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Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice.

Verhein KC, McCaw Z, Gladwell W, Trivedi S, Bushel PR, Kleeberger SR - Environ. Health Perspect. (2015)

Bottom Line: We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation.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.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.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Resources (DHHS), Research Triangle Park, North Carolina, USA.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus

Real-time PCR of whole-lung homogenates for Notch receptors, ligands, and target genes. (A) Notch1. (B) Notch2. (C) Notch3. (D) Notch4. (E) Jag1. (F) Jag2. (G) Hes1. (H) Dll1. Expression of Notch1 and Notch2 decreased in Notch3–/– and Notch4–/– mice after 48 hr exposure to ozone. n = 3–10 mice per group (exposed in 2–3 groups).*p < 0.05 compared with respective air controls, by 2-way ANOVA with Bonferroni post hoc tests.
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f2: Real-time PCR of whole-lung homogenates for Notch receptors, ligands, and target genes. (A) Notch1. (B) Notch2. (C) Notch3. (D) Notch4. (E) Jag1. (F) Jag2. (G) Hes1. (H) Dll1. Expression of Notch1 and Notch2 decreased in Notch3–/– and Notch4–/– mice after 48 hr exposure to ozone. n = 3–10 mice per group (exposed in 2–3 groups).*p < 0.05 compared with respective air controls, by 2-way ANOVA with Bonferroni post hoc tests.

Mentions: Although significantly increased compared with air controls, inflammation parameters (BALF protein and total cells) in WT mice were minimal after ozone exposure (Figure 1A,B) compared with more susceptible strains (Cho et al. 2001). Relative to air-exposed controls, deletion of either Notch3 or Notch4 markedly enhanced ozone-induced increases in the numbers of macrophages and monocytes in BALF (Figure 1D,E; see also Supplemental Material, Table S1) and whole-lung expression of proinflammatory mediators Tnf and Cxcl2 (macrophage inflammatory protein 2-alpha; Mip2) (Figure 1H,I). Lymphocytes in BALF were not consistently changed by ozone exposure; a significant increase was found only after 24-hr ozone exposure in WT mice (Figure 1G). We also measured an increase in NF-κB activation after 48-hr ozone in Notch4–/– mice (Figure 1J). Neither Notch3 nor Notch4 were expressed in animals with their respective deletion (Figure 2C,D), and we found no ozone or genotype effect on known Notch ligands (Jagged1, Jagged2, and Dll1) or the effector molecule Hes1 (Figure 2E–H).


Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice.

Verhein KC, McCaw Z, Gladwell W, Trivedi S, Bushel PR, Kleeberger SR - Environ. Health Perspect. (2015)

Real-time PCR of whole-lung homogenates for Notch receptors, ligands, and target genes. (A) Notch1. (B) Notch2. (C) Notch3. (D) Notch4. (E) Jag1. (F) Jag2. (G) Hes1. (H) Dll1. Expression of Notch1 and Notch2 decreased in Notch3–/– and Notch4–/– mice after 48 hr exposure to ozone. n = 3–10 mice per group (exposed in 2–3 groups).*p < 0.05 compared with respective air controls, by 2-way ANOVA with Bonferroni post hoc tests.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4529014&req=5

f2: Real-time PCR of whole-lung homogenates for Notch receptors, ligands, and target genes. (A) Notch1. (B) Notch2. (C) Notch3. (D) Notch4. (E) Jag1. (F) Jag2. (G) Hes1. (H) Dll1. Expression of Notch1 and Notch2 decreased in Notch3–/– and Notch4–/– mice after 48 hr exposure to ozone. n = 3–10 mice per group (exposed in 2–3 groups).*p < 0.05 compared with respective air controls, by 2-way ANOVA with Bonferroni post hoc tests.
Mentions: Although significantly increased compared with air controls, inflammation parameters (BALF protein and total cells) in WT mice were minimal after ozone exposure (Figure 1A,B) compared with more susceptible strains (Cho et al. 2001). Relative to air-exposed controls, deletion of either Notch3 or Notch4 markedly enhanced ozone-induced increases in the numbers of macrophages and monocytes in BALF (Figure 1D,E; see also Supplemental Material, Table S1) and whole-lung expression of proinflammatory mediators Tnf and Cxcl2 (macrophage inflammatory protein 2-alpha; Mip2) (Figure 1H,I). Lymphocytes in BALF were not consistently changed by ozone exposure; a significant increase was found only after 24-hr ozone exposure in WT mice (Figure 1G). We also measured an increase in NF-κB activation after 48-hr ozone in Notch4–/– mice (Figure 1J). Neither Notch3 nor Notch4 were expressed in animals with their respective deletion (Figure 2C,D), and we found no ozone or genotype effect on known Notch ligands (Jagged1, Jagged2, and Dll1) or the effector molecule Hes1 (Figure 2E–H).

Bottom Line: We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation.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.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.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Resources (DHHS), Research Triangle Park, North Carolina, USA.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus