Genome-Wide Identification and Expression Analysis of MAPK Gene Family in Lettuce (Lactuca sativa L.) and Functional Analysis of LsMAPK4 in High- Temperature-Induced Bolting.

The mitogen-activated protein kinase (MAPK) pathway is a widely distributed signaling cascade in eukaryotes and is involved in regulating plant growth, development, and stress responses. High temperature, a frequently occurring environmental stressor, causes premature bolting in lettuce with quality decline and yield loss. However, whether MAPKs play roles in thermally induced bolting remains poorly understood. In this study, 17 LsMAPK family members were identified from the lettuce genome. The physical and chemical properties, subcellular localization, chromosome localization, phylogeny, gene structure, family evolution, cis-acting elements, and phosphorylation sites of the LsMAPK gene family were evaluated via in silico analysis. According to phylogenetic relationships, LsMAPKs can be divided into four groups, A, B, C, and D, which is supported by analyses of gene structure and conserved domains. The collinearity analysis showed that there were 5 collinearity pairs among LsMAPKs, 8 with AtMAPKs, and 13 with SlMAPKs. The predicted cis-acting elements and potential phosphorylation sites were closely associated with hormones, stress resistance, growth, and development. Expression analysis showed that most LsMAPKs respond to high temperatures, among which LsMAPK4 is significantly and continuously upregulated upon heat treatments. Under heat stress, the stem length of the LsMAPK4-knockdown lines was significantly shorter than that of the control plants, and the microscope observations demonstrated that the differentiation time of flower buds at the stem apex was delayed accordingly. Therefore, silencing of LsMAPK4 significantly inhibited the high- temperature-accelerated bolting in lettuce, indicating that LsMPAK4 might be a potential regulator of lettuce bolting. This study provides a theoretical basis for a better understanding of the molecular mechanisms underlying the MAPK genes in high-temperature-induced bolting.

Rapid determination of the total content of oleanolic acid and ursolic acid in Chaenomelis Fructus using near-infrared spectroscopy.

Chaenomelis Fructus is a widely used traditional Chinese medicine with a long history in China. The total content of oleanolic acid (OA) and ursolic acid (UA) is taken as an important quality marker of Chaenomelis Fructus. In this study, quantitative models for the prediction total content of OA and UA in Chaenomelis Fructus were explored based on near-infrared spectroscopy (NIRS). The content of OA and UA in each sample was determined using high-performance liquid chromatography (HPLC), and the data was used as a reference. In the partial least squares (PLS) model, both leave one out cross validation (LOOCV) of the calibration set and external validation of the validation set were used to screen spectrum preprocessing methods, and finally the multiplicative scatter correction (MSC) was chosen as the optimal pretreatment method. The modeling spectrum bands and ranks were optimized using PLS regression, and the characteristic spectrum range was determined as 7,500-4,250 cm-1, with 14 optimal ranks. In the back propagation artificial neural network (BP-ANN) model, the scoring data of 14 ranks obtained from PLS regression analysis were taken as input variables, and the total content of OA and UA reference values were taken as output values. The number of hidden layer nodes of BP-ANN was screened by full-cross validation (Full-CV) of the calibration set and external validation of the validation set. The result shows that both PLS model and PLS-BP-ANN model have strong prediction ability. In order to evaluate and compare the performance and prediction ability of models, the total content of OA and UA in each sample of the test set were detected under the same HPLC conditions, the NIRS data of the test set were input, respectively, to the optimized PLS model and PLS-BP-ANN model. By comparing the root-mean-square error (RMSEP) and determination coefficient (R 2) of the test set and ratio of performance to deviation (RPD), the PLS-BP-ANN model was found to have better performance with RMSEP of 0.59 mg·g-1, R 2 of 95.10%, RPD of 4.53 and bias of 0.0387 mg·g-1. The results indicated that NIRS can be used for the rapid quality control of Chaenomelis Fructus.

New Insights and Experimental Investigation of High-Temperature Gel Reinforced by Nano-SiO2.

The properties of a reinforced gel with partially hydrolyzed polyacrylamide (HPAM) as the main agent, water-soluble phenolic resin (WSPR) as the crosslinker, and nano-SiO2 as the stabilizer were evaluated in terms of gelation time, gel strength and thermal stability under the conditions of 110 °C and 12.124 g/L salinity in water. The results showed that the gelation time of the gel with high strength was adjustable from 3 to 23 h, remaining stable for more than 180 days under stratigraphic conditions, although with a certain degree of early dehydration in the gel. Cryo-scanning electron microscopy (cryo-SEM) and dynamic light scattering (DLS) analysis revealed that nano-SiO2 improves the dispersion of the polymer in water, resulting in a more homogeneous structure of the formed gel and thus improving the strength of the gels. In addition, rheological tests and cryo-SEM showed that the interaction between nano-SiO2 and the polymer could inhibit the degradation of polymer to a certain extent and improve the thermal stability of the gel. However, the oxidative degradation of the gel is still the main cause of early dehydration of water-soluble phenolic resin gel, and the addition of a small amount of hydroquinone to the gelants can significantly improve the antioxidative degradation properties of phenolic resin gel.

Recent Advances in Self-Powered Piezoelectric and Triboelectric Sensors: From Material and Structure Design to Frontier Applications of Artificial Intelligence.

The development of artificial intelligence and the Internet of things has motivated extensive research on self-powered flexible sensors. The conventional sensor must be powered by a battery device, while innovative self-powered sensors can provide power for the sensing device. Self-powered flexible sensors can have higher mobility, wider distribution, and even wireless operation, while solving the problem of the limited life of the battery so that it can be continuously operated and widely utilized. In recent years, the studies on piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs) have mainly concentrated on self-powered flexible sensors. Self-powered flexible sensors based on PENGs and TENGs have been reported as sensing devices in many application fields, such as human health monitoring, environmental monitoring, wearable devices, electronic skin, human-machine interfaces, robots, and intelligent transportation and cities. This review summarizes the development process of the sensor in terms of material design and structural optimization, as well as introduces its frontier applications in related fields. We also look forward to the development prospects and future of self-powered flexible sensors.

Phylogenetic and ion-response analyses reveal a relationship between gene expansion and functional divergence in the Ca2+/cation antiporter family in Angiosperms.

KEY MESSAGE: Plant CaCA superfamily genes with higher tendency to retain after WGD are more gene expression and function differentiated in ion-response. Plants and animals face different environmental stresses but share conserved Ca2+ signaling pathways, such as Ca2+/Cation transport. The Ca2+/cation antiporters superfamily (CaCAs) is an ancient and widespread family of ion-coupled cation transporters found in all kingdoms of life. We analyzed the molecular evolution progress of the family through comparative genomics and phylogenetics of CaCAs genes from plants and animals, grouping these genes into several families and clades, and identified multiple gene duplication retention events, particularly in the CAX (H+/cation exchanger), CCX (cation/Ca2+ exchanger), and NCL (Na+/Ca2+ exchanger-like) families. The tendency of duplication retention differs between families and gene clades. The gene duplication events were probably the result of whole-genome duplication (WGD) in plants and might have led to functional divergence. Tissue and ion-response expression analyses revealed that CaCAs genes with more highly differentiated expression patterns are more likely to be retained as duplicates than those with more conserved expression profiles. Phenotype of Arabidopsis thaliana mutants showed that loss of genes with a greater tendency to be retained after duplication resulted in more severe growth deficiency. CaCAs genes in salt-tolerant species tended to inherit the expression characteristics of their most recent common ancestral genes, with conservative ion-response expression. This study indicates a possible evolutionary scheme for cation transport and illustrates distinct fates and a mechanism for the evolution of gene duplicates. The increased copy numbers of genes and divergences in expression might have contributed to the divergent functions of CaCAs protein, allowing plants to cope with environmental stresses and adapt to a larger number of ecological niches.

A Long Noncoding RNA, Antisense IL-7, Promotes Inflammatory Gene Transcription through Facilitating Histone Acetylation and Switch/Sucrose Nonfermentable Chromatin Remodeling.

Long noncoding RNAs are important regulators of gene expression in innate immune responses. Antisense IL-7 (IL-7-AS) is a newly discovered long noncoding RNA in human and mouse that has been reported to regulate the expression of IL-6. However, the potential function of IL-7-AS in innate immune system is not fully understood. In this study, we found that the expression of IL-7-AS is primarily dependent on the NF-κB and MAPK signaling pathways in macrophages and intestinal epithelial cells. Functionally, IL-7-AS promotes the expression of several inflammatory genes, including CCL2, CCL5, CCL7, and IL-6, in cells in response to LPS. Specifically, IL-7-AS physically interacts with p300 to regulate histone acetylation levels around the promoter regions of these gene loci. Moreover, IL-7-AS and p300 complex modulate the assembly of SWI/SNF complex to the promoters. IL-7-AS regulates chemotaxis activity of monocytes to intestine epithelial cells with involvement of CCL2. Therefore, our data indicate a new promoting role for NF-κB/MAPK-responsive IL-7-AS in the transcriptional regulation of inflammatory genes in the innate immune system although modulation of histone acetylation around the promoters of related genes.

INDUCER OF CBF EXPRESSION 1 is a male fertility regulator impacting anther dehydration in Arabidopsis.

INDUCER OF CBF EXPRESSION 1 (ICE1) encodes a MYC-like basic helix-loop-helix (bHLH) transcription factor playing a critical role in plant responses to chilling and freezing stresses and leaf stomata development. However, no information connecting ICE1 and reproductive development has been reported. In this study, we show that ICE1 controls plant male fertility via impacting anther dehydration. The loss-of-function mutation in ICE1 gene in Arabidopsis caused anther indehiscence and decreased pollen viability as well as germination rate. Further analysis revealed that the anthers in the mutant of ICE1 (ice1-2) had the structure of stomium, though the epidermis did not shrink to dehisce. The anther indehiscence and influenced pollen viability as well as germination in ice1-2 were due to abnormal anther dehydration, for most of anthers dehisced with drought treatment and pollen grains from those dehydrated anthers had similar viability and germination rates compared with wild type. Accordingly, the sterility of ice1-2 could be rescued by ambient dehydration treatments. Likewise, the stomatal differentiation of ice1-2 anther epidermis was disrupted in a different manner compared with that in leaves. ICE1 specifically bound to MYC-recognition elements in the promoter of FAMA, a key regulator of guard cell differentiation, to activate FAMA expression. Transcriptome profiling in the anther tissues further exhibited ICE1-modulated genes associated with water transport and ion exchange in the anther. Together, this work reveals the key role of ICE1 in male fertility control and establishes a regulatory network mediated by ICE1 for stomata development and water movement in the anther.

The NF-κB-Responsive Long Noncoding RNA FIRRE Regulates Posttranscriptional Regulation of Inflammatory Gene Expression through Interacting with hnRNPU.

Long noncoding RNAs, a newly identified class of noncoding RNAs, are important regulators of gene expression in innate immunity. We report in this study that the transcription of FIRRE, a conserved long noncoding RNA between humans and mice, is controlled by NF-κB signaling in macrophages and intestinal epithelial cells. Functionally, FIRRE appears to positively regulate the expression of several inflammatory genes in macrophages or intestinal epithelial cells in response to LPS stimulation via posttranscriptional mechanisms. Specifically, FIRRE physically interacts with heterogeneous nuclear ribonucleoproteins U, regulating the stability of mRNAs of selected inflammatory genes through targeting the AU-rich elements of their mRNAs in cells following LPS stimulation. Therefore, our data indicate a new regulatory role for NF-κB-responsive FIRRE in the posttranscriptional regulation of inflammatory genes in the innate immune system.

[Study on the Effect of Overexpression of miR-18a on Cellular Proliferation and Migration by Targeting ATM in Human Colorectal Cancer Cells].

OBJECTIVES: To study the regulation to colon cancer cellular biological properties through miR-18a targeting ataxia-telangiectasia mutated gene (ATM). METHODS: A target of miR-18a was predicted by using bioinformatics tools. The miR-18a mimics and inhibitors were designed and synthesized. The expression of endogenous miR-18a in colon cancer cell line HCT116 was up-regulated or down-regulated by transfection. The effect of overexpression of miR-18a on cellular proliferation, invasion and migration via regulation of ATM gene expression was confirmed in vitro by using qRT-PCR, Western blot, MTT assay, clone forming assay and Transwell method, respectively. RESULTS: ATM was identified as a potential target gene of miR-18a in the bioinformatics analysis. In addition, through transient transfection leading to the overexpression of miR-18a in HCT116 cell, the expression level of ATM was decreased. Down-regulation of HCT116 cell proliferation activity while significantly reducing HCT116 cell clone forming ability, lateral migration ability and longitudinal invasion ability were observed after transfected with miR-18a mimics. All of the changes were related to the overexpression of miR-18a. CONCLUSIONS: miR-18a inhibited the proliferation and migration of colon cance cell HCT116 through negative regulation of ATM expression.

[MiRNA224 Regulation Role on RKIP Gene Expression and Methylation of miRNA224 Gene Promoter Region in Esophageal Squamous Cell Carcinoma].

OBJECTIVES: To study the expression levels of tumor suppressor gene RIKP and miRNA224 in esophageal squamous cell carcinoma (ESCC) tissues. To determine whether miRNA224 targets RKIP and the methylation status of miRNA224 gene promoter region in esophageal carcinoma. METHODS: The expression levels of RKIP and miRNA224 in ESCC and normal tissue were detected by using immunohistochemistry and real-time qPCR, respectively. Luciferase assay was used to determine the targeting of miRNA224 to RKIP. The methylation status of miRNA224 promoter region was studied by bisulfite sequencing PCR (BSP). RESULTS: In 40 cases of ESCC, RKIP expression was significantly lower than that of normal tissue; miRNA224 expression was higher in ESCC than in paracancerous tissue. Luciferase assay showed that miRNA224 targets RKIP 3'UTR thus inhibit its expression. The miRNA224 gene promoter region was hypomethylated in ESCC. CONCLUSIONS: Compared with normal tissue, in ESCC, RKIP was downregulated, while miRNA224 was upregulated, and the promoter region of miRNA224 gene was hypomethylated. RKIP is the target of miRNA224, which may be closely related to esophageal squamous cell carcinoma.

[SIRT1 promote GTM cell DSBs repair and resist cellular senescence].

OBJECTIVE: To study the relationship between SIRT1 and glaucoma trabecular meshwork cell (GTM) cell on DNA double-strand breaks (DSBs) repair capability and resist cellular senescence. METHODS: The expressions of SIRT1 in GTM and normal trabecular meshwork (HTM) cell detected by RT-RCR and Western blot; HTM and GTM cells divided into four groups separately: Res group (treat cells with 0.5 micromol/L Resveratrol for 24 h), SIRT1-ShRNA group (cells infected with recombinant SIRT1-ShRNA), microRNA34a group (cells infected with recombinant microRNA34a) and control group. The expression level of SIRT1 in groups was detected by Western blot. SA-beta-Gal staining was applied to each group of cells at 10 h, 32 h, 3 d and 6 d to evaluate the senescence of the cells. DSBs and the expression of gamma-H2AX after treated with 1.33 mol/L H2O2 at 0 h, 1 h, 2 h were detected by comet electrophoresis and Western blot. RESULTS: The expression of SIRT1 were observed in both HTM and GTM cells, but the expression level in HTM was higher than that of GTM cells have the ability to express SIRT1, however the expression of SIRT1 was lower than HTM. Expression levels of SIRT1 presented following treads: Res > Control > microRNA34a > SIRT1-ShRNA. The dgree of senescence in GTM was higher than that in HTM cells when detected at the same time point with SA-beta-Gal staining. In the same cell line, the signs of senescence were appeared firstly and seriously in the cells treated with SIRT1-ShRNA in a time-dependent manner. Differently, after 24 h treatment with Res, the degree of senescence was decreased. The DSBs in GTM group was more than that of HTM group after treatment with oxidant when detected with Comet Electrophoresis and the the trends of the change was SIRT1-ShRNA > microRNA34a > Control > Res. The similar results also observed in the expression of gamma-H2AX. CONCLUSION: SIRT1 may be useful in predicting the development and prognosis of glaucoma; Res promotes the expression of SIRT1 significantly, and the SIRT1 may protects GTM from oxidative stress-induced DSBs, aging even apoptosis, and promotes cell cycle arrest, which may provide a new target to treat glaucoma.

[Determination of six metal elements in animal samples by flame atomic absorption spectrometry with wet digestion].

The contents of 6 metal elements (Ca, Mg, K, Na, Cu and Fe ) were determined in serum, urine, feces and different tissue and organs (heart, kidney, stomach, liver, spleen, intestine and lung) of Wistar rats and mice by flame atomic absorption spectrometry (FAAS) with wet digestion. The samples were digested by the mixture of HNO3 and HClO4 (4 : 1, V/V) at 120 degrees C, the correlation coefficient for the standard curves was 0.999 4-0.999 8, the relative standard deviation (RSD) was from 0.33% to 4.52%, and the recovery for the samples was from 97.7% to 104.2%, meeting the demand of elements content determination in biological samples. The assay method for the determination of the 6 metal elements in animal samples established in this study has the advantages of easy operation, high sensitivity, less sample requiring and accurate results, and the method can be widely used in the determination of various metal elements in biological samples.