Cell interactions in an adult mesenchymal stem cell niche

间充质干细胞（Mesenchymal stem cells，MSCs）是指来源于间充质的不能分化为不同类型细胞的干细胞。这些细胞包括骨细胞、软骨细胞、脂肪细胞和许多其他细胞。MSC存在于几种成人组织中，最值得注意的是骨髓。除了它们的干细胞特性之外，MSC还具有良好的抑制免疫系统的能力。因此，MSC是用于组织修复和免疫抑制的临床应用的非常重要的细胞来源，并且在美国正在进行几项大型临床试验。骨髓间充质干细胞的问题是，大多数研究都是在骨髓上进行的，骨髓是一种难以研究的组织，临床应用的骨髓间充质干细胞的主要来源是骨髓或脂肪组织。为了了解更多的这些细胞，使它们在临床应用中的使用可以得到改善，需要研究更容易获得的细胞来源。MSC也存在于牙齿中，特别是在牙齿中心的牙髓组织中，它们参与损伤后的牙齿修复。自然脱落儿童牙髓细胞的商业银行？牙齿是可用的。然而，与骨髓间充质干细胞一样，这些细胞难以研究，因为它们的数量非常少。与我们不同的是，小鼠的牙齿（门牙）不断生长，因为它们有一群MSC，不断提供新的细胞。我们已经确定了这些细胞的位置，可以很容易地看到这些细胞。这意味着我们现在有大量易于获得的MSC，可以详细研究它们的特性以及它们如何作为干细胞维持。这些信息将大大有助于了解其他MSC，并改善这些细胞在临床治疗中的使用。

Mesenchymal stem cells (MSCs) are stem cells that cant form different types of cells derived from mesenchyme. These include bone cells, cartilage cells, fat cells and many others. MSCs are found in several adult tissues, most notably the bone marrow. In addition to their stem cell properties, MSCs also have a well-established ability to repress the immune system. MSCs are thus a very important source of cells for clinical applications in tissue repair and in immune suppression and several large clinical trials are underway in the US. The problem with MSCs is that most research has been carried out on the bone marrow, a difficult tissue to study and the main source of MSCs for clinical applications is the bone marrow or fat tissue. In order understand more of these cells so that they use in clinical applications can be improved, a more accessible source of cells needs to be studied. MSCs are also found in teeth, particularly in the pulp tissue in the centre of the tooth where they are involved in tooth repair following damage. Commercial banking of tooth pulp cells from naturally lost children?s teeth is available. However in common with bone marrow MSCs these cells are difficult to study since they are present in very small numbers. Unlike us, mice have teeth (incisors) that grow continuously because they have a population of MSCs that continuously provide new cells. We have identified the location of these cells and can visualise the cells easily. This means we now have a large population of easily accessible MSCs that can be studied in detail to understand their properties and how they are maintained as stem cells. This information will greatly benefit the understanding of other MSCs and improve the use of these cells in clinical treatments.