Resolving Conflicting Signals: Cross Inhibition of Cytokine Signaling Pathways

Genome-wide association study to identify genetic loci associated with gastrointestinal nematode resistance in Katahdin sheep

Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep. A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep. Forty animals were selected from the top and bottom 10% of estimated breeding values for FEC from a total pool of 641 sires and ram lambs. Samples were genotyped using Applied Biosystems™ Axiom™ Ovine Genotyping Array (50K) consisting of 51 572 SNPs. Following quality control, 46 268 SNPs were included in subsequent analyses. Analyses were conducted using a linear regression model in plink v1.90 and a single‐locus mixed model in snp and variation suite. Genome‐wide significance was determined by a Bonferroni correction for multiple testing. Using linear regression, loci on chromosomes 2, 3, 16, 23 and 24 were significantly associated at the genome level with FEC estimated breeding values, and we identified a region on chromosome 2 that was significant using both statistical analyses. We suggest a potential role for the gene DIS3L2 for gastrointestinal nematode resistance in Katahdin sheep, although further research is needed to validate these findings.

The Extract of Chrysanthemum zawadskii var. latilobum Ameliorates Collagen-Induced Arthritis in Mice

Chrysanthemum zawadskii var. latilobum (CZ) has been used for beverage or tea and also as folk medicine for the remedy of diverse inflammatory diseases. Nevertheless, the therapeutic effect of CZ on arthritis remains to be unknown. In this paper we aim to investigate the CZ's antiarthritic effect and mechanism of action both in vitro and in vivo. To assess CZ's antiarthritic effect, mouse models of type II collagen-induced arthritis (CIA) were used. Mice were used to gauge clinical arthritis index and histopathological changes. Reverse transcriptase-polymerase chain reaction (RT-PCR), western blotting, electrophoretic mobility shift assay (EMSA), and other biological methods were adopted to measure CZ's effect on arthritis and to understand the veiled mechanism of action. CZ greatly suppressed CIA, histopathological score, bone erosion, and osteoclast differentiation. Mechanistically, CZ inhibited the production of various inflammatory and arthritic mediators like inflammatory cytokines, matrix metalloproteinases (MMPs), and chemokines. Of note, CZ significantly suppressed the activation of the NF-κB pathway in vivo. CZ exerted an antiarthritic effect in CIA mice by curbing the production of crucial inflammatory and arthritis mediators. This study warrants further investigation of CZ for the use in human rheumatoid arthritis (RA).

A mixture of Trachelospermi caulis and Moutan cortex radicis extracts suppresses collagen-induced arthritis in mice by inhibiting NF-κB and AP-1

OBJECTIVES

We aimed to determine the anti-arthritis effect and its mechanism of a combination of herbal extracts from Trachelospermi caulis (TC) and Moutan cortex radicis (MC) (TCMC).

METHODS

The anti-arthritis activity of TCMC was assessed using a mouse model of type II collagen-induced arthritis (CIA). Reverse transcriptase-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), electrophoretic mobility shift assay (EMSA) and other biological assays were performed.

KEY FINDINGS

TCMC significantly ameliorated various inflammatory parameters, such as clinical arthritis index, histological deformation of joints, serum levels of rheumatoid arthritis biomarkers (cartilage oligomeric matrix protein, serum amyloid P and anti-collagen type II IgG antibody), and Th1-related responses (T cell proliferation, and production of Interferon-γ and interleukin (IL)-2 in splenocytes isolated from CIA mice). The production of matrix metalloproteinases (MMPs), pro-inflammatory cytokines (tumour necrosis factor-α, IL-1β and IL-6) and chemokines (macrophage inflammatory protein-1, monocyte chemoattractant protein-1, and Regulated upon Activation, Normal T-cell Expressed, and Secreted) was suppressed by TCMC in CIA mice. In addition, the number of osteoclasts in the hind tibia was significantly decreased. With regard to the mechanism, TCMC suppressed the activation of the transcription factors nuclear factor (NF)-κB and activator protein (AP)-1.

CONCLUSIONS

TCMC exerts an anti-arthritis effect in CIA mice by suppression of the production of various inflammatory factors and the formation of osteoclasts through the inhibition of NF-κB and AP-1 activation.

Morus bombycis Koidzumi extract suppresses collagen-induced arthritis by inhibiting the activation of nuclear factor-κB and activator protein-1 in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Morus bombycis Koidzumi is widely distributed in Asia. In Korea, it has been used in traditional medicine because of its apparent anti-inflammatory, antioxidant, and hepatoprotective properties.

AIM OF THE STUDY

Although the extract of Morus bombycis Koidzumi (MB) has long since been used as a traditional anti-inflammatory medicine in Korea, its effect on arthritis remains unknown. We aimed to investigate the anti-arthritis activity of MB and the mechanism underlying it.

MATERIALS AND METHODS

The anti-arthritis activity of MB was assessed by using mouse models of type II collagen-induced arthritis (CIA). The clinical arthritis index and histopathological changes were evaluated in mice. Reverse transcriptase-polymerase chain reaction (RT-PCR), electrophoretic mobility shift assay (EMSA), and other biologic approaches were used for measuring the effect of MB on arthritis and understanding the underlying mechanism.

RESULTS

MB significantly decreased the clinical arthritis index in CIA mice; this was confirmed by examining histological changes in joints. Infiltration of immune cells, synovial hyperplasia, cartilage destruction, and bone erosion in the hind paw were largely suppressed by MB. The mRNA levels of matrix metalloproteinase (MMP)-1/MMP-3, inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6), and chemokines (macrophage inflammatory protein (MIP)-1, monocyte chemoattractant protein (MCP)-1, RANTES) were significantly suppressed by MB in a dose-dependent manner. The number of osteoclasts in the hind tibia was also significantly decreased. With regard to the mechanism, MB suppressed the activation of nuclear factor (NF)-κB and activator protein (AP)-1 in CIA mice.

CONCLUSIONS

MB produced an anti-arthritis effect in CIA mice by inhibiting the production of critical inflammatory mediators and osteoclasts through the downregulation of NF-κB and AP-1.

(5R)-5-hydroxytriptolide (LLDT-8), a novel triptolide analog mediates immunosuppressive effects in vitro and in vivo

A series of triptolide analogs have been successfully synthesized. In the present study we demonstrated one of them, (5R)-5-hydroxytriptolide (LLDT-8), showed low cytotoxicity and relative high immunosuppressive activities as compared with its parent compound triptolide in vitro. The CC50 values of triptolide and LLDT-8 were 2.1+/-0.3 and 256.6+/-73.8 nM, respectively. LLDT-8 significantly inhibited the proliferation of splenocytes induced by concanavalin A (ConA), lipopolysaccharide (LPS), or mixed lymphocyte reaction (MLR), and the IC50 values were 131.7+/-32.4, 171.5+/-17.3, and 38.8+/-5.1 nM, respectively. LLDT-8 (25, 50, 100 nM) dose-dependently reduced the production of Th1 type cytokines (IFN-gamma, IL-2) and inflammatory cytokines (TNF-alpha, IL-6) in vitro. Administration of LLDT-8 (at the low dose of 0.4 microg/kg, i.p.; 40 microg/kg, p.o.) intensively suppressed 2,4-dinitrofluorobenzene (DNFB)-induced delayed type hypersensitivity (DTH) reactions. Treatment with LLDT-8 (40 microg/kg, i.p. and p.o.) also markedly inhibited the sheep red blood cell (SRBC)-induced antibody production in BLAB/c mice. Most importantly, comparing with triptolide, LLDT-8 significantly reduced toxicity, with a 122-fold lower cytotoxicity in vitro and 10-fold lower acute toxicity in vivo. The results suggested that LLDT-8 had immunosuppressive activities in both cellular and humoral immune responses. LLDT-8 might be a potential therapeutic agent for immune-related diseases.

Regulation of the immune system by SOCS family adaptor proteins

Signal transduction via cytokine receptors is regulated by several mechanisms that control initiation, magnitude and duration of the signaling pathways. Cytokine-induced SOCS family adaptors function as feedback inhibitors of cytokine receptor signaling by inhibiting the JAK-STAT signal transduction pathway. Specific gene-targeted mice have unveiled critical, non-overlapping functions for SOCS1 and SOCS3 in lymphocyte development and homeostasis, and in the regulation of macrophage and dendritic cell functions. In this review, we will discuss the structure of SOCS proteins, mechanisms by which they control the JAK-STAT pathway and their role in immune regulation.

t(5;14)/HOX11L2-positive T-cell acute lymphoblastic leukemia. A collaborative study of the Groupe Français de Cytogénétique Hématologique (GFCH)

To accurately estimate the incidence of HOX11L2 expression, and determine the associated cytogenetic features, in T-cell acute lymphoblastic leukemia (T-ALL), the Groupe Français de Cytogénétique Hématologique (GFCH) carried out a retrospective study of both childhood and adult patients. In total, 364 patients were included (211 children </=15 years and 153 adults), and 67 (18.5%) [47 children (22.4%) and 20 adults (13.1%)] were shown to either harbor the t(5;14)q35;q32) translocation or express the HOX11L2 gene or both. Most of the common hematological parameters did not show significant differences within positive and negative populations, whereas the incidence of CD1a+/CD10+ and cytoplasmic CD3+ patients was significantly higher in positive than in negative children. Out of the 63 positive patients investigated by conventional cytogenetics, 32 exhibited normal karyotype, whereas the others 31 showed clonal chromosome abnormalities, which did not include classical T-ALL specific translocations. Involvement of the RANBP17/HOX11L2 locus was ascertained by fluorescence in situ hybridization in six variant or alternative (three-way translocation or cytogenetic partner other than 14q32) translocations out of the 223 patients. Our results also show that HOX11L2 expression essentially occurs as a result of a 5q35 rearrangement, but is not associated with another identified T-ALL specific recurrent genetic abnormality, such as SIL-TAL fusion or HOX11 expression.

Physiology of erythropoietin during mammalian development

Growth is a fundamental process of mammalian development. Several observations regarding regulation of erythropoiesis during growth are not easily explained by the hypoxia-erythropoietin (Epo) concept. This review focuses primarily on this aspect of the physiology of Epo. The question is raised of whether this regulation during growth is based on the hypoxia-Epo mechanism alone, or whether Epo acts in concert with general growth-promoting factors, particularly growth hormone (GH) and the insulin-like growth factors (IGF-I and -II). Supporting the latter hypothesis is the observation that the Epo and GH/IGF systems are activated by hypoxia and share similar receptors and pathways. Recent studies indicate that human fetal and infant growth is stimulated by GH, IGF-I and IGF-II. Epo, GH and IGFs are expressed early in fetal life. Although the rate of erythropoiesis in the fetus is high, serum Epo levels are low. The Epo response to hypoxia in the fetus and neonate is reduced compared with adults. Following delivery the Epo levels vary between species, probably related to the oxygen transport capacity of the hemoglobin (Hb) mass. IGF-I levels are low in the fetus and increase slowly following birth, except in preterm infants in whom the levels decline. In all mammals Hb declines following birth, giving rise to "early anemia". Except in the human, Epo levels increase proportionally with the fall in Hb, but there is a discrepancy between the curves for serum immunoreactive Epo (siEpo) and for erythropoiesis stimulating factors (ESF): the latter include other stimulatory factors in addition to Epo. Hypertransfusion of mice in the period of "early anemia" suppresses siEpo, but not ESF and erythropoiesis, as it does in adult mice. GH and IGF-I have direct effects on erythropoiesis in vitro and act particularly at the later stages of red cell differentiation. IGF-I acts synergistically with Epo, and its effects are most marked when Epo levels are low. Human recombinant (rhu) IGF-I stimulates erythropoiesis in neonatal rats, but not in newborn mice and lambs. In adult mice, in hypophysectomized rats and in mice with end-stage renal failure, however, a stimulatory effect of this growth factor was found on red cell production. RhuGH stimulates erythropoiesis in GH-deficient short children.

CONCLUSION

Fetal and early postnatal erythropoiesis are dependent on factors in addition to Epo. The likely candidates are GH and IGF-I. The in vitro stimulating effects of these factors on erythropoiesis are convincing, but more data are needed on the in vivo effects.

Array-based multiplexed screening and quantitation of human cytokines and chemokines

HydroGel-coated slide is a porous substrate based on a polymer matrix that provides a three-dimensional hydrophilic environment similar to free solution suitable for biomolecular interactions. This substrate has been used to develop fluorescence-based multiplexed cytokine immunoassays. Forty-three monoclonal antibodies (mAb) of cytokines and chemokines were printed at a volume of 350 pL per spot using a Packard BioChip Arrayer. For each probe, four replicates were printed at a pitch of 500 microm in the layout of a 13 x 16 pattern on a 12 x 12 mm2 HydroGel pad. Cytokines and chemokines that are captured by the arrayed mAbs are detected by using another biotinylated mAb, following by the addition of a Texas Red-conjugated streptavidin. The fluorescent images of arrays were recorded using a Packard ScanArray 5000 confocal slide scanner and quantitated using Packard QuantArray software. Experiments demonstrated that 43 cytokines and chemokines could be simultaneously screened and quantitated in conditioned culture media, cell lysates, and human plasma. Using this chip, we have examined cytokine expression in breast cancer cells and identified the chemokines associated with human cervical cancers.

ASB-2 inhibits growth and promotes commitment in myeloid leukemia cells

In acute promyelocytic leukemia (APL) cells harboring the promyelocytic leukemia retinoic acid receptor alpha (PML-RARalpha) chimeric protein, retinoic acid (RA)-induced differentiation is triggered through a PML-RARalpha signaling resulting in activation of critical target genes. Induced differentiation of APL cells is always preceded by withdrawal from the cell cycle and commitment events leading to terminal differentiation. Here we have identified the human ankyrin repeat-containing protein with a suppressor of cytokine signaling box-2 (ASB-2) cDNA, as a novel RA-induced gene in APL cells. PML-RARalpha strongly enhanced RA-induced ASB-2 mRNA expression. In myeloid leukemia cells, ASB-2 expression induced growth inhibition and chromatin condensation recapitulating early events critical to RA-induced differentiation of APL cells.

Complement and IL-12: yin and yang

Interleukin 12 (IL-12) is central to the orchestration of cell-mediated immune responses in the innate as well as the adaptive immune system. Recent studies of the pathogenesis of diseases as disparate as measles and asthma have suggested that the complement system, itself at the interface of innate and adaptive immunity, is a biologically relevant regulator of IL-12 production. These data are reviewed here.