The Nexus of Stem Cell-Derived Beta-Cells and Genome Engineering

Harnessing cellular therapeutics for type 1 diabetes mellitus: progress, challenges, and the road ahead

Type 1 diabetes mellitus (T1DM) is a growing global health concern that affects approximately 8.5 million individuals worldwide. T1DM is characterized by an autoimmune destruction of pancreatic β cells, leading to a disruption in glucose homeostasis. Therapeutic intervention for T1DM requires a complex regimen of glycaemic monitoring and the administration of exogenous insulin to regulate blood glucose levels. Advances in continuous glucose monitoring and algorithm-driven insulin delivery devices have improved the quality of life of patients. Despite this, mimicking islet function and complex physiological feedback remains challenging. Pancreatic islet transplantation represents a potential functional cure for T1DM but is hindered by donor scarcity, variability in harvested cells, aggressive immunosuppressive regimens and suboptimal clinical outcomes. Current research is directed towards generating alternative cell sources, improving transplantation methods, and enhancing cell survival without chronic immunosuppression. This Review maps the progress in cell replacement therapies for T1DM and outlines the remaining challenges and future directions. We explore the state-of-the-art strategies for generating replenishable β cells, cell delivery technologies and local targeted immune modulation. Finally, we highlight relevant animal models and the regulatory aspects for advancing these technologies towards clinical deployment.

Stem cells differentiation into insulin-producing cells (IPCs): recent advances and current challenges

Type 1 diabetes mellitus (T1D) is a chronic disease characterized by an autoimmune destruction of insulin-producing β-pancreatic cells. Although many advances have been achieved in T1D treatment, current therapy strategies are often unable to maintain perfect control of glycemic levels. Several studies are searching for new and improved methodologies for expansion of β-cell cultures in vitro to increase the supply of these cells for pancreatic islets replacement therapy. A promising approach consists of differentiation of stem cells into insulin-producing cells (IPCs) in sufficient number and functional status to be transplanted. Differentiation protocols have been designed using consecutive cytokines or signaling modulator treatments, at specific dosages, to activate or inhibit the main signaling pathways that control the differentiation of induced pluripotent stem cells (iPSCs) into pancreatic β-cells. Here, we provide an overview of the current approaches and achievements in obtaining stem cell-derived β-cells and the numerous challenges, which still need to be overcome to achieve this goal. Clinical translation of stem cells-derived β-cells for efficient maintenance of long-term euglycemia remains a major issue. Therefore, research efforts have been directed to the final steps of in vitro differentiation, aiming at production of functional and mature β-cells and integration of interdisciplinary fields to generate efficient cell therapy strategies capable of reversing the clinical outcome of T1D.

Cell therapy research for Diabetes: Pancreatic β cell differentiation from pluripotent stem cells

Human pluripotent stem cells (PSCs), both embryonic and induced pluripotent stem cells (iPSCs), have been differentiated into pancreatic β isletsin vitrofor more than a decade. The idea is to get enough β cells for cell transplantation for diabetics. Finding a standard cell therapy for diabetes is essential because of the logarithmic increase in the global population of people with diabetes and the insufficient availability of the human cadaveric pancreas. Moreover, with better insights into developmental biology, thein vitroβ cell differentiation protocols have depended on thein vivoβ cell organogenesis. Various protocols for pancreatic β cell differentiation have been developed. Such protocols are based on the modulation of cell signalling pathways with growth factors, small molecules, RNAi approaches, directed differentiation using transcription factors, genome editing. Growth factor free differentiation protocols, epigenetic modulations, 3D differentiation approaches, and encapsulation strategies have also been reported for better glycemic control and endocrine modulations. Here, we have reviewed various aforementionedin vitroβ cell differentiation protocols from human PSCs, their respective comparisons, challenges, past, present, and future. The literature has been reviewed primarily from PubMed from the year 2000 till date using the mentioned keywords.

Applications of iPSC-derived beta cells from patients with diabetes

Improved stem cell-derived pancreatic islet (SC-islet) differentiation protocols robustly generate insulin-secreting β cells from patient induced pluripotent stem cells (iPSCs). These advances are enabling in vitro disease modeling studies and the development of an autologous diabetes cell replacement therapy. SC-islet technology elucidates key features of human pancreas development and diabetes disease progression through the generation of pancreatic progenitors, endocrine progenitors, and β cells derived from diabetic and nondiabetic iPSCs. Combining disease modeling with gene editing and next-generation sequencing reveals the impact of diabetes-causing mutations and diabetic phenotypes on multiple islet cell types. In addition, the supply of SC-islets, containing β and other islet cell types, is unlimited, presenting an opportunity for personalized medicine and overcoming several disadvantages posed by donor islets. This review highlights relevant studies involving iPSC-β cells and progenitors, encompassing new conclusions involving cells from patients with diabetes and the therapeutic potential of iPSC-β cells.

Improved differentiation protocols generate pancreatic islet from patient stem cells

Diabetic stem cell-derived islet studies identified key markers for cell function

Gene editing aims to address unmet needs for stem cell therapy field

Stem cell-derived islets are a promising source for diabetes stem cell therapy

Pancreas transplant versus islet transplant versus insulin pump therapy: in which patients and when?

PURPOSE OF REVIEW

The aim of the present review is to gather recent reports on the use of pancreas and islet transplantation and conventional insulin therapy for treating patients experiencing diabetes and its related complications. The present review directs attention to the current status, challenges and perspectives of these therapies and sheds light on potential future cellular therapies.

RECENT FINDINGS

The risks and benefits of diabetes treatment modalities continue to evolve, altering the risk versus benefit calculation for patients. As continuous subcutaneous insulin infusion and monitoring technologies demonstrate increasing effectiveness in achieving better diabetes control and reducing hypoglycemia frequency, so are pancreas and islet transplantation improving and becoming more effective and safer. Both beta-cell replacement therapies, however, are limited by a dependence on immunosuppression and a shortage of cadaver donors, restricting more widespread and safer deployment. Based on the effectiveness of clinical beta-cell replacement for lengthening lifespan and improving quality of life, scientists are aggressively investigating alternative cell sources, transplant platforms, and means of preventing immunological damage of transplanted cells to overcome these principle limitations.

SUMMARY

Essential goals of diabetes therapy are euglycemia, avoidance of hypoglycemia, and prevention or stabilization of end-organ damage. With these goals in mind, all therapeutic options should be considered.

Mesenchymal Stem Cells: A Trump Card for the Treatment of Diabetes?

The advent of the new revolutionary approach based on regenerative medicine is progressively reshaping the therapeutic scenario of many different diseases, such as cardiovascular diseases and immune diseases, with encouraging results. During the last 10 years, many studies have also proposed the use of mesenchymal stem cells (MSCs), adult stem cells with several interesting properties already used in different experimental models, for the treatment of diabetes, however, reporting conflicting outcomes. These reasons have given rise to a question: are these cells a real trump card for the biomedical field? Are they really able to outclass the traditional therapies, or at least able to give an advantage over them? In this review, we will discuss the most promising results obtained with MSCs for the treatment of diabetes and its complications, we will compare the different therapeutic treatments applied as well as the most likely mechanisms of action, and overall we will give an in-depth overview of the pros and the cons of the use of MSCs for the therapy of both type-1 and type-2 diabetes.

Mimicking nature-made beta cells: recent advances towards stem cell-derived islets

PURPOSE OF REVIEW

Stem cell-derived islets are likely to be useful as a future treatment for diabetes. However, the field has been limited in the ability to generate β-like cells with both phenotypic maturation and functional glucose-stimulated insulin secretion that is similar to primary human islets. The field must also establish a reliable method of delivering the cells to patients while promoting rapid in-vivo engraftment and function. Overcoming these barriers to β cell differentiation and transplantation will be key to bring this therapy to the clinic.

RECENT FINDINGS

The ability to generate stem cell-derived β-like cells capable of dynamic glucose-responsive insulin secretion, as well as β-like cells expressing key maturation genes has recently been demonstrated by several groups. Other groups have explored the potential of vascularized subcutaneous transplant sites, as well as endothelial cell co-transplant to support β cell survival and function following transplantation.

SUMMARY

The generation of stem cell-derived islets with dynamic glucose-responsive insulin secretion has brought the field closer to clinical translation, but there is still need for improving insulin content and secretory capacity, as well as understanding the factors affecting variable consistency and heterogeneity of the islet-like clusters. Other questions remain regarding how to address safety, immunogenicity and transplantation site moving forward.

Nanotechnology in cell replacement therapies for type 1 diabetes

Islet transplantation is a promising long-term, compliance-free, complication-preventing treatment for type 1 diabetes. However, islet transplantation is currently limited to a narrow set of patients due to the shortage of donor islets and side effects from immunosuppression. Encapsulating cells in an immunoisolating membrane can allow for their transplantation without the need for immunosuppression. Alternatively, "open" systems may improve islet health and function by allowing vascular ingrowth at clinically attractive sites. Many processes that enable graft success in both approaches occur at the nanoscale level-in this review we thus consider nanotechnology in cell replacement therapies for type 1 diabetes. A variety of biomaterial-based strategies at the nanometer range have emerged to promote immune-isolation or modulation, proangiogenic, or insulinotropic effects. Additionally, coating islets with nano-thin polymer films has burgeoned as an islet protection modality. Materials approaches that utilize nanoscale features manipulate biology at the molecular scale, offering unique solutions to the enduring challenges of islet transplantation.

Islet encapsulation

Review of emerging advances and persisting challenges in the engineering and translation of islet encapsulation technologies.