Multiaxial Lenticular Stress-Strain Relationship of Native Myocardium is Preserved by Infarct-Induced Natural Heart Regeneration in Neonatal Mice.
Multiaxial Lenticular Stress-Strain Relationship of Native Myocardium is Preserved by Infarct-Induced Natural Heart Regeneration in Neonatal Mice.
复制标题
新生小鼠梗死诱导的自然心脏再生保留了天然心肌的多轴晶状体应力-应变关系。
DOI：
10.1038/s41598-020-63324-w
复制
发表时间：
2020
影响因子：
4.6
通讯作者：
Zhu,Yu
中科院分区：
文献类型：
--
作者：
Wang,Hanjay;Bennett-Kennett,Ross;Paulsen,MichaelJ;Hironaka,CamilleE;Thakore,AksharaD;Farry,JustinM;Eskandari,Anahita;Lucian,HaleyJ;Shin,HyeSook;Wu,MatthewA;Imbrie-Moore,AnnabelM;Steele,AmandaN;Stapleton,LyndsayM;Zhu,Yu
新生小鼠在心肌梗塞（MI）后第 1 天（P1）表现出自然心脏再生能力，但这种能力在出生后第 7 天（P7）丧失。心脏生物力学错综复杂地影响长期心脏功能，但再生心肌在生物力学上是否与天然心肌相似仍不清楚。我们假设，心肌梗死后，新生儿心脏再生保留了原生左心室 (LV) 生物力学特性。 C57BL/6J 小鼠在 P1 或 P7 龄时接受假手术或左冠状动脉前降支结扎。 MI 后 4 周进行的超声心动图显示，P1 MI 和假小鼠（n = 22，每只）具有相似的 LV 壁厚度、直径和射血分数（59.6% vs 60.7%，p = 0.6514）。与 P7 假小鼠 (n = 20) 相比，P7 MI 小鼠 (n = 20) 具有显着的左室壁变薄、心室扩大和射血分数降低 (32.6% vs 61.8%, p< 0.0001)。随后，将左心室移植并离体加压，并跟踪多轴晶状体应力-应变关系。虽然 P1 MI 和假小鼠的 LV 组织模量相似（341.9 kPa 对比 363.4 kPa，p = 0.6140），但 P7 MI 小鼠的左室组织模量显着大于 P7 假小鼠（691.6 kPa 对比 429.2 kPa，p = 0.0194）。我们的结论是，在新生小鼠中，再生的左心室肌肉具有与天然左心室心肌相似的生物力学特性。
Neonatal mice exhibit natural heart regeneration after myocardial infarction (MI) on postnatal day 1 (P1), but this ability is lost by postnatal day 7 (P7). Cardiac biomechanics intricately affect long-term heart function, but whether regenerated cardiac muscle is biomechanically similar to native myocardium remains unknown. We hypothesized that neonatal heart regeneration preserves native left ventricular (LV) biomechanical properties after MI. C57BL/6J mice underwent sham surgery or left anterior descending coronary artery ligation at age P1 or P7. Echocardiography performed 4 weeks post-MI showed that P1 MI and sham mice (n = 22, each) had similar LV wall thickness, diameter, and ejection fraction (59.6% vs 60.7%, p = 0.6514). Compared to P7 shams (n = 20), P7 MI mice (n = 20) had significant LV wall thinning, chamber enlargement, and depressed ejection fraction (32.6% vs 61.8%, p < 0.0001). Afterward, the LV was explanted and pressurizedex vivo, and the multiaxial lenticular stress-strain relationship was tracked. While LV tissue modulus for P1 MI and sham mice were similar (341.9 kPa vs 363.4 kPa, p = 0.6140), the modulus for P7 MI mice was significantly greater than that for P7 shams (691.6 kPa vs 429.2 kPa, p = 0.0194). We conclude that, in neonatal mice, regenerated LV muscle has similar biomechanical properties as native LV myocardium.