The influence of fibroblast growth factor 2 on the senescence of human adipose-derived mesenchymal stem cells during long-term culture

Abstract

Adipose‐derived mesenchymal stem cells (ASCs) exhibit great potential in regenerative medicine, and in vitro expansion is frequently necessary to obtain a sufficient number of ASCs for clinical use. Fibroblast growth factor 2 (FGF2) is a common supplement in the ASC culture medium to enhance cell proliferation. To achieve clinical applicability of ASC‐based products, prolonged culture of ASCs is sometimes required to obtain sufficient quantity of ASCs. However, the effect of FGF2 on ASCs during prolonged culture has not been previously determined. In this study, ASCs were subjected to prolonged in vitro culture with or without FGF2. FGF2 maintained the small cell morphology and expedited proliferation kinetics in early ASC passages. After prolonged in vitro expansion, FGF2‐treated ASCs exhibited increased cell size, arrested cell proliferation, and increased cellular senescence relative to the control ASCs. We observed an upregulation of FGFR1c and enhanced expression of downstream STAT3 in the initial passages of FGF2‐treated ASCs. The application of an FGFR1 or STAT3 inhibitor effectively blocked the enhanced proliferation of ASCs induced by FGF2 treatment. FGFR1c upregulation and enhanced STAT3 expression were lost in the later passages of FGF2‐treated ASCs, suggesting that the continuous stimulation of FGF2 becomes ineffective because of the refractory downstream FGFR1 and the STAT3 signaling pathway. In addition, no evidence of tumorigenicity was noted in vitro and in vivo after prolonged expansion of FGF2‐cultured ASCs. Our data indicate that ASCs have evolved a STAT3‐dependent response to continuous FGF2 stimulation which promotes the initial expansion but limits their long‐term proliferation.

Circular RNA circ_001422 promotes the progression and metastasis of osteosarcoma via the miR-195-5p/FGF2/PI3K/Akt axis

“…Evidence indicates that FGF2 is implicated in diverse biological processes, including neurodevelopment, immune homeostasis, angiogenesis and neoplastic transformation [46]. Although the role of FGF2 in malignancies remains controversial, FGF2 has been proposed to act as a pro-oncogenic regulator during the development of OS [47][48][49]. In the present study, abnormally elevated levels of FGF2 mRNA and protein were consistently observed in OS tissues and cells.…”

Circular RNA circ_001422 Promotes Progression and Metastasis of Osteosarcoma via the miR-195-5p/FGF2/PI3K/Akt Axis

“…Evidence indicates that FGF2 is implicated in diverse biological processes, including neurodevelopment, immune homeostasis, angiogenesis and neoplastic transformation [41]. Although the role of FGF2 in malignancies remains controversial, FGF2 has been proposed as a pro-oncogenic regulator during the development of OS [42][43][44]. In the present study, abnormally elevated levels of FGF2 mRNA and protein were consistently observed in OS tissues and cells.…”

A Shaking-Culture Method for Generating Bone Marrow Derived Mesenchymal Stromal/Stem Cell-Spheroids With Enhanced Multipotency in vitro

“…However, a critical issue associated with the use of BM-MSCs is that, under adherent monolayer culture conditions, these cells eventually lose their stemness properties following repeated passages during culture expansion (Bonab et al, 2006;Stolzing et al, 2006;Wagner et al, 2008;Bork et al, 2010;Gu et al, 2016). It has been suggested that supplementing the culture medium with fibroblast growth factor (FGF)-2 (Tsutsumi et al, 2001;Cheng et al, 2020;Xu et al, 2020) and epidermal growth factor (EGF) (Tamama et al, 2006;Xu et al, 2020) can enable large-scale expansion of MSC cultures. However, these methods are limited as such supplements cannot sufficiently maintain the cellular differentiation potential in longterm culture (Gharibi and Hughes, 2012;Cheng et al, 2020).…”

“…It has been suggested that supplementing the culture medium with fibroblast growth factor (FGF)-2 (Tsutsumi et al, 2001;Cheng et al, 2020;Xu et al, 2020) and epidermal growth factor (EGF) (Tamama et al, 2006;Xu et al, 2020) can enable large-scale expansion of MSC cultures. However, these methods are limited as such supplements cannot sufficiently maintain the cellular differentiation potential in longterm culture (Gharibi and Hughes, 2012;Cheng et al, 2020).…”