Electroacupuncture diminishes P2X_2 and P2X_3 purinergic receptor expression in dorsal root ganglia of rats with visceral hypersensitivity

Electroacupuncture at Shangjuxu （ST37） and Tianshu （ST25） can improve visceral hypersensitivity in rats. Colorectal distension was used to establish a rat model of chronic visceral hypersensitivity. Immunohistochemistry was used to detect P2X2 and P2X3 receptor expression in dorsal root ganglia from rats with chronic visceral hypersensitivity. Results demonstrated that abdominal withdrawal reflex scores obviously increased following establishment of the model, indicating visceral hypersensitivity. Simultaneously, P2X2 and P2X3 receptor expression increased in dorsal root ganglia. After bilateral electroacupuncture at Shangjuxu and Tianshu, abdominal withdrawal reflex scores and P2X2 and P2X3 receptor expression decreased in rats with visceral hypersensitivity. These results indicated that electroacupuncture treatment improved visceral hypersensitivity in rats with irritable bowel syndrome by reducing P2X2 and P2X3 receptor expression in dorsal root ganglia.

Ecto-F_1-ATPase: A moonlighting protein complex and an unexpected apoA-I receptor

Mitochondrial ATP synthase has been recently detected at the surface of different cell types, where it is a high affinity receptor for apoA-I, the major protein component in high density lipoproteins (HDL). Cell surface ATP synthase (namely ecto-F1-ATPase) expression is related to different biological effects, such as regulation of HDL uptake by hepatocytes, endothelial cell proliferation or antitumor activity of Vγ9/Vδ2 T lymphocytes. This paper reviews the recently discovered functions and regulations of ecto-F1-ATPase. Particularly, the role of the F1-ATPase pathway(s) in HDL-cholesterol uptake and apoA-Imediated endothelial protection suggests its potential importance in reverse cholesterol transport and its regulation might represent a potential therapeutic target for HDL-related therapy for cardiovascular diseases. Therefore, it is timely for us to better understand how this ecto-enzyme and downstream pathways are regulated and to develop pharmacologic interventions.

THE CORRELATIVITY ANALYSIS OF SIX METHODS OF DETECTING APOPTOSIS

The aim of this study was to compare six methods of detecting apoptosis induced by extracellular adenosine triphosphate (ATP) in human leukemic lymphocytes with purinergic P2Z receptors.These methods used were electron microscopy(EM), detection of internucleosomal DNA fragmentation by agarose gel electrophoresis, autoradiographic analysis of DNA fragmentation, in situ labeling of DNA strand breaks with fluorescein dUTP and exogenous terminal deoxynucleotidyl transferase (TUNEL), quantitation of 3 ends of DNA breaks by labeling with α 32 PdCTP(TdT assay), and quantitation of apoptotic cells with fluorescein annexin V using flow cytometry(FCA).We found EM and detection of DNA ladder pattern by agarose gel electrophoresis to be specific,but lacking in sensitivity. The combination of autoradiography and gel electrophoresis gave an increase in sensitivity of at least 50 fold although, of all the methods, the TdT assay was shown to be most sensitive. The four methods for quantifying apoptosis EM, FCA, TUNEL and TdT assay proved to be reliable and gave statistically similar results on apoptotic lymphocytes. These observations indicate it is essential to combine specific, sensitive and quantitative techniques in detecting apoptosis.

Adenosine triphosphate mediates the pain tolerance effect of manual acupuncture at Zusanli(ST36) in mice

OBJECTIVE:To investigate the mechanisms behind the effects of acupuncture in Traditional Chinese Medicine,we delved into the adenosine triphosphate/peripheral purinergic P2X receptor 3(ATP/P2X3)receptor signaling system as an indicator of the body's energy state,commonly referred to as"Qi".METHODS:The tail-flick test was utilized to explore the impact of acupuncture on pain tolerance threshold(PTT)in mice,while also assessing adenosine(ADO)levels and adenylate energy charge(EC)at Zusanli(ST36).The study further investigated the dose-dependent effects of acupuncture on PTT and ADO levels at Zusanli(ST36).To shed light on the underlying mechanisms of acupuncture's effects,the study examined the impact of ATP,a P2X3 receptor antagonist,and adenosine disodium on PTT following acupuncture administration.RESULTS:Acupuncture at Zusanli(ST36)led to significant improvements in PTT in mice,with the most effective interventions being twirling for 2 min and needle retention for 28 min.These interventions also resulted in significant increases in ATP levels.The effects of acupuncture were further augmented by administration of different doses of ATP at Zusanli(ST36),and pretreatment with a P2X3 receptor antagonist decreased PTT.Adenylate EC peaked at 30 min after intraperitoneal injection of ATP,and pretreatment with various doses of i.p.ATP 30 min prior to acupuncture increased PTT in a dose-dependent manner.Additionally,pretreatment with an i.p.or intramuscular injection of adenosine disodium enhanced the effects of acupuncture.CONCLUSION:This research provides compelling evidence that ATP is involved in the regulation of PTT through acupuncture,revealing new avenues for achieving enhanced clinical outcomes.

Effects of moxibustion on the P2X7R/STAT3/VEGF pathway in rats with colitis-associated colon cancer

Objective:To observe the effects of herb-partitioned moxibustion and ginger-partitioned moxibustion on the growth of colon tumors in rats with colitis-associated colon cancer(CACC),and explore the mechanism of moxibustion intervening CACC through the purinergic receptor P2X ligand-gated ion channel 7(P2X7R)/signal transducer and activator of transcription 3(STAT3)/vascular endothelial growth factor(VEGF)pathway.Methods:A total of 26 male Sprague-Dawley rats were selected.According to the random number table method,6 rats were selected as the normal group.The remaining 20 rats were injected intraperitoneally with azoxymethane(AOM)combined with oral dextran sodium sulfate(DSS)to prepare the CACC model.After the model was successfully established,2 rats were randomly selected for model identification.The remaining 18 rats which were successfully modeled were randomly divided into a model group,a herb-partitioned moxibustion group and a ginger-partitioned moxibustion group,with 6 rats in each group.Moxibustion intervention was performed in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group at Qihai(CV 6)and bilateral Tianshu(ST 25).Moxibustion was performed twice at each point each time,once a day,at a 1-day interval after 6 consecutive interventions,for a total of 30 interventions.After intervention,the colon tumor load,pathological change and histopathological score were observed.Immunohistochemistry was used to detect the expressions of VEGF,P2X7R,phospho-STAT3(p-STAT3),and nuclear factor-kappa B p65(NF-κB p65)proteins in rat colon tissue.Western blot was used to detect the levels of p-STAT3 and NF-κB p65 proteins in rat colon tissue.Results:Compared with the normal group,the colon tumor load and histopathological score in the model group were significantly increased(both P<0.001),and different grades of dysplasia were observed in colon tissue from the model group,reaching the degree of adenocarcinoma;the expression level of P2X7R protein in colon tissue was significantly decreased(P<0.001),and the expression levels of p-STAT3,NF-κB p65 and VEGF proteins were significantly increased(all P<0.001)in the model group.Compared with the model group,the colon tumor load,colon histopathological score and the levels of p-STAT3,NF-κB p65 and VEGF proteins in colon tissue were significantly decreased(all P<0.05)in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group while the expression levels of P2X7R protein in colon tissue were significantly increased(both P<0.05).Conclusion:Both herb-partitioned moxibustion and ginger-partitioned moxibustion can reduce the colon tumor load in CACC rats and delay the progression of colon adenomas.The mechanism may be mediated by the P2X7R/STAT3 pathway to inhibit STAT3 phosphorylation,thereby reducing VEGF protein expression.

Effect of electroacupuncture on inflammatory signal expression in local tissues of rats with chronic pelvic pain syndrome based on purinergic 2X7 receptor/NOD-like receptor pyrin domaincontaining 3 signal pathway

OBJECTIVES: To study the expression of inflammatory signal in local prostate tissue of chronic pelvic pain syndrome(CPPS) rats by electroacupuncture(EA) of Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6), and to explore the possible mechanism of anti-inflammatory and analgesic effects of EA. METHODS : A total of 36 Sprague-Dawley male rats were randomly divided into three groups: control, model and EA(n=12 rats/group). The CPPS model was made by injection of CFA into ventral lobes of the prostate(0.1 m L). Electric acupuncture apparatus was applied to stimulate Guanyuan(CV4), Zhongji(CV3), bilateral Huiyang(BL35) and Sanyinjiao(SP6) acupoints in EA group. The general condition of rats was observed and the prostate index(PI) was calculated. The thermal pain threshold was collected after each therapeutic course. Histopathological changes of the prostate tissue were examined by hematoxylin-eosin staining method. The expression levels of tumor necrosis factor α(TNF-α), interleukin-1β(IL-1β) and prostaglandin E2(PGE2) in prostatic homogenates were measured by enzyme linked immunosorbent assay(ELISA). Moreover, the expression levels of purinergic 2X7 receptor(P2X7R), NOD-like receptor pyrin domain-containing 3(NLRP3), caspase-1 and interleukin-18(IL-18) m RNA were quantified by quantitative real-time polymerase chain reaction. RESULTS: Compared with control group, the PI of rats increased, and the thermal pain threshold decreased significantly in model group. The morphological structure of prostate tissues of rats in model group was severely damaged with a large number of inflammatory cells infiltration. Additionally, the levels of TNF-α, IL-1β and PGE2 were higher, and the expressions of P2X7R, NLRP3, caspase-1 and IL-18 m RNA were higher than those in control group. After EA treatment, the PI was significantly decreased, the thermal pain threshold was significantly increased, and the tissue damage was significantly improved. The expressions of inflammatory cytokines were lower in EA group, and expression of P2X7R/NLRP3 pathway was down-regulated. CONCLUSION: The effect of EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can improve inflammation and pain symptoms of CPPS rats induced by Complete Freund’s adjuvant(CFA). This suggests that EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can produce antiinflammatory analgesia effect by preventing the activation of P2X7R/NLRP3 signal pathway, inhibit the release of inflammatory cytokines in CPPS rats, which may provide a putative novel target for the treatment of CPPS.

Regulatory effect of mild moxibustion on P2X3 receptors in spinal cord,anterior cingulate cortex and thalamic ventral posterolateral nucleus of rats with IBS visceral hyperalgesia

Objective To observe the therapeutic effect of mild moxibustion on irritable bowel syndrome(IBS)visceral hyperalgesia model rats and its regulatory effect on P2X3 receptors in the spinal cord,anterior cingutate cortex(ACC)and thalamic ventral posterolateral nucleus(VPL).Methods Thirty 8-day-old newborn rats were randomly divided into a normal group(n=6)and a modeling group(n=24)according to the completely random number table method.Rats in the normal group were bred routinely,and those in the modeling group were subjected to preparing IBS chronic visceral hyperalgesia model using colorectal distention(CRD)in stimulation method.Rats successfully modelled were re-divided into a model group,a mild moxibustion group,a P2X3 receptor antagonist group,and a normal saline group according to the completely random number table method with 6 rats in each group.Rats in each group received corresponding interventions from the 37-day old,once a day for 7 consecutive days.Immunohistochemistry and Western blot assays were used to detect P2X3 protein expressions in the spinal cord,ACC and VPL of rats.Results Under different intensities of CRD stimulation,the abdominal withdrawal reflex(AWR)scores of the model group were significantly increased versus the normal group(all P<0.05);the AWR scores of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group(all P<0.01).The P2X3 protein expressions in rat spinal cord,ACC and VPL tissues of the model group were significantly increased versus the normal group(all P<0.01);the P2X3 protein expressions in rat spinal cord,ACC and VPL tissues of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group(all P<0.01).Conclusion Mild moxibustion can inhibit the P2X3 receptor expressions in the spinal cord,ACC,and VPL tissues of IBS visceral hyperalgesia model rats,which may be the mechanism of mild moxibustion in relieving the central sensitization of rats with IBS visceral hyperalgesia.