Quercetin stimulates trophoblast fusion via the mitochondrial function

The fusion of mononuclear trophoblasts into multinucleate syncytiotrophoblasts is the critical event in the process of syncytialization, and its dysregulation can lead to pregnancy complications, notably hypertensive disorders of pregnancy (HDP). Oxidative stress may disrupt trophoblast syncytialization in HDP. Specifically, placentas with HDP exhibit impaired mitochondria, giving rise to the generation of reactive oxygen species (ROS) and subsequent oxidative stress. Quercetin, a bioflavonoid known for its antioxidant and anti-aging properties, has the potential to mitigate oxidative stress during trophoblast syncytialization. However, the precise mechanism underlying the action of quercetin in these processes remains to be elucidated. To explore the impact of quercetin on syncytialization, mitochondrial function, and ROS generation, cyclic AMP-stimulated BeWo cells were treated with quercetin. The expression of markers associated with cell fusion, mitochondrial function, and oxidative stress was determined using qPCR and western blotting. Additionally, morphological syncytialization and mitophagy (mitochondrial degradation) were assessed by immunofluorescence analysis. Our results revealed that quercetin increased the expression of syncytialization markers and promoted cell fusion. Furthermore, this compound also upregulated markers associated with mitophagy and mitochondrial fusion, which are corroborated by visual evidence of mitophagy through the fluorescence microscope. Cell fusion naturally stimulated ROS generation, which was attenuated by quercetin. Quercetin downregulated the expression of NRF2 and HO-1 during syncytialization, while increasing the expression of sirtuin1/3/6, which are known to play essential roles in antioxidant responses. In conclusion, quercetin effectively regulates mitochondrial function through its antioxidant properties and the suppression of ROS generation, ultimately promoting trophoblast fusion, suggesting that the flavonoid has the potential to ameliorate pregnancy-related disorder stemming from placental dysplasia.

[Extended septoplasty for left ventricular outflow tract obstruction after the intracardiac repair of double outlet right ventricle]

A 14-year-old boy with a left ventrivular outflow tract obstruction (LVOTO) after the repair of double outlet right ventricle (DORV) at the age of 7 months was successfully treated with an extended septoplasty. A significant pressure gradient occurred between the left ventricle and the ascending aorta of 70 mmHg in spite of the previous surgery for LVOTO with muscle resection and the ventricular septal defect (VSD) patch enlargement at the age of 5. An extended septoplasty was performed including extensive resection of the conus muscle and the previously placed patch, long incision on the interventricular septum toward the apex, and reconstruction of the outflow tract using a Hemashield patch. The cathterization 10 months after the operation revealed an effective relief of LVOTO with left ventricle (LV) and aorta (Ao) pressure of 115 and 103 mmHg, respectively. An extended septoplasy is effective for the relief of LVOTO, but further follow-up is mandatory of both the left ventricular function and mitral valve function.