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At least 307 records · Page 17Linked to original sources
PubMed1990

Dissimilar expression of axonemal anomalies in respiratory cilia and sperm flagella in infertile men.

Infertility by sperm immotility may be a consequence of axonemal defects, and it is sometimes associated with respiratory disease as in the primary ciliary dyskinesia. The purpose of this study was to investigate the respiratory epithelium of 13 infertile patients with flagellar ultrastructural anomalies whether they suffered or not from respiratory disease. Only one patient had severe respiratory disease. The beat frequency of nasal cilia (9 to 13 Hz) was considered normal in 11 of the 13 patients. All the cilia were found abnormal in one patient. In 12 of 13 infertile men (92.3%), significant ultrastructural cilia anomalies were found (greater than 7%) even though the men did not suffer from any respiratory disease. Axonemal anomalies were found at both levels either of the same type (four cases) or only partially similar (two cases) or totally different (six cases). The most frequently abnormal substructure of cilia was the central complex (10 of 12) even in cases exhibiting a different abnormal pattern at the flagellar level. Findings are discussed according to those found in animal mutants. Our results suggest that ciliary and flagellar axonemes should be controlled both by common and by different groups of genes.

Adult↗
PubMed1986

Kartagener's syndrome with motile cilia and immotile spermatozoa: axonemal ultrastructure and function.

A 35-yr-old infertile man with chronic sinobronchial disease and dextrocardia (Kartagener's syndrome) was found to have immotile sperm and motile nasal cilia in vitro. Ciliary beat frequency in vitro was normal, but in vivo nasal mucociliary clearance was markedly prolonged. Quantitative electron microscopy demonstrated a severe reduction in spermatozoal outer and inner dynein arms compared with normal (p less than 0.001) but normal numbers of outer doublets, central microtubules, and radial spokes were seen. In 2 samples of nasal cilia collected 14 months apart, the number of inner dynein arms was significantly reduced from normal (p less than 0.001), but normal numbers of radial spokes and microtubule structures were seen. Ciliary outer dynein arms were slightly reduced in 1 specimen (p less than 0.001) but were normal in the other. It is suggested that the reduction in the number of ciliary inner dynein arms does not affect ciliary motility in vitro but that, under the increased load of mucus in vivo, this defect prevents the cilia from functioning normally. The difference in axonemal ultrastructure between cilia and spermatozoa from the same patient further suggests a separate genetic control of their structural components.

Adult↗
PubMedDate not supplied

Abnormalities of cilia in the middle ear in chronic otitis media.

We studied the fine structure of nasal and middle ear mucosa in 18 patients with chronic otitis media, comparing them with ten age-matched control patients. Electron microscopy revealed no single fundamental defect of cilia in the tissue samples; however, patients with chronic otitis media had a significantly higher incidence of abnormal cilia in the middle ear without correlating abnormalities of nasal cilia. These findings indicated that ciliary anomalies, including deletion of ciliary microtubules, presence of supernumerary tubules, and fusion of cilia, occur as a result of infection or inflammation. Such abnormalities would impair normal mucociliary clearance and exacerbate clinical complications.

Adult↗
PubMed1995

Colonization of the tracheal epithelium of pigs by filamentous bacteria resembling cilia-associated respiratory bacillus.

Warthin Starry staining revealed filamentous bacteria colonizing the tracheal epithelium of 41 of 88 (46.6%) pigs submitted for necropsy at 2 midwestern veterinary diagnostic laboratories. The bacteria were interspersed between and oriented parallel to the cilia. In 4 of 4 colonized pig tracheas, filamentous bacteria were demonstrated by transmission electron microscopy. The bacteria were approximately the same length and diameter as cilia, and in areas of heavy colonization the bacteria outnumbered cilia. The filamentous bacteria were similar in location and morphologic characteristics to cilia-associated respiratory (CAR) bacilli of rats, mice, rabbits, and cattle. Results of immunoperoxidase staining and polymerase chain reaction analysis indicated that the pig CAR bacillus is a different bacterium than the rat CAR bacillus. Rat CAR bacillus causes chronic respiratory disease in rats and mice. The association, if any, between pig CAR bacillus and swine respiratory disease is unknown.

Animals↗
PubMed1981

Serum proteins agglutinate cilia and modify ciliary coordination.

A quantifiable assay is described in which the lateral cilia of the sea mussel Mytilus edulis are used to examine the effects of serum on ciliary function. Human sera and sera from a variety of animals have been found to induce a change in ciliary metachrony. This alteration in activity appears to be brought about by the agglutination of adjacent cilia into blocks, with the effect of increasing the wavelength; the beat frequency remains steady. Parallel studies with the rabbit cilia assay have shown the agglutination of tracheal cilia into clumps by adult bovine serum. The dilution of adult bovine serum lengthens the time before dyskinesia is first observed in both the Mytilus and rabbit assays. Fetal bovine or human cord sera do not cause ciliary dyskinesia or ciliary agglutination. The evidence presented shows that the observed ciliary dyskinesia can be induced by sera from a variety of animals and is not specific to cystic fibrosis; it also suggests that the serum immunoglobulin fraction is responsible for these effects--initial studies implicate IgM.

Adult↗
PubMed2004

Orpk mouse model of polycystic kidney disease reveals essential role of primary cilia in pancreatic tissue organization.

Polycystic kidney disease (PKD) includes a group of disorders that are characterized by the presence of cysts in the kidney and other organs, including the pancreas. Here we show that in orpk mice, a model system for PKD that harbors a mutation in the gene that encodes the polaris protein, pancreatic defects start to occur at the end of gestation, with an initial expansion of the developing pancreatic ducts. Ductal dilation continues rapidly after birth and results in the formation of large, interconnected cysts. Expansion of pancreatic ducts is accompanied by apoptosis of neighboring acinar cells, whereas endocrine cell differentiation and islet formation appears to be unaffected. Polaris has been shown to co-localize with primary cilia, and these structures have been implicated in the formation of renal cysts. In the orpk pancreas, cilia numbers are reduced and cilia length is decreased. Expression of polycystin-2, a protein involved in PKD, is mislocalized in orpk mice. Furthermore, the cellular localization of beta-catenin, a protein involved in cell adhesion and Wnt signaling, is altered. Thus, polaris and primary cilia function are required for the maturation and maintenance of proper tissue organization in the pancreas.

Animals↗
PubMed2004

A genetic screen in zebrafish identifies cilia genes as a principal cause of cystic kidney.

Polycystic kidney disease (PKD) is a common human genetic illness. It is characterized by the formation of multiple kidney cysts that are thought to result from over-proliferation of epithelial cells. Zebrafish larvae can also develop kidney cysts. In an insertional mutagenesis screen in zebrafish, we identified 12 genes that can cause cysts in the glomerular-tubular region when mutated and we cloned 10 of these genes. Two of these genes, vhnf1 (tcf2) and pkd2, are already associated with human cystic kidney diseases. Recently, defects in primary cilia have been linked to PKD. Strikingly, three out of the 10 genes cloned in this screen are homologues of Chlamydomonas genes that encode components of intraflagellar transport (IFT) particles involved in cilia formation. Mutation in a fourth blocks ciliary assembly by an unknown mechanism. These results provide compelling support for the connection between cilia and cystogenesis. Our results also suggest that lesions in genes involved in cilia formation and function are the predominant cause of cystic kidney disease, and that the genes identified here are excellent candidates for novel human PKD genes.

Animals↗
PubMed2006

General and cell-type specific mechanisms target TRPP2/PKD-2 to cilia.

Ciliary localization of the transient receptor potential polycystin 2 channel (TRPP2/PKD-2) is evolutionarily conserved, but how TRPP2 is targeted to cilia is not known. In this study, we characterize the motility and localization of PKD-2, a TRPP2 homolog, in C. elegans sensory neurons. We demonstrate that GFP-tagged PKD-2 moves bidirectionally in the dendritic compartment. Furthermore, we show a requirement for different molecules in regulating the ciliary localization of PKD-2. PKD-2 is directed to moving dendritic particles by the UNC-101/adaptor protein 1 (AP-1) complex. When expressed in non-native neurons, PKD-2 remains in cell bodies and is not observed in dendrites or cilia, indicating that cell-type specific factors are required for directing PKD-2 to the dendrite. PKD-2 stabilization in cilia and cell bodies requires LOV-1, a functional partner and a TRPP1 homolog. In lov-1 mutants, PKD-2 is greatly reduced in cilia and forms abnormal aggregates in neuronal cell bodies. Intraflagellar transport (IFT) is not essential for PKD-2 dendritic motility or access to the cilium, but may regulate PKD-2 ciliary abundance. We propose that both general and cell-type-specific factors govern TRPP2/PKD-2 subcellular distribution by forming at least two steps involving somatodendritic and ciliary sorting decisions.

Adaptor Protein Complex 1↗
PubMed1978

A scanning electron-microscopic study of the local degeneration of cilia during sexual reproduction in Paramecium.

The location and extent of local degeneration of cilia during sexual reproduction of Paramecium was studied using scanning electron microscopy to examine cells undergoing conjugation and autogamy. At some time during the mating reaction, but prior to conjugant pair formation, ciliary degeneration begins at the antero-ventral tip of cells and proceeds posteriorly along the suture. In the anterior part of the cell, degeneration occurs on both sides of the suture, but in the posterior part it is restricted to the right side of the suture. In 5 species of Paramecium examined, degeneration occurred in nearly the same region. No degeneration of cilia is observed in natural autogamy of P. tetraurelia, whereas in chemically induced autogamy of P. caudatum degeneration occurs as in ordinary conjugation. Conjugant pairs never expose any deciliated cell surface except at the postero-ventral tip. The maximum extent of ciliary degeneration is best seen in the chemically induced autogamous cells: 7 kinetics (rows of unit teritories) at the anterior-left, 4 kinetics at the anterior-right, 10 or more kinetics at the posterior-right and the right wall of the vestibule of the mouth. Before complete disappearance of the cilia, many short cilia are observed. This suggests that ciliary degeneration is due to resorption. Degeneration extends more rapidly in cells with stronger mating reactivity. The relations between mating reactivity, ciliary degeneration and nuclear activation are discussed.

Animals↗
PubMed1997

The role of Ca2+ in deflection-induced excitation of motile, mechanoresponsive balancer cilia in the ctenophore statocyst.

Motile, mechanoresponsive cilia (balancers) in ctenophore statocysts, like vertebrate hair cells, are excited or inhibited depending upon the direction in which they are deflected. Balancers, however, may become either excited (beat rapidly) or inhibited (beat slowly) by deflection in the same direction, depending on the sign of ctenophore geotaxis (positive or negative). The beat frequency of many cilia is controlled by concentrations of Ca2+, membrane potential and neural input. How these factors affect deflection-induced ciliary beating in balancers was investigated. Deflection-induced excitation of balancers in whole Mnemiopsis leidyi larvae and dissected adult (Mnemiopsis leidyi, Pleurobrachia pileus) statocysts was reversibly inhibited by the Ca2+ channel inhibitors Co2+, Mg2+, Ni2+, and Mn2+. Deflection-induced excitation in balancers of isolated adult M. leidyi balancer groups was also inhibited by Co2+ or by Ca(2+)-free medium. Isolated balancer group cilia, like balancer cilia of intact ctenophores, exhibited responses to either sign of geotaxis and graded responses to deflection. Isolated balancers that were chemically depolarized in high-[K+], Ca(2+)-free medium were excited by local application of Ca2+ onto the ciliary bases, but not onto the cell bases or the ciliary tips. It is proposed that deflection-induced excitation of balancers is due to influx of Ca2+ through stretch- and voltage-activated channel activity. The sign of geotaxis of whole larvae and dissected adult statocysts was switched by electrical stimulation. Thus, neural input may participate in reversing the directional sensitivity of balancer cells.

Animals↗
PubMed1981

The significance of ultrastructural abnormalities of human cilia.

The electronmicroscopic structure of cilia was studied from the inferior turbinate of the nose in 22 adults, and in 84 biopsies from the bronchial tree of 40 adults. The incidence of compound cilia and abnormal microtubular structures was assessed. There were significant variations in the incidence of abnormalities in different parts of the airways and even within different areas of the same electronmicroscopic section. The focal nature of differences in structure of cilia indicate that abnormalities found in a single biopsy do not necessarily reflect a generalized change in the bronchial tree. Thus, such a finding should not be used as evidence that the abnormalities of cilia are the cause of decrease in mucociliary clearance or that they play a role in the pathogenesis of bronchiectasis and sinusitis.

Adult↗
PubMed1981

Kartagener's syndrome. Preliminary report on cilia structure, function, and upper airway symptoms.

Our study was designed to examine the motility and ultrastructure of cilia from the nose of patients with Kartagener's syndrome. Microphoto-oscillographic recording from single cells showed that the patients had in fact motile cilia, although the number was reduced. Asynchrony within the single cell was a more consistent feature. The first results of blind, quantitative microscopy showed the ultrastructural defects, described earlier, but the overlapping with a normal control group was considerable. Only one of nine patients had no dynein arms and completely immotile cilia; an observation which renders the term "the immotile-cilia syndrome" a misnomer. The ear-nose-throat symptoms were characterized by daily nose-blowings since birth, recurrent sinusitis, and chronic secretory otitis media. On the other hand, the frequency of acute purulent otitis media and of common colds appeared to be normal.

Cilia↗
PubMed1986

Neonatal diagnosis of the immotile cilia syndrome.

The immotile cilia syndrome is an inherited disorder characterized by inappropriate motility of the cilia. The clinical symptoms include recurrent sinopulmonary infections and reduced fertility. In about half of the cases, situs inversus is encountered. The case presented is of a two-day-old boy in whom diagnosis was based on ultrastructural abnormalities. Early diagnosis permitted immediate symptomatic treatment and an absence of infections during a 37-month period of observation. Nasal biopsies performed in six newborns with various degrees of respiratory distress secondary to classic neonatal respiratory problems and in a healthy one-day-old newborn demonstrated the presence of normal ciliary structures at birth. In cases without situs inversus, diagnosis of the immotile cilia syndrome may be difficult. The importance of early diagnosis and management is stressed; the ultrastructural abnormalities are present at birth in newborns with the immotile cilia syndrome.

Biopsy↗
PubMed2007

Identification of ICIS-1, a new protein involved in cilia stability.

Cilia are specialized organelles that exert critical functions in numerous organisms, including that of cell motility, fluid transport and protozoan locomotion. Ciliary architecture and function strictly depend on basal body formation, migration and axoneme elongation. Numerous ultrastructural studies have been undertaken in different species to elucidate the process of ciliogenesis. Recent analyses have led to identification of genes specifically expressed in ciliated organisms, but most proteins involved in ciliogenesis remain uncharacterized. Using human nasal epithelial cells capable of ciliary differentiation in vitro, differential display was carried out to identify new proteins associated with ciliogenesis. We isolated a new gene, ICIS-1 (Involved in CIlia Stability-1), upregulated during mucociliary differentiation. This gene is localized within the TGF-beta1 promoter and is ubiquitously expressed in human tissues. Functional analyses of gene expression inhibition by RNA interference in Paramecium tetraurelia indicated that the ICIS-1 homologue interfered with cilia stability or formation. These findings demonstrate that ICIS-1 is a new protein associated with ciliated cells and potentially related to cilia stability.

Amino Acid Sequence↗
PubMedDate not supplied

Anomalies of centriolar derivatives manifest in spermatic flagella and respiratory cilia of the stallion.

Anomalies of centriolar derivatives were identified in ejaculates and testicular and tracheal biopsies of a sterile stallion, using light, scanning, and transmission electron microscopy. LM revealed that over half the sperm population had only a vestigial or no tail, while the rest had tails of variable length and shape. The vestigial tail was represented by its anlage, which was implanted on the nucleus and differentiated up to capitulum and collum stage. The stunted tail had an axoneme and its derivatives, but was short in all tail segments. Regardless of the tail length or shape, virtually all axonemes were devoid of the central tubular complex ("9 + 0" defect). Abnormal tail segmentation was associated with missing or defective flagellar sheaths and a profusion of extraneous dense fibers, which contributed to the knobby, bulbous, or lobuliform tail configurations. The gradient of flagellar anomalies seems associated with the inability of the distal centriole to implant on the plasmalemma, to produce the axoneme, or maintain its growth, and to induce the normal differentiation of periaxonemal structures. In contrast to sperm, the tracheal epithelium displayed moderate changes, which are manifest in circumscribed rarefaction of cilia, increased incidence of compound cilia, and disturbed orientation of cilia regarding the plane of central tubular complex. The tracheal cilia were free of "9 + 0" defect.

Animals↗
PubMedDate not supplied

Ultrastructural abnormalities in respiratory cilia and sperm tails in a patient with Kartagener's syndrome.

Ultrastructural abnormalities of spermatozoa and respiratory cilia have been reported in a male patient with Kartagener's syndrome and infertility. In this patient both respiratory cilia and sperm tails showed defects in radial spokes and dynein arms. Such defects are heretofore undescribed in the same subject with immotile cilia syndrome. Absence of both inner and outer dynein arms and absence of the inner dynein arms only were detected in spermatozoa and in respiratory tract cilia, respectively. Moreover, total absence of axoneme was seen in several sperm tails from this patient. The possibility that the features described are of genetic origin is discussed.

Adult↗
PubMed1984

Cilia in the human kidney.

Utilizing transmission electron microscopy we have found multiple cilia with a 9 + 2 microtubular pattern (the same type found in the bronchial tree) in the renal tubules of four adults with the nephrotic syndrome. Each patient had a different pathologic diagnosis: amyloidosis, lipoid nephrosis, membranoproliferative glomerulonephritis, and focal segmental glomerulosclerosis. Previously, multiple renal tubular cilia with 9 + 2 architecture had been reported in patients with Burnett's syndrome, systemic lupus erythematosus, and congenital nephrotic syndrome. Additionally, we found multiple cilia in the metanephric tubules of 4 of 4 human fetuses. Pathologists should be aware that cilia with various microtubular patterns occur in human adult kidneys.

Adult↗
PubMed1987

Ultrastructural diagnosis in the immotile cilia syndrome.

This article reports on the experience with 38 biopsies from nasal mucosa, submitted with the question of immotile cilia syndrome. Fixation in glutaraldehyde with MgSO4 is preferable. At least 50 cilia should be scrutinized in the electron microscope, and dynein arms, radial spokes, sheaths, nexin links and orientation should be tabulated. Six cases displayed virtual absence of inner and outer dynein arms. The orientation of these cilia was random. Two of the patients had situs inversus. In biopsies considered not to represent the immotile cilia syndrome, about four inner and seven outer dynein arms were found per cilium.

Adolescent↗