Mast cells dysregulate apoptotic and cell cycle genes in mucosal squamous cell carcinoma

Background  

Mucosal squamous cell carcinoma of the head and neck is a disease of high mortality and morbidity. Interactions between the squamous cell carcinoma and the host's local immunity, and how the latter contributes to the biological behavior of the tumor are unclear. In vivo studies have demonstrated sequential mast cell infiltration and degranulation during squamous cell carcinogenesis. The degree of mast cell activation correlates closely with distinct phases of hyperkeratosis, dysplasia, carcinoma in-situ and invasive carcinoma. However, the role of mast cells in carcinogenesis is unclear.     

Directed evolution of poly[(R)-3-hydroxybutyrate] depolymerase using cell surface display system: functional importance of asparagine at position 285

Poly[(R)-3-hydroxybutyrate] (PHB) depolymerase from Ralstonia pickettii T1 (PhaZ_RpiT1) consists of three functional domains to effectively degrade solid PHB materials, and its catalytic domain catalyzes the ester bond cleavage of the substrate. We performed the directed evolution of PhaZ_RpiT1 targeted at the catalytic domain in combination with the cell surface display method to effectively screen for mutants with improved p-nitrophenyl butyrate (pNPC4) activity. Mutated PhaZ_RpiT1 genes generated by error-prone PCR were fused to the oprI gene to display them as fusion proteins on Escherichia coli cell surface. Some cells displaying the mutant enzymes showed a two- to fourfold increase in pNPC4 hydrolysis activity relative to cells displaying wild-type enzyme. These mutant genes were recombined by a staggered extension process and the recombined enzymes were displayed to result in a five- to eightfold higher pNPC4 hydrolysis activity than the wild type. To further evaluate the mutation effects, unfused and undisplayed enzymes were prepared and applied to the hydrolysis of p-nitrophenyl esters having different chain lengths (pNPCn; n?=?2–6) and PHB degradation. One specific second-generation mutant showed an approximately tenfold increase in maximum rate for pNPC3 hydrolysis, although its PHB degradation efficiency at 1 μg/mL of enzyme concentration was approximately 3.5-fold lower than that of the wild type. Gene analysis showed that N285D or N285Y mutations were found in six of the seven improved second-generation mutants, indicating that Asn285 probably participates in the regulation of substrate recognition and may be more favorable for PHB degradation process than other amino acid residues.     

莲叶桐对热带珊瑚岛环境的生理生态适应性

为探究莲叶桐(Hernandia nymphaeifolia)对热带珊瑚岛季节性干旱、强光、盐碱等环境的生理生态适应性,该文对海南省文昌市试验苗圃(以下简称文昌苗圃)和移栽到热带珊瑚岛的莲叶桐的叶片形态解剖结构、抗氧化能力、抗逆渗透物质含量和光合色素等进行了研究.结果表明:(1)与文昌苗圃相比,莲叶桐在移栽到热带珊瑚岛...     

S-Nitrosoglutathion Reductase Activity Modulates the Thermotolerance of Seeds Germination by Controlling ABI5 Stability under High Temperature

Seed germination or dormancy status is strictly controlled by endogenous phytohormone and exogenous environment signals. Abscisic acid (ABA) is the important phytohormone to suppress seed germination. Ambient high temperature (HT) also suppressed seed germination, or called as secondary seed dormancy, through upregulating ABI5, the essential component of ABA signal pathway. Previous result shows that appropriate nitric oxide (NO) breaks seed dormancy through triggering S-nitrosoglutathion reductase (GSNOR1)-dependent S-nitrosylation modification of ABI5 protein, subsequently inducing the degradation of ABI5. Here we found that HT induced the degradation of GSNOR1 protein and reduced its activity, thus accumulated more reactive nitrogen species (RNS) to damage seeds viability. Furthermore, HT increased the S-nitrosylation modification of GSNOR1 protein, and triggered the degradation of GSNOR1, therefore stabilizing ABI5 to suppress seed germination. Consistently, the ABI5 protein abundance was lower in the transgenic line overexpressing GSNOR1, but higher in the gsnor mutant after HT stress. Genetic analysis showed that GSNOR1 affected seeds germination through ABI5 under HT. Taken together, our data reveals a new mechanism by which HT triggers the degradation of GSNOR1, and thus stabilizing ABI5 to suppress seed germination, such mechanism provides the possibility to enhance seed germination tolerance to HT through genetic modification of GNSOR1.     

Escaping introns in COI through cDNA barcoding of mushrooms: Pleurotus as a test case

DNA barcoding involves the use of one or more short, standardized DNA fragments for the rapid identification of species. A 648‐bp segment near the 5′ terminus of the mitochondrial cytochrome c oxidase subunit I (COI) gene has been adopted as the universal DNA barcode for members of the animal kingdom, but its utility in mushrooms is complicated by the frequent occurrence of large introns. As a consequence, ITS has been adopted as the standard DNA barcode marker for mushrooms despite several shortcomings. This study employed newly designed primers coupled with cDNA analysis to examine COI sequence diversity in six species of Pleurotus and compared these results with those for ITS. The ability of the COI gene to discriminate six species of Pleurotus, the commonly cultivated oyster mushroom, was examined by analysis of cDNA. The amplification success, sequence variation within and among species, and the ability to design effective primers was tested. We compared ITS sequences to their COI cDNA counterparts for all isolates. ITS discriminated between all six species, but some sequence results were uninterpretable, because of length variation among ITS copies. By comparison, a complete COI sequences were recovered from all but three individuals of Pleurotus giganteus where only the 5′ region was obtained. The COI sequences permitted the resolution of all species when partial data was excluded for P. giganteus. Our results suggest that COI can be a useful barcode marker for mushrooms when cDNA analysis is adopted, permitting identifications in cases where ITS cannot be recovered or where it offers higher resolution when fresh tissue is. The suitability of this approach remains to be confirmed for other mushrooms.     

大鼠不同心肌肥厚模型左心室基因表达谱变化的比较

为了解心肌肥厚时基因表达谱的变化规律,本实验复制了三种大鼠心肌肥厚模型：肾上腹主动脉缩窄(suprarenal abdominal aortic stenosis,SRS)、动静脉瘘(arterial-vein fistula,AVF)和去甲。肾上腺素持续静脉输注(jugular vein infusion of norepinephrine,NEi),并应用组织化学方法和超声心动术检测大鼠心脏结构和功能指标,应用cDNA基因芯片技术检测心脏基因表达水平的变化。SRS和NEi引起大鼠向心性心肌肥厚,AVF引起大鼠离心性心肌肥厚,其中NEi大鼠心肌纤维化明显。对不同心肌肥厚模型间大鼠左心室基因表达谱的变化进行两两比较。结果显示,有部分基因在不同模型中表达水平均发生变化,其中多数基因在两种模型中表达水平改变的方向相同,也有少部分基因在两种模型中表达水平改变方向相反。综合比较三种心肌肥厚模型的基因表达谱,各种模型都有特异的基因表达变化,但是有19个基因在三种心肌肥厚模型中表达水平均发生改变。研究结果有可能成为心肌肥厚的标志性基因或治疗靶点,为心肌肥厚发生机制的深入研究提供了新的线索。     

Investigations of peptide hydration using NMR and molecular dynamics simulations: A study of effects of water on the conformation and dynamics of antamanide

Summary The influence of water binding on the conformational dynamics of the cyclic decapeptide antamanide dissolved in the model lipophilic environment chloroform is investigated by NMR relaxation measurements. The water-peptide complex has a lifetime of 35 s at 250 K, which is longer than typical lifetimes of water-peptide complexes reported in aqueous solution. In addition, there is a rapid intracomplex mobility that probably involves librational motions of the bound water or water molecules hopping between different binding sites. Water binding restricts the flexibility of antamanide. The experimental findings are compared with GROMOS molecular dynamics simulations of antamanide with up to eight bound water molecules. Within the simulation time of 600 ps, no water molecule leaves the complex. Additionally, the simulations show a reduced flexibility for the complex in comparison with uncomplexed antamanide. Thus, there is a qualitative agreement between the experimental NMR results and the computer simulations.     

Change in mutagenic activity of genistein after a nitrite treatment

This study examined the mutagenic activity of genistein after a nitrite treatment under acidic conditions. Nitrite-treated genistein exhibited mutagenic activity toward Salmonella typhimurium strains TA 100 and TA 98 with or without S9 mix. Nitrite-treated genistein was demonstrated by electron spin resonance to generate radicals. An instrumental analysis showed 3'-nitro-genistein to have been formed in the reaction mixture. However, 3'-nitro-genistein did not exhibit mutagenic activity toward the S. typhimurium strains, suggesting that other mutagens might also have been formed in the reaction mixture. The clastogenic properties of nitrite-treated genistein and 3'-nitro-genistein were examined by a micronucleus test with male ICR mice. Nitrite-treated genistein and 3'-nitro-genistein showed a significantly higher frequency of micronucleated reticulocytes in mice than in the control group. These results suggest that a daily oral intake of genistein and nitrite through foodstuffs might induce the formation of various mutagenic compounds in the body.     

Synergistic inhibitory effect of berberine and icotinib on non-small cell lung cancer cells via inducing autophagic cell death and apoptosis

Apoptosis - Resistance to epidermal growth factor receptor-tyrosin kinase inhibitors (TKIs, e.g. icotinib) remains a major clinical challenge. Non-small cell lung cancer patients with wild-type...