<p>The main purpose of the theses is to explore the significance of anxiety and depression in patterns of pain, fatigue, quality of life. Lifestyle, functional disability, co-morbidity and gender among individuals given the diagnosis of fibromyalgia by their doctor.</p>

<p>Diabetic nephropathy (DN) is associated with morbidity and mortality due to cardiovascular disease and renal failure. This study focused on the impact of glycemic control on the development of DN and the metabolic consequences of DN. The euglycemic hyperinsulinemic clamp technique was used to assess insulin sensitivity and insulin clearance. Two different registries, the Diabetes Incidence Study in Sweden (DISS) and the Swedish Childhood Diabetes Registry, as well as questionnaires and data from medical records were used to study diabetic complications in population-based cohorts.</p><p>Microalbuminuria is an early marker of DN and may also be associated with impaired insulin sensitiv-ity in diabetic and non-diabetic subjects. We studied the relationship between insulin sensitivity and the degree of albuminuria in patients with type 1 diabetes and micro- or macroalbuminuria but normal glomerular filtration rate (GFR). We did not find a direct quantitative association between the degree of albuminuria and insulin resistance, arguing against a cause-effect relationship.</p><p>With progression of DN, a decline in GFR is seen. Patients with severe renal failure have both im-paired insulin sensitivity and insulin clearance. We studied insulin sensitivity and insulin clearance in type 1 diabetes patients with three different degrees of renal involvement (none, only albuminuria, and slightly reduced GFR, ~40-70 ml/min/1.73 m2, respectively). A clear reduction in insulin sensitivity in vivo, but not in insulin clearance, was seen in the group with reduced GFR, and concomitant changes in the levels of PTH, IGF-1, IL-6 and TNF-α were found. In parallel, cellular insulin sensitivity and insulin degradation were examined in vitro, in subcutaneous fat cells but no differences were found between the three groups of patients.</p><p>To study the occurrence of renal involvement in patients with modern diabetes treatment we moni-tored a cohort of young adults from the DISS-registry with onset of diabetes in 1987-88 at age 15-34 years. We found that ~7% of the patients had signs of renal involvement, i.e. incipient nephropathy (5%) and overt nephropathy (2%), after a median follow-up of ~9 years and the strongest risk markers were poor glycemic control (HbA1c) and high blood pressure. Patients with type 2 diabetes were most prone to have renal involvement in this age group.</p><p>Retrospectively, we studied 94 patients diagnosed with type 1 diabetes in 1981-1992 at age 0-14 years at the Umeå University Hospital. Incipient nephropathy and background retinopathy occurred in 18 and 45%, respectively, of the patients, during ~12 years of follow-up. Glycemic control, also during the first five years of diabetes, was a strong risk marker. Young age at onset of diabetes prolonged the time to development of microvascular complications.</p><p>Conclusion: Despite modern diabetes treatment some patients with diabetes develop renal involvement within the first ten years. Inadequate glycemic control, also early in the disease, is a risk marker as well as type 2 diabetes and high blood pressure. In patients with type 1 diabetes and diabetic neph-ropathy a slightly reduced GFR, but not albuminuria, is associated with insulin resistance. Concomi-tant changes in insulin-antagonistic hormones and cytokines may be involved.</p>

<p>Neuroblastoma is a malignant childhood cancer, originating from sympathetic neuroblasts of the peripheral nervous system. Neuroblastoma is a heterogenous group of tumours, while some are highly malignant others can spontaneosly mature into a more benign form or regress. Less than half of the patients survive and this statistics has improved only modestly over the past 20 years. </p><p>SH-SY5Y is a human neuroblastoma cell line established from a highly malignant tumour. The cells have retained a capacity to differentiate <i>in vitro</i> in response to low concentrations of the phorbolester 12-O-tetradecanoylphorbol-13-acetate (TPA) in the presence of serum or defined growth factors. Differentiated cells are characterised by neurite formation and upregulation of neuronal marker genes. SH-SY5Y are unresponsive to nerve growth factor (NGF), but when transfected to express the NGF-receptor TrkA, they differentiate in response to NGF. Protein kinase C (PKC) is pivotal for the differentiation response to take place.</p><p>We have investigated the role of signaling through the Ras-MAPK pathway in differentiating SH-SY5Y, with respect to neurite formation, expression of neuronal marker genes and growth control. Our results show that differentiation-promoting treatment induced a sustained activation and nuclear accumulation of the MAPK ERK in SH-SY5Y. The nuclear accumulation of ERK was PKC-dependent. However, nuclear accumulation of ERK was not sufficient for a differentiation response to take place in these cells, but ERK activity was needed for the characteristic upregulation of <i>NPY</i> and <i>GAP-43</i> induced by TPA. ERK activity did not induce neurite formation, neither was it necessary for TPA-induced neurite formation. Instead, stimulation of a pathway distinct from MEK/ERK, but downstream of Ras, was needed for morphological differentiation. We could also show that differentiated cells still entered S-phase and that there was no correlation between expression of the CKI p21_cip1 (an ERK target), BrdU-incorporation or neurite formation. </p>

<p>Glioblastoma multiforme is a malignant brain tumor characterized by heterogeneity.Interactions between heterogeneous tumor cells are supposed to affect the behavior of awhole tumor cell population. In this thesis an <i>in vitro</i> model system of clonal glioma celllines originating from one glioblastoma tumor was used, and the behavior of cells incocultures was studied and compared the behavior of cells grown separately. The resultsindicate the presence of two types of interactions. In one, paracrine signals acted via extra-cellular media. This was associated with increased growth of the whole co-culture followedby a selective force driving one clone to dominance. In the other type, the cell clones grewside by side without signs of paracrine signalling, in a balance resulting in an increasedterminal cell density. Further investigations focused on mechanisms of interactions in thiscombination.</p><p>Two cell clones were chosen, a GFAP⁺ and a GFAP^-, for further experiments. Withdifferential display PCR it was possible to investigate their specific gene expressionpatterns. Seventeen cDNA fragments were differentially expressed, among them twocorresponded to known transcription factors, ATF3 and prox-1, one to a cytoskeletal protein,α-tropomyosin. The collection also contained eight ESTs (Expressed Sequence Tags) wherethe corresponding genes are unknown at present. Expression of the isolated sequences werealso analyzed in a panel of 12 different glioma cell lines and the results illustrate thecomplexity of gene expression and of tumor heterogeneity. Genes, the expression levels ofwhich were modulated in co-cultures and/or were cell density dependent, were alsoidentified.</p><p>PDGF B is suggested to play a role in sarcomas. The gene codes for an mRNA transcriptwith long UTRs, parts of which are deleted in the homologous oncogene <i>v-sis</i>. The UTRs ofPDGF B mRNAs in human sarcomas were investigated for deletions similar to <i>v-sis</i> thatmight result in increased protein levels. A new transcript variant was identified, lacking a149 base region in the 3'UTR, but its presence was not associated with increased levels ofprotein. Alterations in the 5'UTR were found more likely to be associated with increasedprotein levels.</p>

<p>Adenovirus infected cells provide a good model system for studying nuclear organization during RNA production and transport. This thesis is focused on the dynamic organization of splicing factors during the late phase of Adenovirus infection in HeLa cells, the nuclear localization of viral RNA, and the pathway used for viral RNA transport to the cytoplasm.</p><p>Splicing factors are relocalized from interchromatin granule clusters to sites of transcription in Adenovirus infected cells at intermediate times of infection. Later, splicing factors and viral RNA accumulate posttranscriptionally in interchromatin granule clusters. The release of the splicing factors from transcription sites was energy dependent or preceded by energy requiring mechanisms. Our data indicated that phosphorylation events inhibited by staurosporine, and 3' cleavage of the transcript are two possible mechanisms involved prior to the release of the RNP complex from transcription sites.</p><p>A viral protein derived from orf6 of early region 4, 34K, is important for the nuclear stability and transport of late viral mRNA derived from the major late transcription unit. A viral mutant lacking this region is defective for posttranscriptional accumulation of viral mRNA in interchromatin granule clusters, and for the accumulation of viral RNA in the cytoplasm. These results suggest that posttranscriptional accumulation of viral RNA in interchromatin granule clusters may contribute to the maturation of the RNP complex or sorting of RNAs and proteins, to prepare the final RNP complex for transport to the cytoplasm.</p><p>A previous model suggested that adenoviral late mRNA is transported to the cytoplasm by utilizing the CRM-1 pathway. This pathway can be blocked by the drug leptomycin B. The data presented in paper IV suggests that this model might not be applicable, since leptomycin B did not inhibit adenoviral late gene expression.</p>

<p>Platelet-derived growth factor receptor α (PDGFRα) plays an important role during embryogenesis. After implantation, the patterns of expression of Pdgfrα and its ligand Pdgf-A undergo an "autocrine-paracrine transition", in that Pdgf-A becomes expressed in the ectoderm and epithelia, while Pdgfrα is expressed in the adjacent mesenchymal tissue. In human tumors, such as malignant glioma, both PDGF and PDGFRα are overexpressed within the same tissue, indicating that an autocrine PDGF loop is generated in the tumors. This thesis is focused on the <i>in vivo</i> functionality of the <i>PDGFR</i>α gene (<i>PDGFRA</i>) promoter, arid on the effect of autocrine PDGF-A stimulation in transgenic n-iice during embryogenesis. </p><p>To test the <i>in vivo</i> promoter function of a human PDGFRA 2.2 kb 5' flanking fragment, we generated transgenic mouse lines and found that the 2.2 kb fragment was able to promote lacZ reporter gene expression in most of the endogenous Pdgfra expressing tissues. Absence of expression and "ectopic" expression of the transgenic lacZ were also observed. To investigate the autocrine PDGF effect, we produced autocrine PDGF-As (A short-chain) transient transgenic embryos. These transgenic embryos carried a 6 kb mouse <i>Pdgfra</i> 5' flanking sequence linked to a human PDGF-As cDNA. The pattern of expression of the PDGF-As transgene mRNA was similar to that of lacZ. Some of the transgenic embryos exhibited severe abnormal phenotypes, such as midline fusion defects in the cephalic and craniofacial region and small body size, and these embryos die at mid-gestation stage. These findings indicate that a paracrine pattern of expression and the dosage of PDGF are important for sustaining normal embryo development, especially with regard to the middline fusion in craniofacial regions. </p><p>The possible signaling pathways that may be involved in regulating <i>Pdgfra</i> activity were also studied by comparison of patterns of mRNA expression of Gli, Ptc, and Paxl with that of Pdgfra. The results pointed to the possibility that the Shh signaling pathway may be involved in the regulation of <i>Pdgfra</i> expression for example during early bone and foregut development. The specific regulatory mechanisms may vary for different tissues.</p>

<p>Mutation of the p53 gene appears to be an early event in skin cancer development. The present study is based on morphology and represents a cellular and genetic investigation of p53 alterations in normal human skin and basal cell cancer.</p><p>Using double immunofluorescent labelling, we have demonstrated an increase in thymine dimers and p53 protein expression in the same keratinocytes following ultraviolet radiation. Large inter-individual differences in the kinetics of thymine dimer repair and subsequent epidermal p53 response were evident in both sunscreen-protected and non-protected skin. The formation of thymine dimers and the epidermal p53 response were partially blocked by topical sunscreen. We have optimized a method to analyze the p53 gene in single cells from frozen tissue sections. In chronically sun-exposed skin there exist clusters of p53 immunoreactive keratinocytes (p53 clones) in addition to scattered p53 immunoreactive cells. Laser assisted microdissection was used to retrieve single keratinocytes from immunostained tissue sections, single cells were amplified and the p53 gene was sequenced. We have shown that p53 mutations are prevalent in normal skin. Furthermore, we detected an epidermal p53 clone which had prevailed despite two months of total protection from ultraviolet light. Loss of heterozygosity in the PTCH and p53 loci as well as in the sequenced p53 gene was determined in basal cell cancer from sporadic cases and in patients with Gorlin syndrome. Allelic loss in the PTCH region was prominent in both sporadic and hereditary tumors, while loss of heterozygosity in the p53 locus was rare in both groups. p53 mutations found in the hereditary tumors differed from the typical mutations found in sporadic cases. In addition, we found genetically linked subclones with partially different p53 and/or PTCH genotypes in individual tumors. Our data show that both genes are important in the development of basal cell cancer.</p>

<p>All-trans retinoic acid (ATRA), a biologically active metabolite of vitamin A, is a powerful inducer of terminal differentiation and growth arrest of several myeloid cell lines <i>in vitro</i>. Although the efficacy of ATRA as an anti-cancer drug has been demonstrated by the successful treatment of acute promyelocytic leukemia (APL), knowledge concerning the molecular mechanisms directing ATRA-induced differentiation and cell cycle arrest of myeloid cells is lacking. Our results show, for the first time, that the complex regulation of cell cycle proteins and myeloid-specific transcription factors induced by ATRA relies on functional Stat1. We found that Stat1 is activated by both tyrosine-701 and serine-727 phosphorylation upon ATRA-induced differentiation of the human monoblastic cell line U-937. Expression of phosphorylation deficient mutants of Stat1 (Stat1Y701F or Stat1S727A) inhibited both ATRA-induced differentiation and cell cycle arrest of U-937 cells, pointing to a requirement of active Stat1 in these processes. </p><p>Detailed analysis of the molecular mechanism of ATRA-induced cell cycle arrest and differentiation showed that the onset of cell cycle arrest was associated with a decrease in c-Myc and cyclin E levels and upregulation of p27^Kip1 and p21^WAF1/CIP1. This was followed by a rapid fall in cyclin A and B and a coordinate dephosphorylation of the retinoblastoma protein (pRb). The inhibition of ATRA-induced cell-cycle arrest by constitutive expression of Stat1Y701F or Stat1S727A was associated with impaired regulation of these cyclins and p27^Kip1, positioning Stat1 activation upstream of these events. To further understand the process of ATRA-induced differentiation, the regulation of myeloid-specific transcription factors was investigated during ATRA-treatment. Notably, ATRA-induced upregulation of Stat2, ICSBP and C/EBP-ε was selectively impaired in sublines expressing Stat1Y701F or Stat1S727A, suggesting an important function of these factors downstream Stat1. Taken together, the work in this thesis clearly demonstrates that Stat1 plays a key role in ATRA-induced terminal differentiation of myeloid cells, through regulation of cell cycle proteins and myeloid-specific transcription factors. </p>

<p>A series of novel methods for detection of known sequence variants in DNA, in particular single nucleotide polymorphism, using padlock probes and rolling circle replication are presented. DNA probes that can be circularized – padlock probes – are ideal for rolling circle replication. Circularized, but not unreacted probes, can generate powerful signal amplification by allowing the reacted probes to template a rolling circle replication (RCR) reaction. However, when hybridized and ligated to a target DNA molecule with no nearby ends, the probes are bound to the target sequence, inhibiting the RCR reaction is. This problem can be solved by generating a branched DNA probe with two 3’ arms such that the probes may be circularized while leaving the second 3’ arm as a primer for the RCR reaction. We describe how T4 DNA ligase can be used for efficient construction of DNA molecules having one 5’ end but two distinct 3’ ends that extend from the 2’ and 3’ carbons of an internal nucleotide. An even stronger approach to circumvent the topological problem that can inhibit RCR is to restriction digest the template downstream of the padlock recognition site. By using Phi 29 DNA polymerase with efficient 3’ exonuclease and strand displacement activity, the template strand can then be used to prime the RCR reaction. The amplified molecule is contiguous with the target DNA, generating an anchored localized signal. The kinetics of the reaction was investigated by following the reaction in real-time using molecular beacon probes. Localized RCR signal were obtained on DNA arrays, allowing detection of as little as 104-105 spotted molecules, of either single- or double-stranded M13 DNA, in a model experiment. We have also established a serial rolling circle amplification procedure. By converting rolling circle products to a second and even third generation of padlock probes the signal was amplified thousand-fold per generation. This procedure provides sufficient sensitivity for detection of single-copy gene sequences in 50 ng of human genomic DNA, and large numbers of probes were amplified in parallel with excellent quantitative resolution.</p>

<p>Angiogenesis can be defined as the formation of new blood vessels from pre-existing ones. Angiogenesis is required for development and maintenance of our vascular system and thus of fundamental importance to our existence. The endothelial cells that line the inside of the vessels de-differentiate, migrate, proliferate and re-differentiate during angiogenesis. Angiogenesis is tightly regulated, controlled by several angiogenic factors of various classes that promote angiogenesis but also by anti-angiogenic factors that counteract the effect of the pro-angiogenic factors. We have examined three factors involved in angiogenesis regulation, Vascular endotelial growth factor (VEGFR) -3, the matrix protein laminin-1 and the collagen XVIII derived fragment endostatin. </p><p>Five tyrosine phosphorylation sites in the cytoplasmic tail of VEGFR-3 were identified by phosphopeptide mapping (PPM). The data was confirmed by PPM using point-mutated receptors generated by site-directed mutagenesis.</p><p>Laminin-1 was found to promote angiogenesis in the chicken chorioallantoic membrane assay and in a synergistic fashion together with suboptimal levels of fibroblast growth factor 2 (FGF-2) in embryoid bodies. Laminin-1 also promoted endothelial tubular morphogenesis in vitro, and upregulated the expression of the endothelial differentiation marker Jagged-1. </p><p>Endostatin was shown to affect endothelial FGF-2-induced cell survival and morphogenesis. This was a result of direct binding to endothelial cells and induction of tyrosine phosphorylation of many proteins including the adaptor protein Shb. The apoptotic and morphogenic responses induced by endostatin was shown to be dependent on Shb. Further, endostatin inhibited endothelial migration and affected molecules implicated in migration. In particular, FGF-2 induced actin reorganization, and β-catenin regulation was modulated by endostatin. </p>