Journal: Aging Cell
Article Title: Activated mTOR Signaling in the RPE Drives EMT , Autophagy, and Metabolic Disruption, Resulting in AMD ‐Like Pathology in Mice
doi: 10.1111/acel.70018
Figure Lengend Snippet: βA3/A1‐crystallin overexpression in the RPE rescues autophagy and melanosome alterations and retinal structure/function in mLST8 KI mice. (a) Cartoon showing the strategy for subretinal injection of the AAV2‐m Cryba1 construct into one eye of 8‐month‐old mLST8 KI mice, with the contralateral eyes receiving PBS vehicle. Animals were euthanized 2 and 4 months after injection. (b, c) Western blot analysis and densitometry showing that Cryba1 overexpression in the RPE (confirmed by western blot in b) of mLST8 KI mice could rescue the abnormal levels of both mTORC1 (p‐S6K) and mTORC2 (p‐Akt1) targets (b), and the melanosome marker (PMEL; b), as well as rescued the levels of major regulators of autophagosome formation (Atg9b, Atg7; c) in these animals (b, c), relative to PBS injected eyes (b, c). n = 3. * p < 0.05, ** p < 0.01. AAV2‐m Cryba1 treatment (subretinal injection) to mLST8 KI mice for 4 months rescued retinal function as evident from increase in scotopic (d) a‐ and (e) b‐wave amplitudes after the treatment, compared to PBS‐injected contralateral eyes of the KI mouse. n = 4. **** p < 0.0001, * p < 0.05. (f) AAV2‐m Cryba1 treatment to mLST8 KI mice for 4 months also rescued early RPE changes (arrows) like the patchy appearance of the monolayer and decline in thickness (spider plot), compared to PBS–treated contralateral eyes of the mLST8 KI mouse. n = 4. Scale bar = 20 μm. * p < 0.05. (g) Cartoon depicting overexpression of mLST8 in RPE cells ( mLST8 KI mice) activated both mTORC1 and mTORC2, disrupting glucose metabolism, mitochondrial function, autophagy, and melanosome function, leading to debris accumulation, EMT activation, and age‐related retinal degeneration resembling AMD. Targeting mTOR with inhibitors or modulators rescued these changes, suggesting a potential therapeutic strategy for retinal diseases by modulating mTOR signaling. Created with BioRender.com .
Article Snippet: The cells from all the experimental groups were lysed in the CHAPS lysis buffer, and Raptor and Rictor antibodies were used to immunoprecipitate mTOR bound complexes using protein Ig beads (Thermo Fisher, 88802). mTORC1 and mTORC2 target proteins S6K1 (Sino Biological, 10099‐H09B‐50) and Akt1 (EMD Milipore, 14–279) were given to the immune‐precipitated complexes and incubated for 15 min in 37°C.
Techniques: Over Expression, Injection, Construct, Western Blot, Marker, Activation Assay