4-Hydroxyhexenal and 4-hydroxynonenal are mediators of the anti-cachectic effect of n-3 and n-6 polyunsaturated fatty acids on human lung cancer cells

Cachexia, the most severe paraneoplastic syndrome, occurs in about 80% of patients with advanced cancer; it cannot be reverted by conventional, enteral, or parenteral nutrition. For this reason, nutritional interventions must be based on the use of substances possessing, alongside nutritional and energetic properties, the ability to modulate production of the pro-inflammatory factors responsible for the metabolic changes characterising cancer cachexia. In light of their nutritional and anti-inflammatory properties, polyunsaturated fatty acids (PUFAs), and in particular n-3, have been investigated for treating cachexia; however, the results have been contradictory. Since both n-3 and n-6 PUFAs can affect cell functions in several ways, this research investigated the possibility that the effects of both n-3 and n-6 PUFAs could be mediated by their major aldehydic products of lipid peroxidation, 4-hydroxyhexenal (HHE) and 4-hydroxynonenal (HNE), and by their anti-inflammatory properties. An "in vitro" cancer cachexia model, consisting of human lung cancer cells (A427) and murine myoblasts (C2C12), was used. The results showed that: 1) both n-3 and n-6 PUFAs reduced the growth of lung cancer cells without causing cell death, increased lipid peroxidation and Peroxisome Proliferator-Activated Receptor (PPAR)α, and decreased TNFα; 2) culture medium conditioned by A427 cells grown in the absence of PUFAs blocked myosin production and the differentiation of C2C12 muscle cells; conversely, muscle cells grown in culture medium conditioned by the same cells in the presence of PUFAs showed myosin expression and formed myotubes; 3) adding HHE or HNE directly to C2C12 cells maintained in culture medium conditioned by A427 cells in the absence of PUFAs stimulated myosin production and myotube formation; 4) putative consensus sequences for (PPARs) have been found in genes encoding fast isoforms of myosin heavy chain, by a bioinformatics approach. The overall results show, first, the ability of both n-3 and n-6 PUFAs and their lipid peroxidation products to prevent the blocking of myosin expression and myotube formation caused in C2C12 cells by medium conditioned by human lung tumour cells. The C2C12 cell differentiation can be due to direct effect of lipid peroxidation products, as evidenced by treating C2C12 cells with HHE and HNE, and to the decrease of pro-inflammatory TNFα in A427 cell culture medium. The presence of consensus sequences for PPARs in genes encoding the fast isoforms of myosin heavy chain suggests that the effects of PUFAs, HHE, and HNE are PPAR-mediated.

Cytokines Involved in the Pathophysiology of IgE Response

Recent data in both mouse and human systems have clearly indicated that IL-4 plays an essential role in the induction of IgE response, whereas IFN-γ exerts an opposite effect on this phenomenon. However, IL-4 alone is unable to induce IgE synthesis. A prior membrane contact signal delivered by activated T cells is required by B cells to synthesize IgE in response to IL-4. A cognate interaction between B and T cells producing IL-4 (but not IFN-γ) is optimal for induction of IgE synthesis. However, when such IL-4 producing T cells are activated, they may provide B cells with a membrane signal, through a non-cognate interaction, which also results in induction of IgE synthesis. Other cytokines, such as IL-2 and IL-6, play an auxiliary role in IL-4 dependent IgE production.

Analyses at the clonal level of the profile of cytokine production by helper T cells have shown that imbalances between IL-4 and IFN-γ producing T cells can be detected in patients with hyperproduction of IgE. In children with hyper-IgE syndrome a strong reduction of circulating T cells able to produce IFN-γ (and TNF-α) was found, whereas both, reduction of IFN-γ-producing and increase of IL-4 producing T cells were found in patients with parasitic infestation. In allergic inflammatory infiltrates, such as those found in vernal conjuctivitis, helper T cells able to produce IL-4 and to induce IgE synthesis accounted for the large majority of infiltrating T cells. It is reasonable to suggest that systemic or microenvironmental alterations of the balance between IL-4- and IFN-γ-producing T cells may be involved, at least in part, in the pathophysiology of the increased igE response occurring in a number of human diseases.

Cytokines and Thyroid Autoimmunity

Cytokines may play important roles in the development and perpetuation of autoimmunity. In this paper are briefly reviewed selected data on the relationship between cytokines and thyroid autoimmune diseases (AITD), which represent a typical example of organ-specific autoimmune endocrinopathy. The availability of high efficiency T-cell cloning techniques recently allowed the phenotipic and functional characterization of T lymphocytes derived from thyroid infiltrates of patients with Graves' disease and Hashimoto's thyroiditis. A high prevalence of T cell clones with cytolytic potential and displaying increased γ-interferon production was observed in both diseases; in contrast, high tumor necrosis factor-α secretion was a peculiar characteristic of T-cell clones derived only from Hashimoto's infiltrates. The production of IL-4 by CD4 + T cell clones from AITD infiltrates was remarkably low, suggesting a quite homogeneous populations of Thl-type «inflammatory» T cells. This pattern of cytokine production by thyroid infiltrates may be important not only in triggering and/or maintaining thyroid autoimmune reaction, but could also modulate the expression of AITD by exerting direct functional effects on thyroid epithelial cells, as suggested by recent in vitro studies.

Time Dependence of the Electron and Positron Components of the Cosmic Radiation Measured by the PAMELA Experiment between July 2006 and December 2015

Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration, and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) until the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.

New upper limit on strange quark matter abundance in cosmic rays with the PAMELA space experiment

In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3}  GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.

Safranin-O dye in the ground state. A study by density functional theory, Raman, SERS and infrared spectroscopy

The analysis of ground state structural and vibrational properties of Safranin-O is presented. The experimental results, obtained by FTIR, Raman and SERS spectroscopy, are discussed in comparison to the results of DFT calculations carried out at the B3LYP/6-311+G(d,p) level of theory. The calculated spectra reproduce quite satisfactorily the experimental data. The calculated Safranin-O equilibrium structure and the assignment of the vibrational spectra are reported as well. From the changes between Raman and SERS spectra a model is presented for the interaction of Safranin-O with silver nanoparticles.