Insulin - producing cells derived from stem cells: recent progress and future directions

Differentiation of multipotent stem cells to insulin-producing cells for treatment of diabetes mellitus: bone marrow- and adipose tissue-derived cells comparison

BACKGROUND

Mesenchymal stem cells (MSCs) from human adipose tissue and bone marrow have a great potential for use in cell therapy due to their ease of isolation, expansion, and differentiation. Our intention was to isolate and promote in vitro expansion and differentiation of MSCs from human adipose and bone marrow tissue into cells with a pancreatic endocrine phenotype and to compare the potency of these cells together.

METHODS AND RESULTS

MSCs were pre-induced with nicotinamide, mercaptoethanol, B-27 and b-FGF in L-DMEM for 2 days and re-induced again in supplemented H-DMEM for another 3 days. Expression of five genes in differentiated beta cells was evaluated by Real-time PCR and western blotting and the potency of insulin release in response to glucose stimulation was evaluated by insulin and C-peptide ELISA kit. The differentiated cells were evaluated by immunocytochemistry staining for Insulin and PDX-1. Quantitative RT-PCR results showed up-regulation of four genes in differentiated beta-islet cells (Insulin, Ngn-3, Pax-4 and Pdx-1) compared with the control. Western blot analysis showed that MSCs cells mainly produced proinsulin and insulin after differentiation but nestin was more expressed in pre-differentiated stem cells. Glucose and insulin secretion assay showed that insulin levels and C-peptide secretion were significantly increased in response to 10 mM glucose.

CONCLUSIONS

Our study showed that both adipose and bone marrow stem cells could differentiate into functional beta-islet cells but it seems that adipose stem cells could be a better choice for treatment of diabetes mellitus according to their higher potency.

Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions

The aim of this study was to differentiate canine adipose-derived mesenchymal stem cells (ADMSCs) into insulin-producing cells by using culture media with different compositions to determine the most efficient media. Stem cells isolated from the fat tissues close to the bitch uterus were distributed into 6 groups: (1) Dulbecco's modified Eagle medium (DMEM)-high glucose (HG), β-mercaptoethanol, and nicotinamide; (2) DMEM-HG, β-mercaptoethanol, nicotinamide, and exendin-4; (3) DMEM-HG, β-mercaptoethanol, nicotinamide, exendin-4, B27, nonessential amino acids, and l-glutamine; (4) DMEM-HG, β-mercaptoethanol, and nicotinamide (for the initial 8-d period), and DMEM-HG, β-mercaptoethanol, nicotinamide, exendin-4, B27, nonessential amino acids, l-glutamine, and basic fibroblast growth factor (for the remaining 8-d period); (5) DMEM-HG and fetal bovine serum; and (6) DMEM-low glucose and fetal bovine serum (standard control group). Adipose-derived mesenchymal stem cells from groups 1 to 5 gradually became round in shape and gathered in clusters. These changes differed between the groups. In group 3, the cell clusters were apparently more in numbers and gathered as bigger aggregates. Dithizone staining showed that groups 3 and 4 were similar in terms of the mean area of each aggregate stained for insulin. However, only in group 4, the number of insulin aggregates and the total area of aggregates stained were significantly bigger than in the other groups. The mRNA expression of PDX1, BETA2, MafA, and Insulin were also confirmed in all the groups. We conclude that by manipulating the composition of the culture medium it is possible to induce canine ADMSCs into insulin-producing cells, and the 2-staged protocol that was used promoted the best differentiation.