Mitochondrial damage associated molecular patterns from femoral reamings activate neutrophils through formyl peptide receptors and P44/42 MAP kinase.
Mitochondrial damage associated molecular patterns from femoral reamings activate neutrophils through formyl peptide receptors and P44/42 MAP kinase.
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DOI：
10.1097/bot.0b013e3181ec4991
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发表时间：
2010-09
影响因子：
2.3
通讯作者：
Itagaki K
中科院分区：
文献类型：
--
作者：
Hauser CJ;Sursal T;Rodriguez EK;Appleton PT;Zhang Q;Itagaki K
骨折和股骨扩孔与肺损伤有关。骨折和炎症之间的联系机制尚不清楚；但组织破坏可能会释放线粒体。线粒体从细菌进化而来，含有“损伤相关分子模式”（DAMPs），如甲酰化肽，可以激活免疫细胞。因此，我们研究了裂缝扩孔是否释放线粒体DAMPs （MTD）以及MTD如何作用于免疫细胞。将10例患者的股骨骨折片（FFx）旋转去除骨颗粒。检测上清液中线粒体DNA （mtDNA）。从剩余的扩孔浆液中分离线粒体，在12,000g下超声和纺丝。在有或没有甲酰基肽受体-1 （FPR1）阻断的情况下，测定了所得到的MTD引起中性粒细胞（PMN） Ca2+瞬时产生、p44/42 MAPK磷酸化、IL-8释放和基质金属蛋白酶-9 （MMP9）释放的能力。给大鼠注射MTD，检测全肺p44/42的激活情况。在FFx患者中，mtDNA的水平是正常血浆水平的数千倍，而在患者血浆中则处于中等水平，这表明mtDNA从骨折释放到血浆中。FFx MTD引起PMN Ca2+通量活跃，激活PMN p44/42 MAPK，引起PMN释放IL-8和MMP9。用环孢素H和抗FPR1阻断FPR1抑制MTD的应答。MTD注射引起大鼠肺组织P44/42磷酸化。FFx扩孔将线粒体释放到伤口和血液循环中。然后MTD激活PMN。FFx释放的MTD等损伤信号可能是已知与骨折固定和肺损伤相关的细胞因子级联激活的基础。
Fractures and femoral reaming are associated with lung injury. The mechanisms linking fractures and inflammation are unclear; but tissue disruption might release mitochondria. Mitochondria are evolutionarily derived from bacteria and contain “Damage Associated Molecular Patterns” (DAMPs) like formylated peptides that can activate immunocytes. We therefore studied whether fracture reaming releases mitochondrial DAMPs (MTD) and how MTD act on immune cells. Femur fracture reamings (FFx) from 10 patients were spun to remove bone particulates. Supernatants were assayed for mitochondrial DNA (mtDNA). Mitochondria were isolated from the residual reaming slurry, sonicated and spun at 12,000g. The resultant MTD were assayed for their ability to cause neutrophil (PMN) Ca2+ transient production, p44/42 MAPK phosphorylation, IL-8 release and matrix metalloproteinase-9 (MMP9) release with and without formyl peptide receptor-1 (FPR1) blockade. Rats were injected with MTD and whole lung assayed for p44/42 activation. mtDNA appears at many thousand fold normal plasma levels in FFx and at intermediate levels in patients’ plasma, suggesting release from fracture to plasma. FFx MTD caused brisk PMN Ca2+ flux, activated PMN p44/42 MAPK and caused PMN release of IL-8 and MMP9. Responses to MTD were inhibited by FPR1 blockade using Cyclosporin H and anti-FPR1. MTD injection caused P44/42 phosphorylation in rat lung. FFx reaming releases mitochondria into the wound and circulation. MTD then activates PMN. Release of damage signals like MTD from FFx may underlie activation of the cytokine cascades known to be associated with facture fixation and lung injury.