ABSTRACT
Aging is a risk factor for multiple retinal degeneration diseases. Entraining brain gamma oscillations with gamma-flicker light (γFL) has been confirmed to coordinate pathological changes in several Alzheimer's disease mouse models and aged mice. However, the direct effect of γFL on retinal aging remains unknown. We assessed retinal senescence-associated beta-galactosidase (ß-gal) and autofluorescence in 20-month-old mice and found reduced ß-gal-positive cells in the inner retina and diminished lipofuscin accumulation around retinal vessels after 6 days of γFL. In immunofluorescence, γFL was further demonstrated to ameliorate aging-related retinal changes, including a decline in microtubule-associated protein 1 light chain 3 beta expression, an increase in complement C3 activity, and an imbalance between the anti-oxidant factor catalase and pro-oxidant factor carboxymethyl lysine. Moreover, we found that γFL can increase the expression of activating transcription factor 4 (ATF4) in the inner retina, while revealing a decrease of ATF4 expression in the inner retina and positive expression in the outer segment of photoreceptor and RPE layer for aged mice. Western blotting was then used to confirm the immunofluorescence results. After mRNA sequencing (NCBI Sequence Read Archive database: PRJNA748184), we found several main mechanistic clues, including mitochondrial function and chaperone-mediated protein folding. Furthermore, we extended γFL to aged Apoe-/- mice and showed that 1-m γFL treatment even improved the structures of retinal-pigment-epithelium basal infolding and Bruch's membrane. Overall, γFL can orchestrate various pathological characteristics of retinal aging in mice and might be a noninvasive, convenient, and tissue-specific therapeutic strategy for retinal aging.
Subject(s)
Complement C3 , Lipofuscin , Activating Transcription Factor 4/metabolism , Animals , Antioxidants/metabolism , Apolipoproteins E/metabolism , Catalase/metabolism , Complement C3/metabolism , Lipofuscin/metabolism , Lysine/metabolism , Mice , Microtubule-Associated Proteins/metabolism , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Retina/metabolism , beta-Galactosidase/metabolismABSTRACT
In this study, we successfully characterised the phenolic profiles of Sarcandra glabra (Thunb.) Nakai by high-performance liquid chromatography (HPLC) fingerprinting analyses and mass spectrometry (MS) identification. We first established a specific and valid HPLC approach for fingerprint analysis of S. glabra based on HPLC-UV detection. Using several chemometric methods such as similarity evaluation and principal components analysis, we determined herb-markers peaks from many HPLC peaks. The structures of these herb-markers were further identified targetedly by electrospray ionisation tandem mass spectrometry (ESI-MS/MS)/time-of-flight mass spectrometry (TOF-MS) analyses. As results, four phenolics, including chlorogenic acid, caffeic acid, 4-O-glucopyranosyl rosmarinic acid and rosmarinic acid, were characterised as major herb-markers for the stems of S. glabra, while another three phenolics, including kaempferol-3-O-ß-d-glucuronic acid, chlorogenic acid and rosmarinic acid, were characteristic components for the leaves. The compounds may be very useful for further phenolome analysis.
Subject(s)
Magnoliopsida/chemistry , Phenols/chemistry , Plant Extracts/chemistry , Chromatography, High Pressure Liquid/methods , Molecular Structure , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methodsABSTRACT
OBJECTIVE: To reveal the relationship between the storage time of the bark of Magnolia officinalis and the content of phenols in it, and lay a theoretical foundation for the harvest, processing, management and storage. METHOD: The contents of magnolol and honokoiol in 15 bark samples, collected from the main producing areas in China, were determined in the time of freshly harvest and 3 and 10 years after respectively by HPLC method. RESULT: It showed that within a certain period of time, bark storage was favorable to conversion and accumulation of phenols, that the content of magnolol tended to increase from year 0 to year 3, then followed by slight decrease with years on account of volatilization of phenols, but was still higher when the bark was stored for 10 years than that that when the bark was freshly harvested, and the content of honokoiol still tended to increase when the bark had been stored for 10 years. CONCLUSION: The phenols in bark of M. officinalis is quite stable and the bark can be stored for 10 years or longer.