理化学研究所 生命機能科学研究センター

Laboratory of Biomolecular Informatics

猪股 秀彦 (Hidehiko Inomata)
mail hidehiko.inomata @ riken.jp
ポン リークン (Phng Li-Kun)
mail likun.phng @ riken.jp



理化学研究所 生命機能科学研究センター




発生過程は、複数の細胞が胚という限られた空間の中で互いに情報を交換しながら進行します。私たちは、情報交換の中心的な役割を果たしている濃度勾配に注目し、パターン形成の「理解」を目指しています。さらに、濃度勾配を人為的に胚内に「再構成」し、「制御」する系の開発を行います。このような技術を用いて、発生システムをより深く理解したいと考えています(猪股)。 The development of tissues and organs requires a supply of nutrients and oxygen and the removal of metabolic waste. This need is met by the formation of well-patterned networks of perfused blood vessels. The Phng Lab is interested in understanding how blood vessels are shaped and maintained during development and homeostasis. We combine genetics, molecular biology and pharmacological approaches with high resolution time-lapse imaging to investigate how endothelial cell shape and behaviour are regulated and coordinated to build vessels of specific size and architecture in the zebrafish embryo.(Phng)


細胞間のコミュニケーションは、秩序立った個体を形成するためにとても重要な役割を果たしています。もしコミュニケーションが存在しないと各々の細胞は好き勝手に行動し、私たちの体を構成している頭・手足などのパターン形成は崩壊してしまいます。当研究室は、脊椎動物(カエル・ゼブラフィッシュ)の体軸形成を指標に、モルフォゲンの濃度勾配依存的なパターン形成を研究しています。単純な濃度勾配から再現性の高い発生を保証するためには、発生システムが多少乱れても(擾乱:じょうらん)、モルフォゲンを介して細胞同士がコミュニケーションし柔軟に対応する必要があります(頑強性)。私たちは、外科的にカエル胚を半分に切除すると、モルフォゲンを介して細胞同士が互いに情報を交換し、半分のサイズの正しいパターンをもった胚が生まれることを明らかにしました。当研究室は、こうした頑強性を保証する発生システムを理解するために、モルフォゲンの可視化とin vivoイメージング、生化学的な手法を用いた定量解析を行います。



Diverse endothelial cell behaviors drive vessel formation

The formation of new blood vessels requires the tight coordination of many cellular processes such as collective cell migration, proliferation, cell rearrangements, anastomosis and lumen formation. To achieve this, endothelial cells undergo extensive cell shape changes to drive specific functions. In order to understand how cell shape regulation is achieved, we investigate the role of actin cytoskeleton in controlling endothelial membrane dynamics. Previous studies showed that during the expansion of blood vessels, the generation of actin bundles in filopodia facilitates efficient collective cell migration and anastomosis (Phng et al., 2013). During lumen formation, transient polymerization of F-actin at the apical membranes controls lumen expansion (Gebala et al., 2016) while a pool of actin cables at endothelial cell-cell junctions stabilizes newly-formed tubules to produce a functional vascular network (Phng et al., 2015). Our work therefore demonstrates that actin cytoskeleton of different dynamics and localisation drive distinct steps of vessel morphogenesis. Future studies in the lab include understanding how cortical actin organization is regulated to control membrane dynamics and endothelial cell shape.(Phng)

Endothelial cell mechanoresponse to blood flow forces

Once blood vessels become lumenized, endothelial cells are exposed to haemodynamic forces such as fluid shear stress and blood pressure. Recent work demonstrates that blood flow locally deforms the apical membrane of endothelial cells to generate inverse blebs during lumen formation (Gebala et al., 2016). In turn, endothelial cells counteract the deforming forces by triggering an actomyosin-dependent repair mechanism to retract the blebs. Furthermore, endothelial cells adapt to increasing haemodynamic forces by generating a cortex composed of a balanced network of linear and branched actin bundles that resist fluid forces (Kondrychyn et al., 2020). Future work in the lab is aimed at investigating the types and magnitude of haemodynamic forces (wall shear stress, luminal pressure) that endothelial cells are exposed to during vessel morphogenesis, and how endothelial cells sense and respond to changes in haemodynamic forces.(Phng)

図0 FRAP法を用いた拡散速度の定量。可視化したモルフォゲンを一部ブリーチすると(上中:赤枠)、周囲からブリーチした領域にモルフォゲンが流入する(上右)。ブリーチ領域での蛍光回復(下)。

図1 発生システムを理解・再構成・制御する。

図2 Endothelial cell proliferation during sprouting angiogenesis. Green, endothelial cell membrane. Magenta, endothelial cell nucleus.

図3 Organization of actin cytoskeleton in blood vessels.


Inomata, H., Shibata, T., Haraguchi, T., and Sasai, Y. Scaling of dorsal-ventral patterning by embryo size-dependent degradation of Spemann's organizer signals. Cell 153 , 1296 - 1311 (2013)

Takai, A., Inomata, H., Arakawa, A., Yakura, M., Matsuo-Takasaki, M., and Sasai, Y. Anterior neural development requires Del1, a matrix-associated protein that attenuates canonical Wnt signaling via the Ror2 pathway. Development 137 , 3293 - 3302 (2010)

Inomata, H., Haraguchi, T., and Sasai, Y. Robust stability of the embryonic axial pattern requires a secreted scaffold for chord in degradation. Cell 134 , 854 - 865 (2008)

Kondrychyn I, Kelly DJ, Taberner Carretero N, Nomori A, Kato K, Chong J, Nakajima H, Okuda S, Mochizuki N and Phng LK. Marcksl1 modulates endothelial cell mechanoresponse to haemodynamic forces to control blood vessel shape and size. NATURE COMMUNICATIONS , (2020)

Gebala V, Collins R, Geudens I, Phng LK and Gerhardt H Blood flow drives lumen formation by inverse membrane blebbing during angiogenesis in vivo. NATURE CELL BIOLOGY 18 , 443 - 451 (2016)

Phng LK,Gebala V, Bentley K, Philippides A, Wacker A, Mathivet T, Sauteur L, Stanchi S, HG Belting, Affolter M, Gerhardt H. Formin-mediated actin polymerization at endothelial junctions is required for vessel lumen formation and stabilization. DEVELOPMENTAL CELL 32 , 123 - 132 (2015)



TEL: 078-306-0111 FAX: 078-306-0101

猪股 秀彦(hidehiko.inomata@riken.jp)

ポン リークン(likun.phng@riken.jp)