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1.
Front Immunol ; 13: 782475, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35422804

RESUMO

A RhoA-specific guanine nucleotide exchange factor, p190RhoGEF, was first cloned and identified in neuronal cells. In immune cells, we first reported the role of p190RhoGEF in B cells: expression of p190RhoGEF increased after CD40 stimulation and was required for CD40-mediated B cell activation and differentiation. We also showed that over-expression of p190RhoGEF negatively affected dendritic cell function in response to bacterial lipopolysaccharide (LPS). In this study, we examined the role of p190RhoGEF in macrophages using p190RhoGEF over-expressing transgenic (TG) mice. We found macrophages from TG mice to be more round than those from control mice, with enriched polymerized actin at the edge attached to the glass. TG macrophages also responded less to LPS: production of reactive oxygen species, phagocytosis, chemokine-dependent migration, and pro-inflammatory cytokine secretion were all reduced compared with the responses of macrophages from littermate (LTM) control mice. Furthermore, the classical M1 subset population was observed less in the peritoneal macrophages of TG mice than the LTM control mice during LPS-elicited peritoneal inflammation. When the activity of RhoA was inhibited in TG macrophages, their morphology and LPS responses became similar to those of the LTM macrophages. These results suggest that over-expression of p190RhoGEF in macrophages could reduce M1 polarization and inflammatory responses by regulating the actin cytoskeleton.


Assuntos
Fatores de Troca do Nucleotídeo Guanina , Lipopolissacarídeos , Animais , Linfócitos B , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Camundongos , Camundongos Transgênicos , ras-GRF1
2.
Sci Rep ; 6: 28765, 2016 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-27357731

RESUMO

The hydrodeoxygenation of a model compound of lignin-derived bio-oil, guaiacol, which can be obtained from the pyrolysis of biomass to bio-oil, has attracted considerable research attention because of its huge potential as a substitute for conventional fuels. In this study, platinum-loaded HY zeolites (Pt/HY) with different Si/Al molar ratios were used as catalysts for the hydrodeoxygenation of guaiacol, anisole, veratrole, and phenol to a range of hydrocarbons, such as cyclohexane. The cyclohexane (major product) yield increased with increasing number of acid sites. To produce bio-oil with the maximum level of cyclohexane and alkylated cyclohexanes, which would be suitable as a substitute for conventional transportation fuels, the Si/Al molar ratio should be optimized to balance the Pt particle-induced hydrogenation with acid site-induced methyl group transfer. The fuel properties of real bio-oil derived from the fast pyrolysis of cork oak was improved using the Pt/HY catalyst.


Assuntos
Biocombustíveis , Guaiacol/química , Alumínio/química , Anisóis/química , Biocombustíveis/análise , Catálise , Cicloexanos/química , Concentração de Íons de Hidrogênio , Platina/química , Quercus/química , Dióxido de Silício/química , Zeolitas/química
3.
J Immunol ; 197(3): 942-52, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27335501

RESUMO

A novel adaptor protein was identified by analyzing phosphotyrosine proteomes from membrane rafts of activated T cells. This protein showed sequence similarity to a well-known T cell adaptor protein, adhesion and degranulation-promoting adaptor protein (ADAP); therefore, the novel protein was designated activation-dependent, raft-recruited ADAP-like phosphoprotein (ARAP). Suppression of ARAP impaired the major signaling pathways downstream of the TCR. ARAP associated with the Src homology 2 domain of Src homology 2-containing leukocyte protein of 76 kDa via the phosphorylation of two YDDV motifs in response to TCR stimulation. ARAP also mediated integrin activation but was not involved in actin polymerization. The results of this study indicate that a novel T cell adaptor protein, ARAP, plays a unique role in T cells as a part of both the proximal activation signaling and inside-out signaling pathways that result in integrin activation and T cell adhesion.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Adesão Celular/imunologia , Ativação Linfocitária/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linhagem Celular , Humanos , Imuno-Histoquímica , Integrinas/imunologia , Integrinas/metabolismo , Microdomínios da Membrana/imunologia , Microdomínios da Membrana/metabolismo , Reação em Cadeia da Polimerase , Transdução de Sinais/imunologia , Linfócitos T/metabolismo
4.
J Nanosci Nanotechnol ; 15(1): 527-31, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328395

RESUMO

Upgrading of bio-oil through catalytic hydrodeoxygenation (HDO) reaction was investigated for guaiacol as a model compound. A batch reactor was used for the reaction condition of 40 bar and 250 degrees C. The target product was cyclohexane. Pt/Al-SBA-15 with the Si/Al ratios of 20, 40, and 80 and Pt/HZSM-5 were used as the catalyst. The SBA-15 catalysts were characterized by N2 adsorption-desorption, X-ray diffraction analysis, and temperature programmed desorption of ammonia. The order of cyclohexane yield was Pt/Al-SBA-15 (Si/Al = 20) > Pt/Al-SBA-15(40) > Pt/Al-SBA-15 (80), indicating that the quantity of acid sites plays an important role in the HDO reaction. On the other hand, Pt/HZSM-5 led to a very low cyclohexane yield, in spite of its abundant strong acid sites, due to its small pore size.


Assuntos
Alumínio/química , Guaiacol/química , Oxigênio/química , Platina/química , Dióxido de Silício/química , Amônia/química , Catálise , Cicloexanos/química , Porosidade , Temperatura
5.
J Nanosci Nanotechnol ; 13(4): 2879-84, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23763174

RESUMO

CMK-8, a mesoporous carbon material, was activated using different methods for the adsorption of low-concentration airborne formaldehyde. KOH and ammonia treatments were used to activate CMK-8. A CMK-8 sample was treated with KOH first followed by an ammonia-treatment at 700 degrees C to determine the effect of a combination of the two treatment methods. The adsorbents prepared were characterized by X-ray diffraction, N2 adsorption-desorption and X-ray photoelectron spectroscopy. The KOH treatment increased the concentration of oxygen functional groups, whereas the ammonia-treatment generated a significant amount of nitrogen functional groups. The formaldehyde adsorption efficiency was highest when both KOH- and ammonia-treatments were applied to CMK-8. The ammonia-treated CMK-8 exhibited higher formaldehyde adsorption ability than the KOH-treated one, whereas non-activated CMK-8 showed the lowest formaldehyde adsorption efficiency. The number of nitrogen functional groups and the specific surface area appeared to significantly affect the formaldehyde adsorption capability of the adsorbents, whereas oxygen functional groups played a less important role.

6.
Nanoscale Res Lett ; 7(1): 7, 2012 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-22221425

RESUMO

The removal of formaldehyde at low concentrations is important in indoor air pollution research. In this study, mesoporous carbon with a large specific surface area was used for the adsorption of low-concentration indoor formaldehyde. A mesoporous carbon material, CMK-3, was synthesized using the nano-replication method. SBA-15 was used as a mesoporous template. The surface of CMK-3 was activated using a 2N H2SO4 solution and NH3 gas to prepare CMK-3-H2SO4 and CMK-3-NH3, respectively. The activated samples were characterized by N2 adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy. The formaldehyde adsorption performance of the mesoporous carbons was in the order of CMK-3-NH3 > CMK-3-H2SO4 > CMK-3. The difference in the adsorption performance was explained by oxygen and nitrogen functional groups formed during the activation process and by the specific surface area and pore structure of mesoporous carbon.

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