New role of astrocytes in neuroprotective mechanisms after ischemic stroke / Novo papel dos astrócitos nos mecanismos neuroprotetores após acidente vascular cerebral isquêmico

Abstract Astrocytes are the most abundant cell subtypes in the central nervous system. Previous studies believed that astrocytes are supporting cells in the brain, which only provide nutrients for neurons. However, recent studies have found that astrocytes have more crucial and complex functions in the brain, such as neurogenesis, phagocytosis, and ischemic tolerance. After an ischemic stroke, the activated astrocytes can exert neuroprotective or neurotoxic effects through a variety of pathways. In this review, we will discuss the neuroprotective mechanisms of astrocytes in cerebral ischemia, and mainly focus on reactive astrocytosis or glial scar, neurogenesis, phagocytosis, and cerebral ischemic tolerance, for providing new strategies for the clinical treatment of stroke.

Resumo Os astrócitos são os subtipos de células mais abundantes no sistema nervoso central. Estudos anteriores acreditavam que os astrócitos são células de suporte no cérebro, que apenas fornecem nutrientes para os neurônios. No entanto, estudos recentes descobriram que os astrócitos têm funções mais cruciais e complexas no cérebro, como neurogênese, fagocitose e tolerância isquêmica. Após um acidente vascular cerebral isquêmico, os astrócitos ativados podem exercer efeitos neuroprotetores ou neurotóxicos através de uma variedade de vias. Nesta revisão, discutiremos os mecanismos neuroprotetores dos astrócitos na isquemia cerebral, e focaremos principalmente na astrocitose reativa ou cicatriz glial, neurogênese, fagocitose e tolerância isquêmica cerebral, para fornecer novas estratégias para o tratamento clínico do acidente vascular cerebral.

Reaserch progress of microglial phagocytosis in ischemic stroke / 中国药科大学学报

@#Ischemic stroke is a major disease affecting human health, and its pathological mechanism has not been fully elucidated. Microglia are important immune cells in the central nervous system, and participate in the pathological process of ischemic stroke.Following an ischemic stroke, a surge in activated microglia occurs, migrating and congregating within the afflicted regions.These microglia engulf deceased cells or fragments, releasing inflammatory or nutritive factors, thereby participating in the pathogenesis of ischemic stroke.The phagocytosis of microglia plays an important role in cerebral ischemic injury and rehabilitation. This article summarizes the molecular mechanism of microglial phagocytosis and reviews the research progress of microglial phagocytosis in ischemic stroke, and discusses the diversity and complexity of microglial phagocytosis in cerebral ischemic injury and rehabilitation, so as to provide new ideas for the treatment and drug development of ischemic stroke.

Glycan targeting nanoparticle for photodynamic immunotherapy of melanoma

Interaction between tumour cells and macrophages enables cancer cells to evade immune detection and clearance by interfering with macrophage phagocytosis. The anti-phagocytic signals regulated by anti-phagocytic proteins are termed "don't eat me" signals; these signals include sialic acid-binding immunoglobulin-type lectin-10 (Siglec-10) and the recently revealed CD24 immune checkpoint (ICP). In this study, we demonstrate that targeting a specific glycan on CD24 exhibits the potential to inhibit ICP. Sambucus nigra agglutinin (SNA), a sialic acid-binding lectin, was employed to block CD24 and to enhance phagocytosis in melanoma tumours. In addition, we prepared SNA-conjugated hollow gold-iron oxide nanoparticles for photothermal therapy of tumours. Our findings show that the combination treatment of SNA-conjugated photothermal nanoparticles and near-infrared exposure successfully augments tumour cell phagocytosis both in vitro and in vivo models.

Role of LC3-associated phagocytosis in regulating infection / 中华微生物学和免疫学杂志

LC3-associated phagocytosis (LAP) is a special phagocytosis occurring at the intersection of the two pathways of phagocytosis and autophagy. A hallmark event of the LAP process is the recruitment of microtubule-associated proteinⅠlight chain type 3-Ⅱ(LC3Ⅱ) to the phagosome surface of the monolayer membrane structure. The LAP pathway relies on the functions of the RUN domain and cysteine-rich domain containing, Beclin 1-interacting protein (Rubicon) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The LC3-associated phagosome (LAPosome) binds to the lysosome to digest and degrade the contents. In recent years, increasing studies have found that LAP plays an important role in the infections caused by pathogenic microorganisms including fungi and bacteria. LAP is a crucial way in the host to resist and degrade the infection of pathogenic microorganisms. However, some pathogenic microorganisms can effectively escape from LAP in the host and even use LAPosome as a place for colonization and replication. This article summarized the recent progress in the role of LAP in host defense against pathogenic microorganism infection and the significance of it in the occurrence and development of diseases.

Research progress of microglia regulating phagocytosis of apoptotic neurons after intracerebral hemorrhage / 中华神经科杂志

Intracerebral hemorrhage is the bleeding caused by spontaneous non-traumatic rupture of blood vessels in brain parenchyma. It has high disability rate and mortality. A series of injuries after intracerebral hemorrhage will lead to neuronal apoptosis. If apoptotic neurons are not cleared in time, intracellular toxic substances will be released, thereby further aggravating the inflammatory reaction. Therefore, the timely clearance of apoptotic cells is of great significance to the brain homeostasis after intracerebral hemorrhage. At the same time, a large number of phagocytic "eat me" signal phosphatidylserine (PS) will appear on the surface of apoptotic neurons. Microglia, as resident macrophages in the brain, have a variety of PS receptors on their surface, which promote the phagocytosis of apoptotic neurons by microglia and reduce the occurrence of local inflammatory responses.

Effect and mechanism of cytochrome P450 1A1 on regulating phagocytosis of macrophage / 中华危重病急救医学

Objective:To explore the effect and mechanism of cytochrome P450 1A1 (CYP1A1) on regulating phagocytosis of macrophage treated with Escherichia coli ( E.coli). Methods:① The mouse leukemia cells lines of monocyte macrophage RAW264.7 (RAW) were cultured in vitro and treated with 30 multiplicity of infection (MOI) dosages of E.coli for 40 minutes, glycerin control group was set up to observe the change of CYP1A1 during infection. ② The RAW cells with CYP1A1 overexpression (CYP1A1/RAW) and knock out (CYP1A1 KO/RAW) were cultured in vitro and treated with 30 MOI E. coli for 40 minutes, while the negative controlled RAW cells (NC/RAW) were established as control to observe the relationship between cell phagocytosis and CYP1A1 expression, and the effect of CYP1A1 on phagocytic receptor [scavenger receptor-A (SR-A)] and its signal pathway [mitogen-activated protein kinase (MAPK) pathway]. ③ NC/RAW and CYP1A1 KO/RAW cells were cultured in vitro and pretreated with 1 μmol/L extracellular signal-regulated kinase (ERK) inhibitor (U0126) for 2 hours, and then treated with 30 MOI E.coli for 40 minutes, phosphate buffered solution (PBS) control group was set up to observe whether the effect of CYP1A1 on phagocytosis through controlled the MAPK pathway. ④ The RAW cells were cultured in vitro and pretreated with 100 nmol/L CYP1A1 hydroxylase active product 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE] for 2 hours, and then treated with 30 MOI E.coli for 40 minutes, and PBS control group was set up to observe whether the effect of CYP1A1 on phagocytosis was related to CYP1A1 hydroxylating metabolite. ⑤ The RAW cells with overexpression CYP1A1 hydroxylase-activity mutation (CYP1A1m/RAW) were cultured in vitro and treated with 30 MOI E.coli for 40 minutes, the CYP1A1/RAW cells were set up as control group to observe whether the effect of CYP1A1 on phagocytosis was related to CYP1A1 hydroxylase-activity. Results:① Compared with glycerin control group, CYP1A1 mRNA expression was significantly increased by E.coli stimulation (2 -ΔΔCt: 7.79±0.71 vs. 1.00±0.00, P < 0.05), indicating that CYP1A1 might participate in regulating infection progress. ② Compared with NC/RAW cells, the number of E.coli colonies phagocytized by CYP1A1/RAW cells was significantly decreased after 40 minutes of E.coli stimulation (×10 3 CFU/mL: 4.67±3.06 vs. 15.67±5.03, P < 0.05), while CYP1A1 KO/RAW cells had a significant increase in the number of E.coli colonies phagocytized (×10 3 CFU/mL: 46.00±5.29 vs. 15.67±5.03, P < 0.05), suggesting that CYP1A1 might negatively control macrophage phagocytosis function. Meanwhile, compared with NC/RAW cells, the expression of SR-A mRNA in CYP1A1/RAW cells was significantly down-regulated (2 -ΔΔCt: 0.31±0.03 vs. 1.00±0.00, P < 0.05), and the activation level of ERK was significantly reduced. However, the expression of SR-A mRNA in CYP1A1 KO/RAW cells was significantly up-regulated (2 -ΔΔCt: 3.74±0.25 vs. 1.00±0.00, P < 0.05), and the activation of ERK was enhanced, indicating that CYP1A1 could negatively regulate phagocytic receptors and their signaling pathways.③ Compared with PBS, U0126 pretreatment significantly inhibited the CYP1A1 knockout induced upregulation of SR-A mRNA expression (2 -ΔΔCt: 0.62±0.05 vs. 4.38±0.39, P < 0.05) and ERK activation, and inhibited the enhancement of phagocytosis in macrophages induced by CYP1A1 knock out [ E.coli colonies phagocytized by cells (×10 3 CFU/mL): 12.67±1.15 vs. 45.33±4.16, P < 0.05], suggesting that CYP1A1 inhibited macrophage phagocytosis function by regulating ERK activation. ④ Compared with PBS, the phagocytosis of RAW cells pretreated with 12(S)-HETE did not change significantly [ E.coli colonies phagocytized by cells (×10 3 CFU/mL): 17.00±1.00 vs. 16.33±2.52, P > 0.05], suggesting that CYP1A1 might not control phagocytosis function by its hydroxylase-activity metabolism 12(S)-HETE. ⑤ Compared with CYP1A1/RAW cells, there was no significant change in the phagocytic function of CYP1A1m/RAW cells [ E.coli colonies phagocytized by cells (×10 3 CFU/mL): 3.67±1.15 vs. 3.33±0.58, P > 0.05], suggesting that CYP1A1 might not control phagocytosis function by its hydroxylase-activity. Conclusion:CYP1A1 can negatively regulate the phagocytosis of macrophages by inhibiting the activation of ERK and reducing the expression of SR-A, but this regulatory effect is not related to the activity of CYP1A1 hydroxylase and its pro-inflammatory metabolism 12(S)-HETE.

Nanopolyphenol rejuvenates microglial surveillance of multiple misfolded proteins through metabolic reprogramming

Microglial surveillance plays an essential role in clearing misfolded proteins such as amyloid-beta, tau, and α-synuclein aggregates in neurodegenerative diseases. However, due to the complex structure and ambiguous pathogenic species of the misfolded proteins, a universal approach to remove the misfolded proteins remains unavailable. Here, we found that a polyphenol, α-mangostin, reprogrammed metabolism in the disease-associated microglia through shifting glycolysis to oxidative phosphorylation, which holistically rejuvenated microglial surveillance capacity to enhance microglial phagocytosis and autophagy-mediated degradation of multiple misfolded proteins. Nanoformulation of α-mangostin efficiently delivered α-mangostin to microglia, relieved the reactive status and rejuvenated the misfolded-proteins clearance capacity of microglia, which thus impressively relieved the neuropathological changes in both Alzheimer's disease and Parkinson's disease model mice. These findings provide direct evidences for the concept of rejuvenating microglial surveillance of multiple misfolded proteins through metabolic reprogramming, and demonstrate nanoformulated α-mangostin as a potential and universal therapy against neurodegenerative diseases.

Hematoma regression: a therapeutic target for intracerebral hemorrhage / 国际脑血管病杂志

The disability and mortality rate of patients with intracerebral hemorrhage are very high. At present, there is no effective treatment to improve the outcome of patients with intracerebral hemorrhage. Mechanical compression of hematoma and release of toxic products are the main causes of primary and secondary brain injury in patients with intracerebral hemorrhage, while safe and effective acceleration of hematoma regression is the key strategy to improve the neurological deficit in patients with intracerebral hemorrhage. Microglia/macrophages are the main phagocytic system that mediates hematoma clearance and are mainly polarized into M1 and M2 phenotypes. Cell surface receptors and possible signal transduction pathways play an important role in regulating the endogenous hematoma regression mediated by microglia/macrophages, and may become a new target for clinical treatment of intracerebral hemorrhage and improvement of the outcomes of patients in the future.

Recent progress of nanoparticle-enabled modulation of macrophages for cancer immunotherapy / 药学学报

Macrophages play an important role in maintaining homeostasis of the body, and they are also one of the most abundant immune cells in the tumor microenvironment (TME). These macrophages are often called tumor-associated macrophages (TAMs), which play an important role in the development of tumor and are an important target for tumor therapy. Studies have shown that tumor growth and metastasis can be inhibited by regulating the function of macrophages, but the therapeutic efficacy was often hampered by the poor performance of the drugs such as lack of targeting, poor solubility, low bioavailability, and severe side effects. After introduction of the background of macrophage and tumor therapy, this review focuses on the research progress of nano-drug delivery systems in the modulation of the function of macrophages to enhance tumor immunotherapy. Nano-drug delivery systems are diverse in structures and functions, and can regulate macrophage functions through a variety of mechanisms. Four important aspects of macrophage modulation, which included TAMs depletion, repolarization of TAMs, promoted phagocytosis of TAMs, and combinational modulation of TAMs were summarized. Each strategy together with typical examples was reviewed and future directions in this field were also prospected.

Immunomodulatory and Antioxidant Activity of Gouqi Chewable Tablets / 中国实验方剂学杂志

ObjectiveTo explore the regulatory effect of Gouqi chewable tablets on innate and adaptive immunity in normal mice and its antioxidant activity in vitro and in vivo. MethodThe effects of low-， medium-， and high-dose groups （0.25， 0.5， 1.5 g·kg-1） on the immune function of normal mice were observed by carbon clearance test， immune organ index test， serum hemolysin test， ConA-induced splenic lymphocyte proliferation test， and natural killer cell （NK cell） activity test. The effects of Gouqi chewable tablets on the antioxidant capacity in vivo were determined by detecting the content of superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px）， and malondialdehyde （MDA） in mice serum. The in vitro antioxidant activity of Gouqi chewable tablets was detected by 2，2'-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid） diammonium salt （ABTS）， 2，2-diphenyl-1-picrylhydrazyl （DPPH）， and hydroxyl radical scavenging tests. ResultCompared with the blank control group， the low-， medium-， and high-dose groups of Gouqi chewable tablets improved the viability of NK cells， the proliferation of splenic lymphocytes， and the level of serum hemolysin antibody in mice （P<0.05）. The high-dose group increased the thymus index， spleen index， and phagocytic function of macrophages （P<0.05， P<0.01）. As compared with the blank control group， the activity of GSH-Px in mice serum in the medium-dose group was increased （P<0.05）， and the content of MDA in mice serum in the high-dose group was decreased （P<0.05）. In in vitro antioxidant tests， the median inhibitory concentration （IC50） values of Gouqi chewable tablets were 1.64±0.20， 2.04±0.03， and 10.27±0.03 g·L-1 by the DPPH， ABTS， and OH- free radical method， respectively. Those results indicated that Gouqi chewable tablets have good antioxidant effects in vitro. ConclusionGouqi chewable tablets can enhance the immune function of mice with good antioxidant effects.

A method for measuring the ADCP potency of anti-CD38 monoclonal antibody / 药学学报

A method to measure the antibody-dependent cell-mediated phagocytosis (ADCP) potency of anti-CD38 mAb was developed based on design of experiment (DoE) with a Jurkat/NFAT/CD32a-FcεRIγ transgenic cell line as the effector cell, the Daudi cell line as the target cells, and luciferase as the detection system. The DoE method was used for optimization of experimental parameters and methodological validation. The results show that anti-CD38 mAb exhibits a dose-response relationship with the following four-parameter equation: y = (A - D) / [1 + (x / C)B] + D. Several experimental parameters were optimized by statistical experimental design and determined as follows: the working concentration of anti-CD38 mAb was 800-20.81 ng·mL-1, the density of the target cells was 7.5×104 per well, and the density of effector cells was 2.5×104 per well, with an induction time of 6 h. The method showed good specificity. The recovery rate for samples from 5 different groups showed that the relative potencies of anti-CD38 mAb were (59.97 ± 4.74) %, (82.44 ± 5.15) %, (110.69 ± 11.71) %, (129.23 ± 5.22)% and (162.15 ± 3.66) %. The recoveries ranged from 103% to 120% and the RSDs of the above results were all less than 11%. The linear detection range was 50%-150%. Based on DoE design, this method for measuring ADCP potency of anti-CD38 mAb was optimized and validated with good specificity, repeatability and accuracy. This method can be used for evaluation of ADCP biological activity of anti-CD38 mAbs.

In vitro method establishment for detecting monocyte phagocytosis of sensitized RBCs by flow cytometry / 中国输血杂志

【Objective】 To establish an experimental method for detecting phagocytosis of sensitized red blood cells in vitro by flow cytometry. 【Methods】 Mononuclear cells were isolated from the peripheral blood of blood donors and cultured in a cell incubator for 1 hour, and then adherent monocytes were isolated and obtained. Dib-positive red blood cells (RBCs) were labeled with PKH26 and then sensitized with IgG anti-Dib. The sensitized RBCs were added to monocytes for in vitro phagocytosis assay. Monocytes were labeled with FITC anti-human CD14, then phagocytosis was measured by flow cytometry, and the phagocytic efficiency was calculated. The method was used to detect the phagocytic efficiency of monocytes on human IgG anti-D sensitized RBCs with different titers. 【Results】 The phagocytic efficiency of monocytes was averaged at 5% (1.2%~7.6%, SD 3.30) versus 81% (71.4%~92.7%, SD 8.65) in the negative versus positive control group, respectively. Phagocytic activity of monocytes mediated by anti-D was correlated with the antibody titer. The phagocytosis efficiency was within 10% when the antibody titer was lower than 32 and increased sharply when the titer was between 32 to 128, it entered a plateau and stabilized at 80% at the titer above 256. 【Conclusion】 A detection platform for detecting phagocytosis-sensitized RBCs in vitro by flow cytometry has been successfully established. It can be used to assess the clinical significance of red blood cell allotype or autologous IgG antibodies.

Effect of IgG fragments in IVIG(pH4)on phagocytosis of sensitized erythrocytes by macrophage / 中国输血杂志

【Objective】 To research the effect of the Fc, Fab and F(ab′)2 fragments of immunoglobulin G, the main components of Human Immunoglobulin(pH4) for Intravenous Injection(IVIG), on the phagocytic function of macrophages derived from THP-1 cells. 【Methods】 First of all, IVIG was digested with papain and pepsin to obtain Fc, Fab and F(ab′)2, and these components were then identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Afterwards, propylene glycol monomethyl ether acetate (PMA) was used to induce THP-1 cells to differentiate into M0 macrophages. Finally, the sensitized erythrocytes were labeled with carboxy fluorescein succinimidyl ester (CFSE), and the effect of the above components on the phagocytic ability of M0 macrophages to engulf sensitized erythrocytes was detected by flow cytometry. 【Results】 The identification results of SDS-PAGE showed that the prepared IgG fragments met the requirements of subsequent experiments. Flow cytometry performs showed that the phagocytosis model of M0 macrophages had been successfully established. When the concentration of Fc increased from 0.1μg/ mL to 10μg/ mL, the phagocytosis rate of erythrocytes sensitized by M0 macrophages decreased from (24.21±0.58) % to (12.27±0.19) %. When the concentration of IVIG protein increased from 0.1 μg/ml to 10 μg/ml, the phagocytosis rate decreased from (20.57±0.39) % to (0.20±0.03) %. Meanwhile, at the same protein concentration (10 μg/ml), the inhibitory effect of Fc on phagocytosis was only half that of IVIG. In addition, Fab, F(ab′)2, and human serum albumin could not inhibit phagocytosis of M0 macrophages. 【Conclusion】 IVIG can effectively inhibit the phagocytosis of THP-1 derived M0 macrophages, which is mainly dependent on the Fc, but not related to the Fab of IgG and F (ab′)2.

Effect of Aspergillus fumigatus on the autophagic flux in murine macrophages: a preliminary study / 中华皮肤科杂志

Objective:To explore the effect of Aspergillus fumigatus ( A. fumigatus) on the autophagic flux in murine bone marrow-derived macrophages (BMDM) . Methods:Murine BMDM were in vitro cultured with heat-killed A. fumigatus for 0, 0.5, 4, and 12 hours. Then, cellular proteins were extracted, and Western blot analysis was performed to detect the conversion of the key autophagy protein microtubule-associated protein 1 light chain 3 (LC3) -Ⅰ to LC3-Ⅱ, and to determine the protein expression of phosphorylated mammalian target of rapamycin (p-mTOR) Ser2481. Additionally, murine BMDM were in vitro cultured with A. fumigatus alone or in combination with different lysosomal inhibitors, including the cysteine cathepsin inhibitor E-64d + pepstatin, bafilomycin-A1 (BAF-A1) , ammonium chloride (NH 4Cl) , and chloroquine, for 4 or 12 hours. Then, Western blot analysis was performed to investigate the effect of A. fumigatus on newly formed LC3-Ⅱ and basal autophagic flux, and confocal laser scanning fluorescence microscopy to analyze the colocalization of A. fumigatus with LC3 and Rubicon (a RUN domain Beclin-1-interacting and cysteine-rich-domain-containing protein) . Experimental results at different treatment time points were analyzed by using unpaired t test, and results of experiments evaluating the effect of two factors ( A. fumigatus spores and autophagosome inhibitors) were analyzed by 2 × 2 factorial analysis. Results:After in vitro co-culture with A. fumigatus for 0.5, 4, 12 hours, Western blot analysis showed that the conversion of LC3-Ⅰ to LC3-Ⅱ increased over time in murine BMDM compared with the control (0 hour) group ( t = 6.58, 3.28, 3.02, respectively, all P < 0.05) , but the protein expression level of p-mTOR (Ser2481) did not significantly differ at different treatment time points ( t = 0.441, 0.477, 0.382, P = 0.682, 0.660, 0.722, respectively) . After 4- and 12-hour in vitro treatment, the accumulation levels of LC3-Ⅱ in BMDM significantly increased in the A. fumigatus + chloroquine group compared with the chloroquine-alone group ( t = 2.13, 2.78, respectively, both P < 0.05) , in the A. fumigatus + NH 4Cl group compared with the NH 4Cl-alone group ( t = 2.92, 2.92, respectively, both P < 0.05) , in the A. fumigatus + BAF-A1 group compared with the BAF-A1-alone group ( t = 2.13, 2.13, respectively, both P < 0.05) , and in the A. fumigatus + E-64d + pepstatin group compared with the E-64d + pepstatin group ( t = 2.13, 2.92, respectively, both P < 0.05) . After 8-hour treatment with calcofluor white-labeled A. fumigatus spores, confocal laser scanning fluorescence microscopy showed that LC3 and Rubicon mainly surrounded A. fumigatus, suggesting their colocalization with A. fumigatus. Conclusion:A. fumigatus can in vitro increase the basal autophagic flux in murine BMDM.

The disbalance of LRP1 and SIRPα by psychological stress dampens the clearance of tumor cells by macrophages

The relationship between chronic psychological stress and tumorigenesis has been well defined in epidemiological studies; however, the underlying mechanism remains underexplored. In this study, we discovered that impaired macrophage phagocytosis contributed to the psychological stress-evoked tumor susceptibility, and the stress hormone glucocorticoid (GC) was identified as a principal detrimental factor. Mechanistically, GC disturbed the balance of the "eat me" signal receptor (low-density lipoprotein receptor-related protein-1, LRP1) and the "don't eat me" signal receptor (signal regulatory protein alpha, SIRPα). Further analysis revealed that GC led to a direct, glucocorticoid receptor (GR)-dependent trans-repression of LRP1 expression, and the repressed LRP1, in turn, resulted in the elevated gene level of SIRPα by down-regulating miRNA-4695-3p. These data collectively demonstrate that stress induces the imbalance of the LRP1/SIRPα axis and entails the disturbance of tumor cell clearance by macrophages. Our findings provide the mechanistic insight into psychological stress-evoked tumor susceptibility and indicate that the balance of LRP1/SIRPα axis may serve as a potential therapeutic strategy for tumor treatment.

Neutrophils phagocytosing fungal hyphae in urinary sediment / Neutrófilos fagocitando hifas no sedimento urinário

Abstract The Phagocytosis of fungal structures by neutrophils is a well-documented function of these immune cells. However, neutrophil phagocytosis of hyphal structures in the urine sediment is not usually observed during routine sample evaluation. This is a case of hyphal phagocytosis by neutrophils in the urine of a kidney allograft recipient patient.

Resumo A fagocitose de estruturas fúngicas por neutrófilos é uma função bem documentada destas células imunes. No entanto, a fagocitose de hifas por neutrófilos no sedimento urinário não é normalmente observada durante avaliação de rotina de amostras. Este é um caso de fagocitose de hifas por neutrófilos na urina de um paciente receptor de aloenxerto renal.

Methods of macrophages activation and their modulation for the prospection of new antileishmania drugs: a review

Leishmaniasis are a group of parasitic zoonoses provoked by protozoa from Leishmania genus and belonging to the group of neglected tropical diseases. The search and development for new drugs is necessary not only to investigate the activity against only the parasite, but also to investigate the possible synergistic effect of new drugs with the immune response of the host. In the present review, macrophages are pointed out as potential targets of the investigation of new antileishmanial drugs, and some methodologies in order to assess their activation as response to Leishmania-infected cells are presented. Macrophages are an important role in the cellular immune response, since they are cells from mononuclear phagocytic system, the first line of defense of the host, against parasites from Leishmania genus. Phagocytic capacity, lysosomal activity, increase of nitric oxide and intracellular calcium levels are parameters regarding assessment of macrophages activation which allow them to be more hostile in order to solve the infection and lead the patient to cure. In this context, we bring 19 substances already investigated and that activate macrophages, what makes them promising in the antileishmanial treatment. Therefore, assessment of macrophages activation, are important tools for discovery of immunomodulatory compounds which have potential to act in synergism with host immune response. Such compounds might be promising as monotherapy in the treatment of leishmaniasis, as well as being used as adjuvants in vaccines and/or in combination with conventional drugs.

An in vitro model mimicking the complement system to favor directed phagocytosis of unwanted cells

BACKGROUND: Opsonization, is the molecular mechanism by which target molecules promote interactions with phagocyte cell surface receptors to remove unwanted cells by induced phagocytosis. We designed an in vitro system to demonstrate that this procedure could be driven to eliminate adipocytes, using peptides mimicking regions of the complement protein C3b to promote opsonization and enhance phagocytosis. Two cell lines were used: (1) THP-1 monocytes differentiated to macrophages, expressing the C3b opsonin receptor CR1 in charge of the removal of unwanted coated complexes; (2) 3T3-L1 fibroblasts differentiated to adipocytes, expressing AQP7, to evaluate the potential of peptides to stimulate opsonization. (3) A co-culture of the two cell lines to demonstrate that phagocytosis could be driven to cell withdrawal with high efficiency and specificity. RESULTS: An array of peptides were designed and chemically synthesized p3691 and p3931 joined bound to the CR1 receptor activating phagocytosis (p < 0.033) while p3727 joined the AQP7 protein (p < 0.001) suggesting that opsonization of adipocytes could occur. In the co-culture system p3980 and p3981 increased lipid uptake to 91.2% and 89.0%, respectively, as an indicator of potential adipocyte phagocytosis. CONCLUSIONS: This in vitro model could help understand the receptor­ligand interaction in the withdrawal of unwanted macromolecules in vivo. The adipocyte-phagocytosis discussed may help to control obesity, since peptides of C3b stimulated the CR1 receptor, promoting opsonisation and phagocytosis of lipidcontaining structures, and recognition of AQP7 in the differentiated adipocytes, favored the phagocytic activity of macrophages, robustly supported by the co-culture strategy.

Pharmacological Activation of RXR-α Promotes Hematoma Absorption via a PPAR-γ-dependent Pathway After Intracerebral Hemorrhage / 神经科学通报·英文版

Endogenously eliminating the hematoma is a favorable strategy in addressing intracerebral hemorrhage (ICH). This study sought to determine the role of retinoid X receptor-α (RXR-α) in the context of hematoma absorption after ICH. Our results showed that pharmacologically activating RXR-α with bexarotene significantly accelerated hematoma clearance and alleviated neurological dysfunction after ICH. RXR-α was expressed in microglia/macrophages, neurons, and astrocytes. Mechanistically, bexarotene promoted the nuclear translocation of RXR-α and PPAR-γ, as well as reducing neuroinflammation by modulating microglia/macrophage reprograming from the M1 into the M2 phenotype. Furthermore, all the beneficial effects of RXR-α in ICH were reversed by the PPAR-γ inhibitor GW9662. In conclusion, the pharmacological activation of RXR-α confers robust neuroprotection against ICH by accelerating hematoma clearance and repolarizing microglia/macrophages towards the M2 phenotype through PPAR-γ-related mechanisms. Our data support the notion that RXR-α might be a promising therapeutic target for ICH.

Once upon a time, inflammation

Inflammation has accompanied humans since their first ancestors appeared on Earth. Aulus Cornelius Celsus (25 BC-50 AD), a Roman encyclopedist, offered a still valid statement about inflammation: "Notae vero inflammationis sunt quatuor: rubor et tumor cum calore and dolore", defining the four cardinal signs of inflammation as redness and swelling with heat and pain. While inflammation has long been considered as a morbid phenomenon, John Hunter (18th century) and Elie Metchnikoff (19th century) understood that it was a natural and beneficial event that aims to address a sterile or an infectious insult. Many other famous scientists and some forgotten ones have identified the different cellular and molecular players, and deciphered the different mechanisms of inflammation. This review pays tribute to some of the giants who made major contributions, from Hippocrates to the late 19th and first half of the 20th century. We particularly address the discoveries related to phagocytes, diapedesis, chemotactism, and fever. We also mention the findings of the various inflammatory mediators and the different approaches designed to treat inflammatory disorders.(AU)