The Expression Of PAR4in The Dorsal Root Ganglion Sensory Neurons And The Coexistence With TRPV1

PurposeProtease-activated receptor4(PAR4), is one of the protease activated receptor familymembers, belongs to the G-protein coupled receptor. Studies have found that PAR4innormal and inflammatory conditions are involved in the regulation of pain response, atpresent,the mechanism of PAR4in the regulation of pain is not clear, may be theintracellular signal transduction mechanism for peripheral sensory neurons, part of whichmay be mediated by sensitized transient receptor potential vanilloid subtype1(Transientreceptor potential vanilloid1TRPV1) involvement peripheral noxious stimulation regulation.The purpose of experiment is to further understand the expression of PAR4in the dorsal rootganglion (dorsal root ganglion, DRG) primary sensory neurons t, and the coexistence withnociceptive sensory receptor TRPV1, to provide a morphological basis for exploringPAR4in peripheral nociceptive sensory signaling role.Method1Application of immunofluorescence histochemical double-labeling method combinedwith confocal laser microscopy technique, to observe the expression of PAR4in theprimary sensory neurons of rat and mouse DRG and the coexistence with TRPV1.2. Establishment of visceral pain rats animal model through Intraperitoneal injection ofacetic acid, and application of immunofluorescence histochemical double-labeling methodcombined with confocal laser microscopy technique, to observe the expression changes ofPAR4in DRG primary sensory neurons.Result1PAR4can be expressed in DRG primary sensory neurons of the mouse and canCo-existe with TRPV1. Through immunofluorescence, it is showed that a large number ofDRG sensory neurons expressed PAR4, A lot of small circular, oval neurons and a smallnumber of large neurons can be seen., as well as a few positive neurons fibers.80.5%+ 3.1%(3672/4558) of neurons expressed PAR4. Through immune fluorescent doublelabeling method,it was displayed that a lot of the TRPV1positive neurons can be seen inthe DRG,they are the middle and small sensory neuron cell bodies, the expression ofPAR4positive neurons in DRG can co-exist with TRPV1.76.9%+3.4%(2826/3672) ofoPAR4positive neurons expressed TRPV1and77.4%+3.1%(2826/3647) of TRPV1positive neurons expressed PAR4.2PAR4can be expressed in DRG primary sensory neurons of the rat and can Co-existewith TRPV1. The expression of PAR4in rat DRG and in mice DRG are similar, a largenumber of sensory neurons expressed PAR4, A lot of small circular, oval neurons and asmall number of large neurons can be seen., as well as a few positive neurons fibers. It isshowed trough cell count:85.4%.4.1%(4337/5078) of neurons expressed PAR4. ThroughImmune fluorescent double labeling method,it is showed that83.5%+3.6%(3623/4337)of PAR4positive neurons expressed TRPV1and88.3%+3.5%(3623/4102) of TRPV1positive neurons expressed PAR4.3.PAR4and CGRP can co-exist in DRG primary sensory neurons of the rat. Throughimmunofluorescence,it was revealed that a large number of sensory neurons positive forCGRP can be seen in the DRG of rat, A lot of small circular, oval neurons and a smallnumber of large neurons can be seen., as well as a few CGRP positive neurons fibers.75.6%+4.1%(3387/4478) of positive neurons expressedCGRP. Through immunefluorescent double labeling method,it is showed that82.3%+4.6%(2788/3387) of PAR4positive neurons contained CGRP and64.2%+3.7%(2788/4337) of CGRP positive cellsexpressed PAR4.4TRPV1and CGRPcan co-exist in DRG primary sensory neurons of the rat.TRPV1positive neurons in DRG and CGRP positive cells are similar, they are middle,smallsensory neuron cell bodies and some diffuse nerve fiber. Immunofluorescence doubledisplay that TRPV1/CGRPcan co-exist in DRG sensory neurons within a widerange,83.9%+3.6%(2842/3387) of CGRP positive cells expressed TRPV1and69.2%+3.2%(2842/4102) of TRPV1positive cells were in CGRP, we can also see a smallnumber of a single TRPV1labeled neurons or single CGRP labeled neurons.5PAR4expression changes in DRG sensory neurons of visceral pain rats animalmodel.In visceral pain rats animal models, the number of PAR4positive sensory neurons inDRG increased, it was showed through cell count that the number of PAR4positive sensoryneurons compared to normal ratsincreaseby11.1%+2.3%,96.5%+4.3%(5336/5528)neuronalexpressed PAR4. At the same time, the number of the TRPV1positive neurons in DRG alsoincreased,95%+4.4%(5110/5378) of neurons expressed TRPV1. Immunofluorescencedouble display more PAR4/TRPV1double-labeled cells, respectively, PAR4positive andTRPV1positive cells of88.8%+3.7%(4742/5336) and92.7%+3.4%(4742/5110). Theexperimental results show that in rat DRG seen in many sensory neurons express PAR4, andTRPV1wide coexistence.Conclusion1.PAR4in rat and mouse DRG on primary sensory neurons have a wide range ofexpression, mainly in middle,small neurons.2.PAR4and TRPV1in DRG on primary sensory neurons can co-exist widely, PAR4engaging the outer peripheral noxious stimuli may be associated with the TRPV1functionregulation, probably by affecting TRPV1involved in nociception regulation.3in visceral pain rats animal model, PAR4in DRG expression was markedly increased,PAR4has an important role in the transmission of visceral noxious stimulation process...