Stimulated mouse ear epidermis in explant culture ?The effect of retinoic acid and hexadecane

1981 ◽  
Vol 270 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Hans Hammar
Keyword(s):  
Retinoic Acid ◽  
Explant Culture ◽  
Mouse Ear

The mechanism of aggrecan release from cartilage differs with tissue origin and the agent used to stimulate catabolism

2002 ◽  
Vol 362 (2) ◽  
pp. 465-472 ◽  
Author(s):  
Robert SZTROLOVICS ◽  
Robert J. WHITE ◽  
Peter J. ROUGHLEY ◽  
John S. MORT
Keyword(s):  
Retinoic Acid ◽  
Matrix Metalloproteinases ◽  
Culture Media ◽  
Explant Culture ◽  
Epiphyseal Cartilage ◽  
Human Cartilage ◽  
Nasal Cartilage ◽  
Tissue Extracts ◽  
Significant Release ◽  
Stimulatory Agent

The mechanisms of aggrecan degradation in adult human articular, adult bovine nasal and fetal bovine epiphyseal cartilage in response to either interleukin-1β (IL-1β) or retinoic acid were compared using an explant culture system. Bovine nasal cartilage cultured with either IL-1β or retinoic acid exhibited significant release of glycosaminoglycan (GAG). For both factors, aggrecan proteolysis occurred predominantly at the ‘aggrecanase’ site, with no evidence for the action of matrix metalloproteinases, and resulted in the appearance of the corresponding G1 fragment in tissue extracts and in culture media. In human cartilage, little effect of IL-1β was seen, but abundant release of GAG occurred in the presence of retinoic acid, with evidence of aggrecanase action. Treatment of fetal epiphyseal cartilage with retinoic acid resulted in significant GAG release, whereas treatment with IL-1β did not. In the retinoic acid-treated tissue, however, no evidence for the cleavage of aggrecan in the interglobular region was apparent. Thus, in the fetal system, agents in addition to aggrecanase and matrix metalloproteinases appear to be active. Taken together, these data demonstrate that the pathways utilized for aggrecan catabolism may vary between different cartilages for a given stimulatory agent, and that, for a given tissue, different factors may elicit aggrecan release via different pathways.

LGL1, a novel branching morphogen in developing kidney, is induced by retinoic acid

2007 ◽  
Vol 293 (4) ◽  
pp. F987-F993 ◽  
Author(s):  
Jacklyn Quinlan ◽  
Feige Kaplan ◽  
Neil Sweezey ◽  
Paul Goodyer
Keyword(s):  
Retinoic Acid ◽  
Fetal Lung ◽  
Branching Morphogenesis ◽  
Explant Culture ◽  
Late Gestation ◽  
Ureteric Bud ◽  
Fetal Kidney ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid

Late-gestation lung protein 1 (LGL1) is a glycoprotein secreted by fetal lung mesenchyme that stimulates branching morphogenesis of the developing lung bud. We show that Lgl1 mRNA and protein are also expressed in mesenchymally derived lineages of fetal kidney. Although Lgl1 expression is stimulated by glucocorticoids in kidney cells, cortisol (10−7 M) actually suppresses ureteric bud branching of fetal kidneys from HoxB7/GFP mice in explant culture. However, early branching morphogenesis in the lung and kidney is stimulated by retinoic acid, and we identified putative retinoic acid response elements in the Lgl1 promoter. All- trans-retinoic acid (10−6 M) stimulated Lgl1 promoter activity and endogenous Lgl1 mRNA expression in vitro. Branching of cultured fetal kidney explants was increased in the presence of all- trans retinoic acid (10−6 M). Heterozygous Lgl1 knockout mice were crossed to HoxB7/GFP mice to visualize the extent of ureteric bud branching at fetal stages. At embryonic (E) days E12.5–E13.0, mutant Lgl1+/− embryos showed a 20% reduction in ureteric bud branching compared with wild-type littermates. We propose a model in which retinoic acid stimulates branching morphogenesis by activating Lgl1 early in development. The prominent effects of glucocorticoids on Lgl1 expression in late lung development suggest a second role for LGL1 in alveolar maturation.

Effects of Retinoic Acid and 1,25-Dihydroxyvitamin D3 on IFN-gamma Secretion by Mononuclear Leukocytes from Nulliparous and Postparturient Dairy Cattle

2000 ◽  
Vol 70 (3) ◽  
pp. 92-101 ◽  
Author(s):  
Burim Ametaj ◽  
Brian Nonnecke ◽  
Ronald Horst ◽  
Donald Beitz
Keyword(s):  
Retinoic Acid ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Dairy Cow ◽  
Pokeweed Mitogen ◽  
Mononuclear Leukocytes ◽  
Combined Effects ◽  
Ifn Gamma ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

Individual and combined effects of several isomers of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on interferon-gamma (IFN-gamma) secretion by blood mononuclear leukocytes (MNL) from nulliparous and postparturient Holstein cattle were evaluated in vitro. In the first experiment, effects on incubation period (24 to 72 hours) and time of supplementation (0 to 32 hours) with all-trans, 9-cis, 13-cis-, and 9,13-dicis-RAs (0 to 100 nM) on IFN-gamma secretion by pokeweed mitogen (PWM)-stimulated (0 and 10 mug/ml) MNL from nulliparous cattle were evaluated. In the second experiment, MNL from postparturient cows (bled at 0, 2, 4, and 16 days postpartum) were stimulated with PWM (0 and 10 mug/ml) in the presence of RA isomers (9-cis- or 9,13-dicis-RA; 0 to 100 nM), 1,25-(OH)2D3 (0 to 100 nM), or with combinations of these metabolites. The results show that individual isomers of RA had no effect on IFN-gamma secretion by PWM-stimulated MNL from nulliparous or postparturient cows. Furthermore 1,25-dihydroxyvitamin D3 inhibited IFN-gamma secretion by MNL from nulliparous and postparturient dairy cows; however, the degree of inhibition was greater when 9-cis- and 9,13-dicis-RA were also present in the cultures. Finally mononuclear leukocytes from postparturient dairy cows produced substantially less IFN-gamma than did MNL from nulliparous cattle. It is concluded that retinoic acids individually did not affect the capacity of leukocytes from dairy cattle to secrete IFN-gamma. This result is in marked contrast to studies in monogastric species indicating that RAs inhibit IFN-gamma secretion by peripheral blood T cells. Inhibition of IFN-gamma secretion by 1,25-(OH)2D3 was potentiated by 9-cis- and 9,13-di-cis-retinoics acids, suggesting that an excess of dietary vitamins A and D may compromise further the naturally immunosuppressed postparturient dairy cow. Additional research is necessary to determine if the combined effects of these metabolites on IFN-gamma secretion represent an increased susceptibility of the dairy cow to infectious diseases during the periparturient period. Lower secretion of IFN-gamma by MNL from postpartutient dairy cows, relative to nulliparous cattle, suggests that recently-calved cows are naturally immunosuppressed.

Accelerated degradation of retinoic acid by activated microglia

2013 ◽  
Vol 46 (06) ◽  
Author(s):  
J Hellmann-Regen ◽  
G Kronenberg ◽  
R Uhlemann ◽  
D Freyer ◽  
M Endres ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Activated Microglia ◽  
Accelerated Degradation
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