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
Objective To investigate whether the overexpression of neurogenin 3 ( Ngn3 ) can promote the induced differentiation of human umbilical cord mesenchymal stem cells ( HUCMSCs) into insulin-producing cells (IPGs). Methods HUCMSCs were isolated and cultured, identified by flow cytometry, and the differentiation potential was identified by adipogenesis and osteogenesis induction. HUCMSCs were induced into IPCs in different stages, including a low glucose induction stage and a high glucose induction stage. The experiment was divided into two groups, the control group was induced by the above scheme, while the experimental group was additionally infected the lentivirus overexpression vector carrying the target gene Ngn3 on the 6th day of the same induction process. After induction, the changes of cell structure were observed by electron microscope ; mRNA and protein was collected and Real-time PCR and Western blotting were used to compare the expressions of insulin and musculoaponeurotic fibrosarcoma oncogene homolog A Mafa in the two groups ; medium supernatant was collected and C-peptide content was determined by ELISA. Results HUCMSCs were successfully isolated with positive expression of CD 105 and CD90 and negative expression of CD34 and CD45, which had adipogenic and osteogenic differentiation ability. Then, HUCMSCs were induced into IPCs by stage induction, and the cells expressed Mafa and insulin positively. Ngn3 was overexpressed in the experimental group during the induction. After induction, electron microscopy showed that the cell structure was more mature in the experimental group. The expression levels of insulin and Mafa in the experimental group were significantly higher than those in the control group. During the induction process, the amount of C-peptide secreted by the experimental group was higher than that of the control group. Conclusion Lentivirus-mediated Ngn3 overexpression improves the differentiation efficiency of HUCMSCs into IPCs.
ABSTRACT
Objective@#Glucagon-like peptide-1(GLP-1) and gastrin synergistically promote the differentiation of insulin-producing cells which differentiated from rat bone marrow mesenchymal stem cells (BMSCs).@*Methods@#(1)Prepare IPCs model: pancreatic duodenal homeobox 1 (Pdx-1), neurogenin 3 (Ngn3) combined with V-type tendon fibrosarcoma oncogene homolog A (MafA) co-transfected BMSCs differentiation into IPCs; (2)IPCs were divided into 4 groups: Group A(uninduced group), group B(GLP-1 induction group), group C(gastrin induction group), and group D(GLP-1 combined with gastrin induction group). Cultured in high glucose medium for 7 days, the expression levels of insulin2, Pdx-1, GK, nestin, and glucagon mRNA were detected by RT-PCR. The insulin secretion of each group was detected by ELISA.@*Results@#After cultured for 7 days under high glucose conditions, the morphology of IPCs in each induction group changed significantly, gradually aggregated and formed scattered cell masses, and the combined induction group formed large cell masses. The staining of disulfide brown was reddish brown; The levels of insulin secretion increased gradually on the 0, 3rd, 5th, 7th, and 9th day after induction, and the increase was the most significant in the combined induction group (P<0.05). Compared with group A, the expression of insulin2 and GK in group B and D was significantly up-regulated, the expression of glucagon was down-regulated in group D, the expression of Pdx-1 was down-regulated in group C, and the expression of glucagon was up-regulated (P<0.05). Compared with group B, The expression of insulin2 was down-regulated in group C, and the expression level of glucagon was up-regulated. The expression levels of Pdx-1 and Insulin2 were significantly up-regulated in group D, and the expression level of glucagon was down-regulated (P<0.05). Compared with group C, the expression level of Pdx-1, insulin2 and GK was significantly up-regulated in group D, and the expression level of glucagon was down-regulated (P<0.05).@*Conclusion@#GLP-1 and gastrin synergistically promote the differentiation of IPCs into islet β cells by up-regulating GK and insulin2 and down-regulating glucagon.
ABSTRACT
The 13 nm gold nanoparticles ( AuNPs ) were synthesized through the reduction of HAuCl4 by sodium citrate and the glutathione was assembled on the AuNPs. Under the experiment conditions, glutathione-modified AuNPs ( GSH-AuNPs ) with negative charge presented a wine red color owing to the electrostatic repulsion between nanoparticals. Upon the addition of neurogenin 3 ( ngn3 ) peptide, the aggregation of GSH-AuNPs was induced by ngn3 peptide under a certain concentration of salt. The color of AuNPs solution changed from red to blue as a function of the ngn3 peptide concentration. Thus, a rapid detection method for ngn3 peptide using GSH-AuNPs as colorimetric probe was established. The optimal experiment conditions were equilibrium time=10 min, pH=6. 0, CNaCl=100 mmol/L. Under the optimum conditions, the assay showed a linear response range of 20-300 μg/L for the peptide with a detection limit being 8 μg/L and exhibited excellent selectivity for ngn3 peptide.