Reversal of murine alcoholic steatohepatitis by pepducin-based functional blockade of interleukin-8 receptors

OBJECTIVE

Alcoholic steatohepatitis is a life-threatening condition with short-term mortality up to 40%. It features hepatic neutrophil infiltration and blood neutrophilia, and may evolve from ethanol-induced breakdown of the enteric barrier and consequent bacteraemia. Signalling through CXCR1/2 G-protein-coupled-receptors (GPCRs), the interleukin (IL)-8 receptors, is critical for the recruitment and activation of neutrophils. We have developed short lipopeptides (pepducins), which inhibit post-ligand GPCR activation precisely targeting individual GPCRs.

DESIGN

Experimental alcoholic liver disease was induced by administering alcohol and a Lieber-DeCarli high-fat diet. CXCR1/2 GPCRs were blocked via pepducins either from onset of the experiment or after disease was fully established. Hepatic inflammatory infiltration, hepatocyte lipid accumulation and overall survival were assessed as primary outcome parameters. Neutrophil activation was assessed by myeloperoxidase activity and liver cell damage by aspartate aminotransferase and alanine aminotransferase plasma levels. Chemotaxis assays were performed to identify chemoattractant signals derived from alcohol-exposed hepatocytes.

RESULTS

Here, we show that experimental alcoholic liver disease is driven by CXCR1/2-dependent activation of neutrophils. CXCR1/2-specific pepducins not only protected mice from liver inflammation, weight loss and mortality associated with experimental alcoholic liver disease, but therapeutic administration cured disease and prevented further mortality in fully established disease. Hepatic neutrophil infiltration and triglyceride accumulation was abrogated by CXCR1/2 blockade. Moreover, CXCL-1 plasma levels were decreased with the pepducin therapy as was the transcription of hepatic IL-1β mRNA.

CONCLUSIONS

We propose that high circulating IL-8 in human alcoholic hepatitis may cause pathogenic overzealous neutrophil activation, and therapeutic blockade via pepducins merits clinical study.

Crosstalk Between T Lymphocytes and Lung Fibroblasts: Generation of a Hyaluronan-Enriched Extracellular Matrix Adhesive for Monocytes

In immunity and inflammation, T cells are often associated with stromal mesenchymal cells such as fibroblasts. Hyaluronan and proteins that associate with hyaluronan such as versican and tumor necrosis factor-inducible gene-6 (TSG-6) are extracellular matrix (ECM) components that promote leukocyte adhesion, accumulation, and activation. However, the factors responsible for producing this specialized ECM and its impact on inflammatory events are not well understood. In this study, we explored the role of T cells in stimulating lung fibroblasts to produce an ECM that impacts monocyte adhesion. We found that CD3/CD28-activated human CD4+ T cells when co-cultured with human lung fibroblasts stimulated the expression of mRNA for hyaluronan synthase 2 (HAS2) and decreased the expression of hyaluronidase 2 (HYAL2). This led to an increase in the deposition of hyaluronan that formed cable-like structures within the ECM. Co-culturing activated T cells with fibroblasts also led to increased expression and accumulation of TSG-6. Surprisingly, addition of activated CD4+ T cells to the fibroblasts reduced the expression of mRNA for versican, and increased the expression of enzymes that degrade versican, such as ADAMTS4 and ADAMTS9 (a disintegrin and metalloproteinase with a thrombospondin type-1 motif) leading to a decrease in versican in the ECM of the co-cultures. Furthermore, addition of human monocytes to these co-cultures resulted in elevated monocyte adhesion to the cable-like structures in the ECM when compared to controls. These results illustrate the importance of crosstalk between T cells and fibroblasts in promoting the generation of a matrix that is adhesive for monocytes. J. Cell. Biochem. 118: 2118-2130, 2017. © 2016 Wiley Periodicals, Inc.

MicroRNA-223 ameliorates alcoholic liver injury by inhibiting the IL-6-p47phox-oxidative stress pathway in neutrophils

OBJECTIVES

Chronic-plus-binge ethanol feeding activates neutrophils and exacerbates liver injury in mice. This study investigates how recent excessive drinking affects peripheral neutrophils and liver injury in alcoholics, and how miR-223, one of the most abundant microRNAs (miRNAs) in neutrophils, modulates neutrophil function and liver injury in ethanol-fed mice.

DESIGNS

Three hundred alcoholics with (n=140) or without (n=160) recent excessive drinking and 45 healthy controls were enrolled. Mice were fed an ethanol diet for 10 days followed by a single binge of ethanol.

RESULTS

Compared with healthy controls or alcoholics without recent drinking, alcoholics with recent excessive drinking had higher levels of circulating neutrophils, which correlated with serum levels of alanine transaminase (ALT) and aspartate transaminase (AST). miRNA array analysis revealed that alcoholics had elevated serum miR-223 levels compared with healthy controls. In chronic-plus-binge ethanol feeding mouse model, the levels of miR-223 were increased in both serum and neutrophils. Genetic deletion of the miR-223 gene exacerbated ethanol-induced hepatic injury, neutrophil infiltration, reactive oxygen species (ROS) and upregulated hepatic expression of interleukin (IL)-6 and phagocytic oxidase (phox) p47^phox. Mechanistic studies revealed that miR-223 directly inhibited IL-6 expression and subsequently inhibited p47^phox expression in neutrophils. Deletion of the p47^phox gene ameliorated ethanol-induced liver injury and ROS production by neutrophils. Finally, miR-223 expression was downregulated, while IL-6 and p47^phox expression were upregulated in peripheral blood neutrophils from alcoholics compared with healthy controls.

CONCLUSIONS

miR-223 is an important regulator to block neutrophil infiltration in alcoholic liver disease and could be a novel therapeutic target for the treatment of this malady.

A Prospective Study Investigating Prediagnostic Leukocyte Telomere Length and Risk of Developing Rheumatoid Arthritis in Women

OBJECTIVE

To prospectively examine the association between leukocyte telomere length (LTL) and subsequent rheumatoid arthritis (RA) development in women.

METHODS

Using a case-control design nested within the prospective Nurses' Health Study (NHS), NHS II (NHSII), and Women's Health Study (WHS), each validated case of RA with a prediagnostic blood sample was matched to 3 controls by cohort, age, menopausal status, postmenopausal hormone therapy, and blood collection covariates. We measured telomere length in genomic DNA extracted from stored buffy coat samples using quantitative PCR. We used unconditional logistic regression to determine OR and 95% CI, and random-effects metaanalysis to combine study results.

RESULTS

In total, we analyzed 296 incident RA cases and 827 matched controls. Mean age of diagnosis among women who developed RA was 60.5 in NHS/NHSII and 61.3 in WHS. Metaanalysis demonstrated that longer prediagnostic LTL was associated with increased RA risk when women in the longest versus shortest LTL tertile were compared (OR 1.51, 95% CI 1.03-2.23, Pheterogeneity = 0.27). However, statistically significant between-study heterogeneity was observed for the intermediate tertile category (Pheterogeneity = 0.008). We did not observe heterogeneity by menopausal status, inflammatory cytokine levels, age at diagnosis, age at blood collection, body mass index, seropositivity, or HLA-DRβ1 shared epitope status.

CONCLUSION

Our results do not support an involvement for short LTL preceding RA development.

A study of the reaction of the white blood corpuscles in bovines at parturition with a consideration of the evidence of the action of the adrenal cortical hormone (cortisone)

A study was made of the reaction of the white blood corpuscles in bovines at parturition.

Graphs made from the differential total counts of the white blood corpuscles from shortly before calving and at intervals through the period of parturition and for 24–48 hr. after calving show a definite absolute lymphopoenia with a rise in the neturophils.

The type of graph produced resembles that found in bovines when cortisone is injected.

The peak of the white blood cell reaction usually takes place about 5–9 hr. after the delivery of the calf. This is also the period of the peak reaction in the cellular relations after injection of cortisone.

The observations recorded seem to afford positive evidence that C 11 hydroxy steroids (cortisone) are poured out in the last stage of parturition in the normal bovine. The desensitization of the skin in animals which were sensitized to Trichomonas foetus an which was found at this time is considered to be connected with the action of the hormone.

Culture of human leukaemic blood cells in vitro; normal and abnormal cell division and maturation

Images

The splanchnic removal of bacteria from the blood stream of leukopenic rabbits

In rabbits subjected to profound damage of the blood-forming tissues by the use of benzene and mechlorethamine hydrochloride, no impairment of efficiency in the splanchnic removal of M. aureus from the blood stream could be demonstrated by a method involving catheterization of the hepatic vein. All evidence continues to indicate that a bacteriemia cannot be maintained unless the organisms are introduced constantly into the blood stream from some source. The importance of the leukocyte in the establishment and clearing of the bacteriemias appears to lie in its phagocytic activities at the local source of the bacteriemia rather than in any quantitatively significant phagocytosis of organisms circulating in the blood stream. The present studies suggest that in the study of the leukopenic state attention should be directed more especially toward the identification and eradication of the local source of organisms.

Inhibitors of the beta-glucuronidase of rabbit polymorphonuclear leucocytes

As previously reported, rabbit polymorphonuclear leucocytes contain an enzyme capable of hydrolyzing biosynthetic phenolphthalein mono-β-glucuronide. The effect of a number of inhibitors on cell-free preparations of this enzyme was studied. Many of the usual enzyme inhibitors were without effect, but certain dicarboxylic acids were strong inhibitors. These were (in order of activity): D-glucosaccharic acid, D-mucic acid, L-malic acid, mesotartaric acid, DL-malic acid, and L-tartaric acid. The nature of the inhibition was competitive. The Michaelis constant, Ks, was evaluated for phenolphthalein mono-β-glucuronide and values of Ki were estimated for glucosaccharic acid, mucic acid, DL-malic acid, and mesotartaric acid. Heparin in high concentration was slightly inhibitory, but the nature of the inhibition was noncompetitive. For each of the inhibitors studied, the extent of the inhibition was influenced by the hydrogen ion concen tration. At a pH greater than 4.5, the optimum for the enzyme under the conditions used, the degree of inhibition was less, and at a pH less than 4.5 the degree of inhibition was greater.

The survival of staphylococci within human leukocytes

In a study of the phagocytosis of staphylococci by human leukocytes it has been observed that strains of staphylococci producing human infection were phagocytized by human polymorphonuclear leukocytes in vitro under conditions in which virulent pneumococci, streptococci, or Klebsiella were rarely engulfed. In the presence of human leukocytes in plasma there was a rapid fall in the numbers of viable staphylococci of both pathogenic and non-pathogenic strains, the beginning of which was detectable in 10 to 15 minutes. The fall in culturable pathogenic microorganisms was considerably less marked, however, and a rapid resurgence of growth occurred in 4 to 8 hours, whereas the number of culturable non-pathogenic microorganisms remained low for 18 to 24 hours. These differences appear to be explained by the observation that a significant number of microorganisms of pathogenic strains were able to survive within human leukocytes. Such intracellular survival was found to be associated with evidence of destruction of the leukocytes. In contrast, non-pathogenic strains of staphylococci failed to survive within human polymorphonuclear leukocytes following ingestion.

The acceleration and inhibition of migration of human leucocytes in vitro by plasma protein fractions

A new method is described for the quantitative study of leucocyte migration. Blood drawn into a capillary tube is centrifuged, forming a buffy coat. The migration of the leucocytes from the buffy coat into the plasma is measured by means of an ocular micrometer. While there is a great deal of variation from one normal individual to another in the migration rates of leucocytes those of each individual show relatively little variation in migration from day to day (Table I). In all cases of illness studied, the average migration rates fall within the normal range, but there was a wider variation in the day to day migration rate than obtains in normal healthy individuals (Tables II and III). From experiments in which the cells with typically "slow" and "fast" migration rates were tested in both the "slow" and "fast" plasmas, it could be concluded that while the cells invariably have some influence on the migration rate, the major factors influencing leucocyte migration reside in the plasma (Table V). Experiments in which the plasma proteins were fractionated according to the method of Lever et al. indicated the presence of a system of proteins which regulate leucocyte migration. A heat-labile (56°C. for 30 minutes) component of fraction II was able to accelerate leucocyte migration, while fraction III acted as an inhibitor (Tables IX and X).