Christopher Lambers

Anti-fibrotic effects of nintedanib in lung fibroblasts derived from patients with idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive lung disease with poor prognosis. The kinase inhibitor nintedanib specific for vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR) and fibroblast growth factor receptor (FGFR) significantly reduced the rate of decline of forced vital capacity versus placebo.AimTo determine the in vitro effect of nintedanib on primary human lung fibroblasts. Methods: Fibroblasts were isolated from lungs of IPF patients and from non-fibrotic controls. We assessed the effect of VEGF, PDGF-BB and basic FGF (bFGF) ± nintedanib on: (i) expression/activation of VEGFR, PDGFR, and FGFR, (ii) cell proliferation, secretion of (iii) matrix metalloproteinases (MMP), (iv) tissue inhibitor of metalloproteinase (TIMP), and (v) collagen.ResultsIPF fibroblasts expressed higher levels of PDGFR and FGFR than controls. PDGF-BB, bFGF, and VEGF caused a pro-proliferative effect which was prevented by nintedanib. Nintedanib enhanced the expression of pro-MMP-2, and inhibited the expression of TIMP-2. Transforming growth factor-beta-induced secretion of collagens was inhibited by nintedanib.ConclusionOur data demonstrate a significant anti-fibrotic effect of nintedanib in IPF fibroblasts. This effect consists of the drug’s anti-proliferative capacity, and on its effect on the extracellular matrix, the degradation of which seems to be enhanced.

T cell senescence and contraction of T cell repertoire diversity in patients with chronic obstructive pulmonary disease

Pathogenetic mechanisms leading to chronic obstructive pulmonary disease (COPD) remain poorly understood. Because clonogenic T cells (CD4+CD28null) were shown to be increased in autoimmune diseases we hypothesized that CD4+CD28null T cells play a role in COPD. Here we describe that enhanced presence of CD4+CD28null cells is associated with impaired lung function. Sixty‐four patients and controls were included. T cell phenotype was analysed using flow cytometry. Enzyme‐linked immunosorbent assays were utilized to determine cytokines. Statistical evaluations were performed using non‐parametric group comparisons and correlations. A logistic regression model was used to determine predictive values of CD4+CD28null in the diagnosis of COPD. Populations of CD4+ T cells lacking surface co‐stimulatory CD28 were enlarged significantly in evaluated patients when compared with controls. Natural killer (NK)‐like T cell receptors (CD94, 158) and intracellular perforin, granzyme B were increased in CD4+CD28null cells. Cytokine production after triggering of peripheral blood mononuclear cells (PBMCs) was elevated in patients at early disease stages. Receiver operating characteristic curve plotting revealed that presence of CD4+CD28null T cells has a diagnostic value. These CD4+CD28null T cells show increased expression of NK‐like T cell receptors (CD94, 158) and intracellular perforin and granzyme B. Furthermore, triggering of PBMCs obtained from patients with mild COPD led to increased interferon‐γ and tumour necrosis factor‐α production in vitro compared with controls. Our finding of increased CD4+CD28null T cells in COPD indicates that chronic antigen exposure, e.g. through contents of smoke, leads to loss of CD28 and up‐regulation of NK cell receptors expression on T cells in susceptible patients.

Discrimination of clinical stages in non-small cell lung cancer patients by serum HSP27 and HSP70: a multi-institutional case-control study.

INTRODUCTION Lung cancer represents a major healthcare problem. Accordingly, there is an urgent need to identify serum biomarkers for early diagnosis of lung pathology. We have recently described that patients with manifest COPD evidence elevated levels of heat shock proteins (HSPs). Based on these data, we speculated whether HSPs are also increased in patients with diagnosed lung cancer. METHODS Serum levels of HSP27, phospho-HSP27 (pHSP27) and HSP70 in patients with non-small cell lung cancer (NSCLC) diagnosed at an early (stages I-II, n=37) or advanced (stages IIIA-IV, n=72) stage were determined by using ELISA. Healthy smokers (n=24), healthy never-smoker volunteers (n=33) and COPD patients (n=34) according to GOLD classification served as control population. RESULTS Serum levels of HSP27 were elevated in patients with NSCLC diagnosed at an early or advanced stage when compared with both healthy control groups (P<0.005 and P<0.0001 respectively). Statistically significant differences were furthermore found between the groups of patients with early vs. advanced stage NSCLC (P=0.0021). Serum levels of HSP70 were also significantly elevated in patients with NSCLC diagnosed at an early or at an advanced stage when compared with either healthy control groups (P=0.0028 and P<0.0001 respectively). In univariate logistic regression models including healthy subjects and patients with NSCLC, HSP70 had an area under the curve (AUC) of 0.779 (P<0.0001) and HSP27 showed an AUC of 0.870 (P<0.0001). CONCLUSION Our data suggest that serum HSP27 levels might serve as a possible tool to discriminate between early and advanced stages NSCLC.

Increased soluble serum markers caspase-cleaved cytokeratin-18, histones, and ST2 indicate apoptotic turnover and chronic immune response in COPD.

Introduction: Chronic obstructive pulmonary disease (COPD) is a worldwide burden and a major cause of death. The disease is accompanied by chronic inflammation and increased cellular turnover that is partly due to an overwhelming induction of apoptosis. In this study, we hypothesized that systemic markers of apoptosis are altered in patients with mild‐to‐severe COPD.

The Interaction of Endothelin-1 and TGF-β1 Mediates Vascular Cell Remodeling

Background Pulmonary arterial hypertension is characterized by increased thickness of pulmonary vessel walls due to both increased proliferation of pulmonary arterial smooth muscle cell (PASMC) and deposition of extracellular matrix. In patients suffering from pulmonary arterial hypertension, endothelin-1 (ET-1) synthesis is up-regulated and may increase PASMC activity and vessel wall remodeling through transforming growth factor beta-1 (TGF-β1) and connective tissue growth factor. Objective To assess the signaling pathway leading to ET-1 induced proliferation and extracellular matrix deposition by human PASMC. Methods PASMC were serum starved for 24 hours before stimulation with either ET-1 and/or TGF-β1. ET-1 was inhibited by Bosentan, ERK1/2 mitogen activated protein kinase (MAPK) was inhibited by U0126 and p38 MAPK was inhibited by SB203580. Results ET-1 increased PASMC proliferation when combined with serum. This effect involved the mitogen activated protein kinases (MAPK) ERK1/2 MAPK and was abrogated by Bosentan which caused a G1- arrest through activation of p27(Kip). Regarding the contribution of extracellular matrix deposition in vessel wall remodeling, TGF-β1 increased the deposition of collagen type-I and fibronectin, which was further increased when ET-1 was added mainly through ERK1/2 MAPK. In contrast, collagen type-IV was not affected by ET-1. Bosentan dose-dependently reduced the stimulatory effect of ET-1 on collagen type-I and fibronectin, but had no effect on TGF-β1. Conclusion and Clinical Relevance ET-1 alone does not induce PASMC proliferation and extracellular matrix deposition. However, ET-1 significantly up-regulates serum induced proliferation and TGF-β1 induced extracellular matrix deposition, specifically of collagen type-I and fibronectin. The synergistic effects of ET-1 on serum and TGF-β1 involve ERK1/2 MAPK and may thus present a novel mode of action in the pathogenesis of pulmonary arterial hypertension.

Increased serum levels of HSP27 as a marker for incipient chronic obstructive pulmonary disease in young smokers

Background: Although chronic obstructive pulmonary disease (COPD) is amongst the leading causes of morbidity and mortality, no biomarkers for its early detection are known. We have recently demonstrated that COPD is accompanied by elevated serum heat shock protein (HSP) 27 levels as compared to a control population. Objectives: In an open prospective study, we investigated whether elevated HSP27 levels are associated with the early radiological signs of COPD, i.e. air trapping (AT), emphysema (E) and impaired lung function. Methods: In total, 120 apparently healthy smokers underwent lung function testing and serum sampling. Serum levels of HSP27, phospho-HSP27, CXCR2 chemokines and proteins related to inflammation, tissue remodeling and apoptosis were evaluated by ELISA. Of these 120 subjects, 94 voluntarily underwent a high-resolution computed tomography scan. Results: AT or AT and E were detected in 57.45%. Subjects with AT and E (n = 23) showed significantly higher HSP27 levels than those without any pathology [i.e. nothing abnormal detected (NAD)] (4,618 ± 1,677 vs. 3,282 ± 1,607 pg/ml; p = 0.0081). In a univariate logistic regression model including NAD and AT and E, the area under the curve of HSP27 in the receiver-operating-characteristic curve was 0.724, (0.594–0.854, 95% CI; p = 0.0033). Interestingly, proinflammatory IL-8 was elevated in those subjects with evidence of AT and E compared to those with AT and NAD. Lung function did not correlate with increased HSP27 levels or pathological radiological findings. Conclusions: HSP27 serum levels correlated with the early radiological signs of COPD, whereas lung function did not match with radiological findings or HSP27 serum levels. Serum HSP27 levels may serve as a potential marker to identify the early signs of COPD independent of lung function in young smokers.

Vasoactive intestinal peptide (VIP) receptor expression in monocyte-derived macrophages from COPD patients.

Vasoactive intestinal peptide (VIP) is one of the most abundant molecules found in the respiratory tract. Due to its anti-inflammatory and bronchodilatatory properties, it has been proposed as a novel treatment for chronic obstructive pulmonary disease (COPD). The actions of VIP are mediated via three different G-protein-coupled receptors (VPAC1, VPAC2 and PAC1) which are expressed in the respiratory tract and on immunocompetent cells including macrophages. Alveolar macrophages (AM) are key players in the pathogenesis of COPD and contribute to the severity and progression of the disease. While VPAC1 has been reported to be elevated in subepithelial cells in smokers with chronic bronchitis, little is known about VPAC expression of AM in COPD patients. AM from COPD patients show a strong VPAC1 expression which exceeds VPAC2. A similar receptor expression pattern was also observed in lipopolysaccharide (LPS)-activated monocyte-derived macrophages (MDM) from healthy volunteers and COPD patients. VIP has been shown to down-regulate interleukin 8 (IL-8) secretion significantly in MDM after LPS stimulation. The response to VIP was similar in MDM from COPD patients and healthy volunteers. Our results indicate that VPAC1 up-regulation in macrophages is a common mechanism in response to acute and chronic pro-inflammatory stimuli. Although VPAC1 up-regulation is dominant, both receptor subtypes are necessary for optimal anti-inflammatory signaling. The high VPAC1 expression in AM may reflect the chronic pro-inflammatory environment found in the lung of COPD patients. Treatment with VIP may help to decrease the chronic inflammation in the lung of COPD patients.

The calcium channel blocker amlodipine exerts its anti-proliferative action via p21(Waf1/Cip1) gene activation

Proliferation of vascular smooth muscle cells (VSMC) contributes to the progression of athero¬sclerotic plaques. Calcium channel blockers have been shown to reduce VSMC proliferation, but the underlying molecular mechanism remains unclear. p21(Waf1/Cip1) is a potent inhibitor of cell cycle progression. Here, we demonstrate that amlodipine (10−6 to 10−8 M) activates de novo synthesis of p21(Waf1/Cip1) in vitro. We show that amlodipine‐dependent activation of p21(Waf1/Cip1) involves the action of the glucocorticoid receptor (GR) and C/EBP‐α. The underlying pathway apparently in¬volves the action of mitogen‐activated protein kinase or protein kinase C, but not of extracellular signal‐related kinase or changes of intracellular calcium. Amlodipine‐induced p21(Waf1/Cip1) promoter activity and expres¬sion were abrogated by C/EBP‐α antisense oligonucle¬otide or by the GR antagonist RU486. Amlodipinedependent inhibition of cell proliferation was partially reversed by RU486 at 10−8 M (58% ±29%), antisense oligonucleotides targeting C/EBP‐α (91%±26%), or antisense mRNAs targeting p21(Waf1/Cip1) (96%±32%, n=6);scrambled antisense oligonucleotides or those directed against C/EBP‐β were ineffective. The data suggest that the anti‐proliferative action of amlodipine is achieved by induction of the p21 (Waf1/Cip1) gene, which may explain beneficial covert effects of this widely used cardiovascular therapeutic drug beyond a more limited role as a vascular relaxant.—Ziesche, R., Petkov, V., Lambers, C., Erne, P., Block, L.‐H. The calcium channel blocker amlodipine exerts its antiproliferative action via p21(Waf1/Cip1) gene activation. FASEBJ. 18, 1516–1523 (2004)

Extracellular matrix composition is modified by β2-agonists through cAMP in COPD

Long acting β₂-agonists (LABA) have been reported to modify the extracellular matrix (ECM) composition in the airway wall. Based on our earlier studies we here investigated the mechanism underlying the control of ECM modification by LABA in primary human airway smooth muscle cells. Cells were treated with formoterol or salmeterol (30 min) before TGF-β₁ stimulation (2-3 days) Using RT-PCT, immuno-blotting and ELISA the de novo synthesis and deposition of collagen type-I, -III, -IV and fibronectin were determined. Matrix metalloproteinases (MMP)-2 and -9 were analyzed by zymography. Both LABA activated cAMP and its corresponding transcription factor CREB within 60 min and thus partly reduced TGF-β₁-induced gene transcription of collagen type-I, -III, fibronectin and connective tissue growth factor (CTGF). The inhibitory effect of both LABA on collagen type-I and -III deposition involved a cAMP dependent mechanism, while the inhibitory effect of the two drugs on TGF-β1-induced fibronectin deposition and on CTGF secretion was independent of cAMP. Interestingly, none of the two LABA reduced CTGF-induced synthesis of collagen type-I or type-III deposition. In addition, none of the two LABA modified collagen type-IV deposition or the expression and activity of MMP-2 or MMP-9. Our results show that LABA can prevent de novo deposition of specific ECM components through cAMP dependent and independent signaling. However, they do not reduce all ECM components by the same mechanism and they do not reduce existing collagen deposits. This might explain some of the controversial reports on the anti-remodeling effect of LABA in chronic inflammatory lung diseases.

Early immunomodulatory effects of linezolid in a human whole blood endotoxin model.

Gram-negative sepsis resulting in endotoxin triggered septic shock is one of the leading causes of death in critically ill patients. Because treatment options are limited, recent approaches focus on immunomodulatory effects of antimicrobials. Thus, we characterized the immunomodulatory effects of linezolid at mRNA and on cytokine levels in supernatants of an ex vivo model of endotoxemia. Whole blood from 10 healthy volunteers was incubated with 50 pg/ml LPS with or without 13 microg/ml linezolid (concentrations were chosen to reflect in vivo conditions) for 2 and 4 hours (h). Quantitative real-time PCR was performed from messenger RNA (mRNA) of IL-1beta;, IL-6, IL-8 or TNF-alpha;. Cytokine levels in the supernatant were measured by ELISA for IL-6, IL-8 and TNF-alpha;. Incubation of human whole blood with LPS increased mRNA levels of cytokines several thousand fold compared with baseline. The addition of linezolid significantly reduced mRNA levels of IL-1beta, IL-6, IL-8 and TNF-alpha; (p < 0.05) after 2 and 4 h. LPS stimulation also increased levels of IL-6, IL-8 and TNF-alpha between 100 and 1000-fold. However, in contrast to mRNA - except for IL-6 - no significant reduction at protein level was observed. These results indicate that immunosuppressive effects of linezolid on mRNA transcription are only partially reflected by cytokine release.