Islets最新文献

{"title":"A functional genomic approach to identify reference genes for human pancreatic beta cell real-time quantitative RT-PCR analysis.","authors":"Maria Inês Alvelos,&nbsp;Florian Szymczak,&nbsp;Ângela Castela,&nbsp;Sandra Marín-Cañas,&nbsp;Bianca Marmontel de Souza,&nbsp;Ioannis Gkantounas,&nbsp;Maikel Colli,&nbsp;Federica Fantuzzi,&nbsp;Cristina Cosentino,&nbsp;Mariana Igoillo-Esteve,&nbsp;Lorella Marselli,&nbsp;Piero Marchetti,&nbsp;Miriam Cnop,&nbsp;Décio L Eizirik","doi":"10.1080/19382014.2021.1948282","DOIUrl":"https://doi.org/10.1080/19382014.2021.1948282","url":null,"abstract":"<p><p>Exposure of human pancreatic beta cells to pro-inflammatory cytokines or metabolic stressors is used to model events related to type 1 and type 2 diabetes, respectively. Quantitative real-time PCR is commonly used to quantify changes in gene expression. The selection of the most adequate reference gene(s) for gene expression normalization is an important pre-requisite to obtain accurate and reliable results. There are no universally applicable reference genes, and the human beta cell expression of commonly used reference genes can be altered by different stressors. Here we aimed to identify the most stably expressed genes in human beta cells to normalize quantitative real-time PCR gene expression.We used comprehensive RNA-sequencing data from the human pancreatic beta cell line EndoC-βH1, human islets exposed to cytokines or the free fatty acid palmitate in order to identify the most stably expressed genes. Genes were filtered based on their level of significance (adjusted <i>P</i>-value >0.05), fold-change (|fold-change| <1.5) and a coefficient of variation <10%. Candidate reference genes were validated by quantitative real-time PCR in independent samples.We identified a total of 264 genes stably expressed in EndoC-βH1 cells and human islets following cytokines - or palmitate-induced stress, displaying a low coefficient of variation. Validation by quantitative real-time PCR of the top five genes <i>ARF1, CWC15, RAB7A, SIAH1</i> and <i>VAPA</i> corroborated their expression stability under most of the tested conditions. Further validation in independent samples indicated that the geometric mean of <i>ACTB</i> and <i>VAPA</i> expression can be used as a reliable normalizing factor in human beta cells.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 3-4","pages":"51-65"},"PeriodicalIF":2.2,"publicationDate":"2021-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2021.1948282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39168737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel mouse model expands potential human α-cell research.","authors":"Theodore Dos Santos,&nbsp;Patrick E MacDonald","doi":"10.1080/19382014.2021.1914507","DOIUrl":"https://doi.org/10.1080/19382014.2021.1914507","url":null,"abstract":"<p><p>A glucagon knock-out mouse with preserved GLP-1 and GLP-2 secretion allows for the improved study of transplanted human islets and glucagon responses- providing an unprecedented resource in human α-cell and diabetes research.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 3-4","pages":"80-83"},"PeriodicalIF":2.2,"publicationDate":"2021-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2021.1914507","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25589728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for the existence and potential roles of intra-islet glucagon-like peptide-1.","authors":"Scott A Campbell,&nbsp;Janyne Johnson,&nbsp;Peter E Light","doi":"10.1080/19382014.2021.1889941","DOIUrl":"https://doi.org/10.1080/19382014.2021.1889941","url":null,"abstract":"<p><p>Glucagon-Like Peptide-1 (GLP-1) is an important peptide hormone secreted by L-cells in the gastrointestinal tract in response to nutrients. It is produced by the differential cleavage of the proglucagon peptide. GLP-1 elicits a wide variety of physiological responses in many tissues that contribute to metabolic homeostasis. For these reasons, therapies designed to either increase endogenous GLP-1 levels or introduce exogenous peptide mimetics are now widely used in the management of diabetes. In addition to GLP-1 production from L-cells, recent reports suggest that pancreatic islet alpha cells may also synthesize and secrete GLP-1. Intra-islet GLP-1 may therefore play an unappreciated role in islet health and glucose regulation, suggesting a potential functional paracrine role for islet-derived GLP-1. In this review, we assess the current literature from an islet-centric point-of-view to better understand the production, degradation, and actions of GLP-1 within the endocrine pancreas in rodents and humans. The relevance of intra-islet GLP-1 in human physiology is discussed regarding the potential role of intra-islet GLP-1 in islet health and dysfunction.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 1-2","pages":"32-50"},"PeriodicalIF":2.2,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2021.1889941","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25482410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protein kinase C-θ knockout decreases serum IL-10 levels and inhibits insulin secretion from islet β cells.","authors":"Feng Hong,&nbsp;Yang Yang,&nbsp;Baiyi Chen,&nbsp;Peng Li,&nbsp;Guoguang Wang,&nbsp;Yuxin Jiang","doi":"10.1080/19382014.2021.1890963","DOIUrl":"https://doi.org/10.1080/19382014.2021.1890963","url":null,"abstract":"<p><p>Various subtypes of protein kinase C (PKC) are expressed in islet β cells and regulate β cell proliferation and survival. PKC-θ is distributed in the immune system and promotes the secretion of IL-10, which manifests a critical role in the onset of diabetes, by the immune cells. However, the role of PKC-θ in islets has not been concerned. In the present study, we investigated the role of PKC-θ in the protection of islet β cells and insulin secretion. Fasting glucose and insulin measurement, glucose tolerant test, immunofluorescence, and ELISA were conducted to study the influence of PKC-θ knockout on islet β cell survival and function, and explore the mechanism underlying this regulation. PKC-θ knockout mice at 2 weeks manifested normal serum insulin levels, glucose tolerance, and β cell mass. Knockout mice at 8 weeks show decreased β cell mass, but manifested normal insulin levels and glucose tolerance. Knockout mice at 16 weeks manifested impaired glucose tolerance, β cell mass, and decreased glucose stimulated insulin secretion. Furthermore, knockout mice manifested decreased serum IL-10 level compared with normal mice since 2 weeks. IL-10 injection into knockout mice improved glucose tolerance, serum insulin level, and reduced β cell mass, and IL-10 administration into cultured pancreatic tissue increased glucose stimulated insulin secretion. PKC-θ knockout decreases the secretion of IL-10, reduces β cell mass and insulin secretion in pancreatic islets. The present study illuminates the critical role of PKC-θ in protecting the survival and function of islet β cells.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 1-2","pages":"24-31"},"PeriodicalIF":2.2,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2021.1890963","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25479118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Failure mode and effect analysis in human islet isolation: from the theoretical to the practical risk.","authors":"Quentin Perrier,&nbsp;Vanessa Lavallard,&nbsp;Nadine Pernin,&nbsp;Charles-Henri Wassmer,&nbsp;David Cottet-Dumoulin,&nbsp;Fanny Lebreton,&nbsp;Kevin Bellofatto,&nbsp;Axel Andres,&nbsp;Ekaterine Berishvili,&nbsp;Domenico Bosco,&nbsp;Thierry Berney,&nbsp;Géraldine Parnaud","doi":"10.1080/19382014.2020.1856618","DOIUrl":"https://doi.org/10.1080/19382014.2020.1856618","url":null,"abstract":"<p><p>This study aimed to assess the global mapping risk of human islet isolation, using a failure mode and effect analysis (FMEA), and highlight the impact of quality assurance procedures on the risk level of criticality. Risks were scored using the risk priority number (RPN) scoring method. The risk level of criticality was made based on RPN and led to risk classification (low to critical). A raw risk analysis and a risk control analysis (with control means and quality assurance performance) were undertaken. The process of human islet isolation was divided into 11 steps, and 230 risks were identified. Analysis of the highest RPN of each of the 11 steps showed that the 4 highest risks were related to the pancreas digestion and islet purification stages. After implementation of reduction measures and controls, critical and severe risks were reduced by 3-fold and by 2-fold, respectively, so that 90% of risks could be considered as low to moderate. FMEA has proven to be a powerful approach for the identification of weaknesses in the islet isolation processes. The results demonstrated the importance of staff qualification and continuous training and supported the contribution of the quality assurance system to risk reduction.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 1-2","pages":"1-9"},"PeriodicalIF":2.2,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1856618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25392819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Culture, differentiation, and transduction of mouse E12.5 pancreatic spheres: an <i>in vitro</i> model for the secondary transition of pancreas development.","authors":"Lukas Huijbregts,&nbsp;Virginie Aiello,&nbsp;Andrea Soggia,&nbsp;Philippe Ravassard,&nbsp;Latif Rachdi,&nbsp;Raphaël Scharfmann,&nbsp;Olivier Albagli","doi":"10.1080/19382014.2020.1863723","DOIUrl":"https://doi.org/10.1080/19382014.2020.1863723","url":null,"abstract":"<p><p>During the secondary transition of rodent pancreatic development, mainly between E12.5 and E15.5 in mice, exocrine and endocrine populations differentiate from pancreatic progenitors. Here we describe an experimental system for its study <i>in vitro</i>. First, we show that spheres derived from dissociated E12.5 mouse pancreases differentiate within 7 days into most pancreatic exocrine and endocrine cell types, including beta cells. The proportion and spatial repartition of the different endocrine populations mirror those observed during normal development. Thus, dissociation and culture do not impair the developmental events affecting pancreatic progenitors during the secondary transition. Moreover, dissociated cells from mouse E12.5 pancreas were transduced with ecotropic MLV-based retroviral vectors or, though less efficiently, with a mixture of ALV(A)-based retroviral vectors and gesicles containing the TVA (Tumor Virus A) receptor. As an additional improvement, we also created a transgenic mouse line expressing TVA under the control of the 4.5 kB <i>pdx1</i> promoter (<i>pdx1</i>-TVA). We demonstrate that pancreatic progenitors from dissociated <i>pdx1</i>-TVA pancreas can be specifically transduced by ALV(A)-based retroviral vectors. Using this model, we expressed an activated mutant of the YAP transcriptional co-activator in pancreatic progenitors. These experiments indicate that deregulated YAP activity reduces endocrine and exocrine differentiation in the resulting spheres, confirming and extending previously published data. Thus, our experimental model recapitulates <i>in vitro</i> the crucial developmental decisions arising at the secondary transition and provides a convenient tool to study their genetic control.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"13 1-2","pages":"10-23"},"PeriodicalIF":2.2,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1863723","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25413243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cannabinoid receptors are differentially regulated in the pancreatic islets during the early development of metabolic syndrome.","authors":"Antonio Barajas-Martínez,&nbsp;Karina Bermeo,&nbsp;Lizbeth de la Cruz,&nbsp;Marina Martínez-Vargas,&nbsp;Ricardo Jesús Martínez-Tapia,&nbsp;David Erasmo García,&nbsp;Luz Navarro","doi":"10.1080/19382014.2020.1849927","DOIUrl":"https://doi.org/10.1080/19382014.2020.1849927","url":null,"abstract":"<p><p>The endocannabinoid system is found in tissues that regulate the glycemia, including adipose tissue, muscle, and pancreatic islets. Diet-induced metabolic syndrome changes the expression of the CB receptors in muscle, adipose tissue, and liver. However, it is poorly understood whether metabolic syndrome (MetS) affects the expression of CB receptors in pancreatic β cells. We analyzed the expression of CB receptors in pancreatic β cells under chronic high-sucrose diet (HSD)-induced MetS. Wistar rats fed an HSD as a model of MetS were used to investigate changes in cannabinoid receptors. After 8 weeks of treatment, we evaluated the appearance of the following MetS biomarkers: glucose intolerance, hyperinsulinemia, insulin resistance, hypertriglyceridemia, and an increase in visceral adiposity. To determine the presence of CB1 and CB2 receptors in pancreatic β cells, immunofluorescence of primary cell cultures and pancreatic sections was performed. For whole-islet quantification of membrane-bound CB1 and CB2 receptors, western-blotting following differential centrifugation was conducted. Our results revealed that an HSD treatment closely mimics the alterations seen in MetS. We observed that in primary cell culture, CB1 and CB2 receptors were expressed at a higher level in pancreatic β cells compared with non-β cells. MetS resulted in a reduction of CB1 in the islet, whereas abundant CB2 was observed after the treatment. CB1 and CB2 receptors are differentially expressed in pancreatic β cells during MetS development.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"12 6","pages":"134-144"},"PeriodicalIF":2.2,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1849927","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38687099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transplantation of rat pancreatic islets vitrified-warmed on the nylon mesh device and the silk fibroin sponge disc.","authors":"Kenyu Nakayama-Iwatsuki,&nbsp;Takahiro Yamanaka,&nbsp;Jun Negishi,&nbsp;Junki Teshima,&nbsp;Yasushi Tamada,&nbsp;Masumi Hirabayashi,&nbsp;Shinichi Hochi","doi":"10.1080/19382014.2020.1849928","DOIUrl":"https://doi.org/10.1080/19382014.2020.1849928","url":null,"abstract":"<p><p>We report the adaptability of rat islets vitrified-warmed on nylon mesh (NM) device or silk fibroin (SF) sponge disc for the normalization of the blood glucose level in rat models of diabetes. One-hundred rat islets were cryopreserved according to a minimum volume cooling protocol on an NM device or a solid surface vitrification protocol on an SF sponge disc. The recovery rate (97.1% vs. 93.8%), the viability (77.9% vs. 74.4%), and the stimulation index (4.7 vs. 4.2) in glucose-stimulated insulin secretion (GSIS) assay of the post-warm islets were comparable between the NM vitrification and the SF vitrification groups. The viability and the stimulation index of the fresh control islets were identified to be 97.5% and 6.5, respectively. Eight hundred islets from the NM or the SF vitrification group or the fresh control group were transplanted beneath the kidney capsule of a streptozotocin-induced diabetic rat (blood glucose level > 350 mg/dl). Within 3 weeks after transplantation, the acquisition of euglycemia (< 200 mg/dl) was observed in recipient rats (80.0-83.3%). An intraperitoneal glucose tolerance test on Day-30 and Day-60 showed similar 2-h responses to the glucose uptake of cured rats among the compared groups. Moreover, the successful engraftment of transplants was confirmed by the Day-70 nephrectomy through the subsequent diabetes reversal and histological evaluation. Thus, large quantities of rat islets vitrified-warmed on an NM device or an SF sponge disc were proven to be fully functional both in vitro and in vivo, due to the GSIS and syngeneic transplantation, respectively.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"12 6","pages":"145-155"},"PeriodicalIF":2.2,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1849928","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38687102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstructing human pancreatic islet architectures using computational optimization.","authors":"Gerardo J Félix-Martínez,&nbsp;Aurelio N Mata,&nbsp;J Rafael Godínez-Fernández","doi":"10.1080/19382014.2020.1823178","DOIUrl":"https://doi.org/10.1080/19382014.2020.1823178","url":null,"abstract":"<p><p>We outline a general methodology based on computational optimization and experimental data to reconstruct human pancreatic islet architectures. By using the nuclei coordinates of islet cells obtained through DAPI staining, cell types identified by immunostaining, and cell size distributions estimated from capacitance measurements, reconstructed islets composed of non-overlapping spherical cells were obtained through an iterative optimization procedure. In all cases, the reconstructed architectures included >99% of the experimental identified cells, each of them having a radius within the experimentally reported ranges. Given the wide use of mathematical modeling for the study of pancreatic cells, and recently, of cell-cell interactions within the pancreatic islets, the methodology here proposed, also capable of identifying cell-to-cell contacts, is aimed to provide with a framework for modeling and analyzing experimentally-based pancreatic islet architectures.</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"12 6","pages":"121-133"},"PeriodicalIF":2.2,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1823178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38519884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of α-ketoglutarate and the hypoxia sensing pathway in the regulation of pancreatic β-cell function.","authors":"M Hoang,&nbsp;J W Joseph","doi":"10.1080/19382014.2020.1802183","DOIUrl":"https://doi.org/10.1080/19382014.2020.1802183","url":null,"abstract":"<p><p>Anaplerosis and the associated mitochondrial metabolite transporters generate unique cytosolic metabolic signaling molecules that can regulate insulin release from pancreatic β-cells. It has been shown that mitochondrial metabolites, transported by the citrate carrier (CIC), dicarboxylate carrier (DIC), oxoglutarate carrier (OGC), and mitochondrial pyruvate carrier (MPC) play a vital role in the regulation of glucose-stimulated insulin secretion (GSIS). Metabolomic studies on static and biphasic insulin secretion, suggests that several anaplerotic derived metabolites, including α-ketoglutarate (αKG), are strongly associated with nutrient regulated insulin secretion. Support for a role of αKG in the regulation of insulin secretion comes from studies looking at αKG dependent enzymes, including hypoxia-inducible factor-prolyl hydroxylases (PHDs) in clonal β-cells, and rodent and human islets. This review will focus on the possible link between defective anaplerotic-derived αKG, PHDs, and the development of type 2 diabetes (T2D).</p>","PeriodicalId":14671,"journal":{"name":"Islets","volume":"12 5","pages":"108-119"},"PeriodicalIF":2.2,"publicationDate":"2020-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19382014.2020.1802183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38336250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}