Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virus-infected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105 PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.
PURPOSE: The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for diagnosing central precocious puberty (CPP). Gonadorelin (Relefact) is used for the test but is not always readily available; triptorelin is used as an alternative. The purpose of this study was to evaluate the diagnostic validity of the triptorelin test compared with the GnRH test in the diagnosis of CPP in girls. METHODS: This retrospective study included 100 girls with premature thelarche (PT) who underwent a hypothalamic-pituitary-gonadal axis evaluation. In the overall group, 50 girls were tested with intravenous gonadorelin (Relefact) and 50 girls were tested with subcutaneous triptorelin acetate (Decapeptyl). Luteinizing hormone (LH) and follicle-stimulating hormone levels were measured at baseline and 30, 45, 60, and 90 minutes after gonadorelin injection or 30, 60, 90, and 120 minutes after triptorelin injection. RESULTS: Clinical characteristics of age, height, weight, body mass index, and bone age were similar between the 2 groups. The highest LH level was reached 60 minutes after stimulation in both groups. Approximately 20% of the gonadorelin group and 24% of the triptorelin group were diagnosed with CPP (P=0.52). Among those diagnosed with CPP, the mean peak LH concentrations were 8.15 mIU/mL and 9.73 mIU/mL in the gonadorelin and triptorelin groups, respectively. CONCLUSION: The triptorelin test showed similar trends of LH elevation and diagnostic rate compared with the traditional GnRH test for diagnosing CPP. This suggests that the triptorelin test may be a valid alternative to the GnRH test for differentiating CPP from self-limiting PT. Our study also demonstrated that a triptorelin stimulation test for up to 120 minutes was sufficient to diagnose CPP.
Zn ion batteries (ZIBs) are a promising candidate in safe and low-cost large-scale energy storage applications. However, significantly deteriorated cycling stability of Zn anode in high depth of charge or after long-term quiescence impedes the practical application of ZIBs. Aiming at the above issue, a spontaneous solid electrolyte interphase (SEI) formation of Zn4(OH)6SO4·xH2O (ZHS) on Zn powder is achieved in pure ZnSO4 electrolyte by facile and rational interface design. The stable and ultrathin ZHS SEI plays a crucial part in insulating water molecules and conducting Zn2+ ions, intrinsically suppressing the severe hydrogen evolution and dendrite formation on the Zn powder anode. The ZHS-Zn anode delivers a stable cycling at a high DOD of 50% for over 500 h, as well as a lifespan of over 200 h after 40-days of resting at a DOD of 25%. Benefiting from the high utilization of Zn anode, the energy density of the Zn-MnxV2O5 full cell is up to 118 Wh Kg-1. This facile method can fabricate the ZHS-Zn anode as long as 1 m, revealing its feasibility in large-scale production and commercialization.
Polymethylmethacrylate (PMMA) has been used in many products, such as acrylic glass, and is estimated to reach 5.7 million tons of production per year by 2028. Thus, nano-sized PMMA particles in the environment are highly likely due to the weathering process. However, information on the hazards of nanoplastics, including PMMA in mammals, especially reproductive toxicity and action mechanism, is scarce. Herein, we investigated the effect of PMMA nanoplastics on the female reproductive system of mice embryos during pre-implantation. The treated plastic particles in embryos (10, 100, and 1000 µg/mL) were endocytosed into the cytoplasm within 30 min, and the blastocyst development and indices of embryo quality were significantly decreased from at 100 µg/mL. Likewise, the transfer of nanoplastic-treated embryos at 100 µg/mL decreased the morula implantation rate on the oviduct of pseudopregnant mice by 70%, calculated by the pregnant individual, and 31.8% by the number of implanted embryos. The PMMA nanoplastics at 100 µg/mL significantly increased the cellular levels of reactive oxygen species in embryos, which was not related to the intrinsic oxidative potential of nanoplastics. This study highlights that the nanoplastics that enter systemic circulation can affect the early stage of embryos. Thus, suitable action mechanisms can be designed to address nanoplastic occurrence.
Background: This study aimed to investigate whether placebo control is differently disclosed in drug and non-drug randomised clinical trial (RCT) participant information leaflets (PILs) and how this might affect participant blinding and direction of study outcomes. Methods: PILs were obtained from trials registered in the International Standard Randomised Controlled Trial Number database via email. Placebo descriptions in PILs were categorised as Full Disclosure (FD), Partial Disclosure (PD), or Missing Information (MI). Associations between intervention type (drug or non-drug)/placebo disclosure (FD or PD/MI) and participant blinding success/trial outcome direction (positive or non-positive) were examined using a two-sided Fisher's exact test. Results: Of 116 collected PILs, 56 % were for drug trials and 44 % were for non-drug trials. Among them, 88 PILs had the corresponding publications available and 68 reports specified primary outcomes. Drug trials were more likely to fully disclose placebo information than non-drug trials (92.3 % vs. 74.5 %, p < 0.05). However, the success rate of blinding was only reported in 3 out of 88 trial publications (3.4 %), precluding further analysis. Furthermore, there was no significant association between the direction of trial results and the type of intervention or placebo disclosure. Conclusion: Our study findings suggest that drug and non-drug RCTs might differ in the way they reveal placebo control information. Further research is warranted to understand what leads to more common PD of placebo information in non-drug trials than drug trials and to determine the optimal placebo control disclosure in specific trial context.
PURPOSE: Diabetes mellitus (DM) is a global health concern linked to various complications, including cardiovascular disease (CVD). However, long-term follow-up studies on the risk of DM and CVD using different blood glucose assessment methods in the general Korean population are lacking. This study aimed to assess the predictive abilities of fasting plasma glucose (FPG), 2-h oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c) for new-onset DM and high CVD risk in a middle-aged and older Korean population. METHODS: This study used data from the Korean Genome and Epidemiology Study, a population-based prospective cohort. Blood sugar measures (FPG, OGTT, and HbA1c) were examined. The primary endpoint was the development of new-onset DM, and CVD risk was evaluated using the Framingham risk score. The predictive abilities for new-onset DM based on glycemic values were evaluated using Harrell's Concordance index and 95% confidence intervals. RESULTS: Among the 10,030 participants, data of 6813 participants without DM at baseline were analyzed. The study revealed that OGTT outperformed FPG and HbA1c in predicting new-onset DM. The combination of FPG and HbA1c did not significantly enhance predictions for DM compared with OGTT alone. OGTT also outperformed FPG and HbA1c in predicting high CVD risk, and this difference remained significant even after adjusting for additional confounders. CONCLUSION: OGTT has superior predictive capabilities in identifying new-onset DM and high CVD risk in the Korean population. This suggests that relying solely on individual blood sugar measures may be insufficient for assessing DM and CVD risks.
BACKGROUNDS & AIMS: Menopause, characterized by a sudden decline in estrogen levels, has significant effects on women's health, especially when it occurs early. This study aimed to investigate the associations between menopausal age and incidence of metabolic dysfunction-associated fatty liver disease (MAFLD) using a large cohort and a long-term follow-up. METHODS: Menopausal age was categorized into four groups (G1-4 [<40, 40-44, 45-49, and ≥50 years, respectively]). Cox proportional hazards regression analysis was used to assess the risk of developing MAFLD during the follow-up period according to the menopausal age categories. RESULTS: A total of 1,888 participants were included in the final analysis and followed for a median period of 12.3 years. The unadjusted hazard ratios (95 % CIs) for the incidence of new-onset MAFLD were 1.11 (0.93-1.32), 1.15 (0.90-1.47), and 1.52 (1.12-2.07) in G3, G2, and G1, respectively, compared with that in G4. After adjusting for confounders, the hazard ratio (95 % CIs) for the incidence of new-onset MAFLD was 1.40 (1.00-1.95) in G1 compared with that in G4. CONCLUSION: The risk of developing MAFLD was higher in women with premature menopause (<40 years) than in those with menopause aged ≥50 years.
High-performance fluorescent probes stand as indispensable tools in fluorescence-guided imaging, and are crucial for precise delineation of focal tissue while minimizing unnecessary removal of healthy tissue. Herein, we firstly proposed machine learning-assisted strategy to investigate the current available xanthene dyes, and constructed a quantitative prediction model to guide the rational synthesis of novel fluorescent molecules with desired pH responsivity. We successfully achieved two novel Si-rhodamine derivatives and constructed the Cathepsin/pH sequentially activated probe SiR-CTS-pH. The results reveal that SiR-CTS-pH exhibits higher signal-to-noise ratio of fluorescence imaging, compared to single pH or cathepsin-activate probe. Moreover, SiR-CTS-pH shows strong differentiation abilities for tumor cells and tissues and accurately discriminates the complex hepatocellular carcinoma tissues from normal ones, indicating its significant application potential in clinical practice. Therefore, the continuous development of xanthene dyes and the rational design of superior fluorescent molecules through Machine Learning-assisted model will broaden the path and provide more advanced methods to researchers. This article is protected by copyright. All rights reserved.
BACKGROUND: Detection methods based on aptamer probes have great potential and progress in the field of rapid detection of heavy metal ions. However, the unstable conformation of aptamers often results in poor sensitivity due to the dissociation of aptamer-target complex in real environments. RESULTS: In this study, we developed a locking aptamer probe and combined it with AgInZnS quantum dots for the first time to detect cadmium ions. When cadmium ions are combined with the probe, the cadmium ions are fixed in the core-locking position, forming a stable cavity structure. The limit of detection (LOD) was achieved at a concentration of 6.9 nmol L-1, with a broad detection range from 10 nmol L-1 to 1000 µmol L-1, and good recovery rates (92.93%-102.8 %) were achieved in aquatic product testing. The locking aptamer probe with stable conformation effectively enhances the stability of the aptamer-target complex and remains good stability in four buffer environments as well as a 600 mmol L-1 salt solution; it also exhibits good stability at pH 6.5-7.5 and temperatures ranging from 25 °C to 35 °C. SIGNIFICANCE: Overall, our study presented a general, simple, and cost-effective strategy for stabilizing aptamer conformations, and used for highly sensitive detection of cadmium ions.
Stutzerimonas stutzeri strain FeN3W is an iron-oxidizing bacterium isolated from marine sediment. FeN3W's 5.9 Mb genome encodes complete pathways for glycolysis, gluconeogenesis, TCA cycle, pentose phosphate pathway, and aerobic and anaerobic (nitrate) respiration. The genome contains 32 putative heme-binding proteins predicted to localize to the cell envelope.
Stereoselective construction of γ- and δ-stereocenters in carbonyl compounds is a pivotal objective in asymmetric synthesis. Here, we report chiral bifunctional oxazoline-pyridone ligands that enable enantioselective palladium-catalyzed remote γ-C-H (hetero)arylations of free cycloalkane carboxylic acids, which are essential carbocyclic building blocks in organic synthesis. The reaction establishes γ-tertiary and α-quaternary stereocenters simultaneously in up to >99% enantiomeric excess, providing access to a wide range of cyclic chiral synthons and bioactive molecules. The sequential enantioselective editing of two methylene C-H bonds can be achieved by using chiral ligands with opposite configuration to construct carbocycles containing three chiral centers. Enantioselective remote δ-C-H (hetero)arylation is also realized to establish δ-stereocenters that are particularly challenging to access using classical methodologies.
BACKGROUND: A wide array of histone deacetylase (HDAC) inhibitors and aryl hydrocarbon receptor (AHR) agonists commonly arrest experimental autoimmune encephalomyelitis (EAE). However, it is not known whether HDAC inhibition is linked to the AHR signaling pathway in EAE. METHODS: We investigated how the pan-HDAC inhibitor SB939 (pracinostat) exerted immunoregulatory action in the myelin oligodendrocyte glycoprotein 35-55 (MOG35-55)-induced EAE mouse model by evaluating changes in of signal transducer and activator of transcription 3 (STAT3) acetylation and the expression of indoleamine 2,3-dioxygenase 1 (IDO1) and AHR in inflamed spinal cords during EAE evolution. We proved the involvement of IDO1 and the AHR in SB939-mediated immunosuppression using Ido1-/- and Ahr-/- mice. RESULTS: Administration with SB939 halted EAE progression, which depended upon IDO1 expression in neurons of the central nervous system (CNS). Our in vitro and in vivo studies demonstrated that SB939 sustained the interleukin-6-induced acetylation of STAT3, resulting in the stable transcriptional activation of Ido1. The therapeutic effect of SB939 also required the AHR, which is expressed mainly in CD4+ T cells and macrophages in CNS disease lesions. Finally, SB939 was shown to markedly reduce the proliferation of CD4+ T cells in inflamed neuronal tissues but not in the spleen or draining lymph nodes. CONCLUSIONS: Overall, our results suggest that IDO1 tryptophan metabolites produced by neuronal cells may act on AHR in pathogenic CD4+ T cells in a paracrine fashion in the CNS and that the specific induction of IDO1 expression in neurons at disease-afflicted sites can be considered a therapeutic approach to block the progression of multiple sclerosis without affecting systemic immunity.
This study aimed to assess the current status of gestational diabetes mellitus (GDM) diagnosis and management, and the demand for a digital healthcare system, in order to develop an optimal digital-based management model for GDM. An anonymous online survey was conducted targeting pregnant/postpartum women (Group W), internal medicine physicians (Group P), and obstetricians (group O) from September 6, 2022 to December 31, 2022. The survey assessed the women's knowledge of GDM and gathered information about healthcare professionals' (HCPs) current GDM management practices. All groups were asked about their acceptance of and demands for a digital healthcare system for GDM. Statistical comparisons between groups were conducted using the chi-square test or Fisher's exact test where appropriate. A total of 168 participants were in Group W, 185 in Group P, and 256 in Group O. Participants from all groups recognized the need for a digital healthcare system for GDM (Group W: 95.8%, Group P: 85.9%, Group O: 60%). However, HCPs showed less willingness to integrate these systems into their clinics than pregnant/postpartum women. Essential features identified were recording blood glucose levels and insulin, along with automatic data linkage from self-monitoring devices. Group W showed a higher preference for lab test access, search functionality, and fetal weight assessment than groups P and O (all P < .0001), while Groups P and O had a greater preference for recording insulin and maternal body weight compared to Group W (P = .0141 and .0023, respectively). Both pregnant/postpartum women and HCPs acknowledged the benefits of utilizing a digital healthcare system for managing GDM. However, there were differences in perspectives among these groups.
Diabetes, Gestational , Humans , Diabetes, Gestational/therapy , Female , Pregnancy , Cross-Sectional Studies , Adult , Surveys and Questionnaires , Health Personnel , Telemedicine
This paper comprehensively reviews sensors and sensing devices developed or/and proposed so far utilizing two smart materials: electrorheological fluids (ERFs) and magnetorheological materials (MRMs) whose rheological characteristics such as stiffness and damping can be controlled by external stimuli; an electrical voltage for ERFs and a magnetic field for MRMs, respectively. In this review article, the MRMs are classified into magnetorheological fluids (MRF), magnetorheological elastomers (MRE) and magnetorheological plastomers (MRP). To easily understand the history of sensing research using these two smart materials, the order of this review article is organized in a chronological manner of ERF sensors, MRF sensors, MRE sensors and MRP sensors. Among many sensors fabricated from each smart material, one or two sensors or sensing devices are adopted to discuss the sensing configuration, working principle and specifications such as accuracy and sensitivity. Some sensors adopted in this article include force sensors, tactile devices, strain sensors, wearable bending sensors, magnetometers, display devices and flux measurement sensors. After briefly describing what has been reviewed in a conclusion, several challenging future works, which should be undertaken for the practical applications of sensors or/and sensing devices, are discussed in terms of response time and new technologies integrating with artificial intelligence neural networks in which several parameters affecting the sensor signals can be precisely and optimally tuned. It is sure that this review article is very helpful to potential readers who are interested in creative sensors using not only the proposed smart materials but also different types of smart materials such as shape memory alloys and active polymers.
The benefits of minimally invasive approaches in colorectal surgery have been well demonstrated. However, some hesitancy remains with regards to the utilization of the robotic platform for total colectomies, mostly due to the perceived need for multiple re-dockings in multiquadrant surgery. This video aims to demonstrate how the robotic platform can be efficiently utilized in multiquadrant surgery without the need for multiple re-dockings, as well as some tips on how to overcome the potential challenges that may be encountered during this procedure.
PURPOSE: This study aimed to examine the health concerns of parents regarding their premature infants and to identify changes in these concerns during perinatal period and after discharge. METHODS: This was a retrospective study performed at a single tertiary center that enrolled 119 premature infants who were discharged from the neonatal intensive care unit (NICU) and visited the outpatient pediatrics department between December 2018 and October 2021. Data on the concerns of 176 parents regarding enrolled premature infants' health from before birth to 1 week after NICU discharge were obtained from outpatient records. The t test and with the chi-squared test were used to analyze the data for this study. RESULTS: The consistently greatest focus of parents' health concerns was the respiratory system. The second focus of parents' health concerns before discharge was the central nervous system. However, during the first week after NICU discharge, the gastrointestinal system was the second-most frequent focus of parents' health concerns among parents of infants without diseases related to prematurity and infants with older gestational ages. CONCLUSION: The results of this study offer insights into the health concerns among parents of premature infants. Parental health concerns about premature infants vary over time, from before birth to post-discharge, necessitating supportive interventions to enhance parental understanding of their child's health status.
AIM: Biotechnical processes in Escherichia coli often operate with artificial plasmids. However, these bioprocesses frequently encounter plasmid loss. To ensure stable expression of heterologous genes in E. coli BL21(DE3), a novel plasmid addiction system (PAS) was developed. METHODS AND RESULTS: This PAS employed an essential gene grpE encoding a cochaperone in the DnaK-DnaJ-GrpE chaperone system as the selection marker, which represented a chromosomal ΔgrpE mutant harboring episomal expression plasmids that carry supplementary grpE alleles to restore the deficiency. To demonstrate the feasibility of this system, it was implemented in phloroglucinol (PG) biosynthesis, manifesting improved host tolerance to PG and increased PG production. Specifically, PG titer significantly improved from 0.78 ± 0.02 to 1.34 ± 0.04 g l-1, representing a 71.8% increase in shake-flask fermentation. In fed-batch fermentation, the titer increased from 3.71 ± 0.11 to 4.54 ± 0.10 g l-1, showing a 22.4% increase. RNA sequencing and transcriptome analysis revealed that the improvements were attributed to grpE overexpression and upregulation of various protective chaperones and the biotin acetyl-CoA carboxylase ligase coding gene birA. CONCLUSION: This novel PAS could be regarded as a typical example of nonanabolite- and nonmetabolite-related PAS. It effectively promoted plasmid maintenance in the host, improved tolerance to PG, and increased the titer of this compound.
Escherichia coli Proteins , Escherichia coli , Phloroglucinol , Plasmids , Escherichia coli/genetics , Escherichia coli/metabolism , Phloroglucinol/metabolism , Phloroglucinol/analogs & derivatives , Plasmids/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Fermentation , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism
PURPOSE: Large language models continue to dramatically change the medical landscape. We aimed to explore the utility of ChatGPT in providing accurate, actionable, and understandable generative medical translations in English, Spanish, and Mandarin pertaining to Otolaryngology. METHODS: Responses of GPT-4 to commonly asked patient questions listed on official otolaryngology clinical practice guidelines (CPG) were evaluated with the Patient Education materials Assessment Tool-printable (PEMAT-P.) Additional critical elements were identified a priori to evaluate ChatGPT's accuracy and thoroughness in its responses. Multiple fluent speakers of English, Mandarin, and Spanish evaluated each response generated by ChatGPT. RESULTS: Total PEMAT-P scores differed between English, Mandarin, and Spanish GPT-4 generated responses depicting a moderate effect size of language, Eta-Square 0.07 with scores ranging from 73 to 77 (P-value = 0.03). Overall understandability scores did not differ between English, Mandarin, and Spanish depicting a small effect size of language, Eta-Square 0.02 scores ranging from 76 to 79 (P-value = 0.17), nor did overall actionability scores Eta-Square 0 score ranging 66-73 (P-value = 0.44). Overall a priori procedure-specific responses similarly did not differ between English, Spanish, and Mandarin Eta-Square 0.02 scores ranging 61-78 (P-value = 0.22). CONCLUSION: GPT-4 produces accurate, understandable, and actionable outputs in English, Spanish, and Mandarin. Responses generated by GPT-4 in Spanish and Mandarin are comparable to English counterparts indicating a novel use for these models within Otolaryngology, and implications for bridging healthcare access and literacy gaps. LEVEL OF EVIDENCE: IV.
The chemical 4-amino-3-nitrophenol (4A3NP) is classified as an amino nitrophenol and is primarily utilized as an ingredient in hair dye colorants. In Korea and Europe, it is exclusively used in non-oxidative or oxidative hair dye formulations, with maximum allowable concentrations of 1% and 1.5%, respectively. Despite this widespread use, risk assessment of 4A3NP has not been completed due to the lack of proper dermal absorption data. Therefore, in this study, both the analytical method validation and in vitro dermal absorption study of 4A3NP were conducted following the guidelines provided by the Korea Ministry of Food and Drug Safety (MFDS). Before proceeding with the dermal absorption study, analytical methods were developed for the quantitation of 4A3NP through multiple reaction monitoring (MRM) via liquid chromatography-mass spectrometry (LC-MS) in various matrices, including swab wash (WASH), stratum corneum (SC), skin (SKIN, comprising the dermis and epidermis), and receptor fluid (RF). These developed methods demonstrated excellent linearity (R2 = 0.9962-0.9993), accuracy (93.5-111.73%), and precision (1.7-14.46%) in accordance with the validation guidelines.The dermal absorption of 4A3NP was determined using Franz diffusion cells with mini-pig skin as the barrier. Under both non-oxidative and oxidative (6% hydrogen peroxide (H2O2): water, 1:1) hair dye conditions, 1% and 1.5% concentrations of 4A3NP were applied to the skin at a rate of 10 µL/cm2, respectively. The total dermal absorption rates of 4A3NP under non-oxidative (1%) and oxidative (1.5%) conditions were determined to be 5.62 ± 2.19% (5.62 ± 2.19 µg/cm2) and 2.83 ± 1.48% (4.24 ± 2.21 µg/cm2), respectively.
BACKGROUND: Glycolytic flux is regulated by the energy demands of the cell. Upregulated glycolysis in cancer cells may therefore result from increased demand for adenosine triphosphate (ATP), however it is unknown what this extra ATP turnover is used for. We hypothesise that an important contribution to the increased glycolytic flux in cancer cells results from the ATP demand of Na+/K+-ATPase (NKA) due to altered sodium ion homeostasis in cancer cells. METHODS: Live whole-cell measurements of intracellular sodium [Na+]i were performed in three human breast cancer cells (MDA-MB-231, HCC1954, MCF-7), in murine breast cancer cells (4T1), and control human epithelial cells MCF-10A using triple quantum filtered 23Na nuclear magnetic resonance (NMR) spectroscopy. Glycolytic flux was measured by 2H NMR to monitor conversion of [6,6-2H2]D-glucose to [2H]-labelled L-lactate at baseline and in response to NKA inhibition with ouabain. Intracellular [Na+]i was titrated using isotonic buffers with varying [Na+] and [K+] and introducing an artificial Na+ plasma membrane leak using the ionophore gramicidin-A. Experiments were carried out in parallel with cell viability assays, 1H NMR metabolomics of intracellular and extracellular metabolites, extracellular flux analyses and in vivo measurements in a MDA-MB-231 human-xenograft mouse model using 2-deoxy-2-[18F]fluoroglucose (18F-FDG) positron emission tomography (PET). RESULTS: Intracellular [Na+]i was elevated in human and murine breast cancer cells compared to control MCF-10A cells. Acute inhibition of NKA by ouabain resulted in elevated [Na+]i and inhibition of glycolytic flux in all three human cancer cells which are ouabain sensitive, but not in the murine cells which are ouabain resistant. Permeabilization of cell membranes with gramicidin-A led to a titratable increase of [Na+]i in MDA-MB-231 and 4T1 cells and a Na+-dependent increase in glycolytic flux. This was attenuated with ouabain in the human cells but not in the murine cells. 18FDG PET imaging in an MDA-MB-231 human-xenograft mouse model recorded lower 18FDG tumour uptake when treated with ouabain while murine tissue uptake was unaffected. CONCLUSIONS: Glycolytic flux correlates with Na+-driven NKA activity in breast cancer cells, providing evidence for the 'centrality of the [Na+]i-NKA nexus' in the mechanistic basis of the Warburg effect.
