Read by QxMD icon Read


Masaya Oshima, Klaus-Peter Knoch, Marc Diedisheim, Antje Petzold, Pierre Cattan, Marco Bugliani, Piero Marchetti, Pratik Choudhary, Guo-Cai Huang, Stefan R Bornstein, Michele Solimena, Olivier Albagli-Curiel, Raphael Scharfmann
Type 1 diabetes (T1D) is a chronic disease characterized by an autoimmune-mediated destruction of insulin-producing pancreatic β cells. Environmental factors such as viruses play an important role in the onset of T1D and interact with predisposing genes. Recent data suggest that viral infection of human islets leads to a decrease in insulin production rather than β cell death, suggesting loss of β cell identity. We undertook this study to examine whether viral infection could induce human β cell dedifferentiation...
February 8, 2018: JCI Insight
Elisa Monzón-Casanova, Michael Screen, Manuel D Díaz-Muñoz, Richard M R Coulson, Sarah E Bell, Greta Lamers, Michele Solimena, Christopher W J Smith, Martin Turner
Antibody affinity maturation occurs in germinal centers (GCs), where B cells cycle between the light zone (LZ) and the dark zone. In the LZ, GC B cells bearing immunoglobulins with the highest affinity for antigen receive positive selection signals from helper T cells, which promotes their rapid proliferation. Here we found that the RNA-binding protein PTBP1 was needed for the progression of GC B cells through late S phase of the cell cycle and for affinity maturation. PTBP1 was required for proper expression of the c-MYC-dependent gene program induced in GC B cells receiving T cell help and directly regulated the alternative splicing and abundance of transcripts that are increased during positive selection to promote proliferation...
January 22, 2018: Nature Immunology
Michele Solimena, Anke M Schulte, Lorella Marselli, Florian Ehehalt, Daniela Richter, Manuela Kleeberg, Hassan Mziaut, Klaus-Peter Knoch, Julia Parnis, Marco Bugliani, Afshan Siddiq, Anne Jörns, Frédéric Burdet, Robin Liechti, Mara Suleiman, Daniel Margerie, Farooq Syed, Marius Distler, Robert Grützmann, Enrico Petretto, Aida Moreno-Moral, Carolin Wegbrod, Anke Sönmez, Katja Pfriem, Anne Friedrich, Jörn Meinel, Claes B Wollheim, Gustavo B Baretton, Raphael Scharfmann, Everson Nogoceke, Ezio Bonifacio, Dorothée Sturm, Birgit Meyer-Puttlitz, Ugo Boggi, Hans-Detlev Saeger, Franco Filipponi, Mathias Lesche, Paolo Meda, Andreas Dahl, Leonore Wigger, Ioannis Xenarios, Mario Falchi, Bernard Thorens, Jürgen Weitz, Krister Bokvist, Sigurd Lenzen, Guy A Rutter, Philippe Froguel, Manon von Bülow, Mark Ibberson, Piero Marchetti
AIMS/HYPOTHESIS: Pancreatic islet beta cell failure causes type 2 diabetes in humans. To identify transcriptomic changes in type 2 diabetic islets, the Innovative Medicines Initiative for Diabetes: Improving beta-cell function and identification of diagnostic biomarkers for treatment monitoring in Diabetes (IMIDIA) consortium ( ) established a comprehensive, unique multicentre biobank of human islets and pancreas tissues from organ donors and metabolically phenotyped pancreatectomised patients (PPP)...
March 2018: Diabetologia
Barbara Ludwig, Stefan Ludwig, Anja Steffen, Yvonne Knauf, Baruch Zimerman, Sophie Heinke, Susann Lehmann, Undine Schubert, Janine Schmid, Martina Bleyer, Uwe Schönmann, Clark K Colton, Ezio Bonifacio, Michele Solimena, Andreas Reichel, Andrew V Schally, Avi Rotem, Uriel Barkai, Helena Grinberg-Rashi, Franz-Josef Kaup, Yuval Avni, Peter Jones, Stefan R Bornstein
Transplantation of pancreatic islets for treating type 1 diabetes is restricted to patients with critical metabolic lability resulting from the need for immunosuppression and the shortage of donor organs. To overcome these barriers, we developed a strategy to macroencapsulate islets from different sources that allow their survival and function without immunosuppression. Here we report successful and safe transplantation of porcine islets with a bioartificial pancreas device in diabetic primates without any immune suppression...
October 31, 2017: Proceedings of the National Academy of Sciences of the United States of America
Andreas Müller, Hassan Mziaut, Martin Neukam, Klaus-Peter Knoch, Michele Solimena
Insulin secretory granule (SG) turnover consists of several highly regulated processes allowing for proper β-cell function and insulin secretion. Besides the spatial distribution of insulin SGs, their age has great impact on the likelihood of their secretion and their behaviour within the β-cell. While quantitative measurements performed decades ago demonstrated the preferential secretion of young insulin, new experimental approaches aim to investigate insulin ageing at the granular level. Live-cell imaging, automated image analysis and correlative light and electron microscopy have fostered knowledge of age-defined insulin SG dynamics, their interaction with the cytoskeleton and ultrastructural features...
September 2017: Diabetes, Obesity & Metabolism
Christian M Cohrs, Chunguang Chen, Stephan R Jahn, Julia Stertmann, Helena Chmelova, Jürgen Weitz, Andrea Bähr, Nikolai Klymiuk, Anja Steffen, Barbara Ludwig, Virginia Kamvissi, Eckhard Wolf, Stefan R Bornstein, Michele Solimena, Stephan Speier
Islet-cell hormone release is modulated by signals from endothelial and endocrine cells within the islet. However, models of intraislet vascularization and paracrine cell signaling are mostly based on the rodent pancreas. We assessed the architecture and endocrine cell interaction of the vascular network in unperturbed human islets in situ and their potential to re-establish their endogenous vascular network after transplantation in vivo. We prepared slices of fresh pancreas tissue obtained from nondiabetic patients undergoing partial pancreatectomy...
May 1, 2017: Endocrinology
Andreas Müller, Martin Neukam, Anna Ivanova, Anke Sönmez, Carla Münster, Susanne Kretschmar, Yannis Kalaidzidis, Thomas Kurth, Jean-Marc Verbavatz, Michele Solimena
Correlative light and electron microscopy (CLEM) is a powerful approach to investigate the molecular ultrastructure of labeled cell compartments. However, quantitative CLEM studies are rare, mainly due to small sample sizes and the sensitivity of fluorescent proteins to strong fixatives and contrasting reagents for EM. Here, we show that fusion of a self-labeling protein to insulin allows for the quantification of age-distinct insulin granule pools in pancreatic beta cells by a combination of super resolution and transmission electron microscopy on Tokuyasu cryosections...
February 2, 2017: Scientific Reports
Gaelle R Carrat, Ming Hu, Marie-Sophie Nguyen-Tu, Pauline Chabosseau, Kyle J Gaulton, Martijn van de Bunt, Afshan Siddiq, Mario Falchi, Matthias Thurner, Mickaël Canouil, Francois Pattou, Isabelle Leclerc, Timothy J Pullen, Matthew C Cane, Priyanka Prabhala, William Greenwald, Anke Schulte, Piero Marchetti, Mark Ibberson, Patrick E MacDonald, Jocelyn E Manning Fox, Anna L Gloyn, Philippe Froguel, Michele Solimena, Mark I McCarthy, Guy A Rutter
Genetic variants near ARAP1 (CENTD2) and STARD10 influence type 2 diabetes (T2D) risk. The risk alleles impair glucose-induced insulin secretion and, paradoxically but characteristically, are associated with decreased proinsulin:insulin ratios, indicating improved proinsulin conversion. Neither the identity of the causal variants nor the gene(s) through which risk is conferred have been firmly established. Whereas ARAP1 encodes a GTPase activating protein, STARD10 is a member of the steroidogenic acute regulatory protein (StAR)-related lipid transfer protein family...
February 2, 2017: American Journal of Human Genetics
Marion Benazra, Marie-José Lecomte, Claire Colace, Andreas Müller, Cécile Machado, Severine Pechberty, Emilie Bricout-Neveu, Maud Grenier-Godard, Michele Solimena, Raphaël Scharfmann, Paul Czernichow, Philippe Ravassard
OBJECTIVES: Access to immortalized human pancreatic beta cell lines that are phenotypically close to genuine adult beta cells, represent a major tool to better understand human beta cell physiology and develop new therapeutics for Diabetes. Here we derived a new conditionally immortalized human beta cell line, EndoC-βH3 in which immortalizing transgene can be efficiently removed by simple addition of tamoxifen. METHODS: We used lentiviral mediated gene transfer to stably integrate a tamoxifen inducible form of CRE (CRE-ERT2) into the recently developed conditionally immortalized EndoC βH2 line...
December 2015: Molecular Metabolism
Laura Sosa, Juha M Torkko, María E Primo, Ramiro E Llovera, Pamela L Toledo, Antonella S Rios, F Luis Gonzalez Flecha, Aldana Trabucchi, Silvina N Valdez, Edgardo Poskus, Michele Solimena, Mario R Ermácora
BACKGROUND: ICA512 (or IA-2/PTPRN) is a transmembrane protein-tyrosine phosphatase located in secretory granules of neuroendocrine cells. Previous studies implied its involvement in generation, cargo storage, traffic, exocytosis and recycling of insulin secretory granules, as well as in β-cell proliferation. While several ICA512 domains have been characterized, the function and structure of a large portion of its N-terminal extracellular (or lumenal) region are unknown. Here, we report a biophysical, biochemical, and functional characterization of ICA512-RESP18HD, a domain comprising residues 35 to 131 and homologous to regulated endocrine-specific protein 18 (RESP18)...
May 2016: Biochimica et Biophysica Acta
Antje Petzold, Michele Solimena, Klaus-Peter Knoch
Type 1 diabetes (T1D) results from genetic predisposition and environmental factors leading to the autoimmune destruction of pancreatic beta cells. Recently, a rapid increase in the incidence of childhood T1D has been observed worldwide; this is too fast to be explained by genetic factors alone, pointing to the spreading of environmental factors linked to the disease. Enteroviruses (EVs) are perhaps the most investigated environmental agents in relationship to the pathogenesis of T1D. While several studies point to the likelihood of such correlation, epidemiological evidence in its support is inconclusive or in some instances even against it...
October 2015: Current Diabetes Reports
Florian Ehehalt, Dorothée Sturm, Manuela Rösler, Marius Distler, Jürgen Weitz, Stephan Kersting, Barbara Ludwig, Uta Schwanebeck, Hans-Detlev Saeger, Michele Solimena, Robert Grützmann
BACKGROUND AND AIM: Partial pancreatic resection is accompanied not only by a reduction in the islet cell mass but also by a variety of other factors that are likely to interfere with glucose metabolism. The aim of this work was to characterize the patient dynamics of blood glucose homeostasis during the course of partial pancreatic resection and to specify the associated clinico-pathological variables. METHODS: In total, 84 individuals undergoing elective partial pancreatic resection were consecutively recruited into this observational trial...
2015: PloS One
Erdinc Sezgin, Theresia Gutmann, Tomasz Buhl, Ron Dirkx, Michal Grzybek, Ünal Coskun, Michele Solimena, Kai Simons, Ilya Levental, Petra Schwille
Lateral compositional and physicochemical heterogeneity is a ubiquitous feature of cellular membranes on various length scales, from molecular assemblies to micrometric domains. Segregated lipid domains of increased local order, referred to as rafts, are believed to be prominent features in eukaryotic plasma membranes; however, their exact nature (i.e. size, lifetime, composition, homogeneity) in live cells remains difficult to define. Here we present evidence that both synthetic and natural plasma membranes assume a wide range of lipid packing states with varying levels of molecular order...
2015: PloS One
Jaber Dehghany, Peter Hoboth, Anna Ivanova, Hassan Mziaut, Andreas Müller, Yannis Kalaidzidis, Michele Solimena, Michael Meyer-Hermann
Insulin secretion from pancreatic β-cells in response to sudden glucose stimulation is biphasic. Prolonged secretion in vivo requires synthesis, delivery to the plasma membrane (PM) and exocytosis of insulin secretory granules (SGs). Here, we provide the first agent-based space-resolved model for SG dynamics in pancreatic β-cells. Using recent experimental data, we consider a single β-cell with identical SGs moving on a phenomenologically represented cytoskeleton network. A single exocytotic machinery mediates SG exocytosis on the PM...
August 2015: Traffic
Peter Hoboth, Andreas Müller, Anna Ivanova, Hassan Mziaut, Jaber Dehghany, Anke Sönmez, Martina Lachnit, Michael Meyer-Hermann, Yannis Kalaidzidis, Michele Solimena
Insulin secretion is key for glucose homeostasis. Insulin secretory granules (SGs) exist in different functional pools, with young SGs being more mobile and preferentially secreted. However, the principles governing the mobility of age-distinct SGs remain undefined. Using the time-reporter insulin-SNAP to track age-distinct SGs we now show that their dynamics can be classified into three components: highly dynamic, restricted, and nearly immobile. Young SGs display all three components, whereas old SGs are either restricted or nearly immobile...
February 17, 2015: Proceedings of the National Academy of Sciences of the United States of America
Juha M Torkko, M Evangelina Primo, Ronald Dirkx, Anne Friedrich, Antje Viehrig, Elisa Vergari, Barbara Borgonovo, Anke Sönmez, Carolin Wegbrod, Martina Lachnit, Carla Münster, Mauricio P Sica, Mario R Ermácora, Michele Solimena
The type 1 diabetes autoantigen ICA512/IA-2/RPTPN is a receptor protein tyrosine phosphatase of the insulin secretory granules (SGs) which regulates the size of granule stores, possibly via cleavage/signaling of its cytosolic tail. The role of its extracellular region remains unknown. Structural studies indicated that β2- or β4-strands in the mature ectodomain (ME ICA512) form dimers in vitro. Here we show that ME ICA512 prompts proICA512 dimerization in the endoplasmic reticulum. Perturbation of ME ICA512 β2-strand N-glycosylation upon S508A replacement allows for proICA512 dimerization, O-glycosylation, targeting to granules, and conversion, which are instead precluded upon G553D replacement in the ME ICA512 β4-strand...
March 2015: Molecular and Cellular Biology
S R Bornstein, S A Amiel, F Rubino, G Mingrone, V Kamvissi, M Solimena, E Bonifacio, P Jones, P Schwarz, A L Birkenfeld, A Behrens, A Barthel, R Lechler, M Peakman
No abstract text is available yet for this article.
December 12, 2014: Hormone and Metabolic Research, Hormon- und Stoffwechselforschung, Hormones et Métabolisme
S R Bornstein, S A Amiel, F Rubino, G Mingrone, V Kamvissi, M Solimena, E Bonifacio, P Jones, P Schwarz, A L Birkenfeld, A Behrens, A Barthel, R Lechler, M Peakman
No abstract text is available yet for this article.
January 2015: Hormone and Metabolic Research, Hormon- und Stoffwechselforschung, Hormones et Métabolisme
Martín E Noguera, María E Primo, Jean Jakoncic, Edgardo Poskus, Michele Solimena, Mario R Ermácora
Phogrin/IA-2β and ICA512/IA-2 are two paralogs receptor-type protein-tyrosine phosphatases (RPTP) that localize in secretory granules of various neuroendocrine cells. In pancreatic islet β-cells, they participate in the regulation of insulin secretion, ensuring proper granulogenesis, and β-cell proliferation. The role of their cytoplasmic tail has been partially unveiled, while that of their luminal region remains unclear. To advance the understanding of its structure-function relationship, the X-ray structure of the mature ectodomain of phogrin (ME phogrin) at pH 7...
March 2015: Journal of Structural and Functional Genomics
Klaus-Peter Knoch, Suchita Nath-Sain, Antje Petzold, Hendryk Schneider, Mike Beck, Carolin Wegbrod, Anke Sönmez, Carla Münster, Anne Friedrich, Merja Roivainen, Michele Solimena
Glucose and GLP-1 stimulate not only insulin secretion, but also the post-transcriptional induction of insulin granule biogenesis. This process involves the nucleocytoplasmic translocation of the RNA binding protein PTBP1. Binding of PTBP1 to the 3'-UTRs of mRNAs for insulin and other cargoes of beta cell granules increases their stability. Here we show that glucose enhances also the binding of PTBP1 to the 5'-UTRs of these transcripts, which display IRES activity, and their translation exclusively in a cap-independent fashion...
August 2014: Molecular Metabolism
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"