Chronic pain has been widely recognized as a major public health problem that impacts multiple aspects of patient quality of life. Unfortunately, chronic pain is often resistant to conventional analgesics, which are further limited by their various side effects. New therapeutic strategies and targets are needed to better serve the millions of people suffering from this devastating disease. To this end, recent clinical and preclinical studies have implicated the epidermal growth factor receptor signaling pathway in chronic pain states. EGFR is one of four members of the ErbB family of receptor tyrosine kinases that have key roles in development and the progression of many cancers. EGFR functions by activating many intracellular signaling pathways following binding of various ligands to the receptor. Several of these signaling pathways, such as phosphatidylinositol 3-kinase, are known mediators of pain. EGFR inhibitors are known for their use as cancer therapeutics but given recent evidence in pilot clinical and preclinical investigations, may have clinical use for treating chronic pain. Here, we review the clinical and preclinical evidence implicating EGFR in pathological pain states and provide an overview of EGFR signaling highlighting how EGFR and its ligands drive pain hypersensitivity and interact with important pain pathways such as the opioid system.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is the causative agent of COVID19 that has infected >76M people and caused >1.68M deaths. The SARS-CoV2 Spike glycoprotein is responsible for the attachment and infection of target cells. The viral Spike protein serves the basis for many putative therapeutic countermeasures including vaccines, blocking and neutralizing antibodies, and decoy receptors. Here we investigated the cytosolic domain of Spike and its interaction with the protein palmitoyltransferase ZDHHC5. The Spike protein is palmitoylated on multiple juxtamembrane cysteine residues conserved among coronavirus. Increased abundance of ZDHHC5 resulted in hyper-palmitoylation, while silencing of ZDHHC5 reduced the ability of the human CoV 229E to form viral plaques in cell monolayers. Inhibition of fatty acid synthase using the pharmacological inhibitor TVB-3166 eliminated palmitoylation of SARS-CoV2 Spike. Additionally, TVB-3166 attenuated plaque formation and promoted the survival of mice from a lethal murine CoV infection. Thus, inhibition of the Spike protein palmitoylation has the potential to treat SARS-CoV-2 and other CoV infections.

Phagocytosis is a receptor-mediated process used by cells to engulf a wide variety of particulates, including microorganisms and apoptotic cells. Many of the proteins involved in this highly orchestrated process are post-translationally modified with lipids as a means of regulating signal transduction, membrane remodeling, phagosome maturation and other immunomodulatory functions of phagocytes. S-acylation, generally referred to as S-palmitoylation, is the post-translational attachment of fatty acids to a cysteine residue exposed topologically to the cytosol. This modification is reversible due to the intrinsically labile thioester bond between the lipid and sulfur atom of cysteine, and thus lends itself to a variety of regulatory scenarios. Here we present an overview of a growing number of S-acylated proteins known to regulate phagocytosis and phagosome biology in macrophages.