256. Ovarian lymphatic vascular development is hormonally regulated and Adamts1-dependent

2008 ◽  
Vol 20 (9) ◽  
pp. 56
Author(s):  
H. M. Brown ◽  
R. L. Robker ◽  
D. L. Russell

The lymphatic system is important for return of extra-vascular fluid to the blood circulation, conductance of hormones and immune cell trafficking. Delicate hormonal control of fluid conductance during reproductive cycles is exemplified by the ovarian hyperstimulation syndrome, a dangerous condition of hypovolemia caused by fluid accumulation in the abdomen and reproductive tissues, in response to hormonal hyperstimulation. This study is the first to investigate the relationship between ovarian lymphatic development and follicle growth. Quantitative morphometric analysis of vessel size and number in mouse ovary revealed, for the first time, that the ovarian lymphatic vasculature develops postnatally and in synchrony with the induction of ovarian CYP19a1 (Aromatase); the time when secondary follicles become FSH-responsive and estrogenic. Mechanistically, we found that the FSH-analogue eCG mediates induction of lymphatic vascular endothelial growth factor Vegfd and the receptor Vegfr3 (Flt4) in granulosa cells. Importantly, stimulation with eCG also enhanced ovarian lymphatic vessel number and size. However, formation of ovarian lymphatics also required the matrix-remodelling protease Adamts1, since ovaries from Adamts1−/− mice failed to undergo normal lymphatic vascular development. Treatment of Adamts1 null mice with eCG significantly increased the number and size of ovarian lymphatic vessels, however, the vessels were still smaller and fewer in number than wildtypes. These combined results indicate that the ovarian lymphatic system develops in response to hormonal signals, which promote folliculogenesis, through induction of lymphangiogenic factors in granulosa cells; as well as involving Adamts1-dependent mechanisms. This study is the first demonstration of the novel principle of hormonal regulation of lymphangiogenesis in any tissue and suggests a requirement for functional lymphatics during normal folliculogenesis. In addition our results inform the elucidation of the tightly regulated processes that control fluid dynamics and immune cell surveillance within reproductive tissues.

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0249256
Author(s):  
Esther Redder ◽  
Nils Kirschnick ◽  
Stefanie Bobe ◽  
René Hägerling ◽  
Nils Rouven Hansmeier ◽  
...  

Lymphatic vessels are indispensable for tissue fluid homeostasis, transport of solutes and dietary lipids and immune cell trafficking. In contrast to blood vessels, which are easily visible by their erythrocyte cargo, lymphatic vessels are not readily detected in the tissue context. Their invisibility interferes with the analysis of the three-dimensional lymph vessel structure in large tissue volumes and hampers dynamic intravital studies on lymphatic function and pathofunction. An approach to overcome these limitations are mouse models, which express transgenic fluorescent proteins under the control of tissue-specific promotor elements. We introduce here the BAC-transgenic mouse reporter strain Vegfr3-tdTomato that expresses a membrane-tagged version of tdTomato under control of Flt4 regulatory elements. Vegfr3-tdTomato mice inherited the reporter in a mendelian fashion and showed selective and stable fluorescence in the lymphatic vessels of multiple organs tested, including lung, kidney, heart, diaphragm, intestine, mesentery, liver and dermis. In this model, tdTomato expression was sufficient for direct visualisation of lymphatic vessels by epifluorescence microscopy. Furthermore, lymph vessels were readily visualized using a number of microscopic modalities including confocal laser scanning, light sheet fluorescence and two-photon microscopy. Due to the early onset of VEGFR-3 expression in venous embryonic vessels and the short maturation time of tdTomato, this reporter offers an interesting alternative to Prox1-promoter driven lymphatic reporter mice for instance to study the developmental differentiation of venous to lymphatic endothelial cells.


Author(s):  
Michael Weiler ◽  
J. Brandon Dixon

The lymphatic vasculature is present in nearly every tissue of the body to serve essential functions in fluid homeostasis, immune cell trafficking, and lipid transport, and it has been implicated in the progression of several diseases. Despite the critical roles that this system performs, very little is known about the lymphatic vasculature in comparison to the blood vasculature, which can be attributed, in part, to the difficulty associated with imaging lymphatic vessels. With the growing interest in studying lymphatics, near-infrared (NIR) imaging has emerged in the literature as a novel lymphatic imaging modality to simultaneously improve spatial resolution to visualize small initial lymphatics and increase temporal resolution to capture the dynamic lymphatic pump function responsible for fluid propulsion.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1344
Author(s):  
Kim Pin Yeo ◽  
Hwee Ying Lim ◽  
Veronique Angeli

In recent years, lymphatic vessels have received increasing attention and our understanding of their development and functional roles in health and diseases has greatly improved. It has become clear that lymphatic vessels are critically involved in acute and chronic inflammation and its resolution by supporting the transport of immune cells, fluid, and macromolecules. As we will discuss in this review, the involvement of lymphatic vessels has been uncovered in atherosclerosis, a chronic inflammatory disease of medium- and large-sized arteries causing deadly cardiovascular complications worldwide. The progression of atherosclerosis is associated with morphological and functional alterations in lymphatic vessels draining the diseased artery. These defects in the lymphatic vasculature impact the inflammatory response in atherosclerosis by affecting immune cell trafficking, lymphoid neogenesis, and clearance of macromolecules in the arterial wall. Based on these new findings, we propose that targeting lymphatic function could be considered in conjunction with existing drugs as a treatment option for atherosclerosis.


2021 ◽  
Vol 8 ◽  
Author(s):  
Takuro Miyazaki ◽  
Akira Miyazaki

Lymphatic vessels are necessary for maintaining tissue fluid balance, trafficking of immune cells, and transport of dietary lipids. Growing evidence suggest that lymphatic functions are limited under hypercholesterolemic conditions, which is closely related to atherosclerotic development involving the coronary and other large arteries. Indeed, ablation of lymphatic systems by Chy-mutation as well as depletion of lymphangiogenic factors, including vascular endothelial growth factor-C and -D, in mice perturbs lipoprotein composition to augment hypercholesterolemia. Several investigations have reported that periarterial microlymphatics were attracted by atheroma-derived lymphangiogenic factors, which facilitated lymphatic invasion into the intima of atherosclerotic lesions, thereby modifying immune cell trafficking. In contrast to the lipomodulatory and immunomodulatory roles of the lymphatic systems, the critical drivers of lymphangiogenesis and the details of lymphatic insults under hypercholesterolemic conditions have not been fully elucidated. Interestingly, cholesterol-lowering trials enable hypercholesterolemic prevention of lymphatic drainage in mice; however, a causal relationship between hypercholesterolemia and lymphatic defects remains elusive. In this review, the contribution of aberrant lymphangiogenesis and lymphatic cholesterol transport to hypercholesterolemic atherosclerosis was highlighted. The causal relationship between hypercholesterolemia and lymphatic insults as well as the current achievements in the field were discussed.


2019 ◽  
Author(s):  
Daniel Peña-Jimenez ◽  
Silvia Fontenete ◽  
Diego Megias ◽  
Coral Fustero-Torre ◽  
Osvaldo Graña-Castro ◽  
...  

AbstractLymphatic vessels (LV) are essential for skin fluid homeostasis and immune cell trafficking, but whether LV are associated with hair follicle (HF) regeneration is not known. Here, by using steady and live imaging approaches in mouse skin, we show that lymphatic capillaries distribute to the anterior permanent region of individual HF and interconnect neighboring HF at the level of the HF bulge, in a hair follicle stem cell (HFSC)-dependent manner. LV further connect individual HF in triads and dynamically flow across the skin. Interestingly, at the onset of the physiological HFSC activation, or upon pharmacological or genetic induction of HF growth, LV transiently expand their caliber suggesting an increased tissue drainage capacity. Interestingly, the physiological LV caliber increase is associated with a distinct gene expression correlated to ECM and cytoskeletal reorganization. Using mouse genetics, we show that the depletion of LV blocks the pharmacological induction of HF growth. Our findings define LV as components of the HFSC niche, coordinating HF connections at tissue-level, and provide insight into their functional contribution to HF regeneration.


Author(s):  
J. Brandon Dixon

The lymphatic vasculature extends through most tissues of the body and plays an essential role in maintaining fluid balance, immune cell trafficking, and lipid transport. Nearly all dietary lipid is transported from the intestine to the circulation via the lymphatic system in the form of triglyceride-rich lipoproteins called chylomicrons. This process can be described through two different mechanisms: 1) entry of the chylomicron into the initial lymphatic vessels of the small intestine, known as lacteals, and 2) the transport of these chylomicrons through the larger collecting lymphatics by a complex and coordinated system of individual contracting vessel units (lymphangions) and valve leaflets. We describe here a set of in vitro and in vivo tools we have developed to study the mechanisms that modulate lipid transport under these two different paradigms and show how these tools are uncovering important biological features involved in these mechanisms. Lymphatic pump function is known to be sensitive to the mechanical load on the vessel as the contractility of isolated vessels has been shown to be both shear and stretch sensitive [1], yet whether these mechanisms are important in regulating contractile function in vivo remains uncertain.


2021 ◽  
Vol 22 (11) ◽  
pp. 5734
Author(s):  
Avigail Ehrlich ◽  
Filippo Molica ◽  
Aurélie Hautefort ◽  
Brenda R. Kwak

This review highlights current knowledge on the expression and function of connexins and pannexins, transmembrane channel proteins that play an important role in intercellular communication, in both the developing and mature lymphatic vasculature. A particular focus is given to the involvement of these proteins in functions of the healthy lymphatic system. We describe their influence on the maintenance of extracellular fluid homeostasis, immune cell trafficking to draining lymph nodes and dietary nutrient absorption by intestinal villi. Moreover, new insights into connexin mutations in primary and secondary lymphedema as well as on the implication of lymphatic connexins and pannexins in acquired cardiovascular diseases are discussed, allowing for a better understanding of the role of these proteins in pathologies linked to dysfunctions in the lymphatic system.


2006 ◽  
Vol 190 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Malha Sahmi ◽  
Edmir S Nicola ◽  
Christopher A Price

In the present study, we determined the potential for post-transcriptional regulation of cytochrome P450 aromatase (Cyp19), cytochrome P450 side-chain cleavage (Cyp11a) and 17β-hydroxysteroid dehydrogenase I (Hsd17b1) mRNA. Bovine granulosa cells were cultured in non-luteinizing conditions that permit long-term oestradiol secretion. Half-lives of mRNA were measured by Northern and/or reverse transcriptase (RT)-PCR after inhibition of gene transcription. In FSH-stimulated cells, the Cyp11a and Hsd17b1 mRNAs had half-lives greater than 12 h. The half-life of Cyp19 mRNA was significantly shorter at 3 h. The addition of the translation inhibitor cycloheximide to FSH-stimulated cells significantly increased Cyp19 mRNA half-life to approximately 12 h. Stimulation of cells with insulin resulted in Cyp19 mRNA half-life that was double (P<0.05) that in FSH-stimulated cells. We conclude that bovine Cyp19 mRNA is very labile under physiological conditions, and that Cyp19 expression is under hormonal control at a post-transcriptional level.


Reproduction ◽  
2006 ◽  
Vol 132 (1) ◽  
pp. 147-158 ◽  
Author(s):  
S O’Leary ◽  
M J Jasper ◽  
S A Robertson ◽  
D T Armstrong

Seminal plasma (SP) acts to influence the uterine endometrium after mating, activating synthesis of embryotrophic cytokines and inflammatory changes that condition the tract for embryo implantation and establishing pregnancy. The objective of this study was to investigate in pigs whether the ovary might also be responsive to SP exposure. Prepubertal gilts were synchronised with exogenous gonadotrophins and received transcervical treatment with pooled boar SP or PBS; then the ovarian tissue was recovered at 34 h (preovulation) and on days 5 and 9 after treatment. The ovarian response was assessed by measuring ovulation rate, number and size of corpora lutea, ovarian leukocyte populations, progesterone productionin vivo, as well as responses of retrieved granulosa cells culturedin vitro. In SP-treated gilts, leukocyte recruitment into the ovarian tissues was increased fourfold at 34 h, with macrophages comprising the most abundant cell lineage. There was no effect of SP on the number of oocytes ovulated; however, the weight of corpora lutea was increased in SP-treated gilts. SP also induced an increase in plasma progesterone content seen from day 5 to at least day 9 after treatment. In addition, granulosa cells and thecal tissue retrieved from preovulatory follicles of SP-treated gilts were more responsivein vitroto growth factor- and gonadotrophin-stimulated cell proliferation and progesterone synthesis. These results suggest that uterine exposure to SP influences immune cell trafficking in the ovary and enhances steroidogenesis in early pregnancy. The effects of SP on ovarian function potentially contribute to reproductive success in the pig.


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