Hypoxia-enhanced Blood-Brain Barrier Chip recapitulates human barrier function and shuttling of drugs and antibodies

The high selectivity of the human blood-brain barrier (BBB) restricts delivery of many pharmaceuticals and therapeutic antibodies to the central nervous system. Here, we describe an in vitro microfluidic organ-on-a-chip BBB model lined by induced pluripotent stem cell-derived human brain microvascular endothelium interfaced with primary human brain astrocytes and pericytes that recapitulates the high level of barrier function of the in vivo human BBB for at least one week in culture. The endothelium expresses high levels of tight junction proteins and functional efflux pumps, and it displays selective transcytosis of peptides and antibodies previously observed in vivo. Increased barrier functionality was accomplished using a developmentally-inspired induction protocol that includes a period of differentiation under hypoxic conditions. This enhanced BBB Chip may therefore represent a new in vitro tool for development and validation of delivery systems that transport drugs and therapeutic antibodies across the human BBB

Gliadin Peptide P31-43 Localises to Endocytic Vesicles and Interferes with Their Maturation

BACKGROUND: Celiac Disease (CD) is both a frequent disease (1:100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called "toxic" A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles. METHODS/PRINCIPAL FINDINGS: Both P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy. CONCLUSIONS: P31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosine Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies

Identification of functional dopamine receptors in human tetratocarcinoma NT2 cells.: Mol.Brain Res.

NRC publication: Ye

Morphology, growth, and gene expression in five newly isolated murine hepatocellular tumor cell lines

Five murine hepatocellular tumor cell lines (HepM-1-5) were isolated and grown in a synthetic medium added with hormones, growth factors and/or serum. The morphology of these lines ranged from a nearly homogeneous epithelial-like shape (HepM-2) to a stromal appearance (HepM-1). The remaining lines displayed a mixed morphology. For their proliferation all of the cell lines retained a clear dependence on the extracellular calcium level and hormonal and/or serum growth factors and, rather homogeneously, they did not express the albumin, alpha-fetoprotein (with the exception of HepM-2 cells), tyrosine aminotransferase, and ornithine transcarbamylase genes, whereas they all exhibited discrete levels of the ornithine aminotransferase mRNA. Only HepM-3 and HepM-5 lines expressed the procollagen type I gene

Humoral immune response to tissue transglutaminase is related to epithelial cell proliferation in celiac disease

Tissue transglutaminase (tTG) autoantibodies are markers of celiac disease, and the enzyme is required for several crucial biological processes. The aim of this study was to determine whether these autoantibodies are involved in the pathogenesis of the mucosal lesion typical of celiac diseas

Efficacy of TENS in cervical pain syndromes: an umbrella review of systematic reviews

Neck pain is defined as perceived pain, originating in an area bounded above by the nuchal line, below by an imaginary line passing through the spinous process of T1 and laterally by the sagittal plane tangent to the lateral edges of the neck. Our purpose is to investigate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in patients suffering from both acute and chronic cervical pain syndromes. The literature research was conducted by consulting the following databases: PubMed, PEDro, Cochrane, and Google Scholar. To formulate the scientific question correctly, the PICO model was used. This umbrella review includes all systematic reviews with or without meta-analysis, in English, which analyze the use of TENS in subjects suffering from acute or chronic cervical pain. To evaluate the methodological quality of the studies, the AMSTAR model. A total of eleven systematic reviews with or without meta-analyses were included. The results of the study show how TENS seems to have an effect in reducing the intensity of acute and chronic cervical pain, especially in the short term. However, it was not possible to provide precise recommendations in this regard. Based on our result, it is desirable to carry out further studies that support the effectiveness of using TENS in patients suffering from acute and chronic neck pain

Mapping the initial DNA breaks in apoptotic jurkat cells using ligation mediated PCR

In press: YesNRC publication: Ye

Coffee reduces liver damage in a rat model of steatohepatitis: the underlying mechanisms and the role of polyphenols and melanoidins

Epidemiological data associate coffee consumption with a lower prevalence of chronic liver disease and a reduced risk of elevated liver enzyme levels (gamma glutamyl transpeptidase and alanine aminotransferase), advanced liver disease and its complications, and hepatocellular carcinoma. Knowledge of the mechanisms underlying these effects and the coffee components responsible for these properties is still lacking. In this study, 1.5 mL/day of decaffeinated coffee or its polyphenols or melanoidins (corresponding to approximately 2 cups of filtered coffee or 6 cups of espresso coffee for a 70-kg person) were added for 8 weeks to the drinking water of rats who were being fed a high-fat, high-calorie solid diet (HFD) for the previous 4 weeks. At week 12, HFD + water rats showed a clinical picture typical of advanced nonalcoholic steatohepatitis compared with control rats (normal diet + water). In comparison, HFD + coffee rats showed: (1) reduced hepatic fat and collagen, as well as reduced serum alanine aminotransferase and triglycerides; (2) a two-fold reduced/oxidized glutathione ratio in both serum and liver; (3) reduced serum malondialdehyde (lipid peroxidation) and increased ferric reducing antioxidant power (reducing activity); (4) reduced expression of tumor necrosis factor alpha (TNF-alpha), tissue transglutaminase, and transforming growth factor beta and increased expression of adiponectin receptor and peroxisome proliferator-activated receptor alpha in liver tissue; and (5) reduced hepatic concentrations of proinflammatory TNF-alpha and interferon-gamma and increased anti-inflammatory interleukin-4 and interleukin-10. Conclusion: Our data demonstrate that coffee consumption protects the liver from damage caused by a high-fat diet. This effect was mediated by a reduction in hepatic fat accumulation (through increased fatty acid beta-oxidation); systemic and liver oxidative stress (through the glutathione system); liver inflammation (through modulation of genes); and expression and concentrations of proteins and cytokines related to inflammation