| 1. |
- Kotsovolou, Olga, et al.
(författare)
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Hepatic drug metabolizing profile of Flinders Sensitive Line rat model of depression
- 2010
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Ingår i: Progress in Neuro-psychopharmacology and Biological Psychiatry. - : Elsevier BV. - 0278-5846 .- 1878-4216. ; 34:6, s. 1075-1084
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Forskningsöversikt (refereegranskat)abstract
- The Flinders Sensitive Line (FSL) rat model of depression exhibits some behavioral, neurochemical, and pharmacological features that have been reported in depressed patients and has been very effective in screening antidepressants. Major factor that determines the effectiveness and toxicity of a drug is the drug metabolizing capacity of the liver. Therefore, in order to discriminate possible differentiation in the hepatic drug metabolism between FSL rats and Sprague Dawley (SD) controls, their hepatic metabolic profile was investigated in this study. The data showed decreased glutathione (GSH) content and glutathione S-transferase (GST) activity and lower expression of certain major CYP enzymes, including the CYP2B1, CYP2C11 and CYP2D1 in FSL rats compared to SD controls. In contrast, p-nitrophenol hydroxylase (PNP), 7ethoxyresorufin-O-dealkylase (EROD) and 16 alpha-testosterone hydroxylase activities were higher in FSL rats. Interestingly, the wide spread environmental pollutant benzo(alpha)pyrene (B(alpha)P) induced CYP1A1, CYP1A2, CYP2B1/2 and ALDH3c at a lesser extend in FSL than in SD rats, whereas the antidepressant mirtazapine (MIRT) up-regulated CYP1A1/2, CYP2C11, CYP2D1, CYP2E1 and CYP3A1/2, mainly, in FSL rats. The drug also further increased ALDH3c whereas suppressed GSH content in B(a)P-exposed FSL rats. In conclusion, several key enzymes of the hepatic biotransformation machinery are differentially expressed in FSL than in SD rats, a condition that may influence the outcome of drug therapy. The MIRT-induced up-regulation of several drug-metabolizing enzymes indicates the critical role of antidepressant treatment that should be always taken into account in the designing of treatment and interpretation of insufficient pharmacotherapy or drug toxicity.
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| 2. |
- Xilouri, Maria, et al.
(författare)
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Boosting chaperone-mediated autophagy in vivo mitigates alpha-synuclein-induced neurodegeneration
- 2013
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Ingår i: Brain. - : Oxford University Press (OUP). - 1460-2156 .- 0006-8950. ; 136, s. 2130-2146
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Tidskriftsartikel (refereegranskat)abstract
- alpha-Synuclein levels are critical to Parkinson's disease pathogenesis. Wild-type alpha-synuclein is degraded partly by chaperone-mediated autophagy, and aberrant alpha-synuclein may act as an inhibitor of the pathway. To address whether the induction of chaperone-mediated autophagy may represent a potential therapy against alpha-synuclein-induced neurotoxicity, we overexpressed lysosomal-associated membrane protein 2a, the rate-limiting step of chaperone-mediated autophagy, in human neuroblastoma SH-SY5Y cells, rat primary cortical neurons in vitro, and nigral dopaminergic neurons in vivo. Overexpression of the lysosomal-associated membrane protein 2a in cellular systems led to upregulation of chaperone-mediated autophagy, decreased alpha-synuclein turnover, and selective protection against adenoviral-mediated wild-type alpha-synuclein neurotoxicity. Protection was observed even when the steady-state levels of alpha-synuclein were unchanged, suggesting that it occurred through the attenuation of alpha-synuclein-mediated dysfunction of chaperone-mediated autophagy. Overexpression of the lysosomal receptor through the nigral injection of recombinant adeno-associated virus vectors effectively ameliorated alpha-synuclein-induced dopaminergic neurodegeneration by increasing the survival of neurons located in the substantia nigra as well as the axon terminals located in the striatum, which was associated with a reduction in total alpha-synuclein levels and related aberrant species. We conclude that induction of chaperone-mediated autophagy may provide a novel therapeutic strategy in Parkinson's disease and related synucleinopathies through two different mechanisms: amelioration of dysfunction of chaperone-mediated autophagy and lowering of alpha-synuclein levels.
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| 3. |
- Xilouri, Maria, et al.
(författare)
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Selective neuroprotective effects of the S18Y polymorphic variant of UCH-L1 in the dopaminergic system
- 2012
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 21:4, s. 874-889
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Tidskriftsartikel (refereegranskat)abstract
- Genetic studies have implicated the neuronal ubiquitin C-terminal hydrolase (UCH) protein UCH-L1 in Parkinson's disease (PD) pathogenesis. Moreover, the function of UCH-L1 may be lost in the brains of PD and Alzheimer's disease patients. We have previously reported that the UCH-L1 polymorphic variant S18Y, potentially protective against PD in population studies, demonstrates specific antioxidant functions in cell culture. Albeit genetic, biochemical and neuropathological data support an association between UCH-L1, PD, synaptic degeneration and oxidative stress, the relationship between the dopaminergic system and UCH-L1 status remains obscure. In the current study, we have examined the dopaminergic system of mice lacking endogenous UCH-L1 protein (gracile axonal dystrophy mice). Our findings show that the lack of wild-type (WT) UCH-L1 does not influence to any significant degree the dopaminergic system at baseline or following injections of the neurotoxin methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Furthermore, using a novel intrastriatal adenoviral injection protocol, we have found that mouse nigral neurons retrogradely transduced with S18Y UCH-L1, but not the WT protein, are significantly protected against MPTP toxicity. Overall, these data provide evidence for an antioxidant and neuroprotective effect of the S18Y variant of UCH-L1, but not of the WT protein, in the dopaminergic system, and may have implications for the pathogenesis of PD or related neurodegenerative conditions, in which oxidative stress might play a role.
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