Sucralose (C12H19Cl3O8) impact on microbial activity in estuarine and freshwater marsh soils.

As the general population's diet has shifted to reflect current weight-loss trends, there has been an increase in zero-calorie artificial sweetener usage. Sucralose (C12H19Cl3O8), commonly known as Splenda® in the USA, is a primary example of these sweeteners. In recent years, sucralose has been identified as an environmental contaminant that cannot easily be broken down via bacterial decomposition. This study focuses on the impact of sucralose presence on microbial communities in brackish and freshwater systems. Microbial respiration and fluorescence were measured as indicators of microbial activity in sucralose-dosed samples taken from both freshwater and estuarine marsh environments. Results showed a significant difference between microbial concentration and respiration when dosed with varying levels of sucralose. Diatom respiration implied a negative correlation of community abundance with sucralose concentration. The freshwater cyanobacterial respiration increased in the presence of sucralose, implying a positive correlation of community abundance with sucralose concentration. This was in direct contrast to its brackish water counterpart. However, further investigation is necessary to confirm any potential utility of these communities in the breakdown of sucralose in the marsh environment.

Effects of common artificial sweeteners at environmentally relevant concentrations on soil springtails and their gut microbiota.

Artificial sweeteners (AS) are extensively utilized as sugar substitutes and have been recognized as emerging environmental contaminants. While the effect of AS on aquatic organisms has garnered recent attention, their effects on soil invertebrates and gut microbial communities remain unclear. To address this knowledge gap, we exposed springtails (Folsomia candida) to both single and combined treatments of four typical AS (sucralose [SUC], saccharin [SAC], cyclamate [CYC], and acesulfame [ACE]) at environmentally relevant concentrations of 0.01, 0.1 and 1 mg kg-1 in soil. Following the first-generational exposure, the reproduction of juveniles showed a significant increase under all the AS treatments of 0.1 mg kg-1. The transcriptomic analysis revealed significant enrichment of several Kyoto Encyclopedia of Gene and Genome pathways (e.g., glycolysis/gluconeogenesis, pentose and glucuronate interconversions, amino sugar, and nucleotide sugar metabolism, ribosome, and lysosome) in springtails under all AS treatments. Analysis of gut bacterial microbiota indicated that three AS (SUC, CYC, and ACE) significantly decreased alpha diversity, and all AS treatments increased the abundance of the genus Achromobacter. After the sixth-generational exposure to CYC, weight increased, but reproduction was inhibited. The pathways that changed significantly (e.g., extracellular matrix-receptor interaction, amino sugar and nucleotide sugar metabolism, lysosome) were generally similar to those altered in first-generational exposure, but with opposite regulation directions. Furthermore, the effect on the alpha diversity of gut microbiota was contrary to that after first-generational exposure, and more noticeable disturbances in microbiota composition were observed. These findings underscore the ecological risk of AS in soils and improve our understanding of the toxicity effects of AS on living organisms.

Acesulfame degradation by thermally activated persulfate: Kinetics, transformation products and estimated toxicity.

The existence of the artificial sweetener acesulfame (ACE) in quantities of significance can negatively impact water quality, and its consumption has been associated with deleterious health effects. The present investigation explores the efficacy of heat-activated sodium persulfate (SPS) for eliminating ACE. The complete degradation of 0.50 mg L-1 of ACE was achieved within 45 min under a reaction temperature of 50 °C and 100 mg L-1 of SPS. The impact of thermal decomposition on ACE at a temperature of 60 °C was negligible. This study considers several factors, such as the SPS and ACE loading, the reaction temperature, the initial pH, and the water matrix of the reactor. The results indicate that the method's efficiency is positively correlated with higher initial concentrations of SPS, whereas it is inversely associated with the initial concentration of ACE. Furthermore, higher reaction temperatures and acidic initial pH levels promote the degradation of acesulfame. At the same time, certain constituents of the water matrix, such as humic acid, chlorides, and bicarbonates, can hinder the degradation process. Additionally, the data from LC-QToF-MS analysis of the samples were used to investigate transformation through suspect and non-target screening approaches. Overall, ACE's eight transformation products (TPs) were detected, and a potential ACE decomposition pathway was proposed. The concentration of TPs followed a volcano curve, decreasing in long treatment times. The ecotoxicity of ACE and its identified TPs was predicted using the ECOSAR software. The majority of TPs exhibited not harmful values.

Determination of the genotoxic effects of sweeteners, mannitol and lactitol.

The changes in dietary habit around the world have led to an increased use of additives in the food. The safety of food additives has been a main focus of research for many years due to the ongoing debate on their potential effects on health. In this study, the in vitro genotoxic effects of mannitol and lactitol, polyols used as sweetener food additives, were evaluated using chromosomal aberrations (CAs) and micronucleus (MN) assays in human peripheral lymphocytes. Additionally, the effects of these sweeteners on the mitotic index (MI) and nuclear division index (NDI) were investigated. Concentrations of 500, 1000, 2000, 4000, and 8000 µg/mL for mannitol and 250, 500, 1000, 2000, and 4000 µg/mL for lactitol were used. The results indicated that both polyols did not affect CA and MN frequency, and did not cause a significant change in NDI at all treatment concentratoins. However, mannitol (except at concentrations of 500 and 1000 µg/mL) and lactitol (except at 250 µg/mL) significantly decreased the MI compared to the control at almost all concentrations and treatment times. In conclusion, it was observed that mannitol and lactitol did not have a significant genotoxic effect at the concentrations used in human lymphocytes in vitro.

Stability of aspartame in the soft drinks: Identification of the novel phototransformation products and their toxicity evaluation.

Photolytic transformation of aspartame - a widely used artificial sweetener - under the simulated sunlight was studied for the first time. The experiments were conducted in pH range of 2.5 - 7.0 and in eight soft drinks available in the market. The highest degradation rate in the tested buffered solutions was observed under the neutral pH conditions. Irradiation of the soft drinks resulted in significantly (up to tenfold) faster degradation of aspartame, regardless of its initial concentration in the beverage. Such considerable acceleration of decomposition, not reported for aspartame so far, was ascribed to influence of the co-occurring ingredients, which can act as the photosensitizers. These findings indicate that some formulations may be particularly unfavorable in the context of aspartame photostability. Qualitative analysis of the studied processes revealed formation of six phototransformation products including three previously not described. In silico estimation of toxicity showed that some of the identified photoproducts, including the novel phenolic derivatives, may be more harmful than the parent compound. Taking into account relatively extensive formation of those products in the soft drinks, such finding may be particularly important from the food safety point of view.

Cardiotoxic and neurobehavioral effects of sucralose and acesulfame in Daphnia: Toward understanding ecological impacts of artificial sweeteners.

Artificial sweeteners are widely used in food and pharmaceuticals, but their stability and persistence raise concerns about their impact on aquatic life. Although standard toxicity tests do not reveal lethal effects, recent studies suggest a potential neurotoxic mode of action. Using environmentally relevant concentrations, we assessed the effects of sucralose and acesulfame, common sugar substitutes, on Daphnia magna focusing on biochemical (acetylcholinesterase activity; AChE), physiological (heart rate), and behavioural (swimming) endpoints. We found dose-dependent increases in AChE and inhibitory effects on heart rate and behaviour for both substances. Moreover, acesulfame induced a biphasic response in AChE activity, inhibiting it at lower concentrations and stimulating at higher ones. For all endpoints, the EC50 values were lower for acesulfame than for sucralose. Additionally, the relationship between acetylcholinesterase and heart rate differed depending on the substance, suggesting possible differences in the mode of action between sucralose and acesulfame. All observed EC50 values were at µg/l levels, i.e., within the levels reported for wastewater, with adverse effects observed at as low as 0.1 µg acesulfame /l. Our findings emphasise the need to re-evaluate risk assessment thresholds for artificial sweeteners and provide evidence for the neurotoxic effects of artificial sweeteners in the environment, informing international regulatory standards.

Toxicological and pharmacokinetic properties of sucralose-6-acetate and its parent sucralose: in vitro screening assays.

The purpose of this study was to determine the toxicological and pharmacokinetic properties of sucralose-6-acetate, a structural analog of the artificial sweetener sucralose. Sucralose-6-acetate is an intermediate and impurity in the manufacture of sucralose, and recent commercial sucralose samples were found to contain up to 0.67% sucralose-6-acetate. Studies in a rodent model found that sucralose-6-acetate is also present in fecal samples with levels up to 10% relative to sucralose which suggest that sucralose is also acetylated in the intestines. A MultiFlow® assay, a high-throughput genotoxicity screening tool, and a micronucleus (MN) test that detects cytogenetic damage both indicated that sucralose-6-acetate is genotoxic. The mechanism of action was classified as clastogenic (produces DNA strand breaks) using the MultiFlow® assay. The amount of sucralose-6-acetate in a single daily sucralose-sweetened drink might far exceed the threshold of toxicological concern for genotoxicity (TTCgenotox) of 0.15 µg/person/day. The RepliGut® System was employed to expose human intestinal epithelium to sucralose-6-acetate and sucralose, and an RNA-seq analysis was performed to determine gene expression induced by these exposures. Sucralose-6-acetate significantly increased the expression of genes associated with inflammation, oxidative stress, and cancer with greatest expression for the metallothionein 1 G gene (MT1G). Measurements of transepithelial electrical resistance (TEER) and permeability in human transverse colon epithelium indicated that sucralose-6-acetate and sucralose both impaired intestinal barrier integrity. Sucralose-6-acetate also inhibited two members of the cytochrome P450 family (CYP1A2 and CYP2C19). Overall, the toxicological and pharmacokinetic findings for sucralose-6-acetate raise significant health concerns regarding the safety and regulatory status of sucralose itself.

Non-sugar sweeteners and cancer: Toxicological and epidemiological evidence.

Several toxicological and epidemiological studies were published during the last five decades on non-sugar sweeteners (NSS) and cancer. Despite the large amount of research, the issue still continues to be of interest. In this review, we provided a comprehensive quantitative review of the toxicological and epidemiological evidence on the possible relation between NSS and cancer. The toxicological section includes the evaluation of genotoxicity and carcinogenicity data for acesulfame K, advantame, aspartame, cyclamates, saccharin, steviol glycosides and sucralose. The epidemiological section includes the results of a systematic search of cohort and case-control studies. The majority of the 22 cohort studies and 46 case-control studies showed no associations. Some risks for bladder, pancreas and hematopoietic cancers found in a few studies were not confirmed in other studies. Based on the review of both the experimental data on genotoxicity or carcinogenicity of the specific NSS evaluated, and the epidemiological studies it can be concluded that there is no evidence of cancer risk associated to NSS consumption.

Updated systematic assessment of human, animal and mechanistic evidence demonstrates lack of human carcinogenicity with consumption of aspartame.

Aspartame has been studied extensively and evaluated for its safety in foods and beverages yet concerns for its potential carcinogenicity have persisted, driven primarily by animal studies conducted at the Ramazzini Institute (RI). To address this controversy, an updated systematic review of available human, animal, and mechanistic data was conducted leveraging critical assessment tools to consider the quality and reliability of data. The evidence base includes 12 animal studies and >40 epidemiological studies reviewed by the World Health Organization which collectively demonstrate a lack of carcinogenic effect. Assessment of >1360 mechanistic endpoints, including many guideline-based genotoxicity studies, demonstrate a lack of activity associated with endpoints grouped to key characteristics of carcinogens. Other non-specific mechanistic data (e.g., mixed findings of oxidative stress across study models, tissues, and species) do not provide evidence of a biologically plausible carcinogenic pathway associated with aspartame. Taken together, available evidence supports that aspartame consumption is not carcinogenic in humans and that the inconsistent findings of the RI studies may be explained by flaws in study design and conduct (despite additional analyses to address study limitations), as acknowledged by authoritative bodies.

Exosomal MALAT1 Derived from High Glucose-Treated Macrophages Up-Regulates Resistin Expression via miR-150-5p Downregulation.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) plays a crucial role in the pathophysiological process associated with diabetes-related complications. The effect of high glucose levels on macrophage-derived exosomal MALAT1 is unknown. Therefore, we investigated the molecular regulatory mechanisms controlling exosomal MALAT1 in macrophages under high glucose treatment and the therapeutic target of macrophage-derived exosomal MALAT1 using a balloon injury model of vascular disease in diabetic rats. High glucose (25 mM) significantly increased MALAT1 expression in macrophage-derived exosomes. MALAT1 suppressed miR-150-5p expression in macrophage-derived exosomes under high-glucose conditions. Silencing MALAT1 using MALAT1 siRNA significantly reversed miR-150-5p expression induced by macrophage-derived exosomes. Macrophage-derived exosomes under high-glucose treatment significantly increased resistin expression in macrophages. Silencing MALAT1 and overexpression of miR-150-5p significantly decreased resistin expression induced by macrophage-derived exosomes. Overexpression of miR-150-5p significantly decreased resistin luciferase activity induced by macrophage-derived exosomes. Macrophage-derived exosome significantly decreased glucose uptake in macrophages and silencing MALAT1, resistin or overexpression of miR-150-5p significantly reversed glucose uptake. Balloon injury to the carotid artery significantly increased MALAT1 and resistin expression and significantly decreased miR-150-5p expression in arterial tissue. Silencing MALAT1 significantly reversed miR-150-5p expression in arterial tissue after balloon injury. Silencing MALAT1 or overexpression of miR-150-5p significantly reduced resistin expression after balloon injury. In conclusion, high glucose up-regulates MALAT1 to suppress miR-150-5p expression and counteracts the inhibitory effect of miR-150-5p on resistin expression in macrophages to promote vascular disease. Macrophage-derived exosomes containing MALAT1 may serve as a novel cell-free approach for the treatment of vascular disease in diabetes mellitus.

Enhancement of antibiotic resistance dissemination by artificial sweetener acesulfame potassium: Insights from cell membrane, enzyme, energy supply and transcriptomics.

The abuse of antibiotics on animals could induce the development of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB), and acesulfame potassium (ACE) is the widely used artificial sweetener in animal feed. Generally speaking, ACE and ARB often coexist in livestock wastewater, however, the impact of the co-occurrence of ACE and ARB on the transmission of ARGs is still unknown. In this study, the effects of ACE on vertical gene transfer (VGT) and horizontal gene transfer (HGT) were both evaluated. For VGT, ACE may hinder the spread of sul gene in Pseudomonas HLS-6 by blocking ARB growth. As for HGT (from Escherichia coli DH5α to Pseudomonas HLS-6), environmentally relevant ACE concentration could facilitate the conjugative transfer. The underlying mechanisms of HGT were characterized by enhanced cell membrane permeability, reactive oxygen species overproduction, SOS response, energy supply, which were all further verified by the changes in transcription levels of related genes. Interestingly, intracellular Mg2+ in donor strain was found for the first time as an indicator for the conjugation occurrence in ACE treated mating system. This study may provide new insights into the role of ACE on ARGs proliferation and highlight its potential environmental impacts.

Obesogens: How They Are Identified and Molecular Mechanisms Underlying Their Action.

Adult and childhood obesity have reached pandemic level proportions. The idea that caloric excess and insufficient levels of physical activity leads to obesity is a commonly accepted answer for unwanted weight gain. This paradigm offers an inconclusive explanation as the world continually moves towards an unhealthier and heavier existence irrespective of energy balance. Endocrine disrupting chemicals (EDCs) are chemicals that resemble natural hormones and disrupt endocrine function by interfering with the body's endogenous hormones. A subset of EDCs called obesogens have been found to cause metabolic disruptions such as increased fat storage, in vivo. Obesogens act on the metabolic system through multiple avenues and have been found to affect the homeostasis of a variety of systems such as the gut microbiome and adipose tissue functioning. Obesogenic compounds have been shown to cause metabolic disturbances later in life that can even pass into multiple future generations, post exposure. The rising rates of obesity and related metabolic disease are demanding increasing attention on chemical screening efforts and worldwide preventative strategies to keep the public and future generations safe. This review addresses the most current findings on known obesogens and their effects on the metabolic system, the mechanisms of action through which they act upon, and the screening efforts through which they were identified with. The interplay between obesogens, brown adipose tissue, and the gut microbiome are major topics that will be covered.

670nm photobiomodulation modulates bioenergetics and oxidative stress, in rat Müller cells challenged with high glucose.

Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is associated with oxidative stress, nuclear factor-κB (NFκB) activation, and excess production of vascular endothelial growth factor (VEGF) and intracellular adhesion molecule-1 (ICAM-1). Muller glial cells, spanning the entirety of the retina, are involved in DR inflammation. Mitigation of DR pathology currently occurs via invasive, frequently ineffective therapies which can cause adverse effects. The application of far-red to near-infrared (NIR) light (630-1000nm) reduces oxidative stress and inflammation in vitro and in vivo. Thus, we hypothesize that 670nm light treatment will diminish oxidative stress preventing downstream inflammatory mechanisms associated with DR initiated by Muller cells. In this study, we used an in vitro model system of rat Müller glial cells grown under normal (5 mM) or high (25 mM) glucose conditions and treated with a 670 nm light emitting diode array (LED) (4.5 J/cm2) or no light (sham) daily. We report that a single 670 nm light treatment diminished reactive oxygen species (ROS) production and preserved mitochondrial integrity in this in vitro model of early DR. Furthermore, treatment for 3 days in culture reduced NFκB activity to levels observed in normal glucose and prevented the subsequent increase in ICAM-1. The ability of 670nm light treatment to prevent early molecular changes in this in vitro high glucose model system suggests light treatment could mitigate early deleterious effects modulating inflammatory signaling and diminishing oxidative stress.

Zebrafish Behavioral Phenomics Links Artificial Sweetener Aspartame to Behavioral Toxicity and Neurotransmitter Homeostasis.

Artificial sweeteners (ASs) are extensively used as food additives in drinks and beverages to lower calorie intake and prevent lifestyle diseases such as obesity. Although clinical and epidemiological data revealed the link between the chronic overconsumption of ASs and adverse health effects, there still exist controversies over the potential adverse neural toxic effect of ASs such as aspartame (APM), with acceptable daily intake (ADI) for a long time, on human health. In addition, whether APM and its metabolites are neurotoxic remains debatable due to a lack of data from an animal experiment or clinical investigation. Herein, to fully describe the potential neurological effect of APM, adult zebrafish served as the animal model to assess neurophysiological alteration induced by APM exposure within the range of the ADI (1, 10, and 100 mg/L) for 2 months. A cohort of standardized neurobehavioral phenotyping assays was conducted, including light/dark preference tests (LDP), novel tank diving tests, novel object recognition tests, social interaction tests, and color preference tests. For instance, in the LDP test, saccharin remarkably decreased the swimming time of zebrafish in the DARK part from 111 ± 10.8 (control group) to 72.2 ± 11.4 (100 mg/L groups). Besides, brain chemistry involved in the alteration of total neurotransmitters was determined by LC-MS/MS to confirm the behavioral results. Overall, current research studies revealed that APM within the range of the ADI altered the total behavioral profiles of zebrafish and disturbed the homeostasis of neurotransmitters in the brain. The present study has established a set of experimental paradigms, revealing the standardized procedure of using adult zebrafish to determine the neural activity or toxicity of AS molecules phenotypically. Zebrafish behavioral phenotyping methods, which were characterized by a cohort of behavioral fingerprints, can link the phenotypical alteration to changes in neurotransmitters in the brain, so as to provide a predictive reference for the further exploration of the molecular mechanism of phenotypic changes induced by ASs.

Melatonin Suppresses Apoptosis of Nucleus Pulposus Cells through Inhibiting Autophagy via the PI3K/Akt Pathway in a High-Glucose Culture.

Diabetes mellitus- (DM-) associated hyperglycemia promotes apoptosis of disc nucleus pulposus (NP) cells, which is a contributor to intervertebral disc degeneration (IDD). Melatonin is able to protect against cell apoptosis. However, its effects on apoptosis of NP cell in a high-glucose culture remain unclear. The purpose of the present study was to investigate the effects and molecular mechanism of melatonin on NP cell apoptosis in a high-glucose culture. NP cells were cultured in the baseline medium supplemented with a high-glucose concentration (0.2 M) for 3 days. The control cells were only cultured in the baseline medium. Additionally, the pharmaceutical inhibitor LY294002 was added along with the culture medium to investigate the possible role of the PI3K/Akt pathway. Apoptosis, autophagy, and activity of the PI3K/Akt pathway of NP cells among these groups were evaluated. Compared with the control NP cells, high glucose significantly increased cell apoptosis ratio and caspase-3/caspase-9 activity and decreased mRNA expression of Bcl-2, whereas it increased mRNA or protein expression of Bax, caspase-3, cleaved caspase-3, cleaved PARP, and autophagy-related molecules (Atg3, Atg5, Beclin-1, and LC3-II) and decreased protein expression of p-Akt compared with the control cells. Additionally, melatonin partly inhibited the effects of high glucose on those parameters of cell apoptosis, autophagy, and activation of PI3K/Akt. In conclusion, melatonin attenuates apoptosis of NP cells through inhibiting the excessive autophagy via the PI3K/Akt pathway in a high-glucose culture. This study provides new theoretical basis of the protective effects of melatonin against disc degeneration in a DM patient.

Forskolin regulates retinal endothelial cell permeability through TLR4 actions in vitro.

To investigate whether forskolin, a protein kinase A agonist, regulates toll-like receptor 4 actions on retinal endothelial cell permeability in vitro. We also evaluated whether PKA could regulate TLR4 signaling independent of exchange protein activated by cAMP in REC in culture. REC were grown in normal (5 mM) or high (25 mM) glucose. Cells were treated with forskolin to increase PKA levels, siRNA against TLR4, siRNA against myeloid differentiation primary response 88, siRNA against translocating chain associated membrane protein 1, siRNA against epac1, or scrambled siRNA, or a combination of these treatments. Western blotting was done for zonula occludens 1 and occludin protein levels, as well as TLR4 signaling cascade proteins. Permeability measurements were done for REC in culture following inhibition of TLR4 or its signaling cascades. Forskolin restored high glucose-associated decreases in ZO-1 and occludin, which was associated with improved in vitro permeability levels. Both forskolin and TLR4 inhibition reduced high glucose-induced increases in REC permeability, but the actions were not cooperative. Forskolin regulated both MyD88-dependent and -independent signaling pathways, independent of Epac1. Finally, blockade of MyD88 or TRAM1 reduced permeability in REC grown in high glucose. A PKA agonist regulated TLR4 signaling independent of Epac1. PKA agonism or TLR4 inhibition is effective at reducing high glucose-induced permeability in REC in vitro. These studies offer new avenues for therapeutic development.

Long non-cording RNA XIST promoted cell proliferation and suppressed apoptosis by miR-423-5p/HMGA2 axis in diabetic nephropathy.

This research studied the effect of long non-coding RNA X-inactive-specific transcript (XIST) on DN. The effect of high glucose (HG) on the expression of XIST and miR-423-5p was detected by quantitative real-time PCR (qRT-PCR) in human kidney (HK) cells (human glomerular mesangial cells (HMCs) and human kidney-2 (HK-2) cells). The effect of XIST depletion and miR-423-5p inhibition or overexpression on high mobility group protein A2 (HMGA2) protein level was examined by western blot in HG-induced HK cells. The impacts of XIST depletion on viability and apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry assays in HG-induced HK cells. We found the expression of XIST and HMGA2 protein was significantly upregulated in DN tissues and cells. Moreover, HG treatment induced the upregulation of XIST and HMGA2 protein level in HK cells. Besides, both XIST depletion and HMGA2 depletion decreased cell proliferation but increased apoptosis in HG-treated HK cells. Furthermore, HMGA2 upregulation or miR-423-5p inhibition partly eliminated the effects of XIST depletion on cell proliferation, apoptosis of HG-treated HK cells. Interestingly, HMGA2 upregulation partly reversed miR-423-5p overexpression-mediated suppression on viability and promotion on apoptosis in HG-treated HK cells. Mechanistically, XIST sponged miR-423-5p to regulate HMGA2 expression in DN cells. Taken together, XIST depletion suppressed proliferation and promoted apoptosis via miR-423-5p/HMGA2 axis in HG-treated HK cells, which may provide a potential therapeutic target for DN.

Megakaryocytes Mediate Hyperglycemia-Induced Tumor Metastasis.

High blood glucose has long been established as a risk factor for tumor metastasis, yet the molecular mechanisms underlying this association have not been elucidated. Here we describe that hyperglycemia promotes tumor metastasis via increased platelet activity. Administration of glucose, but not fructose, reprogrammed the metabolism of megakaryocytes to indirectly prime platelets into a prometastatic phenotype with increased adherence to tumor cells. In megakaryocytes, a glucose metabolism-related gene array identified the mitochondrial molecular chaperone glucose-regulated protein 75 (GRP75) as a trigger for platelet activation and aggregation by stimulating the Ca2+-PKCα pathway. Genetic depletion of Glut1 in megakaryocytes blocked MYC-induced GRP75 expression. Pharmacologic blockade of platelet GRP75 compromised tumor-induced platelet activation and reduced metastasis. Moreover, in a pilot clinical study, drinking a 5% glucose solution elevated platelet GRP75 expression and activated platelets in healthy volunteers. Platelets from these volunteers promoted tumor metastasis in a platelet-adoptive transfer mouse model. Together, under hyperglycemic conditions, MYC-induced upregulation of GRP75 in megakaryocytes increases platelet activation via the Ca2+-PKCα pathway to promote cancer metastasis, providing a potential new therapeutic target for preventing metastasis. SIGNIFICANCE: This study provides mechanistic insights into a glucose-megakaryocyte-platelet axis that promotes metastasis and proposes an antimetastatic therapeutic approach by targeting the mitochondrial protein GRP75.

Quantification and cytotoxicity of degradation products (chloropropanols) in sucralose containing e-liquids with propylene glycol and glycerol as base.

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

Overall lack of genotoxic activity among five common low- and no-calorie sweeteners: A contemporary review of the collective evidence.

Low- and no-calorie sweeteners (LNCS) are food additives that have been widely consumed for many decades. Their safety has been well established by authoritative bodies globally and is re-evaluated periodically. The objective herein was to survey and summarize the genotoxicity potential of five commonly utilized LNCS: acesulfame potassium (Ace-K), aspartame, saccharin, steviol glycosides and sucralose. Data from peer-reviewed literature and the ToxCast/Tox21 database were evaluated and integrated with the most recent weight-of-evidence evaluations from authoritative sources. Emphasis was placed on assays most frequently considered for hazard identification and risk assessment: mutation, clastogenicity and/or aneugenicity, and indirect DNA damage, such as changes in DNA repair mechanisms or gene expression data. These five sweeteners have been collectively evaluated in hundreds of in vivo or in vitro studies that employ numerous testing models, many of which have been conducted according to specific testing guidelines. The weight-of-evidence demonstrates overall negative findings across assay types for each sweetener when considering the totality of study design, reliability and reporting quality, as well as the lack of carcinogenic responses (or lack of responses relevant to humans) in animal cancer bioassays as well as observational studies in humans. This conclusion is consistent with the opinions of authoritative sources that have consistently determined that these sweeteners lack mutagenic and genotoxic potential.