Neurogenic transdifferentiation of human adipose-derived stem cells? A critical protocol reevaluation with special emphasis on cell proliferation and cell cycle alterations

Abstract

Adipose-derived stem cells (ASCs) are reported to display multilineage differentiation potential, including neuroectodermal pathways. The aim of the present study was to critically re-evaluate the potential neurogenic (trans-)differentiation capacity of ASCs using a neurogenic induction protocol based on the combination of isobutylmethylxanthine (IBMX), indomethacin and insulin. ASCs isolated from lipo-aspirate samples of five healthy female donors were characterized and potential neurogenic (trans-)differentiation was assessed by means of immunohistochemistry and gene expression analyses. Cell proliferation and cell cycle alterations were studied, and the expression of CREB/ATF transcription factors was analyzed. ASCs expressed CD59, CD90 and CD105, and were tested negative for CD34 and CD45. Under neurogenic induction, ASCs adopted a characteristic morphology comparable to neur(on)al progenitors and expressed musashi1, β-III-tubulin and nestin. Gene expression analyses revealed an increased expression of β-III-tubulin, GFAP, vimentin and BDNF, as well as SOX4 in induced ASCs. Cell proliferation was significantly reduced under neurogenic induction; cell cycle analyses showed a G2-cell cycle arrest accompanied by differential expression of key regulators of cell cycle progression. Differential expression of CREB/ATF transcription factors could be observed on neurogenic induction, pointing to a decisive role of the cAMP-CREB/ATF system. Our findings may point to a potential neurogenic (trans-)differentiation of ASCs into early neur(on)al progenitors, but do not present definite evidence for it. Especially, the adoption of a neural progenitor cell-like morphology must not automatically be misinterpreted as a specific characteristic of a respective (trans-)differentiation process, as this may as well be caused by alterations of cell cycle progression.

Epigenetic Regulation of Nestin Expression During Neurogenic Differentiation of Adipose Tissue Stem Cells

“…On the basis of morphological and immunohistochemical criteria, a number of studies have reported a neurogenic differentiation of ASCs [4,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Electrophysiological recordings from neuron-like cells derived from ASCs support the idea that these have differentiated into functional neurons [10,[15][16][17].…”

Effects of selegiline, a monoamine oxidase B inhibitor, on differentiation of P19 embryonal carcinoma stem cells, into neuron-like cells

“…The β-III tubulin is a classic marker for differentiating neurons (Rak et al 2011). Expression of brain-specific III tubulin in stem cell-derived neurons has been shown in previous studies (Falconer et al 1992;Kompisch et al 2010).…”

Transplantation of Adipose-Derived Stem Cells in Stroke

“…Despite the relatively small number of ADSC to explain the overall functional recovery in the reported studies, their presence signifies "transdifferentitation" as a possible mechanism underlying the positive therapeutic impact (Gutierrez-Fernandez et al 2013a). Indeed, the capacity of neural differentiation for ADSC has been extensively investigated (Cardozo et al 2010;Kompisch et al 2010;Liao et al 2010;Qian et al 2010;Abdanipour et al 2011;Yu et al 2011;Ahmadi et al 2012). It has also been reported that, compared with bone marrow-derived mesenchymal stem cells, ADSC have superior neurogenic potential (Kang et al 2004).…”

“…A study investigating the fate of human ADSC from different human donors after being subcutaneously injected into immunodeficient SCID mice showed that the cells survived for at least 17 months with subsequent differentiation into fibroblasts of the subdermic connective tissue and into mature adipocytes of fat tissue, exclusively at the site of injection without evidence of migration or fusion with host cells (Lopez-Iglesias et al 2011), underscoring the safety of ADSC transplantation. Moreover, the use of terminally differentiated ADSC may be a possible option for minimizing the risk especially when the protocols for in vitro transdifferentiation of ADSC into neuronal lineage have been well-documented (Cardozo et al 2010;Kompisch et al 2010;Liao et al 2010;Qian et al 2010;Abdanipour et al 2011;Yu et al 2011;Ahmadi et al 2012). Indeed, the use of induced ADSC has been endorsed as a promising therapeutic option in stroke treatment (Yang et al 2011;Shen et al 2013).…”