Hedgehog-mediated regulation of PPARγ controls metabolic patterns in neural precursors and shh-driven medulloblastoma

Sonic hedgehog (Shh) signaling is critical during development and its aberration is common across the spectrum of human malignancies. In the cerebellum, excessive activity of the Shh signaling pathway is associated with the devastating pediatric brain tumor medulloblastoma. We previously demonstrated that exaggerated de novo lipid synthesis is a hallmark of Shh-driven medulloblastoma and that hedgehog signaling inactivates the Rb/E2F tumor suppressor complex to promote lipogenesis. Indeed, such Shh-mediated metabolic reprogramming fuels tumor progression, in an E2F1- and FASN-dependent manner. Here, we show that the nutrient sensor PPARγ is a key component of the Shh metabolic network, particularly its regulation of glycolysis. Our data show that in primary cerebellar granule neural precursors (CGNPs), proposed medulloblastoma cells-of-origin, Shh stimulation elicits a marked induction of PPARγ alongside major glycolytic markers. This is also documented in the actively proliferating Shh-responsive CGNPs in the developing cerebellum, and PPARγ expression is strikingly elevated in Shh-driven medulloblastoma in vivo. Importantly, pharmacological blockade of PPARγ and/or Rb inactivation inhibits CGNP proliferation, drives medulloblastoma cell death and extends survival of medulloblastoma-bearing animals in vivo. This coupling of mitogenic Shh signaling to a major nutrient sensor and metabolic transcriptional regulator define a novel mechanism through which Shh signaling engages the nutrient sensing machinery in brain cancer, controls the cell cycle, and regulates the glycolytic index. This also reveals a dominant role of Shh in the etiology of glucose metabolism in medulloblastoma and underscores the function of the Shh → E2F1 → PPARγ axis in altering substrate utilization patterns in brain cancers in favor of tumor growth. These findings emphasize the value of PPARγ downstream of Shh as a global therapeutic target in hedgehog-dependent and/or Rb-inactivated tumors

The Effect of Epstein-Barr Virus Latent Membrane Protein 2 Expression on the Kinetics of Early B Cell Infection

Infection of human B cells with wild-type Epstein-Barr virus (EBV) in vitro leads to activation and proliferation that result in efficient production of lymphoblastoid cell lines (LCLs). Latent Membrane Protein 2 (LMP2) is expressed early after infection and previous research has suggested a possible role in this process. Therefore, we generated recombinant EBV with knockouts of either or both protein isoforms, LMP2A and LMP2B (Δ2A, Δ2B, Δ2A/Δ2B) to study the effect of LMP2 in early B cell infection. Infection of B cells with Δ2A and Δ2A/Δ2B viruses led to a marked decrease in activation and proliferation relative to wild-type (wt) viruses, and resulted in higher percentages of apoptotic B cells. Δ2B virus infection showed activation levels comparable to wt, but fewer numbers of proliferating B cells. Early B cell infection with wt, Δ2A and Δ2B viruses did not result in changes in latent gene expression, with the exception of elevated LMP2B transcript in Δ2A virus infection. Infection with Δ2A and Δ2B viruses did not affect viral latency, determined by changes in LMP1/Zebra expression following BCR stimulation. However, BCR stimulation of Δ2A/Δ2B cells resulted in decreased LMP1 expression, which suggests loss of stability in viral latency. Long-term outgrowth assays revealed that LMP2A, but not LMP2B, is critical for efficient long-term growth of B cells in vitro. The lowest levels of activation, proliferation, and LCL formation were observed when both isoforms were deleted. These results suggest that LMP2A appears to be critical for efficient activation, proliferation and survival of EBV-infected B cells at early times after infection, which impacts the efficient long-term growth of B cells in culture. In contrast, LMP2B did not appear to play a significant role in these processes, and long-term growth of infected B cells was not affected by the absence of this protein. © 2013 Wasil et al

Assessing the determinants of stillbirths and early neonatal deaths using routinely collected data in an inner city area

BACKGROUND: Within the UK there is considerable variation in the perinatal mortality rate. The objective of this study was to assess the factors associated with stillbirths and early neonatal deaths (ENND) and the suitability of the available databases in a health authority with one of the highest rates in the country. METHODS: Two case-control studies were carried out in three hospital trusts in the Lambeth, Southwark and Lewisham Health Authority, London, using routinely collected information. In one study, 342 stillbirths and 1,368 controls were included, and in the other study, 205 ENND and 820 controls were included. In the two studies cases and controls were matched for hospital trust. RESULTS: A birthweight below 1.5 kg was found in 54% and 48% of the stillbirths and ENND, respectively. More than 50% of the cases, stillbirths and ENND, had a length of gestation below 32 weeks. Length of gestation, birthweight, emergency caesarean section and age of the mother were associated with stillbirths. Birthweight and Apgar score at 1 minute as a categorical variable were associated with ENND. There was no direct evidence of an effect of social deprivation on the outcomes of interest. CONCLUSION: Birthweight and length of gestation are the most influential factors on an unfavourable outcome. Conception at an older age has a serious impact on stillbirth rates. In our health authority social disadvantage did not have a direct impact on stillbirth and ENND. Maternity information systems should collect routine data on fewer variables, but their quality in terms of value, standardization and completion rates must improve

Widespread Contribution of Gdf7 Lineage to Cerebellar Cell Types and Implications for Hedgehog-Driven Medulloblastoma Formation

The roof plate is a specialized embryonic midline tissue of the central nervous system that functions as a signaling center regulating dorsal neural patterning. In the developing hindbrain, roof plate cells express Gdf7 and previous genetic fate mapping studies showed that these cells contribute mostly to non-neural choroid plexus epithelium. We demonstrate here that constitutive activation of the Sonic hedgehog signaling pathway in the Gdf7 lineage invariably leads to medulloblastoma. Lineage tracing analysis reveals that Gdf7-lineage cells not only are a source of choroid plexus epithelial cells, but are also present in the cerebellar rhombic lip and contribute to a subset of cerebellar granule neuron precursors, the presumed cell-of-origin for Sonic hedgehog-driven medulloblastoma. We further show that Gdf7-lineage cells also contribute to multiple neuronal and glial cell types in the cerebellum, including glutamatergic granule neurons, unipolar brush cells, Purkinje neurons, GABAergic interneurons, Bergmann glial cells, and white matter astrocytes. These findings establish hindbrain roof plate as a novel source of diverse neural cell types in the cerebellum that is also susceptible to oncogenic transformation by deregulated Sonic hedgehog signaling

Evaluation of non-inferiority of intradermal versus adjuvanted seasonal influenza vaccine using two serological techniques: a randomised comparative study

<p>Abstract</p> <p>Background</p> <p>Although seasonal influenza vaccine is effective in the elderly, immune responses to vaccination are lower in the elderly than in younger adults. Strategies to optimise responses to vaccination in the elderly include using an adjuvanted vaccine or using an intradermal vaccination route. The immunogenicity of an intradermal seasonal influenza vaccine was compared with that of an adjuvanted vaccine in the elderly.</p> <p>Methods</p> <p>Elderly volunteers (age ≥ 65 years) were randomised to receive a single dose of trivalent seasonal influenza vaccine: either a split-virion vaccine containing 15 μg haemagglutinin [HA]/strain/0.1-ml dose administered intradermally, or a subunit vaccine (15 μg HA/strain/0.5-ml dose) adjuvanted with MF59C.1 and administered intramuscularly. Blood samples were taken before and 21 ± 3 days post-vaccination. Anti-HA antibody titres were assessed using haemagglutination inhibition (HI) and single radial haemolysis (SRH) methods. We aimed to show that the intradermal vaccine was non-inferior to the adjuvanted vaccine.</p> <p>Results</p> <p>A total of 795 participants were enrolled (intradermal vaccine n = 398; adjuvanted vaccine n = 397). Non-inferiority of the intradermal vaccine was demonstrated for the A/H1N1 and B strains, but not for the A/H3N2 strain (upper bound of the 95% CI = 1.53) using the HI method, and for all three strains by the SRH method. A <it>post-hoc </it>analysis of covariance to adjust for baseline antibody titres demonstrated the non-inferiority of the intradermal vaccine by HI and SRH methods for all three strains. Both vaccines were, in general, well tolerated; the incidence of injection-site reactions was higher for the intradermal (70.1%) than the adjuvanted vaccine (33.8%) but these reactions were mild and of short duration.</p> <p>Conclusions</p> <p>The immunogenicity and safety of the intradermal seasonal influenza vaccine in the elderly was comparable with that of the adjuvanted vaccine. Intradermal vaccination to target the immune properties of the skin appears to be an appropriate strategy to address the challenge of declining immune responses in the elderly.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: NCT00554333.</p

Thermoregulation and fluid balance during a 30-km march in 60-versus 80-year-old subjects

The presence of impaired thermoregulatory and fluid balance responses to exercise in older individuals is well established. To improve our understanding on thermoregulation and fluid balance during exercise in older individuals, we compared thermoregulatory and fluid balance responses between sexagenarians and octogenarians during prolonged exercise. Forty sexagenarians (60 ± 1 year) and 36 octogenarians (81 ± 2 year) volunteered to participate in a 30-km march at a self-selected pace. Intestinal temperature (T in) and heart rate were recorded every 5 km. Subjects reported fluid intake, while urine output was measured and sweat rate was calculated. Octogenarians demonstrated a lower baseline T in and a larger exercise-induced increase in T in compared to sexagenarians (1.2 ± 0.5 °C versus 0.7 ± 0.4 °C, p  0.05). These results suggest that thermoregulatory responses deteriorate with advancing age, while fluid balance is regulated appropriately during a 30-km walking march under moderate ambient conditions

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal