Li Zhu, Barajas Matthew B, Oyama Takuro, Riess Matthias L
Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Department of Anesthesiology, TVHS VA Medical Center, Nashville, TN 37212, USA.
Cells. 2025 Jun 30;14(13):1001. doi: 10.3390/cells14131001.
Poloxamer (P) 188 attenuates myocardial ischemia/reperfusion injury through cell membrane stabilization. Cell-cell interactions between endothelial cells (ECs) and cardiomyocytes (CMs) further protect CMs: co-cultures showed that, at an optimal density, ECs protected CMs against hypoxia/reoxygenation (HR) injury. The mechanism of interaction with P188 still requires exploration. We examined if N(ω)-nitro-L-arginine methyl ester (LNAME), a non-specific nitric oxide (NO) synthase inhibitor, abolishes protection in the presence or absence of P188 and/or ECs. We co-cultured mouse coronary artery ECs in an insert atop mouse CMs plated at confluency on the bottom of a well. Normoxic controls remained in complete media while HR groups were exposed to 24 h hypoxia at 0.01% O in serum- and glucose-free media, followed by 2 h reoxygenation in complete media. P188 (300 μM), LNAME (40 mM), or vehicle were administered upon reoxygenation. ECs at the used lower density did not decrease HR-triggered lactate dehydrogenase release or calcium overload in CMs by themselves. P188 reduced both indicators after HR by 16/18% without and by 22/25% with ECs, respectively. LNAME abrogated CM protection by P188. Neither intervention had an effect under normoxia. Our co-culture data indicates that P188 requires NO, not necessarily of endothelial origin, to elicit CM protection.
泊洛沙姆（P）188通过稳定细胞膜减轻心肌缺血/再灌注损伤。内皮细胞（ECs）与心肌细胞（CMs）之间的细胞间相互作用可进一步保护CMs：共培养显示，在最佳密度下，ECs可保护CMs免受缺氧/复氧（HR）损伤。与P188相互作用的机制仍需探索。我们研究了非特异性一氧化氮（NO）合酶抑制剂N（ω）-硝基-L-精氨酸甲酯（LNAME）在有或无P188和/或ECs存在时是否会消除这种保护作用。我们将小鼠冠状动脉ECs培养在置于孔底部铺满的小鼠CMs上方的插入物中。常氧对照组置于完全培养基中，而HR组在无血清和无糖培养基中于0.01% O₂条件下暴露于24小时缺氧环境，随后在完全培养基中复氧2小时。复氧时给予P188（300 μM）、LNAME（40 mM）或溶剂。所用较低密度的ECs本身并不会降低HR引发的CMs中乳酸脱氢酶释放或钙超载。P188在无ECs时使HR后的这两个指标分别降低了16/18%，在有ECs时降低了22/25%。LNAME消除了P188对CMs的保护作用。在常氧条件下，两种干预措施均无效果。我们的共培养数据表明，P188需要NO来引发对CMs的保护作用，但不一定来自内皮细胞。
