Inside-out submitochondrial particles affect the mitochondrial permeability transition pore opening under conditions of mitochondrial dysfunction.

The inside-out submitochondrial particles (IO-SMPs) showed a strong protective effect against mitochondrial permeability transition pore (mPTP) opening in mitochondria isolated from swine hearts 3 h after explantation. The latter condition was used to emulate situation of mitochondrial damage. We identified that the protective effect of IO-SMPs cannot be attributed to a functional modulation of the enzymatic complexes involved in mPTP formation.

Mitochondrial bioenergetic dysfunction linked to myxomatous mitral valve degeneration explored by PBMCs metabolism analysis.

Impaired mitochondria cause an impressive decrease in ATP production becoming a common condition of cardiovascular diseases. Myxomatous mitral valve disease (MMVD) is characterized by mitochondrial dysfunction. By a non-invasive procedure of metabolism analysis on peripheral blood mononuclear cells, we exploit ex-vivo studies that directly constitute a translational approach to evaluate the cell bioenergetics.

Selenite ameliorates the ATP hydrolysis of mitochondrial FF-ATPase by changing the redox state of thiol groups and impairs the ADP phosphorylation.

Selenite as an inorganic form of selenium can affect the redox state of mitochondria by modifying the thiol groups of cysteines. The FF-ATPase has been identified as a mitochondrial target of this compound. Indeed, the bifunctional mechanism of ATP turnover of FF-ATPase was differently modified by selenite.

Two separate pathways underlie NADH and succinate oxidation in swine heart mitochondria: Kinetic evidence on the mobile electron carriers.

We have investigated NADH and succinate aerobic oxidation in frozen and thawed swine heart mitochondria. Simultaneous oxidation of NADH and succinate showed complete additivity under a variety of experimental conditions, suggesting that the electron fluxes originating from NADH and succinate are completely independent and do not mix at the level of the so-called mobile diffusible components. We ascribe the results to mixing of the fluxes at the level of cytochrome c in bovine mitochondria: the Complex IV flux control coefficient in NADH oxidation was high in swine mitochondria but very low in bovine mitochondria, suggesting a stronger interaction of cytochrome c with the supercomplex in the former.

Iron Bioaccessibility and Speciation in Microalgae Used as a Dog Nutrition Supplement.

, , , and are species of interest for commercial purposes due to their valuable nutritional profile. The aim of this study was to investigate the iron content in these four microalgae, with emphasis on their iron bioaccessibility assessed using an in vitro digestion system to simulate the process which takes place in the stomach and small intestine of dogs, followed by iron quantification using atomic absorption spectrometry. Furthermore, the extraction of soluble proteins was carried out and size exclusion chromatography was applied to investigate iron speciation.

Supplementation of and Extracts during the Early Laying Phase: Effects on Serum and Albumen Proteins, Trace Elements, and Yolk Cholesterol.

Extracts from () and () are used as supplements in poultry feed. The aims of this research were to study the possible effects of dietary supplementation with and extracts on serum and albumen proteins, zinc and iron, and yolk cholesterol content in Leghorn hens during the critical phase of the onset of laying. A total of 120 pullets, 17 weeks of age, were assigned to two groups (control (C) and treated (T), n = 60 each).

The inhibition of gadolinium ion (Gd) on the mitochondrial FF-ATPase is linked to the modulation of the mitochondrial permeability transition pore.

The mitochondrial permeability transition pore (PTP), which drives regulated cell death when Ca concentration suddenly increases in mitochondria, was related to changes in the Ca-activated FF-ATPase. The effects of the gadolinium cation (Gd), widely used for diagnosis and therapy, and reported as PTP blocker, were evaluated on the FF-ATPase activated by Mg or Ca and on the PTP. Gd more effectively inhibits the Ca-activated FF-ATPase than the Mg-activated FF-ATPase by a mixed-type inhibition on the former and by uncompetitive mechanism on the latter.

Sulfide affects the mitochondrial respiration, the Ca-activated FF-ATPase activity and the permeability transition pore but does not change the Mg-activated FF-ATPase activity in swine heart mitochondria.

In mammalian cells enzymatic and non-enzymatic pathways produce HS, a gaseous transmitter which recently emerged as promising therapeutic agent and modulator of mitochondrial bioenergetics. To explore this topic, the HS donor NaHS, at micromolar concentrations, was tested on swine heart mitochondria. NaHS did not affect the FF-ATPase activated by the natural cofactor Mg, but, when Mg was replaced by Ca, a slight 15% enzyme inhibition at 100 µM NaHS was shown.

Mitochondrial FF-ATPase and permeability transition pore response to sulfide in the midgut gland of Mytilus galloprovincialis.

The molecular mechanisms which rule the formation and opening of the mitochondrial permeability transition pore (mPTP), the lethal mechanism which permeabilizes mitochondria to water and solutes and drives the cell to death, are still unclear and particularly little investigated in invertebrates. Since Ca increase in mitochondria is accompanied by mPTP opening and the participation of the mitochondrial FF-ATPase in the mPTP is increasingly sustained, the substitution of the natural cofactor Mg by Ca in the FF-ATPase activation has been involved in the mPTP mechanism. In mussel midgut gland mitochondria the similar kinetic properties of the Mg- or Ca-dependent FF-ATPase activities, namely the same affinity for ATP and bi-site activation kinetics by the ATP substrate, in spite of the higher enzyme activity and coupling efficiency of the Mg-dependent FF-ATPase, suggest that both enzyme activities are involved in the bioenergetic machinery.

Mitochondrial Ca -activated F F -ATPase hydrolyzes ATP and promotes the permeability transition pore.

The properties of the mitochondrial F F -ATPase catalytic site, which can bind Mg , Mn , or Ca and hydrolyze ATP, were explored by inhibition kinetic analyses to cast light on the Ca -activated F F -ATPase connection with the permeability transition pore (PTP) that initiates cascade events leading to cell death. While the natural cofactor Mg activates the F F -ATPase in competition with Mn , Ca is a noncompetitive inhibitor in the presence of Mg . Selective F inhibitors (Is-F ), namely NBD-Cl, piceatannol, resveratrol, and quercetin, exerted different mechanisms (mixed and uncompetitive inhibition) on either Ca - or Mg -activated F F -ATPase, consistent with the conclusion that the catalytic mechanism changes when Mg is replaced by Ca .

Lipid-protein interactions in mitochondrial membranes from bivalve mollusks: molecular strategies in different species.

The mitochondrial FF-ATPase, the key enzyme in cell bioenergetics, apparently works in the same way in mollusks and in mammals. We previously pointed out a raft-like arrangement in mussel gill mitochondrial membranes, which apparently distinguishes bivalve mollusks from mammals. To explore the relationship between the microenvironmental features and the enzyme activity, the physico-chemical features of mitochondrial membranes and the FF-ATPase activity temperature-dependence are here explored in the Manila clam (Ruditapes philippinarum).

Lipid unsaturation per se does not explain the physical state of mitochondrial membranes in Mytilus galloprovincialis.

Through a multiple approach, the present study on the mitochondrial membranes from mussel gills and swine heart combines some biochemical information on fatty acid composition, sterol pattern, and temperature dependence of the F1FO-ATPase activity (EC 3.6.3.

Metal distribution and metallothionein in loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles.

The first aim of our study was to determine the concentrations of selected trace elements (Zn, Cu, Fe, Mn, Cd and Pb) in tissues of green turtles from Tortuguero National Park on the North Caribbean coast of Costa Rica and of loggerheads from the Mediterranean Sea. Zn, Cu, Fe, Mn and Cd were present at detectable concentrations in all samples and showed clear organotropism, whereas Pb was not always over the detection limit and did not show any particular tissue distribution. The two species presented significant differences: Cu and Cd in liver and kidney of Chelonia mydas were significantly higher with respect to the concentrations found in Caretta caretta.