Insulitis in human diabetes: a histological evaluation of donor pancreases

Aims/hypothesis According to the consensus criteria developed for type 1 diabetes, an individual can be diagnosed with insulitis when >= 15 CD45(+) cells are found within the parenchyma or in the islet-exocrine interface in >= 3 islets. The aim of this study was to determine the frequency of individuals with type 2 diabetes fulfilling these criteria with reference to non-diabetic and type 1 diabetic individuals. Methods Insulitis was determined by examining CD45(+) cells in the pancreases of 50, 13 and 44 organ donors with type 2 diabetes, type 1 diabetes and no diabetes, respectively. CD3(+) cells (T cells) infiltrating the islets were evaluated in insulitic donors. In insulitic donors with type 2 diabetes, the pancreases were characterised according to the presence of CD68 (macrophages), myeloperoxidase (MPO; neutrophils), CD3, CD20 (B cells) and HLA class I hyperstained islets. In all type 2 diabetic donors, potential correlations of insulitis with dynamic glucose-stimulated insulin secretion in vitro or age, BMI, HbA(1c) or autoantibody positivity were examined. Results Overall, 28% of the type 2 diabetic donors fulfilled the consensus criteria for insulitis developed for type 1 diabetes. Of the type 1 diabetic donors, 31% fulfilled the criteria. None of the non-diabetic donors met the criteria. Only type 1 diabetic donors had >= 15 CD3(+) cells in >= 3 islets. Type 2 diabetic donors with insulitis also had a substantial number of CD45(+) cells in the exocrine parenchyma. Macrophages constituted the largest fraction of CD45(+) cells, followed by neutrophils and T cells. Of type 2 diabetic pancreases with insulitis, 36% contained islets that hyperstained for HLA class I. Isolated islets from type 2 diabetic donors secreted less insulin than controls, although with preserved dynamics. Insulitis in the type 2 diabetic donors did not correlate with glucose-stimulated insulin secretion, the presence of autoantibodies, BMI or HbA(1c). Conclusions/interpretation The current definition of insulitis cannot be used to distinguish pancreases retrieved from individuals with type 1 diabetes from those with type 2 diabetes. On the basis of our findings, we propose a revised definition of insulitis, with a positive diagnosis when >= 15 CD3(+) cells, not CD45(+) cells, are found in >= 3 islets

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Running .NET Cross-Platform Application on Linux : Proof of concept of running .NET cross-platform application on Linux

This thesis was done for ABB Oy Distribution Solutions and consists of research and development regarding cross platform application development. The background for the task was that the employer wanted to investigate in the possibilities of creating cross platform applications with the technologies used at the company, primarily using Microsoft’s .NET platform. An existing application built by ABB using the Xamarin mobile framework was used as a basis for the research. The initial goal was to try and convert the mobile application to a desktop application, which would run on a Linux system. Because of the lack of support for creating graphical user interfaces for platforms other than Windows in .NET, plans were later changed. The final result was a web application, with the backend created with ASP .NET Core and the frontend created with React. Through this work it was shown that a web solution is sufficient in meeting the user interface needs of the application.Detta examensarbete gjordes på uppdrag av ABB Oy Distribution Solutions och består av forsknings och utvecklings arbete gällande plattformsoberoende applikationsutveckling. Ursprunget till examensarbetet var att arbetsgivaren önskade undersöka möjligheterna kring att skapa plattformsoberoende applikationer med de teknologier som används inom företaget, i synnerhet gällande Microsofts .NET. En existerande applikation byggd med Xamarin togs som grund för undersökningen. Ursprungligen planerades en Linux-skrivbordsapplikation att skapas utifrån den exiserande applikationen. På grund av det begränsade stödet för grafiska användargränssnitt för plattformar andra än Windows i .NET, ändrades planerna senare. Resultatet blev en webbapplikation där serverdelen skapades med ASP .NET Core och användargränssnittet skapades med React. Genom arbetet visades att en webblösning är tillräcklig för att möta applikationens behov på användargränssnitt.Tämä opinnäytetyö tehtiin ABB Oy Distribution Solutions yksikölle. Aiheena on monialustaisen sovelluksen kehittäminen. Tehtävän taustana oli, että työnantaja halusi tutkia mahdollisuuksia luoda monialustaisia sovelluksia käyttäen yritykselle tuttua teknologiaa eli Microsoftin .NET:ia. Tutkimuksen perustana käytettiin olemassa olevaa sovellusta, jonka ABB rakensi Xamarin mobiilikehyksen avulla. Alkuperäinen tavoite oli yrittää muuntaa mobiilisovellus työpöytäsovellukseksi, joka toimii Linux-järjestelmässä. Tutkimuksen aikana ei löydetty kelvollista komponenttia, jolla voidaan luoda graafinen käyttöliittymä .NET sovellukselle, joka tukisi Linuxia. Tämän perusteella luovuttiin työpöytäsovellusvaatimuksesta. Lopputuloksena on websovellus, jossa ASP .NET Corea ja Reactia käytettiin käyttöliittymän rakentamiseen. Tämän työn kautta osoitettiin, että webratkaisulla pystytään täyttämään sovelluksen käyttöliittymätarpeet

Effects of Enterovirus Infection on Innate Immunity and Beta Cell Function in Human Islets of Langerhans

This thesis focuses on enteroviral effects on human pancreatic islets. Most knowledge of viral effects on host cells relies on studies of immortalized cell lines or animal models. The islets represent a fundamentally different and less well studied cellular host. Also, enterovirus has been implicated in the etiology of type 1 diabetes (T1D). We show that when enterovirus replicates in human islets it activates innate immunity genes and induces secretion of the chemokines MCP-1 and IP-10. An important difference in activation of innate immunity by replicating EV and synthetic dsRNA is suggested, since the chemokine secretion induced by EV infection but not by dsRNA is reduced by female sex hormone. We also demonstrate a direct antiviral effect of nicotinamide, and even though this substance failed to prevent T1D in a large-scale study, this finding could have implications for the treatment/prevention of virus- and/or immune-mediated disease. We also had access to human pancreata from two organ donors with recent onset T1D and several donors with T1D-related autoantibodies, which gave us the opportunity to study ongoing pathogenic processes at and before the onset of T1D. Despite this, we could neither confirm nor reject the hypothesis that EV is involved in T1D development. Several observations, such as ultrastructural remodeling of the beta cell, activation of innate immunity, and immunopositivity to EV capsid protein 1, supported an ongoing virus infection, but direct evidence is still lacking. An interesting finding in the donors with recent onset T1D was that the islets were positively stained for insulin, but did not secrete insulin in response to glucose-stimulation. A similar effect was observed in EV-infected islets in vitro; EV destroyed islet function and insulin gene expression, but the islets still stained positive for insulin. This may be indicative of that a functional block in addition to beta cell destruction is involved in T1D pathogenesis. In conclusion, these studies of EV in isolated human islets in vitro support that this virus can cause T1D in vivo, but future studies will have to show if and how frequently this happens.

Effects of Enterovirus Infection on Innate Immunity and Beta Cell Function in Human Islets of Langerhans

This thesis focuses on enteroviral effects on human pancreatic islets. Most knowledge of viral effects on host cells relies on studies of immortalized cell lines or animal models. The islets represent a fundamentally different and less well studied cellular host. Also, enterovirus has been implicated in the etiology of type 1 diabetes (T1D). We show that when enterovirus replicates in human islets it activates innate immunity genes and induces secretion of the chemokines MCP-1 and IP-10. An important difference in activation of innate immunity by replicating EV and synthetic dsRNA is suggested, since the chemokine secretion induced by EV infection but not by dsRNA is reduced by female sex hormone. We also demonstrate a direct antiviral effect of nicotinamide, and even though this substance failed to prevent T1D in a large-scale study, this finding could have implications for the treatment/prevention of virus- and/or immune-mediated disease. We also had access to human pancreata from two organ donors with recent onset T1D and several donors with T1D-related autoantibodies, which gave us the opportunity to study ongoing pathogenic processes at and before the onset of T1D. Despite this, we could neither confirm nor reject the hypothesis that EV is involved in T1D development. Several observations, such as ultrastructural remodeling of the beta cell, activation of innate immunity, and immunopositivity to EV capsid protein 1, supported an ongoing virus infection, but direct evidence is still lacking. An interesting finding in the donors with recent onset T1D was that the islets were positively stained for insulin, but did not secrete insulin in response to glucose-stimulation. A similar effect was observed in EV-infected islets in vitro; EV destroyed islet function and insulin gene expression, but the islets still stained positive for insulin. This may be indicative of that a functional block in addition to beta cell destruction is involved in T1D pathogenesis. In conclusion, these studies of EV in isolated human islets in vitro support that this virus can cause T1D in vivo, but future studies will have to show if and how frequently this happens.

On the dynamics of the human endocrine pancreas and potential consequences for the development of type 1 diabetes

Little is known about the human islet life span, and beta-cell neogenesis is generally considered rare in adults. However, based on available data on beta-cell proliferation, calculations can be made suggesting that the dynamics of the endocrine pancreas is considerable even during adulthood, with islet neogenesis and a sustained increase in size of already formed islets. Islet-associated hemorrhages, frequently observed in most mammals including humans, could account for a considerable loss of islet parenchyma balancing the constant beta-cell proliferation. Notably, in subjects with type 1 diabetes, periductal accumulation of leukocytes and fibrosis is frequently observed, findings that are likely to negatively affect islet neogenesis from endocrine progenitor cells present in the periductal area. Impaired neogenesis would disrupt the balance, result in loss of islet mass, and eventually lead to beta-cell deficiency and compromised glucose metabolism, with increased islet workload and blood perfusion of remaining islets. These changes would impose initiation of a vicious circle further increasing the frequency of vascular events and hemorrhages within remaining islets until the patient eventually loses all beta-cells and becomes c-peptide negative

Characterization of host defense molecules in the human pancreas

The gut microbiota can play a role in pancreatitis and, likely, in the development of type 1 diabetes (T1D). Anti-microbial peptides and secretory proteins are important mediators of the innate immune response against bacteria but their expression in the human pancreas is not fully known. In this study, immunohistochemistry was used to analyze the expression of seven anti-microbial peptides (Defensin alpha 1, alpha 4, beta 1-4 and Cathelicidin) and two secretory proteins with known antimicrobial properties (REG3A and GP2) in pancreatic and duodenal biopsies from 10 non-diabetic organ donors and one organ donor that died at onset of T1D. Immunohistochemical data was compared with previously published whole-transcriptome data sets. Seven (Defensin alpha 1, beta 2, beta 3, alpha 4, GP2, Cathelicidin, and REG3A) host defense molecules showed positive staining patterns in most non-diabetic organ donors, whereas two (Defensin beta 1 and beta 4) were negative in all non-diabetic donors. Two molecules (Defensin alpha 1 and GP2) were restricted to the exocrine pancreas whereas two (Defensin beta 3, alpha 4) were only expressed in islet tissue. Cathelicidin, beta 2, and REG3A were expressed in both islets and exocrine tissue. The donor that died at onset of T1D had generally less positivity for the host defense molecules, but, notably, this pancreas was the only one where defensin beta 1 was found. Neither donor age, immune-cell infiltration, nor duodenal expression correlated to the pancreatic expression of host defense molecules. In conclusion, these findings could have important implications for the inflammatory processes in diabetes and pancreatitis as we find several host defense molecules expressed by the pancreatic tissue