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1.
Mol Cell ; 81(22): 4605-4621.e11, 2021 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-34582793

RESUMEN

G-protein-coupled receptors (GPCRs), also known as seven transmembrane receptors (7TMRs), typically interact with two distinct signal-transducers, i.e., G proteins and ß-arrestins (ßarrs). Interestingly, there are some non-canonical 7TMRs that lack G protein coupling but interact with ßarrs, although an understanding of their transducer coupling preference, downstream signaling, and structural mechanism remains elusive. Here, we characterize two such non-canonical 7TMRs, namely, the decoy D6 receptor (D6R) and the complement C5a receptor subtype 2 (C5aR2), in parallel with their canonical GPCR counterparts. We discover that D6R and C5aR2 efficiently couple to ßarrs, exhibit distinct engagement of GPCR kinases (GRKs), and activate non-canonical downstream signaling pathways. We also observe that ßarrs adopt distinct conformations for D6R and C5aR2, compared to their canonical GPCR counterparts, in response to common natural agonists. Our study establishes D6R and C5aR2 as ßarr-coupled 7TMRs and provides key insights into their regulation and signaling with direct implication for biased agonism.


Asunto(s)
Membrana Celular/metabolismo , Conformación Proteica , Transducción de Señal , beta-Arrestinas/química , Animales , Proteínas de Unión al GTP/química , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Unión Proteica , Dominios Proteicos , Estructura Secundaria de Proteína , Transporte de Proteínas , Receptor de Anafilatoxina C5a/metabolismo
2.
J Biol Chem ; 298(9): 102294, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35872018

RESUMEN

Promiscuous G protein-coupled receptors (GPCRs) engage multiple Gα subtypes with different efficacies to propagate signals in cells. A mechanistic understanding of Gα selectivity by GPCRs is critical for therapeutic design, since signaling can be restrained by ligand-receptor complexes to preferentially engage specific G proteins. However, details of GPCR selectivity are unresolved. Here, we investigated cognate G protein selectivity using the prototypical promiscuous Gαq/11 and Gα12/13 coupling receptors, angiotensin II type I receptor (AT1R) and prostaglandin F2α receptor (FP), bioluminescence resonance energy transfer-based G protein and pathway-selective sensors, and G protein knockout cells. We determined that competition between G proteins for receptor binding occurred in a receptor- and G protein-specific manner for AT1R and FP but not for other receptors tested. In addition, we show that while Gα12/13 competes with Gαq/11 for AT1R coupling, the opposite occurs for FP, and Gαq-mediated signaling regulated G protein coupling only at AT1R. In cells, the functional modulation of biased ligands at FP and AT1R was contingent upon cognate Gα availability. The efficacy of AT1R-biased ligands, which poorly signal through Gαq/11, increased in the absence of Gα12/13. Finally, we show that a positive allosteric modulator of Gαq/11 signaling that also allosterically decreases FP-Gα12/13 coupling, lost its negative modulation in the absence of Gαq/11 coupling to FP. Together, our findings suggest that despite preferential binding of similar subsets of G proteins, GPCRs follow distinct selectivity rules, which may contribute to the regulation of ligand-mediated G protein bias of AT1R and FP.


Asunto(s)
Subunidades alfa de la Proteína de Unión al GTP G12-G13 , Subunidades alfa de la Proteína de Unión al GTP Gq-G11 , Receptor de Angiotensina Tipo 1 , Receptores de Prostaglandina , Subunidades alfa de la Proteína de Unión al GTP G12-G13/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Células HEK293 , Humanos , Ligandos , Receptor de Angiotensina Tipo 1/metabolismo , Receptores de Prostaglandina/metabolismo
3.
Int J Cancer ; 153(3): 552-570, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37140208

RESUMEN

Although KMT2D, also known as MLL2, is known to play an essential role in development, differentiation, and tumor suppression, its role in pancreatic cancer development is not well understood. Here, we discovered a novel signaling axis mediated by KMT2D, which links TGF-ß to the activin A pathway. We found that TGF-ß upregulates a microRNA, miR-147b, which in turn leads to post-transcriptional silencing of KMT2D. Loss of KMT2D induces the expression and secretion of activin A, which activates a noncanonical p38 MAPK-mediated pathway to modulate cancer cell plasticity, promote a mesenchymal phenotype, and enhance tumor invasion and metastasis in mice. We observed a decreased KMT2D expression in human primary and metastatic pancreatic cancer. Furthermore, inhibition or knockdown of activin A reversed the protumoral role of KMT2D loss. These findings support a tumor-suppressive role of KMT2D in pancreatic cancer and identify miR-147b and activin A as novel therapeutic targets.


Asunto(s)
MicroARNs , Neoplasias Pancreáticas , Humanos , Animales , Ratones , Plasticidad de la Célula , Línea Celular Tumoral , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Pancreáticas/patología , Factor de Crecimiento Transformador beta/metabolismo , Activinas/genética , Neoplasias Pancreáticas
4.
Sensors (Basel) ; 23(12)2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-37420688

RESUMEN

The potential of the Internet of Body (IoB) to support healthcare systems in the future lies in its ability to enable proactive wellness screening through the early detection and prevention of diseases. One promising technology for facilitating IoB applications is near-field inter-body coupling communication (NF-IBCC), which features lower power consumption and higher data security when compared to conventional radio frequency (RF) communication. However, designing efficient transceivers requires a profound understanding of the channel characteristics of NF-IBCC, which remain unclear due to significant differences in the magnitude and passband characteristics of existing research. In response to this problem, this paper clarifies the physical mechanisms of the differences in the magnitude and passband characteristics of NF-IBCC channel characteristics in existing research work through the core parameters that determine the gain of the NF-IBCC system. The core parameters of NF-IBCC are extracted through the combination of transfer functions, finite element simulations, and physical experiments. The core parameters include the inter-body coupling capacitance (CH), the load impedance (ZL), and the capacitance (Cair), coupled by two floating transceiver grounds. The results illustrate that CH, and particularly Cair, primarily determine the gain magnitude. Moreover, ZL mainly determines the passband characteristics of the NF-IBCC system gain. Based on these findings, we propose a simplified equivalent circuit model containing only core parameters, which can accurately capture the gain characteristics of the NF-IBCC system and help to concisely describe the channel characteristics of the system. This work lays a theoretical foundation for developing efficient and reliable NF-IBCC systems that can support IoB for early disease detection and prevention in healthcare applications. The potential benefits of IoB and NF-IBCC technology can, thus, be fully realized by developing optimized transceiver designs based on a comprehensive understanding of the channel characteristics.


Asunto(s)
Comunicación , Internet , Capacidad Eléctrica , Impedancia Eléctrica
5.
EMBO Rep ; 21(9): e49886, 2020 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-32715625

RESUMEN

ß-arrestins (ßarrs) are key regulators of G protein-coupled receptor (GPCR) signaling and trafficking, and their knockdown typically leads to a decrease in agonist-induced ERK1/2 MAP kinase activation. Interestingly, for some GPCRs, knockdown of ßarr1 augments agonist-induced ERK1/2 phosphorylation although a mechanistic basis for this intriguing phenomenon is unclear. Here, we use selected GPCRs to explore a possible correlation between the spatial positioning of receptor phosphorylation sites and the contribution of ßarr1 in ERK1/2 activation. We discover that engineering a spatially positioned double-phosphorylation-site cluster in the bradykinin receptor (B2 R), analogous to that present in the vasopressin receptor (V2 R), reverses the contribution of ßarr1 in ERK1/2 activation from inhibitory to promotive. An intrabody sensor suggests a conformational mechanism for this role reversal of ßarr1, and molecular dynamics simulation reveals a bifurcated salt bridge between this double-phosphorylation site cluster and Lys294 in the lariat loop of ßarr1, which directs the orientation of the lariat loop. Our findings provide novel insights into the opposite roles of ßarr1 in ERK1/2 activation for different GPCRs with a direct relevance to biased agonism and novel therapeutics.


Asunto(s)
Sistema de Señalización de MAP Quinasas , Receptores Acoplados a Proteínas G , Células HEK293 , Humanos , Fosforilación , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , beta-Arrestina 1/metabolismo , beta-Arrestinas/metabolismo
6.
J Biol Chem ; 295(38): 13169-13180, 2020 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-32703898

RESUMEN

The angiotensin II (AngII) type 1 receptor (AT1R), a member of the G protein-coupled receptor (GPCR) family, signals through G proteins and ß-arrestins, which act as adaptors to regulate AT1R internalization and mitogen-activated protein kinase (MAPK) ERK1/2 activation. ß-arrestin-dependent ERK1/2 regulation is the subject of important studies because its spatiotemporal control remains poorly understood for many GPCRs, including AT1R. To study the link between ß-arrestin-dependent trafficking and ERK1/2 signaling, we investigated three naturally occurring AT1R variants that show distinct receptor-ß-arrestin interactions: A163T, T282M, and C289W. Using bioluminescence resonance energy transfer (BRET)-based and conformational fluorescein arsenical hairpin-BRET sensors coupled with high-resolution fluorescence microscopy, we show that all AT1R variants form complexes with ß-arrestin2 at the plasma membrane and efficiently internalize into endosomes upon AngII stimulation. However, mutant receptors imposed distinct conformations in ß-arrestin2 and differentially impacted endosomal trafficking and MAPK signaling. Notably, T282M accumulated in endosomes, but its ability to form stable complexes following internalization was reduced, markedly impairing its ability to co-traffic with ß-arrestin2. We also found that despite ß-arrestin2 overexpression, T282M's and C289W's residency with ß-arrestin2 in endosomes was greatly reduced, leading to decreased ß-arrestin-dependent ERK1/2 activation, faster recycling of receptors to the plasma membrane, and impaired AngII-mediated proliferation. Our findings reveal that naturally occurring AT1R variants alter the patterns of receptor/ß-arrestin2 trafficking and suggest conformationally dependent ß-arrestin-mediated MAPK activation as well as endosomal receptor-ß-arrestin complex stabilization in the mitogenic response of AT1R.


Asunto(s)
Endosomas/metabolismo , Sistema de Señalización de MAP Quinasas , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Receptor de Angiotensina Tipo 1/metabolismo , beta-Arrestinas/metabolismo , Sustitución de Aminoácidos , Angiotensina II/farmacología , Endosomas/genética , Activación Enzimática , Células HEK293 , Humanos , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Mutación Missense , Receptor de Angiotensina Tipo 1/genética , beta-Arrestinas/genética
7.
Prostate ; 81(14): 1071-1077, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34320230

RESUMEN

BACKGROUND: The 2008 and 2012 United States Preventive Services Task Force (USPSTF) recommendations against prostate-specific antigen (PSA) screening have led to changes in the incidence pattern of prostate cancer. We sought to examine rates and trends in stage-specific prostate cancer incidence by age and race/ethnicity using the most recent data obtained from Surveillance, Epidemiology, and End Results (SEER) program. METHODS: SEER*Stat version 8.3.6 was used to analyze annual prostate cancer incidence rates between 2000 and 2017 according to the SEER summary stage, age group, and race/ethnicity group. Incidence rates per 100,000 men were calculated and age-adjusted to 2000 US standard population. Annual percentage change (APC) was performed to identify the trend in prostate cancer incidence. RESULTS: Between 2008 and 2012, trends in incidence of overall and localized prostate cancer significantly declined in comparison with between 2000 and 2007 (APC, -5.4 and -6.0, respectively). However, there was an increase in the incidence rate of both overall and localized prostate cancer from 2014 to 2017 (43.3-46 and 34-34.9 per 100,000 men, respectively). The incidence of regional prostate cancer significantly increased between 2013 and 2017 (5.9-6.8 per 100,000 men; APC, 4.3). Distant disease incidence increased continually between 2008 and 2012 (2.9-3.3 per 100,000 men; APC, 2.3) and between 2013 and 2017 (3.4-4.3 per 100,000 men; APC, 6.0). In addition, these increases in incidence occurred in men of all stratified age and race/ethnicity groups, except for men aged <50 years and American Indian/Alaska Native men. CONCLUSION: This study demonstrates that the longer-term effects of USPSTF recommendations against PSA screening may have resulted in a reversal of downtrend in prostate cancer incidence, as incidence rates of overall and localized prostate cancer gradually increased from 2014 to 2017. Meanwhile, the trend in stage migration toward advanced disease increased incrementally.


Asunto(s)
Neoplasias de la Próstata/epidemiología , Factores de Edad , Anciano , Detección Precoz del Cáncer , Etnicidad , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/diagnóstico , Grupos Raciales , Factores de Riesgo , Programa de VERF
8.
J Biol Chem ; 294(46): 17409-17420, 2019 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-31530642

RESUMEN

The angiotensin II (AngII) type 1 receptor (AT1R) is a member of the G protein-coupled receptor (GPCR) family and binds ß-arrestins (ß-arrs), which regulate AT1R signaling and trafficking. These processes can be biased by different ligands or mutations in the AGTR1 gene. As for many GPCRs, the exact details for AT1R-ß-arr interactions driven by AngII or ß-arr-biased ligands remain largely unknown. Here, we used the amber-suppression technology to site-specifically introduce the unnatural amino acid (UAA) p-azido-l-phenylalanine (azF) into the intracellular loops (ICLs) and the C-tail of AT1R. Our goal was to generate competent photoreactive receptors that can be cross-linked to ß-arrs in cells. We performed UV-mediated photolysis of 25 different azF-labeled AT1Rs to cross-link ß-arr1 to AngII-bound receptors, enabling us to map important contact sites in the C-tail and in the ICL2 and ICL3 of the receptor. The extent of AT1R-ß-arr1 cross-linking among azF-labeled receptors differed, revealing variability in ß-arr's contact mode with the different AT1R domains. Moreover, the signature of ligated AT1R-ß-arr complexes from a subset of azF-labeled receptors also differed between AngII and ß-arr-biased ligand stimulation of receptors and between azF-labeled AT1R bearing and that lacking a bias signaling mutation. These observations further implied distinct interaction modalities of the AT1R-ß-arr1 complex in biased signaling conditions. Our findings demonstrate that this photocross-linking approach is useful for understanding GPCR-ß-arr complexes in different activation states and could be extended to study other protein-protein interactions in cells.


Asunto(s)
Receptor de Angiotensina Tipo 1/metabolismo , beta-Arrestina 1/metabolismo , Código Genético , Células HEK293 , Humanos , Luz , Unión Proteica , Mapas de Interacción de Proteínas , Receptor de Angiotensina Tipo 1/genética
9.
J Environ Manage ; 264: 110454, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32250891

RESUMEN

Manure acidification is recommended to minimize ammonia (NH3) emission at storage. However, the potential for acidification to mitigate NH3 emission from storage and the impact of manure acidification (pH range 5-8) on composting have been poorly studied. The effects of manure acidification at storage on the subsequent composting process, nutrient balance, gaseous emissions and product quality were assessed through an analysis of literature data and an experiment under controlled conditions. Results of the data mining showed that mineral acids, acidic salts and organic acids significantly reduced NH3 emission, however, a weaker effect was observed for organic acids. A subsequent composting experiment showed that using manure acidified to pH5 or pH6 as feedstock delayed organic matter degradation for 7-10 days, although pH6 had no negative effect on compost maturity. Acidification significantly decreased NH3 emission from both storage and composting, however, excessive acidification (pH5) enhanced N2O emissions (18.6%) during composting. When manure was acidified to pH6, N2O (17.6%) and CH4 (20%) emissions, and total GHG emissions expressed as global warming potential (GWP) (9.6%) were reduced during composting. Acidification of manure before composting conserved more N as NH4+ and NOx- in compost product. Compared to the control, the labile, plant-available phosphorus (P) content in the compost product, predominately as water-soluble inorganic P, increased with manure acidification to pH5 and pH6. Acidification of manure to pH6 before composting decreases nutrient losses and gaseous emissions without decreasing the quality of the compost product. The techno-economic advantages of acidification should be further ascertained.


Asunto(s)
Compostaje , Amoníaco , Gases , Concentración de Iones de Hidrógeno , Estiércol , Metano , Nitrógeno , Nutrientes , Suelo
10.
Tumour Biol ; 36(7): 5607-15, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25701378

RESUMEN

Mammalian target of rapamycin (mTOR) has emerged as a new potential therapeutic target for gastric cancer. However, a phase III clinical trial found that monotherapy with the mTOR inhibitor everolimus did not significantly improve the overall survival of patients with advanced gastric cancer. This has led to the exploration of more effective combinatorial regimens to enhance the effectiveness of mTOR inhibitors. Here, we demonstrate that Akt phosphorylation is increased in the rapamycin-resistant gastric cancer cell lines MGC803 and SGC7901. We further show that combined treatment with celecoxib and rapamycin results in an additive inhibitory effect on the growth of gastric cancer cells through suppression of rapamycin-induced Akt activation. Moreover, celecoxib upregulated the expression of the ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b). Knockdown of Cbl-b significantly attenuated celecoxib-mediated inhibition of Akt phosphorylation and impaired the additive anticancer effect of celecoxib and rapamycin. Our results suggest that celecoxib-mediated upregulation of Cbl-b is responsible, at least in part, for the additive antitumor effect of celecoxib and rapamycin via inhibition of rapamycin-induced Akt activation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-cbl/genética , Pirazoles/administración & dosificación , Neoplasias Gástricas/tratamiento farmacológico , Sulfonamidas/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Celecoxib , Línea Celular Tumoral , Ciclooxigenasa 2/biosíntesis , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Técnicas de Silenciamiento del Gen , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Sirolimus/administración & dosificación , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Serina-Treonina Quinasas TOR/biosíntesis
11.
Nutr Res ; 123: 111-119, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38310647

RESUMEN

Chaenomeles sinensis (Thouin) Koehne fruit is a rich source of medicinally and nutritionally important natural phytochemicals that benefit human health. Based on the information provided, we hypothesized that Chaenomeles sinensis (Thouin) Koehne fruit polyphenols (CSFP) possessed in vivo protective effect of on high-fat diet (HFD)-induced obesity and hepatic steatosis. Specific pathogen-free male C57BL/6J mice were randomly divided into 3 groups and fed with a low-fat diet, HFD, or HFD supplemented with CSFP by intragastric administration for 14 weeks. Obesity-related biochemical indexes and hepatic gene expression profile were determined. The findings of this study demonstrated notable reductions in body weight gain, serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, and steatosis grade in the group supplemented with CSFP compared with the HFD group. Gene expression analysis provided insights into the molecular mechanisms, demonstrating that CSFP downregulated the expression of key genes involved in lipogenesis (e.g., Fas, Fads2, Scd1) and upregulated the genes associated with fatty acid oxidation (e.g., Pparα, Cpt1a, Acox1), while also suppressing genes implicated in cholesterol homeostasis (e.g., HMGCoR, Insig1, AdipoR2). These molecular changes suggest that CSFP exerts protective effects by modulating hepatic lipid metabolism pathways, thereby mitigating the metabolic derangements associated with HFD-induced obesity and hepatic steatosis.


Asunto(s)
Hígado Graso , Rosaceae , Humanos , Masculino , Ratones , Animales , Metabolismo de los Lípidos , Dieta Alta en Grasa/efectos adversos , Frutas/química , Polifenoles/farmacología , Polifenoles/uso terapéutico , Polifenoles/análisis , Ratones Endogámicos C57BL , Hígado Graso/etiología , Hígado Graso/prevención & control , Hígado Graso/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/etiología , Obesidad/metabolismo , Hígado/metabolismo , Colesterol
12.
Int J Biol Macromol ; 264(Pt 1): 130535, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38432277

RESUMEN

This study investigated the molecular mechanism underlying the binding interaction between apigenin (API) and α-glucosidase (α-glu) by a combination of experimental techniques and computational simulation strategies. The spontaneously formation of stable API-α-glu complex was mainly driven by hydrogen bonds and hydrophobic forces, leading to a static fluorescence quenching of α-glu. The binding of API induced secondary structure and conformation changes of α-glu, decreasing the surface hydrophobicity of protein. Computational simulation results demonstrated that API could bind into the active cavity of α-glu via its interaction with active residues at the binding site. The important roles of key residues responsible for the binding stability and affinity between API and α-glu were further revealed by MM/PBSA results. In addition, it can be found that the entrance of active site tended to close after API binding as a result of its interaction with gate keeping residues. Furthermore, the structural basis for the binding interaction behavior of API was revealed and visualized by weak interaction analysis. The findings of our study revealed atomic-level mechanism of the interaction between API, which might shed light on the development of better inhibitors.


Asunto(s)
Apigenina , alfa-Glucosidasas , alfa-Glucosidasas/metabolismo , Inhibidores de Glicósido Hidrolasas/química , Simulación del Acoplamiento Molecular , Análisis Espectral , Sitios de Unión , Unión Proteica , Termodinámica
13.
Artículo en Inglés | MEDLINE | ID: mdl-38329671

RESUMEN

With the increase of organic solid wastes (OSWs), current waste management practices, such as landfill, incineration, and windrow composting, have shown weaknesses in both resource recycling and environmental protection. Co-composting has been used to achieve nutrient and carbon recycling but is accused of high ammonia emission and low degradation efficiency. Therefore, this study developed a precision co-composting strategy (S3, which adds functional bacteria generated from food processing waste to a co-composting system) and compared it with the current OSW treatment strategy (S1) and traditional co-composting strategy (S2) from a life cycle assessment (LCA) perspective. The results showed that compared with S1, the eco-efficiency increased by 31.3% due to the higher economic profit of S2 but did not directly reduce the environmental cost. The addition of bacterial agents reduced ammonia emissions and shortened composting time, so compared with S1 and S2, the environmental cost of S3 was reduced by 37.9 and 43.6%, while the economic profit increased by 79.8 and 24.4%, respectively. The changes in environmental costs and economic benefits resulted in a huge improvement of S3's eco-efficiency, which was 189.6 and 121.7% higher than S1 and S2. Meanwhile, the adoption of S3 at a national scale in China could reduce the emission of 1,4-dichlorobenzene by 99.9% compared with S1 and increase profits by 6.58 billion USD per year. This study proposes a novel approach that exhibits high eco-efficiency in the treatment of OSWs.

14.
Waste Manag ; 182: 197-206, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38670003

RESUMEN

The significant increase in antibiotic resistance genes (ARGs) in organic solid wastes (OSWs) has emerged as a major threat to the food chain. Aerobic composting is a widely used technology for OSW management, with the potential to influence the fate of AGRs. However, the variability of the ARG elimination effects reported in different studies has highlighted the uncertainty regarding the effects of composting on ARGs. To identify the potential of composting in reducing ARG and the factors (e.g., composting technologies and physiochemical properties) influence ARG changes, a meta-analysis was conducted with a database including 4,232 observations. The abundances of ARGs and mobile genetic elements (MGEs) can be substantially reduced by 74.3% and 78.8%, respectively, via aerobic composting. During composting, the ARG levels in chicken and swine manure tended to be reduced more significantly (81.7% and 78.0%) compared to those in cattle manure (52.3%) and sewage sludge (32.6%). The reduction rate of sulfonamide resistant genes was only 35.3%, which was much lower than those of other types. MGEs and composting duration (CD) were identified as the most important factors driving ARG changes during composting. These findings provide a comprehensive insight into the effects of composting on ARG reduction, which may help prevent the transmission in food systems.


Asunto(s)
Compostaje , Farmacorresistencia Microbiana , Estiércol , Compostaje/métodos , Farmacorresistencia Microbiana/genética , Estiércol/microbiología , Animales , Aerobiosis , Residuos Sólidos/análisis , Bovinos , Pollos , Genes Bacterianos , Antibacterianos , Eliminación de Residuos/métodos , Porcinos
15.
Sci Total Environ ; 857(Pt 2): 159177, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36195138

RESUMEN

Closing the carbon (C) and nitrogen (N) balance has yet to be achieved in aerobic bioprocess due to current methodological drawbacks in the frequency of sampling and detection and the challenge in direct measurement of instantaneous N2 emission. To address this issue, a novel system was developed enabling simultaneous and online determination of gaseous C and N species (N2, N2O, NO, NH3, CO2 and CH4) from aerobic composting at a high frequency of 120 times·d-1. A helium­oxygen gas mixture was used to replace the air in the system to enable direct measurement of N2 emission, and three different gas exchange methods were assessed in their ability to minimize atmospheric background N2: 1) the N2-free gas purging method; 2) one cycle of the evacuation-refilling procedure; 3) one cycle of evacuating and refilling followed by N2-free gas purging. Method 3 was demonstrated as an optimum N2-removal method, and background N2 concentrations decreased to ~66 µmol·mol-1 within 11.6 h. During the N2-free gas purging period, low temperature incubation at 15 °C reduced CO2, CH4, NO, N2O and NH3 losses by 80.5 %, 41-fold, 10-fold, 11,403-fold and 61.4 %, respectively, compared with incubation at 30 °C. Therefore, a fast and low-perturbation N2 removal method was developed, namely the evacuating/refilling-low temperature purging method. Notably, all C and N gases exhibited large within-day variations during the peak emission period, which can be addressed by high-frequency measurement. Based on the developed method, up to 97.8 % of gaseous C and 95.6 % of gaseous N losses were quantified over a 43-day compost incubation, with N2 emission accounting (on average) for 5.8 % of the initial total N. This system for high frequency measurement of multiple gases (including N2) provides a novel tool for obtaining a deeper understanding of C and N turnover and more accurate estimation of reactive N and greenhouse gas emissions during composting.


Asunto(s)
Compostaje , Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Metano/análisis , Gases de Efecto Invernadero/análisis , Gases
16.
Bioresour Technol ; 388: 129772, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37734484

RESUMEN

To investigate the mechanisms underlying effects of biochar and calcium carbonate (CaCO3) addition on nitrous oxide (N2O) emissions during composting, this paper conducted a systematic study on mineral nitrogen (N), dissolved organic carbon (C) and N, sources of N2O, and functional genes. Biochar and CaCO3 addition decreased N2O emissions by 26.5-47.8% (9.5-96.9 mg N kg-1 dw) and 13.9-37.4% (12.0-121.0 mg N kg-1 dw) compared to the control (14.3-179.7 mg N kg-1 dw), respectively. The mitigation of N2O emission was caused by decreased contribution of ammonia-oxidizing bacteria (AOB) and fungi to N2O production due to diminished AOB amoA, fungal nirK and P450 gene abundances, or by stimulated N2O reduction to N2 owing to increased abundances of nosZⅠ and nosZⅠⅠ genes under biochar and CaCO3 addition. The findings suggest that the addition of biochar or CaCO3 is effective in mitigating N2O emission during composting.


Asunto(s)
Betaproteobacteria , Compostaje , Óxido Nitroso/análisis , Suelo , Carbonato de Calcio , Microbiología del Suelo , Carbón Orgánico
17.
Sci Signal ; 16(797): eadf2173, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37552769

RESUMEN

G protein-coupled receptors engage both G proteins and ß-arrestins, and their coupling can be biased by ligands and mutations. Here, to resolve structural elements and mechanisms underlying effector coupling to the angiotensin II (AngII) type 1 receptor (AT1R), we combined alanine scanning mutagenesis of the entire sequence of the receptor with pharmacological profiling of Gαq and ß-arrestin engagement to mutant receptors and molecular dynamics simulations. We showed that Gαq coupling to AT1R involved a large number of residues spread across the receptor, whereas fewer structural regions of the receptor contributed to ß-arrestin coupling regulation. Residue stretches in transmembrane domain 4 conferred ß-arrestin bias and represented an important structural element in AT1R for functional selectivity. Furthermore, we identified allosteric small-molecule binding sites that were enclosed by communities of residues that produced biased signaling when mutated. Last, we showed that allosteric communication within AT1R emanating from the Gαq coupling site spread beyond the orthosteric AngII-binding site and across different regions of the receptor, including currently unresolved structural regions. Our findings reveal structural elements and mechanisms within AT1R that bias Gαq and ß-arrestin coupling and that could be harnessed to design biased receptors for research purposes and to develop allosteric modulators.


Asunto(s)
Receptor de Angiotensina Tipo 1 , Transducción de Señal , beta-Arrestinas/genética , beta-Arrestinas/metabolismo , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 1/metabolismo , beta-Arrestina 1/metabolismo , Proteínas de Unión al GTP/metabolismo , Angiotensina II/metabolismo
18.
Nat Commun ; 14(1): 4808, 2023 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-37558722

RESUMEN

Chemokine receptors constitute an important subfamily of G protein-coupled receptors (GPCRs), and they are critically involved in a broad range of immune response mechanisms. Ligand promiscuity among these receptors makes them an interesting target to explore multiple aspects of biased agonism. Here, we comprehensively characterize two chemokine receptors namely, CXCR4 and CXCR7, in terms of their transducer-coupling and downstream signaling upon their stimulation by a common chemokine agonist, CXCL12, and a small molecule agonist, VUF11207. We observe that CXCR7 lacks G-protein-coupling while maintaining robust ßarr recruitment with a major contribution of GRK5/6. On the other hand, CXCR4 displays robust G-protein activation as expected but exhibits significantly reduced ßarr-coupling compared to CXCR7. These two receptors induce distinct ßarr conformations even when activated by the same agonist, and CXCR7, unlike CXCR4, fails to activate ERK1/2 MAP kinase. We also identify a key contribution of a single phosphorylation site in CXCR7 for ßarr recruitment and endosomal localization. Our study provides molecular insights into intrinsic-bias encoded in the CXCR4-CXCR7 system with broad implications for drug discovery.


Asunto(s)
Receptores CXCR , Receptores CXCR/genética , Receptores CXCR/metabolismo , Receptores CXCR4/metabolismo , Transducción de Señal , Proteínas de Unión al GTP , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Quimiocina CXCL12/metabolismo
19.
Bioresour Technol ; 344(Pt A): 126194, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34710594

RESUMEN

Enhancing electron transfer through directly elevating electric potential has been verified to reduce gaseous emissions from composting. Reducing electric resistance of composting biomass might be a choice to further strengthening electron transfer. Here, the effects of chemical electrolytes addition on gaseous Nitrogen emission in electric field assistant composting were investigated. Results suggest that adding acidic electrolyte (ferric chloride) significantly reduced ammonia (NH3) emission by 72.1% but increased nitrous oxide (N2O) emission (by 24-fold) (P < 0.05), because of a dual effect on nitrifier activity: i) an elevated abundance and proportion of ammonia oxidizing bacteria Nitrosomonadaceae, and ii) delayed growth of nitrite oxidizing bacteria. Neutral and alkaline electrolytes had no negative or positive effect on N2O or NH3 emission. Hence, there is a potential trade-off between NH3 and N2O mitigation if using ferric chloride as acidic electrolyte, and electrolyte addition should aim to enhance electron production promote N2O mitigation.


Asunto(s)
Compostaje , Amoníaco/análisis , Nitritos , Nitrógeno/análisis , Óxido Nitroso/análisis , Suelo
20.
IEEE Trans Image Process ; 31: 287-300, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34855592

RESUMEN

This paper pushes the envelope on decomposing camouflaged regions in an image into meaningful components, namely, camouflaged instances. To promote the new task of camouflaged instance segmentation of in-the-wild images, we introduce a dataset, dubbed CAMO++, that extends our preliminary CAMO dataset (camouflaged object segmentation) in terms of quantity and diversity. The new dataset substantially increases the number of images with hierarchical pixel-wise ground truths. We also provide a benchmark suite for the task of camouflaged instance segmentation. In particular, we present an extensive evaluation of state-of-the-art instance segmentation methods on our newly constructed CAMO++ dataset in various scenarios. We also present a camouflage fusion learning (CFL) framework for camouflaged instance segmentation to further improve the performance of state-of-the-art methods. The dataset, model, evaluation suite, and benchmark will be made publicly available on our project page.

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