Jia-Li Chen1, Jia-Hui Lu1, Ci-Shan Xie1, Yu-Jing Shen1, Jun-Wu Wang1, Xiu-Ying Ye1, Mao-Biao Zhang1, Gai-Li Jia1, Yuan-Xiang Tao2, Jun Li1, Hong Cao1. 1. Department of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Pain Medicine Institute of Wenzhou Medical University Zhejiang 325035, China. 2. Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey Newark, New Jersey 07103, USA.
Abstract
OBJECTIVE: The present study determines whether Cav-1 modulates the initiation, development and maintenance of type-2 DNP via the Rac1/NOX2-NR2B signaling pathway. METHODS: After regular feeding for three days, these rats were randomly divided into two groups: control group with normal-diet (maintenance feed) (n=8); type-2 DM group (n=8). In the type-2 DM group, the rats were fed with a high-fat and high-sugar diet, and received a single intraperitoneal streptozotocin (STZ) injection (35 mg/kg). At two weeks after STZ injection, these diabetic neuropathic pain (DNP) rats were treated with daidzein (0.4 mg/kg/day) and N-tert-Butyl-α-phenylnitrone (PBN, 100 mg/kg/day) for 14 days. After the type-2 DNP model was successfully established, the rats were assigned into four groups: DNP group, DNP+Da group (DNP rats with Cav-1 specific inhibitor daidzein), DNP+PBN group (DNP rats treated with ROS scavenger PBN), and SC group (solvent control group). Then, the mechanical and thermal hyperalgesia were assayed to evaluate the function of the caveolin 1-Recombinant Human Ras-Related C1/nicotinamide adenosine diphosphate oxidase 2-NR2B gene (Cav-1-Rac1/NOX2-NR2B) signaling pathway. In the mechanism study, the protein expression levels of p-Caveolin-1, Rac1, NOX2, p-NR2B and t-NR2B, the production of ROS, and the distribution of Cav-1 and NOX2 in the spinal cord were observed. RESULTS: The present study revealed that p-Cav-1 was persistently upregulated and activated in the spinal cord microglia in type-2 DNP rats. The use of the pharmacological inhibitor of Cav-1 and a ROS scavenger resulted to a significantly relieved mechanical allodynia and thermal hyperalgesia. In addition, it was demonstrated that Cav-1 promoted ROS generation via the activation of Rac1-dependent NADPH oxidase (NOX). CONCLUSION: The present data suggests that Cav-1 in the spinal cord modulates type-2 DNP via regulating the Rac1/NOX2-NR2B pathway. AJTR
OBJECTIVE: The present study determines whether Cav-1 modulates the initiation, development and maintenance of type-2 DNP via the Rac1/NOX2-NR2B signaling pathway. METHODS: After regular feeding for three days, these rats were randomly divided into two groups: control group with normal-diet (maintenance feed) (n=8); type-2 DM group (n=8). In the type-2 DM group, the rats were fed with a high-fat and high-sugar diet, and received a single intraperitoneal streptozotocin (STZ) injection (35 mg/kg). At two weeks after STZ injection, these diabetic neuropathic pain (DNP) rats were treated with daidzein (0.4 mg/kg/day) and N-tert-Butyl-α-phenylnitrone (PBN, 100 mg/kg/day) for 14 days. After the type-2 DNP model was successfully established, the rats were assigned into four groups: DNP group, DNP+Da group (DNPrats with Cav-1 specific inhibitor daidzein), DNP+PBN group (DNPrats treated with ROS scavenger PBN), and SC group (solvent control group). Then, the mechanical and thermal hyperalgesia were assayed to evaluate the function of the caveolin 1-Recombinant Human Ras-Related C1/nicotinamide adenosine diphosphate oxidase 2-NR2B gene (Cav-1-Rac1/NOX2-NR2B) signaling pathway. In the mechanism study, the protein expression levels of p-Caveolin-1, Rac1, NOX2, p-NR2B and t-NR2B, the production of ROS, and the distribution of Cav-1 and NOX2 in the spinal cord were observed. RESULTS: The present study revealed that p-Cav-1 was persistently upregulated and activated in the spinal cord microglia in type-2 DNPrats. The use of the pharmacological inhibitor of Cav-1 and a ROS scavenger resulted to a significantly relieved mechanical allodynia and thermal hyperalgesia. In addition, it was demonstrated that Cav-1 promoted ROS generation via the activation of Rac1-dependent NADPH oxidase (NOX). CONCLUSION: The present data suggests that Cav-1 in the spinal cord modulates type-2 DNP via regulating the Rac1/NOX2-NR2B pathway. AJTR