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
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • 2024-04

    • We identified a number of CD markers that are expressed

    2018-11-08

    We identified a number of CD markers that are expressed in both osteoprogenitor and adipoprogenitor Etonogestrel and thus can be employed as core markers of the BMSCs phenotype. Our data corroborate previous studies that employed alternative technologies to identify markers for multipotent BMSCs. Comparing gene expression and FACS analysis of osteoprogenitor and adipoprogenitor cells, we have identified CD markers that are exclusively associated with either the osteoblastic or adipocytic phenotype. The adipocytic phenotype-associated CD markers included CD53, CD80, CD141, CD134 and CD212. Only CD141 has previously been demonstrated to be expressed in human adipose tissue (Ryynanen et al., 2014). On the other hand, osteoblastic phenotype-associated CD marker included CD54, CD34, CD200, CD132 and CD227. Among these, CD54, CD73, CD34 and CD200 markers have previously been reported to be expressed in osteoblasts (Reyes-Botella et al., 2000; Takedachi et al., 2012; Ode et al., 2013; Delorme et al., 2008). Reyes-Botella et al. reported the expression of CD54 in cultured human osteoblasts isolated from normal mandibular bone. Human osteoblasts express CD73 and human periosteal osteoblasts stain positively for CD73 (Ode et al., 2013). Cell sorting of CD34+/CD38+ cells from human BMSCs identify an osteoprogenitors that has the ability to differentiate into functional osteoblasts in culture (Chen et al., 1997). Additionally, CD200+ cells loaded on biphasic calcium phosphate (MBCP) ceramic disks and implanted subcutaneously in nude mice, showed higher ability for bone formation compared with unsorted cells (Delorme et al., 2008). The biological role of CD132 and CD227 markers are not known. We have identified CD34 as a potential marker for murine osteoprogenitor cells. CD34 is a cell surface glycoprotein that functions as an adhesion molecule and is commonly expressed on early hematopoietic stem cells (HSC) and their progeny as well as vascular endothelial cells (Krause et al., 1996; Muller et al., 2002). CD34 expression has been detected in a subset of human bone marrow stromal cells (Simmons and Torok-Storb, 1991; Peister et al., 2004), human placental stromal cells (Garcia-Pacheco et al., 2001) and human adipose tissue derived stromal cells (ADSCs) (Mitchell et al., 2006). Interestingly, cultured human BMSCs were considered negative for CD34 expression by the International Society for Cellular Therapy (Dominici et al., 2006). However, several lines of evidence suggest that CD34 defines a sub-population of BMSCs. First, studies that reported negative expression of CD34 in BMSCs examined cultured BMSCs on plastic surfaces (Lin et al., 2012) which may explain the loss of CD34 expression as it has been reported in cultured expanded BMSCs from human bone marrow (Kaiser et al., 2007), adipose tissue (Planat-Benard et al., 2004) and thymus (Mouiseddine et al., 2008). Second, sorted CD34+ from freshly isolated human bone marrow showed high frequency for colony-forming unit-fibroblast (CFU-F) formation which is a functional marker of multipotent BMSCs (Kaiser et al., 2007). Third, the development of Stro-1 antibody that identifies multipotent human BMSCs, was developed based on immunization with human CD34+ BMSC fraction (Simmons and Torok-Storb, 1991; Ning et al., 2011). Finally, our own data presented in the current manuscript demonstrate that CD34+ is enriched in committed osteoprogenitors. Previous studies and our own demonstrate that CD34 expression is rapidly down regulated in cultured BMSCs and thus it is more suitable for isolating osteoprogenitors from freshly isolated bone marrow mononuclear cells (Sato et al., 1999; Zanjani et al., 1998; Cao et al., 2005). Comparing CD markers expression between CD34+ and CD34− mBMSCs revealed similar pattern of expression of CD markers known to be expressed by BMSCs. Interestingly, CD146 was enriched in CD34+ cells. CD146 has been identified as a stemness marker for isolating human BMSCs with high osteogenic capacity in vitro and in vivo (Sorrentino et al., 2008; Sacchetti et al., 2007; Ulrich et al., 2015). We have previously shown that CD146 is enriched in hBMSCs clones with high bone forming capacity (Larsen et al., 2010). Interestingly, CD146 failed to isolate cells with the BMSCs phenotype (Chou et al., 2012). Thus, our data suggest CD146 expression is not sufficient to identify murine BMSCs, but it can be employed as an additional CD marker, in combination with CD34 to isolate bone marrow osteoprogenitors.