Downregulation of miR122 by grainyhead like-2 restricts the hepatocytic differentiation potential of adult liver progenitor cells.

肝臓の組織幹細胞は，肝細胞と胆管上皮細胞に分化可能な細胞である．我々は，転写因子 grainyhead like-2 が，microRNA122 の発現を抑制することによって，肝幹細胞の分化能を制御していることを明らかにした

Self-renewal capability of hepatocytic parental progenitor cells derived from adult rat liver is maintained long term when cultured on laminin 111 in serum-free medium

ラット小型肝細胞の前駆細胞は，Laminin(LN)111上で自己複製能と肝細胞としての基本機能を維持しながら継代培養可能であることがわかった．また，継代培養した前駆細胞はMatrigel積層培養で成熟化する

Transplantation of Thy1+ cells accelerates liver regeneration by enhancing the growth of small hepatocyte-like progenitor cells via IL17RB Signaling

障害肝から単離したThy1陽性細胞を，肝細胞の増殖を抑制した後に肝臓の2/3を部分切除したラット肝臓に移植すると，ドナー細胞が細胞外小胞を分泌し，レシピエント肝臓の内在性細胞に作用してサイトカインを分泌させることで，レシピエントに元々存在する肝前駆細胞の増殖を促進させ，肝再生を促進する，というメカニズムを解明しました

Hepatocytic parental progenitor cells of rat small hepatocytes maintain self-renewal capability after long-term culture

ラット小型肝細胞の前駆細胞は，長期培養後も自己複製能を維持し，肝細胞としての基本機能を維持していることがわかった．また，肝前駆細胞は生体内において肝細胞と胆管細胞への二分化能を有していることも示された

A Mathematical Model of Liver Cell Aggregation In Vitro

The behavior of mammalian cells within three-dimensional structures is an area of intense biological research and underpins the efforts of tissue engineers to regenerate human tissues for clinical applications. In the particular case of hepatocytes (liver cells), the formation of spheroidal multicellular aggregates has been shown to improve cell viability and functionality compared to traditional monolayer culture techniques. We propose a simple mathematical model for the early stages of this aggregation process, when cell clusters form on the surface of the extracellular matrix (ECM) layer on which they are seeded. We focus on interactions between the cells and the viscoelastic ECM substrate. Governing equations for the cells, culture medium, and ECM are derived using the principles of mass and momentum balance. The model is then reduced to a system of four partial differential equations, which are investigated analytically and numerically. The model predicts that provided cells are seeded at a suitable density, aggregates with clearly defined boundaries and a spatially uniform cell density on the interior will form. While the mechanical properties of the ECM do not appear to have a significant effect, strong cell-ECM interactions can inhibit, or possibly prevent, the formation of aggregates. The paper concludes with a discussion of our key findings and suggestions for future work

The severity of Puumala hantavirus induced nephropathia epidemica can be better evaluated using plasma interleukin-6 than C-reactive protein determinations

<p>Abstract</p> <p>Background</p> <p>Nephropathia epidemica (NE) is a Scandinavian type of hemorrhagic fever with renal syndrome caused by Puumala hantavirus. The clinical course of the disease varies greatly in severity. The aim of the present study was to evaluate whether plasma C-reactive protein (CRP) and interleukin (IL)-6 levels associate with the severity of NE.</p> <p>Methods</p> <p>A prospectively collected cohort of 118 consecutive hospital-treated patients with acute serologically confirmed NE was examined. Plasma IL-6, CRP, and creatinine, as well as blood cell count and daily urinary protein excretion were measured on three consecutive days after admission. Plasma IL-6 and CRP levels higher than the median were considered high.</p> <p>Results</p> <p>We found that high IL-6 associated with most variables reflecting the severity of the disease. When compared to patients with low IL-6, patients with high IL-6 had higher maximum blood leukocyte count (11.9 <it>vs </it>9.0 × 10⁹/l, <it>P </it>= 0.001) and urinary protein excretion (2.51 <it>vs </it>1.68 g/day, <it>P </it>= 0.017), as well as a lower minimum blood platelet count (55 <it>vs </it>80 × 10⁹/l, <it>P </it>< 0.001), hematocrit (0.34 <it>vs </it>0.38, <it>P </it>= 0.001), and urinary output (1040 <it>vs </it>2180 ml/day, <it>P </it>< 0.001). They also stayed longer in hospital than patients with low IL-6 (8 <it>vs </it>6 days, <it>P </it>< 0.001). In contrast, high CRP did not associate with severe disease.</p> <p>Conclusions</p> <p>High plasma IL-6 concentrations associate with a clinically severe acute Puumala hantavirus infection, whereas high plasma CRP as such does not reflect the severity of the disease.</p

Frequent loss of endothelin-3 (EDN3) expression due to epigenetic inactivation in human breast cancer

Introduction: Endothelin (EDN) signalling plays a crucial role in cell differentiation, proliferation and migration processes. There is compelling evidence that altered EDN signalling is involved in carcinogenesis by modulating cell survival and promoting invasiveness. To date, most reports have focused on the oncogenic potential of EDN1 and EDN2, both of which are overexpressed in various tumour entities. Here, we aimed at a first comprehensive analysis on EDN3 expression and its implication in human breast cancer. Methods: EDN3 mRNA expression was assessed by Northern blotting in normal human tissues (n = 9) as well as in matched pairs of normal and tumourous tissues from breast specimens (n = 50). EDN3 mRNA expression in breast cancer was further validated by real-time polymerase chain reaction (PCR) (n = 77). A tissue microarray was used to study EDN3 protein expression in breast carcinoma (n = 150) and normal breast epithelium (n = 44). EDN3 promoter methylation was analysed by methylation-specific PCR in breast cell lines (n = 6) before and after demethylating treatment, normal breast tissues (n = 17) and primary breast carcinomas (n = 128). EDN3 expression and methylation data were statistically correlated with clinical patient characteristics and patient outcome. Results: Loss of EDN3 mRNA expression in breast cancer, as initially detected by array-based expression profiling, could be confirmed by Northern blot analysis (> 2-fold loss in 96%) and real-time PCR (> 2-fold loss in 78%). Attenuated EDN3 expression in breast carcinoma was also evident at the protein level (45%) in association with adverse patient outcome in univariate (P = 0.022) and multivariate (hazard ratio 2.0; P = 0.025) analyses. Hypermethylation of the EDN3 promoter could be identified as the predominant mechanism leading to gene silencing. Reversion of the epigenetic lock by 5-aza-2'-deoxycytidine and trichostatin A resulted in EDN3 mRNA reexpression in vitro. Furthermore, EDN3 promoter hypermethylation was detected in 70% of primary breast carcinomas with significant association to loss of EDN3 mRNA expression (P = 0.005), whilst normal matched breast tissues revealed no EDN3 promoter methylation. Conclusions EDN3 is a frequent target of epigenetic inactivation in human breast cancer, potentially contributing to imbalanced EDN signalling commonly found in this disease. The clinical implication supports the view that EDN3, in contrast to EDN1 and EDN2, may act as natural tumour suppressor in the human mammary gland