Olesoxime improves cerebral mitochondrial dysfunction and enhances Aβ levels in preclinical models of Alzheimer's disease.

Background: Approved drugs for Alzheimer's disease (AD) only have a symptomatic effects and do not intervene causally in the course of the disease. Olesoxime (TRO19622) has been tested in AD disease models characterized by improved amyloid precursor protein processing (AβPP) and mitochondrial dysfunction.

Methods: Three months old Thy-1-AβPP (tg) and wild type mice (wt) received TRO19622 (100 mg/kg b.

Mitochondrial Pharmacology of Dimebon (Latrepirdine) Calls for a New Look at its Possible Therapeutic Potential in Alzheimer's Disease.

Dimebon (latrepirdine), an old antihistaminic drug, showed divergent results in two large clinical trials in Alzheimer disease (AD), which according to our review might be related to the specific pharmacological properties of the drug and the different patient populations included in both studies. Out of the many pharmacological effects of Dimebon, improvement of impaired mitochondrial function seeems to be most relevant for the substantial effects on cognition and behaviour reported in one of the studies, as these effects are already present at the low concentrations of dimebon measured in plasma and tissues of patients and experimental animals. Since impaired mitochondrial function seems to be the major driving force for the progression of the clinical symptoms and since most of the clinical benefits of dimebon originate from an effect on the symptomatic deterioration, mitochondrial improvement can also explain the lack of efficacy of this drug in another clinical trial where symptoms of the patiets remained stable for the time of the study.

MH84 improves mitochondrial dysfunction in a mouse model of early Alzheimer's disease.

Background: Current approved drugs for Alzheimer's disease (AD) only attenuate symptoms, but do not cure the disease. The pirinixic acid derivate MH84 has been characterized as a dual gamma-secretase/proliferator activated receptor gamma (PPARγ) modulator in vitro. Pharmacokinetic studies in mice showed that MH84 is bioavailable after oral administration and reaches the brain.

Olesoxime suppresses calpain activation and mutant huntingtin fragmentation in the BACHD rat.

Huntington's disease is a fatal human neurodegenerative disorder caused by a CAG repeat expansion in the HTT gene, which translates into a mutant huntingtin protein. A key event in the molecular pathogenesis of Huntington's disease is the proteolytic cleavage of mutant huntingtin, leading to the accumulation of toxic protein fragments. Mutant huntingtin cleavage has been linked to the overactivation of proteases due to mitochondrial dysfunction and calcium derangements.

Mitochondrial membrane fluidity is consistently increased in different models of Huntington disease: restorative effects of olesoxime.

Huntington disease (HD) is a fatal neurodegenerative disorder caused by a CAG repeat expansion in exon 1 of the huntingtin gene (HTT). One prominent target of the mutant huntingtin protein (mhtt) is the mitochondrion, affecting its morphology, distribution, and function. Thus, mitochondria have been suggested as potential therapeutic targets for the treatment of HD.

Improvement of mitochondrial function and dynamics by the metabolic enhancer piracetam.

The metabolic enhancer piracetam is used in many countries to treat cognitive impairment in aging, brain injuries, as well as dementia such as AD (Alzheimer's disease). As a specific feature of piracetam, beneficial effects are usually associated with mitochondrial dysfunction. In previous studies we were able to show that piracetam enhanced ATP production, mitochondrial membrane potential as well as neurite outgrowth in cell and animal models for aging and AD.

Rice bran extract protects from mitochondrial dysfunction in guinea pig brains.

Mitochondrial dysfunction plays a major role in the development of age-related neurodegenerative diseases and recent evidence suggests that food ingredients can improve mitochondrial function. In the current study we investigated the effects of feeding a stabilized rice bran extract (RBE) on mitochondrial function in the brain of guinea pigs. Key components of the rice bran are oryzanols, tocopherols and tocotrienols, which are supposed to have beneficial effects on mitochondrial function.

Mitochondria: mitochondrial membranes in brain ageing and neurodegeneration.

Mitochondria are membrane bound organelles that provide cellular energy in form of ATP. In addition to ATP synthesis mitochondria are key regulators of calcium homeostasis, free radical production, steroid synthesis and apoptosis, each of these factors could also be associated with essential mechanisms involved in neurodegenerative diseases. Recent studies revealed that changes in mitochondria membrane fluidity might have a direct impact on membrane-based processes such as fission-associated morphogenic changes, opening of the mitochondrial permeability transition pore or oxidative phosphorylation at the complexes of the electron transport chain.

Mitochondrial dysfunction--a pharmacological target in Alzheimer's disease.

Increasing evidences suggest that mitochondrial dysfunction plays an important role in the pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD). Alterations of mitochondrial efficiency and function are mainly related to alterations in mitochondrial content, amount of respiratory enzymes, or changes in enzyme activities leading to oxidative stress, mitochondrial permeability transition pore opening, and enhanced apoptosis. More recently, structural changes of the network are related to bioenergetic function, and its consequences are a matter of intensive research.

Dimebon ameliorates amyloid-β induced impairments of mitochondrial form and function.

Due to their role in producing energy, as major sources of free radicals, and as critical regulators of apoptosis, mitochondria play a dominant role in the central nervous system (CNS). Mitochondrial dysfunction represents one major pathomechanism of Alzheimer's disease (AD), including impaired function of mitochondrial respiratory chain complexes and deficits of mitochondrial dynamics, such as impaired balance between fission and fusion mechanisms and reduced mitochondrial trafficking. Major consequences are enhanced depletion of mitochondria in axons and dendrites, synaptic dysfunction, and finally neuronal loss.

Mitochondrion-derived reactive oxygen species lead to enhanced amyloid beta formation.

Aims: Intracellular amyloid beta (Aβ) oligomers and extracellular Aβ plaques are key players in the progression of sporadic Alzheimer's disease (AD). Still, the molecular signals triggering Aβ production are largely unclear. We asked whether mitochondrion-derived reactive oxygen species (ROS) are sufficient to increase Aβ generation and thereby initiate a vicious cycle further impairing mitochondrial function.