المؤلفون: Joakim Lehrstrand, Wayne I. L. Davies, Max Hahn, Olle Korsgren, Tomas Alanentalo, Ulf Ahlgren

المصدر: Nature Communications, Vol 15, Iss 1, Pp 1-11 (2024)

مصطلحات موضوعية: Science

الوصف: Abstract Pancreatic islets of Langerhans play a pivotal role in regulating blood glucose homeostasis, but critical information regarding their mass, distribution and composition is lacking within a whole organ context. Here, we apply a 3D imaging pipeline to generate a complete account of the insulin-producing islets throughout the human pancreas at a microscopic resolution and within a maintained spatial 3D context. These data show that human islets are far more heterogenous than previously accounted for with regards to their size distribution and cellular make up. By deep tissue 3D imaging, this in-depth study demonstrates that 50% of the human insulin-expressing islets are virtually devoid of glucagon-producing α-cells, an observation with significant implications for both experimental and clinical research.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2041-1723Test

الوصول الحر: https://doaj.org/article/18b63b142e3143c1a39ed8bf5f93f484Test

المؤلفون: Max Hahn, Christoffer Nord, Maria Eriksson, Federico Morini, Tomas Alanentalo, Olle Korsgren, Ulf Ahlgren

المصدر: Communications Biology, Vol 4, Iss 1, Pp 1-10 (2021)

مصطلحات موضوعية: Biology (General), QH301-705.5

الوصف: Hahn et al. present a method to visualize the endocrine human pancreas in 3D and calculate volumetric data. Using immunolabeling to visualize targets of interest and in reconstructing large tissue parts from imaged cm3-sized tissue blocks, they use their method to reveal previously unknown morphological differences in the endocrine pancreas affected with type 2 diabetes.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2399-3642Test

الوصول الحر: https://doaj.org/article/ff0e0e30412a4b51b096a7392d402b2fTest

المؤلفون: Tomas Alanentalo, Max Hahn, Stefanie M. A. Willekens, Ulf Ahlgren

المصدر: Frontiers in Endocrinology, Vol 12 (2021)

مصطلحات موضوعية: mesoscopic imaging, optical projection tomography, light sheet fluorescence microscopy, pancreas, diabetes, Diseases of the endocrine glands. Clinical endocrinology, RC648-665

الوصف: The exocrine-endocrine multipart organization of the pancreas makes it an exceedingly challenging organ to analyze, quantitatively and spatially. Both in rodents and humans, estimates of the pancreatic cellular composition, including beta-cell mass, has been largely relying on the extrapolation of 2D stereological data originating from limited sample volumes. Alternatively, they have been obtained by low resolution non-invasive imaging techniques providing little detail regarding the anatomical organization of the pancreas and its cellular and/or molecular make up. In this mini-review, the state of the art and the future potential of currently existing and emerging high-resolution optical imaging techniques working in the mm-cm range with μm resolution, here referred to as mesoscopic imaging approaches, will be discussed regarding their contribution toward a better understanding of pancreatic anatomy both in normal conditions and in the diabetic setting. In particular, optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) imaging of the pancreas and their associated tissue processing and computational analysis protocols will be discussed in the light of their current capabilities and future potential to obtain more detailed 3D-spatial, quantitative, and molecular information of the pancreas.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fendo.2021.633063/fullTest; https://doaj.org/toc/1664-2392Test

الوصول الحر: https://doaj.org/article/9439a4aab31144169149a6c3fc18be8cTest

المؤلفون: Katharina Borst, Sven Flindt, Patrick Blank, Pia-Katharina Larsen, Chintan Chhatbar, Jennifer Skerra, Julia Spanier, Christoph Hirche, Martin König, Tomas Alanentalo, Martin Hafner, Zoe Waibler, Klaus Pfeffer, Veronika Sexl, Gerd Sutter, Werner Müller, Theresa Graalmann, Ulrich Kalinke

المصدر: PLoS Pathogens, Vol 16, Iss 2, p e1008279 (2020)

مصطلحات موضوعية: Immunologic diseases. Allergy, RC581-607, Biology (General), QH301-705.5

الوصف: IFN-γ is an enigmatic cytokine that shows direct anti-viral effects, confers upregulation of MHC-II and other components relevant for antigen presentation, and that adjusts the composition and balance of complex cytokine responses. It is produced during immune responses by innate as well as adaptive immune cells and can critically affect the course and outcome of infectious diseases, autoimmunity, and cancer. To selectively analyze the function of innate immune cell-derived IFN-γ, we generated conditional IFN-γOFF mice, in which endogenous IFN-γ expression is disrupted by a loxP flanked gene trap cassette inserted into the first intron of the IFN-γ gene. IFN-γOFF mice were intercrossed with Ncr1-Cre or CD4-Cre mice that express Cre mainly in NK cells (IFN-γNcr1-ON mice) or T cells (IFN-γCD4-ON mice), respectively. Rosa26RFP reporter mice intercrossed with Ncr1-Cre mice showed selective RFP expression in more than 80% of the NK cells, while upon intercrossing with CD4-Cre mice abundant RFP expression was detected in T cells, but also to a minor extent in other immune cell subsets. Previous studies showed that IFN-γ expression is needed to promote survival of vaccinia virus (VACV) infection. Interestingly, during VACV infection of wild type and IFN-γCD4-ON mice two waves of serum IFN-γ were induced that peaked on day 1 and day 3/4 after infection. Similarly, VACV infected IFN-γNcr1-ON mice mounted two waves of IFN-γ responses, of which the first one was moderately and the second one profoundly reduced when compared with WT mice. Furthermore, IFN-γNcr1-ON as well as IFN-γCD4-ON mice survived VACV infection, whereas IFN-γOFF mice did not. As expected, ex vivo analysis of splenocytes derived from VACV infected IFN-γNcr1-ON mice showed IFN-γ expression in NK cells, but not T cells, whereas IFN-γOFF mice showed IFN-γ expression neither in NK cells nor T cells. VACV infected IFN-γNcr1-ON mice mounted normal cytokine responses, restored neutrophil accumulation, and showed normal myeloid cell distribution in blood and spleen. Additionally, in these mice normal MHC-II expression was detected on peripheral macrophages, whereas IFN-γOFF mice did not show MHC-II expression on such cells. In conclusion, upon VACV infection Ncr1 positive cells including NK cells mount two waves of early IFN-γ responses that are sufficient to promote the induction of protective anti-viral immunity.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1553-7366Test; https://doaj.org/toc/1553-7374Test

الوصول الحر: https://doaj.org/article/5b7976512ad24a3da14b6b045aff5664Test

المؤلفون: Violeta Georgieva Tsonkova, Fredrik Wolfhagen Sand, Xenia Asbæk Wolf, Lars Groth Grunnet, Anna Kirstine Ringgaard, Camilla Ingvorsen, Louise Winkel, Mark Kalisz, Kevin Dalgaard, Christine Bruun, Johannes Josef Fels, Charlotte Helgstrand, Sven Hastrup, Fredrik Kryh Öberg, Erik Vernet, Michael Paolo Bastner Sandrini, Allan Christian Shaw, Carsten Jessen, Mads Grønborg, Jacob Hald, Hanni Willenbrock, Dennis Madsen, Rasmus Wernersson, Lena Hansson, Jan Nygaard Jensen, Annette Plesner, Tomas Alanentalo, Maja Borup Kjær Petersen, Anne Grapin-Botton, Christian Honoré, Jonas Ahnfelt-Rønne, Jacob Hecksher-Sørensen, Philippe Ravassard, Ole D. Madsen, Claude Rescan, Thomas Frogne

المصدر: Molecular Metabolism, Vol 8, Iss , Pp 144-157 (2018)

مصطلحات موضوعية: Internal medicine, RC31-1245

الوصف: Objective: To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. Methods: EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. Results: Transplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins.Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate.By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation.ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. Conclusions: Overall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active cytokine induced caspase 3/7 apoptotic pathway and is responsive to ER stress initiation factors. The cells' ability to proliferate can be further increased by already known compounds as well as by novel peptides and proteins. Based on its robust performance during the functionality assessment assays, the EndoC-βH1 cell line was successfully used as a screening platform for identification of novel anti-diabetic drug candidates. Keywords: EndoC-βH1, Pseudoislets, Glucose stimulated insulin secretion, Somatostatin signaling, Proliferation

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2212877817308451Test; https://doaj.org/toc/2212-8778Test

الوصول الحر: https://doaj.org/article/87dc16429b2843beab1b7a3a86b28d77Test

المؤلفون: Maj Petersen, Prafull S. Gandhi, Jens Buchardt, Tomas Alanentalo, Johannes Josef Fels, Nils Langeland Johansen, Peter Helding-Kvist, Knud Vad, Peter Thygesen

المصدر: International Journal of Molecular Sciences, Vol 21, Iss 4, p 1181 (2020)

مصطلحات موضوعية: somapacitan, human growth hormone, receptor signaling, p-stat5 activation, biodistribution, fluorescence molecular tomography, light-sheet fluorescence microscopy, proximal epiphysis, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: Somapacitan is a long-acting, once-weekly, albumin-binding growth hormone (GH) derivative. The reversible albumin-binding properties leads to prolonged circulation half-life. Here, we investigated and compared somapacitan with human GH on downstream receptor signaling in primary hepatocytes and hepatocellular models and using isothermal titration calorimetry to characterize receptor binding of somapacitan in the presence or absence of human serum albumin (HSA). With non-invasive fluorescence imaging we quantitatively visualize and compare the temporal distribution and examine the tissue-specific growth hormone receptor (GHR) activation at distribution sites. We found that signaling kinetics were slightly more rapid and intense for GH compared with somapacitan. Receptor binding isotherms were characterized by a high and a low affinity interaction site with or without HSA. Using in vivo optical imaging we found prolonged systemically biodistribution of somapacitan compared with GH, which correlated with plasma pharmacokinetics. Ex vivo mouse organ analysis revealed that the temporal fluorescent intensity in livers dosed with somapacitan was significantly increased compared with GH-dosed livers and correlated with the degree of downstream GHR activation. Finally, we show that fluorescent-labeled analogs distributed to the hypertrophic zone in the epiphysis of proximal tibia of hypophysectomized rats and that somapacitan and GH activate the GHR signaling in epiphyseal tissues.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1422-0067/21/4/1181Test; https://doaj.org/toc/1422-0067Test

الوصول الحر: https://doaj.org/article/b6e20898e3814bc7a7e1b4d981469a96Test

المؤلفون: Tomas Alanentalo, Federico Morini, Ulf Ahlgren, Christoffer Nord, Martin Isaksson Mettävainio, Oskar Franklin, Maria Eriksson, Malin Sund, Olle Korsgren, Max Hahn

المصدر: Scientific Reports, Vol 10, Iss 1, Pp 1-11 (2020)
Scientific Reports

مصطلحات موضوعية: Pathology, medicine.medical_specialty, lcsh:Medicine, Gastroenterology and Hepatology, Article, Islets of Langerhans, Imaging, Three-Dimensional, Pancreatic cancer, Tumor Microenvironment, medicine, Carcinoma, Gastroenterologi, Humans, Tomography, Optical, Tissue autofluorescence, lcsh:Science, Pancreas, Pathological, Cancer och onkologi, geography, Tumor microenvironment, Multidisciplinary, geography.geographical_feature_category, business.industry, Kirurgi, Optical Imaging, lcsh:R, Islet, medicine.disease, Pathophysiology, Pancreatic Neoplasms, Cancer and Oncology, Immunohistochemistry, Surgery, lcsh:Q, business, Carcinoma, Pancreatic Ductal

الوصف: The possibility to assess pancreatic anatomy with microscopic resolution in three dimensions (3D) would significantly add to pathological analyses of disease processes. Pancreatic ductal adenocarcinoma (PDAC) has a bleak prognosis with over 90% of the patients dying within 5 years after diagnosis. Cure can be achieved by surgical resection, but the efficiency remains drearily low. Here we demonstrate a method that without prior immunohistochemical labelling provides insight into the 3D microenvironment and spread of PDAC and premalignant cysts in intact surgical biopsies. The method is based solely on the autofluorescent properties of the investigated tissues using optical projection tomography and/or light-sheet fluorescence microscopy. It does not interfere with subsequent histopathological analysis and may facilitate identification of tumor-free resection margins within hours. We further demonstrate how the developed approach can be used to assess individual volumes and numbers of the islets of Langerhans in unprecedently large biopsies of human pancreatic tissue, thus providing a new means by which remaining islet mass may be assessed in settings of diabetes. Generally, the method may provide a fast approach to provide new anatomical insight into pancreatic pathophysiology.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::37a800c5cf28003f9efb12a3801a7948Test
http://link.springer.com/article/10.1038/s41598-020-74616-6Test

المؤلفون: Elena Kostromina, Christoffer Nord, Tomas Alanentalo, Federico Morini, Per Olof Berggren, Yan Xiong, Erwin Ilegems, Jürgen Mayer, Pim P van Krieken, James Sharpe, Ulf Ahlgren, Teresa Pereira, Maria Eriksson, Jorge L. Ruas, Max Hahn

المصدر: Communications Biology, Vol 3, Iss 1, Pp 1-14 (2020)
Communications Biology

مصطلحات موضوعية: Male, 0301 basic medicine, endocrine system diseases, Cell- och molekylärbiologi, Cell, Medicine (miscellaneous), Optical imaging, Mice, 0302 clinical medicine, 3-D reconstruction, Insulin-Secreting Cells, Insulin, lcsh:QH301-705.5, Glucose Transporter Type 2, Microscopy, Confocal, geography.geographical_feature_category, biology, Diabetes, Islet, Experimental models of disease, Mechanisms of disease, medicine.anatomical_structure, Endokrinologi och diabetes, General Agricultural and Biological Sciences, medicine.drug, endocrine system, medicine.medical_specialty, Down-Regulation, 030209 endocrinology & metabolism, Endocrinology and Diabetes, Article, General Biochemistry, Genetics and Molecular Biology, Diabetes Mellitus, Experimental, Islets of Langerhans, 03 medical and health sciences, Microscopy, Electron, Transmission, Downregulation and upregulation, Internal medicine, Diabetes mellitus, medicine, Animals, geography, Glucose transporter, nutritional and metabolic diseases, medicine.disease, Streptozotocin, Mice, Inbred C57BL, Transplantation, 030104 developmental biology, Endocrinology, Microscopy, Fluorescence, lcsh:Biology (General), biology.protein, GLUT2, Cell and Molecular Biology, Biomarkers

الوصف: Mouse models of Streptozotocin (STZ) induced diabetes represent the most widely used preclinical diabetes research systems. We applied state of the art optical imaging schemes, spanning from single islet resolution to the whole organ, providing a first longitudinal, 3D-spatial and quantitative account of β-cell mass (BCM) dynamics and islet longevity in STZ-treated mice. We demonstrate that STZ-induced β-cell destruction predominantly affects large islets in the pancreatic core. Further, we show that hyperglycemic STZ-treated mice still harbor a large pool of remaining β-cells but display pancreas-wide downregulation of glucose transporter type 2 (GLUT2). Islet gene expression studies confirmed this downregulation and revealed impaired β-cell maturity. Reversing hyperglycemia by islet transplantation partially restored the expression of markers for islet function, but not BCM. Jointly our results indicate that STZ-induced hyperglycemia results from β-cell dysfunction rather than β-cell ablation and that hyperglycemia in itself sustains a negative feedback loop restraining islet function recovery.
Hahn, van Krieken et al. provide a quantitative account of β-cell mass dynamics and islet longevity in mice treated with Streptozotocin (STZ). They find that STZ-induced hyperglycemia primarily results from β-cell dysfunction rather than its ablation. This study provides insights into how the most widely used preclinical diabetes model works.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6ba990408233453663d8fd8eb4c76959Test
http://link.springer.com/article/10.1038/s42003-020-01243-2Test

المؤلفون: Barbara Leibiger, Stefan Jacob, Tomas Alanentalo, Martin Köhler, Montse Visa, Tilo Moede, Per Olof Berggren, Philip Tröster, Ingo B. Leibiger, Concha F. García-Prieto

المصدر: The FASEB Journal

مصطلحات موضوعية: 0301 basic medicine, medicine.medical_specialty, Population, Context (language use), Biochemistry, 03 medical and health sciences, 0302 clinical medicine, In vivo, Internal medicine, Genetics, medicine, Glucose homeostasis, education, Molecular Biology, education.field_of_study, geography, geography.geographical_feature_category, Chemistry, Pancreatic islets, Islet, In vitro, 3. Good health, 030104 developmental biology, Endocrinology, medicine.anatomical_structure, 030217 neurology & neurosurgery, Preclinical imaging, Biotechnology

الوصف: The dynamics of cytoplasmic free Ca2+ concentration ([Ca2+]i) in pancreatic β cells is central to our understanding of β-cell physiology and pathology. In this context, there are numerous in vitro studies available but existing in vivo data are scarce. We now critically evaluate the anterior chamber of the eye as an in vivo, non-invasive, imaging site for measuring [Ca2+]i dynamics longitudinally in three dimensions and at single-cell resolution. By applying a fluorescently labeled glucose analogue 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose in vivo, we followed how glucose almost simultaneously distributes to all cells within the islet volume, resulting in [Ca2+]i changes. We found that almost all β cells in healthy mice responded to a glucose challenge, while in hyperinsulinemic, hyperglycemic mice about 80% of the β cells could not be further stimulated from fasting basal conditions. This finding indicates that our imaging modality can resolve functional heterogeneity within the β-cell population in terms of glucose responsiveness. Importantly, we demonstrate that glucose homeostasis is markedly affected using isoflurane compared to hypnorm/midazolam anesthetics, which has major implications for [Ca2+]i measurements. In summary, this setup offers a powerful tool to further investigate in vivo pancreatic β-cell [Ca2+]i response patterns at single-cell resolution in health and disease.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f87522c9c8363f3c1c243d30b4dacc5fTest
https://doi.org/10.1096/fj.201901302rrTest

المؤلفون: Olle Korsgren, Tomas Alanentalo, Max Hahn, Federico Morini, Christoffer Nord, Maria Eriksson, Ulf Ahlgren

المصدر: Communications Biology, Vol 4, Iss 1, Pp 1-10 (2021)

مصطلحات موضوعية: Male, Pathology, medicine.medical_specialty, QH301-705.5, Cell- och molekylärbiologi, Medicine (miscellaneous), Context (language use), Biology, Endocrinology and Diabetes, General Biochemistry, Genetics and Molecular Biology, Immunolabeling, Islets of Langerhans, Imaging, Three-Dimensional, medicine, Specific labelling, Endocrine system, Humans, Biology (General), Organ system, Aged, Volumetric data, medicine.anatomical_structure, Human pancreas, Endokrinologi och diabetes, General Agricultural and Biological Sciences, Pancreas, Cell and Molecular Biology

الوصف: The possibility to quantitatively study specific molecular/cellular features of complete human organs with preserved spatial 3D context would have widespread implications for pre-clinical and clinical medicine. Whereas optical 3D imaging approaches have experienced a formidable revolution, they have remained limited due to current incapacities in obtaining specific labelling within large tissue volumes. We present a simple approach enabling reconstruction of antibody labeled cells within entire human organs with preserved organ context. We demonstrate the utility of the approach by providing volumetric data and 3D distribution of hundreds of thousands of islets of Langerhans within the human pancreas. By assessments of pancreata from non-diabetic and type 2 diabetic individuals, we display previously unrecognized features of the human islet mass distribution and pathology. As such, this method may contribute not only in unraveling new information of the pancreatic anatomy/pathophysiology, but it may be translated to essentially any antibody marker or organ system. Hahn et al. present a method to visualize the endocrine human pancreas in 3D and calculate volumetric data. Using immunolabeling to visualize targets of interest and in reconstructing large tissue parts from imaged cm3-sized tissue blocks, they use their method to reveal previously unknown morphological differences in the endocrine pancreas affected with type 2 diabetes.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7d4895f1c6de67b5f47fba1128e54117Test
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187770Test