Idiopathic pulmonary fibrosis

Perceptions on Use of Opioids in Palliative Care of Dyspnoea in Patients with Fibrotic interstitial lung disease and Chronic Obstructive Pulmonary Disease: A Qualitative Study

BACKGROUND

Many patients with chronic obstructive pulmonary disease and fibrotic interstitial lung disease suffer from severe dyspnea and reduced quality of life, despite receiving optimal disease-modifying treatment for their illness. Studies have suggested that these patients may benefit from treatment with low-dose opioids. However, many patients decline opioid treatment. This has led to patients not receiving proper palliative treatment of their lung disease.

AIM

To identify potential barriers that prevent patients from receiving adequate palliative care with opioids and enable doctors to address patients' concerns.

DESIGN

A qualitative study based on semi-structured interviews. Interviews were transcribed and thematic analysis was done using NVivo.

SETTING/PARTICIPANTS

Patients were recruited when scheduled for out-patient follow-up at Center for Rare Lung Diseases or at the COPD clinic, Aarhus University Hospital. Eligible patients were 18 years of age, did not currently receive opioids or had ever received opioids for dyspnea.

RESULTS

A total of 28 patients participated. One patient was excluded before final analysis of 27 patients. Four themes were identified: Fear of side-effects, Need for more information, Stigma of opioids association with severe illness and dying, and No discernible barriers. Furthermore, three sub-themes to Fear of side-effects were identified: Fear of addiction, concern for sedative effect, and fear for loss of mobility due to inability to drive a car. The most expressed concern was Fear of side-effects, especially addiction.

CONCLUSIONS

Pre-conceived notions about opioids prevent some patients with chronic obstructive lung disease or interstitial lung disease from receiving palliative care for breathlessness.

A Novel Non-Rodent Animal Model of Hydrochloric Acid-Induced acute and chronic lung injury

Hydrochloric acid is one of the most prevalent and dangerous chemicals. Accidental spills occur in industrial plants or during transportation. Exposure to HCl can induce severe health impairment, including acute and chronic pulmonary diseases. We have previously described the molecular, structural, and functional aspects of the development of chronic lung injury and pulmonary fibrosis caused by intratracheal instillation of HCl in mice. Although mouse models of human disease have many advantages, rodents are evolutionary far from human and exhibit significant anatomical and physiological differences. Genetic and anatomic similarities between rabbits and humans are significantly higher. Rabbit models of HCl-induced lung injury have been used sparsely to evaluate acute lung injury. In this study, for the first time, we utilized rabbits as a model of HCl-induced pulmonary fibrosis and chronic lung injury. We present molecular, histological, and functional evidence that demonstrate the utility of using this model for studying new pharmaceutics against pulmonary fibrosis.

Advanced Delivery Strategies of Nintedanib for Lung Disorders and Beyond: A Comprehensive Review

Nintedanib, a primary treatment for lung fibrosis, has gathered substantial attention due to its multifaceted potential. A tyrosine kinase inhibitor, nintedanib, inhibits multiple signalling receptors, including endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR) and ultimately inhibits fibroblast proliferation and differentiation. Therefore, nintedanib has been studied widely for other ailments like cancers and hepatic fibrosis, apart from lung disorders. Commercially, nintedanib is available as soft gelatin capsules for treatment against idiopathic pulmonary fibrosis. Since it has very low oral bioavailability (4.7%), high doses of a drug, such as 100-150 mg, are administered, which can cause problems of gastrointestinal irritation and hepatotoxicity. The article begins with exploring the mechanism of action of nintedanib, elucidating its complex interactions within cellular pathways that govern fibrotic processes. It also emphasizes the pharmacokinetics of nintedanib, clinical trial insights, and the limitations of conventional formulations. The article mainly focuses on the emerging landscape of nanoparticle-based carriers such as hybrid liposome-exosome, nano liquid crystals, discoidal polymeric, and magnetic systems, offering promising avenues to optimize drug targeting, address its efficacy issues and minimise adverse effects. However, none of these delivery systems are commercialised, and further research is required to ensure safety and effectiveness in clinical settings. Yet, as research progresses, these advanced delivery systems promise to revolutionise the treatment landscape for various fibrotic disorders and cancers, potentially improving patient outcomes and quality of life.

Experiences of living with idiopathic pulmonary fibrosis in relation to physical activity - "How the hills became steeper and steeper": a qualitative interview study

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a progressive disease presenting with symptoms like dyspnoea, dry cough, and fatigue, which affect physical function and quality of life. No earlier qualitative studies have investigated physical activity in IPF. This study aims to explore experiences of living with IPF in relation to physical activity.

MATERIALS AND METHODS

Qualitative interviews were conducted with 14 participants living with IPF. The participants were 77 years old (range: 56-86) and diagnosed with IPF between 2 and 9 years ago. The analysis was performed by qualitative content analysis according to Graneheim and Lundman.

RESULTS

The results indicated that life and one's ability to be physically active is affected by IPF. Despite this, it seems possible to navigate past obstacles, which was illustrated by an overall theme: "My life is constrained, but I am hanging on". Two major categories cover topics of IPF being a life changing diagnosis with changes in self-image and changed future plans regarding physical activity, as well as life. Physical activity was perceived to be challenging, yet in many ways used as a strategy, developed to manage life.

CONCLUSIONS

IPF affects physical activity as well as life, from onset onwards. By developing strategies for facilitating physical activity as well as identifying barriers, it seems possible to maintain an active life despite the disease. The healthcare system needs to create support systems that meet different needs during different phases of the disease.

TRIAL REGISTRATION

"FoU in Sweden" Research and Development in Sweden (id: 227081).

Lipid-Laden Macrophages in Pulmonary Diseases

Pulmonary surfactants play a crucial role in managing lung lipid metabolism, and dysregulation of this process is evident in various lung diseases. Alternations in lipid metabolism lead to pulmonary surfactant damage, resulting in hyperlipidemia in response to lung injury. Lung macrophages are responsible for recycling damaged lipid droplets to maintain lipid homeostasis. The inflammatory response triggered by external stimuli such as cigarette smoke, bleomycin, and bacteria can interfere with this process, resulting in the formation of lipid-laden macrophages (LLMs), also known as foamy macrophages. Recent studies have highlighted the potential significance of LLM formation in a range of pulmonary diseases. Furthermore, growing evidence suggests that LLMs are present in patients suffering from various pulmonary conditions. In this review, we summarize the essential metabolic and signaling pathways driving the LLM formation in chronic obstructive pulmonary disease, pulmonary fibrosis, tuberculosis, and acute lung injury.

Preclinical evidence using synthetic compounds and natural products indicates that AMPK represents a potential pharmacological target for the therapy of pulmonary diseases

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a highly conserved eukaryotic enzyme discovered as a key regulator of cellular energy homeostasis, with anti-inflammation, antioxidative stress, anticancer, and antifibrosis beneficial effects. AMPK is dysregulated in human pulmonary diseases such as acute lung injury, nonsmall cell lung cancer, pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. This review provides an overview of the beneficial role of natural, synthetic, and Chinese traditional medicines AMPK modulators in pulmonary diseases, and highlights the role of the AMPK signaling pathway in the lung, emphasizing the importance of finding lead compounds and drugs that can target and modulate AMPK to treat the lung diseases.

NR2F2 alleviates pulmonary fibrosis by inhibition of epithelial cell senescence

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fatal, and aging-associated interstitial lung disease with a poor prognosis and limited treatment options, while the pathogenesis remains elusive. In this study, we found that the expression of nuclear receptor subfamily 2 group F member 2 (NR2F2), a member of the steroid thyroid hormone superfamily of nuclear receptors, was reduced in both IPF and bleomycin-induced fibrotic lungs, markedly in bleomycin-induced senescent epithelial cells. Inhibition of NR2F2 expression increased the expression of senescence markers such as p21 and p16 in lung epithelial cells, and activated fibroblasts through epithelial-mesenchymal crosstalk, inversely overexpression of NR2F2 alleviated bleomycin-induced epithelial cell senescence and inhibited fibroblast activation. Subsequent mechanistic studies revealed that overexpression of NR2F2 alleviated DNA damage in lung epithelial cells and inhibited cell senescence. Adenovirus-mediated Nr2f2 overexpression attenuated bleomycin-induced lung fibrosis and cell senescence in mice. In summary, these data demonstrate that NR2F2 is involved in lung epithelial cell senescence, and targeting NR2F2 may be a promising therapeutic approach against lung cell senescence and fibrosis.

Time course of histopathology of bleomycin-induced pulmonary fibrosis using an intratracheal sprayer in mice

Idiopathic pulmonary fibrosis (IPF) is a poor prognosis disease that affects approximately 5 million people worldwide, and the detailed mechanisms underlying the pathogenesis of IPF remain unclear. Bleomycin-induced pulmonary fibrosis has been widely used as a representative animal model of IPF that induces fibrosis in lung tissue. The lungs of rodent consist of five lobes and each bronchus enters each lobe of the lung at a different bifurcation angle, path length, and diameter. The method of administration of bleomycin is considered as important thing to establish appropriate animal models. We conducted a time-dependent histopathological study to examine how pulmonary fibrosis develops in each lung lobe when bleomycin was intratracheally sprayed in ICR mice. And we then explored the suitable points for evaluation of anti-fibrotic agents in this model. As a result, we found that homogeneous fibrosis was induced in the 5 lobes of the lungs following initial inflammation. The expression of transforming growth factor (TGF)-β1 and phospho-Smad2 (pSmad2) was observed from Day 1, and their positivity increased until Day 21. In conclusion, we have observed a detailed time course of histological changes in bleomycin-induced pulmonary fibrosis in ICR mice using the aerosolization technique. We found that our protocol can induce a highly homogeneous lesion in the lung and that the most suitable time point to assess anti-fibrotic agents is 14 days after treatment in this model.

CD36/Lyn kinase interactions within macrophages promotes pulmonary fibrosis in response to oxidized phospholipid

Recent data from human studies and animal models have established roles for type II alveolar epithelial cell (AEC2) injury/apoptosis and monocyte/macrophage accumulation and activation in progressive lung fibrosis. Although the link between these processes is not well defined, we have previously shown that CD36-mediated uptake of apoptotic AEC2s by lung macrophages is sufficient to drive fibrosis. Importantly, apoptotic AEC2s are rich in oxidized phospholipids (oxPL), and amongst its multiple functions, CD36 serves as a scavenger receptor for oxPL. Recent studies have established a role for oxPLs in alveolar scarring, and we hypothesized that uptake and accrual of oxPL by CD36 would cause a macrophage phenotypic change that promotes fibrosis. To test this hypothesis, we treated wild-type and CD36-null mice with the oxPL derivative oxidized phosphocholine (POVPC) and found that CD36-null mice were protected from oxPL-induced scarring. Compared to WT mice, fewer macrophages accumulated in the lungs of CD36-null animals, and the macrophages exhibited a decreased accumulation of intracellular oxidized lipid. Importantly, the attenuated accrual of oxPL in CD36-null macrophages was associated with diminished expression of the profibrotic mediator, TGFβ. Finally, the pathway linking oxPL uptake and TGFβ expression was found to require CD36-mediated activation of Lyn kinase. Together, these observations elucidate a causal pathway that connects AEC2 injury with lung macrophage activation via CD36-mediated uptake of oxPL and suggest several potential therapeutic targets.

TANGO1 Dances to Export of Procollagen from the Endoplasmic Reticulum

The endoplasmic reticulum (ER) to Golgi secretory pathway is an elegantly complex process whereby protein cargoes are manufactured, folded, and distributed from the ER to the cisternal layers of the Golgi stack before they are delivered to their final destinations. The export of large bulky cargoes such as procollagen and its trafficking to the Golgi is a sophisticated mechanism requiring TANGO1 (Transport ANd Golgi Organization protein 1. It is also called MIA3 (Melanoma Inhibitory Activity protein 3). TANGO1 has two prominent isoforms, TANGO1-Long and TANGO1-Short, and each isoform has specific functions. On the luminal side, TANGO1-Long has an HSP47 recruitment domain and uses this protein to collect collagen. It can also tether its paralog isoforms cTAGE5 and TALI and along with these proteins enlarges the vesicle to accommodate procollagen. Recent studies show that TANGO1-Long combines retrograde membrane flow with anterograde cargo transport. This complex mechanism is highly activated in fibrosis and promotes the excessive deposition of collagen in the tissues. The therapeutic targeting of TANGO1 may prove successful in the control of fibrotic disorders. This review focuses on TANGO1 and its complex interaction with other procollagen export factors that modulate increased vesicle size to accommodate the export of procollagen.

Multi-omics analysis reveals the mechanism of action of ophiopogonin D against pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with limited therapeutic strategies. Therefore, there is an urgent need to search for safe and effective drugs to treat this condition. Ophiopogonin D (OP-D), a steroidal saponin compound extracted from ophiopogon, possesses various pharmacological properties, including anti-inflammatory, antioxidant, and antitumor effects. However, the potential pharmacological effect of OP-D on pulmonary fibrosis remains unknown.

PURPOSE

The aim of this study was to investigate whether OP-D can improve pulmonary fibrosis and to explore its mechanism of action.

METHODS

The effect of OP-D on pulmonary fibrosis was investigated in vitro and in vivo using a mouse model of IPF induced by bleomycin and an in vitro model of human embryonic lung fibroblasts induced by transforming growth factor-β1 (TGF-β1). The mechanism of action of OP-D was determined using multi-omics techniques and bioinformatics.

RESULTS

OP-D attenuated epithelial-mesenchymal transition and excessive deposition of extracellular matrix in the lungs, promoted the apoptosis of lung fibroblasts, and blocked the differentiation of lung fibroblasts into myofibroblasts. The multi-omics techniques and bioinformatics analysis revealed that OP-D blocked the AKT/GSK3β pathway, and the combination of a PI3K/AKT inhibitor and OP-D was effective in alleviating pulmonary fibrosis.

CONCLUSION

This study demonstrated for the first time that OP-D can reduce lung inflammation and fibrosis. OP-D is thus a potential new drug for the prevention and treatment of pulmonary fibrosis.

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

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

Searching for Novel Candidate Small Molecules for Ameliorating Idiopathic Pulmonary Fibrosis: a Narrative Review

Idiopathic pulmonary fibrosis (IPF) can be defined as a progressive chronic pulmonary disease showing scarring in the lung parenchyma, thereby resulting in increase in mortality and decrease in the quality of life. The pathophysiologic mechanism of fibrosis in IPF is still unclear. Repetitive microinjuries to alveolar epithelium with genetical predisposition and an abnormal restorative reaction accompanied by excessive deposition of collagens are involved in the pathogenesis. Although the two FDA-approved drugs, pirfenidone and nintedanib, are under use for retarding the decline in lung function of patients suffered from IPF, they are not able to improve the survival rate or quality of life. Therefore, a novel therapeutic agent acting on the major steps of the pathogenesis of disease and/or, at least, managing the clinical symptoms of IPF should be developed for the effective regulation of this incurable disease. In the present review, we tried to find a potential of managing the clinical symptoms of IPF by natural products derived from medicinal plants used for controlling the pulmonary inflammatory diseases in traditional Asian medicine. A multitude of natural products have been reported to exert an antifibrotic effect in vitro and in vivo through acting on the epithelial-mesenchymal transition pathway, transforming growth factor (TGF)-β-induced intracellular signaling, and the deposition of extracellular matrix. However, clinical antifibrotic efficacy of these natural products on IPF have not been elucidated yet. Thus, those effects should be proven by further examinations including the randomized clinical trials, in order to develop the ideal and optimal candidate for the therapeutics of IPF.

A roadmap for developing and engineering in vitro pulmonary fibrosis models

Idiopathic pulmonary fibrosis (IPF) is a severe form of pulmonary fibrosis. IPF is a fatal disease with no cure and is challenging to diagnose. Unfortunately, due to the elusive etiology of IPF and a late diagnosis, there are no cures for IPF. Two FDA-approved drugs for IPF, nintedanib and pirfenidone, slow the progression of the disease, yet fail to cure or reverse it. Furthermore, most animal models have been unable to completely recapitulate the physiology of human IPF, resulting in the failure of many drug candidates in preclinical studies. In the last few decades, the development of new IPF drugs focused on changes at the cellular level, as it was believed that the cells were the main players in IPF development and progression. However, recent studies have shed light on the critical role of the extracellular matrix (ECM) in IPF development, where the ECM communicates with cells and initiates a positive feedback loop to promote fibrotic processes. Stemming from this shift in the understanding of fibrosis, there is a need to develop in vitro model systems that mimic the human lung microenvironment to better understand how biochemical and biomechanical cues drive fibrotic processes in IPF. However, current in vitro cell culture platforms, which may include substrates with different stiffness or natural hydrogels, have shortcomings in recapitulating the complexity of fibrosis. This review aims to draw a roadmap for developing advanced in vitro pulmonary fibrosis models, which can be leveraged to understand better different mechanisms involved in IPF and develop drug candidates with improved efficacy. We begin with a brief overview defining pulmonary fibrosis and highlight the importance of ECM components in the disease progression. We focus on fibroblasts and myofibroblasts in the context of ECM biology and fibrotic processes, as most conventional advanced in vitro models of pulmonary fibrosis use these cell types. We transition to discussing the parameters of the 3D microenvironment that are relevant in pulmonary fibrosis progression. Finally, the review ends by summarizing the state of the art in the field and future directions.

Bioactive lipid lysophosphatidic acid species are associated with disease progression in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with significant mortality. Prognostic biomarkers to identify rapid progressors are urgently needed to improve patient management. Since the lysophosphatidic acid (LPA) pathway has been implicated in lung fibrosis in preclinical models and identified as a potential therapeutic target, we aimed to investigate if bioactive lipid LPA species could be prognostic biomarkers that predict IPF disease progression. LPAs and lipidomics were measured in baseline placebo plasma of a randomized IPF-controlled trial. The association of lipids with disease progression indices were assessed using statistical models. Compared to healthy, IPF patients had significantly higher levels of five LPAs (LPA16:0, 16:1, 18:1, 18:2, 20:4) and reduced levels of two triglycerides species (TAG48:4-FA12:0, -FA18:2) (false discovery rate < 0.05, fold change > 2). Patients with higher levels of LPAs had greater declines in diffusion capacity of carbon monoxide over 52 weeks (P < 0.01); additionally, LPA20:4-high (≥median) patients had earlier time to exacerbation compared to LPA20:4-low ( Collapse

Key Words

• DLCO
• Lysophosphatidic acid
• exacerbation
• idiopathic pulmonary fibrosis
• mortality

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MESH Headings

• Humans
• Idiopathic Pulmonary Fibrosis/metabolism
• Disease Progression
• Lysophospholipids
• Biomarkers

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Affiliation(s)

Margaret Neighbors OMNI Translational Medicine, Genentech Inc., South San Francisco, USA
Qingling Li Department of Microchemistry, Proteomics & Lipidomics, Genentech Inc., South San Francisco, USA
Sha Joe Zhu PD Data Science, F Hoffmann-La Roche, Shanghai, China
Jia Liu PD Data Science, F Hoffmann-La Roche, Shanghai, China
Weng Ruh Wong Department of Microchemistry, Proteomics & Lipidomics, Genentech Inc., South San Francisco, USA
Guiquan Jia Department of Biomarker Discovery OMNI, Genentech Inc., South San Francisco, USA
Wendy Sandoval Department of Microchemistry, Proteomics & Lipidomics, Genentech Inc., South San Francisco, USA
Gaik W Tew I2O Technology and Translational Research, Genentech Inc., South San Francisco, USA.

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Hyperpolarized Xenon-129: A New Tool to Assess Pulmonary Physiology in Patients with Pulmonary Fibrosis

PURPOSE

The existing tools to quantify lung function in interstitial lung diseases have significant limitations. Lung MRI imaging using inhaled hyperpolarized xenon-129 gas (129Xe) as a contrast agent is a new technology for measuring regional lung physiology. We sought to assess the utility of the 129Xe MRI in detecting impaired lung physiology in usual interstitial pneumonia (UIP).

MATERIALS AND METHODS

After institutional review board approval and informed consent and in compliance with HIPAA regulations, we performed chest CT, pulmonary function tests (PFTs), and 129Xe MRI in 10 UIP subjects and 10 healthy controls.

RESULTS

The 129Xe MRI detected highly heterogeneous abnormalities within individual UIP subjects as compared to controls. Subjects with UIP had markedly impaired ventilation (ventilation defect fraction: UIP: 30 ± 9%; healthy: 21 ± 9%; p = 0.026), a greater amount of 129Xe dissolved in the lung interstitium (tissue-to-gas ratio: UIP: 1.45 ± 0.35%; healthy: 1.10 ± 0.17%; p = 0.014), and impaired 129Xe diffusion into the blood (RBC-to-tissue ratio: UIP: 0.20 ± 0.06; healthy: 0.28 ± 0.05; p = 0.004). Most MRI variables had no correlation with the CT and PFT measurements. The elevated level of 129Xe dissolved in the lung interstitium, in particular, was detectable even in subjects with normal or mildly impaired PFTs, suggesting that this measurement may represent a new method for detecting early fibrosis.

CONCLUSION

The hyperpolarized 129Xe MRI was highly sensitive to regional functional changes in subjects with UIP and may represent a new tool for understanding the pathophysiology, monitoring the progression, and assessing the effectiveness of treatment in UIP.

Isolation, Characterization, and Anti-Idiopathic Pulmonary Fibrosis Activity of a Fucoidan from Costaria costata

Pulmonary fibrosis is a chronic, progressive, and fatal disease of the interstitial lung. There is currently a lack of efficient therapy to reverse the prognosis of patients. In this study, a fucoidan from Costaria costata was isolated, and its anti-idiopathic fibrosis activity was investigated both in vitro and in vivo. The chemical composition analysis showed that C. costata polysaccharide (CCP) consists of galactose and fucose as the main monosaccharides with a sulfate group content of 18.54%. Further study found that CCP could resist TGF-β1-induced epithelial-mesenchymal transition (EMT) in A549 cells by inhibiting the TGF-β/Smad and PI3K/AKT/mTOR signaling pathways. Moreover, in vivo study found that CCP treatment alleviated bleomycin (BLM)-stimulated fibrosis and inflammation in mice lung tissue. In conclusion, the present study suggests that CCP could protect the lung from fibrosis by relieving the EMT process and inflammation in lung cells.

Towards a Unified Approach in Autoimmune Fibrotic Signalling Pathways

Autoimmunity is a chronic process resulting in inflammation, tissue damage, and subsequent tissue remodelling and organ fibrosis. In contrast to acute inflammatory reactions, pathogenic fibrosis typically results from the chronic inflammatory reactions characterizing autoimmune diseases. Despite having obvious aetiological and clinical outcome distinctions, most chronic autoimmune fibrotic disorders have in common a persistent and sustained production of growth factors, proteolytic enzymes, angiogenic factors, and fibrogenic cytokines, which together stimulate the deposition of connective tissue elements or epithelial to mesenchymal transformation (EMT) that progressively remodels and destroys normal tissue architecture leading to organ failure. Despite its enormous impact on human health, there are currently no approved treatments that directly target the molecular mechanisms of fibrosis. The primary goal of this review is to discuss the most recent identified mechanisms of chronic autoimmune diseases characterized by a fibrotic evolution with the aim to identify possible common and unique mechanisms of fibrogenesis that might be exploited in the development of effective antifibrotic therapies.

PM2.5 promotes pulmonary fibrosis by mitochondrial dysfunction

Pulmonary fibrosis is known as an incurable lung disorder with irreversible progression of chronic injury, myofibroblast proliferation, extracellular matrix (ECM) accumulation, and tissue scarring. Atmospheric particulate matter 2.5 (PM_2.5 ) is implicated as a risk factor of several diseases, especially lung diseases such as pulmonary fibrosis. The molecular mechanism which participates PM_2.5 -induced pulmonary fibrosis in type II alveolar cells (AEII) has yet to be determined. Our results proved that short- and long-term exposure to PM_2.5 significantly stimulated epithelial-mesenchymal transition (EMT) activity in AEII cells, according to, changes in gene signature analyzed by RNA-seq and cell morphology. Furthermore, Gene Ontology (GO) enrichment analysis also suggested that mitochondrial dysfunction was related to progression of pulmonary fibrosis in AEII after PM_2.5 exposure. We observed a marked decline in mitochondria membrane potential (MMP), as well as fragmented mitochondria, in AEII cells exposed to PM_2.5 , which suggests that energy metabolism is suppressed after PM_2.5 exposure. We also confirmed that PM_2.5 exposure could influence the expression levels of Mfn1, Mfn2, and Drp1 in AEII. Pretreatment of mitochondrial fusion promoter M1 was able to reverse mitochondrial dysfunction as well as EMT in AEII. These data suggested the key role of mitochondrial fragmentation in AEII, which was induced by PM_2.5 exposure, and participated pathogenesis of pulmonary fibrosis. Finally, we investigated the response of lung tissue exposed to PM_2.5 in vivo. The data indicated that the lung tissue exposed to PM_2.5 obviously induced collagen accumulation. Moreover, IHC results revealed that PM_2.5 enhanced Drp1 expression but suppressed Mfn1 and Mfn2 expression in lung tissue. The current study provides novel insight of pulmonary fibrosis caused by PM_2.5 exposure.

Idiopathic Pulmonary Fibrosis Is Associated with Common Genetic Variants and Limited Rare Variants

Rationale: Idiopathic pulmonary fibrosis (IPF) is a rare, irreversible, and progressive disease of the lungs. Common genetic variants, in addition to nongenetic factors, have been consistently associated with IPF. Rare variants identified by candidate gene, family-based, and exome studies have also been reported to associate with IPF. However, the extent to which rare variants, genome-wide, may contribute to the risk of IPF remains unknown. Objectives: We used whole-genome sequencing to investigate the role of rare variants, genome-wide, on IPF risk. Methods: As part of the Trans-Omics for Precision Medicine Program, we sequenced 2,180 cases of IPF. Association testing focused on the aggregated effect of rare variants (minor allele frequency ⩽0.01) within genes or regions. We also identified individual rare variants that are influential within genes and estimated the heritability of IPF on the basis of rare and common variants. Measurements and Main Results: Rare variants in both TERT and RTEL1 were significantly associated with IPF. A single rare variant in each of the TERT and RTEL1 genes was found to consistently influence the aggregated test statistics. There was no significant evidence of association with other previously reported rare variants. The SNP heritability of IPF was estimated to be 32% (SE = 3%). Conclusions: Rare variants within the TERT and RTEL1 genes and well-established common variants have the largest contribution to IPF risk overall. Efforts in risk profiling or the development of therapies for IPF that focus on TERT, RTEL1, common variants, and environmental risk factors are likely to have the largest impact on this complex disease.

Improved targeting delivery of WED-load immunoliposomes modified with SP-A mAb for the treatment of pulmonary fibrosis

The epithelial-mesenchymal transition (EMT) of type Ⅱ alveolar epithelial cells (AECS Ⅱ) induced by transforming growth factor (TGF-β1) is a primary pathogenesis of pulmonary fibrosis (PF). To augment the therapeutic potency of wedelolactone (WED) for PF, herein, pulmonary surfactant protein A (SP-A) specifically expressed on AECS Ⅱ was selected as the targeted receptor. Immunoliposomes modified with SP-A monoclonal antibody (SP-A mAb), novel anti-PF drug delivery systems, were developed and investigated in vivo and in vitro. In vivo fluorescence imaging technique was performed to evaluate the pulmonary-targeting effects of immunoliposomes. The result showed that immunoliposomes accumulated more in the lung, compared with non-modified nanoliposomes. Fluorescence detection methods and flow cytometry were used to investigate the function of SP-A mAb and the cellular uptake efficiency of WED-ILP in vitro. SP-A mAb enabled the immunoliposomes to specifically target the A549 cells and increased uptake more effectively. The mean fluorescence intensity (MFI) of cells treated with the targeted immunoliposomes was about 1.4-fold higher than that of cells treated with regular nanoliposomes. The cytotoxicity of nanoliposomes was assessed by the MTT assay, which demonstrated that blank nanoliposomes have no significant effect on A549 cell proliferation even at the SPC concentration of 1000 µg/mL. Additionally, in vitro pulmonary fibrosis model was established to further investigate the anti-pulmonary fibrosis effect of WED-ILP. WED-ILP significantly (**P < 0.01) inhibited the proliferation of A549 cells stimulated by TGF-β1 indicating that WED-ILP has great potential for the clinical treatment of PF.

Cellular Distribution of Secreted Phospholipase A2 in Lungs of IPF Patients and Its Inhibition in Bleomycin-Induced Pulmonary Fibrosis in Mice

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease with a very poor prognosis as it has a 2.5 to 5 years mean survival after proper diagnosis. Even nintedanib and pirfenidone cannot halt the progression, though they slow the progression of IPF. Hence, there is a need to understand the novel pathophysiology. Phospholipase A2 (PLA2) could be the ideal candidate to study in IPF, as they have a role in both inflammation and fibrosis. In the present study, we have shown the expression profile of various secretory Phospholipase A2 (PLA2) isoforms by analyzing publicly available transcriptome data of single cells from the lungs of healthy individuals and IPF patients. Among 11 members of sPLA2, PLA2G2A is found to be increased in the fibroblasts and mesothelial cells while PLA2G5 is found to be increased in the fibroblasts of IPF patients. We identified a subset of fibroblasts expressing high PLA2G2A with moderate expression of PLA2G5 and which are specific to IPF only; we named it as PLA2G2A+ IPF fibroblast. Pathway analysis revealed that these PLA2G2A+ IPF fibroblast have upregulation of both inflammatory and fibrosis-related pathways like the TGF-β signaling pathway, IL-17 signaling, the arachidonic acid metabolism pathway and ECM-receptor interaction. In addition to this, we found elevated levels of sPLA2-IIA in plasma samples of IPF patients in our cohort. PLA2G3, PLA2G10 and PLA2G12B are found in to be increased in certain epithelial cells of IPF patients. Thus, these findings indicate that these five isoforms have a disease-dominant role along with innate immune roles as these isoforms are found predominantly in structural cells of IPF patients. Further, we have targeted sPLA2 in mice model of bleomycin-induced lung fibrosis by pBPB, a known sPLA2 inhibitor. pBPB treatment attenuated lung fibrosis induced by bleomycin along with a reduction in TGF-β and deposition of extracellular matrix in lung. Thus, these findings indicate that these sPLA2 isoforms especially PLA2G2A may serve as a therapeutic target in lung fibrosis.

Loss of IGFBP2 mediates alveolar type 2 cell senescence and promotes lung fibrosis

Accumulation of senescent cells contributes to age-related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) regulate many biological processes; however, the functional contributions of IGFBP2 in lung fibrosis remain largely unclear. Here, we report that intranasal delivery of recombinant IGFBP2 protects aged mice from weight loss and demonstrated antifibrotic effects after bleomycin lung injury. Notably, aged human-Igfbp2 transgenic mice reveal reduced senescence and senescent-associated secretory phenotype factors in alveolar epithelial type 2 (AEC2) cells and they ameliorated bleomycin-induced lung fibrosis. Finally, we demonstrate that IGFBP2 expression is significantly suppressed in AEC2 cells isolated from fibrotic lung regions of patients with IPF and/or pulmonary hypertension compared with patients with hypersensitivity pneumonitis and/or chronic obstructive pulmonary disease. Altogether, our study provides insights into how IGFBP2 regulates AEC2-cell-specific senescence and that restoring IGFBP2 levels in fibrotic lungs can prove effective for patients with IPF.

Idiopathic pulmonary fibrosis and the role of genetics in the era of precision medicine

Idiopathic pulmonary fibrosis (IPF) is a chronic, rare progressive lung disease, characterized by lung scarring and the irreversible loss of lung function. Two anti-fibrotic drugs, nintedanib and pirfenidone, have been demonstrated to slow down disease progression, although IPF mortality remains a challenge and the patients die after a few years from diagnosis. Rare pathogenic variants in genes that are involved in the surfactant metabolism and telomere maintenance, among others, have a high penetrance and tend to co-segregate with the disease in families. Common recurrent variants in the population with modest effect sizes have been also associated with the disease risk and progression. Genome-wide association studies (GWAS) support at least 23 genetic risk loci, linking the disease pathogenesis with unexpected molecular pathways including cellular adhesion and signaling, wound healing, barrier function, airway clearance, and innate immunity and host defense, besides the surfactant metabolism and telomere biology. As the cost of high-throughput genomic technologies continuously decreases and new technologies and approaches arise, their widespread use by clinicians and researchers is efficiently contributing to a better understanding of the pathogenesis of progressive pulmonary fibrosis. Here we provide an overview of the genetic factors known to be involved in IPF pathogenesis and discuss how they will continue to further advance in this field. We also discuss how genomic technologies could help to further improve IPF diagnosis and prognosis as well as for assessing genetic risk in unaffected relatives. The development and validation of evidence-based guidelines for genetic-based screening of IPF will allow redefining and classifying this disease relying on molecular characteristics and contribute to the implementation of precision medicine approaches.

The Vasculature in Pulmonary Fibrosis

Purpose of Review

The current paradigm of idiopathic pulmonary fibrosis (IPF) pathogenesis involves recurrent injury to a sensitive alveolar epithelium followed by impaired repair responses marked by fibroblast activation and deposition of extracellular matrix. Multiple cell types are involved in this response with potential roles suggested by advances in single-cell RNA sequencing and lung developmental biology. Notably, recent work has better characterized the cell types present in the pulmonary endothelium and identified vascular changes in patients with IPF.

Recent Findings

Lung tissue from patients with IPF has been examined at single-cell resolution, revealing reductions in lung capillary cells and expansion of a population of vascular cells expressing markers associated with bronchial endothelium. In addition, pre-clinical models have demonstrated a fundamental role for aging and vascular permeability in the development of pulmonary fibrosis.

Summary

Mounting evidence suggests that the endothelium undergoes changes in the context of fibrosis, and these changes may contribute to the development and/or progression of pulmonary fibrosis. Additional studies will be needed to further define the functional role of these vascular changes.

The Efficacy and Safety of Herbal Medicine with Pirfenidone in the Treatment of Idiopathic Pulmonary Fibrosis: A Systematic Review

Although there were randomized control trials (RCTs) that showed the considerable efficacy of herbal medicine (HM) in idiopathic pulmonary fibrosis (IPF) and systematic reviews on the value of some herbs in the treatment of IPF, there have been no systematic reviews comparing the combined use of complex HM against pirfenidone monotherapy in IPF. This review evaluated the efficacy of parallel administration of HM and pirfenidone in IPF treatment. We conducted a systematic review of RCTs that compared pirfenidone monotherapy against pirfenidone combined administration with HM in IPF. We searched the EMBASE, CENTRAL, PubMed, and CNKI databases for relevant RCTs published before July 2021. Six RCTs were eligible for inclusion. Compared with the control group, a greater recovery or a smaller reduction in forced vital capacity (FVC) and, in general, a valid improvement in the St. George’s Respiratory Questionnaire was observed in the treatment group. However, it should be noted that the risk of bias of the included RCTs was high or unclear in most categories. In IPF treatment, HM administered with pirfenidone effectively protected pulmonary function and improved the quality of life. However, given the number and quality of the included studies, the evidence was not strong enough to draw definitive conclusions. Well-designed future RCTs are warranted to evaluate the impact of HM on IPF.

The impact of FVC/DLCO ratio on diagnosis of pulmonary hypertension and disease prognosis in idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis is a chronic progressive fibrotic lung disease of unknown etiology that occurs most commonly in older adults. The presence of pulmonary hypertension in Idiopathic pulmonary fibrosis is associated with poor prognosis and mortality. Literature suggests that the forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio has a positive predictive value for the diagnosis of pulmonary hypertension. Therefore, this study aimed to investigate the impact of forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio on the diagnosis of pulmonary hypertension and disease prognosis in Idiopathic pulmonary fibrosis patients. MATERIAL AND METHOD: Forty-eight patients diagnosed with Idiopathic pulmonary fibrosis were included in the study. Patient records, echocardiographic and spirometric data were retrospectively reviewed. Results: The average pulmonary arterial pressure was observed to be 32.8 (±9) mmHg, with the second-year follow-up pulmonary arterial pressure at 40.8 (±17.2) mmHg and the fourth-year follow-up pulmonary arterial pressure at 51 (±23.6) mmHg. In those diagnosed as pulmonary hypertension, the forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio was initially 1.54 (±0.72). By the second year, it was 1.61 (±0.45), and by the fourth year, it was 1.87 (±0.8). It was found that the forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio tended to increase when pulmonary artery pressure increased during the follow-up period. Conclusion: We found that low six- minute walking test distance was an important marker for the diagnosis of pulmonary hypertension in patients with idiopathic pulmonary fibrosis and that the presence of desaturation was also significantly associated with survival in pulmonary hypertension. Although we did not find it statistically significant, we found that both pulmonary arterial pressure and the the forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio increased with progressive disease duration after diagnosis in patients with IPF. We believe that the the forced vital capacity to diffusion capacity of the lung for carbon monoxide ratio is an important marker for early detection of pulmonary hypertension and prognosis in idiopathic pulmonary fibrosis.

Dynamic contrast enhanced MRI for the evaluation of lung perfusion in idiopathic pulmonary fibrosis

BACKGROUND

The objective of this work was to apply quantitative and semiquantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) methods to evaluate lung perfusion in idiopathic pulmonary fibrosis (IPF).

METHODS

In this prospective trial 41 subjects, including healthy control and IPF subjects, were studied using DCE-MRI at baseline. IPF subjects were then followed for 1 year; progressive IPF (IPFprog) subjects were distinguished from stable IPF (IPFstable) subjects based on a decline in percent predicted forced vital capacity (FVC % pred) or diffusing capacity of the lung for carbon monoxide (D LCO % pred) measured during follow-up visits. 35 out of 41 subjects were retained for final baseline analysis (control: n=15; IPFstable: n=14; IPFprog: n=6). Seven measures and their coefficients of variation (CV) were derived using temporally resolved DCE-MRI. Two sets of global and regional comparisons were made: control versus IPF groups and control versus IPFstable versus IPFprog groups, using linear regression analysis. Each measure was compared with FVC % pred, D LCO % pred and the lung clearance index (LCI % pred) using a Spearman rank correlation.

RESULTS

DCE-MRI identified regional perfusion differences between control and IPF subjects using first moment transit time (FMTT), contrast uptake slope and pulmonary blood flow (PBF) (p≤0.05), while global averages did not. FMTT was shorter for IPFprog compared with both IPFstable (p=0.004) and control groups (p=0.023). Correlations were observed between PBF CV and D LCO % pred (rs= -0.48, p=0.022) and LCI % pred (rs= +0.47, p=0.015). Significant group differences were detected in age (p<0.001), D LCO % pred (p<0.001), FVC % pred (p=0.001) and LCI % pred (p=0.007).

CONCLUSIONS

Global analysis obscures regional changes in pulmonary haemodynamics in IPF using DCE-MRI in IPF. Decreased FMTT may be a candidate marker for IPF progression.

Ethnographic survey of patients and caregiver's life journey in idiopathic pulmonary fibrosis

OBJECTIVES

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease associated with high mortality. The IPF journey affects patients' and caregivers' quality of life, this should be taken into account as an important parameter for a better disease management. An ethnographic study was conducted between December 2019 and January 2020 to explore social disease representations, patients' and cargivers' experiences in the disease journey and consequences in their daily life, to identify the means of actions permitting a quality of life (QoL) improvement.

PATIENTS/CAREGIVERS

Twenty respondents, twelve patients aged 43 to 84 years old and eight caregivers in four French regions were met. Eleven patients were diagnosed with IPF between 2013 and 2017 and one patient in 1988 (at 12 years old). The lung function reported by patients ranged as follows: forced vital capacity from 112% to 40% and diffusing capacity of the lungs for carbon monoxide (DLCO) from 66% to <20%.

RESULTS

The survey included patients diagnosed at least three years ago. Collected data comprised disease representation, patients'/caregivers' experience of the disease, healthcare journey, and consequences for their daily life. The first signs identified by the patient or their caregiver may not have been taken seriously by the primary care physician. The pre-diagnosis period was considered particularly traumatic for most patients. The biopsy performed in 8 cases was experienced as violent by 4/8 patients, some of whom still feel pain. Patients/caregivers knew how to define their disease and spontaneously gave severe representations of the disease such as "Rare, incurable disease", "an organ being destroyed".

DISCUSSION

This study highlighted patients'/caregivers' common needs at each stage of the disease. The lack of disease knowledge from frontline practitioners (general physicians, community pulmonologists) can lead to significant diagnostic error. Patients require psychological support and more information on daily aspects in disease management, such as food good practices and importance of physical activity, along with information about disease progression. The fear caused by these shortages can be reduced through contact with patients' associations.

CONCLUSIONS

Numerous essential data were identified and should be considered for supporting actions that could allow to improve the QoL of patients with IPF.

Mesenchyme Stem Cell-Derived Conditioned Medium as a Potential Therapeutic Tool in Idiopathic Pulmonary Fibrosis

Mesenchyme Stem Cells (MSCs) are the most used types of stem cells in regenerative medicine. Regenerative medicine is a rapidly emerging medicine section that creates new methods to regrow, restore, and replace diseased and damaged tissues, organs, and cells. Scholars have shown a positive correlation between MSCs-based therapies and successful treatment of diseases like cardiac ischemia, cartilage problems, bone diseases, diabetes, and even neurological disorders. Although MSCs have several varying features that make them unique, their immuno-regulatory effects in tissue repair emerge from their secretion of paracrine growth factors, exosomes, and cytokines. These cells secrete a secretome, which has regenerative and reparative properties that lead to injury amelioration, immune modulation, or fibrosis reduction. Recent studies have shown that the administration MCSs derived conditioned medium (MSCs-CM) in acute doses in humans is safe and well-tolerated. Studies from animal models and human clinical trials have also shown that they are efficacious tools in regenerative medicine. In this review, we will explore the therapeutic potential of MSCs-CM in pulmonary fibrosis, with further insight into the treatment of Idiopathic Pulmonary Fibrosis (IPF).

B7H3-dependent myeloid-derived suppressor cell recruitment and activation in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease without effective curative therapy. Recent evidence shows increased circulating myeloid-derived suppressor cells (MDSCs) in cancer, inflammation, and fibrosis, with some of these cells expressing B7H3. We sought to investigate the role of MDSCs in IPF and its potential mediation via B7H3. Here we prospectively collected peripheral blood samples from IPF patients to analyze for circulating MDSCs and B7H3 expression to assess their clinical significance and potential impact on co-cultured lung fibroblasts and T-cell activation. In parallel, we assess MDSC recruitment and potential B7H3 dependence in a mouse model of pulmonary fibrosis. Expansion of MDSCs in IPF patients correlated with disease severity. Co-culture of soluble B7H3 (sB7H3)-treated mouse monocytic MDSCs (M-MDSCs), but not granulocytic MDSCs (G-MDSCs), activated lung fibroblasts and myofibroblast differentiation. Additionally, sB7H3 significantly enhanced MDSC suppression of T-cell proliferation. Activated M-MDSCs displayed elevated TGFβ and Arg1 expression relative to that in G-MDSCs. Treatment with anti-B7H3 antibodies inhibited bone marrow-derived MDSC recruitment into the bleomycin-injured lung, accompanied by reduced expression of inflammation and fibrosis markers. Selective telomerase reverse transcriptase (TERT) deficiency in myeloid cells also diminished MDSC recruitment associated with the reduced plasma level of sB7H3, lung recruitment of c-Kit⁺ hematopoietic progenitors, myofibroblast differentiation, and fibrosis. Lung single-cell RNA sequencing (scRNA-seq) revealed fibroblasts as a predominant potential source of sB7H3, and indeed the conditioned medium from activated mouse lung fibroblasts had a chemotactic effect on bone marrow (BM)-MDSC, which was abolished by B7H3 blocking antibody. Thus, in addition to their immunosuppressive activity, TERT and B7H3-dependent MDSC expansion/recruitment from BM could play a paracrine role to activate myofibroblast differentiation during pulmonary fibrosis with potential significance for disease progression mediated by sB7H3.

Bryodulcosigenin attenuates bleomycin-induced pulmonary fibrosis via inhibiting AMPK-mediated mesenchymal epithelial transition and oxidative stress

Fibrosis is a pathological result of a dysfunctional repair response to tissue injury and occurs in several organs, including the lungs. Bryodulcosigenin (BDG) is a cucurbitane-type triterpene isolated from Siratia grosvenori and has clear-cut anti-inflammatory effects, yet its benefit of pulmonary fibrosis (PF) remains unclear. In this study, we investigated the protective effects of BDG (10 mg/kg/day, for 14 days) against TGF-β1-stimulated mouse alveolar epithelial MLE-12 cells and bleomycin (BLM)-induced PF mice. In vitro experiments showed that BDG could inhibit epithelial-mesenchymal transition (EMT) and oxidative stress. In vivo experiments indicated that BDG could ameliorate BLM-induced PF in mice as evidenced by characteristic structural changes in histopathology, increased collagen deposition and reduced survival and weight of mice. The abnormal increased expressions of TGF-β1, p-Smad2/3, α-SMA, COL-I, and NOX4 and decreased expressions for Sirt1 and p-AMPK were improved in BDG treatment. But these beneficial effects could be eliminated by co-treatment with Compound C (CC, a selective AMPK inhibitor). Molecular docking technology also revealed the potential of BDG to activate AMPK. In summary, AMPK activation modulated by BDG not only ameliorated TGF-β1/Smad2/3 signaling pathways but also partially mediated the suppression effects on EMT and oxidative stress, thus mediating the anti-fibrotic effects.

Targeting Growth Factor and Cytokine Pathways to Treat Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown origin that usually results in death from secondary respiratory failure within 2–5 years of diagnosis. Recent studies have identified key roles of cytokine and growth factor pathways in the pathogenesis of IPF. Although there have been numerous clinical trials of drugs investigating their efficacy in the treatment of IPF, only Pirfenidone and Nintedanib have been approved by the FDA. However, they have some major limitations, such as insufficient efficacy, undesired side effects and poor pharmacokinetic properties. To give more insights into the discovery of potential targets for the treatment of IPF, this review provides an overview of cytokines, growth factors and their signaling pathways in IPF, which have important implications for fully exploiting the therapeutic potential of targeting cytokine and growth factor pathways. Advances in the field of cytokine and growth factor pathways will help slow disease progression, prolong life, and improve the quality of life for IPF patients in the future.

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.

PI3K Signaling in Mechanisms and Treatments of Pulmonary Fibrosis Following Sepsis and Acute Lung Injury

Pulmonary fibrosis is a pathological fibrotic process affecting the lungs of five million people worldwide. The incidence rate will increase even more in the next years due to the long-COVID-19 syndrome, but a resolving treatment is not available yet and usually prognosis is poor. The emerging role of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling in fibrotic processes has inspired the testing of drugs targeting the PI3K/Akt pathway that are currently under clinical evaluation. This review highlights the progress in understanding the role of PI3K/Akt in the development of lung fibrosis and its causative pathological context, including sepsis as well as acute lung injury (ALI) and its consequent acute respiratory distress syndrome (ARDS). We further summarize current knowledge about PI3K inhibitors for pulmonary fibrosis treatment, including drugs under development as well as in clinical trials. We finally discuss how the design of inhaled compounds targeting the PI3K pathways might potentiate efficacy and improve tolerability.

Transient Agarose Spot (TAS) Assay: A New Method to Investigate Cell Migration

Fibroblasts play a central role in diseases associated with excessive deposition of extracellular matrix (ECM), including idiopathic pulmonary fibrosis. Investigation of different properties of fibroblasts, such as migration, proliferation, and collagen-rich ECM production is unavoidable both in basic research and in the development of antifibrotic drugs. In the present study we developed a cost-effective, 96-well plate-based method to examine the migration of fibroblasts, as an alternative approach to the gold standard scratch assay, which has numerous limitations. This article presents a detailed description of our transient agarose spot (TAS) assay, with instructions for its routine application. Advantages of combined use of different functional assays for fibroblast activation in drug development are also discussed by examining the effect of nintedanib—an FDA approved drug against IPF—on lung fibroblasts.

Percepción de los pacientes en cuanto al manejo de la fibrosis pulmonar idiopática. Proyecto Explora-IPF

Introduction

Idiopathic pulmonary fibrosis (IPF) impacts the life of patients and their families, so it is necessary to ascertain their perception in the approach to their disease.

Methods

Observational study by means of a specific questionnaire that includes socio-demographic and clinical variables, perception of the impact of the disease (5-point Likert scale), preferences regarding the characteristics of the medication (degree of importance/concern 1-10) and satisfaction with treatment (SATMED-Q® scale 0-100).

Results

69 individuals participated (age: 66.5 ± 7.6 years; time until diagnosis: 16.5 ± 17.4 months; diagnosis time: 49.6 ± 42.3 months). The majority state that IPF limits them physically (90%) and emotionally (75%). The most highly valued features of the treatment were: slowing down progression of the disease (7.4 ± 2.8), stabilising lung capacity (6.9 ± 2.8) and improving quality of life (6.9 ± 2.8), above stabilising/improving symptoms (6.1 ± 2.8/6.3 ± 2.8) or avoiding hospitalisation (6.6 ± 2.7). The principal factors of concern were suffering gastric disorders (7.1 ± 2.9), photosensitivity (6.6 ± 3.0) or interaction with other drugs (6.0 ± 3.0). Overall satisfaction with the current treatment scored 61.1 points, with the highest scores being for medical follow-up (79.5) and overall opinion of the medicine (74.3).

Conclusions

A study conducted in Spain on the perspective of IPF patients regarding the disease and its treatment. The results show a high level of awareness in terms of the seriousness of the disease on the part of patients, whose main concern is to slow down its progression. The information provided may help to optimise the management of IPF patients.

Targeting PI3K/AKT signaling for treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic interstitial pneumonia with unknown causes. The incidence rate increases year by year and the prognosis is poor without cure. Recently, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) signaling pathway can be considered as a master regulator for IPF. The contribution of the PI3K/AKT in fibrotic processes is increasingly prominent, with PI3K/AKT inhibitors currently under clinical evaluation in IPF. Therefore, PI3K/AKT represents a critical signaling node during fibrogenesis with potential implications for the development of novel anti-fibrotic strategies. This review epitomizes the progress that is being made in understanding the complex interpretation of the cause of IPF, and demonstrates that PI3K/AKT can directly participate to the greatest extent in the formation of IPF or cooperate with other pathways to promote the development of fibrosis. We further summarize promising PI3K/AKT inhibitors with IPF treatment benefits, including inhibitors in clinical trials and pre-clinical studies and natural products, and discuss how these inhibitors mitigate fibrotic progression to explore possible potential agents, which will help to develop effective treatment strategies for IPF in the near future.

Structure dependence and species sensitivity of in vivo hepatobiliary toxicity with lysophosphatidic acid receptor 1 (LPA1) antagonists

BMS-986020, BMS-986234 and BMS-986278, are three lysophosphatidic acid receptor 1 (LPA₁) antagonists that were or are being investigated for treatment of idiopathic pulmonary fibrosis (IPF). Hepatobiliary toxicity (elevated serum AST, ALT, and ALP, plasma bile acids [BAs], and cholecystitis) was observed in a Phase 2 clinical trial with BMS-986020, and development was discontinued. In dogs and rats, the species used for the pivotal toxicology studies, there was no evidence of hepatobiliary toxicity in the dog while findings in the rat were limited to increased plasma BAs levels (6.1× control), ALT (2.9×) and bilirubin (3.4×) with no histopathologic correlates. Since neither rats nor dogs predicted clinical toxicity, follow-up studies in cynomolgus monkeys revealed hepatobiliary toxicity that included increased ALT (2.0× control) and GLDH (4.9×), bile duct hyperplasia, cholangitis, cholestasis, and cholecystitis at clinically relevant BMS-986020 exposures with no changes in plasma or liver BAs. This confirmed monkey as a relevant species for identifying hepatobiliary toxicity with BMS-986020. In order to assess whether the toxicity was compound-specific or related to LPA₁ antagonism, two structurally distinct LPA₁ antagonists (BMS-986234 and BMS-986278), were evaluated in rat and monkey. There were no clinical or anatomic pathology changes indicative of hepatobiliary toxicity. Mixed effects on plasma bile acids in both rat and monkey has made this biomarker not a useful predictor of the hepatobiliary toxicity. In conclusion, the nonclinical data indicate the hepatobiliary toxicity observed clinically and in monkeys administered BMS-986020 is compound specific and not mediated via antagonism of LPA₁.

Evaluation of efficacy and safety of pirfenidone 200 mg tablets in patients with idiopathic pulmonary fibrosis in a real-life setting

Background/aim

Phase III trials have demonstrated a significant efficacy and an acceptable safety for pirfenidone in patients having mild to moderate idiopathic pulmonary fibrosis (IPF). Real-life data on the use of pirfenidone 200 mg tablets are limited. This study aimed to investigate the efficacy and safety of pirfenidone 200 mg tablets for the treatment of IPF in a real-life setting.

Materials and methods

A retrospective, multicenter study conducted in four university hospitals in Turkey between January 2017 and January 2019. Clinical records of patients diagnosed with mild to moderate IPF and receiving pirfenidone (200 mg tablets, total 2400 mg/day) were reviewed retrospectively and consecutively. Pulmonary function measurements including forced vital capacity (FVC%) and diffusing capacity of the lungs for carbon monoxide (DLCO%) were analyzed at baseline and after 6-month of pirfenidone treatment. Descriptive statistics were expressed as mean, standard error or median (minimum-maximum), number and percentage, where appropriate.

Results

The study included 82 patients, of whom 87.8% were males (mean age, 66 years). After 6-month of treatment, 7 patients discontinued the treatment. Of the remaining 75 patients, 71 (94.6%) remained stable, 4 (5.4%) had progressive disease as evident by a decline in the FVC% of at least 10% while on treatment, and 45 (61.3%) had improved cough. At least one adverse event (AE) associated with the treatment was observed in 28 (37.3%) patients.

Conclusion

Pirfenidone 200 mg was effective and well tolerated and associated with relatively mild and manageable AEs in IPF patien

The Role of Hippo/YAP Signaling in Alveolar Repair and Pulmonary Fibrosis

Pulmonary fibrosis is characterized by loss of normal alveoli, accumulation of pathologic activated fibroblasts, and exuberant extracellular matrix deposition that over time can lead to progressive loss of respiratory function and death. This loss of respiratory function is associated with the loss of alveolar type 1 cells (AT1) that play a crucial role in gas exchange and the depletion of the alveolar type 2 cells (AT2) that act as progenitor cells to regenerate the AT1 and AT2 cell populations during repair. Understanding the mechanisms that regulate normal alveolar repair and those associated with pathologic repair is essential to identify potential therapeutic targets to treat or delay progression of fibrotic diseases. The Hippo/YAP developmental signaling pathway has been implicated as a regulator of normal alveolar development and repair. In idiopathic pulmonary fibrosis, aberrant activation of YAP/TAZ has been demonstrated in both the alveolar epithelium and activated fibroblasts associated with increased fibrotic remodeling, and there is emerging interest in this pathway as a target for antifibrotic therapies. In this review, we summarize current evidence as to the role of the Hippo-YAP/TAZ pathway in alveolar development, homeostasis, and repair, and highlight key questions that must be resolved to determine effective strategies to modulate YAP/TAZ signaling to prevent progressive pulmonary fibrosis and enhance adaptive alveolar repair.

Idiopathic Pulmonary Comorbidities and Mechanisms

Idiopathic pulmonary fibrosis (IPF) is a disease with an unknown etiology mainly characterized by a progressive decline of lung function due to the scarring of the tissue deep in the lungs. The overall survival after diagnosis remains low between 3 and 5 years. IPF is a heterogeneous disease and much progress has been made in the past decade in understanding the disease mechanisms that contributed to the development of two new drugs, pirfenidone and nintedanib, which improved the therapeutic management of the disease. The understanding of the cofactors and comorbidities of IPF also contributed to improved management of the disease outcome. In the present review, we evaluate scientific evidence which indicates IPF as a risk factor for other diseases based on the complexity of molecular and cellular mechanisms involved in the disease development and of comorbidities. We conclude from the existing literature that while much progress has been made in understating the mechanisms involved in IPF development, further studies are still necessary to fully understand IPF pathogenesis which will contribute to the identification of novel therapeutic targets for IPF management as well as other diseases for which IPF is a major risk factor.

Design of phase 2 study of TAS-115, a novel oral multi-kinase inhibitor, in patients with idiopathic pulmonary fibrosis

Background

TAS-115, a novel multi-kinase inhibitor, demonstrated antifibrotic effects in vitro and in vivo.

Methods

This is an open-label, intra-patient comparison, exploratory phase 2 study of TAS-115 to evaluate the efficacy and safety in idiopathic pulmonary fibrosis (IPF) patients when orally administered at 200 mg once daily on a 5-day on and 2-day off regimen for 13 weeks. This study consists of three cohorts: previously treated with pirfenidone (Cohort P, n = 20), with nintedanib (Cohort N, n = 20), and treatment naïve (Cohort U, n = 10). Male or female patients aged ≥40 to <80 years who were diagnosed with IPF in the preceding five years and having a percent predicted forced vital capacity (%FVC) decline of ≥5% within the previous 6 months were enrolled in this study. The primary endpoint is change in the slope of %FVC decline at Week 13 from baseline. Key secondary endpoints are safety, change in FVC from baseline, proportion of the %FVC responders and change in percent predicted diffusing capacity of the lung carbon monoxide from baseline, which are assessed at Weeks 6, 13 and 26.

Results

Enrollment of 45 patients was completed in July 2019. Results will be reported in 2021.

Discussion

This trial is intended to demonstrate the clinical efficacy of TAS-115 in IPF patients who have not responded to pirfenidone or nintedanib, as well as in those who are pirfenidone/nintedanib treatment naïve. The safety and tolerability in this population will be assessed.

Trial registration

JapicCTI-183898.

Bidirectional epithelial-mesenchymal crosstalk provides self-sustaining profibrotic signals in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2 to 4 years. Injury to and/or dysfunction of the alveolar epithelium is strongly implicated in IPF disease initiation, but the factors that determine whether fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that zinc finger E-box-binding homeobox 1-mediated epithelial-mesenchymal transition in human alveolar epithelial type II (ATII) cells augments transforming growth factor-β-induced profibrogenic responses in underlying lung fibroblasts via paracrine signaling. Here, we investigated bidirectional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA-Seq of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced epithelial-mesenchymal transition identified many differentially expressed genes including those involved in cell migration and extracellular matrix regulation. We confirmed that paracrine signaling between RAS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a zinc finger E-box-binding homeobox 1-tissue plasminogen activator axis. In a reciprocal fashion, paracrine signaling from transforming growth factor-β-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially through the secreted protein acidic and rich in cysteine, which may signal via the epithelial growth factor receptor via epithelial growth factor-like repeats. Together, these data identify that aberrant bidirectional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining profibrotic signals.

Contraindications to the Initiation of Veno-Venous ECMO for Severe Acute Respiratory Failure in Adults: A Systematic Review and Practical Approach Based on the Current Literature

(1) Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used for acute respiratory failure with few absolute but many relative contraindications. The provider in charge often has a difficult time weighing indications and contraindications to anticipate if the patient will benefit from this treatment, a decision that often decides life and death for the patient. To assist in this process in coming to a good evidence-based decision, we reviewed the available literature. (2) Methods: We performed a systematic review through a literature search of the MEDLINE database of former and current absolute and relative contraindications to the initiation of ECMO treatment. (3) Results: The following relative and absolute contraindications were identified in the literature: absolute-refusal of the use of extracorporeal techniques by the patient, advanced stage of cancer, fatal intracerebral hemorrhage/cerebral herniation/intractable intracranial hypertension, irreversible destruction of the lung parenchyma without the possibility of transplantation, and contraindications to lung transplantation; relative-advanced age, immunosuppressed patients/pharmacological immunosuppression, injurious ventilator settings > 7 days, right-heart failure, hematologic malignancies, especially bone marrow transplantation and graft-versus-host disease, SAPS II score ≥ 60 points, SOFA score > 12 points, PRESERVE score ≥ 5 points, RESP score ≤ -2 points, PRESET score ≥ 6 points, and "do not attempt resuscitation" order (DN(A)R status). (4) Conclusions: We provide a simple-to-follow algorithm that incorporates absolute and relative contraindications to the initiation of ECMO treatment. This algorithm attempts to weigh pros and cons regarding the benefit for an individual patient and hopefully assists caregivers to make better, informed decisions.

The effect of heated humidified nasal high flow oxygen supply on exercise tolerance in patients with interstitial lung disease: A pilot study

BACKGROUND AND OBJECTIVES

Patients with interstitial lung disease (ILD) experience early symptoms of dyspnoea and leg fatigue during exercise together with severe and rapid oxygen desaturation. Heated and humidified nasal high flow oxygen (NHF) has been proven to enhance exercise endurance and physiological parameters in COPD patients. This study aims to evaluate the effect of NHF on exercise tolerance in ILD patients.

METHODS

Twenty-five patients (10 female) with severe ILD performed three constant-load (70% maximal workload) cycling tests to exhaustion under different breathing conditions: room air, oxygen supplementation (4 L min^-1 O₂) and NHF (inspiratory O₂ fraction 0.5, 30-50 L min^-1, heated 34 °C and humidified).

RESULTS

Endurance time was significantly longer with NHF (618 ± 297 s) compared to O₂ (369 ± 217 s, p < 0.001) and room air (171 ± 76 s, p < 0.001). Kinetics of oxygen desaturation, chronotropic response, dyspnoea and leg fatigue sensations were delayed with NHF. At exhaustion with NHF, compared to the two other conditions, oxygen desaturation was less severe while heart rate, dyspnoea and leg fatigue were similar.

CONCLUSION

NHF significantly improved endurance time, physiological parameters and sensations during exercise in severe ILD patients. NHF may be useful to improve functional capacities and facilitate pulmonary rehabilitation in ILD.

Hyperbaric Oxygen Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Mice

The prevalence of pulmonary fibrosis is increasing with an aging population and its burden is likely to increase following COVID-19, with large financial and medical implications. As approved therapies in pulmonary fibrosis only slow disease progression, there is a significant unmet medical need. Hyperbaric oxygen (HBO) is the inhaling of pure oxygen, under the pressure of greater than one atmosphere absolute, and it has been reported to improve pulmonary function in patients with pulmonary fibrosis. Our recent study suggested that repetitive HBO exposure may affect biological processes in mice lungs such as response to wounding and extracellular matrix. To extend these findings, a bleomycin-induced pulmonary fibrosis mouse model was used to evaluate the effect of repetitive HBO exposure on pulmonary fibrosis. Building on our previous findings, we provide evidence that HBO exposure attenuates bleomycin-induced pulmonary fibrosis in mice. In vitro, HBO exposure could reverse, at least partially, transforming growth factor (TGF)-β-induced fibroblast activation, and this effect may be mediated by downregulating TGF-β-induced expression of hypoxia inducible factor (HIF)-1α. These findings support HBO as a potentially life-changing therapy for patients with pulmonary fibrosis, although further research is needed to fully evaluate this.