Stem Cell-derived Insulin-producing Cells Research Articles

An INSULIN and IAPP dual reporter enables tracking of functional maturation of stem cell-derived insulin producing cells

ObjectiveHuman embryonic stem cell (hESC; SC)-derived pancreatic β cells can be used to study diabetes pathologies and develop cell replacement therapies. Although current differentiation protocols yield SCβ cells with varying degrees of maturation, these cells still differ from deceased donor human β cells in several respects. We sought to develop a reporter cell line that could be used to dynamically track SCβ cell functional maturation. MethodsTo monitor SCβ cell maturation in vitro, we created an IAPP-2A-mScar and INSULIN-2A-EGFP dual fluorescent reporter (INS2A-EGFP/+;IAPP2A-mScarlet/+) hESC line using CRISPR/Cas9. Pluripotent SC were then differentiated using a 7-stage protocol to islet-like cells. Immunohistochemistry, flow cytometry, qPCR, GSIS and electrophysiology were used to characterise resulting cell populations. ResultsWe observed robust expression of EGFP and mScarlet fluorescent proteins in insulin- and IAPP-expressing cells without any compromise to their differentiation. We show that the proportion of insulin-producing cells expressing IAPP increases over a 4-week maturation period, and that a subset of insulin-expressing cells remain IAPP-free. Compared to this IAPP-free population, we show these insulin- and IAPP-expressing cells are less polyhormonal, more glucose-sensitive, and exhibit decreased action potential firing in low (2.8 mM) glucose. ConclusionsThe INS2A-EGFP/+;IAPP2A-mScarlet/+ hESC line provides a useful tool for tracking populations of maturing hESC-derived β cells in vitro. This tool has already been shared with 3 groups and is freely available to all.

Metabolic switching, growth kinetics and cell yields in the scalable manufacture of stem cell-derived insulin-producing cells

BackgroundDiabetes is a disease affecting over 500 million people globally due to insulin insufficiency or insensitivity. For individuals with type 1 diabetes, pancreatic islet transplantation can help regulate their blood glucose levels. However, the scarcity of cadaveric donor islets limits the number of people that could receive this therapy. To address this issue, human pluripotent stem cells offer a potentially unlimited source for generating insulin-producing cells through directed differentiation. Several protocols have been developed to make stem cell-derived insulin-producing cells. However, there is a lack of knowledge regarding the bioprocess parameters associated with these differentiation protocols and how they can be utilized to increase the cell yield.MethodsWe investigated various bioprocess parameters and quality target product profiles that may influence the differentiation pipeline using a seven-stage protocol in a scalable manner with CellSTACKs and vertical wheel bioreactors (PBS-Minis).ResultsCells maintained > 80% viability through all stages of differentiation and appropriately expressed stage-specific markers. During the initial four stages leading up to the development of pancreatic progenitors, there was an increase in cell numbers. Following pancreatic progenitor stage, there was a gradual decrease in the percentage of proliferative cells, as determined by Ki67 positivity, and a significant loss of cells during the period of endocrine differentiation. By minimizing the occurrence of aggregate fusion, we were able to enhance cell yield during the later stages of differentiation. We suggest that glucose utilization and lactate production are cell quality attributes that should be considered during the characterization of insulin-producing cells derived from stem cells. Our findings also revealed a gradual metabolic shift from glycolysis, during the initial four stages of pancreatic progenitor formation, to oxidative phosphorylation later on during endocrine differentiation. Furthermore, the resulting insulin-producing cells exhibited a response to several secretagogues, including high glucose.ConclusionThis study demonstrates process parameters such as glucose consumption and lactate production rates that may be used to facilitate the scalable manufacture of stem cell-derived insulin-producing cells.

Human A2-CAR T Cells Reject HLA-A2 + Human Islets Transplanted Into Mice Without Inducing Graft-versus-host Disease.

Type 1 diabetes is an autoimmune disease characterized by T-cell-mediated destruction of pancreatic beta-cells. Islet transplantation is an effective therapy, but its success is limited by islet quality and availability along with the need for immunosuppression. New approaches include the use of stem cell-derived insulin-producing cells and immunomodulatory therapies, but a limitation is the paucity of reproducible animal models in which interactions between human immune cells and insulin-producing cells can be studied without the complication of xenogeneic graft-versus-host disease (xGVHD). We expressed an HLA-A2-specific chimeric antigen receptor (A2-CAR) in human CD4 + and CD8 + T cells and tested their ability to reject HLA-A2 + islets transplanted under the kidney capsule or anterior chamber of the eye of immunodeficient mice. T-cell engraftment, islet function, and xGVHD were assessed longitudinally. The speed and consistency of A2-CAR T-cell-mediated islet rejection varied depending on the number of A2-CAR T cells and the absence/presence of coinjected peripheral blood mononuclear cells (PBMCs). When <3 million A2-CAR T cells were injected, coinjection of PBMCs accelerated islet rejection but also induced xGVHD. In the absence of PBMCs, injection of 3 million A2-CAR T cells caused synchronous rejection of A2 + human islets within 1 wk and without xGVHD for 12 wk. Injection of A2-CAR T cells can be used to study rejection of human insulin-producing cells without the complication of xGVHD. The rapidity and synchrony of rejection will facilitate in vivo screening of new therapies designed to improve the success of islet-replacement therapies.

1808-PUB: Effective and Durable Stem-Cell-Enabled Therapy of Autoimmune T1DM in Rodents and Dogs Provides the Scientific Basis for the First-in-Human Trial Using I.P. Administered “Neo-Islets,” 3-D Organoids of Allogeneic Islet, and Mesenchymal Stromal Cells—The Omentum Becomes the New Endocrine Pancreas without the Need for Antirejection Drugs

Two initial reports from Clinical Trials with cell-based interventions for the urgently needed therapy of T1DM show: (a) Open, s.c.-placed encapsulation devices containing insulin-producing progenitor cells that require anti-rejection drugs have failed to adequately improve glycemic control. (b) The intraportal administration of stem cell-derived insulin-producing cells, requiring anti-rejection drugs, has shown promising results in 2 or 3 subjects. However, the inability to retrieve these cells and the need for anti-rejection drugs remain a concern. Our approach harnesses the immune-modulating and -isolating, anti-inflammatory, angiogenic, anti-apoptotic and other trophic actions of Mesenchymal Stromal Cells (MSCs). First, we demonstrated that allogeneic Neo-islets (NIs), islet-sized organoids composed of equal numbers of MSCs and culture expanded Islet Cells do, when given i.p., omentally engraft, redifferentiate, re-express all islet hormones and permanently restore euglycemia in auto-immune diabetic NOD mice, i.e., without encapsulation devices or antirejection drugs. The omentum becomes the new endocrine pancreas. Second, i.p. therapy of spontaneously diabetic pet dogs with allogeneic canine NIs significantly improved glycemia and insulin needs (&amp;gt; 3 years), and this without immune response (abstract this meeting). Third, human NIs permanently correct streptozotocin-induced diabetes in NOD/SCID mice. Removal of the omentally-engrafted NIs promptly restores the diabetic state. No long-term complications of the NI therapy have been observed. Based on this body of evidence, a successful Pre-IND meeting with the FDA was held and final Proof-of-Concept studies that are expected to lead IND approval are ongoing. Disclosure A.Gooch: Board Member; SymbioCellTech, LLC, Employee; SymbioCellTech, LLC, Stock/Shareholder; SymbioCellTech, LLC. C.Westenfelder: Board Member; SymbioCellTech, LLC., Employee; SymbioCellTech, LLC., Research Support; SymbioCellTech, LLC., Stock/Shareholder; SymbioCellTech, LLC.

Enrichment of stem cell-derived pancreatic beta-like cells and controlled graft size through pharmacological removal of proliferating cells.

Transplantation of limited human cadaveric islets into type 1 diabetic patients results in ∼35months of insulin independence. Direct differentiation of stem cell-derived insulin-producing beta-like cells (sBCs) that can reverse diabetes in animal models effectively removes this shortage constraint, but uncontrolled graft growth remains a concern. Current protocols do not generate pure sBCs, but consist of only 20%-50% insulin-expressing cells with additional cell types present, some of which are proliferative. Here, we show the selective ablation of proliferative cells marked by SOX9 by simple pharmacological treatment invitro. This treatment concomitantly enriches for sBCs by ∼1.7-fold. Treated sBC clusters show improved function invitro and invivo transplantation controls graft size. Overall, our study provides a convenient and effective approach to enrich for sBCs while minimizing the presence of unwanted proliferative cells and thus has important implications for current cell therapy approaches.

A predictive computational platform for optimizing the design of bioartificial pancreas devices

The delivery of encapsulated islets or stem cell-derived insulin-producing cells (i.e., bioartificial pancreas devices) may achieve a functional cure for type 1 diabetes, but their efficacy is limited by mass transport constraints. Modeling such constraints is thus desirable, but previous efforts invoke simplifications which limit the utility of their insights. Herein, we present a computational platform for investigating the therapeutic capacity of generic and user-programmable bioartificial pancreas devices, which accounts for highly influential stochastic properties including the size distribution and random localization of the cells. We first apply the platform in a study which finds that endogenous islet size distribution variance significantly influences device potency. Then we pursue optimizations, determining ideal device structures and estimates of the curative cell dose. Finally, we propose a new, device-specific islet equivalence conversion table, and develop a surrogate machine learning model, hosted on a web application, to rapidly produce these coefficients for user-defined devices.

1295-P: Learning from Immune Privileged Tissue Stem Cells to Generate Hypoimmunogenic Islets

The ultimate goal to accomplish a definitive cure for Type 1 Diabetes (T1D) is to replace the lost beta-cell mass while ensuring its long-lasting survival. This could be done by transplantation of pancreatic islets or stem cell-derived insulin-producing cells. However, any replacement will irrevocably succumb to the same autoimmune attack that killed the original beta-cells. Moreover, a mismatch between donor cells and recipient patients adds an allo-graft rejection. Thus, it is of the utmost importance to develop strategies to protect transplanted pancreatic islets from immune attack. Unfortunately, many approaches aiming at restoring tolerance by manipulating immune cells have been tested and, although safe, have shown only limited efficacy. Inflammatory processes, infections or major lifestyle changes can easily alter the balance again towards immune activation. We recently discovered the existence of immune privileged stem cells in the skin and muscle, and found that their ability to resist direct attack by T cells was not dependent on a physical barrier. Instead, it is a cell-autonomous process that allows independent cloaking from immune cells. Here we propose to exploit the molecular circuits controlling this striking phenomenon (that already naturally occurs in our bodies) to provide similar protection to islets for transplantation. We identified a molecular pathway that reduces antigen presentation allowing protection from T cells while preserving enough MHC class I to not trigger a Natural Killer (NK) cell response. Since this mechanism of protection is cell intrinsic, changes in overall immune function should not alter the ability of engineered islets to hide from immune rejection allowing for long-lasting survival. Disclosure J.Agudo: None. Funding American Diabetes Association (1-20-ACE-08)

841-P: Scientific Basis for the First-in-Human Trial of “Neo-Islet”–Mediated Functional Cure of T1DM: The Intraperitoneal Administration of “Neo-Islets,” 3-D Organoids of Allogeneic Islet and Mesenchymal Stromal Cells from Rodents, Dogs, and Humans Durably Cures

Initial reports from Clinical Trials with cell-based interventions for the urgently needed therapy of T1DM show: (1) An open, s.c.-placed encapsulation device containing insulin-producing progenitor cells that require anti-rejection drugs has failed to adequately improve glycemic control. (2) The i.v. administration of stem cell-derived insulin-producing cells, requiring anti-rejection drugs, has shown promising results in 1 or 2 subjects. However, their unknown systemic location and inability to retrieve these cells remain a concern. Our approach harnesses the immune-modulating and -isolating, anti-inflammatory, angiogenic, anti-apoptotic and other trophic actions of Mesenchymal Stromal Cells (MSCs) . First, we demonstrated that allogeneic Neo-islets (NIs) , islet-sized organoids composed of equal numbers of MSCs and culture expanded Islet Cells do, when given i.p., omentally engraft, redifferentiate, re-express all islet hormones (Abstract this meeting) and permanently restore euglycemia in auto-immune diabetic NOD mice, i.e., without encapsulation devices or antirejection drugs. The omentum becomes the new endocrine pancreas. Second, i.p. therapy of spontaneously diabetic pet dogs with allogeneic canine NIs significantly improved glycemia and insulin needs (&amp;gt; 3 years) , and this without immune response. Third, human NIs permanently correct streptozotocin-induced diabetes in NOD/SCID mice. Removal of the omentally-engrafted NIs promptly restores the diabetic state. No long-term complications of the NI therapy have been observed. Based on this body of evidence, a successful Pre-IND meeting with the FDA was held and final Proof-of-Concept studies that are expected to lead IND approval are ongoing. Disclosure C.Westenfelder: None. S.S.Chowdhury: Employee; SymbioCellTech, LLC. A.Gooch: Board Member; SymbioCellTech, LLC., Employee; SymbioCellTech, LLC., Stock/Shareholder; SymbioCellTech, LLC.

Enhanced Differentiation Capacity and Transplantation Efficacy of Insulin-Producing Cell Clusters from Human iPSCs Using Permeable Nanofibrous Microwell-Arrayed Membrane for Diabetes Treatment.

Although pancreatic islet transplantation is a potentially curative treatment for insulin-dependent diabetes, a shortage of donor sources, low differentiation capacity, and transplantation efficacy are major hurdles to overcome before becoming a standard therapy. Stem cell-derived insulin-producing cells (IPCs) are a potential approach to overcoming these limitations. To improve the differentiation capacity of the IPCs, cell cluster formation is crucial to mimic the 3D structure of the islet. This study developed a biodegradable polycaprolactone (PCL) electrospun nanofibrous (NF) microwell-arrayed membrane permeable to soluble factors. Based on the numerical analysis and experimental diffusion test, the NF microwell could provide sufficient nutrients, unlike an impermeable PDMS (polydimethylsiloxane) microwell. The IPC clusters in the NF microwells showed higher gene expression of insulin and PDX1 and insulin secretion than the PDMS microwells. The IPC clusters in the NF microwell-arrayed membrane could be directly transplanted. Transplanted IPC clusters in the microwells survived well and expressed PDX1 and insulin. Additionally, human c-peptide was identified in the blood plasma at two months after transplantation of the membranes. The NF microwell-arrayed membrane can be a new platform promoting IPC differentiation capacity and realizing an in situ transplantation technique for diabetic patients.

A 3D bioprinted hybrid encapsulation system for delivery of human pluripotent stem cell-derived pancreatic islet-like aggregates

Islet transplantation is a promising treatment for type 1 diabetes. However, treatment failure can result from loss of functional cells associated with cell dispersion, low viability, and severe immune response. To overcome these limitations, various islet encapsulation approaches have been introduced. Among them, macroencapsulation offers the advantages of delivering and retrieving a large volume of islets in one system. In this study, we developed a hybrid encapsulation system composed of a macroporous polymer capsule with stagger-type membrane and assemblable structure, and a nanoporous decellularized extracellular matrix (dECM) hydrogel containing pancreatic islet-like aggregates using 3D bioprinting technique. The outer part (macroporous polymer capsule) was designed to have an interconnected porous architecture, which allows insulin-producing β-cells encapsulated in the hybrid encapsulation system to maintain their cellular behaviors, including viability, cell proliferation, and insulin-producing function. The inner part (nanoporous dECM hydrogel), composed of the 3D biofabricated pancreatic islet-like aggregates, was simultaneously placed into the macroporous polymer capsule in one step. The developed hybrid encapsulation system exhibited biocompatibility in vitro and in vivo in terms of M1 macrophage polarization. Furthermore, by controlling the printing parameters, we generated islet-like aggregates, improving cell viability and functionality. Moreover, the 3D bioprinted pancreatic islet-like aggregates exhibited structural maturation and functional enhancement associated with intercellular interaction occurring at the β-cell edges. In addition, we also investigated the therapeutic potential of a hybrid encapsulation system by integrating human pluripotent stem cell-derived insulin-producing cells, which are promising to overcome the donor shortage problem. In summary, these results demonstrated that the 3D bioprinting approach facilitates the fabrication of a hybrid islet encapsulation system with multiple materials and potentially improves the clinical outcomes by driving structural maturation and functional improvement of cells.

The Importance of Proper Oxygenation in 3D Culture.

Cell culture typically employs inexpensive, disposable plasticware, and standard humidified CO2/room air incubators (5% CO2, ∼20% oxygen). These methods have historically proven adequate for the maintenance of viability, function, and proliferation of many cell types, but with broad variation in culture practices. With technological advances it is becoming increasingly clear that cell culture is not a “one size fits all” procedure. Recently, there is a shift toward comprehension of the individual physiological niches of cultured cells. As scale-up production of single cell and 3D aggregates for therapeutic applications has expanded, researchers have focused on understanding the role of many environmental metabolites/forces on cell function and viability. Oxygen, due to its role in cell processes and the requirement for adequate supply to maintain critical energy generation, is one such metabolite gaining increased focus. With the advent of improved sensing technologies and computational predictive modeling, it is becoming evident that parameters such as cell seeding density, culture media height, cellular oxygen consumption rate, and aggregate dimensions should be considered for experimental reproducibility. In this review, we will examine the role of oxygen in 3D cell culture with particular emphasis on primary islets of Langerhans and stem cell-derived insulin-producing SC-β cells, both known for their high metabolic demands. We will implement finite element modeling (FEM) to simulate historical and current culture methods in referenced manuscripts and innovations focusing on oxygen distribution. Our group and others have shown that oxygen plays a key role in proliferation, differentiation, and function of these 3D aggregates. Their culture in plastic consistently results in core regions of hypoxia/anoxia exacerbated by increased media height, aggregate dimensions, and oxygen consumption rates. Static gas permeable systems ameliorate this problem. The use of rotational culture and other dynamic culture systems also have advantages in terms of oxygen supply but come with the caveat that these endocrine aggregates are also exquisitely sensitive to mechanical perturbation. As recent work demonstrates, there is a strong rationale for the use of alternate in vitro systems to maintain physio-normal environments for cell growth and function for better phenotypic approximation of in vivo counterparts.

Stem Cell-Derived Insulin-Producing Cells in 3D Engineered Tissue in a Perfusion Flow Bioreactor.

To circumvent the lack of donor pancreas, insulin-producing cells (IPCs) derived from pluripotent stem cells emerged as a viable cell source for the treatment of type 1 diabetes. While it has been shown that IPCs can be derived from pluripotent stem cells using various protocols, the long-term viability and functional stability of IPCs in vitro remains a challenge. Thus, the principles of three-dimensional (3D) tissue engineering and a perfusion flow bioreactor were used in this study to establish 3D microenvironment suitable for long-term in vitro culture of IPCs-derived from mouse embryonic stem cells. It was observed that in static 3D culture of IPCs, the viability decreased gradually with longer time in culture. However, when a low flow (0.02 mL/min) was continuously applied to 3D IPC containing tissues, enhanced survival and function of IPCs were demonstrated. IPCs cultured under low flow exhibited a significantly enhanced glucose responsiveness and upregulation of Ins1 compared to that of static culture. In summary, this study demonstrates the feasibility and benefits of 3D engineered tissue environment combined with perfusion flow in vitro for culturing stem cell-derived IPCs. Impact statement This in vitro three-dimensional tissue system combined with the flow can be used to better understand the role of biophysical cues that facilitates improved function and maturation of stem cell-derived insulin-producing cells, which can ultimately advance the field of pancreatic tissue engineering as well as in diabetes treatment.

Alginate/Pluronic F127-based encapsulation supports viability and functionality of human dental pulp stem cell-derived insulin-producing cells

BackgroundCurrent approach for diabetes treatment remained several adverse events varied from gastrointestinal to life-threatening symptoms. Regenerative therapy regarding Edmonton protocol has been facing serious limitations involving protocol efficiency and safety. This led to the study for alternative insulin-producing cell (IPC) resource and transplantation platform. In this study, evaluation of encapsulated human dental pulp-derived stem cell (hDPSC)-derived IPCs by alginate (ALG) and pluronic F127-coated alginate (ALGPA) was performed.ResultsThe results showed that ALG and ALGPA preserved hDPSC viability and allowed glucose and insulin diffusion in and out. ALG and ALGPA-encapsulated hDPSC-derived IPCs maintained viability for at least 336 h and sustained pancreatic endoderm marker (NGN3), pancreatic islet markers (NKX6.1, MAF-A, ISL-1, GLUT-2 and INSULIN), and intracellular pro-insulin and insulin expressions for at least 14 days. Functional analysis revealed a glucose-responsive C-peptide secretion of ALG- and ALGPA-encapsulated hDPSC-derived IPCs at 14 days post-encapsulation.ConclusionALG and ALGPA encapsulations efficiently preserved the viability and functionality of hDPSC-derived IPCs in vitro and could be the potential transplantation platform for further clinical application.

2067-P: Cell Therapies for Diabetes Using Spontaneous Canine Diabetes as a Translational Model

FDA approved Clinical Trials are already under way using stem cell-derived insulin-producing cells (IPCs) for the treatment of type 1 diabetes in humans. Differentiation methods used to derive beta-cell like IPCs have greatly improved over the last few years, resulting in highly efficacious treatment of high blood glucose in diabetic animals models. However, there still remains major challenges of developing an effective cure in humans due to challenges of delivery and long term survival and function of grafts. Like humans, spontaneous canine diabetes is a commonly diagnosed, multifactorial endocrine disorder in dogs which clinically presents as a type 1 diabetes disorder. In order to develop successful human diabetes therapies using stem cells, spontaneous canine diabetes offers a very attractive translational model. Dogs have major similarities to humans including the clinical signs, pathophysiology and long-term clinical management of the disease by use of exogenous insulin injections. Using cadaveric canine islets and our Core-Shell Spherification (CSS) microencapsulation methods, we have successfully reversed hyperglycemia in dogs for varying time periods. Our data confirms that similar to humans, islet transplantation is a viable option for diabetes treatment in dogs. To further develop canine diabetes as a translational model for human diabetes, while developing stem cell therapies for dogs, we have successfully generated IPCs from human pluripotent stem cells. The IPC clusters express key beta-cell biomarkers including PDX1, NK6.1, NeuroD1, and insulin. The majority of endocrine cells in clusters are single hormonal where separate cells express ARX and glucagon. These cell clusters corrected induced diabetes in mouse models when transplanted under the kidney capsule. Our studies will further allow us to further test the use of the canine model, both in allo- and xenogeneic transplant environments, for further pre-clinical development in humans. Disclosure A. Wildey: None. S.J. Williams: None. M. Hamilton: None. S. Harrington: None. L. Ott: Employee; Self; Likarda, LLC. F. Karanu: Employee; Self; Likarda, LLC.

In vitro differentiation induction of embryonal carcinoma stem cells into insulin-producing cells by Cichorium intybus L. leaf extract.

Medicinal herb Cichorium intybus L. (chicory) has been used traditionally for the treatment of various diseases, including diabetes. One of the promising therapeutic options to treat diabetes is replacing the degenerative pancreatic β cells by stem cell-derived IPCs (insulin-producing cells). By the combination of cell therapy as a modern approach and traditional medicine, the current study was designed to evaluate the effects of chicory leaf extract (LE) on the differentiation potential of P19 EC cells (an embryonal carcinoma stem cell line) into IPCs. The plant (voucher no. 4567) were collected and deposited in the herbarium of Shahrekord University. In vitro experiments were designed to compare the effects of various concentrations of LE on the differentiation potential of P19 EC cells. The differentiated cells showed morphological characteristics of pancreatic β cells. They could also synthesized and secreted insulin when exposed to glucose. Moreover, the cells expressed specific proteins and genes of mature pancreatic β cells. In conclusion, LE as a natural herbal extract was efficiently able to induce the differentiation of P19 EC cells into the clusters similar to pancreatic islets with the molecular, cellular and functional characteristics of mature β cells.

Supporting Survival of Transplanted Stem-Cell-Derived Insulin-Producing Cells in an Encapsulation Device Augmented with Controlled Release of Amino Acids.

Pancreatic islet transplantation is a promising treatment for type I diabetes, which is a chronic autoimmune disease in which the host immune cells attack insulin-producing beta cells. The impact of this therapy is limited due to tissue availability and dependence on immunosuppressive drugs that prevent immune rejection of the transplanted cells. These issues can be solved by encapsulating stem cell-derived insulin-producing cells in an immunoprotective device. However, encapsulation exacerbates ischemia, and the lack of vasculature at the implantation site post-transplantation worsens graft survival. Here, an encapsulation device that supplements nutrients to the cells is developed to improve the survival of encapsulated stem cell-derived insulin-producing cells in the poorly vascularized subcutaneous space. An internal compartment in the device is fabricated to provide zero-order release of alanine and glutamine for several weeks. The amino acid reservoir sustains viability of insulin-producing cells in nutrient limiting conditions in vitro. Moreover, the reservoir also increases cell survival by 30% after transplanting the graft in the subcutaneous space.

Targeted Derivation of Organotypic Glucose- and GLP-1-Responsive β Cells Prior to Transplantation into Diabetic Recipients.

SummaryGeneration of functional β cells from pluripotent sources would accelerate diagnostic and therapeutic applications for diabetes research and therapy. However, it has been challenging to generate competent β cells with dynamic insulin-secretory capacity to glucose and incretin stimulations. We introduced transcription factors, critical for β-cell development and function, in differentiating human induced pluripotent stem cells (PSCs) and assessed the impact on the functionality of derived β-cell (psBC) progeny. A perifusion system revealed stepwise transduction of the PDX1, NEUROG3, and MAFA triad (PNM) enabled in vitro generation of psBCs with glucose and GLP-1 responsiveness within 3 weeks. PNM transduction upregulated genes associated with glucose sensing, insulin secretion, and β-cell maturation. In recipient diabetic mice, PNM-transduced psBCs showed glucose-responsive insulin secretion as early as 1 week post transplantation. Thus, enhanced pre-emptive β-cell specification of PSCs by PNM drives generation of glucose- and incretin-responsive psBCs in vitro, offering a competent tissue-primed biotherapy.

YAP inhibition enhances the differentiation of functional stem cell-derived insulin-producing \u03b2 cells

Stem cell-derived insulin-producing beta cells (SC-β) offer an inexhaustible supply of functional β cells for cell replacement therapies and disease modeling for diabetes. While successful directed differentiation protocols for this cell type have been described, the mechanisms controlling its differentiation and function are not fully understood. Here we report that the Hippo pathway controls the proliferation and specification of pancreatic progenitors into the endocrine lineage. Downregulation of YAP, an effector of the pathway, enhances endocrine progenitor differentiation and the generation of SC-β cells with improved insulin secretion. A chemical inhibitor of YAP acts as an inducer of endocrine differentiation and reduces the presence of proliferative progenitor cells. Conversely, sustained activation of YAP results in impaired differentiation, blunted glucose-stimulated insulin secretion, and increased proliferation of SC-β cells. Together these results support a role for YAP in controlling the self-renewal and differentiation balance of pancreatic progenitors and limiting endocrine differentiation in vitro.

Direct differentiation of bone marrow mononucleated cells into insulin producing cells using pancreatic \u03b2-cell-derived components

Transplantation of stem cell-derived insulin producing cells (IPCs) has been proposed as an alternative to islet transplantation for the treatment of diabetes mellitus. However, current IPC differentiation protocols are focused on generating functional cells from the pluripotent stem cells and tend to rely on multistep, long-term exposure to various exogenous factors. In this study, we addressed the observation that under stress, pancreatic β-cells release essential components that direct the differentiation of the bone marrow nucleated cells (BMNCs) into IPCs. Without any supplementation with known differentiation-inducing factors, IPCs can be generated from BMNCs by in vitro priming for 6 days with conditioned media (CM) from the β-cells. In vitro primed BMNCs expressed the β-cell-specific transcription factors, as well as insulin, and improved hyperglycemia and glucose intolerance after transplantation into the streptozotocin-induced diabetic mice. Furthermore, we have found that components of the CM which trigger the differentiation were enclosed by or integrated into micro particles (MPs), rather than being secreted as soluble factors. Identification of these differentiation-directing factors might enable us to develop novel technologies required for the production of clinically applicable IPCs.

The expression of cytochrome P4502J2 gene and 14, 15 epoxyeicosatrienoic acid level influence the amount of insulin secreted from human mesenchymal stem cell-derived insulin-producing cells

BackgroundInsulin-producing cells differentiated from human mesenchymal stem cells demonstrate limited glucose-stimulated insulin secretion. Cytochrome P450 2J2 and its product epoxyeicosatrienoic acids regulate β-cell function in the human pancreas. The aim of this study is to explore the expression pattern of cytochrome P450 2J2 gene and 14, 15 epoxyeicosatrienoic level along the differentiation of human bone marrow-derived mesenchymal stem cells into insulin-producing cells.ResultsThe differentiated insulin-producing cells express high levels of pancreatic duodenal homeobox-1 and insulin gene mRNA. It secretes increasing amounts of C-peptide in response to increasing glucose concentrations than undifferentiated cells. The differentiated insulin-producing cells were found to express reduced amounts of cytochrome P450 2J2 gene mRNA and significant low level of 14, 15 epoxyeicosatrienoic acid than the undifferentiated cells. A strong positive correlation between 14, 15 epoxyeicosatrienoic concentrations and C-peptide released from the differentiated insulin-producing cells was noticed.ConclusionsCytochrome P4502J2 and its product 14, 15 epoxyeicosatrienoic might affect insulin secretion from differentiated insulin-producing cells.