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Nature Nov 2015Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and...
Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6β4 and α6β1 were associated with lung metastasis, while exosomal integrin αvβ5 was linked to liver metastasis. Targeting the integrins α6β4 and αvβ5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.
Topics: Animals; Biomarkers; Brain; Cell Line, Tumor; Endothelial Cells; Epithelial Cells; Exosomes; Female; Fibroblasts; Genes, src; Humans; Integrin alpha6beta1; Integrin alpha6beta4; Integrin beta Chains; Integrin beta4; Integrins; Kupffer Cells; Liver; Lung; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Organ Specificity; Phosphorylation; Receptors, Vitronectin; S100 Proteins; Tropism
PubMed: 26524530
DOI: 10.1038/nature15756 -
Neuron May 2022Endothelial cells of blood vessels of the central nervous system (CNS) constitute blood-CNS barriers. Barrier properties are not intrinsic to these cells; rather they...
Endothelial cells of blood vessels of the central nervous system (CNS) constitute blood-CNS barriers. Barrier properties are not intrinsic to these cells; rather they are induced and maintained by CNS microenvironment. Notably, the abluminal surfaces of CNS capillaries are ensheathed by pericytes and astrocytes. However, extrinsic factors from these perivascular cells that regulate barrier integrity are largely unknown. Here, we establish vitronectin, an extracellular matrix protein secreted by CNS pericytes, as a regulator of blood-CNS barrier function via interactions with its integrin receptor, α5, in endothelial cells. Genetic ablation of vitronectin or mutating vitronectin to prevent integrin binding, as well as endothelial-specific deletion of integrin α5, causes barrier leakage in mice. Furthermore, vitronectin-integrin α5 signaling maintains barrier integrity by actively inhibiting transcytosis in endothelial cells. These results demonstrate that signaling from perivascular cells to endothelial cells via ligand-receptor interactions is a key mechanism to regulate barrier permeability.
Topics: Animals; Blood-Brain Barrier; Central Nervous System; Endothelial Cells; Integrin alpha5; Integrins; Mice; Pericytes; Vitronectin
PubMed: 35294899
DOI: 10.1016/j.neuron.2022.02.017 -
Journal of Neuroinflammation Apr 2022Neuroinflammation is a crucial factor in the development of secondary brain injury after intracerebral hemorrhage (ICH). Irisin is a newly identified myokine that...
BACKGROUND
Neuroinflammation is a crucial factor in the development of secondary brain injury after intracerebral hemorrhage (ICH). Irisin is a newly identified myokine that confers strong neuroprotective effects in experimental ischemic stroke. However, whether this myokine can exert neuroprotection effects after ICH remains unknown. This study aimed to investigate the impact of irisin treatment on neuroinflammation and neuronal apoptosis and the underlying mechanism involving integrin αVβ5/AMPK pathway after ICH.
METHODS
Two hundred and eighty-five adult (8-week-old) male C57BL/6 mice were randomly assigned to sham and ICH surgery groups. ICH was induced via intrastriatal injection of autologous blood. Irisin was administered intranasally at 30 min after ICH. To elucidate the underlying mechanism, cilengitide (a selective integrin αVβ5 inhibitor) and dorsomorphin (a selective phosphorylated AMPK inhibitor) were administered before irisin treatment. The short- and long-term neurobehavior tests, brain edema, quantitative-PCR, western blotting, Fluoro-Jade C, TUNEL, and immunofluorescence staining were performed to assess the neurofunctional outcome at the level of molecular, cell, histology, and function.
RESULTS
Endogenous irisin and its receptor, integrin αVβ5, were increased, peaked at 24 h after ICH. irisin post-treatment improved both short- and long-term neurological functions, reduced brain edema after ICH. Interestingly, integrin αVβ5 was mainly located in the microglia after ICH, and irisin post-treatment inhibited microglia/macrophage pro-inflammatory polarization and promoted anti-inflammatory polarization. Moreover, irisin treatment inhibited neutrophil infiltration and suppressed neuronal apoptotic cell death in perihematomal areas after ICH. Mechanistically, irisin post-treatment significantly increased the expression of integrin αVβ5, p-AMPK and Bcl-2, and decreased the expression of IL-1β, TNF-α, MPO, and Bax following ICH. The neuroprotective effects of irisin were abolished by both integrin αVβ5 inhibitor cilengitide and AMPK inhibitor dorsomorphin.
CONCLUSIONS
This study demonstrated that irisin post-treatment ameliorated neurological deficits, reduced brain edema, and ameliorated neuroinflammation and neuronal apoptosis, at least in part, through the integrin αVβ5/AMPK signaling pathway after ICH. Thus, irisin post-treatment may provide a promising therapeutic approach for the early management of ICH.
Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Brain Edema; Cerebral Hemorrhage; Fibronectins; Male; Mice; Mice, Inbred C57BL; Neuroinflammatory Diseases; Neuroprotective Agents; Receptors, Vitronectin; Signal Transduction
PubMed: 35392928
DOI: 10.1186/s12974-022-02438-6 -
Cell Stem Cell Feb 2020Zika virus (ZIKV) causes microcephaly by killing neural precursor cells (NPCs) and other brain cells. ZIKV also displays therapeutic oncolytic activity against...
Zika virus (ZIKV) causes microcephaly by killing neural precursor cells (NPCs) and other brain cells. ZIKV also displays therapeutic oncolytic activity against glioblastoma (GBM) stem cells (GSCs). Here we demonstrate that ZIKV preferentially infected and killed GSCs and stem-like cells in medulloblastoma and ependymoma in a SOX2-dependent manner. Targeting SOX2 severely attenuated ZIKV infection, in contrast to AXL. As mechanisms of SOX2-mediated ZIKV infection, we identified inverse expression of antiviral interferon response genes (ISGs) and positive correlation with integrin α (ITGAV). ZIKV infection was disrupted by genetic targeting of ITGAV or its binding partner ITGB5 and by an antibody specific for integrin αβ. ZIKV selectively eliminated GSCs from species-matched human mature cerebral organoids and GBM surgical specimens, which was reversed by integrin αβ inhibition. Collectively, our studies identify integrin αβ as a functional cancer stem cell marker essential for GBM maintenance and ZIKV infection, providing potential brain tumor therapy.
Topics: Glioblastoma; Humans; Neural Stem Cells; Receptors, Vitronectin; SOXB1 Transcription Factors; Zika Virus; Zika Virus Infection
PubMed: 31956038
DOI: 10.1016/j.stem.2019.11.016 -
Theranostics 2022In the glioblastoma (GBM) microenvironment, tumor-associated macrophages (TAMs) are prominent components and facilitate tumor growth. The exact molecular mechanisms...
In the glioblastoma (GBM) microenvironment, tumor-associated macrophages (TAMs) are prominent components and facilitate tumor growth. The exact molecular mechanisms underlying TAMs' function in promoting glioma stem cells (GSCs) maintenance and tumor growth remain largely unknown. We found a candidate molecule, transforming growth factor beta-induced (TGFBI), that was specifically expressed by TAMs and extremely low in GBM and GSC cells, and meanwhile closely related to glioma WHO grades and patient prognosis. The exact mechanism of TGFBI linking TAM functions to GSC-driven tumor growth was explored. Western blot, quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), immunofluorescence (IF), immunohistochemistry staining (IHC) and public datasets were used to evaluate TGFBI origin and level in GBM. The response of GSCs to recombinant human TGFBI was assessed and orthotopic xenografts were established to investigate the function and mechanism . M2-like TAMs infiltration was elevated in high-grade gliomas. TGFBI was preferentially secreted by M2-like TAMs and associated with a poor prognosis for patients with GBM. TGFBI promoted the maintenance of GSCs and GBM malignant growth through integrin αvβ5-Src-Stat3 signaling and . Of clinical relevance, TGFBI was enriched in the serum and CSF of GBM patients and significantly decreased after tumor resection. TAM-derived TGFBI promotes GSC-driven tumor growth through integrin αvβ5-Src-Stat3 signaling. High serum or CSF TGFBI may serve as a potential diagnostic and prognostic bio-index for GBMs.
Topics: Brain Neoplasms; Cell Line, Tumor; Glioblastoma; Glioma; Humans; Neoplastic Stem Cells; Receptors, Vitronectin; STAT3 Transcription Factor; Transforming Growth Factor beta; Tumor Microenvironment; Tumor-Associated Macrophages
PubMed: 35673564
DOI: 10.7150/thno.69605 -
Cancer Cell Jan 2019Triple-negative breast cancer (TNBC) patients have the worst prognosis and distant metastasis-free survival among all major subtypes of breast cancer. The poor clinical...
Triple-negative breast cancer (TNBC) patients have the worst prognosis and distant metastasis-free survival among all major subtypes of breast cancer. The poor clinical outlook is further exacerbated by a lack of effective targeted therapies for TNBC. Here we show that ectopic expression and therapeutic delivery of the secreted protein Tubulointerstitial nephritis antigen-like 1 (Tinagl1) suppresses TNBC progression and metastasis through direct binding to integrin α5β1, αvβ1, and epidermal growth factor receptor (EGFR), and subsequent simultaneous inhibition of focal adhesion kinase (FAK) and EGFR signaling pathways. Moreover, Tinagl1 protein level is associated with good prognosis and reversely correlates with FAK and EGFR activation status in TNBC. Our results suggest Tinagl1 as a candidate therapeutic agent for TNBC by dual inhibition of integrin/FAK and EGFR signaling pathways.
Topics: Animals; Biomarkers, Tumor; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Progression; ErbB Receptors; Extracellular Matrix Proteins; Female; Focal Adhesion Kinase 1; Gene Expression Regulation, Neoplastic; Humans; Integrin alpha5beta1; Lipocalins; Lung Neoplasms; Mice; Prognosis; Receptors, Vitronectin; Signal Transduction; Triple Negative Breast Neoplasms
PubMed: 30612941
DOI: 10.1016/j.ccell.2018.11.016 -
The Journal of Clinical Investigation Jan 2019Glioblastoma is highly enriched with macrophages, and osteopontin (OPN) expression levels correlate with glioma grade and the degree of macrophage infiltration; thus, we...
Glioblastoma is highly enriched with macrophages, and osteopontin (OPN) expression levels correlate with glioma grade and the degree of macrophage infiltration; thus, we studied whether OPN plays a crucial role in immune modulation. Quantitative PCR, immunoblotting, and ELISA were used to determine OPN expression. Knockdown of OPN was achieved using complementary siRNA, shRNA, and CRISPR/Cas9 techniques, followed by a series of in vitro functional migration and immunological assays. OPN gene-deficient mice were used to examine the roles of non-tumor-derived OPN on survival of mice harboring intracranial gliomas. Patients with mesenchymal glioblastoma multiforme (GBM) show high OPN expression, a negative survival prognosticator. OPN is a potent chemokine for macrophages, and its blockade significantly impaired the ability of glioma cells to recruit macrophages. Integrin αvβ5 (ITGαvβ5) is highly expressed on glioblastoma-infiltrating macrophages and constitutes a major OPN receptor. OPN maintains the M2 macrophage gene signature and phenotype. Both tumor-derived and host-derived OPN were critical for glioma development. OPN deficiency in either innate immune or glioma cells resulted in a marked reduction in M2 macrophages and elevated T cell effector activity infiltrating the glioma. Furthermore, OPN deficiency in the glioma cells sensitized them to direct CD8+ T cell cytotoxicity. Systemic administration in mice of 4-1BB-OPN bispecific aptamers was efficacious, increasing median survival time by 68% (P < 0.05). OPN is thus an important chemokine for recruiting macrophages to glioblastoma, mediates crosstalk between tumor cells and the innate immune system, and has the potential to be exploited as a therapeutic target.
Topics: Animals; Aptamers, Nucleotide; Brain Neoplasms; CD8-Positive T-Lymphocytes; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glioblastoma; Humans; Immunity, Cellular; Immunity, Innate; Macrophages; Male; Mice; Mice, Knockout; Neoplasm Proteins; Osteopontin; Receptors, Vitronectin
PubMed: 30307407
DOI: 10.1172/JCI121266 -
Theranostics 2023: Renal infiltration of inflammatory cells including macrophages is a crucial event in kidney fibrogenesis. However, how macrophage regulates fibroblast activation in...
: Renal infiltration of inflammatory cells including macrophages is a crucial event in kidney fibrogenesis. However, how macrophage regulates fibroblast activation in the fibrotic kidney remains elusive. In this study, we show that macrophages promoted fibroblast activation by assembling a vitronectin (Vtn)-enriched, extracellular microenvironment. : We prepared decellularized kidney tissue scaffold (KTS) from normal and fibrotic kidney after unilateral ischemia-reperfusion injury (UIRI) and carried out an unbiased quantitative proteomics analysis. NRK-49F cells were seeded on macrophage-derived extracellular matrix (ECM) scaffold. Genetic Vtn knockout (Vtn-/-) mice and chronic kidney disease (CKD) model with overexpression of Vtn were used to corroborate a role of Vtn/integrin αvβ5/Src in kidney fibrosis. : Vtn was identified as one of the most upregulated proteins in the decellularized kidney tissue scaffold from fibrotic kidney by mass spectrometry. Furthermore, Vtn was upregulated in the kidney of mouse models of CKD and primarily expressed and secreted by activated macrophages. Urinary Vtn levels were elevated in CKD patients and inversely correlated with kidney function. Genetic ablation or knockdown of Vtn protected mice from developing kidney fibrosis after injury. Conversely, overexpression of Vtn exacerbated renal fibrotic lesions and aggravated renal insufficiency. We found that macrophage-derived, Vtn-enriched extracellular matrix scaffold promoted fibroblast activation and proliferation. In vitro, Vtn triggered fibroblast activation by stimulating integrin αvβ5 and Src kinase signaling. Either blockade of αvβ5 with neutralizing antibody or pharmacological inhibition of Src by Saracatinib abolished Vtn-induced fibroblast activation. Moreover, Saracatinib dose-dependently ameliorated Vtn-induced kidney fibrosis in vivo. These results demonstrate that macrophage induces fibroblast activation by assembling a Vtn-enriched extracellular microenvironment, which triggers integrin αvβ5 and Src kinase signaling. : Our findings uncover a novel mechanism by which macrophages contribute to kidney fibrosis via assembling a Vtn-enriched extracellular niche and suggest that disrupting fibrogenic microenvironment could be a therapeutic strategy for fibrotic CKD.
Topics: Mice; Animals; Vitronectin; Kidney; Renal Insufficiency, Chronic; src-Family Kinases; Macrophages; Fibroblasts; Fibrosis
PubMed: 37441594
DOI: 10.7150/thno.85250 -
Respiratory Research Oct 2021α integrins, key regulators of transforming growth factor-β activation and fibrogenesis in in vivo models of pulmonary fibrosis, are expressed on abnormal epithelial...
RATIONALE
α integrins, key regulators of transforming growth factor-β activation and fibrogenesis in in vivo models of pulmonary fibrosis, are expressed on abnormal epithelial cells (αβ) and fibroblasts (αβ) in fibrotic lungs.
OBJECTIVES
We evaluated multiple α integrin inhibition strategies to assess which most effectively reduced fibrogenesis in explanted lung tissue from patients with idiopathic pulmonary fibrosis.
METHODS
Selective αβ and αβ, dual αβ/αβ, and multi-α integrin inhibitors were characterized for potency, selectivity, and functional activity by ligand binding, cell adhesion, and transforming growth factor-β cell activation assays. Precision-cut lung slices generated from lung explants from patients with idiopathic pulmonary fibrosis or bleomycin-challenged mouse lungs were treated with integrin inhibitors or standard-of-care drugs (nintedanib or pirfenidone) and analyzed for changes in fibrotic gene expression or TGF-β signaling. Bleomycin-challenged mice treated with dual αβ/αβ integrin inhibitor, PLN-74809, were assessed for changes in pulmonary collagen deposition and Smad3 phosphorylation.
MEASUREMENTS AND MAIN RESULTS
Inhibition of integrins αβ and αβ was additive in reducing type I collagen gene expression in explanted lung tissue slices from patients with idiopathic pulmonary fibrosis. These data were replicated in fibrotic mouse lung tissue, with no added benefit observed from inhibition of additional α integrins. Antifibrotic efficacy of dual αβ/αβ integrin inhibitor PLN-74809 was confirmed in vivo, where dose-dependent inhibition of pulmonary Smad3 phosphorylation and collagen deposition was observed. PLN-74809 also, more potently, reduced collagen gene expression in fibrotic human and mouse lung slices than clinically relevant concentrations of nintedanib or pirfenidone.
CONCLUSIONS
In the fibrotic lung, dual inhibition of integrins αβ and αβ offers the optimal approach for blocking fibrogenesis resulting from integrin-mediated activation of transforming growth factor-β.
Topics: Animals; Antifibrotic Agents; Bleomycin; Cell Line; Coculture Techniques; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Epithelial Cells; Fibroblasts; Humans; Idiopathic Pulmonary Fibrosis; Integrin alpha6beta1; Lung; Mice, Inbred C57BL; Phosphorylation; Receptors, Vitronectin; Signal Transduction; Smad3 Protein; Mice
PubMed: 34666752
DOI: 10.1186/s12931-021-01863-0 -
Journal of Biomedical Materials... Oct 2018Fibrinogen (Fg) adsorption is an important mechanism underlying cell adhesion to biomaterials and was the major focus of the author's research career. This article... (Review)
Review
Fibrinogen (Fg) adsorption is an important mechanism underlying cell adhesion to biomaterials and was the major focus of the author's research career. This article summarizes our work on Fg adsorption, with citations of related work as appropriate. The molecular properties of Fg that promote adsorption and cell adhesion will be described. In addition, the adsorption behavior of Fg from buffer, binary solutions with other proteins, and blood plasma will be discussed, including the Vroman effect. Studies of platelet adhesion to surfaces preadsorbed with blood plasmas selectively deficient in Fg, vitronectin (Vn), fibronectin (Fn), or von Willebrand's factor (vWf) will be reviewed. These studies clearly showed a major role for Fg in platelet adhesion under static conditions and both Fg and vWf for adhesion from flowing suspensions, but no significant role for Vn or Fn. However, it was also shown that platelet adhesion was poorly correlated with the total amount of adsorbed Fg, but very well correlated with the binding of antibodies specific to the cell binding domains of Fg. A brief overview of nonfouling surfaces for prevention of Fg adsorption will be given. A more extensive discussion of structural changes in Fg after its adsorption is included, including changes detected with both physicochemical and biological methods. A short discussion of the state of the art of structural determination of adsorbed proteins with computational methods is also given. A final section identifies Fg adsorption as the single most important event determining the biocompatibility of implants in soft tissue and in blood. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2777-2788, 2018.
Topics: Adsorption; Animals; Biocompatible Materials; Biofouling; Fibrinogen; Humans; Monocytes; Platelet Adhesiveness
PubMed: 29896846
DOI: 10.1002/jbm.a.36460