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45 results on '"Yamashita, Tadahiro"'

9. Endothelial-Smooth Muscle Cell Interactions in a Shear-Exposed Intimal Hyperplasia on-a-Dish Model to Evaluate Therapeutic Strategies

Author

Fernandes, Andreia; https://orcid.org/0000-0003-4638-6546, Miéville, Arnaud; https://orcid.org/0000-0002-2662-4888, Grob, Franziska, Yamashita, Tadahiro; https://orcid.org/0000-0003-2168-9567, Mehl, Julia, Hosseini, Vahid, Emmert, Maximilian Y, Falk, Volkmar; https://orcid.org/0000-0002-7911-8620, Vogel, Viola; https://orcid.org/0000-0003-2898-7671, Fernandes, Andreia; https://orcid.org/0000-0003-4638-6546, Miéville, Arnaud; https://orcid.org/0000-0002-2662-4888, Grob, Franziska, Yamashita, Tadahiro; https://orcid.org/0000-0003-2168-9567, Mehl, Julia, Hosseini, Vahid, Emmert, Maximilian Y, Falk, Volkmar; https://orcid.org/0000-0002-7911-8620, and Vogel, Viola; https://orcid.org/0000-0003-2898-7671

Abstract

Intimal hyperplasia (IH) represents a major challenge following cardiovascular interventions. While mechanisms are poorly understood, the inefficient preventive methods incentivize the search for novel therapies. A vessel-on-a-dish platform is presented, consisting of direct-contact cocultures with human primary endothelial cells (ECs) and smooth muscle cells (SMCs) exposed to both laminar pulsatile and disturbed flow on an orbital shaker. With contractile SMCs sitting below a confluent EC layer, a model that successfully replicates the architecture of a quiescent vessel wall is created. In the novel IH model, ECs are seeded on synthetic SMCs at low density, mimicking reendothelization after vascular injury. Over 3 days of coculture, ECs transition from a network conformation to confluent 2D islands, as promoted by pulsatile flow, resulting in a "defected" EC monolayer. In defected regions, SMCs incorporated plasma fibronectin into fibers, increased proliferation, and formed multilayers, similarly to IH in vivo. These phenomena are inhibited under confluent EC layers, supporting therapeutic approaches that focus on endothelial regeneration rather than inhibiting proliferation, as illustrated in a proof-of-concept experiment with Paclitaxel. Thus, this in vitro system offers a new tool to study EC-SMC communication in IH pathophysiology, while providing an easy-to-use translational disease model platform for low-cost and high-content therapeutic development. Keywords: drug screening; endothelial cell networks; flow; in vitro coculture model; vascular injury.

Published
2022

24. Progress report of second lecture exchange meetings of young investigators

Author

AONO, Hikaru, primary, UJIHARA, Yoshihiro, additional, OTANI, Tomohiro, additional, OMORI, Toshihiro, additional, KAMEO, Yoshitaka, additional, KIM, Jeonghyun, additional, KURAMOTO, Akisue, additional, SAITO, Takumi, additional, SHIGEMATSU, Taiki, additional, TAKEISHI, Naoki, additional, NIX, Stephanie, additional, MAKI, Koichiro, additional, MINAMIKAWA, Takeo, additional, YAMASHITA, Tadahiro, additional, and YAMADA, Satoshi, additional

Published
2020
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45. Ex vivo SIM-AFM measurements reveal the spatial correlation of stiffness and molecular distributions in 3D living tissue.

Author

Shioka I, Morita R, Yagasaki R, Wuergezhen D, Yamashita T, Fujiwara H, and Okuda S

Abstract

Living tissues each exhibit a distinct stiffness, which provides cells with key environmental cues that regulate their behaviors. Despite this significance, our understanding of the spatiotemporal dynamics and the biological roles of stiffness in three-dimensional tissues is currently limited due to a lack of appropriate measurement techniques. To address this issue, we propose a new method combining upright structured illumination microscopy (USIM) and atomic force microscopy (AFM) to obtain precisely coordinated stiffness maps and biomolecular fluorescence images of thick living tissue slices. Using mouse embryonic and adult skin as a representative tissue with mechanically heterogeneous structures inside, we validate the measurement principle of USIM-AFM. Live measurement of tissue stiffness distributions revealed the highly heterogeneous mechanical nature of skin, including nucleated/enucleated epithelium, mesenchyme, and hair follicle, as well as the role of collagens in maintaining its integrity. Furthermore, quantitative analysis comparing stiffness distributions in live tissue samples with those in preserved tissues, including formalin-fixed and cryopreserved tissue samples, unveiled the distinct impacts of preservation processes on tissue stiffness patterns. This series of experiments highlights the importance of live mechanical testing of tissue-scale samples to accurately capture the true spatiotemporal variations in mechanical properties. Our USIM-AFM technique provides a new methodology to reveal the dynamic nature of tissue stiffness and its correlation with biomolecular distributions in live tissues and thus could serve as a technical basis for exploring tissue-scale mechanobiology. STATEMENT OF SIGNIFICANCE: Stiffness, a simple mechanical parameter, has drawn attention in understanding the mechanobiological principles underlying the homeostasis and pathology of living tissues. To explore tissue-scale mechanobiology, we propose a technique integrating an upright structured illumination microscope and an atomic force microscope. This technique enables live measurements of stiffness distribution and fluorescent observation of thick living tissue slices. Experiments revealed the highly heterogeneous mechanical nature of mouse embryonic and adult skin in three dimensions and the previously unnoticed influences of preservation techniques on the mechanical properties of tissue at microscopic resolution. This study provides a new technical platform for live stiffness measurement and biomolecular observation of tissue-scale samples with micron-scale resolution, thus contributing to future studies of tissue- and organ-scale mechanobiology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Published
2024
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