Publications by authors named "Giuseppe Paradies"

In eukaryotic cells, mitochondria are involved in a large array of metabolic and bioenergetic processes that are vital for cell survival. Phospholipids are the main building blocks of mitochondrial membranes. Cardiolipin (CL) is a unique phospholipid which is localized and synthesized in the inner mitochondrial membrane (IMM).

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Mitochondrial dysfunction plays a central role in myocardial ischemia-reperfusion (I/R) injury. Increased reactive oxygen species production, impaired electron transport chain activity, aberrant mitochondrial dynamics, Ca overload, and opening of the mitochondrial permeability transition pore have been proposed as major contributory factors to mitochondrial dysfunction during myocardial I/R injury. Cardiolipin (CL), a mitochondria-specific phospholipid, plays a pivotal role in multiple mitochondrial bioenergetic processes, including respiration and energy conversion, in mitochondrial morphology and dynamics as well as in several steps of the apoptotic process.

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Aging is a biological process characterized by progressive decline in physiological functions, increased oxidative stress, reduced capacity to respond to stresses, and increased risk of contracting age-associated disorders. Mitochondria are referred to as the powerhouse of the cell through their role in the oxidative phosphorylation to generate ATP. These organelles contribute to the aging process, mainly through impairment of electron transport chain activity, opening of the mitochondrial permeability transition pore and increased oxidative stress.

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Mitochondria are the powerhouse of the eukaryotic cell through their use of oxidative phosphorylation to generate ATP. Mitochondrial dysfunction is considered an important contributing factor in a variety of physiopathological situations such as aging, heart ischemia/reperfusion injury, diabetes and several neurodegenerative and cardiovascular diseases, as well as in cell death. Increased formation of reactive oxygen species, altered respiratory chain complexes activity and opening of the mitochondrial permeability transition pore have been suggested as possible factors responsible for impaired mitochondrial function.

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Nonalcoholic fatty liver disease (NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors.

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Cardiolipin is a unique phospholipid which is almost exclusively located in the inner mitochondrial membrane where it is biosynthesized. Considerable progress has recently been made in understanding the role of cardiolipin in mitochondrial function and bioenergetics. This phospholipid is associated with membranes designed to generate an electrochemical gradient that is used to produce ATP, such as bacterial plasma membranes and inner mitochondrial membrane.

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Cardiolipin (CL) is a unique phospholipid that is almost exclusively localized at the level of the inner mitochondrial membrane (IMM), where it is biosynthesized. This phospholipid is associated with membranes which are designed to generate an electrochemical gradient that is used to produce ATP. Such membranes include the bacterial plasma membrane and IMM.

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Reactive oxygen species (ROS) are considered a key factor in mitochondrial dysfunction associated with brain aging process. Mitochondrial respiration is an important source of ROS and hence a potential contributor to brain functional changes with aging. In this study, we examined the effect of aging on cytochrome c oxidase activity and other bioenergetic processes such as oxygen consumption, membrane potential and ROS production in rat brain mitochondria.

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Aging is a biological process associated with impairment of mitochondrial bioenergetic function, increased oxidative stress, attenuated ability to respond to stresses and increased risk in contracting age-associated diseases. When mitochondria are subjected to oxidative stress, accompanied by calcium overload and ATP depletion, they undergo "a permeability transition", characterized by sudden induced change of the inner mitochondrial membrane permeability for water as well as for low-molecular weight solutes (≤1.5kDa), resulting in membrane depolarization and uncoupling of oxidative phosphorylation.

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Aging is a biological process characterized by impairment of cellular bioenergetic function, increased oxidative stress, attenuated ability to respond to stresses, increased risk of contracting age-associated disorders that affects many tissues, with a more marked effect on brain and heart function. Oxidative stress is widely thought to underpin many aging processes. The mitochondrion is considered the most important cellular organelle to contribute to the aging process, mainly through respiratory chain dysfunction and formation of reactive oxygen species, leading to damage to mitochondrial proteins, lipids and mitochondrial DNA.

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Melatonin is a natural occurring compound with well-known antioxidant properties. Melatonin is ubiquitously distributed and because of its small size and amphiphilic nature, it is able to reach easily all cellular and subcellular compartments. The highest intracellular melatonin concentrations are found in mitochondria, raising the possibility of functional significance for this targeting with involvement in situ in mitochondrial activities.

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Dietary choline deprivation (CD) is associated with behavioral changes, but mechanisms underlying these detrimental effects are not well characterized. For instance, no literature data are available concerning the CD effects on brain mitochondrial function related to impairment in cognition. Therefore, we investigated brain mitochondrial function and redox status in male Wistar rats fed a CD diet for 28 d.

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Aging is associated with a decline of cardiac function. The mitochondrial permeability transition (MPT) may be a factor in cardiac dysfunction associated with aging. We investigated the effect of aging and long-term treatment with melatonin (approximately 10 mg/kg b.

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Aging is a natural, complex, and multifactorial biological process associated with impairment of bioenergetic function, increased oxidative stress, attenuated ability to respond to stresses, and increased risk of contracting age-associated diseases. Oxidative stress is widely thought to underpin many aging processes. The mitochondrion, the powerhouse of the cell, is considered the most important cellular organelle to contribute to the aging process, mainly through respiratory chain dysfunction and formation of reactive oxygen species, leading to damage to mitochondrial proteins, lipids, and mitochondrial DNA.

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Melatonin, a well-known antioxidant, has been shown to protect against ischemia-reperfusion myocardial damage. Mitochondrial permeability transition pore (MPTP) opening is an important event in cardiomyocyte cell death occurring during ischemia-reperfusion and therefore a possible target for cardioprotection. In the present study, we tested the hypothesis that melatonin could protect heart against ischemia-reperfusion injury by inhibiting MPTP opening.

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Cardiolipin oxidation is emerging as an important factor in mitochondrial dysfunction as well as in the initial phase of the apoptotic process. We have previously shown that exogenously added peroxidized cardiolipin sensitizes mitochondria to Ca(2+)-induced mitochondrial permeability transition (MPT) pore opening and promotes the release of cytochrome c. In this work, the effects of intramitochondrial cardiolipin peroxidation on Ca(2+)-induced MPT and on the cytochrome c release from mitochondria were studied.

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Cardiolipin is a unique phospholipid which is almost exclusively located at the level of the inner mitochondrial membrane where it is biosynthesized. This phospholipid is known to be intimately involved in several mitochondrial bioenergetic processes. In addition, cardiolipin also has active roles in several of the mitochondrial-dependent steps of apoptosis and in mitochondrial membrane dynamics.

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Reactive oxygen species (ROS) are considered a key factor in the heart aging process. Mitochondrial respiration is an important site of ROS generation and a potential contributor to heart functional changes with aging. We have examined the effects of aging on various parameters related to mitochondrial bioenergetics in rat heart, such as complex I activity, oxygen consumption, membrane potential, ROS production, and cardiolipin content and oxidation.

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Reactive oxygen species (ROS) are considered a key factor in brain aging process. Complex I of the mitochondrial respiration chain is an important site of ROS production and hence a potential contributor to brain functional changes with aging. Appropriate antioxidant strategies could be particularly useful to limit this ROS production and associated mitochondrial dysfunction.

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The effect of peroxidized cardiolipin on the mitochondrial pore transition (MPT) induction and cytochrome c release in rat heart mitochondria was studied. Treatment of mitochondria with cardiolipin hydroperoxide (CLOOH) promoted matrix swelling and release of cytochrome c. Both these processes were inhibited by cyclosporine A and bongkrekic acid, indicating that peroxidized cardiolipin behaves as an inducer of MPT.

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Mitochondrial dysfunction and oxidative stress play a central role in the pathophysiology of nonalcoholic fatty liver disease (NAFLD). This study aimed to elucidate the mechanism(s) responsible for mitochondrial dysfunction in nonalcoholic fatty liver. Fatty liver was induced in rats with a choline-deficient (CD) diet for 30 days.

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Cardiolipin peroxidation plays a critical role in mitochondrial cytochrome c release and subsequent apoptotic process. Mitochondrial pore transition (MPT) is considered as an important step in this process. In this work, the effect of peroxidized cardiolipin on MPT induction and cytochrome c release in rat heart mitochondria was investigated.

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Release of cytochrome c from mitochondria is considered a critical, early event in the induction of an apoptosis cascade that ultimately leads to programmed cell death. Mitochondrial Ca(2+) loading is a trigger for the release of cytochrome c, although the molecular mechanism underlying this effect is not fully clarified. This study tested the hypothesis that distinct Ca(2+) thresholds may induce cytochrome c release from rat liver mitochondria by membrane permeability transition (MPT)-dependent and independent mechanisms.

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Several lines of evidence indicate that mitochondria-mediated reactive oxygen species (ROS) generation is a major source of oxidative stress in the cell. Release of cytochrome c from mitochondria is a central event in apoptosis induction and appears to be mediated by ROS. Dissociation of cytochrome c from the IMM, where it is bound to cardiolipin, represents a necessary first step for cytochrome c release.

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Reactive oxygen species (ROS) are considered an important factor in ischemia/reperfusion injury to cardiac myocytes. Mitochondrial respiration is an important source of ROS production and hence a potential contributor to cardiac reperfusion injury. In this study, we have examined the effect of ischemia and ischemia followed by reperfusion of rat hearts on various parameters related to mitochondrial function, such as complex I activity, oxygen consumption, ROS production, and cardiolipin content.

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