Spinal histamine H4 receptor mediates chronic pruritus via p-ERK in acetone-ether-water (AEW)-induced dry skin mice.

Dry skin is common to many pruritic diseases and is difficult to improve with oral traditional antihistamines. Recently, increasing evidence indicated that histamine H4 receptor (H4R) plays an important role in the occurrence and development of pruritus. Extracellular signal-regulated kinase (ERK) phosphorylation activation in the spinal cord mediates histamine-induced acute and choric itch. However, whether the histamine H4 receptor regulates ERK activation in the dry skin itch remains unclear. In the study, we explore the role of the histamine H4 receptor and p-ERK in the spinal cord in a dry skin mouse model induced by acetone-ether-water (AEW). q-PCR, Western blot, pharmacology and immunofluorescence  were applied in the study. We established a dry skin itch model by repeated application of AEW on the nape of neck in mice. The AEW mice showed typically dry skin histological change and persistent spontaneous scratching behaviour. Histamine H4 receptor, instead of histamine H1 receptor, mediated spontaneous scratching behaviour in AEW mice. Moreover, c-Fos and p-ERK expression in the spinal cord neurons were increased and co-labelled with GRPR-positive neurons in AEW mice. Furthermore, H4R agonist 4-methyhistamine dihydrochloride (4-MH)induced itch. Both 4-MH-induced itch and the spontaneous itch in AEW mice were blocked by p-ERK inhibitor U0126. Finally, intrathecal H4R receptor antagonist JNJ7777120 inhibited spinal p-ERK expression in AEW mice. Our results indicated that spinal H4R mediates itch via ERK activation in the AEW-induced dry skin mice.

3D printer emissions elicit filament-specific and dose-dependent metabolic and genotoxic effects in human airway epithelial cells.

Three-dimensional (3D) printers have become popular educational tools in secondary and post-secondary STEM curriculum; however, concerns have emerged regarding inhalation exposures and associated health risks. Current evidence suggests that filament materials and site conditions may cause differences in the chemical profiles and toxicological properties of 3D printer emissions; however, few studies have evaluated exposures directly in the classroom. In this study, we monitored and sampled particulate matter (PM) emitted from acrylonitrile-butadiene-styrene (ABS) and polylactic acid (PLA) filaments during a 3-hour 3D printing session in a high school classroom using aerosol monitoring instrumentation and collection media. To evaluate potential inhalation risks, Multiple Path Particle Dosimetry (MPPD) modeling was used to estimate inhaled doses and calculate in vitro concentrations based on the observed aerosol data and specific lung and breathing characteristics. Dynamic light scattering was used to evaluate the hydrodynamic diameter, zeta potential, and polydispersity index (PDI) of extracted PM emissions dispersed in cell culture media. Small airway epithelial cells (SAEC) were employed to determine cellular viability, genotoxic, inflammatory, and metabolic responses to each emission exposure using MTS, ELISA, and high-performance liquid chromatography-mass spectrometry (HPLC-MS), respectively. Aerosol monitoring data revealed that emissions from ABS and PLA filaments generated similar PM concentrations within the ultrafine and fine ranges. However, DLS analysis showed differences in the physicochemical properties of ABS and PLA PM, where the hydrodynamic diameter of PLA PM was greater than ABS PM, which may have influenced particle deposition rates and cellular outcomes. While exposure to both ABS and PLA PM reduced cell viability and induced MDM2, an indicator of genomic instability, PLA PM alone increased gamma-H2AX, a marker of double-stranded DNA breaks. ABS and PLA emissions also increased the release of pro-inflammatory cytokines, although this did not reach significance. Furthermore, metabolic profiling via high performance liquid chromatography-mass spectrometry (HPLC-MS) and subsequent pathway analysis revealed filament and dose dependent cellular metabolic alterations. Notably, our metabolomic analysis also revealed key metabolites and pathways implicated in PM-induced oxidative stress, DNA damage, and respiratory disease that were perturbed across both tested doses for a given filament. Taken together, these findings suggest that use of ABS and PLA filaments in 3D printers within school settings may potentially contribute to adverse respiratory responses especially in vulnerable populations.

Effects of aluminum (Al) stress on the isoprenoid metabolism of two Citrus species differing in Al-tolerance.

Isoprenoid metabolism and its derivatives took part in photosynthesis, growth regulation, signal transduction, and plant defense to biotic and abiotic stresses. However, how aluminum (Al) stress affects the isoprenoid metabolism and whether isoprenoid metabolism plays a vital role in the Citrus plants in coping with Al stress remain unclear. In this study, we reported that Al-treatment-induced alternation in the volatilization rate of monoterpenes (α-pinene, ß-pinene, limonene, α-terpinene, γ-terpinene and 3-carene) and isoprene were different between Citrus sinensis (Al-tolerant) and C. grandis (Al-sensitive) leaves. The Al-induced decrease of CO2 assimilation, maximum quantum yield of primary PSII photochemistry (Fv/Fm), the lower contents of glucose and starch, and the lowered activities of enzymes involved in the mevalonic acid (MVA) pathway and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway might account for the different volatilization rate of isoprenoids. Furthermore, the altered transcript levels of genes related to isoprenoid precursors and/or derivatives metabolism, such as geranyl diphosphate (GPP) synthase (GPPS) in GPP biosynthesis, geranylgeranyl diphosphate synthase (GGPPS), chlorophyll synthase (CHS) and GGPP reductase (GGPPR) in chlorophyll biosynthesis, limonene synthase (LS) and α-pinene synthase (APS) in limonene and α-pinene synthesis, respectively, might be responsible for the different contents of corresponding products in C. grandis and C. sinensis. Our data suggested that isoprenoid metabolism was involved in Al tolerance response in Citrus, and the alternation of some branches of isoprenoid metabolism could confer different Al-tolerance to Citrus species.

Erk Inhibition as a Promising Therapeutic Strategy for High IL-8-Secreting and Low SPTAN1-Expressing Colorectal Cancer.

Tumor recurrence and drug resistance are responsible for poor prognosis in colorectal cancer (CRC). DNA mismatch repair (MMR) deficiency or elevated interleukin-8 (IL-8) levels are characteristics of CRCs, which have been independently correlated with treatment resistance to common therapies. We recently demonstrated significantly impaired therapeutical response and increased IL-8 release of CRC cell lines with reduced expression of MMR protein MLH1 as well as cytoskeletal non-erythrocytic spectrin alpha II (SPTAN1). In the present study, decreased intratumoral MLH1 and SPTAN1 expression in CRCs could be significantly correlated with enhanced serum IL-8. Furthermore, using stably reduced SPTAN1-expressing SW480, SW620 or HT-29 cell lines, the RAS-mediated RAF/MEK/ERK pathway was analyzed. Here, a close connection between low SPTAN1 expression, increased IL-8 secretion, enhanced extracellular-signal-regulated kinase (ERK) phosphorylation and a mesenchymal phenotype were detected. The inhibition of ERK by U0126 led to a significant reduction in IL-8 secretion, and the combination therapy of U0126 with FOLFOX optimizes the response of corresponding cancer cell lines. Therefore, we hypothesize that the combination therapy of FOLFOX and U0126 may have great potential to improve drug efficacy on this subgroup of CRCs, showing decreased MLH1 and SPTAN1 accompanied with high serum IL-8 in affected patients.

Higher exposure to 1,3-butadiene is associated with more severe hearing loss.

While volatile organic compounds (VOCs) impair various organs, their influence on hearing loss (HL) has not been extensively researched. We aimed to identify the association between VOCs and HL or high-frequency hearing loss (HFHL). We extracted data on age, sex, pure tone audiometry, hypertension, occupational noise exposure, and creatinine-corrected urine VOC metabolite concentrations from the eighth Korea National Health and Nutrition Survey. Among the VOC metabolites, N-acetyl-S-(benzyl)-L-cysteine (BMA, P = 0.004), N-acetyl-S-(phenyl)-L-cysteine (SPMA, P = 0.027), and N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA, P < 0.001) showed associations with HL. Additionally, HFHL exhibited significant associations with BMA (P = 0.005), 3- and 4-methylhippuric acid (3, 4 MHA, P = 0.049), mandelic acid (MA, P = 0.015), SPMA (P < 0.001), N-acetyl-S-(3-hydroxypropyl)-L-cysteine (3-HPMA, P < 0.001), and DHBMA (P < 0.001). After controlling other factors, DHBMA were associated with HL (P = 0.021) and HFHL (P = 0.014) and exhibited a linear association with the mean hearing level (ß = 0.054, P = 0.024) and high-frequency hearing level (ß = 0.045, P = 0.037). Since 1,3-butadiene may act as an ototoxic material, early screening for workers exposed to 1,3-butadiene and reducing exposure to 1,3-butadiene in everyday life may be helpful to prevent further HL.

Endogenous oncogenic KRAS expression increases cell proliferation and motility in near-diploid hTERT RPE-1 cells.

About 18% of all human cancers carry a mutation in the KRAS gene making it among the most sought-after anticancer targets. However, mutant KRas protein has proved remarkably undruggable. The recent approval of the first generation of RAS inhibitors therefore marks a seminal milestone in the history of cancer research. It also raises the predictable challenges of limited drug efficacies and acquired resistance. Hence, new approaches that improve our understanding of the tumorigenic mechanisms of oncogenic RAS within more physiological settings continue to be essential. Here, we have used the near-diploid hTERT RPE-1 cells to generate isogenic cell lines in which one of the endogenous KRAS alleles carries an oncogenic KRAS mutation at glycine 12. Cells with a KRASG12V/+, KRASG12C/+, or KRASG12D/+ genotype, together with WT KRASG12G(WT)/+ cells, reveal that oncogenic KRAS.G12X mutations increase cell proliferation rate and cell motility and reduced focal adhesions in KRASG12V/+ cells. Epidermal growth factor -induced phosphorylation of ERK and AKT was comparable between KRASG12V/+, KRASG12C/+, KRASG12D/+, and KRASG12G(WT)/+ cells. Interestingly, KRASG12X/+ cells showed varying responses to distinct inhibitors with the KRASG12V/+ and KRASG12D/+ cells more sensitive to hydroxyurea and MEK inhibitors, U0126 and trametinib, but more resistant to PI3K inhibitor, PIK-90, than the KRASG12G(WT)/+ cells. A combination of low doses of hydroxyurea and U0126 showed an additive inhibition on growth rate that was greater in KRASG12V/+ than WT cells. Collectively, these cell lines will be a valuable resource for studying oncogenic RAS signaling and developing effective anti-KRAS reagents with minimum cytotoxicity on WT cells.

Monomer-Recyclable Polyester from CO2 and 1,3-Butadiene.

Synthesis of monomer-recyclable polyesters solely from CO2 and bulk olefins holds great potential in significantly reducing CO2 emissions and addressing the issue of plastic pollution. Due to the kinetic disadvantage of direct copolymerization of CO2 and bulk olefins compared to homopolymerization of bulk olefins, considerable research attention has been devoted to synthesis of polyester via the ring-opening polymerization (ROP) of a six-membered disubstituted lactone intermediate, 1,2-ethylidene-6-vinyl-tetrahydro-2H-pyran-2-one (𝜹-L), obtained from telomerization of CO2 and 1,3-butadiene. However, the conjugate olefin on the six-membered ring of 𝜹-L leads to serious Michael addition side reactions. Thus, the selective ROP of 𝜹-L, which can precisely control the repeating unit for the production of polyesters potentially amenable to efficient monomer recycling, remains an unresolved challenge. Herein, the first example of selective ROP of 𝜹-L is reported using a combination of organobase and N,N'-Bis[3,5-bis(trifluoromethyl)phenyl]urea as the catalytic system. Systematic modifications of the substituent of the urea show that the presence of electron-deficient 3,5-bis(trifluoromethyl)-phenyl groups is the key to the extraordinary selectivity of ring opening over Michael addition. Efficient monomer recovery of oligo(𝜹-L) is also achieved under mild catalytic conditions.

Ribosomal S6 kinase 2-forkhead box protein O4 signaling pathway plays an essential role in melanogenesis.

Although previous studies have examined the signaling pathway involved in melanogenesis through which ultraviolet (UV) or α-melanocyte-stimulating hormones (α-MSH) stimuli act as key inducers to produce melanin at the stratum basal layer of the epidermis, the signaling pathway regulating melanogenesis is still controversial. This study reports that α-MSH, not UVA and UVB, acted as a major stimulus of melanogenesis in B16F10 melanoma cells. Signaling pathway analysis using gene knockdown technology and chemical inhibitors, the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)/p90 ribosomal S6 kinase 2 (RSK2) played an important role in melanogenesis. Unexpectedly, LY294002, a PI3K inhibitor, increased melanogenesis without UV or α-MSH stimulation, suggesting that the PI3K/AKT signaling pathway may not be a major signaling pathway for melanogenesis. Chemical inhibition of the MEKs/ERKs/RSK2 signaling pathway using U0126 or BI-D1870 suppressed melanogenesis by stimulation of UVA or α-MSH stimulation, or both. In particular, the genetic depletion of RSK2 or constitutive active (CA)-RSK2 overexpression showed that RSK2 plays a key role in melanogenesis. Interestingly, forkhead box protein O4 (FOXO4) was phosphorylated by RSK2, resulting in the increase of FOXO4's transactivation activity. Notably, the FOXO4 mutant harboring serine-to-alanine replacement at the phosphorylation sites totally abrogated the transactivation activity and reduced melanin production, indicating that RSK2-mediated FOXO4 activity plays a key role in melanogenesis. Furthermore, kaempferol, a flavonoid inhibiting the RSK2 activity, suppressed melanogenesis. In addition, FOXO4-wt overexpression showed that FOXO4 enhance melanin synthesis. Overall, the RSK2-FOXO4 signaling pathway plays a key role in modulating melanogenesis.

Exposure to volatile organic compounds and mortality in US adults: A population-based prospective cohort study.

Volatile organic compounds (VOCs) are ubiquitous in both indoor and outdoor environments. Evidence on the associations of individual and joint VOC exposure with all-cause and cause-specific mortality is limited. Measurements of 15 urinary VOC metabolites were available to estimate exposure to 12 VOCs in the National Health and Nutritional Examination Survey (NHANES) 2005-2006 and 2011-2018. The environment risk score (ERS) was calculated using LASSO regression to reflect joint exposure to VOCs. Follow-up data on death were obtained from the NHANES Public-Use Linked Mortality File through December 31, 2019. Cox proportional hazard models and restricted cubic spline models were applied to evaluate the associations of individual and joint VOC exposures with all-cause and cause-specific mortality. Population attributable fractions were calculated to assess the death burden attributable to VOC exposure. During a median follow-up of 6.17 years, 734 (8.34 %) deaths occurred among 8799 adults. Urinary metabolites of acrolein, acrylonitrile, 1,3-butadiene, and ethylbenzene/styrene were significantly associated with all-cause, cardiovascular disease (CVD), respiratory disease (RD), and cancer mortality in a linear dose-response manner. Linear and robust dose-response relationships were also observed between ERS and all-cause and cause-specific mortality. Each 1-unit increase in ERS was associated with a 33.6 %, 39.1 %, 109.8 %, and 67.8 % increase for all-cause, CVD, RD, and cancer mortality risk, respectively. Moreover, joint exposure to VOCs contributed to 17.95 % of all-cause deaths, 13.49 % of CVD deaths, 35.65 % of RD deaths, and 33.85 % of cancer deaths. Individual and joint exposure to VOCs may enhance the risk of all-cause and cause-specific mortality. Reducing exposure to VOCs may alleviate the all-cause and cause-specific death burden.

Multi-Institutional Audit of FLASH and Conventional Dosimetry With a 3D Printed Anatomically Realistic Mouse Phantom.

PURPOSE: We conducted a multi-institutional dosimetric audit between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3-dimensional (3D) printed mouse phantom. METHODS AND MATERIALS: A computed tomography (CT) scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene (∼1.02 g/cm3) and polylactic acid (∼1.24 g/cm3) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid (∼0.64 g/cm3). Hounsfield units (HU), densities, and print-to-print stability of the phantoms were assessed. Three institutions were each provided a phantom and each institution performed 2 replicates of irradiations at selected anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. RESULTS: Compared with the reference CT scan, CT scans of the phantom demonstrated mass density differences of 0.10 g/cm3 for bone, 0.12 g/cm3 for lung, and 0.03 g/cm3 for soft tissue regions. Differences in HU between phantoms were <10 HU for soft tissue and bone, with lung showing the most variation (54 HU), but with minimal effect on dose distribution (<0.5%). Mean differences between FLASH and CONV decreased from the first to the second replicate (4.3%-1.2%), and differences from the prescribed dose decreased for both CONV (3.6%-2.5%) and FLASH (6.4%-2.7%). Total dose accuracy suggests consistent pulse dose and pulse number, although these were not specifically assessed. Positioning variability was observed, likely due to the absence of robust positioning aids or image guidance. CONCLUSIONS: This study marks the first dosimetric audit for FLASH using a nonhomogeneous phantom, challenging conventional calibration practices reliant on homogeneous phantoms. The comparison protocol offers a framework for credentialing multi-institutional studies in FLASH preclinical research to enhance reproducibility of biologic findings.

Quantifying exhaled acetone and isoprene through solid phase microextraction and gas chromatography-mass spectrometry.

BACKGROUND: Acetone, isoprene, and other volatile organic compounds (VOCs) in exhaled breath have been shown to be biomarkers for many medical conditions. Researchers use different techniques for VOC detection, including solid phase microextraction (SPME), to preconcentrate volatile analytes prior to instrumental analysis by gas chromatography-mass spectrometry (GC-MS). These techniques include a previously developed method to detect VOCs in breath directly using SPME, but it is uncommon for studies to quantify exhaled volatiles because it can be time consuming due to the need of many external/internal standards, and there is no standardized or widely accepted method. The objective of this study was to develop an accessible method to quantify acetone and isoprene in breath by SPME GC-MS. RESULTS: A system was developed to mimic human exhalation and expose VOCs to a SPME fiber in the gas phase at known concentrations. VOCs were bubbled/diluted with dry air at a fixed flow rate, duration, and volume that was comparable to a previously developed breath sampling method. Identification of acetone and isoprene through GC-MS was verified using standards and observing overlaps in chromatographic retention/mass spectral fragmentation. Calibration curves were developed for these two analytes, which showed a high degree of linear correlation. Acetone and isoprene displayed limits of detection/quantification equal to 12 ppb/37 ppb and 73 ppb/222 ppb respectively. Quantification results in healthy breath samples (n = 15) showed acetone concentrations spanned between 71 ppb and 294 ppb, and isoprene varied between 170 ppb and 990 ppb. Both concentration ranges for acetone and isoprene in this study overlap with those reported in existing literature. SIGNIFICANCE: Results indicate the development of a system to quantify acetone and isoprene in breath that can be adapted to diverse sampling methods and instrumental analyses beyond SPME GC-MS.

Study of sequential abiotic and biotic degradation of styrene butadiene rubber.

Styrene butadiene rubber is one of the main constituents of tire tread. During tire life, the tread material undergoes different stresses that impact its structure and chemical composition. Wear particles are then released into the environment as weathered material. To understand their fate, it is important to start with a better characterization of abiotic and biotic degradation of the elastomer material. A multi-disciplinary approach was implemented to study the photo- and thermo- degradation of non-vulcanized SBR films containing 15 w% styrene as well as their potential biodegradation by Rhodoccocus ruber and Gordonia polyisoprenivorans bacterial strains. Each ageing process leads to crosslinking reactions, much surface oxidation of the films and the production of hundreds of short chain compounds. These degradation products present a high level of unsaturation and oxidation and can be released into water to become potential substrates for microorganisms. Both strains were able to degrade from 0.2 to 1.2 % (% ThOD) of the aged SBR film after 30-day incubation while no biodegradation was observed on the pristine material. A 25-75 % decrease in the signal intensity of water extractable compounds was observed, suggesting that biomass production was linked to the consumption of low-molecular-weight degradation products. These results evidence the positive impact of abiotic degradation on the biodegradation process of styrene butadiene rubber.

NEDD4L is a promoter for angiogenesis and cell proliferation in human umbilical vein endothelial cells.

Dysregulated angiogenesis leads to neovascularization, which can promote or exacerbate various diseases. Previous studies have proved that NEDD4L plays an important role in hypertension and atherosclerosis. Hence, we hypothesized that NEDD4L may be a critical regulator of endothelial cell (EC) function. This study aimed to define the role of NEDD4L in regulating EC angiogenesis and elucidate their underlying mechanisms. Loss- and gain-of-function of NEDD4L detected the angiogenesis and mobility role in human umbilical vein endothelial cells (HUVECs) using Matrigel tube formation assay, cell proliferation and migration. Pharmacological pathway inhibitors and western blot were used to determine the underlying mechanism of NEDD4L-regulated endothelial functions. Knockdown of NEDD4L suppressed tube formation, cell proliferation and cell migration in HUVECs, whereas NEDD4L overexpression promoted these functions. Moreover, NEDD4L-regulated angiogenesis and cell progression are associated with the phosphorylation of Akt, Erk1/2 and eNOS and the expression of VEGFR2 and cyclin D1 and D3. Mechanically, further evidence was confirmed by using Akt blocker MK-2206, Erk1/2 blocker U0126 and eNOS blocker L-NAME. Overexpression NEDD4L-promoted angiogenesis, cell migration and cell proliferation were restrained by these inhibitors. In addition, overexpression NEDD4L-promoted cell cycle-related proteins cyclin D1 and D3 were also suppressed by Akt blocker MK-2206, Erk1/2 blocker U0126 and eNOS blocker L-NAME. Our results demonstrated a novel finding that NEDD4L promotes angiogenesis and cell progression by regulating the Akt/Erk/eNOS pathways.

Mesenchymal stem cells alleviate sepsis-induced acute lung injury by blocking neutrophil extracellular traps formation and inhibiting ferroptosis in rats.

Acute lung injury (ALI) is one of the most serious complications of sepsis, characterized by high morbidity and mortality rates. Ferroptosis has recently been reported to play an essential role in sepsis-induced ALI. Excessive neutrophil extracellular traps (NETs) formation induces exacerbated inflammation and is crucial to the development of ALI. In this study, we explored the effects of ferroptosis and NETs and observed the therapeutic function of mesenchymal stem cells (MSCs) on sepsis-induced ALI. First, we produced a cecal ligation and puncture (CLP) model of sepsis in rats. Ferrostain-1 and DNase-1 were used to inhibit ferroptosis and NETs formation separately, to confirm their effects on sepsis-induced ALI. Next, U0126 was applied to suppress the MEK/ERK signaling pathway, which is considered to be vital to NETs formation. Finally, the therapeutic effect of MSCs was observed on CLP models. The results demonstrated that both ferrostain-1 and DNase-1 application could improve sepsis-induced ALI. DNase-1 inhibited ferroptosis significantly in lung tissues, showing that ferroptosis could be regulated by NETs formation. With the inhibition of the MEK/ERK signaling pathway by U0126, NETs formation and ferroptosis in lung tissues were both reduced, and sepsis-induced ALI was improved. MSCs also had a similar protective effect against sepsis-induced ALI, not only inhibiting MEK/ERK signaling pathway-mediated NETs formation, but also alleviating ferroptosis in lung tissues. We concluded that MSCs could protect against sepsis-induced ALI by suppressing NETs formation and ferroptosis in lung tissues. In this study, we found that NETs formation and ferroptosis were both potential therapeutic targets for the treatment of sepsis-induced ALI, and provided new evidence supporting the clinical application of MSCs in sepsis-induced ALI treatment.

Association of Urinary N7-(1-hydroxyl-3-buten-1-yl) Guanine (EB-GII) Adducts and Butadiene-Mercapturic Acids with Lung Cancer Development in Cigarette Smokers.

Approximately 10% of smokers will develop lung cancer. Sensitive predictive biomarkers are needed to identify susceptible individuals. 1,3-Butadiene (BD) is among the most abundant tobacco smoke carcinogens. BD is metabolically activated to 3,4-epoxy-1-butene (EB), which is detoxified via the glutathione conjugation/mercapturic acid pathway to form monohydroxybutenyl mercapturic acid (MHBMA) and dihydroxybutyl mercapturic acid (DHBMA). Alternatively, EB can react with guanine nucleobases of DNA to form N7-(1-hydroxyl-3-buten-1-yl) guanine (EB-GII) adducts. We employed isotope dilution LC/ESI-HRMS/MS methodologies to quantify MHBMA, DHBMA, and EB-GII in urine of smokers who developed lung cancer (N = 260) and matched smoking controls (N = 259) from the Southern Community Cohort (white and African American). The concentrations of all three biomarkers were significantly higher in smokers that subsequently developed lung cancer as compared to matched smoker controls after adjusting for age, sex, and race/ethnicity (p < 0.0001 for EB-GII, p < 0.0001 for MHBMA, and p = 0.0007 for DHBMA). The odds ratio (OR) for lung cancer development was 1.63 for MHBMA, 1.37 for DHBMA, and 1.97 for EB-GII, with a higher OR in African American subjects than in whites. The association of urinary EB-GII, MHBMA, and DHBMA with lung cancer status did not remain upon adjustment for total nicotine equivalents. These findings reveal that urinary MHBMA, DHBMA, and EB-GII are directly correlated with the BD dose delivered via smoking and are associated with lung cancer risk.

Extraction of volatile organic compounds liberated upon filament extrusion by 3D pen and its comparison with a desktop 3D printer using solid-phase microextraction fiber and Arrow.

Desktop 3D printers that operate by the fused deposition modeling (FDM) mechanism are known to release numerous hazardous volatile organic compounds (VOCs) during printing, including some with potential carcinogenic effects. Operating in a similar manner to FDM 3D printers, 3D pens have gained popularity recently from their ability to allow users to effortlessly draw in the air or create various 3D printed shapes while handling the device like a pen. In contrast to numerous modern 3D printers, 3D pens lack their own ventilation systems and are often used in settings with minimum airflow. Their operation makes users more vulnerable to VOC emissions, as the released VOCs are likely to be in the breathing zone. Consequently, monitoring VOCs released during the use of 3D pens is crucial. In this study, VOCs liberated while extruding acrylonitrile butadiene styrene (ABS) filaments from a 3D pen were measured by solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS). SPME was investigated using the traditional fiber and Arrow geometries with the DVB/Carbon WR/PDMS sorbent while four different brands of ABS filaments-Amazon Basics, Gizmodork, Mynt 3D, and Novamaker-were used with the 3D pen. Heatmap analysis showed differentiation among these brands based on the liberated VOCs. The nozzle temperature and printing speed were found to affect the number and amount of released VOCs. This study goes a step further and presents for the first time a comparison between 3D pen and a desktop 3D printer based on liberated VOCs. Interestingly, the findings reveal that the 3D pen releases a greater number and amount of VOCs compared to the printer. The amounts of liberated VOCs, as indicated by the corresponding chromatographic peak areas, were found to be 1.4 to 62.6 times higher for the 3D pen compared to the 3D printer when using SPME Arrow.

Blockade of vasoactive intestinal peptide receptor 2 (VIPR2) signaling suppresses cyclin D1-dependent cell-cycle progression in MCF-7 cells.

Vasoactive intestinal peptide (VIP) receptor 2 (VIPR2) is a G protein-coupled receptor that binds to Gαs, Gαi, and Gαq proteins to regulate various downstream signaling molecules, such as protein kinase A (PKA), phosphatidylinositol 3-kinase (PI3K), and phospholipase C. In this study, we examined the role of VIPR2 in cell cycle progression. KS-133, a newly developed VIPR2-selective antagonist peptide, attenuated VIP-induced cell proliferation in MCF-7 cells. The percentage of cells in the S-M phase was decreased in MCF-7 cells treated with KS-133. KS-133 in the presence of VIP decreased the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and glycogen synthase kinase-3ß (GSK3ß), resulting in a decrease in cyclin D1 levels. In MCF-7 cells stably-expressing VIPR2, KS-133 decreased PI3K activity and cAMP levels. Treatment with the ERK-specific kinase (MEK) inhibitor U0126 and the class I PI3K inhibitor ZSTK474 decreased the percentage of cells in the S phase. KS-133 reduced the percentage of cells in the S phase more than treatment with U0126 or ZSTK474 alone and did not affect the effect of the mixture of these inhibitors. Our findings suggest that VIPR2 signaling regulates cyclin D1 levels through the cAMP/PKA/ERK and PI3K/AKT/GSK3ß pathways, and mediates the G1/S transition to control cell proliferation.

Mode of action exploration of reproductive toxicity induced by bisphenol S using human normal ovarian epithelial cells through ERß-MAPK signaling pathway.

BACKGROUND: In the plastics production sector, bisphenol S (BPS) has gained popularity as a replacement for bisphenol A (BPA). However, the mode of action (MOA) of female reproductive toxicity caused by BPS remains unclear and the safety of BPS is controversial. METHODS: Human normal ovarian epithelial cell line, IOSE80, were exposed to BPS at human-relevant levels for short-term exposure at 24 h or 48 h, or for long-term exposure at 28 days, either alone or together with five signaling pathway inhibitors: ICI 18,2780 (estrogen receptor [ER] antagonist), G15 (GPR30 specific inhibitor), U0126 (extracellular regulated protein kinase [ERK] 1/2 inhibitor), SP600125 (c-Jun N-terminal kinase [JNK] inhibitor) or SB203580 (p38 mitogen­activated protein kinase [p38MAPK] inhibitor). MOA through ERß-MAPK signaling pathway interruption was explored, and potential thresholds were estimated by the benchmark dose method. RESULTS: For short-term exposure, BPS exposure at human-relevant levels elevated the ESR2 and MAPK8 mRNA levels, along with the percentage of the G0/G1 phase. For long-term exposure, BPS raised the MAPK1 and EGFR mRNA levels, the ERß, p-ERK, and p-JNK protein levels, and the percentage of the G0/G1 phase, which was partly suppressed by U0126. The benchmark dose lower confidence limit (BMDL) of the percentage of the S phase after 24 h exposure was the lowest among all the BMDLs of a good fit, with BMDL5 of 9.55 µM. CONCLUSIONS: The MOA of female reproductive toxicity caused by BPS at human-relevant levels might involve: molecular initiating event (MIE)-BPS binding to ERß receptor, key event (KE)1-the interrupted expression of GnRH, KE2-the activation of JNK (for short-term exposure) and ERK pathway (for long-term exposure), KE3-cell cycle arrest (the increased percentage of the G0/G1 phase), and KE4-interruption of cell proliferation (only for short-term exposure). The BMDL of the percentage of the S phase after 24 h exposure was the lowest among all the BMDLs of a good fit, with BMDL5 of 9.55 µM.

(1E,3E)-1,4-Dinitro-1,3-butadiene-Synthesis, Spectral Characteristics and Computational Study Based on MEDT, ADME and PASS Simulation.

The chemistry of conjugated nitrodienes is becoming increasingly popular. These molecules are successfully applied in cycloaddition to synthesize six-membered rings in Diels-Alder reactions. Nitrodienes can be also applied to obtain bis-compounds in [3+2] cycloaddition. Moreover, the presence of a nitro group in the structure provides a possibility of further modification of the products. The simplest symmetrical representative of conjugated nitrodienes is (1E,3E)-1,4-dinitro-1,3-butadiene. Although the first mentions of the compound date back to the early 1950s, the compound has not yet been examined thoroughly enough. Therefore, in this article, a comprehensive study of (1E,3E)-1,4-dinitro-1,3-butadiene has been described. For this purpose, an experimental study including the synthesis process as well as an evaluation of the spectral characteristics has been conducted. So as to better understand the properties of this compound, a computational study of reactivity indices based on MEDT and also an assessment of pharmacokinetics and biological activity according to ADME and PASS methodologies have been made. On this basis, some future application trends of (1E,3E)-1,4-dinitro-1,3-butadiene have been proposed.

Occurrence differences of hexachlorobutadiene and chlorobenzenes in road dust and roadside soil media in an industrial and residential mixed area in Eastern China.

The road dust and roadside soil can act as both sinks and sources of hexachlorobutadiene (HCBD) and chlorobenzenes (CBzs), but comparative research on these two adjacent media is extremely limited. In this study, HCBD and CBzs were simultaneously analyzed in road dust and roadside soil samples from an area containing both industrial factories and residential communities in Eastern China. The road dust there was found to have 2-6 times higher contents of HCBD (mean 1.14 ng/g, maximum 6.44 ng/g) and ∑Cl3-Cl6CBzs (22.8 ng/g, 90.6 ng/g) than those in the roadside soil. The spatial distributions of HCBD and CBzs in road dusts were affected by various types of sources, showing no significant discrepancy among the sites. On the contrast, HCBD and CBzs contamination in roadside soils occurring near several factories were strongly correlated to their industrial point sources. Risk assessments showed, at current contamination levels in the road dust and roadside soil, HCBD and CBzs are not likely to induce carcinogenic or non-carcinogenic risks to residents in the studied area. Nevertheless, road dust ingestion, as the major exposure pathway of HCBD and CBzs, should be avoided to reduce the exposure risk. These findings based on the contamination differences between two media provide a new perspective and evidence for screening important sources and exposure pathway of HCBD and CBzs, which would be helpful to their source identification and risk control.