scholarly journals 113 THE DISTRIBUTION OF THE LEPTIN PROTEIN WITHIN BOVINE OOCYTES AND PRE-IMPLANTATION EMBRYOS MATURED AND FERTILIZED IN VITRO

2005 ◽  
Vol 17 (2) ◽  
pp. 207
Author(s):  
Z. Madeja ◽  
D. Lechniak ◽  
J. Peippo ◽  
M. Switonski
Keyword(s):  
Protein Localization ◽  
Cell Mass ◽  
Immunofluorescent Staining ◽  
Preimplantation Embryos ◽  
Trophoblast Invasion ◽  
Protein Distribution ◽  
Santa Cruz ◽  
Animal Pole ◽  
Bovine Oocytes

It has recently been documented that leptin regulates processes linked to reproduction including preimplantation development, embryo implantation (trophoblast invasion), and fetal growth. Transcripts for the leptin gene (LEP) and the leptin receptor gene (LEPR) have been identified in ovary, testis, placenta, endometrium, ovarian follicles, and oocytes, and also in mouse, rat, human, and bovine pre-implantation embryos. Moreover, the leptin protein was detected in mouse and human oocytes and embryos, and its localization was polarized. The distribution of regulatory proteins within oocytes and pre-implantation embryos is critical for early mammalian development, such as determination of the animal pole and the establishment of the trophoblast and the inner cell mass cells (ICM). So far there is no published evidence concerning this phenomenon in bovine oocytes and embryos. Therefore, the aim of this work was to analyze the leptin protein distribution within bovine oocytes and preimplantation embryos matured and fertilized (in vitro). The material for this work consisted of oocytes collected from slaughterhouse ovaries and sperm collected from AI bulls. In vitro oocyte maturation and fertilization were carried out according to the method described by Makarevich and Markkula (2002 Biol. Reprod. 66, 386–392). The preliminary experiment of leptin protein localization by immunofluorescent staining included immature and matured oocytes and blastocysts. Oocytes and embryos were fixed in PBS containing 4% paraformaldehyde and reacted with affinity-purified polyclonal rabbit primary antibody directed against leptin (0.1 mg/mL; Ob (Y20), Santa Cruz Biotechnology Inc., Santa Cruz, CA, USA); and then exposed to secondary goat-anti-rabbit antibody (1.0 mg/mL; Santa Cruz Biotechnology Inc.)-fluorescein isothiocyanate (FITC) conjugate. Finally, chromatin was visualized by propidium iodide staining (0.5 μg/mL). Slides were examined under a conventional fluorescence microscope (Nikon) and confocal microscope (Zeiss). The preliminary results demonstrate that the distribution of leptin differed between immature and mature oocytes: it was spherical in immature oocytes (a rim beneath the oolemma) whereas it became evenly distributed after maturation. In blastocysts, leptin signals were present inboth the trophoblast cells and in the ICM cells. This is in contrast with studies on mouse embryos which showed the presence of the LEP protein in the trophoblast only. Future experiments will include studies of embryos at the 2-cell, 4-cell, 8–16-cell, and morula stages. The present study for the first time shows the pattern of leptin protein distribution within bovine oocytes and preattachment embryos.

170 EXPRESSION PATTERN OF THE Sox2 GENE IN BOVINE OOCYTES AND IN VITRO-DERIVED EMBRYOS

2008 ◽  
Vol 20 (1) ◽  
pp. 165 ◽  
Author(s):  
T. A. L. Brevini ◽  
S. Antonini ◽  
F. Cillo ◽  
G. Pennarossa ◽  
S. Colleoni ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Inner Cell Mass ◽  
False Negative ◽  
Cell Mass ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Developmental Potential ◽  
Sox2 Expression ◽  
Bovine Oocytes

Sox2 is a member of the Sox (SRY-related HMGbox) family. It acts to maintain developmental potential and marks the pluripotent lineage of the early mouse embryo; in particular, as in the case of Oct-4 and Nanog, Sox2 is expressed specifically in the inner cell mass (ICM) and in the epiblast of this species. Moreover, it plays an important role in the transcription network that maintains stem cell pluripotency, interacting with other factors such as Oct-4 and Nanog. Little information is available on this gene in bovine; therefore aims of the present study were: a) to identify and characterize the Sox2 expression profile in bovine oocytes and preimplantation embryos; and b) to investigate its expression pattern in ICM and trophectoderm (TE). Bovine oocytes and embryos were obtained by in vitro maturation and fertilization; blastocysts at Day 7 post-insemination underwent microsurgery to separate TE from ICM. mRNA was isolated from 3 pools, each consisting of 5 MII oocytes, 2-, 4-, 8-, and 16-cell embryos, morulae, blastocysts, ICMs, and TEs. Semi-quantitative analysis of Sox2 expression was performed in the exponential phase of PCR amplification using rabbit globin as exogenous control. Data were analyzed with one-way ANOVA, followed by multiple pairwise comparisons with Tukey test (SigmaStat 2.03, SPSS, Inc., Chicago, IL, USA). Values are presented as mean � SEM and differences of P ≤ 0.05 are considered significant. In order to rule out false negative results, PCR amplifications of isolated ICMs and TEs were extended to the plateau phase. Fragment identity was confirmed by sequencing. Comparison of bovine Sox2 cDNA sequence (EMBL AM774325) with databases revealed a 98%, 93%, and 87% homology with sheep, human, and mouse, respectively. Sox2 mRNA was detectable in oocytes as well as in embryos at the different developmental stages analyzed. Semi-quantitative expression studies revealed that Sox2 was present as both maternal and embryonic transcript; in particular, a statistically significant increase from the 8-cell stage, concomitant with embryo genome activation, was observed. Differently from the mouse, Sox2 was expressed in both bovine ICM and TE, resembling the profile previously shown for Oct-4 (van Eijk et al. 1999 Biol. Reprod. 60, 1093–1103), and suggesting that Sox2 expression might be regulated by Oct-4 also in bovine, as described in mouse and human. These findings also suggest that its expression may become restricted to the ICM only at the expanded hatched stage, as previously described for Oct-4 in pig embryos (Vejlsted et al. 2006 Mol. Reprod. Dev. 73, 709–718). This work was supported by PRIN 2006, FIRST 2005, TECLA-MIUR, and EUROSTELLS-ESF.

Enhancement of histone acetylation by trichostatin A during in vitro fertilization of bovine oocytes affects cell number of the inner cell mass of the resulting blastocysts

Zygote ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Shuntaro Ikeda ◽  
Atsuhiro Tatemizo ◽  
Daisaku Iwamoto ◽  
Shunji Taniguchi ◽  
Yoichiro Hoshino ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Inner Cell Mass ◽  
Trichostatin A ◽  
Cell Mass ◽  
Reproductive Technologies ◽  
Cell Number ◽  
Preimplantation Embryos ◽  
Blastocyst Development ◽  
Bovine Oocytes

SummaryHistone acetylation is one of the major mechanisms of epigenetic reprogramming of gamete genomes after fertilization to establish a totipotent state for normal development. In the present study, the effects of trichostatin A (TSA), an inhibitor of histone deacetylase, during in vitro fertilization (IVF) of bovine oocytes on subsequent embryonic development were investigated. Cumulus-enclosed oocytes obtained from slaughterhouse bovine ovaries were matured in vitro and subjected to IVF in a defined medium supplemented with 0 (control), 5, 50, and 500 nM TSA for 18 h. After IVF, presumptive zygotes were cultured in modified synthetic oviductal fluid (mSOF) medium until 168 h postinsemination (hpi). Some oocytes were immunostained using antibody specific for histone H4-acetylated lysine 5 at 10 hpi. Cleavage, blastocyst development and cell number of inner cell mass (ICM) and trophectoderm (TE) of blastocysts were assessed. TSA treatment enhanced histone acetylation that was prominent in decondensed sperm nuclei. TSA did not affect the postfertilization cleavage, blastocyst rates, and TE cell number. However, it significantly enhanced ICM cell number (p < 0.05). These results indicate that TSA treatment during IVF of bovine oocytes does not affect blastocyst development but alters the cell number of ICM, suggesting that overriding epigenetic modification of the genome during fertilization has a carryover effect on cell proliferation and differentiation in preimplantation embryos. Thus, further environmental quality controls in assisted reproductive technologies are needed in terms of factors which affect chromatin remodelling.

scholarly journals Testis-Specific SEPT12 Expression Affects SUN Protein Localization and is Involved in Mammalian Spermiogenesis

2019 ◽  
Vol 20 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chung-Hsin Yeh ◽  
Ya-Yun Wang ◽  
Shi-Kae Wee ◽  
Mei-Feng Chen ◽  
Han-Sun Chiang ◽  
...  
Keyword(s):  
Male Infertility ◽  
Nuclear Membrane ◽  
Sperm Count ◽  
Protein Localization ◽  
Cancer Cell Line ◽  
Structural Defects ◽  
Preimplantation Embryos ◽  
Severe Oligozoospermia ◽  
Vitro Fertilization

Male infertility is observed in approximately 50% of all couples with infertility. Intracytoplasmic sperm injection (ICSI), a conventional artificial reproductive technique for treating male infertility, may fail because of a severe low sperm count, immotile sperm, immature sperm, and sperm with structural defects and DNA damage. Our previous studies have revealed that mutations in the septin (SEPT)-coding gene SEPT12 cause teratozoospermia and severe oligozoospermia. These spermatozoa exhibit morphological defects in the head and tail, premature chromosomal condensation, and nuclear damage. Sperm from Sept12 knockout mice also cause the developmental arrest of preimplantation embryos generated through in vitro fertilization and ICSI. Furthermore, we found that SEPT12 interacts with SPAG4, a spermatid nuclear membrane protein that is also named SUN4. Loss of the Spag4 allele in mice also disrupts the integration nuclear envelope and reveals sperm head defects. However, whether SEPT12 affects SPAG4 during mammalian spermiogenesis remains unclear. We thus conducted this study to explore this question. First, we found that SPAG4 and SEPT12 exhibited similar localizations in the postacrosomal region of elongating spermatids and at the neck of mature sperm through isolated murine male germ cells. Second, SEPT12 expression altered the nuclear membrane localization of SPAG4, as observed through confocal microscopy, in a human testicular cancer cell line. Third, SEPT12 expression also altered the localizations of nuclear membrane proteins: LAMINA/C in the cells. This effect was specifically due to the expression of SEPT12 and not that of SEPT1, SEPT6, SEPT7, or SEPT11. Based on these results, we suggest that SEPT12 is among the moderators of SPAG4/LAMIN complexes and is involved in the morphological formation of sperm during mammalian spermiogenesis.

scholarly journals Early Embryonic Lethality of Mice Lacking the Essential Protein SNEV

2007 ◽  
Vol 27 (8) ◽  
pp. 3123-3130 ◽  
Author(s):  
Klaus Fortschegger ◽  
Bettina Wagner ◽  
Regina Voglauer ◽  
Hermann Katinger ◽  
Maria Sibilia ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Replicative Senescence ◽  
Inner Cell Mass ◽  
Umbilical Vein ◽  
Cell Mass ◽  
Preimplantation Embryos ◽  
Proliferative Potential ◽  
Mouse Development

ABSTRACT SNEV (Prp19, Pso4, NMP200) is a nuclear matrix protein known to be involved in pre-mRNA splicing, ubiquitylation, and DNA repair. In human umbilical vein endothelial cells, SNEV overexpression delayed the onset of replicative senescence. Here we analyzed the function of the mouse SNEV gene in vivo by employing homologous recombination in mice and conclude that SNEV is indispensable for early mouse development. Mutant preimplantation embryos initiated blastocyst formation but died shortly thereafter. Outgrowth of SNEV-null blastocysts showed a lack of proliferation of cells of the inner cell mass, which subsequently underwent cell death. While SNEV-heterozygous mice showed no overt phenotype, heterozygous mouse embryonic fibroblast cell lines with reduced SNEV levels displayed a decreased proliferative potential in vitro. Our experiments demonstrate that the SNEV protein is essential, functionally nonredundant, and indispensable for mouse development.

scholarly journals Selective degradation of maternal and embryonic transcripts in in vitro produced bovine oocytes and embryos using sequence specific double-stranded RNA

Reproduction ◽  
2006 ◽  
Vol 131 (5) ◽  
pp. 861-874 ◽  
Author(s):  
Korakot Nganvongpanit ◽  
Heike Müller ◽  
Franca Rings ◽  
Michael Hoelker ◽  
Danyel Jennen ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Polar Body ◽  
Cell Mass ◽  
Free Water ◽  
Double Stranded Rna ◽  
Immature Oocytes ◽  
Selective Degradation ◽  
First Polar Body ◽  
Bovine Oocytes

RNA interference (RNAi) has been used for selective degradation of an mRNA transcript or inhibiting its translation to a functional protein in various species. Here, we applied the RNAi approach to suppress the expression of the maternal transcript C-mos and embryonic transcripts Oct-4 in bovine oocytes and embryos respectively, using microinjection of sequence-specific double-stranded RNA (dsRNA). For this, 435 bp C-mos and 341 bp Oct-4 dsRNA were synthesized and microinjected into the cytoplasm of immature oocytes and zygotes respectively. In experiment 1, immature oocytes were categorized into three groups: those injected with C-mos dsRNA, RNase-free water and uninjected controls. In experiment 2,in vitroproduced zygotes were categorized into three groups: those injected with Oct-4 dsRNA, RNase-free water and uninjected controls. The developmental phenotypes, the level of mRNA and protein expression were investigated after treatment in both experiments. Microinjection of C-mos dsRNA has resulted in 70% reduction of C-mos transcript after maturation compared to the water-injected and uninjected controls (P<0.01). Microinjection of zygotes with Oct-4 dsRNA has resulted in 72% reduction in transcript abundance at the blastocyst stage compared to the uninjected control zygotes (P<0.01). Moreover, a significant reduction in the number of inner cell mass (ICM) cells was observed in Oct-4 dsRNA-injected embryos compared to the other groups. From oocytes injected with C-mos dsRNA, 60% showed the extrusion of the first polar body compared to 50% in water-injected and 44% in uninjected controls. Moreover, only oocytes injected with C-mos dsRNA showed spontaneous activation. In conclusion, our results demonstrated that sequence-specific dsRNA can be used to knockdown maternal or embryonic transcripts in bovine embryogenesis.

396 Oct-4 EXPRESSION IN CAT INNER CELL MASS-DERIVED CELLS CULTURED IN MEDIUM WITH DIFFERENT PROTEIN SOURCES

2010 ◽  
Vol 22 (1) ◽  
pp. 354
Author(s):  
T. S. Rascado ◽  
J. F. Lima-Neto ◽  
S. E. R. S. Lorena ◽  
B. W. Minto ◽  
F. C. Landim-Alvarenga
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Inner Cell Mass ◽  
Culture Media ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Domestic Cat ◽  
Santa Cruz

The domestic cat can be used as a biological model for humans because of similarities in some disease and genetically transmitted conditions. Embryonic stem cells might complete nuclear reprogramming more efficiently than somatic cells and, therefore, are potentially useful for increasing interspecific cloning success. The objective of this study was to establish an effective culture system for inner cell mass (ICM)-derived cells in the domestic cat, testing the ability of the ICM to attach to the culture dish and to form embryonic stem cell colonies in the presence of fetal calf serum (FCS) and Knockout serum (KS). Moreover, knowing that the transcription factor Oct-4 is important for the maintenance of pluripotency in human and murine embryonic stem cells, the expression of this factor was evaluated in in vitro-produced blastocyst and in the attached ICM. Domestic cat oocytes were matured, fertilized, and cultured in vitro until the blastocyst stage. The ICM was mechanically isolated (n = 60) using a scalpel blade and transferred to a monolayer of chemically inactivated cat fibroblasts with 10 μg mL-1 mitomicin C. The base culture media (BM) was DMEM/F12 supplemented with nonessential amino acids, glutamine, leukemia inhibitory factor, fibroblast growth factor-2, 2-mercaptoethanol, and antibiotics. Three groups were tested: G1 = BM with 20% FCS (20); G2 = BM with 20% KS (20); G3 = BM with 15% FSC and 5% KS (20). Culture was performed in a 5% CO2 in air incubator at 38.5°C. No statistical difference was observed among groups in relation to ICM attachment (chi-square, P > 0.05). Ninety percent of the ICM presented good adhesion after 3 days of culture and started to grow in all media tested. However, until now, no good colonies were formed. Fifteen blastocysts and 10 attached ICM were fixed in 3% paraformaldehyde and permeabilized in 0.2% triton X-100 in PBS. Subsequently, to block nonspecific binding of the primary antibody, the preadsorption for 2 h at room temperature with OCT4 blocking peptide (sc-8628P, Santa Cruz Biotechnology, Santa Cruz, CA, USA) was used. Samples were incubated with Oct4 antibody (N-19 : sc 8628, Santa Cruz Biotechnology) and with the appropriate secondary antibody (A21431, Invitrogen) and examined by fluorescence microscopy. Oct4 protein was detected both in the ICM and trophoderm cells, and it was distributed in cytoplasm and nuclei. These embryos were also stained with Hoechst 33342. Although further standardization of the culture media is needed, it seems that the KS can be replaced by FCS in cat embryonic stem cell culture. Furthermore, the immunostain of the trophoderm with Oct-4 indicates a difference in the expression of this factor when compared with its expression on human and murine blastocysts. This could be related to in vitro production, or Oct 4 is not a good pluripotency marker for cat embryos and cat embryonic stem cell, consequently. This fact has been noted in goat, bovine, and porcine embryos. Acknowledgment is given to FAPESP.

scholarly journals Gene expression and protein distribution of leptin and its receptor in bovine oocytes and preattachment embryos produced in vitro

animal ◽  
2009 ◽  
Vol 3 (4) ◽  
pp. 568-578 ◽  
Author(s):  
Z.E. Madeja ◽  
E. Warzych ◽  
J. Peippo ◽  
D. Lechniak ◽  
M. Switonski
Keyword(s):  
Gene Expression ◽  
Protein Distribution ◽  
Bovine Oocytes

179 EFFECTS OF AN ENDOCANNABINOID, ANANDAMIDE, ON BOVINE BLASTOCYST DEVELOPMENT IN VITRO

2006 ◽  
Vol 18 (2) ◽  
pp. 197
Author(s):  
M. Y. Turco ◽  
K. Matsukawa ◽  
P. Loi ◽  
G. Ptak
Keyword(s):  
Cell Proliferation ◽  
Cell Viability ◽  
Protein Localization ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Santa Cruz ◽  
Negative Effects ◽  
Blastocyst Development ◽  
Development In Vitro

Cannabinoids cause many adverse effects on reproductive functions including fetal loss and pregnancy failure (Paria et al. 1995 PNAS 92, 9460–9464). N-arachidonylethanolamine (anandamide), an endogenous cannabinomimetic lipid derivative, binds with high affinity to brain type and spleen type cannabinoid receptors (CB1-R and CB2-R) and mimics most of the effects of Δ9-tetrahydrocannabinol [(−)THC], a psychoactive derivative of marijuana. In this study, we investigated the effects of anandamide on ovine blastocyst development in vitro. In vitro-matured oocytes were chemically activated and cultured to the blastocyst stage in our standard media (Ptak et al. 1999 Biol. Reprod. 61, 1568–1574). The development rate of blastocysts was 41%. Day 7 blastocysts were exposed to 28 nM anandamide with or without 20 nM SR141716A (an antagonist of CB1-R) for 48 h. In Experiment 1, we examined the CB1-R protein localization on blastocysts by anti CB1-R antibody (Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA). In Experiment 2, to investigate the possible effect of anandamide on blastocyst development, we used the cell viability assay by propidium iodide, a cell proliferation assay (5-bromo-1′-deoxyuridine incorporation), and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay (Qbiogene, Inc., Carlsbad, CA, USA). Data were analyzed by one-way ANOVA. CB1-R signals were detected on ovine blastocysts, and these signals were effectively improved in the anandamide co-cultured group. The results of Experiment 2 are summarized in Table 1. Our results demonstrate that CB1-R was expressed in the ovine blastocyst, and anandamide exerts negative effects on in vitro blastocyst development by inhibiting cell proliferation and increasing apoptotic rate, but not cell viability. Furthermore, SR141716A can effectively block the negative effects of anandamide. Table 1. Effect of anandamide (AEA) on sheep blastocyst development assessed by viability, cell proliferation, and TUNEL staining assays

63 QUALITY OF BOVINE EMBRYOS PRODUCED IN VITRO FROM IMMATURE OOCYTES TREATED WITH A SUBLETHAL HYDROSTATIC PRESSURE

2013 ◽  
Vol 25 (1) ◽  
pp. 179
Author(s):  
C. Díez ◽  
B. Trigal ◽  
J. N. Caamaño ◽  
M. Muñoz ◽  
E. Correia ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Embryo Development ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Survival Rates ◽  
Pressure Treatment ◽  
Cell Counts ◽  
Development Rates ◽  
Bovine Oocytes

High hydrostatic pressure (HHP) treatment of immature porcine oocytes improves embryo development rates and cell numbers (Pribenszky et al. 2008 Anim. Reprod. Sci. 106, 200–207). However, it is unknown if similar effects can be obtained with bovine oocytes and how HHP affects cryopreservation of the developed blastocysts. In this work, we analyzed the effect of an HHP treatment (Cryo-Innovation Ltd., Budapest, Hungary) on bovine cumulus–oocyte complex (COC) as determined by their developmental ability and embryo quality. Immature COC were submitted to a pressure treatment (200 bar, 1 h at 37°C; HHP group; n = 643) in HEPES-buffered TCM199. Simultaneously, a group of COC was held at 37°C for 1 h (T group; n = 304) in HEPES-buffered TCM199, while other COC were untreated (n = 1182). After in vitro maturation, COC were fertilized in vitro (IVF) and cultured in modified SOF + 6 g L–1 BSA (Holm et al. 1999 Theriogenology 52, 683–700), and embryo development was recorded (5 replicates). Day 7 and 8 excellent- and good-quality embryos were selected for vitrification (cryologic vitrification method; Trigal et al. 2012 Theriogenology 10.1016/j.theriogenology.2012.06.018). After warming, vitrified blastocysts were cultured in modified SOF + 6 g L–1 BSA + 10% FCS for 48 h (3 replicates). Those blastocysts hatching after warming (at 24 and 48 h) were fixed and stained for differential cell counts. Data were analyzed by ANOVA and REGWQ test and are presented as least squares means ± standard error. The HHP-treated oocytes showed increased development rates on Day 3 (Day 3 ≥5-cell embryos: 64.5 ± 2.9a, 53.4 ± 3.9b, 56.7 ± 2.2b for HHP, T, and untreated groups, respectively; a v. b: P < 0.05); however, D8 blastocyst rates were not affected by the pressure treatment (28.5 ± 1.6, 26.4 ± 2.2, and 27.8 ± 1.3 for HHP, T, and untreated groups, respectively). Treatment did not affect survival rates to vitrification (2-h re-expansion rates: 100 ± 6.7, 100 ± 6.7, and 95.4 ± 6.7; 48-h hatching rates: 58.1 ± 9.4, 71.2 ± 9.4, and 62.3 ± 9.4, for HHP, T, and untreated, respectively). Embryos that hatched after warming did not differ in inner cell mass and trophectoderm cell counts (inner cell mass: 15.0 ± 1.9, 12.7 ± 3.0, and 13.0 ± 2.0; trophectoderm: 133.6 ± 8.4, 137.3 ± 12.8, and 138.4 ± 8.6 for HHP, T, and untreated groups, respectively; P > 0.05). Complementary studies are needed to analyze the effects of a sublethal stress in bovine oocytes on the subsequent embryo production and quality. Species-specific mechanisms could underlie the differences in results obtained in bovine and porcine. RTA2011-00090 (FEDER-INIA). Muñoz, Trigal, and Correia are sponsored by RYC08-03454, Cajastur, and FPU2009-5265, respectively.

scholarly journals Nicotinamide Supplementation during the In Vitro Maturation of Oocytes Improves the Developmental Competence of Preimplantation Embryos: Potential Link to SIRT1/AKT Signaling

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1550 ◽  
Author(s):  
Marwa El Sheikh ◽  
Ahmed Atef Mesalam ◽  
Muhammad Idrees ◽  
Tabinda Sidrat ◽  
Ayman Mesalam ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
In Vitro Maturation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Akt Signaling ◽  
Developmental Competence ◽  
Preimplantation Embryos ◽  
Vitamin B3 ◽  
Cell Stage

Nicotinamide (NAM), the amide form of vitamin B3, plays pivotal roles in regulating various cellular processes including energy production and maintenance of genomic stability. The current study aimed at deciphering the effect of NAM, when administered during in vitro maturation (IVM), on the developmental competence of bovine preimplantation embryos. Our results showed that low NAM concentrations reduced the oxidative stress and improved mitochondrial profile, total cleavage and 8–16 cell stage embryo development whereas the opposite profile was observed upon exposure to high NAM concentrations (10 mM onward). Remarkably, the hatching rates of day-7 and day-8 blastocysts were significantly improved under 0.1 mM NAM treatment. Using RT-qPCR and immunofluorescence, the autophagy-related (Beclin-1 (BECN1), LC3B, and ATG5) and the apoptotic (Caspases; CASP3 and 9) markers were upregulated in oocytes exposed to high NAM concentration (40 mM), whereas only CASP3 was affected, downregulated, following 0.1 mM treatment. Additionally, the number of cells per blastocyst and the levels of SIRT1, PI3K, AKT, and mTOR were higher, while the inner cell mass-specific transcription factors GATA6, SOX2, and OCT4 were more abundant, in day-8 embryos of NAM-treated group. Taken together, to our knowledge, this is the first study reporting that administration of low NAM concentrations during IVM can ameliorate the developmental competence of embryos through the potential regulation of oxidative stress, apoptosis, and SIRT1/AKT signaling.

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