47,407 results match your criteria islets pancreatic


Islet-on-a-chip: Biomimetic micropillar-based microfluidic system for three-dimensional pancreatic islet cell culture.

Biosens Bioelectron 2021 Apr 2;183:113215. Epub 2021 Apr 2.

Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Poland. Electronic address:

Type 2 diabetes is currently one of the most common metabolic diseases, affecting all ages worldwide. As the incidence of type 2 diabetes increases, a growing number of studies focus on islets of Langerhans. A three-dimensional research model that maps islet morphology and maintains hormonal balance in vivo is still needed. Read More

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The Human Islet: Mini-organ with Mega-impact.

Endocr Rev 2021 Apr 12. Epub 2021 Apr 12.

Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee.

This review focuses on the human pancreatic islet - including its structure, cell composition, development, function, and dysfunction. After providing a historical timeline of key discoveries about human islets over the past century, we describe new research approaches and technologies that are being used to study human islets and how these are providing insight into human islet physiology and pathophysiology. We also describe changes or adaptations in human islets in response to physiologic challenges such as pregnancy, aging, and insulin resistance and discuss islet changes in human diabetes of many forms. Read More

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Effects of long-acting analogues of lamprey GLP-1 and paddlefish glucagon on alpha- to beta-cell transdifferentiation in an insulin-deficient transgenic mouse model.

J Pept Sci 2021 Apr 11:e3328. Epub 2021 Apr 11.

Diabetes Research Group, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, UK.

The abilities of the long-acting, dual-agonist anti-diabetic peptides [D-Ala ]palmitoyl-lamprey GLP-1 and [D-Ser ]palmitoyl-paddlefish glucagon to induce α-cell to β-cell transdifferentiation were investigated in Glu ;ROSA26-eYFP mice. These animals have been genetically engineered so that yellow fluorescent protein is specifically expressed in glucagon-producing α-cells, thereby allowing cell lineage tracing. Insulin deficiency was produced by treatment of the mice with multiple low doses of streptozotocin. Read More

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Autologous transplantation of multilayered fibroblast sheets prevents postoperative pancreatic fistula by regulating fibrosis and angiogenesis.

Am J Transl Res 2021 15;13(3):1257-1268. Epub 2021 Mar 15.

Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine Yamaguchi, Japan.

Introduction: Postoperative pancreatic fistula (POPF) is a serious complication after gastrointestinal or pancreatic surgery. Despite intensive investigations, the occurrence has not significantly decreased in the past decades. The aims of this study were to clarify the pathophysiology of POPF and establish the preventive measures using multilayered fibroblast sheets. Read More

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Proinsulin-Reactive CD4 T Cells in the Islets of Type 1 Diabetes Organ Donors.

Front Endocrinol (Lausanne) 2021 25;12:622647. Epub 2021 Mar 25.

Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO, United States.

Proinsulin is an abundant protein that is selectively expressed by pancreatic beta cells and has been a focus for development of antigen-specific immunotherapies for type 1 diabetes (T1D). In this study, we sought to comprehensively evaluate reactivity to preproinsulin by CD4 T cells originally isolated from pancreatic islets of organ donors having T1D. We analyzed 187 T cell receptor (TCR) clonotypes expressed by CD4 T cells obtained from six T1D donors and determined their response to 99 truncated preproinsulin peptide pools, in the presence of autologous B cells. Read More

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Assessing Different Temporal Scales of Calcium Dynamics in Networks of Beta Cell Populations.

Front Physiol 2021 23;12:612233. Epub 2021 Mar 23.

Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.

Beta cells within the pancreatic islets of Langerhans respond to stimulation with coherent oscillations of membrane potential and intracellular calcium concentration that presumably drive the pulsatile exocytosis of insulin. Their rhythmic activity is multimodal, resulting from networked feedback interactions of various oscillatory subsystems, such as the glycolytic, mitochondrial, and electrical/calcium components. How these oscillatory modules interact and affect the collective cellular activity, which is a prerequisite for proper hormone release, is incompletely understood. Read More

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Physiology of pancreatic β-cells: Ion channels and molecular mechanisms implicated in stimulus-secretion coupling.

Int Rev Cell Mol Biol 2021 8;359:287-323. Epub 2021 Mar 8.

Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain. Electronic address:

The human and mouse islet of Langerhans is an endocrine organ composed of five different cells types; insulin-secreting β-cells, glucagon-producing α-cells, somatostatin-producing δ-cells, pancreatic polypeptide-secreting PP cells and ɛ-cells that secretes ghrelin. The most important cells are the pancreatic β-cells that comprise around 45-50% of human islets and 75-80% in the mouse. Pancreatic β-cells secrete insulin at high glucose concentration, thereby finely regulating glycaemia by the hypoglycaemic effects of this hormone. Read More

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Role of microRNA in pancreatic beta cell function.

Authors:
Flora Brozzi

Int Rev Cell Mol Biol 2021 23;359:257-286. Epub 2021 Mar 23.

Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland. Electronic address:

MicroRNA (miRNAs) are small non-coding RNA involved in gene expression regulation. Emerging evidences identify miRNAs as key regulators of beta cell physiology. Their role in fine-tuned gene expression regulation is crucial in the differentiation of insulin-producing cells and contributes to the acquisition and management of their unique phenotype. Read More

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Pancreatic islet transplantation under the kidney capsule of mice: model of refinement for molecular and graft analysis.

Lab Anim 2021 Apr 8:236772211004051. Epub 2021 Apr 8.

Translational Research for Diabetes, Inserm, University of Lille, France.

Diabetes cell therapy by human islet transplantation can restore an endogenous insulin secretion and normal glycaemic control in type 1 diabetic patients for as long as 10 years post transplantation. Before transplantation, each clinical islet preparation undergoes extensive and quality controls. The quality control assay consists of transplanting human islets under the kidney capsule of immunocompromised mice. Read More

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vascularization and islet function in a microwell device for pancreatic islet transplantation.

Biomed Mater 2021 Apr 8. Epub 2021 Apr 8.

Faculty of Science and Technology (TNW), University of Twente, Biomaterials Science and Technology, P O Box 217, 7500 AE Enschede, THE NETHERLANDS, Enschede, 7500AE, NETHERLANDS.

Islet encapsulation in membrane-based devices could allow for transplantation of donor islet tissue in the absence of immunosuppression. To achieve long-term survival of islets, the device should allow rapid exchange of essential nutrients and be vascularized to guarantee continued support of islet function. Recently, we have proposed a membrane-based macroencapsulation device consisting of a microwell membrane for islet separation covered by a micropatterned membrane lid. Read More

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Flipping the switch on the hub cell: Islet desynchronization through cell silencing.

PLoS One 2021 8;16(4):e0248974. Epub 2021 Apr 8.

Department of Mathematics & Statistics, University of Maryland Baltimore County, Baltimore, Maryland, United States of America.

Pancreatic β cells, responsible for secreting insulin into the bloodstream and maintaining glucose homeostasis, are organized in the islets of Langerhans as clusters of electrically coupled cells. Gap junctions, connecting neighboring cells, coordinate the behavior of the islet, leading to the synchronized oscillations in the intracellular calcium and insulin secretion in healthy islets. Recent experimental work has shown that silencing special hub cells can lead to a disruption in the coordinated behavior, calling into question the democratic paradigm of islet insulin secretion with more or less equal input from each β cell. Read More

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In vitro expansion of pancreatic islet clusters facilitated by hormones and chemicals.

Cell Discov 2020 Apr 7;6(1):20. Epub 2020 Apr 7.

Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Shandong University, 250012, Jinan, Shandong, China.

Tissue regeneration, such as pancreatic islet tissue propagation in vitro, could serve as a promising strategy for diabetes therapy and personalised drug testing. However, such a strategy has not been realised yet. Propagation could be divided into two steps, in vitro expansion and repeated passaging. Read More

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Blood leukocytes recapitulate diabetogenic peptide-MHC-II complexes displayed in the pancreatic islets.

J Exp Med 2021 Jun;218(6)

Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO.

Assessing the self-peptides presented by susceptible major histocompatibility complex (MHC) molecules is crucial for evaluating the pathogenesis and therapeutics of tissue-specific autoimmune diseases. However, direct examination of such MHC-bound peptides displayed in the target organ remains largely impractical. Here, we demonstrate that the blood leukocytes from the nonobese diabetic (NOD) mice presented peptide epitopes to autoreactive CD4 T cells. Read More

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Insulin-positive ductal cells do not migrate into preexisting islets during pregnancy.

Exp Mol Med 2021 Apr 5. Epub 2021 Apr 5.

Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224, USA.

The adult pancreatic ductal system was suggested to harbor facultative beta-cell progenitors similar to the embryonic pancreas, and the appearance of insulin-positive duct cells has been used as evidence for natural duct-to-beta-cell reprogramming. Nevertheless, the phenotype and fate of these insulin-positive cells in ducts have not been determined. Here, we used a cell-tagging dye, CFDA-SE, to permanently label pancreatic duct cells through an intraductal infusion technique. Read More

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The pancreatic islet: a micro-organ in control.

CellR4 Repair Replace Regen Reprogram 2021 19;9. Epub 2021 Mar 19.

Department of Surgery, Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.

The islets of Langerhans constitute the endocrine pancreas which regulates blood glucose homeostasis and their dysfunction results in diabetes. Each of the pancreatic islets constitutes an entire micro-organ with intricate cell to cell interactions and that is well vascularized and innervated. An important therapeutic advantage in islet transplant is that pancreatic islets maintain their organ integrity when isolated and transplanted to patients with severe diabetes. Read More

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The Vbeta13 T Cell Receptor Monoclonal Antibody Reduces Hyaluronan and CD68+, CD3+, and CD8+ Cell Infiltrations to Delay Diabetes in Congenic BB DR Rats.

Front Endocrinol (Lausanne) 2021 16;12:629242. Epub 2021 Mar 16.

Department of Clinical Sciences, Lund University Clinical Research Center (CRC), Skåne University Hospital, Malmö, Sweden.

The depleting Vβ13a T cell receptor monoclonal antibody (mAb) 17D5 prevents both induced and spontaneous autoimmune diabetes in BB rats. Here it was tested in congenic DR rats, all of which spontaneously developed diabetes. Starting at 40 days of age, rats were injected once weekly with either saline, His42 Vβ16 mAb, or 17D5 mAb and monitored for hyperglycemia. Read More

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AGE-RELATED MORPHO-FUNCTIONAL CHANGES IN RATS' PANCREAS UNDER HIGH-FAT DIET-INDUCED INSULIN RESISTANCE AND ITS PHARMACOLOGICAL TREATMENT.

Wiad Lek 2021 ;74(2):241-246

PALLADIN INSTITUTE OF BIOCHEMISTRY NAS OF UKRAINE, KYIV, UKRAINE.

Objective: The aim: To determine the set of structural and functional changes in pancreatic islets (PI) of obesity-induced insulin resistant (IR) rats of different age (young and old) fed with prolonged (6 month) high-fat diet (HFD) (58% of fat) and further treatment with N-Stearoylethanolamine (NSE), a bioactive N-Acylethanolamine.

Patients And Methods: Materials and methods: Alimentary obesity-induced IR model in rats of two age groups was used to investigate the influence of age and NSE treatment on pancreas morphology (using histological, histochemical and immunohistochemical techniques) and on several biochemical parameters associated with DM onset.

Results: Results: The NSE administration normalized pancreas morphology which was more affected in the old IR group; the signs of inflammation, edema, fibrosis and steatosis were somehow diminished and PI area became significantly increased. Read More

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Adaptive and maladaptive roles for ChREBP in the liver and pancreatic islets.

J Biol Chem 2021 Apr 1:100623. Epub 2021 Apr 1.

Division of Endocrinology and Metabolism, Duke University Medical Center, Durham, North Carolina, USA; Duke Molecular Physiology Institute, Duke University Medical Center, Durham, North Carolina, USA. Electronic address:

Excessive sugar consumption is a contributor to the worldwide epidemic of cardiometabolic disease. Understanding mechanisms by which sugar is sensed and regulates metabolic processes may provide new opportunities to prevent and treat these epidemics. Carbohydrate Responsive-Element Binding Protein (ChREBP) is a sugar sensing transcription factor that mediates genomic responses to changes in carbohydrate abundance in key metabolic tissues. Read More

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Pancreas preservation with amphotericin B deteriorates islet yield for porcine islet isolation.

Xenotransplantation 2021 Apr 2:e12690. Epub 2021 Apr 2.

Department of Regenerative Medicine, Graduate School of Medicine, University of the Ryukyus, Nishihara, Japan.

Background: Amphotericin B is a crucial agent in the management of serious systemic fungal infections. It is also known to be cytotoxic. In this study, we evaluated the effect of amphotericin B added to the preservation solution on islet yield during islet isolation. Read More

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Generation of a Novel Nkx6-1 Venus Fusion Reporter Mouse Line.

Int J Mol Sci 2021 Mar 26;22(7). Epub 2021 Mar 26.

Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany.

Nkx6-1 is a member of the Nkx family of homeodomain transcription factors (TFs) that regulates motor neuron development, neuron specification and pancreatic endocrine and β-cell differentiation. To facilitate the isolation and tracking of Nkx6-1-expressing cells, we have generated a novel Nkx6-1 Venus fusion (Nkx6-1-VF) reporter allele. The Nkx6-1-VF knock-in reporter is regulated by endogenous cis-regulatory elements of Nkx6-1 and the fluorescent protein fusion does not interfere with the TF function, as homozygous mice are viable and fertile. Read More

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Redox Homeostasis in Pancreatic β-Cells: From Development to Failure.

Antioxidants (Basel) 2021 Mar 27;10(4). Epub 2021 Mar 27.

Department of Mitochondrial Physiology, Institute of Physiology, Czech Academy of Sciences, 142 20 Prague 4, Czech Republic.

Redox status is a key determinant in the fate of β-cell. These cells are not primarily detoxifying and thus do not possess extensive antioxidant defense machinery. However, they show a wide range of redox regulating proteins, such as peroxiredoxins, thioredoxins or thioredoxin reductases, etc. Read More

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Ramatroban-Based Analogues Containing Fluorine Group as Potential F-Labeled Positron Emission Tomography (PET) G-Protein Coupled Receptor 44 (GPR44) Tracers.

Molecules 2021 Mar 6;26(5). Epub 2021 Mar 6.

Department of Translational Research & Cellular Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.

Diabetes remains one of the fastest growing chronic diseases and is a leading source of morbidity and accelerated mortality in the world. Loss of beta cell mass (BCM) and decreased sensitivity to insulin underlie diabetes pathogenesis. Yet, the ability to safely and directly assess BCM in individuals with diabetes does not exist. Read More

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Bionic Organs: Shear Forces Reduce Pancreatic Islet and Mammalian Cell Viability during the Process of 3D Bioprinting.

Micromachines (Basel) 2021 Mar 14;12(3). Epub 2021 Mar 14.

Foundation of Research and Science Development, 01-793 Warsaw, Poland.

Background: 3D bioprinting is the future of constructing functional organs. Creating a bioactive scaffold with pancreatic islets presents many challenges. The aim of this paper is to assess how the 3D bioprinting process affects islet viability. Read More

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Combination of human tau and islet amyloid polypeptide exacerbates metabolic dysfunction in transgenic mice.

J Pathol 2021 Apr 2. Epub 2021 Apr 2.

Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.

Amyloid plaques and neurofibrillary tangles composed of hyperphosphorylated tau are important contributors to Alzheimer's disease (AD). Tau also impacts pancreatic beta cell function and glucose homeostasis. Amyloid deposits composed of islet amyloid polypeptide (IAPP) are a pathological feature of type 2 diabetes (T2D). Read More

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Oestrogen receptor α in T cells controls the T cell immune profile and glucose metabolism in mouse models of gestational diabetes mellitus.

Diabetologia 2021 Apr 1. Epub 2021 Apr 1.

Department of Clinical Pharmacology, University of Toyama, Toyama, Japan.

Aims/hypothesis: The imbalance between maternal insulin resistance and a relative lack of insulin secretion underlies the pathogenesis of gestational diabetes mellitus (GDM). Alterations in T cell subtypes and increased levels of circulating proinflammatory cytokines have been proposed as potential mechanisms underlying the pathophysiology of insulin resistance in GDM. Since oestrogen modulates T cell immunity, we hypothesised that oestrogen plays a homeostatic role in visceral adipose tissue by coordinating T cell immunity through oestrogen receptor α (ERα) in T cells to prevent GDM. Read More

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Single-cell chromatin accessibility identifies pancreatic islet cell type- and state-specific regulatory programs of diabetes risk.

Nat Genet 2021 04 1;53(4):455-466. Epub 2021 Apr 1.

Department of Pediatrics, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA, USA.

Single-nucleus assay for transposase-accessible chromatin using sequencing (snATAC-seq) creates new opportunities to dissect cell type-specific mechanisms of complex diseases. Since pancreatic islets are central to type 2 diabetes (T2D), we profiled 15,298 islet cells by using combinatorial barcoding snATAC-seq and identified 12 clusters, including multiple alpha, beta and delta cell states. We cataloged 228,873 accessible chromatin sites and identified transcription factors underlying lineage- and state-specific regulation. Read More

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Why pancreatic islets should be regarded and regulated like organs.

CellR4 Repair Replace Regen Reprogram 2021 16;9. Epub 2021 Mar 16.

Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA.

There are strong reasons to say that pancreatic islets are organs before they are isolated and that they should be considered to be organs once transplanted. Thus, taking into account how much we have learned about the structure and function of islet micro-organs, it seems highly illogical to on one hand consider autologous islets be regulated as organ transplants and alloislets to be regulated with the very restrictive rules used for cell transplantation. It is particularly problematic that this policy has led to restrictions that have made it next to impossible for transplants of alloislets to be carried out in the US, which is a very sad situation for the country that made so many of the advances that brought islet transplantation to the clinic. Read More

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Theoretical study of the interactions between peptide tyrosine tyrosine [PYY (1-36)], a newly identified modulator in type 2 diabetes pathophysiology, with receptors NPY1R and NPY4R.

Hormones (Athens) 2021 Mar 29. Epub 2021 Mar 29.

Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius.

Purpose: Diabetes mellitus is a common condition in the clinically obese. Bariatric surgery is one of the ways to put type 2 diabetes in remission. Recent findings propose the appetite-regulator peptide tyrosine tyrosine (PYY) as a therapeutic option for patients with type 2 diabetes. Read More

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A Dual Systems Genetics Approach Identifies Common Genes, Networks, and Pathways for Type 1 and 2 Diabetes in Human Islets.

Front Genet 2021 10;12:630109. Epub 2021 Mar 10.

Department of Translational T1D Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark.

Type 1 and 2 diabetes (T1/2D) are complex metabolic diseases caused by absolute or relative loss of functional β-cell mass, respectively. Both diseases are influenced by multiple genetic loci that alter disease risk. For many of the disease-associated loci, the causal candidate genes remain to be identified. Read More

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Lessons from Human Islet Transplantation Inform Stem Cell-Based Approaches in the Treatment of Diabetes.

Front Endocrinol (Lausanne) 2021 11;12:636824. Epub 2021 Mar 11.

Department of Pediatrics, School of Medicine, University of Minnesota, Minneapolis, MN, United States.

Diabetes mellitus is characterized by the body's inability to control blood glucose levels within a physiological range due to loss and/or dysfunction of insulin producing beta cells. Progressive beta cell loss leads to hyperglycemia and if untreated can lead to severe complications and/or death. Treatments at this time are limited to pharmacologic therapies, including exogenous insulin or oral/injectable agents that improve insulin sensitivity or augment endogenous insulin secretion. Read More

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