It's a small world for parasites: evidence supporting the North American invasion of European Echinococcus multilocularis.

Echinococcus multilocularis (Em), the causative agent of human alveolar echinococcosis (AE), is present in the Holarctic region, and several genetic variants deem to have differential infectivity and pathogenicity. An unprecedented outbreak of human AE cases in Western Canada infected with a European-like strain circulating in wild hosts warranted assessment of whether this strain was derived from a recent invasion or was endemic but undetected. Using nuclear and mitochondrial markers, we investigated the genetic diversity of Em in wild coyotes and red foxes from Western Canada, compared the genetic variants identified to global isolates and assessed their spatial distribution to infer possible invasion dynamics. Genetic variants from Western Canada were closely related to the original European clade, with lesser genetic diversity than that expected for a long-established strain and spatial genetic discontinuities within the study area, supporting the hypothesis of a relatively recent invasion with various founder events.

Fibrinogen in equine pregnancy as a mediator of cell adhesion, an epigenetic and functional investigation.

Preimplantation equine embryos synthesize and secrete fibrinogen, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. This study investigated the hypothesis that conceptus-derived fibrinogen mediates cell adhesion during fixation. On day 21 of pregnancy, five integrin subunits, including ITGA5, ITGB1, ITGAV, and ITGB1, displayed significantly higher transcript abundance than on day 16 of pregnancy. Endometrial epithelial cells adhered to fibrinogen in an integrin-dependent manner in an in vitro cell adhesion assay. Bilaminar trophoblast and allantochorion expressed fibrinogen transcript, indicating that fibrinogen expression persists past fixation. Preimplantation-phase endometrium, conceptuses, and microcotyledonary tissue expressed components of the clotting cascade regulating fibrin homeostasis, leaving open the possibility that fibrinogen is converted to fibrin. Fibrinogen is likely to have functions beyond mediating cell adhesion, such trapping growth factors and triggering signaling cascades, and has remarkable parallels to the expression of fibrinogen by some tumors. The deposition of fibrinogen within tumor stroma is characteristic of breast carcinoma, and tumor-derived fibrinogen has been implicated in the metastatic potential of circulating tumor cells. DNA methylation of the fibrinogen locus in equine conceptuses was examined in comparison to liver and endometrium, and across the full gene cluster, was significantly higher for endometrium than liver and conceptus. DNA methylation of regulatory regions did not differ between liver and conceptus, and was significantly lower than in endometrium. These results, therefore, support the hypothesis of DNA methylation being a regulator of fibrinogen expression in the conceptus.

Interferon epsilon is constitutively expressed in equine endometrium and up-regulated during the luteal phase.

Interferon epsilon (IFNE) is type I interferon which stands out through its unusual expression profile and differing regulation compared to classic type I interferons such as interferon alpha and interferon beta. Unlike other type I interferons, the expression of IFNE is not stimulated through exposure to viral agents. Expression of IFNE is most abundant in mouse and human endometrium where it is constitutively expressed in luminal and glandular epithelial cells and expression levels are up-regulated with estrogen exposure. The aim of the current study was to determine whether a cycle or pregnancy dependent expression pattern of IFNE is existent in equine endometrium and to localize IFNE expression within the endometrium. Additionally, endometrial explant culture and culture of mixed epithelial/stromal cells populations was used to determine the effects estrogen and seminal plasma on IFNE transcript abundance. Samples collected during diestrus and pregnancy expressed significantly higher levels of IFNE than samples obtained from anestrous or estrous mares (P < 0.001). Exposure of mixed endometrial epithelial/stromal cell populations and endometrial explants to 10% seminal plasma and estradiol 17-beta did not affect IFNE expression levels (P > 0.05). Upon in situ hybridization, staining was exclusively present in luminal and glandular epithelial cells, with stromal displaying absent staining intensity. Both diestrous and pregnant samples were characterized by markedly stronger staining of glandular epithelial cells than anestrous and estrous samples. The progesterone-dependent increase in IFNE abundance during the estrous cycle likely implies that IFNE is part of the innate immune system in endometrium that gives protection against uterine infections during progesterone-dominated phase of the estrous cycle.