Long COVID-19 and the heart: is cardiac mitochondria the missing link?

SIGNIFICANCE: Although COVID-19 has now gradually been categorized as an endemic, the long-term effect of COVID-19 in causing multi-organ disorders, including a perturbed cardiovascular system, is beginning to gain attention. Nonetheless, the underlying mechanism triggering post-COVID-19 cardiovascular dysfunction remains enigmatic. Are cardiac mitochondria the key to mediating cardiac dysfunction post-SARS-CoV-2 infection? RECENT ADVANCES: Cardiovascular complications post-SARS-CoV-2 infection include myocarditis, myocardial injury, microvascular injury, pericarditis, acute coronary syndrome, and arrhythmias (fast or slow). Different types of myocardial damage or reduced heart function can occur after a lung infection or lung injury. Myocardial/coronary injury or decreased cardiac function is directly associated with increased mortality after hospital discharge in patients with COVID-19. The incidence of adverse cardiovascular events increases even in recovered COVID-19 patients. Disrupted cardiac mitochondria post-infection have been postulated to lead to cardiovascular dysfunction in the COVID-19 patients. Further studies are crucial to unravel the association between SARS-CoV-2 infection, mitochondrial dysfunction and ensuing cardiovascular disorders. CRITICAL ISSUES: The relationship between COVID-19 and myocardial injury or cardiovascular dysfunction has not been elucidated. In particular, the role of the cardiac mitochondria in this association remains to be determined. FUTURE DIRECTIONS: Elucidating the cause of cardiac mitochondrial dysfunction post-SARS-CoV-2 infection may allow a deeper understanding of long COVID-19 and resulting cardiovascular disorders, thus providing a potential therapeutic target.

Detection of Viral RNA Fragments in Human iPSC-Cardiomyocytes following Treatment with Extracellular Vesicles from SARS-CoV-2 Coding-Sequence-Overexpressing Lung Epithelial Cells

The novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a worldwide pandemic. Early data suggest that the prevalence and severity of COVID-19 appear to be higher among patients with underlying cardiovascular risk factors. Despite the expression of angiotensin-converting enzyme 2 (ACE2), a functional receptor for SARS-CoV-2 infection, in cardiomyocytes, there has been no conclusive evidence of direct viral infection although the presence of inflammation and viral genome within the hearts of COVID-19 patients have been reported. Here we transduced A549 lung epithelial cells with lentivirus overexpressing selected genes of the SARS-CoV-2. We then isolated extracellular vesicles (EVs) from the supernatant of A549 cells and detected the presence of viral RNA within the purified EVs. Importantly, we observed that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were able to actively uptake these EVs and viral genes were subsequently detected in the cardiomyocytes. Accordingly, uptake of EVs containing viral genes led to an upregulation of inflammation-related genes in hiPSC-CMs. Thus, our findings indicate that SARS-CoV-2 RNA-containing EVs represent an indirect route of viral RNA entry into cardiomyocytes.

Detection of viral RNA fragments in human iPSC cardiomyocytes following treatment with extracellular vesicles from SARS-CoV-2 coding sequence overexpressing lung epithelial cells.

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global pandemic. The prevalence/severity of COVID-19 is higher among patients with cardiovascular risk factors. Despite the expression of angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 infection, in cardiomyocytes, there has been no conclusive evidence of direct viral infection although the presence of viral genome within COVID-19 patients' hearts has been reported. Here, we overexpressed SARS-CoV-2 genes in A549 lung epithelial cells. We then isolated extracellular vesicles (EVs) and detected the presence of viral RNA within these EVs. We observed that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are receptive to these EVs, and viral genes were detectable in the cardiomyocytes. Accordingly, the uptake of viral RNA-harboring EVs led to an upregulation of inflammation-related genes in hiPSC-CMs. Thus, our findings indicate that SARS-CoV-2 RNA containing EVs represents an indirect route of viral RNA entry into cardiomyocytes.

Detection of Viral RNA Fragments in Human iPSC-Cardiomyocytes following Treatment with Extracellular Vesicles from SARS-CoV-2 Coding-Sequence-Overexpressing Lung Epithelial Cells.

The novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a worldwide pandemic. Early data suggest that the prevalence and severity of COVID-19 appear to be higher among patients with underlying cardiovascular risk factors. Despite the expression of angiotensin-converting enzyme 2 (ACE2), a functional receptor for SARS-CoV-2 infection, in cardiomyocytes, there has been no conclusive evidence of direct viral infection although the presence of inflammation and viral genome within the hearts of COVID-19 patients have been reported. Here we transduced A549 lung epithelial cells with lentivirus overexpressing selected genes of the SARS-CoV-2. We then isolated extracellular vesicles (EVs) from the supernatant of A549 cells and detected the presence of viral RNA within the purified EVs. Importantly, we observed that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were able to actively uptake these EVs and viral genes were subsequently detected in the cardiomyocytes. Accordingly, uptake of EVs containing viral genes led to an upregulation of inflammation-related genes in hiPSC-CMs. Thus, our findings indicate that SARS-CoV-2 RNA-containing EVs represent an indirect route of viral RNA entry into cardiomyocytes.