👤 V Ouellet

The maternal environment during gestation influences fetal development, with long-lasting effects on postnatal health and productivity. This study evaluated the effect of prenatal heat stress (PNHS) on blood DNA methylation of dairy calves immediately after birth and whether such modifications persist into early life. Holstein calves were born to dams exposed to either PNHS (n = 36, temperature-humidity index >68, access to shade of a freestall barn) or prenatal cooling (PNTN; n = 37, access to shade and evaporative cooling) during the last 54 ± 5 d of gestation. Whole-genome enzymatic DNA methyl sequencing was performed on blood samples collected at birth (d 0; n = 3 PNHS, n = 5 PNTN) and 1 wk post-weaning (d 63 of age; n = 8 PNHS, n = 8 PNTN). From birth onward, all calves were actively cooled and managed under the same conditions. At birth, 682,898 differentially methylated cytosines (DMC) were identified genome-wide. Principal component analysis using 55,304 DMC located in genes expressed in blood cells revealed a clear clustering by prenatal treatment. However, at weaning, clear clustering by treatment was no longer observed using 23,977 treatment-associated DMC in blood-expressed genes, despite 97,289 DMC persisting genome-wide from birth to weaning. Immune cell deconvolution showed only minor differences in granulocytes (d 0) and CD4/CD8 Show less

Estrogens are well recognized to have beneficial effects on vulvovaginal atrophy because of menopause. The distribution of estrogen receptors and enzymes responsible for estradiol (E2) formation within the vagina may provide insight into how dehydroepiandrosterone, a precursor of both estrogens and androgens, improves vulvovaginal atrophy. The purpose of the study was to determine where the steroidogenic enzymes responsible for E2 formation as well as estrogen receptors are localized in vaginal specimens collected from cynomolgus monkeys (Macaca fascicularis), the closest model to the human. HSD3B1, HSD17B1, HSD17B5, HSD17B12, aromatase (CYP19A1), estrogen receptor (ER)-α, and ER-β were measured or localized by quantitative real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence. Estrogens were quantified by liquid chromatography/tandem mass spectrometry. All steroidogenic enzymes and estrogen receptors are localized mainly in the superficial layer of the stratified squamous epithelium, blood vessel walls, and muscle fibers of the vagina. Immunolabeling of HSD17B5 and HSD17B12 shows that these enzymes are uniformly distributed from the basal membrane to the superficial keratinized cells, whereas HSD3B1 and aromatase are particularly localized in the outer (external) portion of the epithelial layer. ER-α and ER-β are also distributed within the vaginal epithelium, with expression especially elevated at the basal membrane level. The enzymes responsible for E2 formation as well as ERs are expressed mainly in the superficial layer of the stratified epithelium as well as the muscle layer of the vagina. The present data provide morphologic and biochemical support for the role of local dehydroepiandrosterone transformation into estrogens in regulating epithelial cell maturation, pH, fluid secretion, smooth muscle activity, and blood flow regulation in the primate vagina. Show less

It is well documented that human breast is actively involved in the local formation of estrogens. To determine the site(s) of action of enzymes involved in synthesis and metabolism of the most potent estrogen estradiol (E2), we have studied the expression of the following enzymes: 3beta-hydroxysteroid dehydrogenase (3-HSD), 17beta-HSD types 1, 2, 5, 7 and 12, aromatase, steroid sulfatase (STS) and estrogen sulfotransferase (EST) 1E1 at the cellular level in breast. Both in situ hybridization and immunocytochemistry were used for enzyme localization in normal breast tissues. For immunocytochemistry, we used rabbit antibodies, while in situ hybridization studies were performed using (35S)-labeled cRNA probes. Similar results were obtained with both approaches. All the enzymes (3beta-HSD; 17beta-HSD types 1, 5, 7 and 12; aromatase) involved in the conversion of circulating dehydroepiandrosterone (DHEA) to E2 as well as STS which converts estradiol sulfate (E2-S) to E2 have been found to be expressed in epithelial cells of acini and/or ducts as well as the stromal cells. Moreover, 17beta-HSD type 2 and EST1E1, two enzymes which inactivate E2, have been also localized in the same cell types. The present results indicate the enzymes which play a role in the synthesis and metabolism of E2 are expressed in both epithelial and stromal cells in human breast. Show less