Augmenter of liver regeneration inhibits TGF-β1-induced renal tubular epithelial-to-mesenchymal transition via suppressing TβR II expression in vitro

Tubular epithelial-to-mesenchymal transition (EMT) plays a crucial role in the progression of renal tubular interstitial fibrosis (TIF), which subsequently leads to chronic kidney disease (CKD) and eventually, end-stage renal disease (ESRD). We propose that augmenter of liver regeneration (ALR), a member of the newly discovered ALR/Erv1 protein family shown to ameliorate hepatic fibrosis, plays a similar protective role in renal tubular cells and has potential as a new treatment option for CKD. Here, we showed that recombinant human ALR (rhALR) inhibits EMT in renal tubular cells by antagonizing activation of the transforming growth factor-β1 (TGF-β1) signaling pathway. Further investigation revealed that rhALR suppresses the expression of TGF-β receptor type II (TβR II) and significantly alleviates TGF-β1-induced phosphorylation of Smad2 and nuclear factor-κB (NF-κB). No apparent adverse effects were observed upon the addition of rhALR alone to cells. These findings collectively suggest that ALR plays a role in inhibiting progression of renal tubular EMT, supporting its potential utility as an effective antifibrotic strategy to reverse TIF in CKD.     

Highly efficient genotyping of rice biparental populations by GoldenGate assays based on parental resequencing

Key message

A new time- and cost-effective strategy was developed for medium-density SNP genotyping of rice biparental populations, using GoldenGate assays based on parental resequencing.

Abstract

Since the advent of molecular markers, crop researchers and breeders have dedicated huge amounts of effort to detecting quantitative trait loci (QTL) in biparental populations for genetic analysis and marker-assisted selection (MAS). In this study, we developed a new time- and cost-effective strategy for genotyping a population of progeny from a rice cross using medium-density single nucleotide polymorphisms (SNPs). Using this strategy, 728,362 “high quality” SNPs were identified by resequencing Teqing and Lemont, the parents of the population. We selected 384 informative SNPs that were evenly distributed across the genome for genotyping the biparental population using the Illumina GoldenGate assay. 335 (87.2 %) validated SNPs were used for further genetic analyses. After removing segregation distortion markers, 321 SNPs were used for linkage map construction and QTL mapping. This strategy generated SNP markers distributed more evenly across the genome than previous SSR assays. Taking the GW5 gene that controls grain shape as an example, our strategy provided higher accuracy (0.8 Mb) and significance (LOD 5.5 and 10.1) in QTL mapping than SSR analysis. Our study thus provides a rapid and efficient strategy for genetic studies and QTL mapping using SNP genotyping assays.     

Effects of Metal Ions on Stability and Activity of Hyperthermophilic Pyrolysin and Further Stabilization of This Enzyme by Modification of a Ca2+-Binding Site

Pyrolysin is an extracellular subtilase produced by the marine hyperthermophilic archaeon Pyrococcus furiosus. This enzyme functions at high temperatures in seawater, but little is known about the effects of metal ions on the properties of pyrolysin. Here, we report that the supplementation of Na⁺, Ca²⁺, or Mg²⁺ salts at concentrations similar to those in seawater destabilizes recombinant pyrolysin but leads to an increase in enzyme activity. The destabilizing effect of metal ions on pyrolysin appears to be related to the disturbance of surface electrostatic interactions of the enzyme. In addition, mutational analysis of two predicted high-affinity Ca²⁺-binding sites (Ca1 and Ca2) revealed that the binding of Ca²⁺ is important for the stabilization of this enzyme. Interestingly, Asn substitutions at residues Asp818 and Asp820 of the Ca2 site, which is located in the C-terminal extension of pyrolysin, resulted in improvements in both enzyme thermostability and activity without affecting Ca²⁺-binding affinity. These effects were most likely due to the elimination of unfavorable electrostatic repulsion at the Ca2 site. Together, these results suggest that metal ions play important roles in modulating the stability and activity of pyrolysin.     

Descriptions of two new record species of Scutellonema (Nematoda：Tylenchida) from China

From 2011 to 2012, we collected Scutellonema commune from the rhizosphere soil of coconut(cocos nucifera L.) and Scutellonema magniphasma from the rhizosphere soil of Rosa chinensis in Shenyang, China. S. commune was characterized by rounded scutella, which was varied from two annules anterior to the anus and five annules posterior. The lateral field was not areolated at the level of scutella. S. magniphasma was characterized by varying scutellum, about 7.0 μm in diameter, in position from four annules posterior to four annules anterior to the anus, and areolated at the level of the scutellum.     

Population genetic structure of endangered Mongolian racerunner (Eremias argus) from the Korean Peninsula

The Mongolian racerunner (Eremias argus) is a small lacertid lizard species, and its distribution range encompasses the Korean Peninsula, Mongolia, China and Russia. Eremias argus is widespread, but populations on the Korean Peninsula are small and declining, provoking concerns that genetic diversity is being lost. This species is currently listed under the Protection of Wild Fauna and Flora Act in South Korea. In this study, nine novel microsatellites for E. argus were developed with a biotin-enrichment method and used to understand its population genetic structure and delineate conservation units on the Korean Peninsula. Overall, low intrapopulation genetic diversity was observed (mean number of alleles per locus = 2.463; mean H _E = 0.398) from 10 populations investigated (n = 110). Two populations (among five with n≥ 10) showed an excess of heterozygosity expected under HWE relative to that expected at mutation-drift equilibrium, indicating severe reduction in population sizes. With only a few exceptions, the overall genetic differentiation among populations was substantial with the high levels of pairwise-F _ST (0.006–0.746) and -R _ST (0.034–0.940) values. The results of Bayesian STRUCTURE analysis showed that E. argus populations on the Korean Peninsula were most likely partitioned into three genetic clusters. Taken all together, such low levels of gene flow and strong genetic structuring have critical implications for the conservation of this endangered species and its management.     

The genetic structure of the A mating-type locus of Lentinula edodes

The Shiitake mushroom, Lentinula edodes (Berk.) Pegler is a tetrapolar basidiomycete with two unlinked mating-type loci, commonly called the A and B loci. Identifying the mating-types in shiitake is important for enhancing the breeding and cultivation of this economically-important edible mushroom. Here, we identified the A mating-type locus from the first draft genome sequence of L. edodes and characterized multiple alleles from different monokaryotic strains. Two intron-length polymorphism markers were developed to facilitate rapid molecular determination of A mating-type. L. edodes sequences were compared with those of known tetrapolar and bipolar basidiomycete species. The A mating-type genes are conserved at the homeodomain region across the order Agaricales. However, we observed unique genomic organization of the locus in L. edodes which exhibits atypical gene order and multiple repetitive elements around its A locus. To our knowledge, this is the first known exception among Homobasidiomycetes, in which the mitochondrial intermediate peptidase (mip) gene is not closely linked to A locus.     

DNA条形码技术在河北保定、廊坊地区鳞翅目昆虫上的应用及小型区域数据库的构建

【目的】为了探究DNA条形码技术和小型区域数据库在蛾类鉴定上的可行性,本研究利用条形码通用引物扩增了采自河北保定、廊坊地区10种夜蛾82个样本的线粒体细胞色素c氧化酶亚基I(Mitochondrial cytochrome c oxidase subunit I,COⅠ)基因序列。【方法】基于进化树、距离、阈值和特征的方法。【结果】虽然整体分类效果较好,但基于进化树、距离、阈值的方法都无法将二点委夜蛾Athetis lepigone进行较好的分类;样本LF110802.008总是被分入标瑙夜蛾Maliattha signifera类群,与形态学分类结果发生分歧。基于特征的方法运用核基因28S进行分析,结果与形态分类一致。同时还探讨了基于特征方法得到的诊断特征数目与样本数量之间的关系,发现两者密切相关;基于特征的方法对小样本量的鉴定也比较有效。本研究建立了小型区域的DNA条形码数据库,使物种识别具有更强的针对性,有利于提高地区性蛾类病虫害防治效果。【结论】在蛾类鉴定中,DNA条形码有很好的分类效果,小型区域数据库很有实际应用价值。     

(−)-Epigallocatechin-3-Gallate Ameliorates Learning and Memory Deficits by Adjusting the Balance of TrkA/p75NTR Signaling in APP/PS1 Transgenic Mice

Alzheimer's disease (AD) is pathologically characterized by deposition of β-amyloid (Aβ) peptides, which closely correlates with the balance of nerve growth factor (NGF)-related TrkA/p75^NTR signaling. (?)-Epigallocatechin-3-gallate (EGCG) is used for prevention and treatment of many neurodegenerative diseases, including AD. However, whether the neuroprotective effects of EGCG treatment were via modulating the balance of TrkA/p75^NTR signaling was still unknown. In this study, we found that EGCG treatment (2 mg · kg ^–1 · day ^–1) dramatically ameliorated the cognitive impairments, reduced the overexpressions of Aβ(1–40) and amyloid precursor protein (APP), and inhibited the neuronal apoptosis in the APP/PS1 mice. Interestingly, the EGCG treatment enhanced the relative expression level of NGF by increasing the NGF/proNGF ratio in the APP/PS1 mice. Moreover, after EGCG treatment, TrkA signaling was activated by increasing the phosphorylation of TrkA following the increased phosphorylation of c-Raf, ERK1/2, and cAMP response element-binding protein (CREB), simultaneously the p75^NTR signaling was significantly inhibited by decreasing the p75^ICD expression, JNK2 phosphorylation, and cleaved-caspase 3 expression, so that the Aβ deposits and neuronal apoptosis in the hippocampus were inhibited.