No abstract

No abstract

Aging is a complex issue, which results in a progressive decline process in cellular protection and physiological functions. Illustrating the causes of aging and pharmaceutical interference with the aging process has been a pivotal issue for thousands of years. Sargassum fusiforme (S. fusiforme), a kind of brown alga, is also named the "longevity vegetable" as it is not only a kind of food, but also used as an herb in traditional Chinese Medicine for maintaining health and treatment of thyroid disease, cardiovascular disease and so on. But how S. fusiforme promotes longevity is vastly equivocal. We got clues from S. fusiforme polysaccharides, which exhibited antioxidant activity, but the underlying mechanisms remained unclear. In this study, we evaluated the antioxidant effect and the possible mechanisms that S. fusiforme polysaccharides have against d-galactose-induced aging and chronic aging. We selected the SFPS as the candidate for antioxidant defense evaluation, which is a type of S. fusiforme polysaccharide with strong free radical scavenging activity and non-toxicity. It revealed that the antioxidant defense of the d-galactose-induced mice was markedly recovered when they were intragastrically administrated with the SFPS. However, oxidative damage may not be the only cause of aging. We further evaluated the function of the SFPS in the chronic aging mice. Intriguingly, we even found an obvious aging phenotype in the middle aged male ICR mice, which showed a significant decline in Nrf2-dependent cytoprotection. When 9-month old male ICR mice were treated with the SFPS for 2 months or even 11 months to their mean survival age, experimental measurements showed that the SFPS significantly promoted the antioxidant defense and mitochondrial integrity during aging. Furthermore, we suggest that the SFPS promotes Nrf2-dependent cytoprotection by upregulating the nuclear Nrf2 translocation, which may be mediated by p21 and JNK dependent pathways. These results suggest that the SFPS may decelerate the aging process by enhancing Nrf2-dependent cytoprotection, especially antioxidant defense.

Summary This paper investigates a divide-and-conquer algorithm for estimating the extreme value index when data are stored in multiple machines. The oracle property of such an algorithm based on extreme value methods is not guaranteed by the general theory of distributed inference. We propose a distributed Hill estimator and establish its asymptotic theories. We consider various cases where the number of observations involved in each machine can be either homogeneous or heterogeneous, and either fixed or varying according to the total sample size. In each case, we provide sufficient, sometimes also necessary, condition, under which the oracle property holds. Some key words: Extreme value index, Distributed inference, Distributed Hill estimator

HIV is the causative pathogen of AIDS, which has generated worldwide concern. Long noncoding RNAs (lncRNAs) are a rising star in virus-host cross-talk pathways; they are differentially expressed during many viral infections and are involved in multiple biological processes. Currently, lncRNA growth arrest-specific transcript 5 (GAS5) is known to be downregulated during HIV-1 infection. However, the functions and mechanisms of GAS5 in HIV-1 infection remain largely unknown. In this report, it was found for the first time that GAS5 could inhibit HIV-1 replication. Interestingly, using bioinformatics analyses (with Genomica and starBase.v2.0), GAS5 was found to potentially interact with miR-873. It was further verified that GAS5 could suppress miR-873. Moreover, miR-873 could promote HIV-1 replication. Together, these results not only suggest that GAS5 may inhibit HIV-1 replication through interaction with miR-873 but the results may also provide novel biomarkers for antiviral drugs or potential targets for future therapeutics for HIV/AIDS.