CD301b+ macrophage: the new booster for activating bone regeneration in periodontitis treatment / 国际口腔科学杂志·英文版

Periodontal bone regeneration is a major challenge in the treatment of periodontitis. Currently the main obstacle is the difficulty of restoring the regenerative vitality of periodontal osteoblast lineages suppressed by inflammation, via conventional treatment. CD301b+ macrophages were recently identified as a subpopulation that is characteristic of a regenerative environment, but their role in periodontal bone repair has not been reported. The current study indicates that CD301b+ macrophages may be a constituent component of periodontal bone repair, and that they are devoted to bone formation in the resolving phase of periodontitis. Transcriptome sequencing suggested that CD301b+ macrophages could positively regulate osteogenesis-related processes. In vitro, CD301b+ macrophages could be induced by interleukin 4 (IL-4) unless proinflammatory cytokines such as interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) were present. Mechanistically, CD301b+ macrophages promoted osteoblast differentiation via insulin-like growth factor 1 (IGF-1)/thymoma viral proto-oncogene 1 (Akt)/mammalian target of rapamycin (mTOR) signaling. An osteogenic inducible nano-capsule (OINC) consisting of a gold nanocage loaded with IL-4 as the "core" and mouse neutrophil membrane as the "shell" was designed. When injected into periodontal tissue, OINCs first absorbed proinflammatory cytokines in inflamed periodontal tissue, then released IL-4 controlled by far-red irradiation. These events collectively promoted CD301b+ macrophage enrichment, which further boosted periodontal bone regeneration. The current study highlights the osteoinductive role of CD301b+ macrophages, and suggests a CD301b+ macrophage-targeted induction strategy based on biomimetic nano-capsules for improved therapeutic efficacy, which may also provide a potential therapeutic target and strategy for other inflammatory bone diseases.

The role of macrophage polarization and interaction with renal tubular epithelial cells in ischemia-reperfusion induced acute kidney injury / 生理学报

Acute kidney injury (AKI) is a common critical clinical disease characterized by a sharp decline of renal function. Ischemia-reperfusion (IR) is one of the main causes of AKI. The mortality of AKI remains high due to the lack of early diagnosis and cause specific treatment. IR rapidly initiates innate immune responses, activates complement and innate immune cells, releasing a large number of injury-related molecules such as high mobility group box-1 (HMGB1), inflammatory mediators such as caspase-3, and then recruits immune inflammatory cells including M1 macrophages (Mϕ) to the microenvironment of injury, causing apoptosis and necrosis of renal tubular epithelial cells (TECs). Dead cells and associated inflammation further activate the adaptive immune system, which not only aggravates tissue damage, but also initiates M2 Mϕ participated inflammatory clearance, tissue repair and regeneration. Mϕ, professional phagocytes, and TECs, semi-professional phagocytes, can phagocytose around damaged cells including apoptotic Mϕ and TECs, which are key innate immune cells to regulate the outcome of injury, repair or fibrosis. In recent years, it has been found that erythropoietin (EPO) not only binds to the homodimeric receptor (EPOR)2 to induce erythropoiesis, but also binds to the heterodimeric receptor EPOR/βcR, also known as innate repair receptor, which plays renoprotective roles. Properdin is the only positive regulator in the complement activation of alternative pathway. It also can effectively identify and bind to early apoptotic T cells and facilitate phagocytic clearing by Mϕ through a non-complement activation-dependent mechanism. Our previous studies have shown that Mϕ and TECs associated with EPO and its receptors and properdin are involved in IR injury and repair, but the underlying mechanism needs to be further explored. As an important carrier of cell-to-cell signal transmission, exosomes participate in the occurrence and development of a variety of renal diseases. The role of exosomes involved in the interaction between Mϕ and TECs in IR-induced AKI is not fully defined. Based on the available results in the role of Mϕ and TECs in renal IR-induced AKI, this review discussed the role of Mϕ polarization and interaction with TECs in renal IR injury, as well as the participation of EPO and its receptors, properdin and exosomes.

Metabotropic glutamate receptor 5 may be involved in macrophage plasticity

Abstract Background Macrophages are a functionally heterogeneous cell population and depending on microenvironments they polarize in two main groups: M1 and M2. Glutamic acid and glutamate receptors may participate in the regulation of macrophage plasticity. To investigate the role of glutamatergic systems in macrophages physiology, we performed the transfection of mGluR5 cDNAs into RAW-264.7 cells. Results Comparative analysis of modified (RAW-mGluR5 macrophages) and non-modified macrophages (RAW-macrophages) has shown that the RAW-mGluR5 macrophages absorbed more glutamate than control cells and the amount of intracellular glutamate correlated with the expression of excitatory amino acid transporters -2 (EAAT-2). Besides, our results have shown that RAW-mGluR5 macrophages expressed a higher level of peroxisome proliferator-activated receptor γ (PPAR-γ) and secreted more IL-10, high mobility group box 1 proteins (HMGB1) and Galectin-3 than control RAW-macrophages. Conclusions We propose that elevation of intracellular glutamate and expression of mGluR5 may initiate the metabolic rearrangement in macrophages that could contribute to the formation of an immunosuppressive phenotype.

Vascular calcification in atherosclerosis: potential roles of macrophages and non-coding micro-RNAs / Calcificación vascular en aterosclerosis: posibles funciones de macrófagos y micro-ARNs no codificantes

Coronary heart disease, a leading cause of death in western societies, is caused by the presence of atherosclerotic plaques in the coronary arteries. Calcification is a frequent complication of atherosclerotic plaques, and often a contributing factor to their instability and rupture. Endothelial cells, smooth muscle cells and plaque macrophages, all contribute to the calcification process, which is reminiscent of that underlying bone formation. In particular, the role of macrophages in calcification has long been recognized, but whether or not distinct macrophage subsets ­v.g., M1 or inflammatory, and M2 or antinflammatory have specific functions in osteogenic signaling within the context of plaque calcification remains poorly understood. Over the past few years, accumulated evidence has revealed novel roles of non-coding micro-RNAs (miRs) in atherorelevant functions of macrophages and in mechanisms linked to macrophage divergence into different subtypes. In this article we discuss some salient findings on potential roles of miRs in vascular calcification, with focus on those miRs that have also been associated to macrophage differentiation, and speculate on their potential relation to M1 and M2 macrophages in the context of calcification of atherosclerotic plaques. (AU)

La enfermedad cardíaca coronaria, principal causa de muerte en occidente, es causada por la presencia de placas ateroscleróticas en las arterias coronarias. La presencia de depósitos de calcificación es una complicación frecuente de la placa, y puede contribuir a la inestabilidad y ruptura de la misma. El proceso de calcificación de la placa es similar al que ocurre en hueso, y contribuyen al mismo, mecanismos dependientes de células endoteliales, células musculares lisas y macrófagos, células que están presentes en todas las etapas de desarrollo de la placa aterosclerótica. El rol de los macrófagos en la calcificación de la placa se conoce desde hace tiempo, pero la contribución de los distintos tipos de macrófagos ­por ejemplo, M1 o tipo inflamatorio, y M2 o tipo antiinflamatorio a mecanismos de señalización osteogénica en dicho contexto aún no se conoce. Recientemente varios trabajos experimentales han revelado la existencia de nuevos roles de micro-ARNs no codificantes (miRs) en varias funciones de los macrófagos que son de relevancia en el proceso aterogénico, como así también en mecanismos relacionados a la diferenciación de macrófagos en subtipos específicos. En este artículo discutimos algunos de los hallazgos más importantes sobre posibles nuevos roles de miRs en calcificación vascular, poniendo énfasis en aquellos miRs que han sido también asociados a la diferenciación de macrófagos, y especulamos acerca de su posible relación con macrófagos M1 y M2 en el contexto de la calcificación de la placa aterosclerótica. (AU)

Estudo da capacidade fagocítica de macrófagos humanos frente a diferentes cepas de Enterococcus faecalis / Study of phagocytic ability of human macrophages against different strains of Enterococcus faecalis

Enterococcus faecalis (E. faecalis) é um microrganismo presente em lesões endodônticas persistentes, mostrando maior resistência do que outras bactérias ao Hidróxido de Cálcio, um medicamento alcalino que consegue eliminar diversos microrganismos durante o tratamento endodôntico. Assim, os objetivos desse estudo foram: (a) avaliar a resposta de E. faecalis isolados de canal radicular, após estresse alcalino, quanto sobrevivência, crescimento, alteração do pH, resistência/susceptibilidade antimicrobiana e formação de biofilme sobre discos de dentina; (b) avaliar a capacidade fagocítica e produção de óxido nítrico (NO) por macrófagos humanos, frente a bactérias E. faecalis de canais radiculares, submetidas a estresse alcalino; (c) avaliar a expressão de TLR2 e CD14 na superfície dos macrófagos desafiados com as diferentes cepas bacterianas. As cepas utilizadas foram: ATCC4083 (CANAL 1) e uma cepa clínica, obtida por nós, a partir de uma lesão endodôntica primária (CANAL 2), ambas isoladas de canais radiculares; e ATCC29212 isolada de urina (URINA), utilizada como controle. O estresse alcalino foi obtido através da inoculação das bactérias em meio BHIalcalino por 4, 24, 48 e 72 horas. As bactérias alcalino-resistentes foram semeadas em ágar, com ou sem troca do meio, e quantificadas por CFU/mL. A susceptibilidade antimicrobiana das diferentes cepas, estressadas ou não (controle), foi determinada pelo Etest; e o biovolume do biofilme foi quantificado microscopicamente. Para avaliar a capacidade fagocítica, macrófagos obtidos a partir de monócitos do sangue periférico foram desafiados com as diferentes cepas, estressadas ou não em meio BHI-alcalino, por 30 minutos, na proporção 5:1 (bactéria/macrófago), e corados com Laranja de Acridina. Foi contado o total de macrófagos com bactérias internalizadas, considerando o número de bactérias internalizadas por célula (<5 e =5). A concentração de NO foi medida em sobrenadantes, através da reação de Griess, e a expressão de TLR2 e CD14 pelos macrófagos foi analisada por citometria de fluxo. Os resultados revelaram que Enterococcus oriundos de canal radicular foram menos resistentes ao estresse alcalino e mais susceptíveis aos antibióticos testados, do que as bactérias oriundas de urina. A falta de nutrientes foi um fator determinante para o crescimento bacteriano de todas as cepas. O biovolume dos biofilmes foi semelhante para todas as cepas estudadas, e não foi alterado após exposição ao BHI-alcalino. Na presença de bactérias submetidas ao estresse alcalino, houve um menor número de macrófagos com bactérias internalizadas, em comparação ao controle. No entanto, a produção de NO e a expressão de TLR2 e CD14 não foram alteradas. Independentemente da cepa utilizada e da presença de estresse alcalino, a maioria dos macrófagos apresentavam-se com =5 bactérias internalizadas por célula. Na ausência de estresse, as cepas de urina resultaram em maior produção de NO que aquelas oriundas do canal radicular; entretanto, a produção deste gás foi semelhante entre as cepas após estresse alcalino. A partir desses resultados, podemos concluir que bactérias E. faecalis de urina diferem daquelas oriundas do canal radicular, principalmente quanto a susceptibilidade/resistência microbiana; assim sugerimos que estudos envolvendo o campo da Endodontia devam ser realizados com cepas oriundas de canal radicular, preferencialmente que de urina. Concluiu-se ainda que um ambiente alcalino associado a falta de nutrientes pode reduzir o crescimento de E. faecalis. Adicionalmente, o estresse alcalino pode levar a alterações na estrutura da parede de E. faecalis, o que dificulta o seu reconhecimento, reduzindo sua fagocitose, mas não a sua capacidade de ativar a produção de NO, pelos macrófagos. Assim, uma medicação intracanal a base de hidróxido de cálcio associada a restaurações coronais muito bem adaptadas, para se evitar infiltração, é fundamental em tratamentos endodônticos. No entanto, os efeitos do estresse alcalino, nos Enterococcus alcalino-resistentes, podem prejudicar sua fagocitose, contribuindo para sua persistência na doença endodôntica.(AU)

Enterococcus faecalis (E. faecalis) is an microorganism present in persistent endodontic lesions, with greater resistance than other bacteria to the calcium hydroxide, an alkaline intracanal dressing which eliminate several bacterial species during endodontic treatment. The objectives of this study were: (a) to evaluate the response of E. faecalis, isolated from root canal, under alkaline-stress, starvation, antimicrobial resistance/susceptibility and biofilm formation on dentin disks; (b) to evaluate the phagocytic ability and the nitric oxide (NO) concentration of human macrophages against root canal E. faecalis isolates submitted to alkaline stress; (c) to evaluate the intensity of TLR2 and CD14 expression on the surface of macrophages challenged with the different bacterial strains. The bacterial strains used were: ATCC 4083 (CANAL 1) and a clinical strain, obtained by us, from a primary endodontic lesion (CANAL 2), both isolated from pulpless teeth; and ATCC29212, isolated from urine (URINE), was a reference for comparison. All strains were inoculated in alkaline-BHI broth for 4, 24, 48 and 72 hours. The alkalineresistant bacteria were seeded in agar and quantified by CFU/mL. Antimicrobial susceptibility of bacterial strains, stressed or not (control) was determined by the Etest and the biovolume after biofilm formation was quantified by microscopy. To evaluate the phagocytic ability, macrophages obtained by culture of peripheral blood monocyte, were challenged with bacterial strains, stressed or not in BHI-alkaline for 30 minutes at 5:1 ratio (bacteria/macrophages) and stained with Acridine Orange. The total of macrophages with internalized bacteria and also the number of internalized bacteria per cell (<5 and =5) were counted. The NO concentration in the supernatants was measured by Griess reaction and the intensity of TLR2 and CD14 expression on the surface of macrophages was also analyzed by flow cytometry. Results shows less resistance to alkaline stress in root canal strains and less resistance to tested antibiotics when compared with urine enterococci. The lack of nutrient was a determining factor for the bacterial growth in all enterococci strains. The biovolume of biofilm formed by all strains were similar, and were not altered after exposure to an alkaline-BHI. In the presence of alkaline-stressed bacteria, there was a smaller number of macrophages with internalized bacteria, when compared to the control. The NO production or the TLR2 and CD14 expression were not altered. Regardless of the strain or alkaline environment, the number of macrophages that showed =5 internalized bacteria per cell was higher. Without an alkaline-stress the NO production results higher in the urine strain, when compared with the root canal strains, however, was not modificated after the exposure of bacteria to alkalinestress. We conclude that root-canal strains have different features when compared with urine enterococci, with the main differences being evident in their resistance/susceptibility to antibiotics; thus, we suggest that researches with aims directed to interpreting responses to endodontic treatment should be conducted with strains from root-canals. Besides, an alkaline environment associated to a starvation condition can reduce bacterial growth. Additionally, alterations in the structure of bacterial cell wall after alkali-stressing possibly made their recognition difficult, reducing their ability to be phagocytized, but not their ability to activate NO production. Therefore, intracanal medication with calcium hidroxyde dressing and coronal restorations, to prevent infiltration, should be critical in treatments of endodontics infections. However, the impact of alkaline stress, in alkaline-resistant enterococci, can impair the phagocytosis, contributing to their persistence in endodontic disease.(AU)

Phagocytic function of lower spleen pole and autogenous splenic implants in rats

PURPOSE: To investigate whether there are differences between the phagocytic function of the remaining lower spleen pole after subtotal splenectomy and autogenous splenic implants. METHODS: Thirty-six male Wistar rats, weighting 364 ± 60g were used. They were subjected to subtotal splenectomy preserving the lower spleen pole and to autogenous splenic implant in the greater omentum. Its viability was assessed microscopically. Phagocytic function was assessed by splenic uptake of the radioisotope-labeled colloid and by macrophages counting. RESULTS: The viability of the autogenous splenic implant and of the lower spleen pole was found in 33 animals, with no difference between them. The weight of the implants was higher than the lower pole of animals from groups G1, G7, G30, G60 and G120. The implants phagocytic function by radioisotope uptake was higher than the lower pole in G7 and G120 groups and it did not differ from the other groups. The number of macrophages was higher in G1, G60, G90 and G120 and did not differ from the other groups. CONCLUSION: Until the 16th week, the phagocytic function was more pronounced in autogenous splenic implants when compared with the lower spleen pole, but it became similar thereafter. .

Preventive effect of Ligularia fischeri on inhibition of nitric oxide in lipopolysaccharide-stimulated RAW 264. 7 macrophages depending on cooking method

BACKGROUND: Ligularia fischeri (common name Gomchwi) is known for its pharmaceutical properties and used in the treatment of jaundice, scarlet-fever, rheumatoidal arthritis, and hepatic diseases; however, little is known about its anti-inflammatory effect. In this study the influence of blanching and pan-frying on the anti-inflammatory activity of Ligularia fischeri (LF) was evaluated. RESULTS: Fresh LF and cooked LF showed no significant effect on the viability of macrophages after 24 h incubation. Fresh LF was found to be the most potent inhibitor of nitric oxide (NO) production at 100 µg/ml, while pan-fried LF showed little inhibitory effect on lipoloysaccharide (LPS) stimulated murine machrophage RAW264.7 cells. In contrast with its effect on NO production, pan-fried LF showed significant attenuation of the expression of inducible nitiric oxide synthase (iNOS) compared with fresh LF. In the cooking method of LF, PGE2 production was not affected in the LPS-induced RAW 264.7 cells. In LPS-induced RAW 264.7 cells, pretreatment by fresh and cooked LF increased COX2 mRNA expression. The 3-O-caffeoylquinic acid content of blanching and pan-frying LF increased by 4.92 and 9.7 fold with blanching and pan-frying respectively in comparison with uncooked LF. CONCLUSIONS: Regardless of the cooking method, Ligularia fischeri exhibited potent inhibition of NO production through expression of iNOS in LPS-induced RAW264.7 cells.

¿Es la hipertensión sensible a sal una enfermedad inflamatoria?: Papel de los linfocitos y macrófagos / Is salt sensitive hypertension an inflammatory disease?: Role of lymphocytes and macrophages

La hipertensión arterial sistémica es un problema de salud pública. Esta entidad afecta al 43% de la población mexicana y es considerada una de los principales factores de riesgo para el desarrollo de eventos vasculares cerebrales, insuficiencia cardiaca e insuficiencia renal. La prevalencia de hipertensión arterial sistémica se ha incrementado durante las últimas décadas debido a la adopción de una dieta alta en sal. Existe evidencia de que la hipertensión sensible a sal se acompaña de alteraciones estructurales renales como dilatación tubular, fibrosis intersticial en parches, expresión de osteopontina e infiltrado túbulo intersticial de linfocitos y macrófagos, que impiden una excreción urinaria de sodio adecuada y en consecuencia, favorecen el desarrollo de HAS. De forma experimental se ha demostrado que estas alteraciones estructurales tienen una naturaleza inflamatoria y que la administración de medicamentos inmunosupresores disminuye la lesión tisular y mejoran el control de la presión arterial. En conjunto, los conocimientos derivados de los estudios de hipertensión sensible a sal pueden derivar en el desarrollo de nuevos fármacos destinados a mejorar el pronóstico asociado a la hipertensión arterial sistémica.

High blood pressure is a public health problem. This entity affects 43% of the mexican population and is considered a major risk factor for development of stroke, cardiac failure and chronic kidney disease. Hypertension prevalence has increased over the last decades, mainly because of high salt diet. There is evidence showing that salt-sensitive hypertension develops structural changes as tubular dilation, patchy interstitial fibrosis, osteopontin expression and lymphocytic/macrophage tubulointerstitial infiltrate that blunts urinary sodium excretion and therefore promotes HBP. It has been shown that this structural damage has an inflammatory origin and that immunosuppresant drugs down-regulates tissular injury and improves blood pressure control. In summary, this salt-sentitive hypertension data can be used in development of new and potent blood pressure drugs.

M2-polarized macrophages promote metastatic behavior of Lewis lung carcinoma cells by inducing vascular endothelial growth factor-C expression

OBJECTIVES: Tumor-associated macrophages that generally exhibit an alternatively activated (M2) phenotype have been linked to tumor progression and metastasis. However, the role of M2-polarized macrophages in the growth and metastasis of lung adenocarcinoma remains enigmatic. The aim of this study was to explore the effect of M2 macrophages on the proliferation and migration of mouse Lewis lung carcinoma cells and tumor-induced lymphangiogenesis. METHODS: Trypan blue staining and the Transwell migration assay were performed to evaluate the effects of activated (M1 or M2) macrophages on the proliferation and migration of Lewis cells. Furthermore, vascular endothelial growth factor-C expression in Lewis cells and nitric oxide secretion from activated macrophages were detected during the co-culture assay. Following treatment with activated macrophages, lymphatic endothelial cells differentiated into capillary-like structures, and the induction of Lewis cell migration was assessed using a twodimensional Matrigel-based assay. RESULTS: In the co-culture Transwell system, the proliferation and migration of Lewis cells were promoted by M2 macrophages. Moreover, the co-culture significantly increased the expression of vascular endothelial growth factor-C by Lewis cells and reduced the secretion of nitric oxide from M2 macrophages, which subsequently led to the capillary morphogenesis of lymphatic endothelial cells. Interestingly, following co-culture with Lewis cells, the function of RAW264.7 cells was polarized toward that of the M2 macrophage phenotype. CONCLUSION: M2-polarized macrophages promoted the metastatic behavior of Lewis cells by inducing vascular endothelial growth factor-C expression. Thus, the interruption of signaling between M2 macrophages and Lewis cells may be considered to be a new therapeutic strategy.

Renal macrophage infiltration is associated with a poor outcome in IgA nephropathy

OBJECTIVES: The objectives of our study were as follows: 1) to analyze the prognostic value of macrophage infiltration in primary IgA nephropathy (IgAN) and 2) to study the relationship between macrophages and other factors associated with the development of renal fibrosis, including mast cells, TGF-β1, α-SMA and NF-kB. METHODS: We analyzed 62 patients who had been diagnosed with IgAN between 1987 and 2003. Immunohistochemical staining was performed with monoclonal antibodies against CD68 and mast cell tryptase and polyclonal antibodies against TGF-β1, α-SMA and NF-kB p65. We also used Southwestern histochemistry for the in situ detection of activated NF-kB. RESULTS: The infiltration of macrophages into the tubulointerstitial compartment correlated with unfavorable clinical and histological parameters, and a worse clinical course of IgAN was significantly associated with the number of tubulointerstitial macrophages. Kaplan-Meier curves demonstrated that increased macrophage infiltration was associated with decreased renal survival. Moreover, the presence of macrophages was associated with mast cells, tubulointerstitial α-SMA expression and NF-kB activation (IH and Southwestern histochemistry). In the multivariate analysis, the two parameters that correlated with macrophage infiltration, proteinuria and tubulointerstitial injury, were independently associated with an unfavorable clinical course. CONCLUSION: An increased number of macrophages in the tubulointerstitial area may serve as a predictive factor for poor prognosis in patients with IgAN, and these cells were also associated with the expression of pro-fibrotic factors.

Alterações histológicas em fígados e linfonodos de búfalos (bubalus bubalis) mantidos em pastagens de brachiaria spp / Histologic lesions in livers and lymph nodes in buffalo (bubalus bubalis) grazing in brachiaria spp. pastures

Infiltração por macrófagos espumosos e outras lesões podem ser encontradas em bovinos clinicamente sadios em pastagens de Brachiaria spp. Com o objetivo de determinar as alterações histológicas do fígado e linfonodos mesentéricos em búfalos no Pará foram estudadas as alterações histológicas de fragmentos desses órgãos de 142 búfalos da raça Murrah e de 15 bovinos da raça Nelore, coletados em frigoríficos. As coletas foram separadas em grupos de animais de acordo com sua origem e tempo de permanência na pastagem de Brachiaria spp., sendo o Grupo (G) 1 composto por 79 búfalos provenientes da Ilha de Marajó, criados em pastagens de campo nativo; o G2 composto por 17 búfalos mantidos desde o nascimento em pastagens de Brachiaria brizantha; o G3 composto por 29 búfalos adquiridos na Ilha do Marajó e introduzidos em pastagem de B. decumbens por aproximadamente 12 meses; o G4 composto por 17 búfalos adquiridos na Ilha de Marajó e introduzidos em pastagem de B. brizantha por aproximadamente 18 meses; e o G5 composto por 15 bovinos mantidos em pastagem de B. brizantha por aproximadamente 12 meses.Para avaliar a gravidade da lesão hepática foram estabelecidos graus de acordo com a quantidade e tamanho dos grupos de macrófagos espumosos, seguindo uma escala de 0 a 4. Nos animais do G1, provenientes da Ilha de Marajó, não foram observadas alterações histológicas significativas no fígado e linfonodos mesentéricos. Em todas as amostras dos grupos G2, G3 e G4 foram observados quantidades variáveis de macrófagos espumosos no fígado e linfonodos mesentéricos.Os animais dos grupos G2 e do G4, que permaneceram um período maior em pastagens de Brachiaria spp, apresentaram lesões mais acentuadas (P<0,05) de macrófagos espumosos do que os animais do G3...

Infiltration by foamy macrophages and other lesions are reported in healthy cattle held in Brachiaria spp. pastures. With the objective to study histologic lesions in the liver and mesenteric lymph nodes in buffalo in the state of Pará, samples of liver and lymph nodes of 142 buffalo Murah and 15 Nelore cattle were studied histologically. The samples were collected in an slaughterhouse and divided into groups of animals according to their origin and period of grazing Brachiaria spp. pastures. Group (G) 1 consisted of 79 buffalo from Marajó Island, raised in native pastures free of Brachiaria spp.; G2 was composed of 17 buffalo kept since birth in Brachiaria brizantha pastures; G3 was composed of 29 buffalo purchased in Marajó Island and introduced in B. decumbens pastures where they stayed for nearly 12 months; G4 consists of 17 buffalo purchased in Marajó Island and introduced in B. brizantha pastures where they stayed for nearly 18 months. G5 was composed of 15 Nelore cattle grazing B. brizantha during one year period. To assess the degree of liver injury, grades following a scale of 0 to 4 were established according to the quantity and size of groups of foamy macrophages. In G1, from the Marajó Island, there were no significant histological changes in liver and lymph nodes. Foamy macrophages and other lesions were observed in liver and lymph nodes of all samples from G1, G2, G3, and G4. The animals from G2 and G4, which remained a longer period in Brachiaria spp., showed more pronounced infiltration of foamy macrophages (P<0.05) than the animals of G3...

Ascorbic acid for the healing of skin wounds in rats / Ácido ascórbico na cicatrização de feridas cutâneas em ratos

BACKGROUND: Healing is a complex process that involves cellular and biochemical events. Several medicines have been used in order to shorten healing time and avoid aesthetic damage. OBJECTIVE: to verify the topical effect of ascorbic acid for the healing of rats' skin wounds through the number of macrophages, new vessels and fibroblast verifications in the experimental period; and analyse the thickness and the collagen fibre organization in the injured tissue. METHODS: Male Rattus norvegicus weighing 270 ± 30 g were used. After thionembutal anesthesia, 15 mm transversal incisions were made in the animals' cervical backs. They were divided into two groups: Control Group (CG, n = 12) - skin wound cleaned with water and soap daily; Treated Group (TG, n = 12) - skin wound cleaned daily and treated with ascorbic acid cream (10 percent). Samples of skin were collected on the 3rd, 7th and 14th days. The sections were stained with hematoxylin-eosin and picrosirius red for morphologic analysis. The images were obtained and analysed by a Digital Analyser System. RESULTS: The ascorbic acid acted on every stage of the healing process. It reduced the number of macrophages, increased the proliferation of fibroblasts and new vessels, and stimulated the synthesis of thicker and more organized collagen fibres in the wounds when compared to CG. CONCLUSION: Ascorbic acid was shown to have anti-inflammatory and healing effects, guaranteeing a suiTable environment and conditions for faster skin repair.

FUNDAMENTOS: A cicatrização é um processo complexo que envolve eventos celulares e bioquímicos. Vários medicamentos têm sido empregados na tentativa de abreviar a cicatrização e evitar danos estéticos. OBJETIVO: verificar o efeito tópico do ácido ascórbico no processo de cicatrização de feridas cutâneas de ratos através da verificação do número de macrófagos, neovasos e fibroblastos presentes no período experimental; e analisar a espessura e a organização das fibras colágenas no tecido lesado. MÉTODOS: Foram utilizados Rattus norvegicus, machos, pesando 270 ± 30 g. Foi realizada incisão transversal na pele da região dorso-cervical de 15 mm de comprimento, após anestesia com Thionembutal. Os animais foram divididos em 2 grupos: grupo controle (GC, n = 12), feridas higienizadas diariamente com água e sabão; grupo tratado (GT, n = 12), feridas higienizadas e tratadas com creme de ácido ascórbico (10 por cento). Os fragmentos para análise histológica foram coletados no 3º, 7º e 14º dia, e as lâminas coradas com hematoxilina-eosina e picrosírius red para análise morfológica. As imagens foram capturadas e analisadas por um sistema digitalizador. RESULTADOS: O ácido ascórbico atuou em todas as etapas da cicatrização, diminuindo o número de macrófagos, aumentando a proliferação dos fibroblastos e neovasos, e favorecendo a deposição de fibras colágenas mais espessas e organizadas nas feridas. CONCLUSÃO: O ácido ascórbico mostrou ter efeito antiinflamatório e cicatrizante, promovendo ambiente e condições favoráveis para a reparação tecidual, o que abreviou o tempo da cicatrização.

Efeito da autofagia sobre a capacidade fagocítica e sobre a infecção de macrófagos de camundongos CBA/J por Leishmania amazonensis / Effect of autophagy on phagocytic capacity and the infection of macrophages from CBA /J mice by Leishmania amazonensis

A autofagia vem sendo alvo de estudos que demonstram sua participação em infecções por diversos patógenos intracelulares. A depender do patógeno, a autofagia pode facilitar a sobrevivência intracelular do patógeno ou pode funcionar como controle da infecção pela célula hospedeira. Pouco se sabe sobre a participação da autofagia na infecção por Leishmanía. Foi demonstrado que o vacúolo parasitóforo induzido por L. mexícana adquire nutrientes citosólicos por microautofagia. Além disso, recentemente foi demonstrado que a indução de autofagia promove aumento da carga parasitária de L. amazonensís em macrófagos infectados. Esses dados sugerem a participação do processo autofágico no estabelecimento da infecção por Leishmanía, como um mecanismo que favorece a sobrevivência intracelular do parasito. Assim, o objetivo desse estudo foi determinar a influência da autofagia na infecção, in vitro, de macrófagos de camundongos CBA/J por L. amazonensís. Macrófagos foram induzidos à autofagia por duas formas, fisiológica ou farmacológica, após ou antes da infecção por L. amazonensís ou exposição a partículas de levedo ou zimosan. O percentual de infecção e de fagocitose foi estimado. Os resultados mostram que a indução de autofagia, após a infecção, não altera o percentual de macrófagos infectados, mas promove o aumento na carga parasitária de macrófagos infectados por L. amazonensís. Além disso, a prévia indução de autofagia promove a inibição da capacidade fagocítica do macrófago murino. Estudos adicionais serão realizados no intuito de esclarecer os mecanismos pelos quais a indução de autofagia favorece a infecção por L. amazonensís e altera a capacidade fagocítica do macrófago murino.

Lactonas sesquiterpénicas de las plantas Viguiera sylvatica y Decachaeta thieleana (Asteraceae) modulan la producción de óxido nítrico y la fagocitosis de macrófagos RAW

Sesquiterpene lactones of the plants Viguiera sylvatica and Decachaeta thieleana (Asteraceae) modulate nitric oxide production and phagocytosis of macrophages cell line RAW. Different species of the Asteraceae family are a potential source of sesquiterpene lactones with anti-inflammatory properties. Macrophages play a central role in the regulation of immune responses. In the present study, the in vitro effect of two sesquiterpene lactones, a millerenolide and a thieleanin, was assessed by measuring the production of nitric oxide (NO) by cell line RAW (murine macrophages) using the Griess reagent. Additionally, the effect of these sesquiterpene lactones on phagocytic capacity of latex particles and the reduction of nitroblue tetrazolium (NBT) were evaluated microscopically. Treatment of macrophages with >2.5 µg/ml of both sesquiterpene lactones, reduced the production of NO. A decreased number of macrophages able to reduce NBT were observed when these cells were treated with 3 µg/ml of millerenolide or 7.5 µg/ml of thieleanin. Treatment of macrophages with 4 µg/ml of millerenolide or 7.5 µg/ml of thieleanin, reduced the phagocytic capacity of macrophages. Cytotoxic effects on the macrophages were only observed when the concentration was increased to 8 µg/ml of millerenolide or 25 µg/ml of thieleanin. Our results suggest that these sesquiterpene lactones could be useful compounds in the elaboration of anti-inflammatory drugs. Rev. Biol. Trop. 56 (3): 1063-1073. Epub 2008 September 30.

Las plantas de la familia Asteraceae son una fuente potencial de lactonas sesquiterpénicas con propiedades antiinflamatorias. Los macrófagos son células que desempeñan una función central en la regulación de la respuesta inmune. Este estudio evaluó el efecto in vitro de dos lactonas sesquiterpénicas, un millerenólido y thieleanina, sobre la producción de óxido nítrico (NO) en una línea celular de macrófagos de ratón (RAW), utilizando el reactivo de Griess. Además, se estudió el efecto sobre la capacidad fagocítica de RAW, evaluando al microscopio la fagocitosis de partículas inertes de látex y la reducción de nitroazul de tetrazolio (NBT). Se observó que los macrófagos tratados con lactona sesquiterpénica (>2.5 µg/ml) disminuyeron la producción de NO. Además, se observó una disminución de la cantidad de macrófagos capaces de reducir NBT, después que fueron tratados con millerenólido (3 µg/ml) o thieleanina (7.5 µg/ ml). Por otro lado, la exposición a 4 µg/ml de millerenólido ó 7.5 µg/ml de thieleanina redujo la cantidad promedio de partículas de látex fagocitadas. No se observaron diferencias entre tratamientos y control en cuanto al porcentaje de células fagocíticas. Sólo se observaron efectos citotóxicos sobre los macrófagos, cuando la concentración de millerenólido se incrementó a 8 µg/ml o la de thieleanina se aumentó a 25 µg/ml. Estos resultados sugieren que el millerenólido y la thieleanina podrían ser compuestos útiles en la elaboración de drogas antiinflamatorias.

Late histological aspects of spleen autologous transplantation in rats / Aspectos histológicos tardios do transplante autólogo de baço em ratos

PURPOSE: To evaluate macro and microscopically the late evolution of autotransplants of fragments of spleen in the greater omentum, mesenterium and peritoneal cavity, after 24 weeks of observation. METHODS: Fifty two Wistar rats were used, males and adults, submitted to total splenectomy and divided in four groups. The group I - seventeen animals with implant of spleen fragment in the peritoneal cavity; group II - eighteen animals with implant in the omentum and group III - seventeen animals with implant fixed in mesenterium root. The group control (group IV) was formed by eight animals chosen aleatorily among the three groups. It was analyzed macro and microscopically the evolution of the implant, and in the histological study qualitative and quantitative criteria were adopted, with the counting of no cellular e cellular elements. RESULTS: It was observed adherences to the adjacent tissues and vascularization in all of the fragments transplanted. The group I presented white pulp and preserved vascularization. In the group II were observed white pulp with follicular formations and lymphoid tissue preserved, and the red pulp in cordon aspect and hemorrhagic. In the group III were observed with depletion of white and red pulp, while others evidenced better preservation of the pulps. The counting of lymphocytes revealed significant difference between the groups I and IV and the group III and IV (p < 0.05). The counting of active macrophages revealed significant difference between the groups II and III (p < 0.05) and similarity between II and IV (p > 0.05). The other elements: active macrophages phagocyting hemosiderine, plasmocytes, fibroblasts, fibrocytes, giant cells, monocytes, interstitial spaces and fibers of collagen, did not show significant difference among the groups. CONCLUSIONS: The splenic autotransplantation is feasible, being the better place the greater omentum. This research demonstrated through qualitative and quantitative...

OBJETIVO: Avaliar macro e microscopicamente a evolução tardia do autotransplante de fragmentos de baço no grande epiplon, mesentério e cavidade peritoneal, após 24 semanas de observação. MÉTODOS: Foram utilizados 52 ratos Wistar, machos e adultos, submetidos a esplenectomia total e divididos em quatro grupos. O grupo I - dezessete animais com implante de fragmento de baço solto na cavidade peritoneal; grupo II - dezoito animais com implante no grande epiplon e grupo III - dezessete animais com implante fixado na raiz do mesentério. O grupo controle (grupo IV) foi formado por oito animais escolhidos aleatoriamente entre os três grupos. Foram analisados macro e microscopicamente a evolução do implante, sendo que no estudo histológico foram adotados critérios qualitativos e quantitativos, com a contagem de elementos celulares e não celulares. RESULTADOS: Foram observadas aderências aos tecidos adjacentes e neovascularização em todos os fragmentos transplantados. O grupo I apresentou polpa branca e vascularização preservada. No grupo II foram observadas polpa branca com formação folicular e bainha linfóide, e a polpa vermelha em aspecto cordonal apesar de hemorrágica. No grupo III foram observados alguns cortes histológicos com depleção de polpa branca e vermelha, enquanto outros evidenciavam melhor preservação das polpas. A contagem de linfócitos revelou diferença significativa entre os grupos I e IV e o grupo III e IV (p<0,05). A contagem de macrófagos ativos revelou diferença significativa entre os grupos II e III (p<0,05) e similaridade entre II e IV (p>0,05). Os outros elementos: macrófagos ativos fagocitando hemossiderina, plasmócitos, fibroblastos, fibrócitos, células gigantes, monócitos, espaços intersticiais e fibras de colágeno, não apresentaram diferença significativa entre os grupos. CONCLUSÕES: O autotransplante esplênico é factível, sendo o grande epiplon o melhor local para a sua fixação. Esta pesquisa demonstrou por meio de...

Macrófagos, inflamación, tejido adiposo, obesidad y resistencia a la insulina / Macrophages, inflammation, adipose tissue, obesity and insulin resistance

La obesidad se asocia con un estado inflamatorio implicado en el desarrollo de aterosclerosis y resistencia a la insulina. Los macrófagos son claves en la génesis de estos procesos. La obesidad induce la acumulación de macrófagos en el tejido adiposo. Los macrófagos producen muchas de las moléculas inflamatorias secretadas por el tejido adiposo. Las proteínas quimioatrayentes de monocitos (MCP) y sus receptores son fundamentales en la respuesta inflamatoria y en el reclutamiento de células inmunes en sitios de inflamación. La expresión en el tejido adiposo de una MCP, la quimiocina del ligando 2 del motif C-C (CCL2 o MCP1), está incrementada en proporción a la adiposidad. El receptor 2 de quimiocina del motif C-C (CCR2) regula el reclutamiento y quimiotaxis de monocitos y macrófagos, es necesario para las respuestas inflamatorias dependientes de macrófagos y para el desarrollo de aterosclerosis. Ya que el receptor CCR2 regula las respuestas inflamatorias locales, se ha postulado que las MCP, actuando a través de su receptor CCR2, podrían regular la inflamación inducida por la obesidad en el tejido adiposo. Este documento se enfoca en dilucidar los mecanismos moleculares y genéticos que permiten reclutar y retener macrófagos en el tejido adiposo.

Obesity is associated with a complex systemic inflammatory reaction that has been associated with the development of atherosclerosis and insulin resistance. Obesity also induces macrophage accumulation in adipose tissue. Macrophages produce many of the pro inflammatory molecules released by adipose tissue and have been implicated in the development of obesity-induced adipose tissue inflammation. Monocyte chemoattractant proteins (MCPs) and their receptors play key roles in the development of inflammatory responses and are crucial for the recruitment of immune cells towards inflammation sites. Adipose tissue expression of at least 1 MCP, C-C motif chemokine ligand-2 (CCL2 or MCP1), increases in proportion to adiposity. The C-C motif chemokine receptor-2 (CCR2) regulates monocyte and macrophage recruitment and is necessary for macrophage-dependent inflammatory responses and the development of atherosclerosis. Because CCR2 regulates monocyte and macrophage chemotaxis and local inflammatory responses, it has been hypothesized that monocyte chemoattractant molecules acting through CCR2 might regulate obesity-induced inflammation in adipose tissue. Our study focuses on the molecular and genetic mechanisms that recruit and retain macrophages in adipose tissue.

Macrophage and dengue virus: friend or foe?

The cells of monocyte-macrophage (Mphi) lineage play important roles both in innate and adaptive immune responses. They are the first line of defence in body and their job is to phagocytose a foreign invader, the pathogen, digest it and remove it. Mphi help body in mounting the antigenspecific immune response by presenting the digested pathogen antigen in conjunction with major histocompatibility complex (MHC) class II molecules to recruit B and T lymphocytes response. Usually Mphi succeed in their job of eliminating most pathogens from the body but sometimes the pathogen strikes a "friendship" with them and starts using them for its benefit. A number of pathogens, including dengue virus (DV), subvert Mphi and use them for their replication, increasing the severity of damage to the body. This duality may be related to the fact that Mphi serve as efficient host cell for DV replication, in addition to being responsible for innate immunity and for initiating adaptive immune responses. This review gives a brief overview of the various roles of Mphi (enmity and friendship) during dengue virus infection.

Mycobacterium leprae interactions with the host cell: recent advances.

The significance of Hansen disease, or leprosy, is underscored by fact that detection of this disease has remained stable over the past 10 yr, even though disease prevalence is reduced. Due to the long incubation time of the organism, health experts predict that leprosy will be with us for decades to come. Despite the fact that Mycobacterium leprae, the causative agent of leprosy, cannot be cultured in the laboratory, researchers are using innovative and imaginative techniques to discern the interactions of M. leprae with host cells both in vitro and in vivo to identify the host and bacterial factors integral to establishment of disease. The studies described in this review present a new and evolving picture of the many interactions between M. leprae and the host. Specific attention will be given to interactions of M. leprae bacilli with host Schwann cells, macrophages, dendritic cells and endothelial cells. The findings described also have implications for the prevention and treatment of leprosy.

Phenotypic, functional, and quantitative characterization of canine peripheral blood monocyte-derived macrophages

The yield as well as phenotypic and functional parameters of canine peripheral blood monocyte-derived macrophages were analyzed. The cells that remained adherent to Teflon after 10 days of culture had high phagocytic activity when inoculated with Leishmania chagasi. Flow cytometric analysis demonstrated that more than 80 percent of cultured cells were positive for the monocyte/macrophage marker CD14.

Apoptotic mimicry: an altruistic behavior in host/Leishmania interplay

Apoptosis is the most common phenotype observed when cells die through programmed cell death. The morphologic and biochemical changes that characterize apoptotic cells depend on the activation of a diverse set of genes. Apoptosis is essential for multicellular organisms since their development and homeostasis are dependent on extensive cell renewal. In fact, there is strong evidence for the correlation between the emergence of multicellular organisms and apoptosis during evolution. On the other hand, no obvious advantages can be envisaged for unicellular organisms to carry the complex machinery required for programmed cell death. However, accumulating evidence shows that free-living and parasitic protozoa as well as yeasts display apoptotic markers. This phenomenon has been related to altruistic behavior, when a subpopulation of protozoa or yeasts dies by apoptosis, with clear benefits for the entire population. Recently, phosphatidylserine (PS) exposure and its recognition by a specific receptor (PSR) were implicated in the infectivity of amastigote forms of Leishmania, an obligatory vertebrate intramacrophagic parasite, showing for the first time that unicellular organisms use apoptotic features for the establishment and/or maintenance of infection. Here we focus on PS exposure in the outer leaflet of the plasma membrane - an early hallmark of apoptosis - and how it modulates the inflammatory activity of phagocytic cells. We also discuss the possible mechanisms by which PS exposure can define Leishmania survival inside host cells and the evolutionary implications of apoptosis at the unicellular level.