Presentation on theme: "LAB MEETING 9/13/12 Presented by Lily L. Wong, Ph.D."— Presentation transcript:
LAB MEETING 9/13/12 Presented by Lily L. Wong, Ph.D.
Sakami et al. (2011)Sakami et al. (2011) found that transgenic mice expressing mouse opsin with the P23H mutation developed retinal degeneration similar to the human disease, with outer segment disorganization and progressive functional deficits beginning in the rod photoreceptor system. P23H protein was inadequately glycosylated and degraded. It did not accumulate in the endoplasmic reticulum but disrupted the rod photoreceptor disks and caused perpendicularly oriented elongated discs. Retinal degeneration in adult transgenic mice appeared to be mainly due to necrosis.
We have shown that CeNP administration can slow photoreceptor degeneration in the P23H-1 heterozygous rats-----see poster outside conference room. Qu: What is the cellular mechanism of CeNP in this neuroprotection model? Ho: ….
Isoprostanes are products of free radical-catalyzed peroxidation of arachidonic acid (C20 polyunsaturated fatty acids ) independent of PGHS (Prostaglandin H Synthase). JD Morrow and colleagues published in 1990 that the presence of isoprostanes as Reliable markers for lipid peroxidation for both in vitro and in vivo systems.
Proposed mechanism for the formation of F 2 -isoprostanes
Abstract Oxidation products of lipids, proteins, and DNA in the blood, plasma, and urine of rats were measured as part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative stress. This article is the second report of the nationwide Biomarkers of Oxidative Stress Study using acute CCl4 poisoning as a rodent model for oxidative stress. The time-dependent (2, 7, and 16 h) and dose- dependent (120 and 1200 mg/kg i.p.) effects of CCl4 on concentrations of lipid hydroperoxides, TBARS, malondialdehyde (MDA), isoprostanes, protein carbonyls, methionine sulfoxidation, tyrosine products, 8-hydroxy-2'-deoxyguanosine (8-OHdG), leukocyte DNA-MDA adducts, and DNA-strand breaks were investigated to determine whether the oxidative effects of CCl4 would result in increased generation of these oxidation products. Plasma concentrations of MDA and isoprostanes (both measured by GC-MS) and urinary concentrations of isoprostanes (measured with an immunoassay or LC/MS/MS) were increased in both low-dose and high-dose CCl4-treated rats at more than one time point. The other urinary markers (MDA and 8-OHdG) showed significant elevations with treatment under three of the four conditions tested. It is concluded that measurements of MDA and isoprostanes in plasma and urine as well as 8-OHdG in urine are potential candidates for general biomarkers of oxidative stress. All other products were not changed by CCl4 or showed fewer significant effects. Free Radic Biol Med.Free Radic Biol Med Mar 15;38(6): Biomarkers of oxidative stress study II: are oxidation products of lipids, proteins, and DNA markers of CCl4 poisoning? Kadiiska MBKadiiska MB, Gladen BC, Baird DD, Germolec D, Graham LB, Parker CE, Nyska A, Wachsman JT, Ames BN, Basu S, Brot N, Fitzgerald GA, Floyd RA, George M, Heinecke JW, Hatch GE, Hensley K, Lawson JA, Marnett LJ, Morrow JD, Murray DM, Plastaras J, Roberts LJ 2nd, Rokach J, Shigenaga MK, Sohal RS, Sun J, Tice RR, Van Thiel DH, Wellner D, Walter PB, Tomer KB, Mason RP, Barrett JC.Gladen BCBaird DDGermolec DGraham LBParker CENyska AWachsman JTAmes BNBasu SBrot NFitzgerald GAFloyd RAGeorge MHeinecke JWHatch GEHensley KLawson JAMarnett LJMorrow JDMurray DMPlastaras JRoberts LJ 2ndRokach JShigenaga MKSohal RSSun JTice RRVan Thiel DHWellner DWalter PBTomer KBMason RPBarrett JC Source Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, P.O. Box 12233, MD F0-02, Research Triangle Park, NC 27709, USA.
Isoprostanes are accurate and sensitive markers of oxidative stress Chemically stable end products From specific fatty acids Esterified in membranes---long lasting marker for oxidant injury We use the Cayman isoprostane kit for our experiments: https://www.caymanchem.com/app/template/Product.vm/catalog/ https://www.caymanchem.com/pdfs/ pdf Go to page 4