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American Journal of Physiology.... Apr 2020Recently, peripheral lymphatic vessels were found to transport high-density lipoprotein (HDL) from interstitial tissues to the blood circulation during reverse...
Recently, peripheral lymphatic vessels were found to transport high-density lipoprotein (HDL) from interstitial tissues to the blood circulation during reverse cholesterol transport. This function is thought to be critical to the clearance of cholesterol from atherosclerotic plaques. The role of organ-specific lymphatics in modulating HDL transport and composition is, however, incompletely understood. This study aimed to ) determine the contribution of the lymphatics draining the intestine and liver (which are major sites of HDL synthesis) to total (thoracic) lymph HDL transport and ) verify whether the HDLs in lymph are derived from specific organs and are modified during trafficking in lymph. The mesenteric, hepatic, or thoracic lymph duct was cannulated in nonfasted Sprague-Dawley rats, and lymph was collected over 5 h under anesthesia. Whole lymph and specific lymph lipoproteins (isolated by ultracentrifugation) were analyzed for protein and lipid composition. The majority of thoracic lymph fluid, protein, and lipid mass was sourced from the mesenteric, and to a lesser extent, hepatic lymph. Mesenteric and thoracic lymph were both rich in chylomicrons and very low-density lipoprotein, whereas hepatic lymph and plasma were HDL-rich. The protein and lipid mass in thoracic lymph HDL was mostly sourced from mesenteric lymph, whereas the cholesterol mass was equally sourced from mesenteric and hepatic lymph. HDLs were compositionally distinct across the lymph sources and plasma. The composition of HDL also appeared to be modified during passage from the mesenteric and hepatic to the thoracic lymph duct. Overall, this study demonstrates that the lipoproteins in lymph are organ specific in composition, and the intestine and liver appear to be the main source of HDL in the lymph. High-density lipoprotein in lymph are organ-specific in composition and derive mostly from the intestine and liver. High-density lipoprotein also appears to be remodeled during transport through the lymphatics. These findings have implications to cardiometabolic diseases that involve perturbations in lipoprotein distribution and metabolism.
Topics: Animals; Biological Transport; Cholesterol, HDL; Female; Lipids; Liver; Lymph; Lymphatic System; Mesentery; Proteins; Rats; Rats, Sprague-Dawley; Thorax
PubMed: 32068443
DOI: 10.1152/ajpgi.00340.2019 -
Scientific Reports Jul 2018Transport of tissue-derived lymphatic fluid and clearance by draining lymph nodes are pivotal for maintenance of fluid homeostasis in the body and for...
Transport of tissue-derived lymphatic fluid and clearance by draining lymph nodes are pivotal for maintenance of fluid homeostasis in the body and for immune-surveillance of the self- and non-self-proteomes. Yet a quantitative analysis of nodal filtration of the tissue-derived proteome present in lymphatic fluid has not been reported. Here we quantified the efficiency of nodal clearance of the composite proteomic load using label-free and isotope-labeling proteomic analysis of pre-nodal and post-nodal samples collected by direct cannulation. These results were extended by quantitation of the filtration efficiency of fluorophore-labeled proteins, bacteria, and beads infused at physiological flow rates into pre-nodal lymphatic collectors and collected by post-nodal cannulation. We developed a linear model of nodal filtration efficiency dependent on pre-nodal protein concentrations and molecular weight, and uncovered criteria for disposing the proteome incoming from defined anatomical districts under physiological conditions. These findings are pivotal to understanding the maximal antigenic load sustainable by a draining node, and promote understanding of pathogen spreading and nodal filtration of tumor metastasis, potentially helping to improve design of vaccination protocols, immunization strategies and drug delivery.
Topics: Animals; Bacteria; Bacteriological Techniques; Lymph; Lymph Nodes; Male; Models, Theoretical; Proteome; Proteomics; Rats, Sprague-Dawley
PubMed: 30050160
DOI: 10.1038/s41598-018-29614-0 -
Shock (Augusta, Ga.) Dec 2014Studies on animal models have documented a role for the water-soluble protein fraction of mesenteric lymph as a conduit from hemorrhagic shock to acute lung injury and...
Studies on animal models have documented a role for the water-soluble protein fraction of mesenteric lymph as a conduit from hemorrhagic shock to acute lung injury and postinjury multiple organ failure. We hypothesize that mesenteric lymph is not an ultrafiltrate of plasma and contains specific protein mediators that may predispose patients to acute lung injury/multiple organ failure. Mesenteric lymph and plasma were collected from critically ill or injured patients and from nine patients with lymphatic injuries, during semielective spine reconstruction, or immediately before organ donation. Proteomic analyses were performed through immunoaffinity depletion of the 14 most abundant plasma proteins and 1D gel electrophoresis followed by liquid chromatography coupled online with mass spectrometry analyses. Overall, 548 proteins were identified in the patients undergoing semielective surgery, of which 155 were uniquely present in the lymph. In addition, the postshock plasma proteome was characterized by peculiar features, suggesting that only a partial overlap exists between the plasma and mesenteric lymph from trauma patients. Differential proteins between the matched plasma and mesenteric lymph from trauma patients could be related to coagulopathy and hypercoagulability, cell lysis, proinflammatory responses and immune system activation, extracellular matrix remodeling, lymph-specific immunomodulation and vascular hypoactivity/neoangiogenesis, and energy/redox metabolic adaptation to trauma. In conclusion, the proteome of mesenteric lymph is biologically different (in qualitative and quantitative terms) than that of a mere plasma ultrafiltrate.
Topics: Adolescent; Adult; Blood Coagulation; Blood Proteins; Chromatography, Liquid; Cluster Analysis; Extracellular Matrix Proteins; Female; Humans; Inflammation; Lymph; Male; Mass Spectrometry; Mesentery; Middle Aged; Oxidation-Reduction; Oxidative Stress; Proteome; Proteomics; Tandem Mass Spectrometry; Wounds and Injuries; Young Adult
PubMed: 25243428
DOI: 10.1097/SHK.0000000000000249 -
Microvascular Research Nov 2014Lymphatic vasculature is necessary for maintaining fluid homeostasis in vertebrates. During embryogenesis lymphatic endothelial cells originate from the veins as a... (Review)
Review
Lymphatic vasculature is necessary for maintaining fluid homeostasis in vertebrates. During embryogenesis lymphatic endothelial cells originate from the veins as a homogeneous population. These cells undergo a series of changes at the morphological and molecular levels to become mature lymphatic vasculature that consists of lymphatic capillaries, collecting lymphatic vessels and valves. In this article we summarize our current knowledge about these steps and highlight some black boxes that require further clarification.
Topics: Animals; Cell Movement; Embryonic Development; Endothelial Cells; Humans; Immunohistochemistry; Lymph; Lymphangiogenesis; Lymphatic Vessels; Mice; Models, Biological; Neovascularization, Physiologic; Time Factors; Transcription Factors; Zebrafish
PubMed: 24928499
DOI: 10.1016/j.mvr.2014.06.002 -
The Journal of Physiology Dec 19711. Autografts and homografts of full thickness skin were made on a hind limb of rabbits. During the following days the appearance and histological changes of the grafts...
1. Autografts and homografts of full thickness skin were made on a hind limb of rabbits. During the following days the appearance and histological changes of the grafts were studied; the lymph flow from the limb, and the enzyme activities in the supernatant and cell pellet of the lymph after centrifugation were determined, as well as the enzyme activities in the graft roof and the underlying host tissue. It was further examined whether a lymphatic and vascular connexion occurred between graft and host tissue.2. During the first 5 days the grafts changed from pale blue to bright pink, became swollen, soft and had a mild cellular inflammatory exudate. Autografts then became pale, took on the appearance of normal skin with the inflammatory changes subsiding, whereas homografts became firm, showed heavy mononuclear cell infiltration, had a blotchy purple appearance due to thrombosis and haemorrhage, developed widespread necrosis and changed into a black hard scab which was eventually shed. With high dose homografts (6-8 grafts) these changes occurred 1-2 days earlier than with low dose (2-4) grafts.3. The flow of lymph increased during the first 5 days after grafting, then returned to normal with autografts but remained increased with homografts.4. In the supernatant of the lymph the activities of LDH and beta-glucuronidase did not change during the first 5 days but activities of cathepsin, acid phosphatase, GOT and GPT increased. With the autografts the increase in the activities of these four enzymes then subsided, but with the homografts they increased further and there was an increase in the activities of LDH and beta-glucuronidase, even greater than in those of the other four enzymes.5. In the cell pellets of the lymph the activities of the six enzymes did not increase during the first 5 days; with homografts, but not with autografts, they then increased. These increases occurred even though the cell count in the pellet remained unchanged. Thus some of the lymphocytes must have become ;activated' to contain higher enzyme activities.6. The enzyme activities in the roof tissue did not parallel those in lymph. They did not change during the first three days. During the following three days the activities of acid phosphatase, LDH, beta-glucuronidase and cathepsin increased, but not those of GOT and GPT which remained low. From then onwards the behaviour was different with auto- and homografts. With autografts only the activity of acid phosphatase continued to increase, those of LDH, beta-glucuronidase and cathepsin decreased and those of GOT and GPT remained low. With homografts the activities of LDH, beta-glucuronidase and cathepsin continued to increase and became even greater than in the supernatant of lymph, whereas the activities of acid phosphatase, GOT and GPT, remained low.7. In the bed tissue the activities of all six enzymes increased during the first 3 days after grafting, then the activities of GOT and GPT returned towards normal but those of the other four increased further. The only difference between auto- and homografts was that the increase in beta-glucuronidase and LDH activity was much greater with homografts.8. Lymph drainage became established with autografts on day 5 or 6 and then persisted. With homografts the dosage of grafts influenced the result. With low dosage (2-4 grafts) lymph drainage became established in a small percentage of the experiments, also on day 5 or 6, but it persisted for 2-3 days only. With high dosage, no lymph drainage became established. However, when the onset of rejection was delayed by treatment with cyclophosphamide lymph drainage became established also with high dosage homografts.9. Vascularization of the grafts was established on day 3 or 4, and persisted in autografts. In homografts a vascular shut down occurred at about the time of onset of rejection. It therefore occurred later with low than with high dosage and with high dosage on treatment with cyclophosphamide.10. It is concluded that the absence of lymph drainage from homografts is the cause of the small magnitude of increases in enzyme activities of lymph collected during and after their rejection. The increase results from ;activated' small lymphocytes which infiltrate the graft bed and junctional tissue and subsequently undergo necrosis, and that the establishment of a lymphatic connexion between the graft and host tissue is not a prerequisite for rejection.
Topics: Acid Phosphatase; Alanine Transaminase; Animals; Aspartate Aminotransferases; Cathepsins; Glucuronidase; Graft Rejection; Hemorrhage; Hindlimb; Inflammation; L-Lactate Dehydrogenase; Lymph; Lymphocytes; Necrosis; Rabbits; Skin; Skin Transplantation; Thrombosis; Time Factors; Transplantation, Autologous; Transplantation, Homologous; Wound Healing
PubMed: 4945593
DOI: 10.1113/jphysiol.1971.sp009676 -
The Journal of Nutrition Nov 2020Soybean lecithin, a plant-based emulsifier widely used in food, is capable of modulating postprandial lipid metabolism. With arising concerns of sustainability,...
BACKGROUND
Soybean lecithin, a plant-based emulsifier widely used in food, is capable of modulating postprandial lipid metabolism. With arising concerns of sustainability, alternative sources of vegetal lecithin are urgently needed, and their metabolic effects must be characterized.
OBJECTIVES
We evaluated the impact of increasing doses of rapeseed lecithin (RL), rich in essential α-linolenic acid (ALA), on postprandial lipid metabolism and ALA bioavailability in lymph-cannulated rats.
METHODS
Male Wistar rats (8 weeks old) undergoing a mesenteric lymph duct cannulation were intragastrically administered 1 g of an oil mixture containing 4% ALA and 0, 1, 3, 10, or 30% RL (5 groups). Lymph fractions were collected for 6 h. Lymph lipids and chylomicrons (CMs) were characterized. The expression of genes implicated in intestinal lipid metabolism was determined in the duodenum at 6 h. Data was analyzed using either sigmoidal or linear mixed-effects models, or one-way ANOVA, where appropriate.
RESULTS
RL dose-dependently increased the lymphatic recovery (AUC) of total lipids (1100 μg/mL·h per additional RL%; P = 0.010) and ALA (50 μg/mL·h per additional RL%; P = 0.0076). RL induced a faster appearance of ALA in lymph, as evidenced by the exponential decrease of the rate of appearance of ALA with RL (R2 = 0.26; P = 0.0064). Although the number of CMs was unaffected by RL, CM diameter was increased in the 30%-RL group, compared to the control group (0% RL), by 86% at 3-4 h (P = 0.065) and by 81% at 4-6 h (P = 0.0002) following administration. This increase was positively correlated with the duodenal mRNA expression of microsomal triglyceride transfer protein (Mttp; ρ= 0.63; P = 0.0052). The expression of Mttp and secretion-associated, ras-related GTPase 1 gene homolog B (Sar1b, CM secretion), carnitine palmitoyltransferase IA (Cpt1a) and acyl-coenzyme A oxidase 1 (Acox1, beta-oxidation), and fatty acid desaturase 2 (Fads2, bioconversion of ALA into long-chain n-3 PUFAs) were, respectively, 49%, 29%, 74%, 48%, and 55% higher in the 30%-RL group vs. the control group (P < 0.05).
CONCLUSIONS
In rats, RL enhanced lymphatic lipid output, as well as the rate of appearance of ALA, which may promote its subsequent bioavailability and metabolic fate.
Topics: Animals; Biological Availability; Brassica napus; Lecithins; Lipid Metabolism; Lymph; Rats; alpha-Linolenic Acid
PubMed: 32937654
DOI: 10.1093/jn/nxaa244 -
Clinical and Experimental Immunology May 1993Gut wall emigrating cells have been characterized in the intestinal lymph. The intestinal lymph duct was cannulated in 6-month-old minipigs. Under non-restraining...
Gut wall emigrating cells have been characterized in the intestinal lymph. The intestinal lymph duct was cannulated in 6-month-old minipigs. Under non-restraining conditions the efferent lymph from the mesenteric lymph nodes was collected in seven normal animals. Lymph coming directly from the gut (afferent lymph) was also collected in 18 pigs after resection of the mesenteric lymph node chains 3 months previously. The intestinal lymph flow was similar in both groups (around 18 ml/h). The lymphoid cell yield was 1.2 +/- 1.0 x 10(6)/h in control animals, while in mesenteric lymph node resected pigs it was around 20 times higher (26.2 +/- 17.6 x 10(6)/h). In the gut-derived lymph 76.5 +/- 8.8% T lymphocytes were observed (CD4+, 48.1 +/- 15.5%; CD8+, 53.6 +/- 12.7%). The percentage of immunoglobulin-positive cells was lower (IgM+, 10.1 +/- 4.5; IgA+, 1.7 +/- 1.1). In 14 mesenteric lymph node resected pigs a mean of 5.6 +/- 3.1 x 10(8) lymphocytes from the gut lymph were labelled in vitro with a fluorescent dye and retransfused. The labelling index of fluorescent cells in the intestinal lymph increased rapidly and remained at a high level until 44 h after cell transfusion. A four-to-ten times lower labelling index was found in the spleen, various lymph nodes and Peyer's patches. Most of the recovered lymphocytes were T cells. This model provides access to the cell pool leaving the gut wall, thus allowing an examination of its role in the gastrointestinal tract and other mucosal-lined organs.
Topics: Animals; Cell Movement; Female; Intestines; Lymph; Lymphocyte Subsets; Lymphoid Tissue; Peyer's Patches; Swine; Swine, Miniature
PubMed: 8485916
DOI: 10.1111/j.1365-2249.1993.tb03398.x -
Trends in Immunology Jan 2011Prenodal lymph is generated from the interstitial fluid that surrounds organs, and thus contains products of organ metabolism and catabolism. New proteomic analyses of...
Prenodal lymph is generated from the interstitial fluid that surrounds organs, and thus contains products of organ metabolism and catabolism. New proteomic analyses of lymph have identified proteins and peptides that are derived from capillary extravasation and tissue-specific proteins. Many of these peptides are detected at nanomolar concentrations in the lymph before passage through a regional lymph node. Before entering the node and once inside, proteins and processed peptides are filtered from the lymph by circulating immature dendritic cells (DCs) or non-activated nodal antigen-presenting cells (APCs) (macrophages, B cells and immature DCs). Here, we suggest that this process ensures organ-specific self-antigens are displayed to circulating and nodal APCs, thus contributing to the maintenance of peripheral tolerance.
Topics: Animals; Autoantigens; Humans; Immune Tolerance; Lymph; Lymphatic System; Major Histocompatibility Complex; Peptides; Proteome
PubMed: 21123113
DOI: 10.1016/j.it.2010.10.004 -
Cellular and Molecular Neurobiology Mar 2016The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain... (Review)
Review
The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain extracellular fluids, particularly interstitial fluid (ISF) and cerebrospinal fluid (CSF), is not only important for volume regulation, but also for removal of waste products such as amyloid beta (Aβ). CSF plays a special role in clinical medicine, as it is available for analysis of biomarkers for Alzheimer's disease. Despite the lack of a complete anatomical and physiological picture of the communications between the subarachnoid space (SAS) and the brain parenchyma, it is often assumed that Aβ is cleared from the cerebral ISF into the CSF. Recent work suggests that clearance of the brain mainly occurs during sleep, with a specific role for peri- and para-vascular spaces as drainage pathways from the brain parenchyma. However, the direction of flow, the anatomical structures involved and the driving forces remain elusive, with partially conflicting data in literature. The presence of Aβ in the glia limitans in Alzheimer's disease suggests a direct communication of ISF with CSF. Nonetheless, there is also the well-described pathology of cerebral amyloid angiopathy associated with the failure of perivascular drainage of Aβ. Herein, we review the role of the vasculature and the impact of vascular pathology on the peri- and para-vascular clearance pathways of the brain. The different views on the possible routes for ISF drainage of the brain are discussed in the context of pathological significance.
Topics: Animals; Brain; Cerebrovascular Circulation; Humans; Lymph; Models, Biological; Neurodegenerative Diseases
PubMed: 26993512
DOI: 10.1007/s10571-015-0273-8 -
The Journal of Pharmacology and... Nov 2019Doxorubicin is a risk factor for secondary lymphedema in cancer patients exposed to surgery or radiation. The risk is presumed to relate to its cytotoxicity. However,...
Doxorubicin is a risk factor for secondary lymphedema in cancer patients exposed to surgery or radiation. The risk is presumed to relate to its cytotoxicity. However, the present study provides initial evidence that doxorubicin directly inhibits lymph flow and this action appears distinct from its cytotoxic activity. We used real-time edge detection to track diameter changes in isolated rat mesenteric lymph vessels. Doxorubicin (0.5-20 mol/l) progressively constricted lymph vessels and inhibited rhythmic contractions, reducing flow to 24.2% ± 7.7% of baseline. The inhibition of rhythmic contractions by doxorubicin paralleled a tonic rise in cytosolic Ca concentration in lymphatic muscle cells, which was prevented by pharmacological antagonism of ryanodine receptors. Washout of doxorubicin partially restored lymph vessel contractions, implying a pharmacological effect. Subsequently, high-speed optical imaging was used to assess the effect of doxorubicin on rat mesenteric lymph flow in vivo. Superfusion of doxorubicin (0.05-10 mol/l) maximally reduced volumetric lymph flow to 34% ± 11.6% of baseline. Likewise, doxorubicin (10 mg/kg) administered intravenously to establish clinically achievable plasma concentrations also maximally reduced volumetric lymph flow to 40.3% ± 6.0% of initial values. Our findings reveal that doxorubicin at plasma concentrations achieved during chemotherapy opens ryanodine receptors to induce "calcium leak" from the sarcoplasmic reticulum in lymphatic muscle cells and reduces lymph flow, an event linked to lymph vessel damage and the development of lymphedema. These results infer that pharmacological block of ryanodine receptors in lymphatic smooth muscle cells may mitigate secondary lymphedema in cancer patients subjected to doxorubicin chemotherapy. SIGNIFICANCE STATEMENT: Doxorubicin directly inhibits the rhythmic contractions of collecting lymph vessels and reduces lymph flow as a possible mechanism of secondary lymphedema, which is associated with the administration of anthracycline-based chemotherapy. The inhibitory effects of doxorubicin on rhythmic contractions and flow in isolated lymph vessels were prevented by pharmacological block of ryanodine receptors, thereby identifying the ryanodine receptor family of proteins as potential therapeutic targets for the development of new antilymphedema medications.
Topics: Animals; Antibiotics, Antineoplastic; Dose-Response Relationship, Drug; Doxorubicin; Lymph; Lymphatic Vessels; Male; Muscle Cells; Muscle Contraction; Organ Culture Techniques; Rats; Rats, Sprague-Dawley; Ryanodine Receptor Calcium Release Channel
PubMed: 31439806
DOI: 10.1124/jpet.119.257592