"The possible implication of endothelin in the pathology of COVID-19-induced pulmonary hypertension"

Perspectives on Post-COVID-19 Pulmonary Fibrosis Treatment

Pulmonary fibrosis, a critical outcome of chronic inflammatory diseases, has gained prominence in the context of post-coronavirus (post-COVID-19) complications. This review delves into the multifaceted landscape of post-COVID-19 pulmonary fibrosis, elucidating the intricate molecular mechanisms underlying its pathogenesis and highlighting promising therapeutic avenues. Examining the aftermath of severe acute respiratory syndrome-2 (SARS-CoV-2) infection, the review reveals key signaling pathways implicated in the fibrotic cascade. Drawing parallels with previous coronavirus outbreaks enhances our understanding of the distinctive features of post-COVID-19 fibrosis. Antifibrotic drugs, like pirfenidone and nintedanib, take center stage; their mechanisms of action and potential applications in post-COVID-19 cases are thoroughly explored. Beyond the established treatments, this review investigates emerging therapeutic modalities, including anti-interleukin agents, immunosuppressants, and experimental compounds, like buloxybutide, saracatinib, sirolimus, and resveratrol. Emphasizing the critical importance of early intervention, this review highlights the dynamic nature of post-COVID-19 pulmonary fibrosis research. In conclusion, the synthesis of current knowledge offers a foundation for advancing our approaches to the prevention and treatment of these consequential sequelae of COVID-19.

Endothelin-1 in Health and Disease

Discovered almost 40 years ago, the potent vasoconstrictor peptide endothelin-1 (ET-1) has a wide range of roles both physiologically and pathologically. In recent years, there has been a focus on the contribution of ET-1 to disease. This has led to the development of various ET receptor antagonists, some of which are approved for the treatment of pulmonary arterial hypertension, while clinical trials for other diseases have been numerous yet, for the most part, unsuccessful. However, given the vast physiological impact of ET-1, it is both surprising and disappointing that therapeutics targeting the ET-1 pathway remain limited. Strategies aimed at the pathways influencing the synthesis and release of ET-1 could provide new therapeutic avenues, yet research using cultured cells in vitro has had little follow up in intact ex vivo and in vivo preparations. This article summarises what is currently known about the synthesis, storage and release of ET-1 as well as the role of ET-1 in several diseases including cardiovascular diseases, COVID-19 and chronic pain. Unravelling the ET-1 pathway and identifying therapeutic targets has the potential to treat many diseases whether through disease prevention, slowing disease progression or reversing pathology.

Beyond Acute COVID-19: A Review of Long-term Cardiovascular Outcomes

Statistics Canada estimated that approximately 1.4 million Canadians suffer from long COVID. Although cardiovascular changes during acute SARS-CoV-2 infection are well documented, long-term cardiovascular sequelae are less understood. In this review, we sought to characterize adult cardiovascular outcomes in the months after acute COVID-19 illness. In our search we identified reports of outcomes including cardiac dysautonomia, myocarditis, ischemic injuries, and ventricular dysfunction. Even in patients without overt cardiac outcomes, subclinical changes have been observed. Cardiovascular sequelae after SARS-CoV-2 infection can stem from exacerbation of preexisting conditions, ongoing inflammation, or as a result of damage that occurred during acute infection. For example, myocardial fibrosis has been reported months after hospital admission for COVID-19 illness, and might be a consequence of myocarditis and myocardial injury during acute disease. In turn, myocardial fibrosis can contribute to further outcomes including dysrhythmias and heart failure. Severity of acute infection might be a risk factor for long-term cardiovascular consequences, however, cardiovascular changes have also been reported in young, healthy individuals who had asymptomatic or mild acute disease. Although evolving evidence suggests that previous SARS-CoV-2 infection might be a risk factor for cardiovascular disease, there is heterogeneity in existing evidence, and some studies are marred by measured and unmeasured confounders. Many investigations have also been limited by relatively short follow-up. Future studies should focus on longer term outcomes (beyond 1 year) and identifying the prevalence of outcomes in different populations on the basis of acute and long COVID disease severity.

Dantrolene and ryanodine receptors in COVID-19: The daunting task and neglected warden

Dantrolene (DTN) is a ryanodine receptor (RyR) antagonist that inhibits Ca²⁺ release from stores in the sarcoplasmic reticulum. DTN is mainly used in the management of malignant hyperthermia. RyRs are highly expressed in immune cells and are involved in different viral infections, including severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), because Ca²⁺ is necessary for viral replication, maturation and release. DTN can inhibit the proliferation of SARS-CoV-2, indicating its potential role in reducing entry and pathogenesis of SARS-CoV-2. DTN may increase clearance of SARS-CoV-2 and promote coronavirus disease 2019 (COVID-19) recovery by shortening the period of infection. DTN inhibits N-methyl-D-aspartate (NMDA) mediated platelets aggregations and thrombosis. Therefore, DTN may inhibit thrombosis and coagulopathy in COVID-19 through suppression of platelet NMDA receptors. Moreover, DTN has a neuroprotective effect against SARS-CoV-2 infection-induced brain injury through modulation of NMDA receptors, which are involved in excitotoxicity, neuronal injury and the development of neuropsychiatric disorders. In conclusion, DTN by inhibiting RyRs may attenuate inflammatory disorders in SARS-CoV-2 infection and associated cardio-pulmonary complications. Therefore, DNT could be a promising drug therapy against COVID-19. Preclinical and clinical studies are warranted in this regards.

ARTERIAL HYPERTENSION FOLLOWING COVID-19: A RETROSPECTIVE STUDY OF PATIENTS IN A CENTRAL EUROPEAN TERTIARY CARE CENTER

The aim of this study was to determine the frequency of newly verified or worsened existing hypertension in patients who had coronavirus 2019 (COVID-19). To be categorized as a COVID-19 patient, a positive reverse-transcription polymerase chain reaction test at a single point in time was required. The patients’ age, history, laboratory values and antihypertensive therapy of patients were recorded. In one year, 32 of 199 patients studied had either newly verified (15) or worsened existing (17) arterial hypertension. Among those patients, the median time from a verified infection to the onset of symptoms was 3 months. When the patients were divided into groups, 4 were in the acute, 11 in the sub-acute, 8 in the chronic and 9 in the “long COVID” group. Compared to the rest of the study population, patients presenting with arterial hypertension had significantly higher systolic (median 141 mmHg vs 130 mmHg, p<0.001) and diastolic (median 93 mmHg vs 80 mmHg, p<0.001) blood pressure and were significantly younger (median 51 vs 59 years, p 0.032). Arterial hypertension following COVID-19, either newly verified or worsened existing, is a relatively common occurrence (16% of our patient pool), indicating that more effort should be directed at evaluating the blood pressure values of patients following COVID-19.

Eosinopenia and increased markers of endothelial damage are characteristic of COVID-19 infection at time of hospital admission

In December 2019, a new virus has been discovered, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leading to coronavirus disease 2019 (COVID-19). COVID-19 has been defined as an evolving disease with different phases. It starts with a mild or asymptomatic phase in which there is minimal disease. Thereafter, most patients recover, however, in 20% of the cases the infection worsens. It is hypothesized that eosinopenia, endothelial injury and the presence of smooth muscle autoantibodies are associated with the severity of the COVID-19. In a subset of 75 blood samples of patients with a SARS-CoV-2 infection at time of hospitalization and 30 healthy control samples concentrations of eosinophils, VEGF, VCAM, endothelin and smooth muscle autoantibodies were determined with hemocytometry, ELISA and immunofluorescence assays. In the group of patients with COVID-19 eosinophils (IQR = 0.0-0.01*10⁹/L) were significantly decreased (p < .001), whereas markers of endothelial damage VCAM (IQR = 740-1120 ng/mL) and endothelin (IQR = 2.0-3.4 pg/mL) were significantly increased (p < .001) compared to the group of healthy controls (eosinophils IQR = 0.09-0.19*10⁹/L, VCAM IQR = 362-561 ng/mL, endothelin IQR = 0.5-1.0 pg/mL). From the multivariate analysis, it is concluded that at time of hospitalization a combination of eosinopenia and increased markers of endothelial damage VCAM and endothelin are characteristic of COVID-19.