N-Acetylcysteine and Other Sulfur-Donors as a Preventative and Adjunct Therapy for COVID-19

Figure 1

Schematic presentation of the epithelial glycocalyx (GL) in mammalian cells, forming a mesh-like structure that projects into the extracellular matrix (ECM). The proteoglycan presented is a syndecan with heparan sulfate and chondroitin sulfate glycosaminoglycan (GAG) side chains. The sulfate groups (SO₄²⁻) are indicated in red dots, attached to the GAG and glycoprotein side chains. Hyaluronic acid is unsulfated and anchored to the receptor CD44 on the cell membrane. The glycoprotein consists of a protein base with carbohydrate chains (orange circles) extending into the extracellular space with sialic acid (orange square) bound at the terminal position of the oligosaccharide chains. Soluble proteoglycans and free GAG chains can appear in the extracellular space.