Cell type-specific roles of NLRP3, inflammasome-dependent and -independent, in host defense, sterile necroinflammation, tissue repair, and fibrosis.

The NLRP3 inflammasome transforms a wide variety of infectious and non-infectious danger signals that activate pro-inflammatory caspases, which promote the secretion of IL-1ß and IL-18, and pyroptosis, a pro-inflammatory form of cell necrosis. Most published evidence documents the presence and importance of the NLRP3 inflammasome in monocytes, macrophages, and neutrophils during host defense and sterile forms of inflammation. In contrast, in numerous unbiased data sets, NLRP3 inflammasome-related transcripts are absent in non-immune cells. However, an increasing number of studies report the presence and functionality of the NLRP3 inflammasome in almost every cell type. Here, we take a closer look at the reported cell type-specific expression of the NLRP3 inflammasome components, review the reported inflammasome-dependent and -independent functions, and discuss possible explanations for this discrepancy.

Macrophages mobilized by the overexpression of the macrophage-colony stimulating factor promote efficient recovery of the ischemic muscle functionality.

AIMS: Narrowing or occlusion of arteries that supply the limbs can evolve to critical limb ischemia. M-CSF promotes proliferation, differentiation and survival of monocytes and macrophages, and polarization of macrophages to M2-subtype, which are essential elements for vessel formation and tissue repair. Based on these properties of M-CSF, we hypothesize that transfection of M-CSF into ischemic limbs may promote vessel formation and repair of ischemic limbs. MAIN METHODS: Hindlimb ischemia was surgically induced in 10-12 weeks old Balb/c and gene therapy was performed with intramuscular application of either uP-MCSF or uP plasmids (100 µg). Macrophage and monocyte subpopulations were assessed by flow cytometry and blood flow was monitored by Laser Doppler Perfusion Imaging (LDPI). Thirty days after transfection, we assessed gastrocnemius mass and muscle force, subsequently collecting the muscle for histology. KEY FINDINGS: We successfully developed the uP-MCSF plasmid, which increases M-CSF expression in the muscle transiently. Thirty days after uP-MCSF gene therapy in ischemic muscles, the treated group presented: improved muscle force, reduced fibrosis and increased arteriogenesis, although LDPI analysis did not show any significant difference in blood flow among groups. Noteworthy, we observed a temporary increase in MHCIIhighCD206high macrophages after uP-MCSF transfection. SIGNIFICANCE: M-CSF gene therapy improved ischemic muscle functionality by promoting arteriogenesis and decreasing fibrosis, likely through increased MHCIIhighCD206high macrophages and not via classically known M2-macrophages.

Skeletal muscle healing by M1-like macrophages produced by transient expression of exogenous GM-CSF.

BACKGROUND: After traumatic skeletal muscle injury, muscle healing is often incomplete and produces extensive fibrosis. The sequence of M1 and M2 macrophage accumulation and the duration of each subtype in the injured area may help to direct the relative extent of fibrogenesis and myogenesis during healing. We hypothesized that increasing the number of M1 macrophages early after traumatic muscle injury would produce more cellular and molecular substrates for myogenesis and fewer substrates for fibrosis, leading to better muscle healing. METHODS: To test this hypothesis, we transfected skeletal muscle with a plasmid vector to transiently express GM-CSF shortly after injury to drive the polarization of macrophages towards the M1 subset. C57BL/6 mouse tibialis anterior (TA) muscles were injured by contusion and electroporated with uP-mGM, which is a plasmid vector that transiently expresses GM-CSF. Myogenesis, angiogenesis, and fibrosis were evaluated by histology, immunohistochemistry, and RT-qPCR; subpopulations of macrophages by flow cytometry; and muscle functioning by the maximum running speed on the treadmill and the recovery of muscle mass. RESULTS: Muscle injury increased the number of local M1-like macrophages and decreased the number of M2-like macrophages on day 4, and uP-mGM treatment enhanced this variation. uP-mGM treatment decreased TGF-ß1 protein expression on day 4, and the Sirius Red-positive area decreased from 35.93 ± 15.45% (no treatment) to 2.9% ± 6.5% (p < 0.01) on day 30. uP-mGM electroporation also increased Hgf, Hif1α, and Mtor gene expression; arteriole density; and muscle fiber number during regeneration. The improvement in the quality of the muscle tissue after treatment with uP-mGM affected the increase in the TA muscle mass and the maximum running speed on a treadmill. CONCLUSION: Collectively, our data show that increasing the number of M1-like macrophages immediately after traumatic muscle injury promotes muscle recovery with less fibrosis, and this can be achieved by the transient expression of GM-CSF.

Gut Microbiota and Intestinal Epithelial Myd88 Signaling Are Crucial for Renal Injury in UUO Mice.

Increasing evidence shows the essential participation of gut microbiota in human health and diseases by shaping local and systemic immunity. Despite an accumulating body of studies showing that chronic kidney disease (CKD) is closely associated with disturbances in the composition of gut microbiota, it remains unclear the importance of gut microbiota in the onset and development of CKD. For the purpose of untangling the role of gut microbiota in CKD, gut microbiota was depleted with a pool of broad-spectrum antibiotics in mice submitted to unilateral ureteral obstruction (UUO). Depletion of gut microbiota significantly decreased levels of proinflammatory cytokines and fibrosis markers, attenuating renal injury. Additionally, to study whether the pathogenic role of gut microbiota is dependent of microbial-host crosstalk, we generated mice lacking Myd88 (myeloid differentiation primary response gene 8) expression in intestinal epithelial cells (IECs) and performed UUO. The absence of Myd88 in IECs prevented a bacterial burden in mesenteric lymph nodes as observed in WT mice after UUO and led to lower expression of proinflammatory cytokines and chemokines, reducing deposition of type I collagen and, ultimately, attenuating renal damage. Therefore, our results suggest that the presence of gut microbiota is crucial for the development of CKD and may be dependent of Myd88 signaling in IECs, which appears to be essential to maturation of immune cells intimately involved in aggravation of inflammatory scenarios.

Avaliação das informações sobre síndrome de Down na internet brasileira / Evaluation of information about Down syndrome in brazilian internet / La información sobre el síndrome de Down en internet brasileño

A forma mais utilizada de buscar informações sobre a síndrome de Down é pela internet, ocorrendo 41.000 vezes/mês no Google. Diante disso, objetivou-se avaliar a qualidade, a exatidão das informações e os princípios éticos das páginas da internet brasileira (PIB) sobre síndrome de Down. Avaliaram-se 223 resultados dos buscadores: Google, Yahoo e Bing, em janeiro de 2014, baseando-se nos critérios do Manual de Princípios Éticos para Sites de Medicina e Saúde (MPESMS) do Conselho Regional de Medicina do Estado de São Paulo (CREMESP). Observou-se que: 30,50% possuíram fins de serviços; 28,32%, educativos; 20,92%, publicitários e 20,26%, comerciais. Apenas 22,86% das PIB apresentaram referências bibliográficas e apenas 1,79% tinha profissional com registro em algum conselho de classe. Concluiu-se que as PIB avaliadas relacionados ao tema ?Síndrome de Down? divulgaram conteúdo insuficiente quanto à qualidade da informação, não disponibilizando informações confiáveis aos profissionais da saúde e usuários da internet interessados no tema...

The most used way of researching information on Down syndrome is by internet , occurring 41,000 time /month on Google. Therefore, we aimed to evaluate the quality, accuracy of information and the ethical principles of the Brazilian Internet pages (PIB) on down syndrome. We evaluated 223 search engine results form: Google , Yahoo and Bing , in January 2014 , based on the criteria of the Manual de Princípios Éticos para Sites de Medicina e Saúde (MPESMS) from Conselho Regional de Medicina do Estado de São Paulo (CREMESP). It was observed that: 30.50% owned purposes of services, 28.32% educational, 20.92% advertisements and 20.26% commercials. Only 22.86% PIB had references and 1.79% showed professional with record any class council. It was concluded that the PIB evaluated related to the theme ?Down syndrome? reported insufficient content and quality of information , not providing reliable information to health professionals and Internet users interested in the topic...

La forma más utilizada de la búsqueda de información sobre el síndrome de Down, trastorno genético que causa retraso mental, es la Internet, que se producen 41.000 veces / mes en Google. Por lo tanto, el objetivo fue evaluar la calidad, la exactitud de la información y los principios éticos de las páginas de Internet de Brasil (PIB) en el síndrome de down. Se evaluaron 223 resultados de los motores de búsqueda: Google, Yahoo y Bing, en enero de 2014, con base en los criterios del Manual de Princípios Éticos para Sites de Medicina e Saúde (MPESMS) del Consejo Regional de Medicina de São Paulo (CREMESP). Se observó que: propósitos 30,50% propiedad de los servicios, 28,32%, 20,92%, educativo, 20.26% y anuncios, anuncios publicitarios. El fundamento científico apareció en 23.76%, 48.53%, seguido los estándares de privacidad, 22.86% tienen referencias y sólo 1.79% tienen a profesional con cualquie consejo de clase. Menos del 1% de las páginas estaban en el cumplimiento de todos los criterios evaluados. Se concluyó que el PIB evaluado en relación con el tema ?Síndrome de Down?, informó insuficiente contenido y la calidad de la información, no proporcionar información fiable a los profesionales y usuarios de Internet interesados en el tema...