Impact Of ZAG Plasimid Transfection And Aerobic Exercise On Expression ZAGmRNA In White Adipose Tissue And UCP-3mRNA In Skeleton Muscle Of High-fat Diet Induced Obese Mice

Objective: Controlling weight should weigh on the decreased fat instead of lean bodymass. Zinc-α2-glycoprotein (ZAG) is a novel adipokine that there is rare reports aboutits relationship with exercise. The study is to observe the impact of aerobic exerciseand ZAG plasmid DNA transfecting on weight, blood lipids, expression ofZinc-α2-glycoprotein (ZAG) mRNA in adipose tissue and UCP-3mRNA in skeletonmuscle of High-fat diet (HFD) induced obese mice, to further investigate themechanisms of anti-obesity exercise and provide the valid foundation of anti-obesitydrug.Design: Randomly chose8six-weeks old KM male mice as the control group(C,n=8).And the rest mice were bred with high-fat diet to build the obese animal model. After12weeks,45mice matching the obese standard which is20%above the averageweight of control group were randomly divided into5groups: sedentary obesegroup(DC, n=9), vehicle group(DV, n=9), ZAG plasmid DNA injection group(DZ,n=9), aerobic exercise group(DE, n=9) and ZAG expression plasmid DNA plusexercise group(DZ+E, n=9). These5groups continued to feed on high-fat diet. DEand DZ+E were administered with8weeks moderate intensity treadmillrunning(10m/min for the first four weeks,12m/min for the last four weeks,60min/day,5days/week). DZ and DZ+E were transfected by the total300μl mixture of ZAGexpression plasmid (5μg) in150μl OPTI-MEM medium (serum-free) andlipofectamine2000(10μl) in150μl OPTI-MEM medium through i.v..(2times/week,8weeks).On the other hand, DV were subjected to300μl background solutioninjection as control. Weight was observed every3days and after8weeksintervention, the weight gain, the weight of visceral fat and bilateral triceps surae, TC,TG, HDL-C, LDL-C were measured. The expression of ZAGmRNA in adipose tissueand UCP-3mRNA in skeletal muscle were determined by Realtime-PCR.Results: Following the8weeks different interventions, the weight gain of DZsignificantly lowered than DC (p<0.01)and DV(p<0.05), and DZ+E had the largestdecline(p<0.01);compared to DC, the weight and the relative weight of visceral fat inDZ(p<0.01), DE (p<0.05)and DZ+E (p<0.01)decreased. Even though there were nosignificant change between the three groups, DZ+E was lower than the other two;Therelative weight of skeletal muscle of DZ and DZ+E were higher in contrast to DC(p<0.01), DV and DE (p<0.05); each group’s serum LDL-C levels were similar(p>0.05), and serum HDL-C levels in DZ and DZ+E elevated; TG levels in DE wereless than DC,DV and DZ(p<0.01，p<0.05). ZAGmRNA expressions in DZ, DZ+E andDE markedly increased(p<0.01),besides DZ+E had the largest rise; UCP-3mRNAexpressions in DZ improved compared with DC,DV(p<0.05) and DE(p<0.01), no significance with DZ+E(p>0.05), in the other hand DE lessen than DZ and DZ+E(p<0.01).Conclusions：1) ZAG plasmid transfection can ascend the expression of ZAGmRNAand UCP-3mRNA in vivo to reduce the relative weight of visceral fat and meantimeto increase the relative weight of skeletal muscle, improve the condition of bloodlipids.2) Long time aerobic exercise can ameliorate the conditions of obesity through addingthe expression of ZAGmRNA. But in this case, that whether ZAG directly induce theUCP-3mRNA to increase the energy consumption is unclear.3)8weeks modest aerobic exercise may have the synergistic effect that are able todecrease the more relative weight of visceral fat and wax the relative weight ofskeletal muscle comparing with the single intervention.