[Effects of electroacupuncture pretreatment on long-term postoperative cognitive dysfunction and neuron-inflammation in aged rats].

OBJECTIVE: To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction (POCD), neuronal apoptosis and neuron-inflammation in aged rats. METHODS: Thirty-six male SD rats aged 20 months were randomly divided into sham operation group, model group and electroacupuncture (EA) group, with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling, EA stimulation (2 Hz/15 Hz, 1 mA, 30 min) was applied to "Zusanli" (ST36), "Hegu" (LI4) and "Neiguan" (PC6) on the unaffected side of rats in the EA group, once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31-35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1 (HMGB1) and phosphorylated (p)-nuclear factor (NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin (IL)-6 and IL-1ß in the hippocampus were detected by Western blot. RESULTS: Compared with the sham operation group, the escape latency was prolonged (P<0.05); the frequency of crossing the original platform, ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased (P<0.05); the apoptosis rate of hippocampal neurons was significantly increased (P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1ß in hippocampus were increased (P<0.05) in the model group. Compared with the model group, the results of the above indexes were all opposite (P<0.05) in the EA group. CONCLUSION: EA preconditioning can regulate hippocampal inflammatory response, alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD, the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.

Electroacupuncture modulates gut microbiota in mice: A potential target in postoperative cognitive dysfunction.

The detailed mechanism of inflammation in postoperative cognitive dysfunction (POCD) is unclear. This study aimed to determine whether electroacupuncture (EA) ameliorates POCD by modulating gut microbial dysbiosis. Compared to the control group, mice in the EA group were treated at the acupoints Zusanli (ST36), Quchi (L111), Baihui (GV20), and Dazhui (GV14) 1 week before appendectomy. Novel object recognition and the Morris water maze tests were used to assess learning and spatial reference memory deficits, whereas hippocampus samples and stool samples were collected for central inflammatory tests and 16S-rRNA sequencing of intestinal flora, respectively. In amyloid precursor protein/presenilin 1 (APP/PS1) mice, EA enhanced spatial memory and learning deficits. The fecal microbial community was altered in APP/PS1 mice in the absence of EA following surgery. Among them, Coprococcus and Bacteroidetes were more abundant in the EA groups than in the control groups; however, Actinobacteriota, Helicobacteraceae, and Escherichia/shigella constitute the minor bacterial colonization in the EA groups. Furthermore, we found a significant negative correlation between Firmicutes and escape latency (Pearson correlation coefficient - 0.551, p < 0.01) and positive correlation between Proteobacteria and escape latency (Pearson correlation coefficient 0.462, p < 0.05). Electron microscopy revealed signs of blood-brain barrier (BBB) impairments and immunofluorescence images showed glial cells activated in the hippocampus of APP/PS mice without EA, and serum diamine oxidase levels were increased in these mice; whereas EA treatment significantly relieved the above pathological changes. Our findings implied that EA decreases hippocampal inflammation of APP/PS1 by upregulating benificial  gut microbiota, reducing BBB and intestinal barrier dysfunction, thus alleviates postoperative cognitive dysfunction. This may provide a novel target in POCD management.

Electroacupuncture ameliorates postoperative cognitive dysfunction and associated neuroinflammation via NLRP3 signal inhibition in aged mice.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is associated with worsened prognosis especially in aged population. Clinical and animal studies suggested that electroacupuncture (EA) could improve POCD. However, the underlying mechanisms especially EA's regulatory role of inflammasomes remain unclear. METHODS: The model of POCD was established by partial hepatectomy surgery in 18-month mice with or without postoperative EA treatment to the Baihui acupoint (GV20) for 7 days. Cognitive functions were assessed by Morris water maze test, and proinflammatory cytokines IL-1ß and IL-6 and microglia activity were assayed by qPCR, ELISA, or immunohistochemistry. Tight junction proteins, NLRP3 inflammasome and downstream proteins, and NF-κB pathway proteins were evaluated by western blotting. RESULTS: EA markedly preserved cognitive dysfunctions in POCD mice, associated with the inhibition of neuroinflammation as evidenced by reduced microglial activation and decreased IL-1ß and IL-6 levels in brain tissue. EA also preserved hippocampal neurons and tight junction proteins ZO-1 and claudin 5. Mechanistically, the activation of NLRP3 inflammasome and NF-κB was inhibited by EA, while NLRP3 activation abolished EA's treatment effects on cognitive function. CONCLUSION: EA alleviates POCD-mediated cognitive dysfunction associated with ameliorated neuroinflammation. Mechanistically, EA's treatment effects are dependent on NLRP3 inhibition.

Effect of electroacupuncture on postoperative cognitive dysfunction for patients undergoing total knee arthroplasty: A protocol for systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Electroacupuncture is increasingly used in rehabilitation for postoperative cognitive dysfunction (POCD), but relevant evidence remains unclear for patients receiving total knee arthroplasty (TKA). METHODS: The databases research of PubMed, EMBASE, CINAHL, and China National Knowledge Infrastructure (CNKI) will be conducted from inception to December 31, 2020. The relevant randomized controlled trials (RCTs) from data will be screened one by one. The remaining studies that meet the inclusion criteria will be extracted and analyzed using RevMan V.5.3 software. Paired 2 reviewers will assess quality of the included studies and publication bias by using the Cochrane Collaboration risk of bias tool, and Egger test and Begg test respectively. And grading of recommendations assessment, development and evaluation (GRADE) will be used to estimate the quality of evidence. RESULTS: In this study, we will analyze the effect of electroacupuncture on Mini-Mental State Examination (MMSE), interleukin 1ß (IL-1ß), tumor necrosis factor-α (TNF-α), S100-ß protein, and adverse events for patients with TKA. CONCLUSION: Our findings will provide evidence for the effectiveness of electroacupuncture on the treatment and prevention of POCD for TKA patients. REGISTRATION NUMBER: Available at: https://osf.io/azyt9 (DOI number: 10.17605/OSF.IO/AZYT9).

[Effect of electroacupuncture on cognitive functions, hippocampal HIF-1α and neurons apoptosis in postoperative cognitive dysfunction rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on learning and memory ability, hippocampal hypoxia inducible factor-1α(HIF-1α) and apoptosis in postoperative cognitive dysfunction(POCD) rats, and to investigate its mechanism underlying improvement of POCD. METHODS: A total of 90 aged male SD rats were randomized into a sham-operation group, a model group and an EA group, 30 rats in each group, which were further divided into 3 time-point subgroups (1, 3 and 7 days after intevention, 10 rats in each subgroup). In the model group and the EA group, left hepatectomy was adopted to establish the model of POCD. In the sham-operation group, the skin was sectioned and no hepatectomy was operated. In the EA group, EA was applied at "Siguan" ["Hegu" (LI 4) and "Taichong" (LR 3)] with dilatational wave, 2 Hz/100 Hz in frequency, 1 mA in intensity, 20 min each time, once a day. Morris water maze test was adopted to observe the cognitive functions. Real-time PCR and Western blot were used to measure the hippocampal level of HIF-1α. TUNEL method was used to evaluate the hippocampal level of neurons apoptosis. Double immunofluorescence labeling was used to detect the colocalization of HIF-1α and apoptosis in the EA group. RESULTS: Compared with the sham-operation group, the escape latency was prolonged and the frequency of platform leaping was reduced in the model group (P<0.05) after 1, 3, 7 days of intervention. Compared with the model group,the escape latency was shortened and the frequency of platform leaping was increased in the EA group (P<0.05) after 1, 3, 7 days of intervention. After 3 days of intervention, compared with the sham-operation group, the expressions of HIF-1α mRNA and protein, the level of apoptosis were increased in the model group (P<0.05); compared with the model group,the expressions of HIF-1α mRNA and protein, the level of apoptosis were decreased in the EA group (P<0.05). The colocalization of HIF-1α and apoptosis was observed in same cells in the EA group. CONCLUSION: Electroacupuncture improves cognitive functions in postoperative cognitive dysfunction rats, which may be related to its effect in down-regulating the expression of hippocampal HIF-1α and inhibiting the neurons apoptosis.

Application of Acupuncture to Attenuate Immune Responses and Oxidative Stress in Postoperative Cognitive Dysfunction: What Do We Know So Far?

Postoperative cognitive dysfunction (POCD) is a common sequela following surgery and hospitalization. The prevention and management of POCD are important during clinical practice. POCD more commonly affects elderly patients who have undergone major surgery and can result in major decline in quality of life for both patients and their families. Acupuncture has been suggested as an effective intervention for many neurological disorders. In recent years, there are increasing interest in the use of acupuncture to prevent and treat POCD. In this review, we summarized the clinical and preclinical evidence of acupuncture on POCD using a narrative approach and discussed the potential mechanisms involved. The experimental details and findings of studies were summarized in tables and analyzed. Most of the clinical studies suggested that acupuncture before surgery could reduce the incidence of POCD and reduce the levels of systematic inflammatory markers. However, their reliability is limited by methodological flaws. Animal studies showed that acupuncture reduced cognitive impairment and the associated pathology after various types of surgery. It is possible that acupuncture modulates inflammation, oxidative stress, synaptic changes, and other cellular events to mitigate POCD. In conclusion, acupuncture is a potential intervention for POCD. More clinical studies with good research design are required to confirm its effectiveness. At the same time, findings from animal studies will help reveal the protective mechanisms, in which systematic inflammation is likely to play a major role.