scholarly journals Interleukin-6 requires JAK to stimulate inner cell mass expansion in bovine embryos

Reproduction ◽  
2019 ◽  
Vol 158 (4) ◽  
pp. 303-312 ◽  
Author(s):  
Lydia K Wooldridge ◽  
Sally E Johnson ◽  
Rebecca R Cockrum ◽  
Alan D Ealy
Keyword(s):  
Interleukin 6 ◽  
Nuclear Translocation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Janus Kinase ◽  
Bovine Embryos ◽  
Cell Numbers ◽  
Stat3 Phosphorylation

Supplementing interleukin-6 (IL6) to in vitro-produced bovine embryos increases inner cell mass (ICM) cell numbers in blastocysts. A series of studies were completed to further dissect this effect. Treatment with IL6 increased ICM cell numbers in early, regular and expanded blastocysts but had no effect on morulae total cell number. Treatment with IL6 for 30 min induced signal transducer and activator of transcription 3 (STAT3) phosphorylation and nuclear translocation in all blastomeres in early morulae and specifically within the ICM in blastocysts. Also, IL6 supplementation increased SOCS3 mRNA abundance, a STAT3-responsive gene, in blastocysts. Chemical inhibition of Janus kinase (JAK) activity from day 5 to day 8 prevented STAT3 activation and the IL6-induced ICM cell number increase. Global transcriptome analysis of blastocysts found that transcripts for IL6 and its receptor subunits (IL6R and IL6ST) were the most abundantly expressed IL6 family ligand and receptors. These results indicate that IL6 increases ICM cell numbers as the ICM lineage emerges at the early blastocyst stage through a STAT3-dependent mechanism. Also, IL6 appears to be the primary IL6 cytokine family member utilized by bovine blastocysts to control ICM cell numbers.

scholarly journals Interleukin-6 promotes primitive endoderm development in bovine blastocysts

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy
Keyword(s):  
Interleukin 6 ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Janus Kinase ◽  
Primitive Endoderm ◽  
Cell Numbers ◽  
Downstream Target ◽  
Dependent Signal ◽  
Endoderm Development

Abstract Background Interleukin-6 (IL6) was recently identified as an embryotrophic factor in bovine embryos, where it acts primarily to mediate inner cell mass (ICM) size. This work explored whether IL6 affects epiblast (EPI) and primitive endoderm (PE) development, the two embryonic lineages generated from the ICM after its formation. Nuclear markers for EPI (NANOG) and PE (GATA6) were used to differentiate the two cell types. Results Increases (P < 0.05) in total ICM cell numbers and PE cell numbers were detected in bovine blastocysts at day 8 and 9 post-fertilization after exposure to 100 ng/ml recombinant bovine IL6. Also, IL6 increased (P < 0.05) the number of undifferentiated ICM cells (cells containing both PE and EPI markers). The effects of IL6 on EPI cell numbers were inconsistent. Studies were also completed to explore the importance of Janus kinase 2 (JAK2)-dependent signaling in bovine PE cells. Definitive activation of STAT3, a downstream target for JAK2, was observed in PE cells. Also, pharmacological inhibition of JAK2 decreased (P < 0.05) PE cell numbers. Conclusions To conclude, IL6 manipulates ICM development after EPI/PE cell fates are established. The PE cells are the target for IL6, where a JAK-dependent signal is used to regulate PE numbers.

Use of chemically defined system for the direct comparison of inner cell mass and trophectoderm distribution in murine, porcine and bovine embryos

Zygote ◽  
1997 ◽  
Vol 5 (4) ◽  
pp. 309-320 ◽  
Author(s):  
Rabindranath de la Fuente ◽  
W. Allan King
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Total Cell ◽  
Differential Staining ◽  
Similar Proportion ◽  
Bovine Embryos ◽  
Total Cell Number ◽  
Cell Numbers

SummaryThe mammalian blastocyst comprises an inner cell mass (ICM) and a trophectoderm cell layer. In this study the allocation of blastomeres to either cell lineage was compared between murine, porcine and bovine blastocysts. Chemical permeation of trophectoderm cells by the Ca2+ ionophore A23187 in combination with DNA-specific fluorochromes resulted in the differential staining of trophectoderm and ICM. Confocal microscopy confirmed the exclusive permeation of trophectoderm and the internal localisation of intact ICM cells in bovine blastocysts. Overall, differential cell counts were obtained in approximately 85% of the embryos assessed. Mean (±SEM) total cell numbers were 72.2 ± 3.1 and 93.1±5 for in vivo derived murine (n = 41) and porcine (n = 21) expanded blastocysts, respectively. Corresponding ICM cell number counts revealed ICM/total cell number ratios of 0.27 and 0.21, respectively. Comparison of in vivo (n = 20) and in vitro derived bovine embryos on day 8 (n = 29) or day 9 (n = 29) revealed a total cell number of 195.25±9.9, 166.14±9.9 and 105±6.7 at the expanded blastocyst stage with corresponding ICM/total cell ratios of 0.27, 0.23 and 0.23, respectively. While total cell numbers differed significantly among the three groups of bovine embryos (p<0.05), the ICM/total cell ratio did not. These results indicate that a similar proportion of cells is allocated to the ICM among blastocysts of genetically divergent species.

The human blastocyst: cell number, death and allocation during late preimplantation development in vitro

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 597-604 ◽  
Author(s):  
K. Hardy ◽  
A.H. Handyside ◽  
R.M. Winston
Keyword(s):  
Cell Death ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Human Embryos ◽  
Cell Numbers ◽  
Human Blastocyst ◽  
Development In Vitro

The development of 181 surplus human embryos, including both normally and abnormally fertilized, was observed from day 2 to day 5, 6 or 7 in vitro. 63/149 (42%) normally fertilized embryos reached the blastocyst stage on day 5 or 6. Total, trophectoderm (TE) and inner cell mass (ICM) cell numbers were analyzed by differential labelling of the nuclei with polynucleotide-specific fluorochromes. The TE nuclei were labelled with one fluorochrome during immunosurgical lysis, before fixing the embryo and labelling both sets of nuclei with a second fluorochrome (Handyside and Hunter, 1984, 1986). Newly expanded normally fertilized blastocysts on day 5 had a total of 58.3 +/− 8.1 cells, which increased to 84.4 +/− 5.7 and 125.5 +/− 19 on days 6 and 7, respectively. The numbers of TE cells were similar on days 5 and 6 (37.9 +/− 6.0 and 40.3 +/− 5.0, respectively) and then doubled on day 7 (80.6 +/− 15.2). In contrast, ICM cell numbers doubled between days 5 and 6 (20.4 +/− 4.0 and 41.9 +/− 5.0, respectively) and remained virtually unchanged on day 7 (45.6 +/− 10.2). There was widespread cell death in both the TE and ICM as evidenced by fragmenting nuclei, which increased substantially by day 7. These results are compared with the numbers of cells in morphologically abnormal blastocysts and blastocysts derived from abnormally fertilized embryos. The nuclei of arrested embryos were also examined. The number of TE and ICM cells allocated in normally fertilized blastocysts appears to be similar to the numbers allocated in the mouse. Unlike the mouse, however, the proportion of ICM cells remains higher, despite cell death in both lineages.

15 HISTONE ACETYLATION PROFILE OF PORCINE EMBRYOS PRODUCED BY 2 CLONING METHODS WITH OR WITHOUT IN VITRO CULTURE

2016 ◽  
Vol 28 (2) ◽  
pp. 137
Author(s):  
Y. Liu ◽  
A. Lucas-Hahn ◽  
B. Petersen ◽  
R. Li ◽  
D. Hermann ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Vitro Culture ◽  
Histone Acetylation ◽  
Mrna Expression ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Cell Numbers ◽  
Cloning Method

Conventional “Dolly”-based cloned (CNT) embryos maintain zona pellucida and can be transferred early in development. Handmade cloned (HMC) embryos are zona free and are cultured to later stages for transfer. We have shown differences between HMC and CNT embryos (Rep. Fert. Dev. 26, 123), and both in vitro culture and cloning method (NT) are associated with alterations in histone acetylation. More studies are needed to clarify whether CNT and HMC embryos differ in epigenetic profiles due to NT method or culture condition. Here we investigated histone acetylation profile of NT embryos produced by CNT or HMC with or without 5 to 6 days in vitro culture, emphasising quality and gene expression in resulting embryos. Both NT methods were performed on Day 0 (D0) with same oocyte batch, donor cells, and culture medium (CNT in group, HMC in well of well). On D0, 5, and 6 after CNT (Clon. Stem Cells 10, 355) or HMC (Zygote 20, 61), all developed embryos of all morphological qualities were collected for immunostaining of H3K18ac, and on D0 and 6 for mRNA expression of the genes KAT2A/2B, EP300, HDAC1/2, DNMT1o/s, and GAPDH. Embryo quality was evaluated normal (clear inner cell mass, high cell number, no fragments) or bad (no clear inner cell mass, low cell number, fragments). Cell numbers per blastocyst were counted on D5 and 6. Differences in cell number and H3K18ac level between different groups and days were analysed by ANOVA; gene expression data were analysed by GLM (SAS version 9.3, SAS Institute Inc., Cary, NC, USA). Embryo development rates of both NT methods were reported previously (Rep. Fert. Dev. 26, 123). On D5 and 6, all HMC embryos were evaluated as normal, but the CNT group contained both normal and bad embryos. Regarding cell numbers (Table 1), on D5 there was no difference between normal CNT and HMC embryos, but numbers were lower in CNT bad embryos. On D6 the blastocyst cell number was lower in both normal and bad CNT embryos compared with HMC. Regarding H3K18ac levels (Table 1), no differences were found on D5 between normal CNT and HMC embryos, but on D6 both CNT normal and bad embryos had higher H3K18ac level compared with HMC. On D0, no difference was found in mRNA expression of all 8 genes. On D6, KAT2A expression was slight increased (1.8-fold) in CNT compared with HMC embryos (P < 0.05). In conclusion, no differences were found between CNT and HMC embryos after completed NT procedure (D0) or after 5 days in vitro culture. However, differences in quality (cell number and H3K18ac) and gene expression between the 2 NT methods were observed when blastocyst expansion was initiated (D6). Thus, the 2 NT methods seem to produce embryos of similar quality, which is maintained over 5 days in vitro culture, but thereafter gene expression and histone acetylation are more active in CNT embryos. Table 1.Cell number and H3K18ac level1

scholarly journals Leukemia Inhibitory Factor Stimulates Primitive Endoderm Expansion in the Bovine Inner Cell Mass

2021 ◽  
Vol 2 ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy
Keyword(s):  
Leukemia Inhibitory Factor ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Inhibitory Factor ◽  
Primitive Endoderm ◽  
Total Cell Number ◽  
Cell Numbers ◽  
Bovine Blastocyst

Previous work determined that bovine interleukin-6 (IL6) increases inner cell mass (ICM), primitive endoderm (PE), and total cell number in in vitro produced (IVP) bovine blastocysts. Another IL6 family member, leukemia inhibitory factor (LIF), has the potential to produce the same effects of IL6 due to the presence of its receptor in bovine blastocysts. We compared the abilities of LIF and IL6 to increase ICM cell numbers in day 7, 8, and 9 IVP bovine blastocysts. Supplementation with 100 ng/ml LIF from day 5 onward improved blastocyst formation rates on days 7 and 8 similar to what was observed when supplementing 100 ng/ml IL6. However, LIF supplementation did not cause an increase in ICM numbers like was observed after supplementing IL6. On day 9, increases in PE cell numbers were detected after LIF supplementation, but 300 ng/ml LIF was required to achieve the same effect on PE numbers that was observed by providing 100 ng/ml IL6. Collectively, these results show that LIF can mimic at least some of the effects of IL6 in bovine blastocyst.

scholarly journals 127APOPTOSIS IN BOVINE BLASTOCYSTS FROM FIVE DIFFERENT PRODUCTION SYSTEMS

2004 ◽  
Vol 16 (2) ◽  
pp. 186
Author(s):  
J.O. Gjørret ◽  
P. Maddox-Hyttel
Keyword(s):  
Production Systems ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Embryo Cell ◽  
Developmental Potential ◽  
Cell Numbers ◽  
Tunel Reaction

Regulation of apoptosis may be affected by factors during preimplantation development, and this is possibly related to embryo developmental potential. Here we investigate differences in the incidence of apoptotic nuclei in Day 7 bovine blastocysts produced by two different in vivo and three different in vitro methods. In vivo embryos were produced either by a regular superovulation procedure (reg group; n=29; Laurincik et al., 2003, Mol. Reprod. Dev. 65, 73–85), or by postponement of the LH surge (pp group; n=35; van de Leemput et al., 2001, Therio. 55, 573–592). In vitro embryos were derived from systems using either co-culture (cc group; n=30, Avery and Greve 2000, Mol. Reprod. Dev. 55, 438–445), or culture in synthetic oviduct fluid (SOF) with (S+group; n=35) or without serum (S− group; n=38; Holm et al., 1999, Theriogenology, 52, 683–700). Embryos were collected at approx. 168h post ovulation/insemination and subjected to chromatin staining and detection of DNA degradation by TUNEL reaction. The total number of nuclei, number of nuclei displaying apoptotic morphology (+M), number of nuclei displaying TUNEL reaction (+T), and number of nuclei displaying both markers simultaneously (M&amp;T) were scored according to J.O. Gjørret et al. (2003 Biol. Reprod. 69. in press). Only M&amp;T nuclei were regarded as apoptotic, and +M, +T, and apoptotic (M&amp;T) indices (%) were calculated for the trophoblast (tb), inner cell mass (i) and the total blastocysts (t) in each group. Significant differences were observed for all parameters when all groups were compared (ANOVA, P ranging from 0.024 to&lt;0.0001). Highest number of total nuclei were observed in the S+ group, whereas the lowest indices were observed in the pp group, which had significant lower indices in the i and t than in the reg., S+ and S− groups P&lt;0.05; Tukey’s post test for ANOVA). Highest indices were generally observed in the S− group. The results demonstrate that not only embryo cell numbers but also incidences of apoptotic markers are affected by the mode of production. However, in Day 7 bovine blastocysts high cell number is not consistent with a low incidence of apoptosis. Even though cell numbers appeared comparable in the two in vivo groups, their incidences of apoptosis were different, and the reg group displayed indices comparable to the in vitro groups, highlighting the importance of ovulation protocols when in vivo embryos are used as reference material in general. Table 1

scholarly journals Effect of cysteamine supplementation during in vitro culture of early stage bovine embryos on blastocyst rate and quality

2012 ◽  
Vol 81 (3) ◽  
pp. 229-234 ◽  
Author(s):  
Martina Lojkic ◽  
Iva Getz ◽  
Marko Samardžija ◽  
Mario Matkovic ◽  
Goran Bacic ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Culture Media ◽  
Cell Mass ◽  
Cell Number ◽  
Total Cell ◽  
Hatching Rate ◽  
Bovine Embryos ◽  
Total Cell Number ◽  
Oviductal Fluid

The aim of this study was to evaluate whether the addition of cysteamine to the in vitro culture media enhances the yield, hatching rate, total cell number and inner cell mass/total cell number ratio of bovine embryos. A total of 933 bovine oocytes collected from ovaries of 60 slaughtered donors were subjected to in vitro maturation and in vitro fertilization. Following fertilization, embryos were cultured in synthetic oviductal fluid without glucose. After 24 h embryos were transferred into synthetic oviductal fluid with 1.5 mM glucose and 0 (control), 50, 100 and 200 µM of cysteamine. After 48 h, the embryos were transferred into synthetic oviductal fluid with glucose but without cysteamine and cultured until Day 9. The number of cleaved embryos on Day 2, the total number of blastocysts on Day 7 and the number of hatched blastocysts on Day 9 were calculated. Differential staining of inner cell mass and trophectoderm cells of blastocysts were performed on Day 7 and Day 9 of in vitro culture. Supplementation of in vitro culture media with 100 µM cysteamine increased the blastocyst yield (P < 0.05) without affecting the hatching rate. Furthermore, the embryos cultured in the presence of 100 µM cysteamine had significantly higher number of inner cell mass cells (P < 0.05) and the proportion of inner cell mass cells (P < 0.05) compared with the controls. The results of the present study demonstrated that the addition of 100 µM cysteamine to the in vitro culture media improved blastocyst production rate and enhance embryo quality, which could lead to the improvement of the in vitro culture system for bovine embryos.

Development of bovine embryos cultured in CR1aa and IVD101 media using different oxygen tensions and culture systems

2010 ◽  
Vol 58 (4) ◽  
pp. 465-474 ◽  
Author(s):  
Tamás Somfai ◽  
Yasushi Inaba ◽  
Yoshio Aikawa ◽  
Masaki Ohtake ◽  
Shuji Kobayashi ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Culture Media ◽  
Cell Mass ◽  
Calf Serum ◽  
Bovine Embryos ◽  
Blastocyst Formation ◽  
Cell Numbers ◽  
Culture Systems ◽  
Significant Difference

The aim of the present study was to optimise the culture conditions for the in vitro production of bovine embryos. The development of in vitro fertilised bovine oocytes in CR1aa supplemented with 5% calf serum and IVD101 culture media were compared using traditional microdrops and Well of the Well (WOW) culture systems either under 5% or 20% oxygen tension. After 7 days of culture, a significantly higher blastocyst formation rate was obtained for embryos cultured in CR1aa medium compared to those cultured in IVD101, irrespective of O 2 tensions and culture systems. The blastocyst formation in IVD101 was suppressed under 20% O 2 compared to 5% O 2 . Despite their similar total cell numbers, higher rates of inner cell mass (ICM) cells were observed in blastocysts developed in IVD101 medium than in those developed in CR1aa, irrespective of O 2 tensions. There was no significant difference in blastocyst formation, total, ICM and trophectoderm (TE) cell numbers between embryos obtained by microdrop and WOW culture systems irrespective of the culture media and O 2 tensions used. In conclusion, CR1aa resulted in higher blastocyst formation rates irrespective of O 2 tension, whereas IVD101 supported blastocyst formation only under low O 2 levels but enhanced the proliferation of ICM cells.

scholarly journals Interleukin-6 Promotes Primitive Endoderm Development in Bovine Blastocysts

2020 ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy
Keyword(s):  
Interleukin 6 ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Janus Kinase ◽  
Primitive Endoderm ◽  
Cell Numbers ◽  
Downstream Target ◽  
Dependent Signal ◽  
Endoderm Development

Abstract Background: Interleukin-6 (IL6) was recently identified as an embryotrophic factor in bovine embryos, where it acts primarily to mediate inner cell mass (ICM) size. This work explored whether IL6 affects epiblast (EPI) and primitive endoderm (PE) development, the two embryonic lineages generated from the ICM after its formation. Nuclear markers for EPI (NANOG) and PE (GATA6) were used to differentiate the two cell types. Results: Increases (P<0.05) in total ICM cell numbers and PE cell numbers were detected in bovine blastocysts at day 8 and 9 post-fertilization after exposure to 100 ng/ml recombinant bovine IL6. Also, IL6 increased (P<0.05) the number of undifferentiated ICM cells (cells containing both PE and EPI markers). The effects of IL6 on EPI cell numbers were inconsistent. Studies were also completed to explore the importance of Janus kinase 2 (JAK2)-dependent signaling in bovine PE cells. Definitive activation of STAT3, a downstream target for JAK2, was observed in PE cells. Also, pharmacological inhibition of JAK2 decreased (P<0.05) PE cell numbers. Conclusions: To conclude, IL6 manipulates ICM development after EPI/PE cell fates are established. The PE cells are the target for IL6, where a JAK-dependent signal is used to regulate PE numbers.

scholarly journals Leukemia inhibitory factor stimulates primitive endoderm expansion in the bovine inner cell mass

2021 ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy
Keyword(s):  
Leukemia Inhibitory Factor ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Inhibitory Factor ◽  
Primitive Endoderm ◽  
Total Cell Number ◽  
Cell Numbers ◽  
Bovine Blastocyst

Abstract Previous work determined that bovine interleukin-6 (IL6) increases inner cell mass (ICM), primitive endoderm (PE) and total cell number in in vitro produced (IVP) bovine blastocysts. Another IL6 family member, leukemia inhibitory factor (LIF), has the potential to produce the same effects of IL6 due to the presence of its receptor in bovine blastocysts. We compared the abilities of LIF and IL6 to increase ICM cell numbers in day 7, 8 and 9 IVP bovine blastocysts. Supplementation with 100 ng/ml LIF from day 5 onward improved blastocyst formation rates on days 7 and 8 similar to what was observed when supplementing 100 ng/ml IL6. However, LIF supplementation did not cause an increase in ICM numbers like was observed after supplementing IL6. On day 9, increases in PE cell numbers were detected after LIF supplementation, but 300 ng/ml LIF was required to achieve the same effect on PE numbers that was observed by providing 100 ng/ml IL6. Collectively, these results show that LIF can mimic at least some of the effects of IL6 in bovine blastocyst.

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