The (patho)physiological role(s) of CYP450-mediated mechanism(s) in the ophthalmic artery
Final Report Abstract
This project elucidated the (patho)physiological roles of cytochrome P450 (CYP)-mediated mechanisms when exposed to glaucoma-related risk factors, namely aging, sex and oxidative stress, in the ophthalmic artery. We provided the first experimental evidence that the CYP- derived eicosanoids comprising epoxyeicosatrienoic acids (EETs) behave as vasoconstrictors in the ophthalmic artery. Next, we demonstrated that dietary supplementation with omega-3 polyunsaturated fatty acids (ω-3) elicited profound changes in the proteome of the ophthalmic artery within just 7 days by regulating distinct vasoprotective mechanisms to preserve the functionality and integrity of the ophthalmic artery in Cyp-gene deleted mice. We also demonstrated that an acute exposure to angiotensin II (Ang II)-induced oxidative stress significantly affected actin cytoskeleton remodelling as inherent adaptation mechanism of the ophthalmic artery to maintain vascular homeostasis. In addition, we tested and proved the hypothesis that the retina is more susceptible to Ang II-elicited oxidative insult than the ophthalmic artery as demonstrated by cellular bioenergetics shift in the former tissue. The first glimpse into the novel signalling axis and proteome changes in both ocular vasculatures to better understand the impact of oxidative stress in glaucoma has garnered wide media attention at various platforms including publications in Redox Biology and ‘der Augenspiegel’, press release, and the Roland Britz Glaucoma Award 2021. We have previously identified the functional role and expression of the voltage-gated potassium ion channel Kv1.6 in the ophthalmic artery. Here, we expanded our investigation to enrich and characterize the interactome of Kv1.6 for the first time. Although Kv1.6 is known to be the most widespread K+ channel subtype in the nervous system, its physiological and functional significance remains largely unknown compared to other Kv1 channels. Therefore, our data serve as an important basis for future studies of this channel subtype. Finally, we deciphered the distinct proteome and cell signalling alterations associated with aging and sex when the EET-metabolizing enzyme, soluble epoxide hydrolase (sEH), is chronically lacking using mice with targeted deletion of the Ephx2 gene. The absence of sEH ameliorated certain age-related deleterious cellular mechanisms, and there were specific sex-related changes, which collectively underscores the vasoprotective role of sEH inhibition in this vasculature. In gist, we have provided a comprehensive insight into the CYP-mediated cell signalling profiles of the ophthalmic artery, as well as furnished vital missing links attributed to compensatory mechanisms in response to various pathophysiological insults, which will be instrumental for future translational efforts in improving ocular perfusion in glaucoma.
Publications
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Angiotensin II-Induced Oxidative Stress Inactivates Neuroprotective Mechanisms in Retina and Heightens Acute Vascular Adaptive Responses in Ophthalmic Artery: A Proteomic Perspective. Investigative Ophthalmology & Visual Science 60 (9), 5653. (This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada; April 28 – May 2, 2019).
Caroline Manicam, Lars Straßburger, David Herzog, Norbert Pfeiffer, Franz H. Grus & Natarajan Perumal
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Sample Preparation for Mass-spectrometry-based Proteomics Analysis of Ocular Microvessels. Journal of Visualized Experiments, (144).
Perumal, Natarajan; Straßburger, Lars; Schmelter, Carsten; Gericke, Adrian; Pfeiffer, Norbert; Grus, Franz H. & Manicam, Caroline
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Bioenergetic shift and actin cytoskeleton remodelling as acute vascular adaptive mechanisms to angiotensin II in murine retina and ophthalmic artery. Redox Biology, 34, 101597.
Perumal, Natarajan; Straßburger, Lars; Herzog, David P.; Müller, Marianne B.; Pfeiffer, Norbert; Grus, Franz H. & Manicam, Caroline
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Cyp2c44 epoxygenase-derived epoxyeicosatrienoic acids in vascular smooth muscle cells elicit vasoconstriction of the murine ophthalmic artery. Scientific Reports, 11(1).
Hu, Jiong; Sisignano, Marco; Brecht, Roman; Perumal, Natarajan; Angioni, Carlo; Bibli, Iris-Sofia; Fisslthaler, Beate; Kleinert, Hartmut; Pfeiffer, Norbert; Fleming, Ingrid & Manicam, Caroline
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Acute Dietary Supplementation with Omega-3 Fatty Acid Confers Novel Mechanistic Changes in Retinal Proteome in Mice with Targeted Gene Deletion of Cytochrome P450. Investigative Ophthalmology & Visual Science 63 (7), 2710-A0074. (This abstract was presented at the 2022 Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting, held in Denver, CO,USA; May 1-4, 2022).
Manicam, C., Herfurth, A., Grus, F., Pfeiffer, N. & Perumal, N.
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Acute omega‐3 fatty acid supplementation confers novel neurovascular‐protective effects on the retinal and ophthalmic arterial proteome of Cyp2c44−/− mice. Acta Ophthalmologica, 100(S275).
Manicam, Caroline; Herfurth, Anna; Grus, Franz; Pfeiffer, Norbert & Perumal, Natarajan
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Short-Term Omega-3 Supplementation Modulates Novel Neurovascular and Fatty Acid Metabolic Proteome Changes in the Retina and Ophthalmic Artery of Mice with Targeted Cyp2c44 Gene Deletion. Cells, 11(21), 3494.
Perumal, Natarajan; Herfurth, Anna; Pfeiffer, Norbert & Manicam, Caroline
