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Abstract
The term "lectin" is derived from the Latin word lego- (aggregate) (Boyd & Shapleigh, 1954). Indeed, lectins' folds can flexibly alter their pocket structures just like Lego blocks, which enables them to grab a wide-variety of substances. Thus, this useful fold is well-conserved among various organisms. Through evolution, prototypic soluble lectins acquired transmembrane regions and signaling motifs to become C-type lectin receptors (CLRs). While CLRs seem to possess certain intrinsic affinity to self, some CLRs adapted to efficiently recognize glycoconjugates present in pathogens as pathogen-associated molecular patterns (PAMPs) and altered self. CLRs further extended their diversity to recognize non-glycosylated targets including pathogens and self-derived molecules. Thus, CLRs seem to have developed to monitor the internal/external stresses to maintain homeostasis by sensing various "unfamiliar" targets. In this review, we will summarize recent advances in our understanding of CLRs, their ligands and functions and discuss future perspectives.
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Affiliation(s)
- Carla Guenther
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan; Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Masamichi Nagae
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan; Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Sho Yamasaki
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan; Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.
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Osaki T, Serrano JC, Kamm RD. Cooperative Effects of Vascular Angiogenesis and Lymphangiogenesis. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2018; 4:120-132. [PMID: 30417074 DOI: 10.1007/s40883-018-0054-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In this study, we modeled lymphangiogenesis and vascular angiogenesis in a microdevice using a tissue engineering approach. Lymphatic vessels (LV) and blood vessels (BV) were fabricated by sacrificial molding with seeding human lymphatic endothelial cells and human umbilical vein endothelial cells into molded microchannels (600 μm diameter). During subsequent perfusion culture, lymphangiogenesis and vascular angiogenesis were induced by addition of phorbol 12-myristate 13-acetate (PMA) and VEGF-C or VEGF-A characterized by podoplanin and Prox-1 expression. The lymphatic capillaries formed button-like junctions treated with dexamethasone. To test the potential for screening anti-angiogenic (vascular and lymphatic) factors, antagonists of VEGF were introduced. We found that an inhibitor of VEGF-R3 did not completely suppress lymphatic angiogenesis with BVs present, although lymphatic angiogenesis was selectively prevented by addition of a VEGF-R3 inhibitor without BVs. To probe the mechanism of action, we focus on matrix metalloproteinase (MMP) secretion by vascular endothelial cells and lymphatic endothelial cells under monoculture or co-culture conditions. We found that vascular angiogenesis facilitated lymphangiogenesis via remodeling of the local microenvironment by the increased secretion of MMP, mainly by endothelial cells. Applications of this model include a drug screening assay for corneal disease and models for tumorigenesis including lymphatic angiogenesis and vascular angiogenesis.
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Affiliation(s)
- Tatsuya Osaki
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jean C Serrano
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Roger D Kamm
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,BioSystems and Micromechanics (BioSyM), Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
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Guo H, Kazadaeva Y, Ortega FE, Manjunath N, Desai TJ. Trinucleotide repeat containing 6c (TNRC6c) is essential for microvascular maturation during distal airspace sacculation in the developing lung. Dev Biol 2017; 430:214-223. [PMID: 28811219 PMCID: PMC5634525 DOI: 10.1016/j.ydbio.2017.07.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/25/2017] [Accepted: 07/25/2017] [Indexed: 01/09/2023]
Abstract
GW182 (also known asTNRC6) family members are critically involved in the final effector phase of miRNA-mediated mRNA repression. The three mammalian paralogs, TNRC6a, b and c, are thought to be redundant based on Argonaute (Ago) binding, tethering assays, and RNAi silencing of individual members in cell lines. To test this idea, we generated TNRC6a, b and c knockout mice. TNRC6a mutants die at mid-gestation, while b- and c- deleted mice are born at a Mendelian ratio. However, the majority of TNRC6b and all TNRC6c mutants die within 24h after birth, the latter with respiratory failure. Necropsy of TNRC6c mutants revealed normal-appearing airways that give rise to abnormally thick-walled distal gas exchange sacs. Immunohistological analysis of mutant lungs demonstrated a normal distribution of bronchiolar and alveolar cells, indicating that loss of TNRC6c did not abrogate epithelial cell differentiation. The cellular kinetics and relative proportions of endothelial, epithelial, and mesenchymal cells were also not altered. However, the underlying capillary network was simplified and endothelial cells had failed to become tightly apposed to the surface epithelium in TNRC6c mutants, presumably causing the observed respiratory failure. TGFβ family mutant mice exhibit a similar lung phenotype of thick-walled air sacs and neonatal lethality, and qRT-PCR confirmed dynamic downregulation of TGFβ1 and TGFβR2 in TNRC6c mutant lungs during sacculation. VEGFR, but not VEGF-A ligand, was also lower, likely reflecting the overall reduced capillary density in TNRC6c mutants. Together, these results demonstrate that GW182 paralogs are not functionally redundant in vivo. Surprisingly, despite regulating a general cellular process, TNRC6c is selectively required only in the distal lung and not until late in gestation for proper expression of the TGFβ family genes that drive sacculation. These results imply a complex and indirect mode of regulation of sacculation by TNRC6c, mediated in part by dynamic transcriptional repression of an inhibitor of TGFβ family gene expression.
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Affiliation(s)
- Hua Guo
- Center of Emphasis in Infectious Disease, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX 79905, United States
| | - Yana Kazadaeva
- Department of Internal Medicine, Division of Pulmonary and Critical Care, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Fabian E Ortega
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Narasimaswamy Manjunath
- Center of Emphasis in Infectious Disease, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX 79905, United States
| | - Tushar J Desai
- Department of Internal Medicine, Division of Pulmonary and Critical Care, Stanford University School of Medicine, Stanford, CA 94305, United States.
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Angiopoietins as serum biomarkers for lymphatic anomalies. Angiogenesis 2016; 20:163-173. [PMID: 27990590 DOI: 10.1007/s10456-016-9537-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 12/03/2016] [Indexed: 01/08/2023]
Abstract
Vascular anomalies can cause significant morbidity and mortality. Advances in diagnosis will be improved if noninvasive biomarkers can be identified, as obtaining a tissue biopsy can worsen the disease and precipitate complications. The goal of this study was to identify biomarkers for vascular anomaly patients to aid diagnosis and potentially give insights into pathogenesis. Blood was collected at baseline and then 6 and 12 months after treatment with the mTOR inhibitor sirolimus. Patients groups included generalized lymphatic anomaly (GLA), kaposiform lymphangiomatosis (KLA) and kaposiform hemangioendothelioma (KHE) with or without the Kasabach-Merritt phenomenon (KMP) coagulopathy. Serum was obtained from healthy controls selected to match the age and sex of the patients (21 days-28.5 years; 42% males; 58% females). Angiogenic and lymphangiogenic factors (VEGF-A, C, D, Ang-1 and Ang-2) were measured in serum using ELISA. In lymphatic anomaly patients, baseline levels of VEGF-A and VEGF-D were not different compared to controls. Angiopoietin-2 (Ang-2) levels were near controls levels in GLA patients but 10-fold greater in KLA patients and 14-fold greater in KHE patients when the KMP coagulopathy was present but not when it was absent. VEGF-C and angiopoietin-1 (Ang-1) levels were lower in KHE patients with KMP. Our analyses suggest that Ang-2 and Ang-1 can be used as biomarkers to help identify KLA and KHE patients with KMP coagulopathy with high sensitivity and specificity. After 12 months of sirolimus treatment, Ang-2 levels were lower in KLA and KHE with KMP patients compared to baseline levels and with most patients showing a clinical response. Hence, serum Ang-2 and Ang-1 levels may help in the diagnosis of patients with lymphatic anomalies and are concordant to sirolimus response.
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Mitsi M, Schulz MMP, Gousopoulos E, Ochsenbein AM, Detmar M, Vogel V. Walking the Line: A Fibronectin Fiber-Guided Assay to Probe Early Steps of (Lymph)angiogenesis. PLoS One 2015; 10:e0145210. [PMID: 26689200 PMCID: PMC4686943 DOI: 10.1371/journal.pone.0145210] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 12/01/2015] [Indexed: 11/24/2022] Open
Abstract
Angiogenesis and lymphangiogenesis are highly complex morphogenetic processes, central to many physiological and pathological conditions, including development, cancer metastasis, inflammation and wound healing. While it is described that extracellular matrix (ECM) fibers are involved in the spatiotemporal regulation of angiogenesis, current angiogenesis assays are not specifically designed to dissect and quantify the underlying molecular mechanisms of how the fibrillar nature of ECM regulates vessel sprouting. Even less is known about the role of the fibrillar ECM during the early stages of lymphangiogenesis. To address such questions, we introduced here an in vitro (lymph)angiogenesis assay, where we used microbeads coated with endothelial cells as simple sprouting sources and deposited them on single Fn fibers used as substrates to mimic fibrillar ECM. The fibers were deposited on a transparent substrate, suitable for live microscopic observation of the ensuing cell outgrowth events at the single cell level. Our proof-of-concept studies revealed that fibrillar Fn, compared to Fn-coated surfaces, provides far stronger sprouting and guidance cues to endothelial cells, independent of the tested mechanical strains of the Fn fibers. Additionally, we found that VEGF-A, but not VEGF-C, stimulates the collective outgrowth of lymphatic endothelial cells (LEC), while the collective outgrowth of blood vascular endothelial cells (HUVEC) was prominent even in the absence of these angiogenic factors. In addition to the findings presented here, the modularity of our assay allows for the use of different ECM or synthetic fibers as substrates, as well as of other cell types, thus expanding the range of applications in vascular biology and beyond.
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Affiliation(s)
- Maria Mitsi
- Laboratory of Applied Mechanobiology, ETH Zurich, Zurich, Switzerland
| | | | | | | | - Michael Detmar
- Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, ETH Zurich, Zurich, Switzerland
- * E-mail:
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Budak H, Kantar M. Harnessing NGS and Big Data Optimally: Comparison of miRNA Prediction from Assembled versus Non-assembled Sequencing Data--The Case of the Grass Aegilops tauschii Complex Genome. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2015; 19:407-15. [PMID: 26061358 DOI: 10.1089/omi.2015.0038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
MicroRNAs (miRNAs) are small, endogenous, non-coding RNA molecules that regulate gene expression at the post-transcriptional level. As high-throughput next generation sequencing (NGS) and Big Data rapidly accumulate for various species, efforts for in silico identification of miRNAs intensify. Surprisingly, the effect of the input genomics sequence on the robustness of miRNA prediction was not evaluated in detail to date. In the present study, we performed a homology-based miRNA and isomiRNA prediction of the 5D chromosome of bread wheat progenitor, Aegilops tauschii, using two distinct sequence data sets as input: (1) raw sequence reads obtained from 454-GS FLX Titanium sequencing platform and (2) an assembly constructed from these reads. We also compared this method with a number of available plant sequence datasets. We report here the identification of 62 and 22 miRNAs from raw reads and the assembly, respectively, of which 16 were predicted with high confidence from both datasets. While raw reads promoted sensitivity with the high number of miRNAs predicted, 55% (12 out of 22) of the assembly-based predictions were supported by previous observations, bringing specificity forward compared to the read-based predictions, of which only 37% were supported. Importantly, raw reads could identify several repeat-related miRNAs that could not be detected with the assembly. However, raw reads could not capture 6 miRNAs, for which the stem-loops could only be covered by the relatively longer sequences from the assembly. In summary, the comparison of miRNA datasets obtained by these two strategies revealed that utilization of raw reads, as well as assemblies for in silico prediction, have distinct advantages and disadvantages. Consideration of these important nuances can benefit future miRNA identification efforts in the current age of NGS and Big Data driven life sciences innovation.
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Affiliation(s)
- Hikmet Budak
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University , Istanbul, Turkey
| | - Melda Kantar
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University , Istanbul, Turkey
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Mondrinos MJ, Jones PL, Finck CM, Lelkes PI. Engineering de novo assembly of fetal pulmonary organoids. Tissue Eng Part A 2014; 20:2892-907. [PMID: 24825442 DOI: 10.1089/ten.tea.2014.0085] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Induction of morphogenesis by competent lung progenitor cells in a 3D environment is a central goal of pulmonary tissue engineering, yet little is known about the microenvironmental signals required to induce de novo assembly of alveolar-like tissue in vitro. In extending our previous reports of alveolar-like tissue formation by fetal pulmonary cells stimulated by exogenous fibroblast growth factors (FGFs), we identified some of the key endogenous mediators of FGF-driven morphogenesis (organoid assembly), for example, epithelial sacculation, endothelial network assembly, and epithelial-endothelial interfacing. Sequestration of endogenously secreted vascular endothelial growth factor-A (VEGF-A) potently inhibited endothelial network formation, with little or no effect on epithelial morphogenesis. Inhibition of endogenous sonic hedgehog (SHH) partially attenuated FGF-driven endothelial network formation, while the addition of exogenous SHH in the absence of FGFs was able to induce epithelial and endothelial morphogenesis, although with distinct morphological characteristics. Notably, SHH-induced endothelial networks exhibited fewer branch points, reduced sprouting behavior, and a periendothelial extracellular matrix (ECM) virtually devoid of tenascin-C (TN-C). By contrast, focal deposition of endogenous TN-C was observed in the ECM-surrounding endothelial networks of FGF-induced organoids, especially around sprouting tips. In the FGF-induced organoids, TN-C was also observed in the clefts of sacculated epithelium and at the epithelial-endothelial interface. In support of a critical role in the formation of alveolar-like tissue in vitro, TN-C blocking inhibited endothelial network formation and epithelial sacculation. Upon engraftment of in-vitro-generated pulmonary organoids beneath the renal capsule of syngeneic mice, robust neovascularization occurred in 5 days with a large contribution of patent vessels from engrafted organoids, providing proof of principle for exploring intrapulmonary engraftment of prevascularized hydrogel constructs. Expression of proSpC, VEGF-A, and TN-C following 1 week in vivo mirrored the patterns observed in vitro. Taken together, these findings advance our understanding of endogenous growth factor and ECM signals important for de novo formation of pulmonary tissue structures in vitro and demonstrate the potential of an organoid-based approach to lung tissue augmentation.
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Affiliation(s)
- Mark J Mondrinos
- 1 Department of Bioengineering, Temple University , Philadelphia, Pennsylvania
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Baluk P, Adams A, Phillips K, Feng J, Hong YK, Brown MB, McDonald DM. Preferential lymphatic growth in bronchus-associated lymphoid tissue in sustained lung inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1577-92. [PMID: 24631179 DOI: 10.1016/j.ajpath.2014.01.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 12/09/2013] [Accepted: 01/07/2014] [Indexed: 01/19/2023]
Abstract
Lymphatics proliferate, become enlarged, or regress in multiple inflammatory lung diseases in humans. Lymphatic growth and remodeling is known to occur in the mouse trachea in sustained inflammation, but whether intrapulmonary lymphatics exhibit similar plasticity is unknown. We examined the time course, distribution, and dependence on vascular endothelial growth factor receptor (VEGFR)-2/VEGFR-3 signaling of lung lymphatics in sustained inflammation. Lymphatics in mouse lungs were examined under baseline conditions and 3 to 28 days after Mycoplasma pulmonis infection, using prospero heomeobox 1-enhanced green fluorescence protein and VEGFR-3 as markers. Sprouting lymphangiogenesis was evident at 7 days. Lymphatic growth was restricted to regions of bronchus-associated lymphoid tissue (BALT), where VEGF-C-producing cells were scattered in T-cell zones. Expansion of lung lymphatics after infection was reduced 68% by blocking VEGFR-2, 83% by blocking VEGFR-3, and 99% by blocking both receptors. Inhibition of VEGFR-2/VEGFR-3 did not prevent the formation of BALT. Treatment of established infection with oxytetracycline caused BALT, but not the lymphatics, to regress. We conclude that robust lymphangiogenesis occurs in mouse lungs after M. pulmonis infection through a mechanism involving signaling of both VEGFR-2 and VEGFR-3. Expansion of the lymphatic network is restricted to regions of BALT, but lymphatics do not regress when BALT regresses after antibiotic treatment. The lung lymphatic network can thus expand in sustained inflammation, but the expansion is not as reversible as the accompanying inflammation.
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Affiliation(s)
- Peter Baluk
- Department of Anatomy, the Cardiovascular Research Institute, and the Comprehensive Cancer Center, University of California, San Francisco, California.
| | - Alicia Adams
- Department of Anatomy, the Cardiovascular Research Institute, and the Comprehensive Cancer Center, University of California, San Francisco, California
| | - Keeley Phillips
- Department of Anatomy, the Cardiovascular Research Institute, and the Comprehensive Cancer Center, University of California, San Francisco, California
| | - Jennifer Feng
- Department of Anatomy, the Cardiovascular Research Institute, and the Comprehensive Cancer Center, University of California, San Francisco, California
| | - Young-Kwon Hong
- Departments of Surgery, Biochemistry, and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Mary B Brown
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Donald M McDonald
- Department of Anatomy, the Cardiovascular Research Institute, and the Comprehensive Cancer Center, University of California, San Francisco, California
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Altered pulmonary lymphatic development in infants with chronic lung disease. BIOMED RESEARCH INTERNATIONAL 2014; 2014:109891. [PMID: 24527433 PMCID: PMC3909975 DOI: 10.1155/2014/109891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/17/2013] [Indexed: 11/18/2022]
Abstract
Pulmonary lymphatic development in chronic lung disease (CLD) has not been investigated, and anatomy of lymphatics in human infant lungs is not well defined. Hypothesis. Pulmonary lymphatic hypoplasia is present in CLD. Method. Autopsy lung tissues of eighteen subjects gestational ages 22 to 40 weeks with and without history of respiratory morbidity were stained with monoclonal antipodoplanin and reviewed under light microscopy. Percentage of parenchyma podoplanin stained at the acinar level was determined using computerized image analysis; 9 CLD and 4 control subjects gestational ages 27 to 36 weeks were suitable for the analysis. Results. Distinct, lymphatic-specific staining with respect to other vascular structures was appreciated in all gestations. Infants with and without respiratory morbidity had comparable lymphatic distribution which extended to the alveolar ductal level. Podoplanin staining per parenchyma was increased and statistically significant in the CLD group versus controls at the alveolar ductal level (0.06% ± 0.02% versus 0.04% ± 0.01%, 95% CI −0.04% to −0.002%, P < 0.03). Conclusion. Contrary to our hypothesis, the findings show that there is an increase in alveolar lymphatics in CLD. It is suggested that the findings, by expanding current knowledge of CLD pathology, may offer insight into the development of more effective therapies to tackle CLD.
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Ran S, Montgomery KE. Macrophage-mediated lymphangiogenesis: the emerging role of macrophages as lymphatic endothelial progenitors. Cancers (Basel) 2012; 4:618-57. [PMID: 22946011 PMCID: PMC3430523 DOI: 10.3390/cancers4030618] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is widely accepted that macrophages and other inflammatory cells support tumor progression and metastasis. During early stages of neoplastic development, tumor-infiltrating macrophages (TAMs) mount an immune response against transformed cells. Frequently, however, cancer cells escape the immune surveillance, an event that is accompanied by macrophage transition from an anti-tumor to a pro-tumorigenic type. The latter is characterized by high expression of factors that activate endothelial cells, suppress immune response, degrade extracellular matrix, and promote tumor growth. Cumulatively, these products of TAMs promote tumor expansion and growth of both blood and lymphatic vessels that facilitate metastatic spread. Breast cancers and other epithelial malignancies induce the formation of new lymphatic vessels (i.e., lymphangiogenesis) that leads to lymphatic and subsequently, to distant metastasis. Both experimental and clinical studies have shown that TAMs significantly promote tumor lymphangiogenesis through paracrine and cell autonomous modes. The paracrine effect consists of the expression of a variety of pro-lymphangiogenic factors that activate the preexisting lymphatic vessels. The evidence for cell-autonomous contribution is based on the observed tumor mobilization of macrophage-derived lymphatic endothelial cell progenitors (M-LECP) that integrate into lymphatic vessels prior to sprouting. This review will summarize the current knowledge of macrophage-dependent growth of new lymphatic vessels with specific emphasis on an emerging role of macrophages as lymphatic endothelial cell progenitors (M-LECP).
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Affiliation(s)
- Sophia Ran
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-217-545-7026; Fax: +1-217-545-7333
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Bridges JP, Lin S, Ikegami M, Shannon JM. Conditional hypoxia inducible factor-1α induction in embryonic pulmonary epithelium impairs maturation and augments lymphangiogenesis. Dev Biol 2011; 362:24-41. [PMID: 22094019 DOI: 10.1016/j.ydbio.2011.10.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/29/2011] [Accepted: 10/31/2011] [Indexed: 10/15/2022]
Abstract
Hypoxia inducible factor (HIF) 1a, EPAS1 and NEPAS are expressed in the embryonic mouse lung and each isoform exhibits distinct spatiotemporal expression patterns throughout morphogenesis. To further assess the role of the HIF1a isoform in lung epithelial cell differentiation and homeostasis, we created transgenic mice that express a constitutively active isoform of human HIF-1a (HIF-1a three point mutant (TPM)), in a doxycycline-dependent manner. Expression of HIF1a TPM in the developing pulmonary epithelium resulted in lung hypoplasia characterized by defective branching morphogenesis, altered cellular energetics and impaired epithelial maturation, culminating in neonatal lethality at birth from severe respiratory distress. Histological and biochemical analyses revealed expanded glycogen pools in the pulmonary epithelial cells at E18.5, concomitant with decreased pulmonary surfactant, suggesting a delay or an arrest in maturation. Importantly, these defects occurred in the absence of apoptosis or necrosis. In addition, sub-pleural hemorrhaging was evident as early as E14.5 in HIF1a TPM lungs, despite normal patterning of the blood vasculature, consistent with defects in endothelial barrier function. Epithelial expression of HIF1a TPM also resulted in increased VEGFA and VEGFC production, an increase in the number of lymphatic vessels and indirect activation of the multiple Notch pathway components in endothelial precursor cells. Collectively, these data indicate that HIF-1a protein levels in the pulmonary epithelium must be tightly controlled for proper development of the epithelial and mesenchymal compartments.
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Affiliation(s)
- James P Bridges
- Perinatal Institute, Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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Ivan FX, Rajapakse JC, Welsch RE, Rozen SG, Narasaraju T, Xiong GM, Engelward BP, Chow VT. Differential pulmonary transcriptomic profiles in murine lungs infected with low and highly virulent influenza H3N2 viruses reveal dysregulation of TREM1 signaling, cytokines, and chemokines. Funct Integr Genomics 2011; 12:105-17. [PMID: 21874528 DOI: 10.1007/s10142-011-0247-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 07/22/2011] [Accepted: 08/15/2011] [Indexed: 11/25/2022]
Abstract
Investigating the relationships between critical influenza viral mutations contributing to increased virulence and host expression factors will shed light on the process of severe pathogenesis from the systems biology perspective. We previously generated a mouse-adapted, highly virulent influenza (HVI) virus through serial lung-to-lung passaging of a human influenza H3N2 virus strain that causes low virulent influenza (LVI) in murine lungs. This HVI virus is characterized by enhanced replication kinetics, severe lung injury, and systemic spread to major organs. Our gene microarray investigations compared the host transcriptomic responses of murine lungs to LVI virus and its HVI descendant at 12, 48, and 96 h following infection. More intense expression of genes associated with cytokine activity, type 1 interferon response, and apoptosis was evident in HVI at all time-points. We highlighted dysregulation of the TREM1 signaling pathway (an amplifier of cytokine production) that is likely to be upregulated in infiltrating neutrophils in HVI-infected lungs. The cytokine gene expression changes were corroborated by elevated levels of multiple cytokine and chemokine proteins in the bronchoalveolar lavage fluid of infected mice, especially at 12 h post-infection. Concomitantly, the downregulation of genes that mediate proliferative, developmental, and metabolic processes likely contributed to the lethality of HVI as well as lack of lung repair. Overall, our comparative transcriptomic study provided insights into key host factors that influence the dynamics, pathogenesis, and outcome of severe influenza.
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Affiliation(s)
- Fransiskus X Ivan
- Computational and Systems Biology Program, Singapore-MIT Alliance, Singapore, Singapore
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Kulkarni RM, Herman A, Ikegami M, Greenberg JM, Akeson AL. Lymphatic ontogeny and effect of hypoplasia in developing lung. Mech Dev 2010; 128:29-40. [PMID: 20932899 DOI: 10.1016/j.mod.2010.09.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 09/03/2010] [Accepted: 09/28/2010] [Indexed: 11/24/2022]
Abstract
The pulmonary lymphatic vasculature plays a vital role in maintaining fluid homeostasis required for efficient gas exchange at capillary alveolar barriers and contributes to lung fluid clearance at birth. To further understanding of pulmonary lymphatic function at birth, lineage-tracing analysis of mouse lung was used. Lineage analysis confirmed that lymphatic endothelial cells (LEC) bud from extrapulmonary lymphatics and demonstrated that LEC migrate into developing lung along precise pathways. LEC cluster first in the primary bronchovascular region then along the secondary broncho-arterial regions and along veins. Small lymphatic vessels in distal lung develop from LEC that have migrated into lung mesenchyme from the extrapulmonary lymphatics. Finally, proximal and distal lymphatics remodel to form vessels with lumens in stereotypical locations. Loss of function analysis with lung-specific expression of a secreted form of the extracellular domain of vascular endothelial growth factor receptor-3 (dnR3) caused significant embryonic pulmonary lymphatic hypoplasia with fourfold reduction in distal LEC. Lung-specific expression of dnR3 did not affect blood vascular development, overall lung organogenesis or lymphatic development in other organs. Neonatal mice with pulmonary lymphatic hypoplasia developed respiratory distress with significantly increased mortality. During the transition to air breathing, lymphatic hypoplasia adversely affected fetal lung fluid clearance as determined by wet/dry weight analysis and morphometric analysis of bronchovascular cuffing and mesenchymal thickening. Surfactant synthesis was unaffected. Together, these data demonstrate that lung lymphatics develop autonomously and that pulmonary lymphatic hypoplasia is detrimental to survival of the neonate due to impaired lung fluid clearance.
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Affiliation(s)
- Rishikesh M Kulkarni
- Division of Pulmonary Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
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Ciau-Uitz A, Pinheiro P, Gupta R, Enver T, Patient R. Tel1/ETV6 specifies blood stem cells through the agency of VEGF signaling. Dev Cell 2010; 18:569-78. [PMID: 20412772 DOI: 10.1016/j.devcel.2010.02.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/07/2010] [Accepted: 02/05/2010] [Indexed: 01/17/2023]
Abstract
The regulation of stem cell ontogeny is poorly understood. We show that the leukemia-associated Ets transcription factor, Tel1/ETV6, specifies the first hematopoietic stem cells (HSCs) in the dorsal aorta (DA). In contrast, Tel1/ETV6 has little effect on embryonic blood formation, further distinguishing the programming of the long- and short-term blood populations. Consistent with the notion of concordance of arterial and HSC programs, we show that Tel1/ETV6 is also required for the specification of the DA as an artery. We further show that Tel1/ETV6 acts by regulating the transcription of VegfA in both the lateral plate mesoderm and also in the somites. Exogenous VEGFA rescues Tel1/ETV6 morphants, and depletion of VEGFA or its receptor, Flk1, largely phenocopies Tel1/ETV6 depletion. Few such links between intrinsic and extrinsic programming of stem cells have been reported previously. Our data place Tel1/ETV6 at the apex of the genetic regulatory cascade leading to HSC production.
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Affiliation(s)
- Aldo Ciau-Uitz
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
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Akeson A, Herman A, Wiginton D, Greenberg J. Endothelial cell activation in a VEGF-A gradient: relevance to cell fate decisions. Microvasc Res 2010; 80:65-74. [PMID: 20144626 DOI: 10.1016/j.mvr.2010.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 01/28/2010] [Accepted: 02/01/2010] [Indexed: 12/12/2022]
Abstract
Distribution of vascular endothelial cell growth factor A (VEGF-A) as a gradient determines microvascular endothelial cell (EC) fate during organogenesis. While much is understood about mechanisms of differential distribution, less is known about how EC perceive and interpret a graded VEGF-A signal to generate positional target gene activation. Using microvascular EC, we analyzed the effect of time and graded VEGF-A input on VEGFR2 autophosphorylation, signal kinase activation and induction of immediate-early genes. The threshold and time to peak activation of VEGFR2 were dependent on signal strength over a 50-fold range in concentration with 3-fold concentration differences readily distinguished. Longer duration of exposure did not compensate for low concentration of VEGF-A, suggesting intensity and duration of signal were not interpreted equivalently. With the same conditions, graded and time-sensitive information was transduced through the PLCgamma/p44/p42MAPK signal pathway but not the parallel AKT pathway. Analysis of MAPK-induced angiogenic immediate-early genes determined that EGR-1, EGR-3, and NR4A1 were dependent on graded input while NR4A2 and DSCR1 were independent with 'switch-like' induction. These data demonstrate rapid, linear integration of VEGF-A levels but independent interpretation of duration of signal and identify potential nodes for segregation of gradient-dependent and -independent responses. These results describe how microvascular EC fate decisions can be determined by comparatively moderate changes in VEGF signal strength, resulting in combinatorial changes in the repertoire of immediate-early genes for transcription effectors.
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Affiliation(s)
- Ann Akeson
- Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Research Foundation, Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229, USA.
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Kulkarni RM, Greenberg JM, Akeson AL. NFATc1 regulates lymphatic endothelial development. Mech Dev 2009; 126:350-65. [PMID: 19233265 DOI: 10.1016/j.mod.2009.02.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 02/09/2009] [Accepted: 02/11/2009] [Indexed: 01/23/2023]
Abstract
NFATc1 transcription factor is critical for lineage selection in T-cell differentiation, cardiac valve morphogenesis and osteoclastogenesis. We identified a role for calcineurin-NFAT signaling in lymphatic development and patterning. NFATc1 was colocalized with lymphatic markers Prox-1, VEGFR-3 and podoplanin on cardinal vein as lymphatic endothelial cells (LEC) are specified and as they segregate into lymph sacs and mature lymphatics. In NFATc1 null mice, Prox-1, VEGFR-3 and podoplanin positive endothelial cells sprouted from the cardinal vein at E11.5, but poorly coalesced into lymph sacs. NFAT activation requires the phosphatase calcineurin. Embryos treated in utero with the calcineurin inhibitor cyclosporine-A showed cytoplasmic NFATc1, diminished podoplanin and FGFR-3 expression by the lymphatics and irregular patterning of the LEC sprouts coming off the jugular lymph sac, which suggests a role for calcineurin-NFAT signaling in lymphatic patterning. In a murine model of injury-induced lymphangiogenesis, NFATc1 was expressed on the neolymphatics induced by lung-specific overexpression of VEGF-A. Mice lacking the calcineurin Abeta regulatory subunit, with diminished nuclear NFAT, failed to respond to VEGF-A with increased lymphangiogenesis. In vitro, endogenous and VEGF-A-induced VEGFR-3 and podoplanin expression by human microvascular endothelial cells was reduced by siRNA to NFATc1, to levels comparable to reductions seen with siRNA to Prox-1. In reporter assays, NFATc1 activated lymphatic specific gene promoters. These results demonstrate the role of calcineurin-NFAT pathway in lymphangiogenesis and suggest that NFATc1 is the principle NFAT involved.
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Affiliation(s)
- Rishikesh M Kulkarni
- Division of Pulmonary Biology, MLC7009, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
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Abstract
The lymphatic circulation appears to be a vital component in lung biology in health and in disease. Animal models have established the role of the lymphatic circulation in neoplastic and inflammatory diseases of the lung, such as asthma and cancer, and allowed for the understanding of the molecular controls of lymphangiogenesis in normal lung development. Understanding the role of lymphatics in human lung disease appears likely to contribute to the understanding of the pathogenesis of disease and the development of novel therapeutic targets.
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Affiliation(s)
- Souheil El-Chemaly
- Translational Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bldg. 10, Rm 6D03, MSC 1590, Bethesda, MD 20892-1590, USA
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Recipient-derived neoangiogenesis of arterioles and lymphatics in quilty lesions of cardiac allografts. Transplantation 2007; 84:1335-42. [PMID: 18049119 DOI: 10.1097/01.tp.0000287458.72440.75] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The contribution of extracardiac cells to tissue turnover in heart allografts has recently been demonstrated. Complex subendocardial infiltrates, known as Quilty lesions, are frequently observed in cardiac allografts. The origin of the different cellular components of Quilty lesions is not known. METHODS Different constituents of these lymphonodular infiltrates were analyzed with regard to donor or recipient derivation. Laser-assisted microdissection with subsequent short tandem repeat polymerase chain reaction (PCR)-based "genetic fingerprinting" was employed. Combined immunofluorescence and fluorescence in situ hybridization for sex chromosomes was performed for confirmation in cases of gender-mismatched transplantation. Expression of angiogenic factors (FGF-2, PDGF-alpha, PDGF-alpha-receptor, and VEGF-alpha) was analyzed by quantitative real-time reverse-transcription PCR and immunohistochemistry. RESULTS The inflammatory, nonvascular component of Quilty lesions was completely recipient-derived. Blood vessels were of mixed origin. Different compartments of blood vessels displayed different rates of recipient derivation (endothelium up to 50%, smooth muscle cells up to 15%). Lymphatic vessels were mainly recipient-derived. Of the angiogenic molecules, VEGF-alpha expression was significantly increased in the adjacent myocardium, compared to controls and the Quilty lesions themselves. CONCLUSIONS The inflammatory compartment of Quilty lesions is of recipient origin and shows chimeric neoangiogenesis of blood and lymphatic vessels. VEGF-alpha produced in the adjacent myocardium appears to stimulate the chimeric neoangiogenesis.
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