Idiopathic Pulmonary Fibrosis

Advances in the Use of <em>N</em>-Acetylcysteine in Chronic Respiratory Diseases

Thu, 2023-09-28 06:00

Antioxidants (Basel). 2023 Sep 2;12(9):1713. doi: 10.3390/antiox12091713.

ABSTRACT

N-acetylcysteine (NAC) is widely used because of its mucolytic effects, taking part in the therapeutic protocols of cystic fibrosis. NAC is also administered as an antidote in acetaminophen (paracetamol) overdosing. Thanks to its wide antioxidative and anti-inflammatory effects, NAC may also be of benefit in other chronic inflammatory and fibrotizing respiratory diseases, such as chronic obstructive pulmonary disease, bronchial asthma, idiopathic lung fibrosis, or lung silicosis. In addition, NAC exerts low toxicity and rare adverse effects even in combination with other treatments, and it is cheap and easily accessible. This article brings a review of information on the mechanisms of inflammation and oxidative stress in selected chronic respiratory diseases and discusses the use of NAC in these disorders.

PMID:37760016 | DOI:10.3390/antiox12091713

Categories: Literature Watch

The Role of Mitochondrial Dysfunction in Idiopathic Pulmonary Fibrosis: New Perspectives for a Challenging Disease

Thu, 2023-09-28 06:00

Biology (Basel). 2023 Sep 14;12(9):1237. doi: 10.3390/biology12091237.

ABSTRACT

Mitochondrial biology has always been a relevant field in chronic diseases such as fibrosis or cancer in different organs of the human body, not to mention the strong association between mitochondrial dysfunction and aging. With the development of new technologies and the emergence of new methodologies in the last few years, the role of mitochondria in pulmonary chronic diseases such as idiopathic pulmonary fibrosis (IPF) has taken an important position in the field. With this review, we will highlight the latest advances in mitochondrial research on pulmonary fibrosis, focusing on the role of the mitochondria in the aging lung, new proposals for mechanisms that support mitochondrial dysfunction as an important cause for IPF, mitochondrial dysfunction in different cell populations of the lung, and new proposals for treatment of the disease.

PMID:37759636 | DOI:10.3390/biology12091237

Categories: Literature Watch

Pulmonary Sequelae of COVID-19: Focus on Interstitial Lung Disease

Thu, 2023-09-28 06:00

Cells. 2023 Sep 8;12(18):2238. doi: 10.3390/cells12182238.

ABSTRACT

As the world transitions from the acute phase of the COVID-19 pandemic, a novel concern has arisen-interstitial lung disease (ILD) as a consequence of SARS-CoV-2 infection. This review discusses what we have learned about its epidemiology, radiological, and pulmonary function findings, risk factors, and possible management strategies. Notably, the prevailing radiological pattern observed is organising pneumonia, with ground-glass opacities and reticulation frequently reported. Longitudinal studies reveal a complex trajectory, with some demonstrating improvement in lung function and radiographic abnormalities over time, whereas others show more static fibrotic changes. Age, disease severity, and male sex are emerging as risk factors for residual lung abnormalities. The intricate relationship between post-COVID ILD and idiopathic pulmonary fibrosis (IPF) genetics underscores the need for further research and elucidation of shared pathways. As this new disease entity unfolds, continued research is vital to guide clinical decision making and improve outcomes for patients with post-COVID ILD.

PMID:37759460 | DOI:10.3390/cells12182238

Categories: Literature Watch

Lung extracellular matrix modulates KRT5<sup>+</sup> basal cell activity in pulmonary fibrosis

Wed, 2023-09-27 06:00

Nat Commun. 2023 Sep 27;14(1):6039. doi: 10.1038/s41467-023-41621-y.

ABSTRACT

Aberrant expansion of KRT5+ basal cells in the distal lung accompanies progressive alveolar epithelial cell loss and tissue remodelling during fibrogenesis in idiopathic pulmonary fibrosis (IPF). The mechanisms determining activity of KRT5+ cells in IPF have not been delineated. Here, we reveal a potential mechanism by which KRT5+ cells migrate within the fibrotic lung, navigating regional differences in collagen topography. In vitro, KRT5+ cell migratory characteristics and expression of remodelling genes are modulated by extracellular matrix (ECM) composition and organisation. Mass spectrometry- based proteomics revealed compositional differences in ECM components secreted by primary human lung fibroblasts (HLF) from IPF patients compared to controls. Over-expression of ECM glycoprotein, Secreted Protein Acidic and Cysteine Rich (SPARC) in the IPF HLF matrix restricts KRT5+ cell migration in vitro. Together, our findings demonstrate how changes to the ECM in IPF directly influence KRT5+ cell behaviour and function contributing to remodelling events in the fibrotic niche.

PMID:37758700 | DOI:10.1038/s41467-023-41621-y

Categories: Literature Watch

Evaluating Tissue Heterogeneity in the Radiologically Normal-Appearing Tissue in IPF Compared to Healthy Controls

Wed, 2023-09-27 06:00

Acad Radiol. 2023 Sep 25:S1076-6332(23)00467-1. doi: 10.1016/j.acra.2023.08.046. Online ahead of print.

ABSTRACT

RATIONALE AND OBJECTIVES: Idiopathic Pulmonary Fibrosis (IPF) is a progressive interstitial lung disease characterised by heterogeneously distributed fibrotic lesions. The inter- and intra-patient heterogeneity of the disease has meant that useful biomarkers of severity and progression have been elusive. Previous quantitative computed tomography (CT) based studies have focussed on characterising the pathological tissue. However, we hypothesised that the remaining lung tissue, which appears radiologically normal, may show important differences from controls in tissue characteristics.

MATERIALS AND METHODS: Quantitative metrics were derived from CT scans in IPF patients (N = 20) and healthy controls with a similar age (N = 59). An automated quantitative software (CALIPER, Computer-Aided Lung Informatics for Pathology Evaluation and Rating) was used to classify tissue as normal-appearing, fibrosis, or low attenuation area. Densitometry metrics were calculated for all lung tissue and for only the normal-appearing tissue. Heterogeneity of lung tissue density was quantified as coefficient of variation and by quadtree. Associations between measured lung function and quantitative metrics were assessed and compared between the two cohorts.

RESULTS: All metrics were significantly different between controls and IPF (p < 0.05), including when only the normal tissue was evaluated (p < 0.04). Density in the normal tissue was 14% higher in the IPF participants than controls (p < 0.001). The normal-appearing tissue in IPF had heterogeneity metrics that exhibited significant positive relationships with the percent predicted diffusion capacity for carbon monoxide.

CONCLUSION: We provide quantitative assessment of IPF lung tissue characteristics compared to a healthy control group of similar age. Tissue that appears visually normal in IPF exhibits subtle but quantifiable differences that are associated with lung function and gas exchange.

PMID:37758587 | DOI:10.1016/j.acra.2023.08.046

Categories: Literature Watch

Effect of Mycetoma in Lung Transplant Patients - a Single Center Experience

Wed, 2023-09-27 06:00

Transplant Proc. 2023 Sep 25:S0041-1345(23)00574-2. doi: 10.1016/j.transproceed.2023.08.005. Online ahead of print.

ABSTRACT

BACKGROUND: Mycetomas are uncommon in lung transplant recipients. Prior studies have shown increased mortality associated with mycetoma in lung transplant recipients (LTR). We reviewed our center's experience in outcome of LTRs with pre -or post-transplant mycetoma.

METHODS: We retrospectively reviewed electronic health records of LTRs performed at our institute between January 1, 2013 to December 31, 2020.

RESULTS: Mycetoma was present in less than 1 percent of LTR patients (7/1086). Mean age at the time of the transplant was 65 years. Idiopathic pulmonary fibrosis (5/7), interstitial lung disease (1/7), and sarcoidosis (1/7) were underlying pulmonary diagnoses. Seventy-one percent (5/7) received single lung transplant and 29% received double lung transplant. Seventy-one percent had negative serum galactomannan vs 29% (2/7) of patients who had positive serum galactomannan (one post and one pre). Fifty-seven percent had positive bronchoalveolar aspergillus galactomannan (23% had negative). A total of 42% (3/7) were found to have mycetoma before transplant and 58% (4/7) had mycetoma post transplant. Chest computed tomography findings in all patients were consistent with mycetoma.

CONCLUSIONS: In our cohort of patients, mycetoma was not found to be the primary cause of death if diagnosed pre transplant. Transplant recipients with mycetoma pre transplant did not develop invasive fungal infection or mycetoma post transplant. Careful evaluation of lung transplant candidates with mycetoma is critical. Further studies are needed to determine optimal duration of antifungal therapy and to determine if surgical resection may be needed to manage post-lung transplant mycetoma.

PMID:37758562 | DOI:10.1016/j.transproceed.2023.08.005

Categories: Literature Watch

The impact of nintedanib and pirfenidone on lung function and survival in patients with idiopathic pulmonary fibrosis in real-life setting

Wed, 2023-09-27 06:00

Pulm Pharmacol Ther. 2023 Sep 25:102261. doi: 10.1016/j.pupt.2023.102261. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing interstitial pneumonia of unknown cause that is associated with radiological and/or histological features of usual interstitial pneumonia (UIP). A mean survival of 2-5 years was reported previously to the advent of antifibrotics. According to clinical trials, nintedanib and pirfenidone induce a significant delay in functional decline, with a favorable impact on survival.

METHODS: A real-life retrospective and longitudinal study was conducted to assess the efficacy and tolerability of antifibrotics in IPF patients, between January 2014 and December 2020. Two groups (under nintedanib or pirfenidone) were analyzed at diagnosis through their clinical features and radiological patterns. Lung function was assessed at diagnosis (time 0) and after 6, 12 and 24 months of treatment. We also compared this antifibrotic cohort with an older naïve antifibrotic cohort, mainly treated with immunosuppressive drugs and/or N- acetylcysteine. Survival was analyzed and prognostic features were also studied. Statistical analysis was performed with IBM® SPSS®.

RESULTS: A cohort of 108 patients under antifibrotics (nintedanib n = 54; pirfenidone n = 54) was assessed. Lung function analysis showed an overall stabilization in FVC and DLCO mean predicted percentages at 6, 12 and 24 months of treatment. The mean decline in FVC and DLCO, at 12 months, was -40.95 ± 438.26 mL and -0.626 ± 1.31 mL/min/mmHg, respectively. However, during this period, 34.2% of the patients died mostly due to acute exacerbation associated with a poorer lung function at diagnosis. Mean survival in the naïve antifibrotic cohort was significantly lower than in the antifibrotic cohort (39.9 months versus 58.2 months; p < 0.005). Regarding lung function evolution and survival, we found no differences between definitive or probable UIP radiological patterns, both on patients under nintedanib and pirfenidone (p = 0.656).

CONCLUSIONS: In this real-life observational study, the positive impact of antifibrotic therapy on the IPF clinical course and on survival was corroborated. Regarding efficacy, there was no difference between patients taking nintedanib or pirfenidone. The need for an early treatment was also demonstrated, since a worse outcome is clearly associated with lower lung volumes and lower diffusing capacity at diagnosis.

PMID:37758002 | DOI:10.1016/j.pupt.2023.102261

Categories: Literature Watch

The impact of deep learning reconstruction in low dose computed tomography on the evaluation of interstitial lung disease

Wed, 2023-09-27 06:00

PLoS One. 2023 Sep 27;18(9):e0291745. doi: 10.1371/journal.pone.0291745. eCollection 2023.

ABSTRACT

To evaluate the effect of the deep learning model reconstruction (DLM) method in terms of image quality and diagnostic agreement in low-dose computed tomography (LDCT) for interstitial lung disease (ILD), 193 patients who underwent LDCT for suspected ILD were retrospectively reviewed. Datasets were reconstructed using filtered back projection (FBP), adaptive statistical iterative reconstruction Veo (ASiR-V), and DLM. For image quality analysis, the signal, noise, signal-to-noise ratio (SNR), blind/referenceless image spatial quality evaluator (BRISQUE), and visual scoring were evaluated. Also, CT patterns of usual interstitial pneumonia (UIP) were classified according to the 2022 idiopathic pulmonary fibrosis (IPF) diagnostic criteria. The differences between CT images subjected to FBP, ASiR-V 30%, and DLM were evaluated. The image noise and BRISQUE scores of DLM images was lower and SNR was higher than that of the ASiR-V and FBP images (ASiR-V vs. DLM, p < 0.001 and FBP vs. DLR-M, p < 0.001, respectively). The agreement of the diagnostic categorization of IPF between the three reconstruction methods was almost perfect (κ = 0.992, CI 0.990-0.994). Image quality was improved with DLM compared to ASiR-V and FBP.

PMID:37756357 | DOI:10.1371/journal.pone.0291745

Categories: Literature Watch

Externalized histones fuel pulmonary fibrosis via a platelet-macrophage circuit of TGFβ1 and IL-27

Wed, 2023-09-27 06:00

Proc Natl Acad Sci U S A. 2023 Oct 3;120(40):e2215421120. doi: 10.1073/pnas.2215421120. Epub 2023 Sep 27.

ABSTRACT

Externalized histones erupt from the nucleus as extracellular traps, are associated with several acute and chronic lung disorders, but their implications in the molecular pathogenesis of interstitial lung disease are incompletely defined. To investigate the role and molecular mechanisms of externalized histones within the immunologic networks of pulmonary fibrosis, we studied externalized histones in human and animal bronchoalveolar lavage (BAL) samples of lung fibrosis. Neutralizing anti-histone antibodies were administered in bleomycin-induced fibrosis of C57BL/6 J mice, and subsequent studies used conditional/constitutive knockout mouse strains for TGFβ and IL-27 signaling along with isolated platelets and cultured macrophages. We found that externalized histones (citH3) were significantly (P < 0.01) increased in cell-free BAL fluids of patients with idiopathic pulmonary fibrosis (IPF; n = 29) as compared to healthy controls (n = 10). The pulmonary sources of externalized histones were Ly6G+CD11b+ neutrophils and nonhematopoietic cells after bleomycin in mice. Neutralizing monoclonal anti-histone H2A/H4 antibodies reduced the pulmonary collagen accumulation and hydroxyproline concentration. Histones activated platelets to release TGFβ1, which signaled through the TGFbRI/TGFbRII receptor complex on LysM+ cells to antagonize macrophage-derived IL-27 production. TGFβ1 evoked multiple downstream mechanisms in macrophages, including p38 MAPK, tristetraprolin, IL-10, and binding of SMAD3 to the IL-27 promotor regions. IL-27RA-deficient mice displayed more severe collagen depositions suggesting that intact IL-27 signaling limits fibrosis. In conclusion, externalized histones inactivate a safety switch of antifibrotic, macrophage-derived IL-27 by boosting platelet-derived TGFβ1. Externalized histones are accessible to neutralizing antibodies for improving the severity of experimental pulmonary fibrosis.

PMID:37756334 | DOI:10.1073/pnas.2215421120

Categories: Literature Watch

No effect of danazol treatment in patients with advanced idiopathic pulmonary fibrosis

Wed, 2023-09-27 06:00

ERJ Open Res. 2023 Sep 25;9(5):00131-2023. doi: 10.1183/23120541.00131-2023. eCollection 2023 Sep.

ABSTRACT

BACKGROUND: Telomere dysfunction can underly the development of idiopathic pulmonary fibrosis (IPF), and recent work suggests that patients with telomere syndromes might benefit from treatment with androgens, such as danazol.

METHODS: This was a prospective observational cohort study. 50 patients with IPF received off-label treatment with danazol after they showed progressive disease under treatment with pirfenidone or nintedanib. The primary outcome was the difference in yearly decline in forced vital capacity (FVC) prior to (pre) and after (post) start of treatment with danazol.

RESULTS: There was no significant difference in FVC-decline between 1 year pre and 1 year post start of danazol treatment (mean decline pre 395 mL (95% confidence interval (CI) 290-500) compared to post 461 mL (95% CI 259-712); p=0.46; paired t-test). 11 patients (22%) were still on danazol after 1 year, and 39 patients had stopped danazol, mainly because of side-effects (56%) or death (33%). In patients who were still using danazol after 1 year, FVC-decline significantly slowed down under danazol treatment (mean pre 512 mL (95% CI 308-716) versus post 198 mL (95% CI 16-380); p=0.04). Median survival post danazol was 14.9 months (95% CI 11.0-18.8).

CONCLUSION: Danazol as a treatment of last resort in patients with IPF did not lead to slowing of lung function decline and was associated with significant side-effects. It remains to be determined if earlier treatment or treatment of specific patient subgroups is beneficial.

PMID:37753281 | PMC:PMC10518878 | DOI:10.1183/23120541.00131-2023

Categories: Literature Watch

Prevalence and clinical impacts of obstructive sleep apnea in patients with idiopathic pulmonary fibrosis: A single-center, retrospective study

Tue, 2023-09-26 06:00

PLoS One. 2023 Sep 26;18(9):e0291195. doi: 10.1371/journal.pone.0291195. eCollection 2023.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with chronic, progressive lung fibrosis with a poor prognosis. Recent studies have reported a high prevalence of obstructive sleep apnea (OSA) in IPF patients and an association with poor prognosis. This study aimed to evaluate the prevalence, risk factors, and clinical effects on mortality of OSA in patients with IPF.

METHODS: Clinical data were retrospectively analyzed in 167 patients with IPF at Haeundae-Paik Hospital, Republic of Korea. A type 4 portable device was used to monitor OSA, and an apnea-hypopnea index of 5 events per sleep hour and above was diagnosed as OSA.

RESULTS: The mean follow-up period and age were 26.9 months and 71.4 years, respectively, with male predominance. OSA was confirmed in 108 patients (64.7%). Mild OSA was the most common (62.1%). Independent risk factors for OSA in the multivariate logistic regression analysis were age (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.02-1.13, p = 0.007), body weight (OR 1.05, 95% CI 1.02-1.09, p = 0.002), and risk based on the Berlin questionnaire (OR 2.76, 95% CI 1.12-6.80, p = 0.028). Shorter six-minute walk distance (6MWD) (hazard ratio [HR] 1.00, 95% CI: 1.00-1.00, p < 0.001), acute exacerbation (AE) (HR 13.83, 95% CI: 5.71-33.47, p < 0.001), and higher percentage of cumulative time with oxygen saturation below 90% in total sleep time (HR 1.08, 95% CI: 1.02-1.14, p = 0.007) were risk factors for mortality in IPF patients in the Cox regression analysis.

CONCLUSION: Approximately two-thirds of the IPF patients had OSA. Older age, higher body weight, and high risk based on the Berlin questionnaire were independent risk factors for OSA in IPF patients. Shorter 6MWD, experience of AE, and night hypoxemia during sleep were associated with a higher risk of mortality in patients with IPF.

PMID:37751461 | DOI:10.1371/journal.pone.0291195

Categories: Literature Watch

Effect of Nintedanib in Patients with Progressive Pulmonary Fibrosis in Subgroups with Differing Baseline Characteristics

Tue, 2023-09-26 06:00

Adv Ther. 2023 Sep 26. doi: 10.1007/s12325-023-02668-x. Online ahead of print.

ABSTRACT

INTRODUCTION: In the INBUILD trial in patients with progressive pulmonary fibrosis other than idiopathic pulmonary fibrosis (IPF), nintedanib slowed the rate of decline in forced vital capacity (FVC; mL/year) over 52 weeks compared with placebo. We assessed the efficacy of nintedanib across subgroups in the INBUILD trial by baseline characteristics.

METHODS: We assessed the rate of decline in FVC over 52 weeks and time to progression of interstitial lung disease (ILD) (absolute decline from baseline in FVC % predicted > 10%) or death over the whole trial in subgroups based on sex, age, race, body mass index (BMI), time since diagnosis of ILD, FVC % predicted, diffusing capacity of the lungs for carbon monoxide (DLco) % predicted, composite physiologic index (CPI), GAP (gender, age, lung physiology) stage, use of anti-acid therapy and use of disease-modifying antirheumatic drugs (DMARDs) at baseline.

RESULTS: The effect of nintedanib versus placebo on reducing the rate of decline in FVC over 52 weeks was consistent across the subgroups by baseline characteristics analysed. Interaction p values did not indicate heterogeneity in the treatment effect between these subgroups (p > 0.05). Over the whole trial (median follow-up time ∼19 months), progression of ILD or death occurred in similar or lower proportions of patients treated with nintedanib than placebo across the subgroups analysed, with no heterogeneity detected between the subgroups.

CONCLUSIONS: In the INBUILD trial, no heterogeneity was detected in the effect of nintedanib on reducing the rate of ILD progression across subgroups based on demographics, ILD severity or use of anti-acid therapy or DMARDs. These data support the use of nintedanib as a treatment for progressive pulmonary fibrosis.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT02999178.

PMID:37751022 | DOI:10.1007/s12325-023-02668-x

Categories: Literature Watch

Epithelial alarmins: a new target to treat chronic respiratory diseases

Mon, 2023-09-25 06:00

Expert Rev Respir Med. 2023 Sep 25. doi: 10.1080/17476348.2023.2262920. Online ahead of print.

ABSTRACT

INTRODUCTION: In response to injury, epithelial cells release alarmins including thymic stromal lymphopoietin (TSLP), high mobility group-box-1 (HMGB1), interleukin (IL)-33 and -25 that can initiate innate immune responses. These alarmins are recognized as activators of T2-immune responses characteristic for asthma, but recent evidence highlighted their role in non-T2 inflammation, airway remodeling and pulmonary fibrosis making them an attractive therapeutic target for chronic respiratory diseases (CRD).

AREAS COVERED: In this review, firstly we discuss the role of TSLP, IL-33, IL-25 and HMGB1 in the pathogenesis of asthma, COPD, idiopathic pulmonary fibrosis and cystic fibrosis according to the published data. In the second part, we summarize the current evidence concerning the efficacy of the antialarmin therapies in CRD. Recent clinical trials showed that anti-TSLP and IL-33/R antibodies can improve severe asthma outcomes. Blocking the IL-33-mediated pathway decreased the exacerbation rates in COPD patients with more important benefit for former-smokers.

EXPERT OPINION: Despite progress in the understanding of the alarmins' role in the pathogenesis of CRD, all their mechanisms of action are not yet identified. Blocking IL-33 and TSLP pathways offer an interesting option to treat severe asthma and COPD but future investigations are needed to established their place in the treatment strategies.

PMID:37746733 | DOI:10.1080/17476348.2023.2262920

Categories: Literature Watch

Increased lipocalin-2 expression in pulmonary inflammation and fibrosis

Mon, 2023-09-25 06:00

Front Med (Lausanne). 2023 Sep 7;10:1195501. doi: 10.3389/fmed.2023.1195501. eCollection 2023.

ABSTRACT

INTRODUCTION: Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive interstitial lung disease with dismal prognosis. The underlying pathogenic mechanisms are poorly understood, resulting in a lack of effective treatments. However, recurrent epithelial damage is considered critical for disease initiation and perpetuation, via the secretion of soluble factors that amplify inflammation and lead to fibroblast activation and exuberant deposition of ECM components. Lipocalin-2 (LCN2) is a neutrophil gelatinase-associated lipocalin (NGAL) that has been suggested as a biomarker of kidney damage. LCN2 has been reported to modulate innate immunity, including the recruitment of neutrophils, and to protect against bacterial infections by sequestering iron.

METHODS: In silico analysis of publicly available transcriptomic datasets; ELISAs on human IPF patients' bronchoalveolar lavage fluids (BALFs); bleomycin (BLM)-induced pulmonary inflammation and fibrosis and LPS-induced acute lung injury (ALI) in mice: pulmonary function tests, histology, Q-RT-PCR, western blot, and FACS analysis.

RESULTS AND DISCUSSION: Increased LCN2 mRNA expression was detected in the lung tissue of IPF patients negatively correlating with respiratory functions, as also shown for BALF LCN2 protein levels in a cohort of IPF patients. Increased Lcn2 expression was also detected upon BLM-induced pulmonary inflammation and fibrosis, especially at the acute phase correlating with neutrophilic infiltration, as well as upon LPS-induced ALI, an animal model characterized by neutrophilic infiltration. Surprisingly, and non withstanding the limitations of the study and the observed trends, Lcn2-/- mice were found to still develop BLM- or LPS-induced pulmonary inflammation and fibrosis, thus questioning a major pathogenic role for Lcn2 in mice. However, LCN2 qualifies as a surrogate biomarker of pulmonary inflammation and a possible indicator of compromised pulmonary functions, urging for larger studies.

PMID:37746070 | PMC:PMC10513431 | DOI:10.3389/fmed.2023.1195501

Categories: Literature Watch

Proximal immune-epithelial progenitor interactions drive chronic tissue sequelae post COVID-19

Mon, 2023-09-25 06:00

bioRxiv. 2023 Sep 14:2023.09.13.557622. doi: 10.1101/2023.09.13.557622. Preprint.

ABSTRACT

The long-term health effects of SARS-CoV-2, termed Post-Acute Sequelae of COVID-19 (PASC), are quickly evolving into a major public health concern, but the underlying cellular and molecular etiology remain poorly defined. There is growing evidence that PASC is linked to abnormal immune responses and/or poor organ recovery post-infection. However, the exact processes linking non-resolving inflammation, impaired tissue repair, and PASC are still unclear. In this report, we utilized a cohort of respiratory PASC patients with viral infection-mediated pulmonary fibrosis and a clinically relevant mouse model of post-viral lung sequelae to investigate the pathophysiology of respiratory PASC. Using a combination of imaging and spatial transcriptomics, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to respiratory PASC but not acute COVID-19 or idiopathic pulmonary fibrosis (IPF). Specifically, we found a central role for lung-resident CD8 + T cell-macrophage interactions in maintaining Krt8 hi transitional and ectopic Krt5 + basal cell progenitors, and the development of fibrotic sequelae after acute viral pneumonia. Mechanistically, CD8 + T cell derived IFN-γ and TNF stimulated lung macrophages to chronically release IL-1β, resulting in the abnormal accumulation of dysplastic epithelial progenitors in fibrotic areas. Notably, therapeutic neutralization of IFN-γ and TNF, or IL-1β after the resolution of acute infection resulted in markedly improved alveolar regeneration and restoration of pulmonary function. Together, our findings implicate a dysregulated immune-epithelial progenitor niche in driving respiratory PASC and identify potential therapeutic targets to dampen chronic pulmonary sequelae post respiratory viral infections including SARS-CoV-2.

PMID:37745354 | PMC:PMC10515929 | DOI:10.1101/2023.09.13.557622

Categories: Literature Watch

H3K18 lactylation promotes the progression of arsenite-related idiopathic pulmonary fibrosis via YTHDF1/m6A/NREP

Sun, 2023-09-24 06:00

J Hazard Mater. 2023 Sep 19;461:132582. doi: 10.1016/j.jhazmat.2023.132582. Online ahead of print.

ABSTRACT

As epigenetic modifications, lactylation and N6-methyladenosine (m6A) have attracted wide attention. Arsenite is an environmental pollutant that has been proven to induce idiopathic pulmonary fibrosis (IPF). However, the molecular mechanisms of lactylation and m6A methylation are unclear in arsenite-related IPF (As-IPF). In view of the limited understanding of molecular mechanism of m6A and lactylation in As-IPF, MeRIP-seq, RNA-seq and ChIP-seq were analyzed to verify the target gene regulated by m6A and H3K18 lactylation (H3K18la). We found that, for As-IPF, the global levels of m6A, levels of YTHDF1 and m6A-modified neuronal protein 3.1 (NREP) were elevated in alveolar epithelial cells (AECs). The secretion levels of TGF-β1 were increased via YTHDF1/m6A/NREP, which promoted the fibroblast-to-myofibroblast transition (FMT). Further, extracellular lactate from myofibroblasts elevated levels of the global lactylation (Kla) and H3K18la via the lactate monocarboxylate transporter 1 (MCT1), and, in AECs, H3K18la facilitated the transcription of Ythdf1. This report highlights the role of crosstalk between AECs and myofibroblasts via lactylation and m6A and the significance of H3K18la regulation of YTHDF1 in the progression of As-IPF, which may be useful for finding effective therapeutic targets.

PMID:37742376 | DOI:10.1016/j.jhazmat.2023.132582

Categories: Literature Watch

A novel BRD4 degrader, ARV-825, attenuates lung fibrosis through senolysis and antifibrotic effect

Sat, 2023-09-23 06:00

Respir Investig. 2023 Sep 21;61(6):781-792. doi: 10.1016/j.resinv.2023.08.003. Online ahead of print.

ABSTRACT

BACKGROUND: Recent studies suggest that cellular senescence is related to the pathogenesis of idiopathic pulmonary fibrosis. However, cellular senescence has yet to be targeted therapeutically in clinical practice. ARV825, a recently developed BRD4 degrader, has been reported as a novel senolytic drug. Conversely, it has also been reported that BRD4 regulates the pro-fibrotic gene expression of fibroblasts. Therefore, this study focuses on the senolytic and anti-fibrotic effects of ARV825 and evaluated these effects on lung fibrosis.

METHODS: Lung fibroblasts were induced to senescence through serial passage. The expression of senescence markers and pro-fibrotic markers were determined through quantitative PCR or immunoblot analysis. Lung fibrosis was induced in mice through intratracheal administration of bleomycin. Mice treated with ARV825 underwent histological analysis of lung fibrosis using the Ashcroft score. Total lung collagen was quantified through a hydroxyproline assay. Respiratory mechanics analysis was performed using the flexiVent system.

RESULTS: For senescent cells, ARV825 induced the expression of an apoptosis marker while reducing the expression of BRD4 and senescence markers. On the other hand, for early passage pre-senescent cells, ARV825 reduced the expression of collagen type 1 and α-smooth muscle actin. In an experimental mouse model of lung fibrosis, ARV825 attenuated lung fibrosis and improved lung function. Immunohistochemical staining revealed a significant decrease in the number of senescent alveolar type 2 cells in lung tissue due to ARV825 treatment.

CONCLUSIONS: These results suggest that ARV825 may impact the progressive and irreversible course of fibrotic lung diseases.

PMID:37741093 | DOI:10.1016/j.resinv.2023.08.003

Categories: Literature Watch

Epithelial-fibroblast interactions in IPF: Lessons from in vitro co-culture studies

Fri, 2023-09-22 06:00

Differentiation. 2023 Sep 12;134:11-19. doi: 10.1016/j.diff.2023.09.001. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial disease that is characterized by increased cellular proliferation and differentiation together with excessive extracellular matrix (ECM) deposition leading to buildup of scar tissue (fibrosis) and remodeling in the lungs. The activated and differentiated (myo)fibroblasts are one of the main sources of tissue remodeling in IPF and a crucial mechanism known to contribute to this feature is an aberrant crosstalk between pulmonary fibroblasts and the abnormal or injured pulmonary epithelium. This epithelial-fibroblast interaction mimics the temporal, spatial and cell-type specific crosstalk between the endoderm and mesoderm in the so-called epithelial-mesenchymal trophic unit (EMTU) during lung development that is proposed to be activated in healthy lung repair and dysregulated in various lung diseases including IPF. To study the dysregulated lung EMTU in IPF, various complex in vitro models have been established. Hence, in this review, we will provide a summary of studies that have used complex (3-dimensional) in vitro co-culture, and organoid models to assess how abnormal epithelial-fibroblast interactions in lung EMTU contribute to crucial features of the IPF including defective cellular differentiation, proliferation and migration as well as increased ECM deposition.

PMID:37738701 | DOI:10.1016/j.diff.2023.09.001

Categories: Literature Watch

A Phase I Study of TRK-250, a Novel siRNA-Based Oligonucleotide, in Patients with Idiopathic Pulmonary Fibrosis

Fri, 2023-09-22 06:00

J Aerosol Med Pulm Drug Deliv. 2023 Sep 22. doi: 10.1089/jamp.2023.0014. Online ahead of print.

ABSTRACT

Purpose: TRK-250 is a novel single-stranded oligonucleotide carrying a human Transforming growth factor-beta 1-targeting siRNA motif tethered by two proline linkers. Nonclinical studies have shown that TRK-250 may have potency to prevent the progression of pulmonary fibrosis. Herein, a phase I study was conducted to investigate the safety and pharmacokinetics (PKs) of TRK-250 in patients with idiopathic pulmonary fibrosis (IPF). Method: In the phase I study, 34 IPF patients were partially randomized to receive a placebo or TRK-250 in 4 single doses of 2, 10, 30, and 60 mg or multiple rising doses of 10, 30, and 60 mg once per week for 4 weeks by oral inhalation. For both the single- and multiple-dose studies, the primary endpoint was safety, and the secondary endpoint was PKs. Result: In all IPF patients who orally inhaled TRK-250, no significant drug-related adverse events (AEs) were observed. The AEs were mild or moderate, except for one severe case with acute exacerbation. One of the more common AEs was coughing. One patient discontinued treatment before the last dose because of coughing. There were no medically important findings related to safety endpoints based on clinical laboratory data (clinical chemistry, hematology, or urinalysis), vital signs data, electrocardiogram data, physical examination findings, pulse oximetry data, spirometry data, or diffusing capacity of the lung for carbon monoxide data. All the bioanalytical results of PKs in the blood were below the lower limit of quantification. Conclusions: Both the single and multiple doses of TRK-250 were safe and well tolerated in this first study done in IPF patients. Furthermore, TRK-250 was not detected in the systemic circulation following inhalation, indicating low or virtually nonexistent systemic exposure. This study is registered at ClinicalTrials.gov with identifier number NCT03727802.

PMID:37738329 | DOI:10.1089/jamp.2023.0014

Categories: Literature Watch

Pages