Inhibition of PIKfyve Ameliorates the Proliferation and Migration of Vascular Smooth Muscle Cells and Vascular Intima Hyperplasia By Reducing mTORC1 Activity

Abstract

This study was designed to investigate the role and mechanism of PIKfyve in the proliferation and migration of vascular smooth muscle cells (VSMCs) and vascular intima hyperplasia. We first observed increased protein levels of PIKfyve, phospho (p)-S6 Ribosomal Protein (S6) Ser235/236 , p-4EBP1 Thr37/46 in VSMCs after 24 hours of platelet-derived growth factor (PDGF)-BB treatment. By using cell counting kit-8 assay, Ki-67 immunofluorescence staining and wound healing assay, we found that PIKfyve inhibition ameliorated the enhanced activity of VSMC proliferation and migration induced by PDGF-BB. Silencing PIKfyve also suppressed the phosphorylation of S6 and 4EBP1 (2 major effectors of mammalian target of rapamycin complex 1), glucose consumption, activity of hexokinase, and LDH in PDGF-BB-challenged VSMCs. After rescuing the phosphorylation of S6 and 4EBP1 by silencing Tsc1, the suppressive effects of PIKfyve inhibition on glucose utilization, proliferation, and migration in VSMCs were abolished. The animal model of vascular restenosis was established in C57BL/6J mice by wire injury. We found the expression of PIKfyve was increased in carotid artery at day 28 after injury. Reducing the activity of PIKfyve alleviated vascular neointima hyperplasia after injury. In conclusion, targeting PIKfyve might be a novel effective method to reduce the proliferation and migration of VSMCs and vascular restenosis by affecting mammalian target of rapamycin complex 1-mediated glucose utilization.

MTMR7 suppresses the phenotypic switching of vascular smooth muscle cell and vascular intimal hyperplasia after injury via regulating p62/mTORC1-mediated glucose metabolism

“…Upon cellular stress, including mechanical injury, abnormal secretion of growth factors, and hypoxia, metabolic shift from lipid utilization to glycolysis occurs to adapt the stress (Rashdan et al, 2020). There are a series of evidences that abnormal glucose metabolism shift is involved in the phenotypic switching of VSMC (Gu et al, 2022;Shi et al, 2020). Consistently, our current study also demonstrated that glucose uptake, the activities of key glycolytic enzymes, and glycolytic capacity were markedly enhanced in VSMC after PDGF-BB stimulus.…”

“…mTORC1 is an important effective complex of mTOR and functions in cellular proliferation, migration, autophagy, energy metabolism, and mitochondrial homeostasis through its downstream molecules, S6 and 4EBP1 (Saxton and Sabatini, 2017). It is well established that mTORC1 plays a fundamental role in glycolysis and phenotypic switching of PDGF-BB-stimulated VSMC (Gu et al, 2022). Our results con rmed that MTMR7 could diminish PDGF-BB-induced mTORC1 activation in VSMC.…”

TMT proteomics analysis reveals the mechanism of bleomycin-induced pulmonary fibrosis and effects of Ginseng honeysuckle superfine powdered tea

“…Su et al reported that PIKfyve as a pharmacological target to interfere with host cell endocytosis is an effective way to block virus infection [ 21 ]. Moreover, inhibiting PIKfyve may be a new and effective method to reduce the proliferation and migration of vascular smooth muscle cells and vascular restenosis by affecting mammalian targets of rapamycin complex 1-mediated glucose utilization [ 22 ]. AFF4 is a member of the AF4 family and contains a serine-rich transcriptional activation domain.…”

Decrease in Tripartite Motif Containing 24 suppresses hypoxia-induced proliferation and migration of pulmonary arterial smooth muscle cells via the AKT/mammalian target of rapamycin complex 1 pathway

“…For siRNA transfection, PASMCs were incubated with the mixture of control siRNA or Tsc1 siRNA (siTsc1) and 10 μL X-tremeGENE siRNA transfection reagent for 8 h. Then, PASMCs were cultured for another 48 h before experiments. The sequence of siTsc1: GCUUUGACUCUCCCUUCUA [ 15 ]. SC-79 (10 μM; MCE, Shanghai, China) was used to treat PASMCs for 24 h [ 16 ].…”

“…Wound-healing assay was performed as a previous study described [ 15 ]. PASMCs were cultured on a 6-well plate and grown to 90% confluency.…”