Identification of pregnancy-associated glycoprotein family (PAG) in the brown bear (Ursus arctos L.)

Grzegorz Panasiewicz; Aleksandra Lipka; Marta Majewska; Martyna Bieniek-Kobuszewska; Alexander P Saveljev; Bozena Szafranska

doi:10.1016/j.acthis.2018.12.008

Identification of pregnancy-associated glycoprotein family (PAG) in the brown bear (Ursus arctos L.)

Acta Histochem. 2019 Feb;121(2):240-247. doi: 10.1016/j.acthis.2018.12.008. Epub 2019 Jan 5.

Authors

Grzegorz Panasiewicz¹, Aleksandra Lipka², Marta Majewska³, Martyna Bieniek-Kobuszewska⁴, Alexander P Saveljev⁵, Bozena Szafranska⁶

Affiliations

¹ Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Str 1A, 10-719 Olsztyn-Kortowo, Poland. Electronic address: panasg@uwm.edu.pl.
² Department of Gynecology and Obstetrics, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Niepodleglosci Str 44, 10-045 Olsztyn, Poland.
³ Department of Human Physiology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Warszawska Str 30, 10-082 Olsztyn, Poland.
⁴ Department of Dermatology, Sexually Transmitted Diseases and Clinical Immunology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Wojska Polskiego Str 30, 10-229 Olsztyn, Poland.
⁵ Department of Animal Ecology, Russian Research Institute of Game Management and Fur Farming, Preobrazhenskaya Str 79, 610000 Kirov, Russian Federation.
⁶ Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Str 1A, 10-719 Olsztyn-Kortowo, Poland.

PMID: 30616842
DOI: 10.1016/j.acthis.2018.12.008

Abstract

Pregnancy-associated glycoproteins (PAGs) are abundant embryo-originated products expressed in the pre-placental trophoblast and, later, in the post-implantational chorionic epithelium of some mammalian species. This paper describes the identification and cellular immunolocalization of the chorionic PAG family in the discoidal-type placenta of the brown bear (Ursus arctos L. - Ua), in which the PAGs were named 'UaPAG-Ls'. The study used: 1) Western blot for total placental glycoproteins; and 2) cross-species heterologous double fluorescent immunohistochemistry (IHC) for cellular immune-localization of the PAGs. This is the first study reporting the identification and immunolocalization of the UaPAG-L family in placental cells during early pregnancy in the brown bear. Our Western analysis revealed a dominant mature 72 kDa UaPAG-L isoform was expressed in all Ua placentas during early pregnancy. Various other UaPAG-L isoforms (16-66 kDa) were also identified. Using IHC, the UaPAG-L proteins were localized to trophectodermal cells (TRD), where signal intensity resembled intense TRD proliferation within developing placenta. The data increases our general knowledge of PAG proteins localized in discoidal-type placenta during early pregnancy in the brown bear.

Keywords: Brown bear; PAGs; Placenta; Ursus arctos.

MeSH terms

Animals
Chorion / metabolism
Epithelium / metabolism*
Female
Glycoproteins / urine*
Placenta / metabolism*
Pregnancy
Pregnancy Proteins / urine*
Trophoblasts / physiology
Ursidae / urine*

Substances

Glycoproteins
Pregnancy Proteins