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1.
Zhongguo Zhen Jiu ; 44(4): 395-399, 2024 Apr 12.
Article in English, Chinese | MEDLINE | ID: mdl-38621725

ABSTRACT

OBJECTIVES: To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative urinary function in elderly patients undergoing total hip arthroplasty (THA). METHODS: One hundred and eighty elderly patients undergoing unilateral THA without indwelling urinary catheters were randomly assigned to a TEAS group (90 cases, 3 cases dropped out, 4 cases were eliminated) and a sham TEAS group (90 cases, 1 case dropped out, 4 cases were eliminated). Both groups received fascia iliac block and subarachnoid block anesthesia under ultrasound guidance. The patients in the TEAS group were treated with TEAS at Zhongji (CV 3), Guanyuan (CV 4), and bilateral Huiyang (BL 35), Ciliao (BL 32) 30 minutes before anesthesia initiation, with dissperse-dense wave, frequency of 2 Hz/100 Hz, until 30 minutes after surgery. The patients in the sham TEAS group underwent the same procedure with the device applied at the same acupoints but without electrical stimulation. The incidence of postoperative urinary retention (POUR), time to first void, voiding threshold, urinary adenosine triphosphate (ATP) level, postoperative abnormal voiding status (bladder residual volume, re-catheterization rate, nocturia occurrence), and postoperative incidence of urinary tract infection (UTI) and prosthetic joint infection (PJI) were observed in both groups. RESULTS: The incidence of POUR in the TEAS group was lower than that in the sham TEAS group (P<0.05); the time to first void in the TEAS group was shorter than that in the sham TEAS group (P<0.05); the voiding threshold in the TEAS group was lower than that in the sham TEAS group (P<0.05); the urinary ATP level in the TEAS group was higher than that in the sham TEAS group (P<0.05); the bladder residual volume in the TEAS group was lower than that in the sham TEAS group (P<0.05); the nocturia occurrence in the TEAS group was lower than that in the sham TEAS group (P<0.05). However, there was no statistically significant difference in re-catheterization rate, incidence of UTI, and incidence of PJI between the two groups (P>0.05). CONCLUSIONS: TEAS could effectively reduce the occurrence of postoperative urinary retention and improve the postoperative urinary function in elderly patients undergoing THA, which might be related with increasing the urinary ATP level.


Subject(s)
Arthroplasty, Replacement, Hip , Nocturia , Transcutaneous Electric Nerve Stimulation , Urinary Retention , Humans , Aged , Acupuncture Points , Arthroplasty, Replacement, Hip/adverse effects , Transcutaneous Electric Nerve Stimulation/methods , Urinary Retention/etiology , Urinary Retention/therapy , Postoperative Complications/etiology , Postoperative Complications/therapy , Adenosine Triphosphate
2.
Front Cell Infect Microbiol ; 14: 1332381, 2024.
Article in English | MEDLINE | ID: mdl-38357442

ABSTRACT

Visceral leishmaniasis (VL) is the most severe type of leishmaniasis which is caused by infection of Leishmania donovani complex. In the BALB/c mouse model of VL, multinucleated giant cells (MGCs) with heavy parasite infection consist of the largest population of hemophagocytes in the spleen of L. donovani-infected mice, indicating that MGCs provide the parasites a circumstance beneficial for their survival. Although ATP6V0D2 is a demonstrated factor inducing the formation of hemophagocytic MGCs during L. donovani infection, functions of this protein in shaping the infection outcome in macrophages remain unclear. Here we evaluated the influence of upregulated ATP6V0D2 on intracellular survival of the parasites. L. donovani infection-induced hemophagocytosis of normal erythrocytes by macrophages was suppressed by RNAi-based knockdown of Atp6v0d2. The knockdown of Atp6v0d2 did not improve the survival of amastigotes within macrophages when the cells were cultured in the absence of erythrocytes. On the other hand, reduced intracellular survival of amastigotes in macrophages by the knockdown was observed when macrophages were supplemented with antibody-opsonized erythrocytes before infection. There, increase in cytosolic labile iron pool was observed in the L. donovani-infected knocked-down macrophages. It suggests that ATP6V0D2 plays roles not only in upregulation of hemophagocytosis but also in iron trafficking within L. donovani-infected macrophages. Superior access to iron in macrophages may be how the upregulated expression of the molecule brings benefit to Leishmania for their intracellular survival in the presence of erythrocytes.


Subject(s)
Leishmania donovani , Leishmaniasis, Visceral , Animals , Mice , Erythrocytes , Iron/metabolism , Leishmaniasis, Visceral/parasitology , Macrophages/metabolism , Mice, Inbred BALB C , Up-Regulation
3.
J Control Release ; 367: 1-12, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38244844

ABSTRACT

Immunogenic cell death (ICD) is associated with the release of damage-associated molecular patterns, including ATP, to promote an effective immune cycle against tumors. However, tumors have evolved an effective strategy for degrading extracellular immunostimulatory ATP via the ATP-adenosine axis, allowing the sequential action of the ectonucleotidases CD39 to degrade accumulated immunostimulatory ATP into pleiotropic immunosuppressive adenosine. Here, an ingenious dissolving microneedle patch (DMNs) is designed for the intralesional delivery of CD39 inhibitor (sodium polyoxotungstate, POM-1) and ICD inducer (IR780) co-encapsulated solid lipid nanoparticles (P/I SLNs) for antitumor therapy. Upon insertion into the tumor site, IR780 induces ICD modalities with the release of damage-associated molecular patterns from endogenous tissues, which activates the antitumor immune cycle. Simultaneously, POM-1 promotes the liberation of immunostimulatory ATP and lowers the level of immunosuppressive extracellular adenosine, which supported immune control of tumors via recruiting CD39-expressing immune cells. In vivo antitumor studies prove that this platform can effectively eliminate mice melanoma (tumor growth inhibitory rate of 96.5%) and colorectal adenocarcinoma (tumor growth inhibitory rate of 93.5%). Our results shed light on the immunological aspects of combinatorial phototherapy and ATP-adenosine regulation, which will broaden the scope of synergistic antitumor immunotherapy.


Subject(s)
Adenosine , Neoplasms , Animals , Mice , Phototherapy/methods , Neoplasms/therapy , Adenosine Triphosphate/metabolism , Immunotherapy , Cell Line, Tumor
4.
Fitoterapia ; 173: 105813, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38184174

ABSTRACT

Three new formyl phloroglucinol meroterpenoids, eumaidials A-C (1-3), were isolated from the leaves of Eucalyptus globulus subsp. maidenii, along with ten known analogues (4-13). Their chemical structures were determined by various spectral data and electronic circular dichroism calculations. Eumaidial A (1) is the first ß-caryophyllene-based formyl phloroglucinol meroterpenoids from the genus Eucalyptus. Compounds 1-4 and 10 exhibited ATP-citrate lyase inhibitory activities, and compounds 2 and 3 suppressed the hepatocyte lipogenesis.


Subject(s)
Eucalyptus , Multienzyme Complexes , Oxo-Acid-Lyases , Molecular Structure , Eucalyptus/chemistry , Phloroglucinol/pharmacology , Phloroglucinol/chemistry , Plant Leaves/chemistry , Adenosine Triphosphate
5.
Int J Mol Sci ; 25(2)2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38256272

ABSTRACT

Cornelian cherry (Cornus mas L.) fruits, abundant in iridoids and anthocyanins, are natural products with proven beneficial impacts on the functions of the cardiovascular system and the liver. This study aims to assess and compare whether and to what extent two different doses of resin-purified cornelian cherry extract (10 mg/kg b.w. or 50 mg/kg b.w.) applied in a cholesterol-rich diet rabbit model affect the levels of sterol regulatory element-binding protein 1c (SREBP-1c) and CCAAT/enhancer binding protein α (C/EBPα), and various liver X receptor-α (LXR-α), peroxisome proliferator-activated receptor-α (PPAR-α), and peroxisome proliferator-activated receptor-γ (PPAR-γ) target genes. Moreover, the aim is to evaluate the resistive index (RI) of common carotid arteries (CCAs) and aortas, and histopathological changes in CCAs. For this purpose, the levels of SREBP-1c, C/EBPα, ATP-binding cassette transporter A1 (ABCA1), ATP-binding cassette transporter G1 (ABCG1), fatty acid synthase (FAS), endothelial lipase (LIPG), carnitine palmitoyltransferase 1A (CPT1A), and adiponectin receptor 2 (AdipoR2) in liver tissue were measured. Also, the levels of lipoprotein lipase (LPL), visceral adipose tissue-derived serine protease inhibitor (Vaspin), and retinol-binding protein 4 (RBP4) in visceral adipose tissue were measured. The RI of CCAs and aortas, and histopathological changes in CCAs, were indicated. The oral administration of the cornelian cherry extract decreased the SREBP-1c and C/EBPα in both doses. The dose of 10 mg/kg b.w. increased ABCA1 and decreased FAS, CPT1A, and RBP4, and the dose of 50 mg/kg b.w. enhanced ABCG1 and AdipoR2. Mitigations in atheromatous changes in rabbits' CCAs were also observed. The obtained outcomes were compared to the results of our previous works. The beneficial results confirm that cornelian cherry fruit extract may constitute a potentially effective product in the prevention and treatment of obesity-related disorders.


Subject(s)
Cornus , Lagomorpha , Plant Extracts , Animals , Rabbits , Anthocyanins , ATP-Binding Cassette Transporters , CCAAT-Enhancer-Binding Protein-alpha/genetics , Cornus/chemistry , Diet , Fruit/chemistry , Liver , Liver X Receptors/genetics , Plant Extracts/pharmacology , PPAR alpha/genetics , PPAR gamma/genetics , Sterol Regulatory Element Binding Protein 1/genetics
6.
Biol Trace Elem Res ; 202(4): 1335-1344, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37580526

ABSTRACT

A recent report has shown the active site of the beta subunit of mitochondrial ATP synthase is probably the site of action of Cr(III) action, independent of the insulin signaling pathway. This works appears to answer an important question about the mode of action of Cr(III) at a molecular level when supplied in supra-nutritional levels to rodents. However, as with any good research, the research also raises several questions. The relationship between this study and the results of rodent studies of chromium supplementation and between this study and the current understanding the chromium(III) transport and detoxification system are put into perspective.


Subject(s)
Insulin , Mitochondrial Proton-Translocating ATPases , Mitochondrial Proton-Translocating ATPases/metabolism , Insulin/metabolism , Chromium/chemistry , Signal Transduction
7.
Int J Environ Health Res ; 34(3): 1410-1420, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37211801

ABSTRACT

To evaluate the association between ATP2B1 gene polymorphisms and skeletal fluorosis, a cross-sectional study was conducted. In China, 962 individuals were recruited, including 342 cases of skeletal fluorosis. Four TP2BA1 polymorphisms (rs2070759, rs12817819, rs17249754, and rs7136259) were analysed. The results suggested that rs17249754 and rs7136259 were associated with skeletal fluorosis. After controlling confounders, the protective effect of GG genotype in rs17249754 was apparent in individuals over 45 years old, female, with urine fluoride concentration below 1.6 mg/L, serum calcium above 2.25 mmol/L or serum phosphorus between 1.1 and 1.3. Heterozygote TC in rs7136259 increased the risk of skeletal fluorosis in subjects who are elderly, female, with urinary fluoride more than 1.6 mg/L, serum calcium more than 2.25 mmol/L and blood phosphorus between 1.1 and 1.3 mmol/L. Four loci were found to be tightly related by linkage disequilibrium analysis, and the frequency of distribution of haplotype GCGT was lower in the skeletal fluorosis group.


Subject(s)
Bone Diseases, Metabolic , Fluorosis, Dental , Humans , Female , Aged , Middle Aged , Fluorides , Haplotypes , Calcium , Polymorphism, Single Nucleotide , Cross-Sectional Studies , Bone Diseases, Metabolic/genetics , China/epidemiology , Phosphorus , Fluorosis, Dental/epidemiology , Fluorosis, Dental/genetics , Plasma Membrane Calcium-Transporting ATPases/genetics
8.
Intern Med ; 63(1): 71-75, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37121747

ABSTRACT

A 73-year-old woman was referred to our hospital for persistent liver dysfunction. When the patient was 45 years old, her youngest sister had been diagnosed with Wilson disease (WD). The patient therefore underwent several family screening tests, all of which were unremarkable. She had an annual medical checkup and was diagnosed with liver dysfunction and fatty liver at 68 years old. A liver biopsy and genetic testing were performed, and she was diagnosed with WD; chelation therapy was then initiated. In patients with hepatic disorders and a family history of WD, multiple medical examinations should be conducted, as the development of WD is possible regardless of age.


Subject(s)
Hepatolenticular Degeneration , Non-alcoholic Fatty Liver Disease , Female , Humans , Aged , Middle Aged , Hepatolenticular Degeneration/complications , Hepatolenticular Degeneration/diagnosis , Hepatolenticular Degeneration/drug therapy , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/diagnosis , Genetic Testing , Copper , Patients
9.
Purinergic Signal ; 20(1): 83-89, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37074620

ABSTRACT

ATP is a ubiquitous extracellular messenger released in a wide number of pathophysiological conditions. ATP is known to be present in minute amounts in the extracellular space in healthy tissues and in the blood, and to modulate a multiplicity of cell responses. Cell culture systems are widely used to explore purinergic signaling. We show here that currently used fetal bovine sera contain ATP in the 300-1300 pmol/L range. Serum ATP is associated with albumin as well as with microparticle/microvesicle fraction. Serum microparticles/microvesicles affect in vitro cell responses due to their content of miRNAs, growth factors, and other bioactive molecules. ATP is likely to be one of these bioactive factors found in a variable amount in sera of different commercial sources. ATP in serum supports ATP-dependent biochemical reactions such as the hexokinase-dependent phosphorylation of glucose to glucose 6-phosphate, and affects purinergic signaling. These findings show that cells growing in vitro in serum-supplemented media are exposed to varying levels of extracellular ATP, and thus to varying degrees of purinergic stimulation.


Subject(s)
Extracellular Space , Serum Albumin, Bovine , Cells, Cultured , Extracellular Space/metabolism , Adenosine Triphosphate/metabolism , Glucose
10.
J Agric Food Chem ; 72(1): 284-299, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38109331

ABSTRACT

microRNA (miRNA) controls the post-transcriptional translation of mRNA to affect the expression of many genes participating in functional interaction pathways. Selenoproteins are characterized by their antioxidant activity, wherein selenoprotein T (SelT) is an essential membrane-bound selenoprotein serving as a guardian of intracellular homeostasis. During muscle development and regeneration, myoblasts enter the cell cycle and rapidly proliferate. However, the role of SelT in muscle development and selenium (Se) deficiency-induced muscle damage remains poorly investigated. This study established Se deficient broiler models, chicken embryos models, and cultured chicken primary myoblasts in vitro. We showed that Se deficiency induced skeletal muscle damage in broilers, promoted miR-365-3p expression, and downregulated the level of SelT, significantly. The absence of SelT led to the accumulation of mitochondrial superoxide and downregulated mitochondrial dynamics gene expression, which, in turn, induced the disruption of mitochondria potential and blocked the oxidative phosphorylation (OXPHOS) process. Limited ATP production rate caused by mitochondrial ROS overproduction went along with cell cycle arrest, cell proliferation slowness, and myocyte apoptosis increase. Using Mito-TEMPO for mitochondrial ROS elimination could effectively mitigate the above adverse reactions and significantly restore the proliferation potential of myoblasts. Moreover, we identified miR-365-3p, a miRNA that targeted SelT mRNA to inhibit myoblast proliferation by disrupting intracellular redox balance. The omics analysis results showed that Se deficiency led to the significant enrichment of "cell cycle", "oxidative stress response", and "oxidative phosphorylation" pathway genes. Finally, we proved that the effect of the miR-365-3p/SelT signaling axis on muscle development did exist in the chicken embryo stage. In summary, our findings revealed that miR-365-3p was involved in broiler skeletal muscle damage in Se deficiency by targeting SelT, and SelT, serving as an intracellular homeostasis guardian, resisted mitochondrial oxidative stress, and protected ATP generation, promoting myoblast proliferation and inhibiting apoptosis. This study provides an attractive target for the cultivated meat industry and regenerative medicine.


Subject(s)
MicroRNAs , Selenium , Chick Embryo , Animals , Chickens/genetics , Chickens/metabolism , Reactive Oxygen Species , Selenium/pharmacology , MicroRNAs/genetics , MicroRNAs/metabolism , Diet , Selenoproteins/genetics , Selenoproteins/metabolism , RNA, Messenger , Cell Proliferation , Apoptosis , Myoblasts/metabolism , Adenosine Triphosphate
11.
Biol Trace Elem Res ; 202(4): 1318-1324, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38133723

ABSTRACT

The micronutrient trivalent chromium, 3 + (Cr(III)), is postulated to play a role in carbohydrate, lipid, and protein metabolism. Although the mechanisms by which chromium mediates its actions are largely unknown, previous studies have suggested that pharmacological doses of chromium improve cardiometabolic symptoms by augmenting carbohydrate and lipid metabolism. Activation of AMP-activated protein kinase (AMPK) was among the many mechanisms proposed to explain the salutary actions of chromium on carbohydrate metabolism. However, the molecular pathways leading to the activation of AMPK by chromium remained elusive. In an elegant series of studies, Sun and coworkers recently demonstrated that chromium augments AMPK activation by binding to the beta-subunit of ATP synthase and inhibiting its enzymatic activity. This mini-review attempts to trace the evolving understanding of the molecular mechanisms of chromium leading to the hitherto novel pathway unraveled by Sun and coworkers and its potential implication to our understanding of the biological actions of chromium.


Subject(s)
AMP-Activated Protein Kinases , Chromium , Chromium/chemistry , Mitochondrial Proton-Translocating ATPases/metabolism , Lipid Metabolism , Carbohydrates , Adenosine Triphosphate , Carbohydrate Metabolism
12.
BMC Med Genomics ; 16(1): 307, 2023 11 30.
Article in English | MEDLINE | ID: mdl-38037104

ABSTRACT

BACKGROUND: ATP7B is a copper-transporting protein that contributes to the chemo-resistance of human cancer cells. It remains unclear what the molecular mechanisms behind ATP7B are in cancer, as well as its role in human pan-cancer studies. METHODS: Our study evaluated the differential expression of ATP7B in cancer and paracancerous tissues based on RNA sequencing data from the GTEx and TCGA. Kaplan-Meier and Cox proportional hazards regressions were used to estimate prognostic factors associated with ATP7B.The correlations between the expression of ATP7B and immune cell infiltration, tumor mutation burden, microsatellite instability and immune checkpoint molecules were analyzed. Co-expression networks and mutations in ATP7B were analyzed using the web tools. An analysis of ATP7B expression difference on drug sensitivity on tumor cells was performed using the CTRP, GDSC and CMap database. RESULTS: ATP7B expression differed significantly between cancerous and paracancerous tissues. The abnormal expression of ATP7B was linked to prognosis in LGG and KIRC. Infiltration of immune cells, tumor mutation burden, microsatellite instability and immunomodulators had all been linked to certain types of cancer. Cancer cells exhibited a correlation between ATP7B expression and drug sensitivity. CONCLUSION: ATP7B might be an immunotherapeutic and prognostic biomarker based on its involvement in cancer occurrence and development.


Subject(s)
Microsatellite Instability , Neoplasms , Humans , Immunotherapy , Neoplasms/genetics , Neoplasms/therapy , Adjuvants, Immunologic , Databases, Factual , Prognosis
13.
Int J Mol Sci ; 24(24)2023 Dec 09.
Article in English | MEDLINE | ID: mdl-38139129

ABSTRACT

The pyrimidine nucleoside uridine and its phosphorylated derivates have been shown to be involved in the systemic regulation of energy and redox balance and promote the regeneration of many tissues, including the myocardium, although the underlying mechanisms are not fully understood. Moreover, rearrangements in mitochondrial structure and function within cardiomyocytes are the predominant signs of myocardial injury. Accordingly, this study aimed to investigate whether uridine could alleviate acute myocardial injury induced by isoprenaline (ISO) exposure, a rat model of stress-induced cardiomyopathy, and to elucidate the mechanisms of its action related to mitochondrial dysfunction. For this purpose, a biochemical analysis of the relevant serum biomarkers and ECG monitoring were performed in combination with transmission electron microscopy and a comprehensive study of cardiac mitochondrial functions. The administration of ISO (150 mg/kg, twice with an interval of 24 h, s.c.) to rats caused myocardial degenerative changes, a sharp increase in the serum cardiospecific markers troponin I and the AST/ALT ratio, and a decline in the ATP level in the left ventricular myocardium. In parallel, alterations in the organization of sarcomeres with focal disorganization of myofibrils, and ultrastructural and morphological defects in mitochondria, including disturbances in the orientation and packing density of crista membranes, were detected. These malfunctions were improved by pretreatment with uridine (30 mg/kg, twice with an interval of 24 h, i.p.). Uridine also led to the normalization of the QT interval. Moreover, uridine effectively inhibited ISO-induced ROS overproduction and lipid peroxidation in rat heart mitochondria. The administration of uridine partially recovered the protein level of the respiratory chain complex V, along with the rates of ATP synthesis and mitochondrial potassium transport, suggesting the activation of the potassium cycle through the mitoKATP channel. Taken together, these results indicate that uridine ameliorates acute ISO-induced myocardial injury and mitochondrial malfunction, which may be due to the activation of mitochondrial potassium recycling and a mild uncoupling leading to decreased ROS generation and oxidative damage.


Subject(s)
Cardiomyopathies , Mitochondria, Heart , Rats , Animals , Isoproterenol/adverse effects , Mitochondria, Heart/metabolism , Uridine/pharmacology , Uridine/metabolism , Reactive Oxygen Species/metabolism , Cardiomyopathies/metabolism , Potassium/metabolism , Adenosine Triphosphate/metabolism
14.
Indian J Pharmacol ; 55(5): 315-321, 2023.
Article in English | MEDLINE | ID: mdl-37929410

ABSTRACT

OBJECTIVES: The goal of the research is to investigate the protocatechuic acid (PCA) potential action, a phenolic acid derivative, on pain induced by neuropathy and to determine its efficacy on activation of KATP type channels and A1 receptors. MATERIALS AND METHODS: Neuropathic pain by cause of sciatic nerve damage was induced in Sprague-Dawley rats. Anti-allodynic and anti-hyperalgesic effects were evaluated with von Frey apparatus and Hargreave's plantar test apparatus, respectively. The effects of PCA at the doses of 75, 150 and 300 mg/kg, carbamazepine at the doses of 50 and 100 mg/kg, combination of low effective doses of PCA and carbamazepine were tested. Pretreatments 3 µg/kg DPCPX as adenosine A1 receptor antagonist and 60.7 nmol glibenclamide as KATP channel blocker were applied for mechanistic studies. RESULTS: PCA showed anti-allodynic and anti-hyperalgesic effects without impairing locomotor activity. In addition, the combination treatment was found to be more effective than the separate individual treatments of drugs. KATP channel activation related with A1 receptor stimulation makes a significant contribution to the anti-allodynia and anti-hyperalgesia induced by PCA. CONCLUSIONS: It can be said that PCA has similar effects with carbamazepine, which is used in clinical practice, and that PCA can take place as an adjuvant drug in neuropathic pain with the combination group. In addition, it is seen that the undesirable effects that drugs can cause alone can be avoided and a more effective treatment potential can be created with multiple mechanisms.


Subject(s)
Neuralgia , Rats , Animals , Rats, Sprague-Dawley , Neuralgia/drug therapy , Hyperalgesia/drug therapy , Carbamazepine/therapeutic use , Adenosine Triphosphate/therapeutic use
15.
Molecules ; 28(22)2023 Nov 08.
Article in English | MEDLINE | ID: mdl-38005208

ABSTRACT

The integration of phosphorus chemistry with the mechanism of ATP synthesis/hydrolysis requires dynamical information during ATP turnover and catalysis. Oxygen exchange reactions occurring at ß-catalytic sites of the FOF1-ATP synthase/F1-ATPase imprint a unique record of molecular events during the catalytic cycle of ATP synthesis/hydrolysis. They have been shown to provide valuable time-resolved information on enzyme catalysis during ATP synthesis and ATP hydrolysis. The present work conducts new experiments on oxygen exchange catalyzed by submitochondrial particles designed to (i) measure the relative rates of Pi-ATP, Pi-HOH, and ATP-HOH isotope exchanges; (ii) probe the effect of ADP removal on the extent of inhibition of the exchanges, and (iii) test their uncoupler sensitivity/resistance. The objectives have been realized based on new experiments on submitochondrial particles, which show that both the Pi-HOH and ATP-HOH exchanges occur at a considerably higher rate relative to the Pi-ATP exchange, an observation that cannot be explained by previous mechanisms. A unifying explanation of the kinetic data that rationalizes these observations is given. The experimental results in (ii) show that ADP removal does not inhibit the intermediate Pi-HOH exchange when ATP and submitochondrial particles are incubated, and that the nucleotide requirement of the intermediate Pi-HOH exchange is adequately met by ATP, but not by ADP. These results contradicts the central postulate in Boyer's binding change mechanism of reversible catalysis at a F1 catalytic site with Keq~1 that predicts an absolute requirement of ADP for the occurrence of the Pi-HOH exchange. The prominent intermediate Pi-HOH exchange occurring under hydrolytic conditions is shown to be best explained by Nath's torsional mechanism of energy transduction and ATP synthesis/hydrolysis, which postulates an essentially irreversible cleavage of ATP by mitochondria/particles, independent from a reversible formation of ATP from ADP and Pi. The explanation within the torsional mechanism is also shown to rationalize the relative insensitivity of the intermediate Pi-HOH exchange to uncouplers observed in the experiments in (iii) compared to the Pi-ATP and ATP-HOH exchanges. This is shown to lead to new concepts and perspectives based on ligand displacement/substitution and ligand permutation for the elucidation of the oxygen exchange reactions within the framework of fundamental phosphorus chemistry. Fast mechanisms that realize the rotation/twist, tilt, permutation and switch of ligands, as well as inversion at the γ-phosphorus synchronously and simultaneously and in a concerted manner, have been proposed, and their stereochemical consequences have been analyzed. These considerations take us beyond the binding change mechanism of ATP synthesis/hydrolysis in bioenergetics.


Subject(s)
Oxidative Phosphorylation , Phosphorus , Hydrolysis , Ligands , Adenosine Triphosphate/metabolism , Kinetics , Oxygen
17.
Front Immunol ; 14: 1244068, 2023.
Article in English | MEDLINE | ID: mdl-37854595

ABSTRACT

Bovine besnoitiosis is a re-emerging cattle disease caused by the cyst-forming apicomplexan parasite Besnoitia besnoiti. Neutrophil extracellular trap (NET) formation represents an efficient innate immune mechanism of polymorphonuclear neutrophils (PMN) against apicomplexan parasites, including B. besnoiti. PMN purinergic signaling was proposed as a critical factor for NET formation. One important purinergic ligand is ATP, which is recognized as a danger signal and released into the extracellular space acting as an autocrine/paracrine signaling molecule. ATP-driven effects on PMN via the nucleotide P2 receptor family include chemotaxis, reactive oxygen species (ROS) production, and NET formation. So far, data on both PMN ATP concentrations and the role of ATP as a key modulator of purinergic signaling in B. besnoiti tachyzoite-triggered bovine NETosis is scarce. Current data showed that B. besnoiti tachyzoite exposure to bovine PMN neither changed total PMN ATP nor extracellular ATP quantities even though it significantly triggered NET formation. Moreover, B. besnoiti tachyzoite-exposed PMN revealed enhanced oxygen consumption rates (OCR) as quantified by the Seahorse metabolic analyzer. Exogenous supplementation of ATP or non-hydrolizable ATP (ATPγS) led to increased extracellular acidification rates (ECAR) but failed to alter tachyzoite-induced oxidative responses (OCR) in exposed PMN. In addition, exogenous supplementation of ATPγS, but not of ATP, boosted B. besnoiti tachyzoite-induced anchored NET formation. Referring to purinergic signaling, B. besnoiti tachyzoite-triggered anchored NET formation revealed P2X1 purinergic as receptor-dependent since it was blocked by the P2X1 inhibitor NF449 at an IC50 of 1.27 µM. In contrast, antagonists of P2Y2, P2Y6, P2X4, and P2X7 purinergic receptors all failed to affect parasite-driven NETosis. As an interesting finding, we additionally observed that B. besnoiti tachyzoite exposure induced PMN clustering in a P2X1-dependent manner. Thus, we identified P2X1 purinergic receptor as a pivotal molecule for both B. besnoiti tachyzoite-induced PMN clustering and anchored NET formation.


Subject(s)
Extracellular Traps , Sarcocystidae , Animals , Cattle , Neutrophils , Besnoitia , Sarcocystidae/metabolism , Adenosine Triphosphate/metabolism , Receptors, Purinergic/metabolism
18.
Cryobiology ; 113: 104593, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37844752

ABSTRACT

This study determined the individual and combined effects of extracellular adenosine triphosphate (ATP) and quercetin (QUE) on the quality of post-thawed sperm and the fertilization potential of Lohi rams. In experiment 1, semen samples from four Lohi rams were pooled and extended with different concentrations of ATP or QUE (control; no ATP or QUE, 1 or 2 mM ATP and 10 or 20 µM QUE). In experiment 2, pooled semen samples were extended with various combinations of ATP and QUE (control; no ATP and QUE, 1 mM ATP + 10 µM QUE, 1 mM ATP + 20 µM QUE, 2 mM ATP + 10 µM QUE and 2 mM ATP + 20 µM QUE). All samples in both experiments were cryopreserved and analyzed for post-thawed sperm quality. In experiment 3, the best combination of ATP and QUE from experiment 2 was to extend semen, which was then used for laparoscopic insemination in estrus-synchronized ewes (n = 83). The results of experiment 1 showed that 1 mM ATP and 20 µM QUE treatments resulted in higher total motility, progressive motility, viability, plasma membrane intactness (PMI), and motion kinetics (VCL, VSL, VAP, LIN, and STR) compared to other treatments (p < 0.05). In experiment 2, the 1 mM ATP +10 µM QUE-treated group exhibited significantly higher total and progressive motility, PMI, and motion kinetics (VSL, VCL, VAP, STR, and BCF) compared to the control group (p < 0.05). In experiment 3, the fertilizing potential of sperms treated with 1 mM ATP +10 µM QUE was greater than that of untreated controls (58.1% vs. 27.5%, respectively, p-value = 0.012). In conclusion, the quality of post-thawed ram semen is enhanced when the extender is supplemented with extracellular 1 mM ATP and 20 µM QUE, whether used separately or in combination with 1 mM ATP and 10 µM QUE. Furthermore, the inclusion of 1 mM ATP and 10 µM QUE together in the extender significantly improves in vivo fertility in Lohi ram.


Subject(s)
Semen Preservation , Semen , Sheep , Animals , Male , Female , Quercetin/pharmacology , Semen Preservation/veterinary , Semen Preservation/methods , Cryopreservation/methods , Spermatozoa , Fertilization , Sheep, Domestic , Adenosine Triphosphate , Sperm Motility
19.
Int J Biol Macromol ; 253(Pt 4): 127049, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37758110

ABSTRACT

Naturally occurring naphthoquinones, shikonin and alkannin, are important ingredients of traditional Chinese medicine Zicao. These constituents are reported to have many therapeutic uses, such as wound healing; scar treatment; and anti-inflammation, anti-acne, anti-ulcer, anti-HIV, anticancer, and antibacterial properties. The primary objective of this investigation was to explore the effect of shikonin and alkannin on Escherichia coli ATP synthase and its cell growth. Shikonin caused complete (100 %) inhibition, and alkannin caused partial (79 %) inhibition of wild-type E. coli ATP synthase. Both caused partial (4 %-27 %) inhibition of ATP synthase with genetically modified phytochemical binding site. The growth inhibition of strains expressing normal, deficient, and mutant ATP synthase by shikonin and alkannin, corroborated the inhibition observed in isolated normal wild-type and mutant ATP synthase. Trivial inhibition of mutant enzymes indicated αR283D, αE284R, ßV265Q, and γT273A are essential for formation of the phytochemical binding site where shikonin and alkannin bind. Further, shikonin was a potent inhibitor of ATP synthase than alkannin. The antimicrobial properties of shikonin and alkannin were tied to the binding at phytochemical site of microbial ATP synthase. Selective targeting of bacterial ATP synthase by shikonin and alkannin may be an advantageous alternative to address the antibiotic resistance issue.


Subject(s)
Escherichia coli , Naphthoquinones , Naphthoquinones/pharmacology , Naphthoquinones/chemistry , Phytochemicals/pharmacology , Adenosine Triphosphate/pharmacology
20.
Sensors (Basel) ; 23(17)2023 Aug 27.
Article in English | MEDLINE | ID: mdl-37687909

ABSTRACT

A uniformly oriented purple membrane (PM) monolayer containing photoactive bacteriorhodopsin has recently been applied as a sensitive photoelectric transducer to assay color proteins and microbes quantitatively. This study extends its application to detecting small molecules, using adenosine triphosphate (ATP) as an example. A reverse detection method is used, which employs AuNPs labeling and specific DNA strand displacement. A PM monolayer-coated electrode is first covalently conjugated with an ATP-specific nucleic acid aptamer and then hybridized with another gold nanoparticle-labeled nucleic acid strand with a sequence that is partially complementary to the ATP aptamer, in order to significantly minimize the photocurrent that is generated by the PM. The resulting ATP-sensing chip restores its photocurrent production in the presence of ATP, and the photocurrent recovers more effectively as the ATP concentration increases. Direct and single-step ATP detection is achieved in 15 min, with detection limits of 5 nM and a dynamic range of 5 nM-0.1 mM. The sensing chip exhibits high selectivity against other ATP analogs and is satisfactorily stable in storage. The ATP-sensing chip is used to assay bacterial populations and achieves a detection limit for Bacillus subtilis and Escherichia coli of 102 and 103 CFU/mL, respectively. The demonstration shows that a variety of small molecules can be simultaneously quantified using PM-based biosensors.


Subject(s)
Bacteriorhodopsins , Metal Nanoparticles , Nucleic Acids , Gold , DNA , Adenosine Triphosphate , Escherichia coli
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