Inhibition of phosphodiesterase10A attenuates morphine-induced conditioned place preference

Background Phosphodiesterase (PDE) 10A is selectively expressed in medium spiny neurons of the striatum. Nucleus accumbens (NAc) is a key region that mediates drug reward and addiction-related behaviors. To investigate the potential role of PDE10A in the reinforcement properties of morphine, we tested the effect of MP-10, a selective inhibitor of PDE10A, on acquisition, expression, and extinction of morphine-induced conditioned place preference (CPP). Results The results show that 2.5 mg/kg MP-10, administered subcutaneously, significantly inhibited the acquisition of morphine-induced CPP. The same dose of MP-10 alone did not result in the CPP. Moreover, MP-10 did not alter the expression of morphine-induced CPP, but did accelerate the extinction of morphine-induced CPP. Additionally, chronic treatment with 2.5 mg/kg MP-10 decreased expression of phosphorylated CREB (pCREB), activated cAMP response element binding protein, in dorsomedial striatum, in shell of NAc, and in anterior cingulate cortex (ACC) as well as decreased expression of ΔFosB in the shell of NAc and ACC. Conclusion The results suggest that inhibition of PDE10A may have therapeutic potential in the treatment of opioid addiction

Inhibition of phosphodiesterase10A attenuates morphine-induced conditioned place preference

Background: Phosphodiesterase (PDE) 10A is selectively expressed in medium spiny neurons of the striatum. Nucleus accumbens (NAc) is a key region that mediates drug reward and addiction-related behaviors. To investigate the potential role of PDE10A in the reinforcement properties of morphine, we tested the effect of MP-10, a selective inhibitor of PDE10A, on acquisition, expression, and extinction of morphine-induced conditioned place preference (CPP). Results: The results show that 2.5 mg/kg MP-10, administered subcutaneously, significantly inhibited the acquisition of morphine-induced CPP. The same dose of MP-10 alone did not result in the CPP. Moreover, MP-10 did not alter the expression of morphine-induced CPP, but did accelerate the extinction of morphine-induced CPP. Additionally, chronic treatment with 2.5 mg/kg MP-10 decreased expression of phosphorylated CREB (pCREB), activated cAMP response element binding protein, in dorsomedial striatum, in shell of NAc, and in anterior cingulate cortex (ACC) as well as decreased expression of ΔFosB in the shell of NAc and ACC. Conclusion: The results suggest that inhibition of PDE10A may have therapeutic potential in the treatment of opioid addiction

Discovery of Novel Inhibitors Targeting the Macrophage Migration Inhibitory Factor via Structure-Based Virtual Screening and Bioassays

Macrophage migration inhibitory factor (MIF) is involved in regulation of both the innate and the adaptive immune responses and is regarded as an attractive anti-inflammatory pharmacological target. In this study, molecular docking-based virtual screening and in vitro bioassays were utilized to identify novel small-molecule inhibitors of MIF. The in vitro enzyme-based assay identified that ten chemically diverse compounds exhibited potent inhibitory activity against MIF in the micromolar regime, including three compounds with IC₅₀ values below 10 μM and one with an IC₅₀ value below 1 μM (0.55 μM); the latter is 26-fold more potent than the reference compound ISO-1. The structural analysis demonstrates that most of these active compounds possess novel structural scaffolds. Further in vitro cell-based glucocorticoid overriding, chemotaxis, and Western blotting assays revealed that the three compounds can effectively inhibit the biological functions of MIF in vitro, suggesting that these compounds could be potential agents for treating inflammatory diseases

Hypoxia-inducible factor upregulation by roxadustat attenuates drug reward by altering brain iron homoeostasis

Abstract Substance use disorder remains a major challenge, with an enduring need to identify and evaluate new, translational targets for effective treatment. Here, we report the upregulation of Hypoxia-inducible factor-1α (HIF-1α) expression by roxadustat (Rox), a drug developed for renal anemia that inhibits HIF prolyl hydroxylase to prevent degradation of HIF-1α, administered either systemically or locally into selected brain regions, suppressed morphine (Mor)-induced conditioned place preference (CPP). A similar effect was observed with methamphetamine (METH). Moreover, Rox also inhibited the expression of both established and reinstated Mor-CPP and promoted the extinction of Mor-CPP. Additionally, the elevation of HIF-1α enhanced hepcidin/ferroportin 1 (FPN1)-mediated iron efflux and resulted in cellular iron deficiency, which led to the functional accumulation of the dopamine transporter (DAT) in plasma membranes due to iron deficiency-impaired ubiquitin degradation. Notably, iron-deficient mice generated via a low iron diet mimicked the effect of Rox on the prevention of Mor- or METH-CPP formation, without affecting other types of memory. These data reveal a novel mechanism for HIF-1α and iron involvement in substance use disorder, which may represent a potential novel therapeutic strategy for the treatment of drug abuse. The findings also repurpose Rox by suggesting a potential new indication for the treatment of substance use disorder

Hypoxia-inducible factor upregulation by roxadustat attenuates drug reward by altering brain iron homoeostasis

Substance use disorder remains a major challenge, with an enduring need to identify and evaluate new, translational targets for effective treatment. Here, we report the upregulation of Hypoxia-inducible factor-1α (HIF-1α) expression by roxadustat (Rox), a drug developed for renal anemia that inhibits HIF prolyl hydroxylase to prevent degradation of HIF-1α, administered either systemically or locally into selected brain regions, suppressed morphine (Mor)-induced conditioned place preference (CPP). A similar effect was observed with methamphetamine (METH). Moreover, Rox also inhibited the expression of both established and reinstated Mor-CPP and promoted the extinction of Mor-CPP. Additionally, the elevation of HIF-1α enhanced hepcidin/ferroportin 1 (FPN1)-mediated iron efflux and resulted in cellular iron deficiency, which led to the functional accumulation of the dopamine transporter (DAT) in plasma membranes due to iron deficiency-impaired ubiquitin degradation. Notably, iron-deficient mice generated via a low iron diet mimicked the effect of Rox on the prevention of Mor- or METH-CPP formation, without affecting other types of memory. These data reveal a novel mechanism for HIF-1α and iron involvement in substance use disorder, which may represent a potential novel therapeutic strategy for the treatment of drug abuse. The findings also repurpose Rox by suggesting a potential new indication for the treatment of substance use disorder. </p

Structure–Activity Relationships and Anti-inflammatory Activities of <i>N</i>‑Carbamothioylformamide Analogues as MIF Tautomerase Inhibitors

Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is an attractive therapeutic target for the treatment of inflammatory diseases. In our previous study, 3-[(biphenyl-4-ylcarbonyl)­carbamothioyl]­amino benzoic acid (compound <b>1</b>) was discovered as a potent inhibitor of MIF by docking-based virtual screening and bioassays. Here, a series of analogues of compound <b>1</b> derived from similarity search and chemical synthesis were evaluated for their MIF tautomerase activities, and their structure–activity relationships were then analyzed. The most potent inhibitor (compound <b>5</b>) with an IC₅₀ of 370 nM strongly suppressed lipopolysaccharide (LPS)-induced production of TNF-α and IL-6 in a dose-dependent manner and significantly enhanced the survival rate of mice with LPS-induced endotoxic shock from 0 to 35% at 0.5 mg/kg and to 45% at 1 mg/kg, highlighting the therapeutic potential of the MIF tautomerase inhibition in inflammatory diseases

Hypoxia-inducible factor upregulation by roxadustat attenuates drug reward by altering brain iron homoeostasis

Substance use disorder remains a major challenge, with an enduring need to identify and evaluate new, translational targets for effective treatment. Here, we report the upregulation of Hypoxia-inducible factor-1α (HIF-1α) expression by roxadustat (Rox), a drug developed for renal anemia that inhibits HIF prolyl hydroxylase to prevent degradation of HIF-1α, administered either systemically or locally into selected brain regions, suppressed morphine (Mor)-induced conditioned place preference (CPP). A similar effect was observed with methamphetamine (METH). Moreover, Rox also inhibited the expression of both established and reinstated Mor-CPP and promoted the extinction of Mor-CPP. Additionally, the elevation of HIF-1α enhanced hepcidin/ferroportin 1 (FPN1)-mediated iron efflux and resulted in cellular iron deficiency, which led to the functional accumulation of the dopamine transporter (DAT) in plasma membranes due to iron deficiency-impaired ubiquitin degradation. Notably, iron-deficient mice generated via a low iron diet mimicked the effect of Rox on the prevention of Mor- or METH-CPP formation, without affecting other types of memory. These data reveal a novel mechanism for HIF-1α and iron involvement in substance use disorder, which may represent a potential novel therapeutic strategy for the treatment of drug abuse. The findings also repurpose Rox by suggesting a potential new indication for the treatment of substance use disorder. </p