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1.
Cell ; 177(7): 1903-1914.e14, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31031007

RESUMO

Xenograft cell transplantation into immunodeficient mice has become the gold standard for assessing pre-clinical efficacy of cancer drugs, yet direct visualization of single-cell phenotypes is difficult. Here, we report an optically-clear prkdc-/-, il2rga-/- zebrafish that lacks adaptive and natural killer immune cells, can engraft a wide array of human cancers at 37°C, and permits the dynamic visualization of single engrafted cells. For example, photoconversion cell-lineage tracing identified migratory and proliferative cell states in human rhabdomyosarcoma, a pediatric cancer of muscle. Additional experiments identified the preclinical efficacy of combination olaparib PARP inhibitor and temozolomide DNA-damaging agent as an effective therapy for rhabdomyosarcoma and visualized therapeutic responses using a four-color FUCCI cell-cycle fluorescent reporter. These experiments identified that combination treatment arrested rhabdomyosarcoma cells in the G2 cell cycle prior to induction of apoptosis. Finally, patient-derived xenografts could be engrafted into our model, opening new avenues for developing personalized therapeutic approaches in the future.


Assuntos
Animais Geneticamente Modificados/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Musculares , Rabdomiossarcoma , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/imunologia , Feminino , Xenoenxertos , Humanos , Células K562 , Masculino , Neoplasias Musculares/tratamento farmacológico , Neoplasias Musculares/imunologia , Neoplasias Musculares/metabolismo , Neoplasias Musculares/patologia , Transplante de Neoplasias , Ftalazinas/farmacologia , Piperazinas/farmacologia , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/imunologia , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/patologia , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra/genética , Peixe-Zebra/imunologia
2.
Blood ; 140(17): 1891-1906, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-35544598

RESUMO

Relapse and refractory T-cell acute lymphoblastic leukemia (T-ALL) has a poor prognosis, and new combination therapies are sorely needed. Here, we used an ex vivo high-throughput screening platform to identify drug combinations that kill zebrafish T-ALL and then validated top drug combinations for preclinical efficacy in human disease. This work uncovered potent drug synergies between AKT/mTORC1 (mammalian target of rapamycin complex 1) inhibitors and the general tyrosine kinase inhibitor dasatinib. Importantly, these same drug combinations effectively killed a subset of relapse and dexamethasone-resistant zebrafish T-ALL. Clinical trials are currently underway using the combination of mTORC1 inhibitor temsirolimus and dasatinib in other pediatric cancer indications, leading us to prioritize this therapy for preclinical testing. This combination effectively curbed T-ALL growth in human cell lines and primary human T-ALL and was well tolerated and effective in suppressing leukemia growth in patient-derived xenografts (PDX) grown in mice. Mechanistically, dasatinib inhibited phosphorylation and activation of the lymphocyte-specific protein tyrosine kinase (LCK) to blunt the T-cell receptor (TCR) signaling pathway, and when complexed with mTORC1 inhibition, induced potent T-ALL cell killing through reducing MCL-1 protein expression. In total, our work uncovered unexpected roles for the LCK kinase and its regulation of downstream TCR signaling in suppressing apoptosis and driving continued leukemia growth. Analysis of a wide array of primary human T-ALLs and PDXs grown in mice suggest that combination of temsirolimus and dasatinib treatment will be efficacious for a large fraction of human T-ALLs.


Assuntos
Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Criança , Humanos , Camundongos , Animais , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Dasatinibe/farmacologia , Dasatinibe/uso terapêutico , Peixe-Zebra/metabolismo , Tirosina , Linhagem Celular Tumoral , Transdução de Sinais , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Receptores de Antígenos de Linfócitos T/uso terapêutico , Linfócitos T/metabolismo , Recidiva , Mamíferos/metabolismo
3.
Phytother Res ; 38(2): 797-838, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38083970

RESUMO

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.


Assuntos
Fármacos Antiobesidade , Obesidade , Humanos , Animais , Obesidade/tratamento farmacológico , Fármacos Antiobesidade/farmacologia , Fármacos Antiobesidade/uso terapêutico
4.
Chemistry ; 29(9): e202203238, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36376244

RESUMO

Three S-fused polycyclic aromatic hydrocarbons (PAHs) bearing cyclopenta[b]thiopyran moieties have been designed and successfully synthesized. With the conjugation extension, the absorption onset of the longest PAH reaches 1110 nm. All the three S-fused PAHs exhibit significant halochromic properties in both solution and solid states. Upon protonation, the proton is incorporated on the cyclopentadiene ring while the positive charge is localized on the thiopyrylium ring. Moreover, no significant difference can be found for the two shorter PAHs upon the protonation by different organic acids, such as trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TfOH), while the longest PAH can be only mono-protonated by TFA but di-protonated by stronger TfOH. Furthermore, after protonation, the non-emissive S-fused PAHs exhibit strong fluorescence and can be regenerated by simply neutralization with triethylamine. The enhanced emission of mono-protonated products stem from S2 →S0 transitions, which disobey the Kasha's rule.

5.
Diabetes Obes Metab ; 25(5): 1147-1161, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36655379

RESUMO

Dietary salt (NaCl) is essential to an organism's survival. However, today's diets are dominated by excessive salt intake, which significantly impacts individual and population health. High salt intake is closely linked to cardiovascular disease (CVD), especially hypertension, through a number of well-studied mechanisms. Emerging evidence indicates that salt overconsumption may also be associated with metabolic disorders. In this review, we first summarize recent updates on the mechanisms of salt-induced CVD, the effects of salt reduction and the use of salt substitution as a therapy. Next, we focus on how high salt intake can impact metabolism and energy balance, describing the mechanisms through which this occurs, including leptin resistance, the overproduction of fructose and ghrelin, insulin resistance and altered hormonal factors. A further influence on metabolism worth noting is the reported role of salt in inducing thermogenesis and increasing body temperature, leading to an increase in energy expenditure. While this result could be viewed as a positive metabolic effect because it promotes a negative energy balance to combat obesity, caution must be taken with this frame of thinking given the deleterious consequences of chronic high salt intake on cardiovascular health. Nevertheless, this review highlights the importance of salt as a noncaloric nutrient in regulating whole-body energy homeostasis. Through this review, we hope to provide a scientific framework for future studies to systematically address the metabolic impacts of dietary salt and salt replacement treatments. In addition, we hope to form a foundation for future clinical trials to explore how these salt-induced metabolic changes impact obesity development and progression, and to elucidate the regulatory mechanisms that drive these changes, with the aim of developing novel therapeutics for obesity and CVD.


Assuntos
Doenças Cardiovasculares , Humanos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Cloreto de Sódio na Dieta/efeitos adversos , Obesidade/metabolismo , Dieta , Metabolismo Energético
6.
BMC Infect Dis ; 23(1): 830, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012576

RESUMO

BACKGROUND: We investigated the associations between the different doses of tigecycline, its efficacy and safety, and the role of tigecycline therapeutic drug monitoring for patients in the intensive care unit. METHODS: This study was a single-center cohort including patients infected with multidrug-resistant Acinetobacter baumannii (MDR-AB) and multidrug-resistant Klebsiella pneumoniae (MDR-KP) causing pulmonary infections. The steady-state plasma concentration after tigecycline administration was determined by High-Performance Liquid Chromatography (HPLC) in patients admitted to the ICU between October 2020 and December 2021. Multivariate analyses of tigecycline's clinical efficacy and safety were performed to control confounding factors. RESULTS: For this study, we included 45 patients and 45 blood samples to determine steady-state trough concentrations of tigecycline. All patients were divided into the High Dose (HD) and Standard Dose (SD) groups. The median trough concentration of tigecycline was 0.56 µg/mL in the HD group, which was higher than in the SD group (0,21 µg/mL), p = 0.000. There was no significant difference between the two groups of patients in terms of bacterial eradication rate, mortality rate, and clinical efficacy. Multiple regression analysis showed that the ICU days were correlated with mortality OR 1.030(1.005-1.056), p = 0.017. APACHE II was significantly associated with clinical efficacy OR 0.870(0.755-1.002), p = 0.045. The level of fibrinogen decline in the HD group was significantly higher than in the SD group (-3.05 ± 1.67 vs -1.75 ± 1.90), p = 0.038. We identified that age and tigecycline treatment duration influenced fibrinogen decline. CONCLUSIONS: Tigecycline plasma concentrations are significantly increased when using a high dose. However, the plasma concentration of tigecycline is not correlated with clinical efficacy and adverse reactions. Fibrinogen decline appears to be related to the patient's age and days of tigecycline. Large sample data are still needed to confirm the clinical guidance significance of tigecycline TDM.


Assuntos
Acinetobacter baumannii , Pneumonia Bacteriana , Humanos , Tigeciclina/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Carbapenêmicos/uso terapêutico , Carbapenêmicos/farmacologia , Monitoramento de Medicamentos , Estudos Retrospectivos , Pneumonia Bacteriana/tratamento farmacológico , Resultado do Tratamento , Bactérias Gram-Negativas , Unidades de Terapia Intensiva , Fibrinogênio , Farmacorresistência Bacteriana Múltipla , Minociclina/uso terapêutico
7.
BMC Cardiovasc Disord ; 23(1): 239, 2023 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-37149580

RESUMO

BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) limits therapeutic revascularization. Neuropeptide Y (NPY), co-stored and co-released with the sympathetic nervous system, is involved in this process, but its exact role and underlying mechanisms remain to be fully understood. This study aimed to investigate the role of NPY in neointima formation after vascular injury. METHODS: Using the left carotid arteries of wild-type (WT, NPY-intact) and NPY-deficient (NPY-/-) mice, ferric chloride-mediated carotid artery injury induced neointima formation. Three weeks after injury, the left injured carotid artery and contralateral uninjured carotid artery were collected for histological analysis and immunohistochemical staining. RT-qPCR was used to detect the mRNA expression of several key inflammatory markers and cell adhesion molecules in vascular samples. Raw264.7 cells were treated with NPY, lipopolysaccharide (LPS), and lipopolysaccharide-free, respectively, and RT-qPCR was used to detect the expression of these inflammatory mediators. RESULTS: Compared with WT mice, NPY-/- mice had significantly reduced neointimal formation three weeks after injury. Mechanistically, immunohistochemical analysis showed there were fewer macrophages and more vascular smooth muscle cells in the neointima of NPY-/- mice. Moreover, the mRNA expression of key inflammatory markers such as interleukin-6 (IL-6), transforming growth factor-ß1 (TGF-ß1), and intercellular adhesion molecule-1 (ICAM-1) was significantly lower in the injured carotid arteries of NPY-/- mice, compared to that in the injured carotid arteries of WT mice. In RAW264.7 macrophages, NPY significantly promoted TGF-ß1 mRNA expression under unactivated but not LPS-stimulated condition. CONCLUSIONS: Deletion of NPY attenuated neointima formation after artery injury, at least partly, through reducing the local inflammatory response, suggesting that NPY pathway may provide new insights into the mechanism of restenosis.


Assuntos
Lesões das Artérias Carótidas , Neuropeptídeo Y , Intervenção Coronária Percutânea , Lesões do Sistema Vascular , Animais , Camundongos , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/metabolismo , Lesões das Artérias Carótidas/patologia , Proliferação de Células , Miócitos de Músculo Liso/metabolismo , Neointima/patologia , Neuropeptídeo Y/genética , RNA Mensageiro , Fator de Crescimento Transformador beta1/genética , Lesões do Sistema Vascular/genética , Lesões do Sistema Vascular/patologia
8.
J Comput Assist Tomogr ; 47(4): 539-547, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36877762

RESUMO

PURPOSE: This study aimed to explore the predictive performance of diffusion-weighted imaging with apparent diffusion coefficient map in predicting the proliferation rate of hepatocellular carcinoma and to develop a radiomics-based nomogram. METHODS: This was a single-center retrospective study. A total of 110 patients were enrolled. The sample included 38 patients with low Ki67 expression (Ki67 ≤10%) and 72 with high Ki67 expression (Ki67 >10%) as demonstrated by surgical pathology. Patients were randomly divided into either a training (n = 77) or validation (n = 33) cohort. Diffusion-weighted imaging with apparent diffusion coefficient maps was used to extract radiomic features and the signal intensity values of tumor (SI tumor ), normal liver (SI liver ), and background noise (SI background ) from all samples. Subsequently, the clinical model, radiomic model, and fusion model (with clinical data and radiomic signature) were developed and validated. RESULTS: The area under the curve (AUC) of the clinical model for predicting the Ki67 expression including serum α-fetoprotein level ( P = 0.010), age ( P = 0.015), and signal noise ratio ( P = 0.026) was 0.799 and 0.715 in training and validation cohorts, respectively. The AUC of the radiomic model constructed by 9 selected radiomic features was 0.833 and 0.772 in training and validation cohorts, respectively. The AUC of the fusion model containing serum α-fetoprotein level ( P = 0.011), age ( P = 0.019), and rad score ( P < 0.001) was 0.901 and 0.781 in training and validation cohorts, respectively. CONCLUSIONS: Diffusion-weighted imaging as a quantitative imaging biomarker can predict Ki67 expression level in hepatocellular carcinoma across various models.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Nomogramas , Estudos Retrospectivos , Antígeno Ki-67 , alfa-Fetoproteínas , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Proliferação de Células , Imageamento por Ressonância Magnética/métodos
9.
Acta Radiol ; 64(12): 2977-2986, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37753552

RESUMO

BACKGROUND: Hepatic lesions categorized as LR-3, LR-4, and LR-M are challenging to accurately assess and diagnose. PURPOSE: To combine potential clinical and/or magnetic resonance imaging (MRI) features for a more comprehensive hepatocellular carcinoma (HCC) versus non-HCC diagnosis for patients with LR-3, LR-4, and LR-M graded lesions. METHODS: Data were consecutively retrieved from 82 at-risk patients with LR-3 (n = 43), LR-4 (n = 20), and LR-M (n = 23) lesions. Significant findings for the differentiation of HCC and non-HCC, including MRI features and clinical factors, were identified with univariable and multivariable analyses. The variables for a prediction model were selected through stepwise use of Akaike's Information Criterion (AIC) to build multivariable logistic regression model. RESULTS: Serum alpha-fetoprotein (AFP) >16.2 ng/mL (odds ratio [OR] = 22.4; P = 0.006), septum (OR = 52.1; P = 0.011), and hepatobiliary phase (HBP) hypointensity (OR = 40.2; P = 0.001) were confirmed as independent predictors of HCC. When combining the three predictors and mild-moderate T2 hyperintensity, the model (AIC = 50.91) showed good accuracy with a C-index of 0.948. CONCLUSION: In at-risk patients with LR-3, LR-4, or LR-M lesions, integrating AFP, septum, HBP hypointensity, and mild-moderate T2 hyperintensity achieved high diagnostic performance for the diagnosis of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , alfa-Fetoproteínas , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
Angew Chem Int Ed Engl ; 62(9): e202216713, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36515468

RESUMO

Organic p-type cathode materials have recently attracted increasing attention due to their higher redox potentials and rate capabilities in comparison to n-type cathodes. However, most of the p-type cathodes based on one-electron redox still suffer from limited stability and low specific capacity (<150 mAh g-1 ). Herein, two polymers, conjugated poly(diethyldihydrophenazine vinylene) (CPP) and non-conjugated poly(diethyldihydrophenazine ethylidene) (NCPP) containing two-electron redox dihydrophenazine, have been developed as p-type cathode materials. It is experimentally and theoretically found that the conjugated linkage among the redox centers in polymer CPP is more favorable for the effective charge delocalization on the conjugated polymer backbone and the sufficient oxidation in the higher potential region (3.3-4.2 V vs. Li/Li+ ). Consequently, the CPP cathode displays a higher reversible specific capacity of 184 mAh g-1 with excellent cycling stability.

11.
Diabetologia ; 65(6): 984-996, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35316840

RESUMO

AIMS/HYPOTHESIS: Pancreatic beta cell dedifferentiation, transdifferentiation into other islet cells and apoptosis have been implicated in beta cell failure in type 2 diabetes, although the mechanisms are poorly defined. The endoplasmic reticulum stress response factor X-box binding protein 1 (XBP1) is a major regulator of the unfolded protein response. XBP1 expression is reduced in islets of people with type 2 diabetes, but its role in adult differentiated beta cells is unclear. Here, we assessed the effects of Xbp1 deletion in adult beta cells and tested whether XBP1-mediated unfolded protein response makes a necessary contribution to beta cell compensation in insulin resistance states. METHODS: Mice with inducible beta cell-specific Xbp1 deletion were studied under normal (chow diet) or metabolic stress (high-fat diet or obesity) conditions. Glucose tolerance, insulin secretion, islet gene expression, alpha cell mass, beta cell mass and apoptosis were assessed. Lineage tracing was used to determine beta cell fate. RESULTS: Deletion of Xbp1 in adult mouse beta cells led to beta cell dedifferentiation, beta-to-alpha cell transdifferentiation and increased alpha cell mass. Cell lineage-specific analyses revealed that Xbp1 deletion deactivated beta cell identity genes (insulin, Pdx1, Nkx6.1, Beta2, Foxo1) and derepressed beta cell dedifferentiation (Aldh1a3) and alpha cell (glucagon, Arx, Irx2) genes. Xbp1 deletion in beta cells of obese ob/ob or high-fat diet-fed mice triggered diabetes and worsened glucose intolerance by disrupting insulin secretory capacity. Furthermore, Xbp1 deletion increased beta cell apoptosis under metabolic stress conditions by attenuating the antioxidant response. CONCLUSIONS/INTERPRETATION: These findings indicate that XBP1 maintains beta cell identity, represses beta-to-alpha cell transdifferentiation and is required for beta cell compensation and prevention of diabetes in insulin resistance states.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Células Secretoras de Insulina , Proteína 1 de Ligação a X-Box/metabolismo , Animais , Transdiferenciação Celular/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Células Secretoras de Insulina/metabolismo , Camundongos , Estresse Fisiológico , Proteína 1 de Ligação a X-Box/genética
12.
J Cell Physiol ; 237(5): 2574-2588, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35312067

RESUMO

Chronic high salt intake is one of the leading causes of hypertension. Salt activates the release of the key neurotransmitters in the hypothalamus such as vasopressin to increase blood pressure, and neuropepetide Y (NPY) has been implicated in the modulation of vasopressin levels. NPY in the hypothalamic arcuate nucleus (Arc) is best known for its control in appetite and energy homeostasis, but it is unclear whether it is also involved in the development of salt-induced hypertension. Here, we demonstrate that wild-type mice given 2% NaCl salt water for 8 weeks developed hypertension which was associated with marked downregulation of NPY expression in the hypothalamic Arc as demonstrated in NPY-GFP reporter mice as well as by in situ hybridization analysis. Furthermore, salt intake activates neurons in the hypothalamic paraventricular nucleus (PVN) where mRNA expression of brain-derived neurotrophic factor (BDNF) and vasopressin was found to be upregulated, leading to elevated serum vasopressin levels. This finding suggests an inverse correlation between the Arc NPY level and expression of vasopressin and BDNF in the PVN. Specific restoration of NPY by injecting AAV-Cre recombinase into the Arc only of the NPY-targeted mutant mice carrying a loxP-flanked STOP cassette reversed effects of salt intake on vasopressin and BDNF expression, leading to a normalization of salt-dependent blood pressure. In summary, our study uncovers an important Arc NPY-originated neuronal circuitry that could sense and respond to peripheral electrolyte signals and thereby regulate hypertension via vasopressin and BDNF in the PVN.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Hipertensão , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Hipertensão/induzido quimicamente , Camundongos , Neuropeptídeo Y/metabolismo , Cloreto de Sódio , Cloreto de Sódio na Dieta , Vasopressinas
13.
Ecol Lett ; 25(5): 1202-1214, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35230727

RESUMO

Scatter- and larder hoarding are the primary strategies of food-hoarding animals and have important implications for plant-animal interactions and plant recruitment. However, their origins and influencing factors have not been fully investigated across a wide range of taxa. Our systematic literature search amassed data for 183 seed-hoarding rodent species worldwide and tested relationships of seed-hoarding behaviours with phylogenetic signal, functional traits and environmental factors. We found that the evolution of hoarding strategies was not random in phylogeny, and scatter hoarding originated independently multiple times from larder hoarding. Rodents with higher encephalisation quotient (relative brain size), omnivorous diet (related to dependence on seeds) and inhabiting lower latitudes were disproportionately likely to scatter hoard. Despite body mass's potential relationship with competition through food defence, it was associated with food-hoarding strategy only in a few families. Our results show the need to study the community and ecological context of food-hoarding behaviours.


Assuntos
Colecionismo , Roedores , Animais , Comportamento Alimentar , Humanos , Filogenia , Sementes
14.
J Anim Ecol ; 91(4): 738-751, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35061910

RESUMO

Ecological networks describe ecological interactions among species in ecosystems. In natural ecosystems, plant-mutualist (PM) and plant-herbivore (PH) networks are two of the most documented bipartite ecological networks, which are often interconnected through shared plants to form multilayer networks (here referred to as ecological networks with multiple interaction types). Recent developments in multilayer networks have challenged the effects of topological properties on biodiversity and stability once found in ecological networks with a single interaction type. In this study, my goal was to theoretically test the effects of the nested topology of subnetworks (i.e. plant-mutualist and plant-herbivore networks) on the local stability and persistence of the entire community and determine how their effect sizes were dependent on subnetwork structures and interconnection patterns. I used a simple algorithm to construct plant-mutualist or plant-herbivore networks with different levels of nestedness while fixing connectance and network size. By artificially interconnecting plant-mutualist and plant-herbivore networks through shared plants, I also manipulated the inter-subnetwork connection patterns as positive, negative and no correlations between the number of interacting partners of shared plants of two subnetworks. Community dynamics were simulated to show how subnetwork nestedness interacted with other network properties to affect local stability and persistence of multilayer networks. I found that low nestedness of both plant-mutualist and plant-herbivore subnetworks promoted stability and persistence. Effect sizes of the focal PM- or PH-subnetwork nestedness were positively associated with the nestedness levels of the interconnected subnetworks. A positive correlation between the mutualistic and herbivory generalism of plants also led to higher (signed) effect sizes of subnetwork nestedness. Further analyses showed that the effect sizes of the subnetwork nestedness also depended on subnetwork complexity and intraguild competition intensity. Finally, the modularity of interconnected subnetworks had little association with the effect sizes of subnetwork nestedness irrespective of interconnection patterns. The results demonstrate that the effects of topological structures (such as nestedness) on community dynamics in single-interaction networks may be altered by the architectures of multilayer networks, which highlights the need to study the interactions between the architectures of within- and inter-subnetworks in affecting ecosystem stability and biodiversity.


Assuntos
Ecossistema , Plantas , Animais , Biodiversidade , Herbivoria , Simbiose
15.
Cell Mol Biol Lett ; 27(1): 72, 2022 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-36058940

RESUMO

Osteoporotic fractures lead to increased disability and mortality in the elderly population. With the rapid increase in the aging population around the globe, more effective treatments for osteoporosis and osteoporotic fractures are urgently required. The underlying molecular mechanisms of osteoporosis are believed to be due to the increased activity of osteoclasts, decreased activity of osteoblasts, or both, which leads to an imbalance in the bone remodeling process with accelerated bone resorption and attenuated bone formation. Currently, the available clinical treatments for osteoporosis have mostly focused on factors influencing bone remodeling; however, they have their own limitations and side effects. Recently, cytokine immunotherapy, gene therapy, and stem cell therapy have become new approaches for the treatment of various diseases. This article reviews the latest research on bone remodeling mechanisms, as well as how this underpins current and potential novel treatments for osteoporosis.


Assuntos
Reabsorção Óssea , Osteoporose , Fraturas por Osteoporose , Idoso , Remodelação Óssea , Reabsorção Óssea/complicações , Reabsorção Óssea/terapia , Humanos , Osteoclastos , Osteoporose/tratamento farmacológico , Fraturas por Osteoporose/complicações
16.
Neurol Sci ; 43(7): 4483-4491, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35138478

RESUMO

BACKGROUND: GNE myopathy is the most common distal myopathy in China. We summarized the clinical, genetic, and pathological characteristics of 125 Chinese patients with GNE myopathy. METHODS: We collected clinical data of 21 patients diagnosed at our hospital and 104 patients from previous reports. Clinical, genetic, and pathological characteristics were summarized. According to the location of mutations, patients were classified into groups to analyze genotype-phenotype correlation. We reviewed the pathological features and studied the expressions of neural cell adhesion molecule. RESULTS: The severity of involvement of lower limb muscles was in the following order: tibialis anterior > biceps femoris > gastrocnemius > iliopsoas > quadriceps femoris. Mutation p.D207V was the most common variant in China. Patients carrying p.D207V tended to show later disease onset. In the epimerase/epimerase group, men had earlier disease onset than women (p < 0.05). In other groups, age at disease onset in females was earlier than that in males. Protein analysis showed decreased sialylation of NCAM and upregulation of LC3 in patients with different mutations. CONCLUSIONS: Mutation p.D207V is the most common GNE variant in China. Involvement of flexor muscles in lower limbs was more obvious than extensor muscles. NCAM expression in patients with various mutations may be a useful diagnostic biomarker in GNE myopathy.


Assuntos
Miopatias Distais , Moléculas de Adesão de Célula Nervosa , Antígeno CD56 , Miopatias Distais/diagnóstico , Miopatias Distais/genética , Miopatias Distais/patologia , Feminino , Humanos , Masculino , Complexos Multienzimáticos/genética , Músculo Esquelético/patologia , Mutação , Moléculas de Adesão de Célula Nervosa/genética , Racemases e Epimerases/genética
17.
Proc Natl Acad Sci U S A ; 116(38): 19001-19008, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31481618

RESUMO

Accelerated anthropogenic impacts and climatic changes are widely considered to be responsible for unprecedented species extinction. However, determining their effects on extinction is challenging owing to the lack of long-term data with high spatial and temporal resolution. In this study, using historical occurrence records of 11 medium- to large-sized mammal species or groups of species in China from 905 BC to AD 2006, we quantified the distinctive associations of anthropogenic stressors (represented by cropland coverage and human population density) and climatic stressors (represented by air temperature) with the local extinction of these mammals. We found that both intensified human disturbances and extreme climate change were associated with the increased local extinction of the study mammals. In the cold phase (the premodern period of China), climate cooling was positively associated with increased local extinction, while in the warm phase (the modern period) global warming was associated with increased local extinction. Interactive effects between human disturbance and temperature change with the local extinction of elephants, rhinos, pandas, and water deer were found. Large-sized mammals, such as elephants, rhinos, and pandas, showed earlier and larger population declines than small-sized ones. The local extinction sensitivities of these mammals to the human population density and standardized temperature were estimated during 1700 to 2000. The quantitative evidence for anthropogenic and climatic associations with mammalian extinction provided insights into the driving processes of species extinction, which has important implications for biodiversity conservation under accelerating global changes.


Assuntos
Mudança Climática , Extinção Biológica , Aquecimento Global/história , Atividades Humanas/estatística & dados numéricos , Mamíferos/classificação , Mamíferos/crescimento & desenvolvimento , Densidade Demográfica , Animais , Biodiversidade , Ecossistema , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos
18.
J Am Chem Soc ; 143(29): 11088-11101, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34270228

RESUMO

Cyclopenta[b]thiopyran, isomeric to benzo[b]thiophene while isoelectronic to azulene, is involved as a building block to construct soluble organic semiconductors for field-effect transistors. Two series of angular-shaped heteroarenes based on cyclopenta[b]thiopyran, that is, Cn-SS (n = 4, 6, 8, 10) with different linear alkyl groups and C8-SS-Clm (m = 2, 3, 4) with chlorides substituted at different positions, have been straightforward synthesized. The obtained seven S-heteroarenes exhibit intriguing and similar photophysical and electrochemical properties, such as near-infrared absorption and high-energy levels of the highest occupied molecular orbitals. Nevertheless, the S-heteroarenes with identical π-conjugated skeletons demonstrate completely different molecular packing structures, which is proofed to be the key determinate factor for the charge carrier mobilities. Upon the engineering of the pendant alkyl lengths, the highest hole mobility in the Cn-SS series is achieved for C8-SS (1.1 cm2 V-1 s-1) with moderate alkyl length. The further incorporation of chlorides on C8-SS results in the shortened intermolecular H···S contacts and the interplane distances. Most interestingly, when chlorine-containing chloroform and chlorobenzene are used as crystallization solvents, single crystals of C8-SS-Clm with different packing structures are produced owing to the intermolecular interactions among the solute and solvent molecules. Upon further engineering of the chlorination position and the crystallization solvent, the maximum hole mobility in the ambient air improves to 2.7 cm2 V-1 s-1 for C8-SS-Cl2 crystallized from chlorobenzene, suggesting that the introduction of the accessible chlorides is a feasible pathway to engineering the crystal structures and controlling the charge transport characteristics.

19.
J Neuroinflammation ; 18(1): 145, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183017

RESUMO

BACKGROUND: Experimental autoimmune encephalomyelitis (EAE) is an animal disease model of multiple sclerosis (MS) that involves the immune system and central nervous system (CNS). However, it is unclear how genetic predispositions promote neuroinflammation in MS and EAE. Here, we investigated how partial loss-of-function of suppressor of MEK1 (SMEK1), a regulatory subunit of protein phosphatase 4, facilitates the onset of MS and EAE. METHODS: C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55) to establish the EAE model. Clinical signs were recorded and pathogenesis was investigated after immunization. CNS tissues were analyzed by immunostaining, quantitative polymerase chain reaction (qPCR), western blot analysis, and enzyme-linked immunosorbent assay (ELISA). Single-cell analysis was carried out in the cortices and hippocampus. Splenic and lymph node cells were evaluated with flow cytometry, qPCR, and western blot analysis. RESULTS: Here, we showed that partial Smek1 deficiency caused more severe symptoms in the EAE model than in controls by activating myeloid cells and that Smek1 was required for maintaining immunosuppressive function by modulating the indoleamine 2,3-dioxygenase (IDO1)-aryl hydrocarbon receptor (AhR) pathway. Single-cell sequencing and an in vitro study showed that Smek1-deficient microglia and macrophages were preactivated at steady state. After MOG35-55 immunization, microglia and macrophages underwent hyperactivation and produced increased IL-1ß in Smek1-/+ mice at the peak stage. Moreover, dysfunction of the IDO1-AhR pathway resulted from the reduction of interferon γ (IFN-γ), enhanced antigen presentation ability, and inhibition of anti-inflammatory processes in Smek1-/+ EAE mice. CONCLUSIONS: The present study suggests a protective role of Smek1 in autoimmune demyelination pathogenesis via immune suppression and inflammation regulation in both the immune system and the central nervous system. Our findings provide an instructive basis for the roles of Smek1 in EAE and broaden the understanding of the genetic factors involved in the pathogenesis of autoimmune demyelination.


Assuntos
Sistema Nervoso Central/patologia , Encefalomielite Autoimune Experimental , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interferon gama/metabolismo , Microglia/imunologia , Fosfoproteínas Fosfatases/imunologia , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/fisiopatologia , Citocinas , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Técnicas de Inativação de Genes , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Esclerose Múltipla/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Células Mieloides/imunologia , Células Mieloides/metabolismo , Fragmentos de Peptídeos/imunologia , Fosfoproteínas Fosfatases/metabolismo , Transdução de Sinais , Baço/patologia
20.
Environ Sci Technol ; 55(9): 6140-6149, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33797225

RESUMO

Organochlorine pesticides (OCPs) have been used worldwide on an enormous scale over the last century but are banned globally due to environmental persistence and ecotoxicity in recent decades. The long-term effects of OCP ban for agricultural use in China since 1983 on the reproductive health of small terrestrial mammals have never been evaluated in the field. We examined the residue dynamics of OCPs and the reproductive performance of Chinese striped hamsters (Cricetulus barabensis) in North China Plain during 1983-2010 and concluded that the exposure levels of OCPs in hamsters drastically decreased from 2900 ± 740 to 25.2 ± 6.88 ng/g with an average half-life of 5.08 yrs, coinciding with the observed reproductive recovery of hamsters. The population-based reproductive performance of hamsters was significantly and negatively associated with OCP exposure levels after adjusting the contributions from climate and population density factors, indicating that the ban of OCPs has facilitated the reproductive recovery of hamsters by up to 81% contribution. Our findings suggest that the OCP ban is effective to restore reproduction of small terrestrial mammals. Integration of population biology and environmental science is essential to assess the impacts of persistent organic pollutants on ecological safety and biodiversity loss under accelerated global change.


Assuntos
Hidrocarbonetos Clorados , Praguicidas , Animais , China , Cricetinae , Cricetulus , Monitoramento Ambiental , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Reprodução
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