Involvement of n-3 PUFA-derived lipid mediators in the resolution of brain inflammation

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1 The 1 th Nutrition-Neuroscience meeting The 27 th of march 217 Involvement of n-3 PUFA-derived lipid mediators in the resolution of brain inflammation Charlotte Rey- PhD student

2 Acute inflammatory response Defensive physiological response that protects the host Infection cytokines, chemokines release BBB Controlled inflammation Homeostasis Peripheral immune cells activation Central microglia activation Uncontrolled inflammation Omega 6 N-6 PUFA Omega 3 N-3 PUFA PUFA Regulator of inflammatory processes Acute, chronic, systemic inflammatory disorders Failure of resolution?

3 Polyunsaturated fatty acids n-6 PUFA n-3 PUFA Linoleic acid (18:2) LA Alpha-linolenic acid (18:3) ALA Eicosapentaenoic acid (2:5) Arachidonic acid (2:4) AA EPA Docosahexaenoic acid (22:6) DHA Essential nutrients

4 % total fatty acids Polyunsaturated fatty acids n-6 PUFA n-3 PUFA % of PUFA in the hippocampus 1 3 Other The brain is highly enriched in PUFA : 35% of total fatty acids 2 1% DPA n-6 AA EPA % DHA Essential nutrients Key structural components of membrane in the brain

5 % total fatty acids Polyunsaturated fatty acids n-6 PUFA n-3 PUFA % of PUFA in the hippocampus 1 3 Other The brain is highly enriched in PUFA : 35% of total fatty acids 2 1% DPA n-6 AA EPA % DHA Essential nutrients Key components of membrane Regulation of brain development and cognition - Immunomodulatory effects

6 Polyunsaturated fatty acids n-6 PUFA n-3 PUFA Linoleic acid (18:2) LA Alpha-linolenic acid (18:3) ALA Arachidonic acid (2:4) CYP45 EETs LOX AA HETEs COX Prostaglandines Thromboxanes Mostly pro-inflammatory Docosahexaenoic acid (22:6) LOX DHA LOX NPD1 RvD1 Anti-inflammatory Mar1 «Oxylipins» : potent modulators of immune response produced endogenously

7 Acute inflammatory response Defensive physiological response that protects the host : role of PUFA-derived lipid mediators Infection cytokines, chemokines release BBB Controlled inflammation Homeostasis RvD1 Peripheral immune cells activation - - Neutrophils apoptosis - Efferocytosis - Decrease cytokine levels in macrophages? Central microglia activation Uncontrolled inflammation Acute, chronic, systemic inflammatory disorders Failure of resolution?

8 RvD1 prevents cognitive impairment (Terrando N 213 FASEB J) - RvD1 acute i.p. administration - Surgery-induced cognitive decline : Tibial fracture Quantification of astrogliosis in the hippocampus Contextual fear conditioning Hippocampal-dependant memory Surgery-induced reactive astrogliosis in the hippocampus is reversed by AT-RvD1 Surgery induce reduced freezing to the context RvD1 restored freezing behavior, the index for memory retention

9 RvD1 prevents cognitive impairment - RvD1 chronic peripheral administration - Traumatic brain injury (Harrison JL 215 BBI) Novel object recognition Surgery : mice spent similar times investigating both objects indicating no recall of the familiar object. RvD1 prevented TBI-induced cognitive impairment TBI Direct or indirect effect of RvD1 in the brain?

10 DHA and 17(S)-HpDHA decreases inflammation - DHA and 17S-HpDHA brain infusion - Acute brain injection (Orr et al. 213) DHA IL-1β expression in the hippocampus 15-LOX 17S-HpDHA 5-LOX RvD1 SPM : specialized pro-resolving mediators such as resolvins

11 RvD1 identification in the brain RvD1 identification in the hippocampus following transient ischemia (Marcheselli 23 JBC)

12 Is DHA-derived RvD1 directly involved in the resolution of brain inflammation? Cytokines release BBB Homeostasis Peripheral immune cells activation Central microglia activation? RvD1 Acute, chronic, systemic inflammatory disorders

13 Microglia cells culture BV2 cells 3 min 6h RvD1 (1nM) treatment (1µg/ml) treatment Cells collection Inflammatory response Pro-inflammatory response to IL-1 TNF Saline Saline Saline

14 Anti-inflammatory markers Pro-inflammatory markers RvD1 inhibits inflammation through ALX/frp2 Neuroinflammatory profile ALX/fpr2-dependant action Boc-2 antagonist decrease increasse IL-1 TNF- RvD1+ RvD1 receptor ALX/fpr2 CD86 CD26 inactivation SOCS3 Arg1 Ym # 2 Control + RvD1 + Boc2 + RvD1 + Boc2

15 HIGH EXPRESSION LOW EXPRESSION RvD1 potentiates mirna signature of resolution mirna signature of resolution of inflammation mirna : crucial role in the regulation of gene implicated in inflammation mir-32d mirna profile in response to and RvD1 treatment 1.5 mir mir-28a.5 ## mir-219. Control RvD1+ mir-142-5p mir-23 mir-21 mir-142-3p mir-146b mir-21 # mir-146 # Heat map cluster represents relative expression of mouse mirna from resolving exudates after zymosan Control RvD1+ Control RvD1+ (Adapted from Recchuitti and Serhan 212)

16 RvD1 signaling pathway CD14 17(S)-RvD1 TLR4 ALX/fpr2 P IkB-α NF-kB mirna NF-kB Pro-inflammatory genes Inflammation What is the impact of RvD1 in the brain on inflammation?

17 Brain infusion of DHA and RvD1 15-LOX DHA I.C.V. osmotic pump implantation 9 weeks acsf infusion DHA infusion (45µg) RvD1 infusion (1µg) 48h 48h 48h Brain collection Hippocampal analysis 17(S)-HpDHA I.P. injection 5µg/kg 2h 5-LOX RvD1

18 I.C.V. osmotic pump implantation Preliminary results Hippocampus mrna expression acsf infusion DHA infusion (45µg) RvD1 infusion (1µg) 48h 48h 48h I.P. injection 2h Inflammatory markers RvD1 synthesis pathway # COX2 COX-2 ## ### 15-LOX DHA LOX-15 LOX LCR-SAL LCR-SAL LCR- DHA- TNF-α TNF- RvD1- LCR- DHA- RvD1-. LCR-sal LCR-SAL LCR- DHA- RvD1- IL-1β IL-1 # LCR- DHA- RvD1-17(S)-HpDHA 5-LOX RvD LCR-sal LCR-sal LCR- DHA- LOX-5 LOX-5 RvD1- # LCR- DHA- RvD1-

19 I.C.V. osmotic pump implantation Preliminary results Hippocampus mrna expression acsf infusion DHA infusion (45µg) RvD1 infusion (1µg) 48h 48h 48h I.P. injection 2h Inflammatory markers RvD1 synthesis pathway # COX2 COX-2 ## ### 15-LOX DHA LOX-15 LOX LCR-SAL LCR-SAL LCR- DHA- TNF-α TNF- RvD1- LCR- DHA- RvD1-. LCR-sal LCR-SAL LCR- DHA- RvD1- IL-1β IL-1 # LCR- DHA- RvD1-17(S)-HpDHA 5-LOX RvD LCR-sal LCR-sal LCR- DHA- LOX-5 LOX-5 RvD1- # LCR- DHA- RvD1-

20 Inflammatory response Conclusion TNF-α IL-1β Arachidonic acid AA COX-2 P IkB-α NF-kB PG TX Pro-inflammatory genes, IL-1β, TNF-α, COX-2 COX-2 IL-1β TNF-α Neuroinflammation Oxidative stress

21 Conclusion Hypothetical DHA-derived RvD1 signaling pathway in the brain TNF-α IL-1β Docosahexaenoic acid DHA Arachidonic acid AA COX-2 P IkB-α NF-kB PG TX Pro-inflammatory genes, IL-1β, TNF-α, COX-2 COX-2 IL-1β TNF-α Neuroinflammation Oxidative stress

22 Conclusion Hypothetical DHA-derived RvD1 signaling pathway in the brain TNF-α IL-1β Docosahexaenoic acid DHA Arachidonic acid AA 15-LOX COX-2 P IkB-α NF-kB 5-LOX RvD1 + PG TX? Pro-inflammatory genes, IL-1β, TNF-α, COX-2 COX-2 IL-1β TNF-α Neuroinflammation Oxidative stress Indirect effect of RvD1 through PG and TX regulation Long term response?

23 X Conclusion Hypothetical DHA-derived RvD1 signaling pathway in the brain TNF-α IL-1β Docosahexaenoic acid DHA Arachidonic acid AA 15-LOX COX-2 P IkB-α NF-kB 5-LOX RvD1 PG TX Pro-inflammatory genes, IL-1β, TNF-α, COX-2 COX-2 IL-1β TNF-α Neuroinflammation Oxidative stress

24 Conclusion DHA is a potent regulator on brain inflammation DHA-derived RvD1 is involved in the resolution of brain inflammation Neuroinflammation Oxidative stress

25 Thank you Acknowledgment : Corinne Joffre; Sophie Layé; Carole Vaysse; Benjamin Buaud; Véronique Pallet; Agnès Nadjar; Guillaume Ferreira; Pierre Trifilieff; Pauline Lafenêtre; Agnès Aubert; Alexandra Sere; Anne-Laure Dinel; Véronique De Smedt Peyrusse; Clémentine Bosch-Bouju; Camille Kropp; Hélène Beuzelin; Célia Fourrier; Essi Biyong; Chloé Lacabanne; Anouk Benmamar; Quentin Leyrolle; Hortense Fanet; Fabien Ducrocq; Roman Walle