• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.388-395
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• 2017

We investigated the toxicity of zinc and aluminum hot-dip galvanized sheet steel to abalone Haliotis discus hannai via changes in the gill and hepatopancreas using histological and transmission electron microscopy analysis. Experimental groups were composed of one control and four exposure conditions (direct or indirect exposure to zinc and aluminum hot-dip galvanized sheet steel). In the control group, aluminum exposure groups (direct and indirect), and indirect zinc exposure group, abalone mortality was not observed until the end of the experiment, and no histopathological changes were observed in the gill and hepatopancreas. However, the direct zinc exposure group exhibited 100% mortality. Ultrastructural analysis of the cytoplasm of ciliated and microvilli-bearing epithelial cells from gill filaments revealed electron-dense vesicles near the cell membrane and disruption of the nuclear membrane. We also observed swollen mitochondria and a loss of mitochondrial cristae. The hepatopancreas showed similar changes, and we detected highly electron-dense particles within the vesicles. These results suggest that abalone exposed directly to zinc hot-dip galvanized sheet steel experience acute toxicity, causing damage to cell organelles in the gill and hepatopancreas and, finally, inducing mortality.

• Animal Systematics, Evolution and Diversity
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• v.24 no.2
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• pp.191-197
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• 2008

Specimens of Diophrys appendiculata (Ehrenberg, ] 838) and D. scutum (Dujardin, 1841) have been collected from the coastal and brackish waters around near Ulsan, during 2004-2007. Diophrys appendiculata and D. scutum are described taxonomically for the first time in Korea. Diagnostic characteristics of these species are as follows. Diophrys appendiculata: size in vivo $43-68{\times}25-50{\mu}m$, adoral zone of membranelles (AZM) covering 43-74% of cell length in impregnated and 46-65% in vivo specimens with 32-47 adoral membranelles (AM). Paroral membrane is slightly curved. Four to five dorsal kinetal (DK) rows are fragmented and anterior and posterior parts of rows densely ciliated. Two macronuclear nodules (Ma) irregular and elongated oval in shape and widely separated. D. scutum: size in vivo $125-225{\times}75-140{\mu}m$, AZM extending to the middle of right border of body and covering 50-60% of cell length with 56-75 AMs. Body shape is typically ovoid with prominent concave margin at right posterio-lateral end, and rather thick and wide longitudinal ridge along lower buccal cavity on ventral side. Two macronuclei shaped like a sausage. five to six dorsal kineties.

• Applied Microscopy
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• v.25 no.1
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• pp.48-64
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• 1995

Ultrastructure of nerves and their associated cells in the bronchiolar epithelium of the human fetal lung were studied with ultrastructural and immunohistochemical methods. The neuroendocrine cells were scattered along the basal part of non-ciliated respiratory epithelium and appeared as single cell (solitary neuroendocrine cell) or groups (neuroepithelial bodies). The solitary neuroendocrine cells were devoid of any detectable innervation, while the neuroepithelial bodies were associated with nerve ending containing morphologically afferent (sensory) and efferent (motor) intraepithelial terminals. The afferent nerve endings contained abundant mitochondria with long cristae. The efferent nerve endings were characterized by the presence of synaptic vesicles. Both types of nerve endings formed synaptic junction between nerve endings and neuroepithelial bodies cells. Serial sections of the intraepithelial nerves revealed that both morphologically afferent and efferent types of nerve endings may be formed by the same nerve fiber. By immunohistochemistry, bombesin and serotonin were localized in solitary neuroendocrine cells and neuroepithelial bodies of human fetal lung from various prenatal age groups. These results suggest that the neuroepithelial bodies cells of the human fetal lung have neuroreceptor function.

• Applied Microscopy
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• v.32 no.3
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• pp.213-222
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• 2002

Histology and ultrastructure of the mantle epidermis in the ark shell, Scapharca broughtonii are described using light and electron microscopy. The mantle of the ark shell is composed of outer epidermis, connective tissue and inner epidermis. Both epidermis are simple and consists of supporting cells, ciliated cells and secretory cells. Connective tissue is composed of mainly collagen and muscle fibers. The supporting cells in the inner epidermis are usually columnar and covered with microvilli. The ciliated cell have cilia and microvilli on the free surface, and numerous tubular mitochondria are observed in the apical cytoplasm. Secretory cells are mainly observed in the outer epidermis, and it can be divided into four types of A, B, C and D with morphological features of the secretory granules. Type A cells of mucous cell are found in the marginal and central mantle. And these cells contains numerous secretory granules of non-bounded and low electron density. Type B cells contains numerous rough endoplasmic reticula, well-developed Golgi complex and secretory granules of membrane-bounded and high electron density. Secretory granules of type C cells are divided into fibrous core layer and homogeneous peripheral layer. Type D cells are found in the outer epidermis of the central and umbonal mantle. And secretory granules of these cells are divided into homogeneous core layer and granular peripheral layer. This results suggest that the outer and inner epidermis of the mantle are related with shell formation and cleaning of the mantle cavity, respectively.

• Molecules and Cells
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• v.46 no.12
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• pp.746-756
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• 2023

A recent study revealed that the loss of Deup1 expression does not affect either centriole amplification or multicilia formation. Therefore, the deuterosome per se is not a platform for amplification of centrioles. In this study, we examine whether gain-of-function of Deup1 affects the development of multiciliated ependymal cells. Our time-lapse study reveals that deuterosomes with an average diameter of 300 nm have two different fates during ependymal differentiation. In the first instance, deuterosomes are scattered and gradually disappear as cells become multiciliated. In the second instance, deuterosomes self-organize into a larger aggregate, called a deuterosome cluster (DC). Unlike scattered deuterosomes, DCs possess centriole components primarily within their large structure. A characteristic of DC-containing cells is that they tend to become primary ciliated rather than multiciliated. Our in utero electroporation study shows that DCs in ependymal tissue are mostly observed at early postnatal stages, but are scarce at late postnatal stages, suggesting the presence of DC antagonists within the differentiating cells. Importantly, from our bead flow assay, ectopic expression of Deup1 significantly impairs cerebrospinal fluid flow. Furthermore, we show that expression of mouse Deup1 in Xenopus embryos has an inhibitory effect on differentiation of multiciliated cells in the epidermis. Taken together, we conclude that the DC formation of Deup1 in multiciliated cells inhibits production of multiple centrioles.

• Applied Microscopy
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• v.30 no.1
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• pp.45-59
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• 2000

Cis-platin is a widely used anticancer drug against certain solid tumors such as malignant ovarian tumor, malignant carcinoma of head and neck, bladder cancer and cervical cancer of uterus, and its major mechanism of action is inhibition of DNA synthesis of the tumor cell. To investigate the inhibitory effects of cis-platin on the ciliogensis of the ciliated cells in the mucosa of oviduct, the author pursued the alterations of $\alpha-tubulin$, which is the main constituent of the microtubles in cilia, after cis-platin treatment. To eliminate the possible variations due to ovarian cycle, female Spargue-Dawley rats ($150\sim200gm$ in B.W.) were pretreated with estradiol benzoate (20 mg/kg, once a day, for 4 consecutive days). Animals were administrated with cis-platin (6 mg/kg, i.p.) and sacrificed at 1day, 3days, 5days and 7days after treatment, respectively. Immunohistochemistry for $\alpha-tubulin$ using mouse anti-rat $\alpha-tubulin$ monoclonal antibody as primary antibody was done. Immunogold electronmicroscopy for intracellular distributions of $\alpha-tubulin$ was also performed with same primary antibody and Goat anti- mouse IgM which is preconjugated with gold particles of 15 nm as secondary antibody. The results obtained were as follows; 1. Strong immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1, 3 and 5 days after estradiol pretreatment. 2. Weak immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1 and 3 days after cis-platin treatment but it was recovered to strong immunoreactivity in 5 days 3. In immunogold electronmicroscopy, density of gold particles for $\alpha-tubulin$ reactions was decreased in apical cytoplasm, but few changes were observed in basal body or cilia at 1 and 3 days after cis-platin treatment. From these above results, it is indicated that synthesis of $\alpha-tubulin$ in ciliated cells of rat oviduct is inhibited by cis-platin treatment.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.81-87
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• 2003

The digestive system of the abalone, Haliotis discus hannai consists of radula sac, esophagus, crop, stomach, intestine (anterior, mid and posterior intestine) and hepatopancreas. The epithelial layer was composed of ciliated columnar cells, mucous cells and granular cells. And epithelium thickness of the crop was thicker (90.80 ${\mu}$m) than those of other regions. Mucous cells of PAS positive in the esophagus were more advanced than those of other regions. The contents of mucous cell were neutral and acid mucosubstance in the esophagus and the anterior, mid and posterior intestine. And it seem to be lipid in the crop and stomach.

• BMB Reports
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• v.52 no.10
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• pp.619-624
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• 2019

The primary cilium is a microtubule-based structure projecting from a cell. Although the primary cilium shows no motility, it can recognize environmental stimuli. Thus, ciliary defects cause severe abnormalities called ciliopathies. Ciliogenesis is a very complex process and involves a myriad of components and regulators. In order to excavate the novel positive regulators of ciliogenesis, we performed mRNA microarray using starved NIH/3T3 cells. We selected 62 murine genes with corresponding human orthologs, with significantly upregulated expression at 24 h after serum withdrawal. Finally, calpain-6 was selected as a positive regulator of ciliogenesis. We found that calpain-6 deficiency reduced the percentage of ciliated cells and impaired sonic hedgehog signaling. It has been speculated that this defect might be associated with decreased levels of ${\alpha}-tubulin$ acetylation at lysine 40. This is the first study to report a novel role of calpain-6 in the formation of primary cilia.

• Molecules and Cells
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• v.42 no.3
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• pp.245-251
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• 2019

Ependymal cells constitute the multi-ciliated epithelium, which lines the brain ventricular lumen. Although ependymal cells originate from radial glial cells in the perinatal rodent brain, the exact mechanisms underlying the full differentiation of ependymal cells are poorly understood. In this report, we present evidence that the Anks1a phosphotyrosine binding domain (PTB) adaptor is required for the proper development of ependymal cells in the rodent postnatal brain. Anks1a gene trap targeted LacZ reporter analysis revealed that Anks1a is expressed prominently in the ventricular region of the early postnatal brain and that its expression is restricted to mature ependymal cells during postnatal brain development. In addition, Anks1a-deficient ependymal cells were shown to possess type B cell characteristics, suggesting that ependymal cells require Anks1a in order to be fully differentiated. Finally, Anks1a overexpression in the lateral wall of the neonatal brain resulted in an increase in the number of ependymal cells during postnatal brain development. Altogether, our results suggest that ependymal cells require Anks1a PTB adaptor for their proper development.

• IMMUNE NETWORK
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• v.21 no.1
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• pp.3.1-3.16
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• 2021

Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide since its outbreak in December 2019, and World Health Organization declared it as a pandemic on March 11, 2020. SARS-CoV-2 is highly contagious and is transmitted through airway epithelial cells as the first gateway. SARS-CoV-2 is detected by nasopharyngeal or oropharyngeal swab samples, and the viral load is significantly high in the upper respiratory tract. The host cellular receptors in airway epithelial cells, including angiotensin-converting enzyme 2 and transmembrane serine protease 2, have been identified by single-cell RNA sequencing or immunostaining. The expression levels of these molecules vary by type, function, and location of airway epithelial cells, such as ciliated cells, secretory cells, olfactory epithelial cells, and alveolar epithelial cells, as well as differ from host to host depending on age, sex, or comorbid diseases. Infected airway epithelial cells by SARS-CoV-2 in ex vivo experiments produce chemokines and cytokines to recruit inflammatory cells to target organs. Same as other viral infections, IFN signaling is a critical pathway for host defense. Various studies are underway to confirm the pathophysiological mechanisms of SARS-CoV-2 infection. Herein, we review cellular entry, host-viral interactions, immune responses to SARS-CoV-2 in airway epithelial cells. We also discuss therapeutic options related to epithelial immune reactions to SARS-CoV-2.