COVID-19 Therapeutics and Vaccines: A Race to Save Lives.

COVID-19 (Coronavirus Disease 2019), the disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) is an ongoing global public health emergency. As understanding of the health effects of COVID-19 has improved, companies and agencies worldwide have worked together to identify therapeutic approaches, fast-track clinical trials and pathways for emergency use, and approve therapies for patients. This work has resulted in therapies that not only improve survival, reduce time of hospitalization, and time to recovery, but also include preventative measures, such as vaccines. This manuscript discusses development programs for 3 products that are approved or authorized for emergency use at the time of writing: VEKLURY (remdesivir, direct-acting antiviral from Gilead Sciences, Inc.), REGEN-COV (casirivimab and imdevimab antibody cocktail from Regeneron Pharmaceuticals Inc.), and Comirnaty (Pfizer-BioNTech COVID-19 Vaccine [Pfizer, Inc.-BioNTech]), and perspectives from the U.S. Food and Drug Administration.

High-Throughput Patch Clamp Screening in Human α6-Containing Nicotinic Acetylcholine Receptors.

Nicotine, the addictive component of tobacco products, is an agonist at nicotinic acetylcholine receptors (nAChRs) in the brain. The subtypes of nAChR are defined by their α- and ß-subunit composition. The α6ß2ß3 nAChR subtype is expressed in terminals of dopaminergic neurons that project to the nucleus accumbens and striatum and modulate dopamine release in brain regions involved in nicotine addiction. Although subtype-dependent selectivity of nicotine is well documented, subtype-selective profiles of other tobacco product constituents are largely unknown and could be essential for understanding the addiction-related neurological effects of tobacco products. We describe the development and validation of a recombinant cell line expressing human α6/3ß2ß3V273S nAChR for screening and profiling assays in an automated patch clamp platform (IonWorks Barracuda). The cell line was pharmacologically characterized by subtype-selective and nonselective reference agonists, pore blockers, and competitive antagonists. Agonist and antagonist effects detected by the automated patch clamp approach were comparable to those obtained by conventional electrophysiological assays. A pilot screen of a library of Food and Drug Administration-approved drugs identified compounds, previously not known to modulate nAChRs, which selectively inhibited the α6/3ß2ß3V273S subtype. These assays provide new tools for screening and subtype-selective profiling of compounds that act at α6ß2ß3 nicotinic receptors.

TRPA1 is a polyunsaturated fatty acid sensor in mammals.

Fatty acids can act as important signaling molecules regulating diverse physiological processes. Our understanding, however, of fatty acid signaling mechanisms and receptor targets remains incomplete. Here we show that Transient Receptor Potential Ankyrin 1 (TRPA1), a cation channel expressed in sensory neurons and gut tissues, functions as a sensor of polyunsaturated fatty acids (PUFAs) in vitro and in vivo. PUFAs, containing at least 18 carbon atoms and three unsaturated bonds, activate TRPA1 to excite primary sensory neurons and enteroendocrine cells. Moreover, behavioral aversion to PUFAs is absent in TRPA1-null mice. Further, sustained or repeated agonism with PUFAs leads to TRPA1 desensitization. PUFAs activate TRPA1 non-covalently and independently of known ligand binding domains located in the N-terminus and 5(th) transmembrane region. PUFA sensitivity is restricted to mammalian (rodent and human) TRPA1 channels, as the drosophila and zebrafish TRPA1 orthologs do not respond to DHA. We propose that PUFA-sensing by mammalian TRPA1 may regulate pain and gastrointestinal functions.

TRPV1-null mice are protected from diet-induced obesity.

We explored a role for the capsaicin receptor, transient receptor potential channel vanilloid type 1 (TRPV1), in the regulation of feeding and body mass. On a 4.5% fat diet, wild-type and TRPV1-null mice gained equivalent body mass. On an 11% fat diet, however, TRPV1-null mice gained significantly less mass and adiposity; at 44 weeks the mean body weights of wild-type and TRPV1-null mice were approximately 51 and 34g, respectively. Both groups of mice consumed equivalent energy and absorbed similar amounts of lipids. TRPV1-null mice, however, exhibited a significantly greater thermogenic capacity. Interestingly, we found that 3T3-L1 preadipocytes expressed functional calcitonin gene-related peptide receptors. Thus, these data support a potential neurogenic mechanism by which TRPV1-sensitive sensory nerves may regulate energy and fat metabolism.