Density Of Ciliated Cells Research Articles

Morphological and pathological changes of Eustachian tube mucosa in an animal model of eosinophilic otitis media

IntroductionEosinophilic otitis media is an intractable otitis media and a fairly common middle ear disease. However, the pathogenesis of eosinophilic otitis media is obscure. ObjectiveTo observe the pathological and ultrastructural changes of the Eustachian tube mucosal epithelium in rats with eosinophilic otitis media and further explore the pathogenesis of eosinophilic otitis media. MethodsAnimals were intraperitoneally injected with 2000 mg ovalbumin and 100 mg aluminum hydroxide (alum) on day 0, followed by 100 mg ovalbumin and 100 mg alum injection on days 7 and 14. Next they were topically boosted by daily application of 100 mg ovalbumin solution via nasal drip and intratympanic injection of 0.1 mL ovalbumin (1000 mg/mL) in the right ear (group A, n = 80) and 0.1 mL saline in the left ear as control (group B, n = 80) starting on day 21 and continuing for 14 days. The temporal bones were dissected on the 35th, 38th, 41st and 43rd day separately under anesthesia. Scanning electron microscopy, hematoxylin-eosin and toluidine blue staining were used to observe the pathological and morphological changes of Eustachian tube mucosa stained samples. Moreover, inflammatory cells and cilia were counted. ResultsThe epithelium of the Eustachian tube in group A was swollen and thickened. The cilia were arranged in a disorderly manner and partially detached. Eosinophils infiltrated the submucosal layer of the Eustachian tube, and their number increased significantly compared with that in group B (p < 0.05). Simultaneously, mast cell degranulation was observed in group A. Scanning electron microscopy revealed that the cilia were lodged and gathered along the whole length of Eustachian tube in group A. Ciliated cell density was significantly lower than that in Group B (p < 0.01). ConclusionIn the eosinophilic otitis media model, allergy caused significant changes in pathology and morphology of the Eustachian tube mucosa, affecting the normal function of the Eustachian tube which played an important role in the occurrence and development of eosinophilic otitis media.

Spatiotemporal organization of cilia drives multiscale mucus swirls in model human bronchial epithelium

Mucociliary clearance is a biomechanical mechanism of airway protection. It consists of the active transport along the bronchial tree of the mucus, a fluid propelled by the coordinated beating of a myriad of cilia on the epithelial surface of the respiratory tract. The physics of mucus transport is poorly understood because it involves complex phenomena such as long-range hydrodynamic interactions, active collective ciliary motion, and the complex rheology of mucus. We propose a quantitative physical analysis of the ciliary activity and mucus transport on a large panel of human bronchial cultures from control subjects, patients with asthma and chronic obstructive pulmonary disease obtained from endobronchial biopsies. Here we report on the existence of multiple ciliary domains with sizes ranging from the tens of a micron to the centimeter, where ciliary beats present a circular orientational order. These domains are associated with circular mucus flow patterns, whose size scales with the average cilia density. In these domains, we find that the radial increase of the ciliated cell density coupled with the increase in the orientational order of ciliary beats result in a net local force proportional to the mucus velocity. We propose a phenomenological physical model that supports our results.

Morphology and Ciliary Motion of the Middle Ear Mucosa of Neonatal and Adult Gerbils

Background/Aims: Since the middle ear cavity plays an important role in middle ear effusion, the goal of this study is to examine the morphological and functional development of the middle ear mucosa in neonatal and adult gerbils. Methods: Gerbils aged between postnatal day 1 (P1) and P26 were used for the experiments. The morphological development of the middle ear cavity was measured by using the celloidin embedding method and scanning electronic microscope. Ciliary motion was determined and calibrated by a photodiode-based measurement system. Results: The area of the middle ear increased significantly from 0.42 ± 0.02 mm² (n = 8) at P1 to 2.6 ± 0.03 mm² (n = 8) at P26. At P1, all regions were covered by densely populated ciliated cells. A significant reduction of the density of ciliated cells was found between P8 and P18 (p < 0.05). The beat frequency at P1 is not statistically different from that of P8 (p > 0.05). However, the beat frequency increased significantly between P8 and P18 (p < 0.05). Conclusion: Middle ear mucosa underwent a significant change between P1 and P18. The cilia morphology and function (ciliary motion) are fully mature at P18. This may explain the high incidence of middle ear effusion in the neonatal period in humans.

Comparison of human nasal epithelial cells grown as explant outgrowth cultures or dissociated tissue cultures in vitro

The purpose of this study was to compare cell growth characteristics, ciliated cell differentiation, and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures. Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods. Epithelial cell growth characteristics were observed by inverted phase contrast microscopy. Ciliated cell differentiation was detected by β-tubulin IVand ZO-1 immunocytochemistry. Basal and ATP-stimulated ciliary beat frequency (CBF) was measured using a highspeed digital microscopic imaging system. Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition, with both types of cultures comprising ciliated and non-ciliated epithelial cells. Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures. In both culture systems, the highest ciliated cell density appeared at 7th-10th culture day and declined with time, with the lifespan of ciliated cells ranging from 14 to 21 days. Overall, 10% of the cells in explant cultures and 20% of the cells in the dissociated tissue cultures were ciliated. These two cultures demonstrated similar ciliary beat frequency values at baseline (7.78 ± 1.99 Hz and 7.91 ± 2.52 Hz, respectively) and reacted equivalently following stimulation with 100 μM ATP. The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells, which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo.

Deletion of the Parkin co-regulated gene causes defects in ependymal ciliary motility and hydrocephalus in the quakingviable mutant mouse

The quakingviable mouse (qkv) is a spontaneous recessive mouse mutant with a deletion of approximately 1.1 Mb in the proximal region of chromosome 17. The deletion affects the expression of three genes; quaking (Qk), Parkin-coregulated gene (Pacrg) and parkin (Park2). The resulting phenotype, which includes dysmyelination of the central nervous system and male sterility, is due to reduced expression of Qk and a complete lack of Pacrg expression, respectively. Pacrg is required for correct development of the spermatozoan flagella, a specialized type of motile cilia. In vertebrates, motile cilia are required for multiple functions related to cellular movement or movement of media over a stationary cell surface. To investigate the potential role of PACRG in motile cilia we analysed qkv mutant mice for evidence of cilial dysfunction. Histological and magnetic resonance imaging analyses demonstrated that qkv mutant mice were affected by acquired, communicating hydrocephalus (HC). Structural analysis of ependymal cilia demonstrated that the 9 + 2 arrangement of axonemal microtubules was intact and that both the density of ciliated cells and cilia length was similar to wild-type littermates. Cilia function studies showed a reduction in ependymal cilial beat frequency and cilial mediated flow in qkv mutant mice compared with wild-type littermate controls. Moreover, transgenic expression of Pacrg was necessary and sufficient to correct this deficit and rescue the HC phenotype in the qkv mutant. This study provides novel in vivo evidence that Pacrg is required for motile cilia function and may be involved in the pathogenesis of human ciliopathies, such as HC, asthenospermia and primary ciliary dyskinesia.

Initiation and maturation of cilia-generated flow in newborn and postnatal mouse airway

Mucociliary clearance in the adult trachea is well characterized, but there are limited data in newborns. Cilia-generated flow was quantified across longitudinal sections of mouse trachea from birth through postnatal day (PND) 28 by tracking fluorescent microsphere speed and directionality. The percentage of ciliated tracheal epithelial cells, as determined by immunohistochemistry, was shown to increase linearly between PND 0 and PND 21 (R(2) = 0.94). While directionality measurements detected patches of flow starting at PND 3, uniform flow across the epithelia was not observed until PND 7 at a approximately 35% ciliated cell density. Flow became established at a maximal rate at PND 9 and beyond. A linear correlation was observed between the percentage of ciliated cells versus flow speed (R(2) = 0.495) and directionality (R(2) = 0.975) between PND 0 and PND 9. Cilia beat frequency (CBF) was higher at PND 0 than at all subsequent time points, but cilia beat waveform was not noticeably different. Tracheal epithelia from a mouse model of primary ciliary dyskinesia (PCD) harboring a Mdnah5 mutation showed that ciliated cell density was unaffected, but no cilia-generated flow was detected. Cilia in mutant airways were either immotile or with slow dyssynchronous beat and abnormal ciliary waveform. Overall, our studies showed that the initiation of cilia-generated flow is directly correlated with an increase in epithelial ciliation, with the measurement of directionality being more sensitive than speed for detecting flow. The higher CBF observed in newborn epithelia suggests unique physiology in the newborn trachea, indicating possible clinical relevance to the pathophysiology of respiratory distress seen in newborn PCD patients.

GP130-STAT3 Regulates Epithelial Cell Migration and Is Required for Repair of the Bronchiolar Epithelium

Following injury, bronchiolar cells undergo rapid squamous metaplasia, followed by proliferation and re-establishment of the complex columnar epithelium that is characteristic of the normal airway. Mechanisms that regulate the repair of bronchiolar epithelium are of considerable relevance for understanding the pathogenesis of both acute and chronic lung diseases associated with airway remodeling. This study was designed to identify the role of the GP130-STAT3 signaling pathway during repair of the bronchiolar epithelium. STAT3 (signal transducer and activator of transcription 3) and GP130 (glycoprotein 130) were each selectively deleted from the pulmonary epithelial cells of transgenic mice in vivo, producing Stat3(Delta/Delta) and Gp130(Delta/Delta) mice, respectively. Airway injury was induced in adult mice by administration of naphthalene, a toxicant of nonciliated respiratory epithelial cells (Clara cells). Nuclear STAT3 staining was induced in bronchiolar epithelial cells following naphthalene-mediated injury in control (Stat3(flox/flox)) mice. Whereas nearly complete repair of the bronchiolar epithelium was observed in control mice within 13 days, restoration of cell shape, cell density, and the pattern of ciliated and nonciliated cells did not occur in the peripheral bronchioles of either Stat3(Delta/Delta) or Gp130(Delta/Delta) mice. Expression of dominant-negative STAT3 inhibited airway epithelial cell migration during repair in vitro; wild-type STAT3 expression activated such migration. In the present study, we show that GP130-STAT3 signaling functions in a cell-autonomous manner to restore cell shape and numbers required for repair of the bronchiolar epithelium following injury.

IL-1β promotes the ciliogenesis of human middle ear epithelial cells: possible linkage with the expression of mucin gene 8

ConclusionsThese findings suggest that IL-1β increases ciliogenesis in NHMEE cells and that MUC8 protein may play a role in this process. ObjectivesThe morphology of the middle ear epithelium changes under various pathologic conditions. We compared the density of ciliated cells and the level of mucin gene 8 (MUC8) mRNA in the middle ear epithelial cells of mucoid otitis media (MOM) patients with those of normal controls. We also investigated the effect of IL-1β on the ciliogenesis and expression of MUC8 mRNA in cultured normal human middle ear epithelial (NHMEE) cells. In addition, we localized the MUC8 protein in cultured NHMEE cells. Material and methodsThe surface morphology of NHMEE cells was examined using scanning electron microscopy. Reverse transcriptase polymerase chain reaction was performed to determine the level of MUC8 mRNA expression. After synthesis of MUC8 polyclonal antibody, we performed immunohistochemical staining. ResultsThe density of ciliated cells was increased in the middle ear epithelium of both MOM patients and IL-1β-treated cultures. Similarly, the expression of MUC8 was increased in both cases. MUC8 antibody was primarily stained on the ciliated cells of NHMEE cells.

Zonation of ciliated cells on the epithelium of the rat trachea.

We have used scanning electron microscopy (SEM) to screen the entire epithelial surface of the cervical trachea of the adult rat. This scrutiny revealed that the density of ciliated cells along this epithelium follows a repetitive pattern: circular strips of high density of ciliated cells alternate with areas of low density of the same cells. Cilia-poor strips of the tracheal epithelium were seen on areas of cartilage rings; here, ciliated cells made up 32% of the total surface of the tracheal lining. Cilia-rich areas filled the epithelial surface at the tracheal ligaments (i.e., the regions located in-between the rings); here, ciliated cells occupied 65% of the tracheal lumen. In the cilia-poor zones, the density of ciliated cells decreased from its periphery into its center, where cilia were virtually absent. No differences in this pattern of the tracheal epithelium were seen between young adult and older rats. We conclude that the respiratory epithelium expresses density zonation of ciliated cells on the trachea of adult rats. We propose that the high concentration of ciliated cells on the regions of epithelium located at the tracheal ligaments suggests that these zones are electively committed in the clearance of the respiratory airway.

Spontaneous lesions in the respiratory epithelium of the Syrian golden hamster as seen by scanning electron microscopy

The respiratory epithelium of 8, 12.5 and 17.5-month-old Syrian golden hamsters was investigated by scanning electron microscopy (SEM) and routine light microscopy (LM) of paraplast sections. In selected cases, SEM-specimens were embedded in Epon after SEM evaluation. The samples were cut in semithin sections and examined by light microscopy. The density of ciliated cells in the respiratory epithelium differs from hamster to hamster. Care must, therefore, be taken when diagnosing simple metaplasia by SEM alone unless a sufficient number of damaged cilia are present. Only 1 animal (8 months old) exhibited squamous metaplasia of the tracheal mucosa. However, surface polymorphism resembling squamous metaplasia was seen in almost every specimen. The polymorphism was caused by either submucosal calcifications or by cystic changes of hypertrophic submucosal glands. In addition, variously formed aggregations of mucus were seen protruding from duct openings of hypertrophic submucosal glands. To avoid false positive or negative diagnosis which can occur when screening is done by SEM alone, light-microscopical examination of sections cut from SEM identified lesions appears necessary.