Iñiguez German, Ormazabal Paulina, López Teresa, Maldonado Diego, Avila Alejandra, Román Rossana, Cassorla Fernando
Institute for Maternal and Child Research (IDIMI), School of Medicine, University of Chile, Santiago, Chile.
Growth Horm IGF Res. 2009 Jun;19(3):256-61. doi: 10.1016/j.ghir.2008.12.005. Epub 2009 Feb 13.
BACKGROUND/AIMS: The GH-IGF-I axis plays an important role on pre/postnatal growth in humans, and IGF-I regulates cell proliferation, differentiation, and metabolic homeostasis. The adipose tissue has an important function in energy storage, and plays an endocrine role through the production of several hormones and growth factors. There are few studies in humans regarding IGF-I and Insulin receptor signaling in adipocytes, particularly from AGA and SGA children.
We studied 22 healthy prepubertal children (6.1+/-0.4 years), born at term (11 SGA and 11 AGA), and normal BMI at the time of the study. Primary cell cultures were established from subcutaneous adipose tissue biopsies. Preadipocytes were differentiated and stimulated with IGF-I or insulin and we studied IGF-IR, IR, AKT, and ERK content and phosphorylation.
The SGA children were shorter than the AGA children (height SDS -2.14+/-0.11 vs. 0.02+/-0.19, p<0.05). A lower content of IGF-IR, IR, AKT, and ERK was observed in adipocytes from SGA compared with AGA children. IGF-I stimulation increased IGF-IR and ERK phosphorylation in adipocytes from AGA, but not from SGA children.
The lower content and reduced phosphorylation of IGF-I signaling observed in adipocytes from SGA children may be related to the metabolic abnormalities described in these children.
背景/目的：生长激素-胰岛素样生长因子-I（GH-IGF-I）轴在人类出生前/后的生长中起重要作用，且IGF-I调节细胞增殖、分化和代谢稳态。脂肪组织在能量储存中具有重要功能，并通过产生多种激素和生长因子发挥内分泌作用。关于IGF-I和胰岛素受体在脂肪细胞中的信号传导，尤其是来自适于胎龄（AGA）和小于胎龄（SGA）儿童的研究较少。
我们研究了22名健康的青春期前儿童（6.1±0.4岁），足月出生（11名SGA和11名AGA），研究时BMI正常。从皮下脂肪组织活检建立原代细胞培养。将前脂肪细胞分化并用IGF-I或胰岛素刺激，我们研究了IGF-IR、IR、AKT和ERK的含量及磷酸化。
SGA儿童比AGA儿童矮（身高标准差评分-2.14±0.11对0.02±0.19，p<0.05）。与AGA儿童相比，SGA儿童的脂肪细胞中观察到IGF-IR、IR、AKT和ERK的含量较低。IGF-I刺激增加了AGA儿童脂肪细胞中IGF-IR和ERK的磷酸化，但SGA儿童的脂肪细胞未增加。
SGA儿童脂肪细胞中观察到的IGF-I信号传导含量降低和磷酸化减少可能与这些儿童中描述的代谢异常有关。
