Global map of SUMO function revealed by protein-protein interaction and genetic networks.

Systematic functional genomics approaches were used to map a network centered on the small ubiquitin-related modifier (SUMO) system. Over 250 physical interactions were identified using the SUMO protein as bait in affinity purification-mass spectrometry and yeast two-hybrid screens. More than 500 genes and 1400 synthetic genetic interactions were mapped by synthetic genetic array (SGA) analysis using eight different SUMO pathway query genes. The resultant global SUMO network highlights its role in 15 major biological processes and better defines functional relationships between the different components of the SUMO pathway. Using this information-rich resource, we have identified roles for the SUMO system in the function of the AAA ATPase Cdc48p, the regulation of lipid metabolism, localization of the ATP-dependent endonuclease Dna2p, and recovery from the DNA-damage checkpoint.

Evidence for positive selection on a number of MicroRNA regulatory interactions during recent human evolution.

MicroRNA (miRNA)-mediated gene regulation is of critical functional importance in animals and is thought to be largely constrained during evolution. However, little is known regarding evolutionary changes of the miRNA network and their role in human evolution. Here we show that a number of miRNA binding sites display high levels of population differentiation in humans and thus are likely targets of local adaptation. In a subset we demonstrate that allelic differences modulate miRNA regulation in mammalian cells, including an interaction between miR-155 and TYRP1, an important melanosomal enzyme associated with human pigmentary differences. We identify alternate alleles of TYRP1 that induce or disrupt miR-155 regulation and demonstrate that these alleles are selected with different modes among human populations, causing a strong negative correlation between the frequency of miR-155 regulation of TYRP1 in human populations and their latitude of residence. We propose that local adaptation of microRNA regulation acts as a rheostat to optimize TYRP1 expression in response to differential UV radiation. Our findings illustrate the evolutionary plasticity of the microRNA regulatory network in recent human evolution.

SH3 interactome conserves general function over specific form.

Src homology 3 (SH3) domains bind peptides to mediate protein-protein interactions that assemble and regulate dynamic biological processes. We surveyed the repertoire of SH3 binding specificity using peptide phage display in a metazoan, the worm Caenorhabditis elegans, and discovered that it structurally mirrors that of the budding yeast Saccharomyces cerevisiae. We then mapped the worm SH3 interactome using stringent yeast two-hybrid and compared it with the equivalent map for yeast. We found that the worm SH3 interactome resembles the analogous yeast network because it is significantly enriched for proteins with roles in endocytosis. Nevertheless, orthologous SH3 domain-mediated interactions are highly rewired. Our results suggest a model of network evolution where general function of the SH3 domain network is conserved over its specific form.

Anti-HMGB1 neutralizing antibody ameliorates neutrophilic airway inflammation by suppressing dendritic cell-mediated Th17 polarization.

We demonstrate that high mobility group box 1 protein (HMGB1) directs Th17 skewing by regulating dendritic cell (DC) function. First, our in vitro studies reveal that recombinant HMGB1 (rHMGB1) activates myeloid DCs to produce IL-23 in vitro, and rHMGB1-activated DCs prime naïve lymphocytes to produce the Th17 cytokine IL-17A. Second, we demonstrate that anti-HMGB1 neutralizing antibody attenuates HMGB1 expression, neutrophilic inflammation, airway hyperresponsiveness, and Th17-related cytokine secretion in vivo by using a murine model of neutrophilic asthma induced by ovalbumin (OVA) plus lipopolysaccharide (LPS). Furthermore, anti-HMGB1 neutralizing antibody decreases the number of Th17 cells in lung cells and suppresses the production of IL-23 by lung CD11C(+) APCs. Finally, we show that intranasal adoptive transfer of rHMGB1-activated DCs was sufficient to restore lung neutrophilic inflammation and the Th17 response in a DC-driven model of asthma, whereas the transfer of rHMGB1 plus anti-HMGB1-treated mDCs significantly reduced these inflammation phenotypes. These data suggest, for the first time, that HMGB1 drives the DC-polarized Th17-type response in allergic lung inflammation and that blocking HMGB1 may benefit the attenuation of neutrophilic airway inflammation in asthma.

Therapeutic TNF Inhibitors Exhibit Differential Levels of Efficacy in Accelerating Cutaneous Wound Healing.

Adalimumab but neither etanercept nor certolizumab-pegol has been reported to induce a wound-healing profile in vitro by regulating macrophage differentiation and matrix metalloproteinase expression, which may underlie the differences in efficacy between various TNF-α inhibitors in impaired wound healing in patients with hidradenitis suppurativa, a chronic inflammatory skin disease. To examine and compare the efficacy of various TNF inhibitors in cutaneous wound healing in vivo, a human TNF knock-in Leprdb/db mouse model was established to model the impaired cutaneous wound healing as seen in hidradenitis suppurativa. The vehicle group exhibited severe impairments in cutaneous wound healing. In contrast, adalimumab significantly accelerated healing, confirmed by both histologic assessment and a unique healing transcriptional profile. Moreover, adalimumab and infliximab showed similar levels of efficacy, but golimumab was less effective, along with etanercept and certolizumab-pegol. In line with histologic assessments, proteomics analyses from healing wounds exposed to various TNF inhibitors revealed distinct and differential wound-healing signatures that may underlie the differential efficacy of these inhibitors in accelerating cutaneous wound healing. Taken together, these data revealed that TNF inhibitors exhibited differential levels of efficacy in accelerating cutaneous wound healing in the impaired wound-healing model in vivo.

Exploiting the determinants of stochastic gene expression in Saccharomyces cerevisiae for genome-wide prediction of expression noise.

Gene regulation is a process with many steps allowing for stochastic biochemical reactions, which leads to expression noise-i.e., the cell-to-cell stochastic fluctuation in protein abundance. Such expression noise can give rise to drastically diverse phenotypes, even within isogenic cell populations. Although numerous biophysical approaches had been proposed to model the origin and propagation of expression noise in biological networks, these models essentially characterize the innate stochastic dynamics in gene regulation in a mechanistic way. In this work, by investigating expression noise in the context of yeast cellular networks, we place the biophysical formulism onto solid genetic ground. At the sequence level, we show that extremely noisy genes are highly conserved in their coding sequences. At the level of cellular networks where natural selection is manifested by the topological constraints, we show that genes with varying expression noise are modularly organized in the protein interaction network and are positioned orderly in the gene regulatory network. We demonstrate that these topological constraints are highly predictive of stochastic gene expression, with which we were able to confidently predict stochastic expression for more than 2,000 yeast genes whose expression noise was previously not known. We validated the predictions by high-content cell imaging. Our approach makes feasible genome-wide prediction of stochastic gene expression, and such predictability in turn suggests that expression noise is an evolvable genetic trait.

An empirical framework for binary interactome mapping.

Several attempts have been made to systematically map protein-protein interaction, or 'interactome', networks. However, it remains difficult to assess the quality and coverage of existing data sets. Here we describe a framework that uses an empirically-based approach to rigorously dissect quality parameters of currently available human interactome maps. Our results indicate that high-throughput yeast two-hybrid (HT-Y2H) interactions for human proteins are more precise than literature-curated interactions supported by a single publication, suggesting that HT-Y2H is suitable to map a significant portion of the human interactome. We estimate that the human interactome contains approximately 130,000 binary interactions, most of which remain to be mapped. Similar to estimates of DNA sequence data quality and genome size early in the Human Genome Project, estimates of protein interaction data quality and interactome size are crucial to establish the magnitude of the task of comprehensive human interactome mapping and to elucidate a path toward this goal.

Bayesian modeling of the yeast SH3 domain interactome predicts spatiotemporal dynamics of endocytosis proteins.

SH3 domains are peptide recognition modules that mediate the assembly of diverse biological complexes. We scanned billions of phage-displayed peptides to map the binding specificities of the SH3 domain family in the budding yeast, Saccharomyces cerevisiae. Although most of the SH3 domains fall into the canonical classes I and II, each domain utilizes distinct features of its cognate ligands to achieve binding selectivity. Furthermore, we uncovered several SH3 domains with specificity profiles that clearly deviate from the two canonical classes. In conjunction with phage display, we used yeast two-hybrid and peptide array screening to independently identify SH3 domain binding partners. The results from the three complementary techniques were integrated using a Bayesian algorithm to generate a high-confidence yeast SH3 domain interaction map. The interaction map was enriched for proteins involved in endocytosis, revealing a set of SH3-mediated interactions that underlie formation of protein complexes essential to this biological pathway. We used the SH3 domain interaction network to predict the dynamic localization of several previously uncharacterized endocytic proteins, and our analysis suggests a novel role for the SH3 domains of Lsb3p and Lsb4p as hubs that recruit and assemble several endocytic complexes.

[The expressions of nerve growth factor and its tyrosine kinase A receptor on alveolar macrophages in a rat model of chronic obstructive pulmonary disease].

OBJECTIVE: To observe the expressions of nerve growth factor (NGF) and its tyrosine kinase A (TrkA) receptor on alveolar macrophage in a rat model of chronic obstructive pulmonary disease (COPD). METHODS: Forty healthy male SD rats were randomly divided into a control group and a COPD group. The COPD model was established by exposing the rats to cigarette smoke for 6 months, and lung function changes were measured. Lung histopathological changes were detected by HE staining. The expression of NGF protein in the supernatant of alveolar macrophage (AM) culture medium was detected by ELISA. Confocal microscopy was used to identify the separation and purification of AM from bronchoalveolar lavage fluid, and to detect semi-quantitatively the expression of TrkA receptor on AM. NGF and its TrkA receptor at the mRNA level were evaluated by real-time PCR. The differences among groups were calculated by one way ANOVA, and comparison between groups was made by t test. RESULTS: Significant decrease of pulmonary compliance [(0.15 ± 0.03) ml/cm H(2)O (1 cm H2O = 0.098 kPa)] and minute ventilation [(0.045 ± 0.004) L], and significant increase of airway resistance [(0.038 ± 0.004) cm H2O×L(-1)×s(-1)] were found in the COPD group compared with the control group [(0.42 ± 0.05) ml/cm H2O and (0.102 ± 0.010) L and (0.016 ± 0.002) cm H2O×L(-1)×s(-1), t = 9.46 - 12.99, respectively, all P < 0.01]. Alveolar wall thinning, alveolar septa breakdown, alveolar enlargement and emphysema were significant in the COPD rats. The expression of NGF protein in the supernatant of AM culture medium was enhanced in the COPD group [(3.79 ± 1.52) ng/L] compared with the controls [(0.94 ± 0.27) ng/L, t = 4.13, P < 0.05]. Mean fluorescence intensity of TrkA protein on AM in the COPD group (19.5 ± 1.5) was higher than that in the control group (11.2 ± 1.9, t = 7.95, P < 0.05). The expressions of NGF and TrkA at mRNA level in the COPD group (24.8 ± 6.0 and 9.0 ± 3.3) were increased compared with the control group (1.0 ± 0.2 and 1.0 ± 0.4, t = 8.48 and 5.16, all P < 0.05). CONCLUSIONS: The expressions of NGF and its TrkA receptor on AM in COPD group were increased, indicating that NGF and its TrkA receptor might be involved in the pathogenesis of COPD mediated by AM.

Arrhythmogenic mechanisms of interleukin-6 combination with hydroxychloroquine and azithromycin in inflammatory diseases.

Inflammatory diseases including COVID-19 are associated with a cytokine storm characterized by high interleukin-6 (IL-6) titers. In particular, while recent studies examined COVID-19 associated arrhythmic risks from cardiac injury and/or from pharmacotherapy such as the combination of azithromycin (AZM) and hydroxychloroquine (HCQ), the role of IL-6 per se in increasing the arrhythmic risk remains poorly understood. The objective is to elucidate the electrophysiological basis of inflammation-associated arrhythmic risk in the presence of AZM and HCQ. IL-6, AZM and HCQ were concomitantly administered to guinea pigs in-vivo and in-vitro. Electrocardiograms, action potentials and ion-currents were analyzed. IL-6 alone or the combination AZM + HCQ induced mild to moderate reduction in heart rate, PR-interval and corrected QT (QTc) in-vivo and in-vitro. Notably, IL-6 alone was more potent than the combination of the two drugs in reducing heart rate, increasing PR-interval and QTc. In addition, the in-vivo or in-vitro combination of IL-6 + AZM + HCQ caused severe bradycardia, conduction abnormalities, QTc prolongation and asystole. These electrocardiographic abnormalities were attenuated in-vivo by tocilizumab (TCZ), a monoclonal antibody against IL-6 receptor, and are due in part to the prolongation of action potential duration and selective inhibition of Na+, Ca2+ and K+ currents. Inflammation confers greater risk for arrhythmia than the drug combination therapy. As such, in the setting of elevated IL-6 during inflammation caution must be taken when co-administering drugs known to predispose to fatal arrhythmias and TCZ could be an important player as a novel anti-arrhythmic agent. Thus, identifying inflammation as a critical culprit is essential for proper management.

Interleukin-6 Elevation Is a Key Pathogenic Factor Underlying COVID-19-Associated Heart Rate-Corrected QT Interval Prolongation.

Background: Heart rate-corrected QT interval (QTc) prolongation is prevalent in patients with severe coronavirus disease 2019 (COVID-19) and is associated with poor outcomes. Recent evidence suggests that the exaggerated host immune-inflammatory response characterizing the disease, specifically interleukin-6 (IL-6) increase, may have an important role, possibly via direct effects on cardiac electrophysiology. The aim of this study was to dissect the short-term discrete impact of IL-6 elevation on QTc in patients with severe COVID-19 infection and explore the underlying mechanisms. Methods: We investigated the following mechanisms: (1) the QTc duration in patients with COVID-19 during the active phase and recovery, and its association with C-reactive protein (CRP) and IL-6 levels; (2) the acute impact of IL-6 administration on QTc in an in vivo guinea pig model; and (3) the electrophysiological effects of IL-6 on ventricular myocytes in vitro. Results: In patients with active severe COVID-19 and elevated IL-6 levels, regardless of acute myocardial injury/strain and concomitant QT-prolonging risk factors, QTc was significantly prolonged and rapidly normalized in correlation with IL-6 decrease. The direct administration of IL-6 in an in vivo guinea pig model acutely prolongs QTc duration. Moreover, ventricular myocytes incubated in vitro with IL-6 show evident prolongation in the action potential, along with significant inhibition in the rapid delayed rectifier potassium current (IKr). Conclusion: For the first time, we demonstrated that in severe COVID-19, systemic inflammatory activation can per se promote QTc prolongation via IL-6 elevation, leading to ventricular electric remodeling. Despite being transitory, such modifications may significantly contribute to arrhythmic events and associated poor outcomes in COVID-19. These findings provide a further rationale for current anti-inflammatory treatments for COVID-19, including IL-6-targeted therapies.

A specificity map for the PDZ domain family.

PDZ domains are protein-protein interaction modules that recognize specific C-terminal sequences to assemble protein complexes in multicellular organisms. By scanning billions of random peptides, we accurately map binding specificity for approximately half of the over 330 PDZ domains in the human and Caenorhabditis elegans proteomes. The domains recognize features of the last seven ligand positions, and we find 16 distinct specificity classes conserved from worm to human, significantly extending the canonical two-class system based on position -2. Thus, most PDZ domains are not promiscuous, but rather are fine-tuned for specific interactions. Specificity profiling of 91 point mutants of a model PDZ domain reveals that the binding site is highly robust, as all mutants were able to recognize C-terminal peptides. However, many mutations altered specificity for ligand positions both close and far from the mutated position, suggesting that binding specificity can evolve rapidly under mutational pressure. Our specificity map enables the prediction and prioritization of natural protein interactions, which can be used to guide PDZ domain cell biology experiments. Using this approach, we predicted and validated several viral ligands for the PDZ domains of the SCRIB polarity protein. These findings indicate that many viruses produce PDZ ligands that disrupt host protein complexes for their own benefit, and that highly pathogenic strains target PDZ domains involved in cell polarity and growth.

ITSN-1 controls vesicle recycling at the neuromuscular junction and functions in parallel with DAB-1.

Intersectins (Itsn) are conserved EH and SH3 domain containing adaptor proteins. In Drosophila melanogaster, ITSN is required to regulate synaptic morphology, to facilitate efficient synaptic vesicle recycling and for viability. Here, we report our genetic analysis of Caenorhabditis elegans intersectin. In contrast to Drosophila, C. elegans itsn-1 protein null mutants are viable and display grossly normal locomotion and development. However, motor neurons in these mutants show a dramatic increase in large irregular vesicles and accumulate membrane-associated vesicles at putative endocytic hotspots, approximately 300 nm from the presynaptic density. This defect occurs precisely where endogenous ITSN-1 protein localizes in wild-type animals and is associated with a significant reduction in synaptic vesicle number and reduced frequency of endogenous synaptic events at neuromuscular junctions (NMJs). ITSN-1 forms a stable complex with EHS-1 (Eps15) and is expressed at reduced levels in ehs-1 mutants. Thus, ITSN-1 together with EHS-1, coordinate vesicle recycling at C. elegans NMJs. We also found that both itsn-1 and ehs-1 mutants show poor viability and growth in a Disabled (dab-1) null mutant background. These results show for the first time that intersectin and Eps15 proteins function in the same genetic pathway, and appear to function synergistically with the clathrin-coat-associated sorting protein, Disabled, for viability.

LncRNA GMDS-AS1 inhibits lung adenocarcinoma development by regulating miR-96-5p/CYLD signaling.

According to the global cancer statistic, lung cancer is one of the most dangerous tumors, which poses a serious threat to human health. Exploration the mechanism of lung cancer and new targeted therapeutic measures is always the hot topic. Long noncoding RNA (lncRNA) is an important factor affecting the development of tumors. However, the research on the mechanism of lncRNA in the progress of lung cancer needs to be further expanded. In this study, we found that the expression of lncRNA GMDS-AS1 was significantly reduced in lung adenocarcinoma (LUAD) tissues and cells. Upregulated GMDS-AS1 can significantly inhibit the proliferation of LUAD cells and promote cell apoptosis in vitro and in vivo. The results indicate that GMDS-AS1 acts as a tumor suppressor gene to affect the development of LUAD. Further studies revealed that GMDS-AS1 is a target gene of miR-96-5p, and GMDS-AS1 regulates proliferation and apoptosis of LUAD cells in association with miR-96-5p. In addition, we also confirmed that CYLD lysine 63 deubiquitinase (CYLD) is also a target gene of miR-96-5p. Through various validations, we confirmed that GMDS-AS1 can act as a ceRNA to upregulate the expression of CYLD by sponging miR-96-5p. Moreover, the intervention of GMDS-AS1/miR-96-5p/CYLD network can regulate the proliferation and apoptosis of LUAD cells. In this study, we revealed that the GMDS-AS1/miR-96-5p/CYLD network based on ceRNA mechanism plays an important role in the development of LUAD and provides a new direction and theoretical basis for targeted therapy of LUAD.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in the diagnosis of benign pulmonary lesions in sarcoidosis.

BACKGROUND: Many benign pulmonary lesions, especially sarcoidosis, are metabolically active and are indistinguishable from lung cancer using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging. This study sought to analyze the 18F-FDG PET/CT imaging features of benign pulmonary lesions and to improve the differential diagnosis of benign pulmonary lesions by 18F-FDG PET/CT imaging. METHODS: One hundred and thirteen patients with benign pulmonary lesions were studied retrospectively. Each patient underwent an 18F-FDG PET/CT scan. All cases were identified by pathology, diagnostic therapy or follow-up. The maximum standardized uptake value (SUVmax) was calculated for each pulmonary lesion. RESULTS: According to the final results, the benign pulmonary lesions were classified as inflammatory lesions (n=77) and granulomas (n=36) by histopathological diagnoses. The SUVmax of inflammatory lesions and granulomas were both high (4.55±2.77 and 6.81±3.96, respectively; P<0.05). When the benign pulmonary lesions were classified by clinical diagnoses, the SUVmax of sarcoidosis was significantly different from other diseases (15.12±5.67; P<0.01). CONCLUSIONS: Inflammatory lesions and granulomas show moderate or high FDG uptake on 18F-FDG PET/CT, but granulomas have higher values. 18F-FDG PET/CT appeared to have a higher SUVmax for the differential diagnosis of sarcoidosis and benign pulmonary lesions.

TGF-ß1 stimulates epithelial-mesenchymal transition mediated by ADAM33.

The present study aimed to determine the effects of transforming growth factor (TGF)-ß1 on disintegrin and metalloproteinase domain-containing protein 33 (ADAM33) expression in airway epithelial cells in order to investigate the association between ADAM33 expression and TGF-ß1-induced epithelial to mesenchymal transition (EMT), and to further explore the mechanisms underlying the role of ADAM33 in airway remodeling in asthma. The human bronchial epithelial cell line HBE was transfected with small interfering RNA targeting ADAM33 (siADAM33) and treated with different concentrations of TGF-ß1 (10, 20 or 30 ng/ml), while untransfected cells were used as controls. At 72 h after treatment, cellular morphology and immunohistochemical staining were observed under a microscope. The protein and mRNA expression levels of ADAM33 and the EMT markers E-cadherin and vimentin were detected by western blot analysis and reverse-transcription quantitative polymerase chain reaction, respectively. In addition, a correlation analysis of ADAM33 expression and E-cadherin/vimentin expression was performed. A wound healing migration assay and a cell invasion assay were also performed. The results of the cellular morphology, migration and invasion studies suggested that TGF-ß1 treatment induced typical EMT changes in HBE cells. In addition, treatment with various concentrations of TGF-ß1 significantly increased the protein and mRNA expression levels of ADAM33 and vimentin compared with those in untreated cells. TGF-ß1 treatment also decreased the protein and mRNA expression levels of E-cadherin in a dose-dependent manner. By contrast, transfection with siADAM33 promoted the protein expression of E-cadherin and decreased the protein expression of vimentin. Furthermore, ADAM33 and E-cadherin expression levels exhibited a significant negative correlation, whereas ADAM33 and vimentin were positively correlated. In conclusion, the results suggested that TGF-ß1 enhances ADAM33 expression in airway epithelial cells, and that ADAM33 induces the EMT of airway epithelial cells, thus participating in airway remodeling in asthma.

[Metalloproteinase-9/tissue inhibitor of metalloproteinase-1 in induced sputum in patients with asthma and chronic obstructive pulmonary disease and their relationship to airway inflammation and airflow limitation].

OBJECTIVE: To investigate the levels of metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in induced sputum in patients with asthma and chronic obstructive pulmonary disease (COPD), and its relationship to the number of inflammation cells and lung function. METHODS: Fourteen patients with asthma in remission stages, 12 patients with stable COPD and 10 normal control subjects were included in this study. Lung function was measured. Induced sputum was obtained and processed for cell differential and the supernatant was assayed for the concentrations of interleukin-4 (IL-4), MMP-9 and TIMP-1 by enzyme-linked immunosorbent assay (ELISA). RESULTS: The percentage of eosinophils in induced sputum in asthmatics (0.181 +/- 0.067) was significantly higher than that in normal control subjects (0.007 +/- 0.005) and in COPD (0.042 +/- 0.017, F = 4.32, P < 0.05). The percentage of neutrophils in induced sputum in patients with COPD (0.500 +/- 0.101) was significantly higher than that in asthmatics (0.30 +/- 0.07) and in normal control subjects (0.26 +/- 0.06, F = 4.13, P < 0.05). The concentrations of IL-4 in asthmatics, COPD and normal control subjects [respectively, (19 +/- 7) x 10(-3) g/L, (14 +/- 6) x 10(-3) g/L, (11 +/- 4) x 10(-3) g/L] did not show significant difference (F = 1.56, all P > 0.05) and did not correlate with the number of eosinophils (r = 0.33, 0.11, 0.19, all P > 0.05) and neutrophil (r = 0.25, 0.39, 0.40, all P > 0.05) and FEV(1) values (predicted r = 0.21, 0.35, 0.17, all P > 0.05). The concentrations of MMP-9 and TIMP-1 in induced sputum in asthmatics [(15.9 +/- 6.0) g/L, (19.8 +/- 8.5) g/L, respectively] and COPD [(13.4 +/- 5.1) g/L, (16.7 +/- 7.6) g/L, respectively] were significantly higher than those in normal control subjects [(1.8 +/- 1.1) g/L, (1.3 +/- 0.9) g/L, respectively] (F = 2.99, 4.22, respectively, all P < 0.05). Increased concentration of MMP-9 correlated positively with the percentage of eosinophils in asthmatics (r = 0.71, P < 0.05) and with the percentage of neutrophils in COPD (r = 0.59, P < 0.05), but did not correlate with FEV(1) values (predicted r = 0.22, 0.16, all P > 0.05) and FEV(1)/FVC (r = 0.25, 0.30, all P > 0.05). Increased concentration of TIMP-1 did not correlate with the number of eosinophils (r = 0.27, 0.31, all P > 0.05) and neutrophil (r = 0.20, 0.35, all P > 0.05) in asthmatics and COPD, but correlated inversely with FEV(1) values (predicted, respectively, r = -0.58, -0.62, all P < 0.05). The ratio of MMP-9/TIMP-1 was significantly lower in asthmatics 0.8 +/- 0.7 and COPD 0.8 +/- 0.6 than that in normal control subjects (1.5 +/- 0.6, F = 3.70, P < 0.05). The ratio was not statistically different between asthmatics and COPD (F = 1.78, P > 0.05). In asthmatics and COPD patients, the ratio of MMP-9/TIMP-1 in induced sputum correlated positively with FEV(1%) (respectively, r = 0.56, 0.61, all P < 0.05). CONCLUSION: An imbalance between MMP-9 and TIMP-1 in induced sputum in asthmatics and COPD is associated with airway inflammation and airflow limitation, which may play a role in the pathogenesis of extracellular matrix remodeling and airflow limitation.

HMGB1 mediates Aspergillus fumigatus-induced inflammatory response in alveolar macrophages of COPD mice via activating MyD88/NF-κB and syk/PI3K signalings.

The incidence and mortality of Aspergillus fumigatus (A. fumigatus) infected chronic obstructive pulmonary disease (COPD) patients are increasing. HMGB1, which mediates inflammatory response, is increased in COPD patients. However, the role and mechanism of HMGB1 in A. fumigatus-infected alveolar macrophages of COPD mice remain unknown. Alveolar macrophages isolated from COPD mice were infected with A. fumigatus conidia and then HMGB1 expression was assayed. The levels of pro-inflammatory cytokines, which was confirmed by TLR2/4 or Dectin-1 siRNA, RAGE, Dectin-1, and TLR2/4 levels were assayed after HMGB1 knockdown. The effects of HMGB1 on MyD88/NF-κB and syk/PI3K signaling pathways were explored with PDTC (NF-κB inhibitor) and R406 (syk inhibitor). The potential role of HMGB1 was also confirmed in A. fumigatus-infected COPD mice. HMGB1 expression was increased in A. fumigatus-infected COPD alveolar macrophages. The levels of pro-inflammatory cytokines induced in A. fumigatus-infected COPD but not control alveolar macrophages were reduced by HMGB1, TLR2/4 or Dectin-1 siRNA. The expression of Dectin-1 and TLR2/4, but not RAGE was decreased by HMGB1 siRNA. The expression of MyD88, p-p65, p-syk, and PI3K was decreased and IκB increased by HMGB1 knockdown. PDTC and R406 showed the similar effects as HMGB1 siRNA on levels of pro-inflammatory cytokines. The expression of HMGB1, TNF-α, IL-1ß, TLR2/4 and Dectin-1, and the activation of MyD88/NF-κB and syk/PI3K signalings in mice were consistent with the in vitro study. In conclusion, HMGB1 is responsible for A. fumigatus-induced inflammatory response in COPD alveolar macrophage via Dectin-1 and TLR2/4 receptor through activating MyD88/NF-κB and syk/PI3K signalings.