Evaluation of the C5a anaphylatoxin and its receptor (CD88) in allergic lung disease

Allergic asthma is characterized by airflow obstruction, airway hyperresponsiveness (AHR) and chronic airway inflammation. We and others have reported that complement component C3 and the anaphylatoxin C3a receptor promote while C5 protects against the development of the biological and physiological hallmarks of allergic lung disease in mice. In this study, we assessed if the protective responses could be mediated by C5a, an activation-induced C5 cleavage product. Mice with ablation of the C5a receptor (C5aR) either by genetic deletion or by pharmacological blockade exhibited significantly exacerbated AHR compared to allergen-challenged wild-type (WT) mice. However, there were no significant differences in many of the other hallmarks of asthma such as airway infiltration by eosinophils or lymphocytes, pulmonary IL-4-producing cell numbers, goblet cell metaplasia, mucus secretion or total serum IgE levels. In contrast to elevated AHR, numbers of IL-5 and IL-13 producing pulmonary cells, and IL-5 and IL-13 protein levels, were significantly reduced in allergen-challenged C5aR-/- mice compared to allergen-challenged WT mice. Administration of a specific cysteinyl leukotriene receptor 1 (cysLT1R) antagonist before each allergen-challenge abolished AHR in C5aR-/- as well as in WT mice. Pretreatment with a C3aR antagonist dose-dependently reduced AHR in allergen-challenged WT and C5aR-/- mice. Additionally, allergen-induced upregulation of pulmonary C3aR expression was exaggerated in C5aR-/- mice compared to WT mice. In summary, deficiency or antagonism of C5aR in a mouse model of pulmonary allergy increased AHR, which was reversed or reduced by blockade of the cysLT1R and C3aR, respectively. In conclusion, this study suggests that C5a and C5aR mediate protection against AHR by suppressing cysLT and C3aR signaling pathways, which are known to promote AHR. This also supports important and opposing roles of complement components C3a/C3aR and C5a/C5aR in AHR. ^

The Role of Type I Insulin-Like Growth Factor Receptor Signaling in Breast Cancer Brain Metastasis

Brain metastasis is a common cause of mortality in cancer patients. Approximately 20-30% of breast cancer patients acquire brain metastasis, yet potential therapeutic targets remain largely unknown. The type I insulin-like growth factor receptor (IGF- IR) is known to play a role in the progression of breast cancer and is currently being investigated in the clinical setting for various types of cancer. The present study demonstrates that the IGF-IR signaling axis is constitutively active in brain-seeking sublines of breast cancer cells, driving an increase in in vitro metastatic properties. We demonstrate that IGF-IR signaling is activated in an autocrine manner as a result of IGFBP3 overexpression in brain-seeking cells. Transient and stable knockdown of IGF-IR results in a downregulation of IGF-IR downstream signaling through phospho-AKT, as well as decreased in vitro migration and invasion of MDA- MB-231Br brain-seeking cells. Using an in vivo experimental brain metastasis model, we show that IGF-IR ablation attenuates the establishment of brain metastases and prolongs survival. Finally, we demonstrate that the malignancy of brain-seeking cells is attenuated by pharmacological inhibition with picropodophyllin, an IGF-IR-specific tyrosine kinase inhibitor. Together, our data suggest that the IGF-IR is an important mediator of brain metastasis and its ablation delays the onset of brain metastases in our model system.

PRKCa: Identification of a Novel Downstream Target of WT1

Wilms tumor is a childhood tumor of the kidney arising from the undifferentiated metanephric mesenchyme. Tumorigenesis is attributed to a number of genetic and epigenetic alterations. In 20% of Wilms tumors, Wilms tumor gene 1 (WT1) undergoes inactivating homozygous mutations causing loss of function of the zinc finger transcription factor it encodes. It is hypothesized that mutations in WT1 result in dysregulation of downstream target genes, leading to aberrant kidney development and/or Wilms tumor. These downstream target genes are largely unknown, and identification is important for further understanding Wilms tumor development. Heatmap data of human Wilms tumor protein expression, generated by reverse phase protein assay analysis (RPPA), show significant correlation between WT1 mutation status and low PRKCα expression (p= 0.00013); additionally, p-PRKCα (S657) also shows decreased expression in these samples (p= 0.00373). These data suggest that the WT1 transcription factor regulates PRKCα expression, and that PRKCα plays a potential role in Wilms tumor tumorigenesis. We hypothesize that the WT1 transcription factor directly/indirectly regulates PRKCα and mutations occurring in WT1 lead to decreased expression of PRKCα. Prkcα and Wt1 have been shown to co-localize in E14.5 mesenchymal cells of the developing kidney. siRNA knockdown, in-vivo ablation, and tet-inducible expression of Wt1 each independently confirm regulation of Prkcα expression by Wt1 at both RNA and protein levels, and investigation into possible WT1 binding sites in PRKCα regulatory regions has identified multiple sites to be confirmed by luciferase reporter constructs. With the goal of identifying WT1 and PRKCα downstream targets, RPPA analysis of protein expression in mesenchymal cell culture, following lentiviral delivered shRNA knockdown of Wt1 and shRNA knockdown of Prkcα, will be carried out. Apart from Wilms tumor, WT1 also plays an important role in Acute Myeloid Leukemia (AML). WT1 mutation status has been implicated, controversially, as an independent poor-prognosis factor in leukemia, leading to decreased probability of overall survival, complete remission, and disease free survival. RPPA analysis of AML patient samples showed significant decreases in PRKCα/p-PRKCα protein expression in a subset of patients (Kornblau, personal communication); therefore, the possible role of WT1 and PRKCα in leukemia disease progression is an additional focus of this study. WT1 mutation analysis of diploid leukemia patient samples revealed two patients with mutations predicted to affect WT1 activity; of these two samples, only one corresponded to the low PRKCα expression cohort. Further characterization of the role of WT1 in AML, and further understanding of WT1 regulated PRKCα expression, will be gained following RPPA analysis of protein expression in HL60 leukemia cell lines with lentiviral delivered shRNA knockdown of WT1 and shRNA knockdown of PRKCα.

Potential roles for bcl-2 in the pathogenesis, progression, and treatment of prostate cancer

The most common molecular alterations observed in prostate cancer are increased bcl-2 protein expression and mutations in p53. Understanding the molecular alterations associated with prostate cancer are critical for successful treatment and designing new therapeutic interventions. Hormone-ablation therapy remains the most effective nonsurgical treatment; however, most patients will relapse with hormone-independent, refractory disease. This study addresses how hormone-ablation therapy may increase bcl-2, develops a transgenic model to elucidate the role of bcl-2 multistep prostate carcinogenesis, and assesses how bcl-2 may confer resistance to cell death induction using adenoviral wild-type p53 gene therapy. ^ Two potential androgen response elements were identified in the bcl-2 promoter. Bcl-2 promoter luciferase constructs were transfected into the hormone- sensitive LNCaP prostate cell line. In the presence of dihydrotestosterone, the activity of one bcl-2 promoter luciferase construct was repressed 40% compared to control cells grown in charcoal-stripped serum. Additionally, it was demonstrated that both bcl-2 mRNA and protein were downregulated in the LNCaP cells grown in the presence DHT. This suggests that DHT represses bcl-2 expression through possible direct and indirect mechanisms and that hormone-ablation therapy may actually increases bcl-2 protein. ^ To determine the role of bcl-2 in prostate cancer progression in vivo, probasin-bcl-2 mice were generated where human bcl-2 was targeted to the prostate. Increased bcl-2 expression rendered the ventral prostate more resistant to apoptosis induction following castration. When the probasin-bcl-2 mice were crossed with TRAMP mice, the latency to tumor formation was decreased. The expression of bcl-2 in the double transgenic mice did not affect the incidence of metastases. The double transgenic model will facilitate the study of in vivo effects of specific genetic lesions during the pathogenesis of prostate cancer. ^ The effects of increased bcl-2 protein on wild-type adenoviral p53-mediated cell death were determined in prostatic cell lines. Increased bcl-2 protected PC3 and DU145 cell lines, which possess mutant p53, from p53-mediated cell death and reductions in cell viability. Bcl-2 did not provide the same protective effect in LNCaP cell line, which expresses wild-type p53. This suggests that the ability of bcl-2 to protect against p53-mediated cell death is dependent upon the endogenous status of p53. ^

Geochemistry of bulk samples and various minerals of sediment core CRP-1 from the Ross Sea, Antarctica

Thirty-nine medium and fine grained sandstones from between 19,26 and 147,23 mbsf in the Cape Roberts-l core (CRP-1) were analysed for 10 major and 16 trace elements. Using whole-lock compositions, 9 samples were selected for analyses of mineral and glass grains by energy dispersive electron microscope. Laser-Ablation Mass-Spectrometry was used to determine rare earth elements and 14 additional trace elements in glass shards, pyroxenes and feldspars in order to examine their contribution to the bulk rock chemistry. Geochemical data reveal the major contribution played by the Granite Harbour Intrusives to the whole rock composition, even if a significant input is supplied by McMurdo volcanics and Ferrar dolerite pyroxenes McMurdo volcanics were studied in detail; they appeal to derive from a variety of litologies, and a dominant role of wind transpoitation from exposures of volcanic rocks may be inferred from the contemporary occurrence of different compositions at all depths. Only at 116.55 mbsf was a thin layer of tephra found, linked to an explosive eruption McMurdo volcanic rocks exhibit larger abundances at depths above 62 mbsf, in correspondence with the onset of volcanic activity in the McMurdo Sound area. From 62 mbsf to the bottom of the core, McMurdo volcanics are less abundant and probably issued from some centres in the McMurdo Sound region. However, available data do not allow the exclusion of wind transport from some eruptive centres active in north Victoria Land at the beginning of the Miocene Epoch.

Geological and geochemical characteristics of the Tersang gold deposit, Malaysia: implications for genesis and gold exploration

The Central gold belt of peninsular Malaysia comprises a number of gold deposits located in the east of the N-S striking Bentong-Raub Suture Zone. The Tersang gold deposit is one of the gold deposits in the gold belt and hosted in sandstone, rhyolite and breccia units. The deposit has an inferred resource of 528,000 ounces of gold. The geochronology of the Tersang deposit has been newly constrained by LA ICP-MS U-Pb zircon dating. The maximum depositional age of the host sedimentary rocks ranges from Early Carboniferous to Early Permian (261.5 ± 4.9 Ma to 333.5 ± 2.5 Ma) for the host sandstone and Late Triassic for the rhyolite intrusion (218.8 ± 1.7 Ma). Textural characteristics of pyrite have revealed five types including (1) Euhedral to subhedral pyrite with internal fracturing and porous cores located in the sandstone layers (pyrite 1); (2) Anhedral pyrite overgrowths on pyrite 1 and disseminated in stage 1 vein (pyrite 2); (3) Fracture-filled or vein pyrite located in stages 1 and 2 vein (pyrite 3); (4) Euhedral pyrite with internal fractures also located in stage 2 vein (pyrite 4); and (5) Subhedral clean pyrite located in the rhyolite intrusion (pyrite 5). Based on pyrite mapping and spot analyses, two main stages of gold enrichment are documented from the Tersang gold deposit. Gold in sandstone-hosted pyrite 1 (mean 4.3 ppm) shows best correlation with Bi and Pb (as evidenced on pyrite maps). In addition, gold in pyrite 3 (mean 8 ppm) located in stage 2 vein shows a good correlation with As, Ag, Sb, Cu, Tl, and Pb. In terms of gold exploration, we suggest that elements such as As, Ag, Sb, Cu, Tl, Bi, and Pb associated with Au may serve as vectoring tools in gold exploration. Our new geological, structural, geochemical and isotopic data together with mineral paragenesis, pyrite chemistry and ore fluid characteristics indicate that the Tersang gold deposit is comparable to a sediment-hosted gold deposit. Our new genetic model suggests deposition of the Permo-Carboniferous sediments followed by intrusion of rhyolitic magma in the Late Triassic. At a later stage, gold mineralisation overprinted the rhyolite intrusion and the sandstone.

Geochemistry of minerals in CRP sediment cores from the Ross Sea, Antarctica

Sixty-four volcanic chists, sandstones and tephras between 5.95 and 618.19 meters below sea floor (mbsf) in the Cape Roberts Project cores 2 and 2A cores (CRP-2/2A) were examined for Cenozoic and Mesozoic volcanic components, using optical and Scanning Electron Microscopy. Minerals and glass shards in a selection of samples were analysed by electron microprobe fined with an EDAX detector. Laser-Ablation ICP-Mass-Spectrometry (ICP-MS) was used to determine rare earth elements and 14 additional trace elements in glass shards, pyroxenes and feldspars in order to pin-point the onset of McMurdo Volcanic Group (MVG) activity in the stratigraphic column. Pumices in tephra layers of peralkaline phonolite composition in Unit 7.2 -between 108 and 114 mbsf - were also analysed for trace elements by ICP-MS. This tephra unit is not reworked and its isotopic age (21.44 ± 0.05 Ma) is the age of deposition. The height of the eruptive column responsible for the deposition of the tephra was probably less than 8 km; the source was local, probably within 30 km from the drill site. Phonolite of unit 7.2 of CRP-2/2A has no direct petrogenetic relation with the peralkaline trachyte in the tephra-enriched layer of CRP-1 at 116.55 mbsf. Volcanic clasts and sand grains (glass shards, aegirine-augite, anorthoclase) related to Cenozoic activity of MVG were observed only starting from Unit 9.8, where they are dated at 24.22 ± 0.06 Ma at c. 280 mbsf. In this unit the lowest- occurring basaltic glass shard is found at 297.54 mbsf. Sampled McMurdo volcanics are generally vesicular and vary in composition from alkali basalt to trachyte and peralkaline phonolite. By contrast, below 320 mbsf, aphyric or slightly-porphyritic volcanic clasts become more abundant but they are all non-vesiculated, pigeconite and ilmenite-bearing basalts and dolerite of tholeiitic affinity. These rocks are considered to be related to lava flows and associated intrusions of Jurassic age (Kirkpatrick basalts and Ferrar dolerite). As in CRP-1, McMurdo volcanics appear to derive from a variety of lithologics. Besides glaciers, a dominant role of wind transportation from exposed volcanic rocks may be inferred from the contemporary occurrence of glass shards of different compositions at depths above 297.54 mbsf. These data confirm that the onset of magmatic activity in southern Victoria Land is considerably delayed (by about 24 Ma) with respect to northern Victoria Land.

Tab. 1: Results of the movement measurements on the blue ice-field Blåisen

In January/February 1985 a German-South African expedition had the opportunity to repeat measurements made by means of stakes planted in 1951 (Norwegian-British-Swedish Antarctic Expedition 1949-52) and 1966 (SANAE VII). Although the rediscovery of the old stakes had not been expected, the stakes could be identified and it was possible to derive movement vectors on the basis of old and heterogenic measurement data. The long-term movement rates established basically confirm and complement the values determined in 1951. The flow rates of 9,1 cm/a to 66.4 cm/a proved to be extremly low. Observations of the stake lengths showed very little accumulation in the fringe areas of the blue ice-field (ca. 0.7 to 2.6 cm/a snow/firn); on bare ice an ablation of 2.6 cm/a water equivalent (2.9 cm/a ice) was measured. The paper begins with a description of the essential conditions for the formation of the blue ice-field. Subsequently the measurements are explained in detail and their results are discussed.

Geochemistry and oxygen and iron isotope ratios of mafic rocks

Recycling of oceanic crust into the deep mantle via subduction is a widely accepted mechanism for creating compositional heterogeneity in the upper mantle and for explaining the distinct geochemistry of mantle plumes. The oxygen isotope ratios (d18O) of some ocean island basalts (OIB) span values both above and below that of unmetasomatised upper mantle (5.5 ± 0.4 per mil) and provide support for this hypothesis, as it is widely assumed that most variations in d18O are produced by near-surface low-temperature processes. Here we show a significant linear relationship between d18O and stable iron isotope ratios (d57Fe) in a suite of pristine eclogite xenoliths. The d18O values of both bulk samples and garnets range from values within error of normal mantle to significantly lighter values. The observed range and correlation between d18O and d57Fe is unlikely to be inherited from oceanic crust, as d57Fe values determined for samples of hydrothermally altered oceanic crust do not differ significantly from the mantle value and show no correlation with d18O. It is proposed that the correlated d57Fe and d18O variations in this particular eclogite suite are predominantly related to isotopic fractionation by disequilibrium partial melting although modification by melt percolation processes cannot be ruled out. Fractionation of Fe and O isotopes by removal of partial melt enriched in isotopically heavy Fe and O is supported by negative correlations between bulk sample d57Fe and Cr content and bulk sample and garnet d18O and Sc contents, as Cr and Sc are elements that become enriched in garnet- and pyroxene-bearing melt residues. Melt extraction could take place either during subduction, where the eclogites represent the residues of melted oceanic lithosphere, or could take place during long-term residence within the lithospheric mantle, in which case the protoliths of the eclogites could be of either crustal or mantle origin. This modification of both d57Fe and d18O by melting processes and specifically the production of low-d18O signatures in mafic rocks implies that some of the isotopically light d18O values observed in OIB and eclogite xenoliths may not necessarily reflect near-surface processes or components.

Chronostratigraphic framework at sites GeoB14403 and GeoB14414 from the Gela Basin, Sicily Channel

A multi-proxy chronological framework along with sequence-stratigraphic interpretations unveils composite Milankovitch cyclicity in the sedimentary records of the Last GlacialeInterglacial cycle at NE Gela Basin on the Sicilian continental margin. Chronostratigraphic data (including foraminifera-based eco-biostratigraphy and d18O records, tephrochronological markers and 14C AMS radiometric datings) was derived from the shallow-shelf drill sites GeoB14403 (54.6 m recovery) and GeoB14414 (27.5 m), collected with both gravity and drilled MeBo cores in 193 m and 146 m water depth, respectively. The recovered intervals record Marine Isotope Stages and Substages (MIS) from MIS 5 to MIS 1, thus comprising major stratigraphic parts of the progradational deposits that form the last 100-ka depositional sequence. Calibration of shelf sedimentary units with borehole stratigraphies indicates the impact of higher-frequency (20-ka) sea level cycles punctuating this 100-ka cycle. This becomes most evident in the alternation of thick interstadial highstand (HST) wedges and thinner glacial forced-regression (FSST) units mirroring seaward shifts in coastal progradation. Albeit their relatively short-lived depositional phase, these subordinate HST units form the bulk of the 100-ka depositional sequence. Two mechanisms are proposed that likely account for enhanced sediment accumulation ratios (SAR) of up to 200 cm/ka during these intervals: (1) intensified activity of deep and intermediate Levantine Intermediate Water (LIW) associated to the drowning of Mediterranean shelves, and (2) amplified sediment flux along the flooded shelf in response to hyperpycnal plumes that generate through extreme precipitation events during overall arid conditions. Equally, the latter mechanism is thought to be at the origin of undulated features resolved in the acoustic records of MIS 5 Interstadials, which bear a striking resemblance to modern equivalents forming on late-Holocene prodeltas of other Mediterranean shallow-shelf settings.

U-Pb (zircon) geochronologic analyses for rocks of the Transantarctic Mountains (Table 4.3-1)

The Byrd Glacier discontinuity us a major boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consits of two-dimensional transects across the belt, but do not adress the major longitudinal contrast at Byrd Glacier. This paper presents a tectonic model centering on the Byrd Glacier discontinuity. Rifting in the Neoproterozoic producede a crustal promontory in the craton margin to the north of Byrd Glacier. Oblique convergence of the terrane (Beardmore microcontinent) during the latest Neroproterozoic and Early Cambrian was accompanied by subduction along the craton margin of East Antarctica. New data presented herein in the support of this hypothesis are U-Pb dates of 545.7 ± 6.8 Ma and 531.0 ± 7.5 Ma on plutonic rocks from the Britannia Range, subduction stepped out, and Byrd Glacier. After docking of the terrane, subduction stepped out, and Byrd Group was deposited during the Atdabanian-Botomian across the inner margin of the terrane. Beginning in the upper Botomian, reactivation of the sutured boundaries of the terrane resulted in an outpouring of clastic sediment and folding and faulting of the Byrd Group.