COVID-19: The Potential Treatment of Pulmonary Fibrosis Associated with SARS-CoV-2 Infection

Post COVID-19 fibrosis, an emerging complicationof SARS-CoV-2 infection

SARS-COV-2 has created one of the most massive pandemics in modern history. There is a rapid accumulation of data on its epidemiology, clinical course, diagnosis, management, and complications. One of the sequelae of COVID-19 pneumonia and acute respiratory distress syndrome (ARDS) is pulmonary fibrosis. There is a dearth of accurate data on the prevalence of pulmonary fibrosis post-COVID-19. We report a patient who developed dyspnea secondary to pulmonary fibrosis after successful treatment of COVID-19 pneumonia.

A Network-Based Analysis Reveals the Mechanism Underlying Vitamin D in Suppressing Cytokine Storm and Virus in SARS-CoV-2 Infection

Background

SARS-CoV-2 causes ongoing pandemic coronavirus disease of 2019 (COVID-19), infects the cells of the lower respiratory tract that leads to a cytokine storm in a significant number of patients resulting in severe pneumonia, shortness of breathing, respiratory and organ failure. Extensive studies suggested the role of Vitamin D in suppressing cytokine storm in COVID-19 and reducing viral infection; however, the precise molecular mechanism is not clearly known. In this work, bioinformatics and systems biology approaches were used to understand SARS-CoV-2 induced cytokine pathways and the potential mechanism of Vitamin D in suppressing cytokine storm and enhancing antiviral response.

Results

This study used transcriptome data and identified 108 differentially expressed host genes (DEHGs) in SARS-CoV-2 infected normal human bronchial epithelial (NHBE) cells compared to control. Then, the DEHGs was integrated with the human protein-protein interaction data to generate a SARS-CoV-2 induced host gene regulatory network (SiHgrn). Analysis of SiHgrn identified a sub-network "Cluster 1" with the highest MCODE score, 31 up-regulated genes, and predominantly associated immune and inflammatory response. Interestingly, the iRegulone tool identified that "Cluster 1" is under the regulation of transcription factors STAT1, STAT2, STAT3, POU2F2, and NFkB1, collectively referred to as "host response signature network". Functional enrichment analysis with NDEx revealed that the "host response signature network" is predominantly associated with critical pathways, including "cytokines and inflammatory response", "non-genomic action of Vitamin D", "the human immune response to tuberculosis", and "lung fibrosis". Finally, in-depth analysis and literature mining revealed that Vitamin D binds with its receptor and could work through two different pathways: (i) it inhibits the expression of pro-inflammatory cytokines through blocking the TNF induced NFkB1 signaling pathway; and (ii) it initiates the expression of interferon-stimulating genes (ISGs) for antiviral defense program through activating the IFN-α induced Jak-STAT signaling pathway.

Conclusion

This comprehensive study identified the pathways associated with cytokine storm in SARS-CoV-2 infection. The proposed underlying mechanism of Vitamin D could be promising in suppressing the cytokine storm and inducing a robust antiviral response in severe COVID-19 patients. The finding in this study urgently needs further experimental validations for the suitability of Vitamin D in combination with IFN-α to control severe COVID-19.

FDA approved drugs with pharmacotherapeutic potential for SARS-CoV-2 (COVID-19) therapy

In December 2019, a novel SARS-CoV-2 coronavirus emerged, causing an outbreak of life-threatening pneumonia in the Hubei province, China, and has now spread worldwide, causing a pandemic. The urgent need to control the disease, combined with the lack of specific and effective treatment modalities, call for the use of FDA-approved agents that have shown efficacy against similar pathogens. Chloroquine, remdesivir, lopinavir/ritonavir or ribavirin have all been successful in inhibiting SARS-CoV-2 in vitro. The initial results of a number of clinical trials involving various protocols of administration of chloroquine or hydroxychloroquine mostly point towards their beneficial effect. However, they may not be effective in cases with persistently high viremia, while results on ivermectin (another antiparasitic agent) are not yet available. Interestingly, azithromycin, a macrolide antibiotic in combination with hydroxychloroquine, might yield clinical benefit as an adjunctive. The results of clinical trials point to the potential clinical efficacy of antivirals, especially remdesivir (GS-5734), lopinavir/ritonavir, and favipiravir. Other therapeutic options that are being explored involve meplazumab, tocilizumab, and interferon type 1. We discuss a number of other drugs that are currently in clinical trials, whose results are not yet available, and in various instances we enrich such efficacy analysis by invoking historic data on the treatment of SARS, MERS, influenza, or in vitro studies. Meanwhile, scientists worldwide are seeking to discover novel drugs that take advantage of the molecular structure of the virus, its intracellular life cycle that probably elucidates unfolded-protein response, as well as its mechanism of surface binding and cell invasion, like angiotensin converting enzymes-, HR1, and metalloproteinase inhibitors.

Covid-19 hyperinflammation and post-Covid-19 illness may be rooted in mast cell activation syndrome

OBJECTIVES

One-fifth of Covid-19 patients suffer a severe course of Covid-19 infection; however, the specific causes remain unclear. Mast cells (MCs) are activated by SARS-CoV-2. Although only recently recognized, MC activation syndrome (MCAS), usually due to acquired MC clonality, is a chronic multisystem disorder with inflammatory and allergic themes, and an estimated prevalence of 17%. This paper describes a novel conjecture explaining how MCAS might cause a propensity for severe acute Covid-19 infection and chronic post-Covid-19 illnesses.

METHODS

Observations of Covid-19 illness in patients with/without MCAS were compared with extensive clinical experience with MCAS.

RESULTS

The prevalence of MCAS is similar to that of severe cases within the Covid-19-infected population. Much of Covid-19's hyperinflammation is concordant with manners of inflammation which MC activation can drive. Drugs with activity against MCs or their mediators have preliminarily been observed to be helpful in Covid-19 patients. None of the authors' treated MCAS patients with Covid-19 suffered severe infection, let alone mortality.

CONCLUSIONS

Hyperinflammatory cytokine storms in many severely symptomatic Covid-19 patients may be rooted in an atypical response to SARS-CoV-2 by the dysfunctional MCs of MCAS rather than a normal response by normal MCs. If proven, this theory has significant therapeutic and prognostic implications.

A Dangerous Consequence of the Recent Pandemic: Early Lung Fibrosis Following COVID-19 Pneumonia - Case Reports

The outbreak of the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) started in China in December 2019. COVID-19 patients at presentation show a wide spectrum of clinical and pathological involvement. We report two cases of respiratory insufficiency due to COVID-19 pneumonia that occurred in adults without a history of respiratory diseases. Although these patients improved and were discharged from the acute ward, during the hospitalization they both progressed with a subsequent clinical and radiological worsening, pointing out one of the main concerns for these patients at discharge: the possibility of developing persistent lung abnormalities also in healthy people not having other risk factors. In conclusion, these cases represent two examples of early lung fibrosis in patients with COVID-19 pneumonia with different severity disease evolution and highlight the need for long-term follow-up strategies. The etiology of this fibrosis is under discussion: we suppose that it could be due to either a possible outcome of natural history of lung damage produced by ARDS, or to the lung injury related to high oxygen level or to the lung damage directly induced by viral infection or finally to the autoimmune response. At this moment, it is not possible to predict how many people will have consequences due to COVID-19 pneumonia, and therefore we believe that careful follow-up should be mandatory.

The NRF2-LOC344887 signaling axis suppresses pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible disease characterized by an increase in differentiation of fibroblasts to myofibroblasts and excessive accumulation of extracellular matrix in lung tissue. Pharmacological activation of NRF2 has proved to be a valuable antifibrotic approach, however the detailed mechanisms of how NRF2 mediates antifibrotic function remain unclear. In this study, we found that the antifibrotic function of sulforaphane (SFN), an NRF2 activator, was largely dependent on LOC344887, a long noncoding RNA. Two functional AREs were identified in both the promoter and intron 1 of LOC344887, which defines LOC344887 as a novel anti-fibrotic NRF2 target gene. RNA-seq analysis revealed that LOC344887 controls genes and signaling pathways associated with fibrogenesis. Deletion or downregulation of LOC344887 enhanced expression of CDH2/N-cadherin, as well as a number of other fibrotic genes and blunted the antifibrotic effects of SFN. Furthermore, LOC344887-mediated downregulation of fibrotic genes may involve the PI3K-AKT signaling pathway, as pharmacologic inhibition of PI3K activity blocked the effects of LOC344887 knockdown. Our findings demonstrate that NRF2-mediated LOC344887 upregulation contributes to the antifibrotic potential of SFN by repressing the expression of CDH2 and other fibrotic genes, providing novel insight into how NRF2 controls the regulatory networks of IPF. This study provides a better understanding of the molecular mechanisms of NRF2 activators against pulmonary fibrosis and presents a novel therapeutic axis for prevention and intervention of fibrosis-related diseases.

[Combination therapy at an early stage of the novel coronavirus infection (COVID-19). Case series and design of the clinical trial "BromhexIne and Spironolactone for CoronаvirUs Infection requiring hospiTalization (BISCUIT)"]

The article focuses on effective treatment of the novel coronavirus infection (COVID-19) at early stages and substantiates the requirement for antiviral therapy and for decreasing the viral load to prevent the infection progression. The absence of a specific antiviral therapy for the SARS-CoV-2 virus is stated. The authors analyzed results of early randomized studies using lopinavir/ritonavir, remdesivir, and favipiravir in COVID-19 and their potential for the treatment of novel coronavirus infection. Among the drugs blocking the virus entry into cells, the greatest attention was paid to the antimalaria drugs, chloroquine and hydroxychloroquine. The article addresses in detail ineffectiveness and potential danger of hydroxychloroquine, which demonstrated neither a decrease in the time of clinical recovery nor any improvement of prognosis for patients with COVID-19. The major objective was substantiating a possible use of bromhexine, a mucolytic and anticough drug, which can inhibit transmembrane serin protease 2 required for entry of the SARS-CoV-2 virus into cells. Spironolactone may have a similar feature. Due to its antiandrogenic effects, spironolactone can inhibit X-chromosome-related synthesis of ACE-2 receptors and activation of transmembrane serin protease 2. In addition to slowing the virus entry into cells, spironolactone decreases severity of fibrosis in different organs, including the lungs. The major part of the article addresses clinical examples of managing patients with COVID-19 at the University Clinic of the Medical Research and Educational Centre of the M. V. Lomonosov Moscow State University, including successful treatment with schemes containing bromhexine and spironolactone. In conclusion, the authors described the design of a randomized, prospective BISCUIT study performed at the University Clinic of the M. V. Lomonosov Moscow State University with an objective of evaluating the efficacy of this scheme.

COVID-19 Pneumonia: Three Thoracic Complications in the Same Patient

The most dreaded thoracic complications in patients with coronavirus disease 2019 (COVID-19) are acute pulmonary embolism and pulmonary fibrosis. Both the complications are associated with an increased risk of morbidity and mortality. While acute pulmonary embolism is not a rare finding in patients with COVID-19 pneumonia, the prevalence of pulmonary fibrosis remains unclear. Spontaneous pneumothorax is another possible complication in COVID-19 pneumonia, although its observation is rather uncommon. Herein, we present interesting computed tomography images of the first case of COVID-19 pneumonia that initially developed acute pulmonary embolism and subsequently showed progression toward pulmonary fibrosis and spontaneous pneumothorax.