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BACKGROUND AND PURPOSE: Psoriasis is a common autoimmune skin disease that significantly diminishes patients' quality of life. Interactions between primary afferents of the somatosensory system and the cutaneous immune system mediate the pathogenesis of psoriasis. This study aims to elucidate the molecular mechanisms of how primary sensory neurons regulate psoriasis formation. EXPERIMENTAL APPROACH: Skin and total RNA were extracted from wild-type (WT) and ASH1-like histone lysine methyltransferase (Ash1l+/- ) mice in both naive and imiquimod (IMQ)-induced psoriasis models. Immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence-activated cell sorting (FACS) were then performed. Microfluidic chamber coculture was used to investigate the interaction between somatosensory neurons and bone marrow dendritic cells (BMDCs) ex vivo. Whole-cell patch clamp recordings were used to evaluate neuronal excitability after Ash1L haploinsufficiency in primary sensory neurons. KEY RESULTS: The haploinsufficiency of ASH1L, a histone methyltransferase, in primary sensory neurons causes both neurite hyperinnervation and increased neuronal excitability, which promote miR-let-7b release from primary afferents in the skin in a neuronal activity-dependent manner. With a 'GUUGUGU' core sequence, miR-let-7b functions as an endogenous ligand of toll-like receptor 7 (TLR7) and stimulates the activation of dermal dendritic cells (DCs) and interleukin (IL)-23/IL-17 axis, ultimately exacerbating the symptoms of psoriasis. Thus, by limiting miR-let-7b release from primary afferents, ASH1L prevents dermal DC activation and ameliorates psoriasis. CONCLUSION AND IMPLICATIONS: Somatosensory neuron ASH1L modulates the cutaneous immune system by limiting neuronal activity-dependent release of miR-let-7b, which can directly activate dermal DCs via TLR7 and ultimately lead to aggravated psoriatic lesion.
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MicroARNs , Psoriasis , Humanos , Animales , Ratones , Receptor Toll-Like 7/genética , Calidad de Vida , Psoriasis/etiología , Psoriasis/patología , Piel/patología , MicroARNs/genética , Neuronas/patología , Modelos Animales de Enfermedad , Proteínas de Unión al ADN , N-Metiltransferasa de Histona-LisinaRESUMEN
Adipose tissue macrophages (ATM) are key players in the development of obesity and associated metabolic inflammation which contributes to systemic metabolic dysfunction. We here found that fibroblast activation protein α (FAP), a well-known marker of cancer-associated fibroblast, is selectively expressed in murine and human ATM among adipose tissue-infiltrating leukocytes. Macrophage FAP deficiency protects mice against diet-induced obesity and proinflammatory macrophage infiltration in obese adipose tissues, thereby alleviating hepatic steatosis and insulin resistance. Mechanistically, FAP specifically mediates monocyte chemokine protein CCL8 expression by ATM, which is further upregulated upon high-fat-diet (HFD) feeding, contributing to the recruitment of monocyte-derived proinflammatory macrophages with no effect on their classical inflammatory activation. CCL8 overexpression restores HFD-induced metabolic phenotypes in the absence of FAP. Moreover, macrophage FAP deficiency enhances energy expenditure and oxygen consumption preceding differential body weight after HFD feeding. Such enhanced energy expenditure is associated with increased levels of norepinephrine (NE) and lipolysis in white adipose tissues, likely due to decreased expression of monoamine oxidase, a NE degradation enzyme, by Fap-/- ATM. Collectively, our study identifies FAP as a previously unrecognized regulator of ATM function contributing to diet-induced obesity and metabolic inflammation and suggests FAP as a potential immunotherapeutic target against metabolic disorders.
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Tejido Adiposo , Resistencia a la Insulina , Animales , Humanos , Ratones , Tejido Adiposo/metabolismo , Dieta Alta en Grasa , Inflamación/metabolismo , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Obesidad/metabolismoRESUMEN
Although alveolar macrophages (AMs) play important roles in preventing and eliminating pulmonary infections, little is known about their regulation in healthy animals. Since exposure to LPS often renders cells hyporesponsive to subsequent LPS exposures ("tolerant"), we tested the hypothesis that LPS produced in the intestine reaches the lungs and stimulates AMs, rendering them tolerant. We found that resting AMs were more likely to be tolerant in mice lacking acyloxyacyl hydrolase (AOAH), the host lipase that degrades and inactivates LPS; isolated Aoah-/- AMs were less responsive to LPS stimulation and less phagocytic than were Aoah+/+ AMs. Upon innate stimulation in the airways, Aoah-/- mice had reduced epithelium- and macrophage-derived chemokine/cytokine production. Aoah-/- mice also developed greater and more prolonged loss of body weight and higher bacterial burdens after pulmonary challenge with Pseudomonas aeruginosa than did wildtype mice. We also found that bloodborne or intrarectally-administered LPS desensitized ("tolerized") AMs while antimicrobial drug treatment that reduced intestinal commensal Gram-negative bacterial abundance largely restored the innate responsiveness of Aoah-/- AMs. Confirming the role of LPS stimulation, the absence of TLR4 prevented Aoah-/- AM tolerance. We conclude that commensal LPSs may stimulate and desensitize (tolerize) alveolar macrophages in a TLR4-dependent manner and compromise pulmonary immunity. By inactivating LPS in the intestine, AOAH promotes antibacterial host defenses in the lung.
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Hidrolasas de Éster Carboxílico , Macrófagos Alveolares , Animales , Ratones , Lipopolisacáridos/toxicidad , Pulmón , Macrófagos Alveolares/inmunología , Receptor Toll-Like 4 , Hidrolasas de Éster Carboxílico/metabolismoRESUMEN
Diabetes mellitus (DM) affects bone metabolism and causes osteoporosis. Musashi 1 (MSI1), a member of the Musashi family, regulates protein expression by targeting protein mRNA and has been reported to play an important role in osteogenic differentiation. Therefore, this paper attempts to explore the role of MSI1 in diabetic osteoporosis and discussing its specific mechanism. The glucose concentration for high glucose (HG) and control MC3T3-E1 cells were 30 and 5.5 mM. MC3T3-E1 cells induced by high glucose (HG) were used to simulate diabetic osteoporosis in vivo. The interaction between MSI1 and microtubule actin crosslinking factor 1 (MACF1) was confirmed by RNA Immunoprecipitation (RIP). The mRNA and protein expressions of MSI1 and MACF1 in MC3T3-E1 cells and HG-induced MC3T3-E1 cells after indicated transfection were tested by Real-time quantitative polymerase chain reaction (RT-qPCR) assay and western blot. After transfection, the proliferation, apoptosis, and osteogenic differentiation of HG-induced MC3T3-E1 cells were detected by cell counting kit (CCK)-8, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), alkaline phosphatase (ALP) activity assay, and alizarin red staining. The expression of Wnt/ß-catenin signaling pathway-related proteins in HG-induced MC3T3-E1 cells after transfection was detected by western blot. This work shows that MSI1 can combine with MACF1. The expression of MSI1 and MACF1 was increased in HG-induced MC3T3-E1 cells. Upregulation of MSI1 promoted the proliferative and differentiative capabilities, but inhibited the apoptosis of HG-insulted MC3T3-E1 cells, which could be reversed by MACF1 knockdown. MSI1 stabilizes MACF1 to suppress apoptosis and promote osteogenic differentiation in HG-induced MC3T3-E1 cells by inhibiting Wnt/ß-catenin signaling pathway.
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Osteoporosis , Vía de Señalización Wnt , Animales , Ratones , Apoptosis , Diferenciación Celular , Glucosa/farmacología , Glucosa/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Osteoblastos/metabolismo , Osteogénesis , Osteoporosis/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismoRESUMEN
Gualou Xiebai Decoction (GXD), a classic prescription, is widely used to dealing with inflammatory diseases in China for thousands of years. Abnormal metabolic state of bile acids (BAs) is confirmed to cause intestinal epithelial barrier dysfunction. In preliminary work, we observed that GXD could decrease intestinal permeability in hyperlipidemia mice. The present study aimed to explore the protective effect of GXD on intestinal mucosa in vitro. Caco-2 cell monolayer permeability among different groups was determined by measuring the concentrations of FITC-dextran in the lower compartments and transepithelial electrical resistance (TEER). Meanwhile, mRNA and protein expressions of tight junctions (TJs) were investigated. Generation of intracellular reactive oxygen species (ROS) and the ratio of cell apoptosis induced by BAs were assessed by fluorescence probe and flow cytometry. GXD was shown to keep the cell monolayer in low permeable status, increase TEER and mRNA and protein expressions of occludin (Ocln) and zonula occluden 2 (ZO2) remarkably in cells challenged with cholic acid (CA), deoxycholic acid (DCA) and glycocholic acid (GCA). However, no significant effects were uncovered against the pathological effects of taurocholic acid (TCA). Meanwhile, generation of ROS and increased levels of apoptotic cells caused by CA, DCA and GCA were dramatically decreased by GXD, which were not observed on TCA. GXD could significantly attenuate intestinal barrier dysfunction induced by BAs via TJs regulation, oxidative stress suppression and cell apoptosis decrease, but such effects and behind mechanisms differed among different kinds of BAs.
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Ácidos y Sales Biliares , Uniones Estrechas , Animales , Apoptosis , Ácidos y Sales Biliares/metabolismo , Ácidos y Sales Biliares/farmacología , Células CACO-2 , Medicamentos Herbarios Chinos , Humanos , Ratones , Estrés Oxidativo , Permeabilidad , Uniones Estrechas/metabolismoRESUMEN
The intestinal mucosal immune environment requires multiple immune cells to maintain homeostasis. Although intestinal B cells are among the most important immune cells, little is known about the mechanism that they employ to regulate immune homeostasis. In this study, we found that CD11b+ B cells significantly accumulated in the gut lamina propria and Peyer's patches in dextran sulfate sodium-induced colitis mouse models and patients with ulcerative colitis. Adoptive transfer of CD11b+ B cells, but not CD11b-/- B cells, effectively ameliorated colitis and exhibited therapeutic effects. Furthermore, CD11b+ B cells were found to produce higher levels of IgA than CD11b- B cells. CD11b deficiency in B cells dampened IgA production, resulting in the loss of their ability to ameliorate colitis. Mechanistically, CD11b+ B cells expressed abundant TGF-ß and TGF-ß receptor II, as well as highly activate phosphorylated Smad2/3 signaling pathway, consequently promoting the class switch to IgA. Collectively, our findings demonstrate that CD11b+ B cells are essential intestinal suppressive immune cells and the primary source of intestinal IgA, which plays an indispensable role in maintaining intestinal homeostasis.
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Linfocitos B/inmunología , Antígeno CD11b/inmunología , Colitis Ulcerosa/inmunología , Colitis/inmunología , Inmunoglobulina A Secretora/inmunología , Ganglios Linfáticos Agregados/inmunología , Traslado Adoptivo , Animales , Linfocitos B/patología , Antígeno CD11b/genética , Colitis/inducido químicamente , Colitis/patología , Colitis Ulcerosa/patología , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Humanos , Cambio de Clase de Inmunoglobulina , Mucosa Intestinal/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ganglios Linfáticos Agregados/patología , Transducción de Señal , Proteína Smad2/metabolismoRESUMEN
Oxidized phospholipids have diverse biological activities, many of which can be pathological, yet how they are inactivated in vivo is not fully understood. Here, we present evidence that a highly conserved host lipase, acyloxyacyl hydrolase (AOAH), can play a significant role in reducing the pro-inflammatory activities of two prominent products of phospholipid oxidation, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine. AOAH removed the sn-2 and sn-1 acyl chains from both lipids and reduced their ability to induce macrophage inflammasome activation and cell death in vitro and acute lung injury in mice. In addition to transforming Gram-negative bacterial lipopolysaccharide from stimulus to inhibitor, its most studied activity, AOAH can inactivate these important danger-associated molecular pattern molecules and reduce tissue inflammation and injury.
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Lesión Pulmonar Aguda/inducido químicamente , Hidrolasas de Éster Carboxílico/farmacología , Fosfolípidos/metabolismo , Lesión Pulmonar Aguda/patología , Animales , Células Cultivadas , Ácido Clorhídrico/toxicidad , Inflamasomas/metabolismo , Inflamación , Lipopolisacáridos/toxicidad , Macrófagos , Ratones , Ratones Transgénicos , Oxidación-ReducciónRESUMEN
Although microbe-associated molecular pattern (MAMP) molecules can promote cholesterol accumulation in macrophages, the existence of a host-derived MAMP inactivation mechanism that prevents foam cell formation has not been described. Here, we tested the ability of acyloxyacyl hydrolase (AOAH), the host lipase that inactivates gram-negative bacterial lipopolysaccharides (LPSs), to prevent foam cell formation in mice. Following exposure to small intraperitoneal dose(s) of LPSs, Aoah -/- macrophages produced more low-density lipoprotein receptor and less apolipoprotein E and accumulated more cholesterol than did Aoah +/+ macrophages. The Aoah -/- macrophages also maintained several pro-inflammatory features. Using a perivascular collar placement model, we found that Aoah -/- mice developed more carotid artery foam cells than did Aoah +/+ mice after they had been fed a high fat, high cholesterol diet, and received small doses of LPSs. This is the first demonstration that an enzyme that inactivates a stimulatory MAMP in vivo can reduce cholesterol accumulation and inflammation in arterial macrophages.
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Although organ hypofunction and immunosuppression are life-threatening features of severe sepsis, the hypofunctioning organs and immune cells usually regain normal functionality if patients survive. Because tissue interstitial fluid can become acidic during the septic response, we tested the hypothesis that low extracellular pH (pHe) can induce reversible metabolic and functional changes in peritoneal macrophages from C57BL/6J mice. When compared with macrophages cultured at normal pHe, macrophages living in an acidic medium used less glucose and exogenous fatty acid to produce ATP. Lactate, glutamine, and de novo-synthesized fatty acids supported ATP production by mitochondria that gained greater mass, maximal oxygen consumption rate, and spare respiratory capacity. The cells transitioned to an M2-like state, with altered immune responses to LPS and slightly decreased phagocytic ability, yet they regained basal energy production, normal mitochondrial function, and proinflammatory responsiveness when neutral pHe was restored. Low pHe induces changes that support macrophage survival while rendering the cells less proinflammatory (more "tolerant") and less able to phagocytose bacteria. Macrophage responses to low interstitial pH may contribute to the reversible organ hypofunction and immunoparalysis noted in many patients with sepsis.
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Espacio Extracelular/inmunología , Inmunidad Innata/inmunología , Macrófagos Peritoneales/inmunología , Sepsis/inmunología , Animales , Células Cultivadas , Concentración de Iones de Hidrógeno , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: In the home care industry, the assignment and tracking of care services are controlled by care centers that are centralized in nature and prone to inefficient information transmission. A lack of trust among the involved parties, information opaqueness, and large manual manipulation result in lower process efficiency. OBJECTIVE: This study aimed to explore and demonstrate the application of blockchain and smart contract technologies to innovate/renovate home care services for harvesting the desired blockchain benefits of process transparency, traceability, and interoperability. METHODS: An object-oriented analysis/design combined with a unified modeling language tool was used to construct the architecture of the proposed home care service system. System feasibility was evaluated via an implementation test, and a questionnaire survey was performed to collect opinions from home care service respondents knowledgeable about blockchain and smart contracts. RESULTS: According to the comparative analysis results, the proposed design outperformed the existing system in terms of traceability, system efficiency, and process automation. Moreover, for the questionnaire survey, the quantitative analysis results showed that the proposed blockchain-based system had significantly (P<.001) higher mean scores (when compared with the existing system) in terms of important factors, including timeliness, workflow efficiency, automatic notifications, insurance functionality, and auditable traceability. In summary, blockchain-based home care service participants will be able to enjoy improved efficiency, better transparency, and higher levels of process automation. CONCLUSIONS: Blockchain and smart contracts can provide valuable benefits to the home care service industry via distributed data management and process automation. The proposed system enhances user experiences by mitigating human intervention and improving service interoperability, transparency/traceability, and real-time response to home care service events. Efforts in exploring and integrating blockchain-based home care services with emerging technologies, such as the internet of things and artificial intelligence, are expected to provide further benefits and therefore are subject to future research.
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Animals can sense the presence of microbes in their tissues and mobilize their own defenses by recognizing and responding to conserved microbial structures (often called microbe-associated molecular patterns (MAMPs)). Successful host defenses may kill the invaders, yet the host animal may fail to restore homeostasis if the stimulatory microbial structures are not silenced. Although mice have many mechanisms for limiting their responses to lipopolysaccharide (LPS), a major Gram-negative bacterial MAMP, a highly conserved host lipase is required to extinguish LPS sensing in tissues and restore homeostasis. We review recent progress in understanding how this enzyme, acyloxyacyl hydrolase (AOAH), transforms LPS from stimulus to inhibitor, reduces tissue injury and death from infection, prevents prolonged post-infection immunosuppression, and keeps stimulatory LPS from entering the bloodstream. We also discuss how AOAH may increase sensitivity to pulmonary allergens. Better appreciation of how host enzymes modify LPS and other MAMPs may help prevent tissue injury and hasten recovery from infection.
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Hidrolasas de Éster Carboxílico/metabolismo , Bacterias Gramnegativas/metabolismo , Lipopolisacáridos/metabolismo , Animales , Hidrolasas de Éster Carboxílico/química , Hidrolasas de Éster Carboxílico/genética , Humanos , Pulmón/inmunología , Pulmón/metabolismo , Antígeno 96 de los Linfocitos/química , Antígeno 96 de los Linfocitos/metabolismo , Neutrófilos/metabolismo , Receptor Toll-Like 4/química , Receptor Toll-Like 4/metabolismoRESUMEN
Macrophages are the first-line host defense that the invading Mycobacterium tuberculosis (Mtb) encounters. It has been recently reported that host aerobic glycolysis was elevated post the infection by a couple of virulent mycobacterial species. However, whether this metabolic transition is required for host defense against intracellular pathogens and the underlying mechanisms remain to be further investigated. A pathogenic mycobacterial species, M. marinum, is genetically close to Mtb and was utilized in this study. Through analyzing cellular carbon metabolism of RAW 264.7 (a murine macrophage-like cell line) post M. marinum infection, a strong elevation of glycolysis was observed. Next, three glycolysis inhibitors were examined for their ability to inhibit mycobacterial proliferation inside RAW264.7 macrophages. Among them, a glucose analog, 2-deoxyglucose (2-DG) displayed a protective role against mycobacterial infection. Treatment with 2-DG at concentrations of 0.5 or 1 mM significantly induced autophagy and decreased the phagocytosis of M. marinum by macrophages. Moreover, 2-DG pre-treatment exerted a significantly protective effect on zebrafish larvae by limiting the proliferation of M. marinum, and such effect was correlated to tumor necrosis factor alpha (TNF-α) as the 2-DG pre-treatment increased the expression of TNF-α in both mouse peritoneal macrophages and zebrafish. On the contrary, the 2-DG treatment post infection did not restrain proliferation of M. marinum in WT zebrafish, and even accelerated bacterial replication in TNF-α-/- zebrafish. Together, modulation of glycolysis prior to infection boosts host immunity against M. marinum infection, indicating a potential intervention strategy to control mycobacterial infection.
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Enfermedades de los Peces/metabolismo , Glucólisis , Infecciones por Mycobacterium no Tuberculosas/veterinaria , Mycobacterium marinum/fisiología , Pez Cebra , Aerobiosis , Animales , Enfermedades de los Peces/microbiología , Ratones , Infecciones por Mycobacterium no Tuberculosas/metabolismo , Infecciones por Mycobacterium no Tuberculosas/microbiología , Células RAW 264.7RESUMEN
Dendritic cells (DCs), as professional antigenpresenting cells are essential for the initial activation of adaptive antitumor immunity. CD1d is considered to present phospholipid and glycosphingolipid antigens to NKT cells. However, it is currently unknown whether CD1d expression on DCs is capable of enhancing antitumor immunity, particularly Tcell related immunity. We observed that CD1d was predominantly expressed on DCs in 3LL tumorbearing mice, whilst a deficiency of CD1d promoted tumor growth. Notably, CD1d expression on DCs was not only required for presenting antigen to NKT cells, but also markedly promoted CD4+T and CD8+T cell activation, particularly cytotoxic T cells. All the T cells (NKT, CD4+T and CD8+T cells) upregulated CD69, CD107a and IFNγ after the adoptive transfer of CD1dpositive DCs (CD1d+DCs) and tumor growth was suppressed. With regard to the mechanism, we revealed that CD1d+DCs were concomitant with a higher expression of costimulatory molecules (CD40, CD80 and CD86) and MHCI/II, which are essential for DCs to present antigens to T cells. Consistently, CD1d+DCs displayed stronger activationassociatedERK1/2 and NFκB signals; whereas JAK2STAT3/6 signaling was required for maintaining a high level of CD1d on DCs. In lung cancer patients, the antitumor activities of all the T cells were enhanced with the increase of CD1d+DCs. Analysis of TCGA data revealed that high levels of CD1d indicated better outcomes for patients. Collectively, CD1d enhanced DCbased antitumor immunity, not only by targeting NKT, but also by activating CD4+T and CD8+T cells. CD1d+DCs may be superior to the bulk population of DCs in cancer immunotherapy.
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Antígenos CD1d/metabolismo , Células Dendríticas/inmunología , Neoplasias Pulmonares/inmunología , Traslado Adoptivo , Adulto , Anciano , Animales , Antígenos CD1d/genética , Antígenos CD1d/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Pulmón/patología , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Células T Asesinas Naturales/inmunología , Análisis de Supervivencia , Carga Tumoral/inmunologíaRESUMEN
Gliomas, the most common primary neoplasms in the brain, are notorious for their ability to evade the immune response. Despite microglial infiltration in gliomas, expression of MHC class II molecules in those microglia is compromised. Here, we report that Toll-like receptor 2 (TLR2) activation downregulated expression of MHC class II molecules in microglia in an orthotopic murine glioma model. TLR2-induced microglial impairment hindered the proliferation and activation of CD4+ T cells, which facilitated glioma immune evasion. TLR2-induced downregulation of MHC class II molecules was caused by suppression of the master regulator of MHC class II molecule transcription, Ciita TLR2 activation triggered downstream MAPK/ERK1/2 signaling and loss of histone H3 acetylation at Ciita promoters, which in turn inhibited Ciita expression. In glioblastoma tissues, various endogenous TLR2 ligands, including the heat shock proteins that are endogenous TLR2 ligands, were upregulated, a response that correlated with CIITA inhibition. Thus, TLR2 promotes glioma immune-system evasion. These results advance our understanding of microglia as antigen-presenting cells in the context of glioma. In the glioma tumor microenvironment, TLR2 activation of microglia induces downregulation of microglial MHC class II expression. Impaired MHC class II expression limits T-cell-dependent antitumor immunity. Cancer Immunol Res; 6(10); 1220-33. ©2018 AACR.
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Neoplasias Encefálicas/inmunología , Glioma/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Microglía/inmunología , Receptor Toll-Like 2/inmunología , Animales , Células Presentadoras de Antígenos/inmunología , Línea Celular , Regulación hacia Abajo , Evasión Inmune , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas Nucleares/inmunología , Transactivadores/inmunologíaRESUMEN
Allergic asthma is a chronic inflammatory disease primarily mediated by Th2 immune mechanisms. Numerous studies have suggested that early life exposure to lipopolysaccharide (LPS) is negatively associated with allergic asthma. One proposed mechanism invokes desensitization of lung epithelial cells by LPS. We report here that acyloxyacyl hydrolase (AOAH), a host lipase that degrades and inactivates LPS, renders mice more susceptible to house dust mite (HDM)-induced allergic asthma. Lung epithelial cells from Aoah-/- mice are refractory to HDM stimulation, decreasing dendritic cell activation and Th2 responses. Antibiotic treatment that diminished commensal LPS-producing bacteria normalized Aoah-/- responses to HDM, while giving LPS intrarectally ameliorated asthma. Aoah-/- mouse feces, plasma, and lungs contained more bioactive LPS than did those of Aoah+/+ mice. By inactivating commensal LPS, AOAH thus prevents desensitization of lung epithelial cells. An enzyme that prevents severe lung inflammation/injury in Gram-negative bacterial pneumonia has the seemingly paradoxical effect of predisposing to a Th2-mediated airway disease.
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Asma/inmunología , Hidrolasas de Éster Carboxílico/inmunología , Células Dendríticas/inmunología , Células Epiteliales/inmunología , Lipasa/inmunología , Lipopolisacáridos/toxicidad , Pulmón/inmunología , Animales , Asma/genética , Asma/patología , Hidrolasas de Éster Carboxílico/genética , Células Dendríticas/patología , Modelos Animales de Enfermedad , Células Epiteliales/patología , Lipasa/genética , Lipopolisacáridos/inmunología , Pulmón/patología , Ratones , Ratones Noqueados , Células Th2/inmunología , Células Th2/patologíaRESUMEN
BACKGROUND: Immune activation and suppression in patients with major depressive disorders (MDD) have been both reported in different studies. We assume that these findings may indicate innate immunological tolerance in MDD, with subclinical elevated level of proinflammatory cytokines and the decrease in innate immune response while encountering pathogens. METHODS: Peripheral monocytes of 50 untreated patients with MDD and 40 healthy controls were isolated and cultured, with or without 10â¯ng/ml lipopolysacchride (LPS) for 6â¯h (6â¯h, LPS+/-), and with LPS for 18â¯h (18, LPS+). The cell culture supernatants were collected to measure concentrations of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1 beta (IL-1ß). RESULTS: The baseline concentrations of IL-6 and IL-1ß (6â¯h, LPS-) were significantly higher in the MDD group than those in the control group. There was no significant difference of TNF-α between the two groups. The fold changes of LPS-induced secretion of IL-6 and TNF-α from monocytes cultured for 6 and 18â¯h were all lower in the patient groups, and that was true for IL-1ß as monocytes cultured for 18â¯h. LIMITATIONS: Given the gap between the results of in vitro experiments and the actual response that happens in vivo when the immune system encounters pathogens from the external world, future research should include in vivo methods to test the results of the current study. CONCLUSIONS: Patients with MDD may have subclinical inflammation during a depressive episode, and the reduced response to LPS in monocytes indicates innate immunological tolerance.
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Citocinas/metabolismo , Trastorno Depresivo Mayor/metabolismo , Monocitos/metabolismo , Adolescente , Adulto , Células Cultivadas , Femenino , Voluntarios Sanos , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Lipopolisacáridos , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
Pulmonary infection is the most common risk factor for acute lung injury (ALI). Innate immune responses induced by Microbe-Associated Molecular Pattern (MAMP) molecules are essential for lung defense but can lead to tissue injury. Little is known about how MAMP molecules are degraded in the lung or how MAMP degradation/inactivation helps prevent or ameliorate the harmful inflammation that produces ALI. Acyloxyacyl hydrolase (AOAH) is a host lipase that inactivates Gram-negative bacterial endotoxin (lipopolysaccharide, or LPS). We report here that alveolar macrophages increase AOAH expression upon exposure to LPS and that Aoah+/+ mice recover more rapidly than do Aoah-/- mice from ALI induced by nasally instilled LPS or Klebsiella pneumoniae. Aoah-/- mouse lungs had more prolonged leukocyte infiltration, greater pro- and anti-inflammatory cytokine expression, and longer-lasting alveolar barrier damage. We also describe evidence that the persistently bioactive LPS in Aoah-/- alveoli can stimulate alveolar macrophages directly and epithelial cells indirectly to produce chemoattractants that recruit neutrophils to the lung and may prevent their clearance. Distinct from the prolonged tolerance observed in LPS-exposed Aoah-/- peritoneal macrophages, alveolar macrophages that lacked AOAH maintained or increased their responses to bioactive LPS and sustained inflammation. Inactivation of LPS by AOAH is a previously unappreciated mechanism for promoting resolution of pulmonary inflammation/injury induced by Gram-negative bacterial infection.
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Lesión Pulmonar Aguda/inmunología , Hidrolasas de Éster Carboxílico/inmunología , Lipopolisacáridos/efectos adversos , Lesión Pulmonar Aguda/enzimología , Lesión Pulmonar Aguda/etiología , Animales , Hidrolasas de Éster Carboxílico/genética , Humanos , Infecciones por Klebsiella/enzimología , Infecciones por Klebsiella/genética , Infecciones por Klebsiella/inmunología , Klebsiella pneumoniae/inmunología , Lipopolisacáridos/inmunología , Pulmón/inmunología , Pulmón/microbiología , Macrófagos Peritoneales/enzimología , Macrófagos Peritoneales/inmunología , Ratones , Ratones NoqueadosRESUMEN
Gram-negative bacterial LPS induce murine B-cell activation and innate (polyclonal) Ab production. Mouse B cells express the LPS signaling receptor (TLR4), yet how LPS activates B-cell responses in vivo is not known. Can LPS directly stimulate B cells to induce innate Ab production? Is activation of non-B cells also required? To address these questions, we transfused LPS-responsive (Tlr4(+/+)) or non-responsive (Tlr4(-/-)) B cells into LPS-responsive or non-responsive mice. Increased expression of the early activation markers CD69 and CD86 could be induced on transfused Tlr4(-/-) B cells by injecting LPS subcutaneously into Tlr4(+/+) mice, demonstrating indirect activation of B cells by TLR4-responsive non-B cells in vivo, but the Tlr4(-) (/) (-) B cells did not increase serum IgM levels. In contrast, when Tlr4(-/-) recipients were transfused with Tlr4(+/+) B cells, LPS induced large amounts of serum IgM and LPS could also enhance specific Ab production to a protein that was co-injected with it (adjuvant response). Thus, LPS-exposed non-B cells mediated increased surface expression of early B-cell activation markers, but this response did not predict innate Ab responses or LPS adjuvanticity in vivo Direct stimulation of B cells by LPS via TLR4 was necessary and sufficient to induce B cells to produce Ab in vivo.
Asunto(s)
Linfocitos B/inmunología , Inmunoglobulina M/metabolismo , Receptor Toll-Like 4/metabolismo , Animales , Formación de Anticuerpos , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Antígeno B7-2/metabolismo , Células Cultivadas , Inmunidad Innata , Inmunoglobulina M/genética , Lectinas Tipo C/metabolismo , Lipopolisacáridos/inmunología , Activación de Linfocitos , Transfusión de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor Toll-Like 4/genéticaRESUMEN
OBJECTIVE: To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. METHODS: The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cm away from the wall, the hitting tool with 5 mL fresh chicken blood made the cast-off bloodstain from top to bottom. Then the holistic distribution characteristics (length, width and density) of cast-off bloodstain and morphology characteristics (length, width and contact angle) of first single cast-off bloodstain were analyzed. RESULTS: The distribution length of cast-off bloodstain formed by dirk was minimum (P < 0.05). The distribution width of cast-off bloodstain formed by kitchen knife was minimum (P < 0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P < 0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P < 0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P < 0.05). CONCLUSION: The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.
Asunto(s)
Manchas de Sangre , Simulación por Computador , Balística Forense/métodos , Crimen , Medicina Legal/métodos , HumanosRESUMEN
Lipid-laden macrophages contribute to pathologies as diverse as atherosclerosis and tuberculosis. Three common stimuli are known to promote macrophage lipid storage: low tissue oxygen tension (pO2), low extracellular pH (pHo), and exposure to agonists such as bacterial LPS. Noting that cells responding to low pO2 or agonistic bacterial molecules often decrease pHo by secreting lactic and other carboxylic acids, we studied how pHo influences the stimulation of triacylglycerol (TAG) storage by low pO2 and LPS. We found that TAG retention after incubation for 48-72 h was inversely related to pHo when primary macrophages were cultured in 21% oxygen, 4% oxygen, or with LPS at either oxygen concentration. Maintaining pHo at ~7.4 was sufficient to prevent the increase in prolonged TAG storage induced by either low pO2 or LPS. The strong influence of pHo on TAG retention may explain why lipid-laden macrophages are found in some tissue environments and not in others. It is also possible that other long-term cellular changes currently attributed to low pO2 or bacterial agonists may be promoted, at least in part, by the decrease in pHo that these stimuli induce.