論文 - 久保田　義顕

A MST1–FOXO1 cascade establishes endothelial tip cell polarity and facilitates sprouting angiogenesis

Kim Y., Choi J., Yang M., Hong S., Lee C., Kubota Y., Lim D., Koh G.

Nature Communications （Nature Communications）  10 （ 1 ）  2019年12月

　概要を見る

© 2019, The Author(s). Hypoxia is a main driver of sprouting angiogenesis, but how tip endothelial cells are directed to hypoxic regions remains poorly understood. Here, we show that an endothelial MST1–FOXO1 cascade is essential for directional migration of tip cells towards hypoxic regions. In mice, endothelial‐specific deletion of either MST1 or FOXO1 leads to the loss of tip cell polarity and subsequent impairment of sprouting angiogenesis. Mechanistically, MST1 is activated by reactive oxygen species (ROS) produced in mitochondria in response to hypoxia, and activated MST1 promotes the nuclear import of FOXO1, thus augmenting its transcriptional regulation of polarity and migration‐associated genes. Furthermore, endothelial MST1‐FOXO1 cascade is required for revascularization and neovascularization in the oxygen-induced retinopathy model. Together, the results of our study delineate a crucial coupling between extracellular hypoxia and an intracellular ROS‐MST1‐FOXO1 cascade in establishing endothelial tip cell polarity during sprouting angiogenesis.

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p53 plays a crucial role in endothelial dysfunction associated with hyperglycemia and ischemia

Yokoyama M., Shimizu I., Nagasawa A., Yoshida Y., Katsuumi G., Wakasugi T., Hayashi Y., Ikegami R., Suda M., Ota Y., Okada S., Fruttiger M., Kobayashi Y., Tsuchida M., Kubota Y., Minamino T.

Journal of Molecular and Cellular Cardiology （Journal of Molecular and Cellular Cardiology）  129   105 - 117 2019年04月

ISSN  00222828

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© 2019 Elsevier Ltd p53 is a guardian of the genome that protects against carcinogenesis. There is accumulating evidence that p53 is activated with aging. Such activation has been reported to contribute to various age-associated pathologies, but its role in vascular dysfunction is largely unknown. The aim of this study was to investigate whether activation of endothelial p53 has a pathological effect in relation to endothelial function. We established endothelial p53 loss-of-function and gain-of-function models by breeding endothelial-cell specific Cre mice with floxed Trp53 or floxed Mdm2/Mdm4 mice, respectively. Then we induced diabetes by injection of streptozotocin. In the diabetic state, endothelial p53 expression was markedly up-regulated and endothelium-dependent vasodilatation was significantly impaired. Impairment of vasodilatation was significantly ameliorated in endothelial p53 knockout (EC-p53 KO) mice, and deletion of endothelial p53 also significantly enhanced the induction of angiogenesis by ischemia. Conversely, activation of endothelial p53 by deleting Mdm2/Mdm4 reduced both endothelium-dependent vasodilatation and ischemia-induced angiogenesis. Introduction of p53 into human endothelial cells up-regulated the expression of phosphatase and tensin homolog (PTEN), thereby reducing phospho-eNOS levels. Consistent with these results, the beneficial impact of endothelial p53 deletion on endothelial function was attenuated in EC-p53 KO mice with an eNOS-deficient background. These results show that endothelial p53 negatively regulates endothelium-dependent vasodilatation and ischemia-induced angiogenesis, suggesting that inhibition of endothelial p53 could be a novel therapeutic target in patients with metabolic disorders.

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Tie2 activation promotes choriocapillary regeneration for alleviating neovascular age-related macular degeneration

Kim J., Park J., Choi J., Park I., Hwang Y., Bae H., Kim Y., Choi W., Yang J., Han S., Chung T., Kim P., Kubota Y., Augustin H., Oh W., Koh G.

Science Advances （Science Advances）  5 （ 2 ）  2019年02月

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Copyright © 2019 The Authors. Choriocapillary loss is a major cause of neovascular age-related macular degeneration (NV-AMD). Although vascular endothelial growth factor (VEGF) blockade for NV-AMD has shown beneficial outcomes, unmet medical needs for patients refractory or tachyphylactic to anti-VEGF therapy exist. In addition, the treatment could exacerbate choriocapillary rarefaction, necessitating advanced treatment for fundamental recovery from NV-AMD. In this study, Tie2 activation by angiopoietin-2–binding and Tie2-activating antibody (ABTAA) presents a therapeutic strategy for NV-AMD. Conditional Tie2 deletion impeded choriocapillary maintenance, rendering eyes susceptible to NV-AMD development. Moreover, in a NV-AMD mouse model, ABTAA not only suppressed choroidal neovascularization (CNV) and vascular leakage but also regenerated the choriocapillaris and relieved hypoxia. Conversely, VEGF blockade degenerated the choriocapillaris and exacerbated hypoxia, although it suppressed CNV and vascular leakage. Together, we establish that angiopoietin-Tie2 signaling is critical for choriocapillary maintenance and that ABTAA represents an alternative, combinative therapeutic strategy for NV-AMD by alleviating anti-VEGF adverse effects.

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TAK1 Prevents Endothelial Apoptosis and Maintains Vascular Integrity

Naito H., Iba T., Wakabayashi T., Tai-Nagara I., Suehiro J., Jia W., Eino D., Sakimoto S., Muramatsu F., Kidoya H., Sakurai H., Satoh T., Akira S., Kubota Y., Takakura N.

Developmental Cell （Developmental Cell）  48 （ 2 ） 151 - 166.e7 2019年01月

ISSN  15345807

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© 2018 Elsevier Inc. Mechanisms by which endothelial cells (ECs) maintain themselves in inflammatory microenvironments remain unclear. Naito et al. show that TAK1 prevents EC apoptosis induced by TNF-α-expressing myeloid cells. TAK1 protects ECs and ensures the maintenance of vascular integrity and homeostasis under inflammatory conditions.

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Angiopoietin-2 exacerbates cardiac hypoxia and inflammation after myocardial infarction

Lee S., Lee C., Kang S., Park I., Kim Y., Kim S., Hong S., Bae H., He Y., Kubota Y., Koh G.

Journal of Clinical Investigation （Journal of Clinical Investigation）  128 （ 11 ） 5018 - 5033 2018年11月

ISSN  00219738

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© 2018 American Society for Clinical Investigation. All rights reserved. Emerging evidence indicates that angiopoietin-2 (Angpt2), a well-recognized vascular destabilizing factor, is a biomarker of poor outcome in ischemic heart disease. However, its precise role in postischemic cardiovascular remodeling is poorly understood. Here, we show that Angpt2 plays multifaceted roles in the exacerbation of cardiac hypoxia and inflammation after myocardial ischemia. Angpt2 was highly expressed in endothelial cells at the infarct border zone after myocardial infarction (MI) or ischemia/reperfusion injury in mice. In the acute phase of MI, endothelial-derived Angpt2 antagonized Angpt1/Tie2 signaling, which was greatly involved in pericyte detachment, vascular leakage, increased adhesion molecular expression, degradation of the glycocalyx and extracellular matrix, and enhanced neutrophil infiltration and hypoxia in the infarct border area. In the chronic remodeling phase after MI, endothelial- and macrophage-derived Angpt2 continuously promoted abnormal vascular remodeling and proinflammatory macrophage polarization through integrin α 5 β 1 signaling, worsening cardiac hypoxia and inflammation. Accordingly, inhibition of Angpt2 either by gene deletion or using an anti- Angpt2 blocking antibody substantially alleviated these pathological findings and ameliorated postischemic cardiovascular remodeling. Blockade of Angpt2 thus has potential as a therapeutic option for ischemic heart failure.

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Hematopoietic insults damage bone marrow niche by activating p53 in vascular endothelial cells

Si S., Nakajima-Takagi Y., Iga T., Tsuji M., Hou L., Oshima M., Koide S., Saraya A., Yamazaki S., Takubo K., Kubota Y., Minamino T., Iwama A.

Experimental Hematology （Experimental Hematology）  63   41 - 51.e1 2018年07月

ISSN  0301472X

　概要を見る

© 2018 Elsevier Ltd Hematopoietic stem cells (HSCs) are exposed to various insults such as genotoxic stress, inflammation, and infection, which have a direct effect. These insults deplete, cause a functional decline in, and promote HSC aging and transformation. However, the impact of hematopoietic insults on niche cells remains largely unknown. We have reported previously that p53 is activated in blood vessels by various stresses, including hypoxia, inflammation, and aging, and contributes to tissue dysfunction and metabolic abnormalities. We hypothesized that hematopoietic insults also affect the bone marrow (BM) vascular niche. Here, we demonstrate that p53 becomes activated in BM endothelial cells upon hematopoietic stresses such as irradiation and chemotherapeutic treatments. The conditional activation of p53 in VE-cadherin+ vascular niche cells by deleting Mdm2 induces the expression of p53 target genes specifically in vascular endothelial cells, resulting in the dilation and collapse of vascular endothelial cells and reductions in perivascular mesenchymal stromal cell numbers. Consequently, hematopoietic stem cells (HSCs) fail to maintain dormancy, mobilize to the periphery, and are depleted significantly. Our results indicate that various hematopoietic insults affect HSCs, not only directly, but also indirectly by altering vascular integrity, which is critical for perivascular niche formation and maintenance of HSCs.

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Distinct expression patterns of Flk1 and Flt1 in the coronary vascular system during development and after myocardial infarction

Kurotsu S., Osakabe R., Isomi M., Tamura F., Sadahiro T., Muraoka N., Kojima H., Haginiwa S., Tani H., Nara K., Kubota Y., Ema M., Fukuda K., Suzuki T., Ieda M.

Biochemical and Biophysical Research Communications （Biochemical and Biophysical Research Communications）  495 （ 1 ） 884 - 891 2018年01月

ISSN  0006291X

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© 2017 Elsevier Inc. The coronary vascular system is critical for myocardial growth and cardiomyocyte survival. However, the molecular mechanism regulating coronary angiogenesis remains elusive. Vascular endothelial growth factor (VEGF) regulates angiogenesis by binding to the specific receptors Flk1 and Flt1, which results in different functions. Despite the importance of Flk1 and Flt1, their expression in the coronary vasculature remains largely unknown due to the lack of appropriate antibodies for immunostaining. Here, we analyzed multiple reporter mice including Flk1-GFP BAC transgenic (Tg), Flk1-LacZ knock-in, Flt1-DsRed BAC Tg, and Flk1-GFP/Flt1-DsRed double Tg animals to determine expression patterns in mouse hearts during cardiac growth and after myocardial infarction (MI). We found that Flk1 was expressed in endothelial cells (ECs) with a pattern of epicardial-to-endocardial transmural gradients in the neonatal mouse ventricle, which was downregulated in adult coronary vessels with development. In contrast, Flt1 was homogeneously expressed in the ECs of neonatal mouse hearts and expression was maintained until adulthood. After MI, expression of both Flk1 and Flt1 was induced in the regenerating coronary vessels at day 7. Intriguingly, Flk1 expression was downregulated thereafter, whereas Flt1 expression was maintained in the newly formed coronary vessels until 30 days post-MI, recapitulating their expression kinetics during development. This is the first report demonstrating the spatiotemporal expression patterns of Flk1 and Flt1 in the coronary vascular system during development and after MI; thus, this study suggests that these factors have distinct and important functions in coronary angiogenesis.

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YAP/TAZ regulates sprouting angiogenesis and vascular barrier maturation.

Kim J, Kim YH, Kim J, Park DY, Bae H, Lee DH, Kim KH, Hong SP, Jang SP, Kubota Y, Kwon YG, Lim DS, *Koh GY.

J Clin Invest 127 （ 9 ） 3441 - 3461 2017年

研究論文（学術雑誌）, 共著, 査読有り

Plastic roles of pericytes in the blood-retinal barrier

Park DY, Lee J, Kim J, Kim K, Hong S, Han S, Kubota Yoshiaki, Augustin HG, Ding L, Kim JW, Kim H, He Y, Adams RH, *Koh GY.

Nat Commun 8   15296 - 15296 2017年

研究論文（学術雑誌）, 査読有り

VEGFR2 but not VEGFR3 governs integrity and remodeling of thyroid angiofollicular unit in normal state and during goitrogenesis.

Jang JY, Choi SY, Park I, Park DY, Choe K, Kim P, Kim YK, Lee BJ, Hirashima M, Kubota Yoshiaki,Park JW, Cheng SY, Nagy A, Park YJ, Alitalo K, Shong M, *Koh GY.

EMBO Mol Med 9 （ 6 ） 750 - 769 2017年

研究論文（学術雑誌）, 共著, 査読有り

Tissue Myeloid Progenitors Differentiate into Pericytes through TGF-β Signaling in Developing Skin Vasculature.

Yamazaki T, Nalbandian A, Uchida Y, Li W, Arnold TD,Kubota Yoshiaki, Yamamoto S, Ema M, *Mukouyama YS.

Cell Rep 18 （ 12 ） 2991 - 3004 2017年

研究論文（学術雑誌）, 共著, 査読有り

Placental labyrinth formation in mice requires endothelial FLRT2–UNC5B signaling.

1. Tai-Nagara I, Yoshikawa Y, Numata N, Ando T, Okabe K, Sugiura Y, Ieda M, Takakura N, Nakagawa O, Zhou B, Okabayashi K, Suematsu M, Kitagawa Y, Bastmeyer M, Sato K, Klein R, Navankasattusas S, Li DY, Yamagishi S,*Kubota Yoshiaki

Development 144 （ 13 ） 2392 - 2401 2017年

研究論文（学術雑誌）, 共著, 査読有り

Impaired angiopoietin/Tie2 signaling compromises Schlemm's canal integrity and induces glaucoma.

Kim J, Park DY, Bae H, Park DY, Kim D, Lee CK, Song S, Chung TY, Lim DH, Kubota Y, Hong YK, He Y, Augustin HG, Oliver G, *Koh GY.

J Clin Invest 127 （ 10 ） 3877 - 3896 2017年

研究論文（学術雑誌）, 共著, 査読有り

Developmental regression of hyaloid vasculature is triggered by neurons.

Yoshikawa Yusuke, Yamada Toru, Tai-Nagara Ikue, Okabe Keisuke, Kitagawa Yuko, Ema masatsugu, *Kubota Yoshiaki

J Exp Med 213 （ 7 ） 1175 - 1193 2016年

研究論文（学術雑誌）, 共著, 査読有り

p38α activates purine metabolism to initiate hematopoietic stem/progenitor cell cycling

Karigane D, Kobayashi H, Morikawa T, Ootomo Y, Sakai M, Nagamatsu G, Kubota Yoshiaki, Goda N, Matsumoto M, Nishimura EK, Soga T, Otsu K, Suematsu M, Okamoto S, Suda T, *Takubo K

Cell Stem Cell 19 （ 2 ） 192 - 204 2016年

研究論文（学術雑誌）, 共著, 査読有り

The P2X4 receptor is required for neuroprotection via ischemic preconditioning.

Ozaki T, *Muramatsu R, Sasai M, Yamamoto M, Kubota Yoshiaki, Fujinaka T, Yoshimine T, *Yamashita T

Sci Rep 6   25893 - 25893 2016年

研究論文（学術雑誌）, 共著, 査読有り

SoxF Transcription Factors Are Positive Feedback Regulators of VEGF Signaling.

Kim K, Kim IK, Yang JM, Lee E, Koh BI, Song S, Park J, Lee S, Choi C, Kim JW, Kubota Yoshiaki, Koh GY and *Kim I.

Circ Res 119 （ 7 ） 839 - 852 2016年

研究論文（学術雑誌）, 共著, 査読有り

VEGFR3 does not sustain retinal angiogenesis without VEGFR2

Zarkada G, Heinolainen K, Makinen T, Kubota Y and *Alitalo K

Proc Natl Acad Sci USA 112 （ 3 ） 761 - 766 2015年

研究論文（学術雑誌）, 共著, 査読有り

Perilipin+ embryonic preadipocytes actively proliferate along growing vasculatures for adipose expansion.

Hong KY, Bae H, Park I, Park DY, Kim KH, Kubota Y, Cho ES, Kim H, Adams RH, Yoo OJ, *Koh GY.

Development 142 （ 15 ） 2623 - 2632 2015年

研究論文（学術雑誌）, 共著, 査読有り

Osteogenic capillaries orchestrate growth plate-independent ossification of the malleus.

*Matsuo K, Kuroda Y, Nango N, Shimoda K, Kubota Yoshiaki, Ema M, Bakiri L, Wagner EF, Takeda Y, Yashiro W and Momose A

Development 142 （ 22 ） 3912 - 3920 2015年

研究論文（学術雑誌）, 共著, 査読有り