Curr Opin Pulm Med. 2021 Jul 6. doi: 10.1097/MCP.0000000000000803. Online ahead of print.

ABSTRACT

PURPOSE OF REVIEW: Describe the concept and recent data for the concept of progressive fibrotic interstitial lung disease (ILD).

RECENT FINDINGS: Making an accurate diagnosis is critical to help determine appropriate therapy and predict prognosis. This is certainly true in the field of ILD where a diagnosis of idiopathic pulmonary fibrosis (IPF) leads a clinician to consider initiation of antifibrotic therapy, and avoidance of immunosuppression due to possible harm, at the time of diagnosis due to the high probability of disease progression. In other types of ILD immunosuppression may be helpful such as those associated with a connective tissue disease or in combination with antigen avoidance in hypersensitivity pneumonia. It is also recognized that despite initial approaches to therapy some non-IPF ILDs will develop progressive fibrosis leading to increased symptoms, decreased quality of life and early mortality. Once fibrosis is present, the biologic pathways responsible for progression can be redundant and respond in a similar fashion to antifibrotic therapy independent of the underlying disease.

SUMMARY: There are clinical and biological rationale for the justification of a progressive fibrotic phenotype that complements the therapeutic decisions and prognosis provided by initial diagnosis.

PMID:34231534 | DOI:10.1097/MCP.0000000000000803

J Cell Physiol. 2021 Jul 6. doi: 10.1002/jcp.30500. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia. It is unknown why fibrosis in IPF distributes in the peripheral or named sub-pleural area. Migration of pleural mesothelial cells (PMC) should contribute to sub-pleural fibrosis. Calpain is known to be involved in cell migration, but the role of calpain in PMC migration has not been investigated. In this study, we found that PMCs migrated into lung parenchyma in patients with IPF. Then using Wt1tm1(EGFP/Cre)Wtp /J knock-in mice, we observed PMC migration into lung parenchyma in bleomycin-induced pleural fibrosis models, and calpain inhibitor attenuated pulmonary fibrosis with prevention of PMC migration. In vitro studies revealed that bleomycin and transforming growth factor-β1 increased calpain activity in PMCs, and activated calpain-mediated focal adhesion (FA) turnover as well as cell migration, cell proliferation, and collagen-I synthesis. Furthermore, we determined that calpain cleaved FA kinase in both C-terminal and N-terminal regions, which mediated FA turnover. Lastly, the data revealed that activated calpain was also involved in phosphorylation of cofilin-1, and p-cofilin-1 induced PMC migration. Taken together, this study provides evidence that calpain mediates PMC migration into lung parenchyma to promote sub-pleural fibrosis in IPF.

PMID:34231213 | DOI:10.1002/jcp.30500

Glycobiology. 2021 Jul 6:cwab072. doi: 10.1093/glycob/cwab072. Online ahead of print.

ABSTRACT

Galectin-3 (Gal-3), a β-galactoside binding lectin, has been implicated in a plethora of pathological disorders including fibrosis, inflammation, cancer, and metabolic diseases. TD139 - a thio-digalactoside inhibitor developed by Galecto Biotech as a potential therapeutic for idiopathic pulmonary fibrosis, is the most advanced small-molecule galectin-3 inhibitor in clinical studies. It binds to human Gal-3 with high affinity but has lower affinity towards mouse and rat homologs, which is also manifested in the differential inhibition of Gal-3 function. Using biophysical methods and high resolution X-ray co-crystal structures of TD139 and Gal-3 proteins, we demonstrate that a single amino acid change corresponding to A146 in human Gal-3 is sufficient for the observed reduction in the binding affinity of TD139 in rodents. Site-directed mutagenesis of A146V (in human Gal-3) & V160A (in mouse Gal-3) was sufficient to interchange the affinities, mainly by affecting the off rates of the inhibitor binding. Additionally, molecular dynamics simulations of both wild type and mutant structures revealed the sustained favorable non-covalent interactions between the fluorophenyl ring and the active site A146 (human Gal-3 and mouse V160A) that corroborate the finding from biophysical studies. Current findings have ramifications in the context of optimization of drug candidates against Gal-3.

PMID:34228782 | DOI:10.1093/glycob/cwab072

Thorax. 2021 Jul 5:thoraxjnl-2021-217377. doi: 10.1136/thoraxjnl-2021-217377. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterised by exuberant tissue remodelling and associated with high unmet medical needs. Outcomes are even worse when IPF results in secondary pulmonary hypertension (PH). Importantly, exaggerated resistance to cell death, excessive proliferation and enhanced synthetic capacity are key endophenotypes of both fibroblasts and pulmonary artery smooth muscle cells, suggesting shared molecular pathways. Under persistent injury, sustained activation of the DNA damage response (DDR) is integral to the preservation of cells survival and their capacity to proliferate. Checkpoint kinases 1 and 2 (CHK1/2) are key components of the DDR. The objective of this study was to assess the role of CHK1/2 in the development and progression of IPF and IPF+PH.

METHODS AND RESULTS: Increased expression of DNA damage markers and CHK1/2 were observed in lungs, remodelled pulmonary arteries and isolated fibroblasts from IPF patients and animal models. Blockade of CHK1/2 expression or activity-induced DNA damage overload and reverted the apoptosis-resistant and fibroproliferative phenotype of disease cells. Moreover, inhibition of CHK1/2 was sufficient to interfere with transforming growth factor beta 1-mediated fibroblast activation. Importantly, pharmacological inhibition of CHK1/2 using LY2606368 attenuated fibrosis and pulmonary vascular remodelling leading to improvement in respiratory mechanics and haemodynamic parameters in two animal models mimicking IPF and IPF+PH.

CONCLUSION: This study identifies CHK1/2 as key regulators of lung fibrosis and provides a proof of principle for CHK1/2 inhibition as a potential novel therapeutic option for IPF and IPF+PH.

PMID:34226205 | DOI:10.1136/thoraxjnl-2021-217377

Drug Deliv. 2021 Dec;28(1):1419-1431. doi: 10.1080/10717544.2021.1921073.

ABSTRACT

Glucocorticoid (GC) hormone has been commonly used to treat systemic inflammation and immune disorders. However, the side effects associated with long-term use of high-dose GC hormone limit its clinical application seriously. GC hormone that can specifically target the lung might decrease the effective dosage and thus reduce GC-associated side effects. In this study, we successfully prepared human lung-targeting liposomal methylprednisolone crosslinked with nanobody (MPS-NSSLs-SPANb). Our findings indicate that MPS-NSSLs-SPANb may reduce the effective therapeutic dosage of MPS, achieve better efficacy, and reduce GC-associated side effects. In addition, MPS-NSSLs-SPANb showed higher efficacy and lower toxicity than conventional MPS.

PMID:34223777 | DOI:10.1080/10717544.2021.1921073

Front Mol Biosci. 2021 Jun 16;8:681669. doi: 10.3389/fmolb.2021.681669. eCollection 2021.

ABSTRACT

The application of transbronchial lung cryobiopsy (TBLC) and uniportal and tubeless video-assisted thoracic surgery (UT-VATS) in the multidisciplinary diagnosis of interstitial lung disease (ILD) has not been demonstrated in real-world clinical practice. This prospective study included 137 patients with no definitive diagnosis who were the subject of two multidisciplinary discussion (MDD) sessions. As indicated in the first MDD, 67 patients underwent UT-VATS and 70 underwent TBLC. The specificity of biopsy information and its contribution to final MDD diagnosis were evaluated in the second MDD. The post-operative complications and hospitalization costs associated with the two biopsy methods were compared. UT-VATS was favored for patients initially diagnosed with idiopathic pulmonary fibrosis (IPF), bronchiolitis-associated interstitial lung disease (RB-ILD)/desquamative interstitial pneumonia (DIP) and undefined idiopathic interstitial pneumonia (UIIP), while TBLC was preferred for pulmonary lymphangioleiomyomatosis (PLAM) and pulmonary alveolar proteinosis (PAP). The spirometry parameters were better in patients who underwent UT-VATS than those who underwent TBLC. UT-VATS provided more specific pathological results than TBLC (85.7 vs 73.7%, p = 0.06). In patients initially diagnosed with UIIP, pathological information from UT-VATS was more clinically useful than that obtained from TBLC, although both tests contributed similarly to cases initially diagnosed as interstitial pneumonia with auto-immune features (IPAF)/connective tissue disease-related ILD (CTD-ILD). The safety of UT-VATS was comparable with TBLC although TBLC was cheaper during hospitalization (US$4,855.7 vs US$3,590.9, p < 0.001). multidisciplinary discussion decisions about biopsies were driven by current knowledge of sampling and diagnosis capacity as well as potential risks of different biopsy methods. The current MDD considered UT-VATS more informative than TBLC in cases initially diagnosed as UIIP although they were equally valuable in patients initially diagnosed with IPAF/CTD-ILD.

PMID:34222336 | PMC:PMC8241905 | DOI:10.3389/fmolb.2021.681669

Front Med (Lausanne). 2021 Jun 17;8:679487. doi: 10.3389/fmed.2021.679487. eCollection 2021.

ABSTRACT

Background: Comorbidities in idiopathic pulmonary fibrosis (IPF) affect quality of life, symptoms, disease progression and survival. It is unknown what are the comorbidities in patients with IPF in Latin America (LA) and if there are differences between countries. Our objective was to compare IPF comorbidities in four countries and analyze possible differences by altitude. Methods: Patients with IPF according 2012 ATS/ERS/JRS/ALAT guidelines, from two cities with an altitude of ≥2,250 m: Mexico City (Mexico) and Bogotá (Colombia) and from three at sea level: Buenos Aires (Argentina) and Lima and Trujillo (Peru). Comorbidities and pulmonary function tests were taken from clinical records. Possible pulmonary hypertension (PH) was defined by findings in the transthoracic echocardiogram of systolic pulmonary arterial pressure (sPAP) >36 mmHg or indirect signs of PH in the absence of other causes of PH. Emphysema as the concomitant finding of IPF criteria on chest tomography plus emphysema in the upper lobes. ANOVA or Kruskal Wallis and χ2-tests were used for comparison. Results: Two hundred and seventy-six patients were included, 50 from Argentina, 86 from Colombia, 91 from Mexico and 49 from Peru. There prevalence of PH was higher in Colombia and Mexico (p < 0.001), systemic arterial hypertension in Argentina (p < 0.015), gastro-esophageal reflux and dyslipidemia in Colombia and Argentina (p < 0.001) and diabetes mellitus in Mexico (p < 0.007). Other comorbidities were obesity (28.4%), coronary artery disease (15.2%) and emphysema (14.9%), with no differences between countries. There was more PH in the altitude cities than those at sea level (51.7 vs. 15.3%, p < 0.001). In patients from Bogotá and Mexico City, arterial oxygen pressure, saturation (p < 0.001) and carbon monoxide diffusing capacity (p = 0.004) were significantly lower than in cities at sea level. Conclusions: In this study with a significant number of patients, we were able to describe and compare the comorbidities of IPF in four LA countries, which contributes to the epidemiological data of this disease in the region. The main results were the differences in comorbidities between the countries and more PH in the subjects residing in the cities of higher altitude, a finding that should be validated in future studies.

PMID:34222287 | PMC:PMC8245671 | DOI:10.3389/fmed.2021.679487

Acta Pharm Sin B. 2021 Jun;11(6):1412-1433. doi: 10.1016/j.apsb.2020.12.003. Epub 2020 Dec 9.

ABSTRACT

Anoctamin 1 (ANO1) or TMEM16A gene encodes a member of Ca2+ activated Cl- channels (CaCCs) that are critical for physiological functions, such as epithelial secretion, smooth muscle contraction and sensory signal transduction. The attraction and interest in ANO1/TMEM16A arise from a decade long investigations that abnormal expression or dysfunction of ANO1 is involved in many pathological phenotypes and diseases, including asthma, neuropathic pain, hypertension and cancer. However, the lack of specific modulators of ANO1 has impeded the efforts to validate ANO1 as a therapeutic target. This review focuses on the recent progress made in understanding of the pathophysiological functions of CaCC ANO1 and the current modulators used as pharmacological tools, hopefully illustrating a broad spectrum of ANO1 channelopathy and a path forward for this target validation.

PMID:34221860 | PMC:PMC8245819 | DOI:10.1016/j.apsb.2020.12.003

Front Immunol. 2021 Jun 15;12:661811. doi: 10.3389/fimmu.2021.661811. eCollection 2021.

ABSTRACT

Fibrotic Interstitial lung diseases (ILDs) are complex disorders of variable clinical behaviour. The majority of them cause significant morbidity, whilst Idiopathic Pulmonary Fibrosis (IPF) is recognised as the most relentless. NLRP3, AIM2, and NLRC4 inflammasomes are multiprotein complexes driving IL-1β release; a proinflammatory and profibrotic cytokine. Several pathogenetic factors associated with IPF are identified as inflammasome activators, including increases in mtROS and bacterial burden. Mitochondrial oxidation and alterations in bacterial burden in IPF and other ILDs may lead to augmented inflammasome activity in airway macrophages (AMs). IPF (n=14), non-IPF-ILDs (n=12) patients and healthy subjects (n=12) were prospectively recruited and AMs were isolated from bronchoalveolar lavage. IL-1β release resulting from NLRP3, AIM2 and NLRC4 inflammasomes stimulation in AMs were determined and baseline levels of mitochondrial ROS and microbial burden were also measured. Our results showed that NLRP3 was more inducible in IPF and other ILDs compared to controls. Additionally, following AIM2 activation IL-1β release was significantly higher in IPF compared to controls, whereas similar trends were observed in Non-IPF-ILDs. NLRC4 activation was similar across groups. mtROS was significantly associated with heightened NLRP3 and AIM2 activation, and mitochondrial antioxidant treatment limited inflammasome activation. Importantly, microbial burden was linked to baseline IL-1β release and AIM2 and IL-18 relative expression independently of mtROS. In conclusion, the above findings suggested a link between the overactivation of NLRP3 and AIM2 inflammasomes, driven by mitochondrial oxidation, in the pathogenesis of lung fibrosis while changes in the microbiota may prime the inflammasome in the lungs.

PMID:34220810 | PMC:PMC8248801 | DOI:10.3389/fimmu.2021.661811

Acad Radiol. 2021 Jul 1:S1076-6332(21)00253-1. doi: 10.1016/j.acra.2021.05.014. Online ahead of print.

ABSTRACT

RATIONALE AND OBJECTIVES: High-resolution computed tomography (HRCT) is paramount in the assessment of interstitial lung disease (ILD). Yet, HRCT interpretation of ILDs may be hampered by inter- and intra-observer variability. Recently, artificial intelligence (AI) has revolutionized medical image analysis. This technology has the potential to advance patient care in ILD. We aimed to systematically evaluate the application of AI for the analysis of ILD in HRCT.

MATERIALS AND METHODS: We searched MEDLINE/PubMed databases for original publications of deep learning for ILD analysis on chest CT. The search included studies published up to March 1, 2021. The risk of bias evaluation included tailored Quality Assessment of Diagnostic Accuracy Studies and the modified Joanna Briggs Institute Critical Appraisal checklist.

RESULTS: Data was extracted from 19 retrospective studies. Deep learning techniques included detection, segmentation, and classification of ILD on HRCT. Most studies focused on the classification of ILD into different morphological patterns. Accuracies of 78%-91% were achieved. Two studies demonstrated near-expert performance for the diagnosis of idiopathic pulmonary fibrosis (IPF). The Quality Assessment of Diagnostic Accuracy Studies tool identified a high risk of bias in 15/19 (78.9%) of the studies.

CONCLUSION: AI has the potential to contribute to the radiologic diagnosis and classification of ILD. However, the accuracy performance is still not satisfactory, and research is limited by a small number of retrospective studies. Hence, the existing published data may not be sufficiently reliable. Only well-designed prospective controlled studies can accurately assess the value of existing AI tools for ILD evaluation.

PMID:34219012 | DOI:10.1016/j.acra.2021.05.014

Chest. 2021 Jul 1:S0012-3692(21)01279-4. doi: 10.1016/j.chest.2021.06.049. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease associated with significant morbidity and mortality. Nintedanib and pirfenidone are two antifibrotic medications currently approved for slowing the rate of lung function decline in IPF, but information on treatment effect on mortality and risk of acute exacerbation (AE) remains limited or unknown.

RESEARCH QUESTION: Does antifibrotic treatment decrease risk of mortality and AE?

STUDY DESIGN AND METHODS: A comprehensive search of several databases, including Ovid MEDLINE(R), Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus, was conducted. Studies were included if they were original articles comparing mortality or AE events in IPF patients with and without antifibrotic treatment. Relative risk (RR) with 95% confident interval (CI) was pooled using random-effects meta-analyses with inverse variance method, assessing two primary outcomes of all-cause mortality and acute exacerbation (AE) risk.

RESULTS: A total of 12,956 patients across 26 studies (8 randomized controlled trials and 18 cohort studies) were included in the meta-analysis. Antifibrotic treatment was associated with decreased risk of all-cause mortality with a pooled RR 0.55 (95% CI, 0.45-0.66) and I2 of 82%. This effect was consistent across additional subgroup analyses, including stratification by study type, risk of bias, duration of follow-up, and antifibrotic subtype. Antifibrotic treatment also reduced the risk of AE, with a pooled RR of 0.63 (95% CI, 0.53-0.76), and I2 of 0%. Effect on AE risk was consistent across subgroup analyses by study type and for nintedanib but not for pirfenidone.

INTERPRETATION: Antifibrotic treatment appears to reduce the risk of all-cause mortality and AE in IPF. Despite greater heterogeneity with pooled analysis, its effect was robust in subgroup analyses by study type, duration of follow-up, and antifibrotic subtype.

PMID:34217681 | DOI:10.1016/j.chest.2021.06.049

Orphanet J Rare Dis. 2021 Jul 3;16(1):298. doi: 10.1186/s13023-021-01926-x.

ABSTRACT

BACKGROUND: Bronchoalveolar lavage (BAL) is one of the fundamental examinations for the differential diagnosis of interstitial lung diseases (ILDs), and lymphocytosis strongly indicates alternative diagnoses rather than idiopathic pulmonary fibrosis. However, the BALF lymphocytosis is observed in several ILDs. We considered that quantitative evaluation of the BALF lymphocyte nuclear morphology would be useful in the differential diagnosis of ILDs with increased BALF lymphocyte fraction.

RESULTS: One hundred and twenty-one patients with ILDs having increased BALF lymphocyte fraction were recruited (68 in the development cohort and 53 in the validation cohort). In the development cohort, BALF lymphocyte nuclei in sarcoidosis patients showed significantly smaller areas, shorter perimeters, lower radius ratios, and increased roundness than those of other ILD patients (p < 0.001 for each). Next, the fractions of lymphocytes with small areas, short perimeters, low radius ratios, and increased roundness, which were determined based on receiver operating characteristic (ROC) analyses-based thresholds, were demonstrated to be higher in sarcoidosis patients than in the other ILD patients (p < 0.001 for each). Furthermore, when we combined size-representing parameters with shape-representing parameters, the fraction of lymphocytes with small and round nuclei showed approximately 0.90 of area under the ROC curve in discriminating sarcoidosis both in the development cohort and the validation cohort.

CONCLUSION: This study is the first to demonstrate the usefulness of quantitative parameters of BALF lymphocyte nuclear morphology as novel biomarkers for sarcoidosis.

PMID:34217348 | DOI:10.1186/s13023-021-01926-x

Acta Histochem. 2021 Jun 30;123(5):151746. doi: 10.1016/j.acthis.2021.151746. Online ahead of print.

ABSTRACT

The precise etiology and pathogenesis of idiopathic pulmonary fibrosis are not completely understood, and no satisfactory treatment exists. This work aimed to examine the effects of calycosin (CA, an isoflavone compound) on pulmonary fibrosis (PF) and explore the underlying mechanism. In this study, we established a mice model of PF induced by 5 mg/mL bleomycin (BLM), and mice were orally administrated with 7 mg/kg or 14 mg/kg CA once a day for three weeks. In vitro, after pretreated with 80 μM CA, MLE-12 cells were stimulated with 10 ng/mL transforming growth factor-β1 (TGF-β1) for inducing epithelial-mesenchymal transition (EMT). The results showed that CA treatment ameliorated the severity of fibrosis and the lung tissue damage, as well as suppressed the secretion of inflammation factors in a dose-dependent manner of the PF mice model induced by BLM. Subsequently, CA inhibited the BLM-induced PF progression by repressing EMT, evidenced by the reverse of the downregulation of E-cadherin and the upregulation of vimentin, α-SMA, and fibronectin. Moreover, the elevated phosphorylation of AKT and GSK3β induced by BLM (or TGF-β1) was decreased by CA treatment, leading to the rescue of the high expression of β-catenin. CA prevented the translocation of β-catenin from the cytoplasm to the nucleus. The repressed effects of CA on the TGF-β1-induced EMT and the AKT/GSK3β/β-catenin axis, as well as the translocation of β-catenin were all reversed by a AKT activator SC79. Taken together, CA ameliorated PF by the EMT inhibition upon suppressing the AKT/GSK3β/β-catenin signaling pathway.

PMID:34217047 | DOI:10.1016/j.acthis.2021.151746

South Med J. 2021 Jul;114(7):424-431. doi: 10.14423/SMJ.0000000000001275.

ABSTRACT

OBJECTIVES: Obesity can be an independent predictor of fibrosis in tissues, including the liver, heart, and skin. We evaluated a rural Appalachian cohort of idiopathic pulmonary fibrosis (IPF) for its relation to obesity.

METHODS: Using American Thoracic Society 2018 diagnostic guidelines, an IPF cohort was systematically identified at an Appalachian academic medical center (2015-2019). The cohort was categorized in subgroups of body mass index (BMI) <30 or BMI ≥30 kg/m2. Demographics, clinical variables, and treatment details were collected retrospectively and evaluated for their associations with obesity.

RESULTS: In our IPF cohort (N = 138), a usual interstitial pneumonia pattern was less prevalent in the obese group (n = 49) relative to the nonobese group (69% vs 85%, respectively). The obese group was younger (mean age 73.27 ± 9.12 vs 77.97 ± 9.59 years) and had a higher prevalence of hypertension (90% vs 72%), hyperlipidemia (83% vs 68%), diabetes mellitus (47% vs 25%), sleep-disordered breathing (47% vs 25%), chronic pain disorders (28% vs 15%), and deep vein thrombosis (19% vs 7%). An increased proportion of obese-IPF patients was seen at a tertiary or an interstitial lung disease center, with more surgical lung biopsies performed and incident diagnosis (ie, within 6 months of presentation) assigned. Only a minority of patients underwent lung transplantation (3.6%), all of them from the obese-IPF subgroup. Approximately 30% of the total IPF cohort died, with a lower mortality observed in the obese group (35% vs 20%, P = 0.017). An increasing BMI predicted a better survival in the total IPF cohort (BMI 25-29.9, 20-24.9, and <20 had mortality rates of 20%, 47%, and 75%, respectively; P < 0.001).

CONCLUSIONS: Our study represents a first known effort to develop an IPF cohort in a rural Appalachian region. Although they shared an increased burden of comorbidities, the obese subgroup showed less advanced fibrosis with a lower mortality rate relative to nonobese subgroup, suggesting a potential "obesity paradox" in IPF. The study findings significantly advance our understanding of challenges posed by IPF in a rural population that also suffers from an alarming rate of obesity. We highlight the need for the multidisciplinary management of these patients and prospective studies to better define this complex relation.

PMID:34215896 | DOI:10.14423/SMJ.0000000000001275

Redox Biol. 2021 Jun 24;45:102055. doi: 10.1016/j.redox.2021.102055. Online ahead of print.

ABSTRACT

BACKGROUND: Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are linked to several mitochondrial alterations. Cigarette smoke (CS) alters the structure and function of mitochondria. OPA1 is the main inner mitochondrial GTPase responsible for the fusion events. OPA1 undergoes proteolytic cleavage from long to short forms during acute stress and mitophagy. However, the exact role of OPA1 isoforms and related proteins during CS-induced mitophagy and COPD is not clear.

METHODS: Lung tissues from non-smokers, smokers, COPD and IPF were used to determine the relative expression of OPA1 and related proteins. Additionally, we used mouse lungs from chronic (6 months) CS exposure to evaluate the status of OPA1. Primary lung fibroblasts from normal and COPD patients and naked mole rat (NMR) lung fibroblasts, human fetal lung fibroblast (HFL1), mouse embryonic fibroblast from wild type (WT), OPA1-/-, MFN1 and MFN2-/- were used to determine the effect of CS on OPA1 isoforms. Various mitochondrial fusion promoters/activators (BGP-15, leflunomide, M1) and fission inhibitor (DRP1) were used to determine their effect on OPA1 status and cigarette smoke extract (CSE)-induced lung epithelial (BEAS2B) cell damage, respectively. Seahorse flux analyzer was used to determine the effect of these compounds in BEAS2B cells with and without CSE exposure.

FINDINGS: Short OPA1 isoforms were predominantly detected and significantly increased in COPD subjects. Acute CSE treatment in various cell lines except NMR was found to increase the conversion of long to short OPA1 isoforms. CSE treatment significantly increased mitochondrial stress-related protein SLP2 in all the cells used. OPA1 interacting partners like prohibitins (PHB1 and 2) were also altered depending on the CS exposure. Finally, BGP-15 and leflunomide treatment were able to preserve the long OPA1 isoform in cells treated with CSE.

INTERPRETATION/CONCLUSION: The long OPA1 isoform along with SLP2 and prohibitins play a crucial role in CS-induced lung damage, causing mitophagy/mitochondrial dysfunction in COPD, which may be used as a novel therapeutic target in COPD.

PMID:34214709 | DOI:10.1016/j.redox.2021.102055

Lancet Respir Med. 2021 Jun 29:S2213-2600(21)00165-X. doi: 10.1016/S2213-2600(21)00165-X. Online ahead of print.

ABSTRACT

BACKGROUND: INCREASE was a randomised, placebo-controlled, phase 3 trial that evaluated inhaled treprostinil in patients with interstitial lung disease (ILD) and associated pulmonary hypertension. Treprostinil improved exercise capacity from baseline to week 16, assessed with the use of a 6-min walk test, compared with placebo. Improvements in forced vital capacity (FVC) were also reported. The aim of this post-hoc analysis was to further characterise the effects of inhaled treprostinil on FVC in the overall study population and in various subgroups of interest.

METHODS: In this post-hoc analysis, we evaluated FVC changes in the overall study population and in various subgroups defined by cause of disease or baseline clinical parameters. The study population included patients aged 18 years and older who had a diagnosis of ILD based on evidence of diffuse parenchymal lung disease on chest CT done within 6 months before random assignment (not centrally adjudicated). All analyses were done on the intention-to-treat population, defined as individuals who were randomly assigned and received at least one dose of study drug. The INCREASE study is registered with ClinicalTrials.gov, NCT02630316.

FINDINGS: Between Feb 3, 2017, and Aug 30, 2019, 326 patients were enrolled in the INCREASE trial. Inhaled treprostinil was associated with a placebo-corrected least squares mean improvement in FVC of 28·5 mL (SE 30·1; 95% CI -30·8 to 87·7; p=0·35) at week 8 and 44·4 mL (35·4; -25·2 to 114·0; p=0·21) at week 16, with associated percentage of predicted FVC improvements of 1·8% (0·7; 0·4 to 3·2; p=0·014) and 1·8% (0·8; 0·2 to 3·4; p=0·028). Subgroup analysis of patients with idiopathic interstitial pneumonia showed FVC differences of 46·5 mL (SE 39·9; 95% CI -32·5 to 125·5; p=0·25) at week 8 and 108·2 mL (46·9; 15·3 to 201·1; p=0·023) at week 16. Analysis of patients with idiopathic pulmonary fibrosis showed FVC differences of 84·5 mL (52·7; -20·4 to 189·5; p=0·11) at week 8 and 168·5 mL (64·5; 40·1 to 297·0; p=0·011) at week 16. The most frequent adverse events included cough, headache, dyspnoea, dizziness, nausea, fatigue, and diarrhoea.

INTERPRETATION: In patients with ILD and associated pulmonary hypertension, inhaled treprostinil was associated with improvements in FVC versus placebo at 16 weeks. This difference was most evident in patients with idiopathic interstitial pneumonia, particularly idiopathic pulmonary fibrosis. Inhaled treprostinil appears to be a promising therapy for idiopathic pulmonary fibrosis that warrants further investigation in a prospective, randomised, placebo-controlled study.

FUNDING: United Therapeutics Corporation.

PMID:34214475 | DOI:10.1016/S2213-2600(21)00165-X

Front Med (Lausanne). 2021 Jun 15;8:607720. doi: 10.3389/fmed.2021.607720. eCollection 2021.

ABSTRACT

Pulmonary fibrosis is characterized by abnormal interstitial extracellular matrix and cellular accumulations. Methods quantifying fibrosis severity in lung histopathology samples are semi-quantitative, subjective, and analyze only portions of sections. We sought to determine whether automated computerized imaging analysis shown to continuously measure fibrosis in mice could also be applied in human samples. A pilot study was conducted to analyze a small number of specimens from patients with Hermansky-Pudlak syndrome pulmonary fibrosis (HPSPF) or idiopathic pulmonary fibrosis (IPF). Digital images of entire lung histological serial sections stained with picrosirius red and alcian blue or anti-CD68 antibody were analyzed using dedicated software to automatically quantify fibrosis, collagen, and macrophage content. Automated fibrosis quantification based on parenchymal tissue density and fibrosis score measurements was compared to pulmonary function values or Ashcroft score. Automated fibrosis quantification of HPSPF lung explants was significantly higher than that of IPF lung explants or biopsies and was also significantly higher in IPF lung explants than in IPF biopsies. A high correlation coefficient was found between some automated quantification measurements and lung function values for the three sample groups. Automated quantification of collagen content in lung sections used for digital image analyses was similar in the three groups. CD68 immunolabeled cell measurements were significantly higher in HPSPF explants than in IPF biopsies. In conclusion, computerized image analysis provides access to accurate, reader-independent pulmonary fibrosis quantification in human histopathology samples. Fibrosis, collagen content, and immunostained cells can be automatically and individually quantified from serial sections. Robust automated digital image analysis of human lung samples enhances the available tools to quantify and study fibrotic lung disease.

PMID:34211981 | PMC:PMC8240807 | DOI:10.3389/fmed.2021.607720

Ther Adv Musculoskelet Dis. 2021 Jun 18;13:1759720X211022506. doi: 10.1177/1759720X211022506. eCollection 2021.

ABSTRACT

Interstitial lung disease (ILD) is frequently a complication of rheumatoid arthritis (RA) as an extra-articular manifestation which has a poor prognosis. Acute-onset diffuse ILD (AoDILD) occasionally occurs in RA and includes acute exacerbation of ILD, drug-induced ILD, and Pneumocystis pneumonia. AoDILD also confers a poor prognosis in RA. Previously-established biomarkers for ILD include Krebs von den lungen-6 and surfactant protein-D originally defined in patients with idiopathic pulmonary fibrosis; the sensitivity of these markers for RA-associated ILD (RA-ILD) is low. Although many studies on ILD markers have been performed in idiopathic pulmonary fibrosis, only a few validation studies in RA-ILD or AoDILD have been reported. Biomarkers for RA-ILD and AoDILD are thus still required. Recently, genomic, cytokine, antibody, and metabolomic profiles of RA-ILD or AoDILD have been investigated with the aim of improving biomarkers. In this review, we summarize current preliminary data on these potential biomarkers for RA-ILD or AoDILD. The development of biomarkers on RA-ILD has only just begun. When validated, such candidate biomarkers will provide valuable information on pathogenesis, prognosis, and drug responses in RA-ILD in future.

PMID:34211592 | PMC:PMC8216360 | DOI:10.1177/1759720X211022506

Eur Respir J. 2021 Jul 1:2004587. doi: 10.1183/13993003.04587-2020. Online ahead of print.

ABSTRACT

The INBUILD trial investigated nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs). We investigated decline in forced vital capacity (FVC) in subgroups based on the inclusion criteria for ILD progression.Subjects had a fibrosing ILD other than idiopathic pulmonary fibrosis and met these criteria for ILD progression within the 24 months before screening despite management deemed appropriate in clinical practice: Group A, relative decline in FVC ≥10% predicted; Group B, relative decline in FVC ≥5-<10% predicted with worsened respiratory symptoms and/or increased extent of fibrosis on HRCT; Group C, worsened respiratory symptoms and increased extent of fibrosis on HRCT only.In the placebo group, the rates of FVC decline over 52 weeks in Groups A, B and C, respectively, were -241.9, -133.1 and -115.3 mL·year-1 in the overall population (p=0.0002 for subgroup-by-time interaction) and -288.9, -156.2 and -100.1 mL·year-1 among subjects with a usual interstitial pneumonia [UIP]-like fibrotic pattern on HRCT (p=0.0005 for subgroup-by-time interaction). Nintedanib had a greater absolute effect on reducing the rate of FVC decline in Group A than Group B or C. However, the relative effect of nintedanib versus placebo was consistent across the subgroups (p>0.05 for heterogeneity).In conclusion, the inclusion criteria used in the INBUILD trial, based on FVC decline or worsening of symptoms and extent of fibrosis on HRCT, were effective at identifying patients with progressive fibrosing ILDs. Nintedanib reduced the rate of decline in FVC across the subgroups based on the inclusion criteria related to ILD progression.

PMID:34210788 | DOI:10.1183/13993003.04587-2020

Cells. 2021 Jun 29;10(7):1628. doi: 10.3390/cells10071628.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. Age is a major risk factor, and both alveolar epithelial cells and lung fibroblasts in this disease exhibit features of cellular senescence, a hallmark of ageing. Accumulation of fibrotic extracellular matrix (ECM) is a core feature of IPF and is likely to affect cell function. We hypothesize that aberrant ECM deposition augments fibroblast senescence, creating a perpetuating cycle favouring disease progression. In this study, primary lung fibroblasts were cultured on control and IPF-derived ECM from fibroblasts pretreated with or without profibrotic and prosenescent stimuli, and markers of senescence, fibrosis-associated gene expression and secretion of cytokines were measured. Untreated ECM derived from control or IPF fibroblasts had no effect on the main marker of senescence p16Ink4a and p21Waf1/Cip1. However, the expression of alpha smooth muscle actin (ACTA2) and proteoglycan decorin (DCN) increased in response to IPF-derived ECM. Production of the proinflammatory cytokines C-X-C Motif Chemokine Ligand 8 (CXCL8) by lung fibroblasts was upregulated in response to senescent and profibrotic-derived ECM. Finally, the profibrotic cytokines transforming growth factor β1 (TGF-β1) and connective tissue growth factor (CTGF) were upregulated in response to both senescent- and profibrotic-derived ECM. In summary, ECM deposited by IPF fibroblasts does not induce cellular senescence, while there is upregulation of proinflammatory and profibrotic cytokines and differentiation into a myofibroblast phenotype in response to senescent- and profibrotic-derived ECM, which may contribute to progression of fibrosis in IPF.

PMID:34209854 | DOI:10.3390/cells10071628