Transient knock-down of kcna2 reduces sleep in larval zebrafish.

In the current study we set out to determine the effects of morpholino oligonucleotide (MO) knock-down of kcna2 on sleep-wake cycles in zebrafish. The results were compared to a non-overlapping MO injection, Dec2, who's mutant is also linked with a short sleep phenotype. Four groups of fish were used in the experiment: naïve fish, and fish injected with either control, kcna2, or Dec2 MO. All groups underwent 24-h behavioral monitoring of sleep-wake cycles at four and seven days-post-fertilization (dpf). First, we established an immobility dependent, sleep related, increase in arousal thresholds at both 4 and 7 dpf. Secondly, we show that kcna2 MO injected fish exhibit significantly less sleep behavior than controls and naïve fish, whereas Dec2 MO injections had similar but less severe effects. Finally, using kcna2 MO injected fish only, we turn to local field recordings at the level of the telencephalon and tectum opticum and rule out that the knock-down resulted in a non-specific increase in neural excitability that would mask sleep behavior.

The role of Th17/Tc17 peripheral blood T cells in psoriasis and their positive therapeutic response.

It is known that NB-UVB therapy can suppress a broad range of immune cells, but the additional effect of bathing in geothermal seawater still remains unclear. To study the influence of treatment on the expression of circulating immune cells contributing to the pathogenesis of psoriasis, six patients with psoriasis were treated with bathing in geothermal seawater two times daily combined with NB-UVB five times/week for 2 weeks and six patients were treated with NB-UVB therapy three times/week for 8 weeks. Disease severity (Psoriasis Area and Severity Index, PASI), chemokines, inflammatory cytokines, T cells and Toll-like receptors in the blood and skin samples were evaluated on enrolment (W0) and at 1 (W1), 3 (W3) and 8 (W8) weeks. Compared with healthy controls, psoriasis patients with active disease had significantly higher proportion of peripheral CLA+ T cells expressing CCR10 and CD103 and T cells with both Th1/Tc1 (CD4+/CD8+ IFN-γ+ or TNF-α+ cells) and Th17/Tc17 (CD4+CD45R0+IL-23R+, CD4+/CD8+ IL-17A+ or IL-22+ cells) phenotypes. Both treatments gave a significant clinical effect; however, bathing in geothermal seawater combined with NB-UVB therapy was more effective than NB-UVB therapy alone. This clinical improvement was reflected by a reduction in circulating CLA+ peripheral blood T cells and by a decreased Th1/Th17 and Tc1/Tc17 inflammatory response. These findings suggest that the inflammatory response in psoriasis is predominantly driven by both CD4+ and CD8+ skin-homing tissue retaining T cells of the Th17/Tc17 lineages.

H2-rich fluids from serpentinization: geochemical and biotic implications.

Metamorphic hydration and oxidation of ultramafic rocks produces serpentinites, composed of serpentine group minerals and varying amounts of brucite, magnetite, and/or FeNi alloys. These minerals buffer metamorphic fluids to extremely reducing conditions that are capable of producing hydrogen gas. Awaruite, FeNi3, forms early in this process when the serpentinite minerals are Fe-rich. Olivine with the current mantle Fe/Mg ratio was oxidized during serpentinization after the Moon-forming impact. This process formed some of the ferric iron in the Earth's mantle. For the rest of Earth's history, serpentinites covered only a small fraction of the Earth's surface but were an important prebiotic and biotic environment. Extant methanogens react H2 with CO2 to form methane. This is a likely habitable environment on large silicate planets. The catalytic properties of FeNi3 allow complex organic compounds to form within serpentinite and, when mixed with atmospherically produced complex organic matter and waters that circulated through basalts, constitutes an attractive prebiotic substrate. Conversely, inorganic catalysis of methane by FeNi3 competes with nascent and extant life.