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Genome-wide association studies (GWAS) conducted in European ancestry (EA) have identified hundreds of single-nucleotide polymorphisms (SNPs) associated with general cognitive function and/or Alzheimer’s disease (AD). The association between these SNPs and cognitive function has not been fully evaluated in populations with complex genetic substructure such as South Asians. This study investigated whether SNPs identified in EA GWAS, either individually or as polygenic risk scores (PRSs), were associated with general cognitive function and 5 broad cognitive domains in 932 South Asians from the Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD). We found that SNPs identified from AD GWAS were more strongly associated with cognitive function in LASI-DAD than those from a GWAS of general cognitive function. PRSs for general cognitive function and AD explained up to 1.1% of the variability in LASI-DAD cognitive domain scores. Our study represents an important stepping stone toward better characterization of the genetic architecture of cognitive aging in the Indian/South Asian population and highlights the need for further research that may lead to the identification of new variants unique to this population.

Salivary elicitors secreted by herbivorous insects can be perceived by host plants to trigger plant immunity. However, how insects secrete other salivary components to subsequently attenuate the elicitor-induced plant immunity remains poorly understood. Here, we study the small brown planthopper, Laodelphax striatellus salivary sheath protein LsSP1. Using Y2H, BiFC and LUC assays, we show that LsSP1 is secreted into host plants and binds to salivary sheath via mucin-like protein (LsMLP). Rice plants pre-infested with dsLsSP1-treated L. striatellus are less attractive to L. striatellus nymphs than those pre-infected with dsGFP-treated controls. Transgenic rice plants with LsSP1 overexpression rescue the insect feeding defects caused by a deficiency of LsSP1 secretion, consistent with the potential role of LsSP1 in manipulating plant defenses. Our results illustrate the importance of salivary sheath proteins in mediating the interactions between plants and herbivorous insects.

SNPs in ABCA7 confer the largest genetic risk for Alzheimer’s Disease (AD) in African Americans (AA) after APOE ε4. However, the relationship between ABCA7 and cognitive function has not been thoroughly examined. We investigated the effects of five known AD risk SNPs and 72 CpGs in ABCA7, as well as their interactions, on general cognitive function (cognition) in 634 older AA without dementia from Genetic Epidemiology Network of Arteriopathy (GENOA). Using linear mixed models, no SNP or CpG was associated with cognition after multiple testing correction, but five CpGs were nominally associated (p < 0.05). Four SNP-by-CpG interactions were associated with cognition (FDR q < 0.1). Contrast tests show that methylation is associated with cognition in some genotype groups (p < 0.05): a 1% increase at cg00135882 and cg22271697 is associated with a 0.68 SD decrease and 0.14 SD increase in cognition for those with the rs3764647 GG/AG (p = 0.004) and AA (p = 2 × 10−4) genotypes, respectively. In addition, a 1% increase at cg06169110 and cg17316918 is associated with a 0.37 SD decrease (p = 2 × 10−4) and 0.33 SD increase (p = 0.004), respectively, in cognition for those with the rs115550680 GG/AG genotype. While AD risk SNPs in ABCA7 were not associated with cognition in this sample, some have interactions with proximal methylation on cognition.

The application of straw biochar in farmland in Dongting Lake area can realize the resource utilization of straw and reduce environmental risk. In 2020, a rice pot experiment was conducted to investigate the effects of different biochar application levels on ammonia volatilization rate, cumulative ammonia volatilization, pH value, and NH在洞庭湖区农田施用秸秆生物炭不仅能实现秸秆资源化利用,还可降低环境污染压力。本研究于2020年采用水稻盆栽试验,研究了不同南荻秸秆生物炭施用量对土壤氨挥发速率、累积氨挥发量、表面水pH值和NH

DNA methylation age acceleration, the discrepancy between epigenetic age and chronological age, is associated with mortality and chronic diseases, including diabetes, hypertension, and hyperlipidemia. In this study, we investigate whether medications commonly used to treat these diseases in 15 drug categories are associated with four epigenetic age acceleration measures: HorvathAge acceleration (HorvathAA), HannumAge acceleration (HannumAA), PhenoAge acceleration, and GrimAge acceleration (GrimAA) using cross-sectional (Phase 1, N=1,100) and longitudinal (Phases 1 and 2, N=266) data from African Americans in the Genetic Epidemiology Network of Arteriopathy (GENOA) study. In cross-sectional analyses, the use of calcium channel blockers was associated with 1.27 years lower HannumAA after adjusting for covariates including hypertension (p=0.001). Longitudinal analyses showed that, compared to those who never used antihypertensives, those who started to take antihypertensives after Phase 1 had a 0.97-year decrease in GrimAA (p=0.007). In addition, compared to those who never used NSAID analgesics, those who started to take them after Phase 1 had a 2.61-year increase in HorvathAA (p=0.0005). Our study demonstrates that three commonly used medications are associated with DNAm age acceleration in African Americans and sheds light on the potential epigenetic effects of pharmaceuticals on aging at the cellular level.

Imidacloprid, a neonicotinoid insecticide, is widely applied to control insect pests across a broad spectrum. Though the impact of residues from this chemical pesticide on non-target organisms in the field has been reported, it was not well characterized across a wide range of ecosystems, especially for some species considered as environmental indicators that live in forests. The effects of sublethal dose of imidacloprid on firefly, Pyrocoelia analis, were analyzed physiologically and biochemically in this study to better understand the impact of chemical pesticide application on environmental indicators such as fireflies. After imidacloprid treatment, the midgut tissues of the larva presented an abnormal morphology featured as atrophy of fat body cells, shrinking cells, and the destruction of a midgut structure. The activities of antioxidant enzymes, superoxide dismutase, catalase, and peroxidase were noticeably increased during early exposure to sublethal imidacloprid and then decreased at later stages. The malondialdehyde content significantly increased after 12 h of exposure to imidacloprid compared with the control. Similarly, the enzyme activities of polyphenol oxidase and acetylcholinesterase were increased after the imidacloprid treatment and then decreased at the later stage. In summary, a sublethal dose of imidacloprid caused destructive change in the tissue structure, and this damage was followed by an excessive reactive oxygen species that could not be eliminated by antioxidant enzymes. Our results indicated that the residues of imidacloprid might cause severe toxicity to non-target insects in the environment even far away from the agro-ecosystem where the chemicals were applied.

The spotted lanternfly, Lycorma delicatula, is an invasive pest that causes serious economic losses to fruit and wood. Here, we identified a novel iflavirus from the spotted lanternfly, temporarily named Lycorma delicatula iflavirus 1 (LDIV1). The full genome sequence of LDIV1 was 10,222 nt in length, which encoded a polyprotein that contained a picornavirus capsid-protein-domain-like domain, a cricket paralysis virus capsid superfamily domain, a RNA helicase domain, a peptidase C3 superfamily domain, and a RNA-dependent RNA polymerase (RdRp) domain. LDIV1 efficiently replicated in host insect and activated the small interfering RNA (siRNA)-based host antiviral immunity. Phylogenetic analysis demonstrated that LDIV1 was the closest to Picornavirales sp, with 61.7% sequence identity in the RdRp region, and 57.6% sequence identity in the coat protein region, which met the demarcation criteria of new species in the genus Iflavirus. To the best of our knowledge, LDIV1 is the first virus discovered in L. delicatula.

Organophosphorus pesticides are effective, cheap, and used extensively but can harm aquatic organism and human health. Here, water quality criteria (WQCs) for dichlorvos (DDVP) and malathion (MAL) were derived. Nine aquatic organisms native to China were used in toxicity tests. Published toxicity data for aquatic organisms native and non-native to China were also analyzed. DDVP and MAL WQCs were derived using (log-normal model) species sensitivity distributions. Species sensitivity distribution curves indicated native and non-native species have different sensitivities to DDVP. The sensitivities of native and non-native species to MAL were not different because non-native species data for fewer than eight genera were available, so further research is required. The results indicated that native species need to be considered when deriving WQCs. The criteria maximum concentration (CMC) and criteria continuous concentration (CCC) were 1.33 and 0.132 μg/L, respectively, for DDVP, and 0.100 and 0.008 μg/L, respectively, for MAL. The CMCs for DDVP and MAL derived using ETX 2.0 software and species sensitivity ranks were different from the CMCs obtained using the SSD method because of parameter uncertainties. The DDVP and MAL WQCs were significantly lower than Chinese surface water quality standard thresholds. The results provide basic data for revising these thresholds.

Simple Summary The bean bug, Riptortus pedestris (Fabricius) is a notorious pest of soybean crops in Asia. During the feeding process, the bug secretes a mixture of salivary components, which play critical roles in the insect–plant interactions. In the present study, a total of 136 salivary proteins were identified by transcriptomic and proteomic approaches. Among them, five proteins (RpSP10.3, RpSP13.4, RpSP13.8, RpSP17.8, and RpSP10.2) were capable of inducing cell death, reactive oxygen species (ROS) burst, and hormone signal changes, indicating the potential roles of these proteins in eliciting plant defenses. Our results provide a good resource for future functional studies of bug salivary effectors and might be useful in pest management. Abstract The bean bug, Riptortus pedestris (Fabricius), is one of the most important soybean pests. It damages soybean leaves and pods with its piercing-sucking mouthparts, causing staygreen-like syndromes in the infested crops. During the feeding process, R. pedestris secretes a mixture of salivary proteins, which play critical roles in the insect–plant interactions and may be responsible for staygreen-like syndromes. The present study aimed to identify the major salivary proteins in R. pedestris saliva by transcriptomic and proteomic approaches, and to screen the proteins that potentially induced plant defense responses. Altogether, 136 salivary proteins were identified, and a majority of them were involved in hydrolase and binding. Additionally, R. pedestris saliva contained abundant bug-specific proteins with unknown function. Transient expression of salivary proteins in Nicotiana benthamiana leaves identified that RpSP10.3, RpSP13.4, RpSP13.8, RpSP17.8, and RpSP10.2 were capable of inducing cell death, reactive oxygen species (ROS) burst, and hormone signal changes, indicating the potential roles of these proteins in eliciting plant defenses. Our results will shed more light on the molecular mechanisms underlying the plant–insect interactions and are useful for pest management.

To study the different methods of artificial intelligence (AI)-assisted Ki-67 scoring of clinical invasive ductal carcinoma (IDC) of the breast and to compare the results.A total of 100 diagnosed IDC cases were collected, including slides of HE staining and immunohistochemical Ki-67 staining and diagnosis results. The slides were scanned and turned into whole slide image (WSI), which were then scored with AI. There were two AI scoring methods. One was fully automatic counting by AI, which used the scoring system of Ki-67 automatic diagnosis to do counting with the whole image of WSI. The second method was semi-automatic AI counting, which required manual selection of areas for counting, and then relied on an intelligent microscope to conduct automatic counting. The diagnostic results of pathologists were taken as the results of pure manual counting. Then the Ki-67 scores obtained by manual counting, semi-automatic AI counting and automatic AI counting were pairwise compared. The Ki-67 scores obtained from the manual counting (pathological diagnosis results), semi-automatic AI and automatic AI counts were pair-wise compared and classified according to three levels of difference: difference ≤10%, difference of10%-30% and difference ≥30%. Intra-class correlation coefficient (The automatic AI counting of Ki-67 takes 5-8 minutes per case, the semi-automatic AI counting takes 2-3 minutes per case, and the manual counting takes 1-3 minutes per case. When results of the two AI counting methods were compared, the difference in Ki-67 scores was all within 10% (100% of the total), and theAI automatic counting has the advantage of requiring less manpower, for the pathologist is involved only for the verification of the diagnosis results at the end. However, the semi-automatic method is better suited to the diagnostic habits of pathologists and has a shorter turn-over time compared with that of the fully automatic AI counting method. Furthermore, in spite of its higher repeatability, AI counting, cannot serve as a full substitute for pathologists, but should instead be viewed as a powerful auxiliary tool.

In the interdisciplinary field of data-driven models and computational fluid mechanics, the reduced-order model for flow field prediction is mainly constructed by a convolutional neural network (CNN) in recent years. However, the standard CNN is only applicable to data with Euclidean spatial structure, while data with non-Euclidean properties can only be convolved after pixelization, which usually leads to decreased data accuracy. In this work, a novel data-driven framework based on graph convolution network (GCN) is proposed to allow the convolution operator to predict fluid dynamics on non-uniform structured or unstructured mesh data. This is achieved by the fact that the graph data inherit the spatial characteristics of the mesh and by the message passing mechanism of GCN. The conversion method from the form of mesh data to graph data and the operation mechanism of GCN are clarified. Moreover, additional relevance features and weight loss function of the dataset are also investigated to improve the model performance. The model learns an end-to-end mapping between the mesh spatial features and the physical flow field. Through our studies of various cases of internal flow, it is shown that the proposed GCN-based model offers excellent adaptability to non-uniformly distributed mesh data, while also achieving a high accuracy and three-order speedup compared with numerical simulation. Our framework generalizes the graph convolution network to flow field prediction and opens the door to further extending GCN to most existing data-driven architectures of fluid dynamics in the future.

Deep reinforcement learning (DRL) has gradually emerged as an effective and novel method to achieve active flow control with outstanding performance. This paper focuses on exploring the strategy of improving learning efficiency and control performance of a new task using existing control experience. More specifically, the proximal policy optimization algorithm is used to control the flow past a circular cylinder using jets. The DRL controllers trained from the initialized parameter are able to obtain drag reductions of 8%, 18.7%, 18.4%, and 25.2%, at Re = 100, 200, 300, and 1000, respectively, and it takes more episodes to converge for the cases with higher Reynolds number, due to the increased flow complexity. Furthermore, the agent trained at high Reynolds number shows satisfied control performance when it is applied to the lower Reynolds number cases, which proves a strong correlation between the control policy and the flow patterns between the flows under different conditions. To better utilize the experience of the control policy of the trained agent, the flow control tasks with Re = 200, 300, and 1000 are retrained, based on the trained agent at Re = 100, 200, and 300, respectively. Our results show that a dramatic enhancement of the learning efficiency can be achieved; that is, the number of the training episodes reduces to be less than 20% of the agents trained with random initialization. Moreover, for each flow condition drag reduction approaches a significant level of 20.9%, 27.7%, and 36.1%, respectively. The great performance of the transfer training method of the DRL agent shows its potential on economizing the training cost and improving control effectiveness, especially for complex control tasks.

The repository contains : - Dataused for PMF analysis - Software installation packageused for data management of soil heavy metal Please, contact H. Jiang (gentlemanjianghu@foxmail.com) for additional information.

This paper applies deep reinforcement learning (DRL) on the synthetic jet control of flows over an NACA (National Advisory Committee for Aeronautics) 0012 airfoil under weak turbulent condition. Based on the proximal policy optimization method, the appropriate strategy for controlling the mass rate of a synthetic jet is successfully obtained at [Formula: see text]. The effectiveness of the DRL based active flow control (AFC) method is first demonstrated by studying the problem with constant inlet velocity, where a remarkable drag reduction of 27.0% and lift enhancement of 27.7% are achieved, accompanied by an elimination of vortex shedding. Then, the complexity of the problem is increased by changing the inlet velocity condition and reward function of the DRL algorithm. In particular, the inlet velocity conditions pulsating at two different frequencies and their combination are further applied, where the airfoil wake becomes more difficult to suppress dynamically and precisely; and the reward function additionally contains the goal of saving the energy consumed by the synergetic jets. After training, the DRL agent still has the ability to find a proper control strategy, where significant drag reduction and lift stabilization are achieved, and the agent with considerable energy saving is able to save the energy consumption of the synergetic jets for 83%. The performance of the DRL based AFC proves the strong ability of DRL to deal with fluid dynamics problems usually showing high nonlinearity and also serves to encourage further investigations on DRL based AFC.

The potential role of p38 mitogen-activated protein (MAP) kinase in platelet-derived growth factor receptor-alpha (PDGF-Ralpha) gene expression was investigated using cultured rat pulmonary myofibroblasts. p38 MAP kinase was constitutively expressed in myofibroblasts and activated by interleukin (IL)-1beta. A pyridinylimidazole compound, SB203580, completely inhibited the ability of p38 MAP kinase activity to phosphorylate PHAS-1 substrate. SB203580 inhibited IL-1beta-induced up-regulation of PDGF-Ralpha mRNA and protein in a concentration-dependent manner. Other kinase inhibitors, including the mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor PD98059, did not block up-regulation of PDGF-Ralpha. The IL-1beta-induced increase in the number of (125)I-PDGF-AA-binding sites at the cell surface was reduced70% by pretreatment with SB203580. Accordingly, an enhancement of PDGF-AA-stimulated DNA synthesis following IL-1beta pretreatment was blocked70% by SB203580. SB203580 did not affect IL-1beta-induced ERK activation, yet enhanced IL-1beta-induced JNK activation approximately 2-fold. Treatment of cells with SB203580 after inhibition of transcription by actinomycin D decreased the half-life of IL-1beta-induced PDGF-Ralpha mRNA from4 to approximately 1.5 h. Moreover, pretreatment of cells with cycloheximide blocked induction of PDGF-Ralpha mRNA by IL-1beta, suggesting that de novo protein synthesis was required for PDGF-Ralpha mRNA stabilization. These data indicate that p38 MAP kinase regulates PDGF-Ralpha expression at the translational level by signaling the synthesis of an mRNA-stabilizing protein.

Induction of the α-platelet-derived growth factor receptor (PDGF-Rα) by IL-1β in lung myofibroblasts enhances mitogenic and chemotactic responses to PDGF, and this could be a mechanism of myofibroblast hyperplasia during lung fibrogenesis. Since the regulation of many genes by IL-1β involves activation of NF-κB and mitogen-activated protein (MAP) kinases, we examined these signaling pathways in the control of PDGF-Rα expression by IL-1β in cultured rat lung myofibroblasts. Treatment of cells with pyrrolidine dithiocarbamate (PDTC), an antioxidant that inhibits NF-κB activation, completely blocked PDGF-Rα up-regulation by IL-1β as assayed by [125I]PDGF-AA binding and PDGF-Rα mRNA expression, suggesting a role for NF-κB. However, while IL-1β and TNF-α both induced nuclear binding of the Rel proteins p50 and p65 to an NF-κB consensus oligonucleotide in gel shift assays and caused transient degradation of inhibitor of NF-κB-α (IκB-α) in the cytoplasm of myofibroblasts, only IL-1β up-regulated PDGF-Rα. These results suggest that NF-κB activation alone is not sufficient for up-regulation of PDGF-Rα. An investigation of MAP kinase signaling pathways revealed that IL-1β or PDTC activated extracellular signal-regulated kinase-2 (ERK-2) and c-jun NH2 terminal kinase-1 (JNK-1) phosphorylation of PHAS-1 and c-Jun substrates, respectively. Pretreatment of cells with the MAP kinase kinase-1 (MEK1) inhibitor PD 98059 blocked IL-1β-induced activation of ERK-2 by more than 90% but enhanced IL-1β-stimulated induction of PDGF-Rα expression fourfold. Taken together, these data suggest that IL-1β activates both positive and negative signaling pathways that control the expression of PDGF-Rα. IL-1β appears to mediate its negative effects on PDGF-Rα expression via MAP kinase activation, while the factor(s) that mediate induction of PDGF-Rα remain to be elucidated.

The apolipoprotein E (APOE) epsilon2 allele has been associated with both Parkinson's disease (PD) and lower low-density lipoprotein cholesterol (LDL-C). We tested the hypothesis that lower LDL-C may be associated with PD. This case-control study used fasting lipid profiles obtained from 124 PD cases and 112 controls. The PD cases were recruited from consecutive cases presenting at our tertiary Movement Disorder Clinic, and the controls were recruited from the spouse populations of the same clinic. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from unconditional logistic regressions, adjusting for age, gender, smoking status, and use of cholesterol-lowering agents. Lower LDL-C concentrations were associated with a higher occurrence of PD. Compared with participants with the highest LDL-C (> or =138 mg/dL), the OR was 2.2 (95% CI = 0.9-5.1) for participants with LDL-C of 115 to 137, 3.5 (95% CI = 1.6-8.1) for LDL-C of 93 to 114, and 2.6 (95% CI = 1.1-5.9) for LDL-C of < or = 92. Interestingly, use of either cholesterol-lowering drugs, or statins alone, was related to lower PD occurrence. Thus, our data provide preliminary evidence that low LDL-C may be associated with higher occurrence of PD, and/or that statin use may lower PD occurrence, either of which finding warrants further investigation.

Vanadium compounds present in air pollution particulate matter activate signal transduction pathways in pulmonary cell types leading to pathological outcomes including aberrant cell proliferation, apoptosis, and cytokine expression. Vanadium has been proposed to activate transcription factors via the generation of hydrogen peroxide (H2O2). We investigated the mechanisms through which vanadium pentoxide (V2O5), the major form of vanadium released from the industrial burning of fuel oil, activated the signal transducer and activator of transcription (STAT)-1. V2O5-induced STAT-1 activation was blocked by catalase and N-acetyl-L-cysteine (NAC), suggesting vanadium-induced generation of H2O2. Surprisingly, however, V2O5 did not increase H2O2 levels released by rat lung myofibroblasts into cell culture supernatants. Instead, these quiescent myofibroblasts spontaneously released micromolar concentrations of H2O2, and the addition of V2O5 reduced H2O2 levels in cell culture supernatants within minutes. V2O5 suppressed H2O2 for as long as 24 h. Differences in the temporal activation of STAT-1 and p38 MAPK were observed following V2O5 or H2O2 treatment, and STAT-1 activation by V2O5 or H2O2 was attenuated by an inhibitor of the EGF receptor tyrosine kinase (AG1478) or p38 MAPK (SB203580). The phosphorylation of p38 MAPK by V2O5 was inhibited by NAC and catalase, yet the EGF receptor inhibitor AG1478 had no effect on V2O5-induced p38 MAPK activation. Collectively, our findings support the novel hypothesis that H2O2 spontaneously generated by myofibroblasts fuels vanadium-induced activation of STAT-1. Moreover, p38 MAPK and EGF receptor activation are required for V2O5-induced STAT-1 activation.

Upregulation of the platelet-derived growth factor (PDGF) receptor-alpha (PDGFR-alpha) is a mechanism of myofibroblast hyperplasia during pulmonary fibrosis. We previously identified interleukin (IL)-1beta as a major inducer of the PDGFR-alpha in rat pulmonary myofibroblasts in vitro. In this study, we report that staurosporine, a broad-spectrum kinase inhibitor, upregulates PDGFR-alpha gene expression and protein. A variety of other kinase inhibitors did not induce PDGFR-alpha expression. Staurosporine did not act via an IL-1beta autocrine loop because the IL-1 receptor antagonist protein did not block staurosporine-induced PDGFR-alpha expression. Furthermore, staurosporine did not activate a variety of signaling molecules that were activated by IL-1beta, including nuclear factor-kappaB, extracellular signal-regulated kinase, and c-Jun NH2-terminal kinase. However, both staurosporine- and IL-1beta-induced phosphorylation of p38 mitogen-activated protein kinase and upregulation of PDGFR-alpha by these two agents was inhibited by the p38 inhibitor SB-203580. Finally, staurosporine inhibited basal and PDGF-stimulated mitogenesis over the same concentration range that induced PDGFR-alpha expression. Collectively, these data demonstrate that staurosporine is a useful tool for elucidating the signaling mechanisms that regulate PDGFR expression in lung connective tissue cells and possibly for evaluating the role of the PDGFR-alpha as a growth arrest-specific gene.

Activation of ERK-1 and -2 by H(2)O(2) in a variety of cell types requires epidermal growth factor receptor (EGFR) phosphorylation. In this study, we investigated the activation of ERK by ONOO(-) in cultured rat lung myofibroblasts. Western blot analysis using anti-phospho-ERK antibodies along with an ERK kinase assay using the phosphorylated heat- and acid-stable protein (PHAS-1) substrate demonstrated that ERK activation peaked within 15 min after ONOO(-) treatment and was maximally activated with 100 micrometer ONOO(-). Activation of ERK by ONOO(-) and H(2)O(2) was blocked by the antioxidant N-acetyl-l-cysteine. Catalase blocked ERK activation by H(2)O(2), but not by ONOO(-), demonstrating that the effect of ONOO(-) was not due to the generation of H(2)O(2). Both H(2)O(2) and ONOO(-) induced phosphorylation of EGFR in Western blot experiments using an anti-phospho-EGFR antibody. However, the EGFR tyrosine kinase inhibitor AG1478 abolished ERK activation by H(2)O(2), but not by ONOO(-). Both H(2)O(2) and ONOO(-) activated Raf-1. However, the Raf inhibitor forskolin blocked ERK activation by H(2)O(2), but not by ONOO(-). The MEK inhibitor PD98059 inhibited ERK activation by both H(2)O(2) and ONOO(-). Moreover, ONOO(-) or H(2)O(2) caused a cytotoxic response of myofibroblasts that was prevented by preincubation with PD98059. In a cell-free kinase assay, ONOO(-) (but not H(2)O(2)) induced autophosphorylation and nitration of a glutathione S-transferase-MEK-1 fusion protein. Collectively, these data indicate that ONOO(-) activates EGFR and Raf-1, but these signaling intermediates are not required for ONOO(-)-induced ERK activation. However, MEK-1 activation is required for ONOO(-)-induced ERK activation in myofibroblasts. In contrast, H(2)O(2)-induced ERK activation is dependent on EGFR activation, which then leads to downstream Raf-1 and MEK-1 activation.

Vanadium pentoxide (V 2 O 5 ) is a cause of occupational asthma and chronic bronchitis, yet the molecular mechanisms through which V 2 O 5 exerts its effects on cell function are unclear. In this study we investigated the potential of V 2 O 5 to activate the extracellular signal‐regulated kinases 1 and 2 (ERK-1/2) in rat pulmonary myofibroblasts. Treatment of myofibroblasts with V 2 O 5 resulted in the activation of ERK-1/2, yet the inert metal titanium dioxide had no effect on ERK-1/2 activation. V 2 O 5 -induced ERK-1/2 activation was abolished by pretreatment with forskolin or PD98059, indicating a dependence on Raf and mitogen-activated protein (MAP) kinase kinase, respectively. Depletion of conventional protein kinase C activity with phorbol 12-myristate 13-acetate did not inhibit V 2 O 5 -induced ERK-1/2 activation. ERK-1/2 activation by V 2 O 5 was inhibited . 70% with the epidermal growth factor receptor (EGF-R) tyrosine kinase inhibitor AG1478. Phosphorylation of the 170-kD EGF-R by V 2 O 5 was detected after immunoprecipitation with an anti‐EGF-R antibody followed by phosphotyrosine Western blotting. V 2 O 5 strongly tyrosine-phosphorylated a 115-kD protein (p115) and activation of p115 was inhibited 60 to 70% by AG1478, indicating that this protein was an EGF-R substrate. Phosphorylation of p115 was also observed in EGF-stimulated cells. Immunoprecipitation of V 2 O 5 or EGF-treated cell lysates with an antibody against Src homology 2 protein tyrosine phosphatase (SH-PTP2) identified p115 as a SH-PTP2‐binding protein. Pretreatment of cells with the antioxidant N -acetyl- L -cysteine blocked V 2 O 5 -induced MAP kinase activation and p115 phosphorylation . 90%. These data suggest that V 2 O 5 activation of ERK-1/2 is oxidant-dependent and mediated through tyrosine phosphorylation of EGF-R and an EGF-R substrate which we identified as a 115-kD SH-PTP2‐binding protein. Metals are emerging as principal agents in air-pollution