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1.
Elife ; 102021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34726151

RESUMO

Coordination of diverse individuals often requires sophisticated communications and high-order computational abilities. Microbial populations can exhibit diverse individualistic behaviors, and yet can engage in collective migratory patterns with a spatially sorted arrangement of phenotypes. However, it is unclear how such spatially sorted patterns emerge from diverse individuals without complex computational abilities. Here, by investigating the single-cell trajectories during group migration, we discovered that, despite the constant migrating speed of a group, the drift velocities of individual bacteria decrease from the back to the front. With a Langevin-type modeling framework, we showed that this decreasing profile of drift velocities implies the spatial modulation of individual run-and-tumble random motions, and enables the bacterial population to migrate as a pushed wave front. Theoretical analysis and stochastic simulations further predicted that the pushed wave front can help a diverse population to stay in a tight group, while diverse individuals perform the same type of mean reverting processes around centers orderly aligned by their chemotactic abilities. This mechanism about the emergence of orderly collective migration from diverse individuals is experimentally demonstrated by titration of bacterial chemoreceptor abundance. These results reveal a simple computational principle for emergent ordered behaviors from heterogeneous individuals.


Assuntos
Quimiotaxia , Escherichia coli/fisiologia , Modelos Biológicos , Análise de Célula Única
2.
Dis Markers ; 2021: 6803510, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603560

RESUMO

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most significant public health threat worldwide. Patients with severe COVID-19 usually have pneumonia concomitant with local inflammation and sometimes a cytokine storm. Specific components of the SARS-CoV-2 virus trigger lung inflammation, and recruitment of immune cells to the lungs exacerbates this process, although much remains unknown about the pathogenesis of COVID-19. Our study of lung type II pneumocyte cells (A549) demonstrated that ORF7, an open reading frame (ORF) in the genome of SARS-CoV-2, induced the production of CCL2, a chemokine that promotes the chemotaxis of monocytes, and decreased the expression of IL-8, a chemokine that recruits neutrophils. A549 cells also had an increased level of IL-6. The results of our chemotaxis Transwell assay suggested that ORF7 augmented monocyte infiltration and reduced the number of neutrophils. We conclude that the ORF7 of SARS-CoV-2 may have specific effects on the immunological changes in tissues after infection. These results suggest that the functions of other ORFs of SARS-CoV-2 should also be comprehensively examined.


Assuntos
COVID-19/metabolismo , Quimiotaxia , Monócitos/patologia , Neutrófilos/patologia , Fases de Leitura Aberta/fisiologia , Pneumonia/patologia , Proteínas Virais/metabolismo , Células A549 , Quimiocina CCL2/metabolismo , Humanos , Técnicas In Vitro , Monócitos/imunologia , Monócitos/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Pneumonia/imunologia , Pneumonia/metabolismo , SARS-CoV-2/metabolismo , Proteínas Virais/genética
3.
Nat Commun ; 12(1): 5788, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34608163

RESUMO

The chytrid fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans cause the skin disease chytridiomycosis in amphibians, which is driving a substantial proportion of an entire vertebrate class to extinction. Mitigation of its impact is largely unsuccessful and requires a thorough understanding of the mechanisms underpinning the disease ecology. By identifying skin factors that mediate key events during the early interaction with B. salamandrivorans zoospores, we discovered a marker for host colonization. Amphibian skin associated beta-galactose mediated fungal chemotaxis and adhesion to the skin and initiated a virulent fungal response. Fungal colonization correlated with the skin glycosylation pattern, with cutaneous galactose content effectively predicting variation in host susceptibility to fungal colonization between amphibian species. Ontogenetic galactose patterns correlated with low level and asymptomatic infections in salamander larvae that were carried over through metamorphosis, resulting in juvenile mortality. Pronounced variation of galactose content within some, but not all species, may promote the selection for more colonization resistant host lineages, opening new avenues for disease mitigation.


Assuntos
Anfíbios/microbiologia , Batrachochytrium/patogenicidade , Dermatomicoses/veterinária , Galactose/metabolismo , Pele/metabolismo , Anfíbios/classificação , Anfíbios/crescimento & desenvolvimento , Animais , Batrachochytrium/fisiologia , Biomarcadores/química , Biomarcadores/metabolismo , Carboidratos/química , Quimiotaxia , Dermatomicoses/microbiologia , Resistência à Doença , Galactose/química , Estágios do Ciclo de Vida , Pele/microbiologia , Esporos Fúngicos/patogenicidade , Esporos Fúngicos/fisiologia , Taxa de Sobrevida , Virulência
4.
Nat Immunol ; 22(11): 1375-1381, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34663979

RESUMO

Migration of leukocytes from the skin to lymph nodes (LNs) via afferent lymphatic vessels (LVs) is pivotal for adaptive immune responses1,2. Circadian rhythms have emerged as important regulators of leukocyte trafficking to LNs via the blood3,4. Here, we demonstrate that dendritic cells (DCs) have a circadian migration pattern into LVs, which peaks during the rest phase in mice. This migration pattern is determined by rhythmic gradients in the expression of the chemokine CCL21 and of adhesion molecules in both mice and humans. Chronopharmacological targeting of the involved factors abrogates circadian migration of DCs. We identify cell-intrinsic circadian oscillations in skin lymphatic endothelial cells (LECs) and DCs that cogovern these rhythms, as their genetic disruption in either cell type ablates circadian trafficking. These observations indicate that circadian clocks control the infiltration of DCs into skin lymphatics, a process that is essential for many adaptive immune responses and relevant for vaccination and immunotherapies.


Assuntos
Imunidade Adaptativa , Quimiotaxia , Relógios Circadianos , Células Dendríticas/imunologia , Linfonodos/imunologia , Vasos Linfáticos/imunologia , Pele/imunologia , Idoso , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Quimiocina CCL21/genética , Quimiocina CCL21/metabolismo , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Células Dendríticas/metabolismo , Feminino , Humanos , Linfonodos/metabolismo , Vasos Linfáticos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pele/metabolismo , Fatores de Tempo
5.
PLoS One ; 16(10): e0258270, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34653205

RESUMO

Chemokines play diverse and fundamental roles in the immune system and human disease, which has prompted their structural and functional characterisation. Production of recombinant chemokines that are folded and bioactive is vital to their study but is limited by the stringent requirements of a native N-terminus for receptor activation and correct disulphide bonding required to stabilise the chemokine fold. Even when expressed as fusion proteins, overexpression of chemokines in E. coli tends to result in the formation of inclusion bodies, generating the additional steps of solubilisation and refolding. Here we present a novel method for producing soluble chemokines in relatively large amounts via a simple two-step purification procedure with no requirements for refolding. CXCL8 produced by this method has the correct chemokine fold as determined by NMR spectroscopy and in chemotaxis assays was indistinguishable from commercially available chemokines. We believe that this protocol significantly streamlines the generation of recombinant chemokines.


Assuntos
Bioquímica/métodos , Interleucina-8/biossíntese , Interleucina-8/isolamento & purificação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Quimiotaxia , Humanos , Espectroscopia de Prótons por Ressonância Magnética
6.
Zhongguo Zhong Yao Za Zhi ; 46(16): 4201-4207, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34467733

RESUMO

The present study aims to investigate the effects of the main components(aesculin, berberine hydrochloride, and anemoside B4) in the butyl alcohol extract of Baitouweng Decoction(BAEB) on the chemotaxis of neutrophils induced by dimethyl sulfoxide(DMSO). HL60 cells were cultivated in RPMI-1640 complete medium, and transferred into a 6-well plate(2 × 10~5 per mL) with 4 mL in each well, followed by incubation with DMSO at 1.3% for five days. The morphologic changes of cells were observed under an inverted microscope. The CD11 b expression after DMSO induction was analyzed by flow cytometry. The effects of aesculin, berberine hydrochloride, and anemoside B4 on the cell proliferation and migration were detected by CCK8 assay and Transwell assay, respectively. The effects of the main components on the production and polarization of F-actin protein were also examined by flow cytometry and laser confocal microscopy. PI3 K/Akt signaling pathway was checked by Western blot. As revealed by the results, neutrophil-like HL60 cells were observed after DMSO induction. The CD11 b expression in these cells increased significantly as indicated by the flow cytometry. Additionally, 100 µg·mL~(-1) aesculin, 8 µg·mL~(-1) berberine hydrochloride, and 80 µg·mL~(-1) anemoside B4 were potent in inhibiting the migration of neutrophils and reducing F-actin expression. Berberine hydrochloride was verified to be capable of diminishing phosphorylated PI3 K/Akt protein expression. The findings indicate that aesculin, anemoside B4, and especially berberine hydrochloride in the BAEB can inhibit the chemotaxis of neutrophils, which is possibly achieved by the inhibition of F-actin and PI3 K/Akt signaling pathway.


Assuntos
Berberina , Medicamentos de Ervas Chinesas , 1-Butanol , Berberina/farmacologia , Quimiotaxia , Medicamentos de Ervas Chinesas/farmacologia , Neutrófilos
7.
Nat Commun ; 12(1): 5442, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521846

RESUMO

Reversible switching of the bacterial flagellar motor between clockwise (CW) and counterclockwise (CCW) rotation is necessary for chemotaxis, which enables cells to swim towards favorable chemical habitats. Increase in the viscous resistance to the rotation of the motor (mechanical load) inhibits switching. However, cells must maintain homeostasis in switching to navigate within environments of different viscosities. The mechanism by which the cell maintains optimal chemotactic function under varying loads is not understood. Here, we show that the flagellar motor allosterically controls the binding affinity of the chemotaxis response regulator, CheY-P, to the flagellar switch complex by modulating the mechanical forces acting on the rotor. Mechanosensitive CheY-P binding compensates for the load-induced loss of switching by precisely adapting the switch response to a mechanical stimulus. The interplay between mechanical forces and CheY-P binding tunes the chemotactic function to match the load. This adaptive response of the chemotaxis output to mechanical stimuli resembles the proprioceptive feedback in the neuromuscular systems of insects and vertebrates.


Assuntos
Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Flagelos/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil/metabolismo , Regulação Alostérica , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Mimetismo Biológico , Fenômenos Biomecânicos , Quimiotaxia/genética , Escherichia coli/genética , Escherichia coli/ultraestrutura , Retroalimentação Sensorial/fisiologia , Flagelos/genética , Flagelos/ultraestrutura , Expressão Gênica , Insetos/fisiologia , Proteínas Quimiotáticas Aceptoras de Metil/química , Proteínas Quimiotáticas Aceptoras de Metil/genética , Pinças Ópticas , Ligação Proteica , Vertebrados/fisiologia , Viscosidade
8.
J Hazard Mater ; 416: 126246, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492992

RESUMO

Bacterial chemotaxis can improve the efficiency of aromatic compound degradation, however, knowledge of how bacteria sense high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), is limited. Here, the chemotactic responses of Novosphingobium pentaromativorans US6-1 to 9 aromatic compounds were investigated. The results showed that US6-1 chemotactically responded to phenanthrene (PHE), pyrene (PYR), benzo[a]pyrene (BaP) and their six metabolites. Six methyl-accepting chemotaxis proteins (MCPs) were annotated from US6-1 genome, four of which contained putative ligand-binding domains (LBDs). To confirm whether these four MCPs were involved in triggering chemotaxis toward PAHs, the MCP mutants were constructed. Observations showed a loss of the chemotactic responses to benzoate, phthalate, PHE and BaP only in the mutant ∆mcp03030. Surface plasmon resonance (SPR) assays further confirmed that MCP03030LBD specifically bound phthalate, PHE, PYR and BaP, while MCP18870LBD bound only PYR. The mutant ∆mcp03030-∆mcp18870 was then constructed and was shown to have lost the chemotactic response to 5 aromatic compounds. Combined with the effects of outer membrane transporter deletion on chemotaxis and MCP deletion on the PAH degradation, our study demonstrated that the chemoreceptors MCP03030 and MCP18870 can recognize PAHs and their metabolites in the periplasm, triggering metabolism-dependent and metabolism-independent chemotaxis, and be linked with HMW-PAH biodegradation.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Sphingomonadaceae , Biodegradação Ambiental , Quimiotaxia , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Sphingomonadaceae/genética
9.
Nat Commun ; 12(1): 5462, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526503

RESUMO

Salicylic acid is a phenolic phytohormone which controls plant growth and development. A methyl ester (MSA) derivative thereof is volatile and involved in plant-insect or plant-plant communication. Here we show that the nematode-trapping fungus Duddingtonia flagrans uses a methyl-salicylic acid isomer, 6-MSA as morphogen for spatiotemporal control of trap formation and as chemoattractant to lure Caenorhabditis elegans into fungal colonies. 6-MSA is the product of a polyketide synthase and an intermediate in the biosynthesis of arthrosporols. The polyketide synthase (ArtA), produces 6-MSA in hyphal tips, and is uncoupled from other enzymes required for the conversion of 6-MSA to arthrosporols, which are produced in older hyphae. 6-MSA and arthrosporols both block trap formation. The presence of nematodes inhibits 6-MSA and arthrosporol biosyntheses and thereby enables trap formation. 6-MSA and arthrosporols are thus morphogens with some functions similar to quorum-sensing molecules. We show that 6-MSA is important in interkingdom communication between fungi and nematodes.


Assuntos
Ascomicetos/fisiologia , Caenorhabditis elegans/fisiologia , Hifas/fisiologia , Comportamento Predatório/fisiologia , Ácido Salicílico/metabolismo , Animais , Ascomicetos/genética , Ascomicetos/metabolismo , Quimiotaxia/fisiologia , Proteínas Fúngicas/metabolismo , Hifas/genética , Hifas/metabolismo , Policetídeo Sintases/metabolismo , Ácido Salicílico/química , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo
10.
Antonie Van Leeuwenhoek ; 114(11): 1771-1789, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34510303

RESUMO

Understanding the role of chemotaxis in ecological interactions between plants and microbes in the rhizosphere is necessary to optimize biocontrol strategies targeting plant soil-borne diseases. Therefore, we examined and profiled the antagonistic endophytic bacteria (AEB) population with chemotaxis potential in the medicinal plant Panax notoginseng using a cheA gene-based approach coupled with 16S rRNA sequencing. Phylogenetic analysis of the chemotactic AEB (CAEB) community in P. notoginseng enabled the identification of 56 CAEB strains affiliated with 30 species of Actinobacteria, Firmicutes, and Proteobacteria; Firmicutes, especially Bacillus, were predominant. We then systematically quantified the chemotactic response profiles of CAEB toward five organic acid (OA) attractants: citric acid, fumaric acid (FA), malic acid, oxalic acid, and succinic acid. Further hierarchical cluster analysis revealed that the chemotaxis of CAEB to the same attractant exhibited different patterns among not only genera but also species and even strains of the same species. Following chemotaxis and hierarchical analysis, we selected the strongest chemoattractant, fumaric acid (FA), as the target for evaluating the effects of OAs on the representative CAEB strain Bacillus amyloliquefaciens subsp. plantarum YP1. Application of FA significantly stimulated the chemotaxis ability and growth of YP1, and increased the transcript levels of cheA and biocontrol-related genes in YP1. This is the first study to characterise the diversity of chemotaxis profiles toward OAs in natural bacterial assemblages of P. notoginseng and to highlight how FA promotes the biocontrol-related traits of P. notoginseng-associated CAEB.


Assuntos
Endófitos , Panax notoginseng , Bacillus , Bactérias/genética , Quimiotaxia , Endófitos/genética , Filogenia , Raízes de Plantas , RNA Ribossômico 16S/genética
11.
Nano Lett ; 21(19): 8086-8094, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34559543

RESUMO

Inspired by the tactic organisms in Nature that can self-direct their movement following environmental stimulus gradient, we proposed a DNase functionalized Janus nanoparticle (JNP) nanomotor system for the first time, which can be powered by ultralow nM to µM levels of DNA. The system exhibited interesting chemotactic behavior toward a DNA richer area, which is physiologically related with many diseases including tumors. In the presence of the subtle DNA gradient generated by apoptotic tumor cells, the cargo loaded nanomotors were able to sense the DNA signal released by the cells and demonstrate directional motion toward tumor cells. For our system, the subtle DNA gradient by a small amount (10 µL) of tumor cells is sufficient to induce the chemotaxis behavior of self-navigating and self-targeting ability of our nanomotor system, which promises to shed new light for tumor diagnosis and therapy.


Assuntos
Quimiotaxia , Neoplasias , DNA , Humanos , Movimento (Física) , Neoplasias/tratamento farmacológico
12.
Am J Physiol Heart Circ Physiol ; 321(4): H756-H769, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34506228

RESUMO

Inflammation caused by infiltrating macrophages and T cells promotes plaque growth in atherosclerosis. Cadherin-11 (CDH11) is a cell-cell adhesion protein implicated in several fibrotic and inflammatory diseases. Much of the research on CDH11 concerns its role in fibroblasts, although its expression in immune cells has been noted as well. The objective of this study was to assess the effect of CDH11 on the atherosclerotic immune response. In vivo studies of atherosclerosis indicated an increase in Cdh11 in plaque tissue. However, global loss of Cdh11 resulted in increased atherosclerosis and inflammation. It also altered the immune response in circulating leukocytes, decreasing myeloid cell populations and increasing T-cell populations, suggesting possible impaired myeloid migration. Bone marrow transplants from Cdh11-deficient mice resulted in similar immune cell profiles. In vitro examination of Cdh11-/- macrophages revealed reduced migration, despite upregulation of a number of genes related to locomotion. Flow cytometry revealed an increase in CD3+ and CD4+ helper T-cell populations in the blood of both the global Cdh11 loss and the bone marrow transplant animals, possibly resulting from increased expression by Cdh11-/- macrophages of major histocompatibility complex class II molecule genes, which bind to CD4+ T cells for coordinated activation. CDH11 fundamentally alters the immune response in atherosclerosis, resulting in part from impaired macrophage migration and altered macrophage-induced T-cell activation.NEW & NOTEWORTHY Cadherin-11 is well known to contribute to inflammatory and fibrotic disease. Here, we examined its role in atherosclerosis progression, which is predominantly an inflammatory process. We found that while cadherin-11 is associated with plaque progression, global loss of cadherin-11 exacerbated the disease phenotype. Moreover, loss of cadherin-11 in bone marrow-derived immune cells resulted in impaired macrophage migration and an unexplained increase in circulating helper T cells, presumably due to altered macrophage function without cadherin-11.


Assuntos
Aorta/metabolismo , Doenças da Aorta/metabolismo , Aterosclerose/metabolismo , Caderinas/deficiência , Quimiotaxia , Macrófagos/metabolismo , Placa Aterosclerótica , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Aorta/imunologia , Aorta/patologia , Doenças da Aorta/genética , Doenças da Aorta/imunologia , Doenças da Aorta/patologia , Aterosclerose/genética , Aterosclerose/imunologia , Aterosclerose/patologia , Transplante de Medula Óssea , Caderinas/genética , Modelos Animais de Doenças , Feminino , Ativação Linfocitária , Macrófagos/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Transdução de Sinais , Linfócitos T Auxiliares-Indutores/imunologia
13.
Cells ; 10(9)2021 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-34572122

RESUMO

There is considerable evidence that female reproductive fluid (FRF) interacts intimately with sperm, affecting several sperm traits, including sperm motility and longevity, and ultimately fertilization success. One of the first documented interactions between FRF and sperm is the ability of FRF to attract and guide sperm towards the eggs. However, most of the evidence of FRF's chemoattraction proprieties comes from a limited number of taxa, specifically mammals and invertebrate broadcasting spawners. In other species, small FRF volumes and/or short sperm longevity often impose methodological difficulties resulting in this gap in chemoattraction studies in non-model species. One of the outcomes of sperm chemotaxis is sperm accumulation towards high chemoattractant concentrations, which can be easily quantified by measuring sperm concentration. Here, we tested sperm accumulation towards FRF in the zebrafish, Danio rerio, using an ad hoc developed, 3D printed, device ('sperm selection chamber'). This easy-to-use tool allows to select and collect the sperm that swim towards a chemical gradient, and accumulate in a chemoattractant-filled well thus providing putative evidence for chemoattraction. We found that sperm accumulate in FRF in zebrafish. We also found that none of the sperm quality traits we measured (sperm swimming velocity and trajectory, sperm motility, and longevity) were correlated with this response. Together with the 3D printable project, we provide a detailed protocol for using the selection chamber. The chamber is optimized for the zebrafish, but it can be easily adapted for other species. Our device lays the foundation for a standardized way to measure sperm accumulation and in general chemoattraction, stimulating future research aimed at understanding the role and the mechanisms of sperm chemoattraction by FRF.


Assuntos
Secreções Corporais/metabolismo , Fatores Quimiotáticos/metabolismo , Quimiotaxia , Genitália Feminina/fisiologia , Motilidade Espermática , Espermatozoides/fisiologia , Animais , Feminino , Masculino , Espermatozoides/efeitos dos fármacos , Peixe-Zebra
14.
Int J Mol Sci ; 22(18)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34575860

RESUMO

Immunosuppressants are a mandatory therapy for transplant patients to avoid rejection of the transplanted organ by the immune system. However, there are several known side effects, including alterations of the vasculature, which involve a higher occurrence of cardiovascular events. While the effects of the commonly applied immunosuppressive drugs cyclosporine A (CsA) and tacrolimus (Tac) on mature endothelial cells have been addressed in several studies, we focused our research on the unexplored effects of CsA and Tac on endothelial colony-forming cells (ECFCs), a subgroup of endothelial progenitor cells, which play an important role in vascular repair and angiogenesis. We hypothesized that CsA and Tac induce functional defects and activate an inflammatory cascade via NF-κB signaling in ECFCs. ECFCs were incubated with different doses (0.01 µM-10 µM) of CsA or Tac. ECFC function was determined using in vitro models. The expression of inflammatory cytokines and adhesion molecules was explored by quantitative real-time PCR and flow cytometry. NF-κB subunit modification was assessed by immunoblot and immunofluorescence. CsA and Tac significantly impaired ECFC function, including proliferation, migration, and tube formation. TNF-α, IL-6, VCAM, and ICAM mRNA expression, as well as PECAM and VCAM surface expression, were enhanced. Furthermore, CsA and Tac led to NF-κB p65 subunit phosphorylation and nuclear translocation. Pharmacological inhibition of NF-κB by parthenolide diminished CsA- and Tac-mediated proinflammatory effects. The data of functional impairment and activation of inflammatory signals provide new insight into mechanisms associated with CsA and Tac and cardiovascular risk in transplant patients.


Assuntos
Ciclosporina/farmacologia , Células Endoteliais/efeitos dos fármacos , Inflamação/tratamento farmacológico , Células-Tronco/efeitos dos fármacos , Tacrolimo/farmacologia , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/imunologia , Movimento Celular , Proliferação de Células , Quimiotaxia , Citocinas/metabolismo , Células Progenitoras Endoteliais/efeitos dos fármacos , Humanos , Imunossupressores , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-6/metabolismo , NF-kappa B/metabolismo , Subunidade p50 de NF-kappa B/metabolismo , Neovascularização Patológica , Sesquiterpenos/farmacologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
15.
Cells ; 10(9)2021 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-34572130

RESUMO

BACKGROUND: Whole transgenic or non-transgenic organism model systems allow the screening of pharmacological compounds for protective actions in Alzheimer's disease (AD). AIM: In this study, a plant parasitic nematode, Globodera pallida, which assimilates intact peptides from the external environment, was investigated as a new potential non-transgenic model system of AD. Methods: Fresh second-stage juveniles of G. pallida were used to measure their chemosensory, perform immunocytochemistry on their neurological structures, evaluate their survival rate, measure reactive oxygen species, and determine total oxidized glutathione to reduced glutathione ratio (GSSG/GSH) levels, before and after treatment with 100 µM of various amyloid beta (Aß) peptides (1-40, 1-42, 17-42, 17-40, 1-28, or 1-16). Wild-type N2 C. elegans (strain N2) was cultured on Nematode Growth Medium and directly used, as control, for chemosensory assays. RESULTS: We demonstrated that: (i) G. pallida (unlike Caenorhabditis elegans) assimilates amyloid-ß (Aß) peptides which co-localise with its neurological structures; (ii) pre-treatment with various Aß isoforms (1-40, 1-42, 17-42, 17-40, 1-28, or 1-16) impairs G. pallida's chemotaxis to differing extents; (iii) Aß peptides reduced survival, increased the production of ROS, and increased GSSG/GSH levels in this model; (iv) this unique model can distinguish differences between different treatment concentrations, durations, and modalities, displaying good sensitivity; (v) clinically approved neuroprotective agents were effective in protecting G. pallida from Aß (1-42) exposure. Taken together, the data indicate that G. pallida is an interesting in vivo model with strong potential for discovery of novel bioactive compounds with anti-AD activity.


Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/toxicidade , Animais Geneticamente Modificados/fisiologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Tylenchoidea/fisiologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Quimiotaxia , Tylenchoidea/efeitos dos fármacos
16.
Curr Opin Cell Biol ; 72: 156-162, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500367

RESUMO

Several immune cell types (neutrophils, eosinophils, T cells, and innate-like lymphocytes) display coordinated migration patterns when a population, formed of individually responding cells, moves through inflamed or infected tissues. "Swarming" refers to the process in which a population of migrating leukocytes switches from random motility to highly directed chemotaxis to form local cell clusters. Positive feedback amplification underlies this behavior and results from intercellular communication in the immune cell population. We here highlight recent findings on neutrophil swarming from mouse models, zebrafish larvae, and in vitro platforms for human cells, which together advanced our understanding of the principles and molecular mechanisms that shape immune cell swarming.


Assuntos
Neutrófilos , Peixe-Zebra , Animais , Quimiotaxia , Retroalimentação , Camundongos
17.
Acta Trop ; 224: 106128, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34509454

RESUMO

Visceral leishmaniasis is caused by the protozoan parasite Leishmania donovani. It is a fatal form of leishmaniasis prevalent in Indian subcontinent. Since there are no human licensed vaccines available for leishmaniasis, chemotherapeutic drugs remain the only means for combating parasitic infections. We have earlier identified a total of 26 amino-acyl tRNA synthetases (aaRS) along with five stand-alone editing domains and two aaRS-associated proteins in Leishmania donovani. In addition to their canonical role of tRNA aminoacylation, aaRS have been involved in novel functions by acquiring novel domains during evolution. The aaRS-associated proteins have been reported to be analogous to a human cytokine, EMAP II, as they possess a modified version of the heptapeptide motif responsible for the cytokine activity. In this manuscript, we report the characterization of two L. donovani aminoacyl-tRNA synthetase associated proteins which showed a human chemokine like activity. Both the proteins, L. donovani EMAP-1 and EMAP-2, possess a modified form of the heptapeptide motif, which is responsible for cytokine activity in human EMAP-2. LdEMAP-1 and LdEMAP-2 were cloned, expressed, and purified. Both LdEMAP-1 and LdEMAP-2 proteins in the promastigote stage were found to be localized in cytoplasm as confirmed by immunofluorescence. In case of L. donovani infected human THP-1 derived macrophages, secretion of LdEMAP-1 and LdEMAP-2 proteins in the cytosol of the macrophages was observed. The role of LdEMAP-1 and LdEMAP-2 in the aminoacylation of rLdTyrRS was also tested and LdEMAP-2 but not LdEMAP-1 increased the rate of aminoacylation of tyrosyl tRNA synthetase (rLdTyrRS). L. donovani EMAP-1 and EMAP-2 proteins managed to exhibit the capability of attracting human origin cells as determined by chemotaxis assay, and also were able to induce the secretion of cytokines from macrophages like their human counterpart (EMAP II). Our working hypothesis is that both of these proteins might be involved in helping the parasite to establish the infection within the host.


Assuntos
Aminoacil-tRNA Sintetases , Leishmania donovani , Aminoacil-tRNA Sintetases/genética , Quimiotaxia , Humanos , Monócitos , Proteínas de Protozoários/genética
18.
Biophys J ; 120(20): 4391-4398, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34509505

RESUMO

Flagellated bacteria swim by rotating a bundle of helical flagella and commonly explore the surrounding environment in a "run-and-tumble" motility mode. Here, we show that the upcoming flow could impact the bacterial run-and-tumble behavior by affecting the formation and dispersal of the flagellar bundle. Using a dual optical tweezers setup to trap individual bacteria, we characterized the effects of the imposed fluid flow and cell body rotation on the run-and-tumble behavior. We found that the two factors affect the behavior differently, with the imposed fluid flow increasing the running time and decreasing the tumbling time and the cell body rotation decreasing the tumbling time only. Using numerical simulations, we computed the flagellar bundling time as a function of flow velocity, which agrees well with our experimental observations. The mechanical effects we characterized here provide novel, to our knowledge, ingredients for further studies of bacterial chemotaxis in complex environments such as dynamic fluid environments.


Assuntos
Flagelos , Modelos Biológicos , Quimiotaxia , Pinças Ópticas , Natação
19.
Int J Mol Sci ; 22(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34576243

RESUMO

Fetal bovine serum (FBS) is the only known stimulus for the migration of human neural crest cells (NCCs). Non-animal chemoattractants are desirable for the optimization of chemotaxis as-says to be incorporated in a test battery for reproductive and developmental toxicity. We con-firmed here in an optimized transwell assay that FBS triggers directed migration along a con-centration gradient. The responsible factor was found to be a protein in the 30-100 kDa size range. In a targeted approach, we tested a large panel of serum constituents known to be chem-otactic for NCCs in animal models (e.g., VEGF, PDGF, FGF, SDF-1/CXCL12, ephrins, endothelin, Wnt, BMPs). None of the corresponding human proteins showed any effect in our chemotaxis assays based on human NCCs. We then examined, whether human cells would produce any fac-tor able to trigger NCC migration in a broad screening approach. We found that HepG2 hepa-toma cells produced chemotaxis-triggering activity (CTA). Using chromatographic methods and by employing the NCC chemotaxis test as bioassay, the responsible protein was enriched by up to 5000-fold. We also explored human serum and platelets as a direct source, independent of any cell culture manipulations. A CTA was enriched from platelet lysates several thousand-fold. Its temperature and protease sensitivity suggested also a protein component. The capacity of this factor to trigger chemotaxis was confirmed by single-cell video-tracking analysis of migrating NCCs. The human CTA characterized here may be employed in the future for the setup of assays testing for the disturbance of directed NCC migration by toxicants.


Assuntos
Plaquetas/metabolismo , Fatores Quimiotáticos/metabolismo , Quimiotaxia , Crista Neural/metabolismo , Soroalbumina Bovina/química , Técnicas de Cultura de Células , Diferenciação Celular , Movimento Celular , Proliferação de Células , Células Hep G2 , Humanos , Técnicas In Vitro , Transdução de Sinais
20.
Int J Mol Sci ; 22(17)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34502263

RESUMO

The regulator of G protein signaling (RGS) represents a widespread system of controllers of cellular responses. The activities of the R4 subfamily of RGSs have been elucidated in allergic pulmonary diseases. However, the R4 signaling in other inflammatory lung diseases, with a strong cellular immune response, remained unexplored. Thus, our study aimed to discern the functional relevance of the R4 family member, RGS5, as a potential modulating element in this context. Gene profiling of the R4 subfamily showed increased RGS5 expression in human fibrosing lung disease samples. In line with this, RGS5 was markedly increased in murine lungs following bleomycin injury. RGS knock-out mice (RGS-/-) had preserved lung function while control mice showed significant combined ventilatory disorders three days after bleomycin application as compared to untreated control mice. Loss of RGS5 was associated with a significantly reduced neutrophil influx and tissue myeloperoxidase expression. In the LPS lung injury model, RGS5-/- mice also failed to recruit neutrophils into the lung, which was accompanied by reduced tissue myeloperoxidase levels after 24 h. Our in-vitro assays showed impaired migration of RGS5-/- neutrophils towards chemokines despite preserved Ca2+ signaling. ERK dephosphorylation might play a role in reduced neutrophil migration in our model. As a conclusion, loss of RGS5 preserves lung function and attenuates hyperinflammation in the acute phase of bleomycin-induced pulmonary fibrosis and LPS-induced lung injury. Targeting RGS5 might alleviate the severity of exacerbations in interstitial lung diseases.


Assuntos
Inflamação/metabolismo , Lesão Pulmonar/metabolismo , Neutrófilos/metabolismo , Proteínas RGS/genética , Proteínas RGS/metabolismo , Animais , Bleomicina/toxicidade , Quimiotaxia/genética , Modelos Animais de Doenças , Fibrose/genética , Humanos , Inflamação/induzido quimicamente , Lipopolissacarídeos/toxicidade , Doenças Pulmonares Intersticiais/genética , Doenças Pulmonares Intersticiais/metabolismo , Doenças Pulmonares Intersticiais/patologia , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/patologia , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Knockout , Neutrófilos/citologia , Proteínas RGS/deficiência , Síndrome do Desconforto Respiratório/genética , Síndrome do Desconforto Respiratório/metabolismo
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