| 1. |
- Asplund Samuelsson, Johannes, 1987-
(författare)
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Adaptations and constraints associated with autotrophy in microbial metabolism
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carbon dioxide (CO2) emissions from human activities are driving climate change, but the pending crisis could be mitigated by a circular carbon economy where released CO2 is recycled into commodity chemicals. Autotrophic microbes can make a contribution by producing chemicals, such as biofuels, from CO2 and renewable energy. The primary natural CO2 fixation pathway is the Calvin cycle, in which the enzyme Rubisco carboxylates ribulose-1,5-bisphosphate. The present investigation used computational systems biology methods to map adaptations and constraints in autotrophic microbial metabolism based on the Calvin cycle. First, the metabolic network of the Calvin cycle-capable photoautotrophic cyanobacterium Synechocystis was contrasted with that of heterotrophic E. coli. Intracellular metabolite concentration ranges differed, leading to different capacity to provide thermodynamic driving forces to chemical production pathways. Second, the Calvin cycle in Synechocystis was modeled kinetically, showing that certain enzyme saturation and metabolite levels, for example high ribulose-1,5-bisphosphate concentration, were detrimental to stability. Control over reaction rates was distributed, but making certain enzymes faster, for example fructose-1,6-bisphosphatase, could increase overall carbon fixation rate. Third, Synechocystis was starved of CO2 and ribosome profiling was used to track the effect on translation. Stress response and CO2 uptake were upregulated, but constant Rubisco expression and ribosome pausing in 5' untranslated regions indicated readiness for reappearance of CO2. Finally, microbial genomes with and without the Calvin cycle were contrasted, revealing metabolic, energetic, and regulatory adaptations that describe the properties of a functional autotroph. These findings provide a background for future study and engineering of autotrophs for direct conversion of CO2 into commodity chemicals.
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| 2. |
- Arif, Muhammad
(författare)
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Systems and Network-based Approaches to Complex Metabolic Diseases
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The future of healthcare is personalized medicine, in which disease treatments are tailored based on the individual characteristics of each patient. To reach that objective, we need to obtain a better understanding of diseases. The main facilitator of personalized medicine is systems and data-driven biology, which makes omics data a top commodity in this era. Coupled with computational and biological expertise, omics data can be a useful asset for obtaining mechanistic insights into the biological conundrum, particularly in disease-related contexts. This thesis describes systems biology approaches and their applications in disease-specific contexts. Systems biology assists us in systematically and comprehensively understanding complex biological systems as a whole interconnected system.The first part of the thesis describes the generation of more than 100 biological networks based on personalized data originated from several different omics, usually referred to as multiomics data, including clinical data and metabolomics, proteomics, and metagenomics data collected from the same individuals. Moreover, we present a web-based multiomics biological network database and visualization platform called iNetModels.In the second part of the thesis, we describe systems biology frameworks and their applications to the study of various biological questions in disease contexts using single- and multiomics data. First, we present our findings on the integrative view of metabolic activities from multiple tissues after myocardial infarction using transcriptomics data from the heart and other metabolically active tissues. Second, we used transcriptomics data to describe the mechanistic effect of lifelong training on skeletal muscle in both men and women and the role of short-term training in reversing damage from metabolic-related diseases. Third, we deciphered the molecular mechanism of nonalcoholic fatty liver disease (NAFLD) based on clinical data, plasma metabolomics, plasma inflammatory proteomics, and oral and gut metagenomics data. Finally, we elucidated the mechanism of action of CMA supplementation, a potential treatment for NAFLD, based on proteomics and metabolomics data.In summary, this thesis presents a novel platform for biological network analysis and proven systems biology frameworks to provide mechanistic and systematic understandings of specific diseases using single- and multiomics data.
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| 3. |
- Abdellah, Tebani, et al.
(författare)
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Integration of molecular profiles in a longitudinal wellness profiling cohort.
- 2020
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- An important aspect of precision medicine is to probe the stability in molecular profiles among healthy individuals over time. Here, we sample a longitudinal wellness cohort with 100 healthy individuals and analyze blood molecular profiles including proteomics, transcriptomics, lipidomics, metabolomics, autoantibodies andimmune cell profiling, complementedwith gut microbiota composition and routine clinical chemistry. Overall, our results show high variation between individuals across different molecular readouts, while the intra-individual baseline variation is low. The analyses show that each individual has a unique and stable plasma protein profile throughout the study period and that many individuals also show distinct profiles with regards to the other omics datasets, with strong underlying connections between the blood proteome and the clinical chemistry parameters. In conclusion, the results support an individual-based definition of health and show that comprehensive omics profiling in a longitudinal manner is a path forward for precision medicine.
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| 4. |
- Karlsson, Max, et al.
(författare)
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A single-cell type transcriptomics map of human tissues
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:31
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Tidskriftsartikel (refereegranskat)abstract
- Advances in molecular profiling have opened up the possibility to map the expression of genes in cells, tissues, and organs in the human body. Here, we combined single-cell transcriptomics analysis with spatial antibody-based protein profiling to create a high-resolution single-cell type map of human tissues. An open access atlas has been launched to allow researchers to explore the expression of human protein-coding genes in 192 individual cell type clusters. An expression specificity classification was performed to determine the number of genes elevated in each cell type, allowing comparisons with bulk transcriptomics data. The analysis highlights distinct expression clusters corresponding to cell types sharing similar functions, both within the same organs and between organs.
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| 5. |
- Uhlén, Mathias, et al.
(författare)
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A genome-wide transcriptomic analysis of protein-coding genes in human blood cells
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 366:6472, s. 1471-
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Tidskriftsartikel (refereegranskat)abstract
- Blood is the predominant source for molecular analyses in humans, both in clinical and research settings. It is the target for many therapeutic strategies, emphasizing the need for comprehensive molecular maps of the cells constituting human blood. In this study, we performed a genome-wide transcriptomic analysis of protein-coding genes in sorted blood immune cell populations to characterize the expression levels of each individual gene across the blood cell types. All data are presented in an interactive, open-access Blood Atlas as part of the Human Protein Atlas and are integrated with expression profiles across all major tissues to provide spatial classification of all protein-coding genes. This allows for a genome-wide exploration of the expression profiles across human immune cell populations and all major human tissues and organs.
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