Sevoflurane Postconditioning Attenuates Hepatic Ischemia-Reperfusion Injury by Limiting HMGB1/TLR4/NF-κB Pathway via Modulating microRNA-142 in vivo and in vitro

Preconditioning of sevoflurane (Sevo) has been demonstrated to protect the liver from ischemia/reperfusion (I/R) injury. However, it is unknown whether it has hepatoprotective when given at the onset of reperfusion (postconditioning), a protocol with more clinical impact. The present study aimed to explore the hepatoprotective effects of Sevo postconditioning against hepatic IR injury in vivo and in vitro and the possible mechanisms. Using a mouse model of hepatic I/R, Sevo postconditioning significantly improved hepatic injury after reperfusion, as demonstrated by reduced AST, ALT, and LDH serum levels and reduced histologic damage in liver tissues. Furthermore, Sevo postconditioning could suppress the apoptosis, inhibit oxidative stress and inflammatory response in liver tissue of HIRI mice, as well as improve the survival rate of HIRI mice. Through analyzing GSE72314 from the gene expression omnibus (GEO) database, it was demonstrated that microRNA (miR)-142 is downregulated by HIRI, which was reversed by Sevo treatment. Further investigation showed that agomiR-142 injection could enhance the hepatoprotective effects of Sevo postconditioning on I/R injury, while antagomiR-142 reversed these effects in mice. Notably, high mobility group box 1 (HMGB1), an important inflammatory factor, was directly targeted by miR-142 in hepatic cells, and we further found that Sevo could inhibit the expression of HMGB1 through up-regulating miR-142 expression in HIRI mice model. In addition, we found that I/R injury induced the activation of TLR4/NF-κB inflammatory pathway was partially suppressed by Sevo postconditioning, and miR-142 mediated the regulatory role of Sevo postconditioning. In line with the in vivo results, Sevo treatment improved the cell viability, inhibited cell apoptosis, oxidative stress and inflammatory response in vitro HIRI model, while these effects were reversed by antagomiR-142 transfection. Collectively, our findings demonstrated that Sevo postconditioning counteracts the downregulation of miR-142 provoked by I/R, in turn decreased the expression of HMGB1, blocking TLR4/NF-κB pathway activation, thus improving hepatic I/R injury. Our data suggest that Sevo may be a valuable alternative anaesthetic agent in liver transplantation and major liver surgeries.

Unique Profile of Driver Gene Mutations in Patients With Non-Small-Cell Lung Cancer in Qujing City, Yunnan Province, Southwest China

Objective

Qujing City, Yunnan Province, China, has a high incidence of lung cancer and related mortality. The etiology of NSCLC in Qujing area and distribution of associated molecular aberrations has not been fully elucidated. This study aimed to reveal the profile of driver gene mutations in patients with non-small-cell lung cancer (NSCLC) in Qujing and explore their relationships with clinicopathological characteristics.

Methods

In this study, the mutation profiles of NSCLC driver genes, including EGFR, ALK, ROS1, KRAS, BRAF, RET, MET, HER2, NRAS, and PIK3CA, were investigated in patients with NSCLC from Qujing and compared with those from other regions in Yunnan Province. The associations between molecular mutations and clinicopathological characteristics were further analyzed.

Results

A distinct profile of driver gene mutations was discovered in patients with NSCLC from Qujing. Interestingly, a higher proportion of EGFR compound mutations, including G719X + S768I (19.65% vs 3.38%, P < 0.0001) and G719X + L861Q (21.10% vs 2.82%, P < 0.0001), was observed in patients with NSCLC in Qujing compared with patients in non-Qujing area, besides significantly different distributions of EGFR (46.01% vs. 51.07%, P = 0.0125), ALK (3.17% vs. 6.97%, P = 0.0012), ROS1 (0.5% vs. 2.02%, P = 0.0113), and KRAS (23.02% vs. 7.85%, P < 0.0001). Further, EGFR compound mutations were more likely associated with the occupation of patients (living/working in rural areas, e.g., farmers). Moreover, KRAS G12C was the dominant subtype (51.11% vs 25.00%, P = 0.0275) among patients with NSCLC having KRAS mutations in Qujing.

Conclusions

Patients with NSCLC in Qujing displayed a unique profile of driver gene mutations, especially a higher prevalence of EGFR compound mutations and dominant KRAS G12C subtype, in this study, indicating a peculiar etiology of NSCLC in Qujing. Therefore, a different paradigm of therapeutic strategy might need to be considered for patients with NSCLC in Qujing.

Flower strips as a bridge habitat facilitate the movement of predatory beetles from wheat to maize crops

BACKGROUND

Generalist predators play a key role in the biocontrol of insect pests in agricultural systems. However, predators are subject to frequent mortality events due to periodic disturbance regimes such as crop planting and harvest, which inevitably affect the population development of predators. Conservation of predators in this critical period is important for double-cropping systems such as winter wheat and summer maize, the most widely used cropping system in North China.

RESULTS

Planting Cnidium monnieri flower strips at field borders could not only serve as a bridge habitat to conserve the dominant predator Propylaea japonica in wheat fields during harvest but also help the predator immigrate to adjacent maize fields. The predator abundance was 7-fold higher on flower strips than that on natural vegetation strips during the wheat postharvest period and before the maize plant emergence for about a month, and its abundance in maize fields planted with flower strips was nearly 2-fold higher than that in maize fields planted with natural vegetation strips. Moreover, 77.56% of predators that entered maize fields were proven to originate from flower strips.

CONCLUSION

Our findings provided evidence that manipulating flower strips as a bridge habitat in wheat-maize rotation fields could conserve P. japonica during crop phenophase changes, and we quantitatively testified that the proportion of this predator in maize fields derived from flower strips. In practice, such a strategy may also be applied in other double-cropping and triple-cropping systems. © 2020 Society of Chemical Industry.

RNA Sequencing Analysis of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) Reveals the Mechanism Underlying Insecticide Resistance

Xinjiang (XJ) and Ningxia (NX) provinces are important agricultural regions in western China. Aphids are one kind of the most devastating pests in both the provinces. Aphids are typical phloem-feeding insects distributed worldwide and can severely damage crops. In this study, two representative Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) populations were collected from the typical agricultural regions of XJ and NX, respectively for a high-throughput transcriptome sequencing analysis. A total of 5,265 differentially expressed genes (DEGs) were identified. The functional annotation of DEGs and the identification of enriched pathways indicated many of the DEGs are involved in processes related to energy metabolism, development, and insecticide resistance. Furthermore, an investigation of insecticide toxicity revealed the NX population is more resistant to insecticide treatments than the XJ population. Thus, the transcriptome data generated in present study can be used for functional gene characterization relevant to aphid development, metabolism, environmental adaptation, and insecticide resistance.

Visualizing Diffusional Dynamics of Gold Nanorods on Cell Membrane using Single Nanoparticle Darkfield Microscopy

Analyzing the diffusional dynamics of nanoparticles on cell membrane plays a significant role in better understanding the cellular uptake process and provides a theoretical basis for the rational design of nano-medicine delivery. Single particle tracking (SPT) analysis could probe the position and orientation of individual nanoparticles on cell membrane, and reveal their translational and rotational states. Here, we show how to use traditional dark-field microscopy to monitor the dynamics of gold nanorods (AuNRs) on live cell membrane. We also show how to extract the location and orientation of AuNRs using ImageJ and MATLAB, and how to characterize the diffusive states of AuNRs. Statistical analysis of hundreds of particles show that single AuNRs perform Brownian motion on the surface of U87 MG cell membrane. However, individual long trajectory analysis shows that AuNRs have two distinctly different types of motion states on the membrane, namely long-range transport and limited-area confinement. Our SPT methods can be potentially used to study the surface or intracellular particle diffusion in different biological cells and can become a powerful tool for investigations of complex cellular mechanisms.

[Synergistic effect on biosynthesis of Panax notoginseng saponins by overexpressing a transcription factor PnbHLH and RNA interference of cycloartenol synthase gene]

This study cloned the transcription factor gene PnbHLH which held an open reading frame of 966 bp encoding 321 amino acids. This study constructed the overexpression vector of transcription factor PnbHLH of Panax notoginseng. The combination of PnbHLH overexpression and RNAi of the key enzyme gene PnCAS involved in the phytosterol biosynthesis was achieved in P. notoginseng cells, thus exploring the biosynthetic regulation of P. notoginseng saponins(PNS) by the synergistic effect of PnbHLH overexpression and PnCAS RNAi. The results showed that the PnbHLH transcription factor interacted with the promoters of key enzyme genes PnDS, PnSS and PnSE in the biosynthetic pathway of PNS, and then regulated the expression levels of key enzyme genes and affected the biosynthesis of saponins indirectly. Further study indicated that the synergistic effect of PnbHLH overexpression and PnCAS RNAi was a more effective approach to regulate the biosynthesis of saponins. Compared with the wild type and PnCAS RNAi cells of P. notoginseng, the contents of total saponins and monomeric saponins(Rd, Rb_1, Re, Rg_1 and R_1) were increased to some extent in the cell lines of PnbHLH overexpression and PnCAS RNAi. This indicated that the two ways of forward regulation and reverse regulation of saponin biosynthesis showed superposition effect. This study explored a more rational and efficient regulation strategy of PNS biosynthesis based on the advantages of multi-point regulation of transcription factors as well as the down-regulation of by-product synthesis of saponins.

Moderately decreasing fertilizer in fields does not reduce populations of cereal aphids but maximizes fitness of parasitoids

Examination of the tradeoff between the extent of decreasing nitrogen input and pest suppression is crucial for maintaining the balance between essential yield and an efficient, sustainable pest control strategy. In this study, an experiment with four manipulated nitrogen fertilizer levels (70, 140, 210, and 280 kg N ha⁻¹ = conventional level) was conducted to explore the effects of decreasing nitrogen on cereal aphids (Sitobion avenae and Rhopalosiphum padi) (Hemiptera: Aphididae), Aphidiinae parasitoids (Hymenoptera: Braconidae: Aphidiinae), and body sizes of parasitoids. The results indicated that nitrogen application, in the range of 70–280 kg N ha⁻¹, has the potential to impact the populations of cereal aphids and their parasitoids. However, both differences between densities of cereal aphids and their parasitoids in moderate (140–210 kg N ha⁻¹) and those in high nitrogen input (280 kg N ha⁻¹) were not significant, and the parasitism rate was also unaffected. A higher parasitism rate reduced population growth of the cereal aphid (S. avenae). Additionally, a moderate decrease of nitrogen fertilizer from 280 to 140–210 kg N ha⁻¹ maximized the body sizes of Aphidiinae parasitoids, indicating that a moderate decrease of nitrogen fertilizer could facilitate biocontrol of cereal aphid by parasitoids in the near future. We conclude that a moderate decrease in nitrogen application, from 280 to 140–210 kg N ha⁻¹, does not quantitatively impact the densities of cereal aphids or the parasitism rate but can qualitatively maximize the fitness of the parasitoids.

Osteoporotic vertebral fracture misdiagnosed as "normal postoperative phenomenon" in post decompression surgery: a case report

BACKGROUND

Previous research and published literature indicate that some patients with spinal diseases who underwent percutaneous transforaminal endoscopic decompression (PTED) still suffer some discomfort in the early recovery stage in the form of pain, stiffness, and swelling. These are usually considered minor residual symptoms or normal postoperative phenomenon (NPF) in the clinic, occur frequently, and are acknowledged by surgeons worldwide. To the best of our knowledge, we report the first case of a patient who had an osteoporotic vertebral fracture (OVF) misdiagnosed as NPF after she underwent PTED as a result of lumbar disc herniation (LDH).

CASE PRESENTATION

A 71-year-old female with Parkinson's disease who presented with lower back pain radiating to the legs was diagnosed as LDH in L4-5, after which a PTED of L4-5 was performed, with temporary alleviation of symptoms. However, severe lower back pain recurred. Unfortunately, the recurred pain initially misdiagnosed as NPF, in fact, was finally confirmed to be OVF by CT-scan. OVF in the early stage of post-PTED seldom occurs and is rarely reported in the literature. With a percutaneous vertebroplasty, the pain was significantly relieved, and she resumed walking. After 36-weeks of follow-up, the pain improved satisfactorily.

CONCLUSION

Doctors should not immediately diagnose a relapse of back pain following PTED as NPF, and hands-on careful physical and imaging examinations are necessary to manage recurring pain rightly and timely.

A novel phosphoinositide kinase Fab1 regulates biosynthesis of pathogenic aflatoxin in Aspergillus flavus

Aspergillus flavus (A. flavus) is one of the most important model environmental fungi which can produce a potent toxin and carcinogen known as aflatoxin. Aflatoxin contamination causes massive agricultural economic loss and a critical human health issue each year. Although a functional vacuole has been highlighted for its fundamental importance in fungal virulence, the molecular mechanisms of the vacuole in regulating the virulence of A. flavus remain largely unknown. Here, we identified a novel vacuole-related protein in A. flavus, the ortholog of phosphatidylinositol-3-phosphate-5-kinase (Fab1) in Saccharomyces cerevisiae. This kinase was located at the vacuolar membrane, and loss of fab1 function was found to affect the growth, conidia and sclerotial development, cellular acidification and metal ion homeostasis, aflatoxin production and pathogenicity of A. flavus. Further functional analysis revealed that Fab1 was required to maintain the vacuole size and cell morphology. Additional quantitative proteomic analysis suggested that Fab1 was likely to play an important role in maintaining vacuolar/cellular homeostasis, with vacuolar dysregulation upon fab1 deletion leading to impaired aflatoxin synthesis in this fungus. Together, these results provide insight into the molecular mechanisms by which this pathogen produces aflatoxin and mediates its pathogenicity, and may facilitate dissection of the vacuole-mediated regulatory network in A. flavus.

Elevated Carbon Dioxide Levels Decreases Cucumber Mosaic Virus Accumulation in Correlation with Greater Accumulation of rgs-CaM, an Inhibitor of a Viral Suppressor of RNAi

Plant viruses cause a range of plant diseases symptoms that are often responsible for significant crop production losses and the severity and spread of the symptoms may be affected by climate change. While the increase in anthropogenic activities has caused a critical problem of increased CO2 levels in the atmosphere, these elevated CO2 levels have been reported to reduce virus disease severity in some plant species. In such instances, it is not clear if the plant defense mechanisms are being enhanced or virus-mediated mechanisms to overcome plant resistance are being defeated. Additionally, a few studies have been attempted in this area to determine if reduced disease is the norm or the exception under enhanced CO2 levels. In the present study, the effects of elevated CO2 levels (750 ppm vs. 390 ppm) on RNAi-mediated resistance of Nicotiana tabacum against the cucumber mosaic virus (CMV), and the activity of viral suppressor of RNAi (VSR) 2b protein of CMV were evaluated. On the one hand, our results showed that elevated CO2 decreased the transcription of dicer-like protein 2 (DCL2), DCL4, and argonaut 1 (AGO1) genes with functions related to RNAi-mediated resistance when infected by CMV, which is contradictory with the decreased CMV copy numbers under elevated CO2. On the other hand, we found that elevated CO2 increased the calcium concentration and expression of the calcium-binding protein rgs-CaM in tobacco plants when infected by CMV, which directly weakened the function of 2b protein, the VSR of CMV, and therefore decreased the infection efficiency of the virus and suppressed the severity of CMV in tobacco plants under elevated CO2. This study provides molecular insights into the ecological implications underlying the development of prevention strategies against plant virus infection in the context of climate change.

An Aphid-Secreted Salivary Protease Activates Plant Defense in Phloem

Recent studies have reported that aphids facilitate their colonization of host plants by secreting salivary proteins into host tissues during their initial probing and feeding. Some of these salivary proteins elicit plant defenses, but the molecular and biochemical mechanisms that underlie the activation of phloem-localized resistance remain poorly understood. The aphid Myzus persicae, which is a generalized phloem-sucking pest, encompasses a number of lineages that are associated with and adapted to specific host plant species. The current study found that a cysteine protease Cathepsin B3 (CathB3), and the associated gene CathB3, was upregulated in the salivary glands and saliva of aphids from a non-tobacco-adapted (NTA) aphid lineage, when compared to those of a tobacco-adapted lineage. Furthermore, the knockdown of CathB3 improved the performance of NTA lineages on tobacco, and the propeptide domain of CathB3 was found to bind to tobacco cytoplasmic kinase ENHANCED DISEASE RESISTANCE 1-like (EDR1-like), which triggers the accumulation of reactive oxygen species in tobacco phloem, thereby suppressing both phloem feeding and colonization by NTA lineages. These findings reveal a novel function for a cathepsin-type protease in aphid saliva that elicits effective host plant defenses and warranted the theory of host specialization for generalist aphids.

Proteogenomic Characterization of the Pathogenic Fungus Aspergillus flavus Reveals Novel Genes Involved in Aflatoxin Production

Aspergillus flavus (A. flavus), a pathogenic fungus, can produce carcinogenic and toxic aflatoxins that are a serious agricultural and medical threat worldwide. Attempts to decipher the aflatoxin biosynthetic pathway have been hampered by the lack of a high-quality genome annotation for A. flavus. To address this gap, we performed a comprehensive proteogenomic analysis using high-accuracy mass spectrometry data for this pathogen. The resulting high-quality data set confirmed the translation of 8724 previously predicted genes and identified 732 novel proteins, 269 splice variants, 447 single amino acid variants, 188 revised genes. A subset of novel proteins was experimentally validated by RT-PCR and synthetic peptides. Further functional annotation suggested that a number of the identified novel proteins may play roles in aflatoxin biosynthesis and stress responses in A. flavus. This comprehensive strategy also identified a wide range of posttranslational modifications (PTMs), including 3461 modification sites from 1765 proteins. Functional analysis suggested the involvement of these modified proteins in the regulation of cellular metabolic and aflatoxin biosynthetic pathways. Together, we provided a high-quality annotation of A. flavus genome and revealed novel insights into the mechanisms of aflatoxin production and pathogenicity in this pathogen.

Characterization of Lysine Monomethylome and Methyltransferase in Model Cyanobacterium Synechocystis sp. PCC 6803

Protein lysine methylation is a prevalent post-translational modification (PTM) and plays critical roles in all domains of life. However, its extent and function in photosynthetic organisms are still largely unknown. Cyanobacteria are a large group of prokaryotes that carry out oxygenic photosynthesis and are applied extensively in studies of photosynthetic mechanisms and environmental adaptation. Here we integrated propionylation of monomethylated proteins, enrichment of the modified peptides, and mass spectrometry (MS) analysis to identify monomethylated proteins in Synechocystis sp. PCC 6803 (Synechocystis). Overall, we identified 376 monomethylation sites in 270 proteins, with numerous monomethylated proteins participating in photosynthesis and carbon metabolism. We subsequently demonstrated that CpcM, a previously identified asparagine methyltransferase in Synechocystis, could catalyze lysine monomethylation of the potential aspartate aminotransferase Sll0480 both in vivo and in vitro and regulate the enzyme activity of Sll0480. The loss of CpcM led to decreases in the maximum quantum yield in primary photosystem II (PSII) and the efficiency of energy transfer during the photosynthetic reaction in Synechocystis. We report the first lysine monomethylome in a photosynthetic organism and present a critical database for functional analyses of monomethylation in cyanobacteria. The large number of monomethylated proteins and the identification of CpcM as the lysine methyltransferase in cyanobacteria suggest that reversible methylation may influence the metabolic process and photosynthesis in both cyanobacteria and plants.

MiR-124 changes the sensitivity of lung cancer cells to cisplatin through targeting STAT3

OBJECTIVE

To investigate the role of micro ribonucleic acid (miR)-124 in drug resistance of non-small cell lung cancer (NSCLC), and to explore its underlying mechanism.

MATERIALS AND METHODS

The expression levels of miR-124 and signal transducer and activator of transcription 3 (STAT3) in maternal A549 cells and cisplatin-resistant A549/DDP cells were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. A549 and A549/DDP cells were transfected with miR-124 mimics and miR-124 negative control (NC), respectively. Changes in the expression of STAT3 were detected via qRT-PCR and Western blotting. Meanwhile, the sensitivity of cells transfected with miR-124 mimics to cisplatin was detected via methyl thiazolyl tetrazolium (MTT) assay. The effects of miR-124 on the apoptosis, invasion and metastasis of cells were detected via flow cytometry, wound healing assay and transwell assay, respectively. Moreover, wild-type and mutant-type STAT3 luciferase reporter plasmids were co-transfected with miR-124 mimics or miR-124 NC. Luciferase activity was analyzed using the dual-luciferase reporter gene assay.

RESULTS

QRT-PCR and Western blotting revealed that the expression level of miR-124 in A549/DDP cells was significantly lower than that of A549 cells. However, the expression level of STAT3 in A549/DDP cells was significantly higher than that of A549 cells. Overexpression of miR-124 remarkably reduced the expression level of STAT3 in A549/DDP cells, increased the sensitivity of A549/DDP cells to cisplatin, and inhibited the invasion and metastasis capacities of cells. In addition, luciferase reporter gene assay demonstrated that miR-124 could negatively regulate the protein expression of STAT3 by binding to its 3'-untranslated region (UTR).

CONCLUSIONS

MiR-124 regulates the sensitivity of NSCLC to cisplatin. Moreover, it inhibits the invasion and metastasis capacities through targeting STAT3, which can serve as a therapeutic target for cisplatin-based chemotherapy resistance of NSCLC.

Structural and Functional Insights into a Lysine Deacylase in the Cyanobacterium Synechococcus sp. PCC 7002

Lys deacylases are essential regulators of cell biology in many contexts. Here, we have identified CddA (cyanobacterial deacetylase/depropionylase), a Lys deacylase enzyme expressed in the cyanobacterium Synechococcus sp. PCC 7002 that has both deacetylase and depropionylase activity. Loss of the gene cddA led to slower growth and impaired linear and cyclic photosynthetic electron transfer. We determined the crystal structure of this depropionylase/deacetylase at 2.1 Å resolution and established that it has a unique and characteristically folded α/β structure. We detected an acyl binding site within CddA via site-directed mutagenesis and demonstrated that this site is essential for the deproprionylase activity of this enzyme. Through a proteomic approach, we identified a total of 598 Lys residues across 382 proteins that were capable of undergoing propionylation. These propionylated proteins were highly enriched for photosynthetic and metabolic functionality. We additionally demonstrated that CddA was capable of catalyzing in vivo and in vitro Lys depropionylation and deacetylation of Fru-1,6-bisphosphatase, thereby regulating its enzymatic activity. Our identification of a Lys deacylase provides insight into the mechanisms globally regulating photosynthesis and carbon metabolism in cyanobacteria and potentially in other photosynthetic organisms as well.

Mixed receptors of AMPA and NMDA emulated using a 'Polka Dot'-structured two-dimensional conjugated polymer-based artificial synapse

In a biological synapse, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors mediate fast excitatory neurotransmission, whereas N-methyl-d-aspartate (NMDA) receptors trigger an enhanced memory effect; the complementary roles of AMPA and NMDA are essential in short-term plasticity (STP) to enhance memory effect (EME) transition. Herein, we report the design and fabrication of the first two-dimensional (2D) conjugated polymer (CP)-based synaptic transistor. The special design of the 2D CP with nanoscale-segregated 'polka dot'-structured crystalline phases and adjacent amorphous phases emulate the different receptors of NMDA and AMPA on the postsynaptic membrane for the first time. The synergistic effect of mixed receptors distinguishes STP and enhanced memory effect with a critical point, which regulates the threshold level of the enhanced memory effect induction. This effect has not been reported yet. The special structure avoids easy saturation of a single receptor with consecutively increased excitatory postsynaptic current (EPSC) in response to 1200 stimuli. Furthermore, the 2D P3HT synapse successfully emulates activity-dependent synaptic plasticity, such as metaplasticity and homeostatic plasticity, which are advanced forms of plasticity, allowing the self-adaptive ability of a synapse, but have rarely been reported.

An aphid facultative symbiont suppresses plant defence by manipulating aphid gene expression in salivary glands

Aphids often carry facultative symbionts to achieve diverse advantages. Serratia symbiotica, one of facultative endosymbionts, increases aphid tolerance to heat. However, whether it benefits aphid colonization on host plants is yet to be determined. In the current study, we found that Acyrthosiphon pisum harbouring S. symbiotica had longer feeding duration on Medicago truncatula than Serratia-free aphids. Contrastingly, Serratia-free aphids triggered higher accumulation of reactive oxygen species (ROS), jasmonic acid and salicylic acid responsive genes and cytosolic Ca²⁺ elevations than Serratia-infected aphids. Transcriptomic analysis of salivary glands indicated that a histidine-rich Ca²⁺ -binding protein-like gene (ApHRC) was expressed more highly in the salivary gland of Serratia-infected aphids than that of Serratia-free aphids. Once ApHRC was silenced, Serratia-infected aphids also displayed shorter phloem-feeding duration and caused Ca²⁺ elevation and ROS accumulation in plants. Our results suggest that ApHRC, a potential effector up-regulated by S. symbiotica in the salivary glands, impairs plant defence response by suppressing Ca²⁺ elevation and ROS accumulation, allowing colonization of aphids. This study has provided an insight into how facultative symbionts facilitate aphid colonization and adaptation to host plants.

Apoptotic neurodegeneration in whitefly promotes the spread of TYLCV

The mechanism by which plant viruses manipulate the behavior of insect vectors has largely been described as indirect manipulation through modifications of the host plant. However, little is known about the direct interaction of the plant virus on the nervous system of its insect vector, and the substantial behavioral effect on virus transmission. Using a system consisting of a Tomato yellow leaf curl virus (TYLCV) and its insect vector whitefly, we found that TYLCV caused caspase-dependent apoptotic neurodegeneration with severe vacuolar neuropathological lesions in the brain of viruliferous whitefly by inducing a putative inflammatory signaling cascade of innate immunity. The sensory defects caused by neurodegeneration removed the steady preference of whitefly for virus-infected plants, thereby enhancing the probability of the virus to enter uninfected hosts, and eventually benefit TYLCV spread among the plant community. These findings provide a neuromechanism for virus transmission to modify its associated insect vector behavior.

When a plant becomes infected by a virus, its defenses get weakened, which attracts insects that are looking for an easy meal. Insects detect which plants are infected based on the color of the sickened plant and the smell of chemicals it releases. Once an insect leaves the infected plant, it may carry the virus to new plants, allowing the virus to spread.

Insects, however, prefer the easy pickings of plants that are already infected, making them less likely to spread the virus. Plant viruses have found ways to overcome this preference, but how they do this was not fully understood. Learning more about how plant viruses manipulate insects into helping them spread could allow scientists to develop new ways of protecting food crops from viral diseases.

Viruses that infect insects can trigger excessive immune system responses that damage insects’ nerves and cause them to behave differently. For example, their senses may become impaired, they may move less, or be less able to remember things. This has led scientists to wonder whether plant viruses that use insects to spread might manipulate the insects’ behaviors using a similar mechanism.

Now, Wang et al. have investigated whether the tomato yellow leaf curl virus –TYLCV for short – changes the behavior of whiteflies, which are known to spread the virus. The experiments showed that whiteflies typically prefer tomato plants infected with the virus, but after carrying TYLCV, they displayed equal preference for both infected and uninfected plants. Analyzing which genes were active in the whiteflies revealed that TYLCV triggers a harmful immune response which turns on genes that cause cells in the brain to die. This impairs the whiteflies' sight and sense of smell, making it harder for them to distinguish between infected and uninfected plants.

These findings suggest that the immune response triggered by the virus may be essential for the spread of TYLCV. It also identified a protein that causes the death of brain cells, leading to behavioral changes in the whiteflies. This suggests that targeting this protein, or other steps in this process, could help stop the spread of TYLCV in tomato plants.

IL-21 Stimulates the expression and activation of cell cycle regulators and promotes cell proliferation in EBV-positive diffuse large B cell lymphoma

The clinical features of EBV-positive diffuse large B cell lymphoma (DLBCL) indicate a poorer prognosis than EBV-negative DLBCL. Currently, there is no efficacious drug for EBV-positive DLBCL. The cytokine interleukin-21 (IL-21) has been reported to be pro-apoptotic in DLBCL cell lines and is being explored as a new therapeutic strategy for this type of lymphomas. However, our previous studies showed that IL-21 stimulation of EBV-positive DLBCL cell lines leads to increased proliferation. Here, analysis of a rare clinical sample of EBV-positive DLBCL, in combination with a NOD/SCID mouse xenograft model, confirmed the effect of IL-21 on the proliferation of EBV-positive DLBCL cells. Using RNA-sequencing, we identified the pattern of differentially-expressed genes following IL-21 treatment and verified the expression of key genes at the protein level using western blotting. We found that IL-21 upregulates expression of the host MYC and AP-1 (composed of related Jun and Fos family proteins) and STAT3 phosphorylation, as well as expression of the viral LMP-1 protein. These proteins are known to promote the G1/S phase transition to accelerate cell cycle progression. Furthermore, in NOD/SCID mouse xenograft model experiments, we found that IL-21 treatment increases glucose uptake and angiogenesis in EBV-positive DLBCL tumours. Although more samples are needed to validate these observations, our study reconfirms the adverse effects of IL-21 on EBV-positive DLBCL, which has implications for the drug development of DLBCL.

Analysis of risk factors of stage IV gastric cancer from the SEER database

INTRODUCTION

Gastric cancer is the fourth most common cancer in the world. By the time the patients are diagnosed with stage IV gastric cancer, many patients already have distant metastases. There is no unified systemic treatment plan in existence. The use of gastrectomy is ambiguous in patients with stage IV gastric cancer. The objective of this study was to evaluate the beneficial outcome of gastrectomy in patients with stage IV gastric cancer.

METHODS

Clinical information of patients with gastric cancer from 2000 to 2010 in the Surveillance, Epidemiology, and End Results database were extracted and analysed. The risk factors for stage IV gastric cancer were also analysed.

RESULTS

We observed that the median survival time for patients after surgery was greater than that for patients not treated surgically. The five-year survival rate for chemotherapy patients was higher than that of non-chemotherapeutic patients. Patients who receive both chemotherapy and surgery could achieve a more significant survival benefit. The risks following gastrectomy (partial, subtotal, hemi-) were lower than those of other surgical procedures, which provided guidance on the choice of surgical method. The numbers of regional lymph node metastasis were found to be related to prognosis.

CONCLUSIONS

In patients with stage IV gastric cancer, gastrectomy (partial, subtotal or hemi) should be selected when surgery is necessary. The number of regional lymph node metastasis could be considered as a prognostic factor for patients with stage IV gastric cancer and lymph node dissection could reduce the risk of patients undergoing surgery.

Sulfoxaflor Degraded by Aminobacter sp. CGMCC 1.17253 through Hydration Pathway Mediated by Nitrile Hydratase

Sulfoxaflor, a sulfoximine insecticide, could efficiently control many insect pests of sap-feeding. Microbial degradation of sulfoxaflor and the enzymatic mechanism involved have not been studied to date. A bacterial isolate JW2 that transforms sulfoxaflor to X11719474 was isolated and identified as Aminobacter sp. CGMCC 1.17253. Both the recombinant Escherichia coli strain harboring the Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) gene and the pure NHase acquired sulfoxaflor-degrading ability. Aminobacter sp. CGMCC 1.17253 NHase is a typical cobalt-containing NHase content of subunit α, subunit β, and an accessory protein, and the three-dimensional homology model of NHase was built. Substrate specificity tests showed that NHase catalyzed the conversion of acetamiprid, thiacloprid, indolyl-3-acetonitrile, 3-cyanopyridine, and benzonitrile into their corresponding amides, indicating its broad substrate specificity. This is the first report of the pure bacteria degradation of the sulfoxaflor residual in the environment and reveals the enzymatic mechanism mediated by Aminobacter sp. CGMCC 1.17253.

Antioxidant-related catalase CTA1 regulates development, aflatoxin biosynthesis, and virulence in pathogenic fungus Aspergillus flavus

Reactive oxygen species (ROS) induce the synthesis of a myriad of secondary metabolites, including aflatoxins. It raises significant concern as it is a potent environmental contaminant. In Aspergillus flavus., antioxidant enzymes link ROS stress response with coordinated gene regulation of aflatoxin biosynthesis. In this study, we characterized the function of a core component of the antioxidant enzyme catalase (CTA1) of A. flavus. Firstly, we verified the presence of cta1 corresponding protein (CTA1) by Western blot analysis and mass-spectrometry based analysis. Then, the functional study revealed that the growth, sporulation and sclerotia formation significantly increased, while aflatoxins production and virulence were decreased in the cta1 deletion mutant as compared with the WT and complementary strains. Furthermore, the absence of the cta1 gene resulted in a significant rise in the intracellular ROS level, which in turn added to the oxidative stress level of cells. A further quantitative proteomics investigation hinted that in vivo, CTA1 might maintain the ROS level to facilitate the aflatoxin synthesis. All in all, the pleiotropic phenotype of A. flavus CTA1 deletion mutant revealed that the antioxidant system plays a crucial role in fungal development, aflatoxins biosynthesis and virulence.

The circular RNA CDR1as regulate cell proliferation via TMED2 and TMED10

Background

Circular RNAs (CircRNAs) are biologically active RNAs. CDR1as is one such circRNA previously reported to be a microRNA-7 (miR-7) sponge, thereby regulating associated gene expression. The specific underlying molecular mechanisms of CDR1as biology, however, remain largely unknown.

Methods

We performed CDR1as knockdown in order to explore its function in cell proliferation, migration, the cell cycle, and tumorigenesis. We further employed quantitative proteomic analyses and associated bioinformatics strategies to globally assess CDR1as-regulated proteins (CRPs). Western blotting and immunofluorescence staining were used to validate the proteomic results. We additionally investigated a specific link between TMED2, TMED10, and miR-7 via a dual-luciferase reporter system, and generated CDR1as knockout cell lines via CRISPR/Cas9 editing.

Results

We identified 353 proteins dysregulated upon CDR1as knockdown in 293 T cells. These CRPs were found to interact with one another and to play key roles in certain cellular pathways. Two such proteins, TMED2 and TMED10, were found to specifically contribute to the influence of CDR1as on cell proliferation. CDR1as may regulate these two TMED proteins through miR-7 sponging. We were able to further confirm these results using both CRISPRi cell lines and nude mouse models.

Conclusion

This study suggested that CDR1as may regulate cell proliferation via serving as a miR-7 sponge, thereby regulating TMED2 and TMED10 expression. These results are an invaluable template for future streamlined studies of circRNAs.

Ophiocordyceps lanpingensis polysaccharides attenuate pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with growing prevalence. Currently available therapies for treating IPF are not desirable due to the limited efficacy and multiple side effects. Ophiocordyceps lanpingensis is one strain of entomogenous fungi, which has been collected from the eastern part of the Himalayas. This study revealed that O. lanpingensis polysaccharides (OLP) could attenuate bleomycin (BLM) induced lung fibrosis in mice. Results showed that OLP treatments significantly reduced BLM-induced collagen deposition and decreased the accumulation of macrophages. The oxidative stress of the lung was alleviated by OLP. The expression levels of pro-inflammatory and pro-fibrogenic factors in OLP groups were also decreased compared with those in the BLM group, which might explain the improved alveolar integrity and function in the OLP treated groups. Our findings indicated that OLP treatment could alleviate pulmonary fibrosis progression mainly through reducing the recruitment of macrophages to the lungs.