Lymphatic endothelium: morphological, molecular and functional properties (original) (raw)

Lymphatic Biology and the Microcirculation: Past, Present and Future

Microcirculation, 2005

Because of the role that lymphatics have in fluid and macromolecular exchange, lymphatic function has been tightly tied to the study of the microcirculation for decades. Despite this, our understanding of many basic tenets of lymphatic function is far behind that of the blood vascular system. This is in part due to the difficulty inherent in working in small, thin-walled, clear lymphatic vessels and the relative lack of lymphatic specific molecular/cellular markers. The application of cellular and molecular tools to the field of lymphatic biology has recently produced some significant developments in lymphatic endothelial cell biology. These have propelled our understanding of lymphangiogenesis and related fields forward. Whereas the use of some of these techniques in lymphatic muscle biology has somewhat lagged behind those in the endothelium, recent developments in lymphatic muscle contractile and electrical physiology have also led to advances in our understanding of lymphatic transport function, particularly in the regulation of the intrinsic lymph pump. However, much work remains to be done. This paper reviews significant developments in lymphatic biology and discusses areas where further development of lymphatic biology via classical, cellular, and molecular approaches is needed to significantly advance our understanding of lymphatic physiology. Microcirculation (2005) 12, 141-150.

Digging deeper into lymphatic vessel formation in vitro and in vivo

BMC Cell Biology, 2011

Background Abnormal lymphatic vessel formation (lymphangiogenesis) is associated with different pathologies such as cancer, lymphedema, psoriasis and graft rejection. Lymphatic vasculature displays distinctive features than blood vasculature, and mechanisms underlying the formation of new lymphatic vessels during physiological and pathological processes are still poorly documented. Most studies on lymphatic vessel formation are focused on organism development rather than lymphangiogenic events occurring in adults. We have here studied lymphatic vessel formation in two in vivo models of pathological lymphangiogenesis (corneal assay and lymphangioma). These data have been confronted to those generated in the recently set up in vitro model of lymphatic ring assay. Ultrastructural analyses through Transmission Electron Microscopy (TEM) were performed to investigate tube morphogenesis, an important differentiating process observed during endothelial cell organization into capillary struc...

The lymphatic vasculature revisited

Journal of Clinical Investigation, 2014

Lymphatic vessels constitute a ubiquitous countercurrent system to the blood vasculature that returns interstitial fluid, salts, small molecules, resorbed fat, and cells to the bloodstream. They serve as conduits to lymph nodes and are essential for multiple physiologic activities. However, they are also hijacked by cancer cells to establish initial lymph node metastases, as well as by infectious agents and parasites. Despite these obvious important functions in human pathologies, a more detailed understanding of the molecular mechanisms involved in the regulation of the lymphatic vasculature has trailed that of the blood vasculature for many years, mainly because critical specific characteristics of lymphatic endothelial cells were discovered only recently. In this Review series, several major aspects of the active and passive involvement of the lymphatic vasculature in human disease and physiology are presented, with a focus on translational findings.

Lymphatics at the crossroads of angiogenesis and lymphangiogenesis

Journal of Anatomy, 2004

The lymphatic system is implicated in interstitial fluid balance regulation, immune cell trafficking, oedema and cancer metastasis. However, the sequence of events that initiate and coordinate lymphatic vessel development (lymphangiogenesis) remains obscure. In effect, the understanding of physiological regulation of lymphatic vasculature has been overshadowed by the greater emphasis focused on angiogenesis, and delayed by a lack of specific markers, thereby limiting this field to no more than a descriptive characterization. Recently, new insights into lymphangiogenesis research have been due to the discovery of lymphatic-specific markers and growth factors of vascular endothelial growth factor (VEGF) family, such as VEGF-C and VEGF-D. Studies using transgenic mice overexpressing VEGF-C and VEGF-D have demonstrated a crucial role for these factors in tumour lymphangiogenesis.

Lymphangiogenesis and lymphatic vessel remodelling in cancer

Nature Reviews Cancer, 2014

| The generation of new lymphatic vessels through lymphangiogenesis and the remodelling of existing lymphatics are thought to be important steps in cancer metastasis. The past decade has been exciting in terms of research into the molecular and cellular biology of lymphatic vessels in cancer, and it has been shown that the molecular control of tumour lymphangiogenesis has similarities to that of tumour angiogenesis. Nevertheless, there are significant mechanistic differences between these biological processes. We are now developing a greater understanding of the specific roles of distinct lymphatic vessel subtypes in cancer, and this provides opportunities to improve diagnostic and therapeutic approaches that aim to restrict the progression of cancer. REVIEWS NATURE REVIEWS | CANCER VOLUME 14 | MARCH 2014 | 159

Cell Traffic and the Lymphatic Endothelium

Annals of the New York Academy of Sciences, 2008

The principal immune function of the afferent lymphatics is to bear antigen and leukocytes from peripheral tissues to the draining lymph nodes. Recent research has shown that passage of leukocytes into the afferent lymphatic capillaries is far from an indolent process; rather it is carefully orchestrated by an array of adhesion molecules, as well as by chemokines and their receptors.