Establishment of the improved colonization of Escherichia coli laboratory strain in the intestine mediated by single gene deletion.

In light of the emerging importance of the gut microbiome in human health, there is a need to improve the colonization efficiency of therapeutic bacteria called probiotics. Despite their recognized potential, artificially administered bacteria exhibit poor colonization in the intestine, limiting their therapeutic efficacy. Addressing this challenge requires innovative strategies; however, reported examples are limited.

Endogenous IFN-γ facilitates Pneumocystis infection and downregulates carbohydrate receptors in CD4 T cell-depleted mice.

IFN-γ plays a critical role in host defense against intracellular pathogens. IFN-γ is produced in the bronchoalveolar lavage fluid of mice infected with Pneumocystis, but the role of IFN-γ in host defense against Pneumocystis remains controversial. It has been previously reported that although exogenous IFN-γ has beneficial effects on eradication of Pneumocystis, endogenous IFN-γ has a negative impact on innate immunity in immunocompromised hosts.

Syngeneic implantation of mouse hepatic progenitor cell-derived three-dimensional liver tissue with dense collagen fibrils.

Background: Liver transplantation is a therapy for irreversible liver failure; however, at present, donor organs are in short supply. Cell transplantation therapy for liver failure is still at the developmental stage and is critically limited by a shortage of human primary hepatocytes.

Aim: To investigate the possibility that hepatic progenitor cells (HPCs) prepared from the portal branch-ligated hepatic lobe may be used in regenerative medicine, we attempted to enable the implantation of extracellular matrices containing organoids consisting of HPC-derived hepatocytes and non-parenchymal cells.

Osteoclast formation from mouse bone marrow cells on micro/nano-scale patterned surfaces.

Objectives: Osteoclasts can sense the surface topography of materials. However, it is difficult to identify the structural factors that affect osteoclast formation and its function. Furthermore, we hypothesized that the type of osteoclast precursor cells also affects osteoclastogenesis in the materials.

Visualized procollagen Iα1 demonstrates the intracellular processing of propeptides.

The processing of type I procollagen is essential for fibril formation; however, the steps involved remain controversial. We constructed a live cell imaging system by inserting fluorescent proteins into type I pre-procollagen α1. Based on live imaging and immunostaining, the C-propeptide is intracellularly cleaved at the perinuclear region, including the endoplasmic reticulum, and subsequently accumulates at the upside of the cell.

Human DC3 Antigen Presenting Dendritic Cells From Induced Pluripotent Stem Cells.

Dendritic cells (DC) are professional antigen-presenting cells that develop from hematopoietic stem cells. Different DC subsets exist based on ontogeny, location and function, including the recently identified proinflammatory DC3 subset. DC3 have the prominent activity to polarize CD8 T cells into CD8 CD103 tissue resident T cells.

Hepatocytes and Endothelial Networks in a Fluid-Based Model of Liver Drug Metabolism.

Drug-induced liver toxicity remains a major cause of drug withdrawal from animal testing and human clinical trials. A functional liver culture model corresponding to the liver is urgently required; however, in previous liver models, it has proven difficult to stably maintain multiple liver functions. Previously reported fluid-based systems have some advantages for hepatocyte culture, but have insufficient liver-specific functions because they simply involve moving conventional hepatocyte cultures from a dish into a fluid-based system.

Human iPS cell-derived astrocytes support efficient replication of progressive multifocal leukoencephalopathy-type JC polyomavirus.

JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system, in immunocompromised patients. Although PML used to be rare, recently the incidence of PML has risen due to an increase in immunosuppressive therapy. An in vitro JCPyV infection system could be used for anti-drug screening and investigation of tropism changes, but study of JCPyV in vitro has been limited due to the difficulty of efficiently propagating the virus in cultured cells.

Acetaminophen-induced hepatotoxicity of cultured hepatocytes depends on timing of isolation from light-cycle controlled mice.

Most physiological changes follow a daily cycle in animals because their circadian rhythm is adjusted to and synchronized with sunlight. In particular, the circadian rhythm affects liver functions, including pharmacokinetics and metabolism. The influence of circadian rhythm has not been included in hepatotoxicity assays used in drug discovery and development.

Acorbine, a Corbicula japonica-derived tripeptide containing non-proteinogenic amino acids, suppresses ethanol-induced liver injury.

Since ancient times, Corbicula extract has been believed in Japan to have hepatoprotective effects, but it remains unclear whether these claims are true, and if so, which component is responsible for hepatoprotection. In this study, we showed that Corbicula extract exerted a protective effect against liver damage. Recent work identified acorbine (β-alanyl-ornithyl-ornithine), a novel tripeptide containing non-proteinogenic amino acids, in the extract of Corbicula japonica.

MazF activation causes ACA sequence-independent and selective alterations in RNA levels in Escherichia coli.

Escherichia coli MazF is a toxin protein that cleaves RNA at ACA sequences. Its activation has been thought to cause growth inhibition, primarily through indiscriminate cleavage of RNA. To investigate responses following MazF activation, transcriptomic profiles of mazF-overexpressing and non-overexpressing E.

Contribution of rat embryonic stem cells to xenogeneic chimeras in blastocyst or 8-cell embryo injection and aggregation.

The ultimate goal of regenerative medicine is the transplantation of a target organ generated by the patient's own cells. Recently, a method of organ generation using pluripotent stem cells (PSCs) and blastocyst complementation was reported. This approach is based on chimeric animal generation using an early embryo and PSCs, and the contribution of PSCs to the target organ is key to the method's success.

Inhibitory effect of the extract of rhizome of Curcuma longa L in gelatinase activity and its effect on human skin.

Exposure to UV radiation to human skin up-regulates the synthesis of matrix metalloproteinase (MMP) family. Gelatinases are member of MMPs which have been suggested to play an important role in photoaging such as wrinkle formation. To inhibit gelatinase activity is regarded to be very important to keep healthy skin and to protect wrinkle formation.

Development of hepatoma-derived, bidirectional oval-like cells as a model to study host interactions with hepatitis C virus during differentiation.

Directed differentiation of human stem cells including induced pluripotent stem cells into hepatic cells potentially leads to acquired susceptibility to hepatitis C virus (HCV) infection. However, cellular determinants that change their expression during cell reprogramming or hepatic differentiation and are pivotal for supporting the HCV life cycle remain unclear. In this study, by introducing a set of reprogramming factors, we established HuH-7-derived oval-like cell lines, Hdo-17 and -23, which possess features of bipotential liver precursors.

Metabolomics of an in vitro liver model containing primary hepatocytes assembling around an endothelial cell network: comparative study on the metabolic stability and the effect of acetaminophen treatment.

Recently, a novel culture system consisting of primary hepatocytes structured over a network of endothelial cells on the Engelbreth-Holm-Swarm (EHS) gel has been reported. This in vitro liver model on the EHS gel (IVL) has been shown to maintain the expression of hepatic genes and their functional activity. Moreover, the IVL was more sensitive to xenobiotics than hepatocyte monocultures, suggesting the potential utility of this culture system for compound hepatotoxicity screening.

Nitric oxide is critical for avoiding hepatic lipid overloading via IL-6 induction during liver regeneration after partial hepatectomy in mice.

Nitric oxide (NO), generated from L-arginine by three different isoforms of nitric oxide synthase (NOS), is a pleiotropic factor to regulate physiological functions in almost every organ and tissue. Each knockout mouse of iNOS or eNOS has been used to suggest that NO has a crucial role in liver regeneration after partial hepatectomy (PH), for NO may inhibit caspase 3 activity and is required for EGFR signaling. In previous reports, defective mitochondrial β-oxidation was observed in eNOS KO mice, and hepatic steatosis was often correlated to deficient liver regeneration, so we focused on metabolic perspective and hypothesized that NO depletion in PH mice would affect hepatocytic lipolysis and impair hepatocytes proliferation.

Optimized Ultrasonic Irradiation Finds Out Ultrastable Aβ Oligomers.

Oligomer species of amyloid β (Aβ) peptides are intensively investigated because of their relevance to Alzheimer's disease (AD), and a stable oligomer will be a cause of AD. In this article, we investigate the structural stability of two representative Aβ oligomers, which are with and without the β-sheet structure, denoted by β and non-β oligomers, respectively, using optimized ultrasonic irradiation (OUI). Recent studies reveal that OUI significantly accelerates the fibril formation in Aβ monomers; it is capable of transforming any unstable oligomers into fibrils (the dead-end products) in a short time.

A novel aldosterone synthase inhibitor ameliorates mortality in pressure-overload mice with heart failure.

It has been elucidated that mineralocorticoid receptor antagonists reduce mortality in patients with congestive heart failure and post-acute myocardial infarction. A direct inhibition of aldosterone synthase (CYP11B2) is also expected to have therapeutic benefits equal in quality to mineralocorticoid receptor antagonists in terms of reducing mineralocorticoid receptor signaling. Therefore, we have screened our chemical libraries and identified a novel and potent aldosterone synthase inhibitor, 2,2,2-trifluoro-1-{4-[(4-fluorophenyl)amino]pyrimidin-5-y}-1-[1-(methylsulfonyl)piperidin-4-yl]ethanol (compound 1), by lead optimization.

Transdifferentiation of mouse visceral yolk sac cells into parietal yolk sac cells in vitro.

The mouse embryonic yolk sac is an extraembryonic membrane that consists of a visceral yolk sac (VYS) and parietal yolk sac (PYS), and functions in hematopoietic-circulation in the fetal stage. The present study was undertaken to examine the normal development of both murine VYS and PYS tissues using various molecular markers, and to establish a novel VYS cell culture system in vitro for analyzing differentiation potentials of VYS cells. RT-PCR and immunohistochemical analyses of gene expression in VYS and PYS tissues during development revealed several useful markers for their identification: HNF1β, HNF4α, Cdh1 (E-cadherin), Krt8 and Krt18 for VYS epithelial cells, and Stra6, Snail1, Thbd and vimentin for PYS cells.

An in vitro liver model consisting of endothelial vascular networks surrounded by human hepatoma cell lines allows for improved hepatitis B virus replication.

The life cycle of viruses, from infection to budding, is dependent upon the physiological activity of the host cells, such as expression of cell surface proteins, activities of organelles and transcription factors and so on. Human hepatitis viruses exploit multiple hepatocyte pathways during their life cycle; however, primary hepatocytes dramatically lose function and die when cultured as a monolayer in vitro. We previously reported the development of an in vitro liver model, IVL, consisting of endothelial networks and mouse primary hepatocytes.

Dynamic chemotactic response of fibroblasts to local stimulation using EGF-immobilized microbeads.

Directional cellular migrations as a chemotactic response to spatially inhomogeneous growth factor stimulation play an important role in establishing physiological mechanisms and pathological events in cells. We developed epidermal growth factor (EGF)-immobilized microbeads by photoreaction and evaluated its local stimulatory effects on the dynamic chemotactic motility of fibroblasts. The local stimulation resulted in global activation of ERK 1/2 and directionality of cellular migration.

Expression of the rodent-specific alternative splice variant of tryptophanyl-tRNA synthetase in murine tissues and cells.

Tryptophanyl-tRNA synthetase (TrpRS) catalyzes the aminoacylation of tRNA(Trp). mRNA of a rodent-specific alternative splice variant of TrpRS (SV-TrpRS), which results in the inclusion of an additional hexapeptide at the C-terminus of full-length TrpRS (FL-TrpRS), has been identified in murine embryonic stem (ES) cells. In the present study, we evaluated the expression of mouse TrpRS mRNA by real-time reverse transcription PCR.

Innate immunity in an in vitro murine blastocyst model using embryonic and trophoblast stem cells.

The immune system has two broad components-innate and adaptive immunity. Adaptive immunity becomes established only after the onset of hematopoiesis, whereas the innate immune system may be actively protecting organisms from microbial invasion much earlier in development. Here, we address the question of whether the innate immune system functions in the early-stage embryo, i.

In vitro recapitulation of the urea cycle using murine embryonic stem cell-derived in vitro liver model.

Ammonia, a toxic metabolite, is converted to urea in hepatocytes via the urea cycle, a process necessary for cell/organismal survival. In liver, hepatocytes, polygonal and multipolar structures, have a few sides which face hepatic sinusoids and adjacent hepatocytes to form intercellular bile canaliculi connecting to the ductules. The critical nature of this three-dimensional environment should be related to the maintenance of hepatocyte function such as urea synthesis.

Hybrid sponge comprised of galactosylated chitosan and hyaluronic acid mediates the co-culture of hepatocytes and endothelial cells.

When constructing an in vitro model of liver tissue to mimic the in vivo liver microenvironment, the major challenge is to preserve and maintain the hepatocyte phenotype. The aim of this study was to develop a novel intelligent hybrid sponge for use in a dense co-culture system designed to simulate the liver microenvironment. We prepared a galactosylated chitosan (GCs)/hyaluronic acid (HA) hybrid sponge using a freeze-drying technique for the co-culture of primary hepatocytes and endothelial cells.