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Cellular and Molecular Gastroenterology... 2019Rapid and efficient digestion and absorption of dietary triglycerides and other lipids by the intestine, the packaging of those lipids into lipoprotein chylomicron (CM)... (Review)
Review
Rapid and efficient digestion and absorption of dietary triglycerides and other lipids by the intestine, the packaging of those lipids into lipoprotein chylomicron (CM) particles, and their secretion via the lymphatic duct into the blood circulation are essential in maintaining whole-body lipid and energy homeostasis. Biosynthesis and assembly of CMs in enterocytes is a complex multistep process that is subject to regulation by intracellular signaling pathways as well as by hormones, nutrients, and neural factors extrinsic to the enterocyte. Dysregulation of this process has implications for health and disease, contributing to dyslipidemia and a potentially increased risk of atherosclerotic cardiovascular disease. There is increasing recognition that, besides intracellular regulation of CM assembly and secretion, regulation of postassembly pathways also plays important roles in CM secretion. This review examines recent advances in our understanding of the regulation of CM secretion in relation to mobilization of intestinal lipid stores, drawing particular attention to post-assembly regulatory mechanisms, including intracellular trafficking of triglycerides in enterocytes, CM mobilization from the lamina propria, and regulated transport of CM by intestinal lymphatics.
Topics: Animals; Biological Transport; Chylomicrons; Dietary Fats; Humans; Lipid Metabolism; Lymph; Mucous Membrane
PubMed: 30819663
DOI: 10.1016/j.jcmgh.2018.10.015 -
Journal of Immunology (Baltimore, Md. :... Oct 2019Unlike the blood, the interstitial fluid and the deriving lymph are directly bathing the cellular layer of each organ. As such, composition analysis of the lymphatic...
Unlike the blood, the interstitial fluid and the deriving lymph are directly bathing the cellular layer of each organ. As such, composition analysis of the lymphatic fluid can provide more precise biochemical and cellular information on an organ's health and be a valuable resource for biomarker discovery. In this study, we describe a protocol for cannulation of mouse and rat lymphatic collectors that is suitable for the following: the "omic" sampling of pre- and postnodal lymph, collected from different anatomical districts; the phenotyping of immune cells circulating between parenchymal organs and draining lymph nodes; injection of known amounts of molecules for quantitative immunological studies of nodal trafficking and/or clearance; and monitoring an organ's biochemical omic changes in pathological conditions. Our data indicate that probing the lymphatic fluid can provide an accurate snapshot of an organ's physiology/pathology, making it an ideal target for liquid biopsy.
Topics: Animals; Catheterization; Female; Lymph; Lymph Nodes; Lymphatic Vessels; Male; Mice; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley
PubMed: 31519866
DOI: 10.4049/jimmunol.1900375 -
Methods (San Diego, Calif.) Jun 2014Analyses of the Drosophila hematopoietic system are becoming more and more prevalent as developmental and functional parallels with vertebrate blood cells become more... (Review)
Review
Analyses of the Drosophila hematopoietic system are becoming more and more prevalent as developmental and functional parallels with vertebrate blood cells become more evident. Investigative work on the fly blood system has, out of necessity, led to the identification of new molecular markers for blood cell types and lineages and to the refinement of useful molecular genetic tools and analytical methods. This review briefly describes the Drosophila hematopoietic system at different developmental stages, summarizes the major useful cell markers and tools for each stage, and provides basic protocols for practical analysis of circulating blood cells and of the lymph gland, the larval hematopoietic organ.
Topics: Animals; Cell Lineage; Developmental Biology; Drosophila; Hematopoiesis; Larva; Lymph
PubMed: 24613936
DOI: 10.1016/j.ymeth.2014.02.038 -
Life Sciences Aug 2023Chronic alcohol consumption in rodents induces mesenteric collecting lymphatic vessel hyperpermeability, lymph leakage, and consequent immunometabolic dysregulation of...
Chronic alcohol consumption in rodents induces mesenteric collecting lymphatic vessel hyperpermeability, lymph leakage, and consequent immunometabolic dysregulation of the perilymphatic adipose tissue (PLAT). The specific lymphatic components mediating PLAT immunometabolic dysregulation remain to be identified. Specifically, whether alcohol impacts lymph composition is unknown. This study aimed to determine alcohol associated changes in lymph and plasma proteome. Adult male rats were fed a Lieber-DeCarli liquid diet containing 36 % of calories from alcohol for 10 weeks. Time-matched control animals were pair-fed. At sacrifice lymph was collected for 2 h using the lymph-fistula technique and plasma was collected prior to sacrifice. Quantitative discovery-based proteomics identified a total of 703 proteins. An integrative approach combining Ingenuity Pathway Analysis (IPA) and an unbiased network analysis using WGCNA (Weighted Gene Co-expression Network Analysis) was used to analyze the proteomics data. IPA results identified significant upregulation of a cluster of apolipoproteins in lymph from alcohol-fed animals compared with pair-fed controls and a downregulation of 34 proteins in the plasma from alcohol-fed animals. WGCNA analysis identified several candidate hub proteins in the lymph that were also significantly differentially expressed in lymph from alcohol-fed animals compared to that of pair-fed controls. WGCNA analysis of plasma identified a module without significant enrichment of differentially expressed proteins. Of the 59 proteins contained within this module, only 2 were significantly differentially expressed in plasma from alcohol-fed rats compared to plasma of pair-fed controls. Future studies will investigate further the functionality of the hub proteins affected by alcohol feeding in both lymph and plasma.
Topics: Rats; Male; Animals; Proteome; Rodentia; Ethanol; Lymph; Lymphatic Vessels
PubMed: 37268288
DOI: 10.1016/j.lfs.2023.121818 -
Cells Jun 2021Neutrophils are the first immune cells to be recruited from the blood to the tissue site of an infection or inflammation. It has been suggested that neutrophils are...
Neutrophils are the first immune cells to be recruited from the blood to the tissue site of an infection or inflammation. It has been suggested that neutrophils are capable of migrating from the infected tissue via lymphatic vessels to the draining lymph nodes. However, it remains elusive as to which areas within the lymph nodes can be reached by such reversely migrating cells. To address this question, we applied a model for adoptive neutrophil transfer into the afferent lymphatic vessel that drains towards the popliteal lymph node in mice. We showed that resting and in vitro-activated neutrophils did not enter the lymph node parenchyma but localized primarily in the subcapsular and medullary sinuses. Within the medulla, neutrophils show random migration and are able to sense laser-induced sterile tissue injury by massively swarming to the damaged tissue site. Co-injected dendritic cells supported the entry of resting neutrophils into the lymph node parenchyma via the subcapsular sinus. In contrast, in vivo-activated adoptively transferred neutrophils were capable of migrating into the interfollicular areas of the lymph node. Collectively, the data presented here give further insights into the functional behavior of neutrophils within the lymph nodes.
Topics: Animals; Cell Movement; Lymph; Lymph Nodes; Mice; Mice, Inbred C57BL; Neutrophils
PubMed: 34204825
DOI: 10.3390/cells10061486 -
Scientific Reports Jul 2016Direct in vivo imaging of lymph flow is key to understanding lymphatic system function in normal and disease states. Optical microscopy techniques provide the resolution...
Direct in vivo imaging of lymph flow is key to understanding lymphatic system function in normal and disease states. Optical microscopy techniques provide the resolution required for these measurements, but existing optical techniques for measuring lymph flow require complex protocols and provide limited temporal resolution. Here, we describe a Doppler optical coherence tomography platform that allows direct, label-free quantification of lymph velocity and volumetric flow rates. We overcome the challenge of very low scattering by employing a Doppler algorithm that operates on low signal-to-noise measurements. We show that this technique can measure lymph velocity at sufficiently high temporal resolution to resolve the dynamic pulsatile flow in collecting lymphatic vessels.
Topics: Algorithms; Animals; Ear, External; Female; Lower Extremity; Lymph; Lymphatic System; Male; Mice, Inbred C3H; Mice, Nude; Pulsatile Flow; Tomography, Optical Coherence
PubMed: 27377852
DOI: 10.1038/srep29035 -
Proceedings of the National Academy of... Apr 2017Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in...
Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog showing that fluorescence in living frogs is produced by a combination of lymph and glandular emission, with pigmentary cell filtering in the skin. The chemical origin of fluorescence was traced to a class of fluorescent compounds derived from dihydroisoquinolinone, here named hyloins. We show that fluorescence contributes 18-29% of the total emerging light under twilight and nocturnal scenarios, largely enhancing brightness of the individuals and matching the sensitivity of night vision in amphibians. These results introduce an unprecedented source of pigmentation in amphibians and highlight the potential relevance of fluorescence in visual perception in terrestrial environments.
Topics: Animals; Anura; Fluorescence; Lymph; Magnetic Resonance Spectroscopy; Night Vision; Skin
PubMed: 28289227
DOI: 10.1073/pnas.1701053114 -
Biomechanics and Modeling in... Apr 2014We present a mathematical model of blood and interstitial flow in the liver. The liver is treated as a lattice of hexagonal 'classic' lobules, which are assumed to be...
We present a mathematical model of blood and interstitial flow in the liver. The liver is treated as a lattice of hexagonal 'classic' lobules, which are assumed to be long enough that end effects may be neglected and a two-dimensional problem considered. Since sinusoids and lymphatic vessels are numerous and small compared to the lobule, we use a homogenized approach, describing the sinusoidal and interstitial spaces as porous media. We model plasma filtration from sinusoids to the interstitium, lymph uptake by lymphatic ducts, and lymph outflow from the liver surface. Our results show that the effect of the liver surface only penetrates a depth of a few lobules' thickness into the tissue. Thus, we separately consider a single lobule lying sufficiently far from all external boundaries that we may regard it as being in an infinite lattice, and also a model of the region near the liver surface. The model predicts that slightly more lymph is produced by interstitial fluid flowing through the liver surface than that taken up by the lymphatic vessels in the liver and that the non-peritonealized region of the surface of the liver results in the total lymph production (uptake by lymphatics plus fluid crossing surface) being about 5% more than if the entire surface were covered by the Glisson-peritoneal membrane. Estimates of lymph outflow through the surface of the liver are in good agreement with experimental data. We also study the effect of non-physiological values of the controlling parameters, particularly focusing on the conditions of portal hypertension and ascites. To our knowledge, this is the first attempt to model lymph production in the liver. The model provides clinically relevant information about lymph outflow pathways and predicts the systemic response to pathological variations.
Topics: Blood; Extracellular Fluid; Liver; Lymph; Models, Statistical
PubMed: 23907149
DOI: 10.1007/s10237-013-0516-x -
Cytometry. Part a : the Journal of the... Oct 2011Flow cytometry (FCM) has been a fundamental tool of biological discovery for many years. Invasive extraction of cells from a living organism, however, may lead to... (Review)
Review
Flow cytometry (FCM) has been a fundamental tool of biological discovery for many years. Invasive extraction of cells from a living organism, however, may lead to changes in cell properties and prevents studying cells in their native environment. These problems can be overcome by use of in vivo FCM, which provides detection and imaging of circulating normal and abnormal cells directly in blood or lymph flow. The goal of this review is to provide a brief history, features, and challenges of this new generation of FCM methods and instruments. Spectrum of possibilities of in vivo FCM in biological science (e.g., cell metabolism, immune function, or apoptosis) and medical fields (e.g., cancer, infection, and cardiovascular disorder) including integrated photoacoustic-photothermal theranostics of circulating abnormal cells are discussed with focus on recent advances of this new platform.
Topics: Animals; Cardiovascular Diseases; Flow Cytometry; Fluorescence; Humans; Lasers; Lymph; Magnetic Resonance Imaging; Mice; Molecular Imaging; Nanoparticles; Neoplasms; Photoacoustic Techniques; Rheology; Signal Processing, Computer-Assisted; Spectrum Analysis, Raman; Staining and Labeling; Ultrasonography
PubMed: 21915991
DOI: 10.1002/cyto.a.21143 -
Trends in Endocrinology and Metabolism:... Aug 2010The lymphatics began receiving attention in the scientific community as early as 1622, when Gasparo Aselli noted the appearance of milky-white vessels in the mesentery... (Review)
Review
The lymphatics began receiving attention in the scientific community as early as 1622, when Gasparo Aselli noted the appearance of milky-white vessels in the mesentery of a well-fed dog. Since this time, the lymphatic system has been historically regarded as the sewer of the vasculature, passively draining fluid and proteins from the interstitial spaces (along with lipid from the gut) into the blood. Recent reports, however, suggest that the lymphatic role in lipid transport is an active and intricate process, and that when lymphatic function is compromised, there are systemic consequences to lipid metabolism and transport. This review highlights these recent findings, and suggests future directions for understanding the interplay between lymphatic and lipid biology in health and disease.
Topics: Animals; Digestive System Physiological Phenomena; Humans; Lipid Metabolism; Lipid Metabolism Disorders; Lymph; Lymphatic Diseases; Lymphatic System; Lymphatic Vessels
PubMed: 20541951
DOI: 10.1016/j.tem.2010.04.003