Electroacupuncture improves myocardial ischemia injury via activation of adenosine receptors

Electroacupuncture Improves Cardiac Function via Inhibiting Sympathetic Remodeling Mediated by Promoting Macrophage M2 Polarization in Myocardial Infarction Mice

Electroacupuncture (EA) at the Neiguan acupoint (PC6) has shown significant cardioprotective effects. Sympathetic nerves play an important role in maintaining cardiac function after myocardial infarction (MI). Previous studies have found that EA treatment may improve cardiac function by modulating sympathetic remodeling after MI. However, the mechanism in how EA affects sympathetic remodeling and improves cardiac function remains unclear. The aim of this study is to investigate the cardioprotective mechanism of EA after myocardial ischemic injury by improving sympathetic remodeling and promoting macrophage M2 polarization. We established a mouse model of MI by occluding coronary arteries in male C57/BL6 mice. EA treatment was performed at the PC6 with current intensity (1 mA) and frequency (2/15 Hz). Cardiac function was evaluated using echocardiography. Heart rate variability in mice was assessed via standard electrocardiography. Myocardial fibrosis was evaluated by Sirius red staining. Levels of inflammatory factors were assessed using RT-qPCR. Sympathetic nerve remodeling was assessed through ELISA, western blotting, immunohistochemistry, and immunofluorescence staining. Macrophage polarization was evaluated using flow cytometry. Our results indicated that cardiac systolic function improved significantly after EA treatment, with an increase in fractional shortening and ejection fraction. Myocardial fibrosis was significantly mitigated in the EA group. The sympathetic nerve marker tyrosine hydroxylase and the nerve sprouting marker growth-associated Protein 43 were significantly reduced in the EA group, indicating that sympathetic remodeling was significantly reduced. EA treatment also promoted macrophage M2 polarization, reduced levels of inflammatory factors TNF-α, IL-1β, and IL-6, and decreased macrophage-associated nerve growth factor in myocardial tissue. To sum up, our results suggest that EA at PC6 attenuates sympathetic remodeling after MI to promote macrophage M2 polarization and improve cardiac function.

The role of purinergic signaling in acupuncture-mediated relief of neuropathic and inflammatory pain

Acupuncture is a traditional medicinal practice in China that has been increasingly recognized in other countries in recent decades. Notably, several reports have demonstrated that acupuncture can effectively aid in pain management. However, the analgesic mechanisms through which acupuncture provides such benefits remain poorly understood. Purinergic signaling, which is mediated by purine nucleotides and purinergic receptors, has been proposed to play a central role in acupuncture analgesia. On the one hand, acupuncture affects the transmission of nociception by increasing adenosine triphosphate dephosphorylation and thereby decreasing downstream P2X3, P2X4, and P2X7 receptors signaling activity, regulating the levels of inflammatory factors, neurotrophic factors, and synapsin I. On the other hand, acupuncture exerts analgesic effects by promoting the production of adenosine, enhancing the expression of downstream adenosine A1 and A2A receptors, and regulating downstream inflammatory factors or synaptic plasticity. Together, this systematic overview of the field provides a sound, evidence-based foundation for future research focused on the application of acupuncture as a means of relieving pain.

Purinergic signaling in myocardial ischemia-reperfusion injury

Purines and their derivatives, extensively distributed in the body, act as a class of extracellular signaling molecules via a rich array of receptors, also known as purinoceptors (P1, P2X, and P2Y). They mediate multiple intracellular signal transduction pathways and participate in various physiological and pathological cell behaviors. Since the function in myocardial ischemia-reperfusion injury (MIRI), this review summarized the involvement of purinergic signal transduction in diversified pathological processes, including energy metabolism disorder, oxidative stress injury, calcium overload, inflammatory immune response, platelet aggregation, coronary vascular dysfunction, and cell necrosis and apoptosis. Moreover, increasing evidence suggests that purinergic signaling also mediates the prevention and treatment of MIRI, such as ischemic conditioning, pharmacological intervention, and some other therapies. In conclusion, this review exhibited that purinergic signaling mediates the complex processes of MIRI which shows its promising application and prospecting in the future.

Changes in Acupuncture-Induced Specific Acupoint Neurotransmitters are Possibly Related to Their Physiological Functions in Rats

This study investigated changes in neurotransmitters induced by the application of electroacupuncture (EA) at Zusanli (ST36) and Neiguan (PC6). A total of 30 rats were divided into five groups: sham, ST (EA at bilateral ST36 and ST37), ScT (ST plus previous neurectomy of the bilateral sciatic nerves), ScS (sham plus previous neurectomy of the bilateral sciatic nerve), and PC (EA at bilateral PC6 and PC7). The P2X2 receptor expression was stronger in the sham group than in the ST and PC groups (both p < 0.05) but similar between the sham and ScT groups (p > 0.05). Dopamine levels in the extracellular fluid surrounding the acupoints were higher in the PC group than in the sham and ST groups during the postacupuncture period (both p < 0.05). Glutamate levels in the extracellular fluid surrounding the acupoints were higher in the ST group than in the sham group during the acupuncture period (p < 0.05) and higher in the ST group than in the sham and PC groups during the postacupuncture period (both p < 0.05). Serum adrenaline and noradrenaline levels were higher in the PC group than in the sham, ST, and ScT groups (all p < 0.05). Glutamate levels in the CSF were higher in the ST group than in the sham, ScS, and PC groups (all p < 0.05). GABA levels in the CSF were higher in the ST group than in the sham, ScT, and PC groups (all p < 0.05). EA at ST36 and ST37 and PC6 and PC7 exerted an analgesic effect, EA at PC6 and PC7 can enhance heart function, and EA at ST36 and ST37 modulates the cerebral cortex. However, the study needs an evaluation of direct pain behavior, heart function, and brain function in the future.

Acupuncture at Neiguan suppresses PVCs occurring post-myocardial infarction by alleviating inflammation and fibrosis

Background

Acupuncture at Neiguan (PC6) has long been used for treating cardiovascular diseases, but its antiarrhythmic effect and the underlying mechanisms have not yet been well investigated, especially regarding premature ventricular complexes (PVCs) that occur post-myocardial infarction (MI). The purpose of this study was to study the antiarrhythmic effect of manual acupuncture applied to PC6 for a relatively long period (28 days) and to elucidate the mechanism in mice.

Methods

An MI mouse model was generated by ligating the left anterior descending coronary artery in male C57/BL6 mice (n = 31). Manual acupuncture at PC6 was applied seven times weekly for 4 weeks. The state of myocardial injury was characterized by electrocardiography (ECG) and echocardiography. Inflammation was detected by ELISA and immunohistochemical stanning. Fibrosis was evaluated by Masson’s trichrome staining. RNA sequencing was used to explore the differentially expressed genes (DEGs) among the different groups after treatment.

Results

Acupuncture at PC6 lowered the incidence of spontaneous PVCs after MI injury (1/9, 11%) compared to that in mice without acupuncture treatment (6/9, 67%) and improved the ejection fraction from 31.77% in the MI mice to 44.18% in the MI + PC6 mice. Fibrosis was reduced after PC6 treatment. RNA-seq showed many DEGs involved in the immune system and inflammatory response pathway. Further studies confirmed that inflammation at the circulation level and cardiac tissue was inhibited in MI + PC6 mice, accompanied by suppressed sympathetic activation.

Conclusions

In conclusion, 28-day treatment of acupuncture at PC6 reduced spontaneous PVCs and improved systolic function, possibly by suppressing inflammatory response-mediated fibrosis and sympathetic hyperactivity.

Research on the Specificity of Electrophysiological Signals of Human Acupoints Based on the 90-Day Simulated Weightlessness Experiment on the Ground

Acupoint specificity for diseases has consistently been the focus of acupuncture research owing to its excellent prospects for clinical diagnosis and treatment. However, the specificity of cardiovascular and sleep functions in terms of electrical signals at acupoints remains unclear. In this study, five volunteers were recruited and their electrophysiological signals of GV20 (baihui), RN17 (danzhong), PC6 (neiguan), and SP6 (sanyinjiao) and the corresponding sham points, Pittsburgh sleep quality index, blood pressure, and echocardiography were monitored over four periods of 90-day head-down bed rest (HDBR). The results demonstrated that the power and characteristic amplitude of the acupoints were more significant than those of the sham points under normal conditions. And along with the altered physiological condition of the body after HDBR, the differential signal characteristic amplitude (DSCA) and the power of the acupoints were decreased to a larger extent than those of the sham points. In addition, the difference between the power of acupuncture and sham points was also reduced. During the recovery period, except for GV20, the power and DSCA of other acupoints did not return to normal. In terms of DSCA, GV20 is related to human sleep function and other acupoints are related to cardiovascular function. The above results show that the electrophysiological signals of acupoints are disease-specific and more accurately reflect the changes of physiological homeostasis. The research conduces to the development of acupuncture-based disease diagnosis and treatment integrated methods, and the realization of the portable and accurate diagnosis and regulation of diseases in space medicine.