Mapping of genes, which modify susceptibility to Leishmania major infection

Katedra fyziol. živočichů a vývoj. biol. (zrušena)Dep. of Physiology and Develop. Biology (obsolete)Přírodovědecká fakultaFaculty of Scienc

Mitochondrial structure and energetic metabolism changes in patients with Huntington's disease and in transgenic minipig model

Huntington's disease (HD) is a severe neurodegenerative disease with autosomal dominant inheritance. HD is caused by the expansion of the CAG triplet in the gene for the huntingtin protein (Htt), which leads to damage and loss of its functions. Htt is essential in the development of the nervous system, it is involved in axonal transport, regulation of mitochondrial metabolism gene expression or spermiogenesis. In HD, the nerve tissue is most significantly damaged, but pathological changes associated with the disease are detected throughout the organism. There is currently no satisfactory treatment. Mitochondrial damage has been shown to significantly affect the progression of HD in patients with HD, but the mechanisms of mitopathy and its development with all the effects on tissue physiology in HD are still not fully understood. The aim of the dissertation theses was to study mitochondrial energy metabolism impairment, mitochondrial network organization and mitochondrial ultrastructure in HD in selected tissues of patients with HD and in a minipig model transgenic for HD (TgHD). Furthermore, the effort was to find and characterize a mitochondrial biomarker of HD, which would well reflect the patient's current clinical phenotype state and it would be possible to monitor changes in its parameters..

Mapping of genes, which modify susceptibility to Leishmania major infection

Katedra fyziol. živočichů a vývoj. biol. (zrušena)Dep. of Physiology and Develop. Biology (obsolete)Přírodovědecká fakultaFaculty of Scienc

Mitochondrial translation is the primary determinant of secondary mitochondrial complex I deficiencies

Summary: Individual complexes of the mitochondrial oxidative phosphorylation system (OXPHOS) are not linked solely by their function; they also share dependencies at the maintenance/assembly level, where one complex depends on the presence of a different individual complex. Despite the relevance of this “interdependence” behavior for mitochondrial diseases, its true nature remains elusive. To understand the mechanism that can explain this phenomenon, we examined the consequences of the aberration of different OXPHOS complexes in human cells. We demonstrate here that the complete disruption of each of the OXPHOS complexes resulted in a decrease in the complex I (cI) level and that the major reason for this is linked to the downregulation of mitochondrial ribosomal proteins. We conclude that the secondary cI defect is due to mitochondrial protein synthesis attenuation, while the responsible signaling pathways could differ based on the origin of the OXPHOS defect

Mitochondrial Dysfunction in a High Intraocular Pressure-Induced Retinal Ischemia Minipig Model

Purpose: Retinal ischemia (RI) and progressive neuronal death are sight-threatening conditions. Mitochondrial (mt) dysfunction and fusion/fission processes have been suggested to play a role in the pathophysiology of RI. This study focuses on changes in the mt parameters of the neuroretina, retinal pigment epithelium (RPE) and choroid in a porcine high intraocular pressure (IOP)-induced RI minipig model. Methods: In one eye, an acute IOP elevation was induced in minipigs and compared to the other control eye. Activity and amount of respiratory chain complexes (RCC) were analyzed by spectrophotometry and Western blot, respectively. The coenzyme Q10 (CoQ10) content was measured using HPLC, and the ultrastructure of the mt was studied via transmission electron microscopy. The expression of selected mt-pathway genes was determined by RT-PCR. Results: At a functional level, increased RCC I activity and decreased total CoQ10 content were found in RPE cells. At a protein level, CORE2, a subunit of RCC III, and DRP1, was significantly decreased in the neuroretina. Drp1 and Opa1, protein-encoding genes responsible for mt quality control, were decreased in most of the samples from the RPE and neuroretina. Conclusions: The eyes of the minipig can be considered a potential RI model to study mt dysfunction in this disease. Strategies targeting mt protection may provide a promising way to delay the acute damage and onset of RI