109 EFFECTS OF LIPOLYTIC AGENTS FORSKOLIN, EPINEPHRINE AND CAFFEINE ON EMBRYONIC DEVELOPMENT AND LIPID CONTENT OF BOVINE EMBRYOS PRODUCED IN VITRO

2009 ◽  
Vol 21 (1) ◽  
pp. 154 ◽  
Author(s):  
M. Barcelo-Fimbres ◽  
G. E. Seidel

The objective of this experiment was to evaluate lipid accumulation and embryonic development of bovine morulae treated with different chemicals. A total of 2619 slaughterhouse oocytes from heifers and mature cows were matured in CDM medium (similar to SOF) plus 0.5% fatty acid-free BSA and hormones (M-CDM) for 23 h at 38.5°C in 5% CO2 in air. Frozen–thawed sperm were centrifuged through a Percoll gradient and co-cultured with matured oocytes for 18 h in F-CDM (CDM+heparin). Zygotes were cultured at 38.5°C in 5% CO2/5% O2/90% N2 in CDM-1 with nonessential amino acids, 10 μm EDTA, 0.5% fatty acid free BSA, and 0.5 mm fructose. After 60 h, resulting 8-cell embryos were cultured 120 h in CDM-2 (CDM-1+essential amino acids and 2 mm fructose). A factorial design was used with 7 treatments, 2 ovary sources (cows v. heifers), and 3 bulls (A, B and C) replicated twice for each bull (6 replicates). At Day 2.5 embryo cleavage and 8-cell rates were evaluated, and on Day 6 a total of 755 morulae were randomly assigned to the 7 treatments (control, 2 and 8 mm caffeine, 1 and 4 μm epinephrine, and 10 and 40 μm forskolin). To quantify lipid accumulation, Day 7 blastocysts were fixed and stained with 1 μg mL–1 Nile red dye, after which a digital photograph of the equatorial part of the embryo (including the inner cell mass) was taken at 200×, and fluorescence intensity was measured with Image Pro software from 0 to 255 shades for each pixel (0 = no lipids; 255 = greatest lipid accumulation), as previously reported (Biol. Reprod. 2007 (Suppl. 1), 87–88). Data were analyzed by ANOVA. No differences in cleavage rates (75 v. 68 ± 3.6%) or eight cell rates (61 ± v. 57 ± 2.8%) were found for heifer v. cow oocytes (P > 0.1); however, blastocyst rates per oocyte and per 8-cell embryo were greater for cows than heifers (20 v. 10 ± 2.1%, and 68 v. 35 ± 3.8%, respectively; P < 0.05). Treatments: 2 and 8 mm caffeine produced fewer blastocysts per morula than 1 and 4 μm epinephrine, 10 and 40 μm forskolin and the control (39, 5 v. 54, 49, 48, 54 and 52 ± 5.8%; respectively) (P < 0.01). More lipid content was found in whole embryos and trophoblast of heifer-derived than cow blastocysts (P < 0.05), and forskolin resulted in less lipid content than control, caffeine- and epinephrine-treated morulae in whole embryos, embryonic mass and trophoblasts (P < 0.05; Table 1). In conclusion, mature cows were a better source of oocytes than feedlot heifers for embryonic development. High doses of caffeine were detrimental to embryos, and the addition of the lypolitic agent forskolin reduced lipid content relative to control, caffeine and epinephrine-treated embryos. Table 1.Main effect treatment means of lipid content (arbitrary fluorescence units)

2007 ◽  
Vol 19 (1) ◽  
pp. 189
Author(s):  
Y. H. Choi ◽  
H. D. Harding ◽  
A. D. Obermiller ◽  
K. Hinrichs

Oct-4 is a key transcription factor in the control of early embryonic development and maintenance of a pluripotent cell population. Variation in Oct-4 expression patterns during embryo development have been reported among species, and have been related to the time of placental development in those species. This study was conducted to investigate Oct-4 expression pattern during early embryonic development in the horse, a species with relatively delayed placentation. In vitro-produced embryos were obtained from in vitro-matured oocytes via fertilization by intracytoplasmic sperm injection. Ex vivo blastocysts were recovered from mares that had been artificially inseminated. Oct-4 status was determined by immunocytochemistry; photomicrographs were taken at 4 standardized settings to aid in qualitative comparison of the amount of fluorescence. A total of 106 oocytes and embryos were evaluated. Immature oocytes showed Oct-4 expression in the nucleus and cytoplasm, as did early-cleaved embryos (2 to 5 cells, 1 to 2 days). Oct-4 expression in embryos at 3 to 4 days (6 to 12 cells) decreased and was restricted to the cytoplasm. From 5 to 6 days (15 cells to morulae), Oct-4 intensity increased and was exclusively found in the nuclei. In vitro-produced blastocysts (7 to 8 days) expressed Oct-4 equivalently in the trophectoderm and inner cell mass nuclei; culture for 2 to 3 more days (10 to 11 days) did not alter Oct-4 expression. However, when in vitro-produced blastocysts were transferred to the uteri of mares and recovered after 2 to 3 days (IVP-ET), the embryos showed strong expression of Oct-4 within the inner cell mass and limited expression in the trophectoderm, and a similar pattern was seen for ex vivo-recovered embryos. In bigger embryos (such as a 1779-�m ex vivo embryo and a 1121-�m IVP-ET embryo), the trophectoderm lost staining completely. These results suggest that Oct-4 expression is present in both nucleus and cytoplasm in equine oocytes and early-cleaved embryos as a result of maternal mRNA accumulation. Oct-4 protein decreases over the first few days of embryonic development as these stores are used. The shift to greater expression, in the nucleus only, during further embryo development suggests embryonic genome activation. Oct-4 expression in the trophectoderm of in vitro-produced blastocysts was different from that in blastocysts that had been exposed to the uterus (both ex vivo and IVP-ET); this indicates that differentiation of the trophectoderm is dependent upon factors present in the uterine environment. The Oct-4 expression in the trophectoderm of in vitro-produced equine blastocysts thus appears to be an artifact due to in vitro culture; this finding may be applicable to the reported patterns of Oct-4 expression in embryos of other species. This work was supported by the Link Equine Research Endowment Fund, Texas A&amp;M University.


2016 ◽  
Vol 28 (2) ◽  
pp. 177
Author(s):  
J. Herrick ◽  
A. Greene ◽  
W. Schoolcraft ◽  
R. Krisher

Polyamines are involved in trophectoderm attachment and outgrowth, but little is known about their role in earlier stages of development. The objective of this study was to evaluate the effects of an inhibitor of polyamine synthesis (difluoromethylornithine, DFMO) on development (blastocyst formation and hatching) and cell allocation to the trophectoderm (TE, CDX2-positive) and inner cell mass (ICM, SOX2-positive) in the bovine embryo. Cumulus-oocyte complexes (COCs) were recovered from slaughterhouse ovaries and matured for 24 h in a defined maturation medium (5.0 mM glucose, 0.6 mM cysteine, 0.5 mM cysteamine, 0.1 IU mL–1 FSH, 50 ng mL–1 EGF, and 2.5 mg mL–1 recombinant human albumin). Frozen-thawed spermatozoa were processed by gradient centrifugation and co-incubated (2 × 106 mL–1) with COC [10 COC/50 µL; 7.5 µg mL–1 heparin, 2 mM caffeine, and 8.0 mg mL–1 fatty-acid free (FAF) BSA] for 20 to 22 h. After removing cumulus cells, zygotes were cultured (10 embryos/20 µL) in a medium for cleavage stage bovine embryos (0.5 mM glucose, 0.3 mM pyruvate, 6.0 mM lactate, 0.25 mM citrate, 1.0 mM alanyl-glutamine, 0.25 × MEM nonessential and essential amino acids, 5 µM EDTA, and 8.0 mg mL–1 FAF BSA). After 72 h, embryos with >4 cells were randomly allocated (5 embryos/20 µL) to a culture medium for compaction and blastocyst formation (3.0 mM fructose, 0.1 mM pyruvate, 6.0 mM lactate, 0.5 mM citrate, 1.0 mM alanyl-glutamine, 1× MEM nonessential amino acids, 0.5× MEM essential amino acids, 0.075 mM myo-inositol, and 8.0 mg mL–1 FAF BSA) containing 0 (control), 5, or 10 mM DFMO. Embryonic development was evaluated at 192 h post-insemination (96 h in the second medium containing DFMO treatments), and hatching or hatched blastocysts were fixed for analysis of cell allocation. All data were analysed by ANOVA and P < 0.05 was considered significant. Blastocyst formation and hatching (% of embryos cultured in the presence of treatments) were both inhibited (P < 0.05) when embryos (n = 157/treatment) were cultured with 5 (39.5 ± 3.9%, 14.6 ± 2.8%) or 10 (39.5 ± 3.9%, 14.0 ± 2.8%) mM DFMO compared with embryos cultured without DFMO (53.5 ± 4.0%, 26.1 ± 3.5%). The number of TE cells was also reduced (P < 0.05) in the presence of 5 (121.4 ± 7.2) and 10 (123.6 ± 6.7) mM DFMO compared with embryos cultured without DFMO (152.4 ± 9.7), but the number of ICM cells (45.2 to 54.0) and the total number of cells (TE+ICM, 168.8 to 201.1) were not affected (P > 0.05). In a second experiment (n = 163 to 165/treatment), the negative effects of DFMO on hatching (17.0 ± 2.9%; P < 0.05, v. control, 30.7 ± 3.6%) could be partially reversed when embryos were cultured with both 10 mM DFMO and an exogenous polyamine (100 µM putrescine, 23.0 ± 3.3% DFMO+Put; P > 0.05 v. control). The number of TE cells for embryos cultured with DFMO+Put (153.9 ± 8.7) was intermediate between embryos cultured with (138.0 ± 6.9) or without DFMO (control, 161.6 ± 8.7), but these differences were not significant (P > 0.05). These results provide the first evidence of a role for polyamines during blastocyst formation and hatching of bovine embryos, with specific effects on trophectoderm proliferation and hatching.


2019 ◽  
Vol 31 (1) ◽  
pp. 191
Author(s):  
L. H. Aguiar ◽  
A. C. Denicol

Lipid accumulation decreases cryopreservation survival of in vitro-produced embryos, reducing pregnancy rate after embryo transfer. Fatty acid binding protein 3 (FABP3) plays a role in lipid transport from cumulus cells to the oocyte during maturation. Blocking this transport could reduce lipid content in the oocyte and embryo and increase cryopreservation survival. This preliminary study aimed to test the effect of α-truxillic acid (FABP-I), a chemical molecule that inhibits FABP3/5 action by receptor competition, on lipid content of matured oocytes and blastocysts after culture. Slaughterhouse-derived cumulus-oocyte complexes were matured with 0 (control), 10, 50, 100 and 500nM FABP-I for 22h. In Experiment 1, 346 oocytes in 3 replicates were fixed following maturation and stained with 1μg mL−1 Nile Red to evaluate total lipid content; maturation was assessed by nuclear staining with 10μg mL−1 Hoechst 33342[ACD1]. In Experiment 2, 876 cumulus-oocyte complexes in 5 replicates were matured for 22h under the same concentrations of FABP-I, then fertilized for 18h and cultured for 7 days. Cleavage and blastocyst development were evaluated on Day 2 and 7, respectively. Blastocysts were fixed at Day 7 and stained with Nile Red. Fluorescence intensity was measured in arbitrary units using ImageJ (NIH), and data was analysed using GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA). In Experiment 1, maturation rate did not differ among treatments (70.2±8.7; P=0.7). There were significant effects of treatment, replicate and interaction of treatment by replicate on fluorescence intensity. Compared with control (23.6±0.6), intensity was lowest in oocytes matured with 500nM FABP-I (21.2±0.6; P&lt;0.01) and highest in the 10nM group (26.5±0.6; P&lt;0.01). Staining intensity tended to decrease in the 100nM group (22.1±0.6; P=0.09) and was not different in the 50nM group (24.0±0.7; P=0.6). In Experiment 2, cleavage rate (75.8±2.9; P=0.3) did not differ and blastocyst development tended to be different among treatments (P=0.06). Compared with the control (33.3±4.8), the 500nM group had lower development (17.0±4.8; P&lt;0.03); 10 and 50nM groups had numerically lower (24.7 and 24.0±4.8) and the 100nM group had the highest development rate (37.3±4.8), although either was significant. Treatment tended to affect fluorescence intensity of blastocysts (P=0.07; n=209), and there were significant effects of replicate and interaction between replicate and treatment. Compared with the control (11.7±1.3), fluorescence intensity was lower in the 50nM group (6.8±1.3; P&lt;0.01), whereas 10nM had a tendency for lower intensity (8.3±1.2; P=0.06). Groups 100 and 500nM were not significantly different from controls (9.4±0.9 and 10.7±1.5, respectively). In conclusion, addition of FABP-I up to 500nM did not affect maturation or embryo cleavage but altered blastocyst development. Exposure to 50nM reduced staining intensity in blastocysts without significant decrease in development, whereas 100nM resulted in numerically lower oocyte staining intensity and higher blastocyst development. Future experiments will evaluate cryopreservation survival of embryos treated with FABP-I, and embryo transfer.


2016 ◽  
Vol 28 (2) ◽  
pp. 174
Author(s):  
M. A. Roberts ◽  
L. F. Campos-Chillon ◽  
M. Barceló-Fimbres ◽  
J. L. Altermatt

Current bovine embryo culture methods result in accumulation of lipids and reactive oxygen species, possibly due to sub-optimal metabolic regulation. These effects decrease the cryopreservation survival and implantation potential of in vitro-produced (IVP) embryos. Forskolin has been shown to decrease lipid accumulation, and vitamin K2 (Vit K2) is thought to decrease oxidative stress from in vitro conditions. The aims of this study were (1) to assess lipid content of embryos cultured with or without forskolin and Vit K2 in both continuous and sequential SOF-based medium, and (2) to examine individual and combined effects of forskolin and Vit K2 on mitochondrial polarity. For Experiment 1, a 2 × 2 × 2 factorial design was used to compare culture systems (continuous v. 3-step sequential), additives (no additive v. Vit K2 (0.5 mM at Day 3) plus forskolin (10 µM at Day 5), and blastocyst stage [6 (early) v. 7 (late)] on overall lipid content. For Experiment 2, mitochondrial polarity of stage 7 blastocysts was analysed from the following groups: no additive, Vit K2 (0.5 mM at Day 3), forskolin (10 µM at Day 5), and Vit K2 plus forskolin. IVP embryos (n = 199, Experiment 1; n = 45, Experiment 2) were produced by standard procedures and cultured at 38.5°C in 5% O2, 5% CO2, and 90% N2. For Experiment 1, embryos were stained with 1 μg mL–1 Nile Red, and two images per embryo were taken along the equatorial plane at 40× magnification. For Experiment 2, embryos were stained with 300 nM MitoTracker Red CMX-Rosamine, and 10 images per embryo were acquired by confocal microscopy with a 5-μm step size at 40× magnification. For both experiments, fluorescence intensity (FI) of each image was measured by Image PRO software with embryo controlled for and background fluorescence corrected. Data (Table 1) were analysed by ANOVA and means were compared by Tukey’s HSD. In Experiment 1, embryos cultured with forskolin and Vit K2 showed decreased lipid content in both the early and late stage (P < 0.05), with no effect from culture system (P > 0.05). In Experiment 2, forskolin and Vit K2 individually increased mitochondrial polarity (P < 0.05), but had no combined effect (P > 0.05). In conclusion, these data suggest that while a combination of forskolin and Vit K2 as media additives reduces lipid accumulation, the interaction between these metabolic regulators may negate their individual effects on mitochondrial polarity. Table 1.Fluorescence intensity of Nile Red and MitoTracker Red dyes between treatment groups


Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 5046-5054 ◽  
Author(s):  
Bárbara Loureiro ◽  
Luciano Bonilla ◽  
Jeremy Block ◽  
Justin M. Fear ◽  
Aline Q. S. Bonilla ◽  
...  

In this study, we tested the role of colony-stimulating factor 2 (CSF2) as one of the regulatory molecules that mediate maternal effects on embryonic development during the preimplantation period. Our objective was to verify effects of CSF2 on blastocyst yield, determine posttransfer survival, and evaluate properties of the blastocyst formed after CSF2 treatment. In vitro, CSF2 increased the percentage of oocytes that became morulae and blastocysts. Blastocysts that were treated with CSF2 tended to have a greater number of inner cell mass cells and had a higher ratio of inner cell mass to trophectoderm cells. There was no effect of CSF2 on the incidence of apoptosis. Treatment with CSF2 from d 5 to 7 after insemination increased embryonic survival as indicated by improved pregnancy rate at d 30–35 of gestation. Moreover, treatment with CSF2 from either d 1–7 or 5–7 after insemination reduced pregnancy loss after d 30–35. Results indicate that treatment with CSF2 can affect embryonic development and enhance embryo competence for posttransfer survival. The fact that treatment with CSF2 during such a narrow window of development altered embryonic function much later in pregnancy suggests that CSF2 may exert epigenetic effects on the developing embryo that result in persistent changes in function during the embryonic and fetal periods of development.


2019 ◽  
Vol 64 (No. 12) ◽  
pp. 473-482
Author(s):  
Sang Hwan Kim ◽  
Jong Taek Yoon

In this study, we examined whether serum-free and serum-containing media affect matrix metalloproteinase (MMP) activity with respect to embryonic development, and whether MMP expression is correlated with the development of in vitro fertilized eggs. When oocytes were cultured in serum-free medium (containing polyvinylpyrrolidone) and serum (foetal bovine serum)-containing medium, the generation of meiosis 2 (MII) oocytes was 76% and 87.5%, respectively (P &lt; 0.05). After in vitro fertilization using mature oocytes, we observed 39.72% and 64.05% of cleaved oocytes in serum-free and serum-containing groups, respectively (P &lt; 0.05). Our analysis revealed differential expression and activity of MMPs. The serum-containing group showed high MMP-9 activity during oocyte maturation and development of in vitro produced embryos, with particularly high activity in the inner cell mass zone of the embryos. Therefore, this study suggests that the presence or the absence of serum will affect the activity of MMPs, which can be used to measure the rate of embryonic development.


2018 ◽  
Author(s):  
V Najafzadeh ◽  
H Henderson ◽  
R Martinus ◽  
B Oback

ABSTRACTIncreasing evidence suggests that pluripotency is a metabolically specialised state. In mouse, inner cell mass (ICM) cells and ICM-derived pluripotent stem cells (PSCs) critically depend on catabolising the amino acid threonine, while human PSCs require leucine, lysine, methionine or tryptophan. However, little is known about the specific amino acid requirements of putative pluripotent cells in bovine. We selectively depleted candidate essential amino acids (EAAs) from individually cultured bovine embryos to study their role in blastocyst development. Depleting one (-T, -M), two (-MT, -CM, -CT, -IL, -IK, -KL) or three (-CMT, -IKL) EAAs from chemically defined protein-free culture medium did not affect the morula-to-blastocyst transition from day five (D5) to D8 in vitro. By contrast, removing six (-CIKLMT, -FHRYVW), nine (+CMT, +IKL), eleven EAAs (+T, +M) or all twelve EAAs increasingly impaired blastocyst development. As no clear candidate emerged from this targeted screen, we focussed on threonine dehydrogenase (TDH), which catalyses threonine catabolism. TDH mRNA and protein was present at similar levels in trophectoderm (TE) and ICM but absent from several adult somatic tissues. We then treated morulae with an inhibitor (Qc1) that blocks TDH from catabolising threonine. Continuous exposure to Qc1 reduced total and high-quality blastocyst development from 37% to 26% and 18% to 8%, respectively (P<0.005). This was accompanied by ∼2-fold decrease in ICM, TE and total cell numbers (P<0.005), which was due to increased autophagy (P<0.05). At the same time, ICM-(NANOG) and TE-restricted (KRT8) genes were up-and down-regulated, respectively (P<0.05). In summary, bovine blastocyst viability depended on TDH-mediated threonine catabolism. However, ICM and TE cells did not metabolically differ in this regard, highlighting species-specific connections between metabolism and pluripotency regulation in mouse vs cattle.


2004 ◽  
Vol 16 (2) ◽  
pp. 209 ◽  
Author(s):  
F.L. Du ◽  
A. Dinnyes ◽  
L.Y. Sung ◽  
J. Xu ◽  
S. Jiang ◽  
...  

Advancement in vitrification of in vitro-produced bovine embryos will benifit the cattle breeding and production industry. The objective was to evaluate whether bilateral (double) embryo transfers (ET) can improve pregnancy rate compared to ipsilateral (single) transfers. Bovine cumulus-oocyte complexes collected from slaughterhouse ovaries were matured for 20–22h, and subsequently subjected to a standard Brackett and Oliphant in vitro fertilization (IVF). Six hours after IVF, embryos denuded of cumulus were cultured in defined CR1 medium supplemented with essential and non-essential amino acids (CR1aa), plus 6mgmL−1 BSA for 2 days at 39°C under 5% CO2, 5% O2 and 90% N2, and then cultured in CR1aa medium supplemented with 7.5% FBS for a further 5 days on bovine cumulus monolayers. Expanded blastocysts with tighter compaction of the inner cell mass (quality 1) were selected on Day 7 for cryopreservation via modified solid surface vitrification (Dinnyes et al., 2000 Biol. Reprod. 513–8). Vitrification solution contained HEPES-buffered TCM199 supplemented with 20% FBS, ethylene glycol and dimethylsulphoxide. A droplet of 1–2μL vitrification solution containing 4–5 blastocysts was dropped directly onto a cooled surface within 30s after 3-min incubation in equilibration solution. Prior to ET, embryos were warmed and subsequently washed several times in 0.25M sucrose rehydration solution and M199+7.5% FBS medium. The warmed embryos from initial trials were cultured for 2 to 72h to evaluate their viability after vitrification. During ET trails, vitrified embryos were loaded into transfer straws (one embryo per straw) after warming. The treatments were as following, (1) single transfers, one embryo was transferred into the horn ipslateral to CL; (2) double transfers, one embryo was transferred by non-surgical means into each uterine horn of a synchronous recipient on Day 7. ET trails were conducted in both the USA (double transfers) and China (single v. double transfers). Pregnancy was determined by palpation per rectum around Day 70 after transfer. The data were compared by Student’s t-test. The survival rate of vitrified IVF embryos reached as high as 91.4% (n=256) 2h post-warming, and hatching rate was 70.7% (n=154) 72h after culture in vitro, respectively. The data (Table 1) show that double transfers resulted in a significantly higher pregnancy rate than did single transfers (P&lt;0.05). With double transfers, a higher pregnancy rate was achieved in the USA than in China (76.2% v. 45.6%, P=0.079). This study confirms that double embryo transfers can improve the pregnancy outcome after ET, perhaps because bilateral placement of embryos may increase embryonic signals to the maternal environment. Further evaluation of gestation length, single/twin conception and calving difficulty is under investigation. Table 1 Pregnancy rate (Day 70) of vitrified bovine IVF embryos following single and double transfer


2007 ◽  
Vol 19 (1) ◽  
pp. 205
Author(s):  
E. Gómez ◽  
A. Rodríguez ◽  
C. De Frutos ◽  
J. N. Caamaño ◽  
N. Facal ◽  
...  

Neurotrophins (NTs) mediate human embryonic stem (hES) cell survival and may also improve methods for hES cell derivation (Pyle et al. 2006 Nature Biotech. 24, 344–350) and quality of the inner cell mass (ICM). We searched published microarray data sets for tyrosine kinase receptors (TRK) (geo data base: GSM27469, GSM27470, GSM27471). The analysis suggested that bovine embryos in vitro at unspecified stages express TRKA, for nerve growth factor (NGF); TRKC, for neurotrophin-3 (NT3); and TRKB, for both neurotrophin-4 (NT4) and brain-derived neurotrophic factor (BDNF). NTs functionally cooperate among them and also with basic fibroblast growth factor (bFGF) (Pyle et al. 2006; Logan et al. 2006 Brain 129, 490–502). Experiments in progress include detection of TRK expression by RT-PCR at defined development stages, and analysis of embryonic development with NTs and without bFGF. In this work we cultured embryos matured and fertilized in vitro from slaughterhouse oocytes for 8 days in SOF medium with 6 g L-1 BSA and 2 ng mL-1 bFGF (negative control). Development was monitored and cells were differentially counted in the ICM and trophectoderm (TE) of expanded and hatched blastocysts. NTs were used during the whole culture at 20 ng mL-1 as single (4 experimental groups: NGF, NT3, NT4, and BDNF) or as pooled (1 group) NT compounds. Data (5 replicates; 1403 oocytes) were processed by GLM and Duncan&apos;s test, and expressed as LSM � SE (a,b: P &lt; 0.05). At Day 3, no differences were found at the 5- to 8-cell stage, but NT3 and NT4 increased the proportions of embryos at the 8- to 16-cell stage (19.1 � 2.2 and 20.5 � 2.2, respectively, vs. 12.9 � 2.2 to 13.7 � 2.2 within the other groups). On Day 6, NT4 yielded more morulae than controls, BDNF, and NGF (35.3 � 2.7 vs. 26.1 � 2.7, 27.4 � 2.7, and 27.8 � 2.7, respectively), and did not differ from the other groups. NT4 produced more total Day 7 blastocysts than NT3 and BDNF (12.5 � 2.2 vs. 8.1 � 2.2 and 9.9 � 2.2, respectively), whereas there were no differences within medium and expanded blastocysts and Day 8 blastocysts. Proportions of morulae that formed blastocysts were appreciably lower than in concomitant experiments without bFGF. Pooled NTs showed decreased values as compared to some single NTs within the ICM [13.0 � 4.0 vs. 29.1 � 4.6 (NT3) and 24.9 � 4.3 (NGF)], the TE [89.0 � 8.4 vs. 120 � 11.9 (BDNF)], total cells [102.0 � 8.5 vs. 134.0 � 9.9 (NT3), and 140.0 � 12.1 (BDNF)], and tended to differ (P = 0.08) within ICM/total cells [13.1 � 3.1 vs. 21.6 � 3.6 (controls) and 22.2 � 3.6 (NT3)]. Controls differed from BDNF (TE: 88.1 � 9.8 vs. 120.2 � 11.9; total cells: 110.8 � 10.0 vs. 140.0 � 12.1, respectively), and from NT4 for ICM/total cells (21.6 � 3.6 vs. 11.5 � 2.9, respectively). NT4 is likely to exert a role during early embryonic development. However, these blastocysts showed decreased cell counts in the ICM, probably reflected in the pooled NTs group. Targeting proliferation stimuli specifically to the ICM is difficult to get when the ICM is enclosed in the embryo, in contrast with the isolated ICM or the derived stem cells. This work was supported by Grant AGL2005-04479.


2010 ◽  
Vol 22 (1) ◽  
pp. 351
Author(s):  
J. F. Lima-Neto ◽  
G. H. M. Araujo ◽  
M. L. Alvarenga ◽  
C. F. Moya-Araujo ◽  
I. D. P. Blanco ◽  
...  

Stem cells can originate from embryo, fetus, and adults tissues. Adult stem cells are present in almost all organs and are responsible for tissue regeneration and repair. The mesenchymal stem cells (MSC) are multipotent cells present in the bone marrow. The plasticity of these cells allows them to be used in cell therapy because they have the potential to differentiate into several tissues with mesenchymal origin. On the other hand, embryonic stem cells (ESC) have the ability to differentiate into the 3 embryonic tissues (endoderm, mesoderm, and ectoderm) generating all kinds of tissue in the living organism. Embryonic stem cells can be maintained in their undifferentiated state when cultured in vitro in the presence of the leukemia inhibitory factor (LIF) and over a feeder layer composed normally by mouse fibroblasts. Because of the small number of articles studying equine ESC, the current experiment aimed to compare the utilization of equine fibroblasts and equine MSC as feeders for inner cell mass (ICM) culture. Eighteen blastocysts were collected on Day 7 after ovulation from 5 fertile mares that had been artificially inseminated. The embryos were placed in a petri dish with Dulbecco’s phosphate buffered saline + 10% FCS, and the ICM was mechanically removed using 2 insulin needles. The ICM was then transferred to one well of 24 well plates containing either an equine fibroblast monolayer (9 embryos) or a MSC monolayer (9 embryos). Both feeders layers were inactivated with 10 μg mL-1 mitomycine C, and the cell concentration was 140 000 cells/well. The culture media utilized was the DMEM/F12 with 20% FCS, 1% essential amino acids, 1% nonessential amino acids, 0.1 mM β-mercaptoetanol, 10 ng mL-1 LIF, penicillin, streptomycin, and amphotericin B. The ICM was cultured during 5 days for the adherence to the plate, and the media was change every 2 days. Data was analyzed by ANOVA. Results indicated no significant differences between the use of equine fibroblasts or MSC as feeder layer to support equine ICM in culture. The expansion of the ICM cells was observed after 10 to 12 days in culture in 44.4% (4/9) of ICM cultured in MSC monolayer and 55.5% (5/9) of the ICM cultured over a fibroblast layer. The formation of embryoid body-like structures were observed after the second passage (5-7 days in culture) in 50% (2/4) of embryos using MSC feeders and in 40% of embryos (2/5) for which fibroblasts were used. Cultures were then positively marked with the Oct 4 antibody for characterization of the undifferentiated lineage. The results of the current experiment showed that although further patronization of the culture system is still needed, both fibroblasts and MSC are suitable as feeders for the culture of equine ICM when aiming to establish ESC lineage in vitro. Financial support was provided by FAPESP and CNPq.


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