Kelly Megan L, Wang Meijing, Crisostomo Paul R, Abarbanell Aaron M, Herrmann Jeremy L, Weil Brent R, Meldrum Daniel R
The Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Shock. 2010 Jun;33(6):602-7. doi: 10.1097/SHK.0b013e3181cc0913.
Mesenchymal stem cells (MSCs) may improve myocardial function after I/R injury via paracrine effects, including the release of growth factors. Genetic modification of MSCs is an appealing method to enhance MSC paracrine action. Ablation of TNF receptor 1 (TNFR1), but not TNFR2, increases MSC growth factor production. In this study, therefore, we hypothesized that 1) preischemic infusion of MSCs derived from TNFR1 knockout (TNFR1KO) mice will further improve myocardial functional recovery and that 2) TNFR2KO and TNFR1/2KO will abolish MSC-mediated protection in the heart after I/R injury. Mesenchymal stem cells were harvested from adult C57BL/6J (wild-type 1 [WT1]), B6129SF2 (WT2), TNFR1KO, TNFR2KO, and TNFR1/2KO mice. Mesenchymal stem cells were cultured and adopted for experiments after passage 3. Isolated hearts from adult male Sprague-Dawley rats were subjected to 25 min of ischemia and 40 min of reperfusion (Langendorff model), during which time myocardial function was continuously monitored. Before ischemia, 1 mL of vehicle or 1 x 10(6) MSCs/mL from WT1, WT2, TNFR1KO, TNFR2KO, or TNFR1/2KO was infused into the hearts (n = 4-6 per group). Treatment of C57BL/6J mice with MSC before ischemia significantly increased cardiac function. TNFR1 knockout MSCs demonstrated greater cardioprotection when compared with WT MSCs after I/R, as exhibited by improved left ventricular developed pressure and +/-dp/dt. However, infusion of MSCs from TNFR2KO and TNFR1/2KO mice either offered no benefit or decreased MSC-mediated cardiac functional recovery in response to I/R when compared with WT MSCs. TNFR1 signaling may damage MSC paracrine effects and decrease MSC-mediated cardioprotection, whereas TNFR2 likely mediates beneficial effects in MSCs.
间充质干细胞（MSCs）可能通过旁分泌作用改善心肌缺血/再灌注（I/R）损伤后的心肌功能，包括生长因子的释放。对MSCs进行基因改造是增强其旁分泌作用的一种有吸引力的方法。敲除肿瘤坏死因子受体1（TNFR1）而非TNFR2，可增加MSCs生长因子的产生。因此，在本研究中，我们假设：1）缺血前输注源自TNFR1基因敲除（TNFR1KO）小鼠的MSCs将进一步改善心肌功能恢复；2）TNFR2KO和TNFR1/2KO将消除I/R损伤后MSCs介导的心脏保护作用。从成年C57BL/6J（野生型1 [WT1]）、B6129SF（WT2）、TNFR1KO、TNFR2KO和TNFR1/2KO小鼠中获取间充质干细胞。间充质干细胞经培养并在传代3次后用于实验。将成年雄性Sprague-Dawley大鼠的离体心脏进行25分钟的缺血和40分钟的再灌注（Langendorff模型），在此期间持续监测心肌功能。在缺血前，将1 mL载体溶液或来自WT1、WT2、TNFR1KO、TNFR2KO或TNFR1/2KO的1×10⁶个MSCs/mL注入心脏（每组n = 4 - 6）。缺血前用MSCs治疗C57BL/6J小鼠可显著改善心脏功能。与野生型MSCs相比，TNFR1基因敲除的MSCs在I/R后表现出更强的心脏保护作用，表现为左心室舒张末压和±dp/dt的改善。然而，与野生型MSCs相比，输注来自TNFR2KO和TNFR1/2KO小鼠的MSCs对I/R后的心脏功能恢复要么没有益处，要么降低了MSCs介导的心脏功能恢复。TNFR1信号可能损害MSCs的旁分泌作用并降低MSCs介导的心脏保护作用，而TNFR2可能介导MSCs中的有益作用。
