Idiopathic Pulmonary Fibrosis
Fatty acid metabolism-related genes in bronchoalveolar lavage fluid unveil prognostic and immune infiltration in idiopathic pulmonary fibrosis
Front Endocrinol (Lausanne). 2022 Oct 4;13:1001563. doi: 10.3389/fendo.2022.1001563. eCollection 2022.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive condition with an unfavorable prognosis. A recent study has demonstrated that IPF patients exhibit characteristic alterations in the fatty acid metabolism in their lungs, suggesting an association with IPF pathogenesis. Therefore, in this study, we have explored whether the gene signature associated with fatty acid metabolism could be used as a reliable biological marker for predicting the survival of IPF patients.
METHODS: Data on the fatty acid metabolism-related genes (FAMRGs) were extracted from databases like Kyoto Encyclopedia of Genes and Genomes (KEGG), Hallmark, and Reactome pathway. The GSE70866 dataset with information on IPF patients was retrieved from the Gene Expression Omnibus (GEO). Next, the consensus clustering method was used to identify novel molecular subgroups. Gene Set Enrichment Analysis (GSEA) was performed to understand the mechanisms involved. The Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) algorithm was used to evaluate the level of immune cell infiltration in the identified subgroups based on gene expression signatures of immune cells. Finally, the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate Cox regression analysis were performed to develop a prognostic risk model.
RESULTS: The gene expression signature associated with fatty acid metabolism was used to create two subgroups with significantly different prognoses. GSEA reveals that immune-related pathways were significantly altered between the two subgroups, and the two subgroups had different metabolic characteristics. High infiltration of immune cells, mainly activated NK cells, monocytes, and activated mast cells, was observed in the subgroup with a poor prognosis. A risk model based on FAMRGs had an excellent ability to predict the prognosis of IPF. The nomogram constructed using the clinical features and the risk model could accurately predict the prognosis of IPF patients.
CONCLUSION: The fatty acid metabolism-related gene expression signature could be used as a potential biological marker for predicting clinical outcomes and the level of infiltration of immune cells. This could eventually enhance the accuracy of the treatment of IPF patients.
PMID:36267568 | PMC:PMC9576944 | DOI:10.3389/fendo.2022.1001563
A lung targeted miR-29 mimic as a therapy for pulmonary fibrosis
EBioMedicine. 2022 Oct 17;85:104304. doi: 10.1016/j.ebiom.2022.104304. Online ahead of print.
ABSTRACT
BACKGROUND: MicroRNAs are non-coding RNAs that negatively regulate gene networks. Previously, we reported that systemically delivered miR-29 mimic MRG-201 reduced fibrosis in animal models, supporting the consideration of miR-29-based therapies for idiopathic pulmonary fibrosis (IPF).
METHODS: We generated MRG-229, a next-generation miR-29 mimic based on MRG-201 with improved chemical stability due to additional sugar modifications and conjugation with the internalization moiety BiPPB (PDGFbetaR-specific bicyclic peptide)1. We investigated the anti-fibrotic efficacy of MRG-229 on TGF-β1 treated human lung fibroblasts (NHLFs), human precision cut lung slices (hPCLS), and in vivo bleomycin studies; toxicology was assessed in two animal models, rats, and non-human primates. Finally, we examined miR-29b levels in a cohort of 46 and 213 patients with IPF diagnosis recruited from Yale and Nottingham Universities (Profile Cohort), respectively.
FINDINGS: The peptide-conjugated MRG-229 mimic decreased expression of pro-fibrotic genes and reduced collagen production in each model. In bleomycin-treated mice, the peptide-conjugated MRG-229 mimic downregulated profibrotic gene programs at doses more than ten-fold lower than the original compound. In rats and non-human primates, the peptide-conjugated MRG-229 mimic was well tolerated at clinically relevant doses with no adverse findings observed. In human peripheral blood from IPF patients decreased miR-29 concentrations were associated with increased mortality in two cohorts potentially identified as a target population for treatment.
INTERPRETATION: Collectively, our results provide support for the development of the peptide-conjugated MRG-229 mimic as a potential therapy in humans with IPF.
FUNDING: This work was supported by NIH NHLBI grants UH3HL123886, R01HL127349, R01HL141852, U01HL145567.
PMID:36265417 | DOI:10.1016/j.ebiom.2022.104304
Inhibition of glutamine transporter ASCT2 mitigates bleomycin-induced pulmonary fibrosis in mice
Acta Histochem. 2022 Oct 17;124(8):151961. doi: 10.1016/j.acthis.2022.151961. Online ahead of print.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) represents a fatal pulmonary disease. Its mechanisms remain unclear and effective therapies are urgently needed. Glutaminolysis is involved in IPF pathology, but little is known about the role of ASCT2 responsible for cellular uptake of glutamine in IPF. We investigated the role of ASCT2 and its therapeutic implication in IPF through knockdown of ASCT2 in mice.
METHODS: Mouse IPF model was established through a single intratracheal administration of bleomycin, and lentivirus-coated ASCT2 siRNA was administrated into mice via caudal vein for knockdown of ASCT2. Mouse blood and lung tissues were collected for biochemical, histological, and molecular examinations.
RESULTS: ASCT2 siRNA significantly lowered ASCT2 expression in mouse lung tissues. Knockdown of ASCT2 reduced pulmonary levels of glutamic acid, α-ketoglutarate, glutathione and ATP, mitigated pulmonary histological injury, and reduced serum concentrations of pulmonary injury parameters including SP-A, SP-D, KL-6 and CCL18 in IPF mice. Moreover, serum levels of fibrotic parameters HA, LN, PC-III and IV-C were lowered by ASCT2 depletion. Collagen production and pulmonary hydroxyproline levels were also decreased by ASCT2 siRNA in IPF mice, which was concomitant with downregulation of α-smooth muscle actin, collagen type Iα1 and transforming growth factor-β receptor II. Furthermore, ASCT2 deficiency downregulated the mRNA and protein expression of inflammatory cytokines IL-1β and TNF-α as well as macrophage marker F4/80 in lung tissues of IPF mice.
CONCLUSIONS: Inhibition of ASCT2 effectively mitigated pulmonary injury, fibrosis and inflammation in mice with bleomycin-induced IPF. ASCT2 could be a novel therapeutic target for treatment of IPF.
PMID:36265204 | DOI:10.1016/j.acthis.2022.151961
A Novel 5-Methylcytosine- and Immune-Related Prognostic Signature Is a Potential Marker of Idiopathic Pulmonary Fibrosis
Comput Math Methods Med. 2022 Oct 8;2022:1685384. doi: 10.1155/2022/1685384. eCollection 2022.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is the most common and highly lethal pulmonary interstitial lung disease. The current study is aimed at investigating reliable markers suitable for the treatment and identification of IPF. This study constructed the first 5-methylcytosine- (m5C-) and immune-related prognostic signature (m5CPS) based on coexpressed genes of m5C regulatory genes and immune-related genes. The m5CPS was established using the training cohort (n = 68) and verified using the test (n = 44) and validation (n = 64) cohorts. The area under the curve (AUC) values were utilized to evaluate the accuracy of m5CPS in predicting the survival of IPF patients. The Kaplan-Meier curves and Cox regression analyses were used to assess the prognostic effect of m5CPS. The AUC was utilized to evaluate the reliability of m5CPS in distinguishing IPF patients from healthy individuals. In terms of the results, m5CPS could predict the one-, three-, and five-year survival rates of IPF patients with high accuracy (AUC = .803-.973). In fact, m5CPS is not only an independent indicator of the poor prognosis of IPF patients (hazard ratio > 1; p < .05) but can also distinguish IPF patients from healthy individuals (AUC = .862). Also, m5CPS may affect the immune response and inflammatory response, and it was positively associated with the infiltration levels of active mast cells (p < .05). In sum, the current study establishes a novel m5CPS for IPF and reveals the role of m5CPS as a reliable marker for predicting the prognosis and disease status of IPF patients.
PMID:36262873 | PMC:PMC9574547 | DOI:10.1155/2022/1685384
DDR1 activation in macrophage promotes IPF by regulating NLRP3 inflammasome and macrophage reaction
Int Immunopharmacol. 2022 Oct 15;113(Pt A):109294. doi: 10.1016/j.intimp.2022.109294. Online ahead of print.
ABSTRACT
BACKGROUND: Discoidin Domain Receptor1 (DDR1) is a member of receptor tyrosine kinases (RTKs) which have been reported to be associated with idiopathic pulmonary fibrosis (IPF), but the mechanism remains unclear.
METHODS: Bleomycin-induced IPF mice model was performed in this study, and two DDR1 inhibitors were administered in vivo, to investigate the role of DDR1 in IPF. Lentivirus mediated DDR1-/- stable Raw264.7 macrophage cell line or DDR1 inhibitors treatment in vitro, to study the effect of DDR1 on inflammasome activation and macrophage responses. All of the mechanisms were further tested in the lung sections of IPF patients.
RESULT: Here, we reported that: (i) Both specific inhibitors of DDR1 dramatically alleviated the symptoms of bleomycin-induced IPF models. (ii) Immunofluorescence staining showed that DDR1 signaling is activated in macrophages. In vivo molecular biological analysis proved that DDR1 activation exacerbates IPF inflammation through inflammasome signaling, macrophage activation, and M1/M2 polarization. (iii) Extracellular matrix (ECM) such as Collagen 1 activates DDR1 in macrophage cell line Raw264.7 in vitro, to mediate inflammasome activation and macrophage responses. (iv) DDR1 activation in macrophage was confirmed in IPF patients' samples, which could be one of the mechanisms for the pathogenesis of IPF.
DISCUSSION: In this study, we firstly reported DDR1 activation in macrophages to play a role in IPF via inflammasome activation and macrophage responses. In addition, DDR1 inhibitors DDR1-IN-1 and DDR1-IN-2 exerted significant anti-inflammatory and anti-fibrotic effects in IPF, all of which provide a potentially effective therapeutic medication for clinical IPF treatment.
PMID:36257259 | DOI:10.1016/j.intimp.2022.109294
MSGA+RF: A two-stage deep learning-based multi-scale guided attention models to diagnose idiopathic pulmonary fibrosis from CT images
Med Phys. 2022 Oct 18. doi: 10.1002/mp.16053. Online ahead of print.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible, and usually fatal lung disease of unknown reasons, generally affecting the elderly population. Early diagnosis of IPF is crucial for triaging patients' treatment planning into anti-fibrotic treatment or treatments for other causes of pulmonary fibrosis. However, current IPF diagnosis workflow is complicated and time-consuming, which involves collaborative efforts from radiologists, pathologists, and clinicians and it is largely subject to inter-observer variability.
PURPOSE: The purpose of this work is to develop a deep learning-based automated system that can diagnose subjects with IPF among subjects with interstitial lung disease (ILD) using an axial chest computed tomography (CT) scan. This work can potentially enable timely diagnosis decisions and reduce inter-observer variability.
METHODS: Our dataset contains CT scans from 349 IPF patients and 529 non-IPF ILD patients. We used 80% of the dataset for training and validation purposes and 20% as the holdout test set. We proposed a two-stage model: at stage one, we built a Multi-Scale, domain knowledge-Guided Attention model (MSGA) that encouraged the model to focus on specific areas of interest to enhance model explainability, including both high- and medium- resolution attentions; at stage two, we collected the output from MSGA and constructed a random forest (RF) classifier for patient-level diagnosis, to further boost model accuracy. RF classifier is utilized as a final decision stage since it is interpretable, computationally fast, and can handle correlated variables. Model utility was examined by (1) accuracy, represented by the area under the receiver operating characteristic curve (AUC) with standard deviation (SD), and (2) explainability, illustrated by the visual examination of the estimated attention maps which showed the important areas for model diagnostics.
RESULTS: During the training and validation stage, we observe that when we provide no guidance from domain knowledge, the IPF diagnosis model reaches acceptable performance (AUC ± SD = 0.93 ± 0.07), but lacks explainability; when including only guided high- or medium- resolution attention, the learned attention maps are not satisfactory; when including both high- and medium- resolution attention, under certain hyperparameter settings, the model reaches the highest AUC among all experiments (AUC ± SD = 0.99 ± 0.01) and the estimated attention maps concentrate on the regions of interests for this task. Three best-performing hyperparameter selections according to MSGA were applied to the holdout test set and reached comparable model performance to that of the validation set.
CONCLUSIONS: Our results suggest that, for a task with only scan-level labels available, MSGA+RF can utilize the population-level domain knowledge to guide the training of the network, which increases both model accuracy and explainability. This article is protected by copyright. All rights reserved.
PMID:36254789 | DOI:10.1002/mp.16053
Coronavirus disease 2019 vaccination-induced acute exacerbation in idiopathic pulmonary fibrosis
Respirol Case Rep. 2022 Oct 12;10(11):e01051. doi: 10.1002/rcr2.1051. eCollection 2022 Nov.
ABSTRACT
We report a rare case of acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) after coronavirus disease 2019 (COVID-19) vaccination. Clinicians should be aware of this COVID-19 vaccination-induced AE in IPF.
PMID:36254333 | PMC:PMC9556549 | DOI:10.1002/rcr2.1051
Idiopathic Pulmonary Fibrosis: What do we Know about the Role of Occupational and Environmental Determinants? A Systematic Literature Review and Meta-Analysis
J Toxicol Environ Health B Crit Rev. 2022 Oct 17:1-21. doi: 10.1080/10937404.2022.2131663. Online ahead of print.
ABSTRACT
The objectives of this systematic review of original articles published up until August 2021 and meta-analyses were to identify the links between occupational and non-occupational environmental exposures, types of occupations and idiopathic pulmonary fibrosis (IPF). Sixteen selected case-control studies were qualified as good level with Newcastle-Ottawa quality assessment scale. Sensitivity analyses highlighted the role of choice of control group, tobacco adjustment and diagnostic tools. Significantly increased risks of IPF were observed (OR (95%CI): for metals (1.42(1.05-1.92)), wood (OR:1.32(1.02-1.71)), and general dust (OR:1.32(1.08-1.63)) exposures. Subgroup analyses found a significantly elevated risk for: hardwood (OR:1.75 (1.13-2.70)), organic dusts (OR:1.72 (1.20-2.46)) and pesticides (OR:2.30 (1.30-4.08)), while no significant change was noted for softwoods and solvents. Smoking adjustments: general dust (1.45 (1.04-2.03)/organic dust (2.5 (1.49-4.22)/metals (1.87 (1.16-3)/wood dust OR: 1.16 (0.86-1.61)/pesticide exposure 2.4 (0.84-6.9) were calculated. Among agricultural workers, the risk was also increased (OR:2.06 (1.02-4.16)). Few environmental data were available and no significant associations detected. Thus, these meta-analyses highlighted the role of some occupational exposures in IPF occurrence. A more accurate and thorough assessment of exposures over the entire working life as well as on the duration and intensity of exposure and complex of multi-pollutant exposure is needed in future research and clinical practice.
PMID:36253946 | DOI:10.1080/10937404.2022.2131663
Impact of body weight change on clinical outcomes in patients with idiopathic pulmonary fibrosis receiving pirfenidone
Sci Rep. 2022 Oct 17;12(1):17397. doi: 10.1038/s41598-022-22449-w.
ABSTRACT
There have been limited studies on the association between prognosis and body weight change in patients with idiopathic pulmonary fibrosis (IPF). This single-center retrospective observational study evaluated the impact of weight loss on outcomes in Korean patients with IPF receiving pirfenidone at a tertiary medical institution. We analyzed 215 IPF patients prescribed pirfenidone from January 1st, 2015 to December 31st, 2019. The patients were categorized into maintained weight (MW; weight gain or loss < 5%/year) and reduced weight (RW; weight loss ≥ 5%/year) groups. The mean age was 71.8 years and 175 (81.4%) were male. There were 54 (25.1%) patients in the RW group. All patients showed a decrease in body weight (baseline vs. after 1 year; 64.1 kg vs. 62.8 kg, P < 0.001). Although baseline lung function showed a difference, there was no difference in the rate of change (forced vital capacity [% of predicted]; P = 0.221, diffusing capacity of the lung for carbon monoxide [% of predicted]; P = 0.973). The MW group had a lower risk of all-cause mortality (P < 0.001). Weight loss appeared to be a significant risk factor for mortality in patients with IPF. Not only disease control with antifibrotic agents, but also efforts to prevent weight loss may be necessary.
PMID:36253395 | DOI:10.1038/s41598-022-22449-w
Imaging biomarkers of lung ventilation in interstitial lung disease from <sup>129</sup>Xe and oxygen enhanced <sup>1</sup>H MRI
Magn Reson Imaging. 2022 Oct 14:S0730-725X(22)00177-1. doi: 10.1016/j.mri.2022.10.005. Online ahead of print.
ABSTRACT
PURPOSE: To compare imaging biomarkers from hyperpolarised 129Xe ventilation MRI and dynamic oxygen-enhanced MRI (OE-MRI) with standard pulmonary function tests (PFT) in interstitial lung disease (ILD) patients. To evaluate if biomarkers can separate ILD subtypes and detect early signs of disease resolution or progression.
STUDY TYPE: Prospective longitudinal.
POPULATION: Forty-one ILD (fourteen idiopathic pulmonary fibrosis (IPF), eleven hypersensitivity pneumonitis (HP), eleven drug-induced ILD (DI-ILD), five connective tissue disease related-ILD (CTD-ILD)) patients and ten healthy volunteers imaged at visit 1. Thirty-four ILD patients completed visit 2 (eleven IPF, eight HP, ten DIILD, five CTD-ILD) after 6 or 26 weeks.
FIELD STRENGTH/SEQUENCE: MRI performed at 1.5 T. Inversion recovery T1 mapping, dynamic MRI acquisition with varying oxygen levels, and hyperpolarised 129Xe ventilation MRI. Subjects underwent standard spirometry and gas transfer testing.
ASSESSMENT: Five 1H MRI and two 129Xe MRI ventilation metrics were compared with spirometry and gas transfer measurements.
STATISTICAL TEST: To evaluate differences at visit 1 among subgroups: ANOVA or Kruskal-Wallis rank tests with correction for multiple comparisons. To assess the relationships between imaging biomarkers, PFT, age and gender, at visit 1 and for the change between visit 1 and 2: Pearson correlations and multilinear regression models.
RESULTS: The global PFT tests could not distinguish ILD subtypes. Ventilated volumes were lower in ILD patients than in HVs when measured with 129Xe MRI (HV 97.4 ± 2.6, CTD-ILD: 91.0 ± 4.8 p = 0.017, DI-ILD 90.1 ± 7.4 p = 0.003, HP 92.6 ± 4.0 p = 0.013, IPF 88.1 ± 6.5 p < 0.001), but not with OE-MRI. 129Xe reported more heterogeneous ventilation in DI-ILD and IPF than in HV, and OE-MRI reported more heterogeneous ventilation in DI-ILD and IPF than in HP or CTD-ILD. The longitudinal changes reported by the imaging biomarkers did not correlate with the PFT changes between visits.
DATA CONCLUSION: Neither 129Xe ventilation nor OE-MRI biomarkers investigated in this study were able to differentiate between ILD subtypes, suggesting that ventilation-only biomarkers are not indicated for this task. Limited but progressive loss of ventilated volume as measured by 129Xe-MRI may be present as the biomarker of focal disease progresses. OE-MRI biomarkers are feasible in ILD patients and do not correlate strongly with PFT. Both OE-MRI and 129Xe MRI revealed more spatially heterogeneous ventilation in DI-ILD and IPF.
PMID:36252693 | DOI:10.1016/j.mri.2022.10.005
Zanubrutinib attenuates bleomycin-induced pulmonary fibrosis by inhibiting the TGF-β1 signaling pathway
Int Immunopharmacol. 2022 Oct 14;113(Pt A):109316. doi: 10.1016/j.intimp.2022.109316. Online ahead of print.
ABSTRACT
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal interstitial lung disease with high mortality and limited treatment. Only two drugs are currently approved for the treatment of IPF, but both have limitations and neither drug could prolong survival time of patients. The etiology of IPF is unclear, but there is growing evidence that B cells and B cell receptor signaling play important roles in the pathogenesis of IPF. Zanubrutinib is a small molecule inhibitor of Bruton's tyrosine kinase (BTK), which is a key enzyme downstream of B cell receptor signaling pathway, has approved for the treatment of mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). While its role in pulmonary fibrosis remains unknown. In this study, we explored the potential effect and mechanisms of zanubrutinib on pulmonary fibrosis in vivo and in vitro.
METHODS: In the in vivo experiments, different doses of zanubrutinib were administered in a mouse model of bleomycin-induced pulmonary fibrosis, and pathological manifestations and lung function indices were evaluated. In vitro experiments were performed using TGF-β1-stimulated fibroblasts to evaluate the effect of zanubrutinib on the activation and autophagy phenotype of fibroblasts and to explore the underlying signaling pathway mechanism.
RESULTS: In vivo experiments demonstrated that zanubrutinib effectively attenuated bleomycin (BLM)-induced pulmonary fibrosis in mice. An in vitro mechanistic study indicated that zanubrutinib suppresses collagen deposition and myofibroblast activation by inhibiting the TGF-β1/Smad pathway and induces autophagy through the TGF-β1/mTOR pathway.
CONCLUSIONS: Zanubrutinib alleviated bleomycin-induced lung fibrosis in mice by inhibiting the TGF-β1 signaling pathway.
PMID:36252483 | DOI:10.1016/j.intimp.2022.109316
Acute exacerbation in antineutrophil cytoplasmic antibody-associated interstitial lung disease: Clinical features and risk factors
Respir Med. 2022 Sep 24;203:106992. doi: 10.1016/j.rmed.2022.106992. Online ahead of print.
ABSTRACT
BACKGROUND: Acute exacerbation (AE) is a life-threatening clinical event that occurs during the clinical course of idiopathic pulmonary fibrosis (IPF). Several studies have reported that AE also occurs in interstitial lung disease (ILD) other than IPF. However, the incidence, clinical features, risk factors for AE, and major causes of death in antineutrophil cytoplasmic antibody (ANCA)-associated ILD (ANCA-ILD) patients have not been well established.
METHODS: We retrospectively reviewed the data of 54 ANCA-ILD patients and 304 IPF patients. We investigated the frequency of AE, post-AE prognoses, risk factors for AE, and major causes of death in ANCA-ILD patients. We also compared the data of ANCA-ILD with that of IPF.
RESULTS: Fourteen (25.9%) ANCA-ILD patients and 84 (27.6%) IPF patients developed AE. The median survival times (MSTs) after AE in ANCA-ILD and IPF patients were 35.5 and 60 days, respectively (p = 0.588, log-rank test). In a multivariate analysis, the percentage of predicted forced vital capacity (%FVC) [O.R. 0.750 (95% CI 0.570, 0.986), p < 0.01] and serum C-reactive protein (CRP) [O.R. 2.202 (95% CI 1.037, 4.674), p < 0.01] were independent risk factors for AE. AE was the most frequent cause of death in ANCA-ILD and IPF patients.
CONCLUSION: ANCA-ILD patients could develop AE, and the frequency of AE in ANCA-ILD is similar to that in IPF. AE is the most frequent cause of death in ANCA-ILD patients. A low %FVC and a high serum CRP level were independent predictive factors for AE in ANCA-ILD. The prognosis after AE in ANCA-ILD was poor, as it was in IPF.
PMID:36252462 | DOI:10.1016/j.rmed.2022.106992
Identification of suitable reference genes for normalization of reverse transcription quantitative real-time PCR (RT-qPCR) in the fibrotic phase of the bleomycin mouse model of pulmonary fibrosis
PLoS One. 2022 Oct 17;17(10):e0276215. doi: 10.1371/journal.pone.0276215. eCollection 2022.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a severe lung disease with a poor prognosis and few treatment options. In the most widely used experimental model for this disease, bleomycin is administered into the lungs of mice, causing a reaction of inflammation and consequent fibrosis that resembles the progression of human IPF. The inflammation and fibrosis together induce changes in gene expression that can be analyzed with reverse transcription quantitative real-time PCR (RT-qPCR), in which accurate normalization with a set of stably expressed reference genes is critical for obtaining reliable results. This work compares ten commonly used candidate reference genes in the late, fibrotic phase of bleomycin-induced pulmonary fibrosis and ranks them from the most to the least stable using NormFinder and geNorm. Sdha, Polr2a and Hprt were identified as the best performing and least variable reference genes when alternating between normal and fibrotic conditions. In order to validate the findings, we investigated the expression of Tnf and Col1a1, representing the hallmarks of inflammation and fibrotic changes, respectively. With the best three genes as references, both were found to be upregulated relative to untreated controls, unlike the situation when analyzed solely with Gapdh, a commonly used reference gene. We therefore recommend Sdha, Polr2a and Hprt as reference genes for RT-qPCR in the 4-week bleomycin challenge that represents the late fibrotic phase.
PMID:36251700 | DOI:10.1371/journal.pone.0276215
Association of Particulate Matter Exposure With Lung Function and Mortality Among Patients With Fibrotic Interstitial Lung Disease
JAMA Intern Med. 2022 Oct 17. doi: 10.1001/jamainternmed.2022.4696. Online ahead of print.
ABSTRACT
IMPORTANCE: Particulate matter 2.5 μm or less in diameter (PM2.5) is associated with adverse outcomes for patients with idiopathic pulmonary fibrosis, but its association with other fibrotic interstitial lung diseases (fILDs) and the association of PM2.5 composition with adverse outcomes remain unclear.
OBJECTIVE: To investigate the association of PM2.5 exposure with mortality and lung function among patients with fILD.
DESIGN, SETTING, AND PARTICIPANTS: In this multicenter, international, prospective cohort study, patients were enrolled in the Simmons Center for Interstitial Lung Disease Registry at the University of Pittsburgh in Pittsburgh, Pennsylvania; 42 sites of the Pulmonary Fibrosis Foundation Registry; and 8 sites of the Canadian Registry for Pulmonary Fibrosis. A total of 6683 patients with fILD were included (Simmons, 1424; Pulmonary Fibrosis Foundation, 1870; and Canadian Registry for Pulmonary Fibrosis, 3389). Data were analyzed from June 1, 2021, to August 2, 2022.
EXPOSURES: Exposure to PM2.5 and its constituents was estimated with hybrid models, combining satellite-derived aerosol optical depth with chemical transport models and ground-based PM2.5 measurements.
MAIN OUTCOMES AND MEASURES: Multivariable linear regression was used to test associations of exposures 5 years before enrollment with baseline forced vital capacity and diffusion capacity for carbon monoxide. Multivariable Cox models were used to test associations of exposure in the 5 years before censoring with mortality, and linear mixed models were used to test associations of exposure with a decrease in lung function. Multiconstituent analyses were performed with quantile-based g-computation. Cohort effect estimates were meta-analyzed. Models were adjusted for age, sex, smoking history, race, a socioeconomic variable, and site (only for Pulmonary Fibrosis Foundation and Canadian Registry for Pulmonary Fibrosis cohorts).
RESULTS: Median follow-up across the 3 cohorts was 2.9 years (IQR, 1.5-4.5 years), with death for 28% of patients and lung transplant for 10% of patients. Of the 6683 patients in the cohort, 3653 were men (55%), 205 were Black (3.1%), and 5609 were White (84.0%). Median (IQR) age at enrollment across all cohorts was 66 (58-73) years. A PM2.5 exposure of 8 μg/m3 or more was associated with a hazard ratio for mortality of 4.40 (95% CI, 3.51-5.51) in the Simmons cohort, 1.71 (95% CI, 1.32-2.21) in the Pulmonary Fibrosis Foundation cohort, and 1.45 (95% CI, 1.18-1.79) in the Canadian Registry for Pulmonary Fibrosis cohort. Increasing exposure to sulfate, nitrate, and ammonium PM2.5 constituents was associated with increased mortality across all cohorts, and multiconstituent models demonstrated that these constituents tended to be associated with the most adverse outcomes with regard to mortality and baseline lung function. Meta-analyses revealed consistent associations of exposure to sulfate and ammonium with mortality and with the rate of decrease in forced vital capacity and diffusion capacity of carbon monoxide and an association of increasing levels of PM2.5 multiconstituent mixture with all outcomes.
CONCLUSIONS AND RELEVANCE: This cohort study found that exposure to PM2.5 was associated with baseline severity, disease progression, and mortality among patients with fILD and that sulfate, ammonium, and nitrate constituents were associated with the most harm, highlighting the need for reductions in human-derived sources of pollution.
PMID:36251286 | DOI:10.1001/jamainternmed.2022.4696
Detection of interstitial pneumonia with autoimmune features and idiopathic pulmonary fibrosis are enhanced by involvement of matrix metalloproteinases levels and clinical diagnosis
J Clin Lab Anal. 2022 Oct 17:e24734. doi: 10.1002/jcla.24734. Online ahead of print.
ABSTRACT
BACKGROUND: Higher detection of interstitial pneumonia with autoimmune features (IPAF), and idiopathic pulmonary fibrosis (IPF), has significant diagnostic and therapeutic implications. Some matrix metalloproteinases (MMPs) have become reliable diagnostic biomarkers in IPAF and IPF in previous studies, yet relevant reliability remains to be recognized.
MATERIALS AND METHODS: In this study, 36 ILDs patients, including 31 IPAF patients (Mean ± SD, 50.20 ± 5.10 years; 16 [51.6%] females) and five IPF patients (Mean ± SD, 61.20 ± 6.73 years; one [20.0%] females) were retrospectively enrolled. Serial serum samples were collected from patients with IPAF and IPF between January 2019 and December 2020. Notably, Serum MMPs levels were measured by U-PLEX Biomarker Group 1(Human) Multiplex Assays (MSD, USA).
RESULTS: A combination of MMPs and combinatorial biomarkers was strongly associated with clinical subjects in this study (AUC, 0.597 for Stability vs. Improvement and 0.756 for Stability vs. Exacerbation). Importantly, the AUC of MMP-12 reaches 0.730 (p < 0.05, Stability AUC vs. Improvement AUC) while MMP-13 reaches 0.741 (p < 0.05, Stability AUC vs. Exacerbation AUC) showed better performance than other MMPs in two comparisons.
CONCLUSIONS: Clinical risk factors and MMPs are strongly associated with either stratification of the disease of progression of IPAF or in two IPAF and IPF independent cohorts. To our knowledge, this is the first to illustrate that MMP-12 and MMP-13 may be expected to become typical promising biomarkers in Improvement - IPAF and Exacerbation - IPAF, respectively.
PMID:36250225 | DOI:10.1002/jcla.24734
Single cell meta-analysis of EndMT and EMT state in COVID-19
Front Immunol. 2022 Sep 29;13:976512. doi: 10.3389/fimmu.2022.976512. eCollection 2022.
ABSTRACT
COVID-19 prognoses suggests that a proportion of patients develop fibrosis, but there is no evidence to indicate whether patients have progression of mesenchymal transition (MT) in the lungs. The role of MT during the COVID-19 pandemic remains poorly understood. Using single-cell RNA sequencing, we profiled the transcriptomes of cells from the lungs of healthy individuals (n = 45), COVID-19 patients (n = 58), and idiopathic pulmonary fibrosis (IPF) patients (n = 64) human lungs to map the entire MT change. This analysis enabled us to map all high-resolution matrix-producing cells and identify distinct subpopulations of endothelial cells (ECs) and epithelial cells as the primary cellular sources of MT clusters during COVID-19. For the first time, we have identied early and late subgroups of endothelial mesenchymal transition (EndMT) and epithelial-mesenchymal transition (EMT) using analysis of public databases for single-cell sequencing. We assessed epithelial subgroups by age, smoking status, and gender, and the data suggest that the proportional changes in EMT in COVID-19 are statistically significant. Further enumeration of early and late EMT suggests a correlation between invasive genes and COVID-19. Finally, EndMT is upregulated in COVID-19 patients and enriched for more inflammatory cytokines. Further, by classifying EndMT as early or late stages, we found that early EndMT was positively correlated with entry factors but this was not true for late EndMT. Exploring the MT state of may help to mitigate the fibrosis impact of SARS-CoV-2 infection.
PMID:36248845 | PMC:PMC9558222 | DOI:10.3389/fimmu.2022.976512
Inhibition of MAD2L1 Mediates Pulmonary Fibrosis through Impairment of Mitochondrial Function and Induction of Cell Senescence
Can Respir J. 2022 Oct 4;2022:9663354. doi: 10.1155/2022/9663354. eCollection 2022.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a chronic, irreversible, and progressive interstitial lung disease characterized by recurrent alveolar epithelial cell injury, fibroblast hyperproliferation, and cumulative deposition of extracellular matrix leading to alveolar destruction in the lungs. Mitotic arrest deficient 2 like 1 (MAD2L1) is a component of the mitotic spindle assembly checkpoint that prevents the onset of anaphase until all chromosomes are properly aligned at metaphase and is a potential therapeutic target in cancers. However, the role of MAD2L1 in pulmonary fibrosis has not been explored. We analyzed the expression of MAD2L1 in lung tissues from control subjects, IPF patients, and mice with bleomycin-induced fibrosis via IHC, qRT-PCR, and Western blot analysis. We examined the roles of MAD2L1 in ROS production, mitochondrial function, cell senescence, and the establishment of a profibrotic microenvironment. We found that MAD2L1 was highly upregulated in alveolar epithelial cells in fibrotic lung tissues from both patients with IPF and mice with bleomycin-induced fibrosis. Loss of MAD2L1 expression or activity led to decreases of cell viability and proliferation in A549 cells. Subsequent mechanistic investigation demonstrated that inhibition of MAD2L1 damaged mitochondria, which led to augmented ROS production and cellular senescence, and thus promoted the establishment of a profibrotic microenvironment. Taken together, these results reveal that alleviation of alveolar epithelial cell mitochondrial damage arising from augmentation of MAD2L1 may be a novel therapeutic strategy for mitigating pulmonary fibrosis.
PMID:36247080 | PMC:PMC9553670 | DOI:10.1155/2022/9663354
Lysophosphatidic acid, ceramide 1-phosphate and sphingosine 1-phosphate in peripheral blood of patients with idiopathic pulmonary fibrosis
J Med Invest. 2022;69(3.4):196-203. doi: 10.2152/jmi.69.196.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonias. Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are signaling lipids that evoke growth factor-like responses to many cells. Recent studies revealed the involvement of LPA and S1P in the pathology of IPF. In this study, we determined LPA, S1P and ceramide 1-phosphate (C1P) in peripheral blood plasma of IPF patients, and examined correlation to the vital capacity of lung (VC), an indicator of development of fibrosis. Blood plasma samples were taken from eleven patients with IPF and seven healthy volunteers. The lipids of the sample were extracted and subjected to liquid chromatography-tandem mass spectrometry for analysis. Results showed that there is a significant negative correlation between VC and plasma LPA levels, indicating that IPF patients with advanced fibrosis had higher concentration of LPA in their plasma. Average of S1P levels were significantly higher in IPF patients than those in healthy subjects. Although it is not statistically significant, a similar correlation trend that observed in LPA levels also found between VC and S1P levels. These results indicated that plasma LPA and S1P may be associated with deterioration of pulmonary function of IPF patients. J. Med. Invest. 69 : 196-203, August, 2022.
PMID:36244770 | DOI:10.2152/jmi.69.196
Developing PI3K Inhibitors for Respiratory Diseases
Curr Top Microbiol Immunol. 2022;436:437-466. doi: 10.1007/978-3-031-06566-8_19.
ABSTRACT
A number of different experimental models using both non-selective and selective PI3K inhibitors have shown that many pathogenic steps of respiratory disorders, such as bronchial asthma, Chronic Obstructive Pulmonary Disease (COPD), Idiopathic Pulmonary Fibrosis (IPF), Acute Respiratory Distress Syndrome (ARDS) and Lung Cancer (LC) are, at least in part, regulated by the PI3K signaling pathway, suggesting that the inhibition of PI3K could represent an ideal therapeutic target for the treatment of respiratory diseases. This chapter summarizes the current state of the therapeutic strategies aimed to exploit the inhibition of PI3K in this context. In animal models of asthma, selective δ and γ inhibitors have shown to be effective, and when administered by inhalation, reasonably safe. Nevertheless, very few clinical trials have been performed so far. The efficacy of current traditional therapies for allergic bronchial asthma has likely diminished the need for new alternative treatments. Surprisingly, in COPD, where instead there is an urgent need for new and more effective therapeutic approaches, the number of clinical studies is still low and not capable yet, with the exception for an acceptable safety profile, to show a significant improvement of clinical outcomes. In IPF, a disease with a disappointing prognosis, PI3K inhibitors have been bound to a FAP ligand with the aim to selectively target myofibroblasts, showing to significantly reduce collagen production and the development of lung fibrosis in an animal model of lung fibrosis. Due to its role in cell activation and cell replication, the PI3K pathway is obviously largely involved in lung cancer. Several studies, currently ongoing, are testing the effect of PI3K inhibitors mainly in NSCLC. Some evidence in the treatment of cancer patients suggests the possibility that PI3K inhibitors may enhance the response to conventional treatment. The involvement of PI3Kδ in the modulation of airway neutrophil recruitment and bronchial epithelial functional alterations also suggest a potential role in the treatment of ARDS, but at the current state the ongoing trials are aimed to the treatment of ARDS in COVID-19 patients. In general, few clinical trials investigating PI3K inhibitors in respiratory disorders have been performed so far. This relatively new approach of treatment is just at its beginning and certainly needs further efforts and additional studies.
PMID:36243856 | DOI:10.1007/978-3-031-06566-8_19
The Novel Small Molecule BTB Inhibits Pro-Fibrotic Fibroblast Behavior though Inhibition of RhoA Activity
Int J Mol Sci. 2022 Oct 8;23(19):11946. doi: 10.3390/ijms231911946.
ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, interstitial lung disease with a poor prognosis. Although specific anti-fibrotic medications are now available, the median survival time following diagnosis remains very low, and new therapies are urgently needed. To uncover novel therapeutic targets, we examined how biochemical properties of the fibrotic lung are different from the healthy lung. Previous work identified lactate as a metabolite that is upregulated in IPF lung tissue. Importantly, inhibition of the enzyme responsible for lactate production prevents fibrosis in vivo. Further studies revealed that fibrotic lesions of the lung experience a significant decline in tissue pH, likely due to the overproduction of lactate. It is not entirely clear how cells in the lung respond to changes in extracellular pH, but a family of proton sensing G-protein coupled receptors has been shown to be activated by reductions in extracellular pH. This work examines the expression profiles of proton sensing GPCRs in non-fibrotic and IPF-derived primary human lung fibroblasts. We identify TDAG8 as a proton sensing GPCR that is upregulated in IPF fibroblasts and that knockdown of TDAG8 dampens myofibroblast differentiation. To our surprise, BTB, a proposed positive allosteric modulator of TDAG8, inhibits myofibroblast differentiation. Our data suggest that BTB does not require TDAG8 to inhibit myofibroblast differentiation, but rather inhibits myofibroblast differentiation through suppression of RhoA mediated signaling. Our work highlights the therapeutic potential of BTB as an anti-fibrotic treatment and expands upon the importance of RhoA-mediated signaling pathways in the context of myofibroblast differentiation. Furthermore, this works also suggests that TDAG8 inhibition may have therapeutic relevance in the treatment of IPF.
PMID:36233248 | DOI:10.3390/ijms231911946