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1.
J Immunol ; 203(10): 2712-2723, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31597705

RESUMO

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.


Assuntos
Galectina 3/sangue , Galectina 3/metabolismo , Galectina 3/farmacologia , Resistência à Insulina , Insulinas/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Animais , Proteínas Sanguíneas , Membrana Celular/metabolismo , Galectina 3/genética , Galectinas , Células HEK293 , Humanos , Inflamassomos/metabolismo , Insulinas/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Recombinantes/farmacologia , Células THP-1 , Transfecção
2.
Cytokine ; 120: 115-124, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31055218

RESUMO

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.


Assuntos
Inflamassomos/metabolismo , Vírus da Influenza A/imunologia , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Infiltração de Neutrófilos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Inflamação/patologia , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Infecções por Orthomyxoviridae/virologia , Transdução de Sinais
3.
Pharm Res ; 36(8): 121, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31214786

RESUMO

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.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Cisplatino/farmacocinética , Lipossomos/química , Neoplasias Pulmonares/tratamento farmacológico , Sesquiterpenos/farmacocinética , Células A549 , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Colesterol/química , Cisplatino/administração & dosagem , Composição de Medicamentos , Liberação Controlada de Fármacos , Xenoenxertos , Humanos , Camundongos Endogâmicos C57BL , Tamanho da Partícula , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Polietilenoglicóis/química , Sesquiterpenos/administração & dosagem , Distribuição Tecidual
4.
J Immunol ; 198(3): 1119-1129, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28039299

RESUMO

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.


Assuntos
Lúpus Eritematoso Sistêmico/etiologia , Células Mieloides/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Animais , Complexo Antígeno-Anticorpo/metabolismo , Autoimunidade , Quimiocinas/fisiologia , Citocinas/fisiologia , Glomerulonefrite/etiologia , Mediadores da Inflamação/fisiologia , Rim/patologia , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/patologia , Camundongos , Nefrite Intersticial/etiologia , Terpenos/toxicidade
5.
Am J Pathol ; 186(3): 678-90, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26801735

RESUMO

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.


Assuntos
Mieloma Múltiplo/tratamento farmacológico , Osteólise/tratamento farmacológico , Peptídeos/farmacologia , Trombospondina 1/efeitos dos fármacos , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Bortezomib/uso terapêutico , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Mieloma Múltiplo/patologia , Osteogênese/efeitos dos fármacos , Osteólise/patologia , Peptídeos/uso terapêutico , Distribuição Aleatória , Transdução de Sinais/efeitos dos fármacos , Trombospondina 1/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Microambiente Tumoral
6.
J Immunol ; 195(10): 4962-72, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26466953

RESUMO

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.


Assuntos
Caspase 1/imunologia , Caspase 8/imunologia , Criptococose/imunologia , Cryptococcus neoformans/imunologia , Inflamassomos/imunologia , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Caspase 1/genética , Caspase 8/genética , Linhagem Celular Tumoral , Criptococose/genética , Criptococose/patologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Humanos , Imunidade Inata/genética , Inflamassomos/genética , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR , Transdução de Sinais/genética , Transdução de Sinais/imunologia
7.
Cytokine ; 81: 101-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26978550

RESUMO

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.


Assuntos
Reações Cruzadas/imunologia , Citocinas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Macrófagos/imunologia , Staphylococcus aureus/imunologia , Animais , Western Blotting , Células Cultivadas , Citocinas/genética , Interações Hospedeiro-Patógeno/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Especificidade da Espécie , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Fator de Necrose Tumoral alfa/imunologia
8.
J Vasc Res ; 52(5): 306-20, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26910059

RESUMO

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.


Assuntos
Calbindina 2/metabolismo , Lesões das Artérias Carótidas/metabolismo , Colágeno Tipo I/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Neointima , Animais , Calbindina 2/deficiência , Calbindina 2/genética , Artérias Carótidas/metabolismo , Artérias Carótidas/patologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/patologia , Proliferação de Células , Células Cultivadas , Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I , Modelos Animais de Doenças , Ligadura , Camundongos Knockout , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Músculo Liso Vascular/cirurgia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Transdução de Sinais , Fatores de Tempo , Transfecção , Fator de Crescimento Transformador beta/farmacologia , Regulação para Cima
9.
Infect Immun ; 82(2): 882-92, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24478101

RESUMO

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.


Assuntos
Proteínas de Transporte/metabolismo , Inflamassomos/metabolismo , Microsporum/imunologia , Animais , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Técnicas de Silenciamento de Genes , Humanos , Interleucina-1beta/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microsporum/isolamento & purificação , Monócitos/imunologia , Monócitos/microbiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Tinha do Couro Cabeludo/imunologia , Tinha do Couro Cabeludo/microbiologia
10.
Avian Pathol ; 43(4): 325-32, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24911937

RESUMO

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.


Assuntos
Anticorpos Antivirais/sangue , Gansos , Doença de Newcastle/patologia , Vírus da Doença de Newcastle/patogenicidade , Animais , Feminino , Masculino , Doença de Newcastle/imunologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/imunologia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Baço/virologia , Timo/virologia , Carga Viral
11.
ACS Omega ; 9(4): 4474-4485, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38313524

RESUMO

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.
Endocrinology ; 164(3)2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36631163

RESUMO

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.


Assuntos
Receptores dos Hormônios Tireóideos , Células Fotorreceptoras Retinianas Cones , Camundongos , Animais , Células Fotorreceptoras Retinianas Cones/metabolismo , Receptores dos Hormônios Tireóideos/genética , Receptores dos Hormônios Tireóideos/metabolismo , Hormônios Tireóideos/metabolismo , Opsinas de Bastonetes/genética , Opsinas de Bastonetes/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Mutação
13.
Nat Commun ; 14(1): 642, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36746963

RESUMO

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.


Assuntos
Vírus da Influenza A , Microbiota , Humanos , Animais , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Acetatos/farmacologia , Antivirais
14.
Org Lett ; 25(49): 8819-8823, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38032844

RESUMO

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.

15.
Life Sci Alliance ; 6(10)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37495396

RESUMO

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.


Assuntos
Anemia , Lúpus Eritematoso Sistêmico , Animais , Humanos , Camundongos , Anemia/etiologia , Medula Óssea/metabolismo , RNA , Receptor 8 Toll-Like
16.
J Neurosci ; 31(31): 11118-25, 2011 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-21813673

RESUMO

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.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas do Olho/metabolismo , Células Fotorreceptoras de Vertebrados/classificação , Células Fotorreceptoras de Vertebrados/fisiologia , Retina , Células-Tronco/fisiologia , Receptores beta dos Hormônios Tireóideos/metabolismo , Animais , Animais Recém-Nascidos , Fatores de Transcrição de Zíper de Leucina Básica/deficiência , Fatores de Transcrição de Zíper de Leucina Básica/genética , Diferenciação Celular , Eletrorretinografia , Embrião de Mamíferos , Proteínas do Olho/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Fluorescência Verde/genética , Luz , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação/genética , Opsinas/metabolismo , RNA Mensageiro/metabolismo , Receptores da Tireotropina/deficiência , Retina/citologia , Retina/embriologia , Retina/crescimento & desenvolvimento , Receptores beta dos Hormônios Tireóideos/deficiência , Receptores beta dos Hormônios Tireóideos/genética
17.
Am J Pathol ; 178(6): 2573-86, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21641382

RESUMO

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.


Assuntos
Nefropatias Diabéticas/complicações , Rim/patologia , Proteinúria/complicações , Proteinúria/prevenção & controle , Trombospondina 1/metabolismo , Fator de Crescimento Transformador beta/antagonistas & inibidores , Albuminúria/complicações , Albuminúria/patologia , Albuminúria/urina , Sequência de Aminoácidos , Animais , Creatinina/urina , Derme/efeitos dos fármacos , Derme/patologia , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/urina , Modelos Animais de Doenças , Fibronectinas/metabolismo , Inflamação/complicações , Inflamação/patologia , Injeções Intraperitoneais , Rim/efeitos dos fármacos , Rim/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Peptídeos/administração & dosagem , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Fosforilação/efeitos dos fármacos , Proteinúria/urina , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/urina , Cicatrização/efeitos dos fármacos
18.
Cell Mol Neurobiol ; 32(5): 815-28, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22198557

RESUMO

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.


Assuntos
Comportamento Animal/fisiologia , Hormônio Liberador da Corticotropina/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/patologia , Sistema Hipófise-Suprarrenal/metabolismo , Sistema Hipófise-Suprarrenal/patologia , Animais , Ansiedade/metabolismo , Ansiedade/patologia , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Hipófise/metabolismo , Sono REM
19.
Artigo em Inglês | MEDLINE | ID: mdl-36554711

RESUMO

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.


Assuntos
Carbono , Celulose , Carbono/química , Biomassa , Temperatura , Celulose/química , Oxigênio/química
20.
Am J Pathol ; 177(4): 1710-24, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20724603

RESUMO

Amino acids 17-35 of the thrombospondin1 (TSP1) N-terminal domain (NTD) bind cell surface calreticulin to signal focal adhesion disassembly, cell migration, and anoikis resistance in vitro. However, the in vivo relevance of this signaling pathway has not been previously determined. We engineered local in vivo expression of the TSP1 calreticulin-binding sequence to determine the role of TSP1 in tissue remodeling. Surgical sponges impregnated with a plasmid encoding the secreted calreticulin-binding sequence [NTD (1-35)-EGFP] or a control sequence [mod NTD (1-35)-EGFP] tagged with enhanced green fluorescent protein were implanted subcutaneously in mice. Sponges expressing NTD (1-35)-EFGP formed a highly organized capsule despite no differences in cellular composition, suggesting stimulation of collagen deposition by the calreticulin-binding sequence of TSP1. TSP1, recombinant NTD, or a peptide of the TSP1 calreticulin-binding sequence (hep I) increased both collagen expression and matrix deposition by fibroblasts in vitro. TSP1 stimulation of collagen was inhibited by a peptide that blocks TSP1 binding to calreticulin, demonstrating the requirement for cell surface calreticulin. Collagen stimulation was independent of TGF-ß activity and Smad phosphorylation but was blocked by an Akt inhibitor, suggesting that signaling through the Akt pathway is important for regulation of collagen through TSP1 binding to calreticulin. These studies identify a novel function for the NTD of TSP1 as a mediator of collagen expression and deposition during tissue remodeling.


Assuntos
Calreticulina/metabolismo , Colágeno/metabolismo , Embrião de Mamíferos/citologia , Endotélio Vascular/citologia , Fibroblastos/citologia , Trombospondina 1/metabolismo , Animais , Aorta/citologia , Aorta/metabolismo , Apoptose , Western Blotting , Bovinos , Adesão Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Embrião de Mamíferos/metabolismo , Endotélio Vascular/metabolismo , Fibroblastos/metabolismo , Proteínas de Fluorescência Verde/genética , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Proteína Smad2/genética , Proteína Smad2/metabolismo , Trombospondina 1/genética , Alicerces Teciduais , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
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