Xue-jun Xu

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AIM to investigate the effects of ATPM-ET [(-)-3-N-Ethylaminothiazolo [5,4-b]-N-cyclopropylmethylmorphinan hydrochloride] on physical dependence and behavioral sensitization to morphine in mice. METHODS the pharmacological profile of ATPM-ET was characterized using competitive binding and GTPγS binding assays. We then examined the antinociceptive effects(More)
The opioid receptors are a member of G protein-coupled receptors that mediate physiological effects of endogenous opioid peptides and structurally distinct opioid alkaloids. Although it is well characterized that there is differential receptor desensitization and internalization properties following activation by distinct agonists, the underlying mechanisms(More)
Internalization and recycling of G protein-coupled receptors (GPCRs), such as the mu-opioid receptor, largely depend on agonist stimulation. Agonist-promoted internalization of some GPCRs has been shown to mediate receptor desensitization, resensitization, and down-regulation. In this study, we investigated whether different mu opioid agonists displayed(More)
Analgesics such as morphine cause many side effects including addiction, but kappa-opioid receptor agonist can produce antinociception without morphine-like side effects. With the aim of developing new and potent analgesics with lower abuse potential, we studied the antinociceptive and physical dependent properties of a derivate of ICI-199441, an analogue(More)
ATPM [(-)-3-amino-thiazolo[5,4-b]-N-cyclopropylmethylmorphinan hydrochloride] was found to have mixed kappa- and mu-opioid activity and identified to act as a full kappa-agonist and a partial mu-agonist by in vitro binding assays. The present study was undertaken to characterize its in vivo effects on morphine antinociceptive tolerance in mice and heroin(More)
Distinct opioid receptor agonists have been proved to induce differential patterns of ERK activation, but the underlying mechanisms remain unclear. Here, we report that Ser363 in the δ-opioid receptor (δOR) determines the different abilities of the δOR agonists DPDPE and TIPP to activate ERK by G-protein- or β-arrestin-dependent pathways. Although both(More)
The effect of a naphthalimide pharmacophore coupled with diverse substituents on the interaction between naphthalimide-polyamine conjugates 1-4 and bovine serum albumin (BSA) was studied by UV absorption, fluorescence and circular dichroism (CD) spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of BSA by the compounds(More)
AIM To define the effect of adenosine A(1) receptor (A(1)R) on delta opioid receptor (DOR)-mediated signal transduction. METHODS CHO cells stably expressing HA-tagged A(1)R and DOR-CFP fusion protein were used. The localization of receptors was observed using confocal microscope. DOR-mediated inhibition of adenylyl cyclase was measured using cyclic AMP(More)
To develop novel analgesics with no side effects or less side effects than traditional opioids is highly demanded to treat opioid receptor mediated pain and addiction issues. Recently, κ-opioid receptor (KOR) has been established as an attractive target, although its selective agonists could bear heterogeneous pharmacological activities. In this study, we(More)
Hepatic stellate cells (HSCs) induce immune privilege and promote hepatocellular carcinoma (HCC) by suppressing the immune system. On the other hand, galectin-1 and miRNA-22 (miR-22) are dysregulated in HCC and serve as prognostic indicators for patients. In this study, therefore, we measured galectin-1 and miR-22 expression in HSCs isolated from HCC(More)