Prediction and preliminary validation of oncogene regulation by miRNAs

Background  

MicroRNAs (miRNAs) are one of the most abundant groups of regulatory genes in multicellular organisms, playing important roles in many fundamental cellular processes. More than four hundred miRNAs have been identified in humans and the deregulation of miRNA expression has been also shown in many cancers. Despite the postulated involvement of miRNAs in tumourigenesis, there are only a few examples where an oncogene or a tumour suppressor has been identified as a miRNA target.     

Pulmonary hypertension associated with sarcoidosis

Pulmonary involvement is common in sarcoidosis, an immune-mediated inflammatory disorder that is characterized by non-caseating granulomas in tissue. Sarcoid patients with advanced pulmonary disease, especially end-stage pulmonary fibrosis, risk developing pulmonary hypertension (World Health Organization group III pulmonary hypertension secondary to hypoxic lung disease). Increased levels of endothelin (ET)-1 in plasma and bronchoalveolar lavage of some sarcoid patients suggest that ET-1 may be driving pulmonary fibrosis and sarcoidosis-associated pulmonary hypertension. Although a relationship between raised levels of ET-1 and clinical phenotype is yet to be identified, early evidence from studies of ET-1 blockade with drugs such as bosentan is encouraging. Such therapy possibly could be combined with standard anti-inflammatory agents to improve outcome.     

Transient activation of tumor-associated T-effector/memory cells promotes tumor eradication via NK-cell recruitment: minimal role for long-term T-cell immunity in cure of metastatic disease

Local delivery of IL-12 and GM-CSF to advanced primary tumors results in T- and NK-cell-dependent cure of disseminated disease in a murine spontaneous lung metastasis model. Post-therapy functional dynamics of cytotoxic T- and NK-cells were analyzed in primary and metastatic tumors to determine the specific roles of each subset in tumor eradication. Time-dependent depletion of CD8+ T and NK-cells demonstrated that CD8+ T-cells were critical to eradication of metastatic tumors within 3 days of treatment, but not later. In contrast, NK-cells were found to be essential to tumor regression for at least 10 days after cytokine delivery. Analysis of tumor-infiltrating lymphocyte populations in post-therapy primary tumors demonstrated that treatment resulted in the activation of tumor-associated CD8+ T-cells within 24 h as determined by IFNγ and perforin production. T-cell activity peaked between days 1 and 3 and subsided rapidly thereafter. Activation was not accompanied with an increase in cell numbers suggesting that treatment mobilized pre-existing T-effector/memory cells without inducing proliferation. In contrast, therapy resulted in a ≥3-fold enhancement of both the quantity and the cytotoxic activity of NK-cells in primary and metastatic tumors on day 3 post-therapy. NK-cell activity was also transient and subsided to pre-therapy levels by day 5. Depletion of CD4+ and CD8+ T-cells prior to treatment completely abrogated NK-cell infiltration into primary and metastatic tumors demonstrating the strict dependence of NK-cell recruitment on pre-existing T-effector/memory cells. Treatment failed to induce significant NK-cell infiltration in IFNγ-knockout mice establishing the central role of IFNγ in NK-cell chemotaxis to tumors. These data show that transient activation of tumor-associated T-effector/memory and NK-cells, but not long-term CD8+ T-cell responses, are critical to suppression of metastatic disease in this model; and reveal a novel role for pre-existing adaptive T-cell immunity in the recruitment of innate effectors to tumors. This work was supported by NIH/NCI grant R01-CA100656-01A1 to N.K.E.     

Foot mucus is a good source for non-destructive genetic sampling in Polyplacophora

A non-destructive method for collecting samples for DNA analysis from the mucus of molluscs was successfully adapted for use with the genus Ischnochiton. DNA was extracted using a Chelex-based method and the COI subunit of the mtDNA was amplified and sequenced. Sequences from the mucus were crosschecked against sequences from the foot tissue of the same animal and were found to be identical. This method provides a non-destructive way of carrying out larger studies of the genetics of rare organisms and may be of general use for genetic-based field studies of molluscs.     

Crops and agriculture during the Iron Age and late antiquity in Cerdanyola del Vallès (Catalonia,Spain)

Various sites in the valley of the Sant Cugat stream in Cerdanyola del Vallès (Catalonia) were subject to systematic archaeobotanical sampling to obtain an overview of the crops and agriculture of the area during the Iron Age and late antiquity. In all cases, the most numerous taxa were crop plants. Among these, cereals were clearly predominant at all sites investigated, especially Hordeum vulgare var. vulgare (hulled barley) and Triticum aestivum/durum (bread or macaroni wheat), both in numbers and frequency. Other cereals, such as Triticum dicoccum (emmer) or Setaria italica (foxtail bristle-grass), were regularly present in considerably lower numbers but in fairly high frequencies. Pulses were much less numerous, although their presence increases in terms of frequency. Among them, clearly the best represented was Lens culinaris (lentil). The results show that the agriculture in the period considered was principally based on winter cereals, with a gradual substitution of hulled barley by bread/hard wheat, accompanied by other cereals of minor importance, led by Triticum dicoccum (emmer), and pulses. The appearance of Vitis (grapevine) in the Iberian period is one of the important characteristics of agriculture in the Iberian world. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Extraction and purification of an unusual phycoerythrin in a terrestrial desiccation tolerant cyanobacterium <Emphasis Type="BoldItalic">Lyngbya arboricola</Emphasis>

Presence and stability of an unusual phycoerythrin (PE) characteristically similar to R-PE are described in a terrestrial, desiccation-tolerant cyanobacterium, Lyngbya arboricola. Extraction and purification of the PE by using acetone precipitation, gel filtration and ion-exchange chromatography resulted in achieving a purity index (A₅₆₀/A₂₈₀) of up to 5.2. SDS-PAGE of the PE showed presence of 18 kDa, 20 kDa and 32 kDa bands corresponding to α, β and γ subunits of R-PE without any other contaminating phycobiliproteins (PBPs). The absorption spectrum of the PE was distinguished by two major peaks at 499 and 559 nm. The maximum fluorescence emission at room temperature was 578 nm. Spectroscopic and electrophoresis characteristics of PE in the dry mats on storage at 25 ± 1°C over silica gel for 2 years remained almost unaffected. Quantitatively, storage stability of the PE was in the order of dry mats > lyophilized > liquid state and the impact of temperature on loss of PE was in the order of 25°C > −20°C > 4°C. The relevance of L. arboricola for production of stable unusual PE is discussed.     

Frequency of micronuclei in 4–8 cell mouse embryos generated after maternal gamma-irradiation in the presence and in the absence of vitamin C

The objective of this investigation was to evaluate the frequency of chromosomal aberrations expressed as micronuclei (MN) in 4–8 cell embryos generated by gamma-irradiation of female mice in the absence and in the presence of vitamin C. Female NMRI mice were whole body exposed to 4 Gy gamma-irradiation after intraperitoneal (i.p.) injection of pregnant mare’s serum gonadotrophin (PMSG) followed by injection of human chorionic gonadotrophin (HCG) and mating with non-irradiated NMRI male mice. Pregnant animals were sacrificed and embryos flushed from the oviducts and fixed on slides. Cells were treated for MN observation using standard method. To investigate the protective effect of vitamin C (ascorbic acid) on the frequency of MN, 100 mg/kg vitamin C was i.p. injected 1 h before irradiation. Results show that the frequency of MN generated in the embryos of irradiated mother compared to those of control in the non-irradiated group increased dramatically (P < 0.001). Frequency of MN in embryos generated in irradiated female mice treated with vitamin C dramatically and statistically decreased relative to the frequency observed in the irradiation only group (P < 0.001). This decrease returned the combined treatment group to a level that was not statistically different from the controls (P > 0.05). Thus, irradiation of preovulatory stage oocytes leads to stable chromosome abnormalities expressed as micronuclei in successive preimplantation embryos. Vitamin C reduces these clastogenic effects of radiation in preovulatory oocytes and thus the reduced frequency of MN in embryos is probably due to its antioxidation and radical scavenging properties.     

Observations on the length of the intestinal tract of African <Emphasis Type="Italic">Loxodonta africana</Emphasis> (Blumenbach 1797) and Asian elephants <Emphasis Type="Italic">Elephas maximus</Emphasis> (Linné 1735)

The digestive tract of elephants is surprisingly short compared to other herbivorous mammals. However, measurements relating the length of the intestine to the body mass of the respective individual are rare. In this study, we report such data for an African elephant and an Asian elephant. Our data support the hypothesis that Asian elephants have a longer intestinal tract than their African counterparts. These findings are in accord with the observation of longer retention times and higher digestion coefficients in Asian as compared to African elephants. This difference between the species could be the reflection of slightly different ecological niches, with Asian elephants adapted to a natural diet with a higher proportion of grass.     

Sucrose and starch catabolism in the anther of <Emphasis Type="Italic">Lilium</Emphasis> during its development: a comparative study among the anther wall,locular fluid and microspore/pollen fractions

In order to better understand the various pathways of sucrose and starch catabolism in the anther of lily (Lilium hybrida var. “Enchantment”), invertase (EC 3.2.1.26) and amylase (EC 3.2.1.1, EC 3.2.1.2) activities were measured separately in different fractions (anther wall, locular fluid and microspore/pollen) and correlated with the sugar content during anther development. Our findings showed significant differences among the fractions analyzed, suggesting that the regulation of sucrose and starch catabolism could follow distinct pathways in each fraction. Glucose and fructose amounts progressively decreased from anther wall to fluid and from fluid to microspore/pollen. Thus, the developing pollen could act as a sink for the carbohydrates that reach the anther. In this sense, cell wall-bound invertases seem to play a major role in soluble sugar partitioning in the different fractions of the anther. Sucrose concentration was found to be substantially higher in the locular fluid than in the other fractions, indicating a probable site for storage. On the other hand, the anther wall tissues could have a buffering function, storing nutrient surplus in starch grains and thus regulating the availability of soluble sugars in the whole anther. All these results proved the advantages of the experimental model proposed here, as well as its usefulness to investigate sugar metabolism in Lilium anthers.