The liver and exocrine pancreas share a common structure, with functioning units (hepatic plates and pancreatic acini) connected to the ductal tree. Here we show that Sox9 is expressed throughout the biliary and pancreatic ductal epithelia, which are connected to the intestinal stem-cell zone. Cre-based lineage tracing showed that adult intestinal cells, hepatocytes and pancreatic acinar cells are supplied physiologically from Sox9-expressing progenitors. Combination of lineage analysis and hepatic injury experiments showed involvement of Sox9-positive precursors in liver regeneration. Embryonic pancreatic Sox9-expressing cells differentiate into all types of mature cells, but their capacity for endocrine differentiation diminishes shortly after birth, when endocrine cells detach from the epithelial lining of the ducts and form the islets of Langerhans. We observed a developmental switch in the hepatic progenitor cell type from Sox9-negative to Sox9-positive progenitors as the biliary tree develops. These results suggest interdependence between the structure and homeostasis of endodermal organs, with Sox9 expression being linked to progenitor status.

The ex vivo generation of platelets from human-induced pluripotent cells (hiPSCs) is expected to compensate donor-dependent transfusion systems. However, manufacturing the clinically required number of platelets remains unachieved due to the low platelet release from hiPSC-derived megakaryocytes (hiPSC-MKs). Here, we report turbulence as a physical regulator in thrombopoiesis in vivo and its application to turbulence-controllable bioreactors. The identification of turbulent energy as a determinant parameter allowed scale-up to 8 L for the generation of 100 billion-order platelets from hiPSC-MKs, which satisfies clinical requirements. Turbulent flow promoted the release from megakaryocytes of IGFBP2, MIF, and Nardilysin to facilitate platelet shedding. hiPSC-platelets showed properties of bona fide human platelets, including circulation and hemostasis capacities upon transfusion in two animal models. This study provides a concept in which a coordinated physico-chemical mechanism promotes platelet biogenesis and an innovative strategy for ex vivo platelet manufacturing.

SummaryEpithelial cell contacts consist of not only bicellular contacts but also tricellular contacts, where the corners of three cells meet. At tricellular contacts, tight junctions (TJs) generate specialized structures termed tricellular TJs (tTJs) to seal the intercellular space. Tricellulin is the only known molecular component of tTJs and is involved in the formation of tTJs, as well as in the normal epithelial barrier function. However, the detailed molecular mechanism of how tTJs are formed and maintained remains elusive. Using a localization-based expression cloning method, we identified a novel tTJ-associated protein known as lipolysis-stimulated lipoprotein receptor (LSR). Upon LSR knockdown in epithelial cells, tTJ formation was affected and the epithelial barrier function was diminished. Tricellulin accumulation at the tricellular contacts was also diminished in these cells. By contrast, LSR still accumulated at the tricellular contacts upon tricellulin knockdown. Analyses of deletion mutants revealed that the cytoplasmic domain of LSR was responsible for the recruitment of tricellulin. On the basis of these observations, we propose that LSR defines tricellular contacts in epithelial cellular sheets by acting as a landmark to recruit tricellulin for tTJ formation.

Background: The discovery and development of novel biomarkers that could facilitate early diagnosis and thus prevent the progression of atherosclerosis-related diabetes mellitus (DM), cerebral infarction (CI), and cardiovascular disease (CVD) has garnered much research interest. Notably, recent reports have described a number of highly sensitive antibody markers. In this study, we aimed to identify additional antibody markers that would facilitate screening. Methods:The amplified luminescent proximity homogeneous assay (AlphaLISA) method, which incorporates glutathione-or streptavidin-donor beads and anti-human-IgG-acceptor beads, was used to evaluate serum antibody levels in serum samples. The protein array method was used for the initial screening, and peptide arrays were used to identify epitope sites. Results:The protein array identified SH3 domain-binding protein 5 (SH3BP5) as a target antigen of serum IgG antibodies in the sera of patients with atherosclerosis. We prepared recombinant glutathione S-transferase (GST)-fused SH3BP5 protein. Peptide arrays revealed that the epitope site recognized by serum antibodies is located within amino acids 161-174 of SH3BP5. AlphaLISA revealed significantly higher serum antibody levels against both the SH3BP5 protein and peptide in patients with DM, acute-phase CI, transient ischemic attack, CVD or chronic kidney disease (CKD), than in healthy donors. Furthermore, areas under the receiver operating characteristic curves of these antibodies were higher in patients with CKD and DM than in other patients. Spearman correlation analysis revealed associations between the serum antibody levels against SH3BP5 peptide and artery stenosis, hypertension, and smoking. Conclusions:The serum anti-SH3BP5 antibody marker appears to be useful for estimating the progress of atherosclerosis and may discriminate atherosclerosis associated with hypertension and/or habitual smoking.

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Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is found in cerebral neurons, and its expression is increased after hypoxic or ischemic injury, which also stimulates neurogenesis. To investigate the possible role of HB-EGF in hypoxic-ischemic induction of neurogenesis, we measured its expression, effects, and target receptors in embryonic murine cerebral cortical cultures and in adult rat brain. Hypoxia increased HB-EGF expression by approximately 50% in cortical cultures, where expression was associated with mature and immature neurons. HB-EGF (5-100 ng/ml) stimulated by approximately 80% the incorporation of bromodeoxyuridine (BrdU) into cultured cells that expressed the HB-EGF receptors epidermal growth factor receptor (EGFR)/avian erythroblastic leukemia viral oncogene homolog 1 (ErbB1) and N-arginine dibasic convertase (NRDc). Intracerebroventricular administration of HB-EGF in adult rats increased BrdU labeling in the subventricular zone and in the subgranular zone of dentate gyrus, where EGFR/ErbB1 and NRDc were also expressed and where ischemia-induced neurogenesis is observed. We conclude that HB-EGF stimulates neurogenesis in proliferative zones of the adult brain that are also affected in ischemia and that it does so by interacting with EGFR/ErbB1 and possibly NRDc. Therefore, HB-EGF may help to trigger proliferation of neuronal precursors in brain after hypoxic or ischemic injury.

A critical event in the early stages of atherosclerosis is the focal accumulation of lipid‐laden foam cells derived from macrophages. In various cholesterol‐fed animal models of atherosclerosis, localized attachment of circulating monocytes to arterial endothelial cells appeared to precede the formation of foam cells. It is suggested that monocyte recruitment into early lesions depends on the endothelial adhesiveness for monocytes and lymphocytes. In vivo and in vitro experiments have identified molecules, such as ICAM‐1, VCAM‐1, and P‐selectin, that can support the adhesion of monocytes and lymphocytes. Moreover, oxidized LDL, lysophosphatidyl‐choline, and oxidized fatty acids induce the expression not only of these adhesion molecules but also of scavenger receptors, such as CD‐36, SR‐A, and LOX‐1. Recently, we isolated and characterized the novel receptors for oxidized LDL, namely, LOX‐1 and SR‐PSOX. Expression of LOX‐1 is found on endothelial cells, smooth muscle cells, and macrophages, whereas SR‐PSOX is expressed on macrophages. In this paper the significance of oxidized LDL and its receptors, LOX‐1 and SR‐PSOX, in terms of atherogenesis is discussed.

AimsA significant increase in congestive heart failure (CHF) was reported when the anti-ErbB2 antibody trastuzumab was used in combination with the chemotherapy drug doxorubicin (Dox). The aim of the present study was to investigate the role(s) of miRNAs in acute Dox-induced cardiotoxicity.Methods and resultsNeuregulin-1-ErbB signalling is essential for maintaining adult cardiac function. We found a significant reduction in ErbB4 expression in the hearts of mice after Dox treatment. Because the proteasome pathway was only partially involved in the reduction of ErbB4 expression, we examined the involvement of microRNAs (miRs) in the reduction of ErbB4 expression. miR-146a was shown to be up-regulated by Dox in neonatal rat cardiac myocytes. Using a luciferase reporter assay and overexpression of miR-146a, we confirmed that miR-146a targets the ErbB4 3′UTR. After Dox treatment, overexpression of miR-146a, as well as that of siRNA against ErbB4, induced cell death in cardiomyocytes. Re-expression of ErbB4 in miR-146a-overexpressing cardiomyocytes ameliorated Dox-induced cell death. To examine the loss of miR-146a function, we constructed ‘decoy’ genes that had tandem complementary sequences for miR-146a in the 3′UTR of a luciferase gene. When miR-146a ‘decoy’ genes were introduced into cardiomyocytes, ErbB4 expression was up-regulated and Dox-induced cell death was reduced.ConclusionThese findings suggested that the up-regulation of miR-146a after Dox treatment is involved in acute Dox-induced cardiotoxicity by targeting ErbB4. Inhibition of both ErbB2 and ErbB4 signalling may be one of the reasons why those patients who receive concurrent therapy with Dox and trastuzumab suffer from CHF.