Idiopathic Pulmonary Fibrosis

Mass spectrometry-based autoimmune profiling reveals predictive autoantigens in idiopathic pulmonary fibrosis

Wed, 2023-11-29 06:00

iScience. 2023 Oct 27;26(11):108345. doi: 10.1016/j.isci.2023.108345. eCollection 2023 Nov 17.

ABSTRACT

Autoimmunity plays a role in certain types of lung fibrosis, notably connective tissue disease-associated interstitial lung disease (CTD-ILD). In idiopathic pulmonary fibrosis (IPF), an incurable and fatal lung disease, diagnosis typically requires clinical exclusion of autoimmunity. However, autoantibodies of unknown significance have been detected in IPF patients. We conducted computational analysis of B cell transcriptomes in published transcriptomics datasets and developed a proteomic Differential Antigen Capture (DAC) assay that captures plasma antibodies followed by affinity purification of lung proteins coupled to mass spectrometry. We analyzed antibody capture in two independent cohorts of IPF and CTL-ILD patients over two disease progression time points. Our findings revealed significant upregulation of specific immunoglobulins with V-segment bias in IPF across multiple cohorts. We identified a predictive autoimmune signature linked to reduced transplant-free survival in IPF, persisting over time. Notably, autoantibodies against thrombospondin-1 were associated with decreased survival, suggesting their potential as predictive biomarkers.

PMID:38026226 | PMC:PMC10661358 | DOI:10.1016/j.isci.2023.108345

Categories: Literature Watch

Real-world practice of idiopathic pulmonary fibrosis: Results from a 2000-2016 cohort

Wed, 2023-11-29 06:00

Open Med (Wars). 2023 Nov 11;18(1):20230852. doi: 10.1515/med-2023-0852. eCollection 2023.

ABSTRACT

The study aimed to investigate comorbidities, major adverse respiratory events, and mortality in patients with idiopathic pulmonary fibrosis (IPF). We established an IPF cohort and a comparative cohort matched for sex, age, and the date of IPF diagnosis. We recorded the most frequent comorbidities, the proportions, and time durations to the episode of major adverse respiratory events and death. Both cohorts were followed up to the end of 2016. We included 921 patients in the IPF cohort and 3,677 individuals in the comparative cohort. Comorbidities associated with IPF included pulmonary hypertension, chronic obstructive pulmonary disease, heart failure, asthma, and gastroesophageal reflux disease. The IPF cohort was more likely to have pneumonia (47.6 vs 12.0%), acute respiratory failure (17.8 vs 4.30%), chronic respiratory failure (4.23 vs 0.63%), and death (36.3 vs 15.0%) than the comparative cohort. The time durations to the first episode of pneumonia, acute respiratory failure, chronic respiratory failure, and death were 2.09 ± 2.98, 3.12 ± 3.62, 3.20 ± 4.03, and 3.27 ± 3.03 years in the IPF cohort. In conclusion, patients with IPF had significant comorbidities, particularly pulmonary and cardiovascular comorbidities. The duration from diagnosis to the major adverse respiratory events or death was short.

PMID:38025536 | PMC:PMC10655681 | DOI:10.1515/med-2023-0852

Categories: Literature Watch

Unraveling FOXO3a and USP18 Functions in Idiopathic Pulmonary Fibrosis through Single-Cell RNA Sequencing of Mouse and Human Lungs

Wed, 2023-11-29 06:00

Glob Med Genet. 2023 Nov 15;10(4):301-310. doi: 10.1055/s-0043-1776697. eCollection 2023 Dec.

ABSTRACT

Background Idiopathic pulmonary fibrosis (IPF) is identified as a chronic, progressive lung disease, predominantly marked by enhanced fibroblast proliferation and excessive deposition of extracellular matrix. The intricate interactions between diverse molecular pathways in fibroblasts play a crucial role in driving the pathogenesis of IPF. Methods This research is focused on elucidating the roles of FOXO3a, a transcription factor, and USP18, a ubiquitin-specific protease, in modulating fibroblast functionality in the context of IPF. FOXO3a is well-known for its regulatory effects on cellular responses, including apoptosis and oxidative stress, while USP18 is generally associated with protein deubiquitination. Results Our findings highlight that FOXO3a acts as a critical regulator in controlling fibroblast activation and differentiation, illustrating its vital role in the pathology of IPF. Conversely, USP18 seems to promote fibroblast proliferation and imparts resistance to apoptosis, thereby contributing to the exacerbation of fibrotic processes. The synergistic dysregulation of both FOXO3a and USP18 in fibroblasts was found to significantly contribute to the fibrotic alterations characteristic of IPF. Conclusion Deciphering the complex molecular interactions between FOXO3a and USP18 in fibroblasts provides a deeper understanding of IPF pathogenesis and unveils novel therapeutic avenues, offering a promising potential for not just halting but potentially reversing the progression of this debilitating disease.

PMID:38025194 | PMC:PMC10651367 | DOI:10.1055/s-0043-1776697

Categories: Literature Watch

A Curious Case of Biopsy-Proven Usual Interstitial Pneumonia

Wed, 2023-11-29 06:00

Cureus. 2023 Oct 25;15(10):e47661. doi: 10.7759/cureus.47661. eCollection 2023 Oct.

ABSTRACT

Usual interstitial pneumonia (UIP) refers to a combination of radiologic and histologic findings, which include patchy interstitial fibrosis with fibroblastic foci and dense acellular collagen that causes architectural distortion due to scarring and honeycomb change with alternating areas of normal lungs. The UIP pattern is not a synonymous term with idiopathic pulmonary fibrosis (IPF). IPF is diagnosed when an etiologic workup has been performed, deemed to be unrevealing, with a radiologic or histologic UIP pattern. While the 2018 American Thoracic Society (ATS)/European Respiratory Society (ERS) guideline categories of UIP help eliminate the need for surgical lung biopsy (SLB) in two categories, i.e., "definite UIP" and "probable UIP," when characterizing a patient in the other categories, clinicians should wary about prolonging SLB in patients to determine the fibrosis pattern. Changes in the treatment and overall prognosis of patients can occur due to SLB confirming a UIP pattern on histology. Here, we report the case of a patient with an indeterminate UIP pattern on high-resolution computed tomography (HRCT) with histopathologic diagnosis of UIP on SLB. With no underlying identifiable cause for the UIP pattern, the patient was diagnosed and managed as IPF, ultimately requiring lung transplantation. This case highlights the importance of pursuing surgical lung biopsy in patients with indeterminate UIP on HRCT scanning to facilitate prompt treatment and guide further management.

PMID:38021541 | PMC:PMC10667951 | DOI:10.7759/cureus.47661

Categories: Literature Watch

Idiopathic interstitial pneumonia in a patient with von Hippel-Lindau syndrome: a first case

Wed, 2023-11-29 06:00

ERJ Open Res. 2023 Nov 27;9(6):00504-2023. doi: 10.1183/23120541.00504-2023. eCollection 2023 Nov.

ABSTRACT

Although the mechanisms are not known, this is a case of progressive interstitial lung involvement, with a NSIP radiological pattern, evolving in pulmonary fibrosis in a patient with von Hippel-Lindau syndrome, without extrapulmonary fibrosis. https://bit.ly/3QlNStu.

PMID:38020566 | PMC:PMC10680027 | DOI:10.1183/23120541.00504-2023

Categories: Literature Watch

Editorial: Immune-mediated lung injury

Wed, 2023-11-29 06:00

Front Med (Lausanne). 2023 Nov 3;10:1292074. doi: 10.3389/fmed.2023.1292074. eCollection 2023.

NO ABSTRACT

PMID:38020172 | PMC:PMC10655232 | DOI:10.3389/fmed.2023.1292074

Categories: Literature Watch

Ambient Ultrafine Particulate Matter and Clinical Outcomes in Fibrotic Interstitial Lung Disease

Wed, 2023-11-29 06:00

Am J Respir Crit Care Med. 2023 Nov 29. doi: 10.1164/rccm.202307-1275OC. Online ahead of print.

ABSTRACT

RATIONALE: Particulate matter ≤2.5μm (PM2.5) is associated with adverse outcomes in fibrotic interstitial lung disease (fILD), but the impact of ultrafine particulates (UFPs; aerodynamic diameter ≤100nm) remains unknown.

OBJECTIVE: To evaluate UFP associations with clinical outcomes in fILD.

METHODS: Multicenter, prospective cohort study enrolling patients with fILD from the University of Pittsburgh Simmons Center and Pulmonary Fibrosis Foundation Patient Registry (PFF-PR). Using a national-scale UFP model, we linked exposures using three approaches in Simmons (residential address geocoordinates, zip centroid geocoordinates, zip average) and two in PFF-PR where only 5-digit zip code was available (zip centroid, zip average). We tested UFP associations with transplant-free survival using multivariable Cox, baseline percent predicted forced vital capacity (FVC) and diffusion capacity of the lung (DLCO) using multivariable linear regressions, and decline in FVC and DLCO using linear mixed models, adjusting for age, sex, smoking, race, socioeconomic status, site, PM2.5, and nitrogen dioxide.

RESULTS: Annual mean outdoor UFP levels for 2017 were estimated for 1416 Simmons and 1919 PFF-PR patients. Increased UFP level was associated with transplant-free survival in fully-adjusted Simmons residential address models (HR=1.08 per 1000 particles/cm3, 95%CI 1.01-1.15, p=0.02), but not PFF-PR models, which used less precise linkage approaches. Higher UFP was associated with lower baseline FVC and more rapid FVC decline in Simmons.

CONCLUSIONS: Increased UFP exposure was associated with transplant-free survival and lung function in the cohort with precise residential location linkage. This work highlights the need for more robust regulatory networks to study the health effects of UFPs nationwide.

PMID:38019094 | DOI:10.1164/rccm.202307-1275OC

Categories: Literature Watch

Idiopathic pulmonary fibrosis: Addressing the current and future therapeutic advances along with the role of Sotatercept in the management of pulmonary hypertension

Wed, 2023-11-29 06:00

Immun Inflamm Dis. 2023 Nov;11(11):e1079. doi: 10.1002/iid3.1079.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive and debilitating lung disease characterized by irreversible scarring of the lungs. The cause of IPF is unknown, but it is thought to involve a combination of genetic and environmental factors. There is no cure for IPF, and treatment is focused on slowing disease progression and relieving symptoms.

AIMS: We aimed in this review to investigate and provide the latest insights into IPF management modalities, including the potential of Saracatinibas a substitute for current IPF drugs. We also investigated the therapeutic potential of Sotatercept in addressing pulmonary hypertension associated with IPF.

MATERIALS AND METHODS: We conducted a comprehensive literature review of relevant studies on IPF management. We searched electronic databases, including PubMed, Scopus, Embase, and Web of science.

RESULTS: The two Food and Drug Administration-approved drugs for IPF, Pirfenidone, and Nintedanib, have been pivotal in slowing disease progression, yet experimental evidence suggests that Saracatinib surpasses their efficacy. Preclinical trials investigating the potential of Saracatinib, a tyrosine kinase inhibitor, have shown to be more effective than current IPF drugs in slowing disease progression in preclinical studies. Also, Sotatercept,a fusion protein, has been shown to reduce pulmonary vascular resistance and improve exercise tolerance in patients with PH associated with IPF in clinical trials.

CONCLUSIONS: The advancements discussed in this review hold the promise of improving the quality of life for IPF patients and enhancing our understanding of this condition. There remains a need for further research to confirm the efficacy and safety of new IPF treatments and to develop more effective strategies for managing exacerbations.

PMID:38018591 | DOI:10.1002/iid3.1079

Categories: Literature Watch

Evaluation of common protein biomarkers involved in the pathogenesis of respiratory diseases with proteomic methods: A systematic review

Wed, 2023-11-29 06:00

Immun Inflamm Dis. 2023 Nov;11(11):e1090. doi: 10.1002/iid3.1090.

ABSTRACT

AIM: Respiratory disease (RD) is one of the most common diseases characterized by lung dysfunction. Many diagnostic mechanisms have been used to identify the pathogenic agents of responsible for RD. Among these, proteomics emerges as a valuable diagnostic method for pinpointing the specific proteins involved in RD pathogenesis. Therefore, in this study, for the first time, we examined the protein markers involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), asthma, bronchiolitis obliterans (BO), and chemical warfare victims exposed to mustard gas, using the proteomics method as a systematic study.

MATERIALS AND METHODS: A systematic search was performed up to September 2023 on several databases, including PubMed, Scopus, ISI Web of Science, and Cochrane. In total, selected 4246 articles were for evaluation according to the criteria. Finally, 119 studies were selected for this systematic review.

RESULTS: A total of 13,806 proteins were identified, 6471 in COPD, 1603 in Asthma, 5638 in IPF, three in BO, and 91 in mustard gas exposed victims. Alterations in the expression of these proteins were observed in the respective diseases. After evaluation, the results showed that 31 proteins were found to be shared among all five diseases.

CONCLUSION: Although these 31 proteins regulate different factors and molecular pathways in all five diseases, they ultimately lead to the regulation of inflammatory pathways. In other words, the expression of some proteins in COPD and mustard-exposed patients increases inflammatory reactions, while in IPF, they cause lung fibrosis. Asthma, causes allergic reactions due to T-cell differentiation toward Th2.

PMID:38018577 | DOI:10.1002/iid3.1090

Categories: Literature Watch

Itaconate as a key regulator of respiratory disease

Wed, 2023-11-29 06:00

Clin Exp Immunol. 2023 Nov 29:uxad127. doi: 10.1093/cei/uxad127. Online ahead of print.

ABSTRACT

Macrophage activation results in the accumulation of endogenous metabolites capable of adopting immunomodulatory roles; one such bioactive metabolite is itaconate. After macrophage stimulation, the TCA-cycle intermediate cis-aconitate is converted to itaconate (by aconitate decarboxylase-1, ACOD1) in the mitochondrial matrix. Recent studies have highlighted the potential of targeting itaconate as a therapeutic strategy for lung diseases such as asthma, idiopathic pulmonary fibrosis (IPF), and respiratory infections. This review aims to bring together evidence which highlights a role for itaconate in chronic lung diseases (such as asthma and pulmonary fibrosis) and respiratory infections (such as SARS-CoV-2, influenza and Mycobacterium tuberculosis infection). A better understanding of the role of itaconate in lung disease could pave the way for novel therapeutic interventions and improve patient outcomes in respiratory disorders.

PMID:38018224 | DOI:10.1093/cei/uxad127

Categories: Literature Watch

Induced pluripotent stem cells modulate the Wnt pathway in the bleomycin-induced model of idiopathic pulmonary fibrosis

Wed, 2023-11-29 06:00

Stem Cell Res Ther. 2023 Nov 28;14(1):343. doi: 10.1186/s13287-023-03581-4.

ABSTRACT

BACKGROUND: The Wnt signaling pathway has been implicated in the pathogenesis of fibrotic disorders and malignancies. Hence, we aimed to assess the potential of the induced pluripotent stem cells (IPS) in modulating the expression of the cardinal genes of the Wnt pathway in a mouse model of idiopathic pulmonary fibrosis (IPF).

METHODS: C57Bl/6 mice were randomly divided into three groups of Control, Bleomycin (BLM), and BLM + IPS; the BLM mice received intratracheal instillation of bleomycin, BLM + IPS mice received tail vein injection of IPS cells 48 h post instillation of the BLM; The Control group received Phosphate-buffered saline instead. After 3 weeks, the mice were sacrificed and Histologic assessments including hydroxy proline assay, Hematoxylin and Eosin, and Masson-trichrome staining were performed. The expression of the genes for Wnt, β-Catenin, Lef, Dkk1, and Bmp4 was assessed utilizing specific primers and SYBR green master mix.

RESULTS: Histologic assessments revealed that the fibrotic lesions and inflammation were significantly alleviated in the BLM + IPS group. Besides, the gene expression analyses demonstrated the upregulation of Wnt, β-Catenin, and LEF along with the significant downregulation of the Bmp4 and DKK1 in response to bleomycin treatment; subsequently, it was found that the treatment of the IPF mice with IPS cells results in the downregulation of the Wnt, β-Catenin, and Lef, as well as upregulation of the Dkk1, but not the Bmp4 gene (P values < 0.05).

CONCLUSION: The current study highlights the therapeutic potential of the IPS cells on the IPF mouse model in terms of regulating the aberrant expression of the factors contributing to the Wnt signaling pathway.

PMID:38017561 | DOI:10.1186/s13287-023-03581-4

Categories: Literature Watch

A case report: Acute fibrinous and organizing pneumonia

Tue, 2023-11-28 06:00

Medicine (Baltimore). 2023 Nov 24;102(47):e36093. doi: 10.1097/MD.0000000000036093.

ABSTRACT

RATIONALE: Acute fibrinous and organizing pneumonia (AFOP) is a rare acute or subacute interstitial lung disorder characterized by the deposition of fibrin within the alveoli and organizing pneumonia with a patchy distribution. The clinical features of AFOP are nonspecific, and it is often misdiagnosed as pneumonia, cancer, tuberculosis, or other lung disorders.

PATIENT CONCERNS: In this case report, a 58-year-old woman presented with chest tightness, shortness of breath, cough and sputum. A chest CT scan showed multiple patchy shadows in both lungs. She was initially diagnosed with community-acquired pneumonia. Her purified protein derivative skin test was positive, but sputum was negative for acid-fast bacilli.

DIAGNOSES: AFOP was diagnosed by bronchoscopic lung biopsy and histopathology.

INTERVENTIONS: Following AFOP diagnosis, all anti-infective drugs were discontinued, and replaced by methylprednisolone and prednisone.

OUTCOMES: After 1 week of treatment with methylprednisolone 40 mg daily, the patient chest CT and clinical symptoms improved. After 1 month, the patient symptoms had demonstrated dramatic improvement and CT scan revealed complete absorption of lesions in both lungs. After 5 months of follow-up, the patient symptoms completely disappeared.

LESSONS: Acute AFOP is an uncommon lung condition with poor prognosis; hence, early diagnosis and identification are particularly important. Definitive diagnosis requires histopathological findings. Currently, there is no unified treatment guideline for AFOP, and treatment must be tailored based on the etiology and severity of each individual patient disease. Subacute AFOP shows a good response to corticosteroid treatment.

PMID:38013287 | DOI:10.1097/MD.0000000000036093

Categories: Literature Watch

Mendelian randomization reveals no correlations between herpesvirus infection and idiopathic pulmonary fibrosis

Tue, 2023-11-28 06:00

PLoS One. 2023 Nov 28;18(11):e0295082. doi: 10.1371/journal.pone.0295082. eCollection 2023.

ABSTRACT

BACKGROUND: Previous studies have found that the persistence of herpesvirus significantly increases the risk of idiopathic pulmonary fibrosis (IPF), but it is unclear whether this effect is causal. We conducted a two-sample Mendelian randomization (MR) study to evaluate the causal relationship between three herpesvirus infections and IPF.

METHODS: We used genome-wide association studies (GWAS) data from three independent datasets, including FinnGen cohort, Milieu Intérieur cohort, and 23andMe cohort, to screen for instrumental variables (IVs) of herpesvirus infection or herpesvirus-related immunoglobulin G (IgG) levels. Outcome dataset came from the largest meta-analysis of IPF susceptibility currently available.

RESULTS: In the FinnGen cohort, genetically predicted Epstein-Barr virus (EBV) (OR = 1.105, 95%CI: 0.897-1.149, p = 0.815), cytomegalovirus (CMV) (OR = 1.073, 95%CI: 0.926-1.244, p = 0.302) and herpes simplex (HSV) infection (OR = 0.906, 95%CI: 0.753-1.097, p = 0.298) were not associated with the risk of IPF. In the Milieu Intérieur cohort, we found no correlations between herpesvirus-related IgG EBV nuclear antigen-1 (EBNA1) (OR = 0.968, 95%CI: 0.782-1.198, p = 0.764), EBV viral capsid antigen (VCA) (OR = 1.061, 95CI%: 0.811-1.387, p = 0.665), CMV (OR = 1.108, 95CI%: 0.944-1.314, p = 0.240), HSV-1 (OR = 1.154, 95%CI: 0.684-1.945, p = 0.592) and HSV-2 (OR = 0.915, 95%CI: 0.793-1.056, p = 0.225) and IPF risk. Moreover, in the 23andMe cohort, no evidence of associations between mononucleosis (OR = 1.042, 95%CI: 0.709-1.532, p = 0.832) and cold scores (OR = 0.906, 95%CI: 0.603-1.362, p = 0.635) and IPF were found. Sensitivity analysis confirmed the robustness of our results.

CONCLUSIONS: This study provides preliminary evidence that EBV, CMV, and HSV herpesviruses, and herpesviruses-related IgG levels, are not causally linked to IPF. Further MR analysis will be necessary when stronger instrument variables and GWAS with larger sample sizes become available.

PMID:38015883 | DOI:10.1371/journal.pone.0295082

Categories: Literature Watch

Modeling Molecular Pathogenesis of Idiopathic Pulmonary Fibrosis-Associated Lung Cancer in Mice

Tue, 2023-11-28 06:00

Mol Cancer Res. 2023 Nov 28. doi: 10.1158/1541-7786.MCR-23-0480. Online ahead of print.

ABSTRACT

Idiopathic Pulmonary Fibrosis (IPF) is characterized by progressive, often fatal loss of lung function due to overactive collagen production and tissue scarring. IPF patients have a sevenfold-increased risk of developing lung cancer. The COVID-19 pandemic has increased the number of patients with lung diseases, and infection can worsen prognoses for those with chronic lung diseases and disease-associated cancer. Understanding the molecular pathogenesis of IPF associated lung cancer is imperative for identifying diagnostic biomarkers and targeted therapies that will facilitate prevention of IPF and progression to lung cancer. To understand how IPF-associated fibroblast activation, matrix remodeling, epithelial- mesenchymal transition, and immune modulation influences lung cancer predisposition, we developed a mouse model to recapitulate the molecular pathogenesis of pulmonary fibrosis-associated lung cancer using the bleomycin and Lewis Lung Carcinoma models. We demonstrate that development of pulmonary fibrosis-associated lung cancer is likely linked to increased abundance of tumor-associated macrophages and a unique gene signature that supports an immune-suppressive microenvironment through secreted factors. Not surprisingly, pre-existing fibrosis provides a pre-metastatic niche and results in augmented tumor growth, and tumors associated with bleomycin-induced fibrosis are characterized by a dramatic loss of cytokeratin expression, indicative of epithelial-to-mesenchymal transition. Implications: This characterization of tumors associated with lung diseases provides new therapeutic targets that may aid in the development of treatment paradigms for lung cancer patients with pre-existing pulmonary diseases. .

PMID:38015750 | DOI:10.1158/1541-7786.MCR-23-0480

Categories: Literature Watch

Inhibition of Galectin-1 attenuates lung fibroblast activation and proliferation in lung fibrosis

Tue, 2023-11-28 06:00

Cell Mol Biol (Noisy-le-grand). 2023 Nov 15;69(11):213-218. doi: 10.14715/cmb/2023.69.11.32.

ABSTRACT

The purpose of this study was to investigate the parenchymal changes in idiopathic pulmonary fibrosis (IPF) caused by massive fibroblastic infiltration and proliferation in lung tissue. Galectin-1 (Gal-1) has been reported to be involved in angiogenesis and fibrosis via modification of TGF-b receptor signaling pathways. However, it remains unknown whether Galectin-1 plays a critical role in IPF. In the current study, we aimed to identify Gal-1 as a crucial fibrotic protein in IPF process. Murine lung fibroblast was pre-treated using Gal-1 inhibitor OTX-008 or overexpression of Gal-1 and then activated using transforming growth factor-beta (TGF-β). Adult male C57BL/6J mice were conducted intratracheal injection of bleomycin (BLM) for lung fibrosis. Mice were conducted OTX-008 administration. Gal-1 expression, fibroblast activation and proliferation, extracellular matrix (ECM), lung fibrosis, lung histology and pulmonary function were investigated respectively. We demonstrated that Gal-1, as a positive pro-fibrotic marker, could promote lung fibroblast activation and proliferation. Inhibition of Gal-1 reduced fibroblast activation and proliferation through negative regulation of TGF-β/Erk1/2 and AKT pathway. In vivo, Gal-1 inhibition ameliorates lung fibroblast accumulation and protects lung histology and function. Gal-1 is verified to be a pro-fibrotic gene in IPF pathogenesis, which promotes fibroblast activation and proliferation via TGF-β/Erk1/2 and AKT pathway. Moreover, inhibition of Gal-1 in lung fibrosis model attenuates lung fibroblast bioactivity and reduces ECM, leading to improved pulmonary histology and function. Hence, knockdown of Gal-1 in IPF may be a promising target therapy.

PMID:38015516 | DOI:10.14715/cmb/2023.69.11.32

Categories: Literature Watch

A redox-shifted fibroblast subpopulation emerges in the fibrotic lung

Tue, 2023-11-28 06:00

bioRxiv. 2023 Sep 24:2023.09.23.559128. doi: 10.1101/2023.09.23.559128. Preprint.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is an aggressive and thus far incurable disease, characterized by aberrant fibroblast-mediated extracellular matrix deposition. Our understanding of the disease etiology is incomplete; however, there is consensus that a reduction-oxidation (redox) imbalance plays a role. In this study we use the autofluorescent properties of two redox molecules, NAD(P)H and FAD, to quantify changes in their relative abundance in living lung tissue of mice with experimental lung fibrosis, and in freshly isolated cells from mouse lungs and humans with IPF. Our results identify cell population-specific intracellular redox changes in the lungs in experimental and human fibrosis. We focus particularly on redox changes within collagen producing cells, where we identified a bimodal distribution of NAD(P)H concentrations, establishing NAD(P)H high and NAD(P)H low sub-populations. NAD(P)H high fibroblasts exhibited elevated pro-fibrotic gene expression and decreased collagenolytic protease activity relative to NAD(P)H low fibroblasts. The NAD(P)H high population was present in healthy lungs but expanded with time after bleomycin injury suggesting a potential role in fibrosis progression. We identified a similar increased abundance of NAD(P)H high cells in freshly dissociated lungs of subjects with IPF relative to controls, and similar reductions in collagenolytic activity in this cell population. These data highlight the complexity of redox state changes in experimental and human pulmonary fibrosis and the need for selective approaches to restore redox imbalances in the fibrotic lung.

PMID:38014129 | PMC:PMC10680805 | DOI:10.1101/2023.09.23.559128

Categories: Literature Watch

In vitro co-culture studies and the crucial role of fibroblast-immune cell crosstalk in IPF pathogenesis

Tue, 2023-11-28 06:00

Respir Res. 2023 Nov 27;24(1):298. doi: 10.1186/s12931-023-02608-x.

ABSTRACT

IPF is a fatal lung disease characterized by intensive remodeling of lung tissue leading to respiratory failure. The remodeling in IPF lungs is largely characterized by uncontrolled fibrosis. Fibroblasts and their contractile phenotype the myofibroblast are the main cell types responsible for typical wound healing responses, however in IPF, these responses are aberrant and result in the overactivation of fibroblasts which contributes to the inelasticity of the lung leading to a decrease in lung function. The specific mechanisms behind IPF pathogenesis have been elusive, but recently the innate and adaptive immunity have been implicated in the fibrotic processes of the disease. In connection with this, several in vitro co-culture models have been used to investigate the specific interactions occurring between fibroblasts and immune cells and how this contributes to the pathobiology of IPF. In this review, we discuss the in vitro models that have been used to examine the abnormal interactions between fibroblasts and cells of the innate and adaptive immune system, and how these contribute to the fibrotic processes in the lungs of IPF patients.

PMID:38012580 | DOI:10.1186/s12931-023-02608-x

Categories: Literature Watch

Cellular Senescence: A Troy Horse in Pulmonary Fibrosis

Sat, 2023-11-25 06:00

Int J Mol Sci. 2023 Nov 16;24(22):16410. doi: 10.3390/ijms242216410.

ABSTRACT

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by myofibroblast abnormal activation and extracellular matrix deposition. However, the pathogenesis of PF remains unclear, and treatment options are limited. Epidemiological studies have shown that the average age of PF patients is estimated to be over 65 years, and the incidence of the disease increases with age. Therefore, PF is considered an age-related disease. A preliminary study on PF patients demonstrated that the combination therapy of the anti-senescence drugs dasatinib and quercetin improved physical functional indicators. Given the global aging population and the role of cellular senescence in tissue and organ aging, understanding the impact of cellular senescence on PF is of growing interest. This article systematically summarizes the causes and signaling pathways of cellular senescence in PF. It also objectively analyzes the impact of senescence in AECs and fibroblasts on PF development. Furthermore, potential intervention methods targeting cellular senescence in PF treatment are discussed. This review not only provides a strong theoretical foundation for understanding and manipulating cellular senescence, developing new therapies to improve age-related diseases, and extending a healthy lifespan but also offers hope for reversing the toxicity caused by the massive accumulation of senescence cells in humans.

PMID:38003600 | PMC:PMC10671822 | DOI:10.3390/ijms242216410

Categories: Literature Watch

Animal models of acute exacerbation of pulmonary fibrosis

Sat, 2023-11-25 06:00

Respir Res. 2023 Nov 25;24(1):296. doi: 10.1186/s12931-023-02595-z.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive scarring interstitial lung disease with an unknown cause. Some patients may experience acute exacerbations (AE), which result in severe lung damage visible on imaging or through examination of tissue samples, often leading to high mortality rates. However, the etiology and pathogenesis of AE-IPF remain unclear. AE-IPF patients exhibit diffuse lung damage, apoptosis of type II alveolar epithelial cells, and an excessive inflammatory response. Establishing a reliable animal model of AE is critical for investigating the pathogenesis. Recent studies have reported a variety of animal models for AE-IPF, each with its own advantages and disadvantages. These models are usually established in mice with bleomycin-induced pulmonary fibrosis, using viruses, bacteria, small peptides, or specific drugs. In this review, we present an overview of different AE models, hoping to provide a useful resource for exploring the mechanisms and targeted therapies for AE-IPF.

PMID:38007420 | DOI:10.1186/s12931-023-02595-z

Categories: Literature Watch

FGF18

Sat, 2023-11-25 06:00

Differentiation. 2023 Nov 7:100735. doi: 10.1016/j.diff.2023.10.003. Online ahead of print.

ABSTRACT

FGF18 was discovered in 1998. It is a pleiotropic growth factor that stimulates major signalling pathways involved in cell proliferation and growth, and is involved in the development and homeostasis of many tissues such as bone, lung, and central nervous system. The gene consists of five exons that code for a 207 amino acid glycosylated protein. FGF18 is widely expressed in developing and adult chickens, mice, and humans, being seen in the mesenchyme, brain, skeleton, heart, and lungs. Knockout studies of FGF18 in mice lead to perinatal death, characterised by distinct phenotypes such as cleft palate, smaller body size, curved long bones, deformed ribs, and reduced crania. As can be expected from a protein involved in so many functions FGF18 is associated with various diseases such as idiopathic pulmonary fibrosis, congenital diaphragmatic hernia, and most notably various types of cancer such as breast, lung, and ovarian cancer.

PMID:38007374 | DOI:10.1016/j.diff.2023.10.003

Categories: Literature Watch

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