| Project/Area Number |
07670247
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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 | Okayama University |
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Principal Investigator |
TSUTSUI Ken Okayama University Medical School, Department of Molecular Biology, Associate Professor, 医学部, 助教授 (70108158)
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| Co-Investigator(Kenkyū-buntansha) |
TOHGE Hiroko School of Health Science, Okayama University, Associate Professor
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | ribonucleoprotein / hnRNP / nuclear scaffold / nuclear matrix / SAR / MAR / RNA processing |
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| Research Abstract |
Screening of autoantibodies against hnRNP proteins
Immunoblotting analysis of arbitrarily selected 136 patient sera that are positive for antinuclear antibodies revelaed 7 sera (5.2%) positive for reactivity to SP120. However, none of them were suitable for functional analysis of the protein because of their low specificity and low titer. No strong correlation was noted so far between the occurrence of anti-SP120 and disease categories.
Six sera (4.4%) recognized a 150 kDa protein (p150) and one of them was monospecific with a high titer. Immunofluorescence staining of cultured human cells with this serum showed intranuclear staining of a speckled type reminiscent of anti-RNP antibodies. The protein appears to be associated with the nuclear matrix since essentially the samw staining pattern was observed after treating the cells with DNase I and high salt. It was also shown that a fraction of p150 is bound to the 30S hnRNP particle, suggesting that it is a novel component of the hnRNP com
… More
plex.
Assessment of the autoantibody titer against SP120 in aging mice
The antibody titer against SP120 was estimated by immunoblotting using sera obtained from 3 different age groups of C57BL/6 mice. In young mice (4 weeks), all the sera were either negative for the antibody or with low titer. In the aged group (29 months), however, all samples showed positive reaction and about 30% of them exhibited extremely high titers. The remaining group (17 months) showed intermediate titers. These results clearly demonstrate that SP120 is a major target of autoantibodies produced in the aging process.
Antibodies against SAR (scaffold attachment region)
Sera from patients positive for antinuclear antibodies and from normal subjects were subjected to nitrocellulose filter binding assay with cloned SAR fragments originated from 3 different genes (mouse Igkappa, S.cerevisiae CEN III,and D.melanogaster Fushitarazu). All SARs bound more strongly to patient sera than to normal ones (p<0.001). With respect to the SAR-binding capacity in the patient sera, significance of correlation was evident between different SARs but it was not so against antibody titers for ssDNA and dsDNA or amounts of total IgG.
Purified IgG from patient sera bound strongly to all SERs and the Fushitarazu SAR fragment immobilized on Sepharose retrieved a subset of IgG in the patient sera. From these results we conclude that i) antinuclear antibodies contain a population of IgG molecules which recognizes a higher order DNA structure characteristic of SARs, and ii) the antibodies against SARs are probably different from anti-DNA antibodies that are frequently detected in autoimmune diseases. Less
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