Structure-activity relationships of thiadiazole agonists of the human secretin receptor.

Agonists of the secretin receptor have potential applications for diseases of the cardiovascular, gastrointestinal, and metabolic systems, yet no clinically-active non-peptidyl agonists of this receptor have yet been developed. In the current work, we have identified a new small molecule lead compound with this pharmacological profile. We have prepared and characterized a systematic structure-activity series around this thiadiazole scaffold to better understand the molecular determinants of its activity. We were able to enhance the in vitro activity and to maintain the specificity of the parent compound. We found the most active candidate to be quite stable in plasma, although it was metabolized by hepatic microsomes. This chemical probe should be useful for in vitro studies and needs to be tested for in vivo pharmacological activity. This could be an important lead toward the development of a first-in-class orally active agonist of the secretin receptor, which could be useful for multiple disease states.

STING-Activating Small Molecular Therapeutics for Cancer Immunotherapy.

Immuno-oncology has become a revolutionary strategy for cancer treatment. Therapeutic interventions based on adaptive immunity through immune checkpoint therapy or chimeric antigen receptor T cells have received clinical approval for monotherapy and combination treatment use in various cancers. Although these treatments have achieved clinical successes, only a minority of cancer patients show a response, highlighting the urgent need to discover new therapeutic molecules that could be exploited to improve clinical outcomes and pave the way for the next generation of immunotherapy. Given the critical role of the innate immune system against infection and cancer, substantial efforts have been dedicated to developing novel anticancer therapeutics that target these pathways. Targeting the stimulator of interferon genes (STING) pathway is a powerful strategy to generate durable antitumor response, and activation of the adaptor protein STING induces the initiation of transcriptional cascades, thereby producing type I interferons, pro-inflammatory cytokines and chemokines. Various STING agonists, including natural or synthetic cyclic dinucleotides (CDNs) have been developed as anticancer therapeutics. However, since most CDNs are confined to intratumoral administration, there has been a great interest in developing non-nucleotide agonists for systemic treatment. Here we review the current development of STING-activating therapeutics in both preclinical or clinical stages.

Next-generation neuropeptide Y receptor small-molecule agonists inhibit mosquito-biting behavior.

BACKGROUND: Female Aedes aegypti mosquitoes can spread disease-causing pathogens when they bite humans to obtain blood nutrients required for egg production. Following a complete blood meal, host-seeking is suppressed until eggs are laid. Neuropeptide Y-like receptor 7 (NPYLR7) plays a role in endogenous host-seeking suppression and previous work identified small-molecule NPYLR7 agonists that inhibit host-seeking and blood-feeding when fed to mosquitoes at high micromolar doses. METHODS: Using structure-activity relationship analysis and structure-guided design we synthesized 128 compounds with similarity to known NPYLR7 agonists. RESULTS: Although in vitro potency (EC50) was not strictly predictive of in vivo effect, we identified three compounds that reduced blood-feeding from a live host when fed to mosquitoes at a dose of 1 µM-a 100-fold improvement over the original reference compound. CONCLUSIONS: Exogenous activation of NPYLR7 represents an innovative vector control strategy to block mosquito biting behavior and prevent mosquito-human host interactions that lead to pathogen transmission.