David Gardner

David Gardner
University of Melbourne | MSD · School of BioSciences

About

438
Publications
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Introduction
Skills and Expertise

Publications

Publications (438)
Article
Full-text available
Background Modern assisted reproductive technology (ART), including pre‐implantation genetic testing for aneuploidy (PGT‐A), has opened new avenues in understanding early embryonic events and has simultaneously raised questions about the impact of ART itself on sex ratios. Aims The primary aim was to investigate whether patient demographic charact...
Article
Full-text available
The blastocyst develops a unique metabolism that facilitates the creation of a specialized microenvironment at the site of implantation characterized by high levels of lactate and reduced pH. While historically perceived as a metabolic waste product, lactate serves as a signaling molecule which facilitates the invasion of surrounding tissues by can...
Article
Full-text available
To assess the value of deep learning in selecting the optimal embryo for in vitro fertilization, a multicenter, randomized, double-blind, noninferiority parallel-group trial was conducted across 14 in vitro fertilization clinics in Australia and Europe. Women under 42 years of age with at least two early-stage blastocysts on day 5 were randomized t...
Chapter
With the demand for cryopreservation of gametes, embryos, and ovarian tissue ever increasing, it is important to maintain research into how such processes can be further optimized. Here, we consider how antioxidants (AOX) and antifreeze proteins (AFP) can play a role in human ART. Specific antioxidants have the capacity to significantly reduce the...
Article
Full-text available
Germline epigenetic programming, including genomic imprinting, substantially influences offspring development. Polycomb Repressive Complex 2 (PRC2) plays an important role in Histone 3 Lysine 27 trimethylation (H3K27me3)-dependent imprinting, loss of which leads to growth and developmental changes in mouse offspring. In this study, we show that off...
Article
In brief A ketogenic diet (KD) elevates blood β-hydroxybutyrate to concentrations that are known to perturb the development, metabolism, histone acetylation and viability of preimplantation mouse embryos in culture. This study shows that a maternal KD changes available nutrient levels in the oviduct, leading to altered embryo development and epigen...
Article
Background Non‐obstructive azoospermia (NOA) diagnosis poses challenges for couples seeking parenthood. Microdissection testicular sperm extraction (MD‐TESE) excels in retrieving testicular sperm cells for NOA cases. However, limited live birth data in Australian NOA patients hinders accurate counselling. Aims This study aimed to determine the lik...
Article
Background and Aims: One of the most skilled procedures performed by embryologists is intracytoplasmic sperm injection (ICSI), which takes significant experience to master. Conducting the procedure requires a high level of concentration with training a significant burden on clinical laboratory efficiency. Advancement of a micro 3D printed device to...
Article
Background and Aims: Data are lacking regarding the optimal time interval between human chorionic gonadotropin (hCG) administration and ovum pick-up (hCG-OPU interval), and its impact on blastocyst euploidy. Our aim was to compare the blastocyst euploidy rate between IVF cycles with hCG-OPU interval of 36 and 37 h. Method: In this historic cohort s...
Article
Full-text available
Intracytoplasmic sperm injection (ICSI) imparts physical stress on the oolemma of the oocyte and remains among the most technically demanding skills to master, with success rates related to experience and expertise. ICSI is also time-consuming and requires workflow management in the laboratory. This study presents a device designed to reduce the pr...
Article
Full-text available
Background: Men diagnosed with Klinefelter syndrome (KS) commonly exhibit non-obstructive azoospermia or rarely having sperm in their ejaculate, rendering them traditionally considered sterile prior to the introduction of intracytoplasmic sperm injection (ICSI). The presence of mosaic KS may mask the classical phenotype, resulting in underdiagnosis...
Article
Research question: Advanced glycation end-products (AGE) are elevated in the uterine environment of obese infertile women. Can the detrimental effects of AGE on endometrial epithelial cells be mitigated with therapeutics, and recapitulated in a more physiologically relevant primary model (organoids)? Design: Human endometrial epithelial cells (E...
Chapter
Selecting the best embryo to transfer to the uterus is key to successful in vitro fertilization (IVF). A huge amount of research has been devoted to this topic and there are numerous methods used, from simple morphological assessment to molecular biological techniques to assess the genome and metabolism of the newly fertilized embryo. For many of t...
Article
Full-text available
Background Non-genetic disease inheritance and offspring phenotype are substantially influenced by germline epigenetic programming, including genomic imprinting. Loss of Polycomb Repressive Complex 2 (PRC2) function in oocytes causes non-genetically inherited effects on offspring, including embryonic growth restriction followed by post-natal offspr...
Article
Over the past four decades our ability to maintain a viable human embryo in vitro has improved dramatically, leading to higher implantation rates. This has led to a notable shift to single blastocyst transfer and the ensuing elimination of high order multiple gestations. Future improvements to embryo culture systems will not only come from new impr...
Article
Full-text available
Background: Cleavage stage multinucleation is a morphological assessment IVF labs may use to rank embryos for transfer, as blastocysts that were multinucleated at the 2-cell or 4-cell stage have a lower live birth rate (LBR) compared to blastocysts that were mononucleated ¹ . However, when these blastocysts are PGT-A tested, the euploidy rate is si...
Article
Full-text available
Background: Diet-induced nutritional changes in the maternal reproductive tract stimulate embryonic adaptations to maintain growth and survival, directly impacting child and adult health via developmental programming. This is plausibly facilitated by an interrelationship between metabolism and epigenetic control of gene expression, termed ‘metabolo...
Article
Full-text available
Background: There has been much debate and concern about whether the dose of exogenous gonadotrophins used for controlled ovarian stimulation (COS) adversely affects the selection of leading follicles and potentially impacts the quality of the eggs retrieved and the embryos created. The ploidy status of the embryo, as assessed by pre-implantation g...
Article
Full-text available
Background: At the time of implantation, the blastocyst produces a significant amount of lactic acid (LA), creating a microenvironment characterized by high lactate and low pH. Historically considered a ‘by-product’ of metabolism, studies have revealed lactate to be a key regulator of cell function, with a lactate-specific receptor, GPR81, recently...
Article
Full-text available
Background: When patients have multiple blastocysts following IVF/ICSI, selection of the most viable blastocyst for transfer can reduce time taken for patients to conceive. An artificial intelligence system, Ivy, has been developed to predict pregnancy from embryo images. Aim: To determine the frequency that Ivy selects the same embryo for transfer...
Article
Full-text available
For 40 years we have relied upon morphological assessment of the human embryo for its selection for transfer. With the advent of time-lapse microscopy (TLM), we have been able examine the timings of key developmental events and create algorithms to further advance embryo selection. However, such algorithms do not utilise all available data. Artific...
Article
Full-text available
Background: Embryo culture and cryopreservation causes detrimental effects on blastocyst gene expression. While combined antioxidants (acetyl-L-carnitine/N-acetyl-L-cysteine/[Formula: see text]-lipoic acid (A3)) in culture and vitrification media have beneficial effects on embryo and fetal development, their impact on fetal gene expression has not...
Preprint
Full-text available
Background Non-genetic disease inheritance and offspring phenotype is substantially influenced by germline epigenetic programming, including genomic imprinting. Loss of Polycomb Repressive Complex 2 (PRC2) function in oocytes causes non-genetically inherited effects on offspring, including embryonic growth restriction followed by post-natal offspri...
Article
Research question : Does the ketone acetoacetate (AcAc) alone, or combined with β-hydroxybutyrate (βOHB), impact mouse embryo development, metabolism, histone acetylation, and viability? Design : Pronucleate mouse oocytes were cultured in vitro in G1/G2 media supplemented with ketones (AcAc or AcAc + βOHB) at concentrations representing maternal s...
Preprint
Full-text available
Germline epigenetic programming, including genomic imprinting, substantially influences offspring development. Polycomb Repressive Complex 2 (PRC2) plays an important role in Histone 3 Lysine 27 trimethylation (H3K27me3)-dependent imprinting, loss of which leads to placental hyperplasia in mammalian offspring generated by somatic cell nuclear trans...
Article
Full-text available
STUDY QUESTION What is the effect of the ketone β-hydroxybutyrate (βOHB) on preimplantation mouse embryo development, metabolism, epigenetics and post-transfer viability? SUMMARY ANSWER In vitro βOHB exposure at ketogenic diet (KD)-relevant serum concentrations significantly impaired preimplantation mouse embryo development, induced aberrant glyco...
Article
Research question : What is the effect of combined antioxidants (acetyl-L-carnitine, N-acetyl-L-cysteine and α-lipoic acid; A3) when used in culture media and vitrification/warming solutions, on mouse fetal gene expression? Design : A laboratory-based analysis of an animal model. Embryo transfers were conducted on in vivo flushed blastocysts, or b...
Article
Research Question Is the blastocyst's idiosyncratic metabolic production of lactate, and subsequent creation of a specialized microenvironment at the implantation site an important mediator of maternal-fetal signaling to promote endometrial receptivity and implantation? Design Hormonally primed ECC-1 and Ishikawa cells were used to assess function...
Article
The aim of this article is to gather 9 thought leaders and their team members to present their ideas about the future of in vitro fertilization and the andrology laboratory. Although we have seen much progress and innovation in the laboratory over the years, there is still much to come, and this article looks at what these leaders think will be imp...
Article
The in vitro fertilization and andrology laboratories are at the center of assisted reproductive technologies and the place where technicians and embryologists manipulate gametes and preimplantation-stage embryos with the goal of achieving the best embryo for transfer. Through the years, these laboratories have seen developments in technique, techn...
Article
Conditioning Medicine 4(2): 88-99. Transitions through pluripotent stem cell states, differentiation, and reprogramming, involve substantial metabolic remodeling. These metabolic transitions are only just beginning to be understood, often relying on transcriptional data to infer metabolism, rather than actual metabolic outputs. Here, we consider t...
Article
Study question: Can vascular endothelial growth factor (VEGF)-loaded silica supraparticles (V-SPs) be used as a novel mode of delivering VEGF to the developing preimplantation embryo in vitro? Summary answer: Supplementation of embryo culture media with V-SPs promoted embryonic development in a manner equivalent to media supplemented with free V...
Article
Full-text available
Within the maternal tract, the preimplantation embryo is exposed to an array of growth factors and cytokines, most of which are absent from culture media used in clinical IVF. Whilst the addition of individual GFs and cytokines to embryo culture media can improve preimplantation mouse embryo development, there is a lack of evidence on the combined...
Chapter
Patient-Centered Assisted Reproduction - edited by Alice D. Domar March 2020
Article
Nicotinamide adenine dinucleotide (NAD+ ) and its precursor metabolites are emerging as important regulators of both cell metabolism and cell state. Interestingly, the role of NAD+ in human embryonic stem cell (hESC) metabolism and the regulation of pluripotent cell state is unresolved. Here we show that NAD+ simultaneously increases hESC mitochond...
Article
Full-text available
Study question: What is the effect of antioxidants acetyl-L-carnitine, N-acetyl-L-cysteine and α-lipoic acid (A3) in vitrification and warming solutions on mouse blastocyst development and viability? Summary answer: The combination of three antioxidants in vitrification solutions resulted in mouse blastocysts with higher developmental potential...
Article
Full-text available
Human induced pluripotent stem cells (iPSCs) can be differentiated in vitro into bona fide cardiomyocytes for disease modelling and personalized medicine. Mitochondrial morphology and metabolism change dramatically as iPSCs differentiate into mesodermal cardiac lineages. Inhibiting mitochondrial fission has been shown to promote cardiac differentia...
Article
Full-text available
Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in...
Chapter
Morphological assessment of the human preimplantation embryo has been used for 40 years to try to quantitate developmental potential. Although certain traits of embryo development appear linked to viability, the assessment of morphology alone remains subjective and hard to quantitate. Metabolic activity of embryos has been linked to viability post...
Chapter
Blastocyst culture and transfer for human IVF has resulted in an increase in implantation and live birth rates and successfully facilitated the move toward single embryo transfer. Initially this was attained through the development and introduction of sequential media, designed to mirror the changing nutritional environments within the oviduct and...
Chapter
The first culture media designed specifically to support development of the preimplantation mouse embryo were formulated over 50 years ago and were based on balanced salt solutions, containing the carbohydrates pyruvate, lactate, and glucose as the sole energy sources. Such media used a bicarbonate–carbon dioxide buffer system to maintain the desir...
Article
Full-text available
Metabolism has been shown to alter cell fate in human pluripotent stem cells (hPSC). However, current understanding is almost exclusively based on work performed at 20% oxygen (air), with very few studies reporting on hPSC at physiological oxygen (5%). In this study, we integrated metabolic, transcriptomic, and epigenetic data to elucidate the impa...
Article
Full-text available
Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diag- nose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role...
Article
Full-text available
Reprogramming to pluripotency involves drastic restructuring of both metabolism and the epigenome. However, induced pluripotent stem cells (iPSC) retain transcriptional memory, epigenetic memory, and metabolic memory from their somatic cells of origin and acquire aberrant characteristics distinct from either other pluripotent cells or parental cell...
Article
The transition to pluripotency invokes profound metabolic restructuring, however reprogramming is accompanied by the retention of somatic cell metabolic and epigenetic memory. Modulation of metabolism during reprogramming has been shown to improve reprogramming efficiency, yet it is not known how metabolite availability during reprogramming affects...
Article
Research question: Does single embryo culture under atmospheric or reduced oxygen alter preimplantation metabolism and post-implantation development compared with culture in groups? Design: Mouse embryos were cultured under 5% or 20% oxygen, individually or in groups of 10. Spent media were analysed after 48, 72 and 96 h of culture. Blastocysts...
Chapter
How to Prepare the Egg and Embryo to Maximize IVF Success - edited by Gabor Kovacs January 2019
Chapter
How to Prepare the Egg and Embryo to Maximize IVF Success - edited by Gabor Kovacs January 2019
Article
As human pluripotent stem cells (hPSC) exit pluripotency, they reportedly switch from glycolytic energy production to primarily mitochondrial metabolism. Here we show that upon ectoderm differentiation to neural precursor cells (NPC), hPSC increase glycolytic rate, ultimately producing more carbon as lactate than consumed as glucose. However, gluco...
Conference Paper
Oxygen is a key regulator of stem cell metabolism and fate. Induced pluripotent stem cells (iPSC) are routinely derived and cultured in atmospheric (20%) oxygen, despite evidence for physiological (~5%) oxygen improving embryonic stem cell (ESC) establishment, metabolism and pluripotency. Reprogramming to pluripotency invokes profound metabolic cha...
Conference Paper
A main goal for human embryonic stem cell (hESC) research is to differentiate hESC into specialised cell types. Significantly, the metabolism and nutritional requirements of a cell change with cell state. Yet, no comprehensive study exists on the daily changes in metabolism throughout hESC differentiation, which is necessary for optimising targeted...
Article
Full-text available
Reprogramming somatic cells to a pluripotent cell state (induced Pluripotent Stem (iPS) cells) requires reprogramming of metabolism to support cell proliferation and pluripotency, most notably changes in carbohydrate turnover that reflect a shift from oxidative to glycolytic metabolism. Some aspects of iPS cell metabolism differ from embryonic stem...
Data
Metabolite utilisation by MEL1 human ES, PDL, NHF1.3 and IMR90 human iPS cells independent of oxygen. (A) Total amino acid production, consumption and turnover. (B) Glucose consumption and lactate production. Spent media samples were collected after a 24-hour incubation period (day 4–5 of passage), normalised to cell number and an internal standard...
Data
Carbohydrate utilisation in PDL (A, B) and IMR90 (C, D) fibroblasts in response to oxygen. (A, C) Glucose consumption, quantified in spent medium samples, normalised to cell number and an unspent medium control. (B, D) Lactate production, quantified in spent medium samples, normalised to cell number and an unspent medium control Black bars: 5% oxyg...
Preprint
Full-text available
Our understanding of genetic mechanisms driving early embryonic development is primarily based on experiments conducted on mice, however translation of findings can be limited by physiological differences between mice and humans. To address this, we investigated whether the spiny mouse (Acomys cahirinus) is a closer model of early human embryonic d...
Article
The need to identify the most viable embryo following in vitro fertilization (IVF) was established early in the history of human IVF. The stalwart of identifying the best embryos has been morphology. Other techniques have however seen wide acceptance, including the use of preimplantation genetic screening, even though concerns exist over the invasi...
Article
Full-text available
Objective In vitro culture of preimplantation embryos is improved by grouping embryos together in a drop of media. Individually cultured embryos are deprived of paracrine factors; with this in mind, we investigated whether the addition of a single embryo-secreted factor, interleukin-6 (IL-6), could improve the development of individually cultured e...
Data
Addition of recombinant mouse IL-6 to mouse embryo culture
Data
Addition of recombinant human IL-6 to mouse embryo culture
Article
Full-text available
Spiny mice of the genus Acomys display several unique physiological traits, including menstruation and scar-free wound healing; characteristics that are exceedingly rare in mammals, and of considerable interest to the scientific community. These unique attributes, and the potential for spiny mice to accurately model human diseases, are driving incr...
Article
Full-text available
Metabolism is central to embryonic stem cell (ESC) pluripotency and differentiation, with distinct profiles apparent under different nutrient milieu, and conditions that maintain alternate cell states. The significance of altered nutrient availability, particularly oxygen, and metabolic pathway activity has been highlighted by extensive studies of...
Article
Full-text available
The phenotype of the human embryo conceived through in vitro fertilization (IVF), that is its morphology, developmental kinetics, physiology and metabolism, can be affected by numerous components of the laboratory and embryo culture system (which comprise the laboratory environment). The culture media formulation is important in determining embryo...
Article
Full-text available
Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3...
Method
Full-text available
De novo transcriptome assembly workflow
Article
Full-text available
Multiple pluripotent cell populations, which together comprise the pluripotent cell lineage, have been identified. The mechanisms that control the progression between these populations are still poorly understood. The formation of early primitive ectoderm-like (EPL) cells from mouse embryonic stem (mES) cells provides a model to understand how one...
Data
The impact of signaling inhibitors on the action of l-proline. A, B. ES cells were cultured in medium supplemented with 200 μM l-proline and DMSO (■) or l-proline and 10 μM PP2 (□) (A) or 10 μM SB203580 (□)(B), for 4 days. RNA from these cells was analyzed for transcripts of Oct4, Sox2, Nanog, Rex1, Spp1, Gbx2, Dnmt3b, Otx2 and Fgf5 by real-time PC...
Data
Details of primers and antibodies used in this research. (DOCX)
Data
A role for p38 MAPK signaling in EPL cell formation. A. ES cells were treated with LIF or 100 μM of l-proline for 5 or 20 minutes, as indicated. Cells were lysed and protein bound to the kinome array and binding quantified. Binding to antibodies specific for pp38α, pp38β, pHsbp2 and MSK2 is shown; n = 2, values have been averaged. B. WT ES cell and...
Data
PP2 impacts the colony morphology, proliferation rate and differentiation kinetics of pluripotent cells in cluture. A. ES cells were cultured in ESCM and ESCM + 200 μM L-proline with or without 10 μM PP2, as indicated, for 4 days. Scale bar = 200 μm. B. ES cells were cultured in MEDII + DMSO and MEDII + 5, 10 or 20 μM PP2 for 3 days. Scale bar = 20...
Data
The effect of inhibiting Src family kinase signaling with SU6656. ES cells were cultured in MEDII + DMSO and MEDII + 1, 2 or 4 μM SU6656 for 3 days. Scale bar = 200 μm. (TIF)
Article
Full-text available
Embryo implantation requires synchronized dialogue between the receptive endometrium and activated blastocyst via locally produced soluble mediators. During the mid-secretory (MS) phase of the menstrual cycle, increased glandular secretion into the uterine lumen provides important mediators that modulate the endometrium and support the conceptus du...