Aristolochic acid I induced autophagy extenuates cell apoptosis via ERK 1/2 pathway in renal tubular epithelial cells

Autophagy is a lysosomal degradation pathway that is essential for cell survival and tissue homeostasis. However, limited information is available about autophagy in aristolochic acid (AA) nephropathy. In this study, we investigated the role of autophagy and related signaling pathway during progression of AAI-induced injury to renal tubular epithelial cells (NRK52E cells). The results showed that autophagy in NRK52E cells was detected as early as 3-6 hrs after low dose of AAI (10 μM) exposure as indicated by an up-regulated expression of LC3-II and Beclin 1 proteins. The appearance of AAI-induced punctated staining of autophagosome-associated LC3-II upon GFP-LC3 transfection in NRK52E cells provided further evidence for autophagy. However, cell apoptosis was not detected until 12 hrs after AAI treatment. Blockade of autophagy with Wortmannin or 3-Methyladenine (two inhibitors of phosphoinositede 3-kinases) or small-interfering RNA knockdown of Beclin 1 or Atg7 sensitized the tubular cells to apoptosis. Treatment of NRK52E cells with AAI caused a time-dependent increase in extracellular signal-regulated kinase 1 and 2 (ERK1/2) activity, but not c-Jun N-terminal kinase (JNK) and p38. Pharmacological inhibition of ERK1/2 phosphorylation with U0126 resulted in a decreased AAI-induced autophagy that was accompanied by an increased apoptosis. Taken together, our study demonstrated for the first time that autophagy occurred earlier than apoptosis during AAI-induced tubular epithelial cell injury. Autophagy induced by AAI via ERK1/2 pathway might attenuate apoptosis, which may provide a protective mechanism for cell survival under AAI-induced pathological condition.     

Research progress on the immune mechanism of the silkworm Bombyx mori

The silkworm Bombyx mori L., representing an important economic insect and one of the best models for studying insect immunity, possesses an efficient and sophisticated innate immune system against invasive microorganisms. The innate immune system basically includes humoural immunity and cellular immunity. The humoural immunity, which functions via molecules including humoural factors, lysozymes, phenoloxidase, hemolin, lectins and, in particular, antimicrobial peptides, plays a central role in eliminating the invading pathogens. The cellular immunity is primarily carried out and mediated by plasmatocytes and granular cells of haemocytes in the haemolymph, usually followed by melanization. Additionally, apoptosis, a primary viral defence for insects lacking adaptive immunity, comprises an important part of the silkworm immune system. Currently, there is still the lack of a comprehensive and systematic understanding of the molecular mechanisms of silkworm immunity. We review the latest research progress on silkworm immune mechanisms, including phenoloxidase‐dependent melanization and apoptosis, which is conducive to improving our understanding of the silkworm immune mechanism, clarifying the relationship of various immune mechanisms, and also providing a theoretical basis and reference for the future research of insect immunity.     

Examination of the quality of various force fields and solvation models for the equilibrium simulations of GA88 and GB88

Elucidating the relationship between sequence and conformation is essential for the understanding of functions of proteins. While sharing 88 % sequence identity and differing by only seven residues, GA88 and GB88 have completely different structures and serve as ideal systems for investigating the relationship between sequence and function. Benefiting from the continuous advancement of the computational ability of modern computers, molecular dynamics (MD) simulation is now playing an increasingly important role in the study of proteins. However, the reliability of MD simulations is limited by the accuracy of the force fields and solvent model approximations. In this work, several AMBER force fields (AMBER03, AMBER99SB, AMBER12SB, AMBER14SB, AMBER96) and solvent models (TIP3P, IGB5, IGB7, IGB8) have been employed in the simulations of GA88 and GB88. The statistical results from 19 simulations show that GA88 and GB88 both adopt more compact structures than the native structures. GB88 is more stable than GA88 regardless of the force fields and solvent models utilized. Most of the simulations overestimated the salt bridge interaction. The combination of AMBER14SB force field and IGB8 solvent model shows the best overall performance in the simulations of both GA88 and GB88. AMBER03 and AMBER12SB also yield reasonable results but only in the TIP3P explicit solvent model.     

Molecular cloning, characterization and expression of a C-type lectin cDNA in Chinese mitten crab, Eriocheir sinensis

C-type lectins are pattern-recognition proteins which are functionally important for pathogen recognition and immune regulation in vertebrates and invertebrates. In this study, a lectin cDNA named as Es-Lectin was cloned and characterized from the Chinese mitten crab, Eriocheir sinensis. The full-length sequence of this Es-Lectin cDNA was 651 bp, including an open reading frame of 483 bp encoding 160 amino acids. The predicted molecular weight of the Es-Lectin was 11.8 kDa. A typical signal peptide of 21 amino acids was deduced at the N-terminus of the predicted protein. This Es-Lectin belongs to a C-type lectin and contains six cysteines, a conserved EPN motif (Glu-Pro-Asn) and an imperfect WND (Trp-Asn-Asp) motif (FND, Phe-Asn-Asp). This Es-Lectin had 55% and 32% identity with other two C-type lectins in E. sinensis, and 29-36% homology with decapods. Although the Es-Lectin was also expressed in gill, hepatopancreas, intestine, muscle and stomach, its expression in haemocytes was the greatest. The expression of Es-Lectins in haemocytes increased at 1.5 h after the Aeromonas hydrophila challenge. After a slight decrease, the Es-Lectin expression in haemocytes significantly increased at 48 h post-challenge. The diverse distribution of Es-Lectin and its enhancement by bacterial challenge indicate that C-type lectins are important in the innate immune response to bacterial infection, and can be activated for innate immune response in crab at the initial stage after pathogen infection.     

Intergeneric protoplast fusion between Kluyveromyces and Saccharomyces cerevisiae – to produce sorbitol from Jerusalem artichokes

The construction of inulin-assimilating and sorbitol-producing fusants was achieved by intergeneric protoplast fusion between Kluyveromyces sp. Y-85 and Saccharomyces cerevisiae E-15. The cells of parental strains were pretreated with 0.1% EDTA (w/v) and 2-mercaptoethanol (0.1%, v/v) and then exposed to 2.0% (w/v) Zymolase at 30 °C for 30–40 min. The optimized fusion condition demonstrated that with the presence of 30% (w/v) polyethylene glycol 6000 (PEG-6000) and 10 mM CaCl₂ for 30 min, the fusion frequency reached 2.64 fusants/10⁶ parental cells. The fusants were screened by different characters between two parental strains and further identified by DNA contents, inulinase activity and sorbitol productivity. One of the genetically stable fusants, Strain F27, reached a maximal sorbitol production of 4.87 g/100 ml under optimal fermentation condition.     

SCNVSim: somatic copy number variation and structure variation simulator

Background

Somatically acquired structure variations (SVs) and copy number variations (CNVs) can induce genetic changes that are directly related to tumor genesis. Somatic SV/CNV detection using next-generation sequencing (NGS) data still faces major challenges introduced by tumor sample characteristics, such as ploidy, heterogeneity, and purity. A simulated cancer genome with known SVs and CNVs can serve as a benchmark for evaluating the performance of existing somatic SV/CNV detection tools and developing new methods.

Results

SCNVSim is a tool for simulating somatic CNVs and structure variations SVs. Other than multiple types of SV and CNV events, the tool is capable of simulating important features related to tumor samples including aneuploidy, heterogeneity and purity.

Conclusions

SCNVSim generates the genomes of a cancer cell population with detailed information of copy number status, loss of heterozygosity (LOH), and event break points, which is essential for developing and evaluating somatic CNV and SV detection methods in cancer genomics studies.     

Isolation,Identification and Characteristics of an Endophytic Quinclorac Degrading Bacterium Bacillus megaterium Q3

In this study, we isolated an endophytic quinclorac-degrading bacterium strain Q3 from the root of tobacco grown in quinclorac contaminated soil. Based on morphological characteristics, Biolog identification, and 16S rDNA sequence analysis, we identified strain Q3 as Bacillus megaterium. We investigated the effects of temperature, pH, inoculation size, and initial quinclorac concentration on growth and degrading efficiency of Q3. Under the optimal degrading condition, Q3 could degrade 93% of quinclorac from the initial concentration of 20 mg/L in seven days. We analyzed the degradation products of quinclorac using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The major degradation products by Q3 were different from those of previously identified quinclorac degrading strains, which suggests that Q3 may employ new pathways for quinclorac degradation. Our indoor pot experiments demonstrated that Q3 can effectively alleviate the quinclorac phytotoxicity in tobacco. As the first endophytic microbial that is capable of degrading quinclorac, Q3 can be a good bioremediation bacterium for quinclorac phytotoxicity.     

大鼠实验性脾虚证胰腺组织化学研究

用成年雄性Ｗｉｓｔａｒ大鼠３０只,分为（１）正常对照组,喂饲自来水。（２）脾虚组,用苦降破气中药和饮食失节法致成脾虚模型。（３）自然恢复组,动物致虚后,喂饲自来水。（４）中药治疗组。取四组动物胰腺进行ＲＮＡ,琥珀酸脱氢酶（ＳＤＨ）,乳酸脱氢酶（ＬＤＨ）,三磷酸腺苷酶（ＡＴＰａｓｅ）,葡萄糖－６－磷酸酶（Ｇ－６－Ｐａｓｅ）和硫胺素焦磷酸酶（ＴＰＰａｓｅ）组织化学反应和观察,并对ＳＤＨ,ＬＤＨ,ＲＮＡ进行了显微分光光度计定量测定。本研究结果表明,脾虚组胰腺泡细胞的ＲＮＡ,ＳＤＨ,ＡＴＰａｓｅ,Ｇ－６－Ｐａｓｅ,ＴＰＰａｓｅ含量和活性都低于对照组,而ＬＤＨ活性高于对照组。治疗组与自然恢复组相比,治疗组胰腺泡细胞以上指标接近对照组。定量测定与定性的结果一致。本研究表明,脾虚证时胰腺泡细胞上述几种酶活性和ＲＮＡ明显下降,可能在脾虚证发病中起主要作用,中药治疗有显著改善     

Intratumoral expression of IL-17 and its prognostic role in gastric adenocarcinoma patients

In this study, we characterized the intratumoral expression of IL-17 and CD8(+) TILs in gastric adenocarcinoma patients after resection and determined the correlation between the survival probability of gastric adenocarcinoma patients and the expression of IL-17 in tumor. Expression of IL-17 and CD8 was assessed by immunohistochemistry, and the prognostic effects of intratumoral IL-17 expression and CD8(+) TILs were evaluated by Cox regression and Kaplan-Meier analysis. Immunohistochemical detection revealed the presence of IL-17 and CD8(+) cells in gastric adenocarcinoma tissue samples (90.6%, 174 out of 192 patients and 96.9%, 186 out of 192 patients, respectively). We have also found that intratumoral IL-17 expression was significantly correlated with age (p=0.004) and that the number of CD8(+)TILs was significantly correlated with UICC staging (p=0.012) and the depth of tumor invasion (p=0.022). The five-year overall survival probability among patients intratumorally expressing higher levels of IL-17 was significantly better than those expressing lower levels of IL-17 (p=0.036). Multivariate Cox proportional hazard analyses revealed that intratumoral IL-17 expression (HR: 0.521; 95% CI: 0.329-0.823; p=0.005) was an independent factor affecting the five-year overall survival probability. We conclude that low levels of intratumoral IL-17 expression may indicate poor prognosis in gastric adenocarcinoma patients.