scholarly journals Superresolution microscopy reveals photoreceptor-specific subciliary location and function of Cep290

2020 ◽  
Author(s):  
Valencia L. Potter ◽  
Abigail R. Moye ◽  
Michael A. Robichaux ◽  
Theodore G. Wensel
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Fluorescence Microscopy ◽  
Mouse Models ◽  
Primary Cilia ◽  
Cultured Cells ◽  
Precise Location ◽  
Superresolution Microscopy ◽  
Functional Roles ◽  
And Function

AbstractMutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multi-organ syndromic ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used superresolution fluorescence microscopy and electron microscopy (TEM) to localize CEP290 in the CC and in primary cilia of cultured cells with sub-diffraction resolution, and to determine effects of CEP290 deficiency. Radially, CEP290 co-localizes with the microtubule doublets and extends beyond them. Longitudinally, it is distributed throughout the length of the CC but is strictly confined to the very base of primary cilia in hRPE-1 cells. We found Y-shaped links, the ciliary sub-structures between microtubules and membrane, at the base of the transition zone in primary cilia of epithelial cells and throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. They did not lead to loss of the Y-shaped links but caused changes in their structures. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.

scholarly journals Canalicular domain structure and function in matrix-free hepatic spheroids

2020 ◽  
Vol 8 (1) ◽  
pp. 485-496 ◽  
Author(s):  
Vikas Raj Sharma ◽  
Ananya Shrivastava ◽  
Benoit Gallet ◽  
Elizaveta Karepina ◽  
Peggy Charbonnier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fluorescence Microscopy ◽  
Light Sheet ◽  
Structure And Function ◽  
Bile Canaliculi ◽  
Combined Use ◽  
3D Electron Microscopy ◽  
And Function ◽  
Matrix Free ◽  
Light Sheet Fluorescence Microscopy

The combined use of light sheet fluorescence microscopy and 3D electron microscopy enables to reveal the fine details of bile canaliculi structure and function in matrix-free hepatic spheroids.

scholarly journals Deciliation Is Associated with Dramatic Remodeling of Epithelial Cell Junctions and Surface Domains

2009 ◽  
Vol 20 (1) ◽  
pp. 102-113 ◽  
Author(s):  
Christian E. Overgaard ◽  
Kaitlin M. Sanzone ◽  
Krystle S. Spiczka ◽  
David R. Sheff ◽  
Alexander Sandra ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Primary Cilia ◽  
Mdck Cells ◽  
Cell Junctions ◽  
Apical Trafficking ◽  
Epithelial Remodeling ◽  
Surface Domains ◽  
And Function ◽  
Mediated Reduction ◽  
Junction Proteins

Stress-induced shedding of motile cilia (autotomy) has been documented in diverse organisms and likely represents a conserved cellular reaction. However, little is known about whether primary cilia are shed from mammalian epithelial cells and what impact deciliation has on polarized cellular organization. We show that several chemically distinct agents trigger autotomy in epithelial cells. Surprisingly, deciliation is associated with a significant, but reversible increase in transepithelial resistance. This reflects substantial reductions in tight junction proteins associated with “leaky” nephron segments (e.g., claudin-2). At the same time, apical trafficking of gp80/clusterin and gp114/CEACAM becomes randomized, basal-lateral delivery of Na,K-ATPase is reduced, and expression of the nonciliary apical protein gp135/podocalyxin is greatly decreased. However, ciliogenesis-impaired MDCK cells do not undergo continual junction remodeling, and mature cilia are not required for autotomy-associated remodeling events. Deciliation and epithelial remodeling may be mechanistically linked processes, because RNAi-mediated reduction of Exocyst subunit Sec6 inhibits ciliary shedding and specifically blocks deciliation-associated down-regulation of claudin-2 and gp135. We propose that ciliary autotomy represents a signaling pathway that impacts the organization and function of polarized epithelial cells.

scholarly journals Cby1 promotes Ahi1 recruitment to a ring-shaped domain at the centriole–cilium interface and facilitates proper cilium formation and function

2014 ◽  
Vol 25 (19) ◽  
pp. 2919-2933 ◽  
Author(s):  
Yin Loon Lee ◽  
Joshua Santé ◽  
Colin J. Comerci ◽  
Benjamin Cyge ◽  
Luis F. Menezes ◽  
...  
Keyword(s):  
Primary Cilia ◽  
Three Dimensional ◽  
Joubert Syndrome ◽  
Cystic Kidneys ◽  
Superresolution Microscopy ◽  
Close Proximity ◽  
And Function ◽  
Canonical Wnt ◽  
Syndrome Protein ◽  
Shaped Domain

Defects in centrosome and cilium function are associated with phenotypically related syndromes called ciliopathies. Cby1, the mammalian orthologue of the Drosophila Chibby protein, localizes to mature centrioles, is important for ciliogenesis in multiciliated airway epithelia in mice, and antagonizes canonical Wnt signaling via direct regulation of β-catenin. We report that deletion of the mouse Cby1 gene results in cystic kidneys, a phenotype common to ciliopathies, and that Cby1 facilitates the formation of primary cilia and ciliary recruitment of the Joubert syndrome protein Arl13b. Localization of Cby1 to the distal end of mature centrioles depends on the centriole protein Ofd1. Superresolution microscopy using both three-dimensional SIM and STED reveals that Cby1 localizes to an ∼250-nm ring at the distal end of the mature centriole, in close proximity to Ofd1 and Ahi1, a component of the transition zone between centriole and cilium. The amount of centriole-localized Ahi1, but not Ofd1, is reduced in Cby1−/− cells. This suggests that Cby1 is required for efficient recruitment of Ahi1, providing a possible molecular mechanism for the ciliogenesis defect in Cby1−/− cells.

Growth and characterization of porcine urinary bladder epithelial cells in vitro

1994 ◽  
Vol 266 (2) ◽  
pp. F298-F308 ◽  
Author(s):  
C. Guhe ◽  
W. Follmann
Keyword(s):  
Epithelial Cells ◽  
Urinary Bladder ◽  
Cultured Cells ◽  
Apical Cell ◽  
Membrane Integrity ◽  
Membrane Vesicles ◽  
Lactate Dehydrogenase Activity ◽  
And Function

Dividing long-term monolayer cultures of porcine urinary bladder epithelial cells were obtained by a combined mechanical and enzymatic isolation method. The serum-free cultured cells were investigated morphologically and characterized according to their growth characteristics and enzymatic functions. Investigations over a period up to 12 wk demonstrated that the cells regain their in vivo polarization with apically situated membrane vesicles and tight junctions between neighboring cells when they have built up a confluent monolayer. Activities of most marker enzymes for cell-differentiated status and function of such cells observed over a period of 4 wk in culture were conserved compared with the original tissue. Lactate dehydrogenase activity release into the medium was at low levels (< or = 5% of the total amount), indicating a good membrane integrity and cell viability. The chromosome set (2n = 38) did not change significantly during the first 5 wk, but, with additional culture time, the degree of polyploid and polynucleated cells increased comparable to the in vivo situation, in which the apical cell layer of the bladder mucosa also showed a high degree of polynucleation and polyploidy, indicative of a senescence process.

Epithelial cells retain junctions during mitosis

1993 ◽  
Vol 104 (2) ◽  
pp. 415-425 ◽  
Author(s):  
J. Baker ◽  
D. Garrod
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Intercellular Junctions ◽  
Cell Types ◽  
Basal Keratinocytes ◽  
Tissue Integrity ◽  
Large Numbers ◽  
Cellular Junctions ◽  
Dividing Cells

It has long been known that cells show reduced cell-substratum adhesion during mitosis in tissue culture, but it is not generally known whether cell-cell adhesion is also reduced. Epithelial cells, both in culture and in tissues, are linked together by several different types of intercellular junctions. Are these junctions disassembled when epithelial cells divide? Cultured epithelial cells were fluorescently stained for desmosomes, tight junctions and zonulae adherentes, and large numbers of dividing cells examined by light microscopy. The results suggested that all three types of intercellular junctions were retained throughout cell division and no evidence for internalization of junctions was obtained. The persistence of intercellular junctions by cultured cells during division was confirmed by electron microscopy. In order to determine whether intercellular junctions were similarly retained by dividing cells in tissues, human colonic mucosal crypt cells and basal keratinocytes were studied by electron microscopy. Both cell types retained intercellular junctions during division. Dividing basal keratinocytes also possessed hemidesmosomal contact with the basement membrane. It is suggested that retention of cellular junctions during division is important for maintenance of tissue integrity and organization.

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

Adenomatoid Tumor of the Testis, A Mesonephric Hamartoma

1971 ◽  
Vol 29 ◽  
pp. 318-319
Author(s):  
Raoul Fresco ◽  
Mary Chang-Lo
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Fibrous Tissue ◽  
Salient Feature ◽  
Luminal Surface ◽  
Adenomatoid Tumor ◽  
Ultrastructural Studies ◽  
Epithelial Origin ◽  
Brush Borders ◽  
Cell Processes

Confusion surrounds the nature of the “adenomatoid tumor” of the testis, as evidenced by the large number of synonyms which have been ascribed to it. Various authors have considered the tumor to be of endothelial, mesothelial or epithelial origin. There appears to be no controversy as to the stromal elements of the tumor, which consists mainly of smooth muscle and fibrous tissue. It is the irregular gland-like spaces which have given rise to the numerous theories as to its histogenesis, and even recent ultrastructural studies fail to agree on the origin of these structures.Electron microscopy of a typical intrascrotal adenomatoid tumor showed the gland-like spaces to be lined by epithelial cells (Fig. 1), rich in cytoplasmic tonofibrils and united to each other by numerous desmosomes (Fig. 2). The most salient feature of these epithelial cells was the presence on their luminal surface of numerous long and repeatedly branching microvillous structures of the type known as stereocilia (Fig. 3). These are extremely long slender cell processes which are as much as three to four times the length of those in brush borders.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

1992 ◽  
Vol 50 (1) ◽  
pp. 506-507
Author(s):  
Robert L. Ochs
Keyword(s):  
Electron Microscopy ◽  
Structure And Function ◽  
Nuclear Bodies ◽  
Nuclear Interior ◽  
Coiled Bodies ◽  
Interchromatin Granules ◽  
And Function ◽  
Conventional Electron Microscopy ◽  
Perichromatin Granules ◽  
Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

Three-dimensional organization and functional relationships of endocytotic compartments in pig intestinal epithelial cells

1992 ◽  
Vol 50 (1) ◽  
pp. 576-577
Author(s):  
Julian P. Heath ◽  
Buford L. Nichols ◽  
László G. Kömüves
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Three Dimensional ◽  
Intestinal Epithelial ◽  
Cell Surfaces ◽  
Basal Surface ◽  
Functional Relationships

The newborn pig intestine is adapted for the rapid and efficient absorption of nutrients from colostrum. In enterocytes, colostral proteins are taken up into an apical endocytotic complex of channels that transports them to target organelles or to the basal surface for release into the circulation. The apical endocytotic complex of tubules and vesicles clearly is a major intersection in the routes taken by vesicles trafficking to and from the Golgi, lysosomes, and the apical and basolateral cell surfaces.Jejunal tissues were taken from piglets suckled for up to 6 hours and prepared for electron microscopy and immunocytochemistry as previously described.

Sign in / Sign up

Export Citation Format

Share Document