43 Maple syrup urine disease metabolites induce apoptosis in neural cells without cytochrome c release or changes in mitochondrial membrane potential

1998 ◽  
Vol 26 (4) ◽  
pp. S341-S341 ◽  
Author(s):  
Philippe Jouvet ◽  
Pierre Rustin ◽  
Ursula Felderhoff ◽  
Jennifer Pocock ◽  
Umesh Joashi ◽  
...  
2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Toshitaka Yajima ◽  
Stanley Park ◽  
Hanbing Zhou ◽  
Michinari Nakamura ◽  
Mitsuyo Machida ◽  
...  

MAVS is a mitochondrial outer membrane protein that activates innate antiviral signaling by recognizing cytosolic viral RNAs and DNAs. While the discovery of MAVS is the first molecular evidence that links mitochondria to innate immune mechanisms, it is still unclear whether MAVS affects mitochondrial cell death as a member of caspase activation and recruitment domain (CARD)-containing proteins. We found that MAVS interacts with Bax through CARD by Yeast two-hybrid and a series of immunoprecipitation (IP) assay, which led us to hypothesize that MAVS functions not only in the innate antiviral mechanisms but also in the mitochondrial cell death pathway. Methods: 1) We examined molecular interaction between MAVS and Bax under oxidative stress by IP using isolated myocytes with H2O2 stimulation and the heart post ischemia-reperfusion (I/R). 2) We evaluated the effect of MAVS on mitochondrial membrane potential and apoptosis under H2O2 stimulation using isolated myocytes with adenoviral MAVS knockdown. 3) We investigated the impact of MAVS on %myocardial infarction (%MI) post I/R using cardiac-specific MAVS knockout (cKO) and transgenic (cTg) mice which we have originally generated. 4) We examined the effect of MAVS on recombinant Bax (rBax)-mediated cytochrome c release using isolated mitochondria from wild type (WT) and MAVS KO mice. Results: 1) The amount of Bax pulled down with MAVS was significantly increased in isolated myocytes with 0.2 mM H2O2 compared to those without stimulation (mean±SD; 1.808±0.14, n=5, p<0.001) and in the heart post I/R compared to sham (2.2±1.19, n=3, p=0.0081). 2) Myocytes with MAVS knockdown showed clear abnormalities in mitochondrial membrane potential and caspace-3 cleavage with 0.2 mM H2O2 compared to control cardiomyocytes. 3) MAVS cKO had significantly larger %MI than WT (81.9 ± 5.8% vs. 42.6 ± 13.6%, n=8, p=0.0008). In contrast, MAVS cTg had significantly smaller %MI that WT (30.0 ± 4.8% vs. 49.2 ± 4.8%, n=10, p=0.0113). 4) Mitochondria from MAVS KO exhibited cytochrome c release after incubation with 2.5 μ g of rBax while those from WT required 10 μ g of rBax. Conclusion: These results demonstrate that MAVS protects cardiomyocyte under oxidative stress by interfering with Bax-mediated cytochrome c release from mitochondria.


2000 ◽  
Vol 11 (5) ◽  
pp. 1919-1932 ◽  
Author(s):  
Philippe Jouvet ◽  
Pierre Rustin ◽  
Deanna L. Taylor ◽  
Jennifer M. Pocock ◽  
Ursula Felderhoff-Mueser ◽  
...  

Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by a deficiency in branched chain α-keto acid dehydrogenase that can result in neurodegenerative sequelae in human infants. In the present study, increased concentrations of MSUD metabolites, in particular α-keto isocaproic acid, specifically induced apoptosis in glial and neuronal cells in culture. Apoptosis was associated with a reduction in cell respiration but without impairment of respiratory chain function, without early changes in mitochondrial membrane potential and without cytochrome c release into the cytosol. Significantly, α-keto isocaproic acid also triggered neuronal apoptosis in vivo after intracerebral injection into the developing rat brain. These findings suggest that MSUD neurodegeneration may result, at least in part, from an accumulation of branched chain amino acids and their α-keto acid derivatives that trigger apoptosis through a cytochrome c-independent pathway.


2000 ◽  
Vol 150 (1) ◽  
pp. 131-144 ◽  
Author(s):  
Mohanish Deshmukh ◽  
Keisuke Kuida ◽  
Eugene M. Johnson

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 poten-tial for 25–30 h after releasing cytochrome c. NGF- deprived sympathetic neurons became committed to die, as measured by the inability of cells to be rescued by NGF readdition, at the time of cytochrome c release. In the presence of caspase inhibitor, however, this commitment to death was extended beyond the point of cytochrome c release, but only up to the subsequent point of mitochondrial membrane potential loss. Caspase-9 deficiency also arrested NGF-deprived sympathetic neurons after release of cytochrome c, and permitted these neurons to be rescued with NGF readdition. Commitment to death in the NGF-deprived, caspase- 9–deficient sympathetic neurons was also coincident with the loss of mitochondrial membrane potential. Thus, caspase inhibition extended commitment to death in trophic factor–deprived sympathetic neurons and allowed recovery of neurons arrested after the loss of cytochrome c, but not beyond the subsequent loss of mitochondrial membrane potential.


2008 ◽  
Vol 30 (5) ◽  
pp. 435-450
Author(s):  
Wilfried Kugler ◽  
Leo Veenman ◽  
Yulia Shandalov ◽  
Svetlana Leschiner ◽  
Ilana Spanier ◽  
...  

Background: We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway.Methods: With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm.Results: The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inhibited collapse of the mitochondrial membrane potential, cytochrome c release, and caspase-9 and -3 activation caused by ErPC3 treatment.Conclusions: This study shows that PK 11195 and Ro5 4864 inhibit the pro-apoptotic function of ErPC3 by blocking its capacity to cause a collapse of the mitochondrial membrane potential. Thus, the TSPO may serve to open the MPTP in response to anti-cancer drugs such as ErPC3.


Drug Research ◽  
2019 ◽  
Vol 69 (10) ◽  
pp. 523-527
Author(s):  
Fatemeh Samiei ◽  
Hanieh Sajjadi ◽  
Akram Jamshidzadeh ◽  
Enayatollah Seydi ◽  
Jalal Pourahmad

AbstractRivaroxaban as a small molecule is able to directly and reversibly inhibit the factor Xa. This study was designed to figure out the evaluation effect of rivaroxaban on mitochondria obtained from rat kidneys. We isolated mitochondria from rat kidneys using gradient centrifugation. Then, the toxicity parameters including succinate dehydrogenase (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial swelling, mitochondrial membrane potential (MMP) collapse and cytochrome c release were measured in kidneys mitochondria following the exposure to rivaroxaban. The results showed that rivaroxaban (1.4 and 2.8 mM) raised the reactive oxygen species (ROS) generation, swelling in the mitochondria, collapse in the mitochondrial membrane potential (MMP) and cytochrome c release in the mitochondria isolated from kidneys. While, rivaroxaban at a higher concentration of 5.6 mM showed the opposite effect compared to other lower concentrations. The results indicate that rivaroxaban may have antioxidant effects at high concentrations. The results suggest that rivaroxaban (5.6 mM) has protective effects against oxidative stress and mitochondrial toxicity.


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