罗氏沼虾MrLc3a基因cDNA的克隆及在副溶血弧菌胁迫下的表达分析

虾类和果蝇同属节肢动物.果蝇的相关研究表明自噬与免疫关系密切,而虾类自噬机制研究鲜少.微管相关蛋白1轻链3 (microtubule-associated protein 1 light chain 3,Lc3)与自噬基因Atg8同源,其与自噬体的形成密切相关,是自噬活性的标志分子.本研究利用RACE技术克隆了罗氏沼虾的MrLc3a基因的全长cDNA,用RT-qPCR检测了该基因在罗氏沼虾主要组织中的表达量;并研究了正常和副溶血弧菌感染两种情况下MrLc3a基因和免疫基因Relish的表达变化情况,为其在病害防御方面的应用提供了前期数据.试验结果表明:MrLc3a基因全长653 bp,其中包括195 bp的5'-UTR、378 bp的ORF开放阅读框和80 bp的3'-UTR,共编码126个氨基酸;序列比对结果显示,其编码的氨基酸序列和南美白对虾Lc3a编码的氨基酸序列具有较高的同源性,并在系统发育树上聚为一支;RT-qPCR结果显示,MrLc3a基因在罗氏沼虾各个组织均有表达,其中在脑、鳃、胃中的表达量较高,在肝胰腺和性腺中的表达量较少;副溶血弧菌感染罗氏沼虾后显著影响了MrLc3a和Relish基因在罗氏沼虾肝胰腺组织中的转录情况,MrLc3a和Relish基因随时间变化都呈现出先上升后下降的趋势,表明MrLc3a基因通过参与细胞自噬过程而参与了免疫反应.     

OSMRβ mutants enhance basal keratinocyte differentiation via inactivation of the STAT5/KLF7 axis in PLCA patients

Dear Editor, Primary localized cutaneous amyloidosis (PLCA) is a skin-limited disorder characterized by deposition of amyloid material in the superficial dermis.According to clinical characteristics,PLCA is divided into lichen,macular,and nodular amyloidosis.PLCA is found worldwide but has a higher incidence in South America and Southeast Asia,such as in Brazil and China (Chang et al.,2014;Tey et al.,2016).     

Gentiopicroside promotes the osteogenesis of bone mesenchymal stem cells by modulation of β-catenin-BMP2 signalling pathway

Osteoporosis is characterized by increased bone fragility, and the drugs used at present to treat osteoporosis can cause adverse reactions. Gentiopicroside (GEN), a class of natural compounds with numerous biological activities such as anti-resorptive properties and protective effects against bone loss. Therefore, the aim of this work was to explore the effect of GEN on bone mesenchymal stem cells (BMSCs) osteogenesis for a potential osteoporosis therapy. In vitro, BMSCs were exposed to GEN at different doses for 2 weeks, whereas in vivo, ovariectomized osteoporosis was established in mice and the therapeutic effect of GEN was evaluated for 3 months. Our results in vitro showed that GEN promoted the activity of alkaline phosphatase, increased the calcified nodules in BMSCs and up-regulated the osteogenic factors (Runx2, OSX, OCN, OPN and BMP2). In vivo, GEN promoted the expression of Runx2, OCN and BMP2, increased the level of osteogenic parameters, and accelerated the osteogenesis of BMSCs by activating the BMP pathway and Wnt/β-catenin pathway, effect that was inhibited using the BMP inhibitor Noggin and Wnt/β-catenin inhibitor DKK1. Silencing the β-catenin gene and BMP2 gene blocked the osteogenic differentiation induced by GEN in BMSCs. This block was also observed when only β-catenin was silenced, although the knockout of BMP2 did not affect β-catenin expression induced by GEN. Therefore, GEN promotes BMSC osteogenesis by regulating β-catenin-BMP signalling, providing a novel strategy in the treatment of osteoporosis.     

Correction to: Genetic dissection of maize disease resistance and its applications in molecular breeding

Molecular Breeding - The ‘Honeycrisp’ apple, an economically important cultivar and breeding parent, is prone to soft scald and soggy breakdown postharvest physiological disorders....     

Left ventricular wall stress compendium

Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.     

Expression of Nemo-Like Kinase (NLK) in the Brain in a Rat Experimental Subarachnoid Hemorrhage Model

This study aimed to investigate the expression of the Nemo-like kinase (NLK) in the brain after experimental subarachnoid hemorrhage (SAH) in rats. A total of 90 rats were randomly divided into six groups: control group, day 1, day 3, day 5, day 7, and day 14. Day 1, day 3, day 5, day 7, and day 14 groups were all SAH groups in which the rats were killed on days 1, 3, 5, 7, and 14, respectively. In SAH groups, autologous arterial blood was injected into cisterna magna once on day 0. Cross-sectional area of basilar artery was measured by H&E staining. Immunostaining and immunoblotting experiments were performed to detect the expression of NLK protein. Real-time polymerase chain reaction was used to analyze the presence and quantity of NLK mRNA. The level of oxidative stress in the artery was also measured. The basilar arteries exhibited vasospasm after SAH and became the most severe on day 3. The expressions of NLK protein and mRNA were decreased remarkably in SAH groups compared with the control group. The down-regulated expression of NLK was detected after SAH and the low ebb was on day 3, which was oppositely the peak time of oxidative stress. The expression of NLK was present mainly in the neurons in the brain and smooth muscle cells in the basilar artery. NLK is decreasingly expressed in an opposite time-course to the development of cerebral vasospasm (CVS) and SAH-induced brain injury in this rat experimental model of SAH and these findings might have important implications during the administration of specific NLK agonist to prevent or reduce CVS or neuronal apoptosis caused by SAH.     

MFG-E8 and HMGB1 Are Involved in the Mechanism Underlying Alcohol-Induced Impairment of Macrophage Efferocytosis

Efferocytosis is a unique phagocytic process for macrophages to remove apoptotic cells in inflammatory loci. This event is maintained by milk fat globule-EGF factor 8 (MFG-E8), but attenuated by high mobility group box 1 (HMGB1). Alcohol abuse causes injury and inflammation in multiple tissues. It alters efferocytosis, but precise molecular mechanisms for this effect remain largely unknown. Here, we showed that acute exposure of macrophages to alcohol (25 mmol/L) inhibited MFG-E8 gene expression and impaired efferocytosis. The effect was mimicked by hydrogen peroxide. Moreover, N-acetylcysteine (NAC), a potent antioxidant, blocked acute alcohol effect on inhibition of macrophage MFG-E8 gene expression and efferocytosis. In addition, recombinant MFG-E8 rescued the activity of alcohol-treated macrophages in efferocytosis. Together, the data suggest that acute alcohol exposure impairs macrophage efferocytosis via inhibition of MFG-E8 gene expression through a reactive oxygen species dependent mechanism. Alcohol has been found to suppress or exacerbate immune cell activities depending on the length of alcohol exposure. Thus, we further examined the role of chronic alcohol exposure on macrophage efferocytosis. Interestingly, treatment of macrophages with alcohol for seven days in vitro enhanced MFG-E8 gene expression and efferocytosis. However, chronic feeding of mice with alcohol caused increase in HMGB1 levels in serum. Furthermore, HMGB1 diminished efferocytosis by macrophages that were treated chronically with alcohol, suggesting that HMGB1 might attenuate the direct effect of chronic alcohol on macrophage efferocytosis in vivo. Therefore, we speculated that the balance between MFG-E8 and HMGB1 levels determines pathophysiological effects of chronic alcohol exposure on macrophage efferocytosis in vivo.