Cyclic GMP-AMP synthase expression is enhanced in systemic sclerosis-associated interstitial lung disease and stimulates inflammatory myofibroblast activation.

Objective: The lungs of patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) contain inflammatory myofibroblasts that arise in association with fibrotic stimuli and perturbed innate immunity. The cytosolic DNA-binding receptor cyclic GMP-AMP synthase (cGAS) is implicated in inflammation and fibrosis, but its involvement in SSc-ILD remains unknown. We examined cGAS expression, activity and therapeutic potential in SSc-ILD using human biospecimens, cultured fibroblasts, precision-cut lung slices and a well-accepted animal model.

Damage sensing through TLR9 regulates inflammatory and antiviral responses during influenza infection.

Host response aimed at eliminating the infecting pathogen, as well as the pathogen itself, can cause tissue injury. Tissue injury leads to the release of a myriad of cellular components including mitochondrial DNA (mtDNA), which the host senses through pattern recognition receptors. How the sensing of tissue injury by the host shapes the anti-pathogen response remains poorly understood.

A Nerve-Fibroblast Axis in Mammalian Lung Fibrosis.

Fibrosis contributes to incurable pathologies in vital organs including the lung. Myofibroblasts are fibrogenic effector cells that accumulate via incompletely understood mechanisms. We discovered that α1-adrenoreceptor expressing myofibroblasts receive sympathetic nerve-derived noradrenergic inputs in fibrotic mouse and human lungs.

cGAS Expression is Enhanced in Systemic Sclerosis Associated Interstitial Lung Disease and Stimulates Inflammatory Myofibroblast Activation.

Objective: The lungs of patients with Systemic Sclerosis Associated Interstitial Lung Disease (SSc-ILD) contain inflammatory myofibroblasts arising in association with fibrotic stimuli and perturbed innate immunity. The innate immune DNA binding receptor Cyclic GMP-AMP synthase (cGAS) is implicated in inflammation and fibrosis, but its involvement in SSc-ILD remains unknown. We examined cGAS expression, activity, and therapeutic potential in SSc-ILD using cultured fibroblasts, precision cut lung slices (PCLS), and a well-accepted animal model.

Toll-like Receptor 9 Inhibition Mitigates Fibroproliferative Responses in Translational Models of Pulmonary Fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA).

Objectives: We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor.

Plasma collagen neoepitopes are associated with multiorgan disease in the ACCESS and GRADS sarcoidosis cohorts.

Introduction: The pathogenesis of sarcoidosis involves tissue remodelling mediated by the accumulation of abnormal extracellular matrix, which is partly the result of an imbalance in collagen synthesis, cross-linking and degradation. During this process, collagen fragments or neoepitopes, are released into the circulation. The significance of these circulating collagen neoepitopes in sarcoidosis remains unknown.

Damage sensing through TLR9 Regulates Inflammatory and Antiviral Responses During Influenza Infection.

Host response aimed at eliminating the infecting pathogen, as well as the pathogen itself, can cause tissue injury. Tissue injury leads to the release of a myriad of cellular components including mitochondrial DNA, which the host senses through pattern recognition receptors. How the sensing of tissue injury by the host shapes the anti-pathogen response remains poorly understood.

Mitochondrial DNA Sensing Pathogen Recognition Receptors in Systemic Sclerosis Associated Interstitial Lung Disease: A Review.

Purpose Of The Review: Systemic sclerosis (SSc) is a condition of dermal and visceral scar formation characterized by immune dysregulation and inflammatory fibrosis. Approximately 90% of SSc patients develop interstitial lung disease (ILD), and it is the leading cause of morbidity and mortality. Further understanding of immune-mediated fibroproliferative mechanisms has the potential to catalyze novel treatment approaches in this difficult to treat disease.

Circulating Mitochondrial DNA Is Associated With High Levels of Fatigue in Two Independent Sarcoidosis Cohorts.

Background: Patients with sarcoidosis who develop severe clinical phenotypes of pulmonary fibrosis or multiorgan disease experience debilitating symptoms, with fatigue being a common chief complaint. Studies that have investigated this patient-related outcome measure (PROM) have used the Fatigue Assessment Scale (FAS), a self-reported questionnaire that reflects mental and physical domains. Despite extensive work, its cause is unknown and treatment options remain limited.

α1 Adrenoreceptor antagonism mitigates extracellular mitochondrial DNA accumulation in lung fibrosis models and in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis is increasingly associated with nerve-driven processes and endogenous innate immune ligands such as mitochondrial DNA (mtDNA). Interestingly, a connection between these entities has not been explored. Here, we report that noradrenaline (NA) derived from the lung's adrenergic nerve supply drives α-smooth muscle actin (αSMA)-expressing fibroblast accumulation via mechanisms involving α1 adrenoreceptors and mtDNA.

Natriuretic peptide receptor C contributes to disproportionate right ventricular hypertrophy in a rodent model of obesity-induced heart failure with preserved ejection fraction with pulmonary hypertension.

Heart failure with preserved ejection fraction (HFpEF) currently has no therapies that improve mortality. Right ventricular dysfunction and pulmonary hypertension are common in HFpEF, and thought to be driven by obesity and metabolic syndrome. Thus, we hypothesized that an animal model of obesity-induced HFpEF with pulmonary hypertension would provide insight into the pathogenesis of right ventricular failure in HFpEF.