Ya-Ru Wei

Real-time quantitative reverse transcription–polymerase chain reaction to detect propionibacterial ribosomal RNA in the lymph nodes of Chinese patients with sarcoidosis

The aim of this study was to investigate the diagnostic value of using the copy number of propionibacterial rRNA as a biomarker for sarcoidosis. Ribosomal RNA of Propionibacterium acnes and P. granulosum was measured by real‐time quantitative reverse transcription–polymerase chain reaction (RT–PCR) using formalin‐fixed and paraffin‐embedded tissue of lymph node biopsy from 65 Chinese patients with sarcoidosis, 45 with tuberculosis and 50 controls with other diseases (23 with non‐specific lymphadenitis and 27 with mediastinal lymph node metastasis from lung cancer). The receiver operating characteristic (ROC) curve was analysed to determine an optimal cut‐off value for diagnosis, and the diagnostic accuracy of the cut‐off value was evaluated in additional tissue samples [24 patients with sarcoidosis and 22 with tuberculosis (TB)]. P. acnes or P. granulosum rRNA was detected in 48 of the 65 sarcoidosis samples but only in four of the 45 TB samples and three of the 50 control samples. Analysis of the ROC curve revealed that an optimal cut‐off value of the copy number of propionibacterial rRNA for diagnosis of sarcoidosis was 50·5 copies/ml with a sensitivity and specificity of 73·8 and 92·6%, respectively. Based on the cut‐off value, 19 of the 24 additional sarcoidosis samples exhibited positive P. acnes or P. granulosum, whereas only one of the 22 additional TB samples was positive, resulting in a sensitivity and specificity of 79·2 and 95·5%, respectively. These findings suggest that propionibacteria might be associated with sarcoidosis granulomatous inflammation. Detection of propionibacterial rRNA by RT–PCR might possibly distinguish sarcoidosis from TB.

Establishment of the mouse model of acute exacerbation of idiopathic pulmonary fibrosis.

ABSTRACT Purpose: To explore and establish an animal model of AE-IPF. Methods: An animal model of idiopathic pulmonary fibrosis (IPF) was established using bleomycin (BLM). Then, BLM was administered a second time on day 21 to induce AE-IPF (which mimics human AE-IPF). Evaluation of the success of animal model was based on the survival of mice, as well as assessment of pathological changes in lung tissue. Preliminary investigation into the immunological mechanism of AE-IPF was also explored via the detection and identification of the inflammatory cells in mouse bronchoalveolar lavage fluid (BALF) and the concentrations of six cytokines (IL-4, IL-6, IL-10, IL-17A, MIG, and TGF-β1) in BALF supernatants, which were closely associated with IPF and AE-IPF. The intervention role of IL-17A antibody to AE was explored. Results: By week 4 after the second BLM administration, the mortality in the AE-IPF group was significantly greater (45%, 9/20) than that in stable-IPF group (0/18) (P = .0017). The average body weight in AE-IPF group was significantly lower than that in stable group (P < .0001). In AE-IPF group, inflammation and fibrosis were severer by histopathology analysis. In BALF, IL-17A, MIG (CXCL-9), IL-6, and TGF-β1 levels in AE group were significantly higher. The percentages of neutrophils and Th17 cells in BALF were significantly higher in AE group (P < .01; P = .0281). IL-17A antibody could attenuated the lung inflammation induced by twice BLM challenges. Conclusion: A mouse model of AE-IPF can be established using two administrations of BLM; Th17 cells may play a key role during the pathological process of AE-IPF.

A novel nanobody specific for respiratory surfactant protein A has potential for lung targeting

Lung-targeting drugs are thought to be potential therapies of refractory lung diseases by maximizing local drug concentrations in the lung to avoid systemic circulation. However, a major limitation in developing lung-targeted drugs is the acquirement of lung-specific ligands. Pulmonary surfactant protein A (SPA) is predominantly synthesized by type II alveolar epithelial cells, and may serve as a potential lung-targeting ligand. Here, we generated recombinant rat pulmonary SPA (rSPA) as an antigen and immunized an alpaca to produce two nanobodies (the smallest naturally occurring antibodies) specific for rSPA, designated Nb6 and Nb17. To assess these nanobodies’ potential for lung targeting, we evaluated their specificity to lung tissue and toxicity in mice. Using immunohistochemistry, we demonstrated that these anti-rSPA nanobodies selectively bound to rat lungs with high affinity. Furthermore, we intravenously injected fluorescein isothiocyanate-Nb17 in nude mice and observed its preferential accumulation in the lung to other tissues, suggesting high affinity of the nanobody for the lung. Studying acute and chronic toxicity of Nb17 revealed its safety in rats without causing apparent histological alterations. Collectively, we have generated and characterized lung-specific nanobodies, which may be applicable for lung drug delivery.

Screening for Differentially Expressed Proteins Relevant to the Differential Diagnosis of Sarcoidosis and Tuberculosis

Background In this study, we sought to identify differentially expressed proteins in the serum of patients with sarcoidosis or tuberculosis and to evaluate these proteins as markers for the differential diagnosis of sarcoidosis and sputum-negative tuberculosis. Methods Using protein microarrays, we identified 3 proteins exhibiting differential expression between patients with sarcoidosis and tuberculosis. Elevated expression of these proteins was verified using the enzyme-linked immunosorbent assay (ELISA) and was further confirmed by immunohistochemistry. Receiver operating characteristic (ROC) curve, logistic regression analysis, parallel, and serial tests were used to evaluate the diagnostic efficacy of the proteins. Results Intercellular Adhesion Molecule 1(ICAM-1) and leptin were screened for differentially expressed proteins relevant to sarcoidosis and tuberculosis. Using ROC curves, we found that ICAM-1 (cutoff value: 57740 pg/mL) had an area under the curve (AUC), sensitivity, and specificity of 0.718, 62.3%, and 79.5% respectively, while leptin (cutoff value: 1193.186 pg/mL) had an AUC, sensitivity, and specificity of 0.763, 88.3%, and 65.8%, respectively. Logistic regression analysis revealed that the AUC, sensitivity, and specificity of combined leptin and ICAM-1 were 0.787, 89.6%, and 65.8%, respectively, while those of combined leptin, ICAM-1, and body mass index (BMI) were 0.837, 90.9%, and 64.4%, respectively, which had the greatest diagnostic value. Parallel and serial tests indicated that the BMI-leptin parallel with the ICAM-1 serial was the best diagnostic method, achieving a sensitivity and specificity of 86.5% and 73.1%, respectively. Thus, our results identified elevated expression of ICAM-1 and leptin in serum and granulomas of sarcoidosis patients. Conclusions ICAM-1 and leptin were found to be potential markers for the diagnosis of sarcoidosis and differential diagnosis of sarcoidosis and sputum-negative tuberculosis.

N-acetylcysteine attenuates cigaret smoke-induced pulmonary exacerbation in a mouse model of emphysema

Abstract Objective: The purpose of this study was to investigate the effects of cigaret smoke (CS) on a mouse model of emphysema and examine the protective role of N-acetylcysteine (NAC) in the CS-induced exacerbation of pulmonary damage in the mice. Method: Particulate matter (PM) in sidestream cigaret smoke aerosol was analyzed by a scanning mobility particle sizer spectrometer. A mouse model of emphysema was established by an injection of porcine pancreatic elastase (PPE) into the trachea. Mice with emphysema were then exposed to filtered air, or sidestream CS with intragastric administration of NAC or normal saline. Mouse body weight, survival, pulmonary tissue histology, total antioxidant capacity (T-AOC) and malonaldehyde (MDA) contents in lung tissue, and inflammatory responses were examined. Results: Particles with a size of ≤346 nm constituted 99.06% of CS PM. Mice exhibited ruptured alveolar septal, alveolar fusion, significantly increased mean lining interval, and reduced mean alveolar number (all p < 0.05), 21 d after PPE injection. Exposure of mice with emphysema to CS exacerbated the pulmonary tissue damage, caused weight loss, significantly increased mortality, decreased T-AOC, elevated MDA contents in lung tissue, and increased interleukin (IL)-1β levels in bronchoalveolar lavage (BAL) fluids (all p < 0.05). Administration of NAC attenuated those CS-induced adverse effects in the mice and increased anti-inflammatory factor IL-10 levels in BAL fluids significantly (all p < 0.05). Conclusions: Exposure of mice with emphysema to CS exacerbated the pulmonary damage, and NAC reduced the CS-mediated pulmonary damage by preventing oxidative damage and reducing inflammatory responses.

Development of a non-infectious rat model of acute exacerbation of idiopathic pulmonary fibrosis

BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease with severe pulmonary fibrosis. The main cause of IPF-associated death is acute exacerbation of IPF (AE-IPF). This study aims to develop a rat model of AE-IPF by two intratracheal perfusions with bleomycin (BLM). METHODS Ninety male Sprague Dawley (SD) rats were randomized into three groups: an AE-IPF model group (BLM + BLM group), an IPF model group (BLM group), and a normal control group. Rats in the BLM + BLM group underwent a second perfusion with BLM on day 28 after the first perfusion with BLM. Rats in the other two groups received saline as the second perfusion. Six rats in each group were sacrificed on day 31, day 35, and day 42 after the first perfusion, respectively. Additional 18 rats in each group were observed for survival. RESULTS Rats in the BLM + BLM group had significantly worse pulmonary alveolar inflammation and fibrosis than rats in the BLM group. Rats in the BLM + BLM group also developed large amounts of hyaline membrane, showed high levels of albumin (ALB) and various inflammatory factors in the bronchoalveolar lavage fluid (BALF), and had markedly increased lung water content. Furthermore, rat survival was reduced in the BLM + BLM group. The pathophysiological characteristics of rats in the BLM + BLM group resemble those of patients with AE-IPF. CONCLUSIONS A second perfusion with BLM appears to induce acute exacerbation of pulmonary fibrosis and may be used to model AE-IPF in rats.

Stimulator of Interferon Genes Deficiency in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

The stimulator of interferon genes (STING) is a key adaptor protein mediating innate immune defense against DNA viruses. To investigate the role of STING in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF), we isolated primary peripheral blood mononuclear cells (PBMCs) from patients and healthy controls (HCs). Raw264.7 and A549 cells were infected with herpes simplex virus type 1 (HSV-1). Mice with bleomycin-induced lung fibrosis were infected with HSV-1 to stimulate acute exacerbation of the lung fibrosis. Global gene expression profiling revealed a substantial downregulation of interferon-regulated genes (downstream of STING) in the AE-IPF group compared with the HC and stable IPF groups. The PBMCs of the AE-IPF group showed significantly reduced STING protein levels, increased levels of endoplasmic reticulum (ER) stress markers, and elevated apoptosis. HSV-1 infection decreased STING expression and stimulated the ER stress pathways in Raw264.7 and A549 cells in a time- and dose-dependent manner. HSV-1 infection exacerbated the bleomycin-induced lung injury in mice. In the primary bone marrow-derived macrophages of mice treated with bleomycin and HSV-1, STING protein expression was substantially reduced; ER stress was stimulated. Tauroursodeoxycholic acid, a known inhibitor of ER stress, partially reversed those HSV-1-mediated adverse effects in mice with bleomycin-induced lung injury. STING levels in PBMCs increased after treatment in patients showing improvement but remained at low levels in patients with deterioration. Viral infection may trigger ER stress, resulting in STING deficiency and AE-IPF onset.

Identification of a nanobody specific to human pulmonary surfactant protein A

Nanobody (Nb) is a promising vector for targeted drug delivery. This study aims to identify an Nb that can specifically target the lung by binding human pulmonary surfactant protein A (SP-A). Human lung frozen tissue sections were used for 3 rounds of biospanning of our previously constructed Nb library for rat SP-A to establish a sub-library of Nb, which specifically bound human lung tissues. Phage-ELISA was performed to screen the sub-library to identify Nb4, which specifically bound human SP-A. The binding affinity Kd of Nb4 to recombinant human SP-A was 7.48 × 10−7 M. Nb4 (19 kDa) was stable at 30 °C–37 °C and pH 7.0–7.6 and specifically bound the SP-A in human lung tissue homogenates, human lung A549 cells, and human lung tissues, whereas didn’t react with human liver L-02 cells, kidney 293T cells, and human tissues from organs other than the lung. Nb4 accumulated in the lung of nude mice 5 minutes after a tail vein injection of Nb4 and was excreted 3 hours. Short-term exposure (one month) to Nb4 didn’t cause apparent liver and kidney toxicity in rats, whereas 3-month exposure resulted in mild liver and kidney injuries. Nb4 may be a promising vector to specifically deliver drugs to the lung.

Erratum: Identification of a nanobody specific to a human pulmonary surfactant protein A

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.