N‑linoleyltyrosine protects PC12 cells against oxidative damage via autophagy: Possible�involvement of CB1 receptor regulation

Abstract

Oxidative stress is one of the main pathogenic factors of neurodegenerative diseases. As the ligand of cannabinoid type 1 (cB1) and 2 (cB2) receptors, anandamide (AEA) exerts benign antioxidant activities. However, the instability of AEA results in low levels in vivo, which limit its further application. Based on the structure of AEA, N-linoleyltyrosine (NITyr) was synthesized in our laboratory and was hypothesized to possess a similar function to that of AEA. To the best of our knowledge, the present study demonstrates for the first time, the activities and mechanisms of NITyr. NITyr treatment attenuated hydrogen peroxide (H 2 O 2)-induced cytotoxicity, with the most promiment effect observed at 1 µmol/l. Treatment with NITyr also suppressed the H 2 O 2-induced elevation of reactive oxygen species (ROS) and enhanced the expression of the autophagy-related proteins, Lc3-II, beclin-1, ATG 5 and ATG13. The autophagic inhibitor, 3-methyladenine, reversed the effects of NITyr on ROS levels and cellular viability. Furthermore, AM251, a cB1 receptor antagonist, but not AM630 (a cB2 receptor antagonist), diminished the effects of NITyr on cell viability, ROS generation and autophagy-related protein expression. However, NITyr increased the protein expression of both the cB1 and cB2 receptors. Therefore, NITyr was concluded to protect Pc12 cells against H 2 O 2-induced oxidative injury by inducing autophagy, a process which may involve the cB1 receptor.

Intracellular Molecular Targets and Signaling Pathways Involved in Antioxidative and Neuroprotective Effects of Cannabinoids in Neurodegenerative Conditions

“…Via CB1 receptors, NITyr attenuated H 2 O 2 -induced neurotoxic effects, reduced ROS generation, and induced autophagy by stimulating the expression of autophagy-related proteins. As the autophagy inhibitor attenuated the effects of NITyr on ROS levels and cell survival, it is likely that the observed antioxidative effects were mediated by autophagy and that the CB1 receptor-mediated induction of autophagy may be a promising neuroprotective approach in future pharmacological strategies [ 185 ]. This compound also demonstrated neuroprotective effects in primary cortical neurons.…”

N-linoleyltyrosine ameliorates high-fat diet-induced obesity in C57BL/6 mice via cannabinoid receptor regulation

“…NITyr was independently synthesized in our laboratory according to the literature ( 12 ), Orlistat (MACKLIN, purity: 98%, CAS: 96829-58-2), Poloxamer 188 (Solarbio, CAS: 9003-11-6), 45% kcal high-fat diet (MD12032, Medicine, Jiangsu, China; protein 24%, fat 24% and carbohydrate 41%), RIPA lysis Buffer (Strong) (Cwbio, CW2333), SDS-PAGE Loading Buffer (Cwcio, CW0027S, 5 ×), Protease inhibitor cocktail (Cwbio, CW22005, 100 ×), Phosphatase inhibitor cocktail (Cwbio, CW2383S, 100 ×), CNR1 Ab - DF4918 (Source: Rabbit, Cat. #: DF4918, Affinity Biosciences), CNR2 Ab - DF8646 (Source: Rabbit, Cat.…”

“…N-linoleoyltyrosine (NITyr), an endocannabinoid analog, exerts neuroprotective effects in APP/PS1 transgenic mice, protects against transient cerebral ischemia in gerbils, and protects PC12 cells against oxidative damage via mediating cannabinoid receptors (CB 1 and CB 2 ) as a neuroprotective agent in vitro ( 10 – 12 ). CB 1 and CB 2 are potential therapeutic targets for obesity ( 13 – 15 ).…”

The Biosynthesis and Metabolism of the N-Acylated Aromatic Amino Acids: N-Acylphenylalanine, N-Acyltyrosine, N-Acyltryptophan, and N-Acylhistidine

“…Long-chain N -acylated L-phenylalanines, N -palmitoyl, N -oleoyl, and N -linoleoyl, are uncouplers of the uncoupling protein 1 (UPC1)-independent respiration in mitochondria and may contribute to the regulation of glucose homoeostasis ( Long et al, 2016 ). Other cellular functions attributed to NA-ArAAs in mammals include the antiproliferative effects of N -palmitoyl-L-tyrosine against cultured human breast cancer cells ( Burstein and Salmonsen, 2008 ) and the neuroprotective effects of N -stearoyl-L-tyrosine and N -linoleoyl-L-tyrosine ( Zhang et al, 2009 ; Liu et al, 2020b ). The cellular activities of the NA-ArAAs and other lipo-amino acids may involve their binding to one of the following receptors: GPR18, GPR55, GPR92, and/or GPR132 ( Bradshaw et al, 2009a ; Burstein, 2018 ).…”