Alterations in cardiovascular function in an experimental model of lung fibrosis and pulmonary hypertension

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

Unmasking a Silent Threat: Improving Pulmonary Hypertension Screening Methods for Interstitial Lung Disease Patients

This article provides a comprehensive overview of the latest literature on the diagnostics and treatment of pulmonary hypertension (PH) associated with interstitial lung disease (ILD). Heightened suspicion for PH arises when the advancement of dyspnoea in ILD patients diverges from the expected pattern of decline in pulmonary function parameters. The complexity of PH associated with ILD (PH-ILD) diagnostics is emphasized by the limitations of transthoracic echocardiography in the ILD population, necessitating the exploration of alternative diagnostic approaches. Cardiac magnetic resonance imaging (MRI) emerges as a promising tool, offering insights into hemodynamic parameters and providing valuable prognostic information. The potential of biomarkers, alongside pulmonary function and cardiopulmonary exercise tests, is explored for enhanced diagnostic and prognostic precision. While specific treatments for PH-ILD remain limited, recent studies on inhaled treprostinil provide new hope for improved patient outcomes.

The vascular perspective on acute and chronic lung disease

The pulmonary vasculature has been frequently overlooked in acute and chronic lung diseases, such as acute respiratory distress syndrome (ARDS), pulmonary fibrosis (PF), and chronic obstructive pulmonary disease (COPD). The primary emphasis in the management of these parenchymal disorders has largely revolved around the injury and aberrant repair of epithelial cells. However, there is increasing evidence that the vascular endothelium plays an active role in the development of acute and chronic lung diseases. The endothelial cell network in the capillary bed and the arterial and venous vessels provides a metabolically highly active barrier that controls the migration of immune cells, regulates vascular tone and permeability, and participates in the remodeling processes. Phenotypically and functionally altered endothelial cells, and remodeled vessels, can be found in acute and chronic lung diseases, although to different degrees, likely because of disease-specific mechanisms. Since vascular remodeling is associated with pulmonary hypertension, which worsens patient outcomes and survival, it is crucial to understand the underlying vascular alterations. In this Review, we describe the current knowledge regarding the role of the pulmonary vasculature in the development and progression of ARDS, PF, and COPD; we also outline future research directions with the hope of facilitating the development of mechanism-based therapies.

Sine oculis homeobox homolog 1 plays a critical role in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with limited treatment options. The role of the developmental transcription factor Sine oculis homeobox homolog 1 (SIX1) in the pathophysiology of lung fibrosis is not known. IPF lung tissue samples and IPF-derived alveolar type II cells (AT2) showed a significant increase in SIX1 mRNA and protein levels, and the SIX1 transcriptional coactivators EYA1 and EYA2 were elevated. Six1 was also upregulated in bleomycin-treated (BLM-treated) mice and in a model of spontaneous lung fibrosis driven by deletion of Telomeric Repeat Binding Factor 1 (Trf1) in AT2 cells. Conditional deletion of Six1 in AT2 cells prevented or halted BLM-induced lung fibrosis, as measured by a significant reduction in histological burden of fibrosis, reduced fibrotic mediator expression, and improved lung function. These effects were associated with increased macrophage migration inhibitory factor (MIF) in lung epithelial cells in vivo following SIX1 overexpression in BLM-induced fibrosis. A MIF promoter-driven luciferase assay demonstrated direct binding of Six1 to the 5'-TCAGG-3' consensus sequence of the MIF promoter, identifying a likely mechanism of SIX1-driven MIF expression in the pathogenesis of lung fibrosis and providing a potentially novel pathway for targeting in IPF therapy.

Idiopathic pulmonary fibrosis and pulmonary hypertension: Heracles meets the Hydra

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease where the additional presence of pulmonary hypertension (PH) reduces survival. In particular, the presence of coexistent pulmonary vascular disease in patients with advanced lung parenchymal disease results in worse outcomes than either diagnosis alone. This is true with respect to the natural histories of these diseases, outcomes with medical therapies, and even outcomes following lung transplantation. Consequently, there is a striking need for improved treatments for PH in the setting of IPF. In this review, we summarize existing therapies from the perspective of molecular mechanisms underlying lung fibrosis and vasoconstriction/vascular remodelling and discuss potential future targets for pharmacotherapy. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Dysregulation of BMP9/BMPR2/SMAD signalling pathway contributes to pulmonary fibrosis and pulmonary hypertension induced by bleomycin in rats

BACKGROUND AND PURPOSE

Pulmonary hypertension related to pulmonary fibrosis is classed as WHO Group III, one of the most common groups which lacks effective treatment options. In this study, we aimed to uncover the underlying mechanisms, particularly the involvement of the BMP9/BMPR2/SMAD signalling pathway, in this subtype of pulmonary hypertension.

EXPERIMENTAL APPROACH

Male Sprague Dawley rats were used to establish a model of pulmonary hypertension with pulmonary fibrosis, induced by bleomycin. Haemodynamic and lung functions were measured, along with histological and immunohistochemical examinations. Primary cultures of rat pulmonary microvascular endothelial cells (PMVECs) were analysed with western blots, apoptosis assays and immunohistochemistry.

KEY RESULTS

Early (7 days) after bleomycin treatment of rats, pulmonary arterial thickening and severe loss of pulmonary arterial endothelium were observed, followed (14 days) by increased right ventricular systolic pressure and right ventricular hypertrophy. Marked down-regulation of the BMP9/BMPR2/SMAD signalling pathway was markedly down-regulated in lung tissues from bleomycin-treated rats (throughout the 7- to 35-day treatment period) and bleomycin-treated rat PMVECs, along with excessive cell apoptosis and loss of pulmonary arterial endothelium. Treatment with recombinant human bone morphogenetic protein 9 (rhBMP9) attenuated these aspects of bleomycin-induced pulmonary hypertension, by restoring disrupted BMP9/BMPR2/SMAD signalling.

CONCLUSION AND IMPLICATIONS

In bleomycin-treated rats, early and persisting suppression of the BMP9/BMPR2/SMAD signalling pathway triggered severe loss of pulmonary arterial endothelium and subsequent pulmonary arterial vascular remodelling, contributing to the development of pulmonary hypertension. Therapeutic approaches reinforcing BMP9/BMPR2/SMAD signalling might be ideal strategies for this subtype of pulmonary hypertension.

LINKED ARTICLES

This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.