19 research outputs found

    The Draytons Of Drayton Hall: Land, Kinship Ties And The British Atlantic World

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    In 1675, Thomas Drayton Sr. undertook a voyage across the Atlantic Ocean to the colony of Barbados in search of land and opportunities. He did not find either in Barbados, but his eldest son, Thomas Drayton Jr. immigrated to the new colony of Carolina. Drayton Jr. accumulated a large amount of capital and invested his money in rice cultivation and the importation of slaves. Drayton Jr. married Ann Fox, the daughter of his friend and mentor, Stephen Fox. Their marriage laid the foundation for the Drayton Dynasty in Carolina. Upon the death of Thomas Drayton Sr., his widow Ann became the executrix of his estate and legally became a “feme sole.” Ann Fox Drayton established tight kinship ties to several powerful planter families, who resided on the Ashley River. She taught her son youngest, John Drayton business skills, financial management, and agricultural methods. John Drayton would become one of the wealthiest and powerful planters in the South Carolina Lowcountry. He would construct the most exceptional Georgian-Palladian mansion in British North America. Drayton Hall would come to signify his elevated position in the Charleston plantocracy. Drayton identified with all things English, which he reflected in matters of taste and style. In 1784, Charles Drayton, the second son of John Drayton, assumed ownership of Drayton Hall, when he purchased the plantation from his father’s widow, Rebecca Perry Drayton. Litigation amongst the children and grandchildren over John Drayton’s will would leave him in reduced circumstances. He would redesign Drayton Hall as a “ferme ornee” or ornamental farm, which would grow provisions and livestock and cultivate rice at two outlying plantations on the peripheries of the Lowcountry. When died in 1820, Drayton Hall was his one remaining asset, which he left to his son, Charles II. After 1820, Drayton Hall entered an eclipse. The attempts of the Draytons to cultivate rice in southern Georgia were a failure. The Civil War did not destroy Drayton Hall, but the family was penniless. Phosphate mining at Drayton Hall returned the family to prosperity. In 1973, unable to maintain Drayton Hall, the Drayton family sold it to the National Trust for Historic Preservation

    Application of Human Induced Pluripotent Stem Cell Technology for Cardiovascular Regenerative Pharmacology

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    Cardiovascular diseases are one of the leading causes of mortality in the western world. Myocardial infarction is among the most prevalent and results in significant cell loss within the myocardium. Similarly, numerous drugs have been identified as having cardiotoxic side effects. The adult human heart is however unable to instigate an effective repair mechanism and regenerate the myocardium in response to such damage. This is in large part due to the withdrawal of cardiomyocytes (CMs) from the cell cycle. Thus, identifying, screening, and developing agents that could enhance the proliferative capacity of CMs holds great potential in cardiac regeneration. Human induced pluripotent stem cells (hiPSCs) and their cardiovascular derivatives are excellent tools in the search for such agents. This chapter outlines state-of-the art techniques for the two-dimensional differentiation and attainment of hiPSC-derived CMs and endothelial cells (ECs). Bioreactor systems and three-dimensional spheroids derived from hiPSC-cardiovascular derivatives are explored as platforms for drug discovery before focusing on relevant assays that can be employed to assess cell proliferation and viability.Peer reviewe

    Retinoid Machinery in Distinct Neural Stem Cell Populations with Different Retinoid Responsiveness

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    Retinoic acid (RA) is present at sites of neurogenesis in both the embryonic and adult brain. While it is widely accepted that RA signaling is involved in the regulation of neural stem cell differentiation, little is known about vitamin A utilization and biosynthesis of active retinoids in the neurogenic niches, or about the details of retinoid metabolism in neural stem cells and differentiating progenies. Here we provide data on retinoid responsiveness and RA production of distinct neural stem cell/neural progenitor populations. In addition, we demonstrate differentiation-related changes in the expression of genes encoding proteins of the retinoid machinery, including components responsible for uptake (Stra6) and storage (Lrat) of vitamin A, transport of retinoids (Rbp4, CrbpI, CrabpI-II), synthesis (Rdh10, Raldh1-4), degradation of RA (Cyp26a1-c1) and RA signaling (Raralpha,beta,gamma, Rxralpha,beta,gamma). We show that both early embryonic neuroectodermal (NE-4C) stem cells and late embryonic or adult derived radial glia like progenitors (RGl cells) are capable to produce bioactive retinoids but respond differently to retinoid signals. However, while neuronal differentiation of RGl cells can not be induced by RA, neuron formation by NE-4C cells is initiated by both RA and RA-precursors (retinol or retinyl acetate). The data indicate that endogenous RA production, at least in some neural stem cell populations, may result in autocrine regulation of neuronal differentiation

    Microglia protect against brain injury and their selective elimination dysregulates neuronal network activity after stroke

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    Microglia are the main immune cells of the brain and contribute to common brain diseases. However, it is unclear how microglia influence neuronal activity and survival in the injured brain in vivo. Here we develop a precisely controlled model of brain injury induced by cerebral ischaemia combined with fast in vivo two-photon calcium imaging and selective microglial manipulation. We show that selective elimination of microglia leads to a striking, 60% increase in infarct size, which is reversed by microglial repopulation. Microglia-mediated protection includes reduction of excitotoxic injury, since an absence of microglia leads to dysregulated neuronal calcium responses, calcium overload and increased neuronal death. Furthermore, the incidence of spreading depolarization (SD) is markedly reduced in the absence of microglia. Thus, microglia are involved in changes in neuronal network activity and SD after brain injury in vivo that could have important implications for common brain diseases

    SARS-CoV-2 infection in cardiovascular disease: Unmet need of stem cell models

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    This review aims to summarise new approaches in SARS-CoV-2-related research in cardiology. We provide a head-to-head comparison of models, such as animal research and human pluripotent stem cells, to investigate the pathomechanisms of COVID-19 and find an efficient therapy. In vivo methods were useful for studying systemic processes of the disease; however, due to differences in animal and human biology, the clinical translation of the results remains a complex task. In vitro stem cell research makes cellular events more observable and effective for finding new drugs and therapies for COVID-19, including the use of stem cells. Furthermore, multicellular 3D organoids even make it possible to observe the effects of drugs to treat SARS-CoV-2 infection in human organ models

    Microglia control the spread of neurotropic virus infection via P2Y12 signalling and recruit monocytes through P2Y12-independent mechanisms

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    Neurotropic herpesviruses can establish lifelong infection in humans and contribute to severe diseases including encephalitis and neurodegeneration. However, the mechanisms through which the brain's immune system recognizes and controls viral infections propagating across synaptically linked neuronal circuits have remained unclear. Using a well-established model of alphaherpesvirus infection that reaches the brain exclusively via retrograde transsynaptic spread from the periphery, and in vivo two-photon imaging combined with high resolution microscopy, we show that microglia are recruited to and isolate infected neurons within hours. Selective elimination of microglia results in a marked increase in the spread of infection and egress of viral particles into the brain parenchyma, which are associated with diverse neurological symptoms. Microglia recruitment and clearance of infected cells require cell-autonomous P2Y12 signalling in microglia, triggered by nucleotides released from affected neurons. In turn, we identify microglia as key contributors to monocyte recruitment into the inflamed brain, which process is largely independent of P2Y12. P2Y12-positive microglia are also recruited to infected neurons in the human brain during viral encephalitis and both microglial responses and leukocyte numbers correlate with the severity of infection. Thus, our data identify a key role for microglial P2Y12 in defence against neurotropic viruses, whilst P2Y12-independent actions of microglia may contribute to neuroinflammation by facilitating monocyte recruitment to the sites of infection

    Single-Molecule Imaging Reveals Rapid Estradiol Action on the Surface Movement of AMPA Receptors in Live Neurons

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    Gonadal steroid 17β-estradiol (E2) exerts rapid, non-genomic effects on neurons and strictly regulates learning and memory through altering glutamatergic neurotransmission and synaptic plasticity. However, its non-genomic effects on AMPARs are not well understood. Here, we analyzed the rapid effect of E2 on AMPARs using single-molecule tracking and super-resolution imaging techniques. We found that E2 rapidly decreased the surface movement of AMPAR via membrane G protein-coupled estrogen receptor 1 (GPER1) in neurites in a dose-dependent manner. The cortical actin network played a pivotal role in the GPER1 mediated effects of E2 on the surface mobility of AMPAR. E2 also decreased the surface movement of AMPAR both in synaptic and extrasynaptic regions on neurites and increased the synaptic dwell time of AMPARs. Our results provide evidence for understanding E2 action on neuronal plasticity and glutamatergic neurotransmission at the molecular level
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