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1.
Exp Eye Res ; 246: 110021, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39117136

RESUMO

Retinal injury may be exacerbated by iron overload. Astragaloside IV (AS-IV) has potential applications in the food and healthcare industry to promote eye health. We sought to determine the mechanisms responsible for the protective effects of AS-IV on photoreceptor and retinal pigment epithelium cell death induced by iron overload. We conducted in vitro and in vivo experiments involving AS-IV pretreatment. We tested AS-IV for its ability to protect iron-overload mice from retinal injury. In particular, we analyzed the effects of AS-IV on iron overload-induced ferroptosis in 661W and ARPE-19 cells. AS-IV not only attenuated iron deposition and retinal injury in iron-overload mice but also effectively reduced iron overload-induced ferroptotic cell death in 661W and ARPE-19 cells. AS-IV effectively prevented ferroptosis by inhibiting iron accumulation and lipid peroxidation. In addition, inhibiting nuclear factor erythroid 2-related factor 2 (Nrf2) eliminated the protective effect of AS-IV against ferroptosis. The results suggest that ferroptosis might be a significant cause of retinal cell death associated with iron overload. AS-IV provides protection from iron overload-induced ferroptosis, partly by activating the Nrf2 signaling pathway.


Assuntos
Ferroptose , Sobrecarga de Ferro , Camundongos Endogâmicos C57BL , Epitélio Pigmentado da Retina , Saponinas , Triterpenos , Ferroptose/efeitos dos fármacos , Animais , Triterpenos/farmacologia , Triterpenos/uso terapêutico , Saponinas/farmacologia , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/tratamento farmacológico , Camundongos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Modelos Animais de Doenças , Peroxidação de Lipídeos/efeitos dos fármacos , Humanos , Doenças Retinianas/prevenção & controle , Doenças Retinianas/metabolismo , Doenças Retinianas/patologia , Doenças Retinianas/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Western Blotting , Masculino , Ferro/metabolismo
2.
J Biol Chem ; 297(3): 101022, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34332978

RESUMO

Transient receptor potential vanilloid 1 (TRPV1) ion channel serves as the detector for noxious temperature above 42 °C, pungent chemicals like capsaicin, and acidic extracellular pH. This channel has also been shown to function as an ionotropic cannabinoid receptor. Despite the solving of high-resolution three-dimensional structures of TRPV1, how endocannabinoids such as anandamide and N-arachidonoyl dopamine bind to and activate this channel remains largely unknown. Here we employed a combination of patch-clamp recording, site-directed mutagenesis, and molecular docking techniques to investigate how the endocannabinoids structurally bind to and open the TRPV1 ion channel. We found that these endocannabinoid ligands bind to the vanilloid-binding pocket of TRPV1 in the "tail-up, head-down" configuration, similar to capsaicin; however, there is a unique interaction with TRPV1 Y512 residue critical for endocannabinoid activation of TRPV1 channels. These data suggest that a differential structural mechanism is involved in TRPV1 activation by endocannabinoids compared with the classic agonist capsaicin.


Assuntos
Capsaicina/farmacologia , Endocanabinoides/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Células HEK293 , Humanos , Ligantes , Camundongos , Simulação de Acoplamento Molecular , Técnicas de Patch-Clamp , Ligação Proteica , Canais de Cátion TRPV/agonistas
3.
J Biol Chem ; 297(1): 100806, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34022223

RESUMO

Sensing noxiously high temperatures is crucial for living organisms to avoid heat-induced injury. The TRPV1 channel has long been known as a sensor for noxious heat. However, the mechanism of how this channel is activated by heat remains elusive. Here we found that a series of polyols including sucrose, sorbitol, and hyaluronan significantly elevate the heat activation threshold temperature of TRPV1. The modulatory effects of these polyols were only observed when they were perfused extracellularly. Interestingly, mutation of residues E601 and E649 in the outer pore region of TRPV1 largely abolished the effects of these polyols. We further observed that intraplantar injection of polyols into the hind paws of rats reduced their heat-induced pain response. Our observations not only suggest that the extracellular regions of TRPV1 are critical for the modulation of heat activation by polyols, but also indicate a potential role of polyols in reducing heat-induced pain sensation.


Assuntos
Temperatura Alta , Polímeros/farmacologia , Canais de Cátion TRPV/metabolismo , Sequência de Aminoácidos , Animais , Capsaicina/farmacologia , Espaço Extracelular/química , Feminino , Células HEK293 , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Polímeros/química , Prótons , Ratos Wistar , Canais de Cátion TRPV/química
4.
J Neuroinflammation ; 19(1): 39, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35130930

RESUMO

BACKGROUND: Mounting evidences indicate that oxidative stress, neuroinflammation, and dysregulation of gut microbiota are related to neurodegenerative disorders (NDs). Butyrolactone I (BTL-I), a marine fungal metabolite, was previously reported as an in vitro neuroprotectant and inflammation inhibitor. However, little is known regarding its in vivo effects, whereas zebrafish (Danio rerio) could be used as a convenient in vivo model of toxicology and central nervous system (CNS) diseases. METHODS: Here, we employed in vivo and in silico methods to investigate the anti-NDs potential of BTL-I. Specifically, we established a cognitive deficit model in zebrafish by intraperitoneal (i.p.) injection of aluminum trichloride (AlCl3) (21 µg) and assessed their behaviors in the T-maze test. The proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) as well as acetylcholinesterase (AChE) activity or glutathione (GSH) levels were assayed 24 h after AlCl3 injection. The intestinal flora variation of the zebrafish was investigated by 16S rDNA high-throughput analysis. The marine fungal metabolite, butyrolactone I (BTL-I), was used to modulate zebrafish cognitive deficits evoked by AlCl3 and evaluated about its effects on the above inflammatory, cholinergic, oxidative stress, and gut floral indicators. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) and drug-likeness properties of BTL-I were studied by the in silico tool ADMETlab. RESULTS: BTL-I dose-dependently ameliorated AlCl3-induced cognitive deficits in zebrafish. While AlCl3 treatment elevated the levels of central and peripheral proinflammatory cytokines, increased AChE activity, and lowered GSH in the brains of zebrafish, these effects, except GSH reduction, were reversed by 25-100 mg/kg BTL-I administration. Besides, 16S rDNA high-throughput sequencing of the intestinal flora of zebrafish showed that AlCl3 decreased Gram-positive bacteria and increased proinflammatory Gram-negative bacteria, while BTL-I contributed to maintaining the predominance of beneficial Gram-positive bacteria. Moreover, the in silico analysis indicated that BTL-I exhibits acceptable drug-likeness and ADMET profiles. CONCLUSIONS: The present findings suggest that BTL-I is a potential therapeutic agent for preventing CNS deficits caused by inflammation, neurotoxicity, and gut flora imbalance.


Assuntos
Microbioma Gastrointestinal , Peixe-Zebra , 4-Butirolactona/análogos & derivados , Acetilcolinesterase/metabolismo , Acetilcolinesterase/farmacologia , Cloreto de Alumínio/toxicidade , Animais , Cognição , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Estresse Oxidativo , Peixe-Zebra/metabolismo
5.
BMC Cancer ; 22(1): 265, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35287604

RESUMO

BACKGROUND: Reportedly, circular RNA (circRNA) is a key modulator in the development of human malignancies. This work is aimed to probe the expression pattern, biological effects and mechanism of circ_0064288 on hepatocellular carcinoma (HCC) progression. METHODS: The differentially expressed circRNA was screened by analyzing the expression profiles of circRNAs in HCC tissues and normal tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine the expression of circ_0064288, miR-335-5p and Rho associated coiled-coil containing protein kinase 1 (ROCK1) mRNA in HCC specimens. After circ_0064288 was overexpressed or knocked down in HCC cells, cell growth was detected by the CCK-8 experiment, and cell migration was evaluated using Transwell experiment and scratch healing experiment. The targeting relationship between miR-335-5p and circ_0064288 and ROCK1 mRNA was predicted and verified using bioinformatic analysis and dual-luciferase reporter gene experiments, respectively. Western blot was executed to examine ROCK1 protein expression in HCC cells. RESULTS: Circ_0064288 and ROCK1 expression was up-modulated in HCC, while miR-335-5p was down-modulated. High circ_0064288 expression was associated with shorter survival time of HCC patients. It was also revealed that circ_0064288 overexpression remarkably enhanced HCC cell growth and migration, while knockdown of circ_0064288 induced opposite effects. Additionally, circ_0064288 could competitively bind with miR-335-5p thereby up-modulate ROCK1 expression. MiR-335-5p overexpression partly counteracted the effect of circ_0064288 overexpression on HCC cells. CONCLUSION: Circ_0064288 facilitates HCC cell growth and migration by modulating the miR-335-5p/ROCK1 axis.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , MicroRNAs/metabolismo , RNA Circular/metabolismo , Quinases Associadas a rho/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Oncogenes/genética , Reação em Cadeia da Polimerase em Tempo Real
6.
Biosci Biotechnol Biochem ; 84(8): 1546-1553, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32434451

RESUMO

A new isoflavone derivative compound 1 (psoralenone) was isolated from soybean inoculated with a marine fungus Aspergillus terreus C23-3, together with seven known compounds including isoflavones 2-6, butyrolactone I (7) and blumenol A (8). Their structures were elucidated by MS, NMR, and ECD. Psoralenone displayed moderate in vitro anti-inflammatory activity in the LPS-induced RAW264.7 cell model. Compound 2 (genistein) showed moderate acetylcholinesterase (AChE) inhibitory activity whereas compounds 2, 5 (biochanin A), 6 (psoralenol), and 7 exhibited potent larvicidal activity against brine shrimp. Compounds 3 (daidzein), 4 (4'-hydroxy-6,7-dimethoxyisoflavone), and 5-7 showed broad-spectrum anti-microbial activity, and compound 7 also showed moderate 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity.


Assuntos
Anti-Inflamatórios/isolamento & purificação , Aspergillus/química , Glycine max/química , Isoflavonas/isolamento & purificação , Lipopolissacarídeos/antagonistas & inibidores , 4-Butirolactona/análogos & derivados , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/farmacologia , Acetilcolinesterase , Animais , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Aspergillus/fisiologia , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/farmacologia , Cicloexanonas/isolamento & purificação , Cicloexanonas/farmacologia , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Furocumarinas/isolamento & purificação , Furocumarinas/farmacologia , Genisteína/isolamento & purificação , Genisteína/farmacologia , Inflamação , Isoflavonas/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Células RAW 264.7 , Glycine max/microbiologia
7.
Chem Biodivers ; 17(8): e2000055, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32419273

RESUMO

Cholinergic disorder, oxidative stress, and neuroinflammation play important roles in the pathology of Alzheimer's disease. To explore the healthy potential of the edible seaweed Hizikia fusiforme on this aspect, a functional oil (HFFO) was extracted from this alga and investigated on its constituents by gas chromatography-mass spectrometry (GC/MS) in this study. Its anti-Alzheimer's related bioactivities including acetylcholinesterase (AChE) inhibition, antioxidation, and anti-neuroinflammation were evaluated, traced, and simulated by in vitro and in silico methods. GC/MS analysis indicated that HFFO mainly contained arachidonic acid (ARA), 11,14,17-eicosatrienoic acid (ETrA), palmitic acid, phytol, etc. HFFO showed moderate AChE inhibition and antioxidant activity. Bioactivity tracing using commercial standards verified that AChE inhibition of HFFO mainly originated from ARA and ETrA, whereas antioxidant activity mainly from ARA. Lineweaver-Burk plots showed that both ARA and ETrA are noncompetitive AChE inhibitors. A molecular docking study demonstrated low CDOCKER interaction energy of -26.33 kcal/mol for ARA and -43.70 kcal/mol for ETrA when interacting with AChE and multiple interactions in the ARA (or ETrA)-AChE complex. In the anti-neuroinflammatory evaluation, HFFO showed no toxicity toward BV-2 cells at 20 µg/mL and effectively inhibited the production of nitroxide and reduced the level of reactive oxygen species in lipopolysaccharide-induced BV-2 cells. The results indicated that HFFO could be used in functional foods for its anti-Alzheimer's disease-related activities.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Óleos de Plantas/farmacologia , Alga Marinha/química , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Cinética , Simulação de Acoplamento Molecular , Espécies Reativas de Oxigênio/metabolismo
8.
Molecules ; 23(9)2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-30177651

RESUMO

A new depsidone derivative (1), aspergillusidone G, was isolated from a marine fungus Aspergillus unguis, together with eight known depsidones (2‒9) and a cyclic peptide (10): agonodepside A (2), nornidulin (3), nidulin (4), aspergillusidone F (5), unguinol (6), aspergillusidone C (7), 2-chlorounguinol (8), aspergillusidone A (9), and unguisin A (10). Compounds 1‒4 and 7‒9 were obtained from the plasma induced mutant of this fungus, while 5, 6, and 10 were isolated from the original strain under chemical induction. Their structures were identified using spectroscopic analysis, as well as by comparison with literature data. The HPLC fingerprint analysis indicates that chemical induction and plasma mutagenesis effectively influenced the secondary metabolism, which may be due to their regulation in the key steps in depsidone biosynthesis. In bioassays, compound 9 inhibited acetylcholinesterase (AChE) with IC50 in 56.75 µM. Compounds 1, 5, 7, 8, and 9 showed moderate to strong activity towards different microbes. Compounds 3, 4, and 5 exhibited potent larvicidality against brine shrimp. In docking studies, higher negative CDOCKER interaction energy and richer strong interactions between AChE and 9 explained the greater activity of 9 compared to 1. Chemical induction and plasma mutagenesis can be used as tools to expand the chemodiversity of fungi and obtain useful natural products.


Assuntos
Anti-Infecciosos/isolamento & purificação , Aspergillus/genética , Inibidores da Colinesterase/isolamento & purificação , Depsídeos/isolamento & purificação , Peptídeos Cíclicos/isolamento & purificação , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Aspergillus/metabolismo , Candida albicans/efeitos dos fármacos , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Depsídeos/química , Depsídeos/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular , Mutação , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Gases em Plasma/farmacologia , Metabolismo Secundário , Staphylococcus aureus/efeitos dos fármacos , Vibrio parahaemolyticus/efeitos dos fármacos
9.
Sci Total Environ ; 949: 175084, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39074747

RESUMO

Grasslands are the most extensively distributed terrestrial ecosystems on Earth, providing a range of ecosystem services that are vital for sustaining human life and critical for sustainable development at the global scale. However, the relationship between the two most important attributes of grassland, plant diversity, and productivity, remains controversial even after many years of research. Here, we develop an analysis of covariance (ANCOVA) model based on decadal-scale experimental data from a degraded meadow steppe in northeastern Inner Mongolia, China to quantify the response of aboveground biomass (AGB) to plant species diversity under varying management regimes. We report that AGB responds negatively to the plant diversity in fallow grasslands and positively in grazing grasslands, transiting from negative to positive in mowing grasslands as mowing became more frequent. We show that the changing diversity-productivity relationships are driven by changes in species composition of the plant community, given the significant productivity gap between rare and non-rare species. This highlights the role of management in regulating the diversity-productivity relationships in grasslands. These results not only provide provocative insights into the relationships between plant diversity and productivity but also support more sustainable use and management of grassland resources.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Pradaria , China , Conservação dos Recursos Naturais/métodos , Biomassa , Monitoramento Ambiental
10.
Eur J Phys Rehabil Med ; 60(3): 391-399, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38577727

RESUMO

BACKGROUND: The cerebellum is a key structure involved in balance and motor control, and has become a new stimulation target in brain regulation technology. Interference theta-burst simulation (iTBS) is a novel simulation mode of repetitive transcranial magnetic simulation. However, the impact of cerebellar iTBS on balance function and gait in stroke patients is still unknown. AIM: The aim of this study was to determine whether cerebellar iTBS can improve function, particularly balance and gait, in patients with post-stroke hemiplegia. DESIGN: This study is a randomized, double-blind, sham controlled clinical trial. SETTING: The study was carried out at the Department of Rehabilitation Medicine in a general hospital. POPULATION: Patients with stroke with first unilateral lesions were enrolled in the study. METHODS: Thirty-six patients were randomly assigned to the cerebellar iTBS group or sham stimulation group. The cerebellar iTBS or pseudo stimulation site is the ipsilateral cerebellum on the paralyzed side, which is completed just before daily physical therapy. The study was conducted five times a week for two consecutive weeks. All patients were assessed before the intervention (T0) and at the end of 2 weeks of treatment (T1), respectively. The primary outcome was the Berg Balance Scale (BBS), while secondary outcome measures included the Fugl Meyer Lower Limb Assessment Scale (FMA-LE), timed up and go (TUG), Barthel Index (BI), and gait analysis. RESULTS: After 2 weeks of intervention, the BBS, FMA-LE, TUG, and BI score in both the iTBS group and the sham group were significantly improved compared to the baseline (all P<0.05). Also, there was a significant gait parameter improvement including the cadence, stride length, velocity, step length compared to the baseline (P<0.05) in the iTBS group, but only significant improvement in cadence was identified in the sham group (P<0.05). Intergroup comparison showed that the BBS (P<0.001), FMA-LE (P<0.001), and BI (P=0.002) in the iTBS group were significantly higher than those in the sham group, and the TUG in the iTBS was significantly lower than that in the sham group (P=0.002). In addition, there were significant differences in cadence (P=0.029), strip length (P=0.046), gain velocity (P=0.002), and step length of affected lower limb (P=0.024) between the iTBS group and the sham iTBS group. CONCLUSIONS: Physical therapy is able to improve the functional recovery in hemiplegic patients after stroke, but the cerebellar iTBS can facilitate and accelerate the recovery, particularly the balance function and gait. Cerebellar iTBS could be an efficient and facilitative treatment for patients with stroke. CLINICAL REHABILITATION IMPACT: Cerebellar iTBS provides a convenient and efficient treatment modality for functional recovery of patients with stroke, especially balance function and gait.


Assuntos
Cerebelo , Equilíbrio Postural , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estimulação Magnética Transcraniana , Humanos , Masculino , Equilíbrio Postural/fisiologia , Feminino , Pessoa de Meia-Idade , Método Duplo-Cego , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Magnética Transcraniana/métodos , Idoso , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Cerebelo/fisiopatologia , Transtornos Neurológicos da Marcha/reabilitação , Transtornos Neurológicos da Marcha/fisiopatologia , Transtornos Neurológicos da Marcha/etiologia , Hemiplegia/reabilitação , Hemiplegia/fisiopatologia , Hemiplegia/etiologia , Resultado do Tratamento , Marcha/fisiologia , Recuperação de Função Fisiológica
11.
Front Plant Sci ; 14: 1296544, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38235199

RESUMO

Introduction: The diversity-productivity relationship is a central issue in maintaining the grassland ecosystem's multifunctionality and supporting its sustainable management. Currently, the mainstream opinion on the diversity-productivity relationship recognizes that increases in species diversity promote ecosystem productivity. Methods: Here, we challenge this opinion by developing a generalized additive model-based framework to quantify the response rate of grassland productivity to plant species diversity using vegetation survey data we collected along a land-use intensity gradient in northern China. Results: Our results show that the grassland aboveground biomass responds significantly positively to the Shannon-Wiener diversity index at a rate of 46.8 g m-2 per unit increase of the Shannon-Wiener index in enclosure-managed grasslands, under the co-influence of climate and landscape factors. The aboveground biomass response rate stays positive at a magnitude of 47.1 g m-2 in forest understory grassland and 39.7 g m-2 in wetland grassland. Conversely, the response rate turns negative in heavily grazed grasslands at -55.8 g m-2, transiting via near-neutral rates of -7.0 and -7.3 g m-2 in mowing grassland and moderately grazed grassland, respectively. Discussion: These results suggest that the diversity-productivity relationship in temperate grasslands not only varies by magnitude but also switches directions under varying levels of land use intensity. This highlights the need to consider land use intensity as a more important ecological integrity indicator for future ecological conservation programs in temperate grasslands.

12.
Int J Biol Macromol ; 236: 123942, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36889620

RESUMO

Systemic chemotherapy after surgery is necessary to control tumor recurrence, but the severe side effects caused by chemotherapeutic drugs pose a great threat to patients' health. In this study, we originally develop a porous scaffold used for chemotherapy drug capture by using 3D printing technology. The scaffold is mainly composed of poly (ε-caprolactone) (PCL) and polyetherimide (PEI) with a mass ratio of 5/1. Subsequently, the printed scaffold is modified with DNA through the strong electrostatic integration between DNA and PEI to endow the scaffold with the specific absorption to doxorubicin (DOX, a widely used chemotherapy drug). The results show that pore diameter has an important influence on DOX adsorption, and smaller pores will ensure a higher DOX absorption. In vitro, the printed scaffold can absorb about 45 % DOX. While in vivo, it remains a higher absorption ability to DOX when the scaffold is successfully implanted into the common jugular vein of rabbits. What's more, the scaffold has good hemocompatibility and biocompatibility, indicating its safety for in vivo application. Taken together, the 3D-printed scaffold with excellent capture of chemotherapy drugs will play an important role in reducing the toxic side effects of chemotherapy drugs and improving the life quality of patients.


Assuntos
Poliésteres , Polímeros , Animais , Coelhos , Poliésteres/farmacologia , Doxorrubicina/farmacologia , DNA , Impressão Tridimensional , Alicerces Teciduais , Engenharia Tecidual/métodos
13.
Nat Commun ; 14(1): 5901, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37737235

RESUMO

Many orphan G protein-coupled receptors (GPCRs) remain understudied because their endogenous ligands are unknown. Here, we show that a group of class A/rhodopsin-like orphan GPCRs including GPR61, GPR161 and GPR174 increase the cAMP level similarly to fully activated D1 dopamine receptor (D1R). We report cryo-electron microscopy structures of the GPR61‒Gs, GPR161‒Gs and GPR174‒Gs complexes without any exogenous ligands. The GPR174 structure reveals that endogenous lysophosphatidylserine (lysoPS) is copurified. While GPR174 fails to respond to exogenous lysoPS, likely owing to its maximal activation by the endogenous ligand, GPR174 mutants with lower ligand binding affinities can be specifically activated by lysoPS but not other lipids, in a dose-dependent manner. Moreover, GPR174 adopts a non-canonical Gs coupling mode. The structures of GPR161 and GPR61 reveal that the second extracellular loop (ECL2) penetrates into the orthosteric pocket, possibly contributing to constitutive activity. Our work definitively confirms lysoPS as an endogenous GPR174 ligand and suggests that high constitutive activity of some orphan GPCRs could be accounted for by their having naturally abundant ligands.


Assuntos
Receptores de Dopamina D1 , Transdução de Sinais , Ligantes , Microscopia Crioeletrônica
14.
Front Public Health ; 11: 1128008, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37124794

RESUMO

Objective: The objective of this study is to conduct a comprehensive bibliometric analysis to identify and evaluate global trends in diabetic retinopathy (DR) research and visualize the focus and frontiers of this field. Methods: Diabetic retinopathy-related publications from the establishment of the Web of Science (WOS) through 1 November 2022 were retrieved for qualitative and quantitative analyses. This study analyzed annual publication counts, prolific countries, institutions, journals, and the top 10 most cited literature. The findings were presented through descriptive statistics. VOSviewer 1.6.17 was used to exhibit keywords with high frequency and national cooperation networks, while CiteSpace 5.5.R2 displayed the timeline and burst keywords for each term. Results: A total of 10,709 references were analyzed, and the number of publications continuously increased over the investigated period. America had the highest h-index and citation frequency, contributing to the most influence. China was the most prolific country, producing 3,168 articles. The University of London had the highest productivity. The top three productive journals were from America, and Investigative Ophthalmology Visual Science had the highest number of publications. The article from Gulshan et al. (2016; co-citation counts, 2,897) served as the representative and symbolic reference. The main research topics in this area were incidence, pathogenesis, treatment, and artificial intelligence (AI). Deep learning, models, biomarkers, and optical coherence tomography angiography (OCTA) of DR were frontier hotspots. Conclusion: Bibliometric analysis in this study provided valuable insights into global trends in DR research frontiers. Four key study directions and three research frontiers were extracted from the extensive DR-related literature. As the incidence of DR continues to increase, DR prevention and treatment have become a pressing public health concern and a significant area of research interest. In addition, the development of AI technologies and telemedicine has emerged as promising research frontiers for balancing the number of doctors and patients.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Oftalmologia , Humanos , Inteligência Artificial , Bibliometria , China
15.
Front Microbiol ; 14: 1144328, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37206330

RESUMO

Background: Alkaloids are the second primary class of secondary metabolites (SMs) from marine organisms, most of which have antioxidant, antitumor, antibacterial, anti-inflammatory, and other activities. However, the SMs obtained by traditional isolation strategies have drawbacks such as highly reduplication and weak bioactivity. Therefore, it is significantly important to establish an efficient strategy for screening strains and mining novel compounds. Methods: In this study, we utilized in situ colony assay combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the strain with high potential in alkaloids production. The strain was identified by genetic marker genes and morphological analysis. The secondary metabolites from the strain were isolated by the combine use of vacuum liquid chromatography (VLC), ODS column chromatography, and Sephadex LH-20. Their structures were elucidated by 1D/2D NMR, HR-ESI-MS, and other spectroscopic technologies. Finally, these compounds bioactivity were assay, including anti-inflammatory and anti-ß aggregation. Results: Eighteen marine fungi were preliminarily screened for alkaloids production by in situ colony assay using Dragendorff reagent as dye, and nine of them turned orange, which indicated abundant alkaloids. By thin-layer chromatography (TLC), LC-MS/MS, and multiple approaches assisted Feature-Based Molecular Networking (FBMN) analysis of fermentation extracts, a strain ACD-5 (Penicillium mallochii with GenBank accession number OM368350) from sea cucumber gut was selected for its diverse alkaloids profiles especially azaphilones. In bioassays, the crude extracts of ACD-5 in Czapek-dox broth and brown rice medium showed moderate antioxidant, acetylcholinesterase inhibitory, anti-neuroinflammatory, and anti-ß aggregation activities. Three chlorinated azaphilone alkaloids, compounds 1-3 (sclerotioramine, isochromophilone VI, and isochromophilone IX, respectively), were isolated from the fermentation products of ACD-5 in brown rice medium guided by bioactivities and mass spectrometry analysis. Compound 1 had shown remarkable anti-neuroinflammatory activity in liposaccharide induced BV-2 cells. Conclusion: In summary, in situ colony screening together with LC-MS/MS, multi-approach assisted FBMN can act as an efficient screening method for strains with potential in alkaloids production.

16.
Plants (Basel) ; 11(15)2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35956514

RESUMO

Grassland is the primary land use in China, which has experienced extensive degradation in recent decades due to overexploitation. Here, we conducted field experiments to quantify the degraded grassland's recovery rate in Northeast Inner Mongolia in response to restoration measures, including fallow + enclosure (FE) and mowing + enclosure (ME) in comparison to livestock grazing (LG), since 2005. Plant community properties were surveyed and aboveground biomass (AGB) sampled in summer 2013. Our results showed that the regional dominant species Leymus chinensis retained its dominance under FE, whereas a range of forb species gained dominance under LG. Vegetative cover was maximal under FE and minimal under LG. The least amount of vegetation development and AGB were observed under LG. However, plant diversity showed an opposite pattern, with maximal diversity under LG and minimal under FE. Statistical analysis revealed that AGB was negatively associated with plant diversity for all treatments except ME. For ME, a positive AGB-diversity relationship was characterized, suggesting that mowing intensity was a controlling factor for the AGB-diversity relationship. Overall, these results demonstrated that enclosure plus mowing represented an effective conservation measure that provided fair support to forage production and a progressive pathway to a more resilient grassland system.

17.
Front Immunol ; 13: 1014333, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189290

RESUMO

Background: Immunotherapy has gradually become an important therapy option for lung cancer patients. Methods: The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were responsible for all the public data. Results: In our study, we firstly identified 22 characteristic genes of NSCLC immunotherapy response using the machine learning algorithm. Molecule subtyping was then conducted and two patient subtypes were identified Cluster1 and Cluster2. Results showed that Cluster1 patients had a lower TIDE score and were more sensitive to immunotherapy in both TCGA and combined GEO cohorts. Biological enrichment analysis showed that pathways of epithelial-mesenchymal transition (EMT), apical junction, KRAS signaling, myogenesis, G2M checkpoint, E2F targets, WNT/ß-catenin signaling, hedgehog signaling, hypoxia were activated in Cluster2 patients. Genomic instability between Cluster1 and Cluster2 patients was not significantly different. Interestingly, we found that female patients were more adaptable to immunotherapy. Biological enrichment revealed that compared with female patients, pathways of MYC target, G2M checkpoints, mTORC1 signaling, MYC target, E2F target, KRAS signaling, oxidative phosphorylation, mitotic spindle and P53 pathway were activated. Meanwhile, monocytes might have a potential role in affecting NSCLC immunotherapy and underlying mechanism has been explored. Finally, we found that SEC14L3 and APCDD1L were the underlying targets affecting immunotherapy, as well as patients survival. Conclusions: These results can provide direction and guidance for future research focused on NSCLC immunotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Feminino , Proteínas Hedgehog/metabolismo , Humanos , Imunoterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/terapia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Proteína Supressora de Tumor p53/genética , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismo
18.
Front Plant Sci ; 13: 1019966, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36479515

RESUMO

Introduction: Grasslands are the most important land use in China and have experienced extensive degradation in the past few decades due to overgrazing. However, regionally viable solutions to grazing intensity alleviation remained elusive to date. Methods: Here, we evaluated the grazing intensity effects of sown alfalfa pastures in northern China using an experiment-modeling combined approach that involved six sites in field experiments and five provinces in DNDC modeling of sown alfalfa pasture's forage production and carbon sequestration potentials in marginal lands. Results: Our results showed that the sown alfalfa pasture's dry-matter yield varied between 4.5 and 9.0 Mg ha-1 under rainfed and irrigated conditions, respectively, from 2025 to 2035. If half of the available marginal lands were mobilized for alfalfa forage production, these yield levels meant that livestock grazing intensity on natural grasslands may drop 8-13% under rainfed and 20-33% under irrigated conditions. Our results also showed that marginal land's soil organic carbon contents were systematically higher under sown alfalfa pasture than under fallow management by a big margin of 8.5 and 9.9 g kg-1 (i.e., +79 and +95%), under rainfed and irrigated conditions, respectively, during 2025-2035. Discussion: Overall, these results demonstrated that sown alfalfa pasture on marginal lands represents an effective grassland conservation pathway over the short- to medium-term time horizon based on current technologies.

19.
Nat Commun ; 13(1): 3186, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676276

RESUMO

Dopamine receptors are widely distributed in the central nervous system and are important therapeutic targets for treatment of various psychiatric and neurological diseases. Here, we report three cryo-electron microscopy structures of the D1 dopamine receptor (D1R)-Gs complex bound to two agonists, fenoldopam and tavapadon, and a positive allosteric modulator LY3154207. The structure reveals unusual binding of two fenoldopam molecules, one to the orthosteric binding pocket (OBP) and the other to the extended binding pocket (EBP). In contrast, one elongated tavapadon molecule binds to D1R, extending from OBP to EBP. Moreover, LY3154207 stabilizes the second intracellular loop of D1R in an alpha helical conformation to efficiently engage the G protein. Through a combination of biochemical, biophysical and cellular assays, we further show that the broad conformation stabilized by two fenoldopam molecules and interaction between TM5 and the agonist are important for biased signaling of D1R.


Assuntos
Dopamina , Fenoldopam , Microscopia Crioeletrônica , Agonistas de Dopamina/química , Agonistas de Dopamina/farmacologia , Ligantes , Receptores de Dopamina D1/metabolismo
20.
Front Plant Sci ; 13: 985864, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36247641

RESUMO

Grassland is the primary land use in China but has experienced severe degradation in recent decades due to overgrazing and conversion to agricultural production. Here, we conducted a field experiment in northeastern Inner Mongolia to test the effectiveness of sown pastures in lowering the grazing pressure on grasslands and raising the quality of marginal soils. Alfalfa and smooth bromegrass monocultures and mixture were sown in a marginal cropland field in Hulunber in June 2016. Biomass productivity, soil physicochemical, and biological properties were monitored annually from 2016 to 2020. The results showed that the marginal cropland soil responded consistently positively to sown pastures for major soil properties. Soil organic carbon (SOC) and total nitrogen (TN) increased by 48 and 21%, respectively, from 2016 to 2020 over the 0-60 cm soil depth range. Soil microbes responded proactively too. The soil microbial biomass C (SMBC) and N (SMBN) increased by 117 and 39%, respectively, during the period of 2016-2020. However, by the end of the experiment, the soil of a natural grassland field, which was included in the experiment as a control, led the sown pasture soil by 28% for SOC, 35% for TN, 66% for SMBC, and 96% for SMBN. Nevertheless, the natural grassland soil's productive capacity was inferior to that of the sown pasture soil. The average aboveground biomass productivity of sown pastures was measured at 8.4 Mg ha-1 in 2020, compared to 5.0 Mg ha-1 for natural grassland, while the root biomass of sown pastures was averaged at 7.5 Mg ha-1, leading the natural grassland by 15%. Our analyses also showed that the sown pastures' biomass productivity advantage had a much-neglected potential in natural grassland protection. If 50% of the available marginal cropland resources in Hulunber under the current environmental protection law were used for sown pastures, the livestock grazing pressure on the natural grasslands would decrease by a big margin of 38%. Overall, these results represent systematic empirical and analytical evidence of marginal cropland soil's positive responses to sown pastures, which shows clearly that sown pasture is a valid measure both for soil rehabilitation and biomass production.

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