Structural and Biophysical Characterization of the Interactions between the Death Domain of Fas Receptor and Calmodulin

The extrinsic apoptotic pathway is initiated by cell surface death receptors such as Fas. Engagement of Fas by Fas ligand triggers a conformational change that allows Fas to interact with adaptor protein Fas-associated death domain (FADD) via the death domain, which recruits downstream signaling proteins to form the death-inducing signaling complex (DISC). Previous studies have shown that calmodulin (CaM) is recruited into the DISC in cholangiocarcinoma cells, suggesting a novel role of CaM in Fas-mediated signaling. CaM antagonists induce apoptosis through a Fas-related mechanism in cholangiocarcinoma and other cancer cell lines possibly by inhibiting Fas-CaM interactions. The structural determinants of Fas-CaM interaction and the underlying molecular mechanisms of inhibition, however, are unknown. Here we employed NMR and biophysical techniques to elucidate these mechanisms. Our data show that CaM binds to the death domain of Fas (FasDD) with an apparent dissociation constant (K_d) of ∼2 μm and 2:1 CaM:FasDD stoichiometry. The interactions between FasDD and CaM are endothermic and entropically driven, suggesting that hydrophobic contacts are critical for binding. We also show that both the N- and C-terminal lobes of CaM are important for binding. NMR and surface plasmon resonance data show that three CaM antagonists (N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide, tamoxifen, and trifluoperazine) greatly inhibit Fas-CaM interactions by blocking the Fas-binding site on CaM. Our findings provide the first structural evidence for Fas-CaM interactions and mechanism of inhibition and provide new insight into the molecular basis for a novel role of CaM in regulating Fas-mediated apoptosis.     

Polymorphism of angiotensinogen gene M235T in myocardial infarction and brain infarction: a meta-analysis

The angiotensinogen (AGT) gene M235T polymorphism has been reported to be associated with myocardial infarction (MI) and brain infarction (BI), but the results remain inconclusive. This meta-analysis was designed to clarify these controversies. Electronic databases were systematically searched before February 2013. A total of 38 studies with 17304 subjects met our inclusion criteria. In East Asian group, significant association was found between AGT M235T polymorphism and risk of MI (for dominant model: OR = 1.79; 95% CI = 1.04–3.06; for recessive model OR = 2.01; 95% CI = 1.21–3.36; for additive model OR = 1.79; 95% CI = 1.14–2.86) as well as BI (for dominant model: OR = 1.66; 95% CI = 1.22–2.27; for recessive model OR = 1.78, 95% CI = 1.29–2.46; for additive model: OR = 1.64, 95% CI = 1.34–2.00), while the M235T polymorphism did not impact the risk of MI in total population and other ethnicity. In the subgroup analyses by gender and age, there was lack of evidence for the association. This meta-analysis suggested an association between the M235T polymorphism and MI as well as BI in East Asian population. Further studies with larger numbers of worldwide participants are needed to understand the genetic basis of MI and BI.     

不同波段电磁辐射对大鼠Sertoli细胞雄激素受体和卵泡刺激素受体表达的影响

探讨不同波段电磁辐射对大鼠睾丸Sertoli细胞雄激素受体(androgen receptor,AR)和卵泡刺激素受体(follicle stimulating hormone receptor,FSHR)表达的影响。原代培养的Sertoli细胞分别经场强6×104 V/m的电磁脉冲(electromagnetic pulse,EMP)、平均功率密度为100 mW/cm2的S波段微波(S-band high power microwave,S-HPM)和X波段微波(X-bandhigh power microwave,X-HPM)辐射4 min。应用real-time RT-PCR和Western blot方法检测Sertoli细胞AR的表达,结果显示具有不同程度的降低(P<0.05,P<0.01);Wistar大鼠分别经S-HPM、X-HPM和EMP照射20 min,应用免疫组化方法检测睾丸组织AR的表达,发现辐射后7 d有显著降低(P<0.05,P<0.01)。三者比较,AR的表达总体呈EMP>X-HPM>S-HPM的趋势,而FSHR的表达无明显变化。Sertoli细胞AR表达的变化,可能参与了电磁辐射致...     

Light Spatial Distribution in the Canopy and Crop Development in Cotton

The partitioning of light is very difficult to assess, especially in discontinuous or irregular canopies. The aim of the present study was to analyze the spatial distribution of photosynthetically active radiation (PAR) in a heterogeneous cotton canopy based on a geo-statistical sampling method. Field experiments were conducted in 2011 and 2012 in Anyang, Henan, China. Field plots were arranged in a randomized block design with the main plot factor representing the plant density. There were 3 replications and 6 densities used in every replicate. The six plant density treatments were 15,000, 33,000, 51,000, 69,000, 87,000 and 105,000 plants ha⁻¹. The following results were observed: 1) transmission within the canopy decreased with increasing density and significantly decreased from the top to the bottom of the canopy, but the greatest decreases were observed in the middle layers of the canopy on the vertical axis and closing to the rows along the horizontal axis; 2) the transmitted PAR (TPAR) of 6 different cotton populations decreased slowly and then increased slightly as the leaves matured, the TPAR values were approximately 52.6–84.9% (2011) and 42.7–78.8% (2012) during the early cotton developmental stage, and were 33.9–60.0% (2011) and 34.5–61.8% (2012) during the flowering stage; 3) the Leaf area index (LAI) was highly significant exponentially correlated (R² = 0.90 in 2011, R² = 0.91 in 2012) with the intercepted PAR (IPAR) within the canopy; 4) and a highly significant linear correlation (R² = 0.92 in 2011, R² = 0.96 in 2012) was observed between the accumulated IPAR and the biomass. Our findings will aid researchers to improve radiation-use efficiency by optimizing the ideotype for cotton canopy architecture based on light spatial distribution characteristics.     

Efficacy and Safety of Crizotinib among Chinese EML4-ALK-Positive,Advanced-Stage Non-Small Cell Lung Cancer Patients

Introduction

We report the efficacy and safety of crizotinib treatment among Chinese patients with advanced-stage NSCLC.

Methods

We retrospectively analyzed patients with EML4-ALK positive advanced NSCLC who were treated with crizotinib from May 2012 to Aug 2013. Baseline clinical parameters, treatment protocol, response to therapy and survival were noted. The primary goal was to evaluate the efficacy of crizotinib in patients who were previously treated patients or who had poor ECOG performance status (PS).

Results

Forty patients were evaluable for safety and efficacy. Median age was 43 years, 100% had adenocarcinoma and stage IV disease, and 42.5% were female. Six patients received frontline treatment with crizotinib, 17 patients had 1 prior treatment, and 17 patients had more than 2 lines of prior treatment. Patients received a median of 5 cycles of treatment (range 1–15 cycles). After the first cycle, 92.5% (37/40) patients archived partial remission (PR). At the end of the follow-up period, the overall PR rate was 70% (28/40), and progression of disease (PD) occurred in 30% of patients (12/40). The median PFS was 28 weeks (95% CI 15.4 to 40.5 weeks), and median OS was 40 weeks (95% CI 38.6 to 49.3 weeks). The most frequent treatment-related AEs were vomiting (47.5%), vision disorder (27.5%) and increased ALT/AST (42%); most toxicities were Grade 1/2. Observed treatment-related Grade 3/4 AEs included increased ALT/AST (10%) and vomiting (5%). The EML4-ALK fusion rate and number of prior chemotherapy cycles did not appear to significantly affect the efficacy of crizotinib. However, PS 0–2 patients had improved PFS (50 weeks vs. 24 weeks, p = 0.015).

Conclusions

Crizotinib was safe, well-tolerated, and effective in Chinese patients with pre-treated ALK-rearranged NSCLC. QOL was improved and PS appears to have an effect on the efficacy of crizotinib, but prior treatment and ALK fusion rate do not.     

The cumulative effects of polymorphisms in the DNA mismatch repair genes and tobacco smoking in oesophageal cancer risk

The DNA mismatch repair (MMR) enzymes repair errors in DNA that occur during normal DNA metabolism or are induced by certain cancer-contributing exposures. We assessed the association between 10 single-nucleotide polymorphisms (SNPs) in 5 MMR genes and oesophageal cancer risk in South Africans. Prior to genotyping, SNPs were selected from the HapMap database, based on their significantly different genotypic distributions between European ancestry populations and four HapMap populations of African origin. In the Mixed Ancestry group, the MSH3 rs26279 G/G versus A/A or A/G genotype was positively associated with cancer (OR?=?2.71; 95% CI: 1.34-5.50). Similar associations were observed for PMS1 rs5742938 (GG versus AA or AG: OR?=?1.73; 95% CI: 1.07-2.79) and MLH3 rs28756991 (AA or GA versus GG: OR?=?2.07; 95% IC: 1.04-4.12). In Black individuals, however, no association between MMR polymorhisms and cancer risk was observed in individual SNP analysis. The interactions between MMR genes were evaluated using the model-based multifactor-dimensionality reduction approach, which showed a significant genetic interaction between SNPs in MSH2, MSH3 and PMS1 genes in Black and Mixed Ancestry subjects, respectively. The data also implies that pathogenesis of common polymorphisms in MMR genes is influenced by exposure to tobacco smoke. In conclusion, our findings suggest that common polymorphisms in MMR genes and/or their combined effects might be involved in the aetiology of oesophageal cancer.     

细胞周期调控因子在肺癌活检组织中的表达

目的：探讨P^21waf1和CyclinE在肺鳞癌组织中表达,方法：应用细胞周期调控因子P^21waf1、CyclinE单克隆抗体,对54例肺鳞状细胞的纤支镜活检标本和10例正常肺组织进行免疫组化染色研究。结果：在肺鳞癌组织中P^21waf1呈低水平表达,其阳性表达率（11／54）仅为20．4％,在肺鳞癌组织中CyclinE阳性表达率（17／54）为31．5％,低分化及有淋巴结转移的病例,其CyclinE表达量明显高于高中分化及无淋巴结转移的病例。结论：P^21waf1在肺鳞癌组织中呈低表达,CyclinE表达可以作为判断肺鳞癌恶性程度的一个指标。     

A new point mutation in the iron–sulfur subunit of succinate dehydrogenase confers resistance to boscalid in Sclerotinia sclerotiorum

Research has established that mutations in highly conserved amino acids of the succinate dehydrogenase (SDH) complex in various fungi confer SDH inhibitor (SDHI) resistance. For Sclerotinia sclerotiorum (Lib.) de Bary, a necrotrophic fungus with a broad host range and a worldwide distribution, boscalid resistance has been attributed to the mutation H132R in the highly conserved SdhD subunit protein of the SDH complex. In our previous study, however, only one point mutation, A11V in SdhB (GCA to GTA change in SdhB), was detected in S. sclerotiorum boscalid‐resistant (BR) mutants. In the current study, replacement of the SdhB gene in a boscalid‐sensitive (BS) S. sclerotiorum strain with the mutant SdhB gene conferred resistance. Compared with wild‐type strains, BR and GSM (SdhB gene in the wild‐type strain replaced by the mutant SdhB gene) mutants were more sensitive to osmotic stress, lacked the ability to produce sclerotia and exhibited lower expression of the pac1 gene. Importantly, the point mutation was not located in the highly conserved sequence of the iron–sulfur subunit of SDH. These results suggest that resistance based on non‐conserved vs. conserved protein domains differs in mechanism. In addition to increasing our understanding of boscalid resistance in S. sclerotiorum, the new information will be useful for the development of alternative antifungal drugs.     

长期连作农田土壤细菌群落结构和共现网络拓扑性质对土壤理化性质的响应

【目的】为探究长期连作土壤细菌群落结构和分子生态网络与土壤环境演化的关联性。【方法】本研究利用16S rRNA基因高通量测序技术,解析了湖南省浏阳市两块连作十二年农田(表现连作障碍的GD和健康的YA)土壤微生物群落组成结构和分子生态网络拓扑性质与土壤理化性质的关系。【结果】GD土壤总氮和有效磷含量显著高于YA,而土壤硝态氮和速效钾含量显著低于YA(P<0.05)。GD土壤细菌群落多样性高于YA,两地土壤细菌群落结构存在显著差异(P<0.01),且与土壤pH和有效磷含量相关。进一步分析表明,GD土壤细菌群落之间比YA具有更复杂的生态网络,主要体现在能量代谢、碳循环和氮循环功能模块。【结论】综上所述,连作会引起土壤细菌群落多样性、组成结构和生态网络变化,这可能与土壤理化性质恶化、土壤肥力下降密切相关,进而影响作物生长发育。     

Improved SnO2 Electron Transport Layers Solution‐Deposited at Near Room Temperature for Rigid or Flexible Perovskite Solar Cells with High Efficiencies

Electron transport layer (ETL) is a functional layer of great significance for boosting the power conversion efficiency (PCE) of perovskite solar cells (PSCs). To date, it is still a challenge to simultaneously reduce the surface defects and improve the crystallinity in ETLs during their low‐temperature processing. Here, a novel strategy for the mediation of in situ regrowth of SnO₂ nanocrystal ETLs is reported: introduction of controlled trace amounts of surface absorbed water on the fluorinated tin oxide (FTO) or indium–tin oxide (ITO) surfaces of the substrates using ultraviolet ozone (UVO) pretreatment. The optimum amount of adsorbed water plays a key role in balancing the hydrolysis–condensation reactions during the structural evolution of SnO₂ thin films. This new approach results in a full‐coverage SnO₂ ETL with a desirable morphology and crystallinity for superior optical and electrical properties, as compared to the control SnO₂ ETL without the UVO pretreatment. Finally, the rigid and flexible PSC devices based on the new SnO₂ ETLs yield high PCEs of up to 20.5% and 17.5%, respectively.