Trophoblast of domestic and companion nimals: basic and applied clinical perspectives

Abstract

The trophoblast is the single most important functional structure of the placenta that mediates the attachment of the blastocyst to the endometrium. Trophoblast has the capability to proliferate in concert with the uterine epithelium to form the only site for nutrient and metabolic exchange between the fetus and dam throughout pregnancy. Trophoblast is made up of a remarkable versatile epithelium showing great capacity for invasion, cell fusion, hormone production, specific nutrient absorption, selective transport, active metabolism, and has the ability to resist maternal immunological attack. These functions are attributed to its inherent ability to synthesize many developmental factors or molecular regulators. While there is an abundance of publications available on the structural, functional, and clinical relevance of the placenta in various mammalian species, a comprehensive review on the comparative aspects of the trophoblast of domestic and companion animals is lacking. Besides, a timely description on the clinical perspective on the functional aspects of the trophoblast in relation to pregnancy diagnosis, placental insufficiency, pregnancy loss, and structural abnormalities of domestic and companion animals is necessary. A brief description on the basic chronology of events in each animal is followed by the applied clinical perspectives of trophoblast. Both the above aspects of trophoblasts of domestic and companion animals including the terminologies are summarized in tables to facilitate discussion.

Determining MMP‐2 and MMP‐9 reductive activities of bovine and equine amniotic membranes homogenates using fluorescence resonance energy transfer

“…TIMP‐2 and −3 were detected in both species' AMH, while TIMP‐1 was detected only in BAMH, and TIMP‐4 was not detectable in either AMH. In contrast, TIMP‐1, −2, −3, and −4 were identified in human amnion chorionic membranes in previous studies 32,33 . Homologs of human TIMPs are reported to be widely distributed in the placenta 33 and present in corneal epithelial cells and endothelium (TIMPs −1, −2, and −3) keratocytes (TIMP −2) 6 …”

“…In contrast, TIMP-1, −2, −3, and −4 were identified in human amnion chorionic membranes in previous studies. 32,33 Homologs of human TIMPs are reported to be widely distributed in the placenta 33 and present in corneal epithelial cells and endothelium (TIMPs −1, −2, and −3) keratocytes (TIMP −2). 6 Expression of TIMPs in fetal membranes is paramount for placental growth and remodeling.…”

Do uterine PTGS2, PGFS, and PTGFR expression play a role in canine uterine inertia?

“…Interestingly, some variation between animals and groups was observed in foetal trophoblast cell staining in a relatively small sample size. Recently, the comparative functions of placental trophoblast cells had been reviewed in different animal species, such as ruminants, pig, horse, dog, and cat (Peter et al 2017 ). This review clearly summarizes our still restricted understanding of this cell population in animal reproduction in general, but also specifically in canine parturition.…”

Synergistic effect of basic fibroblast growth factor (bFGF) and epidermal growth factor on derivation of camel (Camelus dromedarius) trophoblast stem cells

“…Preimplantation embryo-derived stem cells are a good tool for studying early developmental biology and for biomedical research and genetic engineering in mammalian species (Blomberg & Telugu, 2012). Trophoblast stem cells are the first cells to differentiate from the embryo, have oligopotent stem cell characteristics, contribute to the formation of the fetal parts of the placenta and fetal membranes, and have the capacity to self-renew indefinitely (Latos & Hemberger, 2016;Peter et al, 2017). Camel (Camelus dromedarius) is an important mammalian species in the Arabian Peninsula and some other African and Asian countries because it can tolerate harsh arid conditions with maintaining meat and milk production.…”