外周血单个核细胞内长型和短型瘦素受体的表达

Expression of long isoform leptin receptor and shortest membrane bound variant in peripheral blood mononuclear cells from the obese and normal individuals

目的探讨肥胖者和正常体重者外周血单个核细胞内长型瘦素受体(OB-R_L)和最短的膜结合瘦素受体(OB-R_S)的表达。方法从30例肥胖者(体重指数>25 kg/m^2)和20名正常体重者(体重指数<23 kg/m^2)中获取单个核细胞,利用 TRI_(ZOL)等分离试剂提取细胞内的总 RNA。应用RT-PCR 定量研究 OB-R_S 和 OB-R_L 的表达水平,用放免法检测受试者血清中瘦素的水平。结果在所有受试者中都存在 OB-R_S 表达;38例受试者存在 OB-R_L 表达,12例肥胖的受试者(BMI>39 kg/m^2)不存在 OB-R_L mRNA 表达。所有受试者的 OB-R_S 表达均高于 OB-R_L,至少4倍以上,无男女差别。肥胖者 OB-R_S 和 OB-R_L 表达水平比正常体重均显著下降,血清瘦素水平显著升高(6.08 ng/ml or 31.21ng/ml)。瘦素受体表达水平与体重指数及血清瘦素水平之间存在显著的负相关。结论外周血单个核细胞内存在 OB-R_L 和 OB-R_S 的表达,无性别差异,并且 OB-R_S 具有显著的优势性。

Objective To investigate the expression of the long isoform leptin receptor （ OB-RL ） and the shortest membrane bound variant （ OB-Rs ） in peripheral blood mononuclear cells from the obese and normal individuals （6.08 ng/ml or 31.21 ng/ml）. Methods Mononuclear cells were obtained from 30 obese individuals （ BMI 〉 25 kg/m^2 ） and 20 normal individuals （ BMI 〈 23 kg/m^2 ）. RT-PCR was used to detect the expression of OB-Rs and OB-RL. The level of serum leptin was measured with immunoradiometric assay. Results OB-Rs was expressed in all individuals, and OB-RL was expressed in 38 individuals. OB- RL was not expressed in the 12 obese individuals with the BMI 〉39 kg/m^2. The expression level of OB-Rs was 4 times higher than that of OB-RL. There was no significant difference in the expression of either isoforms between men and women. The relative expression of both OB-Rs and OB-RL isoforms was significantly lower and the serum leptin level was significantly higher in the obese individuals （ 6.08 ng/ml or 31.21 ng/ml）. The leptin receptor expression levels were significantly negatively correlated with BMI and serum leptin level. Conclusion Both OB-Rs and OB-RL are expressed in the peripheral blood mononuclear cells from normal and the medium obese subjects with a consistent predominance of OB-Rs. There is no significant difference in the expression of OB-Rs and OB-RL between men and women. Compared with normal individuals, the expression of OB-Rs and OB-RL in human mononuclear cells is lower.