According to the present paradigm, 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] is a biologically active hormone; whereas 25-hydroxyvitamin D3 (25OHD3) is regarded as a prohormone activated through the action of 25-hydroxyvitamin D3 1alpha-hydroxylase (1alpha-hydroxylase). Although the role of vitamin D3 in the regulation of growth and differentiation of prostatic epithelial cells has been well studied, its action and metabolism in prostatic stroma are still largely unknown. We investigated the effects of 25OHD3 and 1alpha,25-(OH)2D3 on two human stromal primary cultures termed P29SN and P32S. In a cell proliferation assay, 25OHD3 was found at physiological concentrations of 100-250 nM to inhibit the growth of both primary cultures, whereas 1alpha,25-(OH)2D3 at a pharmacological concentration of 10 nM exhibited the growth-inhibitory effects on P29SN cells but not on P32S cells. Quantitative real-time RT-PCR analysis revealed that both 25OHD3 and 1alpha,25-(OH)2D3 induced 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) mRNA in a dose- and time-dependent manner. By inhibiting 1alpha-hydroxylase and/or 24-hydroxylase enzyme activities, the induction of 24-hydroxylase mRNA by 250 nM 25OHD3 was clearly enhanced, suggesting that 1alpha-hydroxylation is not a prerequisite for the hormonal activity of 25OHD3. Altogether our results suggest that 25OHD3 at a high but physiological concentration acts as an active hormone with respect to vitamin D3 responsive gene regulation and suppression of cell proliferation.
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Cardiovasc Toxicol
January 2025
Department of Physiology, Pharmacology and Toxicology, West Virginia University School of Medicine, Morgantown, WV, USA.
Pregnancy is a vulnerable time with significant cardiovascular changes that can lead to adverse outcomes, which can extend into the postpartum window. Exposure to emissions from electronic cigarettes (Ecig), commonly known as "vaping," has an adverse impact on cardiovascular function during pregnancy and post-natal life of offspring, but the postpartum effects on maternal health are poorly understood. We used a Sprague Dawley rat model, where pregnant dams are exposed to Ecigs between gestational day (GD)2-GD21 to examine postpartum consequences.
View Article and Find Full Text PDFVet Res Commun
January 2025
Biochemistry, Veterinary Biosciences Department, Veterinary Faculty, Universidad de la República, Ruta 8, Km 18 y Ruta 102, Montevideo, 13000, Uruguay.
The aim was to study the effect of long-acting analogue of oxytocin (Carbetocin) on cervical collagenolysis of MAP-eCG synchronized ewes. At the expected time of artificial insemination, five ewes were slaughtered (n = 5) and their cervical explants (100-200 mg) were incubated during 12 h with MEM supplemented with 0, 8, 16, 32 and 64 ng/mL of Cb. Activities of activated and latent forms of matrix metalloproteinases-2 and - 9 (MMP-2 and MMP-9, respectively) in the supernatant were determined by a SDS-PAGE zymography and prostaglandin E2 concentration by immunoassay.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
January 2025
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
Identifying hormone-like quorum sensing (QS) molecules in streptomycetes is challenging due to low production levels but is essential for understanding secondary metabolite biosynthesis and morphological differentiation. This work reports the discovery of a novel γ-butenolide-type signaling molecule (SFB1) via overexpressing its biosynthetic gene (orf18) in Streptomyces fradiae. SFB1 was found to be essential for production of tylosin through dissociating the binding of its receptor TylP (a transcriptional repressor) to target genes, thus activating the expression of tylosin biosynthetic gene cluster (tyl).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Gene Expression Laboratory, Salk Institute, La Jolla, CA 92037-1002.
Nutritional status is a determining factor for growth during development and homeostatic maintenance in adulthood. In the context of muscle, growth hormone (GH) coordinates growth with nutritional status; however, the detailed mechanisms remain to be fully elucidated. Here, we show that the transcriptional repressor B cell lymphoma 6 (BCL6) maintains muscle mass by sustaining GH action.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
HHMI, The University of Texas at Austin, Austin, TX 78712.
Dynamic control of signaling events requires swift regulation of receptors at an active state. By focusing on the Arabidopsis ERECTA (ER) receptor kinase, which perceives peptide ligands to control multiple developmental processes, we report a mechanism preventing inappropriate receptor activity. The ER C-terminal tail (ER_CT) functions as an autoinhibitory domain: Its removal confers higher kinase activity and hyperactivity during inflorescence and stomatal development.
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