RESUMO
Human induced pluripotent stem cells (hiPSCs) show great promise for obesity treatment as they represent an unlimited source of brown/brite adipose progenitors (BAPs). However, hiPSC-BAPs display a low adipogenic capacity compared to adult-BAPs when maintained in a traditional adipogenic cocktail. The reasons of this feature are unknown and hamper their use both in cell-based therapy and basic research. Here we show that treatment with TGFß pathway inhibitor SB431542 together with ascorbic acid and EGF were required to promote hiPSCs-BAP differentiation at a level similar to adult-BAP differentiation. hiPSC-BAPs expressed the molecular identity of adult-UCP1 expressing cells (PAX3, CIDEA, DIO2) with both brown (ZIC1) and brite (CD137) adipocyte markers. Altogether, these data highlighted the critical role of TGFß pathway in switching off hiPSC-brown adipogenesis and revealed novel factors to unlock their differentiation. As hiPSC-BAPs display similarities with adult-BAPs, it opens new opportunities to develop alternative strategies to counteract obesity.
Assuntos
Adipócitos Marrons/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Transdução de Sinais/genética , Fator de Crescimento Transformador beta/antagonistas & inibidores , Adipócitos Marrons/citologia , Adipócitos Marrons/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Ácido Ascórbico/farmacologia , Benzamidas/farmacologia , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Dioxóis/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Fator de Transcrição PAX3/genética , Fator de Transcrição PAX3/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Iodotironina Desiodinase Tipo IIRESUMO
Human adipose-derived stem cell populations express cell surface markers such as CD105, CD73, CD146 and CD140a/PDFGRα. However, it was unclear whether these markers could discriminate subpopulations of undifferentiated cells and whether the expression of these markers is modulated during differentiation. To address this issue, we analysed the immunophenotype of cultured human multipotent adipose derived stem (hMADS) cell populations at different adipocyte differentiation steps. We found that 100% of undifferentiated cells expressed CD73 and CD105. In contrast, CD146 and CD140a/PDFGRα marked two different subpopulations of cells. CD140a/PDGFRα subpopulation was regulated by FGF2, a critical factor of human adipose-derived stem cell self-renewal. During differentiation, CD73 was maintained and marked lipid-laden cells, whereas CD105 expression was inhibited in fully differentiated cells. The percentage of CD146 and CD140a/PDFGRα-positive cells declined as soon as cells had undergone differentiation. Altogether, these data support the notion that expanded adipose-derived stem cells are heterogeneous mixtures of cells and cell surface markers studied can discriminate subpopulations.