Cooperative functions of the reaper and head involution defective genes in the programmed cell death of Drosophila central nervous system midline cells

In Drosophila, the chromosomal region 75C1–2 contains at least three genes, reaper (rpr), head involution defective (hid), and grim, that have important functions in the activation of programmed cell death. To better understand how cells are killed by these genes, we have utilized a well defined set of embryonic central nervous system midline cells that normally exhibit a specific pattern of glial cell death. In this study we show that both rpr and hid are expressed in dying midline cells and that the normal pattern of midline cell death requires the function of multiple genes in the 75C1–2 interval. We also utilized the P[UAS]/P[Gal4] system to target expression of rpr and hid to midline cells. Targeted expression of rpr or hid alone was not sufficient to induce ectopic midline cell death. However, expression of both rpr and hid together rapidly induced ectopic midline cell death that resulted in axon scaffold defects characteristic of mutants with abnormal midline cell development. Midline-targeted expression of the baculovirus p35 protein, a caspase inhibitor, blocked both normal and ectopic rpr- and hid-induced cell death. Taken together, our results suggest that rpr and hid are expressed together and cooperate to induce programmed cell death during development of the central nervous system midline.

Bok is a pro-apoptotic Bcl-2 protein with restricted expression in reproductive tissues and heterodimerizes with selective anti-apoptotic Bcl-2 family members

In the intracellular death program, hetero- and homodimerization of different anti- and pro-apoptotic Bcl-2-related proteins are critical in the determination of cell fate. From a rat ovarian fusion cDNA library, we isolated a new pro-apoptotic Bcl-2 gene, Bcl-2-related ovarian killer (Bok). Bok had conserved Bcl-2 homology (BH) domains 1, 2, and 3 and a C-terminal transmembrane region present in other Bcl-2 proteins, but lacked the BH4 domain found only in anti-apoptotic Bcl-2 proteins. In the yeast two-hybrid system, Bok interacted strongly with some (Mcl-1, BHRF1, and Bfl-1) but not other (Bcl-2, Bcl-xL, and Bcl-w) anti-apoptotic members. This finding is in direct contrast to the ability of other pro-apoptotic members (Bax, Bak, and Bik) to interact with all of the anti-apoptotic proteins. In addition, negligible interaction was found between Bok and different pro-apoptotic members. In mammalian cells, overexpression of Bok induced apoptosis that was blocked by the baculoviral-derived cysteine protease inhibitor P35. Cell killing induced by Bok was also suppressed following coexpression with Mcl-1 and BHRF1 but not with Bcl-2, further indicating that Bok heterodimerized only with selective anti-apoptotic Bcl-2 proteins. Northern blot analysis indicated that Bok was highly expressed in the ovary, testis and uterus. In situ hybridization analysis localized Bok mRNA in granulosa cells, the cell type that underwent apoptosis during follicle atresia. Identification of Bok as a new pro-apoptotic Bcl-2 protein with restricted tissue distribution and heterodimerization properties could facilitate elucidation of apoptosis mechanisms in reproductive tissues undergoing hormone-regulated cyclic cell turnover.

Baculovirus inhibitors of apoptosis (IAPs) block activation of Sf-caspase-1

We have investigated the ability of Sf-caspase-1 and two mammalian caspases, caspase-1 and caspase-3, to induce apoptosis in Spodoptera frugiperda Sf-21 insect cells. While the transient expression of the pro-Sf-caspase-1 did not induce apoptosis, expression of the pro-domain deleted form, p31, or coexpression of the two subunits of mature Sf-caspase-1, p19 and p12, induced apoptosis in Sf-21 cells. The behavior of Sf-caspase-1 resembled that of the closely related mammalian caspase, caspase-3, and contrasted with that of the mammalian caspase-1, the pro-form of which was active in inducing apoptosis in Sf-21 cells. The baculovirus caspase inhibitor P35 blocked apoptosis induced by active forms of all three caspases. In contrast, members of the baculovirus inhibitor of apoptosis (IAP) family failed to block active caspase-induced apoptosis. However, during viral infection, expression of OpIAP or CpIAP blocked the activation of pro-Sf-caspase-1 and the associated induction of apoptosis. Thus, the mechanism by which baculovirus IAPs inhibit apoptosis is distinct from the mechanism by which P35 blocks apoptosis and involves inhibition of the activation of pro-caspases like Sf-caspase-1.

Genetic variation in vulnerability to the behavioral effects of neonatal hippocampal damage in rats.

We explored how two independent variables, one genetic (i.e., specific rat strains) and another environmental (i.e., a developmental excitotoxic hippocampal lesion), contribute to phenotypic variation. Sprague-Dawley (SD), Fischer 344 (F344), and Lewis rats underwent two grades of neonatal excitotoxic damage: small and large ventral hippocampal (SVH and LVH) lesions. Locomotion was tested before puberty [postnatal day 35 (P35)] and after puberty (P56) following exposure to a novel environment or administration of amphetamine. The behavioral effects were strain- and lesion-specific. As shown previously, SD rats with LVH lesions displayed enhanced spontaneous and amphetamine-induced locomotion as compared with controls at P56, but not at P35. SVH lesions in SD rats had no effect at any age. In F344 rats with LVH lesions, enhanced spontaneous and amphetamine-induced locomotion appeared early (P35) and was exaggerated at P56. SVH lesions in F344 rats resulted in a pattern of effects analogous to LVH lesions in SD rats--i.e., postpubertal onset of hyperlocomotion (P56). In Lewis rats, LVH lesions had no significant effect on novelty- or amphetamine-induced locomotion at any age. These data show that the degree of genetic predisposition and the extent of early induced hippocampal defect contribute to the particular pattern of behavioral outcome. These results may have implications for modeling interactions of genetic and environmental factors involved in schizophrenia, a disorder characterized by phenotypic heterogeneity, genetic predisposition, a developmental hippocampal abnormality, and vulnerability to environmental stress.

Differential modulation of Th1- and Th2-related cytokine mRNA expression by a synthetic peptide homologous to a conserved domain within retroviral envelope protein.

The influence of a synthetic retroviral peptide, CKS-17, on T helper type 1 (Th1)- or Th2-related cytokines was investigated in human blood mononuclear cells. Cells were stimulated with staphylococcal enterotoxin A, anti-CD3 plus anti-CD28 monoclonal antibodies, or lipopolysaccharide to induce cytokine mRNA. mRNA was detected by a reverse transcription-polymerase chain reaction or Northern blot analysis. CKS-17 down-regulated stimulant-induced mRNA accumulation for interferon gamma (IFN-gamma), interleukin (IL)-2, and p40 heavy and p35 light chains of IL-12, a cytokine that mediates development of Th1 response. CKS-17 up-regulated stimulant-induced mRNA accumulation of IL-10 and did not suppress Th2-related cytokine (IL-4, IL-5, IL-6, or IL-13) mRNA expression. A reverse sequence of CKS-17 peptide, used as a control, showed no such action. Anti-human IL-10 monoclonal antibody blocked ability of CKS-17 to inhibit mRNA accumulation for IFN-gamma but not the CKS-17 suppressive activity of IL-12 p40 heavy chain mRNA. Thus, CKS-17-mediated suppression of IFN-gamma mRNA expression is dependent upon augmentation of IL-10 production by CKS-17. This conserved component of several retroviral envelope proteins, CKS-17, may act as an immunomodulatory epitope responsible for cytokine dysregulation that leads to suppression of cellular immunity.

Our foreign relations : showing present perils from England and France, the nature and conditions of intervention by mediation, and also by recognition, the impossibility of any recognition of a new power with slavery as a corner-stone, and the wrongful concession of ocean belligerency. Speech of Hon. Charles Sumner, before the citizens of New York, at the Cooper Institute, Sept. 10, 1863.

Mode of access: Internet.

Memoirs of a young Greek lady; or, Madame Pauline Adelaide Alexandre Panam, versus His Most Serene Highness the reigning Prince of Saxe-Cobourg.

Translated by W. H. Ireland.

The Republic

"A monthly magazine, devoted to the dissemination of political information."

IL10 and IL12B polymorphisms each influence IL-12p70 secretion by dendritic cells in response to LPS

Dendritic cells (DC) are the main producers of the cytokine IL-12p70, through which they play a direct role in the development of IFN-gamma-secreting Th1 cells, costimulation of CTL differentiation and NK-cell activation. In contrast, IL-10, which is also produced by DC, negatively regulates IL-12 production. IL-12p70 production varies widely between individuals, and several polymorphisms in the gene encoding IL-12p40 (IL12B) have been identified that influence susceptibility and severity of infectious, autoimmune and neoplastic disease. Here we show that polymorphisms not only of IL12B, but also in the IL10 promoter, influence IL-12p70 secretion by monocyte-derived DC in response to LPS. Although IL12B promoter homozygotes were prone to making more IL-12p70, presence of the IL10 high genotype restricted IL-12p70 production in these individuals. These observations provide a further genetic control of IL-12p70 regulation and emphasize the complexity of production of this cytokine. They also suggest genotypes that might influence the outcome of DC immunotherapy.

Ácido ascórbico, betalaínas, e fenóis totais em ecótipos de Opuntia spp.

O género Opuntia spp. pertence à família Cactaceae, sendo a espécie Opuntia ficus-indica (OFI) a que tem maior importância económica. Em frutos de vinte populações provenientes de quatro espécies do género Opuntia spp. (OFI, O. robusta, O. dillenii and O. elata), com origem em Portugal, foram estudadas as características cromáticas, a acidez, o pH, o teor em sólidos solúveis totais (SST) e ainda os teores em ácido ascórbico (AA), betalaínas e fenóis totais (FT). As cultivares Italianas de OFI ‘Bianca’, ‘Gialla’ e ‘Rossa’ foram incluídas como termo de comparação. Os valores mais elevados de acidez foram registados nos frutos de O. dillenii e O. elata e os menores em OFI. Os frutos de O. dillenii apresentaram os teores mais elevados de betalaínas e FT, ao passo que as concentrações mais elevadas de AA foram registadas nos frutos de O. elata. Os ecótipos de OFI mostraram variação na concentração de compostos bioativos. Em OFI, a cv. de polpa vermelha ‘Rossa’ é a que apresenta maior concentração de betalaínas, seguida pelos ecótipos de polpa laranja e, finalmente, os ecótipos de polpa branca. Os valores mais elevados de FT foram encontrados nos ecótipos de polpa branca. O género Opuntia spp. é uma fonte de compostos bioativos, pelo que o consumo dos seus frutos representa uma boa forma de ingestão de compostos de elevado valor nutricional.