mTORC2 activation protects retinal ganglion cells via Akt signaling after autophagy induction in traumatic optic nerve injury. 2019

Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
Institute of Eye Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.

Traumatic optic neuropathy is an injury to the optic nerve that leads to vision loss. Autophagy is vital for cell survival and cell death in central nervous system injury, but the role of autophagy in traumatic optic nerve injury remains uncertain. Optic nerve crush is a robust model of traumatic optic nerve injury. p62 siRNA and rapamycin are autophagy inducers and have different neuroprotective effects in the central nervous system. In this study, p62 and rapamycin induced autophagy, but only p62 siRNA treatment provided a favorable protective effect in visual function and retinal ganglion cell (RGC) survival. Moreover, the number of macrophages at the optic nerve lesion site was lower in the p62-siRNA-treated group than in the other groups. p62 siRNA induced more M2 macrophage polarization than rapamycin did. Rapamycin inhibited both mTORC1 and mTORC2 activation, whereas p62 siRNA inhibited only mTORC1 activation and maintained mTORC2 and Akt activation. Inhibition of mTORC2-induced Akt activation resulted in blood-optic nerve barrier disruption. Combined treatment with rapamycin and the mTORC2 activator SC79 improved RGC survival. Overall, our findings suggest that mTORC2 activation after autophagy induction is necessary for the neuroprotection of RGCs in traumatic optic nerve injury and may lead to new clinical applications.

UI MeSH Term Description Entries
D008297 Male Males
D004195 Disease Models, Animal Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases. Animal Disease Model,Animal Disease Models,Disease Model, Animal
D000066829 Neuroprotection The physiological processes and techniques used by the body to prevent neuronal injury and degeneration in the central nervous system following acute disorders or as a result of chronic neurodegenerative diseases. Neural Protection,Neuron Protection,Neuronal Protection,Protection, Neural,Protection, Neuron,Protection, Neuronal
D000071456 Sequestosome-1 Protein A multidomain protein that is highly conserved among multicellular organisms. It contains a ZZ-type ZINC FINGER domain, C-terminal UBIQUITIN - associated (UBA) domain, and interacts with many other signaling proteins and enzymes including, atypical PROTEIN KINASE C; TNF RECEPTOR-ASSOCIATED FACTOR 6; subunits of the mTORC1 complex, and CASPASE-8. It functions in AUTOPHAGY as a receptor for the degradation of ubiquitinated substrates, and to co-ordinate signaling in response to OXIDATIVE STRESS. EBI3-Associated Protein of 60 KDa,EBIAP Protein,Phosphotyrosine-Independent Ligand For The Lck SH2 Domain Of 62 Kda,Ubiquitin-Binding Protein p62,EBI3 Associated Protein of 60 KDa,Phosphotyrosine Independent Ligand For The Lck SH2 Domain Of 62 Kda,Sequestosome 1 Protein,Ubiquitin Binding Protein p62
D000076225 Mechanistic Target of Rapamycin Complex 2 A multiprotein complex consisting of mTOR KINASE; MLST8 PROTEIN; rapamycin-insensitive companion of mTOR protein (RICTOR PROTEIN); and PRR5 (proline-rich protein 5). Like mTORC1, it also regulates cell growth and proliferation in response to growth factors but may not be as sensitive to nutrient availability and is insensitive to SIROLIMUS. In contrast to mTORC1, it can regulate the ACTIN CYTOSKELETON through RHO GTPASES to promote the formation of STRESS FIBERS. The mTORC2 complex also plays a critical role in AKT1 PROTEIN KINASE phosphorylation and activation. MTORC-2,TOR Complex 2,TORC2,Target of Rapamycin Complex 2,mTORC2,Complex 2, TOR
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001343 Autophagy The segregation and degradation of various cytoplasmic constituents via engulfment by MULTIVESICULAR BODIES; VACUOLES; or AUTOPHAGOSOMES and their digestion by LYSOSOMES. It plays an important role in BIOLOGICAL METAMORPHOSIS and in the removal of bone by OSTEOCLASTS. Defective autophagy is associated with various diseases, including NEURODEGENERATIVE DISEASES and cancer. Autophagocytosis,ER-Phagy,Lipophagy,Nucleophagy,Reticulophagy,Ribophagy,Autophagy, Cellular,Cellular Autophagy,ER Phagy
D012165 Retinal Ganglion Cells Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM. Cell, Retinal Ganglion,Cells, Retinal Ganglion,Ganglion Cell, Retinal,Ganglion Cells, Retinal,Retinal Ganglion Cell
D015398 Signal Transduction The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway. Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal
D017208 Rats, Wistar A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain. Wistar Rat,Rat, Wistar,Wistar Rats

Related Publications

Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
August 2007, The European journal of neuroscience,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
August 2023, Life science alliance,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
January 2014, Chinese medical journal,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
January 2020, Marine drugs,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
January 2006, Advances in experimental medicine and biology,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
December 2023, Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
January 2012, Cell death and differentiation,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
October 2023, Molecular neurobiology,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
July 2016, Experimental eye research,
Yao-Tseng Wen, and Jia-Rong Zhang, and Kishan Kapupara, and Rong-Kung Tsai
January 1999, Restorative neurology and neuroscience,
Copied contents to your clipboard!