Jin L, Tsumanuma I, Ruebel K H, Bayliss J M, Lloyd R V
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Endocrinology. 2001 May;142(5):1703-9. doi: 10.1210/endo.142.5.8117.
Pituitary folliculostellate (FS) cells are usually located between the secretory cells in the anterior pituitary, and they produce many peptides that exert a paracrine effect on hormone-producing pituitary cells. Previous approaches have been unsuccessful in obtaining homogeneous populations of FS cells. We used a combination of immunostaining with S100 protein followed by laser capture microdissection (Immuno-LCM) to obtain purified populations of rat FS cells. These cells were analyzed along with a mouse FS cell line (TtT/GF) by RT-PCR for gene expression. RT-PCR analyses showed that both FS cell populations expressed the mRNAs for glial fibrillary acidic protein, S100 protein, transforming growth factor-beta1 (TGFbeta1), TGFbeta receptor, interleukin-6, leptin, leptin receptor, pituitary adenylate cyclase-activating polypeptide (PACAP), and PACAP receptors. Both FS cell populations were negative for PRL, GH, and POMC, supporting the homogeneity of the rat FS cell population. TGFbeta1, but not PACAP-38, treatment stimulated cell proliferation in both FS cell populations. TGFbeta1 increased leptin, but not interleukin-6, mRNA expression in rat FS cells. However, TGFbeta1 inhibited leptin RNA expression in the TtT/GF cell line, as shown by RT-PCR and Northern blot analysis. These results indicate that 1) homogeneous populations of FS cells can be prepared by Immuno-LCM; 2) TGFbeta1 stimulates the proliferation of normal rat FS cells and the TtT/GF cell line; and 3) the effects of TGFbeta1 to stimulate leptin mRNA expression in rat FS cells but inhibit leptin mRNA expression in TtT/GF cells probably reflect alterations in signal transduction in the TtT/GF cell line.
垂体滤泡星状（FS）细胞通常位于垂体前叶的分泌细胞之间，它们产生许多对垂体激素分泌细胞发挥旁分泌作用的肽。以往的方法未能成功获得均一的FS细胞群体。我们采用S100蛋白免疫染色结合激光捕获显微切割（免疫-LCM）的方法来获得纯化的大鼠FS细胞群体。通过逆转录聚合酶链反应（RT-PCR）对这些细胞以及小鼠FS细胞系（TtT/GF）进行基因表达分析。RT-PCR分析表明，两个FS细胞群体均表达胶质纤维酸性蛋白、S100蛋白、转化生长因子-β1（TGFβ1）、TGFβ受体、白细胞介素-6、瘦素、瘦素受体、垂体腺苷酸环化酶激活多肽（PACAP）和PACAP受体的mRNA。两个FS细胞群体的催乳素（PRL）、生长激素（GH）和阿黑皮素原（POMC）均为阴性，这支持了大鼠FS细胞群体的均一性。TGFβ1而非PACAP-38处理可刺激两个FS细胞群体的细胞增殖。TGFβ1可增加大鼠FS细胞中瘦素而非白细胞介素-6的mRNA表达。然而，如RT-PCR和Northern印迹分析所示，TGFβ1抑制TtT/GF细胞系中的瘦素RNA表达。这些结果表明：1）可通过免疫-LCM制备均一的FS细胞群体；2）TGFβ1刺激正常大鼠FS细胞和TtT/GF细胞系的增殖；3）TGFβ1刺激大鼠FS细胞中瘦素mRNA表达但抑制TtT/GF细胞中瘦素mRNA表达的作用可能反映了TtT/GF细胞系中信号转导的改变。
