Public Defence: Markus Vicente Tørud Olsen

Cand.med. Markus Vicente Tørud Olsen at Institute of Clinical Medicine will be defending the thesis “The Pro-resolving Mediators Maresin 1, Maresin 2 and Annexin A1 in Maintenance of Ocular Surface Health” for the degree of PhD (Philosophiae Doctor).

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Photo: Madiha S. Khalid

Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.

Trial Lecture – time and place

See Trial Lecture.

Adjudication committee

  • First opponent: Professor Cintia S. De Paiva, Baylor College of Medicine, US
  • Second opponent: Professor Friedrich Paulsen, Friedrich Alexander University of Erlangen-Nuremberg, Germany
  • Third member and chair of the evaluation committee: Professor Knut Tomas Dalen, University of Oslo

Chair of the Defence

Professor Emeritus Trond Buanes, University of Oslo

Principal Supervisor

Professor Tor P. Utheim, University of Oslo

Summary

The omega-3 fatty acids Maresin 1 and Maresin 2 and the protein Annexin A1 are pro-resolving mediators which play an active role in resolution of inflammation. The mediators enhance elimination of apoptotic cells, activation of immune cells and limit invasion of leukocytes. The precursor of Maresin 1 and Maresin 2, the omega-3 fatty acid DHA, has been detected in tear fluid in individuals with chronic inflammation, indicating a role in resolution of ocular surface inflammation.

The aims of this thesis were to investigate the intracellular pathways used by Maresin 1, Maresin 2 and Annexin A1 in rat conjunctival goblet cells and to examine the effect of the mediators on mucin secretion. Furthermore, the influence of the mediators on the allergy associated compound histamine was investigated.

Rat conjunctival goblet cells were cultured. A ratio-imaging system using Fura-2/AM was used to measure changes in the peak of intracellular calcium in cytosol. An enzyme-linked lectin assay was used to measure changes in mucin secretion. In both calcium and mucin secretion experiments, the goblet cells were preincubated with inhibitors of different intracellular pathways before stimulation with either Maresin 1, Maresin 2 or Annexin A1. PCR was performed to explore if Annexin A1 was present in rat conjunctival goblet cells.

We found all the mediators to increase intracellular calcium levels in rat conjunctival goblet cells by activation of different receptors and intracellular pathways. Moreover, we found Annexin A1 to be present in rat conjunctival goblet cells. Furthermore, preincubation with the mediators blocked the effect of histamine, indicating a potential role as a future treatment in allergic conjunctivitis. We believe that these mediators stimulate ocular surface homeostasis, both in health and disease.

Additional information

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Published Nov. 24, 2022 12:18 PM - Last modified Dec. 7, 2022 10:23 AM