Longitudinal Assessment of Cytokine Expression and Plasminogen Activation in Hantavirus Cardiopulmonary Syndrome Reveals Immune Regulatory Dysfunction in End-Stage Disease.

Pathogenic New World orthohantaviruses cause hantavirus cardiopulmonary syndrome (HCPS), a severe immunopathogenic disease in humans manifested by pulmonary edema and respiratory distress, with case fatality rates approaching 40%. High levels of inflammatory mediators are present in the lungs and systemic circulation of HCPS patients. Previous studies have provided insights into the pathophysiology of HCPS. However, the longitudinal correlations of innate and adaptive immune responses and disease outcomes remain unresolved. This study analyzed serial immune responses in 13 HCPS cases due to Sin Nombre orthohantavirus (SNV), with 11 severe cases requiring extracorporeal membrane oxygenation (ECMO) treatment and two mild cases. We measured viral load, levels of various cytokines, urokinase plasminogen activator (uPA), and plasminogen activator inhibitor-1 (PAI-1). We found significantly elevated levels of proinflammatory cytokines and PAI-1 in five end-stage cases. There was no difference between the expression of active uPA in survivors' and decedents' cases. However, total uPA in decedents' cases was significantly higher compared to survivors'. In some end-stage cases, uPA was refractory to PAI-1 inhibition as measured by zymography, where uPA and PAI-1 were strongly correlated to lymphocyte counts and IFN-γ. We also found bacterial co-infection influencing the etiology and outcome of immune response in two cases. Unsupervised Principal Component Analysis and hierarchical cluster analyses resolved separate waves of correlated immune mediators expressed in one case patient due to a sequential co-infection of bacteria and SNV. Overall, a robust proinflammatory immune response, characterized by an imbalance in T helper 17 (Th17) and regulatory T-cells (Treg) subsets, was correlated with dysregulated inflammation and mortality. Our sample size is small; however, the core differences correlated to survivors and end-stage HCPS are instructive.

Effects of Acute and Chronic Exposure to Residual Level Erythromycin on Human Intestinal Epithelium Cell Permeability and Cytotoxicity.

Residual concentrations of erythromycin in food could result in gastrointestinal tract exposure that potentially poses a health-hazard to the consumer, affecting intestinal epithelial permeability, barrier function, microbiota composition, and antimicrobial resistance. We investigated the effects of erythromycin after acute (48 h single treatment with 0.03 µg/mL to 300 µg/mL) or chronic (repeated treatment with 0.3 µg/mL and 300 µg/mL erythromycin for five days) exposures on the permeability of human colonic epithelial cells, a model that mimics a susceptible intestinal surface devoid of commensal microbiota. Transepithelial electrical resistance (TER) measurements indicated that erythromycin above 0.3 µg/mL may compromise the epithelial barrier. Acute exposure increased cytotoxicity, while chronic exposure decreased the cytotoxicity. Quantitative PCR analysis revealed that only ICAM1 (intercellular adhesion molecule 1) was up-regulated during 0.3 µg/mL acute-exposure, while ICAM1, JAM3 (junctional adhesion molecule 3), and ITGA8 (integrin alpha 8), were over-expressed in the 300 µg/mL acute treatment group. However, during chronic exposure, no change in the mRNA expression was observed at 0.3 µg/mL, and only ICAM2 was significantly up-regulated after 300 µg/mL. ICAM1 and ICAM2 are known to be involved in the formation of extracellular matrices. These gene expression changes may be related to the immunoregulatory activity of erythromycin, or a compensatory mechanism of the epithelial cells to overcome the distress caused by erythromycin due to increased permeability.

Dose-Dependent Effects of Aloin on the Intestinal Bacterial Community Structure, Short Chain Fatty Acids Metabolism and Intestinal Epithelial Cell Permeability.

Aloe leaf or purified aloin products possess numerous therapeutic and pharmaceutical properties. It is widely used as ingredients in a variety of food, cosmetic and pharmaceutical products. Animal studies have shown that consumption of aloe or purified aloin cause intestinal goblet cell hyperplasia, and malignancy. Here, we tested antibacterial effects of aloin, against intestinal commensal microbiota. Minimum inhibitory concentration of aloin for several human commensal bacterial species (Gram-positive and Gram-negative) ranged from 1 to 4 mg/ml. Metabolism studies indicated that Enterococcus faecium was capable of degrading aloin into aloe-emodin at a slower-rate compared to Eubacterium spp. As a proof of concept, we incubated 3% rat fecal-slurry (an in vitro model to simulate human colon content) with 0.5, 1, and 2 mg/ml of aloin to test antimicrobial properties. Low aloin concentrations showed minor perturbations to intestinal bacteria, whereas high concentration increased Lactobacillus sp. counts. Aloin also decreased butyrate-production in fecal microbiota in a dose-dependent manner after 24 h exposure. The 16S rRNA sequence-data revealed that aloin decreases the abundance of butyrate-producing bacterial species. Transepithelial resistant result revealed that aloin alters the intestinal barrier-function at higher concentrations (500 µM). In conclusion, aloin exhibits antibacterial property for certain commensal bacteria and decreases butyrate-production in a dose -dependent manner. HIGHLIGHTS     -Aloin exhibits antibacterial properties for certain intestinal commensal bacteria.     -In rat fecal slurry (an in vitro model to simulate human colon content), longer aloin exposure (24 h) decreases the butyrate production in dose dependent manner.     -The 16s rRNA sequencing data show that aloin decreased the abundance of butyrate producing bacterial species.     -Rat intestinal commensal bacteria metabolized aloin into aloe-emodin.     -Aloin altered the intestinal epithelial cells barrier integrity, however, the metabolic product of aloin - Aloe-emodin did not alter epithelial cells permeability.

Engineering and monitoring cellular barrier models.

Epithelia and endothelia delineate tissue compartments and control their environments by regulating the passage of ions and solutes. This barrier function is essential for the development and maintenance of multicellular organisms, and its dysfunction is associated with numerous human diseases. Recent advances in biomaterials and microfabrication technologies have evolved in vitro approaches for modelling biological barriers. Current microphysiological systems have become more efficient and reliable in mimicking the cell microenvironment. Additionally, methods for the quantification of barrier permeability have long provided significant insight into their underlying mechanisms. In this review, we outline the current techniques to quantify the barrier function of engineered tissues, and we also give an overview of recent microphysiological systems of biological barriers that emulate the microenvironment and microarchitecture of native tissues.

Inflammatory Responses and Barrier Function of Endothelial Cells Derived from Human Induced Pluripotent Stem Cells.

Several studies have reported endothelial cell (EC) derivation from human induced pluripotent stem cells (hiPSCs). However, few have explored their functional properties in depth with respect to line-to-line and batch-to-batch variability and how they relate to primary ECs. We therefore carried out accurate characterization of hiPSC-derived ECs (hiPSC-ECs) from multiple (non-integrating) hiPSC lines and compared them with primary ECs in various functional assays, which included barrier function using real-time impedance spectroscopy with an integrated assay of electric wound healing, endothelia-leukocyte interaction under physiological flow to mimic inflammation and angiogenic responses in in vitro and in vivo assays. Overall, we found many similarities but also some important differences between hiPSC-derived and primary ECs. Assessment of vasculogenic responses in vivo showed little difference between primary ECs and hiPSC-ECs with regard to functional blood vessel formation, which may be important in future regenerative medicine applications requiring vascularization.

Effects of residual levels of tetracycline on the barrier functions of human intestinal epithelial cells.

Tetracyclines are frequently used in food-producing animals to treat, control, and prevent microbial diseases. Concerns are raised regarding the effects of residual levels of tetracycline, which may be present in the food supply, for emergence of drug-resistance and transfer of antibiotic-resistance gene in intestinal microbiota. In contrast, no information is available regarding the possible effects of residual tetracycline on the gastrointestinal epithelial layer barrier-disruption. This study investigates the outcome of tetracycline treatment on intestinal epithelial cells integrity. Intestinal epithelial cells (T84) were treated at concentrations of 0.015, 0.15, 1.5, 15 and 150 µg/ml for 48 h in an in vitro cell culture model. The permeability study revealed that 15 and 150 µg/ml of tetracycline causes barrier disruption. Whereas the altered mRNA expression of notch-3, notch-4, claudin-2, claudin-8, claudin-10, claudin-15, gap junction alpha 8 and delta 2 and integrin, alpha 3 and alpha L, which are cell-integrity-related genes starts at 1.5 µg/ml tetracycline after 48 h treatment. Translocation of GFP-labeled bacteria from apical to basal comportment provides proof of concept to intestinal barrier disruption. This study is the first to evaluate whether residual concentrations of tetracycline impact epithelial cell integrity.

Effect of paeoniflorin on irritable bowel syndrome and barrier function of intestinal epithelia cell / 国际药学研究杂志

Objectives To investigate the effect of paeoniflorin(PF)in ameliorating the irritable bowel syndrome(IBS)such as diarrhea and bellyache,and the barrier function of PF on intestinal epithelial cell and inflammation.Methods The diarrhea model was conducted by exposing rat to restraint stress stimulation and bellyache model was conducted by subcutaneous injection of neostig?mine to mice.The Caco-2 monolayer cell model with barrier dysfunction was established by trypsin stimulation and the inflammatory Caco-2 cell model was established by interleukin-1β(IL-1β)stimulation.On the basis of these models,effects of PF at different doses (low 14 mg/kg·d,medium 28 mg/kg·d,and high 56 mg/kg·d)on IBS syndromes and Caco-2 cell function were investigated. Re-sults PF could significantly reduce the frequency of defecation in diarrhea rat model(P<0.05)and relieve abnormal bowel move?ments in bellyache mice model(P<0.05).PF significantly increased TEER value(P<0.01),decreased the transmittance of fluores?cein(P<0.01)and up-regulated the expression of tight junction(ZO-1)protein(P<0.01).The gene and protein expression of nucle?ar factor profilin kappa Bα(IκBα)in inflammatory Caco-2 cell model was significantly improved(P<0.01)when treated with PF. Conclusion Our study proves for the first time that PF significantly ameliorated the diarrhea and bellyache symptoms of IBS in the di?arrhea model and bellyache model.The PF intervention effect on ZO-1 and IκBα protein might be one of the molecular mechanism of ameliorating the symptoms of IBS.

IGPR-1 Is Required for Endothelial Cell-Cell Adhesion and Barrier Function.

Endothelial cell (EC) barrier function plays a prevalent regulatory mechanism for the integrity and homeostasis of blood vessels and modulates angiogenesis and immune responses. Cell adhesion molecules (CAMs) play a central role in the barrier function of ECs. Although Ig-containing and proline-rich receptor-1(IGPR-1) was recently identified as a novel CAM expressed in ECs, the molecular mechanisms underlying the function of IGPR-1 in ECs remain uncharacterized. In this report, we investigated the role of IGPR-1 in EC barrier function and the molecular mechanism of its activation in ECs. We demonstrate that IGPR-1 is localized to endothelial adherens junctions and, through trans-homophilic dimerization, regulates endothelial cell-cell adhesion and barrier function. Trans-homophilic dimerization of IGPR-1 stimulates the phosphorylation of serine 220 (Ser220), which is required for IGPR-1 to regulate endothelial barrier function and angiogenesis. Moreover, IGPR-1 chimera, which mimics the trans-homophilic dimerization of IGPR-1, induced a sustained phosphorylation of Ser220 upon stimulation with a ligand. Coordinated dimerization of IGPR-1 and its homophilic interaction modulates its adhesive function and Ser220 phosphorylation. This adhesive function of IGPR-1 contributes to the barrier function of ECs.