Transforming growth factor beta family expression at the bovine feto-maternal interface.

BACKGROUND: Endometrial remodelling is necessary for implantation in all mammalian species. The TGF beta super-family plays a crucial role in this event in humans and mice. However, the role of TGF beta super-family members during implantation is still unclear in ruminants. In the present study, the spacio-temporal expression of TGF beta super-family members including activin was explored in bovine trophoblasts and endometrial tissue during the peri-implantation period in order to elucidate whether it is essential for promoting cell proliferation at the implantation site. METHODS: Gene expression in the fetal membrane and endometrium of the gravid and non-gravid horn around Day 35 of gestation were analyzed with a custom-made oligo-microarray in cattle. The expression of activin and its related genes was also analyzed with quantitative RT-PCR. Activin-like activity in trophoblastic tissue and BT-1 cells was examined using a fibroblast cell proliferation test and Western blotting. RESULTS: The expression of various TGF beta super-family related genes including activin was detected in trophoblasts and the endometrium in cattle. The most intensive activin expression was found in the gravid horn endometrium, and rather intense expression was detected in the non-gravid trophoblastic tissue. Extracts from the fetal membrane including trophoblasts and purified activin both stimulated fibroblast proliferation effectively, and activin was immunologically detected in BT-1 cells, which have trophoblastic features. CONCLUSIONS: Specific expression of the activin gene (gene name: inhibin beta A) was found in the gravid horn endometrium during peri-implantation. An activin-like molecule, which was derived from the endometrium and trophoblasts, stimulated the proliferation of fibroblast cells. These results suggested that as in other species, the activity of TGF beta super-family members including activin-like molecules plays a pivotal role in endometrial remodelling, which is an essential process in implantation and placentogenesis during the peri-implantation period in cattle.

Microwave sterilization of growth medium alleviates inhibition of Aggregatibacter actinomycetemcomitans by Maillard reaction products.

Aggregatibacter (Actinobacillus) actinomycetemcomitans is the causative agent of localized aggressive periodontitis and endocarditis. The bacteria grow slowly even in a rich medium and rapidly lose viability after about 19 h of growth. One of the reasons for the slow growth and for the decreased viability is the conventional method of making growth media by autoclaving. Faster growth and greater viability were observed in both broth and plates if the growth media were sterilized by microwave radiation rather than by autoclaving. One difference between autoclaved and microwaved media is that the autoclaved media are darker brown in color, which is known to be due to the Maillard reaction products, also known as Amadori products. The Maillard reaction products formed by autoclaving a mixture of lysine and glucose were shown to inhibit growth of A. actinomycetemcomitans.