| Parkinson's disease (PD) is a common nerve degenerative disease. It has been reported that microglia mediated inflammatory reaction in brain play a key role in causeing degeneration of substantia nigra dopaminergic neuron. Microglia is the immunoreaction cell of central nervous system, and activated microglia has protective effect on neuron, but the overavtivity microglia may cause serious neurotoxicity.polyunsaturated fatty acids (PUFAs) have extensive functions in biosystem. Many studies have shown that n-3 PUFAs had many kinds of effects, such as the protection of angiocardiopathy, anti-inflammation, antioxidation and the inhibitory effect on apoptosis apoptosis. Recent studies considered that n-3 PUFASs had important effect on the protection of central nervous system, which may be associated with anti-inflammatory effect of n-3 PUFAs. EPA and DHA can decrease I-κB phosphorylation, which contributes to the inhibition of the expression of NF-κB and other inflammatory cytokines induced by LPS. LPS is effective constituent in Gram-negative bacteria cell toxin. It is a strong proinflammatory factor, and can induce inflammatory reaction of organism.SD adult male rats were used to establish the Parkinson's disease animal model of LPS by stereotaxic surgery in the present study. The effect of microglia cell-activating induced by inflammatory reaction and its role in the development of PD were investigated. We further observed the protective effect of PUFASs on PD.Methods1. Brain stereotactic surgery injection. Fourteen days after injection of different concentrations of LPS(2.5μg,5μg), apomorphine was injected through intraperitoneal, and behavioral changes of the rats were observed to estimate the successful animal model. The density of the dopaminergic neurons and the activation of microglial cells were detected by immunofluorescence fluorescein stain.2. With pre-injection of PDTC, the activation of microglia OX-42 and NF-κB p65 were observed by immunofluorescence fluorescein stain. The protein expression of NF-κB p65 was detected by Western blot.3. The animals were divided into NS control group , LPS control group, 30% fish oils group, and 60% fish oils group. in each group, ethology variation were measured after apomorphine injection. The number of TH positive cells and the activation of microglia OX-42 were detected by immunofluorescence fluorescein stain. The protein expression of TH and NF-κB p65 were detected by Western blot. Results1. Fourteen days after LPS injection by brain stereotactic surgery in rats brain substantia nigra, apomorphine was administrated through intraperitoneal injection. NS control group has no obvious abnormal behavior, the rotation turns to the injection side of two LPS groups was significantly more than NS group(P<0.05). With immunofluorescence detection, the number of TH positive cells of LPS 2.5μg group and 5μg group were significantly decreased compare to the NS group, the most significant reduction was in LPS 5μg group. A few microglia cells body in LPS 2.5μg group become lager, and apophysis become coarsen, but in LPS 5μg group, the number of activated microglial cells obviously increased, cell body become lager and more stainable, and apophysis become coarsen.2. 14 d after LPS injection, through intraperitoneal injection APO, rotation turns of PDTC treatment group were significantly less than LPS group, immunofluorescence detection results show that a few microglia cell body become lager, and apophysis become coarsen in PDTC group. Compare with the PDTC group, number of activated microglial cells in LPS group was significantly increases, cell body become lager and more stainable, and apophysis become coarsen. Western blot detection results shown that, the protein expression of NF-κB p65 was no significant difference between NS group and PDTC group. The protein expression of NF-κB p65 was significantly increased in LPS group(P<0.05).3. NS group has no obvious behavior changes after APO injection, LPS group rotated to the injection side, and accompanied by obvious forelimb trembler. The rotation turns of 30% fish oil group and 60% fish oil group were obvious less than the LPS group (P<0.05) after APO induction. Immunofluorescence detection TH results show that,compared with NS group, the number of TH positive cells in 30% fish oil group and 60% fish oil group were no significantly difference. The number of TH positive cells in LPS group was decreased(P<0.05). With immunofluorescence fluorescein stain detection activation of microglia, we found that the number of activated microglial cells in two fish oil groups, the number of activated microglial cells in LPS group was significantly increased compare to the NS group. Western blot detection of TH proteins level shown that the protein expression of TH was no obvious difference in two fish oils groups. But the protein expression of TH was significantly reduced in LPS group(P<0.05)compare to the NS group; The protein expression of NF-κB p65 in two fish oil groups were no obvious difference. The protein expression of NF-κB p65 in the LPS group was significantly higher than NS group(P<0.05).Conclusions1. Injection LPS in substantia nigra activated microglia and induced dopaminergic neuron injury.2. LPS increased the expression of NF-κB p65 , and PDTC can inhibit the expression of NF-κB p65.3. Dietary Supplement fish oil had protective effect on DA neuron injury induced by LPS, which may be associated with the inhibition of microglia activation and reduction of the expression of NF-κB.
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