Disease relevance of BCMO1

• Biochemical analysis of baculovirus expressed human BCDO demonstrates the predicted beta,beta-carotene-15,15'-dioxygenase activity [1].
• In addition, the finding that many of the enzymes involved in retinoid metabolism are mutated in retinal degenerations suggests that BCDO may also be a candidate gene for retinal degenerative disease [1].
• In the 10-min BCO global ischemia model, there was also an increase in each of the measured eicosanoids, except LTB4, at 5 min after reperfusion [2].
• This study investigates the effects of tempol, a small, water-soluble molecule, that crosses biological membranes, on the brain injury caused by bilateral occlusion and reperfusion of both common carotid arteries in the gerbil (BCO) [3].
• METHODS: In 23 critically ill patients, 369 paired measurements of CCO and BCO were compared (range of cardiac outputs: 2.8 to 16 L/min) [4].

Psychiatry related information on BCMO1

• METHODS: Under ether anesthesia, gerbils with sham operation (S group, n = 8) and those with pretreatment consisting of BCO for 2 minutes, twice at 3 days and 2 days earlier (T group, n = 8), were again subjected to BCO for 5 minutes [5].

High impact information on BCMO1

• Previous studies have shown that beta-carotene 15,15'-monooxygenase catalyzes the cleavage of beta-carotene at the central carbon 15,15'-double bond but cleaves lycopene with much lower activity [6].
• Beta-carotene 15,15'-monooxygenase (BCO), formerly known as beta-carotene 15,15'-dioxygenase, catalyzes the first step in the synthesis of vitamin A from dietary carotenoids [7].
• High levels of BCO mRNA were observed along the whole intestinal tract, in the liver, and in the kidney, whereas lower levels were present in the prostate, testis, ovary, and skeletal muscle [7].
• The recent demonstration that the responsible beta-carotene cleaving enzyme beta,beta-carotene 15,15'-monooxygenase (Bcmo1) is also present in other tissues led to numerous investigations on the molecular structure and function of this enzyme in several species, including the fruit fly, chicken, mouse, and also human [8].
• BACKGROUND AND PURPOSE: To explore the physiological mechanism of ischemic tolerance, we studied intracerebral oxygenation states noninvasively using near-infrared spectroscopy after bilateral common carotid artery occlusion (BCO) in gerbils with and without ischemic pretreatment [5].

Biological context of BCMO1

• The aim of this study is to identify potentially human-specific regulatory control mechanisms of BCMO1 gene expression [9].
• A mouse orthologue was also identified, and its predicted amino acid sequence is 83% identical with human BCDO [1].
• Tests for enzymatic activity demonstrated that the mRNA upregulation resulted in enzymatically active BCO protein (7.3 ng all-trans-retinal/h per milligram of protein) [10].
• This study was designed to compare measurements of cardiac output as produced by the partial CO(2) rebreathing (NICO), bolus (BCO), and continuous thermodilution (CCO) methods of monitoring cardiac output [11].
• These values also depend on the specific spacer in the complex and, like the pyridine binding constants, decrease in the order BCO > BCA > BCB for the biscorroles and PCO > PCA > PCB for the porphyrin-corrole complexes [12].

Anatomical context of BCMO1

• RESULTS: We identified and functionally characterized the human BCMO1 promoter sequence and determined the transcriptional regulation of the BCMO1 gene in a BCMO1 expressing human intestinal cell line, TC-7 [9].
• The expression pattern of BCDO suggests that it may provide a local supplement to the retinoids available to photoreceptors, as well as a supplement to the retinoid pools utilized elsewhere in the body [1].
• BCO measurements were taken at the following intervals when hemodynamic stability was achieved: (1) after anesthetic induction; (2) during aortic cross-clamp; (3) at reperfusion of the iliac artery; and, (4) during peritoneal closure [11].
• The symmetrically cleaving beta-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 [13].

Associations of BCMO1 with chemical compounds

• The current data suggest that the human BCO enzyme may, in addition to its well established role in the digestive system, also play a role in peripheral vitamin A synthesis from plasma-borne provitamin A carotenoids [7].
• Application of exogenous retinoic acid downregulated BCO mRNA levels at higher concentrations (1 microM; -96%, P < 0.0005) and upregulated it at a lower concentration (0.01 microM; 399%, P < 0.005) [10].
• CONCLUSIONS: The results suggest that BCO is expressed in the RPE and that beta-carotene can be metabolized into retinol. beta-Carotene cleavage in the RPE may be an alternative pathway that would ensure the retinoid supply of photoreceptor cells [10].
• Novel oligothiophenes surrounded by bicyclo[2.2.2]octene (abbreviated as BCO) frameworks ranging from dimer to hexamer, 1(nT) (n = 2, 3, 4, 6), were prepared, and their structures and electronic properties were investigated [14].
• Hexamer 1(6T) was synthesized by oxidative coupling of terthiophene 12, tris-annelated with BCO units, in 81% yield [14].

Physical interactions of BCMO1

• Electrophoretic mobility shift and supershift assays and transcription factor co-expression in TC-7 cells showed MEF2C and PPARgamma bind to their respective DNA elements and synergistically transactivate BCMO1 expression [9].

Other interactions of BCMO1

• The findings suggest that the interaction between MEF2 and PPAR factors may provide a molecular basis for interspecies differences in the transcriptional regulation of the BCMO1 gene [9].
• We have found that a high fat diet enhanced the beta-carotene dioxygenase activity together with the cellular retinol binding protein type II level in rat intestines [15].

Analytical, diagnostic and therapeutic context of BCMO1

• Western blot analyses revealed the presence of BCO at the protein level in D407 cells [10].
• RESULTS: By RT-PCR, BCO mRNA was detected in D407 cells, bovine RPE, and retina [10].
• The bias between CCO and BCO was relatively small until reperfusion but increased significantly at peritoneal closure [11].
• Molecular cloning of the rat beta-carotene 15,15'-monooxygenase gene and its regulation by retinoic acid [16].

References