Protein kinase C delta null mice exhibit structural alterations in articular surface,intra-articular and subchondral compartments

IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users.     

Homology modeling threedimensional structure of AnxB1 and reducing its immunogenicity by sequence-deleted mutagenesis

AnxB1,a novel annexin previously isolated from Cysticercus cellulose,shows high thrombi affinity and anticoagulant activity in vivo.In order to investigate the relationship between structure and biological function,a predicted three-dimensional(3D)model of AnxB1 was generated by homology modeling.This model contains four homologous internal-domains and the Cα trace of domain Ⅰ,Ⅱ and IV shows high similarity.Based on the structure characterization,four sequence-deleted mutants were constructed and expressed as GST fusion proteins in E.coli.Two of the mutants,GST-M3 and GST-M4 reserved high anticoagulant activity(p＜0.01 vs.GST).Furthermore,compared with the wild type GST-AnxB1,the immunogenicity of GST-M3 and GST-M4 was reduced significantly(p＜0.01)and the molecular weight was lowered to 27 kD and 34 kD,respectively.These observations laid a solid foundation for further study on developing new thrombolytic agents with higher efficiency and lower side effect.     

Antiviral flavonoids from the root bark of Morus alba L

A prenylated flavonoid, moralbanone, along with seven known compounds kuwanon S, mulberroside C, cyclomorusin, eudraflavone B hydroperoxide, oxydihydromorusin, leachianone G and alpha-acetyl-amyrin were isolated from the root bark of Morus alba L. Leachianone G showed potent antiviral activity (IC(50) = 1.6 microg/ml), whereas mulberroside C showed weak activity (IC(50) = 75.4 microg/ml) against herpes simplex type 1 virus (HSV-1). Their structures were elucidated by spectroscopic methods.     

芒果APl同源基因的克隆及其生物信息学分析

我们采用RT-PCR方法克隆了2个APl同源基因全长cDNA,分别命名为MAPl-1(GenBank accession No.FJ529206)和MAPl-2(GenBank accession No.FJ529207).MAPl-1编码247个氨基酸,开放阅读框长度为741 bp,蛋白质分子量为28.54kD,等电点为8.31;MAPl-2编码248个氨基酸,开放阅读框长度为744 bp,蛋白质分子量为28.78 kD,等电点为8.70.同源性分析表明,它们的核苷酸序列与其它木本植物APl同源基因的一致性为72%～81%.实验分析表明,MAPl-1和MAPl-2第1至第61个氨基酸含有一个MADS盒结构域,第88至第178个为K盒结构域;两个基因均定位于细胞核,且功能位点分布存在着不同,推测这两个基因在花器官发育过程中的功能存在差异.蛋白二级结构预测显示,MAPl-1蛋白有12个a-螺旋,4个β折叠区,14个β-转角;而MAPl-2蛋白有11个a-螺旋,5个β折叠区,15个β-转角:其大多数氨基酸具有亲水性.本研究有助于进一步了解芒果的开花分子机理及成花的生物学发育阶段.     

藕莲有性繁殖栽培

根据莲(Nelumbo nucifera)生物学特性,既可用藕作种进行无性繁殖,也可用种子播种进行有性繁殖。藕莲在我国有数千年的栽培历史,但素以无性系栽培。尚未见到有性繁殖栽培的报道。作者自1980年起进行了有性繁殖栽培试验。       

Targeting NADPH Oxidase and Phospholipases A2 in Alzheimer’s Disease

Alzheimer’s disease (AD) is marked by an increase in the production of extracellular beta amyloid plaques and intracellular neurofibrillary tangles associated with a decline in brain function. Increases in oxidative stress are regarded as an early sign of AD pathophysiology, although the source of reactive oxygen species (ROS) and the mechanism(s) whereby beta amyloid peptides (Aβ) impact oxidative stress have not been adequately investigated. Recent studies provide strong evidence for the involvement of NADPH oxidase and its downstream oxidative signaling pathways in the toxic effects elicited by Aβ. ROS produced by NADPH oxidase activate multiple signaling pathways leading to neuronal excitotoxicity and glial cell-mediated inflammation. This review describes recent studies demonstrating the neurotoxic effects of Aβ in conjunction with ROS produced by NADPH oxidase and the downstream pathways leading to activation of cytosolic phospholipase A₂ (PLA₂) and secretory PLA₂. In addition, this review also describes recent studies using botanical antioxidants to protect against oxidative damage associated with AD. Investigating the metabolic and signaling pathways involving Aβ NADPH oxidase and PLA₂ can help understand the mechanisms underlying the neurodegenerative effects of oxidative stress in AD. This information should provide new therapeutic approaches for prevention of this debilitating disease.     

Identification of salt-stress responsive genes in rice (Oryza sativa L.) by cDNA array

To identify salt stress-responsive genes, we constructed a cDNA library with the salttolerant rice cultivar, Lansheng. About 15000 plasmids were extracted and dotted on filters with Biomeck 2000 HDRT system or by hand. Thirty genes were identified to display altered expression levels responding to 150 mmol/L NaCl. Among them eighteen genes were up-regulated and the remainders downregulated. Twenty-seven genes have their homologous genes in GenBank Databases. The expression of twelve genes was studied by Northern analysis. Based on the functions, these genes can be classified into five categories, including photosynthesis-related gene, transportrelated gene, metabolismrelated gene, stress-or resistancerelated gene and the others with various functions. The results showed that salt stress influenced many aspects of rice growth. Some of these genes may play important roles in plant salt tolerance.