Pirfenidone treatment of idiopathic pulmonary fibrosis

Modeling Molecular Mechanisms of Pirfenidone Interaction with Kinases

Scar formation is a process that occurs due to increased collagen deposition and uncontrolled inflammation. Previous studies have demonstrated that Pirfenidone (Pf), an FDA approved anti-inflammatory and antifibrotic drug can reduce inflammation in vivo as well as regulate activation of LPS-stimulated neutrophils. However, the molecular level mechanism of Pf's action is not well understood. Here, we used neural networks to identify new targets and molecular modeling methods to investigate the Pf's action pathways at the molecular level that are related to its ability to reduce both the inflammatory and remodeling phases of the wound healing process. Out of all the potential targets identified, both molecular docking and molecular dynamics results suggest that Pf has a noteworthy binding preference towards the active conformation of the p38 mitogen activated protein kinase-14 (MAPK14) and it is potentially a type I inhibitor-like molecule. In addition to p38 MAPK (MAPK14), additional potential targets of Pf include AKT1, MAP3K4, MAP2K3, MAP2K6, MSK2, MAP2K2, ERK1, ERK2, and PDK1. We conclude that several proteins/kinases, rather than a single target, are involved in Pf's wound healing ability to regulate signaling, inflammation, and proliferation.

Different Levels of Autophagy Activity in Mesenchymal Stem Cells Are Involved in the Progression of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is an age-related lung interstitial disease that occurs predominantly in people over 65 years of age and for which there is a lack of effective therapeutic agents. It has demonstrated that mesenchymal stem cells (MSCs) including alveolar epithelial cells (AECs) can perform repair functions. However, MSCs lose their repair functions due to their distinctive aging characteristics, eventually leading to the progression of IPF. Recent breakthroughs have revealed that the degree of autophagic activity influences the renewal and aging of MSCs and determines the prognosis of IPF. Autophagy is a lysosome-dependent pathway that mediates the degradation and recycling of intracellular material and is an efficient way to renew the nonnuclear (cytoplasmic) part of eukaryotic cells, which is essential for maintaining cellular homeostasis and is a potential target for regulating MSCs function. Therefore, this review focuses on the changes in autophagic activity of MSCs, clarifies the relationship between autophagy and health status of MSCs and the effect of autophagic activity on MSCs senescence and IPF, providing a theoretical basis for promoting the clinical application of MSCs.

TRAIL-Dependent Resolution of Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common form of interstitial lung disease characterized by the persistence of activated myofibroblasts resulting in excessive deposition of extracellular matrix proteins and profound tissue remodeling. In the present study, the expression of tumor necrosis factor- (TNF-) related apoptosis-inducing ligand (TRAIL) was key to the resolution of bleomycin-induced pulmonary fibrosis. Both in vivo and in vitro studies demonstrated that Gr-1⁺TRAIL⁺ bone marrow-derived myeloid cells blocked the activation of lung myofibroblasts. Although soluble TRAIL was increased in plasma from IPF patients, the presence of TRAIL⁺ myeloid cells was markedly reduced in IPF lung biopsies, and primary lung fibroblasts from this patient group expressed little of the TRAIL receptor-2 (DR5) when compared with appropriate normal samples. IL-13 was a potent inhibitor of DR5 expression in normal fibroblasts. Together, these results identified TRAIL⁺ myeloid cells as a critical mechanism in the resolution of pulmonary fibrosis, and strategies directed at promoting its function might have therapeutic potential in IPF.

A Systematic Review of the Role of Dysfunctional Wound Healing in the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disorder showcasing an interaction between genetic predisposition and environmental risks. This usually involves the coaction of a mixture of cell types associated with abnormal wound healing, leading to structural distortion and loss of gas exchange function. IPF bears fatal prognosis due to respiratory failure, revealing a median survival of approximately 2 to 3 years. This review showcases the ongoing progress in understanding the complex pathophysiology of IPF and it highlights the latest potential clinical treatments. In IPF, various components of the immune system, particularly clotting cascade and shortened telomeres, are highly involved in disease pathobiology and progression. This review also illustrates two US Food and Drug Administration (FDA)-approved drugs, nintedanib (OFEV, Boehringer Ingelheim, Ingelheim am Rhein, Germany) and pirfenidone (Esbriet, Roche, Basel, Switzerland), that slow IPF progression, but unfortunately neither drug can reverse the course of the disease. Although the mechanisms underlying IPF remain poorly understood, this review unveils the past and current advances that encourage the detection of new IPF pathogenic pathways and the development of effective treatment methods for the near future.

Patient considerations and drug selection in the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown cause. Approximately 5,000 people are diagnosed with IPF in the UK every year. People with IPF suffer significant morbidity and, without any curative treatment at present, survival rates remain poor with a median survival of 3 years. While treatment remains largely supportive, many drug therapies have been trialed in IPF over the years. Pirfenidone and nintedanib are newly licensed treatments for IPF and the first drugs to have shown convincing evidence of slowing disease progression. In addition to evaluating clinical evidence, we also discuss elements affecting drug choice from the viewpoint of patients and health care professionals. We discuss pharmacological and nonpharmacological aspects of providing best supportive care for patients with IPF. However, few good quality studies exist focusing on controlling symptoms specifically in patients with IPF, and recommendations are often extrapolated from evidence in other chronic diseases. In covering these topics, we hope to provide readers with a comprehensive review of the available evidence pertaining to all aspects of care for patients suffering with IPF.

Role and New Insights of Pirfenidone in Fibrotic Diseases

Pirfenidone (PFD) is a non-peptide synthetic molecule issued as a broad-spectrum anti-fibrotic drug with the ability to decrease TGF-β1, TNF-α, PDGF and COL1A1 expression, which is highly related to prevent or remove excessive deposition of scar tissue in several organs. Basic and clinical evidence suggests that PFD may safely slow or inhibit the progressive fibrosis swelling after tissue injuries. Furthermore, a number of evidence suggests that this molecule will have positive effects in the treatment of other inflammatory diseases. This review contains current research in which PFD has been used as the treatment of several diseases, and focus mainly in the outcomes related to improve inflammation and fibrogenesis. Therefore, the main goal of this review is to focus on the novel findings of PFD efficacy rather than deepen in the chemical aspects of the molecule.

Folate receptor expression on murine and human adipose tissue macrophages

OBJECTIVE AND DESIGN

Adipose tissue macrophages (ATMs) have been implicated in a number of obesity-related diseases. Because the activated macrophages associated with many types of autoimmune and inflammatory diseases express a folate receptor (FR) that can be exploited for FR-targeted drug delivery, we examined the visceral adipose tissue of obese mice and humans to determine whether ATMs also express FR that are accessible by folate conjugates.

MATERIAL OR SUBJECTS

C57BL/6 or FATSO mice fed on either a low- or high-fat diet were used in murine studies. Human adipose tissue were obtained from healthy volunteers during adipose reduction surgery.

METHODS

Visceral adipose tissue was collected from both obese mice and humans, collagenase digested, and stained with folate-Oregon Green and antibodies for macrophage markers including F4/80, mannose receptor (CD206), CD11b, and CD11c. Cells were then examined for expression of the above markers by flow cytometry. Furthermore, the ability of folate conjugates to target the FR-expressing ATMs in obese mice was evaluated in vivo.

RESULTS

A subset of the ATMs harvested from obese mice were found to express FR. Subpopulations of ATMs also simultaneously express both pro- and anti-inflammatory markers, and FR is expressed on both subsets. We then demonstrate that FR-expressing ATMs can be targeted with folate-linked fluorescent dyes in vivo.

CONCLUSIONS

FR are expressed on multiple subsets of ATMs and these subsets can be targeted with folate-linked drugs, allowing for the possible development of FR-targeted therapies for obesity-related inflammatory diseases.

New approaches to modulating idiopathic pulmonary fibrosis

Until recently, idiopathic pulmonary fibrosis (IPF) has been a devastating and generally fatal disease with no effective therapeutic. New developments in understanding the biology of the disease include a growing consensus that the lesions are mainly composed of cells that originated from resident fibroblasts. New developments in therapeutics include recommendations against several treatment regimes that have been previously used. On a positive note, the orally available drug pirfenidone has been approved for use in IPF in China, Japan, India, and the European Union, but not yet in the United States. Other possibilities for managing IPF include managing gastrointestinal reflux, and limiting excessive salt intake. A variety of potential therapeutics for IPF are in clinical trials; for instance, in a Phase 1b trial, intravenous injections of a recombinant version of the normal human serum protein Serum Amyloid P (SAP, also known as PTX2) improved lung function in IPF patients.

Inhibition of fibrosis and inflammation by triple therapy with pirfenidone, edaravone and erythropoietin in rabbits with drug-induced lung injury: comparison of CT imaging and pathological findings

In a rabbit model of bleomycin-induced lung injury, computed tomography (CT) and pathological studies were conducted to investigate whether the progression of this injury is inhibited by pirfenidone and by triple therapy with pirfenidone, edaravone and erythropoietin. We divided nine rabbits with bleomycin-induced lung injury into three equally sized groups. Group 1 served as the control, group 2 received pirfenidone alone and group 3 was treated with pirfenidone, edaravone and erythropoietin. Multidetector CT (MDCT) scans were acquired immediately after the administration of bleomycin, and further scans were performed on days 14 and 28. The area of abnormal opacity was calculated. The rabbit lungs were removed and the size of abnormal areas in macroscopic specimens was calculated and the degree of fibrosis and inflammation in microscopic specimens was scored. In order, the average size of the area of abnormal opacity on CT scans was largest in group 1, followed by groups 2 and 3. On day 28, the area of opacity was significantly smaller in group 3 than in group 1 (P=0.071). The average size of the area of abnormal opacity on macroscopic findings was largest in group 1, followed in order by groups 2 and 3; the difference between group 1 and 3 was significant (P<0.05). The average fibrosis score was highest in group 3 followed by groups 2 and 1. By contrast, the average inflammation score was highest in group 2 followed by groups 1 and 3. Although the administration of pirfenidone alone slowed the progression of bleomycin-induced lung injury, the triple-drug combination was more effective.

Regulation and Relevance of Myofibroblast Responses in Idiopathic Pulmonary Fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, incurable lung disease of unknown etiology with only limited treatment options. Current paradigms of disease pathogenesis feature recurrent or prolonged epithelial injury and an ensuing inflammatory response that culminates in the appearance of activated myofibroblasts. These cells are believed central to the excessive deposition of extracellular matrix that eventually obliterates the alveolar space to cause respiratory failure. Because the factors driving the accumulation of myofibroblasts remain poorly understood, effective therapies remain elusive. This review focuses on recent understanding of myofibroblasts including their seemingly uncontrolled proliferation and survival, their controversial origin in pathological IPF tissues, and the local biochemical and biomechanical matrix factors that drive their behavior. In addition, novel antifibrotics under development for the treatment of lung disease will be discussed. As our understanding of fibroblast and myofibroblast biology regulation expands, these cells may prove to be effective therapeutic targets.

Semaphorin 7a+ regulatory T cells are associated with progressive idiopathic pulmonary fibrosis and are implicated in transforming growth factor-β1-induced pulmonary fibrosis

RATIONALE

Lymphocytes are increasingly associated with idiopathic pulmonary fibrosis (IPF). Semaphorin 7a (Sema 7a) participates in lymphocyte activation.

OBJECTIVES

To define the relationship between Sema 7a and lymphocytes in IPF.

METHODS

We characterized the significance of Sema 7a+ lymphocytes in humans with IPF and in a mouse model of lung fibrosis caused by lung-targeted, transgenic overexpression of TGF-β1. We determined the site of Sema 7a expression in human and murine lungs and circulation and used adoptive transfer approaches to define the relevance of lymphocytes coexpressing Sema7a and the markers CD19, CD4, or CD4+CD25+FoxP3+ in TGF-β1-induced murine lung fibrosis.

MEASUREMENTS AND MAIN RESULTS

Subjects with IPF show expression of Sema 7a on lung CD4+ cells and circulating CD4+ or CD19+ cells. Sema 7a expression is increased on CD4+ cells and CD4+CD25+FoxP3+ regulatory T cells, but not CD19+ cells, in subjects with progressive IPF. Sema 7a is expressed on lymphocytes expressing CD4 but not CD19 in the lungs and spleen of TGF-β1-transgenic mice. Sema 7a expressing bone marrow-derived cells induce lung fibrosis and alter the production of T-cell mediators, including IFN-γ, IL-4, IL-17A, and IL-10. These effects require CD4 but not CD19. In comparison to Sema 7a-CD4+CD25+FoxP3+ cells, Sema7a+CD4+CD25+FoxP3+ cells exhibit reduced expression of regulatory genes such as IL-10, and adoptive transfer of these cells induces fibrosis and remodeling in the TGF-β1-exposed murine lung.

CONCLUSIONS

Sema 7a+CD4+CD25+FoxP3+ regulatory T cells are associated with disease progression in subjects with IPF and induce fibrosis in the TGF-β1-exposed murine lung.