Shu Chuan Ho

Comparative proteomics of inhaled silver nanoparticles in healthy and allergen provoked mice

Background Silver nanoparticles (AgNPs) have been associated with the exacerbation of asthma; however, the immunological basis for the adjuvant effects of AgNPs is not well understood. Objective The aim of the study reported here was to investigate the allergic effects of AgNP inhalation using proteomic approaches. Methods Allergen provoked mice were exposed to 33 nm AgNPs at 3.3 mg/m3. Following this, bronchoalveolar lavage fluid (BALF) and plasma were collected to determine protein profiles. Results In total, 106 and 79 AgNP-unique proteins were identified in the BALF of control and allergic mice, respectively. Additionally, 40 and 26 AgNP-unique proteins were found in the plasma of control and allergic mice, respectively. The BALF and plasma protein profiles suggested that metabolic, cellular, and immune system processes were associated with pulmonary exposure to AgNPs. In addition, we observed 18 proteins associated with systemic lupus erythematosus that were commonly expressed in both control and allergic mice after AgNP exposure. Significant allergy responses were observed after AgNP exposure in control and allergic mice, as determined by ovalbumin-specific immunoglobulin E. Conclusion Inhaled AgNPs may regulate immune responses in the lungs of both control and allergic mice. Our results suggest that immunology is a vital response to AgNPs.

Neutrophil Elastase Represses IL-8/CXCL8 Synthesis in Human Airway Smooth Muscle Cells through Induction of NF-κB Repressing Factor

NF-κB repressing factor (NRF), a nuclear inhibitor of NF-κB, is constitutively expressed and is implicated in the basal silencing of specific NF-κB targeting genes, including IFN-β, IL-8/CXCL8, and iNOS. Little is known about the regulation of NRF and its role in response to stimuli. Airway smooth muscle (ASM) is a rich source of inflammatory mediators that may regulate the development and progression of airway inflammation. We have previously reported that NE activates NF-κB in primary human ASM (hASM), leading to induction of TGF-β1. In this study, we describe that, instead of inducing the NF-κB response gene IL-8/CXCL8, NE suppressed IL-8/CXCL8 release and mRNA expression in hASM cells. Transcriptional blockade studies using actinomycin D revealed a similar degradation rate of IL-8/CXCL8 mRNA in the presence or absence of NE, suggesting an involvement at the transcription level. Mechanistically, the NE repressive effect was mediated by inducing NRF, as shown by RT-PCR and Western blotting, which was subsequently recruited to the native IL-8/CXCL8 promoter leading to removal of RNA polymerase II from the promoter, as demonstrated by chromatin immunoprecipitation assays. Knockdown of NRF by small interfering RNA prevented NE-induced suppression of IL-8/CXCL8 expression. In contrast, NE did not induce NRF expression in A549 and Beas-2B cells, where NE only stimulates NF-κB activation and IL-8/CXCL8 induction. Forced expression of NRF in A549 cells by an NRF expression plasmid suppressed IL-8/CXCL8 expression. Hence, we describe a novel negative regulatory mechanism of NE-induced NRF, which is restricted to hASM and mediates the suppression of IL-8/CXCL8 expression.

Reduced nuclear factor-κB repressing factor: a link toward systemic inflammation in COPD

Chronic systemic inflammation is implicated in the systemic manifestations and, probably, the excess mortality risk of chronic obstructive pulmonary disease (COPD). The role of nuclear factor (NF)-&kgr;B repressing factor (NRF), a DNA-binding, protein-inhibiting NF-&kgr;B response gene, in human diseases has not been explored. We hypothesised that the NRF-negative regulatory mechanism is impaired in COPD peripheral blood mononuclear cells (PBMCs) leading to excessive interleukin (IL)-8/CXCL8 production. NRF expression, NF-&kgr;B activation, IL-8/CXCL8 release and intracellular oxidative stress were assessed in PBMCs of normal subjects and stable COPD patients. Primary PBMCs with NRF overexpression, NRF knockdown and exposure to H2O2 were used to elucidate the mechanisms. Stable COPD patients, especially those with severe COPD, showed decreased NRF expression, enhanced NF-&kgr;B activation and increased IL-8/CXCL8 release in PBMCs compared with normal subjects. This was associated with reduced NRF and increased RNA polymerase II occupancy at the IL-8/CXCL8 promoter. NRF knockdown enhanced IL-8/CXCL8 production in normal PBMCs, whilst NRF overexpression attenuated IL-8/CXCL8 production. Intracellular oxidative stress was increased in COPD PBMCs. H2O2-decreased NRF expression and -enhanced IL-8/CXCL8 production was augmented in COPD PBMCs. NRF expression is reduced in PBMCs of stable COPD patients, probably through oxidative stress, leading to increased production of IL-8/CXCL8 and potentially chronic systemic inflammation.

Mobile-phone-based home exercise training program decreases systemic inflammation in COPD: a pilot study

BackgroundModerate-intensity exercise training improves skeletal muscle aerobic capacity and increased oxidative enzyme activity, as well as exercise tolerance in COPD patients.MethodsTo investigate whether the home-based exercise training program can reduce inflammatory biomarkers in patients with COPD, twelve patients using mobile phone assistance and 14 with free walk were assessed by incremental shuttle walk test (ISWT), spirometry, strength of limb muscles, and serum C-reactive protein (CRP) and inflammatory cytokines.ResultsPatients in the mobile phone group improved their ISWT walking distance, with decrease in serum CRP after 2 months, and sustained at 6 months. Patients in the control group had no improvement. Serum IL-8 in the mobile phone group was significantly reduced at 2, 3 and 6 months after doing home exercise training compared to baseline. IL-6 and TNF-α were significantly elevated at 3 and 6 months in control group, while there were no changes in mobile phone group. The strength of limb muscles was significantly greater compared to baseline at 3 and 6 months in the mobile phone group.ConclusionsA mobile-phone-based system can provide an efficient home endurance exercise training program with improved exercise capacity, strength of limb muscles and a decrease in serum CRP and IL-8 in COPD patients. Decreased systemic inflammation may contribute to these clinical benefits. (Clinical trial registration No.: NCT01631019)

Matrix Metalloproteinase-1 Polymorphism (-1607G) and Disease Severity in Non-Cystic Fibrosis Bronchiectasis in Taiwan

Objectives Bronchiectasis is characterized by an irreversible dilatation of bronchi and is associated with lung fibrosis. MMP-1 polymorphism may alter its transcriptional activity, and differentially modulate bronchial destruction and lung fibrosis. Design To investigate the association of MMP-1 polymorphisms with disease severity in non-cystic fibrosis (CF) bronchiectasis patients, 51 normal subjects and 113 patients with bronchiectasis were studied. The associations between MMP-1 polymorphisms, lung function, and disease severity evaluated by high resolution computed tomography (HRCT) were analyzed. Results The frequency of MMP-1(-1607G) allele was significantly higher in patients with bronchiectasis than normal subjects (70.8% vs 45.1%, p<0.01). Forced expiratory volume in 1 second (FEV1) was decreased in bronchiectasis patients with 1G/1G (1.2±0.1 L, n = 14) and 1G/2G (1.3±0.1 L, n = 66) genotypes compared to the 2G/2G genotype (1.7±0.1 L, n = 33, p<0.01). Six minute walking distance was decreased in bronchiectasis patients with 1G/1G and 1G/2G compared to that of 2G/2G genotype. Disease severity evaluated by HRCT score significantly increased in bronchiectasis patients with 1G/1G and 1G/2G genotypes compared to that of 2G/2G genotype. Bronchiectasis patients with at least one MMP-1 (-1607G) allele showed increased tendency for hospitalization. Serum levels of pro-MMP-1, active MMP-1 and TGF-β1 were significantly increased in patients with bronchiectasis with 1G/1G and 1G/2G genotype compared with 2G/2G genotype or normal subjects. Under IL-1β stimulation, peripheral blood monocytes from subjects with 1G/2G or 1G/1G genotype secreted higher levels of TGF-β1compared to subjects with 2G/2G genotype. Conclusion This is the first report to address the influence of MMP-1 polymorphisms on lung function and airway destruction in non-CF bronchiectasis patients. Bronchiectasis patients with MMP-1(-1607G) polymorphism may be more vulnerable to permanent lung fibrosis or airway destruction due to the enhanced MMP-1 and TGF-β1 activity. Upregulated MMP-1 activity results in proteolytic destruction of matrix, and leads to subsequent fibrosis.

Inter-alpha-trypsin inhibitor heavy chain 4: A novel biomarker for environmental exposure to particulate air pollution in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease that is correlated with environmental stress. Particulate matter ≤10 μm (PM10) is considered to be a risk factor for COPD development; however, the effects of PM10 on the protein levels in COPD remain unclear. Fifty subjects with COPD and 15 healthy controls were recruited. Gene ontology analysis of differentially expressed proteins identified immune system process and binding as the most important biological process and molecular function, respectively, in the responses of PM10-exposed patients with COPD. Biomarkers for PM10 in COPD were identified and compared with the same in healthy controls and included proteoglycan 4 (PRG4), inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), and apolipoprotein F (APOF). PRG4 and ITIH4 were associated with a past 3-year PM10 exposure level. The receiver operating characteristic curve analysis showed that ITIH4 is a sensitive and specific biomarker for PM10 exposure (area under the curve [AUC] =0.690, P=0.015) compared with PRG4 (AUC =0.636, P=0.083), APOF (AUC =0.523, P=0.766), 8-isoprostane (AUC =0.563, P=0.405), and C-reactive protein (CRP; AUC =0.634, P=0.086). ITIH4 levels were correlated with CRP (r=0.353, P=0.005), suggesting that ITIH4 may be involved in an inflammatory mechanism. In summary, serum ITIH4 may be a PM10-specific biomarker in COPD and may be related to inflammation.

Dysfunction of methionine sulfoxide reductases to repair damaged proteins by nickel nanoparticles

BACKGROUND Protein oxidation is considered to be one of the main causes of cell death, and methionine is one of the primary targets of reactive oxygen species (ROS). However, the mechanisms by which nickel nanoparticles (NiNPs) cause oxidative damage to proteins remain unclear. OBJECTIVES The objective of this study is to investigate the effects of NiNPs on the methionine sulfoxide reductases (MSR) protein repairing system. METHODS Two physically similar nickel-based nanoparticles, NiNPs and carbon-coated NiNP (C-NiNPs; control particles), were exposed to human epithelial A549 cells. Cell viability, benzo(a)pyrene diolepoxide (BPDE) protein adducts, methionine oxidation, MSRA and B3, microtubule-associated protein 1A/1B-light chain 3 (LC3) and extracellular signal-regulated kinase (ERK) phosphorylation were investigated. RESULTS Exposure to NiNPs led to a dose-dependent reduction in cell viability and increased BPDE protein adduct production and methionine oxidation. The methionine repairing enzymatic MSRA and MSRB3 production were suppressed in response to NiNP exposure, suggesting the oxidation of methionine to MetO by NiNP was not reversed back to methionine. Additionally, LC3, an autophagy marker, was down-regulated by NiNPs. Both NiNP and C-NiNP caused ERK phosphorylation. LC3 was positively correlated with MSRA (r = 0.929, p < 0.05) and MSRB3 (r = 0.893, p < 0.05). CONCLUSIONS MSR was made aberrant by NiNP, which could lead to the dysfunction of autophagy and ERK phosphorylation. The toxicological consequences may be dependent on the chemical characteristics of the nanoparticles.

Chronic cough and obstructive sleep apnoea in a sleep laboratory-based pulmonary practice

BackgroundObstructive sleep apnoea (OSA) has recently been identified as a possible aetiology for chronic cough. The aim of this study was to compare the incidence of chronic cough between patients with and without OSA and the impact of continuous positive airway pressure (CPAP) treatment in resolving chronic cough.MethodsPatients referred to the sleep laboratory from January 2012 to June 2012 were retrospectively enrolled. Clinical data, treatment course and resolution of chronic cough were analysed. Specifically, gastro-oesophageal reflux (GERD), upper airway cough syndrome, asthma, apnoea-hypopnoea index and the impact of CPAP treatment on chronic cough were assessed.ResultsA total of 131 patients were reviewed. The incidence of chronic cough in the OSA group was significantly higher than the non-OSA group (39/99 (39.4%) vs. 4/32 (12.5%), p = 0.005). Both GERD and apnoea-hypopnoea index were significantly associated with chronic cough in univariate analysis. After multivariate logistic regression, GERD was the only independent factor for chronic cough. Moreover, the resolution of chronic cough was more significant in the OSA patients with CPAP treatment compared with those not receiving CPAP treatment (12/18 (66.7%) vs. 2/21 (9.5%), p = 0.010).ConclusionThe incidence of chronic cough was significantly higher in the OSA patients. In addition, CPAP treatment significantly improved chronic cough. Therefore, OSA may be a contributory factor to chronic cough.

Urinary neutrophil gelatinase-associated lipocalin is associated with heavy metal exposure in welding workers.

Metals cause nephrotoxicity with acute and/or chronic exposure; however, few epidemiological studies have examined impacts of exposure to metal fumes on renal injury in welding workers. In total, 66 welding workers and 12 office workers were recruited from a shipyard located in southern Taiwan. Urine samples from each subject were collected at the beginning (baseline) and end of the work week (1-week exposure). Personal exposure to PM2.5 was measured. The 8-h mean PM2.5 was 50.3 μg/m3 for welding workers and 27.4 μg/m3 for office workers. iTRAQs coupled with LC-MS/MS were used to discover the pathways in response to welding PM2.5 in the urine, suggesting that extracellular matrix (ECM)-receptor interactions are a critical mechanism. ECM-receptor interaction-related biomarkers for renal injury, kidney injury molecule (KIM)-1 and neutrophil gelatinase-associated lipocalin (NGAL), were significantly elevated in welding workers post-exposure, as well as were urinary Al, Cr, Mn, Fe, Co, and Ni levels. NGAL was more significantly associated with Al (r = 0.737, p < 0.001), Cr (r = 0.705, p < 0.001), Fe (r = 0.709, p < 0.001), and Ni (r = 0.657, p < 0.001) than was KIM-1, suggesting that NGAL may be a urinary biomarker for welding PM2.5 exposure. Nephrotoxicity (e.g., renal tubular injury) may be an emerging concern in occupational health.

Proteoglycan 4 is a diagnostic biomarker for COPD.

Introduction The measurement of C-reactive protein (CRP) to confirm the stability of COPD has been reported. However, CRP is a systemic inflammatory biomarker that is related to many other diseases. Objective The objective of this study is to discover a diagnostic biomarker for COPD. Methods Sixty-one subjects with COPD and 15 healthy controls (10 healthy non-smokers and 5 smokers) were recruited for a 1-year follow-up study. Data regarding the 1-year acute exacerbation frequency and changes in lung function were collected. CRP and the identified biomarkers were assessed in the validation COPD cohort patients and healthy subjects. Receiver operating characteristic values of CRP and the identified biomarkers were determined. A validation COPD cohort was used to reexamine the identified biomarker. Correlation of the biomarker with 1-year lung function decline was determined. Results Proteoglycan 4 (PRG4) was identified as a biomarker in COPD. The serum concentrations of PRG4 in COPD Global initiative for chronic Obstructive Lung Disease (GOLD) stages 1+2 and 3+4 were 10.29 ng/mL and 13.20 ng/mL, respectively; 4.99 ng/mL for healthy controls (P<0.05); and 4.49 ng/mL for healthy smokers (P<0.05). PRG4 was more sensitive and specific than CRP for confirming COPD severity and acute exacerbation frequency. There was no correlation between CRP and PRG4 levels, and PRG4 was negatively correlated with the 1-year change in predicted forced vital capacity percent (R2=0.91, P=0.013). Conclusion PRG4 may be a biomarker for identification of severity in COPD. It was related to the 1-year forced vital capacity decline in COPD patients.