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.

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 cellsin vitro.METHODS： NTT 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 ICs0 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.

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.

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 ATP. RESULTS: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-MgCl_2 was added to the perfusate (P<0.01).As compared with the control group,the activities of LDH and AST in the ATP-MgCl_2 group were lower(P<0.05). Furthermore,more severe hepatocyte damage and neutrophil infiltration were observed in the control group.Radioactive [α-^(32)P]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.

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.

Pre-treatment role of inosine triphosphate pyrophosphatase polymorphism for predicting anemia in Egyptian hepatitis C virus patients

AIM: To investigate and clarify, for the first time, the role of inosine triphosphate pyrophosphatase (ITPA ) polymorphism in Egyptian chronic hepatitis C virus (HCV) patients.METHODS:The human genomic DNA of all patients was extracted from peripheral blood cells in order to determine the single nucleotide polymorphism (SNP) of ITPA (rs1127354). SNP genotyping was performed by real time polymerase chain reaction (PCR, ABI TaqMan allelic discrimination kit) for 102 treatment-naive Egyptian patients with chronic HCV. All patients had no evidence of cardiovascular or renal diseases. They received a combination treatment of pegylated interferon α (PEG-IFNα) as a weekly subcutaneous dose plus an oral weight-adjusted dose of ribavirin (RBV). The majority received PEG-IFNα2a (70.6%) while 29.4% received PEG-IFNα2b. The planned duration of treatment was 24-48 wk according to the viral kinetics throughout the course of treatment. Pre-treatment liver biopsy was done for each patient for evaluation of fibrosis stage and liver disease activity. The basal viral load level was detected quantitatively by real time PCR while viral load throughout the treatment course was performed qualitatively by COBAS TaqMan assay. RESULTS: Ninety-three patients (91.2%) had ITPA SNP CC genotype and 9 (8.8%) had non-CC genotype (CA and AA). The percentage of hemoglobin (Hb) decline was higher for CC patients than for non-CC patients, particularly at weeks 4 and 8 (P=0.047 and 0.034, respectively). During the first 12 wk of treatment, CC patients had significantly more Hb decline > 3 g/dL than non-CC patients: 64.5% vs 22.2% at weeks 8 and 12, respectively, (P=0.024 and 0.038). Reduction of the amount of the planned RBV dose was significantly higher for CC patients than non-CC patients during the first 12 wk (18% ± 12.1% vs 8.5% ± 10.2%, P=0.021). The percentage of CC patients with RBV dose reduction was significantly greater than that of non-CC patients (77.4% vs 44.4%, P=0.044). Multivariate analysis identified only the percentage of RBV dose as a predictor for Hb decline. Platelet decline was significantly higher in non-CC patients than CC patients at weeks 12, 24 and 48 (P=0.018, 0.009 and 0.026, respectively). CONCLUSION: Rs1127354 ITPA polymorphism plays a decisive role in protecting against treatment-induced anemia and the need for RBV dose reduction in Egyptian HCV patients.

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.

Role of Deoxyribonucleoside Triphosphates(dNTPs)in Cell Transformation

Deoxyribenucleoside triphosphate (dNTP) pools were measured in normal BALB/c3T3 cells, transformation-treated cells and transformed cells with reverse-phase HPLC. The fluctuation of dNTP pools was similar after transformation treatment with alkylating mutagen glycidyl methacrylate(GMA) or Nmethyl- N'- nitro N- nitrosoguanidine (MNNG ). However,the gap between deoxyguanosine triphosphate + deoxyadenosine triphosphate (dGTP + dATP) pools and deoxythymidine triphosphate + deoxycytidine triphosphate (dTTP + dCTP) pools was greatly intensified. The measurements also indicated that the dNTP pools in transformed cells were quite different from those in normal cells. The results suggested that dNTP pools may play an important role in cell transformation

Symptomatic improvement in an acute, non-traumatic spine pain model with a combination of uridine triphosphate, cytidine monophosphate, and hydroxocobalamin

Rationale: In a previously published trial on spinal acute non-traumatic pain, peripheral neuro- regenerative combination of UTP, CMP and hydroxocobalamin presented unexpected analgesicproperties. Objective: To corroborate analgesiceffects of UTP, CMP and hydroxocobalamin combination in a self-paired evolutionary model. Methods: Mean VAS scores from pretreatment, V2 (5th treatment day) and V3 (10th treatment day) were plotted and statistically analyzed (ANOVA) for differences. PFQ scores from pretreatment, V2, and V3 were analyzed using the chisquare test. Results: The difference between V3 and pretreatment mean VAS scores was statistically significant (p < 0.0001). The improvement in PFQ scores throughout the study was found to be statistically significant (p < 0.0001). Conclusion: The combination of UTP, CMP and hydroxocobalamin seems to have analgesic properties in mediumterm use. The complex peripheral neu-roregenerative pharmacodynamics of this combination provides a plausible basis for this finding. Further randomized studies are needed to explore this combination for the indication of neuropathic pain due to spinal structure involvement.

Polyphosphatase PPN1 of Saccharomyces cerevisiae Is a Deoxyadenosine Triphosphate Phosphohydrolase

The Saccharomyces cerevisiae polyphosphatase PPN1 (uniprot/Q04119) degrades inorganic polyphosphates both by cleaving Pi from the chain end and by fragmenting long-chain polymers into shorter ones. In this study, we have found a new activity of this protein: it releases phosphate from dATP. The dATP phosphohydrolase activity of pure PPN1 was ~7-fold lower compared to the exopolyphosphatase activity. This activity was strongly stimulated by Co2+ ions, as well as by ammonium ions, and inhibited by heparin and pyrophosphate similar to the exopolyphosphatase activity of PPN1. The Km value for dATP was 0.88 ± 0.14 mM. The dATP phosphohydrolase activity in the cells of PPN1-overexpressing yeast strain was several-fold higher than that in the parent strain. The other exopolyphosphatase of S. cerevisiae, PPX1, did not split Pi from dATP.

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.

Adenosine triphosphate-responsive carbon dots nanoreactors for T_(1)-weighted magnetic resonance imaging-guided tumor chemodynamic therapy

There are various strategies to conduct tumor microenvironment(TME)stimulus-responsive(e.g.,acid,H_(2)O_(2)or glutathione)nanoreactors for increasing the efficiency of chemodynamic therapy(CDT).Among these,the exploitation of adenosine triphosphate(ATP,another overexpressed biomarker in TME)-responsive nanoreactors for tumor CDT is still challenging.Herein,the ATP-responsive iron-doped CDs(FeCDs)were firstly prepared and then coassembled with glucose oxidase(GOx)to obtain FeCDs/GOx liposomes as ATP-responsive nanoreactors.Under TME conditions,the nanoreactors initially released FeCDs and GOx.Subsequently,with the existence of ATP,iron ions were rapidly released from the FeCDs to trigger Fenton/Fenton-like reactions for generating·OH.Meanwhile,the T_(1)-weighted magnetic resonance imaging(MRI)was achieved due to the released iron ions.Moreover,the GOx converted endogenous glucose in tumor to gluconic acid and H_(2)O_(2)to satisfy the requirement of·OH generation.In vitro as well as in vivo experiments illustrated that the obtained ATP-responsive CD nanoreactors could be used as a versatile nanotheranostics for simultaneously T_(1)-weighted MRI-guided tumor CDT.This work presents a new ATP-responsive nanoreactor with selfsupplied H_(2)O_(2)for multifunctional nanotheranostic applications.

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 repetitive transcranial magnetic stimulation on adenosine triphosphate content and microtubule associated protein-2 expression after cerebral ischemia-reperfusion injury in rat brain

Background Repetitive transcranial magnetic stimulation （rTMS） research has mainly been focused on the therapeutic effect of psychiatric disorders and Parkinson＇s disease. A few studies have shown that rTMS might protect against delayed neuronal death induced by transient ischemia, enhance long-term potentiation in ischemic conditions and affect regional brain blood flow and metabolism. The aim of this study was to determine the effects of repetitive transcranial magnetic stimulation （rTMS） on adenosine triphosphate （ATP） content and microtubule associated protein-2 （MAP-2） expression in rat brain after middle cerebral artery occlusion （MCAO）/reperfusion. Methods To study the effects of different timecourses of rTMS on ATP content and MAP-2 expression, 90 rats were randomly divided into three groups （30 rats in each group）. To study the effects of multiple rTMS parameters on ATP content and MAP-2 expression, the rats in each group were further divided into six subgroups （five rats each）. The rats were sacrificed at 1-hour, 24-hour and 48-hour intervals after reperfusion, and the brain tissues were collected for the detection of ATP and MAP-2. Results rTMS could significantly increase ATP content and MAP-2 expression in the left brain following ischemic insult （P 〈0.01） and different rTMS parameters had different effects on the ATP level and the MAP-2 expression in the left striatum. A high-frequency rTMS played an important role in MAP-2 expression and ATP preservation. Conclusions This study revealed that rTMS induced significant increase of ATP content and MAP-2 expression in the injured area of the brain, suggesting that the regulation of both ATP and MAP-2 may be involved in the biological mechanism of the effect of rTMS on neural recovery. Therefore, rTMS may become a potential adjunctive therapy for ischemic cerebrovascular disease.

Heat induces adenosine triphosphate release from mast cells in vitro:a putative mechanism for moxibustion

OBJECTIVE:To investigate the role of adenosine triphosphate(ATP) purinergic signaling in mast cells(MCs) modulated by heat to further understand the molecular mechanisms of moxibustion.METHODS:Skin temperatures induced by monkshood cake moxibustion were evaluated by measuring the Neiguan acupoint(PC 6) from 31 participants with a digital thermocouple thermometer.Temperatures of 43 ℃ and 52 ℃ were applied to cultured human leukemia mast cell line HMC-1 in vitro.Calcium fluorescence was applied to detect intracellular Ca^(2+)([Ca^(2+)]_i).Extracellular ATP contents were measured by luciferin-luciferase assay.RESULTS:Maximum skin temperatures mostly ranged from 40-45 ℃,but some reached up to50 ℃.Both 43 ℃,and 52 ℃ induced MC degranulation,which was accompanied by an increase in[Ca^(2+)]_i and ATP release.Complexing extracellular Ca^(2+) with 5 mM ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid(EGTA) inhibited the noxious heat-induced elevation of[Ca^(2+)]_i and prevented the enhanced ATP secretion by those cells at 52℃ but not 43 ℃.CONCLUSION:Monkshood cake moxibustion can generate heat sufficient to trigger cellular events of MCs,including degranulation,[Ca^(2+)]_i elevation,and ATP release,suggesting that purinergic signals originating from MCs are possibly the initiating response of acupoints to moxibustion.

Convenient synthesis of nucleoside 5'-(α-P-thio)triphosphates and phosphorothioate nucleic acids(DNA and RNA)

Modified deoxy-and ribo-nucleoside triphosphates are chemically synthesized in multiple steps due to the protection and deprotection of the nucleoside functionalities.To conveniently synthesize the S-modified triphosphates for enzymatically preparing phosphorothioate DNAs and RNAs(PS-DNA and PS-RNA) as potential therapeutics,herein we report a one-pot strategy to synthesize the deoxy-and ribo-nucleoside 5'-(α-P-thio)triphosphates(dNTPαS and NTPαS) without protecting any nucleoside functionalities.This facile synthesis is achieved by treating the nucleosides with a mild phosphitylating reagent,reacting selectively with the 5'-hydroxyl group of each unprotected nucleoside,followed by sulfurization and hydrolysis to afford the crude dNTPαS and NTPαS analogs(mixtures of Sp and Rp diastereomers).We also demonstrated that after just simple precipitation(without HPLC and ion-exchange purification),the quality of the synthesized dNTPαS and NTPαS analogs is excellent for direct DNA polymerization and RNA transcription,respectively.Since Klenow DNA polymerase and T7 RNA polymerase accept the Sp diastereomers of dNTPαS and NTPαS analogs,respectively,while the Rp diastereomers are neither substrates nor inhibitors,the diastereomerically-pure PS-DNAs and PS-RNAs can be conveniently synthesized enzymatically.

Luminescent silver nanoclusters for efficient detection of adenosine triphosphate in a wide range of pH values

In this work,polymethacrylic acid(PMAA)-templated silver nanoclusters(Ag NCs)were developed as the fluorescent probe for the efficient and sensitive detection of adenosine triphosphate(ATP)in a wide range of pH values.The fluorescence intensity of the Ag NCs could keep stable with pH values ranging from2.5 to 9.3.The detection of ATP was based on the quenching of the fluorescent Ag NCs in the presence of ATP.The fluorescence quenching of the Ag NCs with increasing ATP concentration was studied at pH 2.5,4.5,7.0 and 8.5 which involved a wide pH environment in body fluids.The limit of detection(LOD)for ATP was as low as 0.1 mmol/L in an acidic environment with pH of 2.5 and all the linear correlation coefficients were satisfactory under wide-span pH values from 2.5 to 8.5.In addition,the sensitive determination of ATP was also achieved by adding copper ions(Cu^2+).The high selectivity and rapid detection process proved that the fluorescent probe had great potential to detect ATP in biological samples under different pH conditions.

ELECTRONIC STRUCTURE OF ADENO-SINE TRIPHOSPHATE

It is well known that adenosine triphosphate (ATP) is an important biomolecule.It plays an essential role in the metabolism of living systems and is the prime energy source for numerous physiological processes.The hydrolysis of ATP to adenosine diphosphate (ADP) involves a free energy change of about--9 kcal/mole. Because of such a large energy resulting from the cleavage of P-O bond in ATP, the bond is call-

β-Cyclodextrin polymer based fluorescence enhancement method for sensitive adenosine triphosphate detection

Adenosine triphosphate plays a crucial role in regulation of many biological pathways and has been used as an indicator for many diseases.In this pape r,based on the fact that β-cyclodextrin polymer(polyβ-CD)could significantly enhance pyrene fluorescence through supramolecular assembly(host-gest interaction),a sensitive and facile method for adenosine triphosphate detection has been developed.A 3’-pyrene-labelled ATP-binding aptamer was employed as the fluorescence probe,which could be digested by exonuclease I to obtain mononucleotides,with pyrene attached on.The pyrene attached on mononucleotides could easily enter the hydrophobic cavity of polyβ-CD,accompanied with prominent fluo rescence enhancement.While ATP was introduced,ATP and its aptamer could combine together and the obtained hairpin complex could not be cleaved by exonuclease Ⅰ,The pyrene labelled on the probe could not enter the cavity of polyβ-CD belong to the complex’steric hindrance,accompanied with the weak pyrene’fluorescence.So we could quantify the concentration of adenosine triphosphate facilely by measuring the fluorescence intensity of the system.The detection limit of this method for adenosine triphosphate was 11 μmol/L(S/N=3),The developed method showed sufficient selectivity and could successfully assay adenosine triphosphate in biological samples.The developed method provides a potential platform for biological micromoles assay.

Design of Lipophilic Split Aptamers as Artificial Carriers for Transmembrane Transport of Adenosine Triphosphate

Transmembrane transport plays an important role in many physiological functions,and mimicking this biological process in artificial systems has potential applications in biosensing,drug delivery,and bionic science.Here,a lipophilic split aptamer was developed as a novel transmembrane carrier for adenosine triphosphate(ATP)transport.The ATP carrier comprises two split aptamer fragments and cholesterol tags,with the split aptamers acting as targetrecognition domains to enhance their specific binding capability and the cholesterol tags as hydrophobic domains to facilitate membrane penetration.Giant unilamellar vesicle experiments demonstrated that the ATP carrier-mediated transmembrane transport was concentration-and time-dependent and showed high transport selectivity.Moreover,the artificial carriers were applicable to living cells and facilitated rapid cell internalization of fluorescencelabeled ATP.Furthermore,carrier-mediated ATP transport into ATP-deficient cells enabled recovery of cellular ATP levels and improved cell viability.This study demonstrated the efficacy of an aptamer nanostructure for designing DNA-based synthetic carriers with high selectivity and flexibility.