Dissertation > Excellent graduate degree dissertation topics show

Experimental Study of Iron-induced Alpha-synuclein Aggregation in the Pathogenesis of Parkinson’s Disease

Author: HeQing
Tutor: JiangHong；XieJunXia
School: Qingdao University
Course: Physiology
Keywords: Iron alpha- synuclein HO-1 Nrf2 Parkinson's disease
CLC: R742.5
Type: Master's thesis
Year: 2010
Downloads: 68
Quote: 1
Read: Download Dissertation

Abstract

Parkinson's disease (Parkinson's disease, PD) is the second Alzheimer's disease is the second largest neurodegenerative diseases. In China, over 65 people with Parkinson's disease prevalence was 1.7%. PD neuropathological basis of the substantia nigra (substantia nigra, SN) compacta dopamine (dopamine, DA) neurons degeneration demyelination and thus lead to striatal DA content decreased. Parkinson's disease is characterized by pathological structures Lewy bodies, whose main ingredient is aggregated alpha-synuclein, in addition to iron, proteasome subunit, ubiquitin, heat shock protein and other ingredients. In familial or sporadic Parkinson's disease, the substantia nigra within the alpha-synuclein mRNA levels were increased. These results suggest that alpha-synuclein and the Lewy body of the component interactions may be involved in the dopaminergic neurons selective death. More and more evidence that the iron in the pathogenesis of PD is a key factor, PD patients black transformative neurons were found in iron content increased with Lewy body formation. Recent years, people found to rail were able to to promote the alpha-synapse nucleoprotein's aggregation, but the specific mechanisms Huan unclear. Heme plus oxygen enzyme -1 (Heme oxygenase-1, HO-1) as a thermal shock protein 32, there exists Yu Louis Xiao Ti medium. Recent studies have found that cells overexpressing HO-1 through activation of ubiquitin - proteasome system and promote alpha-synuclein degradation. In the HO-1 gene coding region promoter memory activated protein -1 (activtor protein-1, AP-1) sequence, is called oxidative stress element (antioxidant responses elements, ARE), which can be a redox activity of nuclear factor (NF-E2-regulated factor 2, Nrf2) precision adjustment. Has proved Nrf2/HO-1 pathway is an intracellular oxidative stress in an important way. So in the iron induced alpha-synuclein aggregation process if there Nrf2/HO-1 pathways involved in it? In this experiment, we use Fe3 or Fe2 redox active role in SK-N-SH cells, the use of methyl thiazolyl four azole (methyl thiazolyl tetrazolium, MTT) Legalist, flow cytometry, PCR, small interfering RNA, Thioflavin S staining as well as electron microscopy, etc. techniques to explore the iron lead to alpha-synapse nucleoprotein the aggregation of and its toxic reaction mechanism. The results showed that: 1. Cells overexpressing alpha-synuclein on SK-N-SH cell viability had no significant effect, while interfering off alpha-synuclein after 48h cell viability decreased by 10%. Compared with control group, the over-expression of alpha-synuclein in cells, Fe3 (100μmol / L, 500μmol / L, 1 mmol / L, 10 mmol / L) were incubated 24 h further increased the intracellular iron resulting from cell survival rate decreased, while the same concentration of Fe3 incubated for interferometer swaps alpha-synapses nucleoprotein's cell allow blocking survival rate of of decline. 2.Fe2 (100μmol / L) were incubated over-expression of alpha-synuclein in SK-N-SH cells 4h or Fe3 (100μmol / L, 1 mmol / L) incubated for 24 h, compared with control group, mitochondrial transmembrane potential difference (mitochondrial transmembrane potential, AΔΨm) the decline in and active oxygen substances (reactive oxygen species, ROS) generate the increase in is more obvious, while the the same concentration of Fe2 or Fe3 incubated for interfere in swaps alpha-synapses nucleoprotein's cell then the Recoverable ΔΨm and inhibition of ROS 3.Fe2 (100μmol / L) were incubated over-expression of alpha-synuclein in SK-N-SH cells 4 h, can aggravate Fe2 induced apoptosis, compared with the control group showed ratio, Bcl-2 mRNA down-regulation is more obvious and electron microscopy to apoptotic bodies appear, and Fe2 incubation interference off alpha-synuclein cells does not appear apoptotic 4.Fe2 (100μmol / L) incubated expression of alpha-synuclein in SK-N-SH cells 4h or Fe3 (100μmol / L, 1 mmol / L) were incubated 24 h, cells apparent aggregation. Electron microscope together to form filaments and impaired mitochondrial swelling. The same concentration of Fe2 or Fe3 incubated interference off alpha-synuclein cells does not appear congregation. 5.Fe2 (100μmol / L) were incubated SK-N-SH cells 24 h can cause Nrf2 and HO-1 mRNA expression levels of the time-dependent changes. 6.Fe2 (100μmol / L) were incubated SK-N-SH cells 4h able to cut Nrf2 and HO-1 mRNA levels, intracellular overexpression of alpha-synuclein increased Nrf2 and HO-1 mRNA content decreased, while cell within the interferometer off alpha-synuclein will enable Nrf2 and HO-1 mRNA levels returned to normal levels. 7.SK-N-SH of intracellular over - expression HO-1 can promote alpha-synapse nucleoprotein mRNA degradation. These results indicate that iron can reduce cell ΔΨm, excessive ROS and apoptosis induced cytotoxicity. Meanwhile, the iron can be reduced Nrf2 and HO-1 mRNA expression levels of intracellular aggregation of alpha-synuclein, alpha-synuclein aggregation can be further aggravated Nrf2 and HO-1 mRNA levels decreased and realize their own further aggregation. Aggregated alpha-synuclein has further aggravated the iron toxicity to form a vicious cycle, eventually leading to cell death. This experiment for the intracerebral iron with the alpha-synapse nucleoprotein interaction injury in dopaminergic nerves yuan provides a new basis, and for the drug intervention to provide the possible role of targets.

Related Dissertations

CLC: > Medicine, health > Neurology and psychiatry > Neurology > Brain diseases > Paralysis agitans syndrome
© 2012 www.DissertationTopic.Net Mobile