Actin polymerization stabilizes a4b1 integrin anchors that mediate monocyte adhesion

Rullo, Jacob; Becker, Henry; Hyduk, Sharon J.; Wong, Janice; Digby, Geneviève C.; Arora, Pamma D.; Cano, Adrianet Puig; Hartwig, John H.; McCulloch, Christopher A.; Cybulsky, Myron I.

doi:10.1084/jem2094oia4

Cited by 3 publications

(12 citation statements)

References 15 publications

(13 reference statements)

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“…This requires tethered monocytes to resist detachment caused by forces transmitted by flowing blood. Stabilization of monocyte anchors is dependent on actin cytoskeletal rearrangements and activation of Rac (11). Thus, a strategy to simultaneously block chemotaxis of monocytes to different attractants, as well as postadhesion stabilization of monocytes tethered to inflamed endothelium, could prove highly effective in preventing vascular inflammation.…”

Section: †mentioning

confidence: 99%

“…Monocytes were isolated from the blood of healthy volunteers using Polymorphprep gradient separation solution (Axis-Shield, Oslo, Norway) and an EasySep Negative Selection Kit (STEMCELL Technologies) (11). Cell viability was determined to be .98% by trypan blue staining.…”

Section: Isolation Of Human and Mouse Monocytes And Pbmcmentioning

confidence: 99%

“…In some experiments, PBMC were isolated from the blood of patients with CAD or from healthy age-and sex-matched controls by Ficoll gradient centrifugation (11). Informed consent for study participation was obtained from all patients and healthy volunteers.…”

Section: Isolation Of Human and Mouse Monocytes And Pbmcmentioning

confidence: 99%

“…Monocyte-accumulation and -detachment assays were performed as previously described (11,23). Leukocytes were incubated with Slit2 (30 nM), latrunculin B (LatB; 2 mM), or control vehicle.…”

Section: Bioflux Microfluidics Assaysmentioning

confidence: 99%

“…After static adhesion, shear force was introduced and incrementally increased by 1 dyn/cm 2 at 10-s intervals from 1 to 10 dyn/cm 2 and then increased incrementally by 5 dyn/cm 2 . The number of cells remaining adherent after each interval was determined using BioFlux acquisition software (11).…”

Section: Bioflux Microfluidics Assaysmentioning

confidence: 99%

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The Neurorepellent Slit2 Inhibits Postadhesion Stabilization of Monocytes Tethered to Vascular Endothelial Cells

Mukovozov

Huang

Zhang

et al. 2015

The Journal of Immunology

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The secreted neurorepellent Slit2, acting through its transmembrane receptor, Roundabout (Robo)-1, inhibits chemotaxis of varied cell types, including leukocytes, endothelial cells, and vascular smooth muscle cells, toward diverse attractants. The role of Slit2 in regulating the steps involved in recruitment of monocytes in vascular inflammation is not well understood. In this study, we showed that Slit2 inhibited adhesion of monocytic cells to activated human endothelial cells, as well as to immobilized ICAM-1 and VCAM-1. Microfluidic live cell imaging showed that Slit2 inhibited the ability of monocytes tethered to endothelial cells to stabilize their actin-associated anchors and to resist detachment in response to increasing shear forces. Transfection of constitutively active plasmids revealed that Slit2 inhibited postadhesion stabilization of monocytes on endothelial cells by preventing activation of Rac1. We further found that Slit2 inhibited chemotaxis of monocytes toward CXCL12 and CCL2. To determine whether Slit2 and Robo-1 modulate pathologic monocyte recruitment associated with vascular inflammation and cardiovascular disease, we tested PBMC from patients with coronary artery disease. PBMC from these patients had reduced surface levels of Robo-1 compared with healthy age- and sex-matched subjects, and Slit2 failed to inhibit chemotaxis of PBMC of affected patients, but not healthy control subjects, toward CCL2. Furthermore, administration of Slit2 to atherosclerosis-prone LDL receptor–deficient mice inhibited monocyte recruitment to nascent atherosclerotic lesions. These results demonstrate that Slit2 inhibits chemotaxis of monocytes, as well as their ability to stabilize adhesions and resist detachment forces. Slit2 may represent a powerful new tool to inhibit pathologic monocyte recruitment in vascular inflammation and atherosclerosis.

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Section: †mentioning

confidence: 99%

Section: Isolation Of Human and Mouse Monocytes And Pbmcmentioning

confidence: 99%

Section: Isolation Of Human and Mouse Monocytes And Pbmcmentioning

confidence: 99%

“…Monocyte-accumulation and -detachment assays were performed as previously described (11,23). Leukocytes were incubated with Slit2 (30 nM), latrunculin B (LatB; 2 mM), or control vehicle.…”

Section: Bioflux Microfluidics Assaysmentioning

confidence: 99%

Section: Bioflux Microfluidics Assaysmentioning

confidence: 99%

See 3 more Smart Citations

The Neurorepellent Slit2 Inhibits Postadhesion Stabilization of Monocytes Tethered to Vascular Endothelial Cells

Mukovozov

Huang

Zhang

et al. 2015

The Journal of Immunology

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Topographic cues of a novel bilayered scaffold modulate dental pulp stem cells differentiation by regulating YAP signalling through cytoskeleton adjustments

Montoya

Orrego

et al. 2019

Cell Proliferation

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Objectives Topographic cues can modulate morphology and differentiation of mesenchymal stem cells. This study aimed to determine how topographic cues of a novel bilayered poly (lactic‐co‐glycolic acid) (PLGA) scaffold affect osteogenic/odontogenic differentiation of dental pulp stem cells (DPSCs). Methods The surface morphology of the scaffolds was visualized by scanning electron microscope, and the surface roughness was measured by profilometry. DPSCs were cultured on each side of the scaffolds. Cell morphology, expression of Yes‐associated protein (YAP) and osteogenic/odontogenic differentiation were analysed by immunohistochemistry, real‐time polymerase chain reaction, and Alizarin Red S staining. In addition, cytochalasin D (CytoD), an F‐actin disruptor, was used to examine the effects of F‐actin on intracellular YAP localisation. Verteporfin, a YAP transcriptional inhibitor, was used to explore the effects of YAP signalling on osteogenic/odontogenic differentiation of DPSCs. Results The closed side of our scaffold showed smaller pores and less roughness than the open side. On the closed side, DPSCs exhibited enhanced F‐actin stress fibre alignment, larger spreading area, more elongated appearance, predominant nuclear YAP localization and spontaneous osteogenic differentiation. Inhibition of F‐actin alignments was correlated with nuclear YAP exclusion of DPSCs. Verteporfin restricted YAP localisation to the cytoplasm, down‐regulated expression of early osteogenic/odontogenic markers and inhibited mineralization of DPSCs cultures. Conclusions The surface topographic cues changed F‐actin alignment and morphology of DPSCs, which in turn regulated YAP signalling to control osteogenic/odontogenic differentiation.

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Toxoplasma gondii modulates the dynamics of human monocyte adhesion to vascular endothelium under fluidic shear stress

Harker

Ueno

Wang

et al. 2013

Journal of Leukocyte Biology

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Toxoplasma gondii actively infects circulating immune cells, including monocytes and DCs, and is thought to use these cells as Trojan horses for parasite dissemination. To investigate the interactions of T. gondii-infected human monocytes with vascular endothelium under conditions of shear stress, we developed a fluidic and time-lapse fluorescence microscopy system. Both uninfected and infected monocytes rolled, decelerated, and firmly adhered on TNF-α-activated endothelium. Interestingly, T. gondii-infected primary human monocytes and THP-1 cells exhibited altered adhesion dynamics compared with uninfected monocytes: infected cells rolled at significantly higher velocities (2.5- to 4.6-fold) and over greater distances (2.6- to 4.8-fold) than uninfected monocytes, before firmly adhering. During monocyte searching, 29-36% of infected monocytes compared with 0-11% of uninfected monocytes migrated >10 μm from the point where they initiated searching, and these "wandering" searches were predominantly in the direction of flow. As infected monocytes appeared delayed in their transition to firm adhesion, we examined the effects of infection on integrin expression and function. T. gondii did not affect the expression of LFA-1, VLA-4, or MAC-1 or the ability of Mn(2+) to activate these integrins. However, T. gondii infection impaired LFA-1 and VLA-4 clustering and pseudopod extension in response to integrin ligands. Surprisingly, a single intracellular parasite was sufficient to mediate these effects. This research has established a system for studying pathogen modulation of human leukocyte adhesion under conditions of physiological shear stress and has revealed a previously unappreciated effect of T. gondii infection on ligand-dependent integrin clustering.

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Actin polymerization stabilizes a4b1 integrin anchors that mediate monocyte adhesion

Cited by 3 publications

References 15 publications

The Neurorepellent Slit2 Inhibits Postadhesion Stabilization of Monocytes Tethered to Vascular Endothelial Cells

The Neurorepellent Slit2 Inhibits Postadhesion Stabilization of Monocytes Tethered to Vascular Endothelial Cells

Topographic cues of a novel bilayered scaffold modulate dental pulp stem cells differentiation by regulating YAP signalling through cytoskeleton adjustments

Toxoplasma gondii modulates the dynamics of human monocyte adhesion to vascular endothelium under fluidic shear stress

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