Pirfenidone, nintedanib and N-acetylcysteine for the treatment of idiopathic pulmonary fibrosis: A systematic review and meta-analysis

Emerging pharmacological options in the treatment of idiopathic pulmonary fibrosis (IPF)

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a progressive-fibrosing lung disease with a median survival of less than 5 years. Currently, two agents, pirfenidone and nintedanib are approved for this disease, and both have been shown to reduce the rate of decline in lung function in patients with IPF. However, both have significant adverse effects and neither completely arrest the decline in lung function.

AREAS COVERED

Thirty experimental agents with unique mechanisms of action that are being evaluated for the treatment of IPF are discussed. These agents work through various mechanisms of action, these include inhibition of transcription nuclear factor k-B on fibroblasts, reduced expression of metalloproteinase 7, the generation of more lysophosphatidic acids, blocking the effects of transforming growth factor ß, and reducing reactive oxygen species as examples of some unique mechanisms of action of these agents.

EXPERT OPINION

New drug development has the potential to expand the treatment options available in the treatment of IPF patients. It is expected that the adverse drug effect profiles will be more favorable than current agents. It is further anticipated that these new agents or combinations of agents will arrest the fibrosis, not just slow the fibrotic process.

Lung cell transplantation for pulmonary fibrosis

Idiopathic pulmonary fibrosis is a major cause of death with few treatment options. Here, we demonstrate the therapeutic efficacy for lung fibrosis of adult lung cell transplantation using a single-cell suspension of the entire lung in two distinct mouse systems: bleomycin treatment and mice lacking telomeric repeat-binding factor 1 expression in alveolar type 2 (AT2) cells (SPC-Cre TRF1fl/fl), spontaneously developing fibrosis. In both models, the progression of fibrosis was associated with reduced levels of host lung progenitors, enabling engraftment of donor progenitors without any additional conditioning, in contrast to our previous studies. Two months after transplantation, engrafted progenitors expanded to form numerous donor-derived patches comprising AT1 and AT2 alveolar cells, as well as donor-derived mesenchymal and endothelial cells. This lung chimerism was associated with attenuation of fibrosis, as demonstrated histologically, biochemically, by computed tomography imaging, and by lung function measurements. Our study provides a strong rationale for the treatment of lung fibrosis using lung cell transplantation.

Monomeric compounds from natural products for the treatment of pulmonary fibrosis: a review

Pulmonary fibrosis (PF) is the end stage of lung injury and chronic lung diseases that results in diminished lung function, respiratory failure, and ultimately mortality. Despite extensive research, the pathogenesis of this disease remains elusive, and effective therapeutic options are currently limited, posing a significant clinical challenge. In addition, research on traditional Chinese medicine and naturopathic medicine is hampered by several complications due to complex composition and lack of reference compounds. Natural product monomers, possessing diverse biological activities and excellent safety profiles, have emerged as potential candidates for preventing and treating PF. The effective anti-PF ingredients identified can be generally divided into flavonoids, saponins, polysaccharides, and alkaloids. Specifically, these monomeric compounds can attenuate inflammatory response, oxidative stress, and other physiopathological processes of the lung through many signaling pathways. They also improve pulmonary factors. Additionally, they ameliorate epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transdifferentiation (FMT) by regulating multiple signal amplifiers in the lungs, thereby mitigating PF. This review highlights the significant role of monomer compounds derived from natural products in reducing inflammation, oxidative stress, and inhibiting EMT process. The article provides comprehensive information and serves as a solid foundation for further exploration of new strategies to harness the potential of botanicals in the treatment of PF.

Therapeutic approaches and novel antifibrotic agents in renal fibrosis: A comprehensive review

Renal fibrosis (RF) is one of the underlying pathological conditions leading to progressive loss of renal function and end-stage renal disease (ESRD). Over the years, various therapeutic approaches have been explored to combat RF and prevent ESRD. Despite significant advances in understanding the underlying molecular mechanism(s), effective therapeutic interventions for RF are limited. Current therapeutic strategies primarily target these underlying mechanisms to halt or reverse fibrotic progression. Inhibition of transforming growth factor-β (TGF-β) signaling, a pivotal mediator of RF has emerged as a central strategy to manage RF. Small molecules, peptides, and monoclonal antibodies that target TGF-β receptors or downstream effectors have demonstrated potential in preclinical models. Modulating the renin-angiotensin system and targeting the endothelin system also provide established approaches for controlling fibrosis-related hemodynamic changes. Complementary to pharmacological strategies, lifestyle modifications, and dietary interventions contribute to holistic management. This comprehensive review aims to summarize the underlying mechanisms of RF and provide an overview of the therapeutic strategies and novel antifibrotic agents that hold promise in its treatment.

Antifibrotics and mortality in idiopathic pulmonary fibrosis: external validity and avoidance of immortal time bias

BACKGROUND AND OBJECTIVE

Pooled analyses of previous randomized controlled trials reported that antifibrotics improved survival in patients with idiopathic pulmonary fibrosis (IPF), but the results were only based on short-term outcome data from selected patients who met strict criteria. Observational studies/meta-analyses also suggested that antifibrotics improve survival, but these studies failed to control for immortal time bias that considerably exaggerates drug effects. Therefore, whether antifibrotics truly improve long-term survival in patients with IPF in the real world remains undetermined and requires external validity.

METHODS

We used data from the Japanese National Claims Database to estimate the intention-to-treat effect of antifibrotics on mortality. To address immortal time bias, we employed models treating antifibrotic initiation as a time-dependent covariate and target trial emulation (TTE), both incorporating new-user designs for antifibrotics and treating lung transplantation as a competing event.

RESULTS

Of 30,154 patients with IPF, 14,525 received antifibrotics. Multivariate Fine-Gray models with antifibrotic initiation as a time-dependent covariate revealed that compared with no treatment, nintedanib (adjusted hazard ratio [aHR], 0.85; 95% confidence interval [CI], 0.81-0.89) and pirfenidone (aHR, 0.89; 95% CI, 0.86-0.93) were associated with reduced mortality. The TTE model also replicated the associations of nintedanib (aHR, 0.69; 95% CI, 0.65-0.74) and pirfenidone (aHR, 0.81; 95% CI, 0.78-0.85) with reduced mortality. Subgroup analyses confirmed this association regardless of age, sex, and comorbidities, excluding certain subpopulations.

CONCLUSIONS

The results of this large-scale real-world analysis support the generalizability of the association between antifibrotics and improved survival in various IPF populations.

Anti-Inflammatory and Anti-Oxidant Properties of N-Acetylcysteine: A Fresh Perspective

N-acetyl-L-cysteine (NAC) was initially introduced as a treatment for mucus reduction and widely used for chronic respiratory conditions associated with mucus overproduction. However, the mechanism of action for NAC extends beyond its mucolytic activity and is complex and multifaceted. Contrary to other mucoactive drugs, NAC has been found to exhibit antioxidant, anti-infective, and anti-inflammatory activity in pre-clinical and clinical reports. These properties have sparked interest in its potential for treating chronic lung diseases, including chronic obstructive pulmonary disease (COPD), bronchiectasis (BE), cystic fibrosis (CF), and idiopathic pulmonary fibrosis (IPF), which are associated with oxidative stress, increased levels of glutathione and inflammation. NAC's anti-inflammatory activity is noteworthy, and it is not solely secondary to its antioxidant capabilities. In ex vivo models of COPD exacerbation, the anti-inflammatory effects have been observed even at very low doses, especially with prolonged treatment. The mechanism involves the inhibition of the activation of NF-kB and neurokinin A production, resulting in a reduction in interleukin-6 production, a cytokine abundantly present in the sputum and breath condensate of patients with COPD and correlates with the number of exacerbations. The unique combination of mucolytic, antioxidant, anti-infective, and anti-inflammatory properties positions NAC as a safe, cost-effective, and efficacious therapy for a plethora of respiratory conditions.

Association between statin use and the risk for idiopathic pulmonary fibrosis and its prognosis: a nationwide, population-based study

Given the pleiotropic effects of statins beyond their lipid-lowering effects, there have been attempts to evaluate the role of statin therapy in IPF, but they have shown inconclusive results. Data from the National Health Insurance Service (NHIS) database of South Korea were used to investigate the effects of statin therapy on IPF. The IPF cohort consisted of a total of 10,568 patients who were newly diagnosed with IPF between 2010 and 2017. These patients were then matched in a 1:3 ratio to 31,704 subjects from a control cohort without IPF, with matching based on age and sex. A case-control study was performed to evaluate the association between statin use and the risk for IPF, and the multivariable analysis revealed that statin use was associated with a lower risk for IPF (adjusted OR 0.847, 95% CI 0.800-0.898). Using the IPF cohort, we also evaluated whether statin use at the time of diagnosis was associated with future clinical outcomes. The statin use at the time of IPF diagnosis was associated with improved overall survival (adjusted HR 0.779, 95% CI 0.709-0.856). Further prospective studies are needed to clarify the role of statin therapy in IPF.

Lung Transplant Outcomes for Idiopathic Pulmonary Fibrosis: Are We Improving?

BACKGROUND

After implementation of the Lung Allocation Score in 2005, idiopathic pulmonary fibrosis (IPF) emerged as the most common indication for lung transplantation (LT) in the United States. The age and comorbidity of patients undergoing LT have since increased, and the indications for LT have evolved. However, limited data have been used to analyze more recent outcomes among the IPF population.

METHODS

This study analyzed LTs for the primary indication of IPF by using the United Network for Organ Sharing database. An eras-based analysis was performed, comparing patient characteristics, survival, and related outcomes during 2005 to 2009 (era 1) and 2010 to 2014 (era 2) with χ2, Wilcoxon rank sum, and Kaplan-Meier analyses. The study compared 1-year survival from 2005 to 2020 and survival at milestones ranging from 1 month to 5 years. Two adjusted Cox proportional hazards models were conducted: 5-year survival by era and 1-year survival annually from 2010 to 2020.

RESULTS

From era 1 (n = 1818) to era 2 (n = 3227), the median age of LT recipients increased from 61 to 63 years (P < .001). The percentage of patients in the intensive care unit before LT climbed from 7.7% to 12.1% (P < .001), and the percentage of patients with diabetes grew from 17.9% to 19.4% (P = .003). Despite increased severity of illness, 5-year survival increased from 51.9% in era 1 to 55.2% in era 2 (P = .02). Adjusted modeling indicated that LT during era 2 featured a 17% hazard reduction compared with era 1 (hazard ratio, 0.83; 95% CI, 0.76-0.91).

CONCLUSIONS

Survival is improving for patients undergoing LT for IPF, despite the challenges of transplant recipients with progressively higher risk profiles.

Respiratory infection risk in primary Sjögren's syndrome complicated with interstitial lung disease: a retrospective study

OBJECTIVES

To explore clinical and laboratory characteristics of primary Sjögren's syndrome (pSS) complicated with interstitial lung disease (ILD) and investigate the risk factors for respiratory infections in pSS-ILD.

METHODS

A cohort of 162 pSS-ILD patients in Peking University People's Hospital from 2015 to 2020 were included, and all medical records were completely collected. We screened 53 patients suffering from respiratory infections as study cases, compared with 109 age- and sex-matched controls. Differences between infection group and control group were compared. Univariate and multivariate binary logistic regression tests were conducted to identify potential risk factors for respiratory infections in pSS-ILD patients.

RESULTS

Among 162 pSS-ILD patients, 32.72% (53/162) suffered from respiratory infections. The most frequent type of ILD was nonspecific interstitial pneumonia (32.08%, 51/159), and the most common type of pathogen was bacteria (64.25%, 34/53). Infection group showed higher levels of ESSDAI (P < 0.001), CRP (P < 0.001), ESR (P = 0.003), and C3 (P = 0.020) but lower level of DLCO-SB (P = 0.015). Univariate logistic model revealed that PAH and the use of glucocorticoid increased infection risk in pSS-ILD patients. On multivariate logistic regression analysis, PAH (OR = 3.993, 95% CI = 1.192-13.373, P = 0.025) and severe reduction of DLCO (DLCO-SB < 40%, OR = 4.625, 95% CI = 1.281-16.702, P = 0.019) were significantly associated with increased risk of respiratory infections in pSS-ILD patients.

CONCLUSION

Among pSS-ILD patients, the most frequent type of ILD was nonspecific interstitial pneumonia. In patients with infection, bacteria were the most common pathogen. Higher levels of ESSDAI, CRP, ESR, and C3 may be correlated with increased infection risk. PAH and reduction of DLCO were identified as independent risk factors. Key Points • ILD and infectious diseases severely affect pSS patient conditions. • Higher levels of ESSDAI, CRP, ESR, and C3 may be correlated with increased infection risks in pSS-ILD. • PAH and reduction of DLCO were identified as independent risk factors for lower respiratory infection.

The SIRT1/Nrf2 signaling pathway mediates the anti-pulmonary fibrosis effect of liquiritigenin

BACKGROUND

At present, the treatment options available for idiopathic pulmonary fibrosis are both limited and often come with severe side effects, emphasizing the pressing requirement for innovative therapeutic alternatives. Myofibroblasts, which hold a central role in pulmonary fibrosis, have a close association with the Smad signaling pathway induced by transforming growth factor-β1 (TGF-β1) and the transformation of myofibroblasts driven by oxidative stress. Liquiritigenin, an active compound extracted from the traditional Chinese herb licorice, boasts a wide array of biomedical properties, such as anti-fibrosis and anti-oxidation. The primary objective of this study was to examine the impact of liquiritigenin on bleomycin-induced pulmonary fibrosis in mice and the underlying mechanisms.

METHODS

The anti-pulmonary fibrosis and anti-oxidant effects of liquiritigenin in vivo were tested by HE staining, Masson staining, DHE staining and bio-chemical methods. In vitro, primary mouse lung fibroblasts were treated with TGF-β1 with or without liquiritigenin, the effects of liquiritigenin in inhibiting differentiation of myofibroblasts and facilitating the translocation of Nrf2 were valued using Quantitative real-time polymerase chain reaction (Q-PCR), western blotting and immunofluorescence. Nrf2 siRNA and SIRT1 siRNA were used to investigate the mechanism underlies liquiritigenin's effect in inhibiting myofibroblast differentiation.

RESULTS

Liquiritigenin displayed a dose-dependent reduction effect in bleomycin-induced fibrosis. In laboratory experiments, it was evident that liquiritigenin possessed the ability to enhance and activate sirtuin1 (SIRT1), thereby facilitating the nuclear translocation of Nrf2 and mitigating the oxidative stress-induced differentiation of primary mouse myofibroblasts. Moreover, our investigation unveiled that SIRT1 not only regulated myofibroblast differentiation via Nrf2-mediated antioxidant responses against oxidative stress but also revealed liquiritigenin's activation of SIRT1, enabling direct binding to Smad. This led to decreased phosphorylation of the Smad complex, constrained nuclear translocation, and suppressed acetylation of the Smad complex, ultimately curtailing the transcription of fibrotic factors. Validation in live subjects provided substantial evidence for the anti-fibrotic efficacy of liquiritigenin through the SIRT1/Nrf2 signaling pathway.

CONCLUSIONS

Our findings imply that targeting myofibroblast differentiation via the SIRT1/Nrf2 signaling pathway may constitute a pivotal strategy for liquiritigenin-based therapy against pulmonary fibrosis.

A Methodological Approach to Identify Natural Compounds with Antifibrotic Activity and the Potential to Treat Pulmonary Fibrosis Using Single-Cell Sequencing and Primary Human Lung Macrophages

Idiopathic pulmonary fibrosis (IPF) is the most common and lethal form of the interstitial pneumonias. The cause of the disease is unknown, and new therapies that stop or reverse disease progression are desperately needed. Recent advances in next-generation sequencing have led to an abundance of freely available, clinically relevant, organ-and-disease-specific, single-cell transcriptomic data, including studies from patients with IPF. We mined data from published IPF data sets and identified gene signatures delineating pro-fibrotic or antifibrotic macrophages and then used the Enrichr platform to identify compounds with the potential to drive the macrophages toward the antifibrotic transcriptotype. We then began testing these compounds in a novel in vitro phenotypic drug screening assay utilising human lung macrophages recovered from whole-lung lavage of patients with silicosis. As predicted by the Enrichr tool, glitazones potently modulated macrophage gene expression towards the antifibrotic phenotype. Next, we assayed a subset of the NatureBank pure compound library and identified the cyclobutane lignan, endiandrin A, which was isolated from the roots of the endemic Australian rainforest plant, Endiandra anthropophagorum, with a similar antifibrotic potential to the glitazones. These methods open new avenues of exploration to find treatments for lung fibrosis.

Time-course transcriptome analysis of a double challenge bleomycin-induced lung fibrosis rat model uncovers ECM homoeostasis-related translationally relevant genes

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is an irreversible disorder with a poor prognosis. The incomplete understanding of IPF pathogenesis and the lack of accurate animal models is limiting the development of effective treatments. Thus, the selection of clinically relevant animal models endowed with similarities with the human disease in terms of lung anatomy, cell biology, pathways involved and genetics is essential. The bleomycin (BLM) intratracheal murine model is the most commonly used preclinical assay to evaluate new potential therapies for IPF. Here, we present the findings derived from an integrated histomorphometric and transcriptomic analysis to investigate the development of lung fibrosis in a time-course study in a BLM rat model and to evaluate its translational value in relation to IPF.

METHODS

Rats were intratracheally injected with a double dose of BLM (days 0-4) and sacrificed at days 7, 14, 21, 28 and 56. Histomorphometric analysis of lung fibrosis was performed on left lung sections. Transcriptome profiling by RNAseq was performed on the right lung lobes and results were compared with nine independent human gene-expression IPF studies.

RESULTS

The histomorphometric and transcriptomic analyses provided a detailed overview in terms of temporal gene-expression regulation during the establishment and repair of the fibrotic lesions. Moreover, the transcriptomic analysis identified three clusters of differentially coregulated genes whose expression was modulated in a time-dependent manner in response to BLM. One of these clusters, centred on extracellular matrix (ECM)-related process, was significantly correlated with histological parameters and gene sets derived from human IPF studies.

CONCLUSIONS

The model of lung fibrosis presented in this study lends itself as a valuable tool for preclinical efficacy evaluation of new potential drug candidates. The main finding was the identification of a group of persistently dysregulated genes, mostly related to ECM homoeostasis, which are shared with human IPF.

A fibroblastic foci-targeting and hypoxia-cleavable delivery system of pirfenidone for the treatment of idiopathic pulmonary fibrosis

The progressive formation of fibroblastic foci characterizes idiopathic pulmonary fibrosis (IPF), and excessive oral doses of approved pirfenidone (PFD) always cause gastrointestinal side effects. The fibrotic response driven by activated fibroblasts could perpetuate epithelial damage and promote abnormal extracellular matrix (ECM) deposition. When modified nanoparticles reach their target, it is important to ensure a responsive release of PFD. Hypoxia is a determining factor in IPF, leading to alveolar dysfunction and deeper cellular fibrosis. Herein, a fibroblastic foci-targeting and hypoxia-cleavable drug delivery system (Fn-Azo-BSA@PEG) was established to reprogram the fibrosis in IPF. We have modified the FnBAP5 peptide to enable comprehensive fibroblastic foci targeting, which helps BSA nanoparticles recognize and accumulate at fibrotic sites. Meantime, the hypoxia-responsive azobenzene group allowed for efficient and rapid drug diffusion, while the PEGylated BSA reduced system toxicity and increased circulation in vivo. As expected, the strategy of the fibronectin-targeting-modification and hypoxia-responsive drug release synergistically inhibited activated fibroblasts and reduced the secretion of the fibrosis-related protein. Fn-Azo-BSA@PEG could accumulate in pulmonary tissue and prolong the survival time in bleomycin-induced pulmonary fibrosis mice. Together, the multivalent BSA nanoparticles offered an efficient approach for improving lung architecture and function by regulating the fibroblastic foci and hypoxia. STATEMENT OF SIGNIFICANCE: We established fibroblastic foci-targeting and hypoxia-cleavable bovine serum albumin (BSA) nanoparticles (Fn-Azo-BSA@PEG) to reprogramme the fibroblastic foci in idiopathic pulmonary fibrosis (IPF). Fn-Azo-BSA@PEG was designed to actively target fibroblasts and abnormal ECM with the FnBPA5 peptide, delivering more FDA-approved pirfenidone (PFD) to the cross-talk within the foci. Once the drug reached fibroblastic foci, the azobenzene group acted as a hypoxia-responsive linker to trigger effective and rapid drug release. Hypoxic responsiveness and FnBAP5-modification of Fn-Azo-BSA@PEG synergistically inhibited the secretion of proteins closely related to fibrogenesis. BSA's inherent transport and metabolic pathways in the pulmonary reduced the side effects of the main organs. The multivalent BSA nanoparticles efficiently inhibited IPF-fibrosis progress and preserved the lung architecture by regulating the fibroblastic foci and hypoxia.

Inhaled Lipid Nanoparticles Alleviate Established Pulmonary Fibrosis

Pulmonary fibrosis, a sequela of lung injury resulting from severe infection such as severe acute respiratory syndrome-like coronavirus (SARS-CoV-2) infection, is a kind of life-threatening lung disease with limited therapeutic options. Herein, inhalable liposomes encapsulating metformin, a first-line antidiabetic drug that has been reported to effectively reverse pulmonary fibrosis by modulating multiple metabolic pathways, and nintedanib, a well-known antifibrotic drug that has been widely used in the clinic, are developed for pulmonary fibrosis treatment. The composition of liposomes made of neutral, cationic or anionic lipids, and poly(ethylene glycol) (PEG) is optimized by evaluating their retention in the lung after inhalation. Neutral liposomes with suitable PEG shielding are found to be ideal delivery carriers for metformin and nintedanib with significantly prolonged retention in the lung. Moreover, repeated noninvasive aerosol inhalation delivery of metformin and nintedanib loaded liposomes can effectively diminish the development of fibrosis and improve pulmonary function in bleomycin-induced pulmonary fibrosis by promoting myofibroblast deactivation and apoptosis, inhibiting transforming growth factor 1 (TGFβ1) action, suppressing collagen formation, and inducing lipogenic differentiation. Therefore, this work presents a versatile platform with promising clinical translation potential for the noninvasive inhalation delivery of drugs for respiratory disease treatment.

Astragalus polysaccharide attenuates bleomycin-induced pulmonary fibrosis by inhibiting TLR4/ NF-κB signaling pathway and regulating gut microbiota

PURPOSE

Astragalus polysaccharide (APS) is a naturally-occurring compound derived from Astragalus membranaceus with anti-inflammatory and antioxidant properties. However, its beneficial effects and mechanisms on pulmonary fibrosis are unknown. Gut microbiota impact lung diseases via the gut-lung axis. Herein, we investigated APS progression to intervene in pulmonary fibrosis via the toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) signaling pathway and gut microbiota homeostasis regulation.

METHODS

We used bleomycin (BLM) to construct an idiopathic pulmonary fibrosis (IPF) mouse model and assessed the pathology with Masson, hematoxylin-eosin (HE), and Sirius red staining. Enzyme-linked immunosorbent assay (ELISA) kits were employed to evaluate the inflammatory cytokine levels. Western blot evaluated TLR4/NF-κB signaling pathway expression. TUNEL staining to detect apoptosis. Mice feces samples were gathered for 16S rRNA gene sequencing.

RESULTS

Our findings revealed that APS ameliorated the extent of damage and collagen deposition in lung tissues, reduced inflammatory cytokines TNF-α, IL-6, and IL-1β levels, and decreased apoptosis. APS might attenuate the inflammatory response through TLR4/NF-κB signaling pathway inhibition. Meanwhile, the IPF mice model exhibited dysregulation of gut microbiota, and these changes were restored after APS intervention. APS may increase the proportion of probiotics, decrease that of harmful bacteria, and balance the gut microbiota via regulating metabolic pathways.

CONCLUSION

APS ameliorated lung tissue injury in the IPF mice model, inhibited TLR4/NF-κB signaling pathway, suppressed inflammatory cytokines activation, and reduced apoptosis. Moreover, APS regulated the metabolism of gut microbiota besides beneficial bacteria content elevation.

A survival analysis of idiopathic pulmonary fibrosis in the context of antifibrotic therapy in Saudi Arabia

BACKGROUND

The prognosis of idiopathic pulmonary fibrosis (IPF) can be predicted by the gender, age, and physiology (GAP) index. However, antifibrotic therapy (i.e., nintedanib and pirfenidone) may improve survival.

AIMS

This study aimed to compare the outcomes of antifibrotic-treated IPF with the survival predicted by the GAP index.

METHODS

A retrospective cohort study was conducted from March 2014 to January 2020. The electronic health-care records of all IPF patients treated with nintedanib or pirfenidone were reviewed. Besides standard demographic and mortality data, the variables required to calculate the GAP index were also extracted.

RESULTS

Eighty-one patients (male 55, 68%; age 71.4 ± 10.2 years) with IPF received antifibrotic therapy (nintedanib 44.4%; pirfenidone 55.6%; mean follow-up 35 ± 16.5 months). Cumulative mortality (whole cohort 3 years 12%; 4 years 26%; 5 years 33%) was significantly less than predicted by the GAP index.

CONCLUSIONS

The survival of antifibrotic-treated IPF is better than predicted by the GAP index. Novel systems for prognostication are required. The survival benefit from pirfenidone and nintedanib seem similar overall.

Differences in Treatment Response in Bronchial Epithelial Cells from Idiopathic Pulmonary Fibrosis (IPF) Patients: A First Step towards Personalized Medicine?

Idiopathic pulmonary fibrosis (IPF) has a detrimental prognosis despite antifibrotic therapies to which individual responses vary. IPF pathology is associated with oxidative stress, inflammation and increased activation of SRC family kinases (SFK). This pilot study evaluates individual responses to pirfenidone, nintedanib and SFK inhibitor saracatinib, markers of redox homeostasis, fibrosis and inflammation, in IPF-derived human bronchial epithelial (HBE) cells. Differentiated HBE cells from patients with and without IPF were analyzed for potential alterations in redox and profibrotic genes and pro-inflammatory cytokine secretion. Additionally, the effects of pirfenidone, nintedanib and saracatinib on these markers were determined. HBE cells were differentiated into a bronchial epithelium containing ciliated epithelial, basal, goblet and club cells. NOX4 expression was increased in IPF-derived HBE cells but differed on an individual level. In patients with higher NOX4 expression, pirfenidone induced antioxidant gene expression. All drugs significantly decreased NOX4 expression. IL-6 (p = 0.09) and IL-8 secretion (p = 0.014) were increased in IPF-derived HBE cells and significantly reduced by saracatinib. Finally, saracatinib significantly decreased TGF-β gene expression. Our results indicate that treatment responsiveness varies between IPF patients in relation to their oxidative and inflammatory status. Interestingly, saracatinib tends to be more effective in IPF than standard antifibrotic drugs.

Pediatric pulmonology 2021 year in review: Rare and diffuse lung disease

The field of rare and diffuse pediatric lung disease is experiencing rapid progress as diagnostic and therapeutic options continue to expand. In this annual review, we discuss manuscripts published in Pediatric Pulmonology in 2021 in (1) children's interstitial and diffuse lung disease, (2) congenital airway and lung malformations, and (3) noncystic fibrosis bronchiectasis including primary ciliary dyskinesia. These include case reports, descriptive cohorts, trials of therapies, animal model studies, and review articles. The results are put into the context of other literature in the field. Each furthers the field in important ways, while also highlighting the continued need for further studies.

Naringin regulates endoplasmic reticulum stress and mitophagy through the ATF3/PINK1 signaling axis to alleviate pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease that is characterized by abnormal proliferation of fibroblasts and extracellular matrix remodeling, ultimately leading to respiratory insufficiency or even death. Naringin (Nar), a natural compound derived from grapefruit and citrus fruits, has several pharmacological activities that are associated with therapeutic benefits for IPF. However, the specific molecular mechanisms underlying its pulmonary tissue-protective effects remain largely unknown. This study aimed to investigate the effects of Nar on endoplasmic reticulum stress (ERS) and mitophagy. A bleomycin (BLM)-induced mouse model of IPF was established for treatment with different doses of Nar. Histopathological changes in the lung were examined by hematoxylin and eosin (HE) staining and Masson staining. The extent of fibrosis was determined by measuring hydroxyproline and collagen expression levels. The levels of inflammatory cytokines and oxidative stress indicators were determined by Enzyme linked immunosorbent assay (ELISA) and biochemical kits. Western blot and immunofluorescence were used to evaluate the expression levels of the mitophagy-related markers. Cell apoptosis was estimated by western blot and TUNEL staining. Nar reduced the levels of inflammatory response, oxidative stress and decreased the proportion of apoptosis. Nar also inhibited the expression of the ERS and mitophagy-related genes and ERS-downstream proteins, thereby activating transcription factor (ATF) 3 and inhibiting the transcription of PTEN-induced kinase 1 (PINK1). Taken together, Nar is a promising therapeutic agent for treating IPF via inhibiting ERS, reducing apoptosis, and maintaining mitochondrial homeostasis, all of which may be associated with the regulation of the ATF3/PINK1 signaling axis.

Inhaled deep eutectic solvent based-nanoemulsion of pirfenidone in idiopathic pulmonary fibrosis

Pirfenidone (PRF), the first FDA-approved drug to treat idiopathic pulmonary fibrosis (IPF) and formulated as an oral dosage form, has many side effects. To enhance the therapeutic effect, we discovered a high-load nanoemulsion using a novel deep eutectic solvent (DES) and developed an inhalation drug with improved bioavailability. The DES of PRF and N-acetylcysteine were discovered, and their physicochemical properties were evaluated in this study. The mechanism of DES formation was confirmed by FT-IR and ¹H NMR and suggested to involve hydrogen bonding. The DES nanoemulsion in which the nano-sized droplets were dispersed is optimized by mixing the DES and distilled water in a ratio. The in vivo pharmacokinetic study showed that the pulmonary route of administration is superior to that of the oral route, and the DES nanoemulsion is superior to that of the PRF solution in achieving better bioavailability and lung distribution. The therapeutic effect of PRF for IPF could be confirmed through in vivo pharmacodynamics studies, including lung function assessment, enzyme-linked immunosorbent assay, histology, and micro-computed tomography using the bleomycin-induced IPF rat model. In addition, the pulmonary route administration of PRF is advantageous in reducing the toxicity risk.

Lung fibrogenic microenvironment in mouse reconstitutes human alveolar structure and lung tumor

A mesenchymal cell activation is a hallmark event of pulmonary fibrosis. Alveolar type 2 (AT2) cells are progenitor cells that maintain alveolar homeostasis, and their damage is assumed to be an initiating event for pulmonary fibrosis. However, the interaction between the lung fibrogenic microenvironment and AT2 cell dynamics remains to be elucidated. Here, we report a unique role of the lung fibrogenic microenvironment, where cell type-specific tissue reconstruction is achieved by exogenous cell transplantation. We found that in the lung fibrogenic microenvironment the AT2 cell pool was depleted, whereas mesenchymal cells could promote intact AT2 cell proliferation in vitro. Furthermore, exogenously transplanted AT2 cells formed alveolar colonies and ameliorated pulmonary fibrosis. Exogenous tumor cells formed tumor nests with relevant histological and transcriptional properties. Human primary cells were adaptable to this microenvironment, facilitating epithelial cell-targeted therapy in pulmonary fibrosis and the establishment of patient-derived xenografts for precision medicine in lung cancer.

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Severe bleomycin-induced lung injury causes a significant AT2 cell loss

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Mesenchymal cells in the fibrogenic lung supports AT2 cell proliferation

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AT2 cell transplantation ameliorates bleomycin-induced pulmonary fibrosis

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Novel orthotopic lung cancer models are established for patient-derived xenografts

Understanding the cellular interactome of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is reaching epidemic proportions, with a global prevalence of 25% in the adult population. Non-alcoholic steatohepatitis (NASH), which can lead to cirrhosis, has become the leading indication for liver transplantation in both Europe and the USA. Liver fibrosis is the consequence of sustained, iterative liver injury, and the main determinant of outcomes in NASH. The liver possesses remarkable inherent plasticity, and liver fibrosis can regress when the injurious agent is removed, thus providing opportunities to alter long-term outcomes through therapeutic interventions. Although hepatocyte injury is a key driver of NASH, multiple other cell lineages within the hepatic fibrotic niche play major roles in the perpetuation of inflammation, mesenchymal cell activation, extracellular matrix accumulation as well as fibrosis resolution. The constituents of this cellular interactome, and how the various subpopulations within the fibrotic niche interact to drive fibrogenesis is an area of active research. Important cellular components of the fibrotic niche include endothelial cells, macrophages, passaging immune cell populations and myofibroblasts. In this review, we will describe how rapidly evolving technologies such as single-cell genomics, spatial transcriptomics and single-cell ligand-receptor analyses are transforming our understanding of the cellular interactome in NAFLD/NASH, and how this new, high-resolution information is being leveraged to develop rational new therapies for patients with NASH.

Ameliorative Effects of Arctigenin on Pulmonary Fibrosis Induced by Bleomycin via the Antioxidant Activity

In this study, we evaluated the in vivo effect of arctigenin (ATG) on bleomycin-induced pulmonary fibrosis in mice and assessed the role of antioxidant activity. Hematoxylin and eosin (H&E) staining, the results of Masson's trichrome, and Sirius red staining showed that bleomycin induced obvious pathological changes and collagen deposition in the lung tissue of mice, which were effectively inhibited by ATG. Specifically, based on immunohistochemistry and western blot results, ATG inhibited the expression of fibrosis markers, such as collagen, fibronectin, and α-SMA. Moreover, ATG regulated reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) in the lung tissue of pulmonary fibrosis mice and reduced the pressure of oxidative stress. ATG also regulated the TGF-β-induced expression of p-Akt, confirming that ATG can inhibit fibrosis through antioxidant activity modulation.

Therapeutic Effect of Astragali Radix Extract Injection Combined with Bone Marrow Mesenchymal Stem Cells in Bleomycin-Induced Pulmonary Fibrotic Rats

Pulmonary fibrosis is a serious disease for which effective drugs are unavailable. Here, we treated rat models of bleomycin (BLM)-induced pulmonary fibrosis with Astragali Radix extract injection (AI) combined with or without bone marrow mesenchymal stem cells (BMSCs). We injected rats intratracheally with BLM and transplanted BMSCs via tail vein injection 15 days later. We also intraperitoneally injected AI daily from days 15 to 28. Changes in lung pathology and function, as well as the levels of matrix metalloproteinases, collagen, C-X-C motif chemokine ligand 12 (CXCL12), and cluster of differentiation 90 (CD90) were assessed. The results revealed that compared with the BLM group, groups treated with ARE and BMSCs (alone or combined) reduced the expression levels of TGF-β1 and collagens I and III, ameliorated pathological lung fibrotic damage, and improved lung function. The expression levels of MMP-1, MMP-3, and MMP-9 were reduced by either AI or BMSCs alone, whereas those of MMP-3, MMP-9, TIMP-1, CXCL12, and CD90 were elevated by combined AI and BMSCs compared with the BLM group. Overall, these findings demonstrated that AI and BMSCs both can reduce damage caused by PF in rats and that AI altered the expression of chemokines and surface markers in BMSCs.

Contemporary Concise Review 2021: Interstitial lung disease

The last 2 years have presented previously unforeseen challenges in pulmonary medicine. Despite the significant impact of the SARS‐CoV‐2 pandemic on patients, clinicians and communities, advances in the care and understanding of interstitial lung disease (ILD) continued unabated. Recent studies have led to improved guidelines, better understanding of the role for antifibrotics in fibrosing ILDs, prognostic indicators and novel biomarkers. In this concise contemporary review, we summarize many of the important studies published in 2021, highlighting their relevance and impact to the management and knowledge of ILD.

Clinical efficacy of Chinese herbs for supplementing qi and activating blood circulation combined with N-acetylcysteine in the treatment of idiopathic pulmonary fibrosis: A systematic review and network meta-analysis

BACKGROUND

Chinese herbs for supplementing qi and activating blood circulation (CH) combined with N-acetylcysteine (NAC) is widely used for idiopathic pulmonary fibrosis (IPF) in China, but there is a lack of literature to evaluate its efficacy and clinical value.

PURPOSE

This study compared CH + NAC with other treatments by network meta-analysis to clarify its clinical value.

METHODS

Cochrane Library, PubMed, Embase, Web of Science, China National Knowledge Infrastructure, WanFang Data, VIP Database, and China Biology Medicine were searched. Outcomes included lung function (DLCO (%), VC (%), FVC (%), FVC (L)), 6-min walking distance (6MWD), score of St George's respiratory questionnaire (SGRQ), blood gas analysis (PaO2, PaCO2). The data were analyzed by Review Manager 5.4, Stata 12.0 and ADDIS 1.16.5.

RESULTS

23 studies including 1390 patients (702 in intervention group and 688 in control group) were collected to compare 8 outcome indicators among different treatments involving CH, CH+NAC, CH+PFD, NAC, PFD and PFD+NAC on IPF. Network meta-analysis showed that CH was better than NAC in terms of DLCO (%) (MD = 5.14, 95%CI: 1.01 to 8.68) and 6MWD (MD = 49.17, 95%CI: 25.97 to 71.36) as well as PFD + NAC was better than NAC in terms of FVC (L) (MD = -0.56, 95%CI: -0.83 to -0.31). In rankings results, CH + NAC is the best in terms of FVC (%), SGRQ, PaO2 and PaCO2; CH is the best in terms of DLCO (%), VC (%) and 6MWD; CH + PFD is the best in terms of FVC (L).

CONCLUSION

CH related treatments may have advantages in the treatment of IPF and CH + NAC may have clinical application value. However, limited by the quality and quantity of researches included, more rational and scientific randomized controlled trials containing large sample sizes need to be conducted to further verify our conclusions.

Interleukin-19 Aggravates Pulmonary Fibrosis via Activating Fibroblast through TGF-β/Smad Pathway

Background. Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial pneumonia disease with no cure. Communication between injured cells is triggered and maintained by a complicated network of cytokines and their receptors. IL-19 is supported by increasing evidences for a deleterious role in respiratory diseases. However, its potential role in lung fibrosis has never been explored. Methods. Bioinformatic, immunohistochemistry and western blot analysis were used to assess the expression of IL-19 in human and mouse fibrosis lung tissues. CCK-8, transwell and flow cytometry assay were utilized to analyze the effect of IL-19 on biological behaviors of lung fibroblasts. Histopathology was used to elucidate profibrotic effect of IL-19 in vivo. Results. IL-19 was upregulated in fibrosis lung tissues. IL-19 promoted lung fibroblasts proliferation and invasion, inhibited cell apoptosis, and induced differentiation of fibroblasts to the myofibroblast phenotype, which could be revised by LY2109761, a TGF-β/Smad signaling pathway inhibitor. Furthermore, we found that IL-19 aggravated lung fibrosis in murine bleomycin-induced lung fibrosis. Conclusions. Our results imply the profibrotic role for IL-19 through direct effects on lung fibroblasts and the potential of targeting IL-19 for therapeutic intervention in pulmonary fibrosis.

Natural Product-Based Potential Therapeutic Interventions of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a disease-refractive lung condition with an increased rate of mortality. The potential factors causing PF include viral infections, radiation exposure, and toxic airborne chemicals. Idiopathic PF (IPF) is related to pneumonia affecting the elderly and is characterized by recurring scar formation in the lungs. An impaired wound healing process, defined by the dysregulated aggregation of extracellular matrix components, triggers fibrotic scar formation in the lungs. The potential pathogenesis includes oxidative stress, altered cell signaling, inflammation, etc. Nintedanib and pirfenidone have been approved with a conditional endorsement for the management of IPF. In addition, natural product-based treatment strategies have shown promising results in treating PF. In this study, we reviewed the recently published literature and discussed the potential uses of natural products, classified into three types-isolated active compounds, crude extracts of plants, and traditional medicine, consisting of mixtures of different plant products-in treating PF. These natural products are promising in the treatment of PF via inhibiting inflammation, oxidative stress, and endothelial mesenchymal transition, as well as affecting TGF-β-mediated cell signaling, etc. Based on the current review, we have revealed the signaling mechanisms of PF pathogenesis and the potential opportunities offered by natural product-based medicine in treating PF.

Cost-effectiveness of the anti-fibrotics for the treatment of idiopathic pulmonary fibrosis in the United States

BACKGROUND

The anti-fibrotic medications nintedanib and pirfenidone were approved in the United States for use in patients with idiopathic pulmonary fibrosis several years ago. While there is a growing body of evidence surrounding their clinical effectiveness, these medications are quite expensive and no prior cost-effectiveness analysis has been performed in the United States.

METHODS

A previously published Markov model performed in the United Kingdom was replicated using United States data to project the lifetime costs and health benefits of treating idiopathic pulmonary fibrosis with: (1) symptom management; (2) pirfenidone; or (3) nintedanib. For the cost-effectiveness analysis, strategies were ranked by increasing costs and then checked for dominating treatment strategies. Then an incremental cost-effectiveness ratio was calculated for the dominant therapy.

RESULTS

The anti-fibrotic medications were found to cost more than $110,000 per year compared to $12,291 annually for symptom management. While pirfenidone was slightly more expensive than nintedanib and provided the same amount of benefit, neither medication was found to be cost-effective in this U.S.-based analysis, with an average cost of $1.6 million to gain one additional quality-adjusted life year over symptom management.

CONCLUSIONS

Though the anti-fibrotics remain the only effective treatment option for patients with idiopathic pulmonary fibrosis and the data surrounding their clinical effectiveness continues to grow, they are not considered cost-effective treatment strategies in the United States due to their high price.

Assessing and counteracting fibrosis is a cornerstone of the treatment of CKD secondary to systemic and renal limited autoimmune disorders

Chronic kidney disease (CKD) is an increasing cause of morbidity and mortality worldwide. Besides the higher prevalence of diabetes, hypertension and aging worldwide, immune mediated disorders remain an important cause of kidney disease and are especially prevalent in young adults. Regardless of the initial insult, final pathway to CKD and kidney failure is always the loss of normal tissue and fibrosis development, in which the dynamic equilibrium between extracellular matrix synthesis and degradation is disturbed, leading to excessive production and accumulation. During fibrosis, a multitude of cell types intervene at different levels, but myofibroblasts and inflammatory cells are considered critical in the process. They exert their effects through different molecular pathways, of which transforming growth factor β (TGF-β) has demonstrated to be of particular importance. Additionally, CKD itself promotes fibrosis due to the accumulation of toxins and hormonal changes, and proteinuria is simultaneously a manifestation of CKD and a specific driver of renal fibrosis. Pathways involved in renal fibrosis and CKD are closely interrelated, and although important advances have been made in our knowledge of them, it is still necessary to translate them into clinical practice. Given the complexity of this process, it is highly likely that its treatment will require a multi-target strategy to control the origin of the damage but also the mechanisms that perpetuate it. Fortunately, rapid technology development over the last years and new available drugs in the nephrologist's armamentarium give reasons for optimism that more personalized assistance for CKD and renal fibrosis will appear in the future.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.

The effects and safety of pirfenidone in the treatment of idiopathic pulmonary fibrosis: a meta-analysis and systematic review

BACKGROUND

It is necessary to systematically evaluate the efficacy and adverse reactions of pirfenidone in the treatment of patients with idiopathic pulmonary fibrosis (IPF).

METHODS

Pubmed et al. databases were searched up to March 15, 2021 for randomized controlled trials (RCT) of pirfenidone in the treatment of IPF. Two authors collected and compared the indicators including progression-free survival (PFS), vital capacity (VC), forced vital capacity (FVC), and adverse reactions. RevMan 5.3 software and Stata 15.0 software were used for meta-analysis.

RESULTS

A total of 8 reports with 9 RCTs involving 1824 IPF patients were included. Meta-analysis results showed that compared with the control group, pirfenidone could prolong the PFS phase of IPF patients (HR = 0.65, 95% CI 0.55 ~ 0.76, P < 0.001), slow down the VC of IPF patients (SMD = 0.43, 95% CI 0.21 ~ 0.66, P < 0.001), and decrease FVC (SMD = 0.31, 95% CI 0.14 ~ 0.48, P < 0.001). The main adverse reactions of pirfenidone were gastrointestinal reactions, photosensitivity and skin rashes.

CONCLUSION

Pirfenidone is beneficial to prolong the PFS of IPF patients, improve lung function, and it is safe for clinical use. However, more high-quality RCTs are still needed to provide reliable evidence for the treatment of IPF.

Maiwei Yangfei decoction prevents bleomycin-induced pulmonary fibrosis in mice

Maiwei Yangfei (MWYF) is a compound Chinese herb that is safe and effective in the clinical setting in patients with pulmonary fibrosis (PF). The aim of the present study was to assess the role of a (MWYF) decoction in a bleomycin (BLM)-induced PF mouse model and to investigate the underlying functional mechanism. Chemical components within the MWYF decoction were analysed using liquid chromatography-mass spectrometry. A total of 50 C57BL/6 mice were randomly assigned to one of the following five groups with 10 mice per group: Control, model, low dose MWYF (20 g/kg), medium dose MWYF (40 g/kg) and high dose MWYF (60 g/kg). A mouse PF model was established by the tracheal instillation of BLM (5 mg/kg) prior to MWYF treatment, except for mice in the control group. After 21 days of treatment with MWYF, the mice were sacrificed and the body weights were recorded. In addition, pulmonary tissues and bronchial alveolar lavage fluid were collected. TNF-α, IL-6, IL-17, hydroxyproline, pyridinoline and collagen I levels were determined using ELISA. Vimentin, α-smooth muscle actin (α-SMA), fibronectin, TGF-β1, Smad3, TNF-α, IL-6, IL-17, collagen I and collagen III were determined using western blotting. Vimentin and α-SMA levels were also determined using immunofluorescence analysis. Collagens I and III were detected using immunohistochemical analysis and TGF-β1 and Smad3 levels were determined using reverse transcription-quantitative PCR. Following treatment with MWYF decoction, the body weight of the mice in the PF group increased, the degree of pulmonary alveolitis and PF was reduced, collagen levels were reduced and the expression levels of α-SMA, vimentin and fibronectin were decreased. Although both protein and mRNA expression levels of TGF-β1 and Smad3 were reduced, they remained higher than those observed in the control group. To conclude, MWYF decoction delayed the development of BLM-induced PF in mice, where the functional mechanism was likely associated with the TGF-β1/Smad3 signalling pathway.

Human bone marrow-derived mesenchymal stromal cells cultured in serum-free media demonstrate enhanced antifibrotic abilities via prolonged survival and robust regulatory T cell induction in murine bleomycin-induced pulmonary fibrosis

Background

Mesenchymal stromal cells (MSCs) are a potential therapeutic tool for pulmonary fibrosis. However, ex vivo MSC expansion using serum poses risks of harmful immune responses or unknown pathogen infections in the recipients. Therefore, MSCs cultured in serum-free media (SF-MSCs) are ideal for clinical settings; however, their efficacy in pulmonary fibrosis is unknown. Here, we investigated the effects of SF-MSCs on bleomycin-induced pulmonary inflammation and fibrosis compared to those of MSCs cultured in serum-containing media (S-MSCs).

Methods

SF-MSCs and S-MSCs were characterized in vitro using RNA sequence analysis. The in vivo kinetics and efficacy of SF-MSC therapy were investigated using a murine model of bleomycin-induced pulmonary fibrosis. For normally distributed data, Student’s t test and one-way repeated measures analysis of variance followed by post hoc Tukey’s test were used for comparison between two groups and multiple groups, respectively. For non-normally distributed data, Kruskal–Wallis and Mann–Whitney U tests were used for comparison between groups, using e Bonferroni’s correction for multiple comparisons. All tests were two-sided, and P < 0.05 was considered statistically significant.

Results

Serum-free media promoted human bone marrow-derived MSC expansion and improved lung engraftment of intravenously administered MSCs in recipient mice. SF-MSCs inhibited the reduction in serum transforming growth factor-β1 and the increase of interleukin-6 in both the serum and the bronchoalveolar lavage fluid during bleomycin-induced pulmonary fibrosis. SF-MSC administration increased the numbers of regulatory T cells (Tregs) in the blood and lungs more strongly than in S-MSC administration. Furthermore, SF-MSCs demonstrated enhanced antifibrotic effects on bleomycin-induced pulmonary fibrosis, which were diminished by antibody-mediated Treg depletion.

Conclusions

SF-MSCs significantly suppressed BLM-induced pulmonary inflammation and fibrosis through enhanced induction of Tregs into the lungs and corrected the dysregulated cytokine balance. Therefore, SF-MSCs could be a useful tool for preventing pulmonary fibrosis progression without the demerits of serum use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02574-5.

The effect of additional antimicrobial therapy on the outcomes of patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

The effect of additional antimicrobial agents on the clinical outcomes of patients with idiopathic pulmonary fibrosis (IPF) is unclear.

Methods

We performed comprehensive searches of randomized control trials (RCTs) that compared the clinical efficacy of additional antimicrobial agents to those of placebo or usual care in the treatment of IPF patients. The primary outcome was all-cause mortality, and the secondary outcomes were changes in forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO), and the risk of adverse events (AEs).

Results

Four RCTs including a total of 1055 patients (528 receiving additional antibiotics and 527 receiving placebo or usual care) were included in this meta-analysis. Among the study group, 402 and 126 patients received co-trimoxazole and doxycycline, respectively. The all-cause mortality rates were 15.0% (79/528) and 14.0% (74/527) in the patients who did and did not receive additional antibiotics, respectively (odds ratio [OR] 1.07; 95% confidence interval [CI] 0.76 to 1.51; p = 0.71). No significant difference was observed in the changes in FVC (mean difference [MD], 0.01; 95% CI − 0.03 to 0.05; p = 0.56) and DLCO (MD, 0.05; 95% CI − 0.17 to 0.28; p = 0.65). Additional use of antimicrobial agents was also associated with an increased risk of AEs (OR 1.65; 95% CI 1.19 to 2.27; p = 0.002), especially gastrointestinal disorders (OR 1.54; 95% CI 1.10 to 2.15; p = 0.001).

Conclusions

In patients with IPF, adding antimicrobial therapy to usual care did not improve mortality or lung function decline but increased gastrointestinal toxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01839-0.

Computed Tomography Findings Suggestive of Connective Tissue Disease in the Setting of Usual Interstitial Pneumonia

PURPOSE

A usual interstitial pneumonia (UIP) pattern is common in idiopathic pulmonary fibrosis (IPF) and connective tissue disease-related interstitial lung disease (CTD-ILD). The purpose of the study was to validate imaging findings differentiating CTD-ILD from IPF in UIP.

METHODS

Patients with a multidisciplinary diagnosis of CTD-ILD or IPF and a UIP pattern on computed tomography and/or pathology were included in this study. Prevalence of 3 computed tomography findings shown to be associated with CTD-ILD (the straight edge sign [SES], the exuberant honeycombing sign, and the anterior upper lobe sign [AULS]) were tabulated in CTD-ILD and IPF subjects. The ability of each of these signs to discriminate between CTD-ILD and IPF was evaluated. Survival analysis was also performed using log-rank analysis.

RESULTS

The study cohort included 50 CTD-ILD and 100 IPF subjects with UIP. The SES and the AULS were more common in CTD-ILD than IPF (prevalence, 36.0% and 34.9% in CTD-ILD vs 8.3% and 17.2% in IPF, respectively [P = 0.0105 - <0.001]). The highest specificity (95.7%) of CTD-ILD diagnosis was seen with bilateral SES. Moreover, the SES was associated with improved survival (P = 0.0383), which appeared to be largely because of improvement in survival in IPF subjects. The presence of AULS was associated with pulmonary functional abnormalities.

CONCLUSIONS

A radiographic UIP pattern with evidence of SES or the AULS should raise suspicion for CTD-ILD rather than IPF. Patients with IPF and SES have an attenuated disease course and might represent a different phenotype than those without the SES.

Toll-Interacting Protein in Pulmonary Diseases. Abiding by the Goldilocks Principle

TOLLIP (Toll-interacting protein) is an intracellular adaptor protein with diverse actions throughout the body. In a context- and cell type–specific manner, TOLLIP can function as an inhibitor of inflammation and endoplasmic-reticulum stress, an activator of autophagy, or a critical regulator of intracellular vacuole trafficking. The distinct functions of this protein have been linked to innate immune responses and lung epithelial-cell apoptosis. TOLLIP genetic variants have been associated with a variety of chronic lung diseases, including idiopathic pulmonary fibrosis, asthma, and primary graft dysfunction after lung transplantation, and with infections, such as tuberculosis, Legionella pneumonia, and respiratory viruses. TOLLIP exists in a delicate homeostatic balance, with both positive and negative effects on the trajectory of pulmonary diseases. This translational review summarizes the genetic and molecular associations that link TOLLIP to the development and progression of noninfectious and infectious pulmonary diseases. We highlight current limitations of in vitro and in vivo models in assessing the role of TOLLIP in these conditions, and we describe future approaches that will enable a more nuanced exploration of the role of TOLLIP in pulmonary conditions. There has been a surge in recent research evaluating the role of this protein in human diseases, but critical mechanistic pathways require further exploration. By understanding its biologic functions in disease-specific contexts, we will be able to determine whether TOLLIP can be therapeutically modulated to treat pulmonary diseases.

Signaling Pathways Involved in Diabetic Renal Fibrosis

Diabetic kidney disease (DKD), as the most common complication of diabetes mellitus (DM), is the major cause of end-stage renal disease (ESRD). Renal interstitial fibrosis is a crucial metabolic change in the late stage of DKD, which is always considered to be complex and irreversible. In this review, we discuss the pathological mechanisms of diabetic renal fibrosis and discussed some signaling pathways that are closely related to it, such as the TGF-β, MAPK, Wnt/β-catenin, PI3K/Akt, JAK/STAT, and Notch pathways. The cross-talks among these pathways were then discussed to elucidate the complicated cascade behind the tubulointerstitial fibrosis. Finally, we summarized the new drugs with potential therapeutic effects on renal fibrosis and listed related clinical trials. The purpose of this review is to elucidate the mechanisms and related pathways of renal fibrosis in DKD and to provide novel therapeutic intervention insights for clinical research to delay the progression of renal fibrosis.

Network Pharmacology-Based Mechanistic Investigation of Jinshui Huanxian Formula Acting on Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic respiratory disease with high incidence, morbidity, and mortality rates. Jinshui Huanxian formula (JHF) is an empirical formula that targets the pathogenesis of lung-kidney qi deficiency and phlegm-blood stasis in pulmonary fibrosis (PF). The purpose of this study was to explore JHF's potential pharmacological mechanisms in IPF therapy using network intersection analysis. JHF's primary active components and corresponding target genes were predicted using various databases. Two sets of IPF disease genes were obtained from the DisGeNET and GEO databases and two sets of IPF drug targets were collected. The disease and drug target genes were analyzed. The JHF target genes that intersected with IPF's differentially expressed genes were identified to predict JHF's targets of action in IPF. The functions and pathways of predicted targets acting on IPF were analyzed using the DAVID and KEGG pathway databases. Finally, the resulting drug target mechanisms were validated in a rat model of PF. The initial analyses identified 494 active compounds and 1,304 corresponding targets for JHF. The intersection analysis revealed four common genes for the JHF targets, IPF disease, and anti-IPF drugs in the KEGG database. Furthermore, these genes were targeted by several JHF compounds. Seventy-two JHF targets were closely related to IPF, which suggests that they are therapeutically relevant. Target screening revealed that they regulate IPF through 18 pathways. The targets' molecular functions included regulation of oxidoreductase activity, kinase regulator activity, phosphotransferase activity, and transmembrane receptor protein kinase activity. In vivo experiments showed that JHF alleviated the degree of PF, including decreases in collagen deposition and epithelial-mesenchymal transition. This study systematically explored JHF's mechanisms to identify the specific target pathways involved in IPF. The generated pharmacological network, paired with in vivo validation, elucidates the potential roles and mechanisms of JHF in IPF therapy.

Effect of a Patient Support Program for Idiopathic Pulmonary Fibrosis Patients on Medication Persistence: A Retrospective Database Analysis

INTRODUCTION

In 2015, Boehringer Ingelheim (BI) created a support program for patients with idiopathic pulmonary fibrosis (IPF) treated with nintedanib, to help patients obtain their prescription, learn about their disease and medication, and provide support in the management of their IPF. The purpose of this study was to measure the impact of the program on nintedanib persistence among patients with IPF newly treated with the medication.

METHODS

A retrospective cohort analysis of BI Pharmaceuticals, Inc.'s Specialty Pharmacy (SP) database was conducted. Patients at least 18 years of age, newly treated with nintedanib from April 1, 2015 to January 31, 2018, and with at least one diagnosis of IPF were included in the study; earliest nintedanib prescription was the index date. Patients were classified into two mutually exclusive cohorts: enrolled in the patient support program within 60 days of index or not enrolled in the program at any time. The cohorts were compared in terms of patient characteristics, time to nintedanib discontinuation (a gap of more than 60 days between refills), and proportion of persistent patients at 6, 12, 18, and 24 months after index. Time to discontinuation was compared between the cohorts using Kaplan-Meier analysis. A multivariable Cox proportional hazards model assessed the impact of program participation on time to discontinuation within the first 12 months.

RESULTS

A total of 3114 enrolled and 9388 non-enrolled patients were identified. The proportion of patients persistent on nintedanib was higher among enrolled patients throughout the post-index period (57.8% vs. 49.7% at 6 months, 34.7% vs. 28.9% at 12 months; p < 0.05). In adjusted analyses, being enrolled in the program was associated with a 21% decreased hazard of discontinuing nintedanib over the first-year post-index [hazard ratio (HR) = 0.79, 95% CI 0.75-0.83, p < 0.05).

CONCLUSION

Real-world evidence suggests a persistence benefit for patients with IPF treated with nintedanib who are enrolled in the patient support program.

Ground glass and fibrotic change in children with surfactant protein C dysfunction mutations

INTRODUCTION

Therapeutics exist to treat fibrotic lung disease in adults, but these have not been investigated in children. Defining biomarkers for pediatric fibrotic lung disease in children is crucial for clinical trials. Children with surfactant protein C (SFTPC) dysfunction mutations develop fibrotic lung disease over time. We evaluated chest computed tomography (CT) changes over time in children with SFTPC dysfunction mutations.

METHODS

We performed an institutional review board-approved retrospective review of children with SFTPC dysfunction mutations. We collected demographic and clinical information. Chest CT scans were evaluated using visual and computerized scores. Chest CT scores and pulmonary function tests were reviewed.

RESULTS

Eleven children were included. All children presented in infancy and four children suffered from respiratory failure requiring mechanical ventilation. Those who performed pulmonary function tests had stable forced vital capacities over time by percent predicted, but increased forced vital capacity in liters. CT findings evolved over time in most patients with earlier CT scans demonstrating ground glass opacities and later CT scans with more fibrotic features. In a pilot analysis, data-driven textural analysis software identified fibrotic features in children with SFTPC dysfunction that increased over time and correlated with visual CT scores.

DISCUSSION

We describe 11 children with SFTPC dysfunction mutations. Increases in forced vital capacity over time suggest that these children experience lung growth and that therapeutic intervention may maximize lung growth. Ground glass opacities are the primary early imaging findings while fibrotic features dominate later. CT findings suggest the development of and increases in fibrotic features that may serve as potential biomarkers for antifibrotic therapeutic trials.

N-Acetylcysteine (NAC): Impacts on Human Health

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC's relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.