Partial cellular reprogramming stably restores the stemness of senescent epidermal stem cells.

OBJECTIVE: Adult stem cell senescence and exhaustion are important drivers of organismal age. Restored stem cell self-renewal has revealed novel therapeutic targets for decreasing the incidence of age-associated diseases (AADs) and prolonging the human health span. Transient ectopic expression of the reprogramming factors Oct3/4, Sox2, Klf4 and c-Myc (collectively known as OSKM) in somatic cells can induce partial cellular reprogramming and effectively ameliorate their age-associated hallmarks. However, how this form of rejuvenation is applied to senescent stem cells remains unknown. MATERIALS AND METHODS: The Integrin-α6highCD71high epidermal stem cells (ESCs) with low self-renewal ability were sorted by flow cytometry and then treated by the interrupted reprogramming induced by transient expression of OSKM. The ability of secondary clones' generation and self-proliferation in vitro, as well as stem cell marker p63, were detected to determine their self-renewal ability. Besides, gene and protein of epidermal cell markers were detected to determine whether their cell identities were retained. Finally, DNA methylation age (eAge) and DNA dehydroxymethylase/methyltransferase were analyzed to explore the alternation of their global DNA methylation pattern during this rejuvenation. RESULTS: The partial reprogramming restored the youthful self-renewal and proliferation in senescent ESCs, including larger secondary clone generation, higher expression of stem cell marker p63 and proliferation marker Ki67, and faster proliferation speed, in each case without abolishing epithelial cellular identity. Moreover, the rejuvenation of adult stem cells could be maintained for 2 weeks after reprogramming factor withdrawal, which was more stable than that of differentiated somatic cells. Additionally, we found that partial reprogramming counteracted the acceleration of eAge in senescent epidermal stem cells and DNA methyltransferase 1 (DNMT1) may play a crucial role in this process. CONCLUSIONS: Partial reprogramming has high therapeutic potential for reversing adult stem cell age, providing an advanced way to treat AADs.

Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations.

Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4]- was investigated using inelastic neutron scattering viewed from vibrational dynamics. The hydrogen release followed the softening of translational and [AlH4]- librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

Occurrence of Grapevine Leafroll-Associated Viruses in China.

To characterize the prevalence of viruses associated with grapevine leafroll disease in China, 249 grapevine (Vitis spp.) samples (86 popular cultivars and a rootstock) from 19 provinces and regions were collected and tested for Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, GLRaV-4, and GLRaV-4 strain 5 by SYBR Green real-time reverse-transcription polymerase chain reaction (RT-PCR), and RT-PCR and sequencing. GLRaV-3 was found in 100% of the samples while GLRaV-1, GLRaV-2, and GLRaV-4 were detected in 24.9% (62/249), 15.3% (38/249), and 0.80% (2/249) of the samples, respectively. Single infections with GLRaV-3 were found in 66.3% (165/249) of the samples, and the remaining samples were mixed infections of GLRaV-3 with one or two other GLRaVs, those with GLRaV-1 being the most common (18.5%, 46/249). The genetic variability of Chinese GLRaV-3 isolates was characterized based on the coat protein (CP) gene. In total, 153 full-length CP gene sequences (94 sequences newly generated) of Chinese GLRaV-3 isolates from different grapevine-growing regions showed 89.3 to 100.0% and 92.7 to 100.0% identity at the nucleotide and amino acid levels, respectively. The average nucleotide diversity for the population of Chinese GLRaV-3 isolates was estimated at 0.037 (standard error = 0.0032). GLRaV-3 isolates from China segregated into five distinct phylogenetic groups and two novel recombination events were found in the viral population. This is the first and most extensive report of the prevalent species of GLRaV in China, which also provides an assessment of genetic variability of GLRaV-3 Chinese isolates.

First Report of Grapevine leafroll-associated virus 7 in Two Native Grape Varieties in China.

Grapevine leafroll disease (GLD) is one of the most economically important diseases of cultivated grapevines (Vitis vinifera), causing decrease in yield, as well as decreasing the sugar levels and increasing the acidity of the berries (1). There are currently at least 10 serologically distinct viruses, referred to as grapevine leafroll-associated viruses (GLRaVs), from the family Closteroviridae that are associated with leafroll disease (4). China is one of the world's leading grape producers, and nearly 75% of the vineyards in China are located in Xinjiang Uygur Autonomous Region, and Hebei, Shandong, Gansu, Ningxia, and Yunnan provinces. Grapevine leafroll-associated virus 7 (GLRaV-7) isolates have been reported so far in Liaoning (GQ849392, GQ849393, and JF927943) and Henan (EF093187) provinces in China (3). The four Chinese isolates were isolated respectively from grape varieties, Cabernet Sauvignon (GQ849392, GQ849393), Centennial Seedless (JF927943), and Semillon (EF093187), and these grape varieties are introduced from abroad. Cow's Nipple and Dragon's Eye are old grape varieties native to China. Cow's nipple is extensively cultivated in Xinjiang Uygur Autonomous Region, while Dragon's Eye is widely planted in Heibei Province. To determine if GLRaV-7 was present in these two varieties, six samples (three per variety) were collected from six individual grapevines showing GLD-like symptoms in two vineyards in Xinjiang Uygur Autonomous Region and Hebei Province, respectively, in September 2011. Total RNA extracts obtained from phloem scrapings of samples using the RNeasy plant mini kit (QIAGEN) were tested by reverse transcription (RT)-PCR with primers F1 (5'-TATATCCCAACGGAGATGGC-3') and R1 (5'-ATGTTCCTCCACCAAAATCG-3') (2) specific to the heat shock protein 70 homologue (HSP-70 gene) of GLRaV-7. All samples produced a single band of the expected size of 502 bp. One GLRaV-7-specific amplicon per variety was cloned into pMD 18-T simple vector (TaKaRa). Plasmid DNA was purified using Column Plasmid DNAOUT (TIANDZ, Beijing, China) from three individual clones and sequenced from both directions. The sequence of the two isolates (GenBank Accession Nos. JX494722 and JX494723) shared 97.81% identity at the nucleotide level and 100% identity at the amino acid level. A pairwise comparison of HSP-70 sequences of the two isolates from this report with nine corresponding sequences of GLRaV-7 isolates (including four previously reported Chinese isolates) showed nucleotide sequence identities ranging from 91.24% (EF093187) to 98.80% (GQ849392). These samples were further analyzed by double antibody sandwich (DAS)-ELISA using antibody specific to GLRaV-7 (NEOGEN Europe, Ayr, Scotland) according to the manufacturer's instructions, and the results confirmed the presence of the virus in these samples that were positive by RT-PCR. To our knowledge, this is the first report of GLRaV-7 occurring in native grape varieties in China. These results could be helpful in developing sound diagnostic systems for implementing efficient disease management strategies. References: (1) B. Akbas et al. Hort. Sci. 36:97, 2009. (2) E. Engel et al. Plant Dis. 92:1252, 2008. (3) X. Fan et al. Acta Hortic. Sinica 39:949, 2012. (4) G. P. Martelli. Extended Abstr. 16th Meet. International Council for the Study of Virus and Virus-like Diseases of Grapevines (ICVG). 15-23, 2009.

Hypomethylation of the HTR1A promoter region and high expression of HTR1A in the peripheral blood lymphocytes of patients with systemic lupus erythematosus.

The occurrence of systemic lupus erythematosus (SLE) involves a gene-environment interaction and epigenetic regulations, such as DNA methylation, may play important role in the etiology of SLE. Some neurotransmitters, such as serotonin, can regulate T- and B-cell proliferation via the 5-HT1A receptor and are involved in the pathology of SLE. The abnormal methylation of DNA has been reported in SLE, but there has been no study concerning the serotonin system. This study was conducted to explore the DNA methylation status of the promoter region of HTR1A (PR-HTR1A) and the level of HTR1A mRNA in the peripheral blood lymphocytes (PBLC) of SLE patients and healthy controls (HC). In this study, the DNA methylation status of PR-HTR1A and the level of HTR1A mRNA were detected in the PBLC of SLE patients and HC. The results showed significant hypomethylation of PR-HTR1A in SLE patients compared with HC. The patients also showed a significantly higher HTR1A mRNA level than did the controls. Relatively higher percentage of anti-histone antibodies in methylated SLE patients was found compared with unmethylated patients. Our results support the hypothesis that the hypomethylation of PR-HTR1A and overexpression of HTR1A might contribute to SLE. These results also reveal that epigenetic regulation via the serotonin system may contribute to SLE, and reveal the link between the brain and the immune system.