The role of endogenously produced extracellular hsp72 in mononuclear cell reprogramming.
The role of endogenously produced extracellular hsp72 in mononuclear cell reprogramming.
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DOI：
10.1097/shk.0b013e318164e2c3
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发表时间：
2008-09
期刊：
影响因子：
--
通讯作者：
Wheeler DS
中科院分区：
文献类型：
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作者：
Abboud PA;Lahni PM;Page K;Giuliano JS Jr;Harmon K;Dunsmore KE;Wong HR;Wheeler DS
细胞内热休克蛋白72（Hsp 72）具有广泛的细胞保护作用。最近的数据表明，应激细胞可以释放热休克蛋白72到细胞外室，虽然细胞外热休克蛋白72的生物学功能仍有待充分阐明。由于细胞外热休克蛋白72已被证明与Toll样受体4相互作用，我们假设内源性产生和释放的热休克蛋白72将重新编程单核细胞对LPS的反应。用LPS处理的THP-1细胞用作核因子（NF）-κB活化的模型。热休克条件包括在43°C下孵育1小时。将对照细胞在37°C下孵育。孵育后24小时，离心热休克条件培养基（HSCM）和对照培养基（CM），弃去相应的细胞。然后将单独的一组初始THP-1细胞与HSCM或CM孵育18小时，然后用LPS（1 μg/mL）刺激。与CM相比，热休克显著增加HSCM中的Hsp 72。在用NF-κB荧光素酶报告质粒转染的THP-1细胞中，与在CM中孵育的细胞相比，加入HSCM减弱了随后LPS介导的荧光素酶活性。加入HSCM还减弱LPS介导的NF-κB-DNA结合和IκBα降解。热休克蛋白72介导的NF-κB活化抑制进一步被TNF-α产生的显著减少所证实。当HSCM和CM通过三磷酸腺苷-琼脂糖结合进行Hsp 72耗竭时，LPS介导的NF-κB活化部分恢复，表明Hsp 72部分负责响应HSCM的细胞重编程。这些数据表明，内源性产生和释放的细胞外热休克蛋白72有能力在体外培养的人单核细胞内重新编程内毒素的反应。
Intracellular heat shock protein 72 (Hsp72) is known to serve a broad cytoprotective role. Recent data indicate that stressed cells can release Hsp72 into the extracellular compartment, although the biological function of extracellular Hsp72 remains to be fully elucidated. Because extracellular Hsp72 has been demonstrated to interact with Toll-like receptor 4, we hypothesized that endogenously produced and released Hsp72 would reprogram the mononuclear cell responses to LPS. THP-1 cells treated with LPS were used as a model for nuclear factor (NF)–κB activation. Heat shock conditions consisted of incubation at 43°C for 1 h. Control cells were incubated at 37°C. Twenty four hours after incubation, heat shock conditioned media (HSCM) and control media (CM) were centrifuged, and the respective cells were discarded. A separate group of naive THP-1 cells were then incubated with either HSCM or CM for 18 h and then stimulated with LPS (1 µg/mL). Heat shock significantly increased Hsp72 in HSCM compared with CM. In THP-1 cells transfected with an NF-κB luciferase reporter plasmid, the addition of HSCM attenuated subsequent LPS-mediated luciferase activity compared with cells incubated in CM. The addition of HSCM also attenuated LPS-mediated NF-κB–DNA binding and IκBα degradation. Heat shock protein 72–mediated inhibition of NF-κB activation was further corroborated by a significant decrease in TNF-α production. When HSCM and CM were subjected to Hsp72 depletion via adenosine triphosphate–agarose binding, LPS-mediated activation of NF-κB was partially restored, suggesting that Hsp72 is partially responsible for cellular reprogramming in response to HSCM. These data demonstrate that endogenously produced and released extracellular Hsp72 has the ability to reprogram the in vitro response to endotoxin in cultured human mononuclear cells.