Short-term diet intervention comprising of olive oil, vitamin D, and omega-3 fatty acids alters the small non-coding RNA (sncRNA) landscape of human sperm.

Offspring health outcomes are often linked with epigenetic alterations triggered by maternal nutrition and intrauterine environment. Strong experimental data also link paternal preconception nutrition with pathophysiology in the offspring, but the mechanism(s) routing effects of paternal exposures remain elusive. Animal experimental models have highlighted small non-coding RNAs (sncRNAs) as potential regulators of paternal effects.

Incubator type affects human blastocyst formation and embryo metabolism: a randomized controlled trial.

Study Question: Does the type of incubator used to culture human preimplantation embryos affect development to the blastocyst stage and alter amino acid utilization of embryos in assisted reproduction?

Summary Answer: Culturing embryos in a time lapse system (TLS) was associated with a higher Day 5 blastocyst formation rate and altered amino acid utilization when measured from Day 3 to Day 5 compared to the standard benchtop incubator.

What Is Known Already: Culture environment is known to be important for the developing preimplantation embryo. TLSs provide a stable milieu allowing embryos to be monitored in situ, whereas embryos cultured in standard benchtop incubators experience environmental fluctuations when removed for morphological assessment.

A scaffold-free approach to cartilage tissue generation using human embryonic stem cells.

Articular cartilage functions as a shock absorber and facilitates the free movement of joints. Currently, there are no therapeutic drugs that promote the healing of damaged articular cartilage. Limitations associated with the two clinically relevant cell populations, human articular chondrocytes and mesenchymal stem cells, necessitate finding an alternative cell source for cartilage repair.

Maternal intermittent fasting during pregnancy induces fetal growth restriction and down-regulated placental system A amino acid transport in the rat.

During Ramadan, many pregnant Muslim women fast between dawn and sunset. Although the impacts of prolonged maternal intermittent fasting (IF) on fetal growth and placental function are under-researched, reported effects include reduced placental weight and birth weight. In the present study, pregnant Wistar rats were used to model repeated cycles of IF on fetal development and placental function and to examine sex-specific effects.

HYPOXIA AND REPRODUCTIVE HEALTH: Hypoxic regulation of preimplantation embryos: lessons from human embryonic stem cells.

Development of the preimplantation embryo is reliant on nutrients present in the milieu of the reproductive tract. While carbohydrates, amino acids, lipids, and micronutrients are often considered when discussing preimplantation embryo nutrition, environmental oxygen is frequently overlooked. Although oxygen is not classically considered a nutrient, it is an important component of the in vitro culture environment and a critical regulator of cellular physiology.

The Fatty Acid Composition of Human Follicular Fluid Is Altered by a 6-Week Dietary Intervention That Includes Marine Omega-3 Fatty Acids.

The fatty acid composition of human follicular fluid is important for oocyte development and for pregnancy following in vitro fertilization (IVF). This study investigated whether a dietary intervention that included an increase in marine omega-3 fatty acids, olive oil and vitamin D alters the fatty acid composition of human follicular fluid. The association of lifestyle factors with follicular fluid fatty acid composition was also investigated.

Effect of a 6-week "Mediterranean" dietary intervention on in vitro human embryo development: the Preconception Dietary Supplements in Assisted Reproduction double-blinded randomized controlled trial.

Objective: To study the impact of increased dietary intake of omega-3 fatty acids, vitamin D, and olive oil for 6 weeks before in vitro fertilization (IVF) or IVF-intracytoplasmic sperm injection (ICSI) on morphokinetic markers of early embryo development.

Design: A double-blinded randomized controlled trial.

Setting: Academic IVF unit.

Glycolysis Regulates Human Embryonic Stem Cell Self-Renewal under Hypoxia through HIF-2α and the Glycolytic Sensors CTBPs.

Glycolysis and hypoxia are key regulators of human embryonic stem cell (hESC) self-renewal, but how changes in metabolism affect gene expression is poorly understood. C-terminal binding proteins (CTBPs) are glycolytic sensors that through NADH binding link the metabolic state of the cell to its gene expression, by acting as transcriptional corepressors, or coactivators. However, the role of CTBPs in hESCs has not previously been investigated.

The effects of restricted glycolysis on stem-cell like characteristics of breast cancer cells.

Altered glycolysis is a characteristic of many cancers, and can also be associated with changes in stem cell-like cancer (SCLC) cell populations. We therefore set out to directly examine the effect of glycolysis on SCLC cell phenotype, using a model where glycolysis is stably reduced by adapting the cells to a sugar source other than glucose. Restricting glycolysis using this approach consistently resulted in cells with increased oncogenic potential; including an increase in SCLC cells, proliferation in 3D matrigel, invasiveness, chemoresistance, and altered global gene expression.

Augmentation of musculoskeletal regeneration: role for pluripotent stem cells.

The rise in the incidence of musculoskeletal diseases is attributed to an increasing ageing population. The debilitating effects of musculoskeletal diseases, coupled with a lack of effective therapies, contribute to huge financial strains on healthcare systems. The focus of regenerative medicine has shifted to pluripotent stem cells (PSCs), namely, human embryonic stem cells and human-induced PSCs, due to the limited success of adult stem cell-based interventions.

GLUT3 and PKM2 regulate OCT4 expression and support the hypoxic culture of human embryonic stem cells.

Human embryonic stem cells (hESCs) have the capacity to differentiate into all cell types and thus have great potential for regenerative medicine. hESCs cultured at low oxygen tensions are more pluripotent and display an increased glycolytic rate but how this is regulated is unknown. This study therefore aimed to investigate the regulation of glucose metabolism in hESCs and whether this might impact OCT4 expression.

AMPK Activation via Modulation of De Novo Purine Biosynthesis with an Inhibitor of ATIC Homodimerization.

5-Aminoimidazole-4-carboxamide ribonucleotide (known as ZMP) is a metabolite produced in de novo purine biosynthesis and histidine biosynthesis, but only utilized in the cell by a homodimeric bifunctional enzyme (called ATIC) that catalyzes the last two steps of de novo purine biosynthesis. ZMP is known to act as an allosteric activator of the cellular energy sensor adenosine monophosphate-activated protein kinase (AMPK), when exogenously administered as the corresponding cell-permeable ribonucleoside. Here, we demonstrate that endogenous ZMP, produced by the aforementioned metabolic pathways, is also capable of activating AMPK.

Amino acid composition of human uterine fluid: association with age, lifestyle and gynaecological pathology.

Study Question: Do the amino acid levels of human uterine fluid vary with age, BMI, phase of menstrual cycle, benign pathology or diet?

Summary Answer: The levels of 18 amino acids in human uterine fluid were shown to be affected only by maternal diet.

What Is Known Already: Murine, bovine and ovine uterine amino acid content has been reported, but no reliable data on the human exist. Murine studies have demonstrated that the intrauterine periconceptional nutritional environment is affected by maternal diet.

A randomised controlled trial of a preconceptional dietary intervention in women undergoing IVF treatment (PREPARE trial).

Background: In vitro fertilisation (IVF) treatment provides an opportunity to study early developmental responses to periconceptional dietary interventions. Retrospective studies have suggested links between preconception diet and fertility, and more recently, a "Mediterranean" diet has been reported to increase pregnancy rates by up to 40%. In addition, a prospective study examining increased intake of omega-3 polyunsaturated fats demonstrated a quickened rate of embryo development after IVF.

HIF-2α regulates NANOG expression in human embryonic stem cells following hypoxia and reoxygenation through the interaction with an Oct-Sox cis regulatory element.

Low O2 tension is beneficial for human embryonic stem cell (hESC) maintenance but the mechanism of regulation is unknown. HIF-2α was found to bind directly to predicted hypoxic response elements (HREs) in the proximal promoter of OCT4, NANOG and SOX2 only in hESCs cultured under hypoxia (5% O2). This binding induced an array of histone modifications associated with gene transcription while a heterochromatic state existed at atmospheric O2.

Effect of oxygen tension on the amino acid utilisation of human embryonic stem cells.

Background/aims: Human embryonic stem cells (hESCs) are a potential source of cells for treatment of many degenerative diseases, but in culture have a propensity to spontaneously differentiate, possibly due to suboptimal conditions. Culture at low oxygen tensions improves hESC maintenance and regulates carbohydrate metabolism. Hence, a greater understanding of the nutrient requirements of hESCs will allow production of more appropriate culture media.

Reprogramming of two somatic nuclei in the same ooplasm leads to pluripotent embryonic stem cells.

The conversion of the nuclear program of a somatic cell from a differentiated to an undifferentiated state can be accomplished by transplanting its nucleus to an enucleated oocyte (somatic cell nuclear transfer [SCNT]) in a process termed "reprogramming." This process achieves pluripotency and occasionally also totipotency. Exploiting the obstacle of tetraploidy to full development in mammals, we show that mouse ooplasts transplanted with two somatic nuclei simultaneously (double SCNT) support preimplantation development and derivation of novel tetraploid SCNT embryonic stem cells (tNT-ESCs).

Environmental oxygen tension regulates the energy metabolism and self-renewal of human embryonic stem cells.

Energy metabolism is intrinsic to cell viability but surprisingly has been little studied in human embryonic stem cells (hESCs). The current study aims to investigate the effect of environmental O2 tension on carbohydrate utilisation of hESCs. Highly pluripotent hESCs cultured at 5% O2 consumed significantly more glucose, less pyruvate and produced more lactate compared to those maintained at 20% O2.

Media composition: amino acids and cellular homeostasis.

Amino acids are beneficial for the developing preimplantation embryo and therefore form an important component of culture media. This chapter will critically review the importance of amino acids for preimplantation embryos and the impact of this research for the development of sequential culture media used in many assisted conception units. The advantages of culturing embryos in a full complement of amino acids, at close to physiological concentrations will be considered.

Nuclear reprogramming: kinetics of cell cycle and metabolic progression as determinants of success.

Establishment of totipotency after somatic cell nuclear transfer (NT) requires not only reprogramming of gene expression, but also conversion of the cell cycle from quiescence to the precisely timed sequence of embryonic cleavage. Inadequate adaptation of the somatic nucleus to the embryonic cell cycle regime may lay the foundation for NT embryo failure and their reported lower cell counts. We combined bright field and fluorescence imaging of histone H(2b)-GFP expressing mouse embryos, to record cell divisions up to the blastocyst stage.

Association between amino acid turnover and chromosome aneuploidy during human preimplantation embryo development in vitro.

This study investigated the relationship between human preimplantation embryo metabolism and aneuploidy rates during development in vitro. One hundred and eighty-eight fresh and cryopreserved embryos from 59 patients (33.9 +/- 0.

Hypoxia inducible factors regulate pluripotency and proliferation in human embryonic stem cells cultured at reduced oxygen tensions.

Human embryonic stem (hES) cells are routinely cultured under atmospheric, 20% oxygen tensions but are derived from embryos which reside in a 3-5% oxygen (hypoxic) environment. Maintenance of oxygen homeostasis is critical to ensure sufficient levels for oxygen-dependent processes. This study investigates the importance of specific hypoxia inducible factors (HIFs) in regulating the hypoxic responses of hES cells.

Derivation of a novel undifferentiated human foetal phenotype in serum-free cultures with BMP-2.

Skeletal stem and progenitor populations provide a platform for cell-based tissue regeneration strategies. Optimized conditions for ex vivo expansion will be critical and use of serum-free culture may allow enhanced modelling of differentiation potential. Maintenance of human foetal femur-derived cells in a chemically defined medium (CDM) with activin A and fibroblast growth factor-2 generated a unique undifferentiated cell population in comparison to basal cultures, with significantly reduced amino acid depletion, appearance and turnover, reduced alkaline phosphatase (ALP) activity and loss of type I and II collagen expression demonstrated by fluorescence immunocytochemistry.

Human embryos developing in vitro are susceptible to impaired epithelial junction biogenesis correlating with abnormal metabolic activity.

Background: Blastocyst biogenesis occurs over several cell cycles during the preimplantation period comprising the gradual expression and membrane assembly of junctional protein complexes which distinguish the outer epithelial trophectoderm (TE) cells from the inner cell mass (ICM). In the human, TE integrity and the formation of a junctional seal can often be impaired. Embryos likely to result in a successful pregnancy after transfer are mostly selected according to morphological criteria.

Metabolism of human embryos following cryopreservation: implications for the safety and selection of embryos for transfer in clinical IVF.

Background: Cryopreservation of supernumerary embryos is routinely performed in human-assisted reproduction, providing a source of embryos which can be thawed for use in subsequent treatment cycles. However, the viability of cryopreserved embryos has traditionally relied on morphological assessment, which is a poor predictor of embryo health since freezing leads to a significant overall reduction in implantation potential, and its long-term efficacy is unknown. This study describes how the post-thaw metabolism of human embryos can be used to predict future development to the blastocyst stage.