Imbalance of caveolin-1 and eNOS expression in the pulmonary vasculature of experimental diaphragmatic hernia.

Abstract

BACKGROUND:

Caveolin-1 (Cav-1) exerts major regulatory functions on intracellular signaling pathways originating at the plasma membrane. Cav-1 is a key regulator in adverse lung remodeling and the development of pulmonary hypertension (PH) regulating vasomotor tone through its ability to reduce nitric oxide (NO) production. This low-output endothelial NO synthase (eNOS) derived NO maintains normal pulmonary vascular homeostasis. Cav-1 deficiency leads to increased bioavailability of NO, which has been linked to increased nitrosative stress. Inhibition of eNOS reduced oxidant production and reversed PH, supporting the concept that Cav-1 regulation of eNOS activity is crucial to endothelial homeostasis in lungs. We designed this study to investigate the hypothesis that expression of Cav-1 is downregulated while eNOS expression is upregulated by the pulmonary endothelium in the nitrofen-induced congenital diaphragmatic hernia (CDH).

METHODS:

Pregnant rats were exposed to nitrofen or vehicle on day 9.5 (D9.5). Fetuses were sacrificed on D21 and divided into nitrofen and control groups. Quantitative real-time polymerase chain reaction, Western blotting, and confocal immunofluorescence were performed to determine pulmonary gene expression levels and protein expression of Cav-1 and eNOS.

RESULTS:

Pulmonary Cav-1 gene expression levels were significantly decreased, while eNOS gene expression was significantly increased in nitrofen-induced CDH(+). Western blotting and confocal microscopy revealed decreased pulmonary Cav-1 protein expression, while eNOS protein expression was increased in CDH(+) compared to controls.

CONCLUSION:

The striking evidence of markedly decreased gene and protein expression of Cav-1 with concurrently increased eNOS gene and protein expression in the pulmonary vasculature suggests that activation of eNOS secondary to Cav-1 deficiency may play an important role in the pathogenesis of PH in the nitrofen-induced CDH.

• Authors: Alejandro Hofmann, Jan-Hendrik Gosemann, Toshiaki Takahashi, Florian Friedmacher, Johannes W Duess, Prem Puri
• Journal: Birth defects research. Part B, Developmental and reproductive toxicology (Birth Defects Res B Dev Reprod Toxicol) Vol. 101 Issue 4 Pg. 341-6 (Aug 2014) ISSN: 1542-9741 [Electronic] United States
• PMID: 25078423 (Publication Type: Journal Article)
• Copyright: © 2014 Wiley Periodicals, Inc.

Chemical References

• Caveolin 1
• Herbicides
• Phenyl Ethers
• Nitric Oxide
• Nitric Oxide Synthase Type III
• Nos3 protein, rat
• nitrofen

Topics

• Abnormalities, Multiple (chemically induced)
• Animals
• Caveolin 1 (biosynthesis)
• Down-Regulation
• Enzyme Activation (genetics)
• Female
• Gene Expression (drug effects)
• Gene Expression Regulation, Developmental
• Herbicides (pharmacology)
• Hernias, Diaphragmatic, Congenital (chemically induced, genetics)
• Hypertension, Pulmonary (chemically induced)
• Lung (abnormalities, blood supply, metabolism)
• Lung Diseases (chemically induced)
• Nitric Oxide (metabolism)
• Nitric Oxide Synthase Type III (biosynthesis, metabolism)
• Phenyl Ethers (pharmacology)
• Pregnancy
• Rats
• Rats, Sprague-Dawley
• Signal Transduction
• Up-Regulation