Targeting β-cell dedifferentiation and transdifferentiation: opportunities and challenges

Research advances in understanding crosstalk between organs and pancreatic β-cell dysfunction

Obesity has increased dramatically worldwide. Being overweight or obese can lead to various conditions, including dyslipidaemia, hypertension, glucose intolerance and metabolic syndrome (MetS), which may further lead to type 2 diabetes mellitus (T2DM). Previous studies have identified a link between β-cell dysfunction and the severity of MetS, with multiple organs and tissues affected. Identifying the associations between pancreatic β-cell dysfunction and organs is critical. Research has focused on the interaction between the liver, gut and pancreatic β-cells. However, the mechanisms and related core targets are still not perfectly elucidated. The aims of this review were to summarize the mechanisms of β-cell dysfunction and to explore the potential pathogenic pathways and targets that connect the liver, gut, adipose tissue, muscle, and brain to pancreatic β-cell dysfunction.

Targeting β-Cell Plasticity: A Promising Approach for Diabetes Treatment

The β-cells within the pancreas play a pivotal role in insulin production and secretion, responding to fluctuations in blood glucose levels. However, factors like obesity, dietary habits, and prolonged insulin resistance can compromise β-cell function, contributing to the development of Type 2 Diabetes (T2D). A critical aspect of this dysfunction involves β-cell dedifferentiation and transdifferentiation, wherein these cells lose their specialized characteristics and adopt different identities, notably transitioning towards progenitor or other pancreatic cell types like α-cells. This process significantly contributes to β-cell malfunction and the progression of T2D, often surpassing the impact of outright β-cell loss. Alterations in the expressions of specific genes and transcription factors unique to β-cells, along with epigenetic modifications and environmental factors such as inflammation, oxidative stress, and mitochondrial dysfunction, underpin the occurrence of β-cell dedifferentiation and the onset of T2D. Recent research underscores the potential therapeutic value for targeting β-cell dedifferentiation to manage T2D effectively. In this review, we aim to dissect the intricate mechanisms governing β-cell dedifferentiation and explore the therapeutic avenues stemming from these insights.

Among Other Tissues, Short-Term Garlic Oral Treatment Incrementally Improves Indicants of Only Pancreatic Islets of Langerhans Histology and Insulin mRNA Transcription and Synthesis in Diabetic Rats

BACKGROUND

The source, mRNA transcription, and synthesis of insulin in the pancreas, in addition to the bile duct and liver, in streptozotocin (STZ)-induced diabetic rats (DR) in response to garlic oral treatment are not yet clear.

OBJECTIVE

This study investigated the accumulative effects of continued garlic oral treatment on changes in the pancreas, bile duct, and liver with regards to: 1-Insulin mRNA transcription, synthesis, and concentration in relation to changes in serum insulin (SI); 2-Insulinogenic cells insulin intensity and distribution, proliferation, and morphology.

METHOD

Fasting blood glucose (FBG) and insulin concentration in serum and pancreas (PI) and sources and mRNA transcription in the pancreas, bile duct, and liver in normal rats given normal saline (NR-NS) and DR given either NS (DR-NS) or garlic extract (DR-GE) before and after 1, 4, and 8 weeks of oral treatment were examined.

RESULTS

Compared to NR-NS, DR-NS showed a significant increase in FBG and reductions in SI and PI and deterioration in islets histology, associated pancreatic insulin numerical intensities, and mRNA transcription. However, compared to DR-NS, the targeted biochemical, histological, and genetic variables of DR-GE were significantly and incrementally improved as garlic treatment continued. Insulin or its indicators were not detected either in the bile duct or the liver in DR-GE.

CONCLUSIONS

8 weeks of garlic oral treatment is enough to incrementally restore only pancreatic islets of Langerhans insulin intensity and insulinogenic cells proliferation, morphology, and distribution. These indices were associated with enhanced pancreatic insulin mRNA transcription and synthesis. Eight weeks of garlic treatment were not enough to stimulate insulinogenesis in either the bile duct or the liver.

Harnessing beta cell regeneration biology for diabetes therapy

The pandemic scale of diabetes mellitus is alarming, its complications remain devastating, and current treatments still pose a major burden on those affected and on the healthcare system as a whole. As the disease emanates from the destruction or dysfunction of insulin-producing pancreatic β-cells, a real cure requires their restoration and protection. An attractive strategy is to regenerate β-cells directly within the pancreas; however, while several approaches for β-cell regeneration have been proposed in the past, clinical translation has proven challenging. This review scrutinizes recent findings in β-cell regeneration and discusses their potential clinical implementation. Hereby, we aim to delineate a path for innovative, targeted therapies to help shift from 'caring for' to 'curing' diabetes.

Pancreatic β-cell failure, clinical implications, and therapeutic strategies in type 2 diabetes

ABSTRACT

Pancreatic β-cell failure due to a reduction in function and mass has been defined as a primary contributor to the progression of type 2 diabetes (T2D). Reserving insulin-producing β-cells and hence restoring insulin production are gaining attention in translational diabetes research, and β-cell replenishment has been the main focus for diabetes treatment. Significant findings in β-cell proliferation, transdifferentiation, pluripotent stem cell differentiation, and associated small molecules have served as promising strategies to regenerate β-cells. In this review, we summarize current knowledge on the mechanisms implicated in β-cell dynamic processes under physiological and diabetic conditions, in which genetic factors, age-related alterations, metabolic stresses, and compromised identity are critical factors contributing to β-cell failure in T2D. The article also focuses on recent advances in therapeutic strategies for diabetes treatment by promoting β-cell proliferation, inducing non-β-cell transdifferentiation, and reprograming stem cell differentiation. Although a significant challenge remains for each of these strategies, the recognition of the mechanisms responsible for β-cell development and mature endocrine cell plasticity and remarkable advances in the generation of exogenous β-cells from stem cells and single-cell studies pave the way for developing potential approaches to cure diabetes.

Biochemical pancreatic β-cell lineage reprogramming: Various cell fate shifts

The incidence of pancreatic diseases has been continuously rising in recent years. Thus, research on pancreatic regeneration is becoming more popular. Chronic hyperglycemia is detrimental to pancreatic β-cells, leading to impairment of insulin secretion which is the main hallmark of pancreatic diseases. Obtaining plenty of functional pancreatic β-cells is the most crucial aspect when studying pancreatic biology and treating diabetes. According to the International Diabetes Federation, diabetes has become a global epidemic, with about 3 million people suffering from diabetes worldwide. Hyperglycemia can lead to many dangerous diseases, including amputation, blindness, neuropathy, stroke, and cardiovascular and kidney diseases. Insulin is widely used in the treatment of diabetes; however, innovative approaches are needed in the academic and preclinical stages. A new approach aims at synthesizing patient-specific functional pancreatic β-cells. The present article focuses on how cells from different tissues can be transformed into pancreatic β-cells.

Challenges of CRISPR/Cas-Based Cell Therapy for Type 1 Diabetes: How Not to Engineer a "Trojan Horse"

Type 1 diabetes mellitus (T1D) is an autoimmune disease caused by the destruction of insulin-producing β-cells in the pancreas by cytotoxic T-cells. To date, there are no drugs that can prevent the development of T1D. Insulin replacement therapy is the standard care for patients with T1D. This treatment is life-saving, but is expensive, can lead to acute and long-term complications, and results in reduced overall life expectancy. This has stimulated the research and development of alternative treatments for T1D. In this review, we consider potential therapies for T1D using cellular regenerative medicine approaches with a focus on CRISPR/Cas-engineered cellular products. However, CRISPR/Cas as a genome editing tool has several drawbacks that should be considered for safe and efficient cell engineering. In addition, cellular engineering approaches themselves pose a hidden threat. The purpose of this review is to critically discuss novel strategies for the treatment of T1D using genome editing technology. A well-designed approach to β-cell derivation using CRISPR/Cas-based genome editing technology will significantly reduce the risk of incorrectly engineered cell products that could behave as a "Trojan horse".

Generation of β-like cell subtypes from differentiated human induced pluripotent stem cells in 3D spheroids

Since the identification of four different pancreatic β-cell subtypes and bi-hormomal cells playing a role in the diabetes pathogenesis, the search for in vitro models that mimics such cells heterogeneity became a key priority in experimental and clinical diabetology. We investigated the potential of human induced pluripotent stem cells to lead to the development of the different β-cells subtypes in honeycomb microwell-based 3D spheroids. The glucose-stimulated insulin secretion confirmed the spheroids functionality. Then, we performed a single cell RNA sequencing of the spheroids. Using a knowledge-based analysis with a stringency on the pancreatic markers, we extracted the β-cells INS+/UCN3+ subtype (11%; β1-like cells), the INS+/ST8SIA1+/CD9- subtype (3%, β3-like cells) and INS+/CD9+/ST8SIA1-subtype (1%; β2-like cells) consistently with literature findings. We did not detect the INS+/ST8SIA1+/CD9+ cells (β4-like cells). Then, we also identified four bi-hormonal cells subpopulations including δ-like cells (INS+/SST+, 6%), γ-like cells (INS+/PPY+, 3%), α-like-cells (INS+/GCG+, 6%) and ε-like-cells (INS+/GHRL+, 2%). Using data-driven clustering, we extracted four progenitors' subpopulations (with the lower level of INS gene) that included one population highly expressing inhibin genes (INHBA+/INHBB+), one population highly expressing KCNJ3+/TPH1+, one population expressing hepatocyte-like lineage markers (HNF1A+/AFP+), and one population expressing stem-like cell pancreatic progenitor markers (SOX2+/NEUROG3+). Furthermore, among the cycling population we found a large number of REST+ cells and CD9+ cells (CD9+/SPARC+/REST+). Our data confirm that our differentiation leads to large β-cell heterogeneity, which can be used for investigating β-cells plasticity under physiological and pathophysiological conditions.

Hepatic insulin synthesis increases in rat models of diabetes mellitus type 1 and 2 differently

Insulin-positive (+) cells (IPCs), detected in multiple organs, are of great interest as a probable alternative to ameliorate pancreatic beta-cells dysfunction and insulin deficiency in diabetes. Liver is a potential source of IPCs due to it common embryological origin with pancreas. We previously demonstrated the presence of IPCs in the liver of healthy and diabetic rats, but detailed description and analysis of the factors, which potentially can induced ectopic hepatic expression of insulin in type 1 (T1D) and type 2 diabetes (T2D), were not performed. In present study we evaluate mass of hepatic IPCs in the rat models of T1D and T2D and discuss factors, which may stimulate it generation: glycaemia, organ injury, involving of hepatic stem/progenitor cell compartment, expression of transcription factors and inflammation. Quantity of IPCs in the liver was up by 1.7-fold in rats with T1D and 10-fold in T2D compared to non-diabetic (ND) rats. We concluded that ectopic hepatic expression of insulin gene is activated by combined action of a number of factors, with inflammation playing a decision role.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic human embryonic stem cell-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional roles of many loci remain unexplored. Here, we engineered isogenic knockout human embryonic stem cell lines for 20 genes associated with T2D risk. We examined the impacts of each knockout on β cell differentiation, functions, and survival. We generated gene expression and chromatin accessibility profiles on β cells derived from each knockout line. Analyses of T2D-association signals overlapping HNF4A-dependent ATAC peaks identified a likely causal variant at the FAIM2 T2D-association signal. Additionally, the integrative association analyses identified four genes (CP, RNASE1, PCSK1N, and GSTA2) associated with insulin production, and two genes (TAGLN3 and DHRS2) associated with β cell sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental line and identified a single likely functional variant at each of 23 T2D-association signals.

Beyond Glucose: The Dual Assault of Oxidative and ER Stress in Diabetic Disorders

Diabetes mellitus, a prevalent global health concern, is characterized by hyperglycemia. However, recent research reveals a more intricate landscape where oxidative stress and endoplasmic reticulum (ER) stress orchestrate a dual assault, profoundly impacting diabetic disorders. This review elucidates the interplay between these two stress pathways and their collective consequences on diabetes. Oxidative stress emanates from mitochondria, where reactive oxygen species (ROS) production spirals out of control, leading to cellular damage. We explore ROS-mediated signaling pathways, which trigger β-cell dysfunction, insulin resistance, and endothelial dysfunction the quintessential features of diabetes. Simultaneously, ER stress unravels, unveiling how protein folding disturbances activate the unfolded protein response (UPR). We dissect the UPR's dual role, oscillating between cellular adaptation and apoptosis, significantly influencing pancreatic β-cells and peripheral insulin-sensitive tissues. Crucially, this review exposes the synergy between oxidative and ER stress pathways. ROS-induced UPR activation and ER stress-induced oxidative stress create a detrimental feedback loop, exacerbating diabetic complications. Moreover, we spotlight promising therapeutic strategies that target both stress pathways. Antioxidants, molecular chaperones, and novel pharmacological agents offer potential avenues for diabetes management. As the global diabetes burden escalates, comprehending the dual assault of oxidative and ER stress is paramount. This review not only unveils the intricate molecular mechanisms governing diabetic pathophysiology but also advocates a holistic therapeutic approach. By addressing both stress pathways concurrently, we may forge innovative solutions for diabetic disorders, ultimately alleviating the burden of this pervasive health issue.

Cell Transdifferentiation: A Challenging Strategy with Great Potential

With the discovery and development of somatic cell nuclear transfer, cell fusion, and induced pluripotent stem cells, cell transdifferentiation research has presented unique advantages and stimulated a heated discussion worldwide. Cell transdifferentiation is a phenomenon by which a cell changes its lineage and acquires the phenotype of other cell types when exposed to certain conditions. Indeed, many adult stem cells and differentiated cells were reported to change their phenotype and transform into other lineages. This article reviews the differentiation of stem cells and classification of transdifferentiation, as well as the advantages, challenges, and prospects of cell transdifferentiation. This review discusses new research directions and the main challenges in the use of transdifferentiation in human cells and molecular replacement therapy. Overall, such knowledge is expected to provide a deep understanding of cell fate and regulation, which can change through differentiation, dedifferentiation, and transdifferentiation, with multiple applications.

Obese mothers supplemented with melatonin during gestation and lactation ameliorate the male offspring's pancreatic islet cellular composition and beta-cell function

Melatonin supplementation to obese mothers during gestation and lactation might benefit the pancreatic islet cellular composition and beta-cell function in male offspring adulthood. C57BL/6 females (mothers) were assigned to two groups (n = 20/each) based on their consumption in control (C 17% kJ as fat) or high-fat diet (HF 49% kJ as fat). Mothers were supplemented with melatonin (Mel) (10 mg/kg daily) during gestation and lactation, or vehicle, forming the groups (n = 10/each): C, CMel, HF, and HFMel. The male offspring were studied, considering they only received the C diet after weaning until three months old. The HF mothers and their offspring showed higher body weight, glucose intolerance, insulin resistance, and low insulin sensitivity than the C ones. However, HFMel mothers and their offspring showed improved glucose metabolism and weight loss than the HF ones. Also, the offspring's higher expressions of pro-inflammatory markers and endoplasmic reticulum (ER) stress were observed in HF but reduced in HFMel. Contrarily, antioxidant enzymes were less expressed in HF but improved in HFMel. In addition, HF showed increased beta-cell mass and hyperinsulinemia but diminished in HFMel. Besides, the beta-cell maturity and identity gene expressions diminished in HF but enhanced in HFMel. In conclusion, obese mothers supplemented with melatonin benefit their offspring's islet cell remodeling and function. In addition, improving pro-inflammatory markers, oxidative stress, and ER stress resulted in better glucose and insulin levels control. Consequently, pancreatic islets and functioning beta cells were preserved in the offspring of obese mothers supplemented with melatonin.

Pancreatic islet remodeling in cotadutide-treated obese mice

Obesity and type 2 diabetes mellitus (T2DM) cause morphofunctional alterations in pancreatic islet alpha and beta cells. Therefore, we hypothesize that the new GLP-1/Glucagon receptor dual agonist cotadutide may benefit islet cell arrangement and function. Twelve-week-old C57BL/6 male mice were fed a control diet (C, 10 % kJ fat) or a high-fat diet (HF, 50 % kJ fat) for ten weeks. Then, the animals were divided into four groups for an additional 30 days and daily treated with subcutaneous cotadutide (30 nmol/kg) or vehicle: C, CC (control+cotadutide), HF, and HFC (high-fat+cotadutide). Cotadutide led to weight loss and reduced insulin resistance in the HFC group, increasing insulin receptor substrate 1 and solute carrier family 2 gene expressions in isolated islets. Also, cotadutide enhanced transcriptional factors related to islet cell transdifferentiation, decreasing aristaless-related homeobox and increasing the paired box 4 and 6, pancreatic and duodenal homeobox 1, v-maf musculoaponeurotic fibrosarcoma oncogene family protein A, neurogenin 3, and neurogenic differentiation 1. In addition, cotadutide improved the proliferating cell nuclear antigen, NK6 homeobox 1, B cell leukemia/lymphoma 2, but lessening caspase 3. Furthermore, cotadutide mitigated the endoplasmic reticulum (ER) stress-responsive genes, reducing transcription factor 4, DNA-damage-inducible transcript 3, and growth arrest and DNA-damage-inducible 45. In conclusion, our data demonstrated significant beneficial actions of cotadutide in DIO mice, such as weight loss, glycemic control, and insulin resistance improvement. In addition, cotadutide counteracted the pathological adaptive cellular arrangement of the pancreatic islet in obese mice, improving the markers of the transdifferentiating pathway, proliferation, apoptosis, and ER stress.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic hESC-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional role of many loci has remained unexplored. In this study, we engineered isogenic knockout human embryonic stem cell (hESC) lines for 20 genes associated with T2D risk. We systematically examined β-cell differentiation, insulin production and secretion, and survival. We performed RNA-seq and ATAC-seq on hESC-β cells from each knockout line. Analyses of T2D GWAS signals overlapping with HNF4A-dependent ATAC peaks identified a specific SNP as a likely causal variant. In addition, we performed integrative association analyses and identified four genes ( CP, RNASE1, PCSK1N and GSTA2 ) associated with insulin production, and two genes ( TAGLN3 and DHRS2 ) associated with sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental hESC line, to identify a single likely functional variant at each of 23 T2D GWAS signals.

Promoting β-cells function by the recapitulation of in vivo microenvironmental differentiation signals

The study aims to transdifferentiate rat bone marrow-derived mesenchymal stem cells (BM-MSCs) more efficiently into islet-like cells and encapsulate and transplant them with vital properties like stability, proliferation, and metabolic activity enhanced for the treatment of T1DM. Trans-differentiation of BM-MCs into islet-like cells induced by high glucose concentration combined with Nicotinamide, ꞵ-Mercaptoethanol, ꞵ-Cellulin, and IGF-1. Glucose challenge assays and gene expression profiles were used to determine functionality. Microencapsulation was performed using the vibrating nozzle encapsulator droplet method with a 1% alginate concentration. Encapsulated ꞵ-cells were cultured in a fluidized-bed bioreactor with 1850 μL/min fluid flow rates and a superficial velocity of 1.15 cm/min. The procedure was followed by transplanting transdifferentiated cells into the omentum of streptozotocin (STZ)-induced diabetic Wistar rats. Changes in weight, glucose, insulin, and C-peptide levels were monitored for 2 months after transplantation. PDX1, INS, GCG, NKx2.2, NKx6.1, and GLUT2 expression levels revealed the specificity of generated β-cells with higher viability (about 20%) and glucose sensitivity about twofold more. The encapsulated β-cells decreased the glucose levels in STZ-induced rats significantly (P < 0.05) 1 week after transplantation. Also, the weight and levels of insulin and C-peptide reached the control group. In contrast to the treated, the sham group displayed a consistent decline in weight and died when loss reached > 20% at day ~ 55. The coated cells secrete significantly higher amounts of insulin in response to glucose concentration changes. Enhanced viability and functionality of β-cells can be achieved through differentiation and culturing, a promising approach toward insulin therapy alternatives.

Nutritional strategies for intervention of diabetes and improvement of β-cell function

Diabetes mellitus, especially Type 2 diabetes (T2D), is caused by multiple factors including genetics, diets, and lifestyles. Diabetes is a chronic condition and is among the top 10 causes of death globally. Nutritional intervention is one of the most important and effective strategies for T2D management. It is well known that most of intervention strategies can lower blood glucose level and improve insulin sensitivity in peripheral tissues. However, the regulation of pancreatic β cells by dietary intervention is not well characterized. In this review, we summarized some of the commonly used nutritional methods for diabetes intervention. We then discussed the effects and the underlying mechanisms of nutritional intervention in improving the cell mass and function of pancreatic islet β cells. With emerging intervention strategies and in-depth investigation, we are expecting to have a better understanding about the effectiveness of dietary interventions in ameliorating T2D in the future.

Antioxidant Phytochemicals as Potential Therapy for Diabetic Complications

The global prevalence of diabetes continues to increase partly due to rapid urbanization and an increase in the aging population. Consequently, this is associated with a parallel increase in the prevalence of diabetic vascular complications which significantly worsen the burden of diabetes. For these diabetic vascular complications, there is still an unmet need for safe and effective alternative/adjuvant therapeutic interventions. There is also an increasing urge for therapeutic options to come from natural products such as plants. Hyperglycemia-induced oxidative stress is central to the development of diabetes and diabetic complications. Furthermore, oxidative stress-induced inflammation and insulin resistance are central to endothelial damage and the progression of diabetic complications. Human and animal studies have shown that polyphenols could reduce oxidative stress, hyperglycemia, and prevent diabetic complications including diabetic retinopathy, diabetic nephropathy, and diabetic peripheral neuropathy. Part of the therapeutic effects of polyphenols is attributed to their modulatory effect on endogenous antioxidant systems. This review attempts to summarize the established effects of polyphenols on endogenous antioxidant systems from the literature. Moreover, potential therapeutic strategies for harnessing the potential benefits of polyphenols for diabetic vascular complications are also discussed.

Restoring tolerance to β-cells in Type 1 diabetes: Current and emerging strategies

Type 1 diabetes (T1D) results from insulin insufficiency due to islet death and dysfunction following T cell-mediated autoimmune attack. The technical feasibility of durable, functional autologous islet restoration is progressing such that it presents the most likely long-term cure for T1D but cannot succeed without the necessary counterpart of clinically effective therapeutic strategies that prevent grafted islets' destruction by pre-existing anti-islet T cells. While advances have been made in broad immunosuppression to lower off-target effects, the risk of opportunistic infections and cancers remains a concern, especially for well-managed T1D patients. Current immunomodulatory strategies in development focus on autologous Treg expansion, treatments to decrease antigen presentation and T effector (Teff) activation, and broad depletion of T cells with or without hematopoietic stem cell transplants. Emerging strategies harnessing the intensified DNA damage response present in expanding T cells, exacerbating their already high sensitivity to apoptosis to abate autoreactive Teff cells.

Expression Profiling of Pdx1, Ngn3, and MafA in the Liver and Pancreas of Recovering Streptozotocin-Induced Diabetic Rats

Studies in animal diabetic models have demonstrated the possibility of islet regeneration through treatment with natural extracts, such as Allium sativum (garlic). This study aimed to investigate the effect of garlic extract (GE) on the expression of three genes (Ngn3, Pdx1, and MafA) in the pancreas and liver of diabetic rats. Thirty-two rats were divided into two groups, streptozotocin (STZ)-induced diabetic rats (n = 16) and healthy rats (n = 16). Both groups were subdivided into GE-treated (n = 8), and those administered 0.9% normal saline (NS) (n = 8) for 1 week (n = 4) and 8 weeks (n = 4). In the pancreas of diabetic rats treated with GE for 1 week, all three genes, Ngn3, Pdx1, and MafA, were significantly upregulated (p ≤ 0.01, p ≤ 0.05, and p ≤ 0.001, respectively) when compared to diabetic rats treated with NS only. However, after eight weeks of GE treatment, the expression of all three genes decreased as blood insulin increased. In the liver, only Pdx1 expression significantly (p ≤ 0.05) increased after 8 weeks. The significant expression of Ngn3, Pdx1, and MafA in the pancreas by week 1 may have induced the maturation of juvenile β-cells, which escaped the effects of STZ and caused an increase in serum insulin.

Role of Polyamines and Hypusine in β Cells and Diabetes Pathogenesis

The polyamines—putrescine, spermidine, and spermine—are polycationic, low molecular weight amines with cellular functions primarily related to mRNA translation and cell proliferation. Polyamines partly exert their effects via the hypusine pathway, wherein the polyamine spermidine provides the aminobutyl moiety to allow posttranslational modification of the translation factor eIF5A with the rare amino acid hypusine (hydroxy putrescine lysine). The “hypusinated” eIF5A (eIF5A^hyp) is considered to be the active form of the translation factor necessary for the translation of mRNAs associated with stress and inflammation. Recently, it has been demonstrated that activity of the polyamines-hypusine circuit in insulin-producing islet β cells contributes to diabetes pathogenesis under conditions of inflammation. Elevated levels of polyamines are reported in both exocrine and endocrine cells of the pancreas, which may contribute to endoplasmic reticulum stress, oxidative stress, inflammatory response, and autophagy. In this review, we have summarized the existing research on polyamine-hypusine metabolism in the context of β-cell function and diabetes pathogenesis.