Background: Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation.

Methods: Wild-type (WT), Notch3 ( Notch3^–/– ), and Notch4 ( Notch4^–/– ) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6–72 hr.

Results: Relative to air-exposed controls, ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4^–/– compared with WT and Notch3^–/– mice. Significantly greater mean numbers of BALF neutrophils were found in Notch3^–/– and Notch4^–/– mice compared with WT mice after ozone exposure. Expression of whole lung Tnf was significantly increased after ozone in Notch3^–/– and Notch4^–/– mice, and was significantly greater in Notch3^–/– compared with WT mice. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30 , a member of the inflammasome pathway, and Traf6 , an inflammatory signaling member.

Conclusions: These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation.

Citation: Verhein KC, McCaw Z, Gladwell W, Trivedi S, Bushel PR, Kleeberger SR. 2015. Novel roles for Notch3 and Notch4 receptors in gene expression and susceptibility to ozone-induced lung inflammation in mice. Environ Health Perspect 123:799–805;  http://dx.doi.org/10.1289/ehp.1408852

Address correspondence to K.C. Verhein, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, 111 T.W. Alexander Dr., Building 101, MD D-201, Research Triangle Park, NC 27709 USA. Telephone: (919) 316-4673. E-mail: kirsten.verhein@nih.gov

We thank the NIEHS Microarray Core (K. Gerrish, R. Fannin, and L. Wharey), the NIEHS Histology Core (G. Flake) for assistance with lung pathology, and J. Williams of the NIEHS Mass Spectrometry Group. We thank Alion Science and Technology for performing ozone exposures. We also thank D. Cook and M. Fessler for critical review of the manuscript.

Research was supported by the Intramural Research Program of NIEHS, NIH, DHHS.

The authors declare they have no actual or potential competing financial interests.

Received: 20 June 2014 Accepted: 5 February 2015 Advance Publication: 6 February 2015 Final Publication: 1 August 2015