电针疗法调节神经源性粪失禁PI3-K/Akt信号通路及肛门括约肌细胞凋亡的作用机制研究

The neuropathic fecal incontinence(FI) is a refractory disease with a poor long-term curative effects in medium and severe cases. Electrical acupuncture basing on traditional Chinese medicine likely acts through electrical neuromodulation. The potential mechanism includes inhibition of sensory and motor nerve in rectal wall, repairing of injured nerve, enhancement of the function of anal sphincter. It's still not clear about the exact ways of action and the reasons of failure. We believe that electrical acupuncture may repair injured nerve and anal sphincter and inhabit cell apoptosis by means of activating the PI3-K/Akt pathway that is in the downstream location of NGF-TrkA. The purpose of this study is to assess the effect and its timeliness on different nerves of electrical acupuncture on the expression of PI3-K/Akt, Apoptosis Index and Bax/Bcl-2, anal manometry changes in the injured nerve and anal sphincter in New Zealand rabbits with neuropathic FI, to explore the effective mechanism of electrical acupuncture therapy for neuropathic FI. We hope it can offer theoretical basis for treating neuropathic FI with electrical acupuncture and clues of breaking through the bottle-neck of curing. This study is subsequent to the study named Effective Mechanism and Timeliness of Electrical Acupuncture for Neural Injury Related Fecal incontinence via NGF-TrkA Pathway funded by Beijing Natural Science Foundation(7162166).

神经源性粪失禁是临床难治性疾病，中、重症患者远期疗效不佳。中医电针疗法治疗神经源性粪失禁可通过神经电刺激起效，其确切效应途径及失效原因仍不清楚。我们认为电针疗法的可能效应机制是通过激活PI3-K/Akt信号通路达到保护和修复受损神经和肛门括约肌的目的。而其对不同神经回路影响的差异性和时效性是影响疗效的重要因素。本研究拟通过观察电针对神经源性粪失禁新西兰兔受损神经及肛门括约肌组织内PI3-K/Akt表达、细胞凋亡指数及Bax、Bcl-2蛋白的影响，结合肛门测压结果，对照电针对不同神经回路影响的差异性和时效性，深入探讨电针治疗粪失禁的作用机制，为中医电针疗法治疗粪失禁提供理论依据，并为突破治疗瓶颈提供线索。本研究是北京市自然基金项目（7162166）“基于NGF-TrkA通路探讨电针治疗神经源性粪失禁的机理及时效性研究”的后续研究。

粪失禁（Fecal incontinence，FI）指不能随意控制排气和排粪，是一个在普通人群中被隐瞒的常见问题，严重影响患者的生活质量。目前国内相关研究严重匮乏，无法满足患者需求，而我国人口老龄化将使这一矛盾日趋严重。既往研究表明，电针刺（Electroacupuncture ，EA）能明显改善损伤后肠功能，但 EA是否可以治疗神经性大便失禁尚未被研究。NGF/TrkA广泛分布于神经及肌肉组织内，EA及其他电刺激疗法（SNS、PTNS）对于NGF/TrkA表达的影响尚未清楚。因此，本项目主要目标是①观察电针疗法对粪失禁动物模型肛门静息压的影响。②初步评价EA对神经源性粪失禁肛门括约肌结构和功能的影响；③评价EA对受损神经和靶器官组织内 NGF/TrkA及下游PI3K/AKT 表达的影响及其修复作用。采用射频消融术建立大便失禁家兔模型。对照组、模型组仅捆绑20分钟不治疗，SNS组接受侧SNS刺激点针刺，PTNS组接受侧PTNS刺激点针刺，EA组接受双中髎、单侧三阴交、足三里电针刺激。治疗结束后，测量兔肛门静息压力；观察神经损伤区域及肛门内外括约肌组织形态；测定神经损伤区域及肛门括约肌组织内NGF/TrkA/PI3K/AKT以及凋亡相关蛋白Bax/Bcl2表达情况；Tunel检测肛门括约肌组织的细胞凋亡情况。结果显示，EA能明显改善肛门静息压力，减少第四骶神经和肛门括约肌组织损伤；EA可促进NGF/TrkA/PI3K/AKT的表达，缓解细胞凋亡，且效果比SNS和PTEN1更为明显。综上所述，EA疗法通过上调NGF/TrkA/PI3K/AKT表达有助于神经性大便失禁治疗。