Browsing by Subject "C9ORF72"

Amyotrophic lateral sclerosis (ALS) is a rare fatal neurodegenerative disease in which both the upper and lower motor neurons degenerate. Pathological features of the disease include misfolded proteins and accumulations in the central nervous system. The molecular mechanisms of the disease include neuroinflammation, glutamate induced excitotoxicity, and endoplasmic reticulum stress (ER-stress). Numerous genetic defects have been identified in the background of ALS, the most common mutations are in the C9ORF72, SOD1, TDP43 and FUS genes. For each gene mutation, it is important to develop a reliable animal model of ALS for studying pathology and testing new therapies. The most common and most recently found gene mutation, the C9ORF72 repeat expansion mutation, does not yet have an established animal disesase model. The molecular mechanisms of the disease include neuroinflammation, glutamate induced excitotoxicity, and endoplasmic reticulum stress (ER- stress). There is no drug treatment to cure or slow ALS, so the need for new drug therapies that affect the course of the disease is significant. Cerebral dopamine neurotrophic factor (CDNF) protects and restores dopamine neurons and controls ER-stress in preclinical models of Parkinson’s disease. CDNF has also been shown to improve motor coordination as well as protect spinal cord neurons from cell destruction in ALS genetic SOD1- G93A mouse and TDP-43M337 animal models. The purpose of this master's thesis study was to characterize the changes related to neurodegeneration and neuroinflammation in the new C9ORF72-500 disease model and study ER stress of the SOD1-93A disease model and the effect of CDNF on ER stress in SOD1-model and on inflammation in C9-model. In the first sub-study, brain sections from C9ORF72 transgenic and wild-type mice at different time points were subjected to six different immunohistological stainings. The results were compared at each time point (30, 70 and 170) between the wild type and the transgenic group. In another sub-study, spinal cord sections from CDNF snd vehicle treated SOD1- G93A mice were subjected to immunofluorescence staining, after which the intensity of their ER stress marker, GRP78, was analyzed using a confocal microscope. GFAP stained brain sections from CDNF and vehicle treated C9ORF72 mice were analyzed using microscope and imaging analyses. The results of the first sub-study showed neuroinflammation at 24 weeks timepoint in the transgenic group compared to wild-type mice. Pathological features of C9-ALS, various protein accumulations, were observed only in the transgenic group, mainly at 24 weeks. No neuronal loss was observed in this study. The obtained results support the previously published research results and support the reliability of the studied disease model. In the second sub-study ER stress levels were higher in SOD1-mice compared to wild-type mice. Single intracerebroventrical CDNF injection reduced ER stress in SOD1-G93A transgenic mice almost to the same level as ER stress in wild-type mice. CDNF treatment also showed a tendency for reducing inflammation in hippocampus and motor cortex of C9ORF72 mice. The results confirm the pathological role of ER stress in ALS and show that CDNF reduces ER stress when administered as early in the disease as possible, when neuronal damage begins to occur but does not yet lead to neuronal destruction. CDNF appears to be a promising drug candidate for the treatment of ALS and should therefore be further investigated.