Int J Biol Macromol. 2024 Jun 6:132896. doi: 10.1016/j.ijbiomac.2024.132896. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive pulmonary disease with an unclear pathogenesis and no available specific drug treatment. The principal etiological factors are lung inflammation caused by environmental factors, damage to alveolar epithelial cells, leading to epithelial-mesenchymal transition (EMT), and the abnormal proliferation of fibroblasts. Here, we have demonstrated that fibroblast growth factor 21 (FGF21) ameliorates IPF via the autophagy pathway. We administered FGF21 to bleomycin (BLM)-treated mice, which ameliorated their defects in lung function, reduced the accumulation of collagen, restored tissue structure, reduced the deposition of hydroxyproline, reduced the expression of collagen I and α-SMA and increased the expression of E-cadherin. The expression of LC3BII and the number of autophagosomes were significantly higher in the lungs. The expression of AKT and mTOR was significantly reduced by FGF21 treatment. We also determined the effects of FGF21 in A549 cells treated with TGF-β, and found that FGF21 significantly inhibits activation of the AKT signaling pathway, thereby reducing TGF-β-induced EMT and preventing the uncontrolled proliferation of fibroblasts. We conclude that FGF21 ameliorates IPF by inhibiting the PI3K-AKT-mTOR signaling pathway and activating autophagy, which provides a theoretical basis for FGF21 to be used for the treatment of IPF.

PMID:38851619 | DOI:10.1016/j.ijbiomac.2024.132896

Eur J Pharmacol. 2024 Jun 6:176721. doi: 10.1016/j.ejphar.2024.176721. Online ahead of print.

ABSTRACT

Underactive bladder (UAB), characterized by a complex set of symptoms with few treatment options, can significantly reduce the quality of life of affected people. UAB is characterized by hyperplasia and fibrosis of the bladder wall as well as decreased bladder compliance. Pirfenidone is a powerful anti-fibrotic agent that inhibits the progression of fibrosis in people with idiopathic pulmonary fibrosis. In the current study, we evaluated the efficacy of pirfenidone in the treatment of bladder fibrosis in a UAB rat model. UAB was induced by crushing damage to nerve bundles in the major pelvic ganglion. Forty-two days after surgery, 1 mL distilled water containing pirfenidone (100, 300, or 500 mg/kg) was orally administered once every 2 days for a total of 10 times for 20 days to the rats in the pirfenidone-treated groups. Crushing damage to the nerve bundles caused voiding dysfunction, resulting in increased bladder weight and the level of fibrous related factors in the bladder, leading to UAB symptoms. Pirfenidone treatment improved urinary function, increased bladder weight and suppressed the expression of fibrosis factors. The results of this experiment suggest that pirfenidone can be used to ameliorate difficult-to-treat urological conditions such as bladder fibrosis. Therefore, pirfenidone treatment can be considered an option to improve voiding function in patient with incurable UAB.

PMID:38851561 | DOI:10.1016/j.ejphar.2024.176721

Sci Rep. 2024 Jun 7;14(1):13158. doi: 10.1038/s41598-024-63670-z.

ABSTRACT

Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress-strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO2/FiO2 ratio) during a PEEP trial performed within 24 h from intubation. Patient's stress-strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 [22.8-33.2] cmH2O versus 11.4 [10.3-14.6] cmH2O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress-strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS.

PMID:38849437 | DOI:10.1038/s41598-024-63670-z

Scand J Immunol. 2024 Jun 7:e13392. doi: 10.1111/sji.13392. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrosis in the lungs. Activated fibroblasts play a central role in fibrogenesis and express fibroblast activation protein α. A truncated, soluble form (sFAP) can be measured in blood and is a potential novel biomarker of disease activity. The aim was to study the association between sFAP and clinical, radiological, and histopathological measures of disease severity, progression, and survival in a prospective, multicentre, real-world cohort of patients with IPF. Patients with IPF were recruited from the tertiary interstitial lung disease centres in Denmark and followed for up to 3 years. Baseline serum levels of sFAP were measured by ELISA in patients with IPF and compared to healthy controls. Pulmonary function tests, 6-minute walk test and quality of life measures were performed at baseline and during follow-up. The study included 149 patients with IPF. Median sFAP in IPF was 49.6 ng/mL (IQR: 43.1-61.6 ng/mL) and in healthy controls 73.8 ng/mL (IQR: 62.1-92.0 ng/mL). Continuous sFAP was not associated with disease severity, progression or survival (p > 0.05). After dichotomization of sFAP below or above mean sFAP + 2 SD for healthy controls, higher levels of sFAP were associated with lower FVC % predicted during follow-up (p < 0.01). Higher than normal serum levels of sFAP were associated with longitudinal changes in FVC % predicted, but sFAP did not show clear associations with other baseline or longitudinal parameters. As such, sFAP has limited use as a biomarker of disease progression or survival in patients with IPF.

PMID:38849304 | DOI:10.1111/sji.13392

Am J Pathol. 2024 Jun 5:S0002-9440(24)00198-6. doi: 10.1016/j.ajpath.2024.04.011. Online ahead of print.

ABSTRACT

Idiopathic Pulmonary Fibrosis (IPF) is a progressive interstitial lung disease characterized by pulmonary fibroblasts overactivation, resulting in the accumulation of abnormal extracellular matrix (ECM) and lung parenchymal damage. Although the pathogenesis of IPF remains unclear, aging was proposed as the most prominent non-genetic risk factor. Previous studies have indicated that propionate metabolism undergoes reprogramming in the aging population, leading to the accumulation of the byproduct methylmalonic acid (MMA). This study aims to explore alterations in propionate metabolism in IPF and the impact of the byproduct MMA on pulmonary fibrosis. The present study revealed alterations in the expression of enzymes involved in propionate metabolism within IPF lung tissues, characterized by an increase in Propionyl-CoA carboxylase (PCC) and Methylmalonyl-CoA epimerase (MCEE) expression, and a decrease in Methylmalonyl-CoA mutase (MUT) expression. Knockdown of MUT, the key enzyme in propionate metabolism, in A549 cells induced a pro-fibrotic phenotype and activated co-cultured fibroblasts. MMA exacerbated BLM-induced mouse lung fibrosis and induced a pro-fibrotic phenotype in both epithelial cells and fibroblasts through activation of the canonical TGF-β/Smad pathway. Overall, our findings unveil an alteration of propionate metabolism in IPF, leading to MMA accumulation, thus exacerbating lung fibrosis through promoting pro-fibrotic phenotypic transitions via the canonical TGF-β/Smad signaling pathway.

PMID:38849030 | DOI:10.1016/j.ajpath.2024.04.011

Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2024 May;36(5):538-542. doi: 10.3760/cma.j.cn121430-20231119-00989.

ABSTRACT

OBJECTIVE: To evaluate the extracorporeal membrane oxygenation (ECMO) related outcomes during hospitalization during the intensive care unit (ICU) in idiopathic pulmonary fibrosis (IPF) patients with high body mass index (BMI, > 25 kg/m2) undergoing lung transplantation with ECMO support.

METHODS: A retrospective observational study was conducted. IPF patients who received ECMO during lung transplantation admitted to the Affiliated Wuxi People's Hospital of Nanjing Medical University from 2019 to 2020 were enrolled. Preoperative indicators including, demographics, comorbidities, arterial blood gas, and laboratory indicators; intraoperative indicators, such as lung lobe volume reduction, surgical type, surgical time, cold ischemia time, blood loss and transfusion volume; immediate indicators upon admission to the ICU, such as blood gas analysis and laboratory indicators; ECMO related outcomes, such as ECMO mode, ECMO support time, ECMO related complications (bleeding at the catheterization site, intraductal thrombosis, lower limb ischemia), and the length of ICU stay, duration of mechanical ventilation, and 30-day survival rate were collected. According to BMI, patients were divided into three groups: light weight group (BMI < 18.5 kg/m2), normal weight group (BMI 18.5-24.9 kg/m2), and overweight group (BMI ≥ 25.0 kg/m2). Mainly to compare the relevant outcomes of ECMO among patients during ICU.

RESULTS: A total of 114 IPF patients who received ECMO support during lung transplantation were collected, including 23 cases in the light weight group, 63 cases in the normal weight group, and 28 cases in the overweight group. Compared with patients with underweight and normal weight, overweight patients were more likely to have hypertension (46.4% vs. 8.7%, 23.8%, P < 0.01) and coronary heart disease (32.1% vs. 4.3%, 20.6%, P < 0.05) before surgery, which was consistent with international guidelines for obesity. Other clinical data (preoperative, intraoperative, ICU characteristics) showed no statistically significant differences and were comparable. There was no statistically significant difference in terms of ECMO related outcomes, such as ECMO related complications [veno-venous (V-V) mode: 78.3%, 77.8%, 78.6%, veno-arterial (V-A) mode: 21.7%, 22.2%, 21.4%], ECMO support time (hours: 61.70±20.03, 44.57±5.76, 41.77±7.26), ECMO related complications (bleeding at the catheterization site: 4.3%, 7.9%, 14.3%; intraductal thrombosis: 8.7%, 12.7%, 17.9%; lower limb ischemia: 8.7%, 12.7%, 14.3%), and the length of ICU stay (days: 11±3, 7±1, 9±1), duration of mechanical ventilation [days: 2 (2, 11), 2 (2, 6), 3 (2, 8)] among the light weight group, normal weight group, and overweight group (all P > 0.05). Kaplan-Meier survival curve analysis showed that there was no statistically significant difference in the 30-day cumulative survival rate among the three groups (Log-Rank test: χ 2 = 0.919, P = 0.632).

CONCLUSIONS: High BMI does not worsen ECMO-related outcomes or adversely affect early prognosis in IPF patients undergoing lung transplantation. BMI as a single parameter should not be a contraindication for the use of ECMO in lung transplantation surgery for IPF patients.

PMID:38845503 | DOI:10.3760/cma.j.cn121430-20231119-00989

Am J Respir Crit Care Med. 2024 Jun 6. doi: 10.1164/rccm.202312-2357LE. Online ahead of print.

NO ABSTRACT

PMID:38843499 | DOI:10.1164/rccm.202312-2357LE

Am J Respir Crit Care Med. 2024 Jun 6. doi: 10.1164/rccm.202310-1887OC. Online ahead of print.

ABSTRACT

RATIONALE: Accelerated biological aging has been implicated in the development of interstitial lung disease (ILD) and other diseases of aging but remains poorly understood.

OBJECTIVES: To identify plasma proteins that mediate the relationship between chronological age and survival association in patients with ILD.

METHODS: Causal mediation analysis was performed to identify plasma proteins that mediated the chronological age-survival relationship in an idiopathic pulmonary fibrosis (IPF) discovery cohort. Proteins mediating this relationship after adjustment for false discovery were advanced for testing in an independent ILD validation cohort and explored in a chronic obstructive pulmonary disease (COPD) cohort. A proteomic-based measure of biological age was constructed and survival analysis performed assessing the impact of biological age and peripheral blood telomere length on the chronological age-survival relationship.

RESULTS: Twenty-two proteins mediated the chronological age-survival relationship after adjustment for false discovery in the IPF discovery cohort (n=874), with nineteen remaining significant mediators of this relationship in the ILD validation cohort (n=983) and one mediating this relationship in the COPD cohort. Latent transforming growth factor beta binding protein 2 and ectodysplasin A2 receptor showed the strongest mediation across cohorts. A proteomic measure of biological age completely attenuated the chronological age-survival association and better discriminated survival than chronological age. Results were robust to adjustment for peripheral blood telomere length, which did not mediate the chronological age-survival relationship.

CONCLUSIONS: Molecular measures of aging completely mediate the relationship between chronological age and survival, suggesting that chronological age has no direct effect on ILD survival.

PMID:38843133 | DOI:10.1164/rccm.202310-1887OC

Am J Respir Crit Care Med. 2024 Jun 6. doi: 10.1164/rccm.202403-0636OC. Online ahead of print.

ABSTRACT

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a rare and progressive disease, which causes progressive cough, exertional dyspnea, impaired quality of life and death.

OBJECTIVES: Bexotegrast (PLN 74809) is an oral, once-daily, investigational drug in development for the treatment of IPF.

METHODS: This Phase 2a, multicenter, clinical trial, randomized participants with IPF to receive oral, once daily bexotegrast 40 mg, 80 mg, 160 mg, 320 mg, or placebo, with or without background IPF therapy (pirfenidone or nintedanib), in an approximately 3:1 ratio in each bexotegrast dose cohort, for at least 12 weeks. The primary endpoint was incidence of treatment-emergent adverse events (TEAEs). Exploratory efficacy endpoints included change from baseline in forced vital capacity (FVC); quantitative lung fibrosis (QLF) extent (%) and changes from baseline in fibrosis-related biomarkers.

MEASUREMENTS AND MAIN RESULTS: Bexotegrast was well tolerated with similar rates of TEAEs in the pooled bexotegrast and placebo groups (62/89 [69.7%] and 21/31 [67.7%], respectively). Diarrhea was the most common TEAE; most participants with diarrhea also received nintedanib. Bexotegrast treated participants experienced a reduction in FVC decline over 12 weeks vs. placebo, with or without background therapy. A dose-dependent antifibrotic effect of bexotegrast was observed with QLF imaging and a decrease in fibrosis-associated biomarkers was observed with bexotegrast vs. placebo.

CONCLUSIONS: Bexotegrast demonstrated a favorable safety and tolerability profile, up to 12 weeks for the doses studied. Exploratory analyses suggest an antifibrotic effect according to FVC, QLF imaging, and circulating levels of fibrosis biomarkers. Clinical trial registration available at www.

CLINICALTRIALS: gov, ID: NCT04396756. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

PMID:38843105 | DOI:10.1164/rccm.202403-0636OC

Front Cell Infect Microbiol. 2024 May 22;14:1348685. doi: 10.3389/fcimb.2024.1348685. eCollection 2024.

ABSTRACT

BACKGROUND: The microbiota-gut-lung axis has elucidated a potential association between gut microbiota and idiopathic pulmonary fibrosis (IPF). However, there is a paucity of population-level studies with providing robust evidence for establishing causality. This two-sample Mendelian randomization (MR) analysis aimed to investigate the causal relationship between the gut microbiota and IPF as well as lung function.

MATERIALS AND METHODS: Adhering to Mendel's principle of inheritance, this MR analysis utilized summary-level data from respective genome-wide association studies (GWAS) involving 211 gut microbial taxa, IPF, and lung function indicators such as FEV1, FVC, and FEV1/FVC. A bidirectional two-sample MR design was employed, utilizing multiple MR analysis methods, including inverse variance-weighted (IVW), weighted median, MR-Egger, and weighted mode. Multivariable MR (MVMR) was used to uncover mediating factors connecting the exposure and outcome. Additionally, comprehensive sensitivity analyses were conducted to ensure the robustness of the results.

RESULTS: The MR results confirmed four taxa were found causally associated with the risk of IPF. Order Bifidobacteriales (OR=0.773, 95% CI: 0.610-0.979, p=0.033), Family Bifidobacteriaceae (OR=0.773, 95% CI: 0.610-0.979, p=0.033), and Genus RuminococcaceaeUCG009 (OR=0.793, 95% CI: 0.652-0.965, p=0.020) exerted protective effects on IPF, while Genus Coprococcus2 (OR=1.349, 95% CI: 1.021-1.783, p=0.035) promote the development of IPF. Several taxa were causally associated with lung function, with those in Class Deltaproteobacteria, Order Desulfovibrionales, Family Desulfovibrionaceae, Class Verrucomicrobiae, Order Verrucomicrobiales and Family Verrucomicrobiaceae being the most prominent beneficial microbiota, while those in Family Lachnospiraceae, Genus Oscillospira, and Genus Parasutterella were associated with impaired lung function. As for the reverse analysis, MR results confirmed the effects of FEV1 and FVC on the increased abundance of six taxa (Phylum Actinobacteria, Class Actinobacteria, Order Bifidobacteriales, Family Bifidobacteriaceae, Genus Bifidobacterium, and Genus Ruminiclostridium9) with a boosted level of evidence. MVMR suggested monounsaturated fatty acids, total fatty acids, saturated fatty acids, and ratio of omega-6 fatty acids to total fatty acids as potential mediating factors in the genetic association between gut microbiota and IPF.

CONCLUSION: The current study suggested the casual effects of the specific gut microbes on the risk of IPF and lung function. In turn, lung function also exerted a positive role in some gut microbes. A reasonable dietary intake of lipid substances has a certain protective effect against the occurrence and progression of IPF. This study provides novel insights into the potential role of gut microbiota in IPF and indicates a possible gut microbiota-mediated mechanism for the prevention of IPF.

PMID:38841114 | PMC:PMC11150651 | DOI:10.3389/fcimb.2024.1348685

BMC Pulm Med. 2024 Jun 4;24(1):266. doi: 10.1186/s12890-024-03081-y.

ABSTRACT

BACKGROUND: sphingosine-1-phosphate (S1P), a naturally occurring sphingolipid, has been involved in pulmonary interstitial remodeling signaling. However, no study has examined its clinical merits for interstitial lung disease (ILD). This study aimed to investigate the serum level of S1P in ILD patients and its clinical correlation with the severity of disease in the two main types of ILDs: the IPF and the CTD-ILD patients.

METHODS: This retrospective observational pilot study included 67 ILD patients and 26 healthy controls. These patients were stratified into the IPF group (35) and the CTD-ILD group (32). The severity of ILD was evaluated through pulmonary function indicators and the length of hospital stay.

RESULTS: Serum S1P level was statistically higher in ILD patients than in health control (p = 0.002), while the Serum S1P levels in CTD-ILD and IPF patients were comparable. Serum S1P level further showed statistically negative correlation with pulmonary function indexes (TLC% pred, FVC% pred and FEV1% pred) and positive correlation with length of hospital stay (r = -0.38, p = 0.04; r = -0.41, p = 0.02, r = -0.37, p = 0.04; r = 0.42, p = 0.02, respectively) in CTD-ILD patients, although serum S1P level was not significantly correlated with inflammatory indexes. The IPF patients failed to exhibit a significant correlation of serum S1P level with pulmonary function and length of hospital stay.

CONCLUSIONS: Serum S1P level might be a clinically useful biomarker in evaluating the severity of CTD-ILD patients rather than IPF patients.

PMID:38835000 | DOI:10.1186/s12890-024-03081-y

BMJ Open Respir Res. 2024 Jun 4;11(1):e002148. doi: 10.1136/bmjresp-2023-002148.

ABSTRACT

OBJECTIVE: This study aims to explore the common genetic basis between respiratory diseases and to identify shared molecular and biological mechanisms.

METHODS: This genome-wide pleiotropic association study uses multiple statistical methods to systematically analyse the shared genetic basis between five respiratory diseases (asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, lung cancer and snoring) using the largest publicly available genome wide association studies summary statistics. The missions of this study are to evaluate global and local genetic correlations, to identify pleiotropic loci, to elucidate biological pathways at the multiomics level and to explore causal relationships between respiratory diseases. Data were collected from 27 November 2022 to 30 March 2023 and analysed from 14 April 2023 to 13 July 2023.

MAIN OUTCOMES AND MEASURES: The primary outcomes are shared genetic loci, pleiotropic genes, biological pathways and estimates of genetic correlations and causal effects.

RESULTS: Significant genetic correlations were found for 10 paired traits in 5 respiratory diseases. Cross-Phenotype Association identified 12 400 significant potential pleiotropic single-nucleotide polymorphism at 156 independent pleiotropic loci. In addition, multitrait colocalisation analysis identified 15 colocalised loci and a subset of colocalised traits. Gene-based analyses identified 432 potential pleiotropic genes and were further validated at the transcriptome and protein levels. Both pathway enrichment and single-cell enrichment analyses supported the role of the immune system in respiratory diseases. Additionally, five pairs of respiratory diseases have a causal relationship.

CONCLUSIONS AND RELEVANCE: This study reveals the common genetic basis and pleiotropic genes among respiratory diseases. It provides strong evidence for further therapeutic strategies and risk prediction for the phenomenon of respiratory disease comorbidity.

PMID:38834332 | DOI:10.1136/bmjresp-2023-002148

Expert Opin Pharmacother. 2024 Jun 4:1-9. doi: 10.1080/14656566.2024.2354460. Online ahead of print.

ABSTRACT

INTRODUCTION: Following the INPULSIS and ASCEND studies, leading to the first two approved antifibrotic therapies for patients with IPF, ongoing investigations are firmly exploring novel agents for a targeted effective and better tolerated therapy able to improve the natural history of the disease.

AREAS COVERED: This review aims to analyze recent advances in pharmacological research of IPF, discussing the currently available treatments and the novel drugs under investigation in phase 3 trials, with particular emphasis on BI 1015550 and inhaled treprostinil. The literature search utilized Medline and Clinicaltrials.org databases. Critical aspects of clinical trial design in IPF are discussed in light of recently completed phase III studies.

EXPERT OPINION: While randomized clinical trials in IPF are currently underway, future objectives should explore potential synergistic benefits when combining novel molecules with the existing therapies and identify more specific molecular targets. Moreover, refining the study design represent another crucial goal. The aim of the pharmacological research will be not only stabilizing but also potentially reversing the fibrotic changes in IPF.

PMID:38832823 | DOI:10.1080/14656566.2024.2354460

Aging Cell. 2024 Jun 3:e14229. doi: 10.1111/acel.14229. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis is a progressive and age-related disease that results from impaired lung repair following injury. Targeting senescent myofibroblasts with senolytic drugs attenuates pulmonary fibrosis, revealing a detrimental role of these cells in pulmonary fibrosis. The mechanisms underlying the occurrence and persistence of senescent myofibroblasts in fibrotic lung tissue require further clarification. In this study, we demonstrated that senescent myofibroblasts are resistant to apoptosis by upregulating the proapoptotic protein BAX and antiapoptotic protein BCL-2 and BCL-XL, leading to BAX inactivation. We further showed that high levels of inactive BAX-mediated minority mitochondrial outer membrane permeabilization (minority MOMP) promoted DNA damage and myofibroblasts senescence after insult by a sublethal stimulus. Intervention of minority MOMP via the inhibition of caspase activity by quinolyl-valyl-O-methylaspartyl-[2,6-difluorophenoxy]-methyl ketone (QVD-OPH) or BAX knockdown significantly reduced DNA damage and ultimately delayed the progression of senescence. Moreover, the BAX activator BTSA1 selectively promoted the apoptosis of senescent myofibroblasts, as BTSA1-activated BAX converted minority MOMP to complete MOMP while not injuring other cells with low levels of BAX. Furthermore, therapeutic activation of BAX with BTSA1 effectively reduced the number of senescent myofibroblasts in the lung tissue and alleviated both reversible and irreversible pulmonary fibrosis. These findings advance the understanding of apoptosis resistance and cellular senescence mechanisms in senescent myofibroblasts in pulmonary fibrosis and demonstrate a novel senolytic drug for pulmonary fibrosis treatment.

PMID:38831635 | DOI:10.1111/acel.14229

bioRxiv [Preprint]. 2024 May 23:2024.05.21.595153. doi: 10.1101/2024.05.21.595153.

ABSTRACT

Fibrosis drives end-organ damage in many diseases. However, clinical trials targeting individual upstream activators of fibroblasts, such as TGFβ, have largely failed. Here, we target the leukemia inhibitory factor receptor (LIFR) as a "master amplifier" of multiple upstream activators of lung fibroblasts. In idiopathic pulmonary fibrosis (IPF), the most common fibrotic lung disease, we found that lung myofibroblasts had high LIF expression. Further, TGFβ1, one of the key drivers of fibrosis, upregulated LIF expression in IPF fibroblasts. In vitro anti-LIFR antibody blocking on human IPF lung fibroblasts reduced induction of profibrotic genes downstream of TGFβ1, IL-4 and IL-13. Further, siRNA silencing of LIFR in IPF precision cut lung slices reduced expression of fibrotic proteins. Together, we find that LIFR drives an autocrine positive feedback loop that amplifies and sustains pathogenic activation of IPF fibroblasts downstream of multiple external stimuli, implicating LIFR as a therapeutic target in fibrosis.

SIGNIFICANCE STATEMENT: Fibroblasts have a central role in the pathogenesis of fibrotic diseases. However, due to in part to multiple profibrotic stimuli, targeting a single activator of fibroblasts, like TGFβ, has not yielded successful clinical treatments. We hypothesized that a more effective therapeutic strategy is identifying a downstream "master amplifier" of a range of upstream profibrotic stimuli. This study identifies the leukemia inhibitory factor receptor (LIFR) on fibrotic lung fibroblasts amplifies multiple profibrotic stimuli, such as IL-13 and TGFβ. Blocking LIFR reduced fibrosis in ex vivo lung tissue from patients with idiopathic pulmonary fibrosis (IPF). LIFR, acting as a master amplifier downstream of fibroblast activation, offers an alternative therapeutic strategy for fibrotic diseases.

PMID:38826450 | PMC:PMC11142130 | DOI:10.1101/2024.05.21.595153

Respirology. 2024 Jun 2. doi: 10.1111/resp.14763. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVE: Evidence for the benefit of steroid therapy in acute exacerbations (AEs) of idiopathic pulmonary fibrosis (IPF) is limited; however, they remain a cornerstone of management in other fibrotic interstitial lung diseases. This retrospective observational study assesses the effect of steroid treatment on in-hospital mortality in patients with acute exacerbation of fibrotic interstitial lung disease (AE-FILD) including IPF and non-IPF ILDs.

METHODS: AE-FILD cases over a 10-year period were filtered using a code-based algorithm followed by individual case evaluation. Binary logistic regression analysis was used to assess the relationship between corticosteroid treatment (defined as ≥0.5 mg/kg/day of prednisolone-equivalent for ≥3 days within the first 72 h of admission) and in-hospital mortality or need for lung transplantation. Secondary outcomes included readmission, overall survival, requirement for domiciliary oxygen and rehabilitation.

RESULTS: Across two centres a total of 107 AE-FILD subjects were included, of which 46 patients (43%) received acute steroid treatment. The steroid cohort was of younger age with fewer comorbidities but had higher oxygen requirements. Pre-admission FVC and DLCO, distribution of diagnoses and smoking history were similar. The mean steroid treatment dose was 4.59 mg/kg/day. Steroid use appeared to be associated with increased risk of inpatient mortality or transplantation (OR 4.11; 95% CI 1.00-16.83; p = 0.049). In the steroid group, there appeared to be a reduced risk of all-cause mortality in non-IPF patients (HR 0.21; 95% CI 0.04-0.96; p = 0.04) compared to their IPF counterparts. Median survival was reduced in the steroid group (221 vs. 520.5 days) with increased risk of all-cause mortality (HR 3.25; 95% CI 1.56-6.77; p < 0.01).

CONCLUSION: In this two-centre retrospective study of 107 patients, AE-FILD demonstrates a high risk of mortality, at a level similar to that seen for AE-IPF, despite steroid treatment. Clinicians should consider other precipitating factors for exacerbations and use steroids judiciously. Further prospective trials are needed to determine the role of corticosteroids in AE-FILD.

PMID:38825348 | DOI:10.1111/resp.14763

Am J Respir Crit Care Med. 2024 May 31. doi: 10.1164/rccm.202402-0337LE. Online ahead of print.

NO ABSTRACT

PMID:38820300 | DOI:10.1164/rccm.202402-0337LE

Am J Respir Crit Care Med. 2024 May 31. doi: 10.1164/rccm.202404-0789LE. Online ahead of print.

NO ABSTRACT

PMID:38820297 | DOI:10.1164/rccm.202404-0789LE

Am J Respir Cell Mol Biol. 2024 May 31. doi: 10.1165/rcmb.2024-0124PS. Online ahead of print.

ABSTRACT

Pulmonary fibrosis (PF) can be idiopathic or driven by a specific insult or disease process. Inflammation plays a role in the pathophysiology, the extent of which remains a longstanding topic of debate. More recently there has been increasing interest in a potential inciting role for aberrant lipid metabolism. Lipids are essential for the structure and function of all cell membranes but specifically in the lung for surfactant composition, intra and intercellular lipid mediators and lipofibroblasts. Clinically, there is evidence of increased lipid deposition in the subpleural space, and at a whole lung tissue level in PF. There is evidence of increased parenchymal lipid deposition and abnormal mediastinal fat shape on chest CT. A protective role for cholesterol lowering drugs including statins and ezetimibe has been described in PF. At a cellular level, fatty acid (FA), phospholipid (PL) and glucose metabolism are disordered, as is the production of lipid mediators. In this perspectives piece we put forward the argument that there is substantive clinical and biological evidence to support a role for aberrant lipid metabolism and lipid mediators in the pathogenesis of PF.

PMID:38820234 | DOI:10.1165/rcmb.2024-0124PS

J Cancer. 2024 Apr 29;15(11):3406-3417. doi: 10.7150/jca.95437. eCollection 2024.

ABSTRACT

Background: Pulmonary diseases and esophageal cancer are highly prevalent conditions with rising incidence worldwide. Prior evidence supports shared environmental and behavioral factors, but less is known regarding potential genetic links underlying this comorbidity. This study aimed to elucidate the complex genetic relationship between chronic lung diseases and esophageal cancer risk. Methods: Linkage disequilibrium score regression assessed the genetic correlation between esophageal cancer and asthma, COPD, and idiopathic pulmonary fibrosis leveraging extensive GWAS datasets. Pleiotropic analysis, gene-set enrichment, eQTL mapping, and mendelian randomization causality analyses were then conducted to identify specific shared genetic variants, enriched pathways, causal relationships and gene regulatory mechanisms connecting lung disease and cancer susceptibility. Results: Significant genetic correlations were observed between esophageal cancer and both COPD and asthma, but not idiopathic pulmonary fibrosis. Further analyses identified 13 pleiotropic loci and 6 shared genes including CHRNA4, ERBB3, and SMAD3, as well as pathways related to immune function. eQTL integration highlighted 53 genes like SOCS1, FGF2, and CHRNA5 with tissue-specific regulatory effects on disease risk. Bidirectional relationships were noted, whereby genetic predisposition to asthma and COPD increased esophageal cancer risk, while cancer liability reciprocally raised pulmonary fibrosis risk. Conclusions: These genomic analyses provide initial evidence that shared genetic factors may underpin the comorbidity between lung conditions and esophageal malignancy. The genes and pathways identified offer insights into biological mechanisms linking both diseases, aiding future screening, prevention and therapeutic efforts to mitigate this growing comorbidity burden.

PMID:38817868 | PMC:PMC11134432 | DOI:10.7150/jca.95437