DLK1(PREF1) is a negative regulator of adipogenesis in CD105+/CD90+/CD34+/CD31−/FABP4− adipose-derived stromal cells from subcutaneous abdominal fat pats of adult women

Abstract

The main physiological function of adipose-derived stromal/progenitor cells (ASC) is to differentiate into adipocytes. ASC are most likely localized at perivascular sites in adipose tissues and retain the capacity to differentiate into multiple cell types. Although cell surface markers for ASC have been described, there is no complete consensus on the antigen expression pattern that will precisely define these cells. DLK1(PREF1) is an established marker for mouse adipocyte progenitors which inhibits adipogenesis. This suggests that DLK1(PREF1) could be a useful marker to characterize human ASC. The DLK1(PREF1) status of human ASC is however unknown. In the present study we isolated ASC from the heterogeneous stromal vascular fraction of subcutaneous abdominal fat pats of adult women. These cells were selected by their plastic adherence and expanded to passage 5. The ASC were characterized as relatively homogenous cell population with the capacity to differentiate in vitro into adipocytes, chondrocytes, and osteoblasts and the immunophenotype CD105⁺/CD90⁺/CD34⁺/CD31⁻/FABP4⁻. The ASC were positive for DLK1(PREF1) which was well expressed in proliferating and density arrested cells but downregulated in the course of adipogenic differentiation. To investigate whether DLK1(PREF1) plays a role in the regulation of adipogenesis in these cells RNAi-mediated knockdown experiments were conducted. Knockdown of DLK1(PREF1) in differentiating ASC resulted in a significant increase of the expression of the adipogenic key regulator PPARγ2 and of the terminal adipogenic differentiation marker FABP4. We conclude that DLK1(PREF1) is well expressed in human ASC and acts as a negative regulator of adipogenesis. Moreover, DLK1(PREF1) could be a functional marker contributing to the characterization of human ASC.

Influence of Bovine Serum Lipids and Fetal Bovine Serum on the Expression of Cell Surface Markers in Cultured Bovine Preadipocytes

“…This shows that DLK1 is mostly expressed in proliferating and early developing ADSCs before the final differentiation process commences. Similar results were found in human adipocytes in vitro [Mitterberger et al, 2012]. In the preadipocyte cell line NIH 3T3L1, the production of DLK1 was also highest after induction [Garces et al, 1999].…”

“…With the differentiation of ADSCs towards adipocytes, cells underwent conformational changes in their cytoskeleton to produce cell differentiation products like FabP4 and triglycerides [Mitterberger et al, 2012] with a concomitant decrease or absence of DLK1 expression. This was most prominent in TRT-2, where cells were cultured in the absence of FBS and presence of BSL.…”

Células-tronco mesenquimais: isolamento e caracterização de populações derivadas de alvéolo dental humano e identificação e caracterização de populações de polpas dentais de camundongos

“…Cell Initiative, 2007), células-tronco hematopoiéticas (Bradley et al, 2009;Karaöz et al, 2010;Orbay et al, 2012), assim como em células-tronco mesenquimais dereivadas de tecidos dentais (Horwitz et al, 2005;Dominici et al, 2006;Lorenz et al, 2008;Xu et al, 2009;Pivoriuunas et al, 2010;Iohara et al, 2011;Mitterberger et al, 2012;Orbay et al, 2012;Mafi et al, 2011;Lin et al, 2011;El-Syed et al, 2012;Hidaka et al, 2012;Bakopoulou et al, 2013).…”

“…Diversos autores já utilizaram o CD105 para identificar, isolar ou caracterizar células-tronco mesenquimais de diferentes órgãos (Horwitz et al, 2005;Dominici et al, 2006;Lorenz et al, 2008;Mafi et al, 2011;Mitterberger et al, 2012;Orbay et al, 2012;Xu et al, 2009 e também de tecidos dentais (Miura et al, 2003;Sonoyama et al, 2006Sonoyama et al, , 2008Iohara et al, 2011;Liu et al, 2011;Park et al, 2012Park et al, , 2013 …”

“…Esses marcadores são utilizados para a identificação, isolamento e caracterização de CTMs em variados tecidos de diferentes espécies (Barry et al, 2001;Horwitz et al, 2005;Dominici et al, 2006;Lorenz et al, 2008;Boneberg et al, 2009;Xu et al, 2009;Alt et al, 2011;Iohara et al, 2011;Liu et al, 2011;Mafi et al, 2011;Karamzadeh et al, 2012;Mitterberger et al, 2012;Crisan et al, 2012;El-Sayed et al, 2012;Orbay et al, 2012;Park et al, 2012Park et al, , 2013Wang et al, 2013). No entanto, o marcador Stro-1 apresenta especificidade controversa em tecidos de camundongos e é portanto, evitado nesses animais (Kemoun et al, 2007;Ishikawa et al, 2012;James et al, 2012;Rizk et al, 2013).…”