Mechanism Of Spinal CCR2Modulating The Expression Of CX3CR1in Rat Model Of Bone Cancer Pain

Objective To investigate pain behaviour,spinal microglial activation and expressionof cytokines IL1-β,IL-6and TNF-α in the spinal cord after intrathecal injection of CCR2antagonistin a rat model of bone cancer pain．Methods Sixty female Sprague-Dawley rats weighing150~180g were randomlydivided into five groups (n=12each):(I)sham group;(II)sham+RS102895group;(III)bonecancer pain group;(IV)bone cancer pain+DMSO group;(V)bone cancer pain+RS102895group.Rats received i.t. Injections of either RS102895(3μg/μl)10μl or10%DMSO10μl atthe time of10-12days after the operation.1×105Walker256breast cancer cell wereseeded intra-tibial.MPWT were executed one day before and at3rd,6th,9-12th days aftersurgery.Immunofluorescence would be measured the proliferation of the spinalmicroglia.Test the expression of cytokines IL1-β,IL-6and TNF-α in the spinal cord byElisa.Results The results show that the rats in bone cancer pain group appeared obviousmechanical hyperalgesia(III、IV、V),the volume,shape and mean optical density (MOD) ofspinal microglial can be seen obviously increased,and the expression of cytokinesIL1-β,IL-6and TNF-α in the spinal cord also increased obviously.The data tells thatinjections of RS102895increased the MPWT,suppressed the action of microglias,andobviously cut down the expression of cytokines IL1-β,IL-6and TNF-α in the spinal cord.Conclusion CCR2might be participate in formation of bone cancer pain by means ofactivating spinal microglia which can promote the production of inflammatory cytokines. Objective To observe the expression of pJNK and CX3CR1after intrathecalinjection of CCR2antagonist in cancer induced pain ratsMethods1×105Walker256breast cancer cell were seeded intra-tibial in rats.Sixtyfemale Sprague-Dawley rats weighing160~180g were randomly divided into five groups(n=12each):(I)sham group;(II)sham+RS102895group;(III)bone cancer paingroup;(IV)bone cancer pain+DMSO group;(V)bone cancer pain+RS102895group.Ratsreceived i.t. Injections of either RS102895(3μg/μl)10μl or30%DMSO10μl at the time of10-12days after the operation.The expression of CX3CR1and pJNK were detected byWestern blot and immunohistochemistry.Results The number of CX3CR1positive cells moreover the expression of CX3CR1and pJNK in spinal cord was increased the rats in bone cancer pain group(III、IV、V).Theexpression of pJNK and CX3CR1in the spinal cord suppressed after injections ofRS102895.Conclusion Spinal CCR2receptor involved in the development of rats bone cancerpain may via regulating expression of CX3CR1receptor.And the regulation by way of thepJNK signal pathway possiblly. Objective To investigate the effection of intrathecal injection of SP600125onexpression of CX3CR1and MCP-1in cancer induced pain rats.Methods1×105Walker256breast cancer cell were seeded intra-tibial in rats.Fiftyfemale Sprague-Dawley rats weighing160~180g were randomly divided into five groups(n=10each):(I)sham group;(II)sham+SP600125group;(III)bone cancer paingroup;(IV)bone cancer pain+DMSO group;(V)bone cancer pain+SP600125group.Ratsreceived i.t. Injections of either RS102895(3μg/μl)10μl or30%DMSO10μl at the time of10-12days after the operation.The expression of CX3CR1and MCP-1in the spinal cord were detected by Western blot and immunohistochemistry.Results The results show that the rats the number of CX3CR1positive cells and theexpression of CX3CR1and MCP-1in spinal cord in bone cancer pain group was grew innumber(III、IV、V).The expression of CX3CR1and MCP-1were suppressed after i.t.injections of SP600125.Conclusion Intrathecal SP600125injection can partialy release bone cancer pain,JNKsignaling pathway may be participate in bone cancer pain though regulating CX3CR1and MCP-1expression.