HDL和ApoA-Ⅰ模拟肽对3T3-L1脂肪细胞脂联素表达的影响

目的观察高密度脂蛋白(HDL)和载脂蛋白A-I(ApoA-Ⅰ)模拟肽对炎症状态下3T3-L1脂肪细胞脂联素的分泌和mRNA表达的影响,并探讨其可能的作用机制。方法3T3-L1脂肪细胞促分化成熟后,脂多糖(LPS)刺激脂肪细胞处于炎症状态,给予不同浓度的HDL(10～100mg·L-1)和ApoA-Ⅰ模拟肽(1～50mg·L-1)干预,收集细胞和培养上清液,测定细胞上清液脂联素浓度,脂肪细胞脂联素和PPARγmRNA表达水平,及核因子-κB(NF-κB)活性。结果LPS刺激使上清液中脂联素浓度由0·25±0·03μg·L-1降低至0·14±0·02μg·L-1(P<0·05)。HDL和ApoA-Ⅰ模拟肽呈剂量依赖性增加炎症状态下脂肪细胞脂联素分泌和mRNA表达。与LPS刺激组(0·36±0·05)比较,10、50、100mg·L-1HDL分别使脂联素mRNA表达升高2、2·9和4·2倍,而1、10、50mg·L-1ApoA-Ⅰ模拟肽分别使脂联素mRNA表达升高2·2、3·9和4·4倍(P均<0·05)。PPARγ在分化成熟的3T3-L1脂肪细胞有较高水平的表达,与炎症状态下比较,PPARγ表达在HDL和ApoA-Ⅰ模拟肽干预后明显升高(2·85±0·69vs0·38±0·19,2·92±0·96vs0·38±0·19;P<0·05);而NF-κB活性在HDL和ApoA-Ⅰ模拟肽干预后明显减低(0·48±0·09vs1·93±0·59,0·43±0·08vs1·93±0·59;P<0·05)。结论HDL和ApoA-Ⅰ模拟肽能上调炎症状态下脂肪细胞脂联素的表达和分泌,其作用机制可能与PPARγ和NF-κB途径有关。

Effects of high density lipoprotein and apolipoprotein A- Ⅰ mimetic peptide on the expression of adiponectin in 3T3-L1 adipocytes

Aim To explore the effect of high density lipoprotein and apolipoprotein A-I mimetic peptide on the secretion and the expression of adiponectin in fully differentiated 3T3-L1 adipocytes in inflammatory status and the possible mechanism.Methods Fully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentrations of high density lipoprotein(10~100 mg·L-1) and apolipoprotein A-I mimetic peptide(1~50 mg·L-1)with 100 μg·L-1 lipopolysaccharide(n=3).Evaluate the levels of adiponectin in supernatant,the mRNA expression of adiponectin and PPARγ,and the activity of NF-κB.Results During LPS stimulation adiponectin concentrations in supernatant decreased from 0.25±0.03 μg·L-1 to 0.14±0.02 μg·L-1(P<0.05).HDL and ApoA-Ⅰ mimetic peptide dose-dependently increased adiponectin secretion and mRNA expression.Compared with LPS stimulation,treatment with HDL at 10,50,100 mg·L-1 significantly enhanced that about to 2,2.9,4.2-fold respectively(P<0.05),and treatment with ApoA-Ⅰ mimetic peptide at 1,10,50 mg·L-1 significantly enhanced that about to 2.2,3.9,4.4-fold respectively(P<0.05).Peroxisome proliferator-activated receptor γ(PPARγ) presented high level expression in fully differentiated 3T3-L1 adipocytes.Compared with LPS stimulated group,HDL and ApoA-Ⅰ mimetic peptide significantly enhanced PPARγ mRNA expression(2.85±0.69 vs 0.38±0.19 and 2.92±0.96 vs 0.38±0.19 respectively,P<0.05),and decreased significantly the activity of nuclear factor-κB(NF-κB)0.48±0.09 vs 1.93±0.59 and 0.43±0.08 vs 1.93±0.59 respectively,P<0.05.Conclusions HDL and ApoA-Ⅰ mimetic peptide could upregulate the secretion and mRNA expression of adiponectin in 3T3-L1 adipocytes in inflammatory status.PPARγ and NF-κB pathway may participate in the process.