Hyaluronan (HA) fragments induce chemokine gene expression in alveolar macrophages. The role of HA size and CD44

Hyaluronan (HA) is a glycosaminoglycan constituent of extracellular matrix. In its native form HA exists as a high molecular weight polymer, but during inflammation lower molecular weight fragments accumulate. We have identified a collection of inflammatory genes induced in macrophages by HA fragments but not by high molecular weight HA. These include several members of the chemokine gene family: macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta, cytokine responsive gene-2, monocyte chemoattractant protein-1, and regulated on activation, normal T cell expressed and secreted. HA fragments as small as hexamers are capable of inducing expression of these genes in a mouse alveolar macrophage cell line, and monoclonal antibody to the HA receptor CD44 completely blocks binding of fluorescein-labeled HA to these cells and significantly inhibits HA-induced gene expression. We also investigated the ability of HA fragments to induce chemokine gene expression in human alveolar macrophages from patients with idiopathic pulmonary fibrosis and found that interleukin-8 mRNA is markedly induced. These data support the hypothesis that HA fragments generated during inflammation induce the expression of macrophage genes which are important in the development and maintenance of the inflammatory response.

Hyaluronan fragments induce nitric-oxide synthase in murine macrophages through a nuclear factor kappaB-dependent mechanism

Activated macrophages play a critical role in controlling chronic tissue inflammation through the release of a variety of mediators including cytokines, chemokines, growth factors, active lipids, reactive oxygen, and nitrogen species. The mechanisms that regulate macrophage activation in chronic inflammation are poorly understood. A hallmark of chronic inflammation is the turnover of extracellular matrix components, and recent work has suggested that interactions with the extracellular matrix can exert important influences on macrophage effector functions. We have examined the effect of low molecular weight fragments of the extracellular matrix glycosaminoglycan hyaluronan (HA) on the induction of nitric-oxide synthase (iNOS) in macrophages. We found that HA fragments induce iNOS mRNA, protein and activity alone, and markedly synergize with interferon-gamma to induce iNOS gene expression in murine macrophages. In addition, we found that resident tissue alveolar macrophages respond minimally, but inflammatory alveolar macrophages exhibit a marked induction in iNOS expression in response to HA fragments. Finally, we demonstrate that the mechanism of HA fragment-induced expression of iNOS requires activation of the transcriptional regulator nuclear factor kappaB. These data support the hypothesis that HA may be an important regulator of macrophage activation at sites of chronic tissue inflammation.

Hyaluronan fragments synergize with interferon-gamma to induce the C-X-C chemokines mig and interferon-inducible protein-10 in mouse macrophages

Hallmarks of chronic inflammation and tissue fibrosis are increased influx of activated inflammatory cells, mediator release, and increased turnover and production of the extracellular matrix (ECM). Recent evidence has suggested that fragments of the ECM component hyaluronan play a role in chronic inflammation by inducing macrophage expression of chemokines. Interferon-gamma (IFN-gamma), an important regulator of macrophage functions, has been shown to induce the C-X-C chemokines Mig and IP-10. These chemokines affect T-cell recruitment and inhibit angiogenesis. The purpose of this investigation was to determine the effect of hyaluronan (HA) on IFN-gamma-induced Mig and IP-10 expression in mouse macrophages. We found a marked synergy between HA and IFN-gamma on Mig and IP-10 mRNA and protein expression in mouse macrophages. This was most significant with Mig, which was not induced by HA alone. The synergy was specific for HA, was not dependent on new protein synthesis, was not mediated by tumor necrosis factor-alpha, was selective for Mig and IP-10, and occurred at the level of gene transcription. These data suggest that the ECM component HA may influence chronic inflammatory states by working in concert with IFN-gamma to alter macrophage chemokine expression.

Interaction of interferon regulatory factor-1 and nuclear factor kappaB during activation of inducible nitric oxide synthase transcription

We investigated the molecular mechanism for the synergistic induction of inducible nitric oxide synthase transcription by TNF-alpha and IFN-gamma. Since TNF-alpha and IFN-gamma stimulate cells in part by activating NF-kappaB and IRF-1, we hypothesized that these two transcription factors interact with each other. IRF-1 and NF-kappaB co-localize in the nucleus of stimulated macrophages. Co-immunoprecipitation experiments show that IRF-1 and NF-kappaB interact in stimulated but not resting cells. Super-shift experiments show that IRF-1 and NF-kappaB interact while binding to their respective DNA binding sites. These results demonstrate the existence of a physical interaction between IRF-1 and NF-kappaB proteins in vivo. We next suggested that this interaction between IRF-1 and NF-kappaB bends the DNA of the iNOS promoter region. Using a cyclization assay, we demonstrate that nuclear extracts from stimulated cells accelerate the rate of conversion of a linear to circular DNA, compared to extracts from resting cells. However, stimulated nuclear extracts cannot affect the rate of cyclization of a promoter with a mutant IRE or kappaB site. Furthermore, stimulated nuclear extracts depleted of IRF-1 and NF-kappaB cannot induce cyclization. We conclude that IRF-1 and NF-kappaB interact in vivo, and that this interaction physically bends the indicible nitric oxide synthase promoter DNA. This interaction may explain the mechanism by which IFN-gamma synergistically augments inducible nitric oxide synthase transcription.

Kalirin inhibition of inducible nitric-oxide synthase

Nitric oxide (NO) acts as a neurotransmitter. However, excess NO produced from neuronal NO synthase (nNOS) or inducible NOS (iNOS) during inflammation of the central nervous system can be neurotoxic, disrupting neurotransmitter and hormone production and killing neurons. A screen of a hippocampal cDNA library showed that a unique region of the iNOS protein interacts with Kalirin, previously identified as an interactor with a secretory granule peptide biosynthetic enzyme. Kalirin associates with iNOS in vitro and in vivo and inhibits iNOS activity by preventing the formation of iNOS homodimers. Expression of exogenous Kalirin in pituitary cells dramatically reduces iNOS inhibition of ACTH secretion. Thus Kalirin may play a neuroprotective role during inflammation of the central nervous system by inhibiting iNOS activity.

Emergence of a new GII.17 norovirus variant in patients with acute gastroenteritis in Jiangsu, China, September 2014 to March 2015

From September 2014 to March 2015, 23 outbreaks of norovirus (NoV) acute gastroenteritis occurred in Jiangsu, China. Partial sequencing of the NoV capsid gene suggested that 16 of the 23 outbreaks were related to a new GII.17 variant. This variant was first detected in sporadic specimens in October 2014, and became predominant in February 2015. Analysis of the RNA-dependent RNA polymerase (RdRp), and complete capsid including the protruding domain P2 sequences confirmed this GII.17 variant as distinct from previously identified GII variants.

An inducible nitric-oxide synthase (NOS)-associated protein inhibits NOS dimerization and activity

A variety of transcriptional and post-transcriptional mechanisms regulate the expression of the inducible nitric-oxide synthase (iNOS, or NOS2). Although neurons and endothelial cells express proteins that interact with and inhibit neuronal NOS and endothelial NOS, macrophage proteins that inhibit NOS2 have not been identified. We show that murine macrophages express a 110-kDa protein that interacts with NOS2, which we call NOS-associated protein-110 kDa (NAP110). NAP110 directly interacts with the amino terminus of NOS2, and inhibits NOS catalytic activity by preventing formation of NOS2 homodimers. Expression of NAP110 may be a mechanism by which macrophages expressing NOS2 protect themselves from cytotoxic levels of nitric oxide.

Regulation of plasminogen activator inhibitor-1 and urokinase by hyaluronan fragments in mouse macrophages

Pulmonary inflammation and fibrosis are characterized by increased turnover and production of the extracellular matrix as well as an impairment of lung fibrinolytic activity. Although fragments of the extracellular matrix component hyaluronan induce macrophage production of inflammatory mediators, the effect of hyaluronan on the fibrinolytic mediators plasminogen activator inhibitor (PAI)-1 and urokinase-type plasminogen activator (uPA) is unknown. This study demonstrates that hyaluronan fragments augment steady-state mRNA, protein, and inhibitory activity of PAI-1 as well as diminish the baseline levels of uPA mRNA and inhibit uPA activity in an alveolar macrophage cell line. Hyaluronan fragments alter macrophage expression of PAI-1 and uPA at the level of gene transcription. Similarly, hyaluronan fragments augment PAI-1 and diminish uPA mRNA levels in freshly isolated inflammatory alveolar macrophages from bleomycin-treated rats. These data suggest that hyaluronan fragments influence alveolar macrophage expression of PAI-1 and uPA and may be a mechanism for regulating fibrinolytic activity during lung inflammation.

Long non-coding RNA HCG11 modulates glioma progression through cooperating with miR-496/CPEB3 axis

Objectives

It has been widely reported that long non‐coding RNAs (lncRNAs) can participate in multiple biological processes of human cancers. lncRNA HLA complex group 11 (HCG11) has been reported in human cancers as a tumour suppressor. This study focused on investigating the function and mechanism of HCG11 in glioma.

Materials and methods

Based on The Cancer Genome Atlas (TCGA) data set and qRT‐PCR analysis, the expression pattern of HCG11 was identified in glioma samples. The mechanism associated with HCG11 downregulation was determined by mechanism experiments. Gain‐of‐function assays were conducted for the identification of HCG11 function in glioma progression. Mechanism investigation based on the luciferase reporter assay, RIP assay and pull‐down assay was used to explore the downstream molecular mechanism of HCG11. The role of molecular pathway in the progression of glioma was analysed in accordance with the rescue assays.

Results

HCG11 was expressed at low level in glioma samples compared with normal samples. FOXP1 could bind with HCG11 and transcriptionally inactivated HCG11. Overexpression of HCG11 efficiently suppressed cell proliferation, induced cell cycle arrest and promoted cell apoptosis. HCG11 was predominantly enriched in the cytoplasm of glioma cells and acted as a competing endogenous RNAs (ceRNAs) by sponging micro‐496 to upregulate cytoplasmic polyadenylation element binding protein 3 (CPEB3). CEPB3 and miR‐496 involved in HCG11‐mediated glioma progression.

Conclusions

HCG11 inhibited glioma progression by regulating miR‐496/CPEB3 axis.

Effects of Condensation on Peri-implant Bone Density and Remodeling

Bone condensation is thought to densify interfacial bone and thus improve implant primary stability, but scant data substantiate either claim. We developed a murine oral implant model to test these hypotheses. Osteotomies were created in healed maxillary extraction sites 1) by drilling or 2) by drilling followed by stepwise condensation with tapered osteotomes. Condensation increased interfacial bone density, as measured by a significant change in bone volume/total volume and trabecular spacing, but it simultaneously damaged the bone. On postimplant day 1, the condensed bone interface exhibited microfractures and osteoclast activity. Finite element modeling, mechanical testing, and immunohistochemical analyses at multiple time points throughout the osseointegration period demonstrated that condensation caused very high interfacial strains, marginal bone resorption, and no improvement in implant stability. Collectively, these multiscale analyses demonstrate that condensation does not positively contribute to implant stability.

Knockdown of lncRNA LEF1-AS1 inhibited the progression of oral squamous cell carcinoma (OSCC) via Hippo signaling pathway

It is verified that long non-coding RNAs (lncRNAs) play crucial roles in various cancers. LncRNA LEF1-AS1 is a reported oncogene in colorectal cancer and glioblastoma. In this study, we unveiled that LEF1-AS1 markedly increased in oral squamous cell carcinoma (OSCC) tissues and cell lines. Besides, OSCC patients with high levels of LEF1-AS1 were apt to poor prognosis. Functionally, LEF1-AS1 knockdown inhibited cell survival, proliferation and migration, whereas enhanced cell apoptosis and induced G0/G1 cell cycle arrest in vitro. Consistently, LEF1-AS1 silence hindered tumor growth in vivo. Moreover, LEF1-AS1 inhibition stimulated the activation of Hippo signaling pathway through directly interacting with LATS1. Furtherly, we disclosed that LEF1-AS1 silence abolished the interaction of LEF1-AS1 with LATS1 while enhanced the binding of LATS1 to MOB, therefore promoting YAP phosphorylation but impairing YAP1 nuclear translocation. Additionally, we demonstrated that LEF1-AS1 regulated YAP1 translocation via a LATS1-dependent manner. Furthermore, we also uncovered that YAP1 overexpression abolished the suppressive impact of LEF1-AS1 repression on the biological processes of OSCC cells. In a word, we concluded that LEF1-AS1 served an oncogenic part in OSCC through suppressing Hippo signaling pathway by interacting with LATS1, suggesting the therapeutic and prognostic potential of LEF1-AS1 in OSCC.

Case-control study of risk factors for human infection with influenza A(H7N9) virus in Jiangsu Province, China, 2013

We describe a case-control study performed in Jiangsu, China, to evaluate risk factors for human infection with novel avian influenza A(H7N9) virus. Twenty-five cases and 93 controls matched by age, sex, and location were included in the study. Direct contact with poultry or birds in the two weeks before illness onset, chronic medical conditions (hypertension excluded), and environment-related exposures were significantly associated with A(H7N9) infection.

Increased expression of the type I interferon-inducible gene, lymphocyte antigen 6 complex locus E, in peripheral blood cells is predictive of lupus activity in a large cohort of Chinese lupus patients

Several studies by microarray analysis and real-time polymerase chain reaction (RT-PCR) reveal that type I interferon-inducible genes (IFIGs) are implicated in systemic lupus erythematosus (SLE). To find a potential clinical biomarker capable of monitoring lupus disease activity clinically, quantitative RT-PCR was used to identify transcript expression levels of 13 type I IFIGs in peripheral blood cells in 144 patients with SLE, 27 non-SLE patients and 60 healthy controls and then analyse connections between gene expression and disease activity. The expression levels of five type I IFIGs (LY6E, OAS3, IFIT4, OAS1 and OAS2) were significantly higher in the SLE group than in the healthy and non-SLE controls. LY6E gene that had highest expression was chosen to analyse the association of expression level with clinical features. Compared to low LY6E expression group, SLE patients with high LY6E expression had higher SLEDAI-2K score, increased 24 h urine protein and lower blood C3 complement. Active SLE patients had more elevated LY6E expression than stable patients. And LY6E expression levels in patients with SLE were strongly correlated with their SLEDAI-2K scores. Our results indicate that increased expression of LY6E gene in peripheral blood cells in patients with SLE is correlated with lupus activity and may be a useful, noninvasive biomarker for assessing SLE disease activity.

WNT3A accelerates delayed alveolar bone repair in ovariectomized mice

Our goal was to evaluate alveolar bone healing in OVX mice, and to assess the functional utility of a WNT-based treatment to accelerate healing in mice with an osteoporotic-like bony phenotype.

INTRODUCTION

Is osteoporosis a risk factor for dental procedures? This relatively simple question is exceedingly difficult to answer in a clinical setting, for two reasons. First, as an age-related disease, osteoporosis is frequently accompanied by age-related co-morbidities that can contribute to slower tissue repair. Second, the intervals at which alveolar bone repair are assessed in a clinical study are often measured in months to years. This study aimed to evaluate alveolar bone repair in ovariectomized (OVX) mice and provide preclinical evidence to support a WNT-based treatment to accelerate alveolar bone formation.

METHODS

OVX was performed in young mice to produce an osteoporotic-like bone phenotype. Thereafter, the rate of extraction socket healing and osteotomy repair was assessed. A liposomal WNT3A treatment was tested for its ability to promote alveolar bone formation in this OVX-induced model of bone loss.

RESULTS

Bone loss was observed throughout the murine skeleton, including the maxilla, and mirrored the pattern of bone loss observed in aged mice. Injuries to the alveolar bone, including tooth extraction and osteotomy site preparation, both healed significantly slower than the same injuries produced in young controls. Given sufficient time, however, all injuries eventually healed. In OVX mice, osteotomies healed significantly faster if they were treated with L-WNT3A.

CONCLUSIONS

Alveolar bone injuries heal slower in OVX mice that exhibit an osteoporotic-like phenotype. The rate of alveolar bone repair in OVX mice can be significantly promoted with local delivery of L-WNT3A.

Hydrogen gas (XEN) inhalation ameliorates airway inflammation in asthma and COPD patients

BACKGROUND

Hydrogen was proven to have anti-oxidative and anti-inflammation effects to various diseases.

AIM

We wish to investigate the acute effects of inhaled hydrogen on airway inflammation in patients with asthma and chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective study.

METHODS

In total, 2.4% hydrogen containing steam mixed gas (XEN) was inhaled once for 45 min in 10 patients with asthma and 10 patients with COPD. The levels of granulocyte-macrophage colony stimulating factor, interferon-γ, interleukin-1β (IL-1β), IL-2, IL-4, IL-6 and so on in peripheral blood and exhaled breath condensate (EBC) before and after 'XEN' inhalation were measured.

RESULTS

45 minutes 'XEN' inhalation once decreased monocyte chemotactic protein 1 level in both COPD (564.70-451.51 pg/mL, P = 0.019) and asthma (386.39-332.76 pg/mL, P = 0.033) group, while decreased IL-8 level only in asthma group (5.25-4.49 pg/mL, P = 0.023). The level of EBC soluble cluster of differentiation-40 ligand in COPD group increased after inhalation (1.07-1.16 pg/mL, P = 0.031), while IL-4 and IL-6 levels in EBC were significantly lower after inhalation in the COPD (0.80-0.64 pg/mL, P = 0.025) and asthma (0.06-0.05 pg/mL, P = 0.007) group, respectively.

CONCLUSIONS

A single inhalation of hydrogen for 45 min attenuated inflammatory status in airways in patients with asthma and COPD.

Spatial and temporal analysis of human infection with avian influenza A(H7N9) virus in China, 2013

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Cerebrofacial venous metameric syndrome (CVMS)�3: Sturge-Weber syndrome with bilateral lymphatic/venous malformations of the mandible

We present a case of Sturge-Weber syndrome with a bilateral lymphatic/venous malformation of the mandible. Modern biology suggests an explanation for such a case. The classification of cerebrofacial venous metameric syndromes (CVMS) enables us to recognise this lesion as involving the most caudal of the cranial metamere (CVMS 3).

A mutated human tumor necrosis factor-alpha improves the therapeutic index in vitro and in vivo

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional cytokine that has cytotoxic, cytostatic and immunomodulatory effects on malignant tumors. However, clinical trials have revealed high systemic toxicity and this has hampered its utilization as an anti-cancer agent. In this study, a human TNF-alpha mutant was created and tested for its anti-tumor effects.

METHODS

The TNF mutant (recombinant mutated human TNF; rmhTNF) was prepared by protein engineering in which amino acids Pro, Ser and Asp at positions 8, 9 and 10 of TNF-alpha were substituted by Arg, Lys and Arg, and C terminal Leu157 was substituted by Phe, along with deletion of the first seven N-terminal amino acids. Prokaryotic expression recombinant vector pBV-mhTNF containing the PLPR promotor was constructed and transformed into E. coli DH5alpha. The rmhTNF was expressed in a partially soluble form in DH5alpha, purified from the supernatant of cell lysate by ammonia sulfate precipitation and two sequential chromatographic steps.

RESULTS

The purified rmhTNF was >95% pure by SDS-PAGE stained with silver and high-pressure size exclusion chromatography (SEC-HPLC). Its yield was about 1.22 mg/g wet cell paste. The mutant rmhTNF exhibited an approximately 50-fold increase in cytotoxicity relative to the wild-type rhTNF on the mouse fibroblast cell line L929 in a standard cytotoxicity test, and at least and at least 50 times higher LD50 as wild type rhTNF in mice. In vivo biological activity studies carried out on tumor cell transplanted mice and nude mice also showed a more effective cytotoxicity of rmhTNF than rhTNF.

DISCUSSION

These results suggest that rmhTNF has potential for developing an effective anti-tumor reagent for some tumors.