根皮素对2型糖尿病肾病小鼠的肾保护作用及机制

王兴红; 马永超; 孙缦利; 李超敏; 李海霞

doi:10.13386/j.issn1002-0306.2022120211

根皮素对2型糖尿病肾病小鼠的肾保护作用及机制

Renal-protection Effect and the Potential Mechanism of Phloretin in Mice with Type-2 Diabetic Nephropathy

摘要

摘要: 为探究根皮素对2型糖尿病肾病小鼠肾损伤的分子保护作用及潜在机制，将小鼠随机分为正常对照组、糖尿病模型组、阳性药物组（二甲双胍500 mg/kg）、根皮素低、中、高剂量组（100、200、400 mg/kg·d）。造模成功后，各组小鼠灌胃给予相应药物，12周后，观察肾脏肥大指数、肾脏病理形态学变化，测定血尿素氮（BUN）、肌酐（Scr）和尿β2-微球蛋白（β2-MG）、血清白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）等指标，并检测肾组织丙二醛（MDA）含量、谷胱甘肽过氧化物酶（GSH-Px）活性和转录因子E2相关因子2（Nrf2）/血红素加氧酶-1（HO-1）/核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）通路相关蛋白表达。结果显示：与模型组比较，根皮素中、高剂量组小鼠肾脏肥大指数极显著减小（P<0.01）；HE染色和Masson染色见肾小球体积明显减小、系膜增生明显减少，肾小球和肾间质纤维化明显减轻；血BUN、Scr、IL-1β、IL-18和肾组织MDA含量、α-平滑肌肌动蛋白（α-SMA）、胶原蛋白Ι（Collagen Ι）、NLRP3、IL-1β和Gasdermin D（GSDMD）蛋白表达显著降低（P<0.05或P<0.01）；肾组织GSH-Px活性、Nrf2、HO-1、钙粘附蛋白-E（E-cadherin）蛋白表达显著升高（P<0.05）。结果表明：根皮素能保护2型糖尿病肾病小鼠肾功能改善肾纤维化，可能与调控Nrf2/HO-1/NLRP3通路改善氧化应激与炎症反应有关。

Abstract: To study the protective effect of phloretin against renal injury in mice with type-2 diabetic nephropathy and determine its potential mechanism at the molecular level, mice were randomized into a normal control group, diabetes model group, positive drug group (metformin, 500 mg/kg), and low-, medium-, and high-dose phloretin groups (100, 200, and 400 mg/kg·d, respectively). After successful modeling, mice in each group were administered the corresponding drugs via the intragastric route. Kidney hypertrophy index and renal pathomorphological changes were observed after 12 weeks. Blood urea nitrogen (BUN), serum creatinine (Scr), urine β2-microglobulin, serum interleukin (IL)-1β and IL-18 levels were determined. Malondialdehyde (MDA) level, glutathione peroxidase (GSH-Px) activity, and nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) pathway-related protein expression in renal tissues were also determined. Compared with the model group, the medium- and high-dose phloretin groups showed a significant decrease in the kidney hypertrophy index of mice (P<0.01). An obvious reduction in glomerular volume was determined using Hematoxylin and Eosin staining and Masson staining, and a significant decrease in mesangial proliferation and an apparent alleviation in glomerular and renal interstitial fibrosis were noted. Significant reductions in BUN, Scr, IL-1β, and IL-18 levels in the blood, in MDA levels in renal tissues, and in the protein expression of α-smooth muscle actin, Collagen I, NLRP3, IL-1β, and Gasdermin D were noted (P<0.05 or P<0.01). A significant increase in GSH-Px activity and in the expression of Nrf2, HO-1, and E-cadherin in renal tissues (P<0.05) was also founded. The results indicated that phloretin could protect renal function and alleviate renal fibrosis in mice with type-2 diabetic nephropathy. Its mechanism may be related to the regulation of the Nrf2/HO-1/NLRP3 pathway to improve oxidative stress and alleviate the inflammatory response.