La neurofibromatose de type 1 (NF1) représente la maladie génétique autosomale dominante la plus fréquente en France, après la mucovisidose, avec une incidence de 1 individu sur 3500. Il s'agit d'une pathologie multi-systémique présentant un tableau clinique varié. Parmi la pléthore de symptôme, sont comptées des manifestations neurocutanées telles que les taches « café-au-lait » (zone d'hyperpigmentation localisée) et les neurofibromes (tumeurs bénignes de la gaine périphérique de la myéline) mais également des défauts osseux et des troubles cognitifs. La pénétrance de NF1 est complète mais la manifestation et la sévérité des symptômes peuvent varier d'un individu à l'autre. Le gène NF1 responsable de la maladie, localisé sur le chromosome 17, est un gène suppresseur de tumeur qui code pour la neurofibromine. Dans le but de développer un modèle cellulaire humain pertinent pour l'étude des défauts osseux associés à NF1, nous avons utilisé des cellules souches induites à la pluripotence porteuse de la mutation causale NF1 (hiPS-NF1). Dans ces travaux, nous avons montré qu'une perte d'expression de la neurofibromine dans les ostéoblastes dérivés de hiPS-NF1 reproduisait le phénotype d'ostéogénèse réduite et qu'il était possible d'améliorer la capacité des hiPS-NF1 à se différencier en ostéoblaste à l'aide de molécules pharmacologiques. Toujours dans le but de proposer un modèle cellulaire humain le plus relevant possible, nous avons développé des lignées isogéniques avec la technologie CRISPR/Cas 9 afin d'étudier l'impact d'une perte partielle ou totale de l'expression de la neurofibromine sur le phénotype osseux. En parallèle, afin de pouvoir étudier un autre phénotype associé à NF1, un protocole de différenciation de cellules de Schwann sous culture définie en utilisant des facteurs de croissance et des molécules de signalisation, a partir des hiPS a été développé. Des cellules de Schwann-like ont été obtenues en 30 jours en engagement la différenciation des cellules souches vers la crête neurale afin d'induire l'émergence de précurseurs de cellules de Schwann par l'action de molécules telles que le récepteur de type I du TGF-ß (SB431542), l'hereguline ß1, l'IGF1, le FGF2 et un activateur de WNT3a (CHIR99021). L'analyse par q-PCR montre une augmentation des marqueurs de différents stades de différenciation de la cellule de Schwann : crête neurale (SOX10, ERBB3), cellules de Schwann précurseurs (MPZ, CAD19) et cellules de Schwann immatures (S100) au bout de 30 jours de différenciation. Ces résultats ont été complétés par l'analyse protéique des cellules différenciées et par la mise en co-culture de ces cellules avec des motoneurones différenciés à partir d'hiPS. L'ensemble de ce travail a permis de valider la pertinence de l'utilisation des cellules souches pluripotentes porteuses de mutation dans la modélisation de pathologie génétique. Permettant à plus long terme la recherche de molécules actives par des approches de de criblage pharmacologique ou par des approches de thérapie cellulaire. / Neurofibromatosis type 1 (NF1) is an autosomal genetic disease with an incidence of 1 in 3,500 individuals. This is a multi-systemic disorder with a plethora of various symptoms. Among with we find neurocutaneous manifestations such as "café-au-lait" spots (zone of localized hyperpigmentation) and neurofibromas (benign tumors of the peripheral sheath of myelin), but also bone defects and cognitive disorders. The penetrance of NF1 is complete but the manifestation and severity of symptoms may vary from one individual to another. The NF1 gene responsible for the disease, located on chromosome 17, is a tumor suppressor gene that encodes neurofibromin. In order to develop a relevant human cellular model for the study of bone defects associated with NF1, we used pluripotency-induced stem cells that carry the NF1 causal mutation (hiPS-NF1). In this work, we have shown that loss of neurofibromin expression in osteoblasts derived from hiPS-NF1 reproduces the reduced osteogenesis phenotype. We have also shown that pharmacological molecules can improve the ability of hiPS-NF1 to differentiate in osteoblast. In order to propose the most relevant human cell model, we have developed isogenic lines with CRISPR / Cas 9 technology to study the impact of a partial or total loss of neurofibromin on the bone phenotype. Simultaneously, a Schwann cells differentiation protocol from hiPS was developed under culture defined using growth factors and signaling molecules. Schwann-like cells were obtained in 30 days by the use of molecules such as the type I receptor TGF-β (SB431542), heregulin β1, IGF1, FGF2 and activator of WNT3a (CHIR99021). The q-PCR analysis shows an increase in Schwann cell markers: neural crest (SOX10, ERBB3), precursor Schwann cells (MPZ, CAD19) and immature Schwann cells (S100). These results were confirmed by protein analysis of the differentiated cells and by the co-culture analysis of these cells with differentiated motoneurons from hiPS. All of this work validated the relevance of pluripotent stem cells in the modeling of genetic pathology.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 5 uppsatser.

Bakgrund: Diabetes mellitus typ 1 är en autoimmun sjukdom och antalet som insjuknar ökar varje år. Under ungdomstiden sker mycket i människans kropp och det kan vara en utmaning att balansera blodsockernivåer när hormonerna i kroppen svajar. Ungdomar med diabetes mellitus typ 1 står därför inför stora utmaningar för att lyckas med sin behandling. Syfte: Syftet är att belysa ungdomars upplevelser av att leva med diabetes mellitus typ 1. Metod: Metoden är en litteraturstudie baserad på både kvalitiva och kvantitativa studier. Analysen är genomförd utifrån en modell av Axelsson (2012). Resultat: I resultatet framkom att ungdomarna med diabetes mellitus typ 1 växte in i rollen i att bli mer självständiga i sin behandling. Detta var inte alltid lätt. Ungdomarna påverkades av hur deras vänner bemötte diagnosen, hur de blev bemötta av vården samt hur villiga deras föräldrar var att lämna över ansvaret. Resultatet presenteras utifrån fyra huvudteman samt nio subteman. Diskussion:I diskussionen tar vi upp vikten av att jobba med målet att patienten ska få kunskap så att denne kan sköta sin behandling självständigt. Vikten av stöd för att motverka känslor av skam för sjukdomen och dess behandling belyses också.

Type 1A diabetes mellitus or T1D is a chronic disease characterized by T cell mediated destruction of the insulin producing β cells in the islets of Langerhans. The classical symptoms include high glucose levels in urine and blood, polyuria, and polydipsia. Complications associated with T1D include blindness, amputations, and end-stage renal disease, and premature death. The non-obese diabetic (NOD) mouse, first described in 1980, is widely used as a model organism for T1D. T1D disease in the NOD mouse shares a number of similarities to human T1D including dependence on genetic and environmental factors. More than 30 disease associated gene regions or loci (termed insulin dependent diabetes, or Idd, loci) have been associated with T1D development in NOD. For some of these Idds, the corresponding region in human has been linked to the development of T1D in human. T1D, both in humans and mice, is recognized as a T cell mediated disease. However, many studies have shown the importance of both the metabolome and the immune system in the pathogenesis of the disease. Appearance of autoantibodies in the serum of patients is the first sign of pathogenesis. However, molecular and cellular events precede the immune attack on the β-cell immunity. It has been shown that patients who developed T1D have an altered metabolome prior to the appearance of autoantibodies. Although much is known about the pathogenesis of T1D, the contribution of the environment/immune factors triggering the disease is still to be revealed.  In the present study both metabolic and immune deviations observed in the NOD mouse was analyzed. Serum metabolome analysis of the NOD mouse revealed striking resemblance to the human metabolic profile, with many metabolites in the TCA cycle significantly different from the non-diabetic control B6 mice. In addition, an increased level of glutamic acid was of the most distinguishing metabolite. A detailed bioinformatics analysis revealed various genes/enzymes to be present in the Idd regions. Compared to B6 mice, many of the genes correlated to the metabolic pathways, showed single nucleotide polymorphism (SNP), which can eventually affect the functionality of the protein. A genetic analysis of the increased glutamic acid revealed several Idd regions to be involved in this phenotype. The regions mapped in the genetic analysis harbor important enzymes and transporters related to glutamic acid. In-vitro islet culture with glutamic acid led to increased beta cell death indicating a toxic role of glutamic acid specifically towards insulin producing beta cells. In the analysis of the immune system, B cells from NOD mice, which are known to express high levels of TACI, were stimulated with APRIL, a TACI ligand. This resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. NOD mice have previously been shown to react vigorously to T-dependent antigens upon immunization. In this study we confirmed this as NOD mice showed an enhanced and prolonged immune response to hen egg lysozyme. Thus, serum IgG levels were significantly increased in the NOD mice and were predominantly of the IgG1 subtype. Immunofluorescence analysis revealed increased number of germinal centers in the NOD mice. Transfer of purified B and T cells from NOD to an immune deficient mouse could reproduce the original phenotype as seen in the NOD mice.     Collectively, this thesis has analyzed the metabolomics and immune deviations observed in the NOD mice.

Exposure to microorganisms is considered an environmental factor which can contribute to diabetes mellitus via cytotoxicity or autoimmune responses against pancreatic cells. Firstly, the effects on rat insulinoma pancreatic β-cell line of secondary metabolites pyrrolnitrin (Burkholderia spp), phenazine compounds (Pseudomonas aeruginosa and Burkholderia spp) were investigated. Both compounds separately showed significant cytotoxicity after 24 h and at concentrations of 10 & 100 ng/ml potentiated insulin gene transcription, Ca2+ content and glucose-stimulated insulin secretion (GSIS). Furthermore, the outward membrane current was inhibited by phenazine (100 ng/ml) or pyrrolnitrin (10 or 100 ng/ml). Secondly, the capacity of 45 microbial species to bind insulin was screened in order to assess how common insulin binding was amongst microorganisms Burkholderia multivorans, B. cenocepacia and Aeromonas salmonicida bound insulin. A genomic library of B. multivorans was constructed in λ Zap Express and screened successfully for insulin binding recombinants. Recombinant phagemids p1 & p2 were excised, p1, encoded an insulin binding protein (IBP1 30 kDa) with homology to the iron complex siderophore receptor. For p2, two IBPs were detected at 20 & 30 kDa (IBP2 & IBP3), representing an intracellular and outer membrane peptide transporter. Comparison of IBP1 and human insulin receptor (HIR) produced 6 linear epitopes, and for IBP2 & IBP3 produced 3 epitopes. Thirdly, glutamic acid decarboxylase GAD65 is a major pancreatic autoantigen contributing to autoimmune diabetes. To assess the likelihood that microorganisms possess epitopes that mimic regions on GAD, 45 microbial species were tested for homology. This was facilitated by purifying recombinant GAD protein which was used to produce GAD antiserum. Four E. coli cross-reacting proteins were identified using mass spectrometry, outer-membrane protein A, formate dehydrogenase, superoxide dismutase and DNA starvation protein. Epitopes occurred at the C-terminal region of GAD65 (residues 419–565), a region previously reported to be targeted by autoantibodies. This study suggests that pyrrolnitrin and phenazine are cytotoxic to pancreatic β-cells and B. multivorans IBPs linear epitopes may be diabetogenic, particularly in patients with cystic fibrosis related diabetes (CFRD) who suffer a long term infections with Pseudomonas and Burkholderia species. Furthermore, microbial GAD epitopes could potentially induce an autoimmune response leading to diabetes.

Introduction: Key studies have found an association between attachment style and poor diabetes outcomes in the adult diabetic populations. Specifically insecure attachment has been found to predict elevated glycated haemoglobin levels (HbA1c). Further studies have indicated that substance use and mental health difficulties also influence HbA1c. These factors have been looked at individually making it difficult to directly assess the overall effect of attachment on HbA1c and the potential mediating effects of substance use and mental health. The adolescent population has not been considered in studies examining these relationships. This study compares attachment security, level of substance use, interpersonal problems, anxiety and depression in relation to their role in blood glucose control in an adolescent population with Type 1 diabetes. Method: A quantitative, cross sectional, questionnaire design was employed to examine the role of the aforementioned factors in relation to HbA1c level. The target population included all patients aged 14 years to 18 years, inclusive, who attended for review at Diabetes Clinics across Lothian. Participants had a diagnosis of Type 1 Diabetes for at least one year and no additional diagnoses of mental health disorder or other chronic condition. At the clinic patients were approached and asked to complete a set of self report questionnaires. Measures of attachment were adapted versions of the Relationship Questionnaire (RQ) and the Relationship Scales Questionnaire (RSQ). Interpersonal problems were assessed using the short version of the Inventory of Interpersonal Problems (IIP-32). The Hospital Anxiety and Depression Scale (HADS) assessed levels of anxiety and depression. The Adolescent Substance Abuse Subtle Screening Inventory- A2 (SASSI-A2) was used to measure substance use. Blood glucose levels (HbA1c%) were obtained from clinic staff. A total of 88 participants returned completed questionnaires (response rate 79.3%). Results: When all correlations between predictors and HbA1c were examined, a negative correlation was found between attachment and HbA1c level. A positive correlation was found between anxiety and HbA1c level. Multiple regression analyses examined the relationship between attachment security and HbA1c before analysing additional predictors in the same model. No significant relationships emerged however the multiple regression model was not a significant fit for the data. Path Analysis considered all relationships between variables simultaneously while also providing information on how the model fits the data. Attachment security directly related to HbA1c levels when the contributions of gender, interpersonal problems and substance use were considered. Anxiety and depression did not predict HbA1c nor did they contribute to any other relationships with HbA1c. Interpersonal problems had a direct relationship with HbA1c when the contribution of substance use and attachment were considered. Conclusion: Attachment predicts HbA1c. The nature of this relationship is further understood when the contribution of additional psychological variables are considered. Methodological issues, clinical implications and directions for future research are discussed.

Glucocorticoids can reduce infarct size when given immediately after myocardial infarction (MI) but are detrimental when administration is continued into the post-infarct healing phase. A number of experimental studies have shown that reduction of infarct expansion by enhancing blood supply to the infarct border reduces remodelling and improves heart function post-MI. Previous experiments from this laboratory have shown that mice unable to locally regenerate corticosterone due to deficiency in 11β-hydroxysteroid dehydrogenase type 1 (11HSD1) have an enhanced angiogenic response during myocardial infarct healing that is associated with improved cardiac function. We hypothesized that the enhanced angiogenic response in 11HSD1 knock out (-/-) mice would be preceded by augmented inflammation. Moreover this would be associated with improved cardiac function. This thesis aimed firstly to establish that murine cardiac phenotype was not influenced by 11HSD1 deficiency. 11HSD1-/- and C57Bl6 control mice had comparable cardiac structure and function. 11HSD1 expression was localised to fibroblasts and vascular smooth muscle cells in the myocardium. The second aim of this thesis was to characterise the healing response after MI in 11HSD1-/- mice compared to C57Bl6 mice. Neutrophil infiltration peaked 2 days after MI and was significantly enhanced in the 11HSD1-/- mice relative to C57Bl6 mice, despite comparable infarct size in both groups. This was followed by increased macrophage accumulation in the infarct border. Furthermore, in the 11HSD1-/- mice a greater proportion of macrophages were of the alternatively activated phenotype. Left ventricular expression of pro-angiogenic IL-8, but not VEGF, was increased. Cellular proliferation and vessel density at 7 days were greater in 11HSD1-/- compared to C57Bl6 hearts. This was associated with improved cardiac function 7 days post-MI. The third aim of this thesis was to determine whether the enhancement in vessel density and cardiac function was maintained beyond the initial wound healing phase. 11HSD1-/- mice retained the increased vessel density compared to C57Bl6 mice and these vessels were smooth muscle coated suggesting vessel maturation. This was associated with sustained improvement in cardiac function and modification of the scar characteristics. The final aim of this thesis was to establish whether the effect of the knock out could be recapitulated by administration of a small molecule inhibitor of 11HSD1 after MI. Oral administration of the 11HSD1 inhibitor had no effect on inflammation, angiogenesis and heart function as determined at 7 days post-MI relative to vehicle treated animals. In conclusion, the data confirm the enhancement in vessel density and cardiac function in 11HSD1-/- mice and demonstrate that this was preceded by enhanced inflammation. This was not due to an underlying cardiac phenotype or modification of the infarct size. Increased infiltration of alternatively activated macrophages may have been the source of pro-angiogenic factor, IL-8, which was also increased at the time of angiogenesis. Importantly the enhanced vessel density was retained 4 weeks after MI, these vessels were mature suggesting longevity and the improvement in cardiac function was retained. While pharmacological inhibition did not recapitulate the effect of the knock out this may have been due to route of administration. The data provides compelling evidence that further development and use of small molecule inhibitors of 11HSD1 may be of benefit post-MI.

Background: Diabetes is a chronic metabolic disease and an increasing public health problem. Treatment of type 1 diabetes requires daily insulin injections. Young people living with diabetes may feel that they do not fit in among others of the same age. Aim: Illustrate young people's experiences of living with diabetes type 1. Method: This study was a qualitative literature-based study with an inductive approach. The result was based on 10 qualitative scientific articles. Result: The analysis resulted in three main themes and seven subthemes. The main themes were: To live in a process of adaptation, A buffet of challenges and How the social surroundings impact the life. Conclusion: The results showed that young people who lived with type 1 diabetes felt that they had to adapt their lives to the disease. For young people it was also important to become independent in their illness. It was obvious that living with type 1 diabetes was an experience of both physical and mental challenge, and the people in the studies expressed a desire to be normal and to be able to compare themselves with others. The social surroundings had a clear impact in many ways, though the support from the environment was perceived as valuable. / Diabetes typ 1 är en ständigt ökande folksjukdom som ofta drabbar unga människor. Diabetes typ 1 är en kronisk ämnesomsättningssjukdom som ställer krav på den unga individen och skapar utmaningar i vardagen. Unga som lever med diabetes påverkas av sin omgivning och är i behov av stöd på olika sätt. Diabetes innebär att individen ständigt har förhöjda blodsockernivåer, till följd av brist på insulin. Unga människor lever i en turbulent period av livet, och att leva med en kronisk sjukdom kan förhindra en utveckling av den egna identiteten. Egenvården upplevs som en viktig del på vägen mot självständighet hos de unga, och sjuksköterskan har en central del i att hjälpa den unga individen att främja hälsa. Syftet är att belysa unga människors upplevelse av att leva med diabetes typ 1. Tio kvalitativa vetenskapliga artiklar har använts som material i resultatet. Resultatet visar att sjukdomen kräver en anpassning av livet. Det är en dragkamp om ansvaret för sjukdomen mellan de unga och deras föräldrar, då självständighet anses viktigt av unga människor för att uppnå frihet, vilket relateras till begreppen livsvärld och hälsa. De unga upplevde både känslomässiga och praktiska utmaningar i livet med diabetes, vilket diskuteras i relation till livskvalitet. En önskan om att få vara normal och kunna jämföra sig med andra i samma ålder finns, eftersom det är en betydande del i de ungas sökande efter en egen identitet. De unga anser att omgivningen påverkar dem på olika sätt, stödet från vänner och familj upplevs som betydelsefullt.

The non-obese diabetic (NOD) mouse is widely used model Type 1 diabetes (T1D), a chronic inflammatory disease characterized by destruction of the insulin producing β cells in the islets of Langerhans by immune cells. The classical symptoms include increased glucose levels in urine and blood, frequent urination and enhanced thirst. The disease has a strong genetic component and is also influenced by the environment. NOD mice develop T1D spontaneously. The disease occurs in two phases; insulitis - the infiltration of immune cells in the islets of Langerhans and overt diabetes caused by the destruction of insulin producing β cells. Several disease associated gene regions or loci [termed insulin dependent diabetes (Idd) loci] have been associated with T1D development. Although, T1D is recognized as a T cell mediated disease in both mouse and man, many studies have shown the importance of B cells in the pathogenesis of the disease. Autoantibodies appear prior to islet infiltration and several molecular and cellular events precede this beta-cell autoimmunity. Although the pathogenesis of T1D is well characterized, less is known about the environmental and immunological factors that trigger the disease. In this thesis, we studied the contribution of B cell anomalies to the skewed immune response observed in the NOD mouse. In our studies covered in the thesis we observed that NOD mice display enhanced IgE in the serum already at one week of age. In addition, upon treatment of pre-diabetic NOD mice with anti-IgE antibodies, diabetes incidence was delayed. We hypothesize that the presence of IgE in the system may be explained due to enhanced class switching. Antibody feedback however, is an essential component of the immune response and can lead to either enhanced or dampened responses. Thus, increased IgE may provide positive feedback that might sustain an immune response. We also aimed to analyze the biological consequence of this feature. In vitro stimulation of B cells by the TACI ligand APRIL resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. In addition, TACI+ cells were observed in NOD germinal centers facilitating increased BAFF uptake and subsequent escape of low affinity antibody producing clones. NOD mice elicited an enhanced and prolonged immune response towards T-dependent antigens such as hen-egg lysozyme (HEL). Serum HEL-specific IgG level was significantly increased and was predominantly of the IgG1 isotype. Immunofluorescence analysis of NOD spleen revealed the presence of spontaneous germinal centers which others have perceived to provide a ready niche for the entry of naïve B cells that encountered novel antigen. Adoptive transfer experiments of purified B and T cells from NOD into NOD.Rag2-/- (NOD-RAG) mice illustrated the importance of B cell intrinsic defects in the reproduction of the original phenotype as observed in NOD.

Lower performance on measures of neuropsychological and academic ability has been noted in adolescents with either Type I Diabetes Mellitus (T1DM) or exposure to traumatic life events. This present study looked to gather information on trauma exposure and symptoms in adolescents with T1DM. The first aim was to compare the neuropsychological and academic achievement performance of Type I Diabetes Mellitus positive adolescents who had experienced a traumatic event with those who had not. Second, the study explored if T1DM positive adolescent’s performance on neuropsychological and academic achievement could be predicted by the number and severity of traumatic stress symptoms they experienced. Finally, the study aimed to explore the nature of trauma exposure of its T1DM positive adolescent participants. Results found limited evidence participants who self-reported trauma exposure performed worse than those who did not on a measure of perceptual reasoning; those with parent-reported trauma exposure scored lower on a measure of visual perception and reasoning as well as an assessment of calculation ability than those whose parents did not. As trauma symptoms scores as reported by either self- or parent-report increased, participant scores on measures of general cognitive ability and attention decreased. As self-reported trauma symptoms increased, performance on perceptual reasoning and psychomotor ability decreased. As parent-reported trauma symptoms increased, vocabulary and verbal abilities decreased. In addition to the results noted for trauma symptom scores, the as the number of self-reported symptoms increased, executive functioning, vocabulary, and verbal abilities decreased. While parent-reported trauma symptoms were not associated with decreased performance on any academic measure, as self-reported trauma symptoms scores increased math calculation, reading comprehension, and writing fluency scores decreased.