title: The effects and regulatory mechanism of RIP3 on RGC-5 necroptosis following elevated hydrostatic pressure.
abstract: Necroptosis is a type of regulated cell death that has been implicated in various diseases. Receptor-interacting protein 3 (RIP3), a member of the RIP family, is an important mediator of the necroptotic pathway. Cleavage of RIP3 at Asp328 by caspase-8 abolishes the kinase activity of RIP3, which is critical for necroptosis. Moreover, RIP3 is significantly upregulated during the early stages of acute high intra-ocular pressure and oxygen glucose deprivation. In this study, the effects of RIP3 during elevated hydrostatic pressure (EHP) were investigated and the possible mechanism through which caspase-8 regulated RIP3 cleavage was explored. Flow cytometry analysis revealed that the number of EHP-induced necrotic retinal ganglion cell 5 (RGC-5) cells was reduced after RIP3-knockdown. Furthermore, malondialdehyde (MDA) levels and glycogen phosphorylase (PYGL) activity in normal RGC-5 cells were much higher than those in RIP3-knockdown cells after EHP. EHP-induced RGC-5 necrosis was significantly reduced after treatment with butylated hydroxyanisole (BHA), a reactive oxygen species (ROS) scavenger. MDA levels and PYGL activity were lower in normal RGC-5 cells than those in cells with caspase-8 inhibition after EHP. Western blot analysis demonstrated that the RIP3 cleavage product was upregulated in cells with caspase-8 inhibition. Additionally, flow cytometry analysis revealed that the number of EHP-induced necrotic RGC-5 cells was increased after caspase-8 inhibition. Our results suggested that RGC-5 necroptosis following EHP was mediated by RIP3 through induction of PYGL activity and subsequent ROS accumulation. Thus, caspase-8 may participate in the regulation of RGC-5 necroptosis via RIP3 cleavage.
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shang
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ding
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Lvshuang
authors.initials: L
authors.lastname: Liao
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Jufang
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xiong
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D053181:Caspase 8 / Q000378:metabolism*; D002460:Cell Line; D005434:Flow Cytometry; D024981:Glycogen Phosphorylase / Q000378:metabolism; D006874:Hydrostatic Pressure; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D009336:Necrosis; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D002083:Butylated Hydroxyanisole; D008315:Malondialdehyde; D024981:Glycogen Phosphorylase; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; C485615:Ripk3 protein, mouse; D053181:Caspase 8
keywords: caspase-8; elevated hydrostatic pressure; necroptosis; receptor-interacting protein 3; retinal ganglion cell-5