Characterization of an active LINE-1 in the naked mole-rat genome.

Naked mole-rats (NMRs, Heterocephalus glaber) are the longest-living rodent species. A reason for their long lifespan is pronounced cancer resistance. Therefore, researchers believe that NMRs have unknown secrets of cancer resistance and seek to find them. Here, to reveal the secrets, we noticed a retrotransposon, long interspersed nuclear element 1 (L1). L1s can amplify themselves and are considered endogenous oncogenic mutagens. Since the NMR genome contains fewer L1-derived sequences than other mammalian genomes, we reasoned that the retrotransposition activity of L1s in the NMR genome is lower than those in other mammalian genomes. In this study, we successfully cloned an intact L1 from the NMR genome and named it NMR-L1. An L1 retrotransposition assay using the NMR-L1 reporter revealed that NMR-L1 was active retrotransposon, but its activity was lower than that of human and mouse L1s. Despite lower retrotrasposition activity, NMR-L1 was still capable of inducing cell senescence, a tumor-protective system. NMR-L1 required the 3' untranslated region (UTR) for retrotransposition, suggesting that NMR-L1 is a stringent-type of L1. We also confirmed the 5' UTR promoter activity of NMR-L1. Finally, we identified the G-quadruplex structure of the 3' UTR, which modulated the retrotransposition activity of NMR-L1. Taken together, the data indicate that NMR-L1 retrotranspose less efficiently, which may contribute to the cancer resistance of NMRs

The DsbA-L gene is associated with respiratory function of the elderly via its adiponectin multimeric or antioxidant properties

Oxidative stress and inflammation play a key role in the age-related decline in the respiratory function. Adipokine in relation to the metabolic and inflammatory systems is attracting growing interest in the field of respiratory dysfunction. The present clinical and experimental studies investigated the role of the disulfide bond-forming oxidoreductase A-like protein (DsbA-L) gene, which has antioxidant and adiponectin multimeric (i.e. activation) properties, on the respiratory function of the elderly. We performed a retrospective longitudinal genotype-phenotype relationship analysis of 318 Japanese relatively elderly participants (mean age ± standard deviation: 67.0 ± 5.8 years) during a health screening program and an in vitro DsbA-L knock-down evaluation using 16HBE14o-cells, a commonly evaluated human airway epithelial cell line. The DsbA-L rs1917760 polymorphism was associated with a reduction in the ratio of forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) and %FEV1 and with the elevation of the prevalence of FEV1/FVC < 70%. We also confirmed that the polymorphism was associated with a decreased respiratory function in relation to a decrease in the ratio of high-molecular-weight adiponectin/total adiponectin (as a marker of adiponectin multimerization) and an increase in the oxidized human serum albumin (as an oxidative stress marker). Furthermore, we clarified that DsbA-L knock-down induced oxidative stress and up-regulated the mucus production in human airway epithelial cells. These findings suggest that the DsbA-L gene may play a role in protecting the respiratory function of the elderly, possibly via increased systemic adiponectin functions secreted from adipocytes or through systemic and/or local pulmonary antioxidant properties

Supercapacitive Characteristics and Change in Oxidation State of Mn-Ni Oxide Solid Solution Electrodes

A divalent Mn-Ni oxide solid solution electrode was prepared by a hydrothermal method, and its electrochemical characteristics were investigated. As a result of optimizing preparation and heat treatment conditions and including nanocarbon as a conducting material, the potential window of electrode was successfully enlarged compared to that previously reported, reaching a specific capacitance of 363 F g−1. An aqueous electrolyte asymmetric supercapacitor consisting of electrodes of the Mn-Ni oxide including carbon (Mn-Ni-O/C) and activated carbon operated to an upper limit voltage of 2.5 V, leading to an energy density of 21.0 Wh kg−1 and an average power density of 21.8 kW kg−1. Moreover, the relationship between the oxidation number and the potential of the electrode was studied by X-ray photoelectron spectroscopy. For the first time, the oxidation number of Mn in the electrode was observed to change approximately in the range from divalent to tetravalent during the charge-discharge. This can be a very important guideline for increasing the capacitance and energy density of the Mn-based oxide electrodes