ASIC3在缓激肽B1受体激活引起炎性皮损区瘙痒反应中的作用研究

发布时间：2018-05-12 20:08

本文选题：ASIC3 + 瘙痒　；参考：《南方医科大学》2017年硕士论文

【摘要】：瘙痒是皮肤疾病和一些系统疾病的常见临床症状之一,严重影响睡眠,降低患者生活质量。急性瘙痒主要由某些致痒物质引起的,慢性瘙痒主要由皮肤疾病和某些系统性疾病引起。临床上治疗瘙痒以传统的抗组胺治疗为主,但对于大多数的慢性瘙痒,效果往往不佳。瘙痒的发病机制至今不是很清楚,目前普遍认为瘙痒并不是由单一因素引起的,而是由致痒物质、皮肤神经纤维、角质形成细胞、皮肤屏障、外周中枢神经系统间的复杂相互作用的结果。常用的完全弗氏佐剂(complete Freund' S adjuvant,CFA)炎症模型进行触诱发痒实验发现,炎症皮损区出现痒觉敏化,并且缓激肽受体(bradykinin receptor,BR)在其中起到关键作用。缓激肽(bradykinin,BK)是目前已知的最强的致痛物质也是重要的致炎因子。缓激肽及其代谢产物des-Arg(9)-bradykinin,des-Arg(10)-kallidin通过结合细胞膜上的特异性缓激肽受体发挥生物作用。缓激肽受体是一种九肽段蛋白耦联受体(G.protein.coupled receptor,GPCR)受体。正常生理情况下B1R除中枢神经系统组少量表达外其他组织几乎不表达,而在细菌脂多糖(lipopolysaccharide,LPS)、炎症、创伤等情况诱导下迅速表达,是一种诱导性表达受体。皮内注射B1R受体激动剂可引起CFA炎症模型小鼠产生搔抓行为,但B1R受体激动剂引起瘙痒的下游机制至今不是很清楚。有研究指出机体炎症,对应的背根神经节(dorsal root ganglion,DRG)酸敏感性离子通道(Acid-sensing ion channels,ASICs)表达上升,干皮症小鼠ASIC3基因敲除或使用特异阻断剂均可使搔抓行为减弱。B1R激动剂引起瘙痒是否与背根神经节上ASIC3表达增加有关值得进一步深入探讨。研究方法:模型制备:C57BL/6J鼠七氟醚麻醉后颈背部皮肤剃毛,皮内注射CFA,96h后进行行为学观察。实验前置于Plexiglas盒内适应30 min,麻醉后腹腔预注射ASIC3阻断剂APETx2,对照组腹腔注射生理盐水,腹腔注射后立即放入Plexiglas盒内。30min后,于七氟醚麻醉后颈背部炎性皮损区皮内注射BIR激动剂,放入Plexiglas盒内观察小鼠后肢搔抓药物注射部位的次数,每只小鼠的观察时间为30 min。观察结束后处死取相应节段DRG,western blot检测DRG中ASIC3表达情况。为进一步探讨ASIC3参与瘙痒是否具有选择性,本研究检验了 APETx2是否能抑制DCP模型小鼠自发痒以及急性致痒物质:氯喹(chloroquine,CQ),内皮素-1(endothelin-1,ET-1)、48/80 混合物(48/80 compound)诱发的瘙痒。结果:1.抑制ASIC3通路显著减弱小鼠B1R激动剂诱发的炎性皮损区瘙痒行为。较对照组,实验组腹腔预注射APETx2明显减弱小鼠的搔抓行为(Figl-1,*P0.05),表明ASIC3参与B1R激动剂诱发的瘙痒。2.抑制ASIC3通路只能减弱某些致痒物质引起的瘙痒。腹腔预注射APETx2明显减弱氯喹引起的瘙痒(Fig2-2,*P0.05),但对48/80compound,ET-I引起的搔抓行为无明显减弱作用(Fig2-2,*P0.05).3.抑制ASI3通路减弱DCP自发痒模型小鼠的搔抓行为。实验组腹腔注射APETx2小鼠30min内搔抓次数显著较对照组减少(Fig2-1,*P0.05)。4.皮肤炎症刺激引起DRG上ASIC3表达增加。CFA引起的炎症皮损区对应节段的DRG上ASIC3表达较正常鼠有明显的增加(Figl-2)。结论:炎症刺激引起DRG上ASIC3表达上调。ASIC3通路参与B1R激动剂及CQ引起的瘙痒,但不参与ET-1、48/80compound引起的瘙痒。结论ASIC3可能参与B1R激活引起瘙痒的下游机制ASIC3参与瘙痒的调节具有选择性
[Abstract]:Itching is one of the common clinical symptoms of skin diseases and some systemic diseases, which seriously affect sleep and reduce the quality of life of the patients. Acute itching is mainly caused by some itchy substances. Chronic itching is mainly caused by skin diseases and some systemic diseases. The pathogenesis of chronic pruritus is often poor. The pathogenesis of itching is not very clear. It is generally believed that itching is not caused by a single factor, but is the result of the complex interaction between the itching, skin nerve fibers, keratinocytes, skin barrier, and the peripheral nervous system. C Omplete Freund'S adjuvant, CFA) an itching experiment of the inflammatory model found that there was a tickling sensitization in the inflammatory zone and the key role of the bradykinin receptor (bradykinin receptor, BR). Bradykinin (bradykinin, BK) is the strongest pain causing substance known at present and an important inflammatory factor. Bradykinin and its metabolite Des-Arg (9) -bradykinin, des-Arg (10) -kallidin plays biological action by binding the specific bradykinin receptor on the cell membrane. The bradykinin receptor is a G.protein.coupled receptor receptor (G.protein.coupled receptor, GPCR) receptor. Under normal physiological conditions, B1R is almost expressed in a small amount of other tissues except for a small amount of the central deity system. It is an inducible expression receptor that is induced by bacterial lipopolysaccharide (lipopolysaccharide, LPS), inflammation and trauma. Intradermal injection of B1R receptor agonist can cause Scratch behavior in CFA model mice, but the downstream mechanism of pruritus caused by B1R receptor agonists is not very clear. The expression of dorsal root ganglion (DRG) acid sensitive ion channel (Acid-sensing ion channels, ASICs) is increased. The activity of ASIC3 gene knockout in dry skin mice, or using specific blockers, may weaken the scratch behavior of.B1R agonists and whether it is related to the increase of ASIC3 expression on the dorsal root ganglion. Study method: model preparation: model preparation: C57BL/6J rat after sevoflurane anesthesia after the skin shaving, intradermal injection of CFA, 96h after the behavioral observation. The experiment was prepositioned in the Plexiglas box to adapt to 30 min, after the anesthesia, the abdominal preinjection ASIC3 blocker APETx2, the control group intraperitoneal injection of physiological salt water, after intraperitoneal injection into Plexiglas box.30min after immediately after the injection. After sevoflurane anaesthesia, the BIR agonist was injected into the skin of the back of the back of the neck. The times of the injection site of the mouse hind limbs were observed in the Plexiglas box. The observation time of each mouse was 30 min. and the corresponding segment DRG was killed and Western blot was used to detect the expression of ASIC3 in DRG. Whether or not it is selective, this study examined whether APETx2 could inhibit itching in DCP model mice and acute itchy substances: chloroquine (chloroquine, CQ), endothelin -1 (endothelin-1, ET-1), and 48/80 mixture (48/80 compound) induced pruritus. Results: 1. inhibition of ASIC3 pathway significantly diminished the inflammatory skin pruritus induced by mice B1R agonists. Compared with the control group, the preinjection of APETx2 in the experimental group significantly weakened the scratch behavior of mice (Figl-1, *P0.05), indicating that ASIC3 involved in B1R agonist induced pruritus.2. inhibited ASIC3 pathway only to weaken the itching caused by some itchy substances. Peritoneal injection of APETx2 significantly weakened the pruritus (Fig2-2, *P0.05) caused by chloroquine (Fig2-2, *P0.05), but to 48/80compound, The scratch behavior caused by ET-I was not significantly weakened (Fig2-2, *P0.05).3. inhibited the scratch behavior of DCP self itching model mice. In the experimental group, the number of scratching in 30min of APETx2 mice was significantly lower than that of the control group (Fig2-1, *P0.05).4. skin inflammation stimulated the inflammatory skin lesion caused by the increased expression of the DRG. The expression of ASIC3 on the segment of DRG was significantly increased (Figl-2). Conclusion: inflammatory stimulation causes ASIC3 expression on DRG to increase.ASIC3 pathway to participate in B1R agonist and CQ induced pruritus, but does not participate in ET-1,48/80compound induced pruritus. Conclusion ASIC3 may participate in the regulation of pruritus downstream of B1R activation to participate in pruritus. Selectivity

【学位授予单位】：南方医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R758.31

【参考文献】