Electroacupuncture Improved the Function of Myocardial Ischemia Involved in the Hippocampus-Paraventricular Nucleus-Sympathetic Nerve Pathway

Modulating activity of PVN neurons prevents atrial fibrillation induced circulation dysfunction by electroacupuncture at BL15

BACKGROUND

Circulation dysfunction is a major contributing factor to thrombosis in patients with atrial fibrillation (AF) for which effective interventions are lacking. Growing evidence indicates that regulating the paraventricular nucleus (PVN), an autonomic control center, could offer a novel strategy for treating cardiovascular and circulatory diseases. Concurrently, electroacupuncture (EA) at Xinshu (BL15), a form of peripheral nerve stimulation, has shown efficacy in treating several cardiovascular conditions, although its specific mechanism remains unclear. This study aimed to assess the impact of EA at BL15 on circulatory dysfunction in a rat AF model and investigate the pivotal role of PVN neuronal activity.

METHODS

To mimic the onset of AF, male SD rats received tail intravenous injection of ACh-CaCl2 and were then subjected to EA at BL15, sham EA, or EA at Shenshu (BL23). Macro- and micro-circulation function were evaluated using in vivo ultrasound imaging and laser doppler testing, respectively. Vasomotricity was assessed by measuring dimension changes during vascular relaxation and contraction. Vascular endothelial function was measured using myograph, and the activation of the autonomic nerve system was evaluated through nerve activity signals. Additionally, chemogenetic manipulation was used to block PVN neuronal activation to further elucidate the role of PVN activation in the prevention of AF-induced blood circulation dysfunction through EA treatment.

RESULTS

Our data demonstrate that EA at BL15, but not BL23 or sham EA, effectively prevented AF-induced macro- and micro-circulation dysfunction. Furthermore, EA at BL15 restored AF-induced vasomotricity impairment. Additionally, EA treatment prevented abnormal activation of the autonomic nerve system induced by AF, although it did not address vascular endothelial dysfunction. Importantly, excessive activation of PVN neurons negated the protective effects of EA treatment on AF-induced circulation dysfunction in rats.

CONCLUSION

These results indicate that EA treatment at BL15 modulates PVN neuronal activity and provides protection against AF-induced circulatory dysfunction.

Electroacupuncture ameliorates cardiac dysfunction in myocardial ischemia model rats: a potential role of the hypothalamic-pituitary-adrenal axis

OBJECTIVE

To verify the hypothesis that electroacupuncture inhibits the hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis regulating the expression of glial fibrillary acidic protein (GFAP) in the hippocampus of acute myocardial ischemia (AMI) rats.

METHODS

Sixty-six healthy male Sprague-Dawley rats were randomly divided into five groups: Sham, AMI (Model), electroacupuncture at Shenmen (HT7)-Tongli (HT5) segment (EA), non-acupoint electroacupuncture (Control), and Model + corticosterone (Model + CORT). AMI was induced occlusion of the left anterior descending coronary artery, followed by 3 d of electroacupuncture at Shenmen (HT7)-Tongli (HT5) segment. In the Control group, electroacupuncture was applied at points lying 5 and 10 mm from the base of the tail. The AMI + CORT group was injected with CORT (20 mg/kg) in saline. Hemorheology, electrocardiography (ECG), hematoxylin and eosin staining, and expression of glycogen phosphorylase BB (GPBB) and heart-type fatty acid-binding protein (H-FABP) were used to assess cardiac function. The effects of adrenocorticotropic hormone (ACTH) and CORT were evaluated by enzyme-linked immunosorbent assay. Protein expression in the Sham and Model groups were screened by tandem mass tag-based quantitative proteomics analysis. Protein expression was evaluated by Western blotting (vimentin and GFAP) and immunofluorescence staining (GFAP).

RESULTS

Compared with the Sham group, the hemorheology indicators, heart rate, ECG-ST segment elevation, and GPBB and H-FABP levels were higher in Model rats. The EA group showed reductions in these indicators compared with the Model group. Similarly, in Model rats, the expression of ACTH and CORT were significantly increased compared with the Sham group. The EA group also showed reduced expression of ACTH and CORT. Importantly, proteomics analysis showed that vimentin was differentially expressed in Model rats. Compared with the Sham group, vimentin and GFAP expression in the hippocampus was increased in the Model group but decreased in the AMI + EA group. Additionally, intraperitoneal injection of CORT aggravated the expression of GPBB, H-FABP and GFAP.

CONCLUSIONS

Our results suggested that electroacupuncture may protect against cardiac injury induced by AMI through regulation of HPA axis hyperactivity, and that hippocampal GFAP may play an important role in the regulation.

The autonomic nervous system: A potential link to the efficacy of acupuncture

The autonomic nervous system (ANS) is a diffuse network that regulates physiological systems to maintain body homeostasis by integrating inputs from the internal and external environment, including the sympathetic, parasympathetic, and enteric nervous systems (ENS). Recent evidence suggests that ANS is one of the key neural pathways for acupuncture signal transduction, which has attracted worldwide attention in the acupuncture field. Here, we reviewed the basic and clinical research published in PubMed over the past 20 years on the effects of acupuncture on ANS regulation and homeostasis maintenance. It was found that acupuncture effectively alleviates ANS dysfunction-associated symptoms in its indications, such as migraine, depression, insomnia, functional dyspepsia, functional constipation. Acupuncture stimulation on some specific acupoints activates sensory nerve fibers, the spinal cord, and the brain. Using information integration and efferents from a complex network of autonomic nuclei of the brain, such as the insular cortex (IC), prefrontal cortex, anterior cingulate cortex (ACC), amygdala (AMG), hypothalamus, periaqueductal gray (PAG), nucleus tractus solitarius (NTS), ventrolateral medulla (VLM), nucleus ambiguus (AMB), acupuncture alleviates visceral dysfunction, inflammation via efferent autonomic nerves, and relieves pain and pain affect. The modulating pattern of sympathetic and parasympathetic nerves is associated with acupuncture stimulation on specific acupoints, intervention parameters, and disease models, and the relationships among them require further exploration. In conclusion, ANS is one of the therapeutic targets for acupuncture and mediates acupuncture's actions, which restores homeostasis. A systemic study is needed to determine the rules and mechanisms underlying the effects of acupoint stimulation on corresponding organs mediated by specific central nervous networks and the efferent ANS.

Electroacupuncture Ameliorates Acute Myocardial Ischemia: A Potential Role of the Locus Coeruleus

The locus coeruleus (LC) is closely linked with cardiovascular disease. However, whether it mediates the alleviating effect of electroacupuncture (EA) on acute myocardial ischemia (AMI) remains unclear. A rat model of myocardial ischemia was established through occlusion of the left anterior descending coronary artery. Multichannel in vivo recording and other techniques were used to assess neurons in the LC, norepinephrine (NE) and dopamine (DA) levels in central and myocardial tissue, serum levels of inflammatory factors, and cardiac function. After induction of AMI, LC neuron activity increased and the central NE concentrations increased, while those of DA decreased. Moreover, the serum levels of high-sensitivity C-reactive protein (hs-CRP) increased, whereas those of interleukin-10 (IL-10) decreased. However, these effects were reversed by EA. Additionally, LC lesioning affected NE and DA levels in myocardial tissue and weakened the antimyocardial ischemic effect of EA. Collectively, our results indicated that LC is closely related to AMI and plays an important role in the antimyocardial ischemic effect of EA. This mechanism may be related to inhibition of LC neuron activity by EA, which inhibits the release of large amounts of hs-CRP and promotes that of IL-10 in the serum. Besides, after LC lesioning, EA may improve cardiac function by inhibiting the release of large amounts of NE and promoting the release of DA in myocardial tissue.

Effects of electroacupuncture combined with interleukin‑10 on chronic sinusitis in mice

Electroacupuncture (EA) has been documented as a form of therapy for chronic sinusitis (CRS). The present study aimed to assess the effects of EA combined with interleukin‑10 (IL‑10) overexpression on CRS in mice, and to investigate the associated mechanisms. A mouse model of CRS was established by the administration of ovalbumin (OVA), and overexpression of IL‑10 was induced using virus‑encoded IL‑10. The experimental groups were as follows: i) Control group; ii) OVA group; iii) OVA + EA group; iv) OVA + empty vector group; v) OVA + vector + EA group; vi) OVA + IL‑10 group; and vii) OVA + IL‑10 + EA group. Pathological changes and nasal mucus were analyzed using hematoxylin and eosin staining. Interferon‑γ (IFN‑γ) and IL‑10 were detected via reverse‑transcription quantitative PCR and western blot analyses. The pseudostratified epithelium of the mucosa of the nasal sinus was impaired following the induction of CRS. Treatment with EA and/or IL‑10 reversed the injury. Combination treatment with EA and IL‑10 induced synergistic effects. No infiltration of inflammatory cells was observed in the submucosa following EA and IL‑10 treatment. Compared with the control group, the expression of IFN‑γ and IL‑10 in the OVA group was reduced. By contrast, EA or the overexpression of IL‑10 inhibited this reduction. Furthermore, the combined application of EA and IL‑10 had a significantly more potent inhibitory effect on the reduction of IFN‑γ expression, but not IL‑10. Collectively, EA combined with IL‑10 induced specific effects on CRS in mice, likely through the upregulation of IFN‑γ and IL‑10. The current study presented mechanistic implications for the application of EA as an alternative treatment for CRS.