Ligands Regulate Cell Surface Level of the Human κ Opioid Receptor by Activation-Induced Down-Regulation and Pharmacological Chaperone-Mediated Enhancement: Differential Effects of Nonpeptide and Peptide Agonists

Chen, Yong; Chen, Chongguang; Wang, Yulin; Liu-Chen, Lee Yuan

doi:10.1124/jpet.106.107987

Cited by 41 publications

(35 citation statements)

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“…rKOR up-regulation was associated with a decrease in the level of the 42-kDa precursor and a concomitant increase in the mature 52-kDa receptor, and the increase in immunoreactivity occurred in parallel with the increase in B max . The 3-to 4-fold up-regulation observed herein was significantly greater than the maximal 30% up-regulation of the human KOR induced by naloxone (Chen et al, 2006). The reason for the discrepant magnitudes of up-regulation may be due to species differences or to the use of different cell lines to express the receptors.…”

Section: Discussionmentioning

confidence: 52%

“…1B). After incubation of the cells for 6 h with BFA alone (at a concentration slightly lower than that used previously by Petaja-Repo et al, 2002 andChen et al, 2006), the pattern of rKOR immunoreactivity was altered. After BFA treatment, the predominant receptor species in rKOR cells was a diffuse band with an apparent molecular mass of approximately 44 kDa, and a faint 48-kDa form was also present (Fig.…”

Section: Ligand-induced Up-regulation Of the -Opioid Receptor 617mentioning

confidence: 96%

“…This species-dependent difference is remarkable given that the human and rat KORs are identical in 94% of amino acid positions. Chen et al (2006) reported that alkaloid agonists (with the exception of etorphine) caused a modest reduction (15-30%) in the level of the mature 55-kDa human KOR, whereas etorphine, pentazocine, naloxone, norbinaltorphimine, and naloxonazine increased the level by 10 to 30%. 6.…”

Section: Discussionmentioning

confidence: 99%

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A Select Set of Opioid Ligands Induce Up-Regulation by Promoting the Maturation and Stability of the Rat κ-Opioid Receptor in Human Embryonic Kidney 293 Cells

Wannemacher

Yadav²,

Howells³

2007

J Pharmacol Exp Ther

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Ligand-induced regulation of the rat -opioid receptor (rKOR) was investigated in human embryonic kidney 293 cells stably expressing the FLAG-tagged rKOR. Incubation of rKOR cells with naltrexone for 24 h increased the B max Ͼ3-fold, with no change in the affinity of [ 3 H]diprenorphine. Two immunoreactive receptor species were present in cell lysates: naltrexone treatment caused a Ͼ3-fold increase in the 52-kDa species while decreasing the level of the 42-kDa species. Dynorphin(1-13), U69,593]pyran-7-carboxylic acid methyl ester] treatment did not alter the level of immunoreactive rKOR protein, whereas etorphine, cyclazocine, naloxone, and naloxone methiodide increased the 52-kDa and decreased the 42-kDa rKOR bands. Receptor up-regulation was associated with an increase in the number of cell surface receptors and a 2-fold increase in the E max for guanosine 5Ј-O-(3-[ 35 S]thio)triphosphate binding. Glycosidase digestion indicated that the 52-and 42-kDa receptors contained complex and high-mannose N-glycans, respectively, Pulse-chase analysis and glycosidase digestion sensitivities suggested that the 42-kDa rKOR species was a precursor of the 52-kDa species. Naltrexone did not alter rKOR mRNA levels or translational efficiency, and rKOR up-regulation was not inhibited by cycloheximide. Brefeldin A caused accumulation of intracellular rKOR intermediates, and coincubation with naltrexone increased the levels of the brefeldin-induced species significantly. These results suggest that select opioid ligands upregulate rKOR by enhancing the rate of receptor folding and maturation and by protecting the receptor from degradation, resulting in an increase in the number of rKOR binding sites, immunoreactive protein, and functional receptors.Chronic administration of morphine or other opioid agonists for pain relief results in tolerance to the analgesic effects and physical dependence (McQuay, 1999). In contrast, chronic blockade of opioid receptors with antagonists such as naloxone and naltrexone does not result in physical dependence and was shown nearly 30 years ago to be associated with supersensitivity to the analgesic actions of morphine (Tang and Collins, 1978). The enhanced analgesic effects of morphine following infusion of naloxone were correlated with an increase in the number of opioid receptor binding sites (Lahti and Collins, 1978). Antagonist-mediated opioid receptor up-regulation has been shown to occur in vivo for -opioid receptors (MORs), ␦-opioid receptors, and -opioid receptors (KORs) (Morris et al., 1988;Lesscher et al., 2003), highlighting its biological relevance; however, the underlying mechanisms remain unclear. The steady-state level of opioid receptor mRNAs did not change in response to chronic in vivo antagonist treatment; therefore, post-transcriptional mechanisms are apparently involved (for review, see Unterwald and Howells, 2008).A large number of human diseases, for example cystic fibrosis, are due to genetic mutations that cause protein misfolding (Thomas et al

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Section: Discussionmentioning

confidence: 52%

Section: Ligand-induced Up-regulation Of the -Opioid Receptor 617mentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

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A Select Set of Opioid Ligands Induce Up-Regulation by Promoting the Maturation and Stability of the Rat κ-Opioid Receptor in Human Embryonic Kidney 293 Cells

Wannemacher

Yadav²,

Howells³

2007

J Pharmacol Exp Ther

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“…We have shown previously that non-peptide κ full agonists have different efficacies in regulating the hKOR. While U50,488H causes robust phosphorylation, internalization and down-regulation, etorphine does not (Chen et al, 2006b;Li et al, 2000;Li et al, 1999;Li et al, 2003). In the present study, using CHO cells stably expressing the hKOR as the model system, we found that three major dynorphins, Dyn A, Dyn B and α-Neo, induced differential regulation of the hKOR after receptor activation.…”

Section: Introductionmentioning

confidence: 50%

“…We have previously demonstrated that non-peptide agonists down-regulated cell surface FLAG-hKOR to less extents than peptide agonists (Chen et al, 2006b). In addition to causing agonist-induced receptor degradation, non-peptide agonists function intracellularly as pharmacological chaperones to enhance cell surface receptor expression.…”

Section: Agonist-dependent Receptor Adaptation Following Activationmentioning

confidence: 99%

Dynorphin peptides differentially regulate the human κ opioid receptor

Chen

Liu‐Chen

2007

Life Sciences

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Dynorphins, endogenous peptides for the κ opioid receptor, play important roles in many physiological and pathological functions. Here, we examined how prolonged treatment with three major prodynorphin peptides, dynorphin A (1-17) (Dyn A), dynorphin B (1-13) (Dyn B) and α-neoendorphin (α-Neo), regulated the human kappa opioid receptor (hKOR) stably expressed in Chinese hamster ovary (CHO) cells. Results from receptor binding and [ 35 S]GTPγS binding assays showed that these peptides were potent full agonists of the hKOR with comparable receptor reserve and intrinsic efficacy to stimulate G proteins. A 4-h incubation with α-Neo at a concentration of ∼600× EC 50 value (from [ 35 S]GTPγS binding) resulted in receptor down-regulation to a much lower extent than the incubation with Dyn A and Dyn B at comparable concentrations (∼10% vs. ∼65%). Extending incubation period and increasing concentrations did not significantly affect the difference. The plateau level of α-Neo-mediated receptor internalization (30 min) was significantly less than those of Dyn A and Dyn B. Omission of serum from the incubation medium or addition of peptidase inhibitors into the serum-containing medium enhanced α-Neo-, but not Dyn A-or Dyn B-, mediated receptor down-regulation and internalization; however, the degrees of α-Neo-induced adaptations were still significantly less than those of Dyn A and Dyn B. Thus, these endogenous peptides differentially regulate KOR after activating the receptor with similar receptor occupancy and intrinsic efficacy. Both stability in the presence of serum and intrinsic capacity to promote receptor adaptation play roles in the observed discrepancy among the dynorphin peptides.

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Association of In Vivo κ-Opioid Receptor Availability and the Transdiagnostic Dimensional Expression of Trauma-Related Psychopathology

et al. 2014

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IMPORTANCE Exposure to trauma increases the risk for developing threat (ie, fear) symptoms, such as reexperiencing and hyperarousal symptoms, and loss (ie, dysphoria) symptoms, such as emotional numbing and depressive symptoms. While preclinical data have implicated the activated dynorphin/κ-opioid receptor (KOR) system in relation to these symptoms, the role of the KOR system in mediating these phenotypes in humans is unknown. Elucidation of molecular targets implicated in threat and loss symptoms is important because it can help inform the development of novel, mechanism-based treatments for trauma-related psychopathology.OBJECTIVE To use the newly developed [ 11 C]LY2795050 radiotracer and high-resolution positron emission tomography to evaluate the relation between in vivo KOR availability in an amygdala-anterior cingulate cortex-ventral striatal neural circuit and the severity of threat and loss symptoms. We additionally evaluated the role of 24-hour urinary cortisol levels in mediating this association. DESIGN, SETTING, AND PARTICIPANTSThis cross-sectional positron emission tomography study under resting conditions was conducted at an academic medical center. Thirty-five individuals representing a broad transdiagnostic and dimensional spectrum of trauma-related psychopathology, ranging from nontrauma-exposed psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology (ie, posttraumatic stress disorder, major depressive disorder, and/or generalized anxiety disorder).MAIN OUTCOMES AND MEASURES [ 11 C]LY2795050 volume of distribution values in amygdala-anterior cingulate cortex-ventral striatal neural circuit; composite measures of threat (ie, reexperiencing, avoidance, and hyperarousal symptoms) and loss (ie, emotional numbing, major depressive disorder, and generalized anxiety disorder symptoms) symptoms as assessed using the Clinician-Administered PTSD Scale, Hamilton Depression Rating Scale, and Hamilton Rating Scale for Anxiety; and 24-hour urinary cortisol levels.RESULTS [ 11 C]LY2795050 volume of distribution values in an amygdala-anterior cingulate cortex-ventral striatal neural circuit were negatively associated with severity of loss (r = −0.39; 95% CI, −0.08 to −0.66), but not threat (r = −0.03; 95% CI, −0.30 to 0.27), symptoms; this association was most pronounced for dysphoria symptoms (r = −0.45; 95% CI, −0.10 to −0.70). Path analysis revealed that lower [ 11 C]LY2795050 volume of distribution values in this circuit was directly associated with greater severity of loss symptoms and indirectly mediated by 24-hour urinary cortisol levels. CONCLUSIONS AND RELEVANCEResults of this study suggest that KOR availability in an amygdala-anterior cingulate cortex-ventral striatal neural circuit mediates the phenotypic expression of trauma-related loss (ie, dysphoria) symptoms. They further suggest that an activated corticotropin-releasing factor/hypothalamic-pituitary-adrenal axis system, as assessed by 24-hour urinary cortisol levels, may indirectly mediate this associ...

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Ligands Regulate Cell Surface Level of the Human κ Opioid Receptor by Activation-Induced Down-Regulation and Pharmacological Chaperone-Mediated Enhancement: Differential Effects of Nonpeptide and Peptide Agonists

Cited by 41 publications

References 44 publications

A Select Set of Opioid Ligands Induce Up-Regulation by Promoting the Maturation and Stability of the Rat κ-Opioid Receptor in Human Embryonic Kidney 293 Cells

A Select Set of Opioid Ligands Induce Up-Regulation by Promoting the Maturation and Stability of the Rat κ-Opioid Receptor in Human Embryonic Kidney 293 Cells

Dynorphin peptides differentially regulate the human κ opioid receptor

Association of In Vivo κ-Opioid Receptor Availability and the Transdiagnostic Dimensional Expression of Trauma-Related Psychopathology

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