Project description:Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and usually fatal form of interstitial lung disease (ILD). The precise molecular mechanisms of IPF remain poorly understood. However, analyses of mice receiving bleomycin (BLM) as a model of IPF established the importance of preceding inflammation for the formation of fibrosis. Periostin is a recently characterized matricellular protein involved in modulating cell functions. We recently found that periostin is highly expressed in the lung tissue of patients with IPF, suggesting that it may play a role in the process of pulmonary fibrosis. To explore this possibility, we administered BLM to periostin-deficient mice, and they subsequently showed a reduction of pulmonary fibrosis. We next determined whether this result was caused by a decrease in the preceding recruitment of neutrophils and macrophages in the lungs because of the lower production of chemokines and proinflammatory cytokines. We performed an in vitro analysis of chemokine production in lung fibroblasts, which indicated that periostin-deficient fibroblasts produced few or no chemokines in response to TNF-α compared with control samples, at least partly explaining the lack of inflammatory response and, therefore, fibrosis after BLM administration to periostin-deficient mice. In addition, we confirmed that periostin is highly expressed in the lung tissue of chemotherapeutic-agent-induced ILD as well as of patients with IPF. Taking these results together, we conclude that periostin plays a unique role as an inducer of chemokines to recruit neutrophils and macrophages important in the process of pulmonary fibrosis in BLM-administered model mice. Our results suggest a therapeutic potential for periostin in IPF and drug-induced ILD.
Project description:The oligopeptide/histidine transporter SLC15A3 (PHT2) belongs to the solute carrier protein 15 family and is mainly expressed in the membrane of lysosomes and endosomes in monocytes/macrophages. Macrophages are a key immune cell population in the development of pulmonary fibrosis. In order to examine the role of SLC15A3 in pulmonary fibrosis, we build bleomycin (BLM)-induced mouse model in wild-type (WT) mice and the Slc15a3 knockout(Slc15a3-/-) mice.
Project description:The pathogenesis of idiopathic pulmonary fibrosis is multifactorial and characterized by progressive fibrosis and excessive accumulation of extracellular matrix in the interstitium of the lung, and driven by an imbalance between anti-fibrotic and pro-fibrotic factors leading to collagen deposition. In the present study we wanted to identify proteins involved in these processes, and performed high-resolution proteomic profiling of bronchoalveolar lavage (BAL) from IPF patients and controls. The proteomic analysis of BAL demonstrated that the complement system was highly differentially regulated in IPF patients as compared with controls.
Project description:Pulmonary fibrosis is a chronic progressive form of interstitial lung disease, characterized by the histopathological pattern of usual interstitial pneumonia. Apart from aberrant alterations of protein-coding genes, dysregulation of non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs (circRNAs), is crucial to the initiation and progression of pulmonary fibrosis. CircRNAs are single-stranded RNAs that form covalently closed loops without 5' caps and 3' tails. Different from canonical splicing of mRNA, they are produced from the back-splicing of precursor mRNAs and have unique biological functions, as well as potential biomedical implications. They function as important gene regulators through multiple actions, including sponging microRNAs and proteins, regulating transcription, and splicing, as well as protein-coding and translation in a cap-independent manner. This review comprehensively summarizes the alteration and functional role of circRNAs in pulmonary fibrosis, with a focus on the involvement of the circRNA in the context of cell-specific pathophysiology. In addition, we discuss the diagnostic and therapeutic potential of targeting circRNA and their regulatory pathway mediators, which may facilitate the translation of recent advances from bench to bedside in the future.
Project description:BackgroundHyperglycemia could affect treatment response during cystic fibrosis (CF) exacerbations. We aimed to evaluate the prevalence and associations of hyperglycemia with exacerbation outcomes. We also evaluated feasibility of continuous glucose monitoring (CGM) during exacerbations.MethodsThe STOP2 study assessed efficacy and safety of different durations of intravenous antibiotics for CF exacerbations. We conducted a secondary data analysis of random glucose levels measured as part of clinical care during exacerbations. A small subset of participants also underwent CGM per research protocol. The associations between hyperglycemia, defined as random glucose ≥140 mg/dL, and changes in weight and lung function with exacerbation treatment were evaluated with linear regression after adjustment for confounding variables.ResultsGlucose levels were available for 182 STOP2 participants of mean (SD) age 31.6 (10.8) years, baseline percent predicted (pp) FEV1 53.6 (22.5); 37% had CF related diabetes and 27% were on insulin. Hyperglycemia was detected in 44% of participants. Adjusted mean difference (95% CI) was 1.34% (-1.39, 4.08) (p = 0.336) for change in ppFEV1 and 0.33 kg (-0.11, 0.78) (p = 0.145) for change in weight between hyperglycemic and non-hyperglycemic groups. Ten participants not on antidiabetic agents in the 4 weeks prior to enrollment underwent CGM; mean (SD) time spent >140 mg/dL was 24.6% (12.5) with 9/10 participants spending >4.5% time >140 mg/dL.ConclusionsHyperglycemia identified with random glucose is prevalent during CF exacerbations but not associated with changes in lung function or weight with exacerbation treatment. CGM is feasible and may provide a useful tool for hyperglycemia monitoring during exacerbations.
Project description:RationaleIdiopathic pulmonary fibrosis (IPF) is a deadly progressive disease with few treatment options. Transglutaminase 2 (TG2) is a multifunctional protein, but its function in pulmonary fibrosis is unknown.ObjectivesTo determine the role of TG2 in pulmonary fibrosis.MethodsThe fibrotic response to bleomycin was compared between wild-type and TG2 knockout mice. Transglutaminase and transglutaminase-catalyzed isopeptide bond expression was examined in formalin-fixed human lung biopsy sections by immunohistochemistry from patients with IPF. In addition, primary human lung fibroblasts were used to study TG2 function in vitro.Measurements and main resultsTG2 knockout mice developed significantly reduced fibrosis compared with wild-type mice as determined by hydroxyproline content and histologic fibrosis score (P < 0.05). TG2 expression and activity are increased in lung biopsy sections in humans with IPF compared with normal control subjects. In vitro overexpression of TG2 led to increased fibronectin deposition, whereas transglutaminase knockdown led to defects in contraction and adhesion. The profibrotic cytokine transforming growth factor-β causes an increase in membrane-localized TG2, increasing its enzymatic activity.ConclusionsTG2 is involved in pulmonary fibrosis in a mouse model and in human disease and is important in normal fibroblast function. With continued research on TG2, it may offer a new therapeutic target.
Project description:Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease of unknown etiology. Immune disorders play an important role in IPF pathogenesis. Here, we show that Th9 cells differentiate and activate in the lung tissue of patients with IPF and bleomycin (BLM)-induced lung fibrosis mice. Moreover, we found that Th9 cells promote pulmonary fibrosis in two ways. On the one hand, Th9 cells promote fibroblast differentiation, activation, and collagen secretion by secreting IL-9. On the other hand, they promote differentiation of Th0 cells into Th2 cells by secreting IL-4. Th9 cells and Th2 cells can promote each other, accelerating the Th1/Th2 imbalance and eventually forming a positive feedback of pulmonary fibrosis. In addition, we found that neutralizing IL-9 in both preventive and therapeutic settings ameliorates bleomycin-induced pulmonary fibrosis. Furthermore, we identified several critical signaling pathways involved in the effect of neutralizing IL-9 on pulmonary fibrosis by proteomics study. From an immunological perspective, we elucidated the novel role and underlying mechanism of Th9 cells in pulmonary fibrosis. Our study suggested that Th9-based immunotherapy may be employed as a treatment strategy for IPF.