The ethical challenges of the clinical introduction of mitochondrial replacement techniques

Targeting mitochondria for ovarian aging: new insights into mechanisms and therapeutic potential

Ovarian aging is a complex process characterized by a decline in oocyte quantity and quality, directly impacting fertility and overall well-being. Recent researches have identified mitochondria as pivotal players in the aging of ovaries, influencing various hallmarks and pathways governing this intricate process. In this review, we discuss the multifaceted role of mitochondria in determining ovarian fate, and outline the pivotal mechanisms through which mitochondria contribute to ovarian aging. Specifically, we emphasize the potential of targeting mitochondrial dysfunction through innovative therapeutic approaches, including antioxidants, metabolic improvement, biogenesis promotion, mitophagy enhancement, mitochondrial transfer, and traditional Chinese medicine. These strategies hold promise as effective means to mitigate age-related fertility decline and preserve ovarian health. Drawing insights from advanced researches in the field, this review provides a deeper understanding of the intricate interplay between mitochondrial function and ovarian aging, offering valuable perspectives for the development of novel therapeutic interventions aimed at preserving fertility and enhancing overall reproductive health.

'Recombining' biological motherhoods. Towards two 'complete' biological mothers

Within feminist literature from the early 1970s to this day, assisted reproductive technologies have been largely known to divide, replace or eliminate biological motherhood. For example, while in the past biological motherhood was considered a continuous experience, in vitro fertilisation (IVF) and IVF using egg donation allowed a split between two biological mothers, one providing eggs (genetic mother) and the other one gestation (gestational mother). This split was considered irreparable: the genetic mother could not be also gestational, and vice versa. On the contrary, this paper aims to show that assisted reproductive technologies may also have a constructive potential towards biological motherhood(s). To explain how it could be possible, two existing techniques are explored: the first is maternal spindle transfer, which allows a double genetic motherhood; the second is reciprocal effortless IVF, which supposedly enables a double gestational motherhood. While in the first part, these techniques are examined singularly, in the second part a feasible combination of them is speculated. The idea is that assisted reproductive technologies could 'recombine' genetic and gestational motherhood in two figures that include both, namely in two 'complete' biological mothers, both genetic and gestational.

Mesenchymal Stromal Cell Mitochondrial Transfer as a Cell Rescue Strategy in Regenerative Medicine: A Review of Evidence in Preclinical Models

Mesenchymal stromal cells (MSC) have excellent clinical potential and numerous properties that ease its clinical translation. Mitochondria play a crucial role in energy metabolism, essential for cellular activities, such as proliferation, differentiation, and migration. However, mitochondrial dysfunction can occur due to diseases and pathological conditions. Research on mitochondrial transfer from MSCs to recipient cells has gained prominence. Numerous studies have demonstrated that mitochondrial transfer led to increased adenosine triphosphate (ATP) production, recovered mitochondrial bioenergetics, and rescued injured cells from apoptosis. However, the complex mechanisms that lead to mitochondrial transfer from healthy MSCs to damaged cells remain under investigation, and the factors contributing to mitochondrial bioenergetics recovery in recipient cells remain largely ambiguous. Therefore, this review demonstrates an overview of recent findings in preclinical studies reporting MSC mitochondrial transfer, comprised of information on cell sources, recipient cells, dosage, route of administration, mechanism of transfer, pathological conditions, and therapeutic effects. Further to the above, this research discusses the potential challenges of this therapy in its clinical settings and suggestions to overcome its challenges.

Genetic ethics and mtDNA replacement techniques

The United Kingdom parliament made history in 2015 when they voted to allow the use of mitochondrial (mtDNA) replacement techniques. Mitochondrial diseases are genetically inherited and currently, the only known cure is replacement therapies. However, most other countries have been slow to adopt policy changes that allow for mtDNA replacement due to the ethical challenges of the techniques. While there are ethical challenges concerning mtDNA replacement, there is a need to address these challenges and allow these techniques in the US to provide treatment for individuals affected. This paper first addresses mitochondrial diseases and replacement techniques currently used and analyzes ethical challenges related to the interventions, such as safety, efficacy, and contributed genetic material from three individuals. This paper then addresses how the ethical principles, beneficence, nonmaleficence, autonomy and justice support mtDNA replacement. Suggestions on how the US can allow mtDNA replacement by adopting similar policy changes to the UK are provided, as well as additional measures to protect patients. Given the rate of individuals affected, severity of mitochondrial diseases, and lack of treatment options available, it's important to address how to overcome ethical challenges and policy barriers.

Public attitudes towards novel reproductive technologies: a citizens' jury on mitochondrial donation

STUDY QUESTION

Does an informed group of citizens endorse the clinical use of mitochondrial donation in a country where this is not currently permitted?

SUMMARY ANSWER

After hearing balanced expert evidence and having opportunity for deliberation, a majority (11/14) of participants in a citizens’ jury believed that children should be able to be born using mitochondrial donation.

WHAT IS KNOWN ALREADY

Research suggests that patients, oocyte donors and health professionals support mitochondrial donation to prevent transmission of mitochondrial disease. Less is known about public acceptability of this novel reproductive technology, especially from evidence using deliberative methods.

STUDY DESIGN, SIZE, DURATION

This study comprised a citizens’ jury, an established method for determining the views of a well-informed group of community members. The jury had 14 participants, and ran over one and a half days in 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Jurors were members of the public with no experience of mitochondrial disease. They heard and engaged with relevant evidence and were asked to answer the question: ‘Should Australia allow children to be born following mitochondrial donation?’

MAIN RESULTS AND THE ROLE OF CHANCE

Eleven jurors decided that Australia should allow children to be born following mitochondrial donation; 7 of whom added conditions such as the need to limit who can access the intervention. Three jurors decided that children should not (or not yet) be born using this intervention. All jurors were particularly interested in the reliability of evidence, licensing/regulatory mechanisms and the rights of children to access information about their oocyte donors.

LIMITATIONS, REASONS FOR CAUTION

Jurors’ views were well informed and reflected critical deliberation and discussion, but are not intended to be representative of the whole population.

WIDER IMPLICATIONS OF THE FINDINGS

When presented with high quality evidence, combined with opportunities to undertake structured deliberation of novel reproductive technologies, members of the public are able to engage in detailed discussions. This is the first study to use an established deliberative method to gauge public views towards mitochondrial donation.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by a University of Sydney Industry and Community Collaboration Seed Award (2017), which was awarded contingent on additional funding from the Mito Foundation. Additional funding was provided by the Mito Foundation. The Foundation was not involved in jury facilitation or deliberation, nor analysis of research data.

TRIAL REGISTRATION NUMBER

Not applicable.

Should mitochondrial replacement therapy be funded by the National Health Service?

A clinical trial on mitochondrial replacement therapy (MRT) is currently being conducted and if this technique proves effective, National Health Service (NHS) England will fund MRT through the highly specialised services (HSS) funding stream. This paper considers whether MRT should be publicly funded by the NHS. Given the current financial pressure the NHS is experiencing, a comprehensive discussion is essential. There is yet to be a thorough discussion on MRT funding, perhaps because this is a small-scale issue and presumed to be covered by the HSS budget. However, the source of funding has not been confirmed due to the trial's incompletion. Upon its completion, reasoned decisions need to be made over the allocation of scarce NHS resources. It is therefore important to consider the following arguments in advance. Three arguments given against NHS funding of MRT will be evaluated. The first argument against NHS funding examines the HSS overspending its budget in an underfunded NHS, suggesting funding must be carefully reprioritised. Second, the ethical issue of allowing public access to a technique with insufficient evidence behind it will be explored. The final point considers the option of privately funding MRT and how this would affect the treatment's development. After illustrating the weaknesses of such arguments, it will be concluded that MRT should be funded by the NHS.

Should Long-Term Follow-up Post-Mitochondrial Replacement be Left up to Physicians, Parents, or Offspring?

UK law permits parents to use mitochondrial replacement (MR) to have genetically-related children without serious mitochondrial disease. However, long-term follow-up is required for each case. Whether this follow-up should be left to physicians, parents, or offspring has not been established. Due to the experimental status of MR, physicians must inform parents of the risks and the importance of follow-up tailored to a specific mitochondrial disease. Given that the use of MR is a responsible exercise of reproductive freedom, parents should ensure that the follow-up is performed properly and in the best interests of their offspring. On becoming legally competent, the resulting children should be entitled to refuse follow-up provided that the prevention of mitochondrial disease with no adverse effects has been evident till then. This offspring-centred long-term follow-up approach might also be applied to the use of MR for infertility treatment, even though the primary endpoint is healthy live births.

Genome Modifying Reproductive Procedures and their Effects on Numerical Identity

The advantages and risks of a number of new genome modifying procedures seeking to create healthy or enhanced individuals, such as Maternal Spindle Transfer, Pronuclear Transfer, Cytoplasmic Transfer and Genome Editing, are currently being assessed from an ethical perspective, by national and international policy organizations. One important aspect being examined concerns the effects of these procedures on different kinds of identity. In other words, whether or not a procedure only modifies the qualities or properties of an existing human being, meaning that merely the qualitative identity of this single individual is affected, or whether a procedure results in the creation of a new individual, meaning that a numerically distinct human being would have come into existence. In this article, the different identity arguments proposed, so far, are presented with respect to these novel reproductive procedures. An alternative view is then developed using the Origin Essentialism argument to indicate that any change in the creative conditions of an individual such as in his or her biology but also the moment in time, and the three dimensions of space, will have a numerical identity effect and bring into existence a new individual who would not, otherwise, have existed. Because of this, it is concluded that a form of selection may have taken place in which a preference was expressed for one new possible individual instead of another, based on some frame of reference. This may then mean that a selection between persons has occured  contravening the European Union Charter of Fundamental Rights which was ratified in 2000.

Mandatory sex selection and mitochondrial transfer

The Institute of Medicine has recently endorsed arguments put forward by John Appleby calling for mandatory sex selection against female offspring in the initial trials of mitochondrial replacement techniques. In this paper I argue that, despite this endorsement, the reasons offered by Appleby for mandatory sex selection are inadequate. I further argue that plausible revisions to Appleby's arguments still fail to convincingly defend such an intrusive policy. While I remain neutral about whether intending parents making use of mitochondrial replacement techniques ought to have access to sex selection, I conclude that to date the case for mandatory sex selection has not been satisfactorily made.

Genome editing and assisted reproduction: curing embryos, society or prospective parents?

This paper explores the ethics of introducing genome-editing technologies as a new reproductive option. In particular, it focuses on whether genome editing can be considered a morally valuable alternative to preimplantation genetic diagnosis (PGD). Two arguments against the use of genome editing in reproduction are analysed, namely safety concerns and germline modification. These arguments are then contrasted with arguments in favour of genome editing, in particular with the argument of the child's welfare and the argument of parental reproductive autonomy. In addition to these two arguments, genome editing could be considered as a worthy alternative to PGD as it may not be subjected to some of the moral critiques moved against this technology. Even if these arguments offer sound reasons in favour of introducing genome editing as a new reproductive option, I conclude that these benefits should be balanced against other considerations. More specifically, I maintain that concerns regarding the equality of access to assisted reproduction and the allocation of scarce resources should be addressed prior to the adoption of genome editing as a new reproductive option.

Mitochondrial Replacement Techniques: Remaining Ethical Challenges

Recent developments in the field of mitochondrial replacement technique (MRT) research and clinical practice have raised ethical concerns worldwide. We argue that the future use of MRTs requires a concerted effort among the global research and clinical community to implement and enforce responsible innovation and governance.

Should Mitochondrial Donation Be Anonymous?

Currently in the United Kingdom, anyone donating gametes has the status of an open-identity donor. This means that, at the age of 18, persons conceived with gametes donated since April 1, 2005 have a right to access certain pieces of identifying information about their donor. However, in early 2015, the UK Parliament approved new regulations that make mitochondrial donors anonymous. Both mitochondrial donation and gamete donation are similar in the basic sense that they involve the contribution of gamete materials to create future persons. Given this similarity, this paper presumes that both types of donor should be treated the same and made open-identity under the law, unless there is a convincing argument for treating them differently. I argue that none of the existing arguments that have been made so far in favor of mitochondrial donor anonymity are convincing and mitochondrial donors should therefore be treated as open-identity donors under UK law.

Mitochondrial Donation: A Boon or Curse for the Treatment of Incurable Mitochondrial Diseases

Mitochondria are present in all human cells and vary in number from a few tens to many thousands. As they generate the majority of a cell's energy supply which power every part of our body, and hence, their number varies in different cells as per the energy requirement of the cell. Mitochondria have their own separate DNA, which carries total 13 genes. All of these 13 genes are involved in energy production. For normal functioning of cells, the mitochondria need to be healthy. Unhealthy mitochondria can cause severe medical disorders known as mitochondrial disease. In case of mitochondrial disease, the most commonly affected organs are the heart, kidney, skeletal muscle, and brain. The diseases related to defects in these organs are quite prevalent in the society. Majority of these mitochondrial diseases are caused by genetic defects (mutations) in the mitochondrial DNA. Unlike nuclear genes, mitochondrial DNA is inherited only from our mother. Mothers can carry abnormal mitochondria and be at risk of passing on the serious disease to their children, even if they themselves show only mild or no symptoms. Due to the complex nature of these diseases, their diagnosis and therapy are very difficult. Hence, till now, only the different methods for management of these diseases are known. However, after understanding the complexity related to the cure of these diseases, alternative methods have been developed to minimize/stop the transfer of mitochondrial diseases from mother to offspring. This latest technique is called mitochondrial replacement or "donation." In the present review, we are discussing the methodological details and issues related to the technique of mitochondrial donation. Our study is also a step toward raising awareness about mitochondrial diseases and advocating for the legalization of mitochondrial donation, a revolutionary in vitro fertilization technique.

The (Re) Production of the Genetically Related Body in Law, Technology and Culture: Mitochondria Replacement Therapy

Advances in medicine in the latter half of the twentieth century have dramatically altered human bodies, expanding choices around what we do with them and how they connect to other bodies. Nowhere is this more so than in the area of reproductive technologies (RTs). Reproductive medicine and the laws surrounding it in the UK have reconfigured traditional boundaries surrounding parenthood and the family. Yet culture and regulation surrounding RTs have combined to try to ensure that while traditional boundaries may be pushed, they are reconstructed in similar ways. This paper looks at the most recent RT to be permitted in the UK, mitochondria (mtDNA) replacement therapy (MRT). Despite controversial media headlines surrounding the technique, MRT is in fact an example of how science and regulation seek to expand models of traditional relatedness in a way that doesn’t challenge the existing order. Yet, like other RTs, while attempts are made to ensure it doesn’t push traditional boundaries too far, fissures and inconsistencies appear in law and culture, which give interesting insights into how genetics, parentage and identity are being mediated in new but familiar ways.

A 14-day limit for bioethics: the debate over human embryo research

BACKGROUND

This article explores the reasons in favour of revising and extending the current 14-day statutory limit to maintaining human embryos in culture. This limit is enshrined in law in over a dozen countries, including the United Kingdom. In two recently published studies (2016), scientists have shown that embryos can be sustained in vitro for about 13 days after fertilisation. Positive reactions to these results have gone hand in hand with calls for revising the 14-day rule, which only allows embryo research until the 14th day after fertilisation.

MAIN TEXT

The article explores the most prominent arguments in favour of and against the extension of the 14-day limit for conducting research on human embryos. It situates these arguments within the history of the 14-day limit. I start by discussing the history of the 14-day limit in the United Kingdom and the reasons behind the decision to opt for a compromise between competing moral views. I then analyse the arguments that those who are generally in favour of embryo research put forward in support of extending the 14-day rule, namely (a) the argument of the beneficence of research and (b) the argument of technical feasibility (further explained in the article). I then show how these two arguments played a role in the recent approval of two novel techniques for the replacement of faulty mitochondrial DNA in the United Kingdom. Despite the popularity and widespread use of these arguments, I argue that they are ultimately problematic and should not be straightforwardly accepted (i.e. accepted without further scrutiny). I end by making a case for respecting value pluralism in the context of embryo research, and I present two reasons in favour of respecting value pluralism: the argument of public trust and the argument of democracy.

CONCLUSION

I argue that 14-day limit for embryo research is not a valuable tool despite being a solution of compromise, but rather because of it. The importance of respecting value pluralism (and of respecting different views on embryo research) needs to be considered in any evaluation concerning a potential change to the 14-day rule.

Mitochondrial replacement techniques: egg donation, genealogy and eugenics

Several objections against the morality of researching or employing mitochondrial replacement techniques have been advanced recently. In this paper, I examine three of these objections and show that they are found wanting. First I examine whether mitochondrial replacement techniques, research and clinical practice, should not be carried out because of possible harms to egg donors. Next I assess whether mitochondrial replacement techniques should be banned because they could affect the study of genealogical ancestry. Finally, I examine the claim that mitochondrial replacement techniques are not transferring mitochondrial DNA but nuclear DNA, and that this should be prohibited on ethical grounds.