| Project/Area Number |
16591743
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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 |
Ophthalmology
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| Research Institution | Shinshu University |
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Principal Investigator |
KATAI Naomichi Shinshu University, Shinshu University Hospital, Lecturer, 医学部附属病院, 講師 (10260572)
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| Co-Investigator(Kenkyū-buntansha) |
ARAI Jun Shinshu University, Shinshu University Hospital, Assistant, 医学部附属病院, 助手 (70334894)
MIYAHARA Teruyoshi Shinshu University, Shinshu University Hospital, Assistant, 医学部附属病院, 助手 (80362135)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2004: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Retinal ischemia reperfusion / Neuroprotection / Heme oxygenase / siRNA / 網膜虚血再灌流 / ヘムオキシダーゼ |
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| Research Abstract |
Purpose.
To investigate the neuroprotective roles of heme oxygenase-1 (HO-1) and HO-2 in the retina following ischemia-reperfusion injury.
Methods.
Retinal ischemia was induced in SD rats by increasing the intraocular pressure to 110 mHg for 45 or 60 minutes. The expression of HO-1 and HO-2 in the retina was determined by Western blot, real-time polymerase chain reaction (PCR), and immunohistochemistry. To inhibit the up-regulation of HO-1, short interfering RNA (siRNA) of HO-1 or of green fluorescent protein (GFP) was injected intravitreally before the ischemia. Muller cell damage was assessed by counting the number of s-100-positive cells, and the production of oxidized proteins was analyzed by OxyBlot. The number of macrophages invading the retina was determined by counting the number of ED-1-positive cells.
Results.
The expression of HO-1 mRNA and protein were up-regulated at 6 hours after reperfusion and peaked at 12 to 24 hours, while that of HO-2 was stable. HO-1 immunoreactivities were detected in Muller cells at 24 hours after reperfusion, and HO-2 immunoreactivities were detected in neuronal cells. The HO-1 expression in the retina treated with siRNA of HO-1 was reduced at 12 and 24 hours after reperfusion compared with that injected with siRNA of GFP. The number of s-100-positive cells at 24 hours after reperfusion was decreased significantly in retinas treated with HO-1 siRNA (P<0.01). Oxidized proteins and infiltrated macrophages were increased in retinas pretreated with the siRNA of HO-1 compared with those of siRNA of GFP.
Conclusions.
HO-1 promotes the survival of Muller cells after ischemia-reperfusion injury. Because inhibition of the up-regulation of HO-1 resulted in an infiltration of macrophages, more severe oxidative stress, and destruction of the retina, we conclude that HO-1 plays a neuroprotective role in retinal ischemia-reperfusion.
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