G protein Inactivation as a Mechanism for Addiction Treatment.

The endogenous dynorphin/kappa opioid receptor (KOR) system in the brain mediates the dysphoric effects of stress, and KOR antagonists may have therapeutic potential for the treatment of drug addiction, depression, and psychosis. One class of KOR antagonists, the long-acting norBNI-like antagonists, have been suggested to act by causing KOR inactivation through a cJun-kinase mechanism rather than by competitive inhibition. In this study, we screened for other opioid ligands that might produce norBNI-like KOR inactivation and found that nalfurafine (a G-biased KOR agonist) and nalmefene (a KOR partial agonist) also produce long-lasting KOR inactivation.

Ultra-fast genetically encoded sensor for precise real-time monitoring of physiological and pathophysiological peroxide dynamics.

Hydrogen Peroxide (HO) is a central oxidant in redox biology due to its pleiotropic role in physiology and pathology. However, real-time monitoring of HO in living cells and tissues remains a challenge. We address this gap with the development of an optogenetic hydRogen perOxide Sensor (oROS), leveraging the bacterial peroxide binding domain OxyR.

Structure-guided engineering of a fast genetically encoded sensor for real-time HO monitoring.

Hydrogen Peroxide (HO) is a central oxidant in redox biology due to its pleiotropic role in physiology and pathology. However, real-time monitoring of HO in living cells and tissues remains a challenge. We address this gap with the development of an optogenetic hydRogen perOxide Sensor (oROS), leveraging the bacterial peroxide binding domain OxyR.

Kappa Opioid Receptors in Mesolimbic Terminals Mediate Escalation of Cocaine Consumption.

Increases in drug consumption over time, also known as escalation, is a key behavioral component of substance use disorder (SUD) that is related to potential harm to users, such as overdose. Studying escalation also allows researchers to investigate the transition from casual drug use to more SUD-like drug use. Understanding the neurobiological systems that drive this transition will inform therapeutic treatments in the aim to prevent increases in drug use and the development of SUD.

Optogenetic stimulation of dynorphinergic neurons within the dorsal raphe activate kappa opioid receptors in the ventral tegmental area and ablation of dorsal raphe prodynorphin or kappa receptors in dopamine neurons blocks stress potentiation of cocaine reward.

Behavioral stress exposure increases the risk of drug-taking in individuals with substance use disorders by mechanisms involving the dynorphins, which are the endogenous neuropeptides for the kappa opioid receptor (KOR). KOR agonists have been shown to encode dysphoria, aversion, and changes in reward valuation, and kappa opioid antagonists are in clinical development for treating substance use disorders. In this study, we confirmed that KORs were expressed in dopaminergic neurons in the ventral tegmental area (VTA) of male C57BL6/J mice.