Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
Neuropharmacology. 2018 Jan;128:132-141. doi: 10.1016/j.neuropharm.2017.10.005. Epub 2017 Oct 4.
Amphetamine (AMPH)-mediated norepinephrine transporter (NET) downregulation requires NET-T258/S259 trafficking motif. The present study utilizes cell permeable NET-T258/S259 motif interfering peptide, which blocks AMPH-induced NET downregulation, to explore the role of this form of NET regulation in AMPH-mediated behaviors. In rats receiving intra-accumbal microinjections of TAT-conjugated peptides encompassing NET-T258/S259 motif, acute systemic AMPH failed to inhibit NE transport in the TAT-NET-T258/S259 wild-type (WT) peptide injected hemisphere but not in the vehicle or scrambled peptide injected hemisphere. Acute AMPH-induced hyperactivity was significantly reduced in rats receiving intra-accumbal TAT-NET-T258/S259 WT peptide compared to those receiving intra-accumbal vehicle or TAT-NET-T258A/S259A mutant peptide or corresponding TAT-conjugated scrambled peptide. Basal locomotor activity was not altered by peptide infusions alone. Similarly AMPH-induced locomotor sensitization was significantly reduced in rats receiving intra-accumbal TAT-NET-T258/S259 WT peptide prior to AMPH challenge and not in rats receiving the mutant or scrambled peptide. In conditioned place preference (CPP) paradigm, a single bilateral intra-accumbal microinjection of TAT-NET-T258/S259 WT peptide prior to CPP testing significantly reduced AMPH-induced CPP expression. Likewise, a single bilateral intra-accumbal microinjection of TAT-NET-T258/S259 WT peptide prior to drug-challenge significantly attenuated AMPH-primed CPP reinstatement. On the other hand, bilateral intra-accumbal microinjection of scrambled peptide did not affect AMPH-induced CPP expression or reinstatement. These data demonstrate a role for T258/S259-dependent NET regulation in AMPH-induced hyperactivity and sensitization as well as AMPH-induced CPP expression and reinstatement.
安非他命（AMPH）介导的去甲肾上腺素转运体（NET）下调需要 NET-T258/S259 转运基序。本研究利用细胞通透性 NET-T258/S259 基序干扰肽，该肽可阻断 AMPH 诱导的 NET 下调，以探讨这种 NET 调节形式在 AMPH 介导的行为中的作用。在接受 TAT 缀合肽的脑室内微注射的大鼠中，该肽包含 NET-T258/S259 基序，急性全身 AMPH 未能抑制 TAT-NET-T258/S259 WT 肽注射半球中的 NE 转运，但在载体或随机肽注射半球中却未抑制。与接受脑室内载体或 TAT-NET-T258A/S259A 突变肽或相应 TAT 缀合的随机肽的大鼠相比，接受脑室内 TAT-NET-T258/S259 WT 肽的大鼠的急性 AMPH 诱导的多动性显著降低。肽单独输注不会改变基础运动活性。同样，在接受 AMPH 挑战之前，接受脑室内 TAT-NET-T258/S259 WT 肽的大鼠的 AMPH 诱导的运动敏化显著降低，而接受突变体或随机肽的大鼠则没有。在条件性位置偏好（CPP）范式中，在 CPP 测试之前，单次双侧脑室内 TAT-NET-T258/S259 WT 肽的微注射显著降低了 AMPH 诱导的 CPP 表达。同样，在药物挑战之前，单次双侧脑室内 TAT-NET-T258/S259 WT 肽的微注射显著减弱了 AMPH 引发的 CPP 重新表达。另一方面，双侧脑室内随机肽的微注射不影响 AMPH 诱导的 CPP 表达或重新表达。这些数据表明，T258/S259 依赖性 NET 调节在 AMPH 诱导的多动性和敏化以及 AMPH 诱导的 CPP 表达和重新表达中起作用。
