ABSTRACT
Organoids are tissue structures, generated from pluripotent stem cells and cultured in vitro, which form self-organize and recapitulate tissues with similar structure and function to the original organs. Organoids have similar appearance and function to the original tissues, and have been widely applied in basic research and clinical trial. At present, the organoids of liver, kidney, islet, brain, intestine and other organs have been successfully cultivated. The use of islet organoid is a hotspot in the field of organoid research. However, islet organoid is currently applied in basic research because rejection after organ transplantation and other issues remain unresolved. In this article, the origin, development and basic application of islet organoid were reviewed, aiming to provide reference for the transformation from basic research of islet organoid into clinical application as well as the treatment of diabetes mellitus.
ABSTRACT
Parkinson disease(PD) is a degenerative disorder characterized by the loss of midbrain dopamine (DA) neurons. Recently it has been demonstrated that ES cells can differentiate into dopaminergic neurons in vitro and is a potentiol item for transplantation. In this paper we reviewed clinical study in treating Parkinson disease、methods and mechanisms of ES cells differentiation into dopaminergic neurons in vitro and progress of its application.
ABSTRACT
Objective To clarify whether the intravenous administration of embryonic stem cells(ESCs)could home in on injured myocardium caused by acute myocardial infarction(MI)in rats and to improve the cardiac function afterwards,and to explore the possible effect of inflammatory factor TNF-?on it.Methods ESCs were cultured in vitro and transfected with green fluorescence protein(GFP).The model of heart failure post MI in rats was established by permanent ligation of left coronary anterior descend artery.After operation the rats were administered with 10~7 ESC via tail vein every other day for 6 days.The sham and MI without ESCs infusion groups served as control.Six weeks later,the hemodynamic measurement was employed to evaluate the cardiac function.Immunohistochemistry assay was used to detect the GFP expression in heart and other organs,and the cardiac specific protein Tropinin I(Tn I)expression in GFP positive spot of heart.Meanwhile,the co-culture in vitro of ESC and neonatal rat cardiomyocytes was used to observe the effect of overexpression of TNF-?in cardiomyocytes on ESC migration.Results Six weeks after MI,cardiac function was significantly improved in rats administered with ESC in comparison with those of MI group.Histological changes demonstrated that infused ESCs formed GFP-positive grafts in infracted myocardium.Alternatively,the positive immunostaining for Tn I was found in the area corresponding to GRP positive staining.In regard to other organs,only in spleen a few GFP positive cells were found.This would indicate that circulating ESC could translocate to infracted myocardium and to form cardiac tissue.Migration assay of ESC in vitro indicated that cultured cardiomyocytes with overexpression of TNF-aobviously enhanced the migration of ESCs in comparison with cardiomyocytes without transfection. Conclusion Intravenously infused ESC could home in on infarcted myocurdium and futher differentiate into cardiomyocytes which led to the improvement of cardiac function.In the setting of acute MI the homing mechanism Could be associated with locally released inflammatory factors such as TNF-?which may play as a chemotactic agent on circulating ESC.
ABSTRACT
Objective To explore the optimal condition of direct differentiation into dopaminergic neurons of embryonic stem cells in serum-free and feeder layer cell free medium. Methods We used the method of phase induction to culture embryonic stem cells. At first, embryonic stem cells were cultured in the serum-free medium with bFGF and LIF so as to realize the direct differentiation from embryonic stem cells to neural precursors. Differentiated cells were determined by nestin immunocytochemical staining. On this basis, we transferred embryonic stem cells to the B27 serum-free medium with IL-1 so as to realize the direct differentiation from neural precursors to dopaminergic neurons. Differentiated cells were determined by TH immunocytochemical staining. Results Approximately 85 percent of cell masses were nestin immuno-positive. The differentiation ratio of dopaminergic neurons was 13%, which increased significantly in comparison with natural differentiation ratio of dopaminergic neurons.Conclusion Without serum and feeder layer cell, we can induce embryonic stem cells to differentiate into dopaminergic neurons effectively by adding different growth factors at different phases, which makes the inductive processes more easily.