Kacie Kerlee

Introduction. Type 1 Diabetes Mellitus (T1DM) is an autoimmune disease resulting in the destruction of beta-cells within the islet of Langerhans of the pancreas via macrophages and self-reactive CD4+ & CD8+ T-cells.^{2, 6, 7} This damage to the beta-cells results in a lack of insulin and thus hyperglycemia that can further lead to complications such as neuropathy, blindness, and kidney failure.^3,4,8,9 The most popular current treatment is insulin replacement therapy, but it doesn’t offer patients a cure and is a time consuming process.⁴ Pancreas transplantation offers T1DM patients a cure, but due to limited cadaver sources and risks of immune rejection it is not as commonly utilized.^1,2,9 In efforts to minimize the potential health risks while providing a cure, researchers have begun testing various methods of taking a T1DM patient’s own cells to form human induced pluripotent stem cells (HiPSC) to then regenerate functioning beta-cells. ^{1-6, 8-10} Methods. Studies utilized skin cells of patients with T1DM and induced pluripotency via a lentivirus or transgene-free reprogramming with enzymatic dissociation. All studies utilized a culture manipulation method to differentiate the cells into pancreatic beta-cells. One study added a demethylation step.³ Most of the studies utilized a cell culture plate to grow the cells, but one used a polyethersulfone nanofibrous scaffold to grow the cells on instead.⁴ Differentiated beta-cells were then injected into mice models to determine teratoma growth and cell function. Data was analyzed via immunofluorescent staining, PCR, hormone assays, and tissue samples. Results. Studies that utilized transgene-free reprogramming with enzymatic dissociation had less teratoma growth than those utilizing lentivirus pluripotency induction.^1,5 Trials using a 7 step differentiation process compared to a 5 step process had cells with a faster response to glucose and lower incidence of teratomas.^1,2 When pancreatic-endoderm cells were demethylated, there was a lower incidence of polyhormonal cells & teratomas and a greater production of insulin granules.³ When HiPSCs were grown on a polyethersulfone nanofibrous scaffold, there was greater expression of pancreatic beta-cell markers and the beta-cells were more responsive to glucose stimulation. However, these cells weren’t tested on a mice model.⁴ Conclusion. Utilizing a patient’s own cells to regenerate pancreatic beta-cells shows potential for a cure comparable to a pancreas transplant without the risk of immune rejection. A variety of studies have been conducted to find the optimal procedure to transform the patient’s cells into beta-cells, with each study slightly altering or adding to a basic differentiation process. The improved outcomes of the new beta-cells in each study leads one to consider combining the different processes into one large procedure.

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