Putative stem cells have been isolated from various tissue fluids such as synovial fluid, amniotic fluid, menstrual blood, etc. Recently the presence of nestin positive putative mammary stem cells has been reported in human breast milk. However, it is not clear whether they demonstrate multipotent nature. Since human breast milk is a non-invasive source of mammary stem cells, we were interested in examining the nature of these stem cells. In this pursuit, we could succeed in isolating and expanding a mesenchymal stem cell-like population from human breast milk. These cultured cells were examined by immunofluorescent labeling and found positive for mesenchymal stem cell surface markers CD44, CD29, SCA-1 and negative for CD33, CD34, CD45, CD73 confirming their identity as mesenchymal stem cells. Cytoskeletal protein marker analysis revealed that these cells expressed mesenchymal stem cells markers, namely, nestin, vimentin, smooth muscle actin and also manifests presence of E-Cadherin, an epithelial to mesenchymal transition marker in their early passages. Further we tested the multipotent differentiation potential of these cells and found that they can differentiate into adipogenic, chondrogenic and oesteogenic lineage under the influence of specific differentiation cocktails. This means that these mesenchymal stem cells isolated from human breast milk could potentially be “reprogrammed” to form many types of human tissues. The presence of multipotent stem cells in human milk suggests that breast milk could be an alternative source of stem cells for autologous stem cell therapy although the significance of these cells needs to be determined.

中文翻译：

---

人类母乳是多能间充质干细胞的丰富来源。

推定的干细胞已经从各种组织液中分离出来，例如滑液、羊水、月经血等。最近有报道称在人类母乳中存在巢蛋白阳性推定的乳腺干细胞。然而，尚不清楚它们是否表现出多能性。由于人类母乳是乳腺干细胞的非侵入性来源，我们有兴趣研究这些干细胞的性质。在这一追求中，我们可以成功地从人类母乳中分离和扩大间充质干细胞样群体。通过免疫荧光标记检查这些培养的​​细胞，发现间充质干细胞表面标志物 CD44、CD29、SCA-1 呈阳性，而 CD33、CD34、CD45、CD73 呈阴性，证实它们是间充质干细胞。细胞骨架蛋白标志物分析显示，这些细胞表达间充质干细胞标志物，即巢蛋白、波形蛋白、平滑肌肌动蛋白，并且还表现出 E-钙粘蛋白的存在，这是一种在其早期传代中的上皮至间充质转化标志物。此外，我们测试了这些细胞的多能分化潜能，发现它们可以在特定分化混合物的影响下分化为成脂、成软骨和成骨谱系。这意味着从人类母乳中分离出的这些间充质干细胞有可能被“重新编程”以形成多种类型的人体组织。