自噬对肝郁脾虚型IBS-D内脏高敏感性的调控机制及痛泻要方干预研究

Diarrehea-predominant irritable bowel syndrome（IBS-D）is a common disease of the digestive system. The disease is refractory and protracted,often recurring after treatment.It could severely threaten physical and mental health of the patients. Previous research has indicated that stagnation of liver qi and spleen deficiency is main pathogenesis of IBS-D,Abdominal pain and diarrehea are main symptoms of IBS-D,both the pathogenesis and symptoms are related to visceral hypersensitivity(VH),the smoothing liver and invigorating spleen treatment could significantly improve the VH. Visceral hypersensitivity is the main pathophysiology of IBS,but its pathogenesis remains not fully understood. New research has indicated that autophagy could regulate pain threshold and painful sensibility,it provide the basis for researching VH base on autophagy. Combined with the early stage of the team, we propose a hypothesis: Autophagy inhibition of spinal dorsal horn exists in VH rat modle of IBS-D, By inhibiting mTORC2 promote autophagy of spinal dorsal horn to weaken the induction, formation and maintenance of central sensitization through NMDA-PKC-ERK1/2 signaling pathway, accordingly to improve VH of IBS-D. This project aim to research VH from autophagy, which would be of great significance to supplement and perfect the VH mechanism.From the aspects of traditional Chinese medicine:Autophagy inhibition of spinal dorsal horn could promote and maintain VH,it is related to the stagnation of liver qi and spleen deficiency which is the main pathogenesis of IBS-D. The changes in the correlative signaling pathway may be reflected in the micro level of liver stagnation and spleen deficiency, therefore, it would be of great theoretical significance and clinical application potential to explain the intervention mechanism of the Tongxieyao formula which used in syndrome of stagnation of liver qi and spleen deficiency of IBS-D.

腹泻型肠易激综合征(IBS-D)病情迁延难愈，治疗后易复发，严重危害患者身心健康。我们前期研究发现：IBS-D的核心病机是肝郁脾虚，主症为痛泻，与内脏高敏感性(VH)密切相关，疏肝健脾法对其疗效显著。VH是IBS-D的核心病理生理基础，但其发生机制尚未完全明确。研究发现：自噬对痛阈和疼痛敏感性有调控作用，结合前期基础，我们提出假说：肝郁脾虚型IBS-D内脏高敏感大鼠存在脊髓后角自噬抑制，促进脊髓后角自噬可减弱NMDA-PKC-ERK1/2信号通路对中枢敏化的诱导、形成和维持作用，从而改善IBS-D内脏高敏感性。本项目从自噬研究VH，对完善其发生机制有重要意义。从中医方面看，脊髓后角自噬抑制对VH的促进和维持与IBS-D肝郁脾虚相关，相应的信号通路变化可能是IBS-D肝郁脾虚在微观层面的体现，由此阐释痛泻要方干预IBS-D的效应机制，具有重要的理论和临床意义。

1.项目背景：肠易激综合征（IBS）在中国的患病率约为6.5％，高发年龄段在30～59岁间，目前IBS呈现出患病人数不断增多，患病人群向青少年变化的发展趋势，使得用于诊治IBS的医疗资源消耗巨大。腹泻型肠易激综合征(IBS-D) 占IBS患者数的60%左右，但其发生机制尚未完全清楚，限制了IBS-D的临床诊疗，研究IBS-D发病机制具有重要意义。.2.研究内容：（1）自噬与IBS-D内脏高敏感性的相关性研究；（2）自噬对IBS-D内脏高敏感性的作用研究；（3）自噬相关分子mTORC2对中枢敏化关键分子PKC的调控研究；（4）痛泻要方干预IBS-D内脏高敏感性的效应机制研究。.3.重要结果：（1）自噬与IBS-D内脏高敏感性密切相关，促进自噬可改善内脏高敏感性，抑制自噬加剧内脏高敏感性。（2）mTOR-PKC-ERK1/2通路可调控自噬和内脏高敏感性。（3）痛泻要方治疗IBS-D的作用机制与抑制mTOR从而促进自噬相关。（4）脊髓后角自噬抑制对内脏高敏感性的促进和维持与IBS-D肝郁脾虚相关，相应的信号通路变化可能是IBS-D肝郁脾虚在微观层面的体现。.4.关键数据：IBS-D肝郁脾虚证模型大鼠与正常对照组大鼠相比（1）行为学指标：体重增长率和糖水消耗率显著降低（P＜0.05），而粪便含水率和腹壁撤退反射评分等显著升高（P＜0.05）；（2）内脏高敏感性指标：c-fos和PKC等显著升高（P＜0.05）；（3）自噬指标：mTOR和p62显著升高（P＜0.05），LC3B\A和LAMP1等显著降低（P＜0.05）。（4）形态学指标：脊髓后角电镜显示模型组神经元细胞核仁常染色质较多，异染色质较少，细胞胞浆中可见发生空泡变性的线粒体和溶酶体较少；结肠HE显示模型组可见炎性细胞浸润，结构受损。痛泻要方组组与IBS-D肝郁脾虚证模型大鼠相比，在行为学指标、内脏高敏感性指标、自噬指标以及形态学指标方面显著改善。.5.科学意义：从自噬角度探讨肝郁脾虚型IBS-D内脏高敏感性机制，是对以往研究的拓展和补充，有助于认识IBS-D内脏高敏感性发生发展，可为IBS-D的临床诊断和治疗提供新思路。从中医方面看，该假说有助于丰富IBS-D肝郁脾虚病机的现代生物学内涵，既“脊髓后角自噬抑制对内脏高敏感性的促进和维持与IBS-D肝郁脾虚相关，相应的信号通路变化可能是IBS-D肝郁脾虚的微观体现"。