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1.
Int J Nanomedicine ; 19: 4957-4976, 2024.
Article En | MEDLINE | ID: mdl-38828198

Background: The "gut-islets axis" is an important endocrine signaling axis that regulates islets function by modulating the gut microbiota and endocrine metabolism within the gut. However, the specific mechanisms and roles of the intestine in islets regulation remain unclear. Recent studies investigated that exosomes derived from gut microbiota can transport signals to remotely regulate islets ß-cell function, suggesting the possibility of novel signaling pathways mediated by gut exosomes in the regulation of the "gut-islet axis.". Methods: The exosomes were isolated from the intestinal enteroendocrine cell-line STC-1cells culture supernatants treated with palmitate acid (PA) or BSA. Metabolic stress models were established by separately subjecting MIN6 cells to PA stimulation and feeding mice with a high-fat diet. Intervention with exosomes in vitro and in vivo to assess the biological effects of exosomes on islets ß cells under metabolic stress. The Mas receptor antagonist A779 and ACE2ko mice were used to evaluate the role of exosomal ACE2. Results: We found ACE2, a molecule that plays a crucial role in the regulation of islets function, is abundantly expressed in exosomes derived from STC-1 under physiological normal condition (NCEO). These exosomes cannot only be taken up by ß-cells in vitro but also selectively transported to the islets in vivo. Following intervention with NCEXO, both Min6 cells in a lipotoxic environment and mice on a high-fat diet exhibited significant improvements in islets ß-cell function and ß-cell mass. Further investigations demonstrated that these protective effects are attributed to exosomal ACE2, as ACE2 inhibits NLRP3 inflammasome activation and reduces ß-cell pyroptosis. Conclusion: ACE2-enriched exosomes from the gut can selectively target islets, subsequently inhibiting NLRP3 inflammasome activation and ß cell pyroptosis, thereby restoring islets ß cell function under metabolic stress. This study provides novel insights into therapeutic strategies for the prevention and treatment of obesity and diabetes.


Angiotensin-Converting Enzyme 2 , Exosomes , Inflammasomes , Insulin-Secreting Cells , Mice, Inbred C57BL , NLR Family, Pyrin Domain-Containing 3 Protein , Pyroptosis , Animals , Exosomes/metabolism , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Mice , Pyroptosis/drug effects , Pyroptosis/physiology , Angiotensin-Converting Enzyme 2/metabolism , Inflammasomes/metabolism , Inflammasomes/drug effects , Cell Line , Intestine, Small/drug effects , Male , Diet, High-Fat , Mice, Knockout , Enteroendocrine Cells/drug effects , Enteroendocrine Cells/metabolism
2.
Cell Metab ; 36(6): 1169-1171, 2024 Jun 04.
Article En | MEDLINE | ID: mdl-38838638

In this issue of Cell Metabolism, Fang et al.1 report a novel pH-sensitive cellular signaling mechanism involving the transcription factor SMAD5 that regulates the vesicular secretion of insulin from pancreatic ß cells in response to dietary challenges. Dysregulation of this pathway may contribute to metabolic disorders such as type 2 diabetes mellitus.


Insulin Secretion , Insulin-Secreting Cells , Insulin , Signal Transduction , Smad5 Protein , Insulin/metabolism , Animals , Insulin-Secreting Cells/metabolism , Smad5 Protein/metabolism , Humans , Diabetes Mellitus, Type 2/metabolism , Mice , Hydrogen-Ion Concentration
3.
Mol Biol Rep ; 51(1): 711, 2024 Jun 01.
Article En | MEDLINE | ID: mdl-38824245

BACKGROUND: Diabetes is a chronic metabolic disease that affects many parts of the body. Considering diabetes as a beta cells' defect and loss, the focus is on finding mechanisms and compounds involved in stimulating the function and regeneration of pancreatic ß-cells. DNA methylation as an epigenetic mechanism plays a pivotal role in the ß-cells' function and development. Considering the regenerative and anti-diabetic effects of Rosa canina extract, this study aimed to assess the methylation levels of Pdx-1, Pax-4, and Ins-1 genes in diabetic rats treated with Rosa Canina extract. METHODS AND RESULTS: Streptozotocin-induced diabetic rats were used to evaluate the frequency of Pdx-1, Pax-4, and Ins-1 gene methylation. Treatment groups were exposed to Rosa canina as spray-dried and decoction extracts. Following blood glucose measurement, pancreatic DNA was extracted and bisulfited. Genes' methylation was measured using MSP-PCR and qRT-PCR techniques. Oral administration of Rosa canina extracts significantly reduced blood sugar levels in diabetic rats compared to the control group. The methylation levels of the Pdx-1, Pax-4, and Ins-1 genes promoter in streptozotocin-induced diabetic rats increased compared to the control rats while, the treatment of diabetic rats with Rosa canina extracts, spray-dried samples especially, led to a decreased methylation in these genes. CONCLUSION: The results of this study showed that Rosa canina extract as a spray-dried sample could be effective in treating diabetes by regulating the methylation of genes including Pdx-1, Pax-4, and Ins-1 involved in the activity and regeneration of pancreatic islet cells.


Blood Glucose , DNA Methylation , Diabetes Mellitus, Experimental , Plant Extracts , Rosa , Trans-Activators , Animals , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/drug therapy , Rosa/chemistry , DNA Methylation/drug effects , DNA Methylation/genetics , Rats , Plant Extracts/pharmacology , Male , Trans-Activators/genetics , Trans-Activators/metabolism , Blood Glucose/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Pancreas/drug effects , Pancreas/metabolism , Pancreas/pathology , Streptozocin , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Promoter Regions, Genetic/drug effects , Promoter Regions, Genetic/genetics , Paired Box Transcription Factors/genetics , Paired Box Transcription Factors/metabolism , Insulin/metabolism
4.
Sci Rep ; 14(1): 12639, 2024 06 02.
Article En | MEDLINE | ID: mdl-38825593

Chronic feeding of a high fat diet (HFD) in preclinical species induces broad metabolic dysfunction characterized by body weight gain, hyperinsulinemia, dyslipidemia and impaired insulin sensitivity. The plasma lipidome is not well characterized in dogs with HFD-induced metabolic dysfunction. We therefore aimed to describe the alterations that occur in the plasma lipid composition of dogs that are fed a HFD and examine the association of these changes with the clinical signs of metabolic dysfunction. Dogs were fed a normal diet (ND) or HFD for 12 weeks. Insulin sensitivity (SI) and beta cell compensation (AIRG) were assessed through an intravenous glucose tolerance test (IVGTT) and serum biochemistry was analyzed before the introduction of HFD and again after 12 weeks of continued ND or HFD feeding. Plasma lipidomics were conducted prior to the introduction of HFD and again at week 8 in both ND and HFD-fed dogs. 12 weeks of HFD feeding resulted in impaired insulin sensitivity and increased beta cell compensation measured by SI (ND mean: 11.5 [mU/l]-1 min-1, HFD mean: 4.7 [mU/l]-1 min-1) and AIRG (ND mean: 167.0 [mU/l]min, HFD mean: 260.2 [mU/l]min), respectively, compared to dogs fed ND over the same duration. Chronic HFD feeding increased concentrations of plasma lipid species and deleterious fatty acids compared to dogs fed a ND. Saturated fatty acid (SFA) concentrations were significantly associated with fasting insulin (R2 = 0.29), SI (R2 = 0.49) and AIRG (R2 = 0.37) in all dogs after 12 weeks, irrespective of diet. Our results demonstrate that chronic HFD feeding leads to significant changes in plasma lipid composition and fatty acid concentrations associated with metabolic dysfunction. High SFA concentrations may be predictive of deteriorated insulin sensitivity in dogs.


Diet, High-Fat , Fatty Acids , Insulin Resistance , Insulin-Secreting Cells , Animals , Dogs , Insulin-Secreting Cells/metabolism , Fatty Acids/metabolism , Fatty Acids/blood , Diet, High-Fat/adverse effects , Male , Glucose Tolerance Test , Insulin/blood , Insulin/metabolism , Female , Lipidomics/methods
5.
Islets ; 16(1): 2361996, 2024 Dec 31.
Article En | MEDLINE | ID: mdl-38833523

Epidemiological studies consistently link environmental toxicant exposure with increased Type 2 diabetes risk. Our study investigated the diabetogenic effects of a widely used flame retardant, Dechlorane Plus (DP), on pancreatic ß-cells using rodent and human model systems. We first examined pancreas tissues from male mice exposed daily to oral gavage of either vehicle (corn oil) or DP (10, 100, or 1000 µg/kg per day) and fed chow or high fat diet for 28-days in vivo. DP exposure did not affect islet size or endocrine cell composition in either diet group. Next, we assessed the effect of 48-hour exposure to vehicle (DMSO) or DP (1, 10, or 100 nM) in vitro using immortalized rat ß-cells (INS-1 832/3), primary mouse and human islets, and human stem-cell derived islet-like cells (SC-islets). In INS-1 832/3 cells, DP did not impact glucose-stimulated insulin secretion (GSIS) but significantly decreased intracellular insulin content. DP had no effect on GSIS in mouse islets or SC-islets but had variable effects on GSIS in human islets depending on the donor. DP alone did not affect insulin content in mouse islets, human islets, or SC-islets, but mouse islets co-exposed to DP and glucolipotoxic (GLT) stress conditions (28.7 mM glucose + 0.5 mM palmitate) had reduced insulin content compared to control conditions. Co-exposure of mouse islets to DP + GLT amplified the upregulation of Slc30a8 compared to GLT alone. Our study highlights the importance and challenges of using different in vitro models for studying chemical toxicity.


Hydrocarbons, Chlorinated , Insulin-Secreting Cells , Polycyclic Compounds , Animals , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Humans , Mice , Male , Polycyclic Compounds/pharmacology , Hydrocarbons, Chlorinated/toxicity , Rats , Insulin/metabolism , Flame Retardants/toxicity , Insulin Secretion/drug effects , Mice, Inbred C57BL , Cells, Cultured
6.
Cell Stem Cell ; 31(6): 793-794, 2024 Jun 06.
Article En | MEDLINE | ID: mdl-38848685

Getting mature and functional stem cell-derived, insulin-producing ß cells is an important step for disease modeling, drug screening, and cell replacement therapy. In this issue, Hua et al.1 used single-cell multiomics analysis coupled with chemical screening to identify a crucial role for ceramides in generating mature stem cell-derived ß cells.


Cell Differentiation , Insulin-Secreting Cells , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/metabolism , Humans , Animals , Stem Cells/cytology , Stem Cells/metabolism , Ceramides/metabolism , Single-Cell Analysis
7.
Nat Commun ; 15(1): 4410, 2024 May 23.
Article En | MEDLINE | ID: mdl-38782979

Pancreatic ß cells secrete insulin in response to glucose elevation to maintain glucose homeostasis. A complex network of inter-organ communication operates to modulate insulin secretion and regulate glucose levels after a meal. Lipids obtained from diet or generated intracellularly are known to amplify glucose-stimulated insulin secretion, however, the underlying mechanisms are not completely understood. Here, we show that a Drosophila secretory lipase, Vaha (CG8093), is synthesized in the midgut and moves to the brain where it concentrates in the insulin-producing cells in a process requiring Lipid Transfer Particle, a lipoprotein originating in the fat body. In response to dietary fat, Vaha stimulates insulin-like peptide release (ILP), and Vaha deficiency results in reduced circulatory ILP and diabetic features including hyperglycemia and hyperlipidemia. Our findings suggest Vaha functions as a diacylglycerol lipase physiologically, by being a molecular link between dietary fat and lipid amplified insulin secretion in a gut-brain axis.


Brain , Drosophila Proteins , Drosophila melanogaster , Insulin Secretion , Insulin , Animals , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Brain/metabolism , Insulin/metabolism , Insulin-Secreting Cells/metabolism , Brain-Gut Axis/physiology , Lipase/metabolism , Lipase/genetics , Dietary Fats/metabolism , Glucose/metabolism , Fat Body/metabolism , Lipoprotein Lipase/metabolism , Lipoprotein Lipase/genetics , Male
8.
Int J Biol Macromol ; 270(Pt 2): 132226, 2024 Jun.
Article En | MEDLINE | ID: mdl-38729469

A novel natural water-soluble acidic polysaccharide (PWESP-3) was isolated from squash with a molecular mass of 140.519 kDa, which was composed of arabinose (Ara, 35.30 mol%), galactose (Gal, 61.20 mol%), glucose (Glc, 1.80 mol%), and Mannuronic acid (ManA, 1.70 mol%) and contained Araf-(1→, →3)-Araf-(1→, →5)-Araf-(1→, Glcp-(1→, Galp-(1→, →3,5)-Araf-(1→, →2)-Glcp-(1→, →2)-Manp-(1→, →3)-Glcp-(1→, →4)-Galp-(1→, →3)-Galp-(1→, →6)-Galp-(1→, →3,4)-Galp-(1→, →4,6)-Galp-(1→ residues in the backbone. Moreover, the structure of PWESP-3 was identified by NMR spectra. The branch chain was connected to the main chain by the O-3 and O-4 atom of Gal. In addition, the effect of PWESP-3 on STZ-induced type I diabetes mellitus model in MIN6 cells was investigated. The results showed that PWESP-3 can increase the viability and insulin secretion of MIN6 cells and reduce the oxidative stress caused by ROS and NO. Meanwhile, PWESP-3 can also reduce the content of ATP, Ca2+, mitochondrial membrane potential and Caspase-3 activity in MIN6 cells. Furthermore, treatment with PWESP-3 can prevent single or double stranded DNA breaking to form DNA fragments and improve DNA damage in MIN6 cells, thereby avoiding apoptosis. Therefore, the above data highlight that PWESP-3 can improve the function of insulin secretion in STZ-induced MIN6 cells in vitro and can be used as an alternative food supplement to diabetes drugs.


Diabetes Mellitus, Experimental , Polysaccharides , Animals , Polysaccharides/pharmacology , Polysaccharides/chemistry , Mice , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Insulin/metabolism , Cell Line , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Reactive Oxygen Species/metabolism , Apoptosis/drug effects , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Streptozocin
9.
Front Endocrinol (Lausanne) ; 15: 1388361, 2024.
Article En | MEDLINE | ID: mdl-38745946

Introduction: The pathogenesis of Post-Transplant Diabetes Mellitus (PTDM) is complex and multifactorial and it resembles that of Type-2 Diabetes Mellitus (T2DM). One risk factor specific to PTDM differentiates both entities: the use of immunosuppressive therapy. Specifically, Tacrolimus interacts with obesity and insulin resistance (IR) in accelerating the onset of PTDM. In a genotypic model of IR, the obese Zucker rats, Tacrolimus is highly diabetogenic by promoting the same changes in beta-cell already modified by IR. Nevertheless, genotypic animal models have their limitations and may not resemble the real pathophysiology of diabetes. In this study, we have evaluated the interaction between beta-cell damage and Tacrolimus in a non-genotypic animal model of obesity and metabolic syndrome. Methods: Sprague Dawley rats were fed a high-fat enriched diet during 45 days to induce obesity and metabolic dysregulation. On top of this established obesity, the administration of Tacrolimus (1mg/kg/day) during 15 days induced severe hyperglycaemia and changes in morphological and structural characteristics of the pancreas. Results: Obese animals administered with Tacrolimus showed increased size of islets of Langerhans and reduced beta-cell proliferation without changes in apoptosis. There were also changes in beta-cell nuclear factors such as a decrease in nuclear expression of MafA and a nuclear overexpression of FoxO1A, PDX-1 and NeuroD1. These animals also showed increased levels of pancreatic insulin and glucagon. Discussion: This model could be evidence of the relationship between the T2DM and PTDM physiopathology and, eventually, the model may be instrumental to study the pathogenesis of T2DM.


Disease Models, Animal , Metabolic Syndrome , Obesity , Rats, Sprague-Dawley , Tacrolimus , Animals , Tacrolimus/pharmacology , Metabolic Syndrome/metabolism , Metabolic Syndrome/pathology , Metabolic Syndrome/chemically induced , Obesity/metabolism , Obesity/pathology , Rats , Male , Immunosuppressive Agents/adverse effects , Immunosuppressive Agents/pharmacology , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Insulin-Secreting Cells/drug effects , Phenotype , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Experimental/metabolism , Insulin Resistance , Diet, High-Fat/adverse effects
10.
Cell Stem Cell ; 31(6): 850-865.e10, 2024 Jun 06.
Article En | MEDLINE | ID: mdl-38697109

Human pluripotent stem cell-derived ß cells (hPSC-ß cells) show the potential to restore euglycemia. However, the immature functionality of hPSC-ß cells has limited their efficacy in application. Here, by deciphering the continuous maturation process of hPSC-ß cells post transplantation via single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq), we show that functional maturation of hPSC-ß cells is an orderly multistep process during which cells sequentially undergo metabolic adaption, removal of negative regulators of cell function, and establishment of a more specialized transcriptome and epigenome. Importantly, remodeling lipid metabolism, especially downregulating the metabolic activity of ceramides, the central hub of sphingolipid metabolism, is critical for ß cell maturation. Limiting intracellular accumulation of ceramides in hPSC-ß cells remarkably enhanced their function, as indicated by improvements in insulin processing and glucose-stimulated insulin secretion. In summary, our findings provide insights into the maturation of human pancreatic ß cells and highlight the importance of ceramide homeostasis in function acquisition.


Cell Differentiation , Ceramides , Homeostasis , Insulin-Secreting Cells , Pluripotent Stem Cells , Humans , Ceramides/metabolism , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/cytology , Pluripotent Stem Cells/metabolism , Pluripotent Stem Cells/cytology , Animals
11.
J Diabetes Complications ; 38(6): 108764, 2024 Jun.
Article En | MEDLINE | ID: mdl-38701667

OBJECTIVE: Dysglycemia is a significant risk factor for cognitive impairment. However, which pathophysiologic determinant(s) of dysglycemia, impaired insulin sensitivity (ISens) or the islet ß-cell's response (IResp), contribute to poorer cognitive function, independent of dysglycemia is not established. Among 1052 adults with pre-diabetes from the Diabetes Prevention Program Outcomes Study (DPPOS), we investigated the relationship between IResp, ISens and cognitive function. RESEARCH DESIGN AND METHODS: IResp was estimated by the insulinogenic index (IGI; pmol/mmol) and ISens as 1/fasting insulin from repeated annual oral glucose tolerance tests. The mean IResp and mean ISens were calculated over approximately 12 years of follow-up. Verbal learning (Spanish-English Verbal Learning Test [SEVLT]) and executive function (Digital Symbol Substitution Test [DSST]) were assessed at the end of the follow-up period. Linear regression models were run for each cognitive outcome and were adjusted for dysglycemia and other factors. RESULTS: Higher IResp was associated with poorer performance on the DSST (-0.69 points per 100 unit increase in IGI, 95 % CI: -1.37, -0.01). ISens was not associated with DSST, nor were IResp or ISens associated with performance on the SEVLT. CONCLUSIONS: These results suggest that a greater ß-cell response in people at high risk for type 2 diabetes is associated with poorer executive function, independent of dysglycemia and ISens.


Diabetes Mellitus, Type 2 , Insulin Resistance , Insulin , Prediabetic State , Humans , Prediabetic State/psychology , Prediabetic State/complications , Prediabetic State/blood , Prediabetic State/epidemiology , Male , Female , Middle Aged , Adult , Insulin/blood , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/psychology , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/prevention & control , Cognition/physiology , Glucose Tolerance Test , Insulin-Secreting Cells/physiology , Insulin-Secreting Cells/metabolism , Follow-Up Studies , Cognition Disorders/prevention & control , Cognition Disorders/etiology , Cognition Disorders/epidemiology , Cognition Disorders/blood , Aged , Executive Function/physiology
12.
Life Sci ; 348: 122717, 2024 Jul 01.
Article En | MEDLINE | ID: mdl-38744419

The loss or dysfunction of pancreatic ß-cells, which are responsible for insulin secretion, constitutes the foundation of all forms of diabetes, a widely prevalent disease worldwide. The replacement of damaged ß-cells with regenerated or transplanted cells derived from stem cells is a promising therapeutic strategy. However, inducing the differentiation of stem cells into fully functional glucose-responsive ß-cells in vitro has proven to be challenging. Noncoding RNAs (ncRNAs) have emerged as critical regulatory factors governing the differentiation, identity, and function of ß-cells. Furthermore, engineered hydrogel systems, biomaterials, and organ-like structures possess engineering characteristics that can provide a three-dimensional (3D) microenvironment that supports stem cell differentiation. This review summarizes the roles and contributions of ncRNAs in maintaining the differentiation, identity, and function of ß-cells. And it focuses on regulating the levels of ncRNAs in stem cells to activate ß-cell genetic programs for generating alternative ß-cells and discusses how to manipulate ncRNA expression by combining hydrogel systems and other tissue engineering materials. Elucidating the patterns of ncRNA-mediated regulation in ß-cell biology and utilizing this knowledge to control stem cell differentiation may offer promising therapeutic strategies for generating functional insulin-producing cells in diabetes cell replacement therapy and tissue engineering.


Cell Differentiation , Insulin-Secreting Cells , RNA, Untranslated , Tissue Engineering , Insulin-Secreting Cells/metabolism , Tissue Engineering/methods , Humans , RNA, Untranslated/genetics , Animals , Cell Differentiation/genetics , Stem Cells/metabolism , Stem Cells/cytology , Diabetes Mellitus/metabolism , Diabetes Mellitus/genetics , Diabetes Mellitus/therapy , Hydrogels
13.
Pediatr Diabetes ; 20242024.
Article En | MEDLINE | ID: mdl-38765897

Background: A-ß+ ketosis-prone diabetes (KPD) in adults is characterized by presentation with diabetic ketoacidosis (DKA), negative islet autoantibodies, and preserved ß-cell function in persons with a phenotype of obesity-associated type 2 diabetes (T2D). The prevalence of KPD has not been evaluated in children. We investigated children with DKA at "T2D" onset and determined the prevalence and characteristics of pediatric A-ß+ KPD within this cohort. Methods: We reviewed the records of 716 children with T2D at a large academic hospital and compared clinical characteristics of those with and without DKA at onset. In the latter group, we identified patients with A-ß+ KPD using criteria of the Rare and Atypical Diabetes Network (RADIANT) and defined its prevalence and characteristics. Results: Mean age at diagnosis was 13.7 ± 2.4 years: 63% female; 59% Hispanic, 29% African American, 9% non-Hispanic White, and 3% other. Fifty-six (7.8%) presented with DKA at diagnosis and lacked islet autoantibodies. Children presenting with DKA were older and had lower C-peptide and higher glucose concentrations than those without DKA. Twenty-five children with DKA (45%) met RADIANT A-ß+ KPD criteria. They were predominantly male (64%), African American or Hispanic (96%), with substantial C-peptide (1.3 ± 0.7 ng/mL) at presentation with DKA and excellent long-term glycemic control (HbA1c 6.6% ± 1.9% at follow-up (median 1.3 years postdiagnosis)). Conclusions: In children with a clinical phenotype of T2D and DKA at diagnosis, approximately half meet criteria for A-ß+ KPD. They manifest the key characteristics of obesity, preserved ß-cell function, male predominance, and potential to discontinue insulin therapy, similar to adults with A-ß+ KPD.


Diabetes Mellitus, Type 2 , Diabetic Ketoacidosis , Humans , Female , Male , Diabetic Ketoacidosis/epidemiology , Diabetic Ketoacidosis/diagnosis , Diabetic Ketoacidosis/etiology , Child , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Adolescent , Prevalence , Insulin-Secreting Cells/immunology , Insulin-Secreting Cells/physiology , Insulin-Secreting Cells/metabolism , Retrospective Studies
14.
J Diabetes ; 16(6): e13557, 2024 Jun.
Article En | MEDLINE | ID: mdl-38751366

Diabetes mellitus (DM) is a common chronic disease affecting humans globally. It is characterized by abnormally elevated blood glucose levels due to the failure of insulin production or reduction of insulin sensitivity and functionality. Insulin and glucagon-like peptide (GLP)-1 replenishment or improvement of insulin resistance are the two major strategies to treat diabetes. Recently, optogenetics that uses genetically encoded light-sensitive proteins to precisely control cell functions has been regarded as a novel therapeutic strategy for diabetes. Here, we summarize the latest development of optogenetics and its integration with synthetic biology approaches to produce light-responsive cells for insulin/GLP-1 production, amelioration of insulin resistance and neuromodulation of insulin secretion. In addition, we introduce the development of cell encapsulation and delivery methods and smart bioelectronic devices for the in vivo application of optogenetics-based cell therapy in diabetes. The remaining challenges for optogenetics-based cell therapy in the clinical translational study are also discussed.


Diabetes Mellitus , Optogenetics , Humans , Optogenetics/methods , Diabetes Mellitus/therapy , Animals , Insulin/metabolism , Insulin Resistance , Glucagon-Like Peptide 1 , Cell- and Tissue-Based Therapy/methods , Insulin-Secreting Cells/metabolism
15.
Cells ; 13(10)2024 May 18.
Article En | MEDLINE | ID: mdl-38786091

The dysfunction of α and ß cells in pancreatic islets can lead to diabetes. Many questions remain on the subcellular organization of islet cells during the progression of disease. Existing three-dimensional cellular mapping approaches face challenges such as time-intensive sample sectioning and subjective cellular identification. To address these challenges, we have developed a subcellular feature-based classification approach, which allows us to identify α and ß cells and quantify their subcellular structural characteristics using soft X-ray tomography (SXT). We observed significant differences in whole-cell morphological and organelle statistics between the two cell types. Additionally, we characterize subtle biophysical differences between individual insulin and glucagon vesicles by analyzing vesicle size and molecular density distributions, which were not previously possible using other methods. These sub-vesicular parameters enable us to predict cell types systematically using supervised machine learning. We also visualize distinct vesicle and cell subtypes using Uniform Manifold Approximation and Projection (UMAP) embeddings, which provides us with an innovative approach to explore structural heterogeneity in islet cells. This methodology presents an innovative approach for tracking biologically meaningful heterogeneity in cells that can be applied to any cellular system.


Glucagon-Secreting Cells , Insulin-Secreting Cells , Insulin-Secreting Cells/metabolism , Glucagon-Secreting Cells/metabolism , Animals , Tomography, X-Ray/methods , Mice , Humans , Insulin/metabolism
16.
PLoS Comput Biol ; 20(5): e1012130, 2024 May.
Article En | MEDLINE | ID: mdl-38739680

Within the islets of Langerhans, beta cells orchestrate synchronized insulin secretion, a pivotal aspect of metabolic homeostasis. Despite the inherent heterogeneity and multimodal activity of individual cells, intercellular coupling acts as a homogenizing force, enabling coordinated responses through the propagation of intercellular waves. Disruptions in this coordination are implicated in irregular insulin secretion, a hallmark of diabetes. Recently, innovative approaches, such as integrating multicellular calcium imaging with network analysis, have emerged for a quantitative assessment of the cellular activity in islets. However, different groups use distinct experimental preparations, microscopic techniques, apply different methods to process the measured signals and use various methods to derive functional connectivity patterns. This makes comparisons between findings and their integration into a bigger picture difficult and has led to disputes in functional connectivity interpretations. To address these issues, we present here a systematic analysis of how different approaches influence the network representation of islet activity. Our findings show that the choice of methods used to construct networks is not crucial, although care is needed when combining data from different islets. Conversely, the conclusions drawn from network analysis can be heavily affected by the pre-processing of the time series, the type of the oscillatory component in the signals, and by the experimental preparation. Our tutorial-like investigation aims to resolve interpretational issues, reconcile conflicting views, advance functional implications, and encourage researchers to adopt connectivity analysis. As we conclude, we outline challenges for future research, emphasizing the broader applicability of our conclusions to other tissues exhibiting complex multicellular dynamics.


Islets of Langerhans , Islets of Langerhans/physiology , Islets of Langerhans/metabolism , Islets of Langerhans/cytology , Animals , Computational Biology/methods , Mice , Insulin/metabolism , Humans , Insulin-Secreting Cells/physiology , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/cytology , Insulin Secretion/physiology , Models, Biological , Calcium/metabolism , Calcium Signaling/physiology
17.
Sci Rep ; 14(1): 12521, 2024 05 31.
Article En | MEDLINE | ID: mdl-38822085

Sirtuin1 (SIRT1) activity decreases the tuberous sclerosis complex 2 (TSC2) lysine acetylation status, inhibiting the mechanistic target of rapamycin complex 1 (mTORC1) signalling and concomitantly, activating autophagy. This study analyzes the role of TSC2 acetylation levels in its translocation to the lysosome and the mitochondrial turnover in both mouse embryonic fibroblast (MEF) and in mouse insulinoma cells (MIN6) as a model of pancreatic ß cells. Resveratrol (RESV), an activator of SIRT1 activity, promotes TSC2 deacetylation and its translocation to the lysosome, inhibiting mTORC1 activity. An improvement in mitochondrial turnover was also observed in cells treated with RESV, associated with an increase in the fissioned mitochondria, positive autophagic and mitophagic fluxes and an enhancement of mitochondrial biogenesis. This study proves that TSC2 in its deacetylated form is essential for regulating mTORC1 signalling and the maintenance of the mitochondrial quality control, which is involved in the homeostasis of pancreatic beta cells and prevents from several metabolic disorders such as Type 2 Diabetes Mellitus.


Lysosomes , Mechanistic Target of Rapamycin Complex 1 , Mitochondria , Sirtuin 1 , Tuberous Sclerosis Complex 2 Protein , Tuberous Sclerosis Complex 2 Protein/metabolism , Tuberous Sclerosis Complex 2 Protein/genetics , Animals , Acetylation , Lysosomes/metabolism , Mice , Mitochondria/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Sirtuin 1/metabolism , Autophagy , Protein Transport , Resveratrol/pharmacology , Signal Transduction , Fibroblasts/metabolism , Insulin-Secreting Cells/metabolism , Cell Line, Tumor
18.
Cell Death Dis ; 15(5): 374, 2024 May 29.
Article En | MEDLINE | ID: mdl-38811543

High workload-induced cellular stress can cause pancreatic islet ß cell death and dysfunction, or ß cell failure, a hallmark of type 2 diabetes mellitus. Thus, activation of molecular chaperones and other stress-response genes prevents ß cell failure. To this end, we have shown that deletion of the glucose-regulated protein 94 (GRP94) in Pdx1+ pancreatic progenitor cells led to pancreas hypoplasia and reduced ß cell mass during pancreas development in mice. Here, we show that GRP94 was involved in ß cell adaption and compensation (or failure) in islets from leptin receptor-deficient (db/db) mice in an age-dependent manner. GRP94-deficient cells were more susceptible to cell death induced by various diabetogenic stress conditions. We also identified a new client of GRP94, insulin-like growth factor-1 receptor (IGF-1R), a critical factor for ß cell survival and function that may mediate the effect of GRP94 in the pathogenesis of diabetes. This study has identified essential functions of GRP94 in ß cell failure related to diabetes.


Insulin-Secreting Cells , Receptor, IGF Type 1 , Animals , Mice , Cell Death , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Diabetes Mellitus, Type 2/genetics , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Membrane Glycoproteins/metabolism , Membrane Glycoproteins/genetics , Mice, Inbred C57BL , Mice, Knockout , Receptor, IGF Type 1/metabolism , Receptor, IGF Type 1/genetics , Receptors, Leptin/metabolism , Receptors, Leptin/genetics
19.
Nat Commun ; 15(1): 4527, 2024 May 29.
Article En | MEDLINE | ID: mdl-38811550

The IL-22RA1 receptor is highly expressed in the pancreas, and exogenous IL-22 has been shown to reduce endoplasmic reticulum and oxidative stress in human pancreatic islets and promote secretion of high-quality insulin from beta-cells. However, the endogenous role of IL-22RA1 signaling on these cells remains unclear. Here, we show that antibody neutralisation of IL-22RA1 in cultured human islets leads to impaired insulin quality and increased cellular stress. Through the generation of mice lacking IL-22ra1 specifically on pancreatic alpha- or beta-cells, we demonstrate that ablation of murine beta-cell IL-22ra1 leads to similar decreases in insulin secretion, quality and islet regeneration, whilst increasing islet cellular stress, inflammation and MHC II expression. These changes in insulin secretion led to impaired glucose tolerance, a finding more pronounced in female animals compared to males. Our findings attribute a regulatory role for endogenous pancreatic beta-cell IL-22ra1 in insulin secretion, islet regeneration, inflammation/cellular stress and appropriate systemic metabolic regulation.


Glucose , Homeostasis , Insulin-Secreting Cells , Insulin , Mice, Knockout , Receptors, Interleukin , Animals , Insulin-Secreting Cells/metabolism , Receptors, Interleukin/metabolism , Receptors, Interleukin/genetics , Female , Humans , Male , Insulin/metabolism , Mice , Glucose/metabolism , Insulin Secretion , Mice, Inbred C57BL , Interleukin-22 , Glucose Intolerance/metabolism , Interleukins/metabolism , Interleukins/genetics , Aging/metabolism
20.
Nat Immunol ; 25(6): 981-993, 2024 Jun.
Article En | MEDLINE | ID: mdl-38811816

Viral infection makes us feel sick as the immune system alters systemic metabolism to better fight the pathogen. The extent of these changes is relative to the severity of disease. Whether blood glucose is subject to infection-induced modulation is mostly unknown. Here we show that strong, nonlethal infection restricts systemic glucose availability, which promotes the antiviral type I interferon (IFN-I) response. Following viral infection, we find that IFNγ produced by γδ T cells stimulates pancreatic ß cells to increase glucose-induced insulin release. Subsequently, hyperinsulinemia lessens hepatic glucose output. Glucose restriction enhances IFN-I production by curtailing lactate-mediated inhibition of IRF3 and NF-κB signaling. Induced hyperglycemia constrained IFN-I production and increased mortality upon infection. Our findings identify glucose restriction as a physiological mechanism to bring the body into a heightened state of responsiveness to viral pathogens. This immune-endocrine circuit is disrupted in hyperglycemia, possibly explaining why patients with diabetes are more susceptible to viral infection.


Blood Glucose , Immunity, Innate , Interferon-gamma , Animals , Interferon-gamma/metabolism , Interferon-gamma/immunology , Mice , Blood Glucose/metabolism , Insulin-Secreting Cells/immunology , Insulin-Secreting Cells/metabolism , Mice, Inbred C57BL , Signal Transduction/immunology , Insulin/metabolism , Insulin/immunology , Mice, Knockout , Hyperglycemia/immunology , Interferon Regulatory Factor-3/metabolism , NF-kappa B/metabolism , Humans , Liver/immunology , Liver/virology , Liver/metabolism , Male
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