miR-363-3p inhibits rat lung alveolar type II cell proliferation by downregulating STRA6 expression and induces cell apoptosis via cellular oxidative stress and G1-phase cell cycle arrest.

BACKGROUND: miR-363-3p, the retinoid signaling pathway (RSP), and its associated membrane receptor, stimulated by retinoic acid 6 (STRA6), participate in lung development. We hypothesize that miR-363-3p is involved in lung cell proliferation and apoptosis by regulating the expression of STRA6, and this study was designed to investigate the effect of changes in the expressions of miR-363-3p and the STRA6 gene on the proliferation and apoptosis of rat alveolar type II cells. METHODS: To confirm our hypothesis, we used: a dual-luciferase reporter assay; cell culture and transfection; real-time quantitative polymerase chain reaction (PCR); Western blotting; a cell proliferation assay and flow cytometry analysis of the cell cycle, cell apoptosis, oxidative stress level, and mitochondrial membrane potential. RESULTS: Our results showed that STRA6 is a target gene for miR-363-3p, and when the expression of miR-363-3p increased, the relative messenger RNA (mRNA) expression of STRA6 decreased, which caused a decrease in STRA6 protein synthesis and subsequent inhibition of rat lung alveolar type II cell proliferation. In contrast, inhibiting the expression of miR-363-3p promoted the proliferation of these cells. This study also found that an increased expression of miR-363-3p induced rat lung alveolar type II cell apoptosis led to an increase in the oxidative stress level, decreased mitochondrial membrane potential, and an inducement of G1-phase cell cycle arrest. CONCLUSIONS: In conclusion, miR-363-3p is associated with lung cell proliferation and apoptosis, while miR-363-3p inhibits rat lung alveolar type II cell proliferation by downregulating the expression of STRA6 and induces cell apoptosis by increasing cellular oxidative stress and G1-phase cell cycle arrest.

Thoracoscopic versus open resection for symptomatic congenital pulmonary airway malformations in neonates: a decade-long retrospective study.

PURPOSE: The purpose of this study is to evaluate the potential advantages of thoracoscopic versus open resection for symptomatic congenital pulmonary airway malformation (CPAM) in neonates. METHODS: A retrospective review of the medical records of neonates (age ≤ 28 days) who underwent surgery for symptomatic CPAM from 2010 to 2020. RESULTS: Of the 24 patients, 14 patients underwent thoracoscopic resection and 10 patients underwent open resection. 4 patients with CPAM located in the upper or middle lobes underwent lobectomy, and 20 underwent lung-preserving wedge resection in the lower lobe. Between the two groups, there were no statistically significant differences in related preoperative variables, including gestational age at birth, body weight, head circumference, lesion size, cystic adenomatoid malformation volume ratio (CVR), and age at operation (P > .05). The differences in intraoperative variables were statistically significant. The length of the surgical incision was significantly shorter in thoracoscopic resection group than in open resection group (1.4 cm [1.3-1.8] vs. 6.0 cm [5.0-8.0], P = .000), along with significantly less operative blood loss (3 ml [1-6] vs. 5 ml [2-10], P = .030) but significantly longer operation time (159 min [100-220] vs. 110 min [70-170], P = .003). Regarding postoperative variables, ventilator days, duration of chest tube use and length of hospital stay were not statistically significant (P > .05). CONCLUSION: Both thoracoscopic and open resection for symptomatic CPAM achieve good clinical outcomes, even in neonates. Thoracoscopic resection has minimal aesthetic effects and does not increase the risk of surgical or postoperative complications. Lung-preserving resection may be feasible for neonatal CPAM surgery.

Overexpression of miR-455-5p affects retinol (vitamin A) absorption by downregulating STRA6 in a nitrofen-induced CDH with lung hypoplasia rat model.

Lung hypoplasia is the main cause of congenital diaphragmatic hernia (CDH)-associated death but pathogenesis remains unclear. MiR-455-5p is involved in lung hypoplasia. We hypothesized that nitrofen causes abnormal miR-455-5p expression during lung development and designed this study to determine the relationship between miR-455-5p, stimulated by retinoic acid 6 (STRA6), and retinol in a nitrofen-induced CDH with lung hypoplasia rat model. Nitrofen or olive oil was administered to Sprague-Dawley rats by gavage on day 9.5 of gestation, and the rats were divided into a nitrofen group and a control group (n = 6). The left lung of fetuses was dissected on day 15.5. The expression of miR-455-5p or STRA6 messenger RNA (mRNA) was determined by quantitative real-time polymerase chain reaction. Average integrated optical density (IOD) of STRA6 protein was determined by immunofluorescence histochemistry. The average retinol level was detected by enzyme-linked immunosorbent assay (n = 6 lungs, respectively). Compared with the control group, the nitrofen group exhibited significantly increased miR-455-5p expression levels (29.450 ± 9.253 vs 5.955 ± 2.330; P = .00045) and significantly decreased STRA6 mRNA levels (0.197 ± 0.097 vs 0.588 ± 0.184; P = .0047). In addition, the average IOD of the STRA6 protein was significantly lower in the nitrofen group (805.643 ± 291.182 vs 1616.391 ± 572.308, P = .015), and the average retinol level was significantly reduced (4.013 ± 0.195 vs 5.317 ± 0.337 µg/L, P = .000). In summary, the overexpression of miR-455-5p affected retinol absorption by downregulating STRA6 in the nitrofen-induced CDH with lung hypoplasia rat model, and this downregulation may be one cause of CDH with lung hypoplasia.

miR-455-5p Overexpression Reduces Rat Lung Alveolar Type II Cell Proliferation by Downregulating STRA6.

miR-455-5p and retinoid signaling pathway and its membrane receptor, STRA6, are associated with lung development. Software copredictions indicate that the miRNA upstream of the STRA6 gene is miR-455-5p. We hypothesized that miR-455-5p participates in rat lung alveolar Type II cell proliferation by targeting STRA6 and designed this study to investigate the effects of miR-455-5p overexpression on rat lung alveolar Type II cells. Dual luciferase reporter gene assay was utilized to confirm the relationship between miR-455-5p and STRA6. An miR-455-5p-expressing adenoviral vector was constructed and transfected into rat lung alveolar Type II cells. STRA6 protein expression was detected in rat lung alveolar Type II cells by Western blotting at 72 hr posttransfection. Retinol concentration was detected by ELISA at 72 hr posttransfection. The cell proliferation was detected by CCK8 assay at 24, 48, and 72 hr posttransfection. Our results showed that STRA6 is a target gene of miR-455-5p. STRA6 protein expression was significantly lower in the miR-455-5p-overexpression group than in the NC group (0.615 ± 0.131 vs. 0.958 ± 0.246, P = 0.029). Similar results were observed for retinol concentration (2.985 ± 0.061 vs. 3.949 ± 0.118, P = 0.000). Rat lung alveolar Type II cell proliferation was lower in the miR-455-5p-overexpression group than in the NC group at 24, 48, and 72 hr posttransfection (24 hr: 0.280 ± 0.184 vs. 1.354 ± 0.169 P = 0.026; 48 hr: 0.881 ± 0.016 vs. 1.992 ± 0.050 P = 0.001; 72 hr: 2.105 ± 0.148 vs. 2.937 ± 0.079 P = 0.016). In summary, miR-455-5p is associated with lung development. miR-455-5p overexpression downregulates STRA6, leading to reduced retinol concentration and rat lung alveolar Type II cell proliferation. Anat Rec, 302:2062-2069, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

[One stage repairing operation in neonatal hypospadias].

OBJECTIVE: To explore the feasibility of one stage repairing operation on hypospadias in neonatal. METHODS: Sixteen newborn infants with congenital hypospadias dated from May 1998 to Jun. 2004, who was 1 to 29 days old with average 13 days, were performed one stage repairing operation, among whom hypospadias were classified: 4 cases of type I hypospadias, 8 cases of type II, 3 cases of type III and 1 case of type IV. RESULTS: Fourteen cases were cured, 1 case had urethral stricture, and 1 case had fistula. The cure rate of one stage operation was 87.5% (14/16). CONCLUSION: On the premise of the anesthetic safety, one stage hypospadias repairing operation is feasible in some selective cases in neonate.