Stancu C, Coculescu M
Department of Endocrinology, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
J Med Life. 2014;7 Spec No. 3(Spec Iss 3):87-94.
Colocalization analysis of confocal fluorescence and electron microscopy (EM) are important tools to detect the expression of multiple anterior pituitary hormones within the same cell. Heterozygous (Men1+/-) mice developed pituitary tumors, mostly reported somatolactotrophinomas and ACTH secreting pituitary adenomas but also nonfunctioning tumors. The aim of the study was to run immunohistochemistry protocols to study colocalization of pituitary hormones in newborn mice in tumoral and non-tumoral tissue in MEN1-KO and wild type control mice.
Pituitary samples from nine Men1+/- mice, 29-34 days old male mice (n=8) and one year old (n=1) and control group, four new born (1,5 days old) wild type (mus musculus) mice were analyzed by immunofluorescence immunohistochemistry (GH, PRL, gonadotrophs) to find hormonal colocalization in pituitary cell. Moreover, pituitaries were embedded in LRGold for immunogold labeling technique (GH, PRL, gonadotrophs and alpha-SU) also.
Pituitary tumors, immunoreactive only for PRL were found in three MEN1 - KO mice. No sign of pituitary hyperplasia was found in MEN1-KO. MEN1-KO non-tumoral pituitary displayed similar immunoreactivity to wild type pituitary. Colocalization studies revealed individual cells PRL-FSH immunoreactive and GH-FSH immunoreactive in the non-tumoral tissue from MEN1-KO mice and in wild type pituitaries respectively but no colocalization in the tumoral tissue. In conclusion, colocalization is a feature of neonate mouse pituitary but not in adults. The MEN1-KO pituitary tumors were prolactinomas and unlike non-tumoral pituitary tissue of MEN1-KO, displayed no PRL-FSH colocalization.
共聚焦荧光与电子显微镜（EM）的共定位分析是检测同一细胞内多种垂体前叶激素表达的重要工具。杂合（Men1+/-）小鼠会发生垂体肿瘤，大多报道为生长激素泌乳素瘤和分泌促肾上腺皮质激素的垂体腺瘤，但也有非功能性肿瘤。本研究的目的是运行免疫组织化学方案，以研究MEN1基因敲除（MEN1-KO）小鼠和野生型对照小鼠新生小鼠肿瘤和非肿瘤组织中垂体激素的共定位。
对9只Men1+/-小鼠（29 - 34日龄雄性小鼠，n = 8；1岁雄性小鼠，n = 1）以及对照组4只新生（1.5日龄）野生型（小家鼠）小鼠的垂体样本进行免疫荧光免疫组织化学分析（生长激素、泌乳素、促性腺激素），以寻找垂体细胞中的激素共定位。此外，垂体也嵌入LRGold中用于免疫金标记技术（生长激素、泌乳素、促性腺激素和α-抑制素）。
在3只MEN1基因敲除小鼠中发现了仅对泌乳素呈免疫反应的垂体肿瘤。在MEN1基因敲除小鼠中未发现垂体增生迹象。MEN1基因敲除小鼠的非肿瘤性垂体与野生型垂体显示出相似的免疫反应性。共定位研究分别在MEN1基因敲除小鼠的非肿瘤组织和野生型垂体中发现了泌乳素-促卵泡激素免疫反应性和生长激素-促卵泡激素免疫反应性的单个细胞，但在肿瘤组织中未发现共定位。总之，共定位是新生小鼠垂体的一个特征，但在成年小鼠中并非如此。MEN1基因敲除小鼠的垂体肿瘤是泌乳素瘤，与MEN1基因敲除小鼠的非肿瘤性垂体组织不同，未显示泌乳素-促卵泡激素共定位。
