二氢杨梅素对P2X7受体介导的2型糖尿病大鼠糖尿病神经病理痛合并抑郁症的作用研究

The incidence of type 2 diabetes mellitus (type 2 DM) is increasing. Diabetic neuropathic pain (DNP) is one of the most common harmful complications of type 2 DM, and some patients with DNP suffer from depression at the same time, seriously affecting the quality of life. The P2X7 receptor of glial cells plays an important role in the comorbidity of DNP and depression. Our preliminary experiments showed that in dorsal root ganglia (DRGs), spinal cord and hippocampus of type 2 diabetic rats with the comorbidity of DNP and depression, the expression of P2X7 receptor, GFAP, OX42 and IL-1β was obviously higher than those in the control rats, and the brain-derived neurotrophic factor (BDNF) in hippocampus of type 2 diabetic rats with the comorbidity of DNP and depression was decreased significantly compared with the control rats. Preliminary experiments also found that treatment with traditional Chinese medicine dihydromyricetin(DHM) significantly alleviated the hyperalgesia and depression-like behavior of type 2 diabetic rats with the comorbidity of DNP and depression, and decreased the expression of the up-regulated P2X7 receptor, GFAP, OX42 and IL-1β, while significantly increased the expression of the BDNF in hippocampus. Thus, the aim of the project is to investigate whether the DHM can influence P2X7 receptor of glial cells in the DRGs, spinal cord and hippocampus of type 2 diabetic rats to improve the comorbidity of DNP and depression. Furthermore, the project will provide new experimental evidences for the prevention and treatment of the comorbidity of DNP and depression.

2型糖尿病发病率日益增加，糖尿病神经病理痛(DNP)是糖尿病中危害较大的一个常见并发症，其中有部分DNP患者会合并抑郁症共同发病，严重影响患者生活质量。胶质细胞的嘌呤2X7受体（P2X7）涉及疼痛和抑郁病症，可能在疼痛和抑郁共病中起重要作用。预实验显示2型糖尿病DNP合并抑郁症大鼠的背根神经节（DRG）、脊髓、海马P2X7受体、GFAP、OX42、IL-1β表达明显高于对照组，海马区脑源性神经营养因子（BDNF）和对照组相比显著下降。应用中药提取物二氢杨梅素（DHM）治疗后能缓解痛敏，减轻抑郁样行为，并且降低DRG、脊髓和海马中升高的P2X7受体、GFAP、OX42、IL-1β的表达，提高海马区BDNF表达。因此，本项目拟研究二氢杨梅素是否通过影响胶质细胞的P2X7受体表达影响DNP合并抑郁症，为寻找DNP合并抑郁症的防治新方法提供实验基础。

2型糖尿病发病率日益增加，糖尿病神经病理痛(DNP)是糖尿病中危害较大的一个常见并发症，其中有部分DNP患者会合并抑郁症共同发病，严重影响患者生活质量。胶质细胞的嘌呤2X7受体(P2X7)涉及疼痛和抑郁，可能在疼痛和抑郁共病中起重要作用。本项目建立了DNP合并抑郁症大鼠模型，观察中药提取物二氢杨梅素(DHM)对DNP合并抑郁症大鼠的影响，探索其可能的作用机制。我们研究发现DNP合并抑郁症大鼠的痛敏和触诱发痛以及抑郁样行为在DHM治疗或P2X7受体shRNA干扰后明显好转。DNP合并抑郁症大鼠的背根神经节(DRG)、脊髓、海马P2X7受体、p-ERK1/2、TNF-α、IL-1β表达明显高于对照组，应用DHM治疗或P2X7受体shRNA干扰后能逆转。此外，研究结果表明DNP合并抑郁症大鼠的海马区脑源性神经营养因子(BDNF)和其受体TrkB水平下降，但脊髓和DRG中BDNF/TrkB水平升高，DHM治疗后可以逆转BDNF/TrkB水平的异常表达。此外，在本项目中，我们应用高葡萄糖(HG)，P物质(SP)和皮质酮(CORT)共培养的原代海马星形胶质细胞来模拟DNP合并抑郁症状况下的细胞损伤模型。结果表明HG+SP+CORT共同培养细胞是探索糖尿病神经病理性疼痛和抑郁症细胞损伤的可行性细胞模型。DHM可以保护HG+SP+CORT共培养的原代海马星形胶质细胞免受P2X7受体介导的损伤。全细胞膜片钳实验结果表明DHM显著抑制了转染P2X7受体的HEK293细胞的P2X7受体激动剂激活电流。因此，P2X7受体可能成为防治DNP合并抑郁症的新靶点，DHM有望成为治疗糖尿病神经病理性疼痛合并抑郁症的潜在有效药物。