Projects / Programmes
Functional genomics of cholesterol homeostasis: the role of lanosterol 14alpha-demethylase in development of metabolic disorders
| Code |
Science |
Field |
Subfield |
| 7.00.00 |
Interdisciplinary research |
|
|
| Code |
Science |
Field |
| B000 |
Biomedical sciences |
|
| Code |
Science |
Field |
| 3.05 |
Medical and Health Sciences |
Other medical sciences |
Cholesterol, cytochrome P450, lanosterol 14alpha-demethylase, CYP51, lipid homeostasis, circadian rhythm, fatty liver disease
Researchers (18)
Organisations (5)
Abstract
As opposed to the consequences of elevated cholesterol, little is known about pathologies linked to the lack of cholesterol and gene defects of this metabolic path. Lanosterol 14a-demethylase CYP51 is the major regulatory enzyme of the post-squalene part of cholesterol synthesis. Defects in this gene have so far not been linked to human pathologies. There is neither known how the absence of one functional CYP51 allele influences the phenotype and to what pathological symptoms an inherited or an acquired defect of cholesterol synthesis in the liver can lead. In preliminary work we developed transgenic mice with conditionally knockout Cyp51 gene. These original animal models represent a basis for the discovery of phenotypes of humans possessing one non-functional CYP51 allele, or showing a diminished expression of CYP51 enzyme in the whole body or the liver. Results of measurements gathered to-date, of the weight and blood parameters of Cyp51+/ - on a limited number of mice reveal important differences between the sexes. Between 6th and 12th weeks after birth, Cyp51+/ males have a statistically significant lower weight than males of wild type, they exhibit a lower weight of the brain and a higher total blood cholesterol and testosterone. In Cyp51+/ females, there was in the 12th week observed a lower mass of abdominal fats. Also the liver knockout of Cyp51-/lox;Alb-Cre+ mice shows important differences between the sexes. It seems that females are more affected as in samples examined to-date, hepatosteatosis in a more progressive state in comparison with males, can be observed. In the proposed project we aim to continue this research, having the following objectives: (1) To define the role of heterozygosity on the Cyp51+/ mouse phenotype of both sexes; (2) To define the consequences of the Cyp51 knockout in the liver in mice of both sexes; (3) To find polymorphisms of CYP51 gene at target patient populations; (4) To ascertain functional links between Cyp51 genotype/phenotype of transgenic mice and patients. To reach these objectives, we will examine biological samples of transgenic mice Cyp51+/-, Cyp51lox/lox;Alb-Cre+ and Cyp51-/lox;Alb-Cre+, which will be fed with different diets (diet rich with lipids, or without cholesterol), with or without additionl circadian rhythm desynchronisation. We will screen DNA collections of target groups of patients, such as prematurely born children of both sexes from the study of our American collaborator in the project, and selected female and male patients from the Clinical Department of Endocrinology of the University Clinical Centre in Ljubljana. We will apply experimental approaches of functional genomics (high-throughput analyses of transcriptome, SNP and sequencing, promotor analyses, metabolomics, determining blood parameters, western analysis, immunohistochemistry, etc.), bioinformatics, and data mining. These approaches will enable a wholistic insight into the irregularities appearing due to deficient expression of Cyp51 and synthesis of cholesterol so that phenotypes of mice could be translated to the human. The approaches are original, being in conformance with the European directives of translational research as well as in conformance with the trends in the development of personalized medicine of the post-genomic era.
Significance for science
Discovery of Novel Scientific Findings. By applying original animal models and global approaches with combination of experimental and computational methods, molecular mechanisms will be assessed, thereby importantly contributing to a global understanding of the malformations linked to disturbances of cholesterol synthesis in the whole organism and in the liver. Our basic research in these areas already attained a international recognition, which is evident from the list of publications and the citation index. Improving and Enlarging Methodology Tools. We introduced the DNA chip technology into the Slovenian research sphere, and together with other consortium members and partners from industry also provided the necessary infrastructure. In 2011 we aim to introduce to Slovenia as well the novel generation sequencing infrastructure and knowledge and apply it to this project. Development of Own Basic Research. Scientific findings stated above belong to the category of fundamental scientific findings in the field of biochemistry and molecular biology and functional genomics, genetics and endocrinology – metabolic and hormonal disturbances, altogether representing a venue of translational medicine where discoveries in (animal) models are used to improve human health. Publications of recent years result from own basic research in cooperation with international partners. Development of Other Fundamental Sciences. The proposed project is explicitly of interdisciplinary character. The newest tools of functional genomics are applied, and besides offering fundamental knowledge in the basic field of biochemistry, molecular biology, endocrinology and genomics it also reaches into the domain of bioinformatics and modeling. It is expected that investigations planned in the present project will exert an influence on all fields stated. Development of Applicative Research. Involvment of clinical institutions and a company will directly apply the knowledge collected within the project.
Significance for the country
The project applied experimental and computational procedures that can significantly contribute to the cost reduction and to the increase of quality in discovery of new knowledge in biomedicine, particularly in fatty liver disease. Wide availability of various experimental data and biomedical knowledge resources requires close collaboration between biomedical and computational science, to integrate data and existing knowledge and allow data reusing and reduction of experimental costs. This also increases the robustness of hypotheses that lead to discovery of new biomedical knowledge, drugs, health care procedures and treatments. Slovenia is lagging behind in this area of interdisciplinary sciences and is lacking expertise in their use in practical projects. The completed project aimed at bridging this gap, by applying most novel post-genome experimental and computational approaches on a biomedically relevant issue of the multifactorial fatty liver diseases, training at the same time several young scientists. In the longer term, the project will contribute to fighting against metabolic syndrome, which is one of the most challenging medical issues of our time. Open access to this new knowledge could boost innovative capacity of pharmaceutical industries. By providing new health indicators and potentially developing personalized disease/drug risk predictors and by publishing developments on the web and other public media, this project will contribute to “health literacy” of citizens.
Most important scientific results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
