| 1. |
- Dias, P. Joana, et al.
(författare)
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Establishment of a taxonomic and molecular reference collection to support the identification of species regulated by the Western Australian Prevention List for Introduced Marine Pests
- 2017
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Ingår i: Management of Biological Invasions. - : Regional Euro-Asian Biological Invasions Centre Oy (REABIC). - 1989-8649. ; 8:2, s. 215-225
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Tidskriftsartikel (refereegranskat)abstract
- Introduced Marine Pests (IMP, = non-indigenous marine species) prevention, early detection and risk-based management strategies have become the priority for biosecurity operations worldwide, in recognition of the fact that, once established, the effective management of marine pests can rapidly become cost prohibitive or impractical. In Western Australia (WA), biosecurity management is guided by the Western Australian Prevention List for Introduced Marine Pests which is a policy tool that details species or genera as being of high risk to the region. This list forms the basis of management efforts to prevent introduction of these species, monitoring efforts to detect them at an early stage, and rapid response should they be detected. It is therefore essential that the species listed can be rapid and confidently identified and discriminated from native species by a range of government and industry stakeholders. Recognising that identification of these species requires very specialist expertise which may be in short supply and not readily accessible in a regulatory environment, and the fact that much publicly available data is not verifiable or suitable for regulatory enforcement, the WA government commissioned the current project to collate a reference collection of these marine pest specimens. In this work, we thus established collaboration with researchers worldwide in order to source representative specimens of the species listed. Our main objective was to build a reference collection of taxonomically vouchered specimens and subsequently to generate species-specific DNA barcodes suited to supporting their future identification. To date, we were able to obtain specimens of 75 species (representative of all but four of the pests listed) which have been identified by experts and placed with the WA Government Department of Fisheries and, where possible, in accessible museums and institutions in Australasia. The reference collection supports the fast and reliable taxonomic and molecular identification of marine pests in WA and constitutes a valuable resource for training of stakeholders with interest in IMP recognition in Australia. The reference collection is also useful in supporting the development of a variety of DNA-based detection strategies such as real-time PCR and metabarcoding of complex environmental samples (e.g. biofouling communities). The Prevention List is under regular review to ensure its continued relevance and that it remains evidence and risk-based. Similarly, its associated reference collection also remains to some extent a work in progress. In recognition of this fact, this report seeks to provide details of this continually evolving information repository publicly available to the biosecurity management community worldwide.
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| 2. |
- Edlund, Anna, et al.
(författare)
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Defective exocytosis and processing of insulin in a cystic fibrosis mouse model
- 2019
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Ingår i: Journal of Endocrinology. - 1479-6805. ; 241:1, s. 45-57
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Tidskriftsartikel (refereegranskat)abstract
- Cystic fibrosis-related diabetes (CFRD) is a common complication for patients with cystic fibrosis (CF), a disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). The cause of CFRD is unclear, but a commonly observed reduction in first-phase insulin secretion suggests defects at the beta cell level. Here we aimed to examine beta- and alpha-cell function in the Cftrtm1EUR/F508del mouse model (C57BL/6J), which carries the most common human mutation in CFTR, the F508del mutation. CFTR expression, beta cell mass, insulin granule distribution, hormone secretion and single cell capacitance changes were evaluated using islets (or beta cells) from F508del mice and age-matched wild-type mice aged 7-10 weeks. Granular pH was measured with DND-189 fluorescence. Serum glucose, insulin and glucagon levels were measured in vivo, and glucose tolerance was assessed using IPGTT. We show increased secretion of proinsulin and concomitant reduced secretion of C-peptide in islets from F508del mice compared to WT mice. Exocytosis and number of docked granules was reduced. We confirmed reduced granular pH by CFTR stimulation. We detected decreased pancreatic beta cell area, but unchanged beta cell number. Moreover, the F508del mutation caused failure to suppress glucagon secretion leading to hyperglucagonemia. In conclusion, F508del mice have beta cell defects resulting in 1) reduced number of docked insulin granules and reduced exocytosis, and 2) potential defective proinsulin cleavage and secretion of immature insulin. These observations provide insight into the functional role of CFTR in pancreatic islets and contribute to increased understanding of the pathogenesis of CFRD.
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| 3. |
- Huhn, Evelyn Annegret, et al.
(författare)
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Effectiveness of real-time continuous glucose monitoring to improve glycaemic control and pregnancy outcome in patients with gestational diabetes mellitus : a study protocol for a randomised controlled trial
- 2020
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Real-time continuous glucose monitoring (rt-CGM) informs users about current interstitial glucose levels and allows early detection of glycaemic excursions and timely adaptation by behavioural change or pharmacological intervention. Randomised controlled studies adequately powered to evaluate the impact of long-term application of rt-CGM systems on the reduction of adverse obstetric outcomes in women with gestational diabetes (GDM) are missing. We aim to assess differences in the proportion of large for gestational age newborns in women using rt-CGM as compared with women with self-monitored blood glucose (primary outcome). Rates of neonatal hypoglycaemia, caesarean section and shoulder dystocia are secondary outcomes. A comparison of glucose metabolism and quality of life during and after pregnancy completes the scope of this study.METHODS AND ANALYSIS: Open-label multicentre randomised controlled trial with two parallel groups including 372 female patients with a recent diagnosis of GDM (between 24+0 until 31+6 weeks of gestation): 186 with rt-CGM (Dexcom G6) and 186 with self-monitored blood glucose (SMBG). Women with GDM will be consecutively recruited and randomised to rt-CGM or control (SMBG) group after a run-in period of 6-8 days. The third visit will be scheduled 8-10 days later and then every 2 weeks. At every visit, glucose measurements will be evaluated and all patients will be treated according to the standard care. The control group will receive a blinded CGM for 10 days between the second and third visit and between week 36+0 and 38+6. Cord blood will be sampled immediately after delivery. 48 hours after delivery neonatal biometry and maternal glycosylated haemoglobin A1c (HbA1c) will be assessed, and between weeks 8 and 16 after delivery all patients receive a re-examination of glucose metabolism including blinded CGM for 8-10 days.ETHICS AND DISSEMINATION: This study received ethical approval from the main ethic committee in Vienna. Data will be presented at international conferences and published in peer-reviewed journals.TRIAL REGISTRATION NUMBER: NCT03981328; Pre-results.
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| 4. |
- Hühn, Michael
(författare)
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Host-microbe interactions in coxsackievirus infection : focus on innate immunity
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Coxsackievirus group B (CVB) is a common virus that usually causes only mild symptoms in humans. However, occasionally these infections result in severe diseases like meningitis, myocarditis and pancreatitis. In addition, CVB infections have been suggested to be involved in the etiology of chronic diseases such as dilated cardiomyopathy and type 1 diabetes (T1D). Why the outcome of a CVB infection can vary so greatly is not entirely clear. Besides virusintrinsic factors it has been hypothesized that the ability to mount an adequate immune response is important in regulating damage after CVB infection. The innate immune response is essential for the control of virus replication early after infection and for initiating the adaptive immune response, which is needed to clear the infection. If the host fails to initiate a suitable immune response, damage may arise as a result of uncontrolled virus replication or excessive inflammation. The aim of this thesis was to increase our understanding of how the innate immune response is initiated after CVB infections and how it may help to control the virus. In paper I, we showed that the intracellular virus sensor melanoma differentiationdifferentiation protein-5 (MDA-5) plays an important role in the immune response to CVB. Lack of MDA-5 weakened the host s ability to limit virus replication during the first days after infection, which lead to increased tissue damage. In addition, we found that the genetic background determines how heavily the host relies on MDA-5 for survival. Mice lacking MDA-5 on a C57/BL6 background rapidly succumbed to CVB infection while 129/SvJ mice survived and eventually cleared the virus even in the absence of MDA-5. Surprisingly, production of type I interferons (IFNs) was not significantly compromised by a lack of MDA-5. Type I IFNs produced by infected cells can stimulate immune cells like natural killer (NK) cells that have been demonstrated to be important in the host response to CVB infections. In paper II, we established that CVB infection modulates the cell surface expression of NK cell receptor ligands. The downregulation of inhibitory class I HLA alleles and the activating NKG2D ligand MICA did not result in increased NK cell mediated killing of the infected cells. However, after encountering infected cells, NK cells responded with enhanced secretion of IFN-gamma, a cytokine with well-described antiviral and immuno-modulatory properties. Type I and II IFNs secreted by infected cells and/or immune cells are an indispensable part of the immune response to virus infections. In paper III, it was demonstrated that human pancreatic islet cells respond to IFN stimulation by upregulating the expression of genes involved in virus recognition, limiting virus replication and shaping of the adaptive immune response. This so-called antiviral state reduced the permissiveness of human islet cells to CVB infection. Patients suffering from cystic fibrosis (CF) have a well-described defect in their antimicrobial immune response, leaving them especially vulnerable to respiratory tract infections. Using a mouse model for CF in paper IV, it was shown that a defective cystic fibrosis transmembrane conductance regulator (cftr) gene, the genetic cause for CF, renders mice susceptible to systemic CVB infection. Mice lacking CFTR succumbed to CVB at a dose that was not lethal for their wild type counterparts. In conclusion, the studies included in this thesis add to our understanding of how the innate immune response recognizes and responds to CVB infections. Interestingly, MDA-5, NK cells and IFNs, while important in the immune response to CVB, have also been implicated to play a role in the development of T1D. This supports the notion that the immune response mounted by the host may influence the outcome of an infection with CVB. Hopefully, a better understanding of the host immune response can help to prevent the severe outcomes sometimes associated with CVB infection.
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| 5. |
- Huhn, Stefanie, et al.
(författare)
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Coding variants in NOD-like receptors : An association study on risk and survival of colorectal cancer
- 2018
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Nod-like receptors (NLRs) are important innate pattern recognition receptors and regulators of inflammation or play a role during development. We systematically analysed 41 non-synonymous single nucleotide polymorphisms (SNPs) in 21 NLR genes in a Czech discovery cohort of sporadic colorectal cancer (CRC) (1237 cases, 787 controls) for their association with CRC risk and survival. Five SNPs were found to be associated with CRC risk and eight with survival at 5% significance level. In a replication analysis using data of two large genome-wide association studies (GWASs) from Germany (DACHS: 1798 cases and 1810 controls) and Scotland (2210 cases and 9350 controls) the associations found in the Czech discovery set were not confirmed. However, expression analysis in human gut-related tissues and immune cells revealed that the NLRs associated with CRC risk or survival in the discovery set were expressed in primary human colon or rectum cells, CRC tissue and/or cell lines, providing preliminary evidence for a potential involvement of NLRs in general in CRC development and/or progression. Most interesting was the finding that the enigmatic development-related NLRP5 (also known as MATER) was not expressed in normal colon tissue but in colon cancer tissue and cell lines. Future studies may show whether regulatory variants instead of coding variants might affect the expression of NLRs and contribute to CRC risk and survival.
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| 6. |
- Huhn, Stefanie, et al.
(författare)
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Shared ancestral susceptibility to colorectal cancer and other nutrition related diseases
- 2012
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Ingår i: BMC Medical Genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 13:94
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Tidskriftsartikel (refereegranskat)abstract
- Background: The majority of non-syndromic colorectal cancers (CRCs) can be described as a complex disease. A two-stage case-control study on CRC susceptibility was conducted to assess the influence of the ancestral alleles in the polymorphisms previously associated with nutrition-related complex diseases. Methods: In stage I, 28 single nucleotide polymorphisms (SNPs) were genotyped in a hospital-based Czech population (1025 CRC cases, 787 controls) using an allele-specific PCR-based genotyping system (KASPar (R)). In stage II, replication was carried out for the five SNPs with the lowest p values. The replication set consisted of 1798 CRC cases and 1810 controls from a population-based German study (DACHS). Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between genotypes and CRC risk were estimated using logistic regression. To identify signatures of selection, Fay-Wu's H and Integrated Haplotype Score (iHS) were estimated. Results: In the Czech population, carriers of the ancestral alleles of AGT rs699 and CYP3A7 rs10211 showed an increased risk of CRC (OR 1.26 and 1.38, respectively; two-sided p <= 0.05), whereas carriers of the ancestral allele of ENPP1 rs1044498 had a decreased risk (OR 0.79; p <= 0.05). For rs1044498, the strongest association was detected in the Czech male subpopulation (OR 0.61; p=0.0015). The associations were not replicated in the German population. Signatures of selection were found for all three analyzed genes. Conclusions: Our study showed evidence of association for the ancestral alleles of polymorphisms in AGT and CYP3A7 and for the derived allele of a polymorphism in ENPP1 with an increased risk of CRC in Czechs, but not in Germans. The ancestral alleles of these SNPs have previously been associated with nutrition-related diseases hypertension (AGT and CYP3A7) and insulin resistance (ENPP1). Future studies may shed light on the complex genetic and environmental interactions between different types of nutrition-related diseases.
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| 7. |
- Hultcrantz, Monica, et al.
(författare)
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Interferons induce an antiviral state in human pancreatic islet cells
- 2007
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Ingår i: Virology. - : Elsevier BV. - 0042-6822 .- 1096-0341. ; 367:1, s. 92-101
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Tidskriftsartikel (refereegranskat)abstract
- Enterovirus infections, in particular those with Coxsackieviruses, have been linked to the development of type 1 diabetes (T1D). Although animal models have demonstrated that interferons (IFNs) regulate virus-induced T1D by acting directly on the beta cell, little is known on the human pancreatic islet response to IFNs. Here we show that human islet cells respond to IFNs by expressing signature genes of antiviral defense. We also demonstrate that they express three intracellular sensors for viral RNA, the toll like receptor 3 (TLR3) gene, the retinoic acid-inducible gene I (RIG-I) and the melanoma differentiation-associated gene-5 (MDA-5), which induce type I IFN production in infected cells. Finally, we show for the first time that the IFN-induced antiviral state provides human islets with a powerful protection from the replication of Coxsackievirus. This may be critical for beta cell survival and protection from virus-induced T1D in humans.
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| 8. |
- Johansson, Gustav, et al.
(författare)
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Ultrasensitive DNA Immune Repertoire Sequencing Using Unique Molecular Identifiers.
- 2020
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Ingår i: Clinical chemistry. - : Oxford University Press (OUP). - 1530-8561 .- 0009-9147. ; 66:9, s. 1228-1237
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Tidskriftsartikel (refereegranskat)abstract
- Immune repertoire sequencing of the T-cell receptor can identify clonotypes that have expanded as a result of antigen recognition or hematological malignancies. However, current sequencing protocols display limitations with nonuniform amplification and polymerase-induced errors during sequencing. Here, we developed a sequencing method that overcame these issues and applied it to γδ T cells, a cell type that plays a unique role in immunity, autoimmunity, homeostasis of intestine, skin, adipose tissue, and cancer biology.The ultrasensitive immune repertoire sequencing method used PCR-introduced unique molecular identifiers. We constructed a 32-panel assay that captured the full diversity of the recombined T-cell receptor delta loci in γδ T cells. The protocol was validated on synthetic reference molecules and blood samples of healthy individuals.The 32-panel assay displayed wide dynamic range, high reproducibility, and analytical sensitivity with single-nucleotide resolution. The method corrected for sequencing-depended quantification bias and polymerase-induced errors and could be applied to both enriched and nonenriched cells. Healthy donors displayed oligoclonal expansion of γδ T cells and similar frequencies of clonotypes were detected in both enrichment and nonenriched samples.Ultrasensitive immune repertoire sequencing strategy enables quantification of individual and specific clonotypes in a background that can be applied to clinical as well as basic application areas. Our approach is simple, flexible, and can easily be implemented in any molecular laboratory.
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| 9. |
- Ohlsson, Lena, et al.
(författare)
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Expression of intestinal and lung alkaline sphingomyelinase and neutral ceramidase in cystic fibrosis f508del transgenic mice.
- 2008
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - Jpgn. - 1536-4801. ; 47:5, s. 547-554
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The intestinal brush border enzymes alkaline sphingomyelinase (alk-SMase) and neutral ceramidase (CDase) digest milk sphingomyelin in suckling neonates. In addition, alk-SMase, CDase, and acid sphingomyelinase (acid-SMase) have been implicated in sphingolipid signaling, which exhibits abnormalities in cystic fibrosis (CF). In this study, we tested the hypothesis that the expression of these enzymes is different in CF. MATERIALS AND METHODS: We used mice with F508del (Cftr) mutation, a CF mouse model with well-characterized intestinal pathology. Enzyme activities were measured using radiolabeled sphingolipid substrates incubated with tissue homogenates from different organs and intestinal contents of wild-type mice, homozygous, and heterozygous F508del mice. RESULTS: No difference was found in levels of CDase and alk-SMase in the small intestinal mucosa or in their longitudinal distribution. Acid-SMase activity was significantly lower in the mucosa of the distal half of the small intestine of F508del compared with wild-type mice. Despite a lower body weight of F508del mice, length and weight of the small intestine and weight per centimeter of colon were larger than in wild-type. Neutral CDase and alk-SMase activities in lungs were lower than in the gut, whereas acid-SMase activity was comparable in both organs. CDase activity in the spleen was significantly higher in F508del than in wild-type mice. CONCLUSIONS: Alk-SMase and neutral CDase are normally expressed in F508del CF mice, whereas activity of acid-SMase in the distal small intestine is decreased. We found no differences in activity of these enzymes in lungs in this mouse model.
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