Differential proteomic analysis of adrenal gland during postnatal development

The adrenal glands (AGs) are endocrine organs essential for life. They undergo a fetal to adult developmental maturation process, occurring in rats during the first postnatal month. The molecular modifications underlying these ontogenic changes are essentially unknown. Here we report the results of a comparative proteomic analysis performed on neonatal (Postnatal day 3) versus adult (Postnatal day 30) AGs, searching for proteins with a relative higher abundance at each age. We have identified a subset of proteins with relevant expression in each developmental period using 2‐DE and DIGE analysis. The identified proteins belong to several functional categories, including proliferation/differentiation, cell metabolism, and steroid biosynthesis. To study if the changes in the proteome are correlated with changes at the mRNA level, we have randomly selected several proteins with differential expression and measured their relative mRNA levels using quantitative RT‐PCR. Cell‐cycle regulating proteins (retinoblastoma binding protein 9 and prohibitin) with contrasting effects on proliferation are expressed differentially in neonatal and adult AG. Progesterone metabolizing enzymes, up‐regulated in the neonatal gland, might contribute to the hyporesponsiveness of the adrenal cortex characteristic of this developmental period. We have also observed in the adult gland a marked up‐regulation of enzymes involved in NAD(P)H production, thus providing the reducing power necessary for steroid hormone biosynthesis.     

Protective immunosurveillance and therapeutic antitumor activity of gammadelta T cells demonstrated in a mouse model of prostate cancer

In contrast to Ag-specific alphabeta T cells, gammadelta T cells can kill malignantly transformed cells in a manner that does not require the recognition of tumor-specific Ags. Although such observations have contributed to the emerging view that gammadelta T cells provide protective innate immunosurveillance against certain malignancies, particularly those of epithelial origin, they also provide a rationale for developing novel clinical approaches to exploit the innate antitumor properties of gammadelta T cells for the treatment of cancer. Using TRAMP, a transgenic mouse model of prostate cancer, proof-of-concept studies were performed to first establish that gammadelta T cells can indeed provide protective immunosurveillance against spontaneously arising mouse prostate cancer. TRAMP mice, which predictably develop prostate adenocarcinoma, were backcrossed with gammadelta T cell-deficient mice (TCRdelta(-/-) mice) yielding TRAMP x TCRdelta(-/-) mice, a proportion of which developed more extensive disease compared with control TRAMP mice. By extension, these findings were then used as a rationale for developing an adoptive immunotherapy model for treating prostate cancer. Using TRAMP-C2 cells derived from TRAMP mice (C57BL/6 genetic background), disease was first established in otherwise healthy wild-type C57BL/6 mice. In models of localized and disseminated disease, tumor-bearing mice treated i.v. with supraphysiological numbers of syngeneic gammadelta T cells (C57BL/6-derived) developed measurably less disease compared with untreated mice. Disease-bearing mice treated i.v. with gammadelta T cells also displayed superior survival compared with untreated mice. These findings provide a biological rationale for clinical trials designed to adoptively transfer ex vivo expanded autologous gammadelta T cells for the treatment of prostate cancer.     

Evolutionary Conservation of the Structure and Expression of Alternatively Spliced Ultrabithorax Isoforms from Drosophila

In Drosophila melanogaster, alternatively spliced mRNAs from the homeotic gene Ultrabithorax (Ubx) encode a family of structurally distinct homeoprotein isoforms. The developmentally regulated expression patterns of these isoforms suggest that they have specialized stage- and tissue-specific functions. To evaluate the functional importance of UBX isoform diversity and gain clues to the mechanism that regulates processing of Ubx RNAs, we have investigated whether the Ubx RNAs of other insects undergo similar alternative splicing. We have isolated and characterized Ubx cDNA fragments from D. melanogaster, Drosophila pseudoobscura, Drosophila hydei and Drosophila virilis, species separated by as much as 60 million years of evolution, and have found that three aspects of Ubx RNA processing have been conserved. (1) These four species exhibit identical patterns of optional exon use in a region adjacent to the homeodomain. (2) These four species produce the same family of UBX protein isoforms with identical amino acid sequences in the optional exons, even though the common amino-proximal region has undergone substantial divergence. The nucleotide sequences of the optional exons, including third positions of rare codons, have also been conserved strongly, suggesting functional constraints that are not limited to coding potential. (3) The tissue- and stage-specific patterns of expression of different UBX isoforms are identical among these Drosophila species, indicating that the developmental regulation of the alternative splicing events has also been conserved. These findings argue for an important role of alternative splicing in Ubx function. We discuss the implications of these results for models of UBX protein function and the mechanism of alternative splicing.     

Solution- and solid-phase synthesis and anti-HIV activity of maslinic acid derivatives containing amino acids and peptides

Maslinic acid (1) has been coupled at C-28 with several α- and ω-amino acids by using solution- and solid-phase synthetic procedures. Twelve derivatives (2–13) with a single amino acid residue were prepared in solution phase, whereas a dipeptide (14), a tripeptide (15), and a series of conjugate dipeptides (16–24) were synthesized in solid phase. The anti-HIV activity of these compounds was assessed on MT-2 cells infected with viral clones carrying the luciferase gene as a reporter. While in maslinic acid (1) were present both cytotoxic and antiviral activities, only the derivatives 13 and 24 showed anti-HIV-1 activity and therefore represent a novel class of anti-HIV-1 compounds.     

Transfection of Streptococcus pneumoniae with bacteriophage DNA.

It was possible to transfect Streptococcus pneumoniae with DNA obtained from a newly isolated bacteriophage, diplophage-4 (Dp-4). Optimal frequency of transfection (0.9%) required the use of a nuclease-defective mutant; with wild-type bacteria, the transfection frequency was about 100-fold lower. Transfection requires physiological conditions that appear to be similar to the competent state needed for genetic transformation (A. Tomasz, J. Bacteriol. 91:1050--1061, 1966).     

PPAR gamma 2 prevents lipotoxicity by controlling adipose tissue expandability and peripheral lipid metabolism

Peroxisome proliferator activated receptor gamma 2 (PPARg2) is the nutritionally regulated isoform of PPARg. Ablation of PPARg2 in the ob/ob background, PPARg2^−/− Lep^ob/Lep^ob (POKO mouse), resulted in decreased fat mass, severe insulin resistance, β-cell failure, and dyslipidaemia. Our results indicate that the PPARg2 isoform plays an important role, mediating adipose tissue expansion in response to positive energy balance. Lipidomic analyses suggest that PPARg2 plays an important antilipotoxic role when induced ectopically in liver and muscle by facilitating deposition of fat as relatively harmless triacylglycerol species and thus preventing accumulation of reactive lipid species. Our data also indicate that PPARg2 may be required for the β-cell hypertrophic adaptive response to insulin resistance. In summary, the PPARg2 isoform prevents lipotoxicity by (a) promoting adipose tissue expansion, (b) increasing the lipid-buffering capacity of peripheral organs, and (c) facilitating the adaptive proliferative response of β-cells to insulin resistance.     

Viral Diversity,Prey Preference,and Bartonella Prevalence in Desmodus rotundus in Guatemala

EcoHealth - Certain bat species serve as natural reservoirs for pathogens in several key viral families including henipa-, lyssa-, corona-, and filoviruses, which may pose serious threats to human...