No abstract

Progenitor cell-derived hepatocytes are critical for hepatocyte replenishment. Therefore, we established a line of human hepatic progenitor (HNK1) cells and determined their biological characteristics for experimental and therapeutic applications. HNK1 cells, isolated from human noncirrhotic liver samples with septal fibrosis, showed high expression of the hepatic progenitor cell (HPC) markers EpCAM, CK7, CK19, alpha-fetoprotein (AFP), CD90 (Thy1), and EFNA1. Expression of CD133 was very low. Ductular reactions at the periphery of cirrhotic nodules were immunohistochemically positive for these HPC markers, including EFNA1. Sodium butyrate, a differentiation inducer, induced hepatocyte-like morphological changes in HNK1 cells. It resulted in down-regulation of the hepatic progenitor cell markers EpCAM, CK7, CK19, AFP, and EFNA1 and up-regulation of mature hepatocyte markers, including albumin, CK8, and CK18. Furthermore, sodium butyrate treatment and a serial passage of HNK1 cells resulted in enhanced albumin secretion, ureagenesis, and CYP enzyme activity, all of which are indicators of differentiation in hepatocytes. However, HNK1 cells at passage 50 did not exhibit anchorage-independent growth capability and caused no tumors in immunodeficient mice, suggesting that they had no spontaneous malignant transformation ability. From this evidence, HNK1 cells were found to be EpCAM(+)/CD133(-) hepatic progenitor cells without spontaneous malignant transformation ability. We therefore conclude that HNK1 cells could be useful for experimental and therapeutic applications.

Creatine is a nitrogenous organic acid known to function in adenosine triphosphate (ATP) metabolism. Recent evidence indicates that creatine regulates the differentiation of mesenchymal stem cells (MSCs) in processes such as osteogenesis and myogenesis. In this study, we show that creatine also has a negative regulatory effect on fat cell formation. Creatine inhibits the accumulation of cytoplasmic triglycerides in a dose-dependent manner irrespective of the adipogenic cell models used, including a C3H10T1/2 MSC line, 3T3-L1 preadipocytes, and primary human MSCs. Consistently, a dramatic reduction in mRNA expression of adipogenic transcription factors, peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), glucose transporters, 1 and 4 (Glut1, Glut4), and adipocyte markers, aP2 and adipsin, was observed in the presence of creatine. Creatine appears to exert its inhibitory effects on adipogenesis during early differentiation, but not late differentiation, or proliferation stages through inhibition of the PI3K-Akt-PPARγ signaling pathway. In an in vivo model, administration of creatine into mice resulted in body mass increase without fat accumulation. In summary, our results indicate that creatine downregulates adipogenesis through inhibition of phosphatidylinositol 3-kinase (PI3K) activation and imply the potent therapeutic value of creatine in treating obesity and obesity-related metabolic disorders.

Notch has a broad range of regulatory functions in many developmental processes, including hematopoiesis, neurogenesis, and angiogenesis. Notch has several key functional regions such as the RBP-Jκ/CBF1 association module (RAM) domain, nuclear localization signals (NLS), and ankyrin (ANK) repeats. However, previous reports assessing the level of importance of these domains in the Notch signaling pathway are controversial. In this study, we have assessed the level of contribution of each Notch domain to the regulation of mammalian neural stem cells in vivo as well as in vitro. Reporter assays and real-time polymerase chain reactions show that the ANK repeats and RAM domain are indispensable to the transactivation of Notch target genes, whereas a nuclear export signal (NES)-fused Notch intracellular domain (NICD) mutant defective in nuclear localization exerts a level of activity comparable to unmodified NICD. Transactivational ability appears to be tightly coupled to Notch functions during brain development. Unlike ANK repeats and RAM domain deletion mutants, NES-NICD recapitulates NICD features such as promotion of astrogenesis at the expense of neurogenesis in vitro and enhancement of neural stem cell character in vivo. Our data support the previous observation that intranuclear localization is not essential to the oncogenesis of Notch1 in certain types of cells and imply the importance of the noncanonical Notch signaling pathway in the regulation of mammalian neural stem cells.

Background: The platelet-to-white blood cell ratio (PWR) is a hematologic marker of the systemic inflammatory response. Recently, the PWR was revealed to have a role as an independent prognostic factor for mortality in patients with hepatitis B virus (HBV)-related acute-on-chronic failure (ACLF) and HBV-related liver cirrhosis (LC) with acute decompensation (AD). However, the prognostic role of the PWR still needs to be investigated in LC patients with AD. In this study, we analyzed whether the PWR could stratify the risk of adverse outcomes (death or liver transplantation (LT)) in these patients. Methods: A prospective cohort of 1670 patients with AD of liver cirrhosis ((age: 55.2 ± 7.8, male = 1226 (73.4%)) was enrolled and evaluated for 28-day and overall adverse outcomes. Results: During a median follow-up of 8.0 months (range, 1.9–15.5 months), 424 (25.4%) patients had adverse outcomes (death = 377, LT = 47). The most common etiology of LC was alcohol use (69.7%). The adverse outcome rate was higher for patients with a PWR ≤ 12.1 than for those with a PWR > 12.1. A lower PWR level was a prognostic factor for 28-day adverse outcomes (PWR: hazard ratio 1.707, p = 0.034) when adjusted for the etiology of cirrhosis, infection, ACLF, and the MELD score. In the subgroup analysis, the PWR level stratified the risk of 28-day adverse outcomes regardless of the presence of ACLF or the main form of AD but not for those with bacterial infection. Conclusions: A lower PWR level was associated with 28-day adverse outcomes, indicating that the PWR level can be a useful and simple tool for stratifying the risk of 28-day adverse outcomes in LC patients with AD.