Deletion of iNOS gene impairs mouse fracture healing
Deletion of iNOS gene impairs mouse fracture healing
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DOI：
10.1016/j.bone.2004.10.002
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发表时间：
2005-07-01
期刊：
影响因子：
4.1
通讯作者：
Murrell, GAC
中科院分区：
文献类型：
--
作者：
Baldik, Y;Diwan, AD;Murrell, GAC
一氧化氮(NO)是一氧化氮合酶(NOSS)催化L-精氨酸合成的一种信号分子。一氧化氮合酶亚型可分为内皮型一氧化氮合酶[eNOS]和神经型一氧化氮合酶[nNOS]或诱导型一氧化氮合酶(INOS)。此前，我们的研究小组已经报道，NO在骨折愈合过程中表达并调节骨折愈合。在这项研究中，我们通过使用iNOS基因治疗iNOS缺陷小鼠来评估iNOS在骨折愈合中的特异性贡献。12周龄雌性野生型小鼠和iNOS-KO小鼠接受右侧股骨中段截骨术，用直径0.5 mm的髓内针固定。一块明胶海绵被植入骨折处。明胶海绵以10(7)pfu的剂量接受Ad5-CMViNOS(在iNOS缺陷小鼠中，n=16)或Ad5-CMV Empty(在野生型小鼠中，n=15，在iNOS缺陷小鼠中，n=15)。第14天处死小鼠，取右后肢和左后肢。用游标卡尺测量骨痂在内侧平面和前后平面的直径，以确定横截面积(CSA)。在双轴Instron测试系统中对试件进行扭转加载，测定最大扭矩、扭转刚度、最大能量和总能量。与野生型小鼠相比，iNOS基因缺失使愈合的股骨骨折的总能量和最大能量吸收分别减少30%和70%(P<；0.01)。通过腺病毒载体给予iNOScDNA可逆转这种能量吸收的减少。此外，与未接受iNOScDNA的iNOS(-/-)小鼠相比，iNOScDNA导致的扭转失败增加了20%(P=0.01)。在完整股骨的生物力学性能方面没有显著差异，这些数据表明iNOS在小鼠骨折愈合中起着重要作用。然而，一氧化氮合酶基因治疗促进骨折愈合的临床应用还需要进一步的评估。(C)2004 Elsevier Inc.保留所有权利。
Nitric oxide (NO) is a signaling molecule synthesized from L-arginine by nitric oxide synthases (NOSs). NOS isoforms are either constitutive (endothelial NOS [eNOS] and neuronal NOS [nNOS]) or inducible NOS (iNOS). Previously, our group has reported that NO is expressed during and modulates fracture healing. In this study, we evaluated the specific contribution of iNOS to fracture healing by using iNOS gene therapy in iNOS-deficient mice. Twelve-week-old female wild-type mice and iNOS-KO mice had a right femoral midshaft osteotomy fixed with an intramedullary 0.5-mm-diameter needle. A gelatine sponge was implanted across the fracture site. The gelatine sponge received either Ad5-CMViNOS (in iNOS-deficient mice; n = 16) or Ad5-CMVempty (in wild-type mice; n = 15, and iNOS-deficient mice; n = 15) at a dose of 10(7) pfu. Mice were sacrificed at day 14, and their right and left hind limbs were harvested. Cross-sectional area (CSA) was determined by measuring the callus diameter across the mediolateral and anteroposterior plane using a vernier caliper. Specimens were loaded to failure torsionally in a biaxial INSTRON testing system, and maximum torque, torsional stiffness, and maximal and total energy were determined.Deletion of the iNOS gene decreased the total and maximum energy absorption of the healing femoral fracture by 30% and by 70% (P < 0.01), respectively, in comparison to the wild-type mice. This reduction in energy absorption was reversed by iNOScDNA administration via adenovirus vector. Furthermore, iNOScDNA caused an increase in torsional failure by 20% (P = 0.01) in comparison to iNOS(-/-) mice that did not receive the iNOScDNA. There were no significant differences in the biomechanical properties of intact femora.These data indicate that iNOS is important in mouse fracture healing. However, the clinical utility of NOS gene therapy to enhance fracture healing will need further evaluation. (C) 2004 Elsevier Inc. All rights reserved.