Molecular mechanisms of acrolein toxicity: relevance to human disease

Strategy-Level Prodrug Synthesis

Organic synthesis uniquely provides opportunities to access molecules that serve defined purposes. Medicinal chemistry illustrates this attribute well with prodrug design, whereby a drug undergoes a late-stage conversion to a conditionally responsive active medicinal agent (AMA), being a notable example. Prodrugs are becoming increasingly important in medicinal chemistry but common approaches to introduce biologically responsive groups are limited in the chemoselectivity and scope of available functionalization reactions. This Concept article describes strategy-level prodrug synthesis, which is a powerful extension of classical prodrug formation that initiates sequences with the objective of introducing functionality early in a sequence to achieve greater scope, site-selectivity, and chemoselectivity for the incorporation of the biologically responsive group. Examples of functionalization using alkyne hydroamination, Curtius reaction, and alkene metathesis are highlighted along with the use of the prodrugs for biological applications.

Unveiling the nexus between environmental exposures and testicular damages: revelations from autophagy and oxidative stress imbalance

Recent evidence consolidates the deleterious impact of environmental exposure on testicular damage. Environmental exposures can instigate testicular toxicity, causing damage to the Sertoli-Sertoli cell-mediated blood-testis barrier (BTB) integrity, alterations in hormone levels orchestrated by aberrant Leydig cells, and disruption of spermatogenesis. Despite diverse study designs and methodologies, a consensus is emerging on how environmental factors induce oxidative stress by elevating ROS levels, affecting autophagy through pathways such as the ROS-mediated mTOR signaling pathway, ultimately culminating in testicular damage. This review synthesizes existing literature on how environmental exposures, including metals, air pollutants, industrial contaminants, and pesticides, disturb testicular homeostasis via autophagy-mediated oxidative stress, highlighting recent significant advancements. It also explores interventions like antioxidant support and autophagy regulation to alleviate testicular damage. These findings underscore the importance of elucidating the mechanisms of autophagy influenced by environmental exposures in disrupting the equilibrium of oxidative stress, identifying potential drug targets, and establishing a groundwork for enhancing future treatments and clinical management of testicular injuries.

Ferroptosis-activating metabolite acrolein antagonizes necroptosis and anti-cancer therapeutics

Dysregulated cell death leading to uncontrolled cell proliferation is a hallmark of cancer. Chemotherapy-induced cell death is critical for the success of cancer treatment but this process is impaired by metabolic byproducts. How these byproducts interfere with anti-cancer therapy is unclear. Here, we show that the metabolic byproduct acrolein derived from polyamines, tobacco smoke or fuel combustion, induces ferroptosis independently of ZBP1, while suppressing necroptosis in cancer cells by inhibiting the oligomerization of the necroptosis effector MLKL. Loss of the enzyme SAT1, which contributes to intracellular acrolein production, sensitizes cells to necroptosis. In mice, administration of an acrolein-trapping agent relieves necroptosis blockade and enhances the anti-tumor efficacy of the chemotherapeutic drug cyclophosphamide. Human patients with cancer coupled with a higher cell death activity but a lower expression of genes controlling polyamine metabolism exhibit improved survival. These findings highlight that the removal of metabolic byproducts improves the success of certain chemotherapies.

An analog of phenelzine demonstrates effective acrolein scavenging and neuroprotection without monoamine oxidase inhibition in a rat SCI model

Oxidative stress is widely recognized as a critical factor in the functional deficits after spinal cord injury (SCI). Oxidative stress and lipid peroxidation-derived aldehydes such as acrolein are known to play a key role in SCI pathology and have therefore emerged as valuable therapeutic targets. This study introduces a novel phenelzine analogue (PhzA), designed to retain the acrolein scavenging capability of phenelzine (Phz) while removing its undesirable monoamine oxidase (MAO) inhibition effects through structure-based modification. Using a rat model of contusion SCI, we showed that PhzA significantly reduced acrolein levels in both the acute and chronic stages of SCI with minimal MAO inhibition. In addition, PhzA reduced excessive microglial and astrocytic activation, dampening inflammation and gliosis. Furthermore, PhzA-treated rats exhibited significant improvements in motor function and reduction in mechanical hypersensitivity for up to 28 days post-injury compared to untreated rats. These findings further underscore the crucial role of aldehydes in SCI pathology and strengthen the notion that acrolein could serve as an effective therapeutic target for mitigating post-SCI neurodegeneration. These results also indicate that the expansion of acrolein-scavenging drug discovery through structure-based modification of existing repurposed drugs, such as with Phz, is a viable strategy with the benefit of a likely accelerated path towards clinical application. This effort may also benefit a range of neuronal diseases and injuries beyond SCI where acrolein is implicated, advancing the health of millions of patients.

Environmental impact assessment of waste plastic modified asphalt mixtures: VOCs emission characteristics, environmental-health risks, and underlying mechanism

Incorporating waste plastics into asphalt mixtures offers dual benefits of enhancing performance and reducing white pollution, while also necessitating consideration of their environmental impact. This work quantitatively investigated the effects of waste high-density polyethylene (wHDPE), polyvinyl chloride (wPVC), and polypropylene (wPP) plastics on volatile organic compounds (VOCs) emissions and associated environmental-health risks of asphalt mixtures prepared via the dry method under simulated paving conditions, with mechanistic insights into the impacts. Results revealed that waste plastics could improve high-temperature and water stability. Meanwhile, these selected waste plastics can effectively reduce the total VOCs concentrations of asphalt mixture, with a maximum inhibition rate of 36.72 % by wPP. Alkanes and aldehydes (81.41 % of total VOCs) were decreased by over 30 %. Meanwhile, wPP was the most effective in reducing environmental and health impacts, achieving up to 39.7 %, 33 %, and 27.7 % inhibition of ozone formation potential, secondary organic aerosol formation potential, and cancer risk, respectively. However, the addition of wPVC and high-dose wHDPE increased hazardous emissions such as benzene series and halogenated hydrocarbons due to thermal degradation under high temperature. These findings underscore the importance of waste plastic type/dosage optimization to address performance-environmental trade-offs, providing valuable guidance for sustainable waste plastic reuse in road engineering.

Association Between Volatile Organic Compounds and Circadian Syndrome Among Pre- and Postmenopausal Women

Air pollution is closely associated with the development of multiple metabolic diseases. Circadian syndrome (CircS), as an extended concept of metabolic syndrome (MetS), has been proven to be a better predictor of metabolic diseases than MetS. However, the relationship between volatile organic compounds (VOCs) and CircS in pre- and postmenopausal women remains unclear. This study used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2020, including 520 premenopausal women and 531 postmenopausal women. Generalized linear model (GLM), restricted cubic spline (RCS) model, subgroup analyses, and weighted quantile sum (WQS) model were used to assess the relationship between VOCs and CircS. In addition, sensitivity analyses were performed to evaluate the robustness of the results. Our findings showed that seven VOC metabolites were positively associated with the risk of CircS in postmenopausal women. In premenopausal women, only two VOC metabolites were positively associated with the risk of CircS. The WQS analysis further confirmed that VOC mixtures selected by a least absolute shrinkage and selection operator (LASSO) were significantly associated with an increased risk of CircS in postmenopausal women, with HPMMA identified as the primary contributor to the combined effect. This association was not evident in premenopausal women. Meanwhile, in postmenopausal women, individual urinary VOC metabolites and VOC mixtures were observed to be positively associated with elevated glucose and short sleep. Our results highlighted that VOC exposure was strongly associated with the occurrence of CircS in postmenopausal women. Further research is needed to confirm this conclusion.

NLRP3 as a therapeutic target in cyclophosphamide-associated toxicities

Cyclophosphamide (CPM), a potent chemotherapeutic agent, while effective against various cancers, can cause significant organ damage. The NLRP3 inflammasome, a key player in the innate immune response, is implicated in this toxicity. This review delves into the intricate relationship between CPM and NLRP3 inflammasome activation, focusing on oxidative stress-mediated organ damage. We explore the mechanisms by which CPM induces NLRP3 activation in the kidneys, heart, liver, and gastrointestinal tract. Additionally, we examine the signaling pathways involved in this process. The review also discusses potential therapeutic interventions, including phytotherapeutic agents, that target NLRP3 inflammasome activation to mitigate CPM-induced organ injury. By highlighting the crucial role of NLRP3 in CPM-related toxicity, this review provides a foundation for future research aimed at developing novel therapeutic strategies to minimize adverse effects and improve patient outcomes.

The Protective Effect of Ellagic Acid and Its Metabolites Against Organ Injuries: A Mitochondrial Perspective

Mitochondria are essential for maintaining health, and dysfunction of them leads to various diseases. Their role is not limited to energy production but serves multiple mechanisms varying from calcium hemostasis, reactive oxygen species production, and regulation of apoptotic cell death. In recent years, several strategies have been developed to preserve mitochondria. Ellagic acid (EA) is a polyphenol extracted from many plants. The intestinal microflora converts EA to urolithins with high bioavailability. EA and urolithins exhibit mitochondrial-protective effects by regulating mitochondrial complexes, sirtuins, mitophagy, and mitochondrial antioxidant enzymes. This review highlights the mito-protective effects of EA and urolithins on mitochondrial injuries induced by various drugs and toxic compounds.

Ultraprocessed Foods and Neuropsychiatric Outcomes: Putative Mechanisms

A body of evidence indicates an association between ultraprocessed foods (UPFs) and health outcomes. Most of it has been obtained through preclinical studies, although a number of observational studies substantiate how a high intake of these products increases the risk of neuropsychiatric disorders, and an increasing amount of dietary intervention studies confirm these findings. The aim of this narrative review is to describe some of the putative mechanisms involved in the deleterious effects of a high intake of UPFs on neuropsychiatric outcomes. A myriad of unhealthy actions may be associated with the consumption of UPFs, and some mechanisms are being discussed. They include UPFs' high caloric density; their high sugar, sodium, and additives content and low amounts of fiber; and a high palatability that induces overconsumption, acting as obesogens. Moreover, thermal treatment of these foods generates oxidative products such as glycotoxins, lipotoxins, and acrolein, all of which affect the brain. The chemical products act, directly or indirectly, on the gut microbiome and affect the gut-brain axis, causing neuroinflammation, oxidative stress, and neurodegeneration. UPFs also exert various epigenetic effects that affect mental health and might explain the intergenerational inheritance of neuropsychiatric disorders. A diet containing a high proportion of these foods has a low nutritional density, including bioactive protective agents such as antioxidant and anti-inflammatory compounds that promote eubiosis. The evidence shows that UPFs intake affects neuropsychiatric outcomes such as neurodegeneration, cognitive decline, dementia, and mood disorders and reinforces the need to promote a healthy dietary pattern throughout all life stages, thus interfering with the current commercial determinants of health.

Associations between vaping during pregnancy and perinatal outcomes: A systematic review and meta-analysis

Despite numerous studies linking prenatal vaping to adverse perinatal outcomes, a systematic assessment for critical comparison remains absent. To investigate these associations, we conducted a systematic search of studies assessing perinatal outcomes in mothers and/or neonates exposed to vaping during pregnancy compared to those in women without prenatal vaping exposure through MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, PROSPERO, and Google Scholar until July 5, 2024. We performed inverse-variance random-effects meta-analyses for maternal and neonatal outcomes of 23 studies with a total of 924,376 participants with 7552 reporting vaping-only use during pregnancy. Prenatal vaping was associated with 53 % higher odds of an adverse maternal outcome (OR: 1.53; 95 % CI: 1.27-1.85; I2 = 80 %), particularly with decreased breastfeeding (OR: 0.53; 95 % CI: 0.38-0.72; I2 = 45 %) and reduced prevalence of adequate prenatal care (OR: 0.69; 95 % CI: 0.56-0.86; I2 = 82 %). Prenatal vaping was also associated with a similarly 53 % higher odds of an adverse neonatal outcome (OR: 1.53; 95 % CI: 1.34-1.76; I2 = 45 %), such as low birth weight (OR: 1.56; 95 % CI: 1.28-1.93; I2: 15 %), preterm birth (OR: 1.49; 955 CI: 1.27-1.76; I2: 0 %), and small for gestational age (OR: 1.48; 955 CI: 1.16-1.89; I2: 70 %). This is the first comprehensive systematic review and meta-analysis demonstrating vaping during pregnancy as a risk factor for increased odds of both maternal and neonatal outcomes and underscores the urgency to address awareness and regulations of vaping and its potential harms to both humans and the environment. REGISTRATION: PROSPERO CRD42023446266.

Acrolein exposure associated with kidney damage: a cross‑sectional study

Acrolein (Acr) is a common volatile toxic substance excreted by the kidneys. There are no studies that specifically look at the effects of Acr on kidney function. This study was designed to investigate the relationship between Acr and kidney damage. A cross-sectional study of data (n = 4951) from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) was conducted. Participants' urinary Acr concentration, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio (UACR) were recorded based on laboratory tests. The number of participants with chronic kidney disease (CKD) was counted. Urinary Acr concentration was divided into quartiles. The association of urinary Acr with CKD and eGFR was investigated using multivariate linear regression, multivariate logistic regression, and smooth curve fitting. Subgroup analyses, interaction tests and sensitivity analyses were used to examine the independence of the Acr-CKD and Acr-eGFR associations in the population. In 4951 participants, urinary Acr concentration was positively associated with CKD risk and negatively associated with eGFR. In the fully adjusted model, each log2Acr increase of one unit was associated with a 6% increased risk of CKD (OR = 1.06, 95% CI 1.01, 1.13) and a 0.54 mL/min/1.73 m2 decrease in eGFR (β = - 0.54, 95% CI - 0.95, - 0.13). For categorical log2Acr, for each log2Acr increase of one unit, the risk of CKD was 29% higher in the Q4 group than in the Q1 group (OR = 1.29, 95% CI 1.01, 1.64), while eGFR was 1.9 mL/min/1.73 m2 lower in the Q4 group than in the Q1 group (β = - 1.90, 95% CI - 3.65, - 0.14). Smooth curve fitting confirmed urinary Acr's nonlinear positive and negative correlations with CKD and eGFR. According to subgroup analyses, sensitivity analyses and interaction tests, the confounding variables did not affect the independent correlations of urinary Acr with CKD and eGFR. Our study found that Acr exposure was significantly associated with kidney damage. Our study provides a new piece of research evidence to support a link between the volatile toxic substance Acr and a decline in kidney function.

Dimethyl Fumarate Attenuates Cyclophosphamide-Induced Bladder Damage and Enhances Cytotoxic Activity Against SH-SY5Y Cells

Cylophosphamide (CP)-induced acute cystitis is a debilitating bladder dysfunction commonly observed in cancer patients, primarily resulting from oxidative damage and inflammation in the bladder tissue. Dimethyl fumarate (DMF) is a fumaric acid ester approved for the treatment of multiple sclerosis due to its antioxidant and anti-inflammatory properties. Thus, we aimed to investigate the multiple effects of DMF, involving both its potential synergistic effect with CP on the SH-SY5Y cells and its uroprotective effect on CP-induced acute cystitis. Female Balb/c mice were orally administrated DMF (100 or 300 mg/kg/day) for five consecutive days before a single intraperitoneal (i.p) dose of CP. Mesna was administered 20 min before and at 4 h, 8 h after CP application. Following 24 h of CP injection, bladders were removed for functional, biochemical analysis and evaluation of vesical vascular permeability. SH-SY5Y cell viability was assayed by MTT test. CP markedly decreased carbachol-induced contraction of detrusor strips (p < 0.01), which was prevented by the high-dose DMF treatment (p < 0.05). Evans blue dye extravasation was greatly increased in the bladders of cystitis group (p < 0.001), which was significantly decreased in DMF-treated mice with cystitis (p < 0.01). Total GSH content was decreased (p < 0.01) whereas TNF-α level was increased (p < 0.05) in the bladders of cystitis group. High-dose DMF-treated mice showed an increment in total GSH content (p < 0.05) without any alterations on TNF-α levels of the bladders with cystitis. Additionally, combination of different concentrations of CP and DMF exhibited a potent synergistic cytotoxic effect in SH-SY5Y cells. DMF improved CP-induced acute cystitis by partially suppressing oxidative stress and inflammation, while also enhancing the cytotoxic effects of CP.

Disposable electronic cigarettes - chemical composition and health effects of their use. A systematic review

OBJECTIVE

Despite the rising popularity of disposable e-cigarettes, little is known about their chemical characteristics, or their impact on users' health. This work attempts to summarize current knowledge about chemical composition and known health effects of disposable e-cigarettes.

METHODS

The literature search was performed in February and March 2024 in Pub Med and Science Direct databases (no time range) by the terms 'disposable electronic cigarette', 'disposable e-cigarette', 'disposable e-cigs', 'cig-a-like e-cigarette', 'cig-a-like electronic cigarette'.

RESULTS

Disposable e-cigarettes contain: nicotine, humectants (propylene glycol, glycerin), flavoring agents (diacetyl, acetoin, triacetin, p-menthone, triethyl citrate, ethyl maltol, 3-hexen-1-ol, methyl anthranilate, α-terpineol, perillartine, benzyl alcohol, vanillin, melonal, methyl dihydrojasmonate, and γ-decalactone), cooling agents (WS-3, WS-23, menthol), carbonyl compounds (acetaldehyde, formaldehyde, propionaldehyde, acetone, acrolein) volatile organic compounds (VOCs) (benzene, ethanol, methanol, styrene, acetylpirazine and 2,3,5-trimethylpyrazine), metals and inorganic compounds (chromium, nickel, manganese, lead, aluminum, and zinc) and reactive oxygen species. Furthermore, there was some evidence of nicotine dependence, risk of cancer and adverse respiratory effects of using disposable e-cigarettes.

CONCLUSIONS

Despite the fact that disposable e-cigarettes contain significantly less toxins compared to combustible cigarettes, they include compounds that are absent in such products that may provide health risk in prolonged usage. In addition, there is a limited number of data on the health effect of disposable e-cigarettes, especially in long time period, for never-smokers. Therefore, due to growing popularity of disposable e-cigarettes among young people, who choose them when initiating nicotine use, further research on their long-term impact of on the users' health is necessary.

Carnosine supplementation improves cognitive outcomes in younger participants of the NEAT trial

Some prior studies suggested that supplementation with carnosine or β-alanine can improve cognitive abilities and neurodegenerative disorders in certain elderly or at-risk populations. However, the efficacy of carnosine in improving cognitive performance in a healthy, adult population has not been assessed. We examined this as a post-hoc secondary outcome in the placebo-controlled, randomized Nucleophilic Defense Against PM Toxicity (NEAT) clinical trial (NCT03314987). Participants in this trial were instructed to take either cornstarch (placebo) or carnosine capsules (2g daily) for up to 12wk. Cognitive ability was assessed using the Cognition test battery, which consists of ten individual tests known to engage specific brain systems and covering a range of cognitive domains. Speed, accuracy, and efficiency were obtained for the whole battery as well as for each of the ten individual tests. Participant testing occurred at baseline, prior to randomization, after approximately 6wk of supplementation (Follow-up-1), and after approximately 12wk of supplementation (Follow-up-2). Of the 299 participants who were randomized, we obtained useable measures for 242 participants at Follow-up-1 and 231 ​at Follow-up-2. Age-based stratification (23-35 years, 36-50 years, 51-65 years), showed statistically significant improvements in overall speed and efficiency in the youngest age group stratum at both follow-up visits. This same group also demonstrated significant improvements in seven speed or accuracy scores of the individual tests. The other age groups demonstrated few or no significant improvements. Thus, in a study population largely devoid of susceptibility factors or pre-existing conditions, carnosine supplementation selectively improved high-level cognitive performance in young individuals.

Estimating the association between cigarette and e-cigarette use patterns and SARS-CoV-2 negative conversion time: retrospective online survey in China

BACKGROUND

Cigarette smoking has been reported to be associated with SARS-CoV-2 negative conversion, while little is known about the effect of its dual use with e-cigarettes. This study aimed to investigate whether tobacco product use patterns including e-cigarette use were linked with delayed negative conversion of SARS-CoV-2.

METHODS

An online national survey was conducted from January 28 through February 21, 2023, targeting a community-based population in mainland of China after peak waves of the coronavirus disease 2019 (COVID-19). Participants were followed from the onset of COVID-19 symptoms until the negative conversion day or the day of answering the questionnaire as the endpoint of the study. Multi-variable adjusted Cox proportional hazard models were used to compare the negative conversion time of SARS-CoV-2 across different cigarette and e-cigarette use patterns.

RESULTS

A total of 66,537 participants infected with COVID-19 were enrolled and 13,294 were included in the analyses. During the median duration of 7 days (interquartile range 5 to 10 days), a total of 11,587 (87.2%) had a negative conversion. Compared with never users, current exclusive smokers (multi-variable adjusted HR 0.59, 95% CI 0.48-0.71), current dual users (HR 0.31, 95% CI 0.22-0.44), and previous smokers (HR 0.56, 95% CI 0.37-0.83) took longer to turn negative after 10 days of follow-up.

CONCLUSIONS

Both current exclusive cigarette use and dual use of cigarettes and e-cigarettes were associated with the delayed negative conversion of SARS-CoV-2, which strengthens the importance of smoking and vaping cessation messaging and community-based tobacco control strategies during pandemics like COVID-19 next time.

Polyamine biosynthesis dysregulation in Alzheimer's disease and Down syndrome cellular models

BACKGROUND

Individuals with Down Syndrome (DS) frequently develop early onset Alzheimer's disease (AD) with pathological hallmarks closely resembling AD due to several triplicated genes on chromosome 21. Polyamines are small, organic molecules that play a pivotal role for growth and differentiation, and a dysregulation of polyamine pathways is implicated in AD pathology. However, their role in DS-associated AD is unclear.

METHODS

We analyzed polyamines and their metabolite levels in mouse hippocampal cells and human DS-AD and AD hippocampal tissue and assessed the effects of the ODC inhibitor difluoromethylornithine (DFMO) on Aβ42 aggregation and protein expression in DS fibroblasts.

RESULTS

Amyloid-β42 increased polyamine levels via ornithine decarboxylase (ODC) activation in a dose-dependent manner. DFMO reduced Aβ42 aggregation, decreased amyloid precursor protein (APP) levels, and normalized proteins linked to AD pathology in DS fibroblasts. Polyamine levels were elevated in DS-AD hippocampal tissue, with colocalization of ODC and Aβ42 aggregates.

CONCLUSION

These findings suggest that polyamine biosynthesis may exacerbate Aβ42 toxicity and APP expression, contributing to AD progression in DS. The ability of DFMO to reduce Aβ42 aggregation and restore protein homeostasis presents the polyamine pathway as a therapeutic target for DS-AD management.

The association analysis between exposure to volatile organic compounds and fatty liver disease in US Adults

BACKGROUND

Limited epidemiological research has explored the associations between ambient volatile organic compounds (VOCs) and fatty liver disease (FLD). This study aimed to explore the associations between VOCs and FLD and liver function biomarkers. We obtained urinary concentrations of VOCs metabolites from NHANES.

METHODS

Weighted logistic regression models were employed to investigate the relationships between VOCs and FLD risk, including alcoholic FLD (AFLD) and non-alcoholic FLD (NAFLD). The associations of VOCs and liver function biomarkers were also investigated using weighted linear regression.

RESULTS

Among the 2050 participants, 774 were classified as having FLD. After adjustment, each log-transformed SD increase in N-Acetyl-S-(2-carboxyethyl)-l-cysteine (CEMA), 2-Aminothiazoline-4-carboxylicacid (ATCA), and trans-trans-muconic-acid (MUCA) had a OR (95%CI) of 1.30 (1.06-1.61; P-trend=0.014), 1.34 (1.12-1.61; P-trend=0.002), and 1.22 (1.01-1.47; P-trend=0.035), respectively. ATCA and MUCA were associated with higher risks of NAFLD (OR=1.47, 95%CI: 1.20-1.79, and OR=1.26, 95%CI: 1.02-1.56, respectively). VOCs were positively associated with gamma glutamyl transaminase (GGT) and C-reactive protein (CRP), while inversely associated with albumin, total protein and alanine aminotransferase (ALT) (P < 0.05).

CONCLUSIONS

Urinary metabolites of VOCs have been found to be strongly correlated with a higher risk of FLD and NFALD, and impaired liver function. These novel findings merit further prospective studies to comprehend the effect of VOCs on liver diseases.

AlkA Glycosylase and AlkB Dioxygenase Constitute an Effective Protective System for Endogenously Arising Acrolein: E. coli AlkA Glycosylase Excises Acrolein Adduct to Adenine

Acrolein (ACR) is a ubiquitous environmental pollutant but also formed endogenously as a metabolite in oxidative stress conditions. Its adduct to adenine 1,N6-α-hydroxypropanoadenine (HPA) is a mutagenic lesion effectively repaired by the AlkB dioxygenase. Here, we provide in vivo, in vitro, and in silico evidence that it is also the substrate for the AlkA glycosylase. We studied the role of AlkA and AlkB in E. coli cells under conditions of induced adaptive response. Both alkA and alkB defective strains were not more sensitive to exogenous ACR than the wild type was. To simulate endogenously arising adducts, we used acrolein-modified plasmids, allowing monitoring of all kinds of substitutions originating from the acrolein modification of adenine. Both the AlkA and AlkB proteins were engaged in alleviating HPA-induced mutagenesis. Moreover, HPA was effectively repaired by AlkA and AlkB in vivo, even without induction of adaptive response. These findings suggest that the main contribution to acrolein mutagenicity comes from its endogenous sources, whereas AlkA and AlkB can play an additional role in controlling the level of DNA adducts of endogenous origin. Acrolein does not induce the adaptive response. HPA contains an asymmetric carbon atom in the hydroxypropano ring and exists as two stereoisomers. AlkA excises both of them in vitro. Molecular modelling demonstrated how dsDNA carrying both HPA stereoisomers could be properly bound at the AlkA catalytic centre. So, in contrast to the reaction catalyzed by AlkB, the HPA repair by AlkA is not expected to be stereoselective.

Chemoselective Stabilized Triphenylphosphonium Probes for Capturing Reactive Carbonyl Species and Regenerating Covalent Inhibitors with Acrylamide Warheads in Cellulo

Reactive carbonyl species (RCS) are important biomarkers of oxidative stress-related diseases because of their highly reactive electrophilic nature. Despite their potential as triggers for prodrug activation, selective labeling approaches for RCS remain limited. Here, we utilized triphenylphosphonium groups to chemoselectively capture RCS via an aqueous Wittig reaction, forming α,β-unsaturated carbonyls that enable further functionalization. We first designed native (light) and deuterated (heavy) probes to facilitate RCS metabolomic identification through distinct MS isotope patterns. This approach allowed us to capture and relatively quantify several endogenous RCS related to advanced lipoxidation/glycation end products (ALEs/AGEs). Second, we demonstrated that various endogenous RCS can trigger the in situ generation of acrylamide warheads of targeted covalent inhibitors (TCIs) with different substituents. These structural variations influence their protein binding profiles and consequently alter their cytotoxicity, which is beneficial for the development of inhibitor cocktails.

Spermine oxidase inhibitor, MDL 72527, reduced neovascularization, vascular permeability, and acrolein-conjugated proteins in a mouse model of ischemic retinopathy

Disruptions in polyamine metabolism have been identified as contributing factors to various central nervous system disorders. Our laboratory has previously highlighted the crucial role of polyamine oxidation in retinal disease models, specifically noting elevated levels of spermine oxidase (SMOX) in inner retinal neurons. Our prior research demonstrated that inhibiting SMOX with MDL 72527 protected against vascular injury and microglial activation induced by hyperoxia in the retina. However, the effects of SMOX inhibition on retinal neovascularization and vascular permeability, along with the underlying molecular mechanisms of vascular protection, remain incompletely understood. In this study, we utilized the oxygen-induced retinopathy (OIR) model to explore the impact of SMOX inhibition on retinal neovascularization, vascular permeability, and the molecular mechanisms underlying MDL 72527-mediated vasoprotection in the OIR retina. Our findings indicate that inhibiting SMOX with MDL 72527 mitigated vaso-obliteration and neovascularization in the OIR retina. Additionally, it reduced OIR-induced vascular permeability and Claudin-5 expression, suppressed acrolein-conjugated protein levels, and downregulated P38/ERK1/2/STAT3 signaling. Furthermore, our results revealed that treatment with BSA-Acrolein conjugates significantly decreased the viability of human retinal endothelial cells (HRECs) and activated P38 signaling. These observations contribute valuable insights into the potential therapeutic benefits of SMOX inhibition by MDL 72527 in ischemic retinopathy.

SMOX Inhibition Preserved Visual Acuity, Contrast Sensitivity, and Retinal Function and Reduced Neuro-Glial Injury in Mice During Prolonged Diabetes

Diabetic retinopathy, a major cause of vision loss, is characterized by neurovascular changes in the retina. The lack of effective treatments to preserve vision in diabetic patients remains a significant challenge. A previous study from our laboratory demonstrated that 12-week treatment with MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX, a critical regulator of polyamine metabolism), reduced neurodegeneration in diabetic mice. Utilizing the streptozotocin-induced diabetic mouse model and MDL 72527, the current study investigated the effectiveness of SMOX inhibition on the measures of vision impairment and neuro-glial injury following 24 weeks of diabetes. Reductions in visual acuity, contrast sensitivity, and inner retinal function in diabetic mice were improved by MDL 72527 treatment. Diabetes-induced changes in neuronal-specific class III tubulin (Tuj-1), synaptophysin, glutamine synthetase, and vimentin were attenuated in response to SMOX inhibition. In conclusion, our findings show that SMOX inhibition improved visual acuity, contrast sensitivity, and inner retinal function and mitigated diabetes-induced neuroglial damage during long-term diabetes. Targeting SMOX signaling may provide a potential strategy for reducing retinal neuronal damage and preserving vision in diabetes.

Acrolein scavengers and detoxification: From high-throughput screening of flavonoids to mechanistic study of epigallocatechin gallate

Acrolein (ACR) is a widespread, highly toxic substance that poses significant health risks. Flavonoids have been recognized as effective ACR scavengers, offering a possible way to reduce these risks. However, the lack of specific high-throughput screening methods has limited the identification of ACR scavengers, and their actual detoxifying capacity on ACR remains unknown. To address this, we developed a high-throughput screening platform to assess the ACR scavenging capacity of 322 flavonoids. Our results showed that 80.7 % of the flavonoids could scavenge ACR, but only 34.4 % exhibited detoxifying effects in an ACR-injured QSG7701 cell model. Some flavonoids even increased toxicity. Structure-activity relationship (SAR) analysis indicated that galloyl and pyrogallol units enhance scavenging but worsen ACR-induced cytotoxicity. Further investigation revealed that epigallocatechin gallate (EGCG) could exacerbate ACR-induced redox disorder, leading to cell apoptosis. Our findings provide crucial data on the scavenging and detoxifying capacities of 322 flavonoids, highlighting that ACR scavengers might not mitigate ACR-induced toxicity and could pose additional safety risks.

Novel fluorescent nanoplatform for all-in-one sensing and removal of acrolein: An ultrasensitive probe to evaluate its removal efficiency

As a highly toxic aldehyde, acrolein is widely found in diet and environment, and can be produced endogenously, posing a serious threat to human health. Herein, we designed a novel fluorescent nanoplatform integrating carbon dots‑manganese dioxide (CDs-MnO2) and glutathione (GSH) for all-in-one sensing and removal of acrolein. By converting Mn4+ to free Mn2+, GSH inhibited the inner filter effect (IFE) of MnO2 nanosheets, and the Michael addition of acrolein with GSH inhibited the GSH-induced Mn4+ conversion, forming an "off-on-off" fluorescence response of CDs. The developed fluorescent nanoplatform exhibited high sensitivity (LOD was 0.067 μM) and selectivity for the simultaneous detection and removal of acrolein. The combination of CDs-MnO2 hydrogels with smartphones realized the point-of-care detection of acrolein, yielding satisfactory results (recovery rates varied between 97.01-104.65%, and RSD ranged from 1.42 to 4.16%). Moreover, the capability of the nanoplatform was investigated for on-site evaluating acrolein scavengers' efficacy, demonstrating excellent potential for practical application.

Post-harvest processed parsnip showed improved anti-oxidative capacity and protective potential against acrolein-induced inflammation in vitro and in vivo

Introduction

Post-harvest processing plays a crucial role in enhancing the bioactive properties of vegetables. This study aimed to investigate the impact of post-harvest aging on parsnip's bioactive profile and its protective effects against acrolein (Acr)-induced inflammation, a common pollutant and irritant linked to respiratory inflammation.

Methods

Parsnips (Pastinaca sativa L.) were aged at 60°C for up to 30 days, with extracts collected at intervals. Total phenolic content (TPC) and antioxidant capacity were assessed using DPPH assays. Key bioactive compounds, including falcarindiol, DDMP, and 5-HMF, were quantified. In vitro studies used BEAS-2B cells to evaluate anti-inflammatory effects, while in vivo tests involved treating Acr-exposed mice with aged parsnip extract to observe cytokine responses.

Results

Aged parsnip extracts showed a 9.96-fold increase in TPC and a 4.25-fold increase in antioxidant capacity after 30 days. Bioactive compounds significantly increased in aged samples, especially falcarindiol and 5-HMF. In vitro, aged parsnip reduced Acr-induced TNF-α and IL-1β expression. In vivo, treated mice showed reduced bronchial inflammation, goblet cell hyperplasia, and cytokine expression compared to controls.

Discussion

These findings suggest that post-harvest aging enhances parsnip's antioxidant and anti-inflammatory properties, highlighting its potential as a functional food ingredient for managing inflammation and respiratory health.

Mitochondrial Dysfunction in Environmental Toxicology: Mechanisms, Impacts, and Health Implications

Mitochondria, pivotal to cellular metabolism, serve as the primary sources of biological energy and are key regulators of intracellular calcium ion storage, crucial for maintaining cellular calcium homeostasis. Dysfunction in these organelles impairs ATP synthesis, diminishing cellular functionality. Emerging evidence implicates mitochondrial dysfunction in the etiology and progression of diverse diseases. Environmental factors that induce mitochondrial dysregulation raise significant public health concerns, necessitating a nuanced comprehension and classification of mitochondrial-related hazards. This review systematically adopts a toxicological perspective to illuminate the biological functions of mitochondria, offering a comprehensive exploration of how toxicants instigate mitochondrial dysfunction. It delves into the disruption of energy metabolism, the initiation of mitochondrial fragility and autophagy, and the induction of mutations in mitochondrial DNA by mutagens. The overarching objective is to enhance our understanding of the repercussions of mitochondrial damage on human health.

Potent and Selective Oxidatively Labile Ether-Based Prodrugs through Late-Stage Boronate Incorporation

This manuscript describes a new strategy for prodrug synthesis in which a relatively inert ether group is introduced at an early stage in a synthetic sequence and functionalized in the final step to introduce a prodrug-activating group through a chemoselective process. Boryl allyloxy (BAO) ether groups are synthesized through several metal-mediated processes to form entities that are readily cleaved under oxidative conditions commonly found in cancer cells. The high cleavage propensity of the BAO group allows for ether cleavage, making these compounds substantially more hydrolytically stable in comparison to acyl-linked prodrugs while retaining the ability to release alcohols. We report the preparation of prodrug analogues of the natural products camptothecin and pederin from acetal precursors that serve as protecting groups in their synthetic sequences. The BAO acetal groups cleave in the presence of hydrogen peroxide to release the cytotoxic agents. The pederin-based prodrug shows dramatically greater cytotoxicity than negative controls and outstanding selectivity and potency toward cancer cell lines in comparison to non-cancerous cell lines. This late-stage functionalization approach to prodrug synthesis should be applicable to numerous systems that can be accessed through chemoselective processes.

Adenosine protects cardiomyocytes against acrolein-induced cardiotoxicity by enhancing mitochondrial homeostasis, antioxidant defense, and autophagic flux via ERK-activated FoxO1 upregulation

Acrolein is a ubiquitous gaseous air pollutant and endogenous toxicant, which poses strong risk for oxidative stress-related diseases such as cardiovascular disease. Adenosine has been identified as potential therapeutic agent for age-related cardiovascular disease, while the molecular mechanisms underlying its cardioprotection remain elusive. In the present study, we investigated the myocardial protective effects and the mechanism of adenosine on acrolein-induced toxicity in H9c2 cells and primary neonatal rat cardiomyocytes. We found that acrolein caused apoptosis of cardiomyocytes resulting from oxidative damage, autophagy defect, and mitochondrial dysfunction, as evidenced by loss of mitochondrial membrane potential, impairment of mitochondrial biogenesis, dynamics, and oxidative phosphorylation, decrease of mitochondrial deoxyribonucleic acid (mtDNA) copy number and adenosine 5'-triphosphate (ATP) production. Adenosine pretreatment protected against acrolein-induced cardiotoxicity by maintaining mitochondrial homeostasis, activating the phase II detoxifying enzyme system, promoting autophagic flux, and alleviating mitochondrial-dependent apoptosis. We further demonstrated that the up-regulation of forkhead box protein O1 (FoxO1) mediated by extracellular regulated protein kinases (ERK) activation contributes to the cardioprotection of adenosine. These results expand the application of adenosine in cardioprotection to preventing myocardial damages induced by environmental pollutant acrolein exposure, and uncover the adenosine-ERK-FoxO1 axis as the underlying mechanism mediating the protection of mitochondrial homeostasis, Nrf2-mediated antioxidant defense and autophagic flux, shedding light on the better understanding about the pathological mechanism of cardiovascular disease caused by environmental pollutants and applications of adenosine in cardioprotection.

Aldehyde-induced DNA-protein crosslinks- DNA damage, repair and mutagenesis

Aldehyde exposure has been shown to lead to the formation of DNA damage comprising of DNA-protein crosslinks (DPCs), base adducts and interstrand or intrastrand crosslinks. DPCs have recently drawn more attention because of recent advances in detection and quantification of these adducts. DPCs are highly deleterious to genome stability and have been shown to block replication forks, leading to wide-spread mutagenesis. Cellular mechanisms to prevent DPC-induced damage include excision repair pathways, homologous recombination, and specialized proteases involved in cleaving the covalently bound proteins from DNA. These pathways were first discovered in formaldehyde-treated cells, however, since then, various other aldehydes have been shown to induce formation of DPCs in cells. Defects in DPC repair or aldehyde clearance mechanisms lead to various diseases including Ruijs-Aalfs syndrome and AMeD syndrome in humans. Here, we discuss recent developments in understanding how aldehydes form DPCs, how they are repaired, and the consequences of defects in these repair pathways.

Study of Liposomes Containing Extract from the Leaves of Protium heptaphyllum (Aubl.) March in Animals Submitted to a Mutagenic Model Induced by Cyclophosphamide

Cyclophosphamide (CPA) is an alkylating agent used as a chemotherapy agent in the treatment of cancer, but it has immunosuppressive effects. Protium heptaphyllum (P. heptaphyllum) is a plant rich in triterpenes and flavonoids, with some bioactive and therapeutic properties presented in the literature. Thus, the present study aimed to investigate the chemoprotective potential of P. heptaphyllum extract inserted into liposomes against oxidative damage chemically induced by CPA. Male Swiss mice received 1.5 mg/kg of P. heptaphyllum liposomes as a pre-treatment for 14 consecutive days (via gavage) and 100 mg/kg of CPA in a single dose (via intraperitoneal) on the 15th day. After the experimental period, blood and organ samples were collected for histopathological and biochemical analyses, including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione S-transferase (GST), reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS), ascorbic acid (ASA), carbonyl protein, cytokine measurement, and micronucleus testing. The results showed that liposomes containing P. heptaphyllum extract have an antimutagenic effect against damage induced to DNA by CPA, and that they also protect against oxidative stress, as verified by the increase in the antioxidant enzymes SOD and GPx. The improvement in alkaline phosphatase and creatinine markers suggests a beneficial effect on the liver and kidneys, respectively. However, the depletion of GSH in the liver and brain suggests the use of antioxidants for the metabolism of molecules generated in these tissues. In general, these data show good prospects for the use of P. heptaphyllum liposomes as a cancer chemoprotective agent, as well as possible antioxidant action, conceivably attributed to the flavonoids present in the plant extract.

Association between biomarkers of tobacco smoke exposure and clinical efficacy of ivacaftor in the G551D observational trial (GOAL)

BACKGROUND

Acrolein, an aldehyde in smoke from tobacco products, inhibits CFTR function in vitro. Ivacaftor is an FDA-approved potentiator that improves mutant CFTR function. This human clinical study investigated the relationship between two urinary markers of tobacco smoke exposure - the acrolein metabolite 3-HPMA and the nicotine metabolite NNAL - and sweat chloride response to ivacaftor in the G551D Observational Trial (GOAL).

METHODS

3-HPMA (low: <50th centile; moderate: 50-75th centile; high: >75th centile) and NNAL (detectable/undetectable) in GOAL samples was quantified with LC-MS/MS. Self-report of tobacco smoke exposure (Y/N) served as a subjective measure. Change in sweat chloride from pre- to 6 months post-ivacaftor treatment (ΔSC) was the primary CFTR-dependent readout.

RESULTS

The sample included 151 individuals, mean age 20.7 (SD 11.4) years, range 6-59 years. Smoke exposure prevalence was 15 % per self-reports but 27 % based on detectable NNAL. 3-HPMA was increased in those reporting tobacco smoke exposure (607 vs 354 ng/ml, p = 0.008), with a higher proportion of smoke-exposed in the high- vs low-acrolein group (31 % vs 9 %, p=0.040). Compared to low-acrolein counterparts, high-acrolein participants experienced less decrease in sweat chloride (-35.2 vs -48.2 mmol/L; p = 0.020) and had higher sweat chloride values (50.6 vs 37.6 mmol/L; p = 0.020) 6 months post-ivacaftor. The odds of ivacaftor-mediated potentiation to near normative CFTR function (defined as SC6mo <40 mmol/L) was more than twice as high in the low-acrolein cohort (OR: 2.51, p = 0.026).

CONCLUSIONS

Increased urinary 3-HPMA, an acrolein metabolite of tobacco smoke, is associated with a diminished sweat chloride response to ivacaftor potentiation of CFTR function.

Health outcomes of electronic cigarettes

ABSTRACT

The usage of electronic cigarettes (e-cigarettes) sparked an outbreak of unidentified vaping-related lung disease in the US during late 2019. With e-cigarettes becoming more and more popular, smokers have more options other than conventional cigarettes. Under these circumstances, a comprehensive evaluation of the general safety of new tobacco and tobacco-related products, represented by e-cigarettes, to human health is necessary. In this review, we summarize the current research on potential negative impacts of e-cigarette exposure on human health. In particular, studies detailing the relationship between e-cigarettes and the digestive system are summarized, with mechanisms mainly including hepatic metabolic dysfunction, impaired gut barrier, and worsened outcomes of inflammatory bowel disease (IBD). Although believed to be safer than traditional cigarettes, e-cigarettes exert adverse effects on systemic health and induce the development of multiple diseases including asthma, cardiovascular disease, and IBD. Moreover, nicotine-containing e-cigarettes have a negative impact on the childhood development and increase the risk of arterial stiffness compared to the non-nicotine e-cigarettes. However, non-nicotine e-cigarette components have detrimental effects including promoting liver damage and metabolic disorders.

Enzymatic Acrolein Production System and Its Impact on Human Cells

Acrolein is an environmental toxicant and is also generated by microbial metabolism in the intestinal tract. Aqueous acrolein rapidly dissipates from standard human cell culture media with nondetectable levels after 8 h, hindering cell-based studies to understand its biological impacts. Thus, we developed an extracellular acrolein biosynthesis system to continuously produce acrolein compatible with human cell culture conditions. The approach uses spermine as a precursor, amine oxidase found in fetal calf serum, and catalase to remove the hydrogen peroxide byproduct. We confirmed amine oxidase activity of calf serum using a colorimetric assay and further tested the requirement for catalase in the system to mitigate hydrogen peroxide-induced cytotoxicity. We calibrated responses of human colon cells to this enzymatic acrolein production system by comparing transcriptional responses, DNA adduct formation and cytotoxicity responses to either this system or pure acrolein exposures in a human colon cell line. Several genes related to oxidative stress including HMOX1, and the colorectal cancer-related gene SEMA4A were upregulated similarly between the enzymatic acrolein production system or pure acrolein. The acrolein-DNA adduct γ-OH-Acr-dG increased in a dose-dependent manner with spermine in the enzymatic acrolein production system, producing a maximum of 1065 adducts per 108 nucleosides when 400 μM spermine was used. This biosynthetic production method provides a relevant model for controlled acrolein exposure in cultured human cells and overcomes current limitations due to its physical properties and limited availability.

Predicting non-chemotherapy drug-induced agranulocytosis toxicity through ensemble machine learning approaches

Agranulocytosis, induced by non-chemotherapy drugs, is a serious medical condition that presents a formidable challenge in predictive toxicology due to its idiosyncratic nature and complex mechanisms. In this study, we assembled a dataset of 759 compounds and applied a rigorous feature selection process prior to employing ensemble machine learning classifiers to forecast non-chemotherapy drug-induced agranulocytosis (NCDIA) toxicity. The balanced bagging classifier combined with a gradient boosting decision tree (BBC + GBDT), utilizing the combined descriptor set of DS and RDKit comprising 237 features, emerged as the top-performing model, with an external validation AUC of 0.9164, ACC of 83.55%, and MCC of 0.6095. The model's predictive reliability was further substantiated by an applicability domain analysis. Feature importance, assessed through permutation importance within the BBC + GBDT model, highlighted key molecular properties that significantly influence NCDIA toxicity. Additionally, 16 structural alerts identified by SARpy software further revealed potential molecular signatures associated with toxicity, enriching our understanding of the underlying mechanisms. We also applied the constructed models to assess the NCDIA toxicity of novel drugs approved by FDA. This study advances predictive toxicology by providing a framework to assess and mitigate agranulocytosis risks, ensuring the safety of pharmaceutical development and facilitating post-market surveillance of new drugs.

Toxicity mechanism of acrolein on energy metabolism disorder and apoptosis in human ovarian granulosa cells

Acrolein (ACR), an unsaturated, highly reactive aldehyde, is a widespread environmental toxin. ACR exerts permanent and irreversible side effects on ovarian functions. Granulosa cells play a crucial role in supporting ovarian function. Thus, in this study, we investigated the toxicity effects of granulosa cells induced by ACR. Following treatment with varying ACR concentrations (0, 12.5, 25, 50, and 100 μM), we observed that ACR exposure induced reactive oxygen species accumulation, mitochondrial energy metabolism disorder, and apoptosis in KGN cells (a human ovarian granulosa cell line) in a dose-dependent manner. In addition, mitochondrial biogenesis in KGN cells displayed biphasic changes after ACR exposure, with activation at a low ACR dose (12.5 μM), but inhibition at higher ACR doses (≥50 μM). SIRT1/PGC-1α-mediated mitochondrial biogenesis is crucial for maintaining intracellular mitochondrial homeostasis and cellular function. The inhibition/activation of the SIRT1/PGC-1α pathway in KGN cells validated its role in ACR-induced damage. The results indicated that the inhibition of the SIRT1/PGC-1α pathway aggravated ACR-induced cell damage, whereas its activation partially counteracted ACR-induced cell damage. This study attempted to uncover a novel mechanism of ACR-induced ovarian toxicity so as to provide an effective treatment option for safeguarding female reproductive health from the adverse effects of ACR.

Hydrogen sulfide protects against toxicant acrolein-induced ferroptotic cell death in Sertoli cells

Acrolein (ACR) is a ubiquitous environmental pollutant and byproduct of lipid peroxidation that has been implicated in male infertility. However, the molecular mechanisms underlying ACR-induced toxicity in Sertoli cells remain unclear. Given its role in inducing oxidative stress, we examined whether ferroptosis, an iron-dependent form of regulated cell death, could mediate ACR toxicity in Sertoli cells. We also tested if hydrogen sulfide (H2S), which has antioxidant and ACR detoxifying properties, could protect Sertoli cells from ACR-induced ferroptosis. ACR exposure decreased Sertoli cell viability, increased protein carbonylation and p38 MAPK phosphorylation, indicating oxidative injury. ACR also depleted glutathione (GSH), downregulated the cystine importer SLC7A11, increased intracellular ferrous iron (Fe2+) and lipid peroxidation, suggesting activation of ferroptosis. Consistently, the ferroptosis inhibitor deferoxamine (DFO) markedly attenuates ACR-induced cell death. Further studies revealed that ACR-induced ferroptotic changes were prevented by exogenous H2S and exaggerated by inhibition of endogenous H2S production. Furthermore, H2S also suppressed GPX4 inhibitor RSL3-induced intracellular ACR accumulation and ferroptosis. In summary, our study demonstrates that ACR induces ferroptotic cell death in Sertoli cells, which can be prevented by H2S through multiple mechanisms. Targeting the H2S pathway may represent a therapeutic strategy to mitigate ACR-induced Sertoli cell injury and preserve male fertility.

In-depth mechanistic analysis including high-throughput RNA sequencing in the prediction of functional and structural cardiotoxicants using hiPSC cardiomyocytes

BACKGROUND

Cardiotoxicity remains one of the most reported adverse drug reactions that lead to drug attrition during pre-clinical and clinical drug development. Drug-induced cardiotoxicity may develop as a functional change in cardiac electrophysiology (acute alteration of the mechanical function of the myocardium) and/or as a structural change, resulting in loss of viability and morphological damage to cardiac tissue.

RESEARCH DESIGN AND METHODS

Non-clinical models with better predictive value need to be established to improve cardiac safety pharmacology. To this end, high-throughput RNA sequencing (ScreenSeq) was combined with high-content imaging (HCI) and Ca2+ transience (CaT) to analyze compound-treated human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

RESULTS

Analysis of hiPSC-CMs treated with 33 cardiotoxicants and 9 non-cardiotoxicants of mixed therapeutic indications facilitated compound clustering by mechanism of action, scoring of pathway activities related to cardiomyocyte contractility, mitochondrial integrity, metabolic state, diverse stress responses and the prediction of cardiotoxicity risk. The combination of ScreenSeq, HCI and CaT provided a high cardiotoxicity prediction performance with 89% specificity, 91% sensitivity and 90% accuracy.

CONCLUSIONS

Overall, this study introduces mechanism-driven risk assessment approach combining structural, functional and molecular high-throughput methods for pre-clinical risk assessment of novel compounds.

Water-pipe Tobacco Components and their Association with Oxidative Stress

Oxidative stress (OS) results from an imbalance between the formation and detoxification of reactive species. Although reactive species at low or moderate levels play numerous physiological roles, high concentrations can lead to disturbances in signaling and metabolic pathways and cause different metabolic, chronic, and age-related disorders. Several endogenous and exogenous processes may lead to the formation of reactive species. The severity of OS can be reduced with the help of antioxidants. Tobacco is one of the most important environmental factors contributing to reactive species production. After cigarette smoking, water-pipe tobacco (WPT) smoking is ranked as the second most popular tobacco product. Its popularity is proliferating due to flavored products, social acceptability, etc. However, studies have shown that WPT smoking is associated with an increased risk of arterial stiffness, ischemic heart disease, and several cancer types. In this study, we aimed to review the most recent evidence on WPT smoking constituents and their association with OS.

The Role of Vitamins in Spinal Cord Injury: Mechanisms and Benefits

Spinal cord injury (SCI) is a common neurological disease worldwide, often resulting in a substantial decrease in quality of life, disability, and in severe cases, even death. Unfortunately, there is currently no effective treatment for this disease. Nevertheless, current basic and clinical evidence suggests that vitamins, with their antioxidant properties and biological functions, may play a valuable role in improving the quality of life for individuals with SCI. They can promote overall health and facilitate the healing process. In this review, we discuss the mechanisms and therapeutic potential of vitamins in the treatment of SCI.

Visualization of Acrolein Upregulation during Ferroptosis by a Ratiometric Fluorescent Probe

Ferroptosis is a pattern of cell death caused by iron-dependent accumulation of lipid peroxides and is closely associated with the occurrence and development of multiple diseases. Acrolein (ACR), one of the final metabolites of lipid peroxidation, is a reactive carbonyl species with strong biotoxicity. Effective detection of ACR is important for understanding its role in the progression of ferroptosis and studying the specific mechanisms of ferroptosis-mediated diseases. However, visualization detection of ACR during ferroptosis has not yet been reported. In this work, the first ratiometric fluorescent probe (HBT-SH) based on 2-(2'-hydroxyphenyl) benzothiazole (HBT) was designed for tracing endogenous ACR with an unprecedented regiospecific ACR-induced intramolecular cyclization strategy, which employs 2-aminoethanethiol as an ACR-selective recognition receptor. The experimental results showed that HBT-SH has excellent selectivity, high sensitivity (LOD = 0.26 μM) and good biocompatibility. More importantly, the upregulation of ACR levels was observed during ferroptosis in HeLa cells and zebrafish, indicating that ACR may be a specific active molecule that plays an essential biological role during ferroptosis or may serve as a potential marker of ferroptosis, which has great significance for studying the pathological process and treatment options of ferroptosis-related diseases.

Sexual dimorphism association of combined exposure to volatile organic compounds (VOC) with kidney damage

BACKGROUND

Epidemiological evidence emphasizes air pollutants' role in chronic kidney disease (CKD). Volatile organic compounds (VOCs) contribute to air pollution, yet research on VOCs and kidney damage, especially gender disparities, is limited.

METHODS

This study analyzed NHANES data to explore associations between urinary VOC metabolite mixtures (VOCMs) and key kidney-related parameters: estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), chronic kidney disease (CKD), and albuminuria. Mediation analyses assessed the potential mediating roles of biological aging (BA) and serum albumin in VOCM mixtures' effects on kidney damage. Sensitivity analyses were also conducted.

RESULTS

The mixture analysis unveiled a noteworthy positive association between VOCM mixtures and the risk of developing CKD, coupled with a significant negative correlation with eGFR within the overall participant cohort. These findings remained consistent when examining the female subgroup. However, among male participants, no significant link emerged between VOCM mixtures and CKD or eGFR. Furthermore, in both the overall and female participant groups, there was an absence of a significant correlation between VOCM mixtures and either ACR or albuminuria. On the other hand, in male participants, while no significant correlation was detected with albuminuria, a significant positive correlation was observed with ACR. Pollutant analysis identified potential links between kidney damage and 1,3-butadiene, toluene, ethylbenzene, styrene, xylene, acrolein, crotonaldehyde and propylene oxide. Mediation analyses suggested that BA might partially mediate the relationship between VOCM mixtures and kidney damage.

CONCLUSION

The current findings highlight the widespread exposure to VOCs among the general U.S. adult population and indicate a potential correlation between exposure to VOC mixtures and compromised renal function parameters, with notable gender disparities. Females appear to exhibit greater sensitivity to impaired renal function resulting from VOCs exposure. Anti-aging treatments may offer some mitigation against kidney damage due to VOCs exposure.

Paradoxes: Cholesterol and Hypoxia in Preeclampsia

Preeclampsia, a hypertensive disease of pregnancy of unknown etiology, is intensely studied as a model of cardiovascular disease (CVD) not only due to multiple shared pathologic elements but also because changes that develop over decades in CVD appear and resolve within days in preeclampsia. Those affected by preeclampsia and their offspring experience increased lifetime risks of CVD. At the systemic level, preeclampsia is characterized by increased cellular, membrane, and blood levels of cholesterol; however, cholesterol-dependent signaling, such as canonical Wnt/βcatenin, Hedgehog, and endothelial nitric oxide synthase, is downregulated indicating a cholesterol deficit with the upregulation of cholesterol synthesis and efflux. Hypoxia-related signaling in preeclampsia also appears to be paradoxical with increased Hypoxia-Inducible Factors in the placenta but measurably increased oxygen in maternal blood in placental villous spaces. This review addresses the molecular mechanisms by which excessive systemic cholesterol and deficient cholesterol-dependent signaling may arise from the effects of dietary lipid variance and environmental membrane modifiers causing the cellular hypoxia that characterizes preeclampsia.

Understanding the Cardiovascular Fallout of E-cigarettes: A Comprehensive Review of the Literature

E-cigarettes (ECs) deliver chemicals, including nicotine. They can cause respiratory distress, addiction, cardiovascular effects, and death. More research is needed, especially regarding their impact on the cardiovascular system (CVS) and during pregnancy. Our article aims to fill this gap by summarizing studies elaborating upon the current impact of ECs and the components thereof on the CVS. Acute respiratory distress outbreaks, nicotine addiction, CVS effects, and deaths have been occasionally reported within this cohort, although these events are not uncommon with neighboring age groups. Randomized control trials implying ECs have some contribution toward quitting smoking have been studied. To regulate EC distribution, the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) have created key checkpoints. Additionally, taxation, pricing, age restriction, and media campaigns could be modulated to significantly reduce illicit sales. Education to the users, distributors, and regulators about this product can also play an aiding role in promoting responsible EC use. Another strategy about licensing could be employed, which could incentivize genuine resellers. The effects on CVS and child-bearing by ECs are grim, which calls for strict regulation, awareness, and avoidance by the teetotaler public. They may help individuals stop smoking but not without harming themselves. Strict regulations are necessary to prevent non-judicious use of these devices.

Acrolein Induces Changes in Cell Membrane and Cytosol Proteins of Erythrocytes

High concentrations of acrolein (2-propenal) are found in polluted air and cigarette smoke, and may also be generated endogenously. Acrolein is also associated with the induction and progression of many diseases. The high reactivity of acrolein towards the thiol and amino groups of amino acids may cause damage to cell proteins. Acrolein may be responsible for the induction of oxidative stress in cells. We hypothesized that acrolein may contribute to the protein damage in erythrocytes, leading to the disruption of the structure of cell membranes. The lipid membrane fluidity, membrane cytoskeleton, and osmotic fragility were measured for erythrocytes incubated with acrolein for 24 h. The levels of thiol, amino, and carbonyl groups were determined in cell membrane and cytosol proteins. The level of non-enzymatic antioxidant potential (NEAC) and TBARS was also measured. The obtained research results showed that the exposure of erythrocytes to acrolein causes changes in the cell membrane and cytosol proteins. Acrolein stiffens the cell membrane of erythrocytes and increases their osmotic sensitivity. Moreover, it has been shown that erythrocytes treated with acrolein significantly reduce the non-enzymatic antioxidant potential of the cytosol compared to the control.

Polyamines: the pivotal amines in influencing the tumor microenvironment

Cellular proliferation, function and survival is reliant upon maintaining appropriate intracellular polyamine levels. Due to increased metabolic needs, cancer cells elevate their polyamine pools through coordinated metabolism and uptake. High levels of polyamines have been linked to more immunosuppressive tumor microenvironments (TME) as polyamines support the growth and function of many immunosuppressive cell types such as MDSCs, macrophages and regulatory T-cells. As cancer cells and other pro-tumorigenic cell types are highly dependent on polyamines for survival, pharmacological modulation of polyamine metabolism is a promising cancer therapeutic strategy. This review covers the roles of polyamines in various cell types of the TME including both immune and stromal cells, as well as how competition for nutrients, namely polyamine precursors, influences the cellular landscape of the TME. It also details the use of polyamines as biomarkers and the ways in which polyamine depletion can increase the immunogenicity of the TME and reprogram tumors to become more responsive to immunotherapy.

A comprehensive bibliometric analysis of global research on the role of acrolein in Alzheimer's disease pathogenesis: involvement of amyloid-beta

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive and behavioral decline. Acrolein, an environmental pollutant and endogenous compound, is implicated in AD development. This research employs bibliometric analysis to assess current trends and key areas concerning acrolein-AD interaction.

Methods

The Web of Science was used to extensively review literature on acrolein and AD. Relevant data were systematically gathered and analyzed using VOSviewer, CiteSpace, and an online bibliometric tool.

Results

We identified 120 English publications in this specialized field across 19 journals. The Journal of Alzheimer's Disease was the most prominent. The primary contributors, both in terms of scientific output and influence, were the USA, the University of Kentucky, and Ramassamy C, representing countries/regions, institutions, and authors, respectively. In this field, the primary focus was on thoroughly studying acrolein, its roles, and its mechanisms in AD utilizing both in vivo and in vitro approaches. A significant portion of the research was based on proteomics, revealing complex molecular processes. The main focuses in the field were "oxidative stress," "lipid peroxidation," "amyloid-beta," and "cognitive impairment." Anticipated future research trajectories focus on the involvement of the internalization pathway, covering key areas such as synaptic dysfunction, metabolism, mechanisms, associations, neuroinflammation, inhibitors, tau phosphorylation, acrolein toxicity, brain infarction, antioxidants, chemistry, drug delivery, and dementia. Our analysis also supported our previous hypothesis that acrolein can interact with amyloid-beta to form a protein adduct leading to AD-like pathology and altering natural immune responses.

Conclusion

This study provides a broad and all-encompassing view of the topic, offering valuable insights and guidance to fellow researchers. These emerging directions underscore the continuous exploration of the complexities associated with AD. The analyses and findings aim to enhance our understanding of the intricate relationship between acrolein and AD for future research.

Detection of γ-OHPdG in Circulating Tumor Cells of Patients With Hepatocellular Carcinoma as a Potential Prognostic Biomarker of Recurrence

Background and Aims

Blood-based biomarkers for hepatocellular carcinoma (HCC) and its recurrence are lacking. We previously showed that hepatic γ-hydroxy-1,N 2 -propano-2'-deoxyguanosine (γ-OHPdG), an endogenous DNA adduct derived from acrolein by lipid peroxidation, increased during hepatocarcinogenesis. Additionally, higher hepatic γ-OHPdG from HCC patients after surgery were strongly associated with poor survival (P < .0001) and recurrence-free survival (P = .007) (Fu et al, Hepatology, 2018). These findings suggest that γ-OHPdG is a potential prognostic biomarker for HCC and its recurrence. To attain the goal of using γ-OHPdG as a biomarker in future preventive and therapeutic trials, we developed a blood-based method to detect γ-OHPdG in circulating liver tumor cells from HCC patient blood.

Methods

We first established the specificity of anti-γ-OHPdG antibody by determining its dose-response in HepG2 cells treated with acrolein. Then, HepG2 cells in spiked blood of healthy volunteers and circulating tumor cells (CTCs) from 32 HCC patients were isolated using a RosetteSep CD45 Depletion Cocktail and Ficoll Paque. The HCC CTCs identified with anti-asialoglycoprotein receptor 1, a surface protein expressed solely in hepatocytes, were stained with an anti-γ-OHPdG antibody. The number of total HCC CTCs and γ-OHPdG-positive CTCs, as well as the staining intensity, were quantified using MetaMorph software. As an initial effort toward its clinical application, we also evaluated γ-OHPdG in CTCs from these patients along with certain clinical features.

Results

The γ-OHPdG antibody specificity was demonstrated by an acrolein concentration-dependent increase of γ-OHPdG-positive HepG2 cells and the intensity of γ-OHPdG staining. The recovery of HepG2 cells from spiked blood was ∼50-60%, and the positivity rate of CTCs in blood from 32 patients with advanced HCC was 97%. The MetaMorph analysis showed a wide variation among patients in total number of CTCs, γ-OHPdG positivity, and staining intensity. Statistical analysis revealed that γ-OHPdG in CTCs of these patients appears to be associated with multifocality and poor differentiation.

Conclusion

A blood-based method was developed and applied to HCC patients to evaluate the potential of γ-OHPdG in CTCs as a prognostic biomarker.

Association of volatile organic compound exposure with metabolic syndrome and its components: a nationwide cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is a health issue consisting of multiple metabolic abnormalities. The impact of exposure to volatile organic compounds (VOCs) on MetS and its components remains uncertain. This study aimed to assess the associations of individual urinary metabolites of VOC (mVOCs) and mVOC mixtures with MetS and its components among the general adult population in the United States.

METHODS

A total of 5345 participants with eligible data were filtered from the 2011-2020 cycles of the National Health and Nutrition Examination Survey. Multivariate logistic regression models were applied to assess the associations of individual mVOCs with MetS and its components. The least absolute shrinkage and selection operator (LASSO) regression models were constructed to identify more relevant mVOCs. The weight quantile sum regression model was applied to further explore the links between mVOC co-exposure and MetS and its components.

RESULTS

The results indicated positive associations between multiple mVOCs and MetS, including CEMA, DHBMA, and HMPMA. CEMA was found to be positively correlated with all components of MetS. HMPMA was associated with elevated triglyceride (TG), reduced high-density lipoprotein, and fasting blood glucose (FBG) impairment; 3HPMA was associated with an elevated risk of high TG and FBG impairment; and DHBMA had positive associations with elevated TG and high blood pressure. The co-exposure of LASSO-selected mVOCs was associated with an increased risk of elevated TG, high blood pressure, and FBG impairment.

CONCLUSION

Positive associations of certain individual urinary mVOCs and mVOC mixtures with MetS and its components were observed by utilizing multiple statistical models and large-scale national data. These findings may serve as the theoretical basis for future experimental and mechanistic studies and have important implications for public health.

Aging of plastics in aquatic environments: Pathways, environmental behavior, ecological impacts, analyses and quantifications

The ubiquity of plastics in our environment has brought about pressing concerns, with their aging processes, photo-oxidation, mechanical abrasion, and biodegradation, being at the forefront. Microplastics (MPs), whether originating from plastic degradation or direct anthropogenic sources, further complicate this landscape. This review delves into the intricate aging dynamics of plastics in aquatic environments under various influential factors. We discuss the physicochemical changes that occur in aged plastics and the release of oxidation products during their degradation. Particular attention is given to their evolving environmental interactions and the resulting ecotoxicological implications. A rigorous evaluation is also conducted for methodologies in the analysis and quantification of plastics aging, identifying their merits and limitations and suggesting potential avenues for future research. This comprehensive review is able to illuminate the complexities of plastics aging, charting a path for future research and aiding in the formulation of informed policy decisions.

Associations of individual and mixture exposure to volatile organic compounds with metabolic syndrome and its components among US adults

BACKGROUND

People are exposed to various volatile organic compounds (VOCs) in their environment. Our study aims to examine the links between VOCs exposure and metabolic syndrome (MetS) and its components, as well as identify critical VOCs.

METHOD

In this study, we enrolled 8223 adults from the National Health and Nutrition Examination Survey (NHANES) and analyzed 15 kinds of urinary VOCs metabolites. The Spearman correlation model, generalized linear regression model, restricted cubic spline (RCS), weighted quantile sum (WQS) analysis, and Bayesian kernel machine regression (BKMR) were used to evaluate the association between individual VOC/VOCs mixture and MetS as well as its components.

RESULTS

In generalized linear regression model, compared to the lowest quartile of urinary VOCs metabolites, the highest quartiles of urinary VOC metabolites were positively associated with MetS including N-Acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) (OR: 1.22, 95%CI: 1.00, 1.49), N-Acetyl-S-(2-carboxyethyl)-l-cysteine (CEMA) (OR: 1.71, 95%CI: 1.41, 2.07), N-Acetyl-S-(3-hydroxypropyl)-l-cysteine (3HPMA) (OR: 1.32, 95%CI: 1.11, 1.63), and N-Acetyl-S-(3-hydroxypropyl-1-methyl)-l-cysteine (HMPMA) (OR: 1.34, 95%CI: 1.09, 1.64). Consistent results were found in the dose-response relationship in RCS model. Results of WQS showed that VOCs mixture was positively associated with MetS (OR: 1.16, 95%CI: 1.06, 1.28), elevated WC (OR: 1.25, 95%CI: 1.13, 1.37), elevated FBG (OR: 1.24, 95%CI: 1.12, 1.37), elevated TG (OR: 1.34, 95%CI: 1.21, 1.49), and reduced HDL-C (OR: 1.20, 95%CI: 1.09, 1.33). However, the WQS index was negatively associated with elevated BP (OR: 0.81; 95%CI: 0.70, 0.94). BKMR analysis confirmed that the urinary VOCs mixture was positively associated with MetS, elevated WC, elevated TG, reduced HDL-C, elevated FBG, but negatively associated with elevated BP. CEMA was defined as the most heavily weighted chemical in the WQS and BKMR models.

CONCLUSION

Our findings suggested that exposure to specific VOC or VOCs mixture is associated with the higher risk of MetS and its components, except for elevated BP.