Decrease In Ciliary Beat Frequency Research Articles

Bronchial Asthma and Mucociliary Clearance - A Bidirectional Relationship

: The integrity of the airway epithelium plays an important role in the defence against pathogens and various immunogenic stimuli from the external environment. Properly functioning mucociliary clearance is an indispensable part of the respiratory system defence and it relies on adequate viscoelastic properties of mucus, as well as the intact function of a significant number of healthy ciliated cells. The movement of the cilia can be affected by many endogenous and exogenous factors. Complex mucociliary clearance dysfunction can be seen as a part of the respiratory system inflammation. Bronchial asthma is one of the most common inflammatory diseases of the respiratory system. It is characterised by structural and functional changes in the airways. The last decades of bronchial asthma research point to asthmatic inflammation as the cause of airway remodelling with subsequent impairment of mucociliary transport function. Changes in the respiratory epithelium in patients with bronchial asthma include hypertrophy of secretory cells, overproduction of mucus, increase in mucus viscosity, decline of ciliated cells, decrease of ciliary beat frequency, and more. Cytokines of T2-high type of asthmatic inflammation, such as interleukin IL-13 and IL-4, have been shown to contribute to these changes in the airway epithelium significantly. There is strong evidence of cytokine-induced overexpression of important transcription factors, which results in hyper- and metaplasia of secretory cells and also transdifferentiation of ciliary cells. Impaired mucociliary clearance increases the risk of airway infection and contributes to the worsening of bronchial asthma control.

Tacrolimus impairs airway mucociliary clearance of rats

ObjectivesTacrolimus (TAC) is the most widely used immunosuppressive agent after lung transplantation. Considering that the ciliary beat frequency (CBF) mainly depends on the cytoplasmic calcium concentration and that TAC can affect this due to its binding with the intracellular immunophilin FKBP12, we hypothesized that TAC could also impair the airway mucociliary clearance of rats. MethodsSixty rats were divided into two groups (n = 30 each): Control = water; TAC = tacrolimus. After 7, 15 or 30 days of treatment, ten animals from each group were euthanized and the following parameters were studied: mucus transportability, CBF, mucociliary transport velocity (MCTV), and neutral and acid mucus production. ResultsThere was a significant decrease in CBF (Control vs TAC: 7 days, p = 0.008; 15 days, p = 0.007; 30 days, p = 0.001) and MCTV (Control vs TAC: 7 days, p = 0.004; 15 days, p < 0.001; 30 days, p < 0.001) in all immunosuppressed animals. TAC therapy also caused an increase in acid mucus production at all treatment times (Control vs TAC: 7 days, p = 0.001; 15 days, p = 0.043; 30 days, p = 0.001). ConclusionsTAC impairs airway mucociliary clearance of rats.

ODAD1 variants resulting from splice-site mutations retain partial function and cause primary ciliary dyskinesia with outer dynein arm defects.

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder caused by defects in motile ciliary function and/or structure. Outer dynein arm docking complex subunit 1 (ODAD1) is an important component of the outer dynein arm docking complex (ODA-DC). To date, 13 likely pathogenic mutations of ODAD1 have been reported. However, the pathogenesis of ODAD1 mutations remains elusive. To investigate the pathogenesis of splice-site mutations in ODAD1 discovered in this study and those reported previously, molecular and functional analyses were performed. Whole-exome sequencing revealed a compound mutation in ODAD1 (c.71-2A>C; c.598-2A>C) in a patient with PCD, with c.598-2A>C being a novel mutation that resulted in two mutant transcripts. The compound mutation in ODAD1 (c.71-2A>C; c.598-2A>C) led to aberrant splicing that resulted in the absence of the wild-type ODAD1 and defects of the outer dynein arm in ciliary axonemes, causing a decrease in ciliary beat frequency. Furthermore, we demonstrated that the truncated proteins resulting from splice-site mutations in ODAD1 could retain partial function and inhibit the interaction between wild-type ODAD1 and ODAD3. The results of this study expand the mutational and clinical spectrum of PCD, provide more evidence for genetic counseling, and offer new insights into gene-based therapeutic strategies for PCD.

Influenza virus reduces ubiquitin E3 ligase MARCH10 expression to decrease ciliary beat frequency.

Respiratory viruses, such as influenza, decrease airway cilia function and expression, which leads to reduced mucociliary clearance and inhibited overall immune defense. Ubiquitination is a posttranslational modification using E3 ligases, which plays a role in the assembly and disassembly of cilia. We examined the role of membrane-associated RING-CH (MARCH) family of E3 ligases during influenza infection and determined that MARCH10, specifically expressed in ciliated epithelial cells, is significantly decreased during influenza infection in mice, human lung epithelial cells, and human lung tissue. Cellular depletion of MARCH10 in differentiated human bronchial epithelial cells (HBECs) using CRISPR/Cas9 showed a decrease in ciliary beat frequency. Furthermore, MARCH10 cellular knockdown in combination with influenza infection selectively decreased immunoreactive levels of the ciliary component, dynein axonemal intermediate chain 1. Cellular overexpression of MARCH10 significantly decreased influenza hemagglutinin protein levels in the differentiated HBECs and knockdown of MARCH10 increased IL-1β cytokine expression, whereas overexpression had the reciprocal effect. These findings suggest that MARCH10 may have a protective role in airway pulmonary host defense and innate immunity during influenza infection.

Nebulized Menthol Impairs Mucociliary Clearance via TRPM8 and MUC5AC/MUC5B in Primary Airway Epithelial Cells.

Flavorings enhance the palatability of e-cigarettes (e-cigs), with menthol remaining a popular choice among e-cig users. Menthol flavor remains one of the only flavors approved by the United States FDA for use in commercially available, pod-based e-cigs. However, the safety of inhaled menthol at the high concentrations used in e-cigs remains unclear. Here, we tested the effects of menthol on parameters of mucociliary clearance (MCC) in air-liquid interface (ALI) cultures of primary airway epithelial cells. ALI cultures treated with basolateral menthol (1 mM) showed a significant decrease in ciliary beat frequency (CBF) and airway surface liquid (ASL) volumes after 24 h. Menthol nebulized onto the surface of ALI cultures similarly reduced CBF and increased mucus concentrations, resulting in decreased rates of mucociliary transport. Nebulized menthol further increased the expression of mucin 5AC (MUC5AC) and mRNA expression of the inflammatory cytokines IL1B and TNFA. Menthol activated TRPM8, and the effects of menthol on MCC and inflammation could be blocked by a specific TRPM8 antagonist. These data provide further evidence that menthol at the concentrations used in e-cigs could cause harm to the airways.

Capsaicin suppresses ciliary function, while inducing permeability in bronchial epithelial cell cultures of COPD patients.

Take Home Message: Capsaicin modified inflammatory response and caused toxicity in bronchial epithelial cultures from patients with COPD. More importantly, capsaicin decreased ciliary beat frequency and induced epithelial permeability and these effects were partially prevented by formoterol and roflumilast.Tear gas is widely used to halt mass demonstrations. Studies have reported its adverse effects on multiple organ systems; however, its effect on individuals with chronic respiratory diseases and the underlying mechanisms of these effects are unclear. For the first time in the literature, we investigated the effects of capsaicin, the active ingredient of tear gas, on bronchial epithelial cell (BEC) cultures obtained from well-characterized groups of nonsmokers, smokers, and patients with chronic obstructive pulmonary disease (COPD). BEC cultures were incubated with 50-500 μM capsaicin in the absence and presence of formoterol (1μM) and roflumilast (0.1 μM) for 24 h. Ciliary beat frequency (CBF) and transepithelial electrical resistance (TEER) were assessed at T1/4, T1/2, T1, T2, T4, T6, and T24 h, whereas the release of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-8, and lactate dehydrogenase (LDH) was measured at T24 h. Capsaicin (250 µM) significantly decreased CBF of all BEC cultures from T1/4 h to T24 h (p<0.05). Formoterol significantly prevented decreases in CBF induced by capsaicin. Higher concentrations of capsaicin (250-500 μM) significantly reduced TEER of BECs from nonsmokers (T2-T24 h), smokers (T24 h) and COPD patients (T2 and T24 h), which was partially prevented by roflumilast. Capsaicin (500 μM) decreased release of IL-8 (p<0.0001) and GM-CSF (p<0.05) while inducing release of LDH in BECs (p<0.05), and this was more prominent in BEC from patients with COPD. In conclusion, our findings demonstrate that capsaicin can suppress ciliary activity and cytokine release from BECs, induce BEC culture permeability and cellular toxicity and that these effects can be partially prevented by formoterol and roflumilast.

The effects of intermittent hypoxia on human nasal mucosa.

PurposeIntermittent hypoxia (IH) is characterized by hypoxia-reoxygenation, reported to be a critical risk factor for obstructive sleep apnea (OSA). This experiment aimed to evaluate the direct effects of IH on the human nasal mucosa.MethodsThe direct effects of IH on the human nasal mucosa was evaluated by measuring the ciliary beat frequency (CBF) and expression levels of inflammatory cytokines (granulocyte-macrophage colony-stimulating factor, transforming growth factor-β, interleukin-6, and tumor necrosis factor-α). The normoxia group was exposed to a normoxic condition for 72 h. The IH group was exposed to 288 cycles of IH (1 cycle: hypoxia, 5 min; subsequent normoxia, 10 min) for 72 h. CBF was measured using an automated computer-based video image processing technique. Changes in the expression of cytokines were assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR).ResultsThe normoxia group revealed a persistent CBF pattern and a physiological range of inflammatory cytokines. However, the IH group showed a cyclic decrease in CBF and increased expression of inflammatory cytokines. Cytotoxicity assay indicated no difference in the survival rates between the two groups.ConclusionsIH results in increased expression of inflammatory cytokines that adversely affects the mucociliary transport in the upper airway and, consequently, may result in airway inflammation.

Airway Ciliary Beating Affected by the Pcp4 Dose-Dependent [Ca2+]i Increase in Down Syndrome Mice, Ts1Rhr

In Ts1Rhr, a Down syndrome model mouse, the airway ciliary beatings are impaired; that is, decreases in ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of ciliary beat amplitude)). A resumption to two copies of the Pcp4 gene on the Ts1Rhr trisomic segment (Ts1Rhr:Pcp4+/+/-) rescues the decreases in CBF and CBA that occur in Ts1Rhr. In airway cilia, upon stimulation with procaterol (a β2-agonist), the CBF increase is slower over the time course than the CBA increase because of cAMP degradation by Ca2+/calmodulin-dependent phosphodiesterase 1 (PDE1) existing in the metabolon regulating CBF. In Ts1Rhr, procaterol-stimulated CBF increase was much slower over the time course than in the wild-type mouse (Wt) or Ts1Rhr:Pcp4+/+/-. However, in the presence of 8MmIBMX (8-methoxymethyl isobutylmethyl xanthine, an inhibitor of PDE1) or calmidazolium (an inhibitor of calmodulin), in both Wt and Ts1Rhr, procaterol stimulates CBF and CBA increases over a similar time course. Measurements of cAMP revealed that the cAMP contents were lower in Ts1Rhr than in Wt or in Ts1Rhr:Pcp4+/+/-, suggesting the activation of PDE1A that is present in Ts1Rhr airway cilia. Measurements of the intracellular Ca2+ concentration ([Ca2+]i) in airway ciliary cells revealed that temperature (increasing from 25 to 37 °C) or 4αPDD (a selective transient receptor potential vanilloid 4 (TRPV4) agonist) stimulates a larger [Ca2+]i increase in Ts1Rhr than in Wt or Ts1Rhr:Pcp4+/+/-. In airway ciliary cells of Ts1Rhr, Pcp4-dose dependent activation of TRPV4 appears to induce an increase in the basal [Ca2+]i. In early embryonic day mice, a basal [Ca2+]i increased by PCP4 expressed may affect axonemal regulatory complexes regulated by the Ca2+-signal in Ts1Rhr, leading to a decrease in the basal CBF and CBA of airway cilia.

Hypertonic saline and seawater solutions damage sinonasal epithelial cell air-liquid interface cultures.

Nasal irrigation (NI) is commonly used to treat several sinonasal diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP); however, the effects of NI on the sinonasal epithelium are not fully known. The aim of this study was to investigate the effects of commonly used NI solutions on epithelial mucociliary and barrier functionality in primary cultured human nasal epithelial cells (HNECs). HNECs from control subjects and patients with CRSwNP were established as air-liquid interface (ALI) cultures. Differentiated cultures were treated with different NI solutions, including isotonic 0.9% and hypertonic 3.0% saline, isotonic and hypertonic seawater, and Ringer lactate solution. The changes in ciliary beat frequency (CBF), numbers of ciliated and goblet cells, and cytotoxicity were measured. Epithelial barrier functionality was assessed by measuring the transepithelial electric resistance (TER), paracellular flux, and expression of tight junction protein zonula occludens-1 (ZO-1) and occludin. Isotonic saline, isotonic seawater, and Ringer lactate solutions did not affect epithelial mucociliary and barrier function in either control or CRSwNP-derived ALI cultures; however, hypertonic saline induced a significant disruption of these cell functions in both cultures. Hypertonic seawater caused a transient decrease of CBF and TER in CRSwNP-derived ALI cultures, in contrast to inducing an obvious mucociliary and barrier dysfunction and cytotoxicity in control ALI cultures. Although isotonic NI solutions appear to not affect epithelial mucociliary and barrier function in control and CRSwNP-derived ALI cultures, hypertonic saline and seawater solutions damaged sinonasal epithelial cells in ALI cultures. The safety and efficacy of these solutions requires further investigation.

A pilot study exploring the impact of cardiac medications on ciliary beat frequency: possible implications for clinical management.

Abstract Background Cilia are involved in several physiologic processes, and at least a single primary cilium can be found on nearly every cell in the human body. Various factors, such as pH, temperature, exposure to medications and toxins can impact ciliary function as is manifested by changes in the ciliary beat frequency. Those with ciliary dyskinesia may also have congenital cardiac malformations and may require care in a cardiac intensive care unit. This study investigates the effect on the ciliary beat frequency of medications frequently used in a cardiac intensive care unit. Methods The ciliated epithelial cells were obtained via nasal swab from a relatively healthy individual. These cells were cultured for 24 h. Video microscopy was then employed to determine the ciliary beat frequency at baseline and then at 15, 30, 60 and 90 min after exposure to either normal saline (control) or one of several medications. The ciliary beat frequency at each time point was then compared to the ciliary beat frequency at the same time point in the control sample as well as the baseline value for that particular sample. Results Epinephrine increased the ciliary beat frequency compared to the baseline and the controls up to 30 min and then subsequently led to a significant decrease in ciliary beat frequency at 90 min. On the one hand, norepinephrine, dexmedetomidine, procainamide, propranolol and enalapril all decreased ciliary beat frequency significantly throughout the 90-min observation period. On the other hand, Milrinone significantly increased the ciliary beat frequency throughout the observation period, while heparin had no impact on ciliary beat frequency. Conclusions The medications frequently used in cardiac intensive care unit impact ciliary function, with most being ciliodepressant. Further investigation is needed to determine the clinical impacts and whether these effects are exaggerated in those with ciliary dyskinesia.

Mupirocin reduces ciliary beat frequency of human nasal epithelial cells.

Mupirocin is used worldwide for topical treatment of infected skin lesions, impetigo, and especially for nasal decolonization of patients with carriage of Staphylococci, including methicillin-resistant Staphylococcus aureus. Nevertheless, data regarding the effects of mupirocin on the nasal mucosa, in particular on ciliary beat frequency (CBF), is lacking to date. We tested the CBF of ciliated nasal epithelial cells under the influence of Mupirocin-calcium dissolved in tert-butyl alcohol (TBA) containing media in different concentrations comparable to clinical use. Ringer's lactate solution and TBA served as negative control. Cells were visualized with a phase contrast microscope, and the CBF was measured with the SAVA system's region of interest method. Mupirocin-calcium dissolved in TBA led to a statistically significant time- and concentration-dependent decrease in CBF compared to the negative control. TBA addition without mupirocin also led to a significant decrease in CBF, although to a lesser extent than mupirocin/TBA. In conclusion, CBF of human nasal epithelia is significantly reduced by mupirocin-calcium-containing solutions in therapeutic concentrations. Due to our results in this study, mupirocin as a nasal decolonization agent should be used only with care, with a strictly set medical indication, and additional care measures should be considered.

TNFα Affects Ciliary Beat Response to Increased Viscosity in Human Pediatric Airway Epithelium.

In airway epithelium, mucociliary clearance (MCC) velocity depends on the ciliary beat frequency (CBF), and it is affected by mucus viscoelastic properties. Local inflammation induces secretion of cytokines (TNFα) that can alter mucus viscosity; however airway ciliated cells have an autoregulatory mechanism to prevent the collapse of CBF in response to increase in mucus viscosity, mechanism that is associated with an increment in intracellular Ca+2 level ([Ca2+]i). We studied the effect of TNFα on the autoregulatory mechanism that regulates CBF in response to increased viscosity using dextran solutions, in ciliated cells cultured from human pediatric epithelial adenoid tissue. Cultures were treated with TNFα, before and after the viscous load was changed. TNFα treatment produced a significantly larger decrease in CBF in cultures exposed to dextran. Furthermore, an increment in [Ca2+]i was observed, which was significantly larger after TNFα treatment. In conclusion, although TNFα has deleterious effects on ciliated cells in response to maintaining CBF after increasing viscous loading, it has a positive effect, since increasing [Ca2+]i may prevent the MCC collapse. These findings suggest that augmented levels of TNFα associated with an inflammatory response of the nasopharyngeal epithelium may have dual effects that contribute to maintaining the effectiveness of MCC in the upper airways.

Ulipristal Acetate Antagonizes the Inhibitory Effect of Progesterone on Ciliary Beat Frequency and Upregulates Steroid Receptor Expression Levels in Human Fallopian Tubes.

Ulipristal acetate (UPA) is a new selective progesterone receptor (PR) modulator used for emergency contraception. However, our understanding of its mechanisms of action on oviductal cilia is limited. The present study focused on the in vitro effects of UPA (0.1, 1, and 10 μmol/L) on the cilia and steroid receptors of human fallopian tubes. The ciliary beat frequency (CBF), the ultrastructure of cilia, and the levels of steroid receptors were measured. The effects of UPA on the progesterone-induced CBF reduction were also studied. Our results show that UPA dose dependently antagonizes the progesterone-induced CBF decrease, but it does not affect the CBF or the ultrastructure of the cilia. The UPA also upregulates the expression levels of the estrogen receptor α and the PR in the fallopian tubes. The results enable us to better understand the mechanisms by which UPA works as an emergency contraceptive and provides a scientific basis for its clinical application.

Levonorgestrel decreases cilia beat frequency of human fallopian tubes and rat oviducts without changing morphological structure.

SummaryLevonorgestrel, a derivative of progesterone, effectively protects women against unwanted pregnancy as an emergency contraceptive. Previous studies have not been successful in determining the mechanism by which levonorgestrel acts. In the present study we analysed cilia beat action and cilia morphology following levonorgestrel exposure in vitro and in vivo using both light and electron microscopy. There was a significant decrease in the ciliary beat frequency (CBF) of human fallopian tubes between mucosal explants bathed in 5 μmol/L levonorgestrel and those bathed in medium alone (P < 0.05). There was a tendency for CBF to decrease more in the ampulla than in isthmus, but there were no differences between the proliferative and secretory phases. In rat oviducts, levonorgestrel produced a similar reduction in CBF (~ 10%) compared with the saline control group (P < 0.05). Histological and ultrastructural analysis demonstrated no changes in the percentage of ciliated cells or in the classic ‘9 + 2’ structure of cilia following levonorgestrel treatment in either system. Thus, levonorgestrel reduces CBF without damaging cilia morphology. Decreases in CBF may indicate a pathological role for levonorgestrel in the transportation of the ovum and zygote in the fallopian tube.

A Soluble Adenylyl Cyclase Form Targets to Axonemes and Rescues Beat Regulation in Soluble Adenylyl Cyclase Knockout Mice

Ciliary beating is important for effective mucociliary clearance. Soluble adenylyl cyclase (sAC) regulates ciliary beating, and a roughly 50-kD sAC variant is expressed in axonemes. Normal human bronchial epithelial (NHBE) cells express multiple sAC splice variants: full-length sAC; variants with catalytic domain 1 (C1) deletions; and variants with partial C1. One variant, sACex5v2-ex12v2, contains two alternative splices creating new exons 5 (ex5v2) and 12 (ex12v2), encoding a roughly 45-kD protein. It is therefore similar in size to ciliary sAC. The variant increases in expression upon ciliogenesis during differentiation at the air-liquid interface. When expressed in NHBE cells, this variant was targeted to cilia. Exons 5v2-7 were important for ciliary targeting, whereas exons 2-4 prevented it. In vitro, cytoplasmic sACex2-ex12v2 (containing C1 and C2) was the only variant producing cAMP. Ciliary sACex5v2-ex12v2 was not catalytically active. Airway epithelial cells isolated from wild-type mice revealed sAC-dependent ciliary beat frequency (CBF) regulation, analogous to NHBE cells: CBF rescue from HCO3(-)/CO2-mediated intracellular acidification was sensitive to the sAC inhibitor, KH7. Compared with wild type, sAC C2 knockout (KO) mice revealed lower CBF baseline, and the HCO3(-)/CO2-mediated CBF decrease was not inhibited by KH7, confirming lack of functional sAC. Human sACex5v2-ex12v2 was targeted to cilia and sACex2-ex12v2 to the cytoplasm in these KO mice. Introduction of the ciliary sACex5v2-ex12v2 variant, but not the cytoplasmic sACex2-ex12v2, restored functional sAC activity in C2 KO mice. Thus, we show, for the first time, a mammalian axonemal targeting sequence that localizes a sAC variant to cilia to regulate CBF.

Linking increased airway hydration, ciliary beating, and mucociliary clearance through ENaC inhibition.

Airway dehydration causes mucus stasis and bacterial overgrowth in cystic fibrosis and chronic bronchitis (CB). Rehydration by hypertonic saline is efficacious but suffers from a short duration of action. We tested whether epithelial sodium channel (ENaC) inhibition would rehydrate normal and dehydrated airways to increase mucociliary clearance (MCC) over a significant time frame. For this, we used a tool compound (Compound A), which displays nanomolar ENaC affinity and retention in the airway surface liquid (ASL). Using normal human bronchial epithelial cultures (HBECs) grown at an air-liquid interface, we evaluated in vitro potency and efficacy using short-circuit current (I(sc)) and ASL height measurements where it inhibited I(sc) and increased ASL height by ∼ 50% (0.052 μM at 6 h), respectively. The in vivo efficacy was investigated in a modified guinea pig tracheal potential difference model, where we observed an effective dose (ED50) of 5 μg/kg (i.t.), and by MCC measures in rats and sheep, where we demonstrated max clearance rates at 100 μg/kg (i.t.) and 75 μg/kg (i.t.), respectively. Acute cigarette smoke-induced ASL height depletion in HBECs was used to mimic the situation in patients with CB, and pretreatment prevented both cigarette smoke-induced ASL dehydration and lessened the decrease in ciliary beat frequency. Furthermore, when added after cigarette smoke exposure, Compound A increased the rate of ASL rehydration. In conclusion, Compound A demonstrated significant effects and a link between increased airway hydration, ciliary function, and MCC. These data support the hypothesis that ENaC inhibition may be efficacious in the restoration of mucus hydration and transport in patients with CB.

The Effect of Topical Corticosteroids, Topical Antihistamines, and Preservatives on Human Ciliary Beat Frequency

Background: The aim of this study was to investigate the effect of the corticosteroids, the antihistamines, and the preservatives benzalkonium chloride (BKC) and potassium sorbate (PS) in intranasal medications on human nasal epithelial ciliary beat frequency (CBF). Methods: Primary ciliated epithelial cell cultures from the human nasal mucosa of chronic sinusitis patients were established. Changes in CBF of epithelial cell cultures treated/untreated with intranasal medications or preservatives were assessed using high-speed digital imaging methods. Results: Budesonide caused a rapid but reversible ciliostasis and showed no ciliotoxic effect at 10% dilution. Fluticasone propionate induced an irreversible ciliostatic activity and showed a reversible decrease in CBF at 10% dilution. Azelastine hydrochloride and levocabastine hydrochloride both induced a dose-dependent and irreversible decrease in CBF, although the ciliotoxic effect was not evident at 5% dilution. BKC resulted in an irreversible ciliostasis at 0.005 or 0.01% concentrations, whereas PS did not show any change in CBF at 0.12 or 0.24% concentrations. Conclusions: Crystalline BKC and BKC-containing intranasal medications, including fluticasone propionate, azelastine hydrochloride and levocabastine hydrochloride, but not PS or PS-containing intranasal budesonide spray, led to irreversible ciliostasis in human nasal epithelial cell cultures when applied at clinically relevant concentrations.

Aging causes a slowing in ciliary beat frequency, mediated by PKCε

The elderly are at much higher risk for developing pneumonia than younger individuals. Pneumonia is a leading cause of death and is the third most common reason for hospitalization in the elderly. One reason that elderly people may be more susceptible to pneumonia is a breakdown in the lung's first line of defense, mucociliary clearance. Cilia beat in a coordinated manner to propel out invading microorganisms and particles. Ciliary beat frequency (CBF) is known to slow with aging, however, little is known about the mechanism(s) involved. We compared the CBF in BALB/c and C57BL/6 mice aged 2, 12, and 24 mo and found that CBF diminishes with age. Cilia in the mice at age 12 and 24 mo retained their ability to be stimulated by the β2 agonist procaterol. To help determine the mechanism of ciliary slowing, we measured protein kinase C alpha and epsilon (PKCα and PKCε) activity. There were no activity differences in PKCα between the mice aged 2, 12, or 24 mo. However, we demonstrated a significantly higher PKCε activity in the mice at 12 and 24 mo than the in the mice 2 mo of age. The increase in activity is likely due to a nearly threefold increase in PKCε protein in the lung during aging. To strengthen the connection between activation of PKCε and ciliary slowing, we treated tracheas of mice at 2 mo with the PKCε agonist 8-[2-(2-pentylcyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA). We noted a similar decrease in baseline CBF, and the cilia remained sensitive to stimulation with β2 agonists. The mechanisms for the slowing of baseline CBF have not been previously determined. In this mouse model of aging we were able to show that decreases in CBF are related to an increase in PKCε activity.

The effects of vitamins C and B12 on human nasal ciliary beat frequency

BackgroundThis study was designed to investigate the effects of the vitamins C and B12 on the regulation of human nasal ciliary beat frequency (CBF).MethodsHuman nasal mucosa was removed endoscopically and nasal ciliated cell culture was established. Changes of CBF in response to different concentrations of vitamin C or vitamin B12 were quantified by using high-speed (240 frames per second) digital microscopy combined with a beat-by-beat CBF analysis.ResultsAt the concentrations of 0.01% and 0.10%, vitamin C induced an initial increase, followed by a gradual decrease of CBF to the baseline level, while 1.00% vitamin C induced a reversible decrease of CBF. Vitamin B12, at the concentrations of 0.01% and 0.10%, did not influence CBF during the 20-min observation period, while a 1.00% vitamin B12 treatment caused a time-dependent but reversible decrease of CBF.ConclusionsTreatment with vitamin C or vitamin B12 caused a concentration-dependent but reversible decrease of CBF in cultured human nasal epithelial cells. Therefore, it is necessary to choose a concentration that is safe, effective, and non-ciliotoxic when applying these drugs topically in the nasal cavity.

Decreases in adrenomedullin expression and ciliary beat frequency in the nasal epithelium in tubal pregnancy

To study adrenomedullin (ADM) expression and its relation to ciliary beat frequency (CBF) in the nasal mucociliated epithelium in tubal ectopic pregnancy (tEP). Experimental study. University teaching hospital. Women with tEP and normal intrauterine pregnancy matched for age and gestational age were recruited. Healthy nonpregnant women were also recruited as nonpregnant controls. Nasal epithelial brushing. Adrenomedullin expression in nasal epithelium (measured by real-time reverse transcription-polymerase chain reaction, plasma ADM concentration (measured by ELISA), and CBF (measured by photometric method). We have demonstrated a similar decrease in ADM expression and CBF in the nasal mucociliated epithelium, as well as in plasma ADM concentration, in women with tEP compared with normal pregnant women. Adrenomedullin up-regulates nasal CBF via the ADM receptor, as in the oviduct. There is significant correlation between nasal and oviductal CBF. Nasal epithelium ADM and CBF, as well as plasma ADM, are possible predictors of women at risk of tEP.