Shih-Lung Cheng

Genetic polymorphism of epoxide hydrolase and glutathione S-transferase in COPD

Genetic susceptibility to the development of chronic obstructive pulmonary disease (COPD) might depend on variation in the activities of enzymes that detoxify cigarette smoke products, such as microsomal epoxide hydrolase (mEPHX) and glutathione S-transferase (GST). It was investigated whether polymorphisms in these genes had any association with susceptibility to COPD and COPD severity. The genotypes of 184 patients with COPD and 212 control subjects were determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis of the mEPHX, GSTM1, GSTT1 and GSTP1 genes. All subjects were smokers or exsmokers. The proportion of GSTM1-null genotypes was significantly higher in patients with COPD than in control subjects (61.4 versus 42.5%). No differences were observed in the frequency of polymorphic genotypes for mEPHX, GSTT1 and GSTP1. During combined analysis of genetic polymorphisms for mEPHX, GSTM1 and GSTP1, it was found that there are strong indicators for susceptibility to COPD (genotype combination with at least one mutant mEPHX exon‐3 allele (histidine 113), GSTM1 null and homozygous for the GSTP1 isoleucine 105 allele). The frequencies of homozygous mutant alleles of mEPHX exon 3 and the GSTM1-null genotype were significantly higher in patients with severe COPD (forced expiratory volume in one second of <35% of the predicted value). It is proposed that the combination of genetic variants including at least one mutant microsomal epoxide hydrolase exon‐3 allele and glutathione S-transferase M1-null and homozygous isoleucine 105 glutathione S-transferase P1 genotypes are significant indicators of susceptibility to chronic obstructive pulmonary disease in the Taiwanese population. In addition, the homozygous variant of microsomal epoxide hydrolase exon 3 and the glutathione S-transferase M1-null genotype are independent risk factors for developing severe chronic obstructive pulmonary disease.

Polymorphism of the angiotensin-converting enzyme gene affects the outcome of acute respiratory distress syndrome.

Objective:There has been increasing evidence that angiotensin II may play an important role in the pathogenesis and in the evolution of acute lung injury. It was therefore hypothesized that polymorphisms of the angiotensin-converting enzyme gene affects the risk and outcome of acute respiratory distress syndrome (ARDS). Design:Prospective, observational study. Patients and Settings:The ARDS group consisted of 101 patients treated at the medical intensive care unit; the control groups consisted of 138 “at-risk” patients treated at the medical intensive care unit due to acute respiratory failure but did not meet the ARDS criteria throughout the hospital course, and 210 non–at-risk subjects. Intervention:None. Measurements and Main Results:The ARDS patients and control subjects were genotyped for the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme gene. Association of the polymorphism and the risk and the outcome of ARDS was analyzed. There was no significant difference in the frequencies of the genotypes between the ARDS, at-risk, and non–at-risk groups. The 28-day mortality rates were significantly different between the three angiotensin-converting enzyme genotypes (42%, 65%, and 75% for II, ID, and DD, respectively; p = .036). Survival analysis showed that the II genotype favorably affected 28-day survival (hazard ratio, 0.46; 95% confidence interval, 0.26–0.81; p = .007), whereas ARDS caused by hospital-acquired pneumonia had a negative effect (hazard ratio, 2.34; 95% confidence interval, 1.25–4.40; p = .008). The II genotype (hazard ratio, 0.53; 95% confidence interval, 0.32–0.87; p = .012) and ARDS caused by hospital-acquired pneumonia (hazard ratio, 2.13; 95% confidence interval, 1.24–3.68; p = .006) were also significant prognostic factors for the in-hospital mortality. Conclusions:The angiotensin-converting enzyme I/D polymorphism is a significant prognostic factor for the outcome of ARDS. Patients with the II genotype have a significantly better chance of survival. This study did not show an increased risk for ARDS in Chinese patients with the D allele.

Increased expression of placenta growth factor in COPD.

Background: Vascular endothelial growth factor (VEGF) and its receptor may have an important role in the pathogenesis of emphysema. The effect of another angiogenic factor, placenta growth factor (PlGF), in chronic obstructive pulmonary disease (COPD) is unknown. Methods: The serum levels of VEGF and PlGF in patients with COPD (n = 184), smokers (n = 212) and non-smokers (n = 159) and the bronchoalveolar lavage (BAL) fluid levels of VEGF and PlGF in another group (20 patients with COPD, 18 controls) were measured. In vitro cell culture experiments were performed to investigate the effect of PlGF on VEGF. Results: The mean (SE) serum levels of PlGF were significantly higher in patients with COPD than in controls (27.1 (7.4) pg/ml vs 12.3 (5.1) pg/ml in smokers and 10.8 (6.3) pg/ml in non-smokers, p = 0.005). The levels of PlGF in BAL fluid were also significantly higher in patients with COPD than in controls (45.7 (12.3) pg/ml vs 23.9 (7.6) pg/ml, p = 0.005), associated with an increase in the cytokines tumour necrosis factor-α (TNF-α) and interleukin-8 (IL-8). In patients with COPD the levels of PlGF correlated inversely with forced expiratory volume in 1 s (FEV1) in serum (r = −0.59, p = 0.002) and in BAL fluid (r = −0.51, p = 0.001). While the serum levels of VEGF were the same in patients with COPD and controls, the BAL fluid levels were significantly lower in patients with COPD than in controls (127.5 (30.1) pg/ml vs 237.8 (36.1) pg/ml, p = 0.002). In cultured bronchial epithelial cells, proinflammatory cytokines induced an increase in the protein expression of both PlGF and VEGF. Continuous concomitant treatment with PlGF, TNF-α and IL-8 stimulation reduced VEGF expression and induced cell death. This phenomenon was suppressed by VEGF receptor inhibitor (CBO-P11). Conclusions: The serum and BAL fluid levels of PlGF are increased in patients with COPD and are inversely correlated with FEV1. Concomitant treatment with PlGF, TNF-α and IL-8 causes detrimental effects on airway epithelial cells. These data suggest that bronchial epithelial cells can express PlGF, which may contribute to the pathogenesis of COPD.

Adsorption of Pb(II) and Cu(II) metal ions on functionalized large-pore mesoporous silica

Abstract Adsorption of copper and lead ions in aqueous solutions onto large-pore mesoporous silica materials functionalized with amino and mercapto groups and those with different morphologies including fiber-like, rod-like, and platelet was studied. The synthesized materials were characterized by techniques such as X-ray powder diffraction, nitrogen adsorption–desorption isotherms, scanning electron microscopy, and infrared spectra. Batch experiments were conducted to determine the adsorption processes. The equilibrium adsorption data agreed with Langmuir isotherms and revealed that four amino groups were required to form a stable surface complex with copper ions. Results indicated that initial adsorption rate onto platelet mesoporous adsorbent was rapid and faster than that of rod-like and fibrous morphologies due to its short channeling pores. Thiol-functionalized mesoporous silica adsorbents of all the morphologies have a better affinity for Pb2+ than the amino-mesoporous silica. In contrast, amino-mesoporous silica has a stronger affinity for Cu2+ compared to thiol-mesoporous silica. The optimal Pb2+ uptake on thiol-mesoporous silica was in solution with pH in 2–6, while the highest Cu2+ uptake on amino-mesoporous silica was at pH 5.

Increased serum placenta growth factor level is significantly associated with progression, recurrence and poor prognosis of oral squamous cell carcinoma

We recently found that the expression of placenta growth factor (PlGF) in oral squamous cell carcinoma (OSCC) specimens is correlated with the progression and prognosis of OSCC. In this study, serum samples were obtained from 72 OSCC patients before and 3 months after surgical cancer excision and from 30 normal controls. Serum PlGF levels were determined by enzyme-linked immunosorbent assay (ELISA). The mean serum PlGF levels were significantly higher in pre-surgery OSCC patients than in normal controls (19.1±10.7 vs. 10.1±4.5, P<0.001). Serum PlGF levels dropped to near the normal control levels after surgical cancer removal. Higher pre-surgery serum PlGF levels were significantly associated with larger tumor size (P=0.015), positive lymph node metastasis (P=0.001), more advanced clinical stages (P=0.002), and loco-regional recurrence (P=0.037). The serum PlGF level was identified as an independent unfavorable prognosis factor by multivariate Cox regression analyses (P=0.014). Kaplan-Meier curve showed that OSCC patients with a higher serum PlGF level had a significantly poorer cumulative recurrence-free survival than those with a lower serum PlGF level (log-rank test, P=0.009). When we used the serum PlGF level of 19.1 pg/ml (mean normal control value plus 2 standard deviations) as a cutoff point, the sensitivity, specificity, and positive predictive value for tumor recurrence was 80%, 56% and 78%, respectively. We conclude that the serum PlGF level may be a valuable biomarker for prediction of therapeutic effect, progression, recurrence and prognosis of OSCC.

Elastase induced lung epithelial cell apoptosis and emphysema through placenta growth factor

Chronic pulmonary obstructive disease (COPD) is the fourth leading cause of death worldwide, however, the pathogenic factors and mechanisms are not fully understood. Pulmonary emphysema is one of the major components of COPD and is thought to result from oxidative stress, chronic inflammation, protease–antiprotease imbalance and lung epithelial (LE) cell apoptosis. In our previous studies, COPD patients were noted to have higher levels of placenta growth factor (PlGF) in serum and bronchoalveolar lavage fluid than controls. In addition, transgenic mice overexpressing PlGF developed pulmonary emphysema and exposure to PlGF in LE cells induced apoptosis. Furthermore, intratracheal instillation of porcine pancreatic elastase (PPE) on to PlGF wild type mice induced emphysema, but not in PlGF knockout mice. Therefore, we hypothesized that PPE generates pulmonary emphysema through the upregulation of PlGF expression in LE cells. The elevation of PlGF then leads to LE cell apoptosis. In the present study, we investigated whether PPE induces PlGF expression, whether PlGF induces apoptosis and whether the downstream mechanisms of PlGF are related to LE cell apoptosis. We found that PPE increased PlGF secretion and expression both in vivo and in vitro. Moreover, PlGF-induced LE cell apoptosis and PPE-induced emphysema in the mice were mediated by c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) pathways. Given these findings, we suggest that the increase in PlGF and PlGF-induced JNK and p38 MAPK pathways contribute to PPE-induced LE cell apoptosis and emphysema. Regulatory control of PlGF and agents against its downstream signals may be potential therapeutic targets for COPD.

Successful Treatment of Pulmonary Hemorrhage Associated with Leptospirosis and Scrub Typhus Coinfection by Early Plasma Exchange

Leptospirosis and scrub typhus coinfections have been reported in up to 41% of agricultural workers with acute leptospirosis in Thailand, but only sporadically in Taiwan. Because of the nonspecific clinical presentations, it is difficult to differentiate patients with coinfections from leptospirosis alone. However, failure to identify coinfection may lead to mortality if inappropriate antibiotics are used. We report a 31-year-old man coinfected with leptospirosis and scrub typhus, which manifested as diffuse alveolar hemorrhage and acute renal failure mimicking pulmonary-renal syndrome. The patient was treated by early plasma exchange and a 7-day course of moxifloxacin therapy. Both pulmonary hemorrhage and hypoxemia resolved substantially on the 4th day of hospitalization. He had a complete recovery from the disease after 6 weeks of hospitalization.

Elastase induces lung epithelial cell autophagy through placental growth factor: A new insight of emphysema pathogenesis

Chronic obstructive pulmonary disease (COPD) is a devastating disease, which is associated with increasing mortality and morbidity. Therefore, there is a need to clearly define the COPD pathogenic mechanism and to explore effective therapies. Previous studies indicated that cigarette smoke (CS) induces autophagy and apoptosis in lung epithelial (LE) cells. Excessive ELANE/HNE (elastase, neutrophil elastase), a factor involved in protease-antiprotease imbalance and the pathogenesis of COPD, causes LE cell apoptosis and upregulates the expression of several stimulus-responsive genes. However, whether or not elastase induces autophagy in LE cell remains unknown. The level of PGF (placental growth factor) is higher in COPD patients than non-COPD controls. We hypothesize that elastase induces PGF expression and causes autophagy in LE cells. In this study, we demonstrated that porcine pancreatic elastase (PPE) induced PGF expression and secretion in LE cells in vitro and in vivo. The activation of MAPK8/JNK1 (mitogen-activated protein kinase 8) and MAPK14/p38alpha MAPK signaling pathways was involved in the PGF mediated regulation of the TSC (tuberous sclerosis complex) pathway and autophagy in LE cells. Notably, PGF-induced MAPK8 and MAPK14 signaling pathways mediated the inactivation of MTOR (mechanistic target of rapamycin), the upregulation of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β) and the increase of autophagosome formation in mice. Furthermore, the PPE-induced autophagy promotes further apoptosis in vitro and in vivo. In summary, elastase-induced autophagy promotes LE cell apoptosis and pulmonary emphysema through the upregulation of PGF. PGF and its downstream MAPK8 and MAPK14 signaling pathways are potential therapeutic targets for the treatment of emphysema and COPD.

Elevated placenta growth factor predicts pneumonia in patients with chronic obstructive pulmonary disease under inhaled corticosteroids therapy

BackgroundAn increased incidence of pneumonia in patients with chronic obstructive pulmonary disease (COPD) under inhaled corticosteroid (ICS) therapy was noticed in previous studies. We performed a prospective study to elucidate the risk factors for the development of pneumonia in this group of patients.MethodsA prospective, non-randomized study with patients diagnosed as having COPD from 2007 to 2008 identified in the Far Eastern Memorial Hospital were recruited. We recorded data for all patients, including clinical features and signs, demographic data, lung function status, and medications. Bio-markers such as C-reactive protein (CRP) and placenta growth factor (PlGF) were checked at first diagnosis. Every acute exacerbation was also recorded, especially pneumonia events, which were confirmed by chest radiography. Multivariate analysis was performed with stepwise logistic regression for pneumonia risk factors.Results274 patients were diagnosed as having COPD during the study period and 29 patients suffered from pneumonia with a prevalence of 10.6%. The rate was significantly higher in patients with ICS therapy (20/125, 16%) compared with those without ICS (9/149, 6%) (p = 0.02). We stratified ICS therapy into medium dose (500-999 ug/day fluticasone equivalent, 71 patients) and high dose (1000 ug/day and higher fluticasone equivalent, 54 patients) group. There was no statistical difference in the incidence of pneumonia between these two group (medium dose: 13/71, 18.3% vs. high dose: 7/54, 12.9%, p = 0.47). Multivariate analysis was performed to identify the risk factors for developing pneumonia and included forced expiratory volume in one second (FEV1) less than 40% of predicted (odds ratio (OR) 2.2, 95% confidence interval (CI): 1.1-6.9), ICS prescription ((OR) 2.4, 95% (CI): 1.3-8.7), the presence of diabetes mellitus (DM) (OR 2.6, 95% CI: 1.2-9.4) and PlGF level over 40 pg/L (OR 4.1, 95% CI: 1.5-9.9).ConclusionICS therapy in patients with COPD increased the risk of pneumonia. However, there was no relationship between the incidence of pneumonia and dosage of ICS. Additionally, advanced COPD status, DM and elevated PlGF level were independent risk factors for the development of pneumonia. PlGF would be a good novel biomarker for predicting pneumonia.

PlGF mediates neutrophil elastase-induced airway epithelial cell apoptosis and emphysema

BackgroundChronic pulmonary obstructive disease (COPD) has become the fourth leading cause of death worldwide. Cigarette smoking induces neutrophil elastase (NE) and contributes to COPD, but the detailed mechanisms involved are not fully established. In an animal model of pulmonary emphysema, there are increased expressions of placenta growth factor (PlGF) and lung epithelial (LE) cell apoptosis. This study hypothesized that excessive NE may up-regulate PlGF and that PlGF-induced LE apoptosis mediates the pathogenesis of pulmonary emphysema.MethodsHuman bronchial epithelial cells, BEAS-2B, and primary mouse type II alveolar epithelial cells were treated with NE. The PlGF promoter activity was examined by luciferase activity assay, while PlGF expression and secretion were evaluated by RT-PCR, Western blotting, and ELISA. Both cell lines were treated with PlGF to evaluate its effects and the downstream signaling pathways leading to LE cell apoptosis. PlGF knockout and wild-type mice were instilled with NE to determine the roles of PlGF and its downstream molecules in NE-promoted mice pulmonary apoptosis and emphysema phenotype.ResultsThe transcriptional factor, early growth response gene-1, was involved in the NE-promoted PlGF promoter activity, and the expression and secretion of PlGF mRNA and protein in LE cells. PlGF-induced LE cell apoptosis and NE-induced mice pulmonary apoptosis and emphysema were mediated by the downstream c-Jun N-terminal kinase (JNK) and protein kinase C (PKC)δ signaling pathways.ConclusionThe NE-PlGF-JNK/PKCδ pathway contributes to the pathogenesis of LE cell apoptosis and emphysema. PlGF and its downstream signaling molecules may be potential therapeutic targets for COPD.