Low Doses of Bone Morphogenetic Protein 4 Increase the Survival of Human Adipose-Derived Stem Cells Maintaining Their Stemness and Multipotency

Abstract

Mesenchymal stem cells (MSCs) have emerged as important tools for cell therapy; therefore, identification of factors capable of governing their ex vivo expansion become essential. In this study we demonstrate that human adipose-derived stem cells (ASCs) express all components of the bone morphogenetic protein (BMP)/BMP receptor signaling pathway and respond to BMP4 inducing upregulated expression of its specific target genes Id1-Id4. Moreover, ASCs grown in a medium reduced in serum produce endogenous BMP4 that could affect autocrinely ASC growth. On the contrary, dorsomorphin, an inhibitor of BMP signaling pathway, decreases cell numbers yielded from ASC cultures in correlation with increased apoptosis and decreased cycling cells. Therefore, BMP4 emerges as a possible factor for ex vivo expanding human ASCs. Our results demonstrate that, as other morphogens, BMP4 effects on human MSCs are dose dependent. High doses significantly increased apoptosis and drastically reduced cell proliferation, whereas low doses of BMP4 (0.01-0.1 ng/mL) significantly increase culture cell content, reduce the number of apoptotic cells, and increase that of cycling cells. Further, treatment of human ASCs with low doses of BMP4 does not modify expression of Nanog and Oct4, two transcription factors involved in self-renewal and pluripotency of stem cells or avoid their osteogenic or osteoblastic differentiation capacities when cultured in adequate inducing media, as shown by the induction of specific gene expression (CEBP, PPARγ, and RUNX2). Our results therefore support BMP4 as a promising factor for expanding human adipose tissue-derived MSCs maintaining their properties of stemness and multipotency.

Pericyte‐derived bone morphogenetic protein 4 underlies white matter damage after chronic hypoperfusion

“…This finding was inconsistent with other studies that demonstrated no effect 16, 57 or even a positive effect 43 of BMP4 on OPC proliferation. However, recent studies have suggested that the effects of BMP4 on stem cell proliferation are dose‐dependent; low dose BMP4 increases proliferation, but high dose BMP4 decreases proliferation of mesenchymal stem cells 53 or primordial germ cells 31. Considering that OPC proliferation is also affected by many factors, BMP4 may have dose‐dependent and opposite effects on OPC proliferation.…”

Revisiting the Advances in Isolation, Characterization and Secretome of Adipose-Derived Stromal/Stem Cells

“…BMP-2, BMP-6, and BMP-14 are considered as major factors in osteogenic differentiation of ASCs s [148,149]; whereas, BMP-7 promotes both chondrogenesis as well as osteogenesis [150]. The osteogenic potential of ASCs is affected by the concentration of BMP and nature of differentiation medium [151,152,153]. A notable osteogenesis promoting effect of combined retinoic acid and BMP2 in murine ASCs have also been evidenced [154].…”

Adipose-derived mesenchymal stromal/stem cells: An update on their phenotype in vivo and in vitro

“…The usage of low-serum containing culture media supplemented with recombinant growth factors [e.g., epidermal growth factor, plateletderived growth factor and/or basic fibroblast growth factor] has been described [79][80][81][82] . Low doses of bone morphogenic protein 4 have also been shown to stimulate ASC proliferation [83] . Nevertheless, the gold standard for culturing ASCs will be a medium absolutely free from animal serum or factors, with well-known ingredients [7] .…”