Microglial TLR4 Mediates White Matter Injury in a Combined Model of Diesel Exhaust Exposure and Cerebral Hypoperfusion.

BACKGROUND: Air pollution particulate matter exposure and chronic cerebral hypoperfusion (CCH) contribute to white matter toxicity through shared mechanisms of neuroinflammation, oxidative stress, and myelin breakdown. Prior studies showed that exposure of mice to joint particulate matter and CCH caused supra-additive injury to corpus callosum white matter. This study examines the role of TLR4 (toll-like receptor 4) signaling in mediating neurotoxicity and myelin damage observed in joint particulate matter and CCH exposures. METHODS: Experiments utilized a novel murine model of inducible monocyte/microglia-specific TLR4 knockout (i-mTLR4-ko). Bilateral carotid artery stenosis (BCAS) was induced surgically to model CCH. TLR4-intact (control) and i-mTLR4-ko mice were exposed to 8 weeks of either aerosolized diesel exhaust particulate (DEP) or filtered air (FA) in 8 experimental groups: (1) control/FA (n=10), (2) control/DEP (n=10), (3) control/FA+BCAS (n=9), (4) control/DEP+BCAS (n=10), (5) i-mTLR4-ko/FA (n=9), (6) i-mTLR4-ko/DEP (n=8), (7) i-mTLR4-ko/FA+BCAS (n=8), and (8) i-mTLR4-ko/DEP+BCAS (n=10). Corpus callosum levels of 4-hydroxynonenal, 8-Oxo-2'-deoxyguanosine, Iba-1 (ionized calcium-binding adapter molecule 1), and dMBP (degraded myelin basic protein) were assayed via immunofluorescence to measure oxidative stress, neuroinflammation, and myelin breakdown, respectively. RESULTS: Compared with control/FA mice, control/DEP+BCAS mice exhibited increased dMBP (41%; P<0.01), Iba-1 (51%; P<0.0001), 4-hydroxynonenal (100%; P<0.0001), and 8-Oxo-2'-deoxyguanosine (65%; P<0.05). I-mTLR4 knockout attenuated responses to DEP/BCAS for all markers. CONCLUSIONS: i-mTLR4-ko markedly reduced neuroinflammation and oxidative stress and attenuated white matter degradation following DEP and CCH exposures. This suggests a potential role for targeting TLR4 signaling in individuals with vascular cognitive impairment, particularly those exposed to substantial ambient air pollution.

Identification of the cuproptosis-related molecular subtypes and an immunotherapy prognostic model in hepatocellular carcinoma.

BACKGROUND: Cuproptosis, a newly discovered mode of cell death, has been less studied in hepatocellular carcinoma (HCC). Exploring the molecular characteristics of different subtypes of HCC based on cuproptosis-related genes (CRGs) is meaningful to HCC. In addition, immunotherapy plays a pivotal role in treating HCC. Exploring the sensitivity of immunotherapy and building predictive models are critical for HCC. METHODS: The 357 HCC samples from the TCGA database were classified into three subtypes, Cluster 1, Cluster 2, and Cluster 3, based on the expression levels of ten CRGs genes using consensus clustering. Six machine learning algorithms were used to build models that identified the three subtypes. The molecular features of the three subtypes were analyzed and compared from some perspectives. Moreover, based on the differentially expressed genes (DEGs) between Cluster 1 and Cluster 3, a prognostic scoring model was constructed using LASSO regression and Cox regression, and the scoring model was used to predict the efficacy of immunotherapy in the IMvigor210 cohort. RESULTS: Cluster 3 had the worst overall survival compared to Cluster 1 and Cluster 2 (P = 0.0048). The AUC of the Catboost model used to identify Cluster 3 was 0.959. Cluster 3 was significantly different from the other two subtypes in gene mutation, tumor mutation burden, tumor microenvironment, the expression of immune checkpoint inhibitor genes and N6-methyladenosine regulatory genes, and the sensitivity to sorafenib. We believe Cluster 3 is more sensitive to immunotherapy from the above analysis results. Therefore, based on the DEGs between Cluster 1 and Cluster 3, we obtained a 7-gene scoring prognostic model, which achieved meaningful results in predicting immunotherapy efficacy in the IMvigor210 cohort (P = 0.013). CONCLUSIONS: Our study provides new ideas for molecular characterization and immunotherapy of HCC from machine learning and bioinformatics. Moreover, we successfully constructed a prognostic model of immunotherapy.

Age-related alteration in HNE elimination enzymes.

4-hydroxynonenal (HNE, 4-hydroxy-2-nonenal) is a primary α,ß-unsaturated aldehyde product of lipid peroxidation. The accumulation of HNE increases with aging and the mechanisms are mainly attributable to increased oxidative stress and decreased capacity of HNE elimination. In this review article, we summarize the studies on age-related change of HNE concentration and alteration of HNE metabolizing enzymes (GCL, GST, ALDHs, aldose reductase, and 20S-proteasome), and discuss potential mechanism of age-related decrease in HNE-elimination capacity by focusing on Nrf2 redox signaling.

Silencing Bach1 alters aging-related changes in the expression of Nrf2-regulated genes in primary human bronchial epithelial cells.

Nrf2 is the master transcription factor regulating the basal and inducible expression of antioxidant genes. With aging, the basal Nrf2 activity is increased but oxidant/electrophile-enhanced activation of Nrf2 signaling is diminished, and these changes are accompanied by an increased expression of Bach1, a repressor of Nrf2 signaling. In this limited follow-up study, we explored how Bach1 may be involved in aging-related alteration in Nrf2 signaling in primary human bronchial epithelial (HBE) cells. Silencing Bach1 with siRNA increased the basal mRNA expression of Nrf2 regulated genes including glutamate cysteine ligase catalytic (GCLC) and modifier subunit (GCLM), NAD(P)H oxidoreductase 1(NQO-1) and heme oxygenase 1(HO-1), in HBE cells from both young (aged 21-29 years) and older (aged 61-69 years) donors. On the other hand, Bach1 silencing affected the induction of Nrf2-regulated genes differentially in young and older HBE cells. Bach1 silencing significantly enhanced sulforaphane-induced expression of HO-1 but had no effect on that of GCLC, GCLM, and NQO1 in young HBE cells. In contrast, Bach1 silencing enhanced sulforaphane-induced expression of GCLC, GCLM and HO-1 but had no effect on that of NQO-1 in older HBE cells. In conclusion, these results suggest that increased Bach1 contributes to aging-related loss of electrophile-enhanced Nrf2 signaling.

Signaling by 4-hydroxy-2-nonenal: Exposure protocols, target selectivity and degradation.

4-hydroxy-2-nonenal (HNE), a major non-saturated aldehyde product of lipid peroxidation, has been extensively studied as a signaling messenger. In these studies a wide range of HNE concentrations have been used, ranging from the unstressed plasma concentration to far beyond what would be found in actual pathophysiological condition. In addition, accumulating evidence suggest that signaling protein modification by HNE is specific with only those proteins with cysteine, histidine, and lysine residues located in certain sequence or environments adducted by HNE. HNE-signaling is further regulated through the turnover of HNE-signaling protein adducts through proteolytic process that involve proteasomes, lysosomes and autophagy. This review discusses the HNE concentrations and exposure modes used in signaling studies, the selectivity of the HNE-adduction site, and the turnover of signaling protein adducts.

Protein cysteine oxidation in redox signaling: Caveats on sulfenic acid detection and quantification.

Oxidation of critical signaling protein cysteines regulated by H2O2 has been considered to involve sulfenic acid (RSOH) formation. RSOH may subsequently form either a sulfenyl amide (RSNHR') with a neighboring amide, or a mixed disulfide (RSSR') with another protein cysteine or glutathione. Previous studies have claimed that RSOH can be detected as an adduct (e.g., with 5,5-dimethylcyclohexane-1,3-dione; dimedone). Here, kinetic data are discussed which indicate that few proteins can form RSOH under physiological signaling conditions. We also present experimental evidence that indicates that (1) dimedone reacts rapidly with sulfenyl amides, and more rapidly than with sulfenic acids, and (2) that disulfides can react reversibly with amides to form sulfenyl amides. As some proteins are more stable as the sulfenyl amide than as a glutathionylated species, the former may account for some of the species previously identified as the "sulfenome" - the cellular complement of reversibly-oxidized thiol proteins generated via sulfenic acids.

TGFß1 rapidly activates Src through a non-canonical redox signaling mechanism.

Transforming growth factor-ß1 (TGF-ß) is involved in multiple cellular processes through Src activation. In the canonical pathway, Src activation is initiated by pTyr530 dephosphorylation followed by a conformational change allowing Tyr419 auto-phosphorylation. A non-canonical pathway in which oxidation of cysteine allows bypassing of pTyr530 dephosphorylation has been reported. Here, we examined how TGF-ß activates Src in H358 cells, a small cell lung carcinoma cell line. TGF-ß increased Src Tyr419 phosphorylation, but surprisingly, Tyr530 phosphorylation was increased rather than decreased. Vanadate, a protein tyrosine phosphatase inhibitor, stimulated Src activation itself, but rather than inhibiting Src activation by TGF-ß, activation by vanadate was additive with TGF-ß showing that pTyr530 dephosphorylation was not required. Thus, the involvement of the non-canonical oxidative activation was suspected. TGF-ß increased extracellular H2O2 transiently while GSH-ester and catalase abrogated Src activation by TGF-ß. Apocynin, a NADPH oxidase inhibitor, inhibited TGF-ß-stimulated H2O2 production. Furthermore, mutation of cysteines to alanine, 248C/A, 277C/A, or 501C/A abrogated, while 490C/A significantly reduced, TGF-ß-mediated Src activation. Taken together, the results indicate that TGF-ß-mediated Src activation operates largely through a redox dependent mechanism, resulting from enhanced H2O2 production through an NADPH oxidase and that cysteines 248, 277, 490, and 501 are critical for this activation.

Glutathione synthesis and its role in redox signaling.

Glutathione (GSH) is the most abundant antioxidant and a major detoxification agent in cells. It is synthesized through two-enzyme reaction catalyzed by glutamate cysteine ligase and glutathione synthetase, and its level is well regulated in response to redox change. Accumulating evidence suggests that GSH may play important roles in cell signaling. This review will focus on the biosynthesis of GSH, the reaction of S-glutathionylation (the conjugation of GSH with thiol residue on proteins), GSNO, and their roles in redox signaling.

Improving PD-1 blockade plus chemotherapy for complete remission of lung cancer by nanoPDLIM2.

Background: Immune checkpoint inhibitors (ICIs) and their combination with other therapies such as chemotherapy, fail in most cancer patients. We previously identified the PDZ-LIM domain-containing protein 2 (PDLIM2) as a bona fide tumor suppressor that is repressed in lung cancer to drive cancer and its chemo and immunotherapy resistance, suggesting a new target for lung cancer therapy improvement. Methods: Human clinical samples and data were used to investigate PDLIM2 genetic and epigenetic changes in lung cancer. Using an endogenous mouse lung cancer model faithfully recapitulating refractory human lung cancer and a clinically feasible nano-delivery system, we investigated the therapeutic efficacy, action mechanism, and safety of systemically administrated PDLIM2 expression plasmids encapsulated in nanoparticles (nanoPDLIM2) and its combination with PD-1 antibody and chemotherapeutic drugs. Results: PDLIM2 repression in human lung cancer involves both genetic deletion and epigenetic alteration. NanoPDLIM2 showed low toxicity, high tumor specificity, antitumor activity, and greatly improved the efficacy of anti-PD-1 and chemotherapeutic drugs, with complete tumor remission in most mice and substantial tumor reduction in the remaining mice by their triple combination. Mechanistically, nanoPDLIM2 increased major histocompatibility complex class I (MHC-I) expression, suppressed multi-drug resistance 1 (MDR1) induction and survival genes and other tumor-related genes expression in tumor cells, and enhanced lymphocyte tumor infiltration, turning the cold tumors hot and sensitive to ICIs and rendering them vulnerable to chemotherapeutic drugs and activated tumor-infiltrating lymphocytes (TILs) including those unleashed by ICIs. Conclusions: These studies established a clinically applicable PDLIM2-based combination therapy with great efficacy for lung cancer and possibly other cold cancers.

Nrf2-dependent induction of proteasome and Pa28αß regulator are required for adaptation to oxidative stress.

The ability to adapt to acute oxidative stress (e.g. H(2)O(2), peroxynitrite, menadione, and paraquat) through transient alterations in gene expression is an important component of cellular defense mechanisms. We show that such adaptation includes Nrf2-dependent increases in cellular capacity to degrade oxidized proteins that are attributable to increased expression of the 20 S proteasome and the Pa28αß (11 S) proteasome regulator. Increased cellular levels of Nrf2, translocation of Nrf2 from the cytoplasm to the nucleus, and increased binding of Nrf2 to antioxidant response elements (AREs) or electrophile response elements (EpREs) in the 5'-untranslated region of the proteasome ß5 subunit gene (demonstrated by chromatin immunoprecipitation (or ChIP) assay) are shown to be necessary requirements for increased proteasome/Pa28αß levels, and for maximal increases in proteolytic capacity and stress resistance; Nrf2 siRNA and the Nrf2 inhibitor retinoic acid both block these adaptive changes and the Nrf2 inducers DL-sulforaphane, lipoic acid, and curcumin all replicate them without oxidant exposure. The immunoproteasome is also induced during oxidative stress adaptation, contributing to overall capacity to degrade oxidized proteins and stress resistance. Two of the three immunoproteasome subunit genes, however, contain no ARE/EpRE elements, and Nrf2 inducers, inhibitors, and siRNA all have minimal effects on immunoproteasome expression during adaptation to oxidative stress. Thus, immunoproteasome appears to be (at most) minimally regulated by the Nrf2 signal transduction pathway.

Real-world effectiveness and safety of RC48-ADC alone or in combination with PD-1 inhibitors for patients with locally advanced or metastatic urothelial carcinoma: A multicenter, retrospective clinical study.

INTRODUCTION: Previous RC48 (Disitamab Vedotin) studies established that the safety and efficacy of RC48-antibody-drug conjugate (ADC), either alone or combined with toripalimab, for metastatic urothelial carcinoma (mUC) patients exhibiting human epidermal growth factor receptor 2 (HER2)-positive or even HER2-negative status after standard chemotherapy failure. METHODS: With locally advanced or metastatic urothelial carcinoma (la/mUC), patients who received RC48-ADC monotherapy or a combination with programmed cell death protein 1 (PD-1) inhibitors between August 2021 and October 2022 were enrolled in this retrospective observational study to evaluate the real-world antitumor effectiveness and safety. RESULTS: Among the 38 enrolled patients (29 males; median age 67.5 years [38-93]), 8 received RC48-ADC monotherapy, while 30 received combination therapy. Initially, 63.2% (24/38) of the patients had received ≥1 line of prior treatment, and 63.2% (24/38) had visceral metastasis. UC of the bladder represented the majority type in 68.4% (26/38) of cases. By the data cutoff in March 2023, the overall objective response rate (ORR) was 63.2% (95% CI, 47.1%-79.2%), with a disease control rate (DCR) of 89.5% (95% CI, 79.3%-99.7%). Median follow-up time was 10.6 months. The median progression-free survival (PFS) was 8.2 months (95% CI, 5.9-10.5), with a 6-month PFS rate of 63.2% and a 12-month PFS rate of 34.1%. Median overall survival (OS) was not reached, with a 12-month OS rate of 76.7%. The median duration of response was 7.3 months (95% CI, 4.6-10.0) among 24 patients evaluated as partial response (PR). The most common treatment-related adverse events (TRAEs) included anemia (71.1%), anorexia (57.9%), asthenia (52.6%), hypoesthesia (52.6%), bone marrow suppression (47.4%), alopecia (47.4%), nausea (44.7%), proteinuria (36.8%), vomiting (34.2%), and hypoalbuminemia (31.6%). No patient experienced TRAEs of Grade ≥3. One patient had an immune-related adverse event (irAE) of rash related to toripalimab. CONCLUSIONS: Both as monotherapy and in combination with PD-1 inhibitors, RC48-ADC exhibits promising effectiveness and manageable safety profile for mUC patients in real-world settings.

Magnetic resonance imaging of white matter response to diesel exhaust particles.

Air pollution is associated with risks of dementia and accelerated cognitive decline. Rodent air pollution models have shown white matter vulnerability. This study uses diffusion tensor imaging (DTI) to quantify changes to white matter microstructure and tractography in multiple myelinated regions after exposure to diesel exhaust particulate (DEP). Adult C57BL/6 male mice were exposed to re-aerosolized DEP (NIST SRM 2975) at a concentration of 100 ug/m3 for 200 hours. Ex-vivo MRI analysis and fractional anisotropy (FA)-aided white matter tractography were conducted to study the effect of DEP exposure on the brain white matter tracts. Immunohistochemistry was used to assess myelin and axonal structure. DEP exposure for 8 weeks altered myelin composition in multiple regions. Diffusion tensor imaging (DTI) showed decreased FA in the corpus callosum (30%), external capsule (15%), internal capsule (15%), and cingulum (31 %). Separate immunohistochemistry analyses confirmed prior findings. Myelin basic protein (MBP) was decreased (corpus callosum: 28%, external capsule: 29%), and degraded MPB increased (corpus callosum: 32%, external capsule: 53%) in the DEP group. White matter is highly susceptible to chronic DEP exposure. This study demonstrates the utility of DTI as a neuroanatomical tool in the context of air pollution and white matter myelin vulnerability.

Air pollution nanoparticle and alpha-synuclein fibrils synergistically decrease glutamate receptor A1, depending upon nPM batch activity.

Background: Epidemiological studies have variably linked air pollution to increased risk of Parkinson's disease (PD). However, there is little experimental evidence for this association. Alpha-synuclein (α-syn) propagation plays central roles in PD and glutamate receptor A1 (GluA1) is involved in memory and olfaction function. Methods: Each mouse was exposed to one of three different batches of nano-particulate matter (nPM) (300 µg/m3, 5 h/d, 3 d/week), collected at different dates, 2017-2019, in the same urban site. After these experiments, these nPM batches were found to vary in activity. C57BL/6 female mice (3 mo) were injected with pre-formed murine α-synuclein fibrils (PFFs) (0.4 µg), which act as seeds for α-syn aggregation. Two exposure paradigms were used: in Paradigm 1, PFFs were injected into olfactory bulb (OB) prior to 4-week nPM (Batch 5b) exposure and in Paradigm 2, PFFs were injected at 4th week during 10-week nPM exposure (Batches 7 and 9). α-syn pSer129, microglia Iba1, inflammatory cytokines, and Gria1 expression were measured by immunohistochemistry or qPCR assays. Results: As expected, α-syn pSer129 was detected in ipsilateral OB, anterior olfactory nucleus, amygdala and piriform cortex. One of the three batches of nPM caused a trend for elevated α-syn pSer129 in Paradigm 1, but two other batches showed no effect in Paradigm 2. However, the combination of nPM and PFF significantly decreased Gria1 mRNA in both the ipsi- and contra-lateral OB and frontal cortex for the most active two nPM batches. Neither nPM nor PFFs alone induced responses of microglia Iba1 and expression of Gria1 in the OB and cortex. Conclusion: Exposures to ambient nPM had weak effect on α-syn propagation in the brain in current experimental paradigms; however, nPM and α-syn synergistically downregulated the expression of Gria1 in both OB and cortex.

Multimodal X-ray nano-spectromicroscopy analysis of chemically heterogeneous systems.

Understanding the nanoscale chemical speciation of heterogeneous systems in their native environment is critical for several disciplines such as life and environmental sciences, biogeochemistry, and materials science. Synchrotron-based X-ray spectromicroscopy tools are widely used to understand the chemistry and morphology of complex material systems owing to their high penetration depth and sensitivity. The multidimensional (4D+) structure of spectromicroscopy data poses visualization and data-reduction challenges. This paper reports the strategies for the visualization and analysis of spectromicroscopy data. We created a new graphical user interface and data analysis platform named XMIDAS (X-ray multimodal image data analysis software) to visualize spectromicroscopy data from both image and spectrum representations. The interactive data analysis toolkit combined conventional analysis methods with well-established machine learning classification algorithms (e.g. nonnegative matrix factorization) for data reduction. The data visualization and analysis methodologies were then defined and optimized using a model particle aggregate with known chemical composition. Nanoprobe-based X-ray fluorescence (nano-XRF) and X-ray absorption near edge structure (nano-XANES) spectromicroscopy techniques were used to probe elemental and chemical state information of the aggregate sample. We illustrated the complete chemical speciation methodology of the model particle by using XMIDAS. Next, we demonstrated the application of this approach in detecting and characterizing nanoparticles associated with alveolar macrophages. Our multimodal approach combining nano-XRF, nano-XANES, and differential phase-contrast imaging efficiently visualizes the chemistry of localized nanostructure with the morphology. We believe that the optimized data-reduction strategies and tool development will facilitate the analysis of complex biological and environmental samples using X-ray spectromicroscopy techniques.

Identification and exploration of the pyroptosis-related molecular subtypes of breast cancer by bioinformatics and machine learning.

OBJECTIVES: To classify breast cancer (BRCA) according to the expression of pyroptosis-related genes and explore their molecular characteristics. METHODS: Nonnegative matrix factorization (NMF) was used for subtype classification based on 21 pyroptosis-related genes in the TCGA database. Survival analysis and t-distributed stochastic neighbor embedding (t-SNE) analysis were conducted to assess the NMF results' performance. XGBoost, CatBoost, logistic regression, neural network, random forest, and support vector machine were utilized to perform supervised machine learning and construct prediction models. Genetic mutations, tumor mutational burden, immune infiltration, methylation, and drug sensitivity were analyzed to explore the molecular signatures of different subtypes. Lasso, RF, and Cox regression were operated to construct a prognostic model based on differentially expressed genes. RESULTS: BRCA patients were divided into two subtypes (named Cluster1 and Cluster2). Survival analysis (P = 0.02) and t-SNE analysis demonstrated that Cluster1 and Cluster2 were well classified. The XGBoost model achieved reliable predictions on both training and validation sets. Regarding molecular characteristics, Cluster1 had higher TMB, immune cell infiltration, and m6A methylation-related gene expression than Cluster2. There was also a statistically significant difference between the two subtypes concerning drug susceptibility. Finally, a 5-gene prognostic model was constructed using Lasso, RF, and Cox regression and validated in the GEO database. CONCLUSION: Our study may provide new insights from bioinformatics and machine learning for exploring pyroptosis-related subtypes and their respective molecular signatures in BRCA. In addition, our models may be helpful for the treatment and prognosis of BRCA.

Neurotoxicity of Diesel Exhaust Particles.

BACKGROUND: Air pollution particulate matter (PM) is strongly associated with risks of accelerated cognitive decline, dementia and Alzheimer's disease. Ambient PM batches have variable neurotoxicity by collection site and season, which limits replicability of findings within and between research groups for analysis of mechanisms and interventions. Diesel exhaust particles (DEP) offer a replicable model that we define in further detail. OBJECTIVE: Define dose- and time course neurotoxic responses of mice to DEP from the National Institute of Science and Technology (NIST) for neurotoxic responses shared by DEP and ambient PM. METHODS: For dose-response, adult C57BL/6 male mice were exposed to 0, 25, 50, and 100µg/m3 of re-aerosolized DEP (NIST SRM 2975) for 5 h. Then, mice were exposed to 100µg/m3 DEP for 5, 100, and 200 h and assayed for amyloid-ß peptides, inflammation, oxidative damage, and microglial activity and morphology. RESULTS: DEP exposure at 100µg/m3 for 5 h, but not lower doses, caused oxidative damage, complement and microglia activation in cerebral cortex and corpus callosum. Longer DEP exposure for 8 weeks/200 h caused further oxidative damage, increased soluble Aß, white matter injury, and microglial soma enlargement that differed by cortical layer. CONCLUSION: Exposure to 100µg/m3 DEP NIST SRM 2975 caused robust neurotoxic responses that are shared with prior studies using DEP or ambient PM0.2. DEP provides a replicable model to study neurotoxic mechanisms of ambient PM and interventions relevant to cognitive decline and dementia.

Reexamination of the electrophile response element sequences and context reveals a lack of consensus in gene function.

The electrophile response element (EpRE) is essential for regulation of many genes involved in protection against toxic agents. Putative EpRE core sequences (TGAnnnnGC) are localized in 5'-flanking regions (5'-UTR) of these genes but specificity of the internal bases and whether location affects function has not been refined. The catalytic subunit of human glutamate cysteine ligase (GCLC) gene is well documented to be under EpRE regulation and four sequences having an EpRE "consensus" sequence were reported with only one (EpRE 4) responsive to electrophiles. Using GCLC as a model, we asked whether the internal variable or flanking nucleotides and the location of the sequence were required for functional activity in response to 4-hydroxenonenal (HNE). We found that thirteen putative EpRE core sequences (TGAnnnnGC) were localized in 5'-UTR of GCLC and confirmed that EpRE 4 showed both constitutive and HNE-inducible activity. Four other sequences exhibited only constitutive activity while other putative EpREs demonstrated no activity. Nucleotide mutagenesis demonstrated specific requirements for internal and flanking nucleotides that were specific for the electrophilic response and that a TRE-like sequence within EpRE was essential for basal (non-electrophile-dependent) activity. Furthermore, EpRE 4 relocated to positions of other putative EpREs maintained activity but moving other EpREs to the EpRE 4 location did not. Thus in GCLC, specific flanking and internal nucleotides within EpRE were far more important for function than previously described while location did not influence activity. These two findings bring into question the meaning of the phrase, "consensus sequence" for this important cis element.

Targeting oxidative stress in disease: promise and limitations of antioxidant therapy.

Oxidative stress is a component of many diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer disease and cancer. Although numerous small molecules evaluated as antioxidants have exhibited therapeutic potential in preclinical studies, clinical trial results have been disappointing. A greater understanding of the mechanisms through which antioxidants act and where and when they are effective may provide a rational approach that leads to greater pharmacological success. Here, we review the relationships between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness and how antioxidant defences can be increased through physiological signalling, dietary components and potential pharmaceutical intervention.

Lactate and blood ammonia on admission as biomarkers to predict the prognosis of patients with acute mushroom poisoning and liver failure: a retrospective study.

The diagnosis of liver damage induced by mushroom poisoning is still challenging. This study aims to screen the early biological indexes that could predict acute mushroom poisoning with liver damage. The patients with acute mushroom poisoning and liver damage admitted to The First Affiliated Hospital of Dalian Medical University，China from July 2007 to August 2017 were analyzed retrospectively. A total of 66 patients were enrolled in this study, with 44 and 22 patients in the liver injury group and liver failure group, respectively. Ten patients in the liver failure group died, with a mortality of 45.5% in this group. Multivariable Cox regression showed that the blood ammonia (NH3) and lactic acid (Lac) at the time of admission were independently associated with the in-hospital time to death for patients with liver failure induced by mushroom poisoning. Lactate and blood ammonia at the time of admission could be used to predict the prognosis of patients with acute mushroom poisoning and liver failure.

Air Pollution Particulate Matter Exposure and Chronic Cerebral Hypoperfusion and Measures of White Matter Injury in a Murine Model.

BACKGROUND: Exposure to ambient air pollution particulate matter (PM) is associated with increased risk of dementia and accelerated cognitive loss. Vascular contributions to cognitive impairment are well recognized. Chronic cerebral hypoperfusion (CCH) promotes neuroinflammation and blood-brain barrier weakening, which may augment neurotoxic effects of PM. OBJECTIVES: This study examined interactions of nanoscale particulate matter (nPM; fine particulate matter with aerodynamic diameter ≤200 nm) and CCH secondary to bilateral carotid artery stenosis (BCAS) in a murine model to produce white matter injury. Based on other air pollution interactions, we predicted synergies of nPM with BCAS. METHODS: nPM was collected using a particle sampler near a Los Angeles, California, freeway. Mice were exposed to 10 wk of reaerosolized nPM or filtered air (FA) for 150 h. CCH was induced by BCAS surgery. Mice (C57BL/6J males) were randomized to four exposure paradigms: a) FA, b) nPM, c) FA + BCAS, and d) nPM + BCAS. Behavioral outcomes, white matter injury, glial cell activation, inflammation, and oxidative stress were assessed. RESULTS: The joint nPM + BCAS group exhibited synergistic effects on white matter injury (2.3× the additive nPM and FA + BCAS scores) with greater loss of corpus callosum volume on T2 magnetic resonance imaging (MRI) (30% smaller than FA group). Histochemical analyses suggested potential microglial-specific inflammatory responses with synergistic effects on corpus callosum C5 immunofluorescent density and whole brain nitrate concentrations (2.1× and 3.9× the additive nPM and FA + BCAS effects, respectively) in the joint exposure group. Transcriptomic responses (RNA-Seq) showed greater impact of nPM + BCAS than individual additive effects, consistent with changes in proinflammatory pathways. Although nPM exposure alone did not alter working memory, the nPM + BCAS cohort demonstrated impaired working memory when compared to the FA + BCAS group. DISCUSSION: Our data suggest that nPM and CCH contribute to white matter injury in a synergistic manner in a mouse model. Adverse neurological effects may be aggravated in a susceptible population exposed to air pollution. https://doi.org/10.1289/EHP8792.