P2Y1 receptor in Alzheimer’s disease

Alzheimer’s disease is the most frequent form of dementia characterized by the deposition of amyloid-beta plaques and neurofibrillary tangles consisting of hyperphosphorylated tau.Targeting amyloid-beta plaques has been a primary direction for developing Alzheimer’s disease treatments in the last decades.However,existing drugs targeting amyloid-beta plaques have not fully yielded the expected results in the clinic,necessitating the exploration of alternative therapeutic strategies.Increasing evidence unravels that astrocyte morphology and function alter in the brain of Alzheimer’s disease patients,with dysregulated astrocytic purinergic receptors,particularly the P2Y1 receptor,all of which constitute the pathophysiology of Alzheimer’s disease.These receptors are not only crucial for maintaining normal astrocyte function but are also highly implicated in neuroinflammation in Alzheimer’s disease.This review delves into recent insights into the association between P2Y1 receptor and Alzheimer’s disease to underscore the potential neuroprotective role of P2Y1 receptor in Alzheimer’s disease by mitigating neuroinflammation,thus offering promising avenues for developing drugs for Alzheimer’s disease and potentially contributing to the development of more effective treatments.

Effects of P2Y_1 receptor on glial fibrillary acidic protein and glial cell line-derived neurotrophic factor production of astrocytes under ischemic condition and the related signaling pathways

Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Role of P2X_7 receptors in the development of diabetic retinopathy

The P2X7 receptor is one of the members of the family of purinoceptors which are ligand-gated membrane ion channels activated by extracellular adenosine 5'-triphosphate. A unique feature of the P2X7 receptor is that its activation can result in the formation of large plasma membrane pores that allow not only the flux of ions but also of hydrophilic molecules of up to 900 Da. Recent studies indicate that P2X7-mediated signaling can trigger apoptotic cell death after ischemia and during the course of certain neurodegenerative disorders. Expression of the P2X7 receptor has been demonstrated in most types of cells in the retina. This purinoceptor mediates the contraction of pericytes and regulates the spatial and temporal dynamics of the vasomotor response through cell-to-cell electrotonic transmission within the microvascular networks. Of potential clinical significance, investigators have found that diabetes markedly boosts the vulnerability of retinal microvessels to the lethal effect of P2X7 receptor activation. This purinergic vasotoxicity may result in reduced retinal blood flow and disrupted vascular function in the diabetic retina. With recent reports indicating an association between P2X7 receptor activation and inflammatory cytokine expression in the retina, this receptor may also exacerbate the development of diabetic retinopathy by a mechanism involving inflammation.

Prognostic Value of Promoter Hypermethylation of Retinoic Acid Receptor Beta (RARB) and CDKN2 (p16/MTS1) in Prostate Cancer

Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB) and p16 among benign prostatic hyperplasia (BPH) and prostate cancer patients. Methods: In this case-control study, 63 patients were included in three groups; 21 with BPH as the control group, 21 with prostate cancer and good prognostic factors (based on prostate-specific antigen, Gleason score and stage) as good prognosis group, and 21 with prostate cancer and poor prognostic features as poor prognosis group. The prostate biopsy specimen of each individual was examined for hypermethylation of RARB and p16 promoters by methylation specific PCR (MSPCR). Results: Seven (33.3%) patients with good prognosis and 15 (71.4%) patients with poor prognosis were positive for RARB methylation, which were significantly higher than controls (P <0.0001). p16 promoter methylation was shown in 19.0% and 47.6% patients with good and poor prognosis, respectively. The RARB and p16 promoter methylation in the poor prognosis group was significantly higher than that in the good prognosis group (P =0.02 for RARB and P<0.0001 for p16). Conclusion: Hypermethylation of RARB and p16 promoters may predict prognosis in prostate cancer.

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.

合募配穴针刺对肠易激综合征模型大鼠脊髓背根神经节PAR-2、TRVP1及相关致敏细胞因子表达的影响

目的观察合募配穴针刺对肠易激综合征(IBS)大鼠脊髓背根神经节(DRG)蛋白酶活化受体-2(PAR-2)、P物质(SP)、瞬时受体电位香草酸亚型1(TRPV1)和降钙素相关肽(CGRP)表达的影响,探讨合募配穴针刺对内脏高敏感性的可能作用机制。方法采用雄性SD大鼠慢性应激结合束缚法制备肠易激综合征模型。随机分为空白组、模型组、合募针刺组和药物组。造模成功后,合募针刺组对大肠下合穴上巨虚和募穴天枢穴进行电针干预;药物组给予匹维溴胺灌胃。采用腹部回撤反射(AWR)对大鼠进行内脏敏感性评估并观察大鼠体质量变化情况,用免疫组织化学方法检验脊髓L5-S1段PAR-2、TRVP1、SP和CGRP的表达。结果 AWR评分中,治疗前合募针刺组和模型组与空白组比较差异明显(P<0.01),治疗后合募针刺组与模型组比较有显著性差异(P<0.01),针刺治疗IBS内脏高敏感性有效;治疗后模型组大鼠与空白组比较,脊髓背根神经节中PAR-2、SP、TRVP1和CGRP的IOD值显著升高(P<0.01);合募针刺组和药物组与模型组比较,脊髓背根神经节中PAR-2、SP、TRVP1和CGRP的IOD值明显降低(P<0.01)。结论合募配穴针刺干预机制可能是通过PAR-2、TRVP1降低SP和CGRP在DRG神经元中的表达来降低IBS大鼠的内脏高敏感性。

健脾解毒方对脾虚肝癌大鼠生存的影响及与TCR、ERK1/2信号通路的关系

目的探讨健脾解毒方对脾虚肝癌大鼠生存的影响及与TCR、ERK1/2、p-ERK1/2的关系。方法 105只Wistar大鼠脾虚肝癌模型组,进行造模和干预。随机分为空白对照组(A组),肝癌模型组(B组),脾虚对照组(C组),脾虚肝癌模型组(D组),健脾解毒方低浓度E组、高浓度F组及胸腺五肽组(G组)。实验中记录动物的体质量、生存时间、肝癌大鼠濒死状态时恶液质积分并采集标本。Western blot方法检测大鼠肝组织、肝癌组织、T淋巴细胞中TCR蛋白表达,以及T淋巴细胞中ERK1/2、p-ERK1/2蛋白的表达。结果健脾解毒方高浓度组和胸腺五肽组大鼠终末期体质量、累积生存率高于脾虚肝癌模型组及肝癌模型组(P <0. 05),终末期恶液质积分则更低(P <0. 05)。健脾解毒方高浓度组大鼠肝组织、癌组织中TCR蛋白表达量,外周T淋巴细胞中TCR蛋白、ERK1/2蛋白、p-ERK1/2蛋白表达量均较脾虚肝癌模型组明显增加(P <0. 05)。结论高浓度健脾解毒方能延缓荷瘤鼠恶液质的发生和进展,明显延长荷瘤鼠生存时间,其作用可能与健脾解毒方上调TCR、ERK1/2及p-ERK1/2有关。

P2Y1R is involved in visceral hypersensitivity in rats with experimental irritable bowel syndrome

AIM To evaluate the role of P2Y1 R in visceral hypersensitivity in rats with experimental irritable bowel syndrome.METHODS A rat model of irritable bowel syndrome was generated by intra-colonic administration of acetic acid(AA) and assessed by histology and myeloperoxidase(m PO) activity assay. Then P2Y1 R expression in the colonic tissue was detected by Western blot. In order to explore the regulatory role of P2Y1 R in visceral hypersensitivity, an agonist(m RS2365) and an antagonist(m RS2179) of P2Y1 R were intra-colonically administered and effects were tested through a colorectal distension test. The abdominal withdrawal reflex and abdominal electromyography were tested during the course. RESULTS model assessment tests showed an obvious inflammatoryreaction that appeared on the 2^(nd) d after the AA injection, and the inflammatory reaction gradually recovered and almost disappeared on the 7^(th) d. The model finished on day 8 and showed a clear feature of IBS that had no organic lesion. The average expression of P2Y1 R was significantly higher in the AA group than in the na?ve group(0.319 ± 0.02 vs 0.094 ± 0.016, P < 0.001). m RS2365 could effectively raise the colonic hypersensitivity status at intervention doses of 10(AUC value from 0.30 ± 0.089 to 1.973 ± 0.127 mv?s, P < 0.01) and 100 μmol/L(AUC value from 0.290 ± 0.079 to 1.983 ± 0.195 mv?s, P < 0.01); m RS2179 could effectively reduce the hypersensitivity status at intervention dose of 100 μmol/L(from a mean baseline AUC value of 1.587 ± 0.099 mv?s to 0.140 ± 0.089 mv?s, P < 0.0001). Differences between the m RS2179 group(1.88 ± 1.45) and either the m RS2365 group(3.96 ± 0.19) or the combined treatment(m RS2179 and m RS2365) group(3.28 ± 0.11) were significant(P < 0.01).CONCLUSION P2Y1 R plays a regulatory role in visceral hypersensitivity in rats with experimental IBS. Specific antagonists of P2Y1 R may have potential therapeutic value in treating abdominal pain in IBS.

基于瞬时受体电位香草酸1通道探讨电针治疗骶上脊髓损伤后神经源性膀胱大鼠的作用机制

目的探讨电针“中极”“关元”穴对骶上脊髓损伤后逼尿肌反射亢进型大鼠的治疗效果及作用机制。方法脊髓横断法建立骶上脊髓损伤后神经源性膀胱模型,电针组以“中极”“关元”穴进行电针干预(10 Hz/50 Hz,强度1 mA),抑制剂组给予capsazepine(2.5 mL,100 nmol/L,30 min)灌注。结束后行尿流动力学检测,HE染色观察膀胱组织形态学变化,免疫荧光双标法观察膀胱ICC细胞C⁃Kit、P2X_(2)受体阳性表达水平,Western blot检测大鼠膀胱组织中TRPV1、C⁃Kit、P2X_(2)蛋白表达水平。结果与假手术组比较,模型组大鼠膀胱基础压和漏尿点压升高,膀胱最大容量和顺应性下降(P<0.01),膀胱组织中TRPV1、C⁃Kit、P2X2蛋白表达升高(P<0.01);与模型组比较,电针组、抑制剂组大鼠膀胱基础压和漏尿点压下降,膀胱最大容量和顺应性升高(P<0.01),膀胱组织中TRPV1、C⁃Kit、P2X2蛋白表达明显降低(P<0.01)。结论电针“中极”“关元”穴可通过抑制TRPV1通道减少膀胱ICC细胞上的P2X_(2)受体表达,减少平滑肌收缩频率,改善膀胱功能。

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.

Axonal growth inhibitors and their receptors in spinal cord injury:from biology to clinical translation

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

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.

Involvement of Ca^(2+)-activated K^+ Channels in Receptor-Regulated Sperm Motility in Rats

Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.

P2X7 receptor activation causes phosphatidylserine exposure in canine erythrocytes

AIM To determine if activation of the ATP-gated P2X7 receptor channel induces phosphatidylserine(PS) exposure in erythrocytes from multiple dog breeds.METHODS Peripheral blood was collected from 25 dogs representing 13 pedigrees and seven crossbreeds. ATP-induced PS exposure on canine erythrocytes in vitro was assessed using a flow cytometric Annexin V binding assay.RESULTS ATP induced PS exposure in erythrocytes from all dogs studied. ATP caused PS exposure in a concentrationdependent manner with an EC50 value of 395 μmol/L. The non-P2X7 agonists, ADP or AMP, did not cause PS exposure. The P2X7 antagonist, AZ10606120, but not the P2X1 antagonist, NF449, blocked ATP-induced PS exposure.CONCLUSION The results indicate that ATP induces PS exposure in erythrocytes from various dog breeds and that this process is mediated by P2X7 activation.

P2X_(1) receptor-mediated pressor responses in the anesthetized mouse

P2X_(1) receptors and adrenoceptors are mainly responsible for vasoconstriction in a variety of blood vessels.However,previous studies have shown that α,β-methylene adenosine 5'-triphosphate(α,β-MeATP),a stable analogue of ATP,can induce both pressor and depressor responses in la boratory animals.In this study,the effects of increasing intravenous doses of α,β-MeATP and noradrenaline(NA)(0-30 nmol/kg)administered at 20 min intervals on systolic(SBP),diastolic(DBP)and mean(MBP)blood pressure in groups of anesthetized mice(n=6)were compared.Both α,β-MeATP and NA caused transient,dose-dependent increases in SBP,DBP and MBP but the effect of α,β-MeATP was more rapid and significantly larger at doses of 10 and 30 nmol/kg(P<0.01).At the dose of 30 nmol/kg,α,β-MeATP increased SBP,DBP and MBP by 65.8±7.0,65.7±5.0 and 65.7±5.5 mmHg,respectively,compared to increases of 36.8±4.6,33.3±4.9 and 34.5±4.7 mmHg,respectively,produced by NA.These results indicate P2X_(1) receptors play an important role in BP regulation although purinergic vasoconstriction alone may not explain the more potent pressor response to α,β-MeATP in the anesthetized mouse.

急性坏死性胰腺炎肠粘膜损害与NK-IR的过度表达相关

目的 :研究神经激肽 - 1受体 (NK - 1R)和神经激肽 - 2受体 (NK - 2R)在急性坏死性胰腺炎 (ANP)大鼠末端回肠组织中的表达 ,探讨该受体的表达与ANP肠粘膜损害的关系。方法 :健康成年Sprague -Dawley大鼠随机分为假手术对照组 (5 0只 )和ANP组 (80只 )。假手术对照组开腹后只翻动胰腺 ,ANP组大鼠胰胆管恒速逆行注射 5 %牛磺胆酸钠 ,制成ANP大鼠模型。应用逆转录聚合酶链反应 (RT -PCR)检测末端回肠组织NK - 1R和NK - 2R的mRNA水平 ,应用Westernblot检测NK - 1R的蛋白表达水平。结果 :与假手术对照组相比 ,ANP末端回肠组织中NK - 1R和NK - 2R的mRNA水平过度表达。NK - 1R的表达水平分别与肠粘膜的病理学评分 (r =0 77,P <0 0 1)和肠粘膜通透性 (r=0 6 8,P <0 0 1)呈明显正相关。结论 :ANP时 ,肠组织中NK - 1R和NK - 2R的表达水平明显上调 ,P物质的过度作用加剧ANP时肠粘膜的病理损害 ,损害肠粘膜屏障的功能。

半胱氨酰白三烯受体拮抗剂pranlukast对小鼠局灶性脑缺血的治疗作用

目的观察半胱氨酰白三烯受体拮抗剂pranlukast(ONO 1078)在小鼠局灶性脑缺血后的治疗作用。方法采用大脑中动脉阻塞造成小鼠持续性局灶性脑缺血,缺血后1、6、24h分别给小鼠腹腔注射pranlukast或依达拉奉,观察药物对缺血24、48h后的神经功能缺损症状,48h后的脑梗死体积、两侧大脑半球比值、神经元密度的影响。结果Pranlukast 01、02mg·kg-1及依达拉奉3、10mg·kg-1均能减轻神经症状、减小脑梗死体积、降低缺血侧/非缺血侧大脑半球比值、减轻海马CA1区、皮层和纹状体的神经元密度降低。结论Pranlukast脑缺血后给药对脑损伤有治疗作用,提示有治疗缺血性脑卒中的临床前景。

Ang II type 1 receptor expression in rat aorta exposed to chronic intermittent hypoxia： effects of p38MAPK and ERK1/2 signaling

Background Obstructive sleep apnea is a frequent medical condition consisting of repetitive sleep-related episodes of upper air ways obstruction and can lead to hypertension. Ang II type 1 receptor （AT1R） played important roles in hypertension since it binds with Ang II, controlling salt-water and blood pressure homeostasis. This study explores rat aorta AT1R expression during intermittent hypoxia （IH） and the signaling pathways involved. Methods A rat model and a cell model used a BioSpherix-OxyCycler A84 system and a ProOx C21 system respectively. The arterial blood pressure was recorded by a Nihon Kohden Polygraph System. Immunohistochemic was used to focus and analyze the expression of AT1R in rat aorta. Real-time PCR and Western blotting were used to explore the signaling pathways that participated in AT1R expression. Results In this study, we found that chronic intermittent hypoxia （CIH） induced AT1R transcription which increased the blood pressure in rat aorta compared to normoxia and to sustained hypoxia. The AT1R protein expression in the aorta was similar to the real-time PCR results. We explored the signaling mechanisms involved in the AT1R induction in both rat aorta and the aortic endothelial cells by real-time PCR and Western blotting. Compared to normoxia, CIH increased ERK1 mRNA transcription but not ERK2 or p38MAPK in the aorta; whereas sustained hypoxia （SH） upregulated ERK2 but not ERK1 or p38MAPK mRNA. In cells, IH induced AT1R expression with ERK1/2 phosphorylation but reduced p38MAPKs phosphorylation, whereas SH induced only ERK1/2 phosphorylation. The ERK1/2 inhibitor PD98059 attenuated the IH- induced AT1R increase but the p38MAPK inhibitor SB203580 did not. Conclusions Our results indicate that CIH induced the elevation of rat blood pressure and aorta AT1R expression. Moreover, ATIR expression in IH and sustained hypoxia might be regulated by different signal transduction pathways, highlighting a novel regulatory function through ERK1/2 signaling in IH.

Inhibition of inflammatory mediator release from microglia can treat ischemic/hypoxic brain injury

Interleukin-1α and interleukin-1β aggravate neuronal injury by mediating the inf1αmmatory reaction following ischemic/hypoxic brain injury. It remains unclear whether interleukin-1α and interleukin-1β are released by microglia or astrocytes. This study prepared hippocampal slices that were subsequently subjected to oxygen and glucose deprivation. Hematoxylin-eosin staining verified that neurons exhibited hypoxic changes. Results of enzyme-linked immunosorbent assay found that interleukin-1α and interleukin-1β participated in this hypoxic process. Moreover, when hypoxic injury occurred in the hippocampus, the release of interleukin-1α and interleukin-1β was mediated by the P2X4 receptor and P2X7 receptor. Immunofluorescence staining revealed that during ischemia/hypoxia, the P2X4 receptor, P2X7 receptor, interleukin-1α and interleukin-1β expression was detectable in rat hippocampal microglia, but only P2X4 receptor and P2X7 receptor expression was detected in astrocytes. Results suggested that the P2X4 receptor and P2X7 receptor, respectively, mediated interleukin-1α and interleukin-1β released by microglia, resulting in hippocampal ischemic/hypoxic injury. Astrocytes were activated, but did not synthesize or release interleukin-1α and interleukin-1β.

CaMKIIα and caveolin-1 cooperate to drive ATP-induced membrane delivery of the P2X3 receptor

The P2X3 receptor plays a vital role in sensory processing and transmission. The assembly and trafficking of the P2X3 receptor are important for its function in primary sensory neurons. As an important inflammation mediator, ATP is released from different cell types around primary sensory neurons, especially under pathological pain conditions. Here, we showthat α, β-MeATP dramatically promoted membrane delivery of the P2X3 receptor both in HEK293T celts expressing recombinant P2X3 receptor and in rat primary sensory neurons. α, β-MeATP induced P2X3 receptor-mediated Ca^2＋ influx, which further activated Ca^2＋/calmodulin-dependent protein kinase Ilec （CaMKIIα）. The N terminus of the P2X3 receptor was responsible for CaMKIleα binding, whereas Thr38s in the C terminus was phosphorylated by CaMKIIα. Thr^388 phosphorylation increased P2X3 receptor binding to caveoUn-1. CaveoUn-1 knockdown abrogated the α, β-MeATP-induced membrane insertion of the P2X3 receptor. Moreover,α, β-MeATP drove the CaMKIlec-mediated membrane coinsertion of the P2X2 receptor with the P2X3 receptor. The increased P2X3 receptors on the cell membrane that are due to Thr388 phosphorytation facilitated P2X3 receptor-mediated signal transduction. Together, our data indicate that CaMKIIoL and caveoUn-1 cooperate to drive Ugand-induced membrane delivery of the P2X3 receptor and may provide a mechanism of P2X3 receptor sensitization in pain development.