Utility of human induced pluripotent stem cell-derived small intestinal epithelial cells for pharmacokinetic, toxicological, and immunological studies.

The small intestine, which plays a crucial role in the absorption and metabolism of drugs and foods, serves as a target organ for drug-induced toxicity and immune interactions with functional foods and intestinal bacteria. Current alternative models of the human small intestine, such as Caco-2 cells and experimental animals, have limitations due to variations in the expression levels of metabolic enzymes, transporters, and receptors. This study presents investigations into the utility of human induced pluripotent stem cell-derived small intestinal epithelial cells (hiSIECs) for pharmacokinetic, toxicological, and immunological studies, respectively. While hiSIECs displayed small intestinal epithelial cell characteristics and barrier function, they demonstrated pharmacokinetic properties such as cytochrome P450 3A4/5 activity equivalent to human primary enterocytes and stable P-glycoprotein activity. These cells also demonstrated potential for assessing two forms of intestinal toxicity caused by anticancer drugs and gamma-secretase inhibitors, displaying immune responses mediated by toll-like and fatty acid receptors while serving as an inflammatory gut model through the addition of tumor necrosis factor alpha and interferon gamma. Overall, hiSIECs hold promise as an in vitro model for assessing pharmacokinetics, toxicity, and effects on the intestinal immunity of pharmaceuticals, functional foods, supplements, and intestinal bacteria.

A Kinetic Pump Integrated Microfluidic Plate (KIM-Plate) with High Usability for Cell Culture-Based Multiorgan Microphysiological Systems.

Microphysiological systems (MPSs), including organ-on-a-chip (OoC), have attracted attention as a novel method for estimating the effects and side effects of drugs in drug discovery. To reproduce the dynamic in vivo environment, previous MPSs were connected to pump systems to perfuse culture medium. Therefore, most MPSs are not user-friendly and have poor throughput. We aimed to develop a kinetic pump integrated microfluidic plate (KIM-Plate) by applying the stirrer-based micropump to an open access culture plate to improve the usability of MPSs. The KIM-Plate integrates six multiorgan MPS (MO-MPS) units and meets the ANSI/SBS microplate standards. We evaluated the perfusion function of the kinetic pump and found that the KIM-Plate had sufficient agitation effect. Coculture experiments with PXB cells and hiPS intestinal cells showed that the TEER of hiPS intestinal cells and gene expression levels related to the metabolism of PXB cells were increased. Hence, the KIM-Plate is an innovative tool for the easy coculture of highly conditioned cells that is expected to facilitate cell-based assays in the fields of drug discovery and biology because of its usability and high throughput nature.

Lnk/Sh2b3 Regulates Adipose Inflammation and Glucose Tolerance through Group 1 ILCs.

Lnk/Sh2b3 is an adaptor protein that negatively regulates cytokine signaling in lymphohematopoiesis. A missense variant within the LNK/SH2B3 gene has been reported to be a risk variant for several autoimmune diseases, including diabetes. We found that glucose tolerance and insulin responses were impaired in Lnk-/- mice. Moreover, immune cells such as group 1 innate lymphoid cells (G1-ILCs), CD8+ T cells, and M1 macrophages accumulated in adipose tissue. When Lnk-/- mice were crossed with Il15-/- mice or depleted of G1-ILCs but not CD8+ T cells, glucose intolerance and adipose inflammation were ameliorated. Lnk-/- G1-ILCs showed activated phenotypes as well as enhanced reactivity for IL-15, and administration of a JAK inhibitor improved glucose tolerance. Accordingly, a high-fat diet greatly worsened glucose intolerance in Lnk-/- mice. Thus, Lnk/Sh2b3 controls homeostasis in adipose tissue and reduces the risk of onset of diabetes by regulating the expansion and activation of IL-15-dependent adipose G1-ILCs.

IL-10 production in murine IgM+ CD138hi cells is driven by Blimp-1 and downregulated in class-switched cells.

In contrast to antibody-induced inflammatory responses, some B-cell subpopulations suppress inflammation through the production of interleukin (IL)-10. However, the mechanisms underlying Il10 gene expression during B-cell development is elusive. Here, we identify IgM+ B220lo CD138hi cells responsible for marked IL-10 production in the bone marrow and spleen of mice. These murine IL-10-producing cells predominantly secrete IgM and have unique characteristics of long-lived plasma cells in spite of high expression of surface IgM. We found that IL-10 production is strongly correlated with the expression level of Prdm1 (encoding the Blimp-1 protein), an essential regulator of plasma cell development. Furthermore, overexpression of Prdm1 induces Il10 expression in naïve B cells. Immunoglobulin class-switching recombination events resulted in the downregulation of both Il10 and Prdm1 expression in differentiating B cells. Thus, the prolonged elevation of Blimp-1 expression during the formation of IgM+ CD138hi cells without class-switching elicits IL-10 production. Adoptive transfer of Il10-deficient B cells into B-cell-deficient mice demonstrated that IgM+ CD138hi cell-derived IL-10 supports the survival of class-switched plasma cells and their antibody production in response to antigen challenge. These findings reveal an important role for IL-10 secretion by IgM+ CD138hi cells in the complete and efficient humoral response.