Brain Transplantation Research Articles

The epistemology of Deep Brain Stimulation and neuronal pathophysiology

Deep Brain Stimulation (DBS) is a remarkable therapy succeeding where all manner of pharmacological manipulations and brain transplants fail. The success of DBS has resurrected the relevance of electrophysiology and dynamics on the order of milliseconds. Despite the remarkable effects of DBS, its mechanisms of action are largely unknown. There has been an expanding catalogue of various neuronal and neural responses to DBS or DBS-like stimulation but no clear conceptual encompassing explanatory scheme has emerged despite the technological prowess and intellectual sophistication of the scientists involved. Something is amiss. If the scientific observations are sound, then why has there not been more progress? The alternative is that it may be the hypotheses that frame the questions are at fault as well as the methods of inference (logic) used to validate the hypotheses. An analysis of the past and current notions of the DBS mechanisms of action is the subject in order to identify the presuppositions (premises) and logical fallacies that may be at fault. The hope is that these problems will be avoided in the future so the DBS can realize its full potential quickly. In this regard, the discussion of the methods of inference and presuppositions that underlie many current notions is no different then a critique of experimental methods common in scientific discussions and consequently, examinations of the epistemology and logic are appropriate. This analysis is in keeping with the growing appreciation among scientists and philosophers of science, the scientific observations (data) to not “speak for themselves” nor is the scientific method self-evidently true and that consideration of the underlying inferential methods is necessary.

In vivo GABA release and kinetics of transgene loss in a GABAergic cell line after long-term transplantation into the rat brain

Ex vivo gene therapy uses modified cells to deliver substances into the brain. Cell line M213-2O CL-4 expresses human glutamate decarboxylase (hGAD67) by means of an Epstein–Barr virus-based plasmid. This cell line releases GABA in response to depolarizing stimuli in vitro, and after brain transplantation it modulates seizures in animal models. It is unclear if the functional effects observed can be attributed to GABA release by the grafted cells and if GABA release, in turn, is related to the kinetics of transgene permanence or loss under long-term transplantation conditions. To address these issues, two experiments were performed. The first one evaluated GABA levels in the vicinity of an intranigral transplant by microdialysis followed by high performance liquid chromatography (HPLC) quantification. GABA levels and GAD activity were higher in rats with 8-week-old transplants than in control animals, but this effect was lost in rats with 12-week-old transplants. The second experiment evaluated the number of copies of the plasmid containing the hGAD67 (GAD1) transgene by real-time PCR after transplantation into the hippocampus at the same times. A time-dependent loss of the plasmid in the transplants was observed. The mechanism of plasmid loss was explored in vitro by analyzing the effects of DNA methylation and the absence of selection pressure. The results suggest that the loss of plasmid copies from transplants under long-term conditions may be related to methylation of plasmid regions involved in its nuclear retention. Taking these data together, we propose that the reported long-term functional effects of transplants of cell line M213-2O CL-4 may not be attributed exclusively to increased GABA release in the area of the graft, but that a paracrine-like action of GABA may lead to the remodeling of neural circuits in the host.

Developing Intuitions about How Personal and Social Properties Are Linked to the Brain and the Body

This study investigated the development of intuitions about which properties are associated with the brain and which are associated with the body. A sample of 60 children aged 6, 8, and 10 years, as well a sample of 20 adults, were told about a brain transplant between two individuals and were asked about where certain properties resided after the transplant. Adults and older children construed the characteristics associated with fine-motor behaviour, culpability, social contract and best friendships as transferring with the brain. Characteristics associated with gross-motor behaviour, physical/biological properties, ownership and familial relationships were more likely to be seen as remaining with the body. Domain-based explanations for this pattern of results are discussed.

What’s stopping you? The contribution of gender essentialism to sex differences in subject choice

The present study considered the impact of gender essentialism on sex differences in subject choice. Secondary school children, aged 11-12 years (N = 30) and 15-16 years (N = 26), were randomly assigned to one of three experimental conditions, and completed a thought experiment requiring them to make inferences about two gendered attributes; academic subject ability and gender-stereotyped properties, of a hypothetical male and female; (a) raised in an opposite sex environment; (b) following a brain transplant from a member of the opposite sex and (c) a 'normal' male or female, acting as a baseline response. Results from the experiment indicated that children do hold essentialist beliefs about gender. However, such beliefs vary as a function of both the age of participants, and the gendered attribute considered. We conclude that gender essentialism may account for the persistence of sex differences in subject choice.

Importance of stoichiometry in cells science: iPSC, CNS leukocytes, and more

the hope of becoming the source and basis of sideeffect–free ‘‘medication’’ and repair of deficits in our body,stem cells have been, for a few decades, of interest in basic cellresearch, regenerative medicine, and public opinion. Cytome-try was from the beginning a guiding technology in thisendeavor. The substantial past and present scientific interest isreflected by the fact that publications on stem cells and theirunequivocal identification are the ‘‘best sellers’’ regarding cita-tion and download rates also in the cytometry-focused litera-ture (1). Nevertheless, stem cell therapy still plays a minor rolein clinical practice. The main stem cell therapy is allogenic orautologous bone marrow transplantation in cancer or insevere life-threatening autoimmune diseases such as rheuma-toid arthritis. This transplantation is either done by crudebone marrow allografting or by using purified (i.e., sorted orotherwise enriched) material.Another far less frequent application is transplantation offetal brain tissue in Parkinson’s disease, rendering (temporary)relief from the symptoms. Fetal brain transplant in Hunting-ton’s disease was far less successful as indicated by clinicaltrials enrolling a limited number of patients. In addition,transplantation of parts of the fetal brain is a continuing issueof ethical concern. One of the reasons for the limited applica-tion of stem cell therapy in regenerative medicine is the limita-tion of appropriate cell sources. Mesenchymal stem cells fromfatty tissue (2), as one example, can be relatively easily har-vested but may be limited in their regenerative abilities.Consequently, the discovery of embryonic pluripotentstem cells has led to both a great deal of activity and hype inresearch for novel cell-based therapies. As ethical issuesinvolved in using embryonic stem cells exist, only a limitednumber of countries equipped with appropriate high-endresearch knowledge and technology can embrace these cells fortherapy development.Therefore, the discovery of inducible pluripotent stemcells (iPSCs)—somatic cells (of in principle any type) that canbe reprogrammed by the transfection of a limited number oftranscription factors to become pluripotent—was an impor-tant breakthrough. By their creative and diligent work, thegroup of Shinya Yamanaka from Kyoto University in Japandiscovered that the transfection of only four genes was suffi-cient to reprogram somatic cells to become iPSCs and formany possible cell type of an organism (3).How to optimize the process of transfection to producemaximum numbers of reprogrammed cells and how to per-form appropriate quality control of yield and cell type remainsa central issue. Tiemann and coworkers from Hannover andM€unster in Germany (this issue, page 426) developed a poly-chromatic flow cytometry approach by attaching each of thefour transfected transcription factors (Oct4, c-Myc, Sox2, andKlf4) to four different fluorescent proteins. Quadruplet posi-tive cells contain the reprogrammed iPSCs that can then besorted and cloned. By testing different stoichiometric combi-nations of these transcription factor expression levels,the authors were able to optimize iPSC yield and quantitateoptimal transcription factor levels.The importance of polychromatic cytometry has beenapplied to identify unusual biological material in the pri-mate brain. Bischoff from the University of G€ottingen,Germany and colleagues (this issue, page 436) focusedtheir interest on cells of the immune system infiltratingthe brain. The quantity and composition of these cells canrender information on inflammation processes in neuro-logical diseases and also in stem cell transplantation,

Crenças essencialistas sobre policiais e delinquentes

O objetivo deste artigo foi descrever crenças esssencialistas em um experimento no paradigma do transplante de cérebro. Participantes brasileiros (101) e espanhóis (138) foram submetidos a um experimento mental de desenho 2 (país) x 2 (direção do transplante). A análise loglinear não evidenciou um claro efeito principal do país, embora tenha identificado uma interação entre o país e o transplante de cérebro. Posteriormente, as justificativas apresentadas pelos participantes foram analisadas e o que evidenciou que as pressões situacionais foram arroladas para explicar a estabilidade da conduta, enquanto as demais fontes explicativas foram adotadas predominantemente para explicar mudanças no comportamento decorrentes do transplante do cérebro. Implicações são discutidas.

Glutamatergic Excitation and GABA Release from a Transplantable Cell Line

The cell line M213-2O CL-4 was derived from cell line M213-2O and further modified to express human glutamate decarboxylase (hGAD-67), the enzyme that synthesizes GABA. Brain transplants of this cell line in animal models of epilepsy have been shown to modulate seizures. However, the mechanisms that underlie such actions are unknown. The purpose of the present study was to characterize this cell line and its responsiveness to several depolarizing conditions, in order to better understand how these cells exert their effects. Intracellular GABA levels were 34-fold higher and GAD activity was 16-fold higher in clone M213-2O CL-4 than in M213-2O. Both cell lines could take up [³H]GABA in vitro, and this uptake was prevented by nipecotic acid. By combining GABA release measurements and calcium imaging in vitro, we found that high extracellular K(+), zero Mg(2+), or glutamate activated M213-2O CL-4 cells and resulted in GABA release. The response to glutamate appeared to be mediated by AMPA/NMDA-like receptors. High KCl-induced GABA release was prevented when a Ca(2+)-free Krebs solution was used, suggesting an exocytotic-like mechanism. These results indicate that the cell line M213-2O CL-4 synthesizes, releases, and takes up GABA in vitro, and can be activated by depolarizing stimuli.

Stem Cells for the Treatment of Neurodegenerative Diseases

Neurodegenerative diseases are characterized by neurodegenerative changes or apoptosis of neurons involved in networks, leading to permanent paralysis and loss of sensation below the site of the injury. Cell replacement therapy has provided the basis for the development of potentially powerful new therapeutic strategies for a broad spectrum of human neurological diseases. In recent years, neurons and glial cells have successfully been generated from stem cells, and extensive efforts by investigators to develop stem cell-based brain transplantation therapies have been carried out. We review here notable previously published experimental and preclinical studies involving stem cell-based cell for neurodegenerative diseases and discuss the future prospects for stem cell therapy of neurological disorders in the clinical setting. Steady and solid progress in stem cell research in both basic and preclinical settings should support the hope for development of stem cell-based cell therapies for neurological diseases.

Human neural stem cells genetically modified to overexpress brain‐derived neurotrophic factor promote functional recovery and neuroprotection in a mouse stroke model

Intracerebral hemorrhage (ICH) is a lethal stroke type; mortality approaches 50%, and current medical therapy against ICH shows only limited effectiveness, so an alternative approach is required, such as stem cell-based cell therapy. Previously we have shown that intravenously transplanted human neural stem cells (NSCs) selectively migrate to the brain and promote functional recovery in rat ICH model, and others have shown that intracerebral infusion of brain-derived neurotrophic factor (BDNF) results in improved structural and functional outcome from cerebral ischemia. We postulated that human NSCs overexpressing BDNF transplanted into cerebral cortex overlying ICH lesion could provide improved survival of grafted NSCs and increased angiogenesis and behavioral recovery in mouse ICH model. ICH was induced in adult mice by injection of bacterial collagenase into striatum. The HB1.F3.BDNF (F3.BDNF) human NSC line produces sixfold higher amounts of BDNFF over the parental F3 cell line in vitro, induces behavioral improvement, and produces a threefold increase in cell survival at 2 weeks and 8 weeks posttransplantation. Brain transplantation of human NSCs overexpressing BDNF provided differentiation and survival of grafted human NSCs and renewed angiogenesis of host brain and functional recovery of ICH animals. These results indicate that the F3.BDNF human NSCs should be of great value as a cellular source for experimental studies involving cellular therapy for human neurological disorders, including ICH.

Virtual brain transplantation (VBT): a method for accurate image registration and parcellation in large cortical stroke.

The objective of the current study was to develop a semi-automated method to register and parcellate lesioned brains in a surface space with anatomical accuracy, facilitating group-level fMRI analyses in patients with large cortical strokes. Thirteen chronic patients with a single large left hemisphere stroke were included in the study. Our "virtual brain transplantation" (VBT) approach is based on pre-processing high resolution anatomical T1-weighted brain images by "filling in" the lesion with "transplanted virtual tissue" from the non-stroke hemisphere, providing "normal" anatomical landmarks for standard alignment and inflation algorithms developed for healthy individuals. Biological validation of the approach was performed by quantifying in Freesurfer space the areas of 12 hand-drawn sulci found inside and outside the stroke following "transplantation". Our results show no difference in the Freesurfer parcellation of 12 different regions when comparing a lesioned hemisphere with the non-lesioned hemisphere, attesting for the validity of the anatomical classification in the stroke hemisphere. As consequence of the anatomical precision, this method permits a more detailed and quantifiable anatomical description of the regions affected directly by the stroke. This method permits accurate surface reconstruction of the injured hemisphere after stroke by making it possible to extract the cortical surface from these images and to utilize this in software modules (FreeSurfer) specialized for aligning cortical surfaces using high-dimensionality warping algorithms. In addition, it permits quantifying, within bounds, the extent to which the lesion in question is associated with damage to particular regions of the cortical surface, information that is of explanatory value in models that attempt to explain brain-behavior relations using lesion analysis.

Angiogenesis, Neurogenesis and Neuroplasticity in Ischemic Stroke

Only very little is know about the neurovascular niche after cardioembolic stroke. Three processes implicated in neurorepair: angiogenesis, neurogenesis and synaptic plasticity, would be naturally produced in adult brains, but also could be stimulated through endogen neurorepair phenomena. Angiogenesis stimulation generates new vessels with the aim to increase collateral circulation. Neurogenesis is controlled by intrinsic genetic mechanisms and growth factors but also ambiental factors are important. The leading process of the migrating neural progenitor cells (NPCs) is closely associated with blood vessels, suggesting that this interaction provides directional guidance to the NPCs. These findings suggest that blood vessels play an important role as a scaffold for NPCs migration toward the damaged brain region. DNA microarray technology and blood genomic profiling in human stroke provided tools to investigate the expression of thousands of genes. Critical comparison of gene expression profiles after stroke in humans with those in animal models should lead to a better understanding of the pathophysiology of brain ischaemia. Probably the most important part of early recovery after stroke is limited capacity of penumbra/infarct neurones to recover. It became more clear in the last years, that penumbra is not just passively dying over time but it is also actively recovering. This initial plasticity in majority contributes towards later neurogenesis, angiogenesis and final recovery. Penumbra is a principal target in acute phase of stroke. Thus, the origin of newly formed vessels and the pathogenic role of neovascularization and neurogenesis are important unresolved issues in our understanding of the mechanisms after stroke. Biomaterials for promoting brain protection, repair and regeneration are new hot target. Recently developed biomaterials can enable and increase the target delivery of drugs or therapeutic proteins to the brain, allow cell or tissue transplants to be effectively delivered to the brain and help to rebuild damaged circuits. These new approaches are gaining clear importance because nanotechnology allows better control over material-cell interactions that induce specific developmental processes and cellular responses including differentiation, migration and outgrowth.

Development of clinically relevant orthotopic xenograft mouse model of metastatic lung cancer and glioblastoma through surgical tumor tissues injection with trocar

ObjectiveOrthotopic models are important in cancer research. Here we developed orthotopic xenograft mouse model of metastatic lung cancer and glioblastoma with a specially designed system.MethodsTiny fragments of surgical tumors were implanted into the mice brain with a trocar system. Immunohistochemistry was performed to detect brain tumor stem cells among glioblastoma tissues, including both the original and resulting ones with monoclonal antibody against CD133.ResultsBesides the constant high take rates in both models; brain transplants perfectly resembled their original tumors in biological behaviors. The brain tumor stem cells, positively stained with CD133 were found, though not frequently, in both original and resulting glioblastoma tissues.ConclusionsOrthotopic model established with a trocar system is effective and injection of tumor tissues containing stem cells promise the forming of new tumor mass when grafted.

Lafleur, William R., Gernot Bohme and Susumu Shimazono, eds. 2007. Dark medicine: Rationalizing unethical medical research

Certain books make you reconsider your views even though you really would rather not. This edited collection is one of those. When I was a child I became enamored of science because I could be both intellectually challenged and do unqualified good. While I was thinking those thoughts and reading every science book I could find, the Germans and Japanese were carrying out their murderous experiments in the name of human research. Dark Medicine illuminates those events with special detail on the Japanese activities in Unit 731, with which we in the West are much less familiar than the Nazi experiments, and asks repeatedly: how did respected physicians of those times and places rationalize their behavior? In each case, the subjects were rendered subhuman (marked for death) and the process was justified by a combination of normalization and intimidation. American researchers, while recognizing the evils of Hitler’s Germany and, in theory, understanding the principles embedded in the Nuremberg Report, carried out numerous unethical research projects involving exposures to radiation and biohazards. In these cases, the research was rationalized by referral to the exigencies of the “Cold War” (the enemy was probably doing the same thing) and normalization of the behavior as standard. Eventually the disgraceful nature of the studies was made apparent. As noted, by referral to Marcus Aurelius, the medical profession was declared “incapable of acting upright on its own” in human research and had to “be kept upright by proliferating laws and policies.” The second half of the book opens with a discussion of iatrogenesis in medicine (Fox) in which harm is done in order to accomplish good, with the obvious example being surgery. The profession proceeds with progressively more invasive procedures until one must ask: “Is the good worth the harm?” and “who really has the right to decide?” Near-lethal chemotherapy and organ transplantation are realms demonstrating great technological achievement, but at what cost in quality of life and dignity? Fox asks: “Does the technological imperative abide by any limits?” The authors ask how normalization of technological development in medicine functions in the realm of dying (Komatsu), and brain death and transplantation (Yamaori). There is a worrisome discussion of eugenics in high tech fertility (Ogino) and use of embryos (Shimazono) as procedures that diminish human dignity in the name of technical progress and heightened national research competitiveness. Comparisons are made between preimplantation and fetal eugenics and Nazi ideas of eugenics. Ogino also discusses the feminist question of whether technological advances liberate women from constraints on desired reproduction or whether they simply represent new and invasive ways of exploiting women’s bodies. She focuses on differing cultural attitudes in different countries and describes the evolution of thought and policies regarding reproductive technologies in Japan. Japanese women are not enthusiastic about use of these techniques for fertility but want to have children with no identifiable imperfections. Interesting, but not necessarily apt comparisons are made between the family dignity inherent in the old way of death in Japan in comparison to the cold, alienating formalized process associated with brain death for organ transplantation. In the final chapter, La Fleur—drawing on Hans Jonas’ work—asks whether the concept of seeking a biologically determined utopia in which we improve the human genome and vanquish many of today’s health problems is actually a desirable end, either for humanity as a whole or for individuals. Utopian thinking implies changes possible mainly in command societies. Someone in charge has to make decisions and see to it that they are implemented. That idea frightens me. To whom would you be willing to entrust such momentous decisions? What would be universally agreed upon changes? This set of powerful essays sheds light on medicine and its practitioners past, present and future and questions the headlong plunge of developed and developing societies into more and more aggressive technological attacks on illness to preserve life itself. It is truly worthwhile reading. We need to think more carefully about where we are headed as a species and we hope that this book is a harbinger of that deep thought as we, in the United States, prepare to address reform of our healthcare system in the setting of accelerating technological capability and burgeoning costs.

A Colloquium on the Congress “A Gift for Life. Considerations on Organ Donation”

Alessandro Nanni Costa, J. M. Simon i Castellvi, Antonio G. Spagnolo, Nunziata Comoretto, Jean Laffitte, Hakan Gabel, Francis L. Delmonico, Ferdinand Muehlbacher, Walter Schaupp, Alexandra K. Glazier, Valter D. Garcia, Mario Abbud-Filho, Jose O. Medina-Pestana, Mariangela Gritta Grainer, Pier Paolo Donadio, Anna Guermani, Riccardo Bosco, Francesco Giordano, Blanca Martinez Lopez de Arroyabe, Marco Brunetti, Marti Manyalich, Gloria Paez, Ricardo Valero, Rafael Matesanz, Elisabeth Coll, Beatriz Dominguez-Gil, Beatriz Mahillo, Eduardo Martin Escobar, Gregorio Garrido, and Felix Cantarovich

Bilateral Interaction Between Cord Blood–Derived Human Neural Stem Cells and Organotypic Rat Hippocampal Culture

The umbilical cord blood-derived neural stem/progenitor cells (HUCB-NSCs) potentially represent a rich source of transplantable material for treatment of a wide range of neurological diseases. Although, recently reported effects of their implementation in animal models of brain pathology are still controversial. As a simplified alternative to in vivo transplantation in this work we have applied a long-term organotypic rat hippocampal slice culture (OHC) as a recipient tissue to study bilateral graft/host cells interactions ex vivo. This type of culture can be considered as a kind of reductionistic model of brain transplantation where direct influence of systemic immunological responses to transplanted human cells would be excluded. The transplantation material derived from a HUCB-NSC line developed and characterized in our laboratory and delivered to the slices either as a single-cell suspension or after formation of typical neurospheres in serum-free medium in vitro (N-HUCBs). Experiments were focused on space-temporal context of cell transplantation in relation to their ability to ingrown, migrate, and differentiate within the slice cytoarchitecture. We gain evidences that these responses are strictly dependent on the engraftment site and that cell movement reflects typical routes used for migratory neuroblasts in vivo. The cells implanted at the second week of slice cultivation ingrown readily and deeply into host cytoarchitecture then matured to the level never observed in our transplantation animal models in vivo. Importantly, transplanted neurospheres, in addition to yield exogenous migratory cells to the host tissue can locally inhibit astrocytosis and promote outgrow of DCX-reactive neuroblasts in the surrounding OHC tissue.

Biomaterials for promoting brain protection, repair and regeneration

Biomaterials are likely to have an increasingly important role in the treatment of nervous system disorders. Recently developed biomaterials can enable and augment the targeted delivery of drugs or therapeutic proteins to the brain, allow cell or tissue transplants to be effectively delivered to the brain and help to rebuild damaged circuits. Similarly, biomaterials are being used to promote regeneration and to repair damaged neuronal pathways in combination with stem cell therapies. Many of these approaches are gaining momentum because nanotechnology allows greater control over material-cell interactions that induce specific developmental processes and cellular responses including differentiation, migration and outgrowth.

Mesenchymal stem cells induce a weak immune response in the rat striatum after allo or xenotransplantation

AbstractMesenchymal stem cells (MSCs) have attracted attention for their potential use in regenerative medicine such as brain transplantation. As MSCs are considered to be hypoimmunogenic, transplanted MSCs should not trigger a strong host inflammatory response. To verify this hypothesis, we studied the brain immune response after transplantation of human or rat MSCs into the rat striatum and MSC fate at days 5, 14, 21 and 63 after transplantation. Flow cytometry analysis indicated that both MSCs express CD90 and human leucocyte antigen (MHC) class I, but no MHC class II molecules. They do not express CD45 or CD34 antigens. However, MSC phenotype varies with passage number. Human MSCs have mRNAs for interleukin (IL)‐6, IL‐8, IL‐12, tumour necrosis factor (TNF)‐α and TGF‐β1, whereas rat MSCs express IL‐6‐, IL‐10‐, IL‐12‐ and TGF‐β1‐mRNAs. The quantification shows higher levels of mRNAs for the anti‐inflammatory molecules IL‐6 and TGF‐β1 than for pro‐inflammatory cytokines IL‐8 and IL‐12; ELISA analysis showed no IL‐12 whereas TGF‐β1 and IL‐6 were detected. Transplant size did not significantly vary between 14 and 63 days after transplantation, indicating an absence of immune rejection of the grafts. Very few mast cells and moderate macrophage and microglial infiltrations, observed at day 5 remained stable until day 63 after transplantation in both rat and human MSC grafts. The observations of very few dendritic cells, T αβ‐cells, and no T γδ‐lymphocytes, all three being associated with Tp rejection in the brain, support the contention that MSCs are hypoimmunogenic. Our results suggest that MSCs are of great interest in regenerative medicine in a (xeno)transplantation setting.

Mesenchymal stem cells induce a weak immune response in the rat striatum after allo or xenotransplantation

Mesenchymal stem cells (MSCs) have attracted attention for their potential use in regenerative medicine such as brain transplantation. As MSCs are considered to be hypoimmunogenic, transplanted MSCs should not trigger a strong host inflammatory response. To verify this hypothesis, we studied the brain immune response after transplantation of human or rat MSCs into the rat striatum and MSC fate at days 5, 14, 21 and 63 after transplantation. Flow cytometry analysis indicated that both MSCs express CD90 and human leucocyte antigen (MHC) class I, but no MHC class II molecules. They do not express CD45 or CD34 antigens. However, MSC phenotype varies with passage number. Human MSCs have mRNAs for interleukin (IL)-6, IL-8, IL-12, tumour necrosis factor (TNF)-alpha and TGF-beta(1), whereas rat MSCs express IL-6-, IL-10-, IL-12- and TGF-beta(1)-mRNAs. The quantification shows higher levels of mRNAs for the anti-inflammatory molecules IL-6 and TGF-beta(1) than for pro-inflammatory cytokines IL-8 and IL-12; ELISA analysis showed no IL-12 whereas TGF-beta(1) and IL-6 were detected. Transplant size did not significantly vary between 14 and 63 days after transplantation, indicating an absence of immune rejection of the grafts. Very few mast cells and moderate macrophage and microglial infiltrations, observed at day 5 remained stable until day 63 after transplantation in both rat and human MSC grafts. The observations of very few dendritic cells, T alphabeta-cells, and no T gammadelta-lymphocytes, all three being associated with Tp rejection in the brain, support the contention that MSCs are hypoimmunogenic. Our results suggest that MSCs are of great interest in regenerative medicine in a (xeno)transplantation setting.

Human neural stem cells overexpressing glial cell line-derived neurotrophic factor in experimental cerebral hemorrhage

Recent studies have reported that glial cell line-derived growth factor (GDNF) has neurotrophic effects on the central nervous system, and the neural stem cells (NSCs) engrafted in animal models of stroke survive and ameliorate the neurological deficits. In this study, a stable human NSC line overexpressing GDNF (F3.GDNF) was transplanted next to the intracerebral hemorrhage (ICH) lesion site and a possible therapeutic effect was investigated. F3.GDNF human NSC line was transplanted into the cortex overlying the striatal ICH lesion. ICH was induced in adult mice by the unilateral injection of bacterial collagenase into the striatum. The animals were evaluated for 8 weeks with rotarod and limb placement tests. Transplanted NSCs were detected by beta-gal immunostaining with double labeling of neurofilament, microtubule associated protein-2, glial fibrillary acidic protein or human nuclear matrix antigen (HuNuMA). F3.GDNF human NSCs produced a four times higher amount of GDNF over parental F3 cells in vitro, induced behavioral improvement in ICH mice after brain transplantation and two- to threefold increase in cell survival of transplanted NSCs at 2 and 8 weeks post-transplantation. In F3.GDNF-grafted ICH brain, a significant increase in the antiapoptotic protein and cell survival signal molecules, and a marked reduction in proapoptotic proteins were found as compared with control group. Brain transplantation of human NSCs overexpressing GDNF in ICH animals provided functional recovery in ICH animals, and survival and differentiation of grafted human NSCs. These results indicate that the F3.GDNF human NSCs should be of a great value as a cellular source for the cellular therapy in animal models of human neurological disorders including ICH.

Problems with a Constitution Account of Persons

ABSTRACT: There are some problems with Lynne Baker’s constitution account of personal identity that become evident when we consider brain transplant thought experiments and two kinds of rare cases of conjoined twins — the first appears to be one organism but two persons and the second seems to involve two organisms associated with one person. To handle the problems arising from brain transplants, the constitution theorist must admit an additional level of constitution between the organism and the person. To resolve the problems posed by the two kinds of conjoined twins, the constitution theorist must accept that constitution is not always a one-to-one relationship.