cytokine receptor

Dexamethasone is a glucocorticoid receptor agonist and IL receptor modulator with anti-inflammatory, immunosuppressive, and apoptosis-inducing activities. It inhibits the production of inflammatory miRNA-155 exosomes in macrophages, significantly reduces inflammatory cytokine expression in neutrophils and monocytes, suppresses LPS-induced macrophage inflammation, and induces autophagy. It is commonly used to induce animal models of depression, muscle atrophy, and hypertension, and holds potential in COVID-19 research.

Lipopolysaccharides (LPS), derived from Escherichia coli O55:B5, are essential components of the outer membrane of Gram-negative bacteria. Composed of lipid A, a core oligosaccharide, and an O-specific polysaccharide, LPS exhibits strong immunogenicity. It activates immune cells via the TLR4 receptor, induces chemotactic cell migration and cytokine secretion, and helps maintain the integrity of the bacterial outer membrane, protecting against bile salts and lipid-based antibiotics. LPS is commonly used to establish inflammatory models, including arthritis, chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), and gastrointestinal disease models.

Resiquimod (R848) is an agonist of Toll-like receptors 7 and 8 (TLR7/TLR8) that induces the upregulation of cytokines including TNF-α, IL-6, and IFN-α. It possesses immunomodulatory, antitumor, and antiviral activities, and can be used to induce models of myocarditis and systemic lupus erythematosus (SLE).