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1.
Bioorg Med Chem Lett ; 88: 129263, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37004924

RESUMEN

Glycogen synthase kinase-3ß (GSK-3ß) regulates numerous of CNS-specific signaling pathways, and is particularly implicated in various pathogenetic mechanisms of Alzheimer's disease (AD). A noninvasive method for detecting GSK-3ß in AD brains via positron emission tomography (PET) imaging could enhance the understanding of AD pathogenesis and aid in the development of AD therapeutic drugs. In this study, an array of fluorinated thiazolyl acylaminopyridines (FTAAP) targeting GSK-3ß were designed and synthesized. These compounds showed moderate to high affinities (IC50 = 6.0 - 426 nM) for GSK-3ß in vitro. A potential GSK-3ß tracer, [18F]8, was successfully radiolabeled. [18F]8 had unsatisfactory initial brain uptake despite its suitable lipophilicity, molecular size and good stability. Further structural refinement of the lead compound is needed to develop promising [18F]-labeled radiotracers for the detection of GSK-3ß in AD brains.


Asunto(s)
Enfermedad de Alzheimer , Encéfalo , Humanos , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Ligandos , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Tomografía de Emisión de Positrones/métodos , Fosforilación
2.
Bioorg Med Chem Lett ; 80: 129112, 2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36565966

RESUMEN

Cytochrome P450 1B1 (CYP1B1) is highly expressed in a variety of tumors and implicated to drug resistance. More and more researches have suggested that CYP1B1 is a new target for cancer prevention and therapy. Various CYP1B1 inhibitors with a rigid polycyclic skeleton have been developed, such as flavonoids, trans-stilbenes, and quinazolines. To obtain a new class of CYP1B1 inhibitors, we designed and synthesized a series of bentranil analogues, moreover, IC50 determinations were performed for CYP1B1 inhibition of five of these compounds and found that 6o and 6q were the best inhibitors, with IC50 values in the nM range. The selectivity index (SI) of CYP1B1 over CYP1A1 and CYP1A2 was 30-fold higher than that of α-naphthoflavone (ANF). The molecular docking results showed that compound 6q fitted better into the CYP1B1 binding site than other compounds, which was consistent with our experimental results. On the basis of 6o and 6q, it is expected to develop CYP1B1 inhibitors with stronger affinity, higher selectivity and better solubility.


Asunto(s)
Citocromo P-450 CYP1A1 , Inhibidores Enzimáticos del Citocromo P-450 , Simulación del Acoplamiento Molecular , Citocromo P-450 CYP1B1/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Sitios de Unión
3.
Bioorg Med Chem Lett ; 96: 129533, 2023 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-37865282

RESUMEN

Cytochrome P450 (CYP)1B1 has been identified to be specifically overexpressed in several solid tumors, thus it's a potential target for the detection of tumors. Based on the 2-Phenylquinazolin CYP1B1 inhibitors, we designed and synthesized several positron emission computed tomography (PET) imaging probes targeting CYP1B1. Through IC50 determinations, most of these probes exhibited good affinity and selectivity to CYP1B1. Considering their affinity, solubility, and their 18F labeling methods, we chose compound 5c as the best candidate. The 18F radiolabeling of [18F] 5c was easy to handle with good radiolabeling yield and radiochemical purity. In vitro and in vivo stability study indicated that probe [18F]5c has good stability. In cell binding assay, [18F]5c could be specifically taken up by tumor cells, especially HCT-116 cells. Although the tumor-blood (T/B) and tumor-muscle (T/M) values and PET imaging results were unsatisfied, it is still possible to develop PET probes targeting CYP1B1 by structural modification on the basis of 5c in the future.


Asunto(s)
Tomografía de Emisión de Positrones , Radiofármacos , Línea Celular Tumoral , Tomografía de Emisión de Positrones/métodos , Radiofármacos/farmacología , Radiofármacos/química , Radioisótopos de Flúor
4.
Int J Mol Sci ; 24(21)2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37958501

RESUMEN

The aim of this study was to investigate the inhibitory effects of Cordyceps militaris solid medium extract (CME) and cordycepin (COR) on LTA-induced inflammation in MH-S cells and their mechanisms of action. In this study, the establishment of an LTA-induced MH-S inflammation model was determined, the CCK-8 method was used to determine the safe concentration range for a drug for COR and CME, the optimal concentration of COR and CME to exert anti-inflammatory effects was further selected, and the expression of inflammatory factors of TNF-α, IL-1ß, IL-18, and IL-6 was detected using ELISA. The relative expression of TNF-α, IL-1ß, IL-18, IL-6, IL-10, TLR2 and MyD88 mRNA was detected using RT-PCR, and the IL-1ß, IL-18, TLR2, MyD88, NF-κB p-p65, NLRP3, pro-caspase-1, Caspase-1 and ASC protein expression in the cells were detected using Western blot; immunofluorescence assay detected the expression of Caspase-1 in MH-S cells. The results revealed that both CME and COR inhibited the levels of IL-1ß, IL-18, IL-6, and TNF-α in the supernatants of LTA-induced MH-S cells and the mRNA expression levels of IL-1ß, IL-18, IL-6, TNF-α, TLR2 and MyD88, down-regulated the LTA-induced IL-1ß, IL-18, TLR2 in MH-S cells, MyD88, NF-κB p-p65/p65, NLRP3, ASC, pro-caspase-1, and caspase-1 protein expression levels, and inhibited LTA-induced caspase-1 activation in MH-S cells. In conclusion, CME can play a therapeutic role in LTA-induced inflammation in MH-S cells via TLR2/NF-κB/NLRP3, and may serve as a potential drug for bacterial pneumonia caused by Gram-positive bacteria.


Asunto(s)
Cordyceps , FN-kappa B , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Interleucina-18/metabolismo , Cordyceps/metabolismo , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/metabolismo , Caspasa 1/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , ARN Mensajero
5.
Mol Imaging ; 2022: 2679260, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35330799

RESUMEN

[18F]tetrafluoroborate (TFB) has been introduced as the 18F-labeled PET imaging probe for the human sodium iodide symporter (NIS). Noninvasive NIS imaging using [18F]TFB has received much interest in recent years for evaluating various NIS-expressing tumors. Cancers are a global concern with enormous implications; therefore, improving diagnostic methods for accurate detection of cancer is extremely important. Our aim was to investigate the PET imaging capabilities of [18F]TFB in NIS-transfected lung cell line A549 and endogenous NIS-expressing tumor cells, such as thyroid cancer K1 and gastric cancer MKN45, and broaden its application in the medical field. Western blot and flow cytometry were used to assess the NIS expression level. Radioactivity counts of [18F]TFB, in vitro, in the three tumor cells were substantially higher than those in the KI inhibition group in the uptake experiment. In vivo PET imaging clearly delineated the three tumors based on the specific accumulation of [18F]TFB in a mouse model. Ex vivo biodistribution investigation showed high [18F]TFB absorption in the tumor location, which was consistent with the PET imaging results. These results support the use of NIS-transfected lung cell line A549 and NIS-expressing tumor cells MKN45 and K1, to investigate probing capabilities of [18F]TFB. We also demonstrate, for the first time, the feasibility of [18F]TFB in diagnosing stomach cancer. In conclusion, this study illustrates the promising future of [18F]TFB for tumor diagnosis and NIS reporter imaging.


Asunto(s)
Neoplasias , Simportadores , Animales , Línea Celular , Línea Celular Tumoral , Ratones , Tomografía de Emisión de Positrones/métodos , Simportadores/genética , Simportadores/metabolismo , Distribución Tisular
6.
Int J Mol Sci ; 23(18)2022 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-36142890

RESUMEN

Salmonella typhimurium (S.T) induces damage to the central nervous system; however, the role of Asiatic acid (AA) in this is still unknown. Microglia play a role as macrophages to recognize the invaded pathogenic microbes in the brain. The aim of this study was to investigate the protective effect and mechanism of AA on the central nervous system through an in vitro model of S.T infection in microglia. We pre-treated microglia with AA before S.T infection and explored the anti-infection mechanism of AA by sequencing, quantitative reverse transcription PCR (RT-qPCR), and Western blotting. Long non-coding RNA (lncRNA) sequencing demonstrated that inflammation is a major factor in S.T infection of microglia. RT-qPCR data demonstrated that AA inhibited S.T-induced increases in the mRNA levels of the pro-inflammatory factors interleukin (IL)-1ß, IL-6, and IL-18. Western blotting demonstrated that AA inhibited S.T-induced activation of the nuclear factor (NF)-κB pathway and activation of the NLR family, pyrin domain-containing 3 (NLRP3) inflammasome. Expression of the lncRNA TVX1 in microglia was decreased by S.T infection and increased by pretreatment with AA. Inhibition of TVX1 expression reversed the anti-inflammatory effect of AA, and overexpression of TVX1 in microglia suppressed S.T-induced inflammation. In conclusion, AA attenuated S.T-induced microglial inflammation by upregulating the expression of the lncRNA TVX1.


Asunto(s)
Microglía , ARN Largo no Codificante , Antiinflamatorios/farmacología , Humanos , Inflamasomas/metabolismo , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Inflamación/genética , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Microglía/metabolismo , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Triterpenos Pentacíclicos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN Mensajero/metabolismo , Salmonella/metabolismo
7.
BMC Endocr Disord ; 21(1): 57, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33781239

RESUMEN

BACKGROUND: The role of miR-23b-3p in insulin resistance (IR) remained poorly understood. METHODS: After acacetin injection, obesity-induced IR model was constructed with or without miR-23b-3p upregulation and Neuraminidase 1 (NEU1) overexpression in mice. Body weight, serum metabolite and fat percent of the mice were measured. Tests on oral glucose and insulin tolerance were performed, and inflammatory cytokines C-reactive protein (CRP), Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein 1 (MCP1) levels were quantified with enzyme-linked immunosorbent assay (ELISA). The binding sites between miR-23b-3p and NEU1 were predicted by TargetScan, and verified using dual-luciferase reporter assay. Relative expressions were detected with quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Proportion of Treg and Th17 cells in total CD4+ T cells was detected with flow cytometry. RESULTS: MiR-23b-3p offset the effects of acacetin on body weight, fat percent, inflammatory cytokines levels and expressions of markers of regulatory T cells (Treg cells) and T helper 17 cells (Th17 cells), NEU1 and miR-23b-3p. NEU1 was a target of miR-23b-3p, and overexpressed NEU1 reversed the effects of upregulated miR-23b-3p on reducing Treg cells but increased body weight, fat percent and inflammatory cytokines levels, percentage of Th17 cells, and upregulated NEU1 expression. CONCLUSION: Upregulation of miR-23b-3p offset the effects of acacetin on obesity-induced IR through regulating Treg/Th17 cell balance via targeting NEU1.The present findings provide a possible prevention strategy for obesity-induced IR.


Asunto(s)
Resistencia a la Insulina , MicroARNs/metabolismo , Neuraminidasa/metabolismo , Obesidad/metabolismo , Células Th17 , Animales , Flavonas , Masculino , Ratones Endogámicos C57BL , Obesidad/inmunología
8.
Mol Divers ; 25(1): 525-533, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32410113

RESUMEN

Cerebral amyloid angiopathy (CAA) commonly found in the aged is pathologically characterized by ß-amyloid (Aß) deposition in the walls of arteries and capillaries of brain. In this study, four flexible multidentate benzyldiamine derivatives as potential probes for cerebrovascular Aß deposition were designed and synthesized. In in vitro inhibition assays, the ligands 18-21 displayed high affinities for Aß aggregates with Ki values of 1.45 ± 0.53 nM, 1.68 ± 0.35 nM, 1.16 ± 0.23 nM and 1.72 ± 0.19 nM, respectively. A significant improvement in the binding affinity over the monomer, compounds 9-12 or benzyldiamine derivatives, demonstrated the applicability of the multidentate approach. The underlying mechanism of these novel Aß agents was explored by molecular docking technique, which theoretically verified the high affinities of the multidentate benzyldiamine derivatives for Aß aggregates. Moreover, the molecular masses of the ligands 18-21 are more than 700 Dalton, which are believed to be hardly capable of penetrating blood brain barrier. In this regard, these ligands could be used to distinguish CAA from Alzheimer's disease which is another Aß-related disorder disease. To convert these ligands to positron emission tomography imaging agents, we attempted to radiosynthesize [18F]18. Though the radiolabeling was not very successful, the preliminary results suggested that these newly proposed multidentate benzyldiamine derivatives may be used as potential Aß imaging agents in cerebral amyloid angiopathy.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Bencilaminas/uso terapéutico , Angiopatía Amiloide Cerebral/tratamiento farmacológico , Bencilaminas/química , Bencilaminas/farmacología , Cromatografía Líquida de Alta Presión , Cromatografía de Fase Inversa , Simulación del Acoplamiento Molecular , Agregado de Proteínas
9.
Bioorg Med Chem Lett ; 30(11): 127160, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32247732

RESUMEN

The objective of the study was to prepare and evaluate a 18F-radiolabled tracer (Al18F-5), derivated from the antitumor agent 2-(4-aminophenyl)benzothiazole, as a PET probe for tumor imaging. Al18F-5 was successfully prepared with approx. 40% radiochemical yield in aqueous phase. In in vitro cell uptake experiments and competition assay, Al18F-5 displayed good tumor-binding ability and specificity in HeLa cells (24.7 ± 0.9% ID/106 cells, IC50 = 63.8 ± 13.6 nM) and MCF-7 cells (6.8 ± 0.3% ID/106 cells, IC50 = 331.1 ± 33.7 nM). The nonradioactive compound, Al19F-5, visibly marked HeLa cells and MCF-7 cells but did not stain HEB cells in florescent staining, which further indicated the tumor-binding ability of Al18F-5. In in vivo PET imaging, HeLa and MCF-7 tumors were clearly delineated by specific accumulation of Al18F-5 in model mice. In biodistribution study, Al18F-5 exhibited good tumor uptake (4.66 ± 0.13% ID/g and 3.69 ± 0.56% ID/g, respectively), moderate tumor-to-muscle ratio (3.38 and 2.48, respectively) at 1 h post injection, which were in a good consistency with the results of PET imaging. In conclusion, Al18F-5 might be developed as a candidate PET probe for tumor imaging, though additional optimizations are still needed to improve pharmacokinetics in vivo.


Asunto(s)
Benzotiazoles/química , Medios de Contraste/química , Radiofármacos/síntesis química , Animales , Benzotiazoles/metabolismo , Línea Celular Tumoral , Medios de Contraste/metabolismo , Radioisótopos de Flúor/química , Humanos , Ratones , Microscopía Fluorescente , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones , Radiofármacos/química , Radiofármacos/metabolismo , Distribución Tisular , Trasplante Heterólogo
10.
J Mater Sci Mater Med ; 31(3): 28, 2020 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-32125534

RESUMEN

Keratins derived from human hair have been suggested to be particularly effective in general surgical wound healing. However, the healing of a combined radiation-wound injury is a multifaceted regenerative process. Here, hydrogels fabricated with human hair keratins were used to test the wound healing effects on rats suffering from combined radiation-wound injuries. Briefly, the keratin extracts were verified by dodecyl sulfate polyacrylamide gel electrophoresis analysis and amino acid analysis, and the keratin hydrogels were then characterized by morphological observation, Fourier transform infrared spectroscopy analysis and rheology analyses. The results of the cell viability assay indicated that the keratin hydrogels could enhance cell growth after radiation exposure. Furthermore, keratin hydrogels could accelerate wound repair and improve the survival rate in vivo. The results demonstrate that keratin hydrogels possess a strong ability to accelerate the repair of a combined radiation-wound injury, which opens up new tissue regeneration applications for keratins.


Asunto(s)
Queratinas Específicas del Pelo/química , Queratinas Específicas del Pelo/uso terapéutico , Traumatismos por Radiación/terapia , Cicatrización de Heridas/efectos de los fármacos , Resinas Acrílicas/química , Animales , Materiales Biocompatibles/química , Proliferación Celular/efectos de los fármacos , Supervivencia Celular , Citocinas/metabolismo , Células HaCaT , Cabello/química , Humanos , Hidrogeles/química , Inflamación , Recuento de Leucocitos , Microscopía Electrónica de Rastreo , Ratas , Regeneración , Reología , Dodecil Sulfato de Sodio/química , Espectroscopía Infrarroja por Transformada de Fourier , Factores de Tiempo
11.
J Tradit Chin Med ; 35(3): 355-60, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26237843

RESUMEN

Powder formulae are an indispensable part of prescription in Traditional Chinese Medicine. Powder formulae are. characterized by good therapeutic efficacy and low dose used for their preparation. Analysis of the therapeutic application and material basis of pharmacological active substance in power formulae can enable the development of new powder formulae. This in turn can contribute to reduction of wastage of drug material, relief of shortage of herbal medicinal resources and sustainable development of Traditional Chinese Medicine.


Asunto(s)
Química Farmacéutica , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Animales , Quimioterapia , Humanos , Medicina Tradicional China
12.
Math Biosci Eng ; 21(2): 3304-3318, 2024 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-38454729

RESUMEN

In this paper, we investigated leader-following consensus control for nonlinear multi-agent systems (MASs) experiencing denial-of-service (DoS) attacks. We proposed a distributed control strategy incorporating an adaptive scheme and a state feedback control gain to eliminate the effects of system nonlinear dynamics and uncertainties. In addition, we introduced a dynamic event-triggered control (DETC) to minimize the utilization of communication resources. Finally, we provided simulation results to show the validity of the proposed approach.

13.
ACS Appl Bio Mater ; 7(3): 1976-1989, 2024 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-38447202

RESUMEN

The development of nanocarriers to prolong the residence time and enhance the permeability of chemotherapeutic drugs on bladder mucosa is important in the postsurgery treatment of superficial bladder cancers (BCs). Here, the mucoadhesive HA-SH/PF127 nanogels composed of a temperature-sensitive Pluronic F127 (PF127) core and thiolated hyaluronic acid (HA-SH) shell were prepared by the emulsification/solvent evaporation method. The nanogels were constructed through the thiol-maleimide click reaction in the HA-SH aqueous side of the oil-water interface and self-oxidized cross-linking thiols between HA-SH. The HA-SH/PF127 nanogels prepared at different thiol-to-maleimide group molar ratios, water-to-oil volume ratios, and cross-linking reaction times were characterized regarding hydrodynamic diameter (Dh) and zeta potential (ζ), and the optimal formulation was obtained. The excellent mucoadhesive properties of the HA-SH/PF127 nanogels were evaluated by using the mucin particle method. Doxorubicin (DOX) was encapsulated in the PF127 core of DOX@HA-SH/PF127 nanogels with a high loading efficiency (87.5%) and sustained release from the nanogels in artificial urine. Ex vivo studies on porcine bladder mucosa showed that the DOX@HA-SH/PF127 nanogels enhanced the penetration of the DOX into the bladder mucosa without disrupting the mucus structure or the bladder tissue. A significant dose-dependent cytotoxic effect of DOX@HA-SH/PF127 nanogels on both T24 and MB49 cells was observed. The present study demonstrates that the mucoadhesive HA-SH/PF127 nanogels are a promising intravesical drug delivery system for superficial BC therapy.


Asunto(s)
Ácido Hialurónico , Maleimidas , Poloxámero , Polietilenglicoles , Polietileneimina , Compuestos de Sulfhidrilo , Animales , Porcinos , Poloxámero/química , Nanogeles , Ácido Hialurónico/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Doxorrubicina/química , Agua
14.
Plants (Basel) ; 13(14)2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-39065435

RESUMEN

Flooding is a critical factor that limits the establishment of a symbiosis between rice and arbuscular mycorrhizal fungi (AMF) in wetland ecosystems. The distribution of carbon resources in roots and the acclimation strategies of rice to flooding stress in the presence of AMF are poorly understood. We conducted a root box experiment, employing nylon sheets or nylon meshes to create separate fungal chambers that either prevented or allowed the roots and any molecules to pass through. We found that the mycorrhizal colonization rate and the expression of genes OsD14L and OsCERK1, which are involved in fungal perception during symbiosis, both increased in mycorrhizal rice roots following intermittent flooding compared to continuous flooding. Furthermore, AMF inoculation affected root morphological traits, facilitating both shallower and deeper soil exploration. Increased submergence intensity led to carbohydrate deprivation in roots, while high mycorrhizal colonization increased soil oxygen consumption and decreased the neutral lipid concentration in roots. However, mycorrhizal inoculation increased the rice photosynthesis rate and facilitated acclimation to submergence by mediating the expression of the genes OsCIPK15 and OsSUB1A to enhance rice shoot elongation and the sugar concentration in roots as a result of reduced competition for carbon between rice and AMF under different flooding conditions.

15.
Aging (Albany NY) ; 15(22): 13176-13193, 2023 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-37988198

RESUMEN

The current study aims to understand the mechanisms behind regulated cell death (RCD) in diabetic nephropathy and identify related biomarkers through bioinformatics and experimental validation. Datasets of bulk and single-cell RNA sequencing were obtained from public databases and analyzed using gene set variation analysis (GSVA) with gene sets related to RCD, including autophagy, necroptosis, pyroptosis, apoptosis, and ferroptosis. RCD-related gene biomarkers were identified using weighted gene correlation network analysis (WGCNA). The results were verified through experiments with an independent cohort and in vitro experiments. The GSVA revealed higher necroptosis scores in diabetic nephropathy. Three necroptosis-related biomarkers, EGF, PAG1, and ZFP36, were identified and showed strong diagnostic ability for diabetic kidney disease. In vitro experiments showed high levels of necroptotic markers in HK-2 cells treated with high glucose. Bioinformatics and experimental validation have thus identified EGF and PAG1 as necroptosis-related biomarkers for diabetic nephropathy.


Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Muerte Celular Regulada , Humanos , Necroptosis , Nefropatías Diabéticas/genética , Factor de Crecimiento Epidérmico , Biomarcadores , Proteínas de la Membrana , Proteínas Adaptadoras Transductoras de Señales
16.
IEEE Trans Neural Netw Learn Syst ; 34(11): 8362-8376, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-35188895

RESUMEN

Collision detection is critical for autonomous vehicles or robots to serve human society safely. Detecting looming objects robustly and timely plays an important role in collision avoidance systems. The locust lobula giant movement detector (LGMD1) is specifically selective to looming objects which are on a direct collision course. However, the existing LGMD1 models cannot distinguish a looming object from a near and fast translatory moving object, because the latter can evoke a large amount of excitation that can lead to false LGMD1 spikes. This article presents a new visual neural system model (LGMD1) that applies a neural competition mechanism within a framework of separated ON and OFF pathways to shut off the translating response. The competition-based approach responds vigorously to monotonous ON/OFF responses resulting from a looming object. However, it does not respond to paired ON-OFF responses that result from a translating object, thereby enhancing collision selectivity. Moreover, a complementary denoising mechanism ensures reliable collision detection. To verify the effectiveness of the model, we have conducted systematic comparative experiments on synthetic and real datasets. The results show that our method exhibits more accurate discrimination between looming and translational events-the looming motion can be correctly detected. It also demonstrates that the proposed model is more robust than comparative models.


Asunto(s)
Saltamontes , Percepción de Movimiento , Animales , Humanos , Percepción de Movimiento/fisiología , Señales (Psicología) , Redes Neurales de la Computación , Saltamontes/fisiología , Movimiento , Vías Visuales/fisiología , Estimulación Luminosa/métodos
17.
Soft comput ; : 1-31, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37362274

RESUMEN

Crow search algorithm (CSA), as a new swarm intelligence algorithm that simulates the crows' behaviors of hiding and tracking food in nature, performs well in solving many optimization problems. However, while handling complex and high-dimensional global optimization problems, CSA is apt to fall into evolutionary stagnation and has slow convergence speed, low accuracy, and weak robustness. This is mainly because it only utilizes a single search stage, where position updating relies on random following among individuals or arbitrary flight of individuals. To address these deficiencies, a CSA with multi-stage search integration (MSCSA) is presented. Chaos and multiple opposition-based learning techniques are first introduced to improve original population quality and ergodicity. The free foraging stage based on normal random distribution and Lévy flight is designed to conduct local search for enhancing the solution accuracy. And the following stage using mixed guiding individuals is presented to perform global search for expanding the search space through tracing each other among individuals. Finally, the large-scale migration stage based on the best individual and mixed guiding individuals concentrates on increasing the population diversity and helping the population jump out of local optima by moving the population to a promising area. All of these strategies form multi-level and multi-granularity balances between global exploration and local exploitation throughout the evolution. The proposed MSCSA is compared with a range of other algorithms, including original CSA, three outstanding variants of CSA, two classical meta-heuristics, and six state-of-the-art meta-heuristics covering different categories. The experiments are conducted based on the complex and high-dimensional benchmark functions CEC 2017 and CEC 2010, respectively. The experimental and statistical results demonstrate that MSCSA is competitive for tackling large-scale complicated problems, and is significantly superior to the competitors.

18.
Front Bioeng Biotechnol ; 11: 1159507, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37274170

RESUMEN

Background: Chimeric antigen receptor (CAR) T cell treatment involves in vitro production of T cells from patient blood with synthetic receptors specific to a cancer antigen. They circumvent the major histocompatibility complex to recognize the tumor antigen, reducing hematologic malignancy remission rates by 80%. Considering the efficacy of CAR-T treatment, the present work aimed at generating functional clusters of differentiation (CD)8 + T cells from human induced pluripotent stem cells (hiPSC) and to generate hiPS-CAR-T cells with high antigen-specific cytotoxicity. Methods: The Alkaline phosphatase assay and MycoEasy rapid mycoplasma detection kit was implemented for detection of hiPSCs and mycoplasma, respectively. The CD34+ HSPCs were harvested in AggreWellTM 400 using a 37-micron reversible strainer. Likewise, the lymphoid progenitor and CD4+CD8+ DP T cells were also harvested. The Cell Counting Kit-8 (CCK-8) assay was used to mark cytotoxicity and ELISA was used to detect IFN-γ secretion. Further, flow cytometry and transwell chambers were used to assess cell cycle, and migration and invasion. Finally, the in vivo antitumor effects of the CAR-T cells were evaluated using experimental animals (mice). Results: Results revealed that a serum-free, feeder layer-free differentiation system significantly yielded hiPSC-based T cell immunotherapy with interleukin-2, interleukin-15, and activators at the differentiation stage to promote the maturation of these cells into human induced pluripotent stem (hiPS)-T cells. The infection of hiPSCs with the CD19 CAR lentivirus resulted in the production of the hiPSC-CAR-T cells. We validated the function of hiPS-CAR-T cells in vivo and in vitro experimentation which revealed no significant differences in cell morphology and function between hiPSC-derived hiPS-CAR-T cells and peripheral blood-derived CAR-T cells. Conclusion: This study developed a culture method that is efficient and clinically useful to make functional CD8+ T cells from hiPSC and to get hiPS-CAR-T cells with high antigen-specific cytotoxicity that are not very different from CAR T cells found in peripheral blood. As a result, our findings may open the way for the clinical use of hiPSC to create functional CD8+ T and hiPS-CAR-T cells cells for use in cell-based cancer therapy.

19.
J Affect Disord ; 328: 261-272, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36813041

RESUMEN

Maresin-1 is an antiphlogistic agonist synthesized by macrophages from docosahexaenoic acid (DHA). It has both anti-inflammatory and pro-inflammatory properties and has been found to enhance neuroprotection and cognitive function. However, there is limited knowledge of its effects on depression and the potential mechanism remains unclear. In this study, the effects of Maresin-1 on lipopolysaccharide (LPS)-induced depressive symptoms and neuroinflammation were investigated in mice and the possible cellular and molecular mechanisms were further clarified. Maresin-1 treatment (5 µg/kg, i.p.) led to improved tail suspension times, as well as distances moved in an open-field test but it did not improve reductions in sugar-water consumption in mice with depressive-like behaviors induced by LPS (1 mg/kg, i.p.); TSPO PETCT scanning showed that Maresin-1 reduced the standardized uptake value (SUV) of [18 F] DPA-714 in brain regions associated with depression (e.g., hippocampus and pre-frontal cortex), while immunofluorescence of hippocampal and indicated that Maresin-1 inhibited microglial activation reducing the expression of the pro-inflammatory cytokine IL-1ß and NLRP3. The RNA sequencing of mouse hippocampi showed that genes expressed differentially between Maresin-1-treated and LPS-treated tissue were associated with tight connections between cells and the stress-activated MAPK cascade negative regulatory pathways. Overall, this study demonstrates that peripheral application of Maresin-1 could partially relieve LPS-induced depressive-like behaviors and showed for the first time that this effect was related to its anti-inflammatory action on microglia, thus providing new clues for the pharmacological mechanism underlying the anti-depression properties of Maresin-1.


Asunto(s)
Lipopolisacáridos , Microglía , Ratones , Animales , Lipopolisacáridos/farmacología , Microglía/metabolismo , Ácidos Docosahexaenoicos , Antiinflamatorios/farmacología , Hipocampo/metabolismo
20.
Antioxidants (Basel) ; 12(4)2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37107285

RESUMEN

Phenolic acid is a well-known allelochemical, but also a pollutant in soil and water impeding crop production. Biochar is a multifunctional material widely used to mitigate the phenolic acids allelopathic effect. However, phenolic acid absorbed by biochar can still be released. In order to improve the removal efficiency of phenolic acids by biochar, the biochar-dual oxidant (BDO) composite particles were synthesized in this study, and the underlying mechanism of the BDO particles in ameliorating p-coumaric acid (p-CA) oxidative damage to tomato seed germination was revealed. Upon p-CA treatment, the BDO composite particles application increased the radical length, radical surface area, and germination index by 95.0%, 52.8%, and 114.6%, respectively. Compared to using biochar or oxidants alone, the BDO particles addition resulted in a higher removal rate of p-CA and produced more O2•-, HO•, SO4•- and 1O2 radicals via autocatalytic action, suggesting that BDO particles removed phenolic acid by both adsorption and free radical oxidation. The addition of BDO particles maintained the levels of the antioxidant enzyme activity close to the control, and reduced the malondialdehyde and H2O2 by 49.7% and 49.5%, compared to the p-CA treatment. Integrative metabolomic and transcriptomic analyses revealed that 14 key metabolites and 62 genes were involved in phenylalanine and linoleic acid metabolism, which increased dramatically under p-CA stress but down-regulated with the addition of BDO particles. This study proved that the use of BDO composite particles could alleviate the oxidative stress of phenolic acid on tomato seeds. The findings will provide unprecedented insights into the application and mechanism of such composite particles as continuous cropping soil conditioners.

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