Inhibition of Autophagy Potentiated the Antitumor Effect of Nedaplatin in Cisplatin-Resistant Nasopharyngeal Carcinoma Cells

Nedaplatin, a cisplatin analog, was developed to reduce the toxicity of cisplatin, whereas it can be cross-resistant with cisplatin in some circumstances. This study aimed to investigate the role of autophagy in nedaplatin induced cell death in cisplatin-resistant nasopharyngeal carcinoma cells. Here, we showed that HNE1/DDP and CNE2/DDP cells were resistant to nedaplatin-induced cell death with reduced apoptotic activity. Nedaplatin treatment resulted in autophagosome accumulation and increased expression of LC3-II, indicating the induction of autophagy by nedaplatin in HNE1/DDP and CNE2/DDP cells. Inhibition of autophagy by Bafilomycin A1 (Baf A1) and 3-Methyladenine (3-MA) remarkably enhanced the antitumor efficacy of nedaplatin in HNE1/DDP and CNE2/DDP cells, suggesting that the resistance to nedaplatin-induced cell death was caused by enhanced autophagy in nedaplatin-resistant NPC cells. Additionally, Baf A1 enhanced reactive oxygen species (ROS) generation and apoptosis induced by nedaplatin in HNE1/DDP cells. Mechanistically, nedaplatin treatment caused activation of ERK1/2 and suppression of Akt/mTOR signaling pathways. While inhibition of ERK1/2 by MEK1/2 inhibitor, U0126, could reduce the expression of LC3-II in nedaplatin-resistant NPC cells. Furthermore, suppression of ROS could inhibit nedaplatin-induced ERK activation in HNE1/DDP cells, indicating that ROS and ERK were involved in nedaplatin-induced autophagy. Together, these findings suggested that autophagy played a cytoprotective role in nedaplatin-induced cytotoxicity of HNE1/DDP and CNE2/DDP cells. Furthermore, our results highlighted a potential approach to restore the sensitivity of cisplatin-resistant nasopharyngeal cancer cells to nedaplatin in combination with autophagy inhibitors.     

点突变对高加索乳杆菌醇脱氢酶酶活的影响

从高加索乳杆菌基因组中克隆醇脱氢酶基因,构建重组表达菌后发现不同转化子具有不同的活性,测序结果表明在部分位点发生了点突变.结合生物信息学知识通过对醇脱氢酶结构与作用机理分析,认为在酶关键位点的变变对酶的活性影响较大,而非关键位点的突变对酶活的影响虽明显降低,但其突变的数目可能对酶活的影响呈现一定的累加效应.其中活性最高的重组菌表达了一个可将苯乙酮高选择对映还原成(S)-笨乙醇的醇脱氢酶,该研究结果为酶的定向进化研究提供了理论依据.     

Three main genetic regions for grain development revealed through QTL detection and meta-analysis in maize

Grain weight is one of the three direct yield components, being developed through a dynamic process of grain filling in maize. In this study, 258 recombinant inbred lines derived from a cross between a dent corn and a popcorn inbred were evaluated for grain fresh and dry weight at 10, 20, 30, and 40?days after pollination (DAP) and the activities of ADP-Glc pyrophosphorylase (AGPP), granule-bound starch synthase (GBSS), and soluble starch synthase (SSS) at 30 DAP. Grain-filling rate (GFR) and increasing rate of fresh weight (FWIR) were calculated during all periods. Quantitative trait locus (QTL) mapping was conducted for all traits. Meta-QTL (mQTL) was revealed by meta-analysis using BioMercator. Totally, 161 QTL were detected for six traits. QTL on chromosomes 1, 7, and 10 were detected in most cases, with 43, 54, and 28 QTL, respectively. For each trait, 1?C4 QTL were detected but no QTL for GBSS. Three mQTL at bins 7.02?C7.03, 1.03?C1.04, and 10.05?C10.06 included 47, 24, and 23 QTL detected in this study. Together with 28 QTL for grain weight detected in our previous research, they included 53, 28, and 25 QTL, respectively. Five identified expressed sequence tags (EST), five candidate genes with related functions, and QTL for grain weight in other research were co-located in these regions. It is worth concentrating further research on these regions to develop near-isogenic lines (NILs) of common QTL and their chromosome segment substitution lines (CSSL). Also, cloning and function validation for co-located EST and candidate genes could facilitate identification of genes for grain development and final weight.     

应用糖皮质激素进行鼻腔冲洗对慢性鼻窦炎患者鼻腔菌群多样性和生物膜的影响

目的 分析应用糖皮质激素进行鼻腔冲洗对慢性鼻窦炎(CRS)患者鼻腔菌群多样性及生物膜的影响。 方法 将2018年1月至2018年6月于我院治疗的40例慢性鼻窦炎患者随机分成两组,每组各20例,一组给予0.9%氯化钠注射液进行鼻腔冲洗(NS组),另一组给予0.9%氯化钠注射液及布地奈德进行鼻腔冲洗(NS+BUD组),对两组患者治疗前后的菌群结构差异、多样性及细菌生物膜生成情况进行比较。 结果 治疗前两组患者菌群多样性指标(Chao1指数、Ace指数、Simpson指数及Shannon指数)比较,差异均无统计学意义(均P>0.05),治疗后两组患者的Chao1指数、Ace指数及Shannon指数均明显下降(均P结论 应用糖皮质激素对慢性鼻窦炎患者进行鼻腔冲洗可降低患者鼻腔微生物多样性,减少菌群的异常增殖,降低主要致病菌的生物膜表达,提高临床疗效。     

Effects of Shading on the Senescence and Photosynthetic Physiology of the Early-Flowering Rice Mutant FTL10 at Noon

FTL10 is an early-flowering mutant of rice (Oryza sativa L.) with a premature senescent phenotype. Early leaf senescence can cause negative effects on rice yield. Moreover, rice leaves are damaged under high-light conditions, which promote rice senescence. Artificial shading can reduce the amount of light absorbed by rice leaves. The aim of this study was to investigate the effects of shading at noon (11:30–14:00) on the senescence and yield of FTL10. The results showed that shading improved the total antioxidant capacity of rice leaves, reduced the accumulation of reactive oxygen species (ROS) and reduced the expression of genes related to senescence. In the shaded group, the degradation rate of chlorophyll and Rubisco proteins, which are related to photosynthesis, was relatively slow, and the photosynthetic rate was relatively high. Compared with those under the natural growth conditions, the proportion of photosynthetic electron allocated to photorespiration in the shaded group rice leaves was lower, and the proportion allocated to carbon fixation was higher. The yield data showed that the single-spike weight and yield per plant of rice significantly increased after shading. Therefore, our research shows that shading at noon could delay FTL10 senescence and increase yields.

     

Detection and integration of quantitative trait loci for grain yield components and oil content in two connected recombinant inbred line populations of high-oil maize

Improvement in grain yield is an important objective in high-oil maize breeding. In this study, one high-oil maize inbred was crossed with two normal maize inbreds to produce two connected recombinant inbred line (RIL) populations with 282 and 263 F_7:8 families, respectively. The field experiments were conducted under four environments, and eight grain yield components and grain oil content were evaluated. Two genetic linkage maps were constructed using 216 and 208 polymorphic SSR markers. Quantitative trait loci (QTL) were detected for all traits under each environment and in combined analysis. Meta-analysis was used to integrate genetic maps and detected QTL in both populations. A total of 199 QTL were detected, 122 in population 1 and 87 in population 2. Seven, 11 and 19 QTL showed consistency across five environments, across two RIL populations and with respective F_2:3 generations, respectively. 183 QTL were integrated in 28 meta-QTL (mQTL). QTL with contributions over 15% were consistently detected in 3–4 cases and integrated in mQTL. Each mQTL included 3–19 QTL related to 1–4 traits, reflecting remarkable QTL co-location for grain yield components and oil content. Further research and marker-assisted selection (MAS) should be concentrated on 37 consistent QTL and four genetic regions of mQTL with more than 10 QTL at bins 3.04–3.05, 7.02, 8.04–8.05 and 9.04–9.05. Near-isogenic lines for 100-grain-weight QTL at bin 7.02–7.03, for ear-length QTL at bin 7.02–7.03 and for rows-per-ear QTL at bin 3.08 are now in construction using MAS. Co-located candidate genes could facilitate the identification of candidate genes for grain yield in maize.     

Anthocyanin accumulation in juvenile Schima superba leaves is a growth trade-off by consuming energy for adaptation to high light during summer

AimsAnthocyanin accumulation is the main factor underlying why young plant leaves turn red, and plant growth follows the principle of maximizing the economic efficiency of energy. There is a need to verify the role of young plant leaves turning red and confirm whether anthocyanin accumulation overconsumes the energy of the plant.