Targeting Peroxisome Proliferator-Activated Receptor-α (PPAR- α) to reduce paclitaxel-induced peripheral neuropathy

Abstract

Background and purpose: Paclitaxel, a widely used anti-cancer drug, is frequently associated with prolonged and severe peripheral neuropathies (PIPN), associated with neuroinflammation. Currently, PIPN effective treatments are lacking. Peroxisome Proliferator-Activated Receptor-α (PPAR-⍺) can modulate inflammatory responses. Thus, the use of PPAR-⍺ agonists, such as fibrates (fenofibrate and choline-fenofibrate), currently used in dyslipidemia treatment, could represent an interesting therapeutic approach in PIPN.

Experimental approach: Our studies tested the efficacy of fenofibrate (150 mg/kg, daily, i.p.) and choline fenofibrate (60 mg/kg daily, p.o.) in reversing and preventing the development of PIPN (paclitaxel: 8 mg/kg, i.p., every other day for 4 days) in male and female C57BL/6J mice. Mechanical and cold hypersensitivity, conditioned place preference, sensory nerve action potential (SNAP), as well as the expression of PPAR-⍺, TNF-⍺, IL-1β and IL-6 mRNA were evaluated.

Key results: While fenofibrate treatment partially reversed and prevented the development of mechanical hypersensitivity, this was completely reversed and prevented by choline-fenofibrate. Both fibrates were able to completely reverse and prevent cold hypersensitivity induced by paclitaxel. The reduction of SNAP amplitude induced by paclitaxel was also reversed by both fenofibrate and choline-fenofibrate. Our results indicate that suppression of paclitaxel-induced hypersensitivity by fibrates involves the regulation of PPAR-⍺ expression and decrease neuroinflammation in DRG. Finally, the co-treatment of Paclitaxel and fenofibric acid (fibrates active metabolite) was tested on different cancer cell lines, no decrease in the antitumoral effect of paclitaxel was observed.

Conclusions and implications: Taken together, our results show for the first time the therapeutic potential (prevention and reversal) of fibrates in PIPN and opens to a potential pharmacological repurposing of these drugs.

Keywords: Chemotherapy; Fibrates; Neuroinflammation; PPAR-⍺; Peripheral neuropathy.

Conflict of interest statement

Conflict of interest disclosures: No conflict of interest was declared.

Copyright © 2021 Elsevier Inc. All rights reserved.

Figures

Figure 1:. PPAR-α mRNA expression in DRG and spinal after paclitaxel injection.

PPAR-α mRNA expression were measured at day 7, 14, 21 and 28 after paclitaxel injection in DRG (A, B, C and D) and spinal cord (E, F, G and H). Values are expressed as mean ± SEM. n= 10/group. Results were compared using t-test (*: p

Figure 2:. Reduction of mechanical and cold hypersensitivity induce by paclitaxel with a single i.p. injection of fenofibrate, fenofibric acid or choline-fenofibrate.

Mechanical hypersensitivity was tested at D14 after the first injection of paclitaxel with the von Frey test. After a single i.p. injection of fenofibrate (50, 100 or 150mg/kg) (A), fenofibric acid (6, 12 or 24mg/kg) (B) and choline-fenofibrate (6, 12 or 24mg/kg) (C) mice was tested at different time point: 0h, 1h, 2h, 4h, 6h and 8h. Cold hypersensitivity was tested at D15 after the first injection of paclitaxel with the acetone test. After a single injection of fenofibrate (150mg/kg) (D), fenofibric acid (24mg/kg) (E) and choline-fenofibrate (24mg/kg) (F) mice was tested one time at 4h (fenofibrate) and 2h (fenofibric acid and choline-fenofibrate). Values are expressed as mean ± SEM. n= 8/group. Results were compared using two-way ANOVA (A,B and C) and one-way ANOVA (D, E and F) and post-hoc Tukey’s test (*: p

Figure 3:. Reduction of mechanical and cold hypersensitivity induce by paclitaxel with a single p.o. administration of fenofibrate, fenofibric acid or choline-fenofibrate.

Mechanical hypersensitivity was tested at D14 after the first injection of paclitaxel with the von Frey test. After a single p.o. administration of fenofibrate (150, 300 or 600mg/kg) (A), fenofibric acid (30, 60 or 90mg/kg) (B) and choline-fenofibrate (15, 30 or 60mg/kg) (C) mice was tested at different time point: 0h, 1h, 2h, 4h, 6h and 8h. Cold hypersensitivity was tested at D15 after the first injection of paclitaxel with the acetone test. After a single administration of fenofibrate (300mg/kg) (D), fenofibric acid (90mg/kg) (E) and choline-fenofibrate (60mg/kg) (F) mice was tested one time at 4h (fenofibrate) and 2h (fenofibric acid and choline-fenofibrate). Values are expressed as mean ± SEM. n= 8/group. Results were compared using two-way ANOVA (A,B and C) and one-way ANOVA (D, E and F) and post-hoc Tukey’s test (*: p

Figure 4:. Fenofibrate and choline-fenofibrate reduce paclitaxel-induced mechanical hypersensitivity by PPAR-α activation.

Mechanical hypersensitivity was tested at D14 after the first injection of paclitaxel with the von Frey test. (A) Fenofibrate treatment i.p. injection 150mg/kg and/or MK886: PPAR-α antagonist. (B) Choline-fenofibrate treatment p.o. administration 60mg/kg and/or MK886: PPAR-α antagonist. Values are expressed as mean ± SEM. n= 8/group. Results were compared using one-way ANOVA and post-hoc Tukey’s test (*: p

Figure 5:. Fenofibrate and choline-fenofibrate reduce paclitaxel-induced neuropathic pain.

(A) Conditioned place preference test on mice treated with fenofibrate (i.p. 150mg/kg). (B) Conditioned place preference test on mice treated with choline-fenofibrate (p.o. 60mg/kg). Values are expressed as mean ± SEM (n= 12/group). Results were compared using one-way ANOVA and post-hoc Tukey’s test (*: p

Figure 6:. Reversal of PIPN signs with a repeated treatment of fenofibrate (i.p.) and choline-fenofibrate (p.o.).

Mice were treated with fenofibrate (i.p., 150mg/kg) or choline-fenofibrate (p.o., 60mg/kg) for one week (Day 14 to D21 after paclitaxel). Mechanical (A and E) and cold (B and F) hypersensitivity were tested at D21 after the first injection of paclitaxel with the von Frey and acetone tests respectively. Sensory nerve compound action potential amplitude was measured at D22 (C and G). Fenofibric acid was quantified in plasma after fenofibrate (D) and choline-fenofibrate (H) administration. Values are expressed as mean ± SEM. n= 12/group. Results were compared using two-way ANOVA (A and E) and one-way ANOVA (B, C, F and G) and post-hoc Tukey’s test (*: p

Figure 7:. PPAR-α mRNA expression and inflammatory markers mRNA (TNF-α, IL-1β and IL-6) in DRG and spinal 23 days after paclitaxel injection.

PPAR-α mRNA expression was measured at day 23 after paclitaxel injection in DRG (A) and spinal cord (E). TNF-α mRNA expression was measured at day 23 after paclitaxel injection in DRG (B) and spinal cord (F). IL-1β mRNA expression was measured at day 23 after paclitaxel injection in DRG (C) and spinal cord (G). IL-6 mRNA expression was measured at day 23 after paclitaxel injection in DRG (D) and spinal cord (H). Values are expressed as mean ± SEM. n= 12/group. Results were compared using one-way ANOVA and post-hoc Tukey’s test (*: p

Figure 8:. Prevention of PIPN signs with a repeated treatment of fenofibrate (i.p.) and choline-fenofibrate (p.o.).

Mice were treated with fenofibrate (i.p., 150mg/kg) or choline-fenofibrate (p.o., 60mg/kg) for 10 days (before, during and after paclitaxel). (A and E) Mechanical and cold (B and F) hypersensitivity were tested at BL, D7, D10, D14, D21 and D28 with the von Frey and acetone tests respectively. Sensory nerve compound action potential amplitude was measured at D21 (C and G). Sensory nerve conduction velocity was measured at D21 (D and H). Values are expressed as mean ± SEM. n= 8/group. Results were compared using two-way ANOVA (A, B, E and F) and one-way ANOVA (C, D, G and H) and post-hoc Tukey’s test (*: p

Figure 9:. Fenofibric acid did not alter paclitaxel-induced cytotoxicity in lung or breast tumor cells.

(A) Cell Viability H460 and A5649 non-small cell lung cancer cells and MCF-7 breast cancer cells were exposed to fenofibric acid (FA, 20 μM), paclitaxel (PAC, 50 nM), and a combination of fenofibric acid and paclitaxel (FA+PAC) for 24 hours (CTL=Control). The number of viable cells was monitored over 7 days via Trypan blue exclusion. ** p