1. Heparin fragments induce cervical inflammation by recruiting immune cells through Toll-like receptor 4 in nonpregnant mice.
- Author
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Åkerud A, Axelsson J, Yadav M, Erjefält J, Ekman-Ordeberg G, Malmström A, and Fischer H
- Subjects
- Animals, Cervical Ripening, Cervix Uteri immunology, Cervix Uteri metabolism, Female, Heparin analogs & derivatives, Immunity, Innate drug effects, Inflammation genetics, Inflammation immunology, Inflammation metabolism, Interferon Regulatory Factor-3 genetics, Interferon Regulatory Factor-3 metabolism, Macrophages immunology, Macrophages metabolism, Mice, Inbred C57BL, Mice, Knockout, Myeloid Differentiation Factor 88 genetics, Myeloid Differentiation Factor 88 metabolism, Neutrophils immunology, Neutrophils metabolism, Pregnancy, Signal Transduction, Toll-Like Receptor 4 genetics, Mice, Cell Movement drug effects, Cervix Uteri drug effects, Heparin pharmacology, Inflammation chemically induced, Macrophages drug effects, Neutrophil Infiltration drug effects, Neutrophils drug effects, Toll-Like Receptor 4 metabolism
- Abstract
Inflammation is a hallmark in the human cervix remodelling. A possible candidate inducing the inflammatory driven ripening of the cervix is the matrix component heparan sulphate, which has been shown to be elevated in late pregnancy in the cervix and uterus. Heparin and a glycol-split low molecular weight heparin (gsHep) with low anticoagulant potency has been shown to enhance myometrial contraction and interleukin (IL)-8 production by cervical fibroblasts. The aim of this study was to investigate the mechanism by which heparin promotes cervical inflammation. Wild-type, Toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88) and Interferon regulatory factor 3 (IRF3)-deficient mice were treated by deposition of gsHep into the vaginas of nonpregnant mice. To identify which cells that responded to the heparin fragments, a rhodamine fluorescent construct of gsHep was used, which initially did bind to the epithelial cells and were at later time points located in the sub-mucosa. The heparin fragments induced a strong local inflammatory response in wild-type mice shown by a rapid infiltration of neutrophils and to a lesser extent macrophages into the epithelium and the underlying extracellular matrix of the cervix. Further, a marked migration into the cervical and vaginal lumen was seen by both neutrophils and macrophages. The induced mucosal inflammation was strongly reduced in TLR4- and IRF3-deficient mice. In conclusion, our findings suggest that a TLR4/IRF3-mediated innate immune response in the cervical mucosa is induced by gsHep. This low anticoagulant heparin version, a novel TLR4 agonist, could contribute to human cervical ripening during the initiation of labour., (© The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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