Song Liya, Li Lihua
Department of Children's Center, Beijing Luhe Hospital Affiliated to Capital Medical University, Beijing, 101149, China.
Open Life Sci. 2024 Dec 31;19(1):20221014. doi: 10.1515/biol-2022-1014. eCollection 2024.
This study aimed to investigate the differential expression of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in relation to the Toll-like receptor (TLR)/nuclear factor κB (NF-κB) signaling pathway in an obese rat model. A total of 200 8-week-old male Wistar rats were randomly assigned to a control group (Ctrl, = 40) and an observation group (Obs, = 160), with obesity induced through a high-fat diet. Following modeling, the Obs group was further divided into a model group, a PI3K/AKT inhibition group, a TLR/NF-κB inhibition group, and a combined PI3K/AKT + TLR/NF-κB inhibition group, with 40 rats in each. Metabolic changes were assessed by monitoring the glucose infusion rate (GIR), as well as conducting an intraperitoneal glucose tolerance test (IPGTT) and an intraperitoneal insulin tolerance test (IPITT). Hematoxylin and eosin staining was utilized to observe morphological changes in adipose tissue, while Western blotting was employed to detect the expression levels of proteins associated with the PI3K/AKT and TLR/NF-κB signaling pathways in adipose tissue. The results indicated that the Obs group exhibited significantly higher blood glucose and insulin levels during the IPGTT and IPITT experiments compared to the Ctrl group ( < 0.05). Additionally, the GIR, as well as the expression levels of p-PI3K and p-AKT proteins in the Obs group, were significantly lower than those in the Ctrl group ( < 0.05). In both the PI3K/AKT inhibition group and the combined PI3K/AKT + TLR/NF-κB inhibition group, the expression of relevant proteins further declined ( < 0.05). These findings suggest that while a high-fat diet decreases the activity of the PI3K/AKT signaling pathway, it concurrently promotes inflammatory responses by upregulating the TLR-4 and NF-κB signaling pathways, indicating a critical role for these pathways in obesity-related metabolic abnormalities.
本研究旨在探讨肥胖大鼠模型中磷酸肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路与Toll样受体(TLR)/核因子κB(NF-κB)信号通路的差异表达。总共200只8周龄雄性Wistar大鼠被随机分为对照组(Ctrl,n = 40)和观察组(Obs,n = 160),通过高脂饮食诱导肥胖。建模后,观察组进一步分为模型组、PI3K/AKT抑制组、TLR/NF-κB抑制组和联合PI3K/AKT + TLR/NF-κB抑制组,每组40只大鼠。通过监测葡萄糖输注速率(GIR)以及进行腹腔葡萄糖耐量试验(IPGTT)和腹腔胰岛素耐量试验(IPITT)来评估代谢变化。采用苏木精-伊红染色观察脂肪组织的形态变化,同时利用蛋白质印迹法检测脂肪组织中与PI3K/AKT和TLR/NF-κB信号通路相关的蛋白质表达水平。结果表明,与对照组相比,观察组在IPGTT和IPITT实验期间的血糖和胰岛素水平显著更高(P < 0.05)。此外,观察组的GIR以及p-PI3K和p-AKT蛋白的表达水平显著低于对照组(P < 0.05)。在PI3K/AKT抑制组和联合PI3K/AKT + TLR/NF-κB抑制组中,相关蛋白质的表达进一步下降(P < 0.05)。这些发现表明,高脂饮食在降低PI3K/AKT信号通路活性的同时,通过上调TLR-4和NF-κB信号通路促进炎症反应,表明这些通路在肥胖相关代谢异常中起关键作用。