Mechanisms of Acupuncture in Improving Alzheimer's Disease Caused by Mitochondrial Damage

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways

OBJECTIVE

To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo.

METHODS

Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- β (Aβ), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.

RESULTS

Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01).

CONCLUSION

EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

Research status, hotspots and trends of acupuncture and moxibustion in the treatment of Alzheimer's disease: A bibliometric analysis

BACKGROUND

Acupuncture and moxibustion (AM) are utilized to treat Alzheimer's disease (AD). However, no bibliometric analysis has explored this issue. Thus, this study investigated the status, hotspots and trends of AM in the treatment of AD.

METHODS

CiteSpace and VOSviewer softwares were used to analyze the literature on the AM for AD in the Web of Science Core Collection database. We analyzed the data of countries/regions, institutions, journals, authors, keywords, and cited references.

RESULTS

After removing duplicates, 193 articles were retrieved. The number of publications on this topic has increased gradually. The most productive and collaborative country was China (143 documents), followed by South Korea (19). The top 3 active academic institutions were Beijing University of Chinese Medicine, Capital Medicine University, and Guangzhou University of Chinese Medicine. The most productive journal was Evidence-based Complementary and Alternative Medicine (13 documents), followed by the Frontiers in Aging Neuroscience (10), Medicine (10), and Neural Regeneration Research (10). The top 3 co-cited journals were Evidence-based Complementary and Alternative Medicine (156 citations), Acupuncture Electro-therapeutics Research (152), and Acupuncture in Medicine (146). The research hotspots in this domain are dementia, memory, hippocampus, mouse models, and Parkinson's disease. Major frontiers are comparing the therapeutic effects of acupuncture and donepezil and electroacupuncture at different frequencies in this field.

CONCLUSION

This bibliometric study identified relevant hotspots and trends in research on AM in the treatment of AD, which can provide researchers with key information in this domain and help further explore new research directions.