Epac2 Elevation Reverses Inhibition by Chondroitin Sulfate Proteoglycans In Vitro and Transforms Postlesion Inhibitory Environment to Promote Axonal Outgrowth in an Ex Vivo Model of Spinal Cord Injury.

Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth are partly mediated by Epac, comprising Epac1 and Epac2; the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated, for the first time, that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulfate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated, for the first time, that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks after treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia after injury to facilitate axonal outgrowth.SIGNIFICANCE STATEMENT During development, neuronal cAMP levels decrease significantly compared with the embryonic stage when the nervous system is established. This has important consequences following spinal cord injury, as neurons fail to regrow. Elevating cAMP levels encourages injured CNS neurons to sprout and extend neurites. We have demonstrated that activating its downstream effector, Epac2, enhances neurite outgrowth in vitro, even in the presence of an inhibitory environment. Using a novel biomaterial-based drug delivery system in the form of a hydrogel to achieve local delivery of an Epac2 agonist, we further demonstrated that specific activation of Epac2 enhances axonal outgrowth and minimizes glial activation in an ex vivo model of spinal cord injury, suggesting a new strategy for spinal cord repair.International Spinal Research TrustScottish Rugby UnionRS McDonald Charitable Trus

Bypassing nearest hospital for more distant neuroscience care in head-injured adults with suspected traumatic brain injury: findings of the head injury transportation straight to neurosurgery (HITS-NS) pilot cluster randomised trial

OBJECTIVE: Reconfiguration of trauma services, with direct transport of patients with traumatic brain injury (TBI) to specialist neuroscience centres (SNCs)-bypassing non-specialist acute hospitals (NSAHs), could improve outcomes. However, delays in stabilisation of airway, breathing and circulation (ABC) may worsen outcomes when compared with selective secondary transfer from nearest NSAH to SNC. We conducted a pilot cluster randomised controlled trial to determine the feasibility and plausibility of bypassing suspected patients with TBI -directly into SNCs-producing a measurable effect. SETTING: Two English Ambulance Services. PARTICIPANTS: 74 clusters (ambulance stations) were randomised within pairs after matching for important characteristics. Clusters enrolled head-injured adults-injured nearest to an NSAH-with internationally accepted TBI risk factors and stable ABC. We excluded participants attended by Helicopter Emergency Medical Services or who were injured more than 1 hour by road from nearest SNC. INTERVENTIONS: Intervention cluster participants were transported directly to an SNC bypassing nearest NSAH; control cluster participants were transported to nearest NSAH with selective secondary transfer to SNC. OUTCOMES: Trial recruitment rate (target n=700 per annum) and percentage with TBI on CT scan (target 80%) were the primary feasibility outcomes. 30-day mortality, 6-month Extended Glasgow Outcome Scale and quality of life were secondary outcomes. RESULTS: 56 ambulance station clusters recruited 293 patients in 12 months. The trial arms were similar in terms of age, conscious level and injury severity. Less than 25% of recruited patients had TBI on CT (n=70) with 7% (n=20) requiring neurosurgery. Complete case analysis showed similar 30-day mortality in the two trial arms (control=8.8 (2.7-14.0)% vs intervention=9.4(2.3-14.0)%). CONCLUSION: Bypassing patients with suspected TBI to SNCs gives an overtriage (false positive) ratio of 13:1 for neurosurgical intervention and 4:1 for TBI. A measurable effect from a full trial of early neuroscience care following bypass is therefore unlikely. TRIAL REGISTRATION NUMBER: ISRCTN68087745

Dynamic microtubules regulate the local concentration of E-cadherin at cell-cell contacts

In contrast to the well-established relationship between cadherins and the actin cytoskeleton, the potential link between cadherins and microtubules (MTs) has been less extensively investigated. We now identify a pool of MTs that extend radially into cell-cell contacts and are inhibited by manoeuvres that block the dynamic activity of MT plus-ends (e.g. in the presence of low concentrations of nocodazole and following expression of a CLIP-170 mutant). Blocking dynamic MTs perturbed the ability of cells to concentrate and accumulate E-cadherin at cell-cell contacts, as assessed both by quantitative immunofluorescence microscopy and fluorescence recovery after photobleaching (FRAP) analysis, but did not affect either transport of E-cadherin to the plasma membrane or the amount of E-cadherin expressed at the cell surface. This indicated that dynamic MTs allow cells to concentrate E-cadherin at cell-cell contacts by regulating the regional distribution of E-cadherin once it reaches the cell surface. Importantly, dynamic MTs were necessary for myosin II to accumulate and be activated at cadherin adhesive contacts, a mechanism that supports the focal accumulation of E-cadherin. We propose that this population of MTs represents a novel form of cadherin-MT cooperation, where cadherin adhesions recruit dynamic MTs that, in turn, support the local concentration of cadherin molecules by regulating myosin II activity at cell-cell contacts

The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) prisons project: a randomised controlled trial comparing dihydrocodeine and buprenorphine for opiate detoxification

<p>Abstract</p> <p>Background</p> <p>Many opiate users entering British prisons require prescribed medication to help them achieve abstinence. This commonly takes the form of a detoxification regime. Previously, a range of detoxification agents have been prescribed without a clear evidence base to recommend a drug of choice. There are few trials and very few in the prison setting. This study compares dihydrocodeine with buprenorphine.</p> <p>Methods</p> <p>Open label, pragmatic, randomised controlled trial in a large remand prison in the North of England. Ninety adult male prisoners requesting an opiate detoxification were randomised to receive either daily sublingual buprenorphine or daily oral dihydrocodeine, given in the context of routine care. All participants gave written, informed consent. Reducing regimens were within a standard regimen of not more than 20 days and were at the discretion of the prescribing doctor. Primary outcome was abstinence from illicit opiates as indicated by a urine test at five days post detoxification. Secondary outcomes were collected during the detoxification period and then at one, three and six months post detoxification. Analysis was undertaken using relative risk tests for categorical data and unpaired t-tests for continuous data.</p> <p>Results</p> <p>64% of those approached took part in the study. 63 men (70%) gave a urine sample at five days post detoxification. At the completion of detoxification, by intention to treat analysis, a higher proportion of people allocated to buprenorphine provided a urine sample negative for opiates (abstinent) compared with those who received dihydrocodeine (57% vs 35%, RR 1.61 CI 1.02–2.56). At the 1, 3 and 6 month follow-up points, there were no significant differences for urine samples negative for opiates between the two groups. Follow up rates were low for those participants who had subsequently been released into the community.</p> <p>Conclusion</p> <p>These findings would suggest that dihydrocodeine should not be routinely used for detoxification from opiates in the prison setting. The high relapse rate amongst those achieving abstinence would suggest the need for an increased emphasis upon opiate maintenance programmes in the prison setting.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN07752728</p

Jack-of-all-trades, master of none: Postgraduate perspectives on interdisciplinary health research in Australia

BACKGROUND: Interdisciplinary health research is increasingly perceived as an expectation of research institutions and funding bodies within Australia. However, little consideration has been given to the extent to which this re-orientation has produced a new type of researcher – an interdisciplinary health researcher. DISCUSSION: As cross-enrolled postgraduate research students, we assert that we do not have an intellectual home. Rather, we must forge a virtual intellectual home through the process of bridging disciplines. In this paper we explain that this virtual home affords us the role of 'interlockers' in future health research. The interlocker role privileges a breadth of understandings across disciplines, rather than a depth in one. SUMMARY: We conclude by reiterating that there is an undeniable need for interdisciplinary health research, and that the roles and actions of interdisciplinary health researchers need to be better understood and catered for. We therefore call for increased consideration and discussion concerning the future roles and capacities of interdisciplinary health researchers such as ourselves

CD24 Is Not Required for Tumor Initiation and Growth in Murine Breast and Prostate Cancer Models

CD24 is a small, heavily glycosylated, GPI-linked membrane protein, whose expression has been associated with the tumorigenesis and progression of several types of cancer. Here, we studied the expression of CD24 in tumors of MMTV-PyMT, Apc1572/T+ and TRAMP genetic mouse models that spontaneously develop mammary or prostate carcinoma, respectively. We found that CD24 is expressed during tumor development in all three models. In MMTV-PyMT and Apc1572T/+ breast tumors, CD24 was strongly but heterogeneously expressed during early tumorigenesis, but decreased in more advanced stages, and accordingly was increased in poorly differentiated lesions compared with well differentiated lesions. In prostate tumors developing in TRAMP mice, CD24 expression was strong within hyperplastic lesions in comparison with non-hyperplastic regions, and heterogeneous CD24 expression was maintained in advanced prostate carcinomas. To investigate whether CD24 plays a functional role in tumorigenesis in these models, we crossed CD24 deficient mice with MMTV-PyMT, Apc1572T/+ and TRAMP mice, and assessed the influence of CD24 deficiency on tumor onset and tumor burden. We found that mice negative or positive for CD24 did not significantly differ in terms of tumor initiation and burden in the genetic tumor models tested, with the exception of Apc1572T/+ mice, in which lack of CD24 reduced the mammary tumor burden slightly but significantly. Together, our data suggest that while CD24 is distinctively expressed during the early development of murine mammary and prostate tumors, it is not essential for the formation of tumors developing in MMTV-PyMT, Apc1572T/+ and TRAMP mice

TRAF4 is a novel phosphoinositide-binding protein modulating tight junctions and favoring cell migration

Tumor necrosis factor (TNF) receptor-associated factor 4 (TRAF4) is frequently overexpressed in carcinomas, suggesting a specific role in cancer. Although TRAF4 protein is predominantly found at tight junctions (TJs) in normal mammary epithelial cells (MECs), it accumulates in the cytoplasm of malignant MECs. How TRAF4 is recruited and functions at TJs is unclear. Here we show that TRAF4 possesses a novel phosphoinositide (PIP)-binding domain crucial for its recruitment to TJs. Of interest, this property is shared by the other members of the TRAF protein family. Indeed, the TRAF domain of all TRAF proteins (TRAF1 to TRAF6) is a bona fide PIP-binding domain. Molecular and structural analyses revealed that the TRAF domain of TRAF4 exists as a trimer that binds up to three lipids using basic residues exposed at its surface. Cellular studies indicated that TRAF4 acts as a negative regulator of TJ and increases cell migration. These functions are dependent from its ability to interact with PIPs. Our results suggest that TRAF4 overexpression might contribute to breast cancer progression by destabilizing TJs and favoring cell migration

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist