Significant Variations in Double-Stranded RNA Levels in Cultured Skin Cells

Endogenous double-stranded RNA has emerged as a potent stimulator of innate immunity. Under physiological conditions, endogenous dsRNA is maintained in the cell nucleus or the mitochondria; however, if protective mechanisms are breached, it leaches into the cytoplasm and triggers immune signaling pathways. Ectopic activation of innate immune pathways is associated with various diseases and senescence and can trigger apoptosis. Hereby, the level of cytoplasmic dsRNA is crucial. We have enriched dsRNA from two melanoma cell lines and primary dermal fibroblasts, including a competing probe, and analyzed the dsRNA transcriptome using RNA sequencing. There was a striking difference in read counts between the cell lines and the primary cells, and the effect was confirmed by northern blotting and immunocytochemistry. Both mitochondria (10-20%) and nuclear transcription (80-90%) contributed significantly to the dsRNA transcriptome. The mitochondrial contribution was lower in the cancer cells compared to fibroblasts. The expression of different transposable element families was comparable, suggesting a general up-regulation of transposable element expression rather than stimulation of a specific sub-family. Sequencing of the input control revealed minor differences in dsRNA processing pathways with an upregulation of oligoadenylate synthase and RNP125 that negatively regulates the dsRNA sensors RIG1 and MDA5. Moreover, RT-qPCR, Western blotting, and immunocytochemistry confirmed the relatively minor adaptations to the hugely different dsRNA levels. As a consequence, these transformed cell lines are potentially less tolerant to interventions that increase the formation of endogenous dsRNA.

20-State Molecular Switch in a Li@C60 Complex

A substantial potential advantage of industrial electric and thermoelectric devices utilizing endohedral metallofullerenes (EMFs) is their ability to accommodate metallic moieties inside their empty cavities. Experimental and theoretical studies have elucidated the merit of this extraordinary feature with respect to developing electrical conductance and thermopower. Published research studies have demonstrated multiple state molecular switches initiated with 4, 6, and 14 distinguished switching states. Through comprehensive theoretical investigations involving electronic structure and electric transport, we report 20 molecular switching states that can be statistically recognized employing the endohedral fullerene Li@C₆₀ complex. We propose a switching technique that counts on the location of the alkali metal that encapsulates inside a fullerene cage. The 20 switching states correspond to the 20 hexagonal rings that the Li cation energetically prefers to reside close to. We demonstrate that the multiswitching feature of such molecular complexes can be controlled by taking advantage of the off-center displacement and charge transfer from the alkali metal to the C₆₀ cage. The most energetically favorable optimization suggests 1.2-1.4 Å off-center displacement, and Mulliken, Hirshfeld, and Voronoi simulations articulate that the charge migrates from the Li cation to C₆₀ fullerene; however, the amount of the charge transferred depends on the nature and location of the cation within the complex. We believe that the proposed work suggests a relevant step toward the practical application of molecular switches in organic materials.

Quantum Interference and Contact Effects in the Thermoelectric Performance of Anthracene-Based Molecules

We report on the single-molecule electronic and thermoelectric properties of strategically chosen anthracene-based molecules with anchor groups capable of binding to noble metal substrates, such as gold and platinum. Specifically, we study the effect of different anchor groups, as well as quantum interference, on the electric conductance and the thermopower of gold/single-molecule/gold junctions and generally find good agreement between theory and experiments. All molecular junctions display transport characteristics consistent with coherent transport and a Fermi alignment approximately in the middle of the highest occupied molecular orbital/lowest unoccupied molecular orbital gap. Single-molecule results are in agreement with previously reported thin-film data, further supporting the notion that molecular design considerations may be translated from the single- to many-molecule devices. For combinations of anchor groups where one binds significantly more strongly to the electrodes than the other, the stronger anchor group appears to dominate the thermoelectric behavior of the molecular junction. For other combinations, the choice of electrode material can determine the sign and magnitude of the thermopower. This finding has important implications for the design of thermoelectric generator devices, where both n- and p-type conductors are required for thermoelectric current generation.

Key features of the environment promoting liver cancer in the absence of cirrhosis

The prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC) is rising, even in the absence of cirrhosis. We aimed to develop a murine model that would facilitate further understanding of NAFLD-HCC pathogenesis. A total of 144 C3H/He mice were fed either control or American lifestyle (ALIOS) diet, with or without interventions, for up to 48 weeks of age. Gross, liver histology, immunohistochemistry (IHC) and RNA-sequencing data were interpreted alongside human datasets. The ALIOS diet promoted obesity, elevated liver weight, impaired glucose tolerance, non-alcoholic fatty liver disease (NAFLD) and spontaneous HCC. Liver weight, fasting blood glucose, steatosis, lobular inflammation and lipogranulomas were associated with development of HCC, as were markers of hepatocyte proliferation and DNA damage. An antioxidant diminished cellular injury, fibrosis and DNA damage, but not lobular inflammation, lipogranulomas, proliferation and HCC development. An acquired CD44 phenotype in macrophages was associated with type 2 diabetes and NAFLD-HCC. In this diet induced NASH and HCC (DINAH) model, key features of obesity associated NAFLD-HCC have been reproduced, highlighting roles for hepatic steatosis and proliferation, with the acquisition of lobular inflammation and CD44 positive macrophages in the development of HCC-even in the absence of progressive injury and fibrosis.