Yu-Xue Zhao

Objective: It is well established that endogenous and exogenous corticotrophin-releasing factor (CRF) stimulates colonic motility in rodents. Electroacupuncture (EA) has shown promise in relieving stress responses and alleviating colonic dysmotility, but less is known about its underlying mechanism of action in this context. This study was designed to elucidate the effects of EA on colorectal dysfunction in a rat model of stress and to clarify the underlying mechanism. Methods: A rat model of stress was induced using exogenous CRF. Colonic propulsion was evaluated by the bead latency test, and colorectal motility was recorded in vivo by implanting a manometric capsule into the colorectal lumen. To clarify the role of CRF receptors type 1 and 2 on stress-induced colonic dysfunction, corresponding selective antagonists (CP-154526 and Astressin 2B, respectively) were administered accordingly. Western blot analysis was used to detect protein expression of CRF and its receptors in the hypothalamus and colorectum. Results: CRF–induced stress significantly accelerated colonic motility. EA treatment alleviated colonic motor dysfunction and reduced colonic propulsion. CP-154526, but not Astressin 2B, reversed CRF–induced colonic dysmotility, suggesting an essential role of CRF receptor type 1 in stress-induced colonic motor disorders. EA treatment resulted in an inhibition of the protein overexpression of CRF receptor type 1 in both the hypothalamus and colorectum in this rat model of stress. Conclusions: EA ameliorated stress-induced colonic dysmotility, most likely through regulation of central and peripheral expression of CRF receptor type 1.

Paclitaxel-induced peripheral neuropathic pain (PIPNP) is a common and debilitating adverse effect of chemotherapy, with limited effective treatments. Electroacupuncture (EA) has demonstrated analgesic potential in various pain models, but its efficacy and mechanisms in PIPNP remain incompletely understood. This study aimed to evaluate the analgesic effect of EA in a murine model of PIPNP and investigate whether its mechanism involves modulation of the TLR4/P2X7-NLRP3 signaling pathway. A PIPNP model was established in male C57BL/6 J mice by intraperitoneal injection of paclitaxel (cumulative dose 8 mg/kg). Mice were randomly divided into control, PIPNP model, PIPNP with EA treatment at different intensities (0.5, 1.0, and 2.0 mA), and sham EA groups. Mechanical allodynia and thermal hyperalgesia were assessed using von Frey filaments and hot plate tests, respectively. Immunofluorescence staining and western blotting were employed to analyze the expression of pain-related neurotransmitters (substance P, CGRP, p75) and key components of the TLR4/P2X7-NLRP3 signaling pathway in plantar tissues, dorsal root ganglia (DRG), and spinal cord. EA treatment, particularly at 1.0 mA, significantly alleviated paclitaxel-induced mechanical allodynia and thermal hyperalgesia. Paclitaxel administration upregulated substance P, CGRP, and p75 in plantar tissues and activated the TLR4/P2X7-NLRP3 signaling pathway in DRG and spinal cord, as evidenced by increased expression of TLR4, P2X7, NLRP3, NF-κB, IL-1β, and IL-18. EA intervention markedly suppressed these changes, indicating its role in inhibiting neuroinflammation and modulating pain-related signaling. EA exerts analgesic effects in paclitaxel-induced neuropathic pain by attenuating the activation of the TLR4/P2X7-NLRP3 signaling pathway and reducing the expression of pain-related neurotransmitters.

Paclitaxel (PTX) treatment induces a pathological pain state that is often associated with neuroinflammation in the central nervous system. The available interventions for PTX-induced pathological pain encounter adverse effects and limited efficacies. Recent studies have shown the significant effectiveness of Electroacupuncture (EA) in pain management as a simple and safe alternative medical treatment. Here, we evaluated the analgesic effect of EA on pain behaviors in PTX-treated rats and investigated its potential analgesic mechanisms. In this study, a pathological pain model was established in SD rats via intraperitoneal ( i.p .) injection of PTX. EA or Sham EA treatments were applied every other day for PTX-treated rats. Pain behaviors of mechanical allodynia and thermal hyperalgesia in rats were measured, followed by analysis of the spinal cord tissue via using molecular biology methods. Here, we show that EA treatment is capable to alleviate PTX-induced mechanical allodynia and thermal hyperalgesia in rats. In addition, EA regulated the abnormal protein expression of astrocytes, microglia, neurons, TLR4-MyD88/TRIF signaling pathway and cytokines in the lumbar spinal cord of PTX-treated rats. Furthermore, we investigated the spinal co-expressions of TLR4 in astrocytes, microglia, and neurons respectively in rats and the regulatory effect of EA on TLR4 and cells mentioned above. In summary, EA shows analgesic properties as it ameliorates PTX-induced mechanical allodynia and thermal hyperalgesia probably by reducing central neuroinflammation. Therefore, we consider EA as a potential therapeutic candidate for the treatment of PTX-induced pathologic pain. Notably, this study provides the first morphological evidence that EA may concurrently influence TLR4-mediated neuroimmune interactions across multiple spinal cell types, suggesting a potential central mechanism distinct from previously reported peripheral actions.

Pain is a major symptom in cancer patients, and cancer-induced bone pain (CIBP) is the most common type of moderate and severe cancer-related pain. The current available analgesic treatments for CIBP have adverse effects as well as limited therapeutic effects. Acupuncture is proved effective in pain management as a safe alternative therapy. We evaluated the analgesic effect of acupuncture in treatment of cancer pain and try to explore the underlying analgesic mechanisms. Nude mice were inoculated with cancer cells into the left distal femur to establish cancer pain model. Electroacupuncture (EA) treatment was applied for the xenograft animals. Pain behaviors of mice were evaluated, followed by the detections of neuropeptide-related and inflammation-related indicators in peripheral and central levels. EA treatment alleviated cancer-induced pain behaviors covering mechanical allodynia, thermal hyperalgesia and spontaneous pain, and also down-regulated immunofluorescence expressions of neuropeptide CGRP and p75 in the skin of affected plantar area in xenograft mice, and inhibited expressions of overexpressed neuropeptide-related and inflammation-related protein in the lumbar spinal cord of xenograft mice. Overall, our findings suggest that EA treatment ameliorated cancer-induced pain behaviors in the mouse xenograft model of cancer pain, possibly through inhibiting the expressions of neuropeptide-related and inflammation-related protein in central level following tumor cell xenografts.

Objective. The objective is to observe the synergistic and attenuating effect of electroacupuncture (EA) on aconitine (ACO) in improving heart failure (HF) and to explore its underlying mechanism for calcium regulation. Methods. Twenty-four male Sprague-Dawley rats were randomly divided into four groups: normal control (NC) (n=6), HF(n=6), ACO (n=6), and ACO+EA (n=6). The maximum rates of left ventricular pressure rising and declining (±dp/dtmax), arrhythmia, the left ventricular systolic pressure (LVSP), ejection fraction (LVEF), and fractional shortening (LVFS) were measured by physiological recorder and ultrasound, respectively. Protein expressions of sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase (SERCA2a), phospholamban (PLB), and Na⁺-Ca²⁺ exchange (NCX1) in the left ventricle tissue were detected by fluorescence immunoblotting. Results. Compared with the NC group, LVSP, ±dp/dtmax, LVEF, and LVFS were decreased in the HF group; compared with the HF group, LVSP, ±dp/dtmax, LVEF, and LVFS were significantly increased in the ACO+EA group. Compared with the ACO group, the incidence and the degree of arrhythmia were significantly reduced in the ACO+EA group. Compared with the NC group, the activity of SERCA2a was decreased, and the expression of PLB and NCX1 was enhanced in the HF group; compared with the HF group and ACO group, the activity of SERCA2a was increased, and the expression of PLB and NCX1 was significantly attenuated in the ACO+EA group. Conclusions. EA plays a synergistic and attenuated role in ACO improving HF, and the mechanism may be related to the enhancement of the SERCA2a activity and the decrease of the expression of PLB and NCX1 in cardiomyocytes.

Paclitaxel-induced peripheral neuropathy (PIPN) is a common and intractable side effect of the conventional chemotherapeutic agent paclitaxel. Acupuncture has been reported as an effective alternative therapy in treatment of PIPN in both basic studies and clinical trials. However, there is a lack of comprehensive surveys to summarize the action of acupuncture in management of PIPN. In this review, we briefly demonstrate the basic pathology of PIPN, which includes the activation of ion channels, mitochondrial dysfunction, disruption of axonal transport and also neuro-inflammatory involvement. Meanwhile, we review both the clinical and basic studies as an emphasis to give a general overview of the therapeutic effect of acupuncture against PIPN. Finally, we summarize the current known mechanisms underlying the action of acupuncture against PIPN mainly at peripheral and spinal levels, which include various neurotransmitters, multiple receptors, different types of enzymes and molecules. In conclusion, acupuncture could be considered as a potential alternative therapy in treatment of PIPN, and further clinical and experimental studies are called for in the future.

Background: Central injection of corticotrophin-releasing factor (CRF) mimics the effect of stress on gastrointestinal (GI) responses, including inhibition of GI motility. This study was designed to explore the effects of electroacupuncture (EA) on disordered jejunal motility in a rat model of stress induced by intracisternal (IC) injection of CRF. Methods: A stress model was established by IC injection of CRF in Sprague–Dawley rats. GI motility was evaluated by assessing gastric emptying (GE), gastrointestinal transit (GIT) and jejunal motility in vivo. EA was performed at ST36. The functional roles of CRF receptor subtype 1 and subtype 2 (CRFr1 and CRFr2) were examined by IC administration of the corresponding selective CRF antagonists. Protein expression of CRFr1 and CRFr2 in the hypothalamus and jejunum was detected by Western blotting. Results: IC injection of CRF significantly inhibited GE, GIT and jejunal motility. EA treatment remarkably improved the disturbed GI motility. Intriguingly, the disordered jejunal motility induced by central CRF was abolished by IC injection of a selective CRFr2 antagonist, indicating the essential role of central CRFr2 in mediating the stress-induced jejunal motor disorder. EA at ST36 decreased central and peripheral expression of CRFr2, which might be one of the potential mechanisms underlying the beneficial effect of EA on jejunal dysmotility in this rat model of stress. Conclusion: This study suggested that EA at ST36 could ameliorate disordered jejunal motility induced by stress, and that this might be associated with the down-regulation of CRFr2.

Background and Purpose: Neuropathic pain is a major side-effect of paclitaxel (PTX) chemotherapy. Although the precise mechanisms responsible for this pain are unclear, the activation of neuroglia and upregulation of the TLR4/NF-κB pathway are known to be involved. In this study, we determined whether electroacupuncture (EA) could limit mechanical hypersensitivity resulting from the chemotherapeutic drug PTX in rats, and investigated the potential mechanisms involved. Methods: Rats intraperitoneally received a cumulative dose of 8 mg/kg PTX (2 mg/kg per day) or vehicle control on alternate days (day 0, 2, 4 and 6). EA treatment (10 Hz, 1 mA) was applied at bilateral ST36 acupoints in rats once every other day on days 0– 14. For sham EA, needles were inserted at ST36 acupoints without electrical stimulation. Mechanical allodynia was measured by mechanical withdrawal latency (MWL) of paws to a mechanical stimulus every 2 days. Protein expression of TLR4 and NF-κB p65, as well as TMEM119 and GFAP (indicators of microglia and astrocytes, respectively) in spinal cord was quantified by Western blot analysis. Levels of inflammatory cytokines IL-1β and TNF-α in spinal cord and serum were detected by ELISA. Results: Mechanical allodynia induced by PTX in both paws (right and left) of rats was significantly attenuated by EA but not sham EA treatment. In addition, EA, but not sham EA, inhibited the activation of both microglia (TMEM119) and astrocytes (GFAP) in lumbar spinal cord. Moreover, Western blot analysis revealed that protein expression of TLR4 and NF-κB in spinal cord was suppressed by EA but not sham EA treatment. PTX significantly increased inflammatory cytokines in spinal cord and serum, which were ameliorated by EA treatment but not by sham EA. Conclusion: These results indicate that EA treatment attenuates PTX-induced mechanical allodynia. The putative mechanism corroborating this finding could be related to the suppression of activated microglia and astrocytes in spinal cord, as well as the inhibition of the activated TLR4/NF-κB signaling pathway by EA treatment.

The previous study showed that the cardiac arrhythmias induced by myocardial ischemia and reperfusion were attenuated by the pretreatment of acupuncture; however, the related mechanism is not understood. The present study was therefore designed to determine whether intracellular Ca2+ ([Ca2+]i) and connexin 43 (Cx43) are involved in the mediation of the anti-arrhythmic effect of electro-acupuncture (EA) pretreatment in the rats subjected to simulative global ischemia and reperfusion (SGIR). SGIR was made in the isolated heart by a low flow perfusion followed by a flow restoration. Four groups of animals are involved in the present study, including normal control group, SGIR group, EA group and EA plus 18 beta-glycyrrhetinic acid (EAG) group. For EA pretreatment, bilateral Neiguan acupoints (PC6) of the rats were stimulated for 30 min once a day in 3 consecutive days. Cx43 antagonist was given to the rats in EAG group 30 minutes before the EA pretreatment. The resting [Ca2+]i concentration, calcium oscillation, the contents of total Cx43 and non-phosphrylated Cx43 and arrhythmia score were compared among different groups. In EA group, the arrhythmic score, the resting [Ca2+]i concentration and the number of [Ca2+]i oscillations were all significantly less than those in SGIR group (all P < 0.05), and interestingly, after EA pretreatment, the contents of nonphosphated Cx43 in the EA group were significantly lower than that in SGIR group respectively (P < 0.05). However, when the rats were treated with Cx43 antagonist prior to the EA pretreatment, the protection effects induced by EA pretreatment were reversed. The results showed that EA pretreatment could produce anti-arrhythmic effect in the rats subjected to SGIR. The anti-arrhythmic effect of EA pretreatment may be due at least partially to the inhibition of SGIR-induced calcium overload and [Ca2+]i oscillations, reduction of non-phosphorylated Cx43 and the enhancement of the corresponding phosphorylated Cx43 in the cardiac cells.