Evaluation of induced pluripotent stem cell differentiation into neural progenitor cell using Raman spectra derived from extracellular vesicles in culture supernatants.

Non-invasive cell culture monitoring technology is crucial to improve the manufacturing efficiency of cell products. We have found that extracellular vesicles (EVs) are secreted into the culture supernatants in the differentiation process from human induced pluripotent stem cells (iPSCs) to dopaminergic progenitor cells, and that the composition of EVs changes in accordance with the differentiation processes. In this study, we hypothesized that it is possible to evaluate the cultured cellular states by detecting compositional changes of EVs secreted from cultured cells with label-free Raman spectroscopy in a non-invasive manner.

Hepatocytes differentiate into intestinal epithelial cells through a hybrid epithelial/mesenchymal cell state in culture.

Hepatocytes play important roles in the liver, but in culture, they immediately lose function and dedifferentiate into progenitor-like cells. Although this unique feature is well-known, the dynamics and mechanisms of hepatocyte dedifferentiation and the differentiation potential of dedifferentiated hepatocytes (dediHeps) require further investigation. Here, we employ a culture system specifically established for hepatic progenitor cells to study hepatocyte dedifferentiation.

Direct Conversion of Human Endothelial Cells Into Liver Cancer-Forming Cells Using Nonintegrative Episomal Vectors.

Liver cancer is an aggressive cancer associated with a poor prognosis. Development of therapeutic strategies for liver cancer requires fundamental research using suitable experimental models. Recent progress in direct reprogramming technology has enabled the generation of many types of cells that are difficult to obtain and provide a cellular resource in experimental models of human diseases.

Analysis of extracellular vesicles as a potential index for monitoring differentiation of neural lineage cells from induced pluripotent stem cells.

To improve cell production efficacy, it is important to evaluate cell conditions during culture. Extracellular vesicles (EVs) secreted from various cells are involved in stem cell differentiation. As EVs carry information about their source cells, we hypothesized that they may serve as a noninvasive index of cell conditions.

Direct reprogramming of human umbilical vein- and peripheral blood-derived endothelial cells into hepatic progenitor cells.

Recent advances have enabled the direct induction of human tissue-specific stem and progenitor cells from differentiated somatic cells. However, it is not known whether human hepatic progenitor cells (hHepPCs) can be generated from other cell types by direct lineage reprogramming with defined transcription factors. Here, we show that a set of three transcription factors, FOXA3, HNF1A, and HNF6, can induce human umbilical vein endothelial cells to directly acquire the properties of hHepPCs.

The Dynamics of Transcriptional Activation by Hepatic Reprogramming Factors.

Specific combinations of two transcription factors (Hnf4α plus Foxa1, Foxa2, or Foxa3) can induce direct conversion of mouse fibroblasts into hepatocyte-like cells. However, the molecular mechanisms underlying hepatic reprogramming are largely unknown. Here, we show that the Foxa protein family members and Hnf4α sequentially and cooperatively bind to chromatin to activate liver-specific gene expression.

Generation of Nanog reporter mice that distinguish pluripotent stem cells from unipotent primordial germ cells.

Nanog is a core transcription factor specifically expressed not only in the pluripotent stem cells (PSCs), such as embryonic stem cells (ESCs), embryonic germ cells (EGCs), and induced PSCs (iPSCs), but also in the unipotent primordial germ cells (PGCs). Although Nanog promoter/enhancer regions are well characterized by in vitro analyses, direct correlations between the regulatory elements for Nanog expression and in vivo expression patterns of Nanog have not been fully clarified. In this study, we generated Nanog-RFP transgenic (Tg) mice in which expression of red fluorescent protein (RFP) is driven by a 5.

Cell Aggregation Culture Induces Functional Differentiation of Induced Hepatocyte-like Cells through Activation of Hippo Signaling.

Recent progress in direct lineage reprogramming has enabled the generation of induced hepatocyte-like (iHep) cells and revealed their potential as an alternative to hepatocytes for medical applications. However, the hepatic functions of iHep cells are insufficient compared with those of primary hepatocytes. Here, we show that cell-aggregate formation can rapidly induce growth arrest and hepatic maturation of iHep cells through activation of Hippo signaling.

Myofibroblasts Derived from Hepatic Progenitor Cells Create the Tumor Microenvironment.

Hepatic progenitor cells (HPCs) appear in response to several types of chronic injury in the human and rodent liver that often develop into liver fibrosis, cirrhosis, and primary liver cancers. However, the contribution of HPCs to the pathogenesis and progression of such liver diseases remains controversial. HPCs are generally defined as cells that can differentiate into hepatocytes and cholangiocytes.

Kupffer cells induce Notch-mediated hepatocyte conversion in a common mouse model of intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is a malignant epithelial neoplasm composed of cells resembling cholangiocytes that line the intrahepatic bile ducts in portal areas of the hepatic lobule. Although ICC has been defined as a tumor arising from cholangiocyte transformation, recent evidence from genetic lineage-tracing experiments has indicated that hepatocytes can be a cellular origin of ICC by directly changing their fate to that of biliary lineage cells. Notch signaling has been identified as an essential factor for hepatocyte conversion into biliary lineage cells at the onset of ICC.

Hepatocytes, rather than cholangiocytes, can be the major source of primitive ductules in the chronically injured mouse liver.

The proliferation of biliary lineage cells in chronic liver diseases, which leads to formation of primitive ductules in portal areas of the hepatic lobule, may be important not only for liver regeneration, but also for initiation of liver cancer. Thus, understanding how these primitive ductular cells emerge and proliferate in chronically injured liver holds promise for development of therapeutic strategies for liver diseases. However, the origin of these primitive ductular cells remains controversial.

Intrahepatic cholangiocarcinoma can arise from Notch-mediated conversion of hepatocytes.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignancy in the liver. ICC has been classified as a malignant tumor arising from cholangiocytes; however, the co-occurrence of ICC and viral hepatitis suggests that ICC originates in hepatocytes. In order to determine the cellular origin of ICC, we used a mouse model of ICC in which hepatocytes and cholangiocytes were labeled with heritable, cell type–specific reporters.

Direct conversion of mouse fibroblasts to hepatocyte-like cells by defined factors.

The location and timing of cellular differentiation must be stringently controlled for proper organ formation. Normally, hepatocytes differentiate from hepatic progenitor cells to form the liver during development. However, previous studies have shown that the hepatic program can also be activated in non-hepatic lineage cells after exposure to particular stimuli or fusion with hepatocytes.

Glycogen synthase kinase 3 β-dependent Snail degradation directs hepatocyte proliferation in normal liver regeneration.

Liver regeneration proceeds under the well-orchestrated control of multiple transcription factors that lead hepatocytes to reenter the cell cycle, proliferate, and renew quiescence. Here, we found an important role of the zinc-finger transcription factor Snail in liver regeneration. Snail was typically expressed in quiescent adult hepatocytes, but was rapidly degraded when the liver needed to regenerate itself.

EGF signaling activates proliferation and blocks apoptosis of mouse and human intestinal stem/progenitor cells in long-term monolayer cell culture.

The homeostatic renewal of the intestinal epithelium depends on regulation of proliferation and differentiation of stem/progenitor cells residing in a specific site, called the 'stem cell niche.' Thus, the reconstitution of the microenvironment of the stem cell niche may allow us to maintain intestinal stem/progenitor cells in culture for a longer period. Although epidermal growth factor (EGF) is conventionally used as a supplement of intestinal epithelial cell culture, little has been known regarding a role of EGF signaling in a stem/progenitor cell population.

Flow cytometric isolation and clonal identification of self-renewing bipotent hepatic progenitor cells in adult mouse liver.

Unlabelled: The adult liver progenitor cells appear in response to several types of pathological liver injury, especially when hepatocyte replication is blocked. These cells are histologically identified as cells that express cholangiocyte markers and proliferate in the portal area of the hepatic lobule. Although these cells play an important role in liver regeneration, the precise characterization that determines these cells as self-renewing bipotent primitive hepatic cells remains to be shown.

Tbx3 controls the fate of hepatic progenitor cells in liver development by suppressing p19ARF expression.

Although the T-box family of transcription factors function in many different tissues, their role in liver development is unknown. Here we show that Tbx3, the T-box gene that is mutated in human ulnar-mammary syndrome, is specifically expressed in multipotent hepatic progenitor cells, ;hepatoblasts', isolated from the developing mouse liver. Tbx3-deficient hepatoblasts presented severe defects in proliferation as well as uncontrollable hepatobiliary lineage segregation, including the promotion of cholangiocyte (biliary epithelial cell) differentiation, which thereby caused abnormal liver development.

ABCA5 resides in lysosomes, and ABCA5 knockout mice develop lysosomal disease-like symptoms.

ABCA5 is a member of the ABC transporter A subfamily, and a mouse orthologue (mABCA5) in newborn mouse brain and neural cells was identified by reverse transcription-PCR. Full-length cDNA cloning revealed that mABCA5 consists of 1,642 amino acid residues and that its putative structure is that of a full-type ABC transporter having two sets of six transmembrane segments and a nucleotide binding domain. Immunohistochemical studies revealed that mABCA5 is expressed in brain, lung, heart, and thyroid gland.

Cyclization of aryl acyl radicals generated from S-(4-cyano)phenyl thiolesters by a nickel complex catalyzed electroreduction.

Aromatic acyl radicals generated from S-(4-cyano)phenyl 2-alkenylthiobenzoate by a nickel complex catalyzed electroreduction undergo 5- and 6-exo cyclization to give 1-indanone and dihydro-1-naphthalenone derivatives, respectively.