RESUMO
Ischemia reperfusion injury (IRI) is the predominant tissue insult associated with organ transplantation. Treatment with carbon monoxide (CO) modulates the innate immune response associated with IRI and accelerates tissue recovery. The mechanism has been primarily descriptive and ascribed to the ability of CO to influence inflammation, cell death, and repair. In a model of bilateral kidney IRI in mice, we elucidate an intricate relationship between CO and purinergic signaling involving increased CD39 ectonucleotidase expression, decreased expression of Adora1, with concomitant increased expression of Adora2a/2b. This response is linked to a >20-fold increase in expression of the circadian rhythm protein Period 2 (Per2) and a fivefold increase in serum erythropoietin (EPO), both of which contribute to abrogation of kidney IRI. CO is ineffective against IRI in Cd39-/- and Per2-/- mice or in the presence of a neutralizing antibody to EPO. Collectively, these data elucidate a cellular signaling mechanism whereby CO modulates purinergic responses and circadian rhythm to protect against injury. Moreover, these effects involve CD39- and adenosinergic-dependent stabilization of Per2. As CO also increases serum EPO levels in human volunteers, these findings continue to support therapeutic use of CO to treat IRI in association with organ transplantation, stroke, and myocardial infarction.
Assuntos
Antígenos CD/metabolismo , Apirase/metabolismo , Monóxido de Carbono/administração & dosagem , Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Proteínas Circadianas Period/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Antígenos CD/genética , Apirase/genética , Modelos Animais de Doenças , Humanos , Rim/irrigação sanguínea , Rim/metabolismo , Rim/fisiopatologia , Nefropatias/genética , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Circadianas Period/genética , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismoRESUMO
Pulmonary fibrosis is a result of an abnormal wound healing in lung tissue triggered by an excessive accumulation of extracellular matrix proteins, loss of tissue elasticity, and debit of ventilatory function. NKT cells are a major source of Th1 and Th2 cytokines and may be crucial in the polarization of M1/M2 macrophages in pulmonary fibrogenesis. Although there appears to be constant scientific progress in that field, pulmonary fibrosis still exhibits no current cure. From these facts, we hypothesized that NKT cells could influence the development of pulmonary fibrosis via modulation of macrophage activation. Wild type (WT) and NKT type I cell-deficient mice (Jα18-/-) were subjected to the protocol of bleomycin-induced pulmonary fibrosis with or without treatment with NKT cell agonists α-galactosylceramide and sulfatide. The participation of different cell populations, collagen deposition, and protein levels of different cytokines involved in inflammation and fibrosis was evaluated. The results indicate a benign role of NKT cells in Jα18-/- mice and in wild-type α-galactosylceramide-sulfatide-treated groups. These animals presented lower levels of collagen deposition, fibrogenic molecules such as TGF-ß and vimentin and improved survival rates. In contrast, WT mice developed a Th2-driven response augmenting IL-4, 5, and 13 protein synthesis and increased collagen deposition. Furthermore, the arginase-1 metabolic pathway was downregulated in wild-type NKT-activated and knockout mice indicating lower activity of M2 macrophages in lung tissue. Hence, our data suggest that NKT cells play a protective role in this experimental model by down modulating the Th2 milieu, inhibiting M2 polarization and finally preventing fibrosis.
Assuntos
Bleomicina/farmacologia , Macrófagos/fisiologia , Células T Matadoras Naturais/fisiologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/fisiopatologia , Animais , Colágeno/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Galactosilceramidas/farmacologia , Inflamação/metabolismo , Pulmão/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/efeitos dos fármacos , Células T Matadoras Naturais/metabolismo , Fenótipo , Fibrose Pulmonar/metabolismo , Células Th1/metabolismo , Células Th2/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Vimentina/metabolismoRESUMO
Chemokines are a large family of proteins that, once associated to its receptor on leukocytes, stimulate their movement and migration from blood to tissues. Once in the tissue, immune cells trigger inflammation that, when uncontrolled, leads to fibrosis development. Among the immune cells, macrophages take a special role in fibrosis formation, since macrophage depletion reflects less collagen deposition. The majority of tissue macrophages is derived from monocytes, especially monocytes expressing the chemokine receptor CCR2. Here, we investigated the role of infiltrating CCR2+ cells in the development of fibrosis, and specifically, the dynamic of infiltration of these cells into kidneys under chronic obstructive lesion. Using liposome-encapsulated clodronate, we observed that macrophage depletion culminated in less collagen deposition and reduced chemokines milieu that were released in the damaged kidney after obstructive nephropathy. We also obstructed the kidneys of CCL3-/-, CCR2-/-, CCR4-/-, CCR5-/-, and C57BL/6 mice and we found that among all animals, CCR2-/- mice demonstrated the more robust protection, reflected by less inflammatory and Th17-related cytokines and less collagen formation. Next we evaluated the dynamic of CCR2+/rfp cell infiltration and we observed that they adhere onto the vessels at early stages of disease, culminating in increased recruitment of CCR2+/rfp cells at later stages. On the other hand, CCR2rfp/rfp animals exhibited less fibrosis formation and reduced numbers of recruited cells at later stages. We have experimentally demonstrated that inflammatory CCR2+ cells that reach the injured kidney at initial stages after tissue damage are responsible for the fibrotic pattern observed at later time points in the context of UUO.
Assuntos
Fibrose/patologia , Inflamação/patologia , Nefropatias/patologia , Rim/patologia , Monócitos/patologia , Receptores CCR2/metabolismo , Animais , Colágeno/metabolismo , Citocinas/metabolismo , Fibrose/metabolismo , Inflamação/metabolismo , Rim/metabolismo , Nefropatias/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/metabolismoRESUMO
Short-chain fatty acids (SCFAs) are fermentation end products produced by the intestinal microbiota and have anti-inflammatory and histone deacetylase-inhibiting properties. Recently, a dual relationship between the intestine and kidneys has been unraveled. Therefore, we evaluated the role of SCFA in an AKI model in which the inflammatory process has a detrimental role. We observed that therapy with the three main SCFAs (acetate, propionate, and butyrate) improved renal dysfunction caused by injury. This protection was associated with low levels of local and systemic inflammation, oxidative cellular stress, cell infiltration/activation, and apoptosis. However, it was also associated with an increase in autophagy. Moreover, SCFAs inhibited histone deacetylase activity and modulated the expression levels of enzymes involved in chromatin modification. In vitro analyses showed that SCFAs modulated the inflammatory process, decreasing the maturation of dendritic cells and inhibiting the capacity of these cells to induce CD4(+) and CD8(+) T cell proliferation. Furthermore, SCFAs ameliorated the effects of hypoxia in kidney epithelial cells by improving mitochondrial biogenesis. Notably, mice treated with acetate-producing bacteria also had better outcomes after AKI. Thus, we demonstrate that SCFAs improve organ function and viability after an injury through modulation of the inflammatory process, most likely via epigenetic modification.
Assuntos
Injúria Renal Aguda/prevenção & controle , Ácidos Graxos Voláteis/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Injúria Renal Aguda/metabolismo , Animais , Bifidobacterium , Linhagem Celular , Células Dendríticas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Inflamação/tratamento farmacológico , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Probióticos/uso terapêutico , Traumatismo por Reperfusão/metabolismoRESUMO
Natural killer T (NKT) cells are a subset of lymphocytes that reacts to glycolipids presented by CD1d. Invariant NKT cells (iNKT) correspond to >90% of the total population of NKTs and reacts to α-galactosylceramide (αGalCer). αGalCer promotes a complex mixture of Th1 and Th2 cytokines, as interferon (IFN)-γ and interleukin (IL)-4. NKT cells and IFN-γ are known to participate in some models of renal diseases, but further studies are still necessary to elucidate their mechanisms. The aim of our study was to analyze the participation of iNKT cells in an experimental model of tubule-interstitial nephritis. We used 8-wk-old C57BL/6j, Jα18KO and IFN-γKO mice. They were fed a 0.25% adenine diet for 10 d. Both adenine-fed wild-type (WT) and Jα18KO mice exhibited renal dysfunction, but adenine-fed Jα18KO mice presented higher expression of kidney injury molecule-1 (KIM-1), tumor necrosis factor (TNF)-α and type I collagen. To analyze the role of activated iNKT cells in our model, we administered αGalCer in WT mice during adenine ingestion. After αGalCer injection, we observed a significant reduction in serum creatinine, proinflammatory cytokines and renal fibrosis. However, this improvement in renal function was not observed in IFN-γKO mice after αGalCer treatment and adenine feeding, illustrating that this cytokine plays a role in our model. Our findings may suggest that IFN-γ production is one of the factors contributing to improved renal function after αGalCer administration.
Assuntos
Galactosilceramidas/administração & dosagem , Interferon gama/genética , Nefrite/tratamento farmacológico , Insuficiência Renal/tratamento farmacológico , Adenina/toxicidade , Animais , Antígenos CD1d/biossíntese , Antígenos CD1d/genética , Colágeno Tipo I/biossíntese , Receptor Celular 1 do Vírus da Hepatite A , Humanos , Interleucina-4/biossíntese , Interleucina-4/genética , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/patologia , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Células T Matadoras Naturais/efeitos dos fármacos , Células T Matadoras Naturais/imunologia , Nefrite/induzido quimicamente , Nefrite/genética , Nefrite/patologia , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/genética , Insuficiência Renal/patologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor ß (TGF-ß) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-ß/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.
Assuntos
Rim/metabolismo , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Insuficiência Renal Crônica/metabolismo , Animais , Azepinas , Colágeno/metabolismo , Modelos Animais de Doenças , Fibrose , Rim/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Nefrite/metabolismo , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Insuficiência Renal Crônica/patologia , Triazóis , Obstrução UreteralRESUMO
BACKGROUND/AIMS: We investigated the effects of leptin in the development of lipopolysaccharide (LPS)-induced acute lung inflammation (ALI) in lean mice. METHODS: Mice were administered leptin (1.0µg/g) or leptin (1.0µg/g) followed by LPS (1.5µg/g) intranasally. Additionally, some animals were given LPS (1.5µg/g) or saline intranasally alone, as a control. Tissue samples and fluids were collected six hours after instillation. RESULTS: We demonstrated that leptin alone did not induce any injury. Local LPS exposure resulted in significant acute lung inflammation, characterized by a substantial increase in total cells, mainly neutrophils, in bronchoalveolar lavages (BAL). We also observed a significant lymphocyte influx into the lungs associated with enhanced lung expression of chemokines and cytokines (KC, RANTES, TNF-α, IFN-γ, GM-CSF and VEGF). LPS-induced ALI was characterized by the enhanced expression of ICAM-1 and iNOS in the lungs. Mice that received LPS showed an increase in insulin levels. Leptin, when administered prior to LPS instillation, abolished all of these effects. LPS induced an increase in corticosterone levels, and leptin potentiated this event. CONCLUSION: These data suggest that exogenous leptin may promote protection during sepsis, and downregulation of the insulin levels and upregulation of corticosterone may be important mechanisms in the amelioration of LPS-induced ALI.
Assuntos
Lesão Pulmonar Aguda , Corticosterona/farmacologia , Insulina/farmacologia , Leptina/farmacologia , Lipopolissacarídeos/toxicidade , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Citocinas/biossíntese , Molécula 1 de Adesão Intercelular/biossíntese , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/biossínteseRESUMO
Formaldehyde (FA) is an environmental and occupational pollutant, and its toxic effects on the immune system have been shown. Nevertheless, no data are available regarding the programming mechanisms after FA exposure and its repercussions for the immune systems of offspring. In this study, our objective was to investigate the effects of low-dose exposure of FA on pregnant rats and its repercussion for the development of allergic lung inflammation in offspring. Pregnant Wistar rats were assigned in 3 groups: P (rats exposed to FA (0.75 ppm, 1 h/day, 5 days/week, for 21 days)), C (rats exposed to vehicle of FA (distillated water)) and B (rats non-manipulated). After 30 days of age, the offspring was sensitised with ovalbumin (OVA)-alum and challenged with aerosolized OVA (1%, 15 min, 3 days). After 24 h the OVA challenge the parameters were evaluated. Our data showed that low-dose exposure to FA during pregnancy induced low birth weight and suppressed the development of allergic lung inflammation and tracheal hyperresponsiveness in offspring by mechanisms mediated by reduced anaphylactic antibodies synthesis, IL-6 and TNF-alpha secretion. Elevated levels of IL-10 were found. Any systemic alteration was detected in the exposed pregnant rats, although oxidative stress in the uterine environment was evident at the moment of the delivery based on elevated COX-1 expression and reduced cNOS and SOD-2 in the uterus. Therefore, we show the putative programming mechanisms induced by FA on the immune system for the first time and the mechanisms involved may be related to oxidative stress in the foetal microenvironment.
Assuntos
Alveolite Alérgica Extrínseca/imunologia , Modelos Animais de Doenças , Resistência à Doença/efeitos dos fármacos , Formaldeído/administração & dosagem , Pulmão/efeitos dos fármacos , Oxidantes/administração & dosagem , Efeitos Tardios da Exposição Pré-Natal , Poluentes Atmosféricos/toxicidade , Alveolite Alérgica Extrínseca/induzido quimicamente , Alveolite Alérgica Extrínseca/metabolismo , Alveolite Alérgica Extrínseca/prevenção & controle , Animais , Asma/induzido quimicamente , Asma/imunologia , Asma/metabolismo , Asma/prevenção & controle , Peso ao Nascer/efeitos dos fármacos , Citocinas/genética , Citocinas/metabolismo , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Formaldeído/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Exposição Materna/efeitos adversos , Oxidantes/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/imunologia , Mucosa Respiratória/metabolismo , Traqueia/efeitos dos fármacos , Traqueia/imunologia , Traqueia/metabolismoRESUMO
Macrophages play a special role in the onset of several diseases, including acute and chronic kidney injuries. In this sense, tubule interstitial nephritis (TIN) represents an underestimated insult, which can be triggered by different stimuli and, in the absence of a proper regulation, can lead to fibrosis deposition. Based on this perception, we evaluated the participation of macrophage recruitment in the development of TIN. Initially, we provided adenine-enriched food to WT and searched for macrophage presence and action in the kidney. Also, a group of animals were depleted of macrophages with the clodronate liposome while receiving adenine-enriched diet. We collected blood and renal tissue from these animals and renal function, inflammation, and fibrosis were evaluated. We observed higher expression of chemokines in the kidneys of adenine-fed mice and a substantial protection when macrophages were depleted. Then, we specifically investigated the role of some key chemokines, CCR5 and CCL3, in this TIN experimental model. Interestingly, CCR5 KO and CCL3 KO animals showed less renal dysfunction and a decreased proinflammatory profile. Furthermore, in those animals, there was less profibrotic signaling. In conclusion, we can suggest that macrophage infiltration is important for the onset of renal injury in the adenine-induced TIN.
Assuntos
Injúria Renal Aguda/metabolismo , Adenina/toxicidade , Quimiocina CCL3/metabolismo , Rim/metabolismo , Macrófagos/metabolismo , Receptores CCR5/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Animais , Quimiocina CCL3/genética , Citometria de Fluxo , Rim/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Nefrite Intersticial/metabolismo , Receptores CCR5/genéticaRESUMO
BACKGROUND/AIMS: Renal ischaemia-reperfusion injury (IRI) is a systemic inflammatory process in which Th1 responses predominate affecting other organs including the lungs. The present study explored the phagocytic and microbicidal capacity of macrophages in rats with lung inflammation that underwent IRI. METHODS: The alveolar macrophages of rats sensitised to OVA were evaluated for phagocytosis and bacterial killing 24h after antigen challenge in animals with or without prior submission to 60 min of renal ischaemia. RESULTS: Bronchoalveolar lavage had a high level of cellular infiltrate in immunised animals (420%) compared with control animals; IRI significantly reduced this infiltration (52%). Macrophages from animals immunised and challenged with OVA presented a 10x increase in phagocytic capacity compared to the control group, whereas immunised animals subjected to IRI showed a reduction in the phagocytic index of 68%. The killing of Klebsiella pneumoniae by macrophages from immunised animals was higher (56%) compared with the control group but reduced in animals submitted to IRI (45%). Immunised and challenged group showed an increase in gene expression levels of IL-10(450%), HO-1 (259%), INF-γ (460%) and MCP-1 (370%) compared to the immunised group subjected to IRI. CONCLUSIONS: Renal ischaemia and reperfusion injury apparently alters the phagocytic and microbicidal capacity of macrophages, reducing lung inflammation to OVA.
Assuntos
Injúria Renal Aguda/imunologia , Macrófagos Alveolares/fisiologia , Fagocitose/fisiologia , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Líquido da Lavagem Broncoalveolar/citologia , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Klebsiella pneumoniae/fisiologia , Macrófagos Alveolares/citologia , Macrófagos Alveolares/imunologia , Masculino , Óxido Nítrico/metabolismo , Ovalbumina/imunologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologiaRESUMO
Inflammation contributes to the pathogenesis of chronic kidney disease (CKD). Molecules released by the inflamed injured tissue can activate toll-like receptors (TLRs), thereby modulating macrophage and CD4(+) T-cell activity. We propose that in renal fibrogenesis, M2 macrophages are recruited and activated in a T helper subset 2 cell (T(H)2)-prone inflammatory milieu in a MyD88-dependent manner. Mice submitted to unilateral ureteral ligation (UUO) demonstrated an increase in macrophage infiltration with collagen deposition after 7 d. Conversely, TLR2, TLR4 and MyD88 knockout (KO) mice had an improved renal function together with diminished T(H)2 cytokine production and decreased fibrosis formation. Moreover, TLR2, TLR4 and MyD88 KO animals exhibited less M2 macrophage infiltration, namely interleukin (IL)-10(+) and CD206(+) CD11b(high) cells, at 7 d after surgery. We evaluated the role of a T(H)2 cytokine in this context, and observed that the absence of IL-4 was associated with better renal function, decreased IL-13 and TGF-ß levels, reduced arginase activity and a decrease in fibrosis formation when compared with IL-12 KO and wild-type (WT) animals. Indeed, the better renal outcomes and the decreased fibrosis formation were restricted to the deficiency of IL-4 in the hematopoietic compartment. Finally, macrophage depletion, rather than the absence of T cells, led to reduced lesions of the glomerular filtration barrier and decreased collagen deposition. These results provide evidence that future therapeutic strategies against renal fibrosis should be accompanied by the modulation of the M1:M2 and T(H)1:T(H)2 balance, as T(H)2 and M2 cells are predictive of fibrosis toward mechanisms that are sensed by innate immune response and triggered in a MyD88-dependent pathway.
Assuntos
Imunidade/imunologia , Rim/patologia , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais/imunologia , Células Th2/imunologia , Animais , Citocinas/metabolismo , Fibrose , Hematopoese , Interleucina-12/metabolismo , Interleucina-4/deficiência , Rim/imunologia , Rim/fisiopatologia , Nefropatias/imunologia , Nefropatias/patologia , Nefropatias/fisiopatologia , Testes de Função Renal , Ligadura , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Ureter/patologia , Obstrução Ureteral/complicações , Obstrução Ureteral/imunologia , Obstrução Ureteral/patologiaRESUMO
Focal and segmental glomerulosclerosis (FSGS) is one of the most important causes of end-stage renal failure. The bradykinin B1 receptor has been associated with tissue inflammation and renal fibrosis. To test for a role of the bradykinin B1 receptor in podocyte injury, we pharmacologically modulated its activity at different time points in an adriamycin-induced mouse model of FSGS. Estimated albuminuria and urinary protein to creatinine ratios correlated with podocytopathy. Adriamycin injection led to loss of body weight, proteinuria, and upregulation of B1 receptor mRNA. Early treatment with a B1 antagonist reduced albuminuria and glomerulosclerosis, and inhibited the adriamycin-induced downregulation of podocin, nephrin, and α-actinin-4 expression. Moreover, delayed treatment with antagonist also induced podocyte protection. Conversely, a B1 agonist aggravated renal dysfunction and even further suppressed the levels of podocyte-related molecules. Thus, we propose that kinin has a crucial role in the pathogenesis of FSGS operating through bradykinin B1 receptor signaling.
Assuntos
Bradicinina/análogos & derivados , Glomerulosclerose Segmentar e Focal/induzido quimicamente , Podócitos/efeitos dos fármacos , Receptor B1 da Bradicinina/agonistas , Transdução de Sinais/efeitos dos fármacos , Actinina/metabolismo , Albuminúria/induzido quimicamente , Albuminúria/metabolismo , Albuminúria/prevenção & controle , Animais , Bradicinina/farmacologia , Bradicinina/toxicidade , Antagonistas de Receptor B1 da Bradicinina , Modelos Animais de Doenças , Doxorrubicina , Regulação da Expressão Gênica/efeitos dos fármacos , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/metabolismo , Glomerulosclerose Segmentar e Focal/patologia , Glomerulosclerose Segmentar e Focal/prevenção & controle , Heme Oxigenase-1/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Podócitos/metabolismo , Podócitos/patologia , RNA Mensageiro/metabolismo , Receptor B1 da Bradicinina/genética , Receptor B1 da Bradicinina/metabolismo , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/metabolismoRESUMO
Mesenchymal stem cells (MSCs) have regenerative properties in acute kidney injury, but their role in chronic kidney diseases is still unknown. More specifically, it is not known whether MSCs halt fibrosis. The purpose of this work was to investigate the role of MSCs in fibrogenesis using a model of chronic renal failure. MSCs were obtained from the tibias and femurs of male Wistar-EPM rats. Female Wistar rats were subjected to the remnant model, and 2|x|10(5) MSCs were intravenously administrated to each rat every other week for 8 weeks or only once and followed for 12 weeks. SRY gene expression was observed in female rats treated with male MSCs, and immune localization of CD73(+)CD90(+) cells at 8 weeks was also assessed. Serum and urine analyses showed an amelioration of functional parameters in MSC-treated animals at 8 weeks, but not at 12 weeks. Masson's trichrome and Sirius red staining demonstrated reduced levels of fibrosis in MSC-treated animals. These results were corroborated by reduced vimentin, type I collagen, transforming growth factor beta, fibroblast specific protein 1 (FSP-1), monocyte chemoattractant protein 1, and Smad3 mRNA expression and alpha smooth muscle actin and FSP-1 protein expression. Renal interleukin (IL)-6 and tumor necrosis factor alpha mRNA expression levels were significantly decreased after MSC treatment, whereas IL-4 and IL-10 expression levels were increased. All serum cytokine expression levels were decreased in MSC-treated animals. Taken together, these results suggested that MSC therapy can indeed modulate the inflammatory response that follows the initial phase of a chronic renal injury. The immunosuppressive and remodeling properties of MSCs may be involved in the decreased fibrosis in the kidney.
Assuntos
Reprogramação Celular , Nefropatias/imunologia , Nefropatias/patologia , Células-Tronco Mesenquimais/imunologia , Animais , Diferenciação Celular , Citocinas/genética , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Fibrose/genética , Fibrose/imunologia , Fibrose/fisiopatologia , Fibrose/cirurgia , Regulação da Expressão Gênica , Nefropatias/genética , Nefropatias/fisiopatologia , Testes de Função Renal , Masculino , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Ratos , Ratos WistarRESUMO
The antitumor effect of metformin has been demonstrated in several types of cancer; however, the mechanisms involved are incompletely understood. In this study, we showed that metformin acts directly on melanoma cells as well as on the tumor microenvironment, particularly in the context of the immune response. In vitro, metformin induces a complex interplay between apoptosis and autophagy in melanoma cells. The anti-metastatic activity of metformin in vivo was assessed in several mouse models challenged with B16F10 cells. Metformin's activity was, in part, immune system-dependent, whereas its antitumor properties were abrogated in immunodeficient (NSG) mice. Metformin treatment increased the number of lung CD8-effector-memory T and CD4+Foxp3+IL-10+ T cells in B16F10-transplanted mice. It also decreased the levels of Gr-1+CD11b+ and RORγ+ IL17+CD4+ cells in B16F10-injected mice and the anti-metastatic effect was impaired in RAG-1-/- mice challenged with B16F10 cells, suggesting an important role for T cells in the protection induced by metformin. Finally, metformin in combination with the clinical metabolic agents rapamycin and sitagliptin showed a higher antitumor effect. The metformin/sitagliptin combination was effective in a BRAFV600E/PTEN tamoxifen-inducible murine melanoma model. Taken together, these results suggest that metformin has a pronounced effect on melanoma cells, including the induction of a strong protective immune response in the tumor microenvironment, leading to tumor growth control, and the combination with other metabolic agents may increase this effect.
RESUMO
Acute kidney injury (AKI) and chronic kidney disease (CKD) are major concerns in worldwide public health, and their pathophysiology involves immune cells activation, being macrophages one of the main players of both processes. It is suggested that metabolic pathways could contribute to macrophage modulation and phosphatidylinositol3 kinase (PI3K) pathway was shown to be activated in kidneys subjected to ischemia and reperfusion as well as unilateral ureteral obstruction (UUO). Although PI3K inhibition is mostly associated with anti-inflammatory response, its use in kidney injuries has been shown controversial results, which indicates the need for further studies. Our aim was to unveil the role of PI3Kγ in macrophage polarization and in kidney diseases development. We analyzed bone-marrow macrophages polarization from wild-type (WT) and PI3Kγ knockout (PI3K KO) animals. We observed increased expression of M1 (CD86, CCR7, iNOS, TNF, CXCL9, CXCL10, IL-12 and IL-23) and decreased of M2 (CD206, Arg-1, FIZZ1 and YM1) markers in the lack of PI3Kγ. And this modulation was accompanied by higher levels of inflammatory cytokines in PI3K KO M1 cells. PI3K KO mice had increased M1 in steady state kidneys, and no protection was observed in these mice after acute and chronic kidney insults. On the contrary, they presented higher levels of protein-to-creatinine ratio and Kim-1 expression and increased tubular injury. In conclusion, our findings demonstrated that the lack of PI3Kγ favors M1 macrophages polarization providing an inflammatory-prone environment, which does not prevent kidney diseases progression.
Assuntos
Injúria Renal Aguda/prevenção & controle , Polaridade Celular , Classe Ib de Fosfatidilinositol 3-Quinase/fisiologia , Macrófagos/fisiologia , Insuficiência Renal Crônica/prevenção & controle , Animais , Progressão da Doença , Inflamação/etiologia , Interleucina-12/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Obstrução Ureteral/complicaçõesRESUMO
Uric acid is a damage-associated molecular pattern (DAMP), released from ischemic tissues and dying cells which, when crystalized, is able to activate the NLRP3 inflammasome. Soluble uric acid (sUA) is found in high concentrations in the serum of great apes, and even higher in some diseases, before the appearance of crystals. In the present study, we sought to investigate whether uric acid, in the soluble form, could also activate the NLRP3 inflammasome and induce the production of IL-1ß. We monitored ROS, mitochondrial area and respiratory parameters from macrophages following sUA stimulus. We observed that sUA is released in a hypoxic environment and is able to induce IL-1ß release. This process is followed by production of mitochondrial ROS, ASC speck formation and caspase-1 activation. Nlrp3-/- macrophages presented a protected redox state, increased maximum and reserve oxygen consumption ratio (OCR) and higher VDAC protein levels when compared to WT and Myd88-/- cells. Using a disease model characterized by increased sUA levels, we observed a correlation between sUA, inflammasome activation and fibrosis. These findings suggest sUA activates the NLRP3 inflammasome. We propose that future therapeutic strategies for renal fibrosis should include strategies that block sUA or inhibit its recognition by phagocytes.
Assuntos
Inflamassomos/metabolismo , Nefropatias/metabolismo , Rim/patologia , Macrófagos/fisiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ácido Úrico/metabolismo , Animais , Caspase 1/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Fibrose , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Canais de Ânion Dependentes de Voltagem/metabolismoRESUMO
INTRODUCTION: Macrophages are heterogeneous and thus can be correlated with distinct tissue outcomes after injury. Conflicting data have indicated that the M2-related phenotype directly triggers fibrosis. Conversely, we hypothesize here that the inflammatory milieu provided by early infiltration of pro-inflammatory macrophages dictates tissue scarring after injury. METHODS AND RESULTS: We first determined that tissue-localized macrophages exhibit a pro-inflammatory phenotype (p40IL12(+)CCR7(+)CD11b(+)) during the early phase of a chronic injury model, in contrast to a pro-resolving phenotype (Arg1(+)IL10(+)CD206(+)CD11b(+)) at a later stage. Then, we evaluated the effects of injecting macrophages differentiated in vitro in the presence of IFNγ + LPS or IL4 + IL13 or non-differentiated macrophages (hereafter, M0) on promoting inflammation and progression of chronic injury in macrophage-depleted mice. In addition to enhancing the expression of pro-inflammatory cytokines, the injection of M (IFNγ + LPS), but not M (IL4 + IL13) or M0, accentuated fibrosis while augmenting levels of anti-inflammatory molecules, increasing collagen deposition and impairing organ function. We observed a similar profile after injection of sorted CCR7(+)CD11b(+) cells and a more pronounced effect of M (IFNγ + LPS) cells originated from Stat6(-/-) mice. The injection of M (IFNγ + LPS) cells was associated with the up-regulation of inflammation- and fibrosis-related proteins (Thbs1, Mmp7, Mmp8, and Mmp13). CONCLUSIONS: Our results suggest that pro-inflammatory macrophages promote microenvironmental changes that may lead to fibrogenesis by inducing an inflammatory milieu that alters a network of extracellular-related genes, culminating in tissue fibrosis.
RESUMO
Formaldehyde (FA) is an environmental and occupational pollutant that induces programming mechanisms on the acquired immune host defense in offspring when exposed during the prenatal period. Hence, here we investigated whether the exposure of FA on pregnant rats could affect the development of an innate acute lung injury in offspring induced by lipopolissacaride (LPS) injection. Pregnant Wistar rats were exposed to FA (0.92 mg/m(3)) or vehicle (distillated water), both 1 h/day, 5 days/week, from 1 to 21 days of pregnancy. Non-manipulated rats were used as control. After 30 days of birth, the offspring was submitted to injection of LPS (Salmonella abortus equi, 5 mg/kg, i.p.). Systemic and lung inflammatory parameters were evaluated 24 h later. Exposure to FA during gestation abolished the development of acute lung injury in offspring, as observed by reduced number of leukocytes in the bronchoalveolar fluid (BAL), in the blood and in the bone marrow, and decreased myeloperoxidase activity in the lung. Moreover, phagocytes from BAL presented normal phagocytosis, but reduced oxidative burst. Alterations on the profile of inflammatory cytokines were evidenced by reduced mRNA levels of IL-6 and elevated levels of IL-10 and IFN gamma in the lung tissue. Indeed, mRNA levels of toll-likereceptor-4 and nuclear factor-kappa B translocation into the nucleus were also reduced. Additionally, hyperresponsiveness to methacholine was blunted in the trachea of offspring of FA exposed mothers. Together, our data clearly show that FA exposure in the prenatal period modifies the programming mechanisms of the innate defense in the offspring leading to impaired defense against infections.
Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Poluentes Atmosféricos/toxicidade , Formaldeído/toxicidade , Imunidade Inata/efeitos dos fármacos , Exposição por Inalação/efeitos adversos , Pulmão/efeitos dos fármacos , Exposição Materna/efeitos adversos , Pneumonia/prevenção & controle , Efeitos Tardios da Exposição Pré-Natal , Transporte Ativo do Núcleo Celular , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/fisiopatologia , Animais , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Idade Gestacional , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Pulmão/imunologia , Pulmão/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , Fagócitos/metabolismo , Pneumonia/induzido quimicamente , Pneumonia/genética , Pneumonia/imunologia , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Gravidez , RNA Mensageiro/metabolismo , Ratos Wistar , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Traqueia/efeitos dos fármacos , Traqueia/fisiopatologiaRESUMO
SIGNIFICANCE: Heme degradation, which was described more than 30 years ago, is still very actively explored with many novel discoveries on its role in various disease models every year. RECENT ADVANCES: The heme oxygenases (HO) are metabolic enzymes that utilize NADPH and oxygen to break apart the heme moiety liberating biliverdin (BV), carbon monoxide (CO), and iron. Heme that is derived from hemoproteins can be toxic to the cells and if not removed immediately, it causes cell apoptosis and local inflammation. Elimination of heme from the milieu enables generation of three products that influences numerous metabolic changes in the cell. CRITICAL ISSUES: CO has profound effects on mitochondria and cellular respiration and other hemoproteins to which it can bind and affect their function, while BV and bilirubin (BR), the substrate and product of BV, reductase, respectively, are potent antioxidants. Sequestration of iron into ferritin and its recycling in the tissues is a part of the homeodynamic processes that control oxidation-reduction in cellular metabolism. Further, heme is an important component of a number of metabolic enzymes, and, therefore, HO-1 plays an important role in the modulation of cellular bioenergetics. FUTURE DIRECTIONS: In this review, we describe the cross-talk between heme oxygenase-1 (HO-1) and its products with other metabolic pathways. HO-1, which we have labeled Nike, the goddess who personified victory, dictates triumph over pathophysiologic conditions, including diabetes, ischemia, and cancer.
Assuntos
Heme Oxigenase-1/fisiologia , Animais , Vias Biossintéticas , Monóxido de Carbono/fisiologia , Respiração Celular , Diabetes Mellitus/enzimologia , Heme/metabolismo , Hemeproteínas/metabolismo , Humanos , Ferro/metabolismo , Mitocôndrias/metabolismo , Neoplasias/enzimologiaRESUMO
Renal insults are considered a public health problem and are linked to increased rates of morbidity and mortality worldwide. The heme oxygenase (HO) system consists of evolutionary specialized machinery that degrades free heme and produces carbon monoxide, biliverdin and free iron. In this sense, the inducible isoform HO-1 seems to develop an important role and is widely studied. The reaction involved with the HO-1 molecule provides protection to injured tissue, directly by reducing the toxic heme molecule and indirectly by the release of its byproducts. The up regulation of HO-1 enzyme has largely been described as providing antioxidant, antiapoptotic, anti-inflammatory and immunomodulatory properties. Several works have explored the importance of HO-1 in renal diseases and they have provided consistent evidence that its overexpression has beneficial effects in such injuries. So, in this review we will focus on the role of HO-1 in kidney insults, exploring the protective effects of its up regulation and the enhanced deleterious effects of its inhibition or gene deletion.