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- Agardh, Carl-David, et al.
(författare)
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Expression of antioxidant enzymes in rat retinal ischemia followed by reperfusion.
- 2006
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Ingår i: Metabolism, Clinical and Experimental. - : Elsevier BV. - 1532-8600. ; 55:7, s. 892-898
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the expression and protein levels of antioxidant enzymes in the rat retina exposed to oxidative stress induced by ischemia-reperfusion injury. Retinal ischemia was induced in female Wistar rats by ligation of the optic nerve and vessels behind the left eye bulb, and was followed by reperfusion for 0, 3, 6, or 24 hours. The right eye served as control. RNA and protein were extracted simultaneously from each retina. Expressions of the endogenous antioxidant enzymes glutathione peroxidase (GPx1), catalase (CAT), copper/zinc superoxide dismutase, manganese superoxide dismutase, and the catalytic subunit of glutamylcysteine ligase (GCLc) were analyzed with real-time reverse transcription polymerase chain reaction and related to the endogenous control cyclophilin B. Protein levels were measured with Western blot analysis. During the early phase (0 or 3 hours) of reperfusion, no changes were seen in enzyme expression. After 6 hours, GCLc expression increased by a factor of 1.14 (P =.034), followed by a decline of 0.80 after 24 hours (P =.00004), according to the comparative Ct method. After 24 hours of reperfusion, GPx1 expression increased by a factor of 1.14 (P =.028), and CAT had decreased by 0.82 (P =.022). Expressions of copper/zinc superoxide dismutase and manganese superoxide dismutase showed a tendency toward a decrease by factors of 0.86 (P =.055) and 0.88 (P =.053), respectively, after 24 hours. Protein levels did not differ for any of the antioxidants, regardless of reperfusion time. The slightly increased messenger RNA expression of GPx1 after 24 hours of reperfusion with a concomitant very modest decrease in CAT and GCLc expression and no change in protein levels indicate a very modest, if any, response to oxidative stress generated by ischemia followed by reperfusion in rat retina.
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| 2. |
- Agardh, Elisabet, et al.
(författare)
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Modifying a standard method allows simultaneous extraction of RNA and protein, enabling detection of enzymes in the rat retina with low expressions and protein levels
- 2006
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Ingår i: Metabolism, Clinical and Experimental. - : Elsevier BV. - 1532-8600. ; 55:2, s. 168-174
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to evaluate messenger RNA and protein expression in limited amounts of tissue with low protein content. The Chomczynski method was used for simultaneous extraction of RNA, and protein was modified in the protein isolation step. Template mass and cycling time for the complementary DNA synthesis step of real-time reverse transcription-polymerase chain reaction (RT-PCR) for analysis of catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, the catalytic subunit of glutamylcysteine ligase, glutathione peroxidase 1, and the endogenous control cyclophilin B (CypB) were optimized before PCR. Polymerase chain reaction accuracy and efficacy were demonstrated by calculating the regression (R2) values of the separate amplification curves. Appropriate antibodies, blocking buffers, and running conditions were established for Western blot, and protein detection and multiplex assays with CypB were performed for each target. During the extraction procedure, the protein phase was dissolved in a modified washing buffer containing 0.1% sodium dodecyl sulfate, followed by ultrafiltration. Enzyme expression on real-time RT-PCR was accomplished with high reliability and reproducibility (R2, 0.990-0.999), and all enzymes except for glutathione peroxidase 1 were detectable in individual retinas on Western blot. Western blot multiplexing with CypB was possible for all targets. In conclusion, connecting gene expression directly to protein levels in the individual rat retina was possible by simultaneous extraction of RNA and protein. Real-time RT-PCR and Western blot allowed accurate detection of retinal protein expressions and levels.
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| 3. |
- Gustavsson, Carin, et al.
(författare)
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Inflammatory markers in nondiabetic and diabetic rat retinas exposed to ischemia followed by reperfusion.
- 2008
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Ingår i: Retina. - 0275-004X. ; 28:4, s. 645-652
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:: To examine the retinal inflammatory response to ischemia-reperfusion in nondiabetic and diabetic rats injected with either an omega-3-polyunsaturated fatty acid (docosahexaenoic acid [DHA]) or a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (pravastatin). METHODS:: Diabetes was induced by an intraperitoneal injection of streptozocin, and retinal ischemia was induced by ligation of the optic nerve and vessels, followed by reperfusion for 1 hour or 24 hours. Five minutes before surgery, an intravenous injection of DHA, pravastatin, or vehicle (ethanol) was administered. The mRNA expressions of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, caspase-1, IL-1beta, P-selectin, vascular cellular adhesion molecule (VCAM)-1, and intercellular adhesion molecule (ICAM)-1 were compared between ischemic and nonischemic retinas as well as diabetic and nondiabetic nonischemic retinas. RESULTS:: Ischemia induced increased expressions of TNF-alpha (P
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| 4. |
- Ling, Charlotte, et al.
(författare)
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Genetic and epigenetic factors are associated with expression of respiratory chain component NDUFB6 in human skeletal muscle.
- 2007
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Ingår i: The Journal of clinical investigation. - 0021-9738. ; 117:11, s. 3427-35
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Tidskriftsartikel (refereegranskat)abstract
- Insulin resistance and type 2 diabetes are associated with decreased expression of genes that regulate oxidative phosphorylation in skeletal muscle. To determine whether this defect might be inherited or acquired, we investigated the association of genetic, epigenetic, and nongenetic factors with expression of NDUFB6, a component of the respiratory chain that is decreased in muscle from diabetic patients. Expression of NDUFB6 was influenced by age, with lower gene expression in muscle of elderly subjects. Heritability of NDUFB6 expression in muscle was estimated to be approximately 60% in twins. A polymorphism in the NDUFB6 promoter region that creates a possible DNA methylation site (rs629566, A/G) was associated with a decline in muscle NDUFB6 expression with age. Although young subjects with the rs629566 G/G genotype exhibited higher muscle NDUFB6 expression, this genotype was associated with reduced expression in elderly subjects. This was subsequently explained by the finding of increased DNA methylation in the promoter of elderly, but not young, subjects carrying the rs629566 G/G genotype. Furthermore, the degree of DNA methylation correlated negatively with muscle NDUFB6 expression, which in turn was associated with insulin sensitivity. Our results demonstrate that genetic, epigenetic, and nongenetic factors associate with NDUFB6 expression in human muscle and suggest that genetic and epigenetic factors may interact to increase age-dependent susceptibility to insulin resistance.
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