piperidines and 4-benzyl-2-methyl-1-2-4-thiadiazolidine-3-5-dione

The aim of malignant glioma treatment is to inhibit tumor cell proliferation and induce tumor cell apoptosis. Remifentanil is a clinical anesthetic drug that can activate the N-methyl-D-aspartate (NMDA) receptor. NMDA receptor signaling activates glycogen synthase kinase-3β (GSK-3β). Discovered some 32 years ago, GSK-3β was only recently considered as a therapeutic target in cancer treatment. The purpose of this study was to assess whether remifentanil can induce the apoptosis of C6 cells through GSK-3β activation. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) was used to detect cell viability. Hoechst 33342 staining and flow cytometry were used to detect cell apoptosis. The effect of GSK-3β activation was detected using a GSK-3β activation assay kit and 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a potent and selective small molecule inhibitor of GSK-3β. The MTT assay indicated that remifentanil induced C6 cell death in a concentration- and time-dependent manner. Hoechst 33342 staining and flow cytometry showed that remifentanil significantly induced C6 cell apoptosis. The measurement of GSK-3β activation showed that remifentanil increased the cellular level of GSK-3β. All of these toxic effects can be attenuated by treatment with TDZD-8. These results suggest that remifentanil is able to induce C6 cell apoptosis through GSK-3β activation, which provides a basis for its potential use in the treatment of malignant gliomas.

Topics: Analgesics, Opioid; Animals; Apoptosis; Cell Line, Tumor; Glioma; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Piperidines; Rats; Remifentanil; Thiadiazoles

Although remifentanil provides perfect analgesia during surgery, postoperative hyperalgesia after remifentanil administration might be a challenge to anesthesiologists. The trafficking and activation of N-methyl-D-aspartate (NMDA) receptors have a pivotal role in the development and maintenance of remifentanil-induced postoperative hyperalgesia. However, the underlying mechanisms of hyperalgesia are poorly elucidated. We designed the present study to examine the hypothesis that glycogen synthase kinase (GSK)-3β could contribute to remifentanil-induced postoperative hyperalgesia via regulating NMDA receptor trafficking in the spinal cord.. Using a rat model of remifentanil-induced postoperative hyperalgesia, we first tested thermal and mechanical hyperalgesia at baseline (24 hours before incision) and 2, 6, 24, and 48 hours after remifentanil infusion. GSK-3β mRNA and protein expression and NMDA receptor subunits (NR1, NR2A, and NR2B) trafficking in the spinal cord L4-L6 segments were then measured using real-time polymerase chain reaction and Western blot analysis. Furthermore, we investigated the effects of TDZD-8, a selective GSK-3β inhibitor, on remifentanil-induced postoperative hyperalgesia and NMDA receptor subunits trafficking.. Remifentanil induced significant postoperative hyperalgesia, as indicated by increased paw withdrawal latencies and thresholds to thermal and mechanical stimulation, which were markedly improved by pretreatment with TDZD-8. Moreover, remifentanil infusion increased the expression of GSK-3β mRNA and protein as well as the GSK-3β activity in the spinal cord. More importantly, intraoperative infusion of remifentanil increased NMDA receptor subunits (NR1 and NR2B) trafficking from the intracellular pool to surface pool in the spinal cord, which was significantly attenuated by TDZD-8.. The above results suggest that activation of GSK-3β contributes to remifentanil-induced postoperative hyperalgesia via regulating NMDA receptor subunits (NR1 and NR2B) trafficking in the spinal cord. Inhibition of GSK-3β may be an effective novel option for the treatment of remifentanil-induced postoperative hyperalgesia.

Topics: Analgesics, Opioid; Animals; Blotting, Western; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hot Temperature; Hyperalgesia; Male; Pain, Postoperative; Physical Stimulation; Piperidines; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, N-Methyl-D-Aspartate; Remifentanil; RNA, Messenger; Spinal Cord; Thiadiazoles