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1.
BMC Microbiol ; 24(1): 294, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39107680

RESUMEN

The colonization of alien plants in new habitats is typically facilitated by microorganisms present in the soil environment. However, the diversity and structure of the archaeal, bacterial, and fungal communities in the latitudinal spread of alien plants remain unclear. In this study, the rhizosphere and bulk soil of Chromolaena odorata were collected from five latitudes in Pu' er city, Yunnan Province, followed by amplicon sequencing of the soil archaeal, bacterial, and fungal communities. Alpha and beta diversity results revealed that the richness indices and the structures of the archaeal, bacterial, and fungal communities significantly differed along the latitudinal gradient. Additionally, significant differences were observed in the bacterial Shannon index, as well as in the structures of the bacterial and fungal communities between the rhizosphere and bulk soils. Due to the small spatial scale, trends of latitudinal variation in the archaeal, bacterial, and fungal communities were not pronounced. Total potassium, total phosphorus, available nitrogen, available potassium and total nitrogen were the important driving factors affecting the soil microbial community structure. Compared with those in bulk soil, co-occurrence networks in rhizosphere microbial networks presented lower complexity but greater modularity and positive connections. Among the main functional fungi, arbuscular mycorrhizae and soil saprotrophs were more abundant in the bulk soil. The significant differences in the soil microbes between rhizosphere and bulk soils further underscore the impact of C. odorata invasion on soil environments. The significant differences in the soil microbiota along latitudinal gradients, along with specific driving factors, demonstrate distinct nutrient preferences among archaea, bacteria, and fungi and indicate complex microbial responses to soil nutrient elements following the invasion of C. odorata.


Asunto(s)
Archaea , Bacterias , Chromolaena , Hongos , Microbiota , Rizosfera , Microbiología del Suelo , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Hongos/clasificación , Hongos/genética , Hongos/aislamiento & purificación , Chromolaena/microbiología , Archaea/clasificación , Archaea/genética , Archaea/aislamiento & purificación , China , Especies Introducidas , Biodiversidad , Suelo/química , Raíces de Plantas/microbiología , Filogenia
2.
Am J Bot ; 109(6): 910-921, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35471767

RESUMEN

PREMISE: Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species. METHODS: We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden. RESULTS: Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast-return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast-return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots). CONCLUSIONS: Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants.


Asunto(s)
Sequías , Herbivoria , Especies Introducidas , Hojas de la Planta/fisiología , Plantas
3.
Oecologia ; 192(1): 105-118, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31792607

RESUMEN

Multiple mechanisms may act synergistically to promote success of invasive plants. Here, we tested the roles of three non-mutually exclusive mechanisms-founder effects, post-introduction evolution and phenotypic plasticity-in promoting invasion of Chromolaena odorata. We performed a common garden experiment to investigate phenotypic diversification and phenotypic plasticity of the genetically impoverished invader in response to two rainfall treatments (ambient and 50% rainfall). We used ancestor-descendant comparisons to determine post-introduction evolution and the QST-FST approach to estimate past selection on phenotypic traits. We found that eight traits differed significantly between plants from the invasive versus native ranges, for two of which founder effects can be inferred and for six of which post-introduction evolution can be inferred. The invader experienced strong diversifying selection in the invasive range and showed clinal variations in six traits along water and/or temperature gradients. These clinal variations are likely attributed to post-introduction evolution rather than multiple introductions of pre-adapted genotypes, as most of the clinal variations were absent or in opposite directions from those for native populations. Compared with populations, rainfall treatments explained only small proportions of total variations in all studied traits for plants from both ranges, highlighting the importance of heritable phenotypic differentiation. In addition, phenotypic plasticity was similar for plants from both ranges although neutral genetic diversity was much lower for plants from the invasive range. Our results showed that founder effects, post-introduction evolution and phenotypic plasticity may function synergistically in promoting invasion success of C. odorata.


Asunto(s)
Evolución Biológica , Efecto Fundador , Adaptación Fisiológica , Especies Introducidas , Fenotipo
4.
New Phytol ; 222(2): 701-707, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30394547

RESUMEN

Contents Summary 701 I. Introduction 701 II. Why we need an explicitly evolutionary perspective 702 III. A case study invasion experiment 702 IV. The way forward 703 V. Conclusions 705 Acknowledgements 706 References 706 SUMMARY: Comparing models of trait evolution might generate new insights into the role of evolutionary history in biological invasions. Assumptions underlying Darwin's naturalization conundrum suggest that close relatives are functionally similar. However, newer work is suggesting more complex relationships between phylogenetic and functional distance. We present an example in which communities of close relatives are functionally divergent in leaf traits and have greater invader biomass. Such an approach leads to new questions, such as: When might selection lead to divergence between close relatives? For example, a history of sympatry might correspond with divergence. We suggest that moving beyond a simplistic version of Darwin's naturalization conundrum as alternative hypotheses will lead to a more nuanced view on how evolution has shaped biological invasions.


Asunto(s)
Evolución Biológica , Especies Introducidas , Modelos Biológicos , Filogenia
5.
Ecol Lett ; 21(8): 1211-1220, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29808558

RESUMEN

Biotic resistance may influence invasion success; however, the relative roles of species richness, functional or phylogenetic distance in predicting invasion success are not fully understood. We used biomass fraction of Chromolaena odorata, an invasive species in tropical and subtropical areas, as a measure of 'invasion success' in a series of artificial communities varying in species richness. Communities were constructed using species from Mexico (native range) or China (non-native range). We found strong evidence of biotic resistance: species richness and community biomass were negatively related with invasion success; invader biomass was greater in plant communities from China than from Mexico. Harvesting time had a greater effect on invasion success in plant communities from China than on those from Mexico. Functional and phylogenetic distances both correlated with invasion success and more functionally distant communities were more easily invaded. The effects of plant-soil fungi and plant allelochemical interactions on invasion success were species-specific.


Asunto(s)
Chromolaena , Filogenia , Biomasa , China , Especies Introducidas
6.
Biol Chem ; 398(7): 785-792, 2017 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-28002023

RESUMEN

Valproic acid (VPA) has been suggested to be a histone deacetylase inhibitor (HDACI). Our present study revealed that VPA at 1 mm, which had no effect on cell proliferation, can significantly increase the sensitivity of non-small cell lung cancer (NSCLC) cells to cisplatin (DDP). VPA treatment markedly decreased the mRNA and protein levels of ABCA1, while had no significant effect on ABCA3, ABCA7 or ABCB10. Luciferase reporter assays showed that VPA can decrease the ABCA1 promoter activity in both A549 and H358 cells. VPA treatment also decreased the phosphorylation of SP1, which can bind to -100 and -166 bp in the promoter of ABCA1. While the phosphorylation of c-Fos and c-Jun were not changed in VPA treated NSCLC cells. Over expression of HDAC2 attenuated VPA induced down regulation of ABCA1 mRNA expression and promoter activities. Over expression of HDAC2 also attenuated VPA induced DDP sensitivity of NSCLC cells. These data revealed that VPA can increase the DDP sensitivity of NSCLC cells via down regulation of ABCA1 through HDAC2/SP1 signals. It suggested that combination of VPA and anticancer drugs such as DDP might be great helpful for treatment of NSCLC patients.


Asunto(s)
Transportador 1 de Casete de Unión a ATP/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Cisplatino/farmacología , Regulación hacia Abajo/efectos de los fármacos , Histona Desacetilasa 2/metabolismo , Neoplasias Pulmonares/patología , Ácido Valproico/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Sinergismo Farmacológico , Histona Desacetilasa 2/genética , Humanos , Factor de Transcripción Sp1/metabolismo , Transcripción Genética/efectos de los fármacos
7.
Cancer Cell Int ; 17: 64, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28615992

RESUMEN

BACKGROUND: Recent studies have verified that long noncoding RNAs (lncRNAs) involved in many biological functions and play crucial roles in human cancers progression, the study aimed to detect the association between long non-coding RNA HOXA11-AS and epithelial-mesenchymal transition (EMT) process in non-small cell lung cancer (NSCLC). METHODS: The lncRNA HOXA11-AS expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) assays in 78 paired of tumor tissue and adjacent normal tissue samples in NSCLC patients. Kaplan-Meier survival curves and log-rank test was used to examine the association between lncRNA HOXA11-AS expression and the over survival time in NSCLC patients. Transwell invasion assay was performed to detect the cell invasion ability. QRT-PCR and western-blot analysis detected the mRNA and protein expression of EMT related transcription factors ZEB1/ZEB2, Snail1/2 and EMT marker E-cadherin and N-cadherin in NSCLC cells. RIP and Chromatin immunoprecipitation assays were performed to analyze the association between lncRNA HOXA11-AS and miR-200b expression in NSCLC cells. RESULTS: The lncRNA HOXA11-AS expression levels were significantly higher in NSCLC tissues compared with adjacent normal tissues and higher HOXA11-AS expression levels had a poor prognosis in NSCLC patients. Furthermore, knockdown of lncRNA HOXA11-AS in A549 and H1299 cells dramatically inhibited cell invasive abilities. Besides, the transcription levels and protein levels of EMT related transcription factors ZEB1/ZEB2, Snail1/2, and EMT maker N-cadherin were down-regulated after lncRNA HOXA11-AS was knocked down, but the mRNA and protein expression levels of EMT maker E-cadherin was increasing in A549 and H1299 cells. The mechanistic findings showed demonstrated that HOXA11-AS interacted with EZH2 and DNMT1 and recruited them to the miR-200b promoter regions to repress miR-200b expression in NSCLC cells, which promoted cell EMT in NSCLC. CONCLUSIONS: Our results showed that up-regulation of lncRNA HOXA11-AS predicted a poor prognosis and lncRNA HOXA11-AS promoted cell epithelial-mesenchymal transition (EMT) by inhibiting miR-200b expression in NSCLC.

8.
New Phytol ; 205(3): 1350-1359, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25367824

RESUMEN

The evolution of increased competitive ability (EICA) hypothesis and the novel weapons hypothesis (NWH) are two non-mutually exclusive mechanisms for exotic plant invasions, but few studies have simultaneously tested these hypotheses. Here we aimed to integrate them in the context of Chromolaena odorata invasion. We conducted two common garden experiments in order to test the EICA hypothesis, and two laboratory experiments in order to test the NWH. In common conditions, C. odorata plants from the nonnative range were better competitors but not larger than plants from the native range, either with or without the experimental manipulation of consumers. Chromolaena odorata plants from the nonnative range were more poorly defended against aboveground herbivores but better defended against soil-borne enemies. Chromolaena odorata plants from the nonnative range produced more odoratin (Eupatorium) (a unique compound of C. odorata with both allelopathic and defensive activities) and elicited stronger allelopathic effects on species native to China, the nonnative range of the invader, than on natives of Mexico, the native range of the invader. Our results suggest that invasive plants may evolve increased competitive ability after being introduced by increasing the production of novel allelochemicals, potentially in response to naïve competitors and new enemy regimes.


Asunto(s)
Alelopatía , Evolución Biológica , Chromolaena/fisiología , Especies Introducidas , Modelos Biológicos , Clima Tropical , Biomasa , Chromolaena/crecimiento & desarrollo , Geografía , Sesquiterpenos/análisis , Sesquiterpenos/química
9.
Ann Bot ; 116(1): 113-22, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26050068

RESUMEN

BACKGROUND AND AIMS: The advantage of clonal integration (resource sharing between connected ramets of clonal plants) varies and a higher degree of integration is expected in more stressful and/or more heterogeneous habitats. Clonal facultative epiphytes occur in both forest canopies (epiphytic habitats) and forest understories (terrestrial habitats). Because environmental conditions, especially water and nutrients, are more stressful and heterogeneous in the canopy than in the understorey, this study hypothesizes that clonal integration is more important for facultative epiphytes in epiphytic habitats than in terrestrial habitats. METHODS: In a field experiment, an examination was made of the effects of rhizome connection (connected vs. disconnected, i.e. with vs. without clonal integration) on survival and growth of single ramets, both young and old, of the facultative epiphytic rhizomatous fern Selliguea griffithiana (Polypodiaceae) in both epiphytic and terrestrial habitats. In another field experiment, the effects of rhizome connection on performance of ramets were tested in small (10 × 10 cm(2)) and large (20 × 20 cm(2)) plots in both epiphytic and terrestrial habitats. KEY RESULTS: Rhizome disconnection significantly decreased survival and growth of S. griffithiana in both experiments. The effects of rhizome disconnection on survival of single ramets and on ramet number and growth in plots were greater in epiphytic habitats than in terrestrial habitats. CONCLUSIONS: Clonal integration contributes greatly to performance of facultative epiphytic ferns, and the effects were more important in forest canopies than in forest understories. The results therefore support the hypothesis that natural selection favours genotypes with a higher degree of integration in more stressful and heterogeneous environments.


Asunto(s)
Helechos/citología , Helechos/crecimiento & desarrollo , Bosques , Análisis de Varianza , Biomasa , Células Clonales , Ecosistema
10.
Clin Lab ; 61(3-4): 337-44, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25975001

RESUMEN

BACKGROUND: The objective of this observational study was to determine whether there is an association between extubation success and uric acid in chronic obstructive pulmonary disease patients with mechanical ventilation admitted to the intensive care units, and identify the risk markers for extubation success in COPD patients with mechanical ventilation. METHODS: Consecutive COPD patients with intubation were screened at baseline. The study included patients on mechanical ventilation (MV) for over 12 hours and who, in the process of weaning, were subjected to low-level pressure support. Exclusion criteria were age under 18 years, ventilation via tracheotomy, and patients failing to cooperate for different reasons. The final study population consisted of 106 patients. Demographic, clinical, laboratory, and mechanical ventilation parameters were carefully recorded. Logistic regression was used for the multivariate analysis of independent risk factors. RESULTS: Uric acid on admission, duration of mechanical ventilation, pressure support ventilation, and APACHE II score on admission were significantly higher in COPD patients with extubation failure than in those with extubation success (p < 0.05), but lower tidal volume before weaning was observed in COPD patients with extubation failure. Among these patients, multiple logistic analyses indicated the independent risk factors for extubation success in the COPD subjects included serum uric acid level, APACHE II score on admission, and duration of mechanical ventilation. The diagnosis analysis showed that higher uric acid level and APACHE II score on admission and longer duration of mechanical ventilation had a significant ability to reflect extubation success in the COPD patients with respiratory failure. CONCLUSIONS: The novel finding of this study is that the extubation failure in COPD patients with respiratory failure is strongly related to serum uric acid level, APACHE II score on admission, and duration of mechanical ventilation. These results might be helpful for selecting the best time to remove the tracheal intubation and improving extubation success rate in COPD patients with respiratory failure.


Asunto(s)
Extubación Traqueal , Biomarcadores/sangre , Enfermedad Pulmonar Obstructiva Crónica/sangre , Ácido Úrico/sangre , Anciano , Técnicas de Laboratorio Clínico , Cuidados Críticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Presión , Estudios Prospectivos , Curva ROC , Análisis de Regresión , Respiración Artificial , Factores de Riesgo , Índice de Severidad de la Enfermedad , Traqueotomía
11.
BMC Infect Dis ; 14: 523, 2014 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-25267108

RESUMEN

BACKGROUND: Clostridium difficile carriage has been considered as a potential source for the deadly infection, but its role in cancer patients is still unclear. We aimed to identify the clinical and immunological factors that are related to C. difficile carriage in Chinese cancer patients. METHODS: A total of 400 stool samples were collected from cancer patients who received chemotherapy in three hospitals of eastern China. Bacterial genomic DNA was extracted and two toxin genes (tcdA and tcdB) were detected. PCR ribotyping was performed using capillary gel electrophoresis. Concentrations of prostaglandin E2 (PGE2), transforming growth factor beta (TGF-ß) and interleukin-10 (IL-10) were measured using enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: Eighty-two (20.5%) samples were confirmed to be C. difficile-positive and positive for tpi, tcdA, and tcdB genes. The C. difficile-positive rates in patients with diarrhea and no diarrhea were 35% and 19.7%, respectively (p = 0.09). Patients who were younger than 50 years old and were hospitalized for at least 10 days had a C. difficile-positive rate as high as 35%. In contrast, patients who were older than 50 years old and were hospitalized for less than 10 days had a C. difficile-positive rate of only 12.7% (p = 0.0009). No association was found between C. difficile carriage and chemotherapy regimen, antibiotic drug use, or immunosuppressive mediators, such as prostaglandin E2 (PGE2), transforming growth factor beta (TGF-ß), or interleukin-10 (IL-10). Twelve ribotypes of C. difficile were identified, but none of them belonged to ribotype 027. CONCLUSIONS: We conclude that younger patients and those with longer hospitalization stays may be more prone to C. difficile carriage. Studies of larger populations are warranted to clarify the exact role of C. difficile carriage in hospitalized cancer patients in China.


Asunto(s)
Portador Sano/epidemiología , Clostridioides difficile/genética , Diarrea/epidemiología , Enterocolitis Seudomembranosa/epidemiología , Neoplasias/epidemiología , Toxinas Bacterianas/genética , Portador Sano/diagnóstico , Portador Sano/microbiología , China , ADN Bacteriano/genética , Diarrea/diagnóstico , Diarrea/microbiología , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/microbiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Hospitalización , Humanos , Interleucina-10/genética , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular , Neoplasias/microbiología , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Ribotipificación
12.
Oecologia ; 174(4): 1205-14, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24326694

RESUMEN

Invasive plants generally escape from specialist herbivores of their native ranges but may experience serious damage from generalists. As a result, invasive plants may evolve increased resistance to generalists and tolerance to damage. To test these hypotheses, we carried out a common garden experiment comparing 15 invasive populations with 13 native populations of Chromolaena odorata, including putative source populations identified with molecular methods and binary choice feeding experiments using three generalist herbivores. Plants from invasive populations of C. odorata had both higher resistance to three generalists and higher tolerance to simulated herbivory (shoot removal) than plants from native populations. The higher resistance of plants from invasive populations was associated with higher leaf C content and densities of leaf trichomes and glandular scales, and lower leaf N and water contents. Growth costs were detected for tolerance but not for resistance, and plants from invasive populations of C. odorata showed lower growth costs of tolerance. Our results suggest that invasive plants may evolve to increase both resistance to generalists and tolerance to damage in introduced ranges, especially when the defense traits have low or no fitness costs. Greater defenses in invasive populations may facilitate invasion by C. odorata by reducing generalist impacts and increasing compensatory growth after damage has occurred.


Asunto(s)
Asteraceae/fisiología , Evolución Biológica , Herbivoria , Especies Introducidas , Animales , Asteraceae/genética , Hojas de la Planta/fisiología
13.
New Phytol ; 197(3): 979-988, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23252450

RESUMEN

There are many non-mutually exclusive mechanisms for exotic invasions but few studies have concurrently tested more than one hypothesis for the same species. Here, we tested the evolution of increased competitive ability (EICA) hypothesis in two common garden experiments in which Chromolaena odorata plants originating from native and nonnative ranges were grown in competition with natives from each range, and the novel weapons hypothesis in laboratory experiments with leachates from C. odorata. Compared with conspecifics originating from the native range, C. odorata plants from the nonnative range were stronger competitors at high nutrient concentrations in the nonnative range in China and experienced far more herbivore damage in the native range in Mexico. In both China and Mexico, C. odorata was more suppressed by species native to Mexico than by species native to China. Species native to China were much more inhibited by leaf extracts from C. odorata than species from Mexico, and this difference in allelopathic effects may provide a possible explanation for the biogeographic differences in competitive ability. Our results indicate that EICA, innate competitive advantages, and novel biochemical weapons may act in concert to promote invasion by C. odorata, and emphasize the importance of exploring multiple, non-mutually exclusive mechanisms for invasions.


Asunto(s)
Chromolaena/fisiología , Especies Introducidas , Adaptación Fisiológica , China , Geografía , Herbivoria , México , Dinámica Poblacional , Estrés Fisiológico
14.
Planta ; 236(4): 1205-13, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22684510

RESUMEN

Global environmental change and ongoing biological invasions are the two prominent ecological issues threatening biodiversity worldwide, and investigations of their interaction will aid to predict plant invasions and inform better management strategies in the future. In this study, invasive Eupatorium adenophorum and native congener E. stoechadosmum were compared at ambient and elevated atmospheric carbon dioxide (CO(2)) concentrations combined with three levels of nitrogen (N; reduced, control and increased) in terms of growth, energy gain, and cost. Compared with E. stoechadosmum, E. adenophorum adopted a quicker-return energy-use strategy, i.e. higher photosynthetic energy-use efficiency and shorter payback time. Lower leaf mass per area may be a pivotal trait for the invader, which contributed to an increased N allocation to Rubisco at the expense of cell walls and therefore to higher photosynthetic energy gain. CO(2) enrichment and N deposition synergistically promoted plant growth and influenced some related ecophysiological traits, and the synergistic effects were greater for the invader than for the native congener. Reducing N availability by applying sugar eliminated the advantages of the invader over its native congener at both CO(2) levels. Our results indicate that CO(2) enrichment and N deposition may exacerbate E. adenophorum's invasion in the future, and manipulating environmental resources such as N availability may be a feasible tool for managing invasion impacts of E. adenophorum.


Asunto(s)
Ageratina/efectos de los fármacos , Dióxido de Carbono/farmacología , Eupatorium/efectos de los fármacos , Nitrógeno/farmacología , Fotosíntesis/efectos de los fármacos , Ageratina/crecimiento & desarrollo , Ageratina/fisiología , Biomasa , Pared Celular/metabolismo , China , Ecología , Eupatorium/crecimiento & desarrollo , Eupatorium/fisiología , Especies Introducidas , Modelos Teóricos , Fenotipo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Ribulosa-Bifosfato Carboxilasa/metabolismo , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Plantones/fisiología
15.
Proc Natl Acad Sci U S A ; 106(6): 1853-6, 2009 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-19171910

RESUMEN

Many studies have shown that individuals from invasive populations of many different plant species grow larger than individuals from native populations and that this difference has a genetic basis. This increased vigor in invasive populations is thought to be due to life history tradeoffs, in which selection favors the loss of costly defense traits, thereby freeing resources that can be devoted to increased growth or fecundity. Despite the theoretical importance of such allocation shifts for invasions, there have been no efforts to understand apparent evolutionary shifts in defense-growth allocation mechanistically. Reallocation of nitrogen (N) to photosynthesis is likely to play a crucial role in any growth increase; however, no study has been conducted to explore potential evolutionary changes in N allocation of introduced plants. Here, we show that introduced Ageratina adenophora, a noxious invasive plant throughout the subtropics, appears to have evolved increased N allocation to photosynthesis (growth) and reduced allocation to cell walls, resulting in poorer structural defenses. Our results provide a potential mechanism behind the commonly observed and genetically based increase in plant growth and vigor when they are introduced to new ranges.


Asunto(s)
Ageratina/metabolismo , Evolución Biológica , Pared Celular/química , Ecosistema , Nitrógeno/metabolismo , Fotosíntesis , Ageratina/genética , Ageratina/crecimiento & desarrollo , Desarrollo de la Planta , Plantas/genética , Plantas/metabolismo
16.
Physiol Plant ; 2011 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-21645002

RESUMEN

Both global change and biological invasions threaten biodiversity worldwide. However, their interactions and related mechanisms are still not well elucidated. To elucidate potential traits contributing to invasiveness and whether ongoing increase in CO(2) aggravates invasions, noxious invasive Eupatorium adenophorum and native E. japonicum and E. chinensis were compared under ambient and doubled atmospheric CO(2) concentrations in terms of growth, biomass allocation, morphology, and physiology. The invader had consistently higher leaf mass fraction and specific leaf area than the natives, contributing to a higher leaf area ratio, and therefore to faster growth and invasiveness. The higher leaf mass fraction of the invader was associated with lower total root mass fraction. The invader allocated a higher fraction of leaf nitrogen (N) to photosynthesis, contributing to higher area-based N content in photosynthetic apparatus, photosynthetic rate, nitrogen- and water-use efficiencies, and invasiveness. CO(2) enrichment increased growth of all studied plants by increasing actual photosynthesis, although it decreased photosynthetic capacities due to decreased area-based leaf and photosynthetic N contents. Responses of the invasive and native plants to elevated CO(2) were not significantly different, indicating that the ongoing increase in CO(2) may not exacerbate biological invasions, inconsistent with the prevailing results in references. The difference may be associated with the fact that almost all previous studies compared phylogenetically unrelated invasive and native plants. More comparative studies of sympatric, related invasive and native plants are needed to elucidate whether CO(2) enrichment facilitates invasions.

17.
Front Oncol ; 9: 894, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31620359

RESUMEN

Exosomes are small membranous vesicles that contain proteins, lipids, genetic material, and metabolites with abundant information from parental cells. Exosomes carry and deliver bioactive contents that can reprogram the functions of recipient cells and modulate the tumor microenvironment to induce pathological events through cell-to-cell communication and signal transduction. Tumor-derived exosomes (TDEs) in head and neck squamous cell carcinoma (HNSCC) are involved in most aspects of cancer initiation, invasion, progression, immunoregulation, therapeutic applications, and treatment resistance. In addition, HNSCC-derived exosomes can be used to obtain information on diagnostic and therapeutic biomarkers in circulating blood and saliva. Currently, the biology, mechanisms, and applications of TDEs in HNSCC are still unclear, and further research is required. In this review, we discuss various aspects of exosome biology, including exosomal components, exosomal biomarkers, and molecular mechanisms involved in immunoregulation, cancer metastasis, and therapy resistance. We also describe recent applications to update our understanding of exosomes in HNSCC.

18.
Biomed Pharmacother ; 96: 153-164, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28982084

RESUMEN

Increasing studies have indicated that the dysregulated microRNAs (miRNAs) are associated with tumorigenesis, development and even the poor prognosis of a variety of tumors, including the non-small-cell lung cancer (NSCLC). Here in our study, we found that miRNA-484 was expressed highly in NSCLC clinical tumor samples in comparison to the matched adjacent tissues. In addition, high and low expression of miRNA-484 was observed in NSCLC cell lines and lung normal cells, respectively. Furthermore, the capability of migration and proliferation changed accompanied with the altered expression of miR-484 in NSCLC. Apoptotic protease activating factor-1 (APAF-1), frequently down-regulated in a number of types of cancer, was found to be reduced in NSCLC tissue samples or NSCLC cell lines along with high expression of miR-484, which were inversely expressed in Apaf-1 over-expressed tissues or cells. Moreover, miR-484 triggered the migration and proliferation, and simultaneously reduced the cleavage of poly (ADP-ribose) polymerase-2 (PARP-2) and Caspase-3 of A549 cells, which could be suppressed by the improvement of Apaf-1. And the inhibition of Apaf-1 could reverse the function caused by miR-484 in A549 cells, suggesting that Apaf-1 was targeted by miR-484 directly and it could be acted as a potential therapeutic target against NSCLC. In conclusion, the reductive Apaf-1 regulated by miR-484 accelerated the NSCLC cell progression associated with the inhibition of apoptosis via down-regulating Caspase-3 and PARP cleavage.


Asunto(s)
Apoptosis/fisiología , Factor Apoptótico 1 Activador de Proteasas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Progresión de la Enfermedad , Neoplasias Pulmonares/metabolismo , MicroARNs/biosíntesis , Células A549 , Animales , Apoptosis/efectos de los fármacos , Factor Apoptótico 1 Activador de Proteasas/antagonistas & inhibidores , Carcinoma de Pulmón de Células no Pequeñas/genética , Humanos , Neoplasias Pulmonares/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/administración & dosificación , MicroARNs/genética , Ratas , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
19.
Zhonghua Jie He He Hu Xi Za Zhi ; 29(2): 92-5, 2006 Feb.
Artículo en Zh | MEDLINE | ID: mdl-16677449

RESUMEN

OBJECTIVE: The purpose of this study was to describe the approaches to the diagnosis and the treatment of chronic necrotizing pulmonary aspergillosis (CNPA). METHODS: The study included 8 patients with CNPA confirmed by histopathological studies. The patients were admitted to the First Affiliated Hospital of College of Medicine of Zhejiang University during 2000-2004. The clinical data were analyzed, and related literature was reviewed. The clinical, radiological and pathological characteristics, and the approaches to the diagnosis and the treatment were described. RESULTS: CNPA was a rare form of pulmonary aspergillosis. Common presentations included productive cough (8/8), haemoptysis (7/8) and constitutional symptoms (5/8). Radiographically, the air crescent sign was suggestive of the diagnosis, which was found in 4 patients. Consolidation was also common in the other 4 cases. The histological feature of CNPA included the presence of tissue invasion by Aspergillus, tissue necrosis and granulomatous inflammation. CONCLUSIONS: The clinical manifestations of CNPA are non-specific. Radiography plays a pivotal role in the diagnosis of CNPA. Treatment with antifungal medications is indicated once the diagnosis is made. Pulmonary resection should be considered when patients have prolonged illness or frequent haemoptysis.


Asunto(s)
Aspergilosis Pulmonar Invasiva/diagnóstico , Aspergilosis Pulmonar Invasiva/tratamiento farmacológico , Adulto , Anciano , Antifúngicos/uso terapéutico , Aspergillus , Infecciones Comunitarias Adquiridas , Femenino , Humanos , Pulmón/patología , Masculino , Persona de Mediana Edad , Adulto Joven
20.
Respir Med ; 121: 48-58, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27888992

RESUMEN

BACKGROUND: Obesity worsens asthma control partly through enhanced airway neutrophilia, altered lung mechanics and comorbidities, including obstructive sleep apnea syndrome, gastroesophageal reflux disease and depression. Although controversial, obesity may also cause poorer outcomes in acute asthma. IL-17 is associated with neutrophilic inflammation, steroid resistance and severe asthma, but its importance in the association between asthma and obesity is unknown. OBJECTIVE: To investigate the role of IL-17 in obese asthma in both acute and stable settings. METHODS: Both stable (n = 177) and acute (n = 78) asthmatics were recruited and categorized into lean (n = 77 and 39 respectively), overweight (n = 41 and 17 respectively) and obese (n = 59 and 22 respectively) groups and compared for clinical characteristics, including sputum and plasma IL-17 protein concentrations, sputum cellularity, spirometry and comorbidities. Correlations of IL-17 expression with other measures were explored. RESULTS: In stable subjects, airway neutrophilia and IL-17 concentrations were most prominent in the obese, and correlated positively with each other. Significant increase in plasma IL-17 levels was also noted and associated with elevated depressive symptoms in obesity. In acute asthma, IL-17 expression, like most other clinical measures, was similar among lean, overweight and obese groups, but was higher in acute versus stable asthma subjects, with sputum IL-17 correlating positively with sputum neutrophils and negatively with FEV1 and plasma IL-17 showing a positive connection to airway eosinophilia during exacerbation. CONCLUSIONS: IL-17 contributes to worse disease control in obese asthma through enhancing airway neutrophilia and depression, and may implicate in asthma exacerbations. Effects of adiposity on acute asthma remain uncertain.


Asunto(s)
Asma/inmunología , Interleucina-17/análisis , Obesidad/inmunología , Esputo/inmunología , Enfermedad Aguda , Adulto , Asma/complicaciones , Índice de Masa Corporal , Depresión/inmunología , Femenino , Humanos , Interleucina-17/sangre , Masculino , Persona de Mediana Edad , Neutrófilos/patología , Obesidad/complicaciones , Sobrepeso/complicaciones , Sobrepeso/inmunología , Esputo/citología , Delgadez/inmunología
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