This article reviews and discusses emerging evidence suggesting an evolutionarily‐conserved connection between injury‐associated exposure of cytoskeletal proteins and the induction of tolerance to infection, repair of tissue damage and restoration of homeostasis. While differences exist between vertebrates and invertebrates with respect to the receptor(s), cell types, and effector mechanisms involved, the response to exposed cytoskeletal proteins appears to be protective and to rely on a conserved signaling cassette involving Src family kinases, the nonreceptor tyrosine kinase Syk, and tyrosine (...) phosphatases. A case is made for research programs that integrate different model organisms in order to increase the understanding of this putative response to tissue damage. (shrink)

Regenerative medicine promises to greatly impact on human health by improving repair outcomes in a range of tissues and injury contexts. Successful therapies will rely on identifying both intrinsic and extrinsic biological circuits that control wound healing, proliferation, cell survival, and developmental cell fate. Animals such as the zebrafish and the salamander display powerful examples of near‐perfect regeneration and scar‐free healing in a range of injury contexts not attained in mammals. By studying regeneration in a range of highly regenerative (...) species that maintain regenerative potential throughout life, many instructive and permissive factors have been identified that could assist in the development of regenerative therapies. This review highlights some of the recent observations in immune regulation, epigenetic regulation, stem cell mobilization, and regenerative signatures that have improved our understanding of the regenerative process. Potential opportunities in harnessing this knowledge for future translation into the clinic are discussed. (shrink)

Stem cells isolated from adult mammalian tissues may provide new approaches for the autologous treatment of disease and tissue repair. Although the potential of adult stem cells has received much attention, it has also recently been brought into question. This article reviews the recent work describing the ability of non‐hematopoietic stem cells derived from adult bone marrow to form neural derivatives and their potential for brain repair. Earlier transplantation experiments imply that grafted adult stem cells can differentiate (...) into neural derivatives. Recent reports suggest, however, that such findings may be misleading and grafted cells acquiring different identities may merely be explained by their fusion with host cells and not the result of radical changes to their program of cellular differentiation. Nonetheless, in vitro studies have shown that neural development by bone‐marrow‐derived stem cells also appears possible. Understanding the molecular mechanisms that specify the neural lineage will lead to the development of tools for the targeted production of neural cell types in vitro that may ultimately provide a source of material to treat specific neurological deficits. BioEssays 24:708–713, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Most tissues contain cells capable of the self‐renewal and differentiation necessary to maintain tissue and organ integrity. These somatic stem cells are generally thought to have limited developmental potential. The mechanisms that restrict cell fate decisions in somatic stem cells are only now being understood. This understanding will be important in the clinical exploitation of adult stem cells in tissue repair and replacement. Experiments performed over fifty years ago in Drosophila showed that developmental restriction could be relaxed (...) in the proliferating larval cells that are destined to form the adult fly integument. This phenomenon, called transdetermination, can serve as a model for mechanisms of stem‐cell commitment. A recent publication1 sheds new light on the mechanism of transdetermination by demonstrating that loss of homeotic gene silencing leads to increased frequency of transdetermination. In addition, the authors link a specific signaling pathway induced by tissue regeneration to the relaxation of homeotic gene silencing. The data identify key mechanisms that control developmental homeostasis and cell fate restriction that could be manipulated to make somatic stem‐cell engineering possible. BioEssays 28: 574–577, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

The work of Sinden et al. suggests that it may be possible to produce improvement in the areas of brain function by transplanting brain tissue. What appears to be the limiting factor is not the complexity of the mental process under consideration but the discreteness of the lesion which causes the impairment and the appropriateness and accuracy of placement of the grafted tissue.

Oncofertility is one of the 9 NIH Roadmap Initiatives, federal grants intended to explore previously intractable questions, and it describes a new field that exists in the liminal space between cancer treatment and its sequelae, IVF clinics and their yearning, and basic research in cell growth, biomaterials, and reproductive science and its tempting promises. Cancer diagnoses, which were once thought universally fatal, now often entail management of a chronic disease. Yet the therapies are rigorous, must start immediately, and in many (...) cases result in premature failure of the body's reproductive ability. In women, this loss is especially poignant; unlike the routine storage of sperm, which is done in men and boys facing similar treatment decisions, freezing oocytes in anticipation of fertility loss is not possible in most cases, and creating an embryo within days of diagnosis raises significant moral, social and medical challenges. Oncofertility is the study of how to harvest ovarian tissue in women facing cancer to preserve their gametes for future use with IVF, thus allowing the decisions about childbearing to be deferred and reproductive choices to be preserved. The research endeavor uses the capacity of the ovarian follicle to produce eggs in vitro . Developing the human follicle to ovulate successfully outside the body is scientifically difficult and ethically challenging. Infertility is linked to long-standing religious and moral traditions, and is intertwined with deeply contentious social narratives about women, families, illness and birth. Is the research morally permissible? Perhaps imperative if understood as a repair from iatrogenic harms? How are considerations of justice central to the work? How will vulnerable subjects be protected? What are the moral implications of the work for women, children and families? What are the implications for society if women could store ovarian tissue as a way of stopping the biological clock? What are the moral possibilities and challenges if eggs can be produced in large quantities from a stored ovarian tissue? (shrink)

It has recently been shown that stem and progenitor cells undergo population self‐renewal to maintain epithelial homeostasis. The fate of individual cells is stochastic but the production of proliferating and differentiating cells is balanced across the population. This new paradigm, originating in mouse epidermis and since extended to mouse oesophagus and mouse and Drosophila intestine, is in contrast to the long held model of epithelial maintenance by exclusively asymmetric division of stem cells. Recent lineage tracing studies have now shown that (...) wound responses vary between tissues, and that a stem cell reserve is not essential as cycling progenitors and even differentiating cells contribute to regeneration. (shrink)

Mesenchymal stem cells (MSCs) are present in fat tissues throughout the body, yet little is known regarding their biological role within epidural fat. We hypothesize that debridement of epidural fat and/or subsequent loss of MSCs within this tissue, disrupts homeostasis in the vertebral environment resulting in increased inflammation, fibrosis, and decreased neovascularization leading to poorer functional outcomes post‐injury/operatively. Clinically, epidural fat is commonly considered a space‐filling tissue with limited functionality and therefore typically discarded during surgery. However, the presence (...) of MSCs within epidural fat suggests that itis more biologically active than historically believed and may contribute to the regulation of homeostasis and regeneration in the dural environment. While the current literature supports our hypothesis, it will require additional experimentation to determine if epidural fat is an endogenous driver of repair and regeneration and if so, this tissue should be minimally perturbed from its original location in the spinal canal. Also see the video abstract here https://youtu.be/MIol_IWK1os. (shrink)

Combining human embryonic stem cells with SCNT has been a gold standard of stem cell research. Adding a particular individual's genes to pluripotent stem cells might lead to the development of personalized tissue repair or replacement. Enthusiasm for human embryonic stem cell research had flagged in recent years due to controversy over the moral status of in vitro embryos, scientific misconduct by researcher Woo Suk Hwang, and the discovery that induced pluripotent stem cells could be produced from somatic (...) cells. Energy shifted to research on somatic cells, but three successes in the United States during 2013 and 2014 may reinvigorate embryonic stem cell research. (shrink)

Cells can transit between a range of stable epithelial and mesenchymal states and this has allowed the evolution of complex body forms. Epithelial to mesenchymal transition (EMT) and its reverse, mesenchymal to epithelial transition (MET), occur sequentially in development and organogenesis. EMT often accompanies transitions between stem‐like cells and their more differentiated progeny, as occurs at gastrulation, although the relevance of this had not been clarified. New findings from the cancer and cell reprogramming fields suggest that EMT and MET can (...) act as essential portals to stem cell character. Here, we review these findings in the broader context of EMT and MET with emphasis on stem cell biology. Using the heart as an example, we also explore the potential role of EMT/MET in organ regeneration. Understanding EMT and MET at a network level will give us new tools to probe stem cell character and enhance tissue repair. (shrink)

Resident microorganisms, known as the microbiota, are essential for many physiological functions including protection against pathogens. Microbiota is indeed required for proper immune system development and function, and can also host-independently protect against infections. Thus, a co-constructed view of host protection involving both host and microbiota, named ’co-immunity,’ has been proposed, and the idea of an ’immunological holobiont’ has been suggested. Yet this view of co-immunity might be too limited, as experimental work has shown that the immune system is involved (...) in functions other than protection, essentially development and repair. Microbiota, through co-immunity, is thereby most likely involved in these functions, although strong evidence is currently lacking. Moreover, as our point of view is mainly host-centered, we may miss the implications of co-immunity at broader scales, including cellular and population levels. Intriguingly, co-immunity effects could be beneficial for one function and/or one level, while being detrimental for others. All these elements should be taken into consideration for microbiota manipulation, in order to avoid potentially harmful side effects. (shrink)

Collective migration is a key process that is critical during development, as well as in physiological and pathophysiological processes including tissue repair, wound healing and cancer. Studies in genetic model organisms have made important contributions to our current understanding of the mechanisms that shape cells into different tissues during morphogenesis. Recent advances in high‐resolution and live‐cell‐imaging techniques provided new insights into the social behavior of cells based on careful visual observations within the context of a living tissue. (...) In this review, we will compare Drosophila testis nascent myotube migration with established in vivo model systems, elucidate similarities, new features and principles in collective cell migration. (shrink)

The growth factor progranulin (PGRN) regulates cell division, survival, and migration. PGRN is an extracellular glycoprotein bearing multiple copies of the cysteine‐rich granulin motif. With PGRN family members in plants and slime mold, it represents one of the most ancient of the extracellular regulatory proteins still extant in modern animals. PRGN has multiple biological roles. It contributes to the regulation of early embryogenesis, to adult tissue repair and inflammation. Elevated PGRN levels often occur in cancers, and PGRN immunotherapy (...) inhibits the growth of hepatic cancer xenografts in mice. Recent studies have demonstrated roles for PGRN in neurobiology. An autosomal dominant mutation in GRN, the gene for PGRN, leads to neuronal atrophy in the frontal and temporal lobes, resulting in the disease frontotemporal lobar dementia. In this review we will discuss current knowledge of the multifaceted biology of PGRN. (shrink)

Receptor oligomerization plays a key role in maintaining genome stability and restricting protein mutagenesis. When properly folded, protein monomers assemble as oligomeric receptors and interact with environmental ligands. In a gene-centered view, the ligand specificity expressed by these receptors is assumed to be causally predetermined by the cell genome. However, this mechanism does not fully explain how differentiated cells have come to express specific receptor repertoires and which combinatorial codes have been explored to activate their associated signaling pathways. It is (...) our contention that the plasma membrane acts as the locus where several contextual cues may be integrated. As such it allows the semiotic selection of those receptor configurations that provide cells with the minimum essential requirements for agency. The occurrence of protein misfolding makes it impossible for receptor monomers to assemble along the membrane and to sustain meaningful relationships with environmental ligands. How could a cell lineage deal with these loss-of-function mutations during evolution and restrain gene redundancy accordingly? In this paper, we will be arguing that the easiest way for bacteria clones to accomplish this goal is by getting rid of cells expressing mutated receptor proteins. The mechanism sustaining this cell selection is also occurring in many somatic tissues and its function is currently believed to counteract in vivo protein mutagenesis. Our discussion will be mainly focused on the significance and semiotic nature of the interplay between membrane receptors and the epigenetic control of gene expression, as mediated by the control of mismatched repairing and protein folding mechanisms. (shrink)

Platelets have important hemostatic functions in repairing blood vessels upon tissue injury. Cytokines, growth factors, and metabolites stored in platelet α‐granules and dense granules are released upon platelet activation and clotting. Emerging evidence indicates that such platelet‐derived signaling factors are instrumental in guiding tissue regeneration. Here, we discuss the important roles of platelet‐secreted signaling factors in skeletal muscle regeneration. Chemokines secreted by platelets in the early phase after injury are needed to recruit neutrophils to injured muscles, and impeding (...) this early step of muscle regeneration exacerbates inflammation at later stages, compromises neo‐angiogenesis and the growth of newly formed myofibers, and reduces post‐injury muscle force production. Platelets also contribute to the recruitment of pro‐regenerative stromal cells from the adipose tissue, and the platelet releasate may also regulate the metabolism and proliferation of muscle satellite cells, which sustain myogenesis. Therefore, harnessing the signaling functions of platelets and the platelet secretome may provide new avenues for promoting skeletal muscle regeneration in health and disease. (shrink)

Genomes are inherently unstable because of the need for DNA sequence variation as a substrate for evolution through natural selection. However, most multicellular organisms have postmitotic tissues, with limited opportunity for selective removal of cells harboring persistent damage and deleterious mutations, which can therefore contribute to functional decline, disease, and death. Key in this process is the role of genome maintenance, the network of protein products that repair DNA damage and signal DNA damage response pathways. Genome maintenance is beneficial (...) early in life by swiftly eliminating DNA damage or damaged cells, facilitating rapid cell proliferation. However, at later ages accumulation of unrepaired damage and mutations, as well as ongoing cell depletion, promotes cancer, atrophy, and other deleterious effects associated with aging. As such, genome maintenance and its phenotypic sequelae provide yet another example of antagonistic pleiotropy in aging and longevity. (shrink)

The subject of biomaterials science concerns artificial materials used in medical devices to repair or reconstruct natural human tissue damaged by disease or trauma. It embraces the emerging field of tissue engineering, where artificial materials are used as scaffolds to provide the architecture for replacement organs. As such, the field raises numerous ethical issues, which are reviewed in this paper. These include the use of animal models, the testing materials and devices in patients, and what may be (...) viewed as potential abuses, where augmentation and repair are carried out for cosmetic as opposed to clinical reasons. The paper gives detailed consideration of the recent problems of metal-on-metal hip replacements as an exemplar of some of the key ethical issues that arise in this field. (shrink)

We review recent progress in the stem cell biology of the respiratory system, and discuss its scientific and translational ramifications. Several studies have defined novel stem cells in postnatal lung and airways and implicated their roles in tissue homeostasis and repair. In addition, significant advances in the generation of respiratory epithelium from pluripotent stem cells (PSCs) now provide a novel and powerful platform for understanding lung development, modeling pulmonary diseases, and implementing drug screening. Finally, breakthroughs have been made (...) in the generation of decellularized lung matrices that can serve as a scaffold for repopulation with respiratory cells derived from either postnatal or PSCs. These studies are a critical step forward towards the still distant goal of stem cell‐based regenerative medicine for diseases of lung and airways. (shrink)

The application of in vivo genetic lineage tracing has advanced our understanding of cellular mechanisms for tissue renewal in organs with slow turnover, like the lung. These studies have identified an adult stem cell with very different properties than classically understood ones that maintain continuously cycling tissues such as the intestine. A portrait has emerged of an ensemble of cellular programs that replenish the cells that line the gas exchange (alveolar) surface, enabling a response tailored to the extent of (...) cell loss. A capacity for differentiated cells to undergo direct lineage transitions allows for local restoration of proper cell balance at sites of injury. We present these recent findings as a paradigm for how a relatively quiescent tissue compartment can maintain homeostasis throughout a lifetime punctuated by injuries ranging from mild to life‐threatening, and discuss how dysfunction or insufficiency of alveolar repair programs produce serious health consequences like cancer and fibrosis. (shrink)

Oxidised bases, such as 8-oxo-guanine, occur in cellular DNA as a result of attack by oxygen free radicals. The cancer-protective effect of vegetables and fruit is attributed to the ability of antioxidants in them to scavenge free radicals, preventing DNA damage and subsequent mutation. Antioxidant supplements (e.g., β-carotene, vitamin C) increase the resistance of lymphocytes to oxidative damage, and a negative correlation is seen between antioxidant concentrations in tissues and oxidised bases in DNA. Large-scale intervention trials with β-carotene have, however, (...) led to increases in cancer. Recent measurements of the frequency of oxidised DNA bases indicate that earlier estimates were greatly exaggerated; there may be only a few thousand 8-oxo-guanines per cell. Convincing evidence for mutations resulting from oxidative damage, in tumours or cultured cells, is lacking. It seems that efficient antioxidant defences together with DNA repair maintain a steady-state level of damage representing minimal risk to cell or organism. BioEssays 21:238–246, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Cognitive deficits were produced in rats by different methods of damaging the brain: chronic ingestion of alcohol, causing widespread damage to diffuse cholinergic and aminergic projection systems; lesions (by local injection of the excitotoxins, ibotenate, quisqualate, and AMPA) of the nuclei of origin of the forebrain cholinergic projection system (FCPS), which innervates the neocortex and hippocampal formation; transient cerebral ischaemia, producing focal damage especially in the CA1 pyramidal cells of the dorsal hippocampus; and lesions (by local injection of the neurotoxin, (...) colchicine) of the granule cells of the dentate gyrus. Following chronic alcohol or lesions of the FCPS, transplants of cholinergically rich fetal brain tissue into the terminal areas (neocortex and/or hippocampus) restored performance almost to control levels, with a time course consistent with growth of the transplants and integration with host tissue; transplants of cholinergically poor fetal tissue (hippocampus) were without effect, as were transplants of cholinergically rich tissue into the region containing the nuclei of origin of the FCPS. Grafts of primary cells enriched in glia and cultured neuroblastoma cells into the terminal areas of the FCPS were equally effective, suggesting that there are multiple mechanisms by which neural transplants can restore cognitive function following diffuse cholinergic damage. In contrast, after ischaemia- or neurotoxin-induced damage to CA1 or dentate granule cells respectively, cholinergically rich fetal transplants into the damaged hippocampal formation were ineffective in restoring performance. After ischaemic damage, however, performance was restored by suspension grafts of CA1 cells but not by transplants containing CA3 pyramidal cells or granule cells; and after colchicine damage it was restored by solid grafts containing granule but not CA1 pyramidal cells. Furthermore, electrophysiological evidence has demonstrated functional, graft type-specific host-graft functional neuronal connectivity. Thus, restoration of cognitive function by neural transplants is possible after damage to either diffuse (cholinergic) or point-to-point (intrahippocampal) forebrain systems, but the transplant must be appropriate to the damage to be repaired. Because the different types of brain damage studied provide analogues of human alcoholic dementia, Alzheimer's disease, and heart attack, these results are encouraging with regard to the eventual application of neural transplant surgery to the treatment of cognitive deficits in humans. (shrink)

Recently, a friend of one of these writers told her story of using one of a healthcare product to activate her stem cells as part of regenerative medicine. Regenerative medicine is a field of medicine that seeks to repair or replace damaged or diseased tissues and organs. This can be done through a variety of methods, including stem cell therapy, tissue engineering, and gene therapy. This is a short review article on this rapid field called regenerative medicine, in (...) particular via a new method called photobiomodulation, especially by virtue of low-intensity laser pen treatment. Hopefully it will attract more research in this interesting direction, both for laser/photobiomodulation to boost plant growth as well as in healthcare (see also: Christianto & Smarandache, 2022; Christianto, 2023). (shrink)

In the United States today, the human body defines a lucrative site of reusable parts, ranging from whole organs to minuscule and even microscopic tissues. Although the medical practices that enable the transfer of parts from one body to another most certainly relieve suffering and extend lives, they have also irrevocably altered perceptions of the cultural values assigned to the body. Organ transfer is rich terrain to investigate—especially in the American context, where sophisticated technological interventions have significantly shaped understandings of (...) health and well-being, suffering, and death. In _Bodies, Commodities, and Biotechnologies_, Lesley Sharp probes the ideological assumptions underlying the transfer of body parts, the social significance of donors' deaths, and the medico-scientific desires surrounding complex forms of body repair. Sharp also considers the experimental realm, in which nonhuman species and artificial devices present further opportunities for recovery and for controversy. A compelling scientific investigation and social critique, _Bodies, Commodities, and Biotechnologies_ explores the pervasive, and at times pernicious, practices shaping American biomedicine in the twenty-first century. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Alzheimer's Disease, Mild Cognitive Impairment, and the Biology of Intrinsic AgingThomas B. L. Kirkwood (bio)Keywordsaging, Alzheimer’s disease, genetic mutation, mild cognitive impairment, telomereThe article by Gaines and Whitehouse (2006) raises key questions about the uncertain relationship between (i) the intrinsic, "normal" aging process, and (ii) the clinicopathologic states represented by the labels of Alzheimer's disease (AD) and mild cognitive impairment (MCI). This short commentary offers a perspective on this (...) debate that is drawn from a consideration of underlying biological mechanisms.Because age is unquestionably the greatest single risk factor associated with AD and MCI, I begin by asking what we know about the intrinsic processes of aging. The central feature of current understanding of intrinsic aging is that it consists of the gradual, lifelong accumulation of a wide variety of molecular and cellular faults that begins very early in life and eventually leads to overt functional impairments resulting in age-related frailty, disability, and disease (Kirkwood 2005). This is an essentially bottom-up process. A strong consensus has emerged in recent years that there is no active program for aging and that there are no genetic factors that have evolved specifically to cause aging or age-related diseases. Unquestionably, there are genes that influence susceptibility to disease and even length of life, but these genes are genes for maintenance and repair functions, not for aging. It is the limitation in the past evolutionary pressure to invest in greater longevity than was required, within an environment where life was usually truncated by hazards such as starvation, injury, or infection, that means that our maintenance systems—good as they are—are insufficient to keep us going indefinitely. Added to this is the idea that there are probably also genes that program processes that are good for the young organism, but which may in later life have harmful effects. Processes like inflammation and apoptosis, which are seen to occur extensively in aged tissues, including brain, surely evolved to help cope with infection and cellular damage arising earlier in life. That they are called into play in aged tissues is a direct, but secondary, consequence of accumulated damage.With this general framework to understand the intrinsic biology of aging, let us now ask what we might expect a priori for the aging of an organ such [End Page 79] as the brain. Although we cannot pretend complete ignorance of how the brain actually does age, our enquiry can be based entirely on data from other organ systems, so we can develop our predictions about brain aging without prejudice.Aging begins very early during human development, faults accumulating from the first stages of embryonic development. Each time a cell divides, each of the daughter cells is likely to acquire a few new mutations. We know this from the estimates for the error rate in DNA replication and the size of the human genome. It is confirmed by direct evidence that at individual gene loci where mutations have been measured, mutation frequency increases with age (Morley 1998; Vijg 2000). In addition to replication errors, DNA is damaged on a daily basis to a very considerable degree by agents such as reactive oxygen species (free radicals), which are formed as byproducts of normal cellular metabolism. Although most of this damage is corrected by repair, the repair mechanisms themselves are not error free and additional mutations accumulate through this route. If a mutation is lethal to the cell, the cell dies and thus the mutation is eliminated. However, the majority of mutations are nonlethal, either because the mutation is recessive and the cell carries an intact gene copy on the other chromosome, because the gene is not currently required, or because the mutation produces only a delayed deleterious effect. Examples of genes that produce delayed deleterious effects include the genes responsible for familial AD. It is interesting to reflect that on statistical grounds alone, it is almost certain that each of us carries a randomly determined fraction of cells in our brains that bear amyloid precursor protein or presenilin mutations associated with AD. We also carry a heterogeneous array of random mutations that compromise essential cell maintenance functions. How many such... (shrink)

Oncofertility is one of the 9 NIH Roadmap Initiatives, federal grants intended to explore previously intractable questions, and it describes a new field that exists in the liminal space between cancer treatment and its sequelae, IVF clinics and their yearning, and basic research in cell growth, biomaterials, and reproductive science and its tempting promises. Cancer diagnoses, which were once thought universally fatal, now often entail management of a chronic disease. Yet the therapies are rigorous, must start immediately, and in many (...) cases result in premature failure of the body's reproductive ability. In women, this loss is especially poignant; unlike the routine storage of sperm, which is done in men and boys facing similar treatment decisions, freezing oocytes in anticipation of fertility loss is not possible in most cases, and creating an embryo within days of diagnosis raises significant moral, social and medical challenges. Oncofertility is the study of how to harvest ovarian tissue in women facing cancer to preserve their gametes for future use with IVF, thus allowing the decisions about childbearing to be deferred and reproductive choices to be preserved. The research endeavor uses the capacity of the ovarian follicle to produce eggs in vitro. Developing the human follicle to ovulate successfully outside the body is scientifically difficult and ethically challenging. Infertility is linked to long-standing religious and moral traditions, and is intertwined with deeply contentious social narratives about women, families, illness and birth. Is the research morally permissible? Perhaps imperative if understood as a repair from iatrogenic harms? How are considerations of justice central to the work? How will vulnerable subjects be protected? What are the moral implications of the work for women, children and families? What are the implications for society if women could store ovarian tissue as a way of stopping the biological clock? What are the moral possibilities and challenges if eggs can be produced in large quantities from a stored ovarian tissue? (shrink)

Ageing causes progressive decline in metabolic, behavioural, and physiological functions, leading to a reduced health span. The extracellular matrix (ECM) is the three‐dimensional network of macromolecules that provides our tissues with structure and biomechanical resilience. Imbalance between damage and repair/regeneration causes the ECM to undergo structural deterioration with age, contributing to age‐associated pathology. The ECM ‘Ageing Across the Life Course’ interdisciplinary research network (ECMage) was established to bring together researchers in the United Kingdom, and internationally, working on the emerging (...) field of ECM ageing. Here we report on a consultation at a joint meeting of ECMage and the Medical Research Council / Versus Arthritis Centre for Integrated Research into Musculoskeletal Ageing, held in January 2023, in which delegates analysed the key questions and research opportunities in the field of ECM ageing. We examine fundamental biological questions, enabling technologies, systems of study and emerging in vitro and in silico models, alongside consideration of the broader challenges facing the field. (shrink)

In the United States today, the human body defines a lucrative site of reusable parts, ranging from whole organs to minuscule and even microscopic tissues. Although the medical practices that enable the transfer of parts from one body to another most certainly relieve suffering and extend lives, they have also irrevocably altered perceptions of the cultural values assigned to the body. Organ transfer is rich terrain to investigate—especially in the American context, where sophisticated technological interventions have significantly shaped understandings of (...) health and well-being, suffering, and death. In _Bodies, Commodities, and Biotechnologies_, Lesley Sharp probes the ideological assumptions underlying the transfer of body parts, the social significance of donors' deaths, and the medico-scientific desires surrounding complex forms of body repair. Sharp also considers the experimental realm, in which nonhuman species and artificial devices present further opportunities for recovery and for controversy. A compelling scientific investigation and social critique, _Bodies, Commodities, and Biotechnologies_ explores the pervasive, and at times pernicious, practices shaping American biomedicine in the twenty-first century. (shrink)

According to recent news reports, developments in biotechnology promise to transform our bodies and our lives. Stem cell research and cloning research are reported to offer us the prospect of being able to grow `spare' body parts and to replace diseased or damaged tissue, implying that there are no natural limits to life, and that the body-machine may be endlessly repaired, and even replicated. The birth of a cloned sheep, Dolly, announced in February 1997, is seen as a milestone (...) development in this regard, suggesting that it is possible to defy `nature' by `turning back the biological clock'. While the development was heralded by many as pointing to new medical therapies, it also served to fuel widespread fears that the technology would soon be applied to cloning humans. This article explores how the news media `framed' issues on human cloning in the aftermath of the announcement of Dolly and thus may have heightened public concerns about its implications, particularly for `individuality' or `identity'. It draws on articles appearing in Australian newspapers, beginning with the initial stories on Dolly through to May 1999, when it was reported that Dolly had shown signs of premature ageing. The article highlights the role of the media in shaping public debate on biotechnology, particularly with regard to its impacts on the body, self and society. (shrink)

During the last decade neurotransplantation has developed into a technique with the possible potential to repair damaged or degenerating human brain. Effective neurotransplantation has so far been based on the use of fetal brain tissue derived from aborted embryos or fetuses. The ethical issues related to this new therapeutic approach therefore not only concern the possible adverse side effects for a neural graft-receiving patient, but also the relationship between the requirements for fetal tissue and the decision-making process (...) for induced abortion. Although for decades human embryos and fetuses have been the subject of biomedical studies, and, in principle, their use has therefore not been seen as ethically objectionable, the above points made it necessary to reconsider the moral issues. The present paper points out several of these issues, both from the donor and acceptor (patient) point of view. The conclusion is that under a series of restrictions intended to prevent the use of grafts from encouraging induced abortions and to maintain high standards of respect for life and human dignity, neurotransplantation using embryonic or fetal brain tissue parts cannot be rejected on moral grounds. (shrink)

: Stem cell research that requires the destruction of human embryos is incompatible with Catholic moral principles, and with any ethic that gives serious weight to the moral status of the human embryo. Moreover, because there are promising and morally acceptable alternative approaches to the repair and regeneration of human tissues, and because treatments that rely on destruction of human embryos would be morally offensive to many patients, embryonic stem cell research may play a far less significant role in (...) medical progress than proponents believe. (shrink)

Inflammatory responses are essential for the clearance of pathogens and the repair of injured tissues; however, if these responses are not properly controlled chronic inflammation can occur. Chronic inflammation is now recognized as a contributing factor to many age‐associated diseases including metabolic disorders, arthritis, neurodegeneration, and cardiovascular disease. Due to the connection between chronic inflammation and these diseases, it is essential to understand underlying mechanisms behind this process. In this review, factors that contribute to chronic inflammation are discussed. Further, (...) we emphasize the emerging roles of microRNAs (miRNAs) and other noncoding RNAs (ncRNA) in regulating chronic inflammatory states, making them important future diagnostic markers and therapeutic targets. Copyright Line: © 2015 The Authors BioEssays Published by Wiley‐VCH Verlag GmbH & Co. KGaA. (shrink)

The Holy Quran and the Sunnah provide the Islamic approach to a complete food system, regulating the consumption of food and drinks, clarifying permissibility and prohibition, to protect human health. This analytical study aimed to explore various categories and benefits of food in Islam derived from plants and animals, focusing specifically on how Islamic Shariah advocates halal food consumption, and what permissions or prohibitions are granted, highlighting the underlying religious evidence and reasoning. The data was collected through both inductive and (...) deductive approaches; the inductive method gathered literature on the topic from the Quran, Sunnah, and Hadith commentaries, while the deductive approach classified plant-based and animal-based foods and elaborated on the benefits of halal items versus the harms of prohibited ones. The study found the plant foods endorsed in Islam include fruits, vegetables, grains, and nuts like dates, beans, olives, and ziziphus, while the permissible animal foods comprise seafood, fish, beef, dairy products, and honey. These foods assist in the growth and repair of body tissues, digestion, energy, metabolism, and overall wellbeing. Meanwhile, prohibited foods contained toxins, germs, and substances that lead to obesity, cancer, blood issues, and more. The implications of this study lie in showcasing how Islam forbids monopoly control of commodities and encourages activities like land rehabilitation for farming and public cultivation. Islam also advises only consuming foods from permitted animals while emphasizing sustenance provisions for milk-producing animals to avoid wastage, as commanded by Allah. (shrink)

Stem cells and the emerging field of regenerative medicine are at the frontiers of modern medicine. These areas of scientific inquiry suggest that in the future, damaged tissue and organs might be repaired through personalized cell therapy as easily as the body repairs itself, revolutionizing the treatment of numerous diseases. Yet the use of stem cells is fraught with ethical and public policy dilemmas that challenge scientists, clinicians, the public health community, and people of good will everywhere. How shall (...) we deal with these amazing biomedical advances, and how can we talk about potential breakthroughs with both moral and scientific intelligence? This book provides an innovative look at these vexing issues through a series of innovative Socratic dialogues that elucidate key scientific and ethical points in an approachable manner. Addressing the cultural and value issues underlying stem cell research while also educating readers about stem cells' biological function and medical applications, _Stem Cell Dialogues_ features fictional characters engaging in compelling inquiry and debate. Participants investigate the scientific, political, and socioethical dimensions of stem cell science using actual language, analysis, and arguments taken from scientific, philosophical, and popular literature. Each dialogue centers on a specific, recognizable topic, such as the policies implemented by the George W. Bush administration restricting the use of embryonic stem cells; the potential role of stem cells in personalized medicine; the ethics of cloning; and the sale of eggs and embryos. Additionally, speakers debate the use of stem cells to treat paralysis, diabetes, stroke effects, macular degeneration, and cancer. Educational, entertaining, and rigorously researched, _Stem Cell Dialogues_ should be included in any effort to help the public understand the science, ethics, and policy concerns of this promising field. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kennedy Institute of Ethics Journal 14.1 (2004) 97-114 [Access article in PDF] Stem Cell Research in the U.S. after the President's Speech of August 2001 Cynthia B. Cohen On 9 August 2001, in a nationally televised speech, President Bush addressed the contentious question of whether to provide federal funds for human embryonic stem cell research (White House 2001).1 This research involves taking the primordial cells found in embryos and (...) transforming them into certain specialized cells, such as those of the heart, nerves, and muscles, with the ultimate goal of transferring these cells into patients to repair damaged cells and tissues. In his remarks, the President authorized funding for research only on stem cells already harvested from remaining embryos at in vitro fertilization (IVF) centers as of 9 August 2001, the date of the speech. In a "Fact Sheet" about embryonic stem cell research, he added the ethical requirements that (1) the donors of embryos gave informed consent to the derivation of stem cells from their embryos, (2) the embryos were created solely for reproductive purposes, and (3) no financial inducements were given to the embryo donors. The President also prohibited federally funded research on embryonic stem cells derived from embryos after 9 August 2001, as well as the creation of embryos for research purposes and the cloning of human embryos for both reproductive and research purposes. He did not seek to ban the pursuit of embryonic stem cell research with private funds. "This allows us to explore the promise and potential of stem-cell research without crossing a fundamental moral line by providing taxpayer funding that would sanction or encourage further destruction of embryos," the President stated (White House 2001).The President's speech stirred intense controversy. Many applauded the new policy because it allowed some embryonic stem cell research to proceed, thereby raising hope that treatments might be developed for those suffering from such conditions as Parkinson's disease, Alzheimer's disease, and diabetes. Others supported it on grounds that it would discourage the future destruction of embryos in stem cell research. They maintained that although it was wrong to have derived stem cells from embryos, this wrong was no longer remediable and it therefore was justifiable to allow research using such embryos to proceed. Some, however, objected to the new policy because they held that it unduly limited the [End Page 97] number of embryonic stem cells available for federally funded research. Still others opposed it on grounds that it made the federal government complicit in what they took to be the wrongful destruction of human embryos that had taken place prior to 9 August 2001. The President established the President's Council on Bioethics by executive order in November 2001 and charged it, among other tasks, with monitoring stem cell research and recommending guidelines and regulations for biomedical innovations.Questions about the moral status of human embryos have so captured public attention since the President issued his remarks that other significant ethical and policy issues raised about stem cell research inside the Beltway have remained in the shadows. A number of individuals and organizations—legislators, scientists, patient groups, the President's Council on Bioethics, ethicists, religious task forces, and social commentators—have attempted to bring these other issues to legislative and public attention. They also have revisited the more publicly prominent question of what sorts of protections we owe to human embryos. In response, Congress has attempted to address several of these newly emerging issues at hearings and in legislation. I review these efforts, consider developing issues and arguments, and conclude by exploring possible future directions for federal and private sector stem cell policy. The Availability of Embryonic Stem Cell Lines to Federally Funded Researchers President Bush, in developing his stem cell research policy, accepted a distinction between the "derivation" and the "use" of embryos enunciated by the General Counsel of the Department of Health and Human Services toward the end of the Clinton administration. This distinction was adopted to avoid contravening the Dickey-Wicker Amendment (added... (shrink)

Bromodomain‐containing 4 (BRD4), a member of Bromo and Extra‐Terminal (BET) family, recognizes acetylated histones and is of importance in transcription, replication, and DNA repair. It also binds non‐histone proteins, DNA and RNA, contributing to development, tissue growth, and various physiological processes. Additionally, BRD4 has been implicated in driving diverse diseases, ranging from cancer, viral infection, inflammation to neurological disorders. Inhibiting its functions with BET inhibitors (BETis) suppresses the progression of several types of cancer, creating an impetus for translating (...) these chemicals to the clinic. The diverse roles of BRD4 are largely dependent on its interaction partners in different contexts. In this review we discuss the molecular mechanisms of BRD4 with its interacting partners in physiology and pathology. Current development of BETis is also summarized. Further understanding the functions of BRD4 and its partners will facilitate resolving the liabilities of present BETis and accelerate their clinical translation. (shrink)

Oxidised bases, such as 8-oxo-guanine, occur in cellular DNA as a result of attack by oxygen free radicals. The cancer-protective effect of vegetables and fruit is attributed to the ability of antioxidants in them to scavenge free radicals, preventing DNA damage and subsequent mutation. Antioxidant supplements (e.g., β-carotene, vitamin C) increase the resistance of lymphocytes to oxidative damage, and a negative correlation is seen between antioxidant concentrations in tissues and oxidised bases in DNA. Large-scale intervention trials with β-carotene have, however, (...) led to increases in cancer. Recent measurements of the frequency of oxidised DNA bases indicate that earlier estimates were greatly exaggerated; there may be only a few thousand 8-oxo-guanines per cell. Convincing evidence for mutations resulting from oxidative damage, in tumours or cultured cells, is lacking. It seems that efficient antioxidant defences together with DNA repair maintain a steady-state level of damage representing minimal risk to cell or organism. BioEssays 21:238–246, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Phagocytosis is the process of recognition and engulfment of microorganisms or tissue debris that accumulate during infection, inflammation or wound repair. This ingestion, which is performed most efficiently by migrating, bone marrow‐derived cells called ‘professional phagocytes’, is essential for successful host defense. Ingestion results when an invading microorganism is recognized by specific receptors on the phagocyte surface and requires multiple, successive interactions between the phagocyte and the target. Each of these interactions results in a signal transduction event, which (...) is confined to the membrane and cytoskeleton around the ligated receptor and which is required for successful phagocytosis. Many molecules found at sites of inflammation or infection stimulate phagocytosis, so that efficient ingestion is confined to the site of infection or inflammation, which in turn limits the proinflammatory and tissue‐destructive processes that accompany phagocytosis. This review summarizes current understanding of this critical component of host defense and of its regulation. (shrink)

Cytokines, also referred to as interleukins, are the major orchestrators of host defence processes, and, as such, are involved in insults, repair and restoration of tissue homeostasis. This review summarises recent findings on and emerging models of the biological roles of the double-edged sword interleukin-13 (IL-13), which have been principally obtained from studies in mice that are deficient for IL-13, or its components. IL-13-mediated functions not only contribute to the susceptible phenotype in Leishmania major infection but also seem (...) to play a protective role in chronic leishmaniasis. Moreover, IL-13 plays a key protective role in the expulsion of helminths from the gut while also actively contributing to the pathology in schistosomiasis. In allergic asthma, IL-13 has also been found to be a key factor. Therapeutic administration of an IL-13 inhibitor in mice successfully prevents both the allergic disease phenotype and schistosoma egg-induced lung pathology. If this scenario holds true in humans, we soon may have an efficient drug for treatment of IL-13-mediated diseases. BioEssays 22:646–656, 2000. © 2000 John Wiley & Sons, Inc. (shrink)

This paper aims to bring the epistemic dimensions of stem cell experiments out of the background, and show that they can be critically evaluated. After introducing some basic concepts of stem cell biology, I set out the current “gold standard” for experimental success in that field (§2). I then trace the origin of this standard to a 1988 controversy over blood stem cells (§3). Understanding the outcome of this controversy requires attention to the details of experimental techniques, the organization of (...) epistemic communities, and relations between the two (§4). With its resolution, a standard for experimental success was established for HSC research, which in turn serves as an exemplar for studies of other stem cells. This historical case study reveals a robust standard for experimental success in stem cell biology: to trace processes of development at the single-cell level, in the form of cell lineage hierarchies. Experiments conforming to this standard can be further critically assessed as means to the therapeutic end of stem cell research: use of stem cells to repair human organs and tissues. (shrink)

By their very nature, overseas medical missions (and even domestic medical charities such as free clinics ) are designed to serve vulnerable populations. If these groups were capable of protecting their own interests, they would not need the help of medical volunteers: their medical needs would be met through existing government health programs or by utilizing their own resources. Medical volunteerism thus seems like an unfettered good: a charitable activity provided by well-meaning doctors and nurses who want to give of (...) their time, skills, and resources to help those who would not otherwise be able to take care of their medical needs. In this article, I argue that if medical volunteerism is to be good, however, it must always meet certain basic ethical requirements. These requirements may be (and perhaps often are) overlooked in the rush to organize and carry out short-term medical missions. I illustrate my point with special reference to short-term medical missions designed to provide surgical repair of obstetric vesico-vaginal fistula, a condition in which the tissues that normally separate the bladder from the vagina are destroyed by obstetric trauma, leading to continuous and unremitting incontinence in the affected woman. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kennedy Institute of Ethics Journal 14.1 (2004) 47-54 [Access article in PDF] Ethical Guidelines for Human Embryonic Stem Cell Research*(A Recommended Manuscript) Adopted on 16 October 2001Revised on 20 August 2002 Ethics Committee of the Chinese National Human Genome Center at Shanghai, Shanghai 201203 Human embryonic stem cell (ES) research is a great project in the frontier of biomedical science for the twenty-first century. Be- cause the research involves (...) the use of human embryos, it triggers serious debate on ethical issues. Opponents consider the embryo to be an early form of human life that should be respected and not destroyed. However, the majority of scientists support embryonic stem cell research, believing that it offers good prospects for the treatment of diseases that have remained incurable until now and so will benefit humankind. The Ethics Committee of the Department of Ethical, Legal, and Social Implications of the Chinese National Human Genome Center at Shanghai seriously discussed the ethical debate initiated by embryonic stem cell research. We concluded that we should support the scientists of our country in actively carrying out human embryonic stem cell research for the noble cause of "medicine being a beneficent art." For the healthy and orderly development of human embryonic stem cell research in our country, we put forward the following recommended Ethical Guidelines for Human Embryonic Stem Cell Research as a reference for leaders, administrative departments, and related scientists. Preface Article 1. Human embryonic stem cells are the primitive cells that play the main role in the growth and development of a human body. These [End Page 47] primitive cells have the potential for infinite proliferation, self-renewal, and multi-directional differentiation. If scientists can discover the mechanism of differentiation of human embryonic stem cells, it will be possible to induce differentiation of human embryonic stem cells to form various types of human cells for clinical cell therapy. If human embryonic stem cell research can be integrated with modern biomedical engineering techniques, it also will be possible to make repair and replacement of human tissues and organs a reality. Article 2. There are two ways to classify human embryonic stem cells. One way is to classify them according to their potential for differentiation. There could be three kinds of stem cells: totipotent stem cells, pluripotent stem cells, and unipotent stem cells.A totipotent stem cell has the potential to develop into a whole individual. It can differentiate into the more than 200 cell types in the whole body, construct any tissue or organ of the body, and finally develop into a whole individual. The fertilized egg and the cleavage cells at the very early stage of embryonic development are totipotent stem cells.A pluripotent stem cell has the potential to differentiate into many cell types derived from the three embryonic layers. However, it has lost the capacity to develop into a complete organism.A unipotent stem cell is derived from the further differentiation of the pluripotent stem cell. It can differentiate only into one cell type such as a hematopoietic stem cell, neural stem cell, and others.The other way is to classify human stem cells according to their source. There could be two kinds of human stem cells: embryonic stem cells and tissue stem cells (also called adult stem cells). The former involves experimentation with embryos, which has serious ethical implications. Ethical issues associated with the latter are mainly expressed in the various opinions regarding the allocation of health resources. Article 3. Human embryonic stem cells are the group of cells called the blastocyst inner cell mass during the early stage of embryonic development. They are the main source of totipotent stem cells, and hence the focal and hot point in stem cell research. Studies on the clinical application of embryonic stem cells probably will involve use of the somatic cell nucleus transfer (SCNT) technique, which destroys the early human embryo. At present, the ethical and moral debate is very serious in human embryonic stem cell research regarding whether the research will develop... (shrink)

There is ongoing debate about whether it is ethically acceptable to allow the creation of cloned embryos in order to produce human stem cells. A cloned embryo is created through a process called somatic-cell nuclear transfer, often known as ‘therapeutic’ cloning. The value of stem cells lies in their capacity to become any sort of cell in the human body. This capacity is particularly useful for treating medical conditions where stem cells can be used to repair or replace damaged (...) tissue. The value of a cloned embryo is that the DNA from a person who needs stem cell treatment can be used to create the clone and thereby minimise the likelihood that any inserted stem cells will be rejected. Research on the use of cloned stem cells is in its earliest stage. (shrink)

In recent years, live imaging has been adopted to study stem cells in their native environment at cellular resolution. In the skeletal muscle field, this has led to visualising the initial events of muscle repair in mouse, and the entire regenerative response in zebrafish. Here, we review recent discoveries in this field obtained from live imaging studies. Tracking of tissue resident stem cells, the satellite cells, following injury has captured the morphogenetic dynamics of stem/progenitor cells as they facilitate (...) repair. Asymmetric satellite cell division generated a clonogenic progenitor pool, providing in vivo validation for this mechanism. Furthermore, there is an emerging role of stem/progenitor cell guidance at the injury site by cellular protrusions. This review concludes that live imaging is a critical tool for discovering the distinct processes that occur during regeneration, emphasising the importance of imaging in diverse animal models to capture the entire scope of stem cell functions. (shrink)

Despite decades of research, remaining safety concerns regarding disease transmission, heterotopic tissue formation, and tumorigenicity have kept stem cell‐based therapies largely outside the standard‐of‐care for musculoskeletal medicine. Recent insights into trophic and immune regulatory activities of mesenchymal stem cells (MSCs), although incomplete, have stimulated a plethora of new clinical trials for indications far beyond simply supplying progenitors to replenish or re‐build lost/damaged tissues. Cell banks are being established and cell‐based products are in active clinical trials. Moreover, significant advances have (...) also been made in the field of pluripotent stem cells, in particular the recent development of induced pluripotent stem cells. Their indefinite proliferation potential promises to overcome the limited supply of tissue‐specific cells and adult stem cells. However, substantial hurdles related to their safety must be overcome for these cells to be clinically applicable. (shrink)

Mars 1980. Une série d'entretiens publiés par le Nouvel Observateur fait scandale. Jean-Paul Sartre, un mois avant sa mort, y révoque des pans entiers de son oeuvre, dénigrant la notion d'angoisse et reléguant l'athéisme pour s'intéresser au messianisme juif et à la résurrection des corps. Face à lui, son dernier secrétaire, Benny Lévy. Accusé par Simone de Beauvoir de manipuler Sartre, Benny Lévy offre à l'écrivain une dernière occasion de revisiter son oeuvre.