The Effect of Pancreas Islet-Releasing Factors on the Direction of Embryonic Stem Cells Towards Pdx1 Expressing Cells

Pancreatic Differentiation of Oral Minor Salivary Gland Stem Cells

INTRODUCTION

Stem cells from various sources including major salivary glands have been used to establish pancreatic differentiation in an attempt to provide new treatment options for patients with diabetes mellitus. In contrast, the potential of using the more easily accessible intraoral minor salivary glands has not been evaluated so far.

MATERIALS AND METHODS

Salivary stem cells were isolated from normal labial minor salivary glands that were removed during the excision of a mucocele and were attempted to differentiate into pancreatic cell lines using a culture medium enriched with activin A, retinoic acid and GLP-1.Real time RT-PCR was used to evaluate the expression of the genes of pancreatic transcription factors MafA, Ptf1a, Hb9 and Arx. Complementary, 22 labial minor salivary gland paraffin-embedded specimens were examined using immunohistochemistry for the presence of the relevant gene products of the pancreatic transcription factors Arx, MafA, Ptf1a and Pdx1.

RESULTS

The differentiated salivary stem cells(cells of passage 3) expressed the genes of the pancreatic transcription factors MafA, Ptf1a, Hb9 and Arx even on the first day of the experiment while immunohistochemistry also confirmed the presence of the protein products of Arx, MafA, Ptf1a as well as Pdx1[> 50% of the specimens for Arx(5/8) and MafA(7/8), < 50% for Ptf1a(5/11) and Pdx1(5/11)] in ducts, mesenchymal connective tissue and acinar cells.

CONCLUSIONS

Labial minor salivary glands may share gene and protein characteristics with pancreas suggesting a possible usefulness for pancreatic regeneration or substitution in cases of deficiency.

Evaluation of lncRNA Expression During the Differentiation of Mesenchymal Stem Cells to Insulin-Secreting Progenitors

Diabetes mellitus is a metabolic disease caused by a defect in insulin secretion, insulin function, or both that destroys pancreatic islet beta cells. There is ample evidence that long non-coding RNAs (lncRNAs) play a vital role in cell formation and differentiation. The present study aims to investigate the expression pattern of specific lncRNAs in mesenchymal stem cell (MSC) differentiation into insulin-producing beta cell (IPCs) progenitors for cell therapy purposes. MSCs were extracted from human umbilical cord Wharton jelly (hWJ-MSCs) using the explant method and cultured in two-dimensional (2D) and three-dimensional (3D) media on polylactic acid/Wax (PLA/Wax) nanofibrous scaffold using a three-step protocol containing CHIR99021 small molecules and Indolactam V. At the end of each differentiation step, immunocytochemistry and qRT-PCR were used to confirm the differentiation at the protein and RNA levels and the expression changes of six selective lncRNAs were evaluated by qRT-PCR. The results indicated that the expression of the selected lncRNAs was significantly altered during the differentiation process into beta progenitor cells, indicating their potential role in regulating the IPC differentiation process. More specifically, all of the desired lncRNAs demonstrated a significant increase during the beta cell differentiation, with HI-LNC71 and HI-LNA12 experiencing the highest expression in the produced Beta cell progenitors respectively (p<0.0001). These results can be valuable in tissue engineering and treatment studies by replacing beta precursor cells to control diabetic patients.

Simultaneous Administration of Berberine and Transplantation of Endometrial Stem Cell-Derived Insulin Precursor Cells on a Nanofibrous Scaffold to Treat Diabetes Mellitus in Mice

Today, significant success has been achieved in treating diabetes with cell therapy derived from various sources of stem and progenitors. The replacement of beta cells is one of the new diabetes treatment methods. To this end, the production of pancreatic beta precursors in cell culture has created an important research field for diabetes treatment. Endometrial stem cells were isolated using an enzymatic method, and after their identity was confirmed using a flow cytometry and differentiation potential assay, the isolated cells were cultured on an electrospun PCL/CS scaffold. Endometrial cells were differentiated into insulin-producing cells (IPCs), and gene expression was analyzed using the qRT-PCR and immunofluorescence to confirm the creation of IPCs. Then, IPCs on the scaffold along with berberine were applied to 5 groups of diabetic mice, and after 6 weeks, insulin, blood glucose, and weight of the animals were measured. The findings revealed that pancreatic markers were significantly expressed in IPCs compared to control cells. In addition, when compared to the control group and scaffolds, the receiving group of IPCs on scaffolds had a significant improvement (p ≤ 0.0015), and this improvement increased with the addition of berberine (decrease in blood sugar (133 mg/dL), and an increase in weight (5/39 g) and insulin (2.29 MIU/L). Thus, tissue engineering is a promising new strategy for treating diabetes and can be used in the future for cell therapy and suitable drugs for diabetic patients.

Small Molecule Differentiate PDX1-Expressing Cells Derived from Human Endometrial Stem Cells on PAN Electrospun Nanofibrous Scaffold: Applications for the Treatment of Diabetes in Rat

In this study, we designed an engineered tissue and transplanted it to an animal model, trying to take an effective step toward meeting the needs of diabetic patients. Here, human endometrial cells were differentiated into PDX1-expressing cells using a small molecule of Y-27632 on polyacrylonitrile (PAN) electrospun scaffolds and transplanted into diabetic rats. PAN nanofibers were made by electrospinning. RT-PCR and immunocytochemical analysis were performed to express pancreatic precursor (PP) genes. The differentiated cells were then transplanted into the abdominal cavity of diabetic rats with Streptozotocin. In another group of rats, differentiated cells were injected through the tail. Blood glucose was measured 7, 14, and 28 days after transplantation, and rat weight was also measured. The results showed that the expression of PP markers including Sox-17, Ngn3, Pdx1, and NKx2.2 genes was significantly increased in differentiated cells compared to the control group. In diabetic rats receiving differentiated cells, both transplanted and injected, glucose concentration as well as body weight improved compared to the control group. Rats receiving transplants in the peritoneum had a lower blood glucose concentration than those in the cell receiving group by injection, and the cell receiving group in the form of injections was more effective in increasing the body weight of rats than in the other groups. According to the results of the study, the transplantation of PP from endometrium using PAN scaffolding at the site of peritoneum could be recommended for the treatment of diabetes, although further studies are needed to provide a complete cure.

Current progress in stem cell therapy for type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is the most common chronic autoimmune disease in young patients and is characterized by the loss of pancreatic β cells; as a result, the body becomes insulin deficient and hyperglycemic. Administration or injection of exogenous insulin cannot mimic the endogenous insulin secreted by a healthy pancreas. Pancreas and islet transplantation have emerged as promising treatments for reconstructing the normal regulation of blood glucose in T1DM patients. However, a critical shortage of pancreases and islets derived from human organ donors, complications associated with transplantations, high cost, and limited procedural availability remain bottlenecks in the widespread application of these strategies. Attempts have been directed to accommodate the increasing population of patients with T1DM. Stem cell therapy holds great potential for curing patients with T1DM. With the advent of research on stem cell therapy for various diseases, breakthroughs in stem cell-based therapy for T1DM have been reported. However, many unsolved issues need to be addressed before stem cell therapy will be clinically feasible for diabetic patients. In this review, we discuss the current research advances in strategies to obtain insulin-producing cells (IPCs) from different precursor cells and in stem cell-based therapies for diabetes.

Insulin-Producing Cell Transplantation Platform for Veterinary Practice

Diabetes mellitus (DM) remains a global concern in both human and veterinary medicine. Type I DM requires prolonged and consistent exogenous insulin administration to address hyperglycemia, which can increase the risk of diabetes complications such as retinopathy, nephropathy, neuropathy, and heart disorders. Cell-based therapies have been successful in human medicine using the Edmonton protocol. These therapies help maintain the production of endogenous insulin and stabilize blood glucose levels and may possibly be adapted to veterinary clinical practice. The limited number of cadaveric pancreas donors and the long-term use of immunosuppressive agents are the main obstacles for this protocol. Over the past decade, the development of potential therapies for DM has mainly focused on the generation of effective insulin-producing cells (IPCs) from various sources of stem cells that can be transplanted into the body. Another successful application of stem cells in type I DM therapies is transplanting generated IPCs. Encapsulation can be an alternative strategy to protect IPCs from rejection by the body due to their immunoisolation properties. This review summarizes current concepts of IPCs and encapsulation technology for veterinary clinical application and proposes a potential stem-cell-based platform for veterinary diabetic regenerative therapy.

Cdc42 Promotes ADSC-Derived IPC Induction, Proliferation, And Insulin Secretion Via Wnt/β-Catenin Signaling

PURPOSE

Type 1 diabetes mellitus (T1DM) is characterized by irreversible islet β cell destruction. Accumulative evidence indicated that Cdc42 and Wnt/β-catenin signaling both play a critical role in the pathogenesis and development of T1DM. Further, bio-molecular mechanisms in adipose-derived mesenchymal stem cells (ADSCs)-derived insulin-producing cells (IPCs) remain largely unknown. Our aim was to investigate the underlying mechanism of Cdc42/Wnt/β-catenin pathway in ADSC-derived IPCs, which may provide new insights into the therapeutic strategy for T1DM patients.

METHODS

ADSC induction was accomplished with DMSO under high-glucose condition. ML141 (Cdc42 inhibitor) and Wnt-3a (Wnt signaling activator) were administered to ADSCs from day 2 until the induction finished. Morphological changes were determined by an inverted microscope. Dithizone staining was employed to evaluate the induction of ADSC-derived IPCs. qPCR and Western blotting were employed to measure the mRNA and protein expression level of islet cell development-related genes and Wnt signaling-related genes. The proliferation ability of ADSC-derived IPCs was also detected with a cell counting kit (CCK) assay. The expression and secretion of Insulin were detected with immunofluorescence test and enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTS

During induction, morphological characters of ADSCs changed into spindle and round shape, and formed islet-line cell clusters, with brown dithizone-stained cytoplasm. Expression levels of islet cell development-related genes were up-regulated in ADSC-derived IPCs. Wnt-3a promoted Wnt signaling markers and islet cell development-related gene expression at mRNA and protein levels, while ML141 played a negative effect. Wnt-3a promoted ADSC-derived IPC proliferation and glucose-stimulated insulin secretion (GSIS), while ML141 played a negative effect.

CONCLUSION

Our research demonstrated that DMSO and high-glucose condition can induce ADSCs into IPCs, and Wnt signaling promotes the induction. Cdc42 may promote IPC induction, IPC proliferation and insulin secretion via Wnt/β-catenin pathway, meaning that Cdc42 may be regarded as a potential target in the treatment of T1DM.

Redefining the signaling pathways from pluripotency to pancreas development: In vitro β-cell differentiation

Pancreatic β-cells are destroyed by the immune system, in type 1 diabetes (T1D) and are impaired by glucose insensitivity in type 2 diabetes (T2D). Islet-cells transplantation is a promising therapeutic approach based on in vitro differentiation of pluripotent stem cells (PSCs) to insulin-producing cells (IPCs). According to evolutionary stages in β-cell development, there are several distinct checkpoints; each one has a unique characteristic, including definitive endoderm (DE), primitive gut (PG), posterior foregut (PF), pancreatic epithelium (PE), endocrine precursor (EP), and immature β-cells up to functional β-cells. A better understanding of the gene regulatory networks (GRN) and associated transcription factors in each specific developmental stage, guarantees the achievement of the next successful checkpoints and ensures an efficient β-cell differentiation procedure. The new findings in signaling pathways, related to the development of the pancreas are discussed here, including Wnt, Activin/Nodal, FGF, BMP, retinoic acid (RA), sonic hedgehog (Shh), Notch, and downstream regulators, required for β-cell commitment. We also summarized different approaches in the IPCs protocol to conceptually define a standardized system, leading to the creation of a reproducible method for β-cell differentiation. To normalize blood glucose level in diabetic mice, the replacement therapy in the early differentiation stage, such as EP stages was associated with better outcome when compared with the fully differentiated β-cells' graft.

Therapeutic potential of human mesenchymal stem cells derived beta cell precursors on a nanofibrous scaffold: An approach to treat diabetes mellitus

Diabetes mellitus is an autoimmune and chronic disorder that is rapidly expanding worldwide due to increasing obesity. In the current study, we were able to design a reliable 3-dimensional differentiation process of human Wharton's jelly mesenchymal stem cells into pancreatic beta cell precursors (PBCPs) and detected that transplanted PBCPs could improve hyperglycemia in a diabetes-induced model in mice. Polylactic acid/chitosan nanofibrous scaffold was prepared using an electrospinning method. Quantitative real-time reverse transcription-polymerase chain reaction and immunocytochemistry analysis were carried out to assess pancreatic marker expression in the differentiated cells. PBCPs were transplanted under the kidney capsule of diabetic mice that induced streptozotocin injection 14 days before the transplantation. Moreover, an intraperitoneal glucose tolerance test (ipGTT) was carried out 2 and 4 weeks after the transplantation to measure the reaction to a sudden increase of the blood glucose level in the transplanted animals. The results indicated that the expression of SRY (sex determining region Y)-box (Sox17), forkhead box A2 (FoxA2), pancreatic and duodenal homeobox 1 (Pdx1), neurogenin 3 (Ngn3), hepatic nuclear factor 4, alpha (Hnf4α), and NK2 homeobox 2 (Nkx2.2) were increased significantly in the differentiated cells compared with that of the control group. In the current study, the diabetic disease was confirmed by measuring blood glucose and proved by conducting some other behavioral tests. After the PBCPs transplantation in a diabetic model, the ipGTT and hyperglycemia investigation during the determinant times confirmed the disease's significant improvement in the experimental models. In this study, some preclinical data suggested that the transplantation of PBCPs associated with appropriate nanofiber scaffold can be utilized for the treatment of diabetes models. In addition, studies are required to elucidate the molecular mechanism of PBCPs acting in diabetes models before being used for patients with diabetes.