• Molecules and Cells
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• 제42권2호
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• pp.113-122
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• 2019

Communications at the interface between the apical membrane of follicular cells and the follicular lumen are critical for the homeostasis of thyroid gland. Primary cilia at the apical membrane of thyroid follicular cells may sense follicular luminal environment and regulate follicular homeostasis, although their role in vivo remains to be determined. Here, mice devoid of primary cilia were generated by thyroid follicular epithelial cell-specific deletion of the gene encoding intraflagellar transport protein 88 (Ift88). Thyroid follicular cellspecific Ift88-deficient mice showed normal folliculogenesis and hormonogenesis; however, those older than 7 weeks showed irregularly dilated and destroyed follicles in the thyroid gland. With increasing age, follicular cells with malignant properties showing the characteristic nuclear features of human thyroid carcinomas formed papillary and solid proliferative nodules from degenerated thyroid follicles. Furthermore, malignant tumor cells manifested as tumor emboli in thyroid vessels. These findings suggest that loss-of-function of Ift88/primary cilia results in malignant transformation from degenerated thyroid follicles.

• Molecules and Cells
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• 제41권7호
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• pp.676-683
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• 2018

Cilia are highly specialized antennae-like organelles that extend from the cell surface and act as cell signaling hubs. Intraflagellar transport (IFT) is a specialized form of intracellular protein trafficking that is required for the assembly and maintenance of cilia. Because cilia are so important, mutations in several IFT components lead to human disease. Thus, clarifying the molecular functions of the IFT proteins is a high priority in cilia biology. Live imaging in various species and cellular preparations has proven to be an important technique in both the discovery of IFT and the mechanisms by which it functions. Live imaging of Drosophila cilia, however, has not yet been reported. Here, we have visualized the movement of IFT in Drosophila cilia using time-lapse live imaging for the first time. We found that NOMPB-GFP (IFT88) moves according to distinct parameters depending on the ciliary segment. NOMPB-GFP moves at a similar speed in proximal and distal cilia toward the tip (${\sim}0.45{\mu}m/s$). As it returns to the ciliary base, however, NOMPB-GFP moves at ${\sim}0.12{\mu}m/s$ in distal cilia, accelerating to ${\sim}0.70{\mu}m/s$ in proximal cilia. Furthermore, while live imaging NOMPB-GFP, we observed one of the IFT proteins required for retrograde movement, Oseg4 (WDR35), is also required for anterograde movement in distal cilia. We anticipate our time-lapse live imaging analysis technique in Drosophila cilia will be a good starting point for a more sophisticated analysis of IFT and its molecular mechanisms.

• 한국발생생물학회지:발생과생식
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• 제28권3호
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• pp.109-119
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• 2024

The actin cytoskeleton plays fundamental roles in ciliogenesis and the actin depolymerizing factor destrin regulates actin dynamics by treadmilling actin filaments and increasing globular actin pools. However, the specific developmental roles of destrin in ciliogenesis have not been fully elucidated. Here, we investigated the function of destrin in ciliogenesis using Xenopus laevis and human retinal pigmented epithelial (hRPE1) cells. We discovered the loss of destrin increased the number of multiciliated cells in the Xenopus epithelium and impeded cilia motility. Additionally, destrin depletion remarkably reduced the length of primary cilia in the Xenopus neural tube and hRPE1 cells by affecting actin dynamics. Immunofluorescence using markers of ciliary components indicated that destrin controls the directionality and polarity of basal bodies and axonemal elongation by modulating actin dynamics, independent of basal body docking. In conclusion, destrin plays a significant role during vertebrate ciliogenesis regulating both primary and multicilia development. Our data suggest new insights for understanding the roles of actin dynamics in cilia development.

• Molecules and Cells
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• 제46권12호
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• pp.757-763
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• 2023

In this study, we examine whether a change in the protein levels for FOP in Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A)-deficient ependymal cells affects the intraflagellar transport (IFT) protein transport system in the multicilia. Three distinct abnormalities are observed in the multicilia of ANKS1A-deficient ependymal cells. First, there were a greater number of IFT88-positive trains along the cilia from ANKS1A deficiency. The results are similar to each isolated cilium as well. Second, each isolated cilium contains a significant increase in the number of extracellular vesicles (ECVs) due to the lack of ANKS1A. Third, Van Gogh-like 2 (Vangl2), a ciliary membrane protein, is abundantly detected along the cilia and in the ECVs attached to them for ANKS1A-deficient cells. We also use primary ependymal culture systems to obtain the ECVs released from the multicilia. Consequently, we find that ECVs from ANKS1A-deficient cells contain more IFT machinery and Vangl2. These results indicate that ANKS1A deficiency increases the entry of the protein transport machinery into the multicilia and as a result of these abnormal protein transports, excessive ECVs form along the cilia. We conclude that ependymal cells make use of the ECV-based disposal system in order to eliminate excessively transported proteins from basal bodies.

• BMB Reports
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• 제52권10호
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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.

• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.247-247
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• 2015

• 대한화장품학회지
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• 제44권1호
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• pp.73-79
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• 2018

일차 섬모(primary cilia)는 세포에서 안테나처럼 돌출되어 나온 기관인데, 외부 자극에 반응할 수 있는 각종 수용체와 채널, 신호 전달 인자들을 가지고 있다. 피부는 자외선, 온도, 습도, 중력, 장력 등 외부 환경에 반응하여 멜라닌이나 콜라겐을 만들고 피부 장벽을 형성한다. 피부에서는 일차 섬모가 없으면 헤어의 생성이나 각질의 분화가 억제된다는 보고가 있다. 또한 피부 색소 생성과 관련하여서는 일차 섬모가 sonic hedgehog-smoothened-GLI2 신호 전달에 의해 활성화되면 멜라닌 생성이 억제된다는 것이 알려져 있다. 피부가 자외선을 받으면 멜라닌 생성 호르몬의 양이 증가하고 멜라닌 생성 호르몬은 멜라닌 생성 세포 내 cAMP의 양을 증가시켜 멜라닌 생성 효소의 발현을 높인다. 이에 멜라닌 생성 호르몬과 세포 내 cAMP의 양을 증가시키는 물질을 처리하여 멜라닌 생성을 높였을 때 일차 섬모의 변화를 확인한 결과 일차 섬모가 감소하는 것을 확인하였다. 또한 기존 미백 원료인 유용성 감초 추출물(an ethanol extract of Glycyrrhiza glabra (EGG) root)과 Melasolv (3,4,5-trimethoxy cinnamate thymol ester (TCTE))가 일차 섬모의 발현을 증가시키고 멜라닌 생성 효소인 tyrosinase의 발현을 억제함을 확인할 수 있었다. 따라서 일차 섬모를 조절할 수 있다면 피부 색소 침착을 효과적으로 조절할 수 있을 것이다.

• BMB Reports
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• 제53권7호
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• pp.367-372
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• 2020

Cell cycle-related kinase (CCRK) has a conserved role in ciliogenesis, and Ccrk defects in mice lead to developmental defects, including exencephaly, preaxial polydactyly, skeletal abnormalities, retinal degeneration, and polycystic kidney. Here, we found that Ccrk is highly expressed in mouse trachea and bronchioles. Ccrk mutants exhibited pulmonary hypoplasia and abnormal branching morphogenesis in respiratory organ development. Furthermore, we demonstrated that Ccrk mutant lungs exhibit not only impaired branching morphogenesis but also a significant sacculation deficiency in alveoli associated with reduced epithelial progenitor cell proliferation. In pseudoglandular stages, Ccrk mutant lungs showed a downregulation of Hedgehog (Hh) signaling and defects in cilia morphology and frequency during progenitor-cell proliferation. Interestingly, we observed that activation of the Hh signaling pathway by small-molecule smoothened agonist (SAG) partially rescued bud morphology during branch bifurcation in explants from Ccrk mutant lungs. Therefore, CCRK properly regulates respiratory airway architecture in part through Hh-signal transduction and ciliogenesis.

• Biomolecules & Therapeutics
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• 제30권2호
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• pp.170-178
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• 2022

The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.

• Childhood Kidney Diseases
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• 제19권1호
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• pp.23-30
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• 2015

NPHP is the most common monogenic cause of CKD in children or adolescents. Extra-renal symptoms often accompany, therefore examination of retina, hearing, and skeleton is necessary in patients with CKD with insidious onset. Genes involved in NPHP-RC are mostly related in primary cilia. While genetic diagnosis is necessary for definitive diagnosis, there is no curative treatment.