The chemokine receptor CXCR4 and its ligand CXCL12 are activated during implantation and placentation in sheep

<p>Abstract</p> <p>Background</p> <p>The progression of implantation and placentation in ruminants is complex and is regulated by interplay between sex steroids and local signaling molecules, many of which have immune function. Chemokines and their receptors are pivotal factors in implantation and vascularization of the placenta. Based on known critical roles for chemokine receptor 4 (CXCR4) during early pregnancy in other species, we hypothesized that CXCR4 and its ligand CXCL12 would increase in the endometrium and conceptus in response to implantation in ewes. The objectives of the current study were to determine if CXCL12 and CXCR4 were upregulated in: endometrium from pregnant compared to non-pregnant ewes and in, conceptuses, cotyledons, caruncles and intercaruncular tissue.</p> <p>Methods</p> <p>Tissues were collected from sheep on Days 12, 13, 14, and 15 of either the estrous cycle or pregnancy and from pregnant ewes on Days 35 and 50. Blood samples from jugular and uterine vein were also collected on all days. Conceptuses were collected from mature ewes on Days 13, 15, 16, 17, 21 and 30 of gestation. Real time PCR was used to determine relative mRNA concentrations for CXCL12 and CXCR4 and Western blot analysis was employed to confirm protein concentration.</p> <p>Results</p> <p>Differences described are P < 0.05. In the endometrium, CXCR4 mRNA and protein was greater on Day 15 of pregnancy compared to the estrous cycle. CXCL12 and CXCR4 mRNA in conceptuses was greater on Days 21 and 30 compared to earlier days. CXCL12 mRNA was greater in cotyledons on Day 35 compared to Day 50. On Day 35 of gestation, CXCR4 was greater compared to Day 50 in caruncle and intercaruncular tissue. White blood cells obtained from jugular and uterine vein collection had the greatest mRNA concentration of CXCL12 on Day 35 of pregnancy.</p> <p>Conclusions</p> <p>A comprehensive analysis of CXCL12 and CXCR4 expression in fetal and maternal tissues during early pregnancy is reported with noteworthy differences occurring during implantation and placentation in sheep. We interpreted these data to mean that the CXCL12/CXCR4 pathway is activated during implantation and placentation in sheep and is likely playing a role in the communication between trophoblast cells and the maternal endometrium.</p

Intratesticular hypertonic sodium chloride solution treatment as a method of chemical castration in cattle

AbstractCastration of male calves is necessary for trading to facilitate handling and prevent reproduction. However, some methods of castration are traumatic and lead to economic losses because of infection and myiasis. The objective of the present study was to evaluate the efficiency of intratesticular injection (ITI) of hypertonic sodium chloride (NaCl; 20%) solution in male calf castration during the first weeks of life. Forty male calves were allocated to one of the following experimental groups: negative control—surgically castrated immediately after birth; positive control —intact males; G1—ITI from 1- to 5-day old; G2—ITI from 15- to 20-day old; and G3—ITI from 25- to 30-day old. Intratesticular injection induced coagulative necrosis of Leydig cells and seminiferous tubules leading to extensive fibrosis. Testosterone secretion and testicular development were severely impaired in 12-month-old animals from G1 and G2 groups (P < 0.05), in which no testicular structure and sperm cells were observed during breeding soundness evaluation. Rectal and scrotal temperatures were not affected by different procedures. In conclusion, ITI of hypertonic NaCl solution induces sterility and completely suppresses testosterone secretion when performed during the first 20 days of life

Neuro-invasion by a 'Trojan Horse' strategy and vasculopathy during intrauterine flavivirus infection

The central nervous system (CNS) is a major target of several important human and animal viral pathogens causing congenital infections. However, despite the importance of neuropathological outcomes, for humans in particular, the pathogenesis, including mode of neuro-invasion, remains unresolved for most congenital virus infections. Using a natural model of congenital infection with an RNA virus, bovine viral diarrhoea virus in pregnant cattle, we sought to delineate the timing and mode of virus neuro-invasion of and spread within the brain of foetuses following experimental respiratory tract infection of the dams at day 75 of pregnancy, a time of maximal risk of tissue pathology without foetal death. Virus antigen was first detected in the foetal brains 14 days postinfection of dams and was initially restricted to amoeboid microglial cells in the periventricular germinal layer. The appearance of these cells was preceded by or concurrent with vasculopathy in the same region. While the affected microvessels were negative for virus antigen, they expressed high levels of the type I interferon-stimulated protein ISG15 and eventually disappeared in parallel with the appearance of microcavitary lesions. Subsequently, the virus spread to neurons and other glial cells. Our findings suggest that the virus enters the CNS via infected microglial precursors, the amoeboid microglial cells, in a Trojan horse mode of invasion and that the microcavitary lesions are associated with loss of periventricular microvasculature, perhaps as a consequence of high, unrestricted induction of interferon-regulated proteins

Development of fetal and placental innate immune responses during establishment of persistent infection with bovine viral diarrhea virus

Transplacental viral infections are dependent upon complex interactions between feto-placental and maternal immune responses and the stage of fetal development at which the infection occurs. Bovine viral diarrhea virus (BVDV) has the ability to cross the placenta and infect the fetus. Infection early in gestation with non-cytopathic (ncp) BVDV leads to persistent infection. Establishment of fetal persistent infection results in life-long viremia, virus-specific immunotolerance, and may have detrimental developmental consequences. We have previously shown that heifers infected experimentally with ncp BVDV type 2 on d. 75 of gestation had transient robust up-regulation of the type I interferon (IFN) stimulated genes (ISGs) 3-15 days after viral inoculation. Blood from persistently infected (PI) fetuses, collected 115 days post maternal infection, demonstrated moderate chronic up-regulation of ISGs. This infection model was used to delineate timing of the development of innate immune responses in the fetus and placenta during establishment of persistent infection. It was hypothesized that: (i) chronic stimulation of innate immune responses occurs following infection of the fetus and (ii) placental production of the type I IFN contributes to up-regulation of ISGs in PI fetuses. PI fetuses, generated by intranasal inoculation of pregnant heifers with ncp BVDV, and control fetuses from uninfected heifers, were collected via Cesarean sections on d. 82, 89, 97, 192, and 245 of gestation. Fetal viremia was confirmed starting on d. 89. Significant up-regulation of mRNA encoding cytosolic dsRNA sensors - RIG-I and MDA5 - was detected on d. 82-192. Detection of viral dsRNA by cytosolic sensors leads to the stimulation of ISGs, which was reflected in significant up-regulation of ISG15 mRNA in fetal blood on d. 89, 97, and 192. No difference in IFN-α and IFN-β mRNA concentration was found in fetal blood or caruncular tissue, while a significant increase in both IFN-α and IFN-β mRNA was seen in cotyledons from PI fetuses on d. 192. It is concluded that fetuses respond to early gestational ncp BVDV infection by induction of the type I IFN pathway, resulting in chronic up-regulation of ISGs. Cotyledonary tissue contributes to up-regulation of ISGs by increased production of IFNs. The innate immune response might partially curtail viral replication in PI fetuses, but is not able to eliminate the virus in the absence of a virus-specific adaptive immune response