
Significant Impairment ◽  
Central Apparatus ◽  
Cilia And Flagella ◽  
Ciliary Dyskinesia

For all motile eukaryotic cilia and flagella, beating is regulated by changes in intraciliary calcium concentration. Although the mechanism for calcium regulation is not understood, numerous studies have shown that calmodulin (CaM) is a key axonemal calcium sensor. Using anti-CaM antibodies and Chlamydomonas reinhardtii axonemal extracts, we precipitated a complex that includes four polypeptides and that specifically interacts with CaM in high [Ca2+]. One of the complex members, FAP221, is an orthologue of mammalian Pcdp1 (primary ciliary dyskinesia protein 1). Both FAP221 and mammalian Pcdp1 specifically bind CaM in high [Ca2+]. Reduced expression of Pcdp1 complex members in C. reinhardtii results in failure of the C1d central pair projection to assemble and significant impairment of motility including uncoordinated bends, severely reduced beat frequency, and altered waveforms. These combined results reveal that the central pair Pcdp1 (FAP221) complex is essential for control of ciliary motility.

Incidence of Primary Ciliary Dyskinesia in Children with Recurrent Respiratory Diseases

1997 ◽  
Vol 106 (10) ◽  
pp. 854-858 ◽  
Author(s):  
André Coste ◽  
Marie-Claude Millepied ◽  
Catherine Chapelin ◽  
Philippe Reinert ◽  
Françoise Poron ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Respiratory Tract Infections ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Systematic Investigation ◽  
Ciliated Cells ◽  
Tract Infections ◽  
Ciliary Dyskinesia ◽  
Ciliary Ultrastructure ◽  
Recurrent Respiratory Tract Infections

The goal of the study was to evaluate the incidence of primary ciliary dyskinesia (PCD) in children suffering from recurrent respiratory tract infections (RRIs) by means of a noninvasive method. Respiratory ciliated cells were collected by nasal brushing in 118 children (4.6 ± 2.5 years) with RRIs. The ciliary beat frequency (CBF) was measured with a stroboscopic method, and when the CBF was abnormal, the ciliary ultrastructure was analyzed by a quantitative method. The CBF could be measured in 106 patients (90%) and was abnormal in 15 patients. The ciliary ultrastructure was found to be abnormal in 11 of 15 patients: PCD was diagnosed in 6 cases, and acquired ciliary defects were observed in the remaining 5 patients. Our conclusion, that PCD is rare but not exceptional (5.6%) in children with RRIs, justifies the systematic investigation of ciliated cells in such patients. For this purpose, nasal brushing can be used to sample ciliated cells even in young children.

Reduced Von Willebrand Factor Secretion Is Associated with Loss of Weibel-Palade Formation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 541-541
Author(s):  
Giancarlo Castaman ◽  
Sofia Helene Giacomelli ◽  
Paula M. Jacobi ◽  
Tobias Obser ◽  
Reinhard Schneppenheim ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Conflicts Of Interest ◽  
Negative Impact ◽  
Von Willebrand Disease ◽  
Hek293 Cells ◽  
Wild Type ◽  
And Function ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 541 Background. Von Willebrand Disease (VWD) is caused by mutations in von Willebrand factor (VWF) that have different pathophysiologic effect in causing low plasma VWF levels. Type 1 VWD includes patients with quantitative plasma VWF deficiency with normal VWF structure and function. Aim of the study. We report three different novel type 1 VWF mutations (A1716P, C2190Y and R2663C) which although located in different VWF domains are associated with reduced secretion and lack of formation of Weibel-Palade body-like granules. Methods. Transient expression of recombinant mutant full-length VWF in 293 EBNA cells was performed and secretion, collagen binding, and GpIb binding assessed in comparison to wild-type VWF. Furthermore, expression was also examined in HEK293 cells that form Weibel-Palade body (WPB)-like granules when transfected with wt VWF. Results. The multimer analysis of plasma VWF was compatible with type 1 VWD. The results of 3 different expression experiments showed a slightly reduced VWF synthesis and drastically impaired secretion into the medium with homozygous expression. In HEK293 cells, homozygous A1716P and C2190Y VWF variants failed to form WPB-like granules, while R2663C was capable of forming granules, but had fewer cells with granules and more with ER-localized VWF. Heterozygous expression of A1716P and C2160Y VWF variants had a negative impact on wild-type VWF and WPB-like granules were observed in transfected cells. Conclusions. Our results demonstrate that homozygous and heterozygous quantitative VWF deficiency caused by missense VWF mutations can be associated with inability to form endothelial Weibel-Palade-like granules and mutations in different VWF domains can affect the formation of these organelles. Disclosures: No relevant conflicts of interest to declare.

scholarly journals CiliarMove: new software for evaluating ciliary beat frequency helps find novel mutations by a Portuguese multidisciplinary team on primary ciliary dyskinesia

2021 ◽  
Vol 7 (1) ◽  
pp. 00792-2020
Author(s):  
Pedro Sampaio ◽  
Mónica Ferro da Silva ◽  
Inês Vale ◽  
Mónica Roxo-Rosa ◽  
Andreia Pinto ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Open Source ◽  
Primary Ciliary Dyskinesia ◽  
High Speed ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Control Group ◽  
Observation Method ◽  
Ciliary Dyskinesia ◽  
Ciliary Beat

Evaluation of ciliary beat frequency (CBF) performed by high-speed videomicroscopy analysis (HVMA) is one of the techniques required for the correct diagnosis of primary ciliary dyskinesia (PCD). Currently, due to lack of open-source software, this technique is widely performed by visually counting the ciliary beatings per a given time-window. Our aim was to generate open-source, fast and intuitive software for evaluating CBF, validated in Portuguese PCD patients and healthy volunteers.Nasal brushings collected from 17 adult healthy volunteers and 34 PCD-referred subjects were recorded using HVMA. Evaluation of CBF was compared by two different methodologies: the new semi-automated computer software CiliarMove and the manual observation method using slow-motion movies. Clinical history, nasal nitric oxide and transmission electron microscopy were performed for diagnosis of PCD in the patient group. Genetic analysis was performed in a subset (n=8) of suspected PCD patients.The correlation coefficient between the two methods was R2=0.9895. The interval of CBF values obtained from the healthy control group (n=17) was 6.18–9.17 Hz at 25°C. In the PCD-excluded group (n=16), CBF ranged from 6.84 to 10.93 Hz and in the PCD group (n=18), CBF ranged from 0 to 14.30 Hz.We offer an automated open-source programme named CiliarMove, validated by the manual observation method in a healthy volunteer control group, a PCD-excluded group and a PCD-confirmed group. In our hands, comparisons between CBF intervals alone could discern between healthy and PCD groups in 78% of the cases.

scholarly journals Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images

2011 ◽  
Vol 111 (1) ◽  
pp. 295-302 ◽  
Author(s):  
Mary A. K. Olm ◽  
João E. Kögler ◽  
Mariangela Macchione ◽  
Amelia Shoemark ◽  
Paulo H. N. Saldiva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Primary Ciliary Dyskinesia ◽  
Pulmonary Function Tests ◽  
Beat Frequency ◽  
Power Spectra ◽  
Ciliary Beat Frequency ◽  
Diagnostic Techniques ◽  
Control Group ◽  
Wall Thickening ◽  
Ciliary Dyskinesia

Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ciliary dyskinesia (PCD). We developed a system for measuring CBF, used it in association with electron microscopy to diagnose PCD, and then analyzed characteristics of PCD patients. 1 The CBF measurement system was based on power spectra measured through digital imaging. Twenty-four patients suspected of having PCD (age 1–19 yr) were selected from a group of 75 children and adolescents with pneumopathies of unknown causes. Ten healthy, nonsmoking volunteers (age ≥17 yr) served as a control group. Nasal brush samples were collected, and CBF and electron microscopy were performed. PCD was diagnosed in 12 patients: 5 had radial spoke defects, 3 showed absent central microtubule pairs with transposition, 2 had outer dynein arm defects, 1 had a shortened outer dynein arm, and 1 had a normal ultrastructure. Previous studies have reported that the most common cilia defects are in the dynein arm. As expected, the mean CBF was higher in the control group ( P < 0.001) and patients with normal ultrastructure ( P < 0.002), than in those diagnosed with cilia ultrastructural defects (i.e., PCD patients). An obstructive ventilatory pattern was observed in 70% of the PCD patients who underwent pulmonary function tests. All PCD patients presented bronchial wall thickening on chest computed tomography scans. The protocol and diagnostic techniques employed allowed us to diagnose PCD in 16% of patients in this study.

Primary ciliary dyskinesia and mild cystic fibrosis: lung structure and function similarities

2017 ◽  
Author(s):  
Virginia Mirra ◽  
Marco Maglione ◽  
Silvia Montella ◽  
Francesca Santamaria ◽  
Carmine Mollica ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Primary Ciliary Dyskinesia ◽  
Structure And Function ◽  
Cystic Fibrosis Lung ◽  
Lung Structure ◽  
And Function ◽  
Ciliary Dyskinesia

scholarly journals Bacterial infections in patients with primary ciliary dyskinesia: Comparison with cystic fibrosis

2017 ◽  
Vol 14 (4) ◽  
pp. 392-406 ◽  
Author(s):  
Christiaan DM Wijers ◽  
James F Chmiel ◽  
Benjamin M Gaston
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Primary Ciliary Dyskinesia ◽  
Bacterial Infections ◽  
Respiratory Tract Infections ◽  
Treatment Strategies ◽  
Autosomal Recessive Disorder ◽  
Tract Infections ◽  
And Function ◽  
Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder associated with severely impaired mucociliary clearance caused by defects in ciliary structure and function. Although recurrent bacterial infection of the respiratory tract is one of the major clinical features of this disease, PCD airway microbiology is understudied. Despite the differences in pathophysiology, assumptions about respiratory tract infections in patients with PCD are often extrapolated from cystic fibrosis (CF) airway microbiology. This review aims to summarize the current understanding of bacterial infections in patients with PCD, including infections with Pseudomonas aeruginosa, Staphylococcus aureus, and Moraxella catarrhalis, as it relates to bacterial infections in patients with CF. Further, we will discuss current and potential future treatment strategies aimed at improving the care of patients with PCD suffering from recurring bacterial infections.

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