中国神经再生研究(英文版) ›› 2018, Vol. 13 ›› Issue (9): 1657-1664.doi: 10.4103/1673-5374.232530

• 原著:周围神经损伤修复保护与再生 • 上一篇    下一篇

夹竹桃麻素减轻糖尿病神经性疼痛的作用及机制

  

  • 收稿日期:2018-06-22 出版日期:2018-09-15 发布日期:2018-09-15
  • 基金资助:

     土耳其Ege大学研究基金

Treatment with NADPH oxidase inhibitor apocynin alleviates diabetic neuropathic pain in rats

Murat Olukman1, Aytül Önal1, Fatma Gül Çelenk2, Yiğit Uyanıkgil3, Türker Çavuşoğlu3, Neslihan Düzenli1, Sibel Ülker1   

  1. 1 Department of Pharmacology, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey
    2 Department of Medical Genetics, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey
    3 Department of Histology and Embryology, Faculty of Medicine, Cord Blood, Cell and Tissue Research and Application Center, Ege University, Bornova, Izmir, Turkey
  • Received:2018-06-22 Online:2018-09-15 Published:2018-09-15
  • Contact: Sibel ülker, M.D.,sibel.goksel@ege.edu.tr.
  • Supported by:

    This study was supported by the Research Fund of Ege University (Project No. 2010-TIP-076).

摘要:

NADPH氧化酶(NOX)的激活可使活性氧水平增高,从而导致糖尿病并发症的发生。而夹竹桃麻素作为NOX抑制剂可增加糖尿病大鼠的坐骨神经传导速度和血流量。为研究夹竹桃麻素对糖尿病神经病变大鼠的潜在保护作用及相关的分子机制。实验以链霉素诱导的方法建立糖尿病大鼠模型,然后以灌胃夹竹桃麻素(30和100mg/kg/d)干预4周。每周使用止痛剂和动态足底感觉计测定机械性痛觉过敏和异常性疼痛阈值,作者发现了这样的现象:(1)注射链脲佐菌素可降低止痛剂的疼痛阈值,而夹竹桃麻素治疗以剂量依赖性增加疼痛阈值;(2)Western印迹分析显示脊髓中过氧化氢酶和NOX-p47phox蛋白表达增加,而神经元型和诱导型一氧化氮合酶、超氧化物歧化酶、谷胱甘肽过氧化物酶、硝基酪氨酸、肿瘤坏死因子-α、白细胞介素-6、白细胞介素-1β、醛糖还原酶,环氧合酶-2或小神经胶质细胞增生标志物MAC-1无明显变化;(3)两种剂量夹竹桃麻素可明显降低模型大鼠脊髓NOX-p47phox蛋白表达,100mg/kg/d的夹竹桃麻素可使过氧化氢酶表达降低。组织化学染色结果显示糖尿病坐骨神经明显变性。免疫组化染色结果显示,模型大鼠坐骨神经中nNOS和iNOS免疫阳性反应明显增加,而Schwann细胞标志物S100免疫阳性反应明显降低;夹竹桃麻素干预可剂量依赖性地逆转这些变化;(4)以上结果说明,糖尿病大鼠神经性疼痛的发生伴随着脊髓中NOX和过氧化氢酶表达的增加以及坐骨神经中NOS表达的增加,并以许旺细胞损失为表现特征,而夹竹桃麻素可通过抑制糖尿病大鼠氧化应激介导的病理反应来减轻神经性疼痛。

orcid:0000-0003-0236-8047(Sibel Ülker)

 

关键词: 夹竹桃麻素, 糖尿病并发症, 实验性糖尿病, 神经性疼痛, NADPH氧化酶, 坐骨神经, 脊髓, Western印迹, 周围神经损伤, 神经再生

Abstract:

Increased reactive oxygen species by the activation of NADPH oxidase (NOX) contributes to the development of diabetic complications. Apocynin, a NOX inhibitor, increases sciatic nerve conductance and blood flow in diabetic rats. We investigated potential protective effect of apocynin in rat diabetic neuropathy and its precise mechanism of action at molecular level. Rat models of streptozotocin-induced diabetes were treated with apocynin (30 and 100 mg/kg per day, intragastrically) for 4 weeks. Mechanical hyperalgesia and allodynia were determined weekly using analgesimeter and dynamic plantar aesthesiometer. Western blot analysis and histochemistry/immunohistochemistry were performed in the lumbar spinal cord and sciatic nerve respectively. Streptozotocin injection reduced pain threshold in analgesimeter, but not in aesthesiometer. Apocynin treatment increased pain threshold dose-dependently. Western blot analysis showed an increase in catalase and NOX-p47phox protein expression in the spinal cord. However, protein expressions of neuronal and inducible nitric oxide synthase (nNOS, iNOS), superoxide dismutase, glutathion peroxidase, nitrotyrosine, tumor necrosis factor-α, interleukin-6, interleukin-1β, aldose reductase, cyclooxygenase-2 or MAC-1 (marker for increased microgliosis) in the spinal cord remained unchanged. Western blot analysis results also demonstrated that apocynin decreased NOX-p47phox expression at both doses and catalase expression at 100 mg/kg per day. Histochemistry of diabetic sciatic nerve revealed marked degeneration. nNOS and iNOS immunoreactivities were increased, while S-100 immunoreactivity (Schwann cell marker) was decreased in sciatic nerve. Apocynin treatment reversed these changes dose-dependently. In conclusion, decreased pain threshold of diabetic rats was accompanied by increased NOX and catalase expression in the spinal cord and increased degeneration in the sciatic nerve characterized by increased NOS expression and Schwann cell loss. Apocynin treatment attenuates neuropathic pain by decelerating the increased oxidative stress-mediated pathogenesis in diabetic rats.

Key words: apocynin, diabetic complications, experimental diabetes mellitus, neuropathic pain, NADPH oxidase, sciatic nerve, spinal cord, Western blotting, peripheral nerve injury, neural regeneration