Proteomics of Nitrogen Remobilization in Poplar Bark

Seasonal nitrogen (N) cycling in temperate deciduous trees involves the accumulation of bark storage proteins (BSPs) in phloem parenchyma and xylem ray cells. BSPs are anabolized using recycled N during autumn leaf senescence and later become a source of N during spring shoot growth as they are catabolized. Little is known about the catabolic processes involved in remobilization and reutilization of N from BSPs in trees. In this study, we used multidimensional protein identification technology (MudPIT) and spectral counting to identify protein changes that occur in the bark during BSP catabolism. A total of 4,178 proteins were identified from bark prior to and during BSP catabolism. The majority (62%) of the proteins were found during BSP catabolism, indicating extensive remodeling of the proteome during renewed shoot growth and N remobilization. Among these proteins were 30 proteases, the relative abundances of which increased during BSP catabolism. These proteases spanned a range of families including members of the papain-like cysteine proteases, serine carboxypeptidases, and aspartyl proteases. These data identify, for the first time, candidate proteases that could potentially provide hydrolase activity required for N remobilization from BSPs and provide the foundation for research to advance our knowledge of poplar N cycling

Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats-1

<p><b>Copyright information:</b></p><p>Taken from "Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats"</p><p>Environmental Health Perspectives 2005;113(6):729-734.</p><p>Published online 15 Feb 2005</p><p>PMCID:PMC1257598.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats-2

<p><b>Copyright information:</b></p><p>Taken from "Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats"</p><p>Environmental Health Perspectives 2005;113(6):729-734.</p><p>Published online 15 Feb 2005</p><p>PMCID:PMC1257598.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats-3

<p><b>Copyright information:</b></p><p>Taken from "Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats"</p><p>Environmental Health Perspectives 2005;113(6):729-734.</p><p>Published online 15 Feb 2005</p><p>PMCID:PMC1257598.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Prolonged CHIKV viremia with age and evidence of persistent infection.

<p>(A) Serum and (B) CHIKV-inoculated feet were harvested on indicated days post-infection and assayed for viral titer by plaque assay. (A) Serum viral titers on days 1–4 post-infection and (B) viral titer of CHIKV feet on days 3 and 9 post-infection (<i>n</i> = 7–8 per group). (C) Genome copies of virus in CHIKV feet on day 60 post-infection (<i>n</i> = 16–18 per group). (D) CHIKV-inoculated feet were harvested at day 90 p.i. and assayed for the presence of fluorescent infectious virus by co-culture on C6/36 insect cells (n = 8–10 per group). Dashed line indicates limit of detection for all assays. Horizontal lines indicate the median. Statistical significance determined on log-transformed data by unpaired student’s <i>t</i>-test. *<i>P</i>< 0.05; **<i>P</i>< 0.01; ***<i>P</i>< 0.001.</p

Age-related impairment of adaptive immune response to CHIKV.

<p>(A) Popliteal LNs collected and quantified from either naïve or CHIKV-infected A and O mice at day 3, 7, or 9 post-infection. The LN draining from the CHIKV-inoculated foot is indicated as dLN and from the non-inoculated foot as ndLN. Table under graph indicates the average fold-increase from naïve for each age in either the dLN or ndLN (<i>n</i> = 6–8 per group). Horizontal lines indicate the median. Statistical significance determined by student’s <i>t</i>-test. (B-C) Lymphocytes from popliteal LNs on d7 post-infection were stimulated with CHIKV peptides in the presence of protein transport inhibitor. Total number of IFNγ⁺ CD4 T cells (B) and frequency (C) for each age. Data are mean ± SEM (<i>n</i> = 10 per group). Statistical significance determined by unpaired Student’s <i>t</i>-test. (D) CHIKV-specific IgM and (E) IgG2c in serum determined by ELISA at the indicated day post-infection. Data are mean (<i>n</i> = 4–24 per group). Statistical significance was determined by two-way ANOVA with Bonferroni post-test. (F) Plaque reduction neutralizing test on serum from days 9 and 60 post-infection. Data are mean + SEM (<i>n</i> = 12 per group). Statistical significance was determined by two-way ANOVA with Bonferroni post-test. (G) Serum samples collected from patients experiencing acute CHIKV-disease were evaluated by plaque reduction neutralizing test. Data are mean + SEM (<i>n</i> = 24 young and 15 aged). Statistical significance was evaluated by unpaired student’s <i>t</i>-test. In all panels black indicates A, red indicates O; * <i>P</i>< 0.05; ** <i>P</i>< 0.01; *** <i>P</i>< 0.001.</p

Blocking TGFβ prevents acute CHIKV-induced disease in O mice.

<p>A and O B6 mice were inoculated and treated with 100ug of anti-TGFβ antibody or isotype control and swelling was measured daily as described in Methods. Data are mean ± SEM (n = 8 per group). Statistical significance was determined using mixed model, repeated measures analyses of variance (ANOVA) as detailed in Statistics. Red stars indicate reduction of swelling in O mice from αIgG1 to αTGFβ treated; black stars indicate reduction of swelling in A mice from αIgG1 to αTGFβ treated.</p

Age increases acute CHIKV-induced joint swelling.

<p>(A) A (12 weeks) and O (18–20 months) B6 mice were inoculated via f.p. and swelling was measured daily as described in Methods. Data are mean ±SEM (<i>n</i> = 10–16 per group). Statistical significance was determined using mixed model, repeated measures analyses of variance (ANOVA) as detailed in Statistics. ***<i>P</i>< 0.001.</p

Dysregulated cytokine production with age.

<p>Serum was collected from A and O mice and assayed by ELISA for (A) CXCL9 or (B) TGFβ concentration at days 2 or 9 and 30, respectively. Data are mean + SEM (<i>n</i> = 3 naïve and 7–8 infected per age). (C) Human samples from IgM-positive CHIKV patients or age and sex-matched controls were assayed for Free-active TGFβ cytokine by ELISA. Data are mean + SEM (<i>n</i> = 39 each group). Statistical significance was evaluated by unpaired student’s <i>t</i>-test. * <i>P</i>< 0.05; ** <i>P</i>< 0.01; *** <i>P</i>< 0.001.</p