Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
RSC Adv ; 14(32): 23459-23465, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39055265

RESUMEN

Catalytic propane dehydrogenation (PDH) has mainly been studied using metal- and metal oxide-based catalysts. Studies on dehydrogenation catalysis by metal hydrides, however, have rarely been reported. In this study, PDH reactions using group IIIB and IVB metal hydride catalysts were investigated under relatively low-temperature conditions of 450 °C. Lanthanum hydride exhibited the lowest activation energy for dehydrogenation and the highest propylene yield. Based on kinetics studies, a comparison between the reported calculation results and isotope experiments, the hydrogen vacancies of metal hydrides were involved in low-temperature PDH reactions.

2.
Nat Commun ; 15(1): 6131, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39033133

RESUMEN

One question in lymphocyte homing is how integrins are rapidly activated to enable immediate arrest of fast rolling lymphocytes upon encountering chemokines at target vascular beds given the slow chemokine-induced integrin inside-out activation. Herein we demonstrate that chemokine CCL25-triggered Ca2+ influx induces T cell membrane-proximal external Ca2+ concentration ([Ca2+]ex) drop in 6 s from physiological concentration 1.2 mM to 0.3 mM, a critical extracellular Ca2+ threshold for inducing αLß2 activation, triggering rapid αLß2 activation and T cell arrest before occurrence of αLß2 inside-out activation. Talin knockdown inhibits the slow inside-out activation of αLß2 but not [Ca2+]ex drop-triggered αLß2 quick activation. Blocking Ca2+ influx significantly suppresses T cell rolling-to-arrest transition and homing to skin lesions in a mouse psoriasis model, thus alleviating skin inflammation. [Ca2+]ex decrease-triggered rapid integrin activation bridges the gap between initial chemokine stimulation and slow integrin inside-out activation, ensuring immediate lymphocyte arrest and subsequent diapedesis on the right location.


Asunto(s)
Calcio , Linfocitos T , Talina , Animales , Calcio/metabolismo , Ratones , Linfocitos T/inmunología , Linfocitos T/metabolismo , Talina/metabolismo , Humanos , Psoriasis/metabolismo , Psoriasis/inmunología , Ratones Endogámicos C57BL , Membrana Celular/metabolismo , Integrinas/metabolismo , Señalización del Calcio , Piel/metabolismo
3.
Medicine (Baltimore) ; 103(21): e38354, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38787971

RESUMEN

BACKGROUND: The aim of this study is to examine the impact of the Orlistat on glucose levels and glucose tolerance in individuals with prediabetes, as well as assess its efficacy and safety in preventing the progression to diabetes. METHODS: For achieving the appropriate randomized controlled trials, we enrolled the public datas from the following electronic databases: The Cochrane library, Embase, China National Knowledge Infrastructure, VIP, Wan-Fang, and China Biology Medicine disc. The article focused on the orlistat intervention of glucose tolerance and glycemic status in prediabetic patients. We restricted the publication time from the creation to May 2023. RESULTS: Six subjects were included in the study, with a total of 1076 participants (532 in the control group vs 544 in the experimental group). The results indicated that the orlistat can reduce the fasting blood glucose [relative risk (RR) = -2.18, 95% confidence intervals (CI) (-2.471, -1.886)], as well as the 2 hour postprandial blood glucose [RR = -1.497, 95% CI (-1.811, -1.183)]. Furthermore, it can prevent the impaired glucose tolerance patients to type 2 diabetes mellitus [RR = 0.605, 95% CI (0.462, 0.791)], and reversal the impaired glucose tolerance [RR = 2.092, 95% CI (1.249, 3.503)]. CONCLUSIONS: In prediabetic people, the orlistat can control weight, reduce the fasting blood glucose and the 2 hour postprandial blood glucose, and then delay the progression of diabetes. However, due to the quantitative restrictions, additional high-quality study needs to be conducted to improve the reliability of the results.


Asunto(s)
Fármacos Antiobesidad , Glucemia , Diabetes Mellitus Tipo 2 , Progresión de la Enfermedad , Orlistat , Estado Prediabético , Humanos , Orlistat/uso terapéutico , Orlistat/farmacología , Estado Prediabético/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucemia/efectos de los fármacos , Fármacos Antiobesidad/uso terapéutico , Fármacos Antiobesidad/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Lactonas/uso terapéutico
4.
Cell Rep ; 42(6): 112667, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37330909

RESUMEN

Dynamic regulation of integrin activation and inactivation is critical for precisely controlled cell adhesion and migration in physiological and pathological processes. The molecular basis for integrin activation has been intensively studied; however, the understanding of integrin inactivation is still limited. Here, we identify LRP12 as an endogenous transmembrane inhibitor for α4 integrin activation. The LRP12 cytoplasmic domain directly binds to the integrin α4 cytoplasmic tail and inhibits talin binding to the ß subunit, thus keeping integrin inactive. In migrating cells, LRP12-α4 interaction induces nascent adhesion (NA) turnover at the leading-edge protrusion. Knockdown of LRP12 leads to increased NAs and enhanced cell migration. Consistently, LRP12-deficient T cells show an enhanced homing capability in mice and lead to aggravated chronic colitis in a T cell-transfer colitis model. Altogether, LRP12 is a transmembrane inactivator for integrins that inhibits α4 integrin activation and controls cell migration by maintaining balanced NA dynamics.


Asunto(s)
Integrina alfa4 , Integrinas , Proteínas Relacionadas con Receptor de LDL , Animales , Cricetinae , Ratones , Adhesión Celular/fisiología , Movimiento Celular/fisiología , Células CHO , Integrina alfa4/metabolismo , Integrinas/metabolismo , Unión Proteica , Humanos , Proteínas Relacionadas con Receptor de LDL/metabolismo
7.
Rapid Commun Mass Spectrom ; 37(1): e9419, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36260057

RESUMEN

Metabolism is undoubtedly significantly correlated with the efficacy and safety of traditional Chinese medicine. In clinic, Qi-Yu-San-Long decoction (QYSLD) has achieved good results in the treatment of non-small-cell lung cancer (NSCLC). Nevertheless, a detailed understanding of the compounds (prototypes and metabolites) of QYSLD and its dynamic metabolic profile in plasma has not been revealed. METHODS: In this study, a rapid and sensitive method based on ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF/MSE ), combined with a four-step analysis strategy, was established to investigate QYSLD metabolic profile in rat plasma. RESULTS: In all, 101 xenobiotics (41 prototypes and 60 QYSLD-related metabolites) were identified in rat plasma. The research uncovered metabolic profiles of alkaloids, saponins, flavonoids, iridoids, anthraquinones, and phenylpropanoids of QYSLD in rat plasma. The dynamic changes in these xenobiotics were also observed at different time intervals. At 0.5 h after oral administration, only 15 prototypes and 11 metabolites were detected. Within 24 h, 4 prototypes and 20 metabolites can still be detected. Four prototypes and 10 metabolites had the phenomenon of emergence-disappearance-reappearance in vivo. CONCLUSION: In rat plasma, 101 xenobiotics of QYSLD were identified and their dynamic metabolic profiles were systematically delineated, which laid a material basis for further research of the pharmacodynamic substances of QYSLD inhibiting NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Medicamentos Herbarios Chinos , Neoplasias Pulmonares , Ratas , Animales , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Ratas Sprague-Dawley , Cromatografía Liquida , Xenobióticos , Administración Oral
8.
Front Pharmacol ; 13: 989139, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36339563

RESUMEN

Qi-Yu-San-Long decoction (QYSLD), a traditional Chinese medicine (TCM) prescription, consisting of ten types of herbal medicine which has significant clinical efficacy in the treatment of non-small cell lung cancer (NSCLC). However, the bioactive ingredients of QYSLD remain unclear, due to their "multi-ingredients" and "multi-targets" features. This study aimed to construct a spectrum-effect correlation analysis model and screen the potential active components of QYSLD. A fingerprint method based on ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was developed and validated to obtain seventy common peaks of ten batches of QYSLD. The results of methodological evaluation, including precision, repeatability and stability, were less than 8.19%. In terms of linearity, eleven common components did not reach the linear standard (R2 < 0.99), they were removed before spectrum-effect relationship analysis. After treated with ten batches of QYSLD, the results of DPPH and FRAP assays ranged from 1.59 to 5.50 mg mL-1 and 143.83-873.83 µmol L-1, respectively. Meanwhile, the cell viabilities of A549 cells treated with QYSLD samples ranged from 21.73% to 85.71%. The relative healing rates ranged from 21.50% to 44.46%. The number of migrated and invaded cells ranged from 12.00 to 68.67 and 7.67 to 27.00, respectively. Then, the potential active components of QYSLD were screened through spectrum-effect relationship constructed by grey correlation analysis (GRA), partial least squares regression (PLSR) and backpropagation neural network (BP-ANN). The results were as follow: 1) eight ingredients of QYSLD were relevant to DPPH free radical scavenging ability; 2) nine ingredients were relevant to FRAP; 3) six ingredients were relevant to inhibit the proliferation ability of A549 cells; 4) twenty-two ingredients were relevant to inhibit the horizontal migration ability; 5) five ingredients were relevant to inhibit the vertical migration ability; 6) twelve ingredients were relevant to inhibit the invasion ability. Confirmatory experiments showed that compared with the unscreened ingredients, the potential active ingredients screened by the spectrum-effect relationship had better antioxidant and anti-NSCLC effects. In general, this study found the potential active ingredients in QYSLD. Meanwhile, the established method provided a valuable reference model for the potential active ingredients of TCM.

9.
J Pharm Anal ; 12(5): 755-765, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36320602

RESUMEN

Qi-Yu-San-Long decoction (QYSLD) is a traditional Chinese medicine that has been clinically used in the treatment of non-small-cell lung cancer (NSCLC) for more than 20 years. However, to date, metabolic-related studies on QYSLD have not been performed. In this study, a post-targeted screening strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight full information tandem mass spectrometry (UPLC-QTOF-MSE) was developed to identify QYSLD-related xenobiotics in rat urine. The chemical compound database of QYSLD constituents was established from previous research, and metabolites related to these compounds were predicted in combination with their possible metabolic pathways. The metabolites were identified by extracted ion chromatograms using predicted m/z values as well as retention time, excimer ions, and fragmentation behavior. Overall, 85 QYSLD-related xenobiotics (20 prototype compounds and 65 metabolites) were characterized from rat urine. The main metabolic reactions and elimination features of QYSLD included oxidation, reduction, decarboxylation, hydrolysis, demethylation, glucuronidation, sulfation, methylation, deglycosylation, acetylation, and associated combination reactions. Of the identified molecules, 14 prototype compounds and 58 metabolites were slowly eliminated, thus accumulating in vivo over an extended period, while five prototypes and two metabolites were present in vivo for a short duration. Furthermore, one prototype and five metabolites underwent the process of "appearing-disappearing-reappearing" in vivo. Overall, the metabolic profile and characteristics of QYSLD in rat urine were determined, which is useful in elucidating the active components of the decoction in vivo, thus providing the basis for studying its mechanism of action.

10.
Acta Pharm Sin B ; 12(9): 3456-3474, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35818435

RESUMEN

Mucosal vaccines can effectively induce an immune response at the mucosal site and form the first line of defense against microbial invasion. The induced mucosal immunity includes the proliferation of effector T cells and the production of IgG and IgA antibodies, thereby effectively blocking microbial infection and transmission. However, after a long period of development, the transformation of mucosal vaccines into clinical use is still relatively slow. To date, fewer than ten mucosal vaccines have been approved. Only seven mucosal vaccines against coronavirus disease 2019 (COVID-19) are under investigation in clinical trials. A representative vaccine is the adenovirus type-5 vectored COVID-19 vaccine (Ad5-nCoV) developed by Chen and coworkers, which is currently in phase III clinical trials. The reason for the limited progress of mucosal vaccines may be the complicated mucosal barriers. Therefore, this review summarizes the characteristics of mucosal barriers and highlights strategies to overcome these barriers for effective mucosal vaccine delivery.

11.
J Control Release ; 345: 494-511, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35337940

RESUMEN

Abnormal immune cell functions are commonly related to various diseases, including cancer, autoimmune diseases, and infectious diseases. Messenger RNA (mRNA)-based therapy can regulate the functions of immune cells or assign new functions to immune cells, thereby generating therapeutic immune responses to treat these diseases. However, mRNA is unstable in physiological environments and can hardly enter the cytoplasm of target cells; thus, effective mRNA delivery systems are critical for developing mRNA therapy. The two mRNA vaccines of Pfizer-BioNTech and Moderna have demonstrated that lipid nanoparticles (LNPs) can deliver mRNA into dendritic cells (DCs) to induce immunization against severe acute respiratory syndrome coronavirus 2, which opened the floodgates to the development of mRNA therapy. Apart from DCs, other immune cells are promising targets for mRNA therapy. This review summarized the barriers to mRNA delivery and advances in mRNA delivery for regulating the functions of different immune cells.


Asunto(s)
COVID-19 , Nanopartículas , COVID-19/terapia , Vacunas contra la COVID-19 , Humanos , Liposomas , ARN Mensajero/genética , SARS-CoV-2/genética
12.
Cell Res ; 31(12): 1291-1307, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34518654

RESUMEN

Intestinal stem cell (ISC) differentiation is regulated precisely by a niche in the crypt, where lymphocytes may interact with stem and transient amplifying (TA) cells. However, whether and how lymphocyte-stem/TA cell contact affects ISC differentiation is largely unknown. Here, we uncover a novel role of T cell-stem/TA cell contact in ISC fate decisions. We show that intestinal lymphocyte depletion results in skewed ISC differentiation in mice, which can be rescued by T cell transfer. Mechanistically, integrin αEß7 expressed on T cells binds to E-cadherin on ISCs and TA cells, triggering E-cadherin endocytosis and the consequent Wnt and Notch signaling alterations. Blocking αEß7-E-cadherin adhesion suppresses Wnt signaling and promotes Notch signaling in ISCs and TA cells, leading to defective ISC differentiation. Thus, αEß7+ T cells regulate ISC differentiation at single-cell level through cell-cell contact-mediated αEß7-E-cadherin adhesion signaling, highlighting a critical role of the T cell-stem/TA cell contact in maintaining intestinal homeostasis.


Asunto(s)
Células Madre , Linfocitos T , Animales , Adhesión Celular , Diferenciación Celular , Linaje de la Célula , Integrinas , Mucosa Intestinal , Ratones , Células Madre/citología , Linfocitos T/citología , Vía de Señalización Wnt
13.
Se Pu ; 39(7): 730-743, 2021 Jul 08.
Artículo en Chino | MEDLINE | ID: mdl-34227371

RESUMEN

Qi-Yu-San-Long decoction (QYSLD) is a classic traditional Chinese medicine prescription consisting of ten types of herbal medicines, including Astragali Radix, Polygonati Odorati Rhizoma, Scolopendra, Pheretima, Solanum nigrum L., Hedyotis diffusa Willd., Coicis Semen, Euphorbia helioscopia L., Curcumae Rhizoma, and Fritillariae Cirrhosae Bulbus, combined in a ratio of 15∶5∶3∶3∶10∶10∶10∶3∶5∶3 by weight. QYSLD has been used to treat non-small cell lung cancer (NSCLC) for over 20 years in clinical practice, and its curative effect is considered credible. However, the chemical constituents of QYSLD have not been revealed because of their complexity, which has significantly hindered the systematic clarification of the efficacy of the materials and quality evaluation. In this study, a reliable strategy based on the data-independent acquisition (DIA) technology of ultra high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) combined with a targeted screening method was established to investigate the chemical components of QYSLD. A 2-µL aliquot from each vial was injected into a Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm) to separate complex components. The temperature of the column was 35 ℃, and the flow rate was set at 0.2 mL/min. The mobile phase consisted of 0.1% formic acid aqueous solution and acetonitrile. Detection was conducted using an Xevo G2-XS QTOF-MS with a LockSpray capable-electrospray interface. The data for complex components in QYSLD were collected by full-information tandem mass spectrometry (MS E) in the positive and negative ion modes. In the MSE mode, data acquisition was performed using a mass spectrometer by rapidly switching from a low-collision-energy (CE) scan to a high-CE scan during a single LC run. Thus, accurate precursor and fragment ions were collected in a single run, which was helpful for the structural elucidation of multiple components in QYSLD. In addition, systematic information on isolated chemical compounds was collected and distinguished from the ten individual herbs in QYSLD using databases such as China Academic Journals Full-text database (CNKI), PubMed, Web of Science, Medline, and ChemSpider. Accordingly, a self-building library of QYSLD, including the component name, molecular formula, and structure of the components from the herbs, was established. Subsequently, the raw MSE data of the collected samples and the self-building chemical composition library were imported into a natural product post-processing screening (UNIFI) platform for targeted screening of the chemical components in QYSLD. The parameters for UNIFI platform were as follows: the retention time deviation was ±0.1 min; an error margin of no more than 5×10 -6 for the identified compounds was allowed; positive adducts, including [M+H]+and [M+Na]+, were selected; and negative adducts, including [M-H]- and [M+HCOO]-, were selected. The results showed that a total of 166 compounds were initially identified, including 22 saponins, 13 alkaloids, 27 flavonoids, 32 terpenes, 20 amino acids, 16 phenylpropanoids, 9 organic acids, 6 sterols, 6 anthraquinones, and 15 other components. Among them, sixteen components were confirmed unambiguously with the reference substances. To better understand the chemical contribution of individual herbs to the entire decoction, the attributes of each component were summarized. This study provides a foundation for exploring the pharmacodynamic substances of QYSLD.


Asunto(s)
Medicamentos Herbarios Chinos , China , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/análisis , Espectrometría de Masas
14.
Cancer Immunol Res ; 9(8): 967-980, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34131019

RESUMEN

Immune cell infiltration is important for predicting the clinical outcomes of colorectal cancer. Integrin ß7 (ITGB7), which is expressed on the surface of leukocytes, plays an essential role in the homing of immune cells to gut-associated lymphoid tissue and facilitating the retention of lymphocytes in gut epithelium; however, its role in colorectal cancer pathogenesis is poorly explored. Here, we found that the number of ß7+ cells decreased significantly in tumor tissue compared with adjacent normal tissue. ß7 expression decreased in tumor-derived compared with normal tissue-derived CD8+ T cells. With bulk RNA expression data from public platforms, we demonstrated that higher ITGB7 expression correlated with longer patient survival, higher cytotoxic immune cell infiltration, lower somatic copy-number alterations, decreased mutation frequency of APC and TP53, and better response to immunotherapy. The possible cell-cell interactions mediated by ITGB7 and its ligands MAdCAM-1, VCAM-1, and CDH1 were investigated using public single-cell RNA sequencing data. ITGB7 deficiency led to exaggerated tumorigenesis and progression in both Apcmin /+ spontaneous and MC38 orthotopic models of colorectal cancer, which could be due to a reduced infiltration of activated CD8+ T cells, effector memory CD8+ T cells, IFNγ+ CD8+ T cells, IFNγ+ natural killer cells, CD103+ dendritic cells, and other immune cell subsets that are essential players in antitumor immunity. In conclusion, our data revealed that ITGB7 could inhibit the tumorigenesis and progression of colorectal cancer by maintaining antitumor immunity.


Asunto(s)
Neoplasias Colorrectales/inmunología , Inmunoterapia/métodos , Cadenas beta de Integrinas/uso terapéutico , Neoplasias Colorrectales/mortalidad , Humanos , Cadenas beta de Integrinas/farmacología , Análisis de Supervivencia
15.
Sheng Li Xue Bao ; 73(2): 151-159, 2021 Apr 25.
Artículo en Chino | MEDLINE | ID: mdl-33903877

RESUMEN

Integrins are a large family of heterodimeric cell adhesion molecules composed of α and ß subunits. Through interaction with their specific ligands, integrins mediate cell-cell and cell-extracellular matrix interactions. Via outside-in signaling, integrins can recruit cytoplasmic proteins to their intracellular domains and then cluster into supramolecular structures and trigger downstream signaling. Integrin activation is associated with a global conformation rearrangement from bent to extended in ectodomains and the separation of α and ß subunit cytoplasmic domains. During cell migration, integrins regulate the focal adhesion dynamics and transmit forces between the extracellular matrix and the cell cytoskeleton. In tumor microenvironment, integrins on multiple kinds of cells could be activated, which modulates cell migration into tumor and contributes to angiogenesis and tumor metastasis. Here, we review the mechanism of integrin activation, dynamics of focal adhesions during cell migration and tumor metastasis.


Asunto(s)
Adhesiones Focales , Integrinas , Adhesión Celular , Moléculas de Adhesión Celular , Transducción de Señal
16.
BMC Psychiatry ; 21(1): 154, 2021 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-33726694

RESUMEN

BACKGROUND: The experiences of professionals in well-established recovery-oriented programs are valuable for professionals in similar practice settings. This study explored professionals' experiences with providing recovery-oriented services in community psychiatric rehabilitation organizations. METHODS: Semi-structured interviews were conducted with 14 professionals from five recovery-oriented psychiatric rehabilitation organizations in Taiwan. The interviews were recorded and transcribed verbatim. Thematic analysis was used for the qualitative data analysis. RESULTS: The analyses documented three main themes with 13 subthemes. Recovery-oriented service implementation included seven subthemes: Enabling clients to set their own goals and make decisions, using a strengths-based approach, establishing partnerships with clients, improving individuals' self-acceptance, encouraging community participation, seeking family, peer, and organizational support, and building team collaboration. Problems with implementing recovery-oriented services included limited policy and organizational support, a lack of understanding of recovery among professionals, stigma, clients' lack of motivation or self-confidence in their own ability to achieve recovery, and passive or overprotective family members. Strategies to resolve implementation problems included policy changes and organizational support, improving the recovery competence and confidence of professionals, and family and public education. CONCLUSIONS: To date, this is the first known study examining the perspectives of mental health professionals who have experience implementing recovery-oriented services in Asia. The participants identified family collaboration, anti-stigma efforts, and changes in policy and attitudes as critical to successful implementation and delivery of recovery-oriented services.


Asunto(s)
Personal de Salud , Trastornos Mentales , Asia , Humanos , Trastornos Mentales/terapia , Grupo Paritario , Investigación Cualitativa , Taiwán
17.
J Am Chem Soc ; 142(10): 4820-4832, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32067448

RESUMEN

The study of the formation, characterization, and functionality of isolated surface hydrides on solid materials is a formidable task because of the complexity of solid surfaces and the difficulty of analyzing structures in solids. Herein, we found the formation of indium (In) hydride species supported by CHA zeolites. The In hydrides were formed by treatment of an In-exchanged CHA zeolite (In-CHA) with H2 at high temperatures (>773 K). In situ Fourier transform infrared (FTIR) spectroscopy and density functional theory (DFT) calculations revealed that an [InH2]+ ion on a framework anionic site is a plausible structure. In-CHA exhibited high selectivity and durable catalytic activity for the nonoxidative dehydrogenation of ethane for at least 90 h. Kinetic and in situ spectroscopic studies as well as transition state (TS) calculations suggested that [InH2]+ ions serve as catalytically active sites for selective dehydrogenation using In-CHA.

18.
J Neuroimmunol ; 332: 78-90, 2019 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-30981049

RESUMEN

Multiple sclerosis (MS) is an inflammatory demyelinating disease of CNS. Astragalus polysaccharides (APS), the main active extract from astragalus membranaceus which is a kind of traditional Chinese medicinal herb, is associated with a variety of immunomodulatory activities. We have evaluated the therapeutic effects of APS in the animal model of MS, experimental autoimmune encephalomyelitis (EAE). It was found that APS could effectively alleviate EAE through inhibiting MOG35-55-specific T cell proliferation and reducing the expression of proinflammatory cytokines, which is mediated by up-regulating the expression of PD-1/PD-Ls signaling pathway. Our results demonstrated that EAE could be suppressed significantly by APS administration. It indicated that APS might be a potential of developing innovative drug for the therapy of MS.


Asunto(s)
Antiinflamatorios/uso terapéutico , Astragalus propinquus/química , Antígeno B7-H1/biosíntesis , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Fitoterapia , Gomas de Plantas/uso terapéutico , Proteína 2 Ligando de Muerte Celular Programada 1/biosíntesis , Receptor de Muerte Celular Programada 1/biosíntesis , Transducción de Señal/efectos de los fármacos , Animales , Antiinflamatorios/farmacología , Antígeno B7-H1/genética , Antígeno B7-H1/fisiología , Citocinas/biosíntesis , Citocinas/genética , Encefalomielitis Autoinmune Experimental/inducido químicamente , Femenino , Inflamación , Ratones , Ratones Endogámicos C57BL , Glicoproteína Mielina-Oligodendrócito/toxicidad , Fragmentos de Péptidos/toxicidad , Gomas de Plantas/farmacología , Proteína 2 Ligando de Muerte Celular Programada 1/genética , Proteína 2 Ligando de Muerte Celular Programada 1/fisiología , Receptor de Muerte Celular Programada 1/genética , Receptor de Muerte Celular Programada 1/fisiología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Médula Espinal/efectos de los fármacos , Médula Espinal/inmunología , Médula Espinal/patología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/patología , Regulación hacia Arriba/efectos de los fármacos
19.
J Antibiot (Tokyo) ; 72(6): 397-406, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30894676

RESUMEN

The synthesis of functionalized pyroglutamates 15 and 16 could be achieved by the application of recently developed diastereodivergent asymmetric Michael addition reaction of iminoglycinate 7 to ethyl γ-silyloxycrotonate with >98:<2 diastereoselectivity followed by hydrolysis and lactamization. Formal syntheses of (-)-isoretronecanol and (+)-laburnine as well as a concise enantioselective synthesis of (+)-turneforcidine could be achieved from functionalized pyroglutamates 15 or 16.


Asunto(s)
Alcaloides de Pirrolicidina/síntesis química , Catálisis , Estructura Molecular , Alcaloides de Pirrolicidina/química , Estereoisomerismo
20.
PLoS One ; 11(7): e0159426, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27437939

RESUMEN

Although IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, its etiology remains only partly understood. It is clear that the pathogenesis of IgAN involves the formation of macromolecular IgA1 complexes and increased levels of serum IgA1 and IgA1-immune complexes(IC), due to defective IgA1 clearance. Previous studies suggest that the blood and tissue myeloid cell-expressed IgA Fc receptor (FcαR/CD89) mediates IgA-IC clearance and its dysfunction, via decreased activity or excessive levels of soluble FcαR/sCD89 induces IgAN. Such a mechanism requires robust stimulation of IgAN levels via forced expression of CD89. In the absence of unequivocal evidence supporting such a mechanism to date, we attempted to test the extent of CD89-evoked IgAN by generating a transgenic mouse strain expressing human CD89 under the control of murine CD14 promotor. No deposition of IgA-CD89 complexes or glomerulonephritis was detected, however. Further studies showed that elimination of murine IgA was mediated by Kupffer cells. In patients, however, CD89/IgA complexes were detected, and injection of patient IgA induced IgAN-like features in CD89 Tg mice. In transgenic mice, IgAN pathogenesis involves impaired clearance of abnormal IgA via CD89, primarily by the Kupffer cells. Conditional IgAN progression in CD89 transgenic mice thus reveals important aspects of IgAN pathogenesis.


Asunto(s)
Antígenos CD/sangre , Glomerulonefritis por IGA/genética , Inmunoglobulina A/sangre , Receptores Fc/sangre , Animales , Antígenos CD/inmunología , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica , Glomerulonefritis por IGA/sangre , Glomerulonefritis por IGA/fisiopatología , Humanos , Inmunoglobulina A/inmunología , Macrófagos del Hígado/metabolismo , Macrófagos del Hígado/patología , Masculino , Ratones , Ratones Transgénicos , Receptores Fc/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA