2000 Fiscal Year Final Research Report Summary
Molecular pathology of chronic granulomatous disease cytochrome b558 heavy chain gene
| Project/Area Number |
11670218
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Experimental pathology
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| Research Institution | Nagasaki University |
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Principal Investigator |
KUMATORI Atsushi Institute of Tropical Medicine Nagasaki University, Assistant Professor., 熱帯医学研究所, 講師 (60244092)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Shoich Institute of Tropical Medicine Nagasaki University, Research Associate., 熱帯医学研究所, 助手 (40253695)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Cytochrome b558 / GATA-1 / Eosinophils / PU.1 / CYBB / gp91phox |
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| Research Abstract |
In our chronic granulomatous disease (CGD) patients, neutrophils, monocytes, and B lymphocytes can not generate superoxide, because of severely deduced amount of cytochrme b558 (CYBB) and its mRNA.In contrast, eosinophils can generate superoxide to normal level. To know the pathological situation, we examined eosinophil-specific positive cis-elements. Functional analysis of various mutant of gp91^<phox> promoters in differentiated eosinophilic cells showed a GATA-binding site at bp-98 works as the cic-element. Electrophoretic mobility shift assay showed both GATA-1 and GATA-2 bound to the site with similar apparent Kds. Ectopically expressed GATA-1 and -2 activate a -105/+12 promoter of the gene individually. Simultaneously expressed GATA-2, however, exerted its inhibitory effect on GATA-1 as if it was dominant-negative. These results suggest that GATA-1 works as a principal activator for the gp91^<pnox> gene expression, and GATA-2 does as negative regulator for the GATA-1 dependent mechanism in eosinophils. Next we examined whether eosinophils can clear the drastic reduction of CYBB mRNA by a single base mutation of the PU.1 binding site at bp-53 (-53PU.1) in CYBB promoter by using the GATA system. After confirming the binding of GATA-1 and PU.1 to each binding site we analyzed function of-98GATA and -53PU.1 in eosinophilic cells, and found that these sites work independently in eosinophilic cells. We also found that GATA-1 and PU.1 individually activate the CYBB promoter. Taken together these results show eosinophils have both GATA and PU.1 systems. Therefore, by using the GATA-1 transcription system eosinophils can keep CYBB expression level beyond minimum to generate normal level of superoxide in the patient's eosinophils in spite of crisis of CYBB expression in all other type of cells by the -53 PU.1 mutation.
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Research Products
(4 results)
