Ann Am Thorac Soc. 2023 Dec 14. doi: 10.1513/AnnalsATS.202305-495RL. Online ahead of print.

NO ABSTRACT

PMID:38096447 | DOI:10.1513/AnnalsATS.202305-495RL

Ann Am Thorac Soc. 2023 Dec 14. doi: 10.1513/AnnalsATS.202305-402OC. Online ahead of print.

ABSTRACT

Rationale Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic pulmonary disorder of unknown etiology, characterized by a usual interstitial pneumonia (UIP) pattern. Previous meta-analyses have reported associations between occupational exposures and IPF, but higher-quality studies have been published in recent years, doubling the number of studied patients. Objective To provide a contemporary and comprehensive assessment of the relationship between occupational exposures and IPF. Study Design and Methods We searched Pubmed, Embase, and Web of Science through July 2023 to identify all publications on occupational exposure and IPF. We conducted a meta-analysis of the occupational burden, odds ratio (OR), and population attributable fraction (PAF) of exposures. Five exposure categories were analyzed: VGDF (vapors, gas, dust, and fumes), metal dust, wood dust, silica dust, and agricultural dust. A comprehensive bias assessment was performed. The study protocol was registered to the International Prospective Register of Systematic Reviews (ID: CRD42021267808). Results Our search identified 23,942 publications. Sixteen publications contained relative risks needed to calculate pooled ORs and PAFs, and 12 additional publications reported an occupational burden within a case series. The proportion of cases with occupational exposures to VGDF was 44% [95% confidence interval (CI), 36-53], with a range of 8-17% within more specific exposure categories. The pooled OR was elevated for VGDF at 1.8 (CI, 1.3-2.4), with a pooled PAF of 21% (CI, 15-28). The OR and PAF were respectively found to be 1.6 and 7% (metal dust), 1.6 and 3% (wood dust), 1.8 and 14% (agricultural dust), and 1.8 and 4% (silica dust). The pooled OR and PAF within specific exposure categories ranged from 1.6-1.8 and 4-14%, respectively. We identified some publication bias, though it was not sufficient to diminish the association between occupational exposures and IPF based on sensitivity analysis and bias assessment. Conclusions Our findings indicate that 21% (or approximately 1 in 5) IPF cases could be prevented by removal of occupational exposure (alongside a pooled OR of 1.8). Additionally, 44% of patients with IPF report occupational exposure to VGDF. This meta-analysis suggests that a considerable number of cases of IPF are attributable to inhaled occupational exposures and warrant increased consideration in the clinical care of patients and future prevention efforts. Clinical Trials Registration International Prospective Register of Systematic Reviews (ID: CRD42021267808).

PMID:38096107 | DOI:10.1513/AnnalsATS.202305-402OC

Front Immunol. 2023 Nov 29;14:1290585. doi: 10.3389/fimmu.2023.1290585. eCollection 2023.

ABSTRACT

INTRODUCTION: MZB1 is an endoplasmic reticulum residential protein preferentially expressed in plasma cells, marginal zone and B1 B cells. Recent studies on murine B cells show that it interacts with the tail piece of IgM and IgA heavy chain and promotes the secretion of these two classes of immunoglobulin. However, its role in primary human B cells has yet to be determined and how its function is regulated is still unknown. The conversion of peptidylarginine to peptidylcitrulline, also known as citrullination, by peptidylarginine deiminases (PADs) can critically influence the function of proteins in immune cells, such as neutrophils and T cells; however, the role of PADs in B cells remains to be elucidated.

METHOD: An unbiased analysis of human lung citrullinome was conducted to identify citrullinated proteins that are enriched in several chronic lung diseases, including rheumatoid arthritis-associated interstitial lung disease (RA-ILD), chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis, compared to healthy controls. Mass spectrometry, site-specific mutagenesis, and western blotting were used to confirm the citrullination of candidate proteins. Their citrullination was suppressed by pharmacological inhibition or genetic ablation of PAD2 and the impact of their citrullination on the function and differentiation of human B cells was examined with enzyme-linked immunosorbent assay, flow cytometry, and co-immunoprecipitation.

RESULTS: Citrullinated MZB1 was preferentially enriched in RA-ILD but not in other chronic lung diseases. MZB1 was a substrate of PAD2 and was citrullinated during the differentiation of human plasmablasts. Ablation or pharmacological inhibition of PAD2 in primary human B cells attenuated the secretion of IgM and IgA but not IgG or the differentiation of IgM or IgA-expressing plasmablasts, recapitulating the effect of ablating MZB1. Furthermore, the physical interaction between endogenous MZB1 and IgM/IgA was attenuated by pharmacological inhibition of PAD2.

DISCUSSION: Our data confirm the function of MZB1 in primary human plasmablasts and suggest that PAD2 promotes IgM/IgA secretion by citrullinating MZB1, thereby contributing to the pathogenesis of rheumatoid arthritis and RA-ILD.

PMID:38094295 | PMC:PMC10716219 | DOI:10.3389/fimmu.2023.1290585

J Thorac Dis. 2023 Nov 30;15(11):5913-5921. doi: 10.21037/jtd-23-946. Epub 2023 Oct 25.

ABSTRACT

BACKGROUND: The role of combination treatments with two antifibrotic agents, pirfenidone and nintedanib, has been not established in idiopathic pulmonary fibrosis (IPF). This study was performed to investigate the safety and tolerability of combination antifibrotic treatment in patients with IPF.

METHODS: We conducted a proportional meta-analysis and searched PubMed, EMBASE, and the Cochrane Central Register for relevant clinical trials. The primary outcome was the proportion of discontinuation of combination treatment over the treatment period. We also examined the pooled proportions of serious and any adverse drug reactions (ADRs).

RESULTS: Four clinical trials involving 191 patients were analyzed. In pooled estimates, 29% of patients discontinued treatment during the study period [95% confidence interval (CI): 17-41%, I2=65.42%]. The pooled proportions of serious and any ADRs were 10% (95% CI: 1-19%; I2=79.13%) and 82% (95% CI: 75-90%; I2=39.20%), respectively. During the follow-up period, gastrointestinal symptoms were the most frequent ADR. Acute exacerbation (AE) of IPF was reported in 7.0% of patients.

CONCLUSIONS: Our findings showed relatively frequent incidence of discontinuation and ADRs for combination therapy in IPF. Further large-scale, randomized, controlled trials are needed to support our results because of the methodological limitations of the included trials and a scarcity of trials for analysis.

PMID:38090320 | PMC:PMC10713318 | DOI:10.21037/jtd-23-946

J Thorac Dis. 2023 Nov 30;15(11):6160-6177. doi: 10.21037/jtd-23-815. Epub 2023 Nov 27.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic and fatal pulmonary interstitial disease that usually occurs in the elderly. The senescence of alveolar epithelial cells (AECs) is an important mechanism of IPF. The AECs of patients with IPF have lower expression of peroxisome proliferator-activated receptor-γ coactivator-1 alpha (PGC-1α), which has been shown to play an important role in maintaining mitochondrial morphology and energy metabolism. This study sought to explore the mechanism by which ZLN005 improves mitochondrial function by upregulating PGC-1α to protect AECs from aging.

METHODS: Western blot was used to detect the expression of PGC-1α, mitochondrial synthesis protein nuclear respiratory factor-1 (NRF-1), and p21WAF1 in the lung tissue of the IPF patients and the mice with bleomycin (BLM)-induced pulmonary fibrosis. A549 cells and mice AEC2 cells were treated with hydrogen peroxide (H2O2) to construct cell senescence models. Cell senescence was detected by senescence-associated beta-galactosidase staining. The mitochondrial respiratory function was measured, including the adenosine triphosphate (ATP) generation, reactive oxygen species (ROS) level, changes in cell membrane potential, and energy metabolism. Using lentivirus as a vector and using gene editing technology to over express (upPGC-1α) and knockdown PGC-1α (shPGC-1α) in the A549 cells. The PGC-1α agonist ZLN005 was used to pretreat the A549 and shPGC-1α A549 cells, and cell aging and mitochondrial respiratory function were observed.

RESULTS: The Western blot and immunofluorescence assays showed that the expression of PGC-1α and NRF-1 was decreased in the lung tissues of the IPF patients and BLM-induced mice pulmonary fibrosis model, while the expression of p21WAF1 was increased. The results of the immunofluorescence and mitochondrial function experiments also indicated that the expression of PGC-1α and mitochondrial synthesis protein NRF-1 were decreased in the senescent cells. Further, the mitochondrial morphology was abnormal and the mitochondrial function was impaired. PGC-1α was involved in the AEC senescence by regulating mitochondrial morphology and function. Treatment with the agonist of PGC-1α (i.e., ZLN005) blocked the H2O2-induced cell senescence by enhancing the expression of PGC-1α.

CONCLUSIONS: These results provide preliminary insights into the potential clinical application of ZLN005 as a novel therapeutic agent for the treatment of IPF.

PMID:38090292 | PMC:PMC10713321 | DOI:10.21037/jtd-23-815

Front Pharmacol. 2023 Nov 27;14:1324586. doi: 10.3389/fphar.2023.1324586. eCollection 2023.

NO ABSTRACT

PMID:38089050 | PMC:PMC10711599 | DOI:10.3389/fphar.2023.1324586

Respirology. 2023 Dec 12. doi: 10.1111/resp.14643. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVE: Corticosteroids are commonly used for the treatment of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF); however, the optimal initial dose of corticosteroids remains uncertain due to a lack of sufficient evidence. We evaluated whether the administration of a pulse dose of corticosteroids resulted in improved survival outcomes compared with conventional non-pulse dose of corticosteroids.

METHODS: We retrospectively analysed 238 patients with AE-IPF treated with corticosteroids at a tertiary referral hospital between January 2013 and December 2021. Based on whether a pulse dose of corticosteroids (methylprednisolone of ≥250 mg/day or equivalent) was administered within 7 days of hospitalization for AE-IPF, the patients were divided into the pulse and non-pulse regimen groups. The survival outcomes were compared between the two groups using multivariable regression and propensity score-matched analyses.

RESULTS: Among the 238 patients, 59 patients received pulse dose of corticosteroids, whereas 179 patients received conventional non-pulse dose of corticosteroids. After adjusting for the confounding factors related to the baseline clinical and radiographic severity, compared with the conventional non-pulse regimen, the pulse regimen of corticosteroids did not reduce the risk of mortality at the 3-month (aHR 0.84, 95% CI 0.45-1.38) or 12-month (aHR 0.96, 95% CI 0.60-1.25) follow-ups. Propensity score-matched analysis revealed similar results.

CONCLUSION: The survival outcomes of patients with AE-IPF who received a pulse dose of corticosteroids did not differ from those of patients who received conventional non-pulse dose of corticosteroids. Further prospective studies are required to establish the optimal initial dose of corticosteroids for the treatment of AE-IPF.

PMID:38087838 | DOI:10.1111/resp.14643

Int Immunopharmacol. 2023 Dec 11;127:111330. doi: 10.1016/j.intimp.2023.111330. Online ahead of print.

ABSTRACT

OBJECTIVES: Interstitial lung disease (ILD) is associated with significant mortality in rheumatoid arthritis (RA) patients with key cellular players remaining largely unknown. This study aimed to characterize inflammatory and myeloid derived suppressor cell (MDSC) subpopulations in RA-ILD as compared to RA, idiopathic pulmonary fibrosis (IPF) without autoimmunity, and controls.

METHODS: Peripheral blood was collected from patients with RA, RA-ILD, IPF, and controls (N = 60, 15/cohort). Myeloid cell subpopulations were identified phenotypically by flow cytometry using the following markers:CD45,CD3,CD19,CD56,CD11b,HLA-DR,CD14,CD16,CD15,CD125,CD33. Functionality of subsets were identified with intracellular arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS) expression.

RESULTS: There was increased intermediate (CD14++CD16+) and nonclassical (CD14+/-CD16++) and decreased classical (CD14++CD16-) monocytes in RA, RA-ILD, and IPF vs. control. Intermediate monocytes were higher and classical monocytes were lower in RA-ILD vs. RA but not IPF. Monocytic (m)MDSCs were higher in RA-ILD vs. control and RA but not IPF. Granulocytic (g)MDSCs did not significantly differ. In contrast, neutrophils were increased in IPF and RA-ILD patients with elevated expression of Arg-1 sharing similar dimensional clustering pattern. Eosinophils were increased in RA-ILD vs. controls, RA and IPF. Across cohorts, iNOS was decreased in intermediate/nonclassical monocytes but increased in mMDSCs vs. classical monocytes. In RA-ILD, iNOS positive mMDSCs were increased versus classic monocytes.

CONCLUSIONS: Myeloid cell subpopulations are significantly modulated in RA-ILD patients with expansion of CD16+ monocytes, mMDSCs, and neutrophils, a phenotypic profile more aligned with IPF than other RA patients. Eosinophil expansion was unique to RA-ILD, potentially facilitating disease pathogenesis and providing a future therapeutic target.

PMID:38086271 | DOI:10.1016/j.intimp.2023.111330

Rheumatol Int. 2023 Dec 12. doi: 10.1007/s00296-023-05505-0. Online ahead of print.

ABSTRACT

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a better prognosis compared to idiopathic pulmonary fibrosis (IPF). Recent data suggest that antifibrotics are effective in slowing progression across both groups. Hence, we designed this study to investigate the similarities and differences between these groups of patients. This is a retrospective cohort study examining baseline data, progression and outcomes in patients with RA-ILD and IPF prior to antifibrotic use in the Coventry ILD database. Ethics approval was obtained from the University Hospital Coventry and Warwickshire NHS Trust. Statistical analysis was performed using R software and Cox's proportional hazards technique was used for survival analysis. We identified 131 cases, including 49 patients with IPF, 34 patients with RA-ILD and 48 patients with other forms of idiopathic interstitial pneumonia. At baseline, there were significant differences in the groups with RA-ILD patients being significantly younger (65.7 vs 72.4 years), had preserved lung volumes (FVC 95% vs 84.7%) and higher gas transfer (61.5% vs 48.2%) compared to IPF patients. 5-year survival was better for RA-ILD compared to IPF (87.5% vs 40.4%, p = 0.0042). Univariate analysis revealed gas transfer, FVC, age, sex and phenotype (IPF or RA-ILD) were all significant predictors, but multivariate analysis revealed that gas transfer and age were both significantly associated with prognosis, whereas sex, FVC or phenotype were not significant. This study suggests that the difference between RA-ILD and IPF prognosis may be due to demographics and early diagnosis rather than the diseases behaving differently. This has important management implications.

PMID:38085367 | DOI:10.1007/s00296-023-05505-0

Am J Physiol Lung Cell Mol Physiol. 2023 Dec 12. doi: 10.1152/ajplung.00155.2023. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by progressive scarring of the lungs and resulting in deterioration in lung function. Transforming growth factor-beta (TGF-β) is one of the most established drivers of fibrotic processes. TGF-β promotes transformation of tissue fibroblasts to myofibroblasts, a key finding in the pathogenesis of pulmonary fibrosis. We report here that TGF-β robustly upregulates the expression of the calcium-activated chloride channel Anoctamin-1 (ANO1) in human lung fibroblasts (HLF) at mRNA and protein levels. ANO1 is readily detected in fibrotic areas of IPF lungs in the same area with smooth muscle alpha-actin (SMA)-positive myofibroblasts. TGF-β-induced myofibroblast differentiation (determined by the expression of SMA, collagen-1 and fibronectin) is significantly inhibited by a specific ANO1 inhibitor, T16Ainh-A01, or by siRNA-mediated ANO1 knockdown. T16Ainh-A01 and ANO1 siRNA attenuate pro-fibrotic TGF-β signaling, including activation of RhoA pathway and AKT, without affecting initial Smad2 phosphorylation. Mechanistically, TGF-β treatment of HLF results in a significant increase in intracellular chloride levels, which is prevented by T16Ainh-A01 or by ANO1 knockdown. The downstream mechanism involves the chloride-sensing "with-no-lysine (K)" kinase (WNK1). WNK1 siRNA significantly attenuates TGF-β-induced myofibroblast differentiation and signaling (RhoA pathway and AKT), whereas the WNK1 kinase inhibitor WNK463 is largely ineffective. Together, these data demonstrate that (i) ANO1 is a TGF-β-inducible chloride channel that contributes to increased intracellular chloride concentration in response to TGF-β; and (ii) ANO1 mediates TGF-β-induced myofibroblast differentiation and fibrotic signaling in a manner dependent on WNK1 protein, but independent of WNK1 kinase activity.

PMID:38084409 | DOI:10.1152/ajplung.00155.2023

Food Funct. 2023 Dec 12. doi: 10.1039/d3fo03464j. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease that leads to dyspnea and progressive loss of lung function. This study aimed to investigate the protective effect of betanin (BET), the major pigment in red beetroot, on pulmonary fibrosis induced by bleomycin (BLM) in rats and to assess the underlying mechanisms. In this view, total and differential cell counts and LDH activity in bronchoalveolar lavage fluid were estimated. Furthermore, MDA and GSH contents in the lungs were colorimetrically measured, while hydroxyproline, NLRP3, ASC, caspase-1, TGF-β1, and vimentin levels in lung tissue were evaluated using the ELISA technique. Moreover, IL-1β, E-cadherin, and α-SMA expressions were analyzed by immunostaining of lung specimens. BET treatment protects against pulmonary fibrosis as indicated by the reduction in total and differential cell counts, LDH activity, hydroxyproline, NLRP3, ASC, caspase-1, IL-1β, and TGF-β1 levels. MDA content was also decreased following BET administration, while GSH content was elevated. Additionally, BET suppressed the EMT process as evidenced by an increase in E-cadherin expression besides the reduction in vimentin and α-SMA expressions. To conclude, these results revealed the protective effect of BET against pulmonary fibrosis that might be attributed to the attenuation of the NLRP3/IL-1β/TGF-β1 signaling pathway and EMT process.

PMID:38083874 | DOI:10.1039/d3fo03464j

BMC Pulm Med. 2023 Dec 11;23(1):501. doi: 10.1186/s12890-023-02783-z.

ABSTRACT

Usual Interstitial Pneumonia (UIP) is characterized by progression of lung parenchyma that may be observed in various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis and connective tissue diseases. From a diagnostic point of view, a UIP pattern related to ARDs may display imaging and pathological features able to distinguish it from that related to IPF, such as the "straight-edge" sign at HRCT and lymphoplasmacytic infiltrates at histologic specimens. Multidisciplinary approach (MDD), involving at least pulmonologist, rheumatologist and radiologist, is fundamental in the differential diagnosis process, but MDD is also required in the evaluation of severity, progression and response to treatment, that is based on the combination of changes in symptoms, pulmonary function trends, and, in selected patients, serial CT evaluation. Differently from IPF, in patients with ARDs both functional evaluation and patient-reported outcomes may be affected by systemic involvement and comorbidities, including musculoskeletal manifestations of disease. Finally, in regards to pharmacological treatment, immunosuppressants have been considered the cornerstone of therapy, despite the lack of solid evidence in most cases; recently, antifibrotic drugs were also proposed for the treatment of progressive fibrosing ILDs other than IPF. In ARD-ILD, the therapeutic choice should balance the need for the control of systemic and lung involvements with the risk of adverse events from multi-morbidities and -therapies. Purpose of this review is to summarize the definition, the radiological and morphological features of the UIP pattern in ARDs, together with risk factors, diagnostic criteria, prognostic evaluation, monitoring and management approaches of the UIP-ARDs.

PMID:38082233 | PMC:PMC10714466 | DOI:10.1186/s12890-023-02783-z

Sci Rep. 2023 Dec 11;13(1):21981. doi: 10.1038/s41598-023-49281-0.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease characterized by complex lung pathogenesis affecting approximately three million people worldwide. While the molecular and cellular details of the IPF mechanism is emerging, our current understanding is centered around the lung itself. On the other hand, many human diseases are the products of complex multi-organ interactions. Hence, we postulate that a dysfunctional crosstalk of the lung with other organs plays a causative role in the onset, progression and/or complications of IPF. In this study, we employed a generative computational approach to identify such inter-organ mechanism of IPF. This approach found unexpected molecular relatedness of IPF to neoplasm, diabetes, Alzheimer's disease, obesity, atherosclerosis, and arteriosclerosis. Furthermore, as a potential mechanism underlying this relatedness, we uncovered a putative molecular crosstalk system across the lung and the liver. In this inter-organ system, a secreted protein, kininogen 1, from hepatocytes in the liver interacts with its receptor, bradykinin receptor B1 in the lung. This ligand-receptor interaction across the liver and the lung leads to the activation of calmodulin pathways in the lung, leading to the activation of interleukin 6 and phosphoenolpyruvate carboxykinase 1 pathway across these organs. Importantly, we retrospectively identified several pre-clinical and clinical evidence supporting this inter-organ mechanism of IPF. In conclusion, such feedforward and feedback loop system across the lung and the liver provides a unique opportunity for the development of the treatment and/or diagnosis of IPF. Furthermore, the result illustrates a generative computational framework for machine-mediated synthesis of mechanisms that facilitates and complements the traditional experimental approaches in biomedical sciences.

PMID:38081956 | DOI:10.1038/s41598-023-49281-0

BMJ Open Respir Res. 2023 Dec 11;10(1):e001763. doi: 10.1136/bmjresp-2023-001763.

ABSTRACT

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (iPPFE), a progressive fibrotic disease, is characterised by upper lobe-dominant lung fibrosis involving the pleura and subpleural lung parenchyma. However, no prognostic markers have been established for this condition. Associations between blood leucocyte levels and mortality have been reported in patients with idiopathic pulmonary fibrosis; therefore, we hypothesised that peripheral leucocyte levels are associated with mortality risk in patients with iPPFE.

METHODS: This retrospective study longitudinally assessed peripheral leucocyte counts at the time of diagnosis and 1 year after diagnosis in two cohorts of 127 patients with iPPFE (69 and 58 patients in Seirei and Hamamatsu cohorts, respectively).

RESULTS: A comprehensive assessment of peripheral leucocytes revealed that the neutrophil-lymphocyte ratio (NLR) was associated with mortality in patients with iPPFE after adjusting for age, sex and forced vital capacity in multivariate analyses (adjusted HR, 1.131; 95% CI, 1.032 to 1.227). When the patients were classified based on the median NLR, those with a high NLR had shorter survival than those with a low NLR (median, 32.2 vs 79.8 months; HR, 2.270; 95% CI, 1.416 to 3.696). Interestingly, the results of the NLR classification by median were longitudinally preserved in >70% of patients, and patients with consistently high NLR were at a higher risk of mortality than others (median, 24.8 vs 79.6 months; HR, 3.079; 95% CI, 1.878 to 5.031). Compared with the gender-age-physiology model, a composite model comprising age, sex and NLR could successfully stratify patients with iPPFE into three groups according to mortality risk.

CONCLUSION: The assessment of peripheral leucocyte counts is easy and might be useful in evaluating disease severity and mortality risk in patients with iPPFE. Our study suggests the importance of focusing on peripheral leucocyte levels in daily practice.

PMID:38081767 | DOI:10.1136/bmjresp-2023-001763

Res Sq. 2023 Nov 28:rs.3.rs-3587418. doi: 10.21203/rs.3.rs-3587418/v1. Preprint.

ABSTRACT

The long-term physiological consequences of SARS-CoV-2, termed Post-Acute Sequelae of COVID-19 (PASC), are rapidly evolving into a major public health concern. The underlying cellular and molecular etiology remain poorly defined but growing evidence links PASC to abnormal immune responses and/or poor organ recovery post-infection. Yet, the precise mechanisms driving non-resolving inflammation and impaired tissue repair in the context of PASC remain unclear. With insights from three independent clinical cohorts of PASC patients with abnormal lung function and/or viral infection-mediated pulmonary fibrosis, we established a clinically relevant mouse model of post-viral lung sequelae to investigate the pathophysiology of respiratory PASC. By employing a combination of spatial transcriptomics and imaging, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to the fibroproliferation in 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 Krt8hi transitional and ectopic Krt5+ basal cell progenitors, thus impairing alveolar regeneration and driving 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 and fibrosis. 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. Moreover, in contrast to other approaches requiring early intervention, we highlight therapeutic strategies to rescue fibrotic disease in the aftermath of respiratory viral infections, addressing the current unmet need in the clinical management of PASC and post-viral disease.

PMID:38077031 | PMC:PMC10705705 | DOI:10.21203/rs.3.rs-3587418/v1

Bioact Mater. 2023 Nov 22;33:262-278. doi: 10.1016/j.bioactmat.2023.11.005. eCollection 2024 Mar.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory and fibrotic response-driven lung disease that is difficult to cure because it manifests excessive profibrotic cytokines (e.g., TGF-β), activated myofibroblasts, and accumulated extracellular matrix (ECM). In an attempt to develop an inhalation formulation with enhanced antifibrotic efficacy, we sought to fabricate unique aerosolizable inhaled microgels (μGel) that contain nintedanib-poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs; n-PN) and pirfenidone-liposomes (p-LP). The aero-μGel was ∼12 μm, resisted phagocytosis by alveolar macrophages in vitro and in vivo, and protected inner-entrapped n-PN and p-LP. The n-PN/p-LP@aero-μGel caused enhanced/extended antifibrotic efficacy in a bleomycin-induced pulmonary fibrosis mouse presumably due to prolonged lung residence. Consequently, the results obtained by intratracheal aerosol insufflation of our n-PN/p-LP@aero-μGel twice a week were much better than those by as many as seven doses of single or mixed applications of n-PN or p-LP. The antifibrotic/pharmacokinetic results for the n-PN/p-LP@aero-μGel included reduced fibrosis progression, restored lung physiological functions, deactivated myofibroblasts, inhibited TGF-β progression, and suppressed ECM component production (collagen I and α-SMA) along with prolonged lung retention time. We believe that our n-PN/p-LP@aero-μGel increased the local availability of both nintedanib and pirfenidone due to evasion of alveolar macrophage phagocytosis and prolonged lung retention with reduced systemic distribution. Through this approach, our inhalation formulation subsequently attenuated fibrosis progression and improved lung function. Importantly, these results hold profound implications in the therapeutic potential of our n-PN/p-LP@aero-μGel to serve as a clinically promising platform, providing significant advancements for improved treatment of many respiratory diseases including IFP.

PMID:38076650 | PMC:PMC10708963 | DOI:10.1016/j.bioactmat.2023.11.005

Front Genet. 2023 Nov 24;14:1246983. doi: 10.3389/fgene.2023.1246983. eCollection 2023.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease that poses a significant challenge to medical professionals due to its increasing incidence and prevalence coupled with the limited understanding of its underlying molecular mechanisms. In this study, we employed a novel approach by integrating five expression datasets from bulk tissue with single-cell datasets; they underwent pseudotime trajectory analysis, switch gene selection, and cell communication analysis. Utilizing the prognostic information derived from the GSE47460 dataset, we identified 22 differentially expressed switch genes that were correlated with clinical indicators as important genes. Among these genes, we found that the midkine (MDK) gene has the potential to serve as a marker of Idiopathic pulmonary fibrosis because its cellular communicating genes are differentially expressed in the epithelial cells. We then utilized midkine and its cellular communication-related genes to calculate the midkine score. Machine learning models were further constructed through midkine and related genes to predict Idiopathic pulmonary fibrosis disease through the bulk gene expression datasets. The midkine score demonstrated a correlation with clinical indexes, and the machine learning model achieved an AUC of 0.94 and 0.86 in the Idiopathic pulmonary fibrosis classification task based on lung tissue samples and peripheral blood mononuclear cell samples, respectively. Our findings offer valuable insights into the pathogenesis of Idiopathic pulmonary fibrosis, providing new therapeutic directions and target genes for further investigation.

PMID:38075691 | PMC:PMC10704369 | DOI:10.3389/fgene.2023.1246983

Comput Struct Biotechnol J. 2023 Nov 14;21:5751-5764. doi: 10.1016/j.csbj.2023.11.018. eCollection 2023.

ABSTRACT

The incidence of lung cancer (LC) in Idiopathic Pulmonary Fibrosis (IPF) patients is more than twice that in non-IPF. This study aims to investigate IPF-to-LC pathogenesis and to develop a predictor for detecting IPF predisposing patients to LC. We conducted unsupervised clustering to detect high-risk subtypes from IPF to LC. Subsequently, we performed single-cell RNA-seq analysis to characterize high-risk IPF by examining the immune microenvironment. We identified 42 common immune function-related pathogenic genes between IPF and LC. We developed an LC risk classifier for IPF patients, comprising five genes: SPP1, MMP9, MMP12, FABP4, and IL1B. The five-gene classifier can successfully distinguish the high-risk population from IPF patients. High-risk IPF patients exhibited an immunosuppressive microenvironment with higher oncogene expression than low-risk patients. Single-cell analysis revealed that SPP1+ macrophages at the terminal of macrophages' developmental trajectory may promote the progression from IPF to LC. The strong crosstalk between SPP1+ macrophages and inflammation-related cancer-associated fibroblasts promoted the tumorigenic process in IPF. In vitro, assays showed that co-culturing macrophages overexpressing SPP1 with MRC-5 cells induced the transition of fibroblasts into cancer-associated fibroblasts. SPP1 produced by macrophages promoted epithelial-mesenchymal transition in alveolar epithelial cells via stimulating the upregulation of N-cadherin and Vimentin in MLE-12 cells. This study provided a novel method to identify the LC risk population from IPF, revealing the cellular interactions involved in the transition from IPF to LC. Our findings highlighted SPP1 as a critical driver in IPF progression, offering a potential target for therapy in fibrosis.

PMID:38074471 | PMC:PMC10708992 | DOI:10.1016/j.csbj.2023.11.018

Acta Biomater. 2023 Dec 8:S1742-7061(23)00710-9. doi: 10.1016/j.actbio.2023.12.006. Online ahead of print.

ABSTRACT

Targeted delivery of therapeutic drugs to fibrosis-promoting macrophages (FPMs) holds promise as a challenging yet effective approach for the treatment of idiopathic pulmonary fibrosis (IPF). Here, nanocarriers composed of Mn-curcumin metal-organic frameworks (MOFs) were utilized to deliver the immune inhibitor BLZ-945 to the lungs, with the goal of depleting fibrosis-promoting macrophages (FPMs) from fibrotic lung tissues. FPM targeting was achieved by functionalizing the nanocarrier surface with an M2-like FPM binding peptide (M2pep). As a result, significant therapeutic benefits were observed through the successful depletion of approximately 80% of the M2-like macrophages (FPMs) in a bleomycin-induced fibrosis mouse model treated with the designed M2-like FPM-targeting nanoparticle (referred to as M2NP-BLZ@Mn-Cur). Importantly, the released Mn2+ and curcumin after the degradation of M2NP-BLZ@Mn-Cur accumulated in the fibrotic lung tissue, which can alleviate inflammation and oxidative stress reactions, thereby further improving IPF therapy. This study presents a novel strategy with promising prospects for molecular-targeted fibrosis therapy. STATEMENT OF SIGNIFICANCE: Metal-organic frameworks (MOFs)- based nanocarriers equipped with both fibrosis-promoting macrophage (FPM)-specific targeting ability and therapeutic drugs are appealing for pulmonary fibrosis treatment. Here, we prepared M2pep (an M2-like FPM binding peptide)-modified and BLZ945 (a small molecule inhibitor of CSF1/CSF-1R axis)-loaded Mn-curcumin MOF nanoparticles (M2NP-BLZ@Mn-Cur) for pulmonary fibrosis therapy. The functionalized M2NP-BLZ@Mn-Cur nanoparticles can be preferentially taken up by FPMs, resulting in their depletion from fibrotic lung tissues. In addition, Mn2+ and curcumin released from the nanocarriers have anti-inflammation and immune regulation effects, which further enhance the antifibrotic effect of the nanoparticles.

PMID:38072226 | DOI:10.1016/j.actbio.2023.12.006

J Biol Chem. 2023 Dec 8:105530. doi: 10.1016/j.jbc.2023.105530. Online ahead of print.

ABSTRACT

Fibroblast to myofibroblast transdifferentiation mediates numerous fibrotic disorders, such as idiopathic pulmonary fibrosis (IPF). We have previously demonstrated that non-muscle myosin II (NMII) is activated in response to fibrotic lung extracellular matrix, thereby mediating myofibroblast transdifferentiation. NMII-A is known to interact with the calcium-binding protein S100A4, but the mechanism by which S100A4 regulates fibrotic disorders is unclear. In this study, we show that fibroblast S100A4 is a calcium-dependent, mechanoeffector protein that is uniquely sensitive to pathophysiologic-range lung stiffness (8 - 25 kPa), and thereby mediates myofibroblast transdifferentiation. Re-expression of endogenous fibroblast S100A4 rescues the myofibroblastic phenotype in S100A4 KO fibroblasts. Analysis of NMII-A/actin dynamics reveals that S100A4 mediates unraveling and redistribution of peripheral actomyosin to a central location, resulting in a contractile myofibroblast. Furthermore, S100A4 loss protects against murine in vivo pulmonary fibrosis, and S100A4 expression is dysregulated in IPF. Our data reveal a novel mechanosensor/effector role for endogenous fibroblast S100A4 in inducing cytoskeletal redistribution in fibrotic disorders such as IPF.

PMID:38072048 | DOI:10.1016/j.jbc.2023.105530