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.

A comparative study of bioenergetic metabolism on mammary epithelial cells from humans and Göttingen Minipigs.

Mammary epithelial cells (MECs) of humans (h) and Göttingen Minipigs (mp) were analyzed to compare their ability to perform ATP production by oxidative phosphorylation and glycolysis. The ATP production under basal and stressor situations highlights the same metabolic potential of both primary cell lines. However, quantitively the ATP production rate of hMECs was higher than mpMECs.

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.

Isolation and characterization of mammary epithelial cells derived from Göttingen Minipigs: A comparative study versus hybrid pig cells from the IMI-ConcePTION Project.

The value of pig as "large animal model" is a well-known tool for translational medicine, but it can also be beneficial in studying animal health in a one-health vision. The ConcePTION Project aims to provide new information about the risks associated with medication use during breastfeeding, as this information is not available for most commonly used drugs. In the IMI-Conception context, Göttingen Minipigs have been preferred to hybrid pigs for their genetic stability and microbiological control.

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.

Cell bioenergetics and ATP production of boar spermatozoa.

Cellular metabolism is an important feature of spermatozoa that deserves more insights to be fully understood, in particular in porcine semen physiology. The present study aims to characterize the balance between glycolytic and oxidative metabolism in boar sperm cells. Agilent Seahorse technology was used to assess both oxygen consumption rate (OCR), as an oxidative metabolism index, and extracellular acidification rate (ECAR), as a glycolytic index.

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.

Novel Regioselective Synthesis of 1,3,4,5-Tetrasubstituted Pyrazoles and Biochemical Valuation on FF-ATPase and Mitochondrial Permeability Transition Pore Formation.

An efficient, eco-compatible, and very cheap method for the construction of fully substituted pyrazoles (Pzs) via eliminative nitrilimine-alkene 1,3-dipolar cycloaddition (ENAC) reaction was developed in excellent yield and high regioselectivity. Enaminones and nitrilimines generated in situ were selected as dipolarophiles and dipoles, respectively. A deep screening of the employed base, solvent, and temperature was carried out to optimize reaction conditions.

1,5-disubstituted-1,2,3-triazoles counteract mitochondrial dysfunction acting on FF-ATPase in models of cardiovascular diseases.

The compromised viability and function of cardiovascular cells are rescued by small molecules of triazole derivatives (Tzs), identified as 3a and 3b, by preventing mitochondrial dysfunction. The oxidative phosphorylation improves the respiratory control rate in the presence of Tzs independently of the substrates that energize the mitochondria. The FF-ATPase, the main candidate in mitochondrial permeability transition pore (mPTP) formation, is the biological target of Tzs and hydrophilic F domain of the enzyme is depicted as the binding region of Tzs.

The Impairment of Cell Metabolism by Cardiovascular Toxicity of Doxorubicin Is Reversed by Bergamot Polyphenolic Fraction Treatment in Endothelial Cells.

The beneficial effects of bergamot polyphenolic fraction (BPF) on the mitochondrial bioenergetics of porcine aortic endothelial cells (pAECs) were verified under the cardiotoxic action of doxorubicin (DOX). The cell viability of pAECs treated for 24 h with different concentrations of DOX was reduced by 50%, but the negative effect of DOX was reversed in the presence of increasing doses of BPF (100 µg/mL and 200 µg/mL BPF). An analysis of the protective effect of BPF on the toxic action of DOX was also carried out on cell respiration.

Cellular Metabolism and Bioenergetic Function in Human Fibroblasts and Preadipocytes of Type 2 Familial Partial Lipodystrophy.

LMNA mutation is associated with type-2 familial partial lipodystrophy (). The disease causes a disorder characterized by anomalous accumulation of body fat in humans. The dysfunction at the molecular level is triggered by a lamin A/C mutation, impairing the cell metabolism.

The Evaluation of the Effects of Dietary Vitamin E or Selenium on Lipid Oxidation in Rabbit Hamburgers: Comparing TBARS and Hexanal SPME-GC Analyses.

The effects and specificity of dietary supplementation of EconomasE (EcoE), mainly consisting of organic selenium (0.15 or 0.30 mg/kg feed; Se) or of vitamin E (100 or 200 mg/kg feed; VE), on lipid oxidation were evaluated in rabbit hamburgers during refrigerated storage.

Mitochondria Bioenergetic Functions and Cell Metabolism Are Modulated by the Bergamot Polyphenolic Fraction.

The bergamot polyphenolic fraction (BPF) was evaluated in the FF-ATPase activity of swine heart mitochondria. In the presence of a concentration higher than 50 µg/mL BPF, the ATPase activity of FF-ATPase, dependent on the natural cofactor Mg, increased by 15%, whereas the enzyme activity in the presence of Ca was inhibited by 10%. By considering this opposite BPF effect, the FF-ATPase activity involved in providing ATP synthesis in oxidative phosphorylation and triggering mitochondrial permeability transition pore (mPTP) formation has been evaluated.

The mitochondrial FF-ATPase exploits the dithiol redox state to modulate the permeability transition pore.

The dithiol reagents phenylarsine oxide (PAO) and dibromobimane (DBrB) have opposite effects on the FF-ATPase activity. PAO 20% increases ATP hydrolysis at 50 μM when the enzyme activity is activated by the natural cofactor Mg and at 150 μM when it is activated by Ca. The PAO-driven FF-ATPase activation is reverted to the basal activity by 50 μM dithiothreitol (DTE).

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.

Vitamin K Vitamers Differently Affect Energy Metabolism in IPEC-J2 Cells.

The fat-soluble vitamin K (VK) has long been known as a requirement for blood coagulation, but like other vitamins, has been recently recognized to play further physiological roles, particularly in cell development and homeostasis. Vertebrates cannot synthesize VK, which is essential, and it can only be obtained from the diet or by the activity of the gut microbiota. The IPEC-J2 cell line, obtained from porcine small intestine, which shows strong similarities to the human one, represents an excellent functional model to study the effect of compounds at the intestinal level.

Molecular and Supramolecular Structure of the Mitochondrial Oxidative Phosphorylation System: Implications for Pathology.

Under aerobic conditions, mitochondrial oxidative phosphorylation (OXPHOS) converts the energy released by nutrient oxidation into ATP, the currency of living organisms. The whole biochemical machinery is hosted by the inner mitochondrial membrane (mtIM) where the protonmotive force built by respiratory complexes, dynamically assembled as super-complexes, allows the FF-ATP synthase to make ATP from ADP + Pi. Recently mitochondria emerged not only as cell powerhouses, but also as signaling hubs by way of reactive oxygen species (ROS) production.

Relationship between serum concentration, functional parameters and cell bioenergetics in IPEC-J2 cell line.

The foetal bovine serum (FBS) concentration could influence functional parameters of IPEC-J2 cells. IPEC-J2 is a non-transformed continuous epithelial cell line that represents an established in vitro model to study porcine gut inflammation and alterations of intestinal integrity. This cell line also represents a good translational model thanks to the high similitudes between pig and human gastrointestinal tract.

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.

1,5-Disubstituted-1,2,3-triazoles as inhibitors of the mitochondrial Ca -activated F F -ATP(hydrol)ase and the permeability transition pore.

The mitochondrial permeability transition pore (mPTP), a high-conductance channel triggered by a sudden Ca concentration increase, is composed of the F F -ATPase. Since mPTP opening leads to mitochondrial dysfunction, which is a feature of many diseases, a great pharmacological challenge is to find mPTP modulators. In our study, the effects of two 1,5-disubstituted 1,2,3-triazole derivatives, five-membered heterocycles with three nitrogen atoms in the ring and capable of forming secondary interactions with proteins, were investigated.

Mitochondrial F-type ATP synthase: multiple enzyme functions revealed by the membrane-embedded F structure.

Of the two main sectors of the F-type ATP synthase, the membrane-intrinsic F domain is the one which, during evolution, has undergone the highest structural variations and changes in subunit composition. The F complexity in mitochondria is apparently related to additional enzyme functions that lack in bacterial and thylakoid complexes. Indeed, the F-type ATP synthase has the main bioenergetic role to synthesize ATP by exploiting the electrochemical gradient built by respiratory complexes.

Phenylglyoxal inhibition of the mitochondrial FF-ATPase activated by Mg or by Ca provides clues on the mitochondrial permeability transition pore.

Phenylglyoxal (PGO), known to cause post-translational modifications of Arg residues, was used to highlight the role of arginine residues of the FF-ATPase, which may be crucial to yield the mitochondrial permeability transition pore (mPTP). In swine heart mitochondria PGO inhibits ATP hydrolysis by the FF-ATPase either sustained by the natural cofactor Mg or by Ca by a similar uncompetitive inhibition mechanism, namely the tertiary complex (ESI) only forms when the ATP substrate is already bound to the enzyme, and with similar strength, as shown by the similar K'i values (0.82 ± 0.

Nicotinamide Nucleotide Transhydrogenase as a Sensor of Mitochondrial Biology.

The enzyme nicotinamide nucleotide transhydrogenase (NNT) transfers hydride from NADH to NADP coupled to H translocation across the inner mitochondrial membrane. In a recent study, Kampjut and Sazanov reveal that the bifunctional NNT mechanism rules the NAD(P)/NAD(P)H interconversion ratio, which in turn regulates antioxidant defense and sirtuin actions.