Effect of cultural conditions on the lipid profile of Thiobacillus ferroxidas

The intensitive investigations on the lipid profile of Thiobacillus ferrooxidans at various culture ages suggest some correlations of the lipid constitutents with the membrane-bound iron oxidation system. Phosphatidic acid, phosphatidyl serine and phosphatidyl ethanolamine were the major polar components; hydrocarbon, triglyceride and diglyceride were the main neutral components. Major fatty acids were C_16:0, C_16:1, C_16:3, C_18:1, C_18:3, C_22:1 while C_20:1, C_20:2, C_12:0, C_14:2, C_18:0, C_18:2, C_20:0, C_22:0 were found in trace amounts which also depended upon the phase of the growth. One lipoamino acid was identified as ornithine lipid in the polar fraction. Each and every component varied to some extent at different growth phasesindicating relationship of these lipids to the iron oxidation system of the strain.     

Wing morph-related physiological differences in adults of temperate population of Pyrrhocoris apterus (L.) (Heteroptera: Pyrrhocoridae)

The reproductive and diapausing adult females of brachypterous morph and macropterous females with reproductive arrest of non-diapause type, originating from the laboratory cultures of Pyrrhocoris apterus, were studied for their feeding and drinking behaviour, digestive enzyme activities, and carbohydrate and lipid contents. The highest feeding and drinking activities were observed in reproductive brachypters, the lowest in macropters. Macropters also differed from brachypters by lower activities of gut lipase, peptidase and protease, lower concentration of haemolymph sugars, and lower weight of fat body, which probably reflects their low feeding activity. The total content of fat body lipids was also lower in macropters (0.6 mg) than in reproductive and diapausing brachypters (4.6 and 7.5 mg, respectively) on day 14. A very high amount of glycogen was found in the fat body of diapausing brachypters, 363 μg on day 14, as opposed to 15 and 80 μg in macropterous and reproductive brachypterous females, respectively. The obtained data indicate that the most important difference between macropterous and brachypterous females with different types of reproductive arrest consists of an enhanced mobilization of lipids for dispersal in macropters and accumulation of energetic reserves for hibernation in brachypters.     

Effects of Ceruloplasmin on Superoxide-Dependent Iron Release from Ferritin and Lipid Peroxidation

Ceruloplasmin (CP) effectively inhibited superoxide and ferritin-dependent peroxidation of phospholipid liposomes, using xanthine oxidase or gamma irradiation of water as sources of superoxide. In addition, CP inhibited superoxide-dependent mobilization of iron from ferritin. suggesting that CP inhibited lipid peroxidation by decreasing the availability of iron from ferritin. CP also exhibited some superoxide scavenging activity as evidenced by its inhibition of superoxide-dependent cytochrome c reduction. However, superoxide scavenging by CP did not quantitatively account for its inhibitory effects on iron release. The effects of CP on iron-catalyzed lipid peroxidation in systems containing exogenously added ferrous iron was also investigated. CP exhibited prooxidant and antioxidant effects; CP stimulated at lower concentrations, reached a maximum. and inhibited at higher concentrations. However. the addition of apoferritin inhibited CP and Fe(II)-catalyzed lipid peroxidation at all concentrations of CP. In addition, CP catalyzed the incorporation of Fe(II) into apoferritin. Collectively these data suggest that CP inhibits superoxide and ferritin-dependent lipid peroxidation via its ability to incorporate reductively-mobilized iron into ferritin.     

l-Malic Acid Fermentation by Mixed Culture of Rhizopus arrhizus and Proteus vulgaris

When Rhizopus arrhizus NRRL 1526 was mix-cultured with Proteus vulgaris AHU 1144, a strain having a high fumarase activity, in a medium containing glucose as a substrate, fumaric acid fermentation was successively converted to l-malic acid fermentation and large amounts of l-malic acid were accumulated as an end product.

As an inoculum of P. vulgaris for this fermentation, cells in the stationary growth phase (48 to 72 hr culture) were much more favorable than those in the exponential growth phase (18 hr culture) and malic acid yields in the former case were as high as about 70 to 75 % based on initial glucose after 3 to 4 days of the mixed culture.     

Intraocular iron injection induces oxidative stress followed by elements of geographic atrophy and sympathetic ophthalmia

Iron has been implicated in the pathogenesis of age‐related retinal diseases, including age‐related macular degeneration (AMD). Previous work showed that intravitreal (IVT) injection of iron induces acute photoreceptor death, lipid peroxidation, and autofluorescence (AF). Herein, we extend this work, finding surprising chronic features of the model: geographic atrophy and sympathetic ophthalmia. We provide new mechanistic insights derived from focal AF in the photoreceptors, quantification of bisretinoids, and localization of carboxyethyl pyrrole, an oxidized adduct of docosahexaenoic acid associated with AMD. In mice given IVT ferric ammonium citrate (FAC), RPE died in patches that slowly expanded at their borders, like human geographic atrophy. There was green AF in the photoreceptor ellipsoid, a mitochondria‐rich region, 4 h after injection, followed later by gold AF in rod outer segments, RPE and subretinal myeloid cells. The green AF signature is consistent with flavin adenine dinucleotide, while measured increases in the bisretinoid all‐trans‐retinal dimer are consistent with the gold AF. FAC induced formation carboxyethyl pyrrole accumulation first in photoreceptors, then in RPE and myeloid cells. Quantitative PCR on neural retina and RPE indicated antioxidant upregulation and inflammation. Unexpectedly, reminiscent of sympathetic ophthalmia, autofluorescent myeloid cells containing abundant iron infiltrated the saline‐injected fellow eyes only if the contralateral eye had received IVT FAC. These findings provide mechanistic insights into the potential toxicity caused by AMD‐associated retinal iron accumulation. The mouse model will be useful for testing antioxidants, iron chelators, ferroptosis inhibitors, anti‐inflammatory medications, and choroidal neovascularization inhibitors.     

Antioxidant and anti‐inflammatory effects of the monocarbonyl curcumin analogs B2BRBC and C66 in monocrotaline‐induced right ventricular hypertrophy

For 22 days after monocrotaline injection two groups of rats received either of the monocarbonyl curcumin analogs (2E,6E)‐2,6‐bis(2‐bromobenzylidene)cycloxehanone (B2BrBC) and (2E,6E)‐2,6‐bis([2‐tri?uoromethyl]benzylidene)cyclohexanone (C66), and their right ventricle parameters were compared to those from the control and the monocrotaline injected animals. B2BrBC and C66 treatments did not prevent the monocrotaline‐induced right ventricular hypertrophy but attenuated the changes in antioxidant enzyme activities and reduced inflammation. The level of thiol‐based nonenzymatic antioxidants did not change in the function of monocrotaline or curcumin analogs treatment. However, due to its stronger antioxidant properties, only B2BrBC treatment was effective in the reduction of monocrotaline‐associated lipid peroxidation. The obtained results suggest that increasing the levels of antioxidant enzymes may not be sufficient to reduce oxidative stress and chronic inflammation optimally and our current study supports the potential of compounds with more than one beneficial biological activity as a promising treatment against the progression of cardiac hypertrophy.     

Mitochondria-targeted penetrating cations as carriers of hydrophobic anions through lipid membranes

High negative electric potential inside mitochondria provides a driving force for mitochondria-targeted delivery of cargo molecules linked to hydrophobic penetrating cations. This principle is utilized in construction of mitochondria-targeted antioxidants (MTA) carrying quinone moieties which produce a number of health benefitting effects by protecting cells and organisms from oxidative stress. Here, a series of penetrating cations including MTA were shown to induce the release of the liposome-entrapped carboxyfluorescein anion (CF), but not of glucose or ATP. The ability to induce the leakage of CF from liposomes strongly depended on the number of carbon atoms in alkyl chain (n) of alkyltriphenylphosphonium and alkylrhodamine derivatives. In particular, the leakage of CF was maximal at n about 10-12 and substantially decreased at n = 16. Organic anions (palmitate, oleate, laurylsulfate) competed with CF for the penetrating cation-induced efflux. The reduced activity of alkylrhodamines with n = 16 or n = 18 as compared to that with n = 12 was ascribed to a lower rate of partitioning of the former into liposomal membranes, because electrical current relaxation studies on planar bilayer lipid membranes showed rather close translocation rate constants for alkylrhodamines with n = 18 and n = 12. Changes in the alkylrhodamine absorption spectra upon anion addition confirmed direct interaction between alkylrhodamines and the anion. Thus, mitochondria-targeted penetrating cations can serve as carriers of hydrophobic anions across bilayer lipid membranes.     

Pacer Is a Mediator of mTORC1 and GSK3-TIP60 Signaling in Regulation of Autophagosome Maturation and Lipid Metabolism

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