Enhanced insulin production and reprogramming efficiency of mesenchymal stem cells derived from porcine pancreas using suitable induction medium

Porcine pancreas mesenchymal cell characterization and functional differentiation into insulin‑producing cells in vitro

Cell therapy is a promising treatment strategy for patients with type 1 diabetes. Porcine pancreas-derived mesenchymal stromal cells (PMSCs) have emerged as one of the most widely used cell resources owing to their high proliferative capacity and multi-lineage differentiation potential. Although the induction efficiency and insulin production of induced insulin-producing cells (IPCs) derived from PMSCs have been estimated, these have primarily focused on the function of induced cells and alterations in related gene expression levels. However, morphological analyses and biological characterization of PMSCs and induced IPCs have not been conducted. Therefore, the present study aimed to optimize an induction protocol, resulting in a 78.92% induction rate. The present study investigated the biological characteristics of PMSCs and optimized a simple but functional three-step protocol to transform PMSCs into IPCs. PMSCs were isolated from 2–3-month-old Bama miniature pig embryos, which were then subcultured to passage 16. The surface markers pancreatic and duodenal homeobox 1, NK6 homeobox 1, Vimentin, Nestin, CD73, CD90, neurogenin 3, CD45 and CD34 were detected by immunofluorescence staining or flow cytometry. Proliferative capacity was evaluated by constructing growth curves of cells at three different passages. Functional differentiation was assessed by morphological observation, dithizone staining, and immunofluorescence staining of C-peptide, insulin, NK6 homeobox 1 and glucagon. The production of insulin by differentiated cells was also analyzed by performing ELISAs. The results demonstrated that differentiated cells were distributed with an islet-like structure, expressed specific markers C-peptide and insulin, and displayed glucose responsiveness. The results of the present study demonstrated that PMSCs were functionally induced into IPCs with the optimized three-step protocol, which may serve as a potential cell therapy strategy to widen the availability and promote the clinical application of cell therapy.

Bioscaffolds embedded with regulatory modules for cell growth and tissue formation: A review

The demand for artificial organs has greatly increased because of various aging-associated diseases and the wide need for organ transplants. A recent trend in tissue engineering is the precise reconstruction of tissues by the growth of cells adhering to bioscaffolds, which are three-dimensional (3D) structures that guide tissue and organ formation. Bioscaffolds used to fabricate bionic tissues should be able to not only guide cell growth but also regulate cell behaviors. Common regulation methods include biophysical and biochemical stimulations. Biophysical stimulation cues include matrix hardness, external stress and strain, surface topology, and electromagnetic field and concentration, whereas biochemical stimulation cues include growth factors, proteins, kinases, and magnetic nanoparticles. This review discusses bioink preparation, 3D bioprinting (including extrusion-based, inkjet, and ultraviolet-assisted 3D bioprinting), and regulation of cell behaviors. In particular, it provides an overview of state-of-the-art methods and devices for regulating cell growth and tissue formation and the effects of biophysical and biochemical stimulations on cell behaviors. In addition, the fabrication of bioscaffolds embedded with regulatory modules for biomimetic tissue preparation is explained. Finally, challenges in cell growth regulation and future research directions are presented.

Functional β-Cell Differentiation of Small-Tail Han Sheep Pancreatic Mesenchymal Stem Cells and the Therapeutic Potential in Type 1 Diabetic Mice

OBJECTIVES

This study aims to investigate the characteristics of sheep pancreatic mesenchymal stem cells (PSCs) and therapeutic potential of differentiated β-like cells in streptozotocin-induced diabetic mice.

METHODS

Pancreatic mesenchymal stem cells were isolated from 3- to 4-month-old sheep embryos, and their biological characteristics were explored. The function and therapeutic potential of differentiated β-like insulin-producing cells were also investigated in vitro and in vivo. Differentiated cells were identified through dithizone staining and immunofluorescence staining. Insulin secretion was analyzed using an enzyme-linked immunosorbent assay kit. The preliminary therapeutic potential of induced β-like cells in diabetic mice was detected by blood glucose and body weight.

RESULTS

Primary PSCs were isolated and subcultured up to passage 36. Immunofluorescence staining presented PSC-expressed important markers such as Pdx1, Nkx6-1, Ngn3, and Nestin. Primary PSCs could be induced into functional pancreatic β-like islet cells with a 3-step protocol. The induced β-like islet cells could ameliorate blood glucose in diabetic mice.

CONCLUSIONS

The method proposed for generating pancreatic islet β cells provided a preliminary phenotypic investigation of induced cell treatment in diabetic mice, and also laid a foundation in the identification of pharmaceutical targets to treat insulin-dependent diabetes.