基于JAK2/STAT3信号通路探讨益脉颗粒调控白色脂肪棕色化干预高脂小鼠学习记忆障碍作用机制

Exploration on the mechanism of Yimai Granules regulating white fat browning in the intervention of learning and memory impairment in high-fat mice based on JAK2/STAT3 signaling pathway

目的:探讨益脉颗粒通过JAK激酶2(JAK2)/信号转导及转录激活蛋白3(STAT3)信号通路调控白色脂肪棕色化干预高脂小鼠学习记忆障碍的作用机制。方法:将40只C57BL/6J小鼠按照随机数表法分为对照组、模型组、益脉颗粒组和辛伐他汀组,每组10只,对照组以普通饲料喂养,模型组、益脉颗粒组和辛伐他汀组以高脂饲料持续喂养44周建立高脂学习记忆障碍模型,益脉颗粒组(7.2g/kg)与辛伐他汀组(1.76mg/kg)于第14周分别以相应药物进行灌胃,对照组与模型组以等体积0.9%氯化钠溶液进行灌胃,每日2次,持续给药30周。44周后采用Morris水迷宫和空间探索实验对小鼠学习记忆能力进行检测,HE染色观察海马CA1区形态及附睾附近白色脂肪组织形态,ELISA检测小鼠血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平及白色脂肪匀浆上清液瘦素(LP)含量,WesternBlot检测UCP-1、PRDM16、P-JAK2、JAK2、P-STAT3、STAT3蛋白表达水平。结果:与对照组比较,模型组小鼠逃避潜伏期及空间定向穿梭能力下降(P<0.01),海马CA1区神经元排列不均匀且出现液化坏死及胞核固缩,血清TC、TG、LDL-C水平显著升高(P<0.01),HDL-C水平显著显著降低(P<0.01),脂肪组织呈大分子空泡状,脂肪匀浆上清液中LP水平显著降低(P<0.01),脂肪组织PRDM16、UCP-1及p-JAK2/JAK2、P-STAT3/STAT3蛋白相对表达水平显著降低(P<0.01)。与模型组比较,益脉颗粒组和辛伐他汀组小鼠定向航行及学习记忆能力得到了显著改善(P<0.01),血清TC、TG、LDL-C水平显著降低(P<0.01),HDL-C水平显著升高(P<0.01,P<0.05),海马CA1区神经元逐渐完整,胞核分布均匀,脂肪组织出现多腔脂滴结构并出现棕色化趋势,脂肪匀浆中LP水平显著升高(P<0.01),脂肪组织PRDM16、UCP-1及p-JAK2/JAK2、p-STAT3/STAT3蛋白表达水平显著升高(P<0.01,P<0.05)。结论:益脉颗粒能够降低高脂学习记忆障碍模型小鼠血脂水平、改善学习记忆能力,其作用机制可能与激活JAK2/STAT3信号通路促进白色脂肪棕色化相关.

Objective:To explore the mechanism of Yimai Granules in regulating white adipose browning and intervening in learning and memory disorders in high-fat mice through the JAK kinase 2(JAK2)/signal transduction and transcriptional activation protein 3(STAT3)signaling pathway.Methods:Forty C57BL/6J mice were randomly divided into control group,model group,Yimai Granules group,and Simvastatin group using a random number table method,with 10 mice in each group.The control group was fed with regular feed,while the model group,Yimai Granules group,and Simvastatin group were continuously fed with high-fat feed for 44 weeks to establish a high-fat learning and memory impairment model.The Yimai Granules group(7.2 g/kg)and Simvastatin group(1.76 mg/kg)were gavaged with corresponding drugs at week 14,while the control group and model group were gavaged with an equal volume of 0.9%sodium chloride solution twice a day for 30 weeks.After 44 weeks,the learning and memory abilities of mice were tested using Morris water maze and spatial exploration experiments.HE staining was used to observe the morphology of the hippocampal CA1 region and the white adipose tissue near the epididymis.ELISA was used to detect the levels of total cholesterol(TC),triglycerides(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),and the content of leptin(LP)in the supernatant of the white adipose tissue homogenate.The expression levels of UCP-1,PRDM16,p-JAK2,JAK2,p-STAT3,and STAT3 proteins in mice were detected.Results:Compared with the control group,the model group mice showed a decrease in escape latency and spatial directional shuttle ability(P<0.01),uneven arrangement of neurons in the CAl area of the hippocampus,liquefaction necrosis and nuclear pyknosis,significant increase in serum TC,TG,LDL-C levels(P<0.01),and significant decrease in HDL-C levels(P<0.01).The adipose tissue appeared as large molecule vacuoles,and the LP level in the supernatant of the adipose homogenate was significantly reduced(P<0.01).The relative expression levels of PRDM16,UCP-1,p-JAK2/JAK2,p-STAT3/STAT3 proteins in adipose tissue were significantly reduced(P<0.01).Compared with the model group,the targeted navigation and learning and memory abilities of mice in the Yimai Granules and Simvastatin groups were significantly improved(P<0.01),while serum TC,TG,and LDL-C levels were significantly reduced(P<0.01)and HDL-C levels were significantly increased(P<0.01,P<0.05),neurons in the CAl area of the hippocampus gradually became intact,nuclei were evenly distributed,and multi lumen lipid droplet structures appeared in adipose tissue with a browning trend,LP levels in adipose homogenate were significantly increased(P<0.01),and protein expression levels of PRDM16,UCP-1,p-JAK2/JAK2,p-STAT3/STAT3 in adipose tissue were significantly increased(P<0.01,P<0.05).Conclusion:Yimai Granules can reduce blood lipid levels and improve learning and memory abilities in highfat learning and memory impairment model mice.Its mechanism of action may be related to activating the JAK2/STAT3 signaling pathway to promote white adipose browning.