Electroacupuncture-induced neuroprotection against focal cerebral ischemia in the rat is mediated by adenosine A1 receptors

The activation of adenosine A1 receptors is important for protecting against ischemic brain injury and pretreatment with electroacupuncture has been shown to mitigate ischemic brain insult. The aim of this study was to test whether the adenosine A1 receptor mediates electroacupuncture pretreatment-induced neuroprotection against ischemic brain injury. We first performed 30 minutes of electroacupuncture pretreatment at the Baihui acupoint（GV20）, delivered with a current of 1 mA, a frequency of 2/15 Hz, and a depth of 1 mm. High-performance liquid chromatography found that adenosine triphosphate and adenosine levels peaked in the cerebral cortex at 15 minutes and 120 minutes after electroacupuncture pretreatment, respectively. We further examined the effect of 15 or 120 minutes electroacupuncture treatment on ischemic brain injury in a rat middle cerebral artery-occlusion model. We found that at 24 hours reperfusion,120 minutes after electroacupuncture pretreatment, but not for 15 minutes, significantly reduced behavioral deficits and infarct volumes. Last, we demonstrated that the protective effect gained by 120 minutes after electroacupuncture treatment before ischemic injury was abolished by pretreatment with the A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine（1 mg/kg, intraperitoneally）. Our results suggest that pretreatment with electroacupuncture at the Baihui acupoint elicits protection against transient cerebral ischemia via action at adenosine A1 receptors.

Electroacupuncture improves neuropathic pain Adenosine, adenosine 5'-triphosphate disodium and their receptors perhaps change simultaneously

Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.

Silencing miRNA-324-3p protects against cerebral ischemic injury via regulation of the GATA2/A1R axis

Previous studies have suggested that miR-324-3p is related to the pathophysiology of cerebral ischemia,but the mechanism underlying this relationship is unclea r.In this study,we found that miR-324-3p expression was decreased in patients with acute ischemic stroke and in in vitro and in vivo models of ischemic stro ke.miR-324-3p agomir potentiated ischemic brain damage in rats subjected to middle cerebral artery occlusion,as indicated by increased infarct volumes and cell apoptosis rates and greater neurological deficits.In a PC12 cell oxygen-glucose deprivation/reoxygenation model,a miR-324-3 p mimic decreased cell viability and expression of the anti-apoptotic protein BCL2 and increased expression of the pro-apoptotic protein BAX and rates of cell apoptosis,whereas treatment with a miR-324-3p inhibitor had the opposite effects.Silencing miR-324-3p increased adenosine A1 receptor(A1R)expression thro ugh regulation of GATA binding protein 2(GATA2).These findings suggest that silencing miR-324-3p reduces ischemic brain damage via the GATA2/A1R axis.

Transient receptor potential channel A1 involved in calcitonin gene-related peptide release in neurons

Transient receptor potential channel A1 is one of the important transducers of noxious stimuli in the primary afferents, which may contribute to generation of neurogenic inflammation and hyperalgesia. The present study was designed to investigate if activation of transient receptor potential channel A1 may induce calcitonin gene-related peptide release from the primary afferent neurons. We found that application of allyl isothiocyanate, a transient receptor potential channel A1 activator, caused calcitonin gene-related peptide release from the cultured rat dorsal root ganglion neurons. Knock- down of transient receptor potential channel A1 with an antisense oligodeoxynucleotide prevented calcitonin gene-related peptide release by allyl isothiocyanate application in cultured dorsal root ganglion neurons. Thus, we concluded that transient receptor potential channel A1 activation caused calcitonin gene-related peptide release in sensory neurons.

Transcription factors specificity protein and nuclear receptor 4A1 in pancreatic cancer

Specificity protein(Sp)transcription factors(TFs)Sp1,Sp3 and Sp4,and the orphan nuclear receptor 4A1(NR4A1)are highly expressed in pancreatic tumors and Sp1 is a negative prognostic factor for pancreatic cancer patient survival.Results of knockdown and overexpression of Sp1,Sp3 and Sp4 in pancreatic and other cancer lines show that these TFs are individually pro-oncogenic factors and loss of one Sp TF is not compensated by other members.NR4A1 is also a prooncogenic factor and both NR4A1 and Sp TFs exhibit similar functions in pancreatic cancer cells and regulate cell growth,survival,migration and invasion.There is also evidence that Sp TFs and NR4A1 regulate some of the same genes including survivin,epidermal growth factor receptor,PAX3-FOXO1,α5-andα6-integrins,β1-,β3-andβ4-integrins;this is due to NR4A1 acting as a cofactor and mediating NR4A1/Sp1/4-regulated gene expression through GC-rich gene promoter sites.Several studies show that drugs targeting Sp downregulation or NR4A1 antagonists are highly effective inhibitors of Sp/NR4A1-regulated pathways and genes in pancreatic and other cancer cells,and the triterpenoid celastrol is a novel dual-acting agent that targets both Sp TFs and NR4A1.

In vivo neuronal and astrocytic activation in somatosensory cortex by acupuncture stimuli

Acupuncture is a medical treatment that has been widely pra cticed in China for over 3000 years,yet the neural mechanisms of acupuncture are not fully understood.We hypothesized that neurons and astrocytes act independently and synergistically under acupuncture stimulation.To investigate this,we used two-photon in vivo calcium reco rding to observe the effects of acupuncture stimulation at ST36(Zusanli)in mice.Acupuncture stimulation in peripheral acupoints potentiated calcium signals of pyramidal neurons and astrocytes in the somatosensory cortex and resulted in late-onset calcium transients in astrocytes.Chemogenetic inhibition of neurons augmented the astrocytic activity.These findings suggest that acupuncture activates neuronal and astrocytic activity in the somatosensory co rtex and provide evidence for the involvement of both neurons and astrocytes in acupuncture treatment.

Connexin 36 Mediates Orofacial Pain Hypersensitivity Through GluK2 and TRPA1

Trigeminal neuralgia is a debilitating condition,and the pain easily spreads to other parts of the face.Here,we established a mouse model of partial transection of the infraorbital nerve(pT-ION)and found that the Connexin 36(Cx36)inhibitor mefloquine caused greater alleviation of pT-ION-induced cold allodynia compared to the reduction of mechanical allodynia.Mefloquine reversed the pT-IONinduced upregulation of Cx36,glutamate receptor ionotropic kainate 2(GluK2),transient receptor potential ankyrin 1(TRPA1),and phosphorylated extracellular signal regulated kinase(p-ERK)in the trigeminal ganglion.Cold allodynia but not mechanic al allodynia induced by pT-ION or by virusmediated overexpression of Cx36 in the trigeminal ganglion was reversed by the GluK2 antagonist NS 102,and knocking down Cx36 expression in Nav1.8-expressing nociceptors by injecting virus into the orofacial skin area of Nav1.8-Cre mice attenuated cold allodynia but not mechanic al allodynia.In conclusion,we show that Cx36 contributes greatly to the development of orofacial pain hypersensitivity through GluK2,TRPA1,and p-ERK signaling.

Adenosine A1 receptor ligands bind toα-synuclein:implications forα-synuclein misfolding andα-synucleinopathy in Parkinson’s disease

Background:Accumulatingα-synuclein(α-syn)aggregates in neurons and glial cells are the staples of many synucleinopathy disorders,such as Parkinson’s disease(PD).Since brain adenosine becomes greatly elevated in ageing brains and chronic adenosine A1 receptor(A1R)stimulation leads to neurodegeneration,we determined whether adenosine or A1R receptor ligands mimic the action of known compounds that promoteα-syn aggregation(e.g.,the amphetamine analogue 2-aminoindan)or inhibitα-syn aggregation(e.g.,Rasagiline metabolite 1-aminoindan).In the present study,we determined whether adenosine,A1R receptor agonist N^(6)-Cyclopentyladenosine(CPA)and antago-nist 8-cyclopentyl-1,3-dipropylxanthine(DPCPX)could directly interact withα-syn to modulateα-syn aggregation and neurodegeneration of dopaminergic neurons in the substantia nigra(SN).Methods:Nanopore analysis and molecular docking were used to test the binding properties of CPA and DPCPX withα-syn in vitro.Sprague-Dawley rats were administered with 7-day intraperitoneal injections of the A1R ligands and 1-and 2-aminoindan,and levels ofα-syn aggregation and neurodegeneration were examined in the SN pars compacta and hippocampal regions using confocal imaging and Western blotting.Results:Using nanopore analysis,we showed that the A1R agonists(CPA and adenosine)interacted with the N-terminus ofα-syn,similar to 2-aminoindan,which is expected to promote a“knot”conformation andα-syn misfolding.In contrast,the A1R antagonist DPCPX interacted with the N-and C-termini ofα-syn,similar to 1-aminoindan,which is expected to promote a“loop”conformation that preventsα-syn misfolding.Molecular docking studies revealed that adenosine,CPA and 2-aminoindan interacted with the hydrophobic core ofα-syn N-terminus,whereas DPCPX and 1-aminoindan showed direct binding to the N-and C-terminal hydrophobic pockets.Confocal imaging and Western blot analyses revealed that chronic treatments with CPA alone or in combination with 2-aminoindan increasedα-syn expression/aggregation and neurodegeneration in both SN pars compacta and hippocampus.In contrast,DPCPX and 1-aminoindan attenuated the CPA-inducedα-syn expression/aggregation and neurodegeneration in SN and hippocampus.Conclusions:The results indicate that A1R agonists and drugs promoting a“knot”conformation ofα-syn can causeα-synucleinopathy and increase neuronal degeneration,whereas A1R antagonists and drugs promoting a“loop”con-formation ofα-syn can be harnessed for possible neuroprotective therapies to decreaseα-synucleinopathy in PD.

Effcacy-oriented compatibility for Tianma(Rhizoma Gastrodiae),Yanlingcao(Trillium tschonoskii Maxim) and Bingpian(Borneolum Syntheticum) on improving cerebral ischemia stroke by network pharmacology and serum pharmacological methods

OBJECTIVE:To evaluate the compatibility of Tianma(Rhizoma Gastrodiae,TM),Yanlingcao(Trillium tschonoskii Maxim,YLC)and Bingpian(Borneolum Syntheticum,BP),and their efficacy in the treatment of cerebral ischemic stroke.METHODS:Network pharmacology was used to determine the compatibility of TM,YLC,and BP,and their potential mechanism.The middle cerebral artery occlusion(MCAO)rat model was used to evaluate the curative effect of the six combinations of TM,YLC,and BP(TZB1-TZB6)on cerebral ischemia,by using the weight matching method to form.The potential component changes of TM and YLC in the blood and brains of rats were analyzed using ultra performance liquid chromatography-mass spectrometry.Finally,molecular docking linked the results of animal experiments and network pharmacology,determining the potential component contributors of TM and YLC to treating ischemic stroke.RESULTS:TZB reduced the cerebral infarct volume and protected the nerve cells in MCAO rats.The components of TM and YLC were also identified in the blood and brain homogenate,and BP can facilitate the entry of the components of TM and YLC into the blood and brain.Diosgenin,pennogenin,and gastrodin induced effective binding activities with adenosine receptor a1.CONCLUSION:We investigate an approach that improves the means of folk prescription combined with multi technology that maybe promote the transformation of Chinese medicinal prescription into component-based Chinese medicine.