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Novel SARS-CoV-2 variants induce higher toxicity in cardiovascular cells. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Objective
SARS-CoV-2 causes the coronavirus disease 2019 (COVID-19) and has spawned a global health crisis. Virus infection can lead to elevated markers of cardiac injury and inflammation associated with a higher risk of mortality. However, it is so far unclear whether cardiovascular damage is caused by direct virus infection or is mainly secondary due to inflammation. Recently, additional novel SARS-CoV-2 variants have emerged accounting for more than 70% of all cases in Germany. To what extend these variants differ from the original strain in their pathology remains to be elucidated.
Here, we investigated the effect of the novel SARS-CoV-2 variants on cardiovascular cells.
Results
To study whether cardiovascular cells are permissive for SARS-CoV-2, we inoculated human iPS-derived cardiomyocytes and endothelial cells from five different origins, including umbilical vein endothelial cells, coronary artery endothelial cells (HCAEC), cardiac and lung microvascular endothelial cells, or pulmonary arterial cells, in vitro with SARS-CoV-2 isolates (G614 (original strain), B.1.1.7 (British variant), B.1.351 (South African variant) and P.1 (Brazilian variant)).
While the original virus strain infected iPS-cardiomyocytes and induced cell toxicity 96h post infection (290±10 cells vs. 130±10 cells; p=0.00045), preliminary data suggest a more severe infection by the novel variants. To what extend the response to the novel variants differ from the original strain is currently investigated by phosphoproteom analysis.
Of the five endothelial cells studied, only human coronary artery EC took up the original virus strain, without showing viral replication and cell toxicity. Spike protein was only detected in the perinuclear region and was co-localized with calnexin-positive endosomes, which was accompanied by elevated ER-stress marker genes, such as EDEM1 (1.5±0.2-fold change; p=0.04). Infection with the novel SARS-CoV-2 variants resulted in significant higher levels of viral spike compared to the current strain. Surprisingly, viral up-take was also seen in other endothelial cell types (e.g. HUVEC). Although no viral replication was observed (850±158 viral RNA copies at day 0 vs. 197±43 viral RNA copies at day 3; p=0.01), the British SARS-CoV-2 variant B.1.1.7 reduced endothelial cell numbers (0.63±0.03-fold change; p=0.0001).
Conclusion
Endothelial cells and cardiomyocytes showed a distinct response to SARS-CoV-2. Whereas cardiomyocytes were permissively infected, endothelial cells took up the virus, but were resistant to viral replication. However, both cell types showed signs of increased toxicity induced by the British SARS-CoV-2 variant. These data suggest that cardiac complications observed in COVID-19 patients might at least in part be based on direct infection of cardiovascular cells. The more severe cytotoxic effects of the novel variants implicate that patients infected with the new variants should be even more closely monitored.
Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): DFG and Willy-Pitzer Foundation
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Epigenetic regulation of oxidative and inflammatory phenotypes in women with gestational diabetes and offspring. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Hyperglycemia-induced oxidative stress and inflammation are potent drivers of atherosclerotic cardiovascular disease (ASCVD). Gestational diabetes (GDM) is characterized by chronic hyperglycemia during pregnancy and may represent a clinical model to study the mechanisms of oxidative stress and inflammation induced by hyperglycemia. GDM is associated with a range of adverse perinatal and long-term outcomes for both mother and offspring. In this perspective, it is emerging a putative association between maternal GDM and offspring's epigenetic trait.
Purpose
To investigate the link between histone modifications, oxidative stress and inflammatory phenotype as well as the transmission of epigenetic signatures to the offspring.
Methods
We analyzed peripheral blood mononuclear cells (PBMC) from GDM and control mothers as well as human umbilical vein endothelial cells (HUVEC) and cord blood mononuclear cells (CBMC) isolated from newborn umbilical cords obtained at delivery from both groups. Histone methyltransferase MLL1-dependent trimethylation of histone 3 at lysine 4 amino residue (H3K4me3) on NF-kB p65 subunit promoter region was assessed by chromatin immunoprecipitation (ChIP) and real-time qPCR in HUVEC, PBMC and CBMC, respectively. MLL1 and downstream inflammatory and redox genes were determined by real-time qPCR and immunocytochemistry in the presence and in the absence of MLL1 inhibitor MM-102. Measurement of reactive oxygen species (ROS) was performed by electron spin resonance spectroscopy.
Results
For the first time, we demonstrated a significant increase of MLL1 expression with subsequent MLL1-induced upregulation of NF-kB p65 gene via H3K4me3 in GDM as compared to control cells. MLL1-driven epigenetic remodeling of NF-kB p65 promoter is upstream to the activation of inflammatory pathway. Indeed, treatment with MM-102 decreased H3K4me3 and blunted expression of NF-kB p65 as well as VCAM-1, MCP-1 and IL-6 genes. We also found that expression of ROS scavenger aldehyde dehydrogenase 2 is reduced, whereas pro-oxidant nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit NOX4 is upregulated. Interestingly, the increased ROS generation observed in GDM is involved in the upregulation of MLL1 as shown by the restoring effect of antioxidant vitamin C on MLL1 expression levels.
Conclusions
Our results suggest that a complex interplay between oxidative stress and histone modifications are responsible for the GDM maternal inflammatory and oxidative phenotypes and its transmission to the offspring. The deciphering of epigenetic-induced chromatin remodelling opens the perspective for pharmacological reprogramming of adverse chromatin changes to reduce the burden of early development of metabolic phenotypes and ASCVD.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): University G. d'Annunzio MIUR fundings Schematic figure
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