Non-viable human embryos as a source of viable cells for embryonic stem cell derivation

When embryology meets genetics: the definition of developmentally incompetent preimplantation embryos (DIPE)-the consensus of two Italian scientific societies

A clear definition of developmentally incompetent preimplantation embryo (DIPE) in literature is still missing, while several scientific societies are discussing this challenging topic. From both a clinical and scientific perspective, the identification of embryos unfit for reproductive purpose is crucial. This aim should be pursued in light of all diagnostic technologies for embryo evaluation, encompassing also genetic analyses, of recent implementation in IVF. The Italian context is characterized by an unusual scenario: embryos can be discarded only if not viable and cannot be used for research purposes either. Therefore, thousands of embryos, diagnosed as affected and/or aneuploid as resulting from preimplantation genetic testing (PGT) and clinically not utilizable, are cryopreserved and stored indefinitely, with important psychological, legal, and financial implications. With the aim of updating the definition of DIPE, also on the basis of the embryo genetic status, the Italian Society of Embryology, Reproduction and Research (SIERR) and the Italian Society of Human Genetic (SIGU) reviewed the literature on this topic, found a consensus, and produced a list of relevant criteria.

The Shortage of Malaysian Stem Cell Ethics in Mainstream Database: a Preliminary Study

Ethics is a philosophical branch of inquiry that reasons between what is right and wrong. The moral philosophy of Socrates, Aristotle, and Plato from ancient Greek became the basis of most of the western ethics. These days, ethics can be divided based on its inquiries for example, normative, descriptive, metaethics, and applied ethics or based on its theories like utilitarianism, emotivism, and universal ethics. In context with applied ethics that examines issues involving emerging technologies, this study will look into the ethics of Malaysian stem cell technology based on written literature. It was mainly to identify Malaysian literature on stem cell ethics through conventional search since the mainstream international database indicated an obvious shortage. The critical review of this literature will facilitate in the understanding of unique position of Malaysia towards stem cell and its ethics in reference to the limited number. Despite the limitation, this can be a preliminary study urging for more inquiries and exploration to fulfil the multiple perspectives in ethics such as the diversity of Malaysian ethics, the impact of ethics in stem cell regulation in Malaysia, and if western contemporary ethics influences Malaysian ethics particularly involving stem cell technology.

Patent eligibility of stem cells in Europe: where do we stand after 8 years of case law?

Since 2006, some of the highest ranking European Courts have issued decisions related to the patent eligibility of human embryonic stem cells. The question of patent eligibility of human embryonic stem cells remains, however, still erratic, at least in some aspects. This article will give a short comprehensive overview of the case history, and discuss questions still unsolved.

European stem cell research in legal shackles

Advances in stem cell biology have raised legal challenges to the patentability of stem cells and any derived technologies and processes. In 1999, Oliver Brüstle was granted a patent for the generation and therapeutic use of neural cells derived from human embryonic stem cells (hESCs). The patent was challenged and put before the European Court of Justice, which ruled that inventions involving the prior destruction of human embryos cannot be patented. The legal maneuvering around this case demonstrates that the future of stem cell-based patents in Europe remains unsettled. Furthermore, owing to the European Court's broad definition of hESC as 'any cell that is capable of commencing development into a human being,' novel technologies that could eliminate the need for hESCs, such as induced pluripotent stem cells (iPSCs), are at risk of being included under the same ruling. Advances in the in vitro development of germ cells from pluripotent stem cells may one day provide a direct developmental path from iPSC to oocyte and sperm, and, according to the European Court's reasoning, legally equate iPSCs with human embryos. In this review, we will briefly discuss the Brüstle v Greenpeace case and the implications of the European Court of Justice's ruling. We will identify potential risks for stem cell research and future therapeutics resulting from the broad legal definition of the human embryo. Finally, we will broach the current legal landscape, as this broad definition has also created great uncertainty about the status of human iPSCs.

Derivation of human embryonic stem cell lines from single blastomeres of low-quality embryos by direct plating

PURPOSE

To explore a simple method of establishing pluripotent human embryonic stem cell (hESC) lines from single blastomeres of low-quality (LQ) embryos.

METHODS

Blastomeres were isolated from normally fertilized, day-3 pre-implantation LQ embryos by dissolving of the zona pellucida and were then plated directly onto inactivated human foreskin fibroblasts. The subsequent culture was identical to that used to derive a hESC line from the inner cell mass of a blastocyst. The established hESC lines were passaged and characterized.

RESULTS

Two hESC lines were produced by culturing the blastomeres individually in a hESC culture system (hESC-CS). Both of the hESC lines maintained a normal 46-chromosome XY karyotype, expressed stemness markers, and showed a pluripotent phenotype, including the ability to differentiate into all three germ layers in vitro and in vivo.

CONCLUSIONS

The blastomeres of LQ embryos have a developmental capacity that necessitates prolonged culture. Plating of blastomeres from LQ embryos directly into the hESC-CS is a feasible method for deriving hESC lines.

Establishment, characterization, and differentiation of a karyotypically normal human embryonic stem cell line from a trisomy-affected embryo

Derivation of human embryonic stem cell (hESC) lines from chromosomally or genetically abnormal embryos obtained following preimplantation genetic diagnosis (PGD) is of immense interest to study various kinds of genetic disorders. In this study, we have established a new hESC line Relicell(®)hES4, isolated from an aneuploid embryo. Derivation of this cell line was achieved by isolation of the inner cell mass (ICM) by mechanical method. Karyotype analysis showed that the hESC line is euploid having 46 chromosomes, contrary to our expectations. The undifferentiated cells exhibited long-term proliferation capacity and expressed markers typical for hESC, such as OCT4, NANOG, and SSEA4. A comparative microarray study was carried out to analyze the transcription profile of Relicell(®)hES4 along with three other normal hESC line generated earlier in our lab. Relicell(®)hES4 manifested pluripotent differentiation potential both in vivo and in vitro. The cells were also induced to form neurons, cardiomyocytes, and pancreatic β islets. The generation of a normal hESC line from an abnormal embryo points to the fact that even such embryos can be considered for deriving new hESC lines instead of discarding them. The data represented here are the first detailed report on characterization and differentiation of an Indian hESC line generated from a PGD analyzed embryo.

Intracytoplasmic morphologically selected sperm injection improves development and quality of preimplantation embryos in teratozoospermia patients

This prospective randomized study investigated whether intracytoplasmic sperm injection (ICSI) outcome can be improved with sperm preselection under ×6000 magnification and intracytoplasmic morphologically selected sperm injection (IMSI) in patients with teratozoospermia and characterized embryo development and quality regarding sperm morphology and presence of head vacuoles. Couples with isolated teratozoospermia were divided into two groups: IMSI group (n=52) and ICSI group (n=70) and fertilization, blastocyst and clinical pregnancy rates were compared. Oocytes from 30 randomly chosen patients from the IMSI group were injected with spermatozoa that had been previously classified under ×6000 magnification into four classes according to the number and size of vacuoles in the head and then cultured separately. Pronuclear morphology, embryo development and blastomere viability were estimated to investigate the influence of sperm morphology, especially vacuoles, on embryo developmental capacity. A significantly higher clinical pregnancy rate was achieved in the IMSI group compared with the ICSI group (48% versus 24%, P<0.05). Fertilization with spermatozoa without head vacuoles yielded higher number of morphologically normal zygotes, higher blastocyst rate and smaller proportion of arrested embryos than spermatozoa with vacuoles and other head defects. IMSI is a method of choice in patients with teratozoospermia.

Derivation of two new human embryonic stem cell lines from nonviable human embryos

We report the derivation and characterization of two new human embryonic stem cells (hESC) lines (CU1 and CU2) from embryos with an irreversible loss of integrated organismic function. In addition, we analyzed retrospective data of morphological progression from embryonic day (ED) 5 to ED6 for 2480 embryos not suitable for clinical use to assess grading criteria indicative of loss of viability on ED5. Our analysis indicated that a large proportion of in vitro fertilization (IVF) embryos not suitable for clinical use could be used for hESC derivation. Based on these combined findings, we propose that criteria commonly used in IVF clinics to determine optimal embryos for uterine transfer can be employed to predict the potential for hESC derivation from poor quality embryos without the destruction of vital human embryos.

Comparison of three embryo culture methods for derivation of human embryonic stem cells from discarded embryos

Human embryonic stem cells (hESC) are self-renewing and pluripotent cells that hold great promise. Our objective was to compare the effect of three different embryo culture methods for derivation of human embryonic stem cells from discarded embryos. A prospective and randomized trial was conducted using 381 discarded human embryos at days 2-3 postfertilization in Beijing Obstetrics and Gynecology Hospital IVF center. After removal of the zona pellucida, discarded human embryos were cultured by three different methods as multiple embryo aggregates, single embryo, and blastomeres. Outgrowth of embryos and hESC derivation were observed. The outgrowth rate of embryos cultured as multiple embryo aggregates was higher than that of those cultured as single embryos or blastomeres (p < 0.05). Three propagating hESC lines were derived from poor quality day 2-3 postfertilization nonblastocyst embryos cultured as multiple embryo aggregates. Derived hESC lines expressed hESC-specific markers of pluripotency and had normal diploid karyotype. The cells were able to form derivatives of all three germ layers in vivo as teratomas. Our results demonstrate that culturing these discarded embryos as multiple embryo aggregates was more profitable for outgrowth and derivation of ESC line than culturing these as single embryo or blastomeres.