317 EFFECT OF REACTIVE OXYGEN SPECIES (ROS) ON ACTIVATION OF BOVINE OOCYTES MATURED IN VITRO

2006 ◽  
Vol 18 (2) ◽  
pp. 266 ◽  
Author(s):  
J. I. Park ◽  
Y. Jang ◽  
E. S. Lee

Vitamin E is an antioxidant that protects embryos from oxidative stress and supports embryonic development in vitro. This study was carried out to assess the effect of reactive oxygen species (ROS) by measuring the effects of hydrogen peroxide (H2O2) and vitamin E (VitE) on chemical activation of in vitro-matured oocytes. Bovine ovaries were collected from slaughtered cows at a local abattoir. Oocytes were aspirated from follicles 3-8 mm in diameter and transferred to maturation medium: tissue culture medium (TCM)-199 supplemented with 10% (v/v) fetal calf serum, 100 mg/L-cysteinr, 44 mg/L sodium pyruvate, gonadotropins (each 250 IU of eCG and hCG/mL), and 10 ng/mL epidermal growth factor. Oocytes were cultured at 38.9�C in 5% CO2 in humidified air. After 22 h of culture, oocytes with polar bodies were selected and submitted to activation treatments. Oocytes were exposed to calcium ionomycin (5 �M for 5 min) followed by incubation with 6-DMAP (2 mM) for 3.5 h in medium supplemented with or without VitE (100 �m). Routine in vitro fertilization (IVF) was also performed for 18 h as control treatment with or without VitE. After activation, oocytes were cultured in mSOF medium containing 0.8% BSA at 38.9�C in 5% CO2, 5% O2 in humidified air for 16-18 h. H2O2 content was measured and rate of development was monitored. For detection of H2O2, individual oocytes were stained with 22,72-dichlorofluorescein diacetate (DCFDA) and observed under fluorescence microscope (Hashimoto et al. 2000 Mol. Reprod. Dev. 56, 520-526). Levels of H2O2 were analyzed by counting the number of black-white pixels of TIFF images (ImageJ ver. 1.32; http://rsb.info.nih.gov/ij) after conversion of fluorescence image. Data were analyzed using Student's t-test and chi-square test. The H2O2 contents were significantly higher (P < 0.05) in the activation group without VitE (218 pixels, n = 49) than IVF without VitE (210 pixels, n = 50). Levels of H2O2 in oocytes activated with VitE were also higher (P < 0.05) than in the IVF group with VitE (216 pixels, n = 50 vs. 210 pixels, n = 51). Between groups with or without VitE, the H2O2 contents were not different in both activation and IVF. The cleavage rate to the 2-cell stage and development rate to blastocysts after activation with VitE (77.8% and 15.1%, n = 72) were significantly higher (P < 0.05) than in those without VitE (63.3% and 10.2%, n = 60). The results of the present study demonstrate that the chemical activation increased accumulation of H2O2 in oocytes compared to the IVF condition. Although ROS level did not affect chemical activation, vitamin E added in the activation medium promoted further development of activated embryos. This work was supported by a grant from the BioGreen 21 Program (20050301-034-443-026-03-00), Rural Development Administration, Korea.

2007 ◽  
Vol 19 (1) ◽  
pp. 283
Author(s):  
J. I. Park ◽  
Y. Jang ◽  
E. S. Lee

Oxidative stress is known to induce apoptotic cell death by reactive oxygen species (ROS) generated from in vitro culture systems. This study was conducted to evaluate the effect of Vitamin E (VitE), as antioxidant, on development of bovine embryos activated in vitro. Bovine ovaries were collected from slaughtered cows at a local abattoir. Oocytes were aspirated from follicles 3-8 mm in diameter and transferred to maturation medium: tissue culture medium (TCM)-199 supplemented with 10% (v/v) fetal calf serum, 100 mg/mL-1 l-cysteine, 20 mg/mL-1 sodium pyruvate, gonadotropins (250 IU each of eCG and hCG/mL), 10 mg/mL-1 epidermal growth factor, and 100 �M VitE. Oocytes were cultured at 38.9�C in 5% CO2 in humidified air. After 22 hours of culture, oocytes with polar bodies were selected and subjected to activation treatments. Oocytes were exposed to calcium ionomycin (5 �M for 5 min), followed by incubation with 6-DMAP (2 mM) for 3.5 hours in medium supplemented with or without VitE (100 �M). After activation, oocytes were cultured in mSOF medium containing 0.8% BSA at 38.9�C in 5% CO2, 5% O2 in humidified air for 7–8 days. Cell numbers were counted by the number of nuclei of blastocysts stained with Hoechst 33342, and apoptosis was detected by TUNEL assay using a MK500 kit (Takara Bio, Inc., Otsu, Shiga, Japan). Total cell and apoptotic cell number were determined under a fluorescence microscope. Data were analyzed using Student&apos;s t-test and chi-square test. The cleavage and blastocyst rates were significantly higher (P &lt; 0.05) after activation with VitE (78.1&percnt; and 16.3&percnt;, n &equals; 80) than without VitE (66.7&percnt; and 11.0&percnt;, n &equals; 60). Total cell numbers were also significantly higher (P &lt; 0.05) in blastocysts after activation with VitE (143.0 &plusmn; 34.02, n &equals; 21) than in those without VitE (127.63 &plusmn; 40.25, n &equals; 20). However, the percentage of TUNEL-positive (apoptotic) cells was similar between blastocysts activated with VitE (5.38 &plusmn; 2.22) and those without VitE (6.76 &plusmn; 1.98). The results of the present study demonstrate that vitamin E added to activation medium promoted further development of activated embryos, although its role in the alleviation of apoptosis remains unclear.


2017 ◽  
Vol 29 (1) ◽  
pp. 146
Author(s):  
D. Le Bourhis ◽  
M. Verachten ◽  
P. Salvetti ◽  
M. Hochet ◽  
L. Schibler

The objective of the present study was to determine the effect of supplementation of culture medium with carnosine (β-alanyl-l-histidine; Sigma, St-Quentin Fallavier, France), a reactive oxygen species scavenger, on in vitro bovine embryo development and survival following cryopreservation. Abattoir-derived bovine oocytes (4 replicates) were in vitro matured and fertilized with frozen-thawed semen of one bull, according to our standard procedures. In Experiment 1, 20 h after IVF, groups of presumptive zygotes were cultured in 30 μL of SOF BSAaa + 1% oestrus cow serum with 0 (control; n = 205) or 5 μg mL−1 of carnosine (n = 209) under humidified air with 5% CO2, 5% O2, and 88% N2. Cleavage rates were determined on Day 2, and the blastocyst rates and grade were assessed on Day 7 according to IETS classification. Day 7 grade 1 expanded blastocysts (n = 25 control and n = 27 carnosine) were frozen in 1.5 M ethylene glycol + 0.1 M sucrose. Embryos were thawed and then cultured for 72 h in SOF-BSAaa + 1% oestrus cow serum for re-expansion and hatching rate assessments at +24 h, +48 h, and +72 h post-thawing. In Experiment 2, presumed zygotes were cultured in SOF BSAaa + 1% oestrus cow serum with 0 (control; n = 48) or 5 μg mL−1 of carnosine (n = 48) in a WOW dish and observed with Time Laps Cinematography (Primo Vision®, VitroLife, Göteborg, Sweden). Images were recorded every 15 min for up to 168 h post-insemination. For embryos that reached the blastocyst stage, mean timing of the first cleavage (C1; 2-cell stage), second cleavage (C2; 4-cell stage), second cleavage to compaction (C3), and blastocoel cavity appearance (B4) were recorded. Chi-square test for Experiment 1 and Student’s t-test for Experiment 2 were used, and differences were considered significant at P < 0.05. In Experiment 1, no differences were observed in cleavage rate, blastocyst rate on Day 7, and grade 1 blastocyst rate between both control and carnosine groups (84.0 ± 4.2 v.85.2 ± 3.8, P = 0.7; 46.9 ± 7.1 v. 45.0 ± 7.5, P = 0.7; 24.1 ± 2.0 v. 24.0 ± 6.5, P = 0.6; respectively). After thawing, the re-expansion at +24 h was not different between groups (74.1 v. 48.0% for carnosine and control groups, respectively; P = 0.06). However, at +48 h and +72 h, the survival rate of carnosine treated blastocysts was significantly higher than that of blastocysts in the control group: 70.4 ± 4.5% v. 40.0 ± 3.8% and 59.3 ± 3.8% v. 24.0 ± 3.6%, respectively. Results from Experiment 2 indicated no difference between control and carnosine groups for C1 (32.1 ± 3.9 v. 33.8 ± 6.1; P = 0.3), C2 (8.2 ± 8.9 v. 8.9 ± 0.9; P = 0.07), and B4 (147.0 ± 9.5 v. 145.4 ± 11.6; P = 0.6), whereas C3 was significantly different within groups: 59.9 ± 9.6 v. 51.8 ± 6.7 (P = 0.008). In conclusion, bovine blastocysts derived from zygotes cultured in the presence of 5 μg mL−1 carnosine possess a significantly faster kinetic from 4-cell stage to compaction and show a higher post-thawing viability. However, further analyses are still needed to clarify the relationship between the reactive oxygen species intracellular levels after carnosine treatment and in vitro bovine embryo quality. This work was supported by FECUND European project (grant agreement number 312097).


Author(s):  
Matteo Duque Rodriguez ◽  
Camila O. Cittadini ◽  
Gabriela M. Teplitz ◽  
Adrian De Stefano ◽  
Daniel M. Lombardo ◽  
...  

Assisted reproductive technologies in canine species are limited due to the low efficiency of in vitro maturation (IVM). Unlike other mammals, bitches ovulate oocytes in the germinal vesicle stage and complete metaphase II (MII) after 48–72 h in the oviductal environment and become fertilizable. For this reason, we compared two different IVM media, synthetic oviductal fluid (SOF) supplemented with 8% bovine serum albumin (BSA) or a mixture of 8% BSA–2.5% fetal bovine serum (FBS) and TCM-199 with 10% FBS. Additionally, we evaluated the effect of supplementation with insulin-transferrin-selenium (ITS) and low O2 tension in oocyte maturation, reactive oxygen species (ROS) levels, membrane integrity, and embryo development following parthenogenetic activation (PA). After 72 h of culture, SOF + BSA, SOF + BSA + FBS, and TCM-199 + FBS show 5, 7, and 4% of MII, respectively, without a statistical difference. However, SOF + BSA produced significantly higher degeneration rates compared to SOF + BSA + FBS (44 and 23%, respectively). Remarkably, supplementation with 1 μl/ml of ITS under high O2 tension demonstrated a beneficial effect by improving maturation rates up to 20% compared to the other groups. Low O2 tension increased maturation rates to 36.5%, although there were no statistical differences compared to high O2 tension in the presence of ITS. Lower ROS levels and higher integrity of the cytoplasmic membrane were found in the presence of ITS despite no differences in maturation rates under low O2 tension groups. Additionally, after PA, 1% development until the eight-cell stage was obtained after activation of in vitro-matured oocytes in the presence of ITS. Taken together, these results indicate that SOF supplemented with 8% BSA and 2.5% FBS is suitable for IVM of canine oocytes and ITS supplementation was beneficial for both high and low O2 tension. Furthermore, the addition of ITS in the cultured system lowers ROS levels and increases membrane integrity in domestic dog oocytes after IVM.


Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 388
Author(s):  
Xiao Dan Hui ◽  
Gang Wu ◽  
Duo Han ◽  
Xi Gong ◽  
Xi Yang Wu ◽  
...  

In this study, blueberry and blackcurrant powder were chosen as the phenolic-rich enrichments for oat bran. A Rapid Visco Analyser was used to form blueberry and blackcurrant enriched oat pastes. An in vitro digestion process evaluated the changes of phenolic compounds and the in vitro antioxidant potential of extracts of pastes. The anthocyanidin profiles in the extracts were characterised by the pH differential method. The results showed that blueberry and blackcurrant powder significantly increased the content of phenolic compounds and the in vitro antioxidant capacity of pastes, while the total flavonoid content decreased after digestion compared to the undigested samples. Strong correlations between these bioactive compounds and antioxidant values were observed. Lipopolysaccharide-stimulated RAW264.7 macrophages were used to investigate the intracellular antioxidant activity of the extracts from the digested oat bran paste with 25% enrichment of blueberry or blackcurrant powder. The results indicated that the extracts of digested pastes prevented the macrophages from experiencing lipopolysaccharide (LPS)-stimulated intracellular reactive oxygen species accumulation, mainly by the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway. These findings suggest that the bioactive ingredients from blueberry and blackcurrant powder enhanced the in vitro and intracellular antioxidant capacity of oat bran pastes, and these enriched pastes have the potential to be utilised in the development of the functional foods.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhuochao Liu ◽  
Hongyi Wang ◽  
Chuanzhen Hu ◽  
Chuanlong Wu ◽  
Jun Wang ◽  
...  

AbstractIn this study, we identified the multifaceted effects of atezolizumab, a specific monoclonal antibody against PD-L1, in tumor suppression except for restoring antitumor immunity, and investigated the promising ways to improve its efficacy. Atezolizumab could inhibit the proliferation and induce immune-independent apoptosis of osteosarcoma cells. With further exploration, we found that atezolizumab could impair mitochondria of osteosarcoma cells, resulting in increased release of reactive oxygen species and cytochrome-c, eventually leading to mitochondrial-related apoptosis via activating JNK pathway. Nevertheless, the excessive release of reactive oxygen species also activated the protective autophagy of osteosarcoma cells. Therefore, when we combined atezolizumab with autophagy inhibitors, the cytotoxic effect of atezolizumab on osteosarcoma cells was significantly enhanced in vitro. Further in vivo experiments also confirmed that atezolizumab combined with chloroquine achieved the most significant antitumor effect. Taken together, our study indicates that atezolizumab can induce mitochondrial-related apoptosis and protective autophagy independently of the immune system, and targeting autophagy is a promising combinatorial approach to amplify its cytotoxicity.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 936
Author(s):  
Olga Witkowska-Piłaszewicz ◽  
Rafał Pingwara ◽  
Jarosław Szczepaniak ◽  
Anna Winnicka

Clenbuterol, the β2-adrenoceptor agonist, is gaining growing popularity because of its effects on weight loss (i.e., chemical liposuction). It is also popular in bodybuilding and professional sports, due to its effects that are similar to anabolic steroids. However, it is prohibited by anti-doping control. On the other hand, it is suggested that clenbuterol can inhibit the inflammatory process. The cells from 14 untrained and 14 well-trained race horses were collected after acute exercise and cultured with clenbuterol. The expressions of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reactive oxygen species (ROS) production, as well as cell proliferation, were evaluated by flow cytometry. In addition, IL-1β, IL-4, IL-6, IL-10, IL-17, INF-γ and TNF-α concentrations were evaluated by ELISA. β2-adrenoceptor stimulation leads to enhanced anti-inflammatory properties in well-trained horses, as do low doses in untrained animals. In contrast, higher clenbuterol doses create a pro-inflammatory environment in inexperienced horses. In conclusion, β2-adrenoceptor stimulation leads to a biphasic response. In addition, the immune cells are more sensitive to drug abuse in inexperienced individuals under physical training.


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