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PubMed1986

Chronic effects of nitrogen dioxide on cilia in hamster bronchioles.

Nitrogen dioxide has been shown to have a deleterious effect on the structure and function of respiratory cilia. This study focuses on both the alterations of cilia morphology, and the ciliated cell response induced by nitrogen dioxide, in order to determine the mechanism(s) leading to ciliary dysfunction. Ciliated cells of the respiratory airways of hamsters, exposed to 30 ppm nitrogen dioxide for 5 months, 7 days/week, 22 hours/day, were examined ultrastructurally using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of thin sections, freeze-fracture replicas, and thin sections of tissues treated with cationized ferritin. SEM and TEM preparations appeared to show a generalized reduction in number and length of cilia. It was common to see basal bodies with no ciliary shaft and many cilia at different stages of growth. It was also apparent that the cilia were most fragile just below the ciliary necklaces. After breakage, the plasma membranes of the remaining ciliary stubs covered the exposed basal bodies. During the early stages of ciliary regeneration, freeze fracture replicas showed the emergence of membrane particles which appeared to correlate with cationized ferritin binding sites. As the cilia increased in length, the particles assembled into a necklace-like arrangement, varying in ring number and particle distribution as compared to the 5 to 7 well organized rings observed in controls. In corresponding thin sections, cationized ferritin appeared bound to sites in the region of the ciliary necklace particles. As the cilia developed further, the cationic ferritin binding at these sites diminished. This data suggests that nitrogen dioxide had an affect on the plasma membranes of ciliated cells. One of the major sites affected by the nitrogen dioxide was the ciliary necklace region. Exposure to nitrogen dioxide appeared to lead to increased ciliary fragility, stunted ciliary growth, and loss of ciliary motility. The rings of ciliary necklace particles exhibited an 8.4 degrees +/- 1.3 degree angle of pitch to a perpendicular through the longitudinal axis of the cilium. The measurable pitch and the identification of ciliary necklace "free ends" proximally and distally lead us to hypothesize that the particle arrangement of the ciliary necklace is that of a single spiral and not separate rings.

Animals↗

PubMed1989

[Lipid composition of mechanosensitive cell cilia and mechanoreceptor organ of bivalve molluscs].

The lipid composition of the mechanoreceptive organ of two marine molluscs in comparison with other molluscan tissues and of isolated cilia of sense organ hair cells in comparison with the gill cilia has been studied. It was shown that the lipid composition of the mechanoreceptive organ differs in a number of features from that of other organs and that the ratios of individual phospholipid classes vary in cilia and intact organs. Ciliary aminophospholipids make up to approximately 89%, whereas choline-containing phospholipids--only 6-8% of the total phospholipid pool. No qualitative phospholipid differences between sense cell cilia and gill cilia were found. However, hair cell cilia contain less phosphatidylethanolamine and choline phospholipids, but more phosphatidylserine and phosphatidylinositol. This suggests that the observed peculiarities of hair cell cilia may play a role in the maintenance of the proper arrangement of hair bundles and the distance between the cilium and stereovilli and/or in the regulation of Ca2(+)-dependent processes.

Animals↗

PubMed1988

Orientation of human respiratory cilia.

Ciliary orientation was studied on the respiratory epithelium of the nasal cavity or the sphenoidal sinus of ten adult nonsmokers without respiratory disease. The ciliary orientation was evaluated from micrographs by measuring the angle between the plane defined by the central tubules and reference line (with a semiautomatic image analyser (IBAS I]. The standard deviation of the angles of cilia population was counted in every field. The standard deviation of the measurements described the ciliary alignment. It varied from 12.1-41.2 degrees. The mean standard deviation was 27.3 +/- 7.4 degrees. 58% of all measured cilia were within +/- 0-20 degrees of the mean and 85% of cilia were within +/- degrees. However, a few cilia or small groups of cilia were found in most fields which differed dramatically from the main orientation. The size of these groups was always less than ten cilia. On the normal respiratory epithelium the standard deviation of ciliary orientation varies between +/- 10-40 degrees (at about 97% probability). For diagnostic conclusions more than 60 cilia should be measured.

Adult↗

PubMed1987

Genesis of cilia and microvilli of rat nasal epithelia during prenatal development. III. Respiratory epithelium surface, including a comparison with the surface of the olfactory epithelium.

During prenatal development the respiratory epithelium surface of the rat's nasal septum underwent the following changes. At intra-uterine day E14 there was a transformation from State I, cells with primary cilia only, to cells which also had microvilli (Stage II). Anterior parts of the nasal septum retained microvilli throughout further development. Posteriorly, centriole multiplication (Stage III) and formation of shafts of secondary cilia (Stage IV) occurred from around E16 and E18 onwards, respectively. From E18 to E20 numbers of cells with cilia increased at an overall rate of about 6 X 10(6) cells/cm2/day. Respiratory cilia and microvilli grew, on average, by about 0.3 micron/day and 0.1 micron/day, respectively. At Stage V, beginning around E19, the cilia became aligned within cells and, at Stage VI, beginning around E21, became synchronised between cells. Respiratory ciliogenesis in the nose is most precocious near the olfactory epithelium. The formation of respiratory cilia starts after that of olfactory cilia. However, unlike olfactory epithelium surfaces those of ciliated respiratory epithelia resembled those of adults around birth.

Animals↗

PubMed1982

[Extraction and investigation of ATPase of Tetrahymena pyriformis cilia].

The ATPase-active proteins were solubilized from T. pyriformis of cilia by treatment of the cilia with the non-ionic detergent Triton X-100. The activity of Triton-solubilized ATPase is stimulated by Ca2+ and is sensitive to EGTA. Electron microscopy has demonstrated that treatment of the cilia with Triton results in demembranation of the cilia. An electrophoretic analysis of protein composition of the cilia before and after the removal of membranes and Triton extraction has shown that dynein and tubulin, the high molecular weight proteins of ciliary axonemes, are not extracted into solution; the Triton extracts were found to contain proteins with molecular weights of 104 000, 94 000, 71 000, 62 000 and 21 000, respectively. The ATPase was purified 10-25-fold by chromatography on DEAE-Sephadex A-50. Na-DS polyacrylamide gel electrophoresis revealed that the highly purified Ca2+-ATPase of cilia consists of two subunits with molecular weights of 93 000 and 85 000. The role of Ca2-ATPase in the mechanism of motility of T. pyriformis of cilia is discussed.

Animals↗

PubMed1984

Ultrastructural study of immotile cilia syndrome.

Recently immotile cilia syndrome has gained the interest of a number of investigators from the aspects of the physiology and pathology of the ciliary movement. This is because microstructural abnormalities of the dynein arms in the cilia of the respiratory mucosal epithelium and in the flagella of sperm tails have been identified in this syndrome. The present study was designed to find a simple clinical method for detecting patients having this syndrome, and was conducted to elucidate the clinical significance and etiology of this syndrome. In order to detect patients with immotile cilia syndrome, 72 patients with one of more conditions such as sinusitis, bronchiectasis, situs inversus and sterility were examined using a ciliary function test and electron microscope observation of the nasal cilia. Seven of the examined patients were diagnosed as having immotile cilia syndrome on the basis of the presence of the characteristic ultrastructural patterns of the nasal cilia, i.e., disorders of the dynein arms. The possibility of positive test results increases greatly as the degree of the complications increases, especially in the case of a combination of chronic inflammation of the respiratory tract with situs inversus and sterility. As the electron microscope findings of this syndrome, Afzelius (1979) has reported defects of the dynein arms, spoke head and central sheath. Beyond these microstructural abnormalities, I have identified abnormal attachment of the dynein arms as a new parameter in the electron microscopic diagnosis of immotile cilia syndrome.

Bronchiectasis↗

PubMed1984

[Sperm flagella and cilia with pathologic motility and ultrastructure].

Motility of sperm flagella as well as of cilia is mechanically based on the principle of 9 + 2-tubules. It functions essentially by coordinated action between microtubules and the adenosine-triphosphatase dynein and was already present at the beginning of the evolution of the eucaryotes. Experimentally induced mutations in algae have resulted in numerous variations of the flagellar 9 + 2-structure. A mutation of this kind is also found in man, as immotile cilia syndrome (ICS) where anomalies in spermatozoa and in cilia (e.g. of the respiratory tract) are observed. Clinical manifestations of the syndrome have long been known (chronic bronchitis, bronchiectasis, sinusitis and male sterility). In addition, half of the patients exhibit situs inversus viscerum, known as Kartagener's syndrome, a subgroup of ICS. Electron microscopy was used to investigate sperm flagella with reduced motility from 9 patients (one with ICS) with primary infertility. Cilia of the respiratory tract from 7 patients (several with ICS) with chronic bronchial problems were analyzed for motility (using video techniques) and ultrastructure. Reduced motility or immotility of spermatozoa and immotile or dyskinetic cilia were always accompanied by ultrastructural anomalies. In spermatozoa, lack of dynein arms, 9 + 0-configuration and extratubuli were most frequently observed. The fibrous sheath was always asymmetrical. Structural ciliary defects resulted in non-parallel arrangements, electron dense matrix substance, extratubuli and lack of radial spokes. In one case, ciliary microtubuli were found in microvilli. In two patients, cilia as well as spermatozoa were analyzed. In the first, immotile spermatozoa without dynein arms and structurally normal cilia were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Abnormal length of respiratory cilia in a pig. An ultrastructural study.

The authors report the first case of abnormal length of respiratory cilia in a domestic animal (18 microns versus normal length about 5 microns). These cilia lie on the carpet of cilia of normal length. The width of some of these cilia is also abnormal, measuring 0.5-0.6 microns. Other cilia have hook-shaped tips that could be responsible for an effective beat. We suggest that the ineffective ciliary beat could also be due to the undulating movements of abnormally long cilia, and stress the need for further morphological and biochemical studies of respiratory cilia in pigs. Respiratory pathology is a very common finding in pigs and is responsible for remarkable economical losses.

Animals↗

PubMed1997

Intravitreal cilia in phakic penetrating eye injury.

BACKGROUND: Intraocular cilia present clinical perplexity due to their radiolucency, the extremely variable ocular response to such cilia, and the inadvisability of using MRI in cases of suspected metallic intraocular foreign bodies (IOFB). METHODS: Two cases of intravitreal cilia associated with phakic penetrating eye injury are described where preoperative CT scan revealed no retained IOFB. RESULTS: B-scan ultrasonography detected intravitreal cilia in one patient and raised this suspicion in the other. One patient presented with endophthalmitis unresponsive to intravitreal antibiotics, the other with culture-negative anterior uveitis. Both underwent vitrectomy and removal of cilia. CONCLUSIONS: Intravitreal cilia should be considered in penetrating eye injuries even in phakic eyes with no radiological evidence of IOFB, especially if associated with endophthalmitis. B-scan ultrasonography may aid detection of intravitreal cilia and thus alter clinical management.

Adolescent↗

PubMed1999

Molecular chaperones in cilia and flagella: implications for protein turnover.

The mechanisms of protein incorporation and turnover in 9+2 ciliary axonemes are not known. Previous reports of an HSP70-related protein, first in Chlamydomonas flagella and then in sea urchin embryonic cilia, suggested a potential role in protein transport or incorporation. The present study further explores this and other chaperones in axonemes from a representative range of organisms. Two-dimensional gel electrophoresis proved identity between the sea urchin ciliary 78 kDa HSP and a constitutive cytoplasmic HSP70 cognate (pI = 5.71). When isolated flagella from mature sea urchin sperm were analyzed, the same total amount and distribution of 78 kDa protein as in cilia were found. Antigens of similar size were detected in ctenophore comb plate, molluscan gill, and rabbit tracheal cilia. Absent from sea urchin sperm flagella, TCP-1alpha was detected in sea urchin embryonic and rabbit tracheal cilia; the latter also contained HSP90, detected by two distinct antibodies. Tracheal cilia were shown to undergo axonemal protein turnover while tracheal cells mainly synthesized ciliary proteins. TCP-1alpha progressively appeared in regenerating embryonic cilia only as their growth slowed, suggesting a regulatory role in incorporation or turnover. These results demonstrate that chaperones are widely distributed ciliary and flagellar components, potentially related to axonemal protein dynamics.

Animals↗

PubMed1975

Fine structure of mammalian renal cilia.

Studies were carried out, using transmission electron microscopy, of the cilia of the nephrons of rat and human kidneys. Cilia were observed in the parietal layer of Bowman's capsule, in the proximal tubule, the distal tubule, including the macula densa, and the collecting duct. They had a number of characteristic features, including the presence of a centriole adjacent to the basal body, long, slender cross-striated rootlets, and a typically organized basal body. The shaft of the cilia differed from the typical 9 + 2 pattern of organization. Near the base of the cilia the pattern was 9 + 0. In the middle portion, one or more of the peripheral doublets had been displaced centrally to give an 8 + 1 or a 7 + 2 pattern, while towards the tip the pattern became more irregular and the doublets were reduced to single microtubules. We have hypothesized that these cilia may be vestigial. They may, if motile, have some minor stirring function, or they may play a sensory role, as has been postulated for similarly structured cilia in other sites.

Animals↗

PubMed2003

Identification of elongation factor-1alpha as a Ca2+/calmodulin-binding protein in Tetrahymena cilia.

Calmodulin (CaM) is known to be a ciliary component. However, the function of CaM in cilia or flagella has not been well understood. Immunoelectron microscopy using anti-CaM antibody showed that CaM was localized on the axonemal microtubules (MTs) and matrix of Tetrahymena cilia. To investigate the signal transduction of Ca(2+)/CaM in cilia, we performed Ca(2+)/CaM-affinity column chromatography in the membrane and matrix fraction. Elongation factor-1alpha (EF-1alpha) was identified as a Ca(2+)/CaM-binding protein in cilia. EF-1alpha is a highly conserved protein and functions in protein translation. In addition, EF-1alpha has been reported to interact with MTs and F-actin in several organisms. Immunoelectron microscopy showed that EF-1alpha was localized on the axonemal MTs. However, in immunoblot analysis, EF-1alpha was mainly extracted in the membrane and matrix fraction from the axonemal MTs by 1% Triton X-100 extraction. These results suggest that interaction between EF-1alpha and axonemal MTs is weak and sensitive to treatment with 1% Triton X-100 and that EF-1alpha mediates between axonemal MTs and CaM in the presence of Ca(2+). Moreover, EF-1alpha was also localized in cilia of Paramecium, suggesting that EF-1alpha functions as a target protein of Ca(2+)/CaM in ciliate cilia.

Animals↗

PubMed2006

Three types of cilia including a novel 9+4 axoneme on the notochordal plate of the rabbit embryo.

Motile monocilia play a pivotal role in left-right axis determination in mouse and zebrafish embryos. Cilia with 9+0 axonemes localize to the distal indentation of the mouse egg cylinder ("node"), while Kupffer's vesicle cilia in zebrafish show 9+2 arrangements. Here we studied cilia in a prototype mammalian embryo, the rabbit, which develops via a flat blastodisc. Transcription of ciliary marker genes Foxj1, Rfx3, lrd, polaris, and Kif3a initiated in Hensen's node and persisted in the nascent notochord. Cilia emerged on cells leaving Hensen's node anteriorly to form the notochordal plate. Cilia lengthened to about 5 mum and polarized from an initially central position to the posterior pole of cells. Electron-microscopic analysis revealed 9+0 and 9+2 cilia and a novel 9+4 axoneme intermingled in a salt-and-pepper-like fashion. Our data suggest that despite a highly conserved ciliogenic program, which initiates in the organizer, axonemal structures may vary widely within the vertebrates.

Animals↗

PubMed1992

Lectins bind differentially to cilia and microvilli of major and minor cell populations in olfactory and nasal respiratory epithelia.

Binding of colloidal gold-conjugated lectins was studied in cilia and microvilli of rat olfactory and respiratory epithelia. This was done in sections of rapidly frozen, freeze-substituted specimens embedded in Lowicryl K11M or, for wheat germ agglutinin (WGA) alone, in deep-etched replicas. Olfactory dendritic endings and cilia labeled with WGA and faintly with soybean agglutinin (SBA); olfactory supporting cell microvilli bound only Dolichos biflorus agglutinin (DBA). Microvilli of an infrequent cell bound peanut agglutinin (PNA), SBA, and WGA. These microvilli labeled more strongly with the last two lectins than the olfactory cilia. Respiratory cilia bound WGA and, somewhat more weakly, PNA; microvilli of ciliated respiratory cells bound all four lectins. Visualization of specific labeling improved after preincubation of sections with neuraminidase, except for DBA where lectin binding was abolished. PNA labeling was seen only after neuraminidase preincubation. The densities of membrane surface particles that labeled with WGA corresponded with those of fracture plane particles in a quantitative freeze-fracture, deep-etch analysis. Therefore, a considerable fraction of the WGA-bound particles could reflect transmembrane proteins in olfactory dendritic endings and cilia and in respiratory cilia. The possible nature of these particles is discussed.

Acrylic Resins↗

PubMed1988

Effects of theophylline on expression of the long cilia phenotype in sand dollar blastulae.

Previously, increases in ciliary length have only been obtained through genetic mutation in Chlamydomonas or by incubation of swimming echinoderm blastulae in trypsin or elastase. We have found that the phenotypic switch from short to long cilia on sand dollar blastulae can also be effected by incubation in theophylline. Cilia detached from control blastulae have a mean length of 21 +/- 7 microns with 10% of the cilia being greater than 30 microns. Upon incubation in 10 mM theophylline additional long cilia appeared after 10 hours and by 24-32 hours 1/2-3/4 of the embryo was covered with long cilia. The percentage of long cilia increased to 65% with a mean length of 40.0 +/- 17.6 microns. Incubation in other methylxanthines, such as aminophylline, caffeine, or isobutylmethylxanthine, inhibited development but had no effect on ciliary length distribution. Dibutyryl cAMP, 8-bromoadenosine, and calcium ionophore also had no effect on ciliary length. Cyclic AMP levels were measured and showed only slight differences among controls and embryos incubated in trypsin, caffeine, or theophylline. These data suggest that theophylline may be altering ciliary length control through some mechanism other than elevations in cAMP.

Animals↗

PubMed1976

Some changes in the properties of dynein ATPase in situ and after extraction following heat treatment of cilia.

Glycerol-extracted cilia from Tetrahymena pyriformis were demembranated by treatment with Triton X-100 and then heated for up to 30 min at temperatures between 34-38 degrees C. Heat treatment caused an uncoupling of the ATPase from motility as indicated by an increase in ATPase activity and a loss of pellet height response. After heat treatment, the ATPase activity of the dynein in situ differed from that in unheated cilia as shown by an increased sensitivity to a lower temperature of assay (0 degrees C) and by a loss of the activation normally observed upon reaction with N-ethylmaleimide or p-phenylenedimaleimide. Upon extraction of the heat-treated cilia by Tris-EDTA, there was a large loss in ATPase activity so that the heat-treated cilia yielded a crude dynein fraction with a lower specific activity compared with that obtained from unheated controls. The difference was not due to a change in the amount of protein recovered or in the amount of ATPase activity which remained unextracted. Resolution of the crude dynein by sucrose density sedimentation indicated that activity was lost from both the 14S and 30S peaks but more so from the latter than from the former. Thus dynein in situ in cilia in which the ATPase has been uncoupled from motility by gentle heat treatment differs in several important respects from dynein inside unheated cilia.

Adenosine Triphosphatases↗

PubMed2004

Cilia-related diseases.

There are at least eight categories of cilia in the human body and malfunctioning of any one or several of them will have different consequences for the patient. A genetic error of the respiratory cilia (9 + 2) is the cause of the airways disease named immotile-cilia syndrome (or PCD), whereas defective ependymal cilia (9 + 2) carries an increased risk of hydrocephalus. When the so-called nodal cilia (9 + 0) of the early embryo are malfunctioning, there is a random determination of asymmetry of the heart and visceral organs ('a 50% risk of situs inversus'). Some genes are responsible for the synthesis, transport, and assembly of the cilia, and mutations in these genes may lead to progressive degeneration of ciliary structures, such as the connecting cilium (9 + 0) of the photoreceptor cells-this is the cause of retinitis pigmentosa. Ciliary malfunctions due to genetic errors tend to be systemic and life-long, whereas acquired diseases are local and may be temporary only.

Cilia↗

PubMed1975

The sensory cilium of retinal rods is analogous to the transitional zone of motile cilia.

The connecting cilium of rat retinal rods was studied by freeze-fracture and thin-sectioning techniques. Transverse strands of intramembranous particles could be observed on fracture face B on the ciliary plasma membrane. The strands were essentially similar to those found at the transitional zone of motile cilia ("ciliary necklace"). The larger number of intramembranous particles obscured the pattern on fracture face A of the membrane. On longitudinal sections of the cilia, beads showing a periodicity similar to the necklace strands were observed. Each bead consisted of two structures apposed to both sides of the plasma membrane. Transverse sections of the cilia revealed radial Y-shaped structures that connected each ciliary doublet with the plasma membrane. Axial tubules, central sheath, radial spokes and dynein arms were missing in the connecting cilium. Comparing the fine structure of the retinal cilia with that of motile cilia it becomes evident that the connecting cilium is analogous in structure with the transitional zone of motile cilia. The present observations suggest that periodic membrane beads along the plasma membrane on thin sections correspond to strands of necklace particles as observed on freeze-fractured membranes. The arrangement of the particles in transverse strands is probably ensured by the radial connecting structures.

Animals↗