Wenbing Xu

Effect of TGF-β/Smad signaling pathway on lung myofibroblast differentiation

AbstractAim:Myofibroblasts play important roles in the pathogenesis of lung fibrosis. Transforming growth factor (TGF)-β1 has been widely recognized as a key fibrogenic cytokine. The major signaling pathway of TGF-β1 is through cytoplasmic Smad proteins. Our study investigated the role of individual TGF-β1/Smad signal proteins in mediating α-smooth muscle actin (α-SMA) gene expression, which is a well-known key marker of myofibroblast differentiation.Methods:We transiently cotransfected α-SMA promoter-luciferase fusion plasmid (p895-Luc) and Smad expression plasmids and measured Luc activity in TGF-β1-treated human fetal lung fibroblasts. We induced Smad3 knockout mice lung fibrosis by bleomycin. α-SMA protein expression was assessed by Western blotting. Collagen protein was analyzed by measuring hydroxyprolin. Myofibroblast morphology was assessed by immunohistochemistry.Results:We found that the overexpression of Smad3, not Smad2 markedly increased TGF-β1-induced α-SMA promoter activity and α-SMA protein expression in vitro, whereas the over-expression of dominant negative mutant Smad3 and Smad7 repressed TGF-β1 induced α-SMA gene expression. Compared to wild-type mice, Smad3 knockout mice showed attenuated lung fibrosis after bleomycin treatment, manifested by lower collagen production and myofibroblast differentiation.Conclusion:Our study suggested TGF-β1/Smad3 is a major pathway which regulated the myofibroblast differentiation. This result indicates a potential significance for future attempts of attenuating the progression of human lung fibrosis by the inhibition of the Smad3 cascade.

Pulmonary Manifestations of Sjögren’s Syndrome

Background: Primary Sjögren’s syndrome (PSS) is associated with various histological patterns of interstitial lung disease. Although chest images and lung function studies showed that lung involvement predominantly occurs in small airways, pathological findings were not consistent with the results of high-resolution CT (HRCT) and lung function tests. Objectives: To investigate the pathological characteristics of PSS-associated interstitial lung disease (PSS-ILD) and their relationship with HRCT lung function tests. Methods: Fourteen patients diagnosed as PSS who underwent surgical lung biopsy in Peking Union Medical College Hospital from October 2000 to October 2006 were reviewed. Histopathologic findings, radiologic findings and lung function tests were analyzed. Results:The study included 13 women. The median age was 46 years. Most patients presented with dyspnea and cough. CT scans revealed bilateral ground-glass, consolidative, reticular and nodular opacities and cyst lesions. The histological patterns included nonspecific interstitial pneumonia (NSIP) cellular pattern associated with organizing pneumonia (OP), NSIP mixed pattern associated with OP, noncaseating granulomas, chronic bronchiolitis, follicular bronchiolitis, constrictive bronchiolitis, lymphocytic interstitial pneumonia associated with follicular bronchiolitis, NSIP mixed pattern associated with follicular bronchiolitis, NSIP mixed pattern coexisting with chronic bronchiolitis, OP associated with chronic bronchiolitis, and noncaseating granulomas coexisting with OP. Treatment included prednisone and cyclophosphamide. During the follow-up period (median 38 months), most patients improved or remained stable. The patient with constrictive bronchiolitis died from progression of primary disease. Conclusions: The histopathologic patterns of PSS-ILD included lung interstitial involvement and small airway involvement or both. Corticosteroid therapy combined with cyclophosphamide was administered with a favorable response in the majority of patients.

Characterization of gene mutations and phenotypes of cystic fibrosis in Chinese patients.

Cystic fibrosis (CF) is a relatively common autosomal recessive disorder in Caucasians. CF is considered a very rare disease in Asians, and fewer than 30 Chinese CF patients are reported in the literature. We enrolled seven patients of Chinese Han origin diagnosed with CF at the Peking Union Medical College Hospital, to characterize gene mutations and phenotypes of CF in Chinese patients.

Intrathoracic Involvements of Immunoglobulin G4-Related Sclerosing Disease.

AbstractTo investigate clinical and radiological features of IgG4-related disease (IgG4-RD) patients with intrathoracic involvement.A prospective cohort study was performed and IgG4-RD patients were enrolled from January 2011 to March 2015 in Peking Union Medical College Hospital, in which the clinical and radiological characteristics of IgG4-RD patients with intrathoracic involvement were summarized.Out of total 248 cases with IgG4-RD, 87 cases had intrathoracic lesions, including 58 male cases and 29 female cases, with average age of 54.19u200a±u200a13.80 years. Hilar and mediastinal lymphadenopathy were the most common manifestations of IgG4-related intrathoracic disease, accounting for 52.9% (46/87). Other imaging findings of pulmonary disease included: solid nodular (25.3%), round-shaped ground-glass opacities (9.2%), alveolar-interstitial type (20.7%), bronchovascular type (23.0%), pleural effusion (4.6%), and pleural nodules or thickening (16.1%). Only 27 patients presented with respiratory symptoms, including cough, breathless, chest pain, and asthma. Compared with patients without intrathoracic disease, IgG4-related intrathoracic disease had higher IgG4 and C-reactive protein level, and higher incidence of allergy, fever, and multi-organ involvement. Most of lung interstitial disease, mediastinal mass, and bronchial thickening were sensitive to corticosteroid and immunosuppressant therapy, while 36.3% (8/22) of solitary nodular lesions were unresponsive to treatment. Eight patients were on no treatment, with 5 cases remained stable, 2 patients improved spontaneously, and 1 patient was lost follow-up.Intrathoracic lesions are not rare in patients with IgG4-RD, involving bronchial thickening, nodules, ground glass opacity, pleural thickening/effusion, lymphadenopathy, etc. Efficacy of corticosteroid and immunosuppressant therapy were noted in most of patients with lung interstitial disease, mediastinal mass, and bronchial thickening.

p.G970D is the most frequent CFTR mutation in Chinese patients with cystic fibrosis

Cystic fibrosis (CF), the most common life-threatening autosomal recessive disorder in Caucasians, is caused by mutations in CF transmembrane conductance regulator gene (CFTR). We and others previously identified CFTR mutations in 20 Chinese patients with CF. In this study, eight Chinese patients with a clinical diagnosis of suspected CF were newly collected and screened for CFTR mutations using a combination of conventional Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis. The CFTR mutations observed in Chinese CF patients, both reported previously and identified in the present study, were also summarized. In the newly collected patients, we identified 10 different CFTR mutations, including p.F508del, the most common CF-causing mutation in Caucasians, and three novel mutations (p.V1212Afs*15; p.L666* and p.A969A). Most notably, the previously reported p.G970D mutation was found in six patients, making it the most frequent CFTR mutation identified in Chinese CF patients thus far. In conclusion, we detected p.F508del for the first time, identified additional novel CFTR mutations and recorded the most frequent CF-causing mutation in Chinese CF patients.

Biopsy-proven IgG4-related lung disease

BackgroundImmunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory disorder that may involve single or multiple organs. Biopsy-proven lung involvement of this disease is occasionally reported, but not well understood.MethodsPatients with the diagnosis of biopsy-proven IgG4-related lung disease (IgG4-RLD) from Peking Union Medical College Hospital between January 2011 and July 2015 were retrospectively analyzed. Age, sex, clinical symptoms, laboratory findings, pulmonary function test results, chest CT tests, positron emission tomography (PET) examinations, treatments and prognoses were retrieved from medical records and analyzed.ResultsSeventeen patients were included in this study (mean age: 44.8u2009±u200915.0xa0years). Ten patients were diagnosed via surgery, and 7 patients were diagnosed via percutaneous transthoracic core-needle lung biopsy. Extrapulmonary involvement was observed in only one patient. The clinical symptoms included cough, fever, dyspnea, chest pain and hemoptysis. The serum IgG4 concentration was elevated in 7/13 patients (mean: 1955u2009±u20091968xa0mg/L). The chest CT findings included mainly nodules and masses with spiculated borders, alveolar consolidations with air bronchograms, and ground glass opacities with or without reticular opacities. PET scans indicated increased standardized uptake values, and 7/8 patients were correctly diagnosed with benign inflammation. Corticosteroids and immunosuppressants were administered to 14/17 patients and effectively alleviated the disease.ConclusionsIn biopsy-proven IgG4-RLD, a normal serum IgG4 concentration is commonly seen, while extrapulmonary involvement is infrequent. Alveolar consolidation with air bronchograms is an important imaging finding of IgG4-RLD, which has not been emphasized before.

Clinical Features and Prognosis in 21 Patients with Extrinsic Allergic Alveolitis

OBJECTIVEnTo assess the spectrum of causes, clinical features, differences between disease phases, and prognosis of extrinsic allergic alveolitis (EAA).nnnMETHODSnPatients with EAA diagnosed at Peking Union Medical College Hospital from August 1983 to May 2007 were analyzed retrospectively. Their medical records were examined to gather clinical, laboratorial, radiological, and histopathological data. Patients were divided to three phases (acute, subacute, and chronic) according to clinical presentations. Follow-up data regarding treatment response, subsequent radiological and pulmonary function studies, and clinical outcomes were collected.nnnRESULTSnA total of 21 cases were enrolled. Among them, 11 were subacute, 10 were chronic. The most common exposure was pet birds (6 cases, 28.6%). The primary abnormality of pulmonary function was restriction and/or reduction in diffusing capacity (12 cases, 63.2%). The most common findings on high-resolution computed tomography (HRCT) were ground-glass opacities (13 cases, 68.4%) and centrilobular nodules (8 cases, 42.1%). Airway obstruction in pulmonary function test, emphysema, lung cysts, and fibrosis on HRCT were more frequently seen in chronic than in subacute patients, though the differences were not statistically significant. Bronchoalveolar lavage fluid (BALF) showed lymphocytosis. The total cell count and the percentage of neutrophils were significantly higher in subacute than in chronic patients (P<0.05). Nonnecrotizing granulomas were seen in 8 (47.1%) cases. Improvement or normalization in symptoms, radiography, and pulmonary function test after treatment were seen in all 18 patients with available follow-up data. Five patients recurred.nnnCONCLUSIONSnThe characteristic abnormalities of pulmonary function, findings on HRCT, and pathology are essential for all phases of EAA, and the atypical manifestations such as obstruction and fibrosis can also be present frequently, particularly in chronic cases. Differential cell counts of BALF are related to the phase of the disease. The treatment response and prognosis of EAA are good.

Impaired lipid metabolism in idiopathic pulmonary alveolar proteinosis

BackgroundIt is well known that lipids abnormally accumulate in the alveoli during idiopathic pulmonary alveolar proteinosis (PAP). It is unclear, however, whether lipids also abnormally accumulate in serum. This study investigated the serum lipid panels in idiopathic PAP patients and explored the relationships between serum levels and the severity of idiopathic PAP.Methods and ResultsClinical data including the level of serum lipids were evaluated in 33 non-diabetic idiopathic PAP patients and 157 healthy volunteers. Serum levels of triglyceride were higher in PAP patients than in healthy subjects (median: 192.00 mg/dl (P25: 104.36, P75: 219.00) vs 119.56 mg/dl (P25: 78.81, P75: 193.03), P < 0.05), while high-density lipoprotein cholesterol (HDL-C) levels were lower in patients than in the control group (42.50 ± 10.30 vs 51.34 ± 12.06 mg/dl, P < 0.01). Forced expiratory volume in one second and forced vital capacity in hypertriglyceridemia patients were lower than those in patients with normal triglyceride. Serum LDL-C and HDL-C ratio correlated negatively with PaO2 (r = -0.403, P < 0.05) and positively with lactate dehydrogenase (r = 0.381, P < 0.05).ConclusionsPAP associates with high triglyceride and low HDL levels in the serum, and these lipids provide potential intervention strategy for treatment.

Pathological and High Resolution CT Findings in Churg-Strauss Syndrome

OBJECTIVEnTo investigate the Churg-Strauss syndrome (CSS) associated lung involvement, concentrating on clinical characteristics, pathological findings of lung involvements, response to treatment, and prognosis.nnnMETHODSnWe retrospectively analyzed the characters of the clinical manifestations, thin-section CT and pathological findings of CSS. The study involved 16 patients. Clinical data were obtained by chart review. All patients underwent transbronchial lung biopsy (TBLB). Six of them underwent surgical lung biopsy as well.nnnRESULTSnThe patients included 7 men and 9 women, aged from 14 to 61 years (median, 47.5 years). Extrathoracic organs involved included nervous system (7/16) and skin (5/16). Respiratory symptoms included cough (12/16), exertional dyspnea (11/16), hemoptysis (4/16), and chest pain (3/16). CT findings included bilateral ground-glass opacities (12/16), bilateral patchy opacities (12/16), and centrilobular nodules (6/16). The pathological findings of TBLB demonstrated increased eosinophils (3/16), vasculitis (3/16), and interstitial pneumonia (16/16). The pathological findings of surgical lung biopsy of 6 cases showed necrotizing vasculitis in 4 cases, capillaries in 5, eosinophilic pneumonia in 3, granulomas in 2, and airway abnormalities in 3. All patients improved in symptoms after therapy during the study period (range, 3 to 51 months; median, 15 months).nnnCONCLUSIONSnAsthma may be present in CSS patient when there is bronchial involvement. Ground-glass opacities and consolidation seen on high-resolution CT reflect the presence of eosinophilic pneumonia, vasculitis, and pulmonary alveolar hemorrhage. TBLB has significant limitations for the diagnosis of CSS. Early diagnosis and therapy can result in satisfactory prognosis.

CD4+ and CD8+ T lymphocytes in lung tissue of NSIP: Correlation with T lymphocytes in BALF

BACKGROUNDnNonspecific interstitial pneumonia (NSIP) is characterized by the interstitial infiltration T lymphocytes (TLs). Bronchoalveolar lavage fluid (BALF) has been used to analyze the inflammatory cells infiltrating in lung. The controversy about whether the BALF cellular profile reflects T lymphocytes in lung tissue still persists. Some studies found a positive correlation of cell composition between BALF and lung tissue, but others gave opposite conclusion.nnnOBJECTIVEnTo investigate CD4+ and CD8+ T lymphocytes distribution in lung tissue of NSIP and the relationship with T lymphocytes in bronchoalveolar lavage.nnnMETHODSnThirty-seven patients diagnosed as NSIP were included. The pathological and BALF date were reviewed. The characteristics of TLs infiltration in different lung regions were investigated.nnnRESULTSnThe study included 28 women. The median age was 48 years. In lung tissue, CD4+ and CD8+ lymphocytes (counts/0.1mm2) were separately accounted in lymphoid follicle region (156.51 ± 90.70 vs 85.30 ± 43.75), small blood vessel region (66.58 ± 31.99 vs 58.43 ± 30.24), interstitial region (37.60 ± 19.40 vs 47.12 ± 33.42) and small airway region (26.59 ± 17.04 vs 40.18 ± 34.02). CD4+/CD8+ ratios in lymphoid follicle and small vessel > 1, in interstitium and small airway <1. The number of CD8+ lymphocytes in BALF was correlated with CD8+ lymphocytes around small airway (r = 0.360, p = 0.029) and in interstitial region (r = 0.451, p = 0.005). CD4+/CD8+ ratio in BALF was correlated with that in small airway region (r = 0.437, p = 0.007) and interstitial region (r = 0.468, p = 0.003).nnnCONCLUSIONSnIn NSIP, T lymphocytes were distributed in different regions of lung tissue. The CD8+ T lymphocytes and CD4+/CD8+ ratio in BALF reflect those in interstitium regions and around small airway of the lung.