B29 Alterations in mitochondrial function in huntington’s disease fibroblasts

Background There are many reports of mitochondrial dysfunctions present in nervous cells of Huntington’s disease (HD) patients including mitochondrial respiratory chain inhibition, decreased ATP production, increased free radical (ROS) production, loss of mitochondrial membrane potential and alternation in mtDNA structure and amount. The current state of knowledge and our previous research indicate that many oxidative damages are observed also in peripheral tissues. Aims The aim of the present study was to characterise mitochondrial abnormalities in human skin fibroblasts obtained from HD patients at different stages of the disease compared to healthy controls. Methods Mitochondrial activity (rezazurin test), ROS level (MitoSox and CM-H2DCFDA), mitochondrial membrane potential (JC10), level of ATP (CellTiter-Glo®) have been analysed using plate reader. Amount of mtDNA has been estimated by quantitative PCR. The level of individual subunits of oxidative phosphorylation system (OXPHOS) and the level of antioxidant enzymes (like: catalase, GR, GPX, SOD1, SOD2) have been determined by Western Blot. To outline the profile of mitochondrial abnormalities found in HD fibroblasts, evaluation of the progress of these changes with the development of the disease has been conducted. Results Our results indicate alterations in mitochondrial bioenergetics resulting in lower ATP level in HD fibroblasts. Although the other measured factors show only small alterations comparing to the control values. Created profile of mitochondrial abnormalities characteristic for HD cells shows that the most significant changes in analysed factors are observed at the early stage of the disease. Conclusions Our studies have shown that the changes in mitochondrial bioenergetics and function may be an important factor especially at the early state of the disease. This project was funded by the Polish National Science Centre, UMO- 2015/17/N/NZ2/04267 for PJ and UMO-2014/15/B/NZ1/00490 for MRW