人参皂苷Rg_(1)抑制NLRP3炎症小体对2型糖尿病小鼠视网膜病变的保护作用

Protective effect of ginsenoside Rg_(1) aganist diabetic retinopathy by inhibiting NLRP3 inflammasome in type 2 diabetic mice

人参皂苷Rg_(1)是传统名贵中药人参的主要活性成分之一。研究显示,人参皂苷Rg_(1)具有抗氧化应激、抗炎、抗衰老及神经保护等广泛的药理学作用。糖尿病性视网膜病变(diabetic retinopathy,DR)是糖尿病最常见的并发症,也是造成中老年人群视力下降和失明的主要原因。最新研究显示,人参皂苷Rg_(1)对DR也有明显的保护作用,但其对DR的保护作用及机制研究较少,仍需要进一步研究。该实验主要研究人参皂苷Rg_(1)对2型糖尿病小鼠视网膜病变的保护作用及机制。采用高脂饲料(high fat diet,HFD)+链脲佐菌素(streptozotocin,STZ)诱导2型糖尿病小鼠模型,苏木精-伊红(hematoxylin-eosin staining,HE)染色观察小鼠视网膜病理学情况;采用免疫组化研究核苷酸结合寡聚化结构域样受体3(nucleotide-binding oligomerization domain-like receptors 3,NLRP3)和血管内皮生长因子(vascular endothelial growth factor,VEGF)在视网膜的定位及表达情况;采用Western blot检测视网膜核因子-κB(NF-κB)、p-NF-κB、NLRP3、半胱氨酸天冬氨酸特异性蛋白酶-1(caspase-1)、白细胞介素-1β(IL-1β)、瞬时受体电位阳离子通道蛋白6(transient receptor potential channel protein 6,TRPC6)、活化T细胞核因子2(activated T-cell nuclear factor 2,NFAT2)和VEGF的表达情况。结果显示,人参皂苷Rg_(1)处理能明显减轻2型糖尿病小鼠视网膜病理学损伤;免疫组化结果显示,人参皂苷Rg_(1)明显降低2型糖尿病小鼠视网膜神经节细胞、中网状层和外网状层NLRP3和VEGF的表达;免疫印迹结果显示,人参皂苷Rg_(1)明显降低2型糖尿病小鼠视网膜p-NF-κB、NLRP3、caspase-1、IL-1β、TRPC6、NFAT2和VEGF的表达。这些研究结果表明,人参皂苷Rg_(1)处理能明显减轻2型糖尿病小鼠视网膜病变,其机制可能与抑制视网膜NLRP3炎症小体和VEGF表达有关。该研究为临床应用人参皂苷Rg_(1)治疗糖尿病视网膜病变提供实验依据。

Ginsenoside Rg_(1),one of the main active components of precious traditional Chinese medicine Ginseng Radix et Rhizoma,has the anti-oxidative stress,anti-inflammation,anti-aging,neuroprotection,and other pharmacological effects.Diabetic retinopathy(DR),the most common complication of diabetes,is also the main cause of impaired vision and blindness in the middle-aged and the elderly.The latest research shows that ginsenoside Rg_(1) can protect patients against DR,but the protection and the mechanism are rarely studied.This study mainly explored the protective effect of ginsenoside Rg_(1) against DR in type 2 diabetic mice and the mechanism.High fat diet(HFD)and streptozotocin(STZ)were used to induce type 2 diabetes in mice,and hematoxylin-eosin(HE)staining was employed to observe pathological changes in the retina of mice.The immunohistochemistry was applied to study the localization and expression of nucleotide-binding oligomerization domain-like receptors 3(NLRP3)and vascular endothelial growth factor(VEGF)in retina,and Western blot was used to detect the expression of nuclear factor-kappa B(NF-κB),p-NF-κB,NLRP3,caspase-1,interleukin-1β(IL-1β),transient receptor potential channel protein 6(TRPC6),nuclear factor of activated T-cell 2(NFAT2),and VEGF in retina.The results showed that ginsenoside Rg_(1) significantly alleviated the pathological injury of retina in type 2 diabetic mice.Immunohistochemistry results demonstrated that ginsenoside Rg_(1) significantly decreased the expression of NLRP3 and VEGF in retinal ganglion cells,middle plexiform layer,and outer plexiform layer in type 2 diabetic mice.According to the Western blot results,ginsenoside Rg_(1) significantly lowered the expression of p-NF-κB,NLRP3,caspase-1,IL-1β,TRPC6,NFAT2,and VEGF in retina of type 2 diabetic mice.These findings suggest that ginsenoside Rg_(1) can significantly alleviate DR in type 2 diabetic mice,which may be related to inhibition of NLRP3 inflammasome and VEGF.This study provides experimental evidence for the clinical application of ginsenoside Rg_(1) in the treatment of DR.