Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • 2024-04

    • Human mesenchymal stem cells hMSCs

    2018-10-22

    Human mesenchymal stem raas inhibitor (hMSCs) are isolated firstly from bone marrow (BM) (Friedenstein et al., 1976; Caplan, 1991) and isolated subsequently from other tissues such as adipose tissue, umbilical cord cutaneous tissue, fetal liver and pulmonary tissue (Rodriguez et al., 2005; Romanov et al., 2003; Campagnoli et al., 2001). Placental tissue originates during the first stages of embryological development. It is possible that this tissue may contain some cells with the plasticity of the early embryonic cells. Meanwhile, placental tissue is fundamental for maintaining fetomaternal tolerance during pregnancy. It implies that some cells in placental tissue should have immunomodulatory characteristics. These key points make some cells from placenta as good candidates in the cell therapy. In addition, placenta is abundantly available and can provide an ethically uncontroversial and easily accessible source of cells for experimental and clinical application (Zhang et al., 2004). Previous studies showed that multi-lineage mesenchymal stem cells could be isolated from human term placenta using the direct attachment method (Fukuchi et al., 2004; Igura et al., 2004; Miao et al., 2006). Adipogenic and osteogenic differentiation of placenta-derived MSCs have been achieved under the appropriate conditions (Yen et al., 2005). In addition, hMSCs from placental tissue have been recently prospectively identified and purified as vascular pericytes (Crisan et al., 2008). However, the attachable cells isolated using the direct attachment methods in our lab consisted usually of MSC-like cells and other fibroblast-like cells. Three kinds of principal cell types, defined as amniotic epithelial cells (AEC), amniotic mesenchymal stromal cells (AMSC) and chorionic trophoblastic cells (CTC), can be isolated from the fetal membranes of term placenta, and all of these cells have the adhesion property (Parolini et al., 2008). Therefore, it is necessary to use an efficient technique to isolate placenta-derived mesenchymal stem cells (PMSCs). This technique should be effective enough to get rid of other fibroblast-like cells. In recent years, a preplate culture method was used to isolate MSC-like cells from solid tissues such as skeletal muscle (Gharaibeh et al., 2008; Clause et al., 2010; Ji et al., 2010; Sharifiaghdas et al., 2011). This technique is used to select cells after serial adherences, based on their special adherence ability to plastic. In the present study, we modified the preplate culture method as the time-gradient attachment method to isolate PMSCs from placenta (see Materials and methods). The isolation of PMSCs from placenta with this method is based on the difference of adhesion ability between different cells. We analyzed the biological characteristics of these PMSCs isolated using the time-gradient attachment method, and transplanted these cells into the calvarium of rat to repair the calvarial defect. Finally, the immunomodulatory characteristics and reconstruction function of PMSCs isolated using the time-gradient attachment method were discussed.
    Results
    Discussion MSCs have been shown to have low immunogenicity and to modulate immunological responses via T-cell suppression (Rondelli et al., 1996; Haynesworth et al., 1992). We assessed the immunogenicity of placenta-derived cells isolated using both attachment methods through analysis of immunological-relevant cell surface molecules. The analysis of gene expression by RT-PCR method showed HLA-ABC and HLA-DR gene fragments detected in the cells isolated using the direct attachment method. However, no HLA-DR gene fragment was detected in the cells isolated using the time-gradient attachment for 72h. Analysis of flow cytometry confirmed that cells isolated using the time-gradient attachment for 72h do not express HLA-DR but HLA-ABC. The one-way MLR assay was performed to evaluate the ability of immunomodulation. The results showed that cells isolated using time-gradient attachment for 72h could inhibit the proliferation of the T-lymphocytes, but the cells isolated using the direct attachment promoted a proliferative response of T lymphocytes. Therefore, it indicated that the cells isolated using time-gradient attachment for 72h should be a promising candidate for allogenic transplantation due to their low immunogenicity and immunomodulation function.