Ninjurin-1 upregulated by TNFα receptor 1 stimulates monocyte adhesion to human TNFα-activated endothelial cells; benefic effects of amlodipine
- Life Sci. 2020 May 15;249:117518. doi: 10.1016/j.lfs.2020.117518.
- 1. Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, Bucharest, Romania.
- 2. Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, Bucharest, Romania. Electronic address: [email protected].
Aims: The objectives of the present study were to investigate the mechanisms of Ninj-1 regulation in TNFα-activated human endothelial cells (HEC), and to test if Amlodipine (AML) ameliorates the inflammatory stress by decreasing Ninj-1 expression.
Main methods: TNFα-activated HEC with/without AML (0.1 μM and 1 μM) were used. TNFα-receptor 1 (TNFR1) was silenced and inhibitors for oxidative stress (N-acetyl cysteine), endoplasmic reticulum stress (salubrinal, 4-phenyl butyric acid), or NF-kB (Bay 11-7085) and p38 MAPK (SB203580) were used. Levels of Ninj-1, TNFR1, monocyte adhesion, endoplasmic reticulum stress (ERS) sensors, NADPH oxidase- and mitochondria-derived oxidative species were evaluated.
Key findings: The novel findings that we report here are: (i) silencing the endothelial TNFR1 leads to decreased Ninj-1 expression and diminished monocyte adhesion; (ii) increased oxidative stress, ERS and NF-kB activation enhance Ninj-1 expression and monocyte adhesion; (iii) up-regulation of endothelial Ninj-1 expression stimulates monocytes adhesion to TNFα - activated HEC; (iv) AML diminishes monocyte adhesion by reducing Ninj-1 expression through mechanisms involving the decrease of NADPH Oxidase and mitochondria-dependent oxidative stress, ERS and NF-kB. In addition, AML alleviates Apoptosis by reducing the pro-apoptotic CHOP expression and re-establishing the mitochondrial transmembrane potential.
Significance: The results of the present study suggest that Ninj-1 and the proteins involved in its regulation can be considered therapeutic targets for the alleviation of inflammation- dependent disorders. In addition, we demonstrate that some of the benefic effects of AML can be achieved through regulation of Ninj-1.