PPAR-α # 510120 PPAR-α SD SD 6 4 RT-PCR?? mrna FFA TG HOME-IR FFA 2.37±0.60 1.59±0.30 1.33±0.34 mmol/l p<0.001 TG 0.48±0.11 0.30±0.04 0.36±0.07 mmol/l p<0.001 HOME-IR 12.30±3.97 5.03±1.88 4.17±1.27 p<0.001 TNF-α mrna 1.726±1.408 0.713±0.711 0.593±0.382 p 0.032 0.660±0.192 0.949±0.35 0.936±0.130 p 0.029 AGT 1 AT1R 6 IL-6 mrna p>0.05 PPAR-α PPAR-α Effect of PPAR-α agonist on adipokines expression in rats fed with high-fat diet LI yan#, HUANG bin, CHENG hua, LIANG zhen, LIU shan-ying Department of Endocrinology, The Second Affiliated Hospital of Sun Yat-sen University, Guangzhou 510120, China Abstract Objective To explore the influence of PPAR-α agonist fenofibrate on adipokines expression in high-fat diet fed SD rats and its relationship to insulin resistance (IR). Methods Rats were allocated into three groups(n=10): high fat diet, high fat diet plus treatment with fenofibrate, and normal diet group. Animals were sacrificed after 4-week follow-up. Plasma lipids, fasting plasma insulin, free fatty acids (FFA) and insulin sensitivity were detected. RT-PCR was used to semi-quantify adipokines expression in brown fat. Results High-fat diet was
associated with increase in plasma level of lipids, free fatty acid (FFA), fast plasma insulin, HOMA-IR, increased expression of TNF-α and decreased adiponectin expression in adipose tissues. Fenofibrate reversed these changes. Conclusion PPAR-α agonist fenofibrate may play a role in improving high fat diet induced lipid abnormalities and insulin sensitivity, which were associated with down-regulation of TNF-α expression and up-regulated adiponectin expression in adipose tissues. Key words PPAR-α agonist, adipokines, free fatty Acid,insulin resistance # Corresponding author Tel: 13710634920, E-mail: liyan19642002@yahoo.com
IR FFA TG [1] -a TNF-α -6 IL-6 AGT 1 AT1 mrna SD 30 8 200g + 10 4.43 g/100g 9.9 20 Wt Wt 23.5 g/100g 45.05 1 6 20mg.kg -1.d -1 4 5ml kg -1 d -1 10 g 20 FFAs Randox Linco research inc. HOMA-IR 2 100mg 2ml 80 mrna RT-PCR -actin Pubmed TNF-α adiponcetin cdna Primer 5.0
1. TNF-α 5 -CCAACAAGGAGGAGAAGTTCC-3 5 -TGGGAGTAGATAAGGTACAGC C-3 249bp β-actin 5 -CTATCGGCAATGAGCGGTTC-3 5 -CTTAGGAGTTGGGGGTGGCT-3 734bp 5 3 5 3 β-actin 5 - TGGTCGTACCACTGGCATTGTG -3 5 - TGACCTGACCGTCAGGCATCTC -3 308bp 3. adiponcetin 5 - ATCACTCAGCATTCAGCG TAGG -3 5 - ATACACTTGGAGCCAGACTTGG -3 317bp β-actin IL-6 4. AGT 5 -ACC CCT TTC ATC TCC TCT ACT-3 5 -GGG TGT CTG GCT GCT GCT TCC-3 488bp β-actin 5 -CTA TCG GCA ATG AGC GGT TC-3' 5 -CTT AGG AGT TGG GGG TGG CT-3'; 734bp 5. AT1R 5 -TGT TTT ATG GCT TTC TGG GG-3 5 -CAG TGG CTT TGC TCC AAT TT-3 418bp β-actin AGT Trizol Invitrogen RNA A 260 RNA RT RNA 1µg 5 5µl dntp TaKaRa 10mmol/l 5µl TaKaRa 2µl RNA
TaKaRa 25U MMLV Promega 200U RNA 25µl Biometra T GRADIENT 37 1h 95 5min MMLV PCR 4 PCR RT 5µl 10 PCR 5µl MgCl 2 23mM 3µl dntp 2.5mmol/l 4µl 20µM 1µl β-actin 1µl Taq TaKaRa 2U 50µl Biometra T GRADIENT TNF-α β-actin 95 5min 94 1min 57 1min 72 1 30 33 72 10min IL-6 adiponcetin β-actin 95 5 Taq 94 1 60 1 72 1 30 35 72 10 PCR PCR PCR 5µl 2 5V/cm SYBR Green AlphaImager 2200 /β-actin mrna 3 ±s LSD P 0.05 HOMA IR 10 FFA TG HOMA-IR 1 1 SD 4 (n=10) (n=10) (n=10) F P FBG mmol/l 4.94±.33 5.85±.66 5.51±1.01 4.061.029 FINS mmol/l 0.911±0.31 1.87±0.51.68±0.18 30.73 0.001
TG mmol/l 0.30±4.3 E-02 0.48±.11 0.36±7.2 E-02 13.80 0.001 FFA mmol/l 1.59±.30 2.37±.60 1.33±.34 15.36 0.001 HOMR-IR 5.03±1.88 12.30±3.97 4.17±1.27 28.67 0.001 P<0.05 P TNF-α mrna P<0.05 mrna P<0.05 AGT 1 AT1R 6 IL-6 mrna P>0.05 2 (n=10) (n=10) (n=10) P TNF-α 0.713±0.711 1.726±1.408 0.593±0.382.032 0.949±0.35 0.660±0.192 0.936±0.130.029 IL-6 0.29 AGT 1.489±1.318 3.337±2.431 2.245±1.741 0.14 AT1R 1.995±2.642 2.627±1.884 1.060±1.371 0.28 P<0.05 P / [2] TG FFA -a peroxisome proliferator-activated receptor-a PPARa [3] SD HOMA-IR
FFA TG mrna mrna FFA FFA [4] PPARa [5] TNF-a IL-6 TNF-a LPL TNF-a TNF-α κb NF-κB IKK IRS-1 [6] TNF-a TNF-α mrna TNF-α IL-6 SOCS SOCS IRS-1 IRS-1 [7] IL-6 mrna IL-6 IL-6 [8] SOCS - RAS II [9] II 1 mrna RAS mrna
camp A camp dependent protein kinase AMPK FFA β FFA[10] PPARa FFA TG mrna 1. Garber AJ. The Metabolic syndrome. Med Clin North Am, 2004, 88(4): 837-846. 2. Hotamisligil GS. Inflammatory pathways and insulin action. Int J Obes, 2003, 27: S53-S55 3. Fazio S, Linton MF. The role of fibrates in managing hyperlipidemia: mechanisms of action and clinical efficacy.curr Atheroscler Rep, 2004, 6(2):148-57. 4. Dresner A, Laurent D, Marcucci M, et al. Effects of free fatty acids on glucose transport and IRS-1-associated phosphatidylinositol 3-kinase activity. J Clin Invest, 1999, 103:253-259. 5. Minnich A, Tian N, Byan L, et al. A potent PPARalpha agonist stimulates mitochondrial fatty acid beta-oxidation in liver and skeletal muscle. Am J Physiol Endocrinol Metab, 2001, 280(2):E270-279. 6. Yuan M, Konstantopoulos N, Lee J, et al. Reversal of Obesity- and Diet-Induced Insulin Resistance with Salicylates or Targeted Disruption of Ikkb. Science, 2001, 293:1673-1677 7. Zick Y. Uncoupling insulin signaling by serine/threonine phosphorylation: a molecular basis for insulin resistance. Biochem Soc Transaction, 2004, 32:812-816. 8. Okopien B, Krysiak R, Herman ZS. Effects of short-term fenofibrate treatment on circulating markers of inflammation and hemostasis in patients with impaired glucose tolerance. J Clin Endocrinol Metab, 2006, 91(5):1770-1778. 9. Velloso LA, Folli F, Sun X J et al. Cross-talk between the insulin and angiotensin signaling systems, PNAS, 1996, 93: 12490-12495. 10. Havel PJ. Update on Adipocyte Hormones. Diabetes, 2004, 53:S143-S151.