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1.
Plant Cell ; 35(6): 2132-2156, 2023 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-36856677

RESUMEN

Phosphorus (P) is a macronutrient necessary for plant growth and development. Inorganic phosphate (Pi) deficiency modulates the signaling pathway of the phytohormone jasmonate in Arabidopsis thaliana, but the underlying molecular mechanism currently remains elusive. Here, we confirmed that jasmonate signaling was enhanced under low Pi conditions, and the CORONATINE INSENSITIVE1 (COI1)-mediated pathway is critical for this process. A mechanistic investigation revealed that several JASMONATE ZIM-DOMAIN (JAZ) repressors physically interacted with the Pi signaling-related core transcription factors PHOSPHATE STARVATION RESPONSE1 (PHR1), PHR1-LIKE2 (PHL2), and PHL3. Phenotypic analyses showed that PHR1 and its homologs positively regulated jasmonate-induced anthocyanin accumulation and root growth inhibition. PHR1 stimulated the expression of several jasmonate-responsive genes, whereas JAZ proteins interfered with its transcriptional function. Furthermore, PHR1 physically associated with the basic helix-loop-helix (bHLH) transcription factors MYC2, MYC3, and MYC4. Genetic analyses and biochemical assays indicated that PHR1 and MYC2 synergistically increased the transcription of downstream jasmonate-responsive genes and enhanced the responses to jasmonate. Collectively, our study reveals the crucial regulatory roles of PHR1 in modulating jasmonate responses and provides a mechanistic understanding of how PHR1 functions together with JAZ and MYC2 to maintain the appropriate level of jasmonate signaling under conditions of Pi deficiency.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fosfatos/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo
2.
Small ; : e2310608, 2024 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-38461532

RESUMEN

Depression is a significant global health concern that remains inadequately treated due to the limited effectiveness of conventional drug therapies. One potential therapeutic agent, hypericin (HYP), is identified as an effective natural antidepressant. However, its poor water solubility, low bioavailability, and limited ability to penetrate the brain parenchyma have hindered its clinical application. To address these shortcomings and enhance the therapeutic efficacy of HYP, it is loaded onto black phosphorus nanosheets (BP) modified with the neural cell-targeting peptide RVG29 to synthesize a nanoplatform named BP-RVG29@HYP (BRH). This platform served as a nanocarrier for HYP and integrated the advantages of BP with advanced delivery methods and precise targeting strategies. Under the influence of 808 nm near-infrared irradiation (NIR), BRH effectively traversed an in vitro BBB model. In vivo experiments validated these findings, demonstrating that treatment with BRH significantly alleviated depressive-like behaviors and oxidative stress in mice. Importantly, BRH exhibited an excellent safety profile, causing minimal adverse effects, which highlighted its potential as a promising therapeutic agent. In brief, this novel nanocarrier holds great promise in the development of antidepressant drugs and can create new avenues for the treatment of depression.

3.
Plant Physiol ; 193(2): 1675-1694, 2023 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-37379562

RESUMEN

CONSTANS (CO) is a critical regulator of flowering that combines photoperiodic and circadian signals in Arabidopsis (Arabidopsis thaliana). CO is expressed in multiple tissues, including seedling roots and young leaves. However, the roles and underlying mechanisms of CO in modulating physiological processes outside of flowering remain obscure. Here, we show that the expression of CO responds to salinity treatment. CO negatively mediated salinity tolerance under long-day (LD) conditions. Seedlings from co-mutants were more tolerant to salinity stress, whereas overexpression of CO resulted in plants with reduced tolerance to salinity stress. Further genetic analyses revealed the negative involvement of GIGANTEA (GI) in salinity tolerance requires a functional CO. Mechanistic analysis demonstrated that CO physically interacts with 4 critical basic leucine zipper (bZIP) transcription factors; ABSCISIC ACID-RESPONSIVE ELEMENT BINDING FACTOR1 (ABF1), ABF2, ABF3, and ABF4. Disrupting these ABFs made plants hypersensitive to salinity stress, demonstrating that ABFs enhance salinity tolerance. Moreover, ABF mutations largely rescued the salinity-tolerant phenotype of co-mutants. CO suppresses the expression of several salinity-responsive genes and influences the transcriptional regulation function of ABF3. Collectively, our results show that the LD-induced CO works antagonistically with ABFs to modulate salinity responses, thus revealing how CO negatively regulates plant adaptation to salinity stress.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Arabidopsis/metabolismo , Plantones/genética , Estrés Salino/genética , Regulación de la Expresión Génica de las Plantas , Estrés Fisiológico/genética , Plantas Modificadas Genéticamente/metabolismo , Proteínas de Unión al ADN/metabolismo
4.
J Nanobiotechnology ; 22(1): 122, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38504208

RESUMEN

Endocrine therapy is standard for hormone receptor-positive (HR+) breast cancer treatment. However, current strategies targeting estrogen signaling pay little attention to estradiol metabolism in the liver and is usually challenged by treatment failure. In a previous study, we demonstrated that the natural compound naringenin (NAR) inhibited HR+ breast cancer growth by activating estrogen sulfotransferase (EST) expression in the liver. Nevertheless, the poor water solubility, low bio-barrier permeability, and non-specific distribution limited its clinical application, particularly for oral administration. Here, a novel nano endocrine drug NAR-cell penetrating peptide-galactose nanoparticles (NCG) is reported. We demonstrated that NCG presented specific liver targeting and increased intestinal barrier permeability in both cell and zebrafish xenotransplantation models. Furthermore, NCG showed liver targeting and enterohepatic circulation in mouse breast cancer xenografts following oral administration. Notably, the cancer inhibition efficacy of NCG was superior to that of both NAR and the positive control tamoxifen, and was accompanied by increased hepatic EST expression and reduced estradiol levels in the liver, blood, and tumor tissue. Moreover, few side effects were observed after NCG treatment. Our findings reveal NCG as a promising candidate for endocrine therapy and highlight hepatic EST targeting as a novel therapeutic strategy for HR+ breast cancer.


Asunto(s)
Neoplasias de la Mama , Flavanonas , Nanopartículas , Humanos , Ratones , Animales , Femenino , Neoplasias de la Mama/patología , Pez Cebra/metabolismo , Receptores de Estrógenos/metabolismo , Estrógenos/metabolismo , Estrógenos/uso terapéutico , Tamoxifeno/farmacología , Estradiol/farmacología , Hígado/metabolismo
5.
J Appl Math Comput ; 69(3): 2473-2502, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36846484

RESUMEN

When a rumor appears on social networks, the media of relevant departments need reaction time to make an authoritative announcement. Considering the effects of the media report and time delay on a rumor spreading, and the different attitudes of individuals towards media reports. We proposed a susceptible-expose-infective-media-remover (SEIMR) rumor propagation model with media reports and time delay. Firstly, the basic reproduction number of the model is obtained. Secondly, the positivity, boundedness and existence of the solutions of the model are analyzed. Then, the local asymptotic stability of the rumor free equilibrium and the boundary equilibriums is proved, and the global asymptotic stability of the equilibriums is proved by constructing Lyapunov function when the time delay is zero. Besides, the prevention and control effects of the media report on rumor spreading and the effect of time delay are analyzed. The shorter time delay in media report and the greater the impact of the media report, the more effective the suppression of rumors will be. Finally, the accuracy of the theoretical results as well as the effects of different parameters of the model have been verified through numerical simulations, and the effectiveness of the SEIMR model has been verified via comparative experiments.

6.
Bull Math Biol ; 84(4): 47, 2022 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-35218432

RESUMEN

In order to understand how Wuhan curbed the COVID-19 outbreak in 2020, we build a network transmission model of 123 dimensions incorporating the impact of quarantine and medical resources as well as household transmission. Using our new model, the final infection size of Wuhan is predicted to be 50,662 (95%CI: 46,234, 55,493), and the epidemic would last until April 25 (95%CI: April 23, April 29), which are consistent with the actual situation. It is shown that quarantining close contacts greatly reduces the final size and shorten the epidemic duration. The opening of Fangcang shelter hospitals reduces the final size by about 17,000. Had the number of hospital beds been sufficient when the lockdown started, the number of deaths would have been reduced by at least 54.26%. We also investigate the distribution of infectious individuals in unquarantined households of different sizes. The high-risk households are those with size from two to four before the peak time, while the households with only one member have the highest risk after the peak time. Our findings provide a reference for the prevention, mitigation and control of COVID-19 in other cities of the world.


Asunto(s)
COVID-19 , Modelos Epidemiológicos , Cuarentena , COVID-19/epidemiología , COVID-19/prevención & control , China/epidemiología , Ciudades , Control de Enfermedades Transmisibles , Humanos , SARS-CoV-2
7.
Mol Psychiatry ; 25(12): 3186-3197, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32820237

RESUMEN

Depression and anxiety are common comorbidities in breast cancer patients. Whether depression and anxiety are associated with breast cancer progression or mortality is unclear. Herein, based on a systematic literature search, 17 eligible studies involving 282,203 breast cancer patients were included. The results showed that depression was associated with cancer recurrence [1.24 (1.07, 1.43)], all-cause mortality [1.30 (1.23, 1.36)], and cancer-specific mortality [1.29 (1.11, 1.49)]. However, anxiety was associated with recurrence [1.17 (1.02, 1.34)] and all-cause mortality [1.13 (1.07, 1.19)] but not with cancer-specific mortality [1.05 (0.82, 1.35)]. Comorbidity of depression and anxiety is associated with all-cause mortality [1.34 (1.24, 1.45)] and cancer-specific mortality [1.45 (1.11, 1.90)]. Subgroup analyses demonstrated that clinically diagnosed depression and anxiety, being female and of younger age (<60 years), and shorter follow-up duration (≤5 years) were related to a poorer prognosis. Our study highlights the critical role of depression/anxiety as an independent factor in predicting breast cancer recurrence and survival. Further research should focus on a favorable strategy that works best to improve outcomes among breast cancer patients with mental disorders.


Asunto(s)
Neoplasias de la Mama , Ansiedad , Depresión , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Pronóstico
8.
Cell Commun Signal ; 19(1): 89, 2021 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-34461944

RESUMEN

BACKGROUND: Metastasis represents the leading cause of death in patients with breast cancer. Traditional Chinese medicine is particularly appreciated for metastatic diseases in Asian countries due to its benefits for survival period prolongation and immune balance modulation. However, the underlying molecular mechanisms remain largely unknown. This study aimed to explore the antimetastatic effect and immunomodulatory function of a clinical formula Aiduqing (ADQ). METHODS: Naive CD4+ T cells, regulatory T cells (Tregs), and CD8+ T cells were sorted by flow cytometry. Then, breast cancer cells and these immune cells were co-cultured in vitro or co-injected into mice in vivo to simulate their coexistence. Flow cytometry, ELISA, qPCR, double luciferase reporter gene assay, and chromatin immunoprecipitation assay were conducted to investigate the immunomodulatory and antimetastatic mechanisms of ADQ. RESULTS: ADQ treatment by oral gavage significantly suppressed 4T1-Luc xenograft growth and lung metastasis in the orthotopic breast cancer mouse model, without noticeable hepatotoxicity, nephrotoxicity, or hematotoxicity. Meanwhile, ADQ remodeled the immunosuppressive tumor microenvironment (TME) by increasing the infiltration of tumor-infiltrating lymphocytes (TILs) and cytotoxic CD8+ T cells, and decreasing the infiltration of Tregs, naive CD4+ T cells, and tumor-associated macrophages (TAMs). Molecular mechanism studies revealed that ADQ remarkably inhibited CXCL1 expression and secretion from TAMs and thus suppressed the chemotaxis and differentiation of naive CD4+ T cells into Tregs, leading to the enhanced cytotoxic effects of CD8+ T cells. Mechanistically, TAM-derived CXCL1 promoted the differentiation of naive CD4+ T cells into Tregs by transcriptionally activating the NF-κB/FOXP3 signaling. Lastly, mouse 4T1-Luc xenograft experiments validated that ADQ formula inhibited breast cancer immune escape and lung metastasis by suppressing the TAM/CXCL1/Treg pathway. CONCLUSIONS: This study not only provides preclinical evidence supporting the application of ADQ in inhibiting breast cancer metastasis but also sheds novel insights into TAM/CXCL1/NF-κB/FOXP3 signaling as a promising therapeutic target for Treg modulation and breast cancer immunotherapy. Video Abstract.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Quimiocina CXCL1/genética , Medicina Tradicional China , Animales , Antineoplásicos/química , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD8-positivos/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Ratones , Metástasis de la Neoplasia , Linfocitos T Reguladores/efectos de los fármacos , Microambiente Tumoral/efectos de los fármacos , Macrófagos Asociados a Tumores/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
9.
J Math Biol ; 84(1-2): 1, 2021 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-34904196

RESUMEN

In this paper, we give a rather complete analysis for a susceptible-infective sexually transmitted disease (STD) model, where the males are divided into two different groups based on their different sexual orientation. The threshold [Formula: see text] of STD model is obtained. If [Formula: see text], the disease-free equilibrium is globally asymptotically stable. Further, we investigate the existence and stability of the boundary equilibria that characterize the males of the different sexual orientation. We also investigate the existence and stability of the positive equilibrium, which characterizes the possibility of coexistence of male heterosexual and male homosexual. We obtain sufficient and necessary conditions for the existence and global stability of these equilibria. We see that the proportion of heterosexuality in MSM affects the stability of the system. The theoretical results are verified by numerical simulation.


Asunto(s)
Minorías Sexuales y de Género , Enfermedades de Transmisión Sexual , Femenino , Heterosexualidad , Homosexualidad Masculina , Humanos , Masculino , Conducta Sexual , Enfermedades de Transmisión Sexual/epidemiología
10.
Theor Appl Genet ; 133(5): 1777-1790, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31754760

RESUMEN

KEY MESSAGE: Molecular breeding of Cucumis sativus L. is based on traditional breeding techniques and modern biological breeding in China. There are opportunities for further breeding improvement by molecular design breeding and the automation of phenotyping technology using untapped sources of genetic diversity. Cucumber (Cucumis sativus L.) is an important vegetable cultivated worldwide. It bears fruits of light fragrance, and crisp texture with high nutrition. China is the largest producer and consumer of cucumber, accounting for 70% of the world's total production. With increasing consumption demand, the production of Cucurbitaceae crops has been increasing yearly. Thus, new cultivars that can produce high-quality cucumber with high yield and easy cultivation are in need. Conventional genetic breeding has played an essential role in cucumber cultivar innovation over the past decades. However, its progress is slow due to the long breeding period, and difficulty in selecting stable genetic characters or genotypes, prompting researchers to apply molecular biotechnologies in cucumber breeding. Here, we first summarize the achievements of conventional cucumber breeding such as crossing and mutagenesis, and then focus on the current status of molecular breeding of cucumber in China, including the progress and achievements on cucumber genomics, molecular mechanism underlying important agronomic traits, and also on the creation of high-quality multi-resistant germplasm resources, new variety breeding and ecological breeding. Future development trends and prospects of cucumber molecular breeding in China are also discussed.


Asunto(s)
Cucumis sativus/crecimiento & desarrollo , Cucumis sativus/genética , Genoma de Planta , Genómica/métodos , Fitomejoramiento/métodos , Sitios de Carácter Cuantitativo , China , Mapeo Cromosómico , Fenotipo
11.
J Theor Biol ; 449: 1-13, 2018 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-29649430

RESUMEN

In this paper, the correlation coefficients between nodes in states are used as dynamic variables, and we construct SIR epidemic dynamic models with correlation coefficients by using the pair approximation method in static networks and dynamic networks, respectively. Considering the clustering coefficient of the network, we analytically investigate the existence and the local asymptotic stability of each equilibrium of these models and derive threshold values for the prevalence of diseases. Additionally, we obtain two equivalent epidemic thresholds in dynamic networks, which are compared with the results of the mean field equations.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Simulación por Computador , Modelos Biológicos , Humanos
12.
Bull Math Biol ; 80(4): 840-863, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29492829

RESUMEN

A two-patch model for the spread of West Nile virus between two discrete geographic regions is established to incorporate a mobility process which describes how contact transmission occurs between individuals from and between two regions. In the mobility process, we assume that the host birds can migrate between regions, but not the mosquitoes. The basic reproduction number [Formula: see text] is computed by the next generation matrix method. We prove that if [Formula: see text], then the disease-free equilibrium is globally asymptotically stable. If [Formula: see text], the endemic equilibrium is globally asymptotically stable for any nonnegative nontrivial initial data. Using the perturbation theory, we obtain the concrete expression of the endemic equilibrium of the model with a mild restriction of the birds movement rate between patches. Finally, numerical simulations demonstrate that the disease becomes endemic in both patches when birds move back and forth between the two regions. Some numerical simulations for [Formula: see text] in terms of the birds movement rate are performed which show that the impacts could be very complicated.


Asunto(s)
Modelos Biológicos , Fiebre del Nilo Occidental/transmisión , Virus del Nilo Occidental , Migración Animal , Animales , Número Básico de Reproducción , Aves/virología , Simulación por Computador , Culicidae/virología , Vectores de Enfermedades , Interacciones Huésped-Patógeno , Humanos , Conceptos Matemáticos , Mosquitos Vectores/virología , Fiebre del Nilo Occidental/epidemiología
13.
Mol Divers ; 22(4): 791-802, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29808346

RESUMEN

A series of quinazoline derivatives containing a 1,3,4-oxadiazole moiety were synthesized and evaluated for their antibacterial activities against Xanthomonas axonopodis pv. citri (Xac) and Ralstonia solanacearum (Rs). Antibacterial bioassays indicated that most of target compounds exhibited significant antibacterial activities against Xac and Rs in vitro. Strikingly, compounds 6d-6i, 6m-6r and 6u-6x showed antibacterial activity against Xac, with [Formula: see text] values ranging from 14.42 to 38.91 [Formula: see text]g/mL, which are better than that of bismerthiazol (39.86 [Formula: see text]g/mL). Based on the antibacterial activity against Xac, comparative molecular filed analysis and comparative molecular similarity index analysis models were generated to investigate the structure-activity relationship of title compounds against Xac. The analytical results indicated that the above models exhibited good predictive accuracy and could be used as practical tools for guiding the design and synthesis of more potent quinazoline derivatives containing a 1,3,4-oxadiazole moiety.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Oxadiazoles/química , Relación Estructura-Actividad Cuantitativa , Quinazolinas/química , Quinazolinas/farmacología , Xanthomonas axonopodis/efectos de los fármacos , Antibacterianos/síntesis química , Técnicas de Química Sintética , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Quinazolinas/síntesis química
14.
J Enzyme Inhib Med Chem ; 33(1): 130-138, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29199491

RESUMEN

To develop novel anti-inflammatory agents, a series of new pentadienone oxime ester compounds were designed and synthesized. The structures were determined by IR, 1H NMR, 13 C NMR, and HRMS. All compounds have been screened for their anti-inflammatory activity by evaluating their inhibition against LPS-induced nitric oxide (NO) release in RAW 264.7 cell. Among them, compound 5j was found to be one of the most potent compounds in inhibiting NO and IL-6 (IC50 values were 6.66 µM and 5.07 µM, respectively). Preliminary mechanism studies show that title compound 5j could significantly suppress expressions of nitric oxide synthase, COX-2, and NO, IL-6 through Toll-like receptor 4/mitogen-activated protein kinases/NF-κB signalling pathway. These data support further studies to assess rational design of more efficient pentadienone oxime ester derivatives with anti-inflammatory activity in the future.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Ésteres/farmacología , Cetonas/farmacología , Lipopolisacáridos/antagonistas & inhibidores , Óxido Nítrico/antagonistas & inhibidores , Oximas/farmacología , Animales , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/química , Relación Dosis-Respuesta a Droga , Ésteres/química , Cetonas/química , Lipopolisacáridos/farmacología , Ratones , Estructura Molecular , Óxido Nítrico/biosíntesis , Oximas/química , Células RAW 264.7 , Relación Estructura-Actividad
16.
Sheng Li Ke Xue Jin Zhan ; 46(1): 17-22, 2015 Feb.
Artículo en Zh | MEDLINE | ID: mdl-26103721

RESUMEN

Cancer stem cells(CSCs) have been reported in many human tumors and are associated with tumor initiation and progression. CSCs share many biological properties with normal somatic stem cells, such as self-renewal, the propagation of differentiated progeny. However, they also have differences in their chemoresistance and tumorigenic and metastatic activity. CSCs have potential clinical importance, but the regulation at the molecular level is not well-understood. MicroRNAs(miRNAs) are a class of endogenous non-coding RNAs, and play important role in the regulation of several cellular processes. Varieties of evidence show that, miRNAs can regulates the CSCs at a molecular level and are associated with tumor initiation and progression. Better understanding of the regulation of CSCs gene expression by miRNAs could be used to identify the biomarkers and therapeutic targets. In the present review, we summarize the major development on the regulation of CSCs by miRNAs.


Asunto(s)
Carcinogénesis/metabolismo , MicroARNs/metabolismo , Neoplasias/patología , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Diferenciación Celular , Humanos
17.
Math Biosci Eng ; 21(4): 5430-5445, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38872542

RESUMEN

A new network-based SIR epidemic model with saturated incidence rate and nonlinear recovery rate is proposed. We adopt an edge-compartmental approach to rewrite the system as a degree-edge-mixed model. The explicit formula of the basic reproduction number $ \mathit{\boldsymbol{R_{0}}} $ is obtained by renewal equation and Laplace transformation. We find that $ \mathit{\boldsymbol{R_{0}}} < 1 $ is not enough to ensure global asymptotic stability of the disease-free equilibrium, and when $ \mathit{\boldsymbol{R_{0}}} > 1 $, the system can exist multiple endemic equilibria. When the number of hospital beds is small enough, the system will undergo backward bifurcation at $ \mathit{\boldsymbol{R_{0}}} = 1 $. Moreover, it is proved that the stability of feasible endemic equilibrium is determined by signs of tangent slopes of the epidemic curve. Finally, the theoretical results are verified by numerical simulations. This study suggests that maintaining sufficient hospital beds is crucial for the control of infectious diseases.

18.
Infect Dis Model ; 9(2): 437-457, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38385020

RESUMEN

In this paper, we analyze the global asymptotic behaviors of a mathematical susceptible-infected(SI) age-infection-structured human immunodeficiency virus(HIV) model with heterogeneous transmission. Mathematical analysis shows that the local and global dynamics are completely determined by the basic reproductive number R0. If R0<1, disease-free equilibrium is globally asymptotically stable. If R0>1, it shows that disease-free equilibrium is unstable and the unique endemic equilibrium is globally asymptotically stable. The proofs of global stability utilize Lyapunov functions. Besides, the numerical simulations are illustrated to support these theoretical results and sensitivity analysis of each parameter for R0 is performed by the method of partial rank correlation coefficient(PRCC).

19.
Infect Dis Model ; 9(1): 56-69, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38130878

RESUMEN

In this paper, with the method of epidemic dynamics, we assess the spread and prevalence of COVID-19 after the policy adjustment of prevention and control measure in December 2022 in Taiyuan City in China, and estimate the excess population deaths caused by COVID-19. Based on the transmission mechanism of COVID-19 among individuals, a dynamic model with heterogeneous contacts is established to describe the change of control measures and the population's social behavior in Taiyuan city. The model is verified and simulated by basing on reported case data from November 8th to December 5th, 2022 in Taiyuan city and the statistical data of the questionnaire survey from December 1st to 23rd, 2022 in Neijiang city. Combining with reported numbers of permanent residents and deaths from 2017 to 2021 in Taiyuan city, we apply the dynamic model to estimate theoretical population of 2022 under the assumption that there is no effect of COVID-19. In addition, we carry out sensitivity analysis to determine the propagation character of the Omicron strain and the effect of the control measures. As a result of the study, it is concluded that after adjusting the epidemic policy on December 6th, 2022, three peaks of infection in Taiyuan are estimated to be from December 22nd to 31st, 2022, from May 10th to June 1st, 2023, and from September 5th to October 13th, 2023, and the corresponding daily peaks of new cases can reach 400 000, 44 000 and 22 000, respectively. By the end of 2022, excess deaths can range from 887 to 4887, and excess mortality rate can range from 3.06% to 14.82%. The threshold of the infectivity of the COVID-19 variant is estimated 0.0353, that is if the strain infectivity is above it, the epidemic cannot be control with the previous normalization measures.

20.
J Extracell Vesicles ; 13(7): e12493, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39051750

RESUMEN

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and chemotherapy is the cornerstone treatment for TNBC. Regrettably, emerging findings suggest that chemotherapy facilitates pro-metastatic changes in the tumour microenvironment. Extracellular vesicles (EVs) have been highly implicated in cancer drug resistance and metastasis. However, the effects of the EVs released from dying cancer cells on TNBC prognosis and corresponding therapeutic strategies have been poorly investigated. This study demonstrated that paclitaxel chemotherapy elicited CXCL1-enriched EVs from apoptotic TNBC cells (EV-Apo). EV-Apo promoted the chemoresistance and invasion of co-cultured TNBC cells by polarizing M2 macrophages through activating PD-L1 signalling. However, baohuoside I (BHS) remarkably sensitized the co-cultured TNBC cells to paclitaxel chemotherapy via modulating EV-Apo signalling. Mechanistically, BHS remarkably decreased C-X-C motif chemokine ligand 1 (CXCL1) cargo within EV-Apo and therefore attenuated macrophage M2 polarization by suppressing PD-L1 activation. Additionally, BHS decreased EV-Apo release by diminishing the biogenesis of intraluminal vesicles (ILVs) within multivesicular bodies (MVBs) of TNBC cells. Furthermore, BHS bound to the LEU104 residue of flotillin 2 (FLOT2) and interrupted its interaction with RAS oncogene family member 31 (RAB31), leading to the blockage of RAB31-FLOT2 complex-driven ILV biogenesis. Importantly, BHS remarkably chemosensitised paclitaxel to inhibit TNBC metastasis in vivo by suppressing EV-ApoCXCL1-induced PD-L1 activation and M2 polarization of tumour-associated macrophages (TAMs). This pioneering study sheds light on EV-ApoCXCL1 as a novel therapeutic target to chemosensitise TNBC, and presents BHS as a promising chemotherapy adjuvant to improve TNBC chemosensitivity and prognosis by disturbing EV-ApoCXCL1 biogenesis.


Asunto(s)
Apoptosis , Quimiocina CXCL1 , Vesículas Extracelulares , Paclitaxel , Neoplasias de la Mama Triple Negativas , Humanos , Paclitaxel/farmacología , Paclitaxel/uso terapéutico , Femenino , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/efectos de los fármacos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Apoptosis/efectos de los fármacos , Quimiocina CXCL1/metabolismo , Línea Celular Tumoral , Animales , Ratones , Transducción de Señal/efectos de los fármacos , Microambiente Tumoral/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos
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