A Proof of Principle 2D Spatial Proteome Mapping Analysis Reveals Distinct Regional Differences in the Cardiac Proteome.

Proteomics studies often explore phenotypic differences between whole organs and systems. Within the heart, more subtle variation exists. To date, differences in the underlying proteome are only described between whole cardiac chambers. This study, using the bovine heart as a model, investigates inter-regional differences and assesses the feasibility of measuring detailed, cross-tissue variance in the cardiac proteome. Using a bovine heart, we created a two-dimensional section through a plane going through two chambers. This plane was further sectioned into 4 × 4 mm cubes and analysed using label-free proteomics. We identified three distinct proteomes. When mapped to the extracted sections, the proteomes corresponded largely to the outer wall of the right ventricle and secondly to the outer wall of the left ventricle, right atrial appendage, tricuspid and mitral valves, modulator band, and parts of the left atrium. The third separate proteome corresponded to the inner walls of the left and right ventricles, septum, and left atrial appendage. Differential protein abundancies indicated differences in energy metabolism between regions. Data analyses of the mitochondrial proteins revealed a variable pattern of abundances of complexes I-V between the proteomes, indicating differences in the bioenergetics of the different cardiac sub-proteomes. Mapping of disease-associated proteins interestingly showed desmoglein-2, for which defects in this protein are known to cause Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, which was present predominantly in the outer wall of the left ventricle. This study highlights that organs can have variable proteomes that do not necessarily correspond to anatomical features.

Altered Inflammatory State and Mitochondrial Function Identified by Transcriptomics in Paediatric Congenital Heart Patients Prior to Surgical Repair.

Congenital heart disease (CHD) remains the most common birth defect, with surgical intervention required in complex cases. Right ventricle (RV) function is known to be a major predictor of sustained cardiac health in these patients; thus, by elucidating the divergent profiles between CHD and the control through tissue analysis, this study aims to identify new avenues of investigation into the mechanisms surrounding reduced RV function. Transcriptomic profiling, in-silico deconvolution and functional network analysis were conducted on RV biopsies, identifying an increase in the mitochondrial dysfunction genes RPPH1 and RMPR (padj = 4.67 × 10-132, 2.23 × 10-107), the cytotoxic T-cell markers CD8a, LAGE3 and CD49a (p = 0.0006, p < 0.0001, and p = 0.0118) and proinflammatory caspase-1 (p = 0.0055) in CHD. Gene-set enrichment identified mitochondrial dysfunctional pathways, predominately changes within oxidative phosphorylation processes. The negative regulation of mitochondrial functions and metabolism was identified in the network analysis, with dysregulation of the mitochondrial complex formation. A histological analysis confirmed an increase in cellular bodies in the CHD RV tissue and positive staining for both CD45 and CD8, which was absent in the control. The deconvolution of bulk RNAseq data suggests a reduction in CD4+ T cells (p = 0.0067) and an increase in CD8+ T cells (p = 0.0223). The network analysis identified positive regulation of the immune system and cytokine signalling clusters in the inflammation functional network, as there were lymphocyte activation and leukocyte differentiation. Utilising RV tissue from paediatric patients undergoing CHD cardiac surgery, this study identifies dysfunctional mitochondrial pathways and an increase in inflammatory T-cell presence prior to reparative surgery.

Biallelic PKP2 loss of function variants are associated with a lethal perinatal-onset biventricular dilated cardiomyopathy with excessive trabeculations and ventricular septal defects.

Homozygous plakophilin-2 (PKP2) variants have been identified as a cause of a lethal form of dilated cardiomyopathy with excessive trabeculations (DCM-ET) in three cases. We report three more cases from two families with homozygous pathogenic PKP2 variants and perinatal-onset, lethal DCM-ET. Identification of the genetic abnormalities played a key role in decision-making and family counselling in these cases. This case series supports the published evidence that biallelic loss of function PKP2 variants cause a lethal, perinatal-onset cardiomyopathy.

Surgical-PEARL protocol: a multicentre prospective cohort study exploring aetiology, management and outcomes for patients with congenital anomalies potentially requiring surgical intervention.

INTRODUCTION: Congenital anomalies affect over 2% of pregnancies. Surgical advances have reduced mortality and improved survival for patients with congenital anomalies potentially requiring surgical (CAPRS) intervention. However, our understanding of aetiology, diagnostic methods, optimal management, outcomes and prognostication is limited. Existing birth cohorts have low numbers of individual heterogenous CAPRS. The Surgical Paediatric congEnital Anomalies Registry with Long term follow-up (Surgical-PEARL) study aims to establish a multicentre prospective fetal, child and biological parent cohort of CAPRS. METHODS AND ANALYSIS: From 2022 to 2027, Surgical-PEARL aims to recruit 2500 patients with CAPRS alongside their biological mothers and fathers from up to 15 UK centres. Recruitment will be antenatal or postnatal dependent on diagnosis timing and presentation to a recruitment site. Routine clinical data including antenatal scans and records, neonatal intensive care unit (NICU) records, diagnostic and surgical data and hospital episode statistics will be collected. A detailed biobank of samples will include: parents' blood and urine samples; amniotic fluid if available; children's blood and urine samples on admission to NICU, perioperatively or if the child has care withdrawn or is transferred for extracorporeal membrane oxygenation; stool samples; and surplus surgical tissue. Parents will complete questionnaires including sociodemographic and health data. Follow-up outcome and questionnaire data will be collected for 5 years. Once established we will explore the potential of comparing findings in Surgical-PEARL to general population cohorts born in the same years and centres. ETHICS AND DISSEMINATION: Ethical and health research authority approvals have been granted (IRAS Project ID: 302251; REC reference number 22/SS/0004). Surgical-PEARL is adopted onto the National Institute for Health Research Clinical Research Network portfolio. Findings will be disseminated widely through peer-reviewed publication, conference presentations and through patient organisations and newsletters. TRIAL REGISTRATION NUMBER: ISRCTN12557586.

Myxoid variant epithelioid pleural mesothelioma defines a favourable prognosis group: an analysis of 191 patients with pleural malignant mesothelioma.

Malignant pleural mesothelioma shows marked cytoarchitectural diversity. The aim of the study was to evaluate how morphological phenotype impacted upon overall survival. 191 cases of malignant pleural mesothelioma with available follow-up were identified, examined and classified according to histological types. The epithelioid mesotheliomas were further subdivided according to morphological subtypes: myxoid, microcystic, tubulopapillary, solid epithelioid, micropapillary and pleomorphic; biphasic mesotheliomas were divided into epithelioid component dominant and sarcomatoid component dominant; pure sarcomatoid mesotheliomas were divided into not otherwise specified, leiomyoid, desmoplastic and heterologous. All cases were confirmed by two experienced observers. Myxoid variant malignant pleural epithelioid mesothelioma was observed to have a favourable overall survival compared with pleomorphic form (p=0.00008). Pleomorphic phenotype had the worst overall survival. Morphological phenotype is an important histological factor that should be included in pathology reports to convey potential favourable prognostic subgroups of patients with mesothelioma.

Social and behavioural factors in Non-suspicious unexpected death in infancy; experience from metropolitan police project indigo investigation.

BACKGROUND: Risk factors for Sudden Unexpected Death in Infancy (SUDI) are well described, and such cases are now investigated according to standard protocols. In London, Project Indigo of the Metropolitan Police provides a unique, detailed framework for such data collection. We investigate such data to provide a contemporary account of SUDI in a large city and further link data to publically available datasets to investigate interactions with social factors. METHODS: Retrospective analysis of data routinely collected by the Metropolitan Police Service in all cases of non-suspicious SUDI deaths in London during a six year period. RESULTS: SUDI deaths are associated with markers of social deprivation in London. A significant proportion of such deaths are associated with potentially modifiable risk factors such as cigarette smoking and co-sleeping, such behaviour also being associated with social factors, including accommodation issues. CONCLUSIONS: Routinely collected data provide valuable insight into patterns and associations of mortality, with SUDI remaining a significant issue in London. Risk factors include social disadvantage, which may manifest in part by affecting behavioural patterns such as co-sleeping and public health interventions to reduce rates require significant social modification.

A case of gallstone-induced small bowel necrosis masquerading as clinical appendicitis.

Cholecysto-duodenal fistula and gallstone ileus are well-recognised complications of gallstone disease. However, small bowel necrosis is a rare complication of gallstone disease. We describe a case of gallstone-induced ileal necrosis presenting with symptoms and signs resembling acute appendicitis. A 79-year-old woman presented to the surgical team with central abdominal pain which subsequently shifted to the right iliac fossa. Clinically, the patient had localised perotinism in the right iliac fossa with high inflammatory markers. Abdominal radiography showed no diagnostic features. Initial clinical impression was that of acute appendicitis. Given that this diagnosis was unlikely in a patient of this age, an abdominal CT scan was performed. The CT scan showed evidence of a large gallstone causing small bowel obstruction in the presence of a cholecysto-duodenal fistula. At surgery, she was found to have an area of necrosis with a pin-point perforation at the site of impaction of the gallstone in the proximal ileum. This occurred secondarily to pressure necrosis from the gallstone impacting at a site where the small bowel diameter narrows in transition from jejunum to ileum. A limited small bowel resection was performed with an uncomplicated postoperative course. This case report draws attention to a rare complication of gallstone disease which presents with a clinical picture similar to acute appendicitis. Preoperative investigation for an elderly patient who presents with an acute abdomen should include an abdominal CT scan to diagnose any rare disease processes which otherwise may not be suspected.