The effect of retinoic acid (RA) on testosterone metabolism was examined in a prostatic cancer cell line of human origin, PC-3. In cells growing as monolayers as well as in cell homogenates RA causes a dose-dependent inhibition of the 5 alpha-reductase activity, thus preventing the conversion of testosterone into its hormonally active metabolite, dihydrotestosterone. Fifty per cent inhibition of the enzyme activity occurred at an RA concentration of 2 x 10(-5)M. The pattern of inhibition was that of a non-competitive inhibitor. However, when incubations were performed in the presence of varying amounts of NADPH, it turned out that RA exerts its effect by competitive inhibition of the cofactor action. Although the severe toxicity of RA precludes its systemic use as a 5 alpha-reductase inhibitory drug in humans, the possible anti-androgenic effect of other, less toxic, retinoids should be investigated.
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http://dx.doi.org/10.1016/0022-4731(87)90405-5 | DOI Listing |
Cell Discov
January 2025
Key Laboratory of Organ Regeneration and Reconstruction, State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Hematopoietic stem and progenitor cells (HSPCs) are critical for the treatment of blood diseases in clinic. However, the limited source of HSPCs severely hinders their clinical application. In the embryo, hematopoietic stem cells (HSCs) arise from hemogenic endothelial (HE) cells lining the major arteries in vivo.
View Article and Find Full Text PDFMech Ageing Dev
January 2025
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; School of Life Sciences, Henan University, Kaifeng, Henan Province, China; Henan Key Laboratory of Synthetic Biology and Biomanufacturing, Henan University, Kaifeng, Henan Province 475004, China. Electronic address:
Background: Alveolar epithelial cells (AECs) are the primary targets of many pathogens and play an important role in sensing viruses and regulating immunity. Yet, little is known about the antiviral responses in the aged AECs.
Methods: The responses of young or aged AECs after viral infection were analyzed using methods such as flow cytometry, quantitative real-time PCR, Western blot detection, and transwell chemotaxis assay.
The prognosis for patients with acute promyelocytic leukemia (APL) has improved dramatically since the introduction of all-trans retinoic acid (ATRA) and intravenous arsenic trioxide (ATO). However, ATO administration requires daily infusions over several months, representing an onerous burden for hospitals and patients. We evaluated the bioavailability of a novel encapsulated oral ATO formulation in APL patients in first complete remission during standard-of-care consolidation.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.
Classical tissue recombination experiments demonstrate that cell-fate determination along the anterior-posterior axis of the Müllerian duct occurs prior to postnatal day 7 in mice. However, little is known about how these cell types are maintained in adults. In this study, we provide genetic evidence that a balance between antagonistic retinoic acid (RA) and estrogen signaling activity is required to maintain simple columnar cell fate in adult uterine epithelium.
View Article and Find Full Text PDFCurr Top Dev Biol
January 2025
Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH, United States.
Alterations in tissue expression levels of both retinol-binding protein 2 (RBP2) and retinol-binding protein 4 (RBP4) have been associated with metabolic disease, specifically with obesity, glucose intolerance and hepatic steatosis. Our laboratories have shown that this involves novel pathways not previously considered as possible linkages between impaired retinoid metabolism and metabolic disease development. We have established both biochemically and structurally that RBP2 binds with very high affinity to very long-chain unsaturated 2-monoacylglycerols like the canonical endocannabinoid 2-arachidonoyl glycerol (2-AG) and other endocannabinoid-like substances.
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