There is a great interest and unresolved paradox regarding the complex role of estrogen in immune and inflammatory responses. Sex-specific differences and estrogen's role in ocular inflammatory diseases are not well understood, even though Dry Eye Syndromes primarily affect women. Receptors for estrogens, ER? and ER?, are expressed in leukocytes and in every ocular tissue. Acute healthy inflammation depends on the early recruitment of neutrophils, their tightly controlled activation and subsequent removal by recruited macrophages. Dysregulation of this essential response likely represent the early event that triggers inflammatory and chronic diseases. The lipid mediator lipoxin A4 (LXA4) has been identified as key mediator of inflammatory resolution and regulators of leukocyte function. The cornea highly expresses a key enzyme for LXA4 formation, 15-lipoxygenase (15-LOX), and its G-protein coupled receptor ALX. Genetic disruption of the 15-LOX/LXA4 circuit leads to dysregulated inflammation, wound healing and pathological angiogenesis in the cornea. Preliminary studies demonstrate that female mice consistently exhibit delayed epithelial wound closure. A prospective clinical trial in 120 patients with corneal ulcers, documents for the first time, that epithelial wounds healed twice as slow in female patients. The female phenotype of delayed wound healing can be recapitulated by treating male mice with topical estrogen and in in vitro experiments with corneal epithelial cells. More importantly, ER? and ER? specific agonists differentially regulated inflammation, epithelial wound healing and the expression and activity of the intrinsic 15-LOX/LXA4 circuit. These findings correlate with lipidomic analysis from a dry eye model that demonstrates striking impairment in corneal 15-LOX activity in female mice. Estrogen's selective regulation of this intrinsic lipid circuit may provide novel insights into the etiology or pathogenesis of sex-specific ocular surface inflammatory diseases, which will be tested in three specific aims: I. Characterize sex-specific differences in the intrinsic 15-LOX and LXA4 circuit during acute and reoccurring epithelial injury and inflammation in the cornea. II. Elucidate the role of the estrogen receptors (ER? and ER?) in the regulation of corneal epithelial and leukocyte wound healing function and define receptor specific regulation of the 15-LOX and LXA4 circuit in these cells. III. Delineate the role ER? and ER? in the corneal pathogenesis of dry eye in mice and define the protective role of the intrinsic 15-LOX and LXA4 circuit. Result from this study will address critical gaps of knowledge regarding the role of estrogen and its receptors in acute inflammatory/reparative responses in the eye and will define for the first time sex-specific (estrogen) regulation of intrinsic lipid circuits that are critical for inflammatory resolution. Our knowledge of structure function relationships, receptors and signal transduction pathways for LXA4 and related mimetics is relatively advanced and efficacy/safety in animal models have been established. Hence, results from this study could rapidly bring novel treatment options for ocular surface inflammatory diseases to the clinic. !

Public Health Relevance

This study will address critical gaps of knowledge regarding the role of estrogen and its receptors in acute inflammatory/reparative responses in the eye and will define for the first time sex-specific (estrogen) regulation of intrinsic lipid circuits that are critical for inflammatory resolution. Due to the advanced pharmacology and clearly defined targets of endogenous protective lipid mediators, results from this study could rapidly bring novel treatment options for ocular surface inflammatory diseases to the clinic.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY022208-02
Application #
8463546
Study Section
Anterior Eye Disease Study Section (AED)
Program Officer
Mckie, George Ann
Project Start
2012-05-01
Project End
2016-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
2
Fiscal Year
2013
Total Cost
$357,323
Indirect Cost
$119,823
Name
University of California Berkeley
Department
Type
Schools of Optometry/Ophthalmol
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Gao, Yuan; Su, John; Zhang, Yibing et al. (2018) Dietary DHA amplifies LXA4 circuits in tissues and lymph node PMN and is protective in immune-driven dry eye disease. Mucosal Immunol 11:1674-1683
Pazos, Michael A; Lanter, Bernard B; Yonker, Lael M et al. (2017) Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration. PLoS Pathog 13:e1006548
Deguine, Jacques; Wei, Jessica; Barbalat, Roman et al. (2017) Local TNFR1 Signaling Licenses Murine Neutrophils for Increased TLR-Dependent Cytokine and Eicosanoid Production. J Immunol 198:2865-2875
Wei, Jessica; Gronert, Karsten (2017) The role of pro-resolving lipid mediators in ocular diseases. Mol Aspects Med 58:37-43
Rauch, Isabella; Deets, Katherine A; Ji, Daisy X et al. (2017) NAIP-NLRC4 Inflammasomes Coordinate Intestinal Epithelial Cell Expulsion with Eicosanoid and IL-18 Release via Activation of Caspase-1 and -8. Immunity 46:649-659
Walter, Scott D; Gronert, Karsten; McClellan, Allison L et al. (2016) ?-3 Tear Film Lipids Correlate With Clinical Measures of Dry Eye. Invest Ophthalmol Vis Sci 57:2472-8
Mozurkewich, Ellen L; Greenwood, Matthew; Clinton, Chelsea et al. (2016) Pathway Markers for Pro-resolving Lipid Mediators in Maternal and Umbilical Cord Blood: A Secondary Analysis of the Mothers, Omega-3, and Mental Health Study. Front Pharmacol 7:274
Gao, Yuan; Min, Kyungji; Zhang, Yibing et al. (2015) Female-Specific Downregulation of Tissue Polymorphonuclear Neutrophils Drives Impaired Regulatory T Cell and Amplified Effector T Cell Responses in Autoimmune Dry Eye Disease. J Immunol 195:3086-99
Pazos, Michael A; Pirzai, Waheed; Yonker, Lael M et al. (2015) Distinct cellular sources of hepoxilin A3 and leukotriene B4 are used to coordinate bacterial-induced neutrophil transepithelial migration. J Immunol 194:1304-15
Kalish, Brian T; Le, Hau D; Fitzgerald, Jonathan M et al. (2013) Intravenous fish oil lipid emulsion promotes a shift toward anti-inflammatory proresolving lipid mediators. Am J Physiol Gastrointest Liver Physiol 305:G818-28

Showing the most recent 10 out of 16 publications