title: An acute-phase protein as a regulator of sperm survival in the bovine oviduct: alpha 1-acid-glycoprotein impairs neutrophil phagocytosis of sperm in vitro.
abstract: We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP gene was expressed in cultured bovine oviduct epithelial cells (BOECs) and AGP protein was detected in oviduct fluid. Preexposure of PMNs to AGP at physiological levels impaired PMN phagocytosis for sperm and superoxide generation. The desialylation of AGP eliminated these suppressive effects of AGP on PMN. Scanning electron microscopy revealed that AGP drastically reduced the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. Additionally, AGP dose-dependently stimulated BOECs to produce prostaglandin E2 (PGE2) which has been shown to partially contribute to the regulation of sperm phagocytosis in the bovine oviduct. AGP and PGE2 at concentrations detected in the oviducts additively suppressed sperm phagocytosis by PMNs. These results provide evidence that locally produced AGP may be involved in protecting sperm from phagocytosis by PMNs in the bovine oviduct.
authors.affiliation: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Liu
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Marey
authors.forename: Rasoul
authors.initials: R
authors.lastname: Kowsar
authors.forename: Nina
authors.initials: N
authors.lastname: Hambruch
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Shingo
authors.initials: S
authors.lastname: Haneda
authors.forename: Motozumi
authors.initials: M
authors.lastname: Matsui
authors.forename: Motoki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hayakawa
authors.forename: Christiane
authors.initials: C
authors.lastname: Pfarrer
authors.forename: Akio
authors.initials: A
authors.lastname: Miyamoto
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000737:chemistry; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D015232:Dinoprostone / Q000096:biosynthesis; D004847:Epithelial Cells / Q000378:metabolism; D065206:Extracellular Traps / Q000187:drug effects; D005187:Fallopian Tubes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D007109:Immunity / Q000187:drug effects; D008297:Male; D008855:Microscopy, Electron, Scanning; D019158:N-Acetylneuraminic Acid; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D009961:Orosomucoid / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D010587:Phagocytosis / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D013094:Spermatozoa / Q000276:immunology* / Q000502:physiology; D013329:Structure-Activity Relationship; D013481:Superoxides / Q000378:metabolism
chemical_list: D009961:Orosomucoid; D012333:RNA, Messenger; D013481:Superoxides; D019158:N-Acetylneuraminic Acid; D015232:Dinoprostone