Preferential cell death of CD8+ effector memory (CCR7-CD45RA-) T cells by hydrogen peroxide-induced oxidative stress

T cells are used in many cell-based cancer treatments. However, oxidative stress that is induced during various chronic inflammatory conditions, such as cancer, can impair the immune system and have detrimental effects on T cell function. In this study, we have investigated the sensitivity of different human T cell subsets to H(2)O(2)-induced oxidative stress. We showed that central memory (CD45RA(-)CCR7(+)) and effector memory (CD45RA(-)CCR7(-)) T cells are more sensitive to H(2)O(2) as compared with naive (CD45RA(+)CCR7(+)) T cells. Furthermore, the study showed that CD8(+) effector memory T cells are more sensitive to low levels of H(2)O(2) (5 microM) compared with other types of T cells investigated. H(2)O(2)-exposed CD45RO(+) T cells showed mitochondrial depolarization prior to caspase 3 activity. Moreover, the pan-caspase inhibitor z-Val-Ala-Asp(OMe)-fluoromethylketone rescued cells from death. These experiments suggest that H(2)O(2)-induced cell death of CD45RO(+) T cells acts via the mitochondrial pathway and that caspase involvement is needed. This study suggests that oxidative stress in cancer patients can be disadvantageous for T cell-based adoptive cell transfer therapies, since effector memory T cells are the primary phenotype of the cells administered.     

Stat3 in resident macrophages as a repressor protein of inflammatory response

Inflammation is counterbalanced by anti-inflammatory cytokines such as IL-10, in which Stat3 mediates the signaling pathway. In this study, we demonstrate that resident macrophages, but not other cell types, are important targets of IL-10 in a murine model of acute peritonitis. Injection of thioglycollate i.p. induced a considerable number of neutrophils and macrophages in the peritoneum, which was significantly augmented in mice with a cell-type specific disruption of the Stat3 gene in macrophages and neutrophils (LysMcre/Stat3flox/- mice). The augmented leukocyte infiltration was accompanied by increased peritoneal levels of TNF-alpha, MIP-2, KC chemokine (KC), and MCP-1/CCL2. Stat3 was tyrosine phosphorylated in peritoneal resident macrophages as well as infiltrating leukocytes in the littermate controls, suggesting that Stat3 in either or both of these cells might play a regulatory role in inflammation. The peritoneal levels of TNF-alpha, MIP-2, KC, and MCP-1 were similarly elevated in LysMcre/Stat3flox/- mice rendered leukopenic by cyclophosphamide treatment as compared with the controls. Adoptive transfer of resident macrophages from LysMcre/Stat3flox/- mice into the control littermates resulted in increases in the peritoneal level of TNF-alpha, MIP-2, KC, and MCP-1 after i.p. injection of thioglycollate. Under these conditions, control littermates harboring LysMcre/Stat3flox/- macrophages exhibited an augmented leukocyte infiltration relative to those received control macrophages. Taken together, these data provide evidence that resident macrophages, but not other cell types, play a regulatory role in inflammation through a Stat3 signaling pathway. Stat3 in resident macrophages appears to function as a repressor protein in this model of acute inflammation.     

New series of potent delta-opioid antagonists containing the H-Dmt-Tic-NH-hexyl-NH-R motif

Heterodimeric compounds H-Dmt-Tic-NH-hexyl-NH-R (R = Dmt, Tic, and Phe) exhibited high affinity to δ- (K_iδ = 0.13–0.89 nM) and μ-opioid receptors (K_iμ = 0.38–2.81 nM) with extraordinary potent δ antagonism (pA₂ = 10.2–10.4). These compounds represent the prototype for a new class of structural homologues lacking μ-opioid receptor-associated agonism (IC₅₀ = 1.6–5.8 μM) based on the framework of bis-[H-Dmt-NH]-alkyl (Okada, Y.; Tsuda, Y.; Fujita, Y.; Yokoi, T.; Sasaki, Y.; Ambo, A.; Konishi, R.; Nagata, M.; Salvadori, S.; Jinsmaa, Y.; Bryant, S. D.; Lazarus, L. H. J. Med. Chem. 2003, 46, 3201), which exhibited both high μ affinity and bioactivity.     

Osteoblastic differentiation of monkey embryonic stem cells in vitro

Monkey embryonic stem (ES) cell is a useful tool for preclinical studies of regenerative medicine. In this paper, we investigated whether monkey ES cells can be differentiated into osteoblasts in vitro using factors known to promote osteogenesis. We prepared embryoid bodies (EB) in the presence of retinoic acid (RA) and subsequently differentiated in the medium containing either dexamethasone (DEX) or bone morphogenetic protein (BMP)-2 in addition to osteogenic supplements (OS), specifically ascorbic acid and beta-glycerophosphate. RA treatment during EB formation induced osteoblastic marker genes, such as collagen type 1, osteopontin, and Cbfa1. For the expression of osteocalcin, however, cultivation with medium containing either DEX or BMP-2 in addition to OS was required. These results showed that osteoblasts could be derived from monkey ES cells in vitro and BMP-2 + OS was effective to induce calcification.     

Compound‐specific isotope analysis of benthic foraminifer amino acids suggests microhabitat variability in rocky‐shore environments

The abundance and biomass of benthic foraminifera are high in intertidal rocky‐shore habitats. However, the availability of food to support their high biomass has been poorly studied in these habitats compared to those at seafloor covered by sediments. Previous field and laboratory observations have suggested that there is diversity in the food preferences and modes of life among rocky‐shore benthic foraminifera. In this study, we used the stable nitrogen isotopic composition of amino acids to estimate the trophic position, trophic niche, and feeding strategy of individual foraminifera species. We also characterized the configuration and structure of the endobiotic microalgae in foraminifera using transmission electron microscopy, and we identified the origin of endobionts based on nucleotide sequences. Our results demonstrated a large variation in the trophic positions of different foraminifera from the same habitat, a reflection of endobiotic features and the different modes of life and food preferences of the foraminifera. Foraminifera did not rely solely on exogenous food sources. Some species effectively used organic matter derived from endobionts in the cell cytoplasm. The high biomass and species density of benthic foraminifera found in intertidal rocky‐shore habitats are thus probably maintained by the use of multiple nitrogen resources and by microhabitat segregation among species as a consequence.     

Color pattern formation on the wing of a butterfly Pieris rapae. 2. Color determination and scale development

It has been shown that microcautery on the prospective apical black region of the early pupal forewing of a butterfly, Pieris rapae , causes alteration of the scale color on the adult wing and a delay in histogenesis of the pupal wing. From these results, it has been assumed that the developmental delay of scale cells in the pupal wing alters their developmental fate and the hypothesis that different color fates of scales are determined by differences in the developmental timetables between scale cells is proposed. In this study, we attempted to find the developmental timetables of individual scales expressing specific color to test this hypothesis. It was found that the holes on the upper surface of a scale become larger as they develop and the hole sizes of scales in the white region are always larger than in the black region on the same wings either during pupal period or after eclosion. This suggests that the scale hole size is a good index that reflects developmental rate of the scale and a difference in the hole size between adult scales is attributed to a difference in the developmental timetables when their ancestral scale precursor cells were in the pupal period. A comparison of the hole sizes between adult scales in different color regions suggested that normal white scales were in a more advanced state than were the black ones but white scales induced by microcautery were in a less advanced state than black ones on the same wing. This supports our hypothesis.     

The marine red alga Eucheuma serra J. Agardh, a high yielding source of two isolectins

Aqueous ethanolic extracts from five species of the genus Eucheuma (Rhodophyta) i.e. E. serra, E. amakusaensis, E. cottonii, E. gelatinae and E. denticulatum, were examined for hemagglutinating activity with vertebrate erythrocytes. All the extracts tested agglutinated trypsin-treated sheep and rabbit erythrocytes as well as untreated sheep erythrocytes. From the extract of E. serra, which exhibited the highest activity, a lectin was purified by precipitation with cold ethanol followed by gel filtration to exhibit a single band on SDS-PAGE. The yield was surprisingly as high as 1000 mg from 100 g powdered alga. The purified lectin was further separated into two isoforms, designated ESA-1(90 mg) and ESA-2 (890 mg), by ion exchange chromatography. Both lectins showed a single protein band with the same molecular weight of 29 000 on SDS-PAGE and differed from each other only in isoelectric point (pI 4.75 for ESA-1 and pI 4.95 for ESA-2). Biochemical studies revealed that both are monomeric proteins without a carbohydrate moiety. The hemagglutinating activities were stable over a wide pH range and at a relatively high temperature. The activities were inhibited by a number of glycoproteins, but not by any of the monosaccharides and disaccharides tested. The lectins showed strong mitogenic activities for mouse lymphocytes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Evidence that blue light induces betalain pigmentation in Portulaca callus

The wavelength range that activates betalain pigmentation has been studied following selection of light induelble betalain producing callus lines originating from Portulaca sp. Jewel seedlings. Light sources with different wave-lengths were used to irradiate the callus, resulting in blue light being effective in inducing betalain pigmentation. In addition, when UV light was combined with blue light, some calluses from this cell line showed high production of the pigment. This is a first report that betalain pigmentation in callus was induced by blue and blue/UV lights.Abbreviations UV ultra violet