Evaluation of Mitochondrial Oxidative Stress in the Brain of a Transgenic Mouse Model of Alzheimer’s Disease by in vitro Electron Paramagnetic Resonance Spectroscopy

2019 ◽  
Vol 67 (3) ◽  
pp. 1079-1087 ◽  
Author(s):  
Tatsuo Manabe ◽  
Akihiro Matsumura ◽  
Kazuki Yokokawa ◽  
Taro Saito ◽  
Mai Fujikura ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Transgenic Mouse Model ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Mitochondrial Oxidative Stress ◽  
Model Of Alzheimer’S Disease ◽  
Electron Paramagnetic ◽  
The Brain

scholarly journals Dynamics of estrogen-induced oxidative stress.

2007 ◽  
Vol 54 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Jarek Kobiela ◽  
Tomasz Stefaniak ◽  
Jacek Krajewski ◽  
Beata Kalinska-Blach ◽  
Dorota Zurawa-Janicka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Rodent Model ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Biochemical Assays ◽  
Target Organs ◽  
Dna Modifications ◽  
Initial Implantation ◽  
Electron Paramagnetic

The objective of this study was to assess the dynamics of oxidative damage to cellular macromolecules such as proteins, lipids and DNA under conditions of oxidative stress triggering early stages of estrogen-dependent carcinogenesis. A rodent model of carcinogenesis was used. Syrian hamsters were sacrificed after 1, 3, 5 h and one month from the initial implantation of estradiol. Matching control groups were used. Kidneys as target organs for estradiol-mediated oxidative stress were excised and homogenized for biochemical assays. Subcellular fractions were isolated. Carbonyl groups (as a marker of protein oxidation) and lipid hydroxyperoxides were assessed. DNA was isolated and 8-oxodGuo was assessed. Electron paramagnetic resonance spectroscopy was used to confirm the results for lipid peroxidation. Exposition to estradiol in the rodent model leads to damage of macromolecules of the cell, including proteins and DNA, but not lipids. Proteins appear to be the primary target of the damage but are closely followed by DNA. It has previously been speculated that protein peroxides can increase DNA modifications. This time sequence was observed in our study. Nevertheless, the direct relation between protein and DNA damage still remains unsolved.

scholarly journals Besifloxacin liposomes with positively charged additives for an improved topical ocular delivery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Giselly Almeida dos Santos ◽  
Ricardo Ferreira-Nunes ◽  
Luciana Facco Dalmolin ◽  
Ana Carolina dos Santos Ré ◽  
Jorge Luiz Vieira Anjos ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Defense Mechanisms ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Drug Penetration ◽  
Current Application ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
Positively Charged

Abstract Topical ophthalmic antibiotics show low efficacy due to the well-known physiological defense mechanisms of the eye, which prevents the penetration of exogenous substances. Here, we aimed to incorporate besifloxacin into liposomes containing amines as positively charged additives and to evaluate the influence of this charge on drug delivery in two situations: (i) iontophoretic and (ii) passive treatments. Hypothesis are (i) charge might enhance the electromigration component upon current application improving penetration efficiency for a burst drug delivery, and (ii) positive charge might prolong formulation residence time, hence drug penetration. Liposomes elaborated with phosphatidylcholine (LP PC) or phosphatidylcholine and spermine (LP PC: SPM) were stable under storage at 6 ºC for 30 days, showed mucoadhesive characteristics, and were non-irritant, according to HET-CAM tests. Electron paramagnetic resonance spectroscopy measurements showed that neither the drug nor spermine incorporations produced evident alterations in the fluidity of the liposome's membranes, which retained their structural stability even under iontophoretic conditions. Mean diameter and zeta potential were 177.2 ± 2.7 nm and − 5.7 ± 0.3 mV, respectively, for LP PC; and 175.4 ± 1.9 nm and + 19.5 ± 1.0 mV, respectively, for LP PC:SPM. The minimal inhibitory concentration (MIC) and the minimal bactericide concentration (MBC) of the liposomes for P. aeruginosa showed values lower than the commercial formulation (Besivance). Nevertheless, both formulations presented a similar increase in permeability upon the electric current application. Hence, liposome charge incorporation did not prove to be additionally advantageous for iontophoretic therapy. Passive drug penetration was evaluated through a novel in vitro ocular model that simulates the lacrimal flow and challenges the formulation resistance in the passive delivery situation. As expected, LP PC: SPM showed higher permeation than the control (Besivance). In conclusion, besifloxacin incorporation into positively charged liposomes improved passive topical delivery and can be a good strategy to improve topical ophthalmic treatments.

scholarly journals The structure and reactivity of the HoxEFU complex from the cyanobacterium Synechocystis sp. PCC 6803

2020 ◽  
Vol 295 (28) ◽  
pp. 9445-9454
Author(s):  
Jacob H. Artz ◽  
Monika Tokmina-Lukaszewska ◽  
David W. Mulder ◽  
Carolyn E. Lubner ◽  
Kirstin Gutekunst ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Electron Flow ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Cellular Components ◽  
Electron Carriers ◽  
Electron Paramagnetic ◽  
Photosynthetic Electron Transfer

Cyanobacterial Hox is a [NiFe] hydrogenase that consists of the hydrogen (H2)-activating subunits HoxYH, which form a complex with the HoxEFU assembly to mediate reactions with soluble electron carriers like NAD(P)H and ferredoxin (Fdx), thereby coupling photosynthetic electron transfer to energy-transforming catalytic reactions. Researchers studying the HoxEFUYH complex have observed that HoxEFU can be isolated independently of HoxYH, leading to the hypothesis that HoxEFU is a distinct functional subcomplex rather than an artifact of Hox complex isolation. Moreover, outstanding questions about the reactivity of Hox with natural substrates and the site(s) of substrate interactions and coupling of H2, NAD(P)H, and Fdx remain to be resolved. To address these questions, here we analyzed recombinantly produced HoxEFU by electron paramagnetic resonance spectroscopy and kinetic assays with natural substrates. The purified HoxEFU subcomplex catalyzed electron transfer reactions among NAD(P)H, flavodoxin, and several ferredoxins, thus functioning in vitro as a shuttle among different cyanobacterial pools of reducing equivalents. Both Fdx1-dependent reductions of NAD+ and NADP+ were cooperative. HoxEFU also catalyzed the flavodoxin-dependent reduction of NAD(P)+, Fdx2-dependent oxidation of NADH and Fdx4- and Fdx11-dependent reduction of NAD+. MS-based mapping identified an Fdx1-binding site at the junction of HoxE and HoxF, adjacent to iron-sulfur (FeS) clusters in both subunits. Overall, the reactivity of HoxEFU observed here suggests that it functions in managing peripheral electron flow from photosynthetic electron transfer, findings that reveal detailed insights into how ubiquitous cellular components may be used to allocate energy flow into specific bioenergetic products.

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