A Phase Ib Study of the Dual PI3K/mTOR Inhibitor Dactolisib (BEZ235) Combined with Everolimus in Patients with Advanced Solid Malignancies

Abstract

Background

The combination of everolimus and the imidazoquinoline derivative, BEZ235 (dactolisib), a dual PI3K/mTOR inhibitor, demonstrated synergy in a preclinical model.

Objective

To establish clinical feasibility, a phase Ib dose-escalation trial investigating safety and pharmacokinetics of this combination in patients with advanced tumors was performed.

Patients and Methods

BEZ235 was orally administered daily in escalating doses of 200, 400, and 800 mg along with everolimus at 2.5 mg daily in 28-day cycles. Nineteen patients were enrolled. Adverse events and tumor responses were evaluated using CTCAE v4.0 and RECIST 1.1, respectively. Pharmacokinetic analyses were performed.

Results

Common toxicities observed included fatigue, diarrhea, nausea, mucositis, and elevated liver enzymes. No confirmed responses were observed. BEZ235 pharmacokinetics exhibited dose-proportional increases in C_max and AUC_0-24 over the three doses, with high inter-individual variability. Non-compartmental and population pharmacokinetic-based simulations indicated significant increases in everolimus C_max and AUC_0-24 on day 28 and decreased clearance to 13.41 L/hr.

Conclusions

The combination of BEZ235 and everolimus demonstrated limited efficacy and tolerance. BEZ235 systemic exposure increased in a dose-proportional manner while oral bioavailability was quite low, which may be related to gastrointestinal-specific toxicity. The changes in steady-state pharmacokinetics of everolimus with BEZ235 highlight potential drug–drug interactions when these two drugs are administered together.

Clinicaltrials.gov: NCT01508104

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Gemcitabine in Combination with a Second Cytotoxic Agent in the First-Line Treatment of Locally Advanced or Metastatic Pancreatic Cancer: a Systematic Review and Meta-Analysis

Abstract

Background

It remains controversial whether the addition of a second cytotoxic agent can further improve the therapeutic effect of gemcitabine monotherapy in advanced or metastatic pancreatic cancer (LA/MPC).

Objective

The objective of the present systematic review and meta-analysis was to investigate the efficacy and safety of gemcitabine-based doublet chemotherapy regimens compared to single-agent gemcitabine in the first-line treatment of unresectable LA/MPC.

Methods

We searched for randomized controlled trials (RCTs) of gemcitabine monotherapy versus gemcitabine in combination with a second cytotoxic agent in patients with LA/MPC. The last search date was December 31, 2016.

Results

Twenty-seven RCTs were identified and included in the present systematic review and meta-analysis, involving a total of 7343 patients. The meta-analysis showed that gemcitabine-based combination therapy significantly improved overall survival (OS) (HR: 0.89; 95% confidence interval (CI): 0.85-0.94; P < 0.0001), progression-free survival (PFS) (HR: 0.80; 95% CI: 0.73-0.88; P < 0.0001), and overall response rate (ORR) (RR: 1.83; 95% CI: 1.62-2.07; P < 0.0001) in comparison to single-agent gemcitabine. Subgroup analysis suggested that the antitumor activity differed between gemcitabine-based combination regimens: doublet regimens of gemcitabine plus a taxoid, and gemcitabine plus a fluoropyrimidine, in particular an oral fluoropyrimidine, resulted in a significant OS benefit for the patients. However, the combination of gemcitabine with other cytotoxic agents, such as platinum compounds or topoisomerase inhibitors failed to reduce the mortality risk. Combination therapy caused more grade 3/4 toxicities, including neutropenia, thrombocytopenia, vomiting, diarrhea, and fatigue.

Conclusions

Gemcitabine-based doublet regimens demonstrated superiority over gemcitabine monotherapy in overall efficacy, but were associated with increased toxicity. Different gemcitabine-based combinations showed different antitumor activity, and doublet regimens of gemcitabine in combination with a taxoid or a fluoropyrimidine, in particular an oral fluoropyrimidine provided significant survival benefits in the first-line treatment of unresectable LA/MPC.

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Effect of Ongoing Assessment of Resident Operative Autonomy on the Operating Room Environment

Publication date: Available online 28 March 2017
Source:Journal of Surgical Education
Author(s): Jonathan P. Fryer, Ezra N. Teitelbaum, Brian C. George, Mary C. Schuller, Shari L. Meyerson, Christina M. Theodorou, Joseph Kang, Amy Yang, Lihui Zhao, Debra A. DaRosa
ObjectiveWe have previously demonstrated the feasibility and validity of a smartphone-based system called Procedural Autonomy and Supervision System (PASS), which uses the Zwisch autonomy scale to facilitate assessment of the operative performances of surgical residents and promote progressive autonomy. To determine whether the use of PASS in a general surgery residency program is associated with any negative consequences, we tested the null hypothesis that PASS implementation at our institution would not negatively affect resident or faculty satisfaction in the operating room (OR) nor increase mean OR times for cases performed together by residents and faculty.MethodsMean OR times were obtained from the electronic medical record at Northwestern Memorial Hospital for the 20 procedures most commonly performed by faculty members with residents before and after PASS implementation. OR times were compared via two-sample t-test. The OR Educational Environment Measure tool was used to assess OR satisfaction with all clinically active general surgery residents (n = 31) and full-time general surgery faculty members (n = 27) before and after PASS implementation. Results were compared using the Mann-Whitney rank sum test.ResultsA significant prolongation in mean OR time between control and study period was found for only 1 of the 20 operative procedures performed at least 20 times by participating faculty members with residents. Based on the overall survey score, no significant differences were found between resident and faculty responses to the OR Educational Environment Measure survey before and after PASS implementation. When individual survey items were compared, while no differences were found with resident responses, differences were noted with faculty responses for 7 of the 35 items addressed although after Bonferroni correction none of these differences remained significant.ConclusionsOur data suggest that PASS does not increase mean OR times for the most commonly performed procedures. Resident OR satisfaction did not significantly change during PASS implementation, whereas some changes in faculty satisfaction were noted suggesting that PASS implementation may have had some negative effect with them. Although the effect on faculty satisfaction clearly requires further investigation, our findings support that use of an autonomy-based OR performance assessment system such as PASS does not appear to have a major negative influence on OR times nor OR satisfaction.



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Assessment of Female Medical Students’ Interest in Careers in Cardiothoracic Surgery

Publication date: Available online 28 March 2017
Source:Journal of Surgical Education
Author(s): Darci C. Foote, James M. Meza, Vikram Sood, Rishindra M. Reddy
ObjectiveAlthough over half of medical students are females, women comprise only 21% of cardiothoracic (CT) surgery residency applicants and 5% of the CT workforce. We sought to gain insight into female medical students' perceptions of CT surgery and identify targets to increase interest.DesignA 33-question survey queried career selection factors, perceptions of CT surgery, and ways to increase interest in the field. Responses were stratified by sex and preclinical versus clinical years.SettingWomen at 13 US medical schools were compared to men at a Midwest medical school.ParticipantsSurveys were distributed to approximately 4400 women and were completed by 372 (8.5%) women. Comparison surveys were distributed to approximately 170 preclinical men and were completed by 98 (57.6%) men.ResultsPreclinical woman had broad interests, whereas clinical women were more interested in primary care (p = 0.0124). Intellectual interest and lifestyle were important in specialty selection for men and women (91% versus 90%; 78% versus 86%). Although preclinical men valued perceived prestige and salary significantly more than preclinical women (39% versus 20%, p = 0.0014; 64% versus 48%, p = 0.0173), preclinical women valued caring for specific ethnicities and addressing health disparities significantly more than preclinical men (26% versus 15%, p = 0.0173; 53% versus 33%, p = 0.0019). Making family plans was cited by 83% of women as difficult if they choose to become a CT surgeon. Women thought that attaining their career interests and life goals (76%) or access to female CT surgery mentors (63%) would make the field more appealing. Over 70% of preclinical women were interested in shadowing a CT surgeon. Of these women, 12% attempted to shadow.ConclusionsAlthough baseline interest in CT surgery is low among women, there are many targets for increasing interest especially during preclinical years. Residency programs have the opportunity to entice women to the field by addressing their priorities of lifestyle, family planning, and addressing health disparities.



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Variable Operative Experience in Hand Surgery for Plastic Surgery Residents

Publication date: Available online 29 March 2017
Source:Journal of Surgical Education
Author(s): Jason Silvestre, Ines C. Lin, Lawrence Scott Levin, Benjamin Chang
BackgroundEfforts to standardize hand surgery training during plastic surgery residency remain challenging. We analyze the variability of operative hand experience at U.S. plastic surgery residency programs.MethodsOperative case logs of chief residents in accredited U.S. plastic surgery residency programs were analyzed (2011-2015). Trends in fold differences of hand surgery case volume between the 10th and 90th percentiles of residents were assessed graphically. Percentile data were used to calculate the number of residents achieving case minimums in hand surgery for 2015.ResultsCase logs from 818 plastic surgery residents were analyzed of which a minority were from integrated (35.7%) versus independent/combined (64.3%) residents. Trend analysis of fold differences in case volume demonstrated decreasing variability among procedure categories over time. By 2015, fold differences for hand reconstruction, tendon cases, nerve cases, arthroplasty/arthrodesis, amputation, arterial repair, Dupuytren release, and neoplasm cases were below 10-fold. Congenital deformity cases among independent/combined residents was the sole category that exceeded 10-fold by 2015. Percentile data suggested that approximately 10% of independent/combined residents did not meet case minimums for arterial repair and congenital deformity in 2015.ConclusionsVariable operative experience during plastic surgery residency may limit adequate exposure to hand surgery for certain residents. Future studies should establish empiric case minimums for plastic surgery residents to ensure hand surgery competency upon graduation.



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Country-level predictors of vaccination coverage and inequalities in Gavi-supported countries

Publication date: Available online 29 March 2017
Source:Vaccine
Author(s): Catherine Arsenault, Mira Johri, Arijit Nandi, José M. Mendoza Rodríguez, Peter M. Hansen, Sam Harper
BackgroundImportant inequalities in childhood vaccination coverage persist between countries and population groups. Understanding why some countries achieve higher and more equitable levels of coverage is crucial to redress these inequalities. In this study, we explored the country-level determinants of (1) coverage of the third dose of diphtheria-tetanus-pertussis- (DTP3) containing vaccine and (2) within-country inequalities in DTP3 coverage in 45 countries supported by Gavi, the Vaccine Alliance.MethodsWe used data from the most recent Demographic and Health Surveys (DHS) conducted between 2005 and 2014. We measured national DTP3 coverage and the slope index of inequality in DTP3 coverage with respect to household wealth, maternal education, and multidimensional poverty. We collated data on country health systems, health financing, governance and geographic and sociocultural contexts from published sources. We used meta-regressions to assess the relationship between these country-level factors and variations in DTP3 coverage and inequalities. To validate our findings, we repeated these analyses for coverage with measles-containing vaccine (MCV).ResultsWe found considerable heterogeneity in DTP3 coverage and in the magnitude of inequalities across countries. Results for MCV were consistent with those from DTP3. Political stability, gender equality and smaller land surface were important predictors of higher and more equitable levels of DTP3 coverage. Inequalities in DTP3 coverage were also lower in countries receiving more external resources for health, with lower rates of out-of-pocket spending and with higher national coverage. Greater government spending on heath and lower linguistic fractionalization were also consistent with better vaccination outcomes.ConclusionImproving vaccination coverage and reducing inequalities requires that policies and programs address critical social determinants of health including geographic and social exclusion, gender inequality and the availability of financial protection for health. Further research should investigate the mechanisms contributing to these associations.



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Editorial Board/Aims and Scope

Publication date: 11 April 2017
Source:Vaccine, Volume 35, Issue 16





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Sociodemographic predictors of variation in coverage of the national shingles vaccination programme in England, 2014/15

Publication date: Available online 28 March 2017
Source:Vaccine
Author(s): Charlotte Ward, Lisa Byrne, Joanne M. White, Gayatri Amirthalingam, Karen Tiley, Michael Edelstein
IntroductionIn September 2013, England introduced a shingles vaccination programme to reduce incidence and severity of shingles in the elderly. This study aims to assess variation in vaccine coverage with regards to selected sociodemographic factors to inform activities for improving equity of the programme.MethodsEligible 70year-olds were identified from a national vaccine coverage dataset in 2014/15 that includes 95% of GPs in England. NHS England Local Team (LT) and index of multiple deprivation (IMD) scores were assigned to patients based on GP-postcode. Vaccine coverage (%) with 95% confidence intervals (CIs), were calculated overall and by LT, ethnicity and IMD, using binomial regression.ResultsOf 502,058 eligible adults, 178,808 (35.6%) had ethnicity recorded. Crude vaccine coverage was 59.5% (95%CI: 59.3–59.7). Coverage was lowest in London (49.6% coverage, 95%CI: 49.0–50.2), and compared to this coverage was significantly higher in all other LTs (+6.3 to +10.4, p<0.001) after adjusting for ethnicity and IMD. Coverage decreased with increasing deprivation and was 8.2% lower in the most deprived (95%CI: 7.3–9.1) compared with the least deprived IMD quintile (64.1% coverage, 95%CI: 63.6–64.6), after adjustment for ethnicity and LT. Compared with White-British (60.7% coverage, 95%CI: 60.5–61.0), other ethnic groups had between 4.0% (Indian) and 21.8% (Mixed: White and Black African) lower coverage. After adjusting for IMD and LT, significantly lower coverage by ethnicity persisted in all groups, except in Mixed: Other, Indian and Bangladeshi compared with White-British.ConclusionsAfter taking geography and deprivation into account, shingles vaccine coverage varied by ethnicity. White-British, Indian and Bangladeshi groups had highest coverage; Mixed: White and Black African, and Black-other ethnicities had the lowest. Patients' ethnicity and IMD are predictors of coverage which contribute to, but do not wholly account for, geographical variation coverage. Interventions to address service-related, sociodemographic and ethnic inequalities in shingles vaccine coverage are required.



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A different scintigraphic approach to evaluate the glomerular filtration rate

Publication date: Available online 29 March 2017
Source:Revista Española de Medicina Nuclear e Imagen Molecular
Author(s): T. Haciosmanoglu, A.O. Karacalioglu, T. Eyileten, S. Ince, N. Arslan
ObjectiveMultiple nuclear medicine techniques for measuring renal glomerular filtration rate (GFR) are available but some of them are not practical in daily routine use and others have some accuracy issues. Hence the aim of the study was to design a new camera-based approach to measure the GFR and to compare our results with other measured GFR (mGFR) and estimated GFRs (eGFRs) derived from available measurements and equations used in daily clinical practice.Material and methods34 patients were included in the study. ∼74MBq (2mCi) Technetium 99m diethylene-triamine-pentaacetic acid (^99mTc-DTPA) was administered to the patients during 5min. A simple formula based on a dilution principle was used to measure GFR (ScinGFR).ResultsOur formula provided similar mGFR results in narrower range as creatinine clearance did and our results correlated well with results derived from other equations. When ScinGFR values were compared to others, there was a significant difference among them (p=0.031) due to difference between the ScinGFR and Cockroft–Gault. When the results of the ScinGFR compared to others without Cockroft-Gault, the difference among them was not significant (p=0.164).ConclusionA simple formula considering the extracellular fluid volume was used to predict the split and global kidney functions and despite some discrepancies, good correlation among our results and those derived from available formulas was detected.



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Definition: Apraxia

Publication date: Available online 29 March 2017
Source:Cortex
Author(s): Roberto Cubelli




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In search of a shared language in neuropsychology

Publication date: Available online 29 March 2017
Source:Cortex
Author(s): Roberto Cubelli, Sergio Della Sala




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Definition: Limb Apraxia

Publication date: Available online 29 March 2017
Source:Cortex
Author(s): François Osiurak, Yves Rossetti




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Pulsed Low Dose Rate Radiation With Concurrent Chemotherapy for Non-Small Cell Lung Cancer and Esophageal Cancer

Conditions:   Lung Cancer;   Esophageal Cancer
Interventions:   Radiation: Pulsed Low Dose Radiation;   Drug: Carboplatin;   Drug: Paclitaxel
Sponsor:   Fox Chase Cancer Center
Recruiting - verified March 2017

http://ift.tt/2oyEbs8

Observation Study of Patients With Non-Small Cell Lung Cancer and Esophageal Cancer Treated With Chemo-Radiation Followed by Surgery

Conditions:   Lung Cancer;   Esophageal Cancer
Interventions:   Drug: Carboplatin;   Drug: Paclitaxel;   Radiation: Radiation Therapy
Sponsor:   Fox Chase Cancer Center
Recruiting - verified March 2017

http://ift.tt/2obdGNk

Robot-assisted Thoraco-laparoscopic Esophagectomy Versus Minimally Invasive Conventional Thoraco-laparoscopic Esophagectomy

Conditions:   Esophageal Cancer;   Esophageal Carcinoma
Interventions:   Procedure: esophagectomy;   Procedure: esophagectomy
Sponsor:   Zhiang Li
Not yet recruiting - verified March 2017

http://ift.tt/2oyWMUR

Stop or Go? Endosome Positioning in the Establishment of Compartment Architecture, Dynamics, and Function

Publication date: Available online 28 March 2017
Source:Trends in Cell Biology
Author(s): Jacques Neefjes, Marlieke M.L. Jongsma, Ilana Berlin
The endosomal system constitutes a key negotiator between the environment of a cell and its internal affairs. Comprised of a complex membranous network, wherein each vesicle can in principle move autonomously throughout the cell, the endosomal system operates as a coherent unit to optimally face external challenges and maintain homeostasis. Our appreciation of how individual endosomes are controlled in time and space to best serve their collective purpose has evolved dramatically in recent years. In light of these efforts, the endoplasmic reticulum (ER) – with its expanse of membranes permeating the cytoplasmic space – has emerged as a potent spatiotemporal organizer of endosome biology. We review the latest advances in our understanding of the mechanisms underpinning endosomal transport and positioning, with emphasis on the contributions from the ER, and offer a perspective on how the interplay between these aspects shapes the architecture and dynamics of the endosomal system and drives its myriad cellular functions.



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The Endoplasmic Reticulum: A Hub of Protein Quality Control in Health and Disease

Publication date: Available online 29 March 2017
Source:Free Radical Biology and Medicine
Author(s): Lisa Vincenz-Donnelly, Mark S. Hipp
One third of the eukaryotic proteome is synthesized at the endoplasmic reticulum (ER), whose unique properties provide a folding environment substantially different from the cytosol. A healthy, balanced proteome in the ER is maintained by a network of factors referred to as the ER quality control (ERQC) machinery. This network consists of various protein folding chaperones and modifying enzymes, and is regulated by stress response pathways that prevent the build-up as well as the secretion of potentially toxic and aggregation-prone misfolded protein species. Here, we describe the components of the ERQC machinery, investigate their response to different forms of stress, and discuss the consequences of ERQC break-down.

Graphical abstract

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Heme modulates Trypanosoma cruzi bioenergetics inducing mitochondrial ROS production

Publication date: Available online 29 March 2017
Source:Free Radical Biology and Medicine
Author(s): Natália P Nogueira, Francis MS Saraiva, Matheus P Oliveira, Ana Paula M Mendonça, Job D.F. Inacio, Elmo E Almeida-Amaral, Rubem F Menna-Barreto, Gustavo AT Laranja, Eduardo J Lopes Torres, Marcus F Oliveira, Marcia C Paes
Trypanosoma cruzi is the causative agent of Chagas disease and has a single mitochondrion, an organelle responsible for ATP production and the main site for the formation of reactive oxygen species (ROS). T. cruzi is an obligate intracellular parasite with a complex life cycle that alternates between vertebrate and invertebrate hosts, therefore the development of survival strategies and morphogenetic adaptations to deal with the various environments is mandatory. Over the years our group has been studying the vector-parasite interactions using heme as a physiological oxidant molecule that triggered epimastigote proliferation however, the source of ROS induced by heme remained unknown. In the present study we demonstrate the involvement of heme in the parasite mitochondrial metabolism, decreasing oxygen consumption leading to increased mitochondrial ROS and membrane potential. First, we incubated epimastigotes with carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), an uncoupler of oxidative phosphorylation, which led to decreased ROS formation and parasite proliferation, even in the presence of heme, correlating mitochondrial ROS and T. cruzi survival. This hypothesis was confirmed after the mitochondria-targeted antioxidant ((2-(2,2,6,6 Tetramethylpiperidin-1-oxyl-4-ylamino)−2-oxoethyl) triphenylphosphonium chloride (MitoTEMPO) decreased both heme-induced ROS and epimastigote proliferation. Furthermore, heme increased the percentage of tetramethylrhodamine methyl ester (TMRM) positive parasites tremendously-indicating the hyperpolarization and increase of potential of the mitochondrial membrane (ΔΨm). Assessing the mitochondrial functional metabolism, we observed that in comparison to untreated parasites, heme-treated epimastigotes decreased their oxygen consumption, and increased the complex II-III activity. These changes allowed the electron flow into the electron transport system, even though the complex IV (cytochrome c oxidase) activity decreased significantly, showing that heme-induced mitochondrial ROS appears to be a consequence of the enhanced mitochondrial physiological modulation. Finally, the parasites that were submitted to high concentrations of heme presented no alterations in the ultrastructure. Consequently, our results suggest that heme released by the insect vector after the blood meal, modify epimastigote mitochondrial physiology to increase ROS as a metabolic mechanism to maintain epimastigote survival and proliferation.

Graphical abstract

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Methylglyoxal-induced AMPK activation leads to autophagic degradation of thioredoxin 1 and glyoxalase 2 in HT22 nerve cells

Publication date: Available online 29 March 2017
Source:Free Radical Biology and Medicine
Author(s): Alcir Luiz Dafre, Ariana Ern Schmitz, Pamela Maher
Methylglyoxal (MGO) is a major glycating agent that reacts with basic residues of proteins and promotes the formation of advanced glycation end products which are believed to play key roles in a number of pathologies, such as diabetes, Alzheimer's disease, and inflammation. We previously showed that MGO treatment targets the thioredoxin and the glyoxalase systems, leading to a decrease in Trx1 and Glo2 proteins in immortalized mouse hippocampal HT22 nerve cells. Here, we propose that autophagy is the underlying mechanism leading to Glo2 and Trx1 loss induced by MGO. The autophagic markers p62, and the lipidated and active form of LC3, were increased by MGO (0.5mM). Autophagy inhibition with bafilomycin or chloroquine prevented the decrease in Trx1 and Glo2 at 6 and 18h after MGO treatment. Proteasome inhibition by MG132 exacerbated the effect of MGO on Trx1 and Glo2 degradation (18h), further suggesting a role for autophagy. ATG5 small interfering RNA protected Trx1 and Glo2 from MGO-induced degradation, confirming Trx1 and Glo2 loss is mediated by autophagy. In the search for the signals that control autophagy, we found that AMPK activation, a known autophagy inducer, was markedly increased by MGO treatment. AMPK activation was confirmed by increased acetyl coenzyme A carboxylase phosphorylation, a direct AMPK substrate and by decreased mTOR phosphorylation, an indirect marker of AMPK activation. To confirm that MGO-mediated Trx1 and Glo2 degradation was AMPK-dependent, AMPK-deficient mouse embryonic fibroblasts (MEFs) were treated with MGO. Wildtype MEFs presented the expected decrease in Trx1 and Glo2, while MGO was ineffective in decreasing these proteins in AMPK-deficient cells. Overall, the data indicate that MGO activates autophagy in an AMPK-dependent manner, and that autophagy was responsible for Trx1 and Glo2 degradation, confirming that Trx1 and Glo2 are molecular targets of MGO.

Graphical abstract

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Zinc Regulates Nox1 Expression Through a NF-κB and Mitochondrial ROS Dependent Mechanism to Induce Senescence of Vascular Smooth Muscle Cells

Publication date: Available online 29 March 2017
Source:Free Radical Biology and Medicine
Author(s): G. Salazar, J. Huang, R.G. Feresin, Y. Zhao, K.K. Griendling
AimsThe role of oxidative stress and inflammation in the development and progression of cardiovascular diseases (CVD) is well established. Increases in oxidative stress can further exacerbate the inflammatory response and lead to cellular senescence. We previously reported that angiotensin II (Ang II) and zinc increase reactive oxygen species (ROS) and cause senescence of vascular smooth muscle cells (VSMCs) and that senescence induced by Ang II is a zinc-dependent process. Zinc stimulated NADPH oxidase (Nox) activity; however, the role of Nox isoforms in zinc effects was not determined.ResultsHere, we show that downregulation of Nox1, but not Nox4, by siRNA prevented both Ang II- and zinc-induced senescence in VSMCs. On the other hand, overexpression of Nox1 induced senescence, which was associated with reduced proliferation, reduced expression of telomerase and increased DNA damage. Zinc increased Nox1 protein expression, which was inhibited by chelation of zinc with TPEN and by overexpression of the zinc exporters ZnT3 and ZnT10. These transporters work to reduce cytosolic zinc, suggesting that increased cytosolic zinc mediates Nox1 upregulation. Other metals including copper, iron, cobalt and manganese failed to upregulate Nox1, suggesting that this pathway is zinc specific. Nox1 upregulation was inhibited by actinomycin D (ACD), an inhibitor of transcription, by inhibition of NF-κB, a known Nox1 transcriptional regulator and by N-acetyl cysteine (NAC) and MitoTEMPO, suggesting that NF-κB and mitochondrial ROS mediate zinc effects. Supporting this idea, we found that zinc increased NF-κB activation in the cytosol, stimulated the translocation of the p65 subunit to the nucleus, and that zinc accumulated in mitochondria increasing mitochondrial ROS, measured using MitoSox. Further, zinc-induced senescence was reduced by inhibition of NF-κB or reduction of mitochondrial ROS with MitoTEMPO. NF-κB activity was also reduced by MitoTEMPO, suggesting that mitochondrial ROS is upstream of NF-κB.Innovation and ConclusionOur data demonstrate that altered zinc distribution leading to accumulation of zinc in the mitochondria increases mitochondrial ROS production causing NF-κB activation which in turn upregulates Nox1 expression inducing senescence of VSMCs.

Graphical abstract

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