Reduced Adenosine Triphosphate Research Articles

Reducing the Impacts of Biofouling in RO Membrane Systems through In Situ Low Fluence Irradiation Employing UVC-LEDs.

Biofouling is a major concern for numerous reverse osmosis membrane systems. UV pretreatment of the feed stream showed promising results but is still not an established technology as it does not maintain a residual effect. By conducting accelerated biofouling experiments in this study, it was investigated whether low fluence UV in situ treatment of the feed using UVC light-emitting diodes (UVC-LEDs) has a lasting effect on the biofilm. The application of UVC-LEDs for biofouling control is a novel hybrid technology that has not been investigated, yet. It could be shown that a low fluence of 2 mJ∙cm−2 delays biofilm formation by more than 15% in lab-scale experiments. In addition, biofilms at the same feed channel pressure drop exhibited a more than 40% reduced hydraulic resistance. The delay is probably linked to the inactivation of cells in the feed stream, modified adsorption properties or an induced cell cycle arrest. The altered hydraulic resistance might be caused by a change in the microbial community, as well as reduced adenosine triphosphate levels per cells, possibly impacting quorum sensing and extracellular polymeric substances production. Due to the observed biofilm attributes, low fluence UV-LED in situ treatment of the feed stream seems to be a promising technology for biofouling control.

Mitochondria-Targeted Polyamidoamine Dendrimer-Curcumin Construct for Hepatocellular Cancer Treatment.

Mitochondrial malfunction plays a crucial role in cancer development and progression. Cancer cells show a substantially higher mitochondrial activity and greater mitochondrial transmembrane potential than normal cells. This concept can be exploited for targeting cytotoxic drugs to the mitochondria of cancer cells using mitochondrial-targeting compounds. In this study, a polyamidoamine dendrimer-based mitochondrial delivery system was prepared for curcumin using triphenylphosphonium ligands to improve the anticancer efficacy of the drug in vitro and in vivo. For the in vitro evaluations, various methods, such as viability assay, confocal microscopy, flow cytometry, reactive oxygen species (ROS), and real-time polymerase chain reaction analyses, were applied. Our findings showed that the targeted-dendrimeric curcumin (TDC) could successfully deliver and colocalize the drug to the mitochondria of the cancer cells, and selectively induce a potent apoptosis and cell cycle arrest at G2/M. Moreover, at a low curcumin dose of less than 25 μM, TDC significantly reduced adenosine triphosphate and glutathione, and increased the ROS level of the isolated rat hepatocyte mitochondria. The in vivo studies on the Hepa1-6 tumor-bearing mice also indicated a significant tumor suppression effect and the highest median survival days (Kaplan-Meier survival estimation and log-rank test) after treatment with the TDC construct compared to the free curcumin and untargeted construct. Besides its targeted nature and safety, the expected improved solubility and stability represent the prepared targeted-dendrimeric construct as an up-and-coming candidate for cancer treatment. The results of this study emphasize the promising route of mitochondrial targeting as a practical approach for cancer therapy, which can be achieved by optimizing the delivery method.

Mortality Among Veterans with a Diagnosis of Pyruvate Kinase (PK) Deficiency: A Real-World Study Using US Veterans Health Administration Data

Background: Pyruvate kinase (PK) deficiency is a rare, inherited disorder caused by autosomal recessive mutations in the PKLR gene, whereby a glycolytic defect causes reduced adenosine triphosphate levels and leads to hemolytic anemia. Patients with PK deficiency can experience serious complications associated with the disease and its treatment, including osteoporosis, pulmonary hypertension, sepsis, iron overload, and liver cirrhosis. The current standard of care for PK deficiency is supportive, including blood transfusions, splenectomy, iron chelation therapy and/or interventions for other disease-related morbidity. There is no approved therapy for this condition. Identifying PK deficiency in real-world data is challenging due to a lack of diagnosis codes and treatments that are specific to PK deficiency. As a result, population-based studies of PK deficiency using claims or electronic health record databases are limited. In addition, data on mortality in this patient population are lacking and limited to a few individual case reports. This study aimed to identify patients with a PK deficiency diagnosis as documented by physicians and to compare their mortality to an age- and gender-matched cohort of individuals without PK deficiency. Methods: Patients with ≥ 1 diagnosis code related to PK deficiency (i.e., anemia due to disorders of glycolytic enzymes [International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) D55.2], other hemolytic anemias due to enzyme deficiency [ICD-9-CM 282.3], or unspecified hereditary hemolytic anemia [ICD-9-CM 282.9, ICD-10-CM D58.9]) between January 1995 and July 2019 were selected from the US Veterans Health Administration (VHA) database. To be considered for inclusion, physicians' notes were required to contain the words "pyruvate", "kinase", and "deficiency." A manual review of these physicians' notes was performed to identify patients with a physician-documented diagnosis of PK deficiency (PK deficiency cohort). The index date for the PK deficiency cohort was defined as the date of the first medical record with a diagnosis code related to PK deficiency. Each patient in the PK deficiency cohort was matched 1:5 by age at index, sex, and index year (± 1 year) to patients from the general VHA population with no diagnosis codes related to PK deficiency (non-PK deficiency cohort). The index date for the non-PK deficiency cohort was defined as a random visit date during their match's index year. Survival time from the index date was compared between the PK deficiency cohort and their non-PK deficiency cohort matches using a univariate Cox proportional hazards model with robust standard error estimation. Results: A total of 18 patients met inclusion criteria for the PK deficiency cohort and were matched to 90 individuals in the non-PK deficiency cohort. Baseline characteristics for both cohorts are shown in the Table. For both cohorts, the mean age at index was 57 years and 94% of patients were male; 83-85% were white and the mean Charlson Comorbidity Index score was 0.4-0.5 (no significant differences between cohorts). Imbalances remained between the two cohorts with regard to region and body mass index. The median follow-up was 6.0 years for the PK deficiency cohort and 8.0 years for the non-PK deficiency cohort. Over the follow-up period, there were 9 (50%) observed deaths in the PK deficiency cohort and 28 (31%) observed deaths in the non-PK deficiency cohort. The median time until death was 10.9 years for the PK deficiency cohort and 17.1 years for the non-PK deficiency cohort; the Kaplan-Meier curves for both cohorts are shown in the Figure. Patients in the non-PK deficiency cohort had a significantly longer time to death than the PK deficiency cohort (hazard ratio: 2.3; p = 0.0306); 10 years after index, 42% of patients in the PK deficiency cohort had died compared with 28% of those in the non-PK deficiency cohort. Conclusions: The results of this study suggest that patients with PK deficiency may be at an increased risk of mortality. Further research to understand cause of death in this population is warranted, as is the replication of this study using larger sample sizes and other real-world data sources that better represent females and the pediatric and adolescent PK deficiency age groups. Disclosures Zagadailov: Agios Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Boscoe:Agios Pharmaceuticals: Current Employment, Current equity holder in private company. Garcia-Horton:Agios Pharmaceuticals: Consultancy; Analysis Group, Inc.: Current Employment. Shi:Agios Pharmaceuticals: Consultancy; Analysis Group, Inc.: Current Employment. Liu:Analysis Group, Inc.: Consultancy. Shi:Analysis Group, Inc.: Consultancy. Macaulay:Agios Pharmaceuticals: Consultancy; Analysis Group, Inc.: Current Employment.

Capsaicin Regulates Mitochondrial Fission to Promote Melanoma Cell Apoptosis

Abstract Objective: Capsaicin (CPS) is a major component of the red pepper, and its anti-tumor property has been confirmed. However, the underlying mechanism of this anti-tumor effect has not been fully clarified, so we conducted this study to evaluate the role of mitochondrial fission and subsequent mitochondrial dysfunction in CPS-induced apoptosis of melanoma cells. Methods: Two melanoma cell lines and melanocytes were treated with CPS alone or in combination with ruthenium red (a transient receptor potential vanilloid 1 [TRPV] antagonist), Z-VAD-FMK (a pan-caspase inhibitor), or N-acetyl-L-cysteine (an antioxidant). Cell vitality was tested using a cell counting kit-8 assay. The expression levels of related proteins were examined by Western blotting. Apoptosis, intracellular reactive oxygen species, mitochondrial membrane potential, adenosine triphosphate levels, and mitochondrial dynamics were analyzed by flow cytometry, luminometry, and confocal laser microscopy, respectively, and compared between groups. Results: CPS treatment significantly inhibited the vitality of melanoma cells (For A2058 cells: 0 vs. 120 μmol/L: [100.00% ± 0%] vs. [51.02% ± 6.40%], P < 0.05; For WM35 cells: 0 vs. 120 μmol/L: [100.00% ± 0%] vs. [51.80% ± 3.45%], P < 0.05) but exerted less impact on normal melanocytes. CPS promoted melanoma cell apoptosis through TRPV channels and the caspase cascade. CPS treatment then led to TRPV channel-dependent mitochondrial dysfunction with an increase in reactive oxygen species generation (For A2058 cells: CPS vs. CPS+RR: [2.34 ± 0.30] vs. [1.34 ± 0.12], P < 0.05; For WM35 cells: CPS vs. CPS+RR: [2.25 ± 0.25] vs. [1.65 ± 0.13], P < 0.05), dissipation of the mitochondrial membrane potential (Control vs. CPS: [1.00 ± 0] vs. [0.61 ± 0.08], P < 0.05), and adenosine triphosphate reduction (P < 0.05). In addition, reactive oxygen species generation contributed to CPS-induced melanoma cell apoptosis. Mitochondrial fission was subsequently proved to connect CPS treatment to mitochondrial dysfunction, which was also TRPV channel-dependent, thereby inducing melanoma cell apoptosis. Conclusion: Our study highlights the role of mitochondrial fission and its related mitochondrial dysfunction in mediating the pro-apoptotic effect of CPS in melanoma. These findings deepen our understanding of the mechanisms underlying the anti-tumor activity of CPS and indicate the clinical relevancy of extending the use of this agent for cancer therapy.

Evaluating adenosine triphosphate bioluminescence for biomonitoring in potable water systems

Abstract The application of adenosine triphosphate (ATP) bioluminescence technology as a rapid microbiological activity monitor within a potable water system has been demonstrated. ATP measurements were taken pre- and post-infrastructure improvements within a watershed and throughout two potable water systems from source to tap. A reduction in ATP, as measured by relative light units, was identified post-infrastructure improvements. Peak ATP values for the watershed were found within the reservoirs. The treated source water remained biologically stable throughout the distribution system, with peaks attributed to nitrification. A mathematical model for predicting microbial ATP using pH, temperature, and alkalinity, was developed for the watershed studied, with an adjusted R2 of 0.84 at a 95% confidence level. Overall, ATP bioluminescence technology was found to be a suitable candidate for rapid microbiological activity testing in drinking water systems; however, technological limitations remain with respect to reproducibility that should be addressed prior to full-scale implementation.

Promotion of Mitochondrial Protection by Emodin in Methylglyoxal-Treated Human Neuroblastoma SH-SY5Y Cells: Involvement of the AMPK/Nrf2/HO-1 Axis.

Mitochondrial dysfunction is part of the mechanism of several human diseases. This negative circumstance may be induced by certain toxicants, as methylglyoxal (MG). MG is a reactive dicarbonyl presenting both endogenous and exogenous sources and is also able to induce protein cross-linking and glycation. Emodin (EM; 1,3,8-trihydroxy-6-methylanthracene-9,10-dione; C15H10O5) is a cytoprotective agent. Nonetheless, it was not previously demonstrated whether EM would be able to promote mitochondrial protection in cells challenged with MG. Therefore, we investigated here whether and how EM would prevent the MG-induced mitochondrial collapse in the human neuroblastoma SH-SY5Y cells. We found that a pretreatment (for 4h) with EM at 40μM prevented the MG-induced mitochondrial dysfunction (i.e., decreased activity of the complexes I and V, reduced adenosine triphosphate levels, and loss of mitochondrial membrane potential) in the SH-SY5Y cells. EM also prevented the redox impairment induced by MG in mitochondrial membranes. Inhibiting the adenosine monophosphate-activated protein kinase (AMPK) or silencing of the nuclear factor erythroid 2-related factor 2 (Nrf2), transcription factor abolished the EM-induced protection. Inhibition of heme oxygenase-1 (HO-1) also blocked the EM-induced mitochondrial protection. Therefore, EM protected the mitochondria by a mechanism dependent on the AMPK/Nrf2/HO-1 signaling pathway in MG-challenged SH-SY5Y cells.

Cathepsin Inhibition Modulates Metabolism and Polarization of Tumor-Associated Macrophages.

Simple SummaryStroma-infiltrating tumor-associated macrophages (TAM) play an important role in regulating tumor progression and chemoresistance. Many tumor-infiltrating macrophage populations can be identified by preferential expression of distinct marker genes associated with an M2 phenotype and may execute tumor-promoting functions by enhancing tissue remodeling, facilitating angiogenesis, and suppressing immune responses. In this study, we aimed to characterize the impact of cathepsins in maintaining the TAM phenotype. For this purpose, we investigated the molecular effects of cathepsin inhibition on the viability and polarization of human primary macrophages as well as its metabolic consequences. Pharmacological inhibition of cathepsins B, L, and S using a novel inhibitor, GB111-NH2, led to a polarization shift from M2- to M1 macrophages, associated with distinct alterations in lysosomal signaling and lipid metabolism. This could be therapeutically exploited in tumors with strong infiltration of M2-macrophages, thereby possibly reverting M2 polarization, overcoming drug resistance, and improving the prognosis of our patients.Stroma-infiltrating immune cells, such as tumor-associated macrophages (TAM), play an important role in regulating tumor progression and chemoresistance. These effects are mostly conveyed by secreted mediators, among them several cathepsin proteases. In addition, increasing evidence suggests that stroma-infiltrating immune cells are able to induce profound metabolic changes within the tumor microenvironment. In this study, we aimed to characterize the impact of cathepsins in maintaining the TAM phenotype in more detail. For this purpose, we investigated the molecular effects of pharmacological cathepsin inhibition on the viability and polarization of human primary macrophages as well as its metabolic consequences. Pharmacological inhibition of cathepsins B, L, and S using a novel inhibitor, GB111-NH2, led to changes in cellular recycling processes characterized by an increased expression of autophagy- and lysosome-associated marker genes and reduced adenosine triphosphate (ATP) content. Decreased cathepsin activity in primary macrophages further led to distinct changes in fatty acid metabolites associated with increased expression of key modulators of fatty acid metabolism, such as fatty acid synthase (FASN) and acid ceramidase (ASAH1). The altered fatty acid profile was associated with an increased synthesis of the pro-inflammatory prostaglandin PGE2, which correlated with the upregulation of numerous NFkB-dependent pro-inflammatory mediators, including interleukin-1 (IL-1), interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), and tumor necrosis factor-alpha (TNFα). Our data indicate a novel link between cathepsin activity and metabolic reprogramming in macrophages, demonstrated by a profound impact on autophagy and fatty acid metabolism, which facilitates a pro-inflammatory micromilieu generally associated with enhanced tumor elimination. These results provide a strong rationale for therapeutic cathepsin inhibition to overcome the tumor-promoting effects of the immune-evasive tumor micromilieu.

The sequence characteristics and functions on regulating trehalose metabolism of two PTP genes in Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Protein tyrosine phosphatase is a type of enzyme commonly found in eukaryotes that specifically hydrolyzes tyrosine phosphate bonds on protein substrates to remove phosphate, thereby regulating protein functions or even cell functions. In this study, we used the model insect Tribolium castaneum to study the sequence characteristics and functions on trehalose metabolism of two PTP proteins in T. castaneum. We found that TcPTP1X1 and TcPTPIVA1 contain 190 and 177 amino acids, respectively. The results of phylogenetic analysis showed that PTP1 and PTPIVA1 are less well conserved across insect lineages. Examining the tissue and developmental expression patterns revealed that TcPTP1X1 and TcPTPIVA1 are expressed in various tissues and stages of T. castaneum; they are highly expressed in the tarsus during the pupal and adult stages. Compared with the negative control dsGFP group, almost all trehalase and 6-trehalose phosphate synthase genes were significantly down-regulated at 48 h after injection with dsPTP1X1 or dsPTPIVA1, except TRE1-3. At 72 h, many of the TRE and TPS genes appeared to return to normal levels or were even significantly upregulated compared with the control group. Silencing of TcPTP1X1 or TcPTPIVA1 altered the distribution of trehalose, glucose and glycogen in T. castaneum. Moreover, suppression of TcPTP1X1 or TcPTPIVA1 expression resulted in reduced adenosine triphosphate (ATP) content. We suggest that knockdown of TcPTP1X1 or TcPTPIVA1 impairs trehalose and energy metabolism in T. castaneum, and they may be new targets for control of storage pests.

Resistance to Bipyridyls Mediated by the TtgABC Efflux System in Pseudomonas putida KT2440.

Resistance-nodulation-division (RND) transporters are involved in antibiotic resistance and have a broad substrate specificity. However, the physiological significance of these efflux pumps is not fully understood. Here, we have investigated the role of the RND system TtgABC in resistance to metal ion chelators in the soil bacterium Pseudomonas putida KT2440. We observed that the combined action of an RND inhibitor and the chelator 2,2'-bipyridyl inhibited bacterial growth. In addition, the deletion of ttgB made the strain susceptible to 2,2'-bipyridyl and natural bipyridyl derivatives such as caerulomycin A, indicating that TtgABC is required for detoxification of compounds of the bipyridyl family. Searching for the basis of growth inhibition by bipyridyls, we found reduced adenosine triphosphate (ATP) levels in the ttgB mutant compared to the wild type. Furthermore, the expression of genes related to iron acquisition and the synthesis of the siderophore pyoverdine were reduced in the mutant compared to the wild type. Investigating the possibility that 2,2'-bipyridyl in the ttgB mutant mediates iron accumulation in cells (which would cause the upregulation of genes involved in oxidative stress via the Fenton reaction), we measured the expression of genes coding for proteins involved in intracellular iron storage and the response to oxidative stress. However, none of the genes was significantly upregulated. In a further search for a possible link between 2,2'-bipyridyl and the observed phenotypes, we considered the possibility that the ion chelator limits the intracellular availability of metabolically important metal ions. In this context, we found that the addition of copper restores the growth of the ttgB mutant and the production of pyoverdine, suggesting a relationship between copper availability and iron acquisition. Taken together, the results suggest that detoxification of metal chelating compounds of the bipyridyl family produced by other bacteria or higher ordered organisms is one of the native functions of the RND efflux pump TtgABC. Without the efflux pump, these compounds may interfere with cell ion homeostasis with adverse effects on cell metabolism, including siderophore production. Finally, our results suggest that TtgABC is involved in resistance to bile salts and deoxycholate.

Polydatin alleviates parkinsonism in MPTP-model mice by enhancing glycolysis in dopaminergic neurons

Parkinson's disease (PD) is a common neurodegenerative disease. Damage to energy metabolism and reduced adenosine triphosphate (ATP) levels in dopaminergic neurons are common features of PD. Previous studies suggested that the occurrence of PD often affects glucose metabolism and ATP production in the brain, and increased glycolysis or ATP production protects dopaminergic neuronal degeneration in the brain of PD patients. These systems may provide new potential therapeutic targets for the prevention of PD. The present study investigated the inhibitory action of polydatin (PLD) on early dopaminergic neuronal degeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The results showed that PLD protected against MPTP-induced early dopaminergic neuronal degeneration. PLD reduced the MPTP-induced loss of dopaminergic neurons in substantia nigra and striatum, inhibited the occurrence of neural apoptosis, and restored motor function in mice. PLD also increased the continuous activity duration and rhythm amplitude in mice during the circadian activity test. PLD improved glucose metabolism in the brain and restored ATP production levels. These observations suggest that PLD attenuates MPTP-induced early PD-like symptoms, and its mechanism of action may be associated with the promotion of glucose metabolism in neurons.

Electroacupuncture pretreatment alleviates myocardial injury through regulating mitochondrial function

BackgroundElectroacupuncture is well known for its advantageous neuroanalgesic and therapeutic effects on myocardial ischemia–reperfusion injury. The purpose of the present research was to verify whether electroacupuncture can alleviate bupivacaine-induced myocardial injury.MethodsSpecific pathogen-free Wistar rats were used to establish the bupivacaine-induced myocardial injury model. Western blot, PCR, transmission electron microscope and enzyme-linked immunosorbent (ELISA) methods were used to evaluate bupivacaine-induced structure injury and dysfunction of the mitochondria as well as the alleviating effects of lipid emulsion, acupoint injection, and electroacupuncture pre-treatment of the oxidase stress response.ResultsBupivacaine caused structural damage, degradation, and swelling of mitochondria. Furthermore, it reduced adenosine triphosphate (ATP) synthesis and impaired energy metabolism in the mitochondria. Structural and functional impairment of the mitochondria was alleviated via lipid emulsion injection, acupoint injection, and electroacupuncture pre-treatment. Electroacupuncture pre-treatment of PC6 yielded a greater alleviating effect than others approaches. Following electroacupuncture pre-treatment of PC6 point, the number of mitochondria increased; apoptosis was reduced, enzymatic activity of cytochrome C oxidase (COX) and superoxide dismutase and expression of uncoupling protein 2, voltage-dependent anion channel 1, and Bcl 2 were upregulated and SLC25A6, MDA levels were downregulated. Additionally, our findings indicated that electroacupuncture pre-treatment of PC6 point exerted an effect on the mitochondria via the mitochondrial-transcription-factor-A/nuclear-respiratory-factor-1/proliferator-activated-receptor-gamma-coactivator-1 pathway.ConclusionThe present study revealed that electroacupuncture pre-treatment of PC6 could effectively alleviate bupivacaine-induced myocardial mitochondrial damage, thereby providing a theoretical basis for clinical studies and applications of this treatment method.

Energy Shortage in Human and Mouse Models of SLC4A11-Associated Corneal Endothelial Dystrophies.

PurposeTo elucidate the molecular events in solute carrier family 4 member 11 (SLC4A11)-deficient corneal endothelium that lead to the endothelial dysfunction that characterizes the dystrophies associated with SLC4A11 mutations, congenital hereditary endothelial dystrophy (CHED) and Fuchs endothelial corneal dystrophy 4.MethodsComparative transcriptomic analysis (CTA) was performed in primary human corneal endothelial cells (pHCEnC) and murine corneal endothelial cells (MCEnC) with normal and reduced levels of SLC4A11 (SLC4A11 KD pHCEnC) and Slc4a11 (Slc4a11−/− MCEnC), respectively. Validation of differentially expressed genes was performed using immunofluorescence staining of CHED corneal endothelium, as well as western blot and quantitative PCR analysis of SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC. Functional analyses were performed to investigate potential functional changes associated with the observed transcriptomic alterations.ResultsCTA revealed inhibition of cell metabolism and ion transport function as well as mitochondrial dysfunction, leading to reduced adenosine triphosphate (ATP) production, in SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC. Co-localization of SNARE protein STX17 with mitochondria marker COX4 was observed in CHED corneal endothelium, as was activation of AMPK–p53/ULK1 in both SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC, providing additional evidence of mitochondrial dysfunction and mitophagy. Reduced Na+-dependent HCO3− transport activity and altered NH4Cl-induced membrane potential changes were observed in Slc4a11−/− MCEnC.ConclusionsReduced steady-state ATP levels and subsequent activation of the AMPK–p53 pathway provide a link between the metabolic functional deficit and transcriptome alterations, as well as evidence of insufficient ATP to maintain the Na+/K+-ATPase corneal endothelial pump as the cause of the edema that characterizes SLC4A11-associated corneal endothelial dystrophies.

INVOLVEMENT OF PURINERGIC SIGNALING AND LYMPHOID ORGANS IN THE BENEFICIAL EFFECTS OF AEROBIC TRAINING IN ASTHMA

PURPOSE: Asthma is a chronic airway inflammatory disease affecting more than 300 million people around the world. Purinergic signaling via purinergic receptors (mainly P2X7, P2Y2 and P2Y6) are thought play a key role in asthma pathogenesis and severity. High intensity aerobic exercise is known to trigger asthma attacks, while low to moderate intensity training reduces inflammation and improves asthma control. Therefore, this study investigated whether low intensity aerobic exercise reduces asthma phenotype by modulation of purinergic signaling. METHODS: Aerobic exercise (AE) was performed in a treadmill at low intensity, 5x/week, 1h/session, for 4 weeks, beginning 2 weeks after HDM administration. HDM (dermatophagoides pteronyssinus; 100mg/mouse) was administered 3x/week, for 6 weeks. RESULTS: The results demonstrated that AE reduced adenosine triphosphate (ATP) accumulation (p<0.001), IL-1beta, IL-4, IL-5, CXCL1/KC, IL-13, IL-17, IL-23, IL-33 and TNF-alpha (p<0.001), while increased IL-1ra, IL-2, IL-10 and IL-12p40 in bronchoalveolar lavage (BAL). Total number of leukocytes, eosinophils, lymphocytes and neutrophils in BAL and the number of eosinophils, neutrophils and lymphocytes in the airway wall (p<0.01) were reduced by AE. Airway remodeling (collagen, elastin, smooth muscle and mucus) were reduced by AE (p<0.01). TGF-beta, IGF-1 and VEGF levels was reduced by AE (p<0.001). Lung mechanics (Resistance, Elastance, GTIS, HTIS, RAW) and airway hyperresponsiveness (AHR) to methacholine was ameliorated by AE (p<0.01). IL-4, IL-5 and IL-13 production by re-stimulated mediastinal lymph nodes, splenocytes and bone marrow cells was also reduced by AE. The expression of P2X7, P2Y2 and P2Y6 by peribronchial leukocytes (p<0.01) and also by airway epithelial cells (p<0.01) were reduced by AE. CONCLUSIONS: Low intensity aerobic training reduces asthma phenotype by inhibiting purinergic signaling and lymphoid organs hyperactivation.

Optically Improved Mitochondrial Function Redeems Aged Human Visual Decline.

The age spectrum of human populations is shifting toward the older with larger proportions suffering physical decline. Mitochondria influence the pace of aging as the energy they provide for cellular function in the form of adenosine triphosphate (ATP) declines with age. Mitochondrial density is greatest in photoreceptors, particularly cones that have high energy demands and mediate color vision. Hence, the retina ages faster than other organs, with a 70% ATP reduction over life and a significant decline in photoreceptor function. Mitochondria have specific light absorbance characteristics influencing their performance. Longer wavelengths spanning 650->1,000 nm improve mitochondrial complex activity, membrane potential, and ATP production. Here, we use 670-nm light to improve photoreceptor performance and measure this psychophysically in those aged 28-72 years. Rod and cone performance declined significantly after approximately 40 years of age. 670-nm light had no impact in younger individuals, but in those around 40 years and older, significant improvements were obtained in color contrast sensitivity for the blue visual axis (tritan) known to display mitochondrial vulnerability. The red visual axis (protan) improved but not significantly. Rod thresholds also improved significantly in those >40 years. Using specific wavelengths to enhance mitochondrial performance will be significant in moderating the aging process in this metabolically demanding tissue.

Electroacupuncture preconditioning attenuates myocardial ischemia-reperfusion injury by inhibiting mitophagy mediated by the mTORC1-ULK1-FUNDC1 pathway

Myocardial ischemia/reperfusion (I/R) is an important complication of reperfusion therapy for myocardial infarction, and trimetazidine is used successfully for treatment of ischemic cardiomyopathy by regulating mitochondrial function. Moreover, electroacupuncture (EA) preconditioning was demonstrated to be cardioprotective in both in vivo rodent models and in patients undergoing heart valve replacement surgery. However, the mechanisms have not been well elucidated. Mitophagy, mediated by the mTORC1-ULK1-FUNDC1 (mTOR complex 1-unc-51-like autophagy-activating kinase 1-FUN14 domain-containing 1) pathway, can regulate mitochondrial mass and cell survival effectively to restrain the development of myocardial ischemia/reperfusion injury (MIRI). In this study, we hypothesized that EA preconditioning ameliorated MIRI via mitophagy. To test this, rapamycin, an mTOR inhibitor, was used. The results showed that EA preconditioning could reduce the infarct size and risk size, and decrease the ventricular arrhythmia score and serum creatine kinase-myocardial band isoenzyme (CK-MB), lactate dehydrogenase (LDH), and cardiac troponin T (cTnT) in MIRI rats. Moreover, it also attenuated MIRI-induced apoptosis and mitophagy accompanied by elevated mTORC1 level and decreased ULK1 and FUNDC1 levels. However, these effects of EA preconditioning were blocked by rapamycin, which aggravated MIRI, reduced adenosine triphosphate (ATP) production, and antagonized infarct size reduction. In conclusion, our results indicated that EA preconditioning protected the myocardium against I/R injury by inhibiting mitophagy mediated by the mTORC1-ULK1-FUNDC1 pathway.

Potent Anticancer Effect of the Natural Steroidal Saponin Gracillin Is Produced by Inhibiting Glycolysis and Oxidative Phosphorylation-Mediated Bioenergetics.

Metabolic rewiring to utilize aerobic glycolysis is a hallmark of cancer. However, recent findings suggest the role of mitochondria in energy generation in cancer cells and the metabolic switch to oxidative phosphorylation (OXPHOS) in response to the blockade of glycolysis. We previously demonstrated that the antitumor effect of gracillin occurs through the inhibition of mitochondrial complex II-mediated energy production. Here, we investigated the potential of gracillin as an anticancer agent targeting both glycolysis and OXPHOS in breast and lung cancer cells. Along with the reduction in adenosine triphosphate (ATP) production, gracillin markedly suppresses the production of several glycolysis-associated metabolites. A docking analysis and enzyme assay suggested phosphoglycerate kinase 1 (PGK1) is a potential target for the antiglycolytic effect of gracillin. Gracillin reduced the viability and colony formation ability of breast cancer cells by inducing apoptosis. Gracillin displayed efficacious antitumor effects in mice bearing breast cancer cell line or breast cancer patient-derived tumor xenografts with no overt changes in body weight. An analysis of publicly available datasets further suggested that PGK1 expression is associated with metastasis status and poor prognosis in patients with breast cancer. These results suggest that gracillin is a natural anticancer agent that inhibits both glycolysis and mitochondria-mediated bioenergetics.

Endogenous ethanol produced by intestinal bacteria induces mitochondrial dysfunction in non-alcoholic fatty liver disease.

A causal relationship between changes of the gut microbiome and non-alcoholic fatty liver disease (NAFLD) remains unclear. We demonstrated that endogenous ethanol (EnEth) produced by intestinal microbiota is likely a causative agent of NAFLD. Two mutants with different alcohol-producing abilities, namely, W14-adh and W14Δadh, were constructed using the clinical high alcohol-producing (HiAlc) Klebsiella pneumoniae strain W14 as a parent. Damage to hepatocytes caused by bacteria with different alcohol-producing capacities was evaluated (EtOH group as positive control). The ultrastructural changes of mitochondria were assessed via transmission electron microscopy (TEM). Hepatic levels of mitochondrial reactive oxygen species (ROS), DNA damage, and adenosine triphosphate were examined. The results illustrated that steatosis was most severe in the W14-adh group, followed by the W14 group, whereas the W14Δadh group had few fatty droplets. TEM and examination of related protein expression revealed that the mitochondrial integrity of HepG2 hepatocytes was considerably damaged in the EtOH and bacteria treatment groups. The impaired mitochondrial function in HepG2 hepatocytes was evidenced by reduced adenosine triphosphate content and increased mitochondrial ROS accumulation and DNA damage in the EtOH and bacteria treatment groups, especially the W14-adh group. Meanwhile, liver injury and mitochondrial damage were observed in the hepatocytes of mice. The livers of mice in the W14-adh group, which had the highest ethanol production, exhibited the most serious damage, similar to that in the EtOH group. EnEth produced by HiAlc bacteria induces mitochondrial dysfunction in NAFLD.

Brain function and metabolism in patients with long-term tacrolimus therapy after kidney transplantation in comparison to patients after liver transplantation

About 50% of the patients 5-7 years after kidney transplantation show impairment of memory, attention and executive function. Tacrolimus frequently induces neurological complications in the first few weeks after transplantation. Furthermore, tacrolimus treatment is associated with impaired cognitive function in the long-term in patients after liver transplantation. We hypothesize that long-term tacrolimus therapy is associated with cognitive dysfunction and alterations of brain structure and metabolism in patients after kidney transplantation. Twenty-one patients 10 years after kidney transplantation underwent cognitive testing, magnetic resonance imaging and whole brain 31-phosphor magnetic resonance spectroscopy for the assessment of brain function, structure and energy metabolism. Using a cross-sectional study design the results were compared to those of patients 1 (n = 11) and 5 years (n = 10) after kidney transplantation, and healthy controls (n = 17). To further analyze the share of transplantation, tacrolimus therapy and kidney dysfunction on the results patients after liver transplantation (n = 9) were selected as a patient control group. Patients 1 and 10 years after kidney transplantation (p = 0.02) similar to patients 10 years after liver transplantation (p<0.01) showed significantly worse cognitive function than healthy controls. In contrast to patients after liver transplantation patients after kidney transplantation showed significantly reduced adenosine triphosphate levels in the brain compared to healthy controls (p≤0.01). Patients 1 and 5 years after kidney transplantation had significantly increased periventricular hyperintensities compared to healthy controls (p<0.05). Our data indicate that cognitive impairment in the long-term after liver and kidney transplantation cannot exclusively be explained by CNI neurotoxicity.

Defective arginine metabolism impairs mitochondrial homeostasis in Caenorhabditiselegans

Arginine catabolism involves enzyme-dependent reactions in both mitochondria and the cytosol, defects in which may lead to hyperargininemia, a devastating developmental disorder. It is largely unknown if defective arginine catabolism has any effects on mitochondria. Here we report that normal arginine catabolism is essential for mitochondrial homeostasis in Caenorhabditiselegans. Mutations of the arginase gene argn-1 lead to abnormal mitochondrial enlargement and reduced adenosine triphosphate (ATP) production in C. elegans hypodermal cells. ARGN-1 localizes to mitochondria and its loss causes arginine accumulation, which disrupts mitochondrial dynamics. Heterologous expression of human ARG1 or ARG2 rescued the mitochondrial defects of argn-1 mutants. Importantly, genetic inactivation of the mitochondrial basic amino acid transporter SLC-25A29 or the mitochondrial glutamate transporter SLC-25A18.1 fully suppressed the mitochondrial defects caused by argn-1 mutations. These findings suggest that mitochondrial damage probably contributes to the pathogenesis of hyperargininemia and provide clues for developing therapeutic treatments for hyperargininemia.

AKAP1 mediates high glucose-induced mitochondrial fission through the phosphorylation of Drp1 in podocytes.

Increasing evidence suggests that mitochondrial dysfunction plays a critical role in the development of diabetic kidney disease (DKD), however, its specific pathomechanism remains unclear. A-kinase anchoring protein (AKAP) 1 is a scaffold protein in the AKAP family that is involved in mitochondrial fission and fusion. Here, we show that rats with streptozotocin (STZ)-induced diabetes developed podocyte damage accompanied by AKAP1 overexpression and that AKAP1 closely interacted with the mitochondrial fission enzyme dynamin-related protein 1 (Drp1). At the molecular level, high glucose (HG) promoted podocyte injury and Drp1 phosphorylation at Ser637 as proven by decreased mitochondrial membrane potential, elevated reactive oxygen species generation, reduced adenosine triphosphate synthesis, and increased podocyte apoptosis. Furthermore, the AKAP1 knockdown protected HG-induced podocyte injury and suppressed HG-induced Drp1 phosphorylation at Ser637. AKAP1 overexpression aggravated HG-induced mitochondrial fragmentation and podocyte apoptosis. The coimmunoprecipitation assay showed that HG-induced Drp1 interacted with AKAP1, revealing that AKAP1 could recruit Drp1 from the cytoplasm under HG stimulation. Subsequently, we detected the effect of drp1 phosphorylation on Ser637 by transferring several different Drp1 mutants. We demonstrated that activated AKAP1 promoted Drp1 phosphorylation at Ser637, which promoted the transposition of Drp1 to the surface of the mitochondria and accounts for mitochondrial dysfunction events. These findings indicate that AKAP1 is the main pathogenic factor in the development and progression of HG-induced podocyte injury through the destruction of mitochondrial dynamic homeostasis by regulating Drp1 phosphorylation in human podocytes.