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Tang BL. Debates on humanization of human-animal brain chimeras - are we putting the cart before the horses? MEDICINE, HEALTH CARE, AND PHILOSOPHY 2024:10.1007/s11019-024-10209-8. [PMID: 38797779 DOI: 10.1007/s11019-024-10209-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/04/2024] [Indexed: 05/29/2024]
Abstract
Research on human-animal chimeras have elicited alarms and prompted debates. Those involving the generation of chimeric brains, in which human brain cells become anatomically and functionally intertwined with their animal counterparts in varying ratios, either via xenografts or embryonic co-development, have been considered the most problematic. The moral issues stem from a potential for "humanization" of the animal brain, as well as speculative changes to the host animals' consciousness or sentience, with consequential alteration in the animal hosts' moral status. However, critical background knowledge appears to be missing to resolve these debates. Firstly, there is no consensus on animal sentience vis-à-vis that of humans, and no established methodology that would allow a wholesome and objective assessment of changes in animal sentience resulting from the introduction of human brain cells. Knowledge in interspecies comparative neuropsychology that could allow effective demarcation of a state of "humanization" is also lacking. Secondly, moral status as a philosophical construct has no scientific and objective points of reference. Either changes in sentience or humanization effects would remain unclear unless there are some neuroscientific research grounding. For a bioethical stance based on moral status of human-animal brain chimera to make meaningful contributions to regulatory policies, it might first need to be adequately informed by, and with its arguments constructed, in a manner that are factually in line with the science. In may be prudent for approved research projects involving the generation of human-animal brain chimera to have a mandatory component of assessing plausible changes in sentience.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 8 Medical Dr, Singapore, 117596, Singapore.
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Abstract
Non-human animal chimeras, containing human neurological cells, have been created in the laboratory. Despite a great deal of debate, the status of such beings has not been resolved. Under normal definitions, such a being could either be unconventionally human or abnormally animal. Practical investigations in animal sentience, artificial intelligence, and now chimera research, suggest that such beings may be assumed to have no legal rights, so philosophy could provide a different answer. In this vein, therefore, we can ask: What would a chimera, if it could think, think about? Thinking is used to capture the phenomena of a novel, chimeric being perceiving its terrible predicament as no more than a laboratory experiment. The creation of a thinking chimera therefore forces us to reconsider our assumptions about what makes human beings (potentially) unique (and other sentient animals different), because, as such, a chimera's existence bridges our social and legal expectations about definitions of human and animal. Society has often evolved new social norms based on different kinds of (ir)rational contrivances; the imperative of non-contradiction, which is defended here, therefore requires a specific philosophical response to the rights of a thinking chimeric being.
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Affiliation(s)
- Benjamin Capps
- Department of Bioethics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Human-Animal Chimeras: New Solution for Organ Xenotransplantation or Ethical and Metaphysical Dilemma? J Craniofac Surg 2023; 34:3-8. [PMID: 35949027 DOI: 10.1097/scs.0000000000008885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Brown JL, Voth JP, Person K, Low WC. A Technological and Regulatory Review on Human-Animal Chimera Research: The Current Landscape of Biology, Law, and Public Opinion. Cell Transplant 2023; 32:9636897231183112. [PMID: 37599386 PMCID: PMC10467371 DOI: 10.1177/09636897231183112] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 05/20/2023] [Accepted: 06/04/2023] [Indexed: 08/22/2023] Open
Abstract
Organ transplantation is a highly utilized treatment for many medical conditions, yet the number of patients waiting for organs far exceeds the number available. The challenges and limitations currently associated with organ transplantation and technological advances in gene editing techniques have led scientists to pursue alternate solutions to the donor organ shortage. Growing human organs in animals and harvesting those organs for transplantation into humans is one such solution. These chimeric animals usually have certain genes necessary for a specific organ's development inhibited at an early developmental stage, followed by the addition of cultured pluripotent human cells to fill that developmental niche. The result is a chimeric animal that contains human organs which are available for transplant into a patient, circumventing some of the limitations currently involved in donor organ transplantation. In this review, we will discuss both the current scientific and legal landscape of human-animal chimera (HAC) research. We present an overview of the technological advances that allow for the creation of HACs, the patents that currently exist on these methods, as well as current public attitude and understanding that can influence HAC research policy. We complement our scientific and public attitude discussion with a regulatory overview of chimera research at both the national and state level, while also contrasting current U.S. legislation with regulations in other countries. Overall, we provide a comprehensive analysis of the legal and scientific barriers to conducting research on HACs for the generation of transplantable human organs, as well as provide recommendations for the future.
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Affiliation(s)
- Jennifer L. Brown
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Law School, University of Minnesota, Minneapolis, MN, USA
| | - Joseph P. Voth
- Department of Neuroscience, University of Washington, Seattle, WA, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA, USA
| | - Kennedy Person
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
| | - Walter C. Low
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA
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Garry MG, Caplan AL, Garry DJ. Emerging technologies and ethics-exogenic chimeric humanized organs. Am J Transplant 2022; 22:2786-2790. [PMID: 36052557 PMCID: PMC10087366 DOI: 10.1111/ajt.17188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 08/08/2022] [Accepted: 08/25/2022] [Indexed: 01/25/2023]
Abstract
Organ transplantation is limited due to the scarcity of donor organs. In order to expand the supply of organs for transplantation, interspecies chimeras have been examined as a potential future source of humanized organs. Recent studies using gene editing technologies in combination with somatic cell nuclear transfer technology and hiPSCs successfully engineered humanized skeletal muscle in the porcine embryo. As these technologies progress, there are ethical issues that warrant consideration and dialogue.
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Affiliation(s)
- Mary G Garry
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, USA.,Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA.,Regenerative Medicine and Sciences Program, University of Minnesota, Minneapolis, Minnesota, USA.,NorthStar Genomics, LLC, Eagan, Minnesota, USA
| | - Arthur L Caplan
- Division of Medical Ethics, New York University Langone Medical Center, New York, New York, USA
| | - Daniel J Garry
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, USA.,Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA.,Regenerative Medicine and Sciences Program, University of Minnesota, Minneapolis, Minnesota, USA.,NorthStar Genomics, LLC, Eagan, Minnesota, USA
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Huang HJ, Lee YH, Chou CL, Zheng CM, Chiu HW. Investigation of potential descriptors of chemical compounds on prevention of nephrotoxicity via QSAR approach. Comput Struct Biotechnol J 2022; 20:1876-1884. [PMID: 35521549 PMCID: PMC9052077 DOI: 10.1016/j.csbj.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/02/2022] [Accepted: 04/11/2022] [Indexed: 11/15/2022] Open
Abstract
Drug-induced nephrotoxicity remains a common problem after exposure to medications and diagnostic agents, which may be heightened in the kidney microenvironment and deteriorate kidney function. In this study, the toxic effects of fourteen marked drugs with the individual chemical structure were evaluated in kidney cells. The quantitative structure–activity relationship (QSAR) approach was employed to investigate the potential structural descriptors of each drug-related to their toxic effects. The most reasonable equation of the QSAR model displayed that the estimated regression coefficients such as the number of ring assemblies, three-membered rings, and six-membered rings were strongly related to toxic effects on renal cells. Meanwhile, the chemical properties of the tested compounds including carbon atoms, bridge bonds, H-bond donors, negative atoms, and rotatable bonds were favored properties and promote the toxic effects on renal cells. Particularly, more numbers of rotatable bonds were positively correlated with strong toxic effects that displayed on the most toxic compound. The useful information discovered from our regression QSAR models may help to identify potential hazardous moiety to avoid nephrotoxicity in renal preventive medicine.
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Sluyter R, Watson D. Use of Humanized Mouse Models to Investigate the Roles of Purinergic Signaling in Inflammation and Immunity. Front Pharmacol 2020; 11:596357. [PMID: 33123018 PMCID: PMC7566314 DOI: 10.3389/fphar.2020.596357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 09/18/2020] [Indexed: 12/31/2022] Open
Affiliation(s)
- Ronald Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Debbie Watson
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
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