Search Results (575)

Ficus deltoidea Jack (Moraceae), locally known as Mas Cotek, is a medicinal plant traditionally used throughout Southeast Asia for the management of diabetes mellitus. This review summarises the available evidence on the antidiabetic properties of F. deltoidea based on eleven in vitro, nine in vivo and one clinical study identified through a structured literature search. In vitro investigations show that F. deltoidea inhibits α-glucosidase and α-amylase, stimulates insulin secretion in pancreatic β-cells via both K⁺-ATP channel-dependent and -independent pathways, enhances glucose uptake in hepatocytes and adipocytes, promotes adiponectin secretion and inhibits protein tyrosine phosphatase 1B (PTP1B). Vitexin and isovitexin, the predominant C-glycosyl flavonoids in F. deltoidea leaves, appear to be the main bioactive compounds responsible for these effects. Meanwhile, in vivo studies in streptozotocin-induced diabetic rodents report dose-dependent reductions in fasting blood glucose, improved glucose tolerance, restoration of pancreatic islet architecture, modulation of hepatic gluconeogenic and glucose-metabolic genes, and protection against diabetic nephropathy and bone loss. Inter-varietal differences in chemical composition and biological activity were observed, with var. trengganuensis and var. intermedia reported as the most active. The only available clinical trial in adults with prediabetes (1000 mg/day for 8 weeks) showed a reduction in LDL and total cholesterol but no significant change in fasting blood glucose or insulin. The discrepancy between preclinical and clinical findings highlights the need for standardised extracts, pharmacokinetic studies and adequately powered clinical trials in patients with established type 2 diabetes mellitus. Full article

Inflammatory and oxidative stress within the pancreatic islet microenvironment can alter insulin-derived peptides and generate neoepitopes that may reshape autoreactive T cell recognition in type 1 diabetes (T1D). One such modification, C19S, represents a cysteine-to-serine substitution at position 19 of the insulin B-chain and has recently been identified among human leukocyte antigen class II (HLA-II)-associated insulin neoepitopes recognized by autoreactive CD4+ T cells. Although the biological relevance of C19S has been determined, the molecular features that may distinguish C19S-specific T cell receptor (TCR) engagement from native insulin recognition remain incompletely defined. Here, we used comparative protein–protein docking, molecular dynamics (MD) simulations, interface-contact analysis, conformational landscape analysis, and binding-energy calculations to examine TCR engagement of human leukocyte antigen DQ8 (HLA-DQ8) presenting either native insulin peptide or the corresponding C19S insulin peptide. Initial modeling indicated that both peptide-HLA-DQ8 complexes were compatible with TCR-bound ternary complex formation. However, the C19S-containing complex was predicted to exhibit altered peptide-centered dynamics, changes in peptide backbone presentation, and reorganization of both TCR-peptide and TCR-HLA-DQ8 contacts. Comparative molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) and molecular mechanics generalized Born surface area (MM/GBSA) analyses further suggested a distinct calculated energetic profile under the applied modeling conditions for the C19S-containing complex, with residue-level decomposition localizing energetic differences to selected interface hotspots. Together, these findings provide a molecular framework for generating hypotheses about how C19S may reshape the HLA-DQ8-presented insulin recognition surface, with implications for future experimental studies of autoreactive CD4+ T cell recognition and antigen-specific tolerogenic strategies in T1D. Full article

Apolipoprotein A-IV (ApoA-IV) is a glycoprotein secreted by the small intestine to regulate lipid metabolism and satiety. Its role in insulin-independent glucose homeostasis remains largely unknown. In this study, we demonstrate that intestinal ApoA-IV overexpression significantly attenuates diet-induced obesity and hyperglycemia following severe β-cell loss. Over a 20-week high-fat diet challenge, ApoA-IV transgenic (ApoA-IV-Tg) mice maintained significantly lower adiposity than wild-type controls, driven by elevated energy expenditure and fatty acid oxidation rather than reduced caloric intake. Beyond weight maintenance, ApoA-IV maintained excellent systemic glycemic control and enhanced peripheral insulin sensitivity. Most notably, ApoA-IV significantly attenuated hyperglycemia following streptozotocin (STZ)-induced β-cell ablation, maintaining glucose stability despite severe insulin deficiency. Mechanistically, this protection results from a blunted glucagon response and the subsequent suppression of the hepatic pCREB-G6Pase gluconeogenic signaling pathway. In vitro evidence confirms that ApoA-IV directly inhibits pancreatic α-cell glucagon secretion through an LDL receptor-related protein 1 (LRP1)-dependent pathway, reinforced by the precise co-localization of LRP1 and glucagon in pancreatic islets. Furthermore, ApoA-IV-Tg mice were protected from the STZ-induced corticosterone surge and systemic lipolysis. Collectively, these findings establish the ApoA-IV–LRP1 signaling axis as a potent metabolic switch, providing a promising insulin-independent strategy for managing obesity and diabetes. Full article

Background: Impaired insulin secretion by pancreatic beta cells drives chronic hyperglycemia, which characterizes type 2 diabetes mellitus. The mechanosensitive ion channel Piezo2 has been implicated in various physiological processes. However, its expression and functional role in pancreatic endocrine cells remain poorly understood. Methods: We investigated the expression, cellular localization, and potential functional significance of Piezo2 in the pancreatic islets of mice fed normal- and high-fat diets (HFD) using molecular, immunohistochemical, and immunofluorescence approaches. Results: Piezo2 mRNA and protein expression were detected in rat pancreatic tissue and the pancreatic beta cell line INS-1 via polymerase chain reaction and Western blotting analyses. Hematoxylin and eosin staining and histopathological analysis were performed to determine the localization of Piezo2, insulin, and glucagon in the islets of Langerhans from mouse pancreas. Immunofluorescence revealed that Piezo2 colocalized with insulin, glucagon, pancreatic polypeptide (PP, a pancreatic cell marker), and insulin/PP (suggesting Ppy-lineage beta cells). Piezo2 expression is significantly reduced in islets from HFD-fed mice and downregulated under high glucose conditions in INS-1 cells. Stretch stimulation, with or without D-GsMTx4 (a Piezo2-specific inhibitor), enhanced glucose-stimulated insulin secretion, whereas ruthenium red (a non-specific Piezo channel inhibitor) did not alter the response to high glucose. Conclusions: These findings demonstrate Piezo2 expression in pancreatic islets and suggest that it is enriched in beta cells and Ppy-lineage beta cells, minority in alpha cells and is responsive to metabolic stress. Although Piezo2 may contribute to beta-cell adaptation, its role in insulin secretion remains unclear. Full article

It is unknown whether the glucagon-like peptide-1 (GLP-1) receptor agonists have a significant protective effect against acute islet injury. High mobility group box 1 (HMGB1) is a damage-associated molecular pattern (DAMP) molecule released from stressed or injured pancreatic β-cells, which triggers inflammatory responses through toll-like receptor 4 (TLR4) signaling. This study investigated the protective effect and mechanism of liraglutide on acute islet injury induced by low doses of streptozotocin (STZ). The results showed that liraglutide pretreatment preserved the structural integrity of pancreatic islets, improved insulin levels and glucose tolerance, and significantly reduced the incidence of diabetes in STZ-treated mice. Liraglutide was also found to inhibit STZ-induced release of HMGB1 and reduce the expression of TLR4 and inflammatory factors IFN-γ, IL-1β, and CXCL10. Moreover, administration of exogenous HMGB1 or antagonism of the GLP-1 receptor diminished liraglutide’s protective effects. These findings suggest that liraglutide has a strong protective effect on STZ-induced acute islet injury, most likely through the inhibition of HMGB1 release, which provides an experimental basis for the application of liraglutide as a protective agent for acute islet injury. Full article

Background/Objectives: Gamma-aminobutyric acid (GABA) is increasingly recognized as an important modulator of pancreatic beta-cell function, but the mechanisms by which it regulates intracellular Ca²⁺ oscillations and coordinated beta-cell activity remain insufficiently understood. The aim of this study was to investigate how GABA influences the amplitude, frequency, phase adjustment, entrainment, and synchronization of beta-cell Ca²⁺ oscillations. Methods: We developed a reduced ATP–Ca²⁺ oscillation model, based on established beta-cell oscillatory frameworks, and coupled it to the GABA-shunt subsystem derived from our previously established Dual Anaplerotic Model. The model incorporates explicit dynamics of cytosolic Ca²⁺, endoplasmic reticulum Ca²⁺, ATP, and a regulatory variable controlling Ca²⁺ influx, while the interstitial GABA signal is represented as a delayed feedback signal acting on cellular excitability. Single-cell and two-cell simulations were performed to analyze GABA-dependent oscillatory regulation and intercellular coupling. Results: The model reproduced key experimental observations under both control and GABA-deficient conditions, including reduced Ca²⁺-oscillation amplitude and a prolonged oscillation period when GABA production was suppressed. Mechanistically, GABA affected single-cell oscillations through two complementary pathways: metabolically, by modulating ATP production through PEP-related and TCA-related contributions linked to the GABA shunt, and as an interstitial/paracrine signal, by adjusting the phase of Ca²⁺ influx through fast and delayed inhibitory feedback. In the reduced two-cell model, delayed interstitial GABA signaling could phase-lock non-identical oscillators over finite ranges of parameter mismatch. When included as an additional weak effective term, electrical coupling broadened these ranges, consistent with a complementary interaction between GABA-mediated phase adjustment and established electrical coupling. Conclusions: GABA acts as a dual regulator of beta-cell dynamics, linking intracellular metabolism to Ca²⁺-oscillation patterning and promoting coordinated activity through intercellular phase adjustment. The model provides a mechanistic framework connecting GABA metabolism, ATP dynamics, Ca²⁺ signaling, and beta-cell synchronization in pancreatic islets. Full article

Dynamic insulin secretion and glucose homeostasis are dependent on the appropriate maturation and function of pancreatic β-cells. The islet-enriched musculoaponeurotic fibrosarcoma oncogene family A (MAFA) transcription factor acts as a master regulator of β-cell identity and function, coordinating gene expression networks required for glucose-stimulated insulin secretion. Dysregulation of MAFA contributes to β-cell dysfunction, as reduced expression is detected early in the pathogenesis of Type 1 Diabetes and Type 2 Diabetes, while long-lived variants can drive monogenic forms of diabetes. In this review, we summarize the current understanding of MAFA on β-cell maturation and function in both the mouse and human. This includes structural features of the MAFA protein, regulation of MAFA transcription, post-translational modifications, and emerging areas of research for therapeutic potential. Full article

Rotavirus infection is a major cause of acute gastroenteritis in children, which is characterized by fever, emesis, and diarrhea. In some children, rotaviral infection can spread beyond the gastrointestinal tract and affect the nervous system, kidneys, liver, or pancreas. There are relatively few longitudinal studies of such long-term sequalae. One area of interest has been damage to pancreatic beta islet cells, the lack of which causes type 1 diabetes mellitus. This chronic disease can be life threatening, especially in young children, and is associated with lifelong elevated risks of cardiovascular disease, neuropathy, nephropathy, and retinopathy. This narrative review summarizes the scientific evidence relevant to rotavirus infection and early-onset type 1 diabetes. The results of epidemiologic, animal, and laboratory research indicate that rotavirus infection increases the risk of type 1 diabetes in young children (<5 years of age). Rotavirus vaccination is associated with lower incidence rates; the data suggest a somewhat stronger effect with the pentavalent vaccine than the monovalent vaccine. Continued surveillance of both rotavirus infection and type 1 diabetes are necessary, considering the increases in vaccine hesitancy. The benefits of rotavirus vaccination should be discussed with parents and individuals planning to have children. Full article

Background/Objectives: Type 1 diabetes (T1D) is an autoimmune disease characterized by progressive β-cell loss. Apolipoprotein CIII (apoCIII), a lipid metabolism regulator, is elevated in T1D and implicated in β-cell apoptosis. Antisense oligonucleotide–mediated apoCIII reduction delays diabetes onset in diabetes-prone BioBreeding (DPBB) rats. This study examined whether small-interfering RNA (siRNA) targeting apoCIII during the final prediabetic month preserves islet integrity and delays T1D onset. Methods: Two siRNAs targeting rat apoCIII were evaluated in 30-day-old DPBB rats for efficacy and off-target effects. Hepatic and plasma apoCIII levels were measured, and neighboring apolipoprotein gene expression was assessed. The most specific candidate (apoCIII-siRNA2) was selected. Duration of action was determined after a single injection. To study the effects of apoCIII-lowering treatment in vivo, islets from 25-day-old DPBB rats were transplanted into the anterior chamber of the eye of age-matched DPBB recipients. Rats received weekly intravenous injections of apoCIII-siRNA2 from day 30 until diabetes onset. Islet morphology, vascularization, and phagocyte infiltration were assessed by confocal imaging three and five weeks post-transplantation. Results: Both siRNAs reduced apoCIII, but one showed off-target effects and was excluded. A single injection of apoCIII-siRNA2 suppressed plasma apoCIII for approximately one week and weekly treatment maintained low circulating apoCIII levels. Five weeks after transplantation islet morphology and vascularization were preserved, and there was no increase in phagocyte infiltration. This resulted in a delayed onset of diabetes. Conclusions: siRNA-mediated apoCIII reduction delays pancreatic islet deterioration and T1D onset in DPBB rats, supporting apoCIII as a contributing factor to β-cell vulnerability and thereby a potential therapeutic target. Full article

Variants in the human PAX4 gene are associated with both monogenic and complex forms of diabetes, yet their pathogenic effects remain difficult to define in models that accurately mimic human islet architecture and neonatal metabolic transitions. Here, we created a porcine PAX4 loss-of-function model using CRISPR/Cas9 cytidine deaminase base editing to introduce a premature stop codon in the PAX4 coding sequence. PAX4 knockout piglets developed severe hyperglycemia within 24 h of birth, followed by rapid postnatal clinical deterioration and uniform death by day 3. Biochemical analysis showed significant diabetic decompensation, including electrolyte imbalances, hyperosmolality, azotemia, dyslipidemia, and metabolic acidosis. Gross and histological examinations revealed notable pancreatic hypoplasia with preservation of exocrine tissue. Single-nucleus RNA sequencing and immunohistochemistry demonstrated an almost complete loss of insulin- and somatostatin-producing β- and δ-cells, respectively, with relative preservation of glucagon-expressing α-cells. Overall, these results establish PAX4 as a crucial factor in pancreatic endocrine development and postnatal glucose regulation in a large-animal model. This platform offers a human-relevant system for studying diabetes-associated PAX4 variants and for testing regenerative and gene-based therapies for insulin-deficient diabetes. Full article

Diabetes mellitus represents a major global health challenge with rapidly increasing prevalence and substantial morbidity driven by metabolic and vascular complications. Extracellular vesicles (EVs) have emerged as critical mediators of intercellular communication and are increasingly implicated in the pathogenesis and progression of diabetes. This review summarizes current knowledge on EV biology, including their classification, cellular sources, biogenesis, uptake mechanisms, and molecular cargo. We discuss the contribution of EV-associated microRNAs to immune dysregulation and β-cell damage in type 1 diabetes mellitus (T1DM), as well as the role of EVs in insulin resistance, metabolic signaling, and vascular dysfunction in type 2 diabetes mellitus (T2DM). Particular emphasis is placed on EV-mediated modulation of endothelial function, angiogenesis, and tissue repair, alongside their involvement in the impairment of insulin receptor integrity. We further explore how lifestyle factors may influence EV composition and function, highlighting their potential integration into preventive strategies. Finally, we evaluate the emerging therapeutic potential of EVs as biomarkers and delivery systems, while addressing current limitations and future directions. Collectively, EVs represent a promising frontier in understanding diabetes pathophysiology and developing innovative diagnostic and therapeutic approaches. Unlike previous reviews that examine EVs separately as biomarkers or therapeutic vehicles, this review integrates emerging evidence supporting EVs as mediators of systemic communication linking pancreatic islets, adipose tissue, immune cells, vascular endothelium, kidney, heart, and retina throughout diabetes progression. We further critically evaluate translational barriers that currently limit clinical implementation of EV-based diagnostics and therapeutics. Full article

Background: Pathological aggregation of islet amyloid polypeptide (IAPP) contributes to β-cell dysfunction in type 2 diabetes. Our previous studies demonstrated that caveolin-1 (Cav-1) deficiency protects β-cells from palmitate-induced apoptosis. Microarray profiling further indicated that Cav-1 silencing alters IAPP expression. This study aimed to investigate the effects of Cav-1 depletion on IAPP secretion and expression and to explore the potential involvement of thioredoxin-interacting protein (TXNIP). Methods: We performed lentiviral-mediated Cav-1 knockdown in NIT-1 cells and isolated murine islets, and simultaneously generated an inducible β-cell-specific Cav-1 knockout (iβ-Cav1 KO) mouse model. IAPP secretion and expression were assessed by ELISA, Western blot, qPCR and immunofluorescence. The expression of IAPP-processing enzymes (PAM, PC1, and PC2) and degradation factors (IDE and BACE2) was examined. Co-immunoprecipitation (Co-IP) and immunofluorescence were performed to investigate the interaction between Cav-1 and TXNIP. Results: Cav-1 depletion significantly reduced both IAPP secretion and expression in vitro and in vivo. High-fat-diet-fed iβ-Cav1 KO mice exhibited the lowest serum IAPP levels. Mechanistically, Cav-1 depletion was associated with downregulation of PAM, PC1, and PC2 and upregulation of IDE and BACE2. Additionally, Cav-1 depletion decreased TXNIP expression. Immunofluorescence revealed co-localization of Cav-1 and TXNIP, and co-immunoprecipitation further demonstrated their direct physical interaction. Conclusions: Cav-1 is essential for IAPP secretion and expression in β-cells. The direct physical interaction between Cav-1 and TXNIP suggests that TXNIP may mediate the regulatory effects of Cav-1 on IAPP processing or secretion. These findings identify the Cav-1–TXNIP axis as a potential target for mitigating IAPP-related β-cell dysfunction. Full article

Background: Type 2 diabetes is projected to affect millions of people annually as the number of cases rises year on year. This includes children. Treating diabetes and its related comorbidities has a huge economic impact and puts pressure on healthcare providers. Understanding the disease at a molecular level is key for developing better therapeutics. The protein Islet Amyloid Polypeptide (IAPP) or amylin is important for glucose regulation; however, it is also instrumental in type 2 diabetes pathology. Human IAPP can misfold into oligomers and amyloid fibrillar aggregates within pancreatic islets, promoting β-cell dysfunction and death, contributing to progressive insulin deficiency and worsening hyperglycaemia. Methods: Based on previous studies on mutations at residues 18, 28 and 31,we have designed three novel IAPP analogues (two double and one triple mutant) to assess whether the combined amino acid substitutions impact fibril formation, solubility and toxicity. Results: All three of our analogues show a reduced propensity to aggregate and are more soluble than wild type IAPP. Compared with pramlintide, a clinically prescribed synthetic analogue of human amylin, all of our analogues appeared to have similarly reduced toxicity and improved solubility relative to human IAPP. Additionally, two of our analogues exhibited a markedly slower rate of fibril formation. Conclusions: Our results highlight the importance of targeting multiple residues as a promising strategy for developing improved diabetes therapeutics in the future. Full article

The pancreas is an organ with two functions: endocrine and exocrine. The proper functioning of the pancreas depends on many factors. One of these is trace elements—precise control of trace element homeostasis is important for both the endocrine and exocrine parts. This review provides a comprehensive summary of current knowledge regarding the role of trace elements: iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), zinc (Zn), silver (Ag), cadmium (Cd), mercury (Hg), lead (Pb), and selenium (Se) in pancreatic physiology and their influence on the pathogenesis of key diseases of this organ, such as diabetes (DM), acute (AP) and chronic pancreatitis (CP), autoimmune pancreatitis (AIP), and pancreatic cancer (PC). Trace elements, including Fe, Cu, Zn, Se, and Mn, play a fundamental role in maintaining endocrine and exocrine homeostasis, participating in insulin synthesis, stabilizing digestive enzymes, and the functioning of antioxidant systems. It has been demonstrated that disturbances in their concentrations lead to the activation of pathological molecular pathways, including oxidative stress, chronic inflammation, and beta-cell apoptosis. In the context of diabetes, excess Fe promotes ferroptosis, whilst exposure to heavy metals such as Cd, Pb, and Hg induces insulin resistance and pancreatic islet dysfunction. In the course of pancreatitis, elements such as Zn and Se exhibit protective potential by stabilizing tissue barriers, whereas toxic metals impair ion transport, exacerbating fibrotic processes. Furthermore, analysis of available data indicates a significant association between heavy metal accumulation and pancreatic carcinogenesis, driven by DNA damage and oncogene modulation. Understanding pancreatic metallomics opens new prospects for early diagnosis, environmental prevention, and the development of targeted therapeutic strategies that restore the body’s micronutrient balance. Full article

Toxic metals from industrialization and urbanization pose major human health risks, and mixture-based exposure requires broader toxicity assessment. This study investigated the effects of a mixture of arsenic, lead, mercury, cadmium, chromium (VI), and nickel on pancreatic function in rats (45 male/45 female; n = 5 per group), focusing on sex- and duration-specific differences after 28 and 90 days of exposure. The metals were administered as a single mixture dissolved in deionised water via oral gavage. Evaluated parameters included pancreatic metal levels, histopathology, serum glucose, amylase, malate dehydrogenase 1 (MDH-1) activity, redox status, and bioelements. Dose levels were based on human exposure data to reflect realistic scenarios. Metals accumulated in pancreatic tissue, causing dose- and time-dependent histopathological changes, including acinar cell vacuolization, vascular congestion, and Langerhans islet alterations. Males showed more pronounced vascular and islet changes, while females had greater acinar alterations. In males, higher doses decreased glucose and amylase and increased MDH-1 activity, while females showed more variable responses. Males demonstrated adaptive responses to oxidative stress over time, while females experienced more persistent stress. These findings reveal sex-, dose-, and duration-dependent effects of toxic metal(oid) mixtures on pancreatic function, indicating that individually safe doses may be harmful when combined. Full article