Human PSC-derived liver cells and their applications for disease models and drug discovery.

The liver comprises hepatic parenchymal cells, primarily hepatocytes, and non-parenchymal cells such as liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs), and cholangiocytes. These cell types interact with each other to maintain homeostasis through metabolism, detoxification, and protein synthesis. Such cellular interactions also play crucial roles in regulating the onset and progression of liver diseases.

Local keratinocyte-nociceptor interactions enhance obesity-mediated painful small fiber neuropathy via NGF-TrkA-PI3K signaling axis.

The pathology of painful small fiber neuropathy, characterized by neuropathic pain and axon degeneration, develops locally within the skin during the stages of obesity and pre-diabetes. However, the initiation and progression of morphological and functional abnormalities in skin sensory nerves remains elusive. We evaluated pain-associated wiping behavior and conducted live Ca imaging of the diet-induced obesity (DIO) ear skin to detect sensory hypersensitivity.

Local keratinocyte-nociceptor interactions enhance obesity-mediated small fiber neuropathy via NGF-TrkA-PI3K signaling axis.

The pathology of diabetic small fiber neuropathy, characterized by neuropathic pain and axon degeneration, develops locally within the skin during the stages of obesity and pre-diabetes. However, the initiation and progression of morphological and functional abnormalities in skin sensory nerves remains elusive. To address this, we utilized ear skin from mice with diet-induced obesity (DIO), the mouse models for obesity and pre-type 2 diabetes.

Establishment of human induced pluripotent stem cell-derived hepatobiliary organoid with bile duct for pharmaceutical research use.

In vitro models of the human liver are promising alternatives to animal tests for drug development. Currently, primary human hepatocytes (PHHs) are preferred for pharmacokinetic and cytotoxicity tests. However, they are unable to recapitulate the flow of bile in hepatobiliary clearance owing to the lack of bile ducts, leading to the limitation of bile analysis.

Using human induced pluripotent stem cell-derived liver cells to investigate the mechanisms of liver fibrosis in vitro.

The liver is a highly organized organ that consists of hepatic parenchymal cells, hepatocytes, and non-parenchymal cells such as the liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs), cholangiocytes, and Kupffer cells. Although previous studies have primarily focused on the hepatocyte dynamics in the injured liver, recent studies have shown that non-parenchymal cells play an essential role in both liver regeneration and liver fibrosis progression. Among the non-parenchymal cells, HSCs directly contribute to the progression of liver fibrosis because the activation of HSCs in response to liver injury or inflammation results in the excess production of extra cellular matrix.

Hepatic leukemia factor-expressing paraxial mesoderm cells contribute to the developing brain vasculature.

Recent genetic lineage tracing studies reveal heterogeneous origins of vascular endothelial cells and pericytes in the developing brain vasculature, despite classical experimental evidence for a mesodermal origin. Here we provide evidence through a genetic lineage tracing experiment that cephalic paraxial mesodermal cells give rise to endothelial cells and pericytes in the developing mouse brain. We show that Hepatic leukemia factor (Hlf) is transiently expressed by cephalic paraxial mesenchyme at embryonic day (E) 8.

Development of human iPSC-derived quiescent hepatic stellate cell-like cells for drug discovery and in vitro disease modeling.

Hepatic stellate cells (HSCs) play a central role in the progression of liver fibrosis by producing extracellular matrices. The development of drugs to suppress liver fibrosis has been hampered by the lack of human quiescent HSCs (qHSCs) and an appropriate in vitro model that faithfully recapitulates HSC activation. In the present study, we developed a culture system to generate qHSC-like cells from human-induced pluripotent stem cells (hiPSCs) that can be converted into activated HSCs in culture.

Small extracellular vesicles derived from interferon-γ pre-conditioned mesenchymal stromal cells effectively treat liver fibrosis.

Mesenchymal stromal cells (MSCs) are used for ameliorating liver fibrosis and aiding liver regeneration after cirrhosis; Here, we analyzed the therapeutic potential of small extracellular vesicles (sEVs) derived from interferon-γ (IFN-γ) pre-conditioned MSCs (γ-sEVs). γ-sEVs effectively induced anti-inflammatory macrophages with high motility and phagocytic abilities in vitro, while not preventing hepatic stellate cell (HSC; the major source of collagen fiber) activation in vitro. The proteome analysis of MSC-derived sEVs revealed anti-inflammatory macrophage inducible proteins (e.

Modulation of hepatitis B virus infection by epidermal growth factor secreted from liver sinusoidal endothelial cells.

Hepatocytes derived from human iPSCs are useful to study hepatitis B virus (HBV) infection, however infection efficiency is rather poor. In order to improve the efficiency of HBV infection to iPSC-derived hepatocytes, we set a co-culture of hepatocytes with liver non-parenchymal cells and found that liver sinusoidal endothelial cells (LSECs) enhanced HBV infection by secreting epidermal growth factor (EGF). While EGF receptor (EGFR) is known as a co-receptor for HBV, we found that EGF enhanced HBV infection at a low dose of EGF, whereas EGF at a high dose suppressed HBV infection.

Transcriptome profiling of hiPSC-derived LSECs with nanoCAGE.

Liver Sinusoidal Endothelial Cells (LSECs) are an important component of the liver as they compose the microvasculature which allows the supply of oxygen, blood, and nutrients. However, maintenance of these cells in vitro remains challenging as they tend to rapidly lose some of their characteristics such as fenestration or as their immortalized counterparts present poor characteristics. In this work, human induced pluripotent stem cells (hiPSCs) have been differentiated toward an LSEC phenotype.

Induction of Functional Hepatocytes from Human iPSCs.

Human-induced pluripotent stem cells (iPSCs) could be a useful source for production of hepatocytes. Here, we develop protocols to generate iPSC-derived liver progenitor cells, liver sinusoidal endothelial cells (LSECs), and hepatic stellate cells (HSCs). We also establish long-term two-dimensional co-culture system to induce functional hepatocytes from iPSC-derived liver cells.

An In Vitro Human Liver Model by iPSC-Derived Parenchymal and Non-parenchymal Cells.

During liver development, hepatoblasts and liver non-parenchymal cells (NPCs) such as liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs) constitute the liver bud where they proliferate and differentiate. Accordingly, we reasoned that liver NPCs would support the maturation of hepatocytes derived from human induced pluripotent stem cells (hiPSCs), which usually exhibit limited functions. We found that the transforming growth factor β and Rho signaling pathways, respectively, regulated the proliferation and maturation of LSEC and HSC progenitors isolated from mouse fetal livers.

CPM Is a Useful Cell Surface Marker to Isolate Expandable Bi-Potential Liver Progenitor Cells Derived from Human iPS Cells.

To develop a culture system for large-scale production of mature hepatocytes, liver progenitor cells (LPCs) with a high proliferation potential would be advantageous. We have found that carboxypeptidase M (CPM) is highly expressed in embryonic LPCs, hepatoblasts, while its expression is decreased along with hepatic maturation. Consistently, CPM expression was transiently induced during hepatic specification from human-induced pluripotent stem cells (hiPSCs).