Xenogeneic-Free Human Intestinal Organoids for Assessing Intestinal Nutrient Absorption.

Since many nutrients, including the three major ones of glucose, dipeptides, and cholesterol, are mainly absorbed in the small intestine, the assessment of their effects on intestinal tissue is important for the study of food absorption. However, cultured intestinal cell lines, such as Caco-2 cells, or animal models, which differ from normal human physiological conditions, are generally used for the evaluation of intestinal absorption and digestion. Therefore, it is necessary to develop an alternative in vitro method for more accurate analyses. In this study, we demonstrate inhibitory effects on nutrient absorption through nutrient transporters using three-dimensional xenogeneic-free human intestinal organoids (XF-HIOs), with characteristics of the human intestine, as we previously reported. We first show that the organoids absorbed glucose, dipeptide, and cholesterol in a transporter-dependent manner. Next, we examine the inhibitory effect of natural ingredients on the absorption of glucose and cholesterol. We reveal that glucose absorption was suppressed by epicatechin gallate or nobiletin, normally found in green tea catechin or citrus fruits, respectively. In comparison, cholesterol absorption was not inhibited by luteolin and quercetin, contained in some vegetables. Our findings highlight the usefulness of screening for the absorption of functional food substances using XF-HIOs.

Time-lapse image analysis for whole colony growth curves and daily distribution of the cell number per colony during the expansion of mesenchymal stem cells.

Mesenchymal stem cells from the synovium (synovial MSCs) are attractive for cartilage and meniscus regeneration therapy. We developed a software program that can distinguish individual colonies and automatically count the cell number per colony using time-lapse images. In this study, we investigated the usefulness of the software and analyzed colony formation in cultured synovial MSCs. Time-lapse image data were obtained for 14-day-expanded human synovial MSCs. The cell number per colony (for 145 colonies) was automatically counted from phase-contrast and nuclear-stained images. Colony growth curves from day 1 to day 14 (for 140 colonies) were classified using cluster analysis. Correlation analysis of the distribution of the cell number per colony at 14 days versus that number at 1-14 days revealed a correlation at 7 and 14 days. We obtained accurate cell number counts from phase-contrast images. Individual colony growth curves were classified into three main groups and subgroups. Our image analysis software has the potential to improve the evaluation of cell proliferation and to facilitate successful clinical applications using MSCs.

Intravital imaging with two-photon microscopy reveals cellular dynamics in the ischeamia-reperfused rat heart.

Recent advances in intravital microscopy have provided insight into dynamic biological events at the cellular level in both healthy and pathological tissue. However, real-time in vivo cellular imaging of the beating heart has not been fully established, mainly due to the difficulty of obtaining clear images through cycles of cardiac and respiratory motion. Here we report the successful recording of clear in vivo moving images of the beating rat heart by two-photon microscopy facilitated by cardiothoracic surgery and a novel cardiac stabiliser. Subcellular dynamics of the major cardiac components including the myocardium and its subcellular structures (i.e., nuclei and myofibrils) and mitochondrial distribution in cardiac myocytes were visualised for 4-5 h in green fluorescent protein-expressing transgenic Lewis rats at 15 frames/s. We also observed ischaemia/reperfusion (I/R) injury-induced suppression of the contraction/relaxation cycle and the consequent increase in cell permeability and leukocyte accumulation in cardiac tissue. I/R injury was induced in other transgenic mouse lines to further clarify the biological events in cardiac tissue. This imaging system can serve as an alternative modality for real time monitoring in animal models and cardiological drug screening, and can contribute to the development of more effective treatments for cardiac diseases.