Acrolein, an endogenous aldehyde induces synaptic dysfunction in vitro and in vivo: Involvement of RhoA/ROCK2 pathway.

Acrolein, an unsaturated aldehyde, is increased in the brain of Alzheimer's disease (AD) patients and identified as a potential inducer of sporadic AD. Synaptic dysfunction, as a typical pathological change occurring in the early stage of AD, is most closely associated with the severity of dementia. However, there remains a lack of clarity on the mechanisms of acrolein inducing AD-like pathology and synaptic impairment. In this study, acrolein-treated primary cultured neurons and mice were applied to investigate the effects of acrolein on cognitive impairment and synaptic dysfunction and their signaling mechanisms. In vitro, ROCK inhibitors, Fasudil, and Y27632, could attenuate the axon ruptures and synaptic impairment caused by acrolein. Meanwhile, RNA-seq distinct differentially expressed genes in acrolein models and initially linked activated RhoA/Rho-kinase2 (ROCK2) to acrolein-induced synaptic dysfunction, which could regulate neuronal cytoskeleton and neurite. The Morris water maze test and in vivo field excitatory postsynaptic potential (fEPSP) were performed to evaluate spatial memory and long-term potential (LTP), respectively. Acrolein induced cognitive impairment and attenuated LTP. Furthermore, the protein level of Synapsin 1 and postsynaptic density 95 (PSD95) and dendritic spines density were also decreased in acrolein-exposed mice. These changes were improved by ROCK2 inhibitor Fasudil or in ROCK2+/- mice. Together, our findings suggest that RhoA/ROCK2 signaling pathway plays a critical role in acrolein-induced synaptic damage and cognitive dysfunction, suggesting inhibition of ROCK2 should benefit to the early AD.

Repeated Low-Dose Acrolein Triggers Irreversible Lamina Propria Edema in Urinary Bladder, Transient Voiding Behavior and Widening of Eyes to Mechanical Stimuli.

Acrolein is a metabolite of cyclophosphamide (CYP), an alkylating agent used for a wide range of benign and malignant diseases. CYP treatments are known to trigger hemorrhagic cystitis in patients and animals. Significant effort has been made to prevent CYP/acrolein-induced cystitis, while still maintaining its therapeutic benefits. As a result, supplementary therapeutic options to mediate the protective role against CYP/acrolein and lower doses of CYP are currently given to targeted patients, as compared to past treatments. There is still a need to further study the effects of the repeated low-dose CYP/acrolein on the pathophysiology of the urinary bladder. In our study, a one-time treatment of acrolein and repeated low-dose acrolein triggered the thickening of the smooth muscle and lamina propria in the urinary bladder of C57BL/6J mice, respectively. The first dose of acrolein did not trigger voiding dysfunction, but the second dose triggered high-volume low-frequency voiding. Interestingly, our new scoring criteria and concurrent behavioral assessment revealed that mice with repeated low-dose acrolein had a wider opening of eyes in response to mechanical stimuli. Our study suggests that clinical symptoms among patients undergoing prolonged low-dose CYP may differ from previously reported symptoms of CYP-induced hemorrhagic cystitis.

Contact allergy to fragrance mix I and its components in individuals with photocontact allergy to ketoprofen.

BACKGROUND: Contact allergy to fragrance mix I (FM I) is over-represented in patients photoallergic to ketoprofen. The prevalence of contact allergy to two components of FM I, cinnamal and cinnamyl alcohol, in ketoprofen-photoallergic patients is higher than in dermatitis patients. OBJECTIVE: To explore the prevalence of contact allergy to FM I and its individual components in patients with photocontact allergy to ketoprofen, and to compare with a dermatitis and the general population. METHODS: Data on patch and photopatch tests performed between 2009-2018 were collected. Ketoprofen-photoallergic patients were compared with dermatitis patients and published data on the general population regarding the prevalence and the distribution of contact allergy to FM I and its components. RESULTS: A higher prevalence of contact allergy to cinnamyl alcohol compared with cinnamal (23.3% vs 10.0%), and eugenol compared with isoeugenol (23.3% vs 6.7%), was observed in ketoprofen-photoallergic patients, while the relationship was the opposite in the dermatitis group (0.7% vs 1.05%; 0.4% vs 0.9%). The overall prevalence of contact allergy to several components of FM I was significantly higher in ketoprofen-photoallergic patients. CONCLUSIONS: Contact allergy to FM I and many of its components is over-represented in patients photoallergic to ketoprofen compared with dermatitis patients and the general population.

Fragrance- and Botanical-Related Allergy and Associated Concomitant Reactions: A Retrospective Analysis of the North American Contact Dermatitis Group Data 2007-2016.

IMPORTANCE: When fragrance- and botanical-related (F/BR) allergy is identified, concomitant reaction (CR) frequencies can help direct avoidance recommendations. OBJECTIVE: This study aimed to determine the CR rates for F/BR allergens. DESIGN: A retrospective cross-sectional analysis of the North American Contact Dermatitis Group data 2007-2016 was conducted. Frequencies of demographics, positive reactions, strength of reactions, trends, and CR rates were calculated. RESULTS: A total of 5504 (22.7%) of 24,246 patients had F/BR allergic reactions. The F/BR-sensitive patients were more likely to be female, older than age 40 years, and White and have face, leg, or anal/genital dermatitis. Top allergens included fragrance mix I (FMI, 10.6%), Myroxylon pereirae (balsam of Peru [BOP], 8%), and fragrance mix II (FMII, 4.9%). There were increasing trends for FMI, FMII, cinnamic aldehyde, and Compositae mix and decreasing trends for BOP and propolis. When patients were positive to any F/BR allergen, they were likely to be positive to FMI, FMII, and BOP. Concomitant reactions were bidirectional between multiple fragrance allergens and propolis, colophony, and Compositae mix. CONCLUSIONS: Concomitant reactions were identified between fragrances, between fragrances and BR allergens, and between BR allergens and fragrances. If CRs of greater than 10% suggest cross-reactivity, then all patients with fragrance sensitivity should avoid BR allergens and vice versa.

Acrolein-Trapping Mechanism of Theophylline in Green Tea, Coffee, and Cocoa: Speedy and Successful.

Increasing evidence has identified the unsaturated aldehyde acrolein (ACR) as the potential factor that causes deoxyribonucleic acid cross-linking and the development of chronic diseases. The objective of this study was to investigate the mechanism by which theophylline (TP) scavenges ACR for the first time. TP efficiently scavenged ACR through forming adducts, which was demonstrated in a system in which TP was incubated with ACR at different ratios for different times for liquid chromatography with tandem mass spectrometry. Then, the mono- and di-ACR-TP adducts were purified, and their structures were elucidated by high-resolution mass spectrometry and nuclear magnetic resonance analysis. We found that the ACR residue on mono-ACR-TP further trapped one more ACR and formed di-ACR-TP adducts. Furthermore, mono- and di-ACR-TP had similar time-dependent ACR-scavenging activity to TP. Finally, we demonstrated that green tea, coffee, and cocoa inhibited ACR by trapping ACR to form mono- and di-ACR-TP adducts during the incubation of green tea, coffee, and cocoa with ACR.

Acrolein in cigarette smoke attenuates the innate immune responses mediated by surfactant protein D.

BACKGROUND: Surfactant proteins (SP) A and D belong to collectin family proteins, which play important roles in innate immune response in the lung. We previously demonstrated that cigarette smoke (CS) increases the acrolein modification of SP-A, thereby impairing the innate immune abilities of this protein. In this study, we focused on the effects of CS and its component, acrolein, on the innate immunity role of another collectin, SP-D. METHODS: To determine whether aldehyde directly affects SP-D, we examined the lungs of mice exposed to CS for 1 week and detected aldehyde-modified SP-D using an aldehyde reactive probe. The structural changes in CS extract (CSE) or acrolein-exposed recombinant human (h)SP-D were determined by western blot, liquid chromatography-electrospray ionization tandem mass spectrometry, and blue native-polyacrylamide gel electrophoresis analyses. Innate immune functions of SP-D were determined by bacteria growth and macrophage phagocytosis. RESULTS: Aldehyde-modified SP-D as well as SP-A was detected in the lungs of mice exposed to CS for 1 week. Exposure of hSP-D to CSE or acrolein induced an increased higher-molecular -weight of hSP-D and acrolein induced modification of five lysine residues in hSP-D. These modifications led to disruption of the multimer structure of SP-D and attenuated its ability to inhibit bacterial growth and activate macrophage phagocytosis. CONCLUSION: CS induced acrolein modification in SP-D, which in turn induced structural and functional defects in SP-D. GENERAL SIGNIFICANCE: These results suggest that CS-induced structural and functional defects in SP-D contribute to the dysfunction of innate immune responses in the lung following CS exposure.

Effects of cinnamaldehyde on anti-respiratory syncytial virus: A protocol of systematic review and meta-analysis.

BACKGROUND: Previous reports found that cinnamaldehyde has effects on anti-respiratory syncytial virus (ARSV). However, their results are still contradictory. Therefore, this study will systematically address the effects of cinnamaldehyde on ARSV. METHODS: The following electronic bibliographic databases will be retrieved from their outset to the March 31, 2020: MEDLINE, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Technology Periodical Database, China Biology Medicine, and China National Knowledge Infrastructure. No language and publication time limitations will be exerted in this study. All relevant case-controlled studies or randomized controlled studies exploring the effects of cinnamaldehyde on ARSV will be included. Study quality of case-controlled studies will be assessed by Newcastle-Ottawa scale, and that of randomized controlled studies will be identified by Cochrane risk of bias tool. All data pooling and analysis will be performed using RevMan 5.3 software. RESULTS: This study will summarize the up-to-date high-quality evidence to synthesize outcome data on the effects of cinnamaldehyde on ARSV. CONCLUSION: Findings of this study may provide beneficial evidence for both clinicians and future studies regarding the effects of cinnamaldehyde on ARSV. SYSTEMATIC REVIEW REGISTRATION: INPLASY202040074.

Acrolein contributes to urothelial carcinomas in patients with chronic kidney disease.

BACKGROUND: Urothelial carcinomas (UCs) are highly prevalent in patients with end-stage renal disease. Chronic kidney disease (CKD) is the predecessor of end-stage renal disease, and it is also associated with UC. However, the interplay between CKD and UC lacks solid evidence. Acrolein is produced by polyamines and has been suggested to be the uremic "toxin." The level of acrolein correlates well with chronic renal failure. We recently found that acrolein-induced DNA damage and inhibited DNA repair in urothelial cells, which contribute to bladder cancer. Therefore, we hypothesize that acrolein is involved in the formation of UC in patients with CKD. MATERIALS AND METHODS: A total of 62 UC patients and 43 healthy control subjects were recruited. Acrolein-DNA (Acr-dG) adducts and p53 gene mutations in UC tissues, plasma acrolein-protein conjugates (Acr-PC) and S-(3-hydroxypropyl)-N-acetylcysteine levels, and urinary Acr metabolites were analyzed in these patients. RESULTS: Acr-dG levels were statistically correlated with CKD stages in UC patients (P < 0.01). Most p53 mutations were G to A and G to T mutations in these patients, and 50% of mutations at G:C pairs occurred in CpG sites, which is similar to the mutational spectra induced by Acr-dG adducts. Acr-PC levels in the plasma of UC patients with CKD were significantly higher than those of control subjects (P < 0.001). Altered urinary S-(3-hydroxypropyl)-N-acetylcysteine was also found in UC patients with CKD compared to control subjects (P < 0.005). CONCLUSION: These results indicate that acrolein acts as an endogenous uremic toxin and contributes to UC formation in patients with CKD.

Carbonyl compounds and furan derivatives with toxic potential evaluated in the brewing stages of craft beer.

Carbonyl compounds and furan derivatives may form adducts with DNA and cause oxidative stress to human cells, which establishes the carcinogenic potential of these compounds. The occurrence of these compounds may vary according to the processing characteristics of the beer. The objective of this study was, for the first time, to investigate the free forms of target carbonyl compounds [acetaldehyde, acrolein, ethyl carbamate (EC) and formaldehyde] and furan derivatives [furfural and furfuryl alcohol (FA)] during the brewing stages of ale and lager craft beers. Samples were evaluated using headspace-solid phase microextraction and gas chromatography with mass spectrometric detection in selected ion monitoring mode (HS-SPME-GC/MS-SIM). Acetaldehyde, acrolein, formaldehyde and furfuryl alcohol were found in all brewing stages of both beer types, while EC and furfural concentrations were below the LOD and LOQ of the method (0.1 and 0.01 µg L-1, respectively). Boiling and fermentation of ale brewing seem to be important steps for the formation of acrolein and acetaldehyde, respectively, while boiling resulted in an increase of FA in both types of beer. Conversely, pasteurisation and maturation reduced the levels of these compounds in both types of beer. An increase in concentration of acrolein has not been verified in lager brew probably due to the difference in boiling time between these two types of beer (60 and 90 min for ale and lager, respectively).

Protective effect of Ganoderma atrum polysaccharide on acrolein-induced macrophage injury via autophagy-dependent apoptosis pathway.

The study aimed to investigate the protective effect and underlying mechanism of Ganoderma atrum (G. atrum) polysaccharide (PSG-1) on macrophage injury induced by acrolein. The results showed that PSG-1 restored the cell viability damaged by acrolein. In addition, PSG-1 significantly reduced the acrolein-induced occurrence of apoptosis via increase of Bcl-2 expression, mitochondrial membrane potential (MMP), decrease of ROS, cytochrome c (Cyt-C), caspase-3, caspase-9. Moreover, the overexpressions of autophagy-related proteins (LC3, Beclin-1, Atg7 and Atg5) were suppressed by PSG-1, which demonstrated that PSG-1 inhibited autophagy in acrolein treated macrophage. Beside, PSG-1 significantly elevated the expression level of p-mTOR, suggested that PSG-1 mediated autophagy through mTOR pathway. Furthermore, inhibitor of autophagy could inhibit apoptosis in acrolein-induced macrophage, suggesting that autophagy may be involved in the regulation of apoptosis. In summary, the present study demonstrated that PSG-1 protected acrolein-induced macrophage injury via autophagy-dependent apoptosis.

Acrolein Is Involved in the Synergistic Potential of Cigarette Smoking- and Betel Quid Chewing-Related Human Oral Cancer.

BACKGROUND: Cigarette smoking (CS) and betel quid (BQ) chewing are two known risk factors and have synergistic potential for the development of oral squamous cell carcinoma (OSCC) in Taiwan. The p53 mutation characteristics in OSCC (G to A or G to T mutations) are similar to that of acrolein-induced DNA damage. Acrolein is a major cigarette-related carcinogen that preferentially causes p53 mutations and inhibits DNA repair function in lung cancer. We hypothesize that acrolein is associated with OSCC carcinogenesis. METHODS: A total of 97 patients with OSCC and 230 healthy subjects with CS and/or BQ chewing histories were recruited. Slot blot analysis of Acr-dG adducts, an indicator of acrolein-induced DNA damage in buccal DNA, and LC/MS-MS analysis of 3-HPMA levels, urinary Acr metabolites, were performed. RESULTS: Our results showed that the level of Acr-dG adducts in buccal cells was 1.4-fold higher in patients with OSCC than in healthy subjects with CS and/or BQ chewing histories (P < 0.001). In addition, in healthy subjects, CS and BQ chewing were associated with significantly higher levels of 3-HPMA, indicating that CS and BQ chewing promotes acrolein absorption. However, 3-HPMA levels in patients with OSCC were significantly lower than those in healthy subjects, indicating impaired acrolein metabolism. CONCLUSIONS: In this study, we provide a novel mechanism by which increased acrolein uptake and impaired metabolism may contribute to the synergistic potential of CS and BQ-induced OSCC. IMPACT: Elevated acrolein-induced DNA damage (Acr-dG adducts) detected in buccal swabs may serve as an early indicator to identify patients at risk of developing OSCC.

Claudins, VEGF, Nrf2, Keap1, and Nonspecific Airway Hyper-Reactivity Are Increased in Mice Co-Exposed to Allergen and Acrolein.

Acrolein, an α/ß-unsaturated aldehyde, is volatile at room temperature. It is a respiratory irritant found in environmental tobacco smoke, which can be generated during cooking or endogenously at sites of injury. An acute high concentration of uncontrolled irritant exposure can lead to an asthma-like syndrome known as reactive airways dysfunction syndrome (RADS). However, whether acrolein can induce RADS remains poorly understood. The aim of study is to develop a RADS model of acrolein inhalation in mice and to clarify the mechanism of RADS. Mice were treated with ovalbumin (OVA) and exposed to acrolein (5 ppm/10 min). Airway hyper-responsiveness (AHR) was measured on days 24 and 56, and samples were collected on days 25 and 57. Tight junction protein, antioxidant-associated protein, and vascular endothelial growth factor (VEGF) levels were estimated by Western blotting and immunohistochemical staining. Reactive oxygen species (ROS) was calculated using enzyme linked immunosorbent assays. Acrolein or OVA groups exhibited an increase in airway inflammatory cells and AHR compared to a sham group. These effects were further increased in mice in the OVA + acrolein exposure group than in the OVA exposure group and persisted in the acrolein exposure group for 8 weeks. CLDNs, carbonyls, VEGF, Nrf2, and Keap1 were observed in the lungs. Our data demonstrate that acrolein induces RADS and that ROS, angiogenesis, and tight junction proteins are involved in RADS in a mouse model.

Longitudinal stability in cigarette smokers of urinary biomarkers of exposure to the toxicants acrylonitrile and acrolein.

The urinary metabolites cyanoethyl mercapturic acid (CEMA) and 3-hydroxypropyl mercapturic acid (3-HPMA) have been widely used as biomarkers of exposure to acrylonitrile and acrolein, respectively, but there are no published data on their consistency over time in the urine of cigarette smokers. We provided, free of charge over a 20 week period, Spectrum NRC600/601 research cigarettes to cigarette smokers in the control arm of a randomized clinical trial of the reduced nicotine cigarette. Urine samples were collected at weeks 4, 8, 12, 16, and 20 and analyzed for CEMA and 3-HPMA, and total nicotine equivalents (TNE) using validated methods. Creatinine-corrected intra-class correlation coefficients for CEMA, 3-HPMA, and TNE were 0.67, 0.46, and 0.68, respectively, indicating good longitudinal consistency for CEMA, while that of 3-HPMA was fair. A strong correlation between CEMA and TNE values was observed. These data support the use of CEMA as a reliable biomarker of tobacco smoke exposure. This is the first report of the longitudinal stability of the biomarkers of acrylonitrile and acrolein exposure in smokers. The data indicate that CEMA, the biomarker of acrylonitrile exposure, is consistent over time in cigarette smokers, supporting its use. While 3-HPMA levels were less stable over time, this biomarker is nevertheless a useful monitor of human acrolein exposure because of its specificity to this toxicant.

Subacute acrolein exposure to rat larynx in vivo.

OBJECTIVES/HYPOTHESIS: Inhaled pollutants can contact vocal fold tissue and induce detrimental voice changes. Acrolein is a pollutant in cigarette smoke and can also be inhaled during the combustion of fossil fuels, animal fats, and plastics in the environment. However, the vocal fold pathological changes induced by acrolein and the underlying inflammatory pathways are not well understood. These biologic data are needed to understand why voice problems may result from pollutant exposure. STUDY DESIGN: In vivo prospective design with experimental and control groups. METHODS: Sprague-Dawley male rats (N = 36) were exposed to acrolein (3 ppm) or filtered air (control) through a whole-body exposure system for 5 hours/day, for 5 days/week, over 4 weeks. Histopathological changes, presence of edema, expression of proinflammatory cytokines and markers, and the phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were investigated. RESULTS: Histological evaluation and quantification demonstrated that subacute acrolein exposure induced significant vocal fold edema. Acrolein exposure also induced epithelial sloughing and cell death. Quantitative polymerase chain reaction showed a significant upregulation of genes encoding interferon regulatory factor and chitinase-3-like protein 3. Western blot revealed a 76.8% increase in phosphorylation of NF-κB P65 after subacute acrolein exposure. CONCLUSIONS: These findings suggest that 4-week exposures to 3 ppm acrolein induce vocal fold inflammation manifested as edema, related to the activation of NF-κB signaling. The edema may underlie the voice changes reported in speakers exposed to pollutants. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E313-E317, 2019.

Does cyclophosphamide still play a role in glomerular diseases?

Cyclophosphamide is a prodrug that is converted to inactive carboxy-cyclophosphamide, acrolein and phosphoramide mustard, an agent that adds alkyl groups to oxygen and nitrogen atoms of guanine, one of the four nitrogen bases that form the DNA nucleotides, causing DNA cross-links and introducing DNA breaks. These cytotoxic and mutagenic effects mainly occur in proliferating cells. Repair mechanisms may prevent DNA damage in quiescent cells, but they may be insufficient to contrast the side effects of cyclophosphamide if high doses of the drug are used. Most adverse events are dose- and age-dependent. Phosphoramide mustard can cause bone marrow toxicity, gonadal toxicity, and may favor the development of leukemia, bladder cancer and other types of malignancy. Acrolein can produce hemorrhagic cystitis and even bladder fibrosis when given for prolonged periods. A number of precautional measures should be taken to prevent these untoward events. In particular, long-term administration and high doses of cyclophosphamide should be avoided whenever possible. Today the indications to cyclophosphamide in glomerular diseases are more restricted than in the past, but the drug is still used as a steroid-sparing agent in steroid-sensitive minimal change disease and focal segmental glomerulosclerosis. In membranous nephropathy, cyclophosphamide, alternated or associated with corticosteroids, proved to be beneficial in obtaining remission of nephrotic syndrome and preserving renal function. Cyclophosphamide is considered as a first-line treatment for rapidly progressive glomerulonephritis and the hectic phases of lupus nephritis. In conclusion, cyclophosphamide is a cheap drug that may be useful in a number of glomerular diseases but it may lead to severe side effects. A close monitoring of blood count and clinical conditions, as well as low cumulative doses of cyclophosphamide are strongly recommended when using the drug in patients with renal diseases.

Analytical and toxicological evaluation of flavor chemicals in electronic cigarette refill fluids.

Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing authentic standards of each flavor chemical and analyzed the toxicity of their aerosols produced at 3V and 5V using a tank Box Mod device. Over 50% of the refill fluids in our sample contained high concentrations of flavor chemicals that transferred efficiently to aerosols at concentrations that produce cytotoxicity. When tested with two types of human lung cells, the aerosols made at 5V were generally more toxic than those made at 3V. These data will be valuable for consumers, physicians, public health officials, and regulatory agencies when discussing potential health concerns relating to flavor chemicals in electronic cigarette products.

[The impact of electronic cigarettes usage on the endothelial function and the progression of atherosclerosis]. / Wplyw uzywania papierosów elektronicznych na funkcje sródblonka naczyniowego oraz rozwój miazdzycy.

The exponetial growth in popularity of electronic cigarettes in the world markets intensifies the debate about their health effects. The smoking of traditional tabacoo products is a factor associated with the endothelium damage and progression of atherosclerosis. The elimination of the combustion process in electronic cigarettes allows to conclude that they are less harmful to a vascular endothelium than traditional tobacco products. E-cigarette aerosol contains many compounds that have an influence on initiation and progression of atherosclerosis. Nicotine protherogenic action is not fully explained. On one hand, nicotine modifies metabolic pathways leading to atherosclerosis, whereas epidemiological studies do not show an increased risk of cardiovascular disease in the population using nicotine replacement therapy or snuff. Acrolein, formaldehyde and the ultrafine particles generated during e-liquid heating have an impact on initiation and progression of atherosclerosis, but their level is lower than that of tobacco smoke. In order to assess accurately the longterm effects of e-cigarettes, it is necessary to conduct epidemiological studies measuring the effects of using e-cigarettes. It is claimed that the use of electronic cigarettes has a potential impact on the development of atherosclerosis, but is significantly lower than that of traditional cigarettes.