RESUMO
BACKGROUND/AIMS: Sphingosine, a sphingoid long chain base, is a natural lipid with antimicrobial properties. Recent animal studies have shown that preventive sphingosine inhalation can rescue susceptible mice, such as cystic fibrosis-, burn injured- or aged mice from bacterial pulmonary infection. While preventing lung infections in susceptible patients has obvious clinical merit, treatment strategies for an established infection are also direly needed, particularly in the times of rising antibiotic resistance. Here, we tested the potential of sphingosine in treating an established pulmonary infection. METHODS: We used a cecal ligation and puncture (CLP) model in male CF-1 mice and a Pseudomonas aeruginosa strain that was isolated from a septic patient (P. aeruginosa 762). We determined susceptibility to intranasal infection and ascertained when the pulmonary infection was established by continuous core body temperature monitoring. We quantified sphingosine levels in the tracheal epithelium by immunohistochemistry and studied the effects on sphingosine on bacterial membrane permeabilization and intracellular acidification using fluorescent probes. RESULTS: We firstdetermined that septic mice are highly susceptible to P. aeruginosa infection 2 days after indu-cing sepsis. Additionally, at this time, sphingosine levels in the tracheal epithelium are significantly reduced as compared to levels in healthy mice. Secondly, upon intranasal Pseudomonasinoculation, we ascertained that pulmonary infection was established as early as 2.5 h after inoculation as evidenced by a significant drop in core body temperature. Using these times of infection susceptibility and detection (2 days post CLP, 2.5h after inoculation) we treated with inhaled sphingosine and observed pulmonary bacterial loads reduced to levels found in infected healthy mice after inoculation and decreased infection-associated mortality. Further, our data demonstrate that sphingosine induces outer membrane permeabilization, disrupting the membrane potential and leading to intracellular acidification of the bacteria. CONCLUSION: Sphingosine shows efficacy in treating P. aeruginosa lung infections not only prophylactically, but also therapeutically.
Assuntos
Fibrose Cística/tratamento farmacológico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Sepse/tratamento farmacológico , Esfingosina/administração & dosagem , Traqueia/efeitos dos fármacos , Administração por Inalação , Animais , Estado Terminal , Fibrose Cística/microbiologia , Fibrose Cística/patologia , Modelos Animais de Doenças , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Sepse/microbiologia , Sepse/patologia , Traqueia/microbiologia , Traqueia/patologiaRESUMO
BACKGROUND/AIMS: During sepsis, an unchecked pro-inflammatory response can be detrimental to the host. We investigated the potential protective effect of amitriptyline (AT). METHODS: We used two murine models of sepsis: Cecal ligation and puncture and endotoxemia following LPS challenge. Aural temperatures were taken and cytokines quantified by cytometric bead assay. Lung injury was determined histologically and by protein determination in bronchoalveolar lavage fluid. Cell accumulation in the peritoneum was analyzed by flow cytometry, as well as cytokine production and p38-phosphorylation. Neutrophil chemotaxis was evaluated using an in vitro transwell assay. RESULTS: Our findings demonstrate that AT-treated septic mice have improved survival and are protected from pulmonary edema. Treatment with AT significantly decreased serum levels of KC and monocyte chemoattractant protein-1, as well as the accumulation of neutrophils and monocytes in the peritoneum of septic mice. Peritoneal IL-10 levels in septic mice were increased upon AT treatment. Direct treatment of septic mice with IL-10 recapitulated the effects of AT. Endotoxemic mice also exhibited enhanced IL-10 production upon AT-administration and peritoneal macrophages were identified as the ATinfluenced producers of IL-10. Treatment of these cells with AT in vitro resulted in increased p38-phosphorylation and IL-10 generation, whereas ceramide and p38 inhibition had the opposite effect. CONCLUSION: Altogether, AT treatment improved survival, increased IL-10 levels, and mitigated a pro-inflammatory response during sepsis. We conclude that AT is a promising therapeutic to temper inflammation during septic shock.
Assuntos
Amitriptilina/uso terapêutico , Sepse/tratamento farmacológico , Amitriptilina/farmacologia , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Ceramidas/farmacologia , Quimiocina CCL2/análise , Citocinas/análise , Modelos Animais de Doenças , Inflamação , Interleucina-10/sangue , Lipopolissacarídeos/farmacologia , Pulmão/patologia , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Neutrófilos/citologia , Neutrófilos/imunologia , Fosforilação/efeitos dos fármacos , Sepse/metabolismo , Sepse/mortalidade , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
BACKGROUND: Deep vein thrombosis (DVT) remains a significant cause of morbidity after injury. Lower extremity duplex ultrasound screening (LEDUS) is designed to identify early, asymptomatic DVTs in moderate and high risk patients. We sought to describe when thrombus is detected and identify which trauma patients benefit from LEDUS. MATERIALS AND METHODS: A retrospective review was conducted on trauma patients who were moderate or high risk for venous thromboembolism based on risk assessment profile (RAP) scoring. Patients with RAP scores ≥5 underwent LEDUS on hospital Day 4 and then weekly. We defined moderate venous thromboembolism risk as an RAP score of 5-9 and high risk as an RAP score of ≥10. Demographics, injury characteristics, and chemoprophylaxis type and timing were analyzed. RESULTS: A total of 579 trauma patients underwent a total of 820 ultrasounds in 1 y. Eighty-eight acute DVTs were identified. There was only one progression of a below- to above-the-knee DVT. Patients with RAP scores ≥10 had significantly higher rates of DVTs compared with patients with lower RAP scores in addition to longer lengths of stay and time to DVT prophylaxis. Moderate- and high-risk patients had similar rates of pulmonary embolism. Two-thirds of all DVTs were diagnosed on the first screening examination. The rate of DVTs in patients with RAP scores 7-9 was 15.4% compared with 6.1% of those with RAP scores of 5-6. CONCLUSIONS: LEDUS allows for early identification of asymptomatic DVTs. Moderate-risk patients with RAP scores of ≥7 should be considered for LEDUS, given higher rates of DVT.
Assuntos
Trombose Venosa/diagnóstico por imagem , Ferimentos e Lesões/complicações , Adulto , Idoso , Feminino , Humanos , Extremidade Inferior/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Ultrassonografia Doppler Dupla , Tromboembolia Venosa/etiologia , Trombose Venosa/etiologiaRESUMO
BACKGROUND: The risk assessment profile (RAP) score has been used to determine patients who would most benefit from lower extremity duplex ultrasound screening (LEDUS). We hypothesized that revising our LEDUS protocol to perform screening ultrasound examinations in patients with an RAP ≥8 within 48 h of admission would reduce the number of LEDUS performed without changing outcomes. METHODS: A retrospective review was conducted on trauma patients admitted from July 1, 2014, to June 30, 2015, and July 1, 2016, to June 30, 2017. In 2014-2015, patients with an RAP score ≥5 underwent weekly LEDUS examinations starting on hospital day 4. In 2016-2017, the protocol was changed to start screening patients with an RAP score ≥8 by hospital day 2. Both protocols screened with weekly ultrasounds after the first examination. Demographic data, injury characteristics, LEDUS examination findings, chemoprophylaxis type, and venous thromboembolism incidence were collected. RESULTS: A total of 602 patients underwent LEDUS examination in 2014-2015, whereas only 412 underwent LEDUS in 2016-2017. No significant difference was seen in the number of patients diagnosed with deep vein thrombosis (DVT) or pulmonary embolism. DVTs were most often identified on the first LEDUS examination in both cohorts. Of patients diagnosed with a DVT on an LEDUS examination, a significantly higher RAP score (12 versus 10), and a shorter time to first duplex (1 versus 3 d), and DVT diagnosis (2 versus 4 d) were observed in the 2016-2017 cohort. In patients diagnosed with a pulmonary embolism, no significant differences were demonstrated between cohorts. CONCLUSIONS: Refinement of LEDUS protocols can decrease overutilization of hospital resources without compromising trauma patient outcomes.
Assuntos
Extremidade Inferior/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Ultrassonografia Doppler Dupla/normas , Procedimentos Desnecessários/normas , Trombose Venosa/diagnóstico por imagem , Ferimentos e Lesões/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos Clínicos , Feminino , Seguimentos , Humanos , Extremidade Inferior/irrigação sanguínea , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/etiologia , Estudos Retrospectivos , Medição de Risco , Ultrassonografia Doppler Dupla/tendências , Procedimentos Desnecessários/tendências , Trombose Venosa/complicaçõesRESUMO
BACKGROUND: Bacterial lung infection is a leading cause of death for those 65 y or older, often requiring intensive care unit admission and mechanical ventilation, which consumes considerable health care resources. Although administration of antibiotics is the standard of care for bacterial pneumonia, its overuse has led to the emergence of multidrug resistant organisms. Therefore, alternative strategies to help minimize the effects of bacterial pneumonia in the elderly are necessary. As studies have shown that sphingosine (SPH) has inherent bacterial killing properties, our goal was to assess whether it could act as a prophylactic treatment to protect aged mice from pulmonary infection by Pseudomonas aeruginosa. METHODS: Aged (51 wk) and young (8 wk) C57Bl/6 mice were used in this study. Pulmonary SPH levels were determined by histology. SPH content of microparticles was quantified using a SPH kinase assay. Pneumonia was induced by intranasally treating mice with 106 Colony Forming Unit (CFU) P aeruginosa. Microparticles were isolated from young mice, whereas some were further incubated with SPH. RESULTS: We observed that SPH levels are reduced in the bronchial epithelial cells as well as the bronchoalveolar lavage microparticles isolated from aged mice, which correlates with a susceptibility to infection. We demonstrate that SPH or microparticle treatment can protect aged mice from pulmonary P aeruginosa infection. Finally, we observed that enriching microparticles with SPH before treatment eliminated the bacterial load in P aeruginosa-infected aged mice. CONCLUSIONS: These data suggest that prophylactic treatment with SPH could reduce lung bacterial infections for the at-risk elderly population.
Assuntos
Pneumonia Bacteriana/prevenção & controle , Esfingosina/administração & dosagem , Fatores Etários , Animais , Líquido da Lavagem Broncoalveolar/química , Micropartículas Derivadas de Células/química , Avaliação Pré-Clínica de Medicamentos , Masculino , Camundongos Endogâmicos C57BL , Pneumonia Bacteriana/microbiologia , Pseudomonas aeruginosa , Mucosa Respiratória/metabolismo , Esfingosina/análise , Esfingosina/metabolismoRESUMO
Critically ill patients that survive sepsis can develop a Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS), which often leads to extended recovery periods and multiple complications. Here, we utilized a cecal ligation and puncture (CLP) method in mice with the goal of creating a model that concurrently displays all the characteristics of PICS. We observed that, after eight days, mice that survive the CLP develop persistent inflammation with significant myelopoiesis in the bone marrow and spleen. These mice also demonstrate ongoing immune suppression, as evidenced by the decreased total and naïve splenic CD4 and CD8 T cells with a concomitant increase in immature myeloid cells. The mice further display significant weight loss and decreased muscle mass, indicating a state of ongoing catabolism. When PICS mice are challenged with intranasal Pseudomonas aeruginosa, mortality is significantly elevated compared to sham mice. This mortality difference is associated with increased bacterial loads in the lung, as well as impaired neutrophil migration and neutrophil dysfunction in the PICS mice. Altogether, we have created a sepsis model that concurrently exhibits PICS characteristics. We postulate that this will help determine the mechanisms underlying PICS and identify potential therapeutic targets to improve outcomes for this patient population.
Assuntos
Tolerância Imunológica , Inflamação/etiologia , Sepse/complicações , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Estado Terminal , Modelos Animais de Doenças , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Infecções por Pseudomonas/complicações , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/fisiologia , Sepse/imunologia , Sepse/metabolismo , Sepse/patologiaRESUMO
DNA damage from (+/-)-anti-benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) at a hotspot TP53 gene sequence was electrochemically detected. BPDE was exposed to gold electrode immobilized double-stranded DNA oligomers followed by voltammetric measurements in the presence of redox-active C(12)H(25)V(2+)C(6)H(12)V(2+)C(12)H(25) (V(2+) = 4,4'-bipyridyl or viologen, C12-viologen). Square wave voltammograms from BPDE-exposed DNA-modified electrodes showed the emergence of a C12-viologen-DNA complex at -0.37 V versus Ag/AgCl. The peak current intensity of this redox wave was dependent on both BPDE concentration and exposure time. Controls with alternate xenobiotics and DNA sequences showed this redox wave to be primarily due to BPDE damage at the wild-type DNA sequence. The detection limit was determined to be approximately 170 nM BPDE. Mass spectrometry and UV thermal melting experiments provided insight into the BPDE reaction and mirrored the sensor results. This report demonstrates that an electrochemical hybridization sensor can be used to detect sequence-related xenobiotic DNA damage.
Assuntos
7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/toxicidade , Carcinógenos/toxicidade , Códon/genética , Dano ao DNA/genética , Eletroquímica/métodos , Oligodesoxirribonucleotídeos/genética , Proteína Supressora de Tumor p53/genética , Sequência de Bases , Genômica , Cinética , Espectrometria de Massas , Modelos Moleculares , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Temperatura de TransiçãoRESUMO
BACKGROUND: Traumatic brain injury (TBI) can result in an acute coagulopathy including platelet dysfunction that can contribute to ongoing intracranial hemorrhage. Previous studies have shown adenosine diphosphate (ADP)-induced platelet aggregation to be reduced after TBI. In addition, circulating microvesicles (MVs) are increased following TBI and have been shown to play a role in post-TBI coagulopathy and platelet function. We hypothesized that post-TBI MVs would affect platelet aggregation in a murine head injury model. METHODS: Moderate TBI was performed using a weight-drop method in male C57BL6 mice. Whole blood, plasma, MVs, and MV-poor plasma were isolated from blood collected 10 minutes following TBI and were mixed separately with whole blood from uninjured mice. Platelet aggregation was measured with Multiplate impedance platelet aggregometry in response to ADP. The ADP P2Y12 receptor inhibitor, R-138727, was incubated with plasma and MVs from TBI mice, and platelet inhibition was again measured. RESULTS: Whole blood taken from 10-minute post-TBI mice demonstrated diminished ADP-induced platelet aggregation compared with sham mice. When mixed with normal donor blood, post-TBI plasma and MVs induced diminished ADP-induced platelet aggregation compared with sham plasma and sham MVs. By contrast, the addition of post-TBI MV-poor plasma to normal blood did not change ADP-induced platelet aggregation. The observed dysfunction in post-TBI ADP platelet aggregation was prevented by the pretreatment of post-TBI plasma with R-138727. Treatment of post-TBI MVs with R-138727 resulted in similar findings of improved ADP-induced platelet aggregation compared with nontreated post-TBI MVs. CONCLUSION: Adenosine diphosphate-induced platelet aggregation is inhibited acutely following TBI in a murine model. This platelet inhibition is reproduced in normal blood by the introduction of post-TBI plasma and MVs. Furthermore, observed platelet dysfunction is prevented when post-TBI plasma and MVs are treated with an inhibitor of the P2Y12 ADP receptor. Clinically observed post-TBI platelet dysfunction may therefore be partially explained by the presence of the ADP P2Y12 receptor within post-TBI MVs. LEVEL OF EVIDENCE: Level III.
Assuntos
Transtornos Plaquetários/fisiopatologia , Lesões Encefálicas Traumáticas/fisiopatologia , Micropartículas Derivadas de Células/fisiologia , Receptores Purinérgicos P2/fisiologia , Animais , Micropartículas Derivadas de Células/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperazinas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Receptores Purinérgicos P2/efeitos dos fármacosRESUMO
Burn patients have a high risk of sepsis-related mortality even after surviving the initial injury. Immunosuppression increases the risk of sepsis after burn injury, as does the disruption of the intestinal epithelial barrier, which allows the translocation of bacteria and bacterial products into the circulation. The integrity of the intestinal epithelial barrier is largely maintained by the intestinal microbiota. Burn injury has been reported to result in significant changes in the intestinal microbiome composition. In this mouse study, we confirm these taxonomic differences in a full-thickness scald injury model using CF-1 mice. For the first time, we also address alterations in functional gene expression of the intestinal microbiota after burn injury to assess the microbiome's physiological capabilities for overgrowth and pathogenic invasion: 38 pathways were differentially abundant between the sham and burn injury mice, including bacterial invasion of epithelial cells and gap- and adherens junction pathways.
Assuntos
Queimaduras/microbiologia , Código de Barras de DNA Taxonômico/métodos , Disbiose/microbiologia , Microbioma Gastrointestinal/genética , Mucosa Intestinal/microbiologia , RNA Ribossômico 16S/genética , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Animais , Apicomplexa/classificação , Apicomplexa/genética , Apicomplexa/isolamento & purificação , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Queimaduras/genética , Queimaduras/patologia , Modelos Animais de Doenças , Disbiose/genética , Disbiose/patologia , Fezes/microbiologia , Firmicutes/classificação , Firmicutes/genética , Firmicutes/isolamento & purificação , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos/sangue , Fator Estimulador de Colônias de Granulócitos/genética , Interleucina-6/sangue , Interleucina-6/genética , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos , Permeabilidade , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Transdução de Sinais , Pele/patologia , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificaçãoRESUMO
BACKGROUND: Pregnancy-associated breast cancer (PABC) is the most common malignancy in pregnancy. However due to its infrequent occurrence, PABC continues to be poorly understood. METHODS: We performed a retrospective study using self-reported data from 1079 eligible women in a regional breast cancer registry. RESULTS: The PABC cases were more likely than non-PABCs to be younger than age 35 and have nodal involvement at diagnosis. Despite diagnosis at a young age, there was not an association between PABC and family history. For method of diagnosis, PABC was found on self-exam, while non-PABCs were found on mammography. CONCLUSION: In conclusion, PABC is rarely detected by mammography and diagnosis is highly dependent on detection during self-breast exam. Women who are or recently were pregnant should be encouraged to perform regular self-breast exams to report any changes for further evaluation. Patient and clinician education regarding risk and realities of PABC is essential.
Assuntos
Neoplasias da Mama/etiologia , Lactação , Complicações Neoplásicas na Gravidez/etiologia , Transtornos Puerperais/etiologia , Adulto , Neoplasias da Mama/diagnóstico , Autoexame de Mama , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Gravidez , Complicações Neoplásicas na Gravidez/diagnóstico , Transtornos Puerperais/diagnóstico , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , AutorrelatoRESUMO
Septic shock increases vascular permeability, leading to multiple organ failure including cardiac dysfunction, a major contributor to septic death. Podosome, an actin-based dynamic membrane structure, plays critical roles in extracellular matrix degradation and angiogenesis. However, whether podosome contributes to endothelial barrier dysfunction during septic shock remains unknown. In this study, we found that the endothelial hyperpermeability, stimulated by phorbol 12-myristate 13-acetate and thrombin, was accompanied by increased formation of podosome clusters at the cell periphery, indicating a positive correlation between podosome clusters and endothelial leakage. Interestingly, we observed that circulating exosomes collected from septic mice were able to stimulate podosome cluster formation in cardiac endothelial cells, together with increased permeability in vitro/in vivo and cardiac dysfunction. Mechanistically, we identified that septic exosomes contained higher levels of reactive oxygen species (ROS) than normal ones, which were effectively transported to endothelial cells (ECs). Depletion of ROS in septic exosomes significantly reduced their capacity for promoting podosome cluster formation and thereby dampened vascular leakage. Finally, we elucidated that podosome cluster-induced endothelial hyperpermeability was associated with fragmentation/depletion of zonula occludens-1 (ZO-1) at the cell periphery. Our results demonstrate that septic exosomes were enriched with high amounts of ROS, which can be transported to ECs, leading to the generation of podosome clusters in target ECs and thereby, causing ZO-1 relocation, vascular leakage, and cardiac dysfunction.
Assuntos
Exossomos/metabolismo , Podossomos/metabolismo , Sepse/metabolismo , Animais , Western Blotting , Permeabilidade Capilar/fisiologia , Células Endoteliais/metabolismo , L-Lactato Desidrogenase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Espécies Reativas de Oxigênio/metabolismo , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
Blood product transfusion may exacerbate the initial immunosuppressive response of sepsis. Nurses and other patient care providers must be diligent in recognizing and managing a worsening immune status, using flow cytometry to monitor patients' immune status. This type of monitoring may be instrumental in reducing morbidity and mortality in persons with sepsis. This article discusses the recent literature on the associated inflammatory responses that occur with blood transfusion and provides an analysis of alterations in key inflammatory pathways in response to transfusion in a sepsis population.
Assuntos
Terapia de Imunossupressão/efeitos adversos , Inflamação , Sepse/terapia , Reação Transfusional , Enfermagem de Cuidados Críticos , Citocinas/metabolismo , Humanos , Imunomodulação , Sepse/mortalidadeRESUMO
BACKGROUND: Pseudomonas aeruginosa is a major cause of morbidity and mortality among burn patients, despite antibiotic therapy. There is a need to identify innate immune defenses that prevent P aeruginosa infection in injured adults in an effort to find therapeutic alternatives to antibiotics. Here, we tested our hypothesis that microvesicles (MVs) in bronchoalveolar (BAL) fluid have a role in the immunity of the lung in response to pathogens. STUDY DESIGN: Microvesicles were isolated from murine BAL fluid, quantified using Nanoparticle Tracking Analysis, and injected into burn-injured mice before P aeruginosa infection. Survival was assessed and BAL bacterial loads enumerated. Neutrophil number and interleukin 6 activity were determined. Lungs were harvested and sphingosine (SPH) content analyzed via immunohistochemistry. Antimicrobial effects of MVs and SPH-enriched MVs were assessed in an in vitro assay. RESULTS: Burn-injured mice have reduced BAL MV number and SPH content compared with sham. When BAL MVs from healthy mice are administered to injured mice, survival and bacterial clearance are improved robustly. We also observed that intranasal administration of MVs restores SPH levels after burn injury, MVs kill bacteria directly, and this bacterial killing is increased when the MVs are supplemented with SPH. CONCLUSIONS: Using a preclinical model, BAL MVs are reduced after scald injury and BAL MV restoration to injured mice improves survival and bacterial clearance. The antimicrobial mechanisms leading to improved survival include the quantity and SPH content of BAL MVs.
Assuntos
Lavagem Broncoalveolar , Queimaduras/complicações , Queimaduras/terapia , Micropartículas Derivadas de Células , Pneumonia Bacteriana/prevenção & controle , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Pneumonia Bacteriana/microbiologiaRESUMO
Prolonged alcohol consumption in humans followed by abstinence precipitates a withdrawal syndrome consisting of anxiety, agitation and in severe cases, seizures. Withdrawal is relieved by a low dose of alcohol, a negative reinforcement that contributes to alcohol dependency. This phenomenon of 'withdrawal relief' provides evidence of an ethanol-induced adaptation which resets the balance of signalling in neural circuits. We have used this as a criterion to distinguish between direct and indirect ethanol-induced adaptive behavioural responses in C. elegans with the goal of investigating the genetic basis of ethanol-induced neural plasticity. The paradigm employs a 'food race assay' which tests sensorimotor performance of animals acutely and chronically treated with ethanol. We describe a multifaceted C. elegans 'withdrawal syndrome'. One feature, decrease reversal frequency is not relieved by a low dose of ethanol and most likely results from an indirect adaptation to ethanol caused by inhibition of feeding and a food-deprived behavioural state. However another aspect, an aberrant behaviour consisting of spontaneous deep body bends, did show withdrawal relief and therefore we suggest this is the expression of ethanol-induced plasticity. The potassium channel, slo-1, which is a candidate ethanol effector in C. elegans, is not required for the responses described here. However a mutant deficient in neuropeptides, egl-3, is resistant to withdrawal (although it still exhibits acute responses to ethanol). This dependence on neuropeptides does not involve the NPY-like receptor npr-1, previously implicated in C. elegans ethanol withdrawal. Therefore other neuropeptide pathways mediate this effect. These data resonate with mammalian studies which report involvement of a number of neuropeptides in chronic responses to alcohol including corticotrophin-releasing-factor (CRF), opioids, tachykinins as well as NPY. This suggests an evolutionarily conserved role for neuropeptides in ethanol-induced plasticity and opens the way for a genetic analysis of the effects of alcohol on a simple model system.