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

Abstract

To investigate the expression of the long isoform leptin receptor (OB-R(L)) and the shortest membrane bound variant (OB-R(S)) in peripheral blood mononuclear cells from the obese and normal individuals (6.08 ng/ml or 31.21 ng/ml). Mononuclear cells were obtained from 30 obese individuals (BMI > 25 kg/m2) and 20 normal individuals (BMI < 23 kg/m2). RT-PCR was used to detect the expression of OB-R(S) and OB-R(L). The level of serum leptin was measured with immunoradiometric assay. OB-R(S) was expressed in all individuals, and OB-R(L) was expressed in 38 individuals. OB-R(L) was not expressed in the 12 obese individuals with the BMI > 39 kg/m2. The expression level of OB-R(S) was 4 times higher than that of OB-R(L). There was no significant difference in the expression of either isoforms between men and women. The relative expression of both OB-R(S) and OB-R(L) 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. Both OB-R(S) and OB-R(L) are expressed in the peripheral blood mononuclear cells from normal and the medium obese subjects with a consistent predominance of OB-R(S). There is no significant difference in the expression of OB-R(S) and OB-R(L) between men and women. Compared with normal individuals, the expression of OB-R(S) and OB-R(L) in human mononuclear cells is lower.