Nerve growth factor (NGF) deprivation induces a Bax-dependent, caspase-dependent programmed cell death in sympathetic neurons. We examined whether the release of cytochrome c was accompanied by the loss of mitochondrial membrane potential during sympathetic neuronal death. NGF- deprived, caspase inhibitor-treated mouse sympathetic neurons maintained mitochondrial membrane potential for 25-30 h ...

17beta-Estradiol (E(2)) reduces oxidative stress-induced depolarization of mitochondrial membrane potential (MMP) in cultured human lens epithelial cells (HLE-B3). The mechanism by which the nongenomic effects of E(2) contributed to the protection against mitochondrial membrane depolarization was investigated. Mitochondrial membrane integrity is regulated by phosphorylation of BAD, and it is kn...

Adenine nucleotide translocase 2 (ANT2) transports glycolytic ATP across the inner mitochondrial membrane. Patients with ANT2 deletion were recently reported. We aimed at characterizing mitochondrial functions in ANT2-defective fibroblasts. In spite of ANT2 expression in fibroblasts, we observed no difference between ANT2-defective and control fibroblasts for mitochondrial respiration, respirat...

Yme1p, an ATP-dependent protease localized in the mitochondrial inner membrane, is required for the growth of yeast lacking an intact mitochondrial genome. Specific dominant mutations in the genes encoding the alpha- and gamma-subunits of the mitochondrial F(1)F(0)-ATPase suppress the slow-growth phenotype of yeast that simultaneously lack Yme1p and mitochondrial DNA. F(1)F(0)-ATPase activity i...

A BODIPY-based dye, OBEP, has been developed to act as a mitochondrial fluorescence probe. This dye is of high stability, low toxicity and insensitive in a pH range as wide as pH 2-10. Its uptake into mitochondria is independent of mitochondrial membrane potential in living cells. OBEP can label swollen mitochondria resulting from different degrees of cell damage in light and resist fading even...

Bax, a member of the Bcl-2 family, translocates to mitochondria during apoptosis, where it forms oligomers which are thought to release apoptogenic factors such as cytochrome c. Using anoikis as a model system, we have examined spatial and temporal changes in Bax distribution. Bax translocates to mitochondria within 15 min of detaching cells from extracellular matrix, but mitochondrial permeabi...

By using a potential-dependent J-aggregate-forming delocalized lipophilic cation, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine++ + iodide (JC-1), we find that membrane potentials across mitochondria in a living cell can be heterogeneous. Remarkably, even within a long contiguous mitochondrion, regional heterogeneity in membrane potentials appears to be possible.

The subcellular localization of Bax plays a crucial role during apoptosis. In response to apoptotic stimuli, Bax translocates from the cytoplasm to the mitochondria, where it promotes the release of cytochrome c to the cytoplasm. In cells infected with HSV-1, apoptosis is triggered or blocked by diverse mechanisms. In this study, we demonstrate how HSV-1 ICP27 induces apoptosis and modulates mi...

MLN64 is a late endosomal cholesterol-binding membrane protein that has been implicated in cholesterol transport from endosomal membranes to the plasma membrane and/or mitochondria, in toxin-induced resistance, and in mitochondrial dysfunction. Down-regulation of MLN64 in Niemann-Pick C1 deficient cells decreased mitochondrial cholesterol content, suggesting that MLN64 functions independently o...

It is known that hypoxic preconditioning (HP, a brief period of sublethal hypoxia) provides neuroprotection against subsequent severe anoxia, but the mechanisms of this increased tolerance have not been fully elucidated. A hypoxic preconditioning model was established by exposing a 4-day hippocampal culture to 1% O(2) for 20 min/day for 8 days. The preconditioning significantly decreased the nu...