Journal of Labelled Compounds and RadiopharmaceuticalsVolume 58, Issue 4 p. 147-155 Abstracts Abstracts of the 23rd International Isotope Society (UK group) Symposium: synthesis and applications of labelled compounds 2014 A. Anwar, A. AnwarSearch for more papers by this authorS. Archibald, S. ArchibaldSearch for more papers by this authorD. Audisio, D. AudisioSearch for more papers by this authorG. Badman, G. BadmanSearch for more papers by this authorJ. Bergin, J. BerginSearch for more papers by this authorS. P. Bew, S. P. BewSearch for more papers by this authorJ. Bloom, J. BloomSearch for more papers by this authorN. Bushby, N. BushbySearch for more papers by this authorA. Busigin, A. BusiginSearch for more papers by this authorM. Y. T. Chan, M. Y. T. ChanSearch for more papers by this authorJ. Davies, J. DaviesSearch for more papers by this authorJ. Dilworth, J. DilworthSearch for more papers by this authorM. Dunscombe, M. DunscombeSearch for more papers by this authorC. S. Elmore, C. S. ElmoreSearch for more papers by this authorP. Engstrom, P. EngstromSearch for more papers by this authorM. J. Fuchter, M. J. FuchterSearch for more papers by this authorN. J. Geach, N. J. GeachSearch for more papers by this authorD. Georgin, D. GeorginSearch for more papers by this authorA. Griffiths, A. GriffithsSearch for more papers by this authorP. Hansen, P. HansenSearch for more papers by this authorG. Hardcastle, G. HardcastleSearch for more papers by this authorG. D. Hiatt-Gipson, G. D. Hiatt-GipsonSearch for more papers by this authorM. J. Hickey, M. J. HickeySearch for more papers by this authorS. L. Kitson, S. L. KitsonSearch for more papers by this authorA. Lashford, A. LashfordSearch for more papers by this authorE. Lenz, E. LenzSearch for more papers by this authorS. Lewinton, S. LewintonSearch for more papers by this authorW. J. S. Lockley, Corresponding Author W. J. S. Lockley Correspondence to: W. J. S. Lockley, Division of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK. E-mail: w.lockley@surrey.ac.ukSearch for more papers by this authorO. Loreau, O. LoreauSearch for more papers by this authorS. Maddocks, S. MaddocksSearch for more papers by this authorP. Marlière, P. MarlièreSearch for more papers by this authorA. McEwen, A. McEwenSearch for more papers by this authorT. S. Moody, T. S. MoodySearch for more papers by this authorP. Morgan, P. MorganSearch for more papers by this authorS. J. Roe, S. J. RoeSearch for more papers by this authorD. J. Schenk, D. J. SchenkSearch for more papers by this authorD. J. Speed, D. J. SpeedSearch for more papers by this authorR. A. Stockman, R. A. StockmanSearch for more papers by this authorK. Sumal, K. SumalSearch for more papers by this authorF. Taran, F. TaranSearch for more papers by this authorS. Thurston, S. ThurstonSearch for more papers by this authorM. Waring, M. WaringSearch for more papers by this authorW. H. Watters, W. H. WattersSearch for more papers by this author A. Anwar, A. AnwarSearch for more papers by this authorS. Archibald, S. ArchibaldSearch for more papers by this authorD. Audisio, D. AudisioSearch for more papers by this authorG. Badman, G. BadmanSearch for more papers by this authorJ. Bergin, J. BerginSearch for more papers by this authorS. P. Bew, S. P. BewSearch for more papers by this authorJ. Bloom, J. BloomSearch for more papers by this authorN. Bushby, N. BushbySearch for more papers by this authorA. Busigin, A. BusiginSearch for more papers by this authorM. Y. T. Chan, M. Y. T. ChanSearch for more papers by this authorJ. Davies, J. DaviesSearch for more papers by this authorJ. Dilworth, J. DilworthSearch for more papers by this authorM. Dunscombe, M. DunscombeSearch for more papers by this authorC. S. Elmore, C. S. ElmoreSearch for more papers by this authorP. Engstrom, P. EngstromSearch for more papers by this authorM. J. Fuchter, M. J. FuchterSearch for more papers by this authorN. J. Geach, N. J. GeachSearch for more papers by this authorD. Georgin, D. GeorginSearch for more papers by this authorA. Griffiths, A. GriffithsSearch for more papers by this authorP. Hansen, P. HansenSearch for more papers by this authorG. Hardcastle, G. HardcastleSearch for more papers by this authorG. D. Hiatt-Gipson, G. D. Hiatt-GipsonSearch for more papers by this authorM. J. Hickey, M. J. HickeySearch for more papers by this authorS. L. Kitson, S. L. KitsonSearch for more papers by this authorA. Lashford, A. LashfordSearch for more papers by this authorE. Lenz, E. LenzSearch for more papers by this authorS. Lewinton, S. LewintonSearch for more papers by this authorW. J. S. Lockley, Corresponding Author W. J. S. Lockley Correspondence to: W. J. S. Lockley, Division of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK. E-mail: w.lockley@surrey.ac.ukSearch for more papers by this authorO. Loreau, O. LoreauSearch for more papers by this authorS. Maddocks, S. MaddocksSearch for more papers by this authorP. Marlière, P. MarlièreSearch for more papers by this authorA. McEwen, A. McEwenSearch for more papers by this authorT. S. Moody, T. S. MoodySearch for more papers by this authorP. Morgan, P. MorganSearch for more papers by this authorS. J. Roe, S. J. RoeSearch for more papers by this authorD. J. Schenk, D. J. SchenkSearch for more papers by this authorD. J. Speed, D. J. SpeedSearch for more papers by this authorR. A. Stockman, R. A. StockmanSearch for more papers by this authorK. Sumal, K. SumalSearch for more papers by this authorF. Taran, F. TaranSearch for more papers by this authorS. Thurston, S. ThurstonSearch for more papers by this authorM. Waring, M. WaringSearch for more papers by this authorW. H. Watters, W. H. WattersSearch for more papers by this author First published: 12 March 2015 https://doi.org/10.1002/jlcr.3276Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume58, Issue4April 2015Pages 147-155 RelatedInformation

INTRODUCTION: Decorin is a small leucine-rich repeat protein found in many tissues throughout the body that has been shown to have anti-inflammatory and anti-fibrotic properties. Direct infusion of decorin into rodent cerebral cortex or spinal cord injuries can suppress fibrotic scarring and the expression of multiple axons growth inhibitory chondroitin sulphate proteoglycans (CSPGs) and semaphorin 3A(1-3). In addition, decorin has also been shown to "desensitize" neurons to the inhibitory effects of both CSPGs and myelin associated molecules4 in vitro. To further explore the therapeutic potential of decorin in treating CNS injuries, we tested the ability of decorin to promote recovery in a clinically relevant sub-acute (12 days post injury) rodent cervical spinal cord contusion injury model. METHODS: Unilateral contusion injuries were carried out on adult Sprague-Dawley rats at the C4/C5 spinal level. At 12 days after injury, animals were split into three groups. The decorin treatment group received an intrathecal infusion of human recombinant decorin core protein in saline over a period of 7 days. The remaining control spinal cord injured rats received either intrathecal infusion of saline vehicle or a catheter and no treatment. Functional recovery was assessed at time points ranging from 1 to 7 weeks post treatment with horizontal ladder and CatWalk gait analyses. RESULTS: Robust functional recovery was observed in decorin treated rats in both tests compared to control spinal cord injured rats that failed to show significant improvements. Histological analysis of decorin treated cords revealed robust increases in corticospinal tract collaterals and synaptic plasticity within spinal gray matter below sites of injury compared to controls. CONCLUSION: Our results demonstrate that intrathecal infusion of decorin at a clinically relevant time point of twelve days post injury can promote functional recovery and provide further support for the development of decorin as a therapy for the injured human spinal cord.

This review summarizes current progress on development of astrocyte transplantation therapies for repair of the damaged central nervous system. Replacement of neurons in the injured or diseased central nervous system is currently one of the most popular therapeutic goals, but if neuronal replacement is attempted in the absence of appropriate supporting cells (astrocytes and oligodendrocytes), then the chances of restoring neurological functional are greatly reduced. Although the past 20 years have offered great progress on oligodendrocyte replacement therapies, astrocyte transplantation therapies have been both less explored and comparatively less successful. We have now developed successful astrocyte transplantation therapies by pre-differentiating glial restricted precursor (GRP) cells into a specific population of GRP cell-derived astrocytes (GDAs) by exposing the GRP cells to bone morphogenetic protein-4 (BMP) prior to transplantation. When transplanted into transected rat spinal cord, rat and human GDAs(BMP) promote extensive axonal regeneration, rescue neuronal cell survival, realign tissue structure, and restore behavior to pre-injury levels on a grid-walk analysis of volitional foot placement. Such benefits are not provided by GRP cells themselves, demonstrating that the lesion environment does not direct differentiation in a manner optimally beneficial for the restoration of function. Such benefits also are not provided by transplantation of a different population of astrocytes generated from GRP cells exposed to ciliary neurotrophic factor (GDAs(CNTF)), thus providing the first transplantation-based evidence of functional heterogeneity in astrocyte populations. Moreover, lessons learned from the study of rat cells are strongly predictive of outcomes using human cells. Thus, these studies provide successful strategies for the use of astrocyte transplantation therapies for restoration of function following spinal cord injury.

PURPOSE OF REVIEWCentral to the obstacles to be overcome in moving promising cell-based therapies from the laboratory to the clinic is that of determining which of the many cell types being examined are optimal for repairing particular lesions.RECENT FINDINGSOur studies on astrocyte replacement therapies demonstrate clearly that some cells are far better than others at promoting recovery in spinal cord injury and that, at least in some cases, transplanting undifferentiated precursor cells is far less useful than transplanting specific astrocytes derived from those precursor cells. But further comparison between different approaches is hindered by the difficulties in replicating results between laboratories, even for well defined pharmacological agents and bioactive proteins. These difficulties in replication appear most likely to be due to unrecognized nuances in lesion characteristics and in the details of delivery of therapies.SUMMARYWe propose that the challenge of reproducibility provides a critical opportunity for refining cell-based therapies. If the utility of a particular approach is so restricted that even small changes in lesions or treatment protocols eliminate benefit, then the variability inherent in clinical injuries will frustrate translation. In contrast, rising to this challenge may enable discovery of refinements needed to confer the robustness needed for successful clinical trials.

Repairing trauma to the central nervous system by replacement of glial support cells is an increasingly attractive therapeutic strategy. We have focused on the less-studied replacement of astrocytes, the major support cell in the central nervous system, by generating astrocytes from embryonic human glial precursor cells using two different astrocyte differentiation inducing factors. The resulting astrocytes differed in expression of multiple proteins thought to either promote or inhibit central nervous system homeostasis and regeneration. When transplanted into acute transection injuries of the adult rat spinal cord, astrocytes generated by exposing human glial precursor cells to bone morphogenetic protein promoted significant recovery of volitional foot placement, axonal growth and notably robust increases in neuronal survival in multiple spinal cord laminae. In marked contrast, human glial precursor cells and astrocytes generated from these cells by exposure to ciliary neurotrophic factor both failed to promote significant behavioral recovery or similarly robust neuronal survival and support of axon growth at sites of injury. Our studies thus demonstrate functional differences between human astrocyte populations and suggest that pre-differentiation of precursor cells into a specific astrocyte subtype is required to optimize astrocyte replacement therapies. To our knowledge, this study is the first to show functional differences in ability to promote repair of the injured adult central nervous system between two distinct subtypes of human astrocytes derived from a common fetal glial precursor population. These findings are consistent with our previous studies of transplanting specific subtypes of rodent glial precursor derived astrocytes into sites of spinal cord injury, and indicate a remarkable conservation from rat to human of functional differences between astrocyte subtypes. In addition, our studies provide a specific population of human astrocytes that appears to be particularly suitable for further development towards clinical application in treating the traumatically injured or diseased human central nervous system.

Inhibitory chondroitin sulfate proteoglycans (CSPGs) and myelin-associated molecules are major impediments to axon regeneration within the adult central nervous system (CNS). Decorin infusion can however suppress the levels of multiple inhibitory CSPGs and promote axon growth across spinal cord injuries [Davies, J.E., Tang, X., Denning, J.W., Archibald, S.J., and Davies, S.J., 2004. Decorin suppresses neurocan, brevican, phosphacan and NG2 expression and promotes axon growth across adult rat spinal cord injuries. Eur. J. Neurosci. 19, 1226–1242]. A question remained as to whether decorin can also increase axon growth on inhibitory CSPGs and myelin via a direct effect on neurons. We have therefore conducted an in vitro analysis of neurite extension by decorin-treated adult dorsal root ganglion (DRG) neurons cultured on substrates of inhibitory CSPGs or myelin membranes mixed with laminin. Decorin treatment promoted 14.5 and 5-fold increases in average neurite length/neuron over untreated controls on CSPGs or myelin membranes respectively. In addition to suppressing inhibitory scar formation, our present data shows that decorin can directly boost the ability of neurons to extend axons within CSPG or myelin rich environments.

Background Two critical challenges in developing cell-transplantation therapies for injured or diseased tissues are to identify optimal cells and harmful side effects. This is of particular concern in the case of spinal cord injury, where recent studies have shown that transplanted neuroepithelial stem cells can generate pain syndromes. Results We have previously shown that astrocytes derived from glial-restricted precursor cells (GRPs) treated with bone morphogenetic protein-4 (BMP-4) can promote robust axon regeneration and functional recovery when transplanted into rat spinal cord injuries. In contrast, we now show that transplantation of GRP-derived astrocytes (GDAs) generated by exposure to the gp130 agonist ciliary neurotrophic factor (GDAs CNTF ), the other major signaling pathway involved in astrogenesis, results in failure of axon regeneration and functional recovery. Moreover, transplantation of GDA CNTF cells promoted the onset of mechanical allodynia and thermal hyperalgesia at 2 weeks after injury, an effect that persisted through 5 weeks post-injury. Delayed onset of similar neuropathic pain was also caused by transplantation of undifferentiated GRPs. In contrast, rats transplanted with GDAs BMP did not exhibit pain syndromes. Conclusion Our results show that not all astrocytes derived from embryonic precursors are equally beneficial for spinal cord repair and they provide the first identification of a differentiated neural cell type that can cause pain syndromes on transplantation into the damaged spinal cord, emphasizing the importance of evaluating the capacity of candidate cells to cause allodynia before initiating clinical trials. They also confirm the particular promise of GDAs treated with bone morphogenetic protein for spinal cord injury repair.

Background Transplantation of embryonic stem or neural progenitor cells is an attractive strategy for repair of the injured central nervous system. Transplantation of these cells alone to acute spinal cord injuries has not, however, resulted in robust axon regeneration beyond the sites of injury. This may be due to progenitors differentiating to cell types that support axon growth poorly and/or their inability to modify the inhibitory environment of adult central nervous system (CNS) injuries. We reasoned therefore that pre-differentiation of embryonic neural precursors to astrocytes, which are thought to support axon growth in the injured immature CNS, would be more beneficial for CNS repair. Results Transplantation of astrocytes derived from embryonic glial-restricted precursors (GRPs) promoted robust axon growth and restoration of locomotor function after acute transection injuries of the adult rat spinal cord. Transplantation of GRP-derived astrocytes (GDAs) into dorsal column injuries promoted growth of over 60% of ascending dorsal column axons into the centers of the lesions, with 66% of these axons extending beyond the injury sites. Grid-walk analysis of GDA-transplanted rats with rubrospinal tract injuries revealed significant improvements in locomotor function. GDA transplantation also induced a striking realignment of injured tissue, suppressed initial scarring and rescued axotomized CNS neurons with cut axons from atrophy. In sharp contrast, undifferentiated GRPs failed to suppress scar formation or support axon growth and locomotor recovery. Conclusion Pre-differentiation of glial precursors into GDAs before transplantation into spinal cord injuries leads to significantly improved outcomes over precursor cell transplantation, providing both a novel strategy and a highly effective new cell type for repairing CNS injuries.

Spinal cord sear tissue presents a combined physical and molecular barrier to axon regeneration. Theoretically, spinal cord injuries (SCIs) can be rendered more permissive to axon growth by either suppressing synthesis of misaligned, fibrotic scar tissue and associated axon growth inhibitors, or enzymatically degrading them. We have previously shown that acute infusion of human recombinant decorin core protein into discreet stab injuries of the rat dorsal column pathways effected a major suppression of inflammation, astrogliosis, and multiple axon growth inhibitory chondroitin sulfate proteoglycans, which combined to promote rapid axon growth across the injury site. The high efficiency of chondroitin sulfate proteoglycan (CSPG) core protein suppression (similar to 90%) suggested that decorin may promote CSPG degradation in addition to suppressing CSPG synthesis. As the serine protease plasmin can degrade axon growth inhibitory CSPGs (neurocan and phosphacan) and its zymogen, plasmininogen is synthesized by microglia, we have investigated whether decorin treatment of acute SCIs and cultured adult spinal cord microglia can increase plasminogen/plasmin synthesis. Infusion of hr-decorin over the first 8 days post-SCI induced 10- and 17-fold increases in plasminogen and plasmin protein levels, respectively, within sites of injury and a threefold increase in microglial plasminogen mRNA in vitro. In addition to potentially degrading multiple axon growth inhibitory components of the glial scar, plasmin is known to play major roles in activating neurotrophins and promoting central nervous system (CNS) plasticity. The wider implications of decorin induction of plasmin in the injured spinal cord for axon regeneration, and recovery of function at acute and chronic time points post-SCI are reviewed.

The formation of misaligned scar tissue by a variety of cell types expressing multiple axon growth inhibitory proteoglycans presents a physical and molecular barrier to axon regeneration after adult spinal cord injuries. Decorin is a small, leucine-rich proteoglycan that has previously been shown to reduce astrogliosis and basal lamina formation in acute cerebral cortex stab injuries. We have therefore tested whether mini pump infusion of hr-decorin into acute stab injuries of the adult rat spinal cord can not only inhibit formation of an astroglial limitans but also deposition of the axon growth inhibitory proteoglycans neurocan, NG2, phosphacan and brevican. Combined immunohistochemical and quantitative Western blot analysis revealed major reductions in levels of core protein expression (>80% for 130-kDa neurocan, 145/80-kDa brevican, 300-kDa phosphacan) and immunoreactivity for all four chondroitin sulfate proteoglycans (CSPGs) within decorin-treated injuries compared with untreated controls. Astrogliosis within lesion margins and the accumulation of OX42+ macrophages/microglia within lesion centres were also significantly reduced. These decorin-induced changes in scar formation combined to promote the striking ability of axons from microtransplanted adult sensory neurons to enter, grow within and exit decorin-infused spinal cord injuries, in sharp contrast to the complete failure of axons to cross untreated, CSPG-rich lesions. Decorin pretreatment of meningial fibroblasts in vitro also resulted in a three-fold increase in neurite outgrowth from co-cultured adult sensory neurons and suppression of NG2 immunoreactivity. The ability of decorin to promote axon growth across acute spinal cord injuries via a coordinated suppression of inflammation, CSPG expression and astroglial scar formation make decorin treatment a promising component of future spinal cord regeneration strategies.

Previous studies have correlated the failure of axon regeneration after spinal cord injury with axons contacting scar tissue rich in chondroitin sulfate proteoglycans (CSPGs; Davies et al., 1999). In the present study, we have conducted immunohistochemical and quantitative Western blot analysis of five axon-growth-inhibitory CSPGs and tenascin-C within stab injuries of adult rat spinal cord at time points ranging from 24 hr to 6 months post injury. Quantitative Western blot analysis showed robust increases in neurocan, tenascin-C, and NG2 levels by 24 hr, suggesting that these molecules play a role in preventing axon regeneration across acutely forming scar tissue. Peak levels of 245/130 kD neurocan, NG2, and 250/200 kD tenascin-C were reached at 8 days, with maximum levels of phosphacan and 140/80 kD brevican attained later, at 1 month post injury. Versican V2 protein levels, however, displayed an opposite trend, dropping below unlesioned spinal cord values at all time points studied. Confocal microscopy at 8 days post injury revealed heightened immunoreactivity for phosphacan, NG2, and tenascin-C, particularly within fibronectin(+) scar tissue at lesion centers. In contrast, neurocan was displayed within lesion margins on the processes of stellate NG2(+) cells and, to a much lesser extent, by astrocytes. At 6 months post injury, 130 kD neurocan, brevican, and NG2 levels within chronic scar tissue remained significantly above control. Our results show novel expression patterns and cell associations of inhibitory CSPGs and tenascin-C that have important implications for axon regeneration across acute and chronic spinal cord scar tissue.

Recent advances in understanding oligodendrocyte development have revealed the importance of both extra‐ and intracellular molecules in regulating the induction, survival, and proliferation of early oligodendrocyte progenitors. The signaling molecule Sonic hedgehog (Shh) is critical for normal development of oligodendrocytes, although the precise influences of Shh on cells of the oligodendrocyte lineage are unclear. The present study shows that Shh increased the number of oligodendrocyte precursors in both pure cultures of oligodendrocyte precursors and mixed cultures from embryonic rat spinal cord. In pure precursor cultures Shh increased cell survival. In mixed cultures, Shh increased both the survival and proliferation of oligodendrocyte precursors in a concentration dependent manner. One intracellular consequence of exposure to Shh is the activation of transcription factors in oligodendrocyte lineage cells, which are critical for oligodendrocyte development, helix‐loop‐helix (HLH) transcription factors, Olig1 and 2. In many cases, HLH proteins such as Olig1 and Olig2 heterodimerize with other HLH proteins, such as members of the E subfamily, which are critical regulators of cell proliferation and differentiation. Immature (A2B5+) and more mature (O4+) rat oligodendrocyte precursors in dissociated cell culture expressed Olig1 as well as E proteins, HEB and E2A. Similarly, cells bearing the morphology of oligodendrocyte precursors expressed both Olig1 and HEB or E2A. We propose that E2A and/or HEB, possibly in combination with Olig1 and 2, are critical components of oligodendrogenesis and may regulate cell survival, proliferation, and fate decisions in the oligodendrocyte lineage. GLIA 40:55–64, 2002. © 2002 Wiley‐Liss, Inc.

In the chick metencephalon, oligodendrocyte precursors arise in distinct domains of the ventricular zone. During development, the earliest oligodendrocyte precursors appear in the metencephalic ventral ventricular zone adjacent to the midline, consistent with their location in the spinal cord. In contrast to spinal cord, however, distinct domains in the lateral and dorsal metencephalic ventricular zone subsequently generate oligodendrocyte precursors. All oligodendrogenic domains of the metencephalon appear in close apposition to regions that transiently express sonic hedgehog (Shh). Inhibition studies demonstrate a functional requirement for Shh signaling in the early appearance of metencephalic oligodendrocyte precursors, while in vitro studies suggest a dose-dependent increase in the number of oligodendrocyte precursors in response to Shh. In purified cultures of oligodendrocyte precursors, Shh promotes cell survival and proliferation, suggesting that Shh can act directly on these cells. These data suggest that Shh may be responsible for the localized appearance of oligodendrocyte precursors throughout the CNS, irrespective of the dorso-ventral neural axis.