PPCM and the endocrine system

Pregnancy and cardiovascular disease

Cardiovascular disease complicates 1-4% of pregnancies - with a higher prevalence when including hypertensive disorders - and is the leading cause of maternal death. In women with known cardiovascular pathology, such as congenital heart disease, timely counselling is possible and the outcome is fairly good. By contrast, maternal mortality is high in women with acquired heart disease that presents during pregnancy (such as acute coronary syndrome or aortic dissection). Worryingly, the prevalence of acquired cardiovascular disease during pregnancy is rising as older maternal age, obesity, diabetes mellitus and hypertension become more common in the pregnant population. Management of cardiovascular disease in pregnancy is challenging owing to the unique maternal physiology, characterized by profound changes to multiple organ systems. The presence of the fetus compounds the situation because both the cardiometabolic disease and its management might adversely affect the fetus. Equally, avoiding essential treatment because of potential fetal harm risks a poor outcome for both mother and child. In this Review, we examine how the physiological adaptations during pregnancy can provoke cardiometabolic complications or exacerbate existing cardiometabolic disease and, conversely, how cardiometabolic disease can compromise the adaptations to pregnancy and their intended purpose: the development and growth of the fetus.

β1 adrenoceptor antibodies induce myocardial apoptosis via inhibiting PGC-1α-related pathway

Background

Peripartum cardiomyopathy (PPCM) is life-threatening heart disease. However, the causes and pathogenesis of PPCM remain unclear. Previous studies found that β1 adrenoceptor antibodies (β1AA) had possible involvement in the development of PPCM. In the present study, we determined the potential relationship between PPCM and β1AA, including the mechanism of β1AA leading to PPCM.

Methods

We extracted the β1AA from the postpartum Wistar rats that were injected by the antigen peptide segment of the β1 adrenoceptor to produce PPCM. We tested the effects of β1AA on H9C2 cell line by CCK-8, LDH, TUNEL, SA-ELISA, qRT-PCR, and western blot methods. Furthermore, PGC-1α was overexpressed to rescue the effect of β1AA on H9C2 cells.

Results

We found that the extracted β1AA induced apoptosis of cardiac myocytes of H9C2 cell line. Moreover, the expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), which is a master regulator of mitochondrial metabolism, and its downstream transcript vascular endothelial growth factor (VEGF) got decreased in H9C2 cells after β1AA treatment. In addition, the effect of β1AA could be inhibited by atenolol, the antagonist of β1 adrenoceptors (β1AR) and imitated by isoprenaline, the agonist of β1AR. Furthermore, overexpression of PGC-1α in the H9C2 cells rescued the apoptosis of cells and inhibitory expression of VEGF induced by β1AA.

Conclusions

Our results suggest that the symptoms of PPCM due to myocardial cell apoptosis induced by β1AA inhibiting the PGC-1α-related pathway impairs mitochondrial energy metabolism. Therefore, our results uncover a previously unknown role of the β1AA pathway in the etiology of PPCM and provide a novel potential target for the treatment of PPCM.