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Int J Mol Sci ; 22(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918735


Stem cells secrete paracrine factors including extracellular vesicles (EVs) which can mediate cellular communication and support the regeneration of injured tissues. Reduced oxygen (hypoxia) as a key regulator in development and regeneration may influence cellular communication via EVs. We asked whether hypoxic conditioning during human induced pluripotent stem cell (iPSC) culture effects their EV quantity, quality or EV-based angiogenic potential. We produced iPSC-EVs from large-scale culture-conditioned media at 1%, 5% and 18% air oxygen using tangential flow filtration (TFF), with or without subsequent concentration by ultracentrifugation (TUCF). EVs were quantified by tunable resistive pulse sensing (TRPS), characterized according to MISEV2018 guidelines, and analyzed for angiogenic potential. We observed superior EV recovery by TFF compared to TUCF. We confirmed hypoxia efficacy by HIF-1α stabilization and pimonidazole hypoxyprobe. EV quantity did not differ significantly at different oxygen conditions. Significantly elevated angiogenic potential was observed for iPSC-EVs derived from 1% oxygen culture by TFF or TUCF as compared to EVs obtained at higher oxygen or the corresponding EV-depleted soluble factor fractions. Data thus demonstrate that cell-culture oxygen conditions and mode of EV preparation affect iPSC-EV function. We conclude that selecting appropriate protocols will further improve production of particularly potent iPSC-EV-based therapeutics.

Vesículas Extracelulares/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Neovascularização Fisiológica , Transporte Biológico , Biomarcadores , Hipóxia Celular , Autorrenovação Celular , Células Cultivadas , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Medicina Regenerativa/métodos
Life Sci ; 92(2): 101-7, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23178150


Tumor angiogenesis and lymphangiogenesis are key features of tumor progression and metastasis. The role of tumor cells-derived factors in the promotion of associated angiogenesis and lymphangiogenesis is much studied and, no doubt, very important for the understanding of cancer progression. This review aims to present and discuss the work done on the pro-angiogenic and lymphangiogenic cellular interactions within the tumor microenvironment and the signaling pathways that regulate this crosstalk. Such multifactor studies are critical for the development of future therapeutic approaches for cancer because they take into account the complexities of cellular interactions within the tumor microenvironment.

Linfangiogênese/fisiologia , Neoplasias/irrigação sanguínea , Neovascularização Patológica/fisiopatologia , Transdução de Sinais/fisiologia , Animais , Comunicação Celular/fisiologia , Endotélio Linfático/fisiopatologia , Endotélio Vascular/fisiopatologia , Fibroblastos/fisiologia , Humanos , Macrófagos/fisiologia , Neoplasias/fisiopatologia