Requirement of Low Oxygen Tension for Adaptation of a New Isolate of Plasmodium falciparum to Continuous In vitro Culture

1987 ◽  
Vol 73 (1) ◽  
pp. 238 ◽  
Author(s):  
Takao Takagi ◽  
Seiji Waki
Keyword(s):  
Plasmodium Falciparum ◽  
In Vitro Culture ◽  
Oxygen Tension ◽  
Low Oxygen ◽  
Low Oxygen Tension

247 EFFECTS OF CYSTEINE IN IVM MEDIA ON IN VITRO MATURATION UNDER LOW OXYGEN TENSION, IN VITRO FERTILIZATION, AND IN VITRO CULTURE OF PORCINE OOCYTES

2008 ◽  
Vol 20 (1) ◽  
pp. 203
Author(s):  
N. V. Linh ◽  
D. N. Q. Thanh ◽  
M. Ozawa ◽  
B. X. Nguyen ◽  
K. Kikuchi ◽  
...  
Keyword(s):  
Oxygen Tension ◽  
Blastocyst Stage ◽  
Low Oxygen ◽  
In Vitro Production ◽  
Vitro Fertilization ◽  
Nuclear Maturation ◽  
Low Oxygen Tension ◽  
High O2 ◽  
Group 1

Cysteine is considered to promote male pronuclear (MPN) formation in porcine through oocyte glutathione (GSH) synthesis (Yoshida et al. 1993 Biol. Reprod. 49, 89–94). The GSH has an important role in providing cells with a redox state and in acting to protect cells from toxic effects of oxidative damage (Meister et al. 1976 AM Rev. Biochem. 45, 559–604). However, such previous investigations were carried out under high O2 tension (20% O2) incubation conditions. Here we simply study IVM-IVF-IVC competence of porcine oocytes matured in IVM media supplemented with cysteine of different concentrations under low oxygen tension (5% O2). Cumulus–oocyte complexes (COCs) from prepubertal gilts were collected, matured, and fertilized in vitro according to Kikuchi et al. (2000 Biol. Reprod. 66, 1033–1041). COCs were cultured in IVM medium supplemented with 0 (Group 1; control), 0.05 (Group 2), 0.1 (Group 3), 0.2 (Group 4), and 0.6 mm (Group 5) cysteine under low oxygen tension. Nuclear maturation of oocytes, fertilization status, and number of cells in resultant embryos were assessed with orcein staining; also, the GSH content of IVM oocytes was measured by the method described by Ozawa et al. (2002 Reproduction 124, 683–689). Maturation rates of Groups 1–5 were 68.2 � 3.2, 70.6 � 7.7, 69.7 � 15.9, 75.9 � 7.7, and 68.8 � 8.0%, respectively, indicating no difference in maturation competence among the groups (P > 0.05 by ANOVA). The rates of sperm penetration, MPN formation (95.9 � 2.4, 100 � 0, 92.8 � 4.7, 94.0 � 4.1, and 92.4 � 2.7%, respectively), monospermy, and even blastocyst rates after 6 days of IVC were not different among the groups (P > 0.05 by ANOVA). Moreover, the cell numbers of blastomeres in blastocysts (38.68 � 3.5, 40.1 � 3.1, 37.5 � 3.0, 36.2 � 3.3, and 43.8 � 4.0, respectively) were uniformly the same among the groups (P > 0.05 by ANOVA). However, GSH content of IVM oocytes increased significantly (P < 0.05 by ANOVA) as the concentration of cysteine increased (12.2 � 0.6, 14 � 0.8, 15.1 � 0.5, 16.4 � 0.4, and 16.4 � 0.5 pmol/oocyte, respectively). The GSH level of oocytes in Group 1 (control) seems to be higher than that reported by Aberydeera et al. (1998 Biol. Reprod. 58, 213–218), who matured porcine oocytes under high O2 tension. This may reflect the effect of low O2 tension and explain the same developmental rate to the blastocyst stage as that of oocytes matured in the media supplemented with cysteine in this study. In conclusion, an addition of 0.05–0.6 mm cysteine during IVM, under 5% O2 tension, of porcine oocytes significantly increased intracellular GSH synthesis according to its concentration. However, it had no promoting effects on nuclear maturation, fertilization, male pronucleus formation, and subsequent embryonic development to the blastocyst stage. Thus, O2 tension during IVM of oocytes is suggested to be important for the in vitro production of porcine blastocysts.

Embryo culture at a reduced oxygen concentration of 5%: a mini review

Zygote ◽  
2019 ◽  
Vol 27 (6) ◽  
pp. 355-361 ◽  
Author(s):  
R. Sciorio ◽  
G.D. Smith
Keyword(s):  
Oxygen Tension ◽  
Embryo Development ◽  
Atmospheric Oxygen ◽  
Embryo Implantation ◽  
Critical Role ◽  
Low Oxygen ◽  
Physiological Level ◽  
Low Oxygen Tension

SummaryThe optimum oxygen tension for culturing mammalian embryos has been widely debated by the scientific community. While several laboratories have moved to using 5% as the value for oxygen tension, the majority of modern in vitro fertilization (IVF) laboratory programmes still use 20%. Several in vivo studies have shown the oxygen tension measured in the oviduct of mammals fluctuates between 2% and 8% and in cows and primates this values drops to <2% in the uterine milieu. In human IVF, a non-physiological level of 20% oxygen has been used in the past. However, several studies have shown that atmospheric oxygen introduces adverse effects to embryo development, not limited to numerous molecular and cellular physiology events. In addition, low oxygen tension plays a critical role in reducing the high level of detrimental reactive oxygen species within cells, influences embryonic gene expression, helps with embryo metabolism of glucose, and enhances embryo development to the blastocyst stage. Collectively, this improves embryo implantation potential. However, clinical studies have yielded contradictory results. In almost all reports, some level of improvement has been identified in embryo development or implantation, without any observed drawbacks. This review article will examine the recent literature and discusses ongoing efforts to understand the benefits that low oxygen tension can bring to mammal embryo development in vitro.

scholarly journals Inability of Low Oxygen Tension to Induce Chondrogenesis in Human Infrapatellar Fat Pad Mesenchymal Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Samia Rahman ◽  
Alexander R. A. Szojka ◽  
Yan Liang ◽  
Melanie Kunze ◽  
Victoria Goncalves ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Oxygen Tension ◽  
Endochondral Ossification ◽  
Infrapatellar Fat Pad ◽  
Low Oxygen ◽  
Fat Pad ◽  
Chondrogenic Medium ◽  
Low Oxygen Tension

ObjectiveArticular cartilage of the knee joint is avascular, exists under a low oxygen tension microenvironment, and does not self-heal when injured. Human infrapatellar fat pad-sourced mesenchymal stem cells (IFP-MSC) are an arthroscopically accessible source of mesenchymal stem cells (MSC) for the repair of articular cartilage defects. Human IFP-MSC exists physiologically under a low oxygen tension (i.e., 1–5%) microenvironment. Human bone marrow mesenchymal stem cells (BM-MSC) exist physiologically within a similar range of oxygen tension. A low oxygen tension of 2% spontaneously induced chondrogenesis in micromass pellets of human BM-MSC. However, this is yet to be demonstrated in human IFP-MSC or other adipose tissue-sourced MSC. In this study, we explored the potential of low oxygen tension at 2% to drive the in vitro chondrogenesis of IFP-MSC. We hypothesized that 2% O2 will induce stable chondrogenesis in human IFP-MSC without the risk of undergoing endochondral ossification at ectopic sites of implantation.MethodsMicromass pellets of human IFP-MSC were cultured under 2% O2 or 21% O2 (normal atmosphere O2) in the presence or absence of chondrogenic medium with transforming growth factor-β3 (TGFβ3) for 3 weeks. Following in vitro chondrogenesis, the resulting pellets were implanted in immunodeficient athymic nude mice for 3 weeks.ResultsA low oxygen tension of 2% was unable to induce chondrogenesis in human IFP-MSC. In contrast, chondrogenic medium with TGFβ3 induced in vitro chondrogenesis. All pellets were devoid of any evidence of undergoing endochondral ossification after subcutaneous implantation in athymic mice.

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