Jianping Zhao

Epithelial Interleukin-25 Is a Key Mediator in Th2-High, Corticosteroid-Responsive Asthma

RATIONALE Activation of type 2 cytokine pathways plays a central role in a large subset of subjects with asthma. Th2-high and Th2-low asthma have distinct clinical, pathologic, and molecular phenotypes and respond differently to therapy. The factors that initiate type 2 responses in some subjects with asthma are unknown. OBJECTIVES To determine whether expression of epithelial cytokines IL-25, IL-33, and thymic stromal lymphopoietin are associated with type 2 responses and predict response to inhaled corticosteroid (ICS) in asthma. METHODS We analyzed pulmonary function tests, blood, and bronchoscopic biopsies from 21 healthy control subjects and 43 subjects with asthma. Subjects with asthma underwent an 8-week treatment with inhaled budesonide. MEASUREMENTS AND MAIN RESULTS Epithelial expression of IL-25, but not IL-33 or thymic stromal lymphopoietin, was increased in a subset of subjects with asthma. The IL-25-high subset had greater airway hyperresponsiveness, more airway and blood eosinophils, higher serum IgE, more subepithelial thickening, and higher expression of Th2 signature genes. ICS improved FEV1 and hyperresponsiveness in the IL-25-high but not the IL-25-low subset. Plasma IL-25 levels correlated with epithelial IL-25 expression, airway eosinophilia, and beneficial responses to ICS treatment. CONCLUSIONS IL-25 measurements identify two subsets of subjects with distinct asthma phenotypes and different responses to ICS. Because IL-25 has a major role in triggering type 2 responses, bronchial epithelial IL-25 expression is likely a key determinant of type 2 response activation in asthma. Plasma IL-25 level reflects airway IL-25/type 2 response activation and may be useful for predicting responses to asthma therapy.

Increased IL-33 expression in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by inflammatory cell activation and the release of inflammatory mediators. Interleukin-33 (IL-33) plays a critical role in various inflammatory and immunological pathologies, but evidence for its role in COPD is lacking. This study aimed to investigate the expression of IL-33 in COPD and to determine whether IL-33 participates in the initiation and progression of COPD. Levels of serum IL-33 and its receptors were measured by ELISA, and serum levels of IL-33, ST2, and IL-1 receptor accessory protein were elevated in patients with COPD compared with control subjects. Flow cytometry analysis further demonstrated an increase in peripheral blood lymphocytes (PBLs) expressing IL-33 in patients with COPD. Immunofluorescence analysis revealed that the main cellular source of IL-33 in lung tissue was human bronchial epithelial cells (HBEs). Cigarette smoke extract and lipopolysaccharide could enhance the ability of PBLs and HBEs to express IL-33. Furthermore, PBLs from patients with COPD showed greater IL-33 release in response to the stimulus. Collectively, these findings suggest that IL-33 expression levels are increased in COPD and related to airway and systemic inflammation. Therefore, IL-33 might contribute to the pathogenesis and progression of this disease.

Involvement of Bcl-2 Family in Apoptosis and Signal Pathways Induced by Cigarette Smoke Extract in the Human Airway Smooth Muscle Cells

Chronic obstructive pulmonary disease (COPD) is a highly prevalent airway disease characterized by an abnormal inflammatory response of the lungs to noxious particles and gases. Cigarette smoking remains a major risk factor for COPD development; however, little is known about its effect on human airway smooth muscle cells (HASMCs). The aim of this study is to examine whether apoptosis is involved in cigarette smoke extract (CSE)-induced HASMC death and the molecular mechanisms underlying it. Our studies have shown that CSE increased the level of reactive oxygen species (ROS) and cell apoptosis of HASMCs in a dose- and time-dependent manner, and the ROS scavenger N-acetyl-cysteine abrogated the effect of ROS level and apoptosis on HASMCs. Further, the expression of Bax, Bad, and Fas was increased but Bcl-2 and nuclear factor-kappaB (NF-kappaB) was decreased in a dose- and time-dependent fashion in CSE-induced apoptosis in HASMCs. Taken together, CSE could inhibit the cell growth and induce apoptosis of HASMCs through both the mitochondrial pathway and death receptor pathway. Oxidative stress and inhibition of NF-kappaB expression caused by CSE may play important roles in apoptosis and inhibition of cell growth in HASMCs.

Regulation of transplanted mesenchymal stem cells by the lung progenitor niche in rats with chronic obstructive pulmonary disease

BackgroundStem cell transplantation is a promising method for the treatment of chronic obstructive pulmonary disease (COPD), and mesenchymal stem cells (MSCs) have clinical potential for lung repair/regeneration. However, the rates of engraftment and differentiation are generally low following MSC therapy for lung injury. In previous studies, we constructed a pulmonary surfactant-associated protein A (SPA) suicide gene system, rAAV-SPA-TK, which induced apoptosis in alveolar epithelial type II (AT II) cells and vacated the AT II cell niche. We hypothesized that this system would increase the rates of MSC engraftment and repair in COPD rats.MethodsThe MSC engraftment rate and morphometric changes in lung tissue in vivo were investigated by in situ hybridization, hematoxylin and eosin staining, Masson’s trichrome staining, immunohistochemistry, and real-time PCR. The expression of hypoxia inducible factor (HIF-1α) and stromal cell-derived factor-1 (SDF-1), and relationship between HIF-1α and SDF-1 in a hypoxic cell model were analyzed by real-time PCR, western blotting, and enzyme-linked immunosorbent assay.ResultsrAAV-SPA-TK transfection increased the recruitment of MSCs but induced pulmonary fibrosis in COPD rats. HIF-1α and SDF-1 expression were enhanced after rAAV-SPA-TK transfection. Hypoxia increased the expression of HIF-1α and SDF-1 in the hypoxic cell model, and SDF-1 expression was augmented by HIF-1α under hypoxic conditions.ConclusionsVacant AT II cell niches increase the homing and recruitment of MSCs to the lung in COPD rats. MSCs play an important role in lung repair and promote collagen fiber deposition after induction of secondary damage in AT II cells by rAAV-SPA-TK, which involves HIF-1α and SDF-1 signaling.

Interleukin-33/ST2 signaling promotes production of interleukin-6 and interleukin-8 in systemic inflammation in cigarette smoke-induced chronic obstructive pulmonary disease mice.

Interleukin-33 is a newly described member of the interleukin-1 family. Recent research suggests that IL-33 is increased in lungs and plays a critical role in chronic airway inflammation in cigarette smoke-induced chronic obstructive pulmonary disease (COPD) mice. To determine the role of IL-33 in systemic inflammation, we induced COPD mice models by passive cigarette smoking and identified the IL-33 expression in bronchial endothelial cells and peripheral blood mononuclear cells (PBMCs) of them. After isolation, PBMCs were cultured and stimulated in vitro. We measured expressions of interleukin-6 and interleukin-8 in PBMCs in different groups. The expression of IL-33 in bronchial endothelial cells and PBMCs of COPD mice were highly expressed. Stimulated by cigarette smoke extract (CSE), the expression of IL-6 and IL-8 were induced and enhanced by IL-33. PBMCs of COPD mice produced more IL-6 and IL-8 stimulated by CSE and IL-33. Expression of IL-6 and IL-8 were decreased when stimulated by IL-33 together with soluble ST2. The mRNA production of ST2 in IL-33 stimulated PBMCs was increased. Being pretreated with several kinds of MAPK inhibitors, the secretions of IL-6 and IL-8 in PBMCs did not decrease except for the p38 MAPK inhibitor. We found that IL-33 could induce and enhance the expression of IL-6 and IL-8 in PBMCs of COPD mice via p38 MAPK pathway, and it is a promoter of the IL-6 and IL-8 production in systemic inflammation in COPD mice.

Chop Deficiency Protects Mice Against Bleomycin-induced Pulmonary Fibrosis by Attenuating M2 Macrophage Production

C/EBP homologous protein (Chop) has been shown to have altered expression in patients with idiopathic pulmonary fibrosis (IPF), but its exact role in IPF pathoaetiology has not been fully addressed. Studies conducted in patients with IPF and Chop(-/-) mice have dissected the role of Chop and endoplasmic reticulum (ER) stress in pulmonary fibrosis pathogenesis. The effect of Chop deficiency on macrophage polarization and related signalling pathways were investigated to identify the underlying mechanisms. Patients with IPF and mice with bleomycin (BLM)-induced pulmonary fibrosis were affected by the altered Chop expression and ER stress. In particular, Chop deficiency protected mice against BLM-induced lung injury and fibrosis. Loss of Chop significantly attenuated transforming growth factor β (TGF-β) production and reduced M2 macrophage infiltration in the lung following BLM induction. Mechanistic studies showed that Chop deficiency repressed the M2 program in macrophages, which then attenuated TGF-β secretion. Specifically, loss of Chop promoted the expression of suppressors of cytokine signaling 1 and suppressors of cytokine signaling 3, and through which Chop deficiency repressed signal transducer and activator of transcription 6/peroxisome proliferator-activated receptor gamma signaling, the essential pathway for the M2 program in macrophages. Together, our data support the idea that Chop and ER stress are implicated in IPF pathoaetiology, involving at least the induction and differentiation of M2 macrophages.

Current evidence on the relationship between five polymorphisms in the matrix metalloproteinases (MMP) gene and lung cancer risk: a meta-analysis.

PURPOSE Matrix metalloproteinase (MMP) 1, MMP2, MMP3 and MMP9 are important members of the MMP family. Recently, many studies have been carried out on the association between polymorphisms of MMP1-1607 1G/2G, MMP2-735 C/T, MMP2-1306 C/T, MMP3-1171 5A/6A and MMP9-1562 C/T and lung cancer risk. However the results of these studies remained inconclusive due to conflicting results from different case-control studies. To clarify these associations, we conducted a meta-analysis. METHODS We conducted a comprehensive search in Medline, EMBASE, OVID and Chinese Biomedical Literature Database (date from Jan 2000 to Aug 2012). Overall and subgroup analysis by the ethnicity of study population was carried out. Odds ratio (OR) with 95% confidence interval (95%CI) was used to assess the strength of the association. RESULTS There were 17 studies involving five polymorphic sites in four MMP genes. For MMP1-1607,increased lung cancer risk was found under dominant model (MMP1-1607 1G/2G: OR=1.14, 95%CI=1.03-1.26, P=0.01), but not in the Caucasian population. For MMP2-1306 C/T, T polymorphism decreased lung cancer risk under dominant and recessive models (dominant, OR=0.63, 95%CI=0.46-0.88, P=0.0006; recessive, OR=0.61, 95%CI=0.38-0.99, P=0.04). For MMP9-1562 C/T, TT genotype decreased this risk under the recessive model (OR=0.38, 95%CI=0.19-0.75, P=0.005), but not in the Asian population. For MMP2-735 C/T and MMP3-1171 5A/6A, there was no association between this polymorphism and lung cancer risk under the dominant and recessive models. CONCLUSIONS MMP1-1607 1G/2G polymorphism increased lung cancer risk in Asians. It was also found that MMP2-1306 C/T polymorphism decreased lung cancer risk in Asians, while MMP9-1562 C/T polymorphism decreased lung cancer risk in Caucasians. No significant difference was found in any genotype of MMP2-735 C/T and MMP3-1171 5A/6A. Further studies with larger sample sizes should be carried out.

Intelectin contributes to allergen-induced IL-25, IL-33, and TSLP expression and type 2 response in asthma and atopic dermatitis

The epithelial and epidermal innate cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) have pivotal roles in the initiation of allergic inflammation in asthma and atopic dermatitis (AD). However, the mechanism by which the expression of these innate cytokines is regulated remains unclear. Intelectin (ITLN) is expressed in airway epithelial cells and promotes allergic airway inflammation. We hypothesized that ITLN is required for allergen-induced IL-25, IL-33, and TSLP expression. In two asthma models, Itln knockdown reduced allergen-induced increases in Il-25, Il-33, and Tslp and development of type 2 response, eosinophilic inflammation, mucus overproduction, and airway hyperresponsiveness. Itln knockdown also inhibited house dust mite (HDM)-induced early upregulation of Il-25, Il-33, and Tslp in a model solely inducing airway sensitization. Using human airway epithelial cells, we demonstrated that HDM-induced increases in ITLN led to phosphorylation of epidermal growth factor receptor and extracellular-signal regulated kinase, which were required for induction of IL-25, IL-33, and TSLP expression. In two AD models, Itln knockdown suppressed expression of Il-33, Tslp, and Th2 cytokines and eosinophilic inflammation. In humans, ITLN1 expression was significantly increased in asthmatic airways and in lesional skin of AD. We conclude that ITLN contributes to allergen-induced Il-25, Il-33, and Tslp expression in asthma and AD.

Reduced heat shock protein 70 in airway smooth muscle in patients with chronic obstructive pulmonary disease

ABSTRACT Studies demonstrated that pathophysiological abnormalities of airway smooth muscle (ASM) contribute significantly to chronic obstructive pulmonary disease (COPD) pathogenesis, the aim of this study is to investigate heat shock protein 70 (Hsp70) in ASM in COPD. ASM from 8 COPD patients and 6 controls were isolated for detection of Hsp70 using Western blot. Male adult Wister rats were exposed to mixture of cigarette smoke/air or room air for an indicated period. The lung tissues were obtained for pathological analysis, and ASM were dissected for Hsp70 detection. Normalized Hsp70 in ASM from COPD patients was significantly lower than that from controls (P <.001), and it was a significant positive correlation of Hsp70 and lung function. One-month exposure of rats to cigarette smoke/air mixture led to increased expression of Hsp70 and heat shock transcription factor (Hsf1) in ASM as compared to controls, whereas 3-month exposure caused dramatically reduced Hsp70 and Hsf1 than control animals. In addition, 3-month exposure to cigarette smoke/air mixture resulted in significantly lower Hsp70 and Hsf1 in rats ASM than 1-month exposure (P <.001), and it was a positive correlation of Hsf1 and Hsp70. Long-term cigarette smoking results in reduced expression of Hsp70 in ASM. This finding provides additional insight in understanding molecular changes in ASM during COPD pathogenesis.

Feasibility of 8-OHdG formation and hOGG1 induction in PBMCs for assessing oxidative DNA damage in the lung of COPD patients

Oxidative stress has long been recognized to play a role in chronic obstructive pulmonary disease (COPD); however, approaches for assessing oxidative stress are lacking. The objective of this study was to address the feasibility of measuring 8‐oxo‐7, 8‐dihydro‐2′‐deoxyguanosine (8‐OHdG) formation and human 8‐oxoguanine DNA glycosylase (hOGG1) induction in peripheral blood mononuclear cell (PBMC) to assess oxidative deoxyribonucleic acid (DNA) damage in the lung of smoking COPD patients.