Secretary leukocyte peptide inhibitor (SLPI) in pleural fluid is useful as a diagnostic marker of malignant pleural mesothelioma

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Background: There is no established diagnostic marker for malignant pleural mesothelioma (MPM). In particular, the differentiation from benign asbestos pleural effusion (BAPE) is challenging. Secretary leukocyte peptide inhibitor (SLPI) is an enzyme encoded by SLPI gene. SLPI gene is reported to be overexpressed in MPM cells. Methods: SLPI in pleural fluid was determined using Quantikine ELISA Human SLPI kit (R&D Systems). Results: Exploratory research revealed that SLPI value in pleural fluid of patients with MPM (n = 52) were significantly higher than those in lung cancer (LC) (n = 69) and BAPE (n = 50) ( P= 0.000). Prospective validation study included 12 pts of MPM, 24 pts of LC, 26 pts of BAPE. Median values of SLPI in MPM, LC, and BAPE were 159 .6 ng/ml, 90.5 ng/ml, and 43.2 ng/ml, respectively. SLPI value in patients with MPM were significantly higher than those in other groups ( P= 0.000). Receiver operating characteristics ROC) analysis was performed to examine the usefulness of differentiation of MPM and other diseases, and demonstrated that area under the curve (AUC) value was 0.758. With the cut of value of 88.6 ng/ml, the sensitivity was 83.3% and the specificity was 59.8%. Concerning the differentiation between MPM and BAPE, AUC value was 0.904 and with the cut of value of 81.8 ng/ml, the sensitivity was 83.3% and the specificity was 92.3%. Conclusions: Pleural fluid SLPI is a useful biomarker for the diagnosis of MPM, in particular, for the differentiation from BAPE.

The Role of Efferocytosis in Atherosclerosis

The necrotic core has long been a hallmark of the vulnerable atherosclerotic plaque. Although apoptotic cells are cleared quickly in almost all other tissue beds, their removal appears to be significantly impaired in the diseased blood vessel. Emerging evidence indicates that this phenomenon is caused by a defect in efferocytosis, the process by which apoptotic tissue is recognized for engulfment by phagocytic cells such as macrophages. Genetic and experimental data suggest that efferocytosis is impaired during atherogenesis caused by dysregulation of so-called eat me ligands, which govern the edibility of cells undergoing programmed cell death. The following is a summary of recent data indicating that efferocytosis is a major unappreciated driver of lesion expansion but also a reversible defect that can potentially be targeted as a means to prevent plaque progression.

Real-time visualization of cardiac cell beating behaviour on polymer diffraction gratings

Cardiotoxicity is a major adverse effect to pharmaceuticals. A new method to prepare optically sensitive substrates for measuring the beating of cardiac cells and their response to pharmaceuticals is reported.

The pathological features of idiopathic interstitial pneumonia-associated pulmonary adenocarcinomas

AIMS

To investigate the pathological features of idiopathic interstitial pneumonia (IIP)-associated pulmonary adenocarcinoma.

METHODS AND RESULTS

Surgically resected adenocarcinomas associated with IIP (the IIP group) and adenocarcinomas without IIP (the non-IIP group) were subjected to analysis. Adenocarcinomas in the IIP group were subdivided into two groups: one group included tumours connected to bronchiolar metaplasia in honeycomb lesions (the H-IIP group), and the other included tumours unrelated to honeycomb lesions (the NH-IIP group). Histomorphological appearance and immunohistochemical expression were compared among the H-IIP group, the NH-IIP group, and the non-IIP group. Most of the tumour cells in the H-IIP group had a tall, columnar shape that showed similar features to proximal bronchial epithelium, whereas tumour cells in the NH-IIP group and the non-IIP group had a club-like shape that showed similar features to respiratory bronchiolar/alveolar epithelium. Adenocarcinomas in the H-IIP group tended to be negative for thyroid transcription factor-1 (TTF-1) and positive for hepatocyte nuclear factor-4α (HNF-4α). The frequency of EGFR mutations was significantly lower in adenocarcinomas in the H-IIP group, although the frequencies of KRAS and ALK mutations did not differ among the three groups.

CONCLUSIONS

Idiopathic interstitial pneumonia-associated pulmonary adenocarcinomas, especially those arising from honeycomb lesions, have distinct pathological features.

A Histopathological Feature of EGFR-Mutated Lung Adenocarcinomas with Highly Malignant Potential - An Implication of Micropapillary Element

The purpose of this study was to define histological features determining the malignant potential of EGFR-mutated lung adenocarcinoma (LADC). Surgically resected tumors (EGFR-mutated LADCs with (21) and without (79) lymph node metastasis and EGFR wild-type LADCs with (26) and without (108) lymph node metastasis) and biopsy samples from inoperably advanced tumors (EGFR-mutated LADCs (78) and EGFR wild-type LADCs (99)) were examined. In surgically resected tumors, the EGFR-mutated LADCs with lymph node metastasis had the micropapillary element in a significantly greater proportion than others (Mann-Whitney tests P ≤0.026). The proportion of micropapillary element was higher in the EGFR-mutated LADC at the advanced stage (stage II, III, or IV) than in the tumor at the early stage (stage I) (Mann-Whitney test, P<0.0001). In the biopsy samples from inoperably advanced LADCs (177), EGFR-mutated tumors also had micropapillary element at a higher frequency than EGFR-wild type tumors (53/78 (68%), versus 30/99 (30%), Pearson x2 test, P<0.0001). In stage I EGFR-mutated LADCs (84), the tumors with the micropapillary element (34) exhibited a significantly higher recurrence rate than tumors without micropapillary element (50) (5-year Recurrence-free survival 64.4% versus 93.3%, log-rank test P = 0.028). The micropapillary element may be an exclusive determinant of malignant potential in EGFR-mutated LADC. It is suggested that EGFR-mutated LADC may develop through a distinct histogenesis, in which the micropapillary element is important for promoting progression.

A Triazinone Derivative Inhibits HIV-1 Replication by Interfering with Reverse Transcriptase Activity

A novel HIV-1 inhibitor, 6-(tert-butyl)-4-phenyl-4-(trifluoromethyl)-1H,3H-1,3,5-triazin-2-one (compound 1), was identified from a compound library screened for the ability to inhibit HIV-1 replication. EC₅₀ values of compound 1 were found to range from 107.9 to 145.4 nm against primary HIV-1 clinical isolates. In in vitro assays, HIV-1 reverse transcriptase (RT) activity was inhibited by compound 1 with an EC₅₀ of 4.3 μm. An assay for resistance to compound 1 selected a variant of HIV-1 with a RT mutation (RT^L100I ); this frequently identified mutation confers mild resistance to non-nucleoside RT inhibitors (NNRTIs). A recombinant HIV-1 bearing RT^L100I exhibited a 41-fold greater resistance to compound 1 than the wild-type virus. Compound 1 was also effective against HIV-1 with RT^K103N , one of the major mutations that confers substantial resistance to NNRTIs. Computer-assisted docking simulations indicated that compound 1 binds to the RT NNRTI binding pocket in a manner similar to that of efavirenz; however, the putative compound 1 binding site is located further from RT^K103 than that of efavirenz. Compound 1 is a novel NNRTI with a unique drug-resistance profile.

Sorafenib plus hepatic arterial infusion chemotherapy with cisplatin versus sorafenib for advanced hepatocellular carcinoma: randomized phase II trial

In a randomized phase II study of sorafenib plus hepatic arterial infusion chemotherapy with cisplatin in comparison with sorafenib alone in patients with advanced hepatocellular carcinoma, it yielded favorable overall survival when compared with sorafenib alone. This is the first report of its effectiveness in relation to the overall survival in comparison with that of sorafenib alone in patients with advanced hepatocellular carcinoma.

Background

Sorafenib (Sor) is acknowledged as a standard therapy for advanced hepatocellular carcinoma (HCC). This trial was conducted to evaluate the effect of addition of hepatic arterial infusion chemotherapy with cisplatin (SorCDDP) to Sor for the treatment of advanced HCC.

Patients and methods

We conducted a multicenter open-labeled randomized phase II trial in chemo-naïve patients with advanced HCC with Child-Pugh scores of 5–7. Eligible patients were randomly assigned 2:1 to receive SorCDDP (sorafenib: 400 mg bid; cisplatin: 65 mg/m², day 1, every 4–6 weeks) or Sor (400 mg bid). The primary end point was overall survival.

Results

A total of 108 patients were randomized (Sor, n = 42; SorCDDP, n = 66). The median survival in the Sor and SorCDDP arms were 8.7 and 10.6 months, respectively [stratified hazard ratio (95% confidence interval), 0.60 (0.38–0.96), P = 0.031]. The median time to progression and the response rate were, respectively, 2.8 months and 7.3% in the Sor arm and 3.1 months and 21.7% in the SorCDDP arm. The adverse events were more frequent in the SorCDDP arm than in the Sor arm, but well-tolerated.

Conclusion

SorCDDP yielded favorable overall survival when compared with Sor in patients with advanced HCC.

Clinical Trial registration

UMIN-CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number: UMIN000005703.

Liver stiffness measurement using acoustic radiation force impulse elastography in hepatitis C virus-infected patients with a sustained virological response

BACKGROUND

Acoustic radiation force impulse (ARFI) elastography is a non-invasive method for measuring liver stiffness. However, there are no reports evaluating the value of ARFI elastography for liver fibrosis in chronic hepatitis C patients with a sustained virological response (SVR).

AIM

To investigate the diagnostic performance of ARFI elastography for the assessment of liver fibrosis in hepatitis C virus (HCV) infected patients with an SVR.

METHODS

In this prospective study, we enrolled 336 patients: 121 HCV patients with an SVR (44.6% women) and 215 patients with HCV (47.9% women). ARFI elastography measurements of all patients were performed on the same day of liver biopsy.

RESULTS

The diagnostic accuracies, expressed as areas under the receiver operating characteristic curves for ARFI elastography, in HCV patients with an SVR and those in patients with HCV were 0.818 and 0.875 for the diagnosis of significant fibrosis (≥F2), 0.909 and 0.888 for the diagnosis of severe fibrosis (≥F3), and 0.981 and 0.890 for the diagnosis of liver cirrhosis (F4), respectively. The optimum cut-off values for ARFI elastography were 1.26 m/s for ≥F2, 1.31 m/s for ≥F3 and 1.49 m/s for F4 in HCV patients with an SVR. The liver stiffness values were lower in patients with SVR compared with those in patients with HCV at the same stage of fibrosis. The liver stiffness values were affected by the necroinflammatory activity and the time after SVR.

CONCLUSION

Acoustic radiation force impulse elastography is an acceptable method for predicting the severity of fibrosis in patients with hepatitis C virus and a sustained viral response.

Alterations in cathepsin L expression in lung cancers

We herein investigated the potential role of cathepsin L in lung carcinogenesis. Lung cancer cell lines and surgically resected tumors were examined for the expression of the cathepsin L protein and copy number alterations in its gene locus. Cathepsin L was stably expressed in bronchiolar epithelial cells. Neoplastic cells expressed cathepsin L at various levels, whereas its expression was completely lost in most of the lung cancer cell lines (63.6%, 7/11) examined. Furthermore, expression levels were lower in a large fraction of lung tumors (69.5%, 139/200) than in bronchiolar epithelia. The expression of cathepsin L was lost in some tumors (16.0%, 32/200). In adenocarcinomas, expression levels were significantly lower in high-grade tumors than in low-grade tumors (one-way ANOVA, P < 0.0500). Copy number alterations were found in 18.0% (36 [32 gain + 4 loss] /200) of lung tumors. No relationship existed between cathepsin L protein expression levels and the copy number of its gene locus (Spearman's rank-order correlation, P = 0.3096). Collectively, these results suggest that the down-regulated expression of cathepsin L, which is caused by an undefined mechanism other than copy number alterations, is involved in the progression of lung adenocarcinomas.

MicroRNA 139-5p coordinates APLNR-CXCR4 crosstalk during vascular maturation

G protein-coupled receptor (GPCR) signalling, including that involving apelin (APLN) and its receptor APLNR, is known to be important in vascular development. How this ligand–receptor pair regulates the downstream signalling cascades in this context remains poorly understood. Here, we show that mice with Apln, Aplnr or endothelial-specific Aplnr deletion develop profound retinal vascular defects, which are at least in part due to dysregulated increase in endothelial CXCR4 expression. Endothelial CXCR4 is negatively regulated by miR-139-5p, whose transcription is in turn induced by laminar flow and APLN/APLNR signalling. Inhibition of miR-139-5p in vivo partially phenocopies the retinal vascular defects of APLN/APLNR deficiency. Pharmacological inhibition of CXCR4 signalling or augmentation of the miR-139-5p-CXCR4 axis can ameliorate the vascular phenotype of APLN/APLNR deficient state. Overall, we identify an important microRNA-mediated GPCR crosstalk, which plays a key role in vascular development.

G protein-coupled receptors APLNR and CXCR4 are crucial for vascular development. Here, the authors show that these two signaling pathways communicate and that in response to blood flow APLNR signaling induces a decrease in CXCR4 expression via miR-139-5p, thereby restricting CXCR4 expression to the non-flow exposed tip cells in the retinal vasculature.

Expression of tropomyosins in lung cancer - a potential role in carcinogenesis and its utility in a histopathological diagnosis

We herein analyzed the relationships between tropomyosin protein expression levels and clinicopathological factors in order to determine the significance of tropomyosins in lung cancers. Although neoplastic cells expressed different isoforms of tropomyosin, overall expression levels were lower than those in bronchial and alveolar epithelial cells. In adenocarcinomas, tropomyosin levels were markedly reduced in poorly differentiated or solid subtype carcinomas, suggesting that a loss in the expression of tropomyosins is involved in the progression of lung adenocarcinomas. The potential utility of the immunohistochemical expression of tropomyosins for a histopathological diagnosis was also investigated. The sensitivity and specificity of a loss in the expression of tropomyosins were 100% and 50%, respectively, which were superior to those for the strong expression of p53 (sensitivity 100% and specificity 44%), a conventional biomarker. An immunohistochemical examination of tropomyosins may assist in the histopathological detection of lung cancer cells in small biopsy specimens.

Metallic ruthenium nanoparticles for hydrogenation of supercritical carbon dioxide

Metallic ruthenium nanoparticles prepared in a methyl alcohol solution under solvothermal conditions showed high activity for hydrogenation of supercritical carbon dioxide to formic acid.

A new complex alkali metal aluminium amide borohydride, Li2Al(ND2)4BH4: synthesis, thermal analysis and crystal structure

The first reported compound containing both [Al(ND₂)₄]⁻ and BH₄⁻ anions, Li₂Al(ND₂)₄BH₄, was formed in ball-milled LiAl(ND₂)₄ + 2LiBH₄ and NaAl(ND₂)₄ + 2LiBH₄. Its crystal structure was solved and refined in a monoclinic unit cell.

CDKN2B Regulates TGFβ Signaling and Smooth Muscle Cell Investment of Hypoxic Neovessels

RATIONALE

Genetic variation at the chromosome 9p21 cardiovascular risk locus has been associated with peripheral artery disease, but its mechanism remains unknown.

OBJECTIVE

To determine whether this association is secondary to an increase in atherosclerosis, or it is the result of a separate angiogenesis-related mechanism.

METHODS AND RESULTS

Quantitative evaluation of human vascular samples revealed that carriers of the 9p21 risk allele possess a significantly higher burden of immature intraplaque microvessels than carriers of the ancestral allele, irrespective of lesion size or patient comorbidity. To determine whether aberrant angiogenesis also occurs under nonatherosclerotic conditions, we performed femoral artery ligation surgery in mice lacking the 9p21 candidate gene, Cdkn2b. These animals developed advanced hindlimb ischemia and digital autoamputation, secondary to a defect in the capacity of the Cdkn2b-deficient smooth muscle cell to support the developing neovessel. Microarray studies identified impaired transforming growth factor β (TGFβ) signaling in cultured cyclin-dependent kinase inhibitor 2B (CDKN2B)-deficient cells, as well as TGFβ1 upregulation in the vasculature of 9p21 risk allele carriers. Molecular signaling studies indicated that loss of CDKN2B impairs the expression of the inhibitory factor, SMAD-7, which promotes downstream TGFβ activation. Ultimately, this manifests in the upregulation of a poorly studied effector molecule, TGFβ1-induced-1, which is a TGFβ-rheostat known to have antagonistic effects on the endothelial cell and smooth muscle cell. Dual knockdown studies confirmed the reversibility of the proposed mechanism, in vitro.

CONCLUSIONS

These results suggest that loss of CDKN2B may not only promote cardiovascular disease through the development of atherosclerosis but may also impair TGFβ signaling and hypoxic neovessel maturation.

The potential role of microRNA-31 expression in early colorectal cancer

The expression of microRNA-31 (miR-31) has been implicated in the progression of some human malignancies including colorectal cancer. However, the clinical significance of the expression of miR-31 in submucosally invasive (T1) colorectal cancer remains unclear. The aim of the present study was to delineate the relationship between clinicopathological features and the oncogenic modulator miR-31 in submucosally invasive colorectal cancer. We investigated the expression of miR-31 in 50 submucosally invasive colorectal cancer specimens, along with the corresponding non-tumoral mucosa specimens, using a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The relationships between miR-31 expression levels and clinicopathological characteristics were assessed. The miR-31 host gene locus was investigated using fluorescence in situ hybridization. qRT-PCR revealed that the expression of miR-31 was higher in colorectal cancer tissue than in non-tumoral tissue (P = 0.0002). The up-regulated expression of miR-31 may play an oncogenic role in the early stage of carcinogenesis in colorectal cancers.

Identification of Novel Recombinant Forms of Hepatitis B Virus Generated from Genotypes Ae and G in HIV-1-Positive Japanese Men Who Have Sex with Men

The rare hepatitis B virus (HBV) genotype G (HBV/G) coinfects HIV-1-positive individuals along with HBV/A and generates recombinants. However, the circulation of HBV A/G recombinants remains poorly understood. This molecular epidemiologic study examined HBV A/G recombinants in Japanese HIV-1-positive men who have sex with men (MSM). Initially, blood specimens submitted for confirmatory tests of HIV infection in Osaka and Tokyo, Japan, from 2006 to 2013 were examined for HIV-1, and HIV-1-positive specimens were screened for HBV. Among 817 specimens from HIV-1-positive individuals, HBsAg was detected in 59 specimens; of these, HBV/Ae (alternatively A2), a subgenotype of HBV/A prevalent in Europe and North America, was identified in 70.2%, HBV/C in 17.5%, and HBV/G in 10.5%, and HBV/E in 1.8% according to the core gene sequence. The full-length genome analysis of HBV was performed on HBV/G-positive specimens because some HBV A/G recombinants were historically overlooked by genotyping based on a partial genome analysis. It revealed that five of the specimens contained novel Ae/G recombinants, the core gene of which had a high sequence similarity to HBV/G. Detailed analyses showed that novel recombinants were coinfected with HBV/Ae in a recombinant-dominant fashion. No major drug-resistant mutations were found in the newly identified HBV Ae/G recombinants. Some of the individuals asymptomatically coinfected with HIV/HBV suffered mild liver injury. This study demonstrated that novel Ae/G HBV recombinants were identified in Japanese HIV-1-positive MSM. The pathogenicity of novel HBV Ae/G recombinants should be examined in a future longitudinal study. Surveillance of such viruses in HIV-1-positive individuals should be emphasized.

Abstract 38: Cyclin-Dependent Kinase Inhibitor 2B Regulates Transforming Growth Factor Beta 1 Mediated Smooth Muscle Cell Recruitment to Ischemic Blood Vessels

Peripheral artery disease (PAD) is a highly morbid condition affecting nearly 8.5 million Americans. Genome wide association studies (GWAS) have identified genetic variation at the chromosome 9p21 cardiovascular risk locus as an important source of heritable PAD risk. However, it is unknown whether this association is secondary to an increase in atherosclerosis or is the result of a separate angiogenesis-related mechanism.

Quantitative ultrastructural evaluation of human plaque laden vascular samples revealed that carriers of the 9p21 risk allele displayed a significantly increased burden of immature intraplaque microvessels than carriers of the ancestral allele. To determine whether this process occurs under non-atherosclerotic conditions, we performed femoral artery ligation surgery in mice lacking Cdkn2b; a candidate gene we previously identified to have reduced expression in human carriers of the 9p21 risk allele. These animals developed advanced hind-limb ischemia and digital auto-amputation, relative to wild-type controls. Interestingly, in situ and in vitro hypoxic assays identified this defect to be a consequence of pro-angiogenic behavior displayed by CDKN2B deficient endothelial cells (EC) and impaired smooth muscle cell (SMC) recruitment to the developing neovessel. Exploratory microarray studies performed to identify the mechanism involved, revealed that TGFβ1 signaling is significantly induced in cultured CDKN2B -deficient cells; a finding later confirmed in the vasculature of individuals carrying the 9p21 risk allele. Subsequent molecular signaling studies reveal this increase to be a result of impaired expression of the inhibitory factor, SMAD-7. Increased TGFβ1 signaling was ultimately found to manifest the upregulation of a poorly studied effector molecule, TGFβ1-induced-1, which is a TGFβ-‘rheostat’ known to have antagonistic effects on the EC and SMC. Dual knockdown and rescue studies confirmed the reversibility of the proposed mechanism, in vitro.

Taken together these findings suggest that loss of CDKN2B may not only promote cardiovascular disease through the development of atherosclerosis, but may also impair TGFβ1 signaling and hypoxic neovessel maturation consequently resulting in PAD.

Diffuse Liver Metastasis of Small-Cell Lung Cancer Presenting as Acute Liver Failure and Diagnosed by Transjugular Liver Biopsy: A Rare Case in Whom Nodular Lesions Were Detected by Enhanced CT Examination

Small-cell lung cancer (SCLC) is a subgroup of lung cancer with a high frequency of liver metastasis, which is a predictor of poor prognosis. Diffuse liver metastases of SCLC with no visible nodular lesions in the liver when examined using computed tomography (CT) are relatively rare; however, a few cases with rapid progression to acute liver failure that were diagnosed after death have been reported. In this paper, we report a 63-year-old man with diffuse liver metastases of SCLC that were histologically diagnosed using a transjugular liver biopsy while the patient was alive, even though no lesions were visible during a contrast-enhanced CT examination.

Species differences in the metabolism of ritobegron in vitro and assessment of potential interactions with transporters and cytochrome P450 enzymes

Ritobegron, a selective β3-adrenoceptor agonist, is the prodrug of the active compound, KUC-7322. We investigated species differences in its metabolism in vitro and the potential for drug-drug interactions with ritobegron. In rat, dog, monkey, and human liver microsomes, ritobegron was not metabolized by cytochrome P450 enzymes (CYPs). KUC-7322 was the only metabolite observed. Hydrolysis of ritobegron to KUC-7322 was likely catalyzed by carboxylesterases in human liver microsomes. The maximum velocity of the reaction (V(max))/Michaelis-Menten constant (K(m)) for hydrolysis of ritobegron to KUC-7322 was much higher in rat serum than those in other species. There were also species differences in the conjugation of KUC-7322. Sulfate conjugates of ritobegron were detected in all species, whereas glucuronide and glutathione conjugates of KUC-7322 were only observed in rat liver subcellular fractions. Ritobegron and KUC-7322 did not affect the CYP-mediated metabolism of probe substrates in human liver microsomes and organic anion transporter 1 (OAT1)-, OAT2-, OAT3-, organic cation transporter 2 (OCT-2)-, OCT3-, or organic cation/carnitine transporter 1 (OCTN1)-mediated uptake of probe substrates in S2 cells. Ritobegron, but not KUC-7322, inhibited P-glycoprotein-mediated digoxin transport in Caco-2 cells. Significant uptake of KUC-7322 was observed in OAT3-expressing S2 cells. Therefore, CYP-mediated drug-drug interactions are not likely when ritobegron is administered with CYP substrates or inhibitors. Ritobegron may increase the plasma concentrations of P-glycoprotein substrates, such as digoxin, and the plasma concentration of KUC-7322 may increase when it is administered in combination with OAT inhibitors such as probenecid.

Oxido-reductive regulation of vascular remodeling by receptor tyrosine kinase ROS1

Angioplasty and stenting is the primary treatment for flow-limiting atherosclerosis; however, this strategy is limited by pathological vascular remodeling. Using a systems approach, we identified a role for the network hub gene glutathione peroxidase-1 (GPX1) in pathological remodeling following human blood vessel stenting. Constitutive deletion of Gpx1 in atherosclerotic mice recapitulated this phenotype of increased vascular smooth muscle cell (VSMC) proliferation and plaque formation. In an independent patient cohort, gene variant pair analysis identified an interaction of GPX1 with the orphan protooncogene receptor tyrosine kinase ROS1. A meta-analysis of the only genome-wide association studies of human neointima-induced in-stent stenosis confirmed the association of the ROS1 variant with pathological remodeling. Decreased GPX1 expression in atherosclerotic mice led to reductive stress via a time-dependent increase in glutathione, corresponding to phosphorylation of the ROS1 kinase activation site Y2274. Loss of GPX1 function was associated with both oxidative and reductive stress, the latter driving ROS1 activity via s-glutathiolation of critical residues of the ROS1 tyrosine phosphatase SHP-2. ROS1 inhibition with crizotinib and deglutathiolation of SHP-2 abolished GPX1-mediated increases in VSMC proliferation while leaving endothelialization intact. Our results indicate that GPX1-dependent alterations in oxido-reductive stress promote ROS1 activation and mediate vascular remodeling.