ATP Upregulation Research Articles

Zeolite Functionalized with Magnesium/Aluminum/Lanthanum Ternary Hydroxide for the Phosphometabolite Profiling of Malignant Neoplastic Serum Samples.

ATP upregulation is a significant driver of aggressive cancer cell phenotypes. Phosphometabolites participate in metabolic pathways and are overexpressed in cancer cell activity. Therefore, developing novel and accurate methods for detecting phosphometabolites in biological fluids is essential. In this research, a novel zeolite composite comprising magnesium, aluminum, and lanthanum hydroxides (MALZ) is developed and used for the first time to enrich phosphorylated metabolites via its inherent interaction with phosphate groups. SEM micrographs show a crystalline cubic structure with a small diameter of 36.62 nm. FTIR analysis confirms the phosphate adsorption and desorption using AMP and ATP as the standards. XRD analysis of MALZ provides structural information about the synthesized composite. Adsorption-desorption parameters, such as pH, shaking time, and MALZ concentration, are optimized to analyze the binding capacity of the fabricated material for phosphorylated metabolites. A kinetic study reveals the rapid and effective AMP and ATP adsorptions on MALZ. The multiple hydroxyl groups of ternary hydroxides and high affinity of lanthanum toward the phosphate group enrich 26 phosphometabolites from serum samples of malignant neoplastic patients. The LC-MS profile shows characteristic phosphometabolites that may act as signatures of cancer-related abnormal metabolic pathways. This study may provide an experimental pathway for detecting metabolites in human body fluids.

Amber (Succinite) Extract Enhances Glucose Uptake through the Up-Regulation of ATP and Down-Regulation of ROS in Mouse C2C12 Cells.

Traditionally, amber (Succinite) has been used to alleviate all types of pain, skin allergies, and headaches. However, no studies have been conducted on its antidiabetic and antioxidant effects. In this study, differentiated skeletal muscle C2C12 cells were used to demonstrate the protective effects of amber (AMB) against H2O2-induced cell death. In addition, the effects of AMB on glucose uptake and ATP production were investigated. Our results showed that AMB at 10, 25, and 50 μg/mL suppressed the elevation of ROS production induced by H2O2 in a dose-dependent manner. Moreover, AMB enhanced glucose utilization in C2C12 cells through the improvement of ATP production and an increase in PGC-1α gene expression resulting in an amelioration of mitochondrial activity. On the other hand, AMB significantly increased the gene expression of glucose transporters GLUT4 and GLUT1. Our finding suggests that AMB can be used as a natural supplement for diabetes treatment and for the promotion of skeletal muscle function.

Microglial metabolic reconfiguration provides a new strategy for the treatment of Alzheimer's disease.

Microglial metabolic reconfiguration provides a new strategy for the treatment of Alzheimer's disease.

Effect of Ocular Hypertension on D-β-Aspartic Acid-Containing Proteins in the Retinas of Rats.

Purpose To investigate the effect of ocular hypertension-induced isomerization of aspartic acid in retinal proteins. Methods Adult Wistar rats with ocular hypertension were used as an experimental model. D-β-aspartic acid-containing proteins were isolated by SDS-PAGE and western blot with an anti-D-β-aspartic acid antibody and identified by liquid chromatography-mass spectrometry analysis. The concentration of ATP was measured by ELISA. Results D-β-aspartic acid was expressed in a protein band at around 44.5 kDa at much higher quantities in the retinas of rats with ocular hypertension than in those of normotensive rats. The 44.5 kDa protein band was mainly composed of α-enolase, S-arrestin, and ATP synthase subunits α and β, in both the ocular hypertensive and normotensive retinas. Moreover, increasing intraocular pressure was correlated with increasing ATP concentrations in the retinas of rats. Conclusion Ocular hypertension affected the expression of proteins containing D-β-aspartic acid, including ATP synthase subunits, and up-regulation of ATP in the retinas of rats.

Role of the mTORC1 complex in satellite cell activation by RNA-induced mitochondrial restoration: dual control of cyclin D1 through microRNAs.

During myogenesis, satellite stem cells (SCs) are induced to proliferate and differentiate to myogenic precursors. The role of energy sensors such as the AMP-activated protein kinase (AMPK) and the mammalian Target of Rapamycin (mTOR) in SC activation is unclear. We previously observed that upregulation of ATP through RNA-mediated mitochondrial restoration (MR) accelerates SC activation following skeletal muscle injury. We show here that during regeneration, the AMPK-CRTC2-CREB and Raptor-mTORC-4EBP1 pathways were rapidly activated. The phosho-CRTC2-CREB complex was essential for myogenesis and activated transcription of the critical cell cycle regulator cyclin D1 (Ccnd1). Knockdown (KD) of either mTORC or its subunit Raptor delayed SC activation without influencing the differentiation program. KD of 4EBP1 had no effect on SC activation but enhanced myofiber size. mTORC1 positively regulated Ccnd1 translation but destabilized Ccnd1 mRNA. These antithetical effects of mTORC1 were mediated by two microRNAs (miRs) targeted to the 3' untranslated region (UTR) of Ccnd1 mRNA: miR-1 was downregulated in mTORC-KD muscle, and depletion of miR-1 resulted in increased levels of mRNA without any effect on Ccnd1 protein. In contrast, miR-26a was upregulated upon mTORC depletion, while anti-miR-26a oligonucleotide specifically stimulated Ccnd1 protein expression. Thus, mTORC may act as a timer of satellite cell proliferation during myogenesis.

The effect of cannabichromene on adult neural stem/progenitor cells

Apart from the psychotropic compound Δ9-tetrahydrocannabinol (THC), evidence suggests that other non-psychotropic phytocannabinoids are also of potential clinical use. This study aimed at elucidating the effect of major non-THC phytocannabinoids on the fate of adult neural stem progenitor cells (NSPCs), which are an essential component of brain function in health as well as in pathology. We tested three compounds: cannabidiol, cannabigerol, and cannabichromene (CBC), and found that CBC has a positive effect on the viability of mouse NSPCs during differentiation in vitro. The expression of NSPC and astrocyte markers nestin and Glial fibrillary acidic protein (GFAP), respectively, was up- and down-regulated, respectively. CBC stimulated ERK1/2 phosphorylation; however, this effect had a slower onset in comparison to typical MAPK stimulation. A MEK inhibitor, U0126, antagonized the up-regulation of nestin but not the down-regulation of GFAP. Based on a previous report, we studied the potential involvement of the adenosine A1 receptor in the effect of CBC on these cells and found that the selective adenosine A1 receptor antagonist, DPCPX, counteracted both ERK1/2 phosphorylation and up-regulation of nestin by CBC, indicating that also adenosine is involved in these effects of CBC, but possibly not in CBC inhibitory effect on GFAP expression. Next, we measured ATP levels as an equilibrium marker of adenosine and found higher ATP levels during differentiation of NSPCs in the presence of CBC. Taken together, our results suggest that CBC raises the viability of NSPCs while inhibiting their differentiation into astroglia, possibly through up-regulation of ATP and adenosine signalling.

Proteomic insights into the stimulatory effect of Tween 80 on mycelial growth and exopolysaccharide production of an edible mushroom Pleurotus tuber-regium

Proteomic analysis was applied to investigate the mechanism of the stimulatory effect of Tween 80 on the mycelial growth and exopolysaccharide production by an edible mushroom Pleurotus tuber-regium. 32 differentially expressed proteins were identified by one-dimension gel electrophoresis. Combined with our previous findings, the up-regulation of heat shock proteins might help to maintain cellular viability under environmental stress. The up-regulation of ATP:citrate lyase isoform 2 could suppress the activity of tricarboxylic acid cycle and, consequently, stimulate exopolysaccharide production. The present results provide important insight to the mechanism by which stimulatory agents (Tween 80) can increase the production of useful fungal metabolites and also fill the gap of our knowledge on the under-developed mushroom proteomics.

Activation of the AMPK regulated metabolic stress response by a small molecule HER2/EGFR tyrosine kinase inhibitor protects cardiac myocytes from apoptotic stimuli

14000 Background: The HER2 receptor tyrosine kinase is a survival factor for human cardiomyocytes, providing a potential explanation for the increased incidence of cardiomyopathy associated with anti-HER2 monoclonal antibody trastuzumab. Here we show that GW2974, a HER2/EGFR TKI, but not trastuzumab activates AMP kinase (AMPK), initiating a metabolic stress response in human cardiomyocytes that protects against TNFa induced cell death. GW2974 stimulates calcium dependent fatty acid oxidation in vitro resulting in upregulation of ATP and in myocardium of GW2974 treated rodents. Methods: Western blot: p-Akt, p-Erk1/2, p-AMPKa and p- eEF2 (Cell Signaling); ERRa, ERR? (R&D Systems); PGC-1 (Chemicon); MCAD (Cayman Chemicals); Heregulin, NF?B, and Actin (Sigma). ATP was performed utilizing a bioluminescence assay kit H52 (Roche). Lipid staining was done with Oil Red O (Sigma). Cells: Au565 breast cancer and primary human cardiomyocytes (HMC) were grown in RPMI supplemented with 15% BFS treatments. BAPTA/AM and Compound C (Calbiochem); GW2974 and TNFa (Sigma); trastuzumab (Genentech). Results: Our results show that treatment with GW2974 activates catabolic pathways by activation of AMPK. AMPK is a key regulator in mitochondrial energy producing pathways in human cardiac cells. Phosphorylation of AMPK resulted in phosphorylation of eEF2, upregulation of ERRa and PGC-1 and upregulation of ATP levels. AMPK activation depends on Ca++ as the calcium chelation abolished it. Trastuzumab and Gleevec failed to activate AMPK survival pathways. In addition, GW2974 protected cardiac cells from TNFa killing, whereas treatment with TNFa and trastuzumab resulted in pervasive cellular death. Inhibition of AMPK by Compound C or siRNA resulted in cardiomyocyte killing. Conclusion: Activation of AMPK and its effects on metabolic pathways and energy production in HMC may explain the apparent reduced risk of cardiotoxicity associated with HER2 TKI compared with trastuzumab in treating patients with HER2 overexpressing breast cancers. Although activation of AMPK protected normal cardiac myocytes, this effect appears to be lethal to sensitive HER2 overexpressing breast cancer cells, which are “addicted” to glycolysis. No significant financial relationships to disclose.

Aldosterone upregulates purinergic responses in larval amphibian skin epithelium.

Bullfrog tadpoles respond to apical application of 100 microM amiloride, acetylcholine (ACh) or ATP with a sharp transient inward (apical to basolateral) cation current. In adult skin, amiloride blockable transepithelial Na+ transport is upregulated by the hormone aldosterone. Tadpoles were treated in vivo with aldosterone and changes in short circuit current (Isc) in response to apical application of ATP were determined. Bullfrog tadpoles were exposed to aldosterone (10(-6) M) for periods ranging from 3 h to 60 h. Skins from 60-h aldosterone-treated animals showed a two- to three-fold increase in apical ATP-activated short circuit current when compared to animals treated with vehicle alone. Sodium replacement with a large, nonpermeable cation resulted in no measurable increase in Isc after exposure to ligand, consistent with ATP activation of an inward cation current and not chloride efflux. Activation/desensitization time courses and treatment with blockers revealed no measurable differences between aldosterone-treated and non-treated skins. Activation by amiloride and ACh gave essentially identical results. Studies with RT/PCR showed significant increases over controls of levels of mRNA associated with P2X channels. Given these data, our working hypothesis is that all three ligands activate the same process that exhibits both purinergic and cholinergic characteristics. These data are consistent with aldosterone upregulation of ATP gated channels expressed in the apical membrane of larval frog skin.

In squid nerves intracellular Mg(2+) promotes deactivation of the ATP-upregulated Na(+)/Ca(2+) exchanger.

We investigated the role of intracellular Mg(2+) (Mg(i)(2+)) on the ATP regulation of Na(+)/Ca(2+) exchanger in squid axons and bovine heart. In squid axons and nerve vesicles, the ATP-upregulated exchanger remains activated after removal of cytoplasmic Mg(2+), even in the absence of ATP. Rapid and complete deactivation of the ATP-stimulated exchange occurs upon readmission of Mg(i)(2+). At constant ATP concentration, the effect of intracellular Mg(2+) concentration ([Mg(2+)](i)) on the ATP regulation of exchanger is biphasic: activation at low [Mg(2+)](i), followed by deactivation as [Mg(2+)](i) is increased. No correlation was found between the above results and the levels of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] measured in nerve membrane vesicles. Incorporation of PtdIns(4,5)P(2) into membrane vesicles activates Na(+)/Ca(2+) exchange in mammalian heart but not in squid nerve. Moreover, an exogenous phosphatase prevents MgATP activation in squid nerves but not in mammalian heart. It is concluded that 1) Mg(i)(2+) is an essential cofactor for the deactivation part of ATP regulation of the exchanger and 2) the metabolic pathway of ATP upregulation of the Na(+)/Ca(2+) exchanger is different in mammalian heart and squid nerves.