Dysregulation of intracellular pH is a cause of impaired capacitation in Slc22a14-deficient mice

Reproduction ◽  
2021 ◽  
Author(s):  
Momoe Ito ◽  
Masato Unou ◽  
Toshiya Higuchi ◽  
Shuhei So ◽  
Masahiko Ito ◽  
...  

Solute carrier 22a member 14 (SLC22A14) plays a critical role in male infertility in mice. We previously revealed that one of the causes of infertility is impaired capacitation. However, the molecular mechanism remained unclear. Here, we show that the influx of HCO3–, a trigger of capacitation, is impaired and intracellular pH is decreased in the sperm of Slc22a14 knockout (KO) mice. While intracellular cAMP concentration did not increase during capacitation in Slc22a14 KO spermatozoa, HCO3–-dependent soluble adenylate cyclase activity was normal, and the addition of 8-bromo cAMP rescued the decreased protein tyrosine phosphorylation. In addition, the intracellular pH of Slc22a14 KO sperm was lower than that of wild-type sperm and did not increase after the addition of HCO3–. Although its relationship to the regulation of intracellular pH is unknown, TMEM225, a possible protein phosphatase inhibitor, was found to be decreased in Slc22a14 KO sperm. The decreased in vitro fertilization rate of Slc22a14 KO sperm was partially rescued by an increase in the intracellular pH (pHi) and the addition of 8-bromo cAMP. These results suggest that SLC22A14 is involved in capacitation through the regulation of HCO3– transport and pHi.

1975 ◽  
Vol 66 (2) ◽  
pp. 392-403 ◽  
Author(s):  
B Storrie

Exposure of CHO-K1 cells in vitro to dibutyryl adenosine cyclic 3',5'-monophosphate (DBcAMP) plus testololactone produces a rapid, reversible antagonism of ligand-induced collection of initially dispersed concanavalin A (Con A) binding sites into a caplike mass. Morphologically, as Con A capping occurs, the cells become less spread and then round completely. With prolonged Con A exposure, cells cultured in either the absence or the presence of DBcAMP plus testololactone cap and round. Capping is blocked by cold treatment and respiratory inhibitors. Colcemid at concentrations greater than 1 muM promotes both Con A capping and cell rounding. Cytochalasin B at similar concentrations inhibits both capping and cell rounding. Treatment of cells with Con A has little effect on intracellular cAMP concentration. Possible mechanisms by which cAMP may modulate the movement of Con A binding sites are discussed.


2019 ◽  
Vol 112 (3) ◽  
pp. e201-e202 ◽  
Author(s):  
Stephanie Gunderson ◽  
Lis C. Puga Molina ◽  
Joan Riley ◽  
Emily S. Jungheim ◽  
Celia M. Santi

Author(s):  
Valeria Merico ◽  
Silvia Garagna ◽  
Maurizio Zuccotti

The presence of cumulus cells (CCs) surrounding ovulated eggs is beneficial to in vitro fertilization and preimplantation development outcomes in several mammalian species. In the mouse, this contribution has a negligible effect on the fertilization rate; however, it is not yet clear whether it has positive effects on preimplantation development. Here, we compared the rates of in vitro fertilization and preimplantation development of ovulated B6C3F1 CC-enclosed vs. CC-free eggs, the latter obtained either after a 5 min treatment in M2 medium containing hyaluronidase or after 5–25 min in M2 medium supplemented with 34.2 mM EDTA (M2-EDTA). We found that, although the maintenance of CCs around ovulated eggs does not increment their developmental rate to blastocyst, the quality of the latter is significantly enhanced. Most importantly, for the first time, we describe a further quantitative and qualitative improvement, on preimplantation development, when CC-enclosed eggs are isolated from the oviducts in M2-EDTA and left in this medium for a total of 5 min prior to sperm insemination. Altogether, our results establish an important advancement in mouse IVF procedures that would be now interesting to test on other mammalian species.


2021 ◽  
Author(s):  
Weihai Xu ◽  
Lin Zhang ◽  
Ling Zhang ◽  
Shishi Li ◽  
Jing Shu

Abstract Background: In this study, we compared the in vitro embryo development, embryo transfer outcome and the offspring outcome in the in vitro fertilization-embryo transfer (IVF-ET) between dry culture (DC) and humid culture (HC). Methods: Our study was divided into two parts. Firstly, we determined the fertilization rate, cleavage rate and high-quality embryo rate from 21 cycles in the DC group (N=262 oocytes) and HC group (N=263 oocytes). Secondly, we determined the embryo transfer outcome and the offspring outcome in DC group (N=184 cycles) and HC group (N=136 cycles). Results: Compared with the HC group, significant increase was observed in the high-quality embryo rate (66.1.2% vs. 55.3%, p=0.037) and implantation rate (49.8% vs. 40.6%, p=0.027) in the DC group. No statistical differences were observed in the pregnant outcome and birth defect of the offspring (p>0.05). Compared with HC, DC was associated with a higher high-quality embryo rate and a higher implantation rate after embryo transfer. Conclusions: No statistical differences were noticed in the offspring conditions between the two culture modes. Taken together, DC may serve as a promising method for IVF-ET.


2018 ◽  
Vol 9 (4) ◽  
pp. 112
Author(s):  
Heba F Salem ◽  
Mai Raslan ◽  
Hanaa Suliman ◽  
Tamer Essam ◽  
Saber Abd-Allah

<p>This study was conducted to produce nanosized cyclodextrin (NCD) and assess its effect on bovine spermatozoa during In vitro fertilization (IVF) to optimize the capacitation media for successful IVF. Therefore, Four cyclodextrin formulations were prepared and characterized. Data analysis revealed the best formula (F2) showed a smallest particle size (15 nm), zeta potential (-37 mv), and higher yield percentages (95%) was selected for spem capacitation. Motile spermatozoa were separated from frozen-thawed semen by a swim-up procedure and capacitated in IVF-TALP medium with different formulae of NCD or CD or without treatments (control) and incubated for 3hours(hr) at 38°C and evaluated every one (hr) interval. Data analysis revealed that the formulation of cyclodextrin nanoparticles (F2<strong>)</strong> after (2hr) incubation in the media gave best effect on sperm capacitation and acrosme reaction (AR) and effect of sperm treated with NCD on fertilization rate was evaluated. The results showed that the proportion of Oocytes fertilized was increased significantly in F2 (60%) than in the control (35%), and cyclodextrin group (50%) groups (<em>p</em>&lt;0.05). It could be inferred from this investigation that cyclodextrin nanoparticles can be used for biomedical interventions in bovine spermatozoa. NCD improve sperm motility, viability, and (AR), also fertilization rate of sperm treated with NCD increase. So NCD gave positive effect on sperm functions during IVF. </p>


2018 ◽  
Vol 28 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Sneha Mani ◽  
Jayashri Ghosh ◽  
Yemin Lan ◽  
Suneeta Senapati ◽  
Teri Ord ◽  
...  

Abstract Preterm birth (PTB) affects approximately 1 in 10 pregnancies and contributes to approximately 50% of neonatal mortality. However, despite decades of research, little is understood about the etiology of PTB, likely due to the multifactorial nature of the disease. In this study, we examined preterm and term placentas, from unassisted conceptions and those conceived using in vitro fertilization (IVF). IVF increases the risk of PTB and causes epigenetic change in the placenta and fetus; therefore, we utilized these patients as a unique population with a potential common etiology. We investigated genome-wide DNA methylation in placentas from term IVF, preterm IVF, term control (unassisted conception) and preterm control pregnancies and discovered epigenetic dysregulation of multiple genes involved in cell migration, including members of the ADAMTS family, ADAMTS12 and ADAMTS16. These genes function in extracellular matrix regulation and tumor cell invasion, processes replicated by invasive trophoblasts (extravillous trophoblasts (EVTs)) during early placentation. Though expression was similar between term and preterm placentas, we found that both genes demonstrate high expression in first- and second-trimester placenta, specifically in EVTs and syncytiotrophoblasts. When we knocked down ADAMTS12 or ADAMTS16in vitro, there was poor EVT invasion and reduced matrix metalloproteinase activity, reinforcing their critical role in placentation. In conclusion, utilizing a population at high risk for PTB, we have identified a role for ADAMTS gene methylation in regulating early placentation and susceptibility to PTB.


2021 ◽  
Author(s):  
Qiuhua Yang ◽  
Jiean Xu ◽  
Qian Ma ◽  
Zhiping Liu ◽  
Yaqi Zhou ◽  
...  

Overnutrition-induced endothelial inflammation plays a crucial role in high fat diet (HFD)-induced insulin resistance in animals. Endothelial glycolysis plays a critical role in endothelial inflammation and proliferation, but its role in diet-induced endothelial inflammation and subsequent insulin resistance has not been elucidated. PFKFB3 is a critical glycolytic regulator, and its increased expression has been observed in adipose vascular endothelium of C57BL/6J mice fed with HFD in vivo, and in palmitate (PA)-treated primary human adipose microvascular endothelial cells (HAMECs) in vitro. We generated mice with Pfkfb3 deficiency selective for endothelial cells to examine the effect of endothelial Pfkfb3 in endothelial inflammation in metabolic organs and in the development of HFD-induced insulin resistance. EC Pfkfb3-deficient mice exhibited mitigated HFD-induced insulin resistance, including decreased body weight and fat mass, improved glucose clearance and insulin sensitivity, and alleviated adiposity and hepatic steatosis. Mechanistically, cultured PFKFB3 knockdown HAMECs showed decreased NF-κB activation induced by PA, and consequent suppressed adhesion molecule expression and monocyte adhesion. Taken together, these results demonstrate that increased endothelial PFKFB3 expression promotes diet-induced inflammatory responses and subsequent insulin resistance, suggesting that endothelial metabolic alteration plays an important role in the development of insulin resistance.


2020 ◽  
Author(s):  
Ji Liu ◽  
Yan-Hua Zhou ◽  
Xiao-Xiao Wang ◽  
Ling-Xi Tong ◽  
Yan-Hong Li ◽  
...  

Abstract Background: Different types of incubators have been designed for gamete and embryo culture in the past few years. The main differences of these incubators are humidity, temperature and gas control system, which play important roles in regulating the steady state of culture media. The objective of this study was to compare the effects of different types of incubators (air jacket incubators and water jacket incubators) on embryo development and clinical outcomes in human in vitro fertilization (IVF).Methods: First, the physical performances of different incubators were tested by mimicking routine IVF procedures. After that, in a randomized controlled trial, 1013 cumulus oocyte complexes from 43 patients were equally divided into two groups, fertilized and cultured in two types of incubators to analyze the effects of different types of incubators on embryo development and clinical outcomes. Results: We found that temperature recovery time in the air jacket incubator was significantly shorter than that in water jacket incubator. Although the O2 recovering time was also significantly shorter in the air jacket incubator as compared with the water jacket incubator, no significant differences were observed in the CO2 recovering time between two groups, which was also verified by pH recovering time of culture media. Besides, the temperature of culture medium in the dish covered with oil recovered more quickly in the air jacket incubators than that in water jacket incubators. However, there were no significant differences observed in the fertilization rate, Day 3 high-quality embryo formation rate, blastocyst formation rate, good blastocyst rate and clinical outcomes between two groups.Conclusions: These results indicate that the microenvironment, especially the temperature, in air jacket incubator recover faster than that in conventional water jacket incubator, however, there were no significant differences in embryo development and clinical outcomes between two types of incubators.


Author(s):  
Ales Sobek ◽  
Emil Tkadlec ◽  
Eva Klaskova ◽  
Martin Prochazka

Abstract The aim of this study was to evaluate if cytoplasmic transfer can improve fertilization and embryo quality of women with oocytes of low quality. During ICSI, 10–15% of the cytoplasm from a fresh or frozen young donor oocyte was added to the recipient oocyte. According to the embryo quality, we defined group A as patients in which the best embryo was evident after cytoplasmic transfer and group B as patients in which the best embryo was evident after a simple ICSI. We investigated in the period of 2002–2018, 125 in vitro fertilization cycles involving 1011 fertilized oocytes. Five hundred fifty-seven sibling oocytes were fertilized using ICSI only and 454 oocytes with cytoplasmic transfer. Fertilization rates of oocytes were 67.2% in the cytoplasmic transfer and 53.5% in the ICSI groups (P < 0.001). A reduction in fertilization rate was observed with increased women age in the ICSI but not in the cytoplasmic transfer groups. The best embryo quality was found after cytoplasmic transfer in 78 cycles (62.4%) and without cytoplasmic transfer in 40 cycles (32%, P < 0.001). No significant differences were detected between the age, hormonal levels, dose of stimulation drugs, number of transferred embryos, pregnancy rate and abortion rate between A and B groups. Cytoplasmic transfer improves fertilization rates and early embryo development in humans with low oocyte quality. All 28 children resulting from cytoplasmic transfer are healthy.


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