Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophi...Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophic factor (BDNF) in the chronic neuropathic pain.Methods:Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The right sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The microglia inhibitor minocycline,P2X4 antagonist (TNP-ATP) and p38MAPK inhibitor (SB203580) were intrathecally administered every 12 h,3 d post-chronic constriction injury (CCI).Mechanical nociceptive thresholds were assessed with the paw withdrawal threshold (PWT) to von Frey filaments.The expression of P2X4 and BDNF were assessed by both immunohistochemical analysis and RT-PCR.Results:Intrathecal injection of minocycline or TNP-ATP or SB203580 significantly attenuated CCI-induced mechanical allodynia.The time courses of P2X4 receptor and BDNF expression were increased at all points after CCI and reached a peak level on postoperative d 7.Intrathecal injection of minocycline or TNP-ATP or SB203580 markedly suppressed the increase of CCI-induced P2X4 receptor and BDNF expression in the spinal cord.Conclusion:The activation of P2X4 receptor BDNF pathways contributes to neuropathic pain in CCI rats,and the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor.展开更多
Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats e...Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats exhibited a worse performance in the T-maze and Morris water maze(MWM) than controls.Microglia positive for P2 X purinoceptor 4(P2 X4 R) in the hippocampus were reduced and activated microglia were increased in T2 DM rats.Long Amplicon PCR(LA-PCR) showed that DNA amplification of the p2 x4 r gene in the hippocampus was lower in T2 DM rats.Minocycline significantly reduced the number of activated microglia and the mean distance traveled by T2 DM rats in the MWM.Most importantly,P2 X4 R overexpression suppressed the activated microglia and rescued the memory impairment of T2 DM rats.Overall,T2 DM led to excessive activation of microglia in the hippocampus,partly through the DNA damagemediated downregulation of P2 X4 Rs,thus contributing to memory impairment.展开更多
基金Supported by Natural Science Foundation of Shanghai,China(No. 08ZR1405000)
文摘Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophic factor (BDNF) in the chronic neuropathic pain.Methods:Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The right sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The microglia inhibitor minocycline,P2X4 antagonist (TNP-ATP) and p38MAPK inhibitor (SB203580) were intrathecally administered every 12 h,3 d post-chronic constriction injury (CCI).Mechanical nociceptive thresholds were assessed with the paw withdrawal threshold (PWT) to von Frey filaments.The expression of P2X4 and BDNF were assessed by both immunohistochemical analysis and RT-PCR.Results:Intrathecal injection of minocycline or TNP-ATP or SB203580 significantly attenuated CCI-induced mechanical allodynia.The time courses of P2X4 receptor and BDNF expression were increased at all points after CCI and reached a peak level on postoperative d 7.Intrathecal injection of minocycline or TNP-ATP or SB203580 markedly suppressed the increase of CCI-induced P2X4 receptor and BDNF expression in the spinal cord.Conclusion:The activation of P2X4 receptor BDNF pathways contributes to neuropathic pain in CCI rats,and the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor.
基金supported by grants from the National Natural Science Foundation of China (31730040,81801115, and 81920108016)the China Postdoctoral Science Foundation (2018M642304)the Priority Academic Program Development of Jiangsu Higher Education Institutions of China。
文摘Purinergic receptors have been reported to be involved in brain disorders.In this study,we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus(T2 DM).T2 DM rats exhibited a worse performance in the T-maze and Morris water maze(MWM) than controls.Microglia positive for P2 X purinoceptor 4(P2 X4 R) in the hippocampus were reduced and activated microglia were increased in T2 DM rats.Long Amplicon PCR(LA-PCR) showed that DNA amplification of the p2 x4 r gene in the hippocampus was lower in T2 DM rats.Minocycline significantly reduced the number of activated microglia and the mean distance traveled by T2 DM rats in the MWM.Most importantly,P2 X4 R overexpression suppressed the activated microglia and rescued the memory impairment of T2 DM rats.Overall,T2 DM led to excessive activation of microglia in the hippocampus,partly through the DNA damagemediated downregulation of P2 X4 Rs,thus contributing to memory impairment.
