Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina, United States.
Am J Physiol Heart Circ Physiol. 2024 Nov 1;327(5):H1155-H1161. doi: 10.1152/ajpheart.00459.2024. Epub 2024 Sep 13.
Lymphatic vessels of the heart undergo dynamic remodeling in response to physiological and pathological cardiovascular events such as development, adult cardiac maintenance, and injury repair. During pregnancy, the cardiovascular system undergoes physiological changes to meet the increased demand for blood supply to the fetus. These extensive physiological changes make pregnancy and delivery a high-risk period in a woman's life. However, whether and how cardiac lymphatics change during pregnancy is largely undefined. Therefore, we used whole mount immunofluorescent labeling and quantitative morphometric analysis to characterize the changes in cardiac lymphatic vasculature during pregnancy using two genetically distinct inbred mouse strains, C57BL/6J and BALB/cJ. When compared with age-matched, nonpregnant C57BL/6J control mice, the hearts of C57BL/6J dams in late pregnancy [ (G17.5)] undergo physiological hypertrophy. However, there were no significant changes in the cardiac lymphatic vasculature. In contrast, BALB/cJ mice do not exhibit pregnancy-induced cardiac hypertrophy at G17.5 compared with age-matched, nonpregnant mice. Yet interestingly, the cardiac lymphatic vasculature of pregnant BALB/cJ dams undergoes extensive morphological changes, including decreased lymphatic length, number of end points, and vessel branch-point junctions on the ventral side of the heart. These findings underscore the complexity of genetic and physiological factors that contribute to the heterotypic remodeling of cardiac lymphatics during late pregnancy. Cardiac lymphatics remodel in response to physiological and pathological stresses. This study is the first to investigate cardiac lymphatic vessel changes during pregnancy. BALB/cJ mice, which do not undergo pregnancy-induced cardiac hypertrophy, show decreased lymphatic length, number of end points, and junctions on the ventral side during pregnancy. In contrast, C57BL/6J mice, which undergo pregnancy-induced cardiac hypertrophy, had no such changes. These findings underscore the complexity of genetic and physiological factors contributing to cardiac lymphatic remodeling.
心脏的淋巴管会对生理和病理心血管事件（如发育、成年心脏维持和损伤修复）做出动态重塑。在怀孕期间，心血管系统会发生生理变化，以满足胎儿对血液供应的增加需求。这些广泛的生理变化使怀孕和分娩成为女性生命中的高危时期。然而，心脏淋巴管在怀孕期间是否以及如何发生变化在很大程度上尚未明确。因此，我们使用两种不同的近交系小鼠（C57BL/6J 和 BALB/cJ），通过全铺免疫荧光标记和定量形态计量分析来描述怀孕期间心脏淋巴管的变化。与年龄匹配的非怀孕 C57BL/6J 对照小鼠相比，怀孕晚期（G17.5）的 C57BL/6J 孕鼠心脏发生生理性肥大。然而，心脏淋巴管没有明显变化。相比之下，与年龄匹配的非怀孕小鼠相比，BALB/cJ 小鼠在 G17.5 时不会发生妊娠诱导的心脏肥大。然而，有趣的是，怀孕 BALB/cJ 孕鼠的心脏淋巴管发生了广泛的形态变化，包括心脏腹侧面的淋巴管长度、终点数量和血管分支点连接处减少。这些发现强调了遗传和生理因素的复杂性，这些因素导致了妊娠晚期心脏淋巴管的异型重塑。心脏淋巴管会对生理和病理压力做出反应而进行重塑。本研究首次调查了怀孕期间心脏淋巴管的变化。BALB/cJ 小鼠不发生妊娠诱导的心脏肥大，但在怀孕期间腹侧面的淋巴管长度、终点数量和连接处减少。相比之下，发生妊娠诱导的心脏肥大的 C57BL/6J 小鼠则没有这些变化。这些发现强调了导致心脏淋巴管重塑的遗传和生理因素的复杂性。
