Biallelic Mutations in LRRC56, Encoding a Protein Associated with Intraflagellar Transport, Cause Mucociliary Clearance and Laterality Defects.

Primary defects in motile cilia result in dysfunction of the apparatus responsible for generating fluid flows. Defects in these mechanisms underlie disorders characterized by poor mucus clearance, resulting in susceptibility to chronic recurrent respiratory infections, often associated with infertility; laterality defects occur in about 50% of such individuals. Here we report biallelic variants in LRRC56 (known as oda8 in Chlamydomonas) identified in three unrelated families. The phenotype comprises laterality defects and chronic pulmonary infections. High-speed video microscopy of cultured epithelial cells from an affected individual showed severely dyskinetic cilia but no obvious ultra-structural abnormalities on routine transmission electron microscopy (TEM). Further investigation revealed that LRRC56 interacts with the intraflagellar transport (IFT) protein IFT88. The link with IFT was interrogated in Trypanosoma brucei. In this protist, LRRC56 is recruited to the cilium during axoneme construction, where it co-localizes with IFT trains and is required for the addition of dynein arms to the distal end of the flagellum. In T. brucei carrying LRRC56-null mutations, or a variant resulting in the p.Leu259Pro substitution corresponding to the p.Leu140Pro variant seen in one of the affected families, we observed abnormal ciliary beat patterns and an absence of outer dynein arms restricted to the distal portion of the axoneme. Together, our findings confirm that deleterious variants in LRRC56 result in a human disease and suggest that this protein has a likely role in dynein transport during cilia assembly that is evolutionarily important for cilia motility.

Mutations in Outer Dynein Arm Heavy Chain DNAH9 Cause Motile Cilia Defects and Situs Inversus.

Motile cilia move body fluids and gametes and the beating of cilia lining the airway epithelial surfaces ensures that they are kept clear and protected from inhaled pathogens and consequent respiratory infections. Dynein motor proteins provide mechanical force for cilia beating. Dynein mutations are a common cause of primary ciliary dyskinesia (PCD), an inherited condition characterized by deficient mucociliary clearance and chronic respiratory disease coupled with laterality disturbances and subfertility. Using next-generation sequencing, we detected mutations in the ciliary outer dynein arm (ODA) heavy chain gene DNAH9 in individuals from PCD clinics with situs inversus and in one case male infertility. DNAH9 and its partner heavy chain DNAH5 localize to type 2 ODAs of the distal cilium and in DNAH9-mutated nasal respiratory epithelial cilia we found a loss of DNAH9/DNAH5-containing type 2 ODAs that was restricted to the distal cilia region. This confers a reduced beating frequency with a subtle beating pattern defect affecting the motility of the distal cilia portion. 3D electron tomography ultrastructural studies confirmed regional loss of ODAs from the distal cilium, manifesting as either loss of whole ODA or partial loss of ODA volume. Paramecium DNAH9 knockdown confirms an evolutionarily conserved function for DNAH9 in cilia motility and ODA stability. We find that DNAH9 is widely expressed in the airways, despite DNAH9 mutations appearing to confer symptoms restricted to the upper respiratory tract. In summary, DNAH9 mutations reduce cilia function but some respiratory mucociliary clearance potential may be retained, widening the PCD disease spectrum.

Ciliated conical epithelial cell protrusions point towards a diagnosis of primary ciliary dyskinesia.

BACKGROUND: Primary ciliary dyskinesia can result from a number of different ciliary defects that adversely affect ciliary function resulting markedly reduced or absent mucociliary clearance. Improvement in diagnostic testing is an area of current research. During diagnostic evaluation of PCD we observed ciliated conical protrusions from part of the apical surface of ciliated cells in those diagnosed with PCD. The aim of this study was to investigate if this abnormality was specific to PCD. METHODS: Epithelial edges from 67 consecutively diagnosed PCD patients, 67 patients consecutively referred for PCD diagnostic testing in whom PCD was excluded, 22 with asthma and 18 with Cystic Fibrosis (CF) were studied retrospectively in a blinded manner using light microscopy. RESULTS: Forty six out of 67 patients with PCD had ciliated conical epithelial protrusions, whereas none were seen in patients where PCD was excluded, or in patients with asthma or CF. The sensitivity, specificity, positive predictive value and negative predictive value for the presence of the ciliated conical protrusions to predict a diagnosis of PCD were 76.5, 100, 100 and 77% respectively. CONCLUSIONS: Characteristic ciliated conical protrusions from ciliated epithelial cells maybe a useful pointer to the diagnosis of PCD. However, their absence does not exclude the diagnosis of PCD.

BMI-1 extends proliferative potential of human bronchial epithelial cells while retaining their mucociliary differentiation capacity.

Air-liquid interface (ALI) culture of primary airway epithelial cells enables mucociliary differentiation providing an in vitro model of the human airway, but their proliferative potential is limited. To extend proliferation, these cells were previously transduced with viral oncogenes or mouse Bmi-1 + hTERT, but the resultant cell lines did not undergo mucociliary differentiation. We hypothesized that use of human BMI-1 alone would increase the proliferative potential of bronchial epithelial cells while retaining their mucociliary differentiation potential. Cystic fibrosis (CF) and non-CF bronchial epithelial cells were transduced by lentivirus with BMI-1 and then their morphology, replication kinetics, and karyotype were assessed. When differentiated at ALI, mucin production, ciliary function, and transepithelial electrophysiology were measured. Finally, shRNA knockdown of DNAH5 in BMI-1 cells was used to model primary ciliary dyskinesia (PCD). BMI-1-transduced basal cells showed normal cell morphology, karyotype, and doubling times despite extensive passaging. The cell lines underwent mucociliary differentiation when cultured at ALI with abundant ciliation and production of the gel-forming mucins MUC5AC and MUC5B evident. Cilia displayed a normal beat frequency and 9+2 ultrastructure. Electrophysiological characteristics of BMI-1-transduced cells were similar to those of untransduced cells. shRNA knockdown of DNAH5 in BMI-1 cells produced immotile cilia and absence of DNAH5 in the ciliary axoneme as seen in cells from patients with PCD. BMI-1 delayed senescence in bronchial epithelial cells, increasing their proliferative potential but maintaining mucociliary differentiation at ALI. We have shown these cells are amenable to genetic manipulation and can be used to produce novel disease models for research and dissemination.

Hypoxia upregulates neutrophil degranulation and potential for tissue injury.

BACKGROUND: The inflamed bronchial mucosal surface is a profoundly hypoxic environment. Neutrophilic airway inflammation and neutrophil-derived proteases have been linked to disease progression in conditions such as COPD and cystic fibrosis, but the effects of hypoxia on potentially harmful neutrophil functional responses such as degranulation are unknown. METHODS AND RESULTS: Following exposure to hypoxia (0.8% oxygen, 3 kPa for 4 h), neutrophils stimulated with inflammatory agonists (granulocyte-macrophage colony stimulating factor or platelet-activating factor and formylated peptide) displayed a markedly augmented (twofold to sixfold) release of azurophilic (neutrophil elastase, myeloperoxidase), specific (lactoferrin) and gelatinase (matrix metalloproteinase-9) granule contents. Neutrophil supernatants derived under hypoxic but not normoxic conditions induced extensive airway epithelial cell detachment and death, which was prevented by coincubation with the antiprotease α-1 antitrypsin; both normoxic and hypoxic supernatants impaired ciliary function. Surprisingly, the hypoxic upregulation of neutrophil degranulation was not dependent on hypoxia-inducible factor (HIF), nor was it fully reversed by inhibition of phospholipase C signalling. Hypoxia augmented the resting and cytokine-stimulated phosphorylation of AKT, and inhibition of phosphoinositide 3-kinase (PI3K)γ (but not other PI3K isoforms) prevented the hypoxic upregulation of neutrophil elastase release. CONCLUSION: Hypoxia augments neutrophil degranulation and confers enhanced potential for damage to respiratory airway epithelial cells in a HIF-independent but PI3Kγ-dependent fashion.

NADPH Oxidase-4 Overexpression Is Associated With Epithelial Ciliary Dysfunction in Neutrophilic Asthma.

BACKGROUND: Bronchial epithelial ciliary dysfunction is an important feature of asthma. We sought to determine the role in asthma of neutrophilic inflammation and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases in ciliary dysfunction. METHODS: Bronchial epithelial ciliary function was assessed by using video microscopy in fresh ex vivo epithelial strips from patients with asthma stratified according to their sputum cell differentials and in culture specimens from healthy control subjects and patients with asthma. Bronchial epithelial oxidative damage was determined by 8-oxo-dG expression. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)/dual oxidase (DUOX) expression was assessed in bronchial epithelial cells by using microarrays, with NOX4 and DUOX1/2 expression assessed in bronchial biopsy specimens. Ciliary dysfunction following NADPH oxidase inhibition, using GKT137831, was evaluated in fresh epithelial strips from patients with asthma and a murine model of ovalbumin sensitization and challenge. RESULTS: Ciliary beat frequency was impaired in patients with asthma with sputum neutrophilia (n = 11) vs those without (n = 10) (5.8 [0.6] Hz vs 8.8 [0.5] Hz; P = .003) and was correlated with sputum neutrophil count (r = -0.70; P < .001). Primary bronchial epithelial cells expressed DUOX1/2 and NOX4. Levels of 8-oxo-dG and NOX4 were elevated in patients with neutrophilic vs nonneutrophilic asthma, DUOX1 was elevated in both, and DUOX2 was elevated in nonneutrophilic asthma in vivo. In primary epithelial cultures, ciliary dysfunction did not persist, although NOX4 expression and reactive oxygen species generation was increased from patients with neutrophilic asthma. GKT137831 both improved ciliary function in ex vivo epithelial strips (n = 13), relative to the intensity of neutrophilic inflammation, and abolished ciliary dysfunction in the murine asthma model with no reduction in inflammation. CONCLUSIONS: Ciliary dysfunction is increased in neutrophilic asthma associated with increased NOX4 expression and is attenuated by NADPH oxidase inhibition.

Respiratory syncytial virus increases the virulence of Streptococcus pneumoniae by binding to penicillin binding protein 1a. A new paradigm in respiratory infection.

RATIONALE: Respiratory syncytial virus (RSV) and Streptococcus pneumoniae are major respiratory pathogens. Coinfection with RSV and S. pneumoniae is associated with severe and often fatal pneumonia but the molecular basis for this remains unclear. OBJECTIVES: To determine if interaction between RSV and pneumococci enhances pneumococcal virulence. METHODS: We used confocal microscopy and Western blot to identify the receptors involved in direct binding of RSV and pneumococci, the effects of which were studied in both in vivo and in vitro models of infection. Human ciliated respiratory epithelial cell cultures were infected with RSV for 72 hours and then challenged with pneumococci. Pneumococci were collected after 2 hours exposure and changes in gene expression determined using quantitative real-time polymerase chain reaction. MEASUREMENTS AND MAIN RESULTS: Following incubation with RSV or purified G protein, pneumococci demonstrated a significant increase in the inflammatory response and bacterial adherence to human ciliated epithelial cultures and markedly increased virulence in a pneumonia model in mice. This was associated with extensive changes in the pneumococcal transcriptome and significant up-regulation in the expression of key pneumococcal virulence genes, including the gene for the pneumococcal toxin, pneumolysin. We show that mechanistically this is caused by RSV G glycoprotein binding penicillin binding protein 1a. CONCLUSIONS: The direct interaction between a respiratory virus protein and the pneumococcus resulting in increased bacterial virulence and worsening disease outcome is a new paradigm in respiratory infection.

Culture of primary ciliary dyskinesia epithelial cells at air-liquid interface can alter ciliary phenotype but remains a robust and informative diagnostic aid.

BACKGROUND: The diagnosis of primary ciliary dyskinesia (PCD) requires the analysis of ciliary function and ultrastructure. Diagnosis can be complicated by secondary effects on cilia such as damage during sampling, local inflammation or recent infection. To differentiate primary from secondary abnormalities, re-analysis of cilia following culture and re-differentiation of epithelial cells at an air-liquid interface (ALI) aids the diagnosis of PCD. However changes in ciliary beat pattern of cilia following epithelial cell culture has previously been described, which has brought the robustness of this method into question. This is the first systematic study to evaluate ALI culture as an aid to diagnosis of PCD in the light of these concerns. METHODS: We retrospectively studied changes associated with ALI-culture in 158 subjects referred for diagnostic testing at two PCD centres. Ciliated nasal epithelium (PCD n = 54; non-PCD n  111) was analysed by high-speed digital video microscopy and transmission electron microscopy before and after culture. RESULTS: Ciliary function was abnormal before and after culture in all subjects with PCD; 21 PCD subjects had a combination of static and uncoordinated twitching cilia, which became completely static following culture, a further 9 demonstrated a decreased ciliary beat frequency after culture. In subjects without PCD, secondary ciliary dyskinesia was reduced. CONCLUSIONS: The change to ciliary phenotype in PCD samples following cell culture does not affect the diagnosis, and in certain cases can assist the ability to identify PCD cilia.

RHPS4 G-quadruplex ligand induces anti-proliferative effects in brain tumor cells.

BACKGROUND: Telomeric 3' overhangs can fold into a four-stranded DNA structure termed G-quadruplex (G4), a formation which inhibits telomerase. As telomerase activation is crucial for telomere maintenance in most cancer cells, several classes of G4 ligands have been designed to directly disrupt telomeric structure. METHODS: We exposed brain tumor cells to the G4 ligand 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate (RHPS4) and investigated proliferation, cell cycle dynamics, telomere length, telomerase activity and activated c-Myc levels. RESULTS: Although all cell lines tested were sensitive to RHPS4, PFSK-1 central nervous system primitive neuroectodermal cells, DAOY medulloblastoma cells and U87 glioblastoma cells exhibited up to 30-fold increased sensitivity compared to KNS42 glioblastoma, C6 glioma and Res196 ependymoma cells. An increased proportion of S-phase cells were observed in medulloblastoma and high grade glioma cells whilst CNS PNET cells showed an increased proportion of G1-phase cells. RHPS4-induced phenotypes were concomitant with telomerase inhibition, manifested in a telomere length-independent manner and not associated with activated c-Myc levels. However, anti-proliferative effects were also observed in normal neural/endothelial cells in vitro and ex vivo. CONCLUSION: This study warrants in vivo validation of RHPS4 and alternative G4 ligands as potential anti-cancer agents for brain tumors but highlights the consideration of dose-limiting tissue toxicities.

Ciliary dyskinesia is an early feature of respiratory syncytial virus infection.

Respiratory syncytial virus is a major cause of respiratory disease. There are conflicting accounts of the response of human epithelial cells to respiratory syncytial virus and a lack of data on its effect on ciliary function. Our aim was to study the early stages of respiratory syncytial virus infection of primary human basal and ciliated cultures. Using high speed videomicroscopy, we found that ciliary beat frequency was unaffected by respiratory syncytial virus infection over 72 h; however, ciliary dyskinesia significantly increased within 24 h of infection (p<0.05). Transmission electron microscopy revealed that ultrastructural abnormalities were confined to ciliated cells, including increased cilia loss and mitochondrial damage. Confocal immunofluorescence microscopy showed that respiratory syncytial virus antigen gradually spread from the cell surface to the ciliary tip of infected cells over 3 days. Interestingly, ciliated cultures secreted fewer viruses than basal (progenitor) cell cultures and produced a chemokine response focused on recruitment of neutrophils. This study highlights differences in infection models and underscores the need to explore further the role of ciliated cells in the establishment of respiratory syncytial virus infection. Increased ciliary dyskinesia combined with ciliary loss and epithelial damage is likely to result in reduced mucociliary clearance early in the infective process.

Ciliated cultures from patients with primary ciliary dyskinesia do not produce nitric oxide or inducible nitric oxide synthase during early infection.

BACKGROUND: The mechanism behind why patients with primary ciliary dyskinesia (PCD) exhibit low nasal and exhaled nitric oxide (NO) remains unknown. One hypothesis is that reduced NO biosynthesis is caused by a defect in one or more NO synthases (NOSs). In healthy cells, the biosynthesis of NO is increased following exposure to respiratory pathogens. Here, we aimed to investigate whether ciliated epithelial cells from patients with PCD increase NO production following pneumococcal infection. METHODS: Human respiratory epithelium was cultured to a basal or ciliated cell phenotype using submerged or air-liquid interface cultures, respectively. Cells were exposed to media or pneumococci until cells became damaged (< 4 h). Apical fluids were collected prior and following infection, and NO production was determined using chemiluminescence. NOS gene expression was determined using real-time quantitative polymerase chain reaction. RESULTS: Levels of NO and NOS2 gene expression increased significantly following infection of healthy ciliated epithelial cells but not basal cells. No increase in NO was seen in ciliated cell cultures from patients with PCD, and NOS2 gene expression remained unchanged from baseline. CONCLUSIONS: These results suggest that the biosynthesis of NO in ciliated cells from patients with PCD is abnormal following early bacterial challenge, suggesting an abnormality in the function of inducible NOS in PCD.

Elevated anandamide and related N-acylethanolamine levels occur in the peripheral blood of women with ectopic pregnancy and are mirrored by changes in peripheral fatty acid amide hydrolase activity.

BACKGROUND: Studies from knockout mice suggest that perturbations in oviductal endocannabinoid levels, endocannabinoid receptors, or endocannabinoid degrading enzyme [fatty acid amide hydrolase (FAAH)] expression result in infertility secondary to physical trapping of embryos. Similar observations have been made in ectopic pregnant women together with a suggestion that the endocannabinoid receptor gene polymorphism 1359G/A (rs1049353) is associated with ectopic pregnancy. These observations led to the hypothesis that ectopic pregnancy is associated with a perturbation in levels of endocannabinoids and FAAH activity and that such changes are associated with impaired tubal function. AIMS: The objective of the study was to quantify the plasma levels of endocannabinoids (anandamide, oleoylethanolamide, and palmitoylethanolamide) and evaluate blood endocannabinoid metabolizing enzyme activities FAAH and N-acyl-phosphatidyl-ethanolamine phospholipase D (NAPE-PLD) in ectopic pregnancy and normal pregnant controls and relate that to ß-human chorionic gonadotropin (ß-hCG) levels. Additionally, we wanted to examine the effect of endocannabinoids on cilia beat frequency in Fallopian tube epithelial cells ex vivo. PARTICIPANTS AND METHODS: Whole blood collected from ectopic and normal pregnancies was used for quantification of plasma endocannabinoid levels by ultra-HPLC-tandem mass spectrometry of FAAH and NAPE-PLD enzyme activities by radiometric assays, and ß-hCG by immunoassay. Fallopian tube epithelial cells from healthy volunteers were treated with endocannabinoids and cilia beat frequency analyzed using a high-speed digital camera and CiliaFA software. RESULTS: FAAH activity (P < .05) but not NAPE-PLD activity was significantly reduced in ectopic pregnancies. All 3 endocannabinoids levels were significantly higher (P < .05) in ectopic pregnancy. There was no correlation between endocannabinoids, enzyme activity, and ß-hCG levels. Oleoylethanolamide (P < .05), but not methanandamide or palmitoylethanolamide, significantly decreased cilia beat frequency in Fallopian tube epithelial cells. CONCLUSION: Elevated endocannabinoid levels and reduced FAAH activity are associated with ectopic pregnancy and may modulate tubal function, suggesting dysfunctional endocannabinoid action in ectopic implantation. Oleoylethanolamide may play a critical role in embryo-tubal transport.

Persistent disruption of ciliated epithelium following paediatric lung transplantation.

It is unclear whether ciliary function following lung transplantation is normal or not. Our aim was to study the ciliary function and ultrastructure of epithelium above and below the airway anastomosis and the peripheral airway of children following lung transplantation. We studied the ciliary beat frequency (CBF) and beat pattern, using high speed digital video imaging and ultrastructure by transmission electron microscopy, of bronchial epithelium from above and below the airway anastomosis and the peripheral airway of 10 cystic fibrosis (CF) and 10 non-suppurative lung disease (NSLD) paediatric lung transplant recipients. Compared to epithelium below the anastomosis, the epithelium above the anastomosis in the CF group showed reduced CBF (median (interquartile range): 10.5 (9.0-11.4) Hz versus 7.4 (6.4-9.2) Hz; p<0.01) and increased dyskinesia (median (IQR): 16.5 (12.9-28.2)% versus 42.2 (32.6-56.4)%; p<0.01). In both CF and NSLD groups, compared with epithelium above the anastomosis, the epithelium below the anastomosis showed marked ultrastructural abnormalities (median duration post-transplant 7-12 months). Ciliary dysfunction is a feature of native airway epithelium in paediatric CF lung transplant recipients. The epithelium below the airway anastomosis shows profound ultrastructural abnormalities in both CF and NSLD lung transplant recipients, many months after transplantation.

Cooling of cilia allows functional analysis of the beat pattern for diagnostic testing.

BACKGROUND: Reports of the effect of low temperatures on ciliary beat frequency (CBF) are conflicting, and the effect on ciliary beat pattern has not been reported. We aimed to clarify this association and determine whether cooling of cilia may allow ciliary function to be assessed without the need of expensive high-speed video microscopy. METHODS: Fourteen nasal brush biopsy samples were collected, and the CBF and beat pattern of undisrupted ciliated edges were evaluated. Two methods were used to strictly control changes in temperature: One enabled rapid transitory measurements during cooling and warming, and the other was used to maintain accurate low temperatures over longer periods of time. RESULTS: A sigmoid relationship between CBF and temperature was observed. CBF decreased with cooling and increased with warming. Ciliary function was unaffected by the direction of temperature change and was maintained down to 2°C. The percentage of dyskinetic cilia observed at 2°C or 4°C was unchanged from that at 37°C. CONCLUSIONS: Contrary to previous research, our data show that cilia continue to beat with a normal pattern at temperatures as low as 2°C. Slowing of cilia by cooling may allow detailed analysis of ciliary beat pattern without the need of expensive high-speed video microscopy.

Centriolar satellites are assembly points for proteins implicated in human ciliopathies, including oral-facial-digital syndrome 1.

Ciliopathies are caused by mutations in genes encoding proteins required for cilia organization or function. We show through colocalization with PCM-1, that OFD1 (the product of the gene mutated in oral-facial-digital syndrome 1) as well as BBS4 and CEP290 (proteins encoded by other ciliopathy genes) are primarily components of centriolar satellites, the particles surrounding centrosomes and basal bodies. RNA interference experiments reveal that satellite integrity is mutually dependent upon each of these proteins. Upon satellite dispersal, through mitosis or forced microtubule depolymerization, OFD1 and CEP290 remain centrosomal, whereas BBS4 and PCM-1 do not. OFD1 interacts via its fifth coiled-coil motif with the N-terminal coiled-coil domain of PCM-1, which itself interacts via its C-terminal non-coiled-coil region with BBS4. OFD1 localization to satellites requires its N-terminal region, encompassing the LisH motif, whereas expression of OFD1 C-terminal constructs causes PCM-1 and CEP290 mislocalization. Moreover, in embryonic zebrafish, OFD1 and BBS4 functionally synergize, determining morphogenesis. Our observation that satellites are assembly points for several mutually dependent ciliopathy proteins provides a further possible explanation as to why the clinical spectrum of OFD1, Bardet-Biedl and Joubert syndromes overlap. Furthermore, definition of how OFD1 and PCM-1 interact helps explain why different OFD1 mutations lead to clinically variable phenotypes.

Histone deacetylase inhibition attenuates cell growth with associated telomerase inhibition in high-grade childhood brain tumor cells.

Aberrant epigenetic regulation of gene expression contributes to tumor initiation and progression. Studies from a plethora of hematologic and solid tumors support the use of histone deacetylase inhibitors (HDACi) as potent anticancer agents. However, the mechanism of HDACi action with respect to the temporal order of induced cellular events is unclear. The present study investigates the anticancer effects of the HDACi trichostatin A in high-grade childhood brain tumor cells. Acute exposure to trichostatin A resulted in marked inhibition of cell proliferation, an increase in the proportion of G(2)-M cells, activation of H2A.X, and subsequent induction of apoptosis in the majority of cell lines. These phenotypic effects were associated with abrogation of telomerase activity and human telomerase reverse transcriptase downregulation in the majority of cell lines. In contrast, no cytotoxicity was observed in primary ependymal cells with respect to cilia function. Thus, inhibition of histone deacetylases leads to antiproliferative and proapoptotic effects in childhood brain tumor cells, likely to involve altered chromatin regulation at the human telomerase reverse transcriptase promoter.

Ciliated air-liquid cultures as an aid to diagnostic testing of primary ciliary dyskinesia.

BACKGROUND: The diagnosis of primary ciliary dyskinesia (PCD) can prove difficult because of secondary damage of ciliated tissue. METHODS: Here we audit culturing cells, obtained by nasal brushing, to a ciliated phenotype using an air-liquid interface method to determine if the effects of secondary damage on cilia were reduced following culture. RESULTS: Of 231 patients consecutively referred for diagnostic testing, culture was attempted in 187, with 101 (54%) becoming ciliated. Of the 90 brush biopsy samples with a low dyskinesia score (< 40%), 71 grew cilia after culture (79% success). Significant secondary damage (> 40% dyskinesia) was present in 69 (43%) of the initial brush biopsy samples, and of these, 18 (26%) became ciliated after culture. In these samples, ciliary dyskinesia was significantly (P < .001) reduced (64% ± 6.8% before culture, 31% ± 4.5% after culture). Ciliary beat frequency (CBF) after cell culture was similar to CBF before culture. Cell culture helped to exclude PCD in eight patients for whom ciliary dyskinesia was present in > 70% of the initial brush biopsy sample, a level at which a rebiopsy would normally be requested. In six patients in whom no cilia were found in the initial brush biopsy samples, ciliated cell culture was successful and excluded the diagnosis. PCD was diagnosed in 28 patients and ciliated cell culture was successful in 12 (43%) showing identical ciliary beat pattern and electron microscopy findings. CONCLUSIONS: Ciliary dyskinesia was reduced following cell culture to a ciliated phenotype compared with the initial brush biopsy sample. The specific PCD phenotype was maintained after culture.

Hydrogen peroxide at a concentration used during neurosurgery disrupts ciliary function and causes extensive damage to the ciliated ependyma of the brain.

OBJECTIVES: Hydrogen peroxide [H(2)O(2): 3% w/v (1.1 M)] has been used as a haemostatic agent during neurosurgery applied to both the external and ventricular surface of the brain. We hypothesised that H(2)O(2) would be toxic to the ciliated ependyma, a single layer of cells that separates cerebrospinal fluid from the neuronal tissue of the brain. MATERIALS AND METHODS: The effect of H(2)O(2) was assessed by determining ependymal ciliary beat frequency (CBF) using high-speed video analysis and ultrastructure by electron microscopy. RESULTS: Brief exposure to H(2)O(2) caused cessation of ciliary beat frequency and extensive damage of the ependyma. CONCLUSIONS: Damage to the ciliated ependyma is of concern, as regeneration following damage is very poor and if breached underlying neuronal tissue and a population of neuronal progenitor cells that lie immediately beneath may also be exposed to H(2)O(2).

Measurement of [Ca²+]i in whole cell suspensions using fura-2.

An elevation in intracellular calcium concentration ([Ca(2+)](i)) acts to trigger a range of cellular events including neurotransmitter release, muscle contraction, and oocyte fertilization. The pattern of elevation in [Ca(2+)](i) and response to that elevation is dependent on the agonist and the cell type.