Browsing by Author "Haltia, Hanna"

The prevalence of obesity is increasing worldwide, and it is associated with many diseases, such as type II diabetes and cardiovascular disease. Obesity and its co-morbidities are significant contributors to the global disease burden, and consequently, healthcare costs. Two interconnected disturbances in the white adipose tissue of a person with obesity that likely contribute significantly to the development of the metabolic complications are poorer mitochondrial function and chronic low-grade inflammation, whose connection to each other is poorly known. The aim of the project was to develop a cell model in which the expression of mitochondria-related genes has been reduced in human preadipocytes differentiated toward the mature white adipocyte lineage to mimic the effect of obesity. The model can be used in further studies in which the effects of reducing mitochondrial gene expression in cells, such as the inflammatory response, are investigated. RNA interference (RNAi) was used to reduce the expression of mitochondria-related genes. The method aimed at downregulating the expression of the mitochondrial genes by targeting to silence the protein that regulates the transcription of the genes encoding mitochondrial proteins in the nuclear genome (PPARGC1a). The performance of the RNAi method was evaluated by comparing RNAi cells and untreated controls from the same cell line. Based on the results, the RNAi cells had reduced expression of the targeted genes compared to the control cells, and the amounts of the proteins encoded by the silenced genes were reduced in the RNAi cells as well. Furthermore, by visually inspecting in microscopy, the RNAi treatment did not compromise the adipogenic differentiation, and both the RNAi and control cells differentiated equally well. In conclusion, the method can effectively decrease the expression of the targeted genes in differentiated human preadipocytes. The model is intended to be used in a continuation project to study the relationship between the reduced mitochondrial gene expression and inflammation. More detailed characteristics and functional parameters of the cell model still require further research.