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BACKGROUND: Chemotherapy resistance is the major cause of recurrence in patients with colorectal cancer (CRC). A previous study found that Fusobacterium (F.) nucleatum promoted CRC chemoresistance. Additionally, metformin rescued F. nucleatum-induced tumorigenicity of CRC. Here, we aimed to investigate whether metformin could revert F. nucleatum-induced chemoresistance and explore the mechanism. METHODS: The role of metformin in F. nucleatum-infected CRC cells was confirmed using cell counting kit 8 assays and CRC xenograft mice. Stemness was identified by tumorsphere formation. Bioinformatic analyses were used to explore the regulatory molecules involved in metformin and F. nucleatum-mediated regulation of the sonic hedgehog pathway. RESULTS: We found that metformin abrogated F. nucleatum-promoted CRC resistance to chemotherapy. Furthermore, metformin attenuated F. nucleatum-stimulated stemness by inhibiting sonic hedgehog signaling. Mechanistically, metformin diminished sonic hedgehog signaling proteins by targeting the MYC/miR-361-5p cascade to reverse F. nucleatum-induced stemness, thereby rescuing F. nucleatum-triggered chemoresistance in CRC. CONCLUSIONS: Metformin acts on F. nucleatum-infected CRC via the MYC/miR-361-5p/sonic hedgehog pathway cascade, subsequently reversing stemness and abolishing F. nucleatum-triggered chemoresistance. Our results identified metformin intervention as a potential clinical treatment for patients with chemoresistant CRC with high amounts of F. nucleatum.
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Neoplasias Colorretais , MicroRNAs , Humanos , Animais , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Hedgehog/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Fusobacterium nucleatum , Resistencia a Medicamentos Antineoplásicos/genéticaRESUMO
There are many kinds of agricultural pathogenic fungi, which may belong to pathogenic fungi in different species, such as Fusarium, Alternaria, Colletotrichum, Phytophthora, and other agricultural pathogens. Pathogenic fungi from different sources are widely distributed in agriculture, which threaten the lives of crops around the world and caused great damage to agricultural production and economic benefits. Due to the particularity of the marine environment, marine-derived fungi could produce natural compounds with unique structures, rich diversities, and significant bioactivities. Since marine natural products with different structural characteristics could inhibit different kinds of agricultural pathogenic fungi, secondary metabolites with antifungal activity could be used as lead compounds against agricultural pathogenic fungi. In order to summarize the structural characteristics of marine natural products against agricultural pathogenic fungi, this review systematically overview the activities against agricultural pathogenic fungi of 198 secondary metabolites from different marine fungal sources. A total of 92 references published from 1998 to 2022 were cited. KEY POINTS: ⢠Pathogenic fungi, which could cause damage to agriculture, were classified. ⢠Structurally diverse antifungal compounds from marine-derived fungi were summarized. ⢠The sources and distributions of these bioactive metabolites were analyzed.
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Produtos Biológicos , Fusarium , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Produtos Biológicos/metabolismo , Fungos/metabolismo , Alternaria/metabolismo , Fusarium/metabolismoRESUMO
BACKGROUND AND AIMS: Patients with liver fibrosis who have pain in the liver region may have changed nerve factors. The expression of neurokines and hepatic nerves in liver fibrosis, however, was little understood. In order to better understand how liver fibrosis develops, we plan to look into the hepatic nerve and neurokine changes and how they relate to hepatic stellate cells (HSCs). METHODS: The expression of neurokines in liver samples from 55 chronic hepatitis B patients and the carbon tetrachloride (CCl4) animal model were studied. The co-staining of Nissl and α-SMA allowed us to investigate the neurons and their interaction with α-SMA in fibrotic livers, as well as the expression of the glial cell marker glial fibrillary acidic protein (GFAP) and its relationship with α-SMA, a marker of HSCs. SH-SY5Y cells were treated with a fibrotic serum to imitate the hepatic microenvironment on neuronal cells. We also used brain-derived neurotrophic factor (BDNF) to stimulate mouse primary HSCs and LX2. RESULTS: The levels of mRNA for neurokines such as BDNF, GFAP, and growth-associated protein (GAP43) are significantly increased in both human and animal liver fibrosis. As liver fibrosis advances, we found that Nissl bodies and α-SMA may co-localize, suggesting a connection between hepatic nerves and HSCs. Human fibrotic serum may increase neurkines, notably BDNF, in SH-SY5Y cells. We also found that BDNF increased pro-inflammatory cytokines and fibrogenic markers in hHSCs. CONCLUSIONS: Patients with hepatic fibrosis had significantly higher levels of BDNF, GFAP, GAP43, and nerve fibers. HSC and nerve fibers interact, and nerves also create neurogenic substances that promote liver fibrosis and HSC activation.
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Células Estreladas do Fígado , Neuroblastoma , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Tetracloreto de Carbono/toxicidade , Citocinas/metabolismo , Fibrose , Proteína Glial Fibrilar Ácida/metabolismo , Células Estreladas do Fígado/metabolismo , Humanos , Fígado/metabolismo , Cirrose Hepática/patologia , Camundongos , Neuroblastoma/patologia , RNA Mensageiro/metabolismo , Microambiente TumoralRESUMO
BACKGROUND: Splicing factor SRSF3 is an oncogene and overexpressed in various kinds of cancers, however, the function and mechanism involved in colorectal cancer (CRC) remained unclear. The aim of this study was to explore the relationship between SRSF3 and carcinogenesis and progression of CRC. METHODS: The expression of SRSF3 in CRC tissues was detected by immunohistochemistry. The proliferation and invasion rate was analyzed by CCK-8 assay, colony formation assay, transwell invasion assay and xenograft experiment. The expression of selected genes was detected by western blot or real time PCR. RESULTS: SRSF3 is overexpressed in CRC tissues and its high expression was associated with CRC differentiation, lymph node invasion and AJCC stage. Upregulation of SRSF3 was also associated with shorter overall survival. Knockdown of SRSF3 in CRC cells activated ArhGAP30/Ace-p53 and decreased cell proliferation, migration and survival; while ectopic expression of SRSF3 attenuated ArhGAP30/Ace-p53 and increases cell proliferation, migration and survival. Targeting SRSF3 in xenograft tumors suppressed tumor progression in vivo. CONCLUSIONS: Taken together, our data identify SRSF3 as a regulator for ArhGAP30/Ace-p53 in CRC, and highlight potential prognostic and therapeutic significance of SRSF3 in CRC.
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BACKGROUND: PD-L1 expression on tumor-infiltrating lymphocytes (TILs) has recently been reported as a biomarker for colorectal cancer (CRC). However, the prognostic and clinical significance of PD-L1 on TILs in CRC remains controversial. We performed this meta-analysis to evaluate the association between the PD-L1 expression on TILs and clinicopathological features and prognosis of CRC patients. METHODS: A comprehensive literature search for relevant studies published up to Feb 2020 was performed using Medline, Embase, and Web of Science. Odds ratio (OR) with 95% CI was selected to appraise the correlation between PD-L1 expression on TILs with prognostic and clinicopathological characteristics of CRC patients. Begg's and Egger's test were used to assess publication bias. The statistical analysis was conducted using Stata software. RESULTS: A total of 19 studies including 5,213 CRC cases were included in this meta-analysis. The pooled results showed that PD-L1 overexpression on TILs was relevant to longer OS (OR = 1.36, 95% CI = 1.19 - 1.55, p < 0.01) and longer DFS/RFS (OR = 1.22, 95% CI = 1.03 - 1.44, p = 0.02). Moreover, CRC patients with high expression of PD-L1 on TILS was associated with lower T stage (OR = 2.30, 95% CI = 1.85 - 2.87, p < 0.01), less lymph node in-vasion (OR = 1.48, 95% CI = 1.03 - 2.13, p = 0.03), less distant metastasis (OR = 2.56, 95% CI = 1.81 - 3.64, p < 0.01), earlier TNM stage (OR = 1.93, 95% CI = 1.34 - 2.66, p < 0.01), later tumor grade (OR = 0.38, 95% CI = 0.23 - 0.62, p < 0.01) and high MSI status (OR = 0.36, 95% CI = 0.25 - 0.52, p < 0.01). But it is not related to tumor size, tumor differentiation, MMR status, BRAF mutant, and KRAS mutant. CONCLUSIONS: This meta-analysis revealed that PD-L1 expression on TILs can serve as a signiï¬cant biomarker for positive prognosis and clinicopathological features of CRC. Our results may provide some useful information when using PD-L1 expression to predict the survival of CRC patients and to select the beneficial CRC patients from PD-1/PD-L1 antibody treatment.
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Antígeno B7-H1 , Neoplasias Colorretais , Linfócitos do Interstício Tumoral , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Neoplasias Colorretais/genética , Humanos , Estadiamento de Neoplasias , PrognósticoRESUMO
The transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) is a single-pass transmembrane protein, and it is downregulated in human gastric cancer and levels correlate with tumor progression and time of survival. However, the mechanism of its dysregulation in gastric cancer is little known. Here we investigate its regulatory mechanism and the bidirectional regulation between TMEFF2 and STAT3 in gastric carcinogenesis. TMEFF2 expression was decreased after Helicobacter pylori (H. pylori) infection in vivo and in vitro. STAT3 directly binds to the promoter of TMEFF2 and regulates H. pylori-induced TMEFF2 downregulation in normal gastric GES-1 cells and gastric cancer AGS cells. Conversely, TMEFF2 may suppress the phosphorylation of STAT3 and TMEFF2-induced downregulation of STAT3 phosphorylation may depend on SHP-1. A highly inverse correlation between the expression of TMEFF2 and pSTAT3 was also revealed in gastric tissues. We now show the deregulation mechanism of TMEFF2 in gastric carcinogenesis and identify TMEFF2 as a new target gene of STAT3. The phosphorylation of STAT3 may be negatively regulated by TMEFF2, and the bidirectional regulation between TMEFF2 and STAT3 may contribute to H. pylori-associated gastric carcinogenesis.
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Transformação Celular Neoplásica/patologia , Mucosa Gástrica/patologia , Regulação Neoplásica da Expressão Gênica , Infecções por Helicobacter/patologia , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Fator de Transcrição STAT3/metabolismo , Neoplasias Gástricas/patologia , Animais , Transformação Celular Neoplásica/metabolismo , Imunoprecipitação da Cromatina , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Gerbillinae , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Humanos , Técnicas Imunoenzimáticas , Masculino , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/genética , Transdução de Sinais , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Células Tumorais CultivadasRESUMO
Persistent infection with Helicobacter pylori (H. pylori) contributes to gastric diseases including chronic gastritis and gastric cancer. However, the pathogenesis of this carcinogenic bacterium has not been completely elucidated. Here, we report that H. pylori rapidly triggers STAT3 signaling and induces STAT3-dependent COX-2 expression both in vitro and in vivo. STAT3 upregulates COX-2 by binding to and increasing the activity of COX-2 promoter. COX-2 in turn regulates IL-6/STAT3 signaling under basal conditions and during H. pylori infection. These findings suggest that a positive feedback loop between STAT3 and COX-2 exists in the basal condition and H. pylori infectious condition. Immunohistochemical staining revealed that H. pylori-positive gastritis tissues exhibited markedly higher levels of pSTAT3(Tyr705) than H. pylori-negative ones. High pSTAT3(Tyr705) levels are correlated with intestinal metaplasia and dysplasia, suggesting pSTAT3(Tyr705) may be useful in the early detection of gastric tumorigenesis. Additionally, a strong positive correlation between STAT3/pSTAT3(Tyr705) levels and COX-2 expression was identified in gastritis and gastric cancer tissues. Together, these findings provide new evidence for a positive feedback loop between STAT3 signaling and COX-2 in H. pylori pathogenesis and may lead to new approaches for early detection and effective therapy of gastric cancer
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Carcinogênese/metabolismo , Ciclo-Oxigenase 2/biossíntese , Infecções por Helicobacter/metabolismo , Fator de Transcrição STAT3/metabolismo , Neoplasias Gástricas/metabolismo , Animais , Western Blotting , Carcinogênese/genética , Linhagem Celular , Imunoprecipitação da Cromatina , Ciclo-Oxigenase 2/genética , Ensaio de Imunoadsorção Enzimática , Retroalimentação Fisiológica , Gastrite/genética , Gastrite/metabolismo , Gastrite/patologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Gerbillinae , Infecções por Helicobacter/complicações , Helicobacter pylori , Humanos , Microscopia Confocal , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , RNA Interferente Pequeno , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiologiaRESUMO
The development of gastric cancer (GC) is a complex multistep process, including numerous genetic and epigenetic changes. CD24 is associated with enhanced invasiveness of GC and a poor prognosis. However, the mechanism by which CD24 induces GC progression remains poorly characterized. Here, we found that the expression of CD24 gradually increased in samples of normal gastric mucosa, non-atrophic chronic gastritis, chronic atrophic gastritis (CAG), CAG with intestinal metaplasia, dysplasia and GC. Moreover, the knockdown of CD24 induced significant levels of apoptosis in GC cells via the mitochondrial apoptotic pathway. CD24 may also promote cellular invasion and regulate the expression of E-cadherin, fibronectin and vitamin D receptor in GC cells. The activation of signal transducer and activator of transcription 3 (STAT3) may mediate CD24-induced GC survival and invasion in vitro. Furthermore, CD24-induced GC progression and STAT3 activation could also be detected in vivo and in clinical GC tissues samples. Taken together, our results indicate that CD24 mediates gastric carcinogenesis and may promote GC progression by suppressing apoptosis and promoting invasion, with the activation of STAT3 playing a critical role.
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Antígeno CD24/metabolismo , Carcinogênese/metabolismo , Fator de Transcrição STAT3/metabolismo , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Animais , Apoptose , Antígeno CD24/genética , Carcinogênese/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Doença Crônica , Progressão da Doença , Feminino , Gastrite/metabolismo , Xenoenxertos , Humanos , Mucosa Intestinal/metabolismo , Masculino , Metaplasia , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Transplante de Neoplasias , Neoplasias Gástricas/patologiaRESUMO
De novo organ regeneration is an excellent biological system for the study of fundamental questions regarding stem cell initiation, cell fate determination, and hormone signaling. Despite the general belief that auxin and cytokinin responses interact to regulate de novo organ regeneration, the molecular mechanisms underlying such a cross talk are little understood. Here, we show that spatiotemporal biosynthesis and polar transport resulted in local auxin distribution in Arabidopsis (Arabidopsis thaliana), which in turn determined the cytokinin response during de novo shoot regeneration. Genetic and pharmacological interference of auxin distribution disrupted the cytokinin response and ATP/ADP ISOPENTENYLTRANSFERASE5 (AtIPT5) expression, affecting stem cell initiation and meristem formation. Transcriptomic data suggested that AUXIN RESPONSE FACTOR3 (ARF3) mediated the auxin response during de novo organ regeneration. Indeed, mutations in ARF3 caused ectopic cytokinin biosynthesis via the misexpression of AtIPT5, and this disrupted organ regeneration. We further showed that ARF3 directly bound to the promoter of AtIPT5 and negatively regulated AtIPT5 expression. The results from this study thus revealed an auxin-cytokinin cross talk mechanism involving distinct intermediate signaling components required for de novo stem cell initiation and shed new light on the mechanisms of organogenesis in planta.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Citocininas/biossíntese , Proteínas de Ligação a DNA/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas Nucleares/metabolismo , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Transporte Biológico , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Genes Reporter , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Mutação , Proteínas Nucleares/genética , Células Vegetais/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismo , Técnicas do Sistema de Duplo-HíbridoRESUMO
The polycomb group protein enhancer of zeste homologue 2 (EZH2), which has histone methyltransferase (HMT) activity, is overexpressed in malignant tumours. However, the role of EZH2 in colorectal cancer (CRC) invasion is little known. Here we investigated the clinical significance, biological effects, and mechanisms of EZH2 signalling. Knockdown of EZH2 significantly reduced cell invasion and secretion of matrix metalloproteinases 2/9 (MMP2/9) in in vitro studies. Knockdown of EZH2 dramatically increased overall survival and decreased metastasis of lung in in vivo studies. Conversely, overexpression of EZH2 significantly increased lung metastasis and shortened overall survival when compared with control tumours. EZH2-induced CRC cell invasion may depend on down-regulation of vitamin D receptor (VDR), which is considered to be a marker of CRC invasion. EZH2 regulates the histone trimethylation of lysine 27 (H3K27me3) in the VDR promoter. Moreover, we found that STAT3 directly binds to the EZH2 promoter and regulates VDR down-regulation in CRC cells. Significant inverse correlations were observed between the expression of EZH2 and pSTAT3 and that of VDR in CRC tissues compared with normal tissue in patients. We show the role of EZH2 in CRC metastasis and identify VDR as a target gene of EZH2. EZH2 expression may be directly regulated by STAT3, and STAT3 may play an important role in EZH2-mediated VDR down-regulation in CRC. This pathway may provide potential targets in aggressive CRC.
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Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Complexo Repressor Polycomb 2/metabolismo , Receptores de Calcitriol/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Sequência de Bases , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Lisina/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Dados de Sequência Molecular , Invasividade Neoplásica , Complexo Repressor Polycomb 2/genética , Interferência de RNA , Receptores de Calcitriol/genética , Proteínas Recombinantes de Fusão , Fator de Transcrição STAT3/genética , Transdução de SinaisRESUMO
Background: One of the most prevalent hematological system cancers is acute myeloid leukemia (AML). Efferocytosis-related genes (ERGs) and N6-methyladenosine (m6A) have an important significance in the progression of cancer, and the metastasis of tumors. Methods: The AML-related data were collected from The Cancer Genome Atlas (TCGA; TCGA-AML) database and Gene Expression Omnibus (GEO; GSE9476, GSE71014, and GSE13159) database. The "limma" R package and Venn diagram were adopted to identify differentially expressed ERGs (DE-ERGs). The m6A related-DE-ERGs were obtained by Spearman analysis. Subsequently, univariate Cox and Least Absolute Shrinkage and Selection Operator (LASSO) were used to construct an m6A related-ERGs risk signature for AML patients. The possibility of immunotherapy for AML was explored. The pRRophetic package was adopted to calculate the IC50 of drugs for the treatment of AML. Finally, the expression of characterized genes was validated by quantitative reverse transcription-PCR (qRT-PCR). Results: Based on m6A related-DE-ERGs, a prognostic model with four characteristic genes (UCP2, DOCK1, SLC14A1, and SLC25A1) was constructed. The risk score of model was significantly associated with the immune microenvironment of AML, with four immune cell types, 14 immune checkpoints, 20 HLA family genes and, immunophenoscore (IPS) all showing differences between the high- and low-risk groups. A total of 56 drugs were predicted to differ between the two groups, of which Erlotinib, Dasatinib, BI.2536, and bortezomib have been reported to be associated with AML treatment. The qRT-PCR results showed that the expression trends of DOCK1, SLC14A1 and SLC25A1 were consistent with the bioinformatics analysis. Conclusion: In summary, 4 m6A related- ERGs were identified and the corresponding prognostic model was constructed for AML patients. This prognostic model effectively stratified the risk of AML patients.
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Neoplasias Hematológicas , Leucemia Mieloide Aguda , Humanos , Prognóstico , Genes Reguladores , Leucemia Mieloide Aguda/genética , Fatores de Transcrição , Microambiente TumoralRESUMO
A pair of new oxindole alkaloids, named macrophyllines C (1) and D (2), together with two known oxindole alkaloids isorhynchophylline (3) and corynoxine (4) were isolated from Uncaria macrophylla. Their structures were elucidated based on detailed spectroscopic analysis and by comparison with literature data. In addition, all the isolates were tested for their anti-HIV activities and cytotoxicities in C8166 cells and compounds 2-4 showed weak anti-HIV activities with EC50 values of 11.31 ± 3.29 µM, 18.77 ± 6.14 µM and 30.02 ± 3.73 µM, respectively.
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Alcaloides , Uncaria , Oxindóis/farmacologia , Alcaloides/química , Análise Espectral , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/químicaRESUMO
Association is the basic unit of plant community classification. Exploring the distribution of plant associations can help improve our understanding of biodiversity conservation. Different associations depend on different habitats and studying the association level is important for ecological restoration, regional ecological protection, regulating the ecological balance, and maintaining biodiversity. However, previous studies have only focused on suitable distribution areas for species and not on the distribution of plant associations. Larix gmelinii is a sensitive and abundant species that occurs along the southern margin of the Eurasian boreal forests, and its distribution is closely related to permafrost. In this study, 420 original plots of L. gmelinii forests were investigated. We used a Maxent model and the ArcGIS software to project the potential geographical distribution of L. gmelinii associations in the future (by 2050 and 2070) according to the climate scenarios RCP 2.6, RCP 4.5, and RCP 8.5. We used the multi-classification logistic regression analysis method to obtain the response of the suitable area change for the L. gmelinii alliance and associations to climate change under different climate scenarios. Results revealed that temperature is the most crucial factor affecting the distribution of L. gmelinii forests and most of its associations under different climate scenarios. Suitable areas for each association type are shrinking by varying degrees, especially due to habitat loss at high altitudes in special terrains. Different L. gmelinii associations should have different management measures based on the site conditions, composition structure, growth, development, and renewal succession trends. Subsequent research should consider data on biological factors to obtain more accurate prediction results.
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The development of male and female gametophytes is a prerequisite for successful propagation of angiosperms. The small GTPases RAN play fundamental roles in numerous cellular processes. Although RAN GTPases have been characterized in plants, their roles in cellular processes are far from understood. We report here that RAN GTPases in Arabidopsis are critical for gametophytic development. RAN1 loss-of-function showed no defects in gametophytic development likely due to redundancy. However, the expression of a dominant negative or constitutively active RAN1 resulted in gametophytic lethality. Genetic interference of RAN GTPases caused the arrest of pollen mitosis I and of mitosis of functional megaspores, implying a key role of properly regulated RAN activity in mitosis during gametophytic development.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , GTP Fosfo-Hidrolases/genética , Gametogênese , Regulação da Expressão Gênica de Plantas , Mitose/genética , MutaçãoRESUMO
BACKGROUND: It was still unclear whether the methodological reporting quality of randomized controlled trials (RCTs) in major hepato-gastroenterology journals improved after the Consolidated Standards of Reporting Trials (CONSORT) Statement was revised in 2001. METHODS: RCTs in five major hepato-gastroenterology journals published in 1998 or 2008 were retrieved from MEDLINE using a high sensitivity search method and their reporting quality of methodological details were evaluated based on the CONSORT Statement and Cochrane Handbook for Systematic Reviews of interventions. Changes of the methodological reporting quality between 2008 and 1998 were calculated by risk ratios with 95% confidence intervals. RESULTS: A total of 107 RCTs published in 2008 and 99 RCTs published in 1998 were found. Compared to those in 1998, the proportion of RCTs that reported sequence generation (RR, 5.70; 95%CI 3.11-10.42), allocation concealment (RR, 4.08; 95%CI 2.25-7.39), sample size calculation (RR, 3.83; 95%CI 2.10-6.98), incomplete outecome data addressed (RR, 1.81; 95%CI, 1.03-3.17), intention-to-treat analyses (RR, 3.04; 95%CI 1.72-5.39) increased in 2008. Blinding and intent-to-treat analysis were reported better in multi-center trials than in single-center trials. The reporting of allocation concealment and blinding were better in industry-sponsored trials than in public-funded trials. Compared with historical studies, the methodological reporting quality improved with time. CONCLUSION: Although the reporting of several important methodological aspects improved in 2008 compared with those published in 1998, which may indicate the researchers had increased awareness of and compliance with the revised CONSORT statement, some items were still reported badly. There is much room for future improvement.
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Gastroenterologia , Publicações Periódicas como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Projetos de Pesquisa , Relatório de Pesquisa/normasRESUMO
Respiratory viruses, including influenza virus, respiratory syncytial virus, coronavirus, etc., have seriously threatened the human health. For example, the outbreak of severe acute respiratory syndrome coronavirus, SARS, affected a large number of countries around the world. Marine organisms, which could produce secondary metabolites with novel structures and abundant biological activities, are an important source for seeking effective drugs against respiratory viruses. This report reviews marine natural products with activities against respiratory viruses, the emphasis of which was put on structures and antiviral activities of these natural products. This review has described 167 marinederived secondary metabolites with activities against respiratory viruses published from 1981 to 2019. Altogether 102 references are cited in this review article.
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Produtos Biológicos , Orthomyxoviridae , Preparações Farmacêuticas , Antivirais/farmacologia , Organismos Aquáticos , Produtos Biológicos/farmacologia , HumanosRESUMO
Tree ring data is of significance for reconstructing climate and predicting environmental dynamics. In order to accurately measure spacing and other parameters of Haloxylon ammodendron tree ring, we first assigned coordinate system to the scanned H. ammodendron disc PS images based on GIS, and then completed the H. ammodendron tree ring spacing measurement by using ENVI image classification software and GIS measuring tool. The measurement accuracy was proved by WinDENDRO tree ring analysis system. The results showed that there was no significant difference between those two methods (P=0.63), and that the difference of paired mean value was 0.87 µm, indicating that the measured results were accurate and reliable. The constructed method in this study could be used to measure the spacing of H. ammodendron tree ring, which lay the foundation for the automatic measurement of tree ring parameters such as area and perimeter. Our method could replace the current professional tree ring analysis system for some ring parameter measurement. The study would contribute to the dendroclimatology analysis and the investigation on age structure of H. ammodendron population.
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Amaranthaceae , Chenopodiaceae , Sistemas de Informação Geográfica , ÁrvoresRESUMO
Marine-derived fungi are well known as rich sources of bioactive natural products. Growing evidences indicated that indole alkaloids, isolated from a variety of marine-derived fungi, have attracted considerable attention for their diverse, challenging structural complexity and promising bioactivities, and therefore, indole alkaloids have potential to be pharmaceutical lead compounds. Systemic compilation of the relevant literature. In this review, we demonstrated a comprehensive overview of 431 new indole alkaloids from 21 genera of marine-derived fungi with an emphasis on their structures and bioactivities, covering literatures published during 1982-2019.
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OBJECTIVE: Fusobacterium nucleatum (F. nucleatum) has been reported to be enriched in patients with inflammatory bowel disease (IBD). This study aimed to explore the role of F. nucleatum in IBD and its pathogenic mechanism. METHODS: Several bacteria that have been reported to be associated with IBD or colorectal cancer were measured in the fecal samples of 91 patients with IBD and 43 healthy individuals. Mice with dextran sulfate sodium (DSS)-induced colitis and a Caco-2 cell line were used to explore the pathogenicity of F. nucleatum. Barrier damage was evaluated by a transmission electron microscope, the permeability of fluorescein isothiocyanate-dextran, transepithelial electrical resistance and immunofluorescence. Protein levels of the cell-cell junction and activation of the STAT3 signaling pathway were detected by immunohistochemistry and immunoblot. Cytokine secretion and T-cell differentiation were measured by quantitative real-time polymerase chain reaction and flow cytometry. RESULTS: F. nucleatum was significantly enriched in the feces of patients with IBD and its abundance correlated with disease activity. Administration of F. nucleatum markedly exacerbated colitis in a DSS mouse model. Mechanistically, F. nucleatum damaged epithelial integrity and increased permeability by regulating the expression and distribution of tight junction proteins zonula occludens-1 and occludin. Moreover, F. nucleatum promoted the secretion of cytokines (tumor necrosis factor-α, interferon-γ, interleukin [IL]-1ß, IL-6, and IL-17), activated the STAT3 signaling pathway, and induced CD4+ T cell proliferation and Th1 and Th17 subset differentiations. CONCLUSION: F. nucleatum can damage the intestinal barrier and induce aberrant inflammation, which exacerbates colitis.
Assuntos
Colite , Fusobacterium nucleatum , Inflamação , Mucosa Intestinal/patologia , Animais , Células CACO-2 , Colite/imunologia , Colite/microbiologia , Sulfato de Dextrana , Modelos Animais de Doenças , Fusobacterium nucleatum/patogenicidade , Humanos , Inflamação/microbiologia , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: To investigate the effects of combined infusion of mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) on lung injury after hematopoietic stem cell transplantation (HSCT). METHODS: The experiment was divided into normal control group, irradiation group, bone marrow cell transplantation group (BMT group), BMT+EPC group, BMT+MSC group and BMT+EPC+MSC group. The model of HSCT was established, on the 30th day after transplantation, the mice were sacrificed. Then lung tissue was taken for testing. The mRNA expression levels of VEGF, IL-18, IL-12b were detected by RT-PCR, and protein expression level of NLRP3 was detected by Western blot. The expression of MPO and CD146 was observed by immunohistochemistry assay. RESULTS: The expression level of VEGF gene in BMT+EPC+MSC group was significantly higher than that in other groups (Pï¼0.01). The expression level of IL-18 and IL-12b gene was the highest in BMT group and the lowest in BMT+EPC+MSC group, and the difference was statistically significant (Pï¼0.05). HSCT could increase the expression of NLRP3 protein, and the BMT+EPC+MSC could significantly reduce the level of NLRP3 protein in lung cells, tending to normal. Compared with normal tissues, the BMT+EPC+MSC could improve the lung tissue structure more effectively, the expression of MPO positive cells was lower, and the expression of VEGF positive cells was higher. CONCLUSIONS: The combined infusion of MSC and EPC can promote capillary regeneration, alleviate inflammation and promote lung repair after HSCT, which is superior to single EPC or MSC infusion.