Autophagy is impaired in fetal hypoplastic lungs and rescued by administration of amniotic fluid stem cell extracellular vesicles

Rationale: Pulmonary hypoplasia secondary to congenital diaphragmatic hernia (CDH) is characterized by reduced branching morphogenesis, which is responsible for poor clinical outcomes. Administration of amniotic fluid stem cell extracellular vesicles (AFSC-EVs) rescues branching morphogenesis in rodent fetal models of pulmonary hypoplasia. Herein, we hypothesized that AFSC-EVs exert their regenerative potential by affecting autophagy, a process required for normal lung development. Objectives: To evaluate autophagy in hypoplastic lungs throughout gestation and establish whether AFSC-EV administration improves branching morphogenesis through autophagy-mediated mechanisms. Methods: EVs were isolated from c-kit+ AFSC conditioned medium by ultracentrifugation and characterized for size, morphology, and EV markers. Branching morphogenesis was inhibited in rat fetuses by nitrofen administration to dams and in human fetal lung explants by blocking RAC1 activity with NSC23766. Expression of autophagy activators (BECN1 and ATG5) and adaptor (SQSTM1/p62) was analyzed in vitro (rat and human fetal lung explants) and in vivo (rat fetal lungs). Mechanistic studies on rat fetal primary lung epithelial cells were conducted using inhibitors for microRNA-17 and -20a contained in the AFSC-EV cargo and known to regulate autophagy. Measurements and Main Results: Rat and human models of fetal pulmonary hypoplasia showed reduced autophagy mainly at pseudoglandular and canalicular stages. AFSC-EV administration restored autophagy in both pulmonary hypoplasia models by transferring miR-17~92 cluster members contained in the EV cargo. Conclusions: AFSC-EV treatment rescues branching morphogenesis partly by restoring autophagy through miRNA cargo transfer. This study enhances our understanding of pulmonary hypoplasia pathogenesis and creates new opportunities for fetal therapeutic intervention in CDH babies.

Amniotic fluid stem cell extracellular vesicles promote fetal lung branching and cell differentiation in experimental congenital diaphragmatic hernia

Pulmonary hypoplasia secondary to congenital diaphragmatic hernia (CDH) is characterized by impaired branching morphogenesis and differentiation. We have previously demonstrated that administration of extracellular vesicles derived from rat amniotic fluid stem cells (AFSC-EVs) rescues development of hypoplastic lungs at the pseudoglandular and alveolar stages in rodent models of CDH. Herein, we tested whether AFSC-EVs exert their regenerative effects at the canalicular and saccular stages, as these are translationally relevant for clinical intervention. To induce fetal pulmonary hypoplasia, we gavaged rat dams with nitrofen at embryonic day 9.5 and demonstrated that nitrofen-exposed lungs had impaired branching morphogenesis, dysregulated signaling pathways relevant to lung development (FGF10/FGFR2, ROBO/SLIT, Ephrin, Neuropilin 1, beta-catenin) and impaired epithelial and mesenchymal cell marker expression at both stages. AFSC-EVs administered to nitrofen-exposed lung explants rescued airspace density and increased the expression levels of key factors responsible for branching morphogenesis. Moreover, AFSC-EVs rescued the expression of alveolar type 1 and 2 cell markers at both canalicular and saccular stages, and restored markers of club, ciliated epithelial, and pulmonary neuroendocrine cells at the saccular stage. AFSC-EV treated lungs also had restored markers of lipofibroblasts and PDGFRA+ cells to control levels at both stages. EV tracking showed uptake of AFSC-EV RNA cargo throughout the fetal lung and an mRNA-miRNA network analysis identified that several miRNAs responsible for regulating lung development processes were contained in the AFSC-EV cargo. These findings suggest that AFSC-EV based therapies hold potential for restoring fetal lung growth and maturation in babies with pulmonary hypoplasia secondary to CDH.

Case Report: Pregnancy with Fetal Hydrathorax

Background: Cases of fetal hydrothorax (FHT) are rare, with an occurrence probability of 1 in every 10,000-15,000 pregnancies. The condition may remain undiagnosed, and the fetus may be aborted, or death may occur soon after birth in outlying hospitals before transfer to a tertiary care center. The incidence rate of FHT is higher in males than females (2:1). One of the most effective methods of diagnosing fetal hydrothorax is sonography. Three forms of currently available treatments are: thoracentesis, thoracoamniotic shunting (TAS), and thoracomaternal cutaneous drainage. Fetal outcomes could be improved by performing the Extrauterine Intrapartum Treatment (EXIT) procedure.Case Presentation: We present two cases of first pregnancy primary FHT. In the first case, a 24-year-old woman was diagnosed with asymptomatic FHT in the 28th week of gestation without any prior history. In the second case, a 22-year-old woman with poor medical history was diagnosed in the 35th week of pregnancy and was experienced difficulty of breathing. Both pregnancies were delivered by cesarean section based on obstetric indications. Thoracentesis was performed on both neonates, and pathological examination of the pleural fluid was conducted. However, they died shortly after birth.Conclusion: The EXIT procedure is still a challenging method. A fetus with FHT is at significant risk of pulmonary hypoplasia and respiratory distress following delivery. Early diagnosis and intervention of FHT are vital to ensure a good prognosis. Approaching multidisciplinary groups, providing supportive diagnostic facilities and financial support is essential in improving fetal outcomes and preventing FHT in subsequent pregnancies.

Matthew-Wood Syndrome in Monochorionic, Diamnionic Twins

Matthew-Wood syndrome represents a rare genetic disorder characterized by diaphragmatic defects, pulmonary hypoplasia, micro- or anophthalmia, and cardiac defects. Most cases are lethal with very few infants living beyond a few years of life. Siblings with this diagnosis have been reported but never twins. In this article, we provided a review and discussion of this syndrome following its presentation in monochorionic, diamnionic twin females.

Congenital Diaphragmatic Hernia: Core Review and Novel Updates

Congenital diaphragmatic hernia (CDH) is a developmental defect in the diaphragm that allows abdominal viscera to herniate into the thoracic cavity. Pulmonary hypoplasia and pulmonary hypertension are consequences of this disease process. The incidence is approximately 2.4–4.1/10,000 births, and survival rate is estimated at 70–90 percent. To avoid potentially devastating delays in care, it is crucial that neonatal nurses and care providers in both tertiary and nontertiary care centers be familiar with the pathogenesis of CDH and the standard of care for initial stabilization of the neonate. Novel fetal and postnatal surgical repair techniques are also described here.

Clinical case of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a rare congenital anomaly of diaphragmatic development with a frequency of approximately 1 in 2,500 live births. The structural defect is accompanied by pathophysiological disorders, in particular, pulmonary hypertension, as well as pulmonary hypoplasia of various degrees, which actually determine the severity of the defect. In 84% of cases, the diaphragmatic hernia is located on the left dome of the diaphragm, possible right-sided and left-sided localization of the malformation, which is 14 and 2%, respectively.The defect can be either isolated or combined with other congenital anomalies, such as congenital heart disease or chromosomal abnormalities. Violation of the closure of the diaphragm during the 4-10th week of fetal development leads to the formation of the diaphragmatic grid. During the same period (5th week of gestation) is the formation of lungs and bronchs. Three-dimensional ultrasound diagnosis allows to detect prenatal defect in almost 60% of fetuses. Fetal MRI is a method of choosing the anatomical assessment of the lungs, determining their volume allows you to more accurately predict the development of complications and the required amount of care after birth. The article is devoted to the description of clinical observation of ENT with a description of the features of perinatal diagnosis and organization of postnatal care. The defect was diagnosed at 31 weeks, vaginal delivery occurred during full-term pregnancy. The complex of resuscitation measures, preoperative preparation, the course of the postoperative period is described. Timely prenatal diagnosis of EDC and its anatomical variant makes it possible to correctly develop the patient’s route, starting with the tactics of pregnancy, method of delivery, as well as to predict the algorithm of staff actions at birth and subsequent treatment of the newborn.