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1.
J Immunol ; 203(10): 2712-2723, 2019 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-31597705

RESUMEN

The inflammasomes play critical roles in numerous pathological conditions largely through IL-1ß and/or IL-18. However, additional effectors have been implied from multiple studies. In this study, through two independent mass spectrometry-based secretome screening approaches, we identified galectin-3 as an effector protein of the NLRP3 inflammasome. Although the activation of AIM2 or NLRC4 inflammasome also led to galectin-3 secretion, only the NLRP3 inflammasome controlled the serum galectin-3 level under physiological condition. Mechanistically, active gasdermin D drove the nonexosomal secretion of galectin-3 through the plasma membrane pores. In vivo, high-fat diet-fed Nlrp3-/- mice exhibited decreased circulating galectin-3 compared with wild-type animals. Of note, the improved insulin sensitivity in such Nlrp3-/- mice was aggravated by infusion of recombinant galectin-3. Moreover, galectin-3 was essential for insulin resistance induction in mice harboring the hyperactive Nlrp3A350V allele. Thus, the inflammasome-galectin-3 axis has been demonstrated as a promising target to intervene inflammasome and/or galectin-3 related diseases.


Asunto(s)
Galectina 3/sangre , Galectina 3/metabolismo , Galectina 3/farmacología , Resistencia a la Insulina , Insulinas/antagonistas & inhibidores , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Unión a Fosfato/metabolismo , Animales , Proteínas Sanguíneas , Membrana Celular/metabolismo , Galectina 3/genética , Galectinas , Células HEK293 , Humanos , Inflamasomas/metabolismo , Insulinas/metabolismo , Masculino , Ratones , Ratones Noqueados , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteínas Recombinantes/farmacología , Células THP-1 , Transfección
2.
Cytokine ; 120: 115-124, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31055218

RESUMEN

Host innate immune system is critical for combating invading microbes including Influenza A virus (IAV). As an important arm of the innate immunity, the NLRP3 inflammasome has been found essential for protecting host against IAV challenge, while the mechanism remained elusive. Here we found that mice carrying a gain-of-function mutation in the Nlrp3 gene (Nlrp3R258W) are strongly resistant to IAV infection. Upon H1N1 IAV infection, the Nlrp3R258W mice exhibited decreased weight loss, increased survival rate and attenuated lung damage compared with WT littermate controls. Mechanistically, the resistance of Nlrp3R258W mice to IAV infection was dependent on IL-1ß-mediated neutrophil recruitment. Upon IAV infection, mice carrying the Nlrp3R258W mutation produced more IL-1ß than WT mice in the lung, which enhanced neutrophil recruitment locally. The recruited neutrophils facilitated IAV clearance, so that the viral load in Nlrp3R258W mice was lower than that in control mice. Conversely, neutrophil depletion in Nlrp3R258W mice compromised IAV clearance. Taken together, our results demonstrate a previously undescribed mechanism by which hyperactivation of the NLRP3 Inflammasome protects mice from IAV infection through IL-1ß mediated neutrophil recruitment, thus suggest that positively fine tuning the physiological function of NLRP3 inflammasome can be beneficial for a mammalian host against IAV challenge.


Asunto(s)
Inflamasomas/metabolismo , Virus de la Influenza A/inmunología , Interleucina-1beta/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Infiltración Neutrófila , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Animales , Inflamación/patología , Pulmón/patología , Pulmón/virología , Ratones , Ratones Endogámicos C57BL , Mutación/genética , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Infecciones por Orthomyxoviridae/virología , Transducción de Señal
3.
Pharm Res ; 36(8): 121, 2019 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-31214786

RESUMEN

PURPOSE: ß-elemene and cisplatin combined chemotherapy currently is one of the most important settings available for lung cancer therapy in China. However, the clinical outcome is limited by their pharmacokinetic drawbacks. On the other hand, most of nanomedicines have failed in clinical development due to the huge differences between heterogeneous clinical tumor tissues and homogenous cell-derived xenografts. In this work, we fabricated a ß-elemene and cisplatin co-loaded liposomal system to effectively treat lung cancer. METHOD: In vitro cytotoxicity of co-loaded liposomes was studied by MTT, trypan and Hoechst/PI staining, and western blot in A549, A549/DDP, and LCC cells. In vivo antitumor efficacy was evaluated in cell-derived and clinically relevant patient-derived xenografts. RESULTS: Co-loaded liposomes were more cytotoxic to cancer cells, especially than the combination of single-loaded liposomes, benefiting from their simultaneous drug internalization and release. As a result, they exhibited desirable therapeutic outcome in both cell-derived and patient-derived xenografts. CONCLUSION: ß-elemene and cisplatin co-loaded liposomes are a clinically promising candidate for effective lung cancer therapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Cisplatino/farmacocinética , Liposomas/química , Neoplasias Pulmonares/tratamiento farmacológico , Sesquiterpenos/farmacocinética , Células A549 , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Supervivencia Celular/efectos de los fármacos , Colesterol/química , Cisplatino/administración & dosificación , Composición de Medicamentos , Liberación de Fármacos , Xenoinjertos , Humanos , Ratones Endogámicos C57BL , Tamaño de la Partícula , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Polietilenglicoles/química , Sesquiterpenos/administración & dosificación , Distribución Tisular
4.
J Immunol ; 198(3): 1119-1129, 2017 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-28039299

RESUMEN

Systemic lupus erythematosus (SLE) is an autoimmune syndrome associated with severe organ damage resulting from the activation of immune cells. Recently, a role for caspase-1 in murine lupus was described, indicating an involvement of inflammasomes in the development of SLE. Among multiple inflammasomes identified, the NLRP3 inflammasome was connected to diverse diseases, including autoimmune encephalomyelitis. However, the function of NLRP3 in SLE development remains elusive. In this study, we explored the role of NLRP3 in the development of SLE using the pristane-induced experimental lupus model. It was discovered that more severe lupus-like syndrome developed in Nlrp3-R258W mice carrying the gain-of-function mutation. Nlrp3-R258W mutant mice exhibited significantly higher mortality upon pristane challenge. Moreover, prominent hypercellularity and interstitial nephritis were evident in the glomeruli of Nlrp3-R258W mice. In addition, hyperactivation of the NLRP3 inflammasome in this mouse line resulted in proteinuria and mesangial destruction. Importantly, all of these phenotypes were largely attributed to the Nlrp3-R258W mutation expressed in myeloid cells, because Cre recombinase-mediated depletion of this mutant from such cells rescued mice from experimental lupus. Taken together, our study demonstrates a critical role for NLRP3 in the development of SLE and suggests that modulating the inflammasome signal may help to control the inflammatory damage in autoimmune diseases, including lupus.


Asunto(s)
Lupus Eritematoso Sistémico/etiología , Células Mieloides/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/fisiología , Animales , Complejo Antígeno-Anticuerpo/metabolismo , Autoinmunidad , Quimiocinas/fisiología , Citocinas/fisiología , Glomerulonefritis/etiología , Mediadores de Inflamación/fisiología , Riñón/patología , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/patología , Ratones , Nefritis Intersticial/etiología , Terpenos/toxicidad
5.
Am J Pathol ; 186(3): 678-90, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26801735

RESUMEN

Transforming growth factor (TGF)-ß supports multiple myeloma progression and associated osteolytic bone disease. Conversion of latent TGF-ß to its biologically active form is a major regulatory node controlling its activity. Thrombospondin1 (TSP1) binds and activates TGF-ß. TSP1 is increased in myeloma, and TSP1-TGF-ß activation inhibits osteoblast differentiation. We hypothesized that TSP1 regulates TGF-ß activity in myeloma and that antagonism of the TSP1-TGF-ß axis inhibits myeloma progression. Antagonists (LSKL peptide, SRI31277) derived from the LSKL sequence of latent TGF-ß that block TSP1-TGF-ß activation were used to determine the role of the TSP1-TGF-ß pathway in mouse models of myeloma. TSP1 binds to human myeloma cells and activates TGF-ß produced by cultured human and mouse myeloma cell lines. Antagonists delivered via osmotic pump in an intratibial severe combined immunodeficiency CAG myeloma model or in a systemic severe combined immunodeficiency CAG-heparanase model of aggressive myeloma reduced TGF-ß signaling (phospho-Smad 2) in bone sections, tumor burden, mouse IL-6, and osteoclasts, increased osteoblast number, and inhibited bone destruction as measured by microcomputed tomography. SRI31277 reduced tumor burden in the immune competent 5TGM1 myeloma model. SRI31277 was as effective as dexamethasone or bortezomib, and SRI31277 combined with bortezomib showed greater tumor reduction than either agent alone. These studies validate TSP1-regulated TGF-ß activation as a therapeutic strategy for targeted inhibition of TGF-ß in myeloma.


Asunto(s)
Mieloma Múltiple/tratamiento farmacológico , Osteólisis/tratamiento farmacológico , Péptidos/farmacología , Trombospondina 1/efectos de los fármacos , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Animales , Antineoplásicos/uso terapéutico , Bortezomib/uso terapéutico , Diferenciación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Mieloma Múltiple/patología , Osteogénesis/efectos de los fármacos , Osteólisis/patología , Péptidos/uso terapéutico , Distribución Aleatoria , Transducción de Señal/efectos de los fármacos , Trombospondina 1/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Microambiente Tumoral
6.
J Immunol ; 195(10): 4962-72, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26466953

RESUMEN

Cryptococcus neoformans is an opportunistic fungal pathogen that causes cryptococcosis in immunocompromised patients as well as immunocompetent individuals. Host cell surface receptors that recognize C. neoformans have been widely studied. However, intracellular sensing of this pathogen is still poorly understood. Our previous studies have demonstrated that both biofilm and acapsular mutant of C. neoformans are able to activate the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome. In the current study, it was found that opsonization-mediated internalization of encapsulated C. neoformans also activated the canonical NLRP3-apoptosis-associated speck-like protein containing a CARD (ASC)-caspase-1 inflammasome. In addition, the internalized C. neoformans activated the noncanonical NLRP3-ASC-caspase-8 inflammasome as well, which resulted in robust IL-1ß secretion and cell death from caspase-1-deficient primary dendritic cells. Interestingly, we found that caspase-1 was inhibitory for the activation of caspase-8 in dendritic cells upon C. neorformans challenge. Further mechanistic studies showed that both phagolysosome membrane permeabilization and potassium efflux were responsible for C. neoformans-induced activation of either the canonical NLRP3-ASC-caspase-1 inflammasome or the noncanonical NLRP3-ASC-caspase-8 inflammasome. Moreover, challenge with zymosan also led to the activation of the noncanonical NLRP3-ASC-caspase-8 inflammasome in cells absent for caspase-1. Collectively, these findings uncover a number of novel signaling pathways for the innate immune response of host cells to C. neoformans infection and suggest that manipulating NLRP3 signaling may help to control fungal challenge.


Asunto(s)
Caspasa 1/inmunología , Caspasa 8/inmunología , Criptococosis/inmunología , Cryptococcus neoformans/inmunología , Inflamasomas/inmunología , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Caspasa 1/genética , Caspasa 8/genética , Línea Celular Tumoral , Criptococosis/genética , Criptococosis/patología , Células Dendríticas/inmunología , Células Dendríticas/patología , Activación Enzimática/genética , Activación Enzimática/inmunología , Humanos , Inmunidad Innata/genética , Inflamasomas/genética , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Ratones , Ratones Noqueados , Proteína con Dominio Pirina 3 de la Familia NLR , Transducción de Señal/genética , Transducción de Señal/inmunología
7.
Cytokine ; 81: 101-8, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26978550

RESUMEN

Staphylococcus aureus is one of the versatile Gram positive bacteria causing a range of diseases. Upon challenge, host immune cells recognize S. aureus and mount diverse immune responses including production of pro-inflammatory cytokines such as IL-1ß and TNF-α. These cytokines are important mediators of inflammation which can be detected via various immunological methods such as enzyme linked immunosorbent assay (ELISA) and immunoblotting. In the current study, we found that a number of clinical isolates as well as laboratory strains of S. aureus exhibited cross reactivity with ELISA antibodies for murine IL-1ß and TNF-α assays. This cross reactivity generates exaggerated false positive signals which can be a source of discrepancy for the understanding of real immune responses against S. aureus infection by host immune cells.


Asunto(s)
Reacciones Cruzadas/inmunología , Citocinas/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Macrófagos/inmunología , Staphylococcus aureus/inmunología , Animales , Western Blotting , Células Cultivadas , Citocinas/genética , Interacciones Huésped-Patógeno/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal/genética , Transducción de Señal/inmunología , Especificidad de la Especie , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Factor de Necrosis Tumoral alfa/inmunología
8.
J Vasc Res ; 52(5): 306-20, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26910059

RESUMEN

BACKGROUND/AIMS: The endoplasmic reticulum (ER) stress protein, calreticulin (CRT), is required for the production of TGF-ß-stimulated extracellular matrix (ECM) by fibroblasts. Since TGF-ß regulates vascular fibroproliferative responses and collagen deposition, we investigated the effects of CRT knockdown on vascular smooth-muscle cell (VSMC) fibroproliferative responses and collagen deposition. METHODS: Using a carotid artery ligation model of vascular injury, Cre-recombinase-IRES-GFP plasmid was delivered with microbubbles (MB) to CRT-floxed mice using ultrasound (US) to specifically reduce CRT expression in the carotid artery. RESULTS: In vitro, Cre-recombinase-mediated CRT knockdown in isolated, floxed VSMCs decreased the CRT transcript and protein, and attenuated the induction of collagen I protein in response to TGF-ß. TGF-ß stimulation of collagen I was partly blocked by the NFAT inhibitor 11R-VIVIT. Following carotid artery ligation, CRT staining was upregulated with enhanced expression in the neointima 14-21 days after injury. Furthermore, Cre-recombinase-IRES-GFP plasmid delivered by targeted US reduced CRT expression in the neointima of CRT-floxed mice and led to a significant reduction in neointima formation and collagen deposition. The neointimal cell number was also reduced in mice, with a local, tissue-specific knockdown of CRT. CONCLUSIONS: This work establishes a novel role for CRT in mediating VSMC responses to injury through the regulation of collagen deposition and neointima formation.


Asunto(s)
Calbindina 2/metabolismo , Traumatismos de las Arterias Carótidas/metabolismo , Colágeno Tipo I/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Neointima , Animales , Calbindina 2/deficiencia , Calbindina 2/genética , Arterias Carótidas/metabolismo , Arterias Carótidas/patología , Traumatismos de las Arterias Carótidas/genética , Traumatismos de las Arterias Carótidas/patología , Proliferación Celular , Células Cultivadas , Colágeno Tipo I/genética , Cadena alfa 1 del Colágeno Tipo I , Modelos Animales de Enfermedad , Ligadura , Ratones Noqueados , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/patología , Músculo Liso Vascular/cirugía , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/patología , Transducción de Señal , Factores de Tiempo , Transfección , Factor de Crecimiento Transformador beta/farmacología , Regulación hacia Arriba
9.
Infect Immun ; 82(2): 882-92, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24478101

RESUMEN

Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1ß (IL-1ß) into its mature form. To determine whether the inflammasome is involved in the host defense against M. canis infection, we challenged human monocytic THP-1 cells and mouse dendritic cells with a clinical strain of M. canis isolated from patients with tinea capitis. We found that M. canis infection triggered rapid secretion of IL-1ß from both THP-1 cells and mouse dendritic cells. Moreover, by using gene-specific shRNA and competitive inhibitors, we determined that M. canis-induced IL-1ß secretion was dependent on NLRP3. The pathways proposed for NLRP3 inflammasome activation, namely, cathepsin B activity, K(+) efflux, and reactive oxygen species production, were all required for the inflammasome activation triggered by M. canis. Meanwhile, Syk, Dectin-1, and Card9 were found to be involved in M. canis-induced IL-1ß secretion via regulation of pro-IL-1ß transcription. More importantly, our data revealed that M. canis-induced production of IL-1ß was dependent on the NLRP3 inflammasome in vivo. Together, this study unveils that the NLRP3 inflammasome exerts a critical role in host innate immune responses against M. canis infection, and our data suggest that diseases that result from M. canis infection might be controlled by regulating the activation of inflammasomes.


Asunto(s)
Proteínas Portadoras/metabolismo , Inflamasomas/metabolismo , Microsporum/inmunología , Animales , Células Cultivadas , Células Dendríticas/inmunología , Células Dendríticas/microbiología , Técnicas de Silenciamiento del Gen , Humanos , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Microsporum/aislamiento & purificación , Monocitos/inmunología , Monocitos/microbiología , Proteína con Dominio Pirina 3 de la Familia NLR , Tiña del Cuero Cabelludo/inmunología , Tiña del Cuero Cabelludo/microbiología
10.
Avian Pathol ; 43(4): 325-32, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24911937

RESUMEN

Outbreaks of Newcastle disease in flocks of geese with high morbidity and mortality in southern and eastern China have been reported frequently since the late 1990s, which broke the traditional view that geese are considered to be the natural reservoir of Newcastle disease virus (NDV) but show few or no clinical signs after infection. In this present study, geese were infected intranasally with a local strain of NDV. Clinical disease and gross pathology were observed. Serum and immune organs were collected from geese sequentially euthanized or after disease-associated death. We studied the histopathology of immune organs by haematoxylin and eosin staining and NDV fusion protein was detected in tissues by immunohistochemistry. At the same time, the SYBR Green I real-time polymerase chain reaction assay was used to detect the viral load from the collected samples. Serum samples were tested for NDV-specific antibodies and avian influenza virus (AIV)-specific antibodies by haemagglutination inhibition (HI) test. The results showed that severe lesions and numerous positive reactions of NDV antigen were detected in the immune organs. High viral loads developed in immune organs of infected geese, correlating with the severity of clinical signs and lesions in the tissues. Furthermore, the infected geese developed low HI antibody titres to both AIV and NDV. The present study showed that the replication and dissemination of the NDV isolate was widespread in immune organs of geese. The study revealed that waterfowl may not only be a natural reservoir of NDV but also become susceptible to disease and may play a major role in the epidemiology of Newcastle disease.


Asunto(s)
Anticuerpos Antivirales/sangre , Gansos , Enfermedad de Newcastle/patología , Virus de la Enfermedad de Newcastle/patogenicidad , Animales , Femenino , Masculino , Enfermedad de Newcastle/inmunología , Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/genética , Virus de la Enfermedad de Newcastle/inmunología , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Bazo/virología , Timo/virología , Carga Viral
11.
ACS Omega ; 9(4): 4474-4485, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38313524

RESUMEN

The goal of this research was to investigate the effects of torrefying temperature (220, 260, and 300 °C) on the physicochemical properties, kinetics, thermodynamic parameters, and reaction processes of Acer palmatum (AP) during the pyrolysis process. The kinetics of raw materials and torrefied biomass were studied by using three kinetic models, and the main function graph approach was employed to find the reaction mechanism. The torrefied biomass produced at temperatures of 220 °C (AP-220), 260 °C (AP-260), and 300 °C (AP-300) was thermogravimetrically analyzed at four different heating rates (5, 10, 15, and 20 °C/min). In comparison to the raw material, the average activation energy of torrefied biomass declined with increasing temperature, from 174.13 to 84.67 kJ/mol (FWO), 172.52 to 81.24 kJ/mol (KAS and DAEM). The volatile contents of AP and AP-220 are higher than those of AP-260 and AP-300, indicating that the random nucleation model occupies the central position. Compared with the raw biomass, the average Gibbs free energy (ΔG) of torrefied biomass increased from 157.97 to 195.38 kJ/mol. The mean enthalpy change (ΔH) during the torrefaction process is positive, while the mean entropy change (ΔS) of the torrefaction of biomass is negative, decreasing from 16.93 to -151.53 kJ/mol (FWO) and from 14.36 to -156.06 kJ/mol (KAS and DAEM). Overall, the findings provide a comprehensive understanding of the kinetics and improved features of torrefied biomass as a high-quality solid fuel.

12.
bioRxiv ; 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39253451

RESUMEN

Although dynamic alterations in transcriptional, translational, and metabolic programs have been described in T cells, the factors and pathways guiding these molecular shifts are poorly understood, with recent studies revealing a disassociation between transcriptional responses and protein expression following T cell receptor (TCR) stimulation. Previous studies identified interferon regulatory factor 5 (IRF5) in the transcriptional regulation of cytokines, chemotactic molecules and T effector transcription factors following TCR signaling. In this study, we identified T cell intrinsic IRF5 regulation of mTORC1 activity as a key modulator of CD40L protein expression. We further demonstrated a global shift in T cell metabolism, with alterations in glutamine metabolism accompanied by shifts in T cell populations at the single cell level due to loss of Irf5 . T cell conditional Irf5 knockout mice in a murine model of experimental autoimmune encephalomyelitis (EAE) demonstrated protection from clinical disease with conserved defects in mTORC1 activity and glutamine regulation. Together, these findings expand our mechanistic understanding of IRF5 as an intrinsic regulator of T effector function(s) and support the therapeutic targeting of IRF5 in multiple sclerosis. Sentence Summary: Findings provide new insight into the mechanisms by which T cell intrinsic IRF5 regulates the adaptive immune response via modulation of mTORC1 signaling, glutamine metabolism, and protein translation.

13.
Endocrinology ; 164(3)2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36631163

RESUMEN

The function of a hormone receptor requires mechanisms to control precisely where, when, and at what level the receptor gene is expressed. An intriguing case concerns the selective induction of thyroid hormone receptor ß2 (TRß2), encoded by Thrb, in the pituitary and also in cone photoreceptors, in which it critically regulates expression of the opsin photopigments that mediate color vision. Here, we investigate the physiological significance of a candidate enhancer for induction of TRß2 by mutagenesis of a conserved intron region in its natural context in the endogenous Thrb gene in mice. Mutation of e-box sites for bHLH (basic-helix-loop-helix) transcription factors preferentially impairs TRß2 expression in cones whereas mutation of nearby sequences preferentially impairs expression in pituitary. A deletion encompassing all sites impairs expression in both tissues, indicating bifunctional activity. In cones, the e-box mutations disrupt chromatin acetylation, blunt the developmental induction of TRß2, and ultimately impair cone opsin expression and sensitivity to longer wavelengths of light. These results demonstrate the necessity of studying an enhancer in its natural chromosomal context for defining biological relevance and reveal surprisingly critical nuances of level and timing of enhancer function. Our findings illustrate the influence of noncoding sequences over thyroid hormone functions.


Asunto(s)
Receptores de Hormona Tiroidea , Células Fotorreceptoras Retinianas Conos , Ratones , Animales , Células Fotorreceptoras Retinianas Conos/metabolismo , Receptores de Hormona Tiroidea/genética , Receptores de Hormona Tiroidea/metabolismo , Hormonas Tiroideas/metabolismo , Opsinas de Bastones/genética , Opsinas de Bastones/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Mutación
14.
Nat Commun ; 14(1): 642, 2023 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-36746963

RESUMEN

Pathogenic viral infections represent a major challenge to human health. Host immune responses to respiratory viruses are closely associated with microbiome and metabolism via the gut-lung axis. It has been known that host defense against influenza A virus (IAV) involves activation of the NLRP3 inflammasome, however, mechanisms behind the protective function of NLRP3 are not fully known. Here we show that an isolated bacterial strain, Bifidobacterium pseudolongum NjM1, enriched in the gut microbiota of Nlrp3-/- mice, protects wild-type but not Nlrp3 deficient mice against IAV infection. This effect depends on the enhanced production of type I interferon (IFN-I) mediated by NjM1-derived acetate. Application of exogenous acetate reproduces the protective effect of NjM1. Mechanistically, NLRP3 bridges GPR43 and MAVS, and promotes the oligomerization and signalling of MAVS; while acetate enhances MAVS aggregation upon GPR43 engagement, leading to elevated IFN-I production. Thus, our data support a model of NLRP3 mediating enhanced induction of IFN-I via acetate-producing bacterium and suggest that the acetate-GPR43-NLRP3-MAVS-IFN-I signalling axis is a potential therapeutic target against respiratory viral infections.


Asunto(s)
Virus de la Influenza A , Microbiota , Humanos , Animales , Ratones , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Inflamasomas/metabolismo , Acetatos/farmacología , Antivirales
15.
Org Lett ; 25(49): 8819-8823, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38032844

RESUMEN

Oxazines are an important class of compounds in oxazine ligands and medical chemistry. Here, we describe a linear-selective allylation of imines with allyl electrophiles via cross-electrophile coupling reactions, followed by cyclization with halogenated reagents, providing a new strategy to afford oxazine compounds with a tetrasubstituted carbon center. Mechanistic studies indicate that α-amino carbanion, generated by successive single-electron transfer processes, is a key intermediate for nucleophile attack on π-allylpalladium in photoredox/palladium catalysis.

16.
Life Sci Alliance ; 6(10)2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37495396

RESUMEN

Anemia commonly occurs in systemic lupus erythematosus, a disease characterized by innate immune activation by nucleic acids. Overactivation of cytoplasmic sensors by self-DNA or RNA can cause erythroid cell death, while sparing other hematopoietic cell lineages. Whereas chronic inflammation is involved in this mechanism, less is known about the impact of systemic lupus erythematosus on the BM erythropoietic niche. We discovered that expression of the endosomal ssRNA sensor human TLR8 induces fatal anemia in Sle1.Yaa lupus mice. We observed that anemia was associated with a decrease in erythromyeloblastic islands and a block in differentiation at the CFU-E to proerythroblast transition in the BM. Single-cell RNAseq analyses of isolated BM erythromyeloblastic islands from human TLR8-expressing mice revealed that genes associated with essential central macrophage functions including adhesion and provision of nutrients were down-regulated. Although compensatory stress erythropoiesis occurred in the spleen, red blood cell half-life decreased because of hemophagocytosis. These data implicate the endosomal RNA sensor TLR8 as an additional innate receptor whose overactivation causes acquired failure of erythropoiesis via myeloid cell dysregulation.


Asunto(s)
Anemia , Lupus Eritematoso Sistémico , Animales , Humanos , Ratones , Anemia/etiología , Médula Ósea/metabolismo , ARN , Receptor Toll-Like 8
17.
J Neurosci ; 31(31): 11118-25, 2011 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-21813673

RESUMEN

The typical mammalian visual system is based upon three photoreceptor types: rods for dim light vision and two types of cones (M and S) for color vision in daylight. However, the process that generates photoreceptor diversity and the cell type in which diversity arises remain unclear. Mice deleted for thyroid hormone receptor ß2 (TRß2) and neural retina leucine zipper factor (NRL) lack M cones and rods, respectively, but gain S cones. We therefore tested the hypothesis that NRL and TRß2 direct a common precursor to a rod, M cone, or S cone outcome using Nrl(b2/b2) "knock-in" mice that express TRß2 instead of NRL from the endogenous Nrl gene. Nrl(b2/b2) mice lacked rods and produced excess M cones in contrast to the excess S cones in Nrl(-/-) mice. Notably, the presence of both factors yielded rods in Nrl(+/b2) mice. The results demonstrate innate plasticity in postmitotic rod precursors that allows these cells to form three functional photoreceptor types in response to NRL or TRß2. We also detected precursor cells in normal embryonic retina that transiently coexpressed Nrl and TRß2, suggesting that some precursors may originate in a plastic state. The plasticity of the precursors revealed in Nrl(b2/b2) mice suggests that a two-step transcriptional switch can direct three photoreceptor fates: first, rod versus cone identity dictated by NRL, and second, if NRL fails to act, M versus S cone identity dictated by TRß2.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Proteínas del Ojo/metabolismo , Células Fotorreceptoras de Vertebrados/clasificación , Células Fotorreceptoras de Vertebrados/fisiología , Retina , Células Madre/fisiología , Receptores beta de Hormona Tiroidea/metabolismo , Animales , Animales Recién Nacidos , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Diferenciación Celular , Electrorretinografía , Embrión de Mamíferos , Proteínas del Ojo/genética , Regulación del Desarrollo de la Expresión Génica/genética , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas Fluorescentes Verdes/genética , Luz , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación/genética , Opsinas/metabolismo , ARN Mensajero/metabolismo , Receptores de Tirotropina/deficiencia , Retina/citología , Retina/embriología , Retina/crecimiento & desarrollo , Receptores beta de Hormona Tiroidea/deficiencia , Receptores beta de Hormona Tiroidea/genética
18.
Am J Pathol ; 178(6): 2573-86, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21641382

RESUMEN

Transforming growth factor-ß (TGF-ß) is key in the pathogenesis of diabetic nephropathy. Thrombospondin 1 (TSP1) expression is increased in diabetes, and TSP1 regulates latent TGF-ß activation in vitro and in diabetic animal models. Herein, we investigate the effect of blockade of TSP1-dependent TGF-ß activation on progression of renal disease in a mouse model of type 1 diabetes (C57BL/6J-Ins2(Akita)) as a targeted treatment for diabetic nephropathy. Akita and control C57BL/6 mice who underwent uninephrectomy received 15 weeks of thrice-weekly i.p. treatment with 3 or 30 mg/kg LSKL peptide, control SLLK peptide, or saline. The effects of systemic LSKL peptide on dermal wound healing was assessed in type 2 diabetic mice (db/db). Proteinuria (urinary albumin level and albumin/creatinine ratio) was significantly improved in Akita mice treated with 30 mg/kg LSKL peptide. LSKL treatment reduced urinary TGF-ß activity and renal phospho-Smad2/3 levels and improved markers of tubulointerstitial injury (fibronectin) and podocytes (nephrin). However, LSKL did not alter glomerulosclerosis or glomerular structure. LSKL did not increase tumor incidence or inflammation or impair diabetic wound healing. These data suggest that selective targeting of excessive TGF-ß activity through blockade of TSP1-dependent TGF-ß activation represents a therapeutic strategy for treating diabetic nephropathy that preserves the homeostatic functions of TGF-ß.


Asunto(s)
Nefropatías Diabéticas/complicaciones , Riñón/patología , Proteinuria/complicaciones , Proteinuria/prevención & control , Trombospondina 1/metabolismo , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Albuminuria/complicaciones , Albuminuria/patología , Albuminuria/orina , Secuencia de Aminoácidos , Animales , Creatinina/orina , Dermis/efectos de los fármacos , Dermis/patología , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/patología , Nefropatías Diabéticas/orina , Modelos Animales de Enfermedad , Fibronectinas/metabolismo , Inflamación/complicaciones , Inflamación/patología , Inyecciones Intraperitoneales , Riñón/efectos de los fármacos , Riñón/metabolismo , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Péptidos/administración & dosificación , Péptidos/química , Péptidos/farmacología , Péptidos/uso terapéutico , Fosforilación/efectos de los fármacos , Proteinuria/orina , Transducción de Señal/efectos de los fármacos , Proteína Smad2/metabolismo , Factor de Crecimiento Transformador beta/orina , Cicatrización de Heridas/efectos de los fármacos
19.
Cell Mol Neurobiol ; 32(5): 815-28, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22198557

RESUMEN

The corticotropin-releasing hormone (CRH) and its cognate receptors have been implicated in the pathophysiology of stress-related disorders. Hypersecretion of central CRH and elevated glucocorticoid levels, as a consequence of impaired feedback control, have been shown to accompany mood and anxiety disorders. However, a clear discrimination of direct effects of centrally hypersecreted CRH from those resulting from HPA axis activation has been difficult. Applying a conditional strategy, we have generated two conditional CRH-overexpressing mouse lines: CRH-COE ( Del ) mice overexpress CRH throughout the body, while CRH-COE ( APit ) mice selectively overexpress CRH in the anterior and intermediate lobe of the pituitary. Both mouse lines show increased basal plasma corticosterone levels and consequently develop signs of Cushing's syndrome. However, while mice ubiquitously overexpressing CRH exhibited increased anxiety-related behaviour, overexpression of CRH in the pituitary did not produce alterations in emotional behaviour. These results suggest that chronic hypercorticosteroidism alone is not sufficient to alter anxiety-related behaviour but rather that central CRH hyperdrive on its own or in combination with elevated glucocorticoids is responsible for the increase in anxiety-related behaviour. In conclusion, the generated mouse lines represent valuable animal models to study the consequences of chronic CRH overproduction and HPA axis activation.


Asunto(s)
Conducta Animal/fisiología , Hormona Liberadora de Corticotropina/metabolismo , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/patología , Sistema Hipófiso-Suprarrenal/metabolismo , Sistema Hipófiso-Suprarrenal/patología , Animales , Ansiedad/metabolismo , Ansiedad/patología , Femenino , Masculino , Ratones , Ratones Transgénicos , Especificidad de Órganos , Hipófisis/metabolismo , Sueño REM
20.
Artículo en Inglés | MEDLINE | ID: mdl-36554711

RESUMEN

Torrefaction is an effective method for upgrading biomass. Cedar torrefaction is carried out in a fixed bed reactor at the temperature of 200-300 °C. The structural parameters are obtained from elemental analysis and 13C nuclear magnetic resonance (NMR). Thermal degradation behavior of raw and torrefied cedar is monitored by thermogravimetry analysis. The results show that carbon structure varied during torrefaction has a significant effect on thermal degradation of cedar. Some unstable oxygen functional groups, such as C1 of hemicellulose, ß-O-4 linked bonds, and amorphous C6 of cellulose, are decomposed at mild torrefaction of torrefied temperature ≤ 200 °C. The temperature of maximum weight loss rate increases from 348 °C of raw cedar to 373 °C of C-200. The amorphous cellulose is partly re-crystallized at moderate torrefaction of torrefied temperature 200-250 °C. The aromaticity of torrefied cedar increases from 0.45 of C-200 to 0.73 of C-250. The covalent bond in the side chain of aromatic rings in cedar was further broken during torrefaction at severe torrefaction of torrefied temperature 250-300 °C. The area percentage of DTG mainly signed at 387 °C of C-300. The proton aromatic carbon increases from 12.35% of C-250 to 21.69% of C-300. These results will further facilitate the utilization of biomass for replacing fossil fuel to drive carbon neutrality.


Asunto(s)
Carbono , Celulosa , Carbono/química , Biomasa , Temperatura , Celulosa/química , Oxígeno/química
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