Neuronal differentiation of tonsil-derived mesenchymal stem cells (TMSCs) is investigated in a 3D hybrid system. The hybrid system is prepared by increasing the temperature of poly(ethylene glycol)-poly(l-alanine) aqueous solution to 37 °C through the heat-induced sol-to-gel transition, in which TMSCs and growth factor releasing microspheres are suspended. The in situ formed gel exhibits a modulus of 800 Pa at 37 °C, similar to that of brain tissue, and it is robust enough to hold the microspheres and cells during the 3D culture of TMSCs. The neuronal growth factors are released over 12-18 d, and the TMSCs in a spherical shape initially undergo multipolar elongation during the 3D culture. Significantly higher expressions of the neuronal biomarkers such as nuclear receptor related protein (Nurr-1), neuron specific enolase, microtubule associated protein-2, neurofilament-M, and glial fibrillary acidic protein are observed in both mRNA level and protein level in the hybrid systems than in the control experiments. This study proves the significance of a controlled drug delivery concept in tissue engineering or regenerative medicine, and a 3D hybrid system with controlled release of growth factors from microspheres in a thermogel can be a very promising tool.
BackgroundVascular endothelial growth factor A (VEGFA), a critical mediator of tumor angiogenesis, is a well-characterized target of hypoxia-inducible factor 1 (HIF-1). Murine arrest-defective protein 1A (mARD1A225) acetylates HIF-1α, triggering its degradation, and thus may play a role in decreased expression of VEGFA.MethodsWe generated ApcMin/+/mARD1A225 transgenic mice and quantified growth of intestinal polyps. Human gastric MKN74 and murine melanoma B16F10 cells overexpressing mARD1A225 were injected into mice, and tumor growth and metastasis were measured. VEGFA expression and microvessel density in tumors were assessed using immunohistochemistry. To evaluate the role of mARD1A225 acetylation of Lys532 in HIF-1α, we injected B16F10-mARD1A225 cell lines stably expressing mutant HIF-1α/K532R into mice and measured metastasis. All statistical tests were two-sided, and P values less than .05 were considered statistically significant.ResultsApcMin/+/mARD1A225 transgenic mice (n = 25) had statistically significantly fewer intestinal polyps than ApcMin/+ mice (n = 21) (number of intestinal polyps per mouse: ApcMin/+ mice vs ApcMin/+/mARD1A225 transgenic mice, mean = 83.4 vs 38.0 polyps, difference = 45.4 polyps, 95% confidence interval [CI] = 41.8 to 48.6; P < .001). The growth and metastases of transplanted tumors were also statistically significantly reduced in mice injected with mARD1A225-overexpressing cells than in mice injected with control cells (P < .01). Moreover, overexpression of mARD1A225 decreased VEGFA expression and microvessel density in tumor xenografts (P < .04) and ApcMin/+ intestinal polyps (P = .001). Mutation of lysine 532 of HIF-1α in B16F10-mARD1A225 cells prevented HIF-1α degradation and inhibited the antimetastatic effect of mARD1A225 (P < .001).ConclusionmARD1A225 may be a novel upstream target that blocks VEGFA expression and tumor-related angiogenesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.