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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Functional characterization of target genes within causal genomic loci of hepatocellular carcinoma. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Amplification of chr.1 q21-22 is also an aberration frequently detected in HCC. Copy number gains of the GEF-H1 gene ranked the most frequent event from array-CGH. GEF-H1 up-regulation was significant correlated in patients with advanced HCC staging (P = 0.048), presence of micro-vascular invasion (P = 0.049) and shorter overall and disease free survival of patients (P < 0.03). Similar to BOP1, functional examinations of GEF-H1 suggested profound inhibitory effects on cell motility ( P < 0.035) and invasiveness (P < 0.003) in cell lines studied. Upon GEF-H1 depletion, re-expression of epithelial markers (E-cadherin, cytokeratin 18, alpha-catenin and gamma-catenin) and down-regulations of mesenchymal markers (N-cadherin, fibronectin and vimentin) were also readily observed. In addition, reduced active form of GTP-RhoA together with its downstream effectors including cleaved ROCK 1 and phosphorylated MLC2 were also found in GEF-H1 depleted cells. / Array-CGH also defined candidate proto-oncogenes within 2 causal amplified regions in HCC, chr.8q24 and chr.1q21-q22. In resolving affected genes at chr.8q24, distinctive gains of BOP1 was further established in primary HCC tumors, where frequent BOP1 up-regulations in tumors compared to adjacent non-tumoral liver (P < 0.0001) was identified. Increased BOP1 expression correlated with advanced HCC staging (P = 0.004), micro-vascular invasion (P = 0.006) and shorter overall and disease free survival of patients (P < 0.02). siRNA-mediated suppression of BOP1 in HCC cell lines showed significant inhibition on cell invasion (P < 0.003) and migration (P < 0.05), whereas overexpression of BOP1 in immortalized hepatocyte cell line, L02, showed increase cellular invasiveness and cell migratory rate (P < 0.0001). Evident regression of the Epithelial-to-Mesenchymal Transition (EMT) phenotype was readily identified in BOP1 knockdown cells, where re-expressions of epithelial markers (E-cadherin, cytokeratin 18 and gamma-catenin) and down-regulation of mesenchymal markers (fibronectin and vimentin) were found. It was found that BOP1 likely stimulates actin stress fibers assembly through RhoA activation. / Hepatocellular carcinoma (HCC) is a highly malignant tumor that is associated with a high incidence of cancer morbidity and mortality. Elucidation of genomic aberrations of HCC holds much importance in understanding the molecular basis that underlies the disease causation and progression. Extensive research on HCC has by now revealed a number of key genomic aberrations but, for most of these loci, the underlying cancer-related gene(s) remains unknown. / In this thesis, array-based comparative genomic hybridization (array-CGH) was deployed to define target genes within HCC-associated chromosomal regions. The first part of my study focused on mapping the homozygous deletions (HDs) in HCC. Though infrequent, HD screening has been widely utilized to define tumor suppressor genes (TSGs) in cancers. A panel of HCC cell lines was systematically examined for the presence of HDs. Array-CGH identified 6 HD regions, amongst which CRYL1 (located on chr.13q12.11) displayed most common down-regulations in primary HCC tumors. Significant associations could also be drawn between repressed CRYL1 and advanced tumor staging, increased tumor size and shorter disease-free patient survival (P ≤ 0.037). Moreover, HD on CRYL1 could be detected in 36% of HCC cases with CRYL1 down-regulations. Examination of other inactivating mechanisms suggested histone deacetylation and promoter hypermethylation to be likely inactivating events as well. Re-expression of CRYL1 in SK-HEP1 cell line induced profound inhibition on cellular proliferation and cell growth (P ≤ 0.002). By Annexin V staining, CRYL1 restoration readily increased pro-apoptotic cells with an induction of P ARP cleavage. Flow cytometry further revealed CRYL1 could prolong the G2-M phase, possibly through interrupting the Cdc2/cyclin B path. / The similarities in functional behaviours of BOP1 and GEF-H1 might have implications in the fundamental biology of HCC tumorigenesis. It is known that HCC is a highly aggressive tumor often associated with intra- and extra-hepatic metastasis. The finding of 2 causal changes to be closely associated with cell migration and invasiveness may have implications in the metastatic potentials of HCC cells being predisposed earlier on from genomic events. / Cheng, Kit Chong Ibis. / Adviser: Nathalie Wong. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 177-190). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
2

Genetic Loci for Paget's Disease of Bone

Good, David Andrew, n/a January 2003 (has links)
Paget's disease of the bone is a skeletal disorder of unknown cause. This disease is characterised by excessive and abnormal bone remodelling brought about by increased bone resorption followed by disorganised bone formation. Increased bone turnover results in a disorganised mosaic of woven and lamellar bone at affected skeletal sites. This produces bone that is expanded in size, less compact, more vascular, and more susceptible to deformity or fracture than normal bone. Symptoms of Paget's disease may include bone pain, bone deformity, excessive warmth over bone from hypervascularity, secondary arthritis, and a variety of neurologic complications caused in most instances by compression of the neural tissues adjacent to pagetic bone. Genetic factors play a role in the pathogenesis of Paget's disease but the molecular basis remains largely unknown. The identification of the molecular basis of Paget's disease is fundamental for an understanding of the cause of the disease, for identifying subjects at risk at a preclinical stage, and for the development of more effective preventive and therapeutic strategies for the management of the condition. With this in mind, the aim of this project is to identify genetic loci, in a large pedigree, that may harbour genes responsible for Paget's disease of bone. A large Australian family with evidence of Paget's disease was recruited for these studies (Chapter 3). This pedigree has characterised over 250 individuals, with 49 informative individuals affected with Paget's disease of bone, 31 of whom are available for genotypic analysis. The pattern of disease in these individuals is polystotic, with sites of involvement including the spine, pelvis, skull and femur. Although the affected individuals have a severe early-onset form of the disease, the clinical features of the pedigree suggest that the affected family members have Paget's disease and not familial expansile osteolysis (a disease with some similarities to Paget's disease), as our patients have extensive skull and axial skeletal involvement. The disease is inherited as an autosomal dominant trait in the pedigree with high penetrance by the sixth decade. Due to the large size of this family and multiple affected members, this pedigree is a unique resource for the detection of the susceptibility gene in Paget's disease. The first susceptibility loci for Paget's disease of bone have been mapped by other investigators to chromosome 6p21 (PDB1) and 18q21.1-q22 (PDB2) in different pedigrees. Linkage analysis of the Australian pedigree in these studies was performed with markers at PDB1: these data showed significant exclusion of linkage, with LOD scores < - 2 in this region (Chapter 4). Linkage analysis of microsatellite markers from the PDB2 region excluded linkage with this region also, with a 30 cM exclusion region (LOD score < -2.0) centred on D18S42 (Chapter 4). This locus on chromosome 18q21.1-q22 contains a serine protease (serpin) cluster with similarities to chromosome 6p21. Linkage analysis of this region also failed to provide evidence of linkage to this locus (Chapter 4). These data are consistent with genetic heterogeneity of Paget's disease of bone. A gene essential for osteoclast formation encoding receptor activator of nuclear factor-kB (RANK), TNFRSF11A, has been previously mapped to the PDB2 region. Mutations in the TNFRSF11A gene have been identified segregating in pedigrees with Familial Expansile Osteolysis and early onset familial Paget's disease, however, linkage studies and mutation screening have excluded the involvement of RANK in the majority of Paget's disease patients. For the Australian pedigree, mutation screening at the TNFRSF11A locus revealed no mutations segregating with affected individuals with Paget's disease (Chapter 4). Based on these findings, our hypothesis is that a novel susceptibility gene relevant to the pathogenesis of Paget's disease of bone lies elsewhere in the genome in the affected members of this pedigree; this gene should be identifiable using a microsatellite genome-wide scan followed by positional cloning. A genome-wide scan of the Australian pedigree was carried out, followed by fine mapping and multipoint analysis in regions of interest (Chapter 5). The peak 2-point LOD scores from the genome-wide scan were LOD = 2.75 at D7S507 and LOD = 1.76 at D18S70. Two additional regions were also considered for fine mapping: chromosome 19p11-q13.1 with a LOD of 1.58 and chromosome 5q35-qter with a LOD of 1.57. Multipoint and haplotype analysis of markers flanking D7S507 did not support linkage to this region (Chapter 5). Similarly, fine mapping of chromosome 19p11-q13.1 failed to support linkage to this region (Chapter 5). Linkage analysis with additional markers in the region on chromosome 5q35-qter revealed a peak multipoint LOD score of 6.77 (Chapter 5). A distinct haplotype was shown to segregate with all members of the family, except the offspring of III-5 and III-6. Haplotype analysis of markers flanking D18S70 demonstrated a haplotype segregating with Paget's disease in a large sub-pedigree (descendants of III-3 and III-4) (Chapter 5). This sub-pedigree had a significantly lower age at diagnosis than the rest of the pedigree (51.2 + 8.5 vs. 64.2 + 9.7 years, p = 0.0012). Linkage analysis of this sub-pedigree demonstrated a peak two-point LOD score of 4.23 at marker D18S1390 (q = 0.00), and a peak multipoint LOD score of 4.71, at marker D18S70. An implication of these data is that 18q23 harbours a novel modifier gene for reducing the age of onset of Paget's disease of bone. A number of candidate Paget's genes have previously been identified on chromosome 18q23, including the nuclear factor of activated T cells (NFATc1), membrane-associated guanylated kinase (MAGUK) and a zinc finger protein. Candidate gene sequencing of these genes in these studies has failed to identify mutations segregating with affected family members in the sub-pedigree linked to chromosome 18q23 (Chapter 6). More recently, a mutation in the gene encoding the ubiquitin-binding protein sequestosome 1 (SQSTM/p62) has been shown to segregate with affected members of Paget's disease families of French-Canadian origin. In this study, a single base pair deletion (1215delC) was identified as segregating with the majority of affected members in the pedigree (Chapter 6). This deletion introduces a stop codon at amino acid position 392 which potentially results in early termination of the protein and loss of the ubiquitin binding domain. The three affected members of the family that do not share the affected haplotype do not carry a mutation in the coding region of SQSTM/p62. Screening of affected members from 10 further Paget's disease families identified the previously reported P392L mutation in 2 (20%) families. No SQSTM1/p62 coding mutations have been found in the remaining 8 families or in 113 aged matched controls. In conclusion, this project has identified genetic loci and mutations that segregate with individuals affected with Paget's disease. Further investigation of the functional significance of the genetic changes at these loci is expected to lead to a better understanding of the molecular basis of this disease.
3

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

Parker, G.J., Leppert, T., Anex, D.S., Hilmer, J.K., Matsunami, N., Baird, L., Stevens, J., Parsawar, K., Durbin-Johnson, B.P., Rocke, D.M., Nelson, C., Fairbanks, D.J., Wilson, Andrew S., Rice, R.H., Woodward, S.R., Bothner, B., Hart, B.R., Leppert, M. 21 July 2016 (has links)
Yes / Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 single nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). This study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts. / The Technology Commercialization Innovation Program (Contracts #121668, #132043) of the Utah Governors Office of Commercial Development, the Scholarship Activities
4

A Clinical and Genetic Study of Psoriatic Arthritis

Alenius, Gerd-Marie January 2003 (has links)
Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. PsA has a heterogeneous pattern, expressed by different manifestations such as mild mono-oligoarthritis or very severe, erosive and destructive polyarthritis. Measurable inflammatory activity is not always prominent. The aetiology is unknown but genetic factors are believed to be of importance. The pattern of inheritance is proposed to be polygenic. The aim of this study was to estimate the prevalence of joint and axial manifestations, characterise the disease in relation to inflammatory and genetic markers, and to identify disease susceptibility gene(s) for PsA in patients from northern Sweden. All patients from the city of Umeå (n=276), selected from a community and hospital based psoriasis register (n=1737) at the Dept of Dermatology, were invited to a prevalence study. Two hundred-two patients were examined and 97 (48%) had inflammatory manifestations such as peripheral arthritis, axial disease, undifferentiated spondylarthropathy (uSpA) and enthesopathies. Of the 67 patients (33 %) with peripheral arthritis and/or axial disease, 30 were not previously diagnosed. The association of clinical manifestations and potential markers of aggressive joint disease with HLA associations were analysed in 88 patients with PsA. We were not able to confirm findings of other groups reporting strong association with several HLA-antigens. The prevalence of HLA-B17, B37 and B62 was increased compared with controls, but the strongest predictive factors among our patients for an aggressive disease, in a multiple logistic analysis, were polyarthritic disease and distal interphalangeal engagement. In order to investigate for disease susceptibility genes, five genetic loci were analysed with microsatellites and single nucleotide polymorphisms in an association study of 120 patients with PsA. There was a significant association with the TNFB locus on chromosome 6p but not with any other loci examined; 1q21 (PSORS4), 3q21 (PSORS5), 8q24 and CTLA4. When stratifying for the TNFB alleles the association was confined to allele 123. In a subgroup of patients who were HLA-typed (n=83), we were not able to verify linkage disequilibrium with the TNFB allele 123 and the HLA antigens; B17, B27, B37, B62 or Cw*0602. The presence of renal abnormalities was evaluated as a manifestation of systemic inflammation in 73 patients with PsA. Renal abnormalities defined as decreased creatinine-clearance (≤ mean - 2SD) and/or urinary albumin &gt;25 mg/24 h was found in 23% of the patients. The predictive factors for renal abnormalities was inflammatory activity (ESR &gt; 25 mm/h and/or CRP &gt;15 mg/L) indicating a systemic effect in some of the patients. In conclusion, we found high prevalence of inflammatory manifestations in patients with psoriasis. There was no strong association between PsA and HLA antigens and predictive factors for aggressive disease were polyarthritic disease and DIP joint engagement. The TNFB locus was associated with PsA and there were no linkage disequilibrium with the HLA antigens B17, B27, B62 or Cw*0602. There were evidence for systemic effects as renal abnormalities in patients with PsA and measurable inflammatory activity.
5

Tamoxifen-Independent Recombination in the RIP-CreER Mouse

Solimena, Michele, Steffen, Anja, Magro, Maria Grazia, Masjkur, Jimmy, Suckale, Jackob, Liu, Yanmei, Anastassiadis, Konstantinos 02 December 2015 (has links) (PDF)
Background The inducible Cre-lox system is a valuable tool to study gene function in a spatial and time restricted fashion in mouse models. This strategy relies on the limited background activity of the modified Cre recombinase (CreER) in the absence of its inducer, the competitive estrogen receptor ligand, tamoxifen. The RIP-CreER mouse (Tg (Ins2-cre/Esr1) 1Dam) is among the few available β-cell specific CreER mouse lines and thus it has been often used to manipulate gene expression in the insulin-producing cells of the endocrine pancreas. Principal Findings Here, we report the detection of tamoxifen-independent Cre activity as early as 2 months of age in RIP-CreER mice crossed with three distinct reporter strains. Significance Evidence of Cre-mediated recombination of floxed alleles even in the absence of tamoxifen administration should warrant cautious use of this mouse for the study of pancreatic β-cells.
6

Genetic and molecular background of ascending aortic aneurysms

Huusko, T. (Tuija) 14 May 2013 (has links)
Abstract Thoracic aortic aneurysms (TAAs) are a significant source of morbidity and mortality. Classical risk factors for TAAs are hypertension, atherosclerosis, male gender, smoking, age, high body mass index, family history and chronic obstructive pulmonary disease. In addition, in certain cases of TAAs, i.e., ascending aortic aneurysms (AscAA), genetic factors are highly prominent. Matrix metalloproteinases are in a major role in the destruction of the aortic wall and the imbalance between matrix metalloproteinases, and their inhibitors are involved in the formation of aneurysms. In addition, osteopontin is a potent regulator of matrix metalloproteinases and it is widely expressed in injured arteries. Recently, telomere shortening has been shown to be involved in the development of abdominal aortic aneurysms (AAA). In this aneurysm type, atherosclerosis has a major role. Since atherosclerosis is frequently absent in the case of TAAs, the length of telomeres was measured in the blood samples of TAA patients. The purpose of this thesis was to study the genetic background of TAAs of the ascending aorta and furthermore, the molecular background of this disease. The first study was done with families with TAAs, and dissections and one chromosomal locus (5q13-14) of the studied seven loci showed a significant genetic linkage for TAAs. Two other studies were done exploiting our TAA case-control material. Study II showed elevated levels of osteopontin, matrix metalloproteinase type 2 and 9 in the plasma and tissue samples of TAA patients compared with controls. In the third study, longer blood leukocyte telomeres were found in the DNA samples of TAA patients compared with controls; furthermore, the elevation of telomere lengthening protein telomerase expression was found in the tissue samples of TAA patients. This thesis presents region 5q13-14 as a potential genetic regulator for TAAs in Finnish families. In addition, elevated levels of osteopontin, matrix metalloproteinase type 2 and 9 can be considered as a plasma biomarker for aneurysmal disease. Furthermore, longer blood leukocytes were found to be a significant risk factor for developing TAAs. / Tiivistelmä Rinta-aortan aneurysmat ovat merkittävä sairastumisiin ja kuolemiin johtava tekijä. Perinteisinä riskitekijöinä aneurysmille on pidetty korkeaa verenpainetta, ateroskleroosia, miessukupuolta, tupakointia, ikää, ylipainoa, suvussa esiintyneitä aneurysmatapauksia ja keuhkoahtaumatautia. Näiden lisäksi erityisesti nousevan rinta-aortan alueella esiintyvissä aneurysmissa myös perinnöllisillä tekijöillä on korostunut merkitys. Matriksimetalloproteinaaseilla ja niiden estäjillä on merkittävä rooli, kun aortan seinämää hajotetaan. Tasapainon järkkyminen kyseisten proteiinien keskinäisessä suhteessa voi johtaa aneurysman muodostumiseen. Myös osteopontiinin tiedetään olevan tehokas matriksimetalloproteinaasien säätelijä, ja sitä tuotetaankin yleisesti vahingoittuneessa verisuonessa. Telomeerien lyhentyminen on vastikään yhdistetty vatsa-aortan alueella esiintyviin aneurysmiin, joissa ateroskleroosilla on yleensä merkittävä rooli. Koska ateroskleroosi on vain harvoin nousevan rinta-aortan alueen aneurysmien taustalla, rinta-aortan aneurysmapotilaiden valkosolujen telomeerien suhteelliset pituudet määritettiin. Väitöskirjan ensimmäisessä osatyössä keskityttiin löytämään geneettinen kytkentä rinta-aortan aneurysmien ja jonkin seitsemän tutkitun kromosomialueen välille. Geneettinen kytkentä löydettiin kromosomialueelta 5q13-14. Osatöissä 2 ja 3 hyödynnettiin rinta-aortan aneurysmien potilas- ja verrokkiaineistoja. Osatyö 2 osoitti, että matriksimetalloproteinaasien (2 ja 9) määrät ovat kohonneet rinta-aortan aneurysmapotilaiden näytteissä verrokkeihin verrattuna. Osatyössä 3 telomeerien suhteelliset pituudet veren valkosoluissa olivat pidemmät nousevan rinta-aortan aneurysmapotilaiden näytteissä verrokkihenkilöiden näytteisiin verrattuna. Myös telomeraasin tuotto oli lisääntynyt rinta-aortan aneurysmapotilaiden aorttakudosnäytteissä. Väitöskirjassa esitetään tuloksena kromosomialue 5q13-14 geneettisenä säätelijänä suomalaisissa suvuittain esiintyvissä rinta-aortan aneurysmatapauksissa. Kohonneita matriksimetalloproteinaasien ja osteopontiinin tasoja voidaan lisäksi pitää biomarkkereina rinta-aortan aneurysmien sairastavuudelle. Veren valkosolujen pidemmät telomeerit näyttävät myös olevan yhteydessä rinta-aortan aneurysmien sairastavuuteen.
7

Tamoxifen-Independent Recombination in the RIP-CreER Mouse

Solimena, Michele, Steffen, Anja, Magro, Maria Grazia, Masjkur, Jimmy, Suckale, Jackob, Liu, Yanmei, Anastassiadis, Konstantinos 02 December 2015 (has links)
Background The inducible Cre-lox system is a valuable tool to study gene function in a spatial and time restricted fashion in mouse models. This strategy relies on the limited background activity of the modified Cre recombinase (CreER) in the absence of its inducer, the competitive estrogen receptor ligand, tamoxifen. The RIP-CreER mouse (Tg (Ins2-cre/Esr1) 1Dam) is among the few available β-cell specific CreER mouse lines and thus it has been often used to manipulate gene expression in the insulin-producing cells of the endocrine pancreas. Principal Findings Here, we report the detection of tamoxifen-independent Cre activity as early as 2 months of age in RIP-CreER mice crossed with three distinct reporter strains. Significance Evidence of Cre-mediated recombination of floxed alleles even in the absence of tamoxifen administration should warrant cautious use of this mouse for the study of pancreatic β-cells.
8

Genetic background of HDL-cholesterol and atherosclerosis:linkage and case-control studies in the Northern Finnish population

Kangas-Kontio, T. (Tiia) 01 November 2011 (has links)
Abstract Coronary heart disease (CHD), a manifestation of atherosclerosis, is the leading single cause of death in Finland. CHD is affected by numerous genetic and environmental factors, their combined effects and interactions between them. Low HDL-cholesterol (HDL-C) is an independent risk factor for atherosclerosis and the most common dyslipidemia associated with early onset CHD, but the mechanisms regulating HDL-C levels and protecting from atherosclerosis are still not completely understood. Adiponectin is a hormone that is secreted by adipose tissue and has several anti-atherosclerotic effects. There is multiple evidence suggesting that adiponectin could protect against CHD via positive effects on HDL metabolism. Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor that has a potentially conflicting role in atherosclerosis; it may have protecting or predisposing effects. The objective of this thesis was to study the genetic background of HDL-C regulation and atherosclerosis. Three studies were executed using extended families with CHD or case-control setting, with samples collected from Northern Finland. In the first study, seven chromosomal regions showing suggestive evidence of linkage were identified for HDL-C regulation, using genome-wide linkage approach. In the second study, we found a strong correlation between HDL-C and adiponectin, but failed to show evidence of a shared genetic background. However, a genetic correlation between adiponectin and low-density lipoprotein-cholesterol was revealed. We also studied the genetic regulation of adiponectin, and for the first time its most active form, high-molecular weight adiponectin, and found suggestive evidence of linkage to three chromosomal regions. In the third study, it was discovered that the studied VEGF gene polymorphisms did not have a major effect on atherosclerosis quantified as carotid intima-media thickness or the risk of acute myocardial infarction (AMI). This thesis presents potential regions for the genetic regulation of HDL-C and adiponectin and gives new information about their relationship and the effect of VEGF polymorphisms in atherosclerosis. The strong correlation between adiponectin and HDL-C was further strengthened, but we failed to show a shared genetic background between them. / Tiivistelmä Sepelvaltimotauti, eräs valtimonkovettumataudin ilmentymä, on yleisin yksittäinen kuolinsyy maassamme. Taudin syntyyn vaikuttavat lukuisat geneettiset ja ympäristötekijät sekä niiden väliset yhteis- ja vuorovaikutukset. Pieni HDL-kolesterolipitoisuus on valtimonkovettumataudin itsenäinen riskitekijä ja yleisin kolesterolipoikkeavuus, joka liittyy varhain ilmenevään sepelvaltimotautiin. HDL-kolesterolin vaihtelun syitä ja tämän "hyvän kolesterolin" sepelvaltimotaudilta suojaavia vaikutusmekanismeja ei kuitenkaan pystytä täysin selittämään. Adiponektiini on rasvakudoksen tuottama hormoni, jonka sepelvaltimotaudilta suojaavan ominaisuuden on ehdotettu johtuvan siitä, että se vaikuttaisi HDL-kolesterolin aineenvaihduntaan. VEGF (vascular endothelial growth factor) on verisuonten sisäseinämissä vaikuttava kasvutekijä, jolla saattaa olla joko sepelvaltimotaudilta suojaavia tai sille altistavia vaikutuksia. Väitöskirjatyön tavoitteena oli tutkia HDL-kolesterolin ja valtimonkovettumataudin geneettistä taustaa. Kolmessa osatyössä tutkittiin suuria pohjoissuomalaisia sepelvaltimotautisukuja; lisäksi käytettiin väestö- ja potilasaineistoja. Ensimmäisessä tutkimuksessa löydettiin koko genomin kytkentäkartoitusmenetelmällä seitsemän kromosomialuetta, jotka saattavat vaikuttaa HDL-kolesterolin säätelyyn. Toisessa tutkimuksessa selvitettiin adiponektiinin, ja ensimmäistä kertaa myös sen aktiivisimman muodon, HMW-adiponektiinin geneettistä taustaa. Kytkentäanalyysissä saatiin viitteitä kolmesta adiponektiineja mahdollisesti säätelevästä kromosomialueesta. Havaittiin myös, että HDL-kolesterolin ja adiponektiinin pitoisuudet korreloivat vahvasti keskenään, mutta yhteistä geneettistä säätelytekijää ei pystytty osoittamaan. LDL-kolesterolin ja adiponektiinin välillä kuitenkin havaittiin geneettinen korrelaatio. Kolmannessa tutkimuksessa todettiin, ettei tutkituilla VEGF-geenin nukleotidimuutoksilla todennäköisesti ole merkittävää syy-yhteyttä valtimonkovettumatautiin kaulavaltimoiden sisäseinämän paksuudella tai sydäninfarktiriskillä mitattuna. Tämä tutkimus tuo uutta tietoa HDL-kolesterolin ja adiponektiinin geneettisestä säätelystä ja niiden suhteesta sekä VEGF-geenin nukleotidimuutosten osuudesta valtimonkovettumataudissa. Tutkimus vahvistaa edelleen HDL-kolesterolin ja adiponektiinin yhteyden, muttei pysty osoittamaan niille yhteistä geneettistä tekijää.

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