Neurotoxic Aβ peptides increase oxidative stress in vivo through NMDA-receptor and nitric-oxide-synthase mechanisms, and inhibit complex IV activity and induce a mitochondrial permeability transition in vitro

We have recently shown that deletion of constitutively expressed CYP1B1 is associated with attenuation of retinal endothelial cell (EC) capillary morphogenesis (CM) in vitro and angiogenesis in vivo. This was largely caused by increased intracellular oxidative stress and increased production of thrombospondin-2, an endogenous inhibitor of angiogenesis. Here, we demonstrate that endothelium nitric oxide synthase (eNOS) expression is dramatically decreased in the ECs prepared from retina, lung, heart, and aorta of CYP1B1-deficient (CYP1B1−/−) mice compared with wild-type (CYP1B1+/+) mice. The eNOS expression was also decreased in retinal vasculature of CYP1B1−/− mice. Inhibition of eNOS activity in cultured CYP1B1+/+ retinal ECs blocked CM and was concomitant with increased oxidative stress, like in CYP1B1−/− retinal ECs. In addition, expression of eNOS in CYP1B1−/− retinal ECs or their incubation with a nitric oxide (NO) donor enhanced NO levels, lowered oxidative stress, and improved cell migration and CM. Inhibition of CYP1B1 activity in the CYP1B1+/+ retinal ECs resulted in reduced NO levels and attenuation of CM. In contrast, expression of CYP1B1 increased NO levels and enhanced CM of CYP1B1−/− retinal ECs. Furthermore, attenuation of CYP1B1 expression with small interfering RNA proportionally lowered eNOS expression and NO levels in wild-type cells. Together, our results link CYP1B1 metabolism in retinal ECs with sustained eNOS activity and NO synthesis and/or bioavailability and low oxidative stress and thrombospondin-2 expression. Thus CYP1B1 and eNOS cooperate in different ways to lower oxidative stress and thereby to promote CM in vitro and angiogenesis in vivo.

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Nitric oxide-induced eosinophil apoptosis is dependent on mitochondrial permeability transition (mPT), JNK and oxidative stress: apoptosis is preceded but not mediated by early mPT-dependent JNK activation

Respiratory Research ◽

10.1186/1465-9921-13-73 ◽

2012 ◽

Vol 13 (1) ◽

pp. 73 ◽

Cited By ~ 13

Author(s):

Pinja Ilmarinen-Salo ◽

Eeva Moilanen ◽

Vuokko L Kinnula ◽

Hannu Kankaanranta

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Mitochondrial Permeability Transition ◽

Permeability Transition ◽

Mitochondrial Permeability ◽

Jnk Activation ◽

And Oxidative Stress ◽

Eosinophil Apoptosis

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The cyclophilin inhibitor NIM-811 increases muscle cell survival with hypoxia in vitro and improves gait performance following ischemia–reperfusion in vivo

Scientific Reports ◽

10.1038/s41598-021-85753-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Khairat Bahgat Youssef El Baradie ◽

Mohammad B. Khan ◽

Bharati Mendhe ◽

Jennifer Waller ◽

Frederick O’Brien ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Survival ◽

Reperfusion Injury ◽

Mitochondrial Permeability Transition ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Permeability Transition ◽

Mitochondrial Permeability

AbstractAcute ischemia–reperfusion injury in skeletal muscle is a significant clinical concern in the trauma setting. The mitochondrial permeability transition inhibitor NIM-811 has previously been shown to reduce ischemic injury in the liver and kidney. The effects of this treatment on skeletal muscle are, however, not well understood. We first used an in vitro model of muscle cell ischemia in which primary human skeletal myoblasts were exposed to hypoxic conditions (1% O2 and 5% CO2) for 6 h. Cells were treated with NIM-811 (0–20 µM). MTS assay was used to quantify cell survival and LDH assay to quantify cytotoxicity 2 h after treatment. Results indicate that NIM-811 treatment of ischemic myotubes significantly increased cell survival and decreased LDH in a dose-dependent manner. We then examined NIM-811 effects in vivo using orthodontic rubber bands (ORBs) for 90 min of single hindlimb ischemia. Mice received vehicle or NIM-811 (10 mg/kg BW) 10 min before reperfusion and 3 h later. Ischemia and reperfusion were monitored using laser speckle imaging. In vivo data demonstrate that mice treated with NIM-811 showed increased gait speed and improved Tarlov scores compared to vehicle-treated mice. The ischemic limbs of female mice treated with NIM-811 showed significantly lower levels of MCP-1, IL-23, IL-6, and IL-1α compared to limbs of vehicle-treated mice. Similarly, male mice treated with NIM-811 showed significantly lower levels of MCP-1 and IL-1a. These findings are clinically relevant as MCP-1, IL-23, IL-6, and IL-1α are all pro-inflammatory factors that are thought to contribute directly to tissue damage after ischemic injury. Results from the in vitro and in vivo experiments suggest that NIM-811 and possibly other mitochondrial permeability transition inhibitors may be effective for improving skeletal muscle salvage and survival after ischemia–reperfusion injury.

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Role of 70-kDa Ribosomal Protein S6 Kinase, Nitric Oxide Synthase, Glycogen Synthase Kinase-3β, and Mitochondrial Permeability Transition Pore in Desflurane-induced Postconditioning in Isolated Human Right Atria

Anesthesiology ◽

10.1097/aln.0b013e3181d74f39 ◽

2010 ◽

Vol 112 (6) ◽

pp. 1355-1363 ◽

Cited By ~ 9

Author(s):

Sandrine Lemoine ◽

Lan Zhu ◽

Gallic Beauchef ◽

Olivier Lepage ◽

Gérard Babatasi ◽

...

Keyword(s):

Nitric Oxide ◽

Methyl Ester ◽

Mitochondrial Permeability Transition Pore ◽

Mitochondrial Permeability Transition ◽

Permeability Transition Pore ◽

Permeability Transition ◽

S6 Kinase ◽

Mitochondrial Permeability ◽

Ribosomal Protein S6 ◽

Oxide Synthase

Background Desflurane during early reperfusion has been shown to postcondition human myocardium. Whether it involves "reperfusion injury salvage kinase" pathway remains incompletely studied. The authors tested the involvement of 70-kDa ribosomal protein S6 kinase, nitric oxide synthase, glycogen synthase kinase (GSK)-3beta, and mitochondrial permeability transition pore in desflurane-induced postconditioning. Methods The authors recorded isometric contraction of human right atrial trabeculae suspended in an oxygenated Tyrode's solution (34 degrees C, stimulation frequency 1 Hz). After a 30-min hypoxic period, desflurane 6% was administered during the first 5 min of reoxygenation. Desflurane was administered alone or with pretreatment of rapamycin, a 70-kDa ribosomal protein S6 kinase inhibitor, NG-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, and atractyloside, the mitochondrial permeability transition pore opener. GSK-3beta inhibitor VII was administered during the first few minutes of reoxygenation alone or in the presence of desflurane 6%, rapamycin, NG-nitro-L-arginine methyl ester, and atractyloside. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- SD). Phosphorylation of GSK-3beta was measured using blotting. Results Desflurane 6% (84 +/- 4% of baseline) enhanced the recovery of force after 60 min of reoxygenation when compared with the control group (54 +/- 4%, P < 0.0001). Rapamycin (68 +/- 8% of baseline), NG-nitro-L-arginine methyl ester (57 +/- 8%), atractyloside (52 +/- 7%) abolished desflurane-induced postconditioning (P < 0.001). GSK-3beta inhibitor-induced postconditioning (84 +/- 5%, P < 0.0001 vs. control) was not modified by desflurane (78 +/- 6%), rapamycin (81 +/- 6%), and NG-nitro-L-arginine methyl ester (82 +/- 10%), but it was abolished by atractyloside (49 +/- 6%). Desflurane increased the phosphorylation of GSK-3beta (3.30 +/- 0.57-fold increase in desflurane vs. control; P < 0.0001). Conclusions In vitro, desflurane-induced postconditioning protects human myocardium through the activation of 70-kDa ribosomal protein S6 kinase, nitric oxide synthase, inhibition, and phosphorylation of GSK-3beta, and preventing mitochondrial permeability transition pore opening.

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The Mitochondrial Permeability Transition Pore and Nitric Oxide Synthase Mediate Early Mitochondrial Depolarization in Astrocytes during Oxygen–Glucose Deprivation

Journal of Neuroscience ◽

10.1523/jneurosci.21-17-06608.2001 ◽

2001 ◽

Vol 21 (17) ◽

pp. 6608-6616 ◽

Cited By ~ 69

Author(s):

Susan A. Reichert ◽

Jeong Sook Kim-Han ◽

Laura L. Dugan

Keyword(s):

Nitric Oxide ◽

Mitochondrial Permeability Transition Pore ◽

Mitochondrial Permeability Transition ◽

Permeability Transition Pore ◽

Permeability Transition ◽

Glucose Deprivation ◽

Oxygen Glucose Deprivation ◽

Mitochondrial Depolarization ◽

Mitochondrial Permeability ◽

Oxide Synthase

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Selenite sensitizes mitochondrial permeability transition pore opening in vitro and in vivo: a possible mechanism for chemo-protection

Biochemical Journal ◽

10.1042/bj20021022 ◽

2003 ◽

Vol 370 (1) ◽

pp. 283-290 ◽

Cited By ~ 36

Author(s):

Shani SHILO ◽

Anna ARONIS ◽

Rita KOMARNITSKY ◽

Oren TIROSH

Keyword(s):

Complex I ◽

Mitochondrial Permeability Transition ◽

Permeability Transition ◽

Mitochondrial Swelling ◽

Rat Liver Mitochondria ◽

Mitochondrial Permeability ◽

Cellular Apoptosis ◽

Pore Opening

There is a known connection between selenium supplementation and chemo-protective anti-cancer activity. This biological phenomenon may be due to the ability of selenium to instigate cellular apoptosis. However, the mechanism by which selenium promotes cellular apoptosis is still obscure. The present study shows that sodium selenite, a common dietary form of selenium, promotes the mitochondrial permeability transition (MPT) in isolated rat liver mitochondria both in vitro and following in vivo supplementation. A low selenium concentration (0.1—10μM) strongly induced cyclosporin A-sensitive mitochondrial swelling. Selenium also promoted both calcium release from the matrix of isolated mitochondria and uncoupled respiration. The MPT-inducing effect of selenium provoked the release of cytochrome c, a pro-apoptotic factor, into the incubation medium. Selenium did not increase intra-mitochondrial peroxide production, but did consume endogenous mitochondrial glutathione. Moreover, the effect of MPT induction was greatly potentiated in the presence of thiol-bearing antioxidants, e.g. N-acetylcysteine and lipoamide. During MPT progression, selenium induced NADH oxidation via electron acceptance from complex I. Supplementation for 20 days with 16p.p.m. selenium in the drinking water of rats increased the propensity of mitochondria to undergo the MPT. More marked mitochondrial swelling in response to calcium and lower calcium-uptake capacity were observed, in the absence of liver damage or the intensive oxidation of reduced glutathione. Therefore selenite facilitates MPT pore opening via its thiol- and NADH/complex I-dependent reduction, and thereby may provide chemo-protection by potentiation of the capacity of the mitochondria to regulate programmed cell death. Data from the present study suggest that selenium can regulate important mitochondrial functions both in vivo and in vitro.

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