KITLG is a novel target of miR‐34c that is associated with the inhibition of growth and invasion in colorectal cancer cells

MiR‐34c is considered a potent tumour suppressor because of its negative regulation of multiple target mRNAs that are critically associated with tumorigenesis and metastasis. In the present study, we demonstrated a novel target of miR‐34c, KITLG, which has been implicated in colorectal cancer (CRC). First, we found a significant negative relationship between miR‐34c and KITLG mRNA expression levels in CRC cell lines, including HT‐29, HCT‐116, SW480 and SW620 CRC cell lines. In silico analysis predicted putative binding sites for miR‐34c in the 3′ untranslated region (3′UTR) of KITLG mRNA. A dual‐luciferase reporter assay further confirmed that KITLG is a direct target of miR‐34c. Then, the cell lines were infected with lentiviruses expressing miR‐34c or a miR‐34c specific inhibitor. Restoration of miR‐34c dramatically reduced the expression of KITLG mRNA and protein, while silencing of endogenous miR‐34c increased the expression of KITLG protein. The miR‐34c‐mediated down‐regulation of KITLG was associated with the suppression on proliferation, cellular transformation, migration and invasion of CRC cells, as well as the promotion on apoptosis. Knockdown of KITLG by its specific siRNA confirmed a critical role of KITLG down‐regulation for the tumour‐suppressive effects of miR‐34c in CRC cells. In conclusion, our results demonstrated that miR‐34c might interfere with KITLG‐related CRC and could be a novel molecular target for CRC patients.     

Sulfur‐Impregnated,Sandwich‐Type,Hybrid Carbon Nanosheets with Hierarchical Porous Structure for High‐Performance Lithium‐Sulfur Batteries

Sandwich‐type hybrid carbon nanosheets (SCNMM) consisting of graphene and micro/mesoporous carbon layer are fabricated via a double template method using graphene oxide as the shape‐directing agent and SiO₂ nanoparticles as the mesoporous guide. The polypyrrole synthesized in situ on the graphene oxide sheets is used as a carbon precursor. The micro/mesoporous strcutures of the SCNMM are created by a carbonization process followed by HF solution etching and KOH treatment. Sulfur is impregnated into the hybrid carbon nanosheets to generate S@SCNMM composites for the cathode materials in Li‐S secondary batteries. The microstructures and electrochemical performance of the as‐prepared samples are investigated in detail. The hybrid carbon nanosheets, which have a thickness of about 10–25 nm, high surface area of 1588 m² g^?1, and broad pore size distribution of 0.8–6.0 nm, are highly interconnected to form a 3D hierarchical structure. The S@SCNMM sample with the sulfur content of 74 wt% exhibits excellent electrochemical performance, including large reversible capacity, good cycling stability and coulombic efficiency, and good rate capability, which is believed to be due to the structure of hybrid carbon materials with hierarchical porous structure, which have large specific surface area and pore volume.     

Comparative proteomic analysis of methyl jasmonate‐induced defense responses in different rice cultivars

Jasmonate is an important endogenous chemical signal that plays a role in modulation of plant defense responses. To understand its mechanisms in regulation of rice resistance against the fungal pathogen Magnaporthe oryzae, comparative phenotype and proteomic analyses were undertaken using two near‐isogenic cultivars with different levels of disease resistance. Methyl‐jasmonate (MeJA) treatment significantly enhanced the resistance against M. oryzae in both cultivars but the treated resistant cultivar maintained a higher level of resistance than the same treated susceptible cultivars. Proteomic analysis revealed 26 and 16 MeJA‐modulated proteins in resistant and susceptible cultivars, respectively, and both cultivars shared a common set of 13 proteins. Cumulatively, a total of 29 unique MeJA‐influenced proteins were identified with many of them known to be associated with plant defense response and ROS accumulation. Consistent with the findings of proteomic analysis, MeJA treatment increased ROS accumulation in both cultivars with the resistant cultivar showing higher levels of ROS production and cell membrane damage than the susceptible cultivar. Taken together, our data add a new insight into the mechanisms of overall MeJA‐induced rice defense response and provide a molecular basis of using MeJA to enhance fungal disease resistance in resistant and susceptible rice cultivars.     

Cofactor and CO2 donor regulation involved in reductive routes for polymalic acid production by Aureobasidium pullulans CCTCC M2012223

Polymalic acid (PMA) is a water-soluble polyester with many attractive properties for biomedical application. Its monomer l-malic acid is widely used in the food industry and also a potential C4 platform chemical. Cofactor and CO₂ donor involved in the reductive routes were investigated for PMA production by Aureobasidium pullulans. Biotin as the key cofactor of pyruvate carboxylase was favor for the PMA biosynthesis. Na₂CO₃ as CO₂ donor can obviously improved PMA titer when compared with no CO₂ supplier NaOH, and also exhibit more advantages than the other donor CaCO₃ because of its water-soluble characteristic. A combinational process with addition of biotin 70 mg/L and Na₂CO₃ as the CO₂ donor was scaled-up in 50 L fermentor, achieving the high product 34.3 g/L of PMA and productivity of 0.41 g/L h. This process provides an efficient and economical way for PMA and malic acid production, and is promising for industrial application.     

MTHFR基因多态性与中国北方人群脑膜瘤发病的相关性分析

目的:探讨亚甲基四氢叶酸还原酶(MTHFR)基因多态性与中国北方人群脑膜瘤发病的相关性。方法:选择2012年1月-2013年12月在黑龙江省哈尔滨医科大学附属第二医院的第一、三病房接受手术治疗的脑膜瘤患者317例(实验组)及320例非脑膜瘤患者(对照组)为研究对象,利用聚合酶链反应限制性多态性片段长度(PCR-RFLP)检测和比较两组MTHFR两个单核苷酸多态性位点(C677T、A1298C)各种基因型(CC、CT、TT)的分布情况及等位基因的频率。结果:两组MTHFR的C677T中CC基因型的频率和TT基因型的频率比较有显著性差异(CC:OR=2.012,95%CI=1.460-2.772;TT:OR=0.399,95%CI=0.254-0.628,P0.05),实验组MTHFR的(0.450)C677T中的T等位基因频率明显高于对照组(0.320)(OR=0.529,95%CI=0.420-0.666,P0.05)。两组A1298C的等位基因分布比较没有统计学差别(P0.05)。结论:MTHFR基因的C677T中TT等位基因提示潜在的易患脑膜瘤的风险,而CC等位基因会降低中国北方人群患脑膜瘤的风险。     

A 2D graphical representation of the sequences of DNA based on triplets and its application

In this paper, we first present a new concept of ‘weight’ for 64 triplets and define a different weight for each kind of triplet. Then, we give a novel 2D graphical representation for DNA sequences, which can transform a DNA sequence into a plot set to facilitate quantitative comparisons of DNA sequences. Thereafter, associating with a newly designed measure of similarity, we introduce a novel approach to make similarities/dissimilarities analysis of DNA sequences. Finally, the applications in similarities/dissimilarities analysis of the complete coding sequences of β-globin genes of 11 species illustrate the utilities of our newly proposed method.     

The effect of aging on the frequency,phenotype and cytokine production of human blood CD4 + CXCR5 + T follicular helper cells: comparison of aged and young subjects

Background

T cell-dependent B-cell responses decline with age, indicating declined cognate helper activity of aged CD4?+?T cells for B cells. However, the mechanisms remain unclear. T follicular helper (Tfh) cells, a novel T helper subset, play an essential role in helping B cells differentiation into long-lived plasma cells in germinal center (GC) or short-lived plasma cells. In the present study, we proposed that there might existe changes of proportion, phenotype or cytokine production of blood Tfh cells in healthy elderly individuals compared with healthy young individuals.

Results

The results showed that frequencies of aged blood CXCR5?+?CD4?+?Tfh cells increased compared with young subjects. Both aged and young blood CXCR5?+?CD4?+?Tfh cells constitutively expressed CD45RO, CCR7 and CD28, and few of these cells expressed CD69 or HLA-DR, which indicated that they were resting memory cells. There was no significant difference of IL-21 frequency production by aged blood CXCR5?+?CD4?+?Tfh determined by FACS compared with young individuals, however, aged PBMCs produced significantly higher levels of IL-21 evaluated by ELISA. Furthermore, there were no significant differences of percentages of IFN-γ, IL-4, IL-17 or IL-22 production by aged Tfh cells compared with their counterparts of young individuals respectively. However, frequencies of IL-17+ cells within aged CD4?+?CXCR5-T cells were markedly lower than in the young individuals. Furthermore we observed different frequencies of IFN-γ, IL-17, IL-4 or IL-22 production by Tfh or by CD4?+?CXCR5- cells in aged and young subjects respectively.

Conclusions

Our data demonstrated that the frequencies of blood memory CXCR5?+?CD4?+?Tfh cells increased in the elderly population. There were similar frequencies of Th characterized cytokine production such as IL-21, IFN-γ, IL-4, IL-17 or IL-22 in aged and young Tfh cells. However, aged PBMCs produced a significantly higher amount of IL-21 compare to young subjects.