Human Identical Sequences, hyaluronan, and hymecromone ─ the new mechanism and management of COVID-19

Clinically informative microRNAs for SARS-CoV-2 infection

COVID-19 is a viral respiratory infection induced by the newly discovered coronavirus SARS-CoV-2. miRNA is an example of a strong and direct regulator of a gene's transcriptional activity. The interaction between miRNAs and their target molecules is responsible for homeostasis. Virus-derived and host-derived miRNAs are involved in the activity of hiding from immune system cells, inducing the inflammatory reaction through interplay with associated genes, during SARS-COV-2 infection. Interest in miRNAs has raised the comprehension of the machinery and pathophysiology of SARS-COV-2 infection. In this review, the effects and biological roles of miRNAs on SARS-CoV-2 pathogenicity and life cycle are described. The therapeutic potential of miRNAs against SARS-CoV-2 infection are also mentioned.

Vascular Endothelial Glycocalyx Damage and Potential Targeted Therapy in COVID-19

COVID-19 is a highly infectious respiratory disease caused by a new coronavirus known as SARS-CoV-2. COVID-19 is characterized by progressive respiratory failure resulting from diffuse alveolar damage, inflammatory infiltrates, endotheliitis, and pulmonary and systemic coagulopathy forming obstructive microthrombi with multi-organ dysfunction, indicating that endothelial cells (ECs) play a central role in the pathogenesis of COVID-19. The glycocalyx is defined as a complex gel-like layer of glycosylated lipid–protein mixtures, which surrounds all living cells and acts as a buffer between the cell and the extracellular matrix. The endothelial glycocalyx layer (EGL) plays an important role in vascular homeostasis via regulating vascular permeability, cell adhesion, mechanosensing for hemodynamic shear stresses, and antithrombotic and anti-inflammatory functions. Here, we review the new findings that described EGL damage in ARDS, coagulopathy, and the multisystem inflammatory disease associated with COVID-19. Mechanistically, the inflammatory mediators, reactive oxygen species (ROS), matrix metalloproteases (MMPs), the glycocalyx fragments, and the viral proteins may contribute to endothelial glycocalyx damage in COVID-19. In addition, the potential therapeutic strategies targeting the EGL for the treatment of severe COVID-19 are summarized and discussed.