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Query: UMLS:C0030567 (
Parkinson's disease
)
63,064
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In most neurodegenerative disorders, including multiple sclerosis,
Parkinson's disease
, and Alzheimer's disease, a massive neuronal cell death occurs as a consequence of an uncontrolled inflammatory response, where activated microglia and its cytotoxic agents play a crucial pathologic role. Because current treatments for these diseases are not effective, several regulatory molecules termed "microglia-deactivating factors" recently have been the focus of considerable research. Vasoactive intestinal peptide (VIP) is a neuropeptide with a potent anti-inflammatory effect, which has been found to protect from other inflammatory disorders, such as endotoxic shock and rheumatoid arthritis. In the present study, we investigate the effect of VIP on inflammation-mediated neurodegeneration in vitro and in vivo as well as on the putative neuroprotective effect of VIP on experimental pathological conditions in which central nervous system (CNS) inflammation is involved, such as brain trauma. The involvement of activated microglia and their derived cytotoxic products is also studied. VIP has a clear neuroprotective effect on inflammatory conditions by inhibiting the production of microglia-derived proinflammatory factors (
tumor necrosis factor alpha
, interleukin-1beta, nitric oxide). In this sense, VIP prevents neuronal cell death following brain trauma by reducing the inflammatory response of neighboring microglia. Therefore, VIP emerges as a valuable neuroprotective agent for the treatment of pathologic conditions of the CNS where inflammation-induced neurodegeneration occurs.
...
PMID:Vasoactive intestinal peptide prevents activated microglia-induced neurodegeneration under inflammatory conditions: potential therapeutic role in brain trauma. 1292 64
Serum levels of interferon-gamma (IF gamma),
tumor necrosis factor alpha
(TNF alpha) and autoantibodies (a-AT) to these cytokines were investigated in patients with
Parkinson's disease
(PD). The increased levels of TNF alpha (50%) and IF gamma (35%) were found in PD patients. There was close correlation between the serum level of TNF alpha and the manifestation of neurological symptoms (r = 0.434; p < 0.05), and between levels of IF gamma and the duration of this disease (r = 0.4511, p < 0.05) and patients age as well (r = 0.4358; p < 0.05). There was increased level of a-AT to TNF alpha in PD patients versus healthy controls (130.3 +/- 11.92 and 105.3 +/- 4.62, respectively, p < 0.05). The combined increase of levels of a-AT to TNF alpha and IF gamma (r = 0.91, p < 0.01) close reverse correlation between duration of PD and levels of a-AT to TNF alpha and IF gamma (r = 0.4644 and r = 0.606, respectively, p < 0.01) were also recognised. The data obtained suggest the involvement of TNF alpha and IF gamma into the pathological process during PD, which requires further investigation in this direction.
...
PMID:[Level of interferon-gamma, tumor necrosis factor alpha, and antibodies to them in blood serum from Parkinson disease patients]. 1456 85
Parkinson's disease
is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra. We have previously reported that lipopolysaccharide (LPS)-induced degeneration of dopaminergic neurons is mediated by the release of proinflammatory factors from activated microglia. Here, we report the pivotal role of NADPH oxidase in inflammation-mediated neurotoxicity, where the LPS-induced loss of nigral dopaminergic neurons in vivo was significantly less pronounced in NADPH oxidase-deficient (PHOX-/-) mice when compared with control (PHOX+/+) mice. Dopaminergic neurons in primary mensencephalic neuron-glia cultures from PHOX+/+ mice were significantly more sensitive to LPS-induced neurotoxicity in vitro when compared with PHOX-/- mice. Further, PHOX+/+ neuron-glia cultures chemically depleted of microglia failed to show dopaminergic neurotoxicity with the addition of LPS. Neuron-enriched cultures from both PHOX+/+ mice and PHOX-/- mice also failed to show any direct LPS-induced dopaminergic neurotoxicity. However, the addition of PHOX+/+ microglia to neuron-enriched cultures from either strain resulted in reinstatement of LPS-induced dopaminergic neurotoxicity, supporting the role of microglia as the primary source of NADPH oxidase-generated insult and neurotoxicity. Immunostaining for F4/80 in mensencephalic neuron-glia cultures revealed that PHOX-/- microglia failed to show activated morphology at 10 h, suggesting an important role of reactive oxygen species (ROS) generated from NADPH oxidase in the early activation of microglia. LPS also failed to elicit extracellular superoxide and produced low levels of intracellular ROS in microglia-enriched cultures from PHOX-/- mice. Gene expression and release of
tumor necrosis factor alpha
was much lower in PHOX-/- mice than in control PHOX+/+ mice. Together, these results demonstrate the dual neurotoxic functions of microglial NADPH oxidase: 1) the production of extracellular ROS that is toxic to dopamine neurons and 2) the amplification of proinflammatory gene expression and associated neurotoxicity.
...
PMID:NADPH oxidase mediates lipopolysaccharide-induced neurotoxicity and proinflammatory gene expression in activated microglia. 1457 53
We previously reported that injection of the Gram (-) bacteriotoxin, lipopolysaccharide (LPS), into gravid females at embryonic day 10.5 led to the birth of animals with fewer than normal dopamine (DA) neurons when assessed at postnatal days (P) 10 and 21. To determine if these changes continued into adulthood, we have now assessed animals at P120. As part of the previous studies, we also observed that the pro-inflammatory cytokine
tumor necrosis factor alpha
(TNFalpha) was elevated in the striatum, suggesting that these animals would be more susceptible to subsequent DA neurotoxin exposure. In order to test this hypothesis, we injected (at P99) 6-hydroxydopamine (6OHDA) or saline into animals exposed to LPS or saline prenatally. The results showed that animals exposed to prenatal LPS or postnatal 6OHDA alone had 33% and 46%, respectively, fewer DA neurons than controls, while the two toxins combined produced a less than additive 62% loss. Alterations in striatal DA were similar to, and significantly correlated with (r(2)=0.833) the DA cell losses. Prenatal LPS produced a 31% increase in striatal TNFalpha, and combined exposure with 6OHDA led to an 82% increase. We conclude that prenatal exposure to LPS produces a long-lived THir cell loss that is accompanied by an inflammatory state that leads to further DA neuron loss following subsequent neurotoxin exposure. The results suggest that individuals exposed to LPS prenatally, as might occur had their mother had bacterial vaginosis, would be at increased risk for
Parkinson's disease
.
...
PMID:Combined toxicity of prenatal bacterial endotoxin exposure and postnatal 6-hydroxydopamine in the adult rat midbrain. 1498 Jul 32
Parkinson's disease
(PD) is one of the most prevalent neurodegenerative disorders and is characterized by the progressive loss of dopamine neurons in the substantia nigra. There is increasing evidence to suggest the inflammatory response of the brain contributes to the pathogenesis of PD. This study investigated the frequency of polymorphism located in the critical promoter region of the proinflammatory cytokine genes: interleukin (IL)-2, IL-6, IL-8, and
tumor necrosis factor alpha
(
TNF-alpha
) within a cohort of patients with PD in comparison to a group of healthy elderly individuals. No association was observed for single nucleotide polymorphism in the promoter regions of the IL-2, IL-6, and
TNF-alpha
genes. The single nucleotide polymorphism in the chemokine IL-8 gene was observed to associate with PD and appeared to be independent of age at onset. This association further supports the theory that the proinflammatory response in the brains of patients with PD plays a role in the pathogenesis of the disease and warrants further investigation into the role of chemokines in the brain, and a more detailed analysis of the genetics involved in the immune response of the brain.
...
PMID:Functional promoter region polymorphism of the proinflammatory chemokine IL-8 gene associates with Parkinson's disease in the Irish. 1512 Jan 88
6-Hydroxydopamine (6-OHDA) is widely used to study the death of catecholaminergic cells related to
Parkinson's disease
. Oxidative stress and gene transcription are known to mediate the pro-apoptotic effect of 6-OHDA. As redox mechanisms are involved in activation of the transcription factor NF-kappaB, we studied the role of NF-kappaB in 6-OHDA-induced death of PC12 cells. We stably transfected PC12 cells with a doxycycline-regulated expression vector for the NF-kappaB super-repressor (IkappaBalpha mutated at serine-32 and serine-36, IkappaBalpha-SR). NF-kappaB transcriptional activity was evaluated by transient transfection of an NF-kappaB-driven luciferase reporter gene. Expression of IkappaBalpha-SR inhibited NF-kappaB stimulated by
tumor necrosis factor alpha
(TNFalpha) and 6-OHDA. Apoptosis was quantified by counting cells with condensed nuclei. IkappaBalpha-SR inhibited apoptosis induced by 6-OHDA but enhanced apoptosis that was triggered by TNFalpha. The converse effects of NF-kappaB could be due to different target genes that are induced in the context of TNFalpha and 6-OHDA stimulation. Indeed, TNFalpha stimulated mRNA accumulation of the anti-apoptotic superoxide dismutase 2 through NF-kappaB whereas 6-OHDA induced mRNA accumulation of the pro-apoptotic c-myc. These data demonstrate that NF-kappaB regulates survival of the neuron-like PC12 cells in a stimulus-specific manner. In the context of 6-OHDA stimulation, NF-kappaB mediates pro-apoptotic effects, suggesting that NF-kappaB signaling could be a target for drug development in Parkinson-related neurodegeneration.
...
PMID:The role of NF-kappaB in 6-hydroxydopamine- and TNFalpha-induced apoptosis of PC12 cells. 1514 32
We previously demonstrated that treating gravid female rats with the bacteriotoxin lipopolysaccharide (LPS) led to the birth of offspring with fewer than normal dopamine (DA) neurons. This DA neuron loss was long-lived and associated with permanent increases in the pro-inflammatory cytokine
tumor necrosis factor alpha
(TNFalpha). Because of this pro-inflammatory state, we hypothesized that these animals would be more susceptible to subsequent exposure of DA neurotoxins. We tested this hypothesis by treating female Sprague-Dawley rats exposed to LPS or saline prenatally with a subtoxic dose of the DA neurotoxin rotenone (1.25 mg/kg per day) or vehicle for 14 days when they were 16 months old. After another 14 days, the animals were sacrificed. Tyrosine hydroxylase-immunoreactive (THir) cell counts were used as an index of DA neuron survival. Animals exposed to LPS prenatally or rotenone postnatally exhibited a 22% and 3%, respectively, decrease in THir cell counts relative to controls. The combined effects of prenatal LPS and postnatal rotenone exposure produced a synergistic 39% THir cell loss relative to controls. This loss was associated with decreased striatal DA and increased striatal DA activity ([HVA]/[DA]) and TNFalpha. Animals exposed to LPS prenatally exhibited a marked increase in the number of reactive microglia that was further increased by rotenone exposure. Prenatal LPS exposure also led to increased levels of oxidized proteins and the formation of alpha-Synuclein and eosin positive inclusions resembling Lewy bodies. These results suggest that exposure to low doses of an environmental neurotoxin like rotenone can produce synergistic DA neuron losses in animals with a preexisting pro-inflammatory state. This supports the notion that
Parkinson's disease
(PD) may be caused by multiple factors and the result of "multiple hits" from environmental toxins.
...
PMID:Rotenone potentiates dopamine neuron loss in animals exposed to lipopolysaccharide prenatally. 1553 Aug 76
Inflammatory processes are thought to underlie the dopamine (DA) neuron loss seen in
Parkinson's disease
(PD). However, it is not known if the inflammation precedes that loss, or is a consequence of it. We injected
tumor necrosis factor alpha
(TNFalpha) and interleukin 1 beta (IL-1beta) into the median forebrain bundle to determine if these pro-inflammatory cytokines could induce DA neuron loss in the substantia nigra (SN) by themselves. The magnitude of the DA cell loss as well as the decreases in striatal DA, were both dose and time to sacrifice dependent. Injecting both cytokines together produced greater cell losses and DA reductions than that seen when the cytokines were injected alone. The DA neuron loss seen was more pronounced in the lateral nigra and its ventral tier and similar to that seen when other toxins are injected. These data suggest that TNFalpha and IL-1beta can induce DA neuron loss by themselves and could produce DA neuron loss independent of other inflammatory events.
...
PMID:Intra-parenchymal injection of tumor necrosis factor-alpha and interleukin 1-beta produces dopamine neuron loss in the rat. 1558 62
The purpose of this study was to develop a novel therapy for
Parkinson's disease
(PD). We recently reported that dextromethorphan (DM), an active ingredient in a variety of widely used anticough remedies, protected dopaminergic neurons in rat primary mesencephalic neuron-glia cultures against lipopolysaccharide (LPS)-mediated degeneration and provided potent protection for dopaminergic neurons in a MPTP mouse model. The underlying mechanism for the protective effect of DM was attributed to its anti-inflammatory activity through inhibition of microglia activation. In an effort to develop more potent compounds for the treatment of PD, we have screened a series of analogs of DM, and 3-hydroxymorphinan (3-HM) emerged as a promising candidate for this purpose. Our study using primary mesencephalic neuron-glia cultures showed that 3-HM provided more potent neuroprotection against LPS-induced dopaminergic neurotoxicity than its parent compound. The higher potency of 3-HM was attributed to its neurotrophic effect in addition to the anti-inflammatory effect shared by both DM and 3-HM. First, we showed that 3-HM exerted potent neuroprotective and neurotrophic effects on dopaminergic neurons in rat primary mesencephalic neuron-glia cultures treated with LPS. The neurotrophic effect of 3-HM was glia-dependent since 3-HM failed to show any protective effect in the neuron-enriched cultures. We subsequently demonstrated that it was the astroglia, not the microglia, that contributed to the neurotrophic effect of 3-HM. This conclusion was based on the reconstitution studies, in which we added different percentages of microglia (10-20%) or astroglia (40-50%) back to the neuron-enriched cultures and found that 3-HM was neurotrophic after the addition of astroglia, but not microglia. Furthermore, 3-HM-treated astroglia-derived conditioned media exerted a significant neurotrophic effect on dopaminergic neurons. It appeared likely that 3-HM caused the release of neurotrophic factor(s) from astroglia, which in turn was responsible for the neurotrophic effect. Second, the anti-inflammatory mechanism was also important for the neuroprotective activity of 3-HM because the more microglia were added back to the neuron-enriched cultures, the more significant neuroprotective effect was observed. The anti-inflammatory mechanism of 3-HM was attributed to its inhibition of LPS-induced production of an array of pro-inflammatory and neurotoxic factors, including nitric oxide (NO),
tumor necrosis factor alpha
(
TNF-alpha
), prostaglandin E2 (PGE2) and reactive oxygen species (ROS). In conclusion, this study showed that 3-HM exerted potent neuroprotection by acting on two different targets: a neurotrophic effect mediated by astroglia and an anti-inflammatory effect mediated by the inhibition of microglial activation. 3-HM thus possesses these two important features necessary for an effective neuroprotective agent. In view of the well-documented very low toxicity of DM and its analogs, this report may provide an important new direction for the development of therapeutic interventions for inflammation-related diseases such as PD.
...
PMID:3-hydroxymorphinan is neurotrophic to dopaminergic neurons and is also neuroprotective against LPS-induced neurotoxicity. 1559 82
Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative human brain disorders. We sought to investigate molecular signaling mechanisms that govern activation of microglia in apoptotic neuronal degeneration. We report here that the active form of matrix metalloproteinase-3 (MMP-3) was released into the serum-deprived media (SDM) of PC12 cells and other media of apoptotic neuronal cells within 2-6 h of treatment of the cells, and SDM and catalytic domain of recombinant MMP-3 (cMMP-3) activated microglia in primary microglia cultures as well as BV2 cells, a mouse microglia cell line. Both SDM and cMMP-3 induced generation of
tumor necrosis factor alpha
(
TNF-alpha
), interleukin-6 (IL-6), IL-1beta, and interleukin-1 receptor antagonist but not IL-12 and inducible nitric oxide synthase, which are readily induced by lipopolysaccharide, in microglia, suggesting that there is a characteristic pattern of microglial cytokine induction by apoptotic neurons. Neither glial cell line-derived neurotrophic factor nor anti-inflammatory cytokines, such as IL-10 and transforming growth factor-beta1, were induced. SDM and cMMP-3 extensively released
TNF-alpha
from microglia and activated the nuclear factor-kappaB pathway, and these microglial responses were totally abolished by preincubation with an MMP-3 inhibitor, NNGH [N-isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid]. MMP-3-mediated microglial activation mostly depended on ERK (extracellular signal-regulated kinase) phosphorylation but not much on either JNK (c-Jun N-terminal protein kinase) or p38 activation. Conditioned medium of SDM- or cMMP-3-activated BV2 cells caused apoptosis of PC12 cells. These results strongly suggest that the distinctive signal of neuronal apoptosis is the release of active form of MMP-3 that activates microglia and subsequently exacerbates neuronal degeneration. Therefore, the release of MMP-3 from apoptotic neurons may play a major role in degenerative human brain disorders, such as
Parkinson's disease
.
...
PMID:Matrix metalloproteinase-3: a novel signaling proteinase from apoptotic neuronal cells that activates microglia. 1581 1
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