摘要
目的:观察电针对肥胖大鼠脂质代谢和环磷酸腺苷依赖性蛋白激酶A(PKA)/环磷酸腺苷反应元件结合蛋白(CREB)信号通路的影响,探讨电针促进肥胖大鼠白色脂肪棕色化的可能机制。方法:40只8周龄雄性SD大鼠随机分为空白组(10只)、肥胖造模组(30只)。通过饲喂高脂饲料构建食源性肥胖大鼠模型。12周后将造模成功的大鼠随机分为模型组、电针组,每组10只。电针组大鼠针刺“中脘”“关元”和双侧“天枢”“丰隆”,电针刺激20 min,每天1次,每周6次,连续6周。治疗结束后,评估各组大鼠体质量、体长、腹围,计算Lee’s指数,比较各组大鼠腹股沟、附睾、肾周白色脂肪和肩胛部棕色脂肪质量,微板法检测各组大鼠血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)含量,HE染色法比较各组大鼠腹股沟白色脂肪与肩胛部棕色脂肪组织形态,Western blot法检测腹股沟白色脂肪与肩胛部棕色脂肪组织PKA、CREB、磷酸化(p)-CREB、线粒体解偶联蛋白1(UCP1)、过氧化物酶体增殖物激活受体γ共激活因子1α(PGC-1α)及甾醇调节元件结合蛋白1(SREBP-1)的蛋白相对表达水平,免疫组织化学法检测上述组织PKA、CREB、p-CREB、UCP1、PGC1-α的阳性表达,实时荧光定量PCR法检测各组大鼠腹股沟白色脂肪与肩胛部棕色脂肪组织UCP1、PGC-1α、PR结构域蛋白16(PRDM16)、过氧化物酶体增殖物激活受体γ(PPARγ)、细胞色素c氧化酶亚基7a1(Cox7a1)、细胞色素c氧化酶亚基8b(Cox8b)、碘甲状腺原氨酸脱碘酶2(DIO2)、ELOVL脂肪酸延长酶3(ELOVL3)、细胞死亡诱导DFFA样效应物a(Cidea)、T-box转录因子1(Tbx1)、跨膜蛋白26(Tmem26)、4-1BB受体(CD137)的mRNA相对表达水平。结果:与空白组相比,模型组大鼠体质量、腹围、Lee’s指数,腹股沟、附睾和肾周白色脂肪质量,血清TG、TC、LDL-C含量,以及腹股沟白色脂肪与肩胛部棕色脂肪组织中SREBP-1蛋白表达量均显著增加(P<0.001,P<0.01);而肩胛部棕色脂肪质量,血清HDL-C含量,腹股沟白色脂肪与肩胛部棕色脂肪PKA、p-CREB、UCP1、PGC-1α蛋白表达量及UCP1、PGC-1α、PRDM16、PPARγ、Cox7a1、Cox8b、DIO2、Cidea、ELOVL3、Tbx1、Tmem26、CD137 mRNA表达量均显著减少(P<0.001,P<0.01,P<0.05)。模型组大鼠腹股沟白色脂肪细胞体积显著增大,细胞内含单房大脂滴,细胞边界模糊;而棕色脂肪细胞内空泡增大增多,细胞体积显著扩增,呈白色脂肪细胞样改变。与模型组相比,电针能有效改善上述脂质代谢与白色脂肪褐变指标(P<0.01,P<0.001,P<0.05),逆转肥胖大鼠脂肪组织形态。结论:电针可能通过激活PKA/CREB信号通络,上调白色脂肪棕色化标志物UCP1、PGC-1α的蛋白表达,并上调白色脂肪棕色化相关基因,降低脂质调节蛋白SREBP-1的表达,进而调节肥胖大鼠脂质代谢,减轻其体质量。
Objective To observe the effect of electroacupuncture(EA)on lipid metabolism and cyclic adenosine monophosphate-dependent protein kinase A(PKA)/cyclic adenosine monophosphate-responsive element binding protein(CREB)signalling pathway in obese rats,so as to explore its possible mechanism in promoting browning of white fat in obese rats.Methods Forty 8-week-old male SD rats were randomly divided into blank,model and EA groups(n=10 per group).The obesity model was established by feeding the rats with high-fat diet for 12 weeks.For the EA group,EA(2 Hz/15 Hz,1.5 mA)was applied to“Zhongwan”(CV12),“Guanyuan”(CV4)and bilateral“Tianshu”(ST25)and“Fenglong”(ST40)for 20 min,once a day,6 days a week for 6 weeks.After the treatment,the body weight,body length and abdominal circumference of rats were evaluated,and Lee’s index was calculated.The weight of inguinal white adipose tissue,epididymal white adipose tissue,white adipose tissue and scapular brown adipose tissue of rats were weighed.The contents of serum total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)were measured by the microplate method.HE staining was used to detect the morphology of inguinal white adipose tissue and scapular brown adipose tissue.Western blot was used to detect the expression levels of PKA,CREB,phosphorylated(p)-CREB,mitochondrial uncoupling protein 1(UCP1),peroxisome proliferator-activated receptorγ-coactivator 1-α(PGC-1α)and sterol regulatory element binding protein 1(SREBP-1)and immunohistochemistry was used to dectect the positive expressions of PKA、CREB、p-CREB、UCP1、PGC-1αin inguinal white adipose tissue and scapular brown adipose tissue.The mRNA expressions of UCP1,PGC-1α,PR domain-containing protein 16(PRDM16),peroxisome proliferator-activated receptor gamma(PPARγ),cytochrome c oxidase subunit 7a1(Cox7a1),cytochrome c oxidase subunit 8b(Cox8b),iodothyronine deiodinase 2(DIO2),ELOVL3 fatty acid elongase 3(ELOVL3),cell death-inducing DFFA-like effector a(Cidea),T-box transcription factor 1(Tbx1),transmembrane protein 26(Tmem26),and 4-1BB receptor(CD137)in the inguinal white adipose tissue and interscapular brown adipose tissue of rats from various groups were detected by quantitative real-time PCR.Results Compared with the blank group,the body weight,abdominal circumference,Lee's index,TG,TC and LDL-C contents,white fat mass in the inguinal,epididymal and perirenal regions,and SREBP-1 protein expression were significantly increased in the model group(P<0.001,P<0.01);whereas brown fat mass in the scapular region,serum HDL-C content,PKA,p-CREB,UCP1,PGC-1αprotein expression,as well as mRNA expressions of browning-related genes such as UCP1,PGC-1α,and PRDM16 were significantly decreased(P<0.001,P<0.01,P<0.05).H.E.staining showed an increase of the volume of white adipose tissues,disordered arrangement of cells with vague boundary,meanwhile an enlarge of vacuoles and an increase volume of brown adipose tissues,present white adipocyte-like changes in the model group.Compared with the model group,EA can effectively improve the above indicators of lipid metabolism and white fat browning(P<0.01,P<0.001,P<0.05),and reverse the morphology of adipose tissues in the obese rats.Conclusion EA can effectively reduce the body weight and improve lipid metabolism in obesity rats,which is possibly associated with its functions in activating the PKA/CREB signalling pathway,up-regulating the white fat browning markers UCP1 and PGC-1αprotein expressions and white fat browning-related genes,and down-regulating the expression of the lipid regulatory protein SREBP-1.
作者
廖偲
唐成林
邱玮
杨燕
杨云昊
刘菏婧
王嘉培
邓钧元
LIAO Cai;TANG Cheng-lin;QIU Wei;YANG Yan;YANG Yun-hao;LIU He-jing;WANG Jia-pei;DENG Jun-yuan(Chongqing Key Laboratory of Chinese Medicine for Prevention and Treatment of Metabolic Diseases,School of Traditional Chinese Medicine,Chongqing Medical University,Chongqing 410007,China)
出处
《针刺研究》
北大核心
2025年第5期553-566,共14页
Acupuncture Research
基金
国家自然科学基金面上项目(No.81273870)
重庆市财政局、重庆市卫生健康委员会针灸推拿学重点学科建设项目(No.渝财社[2021]179号)。
