scholarly journals Mitochondrial ATP is required for the maintenance of membrane integrity in stallion spermatozoa, whereas motility requires both glycolysis and oxidative phosphorylation

Reproduction ◽  
2016 ◽  
Vol 152 (6) ◽  
pp. 683-694 ◽  
Author(s):  
M Plaza Davila ◽  
P Martin Muñoz ◽  
J M Gallardo Bolaños ◽  
T A E Stout ◽  
B M Gadella ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Sperm Motility ◽  
Mitochondrial Respiration ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Atp Content ◽  
Oligomycin A ◽  
Mitochondrial Uncouplers

To investigate the hypothesis that oxidative phosphorylation is a major source of ATP to fuel stallion sperm motility, oxidative phosphorylation was suppressed using the mitochondrial uncouplers CCCP and 2,4,-dinitrophenol (DNP) and by inhibiting mitochondrial respiration at complex IV using sodium cyanide or at the level of ATP synthase using oligomycin-A. As mitochondrial dysfunction may also lead to oxidative stress, production of reactive oxygen species was monitored simultaneously. All inhibitors reduced ATP content, but oligomycin-A did so most profoundly. Oligomycin-A and CCCP also significantly reduced mitochondrial membrane potential. Sperm motility almost completely ceased after the inhibition of mitochondrial respiration and both percentage of motile sperm and sperm velocity were reduced in the presence of mitochondrial uncouplers. Inhibition of ATP synthesis resulted in the loss of sperm membrane integrity and increased the production of reactive oxygen species by degenerating sperm. Inhibition of glycolysis by deoxyglucose led to reduced sperm velocities and reduced ATP content, but not to loss of membrane integrity. These results suggest that, in contrast to many other mammalian species, stallion spermatozoa rely primarily on oxidative phosphorylation to generate the energy required for instance to maintain a functional Na+/K+ gradient, which is dependent on an Na+-K+ antiporter ATPase, which relates directly to the noted membrane integrity loss. Under aerobic conditions, however, glycolysis also provides the energy required for sperm motility.

Activated Pancreatic Stellate Cells Promote Acinar Duct Metaplasia by Disrupting Mitochondrial Respiration and Releasing Reactive Oxygen Species

2021 ◽  
Vol 01 ◽  
Author(s):  
Hong Xiang ◽  
Fangyue Guo ◽  
Qi Zhou ◽  
Xufeng Tao ◽  
Deshi Dong
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Respiration ◽  
Reactive Oxygen ◽  
Acinar Cells ◽  
Stellate Cells ◽  
Pancreatic Fibrosis ◽  
Pancreatic Stellate Cells ◽  
Pancreatic Acinar Cells ◽  
Oxygen Species

Background: Chronic pancreatitis (CP) is a long-term risk factor for pancreatic ductal adenocarcinoma (PDAC), and both diseases share a common etiology. The activation of Pancreatic stellate cells (PaSCs) caused by inflammation of the chronic pancreas plays a pivotal role in the pathology of pancreatic fibrosis and the malignant phenotype of PDAC. However, the central role of activated PaSCs in acinar-to-ductal metaplasia (ADM) remains unknown. Objective: In the present study, we investigated the link between pancreatic fibrosis and ADM and the possible underlying mechanism. Methods: A caerulein-treated mouse CP model was established, and Masson trichrome histochemical stain and transmission electron microscope (TEM) were used to observe stromal fibrosis and cell ultrastructure, respectively. The expression of amylase and cytokeratin 19 (CK19), mitochondria respiration, and reactive oxygen species (ROS) were detected in vitro in the co-culture model of primary pancreatic acinar cells and PaSCs. Results: The activation of PaSCs and pancreatic fibrosis were accompanied by ADM in pancreatic parenchyma in caerulein-treated mice, which was verified by the co-cultivation experiment in vitro. Furthermore, we showed that activated PaSCs promote ADM by disrupting mitochondrial respiration and releasing ROS. The expression of inflammation-and ADM-related genes, including S100A8, S100A9, and CK19, was observed to be up-regulated in pancreatic acinar cells in the presence of activated PaSCs. The expression of S100A9 and CK19 proteins was also up-regulated in acinar cells co-cultured with activated PaSCs. Conclusion: The manipulation of mitochondrial respiration and ROS release is a promising preventive and/or therapeutic strategy for PDAC, and S100A9 is expected to be a therapeutic target to block the ADM process induced by the activation of PaSCs.

69 REACTIVE OXYGEN SPECIES EVALUATION OF DONKEY FROZEN SEMEN ADDED TO HOMOLOGOUS SEMINAL PLASMA ON POST-THAW

2015 ◽  
Vol 27 (1) ◽  
pp. 127
Author(s):  
P. V. L. Oliveira ◽  
J. V. Oliveira ◽  
C. Ramires Neto ◽  
Y. F. R. Sancler-Silva ◽  
C. P. Freitas-Dell'aqua ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Kinetic Parameters ◽  
Seminal Plasma ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Computer Assisted ◽  
Oxygen Species ◽  
Inflammation Response ◽  
Frozen Semen ◽  
Uterine Inflammation

For many years the pregnancy rate of donkey frozen semen presented lower results in donkey jennies; however, a recent study showed an increase in pregnancy rates using frozen semen added to seminal plasma on post-thaw. A hypothesis for this result is the higher uterine inflammation response after breeding when using seminal plasma. The same studies demonstrated higher uterine inflammation in the presence of higher reactive oxygen species concentration. The aim of the present study was to evaluate the content of reactive oxygen species in donkey frozen semen added to homologous seminal plasma on post-thaw. Five ejaculates from each 3 donkeys were used. Semen was diluted (1 : 1) with a skim milk-based extender (Botu-SemenTM, Botupharma, Brazil). The semen was frozen with Botu-CryoTM extender (Botupharma, Brazil) in an isothermal box in straws containing 100 × 106 of total sperm. The samples were thawed at 46°C for 20 s. After this, the straws of each donkey were divided in 2 group: control group (CG), in which the semen was incubated at 37°C for 5 min, and plasma seminal group (PG), in which the semen was incubated at 37°C for 5 min with 70% of homologous seminal plasma. Sperm kinetic parameters were evaluated by computer-assisted semen analysis, and the plasma membrane integrity (propidium iodide and fluorescein isothiocyanate -PSA) and reactive oxygen species (5–6-carboxi-2,7-diclorodihidrofluoresceindiacetate) were evaluated by flow cytometer. Comparison of sperm parameters was performed by t-test. Total motility (%, CG = 75.4 ± 8.2a v. PG = 57.5 ± 16.4b), progressive motility (%, CG = 42.0 ± 8.7a v. PG = 33.3 ± 13.2b), progressive angular velocity (μm/s, CG = 95.8 ± 10.8a v. PG = 88.9 ± 10.9b), and percentage of rapid sperm (%, CG = 58.4 ± 12.5a v. PG = 41.0 ± 17.3b) were higher in CG compare with PG. No difference (P < 0.05) was observed in membrane integrity (%, CG = 20.7 ± 7.4 v. PG = 20.6 ± 7.8); however, reactive oxygen species (%, CG = 12.3 ± 10.6a v. PG = 81.8 ± 32.5b) were higher in PG. The results of this study showed that the addition of homologous seminal plasma on post-thaw decreases the sperm kinetic parameters and viability of donkey frozen semen but increases reactive oxygen species, and this may cause higher uterine inflammation response in donkey jennies and increase their fertility.

Effect of endotoxin-induced reactive oxygen species on sperm motility

2001 ◽  
Vol 76 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Kenichiro Urata ◽  
Hisashi Narahara ◽  
Yuichiro Tanaka ◽  
Toru Egashira ◽  
Fusako Takayama ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Sperm Motility ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals Trolox-Sensitive Reactive Oxygen Species Regulate Mitochondrial Morphology, Oxidative Phosphorylation and Cytosolic Calcium Handling in Healthy Cells

2012 ◽  
Vol 17 (12) ◽  
pp. 1657-1669 ◽  
Author(s):  
Felix Distelmaier ◽  
Federica Valsecchi ◽  
Marleen Forkink ◽  
Sjenet van Emst-de Vries ◽  
Herman G. Swarts ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Reactive Oxygen ◽  
Cytosolic Calcium ◽  
Calcium Handling ◽  
Mitochondrial Morphology ◽  
Oxygen Species

scholarly journals Mitochondria, oxidative stress and aging

2014 ◽  
Vol 155 (12) ◽  
pp. 447-452
Author(s):  
András Szarka ◽  
Gábor Bánhegyi ◽  
Balázs Sümegi
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Dna ◽  
Mitochondrial Respiration ◽  
Accelerated Aging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Vicious Cycle ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Theory Of Aging

The free radical theory of aging was defined in the 1950s. On the base of this theory, the reactive oxygen species formed in the metabolic pathways can play pivotal role in ageing. The theory was modified by defining the mitochondrial respiration as the major cellular source of reactive oxygen species and got the new name mitochondrial theory of aging. Later on the existence of a “vicious cycle” was proposed, in which the reactive oxygen species formed in the mitochondrial respiration impair the mitochondrial DNA and its functions. The formation of reactive oxygen species are elevated due to mitochondrial dysfunction. The formation of mitochondrial DNA mutations can be accelerated by this “vicious cycle”, which can lead to accelerated aging. The exonuclease activity of DNA polymerase γ, the polymerase responsible for the replication of mitochondrial DNA was impaired in mtDNA mutator mouse recently. The rate of somatic mutations in mitochondrial DNA was elevated and an aging phenotype could have been observed in these mice. Surprisingly, no oxidative impairment neither elevated reactive oxygen species formation could have been observed in the mtDNA mutator mice, which may question the existence of the “vicious cycle”. Orv. Hetil., 2014, 155(12), 447–452.

Reactive Oxygen Species and RBC Membrane Integrity in Peroxyredoxin II Deficient Mice.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 54-54
Author(s):  
Amrita Bhagat ◽  
Renee Emerson ◽  
Kitty DeJong ◽  
Frans A. Kuypers
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Properties ◽  
Flow Cytometric Analysis ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Extinction Time ◽  
Oxygen Species ◽  
Rbc Membrane ◽  
Small Proteins ◽  
Phospholipid Scrambling

Abstract Red blood cells (RBCs) contain a complex set of enzymes and non-enzymatic scavengers as defense against reactive oxygen species (ROS). Peroxiredoxin II (PrxII), a member of a family of small proteins with strong antioxidant properties, is highly abundant in RBCs. PrxII is likely to play an essential role in ROS protection, as RBCs generate high levels of ROS due to their role in oxygen transport and the presence of redox active hemoglobin. Phosphatidylserine (PS) asymmetry in RBCs is maintained by the active transport of PS from outer to inner monolayer by the oxidant sensitive aminophospholipid translocase or flipase. PS exposure is found in RBCs where phospholipid scrambling is activated and the flipase is inhibited. In PrxII−/− mice, PrxII is absent from the RBC. These mice are anemic (Hct 41% vs. 46% in wild type mice (WT)), with increased reticulocyte count (4.7% vs. 2.0 % in WT), and a morphologically diverse RBC population. RBC indices after isovolumetric sphering showed a similar MCH (14.3 vs. 14.2), slightly increased MCV (49.2 fl vs. 45.5 fl) and slightly decreased MCHC (30.1 vs. 32.1) in PrxII−/− mice as compared to WT. In flow cytometric analysis, two distinct populations of RBC are found with either slight or significantly increased autofluorescence in the fluorescein channel (excitation 488 nm, emission 515 nm), indicative of oxidant damage. These two populations of low (LF) and high (HF) fluorescent cells comprise 70–80% and 20–30% of the total RBC population respectively. RBC from PrxII−/− and WT mice were biotinylated using EZ-Link Sulfo-NHS-Biotin (Pierce) allowing turnover studies of the LF and HF population. At set time points, the number of biotinylated cells was determined in small blood samples by flow cytometry using fluorescently labeled streptavidin. The data were mathematically fitted to 100–100*[1−(1/T)*t]exp(−kt), where t is the time point, T is the extinction time, and k the exponential rate of RBC removal. The data in the WT showed a linear removal rate (k=0), and a T of 40 days (R2=0.99). In PrxII−/−, an overall faster disappearance of biotinylated cells was noted, and the number of surviving (biotinylated) cells in the population followed an exponential pattern, consistent with random removal (k=0.08, R2= 0.98). At 20 days, 50% of biotinylated RBC were present in WT, but only 18% were found in PrxII−/− mice. In the non-biotinylated RBC, HF cells started to appear at day 13, indicating that autofluorescence is acquired in time. Using the fluorescent ROS membrane probe C11-BODIPY, our data indicate a higher level of ROS in the HF population. The HF population exhibited a lower flipase activity and increased phospholipid scrambling, as measured by labeling with annexin V. Together, our data indicate the importance of PrxII in the maintenance of RBC membrane integrity and suggest that oxidant induced PS exposure is in part responsible for shortened RBC survival in these mice. These findings indicate a role for oxidation in the exposure of PS on the RBC surface, which may clarify mechanisms in oxidant induced membrane alterations in hemoglobinopathies.

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