Adenosine triphosphate induced cell death: Mechanisms and implications in cancer biology and therapy

Adenosine triphosphate(ATP)induced cell death(AICD)is a critical cellular process that has garnered substantial scientific interest for its profound relevance to cancer biology and to therapeutic interventions.This comprehensive review unveils the intricate web of AICD mechanisms and their intricate connections with cancer biology.This review offers a comprehensive framework for comprehending the multifaceted role of AICD in the context of cancer.This is achieved by elucidating the dynamic interplay between systemic and cellular ATP homeostasis,deciphering the intricate mechanisms governing AICD,elucidating its intricate involvement in cancer signaling pathways,and scrutinizing validated key genes.Moreover,the exploration of AICD as a potential avenue for cancer treatment underscores its essential role in shaping the future landscape of cancer therapeutics.

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.

Suppressing high mobility group box-1 release alleviates morphine tolerance via the adenosine5'-monophosphate-activated protein kinase/heme oxygenase-1 pathway

Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.

Autophagy occurs within an hour of adenosine triphosphate treatment after nerve cell damage:the neuroprotective effects of adenosine triphosphate against apoptosis

After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cell death that also has neuroprotective effects. Cell Counting Kit assay, monodansylcadaverine staining, flow cytometry, western blotting, and real-time PCR were used to determine the effects of exogenous adenosine triphosphate treatment at different concentrations （2, 4, 6, 8, 10 mmol/L） over time （1, 2, 3, and 6 hours） on the apoptosis and autophagy of SH-SY5Y cells. High concentrations of extracellular adenosine triphosphate induced autophagy and apoptosis of SH-SYSY cells. The enhanced autophagy first appeared, and peaked at 1 hour after treatment with adenosine triphosphate. Cell apoptosis peaked at 3 hours, and persisted through 6 hours. With prolonged exposure to the adenosine triphosphate treatment, the fraction of apoptotic cells increased. These data suggest that the SH-SY5Y neural cells initiated autophagy against apoptosis within an hour of adenosine triphosphate treatment to protect themselves against injury.

Adenosine triphosphate promotes locomotor recovery after spinal cord injury by activating mammalian target of rapamycin pathway in rats

The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.

Efficient production of cyclic adenosine monophosphate from adenosine triphosphate by the N-terminal half of adenylate cyclase from Escherichia coli

In this study,we aimed at developing an efficient biocatalytic process for bio-production of cyclic adenosine monophosphate(c AMP)from adenosine triphosphate(ATP).First,adenylate cyclase from Escherichia coli MG1655(EAC)and Bordetella Pertussis(BAC)were expressed in E.coli BL21(DE3)and comparatively analyzed for their activities.As a result,EAC from E.coli MG1655 exhibited a higher activity.However,amount of EAC were obtained in an insoluble form.Therefore,we expressed the first 446 amino acids of EAC(EAC446)to avoid the inclusion body.The effects of induction temperature,incubation time,and incubation p H were further evaluated to improve the expression of EAC446.Subsequently,the reaction process for the production of c AMP with ATP as a starting material was investigated.As none of c AMP was detected in the whole-cell based biocatalytic process,the reaction catalyzed by the crude enzyme was determined for c AMP production.What's more,the reaction temperature,reaction p H,metal ion additives and substrate concentration was optimized,and the maximum c AMP production of 18.45 g·L^-1was achieved with a yield of 95.4%after bioconversion of 6 h.

Inhibitory effects of extracellular adenosine triphosphate on growth of esophageal carcinoma cells

AIM: To study the growth inhibitory effects of ATP on TE-13 human squamous esophageal carcinoma cells in vitro.METHODS: MTT assay was used to determine the inhibition of proliferation of ATP or adenosine (ADO) on TE-13 cell line. The morphological changes of TE-13 cells induced by ATP or ADO were observed under fluorescence light microscope by acridine orange (AO)/ethidium bromide (EB) double stained cells. The intemudeosomal fragmentation of genomic DNA was detected by agarose gel electrophoresis.The apoptotic rate and cell cycle after treatment with ATP or ADO were determined by flow cytometry.RESULTS: ATP and ADO produced inhibitory effects on TE-13 cells at the concentration between 0.01 and 1.0 mmol/L.The IC50 of TE-13 cells exposed to ATP or ADO for 48 and 72 h was 0.71 or 1.05, and 0.21 or 0.19 mmol/L, respectively.The distribution of cell cycle phase and proliferation index (PI) value of TE-13 cells changed, when being exposed to ATP or ADO at the concentrations of 0.01, 0.1, and 1 mmol/L for 48 h. ATP and ADO inhibited the cell proliferation by changing the distribution of cell cycle phase via either G0/G1 phase (ATP or ADO, 1 mmol/L) or S phase (ATP, 0.1 mmol/L)arrest. Under light microscope, the tumor cells exposed to 0.3 mmol/L ATP or ADO displayed morphological changes of apoptosis. A ladder-like pattern of DNA fragmentation was obtained from TE-13 cells treated with 0.1-1 mmol/L ATP or ADO in agarose gel electrophoresis. ATP and ADO induced apoptosis of TE-13 cells in a dose-dependent manner at the concentration between 0.03 and 1 mmol/L.The maximum apoptotic rate of TE-13 cells exposed to ATP or ADO for 48 h was 16.63% or 16.9%, respectively.CONCLUSION: ATP and ADO inhibit cell proliferation,arrest cell cycle, and induce apoptosis of TE-13 cell line.

Protective effect of exogenous adenosine triphosphate on hypothermically preserved rat liver

AIM:To clarify the protective effect of exogenous adenosine triphosphate (ATP)on hypothermically preserved rat livers.METHODS: Establishment of continuous hypothermic machine perfusion model,detection of nucleotides in hepatocytes with HPLC, measurement of activities of LDH and AST in the perfusate, observation of histopathological changes in different experiment groups, and autoradiography were carried out to reveal the underlying mechanism of the protective effect of ATRRESULTS:The intracellular levels of ATP and EC decreased rapidly after hypothermic preservation in control group,while a higher ATP and EC level, and a slower decreasing rate were observed when ATP-MgCl2 was added to the perfusate (P<0.01). As compared with the control group, the activities of LDH and AST in the ATP-MgCl2 group were lower (P<0.05).Furthermore, more severe hepatocyte damage and neutrophil infiltration were observed in the control group. Radioactive [α-^32P] ATP entered the hypothermically preserved rat hepatocytes.CONCLUSION: Exogenous ATP has a protective effect on rat livers during hypothermical preservation. However, Mg^2+ is indispensable, addition of ATP alone produces no protective effect.The underlying mechanism may be that exogenous ATP enters the hypothermically preserved rat liver cells.

Nicotinamide Adenine Dinucleotide and Adenosine Triphosphate Oscillations Caused by Gradual Entry of Substrates within Mitochondria

Nicotinamide adenine dinucleotide (NAD) oscillation was observed when the isolated mitochondria were immersed in a pyruvate solution. In addition, when an adenosine diphosphate (ADP) was added to the mitochondrial suspension containing pyruvate, adenosine triphosphate (ATP) oscillation was observed as well as NADH oscillation. At this time, the pH within mitochondria also oscillated. It was found that the oscillatory reaction of NADH caused by the membrane permeation of pyruvate continues, causing the oscillation of NADH and H+ in the subsequent reactions. The pH oscillation led to the ATP oscillation. It is considered that the oscillatory reaction caused by the gradual entry of pyruvate into mitochondria was thought to be carried over to both the citric acid cycle and the respiratory chain, ultimately leading to the ATP oscillation in oxidative phosphorylation. Similarly, it was found that membrane permeation of malate causes the gradual occurrence of NADH, at which point NADH oscillates, followed by an oscillatory reaction of the respiratory chain, and finally ATP oscillation. It was found that the oscillations of NADH and ATP occur without going through the citric acid cycle. Oscillations of NADH and other intermediates in both the citric acid cycle and respiratory chain were also confirmed by experiments using semipermeable membranes. These results support our hypothesis that the gradual entry of the substrate by membrane permeation triggers an oscillatory reaction of the enzyme, which is also carried over to subsequent reactions.

亚慢性PM_(2.5)和O_(3)共同暴露对大鼠鼻黏膜ATP总量及ATP酶活性的影响

目的:探讨细颗粒物(fine particle matter,PM_(2.5))和臭氧(ozone,O_(3))亚慢性共同暴露对大鼠鼻黏膜组织腺嘌呤核苷三磷酸(adenosine triphosphate,ATP)总量及ATP酶活性的影响。方法:采用随机数字表法将20只雄性Sprague Dawley(SD)大鼠均分为对照组和暴露组,每组各10只,分别饲养于常规清洁级环境和本团队既往所搭建的大气污染物暴露系统中,连续暴露208 d。暴露期间,监测暴露系统内PM_(2.5)和O_(3)浓度,采用自测和站点数据相结合的方法对暴露系统内PM_(2.5)和O_(3)进行综合评估。在暴露第208天处死大鼠取心、肝、脾、肾、睾丸等主要器官和鼻黏膜组织,称量各脏器重量并计算脏器系数。利用所收集鼻黏膜组织,使用生物发光法测定ATP总量,使用分光光度法检测Na^(+)-K^(+)-ATP酶和Ca^(2+)-ATP酶活性。使用两独立样本t检验比较各指标组间差异。结果:自第3周开始至暴露结束,暴露组大鼠体质量高于对照组(P<0.05),两组间脏器系数差异无统计学意义。暴露组日均PM_(2.5)浓度为(30.68±19.23)μg/m3,O_(3)最大8 h浓度(O_(3)-8 h)为(82.45±35.81)μg/m3。暴露组大鼠鼻黏膜组织ATP化学发光值(792.4±274.1)IU/L低于对照组(1126.8±218.1)IU/L,鼻黏膜组织Na^(+)-K^(+)-ATP酶活性(1.53±0.85)U/mg低于对照组(4.31±1.60)U/mg(P<0.05)。对照组和暴露组鼻黏膜组织的蛋白含量分别为(302.14±52.51)mg/L和(234.58±53.49)mg/L,Ca^(2+)-ATP酶活性分别为(0.81±0.27)U/mg和(0.99±0.73)U/mg,组间差异均无统计学意义。结论:亚慢性PM_(2.5)和O_(3)共同暴露可能影响大鼠鼻黏膜组织供氧能力。

金属有机框架Cu@Sc-MOF纳米酶对5'-三磷酸腺苷的比色/荧光检测

通过溶剂热法制备了一种铜/钪金属有机框架(Cu@Sc-MOF)纳米酶,在H2O2存在下,Cu@Sc-MOF可催化氧化3,3’,5,5’-四甲基联苯胺(TMB)得到蓝色氧化产物oxTMB,并在652 nm处产生特征吸收峰。同样,Cu@Sc-MOF也可氧化邻苯二胺(OPD)生成2-氨基吩嗪(DAP),并在570 nm产生特征荧光发射峰(激发波长为390 nm)。由于5’-三磷酸腺苷(ATP)与Cu2+络合,抑制了Cu@Sc-MOF的催化活性,使得652 nm处的吸光度和570 nm处的荧光强度减弱,基于Cu@Sc-MOF的类过氧化物酶活性,构建了一种用于检测ATP的比色/荧光双模式光谱法。比色和荧光分析法的线性范围分别为2.50~40.00μmol/L和1.00~22.50μmol/L,检出限(LOD)分别为0.60和0.27μmol/L。将上述比色/荧光双模式分析法用于肝癌细胞HepG2细胞裂解液中ATP的检测,加标回收率分别为92.0%~101%和93.2%~97.9%,具有良好的应用前景。

前列腺癌组织中ABCC4、miR-125b-5p表达水平与患者术后预后的关系

目的 探究前列腺癌(PCa)组织中三磷酸腺苷结合盒转运体C4(ABCC4)、微小RNA-125b-5p(miR-125b-5p)表达水平与患者术后3年内生存的关系。方法 选取2017年11月至2020年2月在该院确诊的PCa患者60例,术中收集PCa组织(PCa组)和癌旁组织(对照组)。检测样本中ABCC4 mRNA、miR-125b-5p表达水平及ABCC4的表达情况;对患者术后随访3年。分析PCa组织中ABCC4 mRNA和miR-125b-5p表达水平的相关性,二者与临床病理特征及预后的关系,影响PCa患者预后的因素,二者对患者3年内生存的预测价值。结果 PCa组ABCC4 mRNA表达水平和阳性表达率高于对照组,miR-125b-5p表达水平低于对照组(P<0.05);PCa组织中ABCC4 mRNA与miR-125b-5p表达水平呈负相关(P<0.05);PCa组织ABCC4 mRNA、miR-125b-5p表达水平与肿瘤分期、血清前列腺特异性抗原、Gleason评分、肿瘤转移有关(P<0.05);ABCC4 mRNA高表达组、miR-125b-5p低表达组患者3年累积生存率分别低于ABCC4 mRNA低表达组、miR-125b-5p高表达组(P<0.05);死亡组PCa组织中ABCC4 mRNA表达水平高于生存组,miR-125b-5p表达水平低于生存组(P<0.05);ABCC4 mRNA表达偏高、miR-125b-5p表达偏低是PCa患者预后不良的独立危险因素(P<0.05);相较于ABCC4 mRNA、miR-125b-5p各自单独预测PCa患者3年内生存的曲线下面积(AUC),二者联合检测的AUC更高(P<0.05)。结论 ABCC4在PCa患者癌组织中呈高表达,miR-125b-5p呈低表达,二者联合检测对PCa患者3年内生存有较高预测效能。

Changes in P2Y purinoreceptor-mediated intracellular calcium signal pathways results in inositol-1, 4, 5-triphosphate-sensitive calcium stores in rat small trigeminal ganglion neurons

BACKGROUND： Most of the currently available information on purinergic receptors （P2Rs） involved in pain transmission is based on results obtained in dorsal root ganglion or the spinal cord. However, the mechanism of P2Rs in trigeminal neuralgia remains unclear. OBJECTIVE： To investigate changes in the P2R-mediated calcium signaling pathway in nociceptive trigemJnal ganglion neurons. DESIGN, TIME AND SETTING： In vitro experiments were conducted at the Patch-Clamp Laboratory of Comprehensive Experiment Center of Anhui Medical University, China from September 2008 to June 2009. MATERIALS： Thapsigargin, caffeine, suramin, and adenosine 5＇-triphosphate were purchased from Sigma, USA. METHODS： Using Fura-2-based microfluorimetry, intracellular calcium concentration （[Ca^2＋]i） was measured in freshly isolated adult rat small trigeminal ganglion neurons before and after drug application. MAIN OUTCOME MEASURES： Fluorescent intensities were expressed as the ratio F340/F380 to observe [Ca^2＋]i changes. RESULTS： In normal extracellular solution and Ca^2＋-free solution, application of thapsigargin （1 μmol/L）, a sarcoplasmic reticulum Ca^2＋ pump adenosine 5＇-triphosphate inhibitor, as well as caffeine （20 mmol/L）, a ryanodine receptor agonist, triggered [Ca^2＋]i increase in small trigeminal ganglion neurons. A similar response was induced by application of adenosine 5＇-triphosphate （100 μmol/L）. In Ca^2＋-free conditions, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were inhibited in cells pre-treated with thapsigargin （P 〈 0.01）, but not by caffeine （P 〉 0.05）. In normal, extracellular solution, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were partly inhibited in cells pre-treated with thapsigargin （P 〈 0.05）. CONCLUSION： Inositol-1,4, 5-triphosphate （IP3）- and ryanodine-sensitive Ca^2＋ stores exist in rat nociceptive trigeminal ganglion neurons. Two pathways are involved in the purinoreceptor-mediated [Ca^2＋]i rise observed in nociceptive trigeminal ganglion neurons. One pathway involves the metabotropic P2Y receptors, which are associated with the IP3 sensitive Ca^2＋store, and the second pathway is coupled to ionotropic P2X receptors that induce the Ca^2＋ influx.

高效液相色谱法同时测定烟酰胺单核苷酸中5种有关物质

目的构建同时检测烟酰胺单核苷酸(nicotinamide mononucleotide,NMN)中5种有关物质[烟酰胺氧化物、三磷酸腺苷(adenosine triphosphate,ATP)、二磷酸腺苷(adenosine diphosphate,ADP)、一磷酸腺苷(adenosine monophosphate,AMP)及烟酰胺]含量的高效液相色谱法。方法采用C18色谱柱(250 mm×4.6 mm,5μm),以50 mmol/L磷酸二氢钾缓冲盐溶液(用磷酸调节pH为4.5)-甲醇为流动相进行梯度洗脱,流速为1 mL/min,进样量为20μL,检测波长210 nm,柱温20℃,试样盘控温:5℃,并对方法的专属性、灵敏性、准确性、重复性、耐用性及适用性进行验证。结果烟酰胺氧化物、ATP、ADP、AMP及烟酰胺分别在质量浓度0.4060~16.2402、0.4110~16.4403、0.4150~16.6010、0.4163~16.6507、0.4028~16.1206μg/mL范围内,质量浓度与峰面积呈现良好的线性关系,线性系数r^(2)值均大于0.998;加标回收率范围分别为98.5%~102.6%、95.6%~104.1%、98.9%~104.6%、100.0%~102.8%、100.6%~101.3%;3批样品中5种杂质含量检测结果分别为0.18%、0.20%、0.16%、0.14%、0.26%;5种杂质的检出限范围为0.04028~0.04163μg/mL,定量限范围为0.4028~0.4163μg/mL,灵敏度高;专属性、重复性和耐用性均良好。结论该方法简便易行、适用性广,适用于NMN中5种有关物质的检测,为提升其质量标准奠定基础,为食品安全提供保障。

白花蛇舌草提取物通过AMPK/ATG5信号通路对急性胰腺炎大鼠肺损伤的保护作用机制研究

目的:通过5’-单磷酸腺苷活化蛋白激酶(AMPK)/自噬相关蛋白5(ATG5)信号通路,探讨白花蛇舌草提取物减轻急性胰腺炎(AP)大鼠肺损伤的机制。方法:建立AP肺损伤大鼠模型,随机分为模型组、提取物(白花蛇舌草提取物)组、3-MA(自噬抑制剂3-甲基腺嘌呤)组、AICAR(AMPK激活剂)组、提取物+AICAR组,每组15只,另取15只大鼠作为假手术组;ELISA检测血清淀粉酶(AMY)、IL-1β、IL-6、IL-18水平;检测大鼠腹水量及肺湿/干重比(W/D);HE观察胰腺及肺组织病理损伤;Western blot检测溶酶体相关膜蛋白2(LAMP2)、自噬底物p62、IL-1β前体蛋白(pro-IL-1β)、胰蛋白酶原活化肽(TAP)、AMPK、p-AMPK、ATG5、自噬标志物LC3-Ⅱ/Ⅰ、泛素特异性蛋白酶10(UPS10)表达。结果:与假手术组相比,模型组大鼠腹水量、肺W/D、胰腺和肺组织病理损伤评分、血清AMY、IL-1β、IL-6、IL-18水平、胰腺组织p62、TAP、pro-IL-1β表达、肺组织pAMPK/AMPK、ATG5、LC3-Ⅱ/Ⅰ、UPS10、pro-IL-1β表达均升高(P<0.05),胰腺和肺组织LAMP2蛋白表达降低(P<0.05);模型大鼠经白花蛇舌草提取物或自噬抑制剂3-MA干预后,上述指标均得到显著改善(P<0.05),且白花蛇舌草提取物的改善效果优于3-MA(P<0.05);而AMPK激活剂AICAR可削弱白花蛇舌草提取物对AP大鼠肺损伤的改善作用(P<0.05)。结论:白花蛇舌草提取物可通过抑制AMPK/ATG5信号通路减轻炎症反应、降低自噬水平改善AP大鼠肺损伤。

Diabetes and inflammatory diseases:An overview from the perspective of Ca^(2+)/3'-5'-cyclic adenosine monophosphate signaling

A large amount of evidence has supported a clinical link between diabetes and inflammatory diseases,e.g.,cancer,dementia,and hypertension.In addition,it is also suggested that dysregulations related to Ca^(2+)signaling could link these diseases,in addition to 3'-5'-cyclic adenosine monophosphate(cAMP)signaling pathways.Thus,revealing this interplay between diabetes and inflammatory diseases may provide novel insights into the pathogenesis of these diseases.Publications involving signaling pathways related to Ca^(2+)and cAMP,inflammation,diabetes,dementia,cancer,and hypertension(alone or combined)were collected by searching PubMed and EMBASE.Both signaling pathways,Ca^(2+)and cAMP signaling,control the release of neurotransmitters and hormones,in addition to neurodegeneration,and tumor growth.Furthermore,there is a clear relationship between Ca^(2+)signaling,e.g.,increased Ca^(2+)signals,and inflammatory responses.cAMP also regulates pro-and anti-inflammatory responses.Due to the experience of our group in this field,this article discusses the role of Ca^(2+)and cAMP signaling in the correlation between diabetes and inflammatory diseases,including its pharmacological implications.As a novelty,this article also includes:(1)A timeline of the major events in Ca^(2+)/cAMP signaling;and(2)As coronavirus disease 2019(COVID-19)is an emerging and rapidly evolving situation,this article also discusses recent reports on the role of Ca^(2+)channel blockers for preventing Ca^(2+)signaling disruption due to COVID-19,including the correlation between COVID-19 and diabetes.

In Vitro Functional Study of Rice Adenosine 5'-Phosphosulfate Kinase

Sulfate can be activated by ATP sulfurylase and adenosine 5'-phosphosulfate kinase(APSK) in vivo. Recent studies suggested that APSK in Arabidopsis thaliana regulated the partition between APS reduction and phosphorylation and its activity can be modulated by cellular redox status. In order to study regulation of APSK in rice(Os APSK), Os APSK1 gene was cloned and its activity was analyzed. Os APSK1 C36 and C69 were found to be the conserved counterparts of C86 and C119, which involved in disulfide formation in At APSK. C36A/C69 A Os APSK1 double mutation was made by site directed mutagenesis. Os APSK1 and its mutant were prokaryotically over-expressed and purified, and then assayed for APS phosphorylation activity. Os APSK1 activity was depressed by oxidized glutathione, while the activity of its mutant was not. Further studies in the case that oxidative stress will fluctuate in vivo 3'-phosphoadenosine-5'-phosphosulfate content, and all APSK isoenzymes have similar regulation patterns are necessary to be performed.

Electrochemical Studies of Effect of Eu^(3+) on Adenosine-5′-Diphosphate at Mercury Electrode

The electrochemical behavior of the adenosine5diphosphate(ADP) was studied in 005 molL-1 MES buffer solution(pH 585) at mercury electrode. There are no reduction and oxidation waves for the adenosine5diphosphate in the range of -04-14 V(vs. Ag/AgCl). In a mixture solution of Eu3+ and ADP(Eu3+ADP=14), a reduction peak is obtained at -078 V. Comparing with the cyclic voltammograms of Eu3+ ions under the same experimental conditions, it is found that the complex of Eu3+ADP can be produced in above solutions between Eu3+ion and ADP. The complex is strongly adsorbed at mercury electrode and has the following electrode reaction mechanism: Eu3++ADPEu3+ADP+e-Eu2+-ADP.

The Adenosine Receptor Agonist 5’-N-Ethylcarboxamide-Adenosine Increases Mouse Serum Total Homocysteine Levels, Which Is a Risk Factor for Cardiovascular Diseases

An increase in total homocysteine (Hcy) levels (protein-bound and free Hcy in the serum) has been identified as a risk factor for vascular diseases. Hcy is a product of the methionine cycle and is a precursor of glutathione in the transsulfuration pathway. The methionine cycle mainly occurs in the liver, with Hcy being exported out of the liver and subsequently bound to serum proteins. When the non-specific adenosine receptor agonist 5’-N-ethylcarboxamide-adenosine (NECA;0.1 or 0.3 mg/kg body weight) was intraperitoneally administered to mice that had been fasted for 16 h, total Hcy levels in the serum significantly increased 1 h after its administration. The NECA treatment may have inhibited transsulfuration because glutathione levels were significantly decreased in the liver. After the intraperitoneal administration of a high dose of NECA (0.3 mg/kg body weight), elevations in total Hcy levels in the serum continued for up to 10 h. The mRNA expression of methionine metabolic enzymes in the liver was significantly reduced 6 h after the administration of NECA. NECA-induced elevations in total serum Hcy levels may be maintained in the long term through the attenuated expression of methionine metabolic enzymes.