Pirfenidone in idiopathic pulmonary fibrosis: the CAPACITY program

Exercise and tissue fibrosis: recent advances in therapeutic potential and molecular mechanisms

Tissue fibrosis represents an aberrant repair process, occurring because of prolonged injury, sustained inflammatory response, or metabolic disorders. It is characterized by an excessive accumulation of extracellular matrix (ECM), resulting in tissue hardening, structural remodeling, and loss of function. This pathological phenomenon is a common feature in the end stage of numerous chronic diseases. Despite the advent of novel therapeutic modalities, including antifibrotic agents, these have only modest efficacy in reversing established fibrosis and are associated with adverse effects. In recent years, a growing body of research has demonstrated that exercise has significant benefits and potential in the treatment of tissue fibrosis. The anti-fibrotic effects of exercise are mediated by multiple mechanisms, including direct inhibition of fibroblast activation, reduction in the expression of pro-fibrotic factors such as transforming growth factor-β (TGF-β) and slowing of collagen deposition. Furthermore, exercise has been demonstrated to assist in maintaining the dynamic equilibrium of tissue repair, thereby indirectly reducing tissue damage and fibrosis. It can also help maintain the dynamic balance of tissue repair by improving metabolic disorders, exerting anti-inflammatory and antioxidant effects, regulating cellular autophagy, restoring mitochondrial function, activating stem cell activity, and reducing cell apoptosis, thereby indirectly alleviating tissue. This paper presents a review of the therapeutic potential of exercise and its underlying mechanisms for the treatment of a range of tissue fibrosis, including cardiac, pulmonary, renal, hepatic, and skeletal muscle. It offers a valuable reference point for non-pharmacological intervention strategies for the comprehensive treatment of fibrotic diseases.

Modelling and targeting mechanical forces in organ fibrosis

Few efficacious therapies exist for the treatment of fibrotic diseases, such as skin scarring, liver cirrhosis and pulmonary fibrosis, which is related to our limited understanding of the fundamental causes and mechanisms of fibrosis. Mechanical forces from cell-matrix interactions, cell-cell contact, fluid flow and other physical stimuli may play a central role in the initiation and propagation of fibrosis. In this Review, we highlight the mechanotransduction mechanisms by which various sources of physical force drive fibrotic disease processes, with an emphasis on central pathways that may be therapeutically targeted to prevent and reverse fibrosis. We then discuss engineered models of mechanotransduction in fibrosis, as well as molecular and biomaterials-based therapeutic approaches for limiting fibrosis and promoting regenerative healing phenotypes in various organs. Finally, we discuss challenges within fibrosis research that remain to be addressed and that may greatly benefit from next-generation bioengineered model systems.

Hyperpolarized 129Xe MR Spectroscopy in the Lung Shows 1-year Reduced Function in Idiopathic Pulmonary Fibrosis

Background Idiopathic pulmonary fibrosis (IPF) is a temporally and spatially heterogeneous lung disease. Identifying whether IPF in a patient is progressive or stable is crucial for treatment regimens. Purpose To assess the role of hyperpolarized (HP) xenon 129 (129Xe) MRI measures of ventilation and gas transfer in IPF generally and as an early signature of future IPF progression. Materials and Methods In a prospective study, healthy volunteers and participants with IPF were consecutively recruited between December 2015 and August 2019 and underwent baseline HP 129Xe MRI and chest CT. Participants with IPF were followed up with forced vital capacity percent predicted (FVC%p), diffusing capacity of the lungs for carbon monoxide percent predicted (DLco%p), and clinical outcome at 1 year. IPF progression was defined as reduction in FVC%p by at least 10%, reduction in DLco%p by at least 15%, or admission to hospice care. CT and MRI were spatially coregistered and a measure of pulmonary gas transfer (red blood cell [RBC]-to-barrier ratio) and high-ventilation percentage of lung volume were compared across groups and across fibrotic versus normal-appearing regions at CT by using Wilcoxon signed rank tests. Results Sixteen healthy volunteers (mean age, 57 years ± 14 [SD]; 10 women) and 22 participants with IPF (mean age, 71 years ± 9; 15 men) were evaluated, as follows: nine IPF progressors (mean age, 72 years ± 7; five women) and 13 nonprogressors (mean age, 70 years ± 10; 11 men). Reduction of high-ventilation percent (13% ± 6.1 vs 8.2% ± 5.9; P = .03) and RBC-to-barrier ratio (0.26 ± 0.06 vs 0.20 ± 0.06; P = .03) at baseline were associated with progression of IPF. Participants with progressive disease had reduced RBC-to-barrier ratio in structurally normal-appearing lung at CT (0.21 ± 0.07 vs 0.28 ± 0.05; P = .01) but not in fibrotic regions of the lung (0.15 ± 0.09 vs 0.14 ± 0.04; P = .62) relative to the nonprogressive group. Conclusion In this preliminary study, functional measures of gas transfer and ventilation measured with xenon 129 MRI and the extent of fibrotic structure at CT were associated with idiopathic pulmonary fibrosis disease progression. Differences in gas transfer were found in regions of nonfibrotic lung. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gleeson and Fraser in this issue.

Identification and validation of ADME genes as prognosis and therapy markers for hepatocellular carcinoma patients

Purpose: ADME genes are genes involved in drug absorption, distribution, metabolism, and excretion (ADME). Previous studies report that expression levels of ADME-related genes correlate with prognosis of hepatocellular carcinoma (HCC) patients. However, the role of ADME gene expression on HCC prognosis has not been fully explored. The present study sought to construct a prediction model using ADME-related genes for prognosis of HCC.

Methods: Transcriptome and clinical data were retrieved from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC), which were used as training and validation cohorts, respectively. A prediction model was constructed using univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) analysis. Patients were divided into high- and low-risk groups based on the median risk score. The predictive ability of the risk signature was estimated through bioinformatics analyses.

Results: Six ADME-related genes (CYP2C9, ABCB6, ABCC5, ADH4, DHRS13, and SLCO2A1) were used to construct the prediction model with a good predictive ability. Univariate and multivariate Cox regression analyses showed the risk signature was an independent predictor of overall survival (OS). A single-sample gene set enrichment analysis (ssGSEA) strategy showed a significant relationship between risk signature and immune status. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed differentially expressed genes (DEGs) in the high- and low-risk groups were enriched in biological process (BP) associated with metabolic and cell cycle pathways.

Conclusion: A prediction model was constructed using six ADME-related genes for prediction of HCC prognosis. This signature can be used to improve HCC diagnosis, treatment, and prognosis in clinical use.

Interleukin-36 Cytokine/Receptor Signaling: A New Target for Tissue Fibrosis

Tissue fibrosis is a major unresolved medical problem, which impairs the function of various systems. The molecular mechanisms involved are poorly understood, which hinders the development of effective therapeutic strategies. Emerging evidence from recent studies indicates that interleukin 36 (IL-36) and the corresponding receptor (IL-36R), a newly-characterized cytokine/receptor signaling complex involved in immune-inflammation, play an important role in the pathogenesis of fibrosis in multiple tissues. This review focuses on recent experimental findings, which implicate IL-36R and its associated cytokines in different forms of organ fibrosis. Specifically, it outlines the molecular basis and biological function of IL-36R in normal cells and sums up the pathological role in the development of fibrosis in the lung, kidney, heart, intestine, and pancreas. We also summarize the new progress in the IL-36/IL-36R-related mechanisms involved in tissue fibrosis and enclose the potential of IL-36R inhibition as a therapeutic strategy to combat pro-fibrotic pathologies. Given its high association with disease, gaining new insight into the immuno-mechanisms that contribute to tissue fibrosis could have a significant impact on human health.

Tanshinone IIA attenuates silica-induced pulmonary fibrosis via Nrf2-mediated inhibition of EMT and TGF-β1/Smad signaling

Silicosis is an occupational pulmonary fibrosis that is caused by inhalation of silica (SiO₂), and there are no effective drugs to treat this disease. Tanshinone IIA (Tan IIA), a natural product, has been reported to possess antioxidant and anti-fibrotic properties in various diseases. The purpose of the current study was to examine Tan IIA's protective effects against silica-induced pulmonary fibrosis and to explore the underlying mechanisms. We found that in vivo treatment with Tan IIA significantly relieved silica-induced lung fibrosis in a silicosis rat model by histological and immunohistochemical analyses. Further, in vitro mechanistic investigations, mainly using western blot and immunofluorescence analyses, revealed that Tan IIA administration markedly inhibited the silica-induced epithelial-mesenchymal transition (EMT) and transforming growth factor-β1 (TGF-β1)/Smad signaling pathway and also reduced silica-induced oxidative stress and activated the nuclear factor erythroid 2-related factor-2 (Nrf2) signaling pathway in A549 and human bronchial epithelial (HBE) cells. Furthermore, through transfection with siRNA, we demonstrate that Nrf2 activation partially mediates the suppression effects of Tan IIA on EMT and TGF-β1/Smad signaling pathway activation induced by silica exposure, thus mediating the anti-fibrotic effects of Tan IIA against silica-induced pulmonary fibrosis. In our study, Tan IIA has been identified as a possible anti-oxidative and anti-fibrotic drug for silicosis.

Galectin-3 as a candidate upstream biomarker for quantifying risks of myocardial ageing

AIMS

Galectin-3 (Gal-3) is implicated in the pathogenesis of heart failure and is also influenced by ageing. This study aims to determine the extent to which Gal-3 levels estimate odds of myocardial dysfunction in ageing cohorts, 'upstream' prior to clinical disease.

METHODS AND RESULTS

Four hundred seventy-five asymptomatic subjects underwent simultaneous assessments of cardiovascular structure and function, with measurements of circulating Gal-3. Myocardial dysfunction was defined as impaired myocardial relaxation (ratio of peak velocity flow in early diastole E (m/s) to peak velocity flow in late diastole by atrial contraction A (m/s) <0.84) (mean E/A ratio 0.84 in the cohort). Of 475 subjects (mean age 68 ± 12 years, 231 women), 222 (47%) had myocardial dysfunction. Subjects with myocardial dysfunction were older (mean age 73 ± 5 vs. 64 ± 14 years, P < 0.0001), and more had hypertension (59 vs. 40%, P < 0.0001), dyslipidaemia (54 vs. 39%, P = 0.001), diabetes mellitus (25 vs. 14%, P = 0.002), higher body mass index (BMI) (24 vs. 23 kg/m² , P = 0.002), and higher heart rate (76 vs. 71 b.p.m., P = 0.0001). Participants with impaired myocardial relaxation had lower peak velocity flow in early diastole E (0.6 ± 0.1 vs. 0.8 ± 0.2 m/s, P < 0.0001), higher peak velocity flow in late diastole by atrial contraction A (0.9 ± 0.1 vs. 0.7 ± 0.2 m/s, P < 0.0001), and higher mitral valve flow deceleration time (224.7 ± 43.2 vs. 204.8 ± 33.1 m/s, P < 0.0001). Participants with impaired myocardial relaxation had higher Gal-3 levels (17.2 ± 6.2 vs. 15.5 ± 4.1, P = 0.0004) but similar B-type natriuretic peptide (37 ± 4 vs. 34 ± 29, P = 0.37) and high-sensitivity troponin I (21 ± 72 vs. 11 ± 41, P = 0.061) levels and urine microalbumin-to-creatinine ratio (4.6 ± 8.1 vs. 4.2 ± 10.8, P = 0.75) compared with those without impaired myocardial relaxation. After multivariable adjustments, Gal-3 [odds ratio (OR) 1.05, 95% confidence interval (CI) 1.00-1.10, P = 0.039], age (OR 2.60, 95% CI 1.64-4.11, P < 0.0001), BMI (OR 2.16, 95% CI 1.44-3.23, P < 0.0001), and heart rate (OR 1.04, 95% CI 1.02-1.06, P < 0.0001) were associated with impaired myocardial relaxation. Adjusted ORs (95% CI) for myocardial dysfunction were 1.0 (ref), 1.62 (0.92-2.85), 1.92 (1.08-3.41), and 2.01 (1.11-3.66) across consecutive quartiles of Gal-3 after adjustment for age, BMI, risk factors, and heart rate.

CONCLUSIONS

Among asymptomatic community-dwelling elderly adults, the highest quartile of Gal-3 was associated with two-fold increased odds of myocardial dysfunction compared with the lowest quartile of Gal-3. Gal-3 may have a role as an 'upstream' biomarker in estimating odds of myocardial ageing prior to clinical disease.

Efficacy of pirfenidone for the treatment of pulmonary fibrosis: An updated systematic review protocol of randomized controlled trial

BACKGROUND

This study will systematically assess the efficacy and safety of pirfenidone for the treatment of patients with pulmonary fibrosis (PF).

METHODS

We will search potential records from following literature sources from their inceptions to the present without language, and publication status limitations: Cochrane Library, EMBASE, PUBMED, the Cumulative Index to Nursing and Allied Health Literature, the Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. In addition, we also search grey literature sources, such as dissertations, conference proceedings, as well as the reference lists of included studies. All randomized controlled trials related to the pirfenidone for treating PF will be included. All the process of study selection, data extraction, and methodological evaluation will be carried out by 2 authors independently. The primary outcome comprises of all-cause-mortality, and lung function status, as measured by forced vital capacity. The secondary outcomes consist of 6-minute walk distance, progression-free survival, dyspnea, acute exacerbation, quality of life, and adverse events. Whenever possible, all results data will be pooled and meta-analysis will be performed.

RESULTS

This study will systematically assess the efficacy and safety of pirfenidone for the treatment of patients with PF.

CONCLUSION

The findings of the present study will summarize most recent evidence of pirfenidone for PF.

ETHICS AND DISSEMINATION

No individual data will be analyzed in this study, thus, no research ethics approval is required in this study. The findings of this study are expected to be disseminated in a peer-reviewed journal or conference presentations.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019126958.

Efficacy and adverse events of pirfenidone in treating idiopathic pulmonary fibrosis

Objectives:

To analyze the efficacy and adverse events (AEs) of pirfenidone in idiopathic pulmonary fibrosis (IPF) trials.

Methods:

MEDLINE, Cochrane Library, and ClinicalTrials.gov were searched for studies published before June 2016. All studies of clinical trials with the key words IPF or idiopathic pulmonary fibrosis or lung fibrosis and pirfenidone or Esbriet were identified. Quality assessment and data extraction were conducted by 2 independent researchers. A meta-analysis of randomized controlled trials (RCTs) was performed, and relative risk (RR) and 95% confidence intervals (95% CIs) were calculated.

Results:

Five studies were included in this review, involving 1568 participants. The meta-analysis revealed that pirfenidone reduced the risk of decline in forced vital capacity (FVC)% ≥10% from baseline (relative risk: 0.62; 95% CI: 0.51-0.76, p<0.001). The pirfenidone group had a significantly higher rate of AEs compared with the placebo group. Pirfenidone did not reduce mortality from any cause significantly (odds ratio: 0.63; 95% CI: 0.36-1.09).

Conclusions:

This study showed that pirfenidone could reduce disease progression as assessed by the decline in FVC in IPF. Pirfenidone represents a suitable treatment option for patients with IPF.

Epithelial cell-derived cytokines CST3 and GDF15 as potential therapeutics for pulmonary fibrosis

While wound healing is completed, the epithelium functions to normalize the interstitial context by eliminating fibroblasts excited during matrix reconstruction. If not, tissues undergo pathologic fibrosis. Pulmonary fibrosis is a fatal and hardly curable disorder. We here tried to identify epithelium-derived cytokines capable of ameliorating pulmonary fibrosis. Human lung fibroblasts were inactivated in epithelial cell-conditioned media. Cystatin C (CST3) and growth differentiation factor 15 (GDF15) were found to be enriched in the conditioned media and to inhibit the growth and activation of lung fibroblasts by inactivating the TGF–Smad pathway. In mouse and human lungs with interstitial fibrosis, CST3 and GDF15 expressions were markedly reduced, and the restoration of these cytokines alleviated the fibrotic changes in mouse lungs. These results suggest that CST3 and GDF15 are bona fide regulators to prevent excessive proliferation and activation of fibroblasts in injured lungs. These cytokines could be potential therapeutics for ameliorating interstitial lung fibrosis.

Serum surfactant protein D predicts the outcome of patients with idiopathic pulmonary fibrosis treated with pirfenidone

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a fatal pulmonary disease with poor prognosis. Pirfenidone, the first antifibrotic drug, suppresses the decline in forced vital capacity (FVC) and improves prognosis in some, but not all, patients with IPF; therefore, an indicator for identifying improved outcomes in pirfenidone therapy is desirable. This study aims to clarify whether baseline parameters can be predictors of disease progression and prognosis in patients with IPF treated with pirfenidone.

METHODS

We retrospectively investigated patients with IPF who started treatment with pirfenidone between December 2008 and November 2014 at the Sapporo Medical University Hospital. Patients treated with pirfenidone for ≥6 months were enrolled in this study and were observed until November 2015. We investigated the association of clinical characteristics, pulmonary function test results, and blood examination results at the start of pirfenidone with the outcome of patients.

RESULTS

Sixty patients were included in this study. In multivariate logistic regression analysis, % predicted FVC and serum surfactant protein (SP)-D levels were predictors of a ≥10% decline in FVC in the initial 12 months. In the Cox proportional hazards model, these two factors predicted progression-free survival. Pack-years, % predicted diffusing capacity for carbon monoxide, and SP-D levels predicted overall survival.

CONCLUSIONS

The serum SP-D level was a predictor of disease progression and prognosis in patients with IPF treated with pirfenidone. In addition, this analysis describes the relative usefulness of other clinical parameters at baseline in estimating the prognosis of patients with IPF who are candidates for pirfenidone therapy.

Earthworm extract attenuates silica-induced pulmonary fibrosis through Nrf2-dependent mechanisms

Silicosis is an occupational pulmonary fibrosis caused by inhalation of silica (SiO₂) and there are no ideal drugs to treat this disease. Earthworm extract (EE), a natural nutrient, has been reported to have anti-inflammatory, antioxidant, and anti-apoptosis effects. The purpose of the current study was to test the protective effects of EE against SiO₂-induced pulmonary fibrosis and to explore the underlying mechanisms using both in vivo and in vitro models. We found that treatment with EE significantly reduced lung inflammation and fibrosis and improved lung structure and function in SiO₂-instilled mice. Further mechanistic investigations revealed that EE administration markedly inhibited SiO₂-induced oxidative stress, mitochondrial apoptotic pathway, and epithelial-mesenchymal transition in HBE and A549 cells. Furthermore, we demonstrate that Nrf2 activation partly mediates the interventional effects of EE against SiO₂-induced pulmonary fibrosis. Our study has identified EE to be a potential anti-oxidative, anti-inflammatory, and anti-fibrotic drug for silicosis.

Skin fibrosis: Models and mechanisms

Matrix synthesis, deposition and remodeling are complex biological processes that are critical in development, maintenance of tissue homeostasis and repair of injured tissues. Disturbances in the regulation of these processes can result in severe pathological conditions which are associated with tissue fibrosis as e.g. in Scleroderma, cutaneous Graft-versus-Host-Disease, excessive scarring after trauma or carcinogenesis. Therefore, finding efficient treatments to limit skin fibrosis is of major clinical importance. However the pathogenesis underlying the development of tissue fibrosis is still not entirely resolved. In recent years progress has been made unraveling the complex cellular and molecular mechanisms that determine fibrosis. Here we provide an overview of established and more recently developed mouse models that can be used to investigate the mechanisms of skin fibrosis and to test potential therapeutic approaches.

[Mechanism of and Therapy for Kidney Fibrosis]

Fibrosis occurs in systemic tissues other than the brain and finally induces dysfunction of the fibrotic organ. Kidney fibrosis is related to scarring after acute kidney injury and the progression of chronic kidney disease. Kidney function decreases with the progression of kidney fibrosis. As fibrotic tissue cannot return to its original status, advanced kidney fibrosis requires the administration of dialysis or kidney transplantation. Thus, elucidation the mechanism of kidney fibrosis is an important research theme. The proliferation and activation of (myo) fibroblasts and the excessive production of an extracellular matrix are common mechanisms in fibrosis in many organs, but it seems that kidney fibrosis has specific pathways. Tubular epithelial, mesangial cells, and erythropoietin producing cells, which exist only in the kidney, participate in forming kidney fibrosis. This review highlights an understanding of the cells and their underlying mechanisms, which are specific to kidney fibrosis process: transforming growth factor-β (TGF-β), epithelial-mesenchymal transition, wingless/int-1 (WNT) signaling, renal anemia, and uremia. Finally, we describe potential therapies that focus on the mechanisms of kidney fibrosis: anti-TGF-β antibody and mammalian target of rapamycin (mTOR).

Fibrosis-related biomarkers and large and small vessel disease: the Cardiovascular Health Study

OBJECTIVE

Fibrosis has been implicated in a number of pathological, organ-based conditions of the liver, kidney, heart, and lungs. The objective of this study was to determine whether biomarkers of fibrosis are associated with vascular disease in the large and/or small vessels.

METHODS

We evaluated the associations of two circulating biomarkers of fibrosis, transforming growth factor-β (TGF-β) and procollagen type III N-terminal propeptide (PIIINP), with incident peripheral artery disease (PAD) and subclinical macrovascular (carotid intima-media thickness, flow-mediated vasodilation, ankle-brachial index, retinal vein diameter), and microvascular (retinal artery diameter and retinopathy) disease among older adults in the Cardiovascular Health Study. We measured TGF-β and PIIINP from samples collected in 1996 and ascertained clinical PAD through 2011. Measurements of large and small vessels were collected between 1996 and 1998.

RESULTS

After adjustment for sociodemographic, clinical, and biochemical risk factors, TGF-β was associated with incident PAD (hazard ratio [HR] = 1.36 per doubling of TGF-β, 95% confidence interval [CI] = 1.04, 1.78) and retinal venular diameter (1.63 μm per doubling of TGF-β, CI = 0.23, 3.02). PIIINP was not associated with incident PAD, but was associated with carotid intima-media thickness (0.102 mm per doubling of PIIINP, CI = 0.029, 0.174) and impaired brachial artery reactivity (-0.20% change per doubling of PIIINP, CI = -0.39, -0.02). Neither TGF-β nor PIIINP were associated with retinal arteriolar diameter or retinopathy.

CONCLUSIONS

Serum concentrations of fibrosis-related biomarkers were associated with several measures of large vessel disease, including incident PAD, but not with small vessel disease. Fibrosis may contribute to large vessel atherosclerosis in older adults.

Outcome Measures for Clinical Trials in Interstitial Lung Diseases

The chronic fibrosing idiopathic interstitial pneumonias (IIPs) are a group of heterogeneous pulmonary parenchymal disorders described by radiologic and histological patterns termed usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP). These include idiopathic pulmonary fibrosis (IPF) and those related to connective tissue disease (CTD) and are associated with substantial morbidity and mortality. Beyond the importance of establishing an appropriate diagnosis, designing optimal clinical trials for IIPs has been fraught with difficulties in consistency of clinical endpoints making power analyses, and the establishment of efficacy and interpretation of results across trials challenging. Preliminary recommendations, developed by rigorous consensus methods, proposed a minimum set of outcome measures, a 'core set', to be incorporated into future clinical trials (Saketkoo et al, THORAX. 2014.). This paper sets out to examine the candidate instruments for each domain (Dyspnea, Cough, Health Related Quality of Life, Imaging, Lung Physiology and Function, Mortality). Candidate measures that were not selected as well as measures that were not available for examination at the time of the consensus process will also be discussed.

Fibrosis-related biomarkers and incident cardiovascular disease in older adults: the cardiovascular health study

BACKGROUND

Fibrotic changes in the heart and arteries have been implicated in a diverse range of cardiovascular diseases (CVD), but whether circulating biomarkers that reflect fibrosis are associated with CVD is unknown.

METHODS AND RESULTS

We determined the associations of 2 biomarkers of fibrosis, transforming growth factor- β (TGF-β), and procollagen type III N-terminal propeptide (PIIINP), with incident heart failure, myocardial infarction, and stroke among community-living older adults in the Cardiovascular Health Study. We measured circulating TGF-β (n=1371) and PIIINP (n=2568) from plasma samples collected in 1996 and ascertained events through 2010. Given TGF-β's pleiotropic effects on inflammation and fibrogenesis, we investigated potential effect modification by C-reactive protein in secondary analyses. After adjustment for sociodemographic, clinical, and biochemical risk factors, PIIINP was associated with total CVD (hazard ratio [HR] per SD=1.07; 95% confidence interval [CI], 1.01-1.14) and heart failure (HR per SD=1.08; CI, 1.01-1.16) but not myocardial infarction or stroke. TGF-β was not associated with any CVD outcomes in the full cohort but was associated with total CVD (HR per SD=1.16; CI, 1.02-1.31), heart failure (HR per SD=1.16; CI, 1.01-1.34), and stroke (HR per SD=1.20; CI, 1.01-1.42) among individuals with C-reactive protein above the median, 2.3 mg/L (P interaction <0.05).

CONCLUSIONS

Our findings provide large-scale, prospective evidence that circulating biomarkers of fibrosis, measured in community-living individuals late in life, are associated with CVD. Further research on whether TGF-β has a stronger fibrogenic effect in the setting of inflammation is warranted.

Fibrosis-related biomarkers and risk of total and cause-specific mortality: the cardiovascular health study

Fibrosis has been implicated in diverse diseases of the liver, kidney, lungs, and heart, but its importance as a risk factor for mortality remains unconfirmed. We determined the prospective associations of 2 complementary biomarkers of fibrosis, transforming growth factor-β (TGF-β) and procollagen type III N-terminal propeptide (PIIINP), with total and cause-specific mortality risks among community-living older adults in the Cardiovascular Health Study (1996-2010). We measured circulating TGF-β and PIIINP levels in plasma samples collected in 1996 and ascertained the number of deaths through 2010. Both TGF-β and PIIINP were associated with elevated risks of total and pulmonary mortality after adjustment for sociodemographic, clinical, and biochemical risk factors. For total mortality, the hazard ratios per doubling of TGF-β and PIIINP were 1.09 (95% confidence interval (CI): 1.01, 1.17; P = 0.02) and 1.14 (CI: 1.03, 1.27; P = 0.01), respectively. The corresponding hazard ratios for pulmonary mortality were 1.27 (CI: 1.01, 1.60; P = 0.04) for TGF-β and 1.52 (CI: 1.11, 2.10; P = 0.01) for PIIINP. Associations of TGF-β and PIIINP with total and pulmonary mortality were strongest among individuals with higher C-reactive protein concentrations (P for interaction < 0.05). Our findings provide some of the first large-scale prospective evidence that circulating biomarkers of fibrosis measured late in life are associated with death.

The profibrotic role of endothelin-1: is the door still open for the treatment of fibrotic diseases?

The endothelin (ET) system consists of two G-protein-coupled receptors (ETA and ETB), three peptide ligands (ET-1, ET-2 and ET-3), and two activating peptidases (endothelin-converting enzyme-, ECE-1 and ECE-2). While initially described as a vasoregulatory factor, shown to influence several cardiovascular diseases, from hypertension to heart failure, ET-1, the predominant form in most cells and tissues, has expanded its pathophysiological relevance by recent evidences implicating this factor in the regulation of fibrosis. In this article, we review the current knowledge of the role of ET-1 in the development of fibrosis, with particular focus on the regulation of its biosynthesis and the molecular mechanisms involved in its profibrotic actions. We summarize also the contribution of ET-1 to fibrotic disorders in several organs and tissues. The development and availability of specific ET receptor antagonists have greatly stimulated a number of clinical trials in these pathologies that unfortunately have so far given negative or inconclusive results. This review finally discusses the circumstances underlying these disappointing results, as well as provides basic and clinical researchers with arguments to keep exploring the complex physiology of ET-1 and its therapeutic potential in the process of fibrosis.

Targeting the epithelial cells in fibrosis: a new concept for an old disease

Fibrosis, which affects millions of individuals worldwide, is a leading cause of organ failure. For 40 years myofibroblasts have been recognized to be the key cellular players in fibrosis. Currently, several pharmaceutical targets are under investigation that may contribute to the activation of myofibroblasts. Recent preclinical and clinical evidence suggests that other components in the fibrotic microenvironment can trigger myofibroblast activation, providing new targets for pharmaceutical intervention. Epithelial cells may represent the most promising cellular phenotype that could be exploited in the design of new anti-fibrotic medicines through their paracrine action on myofibroblasts. The present review briefly highlights this hypothesis and discusses some interesting related pharmacological targets.

Mechanisms of fibrosis: therapeutic translation for fibrotic disease

Fibrosis is a pathological feature of most chronic inflammatory diseases. Fibrosis, or scarring, is defined by the accumulation of excess extracellular matrix components. If highly progressive, the fibrotic process eventually leads to organ malfunction and death. Fibrosis affects nearly every tissue in the body. Here we discuss how key components of the innate and adaptive immune response contribute to the pathogenesis of fibrosis. We also describe how cell-intrinsic changes in important structural cells can perpetuate the fibrotic response by regulating the differentiation, recruitment, proliferation and activation of extracellular matrix-producing myofibroblasts. Finally, we highlight some of the key mechanisms and pathways of fibrosis that are being targeted as potential therapies for a variety of important human diseases.

Mechanisms of fibrosis: therapeutic translation for fibrotic disease

Fibrosis is a pathological feature of most chronic inflammatory diseases. Fibrosis, or scarring, is defined by the accumulation of excess extracellular matrix components. If highly progressive, the fibrotic process eventually leads to organ malfunction and death. Fibrosis affects nearly every tissue in the body. Here we discuss how key components of the innate and adaptive immune response contribute to the pathogenesis of fibrosis. We also describe how cell-intrinsic changes in important structural cells can perpetuate the fibrotic response by regulating the differentiation, recruitment, proliferation and activation of extracellular matrix-producing myofibroblasts. Finally, we highlight some of the key mechanisms and pathways of fibrosis that are being targeted as potential therapies for a variety of important human diseases.

Epidemiology and management of common pulmonary diseases in older persons

Pulmonary disease prevalence increases with age and contributes to morbidity and mortality in older patients. Dyspnea in older patients is often ascribed to multiple etiologies such as medical comorbidities and deconditioning. Common pulmonary disorders are frequently overlooked as contributors to dyspnea in older patients. In addition to negative impacts on morbidity and mortality, quality of life is reduced in older patients with uncontrolled, undertreated pulmonary symptoms. The purpose of this review is to discuss the epidemiology of common pulmonary diseases, namely pneumonia, chronic obstructive pulmonary disease, asthma, lung cancer, and idiopathic pulmonary fibrosis in older patients. We will review common clinical presentations for these diseases and highlight differences between younger and older patients. We will also briefly discuss risk factors, treatment, and mortality associated with these diseases. Finally, we will address the relationship between comorbidities, pulmonary symptoms, and quality of life in older patients with pulmonary diseases.

Pirfenidone treatment of idiopathic pulmonary fibrosis

Pirfenidone is the first antifibrotic agent to be approved for the treatment of pulmonary fibrosis. Idiopathic pulmonary fibrosis (IPF) is one of the idiopathic interstitial pneumonias with the worst prognoses; approximately half of patients die within 3–5 years, and the need for an effective treatment has been unmet until recently. The etiology of IPF is still unknown and its pathogenesis is poorly understood. Anti-inflammatory drugs, such as corticosteroids and some immunosuppressants, have been empirically used to treat IPF, although they have not been objectively proven to be effective by large-scale randomized, controlled trials. Pirfenidone is an agent that can inhibit the decline of forced vital capacity (FVC)/vital capacity (VC) and that thereby can be hoped to decrease the mortality rate. The number of clinical trials of pirfenidone completed, ongoing, or planned is growing, and the present status of pirfenidone as treatment for IPF is summarized in this review.

Idiopathic pulmonary fibrosis: pathobiology of novel approaches to treatment

Idiopathic pulmonary fibrosis (IPF) is a progressive disease of unknown cause that conveys a dismal prognosis. In the United States there are currently no licensed therapies for treatment of IPF. The development of effective IPF clinical trials networks across the United States and Europe, however, has led to key developments in the treatment of IPF. Advances in understanding of the pathogenetic processes involved in the development of pulmonary fibrosis have led to novel therapeutic targets. These developments offer hope that there may, in the near future, be therapeutic options available for treatment of this devastating disease.