尋找有效治療慢性發炎性疼痛是目前臨床研究上重要的課題。組織受損釋放大量發炎介質引起的發炎反應常常會伴隨著持續性以及慢性疼痛的發生。發炎介質會透過蛋白質激酶A以及蛋白質激酶Cɛ活化痛覺相關神經元 (nociceptor)，引發痛覺過敏感行為。在前人研究中指出，在預發炎的模式中 (priming model) 蛋白質激酶Cɛ可能扮演關鍵的角色在轉換急性疼痛至慢性發炎性疼痛中。但另外利用發炎介質引發持續性的疼痛研究中發現蛋白質激酶A同時與蛋白質激酶Cɛ共同參與在急性以及慢性疼痛中，因此蛋白質激酶A以及蛋白質激酶Cɛ在實際上的發炎反應從開始急性痛到慢性發炎性疼痛的過程中是如何參與以及透過何種機制調控是目前尚未明瞭的課題，因此我藉由長期 (完全弗氏佐劑)、短期 (海藻醣)、神經內源性 (辣椒素) 發炎模式，在發炎反應的不同時間下注射蛋白質激酶A以及蛋白質激酶Cε抑制劑來探討蛋白質激酶A以及Cε參與那些階段下，以及他們透過何種路徑調控急性疼痛以及慢性疼痛之間的轉換。在長期以及短期模式中，抑制蛋白質激酶A只可以降低前期 (1-3小時) 發炎性疼痛，但抑制蛋白質激酶Cɛ可以降低後期 (4小時至16天)，因此推測這樣的蛋白質激酶主導由短期疼痛轉換至長期疼痛的機制主要介於發炎後3-4小時間。在辣椒素引發的短期神經內源性發炎反應中，機械性痛覺過敏只可以受抑制蛋白質激酶Cɛ所減緩，然而熱痛覺過敏感可同時受蛋白質激酶A以及蛋白質激酶Cɛ抑制劑所降低。在神經內源性發炎反應中並無顯著的激酶主導轉換，利用定量聚合酶鏈鎖反應分析發炎後酸敏感G蛋白偶和受體基因變化，發現發炎初期抑制蛋白質激酶A活性會促使G2A基因表現增加，發炎後一天TDAG8基因表現增加的現象可以受蛋白質激酶Cɛ抑制劑作用而降低。

The treatment of chronic inflammatory pain continues to be a major management challenge in clinical practice. Inflammation induced by tissue injury release inflammatory mediator often accompanies persistent and chronic pain. Inflammatory mediators activate protein kinase A (PKA) or protein kinase Cε (PKCε) to sensitize pain-related nerve fibers (nociceptors), inducing behavioral hypersensitivity. Some studies have demonstrated that PKCε plays a critical role in the transition from acute to chronic pain using “hyperalgesic priming” model. However it remains unclear whether PKA is involved in such transition, when the transition occurs and what is the molecular mechanism. To address these questions, I have used three (sub-chronic, chronic, neurogenic) inflammatory pain models to explore the roles of PKA and PKCε in the transition from acute to chronic pain. In both subchronic (carrgeenan) and chronic (CFA) models, inhibiting PKA activity reduced mechanical hyperalgesia in the early state (1-3 hours), but PKCε regulated mechanical hyperalgesia in the late state (4-24 hours). The kinase-dependent swithching time was at 3-4 hours, suggesting that the transition from acute pain to chronic pain is around 3-4 hours after inflammation. In a neurogenic model, inhibition of PKCε slightly reduced capsaicin-induced mechanical hyperalgesia but not PKA. Both PKA and PKCɛ can regulate capsaicin-induced thermal hyperalgesia. Blocking PKC reduced CFA -enhanced TDAG8 gene expression. Pretreatment of PKA inhibitor enhance G2A gene expression at initiation after CFA induced inflammation.

Aley KO, Levine JD. (1999) Role of protein kinase A in the maintenance of inflammatory pain. J Neurosci.;19(6):2181-6.
Aley KO, Messing RO, Mochly-Rosen D, Levine JD. (2000) Chronic hypersensitivity for inflammatory nociceptor sensitization mediated by the epsilon isozyme of protein kinase C. J Neurosci. 2000 ;20(12):4680-5.
Aley KO, Martin A, McMahon T, Mok J, Levine JD, Messing RO. (2001) Nociceptor sensitization by extracellular signal-regulated kinases. J Neurosci.
;21(17):6933-9.
Basbaum AI, Bautista DM, Scherrer G, Julius D. (2009) Cellular and molecular mechanisms of pain. Cell.;139(2):267-84.
Bhave G, Gereau RW. (2004) Posttranslational mechanisms of peripheral sensitization. J Neurobiol. 61(1):88-106.
Bolick DT, Whetzel AM, Skaflen M, Deem TL, Lee J, Hedrick CC. (2007) Absence of the G protein-coupled receptor G2A in mice promotes monocyte/endothelial interactions in aorta. Circ Res. 2;100(4):572-80.
Caterina MJ, Schumacher MA, Tominaga M, Rosen TA, Levine JD, Julius D. (1997) The capsaicin receptor: a heat-activated ion channel in the pain pathway. Nature ;389(6653):816-24
Caterina MJ, Leffler A, Malmberg AB, Martin WJ, Trafton J, Petersen-Zeitz KR, Koltzenburg M, Basbaum AI, Julius D: Impaired nociception and pain sensation in mice lacking the capsaicin receptor. (2000) Science , 288:306-313.

Cesare P, Dekker LV, Sardini A, Parker PJ, McNaughton PA. (1999) Specific involvement of PKC-epsilon in sensitization of the neuronal response to painful heat. Neuron. ;23(3):617-24.
Cesare P, Dekker LV, Sardini A, Parker PJ, McNaughton PA. (1999) Specific involvement of PKC-epsilon in sensitization of the neuronal response to painful heat. Neuron. ;23(3):617-24.
Chen CC, England S, Akopian AN, Wood JN. (1998) A sensory neuron-specific, proton-gated ion channel. Proc Natl Acad Sci U S A.; 95(17):10240-5.
Chen YJ, Huang CW, Lin CS, Chang WH, *Sun WH. (2009) Expression and function of proton-sensing G-protein-coupled receptors in inflammatory pain. Molecular Pain 5, 39.
Colpaert, F. C. (1987) Evidence that adjuvant arthritis in the rat is associated with chronic pain, Pain 28, 201–222.
Cook SP, McCleskey EW. (2002)Cell damage excites nociceptors through release of cytosolic ATP. Pain; 95(1-2):41-7.
Cockayne DA, Hamilton SG, Zhu QM, Dunn PM, Zhong Y, Novakovic S, Malmberg AB, Cain G, Berson A, Kassotakis L, Hedley L, Lachnit WG, Burnstock G,
McMahon SB, Ford AP.(2000) Urinary bladder hyporeflexia and reduced pain-related behaviour in P2X3-deficient mice. Nature;407(6807):1011-5.
Cook SP, McCleskey EW. (2002) Cell damage excites nociceptors through release of cytosolic ATP. Pain. ;95(1-2):41-7.
Davis JB, Gray J, Gunthorpe MJ, Hatcher JP, Davey PT, Overend P, Harries MH, Latcham J, Clapham C, Atkinson K, Hughes SA, Rance K, Grau E, Harper AJ, Pugh PL, Rogers DC, Bingham S, Randall A, Sheardown SA. (2000) Vanilloid receptor-1 is essential for inflammatory thermal hyperalgesia. Nature. ;405:183 187.10.1038/35012076.
Decaris E, Guingamp C, Chat M, Philippe L, Grillasca JP, Abid A, Minn A, Gillet P, Netter P, Terlain B. (1999) Evidence for neurogenic transmission inducing degenerative cartilage damage distant from local inflammation. Arthritis Rheum.;42(9):1951-60.
Deval E, Noël J, Lay N, Alloui A, Diochot S, Friend V, Jodar M, Lazdunski M, Lingueglia E. (2008) ASIC3, a sensor of acidic and primary inflammatory pain. EMBO J.;27(22):3047-55.
Deval E, Gasull X, Noël J, Salinas M, Baron A, Diochot S, Lingueglia E. (2010) Acid-sensing ion channels (ASICs): pharmacology and implication in pain. Pharmacol Ther; 128(3):549-58.
Dray A, Urban L, Dickenson AH.(1994) Pharmacology of chronic pain. Trends Pharmacol Sci; 15:190–197
Duan B, Wu LJ, Yu YQ, Ding Y, Jing L, Xu L, Chen J, Xu TL. (2007) Upregulation of acid-sensing ion channel ASIC1a in spinal dorsal horn neurons contributes to inflammatory pain hypersensitivity. J Neurosci. ;27(41):11139-48.
England S, Bevan S, Docherty RJ. (1996) PGE2 modulates the tetrodotoxin-resistant sodium current in neonatal rat dorsal root ganglion neurones via the cyclic AMP-protein kinase A cascade. J Physiol. ;495 ( Pt 2):429-40.
Gilchrist, H. D., Allard, B. L., and Simone, D. A.(1996) Enhanced withdrawal responses to heat and mechanical stimuli following intraplantar injection of capsaicin in rats, Pain 67, 179–188.
Gold MS, Levine JD, Correa AM. (1998) Modulation of TTX-R INa by PKC and PKA and their role in PGE2-induced sensitization of rat sensory neurons in vitro. J Neurosci. ;18(24):10345-55.
Hamilton SG, Wade A, McMahon SB. (1999) The effects of inflammation and inflammatory mediators on nociceptive behaviour induced by ATP analogues in the rat. Br J Pharmacol. ;126(1):326-32.
Huang, CW, Tzeng, JN, Chen, YJ, Tsai, WF, Chen, CC, and *Sun, WH. (2007) Nociceptors of dorsal root ganglion express proton-sensing G protein-coupled receptors. Mol. Cell. Neurosci. 36, 195-210.
Hou, C. Kirchner, T. Singer, M.Matheis, M. Argentieri, D. Cavender, D.(2003)
In vivo activity of a phospholipase C inhibitor, (U73122), in acute and chronic inflammatory reactions. J Pharmacol Exp Ther;309(2):697-704
Iadarola, M. J., Brady, L. S., Draisci, G., and Dubner, R. (1988) Enhancement of dynorphin gene expression in spinal cord following experimental inflammation: stimulus specificity, behavioral parameters and opioid receptor binding, Pain 35, 313–326
Julius D, Basbaum AI. (2001) Molecular mechanisms of nociception. Nature. 413(6852):203-10. Review
Kawabata (2011) Prostaglandin E2 and Pain—An Update. Biol. Pharm. Bull. 34(8) 1170—1173
Khasar SG, Gold MS, Levine JD. (1998) A tetrodotoxin-resistant sodium current mediates inflammatory pain in the rat. Neurosci Lett.;256(1):17-20
Khasar SG, McCarter G, Levine JD. (1999) Epinephrine produces a beta-adrenergic receptor-mediated mechanical hyperalgesia and in vitro sensitization of rat nociceptors. J Neurophysiol. 1999 ;81(3):1104-12
Khasar SG, Lin YH, Martin A, Dadgar J, McMahon T, Wang D, Hundle B, Aley KO, Isenberg W, McCarter G, Green PG, Hodge CW, Levine JD, Messing RO. (1999) A novel nociceptor signaling pathway revealed in protein kinase C epsilon mutant mice.
Khasar SG, Burkham J, Dina OA, Brown AS, Bogen O, Alessandri-Haber N, Green PG, Reichling DB, Levine JD.(2008) Stress induces a switch of intracellular signaling in sensory neurons in a model of generalized pain. J Neurosci ;28(22):5721-30.
Kidd BL, Urban LA.( 2001) Mechanisms of inflammatory pain. Br J Anaesth. Jul;87(1):3-11. Review.
Kress M, Reeh PW, Vyklicky. (1997) An interaction of inflammatory mediators and protons in small diameter dorsal root ganglion neurons of the rat. Neurosci Lett. ;224(1):37-40
Ludwig MG, Vanek M, Guerini D, Gasser JA, Jones CE, Junker U, Hofstetter H, Wolf RM, Seuwen K. H. (2003) Proton-sensing G-protein-coupled receptors. Nature 425:93-98
Malmberg AB, Brandon EP, Idzerda RL, Liu H, McKnight GS, Basbaum AI. (1997) Diminished inflammation and nociceptive pain with preservation of neuropathic pain in mice with a targeted mutation of the type I regulatory subunit of cAMP-dependent protein kinase. J Neurosci ;17:7462–70.
Millan, M. J., Czlonkowski, A., Morris, B., Stein, C., Arendt, R., Huber, A., Hollt, V.,
and Herz, A. (1988) Inflammation of the hind limb as a model of unilateral, localized
pain: influence on multiple opioid systems in the spinal cord of the rat, Pain 35, 299–312.
Moriyama T, Higashi T, Togashi K, Iida T, Segi E, Sugimoto Y, Tominaga T, Narumiya S, Murakami N, Yokomizo T, Okuno T, Shimizu T. (2004) G2A is a proton-sensing G-protein-coupled receptor antagonized by lysophosphatidylcholine. J Biol Chem.; 279:42484–42491.
Nagakura Y, Okada M, Kohara A, Kiso T, Toya T, Iwai A, Wanibuchi F, Yamaguchi T. (2003) Allodynia and hyperalgesia in adjuvant-induced arthritic rats: time course of progression and efficacy of analgesics. J Pharmacol Exp Ther.;306(2):490-7
Parada CA, Yeh JJ, Reichling DB, Levine JD. (2003) Transient attenuation of protein kinase Cepsilon can terminate a chronic hyperalgesic state in the rat. Neuroscience. ;120(1):219-26.
Reeh PW, Steen KH.Tissue acidosis in nociception and pain. Prog Brain Res. 1996;113:143-51. Review.
Sachs D, Villarreal C, Cunha F, Parada C, Ferreira Sh.(2009) The role of PKA and PKCepsilon pathways in prostaglandin E2-mediated hypernociception. Br J Pharmacol. ;156(5):826-34.
Souza AL, Moreira FA, Almeida KR, Bertollo CM, Costa KA, Coelho MM. (2002) In vivo evidence for a role of protein kinase C in peripheral nociceptive processing. Br J Pharmacol. ;135(1):239-47.

Scholz J, Woolf CJ.(2002) Can we conquer pain? Nat Neurosci. Suppl:1062-7. Review
Steen KH, Reeh PW. (1993) Sustained graded pain and hyperalgesia from harmless experimental tissue acidosis in human skin.
Taiwo YO, Levine JD, Burch RM, Woo JE, Mobley WC. Hyperalgesia induced in the rat by the amino-terminal octapeptide of nerve growth factor. Proc Natl Acad Sci U S A. 1991;88(12):5144-8.
Tominaga M, Caterina MJ, Malmberg AB, Rosen TA, Gilbert H, Skinner K, Raumann BE, Basbaum AI, Julius D. (1998) The cloned capsaicin receptor integrates multiple pain-producing stimuli. Neuron, 21:531-543.
Tominaga M. (2005) Sensitization of TRPV1 by EP1 and IP reveals peripheral nociceptive mechanism of prostaglandins. Mol Pain. ;1:3.
Vellani V, Zachrisson O, McNaughton PA. (2004)Functional bradykinin B1 receptors are expressed in nociceptive neurones and are upregulated by the neurotrophin GDNF. J Physiol.;560(Pt 2):391-401.
Villarreal, C. F. Funez, M. I. Figueiredo, F. Cunha, F. Q. Parada, C. A.Ferreira, S. H. (2009) Acute and persistent nociceptive paw sensitisation in mice: the involvement of distinct signalling pathways. Life Sci.;85(23-26):822-9
Vulchanova L, Riedl MS, Shuster SJ, Buell G, Surprenant A, North RA, Elde R. (1997) Immunohistochemical study of the P2X2 and P2X3 receptor subunits in rat and monkey sensory neurons and their central terminals. Neuropharmacology. ;36(9):1229-42.

Vinegar, R., Schreiber, W., and Hugo, R.(1969) Biphasic development of carrageenin
edema in rats, Journal of Pharmacology and Experimental Therapeutics 166, 96–103.
Wang JQ, Kon J, Mogi C, Tobo M, Damirin A, Sato K, Komachi M, Malchinkhuu E, Murata N, Kimura T, Kuwabara A, Wakamatsu K, Koizumi H, Uede T, Tsujimoto G,
Kurose H, Sato T, Harada A, Misawa N, Tomura H, Okajima F. (2004) TDAG8 is a proton-sensing and psychosine-sensitive G-protein-coupled receptor. J Biol Chem. 279(44):45626-33.
Waldmann R, Champigny G, Lingueglia E, De Weille JR, Heurteaux C, Lazdunski M.
Ann N Y. (1999) H(+)-gated cation channels.Acad Sci. 868:67-76. Review.
Waldmann R. (2001) Proton-gated cation channels--neuronal acid sensors in the central and peripheral nervous system. Adv Exp Med Biol.; 502:293-304.
Woolf CJ, Salter MW. (2000) Neuronal plasticity: increasing the gain in pain. Science. 2000 Jun 9;288(5472):1765-9.
Yen YT, Tu PH, Chen CJ, Lin YW, Hsieh ST, Chen CC. (2009) Role of acid-sensing ion channel 3 in sub-acute-phase inflammation Mol Pain 5: 1.
Yu L, Yang F, Luo H, Liu FY, Han JS, Xing GG, Wan Y. (2008) The role of TRPV1 in different subtypes of dorsal root ganglion neurons in rat chronic inflammatory nociception induced by complete Freund's adjuvant. Mol Pain.;4:61.
Zamponi GW, Feng ZP, Zhang L, Pajouhesh H, Ding Y, Belardetti F, Pajouhesh H, Dolphin D, Mitscher LA, Snutch TP. (2009) Scaffold-based design and synthesis of potent N-type calcium channel blockers. Bioorg Med Chem Lett. ;19(22):6467-72
Zhang X, Li L, McNaughton PA.(2008) Proinflammatory mediators modulate the heat-activated ion channel TRPV1 via the scaffolding protein AKAP79/150. Neuron. ;59(3):450-61
Zhang X, Li L, McNaughton PA. (2008) Proinflammatory mediators modulate the heat-activated ion channel TRPV1 via the scaffolding protein AKAP79/150. Neuron. ;59(3):450-61
Zhou Yu, Li Guo-Dong, Zhao Zhi-Qi.(2003) State-dependent phosphorylation of e-isozyme of protein kinase C in adult rat dorsal root ganglia after inflammation and nerve injury. Journal of Neurochemistry, 85, 571–580.