Tricyclic antidepressant amitriptyline inhibits autophagic flux and prevents tube formation in vascular endothelial cells

Abstract

Amitriptyline is a tricyclic antidepressant and an inhibitor of lysosomal acid sphingomyelinase (ASM). Amitriptyline is well known for its cardiovascular side effects and toxicity in psychiatric patients. However, the mechanisms underlying the cardiovascular side effects of amitriptyline remain largely undefined. This study aimed to determine the effects of amitriptyline on angiogenic capability of vascular endothelial cells in physiological settings and identify its mechanism of action.The ex vivo aortic ring angiogenesis and in vitro-cultured endothelial cell tube formation assay were used to assess the effects of amitriptyline on endothelial angiogenic capability. It was demonstrated that amitriptyline impaired the angiogenesis of aortic rings, which was similar to that found in aortic rings with haploinsufficiency of the ASM gene. In cultured mouse microvascular endothelial cells (MVECs), amitriptyline impaired the proliferation and tube formation under basal condition, which were accompanied by attenuated angiogenic signalling pathways such as endothelial nitric oxide synthase, Akt and Erk1/2 pathways. Mechanistically, amitriptyline inhibited autophagic flux without affecting autophagosome biogenesis at basal condition. ASM gene silencing or autophagy inhibition mimics the inhibitory effects of amitriptyline on endothelial cell proliferation and tube formation. Collectively, our data suggest that amitriptyline inhibits endothelial cell proliferation and angiogenesis via blockade of ASM-autophagic flux axis. It is implicated that the cardiovascular side effects of amitriptyline may be associated with its inhibitory action on physiological angiogenesis.

Is Autophagy Involved in the Diverse Effects of Antidepressants?

“…In HepG2 cells, amitriptyline induced autophagy, mitophagy and cell death [118]. Finally, inhibition of the autophagic flux by antidepressants has also been reported in conjunction with the inhibition of cell proliferation: the TCA amitriptyline not only inhibits autophagic flux but also endothelial cell proliferation and tube formation [119].…”

Amitriptyline interferes with autophagy-mediated clearance of protein aggregates via inhibiting autophagosome maturation in neuronal cells

“…Several studies have shown that amitriptyline increases LC3B-II and Beclin 1 in neuronal cells 55 , augments the degradation of long-lived proteins through class-III PI3 kinase-dependent pathway 56 , and prevents neuronal degeneration in rotenone-induced PD mice model 57 . On the other hand, some studies have demonstrated that amitriptyline induces dopaminergic cell damage and causes PD-associated neurotoxicity 9 , and blocks the proliferation and angiogenesis in vascular endothelial cells by inhibiting autophagic flux 58 .…”

Contribution of transcription factor EB to adipoRon-induced inhibition of arterial smooth muscle cell proliferation and migration

“…Electric cell-substrate impedance-sensing assay of SMC migration. An electric cell-substrate impedance-sensing (ECIS) system (Applied Biophysics) was used to conduct migration assay, as we have described previously (15). SMCs (5 ϫ 10 4 per well) were cultured in 8W1Eϩ arrays (Applied Biophysics), and the resistance was subsequently monitored and measured using the ECIS software provided.…”