Browsing by Subject "neuroprotection"
Now showing items 1-3 of 3
-
(2015)Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease affecting motor neurons. It finally leads to the malfunction of the respiratory muscles and death after 1-3 years of diagnosis. Sporadic cases of ALS cover 90-95% of all patients and familial 5-10% respectively. The onset of the disease is usually between age of 40 and 60 and the worldwide incidence is considered to be 1-2/100000. Currently discovered cerebral dopamine neurotrophic factor, CDNF, has showed neuroprotective effects on Parkinson's disease model. What is more, it is known that CDNF is expressed in the muscles of mice and one of its' main functions is to protect cells from ER-stress, one of the pathological mechanisms in ALS. Hence, it is rational to study the effects of CDNF in ALS mouse model. Treatment options are needed, since there is only one approved treatment for ALS, anti-glutaminergic rilutzole. The aim of this study was to find out whether CDNF shows neuroprotective effects in SOD1-mice e.g. by measuring the changes in motor function with different behavioral tests. More over, the distribution of CDNF after intrathecal ventricle injection was studied using immunohistochemical and radioactive labeling methods. The hypothesis was that CDNF is distributed through the cerebrospinal fluid into the spinal cord and muscles in the limbs and shows neuroprotective effects in this SOD1 mouse model.
-
(2013)Laminins are a family of heterotrimeric glycoproteins found mainly in basement membranes. They interact with numerous other extracellular matrix components and cell surface receptors, including integrins and α-dystroglycan. Laminins play roles in myriad of functions including tissue morphogenesis, organogenesis, maintenance of tissue integrity and compartmentalization. In central nervous system laminins are involved in every major developmental stage from neural tube closure to synaptogenesis. Laminin expression in central nervous system decreases after maturation but has been found inducible by injury after trauma or disease. Since laminins are known to promote neurite outgrowth and neuronal survival, this has been proposed as a regenerative response to injury. Although the effects of endogenous laminin are clearly inadequate for repair, laminin based compounds could be powerful therapeutic agents. In previous in vivo studies KDI-tripeptide, a neurite outgrowth promoting fragment from γ1-laminin, has proved effective neuroprotective and regeneration promoting compound. Encouraged by these results I set out to test whether KDI would rescue midbrain dopaminergic neurons in unilateral 6-hydroxydopamine-induced rat model of Parkinson's disease. KDI (1-30µg) was injected to the striatum six hours prior to 6-hydroxydopamine. The severity of the lesion was then evaluated by measuring D-amphetamine induced rotation 2, 4 and 6 weeks postlesion and by assessing the number of neurons in substantia nigra pars compacta and optical density of striatum after tyrosine hydroxylase immunostaining at week seven. The only effective KDI dose studied was 3 µg. Compared to control it decreased Damphetamine induced rotational behaviour significantly at week four. KDI, however, failed to save tyrosine hydroxylase positive dopaminergic neurons in substantia nigra pars compacta or their axons in striatum. KDI might be usable in treating Parkinson's disease but it's mode of action doesn't appear to rely on protecting dopaminergic neurons or promoting the branching of their axons. KDI is known to inhibit ionotropic glutamate receptors and could therefore improve motor function by opposing striatal denervation induced overactivity of glutamatergic subthalamic nucleus neurons.
-
(2012)Parkinson's disease is a progressive degenerative brain disease that causes degeneration of dopaminergic neurons in the substantia nigra. Characteristic motor symptoms in Parkinson's disease are caused by dopamine deficiency in striatum. Tyrosine hydroxylase (TH) is the enzyme that catalyzes the rate-limiting step in the dopamine biosynthesis. Because of this TH has a significant role in the function of the dopaminergic system. TH activity is regulated by several mechanisms. The most important regulatory mechanism is phosphorylation of TH protein by spesific protein kinases. Alterations in the function of TH have been associated with Parkinson's disease. The most prominent findings are decreased TH protein and TH mRNA content in the nigrostriatal dopaminergic neurons. A possible pathogenic role of TH in Parkinson's disease has also been suggested. In addition TH might be a potential therapeutic protein for gene therapy. One possible approach is viral vector-mediated gene transfer of TH gene directly into the brain. Simultaneous gene transfer of TH gene and neurotrophic factor gene could both enhance dopamine synthesis and prevent remaining dopaminergic neurons from dying. None of the current treatments of Parkinson's disease can halt or retard dopaminergic neuron degeneration. Novel treatments are being developed and amongst other strategies neurotrophic factors have proven promising candidates for the treatment of Parkinson's disease. Member of CDNF/MANF family of neurotrophic factors, cerebral dopamine neurotrophic factor (CDNF), is currently being studied. Previous studies have demonstrated the neuroprotective and neurorestorative effects of CDNF but more research is needed for optimal administration technique and dose. The aim of this work was to study the neuroprotective effect of AAV vector-mediated delivery of CDNF (AAV-CDNF) in a rat model of Parkinson's disease. Rats' brains were unilaterally lesioned with intrastriatal injection of 6-OHDA two weeks after viral vector injections and amphetamine-induced rotational behavior was monitored for ten weeks. The CDNF protein expression after intrastriatal AAV vector-mediated gene transfer was analyzed with immunohistochemical staining of brain sections. We confirmed that CDNF protein is expressed in rat brain after intrastriatal injection of AAV-CDNF. AAV-CDNF treatment also reduced the amphetamineinduced ipsilateral rotations nearly as much as AAV-GDNF treatment. AAV-CDNF treatment also had an effect on the amount of remaining TH-immunoreactive cells in the substantia nigra pars compacta and the optical density of striatal TH-immunoreactive fibers but these results did not reach statistical significance. The immunohistochemical measures did not correlate completely with the behavioral data and further studies are needed to confirm the results obtained here. The results of this research support the conclusion that AAV-CDNF treatment has a neuroprotective effect on nigrostriatal dopaminergic neurons.
Now showing items 1-3 of 3