Umbilical Cord Mesenchymal-Stem-Cell-Derived Exosomes Exhibit Anti-Oxidant and Antiviral Effects as Cell-Free Therapies.

The oxidative stress induced by the accumulation of reactive oxygen species (ROS) can lead to cell aging and death. Equally, the skeletal muscle usually hosts enteroviral persistent infection in inflammatory muscle diseases. As excellent bioactive products, the exosomes derived from umbilical cord mesenchymal stem cells (ucMSCs) have been proven to be safe and have low immunogenicity with a potential cell-free therapeutic function. Here, exosomes derived from ucMSCs (ucMSC-EXO) were extracted and characterized. In a model of oxidative damage to skin fibroblasts (HSFs) under exposure to H2O2, ucMSC-EXO had an observable repairing effect for the HSFs suffering from oxidative damage. Furthermore, ucMSC-EXO inhibited mitogen-activated protein kinases (MAPK), c-Jun N-terminal kinase (JNK), and nuclear factor kappa-B (NF-κB) signaling pathways, thereby promoting p21 protein expression while decreasing lamin B1 protein expression, and finally alleviated oxidative stress-induced cell damage and aging. In a model of rhabdomyosarcoma (RD) cells being infected by enterovirus 71 (EV71) and coxsackievirus B3 (CVB3), the ucMSC-EXO enhanced the expression of interferon-stimulated gene 15 (ISG15) and ISG56 to inhibit enteroviral replication, whereafter reducing the virus-induced proinflammatory factor production. This study provides a promising therapeutic strategy for ucMSC-EXO in anti-oxidative stress and antiviral effects, which provides insight into extending the function of ucMSC-EXO in cell-free therapy.

Innate Immunity, Inflammation, and Intervention in HBV Infection.

Hepatitis B virus (HBV) infection is still one of the most dangerous viral illnesses. HBV infects around 257 million individuals worldwide. Hepatitis B in many individuals ultimately develops hepatocellular carcinoma (HCC), which is the sixth most common cancer and the third leading cause of cancer-related deaths worldwide. The innate immunity acts as the first line of defense against HBV infection through activating antiviral genes. Along with the immune responses, pro-inflammatory cytokines are triggered to enhance the antiviral responses, but this may result in acute or chronic liver inflammation, especially when the clearance of virus is unsuccessful. To a degree, the host innate immune and inflammatory responses dominate the HBV infection and liver pathogenesis. Thus, it is crucial to figure out the signaling pathways involved in the activation of antiviral factors and inflammatory cytokines. Here, we review the interplay between HBV and the signal pathways that mediates innate immune responses and inflammation. In addition, we summarize current therapeutic strategies for HBV infection via modulating innate immunity or inflammation. Characterizing the mechanisms that underlie these HBV-host interplays might provide new approaches for the cure of chronic HBV infection.

Development and characterization of 18 EST-SSR markers in Sonneratia caseolaris.

PREMISE OF THE STUDY: Sonneratia caseolaris, a typical mangrove species, is widely distributed in the Indo-West Pacific region. EST-SSR markers were developed for this species to examine its genetic diversity. METHODS AND RESULTS: A total of 18 EST-SSR primer pairs were designed based on the transcriptome sequences of S. caseolaris. Thirteen primer pairs showed polymorphism with one to three alleles per locus when assessed in two populations from China and Australia. The observed heterozygosity and expected heterozygosity ranged from 0 to 0.5000, and 0 to 0.5217 in the Hainan population, and from 0 to 0.2500, and 0 to 0.4891 in the Queensland population, respectively. Thirteen of the 18 primer sets identified in S. caseolaris can be successfully applied to its congener S. alba, and a much lower level of polymorphisms was observed in this widespread species. CONCLUSIONS: These polymorphic EST-SSR markers for S. caseolaris are likely to be useful for future genetic diversity studies.

Comparative genomics of two ecologically differential populations of Hibiscus tiliaceus under salt stress.

Hibiscus tiliaceus L. is a mangrove associate that occupies the divergent environments of intertidal wetland (L population) and inland (T population). Thus, it is an ideal plant for the study of ecological adaptation and salt tolerance. In this study we compared responses of the two populations to salinity combining a global transcriptional analysis and physiological analysis. Microarray transcript profiling analysis showed both shared and divergent responses to salinity stress in the two populations. A total of 575 unigenes were identified as being salt-responsive in the two populations. Shared responses were exemplified by the regulated genes functioning in confining ribosomal functions, photosynthesis and cellular metabolism. A set of genes functioning in cellular transporting and cell detoxification and a crucial transcription factor AP2 domain-containing protein involved in environmental responsiveness, were differently expressed in the two populations. Physiological analysis showed that the L population was less susceptible to salt stress in photosynthesis and had a stronger capability of K+:Na+ regulation than the T population. Both microarray and physiological data showed the L population possess higher fitness under high salinity, probably due to it its long-term adaptation to their native environment.

Identification and characterization of single nucleotide polymorphisms in 12 chicken growth-correlated genes by denaturing high performance liquid chromatography.

The genes that are part of the somatotropic axis play a crucial role in the regulation of growth and development of chickens. The identification of genetic polymorphisms in these genes will enable the scientist to evaluate the biological relevance of such polymorphisms and to gain a better understanding of quantitative traits like growth. In the present study, 75 pairs of primers were designed and four chicken breeds, significantly differing in growth and reproduction characteristics, were used to identify single nucleotide polymorphisms (SNP) using the denaturing high performance liquid chromatography (DHPLC) technology. A total of 283 SNP were discovered in 31 897 base pairs (bp) from 12 genes of the growth hormone (GH), growth hormone receptor (GHR), ghrelin, growth hormone secretagogue receptor (GHSR), insulin-like growth factor I and II (IGF-I and -II), insulin-like growth factor binding protein 2 (IGFBP-2), insulin, leptin receptor (LEPR), pituitary-specific transcription factor-1 (PIT-1), somatostatin (SS), thyroid-stimulating hormone beta subunit (TSH-beta). The observed average distances in bp between the SNP in the 5'UTR, coding regions (non- and synonymous), introns and 3'UTR were 172, 151 (473 and 222), 89 and 141 respectively. Fifteen non-synonymous SNP altered the translated precursors or mature proteins of GH, GHR, ghrelin, IGFBP-2, PIT-1 and SS. Fifteen indels of no less than 2 bps and 2 poly (A) polymorphisms were also observed in 9 genes. Fifty-nine PCR-RFLP markers were found in 11 genes. The SNP discovered in this study provided suitable markers for association studies of candidate genes for growth related traits in chickens.

Achieving differentiation of single-base mutations through hairpin oligonucleotide and electric potential control.

A novel assay for surface DNA hybridization, which is free of sample and probe labeling, convenient and of low cost, sensitive and capable of differentiation of single-base mutations, is reported. Hairpin oligonucleotides are carefully designed as probes and are covalently attached to Si chips. Segments of the human p53 gene are chosen to demonstrate the major features of the novel technique. Impedance measurement is used to detect the hybridization. To further optimize the performance, electric potential is applied on the chip. The apparently different responses of the chip to the complementary strand and the single-base mutant are shown under electric potential control. The criteria on the design of the hairpin oligonucleotides are discussed.