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PubMed1986

Beat frequency of cilia from sites of purulent infection.

Mucociliary clearance depends on the interaction between cilia and mucus; it is delayed in the presence of purulent secretions. Nasal mucociliary clearance was examined by the saccharin method and nasal ciliary beat frequency by a photometric technique. Four groups were studied: normal controls, patients with bronchiectasis without nasal symptoms, patients with chronic mucopurulent sinusitis alone, and patients with chronic mucopurulent sinusitis and bronchiectasis. Nasal mucociliary clearance was prolonged in infected patients. Cilia obtained from the site of purulent secretions were found to beat more slowly in vitro (mucopurulent sinusitis 12.1 Hz, mucopurulent sinusitis and bronchiectasis 11.6 Hz), than those obtained from normal controls (14.3 Hz) and from patients with bronchiectasis alone (13.6 Hz). The cause of the ciliary slowing seemed most likely to be the release of host factors during the inflammatory response, rather than the particular organism isolated. Ciliary slowing may contribute to the observed delay of mucociliary clearance in conditions in which purulent secretions are present.

Adolescent↗
PubMed1984

Ultrastructural, cellular, and clinical features of the immotile-cilia syndrome.

The immotile-cilia syndrome is an autosomal recessive disease of the microtubules of ciliated cells and spermatozoa, and possibly also of neutrophil leukocytes; it affects approximately 1 in 20,000 people. A variety of aberrations in the axonemal microtubular apparatus has been observed. The most common is deficiency of dynein-arms, which leads to immotility or erratic movement of spermatozoa and respiratory tract cilia. The result is male sterility, and chronic or recurrent respiratory tract infections and bronchiectasis due to absence of mucociliary clearance. In addition, 50% of the persons have situs inversus and hence Kartagener's syndrome.

Chronic Disease↗
PubMed1994

A morphological study of the primary cilia in the rat pancreatic ductal system: ultrastructural features and variability.

Primary cilia in the pancreas of the rat were studied by transmission electron microscopy. Their presence is very common, and each ductal cell seems to be provided with a single cilium. The basal body showed anchoring apparatus such as transitional fibers and basal feet. The shaft can show a number of different patterns according to the level of the sections. Proceeding towards the tip, the microtubules decrease in number, although not always in the same way. Near the tip, it is possible to detect patterns, with only 1 microtubule. Three kinds of tips are described. The function of the cilia is discussed.

Animals↗
PubMed1984

The dyskinetic cilia syndrome in childhood. Modifications of ultrastructural patterns.

The syndrome of cilia dyskinesia is known as a heterogenous ciliary dysfunction caused by morphological defects of the dynein arms, the nexin links, the radial spokes and by the transposition of microtubules. Supernumerary tubules have been regarded as acquired morphological defects on the background of other bronchopathies. The report of a 9-year-old girl with the clinical signs of ciliary dyskinesis is considered to be an attribution to the clinical and pathological features of this syndrome. The girl's history of chronic bronchopulmonary infections and nasal polyposis resistant to therapy made her suspected to be ill of Kartagener's syndrome. The results of ultrastructural investigations of the mucosa from ciliated epithelium revealed a ciliary structural defect in the bronchi as well as in the nose and the sinuses with supernumerary microtubular doublets and singles, a decentration of the central tubules and shortened dynein arms. The regularity of the electron optical abnormalities implicates a systemic disorder of ciliated epithelium, which is to be summarized to the syndrome of cilia dyskinesis.

Bronchi↗
PubMed1994

Smoke and viral infection cause cilia loss detectable by bronchoalveolar lavage cytology and dynein ELISA.

The purpose of this study was to quantitate cilia loss following airway epithelial cell injury. Two models of airway injury were used: (1) Ex vivo acute cigarette smoke exposure model: Bovine lungs, obtained directly after slaughter, were ventilated with air or cigarette smoke for 5 min followed immediately by bronchoalveolar lavage (BAL). The bronchi were examined histologically and bronchial and alveolar fractions of BAL fluid were examined for cell counts, cell differentials, and cilia dynein concentrations using a specific 13S dynein ELISA. Smoke exposure resulted in a marked loss of ciliated cells from the bronchial luminal surface (2,364 +/- 351 versus 11,090 +/- 542 ciliated cells/mm2; p = 0.0001), a comparable increase in ciliated cells in the bronchial BAL fraction (0.90 x 10(6) cells/mm3 versus 0.15 x 10(6) cells/mm3; p = 0.0003) and a significant increase in bronchial fluid dynein concentrations (24.5 +/- 6.0 micrograms/ml versus 8.9 +/- 2.2 micrograms/ml; p = 0.03) compared with that in air-exposed lungs. The dynein concentrations strongly correlated with the absolute number of ciliated cells recovered in the bronchial lavage (r = 0.80; p < 0.0001). (2) In vivo viral infection model: Healthy cattle underwent bronchoscopy 3 days before and 7 days after inoculation with bovine respiratory syncytial virus (BRSV). BAL fluid was examined as in the first model. Following BRSV inoculation, airway exfoliation of ciliated cells and squamous metaplasia were observed histologically, bronchial ciliated cell counts doubled (0.011 +/- 0.003 x 10(6) cells/mm3 versus 0.026 +/- 0.006 x 10(6) cells/mm3; p = 0.002) and bronchial dynein concentrations increased threefold (2.2 +/- 1.0 micrograms/ml versus 7.2 +/- 1.9 micrograms/ml; p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Microtubular protofilaments and subunits of the outer dynein arm in cilia from dogs with primary ciliary dyskinesia.

Using a procedure of membrane solubilization followed by tannic acid fixation-staining, we found abnormally constructed central and B microtubules in cilia from dogs with primary ciliary dyskinesia. We also found that a ciliary abnormality commonly associated with primary ciliary dyskinesia, "shortened outer dynein arms," actually represents the absence of a specific set of the 3 peripheral subunits that make up the outer dynein arms. We believe that this is the first time that these have been reported. Because the proximal subunits of the outer dynein arm are present and attached to the A microtubule, we argue that in these patients there is no structural abnormality of the A microtubule or the A-tubule attachment sites for outer and inner arms and radial spokes. Also, because a majority of cilia in these patients were motile, we believe that the data from this study support the concept that the outer dynein arms are not required for some motion but probably required for normal motility; however, the central microtubules, central microtubular complex, and probably the B tubules are essential for motility.

Adenosine Triphosphatases↗
PubMed1986

Middle ear cilia activity as a determinant of tympanostomy tube placement.

Three hundred and twenty-six patients with diagnoses of serous otitis media--or mucoid otitis media--were reviewed for the presence or absence of middle ear cilia activity. This study strongly suggests that if active cilia can be observed, ventilating tubes are not needed. This easily observed activity in the anterior-inferior quadrant offers the otolaryngologist an accurate tool for determination of the future health of the middle ear.

Child↗
PubMed1996

Morphological evidence of a filamentous cilia-associated respiratory (CAR) bacillus in goats.

A filamentous cilia-associated respiratory (CAR) bacillus was discovered in 12 3-4 month-old goats experimentally infected with two different strains of mycoplasmas belonging to the Mycoplasma mycoides type. The CAR bacilli were always arranged parallel to the cilia, and the morphology of these bacilli is very similar to that of other bacilli described previously in other species from various parts of the world.

Animals↗
PubMed2003

The left-right determinant Inversin is a component of node monocilia and other 9+0 cilia.

Inversin (Inv), a protein that contains ankyrin repeats, plays a key role in left-right determination during mammalian embryonic development, but its precise function remains unknown. Transgenic mice expressing an Inv and green fluorescent protein (GFP) fusion construct (Inv::GFP) were established to facilitate characterization of the subcellular localization of Inv. The Inv::GFP transgene rescued the laterality defects and polycystic kidney disease of Inv/Inv mice, indicating that the fusion protein is functional. In transgenic embryos, Inv::GFP protein was detected in the node monocilia. The fusion protein was also present in other 9+0 monocilia, including those of kidney epithelial cells and the pituitary gland, but it was not localized to 9+2 cilia. The N-terminal region of Inv (InvDeltaC) including the ankyrin repeats also localized to the node cilia and rescued the left-right defects of Inv/Inv mutants. Although no obvious abnormalities were detected in the node monocilia of Inv/Inv embryos, the laterality defects of such embryos were corrected by an artificial leftward flow of fluid in the node, suggesting that nodal flow is impaired by the Inv mutation. These results suggest that the Inv protein contributes to left-right determination as a component of monocilia in the node and is essential for the generation of normal nodal flow.

Animals↗
PubMed1995

Transcriptional control of tektin A mRNA correlates with cilia development and length determination during sea urchin embryogenesis.

Previous studies have shown that tektin A, one of three integral filamentous protein components of outer doublet microtubules, is synthesized in sea urchins in an amount correlating to the length of embryonic cilia initially assembled or experimentally regenerated. To investigate further the molecular mechanism for the regulation of tektin synthesis, tektin cDNA clones were used to assess mRNA levels during ciliogenesis, zinc-induced animalization, deciliation-induced regeneration and theophylline-induced elongation. Possibly involved in centriole replication, low, near-constant levels of mRNA for all three tektins are present in the unfertilized egg and during cleavage stages. Preceded by new synthesis of tektin B and C mRNAs, tektin A mRNA is up-regulated during ciliogenesis, but only tektin A mRNA levels correlate directly with ciliary length in animalized embryos; the others augment larger, non-limiting pools of tektins B and C. Tektin mRNAs decrease to steady-state levels after ciliogenesis, but are up-regulated again when the embryos are deciliated, correlating with the length of cilia to be deployed. In a species where a 3-fold ciliary length increase can be induced by theophylline treatment of zinc-arrested embryos, the mRNAs accumulate to proportionately higher levels during arrest but are not translated until induction, whereupon they decrease inversely with ciliary elongation. This suggests transcriptional control with respect to mRNA amounts but post-transcriptional control with respect to the expression of this phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Tubulin in sea urchin embryonic cilia: characterization of the membrane-periaxonemal matrix.

When the membranes of isolated embryonic cilia from three species of sea urchin are detergent-solubilized, the major proteins found are two equi-molar polypeptides comigrating with tubulin subunits. Cross-reactivity with a variety of tubulin antibodies confirms their identity. Calmodulin and other calcium-binding proteins are prominent minor constituents of the extract. Removal of the solubilizing detergent by adsorption to polystyrene beads, followed by a freeze-thaw cycle, produces membrane leaflets and vesicles of uniform bouyant density. Such reconstituted membranes incorporate most of the tubulin and minor proteins but not calmodulin. Equivalent cross-reactivity with antibodies to acetylated or detyrosinated alpha-tubulin indicates that the tubulin derived from the membrane-periaxonemal matrix and axoneme are indistinguishable from each other in terms of these posttranslational modifications but are distinct from the mainly unmodified tubulin of the embryonic cytoplasm. Pulse labeling with [3H]palmitate does not label either tubulin subunit but acylation does occur on a 190 x 10(3) Mr membrane protein. Its specific activity is essentially the same whether label is applied to embryos with existing or regenerating cilia, suggesting rapid ciliary membrane protein exchange or physical turnover. Using pulse-chase labeling with [3H]leucine during steady-state ciliary growth or induced regeneration in both normal and zinc-animalized embryos, the specific activity of the membrane-periaxonemal matrix-derived tubulin is initially higher than that of the axoneme but the degree of labeling equalizes in successive regenerations, consistent with derivation from a common pool. Many heavily labeled axonemal architectural proteins, such as tektin-A, are not reflected in the membrane-periaxonemal matrix fraction, suggesting that this fraction is not simply a pool of unassembled axonemal precursors.

Animals↗
PubMed1992

Tubulin in sea urchin embryonic cilia: post-translational modifications during regeneration.

Tubulin is the major protein found in the membrane/periaxonemal matrix fraction of mature sea urchin embryonic cilia but its distribution and possible function during ciliary assembly are unknown. Hypertonic salt may be used to deciliate the embryos, allowing synchronous regrowth of cilia and subsequent deciliation of the regenerating embryos at various times. During the earliest stages of regeneration, the amounts of tubulin in the axoneme and membrane/matrix fractions are nearly equal, but the proportion of tubulin in the axoneme fraction increases coincident with the quasi-linear growth phase while the membrane/matrix tubulin remains constant. Antibodies to tyrosinated and detyrosinated alpha-tubulin show that both the membrane/matrix and axonemal tubulin fractions are primarily unmodified (i.e. tyrosinated) at the earliest stages of regeneration but are progressively and equally detyrosinated coincident with regeneration, approaching a final level of 50% C-terminal Glu. A monoclonal antibody to acetylated alpha-tubulin reveals that both tubulin fractions are equally and maximally acetylated at relatively early stages of regeneration. In contrast, three-times-repolymerized tubulin from either unfertilized eggs or midgastrula embryos is primarily tyrosinated (greater than 97%) and not detectably acetylated. These data suggest that membrane/matrix tubulin is a precursor to axonemal tubulin and that acetylation and detyrosination may be involved in partitioning tubulin among cytoplasmic, ciliary membrane/matrix, and 9 + 2 compartments.

Acetylation↗
PubMed2002

Ca(2+)-binding proteins of cilia and infraciliary lattice of Paramecium tetraurelia: their phosphorylation by purified endogenous Ca(2+)-dependent protein kinases.

We purified two small, acidic calcium-binding proteins (Paramecium Ca(2+)-binding proteins, PCBP-25alpha and PCBP-25beta) from Paramecium tetraurelia by Ca(2+)-dependent chromatography on phenyl-Sepharose and by anion-exchange chromatography. The proteins were immunologically distinct. Monoclonal antibodies against PCBP-25beta did not react with PCBP-25alpha, and antibodies against centrin from Chlamydomonas reacted with PCBP-25alpha but not with PCBP-25beta. Like the centrins described previously, both PCBPs were associated with the infraciliary lattice (ICL), a fibrillar cytoskeletal element in Paramecium. Both were also present in isolated cilia, from which they could be released (with dynein) by a high-salt wash, and both PCBPs cosedimented with dynein in a sucrose gradient. PCBP-25beta was especially prominent in cilia and in the deciliation supernatant, a soluble fraction released during the process of deciliation. The results of immunoreactivity and localization experiments suggest that PCBP-25alpha is a Paramecium centrin and that PCBP-25beta is a distinct Ca(2+)-binding protein that confers Ca(2+) sensitivity on some component of the cilium, ciliary basal body or ICL. We characterized these proteins and Paramecium calmodulin as substrates for two Ca(2+)-dependent protein kinases purified from Paramecium. PCBP-25alpha and calmodulin were in vitro substrates for one of the two Ca(2+)-dependent protein kinases (CaPK-2), but only PCBP-25alpha was phosphorylated by CaPK-1. These results raise the possibility that the biological activities of PCBP-25alpha and calmodulin are regulated by phosphorylation.

Animals↗
PubMed1984

Ca2+-dependent regulation of beat frequency of cilia in Paramecium.

Triton-extracted models of Paramecium cells prepared in the presence of Mg2+ and EGTA showed Ca2+ sensitivity not only in the direction of beat but also in the beat frequency of cilia. The beat frequency increased over a range of concentration of Ca2+ from 2 X 10(-7) to 4 X 10(-7) M, in which the model swam forwards. The frequency increased also above 10(-6)M-Ca2+, in which the model swam backwards. The increase in frequency was inhibited by calmodulin antagonists. Intracellular injection of a Ca2+ buffer giving a free Ca2+ concentration of 2 X 10(-7) to 5 X 10(-7) M in intact cells induced an increase in the beat frequency. Therefore, it is very likely that the beat frequency of cilia is regulated by the intracellular concentration of Ca2+.

Adenosine Triphosphate↗
PubMed1987

Evidence that tubulin forms an integral membrane skeleton in molluscan gill cilia.

Controlled extraction of intact gill tissue, isolated cilia or reconstituted membrane vesicles with Nonidet P-40 at greater than 4 times the critical micelle concentration, or with octyl glucoside at the critical micelle concentration, delipidates the membrane, leaving a membrane remnant or skeleton of membrane tubulin and associated proteins. This skeleton consists of a disordered reticular protein network in reconstituted membrane vesicles and a similar but more compact sleeve in cilia of extracted tissue. The membrane skeleton is closely apposed to the axoneme and is attached to the outer doublets by fine radial bridges having a 20-24 nm longitudinal periodicity, supporting earlier observations made utilizing a lipophilic cross-linking agent. Higher concentrations of detergent solubilize the membrane tubulin-protein complex, producing 5-10 nm particulate material of low sedimentation coefficient. Dilution of an octyl glucoside solution to below the critical micelle concentration results in disappearance of the particles and reformation of the membrane, indicating that the particles are protein-detergent micelles and not denatured protein. Freeze-fracture electron microscopy reveals no comparable-sized natural particles in the ciliary membrane proper. The reticular material of the membrane skeleton contains tubulin, demonstrated on Lowicryl K4M thin sections by a rabbit polyclonal antibody to sea-urchin egg cytoplasmic tubulin, using gold-labelled secondary antibody. Minimal cross-reactivity is detected prior to Triton-delipidation, suggesting that most membrane tubulin antigenic sites are buried within the bilayer and that the tubulin is not simply adsorbed to the lipid bilayer.

Animals↗
PubMed2001

ATP-regenerating system in the cilia of Paramecium caudatum.

The energy supply for eukaryotic ciliary and flagellar movement is thought to be maintained by ATP-regenerating enzymes such as adenylate kinase, creatine kinase and arginine kinase. In this study, the energy-supplying system for the ciliary movement of Paramecium caudatum was examined. Arginine kinase and adenylate kinase activities were detected in the cilia. To demonstrate that phosphoarginine satisfactorily supplies high-energy phosphate compounds into the narrow ciliary space, we prepared an intact ciliated cortical sheet from live Paramecium caudatum. These cortical sheets, with an intact ciliary membrane, produced a half-closed system in which each cilium was covered with a ciliary membrane with an opening to the cell body. Ciliary beating on the intact cortical sheets was induced by perfusing not only ATP but also ADP. Addition of phosphoarginine (0.2 mmol l(-1)) increased the beat frequency. A further increase in beat frequency was observed in 0.4 mmol l(-1) phosphoarginine, and this was enhanced when the cilia were reactivated with relatively low concentrations of ATP. We have demonstrated that phosphoarginine supplies energy as a 'phosphagen' for ciliary beating in Paramecium caudatum, suggesting that phosphoarginine functions not only as a reservoir of energy but also as a transporter of energy in these continuously energy-consuming circumstances. http://www.biologists.com/JEB/movies/jeb3123.html

Adenosine Triphosphate↗
PubMed2005

Caenorhabditis elegans as a model to study renal development and disease: sexy cilia.

The nematode Caenorhabditis elegans has no kidney per se, yet "the worm" has proved to be an excellent model to study renal-related issues, including tubulogenesis of the excretory canal, membrane transport and ion channel function, and human genetic diseases including autosomal dominant polycystic kidney disease (ADPKD). The goal of this review is to explain how C. elegans has provided insight into cilia development, cilia function, and human cystic kidney diseases.

Animals↗
PubMed2005

NIMA-related kinases defective in murine models of polycystic kidney diseases localize to primary cilia and centrosomes.

A key feature of the polycystic kidney diseases is aberrant cell proliferation, a consequence of dysfunctional ciliary signaling. The NIMA-related kinases (Nek) Nek1 and Nek8 carry the causal mutations of two of the eight established mouse models of polycystic kidneys. Nek proteins have roles in cell cycle and may contribute to coordinate regulation of cilia and cell-cycle progression. Herein is reported that in a mouse kidney epithelial cell line, mNek1 localizes to centrosomes in interphase and remains associated with the mitotic spindle pole during mitosis. In contrast, mNek8 localizes to the proximal region of the primary cilium and is not observed in dividing cells. Knockdown of mNek8 by siRNA does not affect ciliary assembly. Taken together with the phenotypes of the mutant mice, these data suggest that mNek1 and mNek8 provide links between cilia, centrosomes, and cell-cycle regulation.

Animals↗