Incidence of acute myocardial injury and its association with left and right ventricular systolic dysfunction in critically ill COVID-19 patients.

BACKGROUND: Previous studies have found an increase in cardiac troponins (cTns) and echocardiographic abnormalities in patients with COVID-19 and reported their association with poor clinical outcomes. Whether acute injury occurs during the course of critical care and if it is associated with cardiac function is unknown. The purpose of this study was to document the incidence of acute myocardial injury (AMInj) and echocardiographically defined left ventricular (LV) and right ventricular (RV) systolic dysfunction in consecutive patients admitted to an intensive care unit (ICU) for COVID-19. The relationship between AMInj and echocardiographic abnormalities during the first 14 days of ICU admission was studied. Finally, the association between echocardiographic findings, AMInj and clinical outcome was evaluated. METHODS: Seventy-four consecutive patients (≥18 years) admitted to the ICU at Linköping University Hospital between 19 Mar 2020 and 31 Dec 2020 for COVID-19 were included. High-sensitivity troponin-T (hsTnT) was measured daily for up to 14 days. Transthoracic echocardiography was conducted within 72 h of ICU admission. Acute myocardial injury was defined as an increased hsTnT > 14ng/l and a > 20% absolute change with or without ischaemic symptoms. LV and RV systolic dysfunction was defined as at least 2 abnormal indicators of systolic function specified by consensus guidelines. RESULTS: Increased hsTnT was observed in 59% of patients at ICU admission, and 82% developed AMInj with peak levels at 8 (3-13) days after ICU admission. AMInj was not statistically significantly associated with 30-day mortality but was associated with an increased duration of invasive mechanical ventilation (10 (3-13) vs. 5 days (0-9), p=0.001) as well as ICU length of stay (LOS) (19.5 (11-28) vs. 7 days (5-13), p=0.015). After adjustment for SAPS-3 and admission SOFA score, the effect of AMInj was significant only for the duration of mechanical ventilation (p=0.030). The incidence of LV and RV dysfunction was 28% and 22%, respectively. Only indices of LV and RV longitudinal contractility (mitral and tricuspid annular plane systolic excursion) were associated with AMInj. Echocardiographic parameters were not associated with clinical outcome. CONCLUSIONS: Myocardial injury is common in critically ill patients with COVID-19, with AMInj developing in more than 80% after ICU admission. In contrast, LV and RV dysfunction occurred in approximately one-quarter of patients. AMInj was associated with an increased need for mechanical ventilation and ICU LOS but neither AMInj nor ventricular dysfunction was significantly associated with mortality.

The transcriptosomal response of human A549 lung cells to a hydrogen peroxide-generating system: relationship to DNA damage, cell cycle arrest, and caspase activation.

Intracellular oxidative stress is a dynamic situation characterized by the accumulation of reactive oxygen metabolites, such as hydrogen peroxide. This is traditionally associated with both macromolecular damage and adaptive changes in gene expression, aimed at preventing cellular demise. However, the overall extent of such genetic changes is not well characterized. Here we present a comprehensive analysis of altered mRNA profiles in human A549 type II lung epithelial cells in response to hydrogen peroxide, at concentrations failing to induce necrotic toxicity. The results of an Affymetrix-based screen of the steady-state levels of mRNAs for several thousand genes revealed a complex pattern of transcriptional and/or posttranscriptional response to oxidative stress, which can be functionally related to both the oxidation and repair of damaged DNA, the induction and permanency of cell cycle arrest, and caspase-3 activation. Many of the genetic events can be related to activation of the p53/p21 pathway, but many other novel inductions and suppressions were detected, revealing the intricacy of the response. The data also disclosed a potential interaction between hydrogen peroxide treatment and increased sensitivity to cell killing by TRAIL, which could be functionally confirmed at the level of induction of caspase-3 activity.

Gene and protein expression profiling of human cerebral endothelial cells activated with tumor necrosis factor-alpha.

An increase in permeability of the blood-brain barrier is a critical event in the pathophysiological process of multiple sclerosis and other neurodegenerative diseases. Tumor necrosis factor alpha (TNFalpha) is known to play a crucial role in this process and is a powerful activator of endothelial cell inflammatory responses. Although many reports describe effects of TNFalpha activation in endothelial cells, the molecular mechanisms specific for activation of cerebral endothelial cells remains unclear. The objective of this study was to identify potential pharmaceutical targets for the treatment of multiple sclerosis using molecular profiling techniques. Gene expression measurements (Affymetrix Hu6800 oligonucleotide arrays) and proteomics (two-dimensional gel electrophoresis and mass spectrometry) were applied to analyze early alterations in human cerebral endothelial cells (HCEC) activated by TNFalpha. Human umbilical vein endothelial cells (HUVEC) were used as the reference system. The results presented show that HCEC and HUVEC respond similarly with respect to cell adhesion molecules, chemotaxis, apoptosis and oxidative stress molecules. However, nuclear factors NFkB1 and NFkB2, plasminogen activator inhibitor 1 and cofilin 1 are examples of cerebral specific responses. Our results indicate involvements of the urokinase plasminogen activator system and cytoskeletal rearrangements unique to TNFalpha activation of cerebral endothelial cells.