Aparna Mahajan1, Lenka Hasíková2, Ulrike Hampel3, Anika Grüneboom1, Xiaomei Shan1, Irmgard Herrmann1, Fabian Garreis4, Felix Bock5, Jasmin Knopf1, Jeeshan Singh1, Christine Schauer1, Siddharth Mahajan6, Moritz Leppkes7, Friedrich Paulsen4, Ursula Schlötzer-Schrehardt6, Veit Krenn8, Anselm Jünemann9, Bettina Hohberger6, Georg Schett1, Martin Herrmann1, Luis E Muñoz10. 1. Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany. 2. Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany; Department of Rheumatology, First Faculty of Medicine, Charles University-Institute of Rheumatology Prague, Czech Republic. 3. Department of Ophthalmology, University Medical Center, Johannes Gutenberg University, Mainz, Germany. 4. Department of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany. 5. Department of Ophthalmology, University of Cologne, Cologne, Germany. 6. Department of Ophthalmology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) Universitätsklinikum Erlangen, Erlangen, Germany. 7. Department of Medicine 1, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany. 8. MVZ für Pathologie-GmbH, Trier, Germany. 9. Department of General Ophthalmology, Medical University of Lublin, Poland. 10. Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany. Electronic address: luis.munoz@uk-erlangen.de.
Abstract
PURPOSE: Obstructive Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease. Meibomian glands at the eyelid secrete lipids that prevent evaporation of the aqueous tear film. The pathogenesis of obstructive MGD is incompletely understood to date. Herein, we aim to investigate the pathogenesis of obstructive MGD using murine and human samples with various forms of ocular surface inflammation. METHOD: The presence of Neutrophil extracellular Traps (NETs) was detected with immunofluorescence analysis of ocular surface discharge and biopsy samples from patients with blepharitis. Tear fluid from patients with MGD and blepharitis were evaluated for the presence of inflammatory mediators using bead based immunoassay. Murine model of allergic eye disease (AED) was performed to investigate the role of NETs in MG occlusion. RESULTS: we show that the ocular discharge from patients with blepharitis contains aggregated neutrophil extracellular traps (aggNETs). Furthermore, the ducts of human Meibomian glands affected by blepharitis were largely congested by aggNETs. Tear fluid from patients with MGD showed elevated neutrophil chemoattractants (C5a, IL6, IL8 and IL18). C5a and IL8 correlated with the degree of deficiency of tear fluid. In the murine model of allergic eye disease (AED), aggNETs accumulated in the MG leading to occlusion of their ducts and the retrograde pent-up of the fluid followed by acinar atrophy. Constraining aggNET formation by genetic or pharmacological inhibition of peptidyl arginine deiminase type 4 (PADI4) effectively reduced MG damage. CONCLUSION: We conclude that aggNETs occlude MG causing MGD after ocular surface inflammation.
PURPOSE: Obstructive Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease. Meibomian glands at the eyelid secrete lipids that prevent evaporation of the aqueous tear film. The pathogenesis of obstructive MGD is incompletely understood to date. Herein, we aim to investigate the pathogenesis of obstructive MGD using murine and human samples with various forms of ocular surface inflammation. METHOD: The presence of Neutrophil extracellular Traps (NETs) was detected with immunofluorescence analysis of ocular surface discharge and biopsy samples from patients with blepharitis. Tear fluid from patients with MGD and blepharitis were evaluated for the presence of inflammatory mediators using bead based immunoassay. Murine model of allergic eye disease (AED) was performed to investigate the role of NETs in MG occlusion. RESULTS: we show that the ocular discharge from patients with blepharitis contains aggregated neutrophil extracellular traps (aggNETs). Furthermore, the ducts of human Meibomian glands affected by blepharitis were largely congested by aggNETs. Tear fluid from patients with MGD showed elevated neutrophil chemoattractants (C5a, IL6, IL8 and IL18). C5a and IL8 correlated with the degree of deficiency of tear fluid. In the murine model of allergic eye disease (AED), aggNETs accumulated in the MG leading to occlusion of their ducts and the retrograde pent-up of the fluid followed by acinar atrophy. Constraining aggNET formation by genetic or pharmacological inhibition of peptidyl arginine deiminase type 4 (PADI4) effectively reduced MG damage. CONCLUSION: We conclude that aggNETs occlude MG causing MGD after ocular surface inflammation.
Authors: Maximilian Dölling; Markus Eckstein; Jeeshan Singh; Christine Schauer; Janina Schoen; Xiaomei Shan; Aline Bozec; Jasmin Knopf; Georg Schett; Luis E Muñoz; Martin Herrmann Journal: Front Immunol Date: 2022-02-11 Impact factor: 7.561
Authors: Ching Yi Wu; Mengliang Wu; Xin Huang; Ben J Gu; Carole Maldonado-Codina; Philip B Morgan; Laura E Downie; Holly R Chinnery Journal: Int J Mol Sci Date: 2022-08-24 Impact factor: 6.208