scholarly journals Cell Type-specific Expression of β-Carotene 9', 10'-Monooxygenase in Human Tissues

2005 ◽  
Vol 53 (11) ◽  
pp. 1403-1412 ◽  
Author(s):  
Annika Lindqvist ◽  
Yu-Guang He ◽  
Stefan Andersson
Keyword(s):  
Small Intestine ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Physiological Role ◽  
Cell Types ◽  
Human Tissues ◽  
Specific Expression ◽  
Β Carotene

The symmetrically cleaving β-carotene 15, 15'-monooxygenase (BCO1) catalyzes the first step in the conversion of provitamin A carotenoids to vitamin A in the mucosa of the small intestine. This enzyme is also expressed in epithelia in a variety of extraintestinal tissues. The newly discovered β-carotene 9', 10'-monooxygenase (BCO2) catalyzes asymmetric cleavage of carotenoids. To gain some insight into the physiological role of BCO2, we determined the expression pattern of BCO2 mRNA and protein in human tissues. By immunohistochemical analysis it was revealed that BCO2 was detected in cell types that are known to express BCO1, such as epithelial cells in the mucosa of small intestine and stomach, parenchymal cells in liver, Leydig and Sertoli cells in testis, kidney tubules, adrenal gland, exocrine pancreas, and retinal pigment epithelium and ciliary body pigment epithelia in the eye. BCO2 was uniquely detected in cardiac and skeletal muscle cells, prostate and endometrial connective tissue, and endocrine pancreas. The finding that the BCO2 enzyme was expressed in some tissues and cell types that are not sensitive to vitamin A deficiency and where no BCO1 has been detected suggests that BCO2 may also be involved in biological processes other than vitamin A synthesis.

scholarly journals Bitot’s Spots following Bariatric Surgery: An Ocular Manifestation of a Systemic Disease

2017 ◽  
Vol 8 (3) ◽  
pp. 581-589 ◽  
Author(s):  
Amanda R. Crum ◽  
Divya Srikumaran ◽  
Fasika Woreta
Keyword(s):  
Bariatric Surgery ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Systemic Disease ◽  
Night Vision ◽  
Nutritional Deficiencies ◽  
Ophthalmic Manifestations ◽  
Number Of Patients

Background: To present a case of ocular complications from vitamin A deficiency following bariatric surgery. Case Report: A 41-year-old woman presented with symptoms of dryness and diminished night vision. Examination revealed corneal punctate staining, keratinization of the conjunctiva, and multiple mid-peripheral white lesions at the level of the retinal pigment epithelium. Given the patient’s history of bariatric surgery, anemia, and vitamin D deficiency, further investigation into micronutrient levels was performed and indicated a severe vitamin A deficiency. Oral vitamin A supplementation resulted in the complete resolution of her symptoms within two months. Conclusions: Nutritional deficiencies following bariatric surgery are common and can be disruptive to normal systemic health and visual function. Given that the number of patients pursuing bariatric surgery for weight loss management has increased over the past 50 years, eye care professionals should be aware of the ophthalmic manifestations associated with micronutrient deficiency.

scholarly journals Nutritional enhancement of Ghanaian weaning foods using the orange flesh sweetpotato (Ipomea batatas)

2014 ◽  
Vol 14 (65) ◽  
pp. 9236-9256
Author(s):  
EA Bonsi ◽  
◽  
WA Plahar ◽  
R Zabawa ◽  
◽  
...  
Keyword(s):  
Vitamin A ◽  
Sweet Potato ◽  
Nutritive Value ◽  
Vitamin A Deficiency ◽  
Consumer Acceptability ◽  
Weaning Food ◽  
Nutrient Density ◽  
Weaning Foods ◽  
Maize Meal ◽  
Β Carotene

Vitamin A deficiency (VAD) is a public health problem in Ghana. Research on the orange flesh sweet potato root has been given prominence because of its high β - carotene content as a means to enhance the nutritive value and vitamin A content of the traditional diets of Ghanaian children as a long -term intervention towards combating VAD. Two Ghanaian cereal -legume weaning foods: roasted maize- soy blend and fermented maize -soy blend were added to Orange Flesh Sweet potato (O FS) flour from the variety, Beauregard, to develop four weaning food formulations . To each product formulation preparation, 25% and 50% OFS flour was added to the basic cereal - legume meals , and mixed thoroughly. The four weaning formulations were evaluated for chemical composition, sensory characteristics and consumer acceptability. All samples had a range of protein (12.1% - 15%), fat (4.8% - 6.4%), carbohydrate (71.1% – 75.1%), energy (380 - 390 kcal/100g) and minerals (calcium, iron and phosphorus) to ensure good nutrient density, while the moisture content was low (5.3% - 6.1%) for storage stability. The contribution of β -carotene ( 55.18 –115.55 ug/g) by the OFS in the formulations further enhanced the nutritive value of all the blends and is enough to meet the daily β -carotene needs of the children ( 1-6 yrs of 400 -450ug/100g). A higher level of β -carotene was seen in the roasted maize meal weaning foods which make s them a better potential blend for combating VAD. Also, sensory evaluation of the products indicated the highest consumer acceptability score (87%) for the roasted maize meal porridge formulation containing 25% OFS . It is, therefore , concluded that OFS flour has the potential to be used at 25% replacement level in the soy- fortified roasted maize meal formulation, and OFS is a useful ingredient with the potential to improve the β -carotene or vitamin A content of such formulations . This will help alleviate vitamin A deficiency of children in Ghana and other countries with similar problems . It is , therefore, recommended that the orange flesh sweet potato flour be used by mothers as an entry point for enhancing the traditional weaning food preparations .

scholarly journals Cassava with enhanced β-carotene maintains adequate vitamin A status in Mongolian gerbils (Meriones unguiculatus) despite substantial cis-isomer content

2009 ◽  
Vol 102 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Julie A. Howe ◽  
Bussie Maziya-Dixon ◽  
Sherry A. Tanumihardjo
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Meriones Unguiculatus ◽  
Provitamin A ◽  
Carotenoid Content ◽  
Mongolian Gerbils ◽  
Serum Retinol ◽  
Vitamin A Status ◽  
Isomer Content ◽  
Β Carotene

Efforts to increase β-carotene in cassava have been successful, but the ability of high-β-carotene cassava to prevent vitamin A deficiency has not been determined. Two studies investigated the bioefficacy of provitamin A in cassava and compared the effects of carotenoid content and variety on vitamin A status in vitamin A-depleted Mongolian gerbils (Meriones unguiculatus). Gerbils were fed a vitamin A-free diet 4 weeks prior to treatment. In Expt 1, treatments (ten gerbils per group) included 45 % high-β-carotene cassava, β-carotene and vitamin A supplements (intake matched to high-β-carotene cassava group), and oil control. In Expt 2, gerbils were fed cassava feeds with 1·8 or 4·3 nmol provitamin A/g prepared with two varieties. Gerbils were killed after 4 weeks. For Expt 1, liver vitamin A was higher (P < 0·05) in the vitamin A (1·45 (sd 0·23) μmol/liver), lower in the control (0·43 (sd 0·10) μmol/liver), but did not differ from the β-carotene group (0·77 (sd 0·12) μmol/liver) when compared with the high-β-carotene cassava group (0·69 (sd 0·20) μmol/liver). The bioconversion factor was 3·7 μg β-carotene to 1 μg retinol (2 mol:1 mol), despite 48 % cis-β-carotene [(Z)-β-carotene] composition in cassava. In Expt 2, cassava feed with 4·3 nmol provitamin A/g maintained vitamin A status. No effect of cassava variety was observed. Serum retinol concentrations did not differ. β-Carotene was detected in livers of gerbils receiving cassava and supplements, but the cis-to-trans ratio in liver differed from intake. Biofortified cassava adequately maintained vitamin A status and was as efficacious as β-carotene supplementation in the gerbil model.

Degradation of extracellular ATP by the retinal pigment epithelium

2005 ◽  
Vol 289 (3) ◽  
pp. C617-C624 ◽  
Author(s):  
David Reigada ◽  
Wennan Lu ◽  
Xiulan Zhang ◽  
Constantin Friedman ◽  
Klara Pendrak ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Adenosine Diphosphate ◽  
Cell Types ◽  
P2y Receptors ◽  
Extracellular Atp ◽  
Pcr Analysis ◽  
Subretinal Space ◽  
Rpe Cells ◽  
Mrs 2179

Stimulation of ATP or adenosine receptors causes important physiological changes in retinal pigment epithelial (RPE) cells that may influence their relationship to the adjacent photoreceptors. While RPE cells have been shown to release ATP, the regulation of extracellular ATP levels and the production of dephosphorylated purines is not clear. This study examined the degradation of ATP by RPE cells and the physiological effects of the adenosine diphosphate (ADP) that result. ATP was readily broken down by both cultured human ARPE-19 cells and the apical membrane of fresh bovine RPE cells. The compounds ARL67156 and βγ-mATP inhibited this degradation in both cell types. RT-PCR analysis of ARPE-19 cells found mRNA message for multiple extracellular degradative enzymes; ectonucleotide pyrophosphatase/phosphodiesterase eNPP1, eNPP2, and eNPP3; the ectoATPase ectonucleoside triphosphate diphosphohydrolase NTPDase2, NTPDase3, and some message for NTPDase1. Considerable levels of ADP bathed RPE cells, consistent with a role for NTPDase2. ADP and ATP increased levels of intracellular Ca2+. Both responses were inhibited by thapsigargin and P2Y1 receptor inhibitor MRS 2179. Message for both P2Y1 and P2Y12 receptors was detected in ARPE-19 cells. These results suggest that extracellular degradation of ATP in subretinal space can result in the production of ADP. This ADP can stimulate P2Y receptors and augment Ca2+ signaling in the RPE.

Selective utilization of serum vitamin A for visual pigment synthesis

1989 ◽  
Vol 142 (1) ◽  
pp. 207-214
Author(s):  
A. T. Tsin ◽  
S. N. Gentles ◽  
E. A. Castillo
Keyword(s):  
Vitamin A ◽  
Visual Pigment ◽  
Carassius Auratus ◽  
High Performance ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Serum Vitamin ◽  
Pigment Synthesis ◽  
Goldfish Carassius Auratus ◽  
Vitamin A2

Two groups of goldfish (Carassius auratus) were subjected to light and temperature conditions known to promote a contrast in their scotopic visual pigment compositions. After 3 weeks, the porphyropsin/rhodopsin ratio in the neuroretina of these goldfish ranged from 99% porphyropsin in one group to 59% in the other. Samples of blood, liver and retinal pigment epithelium (RPE) were also removed from these animals and analysed by high-performance liquid chromatography (HPLC) for vitamin A composition. There was consistently more vitamin A2 than vitamin A1 (over 50% vitamin A2) in both vitamin A alcohol and vitamin A esters extracted from the liver and the RPE. In contrast, only 30% of all vitamin A extracted from the blood was vitamin A2. These observations suggest that it is mainly vitamin A1 that is transported in the blood, whereas vitamin A2 is selectively retained in the liver and in the RPE and used to form porphyropsin in the eye.

scholarly journals Effect of Drying on β-Carotene, α Carotene, Lutein and Zeaxanthin Content in Vegetables and Its Application for Vegetable Seasoning

2020 ◽  
Vol 141 ◽  
pp. 02007
Author(s):  
Kullamethee Piyarach ◽  
Kamnerd Nipawan ◽  
Chumphukhaw Chadapon ◽  
Suwannasit Daluwan ◽  
Rotjanapun Kunjana
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Cost Effective ◽  
Food Preservation ◽  
Daily Consumption ◽  
Overall Acceptability ◽  
Chinese Kale ◽  
Pepper Powder ◽  
Air Dryer ◽  
Β Carotene

In plant based food with dark-green, yellow and orange color, beta (β)-carotene, alpha (α)-carotene, lutein and zeaxanthin are predominating carotenoids contributing to an eyesight improvement. Among food preservation methods, drying using cabinet hot air dryer is one of the most cost-effective options and therefore, this investigation was aimed to study the carotenoids content in vegetables after drying and optimize the vegetable seasoning product. Based on customer survey, carrot, pumpkin, Chinese kale and long coriander were selected for the experiment, accessibility and have met the requirement of final moisture content, less than 10%. Our results demonstrated that drying period of sliced carrots and pumpkins was 360 min, while in Chinese kale and long coriander was 240 min. Amounts of carotenoids in carrot and long coriander were greatly remaining after drying. Drying of Chinese kale had little effect on carotenoids content. While, dried pumpkin may cause a major loss of β-,α-carotene and lutein content over 50%. Regarding to development of vegetable seasoning powder, Just about right and Hedonic 9 point tests were used for a sensory evaluation. The optimal seasoning formula consisted of 66. 8% mixed dried ground vegetables, 13.4% sugar, 8.8% salt, 6.7% garlic powder, and 4.3% white pepper powder. The overall acceptability of the product was rated as moderately liked, containing β-carotene, α-carotene, lutein and zeaxanthin content as 178.04±3.39, 58.81±1.83, 158.89±4.16, 0.98±0.01 μg/g, respectively (vitamin A approximately 29.67 μg RE/g). Fortification of vegetable seasoning powder for daily consumption may improve the eye vision and reduce the rate of vitamin A deficiency.

scholarly journals Peropsin modulates transit of vitamin A from retina to retinal pigment epithelium

2017 ◽  
Vol 292 (52) ◽  
pp. 21407-21416 ◽  
Author(s):  
Jeremy D. Cook ◽  
Sze Yin Ng ◽  
Marcia Lloyd ◽  
Shannan Eddington ◽  
Hui Sun ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Vitamin A ◽  
Pigment Epithelium ◽  
Retinal Pigment

scholarly journals CMO1 Deficiency Abolishes Vitamin A Production from β-Carotene and Alters Lipid Metabolism in Mice

2007 ◽  
Vol 282 (46) ◽  
pp. 33553-33561 ◽  
Author(s):  
Susanne Hessel ◽  
Anne Eichinger ◽  
Andrea Isken ◽  
Jaume Amengual ◽  
Silke Hunzelmann ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Elevated Serum ◽  
Pcr Analysis ◽  
Marker Genes ◽  
Mouse Mutant ◽  
Adipose Tissues ◽  
Β Carotene

Carotenoids are currently investigated regarding their potential to lower the risk of chronic disease and to combat vitamin A deficiency in humans. These plant-derived compounds must be cleaved and metabolically converted by intrinsic carotenoid oxygenases to support the panoply of vitamin A-dependent physiological processes. Two different carotenoid-cleaving enzymes were identified in mammals, the classical carotenoid-15,15′-oxygenase (CMO1) and a putative carotenoid-9′,10′-oxygenase (CMO2). To analyze the role of CMO1 in mammalian physiology, here we disrupted the corresponding gene by targeted homologous recombination in mice. On a diet providing β-carotene as major vitamin A precursor, vitamin A levels fell dramatically in several tissues examined. Instead, this mouse mutant accumulated the provitamin in large quantities (e.g. as seen by an orange coloring of adipose tissues). Besides impairments in β-carotene metabolism, CMO1 deficiency more generally interfered with lipid homeostasis. Even on a vitamin A-sufficient chow, CMO1-/- mice developed a fatty liver and displayed altered serum lipid levels with elevated serum unesterified fatty acids. Additionally, this mouse mutant was more susceptible to high fat diet-induced impairments in fatty acid metabolism. Quantitative reverse transcription-PCR analysis revealed that the expression of peroxisome proliferator-activated receptor γ-regulated marker genes related to adipogenesis was elevated in visceral adipose tissues. Thus, our study identifies CMO1 as the key enzyme for vitamin A production and provides evidence for a role of carotenoids as more general regulators of lipid metabolism.

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