scholarly journals Normal Lymphatic Development and Function in Mice Deficient for the Lymphatic Hyaluronan Receptor LYVE-1

2006 ◽  
Vol 27 (2) ◽  
pp. 595-604 ◽  
Author(s):  
Nicholas W. Gale ◽  
Remko Prevo ◽  
Jorge Espinosa ◽  
David J. Ferguson ◽  
Melissa G. Dominguez ◽  
...  

ABSTRACT The hyaluronan receptor LYVE-1 is expressed abundantly on the surfaces of lymphatic vessels and lymph node sinus endothelial cells from early development, where it has been suggested to function both in cell adhesion/transmigration and as a scavenger for hyaluronan turnover. To investigate the physiological role(s) of LYVE-1, we generated mice in which the gene for the receptor was inactivated by replacement with a β-galactosidase reporter. LYVE-1−/− mice displayed an apparently normal phenotype, with no obvious alteration in lymphatic vessel ultrastructure or function and no apparent change in secondary lymphoid tissue structure or cellularity. In addition, the levels of hyaluronan in tissue and blood were unchanged. LYVE-1−/− mice also displayed normal trafficking of cutaneous CD11c+ dendritic cells to draining lymph nodes via afferent lymphatics and normal resolution of oxazolone-induced skin inflammation. Finally, LYVE-1−/− mice supported normal growth of transplanted B16F10 melanomas and Lewis lung carcinomas. These results indicate that LYVE-1 is not obligatory for normal lymphatic development and function and suggest either the existence of compensatory receptors or a role more specific than that previously envisaged.

Blood ◽  
2010 ◽  
Vol 116 (23) ◽  
pp. 5060-5070 ◽  
Author(s):  
Hayakazu Sumida ◽  
Kyoko Noguchi ◽  
Yasuyuki Kihara ◽  
Manabu Abe ◽  
Keisuke Yanagida ◽  
...  

Abstract Lysophosphatidic acid (LPA) is a potent lipid mediator with a wide variety of biological actions mediated through G protein-coupled receptors (LPA1-6). LPA4 has been identified as a G13 protein-coupled receptor, but its physiological role is unknown. Here we show that a subset of LPA4-deficient embryos did not survive gestation and displayed hemorrhages and/or edema in many organs at multiple embryonic stages. The blood vessels of bleeding LPA4-deficient embryos were often dilated. The recruitment of mural cells, namely smooth muscle cells and pericytes, was impaired. Consistently, Matrigel plug assays showed decreased mural cell coverage of endothelial cells in the neovessels of LPA4-deficient adult mice. In situ hybridization detected Lpa4 mRNA in the endothelium of some vasculatures. Similarly, the lymphatic vessels of edematous embryos were dilated. These results suggest that LPA4 regulates establishment of the structure and function of blood and lymphatic vessels during mouse embryogenesis. Considering the critical role of autotaxin (an enzyme involved in LPA production) and Gα13 in vascular development, we suggest that LPA4 provides a link between these 2 molecules.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyunjin Yoo ◽  
Young Jae Lee ◽  
Chanhyeok Park ◽  
Dabin Son ◽  
Dong Yoon Choi ◽  
...  

AbstractProper functioning of the lymphatic system is required for normal immune responses, fluid balance, and lipid reabsorption. Multiple regulatory mechanisms are employed to ensure the correct formation and function of lymphatic vessels; however, the epigenetic modulators and mechanisms involved in this process are poorly understood. Here, we assess the regulatory role of mouse Dot1l, a histone H3 lysine (K) 79 (H3K79) methyltransferase, in lymphatic formation. Genetic ablation of Dot1l in Tie2(+) endothelial cells (ECs), but not in Lyve1(+) or Prox1(+) lymphatic endothelial cells (LECs) or Vav1(+) definitive hematopoietic stem cells, leads to catastrophic lymphatic anomalies, including skin edema, blood–lymphatic mixing, and underdeveloped lymphatic valves and vessels in multiple organs. Remarkably, targeted Dot1l loss in Tie2(+) ECs leads to fully penetrant lymphatic aplasia, whereas Dot1l overexpression in the same cells results in partially hyperplastic lymphatics in the mesentery. Genetic studies reveal that Dot1l functions in c-Kit(+) hemogenic ECs during mesenteric lymphatic formation. Mechanistically, inactivation of Dot1l causes a reduction of both H3K79me2 levels and the expression of genes important for LEC development and function. Thus, our study establishes that Dot1l-mediated epigenetic priming and transcriptional regulation in LEC progenitors safeguard the proper lymphatic development and functioning of lymphatic vessels.


2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suxing Liu ◽  
Dong Liu ◽  
Ru Shen ◽  
Di Li ◽  
Qiyue Hu ◽  
...  

AbstractClinical success of IL-17/IL-23 pathway biologics for the treatment of moderate to severe psoriasis suggests that targeting RORγt, a master regulator for the proliferation and function of Th17 cells, could be an effective alternative. However, oral RORγ antagonists (VTP43742, TAK828) with high systemic exposure showed toxicity in phase I/II clinical trials and terminated development. To alleviate the potential safety concerns, identifying compounds with skin-restricted exposure amenable for topical use is of great interest. Systematic structure activity relationship study and multi-parameter optimization led to the discovery of a novel RORγ antagonist (SHR168442) with desired properties for a topical drug. It suppressed the transcription of IL-17 gene, leading to reduction of IL-17 cytokine secretion. It showed high exposure in skin, but low in plasma. Topical application of SHR168442 in Vaseline exhibited excellent efficacy in the imiquimod-induced and IL-23-induced psoriasis-like skin inflammation mouse models and correlated with the reduction of Th17 pathway cytokines, IL-6, TNFα and IL-17A. This work demonstrated restricted skin exposure of RORγ antagonist may provide a new topical treatment option as targeted therapeutics for mild to moderate psoriasis patients and may be suitable for the treatment of any other inflammatory disorders that are accessible locally.


Angiogenesis ◽  
2021 ◽  
Author(s):  
Daniyal J. Jafree ◽  
David A. Long ◽  
Peter J. Scambler ◽  
Christiana Ruhrberg

AbstractLymphatic vessels have critical roles in both health and disease and their study is a rapidly evolving area of vascular biology. The consensus on how the first lymphatic vessels arise in the developing embryo has recently shifted. Originally, they were thought to solely derive by sprouting from veins. Since then, several studies have uncovered novel cellular mechanisms and a diversity of contributing cell lineages in the formation of organ lymphatic vasculature. Here, we review the key mechanisms and cell lineages contributing to lymphatic development, discuss the advantages and limitations of experimental techniques used for their study and highlight remaining knowledge gaps that require urgent attention. Emerging technologies should accelerate our understanding of how lymphatic vessels develop normally and how they contribute to disease.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 834
Author(s):  
Anima M. Schäfer ◽  
Henriette E. Meyer zu Schwabedissen ◽  
Markus Grube

The central nervous system (CNS) is an important pharmacological target, but it is very effectively protected by the blood–brain barrier (BBB), thereby impairing the efficacy of many potential active compounds as they are unable to cross this barrier. Among others, membranous efflux transporters like P-Glycoprotein are involved in the integrity of this barrier. In addition to these, however, uptake transporters have also been found to selectively uptake certain compounds into the CNS. These transporters are localized in the BBB as well as in neurons or in the choroid plexus. Among them, from a pharmacological point of view, representatives of the organic anion transporting polypeptides (OATPs) are of particular interest, as they mediate the cellular entry of a variety of different pharmaceutical compounds. Thus, OATPs in the BBB potentially offer the possibility of CNS targeting approaches. For these purposes, a profound understanding of the expression and localization of these transporters is crucial. This review therefore summarizes the current state of knowledge of the expression and localization of OATPs in the CNS, gives an overview of their possible physiological role, and outlines their possible pharmacological relevance using selected examples.


2020 ◽  
Vol 31 (6) ◽  
pp. 1178-1190 ◽  
Author(s):  
Daniyal J. Jafree ◽  
David A. Long

The kidney contains a network of lymphatic vessels that clear fluid, small molecules, and cells from the renal interstitium. Through modulating immune responses and via crosstalk with surrounding renal cells, lymphatic vessels have been implicated in the progression and maintenance of kidney disease. In this Review, we provide an overview of the development, structure, and function of lymphatic vessels in the healthy adult kidney. We then highlight the contributions of lymphatic vessels to multiple forms of renal pathology, emphasizing CKD, transplant rejection, and polycystic kidney disease and discuss strategies to target renal lymphatics using genetic and pharmacologic approaches. Overall, we argue the case for lymphatics playing a fundamental role in renal physiology and pathology and treatments modulating these vessels having therapeutic potential across the spectrum of kidney disease.


Blood ◽  
2011 ◽  
Vol 118 (7) ◽  
pp. 1989-1997 ◽  
Author(s):  
Kyle Niessen ◽  
Gu Zhang ◽  
John Brady Ridgway ◽  
Hao Chen ◽  
Ganesh Kolumam ◽  
...  

Abstract The Notch signaling pathway plays a fundamental role during blood vessel development. Notch signaling regulates blood vessel morphogenesis by promoting arterial endothelial differentiation and pro-viding spatial and temporal control over “tip cell” phenotype during angiogenic sprouting. Components of the Notch signaling pathway have emerged as potential regulators of lymphatic development, joining the increasing examples of blood vessel regulators that are also involved in lymphatic development. However, in mammals a role for the Notch signaling pathway during lymphatic development remains to be demonstrated. In this report, we show that blockade of Notch1 and Dll4, with specific function-blocking antibodies, results in defective postnatal lymphatic development in mice. Mechanistically, Notch1-Dll4 blockade is associated with down-regulation of EphrinB2 expression, been shown to be critically involved in VEGFR3/VEGFC signaling, resulting in reduced lymphangiogenic sprouting. In addition, Notch1-Dll4 blockade leads to compromised expression of distinct lymphatic markers and to dilation of collecting lymphatic vessels with reduced and disorganized mural cell coverage. Finally, Dll4-blockade impairs wound closure and severely affects lymphangiogenesis during the wound healing in adult mouse skin. Thus, our study demonstrates for the first time in a mammalian system that Notch1-Dll4 signaling pathway regulates postnatal lymphatic development and pathologic lymphangiogenesis.


2009 ◽  
Vol 206 (11) ◽  
pp. 2455-2467 ◽  
Author(s):  
Christian A. Kunder ◽  
Ashley L. St. John ◽  
Guojie Li ◽  
Kam W. Leong ◽  
Brent Berwin ◽  
...  

During infection, signals from the periphery are known to reach draining lymph nodes (DLNs), but how these molecules, such as inflammatory cytokines, traverse the significant distances involved without dilution or degradation remains unclear. We show that peripheral mast cells, upon activation, release stable submicrometer heparin-based particles containing tumor necrosis factor and other proteins. These complexes enter lymphatic vessels and rapidly traffic to the DLNs. This physiological drug delivery system facilitates communication between peripheral sites of inflammation and remote secondary lymphoid tissues.


2021 ◽  
Vol 118 (3) ◽  
pp. e2021364118
Author(s):  
Hannah L. Miller ◽  
Prabhakar Sairam Andhey ◽  
Melissa K. Swiecki ◽  
Bruce A. Rosa ◽  
Konstantin Zaitsev ◽  
...  

Plasmacytoid dendritic cells (pDCs) specialize in the production of type I IFN (IFN-I). pDCs can be depleted in vivo by injecting diphtheria toxin (DT) in a mouse in which pDCs express a diphtheria toxin receptor (DTR) transgene driven by the human CLEC4C promoter. This promoter is enriched for binding sites for TCF4, a transcription factor that promotes pDC differentiation and expression of pDC markers, including CLEC4C. Here, we found that injection of DT in CLEC4C-DTR+ mice markedly augmented Th2-dependent skin inflammation in a model of contact hypersensitivity (CHS) induced by the hapten fluorescein isothiocyanate. Unexpectedly, this biased Th2 response was independent of reduced IFN-I accompanying pDC depletion. In fact, DT treatment altered the representation of conventional dendritic cells (cDCs) in the skin-draining lymph nodes during the sensitization phase of CHS; there were fewer Th1-priming CD326+ CD103+ cDC1 and more Th2-priming CD11b+ cDC2. Single-cell RNA-sequencing of CLEC4C-DTR+ cDCs revealed that CD326+ DCs, like pDCs, expressed DTR and were depleted together with pDCs by DT treatment. Since CD326+ DCs did not express Tcf4, DTR expression might be driven by yet-undefined transcription factors activating the CLEC4C promoter. These results demonstrate that altered DC representation in the skin-draining lymph nodes during sensitization to allergens can cause Th2-driven CHS.


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