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1.
J Cell Sci ; 134(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33468623

RESUMO

The molecular mechanisms by which cilia orientation is coordinated within and between multi-ciliated cells (MCCs) are not fully understood. In the mouse oviduct, MCCs exhibit a characteristic basal body (BB) orientation and microtubule gradient along the tissue axis. The intracellular polarities were moderately maintained in cells lacking CELSR1 (cadherin EGF LAG seven-pass G-type receptor 1), a planar cell polarity (PCP) factor involved in tissue polarity regulation, although the intercellular coordination of the polarities was disrupted. However, CAMSAP3 (calmodulin-regulated spectrin-associated protein 3), a microtubule minus-end regulator, was found to be critical for determining the intracellular BB orientation. CAMSAP3 localized to the base of cilia in a polarized manner, and its mutation led to the disruption of intracellular coordination of BB orientation, as well as the assembly of microtubules interconnecting BBs, without affecting PCP factor localization. Thus, both CELSR1 and CAMSAP3 are responsible for BB orientation but in distinct ways; their cooperation should therefore be critical for generating functional multi-ciliated tissues.

2.
Sci Rep ; 10(1): 17680, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077782

RESUMO

Behavioral responses to environmental factors at the planktonic larval stage can have a crucial influence on habitat selection and therefore adult distributions in many benthic organisms. Reef-building corals show strong patterns of zonation across depth or underwater topography, with different suites of species aggregating in different light environments. One potential mechanism driving this pattern is the response of free-swimming larvae to light. However, there is little experimental support for this hypothesis; in particular, there are few direct and quantitative observations of larval behavior in response to light. Here, we analyzed the swimming behavior of larvae of the common reef coral Acropora tenuis under various light conditions. Larvae exhibited a step-down photophobic response, i.e. a marked decrease in swimming speed, in response to a rapid attenuation (step-down) of light intensity. Observations of larvae under different wavelengths indicated that only the loss of blue light (wavelengths between 400 and 500 nm) produced a significant response. Mathematical simulations of this step-down photophobic response indicate that larvae will aggregate in the lighter areas of two-dimensional large rectangular fields. These results suggest that the step-down photophobic response of coral larvae may play an important role in determining where larval settle on the reef.

3.
Angiogenesis ; 2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32918673

RESUMO

Blood-brain barrier (BBB) dysfunction underlies the pathogenesis of many neurological diseases. Platelet-derived growth factor receptor-alpha (PDGFRα) induces hemorrhagic transformation (HT) downstream of tissue plasminogen activator in thrombolytic therapy of acute stroke. Thus, PDGFs are attractive therapeutic targets for BBB dysfunction. In the present study, we examined the role of PDGF signaling in the process of tissue remodeling after middle cerebral arterial occlusion (MCAO) in mice. Firstly, we found that imatinib increased lesion size after permanent MCAO in wild-type mice. Moreover, imatinib-induced HT only when administrated in the subacute phase of MCAO, but not in the acute phase. Secondly, we generated genetically mutated mice (C-KO mice) that showed decreased expression of perivascular PDGFRα. Additionally, transient MCAO experiments were performed in these mice. We found that the ischemic lesion size was not affected; however, the recruitment of PDGFRα/type I collagen-expressing perivascular cells was significantly downregulated, and HT and IgG leakage was augmented only in the subacute phase of stroke in C-KO mice. In both experiments, we found that the expression of tight junction proteins and PDGFRß-expressing pericyte coverage was not significantly affected in imatinib-treated mice and in C-KO mice. The specific implication of PDGFRα signaling was suggestive of protective effects against BBB dysfunction during the subacute phase of stroke. Vascular TGF-ß1 expression was downregulated in both imatinib-treated and C-KO mice, along with sustained levels of MMP9. Therefore, PDGFRα effects may be mediated by TGF-ß1 which exerts potent protective effects in the BBB.

4.
J Theor Biol ; 496: 110248, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32275986

RESUMO

Cell movement is crucial for morphogenesis in multicellular organisms. Growing embryos or tissues often expand isotropically, i.e., uniformly, in all dimensions. On the surfaces of these expanding environments, which we call "fields," cells are subjected to frictional forces and move passively in response. However, the potential roles of isotropically expanding fields in morphogenetic events have not been investigated well. Our previous mathematical simulations showed that a tissue was elongated on an isotropically expanding field (Imuta et al., 2014). However, the underlying mechanism remains unclarified, and how cells behave during tissue elongation was not investigated. In this study, we mathematically analyzed the effect of isotropically expanding fields using a vertex model, a standard type of multi-cellular model. We found that cells located on fields were elongated along a similar direction each other and exhibited a columnar configuration with nearly single-cell width. Simultaneously, it was confirmed that the cell clusters were also elongated, even though field expansion was absolutely isotropic. We then investigated the mechanism underlying these counterintuitive phenomena. In particular, we asked whether the dynamics of elongation was predominantly determined by the properties of the field, the cell cluster, or both. Theoretical analyses involving simplification of the model revealed that cell clusters have an intrinsic ability to asymmetrically deform, leading to their elongation. Importantly, this ability is effective only under the non-equilibrium conditions provided by field expansion. This may explain the elongation of the notochord, located on the surface of the growing mouse embryo. We established the mechanism underlying tissue elongation induced by isotropically expanding external environments, and its involvement in collective cell alignment with cell elongation, providing key insight into morphogenesis involving multiple adjacent tissues.

5.
Neuroscience ; 436: 11-26, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32278722

RESUMO

The platelet-derived growth factor receptor-α (PDGFRα) principally mediates growth factor signals in oligodendroglial progenitors and is involved in oligodendrogenesis and myelinogenesis in the developing spinal cord. However, the role of PDGFRα in the developing forebrain remains relatively unknown. We established a conditional knockout mouse for the Pdgfra gene (N-PRα-KO) using a Nestin promoter/enhancer-driven Cre recombinase and examined forebrain development. The expression of PDGFRα was efficiently suppressed in the Olig2+ cells in N-PRα-KO mice. In these mice, Olig2+ cells were slightly decreased during embryonic periods. The decrease was particularly striking during the postnatal period. The commitment of Pdgfra-inactivated Olig2+ cells to Sox10+ oligodendroglial-lineage was largely suppressed. Surviving Olig2+ cells and Sox10+ cells were distributed widely in the N-PRα-KO mouse brain, similarly to those in control mice until the early neonatal period. After that, these cells were drastically depleted in the forebrain during the second postnatal week. The brains of N-PRα-KO mice were severely hypomyelinated, and these mice died on approximately P17 with motor disturbances. Disturbed axonal fibers and extensively aberrant vascular formations appeared in the postnatal N-PRα-KO mouse brains. After the defective PDGFRα signal in the forebrain, these phenotypes were clearly different from those in the spinal cord that showed defective populations expansion and migration of oligodendroglial lineage and premature myelination, as previously described. In contrast, areas of severe hypomyelination were common to both anatomical sites. PDGFRα was critically involved in the myelination of the forebrain and may differently regulate oligodendroglial lineage between the forebrain and spinal cord.

6.
Biophys J ; 118(3): 742-752, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31952803

RESUMO

In mammals and birds, embryonic development of the heart involves conversion of a straight tubular structure into a three-dimensional helical loop, which is a chiral structure. We investigated theoretically the mechanism of helical loop formation of the mouse embryonic heart, especially focusing on determination of left-/right-handedness of the helical loop. In geometrical terms, chirality is the result of the combination of three axial asymmetries in three-dimensional space. We hypothesized the following correspondences between axial asymmetries and morphogenesis (bending and displacement): the dorsal-ventral asymmetry by ventral bending of a straight tube of the initial heart and the left-right and anterior-posterior asymmetries, the left-right asymmetry by rightward displacement of the heart tube, which is confined to the anterior region of the tube. Morphogenesis of chiral looping of the embryonic heart is a large-scaled event of the multicellular system in which substantial physical force operates dynamically. Using computer simulations with a cell-based physico-mechanical model and experiments with mouse embryos, we confirmed the hypothesis. We conclude that rightward displacement of the tube determines the left-handed screw of the loop. The process of helix loop formation consists of three steps: 1) the left-right biasing system involving Nodal-related signals that leads to left-right asymmetry in the embryonic body; 2) the rightward displacement of the tube; and finally 3) the left-handed helical looping. Step 1 is already established. Step 3 is elucidated by our study, which highlights the need for step 2 to be clarified; namely, we explore how the left-right asymmetry in the embryonic body leads to the rightward displacement of the heart tube.

7.
Dev Growth Differ ; 62(2): 118-128, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31943159

RESUMO

Morphogenesis and organ development should be understood based on a thorough description of cellular dynamics. Recent studies have explored the dynamic behaviors of mammalian neural progenitor cells (NPCs) using slice cultures in which three-dimensional systems conserve in vivo-like environments to a considerable degree. However, live observation of NPCs existing truly in vivo, as has long been performed for zebrafish NPCs, has yet to be established in mammals. Here, we performed intravital two-photon microscopic observation of NPCs in the developing cerebral cortex of H2B-EGFP or Fucci transgenic mice in utero. Fetuses in the uterine sac were immobilized using several devices and were observed through a window made in the uterine wall and the amniotic membrane while monitoring blood circulation. Clear visibility was obtained to the level of 300 µm from the scalp surface of the fetus, which enabled us to quantitatively assess NPC behaviors, such as division and interkinetic nuclear migration, within a neuroepithelial structure called the ventricular zone at embryonic day (E) 13 and E14. In fetuses undergoing healthy monitoring in utero for 60 min, the frequency of mitoses observed at the apical surface was similar to those observed in slice cultures and in freshly fixed in vivo specimens. Although the rate and duration of successful in utero observations are still limited (33% for ≥10 min and 14% for 60 min), further improvements based on this study will facilitate future understanding of how organogenetic cellular behaviors occur or are pathologically influenced by the systemic maternal condition and/or maternal-fetal relationships.

8.
Cell Rep ; 27(4): 1073-1089.e5, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018125

RESUMO

Oligodendrocyte progenitor cells (OPCs) are widely distributed cells of ramified morphology in adult brain that express PDGFRα and NG2. They retain mitotic activities in adulthood and contribute to oligodendrogenesis and myelin turnover; however, the regulatory mechanisms of their cell dynamics in adult brain largely remain unknown. Here, we found that global Pdgfra inactivation in adult mice rapidly led to elimination of OPCs due to synchronous maturation toward oligodendrocytes. Surprisingly, OPC densities were robustly reconstituted by the active expansion of Nestin+ immature cells activated in meninges and brain parenchyma, as well as a few OPCs that escaped from Pdgfra inactivation. The multipotent immature cells were induced in the meninges of Pdgfra-inactivated mice, but not of control mice. Our findings revealed powerful homeostatic control of adult OPCs, engaging dual cellular sources of adult OPC formation. These properties of the adult oligodendrocyte lineage and the alternative OPC source may be exploited in regenerative medicine.


Assuntos
Encéfalo/citologia , Células Precursoras de Oligodendrócitos/citologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Encéfalo/metabolismo , Diferenciação Celular , Linhagem da Célula , Homeostase , Meninges/citologia , Meninges/metabolismo , Camundongos , Nestina/metabolismo , Células Precursoras de Oligodendrócitos/metabolismo , Tecido Parenquimatoso/citologia
9.
Biophys Physicobiol ; 16: 89-107, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30923666

RESUMO

Organs and tissues in multi-cellular organisms exhibit various morphologies. Tubular organs have multi-scale morphological features which are closely related to their functions. Here we discuss morphogenesis and the mechanical functions of the vertebrate oviduct in the female reproductive tract, also known as the fallopian tube. The oviduct functions to convey eggs from the ovary to the uterus. In the luminal side of the oviduct, the epithelium forms multiple folds (or ridges) well-aligned along the longitudinal direction of the tube. In the epithelial cells, cilia are formed orienting toward the downstream of the oviduct. The cilia and the folds are supposed to be involved in egg transportation. Planar cell polarity (PCP) is developed in the epithelium, and the disruption of the Celsr1 gene, a PCP related-gene, causes randomization of both cilia and fold orientations, discontinuity of the tube, inefficient egg transportation, and infertility. In this review article, we briefly introduce various biophysical and biomechanical issues in the oviduct, including physical mechanisms of formation of PCP and organized cilia orientation, epithelial cell shape regulation, fold pattern formation generated by mechanical buckling, tubulogenesis, and egg transportation regulated by fluid flow. We also mention about possible roles of the oviducts in egg shape formation and embryogenesis, sinuous patterns of tubes, and fold and tube patterns observed in other tubular organs such as the gut, airways, etc.

10.
Sci Rep ; 9(1): 1172, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718617

RESUMO

The kidney possesses a highly organised vasculature that is required for its filtration function. While recent advances in stem cell biology have enabled the in vitro generation of kidney tissues, at least partially, recapitulation of the complicated vascular architecture remains a huge challenge. Herein we develop a method to reconstitute both the kidney and its vascular architecture in vitro, using dissociated and sorted mouse embryonic kidney cells. Upon transplantation, arteriolar networks were re-established that ran through the interstitial space between branching ureteric buds and eventually entered glomeruli. Using this system, we found that donor-derived endothelial cells significantly contributed to the arterioles and glomerular capillaries formed after transplantation. Unexpectedly, the near-complete depletion of canonical endothelial cells from the donor embryonic kidney suggested the existence of unidentified donor-derived endothelial precursors that were negative for canonical endothelial markers, but still contributed significantly to the vasculature in the transplants. Thus, our protocol will serve as a useful platform for identification of renal endothelial precursors and induction of these precursors from pluripotent stem cells.


Assuntos
Vasos Sanguíneos/crescimento & desenvolvimento , Rim/crescimento & desenvolvimento , Técnicas de Cultura de Órgãos/métodos , Engenharia Tecidual/métodos , Animais , Vasos Sanguíneos/embriologia , Transplante de Células , Células-Tronco Embrionárias/fisiologia , Células Endoteliais/fisiologia , Rim/embriologia , Camundongos
11.
Biol Reprod ; 100(5): 1204-1214, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30715198

RESUMO

Many mammalian species undergo embryonic diapause and suspend development at the blastocyst stage before implantation, which is also known as delayed implantation. We studied the process of how mouse embryos enter a dormancy status at a cellular level. Immunofluorescent analysis of differentiation markers for epiblast, primitive endoderm, and trophectoderm suggested that cell differentiation status was maintained during 7 days in diapause. To understand the progression of cellular dormancy during diapause, we examined the expression of a transgenic cell cycle marker Fucci2 and Ki67 by antibody staining, in addition to direct counting of nuclei in embryos. From these analyses, embryos during diapause were categorized into four stages by cell number and cell cycle. Cell cycle arrest occurred from the ab-embryonic region and from the trophectoderm to the ICM in the embryonic side. We also observed cell cycle transition by live imaging of Fucci2 embryos during the reactivation in culture from dormant status. Cell cycle was initially recovered from the embryonic side of embryos and eventually spread throughout the whole embryo. We also found that embryos in later stages of diapause required a longer period of time for reactivation. From these observations, it was shown that entrance into and exit from dormant status varied depending on cell types and location of cells in an embryo. These results suggest that embryonic diapause includes multiple steps and the mechanisms involved in cellular dormancy may be distinct between embryonic regions.


Assuntos
Blastocisto/citologia , Padronização Corporal/fisiologia , Diapausa/fisiologia , Desenvolvimento Embrionário/fisiologia , Animais , Blastocisto/fisiologia , Pontos de Checagem do Ciclo Celular/fisiologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Implantação do Embrião/fisiologia , Embrião de Mamíferos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Transgênicos , Gravidez , Fatores de Tempo
12.
Genesis ; 57(2): e23277, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30597711

RESUMO

Live imaging is one of the most powerful technologies for studying the behaviors of cells and molecules in living embryos. Previously, we established a series of reporter mouse lines in which specific organelles are labeled with various fluorescent proteins. In this study, we examined the localizations of fluorescent signals during preimplantation development of these mouse lines, as well as a newly established one, by time-lapse imaging. Each organelle was specifically marked with fluorescent fusion proteins; fluorescent signals were clearly visible during the whole period of time-lapse observation, and the expression of the reporters did not affect embryonic development. We found that some organelles dramatically change their sub-cellular distributions during preimplantation stages. In addition, by crossing mouse lines carrying reporters of two distinct colors, we could simultaneously visualize two types of organelles. These results confirm that our reporter mouse lines can be valuable genetic tools for live imaging of embryonic development.


Assuntos
Blastocisto/citologia , Citoesqueleto/metabolismo , Complexo de Golgi/metabolismo , Mitocôndrias/metabolismo , Animais , Transporte Biológico , Blastocisto/metabolismo , Divisão Celular , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Camundongos , Microscopia de Fluorescência/métodos , Junções Íntimas/metabolismo
13.
Gan To Kagaku Ryoho ; 46(13): 2084-2086, 2019 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-32157067

RESUMO

Solitary lung tumors after radical surgery for breast cancer often present difficulty in diagnosis and treatment. This report describes the case of a patient with a previous history of radicalsurgery for breast cancer who underwent lung surgery. Solitary pulmonary nodules should be diagnosed in patients with breast cancer, because treatments and prognoses differ between metastatic and primary tumors. At the age of 43 years, this patient underwent surgicaltreatment for breast cancer. Eighteen years later, a solitary mass was observed in the middle lobe of the right lung. Right middle lobectomy was performed using video-assisted thoracic surgery. The diagnosis was primary lung carcinoma. In case of primary lung carcinoma, radical treatment is possible through surgical resection. On the contrary, breast cancer metastasis has been known to have subtypes with characteristics that may often be different from those of the originall esions; therefore, surgicalresection helps in the reevaluation of receptor expression. Thus, early pathological diagnosis using surgical resection is useful for early diagnosis and treatment.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Nódulo Pulmonar Solitário , Neoplasias da Mama/cirurgia , Humanos , Pessoa de Meia-Idade , Prognóstico , Cirurgia Torácica Vídeoassistida
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 1026-1030, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31946068

RESUMO

Segmentation is a fundamental process in biomedical image analysis that enables various types of analysis. Segmenting organs in histological microscopy images is problematic because the boundaries between regions are ambiguous, the images have various appearances, and the amount of training data is limited. To address these difficulties, supervised learning methods (e.g., convolutional neural networking (CNN)) are insufficient to predict regions accurately because they usually require a large amount of training data to learn the various appearances. In this paper, we propose a semi-automatic segmentation method that effectively uses scribble annotations for metric learning. Deep discriminative metric learning re-trains the representation of the feature space so that the distances between the samples with the same class labels are reduced, while those between ones with different class labels are enlarged. It makes pixel classification easy. Evaluation of the proposed method in a heart region segmentation task demonstrated that it performed better than three other methods.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação
15.
Gan To Kagaku Ryoho ; 46(13): 2249-2251, 2019 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-32156894

RESUMO

We report a patient with occult breast cancer who underwent axillary dissection as primary surgery. The patient, a 68-yearold woman, noticed a tumor measuring approximately 3 cm in diameter, in her left axilla. Biopsy of the axillary tumor revealed adenocarcinoma. Imaging studies did not detect primary lesions in the mammary gland or other organs. The patient was diagnosed with occult breast cancer and underwent axillary dissection but did not desire mastectomy or radiation therapy. The patient was closely observed thereafter. Tamoxifen was prescribed for 5 years but left breast cancer was detected 14 years after the operation. A simple mastectomy was performed. She died of respiratory failure 1 year later. Occult breast cancer may require axillary lymph node dissection and systemic therapy. Breast preservation could be an alternative treatment if followed by adequate systemic therapy and close observation.


Assuntos
Neoplasias da Mama , Idoso , Axila , Neoplasias da Mama/cirurgia , Terapia Combinada , Feminino , Humanos , Excisão de Linfonodo , Linfonodos , Metástase Linfática , Mastectomia , Recidiva Local de Neoplasia , Fatores de Tempo
16.
Biochem Biophys Res Commun ; 509(2): 435-440, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30594398

RESUMO

We recently found that the membrane-bound receptor activator of NF-κB ligand (RANKL) on osteoblasts works as a receptor to stimulate osteoblast differentiation, however, the reason why the RANKL-binding molecules stimulate osteoblast differentiation has not been well clarified. Since the induction of cell-surface receptor clustering is known to lead to cell activation, we hypothesized that the induction of membrane-RANKL clustering on osteoblasts might stimulate osteoblast differentiation. Immunoblotting showed that the amount of RANKL on the membrane was increased by the RANKL-binding peptide OP3-4, but not by osteoprotegerin (OPG), the other RANKL-binding molecule, in Gfp-Rankl-transfected ST2 cells. Observation under a high-speed atomic force microscope (HS-AFM) revealed that RANKL molecules have the ability to form clusters. The induction of membrane-RANKL-OPG-Fc complex clustering by the addition of IgM in Gfp-Rankl-transfected ST2 cells could enhance the expression of early markers of osteoblast differentiation to the same extent as OP3-4, while OPG-Fc alone could not. These results suggest that the clustering-formation of membrane-RANKL on osteoblasts could stimulate early osteoblast differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Oligopeptídeos/farmacologia , Osteoblastos/efeitos dos fármacos , Peptidomiméticos/farmacologia , Ligante RANK/genética , Animais , Sítios de Ligação , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Regulação da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/metabolismo , Imunoglobulina M/genética , Imunoglobulina M/metabolismo , Camundongos , Microscopia de Força Atômica , Modelos Moleculares , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Osteoblastos/metabolismo , Osteoblastos/ultraestrutura , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Peptidomiméticos/química , Peptidomiméticos/metabolismo , Ligação Proteica , Ligante RANK/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Fatores de Tempo
17.
Cell Physiol Biochem ; 51(3): 1461-1479, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30485861

RESUMO

BACKGROUND/AIMS: The migration of mesenchymal cells is a fundamental cellular process that has been implicated in many pathophysiological conditions and is induced by chemoattractants such as platelet-derived growth factors (PDGFs). However, the regulatory mechanisms shaping this migration remain to be elucidated. METHODS: Here, we prepared mouse skin fibroblasts inactivated for different PDGF receptor genes and systematically measured their chemotactic responses within a gradient of different chemoattractants. RESULTS: We found that PDGFRαß and PDGFRßß dimers were strong inducers of random and directionally-persistent migration, respectively, that was sustained for up to 24 h. MAPK and PI3K were necessary to mediate random and directional migration, respectively. Directional migration was accompanied by abundant ventral stress fiber formation and consistent cell shape with less frequent formation of branch-like processes. CONCLUSION: This is the first systematic study that characterized the chemotaxis mediated by three-different types of PDGFR dimers in mesenchymal cell migration. Our data demonstrate that PDGFR dimer formation is the critical step to determine the specific mode of fibroblast chemotaxis, while the accompanying cytoskeletal remodeling might contribute to migration persistence.


Assuntos
Movimento Celular , Fibroblastos/citologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Quimiotaxia , Fibroblastos/metabolismo , Técnicas de Inativação de Genes , Camundongos , Multimerização Proteica , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Transdução de Sinais , Pele/citologia , Pele/metabolismo
18.
Proc Natl Acad Sci U S A ; 115(50): 12817-12822, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30482854

RESUMO

PIEZO1 is a cation channel that is activated by mechanical forces such as fluid shear stress or membrane stretch. PIEZO1 loss-of-function mutations in patients are associated with congenital lymphedema with pleural effusion. However, the mechanistic link between PIEZO1 function and the development or function of the lymphatic system is currently unknown. Here, we analyzed two mouse lines lacking PIEZO1 in endothelial cells (via Tie2Cre or Lyve1Cre) and found that they exhibited pleural effusion and died postnatally. Strikingly, the number of lymphatic valves was dramatically reduced in these mice. Lymphatic valves are essential for ensuring proper circulation of lymph. Mechanical forces have been implicated in the development of lymphatic vasculature and valve formation, but the identity of mechanosensors involved is unknown. Expression of FOXC2 and NFATc1, transcription factors known to be required for lymphatic valve development, appeared normal in Tie2Cre;Piezo1 cKO mice. However, the process of protrusion in the valve leaflets, which is associated with collective cell migration, actin polymerization, and remodeling of cell-cell junctions, was impaired in Tie2Cre;Piezo1 cKO mice. Consistent with these genetic findings, activation of PIEZO1 by Yoda1 in cultured lymphatic endothelial cells induced active remodeling of actomyosin and VE-cadherin+ cell-cell adhesion sites. Our analysis provides evidence that mechanically activated ion channel PIEZO1 is a key regulator of lymphatic valve formation.


Assuntos
Canais Iônicos/metabolismo , Linfangiogênese/fisiologia , Sistema Linfático/metabolismo , Sistema Linfático/fisiologia , Vasos Linfáticos/metabolismo , Vasos Linfáticos/fisiologia , Actomiosina/metabolismo , Animais , Antígenos CD/metabolismo , Caderinas/metabolismo , Adesão Celular/fisiologia , Movimento Celular/fisiologia , Células Endoteliais/metabolismo , Células Endoteliais/fisiologia , Fatores de Transcrição Forkhead/metabolismo , Junções Intercelulares/metabolismo , Junções Intercelulares/fisiologia , Transporte de Íons/fisiologia , Camundongos , Fatores de Transcrição NFATC/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo
19.
Development ; 145(22)2018 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-30327323

RESUMO

The early post-implantation mouse embryo changes dramatically in both size and shape. These morphological changes are based on characteristic cellular behaviors, including cell growth and allocation. To perform clonal analysis, we established a Cre/loxP-based reporter mouse line, R26R-ManGeKyou, that enables clonal labeling with multiple colors. We also developed a novel ImageJ plugin, LP-Clonal, for quantitative measurement of the tilt angle of clonal cluster shape, enabling identification of the direction of cluster expansion. We carried out long-term and short-term lineage tracking. We also performed time-lapse imaging to characterize cellular behaviors using R26-PHA7-EGFP and R26R-EGFP These images were subjected to quantitative image analyses. We found that the proximal visceral endoderm overlying the extra-embryonic ectoderm shows coherent cell growth in a proximal-anterior to distal-posterior direction. We also observed that directional cell migration is coupled with cell elongation in the anterior region. Our observations suggest that the behaviors of visceral endoderm cells vary between regions during peri-implantation stages.


Assuntos
Endoderma/citologia , Endoderma/embriologia , Processamento de Imagem Assistida por Computador , RNA não Traduzido/metabolismo , Vísceras/embriologia , Animais , Blastômeros/citologia , Forma Celular , Células Clonais , Implantação do Embrião , Embrião de Mamíferos/metabolismo , Feminino , Gastrulação , Integrases/metabolismo , Masculino , Camundongos , Especificidade de Órgãos , Imagem com Lapso de Tempo
20.
Curr Opin Genet Dev ; 51: 59-66, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30006099

RESUMO

Tubular organs and tissues often show various morphological fold patterns in their luminal epithelia. Computational studies have revealed that these patterns could be explained by mechanical deformation of the epithelia. However, experimental validations of this are sparse, and the mechanisms linking genetic and cellular functions to fold mechanics are poorly understood. In the oviduct of the female reproductive tract, the epithelium forms multiple well-aligned straight folds. Disruption of Celsr1, a planar cell polarity-related gene, causes ectopically-branched folds in mice. Here we discuss the pattern formation of the folds with respect to the growth and mechanics of the epithelium, and the cellular and genetic functions, and compare these with other tubular organs such as the gut.


Assuntos
Polaridade Celular/genética , Genitália Feminina/crescimento & desenvolvimento , Animais , Fenômenos Biomecânicos , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Epitélio/crescimento & desenvolvimento , Feminino , Camundongos , Oviductos/crescimento & desenvolvimento
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