Exploring and redefining Autoimmune polyendocrine syndrome type 1

Autoimmune polyendocrine syndrome type 1 (APS-1) is a rare, monogenic, childhood-onset disorder caused by mutations in the autoimmune regulator (AIRE) gene. Multi-organ autoimmune disease and chronic mucocutaneous candidiasis (CMC) dominate the clinical phenotype, making it an important model disease for autoimmunity. The objective of this thesis was to perform a detailed clinical, genetic and immunological characterisation of Norwegian APS-1 patients and explore the mechanisms behind CMC susceptibility. Fifty-two patients were included, revealing highly variable phenotypes. Most patients presented with one of the major disease components during childhood, hypoparathyroidism, primary adrenal insufficiency or CMC; enamel hypoplasia, hypoparathyroidism and CMC were the most frequent features. The prevalence of CMC indicates a specific immunodeficiency, which was underpinned by our finding of dysregulated immune responses to a Candida challenge. Specifically, monocytes produced significantly less interleukin-23p19 (IL), an important mediator in the Candida defence. Properly treatment of Candida infections is important as long-term inflammation in the oral cavity contributes to the development of oral malignancies, described here as a novel entity of APS-1. All Norwegian patients presented tissue-specific autoantibodies, and most had reactivity against IL-17, IL-22, and interferon-ω. The most common AIRE mutation was c.967_979del13. The splice mutation c.879+1G>A was associated with a mild adult-onset phenotype. Possible explanations are partial activity by AIRE lacking exon 7 and/or a certain amount of wild-type transcripts being produced despite mutation in a conserved splice donor site. Finally, the influence of environmental factors was explored by characterizing the oral microbiome. Indeed, APS-1 patients have significantly altered oral microbiota, with a general reduction in the total number of bacterial genera and species and altered relative abundance of major phyli compared to healthy subjects. This research has implications for the diagnosis and clinical care of patients with APS-1 and organ-specific autoimmune diseases and offers further insight into some of the mechanisms underlying autoimmune disorders and CMC

CREB is a critical regulator of normal hematopoiesis and leukemogenesis

The cAMP-responsive element binding protein (CREB) is a 43-kDa nuclear transcription factor that regulates cell growth, memory, and glucose homeostasis. We showed previously that CREB is amplified in myeloid leukemia blasts and expressed at higher levels in leukemia stem cells from patients with myeloid leukemia. CREB transgenic mice develop myeloproliferative disease after 1 year, but not leukemia, suggesting that CREB contributes to but is not sufficient for leukemogenesis. Here, we show that CREB is most highly expressed in lineage negative hematopoietic stem cells (HSCs). To understand the role of CREB in hematopoietic progenitors and leukemia cells, we examined the effects of RNA interference (RNAi) to knock down CREB expression in vitro and in vivo. Transduction of primary HSCs or myeloid leukemia cells with lentiviral CREB shRNAs resulted in decreased proliferation of stem cells, cell- cycle abnormalities, and inhibition of CREB transcription. Mice that received transplants of bone marrow transduced with CREB shRNA had decreased committed progenitors compared with control mice. Mice injected with Ba/F3 cells expressing either Bcr-Abl wild-type or T315I mutation with CREB shRNA had delayed leukemic infiltration by bioluminescence imaging and prolonged median survival. Our results suggest that CREB is critical for normal myelopoiesis and leukemia cell proliferation

Pubertal development in Norwegian girls

Background: Evidence suggests that girls worldwide are experiencing a decrease in age at pubertal onset, but data from Norwegian girls have not been available. Early pubertal timing is associated with adverse health outcomes. Pubertal breast development is currently categorized using the Tanner B scale and relies on visual inspection and/or palpation. Breast ultrasound appears to be a good alternative to this Tanner B assessment because it can separate adipose tissue from breast tissue and facilitates both staging and volumetric measurements. Objectives: The objectives were to explore ultrasound as an alternative method to assess breast development throughout puberty, to investigate the timing of puberty in Norwegian girls and construct pubertal references, and to shed light on the relationship between anthropometric indicators of body composition and the timing of puberty. Methods: This thesis is based on data from the Bergen Growth Study 1 (BGS1; 2003–2006, n = 1485, aged 8–15.5 years) and the Bergen Growth Study 2 (BGS2; 2016 and 2017, n = 703, aged 6–16 years). Data on menarche were recorded in both studies, while breast development was assessed only in the BGS2. Six distinct ultrasound-based breast stages were described, and the performance of these were evaluated in terms of observer agreement and in relation to the standardized Tanner B scale. Descriptive pubertal references were estimated from the BGS2. The associations between indirect (body mass index, BMI) and direct (skinfolds and waist circumference (WC)) measurements of fat with the timing of menarche were explored based on data from the BGS1. The ages at menarche between the studies were compared. Results: The ultrasound staging system performed well in terms of the agreement between one and two observers; however, direct measurements of size and volume lacked the necessary precision. When comparing ultrasound staging and Tanner B staging, an overall good agreement was found. A modest decline in the age at menarche was observed during the last decade, although pubertal references suggest that pubertal timing in Norway is similar to that of neighbouring countries. After adjustment for age and sex, both high and low levels of BMI, WC, subscapular skinfold (SSF) and triceps skinfold were all associated with an earlier and later menarche. In a fully adjusted analysis of all the measurements together, only a high BMI was related to earlier menarche, while a low BMI and a low SSF were associated with later menarche. Conclusions: Ultrasound is a feasible method to determine the breast developmental stage. This research has clinical implications for the evaluation of puberty in paediatric and adolescent female patients in Norway by providing descriptive references based on a healthy sample of girls. The decline in age at menarche was not explained by BMI and therefore warrants further investigations in population-based studies. BMI was the strongest anthropometric predictor of early and late menarche

Joint description of waves and currents applied in a simplified load case

In order to perform a more accurate analysis of marine structures, joint probability distributions of different metocean parameters have received an increasing interest during the last decade, facilitated by improved availability of reliable joint metocean data. There seems to be no general consensus with regard to the approach of estimating joint probability distributions of metocean parameters and a general overview of recent studies exploring different joint models for metocean parameters is presented. The main objective of this article is twofold: first to establish a joint distribution of significant wave height and current speed and then to assess the possible conservatism in the Norwegian design standard by applying this joint distribution in a simplified load case. Based on NORA10 wave data and simulated current data, a joint model for significant wave height and current speed at one location in the northern North Sea is presented. Since episodes of wind-generated inertial oscillations are governing the current conditions at this location, a joint conditional model with current speed conditional on significant wave height is suggested. A peak-over-threshold approach is selected. The significant wave height is found to be very well modelled by a 2-parameter Weibull distribution for significant wave height exceeding 8 m, while a log-normal distribution describes the current speed well. This model is used to Monte-Carlo simulate joint significant wave heights and current speeds for periods corresponding to the ultimate and accidental limit states (ULS and ALS), i.e. 100 and 10 000 years. The possible conservatism in the Norwegian design standard is assessed by a simplified case study. The results give a clear indication that the Norwegian design standard in not necessarily conservative, neither at ULS nor ALS level.acceptedVersio

Hematopoiesis, Inflammation and Aging—The Biological Background and Clinical Impact of Anemia and Increased C‐Reactive Protein Levels on Elderly Individuals

Anemia and systemic signs of inflammation are common in elderly individuals and are associated with decreased survival. The common biological context for these two states is then the hallmarks of aging, i.e., genomic instability, telomere shortening, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion and altered intercellular communication. Such aging-associated alterations of hematopoietic stem cells are probably caused by complex mechanisms and depend on both the aging of hematopoietic (stem) cells and on the supporting stromal cells. The function of inflammatory or immunocompetent cells is also altered by aging. The intracellular signaling initiated by soluble proinflammatory mediators (e.g., IL1, IL6 and TNFα) is altered during aging and contributes to the development of both the inhibition of erythropoiesis with anemia as well as to the development of the acute-phase reaction as a systemic sign of inflammation with increased CRP levels. Both anemia and increased CRP levels are associated with decreased overall survival and increased cardiovascular mortality. The handling of elderly patients with inflammation and/or anemia should in our opinion be individualized; all of them should have a limited evaluation with regard to the cause of the abnormalities, but the extent of additional and especially invasive diagnostic evaluation should be based on an overall clinical evaluation and the possible therapeutic consequences.publishedVersio

Toll-like Receptor 4, Osteoblasts and Leukemogenesis; the Lesson from Acute Myeloid Leukemia

Toll-like receptor 4 (TLR4) is a pattern-recognizing receptor that can bind exogenous and endogenous ligands. It is expressed by acute myeloid leukemia (AML) cells, several bone marrow stromal cells, and nonleukemic cells involved in inflammation. TLR4 can bind a wide range of endogenous ligands that are present in the bone marrow microenvironment. Furthermore, the TLR4-expressing nonleukemic bone marrow cells include various mesenchymal cells, endothelial cells, differentiated myeloid cells, and inflammatory/immunocompetent cells. Osteoblasts are important stem cell supporting cells localized to the stem cell niches, and they support the proliferation and survival of primary AML cells. These supporting effects are mediated by the bidirectional crosstalk between AML cells and supportive osteoblasts through the local cytokine network. Finally, TLR4 is also important for the defense against complicating infections in neutropenic patients, and it seems to be involved in the regulation of inflammatory and immunological reactions in patients treated with allogeneic stem cell transplantation. Thus, TLR4 has direct effects on primary AML cells, and it has indirect effects on the leukemic cells through modulation of their supporting neighboring bone marrow stromal cells (i.e., modulation of stem cell niches, regulation of angiogenesis). Furthermore, in allotransplant recipients TLR4 can modulate inflammatory and potentially antileukemic immune reactivity. The use of TLR4 targeting as an antileukemic treatment will therefore depend both on the biology of the AML cells, the biological context of the AML cells, aging effects reflected both in the AML and the stromal cells and the additional antileukemic treatment combined with HSP90 inhibition.publishedVersio

Simulated wind-generated inertial oscillations compared to current measurements in the northern North Sea

This is a pre-print of an article published in Ocean Dynamics. The final authenticated version is available online at: https://doi.org/10.1007/s10236-018-1150-zMeasured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerably accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and also the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves and currents for design of offshore structures will be presented in a separate paper.submittedVersio

Patients with bacterial sepsis are heterogeneous with regard to their systemic lipidomic profiles

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. In the present study, we investigated the systemic/serum lipidomic profile at the time of hospital admission for patients with bacterial sepsis. The study included 60 patients; 35 patients fulfilled the most recent 2016 Sepsis-3 criteria (referred to as Sepsis-3) whereas the remaining 25 patients had sepsis only according to the previous Sepsis-2 definition and could be classified as having Systemic Inflammatory Response Syndrome (SIRS). A total of 966 lipid metabolites were identified. Patients fulfilling the Sepsis-3 criteria differed from the Sepsis-2 patients with regard to only 15 lipid metabolites, and especially sphingolipids metabolism differed between these patient subsets. A total of only 43 metabolites differed between patients with and without bacteremia, including 12 lysophosphatidylcholines and 18 triacylglycerols (15 C18/C20 fatty acid metabolites decreased and three C14 myristate acid metabolites that were increased in bacteremia). Unsupervised hierarchical clustering analyses based on the identified sphingolipids, phosphatidylcholine and triacylglycerols showed that (i) the majority of Sepsis-3 patients differed from SIRS patients especially with regard to lysophosphatidylcholine levels; (ii) the minority of Sepsis-3 patients that clustered together with the majority of SIRS patients showed lower Sequential Organ Failure Assessment (SOFA) scores than the other Sepsis-3 patients; and (iii) the variation between the patients in the identified/altered sphingolipid and triacylglycerol metabolites further increased the heterogeneity of Sepsis-3 patients with regard to their systemic lipidomic profile at the time of diagnosis. To conclude, patients fulfilling the Sepsis-3 criteria differ with regard to their metabolic profile, and this variation depends on disease severity.publishedVersio

Mesenchymal stem cells support survival and proliferation of primary human acute myeloid leukemia cells through heterogeneous molecular mechanisms

Acute myeloid leukemia (AML) is a bone marrow malignancy, and various bone marrow stromal cells seem to support leukemogenesis, including osteoblasts and endothelial cells. We have investigated how normal bone marrow mesenchymal stem cells (MSCs) support the in vitro proliferation of primary human AML cells. Both MSCs and primary AML cells show constitutive release of several soluble mediators, and the mediator repertoires of the two cell types are partly overlapping. The two cell populations were cocultured on transwell plates, and MSC effects on AML cells mediated through the local cytokine/soluble mediator network could thus be evaluated. The presence of normal MSCs had an antiapoptotic and growth-enhancing effect on primary human AML cells when investigating a group of 51 unselected AML patients; this was associated with increased phosphorylation of mTOR and its downstream targets, and the effect was independent of cytogenetic or molecular-genetic abnormalities. The MSCs also supported the long-term proliferation of the AML cells. A subset of the patients also showed an altered cytokine network with supra-additive levels for several cytokines. The presence of cytokine-neutralizing antibodies or receptor inhibitors demonstrated that AML cells derived from different patients were heterogeneous with regard to effects of various cytokines on AML cell proliferation or regulation of apoptosis. We conclude that even though the effects of single cytokines derived from bone marrow MSCs on human AML cells differ among patients, the final cytokine-mediated effects of the MSCs during coculture is growth enhancement and inhibition of apoptosis.publishedVersio