背景:灵芝(G.灵芝)被中国人视为“神奇的草药”,并详细记录在“神农本草经”中,作为改善健康和延长寿命的补品。蛋白聚糖(即,FYGL)是从灵芝中提取的,这是一种水溶性超支化蛋白聚糖,并被发现能够保护胰腺组织免受氧化应激损伤。
目的:糖尿病肾病(DKD)是糖尿病的并发症,但仍缺乏有效的治疗方法。糖尿病患者慢性高血糖诱发ROS积累,损伤肾组织并导致肾功能障碍。在这项工作中,研究了FYGL对糖尿病肾功能的疗效和目标机制。
方法:在本研究中,在高糖(HG)和棕榈酸酯(PA)(HG/PA)诱导的糖尿病db/db小鼠和大鼠肾小球系膜细胞(HBZY-1)上分析了FYGL的肾保护机制。体外,活性氧(ROS)的水平,通过市售试剂盒评估丙二醛(MDA)和超氧化物歧化酶(SOD)。NOX1和NOX4的表达,MAPK和NF-κB的磷酸化,通过蛋白质印迹测量促纤维化蛋白。在体内,糖尿病db/db小鼠用FYGL灌胃8周,每周测试体重和空腹血糖(FBG)。第8周,血清,收集尿液和肾组织进行葡萄糖耐量试验(OGTT),氧化还原指示剂(SOD,CAT,GSH和MDA),脂质代谢(TC,TG,LDL和HDL),血尿素氮(BUN),血清肌酐(Scr),尿酸(UA),8-氧代脱氧鸟苷(8-OHdG),以及组织病理学改变和胶原IV和AGEs的表达。
结果:体外实验结果显示FYGL显著抑制HG/PA诱导的HBZY-1细胞增殖,ROS生成,MDA生产,促进SOD活性,并抑制NOX1,NOX4,MAPK,NF-κB,和促纤维化蛋白表达。此外,FYGL显著缓解血糖,抗氧化活性和脂质代谢,改善肾功能,减轻肾脏组织病理学异常,尤其是肾纤维化.
结论:FYGL的抗氧化活性可以减少糖尿病引起的ROS,保护肾脏免受氧化应激引起的功能障碍。从而改善肾功能。这项研究表明,FYGL具有治疗糖尿病肾病的潜力。
BACKGROUND: Ganoderma lucidum (G. lucidum) was regarded as \"miraculous herb\" by the Chinese and recorded detailly in the \"Shen Nong Ben Cao Jing\" as a tonic to improve health and prolong life. A proteoglycan (namely, FYGL) was extracted from Ganoderma lucidum, which was a water-soluble hyperbranched proteoglycan, and was found to be able to protect pancreatic tissue against oxidative stress damage.
OBJECTIVE: Diabetic kidney disease (DKD) is a complication of diabetes, but the effective treatment is still lack. Chronic hyperglycemia in diabetic patients induce the accumulation of ROS, which injure the renal tissue and lead to the renal dysfunction. In this work, the efficacy and target mechanics of FYGL on diabetic renal function were investigated.
METHODS: In the present study, the mechanism of the reno-protection of FYGL was analyzed on diabetic db/db mice and rat glomerular mesangial cells (HBZY-1) induced by high glucose (HG) with palmitate (PA) (HG/PA). In vitro, the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were evaluated by commercial kits. the expressions of NOX1 and NOX4, phosphorylation of MAPK and NF-κB, and pro-fibrotic proteins were measured by Western blot. In vivo, diabetic db/db mice were gavaged with FYGL for 8 weeks, body weight and fasting blood glucose (FBG) were tested weekly. On 8th week, the serum, urine and renal tissue were collected for glucose tolerance test (OGTT), redox indicator (SOD, CAT, GSH and MDA), lipid metabolism (TC, TG, LDL and HDL), blood urea nitrogen (BUN), serum creatinine (Scr), uric acid (UA), 8-oxo-deoxyguanosine (8-OHdG), and the changes of histopathology and expression of collagen IV and AGEs.
RESULTS: The results in vitro showed that FYGL significantly inhibited the HG/PA-induced HBZY-1 cells proliferation, ROS generation, MDA production, promoted SOD activity, and suppressed NOX1, NOX4, MAPK, NF-κB, and pro-fibrotic proteins expression. In addition, FYGL markedly alleviated blood glucose, antioxidant activity and lipid metabolism, improved renal functions, and relieved renal histopathological abnormalities, especially renal fibrosis.
CONCLUSIONS: The antioxidant activity of FYGL can reduce ROS caused by diabetes and protect renal from oxidative stress-induced dysfunction, thereby improving renal function. This study shows that FYGL has the potential to treat diabetic kidney disease.