| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2004: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
Because Thymic involution is known to be induced in victims of child abuse, we investigated whether some molecular markers involved in the thymic involution are available for diagnosis of child abuse. We examined the possible usefulness of Fyn kinase-mediated signaling may be a candidate for the molecular marker. Fyn kinase is known to be abundantly expressed in the thymus and to play important roles for thymocytic proliferation. We investigated the effect of chronic fasting stress on the thymic weight, CD4/CD8 subpopulation, and TUNEL staining in the thymus. The effects of the stress were compared between Fyn-knockout mice and the wild type. The thymus of the wild type mice showed remarkable loss of thymic cortex with loss of CD4/CD8 subpopulation. The TUNEL-positive apoptotic cells were increased in the thymus of the wild type. On the other hand, such changes could not be detected in the thymus of Fyn-knockout mice. Secondly, we investigated whether Fas, which is important molecule for apoptotic signaling, may be involved in the chronic fasting-induced thymic involution. Fas is well-known to interact with Fyn kinase-mediated signaling. Fas-deficient mice also showed resistance to chronic fasting stress-induced thymic involution. The number of CD4/CD8 positive subpopulation, which is the target for apoptosis, was not reduced in the Fas-deficient mice. Judging from these results, Fas-Fyn kinase-mediated signaling may be involved in the chronic fasting induced thymic involution, and thus the humoral molecule responsible for the signaling may be useful for the diagnosis for abused children. However, most of such molecules like IL-2 are easily degradated during postmortem changes, and the use of such molecule for postmortem diagnosis may be difficult. The diagnosis of abuse during life time may be possible by using blood samples.
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