1: Mini-Gut Organoids: Reconstitution of Stem Cell Niche.

ANNUAL REVIEW OF CELL AND DEVELOPMENTAL BIOLOGY

VOL 31,269-289; 10.1146/annurev-cellbio-100814-125218 2015

Date Shoichi, Sato Toshirov

Unlike iPS cells, which are used in research as pluripotent cells created by forcibly dedifferentiating somatic cells, organoid technology has been developed to reconstruct adult tissues themselves by directly culturing and expanding tissue stem cells, the source of somatic cells. Unlike conventional culture techniques, by reconstructing the in vivo stem cell microenvironment, or "niche," in a culture dish, a single tissue stem cell forms a three-dimensional tissue structure called an organoid (also known as a Mini-gut because of its resemblance to the intestine) in the dish. Organoid culture was first developed by the authors in 2009 based on mouse small intestinal stem cells and has since been applied to various tissues (such as the stomach, liver, pancreas, and prostate). Furthermore, organoid culture has also been applied to human tissues, and it is expected to have applications in various fields as a technology for reconstructing diseased human tissues ex vivo. This review, for which Dr. Tony Hunter provided the opportunity to write, outlines the achievements of organoid research and its future prospects. Within the School of Medicine, research is being advanced as part of the gastroenterology cluster research in Internal Medicine (Gastroenterology) and General and Gastroenterological surgery, and we hope to connect this to research achievements originating from the School of Medicine.

(Toshiro Sato, Division of Gastroenterology and Hepatology, 76th Graduating Class)

JOURNAL OF EXPERIMENTAL MEDICINE

NOV 16 2015, 212 (12):2133-2146; 10.1084

Nakamura-Ishizu Ayako, Takubo Keiyo, Kobayashi Hiroshi, Suzuki-Inoue Katsue, Suda Toshio

Homeostasis is maintained by the normal proliferation and differentiation of hematopoietic stem cells in the bone marrow. The bone marrow microenvironment (niche) is crucial for maintaining hematopoietic stem cells, and many non-hematopoietic cells, such as mesenchymal stem cells, have been analyzed as niche components. We reported that mature megakaryocytes function as a stem cell niche and that this function is regulated by CLEC-2, a membrane molecule on megakaryocytes. This revealed that stem cells receive feedback from their progeny cells, providing deeper insight into the maintenance of stem cell homeostasis. The lead author, Dr. Ishizu, is currently continuing her research at the Cancer Science Research Centers and Institutes (CSI), National University of Singapore (NUS), to further analyze the differentiation and function of megakaryocytes. The National University of Singapore offers a very vibrant and unique research environment where various Asian ethnicities and cultures intersect.

(Toshio Suda, 53rd Class equivalent, and Ayako Ishizu, International Research Center for Medical Sciences, Kumamoto University)