Visualization of 3-Dimensional Vectors in a Dynamic Embryonic System—WormGUIDES

WormGUIDES is an open-source dynamic embryonic system designed to facilitate global understanding of cellular decisions in the developing nervous system of the nematode C. elegans. WormGUIDES was designed to allow investigation and exploration of the observational results of the C. elegans life cycle from laboratory experiments. In the process of a mechanistic C. elegans model development, some functionalities of WormGUIDES needed to be enhanced to support model validation and verification. In this study, a new way to visualize 3-dimentional vectors within WormGUIDES was investigated and presented. Then, the practical values of this method were demonstrated by visualizing two biologically significant directions (i.e., division orientation and cell polarity) of individual embryonic cells in C. elegans. Lastly, a mathematic approach was designed to illustrate the differences between these two sets of vectors and provide easy indications of the location of these individual cells that have large data discrepancies within the C. elegans embryonic system.

Cardiac differentiation is modulated by anti-apoptotic signals in murine embryonic stem cells

BACKGROUND Embryonic stem cells(ESCs)serve as a crucial ex vivo model,representing epiblast cells derived from the inner cell mass of blastocyst-stage embryos.ESCs exhibit a unique combination of self-renewal potency,unlimited proliferation,and pluripotency.The latter is evident by the ability of the isolated cells to differ-entiate spontaneously into multiple cell lineages,representing the three primary embryonic germ layers.Multiple regulatory networks guide ESCs,directing their self-renewal and lineage-specific differentiation.Apoptosis,or programmed cell death,emerges as a key event involved in sculpting and forming various organs and structures ensuring proper embryonic development.How-ever,the molecular mechanisms underlying the dynamic interplay between diffe-rentiation and apoptosis remain poorly understood.AIM To investigate the regulatory impact of apoptosis on the early differentiation of ESCs into cardiac cells,using mouse ESC(mESC)models-mESC-B-cell lym-phoma 2(BCL-2),mESC-PIM-2,and mESC-metallothionein-1(MET-1)-which overexpress the anti-apoptotic genes Bcl-2,Pim-2,and Met-1,respectively.METHODS mESC-T2(wild-type),mESC-BCL-2,mESC-PIM-2,and mESC-MET-1 have been used to assess the effect of potentiated apoptotic signals on cardiac differentiation.The hanging drop method was adopted to generate embryoid bodies(EBs)and induce terminal differentiation of mESCs.The size of the generated EBs was measured in each condition compared to the wild type.At the functional level,the percentage of cardiac differentiation was measured by calculating the number of beating cardiomyocytes in the manipulated mESCs compared to the control.At the molecular level,quantitative reverse transcription-polymerase chain reaction was used to assess the mRNA expression of three cardiac markers:Troponin T,GATA4,and NKX2.5.Additionally,troponin T protein expression was evaluated through immunofluorescence and western blot assays.RESULTS Our findings showed that the upregulation of Bcl-2,Pim-2,and Met-1 genes led to a reduction in the size of the EBs derived from the manipulated mESCs,in comparison with their wild-type counterpart.Additionally,a decrease in the count of beating cardiomyocytes among differentiated cells was observed.Furthermore,the mRNA expression of three cardiac markers-troponin T,GATA4,and NKX2.5-was diminished in mESCs overexpressing the three anti-apoptotic genes compared to the control cell line.Moreover,the overexpression of the anti-apoptotic genes resulted in a reduction in troponin T protein expression.CONCLUSION Our findings revealed that the upregulation of Bcl-2,Pim-2,and Met-1 genes altered cardiac differentiation,providing insight into the intricate interplay between apoptosis and ESC fate determination.

Early embryonic failure caused by a novel mutation in the TUBB8 gene:A case report

BACKGROUND This study aimed to explore the relationship between gene mutations and early embryonic development arrest and to provide more possibilities for the diagnosis and treatment of repeated implantation failure.CASE SUMMARY Here,we collected and described the clinical data of a patient with early embryonic development stagnation after repeated in vitro fertilization attempts for primary infertility at the Department Reproductive Center of Zaozhuang Maternal and Child Healthcare Hospital.We also detected the whole-exon gene of the patient's spouse and parents,and conducted bioinformatics analysis to determine the pathogenesis of the gene.CONCLUSION A novel mutant of the TUBB8 gene[c.602G>T(p.C201F)]was identified,and this mutant provided new data on the genotype-phenotype relationships of related diseases.

Gap junction gene innexin3 being highly expressed in the nervous system and embryonic stage of the mud crab Scylla paramamosain

Innexin proteins are a class of transmembrane proteins existing in invertebrates and they have diverse biological functions. The innexin protein Sp-inx2 has been demonstrated to play roles in immune response and promotion of cell apoptosis in the mud crab Scylla paramamosain . One novel innexin gene, named as Sp-inx3 was characterized from S. paramamosin in this study, with an open reading frame of 1 101 bp encoding 367 amino acid residues. Multiple sequence alignment revealed that the Sp-inx3 is highly homologous with innexin3 of Cancer boredis and Homorus americanus . Quantitative real-time PCR (qPCR) and the western blotting results revealed that Sp-inx3 gene was expressed predominantly in the eyestalk, brain, and thoracic ganglion mass in both female and male crabs. The immunohistochemistry assay (IHC) also showed the widespread and intense immunoreactivity of Sp-inx3 in the brain and thoracic ganglion mass. Sp-inx3 mRNA transcription profi les exhibited signifi cantly higher expression from the embryo1 to embryo4 period and low level of expression at the prehatching period and zoea I larva period of S . paramamosain . These results indicate that the Sp-inx3 may play an important role in the nervous system and early embryonic development of S . paramamosain.

Simplified three-dimensional culture system for long-term expansion of embryonic stem cells

AIM: To devise a simplified and efficient method for long-term culture and maintenance of embryonic stem cells requiring less frequent passaging. METHODS: Mouse embryonic stem cells(ESCs) labeled with enhanced yellow fluorescent protein were cultured in three-dimensional(3-D) self-assembling scaffolds and compared with traditional two-dimentional(2-D) culture techniques requiring mouse embryonic fibroblast feeder layers or leukemia inhibitory factor. 3-D scaffolds encapsulating ESCs were prepared by mixing ESCs with polyethylene glycol tetra-acrylate(PEG-4-Acr) and thiolfunctionalized dextran(Dex-SH). Distribution of ESCs in 3-D was monitored by confocal microscopy. Viability and proliferation of encapsulated cells during long-term culture were determined by propidium iodide as well as direct cell counts and PrestoB lue(PB) assays. Genetic expression of pluripotency markers(Oct4, Nanog, Klf4, and Sox2) in ESCs grown under 2-D and 3-D cultureconditions was examined by quantitative real-time polymerase chain reaction. Protein expression of selected stemness markers was determined by two different methods, immunofluorescence staining(Oct4 and Nanog) and western blot analysis(Oct4, Nanog, and Klf4). Pluripotency of 3-D scaffold grown ESCs was analyzed by in vivo teratoma assay and in vitro differentiation via embryoid bodies into cells of all three germ layers. RESULTS: Self-assembling scaffolds encapsulating ESCs for 3-D culture without the loss of cell viability were prepared by mixing PEG-4-Acr and Dex-SH(1:1 v/v) to a final concentration of 5%(w/v). Scaffold integrity was dependent on the degree of thiol substitution of Dex-SH and cell concentration. Scaffolds prepared using Dex-SH with 7.5% and 33% thiol substitution and incubated in culture medium maintained their integrity for 11 and 13 d without cells and 22 ± 5 d and 37 ± 5 d with cells, respectively. ESCs formed compact colonies, which progressively increased in size over time due to cell proliferation as determined by confocal microscopy and PB staining. 3-D scaffold cultured ESCs expressed significantly higher levels(P < 0.01) of Oct4, Nanog, and Kl4, showing a 2.8, 3.0 and 1.8 fold increase, respectively, in comparison to 2-D grown cells. A similar increase in the protein expression levels of Oct4, Nanog, and Klf4 was observed in 3-D grown ESCs. However, when 3-D cultured ESCs were subsequently passaged in 2-D culture conditions, the level of these pluripotent markers was reduced to normal levels. 3-D grown ESCs produced teratomas and yielded cells of all three germ layers, expressing brachyury(mesoderm), NCAM(ectoderm), and GATA4(endoderm) markers. Furthermore, these cells differentiated into osteogenic, chondrogenic, myogenic, and neural lineages expressing Col1, Col2, Myog, and Nestin, respectively. CONCLUSION: This novel 3-D culture system demonstrated long-term maintenance of mouse ESCs without the routine passaging and manipulation necessary for traditional 2-D cell propagation.

Generation of genetically modified mice using CRISPR/Cas9 and haploid embryonic stem cell systems

With the development of high-throughput sequencing technology in the post-genomic era, researchers have concentrated their efforts on elucidating the relationships between genes and their corresponding functions. Recently, important progress has been achieved in the generation of genetically modified mice based on CRISPR/Cas9 and haploid embryonic stem cell （haESC） approaches, which provide new platforms for gene function analysis, human disease modeling, and gene therapy. Here, we review the CRISPR/Cas9 and haESC technology for the generation of genetically modified mice and discuss the key challenges in the application of these approaches.

Maternal zinc alleviates tert-butyl hydroperoxide-induced mitochondrial oxidative stress on embryonic development involving the activation of Nrf2/PGC-1αpathway

Background Mitochondrial dysfunction induced by excessive mitochondrial reactive oxygen species(ROS)damages embryonic development and leads to growth arrest.Objective The purpose of this study is to elucidate whether maternal zinc(Zn)exert protective effect on oxidative stress targeting mitochondrial function using an avian model.Result In ovo injected tert-butyl hydroperoxide(BHP)increases(P<0.05)hepatic mitochondrial ROS,malondialdehyde(MDA)and 8-hydroxy-2-deoxyguanosine(8-OHdG),and decreases(P<0.05)mitochondrial membrane potential(MMP),mitochondrial DNA(mtDNA)copy number and adenosine triphosphate(ATP)content,contributing to mitochondrial dysfunction.In vivo and in vitro studies revealed that Zn addition enhances(P<0.05)ATP synthesis and metallothionein 4(MT4)content and expression as well as alleviates(P<0.05)the BHP-induced mitochondrial ROS generation,oxidative damage and dysfunction,exerting a protective effect on mitochondrial function by enhancing antioxidant capacity and upregulating the mRNA and protein expressions of Nrf2 and PGC-1α.Conclusions The present study provides a new way to protect offspring against oxidative damage by maternal Zn supplementation through the process of targeting mitochondria involving the activation of Nrf2/PGC-1αsignaling.

MicroRNA-146a Promotes Embryonic Stem Cell Differentiation towards Vascular Smooth Muscle Cells through Regulation of Kruppel-like Factor 4

Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs.

Recovery of nigrostriatal dopaminergic system insufficiency by allotransplantation of embryonic brain tissue

In an experiment in rats with electrolytic lesion of the compact part of substantia nigra (SN) and after allotransplantation of the embryonic tissue of SN in the caudate nucleus the features of movement and emotional behavior in the Open Field Test (OFT), the rotation movements caused by an administration of amphetamine, a content of catecholamines in the caudate nucleus, hypothalamus and blood plasma have been investigated. It is shown that the electrolytic lesion causes violations of the statokinetic reflexes, the horizontal and the vertical movement activity, enhances the rotatory behavior, slow the orienttate-searching and the emotional reactions that combined with disbalance in dopamine-and noradrenalinetransmitter systems functioning. Allotransplantation of the embryonic dofaminsynthesizing brain tissue contributes to the restoration of movement activeity and its specific neurotransmitter ensuring.

Effects of LPA on the development of sheep in vitro fertilized embryos and attempt to establish sheep embryonic stem cells

Lysophosphatidic acid(LPA)is a small molecule glycerophospholipid,which regulates multiple downstream signalling pathways through G-protein-coupled receptors to achieve numerous functions on oocyte maturation and embryo development.In this study,sheep in vitro fertilized embryos were applied to investigate the effects of LPA on early embryos development and embryonic stem cell establishment.At first,the maturation medium containing estrus female sheep serum and synthetic oviduct fluid(SOF)were optimized for sheep IVF,and then the effects of LPA were investigated.From 0.1 to 10μmol L^(–1),LPA had no significant effect on the cleavage rate(P>0.05),but the maturation rate and blastocyst rate increased dependently with LPA concentration(P<0.05),and the blastocyst morphology was normal.When the LPA concentration was 15μmol L^(–1),the maturation rate,cleavage rate and blastocyst rate decreased significantly(P<0.05),and the blastocyst exhibited abnormal morphology and could not develop into highquality blastocyst.Besides,the exogenous LPA increases the expression of LPAR2,LPAR4,TE-related gene CDX-2and pluripotency-related gene OCT-4 in sheep early IVF embryos with the raise of LPA concentration from 0.1 to 10μmol L^(–1).The expression of LPAR2,LPAR4,CDX-2 and OCT-4 from the LPA-0.1μmol L^(–1)to LPA-10μmol L^(–1)groups in early embryos were extremely significant(P<0.05),while the expression of these genes significantly decreased in 15μmol L^(–1)LPA-treated embryos compared with LPA-10μmol L^(–1)group(P<0.05).The inner cell mass in 15μmol L^(–1)LPA-treated embryos was also disturbed,and the blastocysts formation was abnormal.Secondly,the sheep IVF blastocysts were applied to establish embryonic stem cells.The results showed that LPA made the blastocyst inoculated cells grow towards TSC-like cells.They enhanced the fluorescence intensity and mRNA abundance of OCT-4 and CDX-2 as the concentration increased from 0 to 10μmol L^(–1),while 15μmol L^(–1)LPA decreased OCT-4 and CDX-2 expression in the derived cells.The expression of CDX-2 and OCT-4 in the blastocyst inoculated cells of LPA-1μmol L^(–1)group and LPA-10μmol L^(–1)group extremely significantly increased(P<0.05),but there was significant decrease in LPA-15μmol L^(–1)group compared with LPA-10μmol L^(–1)group(P<0.05).Meanwhile,the protein expression of LPAR2 and LPAR4 remarkably increased after treatment of LPA at 10μmol L^(–1)concentration.This study references the IVF embryo production and embryonic stem cell research of domestic animals.

Effects of dietary coenzyme Q10 supplementation during gestation on the embryonic survival and reproductive performance of high‑parity sows

Background Fertility declines in high-parity sows.This study investigated whether parity-dependent declines in embryonic survival and reproductive performance could be restored by dietary coenzyme Q10(CoQ10)supplementation.Methods Two experiments were performed.In Exp.1,30 young sows that had completed their 2nd parity and 30 high-parity sows that had completed their 10^(th)parity,were fed either a control diet(CON)or a CON diet supple-mented with 1 g/kg CoQ10(+CoQ10)from mating until slaughter at day 28 of gestation.In Exp.2,a total of 314 post-weaning sows with two to nine parities were fed the CON or+CoQ10 diets from mating throughout gestation.Results In Exp.1,both young and high-parity sows had a similar number of corpora lutea,but high-parity sows had lower plasma CoQ10 concentrations,down-regulated genes involved with de novo CoQ10 synthesis in the endome-trium tissues,and greater levels of oxidative stress markers in plasma and endometrium tissues.High-parity sows had fewer total embryos and alive embryos,lower embryonic survival,and greater embryo mortality than young sows.Dietary CoQ10 supplementation increased the number of live embryos and the embryonic survival rate to levels simi-lar to those of young sows,as well as lowering the levels of oxidative stress markers.In Exp.2,sows showed a parity-dependent decline in plasma CoQ10 levels,and sows with more than four parities showed a progressive decline in the number of total births,live births,and piglets born effective.Dietary supplementation with CoQ10 increased the number of total births,live births,and born effective,and decreased the intra-litter covariation coefficients and the percentage of sows requiring farrowing assistance during parturition.Conclusions Dietary CoQ10 supplementation can improve the embryonic survival and reproductive performance of gestating sows with high parity,probably by improving the development of uterine function.

Whole‑genome transcriptome and DNA methylation dynamics of pre‑implantation embryos reveal progression of embryonic genome activation in buffaloes

Background During mammalian pre-implantation embryonic development(PED),the process of maternal-to-zygote transition(MZT)is well orchestrated by epigenetic modification and gene sequential expression,and it is related to the embryonic genome activation(EGA).During MZT,the embryos are sensitive to the environment and easy to arrest at this stage in vitro.However,the timing and regulation mechanism of EGA in buffaloes remain obscure.Results Buffalo pre-implantation embryos were subjected to trace cell based RNA-seq and whole-genome bisulfite sequencing(WGBS)to draw landscapes of transcription and DNA-methylation.Four typical developmental steps were classified during buffalo PED.Buffalo major EGA was identified at the 16-cell stage by the comprehensive analy-sis of gene expression and DNA methylation dynamics.By weighted gene co-expression network analysis,stage-spe-cific modules were identified during buffalo maternal-to-zygotic transition,and key signaling pathways and biological process events were further revealed.Programmed and continuous activation of these pathways was necessary for success of buffalo EGA.In addition,the hub gene,CDK1,was identified to play a critical role in buffalo EGA.Conclusions Our study provides a landscape of transcription and DNA methylation in buffalo PED and reveals deeply the molecular mechanism of the buffalo EGA and genetic programming during buffalo MZT.It will lay a foundation for improving the in vitro development of buffalo embryos.

Embryonic, genetic and clinical outcomes of fresh versus vitrified oocyte: A retrospective cohort study

Objective:To compare embryonic development,ploidy status and clinical outcomes between fresh and frozen-thawed oocytes.Methods:This retrospective cohort study evaluated 83 fertilization cycles including both fresh and frozen oocytes from 79 patients at the HP Fertility Center of Hai Phong International Hospital of Obstetrics and Pediatrics in Vietnam.The patient underwent several ovarian stimulation cycles to accumulate a certain number of oocytes that would be vitrified.In the last oocyte retrieval,all patient’s oocytes including both frozen and fresh would be fertilized.The outcomes included the rates of oocyte survival,cleavage embryo,blastocyst,ploidy status,pregnancy,biochemical pregnancy and clinical pregnancy.Results:The oocyte survival rate after thawing was 96.5%.No statistically significant difference was found when comparing fresh and frozen oocytes regarding fertilization rate(78.1%vs.75.5%,P=0.461),usable cleavage embryo rate(86.9%vs.87.2%,P=0.916)but usable blastocyst rate was found higher statistically in the frozen oocyte group(44.4%vs.54.0%,P=0.049).The percentages of euploid,aneuploid and mosaic embryos between the fresh group and the vitrified group had no significant differences(33.8%vs.31.6%,P=0.682;51.0%vs.54.2%,P=0.569;15.2%vs.12.4%,P=0.787;respectively).The rates of pregnancy,biochemical pregnancy and clinical pregnancy had no statistical difference(68.8%vs.64.8%,P=0.764;12.5%vs.3.6%,P=0.258;37.5%vs.46.4%,P=0.565).17 Mature oocytes are the minimum to have at least one euploid embryo.Conclusions:Oocyte vitrification does not affect embryonic,genetic and clinical results.The number of mature oocytes should be considered for fertilization in some cases.

Embryonic Development and Eclosion Season of New Species Berastagia (Lepidoptera: Pyralidae) from Taiwan

This paper describes a new species of the snout moth Berastagia tainanica sp. nov. (Lepidoptera: Pyralidae) from Taiwan. From 2009 to 2016, a biology study was conducted on population dynamics and embryonic development. Spring season is the peak of the eclosion of overwintering larvae or pupae. The average longevity of adult was 14.8 ± 6.2 days (N = 174), the average number of eggs laid was 259 ± 3 eggs/moth (N = 2), the hatching rate of eggs was 95.4% (N = 262), and the average hatching time of eggs was 99.6 ± 18.6 hours (N = 68). The average body length of males was 5.64 mm ± 0.91 mm (N = 30), and the average body length of females was 6.28 mm ± 0.84 mm (N = 30). This finding indicates that female snout moths are larger than males (Global R = 0.058, P = 0.012). The snout moth eclosion rate was 16.9 moths/100 pods in the first year (2010/2011, N = 2,224 pods) and 10.9 moths/100 pods in the second year (2014/2015, N = 6,382 pods). The pod borer rate was 31.8% (N = 707) and the seed borer rate was 41.2% (N = 3,628) in the first year, whereas the pod borer rate was 76.2% (N = 6,382) in the second year.

Visible Light and Its Influence on the Embryonic Viability of the Cricket Acheta domesticus

During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.

Clinical Analysis of Embryonic Posterior Cerebral Artery

Objective:To understand the clinical characteristics of patients with embryonic posterior cerebral artery and its correlation with abnormal vascular development.Methods:The clinical data of 396 patients with embryonic posterior cerebral artery confirmed by magnetic resonance angiography(MRA)and computed tomography angiography(CTA)were analyzed.Results:Two-hundred patients had clinical manifestations of posterior circulation ischemia,including recurrent dizziness,vertigo,and tinnitus;45 had headaches,97 had limb weakness,and 16 patients had syncope or impaired consciousness.Seventy-six patients with circulatory infarction were admitted to the hospital.There were 251 patients with history of hypertension,74 with diabetes,113 with hyperlipidemia,13 with dominant vertebral artery,10 with intracranial aneurysm,and 19 with absence of A1 segment of the anterior cerebral artery(considering developmental variation).Conclusion:Embryonic posterior cerebral artery develops abnormally during the embryonic period,often accompanied by abnormal vascular access.Due to abnormal hemodynamics,the incidence of posterior circulation ischemia,aneurysm,and infarction increases in such patients.

Endometrial Status and Embryonic Implantation about 150 Cases at the Medically Assisted Procreation Laboratory “Le Diafounou”

Background: The endometrium is the tissue that lines the inside of the uterus. It undergoes multiple changes during the menstrual cycle and prepares to welcome the fertilized egg. Endovaginal ultrasound is a first-line examination in the assessment of female infertility. Objective: We aimed to determine the impact of endometrial status by endovaginal ultrasound on the outcome of embryo transfers. Subjects and Methods: This was a prospective cross-sectional study of 150 women collected between January and October 2020 at the “Le Diafounou” medically assisted procreation laboratory. Were included in the study, women presenting for desire of pregnancy and having continued the treatment until the transfer of fresh or frozen embryos. An uterine score was used. This score took into account the thickness of endometrium, it is coffee bean aspect, the presence of the notch, the echogenicity of the endometrium, the pulsatility index, the presence of the flow at the end of diastole and sub-endometrial flow. Ultrasounds were performed using a General Electric logic 500, logic 9 and Voluson E8 device. The data was entered into Excel and then analyzed using SPSS version 21. Results: 150 women were selected for the study. 83 women or 55.3% were between 17 and 35 years old and 44.7% were over 35 years old with an upper limit of 50 years old. The number of women who became pregnant was 69% or 46%. The average thickness of the endometrium was 11.40 mm with extremes of 4.65 mm and 18.6 mm. There was a correlation between the thickness of the endometrium and obtaining a pregnancy (p i.e. 88.7%. The pulsatility index was relatively low for those who started a pregnancy, i.e. 90%. The high pulsatility index is one of the reasons for the failure of embryo implantation. The correlation was significant (p = 0.009). 141 women had no notch in the uterine arteries, i.e. 94%. 94 women or 62.7% had a triple line endometrium or typical coffee bean appearance. End-diastolic flow was observed in 127 women, i.e. 84.7%. The sub-endometrial flow was found in 128 women or 85.3%. Conclusion: The Knowledge of the status of the endometrium is essential and has an impact on the outcome of embryo transfers. The thinner (7 and <15). Doppler factors also play an important role.

The combined application of stem cells and three-dimensional bioprinting scaffolds for the repair of spinal cord injury

Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.

In vitro culture and differentiation of rat embryonic midbrain-derived neural stem cells

BACKGROUND： Midbrain-derived neural stem cells （mNSCs） can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson＇s disease. OBJECTIVE： To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING： An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital （China） from March to November 2007. MATERIALS： Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein （GFAP） antibody and cyclic nucleotide 3＇-phosphohydrolase （CNPase） antibody were provided by Abcam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor （EGF） and fibroblast growth factor-2 （FGF2） were provided by R＆D Systems. METHODS： The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/FI 2, 1% N： supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10ug/mL polylysine and induced to differentiate in the DMEM/F12 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES： The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for β Ⅲ tubulin, GFAP and CNPase. RESULTS： Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tubulin. CONCLUSION： Embryonic day 14 rat mNSCs can differentiate into neuron-like cells and glial cells following induction by EGF, FGF2 and N： additive.

Neural differentiation from embryonic stem cells in vitro : An overview of the signaling pathways

Neurons derived from embryonic stem cells(ESCs) have gained great merit in both basic research and regenerative medicine. Here we review and summarize the signaling pathways that have been reported to be involved in the neuronal differentiation of ESCs,particularly those associated with in vitro differentiation. The inducers and pathways explored include retinoic acid, Wnt/b-catenin, transforming growth factor/bone morphogenetic protein, Notch, fibroblast growth factor, cytokine, Hedgehog, c-Jun N-terminal kinase/mitogen-activated protein kinase and others. Some other miscellaneous molecular factors that have been reported in the literature are also summarized and discussed. These include calcium, calcium receptor, calcineurin, estrogen receptor, Hox protein, ceramide, glycosaminioglycan, ginsenoside Rg1, opioids, two pore channel 2, nitric oxide, chemically defined medium, cellcell interactions, and physical stimuli. The interaction or crosstalk between these signaling pathways and factors will be explored. Elucidating these signals in detail should make a significant contribution to future progress in stem cell biology and allow, for example, better comparisons to be made between differentiation in vivo and in vitro. Of equal importance, a comprehensive understanding of the pathways that are involved in the development of neurons from ESCs in vitro will also accelerate their application as part of translational medicine.