RESUMO
Hypoxemia is a defining feature of acute respiratory distress syndrome (ARDS), an often-fatal complication of pulmonary or systemic inflammation, yet the resulting tissue hypoxia, and its impact on immune responses, is often neglected. In the present study, we have shown that ARDS patients were hypoxemic and monocytopenic within the first 48 h of ventilation. Monocytopenia was also observed in mouse models of hypoxic acute lung injury, in which hypoxemia drove the suppression of type I interferon signaling in the bone marrow. This impaired monopoiesis resulted in reduced accumulation of monocyte-derived macrophages and enhanced neutrophil-mediated inflammation in the lung. Administration of colony-stimulating factor 1 in mice with hypoxic lung injury rescued the monocytopenia, altered the phenotype of circulating monocytes, increased monocyte-derived macrophages in the lung and limited injury. Thus, tissue hypoxia altered the dynamics of the immune response to the detriment of the host and interventions to address the aberrant response offer new therapeutic strategies for ARDS.
Assuntos
Lesão Pulmonar , Síndrome do Desconforto Respiratório , Animais , Humanos , Hipóxia/etiologia , Inflamação/complicações , Pulmão , Lesão Pulmonar/complicações , CamundongosRESUMO
Liver regeneration is a complex process involving the crosstalk of multiple cell types, including hepatocytes, hepatic stellate cells, endothelial cells and inflammatory cells. The healthy liver is mitotically quiescent, but following toxic damage or resection the cells can rapidly enter the cell cycle to restore liver mass and function. During this process of regeneration, epithelial and non-parenchymal cells respond in a tightly coordinated fashion. Recent studies have described the interaction between inflammatory cells and a number of other cell types in the liver. In particular, macrophages can support biliary regeneration, contribute to fibrosis remodelling by repressing hepatic stellate cell activation and improve liver regeneration by scavenging dead or dying cells in situ. In this Review, we describe the mechanisms of tissue repair following damage, highlighting the close relationship between inflammation and liver regeneration, and discuss how recent findings can help design novel therapeutic approaches.
Assuntos
Cirrose Hepática/patologia , Cirrose Hepática/terapia , Regeneração Hepática/fisiologia , Transplante de Células , Células Epiteliais/citologia , Células Epiteliais/transplante , Células Estreladas do Fígado/metabolismo , Hepatócitos/citologia , Hepatócitos/patologia , Hepatócitos/transplante , Humanos , Inflamação , Macrófagos/citologia , Macrófagos/patologia , Macrófagos/transplante , Transdução de SinaisRESUMO
BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a cancer of the hepatic bile ducts that is rarely resectable and is associated with poor prognosis. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is known to signal via its receptor fibroblast growth factor-inducible 14 (Fn14) and induce cholangiocyte and myofibroblast proliferation in liver injury. We aimed to characterise its role in CCA. METHODS: The expression of the TWEAK ligand and Fn14 receptor was assessed immunohistochemically and by bulk RNA and single cell transcriptomics of human liver tissue. Spatiotemporal dynamics of pathway regulation were comprehensively analysed in rat and mouse models of thioacetamide (TAA)-mediated CCA. Flow cytometry, qPCR and proteomic analyses of CCA cell lines and conditioned medium experiments with primary macrophages were performed to evaluate the downstream functions of TWEAK/Fn14. In vivo pathway manipulation was assessed via TWEAK overexpression in NICD/AKT-induced CCA or genetic Fn14 knockout during TAA-mediated carcinogenesis. RESULTS: Our data reveal TWEAK and Fn14 overexpression in multiple human CCA cohorts, and Fn14 upregulation in early TAA-induced carcinogenesis. TWEAK regulated the secretion of factors from CC-SW-1 and SNU-1079 CCA cells, inducing polarisation of proinflammatory CD206+ macrophages. Pharmacological blocking of the TWEAK downstream target chemokine monocyte chemoattractant protein 1 (MCP-1 or CCL2) significantly reduced CCA xenograft growth, while TWEAK overexpression drove cancer-associated fibroblast proliferation and collagen deposition in the tumour niche. Genetic Fn14 ablation significantly reduced inflammatory, fibrogenic and ductular responses during carcinogenic TAA-mediated injury. CONCLUSION: These novel data provide evidence for the action of TWEAK/Fn14 on macrophage recruitment and phenotype, and cancer-associated fibroblast proliferation in CCA. Targeting TWEAK/Fn14 and its downstream signals may provide a means to inhibit CCA niche development and tumour growth. LAY SUMMARY: Cholangiocarcinoma is an aggressive, chemotherapy-resistant liver cancer. Interactions between tumour cells and cells that form a supportive environment for the tumour to grow are a source of this aggressiveness and resistance to chemotherapy. Herein, we describe interactions between tumour cells and their supportive environment via a chemical messenger, TWEAK and its receptor Fn14. TWEAK/Fn14 alters the recruitment and type of immune cells in tumours, increases the growth of cancer-associated fibroblasts in the tumour environment, and is a potential target to reduce tumour formation.
Assuntos
Neoplasias dos Ductos Biliares , Quimiocina CCL2/metabolismo , Colangiocarcinoma , Citocina TWEAK/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Animais , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Descoberta de Drogas , Humanos , Camundongos , Ratos , Transdução de Sinais , Microambiente Tumoral , Fator de Necrose Tumoral alfa/metabolismo , Regulação para CimaRESUMO
BACKGROUND & AIM: Following acetaminophen (APAP) overdose, acute liver injury (ALI) can occur in patients that present too late for N-acetylcysteine treatment, potentially leading to acute liver failure, systemic inflammation, and death. Macrophages influence the progression and resolution of ALI due to their innate immunological function and paracrine activity. Syngeneic primary bone marrow-derived macrophages (BMDMs) were tested as a cell-based therapy in a mouse model of APAP-induced ALI (APAP-ALI). METHODS: Several phenotypically distinct BMDM populations were delivered intravenously to APAP-ALI mice when hepatic necrosis was established, and then evaluated based on their effects on injury, inflammation, immunity, and regeneration. In vivo phagocytosis assays were used to interrogate the phenotype and function of alternatively activated BMDMs (AAMs) post-injection. Finally, primary human AAMs sourced from healthy volunteers were evaluated in immunocompetent APAP-ALI mice. RESULTS: BMDMs rapidly localised to the liver and spleen within 4 h of administration. Injection of AAMs specifically reduced hepatocellular necrosis, HMGB1 translocation, and infiltrating neutrophils following APAP-ALI. AAM delivery also stimulated proliferation in hepatocytes and endothelium, and reduced levels of several circulating proinflammatory cytokines within 24 h. AAMs displayed a high phagocytic activity both in vitro and in injured liver tissue post-injection. Crosstalk with the host innate immune system was demonstrated by reduced infiltrating host Ly6Chi macrophages in AAM-treated mice. Importantly, therapeutic efficacy was partially recapitulated using clinical-grade primary human AAMs in immunocompetent APAP-ALI mice, underscoring the translational potential of these findings. CONCLUSION: We identify that AAMs have value as a cell-based therapy in an experimental model of APAP-ALI. Human AAMs warrant further evaluation as a potential cell-based therapy for APAP overdose patients with established liver injury. LAY SUMMARY: After an overdose of acetaminophen (paracetamol), some patients present to hospital too late for the current antidote (N-acetylcysteine) to be effective. We tested whether macrophages, an injury-responsive leukocyte that can scavenge dead/dying cells, could serve as a cell-based therapy in an experimental model of acetaminophen overdose. Injection of alternatively activated macrophages rapidly reduced liver injury and reduced several mediators of inflammation. Macrophages show promise to serve as a potential cell-based therapy for acute liver injury.
Assuntos
Acetaminofen/intoxicação , Terapia Baseada em Transplante de Células e Tecidos/métodos , Doença Hepática Induzida por Substâncias e Drogas , Macrófagos , Comunicação Parácrina/imunologia , Animais , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocinas/sangue , Modelos Animais de Doenças , Humanos , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular , Regeneração Hepática/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Fagocitose , Resultado do TratamentoRESUMO
The disposal of apoptotic bodies by professional phagocytes is crucial to effective inflammation resolution. Our ability to improve the disposal of apoptotic bodies by professional phagocytes is impaired by a limited understanding of the molecular mechanisms that regulate the engulfment and digestion of the efferocytic cargo. Macrophages are professional phagocytes necessary for liver inflammation, fibrosis, and resolution, switching their phenotype from proinflammatory to restorative. Using sterile liver injury models, we show that the STAT3-IL-10-IL-6 axis is a positive regulator of macrophage efferocytosis, survival, and phenotypic conversion, directly linking debris engulfment to tissue repair.
Assuntos
Interleucina-10/metabolismo , Interleucina-6/metabolismo , Cirrose Hepática/patologia , Fígado/lesões , Macrófagos/imunologia , Fagocitose/imunologia , Fator de Transcrição STAT3/metabolismo , Transferência Adotiva , Animais , Apoptose/imunologia , Humanos , Fígado/patologia , Macrófagos/transplante , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Necrose/imunologia , Regeneração/fisiologia , Peixe-Zebra/embriologiaRESUMO
Liver fibrosis is the final common pathway of chronic or iterative liver damage. Advanced chronic fibrosis is described as cirrhosis with a loss of architecture and attendant functional failure and the development of life-threatening complications. However, compelling evidence from rodent models and human studies indicates that if the injury is removed liver fibrosis is reversible. Hepatocytes, activated hepatic stellate cells, endothelial and immune cells, particularly macrophages, cooperate in the establishment and resolution of liver fibrosis. Here the authors provide a short overview of the mechanisms regulating the profibrotic and proresolution response, with the aim of highlighting potential new therapeutic targets. Liver disease is a major unmet medical need; currently, the sole approaches are the withdrawal of the injurious stimulus and liver transplantation. The authors conclude with a brief review of the feasibility of macrophage-based cell therapy for liver fibrosis.
Assuntos
Cirrose Hepática/terapia , Fígado/citologia , Animais , Modelos Animais de Doenças , Matriz Extracelular/química , Células Estreladas do Fígado/fisiologia , Hepatócitos/fisiologia , Humanos , Imunidade Celular , Fígado/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/imunologia , Cirrose Hepática/patologia , Ativação de Macrófagos , Macrófagos/fisiologia , Metaloproteases/metabolismoRESUMO
OBJECTIVE: The signals causing the resolution of muscle inflammation are only partially characterized. The long pentraxin PTX3, which modulates leukocyte recruitment and activation, could contribute. METHODS: We analysed the expression of ptx3 after muscle injury and verified whether hematopoietic precursors are a source of the protein. The kinetics of regeneration and leukocytes infiltration, the accumulation of cell remnants and anti-histidyl-t-RNA synthetase autoantibodies were compared in wild-type and ptx3-deficient mice. RESULTS: Ptx3 expression was up-regulated three-five days after injury and restricted to the extracellular matrix. Cellular debris and leukocytes persisted in the muscle of ptx3-deficient mice for a long time after wild-type animals had healed. ptx3-deficient macrophages expressed receptors involved in apoptotic cell clearance and engulfed dead cells in vitro. Accumulation of cell debris in a pro-inflammatory microenvironment was not sufficient to elicit autoantibodies. CONCLUSION: PTX3 generated in response to muscle injury prompts the clearance of debris and the termination of the inflammatory response.
RESUMO
The embryonic endothelium is a known source of hematopoietic stem cells. Moreover, vessel-associated progenitors/stem cells with multilineage mesodermal differentiation potential, such as the 'embryonic mesoangioblasts', originate in vitro from the endothelium. Using a genetic lineage tracing approach, we show that early extra-embryonic endothelium generates, in a narrow time-window and prior to the hemogenic endothelium in the major embryonic arteries, hematopoietic cells that migrate to the embryo proper, and are subsequently found within the mesenchyme. A subpopulation of these cells, distinct from embryonic macrophages, co-expresses mesenchymal and hematopoietic markers. In addition, hemogenic endothelium-derived cells contribute to skeletal and smooth muscle, and to other mesodermal cells in vivo, and display features of embryonic mesoangioblasts in vitro. Therefore, we provide new insights on the distinctive characteristics of the extra-embryonic and embryonic hemogenic endothelium, and we identify the putative in vivo counterpart of embryonic mesoangioblasts, suggesting their identity and developmental ontogeny.
Assuntos
Linhagem da Célula , Hemangioblastos/citologia , Mesoderma/citologia , Animais , Biomarcadores/metabolismo , Caderinas/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Integrases/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Mesoderma/embriologia , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Músculo Esquelético/citologia , Músculo Esquelético/embriologia , Músculo Liso/citologia , Músculo Liso/embriologia , Receptores de Complemento 3b/metabolismo , Recombinação Genética/genéticaRESUMO
Signals of tissue necrosis, damage-associated molecular patterns (DAMPs), cause inflammation. Leukocytes migrating into injured tissues tonically release DAMPs, including the high mobility group box 1 protein (HMGB1). In the absence of suitable models, the relative role of DAMPs released because of necrosis or leukocyte activation has not, so far, been dissected. We have generated a mouse model lacking Hmgb1 in the hematopoietic system and studied the response to acute sterile injury of the skeletal muscle. Regenerating fibers are significantly less numerous at earlier time points and smaller at the end of the process. Leukocyte Hmgb1 licenses the skeletal muscle to react to hypoxia, to express angiopoietin-2, and to initiate angiogenesis in response to injury. Vascularization of the regenerating tissue is selectively jeopardized in the absence of leukocyte Hmgb1, revealing that it controls the nutrient and oxygen supply to the regenerating tissue. Altogether, our results reveal a novel nonredundant role for leukocyte Hmgb1 in the repair of injured skeletal muscle.
Assuntos
Angiopoietina-2/imunologia , Proteína HMGB1/imunologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/imunologia , Neovascularização Fisiológica/imunologia , Regeneração/imunologia , Angiopoietina-2/genética , Animais , Proteína HMGB1/genética , Leucócitos/imunologia , Camundongos , Camundongos Knockout , Músculo Esquelético/lesões , Neovascularização Fisiológica/genética , Regeneração/genéticaRESUMO
We compared the clinical performances of the BacT/Alert Plus (bioMérieux) and Bactec Plus (Becton Dickinson) aerobic and anaerobic blood culture (BC) media with adsorbent polymeric beads. Patients ≥ 16 years old with suspected bloodstream infections (BSIs) were enrolled in intensive care units and infectious disease wards. A single 40-ml blood sample was collected from each and used to inoculate (10 ml/bottle) one set of BacT/Alert Plus cultures and one set of Bactec Plus cultures, each set consisting of one aerobic and one anaerobic bottle. Cultures were incubated ≤ 5 days in the BacT/Alert 3D and Bactec FX instruments, respectively. A total of 128 unique BSI episodes were identified based on the recovery of clinically significant growth in 212 aerobic cultures (106 BacT/Alert and 106 Bactec) and 151 anaerobic cultures (82 BacT/Alert and 69 Bactec). The BacT/Alert aerobic medium had higher recovery rates for Gram-positive cocci (P = 0.024), whereas the Bactec aerobic medium was superior for recovery of Gram-negative bacilli (P = 0.006). BacT/Alert anaerobic medium recovery rates exceeded those of the Bactec anaerobic medium for total organisms (P = 0.003), Gram-positive cocci (P = 0.013), and Escherichia coli (P = 0.030). In terms of capacity for diagnosing the 128 septic episodes, the BacT/Alert and Bactec sets were comparable, although the former sets diagnosed more BSIs caused by Gram-positive cocci (P = 0.008). They also allowed earlier identification of coagulase-negative staphylococcal growth (mean, 2.8 h; P = 0.003) and growth in samples from patients not on antimicrobial therapy that yielded positive results (mean, 1.3 h; P < 0.001). Similarly high percentages of microorganisms in BacT/Alert and Bactec cultures (93.8% and 93.3%, respectively) were identified by direct matrix-assisted laser desorption ionization-time of flight mass spectrometry assay of BC broths. The BacT/Alert Plus media line appears to be a reliable, timesaving tool for routine detection of BSIs in the population we studied, although further studies are needed to evaluate their performance in other settings.
Assuntos
Bactérias/isolamento & purificação , Sangue/microbiologia , Meios de Cultura/química , Técnicas Microbiológicas/métodos , Sepse/diagnóstico , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Leveduras/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Leveduras/classificação , Adulto JovemRESUMO
Essential thrombocythemia (ET) and polycythemia vera (PV) are characterized by persistent platelet activation. The mechanisms involved in their clearance are poorly characterized. In the present study, we report that leukocytes were actively involved in platelet disposal in 51 patients with ET and 30 with PV, but not in 70 age- and sex-matched controls. The fraction of circulating neutrophils and monocytes that had phagocytosed platelets, as assessed by flow cytometry, was significantly higher in patients with PV or ET, independently of hydroxyurea treatment, than in controls. Platelet phagocytosis by circulating leukocytes was confirmed by confocal and electron microscopy. The lack of effect of hydroxyurea, which disrupts the P-selectin/P-selectin glycoprotein ligand 1 (PSGL-1) interaction, suggests a P-selectin-independent mechanism. This hypothesis was confirmed in an ad hoc animal model based on the in vivo injection of activated platelets from P-selectin(+/+) and P-selectin(-/-) mice. P-selectin expression was associated with an earlier and effective clearance of platelets by neutrophils. A second delayed, P-selectin-independent phase actively involved monocytes. Our results suggest that phagocytic clearance of platelets by leukocytes occurs in PV and ET, possibly involving P-selectin-dependent and -independent pathways, thus representing a novel mechanism to remove activated platelets from the circulation.
Assuntos
Plaquetas/metabolismo , Glicoproteínas de Membrana/metabolismo , Monócitos/metabolismo , Neutrófilos/metabolismo , Selectina-P/metabolismo , Fagocitose/genética , Policitemia Vera/metabolismo , Transdução de Sinais , Trombocitemia Essencial/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Plaquetas/imunologia , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Regulação da Expressão Gênica , Humanos , Hidroxiureia/farmacologia , Masculino , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Knockout , Microscopia Eletrônica , Pessoa de Meia-Idade , Monócitos/imunologia , Neutrófilos/imunologia , Selectina-P/imunologia , Fagocitose/imunologia , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/imunologia , Contagem de Plaquetas , Policitemia Vera/genética , Policitemia Vera/imunologia , Policitemia Vera/patologia , Transdução de Sinais/genética , Trombocitemia Essencial/genética , Trombocitemia Essencial/imunologia , Trombocitemia Essencial/patologiaRESUMO
Our aims were to identify (i) risk factors associated with the acquisition of multidrug-resistant (MDR, to 3 or more classes of antimicrobials) Proteus mirabilis isolates responsible for bloodstream infections (BSIs) and (ii) the impact on mortality of such infections. Risk factors for acquiring MDR P. mirabilis BSIs were investigated in a case-case-control study; those associated with mortality were assessed by comparing survivors and nonsurvivors in a cohort study. The population consisted of 99 adult inpatients with P. mirabilis BSIs identified by our laboratory over an 11-year period (1999 to 2009), 36 (33.3%) of which were caused by MDR strains, and the overall 21-day mortality rate was 30.3%. Acquisition of an MDR strain was independently associated with admission from a long-term care facility (odds ratio [OR], 9.78; 95% confidence interval [CI], 1.94 to 49.16), previous therapy with fluoroquinolones (OR, 5.52; 95% CI, 1.30 to 23.43) or oxyimino-cephalosporins (OR, 4.72; 95% CI, 1.31 to 16.99), urinary catheterization (OR, 3.89; 95% CI, 1.50 to 10.09), and previous hospitalization (OR, 2.68; 95% CI, 10.4 to 6.89). Patients with MDR P. mirabilis BSIs received inadequate initial antimicrobial therapy (IIAT, i.e., treatment with drugs to which the isolate displayed in vitro resistance) more frequently than those with non-MDR infections; they also had increased mortality and (for survivors) longer post-BSI-onset hospital stays. In multivariate regression analysis, 21-day mortality was associated with septic shock at BSI onset (OR, 12.97; 95% CI, 32.2 to 52.23), P. mirabilis isolates that were MDR (OR, 6.62; 95% CI, 16.4 to 26.68), and IIAT (OR, 9.85; 95% CI, 26.7 to 36.25), the only modifiable risk factor of the 3. These findings can potentially improve clinicians' ability to identify P. mirabilis BSIs likely to be MDR, thereby reducing the risk of IIAT--a major risk factor for mortality in these cases--and facilitating the prompt implementation of appropriate infection control measures.
Assuntos
Infecções por Proteus/tratamento farmacológico , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/patogenicidade , Idoso , Antibacterianos/uso terapêutico , Estudos de Casos e Controles , Cefalosporinas/uso terapêutico , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fluoroquinolonas/uso terapêutico , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Infecções por Proteus/mortalidade , Estudos Retrospectivos , Fatores de RiscoRESUMO
Human subcutaneous dirofilariasis caused by Dirofilaria repens is a vectorborne zoonotic disease mostly transmitted from dogs to humans through a mosquito's blood meal. Heartworms replication is amplified by the climate change, the increase of the range of suitable vectors, the facilitation of pet travel and the high rate of undiagnosed dirofilariasis in dogs. We describe a case of a young Romanian woman, resident in Rome for 18 years, that came to our attention for the appearance for five months of a subcutaneous nodule in the left arm. The patient reported that she first felt an insect bite, after which she noticed the onset of an erythematous and itchy wheal in the same skin area, turned into a subcutaneous nodule within a few weeks. The ultrasound examination showed a hypoechoic subcutaneous formation of 1,2 cm in diameter, containing a ribbon-like structure made up of hyperechoic parallel double lines, reminiscent of a warm. Based on this suspicion, we opted for the surgical radicalization of the lesion. The histological examination confirmed the radiological hypothesis of a warm-like foreign body morphologically compatible with Dirofilaria repens. Our experience shows how a clinical nonspecific skin nodular lesion may conceal an unexpected and unsettling diagnosis of subcutaneous Dirofilaria repens.
RESUMO
Liver transplantation is the only curative option for patients with end-stage liver disease. Despite improvements in surgical techniques, nonanastomotic strictures (characterized by the progressive loss of biliary tract architecture) continue to occur after liver transplantation, negatively affecting liver function and frequently leading to graft loss and retransplantation. To study the biological effects of organ preservation before liver transplantation, we generated murine models that recapitulate liver procurement and static cold storage. In these models, we explored the response of cholangiocytes and hepatocytes to cold storage, focusing on responses that affect liver regeneration, including DNA damage, apoptosis, and cellular senescence. We show that biliary senescence was induced during organ retrieval and exacerbated during static cold storage, resulting in impaired biliary regeneration. We identified decoy receptor 2 (DCR2)-dependent responses in cholangiocytes and hepatocytes, which differentially affected the outcome of those populations during cold storage. Moreover, CRISPR-mediated DCR2 knockdown in vitro increased cholangiocyte proliferation and decreased cellular senescence but had the opposite effect in hepatocytes. Using the p21KO model to inhibit senescence onset, we showed that biliary tract architecture was better preserved during cold storage. Similar results were achieved by administering senolytic ABT737 to mice before procurement. Last, we perfused senolytics into discarded human donor livers and showed that biliary architecture and regenerative capacities were better preserved. Our results indicate that cholangiocytes are susceptible to senescence and identify the use of senolytics and the combination of senotherapies and machine-perfusion preservation to prevent this phenotype and reduce the incidence of biliary injury after transplantation.
Assuntos
Sistema Biliar , Humanos , Camundongos , Animais , Constrição Patológica , Senescência CelularRESUMO
Biliary diseases can cause inflammation, fibrosis, bile duct destruction, and eventually liver failure. There are no curative treatments for biliary disease except for liver transplantation. New therapies are urgently required. We have therefore purified human biliary epithelial cells (hBECs) from human livers that were not used for liver transplantation. hBECs were tested as a cell therapy in a mouse model of biliary disease in which the conditional deletion of Mdm2 in cholangiocytes causes senescence, biliary strictures, and fibrosis. hBECs are expandable and phenotypically stable and help restore biliary structure and function, highlighting their regenerative capacity and a potential alternative to liver transplantation for biliary disease.
Assuntos
Transplante de Fígado , Animais , Ductos Biliares/patologia , Células Epiteliais/patologia , Fibrose , Humanos , Doadores Vivos , CamundongosRESUMO
Cells of the innate immune system sense tissue damage recognizing in the extracellular environment bona fide intracellular moieties, like high mobility group box 1 (HMGB1). In the case of tumors, HMGB1 recognition has a paradoxical dual effect: it promotes tumor neoangiogenesis and triggers protective anti-neoplastic T-cell responses. Recent advances in the study of HMGB1 have identified candidate molecular mechanisms underlying these apparently contrasting outcomes. A surprising role for innate receptors, including toll like receptor 4 (TLR4), in the response to conventional cancer radio and chemotherapy has also recently emerged, providing new insight into the mechanisms by which these treatments actually work.
Assuntos
Apoptose/imunologia , Proteína HMGB1/metabolismo , Neoplasias/imunologia , Neoplasias/patologia , Receptores Imunológicos/metabolismo , Receptores Toll-Like/metabolismo , Animais , Proteína HMGB1/imunologia , Humanos , Imunidade , Neoplasias/metabolismo , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/imunologia , Receptores Toll-Like/imunologiaRESUMO
BACKGROUND: Antibiotics represent the most widely prescribed drugs in children worldwide, both in hospital and community settings. A comprehensive approach to understanding the reasons and determinants of antibiotic prescription in the pediatric age is needed. This study aimed to assess parents' attitudes and perspectives about antibiotic use. METHODS: Prospective observational study was conducted in all Italian Regions between February 1 and April 30, 2020, using a standardized questionnaire. RESULTS: Six thousand six hundred twenty-five parents from all Italian regions completed the survey. Seventy-six percent of parents were aware that only bacteria are the target of antibiotics, but 92.9% knew that the antibiotic has no direct effect on fever. Antibiotic self-prescription (10.4%) or by remote consultation by phone call (19.9%) or message (9.6%) were relatively common. Ninety-three percent of parents were aware that excessive use of antibiotics could select resistant bacteria and 84.7% of them knew that they could actively fight antibiotic resistance. About two thirds of participants (66.1%) received information on antibiotic resistance from their family pediatrician. Parents born of Italy or those with lower income had a higher probability of having less information from pediatricians or knowledge of proper antibiotic use. DISCUSSION: Our study suggests that parents' knowledge and attitudes toward antibiotic use and prescription are improving compared with previous studies, while there is still a gap regarding antibiotic resistance, particularly on practices that can reduce its burden. Our study's negative finding is that families from low-income settings or those born abroad have significantly more misconceptions about important antibiotic practices.
Assuntos
Antibacterianos/administração & dosagem , Conhecimentos, Atitudes e Prática em Saúde , Pais/psicologia , Adulto , Criança , Pré-Escolar , Estudos Transversais , Resistência Microbiana a Medicamentos , Febre/tratamento farmacológico , Humanos , Lactente , Itália , Estudos Prospectivos , Infecções Respiratórias/tratamento farmacológico , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Macrophages play a key role in iron homeostasis. In peripheral tissues, they are known to polarize into classically activated (or M1) macrophages and alternatively activated (or M2) macrophages. Little is known on whether the polarization program influences the ability of macrophages to store or recycle iron and the molecular machinery involved in the processes. DESIGN AND METHODS: Inflammatory/M1 and alternatively activated/M2 macrophages were propagated in vitro from mouse bone-marrow precursors and polarized in the presence of recombinant interferon-γ or interleukin-4. We characterized and compared their ability to handle radioactive iron, the characteristics of the intracellular iron pools and the expression of molecules involved in internalization, storage and export of the metal. Moreover we verified the influence of iron on the relative ability of polarized macrophages to activate antigen-specific T cells. RESULTS: M1 macrophages have low iron regulatory protein 1 and 2 binding activity, express high levels of ferritin H, low levels of transferrin receptor 1 and internalize--albeit with low efficiency -iron only when its extracellular concentration is high. In contrast, M2 macrophages have high iron regulatory protein binding activity, express low levels of ferritin H and high levels of transferrin receptor 1. M2 macrophages have a larger intracellular labile iron pool, effectively take up and spontaneously release iron at low concentrations and have limited storage ability. Iron export correlates with the expression of ferroportin, which is higher in M2 macrophages. M1 and M2 cells activate antigen-specific, MHC class II-restricted T cells. In the absence of the metal, only M1 macrophages are effective. CONCLUSIONS: Cytokines that drive macrophage polarization ultimately control iron handling, leading to the differentiation of macrophages into a subset which has a relatively sealed intracellular iron content (M1) or into a subset endowed with the ability to recycle the metal (M2).
Assuntos
Regulação da Expressão Gênica/fisiologia , Ferro/metabolismo , Ativação de Macrófagos/fisiologia , Macrófagos/metabolismo , Animais , Apoferritinas/biossíntese , Apoferritinas/imunologia , Proteínas de Transporte de Cátions/biossíntese , Proteínas de Transporte de Cátions/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/imunologia , Inflamação/metabolismo , Interferon gama/imunologia , Interferon gama/metabolismo , Interferon gama/farmacologia , Interleucina-4/imunologia , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Ferro/imunologia , Proteína 1 Reguladora do Ferro/biossíntese , Proteína 1 Reguladora do Ferro/imunologia , Proteína 2 Reguladora do Ferro/biossíntese , Proteína 2 Reguladora do Ferro/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/fisiologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/imunologia , Camundongos , Receptores da Transferrina/biossíntese , Receptores da Transferrina/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
We report a case of a 13-year-old immunocompetent male with multifocal tubercular osteomyelitis involving several spinal segments, small bones of the hands, and the scalp, who started with progressively back pain and enlarging painful swelling on the palms of hands, fatigue, and irregular fever. All the hand lesions were firm, mildly tender, and covered by ulcerated skin with serous discharge from the site. Magnetic resonance showed lesions of the right fifth metacarpal, of the right intermediate phalanx of the fourth finger, of the left second metacarpal, and of most vertebral bodies of the cervical, dorsal, lumbar, and sacral spine. The nucleic acid amplification test and the final culture from the drainage of the hands' lesion were positive for Mycobacterium tuberculosis. The patient received a standard antitubercular treatment for 12 months with clinical improvement.