The phytoene dehydrogenase gene of Phycomyces : regulation of its expression by blue light and vitamin A

1997 ◽  
Vol 253 (6) ◽  
pp. 734-744 ◽  
Author(s):  
M. J. Ruiz-Hidalgo ◽  
E. P. Benito ◽  
G. Sandmann ◽  
A. P. Eslava
2015 ◽  
Vol 107 (4) ◽  
pp. 1017-1027 ◽  
Author(s):  
Wenjing Guo ◽  
Yuxuan Liu ◽  
Xin Yan ◽  
Mingyi Liu ◽  
Hui Tang ◽  
...  

1998 ◽  
Vol 76 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Pangala V Bhat ◽  
Thomas Bader ◽  
Paul Nettesheim ◽  
Anton M Jetten

Retinoic acid (RA), a metabolite of vitamin A, is known to be a key signaling molecule in regulating epithelial cell differentiation. We recently characterized and cloned a retinal dehydrogenase (RALDH) that catalyzes the oxidation of retinal to RA. In this study, we investigated the effects of retinoids on the level of RALDH mRNA and protein as well as RALDH activity in the trachea and cultured tracheal epithelial cells. Vitamin A deficiency induced squamous metaplasia in the tracheal epithelium and down-regulated RALDH expression. Supplementation of retinol and retinoic acid to vitamin A deficient rats restored the normal mucociliary epithelium and up-regulated the RALDH expression. In rat epithelial cells cultured in vitro, RAinhibited squamous differentiation and promoted mucociliary differentiation. Squamous differentiated cultures (RA-) expressed very low levels of RALDH mRNA, whereas mucociliary differentiated cultures (RA+) expressed high levels of RALDH mRNA. Retinal and retinol were poor inducers of mucociliary differentiation as well as RALDH expression. The RALDH expression paralleled the expression of the mucin-1 gene in mucociliary cultures. These results suggest that the expression of RALDH is dependent on the differentiation state of the airway epithelium.Key words: retinoic acid, retinal dehydrogenase, gene expression, tracheal epithelium.


Planta ◽  
2000 ◽  
Vol 210 (6) ◽  
pp. 938-946 ◽  
Author(s):  
Antonio Velayos ◽  
José L. Blasco ◽  
María I. Alvarez ◽  
Enrique A. Iturriaga ◽  
Arturo P. Eslava

Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).


Author(s):  
J.C.S. Kim ◽  
M.G. Jourden ◽  
E.S. Carlisle

Chronic exposure to nitrogen dioxide in rodents has shown that injury reaches a maximum after 24 hours, and a reparative adaptive phase follows (1). Damage occurring in the terminal bronchioles and proximal portions of the alveolar ducts in rats has been extensively studied by both light and electron microscopy (1).The present study was undertaken to compare the response of lung tissue to intermittent exposure to 10 ppm of nitrogen dioxide gas for 4 hours per week, while the hamsters were on a vitamin A deficient diet. Ultrastructural observations made from lung tissues obtained from non-gas exposed, hypovitaminosis A animals and gas exposed animals fed a regular commercially prepared diet have been compared to elucidate the specific effect of vitamin A on nitrogen dioxide gas exposure. The interaction occurring between vitamin A and nitrogen dioxide gas has not previously been investigated.


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