Electroacupuncture at GV20 and ST36 Exerts Neuroprotective Effects via the EPO-Mediated JAK2/STAT3 Pathway in Cerebral Ischemic Rats

Electroacupuncture Ameliorates Neuronal Injury by NLRP3/ASC/Caspase-1 Mediated Pyroptosis in Cerebral Ischemia-Reperfusion

NLRP3/ASC/Caspase-1 mediated pyroptosis is one of the important causes of cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture (EA) is widely used in clinical treatment of ischemic stroke. However, mechanism of EA on ischemic stroke remains unclear. Therefore, on basis of a previous work, this study used middle cerebral artery occlusion (MCAO) 2 h and then reperfusion 7 days in rats to simulate brain I/R process. EA with Bahui (GV20) and Zusanli (ST36) and VX-765 (a specific inhibitor of Caspase-1) was performed. In this study, we found that EA improved cerebral infarct size and neuronal damage, including ultrastructural injury, and ameliorated nitro/oxidative stress in cerebral I/R. Additionally, EA treatment significantly decreased ASC, Caspase-1, GSDMD, and IL-1β expression and VX-765 treatment significantly decreased NLRP3, Caspase-1, and IL-1β expression. This proved that EA can regulate NLRP3/ASC/Caspase-1 mediated pyroptosis, improve neuronal injury during cerebral I/R, and provide basic experimental data for clinical treatment.

Efficacy of electroacupuncture stimulating Shenmen (HT7), Baihui (GV20), Sanyinjiao (SP6) on spatial learning and memory deficits in rats with insomnia induced by para-chlorophenylalanine: a single acupoint combined acupoints

OBJECTIVE

To investiage the effect of electroacupuncture (EA) at a single acupoint of Shenmen (HT7), Baihui (GV20), Sanyinjiao (SP6) and at combined acupoints of Shenmen (HT7) and Baihui (GV20) and Sanyinjiao (SP6) on the PKA/CREB and BDNF/TrkB signaling, as well as neuroapoptosis and neurogenesis in hippocampus and elucidate the underlying mechanism of single and combined acupoints on ameliorating spatial learning and memory deficits in a rat model of primary insomnia.

METHODS

Primary insomnia was modeled by intraperitoneal injection of para-chlorophenylalanine (PCPA) once daily for 2 d. EA was applied at Shenmen (HT7), Baihui (GV20), Sanyinjiao (SP6), or Shenmen (HT7) + Baihui (GV20) + Sanyinjiao (SP6) (combined) for 30 min daily for 4 d. Spatial learning and memory function was evaluated by the Morris water maze (MWM) test. Protein expressions of hippocampal cAMP-dependent protein kinase (PKA)-Cβ, phosphorylated cAMP-responsive element-binding protein (p-CREB), brain-derived neurotrophic factor (BDNF), and tyrosine kinase receptor B (TrkB) were evaluated by Western blotting. Neuronal apoptosis in the hippocampus was detected with the transferase-mediated dUTP-X nick end labeling assay. Endogenous neurogenesis was examined with bromodeoxyuridine staining. The MWM test and hippocampal p-CREB, BDNF, and TrkB protein levels in the combined acupoints group were evaluated after the administration of a PKA-selective inhibitor (H89).

RESULTS

Spatial learning and memory were significantly impaired in rats with insomnia. The spatial learning deficits were ameliorated in the Shenmen (HT7), Baihui (GV20), Sanyinjiao (SP6), and combined groups; this improvement was significantly greater in the combined group than the single acupoint groups. The spatial memory impairment was improved in the combined, Baihui (GV20), and Shenmen (HT7) groups, but not the Sanyinjiao (SP6) group. The expressions of PKA-Cβ, p-CREB, BDNF, and TrkB were decreased in rats with insomnia. All these proteins were significantly upregulated in the combined group. PKA/p-CREB protein levels were elevated in the Baihui (GV20) and Shenmen (HT7) groups, whereas BDNF/TrkB expression was upregulated in the Sanyinjiao (SP6) group. The staining results showed significant attenuation of hippocampal cell apoptosis and increased numbers of proliferating cells in the combined group, whereas the single acupoint groups only showed decreased numbers of apoptotic cells. In the combined group, the PKA inhibitor reversed the improvement of spatial memory and upregulation of p-CREB expression caused by EA, but did not affect its activation of BDNF/TrkB signaling.

CONCLUSIONS

EA at the single acupoints Baihui (GV20), Shenmen (HT7), or Sanyinjiao (SP6) had an ameliorating effect on the spatial learning and memory deficits induced by insomnia. EA at combined acupoints exerted a synergistic effect on the improvements in spatial learning and memory impairment in rats with insomnia by upregulating the hippocampal PKA/CREB and BDNF/TrkB signaling, facilitating neurogenesis, and inhibiting neuronal apoptosis. These findings indicate that EA at combined acupoints [(Baihui (GV20), Shenmen (HT7), and Sanyinjiao (SP6)] achieves a more pronounced regulation of hippocampal neuroplasticity than EA at single acupoints, which may partly explain the underlying mechanisms by which EA at combined acupoints exerts a better ameliorative effect on the cognitive dysfunction caused by insomnia.

Feasibility of electroacupuncture at Baihui (GV20) and Zusanli (ST36) on survival with a favorable neurological outcome in patients with postcardiac arrest syndrome after in-hospital cardiac arrest: study protocol for a pilot randomized controlled trial

BACKGROUND

At present, even the first-line medication epinephrine still shows no evidence of a favourable neurological outcome in patients with sudden cardiac arrest (SCA). The high mortality of patients with postcardiac arrest syndrome (PCAS) can be attributed to brain injury, myocardial dysfunction, systemic ischaemia/reperfusion response, and persistent precipitating pathology. Targeted temperature management, the only clinically proven method in the treatment of PCAS, is still associated with a series of problems that have not been completely resolved. Acupuncture is a crucial therapy in traditional Chinese medicine. On the basis of the results of previous studies, we hypothesize that electroacupuncture (EA) might provide therapeutic benefits in the treatment of PCAS. This study will explore the feasibility of EA on SCA patients.

METHODS

This is a prospective pilot, randomized controlled clinical trial. Eligible patients with PCAS after in-hospital cardiac arrest (IHCA) admitted to our department will be randomly allocated to the control group or the EA group. Both groups will receive standard therapy according to American Heart Association guidelines for cardiopulmonary resuscitation. However, the EA group will also receive acupuncture at the Baihui acupoint (GV20) and Zusanli acupoint (ST36) with EA stimulation for 30 min using a dense-dispersed wave at frequencies of 20 and 100 Hz, a current intensity of less than 10 mA, and a pulse width of 0.5 ms. EA treatment will be administered for up to 14 days (until either discharge or death). The primary endpoint is survival with a favourable neurological outcome. The secondary endpoints are neurological scores, cardiac function parameters, and other clinical parameters, including Sequential Organ Failure Assessment (SOFA) scores and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, on days 0 to 28.

DISCUSSION

This study will provide crucial clinical evidence on the efficacy of EA in PCAS when used as an adjunctive treatment with AHA standard therapy.

TRIAL REGISTRATION

chictr.org.cn : ChiCTR2000040040. Registered on 19 November 2020. Retrospectively registered. http://www.chictr.org.cn/ .

Regulatory Effect of Electroacupuncture on Hypothalamic Serotonin and its Receptor in Rats with Cerebral Ischemia

BACKGROUND

Previous studies have shown that the neurological damage caused by middle cerebral artery occlusion (MCAO) is not only limited to local infarction but can also cause secondary damage in distant sites, such as the hypothalamus. 5-hydroxytryptamine (5-HT)/ 5-HT transporter (5-HTT) and 5-HT receptor 2A (5-HT2A) are important in the treatment of cerebrovascular diseases.

OBJECTIVE

This study aimed to study the effect of electroacupuncture (EA) on the expression of 5- HT, 5-HTT, and 5-HT2A in the hypothalamus of rats with ischemic brain injury and to explore the protective effect and potential mechanism of EA on the secondary injury of cerebral ischemia.

METHODS

Sprague-Dawley (SD) rats were randomly divided into three groups: sham group, model group, and EA group. The permanent middle cerebral artery occlusion (pMCAO) method was used to induce ischemic stroke in rats. In the EA group, the Baihui (GV20) and Zusanli (ST36) points were selected for treatment, which was administered once per day for two consecutive weeks. The neuroprotective effect of EA was evaluated by nerve defect function scores and Nissl staining. The content of 5-HT in hypothalamus was detected by enzyme linked immunosorbent assay (ELISA), and the expression of 5-HTT and 5-HT2A were detected by Western blot.

RESULTS

Compared with that in the sham group, the nerve defect function score in the model group rats was significantly increased, the hypothalamus tissue showed obvious nerve damage, the levels of 5-HT and the expression of 5-HTT were significantly reduced, and the expression of 5-HT2A was significantly increased. After 2 weeks of EA treatment, the nerve defect function scores of pMCAO rats were significantly reduced, the hypothalamic nerve injury was significantly reduced, the levels of 5-HT and the expression of 5-HTT were significantly increased, and the expression of 5-HT2A was significantly decreased.

CONCLUSION

EA has a certain therapeutic effect on hypothalamic injury secondary to permanent cerebral ischemia, and its potential mechanism may be closely related to the upregulation of 5-HT and 5-HTT expression and the downregulation of 5-HT2A expression.

Electroacupuncture inhibits the expression of HMGB1/RAGE and alleviates injury to the primary motor cortex in rats with cerebral ischemia

Background

The high-mobility group box 1 (HMGB1)/receptor for advanced glycation end products (RAGE) signaling pathway holds promise as a potential therapeutic target for ischemic brain injury. The effects of FPS-ZM1 and electroacupuncture (EA) on activation of the HMGB1/RAGE signaling pathway after cerebral ischemia remain uncertain.

Methods

Middle cerebral artery occlusion (MCAO) model was established. Neurological function was assessed using Longa scores. Nissl staining was used to observe the morphology of neurons. The expression levels of HMGB1 and RAGE were assayed with immunofluorescence staining and western blot.

Results

The results showed that EA and FPS-ZM1 could reduce the neural function score and neurons cell injury in cerebral ischemia rats by inhibiting the expression of HMGB1 and RAGE in primary motor cortex (M1) region. In addition, EA combined with FPS-ZM1 had a better therapeutic effect.

Conclusions

The HMGB1/RAGE pathway could be activated after cerebral ischemia. Both EA and FPS-ZM1 improved neurological deficits and attenuated neuronal damage in rats. They had synergistic effects. These interventions were observed to mitigate brain damage by suppressing the activation of HMGB1/RAGE.

Electroacupuncture Improves Cerebral Ischemic Injury by Enhancing the EPO-JAK2-STAT5 Pathway in Rats

OBJECTIVE

Clinically, electroacupuncture (EA) improves cerebral ischemic injury, but its mechanism remains unknown. The aim of this study was to confirm the protective effects of EA on focal cerebral ischemia (FCI)-induced injury and the possible mechanism.

METHODS

Sprague-Dawley (SD) rats served as the FCI model and were divided into the sham, model, EA, AG490 and EA+AG490 groups. Rats in the EA and EA+AG490 groups were acupunctured at the Baihui (GV20) and Dazhui (GV14) acupoints, and those in the AG490 and EA+AG490 groups were administered an intracerebroventricular injection of AG490 (a Janus-tyrosine kinase-2 (JAK-2) phosphorylation inhibitor). Neurological deficits and morphological changes in the ischemic cortex were observed through neurological deficit scoring and HE staining, respectively, and neuronal apoptosis was examined using the TUNEL assay. Transmission electron microscopy was used to observe neuronal ultrastructure, and HIF-1α, erythropoietin (EPO), phosphorylated (p)-JAK2, p-STAT5, HSP70, Bax and Bcl-2 expression was measured by RT-PCR and immunohistochemistry.

RESULTS

FCI model rats showed obvious neurological deficits and neuronal apoptosis compared with sham rats. EA alleviated FCI-induced neurological deficits, improved neuronal ultrastructure, reduced neuronal apoptosis, and induced HIF-1α, EPO, p-JAK2, p-STAT5, HSP70 and Bcl-2 expression in a time-dependent manner. In contrast, AG490 treatment impaired the effects of EA on neurological deficits, neuronal apoptosis and HIF-1α, EPO, p-JAK2, p-STAT5, HSP70, Bax and Bcl-2 expression.

CONCLUSION

EA at GV20 and GV14 could improve neurological deficits and reduce neuronal apoptosis, thereby improving FCI-induced injury, which may be related to enhancing the EPO-JAK2-STAT5 pathway.

Electroacupuncture Improves Cognitive Function in Senescence-Accelerated P8 (SAMP8) Mice via the NLRP3/Caspase-1 Pathway

Background. Clinically, electroacupuncture (EA) is the most common therapy for aging-related cognitive impairment (CI). However, the underlying pathomechanism remains unidentified. The aims of this study were to observe the effect of EA on cognitive function and explore the potential mechanism by which EA acts on the NLRP3/caspase-1 signaling pathway. Main Methods. Thirty male SAMP8 mice were randomly divided into the model, the 2 Hz EA and 10 Hz EA groups. Ten male SAMR1 mice were assigned to the control group. Cognitive function was assessed through the Morris water maze test. Hippocampal morphology and cell death were observed by HE and TUNEL staining, respectively. The serum IL-1β, IL-6, IL-18, and TNF-α levels were measured by ELISA. Hippocampal NLRP3, ASC, caspase-1, GSDM-D, IL-1β, IL-18, Aβ, and tau proteins were detected by Western blotting. Key Findings. Cognitive function, hippocampal morphology, and TUNEL-positive cell counts were improved by both EA frequencies. The serum IL-1β, IL-6, IL-18, and TNF-α levels were decreased by EA treatment. However, 10 Hz EA reduced the number of TUNEL-positive cells in the CA1 region and serum IL-1β and IL-6 levels more effectively than 2 Hz EA. NLRP3/caspase-1 pathway-related proteins were significantly downregulated by EA, but 2 Hz EA did not effectively reduce ASC protein expression. Interestingly, both EA frequencies failed to reduce the expression of Aβ and tau proteins. Significance. The effects of 10 Hz EA at the GV20 and ST36 acupoints on the NLRP3/caspase-1 signaling pathway may be a mechanism by which this treatment relieves aging-related CI in mice.

Kappa opioid receptor agonists improve postoperative cognitive dysfunction in rats via the JAK2/STAT3 signaling pathway

Postoperative cognitive dysfunction (POCD) is a common and well‑known complication following surgery, particularly cardiopulmonary bypass (CPB) surgery. There are currently no suitable treatments for POCD, which is associated with increased illness and mortality rates. The present study aimed to identify a novel treatment for POCD. The protective effect of kappa opioid receptor (KOR) agonists on POCD in rats following CPB was determined and the regulatory mechanism of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway was examined. The rats were randomly divided into five groups: Sham operation (Sham group), CPB operation (CPB group), KOR agonist + CPB (K group), KOR agonist + norbinaltorphimine (nor‑BNI) + CPB (NK group), and KOR agonist + JAK2‑STAT3 specific pathway inhibitor + CPB (AG group). A water maze test and neurological function scores were used to evaluate POCD. Hematoxylin and eosin staining was used to observe hippocampal neurons. ELISA was used to detect the levels of inflammatory factors, oxidative stress factors and brain injury markers. Immunofluorescence was used to visualize the neurons. TUNEL staining and western blotting were used to detect neuronal apoptosis, and western blotting was also used to detect JAK2/STAT3 pathway‑related proteins. The KOR agonists significantly improved POCD. S‑100β and NSE detection revealed that KOR agonists alleviated brain damage in CPB rats, and this result was reversed by KOR antagonists. The KOR agonists led to a significantly reduced inflammatory response and oxidative stress, as determined by ELISA detection, and attenuated hippocampal neuronal apoptosis, as revealed by TUNEL staining and western blotting, compared with the results in the CPB group. Finally, the KOR agonists inhibited the expression levels of phosphorylated (p‑)JAK2 and p‑STAT3, rather than total JAK2 and STAT3, compared with levels in the CPB group. Taken together, KOR agonists improved POCD in rats with CPB by inhibiting the JAK2/STAT3 signaling pathway.

Electroacupuncture ameliorates neuronal injury by Pink1/Parkin-mediated mitophagy clearance in cerebral ischemia-reperfusion

The accumulation of dysfunctional mitochondria induced by the impairment of the autophagy-lysosome pathway (ALP), especially mitophagy is an important cause of cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture (EA) exerts remarkable effects in treating ischemic stroke; however, the detailed mechanism remains unclear. In this study, rats were treated with mitochondrial permeability transition pore (mPTP) opening inhibitor, peroxynitrite (ONOO^-) scavenger, or selective inhibitor of mitophagy activation during 2-h middle cerebral artery occlusion (MCAO) followed by 24 h of reperfusion in combination with EA treatment. RNA-Seq analysis showed that EA treatment in cerebral I/R was linked to the autophagosome, the PI3K/Akt signaling pathway and metabolic pathways. We found that I/R resulted in significantly mitochondrial function impairments including decreased mitochondrial membrane potential (MMP) and ATP levels, aggregation of damaged mitochondria, excessive nitro/oxidative stress, PI3K/Akt/mTOR-mediated ALP dysfunction and deficiency of Pink1/Parkin-mediated mitophagy clearance. The treatment with EA, cyclosporine-A (CsA, a potent inhibitor of mPTP opening) or FeTMPyP (a type of ONOO^- scavenger) could significantly increase MMP and/or ATP levels, improve mitochondrial function and decrease neuronal injury. At the same time, EA also improved ALP dysfunction and the deficiency of mitophagy clearance; however, mitochondrial division inhibitor-1 (Mdivi-1, a selective inhibitor of mitophagy activation) blocked mitophagy clearance and aggravated neuronal injury. Taken together, EA ameliorates nitro/oxidative stress-induced mitochondrial functional damage and decreases the accumulation of damaged mitochondria via Pink1/Parkin-mediated mitophagy clearance to protect cells against neuronal injury in cerebral I/R.

Acupuncture Rescues Cognitive Impairment and Upregulates Dopamine-β-Hydroxylase Expression in Chronic Cerebral Hypoperfusion Rats

Alteration of dopamine (DA) and noradrenaline (NA) contributes to cognitive function. Acupuncture has been shown to affect DA and NA in chronic cerebral hypoperfusion (CCH) rats. However, the effect of acupuncture on DA-β-hydroxylase (DBH), the biosynthetic enzyme of NA, remains unknown. In CCH rats we established chronic hypoperfusion by bilateral common carotid artery occlusion (two-vessel occlusion, 2VO) and treated them with acupuncture. Acupuncture displayed beneficial effects on hippocampus-dependent memory impairments, including nonspatial and spatial memory. That is also reflected in hippocampus long-term-potentiation (LTP). Moreover, DBH expression in the hippocampus and DBH activity in cerebrospinal fluid were upregulated after acupuncture treatment. In conclusion, these in vivo findings suggest that acupuncture exerts a therapeutic effect on hippocampus-dependent memory and hippocampus LTP in CCH rats, which may be partially related to the modulation of DBH in the hippocampus.