Molecular and Functional Analysis of UDP-N-Acetylglucosamine Pyrophosphorylases from the Migratory Locust,Locusta migratoria

UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA’s derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species.     

Seasonal Distribution and Diversity of Ground Arthropods in Microhabitats Following a Shrub Plantation Age Sequence in Desertified Steppe

In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by seasonal variability, and they demonstrated distinctive communal fingerprints in different microhabitats for each plantation age stage.     

Identification and Candidate Gene Analysis of a Novel Phytophthora Resistance Gene Rps10 in a Chinese Soybean Cultivar

Resistance to Phytophthora sojae isolate PsMC1 was evaluated in 102 F_2∶3 families derived from a cross between the resistant soybean cultivar Wandou 15 and the susceptible cultivar Williams and genotyped using simple sequence repeat (SSR) markers. The segregation ratio of resistant, segregating, and susceptible phenotypes in the population suggested that the resistance in Wandou 15 was dominant and monogenic. Twenty-six polymorphic SSR markers were identified on soybean chromosome 17 (Molecular linkage group D2; MLG D2), which were linked to the resistance gene based on bulked segregation analysis (BSA). Markers Sattwd15-24/25 and Sattwd15-47 flanked the resistance gene at a distance of 0.5 cM and 0.8 cM, respectively. Two cosegregating markers, Sattwd15-28 and Sattwd15-32, were also screened in this region. This is the first Rps resistance gene mapped on chromosome 17, which is designated as Rps10. Eight putative genes were found in the mapped region between markers Sattwd15-24/25 and Sattwd15-47. Among them, two candidate genes encoding serine/threonine (Ser/Thr) protein kinases in Wandou 15 and Williams were identified and sequenced. And the differences in genomic sequence and the putative amino acid sequence, respectively, were identified within each candidate gene between Wandou 15 and Williams. This novel gene Rps10 and the linked markers should be useful in developing soybean cultivars with durable resistance to P. sojae.     

Analysis of Variations in the Glutamate Receptor,N-Methyl D-Aspartate 2A (GRIN2A) Gene Reveals Their Relative Importance as Genetic Susceptibility Factors for Heroin Addiction

The glutamate receptor, N-methyl D-aspartate 2A (GRIN2A) gene that encodes the 2A subunit of the N-methyl D-aspartate (NMDA) receptor was recently shown to be involved in the development of opiate addiction. Genetic polymorphisms in GRIN2A have a plausible role in modulating the risk of heroin addiction. An association of GRIN2A single-nucleotide polymorphisms (SNPs) with heroin addiction was found earlier in African Americans. To identify markers that contribute to the genetic susceptibility to heroin addiction, we examined the potential association between heroin addiction and forty polymorphisms of the GRIN2A gene using the MassARRAY system and GeneScan in this study. The frequency of the (GT)26 repeats (rs3219790) in the heroin addiction group was significantly higher than that in the control group (χ² = 5.360, P = 0.021). The allele frequencies of three polymorphisms (rs1102972, rs1650420, and rs3104703 in intron 3) were strongly associated with heroin addiction (P<0.001, 0.0002, and <0.001, after Bonferroni correction). Three additional SNPs from the same intron (rs1071502, rs6497730, and rs1070487) had nominally significant P values for association (P<0.05), but did not pass the threshold value. Haplotype analysis revealed that the G-C-T-C-C-T-A (block 6) and T-T (block 10) haplotypes of the GRIN2A gene displayed a protective effect (P = <0.001 and 0.003). These findings point to a role for GRIN2A polymorphisms in heroin addiction among the Han Chinese from Shaanxi province, and may be informative for future genetic or neurobiological studies on heroin addiction.     

Enhanced Nasal Mucosal Delivery and Immunogenicity of Anti-Caries DNA Vaccine through Incorporation of Anionic Liposomes in Chitosan/DNA Complexes

The design of optimized nanoparticles offers a promising strategy to enable DNA vaccines to cross various physiological barriers for eliciting a specific and protective mucosal immunity via intranasal administration. Here, we reported a new designed nanoparticle system through incorporating anionic liposomes (AL) into chitosan/DNA (CS/DNA) complexes. With enhanced cellular uptake, the constructed AL/CS/DNA nanoparticles can deliver the anti-caries DNA vaccine pGJA-P/VAX into nasal mucosa. TEM results showed the AL/CS/DNA had a spherical structure. High DNA loading ability and effective DNA protection against nuclease were proved by gel electrophoresis. The surface charge of the AL/CS/DNA depended strongly on pH environment, enabling the intracellular release of loaded DNA via a pH-mediated manner. In comparison to the traditional CS/DNA system, our new design rendered a higher transfection efficiency and longer residence time of the AL/CS/DNA at nasal mucosal surface. These outstanding features enable the AL/CS/DNA to induce a significantly (p<0.01) higher level of secretory IgA (SIgA) than the CS/DNA in animal study, and a longer-term mucosal immunity. On the other hand, the AL/CS/DNA exhibited minimal cytotoxicity. These results suggest that the developed nanoparticles offer a potential platform for DNA vaccine packaging and delivery for more efficient elicitation of mucosal immunity.     

Artemisinin Analogue SM934 Ameliorates Murine Experimental Autoimmune Encephalomyelitis through Enhancing the Expansion and Functions of Regulatory T Cell

Background

Artemisinin analogue SM934 was previously reported to possess immunosuppressive properties. The aim of this study was to determine the effects and the underlying mechanisms of SM934 in murine experimental autoimmune encephalomyelitis (EAE).

Methods

Female C57BL/6 mice immunized with MOG_35–55 were treated with or without SM934, then the clinical scores and other relevant parameters were assessed. Th1, Th17 and regulatory T (Treg) cell profiles were determined through ELISA, qRT-PCR, flow cytometry and BrdU incorporation assay. The effects of SM934 on Th1, Th17 and Treg cells differentiation were explored through intracellular staining and flow cytometry examination.

Results

In vivo, administration of SM934 significantly inhibited the development of EAE and suppressed the elevation of serum IL-17. Ex vivo, upon antigen-recall stimulation, IL-2, IFN-γ, IL-17 and IL-6 production were decreased, whereas IL-10 and TGF-β production were increased from the splenocytes isolated from SM934-treated mice. Consistently, both flow cytometry and qRT-PCR results showed that SM934 treatment significantly increased the Treg, while strongly suppressed the Th17 and Th1, responses in the peripheral. Furthermore, in the spinal lesion, SM934 treatment dramatically decreased the infiltration of CD4⁺ T cells, within which the Treg cells percentage was enlarged, whereas the Th17, but not Th1 percentage, was significantly decreased comparing with the vehicle-treated groups. Finally, both BrdU incorporation and in vitro Treg differentiation assays revealed that SM934 treatment could directly promote the expansion of Treg cells in vivo and in vitro.

Conclusion

Taken together, this study demonstrated that SM934 treatment could ameliorate the murine EAE disease, which might be mediated by inducing Treg differentiation and expansion.     

Krüppel-Like Factor 6 Rendered Rat Schwann Cell More Sensitive to Apoptosis via Upregulating FAS Expression

Krüppel-like factor 6 (KLF6) is a tumor suppressor gene and play a role in the regulation of cell proliferation and apoptosis. After the peripheral nerve injury (PNI), the microenvironment created by surrounding Schwann cells (SCs) is a critical determinant of its regenerative potential. In this study, we examined the effects of KLF6 on SCs responses during PNI. Both KLF6 mRNA and protein expression levels were upregulated in the injured sciatic nerve, and immunofluorescence results showed that many KLF6-positive cells simultaneously expressed the SC markers S-100 and p75NTR. The apoptosis inducers TNFα and cisplatin upregulated KLF6 expression in primary cultured SCs and the SC line RSC96. Although KLF6 overexpression exacerbated cisplatin- and TNFα-induced apoptosis, expression levels of the apoptosis regulators Bcl2 and Bax were not significantly affected in either KLF6-overexpressing or KLF6-depleted RSC96 cells. Realtime PCR arrays and qRT-PCR demonstrated that KLF6 overexpression upregulated four pro-apoptotic genes, FAS, TNF, TNFSF12, and PYCARD, and inhibited expression of the anti-apoptotic IL10 gene expression. Further analysis revealed that FAS protein expression was positively correlated with KLF6 expression in SCs. These data suggest that KLF6 upregulation may render SCs more vulnerable to apoptosis after injury via upregulating FAS expression.     

Select Dietary Phytochemicals Function as Inhibitors of COX-1 but Not COX-2

Recent clinical trials raised concerns regarding the cardiovascular toxicity of selective cyclooxygenase-2 (COX-2) inhibitors. Many active dietary factors are reported to suppress carcinogenesis by targeting COX-2. A major question was accordingly raised: why has the lifelong use of phytochemicals that likely inhibit COX-2 presumably not been associated with adverse cardiovascular side effects. To answer this question, we selected a library of dietary-derived phytochemicals and evaluated their potential cardiovascular toxicity in human umbilical vein endothelial cells. Our data indicated that the possibility of cardiovascular toxicity of these dietary phytochemicals was low. Further mechanistic studies revealed that the actions of these phytochemicals were similar to aspirin in that they mainly inhibited COX-1 rather than COX-2, especially at low doses.     

Family Income Affects Children’s Altruistic Behavior in the Dictator Game

This study aimed to examine how family income and social distance influence young rural Chinese children’s altruistic behavior in the dictator game (DG). A total of 469 four-year-old children from eight rural areas in China, including many children left behind by parents who had migrated to urban areas for work, played the DG. Stickers comprised the resource, while recipients in the game were assumed to be either their friends or strangers, with the social distance (i.e., strangers compared to friends) as a between-subjects variable. Children donated significantly more stickers to their friends than to strangers. Moreover, children from lower income families donated more stickers than children from higher income families. However, no gender and parental migrant status differences in children’s prosocial behaviors were evident in this sample. Findings of this study suggest that children’s altruistic behaviours to peers are influenced by family characteristics since preschool age. The probable influence of local socialization practices on development and the possible adaptive significance were discussed.