Proteomics couples electrical remodelling to inflammation in a murine model of heart failure with sinus node dysfunction.

AIMS: In patients with heart failure (HF), concomitant sinus node dysfunction (SND) is an important predictor of mortality, yet its molecular underpinnings are poorly understood. Using proteomics, this study aimed to dissect the protein and phosphorylation remodelling within the sinus node in an animal model of HF with concurrent SND. METHODS AND RESULTS: We acquired deep sinus node proteomes and phosphoproteomes in mice with heart failure and SND and report extensive remodelling. Intersecting the measured (phospho)proteome changes with human genomics pharmacovigilance data, highlighted downregulated proteins involved in electrical activity such as the pacemaker ion channel, Hcn4. We confirmed the importance of ion channel downregulation for sinus node physiology using computer modelling. Guided by the proteomics data, we hypothesized that an inflammatory response may drive the electrophysiological remodeling underlying SND in heart failure. In support of this, experimentally induced inflammation downregulated Hcn4 and slowed pacemaking in the isolated sinus node. From the proteomics data we identified proinflammatory cytokine-like protein galectin-3 as a potential target to mitigate the effect. Indeed, in vivo suppression of galectin-3 in the animal model of heart failure prevented SND. CONCLUSION: Collectively, we outline the protein and phosphorylation remodeling of SND in heart failure, we highlight a role for inflammation in electrophysiological remodelling of the sinus node, and we present galectin-3 signalling as a target to ameliorate SND in heart failure.

The utility of transbronchial lung biopsies to guide the treatment decision in patients with rheumatic inflammatory diseases: a retrospective cross-sectional study.

The role of transbronchial lung biopsies (TBB) in the diagnostic workup of systemic inflammatory rheumatic disease-associated interstitial lung disease (SIRD-ILD) is unclear and TBB is not generally recommended. The study objective was to examine the utility of TBB to guide treatment in a population of patients with SIRD-ILD. All patients from the Department of Rheumatology, Rigshospitalet, Denmark, who had TBB performed, from 2002 to 2016 were identified. Patient demographics as well as smoking status, previous lung disease, pulmonary function test, SIRD-diagnosis, imaging results and immunomodulatory therapy pre- and post-bronchoscopy were obtained. Histology findings were used to dichotomize patients into a high-inflammatory group or a low-inflammatory group. The high-inflammation group primarily consisted of non-specific interstitial pneumonia, organizing pneumonia, lymphocytic infiltrating pneumonia and granulomatous inflammation whereas the low inflammation group primarily consisted of histological findings of usual interstitial pneumonitis and biopsies describing fibrosis and/or sparse unspecific inflammation. Therapeutic consequence was defined as intensification of therapy. Differences in treatment intensification were calculated using a binominal logistic regression model. Ninety-six patients had TBB performed. Biopsies from 55 patients were categorized as high inflammatory and 41 as low inflammatory, respectively. In the high-inflammatory group, 38 (69%) had their therapy intensified compared to 6 (14%) in the low-inflammatory group (Odds ratio 8.0, 95% confidence limits 3.2-20.0, P < 0.001). No procedure-related complications were registered. TBB findings can guide treatment strategy in SIRD-ILD patients with suspected activity in the pulmonary disease. TBB appears safe and could be considered as part of the diagnostic workup.