Department of Veterinary Sciences and Technology for Food Safety, Veterinary Medicine Faculty, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
Cell Tissue Res. 2009 Nov;338(2):241-55. doi: 10.1007/s00441-009-0873-z. Epub 2009 Oct 8.
Lactoferrin is synthesized by glandular epithelial cells and neutrophils and is also present on both sides of the mammary epithelium. We have studied the origin of lactoferrin detected in the various compartments of mouse mammary tissue. As revealed by immunogold electron microscopy, lactoferrin is present in mammary epithelial cells and in the basal region of the epithelium, associated with connective tissue and stroma cells at all physiological stages studied. A perturbation of protein synthesis or transport after in vitro treatment with cycloheximide or brefeldin A does not abrogate lactoferrin labelling in the basal region of the epithelium. The expression of lactoferrin has also been observed in the fat pads of mammary glands from mice surgically depleted of epithelial cells. The sealing of one teat for 24 h is accompanied by an increase in both the number of stroma cells and the labelling of myoepithelial cells. Thus, the lactoferrin present in the interstitial space of the mouse mammary epithelium originates in part from stroma cells. Possible roles of lactoferrin at the basal side of the mammary epithelium are discussed.
乳铁蛋白由腺上皮细胞和中性粒细胞合成，也存在于乳腺上皮细胞的两侧。我们研究了在小鼠乳腺组织的不同隔室中检测到的乳铁蛋白的来源。如免疫金电子显微镜所示，乳铁蛋白存在于乳腺上皮细胞和上皮细胞的基底部，与在所有研究的生理阶段与结缔组织和基质细胞相关联。体外用环己酰亚胺或布雷非德菌素 A 处理后，蛋白质合成或运输的干扰不会使上皮细胞基底部的乳铁蛋白标记消失。在通过手术去除上皮细胞的小鼠的乳腺脂肪垫中也观察到了乳铁蛋白的表达。封闭一个乳头 24 小时会导致基质细胞数量增加和肌上皮细胞标记增加。因此，存在于小鼠乳腺上皮细胞间质空间中的乳铁蛋白部分来源于基质细胞。讨论了乳铁蛋白在乳腺上皮细胞基底侧的可能作用。
