The Experts below are selected from a list of 1635 Experts worldwide ranked by ideXlab platform
Naomi Nakagata - One of the best experts on this subject based on the ideXlab platform.
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Reduced Glutathione Enhances Fertility of Frozen/Thawed C57BL/6 Mouse Sperm after Exposure to Methyl-Beta-Cyclodextrin Short title: Glutathione facilitates fertilization in mice Summary sentence: Adding reduced glutathione to in vitro fertilization m
2020Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, which is the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In this study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida by induced by reduced glutathione. Results showed that adding reduced glutathione to the fertilization medium increased the fertilization rate. We found that Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, two-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse
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fertility of cold stored mouse sperm is recovered by promoting acrosome reaction and hyperactivation after cholesterol efflux by Methyl Beta Cyclodextrin
Biology of Reproduction, 2017Co-Authors: Hidetaka Yoshimoto, Toru Takeo, Tetsumi Irie, Naomi NakagataAbstract:: Cold storage of the cauda epididymis, a male reproductive organ, is an efficient means of transporting genetically modified mice, an alternative to live animal shipment. The fertility of cold-stored sperm decreases in a time-dependent manner. However, the cause of the reduction in the fertility of sperm after cold storage remains unclear. It is known that cholesterol efflux from the sperm membrane is a trigger of capacitation. The dysfunction of cholesterol efflux due to changes in the membrane state in low temperatures may explain the reduced fertility. In this study, we examined the fertility (fertilization rate, acrosome reaction, and motility) and the amount of cholesterol and membrane fluidity in cold-stored sperm after treatment with two cholesterol acceptors, bovine serum albumin (BSA), and Methyl-Beta-Cyclodextrin (MBCD). MBCD-treated sperm exhibited the highest rate of fertilization. Two-cell embryos derived from in vitro fertilization using 0.75-mM-MBCD-treated sperm after cold storage for 72 h developed to offspring. MBCD also displayed greater ability to remove cholesterol from the sperm membrane than BSA. The percentage of viable sperm with membrane destabilization was increased by MBCD in cold-stored sperm. The acrosome reaction strongly occurred in MBCD-treated sperm. In motility analysis, MBCD improved the lateral amplitude of head movement and beat frequency. These results suggest that MBCD-induced cholesterol efflux enhances membrane fluidity and promotes acrosome reaction and hyperactivation, resulting in improved fertility of cold-stored sperm.
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reduced glutathione enhances fertility of frozen thawed c57bl 6 mouse sperm after exposure to Methyl Beta Cyclodextrin
Biology of Reproduction, 2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, 2-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse sperm.
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Reduced Glutathione Enhances Fertility of Frozen/Thawed C57BL/6 Mouse Sperm after Exposure to Methyl-Beta-Cyclodextrin
Biology of Reproduction, 2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-Beta-cycl...
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reduced glutathione enhances fertility of frozen thawed c57bl 6 mouse sperm after exposure to Methyl Beta Cyclodextrin short title glutathione facilitates fertilization in mice summary sentence adding reduced glutathione to in vitro fertilization med
2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, which is the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In this study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida by induced by reduced glutathione. Results showed that adding reduced glutathione to the fertilization medium increased the fertilization rate. We found that Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, two-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse
Toru Takeo - One of the best experts on this subject based on the ideXlab platform.
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Reduced Glutathione Enhances Fertility of Frozen/Thawed C57BL/6 Mouse Sperm after Exposure to Methyl-Beta-Cyclodextrin Short title: Glutathione facilitates fertilization in mice Summary sentence: Adding reduced glutathione to in vitro fertilization m
2020Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, which is the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In this study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida by induced by reduced glutathione. Results showed that adding reduced glutathione to the fertilization medium increased the fertilization rate. We found that Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, two-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse
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fertility of cold stored mouse sperm is recovered by promoting acrosome reaction and hyperactivation after cholesterol efflux by Methyl Beta Cyclodextrin
Biology of Reproduction, 2017Co-Authors: Hidetaka Yoshimoto, Toru Takeo, Tetsumi Irie, Naomi NakagataAbstract:: Cold storage of the cauda epididymis, a male reproductive organ, is an efficient means of transporting genetically modified mice, an alternative to live animal shipment. The fertility of cold-stored sperm decreases in a time-dependent manner. However, the cause of the reduction in the fertility of sperm after cold storage remains unclear. It is known that cholesterol efflux from the sperm membrane is a trigger of capacitation. The dysfunction of cholesterol efflux due to changes in the membrane state in low temperatures may explain the reduced fertility. In this study, we examined the fertility (fertilization rate, acrosome reaction, and motility) and the amount of cholesterol and membrane fluidity in cold-stored sperm after treatment with two cholesterol acceptors, bovine serum albumin (BSA), and Methyl-Beta-Cyclodextrin (MBCD). MBCD-treated sperm exhibited the highest rate of fertilization. Two-cell embryos derived from in vitro fertilization using 0.75-mM-MBCD-treated sperm after cold storage for 72 h developed to offspring. MBCD also displayed greater ability to remove cholesterol from the sperm membrane than BSA. The percentage of viable sperm with membrane destabilization was increased by MBCD in cold-stored sperm. The acrosome reaction strongly occurred in MBCD-treated sperm. In motility analysis, MBCD improved the lateral amplitude of head movement and beat frequency. These results suggest that MBCD-induced cholesterol efflux enhances membrane fluidity and promotes acrosome reaction and hyperactivation, resulting in improved fertility of cold-stored sperm.
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reduced glutathione enhances fertility of frozen thawed c57bl 6 mouse sperm after exposure to Methyl Beta Cyclodextrin
Biology of Reproduction, 2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, 2-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse sperm.
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Reduced Glutathione Enhances Fertility of Frozen/Thawed C57BL/6 Mouse Sperm after Exposure to Methyl-Beta-Cyclodextrin
Biology of Reproduction, 2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-Beta-cycl...
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reduced glutathione enhances fertility of frozen thawed c57bl 6 mouse sperm after exposure to Methyl Beta Cyclodextrin short title glutathione facilitates fertilization in mice summary sentence adding reduced glutathione to in vitro fertilization med
2011Co-Authors: Toru Takeo, Naomi NakagataAbstract:Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, which is the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that Methyl-Beta-Cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In this study, we examined the combined effects of Methyl-Beta-Cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida by induced by reduced glutathione. Results showed that adding reduced glutathione to the fertilization medium increased the fertilization rate. We found that Methyl-Beta-Cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, two-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using Methyl-Beta-Cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse
C K Park - One of the best experts on this subject based on the ideXlab platform.
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Effect of Alpha-Linolenic Acid with Bovine Serum Albumin or Methyl-Beta-Cyclodextrin on Membrane Integrity and Oxidative Stress of Frozen-Thawed Boar Sperm.
Development & reproduction, 2019Co-Authors: Hee-tae Cheong, Boo Keun Yang, C K ParkAbstract:: The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or Methyl-Beta-Cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p
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effect of alpha linolenic acid with bovine serum albumin or Methyl Beta Cyclodextrin on membrane integrity and oxidative stress of frozen thawed boar sperm
Development & reproduction, 2019Co-Authors: Hee-tae Cheong, Boo Keun Yang, C K ParkAbstract:: The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or Methyl-Beta-Cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p<0.05). Mitochondrial activity, morphological abnormality, ROS and LPO levels in ALA+BSA or MBCD groups were no significant difference compared with ALA, BSA and MBCD treatment groups. On the other hand, plasma and acrosomal membrane intact, and sperm motility in ALA+MBCD group were higher than single treatment groups (p<0.05), whereas ALA+BSA did not differ. Our findings indicate that carrier proteins such as BSA and MBCD could improve the effect of ALA during cryopreservation of boar sperm, and treatment of ALA with carrier proteins enhance membrane integrity, mitochondrial activity through reduction of ROS-induced LPO.
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effect of Methyl Beta Cyclodextrin on the viability and acrosome damage of sex sorted sperm in frozen thawed bovine semen
Journal of Biological Research-thessaloniki, 2016Co-Authors: Boo Keun Yang, C K ParkAbstract:The regulation of Methyl-Beta-Cyclodextrin (MBCD) on cryodamage on X- and Y-sperm during cryopreservation of semen was investigated. The semen was collected from ten healthy bulls of proven fertility by an artificial vagina. The bovine sperm treated with MBCD fresh solution (0, 1, 5, 10, and 20 mM). The sperms were evaluated for viability and acrosome damage using flow cytometry. Moreover, X- and Y-sperm in frozen-thawed bovine semen were sorted by flow cytometry after Hoechst 33342-dyed, and the viability and acrosome damage of sperms were analyzed. Sperm viability in frozen-thawed semen was decreased by MBCD (p < 0.05), also the acrosome damage of sperm was significantly increased (p < 0.05). Moreover, we sorted X- and Y-sperm from frozen-thawed bovine semen for observing the viability and acrosome damage on the separated X- and Y-sperm after MBCD treatment. Viability of X-sperm was significantly lower than that of Y-sperm (p < 0.05). Also, acrosome damage of X-sperm was significantly higher than Y-sperm (p < 0.05). Methyl-Beta-Cyclodextrin enhances damage of sperm in frozen-thawed bovine semen, and X-sperm is more sensitive than Y-sperm in cell damage. These results demonstrate that MBCD can inhibit viability of spermatozoa in frozen-thawed bovine semen (for X-sperm, especially).
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Effect of Methyl-Beta-Cyclodextrin on the viability and acrosome damage of sex-sorted sperm in frozen-thawed bovine semen
Journal of Biological Research-thessaloniki, 2016Co-Authors: Boo Keun Yang, C K ParkAbstract:The regulation of Methyl-Beta-Cyclodextrin (MBCD) on cryodamage on X- and Y-sperm during cryopreservation of semen was investigated. The semen was collected from ten healthy bulls of proven fertility by an artificial vagina. The bovine sperm treated with MBCD fresh solution (0, 1, 5, 10, and 20 mM). The sperms were evaluated for viability and acrosome damage using flow cytometry. Moreover, X- and Y-sperm in frozen-thawed bovine semen were sorted by flow cytometry after Hoechst 33342-dyed, and the viability and acrosome damage of sperms were analyzed. Sperm viability in frozen-thawed semen was decreased by MBCD (p
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Effect of Methyl-Beta-Cyclodextrin on the viability and acrosome damage of sex-sorted sperm in frozen-thawed bovine semen
Journal of Biological Research-Thessaloniki, 2016Co-Authors: Boo Keun Yang, C K ParkAbstract:Background The regulation of Methyl-Beta-Cyclodextrin (MBCD) on cryodamage on X- and Y-sperm during cryopreservation of semen was investigated. The semen was collected from ten healthy bulls of proven fertility by an artificial vagina. The bovine sperm treated with MBCD fresh solution (0, 1, 5, 10, and 20 mM). The sperms were evaluated for viability and acrosome damage using flow cytometry. Moreover, X- and Y-sperm in frozen-thawed bovine semen were sorted by flow cytometry after Hoechst 33342-dyed, and the viability and acrosome damage of sperms were analyzed. Results Sperm viability in frozen-thawed semen was decreased by MBCD ( p
Sachin A. Gupte - One of the best experts on this subject based on the ideXlab platform.
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Pegylated Cholesterol and Methyl-Beta-Cyclodextrin are Modulators of L-Type Calcium Channel Current and Decrease Membrane Capacitance in Vascular Smooth Muscle Cells
Biophysical Journal, 2015Co-Authors: Rikuo Ochi, Sachin A. GupteAbstract:Loading of pegylated cholesterol (PEG-cholesterol) by pretreatment of several hours decreases current density and augments voltage-dependent inactivation of L-type Ca channel current (ICa,L) and depletion of cholesterol by similar long pretreatment with Methyl-Beta-Cyclodextrin (MbCD) increases the ICa,L density in A7r5 aortic smooth muscle cells. On the other hand, dehydroepiandrosterone (DHEA), a cholesterol-derived steroid hormone, rapidly induces voltage-dependent inhibition of ICa,L. If endocytosis and exocytosis of CaV1.2-containing membrane vesicles are involved in these modulations, they should induce a change in membrane capacitance (Cm). Cm could be affected also by a change of thickness and dielectric constant of lipid bilayer. Here we studied acute effects of PEG-cholesterol, MbCD and DHEA on Cm of isolated bovine coronary artery smooth muscle cells by whole-cell patch clamp technique. Ramp steps of 5 or 10 ms were applied repetitively before, during and after application of the modulators. Control Cm was 18.3±4.5 pF (mean±SD.). PEG-cholesterol and MbCD induced gradual and small decrease of Cm and their washout decelerated the rate of the decrease. Cm after 10 min of wash-in normalized by the initial value was: control without modulator, 1.01±0.02 (mean±SD.); 1 mM PEG-cholesterol, 0.96±0.02 (p
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pegylated cholesterol and Methyl Beta Cyclodextrin are modulators of l type calcium channel current and decrease membrane capacitance in vascular smooth muscle cells
Biophysical Journal, 2015Co-Authors: Rikuo Ochi, Sachin A. GupteAbstract:Loading of pegylated cholesterol (PEG-cholesterol) by pretreatment of several hours decreases current density and augments voltage-dependent inactivation of L-type Ca channel current (ICa,L) and depletion of cholesterol by similar long pretreatment with Methyl-Beta-Cyclodextrin (MbCD) increases the ICa,L density in A7r5 aortic smooth muscle cells. On the other hand, dehydroepiandrosterone (DHEA), a cholesterol-derived steroid hormone, rapidly induces voltage-dependent inhibition of ICa,L. If endocytosis and exocytosis of CaV1.2-containing membrane vesicles are involved in these modulations, they should induce a change in membrane capacitance (Cm). Cm could be affected also by a change of thickness and dielectric constant of lipid bilayer. Here we studied acute effects of PEG-cholesterol, MbCD and DHEA on Cm of isolated bovine coronary artery smooth muscle cells by whole-cell patch clamp technique. Ramp steps of 5 or 10 ms were applied repetitively before, during and after application of the modulators. Control Cm was 18.3±4.5 pF (mean±SD.). PEG-cholesterol and MbCD induced gradual and small decrease of Cm and their washout decelerated the rate of the decrease. Cm after 10 min of wash-in normalized by the initial value was: control without modulator, 1.01±0.02 (mean±SD.); 1 mM PEG-cholesterol, 0.96±0.02 (p<0.01, compared with control); 10 mM MbCD, 0.90±0.05 (p<0.0001); 0.1 mM DHEA, 1.00±0.03. Since the change of Cm is small, it little affects qualitative conclusion of the modulation of ICa,L density obtained by the pretreatment experiments with PEG-cholesterol and MbCD. The small but significant decrease of Cm reflects structural changes of the lipid bilayer which may be involved in the modulation of ICa,L by PEG-cholesterol and MbCD.
Tetsumi Irie - One of the best experts on this subject based on the ideXlab platform.
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fertility of cold stored mouse sperm is recovered by promoting acrosome reaction and hyperactivation after cholesterol efflux by Methyl Beta Cyclodextrin
Biology of Reproduction, 2017Co-Authors: Hidetaka Yoshimoto, Toru Takeo, Tetsumi Irie, Naomi NakagataAbstract:: Cold storage of the cauda epididymis, a male reproductive organ, is an efficient means of transporting genetically modified mice, an alternative to live animal shipment. The fertility of cold-stored sperm decreases in a time-dependent manner. However, the cause of the reduction in the fertility of sperm after cold storage remains unclear. It is known that cholesterol efflux from the sperm membrane is a trigger of capacitation. The dysfunction of cholesterol efflux due to changes in the membrane state in low temperatures may explain the reduced fertility. In this study, we examined the fertility (fertilization rate, acrosome reaction, and motility) and the amount of cholesterol and membrane fluidity in cold-stored sperm after treatment with two cholesterol acceptors, bovine serum albumin (BSA), and Methyl-Beta-Cyclodextrin (MBCD). MBCD-treated sperm exhibited the highest rate of fertilization. Two-cell embryos derived from in vitro fertilization using 0.75-mM-MBCD-treated sperm after cold storage for 72 h developed to offspring. MBCD also displayed greater ability to remove cholesterol from the sperm membrane than BSA. The percentage of viable sperm with membrane destabilization was increased by MBCD in cold-stored sperm. The acrosome reaction strongly occurred in MBCD-treated sperm. In motility analysis, MBCD improved the lateral amplitude of head movement and beat frequency. These results suggest that MBCD-induced cholesterol efflux enhances membrane fluidity and promotes acrosome reaction and hyperactivation, resulting in improved fertility of cold-stored sperm.
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Methyl Beta Cyclodextrin improves fertilizing ability of c57bl 6 mouse sperm after freezing and thawing by facilitating cholesterol efflux from the cells
Biology of Reproduction, 2008Co-Authors: Toru Takeo, Hidetoshi Arima, Takayuki Hoshii, Yuki Kondo, Hiroshi Toyodome, Ken Ichi Yamamura, Tetsumi Irie, Naomi NakagataAbstract:Abstract Sperm cryopreservation provides an economical means of storing genetically engineered mouse strains in resource facilities. In general, relatively high fertilization rates are obtained for frozen/thawed sperm of the CBA/JN, DBA/2N, and C3H inbred strains and some F1 hybrid strains. However, the fertilization rate for frozen/thawed sperm of C57BL/6, which is the main strain of genetically engineered mice, remains very low. Therefore, it is necessary to establish an in vitro fertilization (IVF) method for cryopreserved C57BL/6 sperm that can obtain a high rate of fertilization after thawing. In the present study, we focused on the effects of Methyl-Beta-Cyclodextrin (MBCD) on the fertilizing ability of frozen/thawed C57BL/6 sperm. Our results have shown that the highest fertilization rate for frozen/thawed sperm was obtained with MBCD at 1.0 mM for 30 min (63.7% ± 11.0%), but the effects were attenuated by long-term incubation for 120 min at 1.0 or 2.0 mM. The embryos with frozen/thawed sperm showe...
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Methyl-Beta-Cyclodextrin Improves Fertilizing Ability of C57BL/6 Mouse Sperm after Freezing and Thawing by Facilitating Cholesterol Efflux from the Cells
Biology of Reproduction, 2007Co-Authors: Toru Takeo, Hidetoshi Arima, Takayuki Hoshii, Yuki Kondo, Hiroshi Toyodome, Ken Ichi Yamamura, Tetsumi Irie, Naomi NakagataAbstract:Abstract Sperm cryopreservation provides an economical means of storing genetically engineered mouse strains in resource facilities. In general, relatively high fertilization rates are obtained for frozen/thawed sperm of the CBA/JN, DBA/2N, and C3H inbred strains and some F1 hybrid strains. However, the fertilization rate for frozen/thawed sperm of C57BL/6, which is the main strain of genetically engineered mice, remains very low. Therefore, it is necessary to establish an in vitro fertilization (IVF) method for cryopreserved C57BL/6 sperm that can obtain a high rate of fertilization after thawing. In the present study, we focused on the effects of Methyl-Beta-Cyclodextrin (MBCD) on the fertilizing ability of frozen/thawed C57BL/6 sperm. Our results have shown that the highest fertilization rate for frozen/thawed sperm was obtained with MBCD at 1.0 mM for 30 min (63.7% ± 11.0%), but the effects were attenuated by long-term incubation for 120 min at 1.0 or 2.0 mM. The embryos with frozen/thawed sperm showe...