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Brucellosis is still a widespread zoonotic disease. Very little is known about the interaction betweenBrucella abortus and trophoblastic cells, which is essential for better understanding the pathogenesis of the Brucella-induced placentitis and abortion, a key event for transmission of the disease. The goal of this study was to evaluate the profile of gene expression by bovine trophoblastic cells during infection with B. abortus. Explants of chorioallantoic membranes were inoculated with B. abortus strain 2308. Microarray analysis was performed at 4 h after infection, and expression of cytokines and chemokines by trophoblastic cells was assessed by real-time reverse transcription-PCR at 6 and 12 h after inoculation. In addition, cytokine and chemokine expression in placentomes from experimentally infected cows was evaluated. Expression of proinflammatory genes by trophoblastic cells was suppressed at 4 h after inoculation, whereas a significant upregulation of CXC chemokines, namely, CXCL6 (GCP-2) and CXCL8 (interleukin 8), was observed at 12 but not at 6 h after inoculation. Placentomes of experimentally infected cows had a similar profile of chemokine expression, with upregulation of CXCL6 and CXCL8. Our data indicate that B. abortus modulates the innate immune response by trophoblastic cells, suppressing the expression of proinflammatory mediators during the early stages of infection that is followed by a delayed and mild expression of proinflammatory chemokines, which is similar to the profile of chemokine expression in the placentomes of experimentally infected cows. This trophoblastic response is likely to contribute to the pathogenesis of B. abortus-induced placentitis.Brucella abortus is a facultative intracellular gram-negative bacterium that causes abortion and temporary infertility in cattle (13,19,29). It is also a zoonotic pathogen causing fever, weakness, endocarditis, arthritis, osteomyelitis, and meningitis in humans (51). In cattle, the infection tends to be chronic with tropism for the reproductive system of pregnant cows. Abortion is the most significant clinical sign, but an infected cow may be completely asymptomatic. Transmission of the disease occurs mainly after abortion or parturition of infected cows via contaminated fetus, fetal membranes, and uterine secretions (8,37,38). During the early stages of infection, B. abortus is found mostly in lymph nodes. The infection may progress to bacteremia and colonization of the uterus, where the organism replicates preferentially within trophoblasts in the rough endoplasmic reticulum (9, 10, 29). As a result, the cow develops placentitis, fetal death, and abortion, particularly during the last third of the gestation (2). B. abortus grows primarily in the extracotyledonary trophoblasts and then spreads to the cotyledonary (placental) trophoblasts (3). Therefore, proliferation of B. abortus within trophoblastic cells is a key event in the mechanism of abortion. Trophoblasts favor bacterial growth by producing erythritol and progesterone, which stimu...

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Abstract:Bidens pilosa L. is a cosmopolitan annual herb, known for its traditional use in treating various diseases and thus much studied for the biological activity of its extracts, fractions and isolated compounds. Polyacetylenes and flavonoids, typical metabolite classes in the Bidens genus, predominate in the phytochemistry of B. pilosa. These classes of compounds have great taxonomic significance. In the Asteraceae family, the acetylene moiety is widely distributed in the Heliantheae tribe and some representatives, such as 1-phenylhepta-1,3,5-triyne, are noted for their biological activity and strong long-wave UV radiation absorbance. The flavonoids, specifically aurones and chalcones, have been reported as good sub-tribal level markers. Natural products from several other classes have also been isolated from different parts of B. pilosa. This review summarizes the available information on the 198 natural products isolated to date from B. pilosa.