Systemic Inflammatory Response Index (SIRI) is associated with all-cause mortality and cardiovascular mortality in population with chronic kidney disease: evidence from NHANES (2001-2018).

Objective: To examine the correlation between SIRI and the probability of cardiovascular mortality as well as all-cause mortality in individuals with chronic kidney disease. Methods: A cohort of 3,262 participants from the US National Health and Nutrition Examination Survey (NHANES) database were included in the study. We categorized participants into five groups based on the stage of chronic kidney disease. A weighted Cox regression model was applied to assess the relationship between SIRI and mortality. Subgroup analyses, Kaplan-Meier survival curves, and ROC curves were conducted. Additionally, restricted cubic spline analysis was employed to elucidate the detailed association between SIRI and hazard ratio (HR). Results: This study included a cohort of 3,262 individuals, of whom 1,535 were male (weighted proportion: 42%), and 2,216 were aged 60 or above (weighted proportion: 59%). Following adjustments for covariates like age, sex, race, and education, elevated SIRI remained a significant independent risk factor for cardiovascular mortality (HR=2.50, 95%CI: 1.62-3.84, p<0.001) and all-cause mortality (HR=3.02, 95%CI: 2.03-4.51, p<0.001) in CKD patients. The restricted cubic spline analysis indicated a nonlinear relationship between SIRI and cardiovascular mortality, with SIRI>1.2 identified as an independent risk factor for cardiovascular mortality in CKD patients. Conclusion: Heightened SIRI independently poses a risk for both all-cause and cardiovascular mortality in chronic kidney disease patients, with potentially heightened significance in the early stages (Stage I to Stage III) of chronic kidney disease.

Analysis of necroptosis-related prognostic genes and immune infiltration in idiopathic pulmonary fibrosis.

Background: IPF is an undetermined, progressive lung disease. Necroptosis is a type of programmed apoptosis, which involved in the pathogenesis of lung diseases like COPD and ARDS. However, necroptosis in IPF have not been adequately studied. This study aimed to investigate the necroptosis in IPF and the relationship between necroptosis and immune infiltration, to construct a prognostic prediction model of IPF based on necroptosis-related genes. Methods: GSE110147 was downloaded from the GEO database and utilized to analyze the expression of necroptosis-related differentially expressed genes (NRDEGs). Then NRDEGs were used to construct protein-protein interaction (PPI) networks in the STRING database, and Cytoscape software was used to identify and visualize hub genes. Necroptosis-related prognosticgenes were explored in GSE70866, and a prognostic prediction model was constructed. The ImmuCellAI algorithm was utilized to analyze the landscape of immune infiltration in GSE110147. The single-cell RNA sequencing dataset GSE122960 was used to explore the association between necroptosis and type II alveolar epithelial cells (AT II) in IPF. The GSE213001 and GSE93606 were used for external validation. The expression of prognostic genes was quantified using RT-qPCRin the IPF A549 cell model, and was further verified by western blotting in the bleomycin-induced pulmonary fibrosis mouse model. Results: It was observed that necroptosis-related signaling pathways were abundantly enriched in IPF. 29 NRDEGs were screened, of which 12 showed consistent expression trends in GSE213001. Spearman correlation analysis showed that the expression of NRDEGs was positively correlated with the infiltration of proinflammatory immune cells, and negatively correlated with the infiltration of anti-inflammatory immune cells. NRDEGs, including MLKL, were highly expressed in AT II of fibrotic lung tissue. A necroptosis-related prediction model was constructed based on 4 NRDEGsby the cox stepwise regression. In the validation dataset GSE93606, the prognostic prediction model showed good applicability. The verification results of RT-qPCR and western blotting showed the reliability of most of the conclusions. Conclusions: This study revealed that necroptosis existed in IPF and might occur in AT II. Necroptosis was associated with immune infiltration, suggesting that necroptosis of AT II might involve in IPF by activating immune infiltration and immune response.

Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model.

BACKGROUND: Airway epithelial cells (AECs) with impaired barrier function contribute to airway remodeling through the activation of epithelial-mesenchymal trophic units (EMTUs). Although the decreased expression of ITGB4 in AECs is implicated in the pathogenesis of asthma, how ITGB4 deficiency impacts airway remodeling remains obscure. OBJECTIVE: This study aims to determine the effect of epithelial ITGB4 deficiency on the barrier function of AECs, asthma susceptibility, airway remodeling, and EMTU activation. METHODS: AEC-specific ITGB4 conditional knockout mice (ITGB4-/-) were generated and an asthma model was employed by the sensitization and challenge of house dust mite (HDM). EMTU activation-related growth factors were examined in ITGB4-silenced primary human bronchial epithelial cells of healthy subjects after HDM stimulation. Dexamethasone, the inhibitors of JNK phosphorylation or FGF2 were administered for the identification of the molecular mechanisms of airway remodeling in HDM-exposed ITGB4-/- mice. RESULTS: ITGB4 deficiency in AECs enhanced asthma susceptibility and airway remodeling by disrupting airway epithelial barrier function. Aggravated airway remodeling in HDM-exposed ITGB4-/- mice was induced through the enhanced activation of EMTU mediated by Src homology domain 2-containing protein tyrosine phosphatase 2/c-Jun N-terminal kinase/Jun N-terminal kinase-dependent transcription factor/FGF2 (SHP2/JNK/c-Jun/FGF2) signaling pathway, which was partially independent of airway inflammation. Both JNK and FGF2 inhibitors significantly inhibited the aggravated airway remodeling and EMTU activation in HDM-exposed ITGB4-/- mice. CONCLUSIONS: Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model of asthma through enhanced EMTU activation that is regulated by the SHP2/JNK/c-Jun/FGF2 pathway.

A Comprehensive Mass Spectrometry-Based Workflow for Clinical Metabolomics Cohort Studies.

As a comprehensive analysis of all metabolites in a biological system, metabolomics is being widely applied in various clinical/health areas for disease prediction, diagnosis, and prognosis. However, challenges remain in dealing with the metabolomic complexity, massive data, metabolite identification, intra- and inter-individual variation, and reproducibility, which largely limit its widespread implementation. This study provided a comprehensive workflow for clinical metabolomics, including sample collection and preparation, mass spectrometry (MS) data acquisition, and data processing and analysis. Sample collection from multiple clinical sites was strictly carried out with standardized operation procedures (SOP). During data acquisition, three types of quality control (QC) samples were set for respective MS platforms (GC-MS, LC-MS polar, and LC-MS lipid) to assess the MS performance, facilitate metabolite identification, and eliminate contamination. Compounds annotation and identification were implemented with commercial software and in-house-developed PAppLineTM and UlibMS library. The batch effects were removed using a deep learning model method (NormAE). Potential biomarkers identification was performed with tree-based modeling algorithms including random forest, AdaBoost, and XGBoost. The modeling performance was evaluated using the F1 score based on a 10-times repeated trial for each. Finally, a sub-cohort case study validated the reliability of the entire workflow.

NCAPG2 Maintains Cancer Stemness and Promotes Erlotinib Resistance in Lung Adenocarcinoma.

Erlotinib is a highly specific and reversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), but resistance inevitably develops as the disease progresses. Erlotinib resistance and cancer stem cells (CSCs) are poor factors hindering the prognosis of patients with lung adenocarcinoma (LUAD). Although studies have shown that erlotinib resistance and CSCs can jointly promote cancer development, the mechanism is currently unclear. Here, we investigated the potential biomarker and molecular mechanism of erlotinib resistance and cancer stemness in LUAD. An erlotinib resistance model based on four genes was constructed from The Cancer Genome Atlas (TCGA), the GEO database, the Cancer Cell Line Encyclopedia (CCLE), and the Genomics of Drug Sensitivity in Cancer (GDSC). Through multiple bioinformatic analyses, NCAPG2 was identified as a key gene for erlotinib resistance and stemness in LUAD. Further in vitro experiments demonstrated that NCAPG2 maintains stemness and contributes to erlotinib resistance in LUAD. In summary, NCAPG2 plays a vital role in stemness and erlotinib resistance in LUAD.

MiR-223-3p-loaded exosomes from bronchoalveolar lavage fluid promote alveolar macrophage autophagy and reduce acute lung injury by inhibiting the expression of STK39.

This study investigated the molecular mechanism by which bronchoalveolar lavage fluid exosomes (BALF-exo) alleviated acute lung injury (ALI). BALF-exo was isolated from mice. LPS was used to induce inflammation in rat alveolar macrophages (NR8383). NR8383 cell models were treated with BALF-exo or BALF-exo loaded with miR-223-3p mimics/inhibitors, or STK39 was overexpressed in NR8383 cells before LPS and BALF-exo treatment. These cells were subjected to apoptosis, autophagy, and inflammation assays. RNA immunoprecipitation and dual-luciferase reporter assay were conducted to verify the binding between miR-223-3p and STK39. LPS-induced ALI mouse models were treated with BALF-exo loaded with miR-223-3p mimics. miR-223-3p was lowly expressed in BALF-exo from LPS-treated mice. BALF-exo loaded with miR-223-3p mimics increased viability and autophagy and decreased apoptosis and inflammation in NR8383 cell models. Inhibition of miR-223-3p in BALF-exo or overexpression of STK39 in NR8383 cells repressed the therapeutic effect of BALF-exo in LPS-treated NR8383 cells. STK39 was a target gene of miR-223-3p. miR-223-3p shuttled by BALF-exo negatively regulated the expression of STK39 in NR8383 cells. BALF-exo loaded with miR-223-3p mimics also reduced lung injuries in ALI mice. In conclusion, miR-223-3p loaded in BALF-exo alleviates ALI by targeting STK39 in alveolar macrophages.

DNA Damage Response Gene-Based Subtypes Associated With Clinical Outcomes in Early-Stage Lung Adenocarcinoma.

DNA damage response (DDR) pathways play a crucial role in lung cancer. In this retrospective analysis, we aimed to develop a prognostic model and molecular subtype based on the expression profiles of DDR-related genes in early-stage lung adenocarcinoma (LUAD). A total of 1,785 lung adenocarcinoma samples from one RNA-seq dataset of The Cancer Genome Atlas (TCGA) and six microarray datasets of Gene Expression Omnibus (GEO) were included in the analysis. In the TCGA dataset, a DNA damage response gene (DRG)-based signature consisting of 16 genes was constructed to predict the clinical outcomes of LUAD patients. Patients in the low-DRG score group had better outcomes and lower genomic instability. Then, the same 16 genes were used to develop DRG-based molecular subtypes in the TCGA dataset to stratify early-stage LUAD into two subtypes (DRG1 and DRG2) which had significant differences in clinical outcomes. The Kappa test showed good consistency between molecular subtype and DRG (K = 0.61, p < 0.001). The DRG subtypes were significantly associated with prognosis in the six GEO datasets (pooled estimates of hazard ratio, OS: 0.48 (0.41-0.57), p < 0.01; DFS: 0.50 (0.41-0.62), p < 0.01). Furthermore, patients in the DRG2 group benefited more from adjuvant therapy than standard-of-care, which was not observed in the DRG1 group. In summary, we constructed a DRG-based molecular subtype that had the potential to predict the prognosis of early-stage LUAD and guide the selection of adjuvant therapy for early-stage LUAD patients.

The Core Role of Neutrophil-Lymphocyte Ratio to Predict All-Cause and Cardiovascular Mortality: A Research of the 2005-2014 National Health and Nutrition Examination Survey.

Objective: To further supplement the previous research on the relationship between neutrophil-lymphocyte ratio (NLR) and all-cause and cardiovascular mortality, and construct clinical models to predict mortality. Methods: A total number of 2,827 observers were included from the National Health and Nutrition Examination Survey (NHANES) database in our research. NLR was calculated from complete blood count. According to the quartile of baseline NLR, those observers were divided into four groups. A multivariate weighted Cox regression model was used to analyze the association of NLR with mortality. We constructed simple clinical prognosis models by nomograms. Kaplan-Meier survival curves were used to depict cause-specific mortality. Restricted cubic spline regression was used to make explicit relationships between NLR and mortality. Results: This study recruited 2,827 subjects aged ≥ 18 years from 2005 to 2014. The average age of these observers was 51.55 ± 17.62, and 57.69% were male. NLR is still an independent predictor, adjusted for age, gender, race, drinking, smoking, dyslipidemia, and other laboratory covariates. The area under the receiver operating characteristic curves (AUCs) of NLR for predicting all-cause mortality and cardiovascular mortality were 0.632(95% CI [0599, 0.664]) and 0.653(95% CI [0.581, 0.725]), respectively, which were superior to C-reactive protein (AUCs: 0.609 and 0.533) and WBC (AUCs: 0.522 and 0.513). The calibration and discrimination of the nomograms were validated by calibration plots and concordance index (C-index), and the C-indexes (95% CIs) of nomograms for all-cause and cardiovascular mortality were 0.839[0.819,0.859] and 0.877[0.844,0.910], respectively. The restricted cubic spline showed a non-linear relationship between NLR and mortality. NLR > 2.053 might be a risk factor for mortality. Conclusion: There is a non-linear relationship between NLR and mortality. NLR is an independent factor related to mortality, and NLR > 2.053 will be a risk factor for prognosis. NLR and nomogram should be promoted to medical use for practicality and convenience.

Early stage of antibody-mediated rejection after lung transplantation： A case report and literature review. / 肺移植术后早期抗体介导排斥反应1ä¾‹åŠæ–‡çŒ®å¤ä¹ .

Antibody-mediated rejection (AMR) is a rare and serious complication after lung transplantation, with no characteristic of pathological manifestation, no systematic standard treatment, and the poor efficacy and prognosis. We reported a case of early AMR after lung transplantation and the relevant literature has been reviewed. A male patient presented with symptoms of cold 99 days after transplantation and resolved after symptomatic treatment. He admitted to the hospital 14 days later because of a sudden dyspnea and fever. Anti-bacteria, anti-fungi, anti-virus, and anti-pneumocystis carinii treatment were ineffective, and a dose of 1 000 mg methylprednisolone did not work too. The patient's condition deteriorated rapidly and tracheal intubation was done to maintain breathing. Serum panel reactive antibody and donor specific antibody showed postive in humen leukocyte antigen (HLA) II antibody. Pathological examination after transbronchial transplantation lung biopsy showed acute rejection. Clinical AMR was diagnosed combined the donor-specific antibody with the pathological result. The patient was functionally recovered after combined treatment with thymoglobuline, rituximab, plasmapheresis, and immunoglobulin. No chronic lung allograft dysfunction was found after 3 years follow up. We should alert the occurrence of AMR in lung transplantation recipient who admitted to hospital with a sudden dyspnea and fever while showed no effect after common anti-infection and anti-rejection treatment. Transbronchial transplantation lung biopsy and the presence of serum donor-specific antibody are helpful to the diagnosis. The treatment should be preemptive and a comprehensive approach should be adopted.

A localization-independent approach for invisible and impalpable ground-glass opacity nodules detection in an in vitro lung specimen: two case reports.

A growing number of ground-glass opacity (GGO) nodules are screened out in lungs. Small GGOs are frequently neither visible nor palpable, thus undetectable during operation. Various nodule localization techniques have been developed to facilitate the intraoperative detection of GGO nodules; however, general localization techniques are infeasible or inappropriate in some cases. The detection of small GGO is a great challenge, even within a surgical specimen in the absence of preoperative localization. A localization-independent approach for GGO detection is urgently needed. Herein, we report two cases with invisible and impalpable small GGO which were not appropriate for preoperative localization. The lesions were anatomically resected under the guidance of three-dimensional (3D) reconstruction and got an adequate margin distance. A vessel (artery, vein, or bronchus) which had advanced into or immediately adjacent to the nodule was assigned as a reference vessel. By dissecting and tracing the reference vessel from proximal to distal, the GGO lesions were successfully detected in the surgical specimens, to the eventual obtainment of an accurate pathological diagnosis. Via the two case reports, we introduced an easily handled approach, namely dissecting and tracing a reference vessel, for GGO detection. The novel approach was first described. Combined with precise anatomical segmentectomy guided by 3D reconstruction, it provides an alternative scheme for GGO resection with no need for preoperative localization.

Formation, contents, functions of exosomes and their potential in lung cancer diagnostics and therapeutics.

Lung cancer is the leading cause of cancer-related death worldwide due to diagnosis in the advanced stage and drug resistance in the subsequent treatments. Development of novel diagnostic and therapeutic methods is urged to improve the disease outcome. Exosomes are nano-sized vehicles which transport different types of biomolecules intercellularly, including DNA, RNA and proteins, and are implicated in cross-talk between cells and their surrounding microenvironment. Tumor-derived exosomes (TEXs) have been revealed to strongly influence the tumor microenvironment, antitumor immunoregulatory activities, tumor progression and metastasis. Potential of TEXs as biomarkers for lung cancer diagnosis, prognosis and treatment prediction is supported by numerous studies. Moreover, exosomes have been proposed to be promising drug carriers. Here, we review the mechanisms of exosomal formation and uptake, the functions of exosomes in carcinogenesis, and potential clinical utility of exosomes as biomarkers, tumor vaccine and drug delivery vehicles in the diagnosis and therapeutics of lung cancer.

Downregulation of miR-223 promotes HMGB2 expression and induces oxidative stress to activate JNK and promote autophagy in an in vitro model of acute lung injury.

BACKGROUND: Excessive autophagic activity in alveolar epithelial cells is one of the main causes of acute lung injury (ALI), but the underlying molecular mechanism has not been fully elucidated. Previous studies have shown that microRNAs (miRs) are involved in regulating autophagy in several diseases. This study aimed to determine the role of miR-223 in excessive autophagic activity in alveolar epithelial cells and the underlying mechanism to identify a novel therapeutic targets for the development of new drugs to treat acute respiratory distress syndrome (ARDS). METHODS: A549 cells were treated with lipopolysaccharide (LPS) to establish an ALI in vitro model. The expression of miR-223 and its role of miR-223 in regulating oxidative stress and autophagy in the LPS-treated A549 cells, were examined using RT-PCR, flow cytometry and ELISA. A luciferase reporter assay was performed to verify the interaction between miR-223 and the high-mobility group box 2 (HMGB2) protein. RESULTS: The results showed that the LPS treatment downregulated miR-223 expression in alveolar epithelial cells. We further proved that miR-223 directly targeted the 3-untranslated region of the HMGB2 gene and the downregulation of miR-223 increased HMGB2 protein level, which activated the JNK signalling pathway and thus induced oxidative stress and autophagy in LPS-treated alveolar epithelial cells. Knockdown of HMGB2 protein deactivated the JNK signalling pathway and inhibited autophagy and oxidative stress in alveolar epithelial cells. CONCLUSIONS: The results of this study suggest that miR-223 regulates oxidative stress and autophagy in alveolar epithelial cells by targeting HMGB2 via the JNK signalling pathway.

Uncovering fungal community composition in natural habitat of Ophiocordyceps sinensis using high-throughput sequencing and culture-dependent approaches.

BACKGROUND: The fungal communities inhabiting natural Ophiocordyceps sinensis play critical ecological roles in alpine meadow ecosystem, contribute to infect host insect, influence the occurrence of O. sinensis, and are repertoire of potential novel metabolites discovery. However, a comprehensive understanding of fungal communities of O. sinensis remain elusive. Therefore, the present study aimed to unravel fungal communities of natural O. sinensis using combination of high-throughput sequencing and culture-dependent approaches. RESULTS: A total of 280,519 high-quality sequences, belonging to 5 fungal phyla, 15 classes, 41 orders, 79 families, 112 genera, and 352 putative operational taxonomic units (OTUs) were obtained from natural O. sinensis using high-throughput sequencing. Among of which, 43 genera were identified in external mycelial cortices, Ophiocordyceps, Sebacinia and Archaeorhizomyces were predominant genera with the abundance of 95.86, 1.14, 0.85%, respectively. A total of 66 genera were identified from soil microhabitat, Inocybe, Archaeorhizomyces, unclassified Thelephoraceae, Tomentella, Thelephora, Sebacina, unclassified Ascomycota and unclassified fungi were predominant genera with an average abundance of 53.32, 8.69, 8.12, 8.12, 7.21, 4.6, 3.08 and 3.05%, respectively. The fungal communities in external mycelial cortices were significantly distinct from soil microhabitat. Meanwhile, seven types of culture media were used to isolate culturable fungi at 16 °C, resulted in 77 fungal strains identified by rDNA ITS sequence analysis, belonging to 33 genera, including Ophiocordyceps, Trichoderma, Cytospora, Truncatella, Dactylonectria, Isaria, Cephalosporium, Fusarium, Cosmospora and Paecilomyces, etc.. Among all culturable fungi, Mortierella and Trichoderma were predominant genera. CONCLUSIONS: The significantly differences and overlap in fungal community structure between two approaches highlight that the integration of high-throughput sequencing and culture-dependent approaches would generate more information. Our result reveal a comprehensive understanding of fungal community structure of natural O. sinensis, provide new insight into O. sinensis associated fungi, and support that microbiota of natural O. sinensis is an untapped source for novel bioactive metabolites discovery.

[Tumor infiltrating T lymphocyte components in malignant pleural effusion of lung adenocarcinoma and their killing activities to autologous tumor cells].

OBJECTIVE: To analyze the components of tumor infiltrating T lymphocyte (TIL) cells in malignant pleural effusion of lung adenocarcinoma, and evaluate their killing activities to autologous tumor cells. 
 Methods: Malignant pleural effusions were collected from 17 patients with lung adenocarcinoma. Mononuclear cells were isolated by Ficoll density gradient centrifugation and flow cytometer was used to analyze TIL cell components. TIL and tumor cells were separated through adherent culture. The tumor cells were identified via intramuscular injection of adherent cells into nude mice and the killing effect of cultured lymphocytes on autologous tumor cells was studied.
 Results: Of the TIL in malignant pleural effusions, T cells accounted for 60.6%-79.3%, while T helper cells were significantly higher than T killer cells (36.63%±1.90% vs 24.64%±2.32%, P<0.001). There were also natural killer (NK) cells and NK T cells in the effusions. Tumor cells were successfully isolated and cultured. The killing activity of cultured TIL to autologous tumor cells was 39.14%±12.04%, and the killing activity of TIL with high proliferation rate to autologous tumor cells was higher than that of low proliferation group (50.51%±3.80% vs 29.04%±5.77%, P<0.001).
 Conclusion: T lymphocytes are the major components of TIL in malignant pleural effusions derived from lung adenocarcinoma, and T helper cells are more than T killer cells. The killing activity of TIL with strong proliferation ability to autologous tumor cells is higher than that of TIL with weak proliferation ability. Therefore, cells from malignant pleural effusions could be used for cellular immunotherapy against tumor.

ZCCHC10 suppresses lung cancer progression and cisplatin resistance by attenuating MDM2-mediated p53 ubiquitination and degradation.

The activation of p53 tumor suppressor is essential for preventing abnormal cell proliferation and carcinogenesis. ZCCHC10 was previously identified as a potential p53-interacting partner in a yeast two-hybrid screen, but the interaction in cells and its subsequent influence on p53 activity and cancer development have not been investigated. In this paper, we demonstrate that ZCCHC10 expression levels are statistically lower in lung adenocarcinoma tissues than the corresponding adjacent noncancerous tissues, and decreased expression of ZCCHC10 mRNA predicts poorer survival of the patients. Ectopic expression of ZCCHC10 in lung cancer cells harboring wild-type p53 dramatically suppresses cell proliferation, colony formation, migration, invasion and cisplatin resistance in vitro, as well as tumor growth and metastasis in vivo. Conversely, knockdown of ZCCHC10 exerts opposite effects in the normal lung cell Beas-2b. However, ZCCHC10 has no influence on the biological behaviors of p53-null (H358) or p53-mutant (H1437) lung cancer cells. Mechanistically, ZCCHC10 binds and stabilizes p53 by disrupting the interaction between p53 and MDM2. The p53 inhibitor pifithrin-α attenuated the influences of ZCCHC10 overexpression on p53 pathway, cell cycle, apoptosis, and epithelial-mesenchymal transition, whereas the p53 activator Nutlin3 could reverse the effects of ZCCHC10 knockdown. Collectively, our results indicate that ZCCHC10 exerts its tumor-suppressive effects by stabilizing the p53 protein and can be used a potential prognostic marker and therapeutic target in lung adenocarcinoma.

The Salvia miltiorrhiza NAC transcription factor SmNAC1 enhances zinc content in transgenic Arabidopsis.

NAC transcription factors play important roles in plant biological processes, including plant development, environmental stress responses and element enrichment. A novel NAC transcription factor gene, designated SmNAC1, was isolated from Salvia miltiorrhiza. SmNAC1 was localized in the nucleus in onion protoplasts and exhibited transcriptional activation activities in yeast. In addition, the SmNAC1 protein could specifically bind to the cis-elements of the NAC proteins. SmNAC1 was expressed at a higher level in the leaves of S. miltiorrhiza, indicating that SmNAC1 might be involved in the transportation of zinc. To examine the function of SmNAC1, transgenic Arabidopsis plants overexpressing SmNAC1 were generated. Zinc content assays in the transgenic plants demonstrated that overexpressed SmNAC1 plants had enhanced tolerance to high zinc concentrations, and zinc was enriched in the shoot tissues. Our results demonstrate that SmNAC1 plays important roles in the response to zinc stress. Zinc was mainly enriched in the leaves of S. miltiorrhiza and the shoot tissues of transgenic Arabidopsis plants. SmNAC1 might participate in zinc transportation from the roots to the shoots, that constitutes a useful gene for improving zinc content in plants.

[Establishment of SeMNPV persistent infection in Spotoptera exigua cells].

Persistent baculovirus infection is observed frequently in insect populations. Persistent infection can be transformed to a replicative and infective state caused by stress factors and plays an important role in regulating the size of insect population and in epizoology of baculoviruses. The aim of this study is to establish a persistently baculovirus-infected cell system to explore the molecular mechanisms of baculoviral persistence. Spodoptera exigua nucleopolyhedrovirus (SeMNPV) was serially undiluted passaged in Se301 cells to reduce virulence. Upon infection of Se301 cells with the SeMNPV up to passage 8, a few cells survived even if most of cells died due to virus infection. The surviving cells were passaged and designated as P8-Se301 cell strain. P8-Se301 cells had a population doubling time of 58-65 hours and grew slower than Se301 cells. Light microscopy and electron microscopy observation showed symptom of baculovirus infection, such as virogenic stroma, viral particles and occlusion bodies, in some of P8-Se301 cells. End-point dilution assay and infectious center assay showed that 4.14% +/- 0.99% cells continually released infectious progeny virus which replicated slower than SeMNPV in Se301 cells. The result indicated that P8-Se301 cells show a typical character trait of baculovirus persistent infection.

Establishment of SeMNPV persistent infection in Spotoptera exigua cells / 病毒学报

Persistent baculovirus infection is observed frequently in insect populations. Persistent infection can be transformed to a replicative and infective state caused by stress factors and plays an important role in regulating the size of insect population and in epizoology of baculoviruses. The aim of this study is to establish a persistently baculovirus-infected cell system to explore the molecular mechanisms of baculoviral persistence. Spodoptera exigua nucleopolyhedrovirus (SeMNPV) was serially undiluted passaged in Se301 cells to reduce virulence. Upon infection of Se301 cells with the SeMNPV up to passage 8, a few cells survived even if most of cells died due to virus infection. The surviving cells were passaged and designated as P8-Se301 cell strain. P8-Se301 cells had a population doubling time of 58-65 hours and grew slower than Se301 cells. Light microscopy and electron microscopy observation showed symptom of baculovirus infection, such as virogenic stroma, viral particles and occlusion bodies, in some of P8-Se301 cells. End-point dilution assay and infectious center assay showed that 4.14% +/- 0.99% cells continually released infectious progeny virus which replicated slower than SeMNPV in Se301 cells. The result indicated that P8-Se301 cells show a typical character trait of baculovirus persistent infection.