BACKGROUND. Whether airspace biomarkers add value to plasma biomarkers in studying ARDS is not well understood. Mesenchymal stromal cells (MSCs) are an investigational therapy for ARDS, and airspace biomarkers may provide mechanistic evidence for MSCs' impact in patients with ARDS. METHODS. We carried out a nested cohort study within a phase 2a safety trial of treatment with allogeneic MSCs for moderate to severe ARDS. Non-bronchoscopic bronchoalveolar lavage and plasma samples were collected 48 hours after study drug infusion. Airspace and plasma biomarker concentrations were compared between the MSC (n = 17) and placebo (n = 10) treatment arms, and correlation between the two compartments was tested. Airspace biomarkers were also tested for associations with clinical and radiographic outcomes. RESULTS. Compared to placebo, MSC treatment significantly reduced airspace total protein, angiopoietin-2 (Ang-2), interleukin-6 (IL-6), and soluble tumor necrosis factor receptor-1 concentrations. Plasma biomarkers did not differ between groups. Each 10-fold increase in airspace Ang-2 was independently associated with 6.7 fewer days alive and free of mechanical ventilation (95% CI -12.3 to -1.0, p = 0.023), and each 10-fold increase in airspace receptor for advanced glycation end-products (RAGE) was independently associated with a 6.6 point increase in day 3 radiographic assessment of lung edema score (95% CI 2.4 to 10.7, p = 0.004). CONCLUSIONS. MSCs reduced biological evidence of lung injury in patients with ARDS. Biomarkers from the airspaces provide additional value for studying pathogenesis, treatment effects, and outcomes in ARDS. TRIAL REGISTRATION. NCT02097641 FUNDING. National Heart, Lung, and Blood Institute
Katherine D. Wick, Aleksandra Leligdowicz, Hanjing Zhuo, Lorraine B. Ware, Michael A. Matthay
Right ventricular (RV) fibrosis is a key feature of maladaptive RV hypertrophy and dysfunction and is associated with poor outcomes in pulmonary hypertension (PH). However, mechanisms and therapeutic strategies to mitigate RV fibrosis remain unrealized. Previously, we identified that cardiac fibroblast α7 nicotinic acetylcholine receptor (α7 nAChR) drives smoking induced RV fibrosis. Here we sought to define the role of α7 nAChR in RV dysfunction and fibrosis in the settings of RV pressure overload as seen in PH. We show that RV tissue from PH patients has increased collagen content and ACh expression. Using experimental rat model of PH, we demonstrate that RV fibrosis and dysfunction are associated with increases in ACh and α7 nAChR expression in the RV but not in the LV. In vitro studies show that α7 nAChR activation leads to an increase in adult ventricular fibroblast proliferation and collagen content mediated by a Ca2+/ epidermal growth factor receptor (EGFR) signaling mechanism. Pharmacological antagonism of nAChR decreases RV collagen content and improves RV function in the PH model. Further, mice lacking α7 nAChR exhibit improved RV diastolic function and have lower RV collagen content in response to persistently increased RV afterload, compared to wild-type controls. These finding indicate that enhanced α7 nAChR signaling is an important mechanism underlying RV fibrosis and dysfunction, and targeted inhibition of α7 nAChR is a novel therapeutic strategy in the setting of increased RV afterload.
Alexander Vang, Denielli da Silva Gonçalves Bos, Ana Fernandez-Nicolas, Peng Zhang, Alan R. Morrison, Thomas J. Mancini, Richard T. Clements, Iuliia Polina, Michael W. Cypress, Bong Sook Jhun, Edward Hawrot, Ulrike Mende, Jin O-Uchi, Gaurav Choudhary
Idiopathic Pulmonary Fibrosis (IPF) is characterized by aberrant repair that diminishes lung function via mechanisms that remain poorly understood. C-C chemokine receptor (CCR10) and its ligand, CCL28, were both elevated in IPF compared with normal donors. CCR10 was highly expressed by various cells from IPF lungs, most notably stage-specific embryonic antigen (SSEA)-4+ mesenchymal progenitor cells (MPCs). In vitro, CCL28 promoted the proliferation of CCR10+ MPCs while CRISPR-Cas9-mediated targeting of CCR10 resulted in the death of MPCs. Following the intravenous injection of various cells from IPF lungs into immunodeficient (NSG) mice, human CCR10+ cells initiated and maintained fibrosis in NSG mice. Eph receptor A3 (EphA3) was among the highest expressed receptor tyrosine kinases detected on IPF CCR10+ cells. Ifabotuzumab-targeted killing of EphA3+ cells significantly reduced the numbers of CCR10+ cells and ameliorated pulmonary fibrosis in humanized NSG mice. Thus, human CCR10+ cells promote pulmonary fibrosis and EphA3 mAb-directed elimination of these cells inhibits lung fibrosis.
Miriam S. Hohmann, David M. Habiel, Milena S. Espindola, Guanling Huang, Isabelle Jones, Rohan Narayanan, Ana Lucia Coelho, Justin M. Oldham, Imre Noth, Shwu-Fan Ma, Adrianne Kurkciyan, Jonathan L. McQualter, Gianni Carraro, Barry Stripp, Peter Chen, Dianhua Jiang, Paul W. Noble, William Parks, John Woronicz, Geoffrey Yarranton, Lynne A. Murray, Cory M. Hogaboam
The epithelial cell-derived cytokines IL-25, IL-33 and TSLP initiate type 2 inflammation in allergic diseases including asthma. However, the signaling pathway regulating these cytokines expression remains elusive. Since microRNAs are pivotal regulators of gene expression, we profiled microRNA expression in bronchial epithelial brushings from type 2-low and type 2-high asthma patients. MiR-206 was the most highly expressed epithelial microRNA in type 2-high asthma relative to type 2-low asthma but was downregulated in both subsets compared with healthy controls. CD39, an ectonucleotidase degrading ATP, was a target of miR-206 and upregulated in asthma. Allergen-induced acute extracellular ATP accumulation led to miR-206 downregulation and CD39 upregulation in human bronchial epithelial cells, forming a feedback loop to eliminate excessive ATP. Airway ATP levels were markedly elevated and strongly correlated with IL-25 and TSLP expression in asthma patients. Intriguingly, airway miR-206 antagonism increased Cd39 expression, reduced ATP accumulation, suppressed Il-25, Il-33, Tslp expression and group 2 innate lymphoid cell expansion, and alleviated type 2 inflammation in a mouse model of allergic airway inflammation. In contrast, airway miR-206 overexpression had opposite effects. Overall, epithelial miR-206 upregulates airway IL-25, TSLP expression by targeting CD39-extracellular ATP axis, which represents a novel therapeutic target in type 2-high asthma.
Kan Zhang, Yuchen Feng, Yuxia Liang, Wenliang Wu, Chenli Chang, Dian Chen, Shengchong Chen, Jiali Gao, Gongqi Chen, Lingling Yi, Dan Cheng, Guohua Zhen
BACKGROUND. Early diagnosis and treatment are key to the long-term survival of lung cancer patients. Although CT has significantly contributed to the early diagnosis of lung cancer, there are still consequences of excessive or delayed treatment. By improving the sensitivity and specificity of circulating tumour cell (CTC) detection, a new solution was proposed for differentiating benign from malignant pulmonary nodules. METHODS. In this study, we used telomerase reverse transcriptase-based CTC detection (TBCD) to distinguish benign from malignant pulmonary nodules <2 cm and compared this method with the pathological diagnosis as the gold standard. FlowSight and FISH were used to confirm the CTCs detected by TBCD. RESULTS. Our results suggest that CTCs based on TBCD can be used as an independent biomarker to distinguish benign from malignant nodules and are significantly superior to serum tumour markers. When the detection threshold was 1, the detection sensitivity and specificity of CTC diagnosis were 0.854 and 0.839, respectively. For pulmonary nodules ≦1 cm and 1-2 cm, the sensitivity and specificity of CTCs were both higher than 77%. Additionally, the diagnostic ability of CTC-assisted CT was compared by CT detection. The results showed that CT combined with CTCs could significantly improve the differentiation ability of benign and malignant nodules in lung nodules <2 cm, and the sensitivity and specificity could reach 0.899 and 0.839, respectively. CONCLUSIONS. In conclusion, TBCD can effectively diagnose pulmonary nodules and be used as an effective auxiliary diagnostic scheme for CT diagnosis. FUNDING. National Key Research and Development Project grants No. 2019YFC1315700 and No. 2017YFC1308702, CAMS Initiative for Innovative Medicine grants No. 2017-I2M-1-005, and National Natural Science Foundation of China grants No. 81472013.
Wen Zhang, Xinchun Duan, Zhenrong Zhang, Zhenrong Yang, Changyun Zhao, Chunzi Liang, Zhidong Liu, Shujun Cheng, Kaitai Zhang
Pleural fibrosis is defined as an excessive deposition of extracellular matrix that results in destruction of the normal pleural tissue architecture and compromised function. Tuberculous pleurisy, asbestos injury and rheumatoid pleurisy are main causes of pleural fibrosis. Pleural mesothelial cells (PMCs) play a key role in pleural fibrosis. However, detailed mechanisms are poorly understood. Serine/arginine-rich protein SRSF6 belongs to a family of highly conserved RNA-binding splicing-factor proteins. Based on its known functions, SRSF6 should be expected to play a role in fibrotic diseases. However, the role of SRSF6 in pleural fibrosis is totally unknown. In this study, SRSF6 protein was found to be increased in cells of tuberculous pleural effusions (TBPE) from patients, and decellularized TBPE, bleomycin and TGFB1 were confirmed to increase SRSF6 levels in PMCs. In vitro, SRSF6 mediated PMC proliferation and synthesis of the main fibrotic protein COL1A2. In vivo, SRSF6 inhibition prevented mouse experimental pleural fibrosis. Lastly, activated-SMAD2/3, increased-SOX4 and depressed-microRNA-506-3p were associated with SRSF6 up-regulation in PMCs. These observations support a model where SRSF6 induces pleural fibrosis through a cluster pathway including SRSF6/WNT5A and SRSF6/SMAD1/5/9 signaling. In conclusion, we propose inhibition of the splicing factor SRSF6 as a strategy for treatment of pleural fibrosis.
Li-Mei Liang, Liang Xiong, Pei-Pei Cheng, Shuai-Jun Chen, Xiao Feng, Ya-Ya Zhou, Qian Niu, Meng Wang, Qianlan Chen, Lin-Jie Song, Fan Yu, Xin-Liang He, Fei Xiang, Xiaorong Wang, Hong Ye, Wan-Li Ma
The molecular mechanisms by which endothelial cells (ECs) regulate pulmonary vascularization and contribute to alveolar epithelial cell development during lung morphogenesis remain unknown. We tested the hypothesis that delta-like 4 (DLL4), an EC Notch ligand, is critical for alveolarization by combining lung mapping and functional studies in human tissue and DLL4-haploinsufficient mice (Dll4+/lacz). DLL4 expressed in a PECAM-restricted manner in capillaries, arteries, and the alveolar septum from the canalicular to alveolar stage in mice and humans. Dll4 haploinsufficiency resulted in exuberant, nondirectional vascular patterning at E17.5 and P6, followed by smaller capillaries and fewer intermediate blood vessels at P14. Vascular defects coincided with polarization of lung EC expression toward JAG1-NICD-HES1 signature and decreased tip cell-like (Car4) markers. Dll4+/lacZ mice had impaired terminal bronchiole development at the canalicular stage and impaired alveolarization upon lung maturity. We discovered that alveolar type I cell (Aqp5) markers progressively decreased in Dll4+/lacZ mice after birth. Moreover, in human lung EC, DLL4 deficiency programmed a hypersprouting angiogenic phenotype cell autonomously. In conclusion, DLL4 is expressed from the canalicular to alveolar stage in mice and humans, and Dll4 haploinsufficiency programs dysmorphic microvascularization, impairing alveolarization. Our study reveals an obligate role for DLL4-regulated angiogenesis in distal lung morphogenesis.
Sheng Xia, Heather L. Menden, Nick Townley, Sherry M. Mabry, Jeffrey Johnston, Michael F. Nyp, Daniel P. Heruth, Thomas Korfhagen, Venkatesh Sampath
Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease. We previously identified fibrogenic mesenchymal progenitor cells (MPCs) in the lungs of IPF patients that serve as an obligatory driver of progressive fibrosis. Recent single cell RNA sequencing work revealed that IPF MPCs with the highest transcriptomic network entropy differ the most from control MPCs; and that CD44 was a marker of these IPF MPCs. We hypothesize that IPF MPCs with high CD44 (CD44hi) expression will display enhanced fibrogenicity. We demonstrate that CD44 expressing MPCs are present at the periphery of the IPF fibroblastic focus, placing them in regions of active fibrogenesis. In a humanized mouse xenograft model, CD44hi IPF MPCs are more fibrogenic than CD44lo IPF MPCs and knock-down of CD44 diminishes their fibrogenicity. CD44hi IPF MPCs display increased expression of pluripotency markers and self-renewal compared to CD44lo IPF MPCs; properties potentiated by IL-8. The mechanism involves the accumulation of CD44 within the nucleus where it associates with the chromatin modulator protein BRG1 and the Zeb1 transcription factor. This CD44/BRG1/Zeb1 nuclear protein complex targets the Sox2 gene promoting its upregulation and self-renewal. Our data implicates CD44 interaction with the epigenetic modulator protein Brg1 in conveying IPF MPCs with cell-autonomous fibrogenicity.
Libang Yang, Hong Xia, Karen A. Smith, Adam Gilbertsen, Daniel Beisang, Jonathan Kuo, Peter B. Bitterman, Craig A. Henke
High mortality in acute lung injury (ALI) results from sustained proinflammatory signaling by alveolar receptors, such as TNF-α receptor type 1 (TNFR1). Factors that determine the sustained signaling are not known. Unexpectedly, optical imaging of live alveoli revealed a major TNF-α–induced surge of alveolar TNFR1 due to a Ca2+-dependent mechanism that decreased the cortical actin fence. Mouse mortality due to inhaled LPS was associated with cofilin activation, actin loss, and the TNFR1 surge. The constitutively active form of the GTPase, Rac1 (V12Rac1), given intranasally (i.n.) as a noncovalent construct with a cell-permeable peptide, enhanced alveolar filamentous actin (F-actin) and blocked the TNFR1 surge. V12Rac1 also protected against ALI-induced mortality resulting from i.n. instillation of LPS or of Pseudomonas aeruginosa. We propose a potentially new therapeutic paradigm in which actin enhancement by exogenous Rac1 strengthens the alveolar actin fence, protecting against proinflammatory receptor hyperexpression, and therefore blocking ALI.
Galina A. Gusarova, Shonit R. Das, Mohammad N. Islam, Kristin Westphalen, Guangchun Jin, Igor O. Shmarakov, Li Li, Sunita Bhattacharya, Jahar Bhattacharya
Compromised regenerative capacity of lung epithelial cells can lead to cellular senescence, which may precipitate fibrosis. While increased markers of senescence have been reported in idiopathic pulmonary fibrosis (IPF), the origin and identity of these senescent cells remain unclear, and tools to characterize context-specific cellular senescence in human lung are lacking. We observed that the senescent marker p16 is predominantly localized to bronchiolized epithelial structures in scarred regions of IPF and systemic sclerosis associated interstitial lung disease ILD (SSc-ILD) lung tissue, overlapping with the basal epithelial markers Keratin 5 and Keratin 17. Using in vitro models, we derived transcriptional signatures of senescence programming specific to different types of lung epithelial cells, and interrogated these signatures in a single-cell RNA-seq data set derived from control, IPF, and SSc-ILD lung tissue. We identified a population of basal epithelial cells defined by, and enriched for, markers of cellular senescence, and identified candidate markers specific to senescent basal epithelial cells in ILD that can enable future functional studies. Notably, gene expression of these cells significantly overlaps with terminally differentiating cells in stratified epithelia, where it is driven by p53 activation as part of the senescence program.
Daryle J. DePianto, Jason A. Vander Heiden, Katrina B. Morshead, Kai-Hui Sun, Zora Modrusan, Grace Teng, Paul J. Wolters, Joseph R. Arron
No posts were found with this tag.