Endoplasmic reticulum stress response is activated in pulmonary hypoplasia secondary to congenital diaphragmatic hernia, but is decreased by administration of amniotic fluid stem cells.

PURPOSE: Pulmonary hypoplasia secondary to congenital diaphragmatic hernia (CDH) is characterized by impaired epithelial homeostasis. Recently, amniotic fluid stem cells (AFSCs) have been shown to promote growth in hypoplastic lungs of rat fetuses with CDH. Herein, we investigated whether CDH hypoplastic lungs mount an endoplasmic reticulum (ER) stress response and whether AFSCs could re-establish pulmonary epithelial homeostasis. METHODS: Primary epithelial cells were isolated from fetal rat lungs at E14.5 from control and nitrofen-exposed dams at E9.5. Nitrofen-exposed epithelial cells were grown in medium alone or co-cultured with AFSCs. Epithelial cell cultures were compared for apoptosis (TUNEL), cytotoxicity (LIVE/DEAD assay), proliferation (5'EdU), and ER stress (CHOP, Bcl-2) using one-way ANOVA (Dunn's post-test). RESULTS: Compared to control, nitrofen-exposed epithelial cells had increased cytotoxicity and apoptosis, reduced proliferation, and activated ER stress. AFSCs restored apoptosis, proliferation, and ER stress back to control levels, and significantly reduced cytotoxicity. CONCLUSIONS: This study shows for the first time that ER stress-induced apoptosis is activated in the pulmonary epithelium of hypoplastic lungs from fetuses with CDH. AFSC treatment restores epithelial cellular homeostasis by attenuating the ER stress response and apoptosis, by increasing proliferation and migration ability, and by reducing cytotoxicity.

Pitfalls and Possibilities of Ventricular Assist Device Support in Congenitally Corrected Transposition of the Great Arteries in Children.

Congenitally corrected transposition of the great arteries (ccTGAs) represents a complex form of congenital heart disease that is associated with several cardiac complications. Herein is a case series of three children with ccTGA and ventricular assist device (VAD) inserted for systemic right ventricle failure at a single institution. All patients remained hemodynamically stable postimplant and were successfully discharged from the intensive care unit to undergo postoperative rehabilitation. All three patients received an orthotopic heart transplant with uneventful posttransplant courses. This case series provides insight into the medical management and technical feasibility of VAD support in children with ccTGA with end-stage heart failure.

Cellular senescence contributes to age-dependent changes in circulating extracellular vesicle cargo and function.

Extracellular vesicles (EVs) have emerged as important regulators of inter-cellular and inter-organ communication, in part via the transfer of their cargo to recipient cells. Although circulating EVs have been previously studied as biomarkers of aging, how circulating EVs change with age and the underlying mechanisms that contribute to these changes are poorly understood. Here, we demonstrate that aging has a profound effect on the circulating EV pool, as evidenced by changes in concentration, size, and cargo. Aging also alters particle function; treatment of cells with EV fractions isolated from old plasma reduces macrophage responses to lipopolysaccharide, increases phagocytosis, and reduces endothelial cell responses to vascular endothelial growth factor compared to cells treated with young EV fractions. Depletion studies indicate that CD63+ particles mediate these effects. Treatment of macrophages with EV-like particles revealed that old particles increased the expression of EV miRNAs in recipient cells. Transfection of cells with microRNA mimics recapitulated some of the effects seen with old EV-like particles. Investigation into the underlying mechanisms using bone marrow transplant studies revealed circulating cell age does not substantially affect the expression of aging-associated circulating EV miRNAs in old mice. Instead, we show that cellular senescence contributes to changes in particle cargo and function. Notably, senolytic treatment of old mice shifted plasma particle cargo and function toward that of a younger phenotype. Collectively, these results demonstrate that senescent cells contribute to changes in plasma EVs with age and suggest a new mechanism by which senescent cells can affect cellular functions throughout the body.