2005 Fiscal Year Final Research Report Summary
Identification and suppression of specific genes of urinary incontinence using RNAi
| Project/Area Number |
16390461
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Urology
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| Research Institution | University of Fukui |
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Principal Investigator |
YOKOYAMA Osamu University of Fukui, Urology, Professor, 医学部, 教授 (90242552)
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| Co-Investigator(Kenkyū-buntansha) |
AKINO Hironobu University of Fukui, Urology, Associate Professor, 医学部, 助教授 (90159335)
SHIOYAMA Rikiya University of Fukui, Urology, Lecturer, 医学部, 助手 (60345676)
SATO Makoto University of Fukui, Cell Biology and Neuroscience, Professor, 医学部, 教授 (10222019)
NAKAI Masaharu University of Fukui, Urology, Lecturer, 医学部, 助手 (50372496)
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| Project Period (FY) |
2004 – 2005
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| Keywords | overactive bladder / urinary incontinence / gene / cerebral infarction / COX-2 / prostaglandin / PGES / pons |
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| Research Abstract |
Development of bladder overactivity (BO) caused by cerebral infarction (CI) is believed to require RNA transcription in the pontine micturition center (PMC). We previously reported that the expression of cyclooxygenase-2 (COX-2) mRNA was mediated by the activity of an NMDA (N-methyl-D-aspartate) receptor in the PMC and necessary for the development of BO. This study was undertaken to examine whether the expression of prostaglandin (PG) E or D synthase, downstream gene of COX-2, and levels of PGE2 and D were related to BO. To begin with, background mouse (C57-BL/6J) of COX-2 knockout was used to examine whether it has the same response to CI as a rat model. To confirm that the expression of COX-2 is essential for the development of BO, in vivo RNAi in the mice PMC and left middle cerebral artery (MCA) occlusion are thought to be necessary.
Methods : Cerebral infarction (CI) was induced by MCA occlusion in female SD rats and C57-BL/6J mice. Awake animals were cystometrically examined. Spe
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cimens were obtained from the dorsal pontine tegmentum (DPT) 0.25, 1, 3, 5, 12, and 24 hours after MCA occlusion or a sham operation (SO). Expressions of PGES and PGDS in the DPT were monitored with real-time PCR. To determine whether PGE2 is essential for the induction of BO, microinjection of PGE2 into the PMC or periaquaeductal gray (PAG) was performed in urethane anesthetized rats. Furthermore, ONO-8711, EP1 receptor antagonist was administered intravenously or intracerebroventriculaly before PGE2 instillation.
Results : Bladder capacity of CI rats and mice was significantly reduced 1-24 hours after MCA occlusion. One hour after MCA occlusion, PGES and PGDS mRNA expression had significantly increased, as compared to that in SO animals. PGES expressions remained consistently higher than those in SO rats at least 12 hours after MCA occlusion. Pretreatment with MK-801 inhibited the development of bladder overactivity and significantly reduced the expression of PGES mRNA in the DPT. The level of PGE2 increased 3 to 5 hours after MCA occlusion at the DPT. Microinjection of PGE2 into the cerebral ventricle and dorsal pontine tegmentum increased bladder capacity. PGE2 into the PAG significantly decreased bladder capacity, which was antagonized by the administration of ONO-8711. MCA occlusion produced a significant reduction in bladder capacity and increased expression of COX-2/PGES in the DPT of C57-BL/6J mice.
Conclusion : These results indicate that the development of BO following MCA occlusion is mediated by an increase in COX-2 and PGES mRNA expression in the DPT. Increase in PGE2 level in the PAG is believed to play an important role in the development of BO caused by CI. Less
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