The effect of vascular endothelial growth factor for the treatment of congenital diaphragmatic hernia in the fetus.

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 14571699
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Pediatric surgery
• Research Institution: Chiba University
• Principal Investigator: KOUCHI Katsunor Chiba University, hospital, Research Associate, 医学部附属病院, 助手 (40312938)
• Co-Investigator(Kenkyū-buntansha): MATSUNAGA Tadashi Chiba University, hospital, Assistant Professor, 医学部附属病院, 講師 (80302561) ; YOSHIDA Hideo Chiba University, Graduate School of Medicine, Associate Professor, 大学院・医学研究院, 助教授 (60210712) ; OHNUMA Naomi Chiba University, Graduate School of Medicine, Professor, 大学院・医学研究院, 教授 (50125910)
• Project Period (FY): 2002 – 2005
• Keywords: congenital diaphragmatic hernia / fetal therapy / vascular endothelial growth factor

Research Abstract

Purpose : Recent studies reported that neonates with congenital diaphragmatic hernias (CDH) diagnosed parentally showed poor prognosis. Neonates with congenital diaphragmatic hernias diagnosed parentally had the thickness of muscular layer of lung artery. The mechanisms caused severe pulmonary hypertension soon after birth. The mechanisms of the thickness of muscular layer of lung artery have been unknown. To reveal this mechanism, we analyzed major factor of vascular remodeling ; vascular endothelial growth factor (VEGF), angiopoietin (Ang) in the CDH model rats.
Methods : CDH model rat was made by oral intake of Nitrofen 100mg in 1ml of olive oil at GA 9.5 days pregnant rats. At GA 17, 19, 21 days, fetuses were delivered by cesarean section. The lung tissue was obtained under microscopy. We classified fetus into two groups ; CDH-;CDH was not observed under microscopy and CDH+;CDH was not observed under microscopy. The control group was made by oral intake of 1ml of olive oil at GA 9.5 days pregnant rats. We analyzed mRNA levels of VEGF, its receptor ; FLK1, Ang-1, Ang-2, its receptor ; TIE2, PDGFb and its receptor ; PDGFbr by RT-PCR.
Results : The mRNA level of VEGF was significantly increased in CDH+ GA 21 compared than CDH- GA21. No significant difference was observed in two group ; CDH+ GA21 and Control GA21 in mRNA level of VEGF. The mRNA level of FLK1 was no difference in three groups. In contrast, the mRNA level of Ang-1 was significantly decreased in CDH+ GA 21 compared than CDH- and control GA21. The mRNA of Ang-2 showed wide expression levels and no relation was not observed in each group. TIE2 mRNA level was no difference in three groups. Both of PDGFb and PDGFbr was no difference in three groups and in each GA.
Discussion : In the fetus of CDH rat, the mRNA of VEGF and Ang-1 showed different expression level in CDH+ GA21. This indicated that the vascular remodeling occurred by CDH during fetal periods. These changes of the remodeling factors were though to induce the regression of muscular layer of lung artery. Though, neonates with CDH showed the remarkable thickness of muscular layer of lung artery. PDGFb and PDGFbr was major factor for proliferation of smooth muscle of vessels. In our study, these mRNA level showed no difference in CDH+ and control group. According to these results, the other genes were supposed to induce hyper-proliferation of smooth muscle cells in CDH.