title: Lipopolysaccharide modulates neutrophil recruitment and macrophage polarization on lymphatic vessels and impairs lymphatic function in rat mesentery.
abstract: Impairment of the lymphatic system is apparent in multiple inflammatory pathologies connected to elevated endotoxins such as LPS. However, the direct mechanisms by which LPS influences the lymphatic contractility are not well understood. We hypothesized that a dynamic modulation of innate immune cell populations in mesentery under inflammatory conditions perturbs tissue cytokine/chemokine homeostasis and subsequently influences lymphatic function. We used rats that were intraperitoneally injected with LPS (10 mg/kg) to determine the changes in the profiles of innate immune cells in the mesentery and in the stretch-mediated contractile responses of isolated lymphatic preparations. Results demonstrated a reduction in the phasic contractile activity of mesenteric lymphatic vessels from LPS-injected rats and a severe impairment of lymphatic pump function and flow. There was a significant reduction in the number of neutrophils and an increase in monocytes/macrophages present on the lymphatic vessels and in the clear mesentery of the LPS group. This population of monocytes and macrophages established a robust M2 phenotype, with the majority showing high expression of CD163 and CD206. Several cytokines and chemoattractants for neutrophils and macrophages were significantly changed in the mesentery of LPS-injected rats. Treatment of lymphatic muscle cells (LMCs) with LPS showed significant changes in the expression of adhesion molecules, VCAM1, ICAM1, CXCR2, and galectin-9. LPS-TLR4-mediated regulation of pAKT, pERK pI-κB, and pMLC20 in LMCs promoted both contractile and inflammatory pathways. Thus, our data provide the first evidence connecting the dynamic changes in innate immune cells on or near the lymphatics and complex cytokine milieu during inflammation with lymphatic dysfunction.
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and.
authors.forename: Sanjukta
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Zawieja
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and.
authors.forename: Yang
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Physiology and Pharmacology, Inflammation Research Network, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Yuan J
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: Department of Physiology and Pharmacology, Inflammation Research Network, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: von der Weid
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and.
authors.forename: David C
authors.initials: DC
authors.lastname: Zawieja
authors.affiliation: Department of Medical Physiology, Cardiovascular Research Institute, Division of Lymphatic Biology, Texas A&M Health Science Center College of Medicine, College Station, Texas; and marim@email.tamu.edu.
authors.forename: Mariappan
authors.initials: M
authors.lastname: Muthuchamy
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D016764:Cell Polarity / Q000187:drug effects*; D018925:Chemokines / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D007113:Immunity, Innate / Q000187:drug effects; D066298:In Vitro Techniques; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008206:Lymphatic Diseases / Q000139:chemically induced* / Q000473:pathology; D042601:Lymphatic Vessels / Q000166:cytology / Q000187:drug effects*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects*; D008297:Male; D008643:Mesentery / Q000473:pathology*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D020556:Neutrophil Infiltration / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015815:Cell Adhesion Molecules; D018925:Chemokines; D016207:Cytokines; D008070:Lipopolysaccharides
keywords: M1 and M2 macrophages; inflammation; lipopolysaccharide; lymphatic function; neutrophils