Developmental motoneuron cell death and neurotrophic factors

During the development of higher vertebrates, motoneurons are generated in excess. In the lumbar spinal cord of the developing rat, about 6000 motoneurons are present at embryonic day 14. These neurons grow out axons which make contact with their target tissue, the skeletal muscle, and about 50% of the motoneurons are lost during a critical period from embryonic day 14 until postnatal day 3. This process, which is called physiological motoneuron cell death, has been the focus of research aiming to identify neurotrophic factors which regulate motoneuron survival during this developmental period. Motoneuron cell death can also be observed in vitro when the motoneurons are isolated from the embryonic avian or rodent spinal cord. These isolated motoneurons and other types of primary neurons have been a useful tool for studying basic mechanisms underlying neuronal degeneration during development and under pathophysiological conditions in neurodegenerative disorders. Accumulating evidence from such studies suggests that some specific requirements of motoneurons for survival and proper function may change during development. The focus of this review is a synopsis of recent data on such specific mechanisms.     

Cloning and expression analysis of a muscarinic cholinergic receptor from the brain of ant,Polyrhachis vicina

Muscarinic acetylcholine receptors (mAchRs) are the predominant cholinergic receptors in the central and peripheral nervous systems of animals. They also have been found in various insect nervous systems. In this article, a full‐length cDNA of a pupative mAchR (PmAchR) was obtained from the brains of ant Polyrhachis vicina by homology cloning in combination with rapid amplification of cDNA ends. PmAchR encodes a 599‐amino acid protein that exhibits a high degree of homology with other mAchRs. Real‐time quantitative RT‐PCR analysis showed that PmAchR is differentially expressed in the brains of workers, males, and females. By in situ hybridization, it is revealed that PmAchR is widely expressed in different soma clusters of the brain, including the mushroom bodies, the antennal lobes, as well as the optic lobes (OL), and the most intensely staining is found in Kenyon cells. Nonetheless, there are more positive nerve fibers in the OL of males' brains than in females' and workers' brains. © 2011 Wiley Periodicals, Inc.     

A regulatory effect of IL-21 on T follicular helper-like cell and B cell in rheumatoid arthritis

Introduction

Interleukin (IL)-21 is a member of type I cytokine family. Recent studies indicate that IL-21 can promote T follicular helper (Tfh) cell differentiation and survival, a specialized T cell subset which provides help for B cell. It can also regulate the activation, proliferation and differentiation of human B cell and immunoglobulin (Ig) production as well as isotype switching of plasma cell. Rheumatoid arthritis (RA) is characterized by auto-antibodies overproduction such as rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody, suggesting a pivotal role of Tfh cell and B cell in the pathogenesis of RA. This study aimed to investigate whether IL-21 had a regulatory effect on Tfh cell and B cell in RA.

Methods

Serum IL-21 concentrations were measured by ELISA. The correlations between serum IL-21 levels and clinical features of RA patients were analyzed by Spearman''s rank test. The percentages of Tfh-like cells, IL-21 receptor (R) expression on Tfh-like cells and B cells in peripheral blood (PB) were analyzed by flow cytometry. Peripheral blood mononuclear cells (PBMC) were stimulated by rIL-21 (100 ng/ml) in the presence or absence of anti-CD40 and/or anti-IgM, and changes of IL-21R, activation-associated surface markers (CD25, CD69 and CD40), the proliferation, apoptosis and differentiation of B cells were analyzed by flow cytometry. Production of IgG and IgM in the culture supernatants was determined by ELISA.

Results

The results showed that the serum IL-21 levels in RA patients were significantly higher than that of healthy controls (HC). IL-21 concentrations were positively correlated with 28-joint count disease activity score (DAS28) and anti-CCP antibody in RA patients with high IL-21 levels. Furthermore, the frequencies of peripheral CXCR5⁺PD-1⁺CD4⁺ Tfh-like cells markedly increased in RA patients and the percentages of Tfh-like cells were positively correlated with DAS28 and anti-CCP antibody levels. Moreover, elevated IL-21 levels were also correlated with the frequencies of Tfh-like cells. IL-21R expression on both Tfh-like cells and B cells were significantly enhanced in RA patients. In cultures vitro, exogenous IL-21 upregulated IL-21R expression and activation-associated surface markers on B cells and promoted more B cell proliferation in RA than in HC. This IL-21-mediated effect could be reversed by IL-21R-specific neutralizing antibody. Importantly, IL-21 promoted more differentiation of B cell into plasmablast and higher levels of IgG and IgM production in RA than in HC.

Conclusions

Increased serum IL-21 levels in RA patients correlate with DAS28, anti-CCP antibody and frequencies of Tfh-like cells. IL-21 supports B cell activation, proliferation and antibody secretion via IL-21R pathway. Thus, IL-21 may be involved in the pathogenesis of RA and antagonizing IL-21 could be a novel strategy for the therapy of RA.     

Development of microsatellite primers of the largest seagrass, Enhalus acoroides (Hydrocharitaceae)

? Premise of the study: Microsatellite primers were developed for the seagrass Enhalus acoroides to investigate genetic variation and identify clonal structure. ? Methods and Results: Four polymorphic loci and 32 monomorphic loci were developed in E. acoroides. Two to four alleles per locus were observed at the polymorphic loci across 60 individuals of two E. acoroides populations. The observed and expected heterozygosities within populations ranged from 0.100 to 0.5667 and from 0.0977 to 0.5079, respectively. ? Conclusions: Our study revealed very low polymorphism in E. acoroides, even at the polymorphic loci. Nevertheless, these primers are a useful tool to study genetic variation, clonal structure, and mating system.     

Bioremediation of β-cypermethrin and 3-phenoxybenzaldehyde contaminated soils using Streptomyces aureus HP-S-01

Using laboratory and field experiments, the ability of Streptomyces aureus HP-S-01 to eliminate β-cypermethrin (β-CP) and its metabolite 3-phenoxybenzaldehyde (3-PBA) in soils was investigated. In the laboratory, 80.5% and 73.1% of the initial dose of β-CP and 3-PBA (50 mg kg⁻¹) was removed in sterilized soils within 10 days, respectively, while in the same period, disappearance rate of β-CP and 3-PBA in non-sterilized soils was higher and reached 87.8% and 79.3%, respectively. Furthermore, the disappearance process followed the first-order kinetics and the half-life (T _1/2) for β-CP and 3-PBA reduced by 20.3–52.9 and 133.7–186.8 days, respectively, as compared to the controls. The addition of sucrose to the soils enhanced the ability of strain HP-S-01 to eliminate β-CP and 3-PBA. Similar results were observed in the field experiments. The introduced strain HP-S-01 quickly adapted to the environment and rapidly removed β-CP and 3-PBA without any lag phases in the field experiments. Compared with the controls, 47.9% and 67.0% of applied dose of β-CP and 3-PBA was removed from the soils without extra carbon sources and 52.5% and 73.3% of β-CP and 3-PBA was eliminated in soils supplemented with sucrose within 10 days, respectively. Analysis of β-CP degradation products in soil indicated that the tested strain transform β-CP to 3-PBA and α-hydroxy-3-phenoxy-benzeneacetonitrile. However, both intermediates were transient and they disappeared after 10 days. Therefore, the selected actinomyces strain HP-S-01 is suitable for the efficient and rapid bioremediation of β-CP contaminated soils.     

Genome-wide linkage mapping of yield-related traits in three Chinese bread wheat populations using high-density SNP markers

Key message

We identified 21 new and stable QTL, and 11 QTL clusters for yield-related traits in three bread wheat populations using the wheat 90 K SNP assay.

Abstract

Identification of quantitative trait loci (QTL) for yield-related traits and closely linked molecular markers is important in order to identify gene/QTL for marker-assisted selection (MAS) in wheat breeding. The objectives of the present study were to identify QTL for yield-related traits and dissect the relationships among different traits in three wheat recombinant inbred line (RIL) populations derived from crosses Doumai?×?Shi 4185 (D?×?S), Gaocheng 8901?×?Zhoumai 16 (G?×?Z) and Linmai 2?×?Zhong 892 (L?×?Z). Using the available high-density linkage maps previously constructed with the wheat 90 K iSelect single nucleotide polymorphism (SNP) array, 65, 46 and 53 QTL for 12 traits were identified in the three RIL populations, respectively. Among them, 34, 23 and 27 were likely to be new QTL. Eighteen common QTL were detected across two or three populations. Eleven QTL clusters harboring multiple QTL were detected in different populations, and the interval 15.5–32.3 cM around the Rht-B1 locus on chromosome 4BS harboring 20 QTL is an important region determining grain yield (GY). Thousand-kernel weight (TKW) is significantly affected by kernel width and plant height (PH), whereas flag leaf width can be used to select lines with large kernel number per spike. Eleven candidate genes were identified, including eight cloned genes for kernel, heading date (HD) and PH-related traits as well as predicted genes for TKW, spike length and HD. The closest SNP markers of stable QTL or QTL clusters can be used for MAS in wheat breeding using kompetitive allele-specific PCR or semi-thermal asymmetric reverse PCR assays for improvement of GY.

     

Molecular Characterization and Antimicrobial Susceptibility of Streptococcus pneumoniae Isolated from Children Hospitalized with Respiratory Infections in Suzhou,China

Background

Dissemination of antibiotic resistant clones is recognized as an important factor in the emergence and prevalence of resistance in pneumococcus. This study was undertaken to survey the antimicrobial susceptibility and serotypes distribution of pneumococci and to explore the circulating clones in hospitalized children in Suzhou, China.

Methods

The pneumococci were isolated from the nasopharyngeal aspirates of children less than 5 years of age admitted to Soochow-University-Affiliated-Children''s-Hospital with respiratory infections. The capsular serotypes were identified by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility was tested by E-test. The presence of ermB, mefA/E genes were detected by PCR and the genotypes were explored by Multilocus sequence typing (MLST).

Results

From July 2012 to July 2013, a total of 175 pneumococcal isolates were collected and all strains were resistant to erythromycin and clindamycin, about 39.4% strains were non-susceptible to penicillin G. Overall, 174 (99.4%) isolates were resistant to ≥3 types of antibiotics. Serotypes 19F (28.1%), 6B (19.7%), 19A (18.0%), and 23F (17.4%) were the most common serotypes in all identified strains. The serotypes coverage of PCV7 and PCV13 were 71.9% and 89.9%, respectively. Four international antibiotic-resistant clones, including Taiwan^19F-14 (n = 79), Spain^23F-1(n = 25), Taiwan^23F-15(n = 7) and Spain^6B-2(n = 7), were identified. The Taiwan^19F-14 clones have a higher non-susceptibility rate in β-lactams than other clones and non-clone isolates (p<0.001). In addition, 98.7% Taiwan^19F-14 clones were positive of both ermB and mefA/E genes, compare to 33.3% in other clones and non-clone strains.

Conclusions

The spread of international antibiotic-resistant clones, especially Taiwan^19F-14 clones, played a predominant role in the dissemination of antimicrobial resistant isolates in Suzhou, China. Considering the high prevalence of PCV7 serotypes and serotype 19A, the introduction of PCV13 may be a promising preventive strategy to control the increasing trend of clonal spread in China.     

Local activation of cardiac stem cells for post‐myocardial infarction cardiac repair

The prognosis of patients with myocardial infarction (MI) and resultant chronic heart failure remains extremely poor despite continuous advancements in optimal medical therapy and interventional procedures. Animal experiments and clinical trials using adult stem cell therapy following MI have shown a global improvement of myocardial function. The emergence of stem cell transplantation approaches has recently represented promising alternatives to stimulate myocardial regeneration. Regarding their tissue‐specific properties, cardiac stem cells (CSCs) residing within the heart have advantages over other stem cell types to be the best cell source for cell transplantation. However, time‐consuming and costly procedures to expanse cells prior to cell transplantation and the reliability of cell culture and expansion may both be major obstacles in the clinical application of CSC‐based transplantation therapy after MI. The recognition that the adult heart possesses endogenous CSCs that can regenerate cardiomyocytes and vascular cells has raised the unique therapeutic strategy to reconstitute dead myocardium via activating these cells post‐MI. Several strategies, such as growth factors, mircoRNAs and drugs, may be implemented to potentiate endogenous CSCs to repair infarcted heart without cell transplantation. Most molecular and cellular mechanism involved in the process of CSC‐based endogenous regeneration after MI is far from understanding. This article reviews current knowledge opening up the possibilities of cardiac repair through CSCs activation in situ in the setting of MI.     

仙客来的组织培养与快速繁殖

带香味鲜红颜色的仙客来在中国深受喜爱,尤其是带香味的仙客来变异株很难遇到,针对这一特点进行了仙客来的组培为大量繁殖带香味的仙客来提供了可能。另外嫩叶启动为今后更好地进行仙客来变异株的组培提供了依据。仙客来不仅有香味变异还有重瓣变异及花色变异,本次研究的只是有香味变异的组培技术。介绍了组培方法及管理注意事项。