Correlation between heat shock protein 32 and chronic heat-induced liver injury in developing mice

Heat stress is one of a wide variety of factors causing liver injury, a small heat shock protein (HSP), HSP32, is induced by heat stress in the liver. But the biological function of HSP32 in this injury is unclear. To investigate the underlying role of HSP32, RT-PCR, immunocytochemical staining and ELISA were applied to confirm the expression of HSP32. And the underlying mechanism in the pathogenesis of hepatic dysfunction following hyperthermic challenge and the possible involvement of oxidative stress to induce oxidative deterioration of liver functions in developing mice were investigated in this study. Caspase-3mRNA expression and caspase-3 activity of heated liver were also analysed. The results showed that liver injury caused by chronic heat stress(39 °C, 1.5 h/day for 6 weeks) was reversible, caspase-3mRNA expression and caspase-3 activity of heat treated mice were increased after the first three weeks of heat exposure (P<0.05) and high expression levels of HSP32 were observed throughout the duration of experiment (P<0.01). A strong correlation exists between heat-induced liver injury and the induction of HSP32, which suggested that the reversibility of liver injury is involved in the induction of HSP32 in the hepatic cells under continuing heat stress.     

Mast cells expressing interleukin 17 in the muscularis propria predict a favorable prognosis in esophageal squamous cell carcinoma

The proinflammatory cytokine interleukin 17 (IL-17) is considered to play a crucial role in diverse human tumors; however, its role in disease progression remains controversial. This study investigated the cellular source and distribution of IL-17 in esophageal squamous cell carcinoma (ESCC) in situ and determined its prognostic value. Immunohistochemistry, immunofluorescence and immunoelectron microscopy were used to identify IL-17-expressing cells in ESCC tissues, paying particular attention to their anatomic localization. Kaplan–Meier analysis and Cox proportional hazards regression models were applied to estimate overall survival in 215 ESCC patients with long-term follow-up (>10 years). The results showed that mast cells, but not T cells or macrophages, were the predominant cell type expressing IL-17 in ESCC tissues. Unexpectedly, these IL-17⁺ cells were highly enriched in the muscularis propria rather than the corresponding tumor nest (p < 0.0001). The density of IL-17⁺ cells in muscularis propria was inversely associated with tumor invasion (p = 0.016) and served as an independent predictor of favorable survival (p = 0.007). Moreover, the levels of IL-17⁺ cells in muscularis propria were positively associated with the density of effector CD8⁺ T cells and activated macrophages in the same area (both p < 0.0001). This finding suggested that mast cells may play a significant role in tumor immunity by releasing IL-17 at a previously unappreciated location, the muscularis propria, in ESCC tissues, which could serve as a potential prognostic marker and a novel therapeutic target for ESCC.     

Relationship between chemokine (C–X–C motif) ligand 12 gene variant (rs1746048) and coronary heart disease: Case–control study and meta-analysis

The goal of our study is to evaluate the contribution of CXCL12 rs1746048 (hg19, chr10:44775574) to the risk of CHD in Han Chinese, and to summarize its role in CHD through meta-analysis of existing studies among various ethnic groups. Significant association is observed between rs1746048-C and an increased risk of CHD in Han Chinese (χ² = 5.41, df = 1, P = 0.02). Post hoc analysis reveals an even stronger association of rs1746048 with the risk of CHD for subjects aged 65 years or older (genotype: χ² = 8.39, df = 2, P = 0.015; allele: χ2 = 9.13, df = 1, P = 0.003, odd ratio (OR) = 1.91, 95% confidential interval (CI) = 1.25–2.91). A break down analysis by gender shows that rs1746048 is likely a CHD risk factor under the recessive model in males (CC + CT versus TT: P = 0.05, χ² = 3.59, df = 1, OR = 1.72, 95% CI = 1.00–3.04). In addition, a meta-analysis of ten studies among over 107,000 individuals confirms that rs1746048 is a risk factor of CHD (P < 0.0001, OR = 1.12, 95% CI = 1.09–1.15) and this agrees with the findings of our case–control study in Han Chinese.     

Structure of a bacterial type IV secretion core complex at subnanometre resolution

Type IV secretion (T4S) systems are able to transport DNAs and/or proteins through the membranes of bacteria. They form large multiprotein complexes consisting of 12 proteins termed VirB1‐11 and VirD4. VirB7, 9 and 10 assemble into a 1.07 MegaDalton membrane‐spanning core complex (CC), around which all other components assemble. This complex is made of two parts, the O‐layer inserted in the outer membrane and the I‐layer inserted in the inner membrane. While the structure of the O‐layer has been solved by X‐ray crystallography, there is no detailed structural information on the I‐layer. Using high‐resolution cryo‐electron microscopy and molecular modelling combined with biochemical approaches, we determined the I‐layer structure and located its various components in the electron density. Our results provide new structural insights on the CC, from which the essential features of T4S system mechanisms can be derived.     

Mirror‐symmetric microtubule assembly and cell interactions drive lumen formation in the zebrafish neural rod

By analysing the cellular and subcellular events that occur in the centre of the developing zebrafish neural rod, we have uncovered a novel mechanism of cell polarisation during lumen formation. Cells from each side of the neural rod interdigitate across the tissue midline. This is necessary for localisation of apical junctional proteins to the region where cells intersect the tissue midline. Cells assemble a mirror‐symmetric microtubule cytoskeleton around the tissue midline, which is necessary for the trafficking of proteins required for normal lumen formation, such as partitioning defective 3 and Rab11a to this point. This occurs in advance and is independent of the midline cell division that has been shown to have a powerful role in lumen organisation. To our knowledge, this is the first example of the initiation of apical polarisation part way along the length of a cell, rather than at a cell extremity. Although the midline division is not necessary for apical polarisation, it confers a morphogenetic advantage by efficiently eliminating cellular processes that would otherwise bridge the developing lumen.     

Microarray analysis of gene expression profile in resistant and susceptible Bombyx mori strains reveals resistance-related genes to nucleopolyhedrovirus

To investigate the molecular mechanism of silkworm resistance to BmNPV infection, we constructed a near-isogenic line (BC8) with BmNPV resistance using highly resistant (NB) and highly susceptible parental strains (306). We investigated variations in the gene expression in the midguts of BmNPV-infected BC8 and 306 at 12 h pi using the microarray. 92 differentially expressed genes were identified. Real-time qPCR analysis confirmed that 10 genes were significantly up-regulated or down-regulated in the midguts of BC8 and NB compared to 306. To our knowledge, we first defined the role of the amino acid transporter and 26S proteasome in insect antiviral. However, serine protease was not completely consistent with data of reported previously in insect antiviral. The role of the 5 genes (Bm123, Bm122, COP β′, aquaporin, glycoside hydrolases) was also demonstrated in insect antiviral. Our results provided new insights into the molecular mechanism of the Bombyx mori immune response against BmNPV infection.     

Bifunctional oligo(ethylene glycol) decorated surfaces which permit covalent protein immobilization and resist protein adsorption

In this article, surface coatings derived from homo-bifunctional tri(ethylene glycol) (EG₃) and hexa(ethylene glycol) (EG₆) molecules which have two terminal aldehyde groups are reported. These homo-bifunctional molecules can be used to functionalize amine-terminated surfaces through crosslinking one aldehyde group to surface amine groups, while leaving the other aldehyde group available for covalent immobilization of proteins. Best of all, after reducing remaining aldehyde groups on the surface with a reducing agent, sodium borohydride, the surface becomes oligo(ethylene glycol) (OEG)-terminated. The OEG-terminated surface can resist nonspecific protein adsorption, a feature that is often required for many biosensors and biomedical devices. Although some mixed self-assembled monolayers formed from two different organothiols also permit covalent protein immobilization and resist nonspecific protein adsorption, the procedure reported herein requires only one type of homo-bifunctional molecule and can be applied to both silicon and gold surfaces.     

Intermediate herbivory intensity of an aboveground pest promotes soil labile resources and microbial biomass via modifying rice growth

Background and Aims

The importance of aboveground herbivores for modifying belowground ecosystems has prompted numerous studies; however, studies can be biased by context dependent conditions which lead to extremely inconsistent results. So far, the impacts of herbivory intensity by important rice pests on rice paddy soil ecosystems are lacking. The aim of this study was to test the hypothesis that intermediate herbivory intensity of the brown planthopper (Nilaparvata lugens Stål) could promote soil labile resources and microbial biomass, while high intensity would show a reverse pattern, by mediating rice plant growth. This study will also help the development of integrative pest management.

Methods

Four hopper infestation density treatments (0, 4, 8 and 12 nymphs per rice plant) and two infestation duration treatments (9 and 15 days after N. lugens infestation, DAI 9 and DAI 15) were established in a glasshouse experiment. Soil and plant were sampled destructively from four replicates and analysed for soil labile resources availability, soil microbial biomass and plant performance, respectively.

Results

The infestation density significantly affected both shoot and root mass of rice (P?<?0.05), soil dissolved organic carbon (DOC) and nitrogen (DON), and microbial biomass carbon (MBC) and nitrogen (MBN), and the effects were further enhanced by prolonged infestation duration. Compared to the control (CK) without N. lugens, plant dry mass, DOC, DON, MBC and MBN increased under low (LD) and moderate hopper densities (MD) but decreased under high density (HD) on DAI 9. Moreover, the LD treatment exerted the most promotional effects on DAI 15. Rice root to shoot ratio generally increased in treatments subjected to herbivory. The labile resources and microbial biomass showed close relationships with both shoot and root mass across treatments, in particular with root mass on DAI 15. Such a trend indicated that the shift of photosynthate allocation to belowground contributed to changes of soil resource availability and microbial biomass.

Conclusions

Intermediate herbivory intensity showed positive effects on rice seedling performance and, further, promoted soil labile resource availability and microbial biomass. The importance of extrapolating temporal and spatial scale, i.e. from the short-term greenhouse experiment to an entire rice growing season in the field, was highlighted.     

Isolation of Paenibacillus sp. and Assessment of its Potential for Enhancing Mineral Weathering

One mineral-solubilizing bacterial strain designated KT was isolated from a soil in Henan Province, China. The full-length 16S rRNA gene sequence showed 95.2 to 96.7% similarity to the bacteria of the genus Paenibacillus, indicating that the strain KT belonged to the genus Paenibacillus. The potential of this strain to release potassium from silicate minerals was investigated using a potassium-bearing rock as the sole source of potassium to support its growth. After inoculation for 7 days, the concentrations of water-soluble Al, Ca and Fe released from the potassium-bearing rock in active bacterial culture were higher than those from the control with autoclaved inoculum, but the concentration of water-soluble K in active bacterial culture was similar to that in the control. The concentrations of HNO₃-extractable Al, Ca, Fe and K from the bacterial culture were also higher than those in the control. These results showed strain KT was able to release potassium from potassium-bearing rock. These results have important implications for extraction of potassium from rocks to support plant growth.     

Microbial Diversity and Community Structure on Corroding Concretes

The objective of this study was to analyze bacterial diversity in two different concrete samples to understand the dominant types of bacteria that may contribute to concrete corrosion. Two concrete samples, HN-1 from the sunny side and HN-2 from dark and damp side, were collected from Zijin Mountain in Nanjing and genomic DNA was extracted. The partial bacterial 16S rRNA gene fragment was PCR amplified and two clone libraries were constructed. Amplified ribosomal DNA restriction analysis (ARDRA) was performed by digestion of the 16S rRNA gene and each unique restriction fragment polymorphism pattern was designated as an operational taxonomic unit (OTU). Phylogenetic trees of bacterial 16S rDNA nucleotide sequences were constructed. Sample HN-1 and HN-2 contained 21 OTUs and 26 OTUs, respectively. Proteobacteria and Planctomycetes were the predominant bacteria in both samples, and they are distributed among Herbaspirillum, Archangium, Phyllobacteriaceae and Planctomycetaceae. Cyanobacteria and Rubrobacter sp. are dominant in HN-1; while Acidobacteriaceae, Adhaeribacter sp. and Nitrospira sp. are predominant in HN-2. This distribution pattern was consistent with local environmental conditions of these two samples. The inferred physiological characteristics of these bacteria, based on relatedness of the DNA clone sequences to cultivated species, revealed different mechanisms of concrete corrosion depending on the local environmental conditions.