Thioredoxin-1 ameliorates cigarette smoke-induced lung inflammation and emphysema in mice

Cigarette smoking is associated with the development of inflammatory lung diseases representing major health problems world-wide. We hypothesized that the redox-regulating molecule thioredoxin-1 (TRX), which shows anti-inflammatory, antioxidative, and antiapoptotic effects, could be induced by cigarette smoke (CS) and contribute to protect against CS-induced inflammation and lung destruction. In an acute study, human TRX transgenic mice and C57BL6/J mice were exposed to mainstream CS for 3 days. In the lungs of CS-exposed mice, bronchial epithelial injury and bronchoalveolar lavage neutrophilia were observed. Oxidative stress and apoptosis were enhanced, and the expression of cytokines macrophage inflammatory protein-2 and tumor necrosis factor (TNF)-alpha was increased 15.3- and 2.4-fold, respectively. Compared with C57BL6/J mice, TRX-transgenic mice had significantly less inflammation, oxidative damage, and apoptosis, as well as decreased levels of matrix metalloprotease-12 mRNA and serum TNF-alpha. When recombinant human TRX (40 microg/body/day, 3 days) was injected i.p. into CS-exposed C57BL6/J mice, a significant effect to offer protection against CS-induced lung injury was observed through suppression of neutrophil influx. In the chronic study, TRX-transgenic mice and C57BL6/J mice were exposed to CS for 6 months. This chronic exposure caused pulmonary emphysema in C57BL6/J mice accompanying prominent infiltration of macrophages and neutrophils to lung. These pathological changes were significantly suppressed in TRX-transgenic mice. In conclusion, TRX induction ameliorated CS-induced lung inflammation and emphysema in mice. TRX-1 may therefore play a preventive or therapeutic role in lung inflammatory disorders such as chronic obstructive pulmonary disease.     

糜蛋白酶在烟草烟雾诱导的仓鼠肺动脉高压中的作用

目的探讨糜蛋白酶在烟草烟雾所诱导的肺动脉重构和肺动脉高压中的作用。方法将仓鼠暴露在烟草产生的烟雾中（烟雾暴露组,n=6）,4个月后,使用免疫组织化学法、蛋白免疫印迹法、放射免疫学测定、反转录PCR等测定仓鼠肺的形态学和肺组织的生物化学改变。对烟雾暴露组与对照组（n=6）上述指标进行比较。结果长期烟草烟雾暴露使仓鼠右心室收缩压升高,肺小动脉中层细胞肥大,同时肺组织糜蛋白酶活性及合成增加,血管紧张素Ⅱ（AngⅡ）水平升高（与对照组比较,P均﹤0.05）。糜蛋白酶抑素（chymostatin）可以降低烟草诱导的仓鼠肺组织中糜蛋白酶活性的增加和AngⅡ水平,改善肺小动脉的重构程度,降低右心室收缩压,但对仓鼠肺组织中血管紧张素转换酶（ACE）的活性无影响。结论长期烟草烟雾暴露可增加仓鼠肺中糜蛋白酶的活性及表达,激活的糜蛋白酶进一步诱导肺组织AngⅡ形成,这可能是烟草诱导的肺动脉高压发生机制的一部分。因此,糜蛋白酶抑素也许会对吸烟的肺动脉高压患者有益。     

Lung endothelial monocyte-activating protein 2 is a mediator of cigarette smoke-induced emphysema in mice

Pulmonary emphysema is a disease characterized by alveolar cellular loss and inflammation. Recently, excessive apoptosis of structural alveolar cells has emerged as a major mechanism in the development of emphysema. Here, we investigated the proapoptotic and monocyte chemoattractant cytokine endothelial monocyte-activating protein 2 (EMAPII). Lung-specific overexpression of EMAPII in mice caused simplification of alveolar structures, apoptosis, and macrophage accumulation, compared with that in control transgenic mice. Additionally, in a mouse model of cigarette smoke-induced (CS-induced) emphysema, EMAPII levels were significantly increased in murine lungs. This upregulation was necessary for emphysema development, as neutralizing antibodies to EMAPII resulted in reduced alveolar cell apoptosis, inflammation, and emphysema-associated structural changes in alveoli and small airways and improved lung function. The mechanism of EMAPII upregulation involved an apoptosis-dependent feed-forward loop, since caspase-3 instillation in the lung markedly increased EMAPII expression, while caspase inhibition decreased its production, even in transgenic EMAPII mice. These findings may have clinical significance, as both current smokers and ex-smoker chronic obstructive pulmonary disease (COPD) patients had increased levels of secreted EMAPII in the bronchoalveolar lavage fluid compared with that of nonsmokers. In conclusion, we suggest that EMAPII perpetuates the mechanism of CS-induced lung emphysema in mice and, given its secretory nature, is a suitable target for neutralization antibody therapy.     

Angiotensin receptor blockade attenuates cigarette smoke-induced lung injury and rescues lung architecture in mice

Chronic obstructive pulmonary disease (COPD) is a prevalent smoking-related disease for which no disease-altering therapies currently exist. As dysregulated TGF-β signaling associates with lung pathology in patients with COPD and in animal models of lung injury induced by chronic exposure to cigarette smoke (CS), we postulated that inhibiting TGF-β signaling would protect against CS-induced lung injury. We first confirmed that TGF-β signaling was induced in the lungs of mice chronically exposed to CS as well as in COPD patient samples. Importantly, key pathological features of smoking-associated lung disease in patients, e.g., alveolar injury with overt emphysema and airway epithelial hyperplasia with fibrosis, accompanied CS-induced alveolar cell apoptosis caused by enhanced TGF-β signaling in CS-exposed mice. Systemic administration of a TGF-β-specific neutralizing antibody normalized TGF-β signaling and alveolar cell death, conferring improved lung architecture and lung mechanics in CS-exposed mice. Use of losartan, an angiotensin receptor type 1 blocker used widely in the clinic and known to antagonize TGF-β signaling, also improved oxidative stress, inflammation, metalloprotease activation and elastin remodeling. These data support our hypothesis that inhibition of TGF-β signaling through angiotensin receptor blockade can attenuate CS-induced lung injury in an established murine model. More importantly, our findings provide a preclinical platform for the development of other TGF-β-targeted therapies for patients with COPD.     

Protective effects of liquiritin apioside on cigarette smoke-induced lung epithelial cell injury

Cigarette smoking is associated with an increased incidence of chronic obstructive pulmonary disease (COPD). In this study, we hypothesized that liquiritin apioside (LA), a main flavonoid component from Glycyrrhiza uralensis, had antioxidant properties by inducing glutathione (GSH) biosynthesis via the inhibition of cytokines and protected lung epithelial cells against cigarette smoke-mediated oxidative stress. A549 cells were treated with cigarette smoke extract (CSE) and/or LA. ICR mice were exposed to cigarette smoke (CS) for four days with increasing exposure time for up to 6 h per day to elicit epithelial cells injury. One hour before smoke exposure, mice were treated with LA by gavage; 18 h after the last CS exposure all examinations were performed. Treatment with LA concentration-dependently prevented CSE-induced cytotoxicity, increase of TGF-β and TNF-α mRNA expression, depletion of GSH and apoptosis in A549 cells. LA at doses 3, 10 and 30 mg/kg dose-dependently inhibited pulmonary neutrophil and macrophage inflammation. Lung sections of the CS-exposed LA treated mice showed an apparently reduced pulmonary inflammation and a significant inhibitory effect on mucus containing goblet cells in the large airways. Furthermore, the CS-induced pulmonary release of TGF-β, TNF-α and myeloperoxidase activity was reduced, and superoxide dismutase activity was enhanced.These results indicate that protective roles of LA on CS-induced the lung epithelial cell injury are mediated by inhibiting TGF-β and TNF-α expression and increasing anti-oxidative levels of GSH, suggesting that LA might be effective as protective agent against epithelial injury in COPD.     

CCR1 and CCR5 promote hepatic fibrosis in mice

Hepatic fibrosis develops as a response to chronic liver injury and almost exclusively occurs in a proinflammatory environment. However, the role of inflammatory mediators in fibrogenic responses of the liver is only poorly understood. We therefore investigated the role of CC chemokines and their receptors in hepatic fibrogenesis. The CC chemokines MIP-1α, MIP-1β, and RANTES and their receptors CCR1 and CCR5 were strongly upregulated in 2 experimental mouse models of fibrogenesis. Neutralization of CC chemokines by the broad-spectrum CC chemokine inhibitor 35k efficiently reduced hepatic fibrosis, and CCR1- and CCR5-deficient mice displayed substantially reduced hepatic fibrosis and macrophage infiltration. Analysis of fibrogenesis in CCR1- and CCR5-chimeric mice revealed that CCR1 mediates its profibrogenic effects in BM-derived cells, whereas CCR5 mediates its profibrogenic effects in resident liver cells. CCR5 promoted hepatic stellate cell (HSC) migration through a redox-sensitive, PI3K-dependent pathway. Both CCR5-deficient HSCs and CCR1- and CCR5-deficient Kupffer cells displayed strong suppression of CC chemokine–induced migration. Finally, we detected marked upregulation of RANTES, CCR1, and CCR5 in patients with hepatic cirrhosis, confirming activation of the CC chemokine system in human fibrogenesis. Our data therefore support a role for the CC chemokine system in hepatic fibrogenesis and suggest distinct roles for CCR1 and CCR5 in Kupffer cells and HSCs.     

Agonistic induction of PPARγ reverses cigarette smoke–induced emphysema

The development of emphysema in humans and mice exposed to cigarette smoke is promoted by activation of an adaptive immune response. Lung myeloid dendritic cells (mDCs) derived from cigarette smokers activate autoreactive Th1 and Th17 cells. mDC-dependent activation of T cell subsets requires expression of the SPP1 gene, which encodes osteopontin (OPN), a pleiotropic cytokine implicated in autoimmune responses. The upstream molecular events that promote SPP1 expression and activate mDCs in response to smoke remain unknown. Here, we show that peroxisome proliferator–activated receptor γ (PPARG/Pparg) expression was downregulated in mDCs of smokers with emphysema and mice exposed to chronic smoke. Conditional knockout of PPARγ in APCs using Cd11c-Cre Pparg^flox/flox mice led to spontaneous lung inflammation and emphysema that resembled the phenotype of smoke-exposed mice. The inflammatory phenotype of Cd11c-Cre Pparg^flox/flox mice required OPN, suggesting an antiinflammatory mechanism in which PPARγ negatively regulates Spp1 expression in the lung. A 2-month treatment with a PPARγ agonist reversed emphysema in WT mice despite continual smoke exposure. Furthermore, endogenous PPARγ agonists were reduced in the plasma of smokers with emphysema. These findings reveal a proinflammatory pathway, in which reduced PPARγ activity promotes emphysema, and suggest that targeting this pathway in smokers could prevent and reverse emphysema.     

Integrase inhibitors and CCR5 receptor antagonists

Integrase inhibitors and CCR5 receptor antagonists, novel class of antiretrovirals, were introduced into clinical practice in late 2000s. Currently available drugs in these classes, raltegravir and maraviroc, show good tolerability and have little impact on lipid or glucose metabolism compared to traditional classes. Disadvantage of these two drugs is the need for twice-daily dosing. The usefulness of raltegravir in both treatment-na?ve and treatment-experienced setting has been well established through clinical trials and five years' clinical use, whereas the usefulness of maraviroc in treatment-na?ve setting is still unclear. These drugs will be utilized as a key component of NRTI-sparing regimens in the future.     

Differential use of CCR5 by HIV-1 clinical isolates resistant to small-molecule CCR5 antagonists

How HIV-1 resistant to small-molecule CCR5 antagonists uses the coreceptor for entry has been studied in a limited number of isolates. We characterized dependence on the N terminus (NT) and the second extracellular loop (ECL2) of CCR5 of three vicriviroc (VCV)-resistant clinical isolates broadly cross-resistant to other CCR5 antagonists. Pseudoviruses were constructed to assess CCR5 use by VCV-sensitive and -resistant envelopes of subtype B and C viruses. We determined the extent of entry inhibition by monoclonal antibodies (MAbs) directed against the NT and ECL2 in the presence and absence of VCV and the capacity of these pseudoviruses to use CCR5 mutants that contained scanning alanine substitutions in the CCR5 NT and ECL2 domains. Sensitive and resistant viruses were completely and competitively inhibited by the ECL2-specific MAb 2D7, whereas the NT-specific MAb CTC5 led to partial noncompetitive inhibition. VCV-resistant clones showed greater sensitivity to 2D7 than VCV-sensitive clones, but in the presence of saturating VCV concentrations, the 2D7 susceptibilities of two VCV-resistant viruses were similar to that of VCV-sensitive virus. The entry of VCV-sensitive and -resistant isolates was impaired to differing degrees by alanine mutations in CCR5; substitutions in NT had the greatest effect on viral entry. HIV-1 clinical isolates broadly resistant to CCR5 antagonists demonstrated significant heterogeneity in their use of CCR5. This heterogeneity makes it difficult to draw general conclusions about the relationship between patterns of CCR5 antagonist resistance and the use of specific CCR5 domains for entry.     

Analysis of binding sites for the new small-molecule CCR5 antagonist TAK-220 on human CCR5

G protein-coupled receptor CCR5 is the main coreceptor for macrophage-tropic human immunodeficiency virus type 1 (HIV-1), and various small-molecule CCR5 antagonists are being developed to treat HIV-1 infection. It has been reported that such CCR5 antagonists, including TAK-779, bind to a putative binding pocket formed by transmembrane domains (TMs) 1, 2, 3 and 7 of CCR5, indicating the importance of the conformational changes of the TMs during virus entry. In this report, using a single-round infection assay with human CCR5 and its substitution mutants, we demonstrated that a new CCR5 antagonist, TAK-220, shares the putative interacting amino acid residues Asn252 and Leu255 in TM6 with TAK-779 but also requires the distinct residues Gly163 and Ile198 in TMs 4 and 5, respectively, for its inhibitory effect. We suggested that, together with molecular models of the interactions between the drugs and CCR5, the inhibitory activity of TAK-220 could involve direct interactions with amino acid residues in TMs 4, 5, and 6 in addition to those in the previously postulated binding pocket. The possible interaction of drugs with additional regions of the CCR5 molecule would help to develop a new small-molecule CCR5 antagonist.     

Comparison of cigarette smoke-induced acute inflammation in multiple strains of mice and the effect of a matrix metalloproteinase inhibitor on these responses

The activities of proteases in the lung, specifically matrix metalloproteinases (MMPs), have been implicated in driving the inflammation and lung destruction observed in smokers with chronic obstructive pulmonary disease. Here, our aims were to compare the acute response with cigarette smoke exposure (CSE) in four mouse strains to identify common and distinguishing features and to assess the effect of an MMP inhibitor on this response. To do this, we exposed mice (BALB/C, C57BL/6, A/J, or 129/Sv) to whole-body CSE (1 h/day) for 3 days. CSE induced dose- and time-dependent increases in neutrophils and keratinocyte chemoattractant levels in the airways of all strains; however, the proportion of the neutrophilia differed among strains. In the two most contrasting strains, BALB/C and C57BL/6, we examined MMP gene expression and found only small changes apart from MMP-12, which was highly expressed in both strains. Both strains were then treated with a broad-spectrum MMP inhibitor, PKF242-484 [(2S,3R)-N(4)-((S)-2,2-dimethyl-1-methylcarbamoyl-propyl)-N(1)-hydroxy-2-hydroxymethyl-3-(4-methoxy-phenyl)-succinimide] (0.5-10 mg/kg) either orally or intranasally 1 h before and 5 h after CSE for 3 days. PKF242-484 dose-dependently reduced neutrophilia in BALB/C mice when dosed orally (p < 0.01) or intranasally (p < 0.01) but had no clear effect in C57BL/6 by either route. PKF242-484 reduced BAL macrophages when dosed intranasally (p < 0.05) but had no dose-dependent effect when dosed orally in both strains. These data suggest the inflammation induced by CSE is similar, but not identical, in different mouse strains. In addition, the ability of broad-spectrum MMP inhibitors to inhibit smoke-induced acute neutrophil inflammation is strain-dependent, whereas its ability to limit macrophage infiltration may be route dependent.     

Development of tetravalent, bispecific CCR5 antibodies with antiviral activity against CCR5 monoclonal antibody-resistant HIV-1 strains

In this study, we describe novel tetravalent, bispecific antibody derivatives that bind two different epitopes on the HIV coreceptor CCR5. The basic protein formats that we applied were derived from Morrison-type bispecific antibodies: whole IgGs to which we connected single-chain antibodies (scFvs) via (Gly4Ser)n sequences at either the C or N terminus of the light chain or heavy chain. By design optimization, including disulfide stabilization of scFvs or introduction of 30-amino-acid linkers, stable molecules could be obtained in amounts that were within the same range as or no less than 4-fold lower than those observed with monoclonal antibodies in transient expression assays. In contrast to monospecific CCR5 antibodies, bispecific antibody derivatives block two alternative docking sites of CCR5-tropic HIV strains on the CCR5 coreceptor. Consequently, these molecules showed 18- to 57-fold increased antiviral activities compared to the parent antibodies. Most importantly, one prototypic tetravalent CCR5 antibody had antiviral activity against virus strains resistant to the single parental antibodies. In summary, physical linkage of two CCR5 antibodies targeting different epitopes on the HIV coreceptor CCR5 resulted in tetravalent, bispecific antibodies with enhanced antiviral potency against wild-type and CCR5 antibody-resistant HIV-1 strains.     

CCR2/CCR5 inhibitor permits the radiation-induced effector T cell infiltration in pancreatic adenocarcinoma

The resistance of pancreatic ductal adenocarcinoma (PDAC) to immune checkpoint inhibitors (ICIs) is attributed to the immune-quiescent and -suppressive tumor microenvironment (TME). We recently found that CCR2 and CCR5 were induced in PDAC following treatment with anti–PD-1 antibody (αPD-1); thus, we examined PDAC vaccine or radiation therapy (RT) as T cell priming mechanisms together with BMS-687681, a dual antagonist of CCR2 and CCR5 (CCR2/5i), in combination with αPD-1 as new treatment strategies. Using PDAC mouse models, we demonstrated that RT followed by αPD-1 and prolonged treatment with CCR2/5i conferred better antitumor efficacy than other combination treatments tested. The combination of RT + αPD-1 + CCR2/5i enhanced intratumoral effector and memory T cell infiltration but suppressed regulatory T cell, M2-like tumor–associated macrophage, and myeloid-derived suppressive cell infiltration. RNA sequencing showed that CCR2/5i partially inhibited RT-induced TLR2/4 and RAGE signaling, leading to decreased expression of immunosuppressive cytokines including CCL2/CCL5, but increased expression of effector T cell chemokines such as CCL17/CCL22. This study thus supports the clinical development of CCR2/5i in combination with RT and ICIs for PDAC treatment.     

趋化因子受体CCR1、CCR5在多发性骨髓瘤中的表达及对瘤细胞与基质细胞黏附的影响

目的:观察趋化因子受体CCR1、CCR5在多发性骨髓瘤患者骨髓单个核细胞、骨髓基质细胞、人多发性骨髓瘤细胞系KM3、SKO007、XG-6中的表达及介导巨噬细胞炎症蛋白-1α对瘤细胞与基质细胞的黏附。方法:选择2004-08/2006-07在桂林医学院附属医院血液科住院的患者16例,男10例,女6例,中位年龄56岁,经国内统一标准确诊为多发性骨髓瘤患者。患者知情同意,并经医院伦理委员会批准。①实验方法:取样本进行骨髓单个核细胞与骨髓基质细胞的分离培养。人多发性骨髓瘤细胞系KM3、SKO007、XG-6从外室传代引进后,在含体积分数为0.10胎牛血清的RPMI1640培养液中培养,每3天更换1次培养液,本实验用的细胞均处于对数生长期。②实验评估:半定量RT-PCR及Western-blot技术检测骨髓瘤骨髓单个核细胞、骨髓基质细胞及骨髓瘤细胞系KM3、SKO007、XG-6中的CCR1、CCR5表达;MTT微量酶反应比色法定量检测瘤细胞与基质细胞的黏附。结果:①约43.8%的多发性骨髓瘤患者骨髓及2/3的多发性骨髓瘤细胞系均表达CCR1、CCR5两种受体,约6.25%的多发性骨髓瘤患者骨髓单个核细胞仅表达CCR1受体,且大部分能在蛋白质水平上进一步得到鉴定。②加巨噬细胞炎症蛋白1α单抗、CCR1和/或CCR5单抗组,KM3、SKO007、XG-6细胞与基质细胞的黏附作用较对照组明显下降(P<0.05),而单抗组间无明显差异(P>0.05)。结论:大部分多发性骨髓瘤患者及多发性骨髓瘤细胞系表达CCR1、CCR5两种受体,巨噬细胞炎症蛋白1α可能是运用CCR1、CCR5两种受体来介导瘤细胞与基质细胞的黏附。     

Role of alpha-macroglobulin-elastase complexes in the pathogenesis of elastase-induced emphysema in hamsters.

Radiolabeled, enzymatically active or chloromethyl ketone-inactivated porcine pancreatic elastase was endotracheally instilled into hamsters. Gel filtration of the bronchopulmonary lavage fluid revealed two major radioactive fractions: one, eluting at 780,000 daltons, corresponding to an alpha-macroglobulin-pancreatic elastase complex, and another, at 68,000 daltons, corresponding to an alpha-1-protease inhibitor-pancreatic elastase complex. Elastolytic activity was recovered in the bronchopulmonary lavage fluid up to 4 d after elastase instillation and was associated with the alpha-macroglobulin-pancreatic elastase complex. Small amounts of this complex were recovered 14 d after instillation. When less than 1% (1.5--1.7 micrograms) of the usual dose of elastase was instilled into hamsters, the major radioactive complex was alpha-1-protease inhibitor-pancreatic elastase complex, and little or no elastolytic activity was found in the lavage fluid. In contrast to the instillation of 220 micrograms of elastase, no disease or hemorrhagic reaction was detected with this low dose, and without hemorrhage only insignificant amounts of alpha-macroglobulin-pancreatic elastase complexes were recovered from the lungs. To study the interaction of circulating antiproteases with elastase, hamster plasma was allowed to interact directly with the radiolabeled elastase; alpha-macroglobulin bound much more of the elastase than alpha-1-protease inhibitor, confirming the findings in the lung lavage experiments. The hamster's susceptibility to pancreatic elastase-induced emphysema may depend on the preferential binding of elastase to alpha-macroglobulin, which protects the elastolytic potential, rather than to alpha-1-protease inhibitor, which inactivates elastase. We speculate that if even a fraction of the residual radioactivity found in the hamster lungs as long as 144 d after instillation of elastase represents enzymatically active alpha-macroglobulin-pancreatic elastase complex, this could serve as a source of persistent elastolytic activity, which might explain the progressive nature of the pulmonary lesion.     

Polymorphisms in the CC-chemokine receptor-2 (CCR2) and -5 (CCR5) genes and risk of myocardial infarction among Tunisian male patients

ObjectivesThe aim of the present study was to investigate the association between CCR2-Val64Ile and CCR5-Δ32 variants and the estimation of haplotypes with MI in a sample of the Tunisian population.Design and methodsA total of 290 unrelated MI patients and 282 healthy controls were studied. The CCR2-Val64Ile and CCR5-Δ32 variants were analyzed by PCR-RFLP.ResultsSubjects carrying at least one copy of the CCR5-deletion allele were significantly more common in the control group, suggesting an atheroprotective effect (adjusted OR = 0.44, 95% CI = 0.28–0.72, p = 0.001). Haplotype analysis showed that MI patients had significantly less 64Val-Del haplotype (9.9% vs. 21.3%, OR = 0.30, 95% CI = 0.21–0.43, p < 0.001) and 64Ile-Ins haplotype (12.3% vs. 16.7%, OR = 0.58, 95% CI = 0.42–0.80, p < 0.001).ConclusionA protective effect of the CCR5-Δ32 polymorphism against MI in the Tunisian population was found.     

Interleukin 10 Increases CCR5 Expression and HIV Infection in Human Monocytes

The immunosuppressive and antiinflammatory cytokine interleukin (IL) 10 selectively upregulates the expression of the CC chemokine receptors CCR5, 2, and 1 in human monocytes by prolonging their mRNA half-life. IL-10–stimulated monocytes display an increased number of cell surface receptors for, and better chemotactic responsiveness to, relevant agonists than do control cells. In addition, IL-10–stimulated monocytes are more efficiently infected by HIV BaL. This effect was associated to the enhancement of viral entry through CCR5. These data add support to an emerging paradigm in which pro- and antiinflammatory molecules exert reciprocal and opposing influence on chemokine agonist production and receptor expression.