title: CD36 regulates lipopolysaccharide-induced signaling pathways and mediates the internalization of Escherichia coli in cooperation with TLR4 in goat mammary gland epithelial cells.
abstract: The scavenger receptor CD36 is involved in pathogen recognition, phagocytosis, and pathogen-induced signaling. This study investigated the relationship between CD36 and TLR4 in modifying lipopolysaccharide (LPS)-induced signaling pathways and mediating Escherichia coli (E. coli) endocytosis in primary goat mammary epithelial cells (pGMECs). The manipulation of CD36 expression significantly influenced TLR4 and nuclear factor kappa B (NF-κB) mRNA expression in pGMECs stimulated with LPS for 12 h. NF-κB and activator protein-1 (AP-1) activity was regulated by the manipulation of CD36 expression in LPS-induced pGMECs. However, CD36-mediated AP-1 activation occurred primarily through c-Jun N-terminal kinase (c-JNK). Adaptor proteins and proinflammatory cytokines were also involved in these signaling pathways and acted by regulating CD36 expression in LPS-stimulated cells. Moreover, CD36 cooperated with TLR4 in TLR4-mediated phagocytosis following E. coli simulation, but this complex was not induced by LPS treatment. Our study is the first to illuminate CD36 as a scavenger receptor in ruminants. Additionally, this study indicates that CD36 plays a vital role in the LPS-induced activation of downstream signaling cascades and mediates E. coli phagocytosis via TLR4 in pGMECs, which offers a novel treatment strategy for mastitis.
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Duoyao
authors.initials: D
authors.lastname: Cao
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Dekun
authors.initials: D
authors.lastname: Chen
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Huifen
authors.initials: H
authors.lastname: Xu
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Huaiping
authors.initials: H
authors.lastname: Shi
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Jing
authors.affiliation: Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, PR China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Zang
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D004926:Escherichia coli / Q000502:physiology*; D005260:Female; D006041:Goats; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000382:microbiology*; D016328:NF-kappa B / Q000378:metabolism; D010587:Phagocytosis; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D018955:CD36 Antigens; D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D051197:Toll-Like Receptor 4; D018808:Transcription Factor AP-1; D048031:JNK Mitogen-Activated Protein Kinases