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Open Access Publications from the University of California

Recent Work

Tobacco use remains the single most preventable cause of disease, disability, and death in the United States and in California. The Tobacco-Related Disease Research Program (TRDRP) is one of three entities that constitute California’s program to control tobacco consumption and alleviate the burden of tobacco-related disease. This effort was initiated by Proposition 99, “The Tobacco Tax and Health Protection Act of 1988” which mandated that the Department of Health Services, the Department of Education and the University of California be allocated a portion of the tobacco tax revenue collected to address issues of tobacco consumption and its consequences in the state. Enabling legislation requested that the University of California, in its role as the research arm of the state, “administer a comprehensive grant program to support research efforts related to the prevention, causes, and treatment of tobacco-related diseases” and that “ all qualified investigators, regardless of institutional affiliation, shall have equal access and opportunity to compete for the funds.”

The TRDRP is administered by the University of California and is a program of the Research Grants Program Office (RGPO), Office of Research and Graduate Studies at the University of California, Office of the President.

Cover page of G protein-coupled receptors activate p38 MAPK via a non-canonical TAB1-TAB2- and TAB1-TAB3-dependent pathway in endothelial cells.

G protein-coupled receptors activate p38 MAPK via a non-canonical TAB1-TAB2- and TAB1-TAB3-dependent pathway in endothelial cells.

(2019)

Endothelial dysfunction is induced by inflammatory mediators including multiple G protein-coupled receptor (GPCR) agonists. However, the GPCR signaling pathways that promote endothelial dysfunction are incompletely understood. We previously showed that thrombin promotes endothelial barrier disruption through autophosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) via a non-canonical transforming growth factor-β-activated protein kinase-1-binding protein-1 (TAB1) and TAB2-dependent pathway rather than the canonical three-tiered kinase cascade. Here, we sought to determine whether other GPCR agonists stimulate p38 MAPK activation via this non-canonical pathway in human endothelial cells derived from different vascular beds. Using primary human umbilical vein endothelial cells (HUVECs), HUVEC-derived EA.hy926 cells, and human dermal microvascular endothelial cells (HDMECs), we found that both non-canonical and canonical p38 activation pathways components are expressed in these various endothelial cell types, including TAB3, a structurally-related TAB2 homolog. Moreover, multiple GPCRs agonists, including thrombin, histamine, prostaglandin E2, and ADP, stimulated robust p38 autophosphorylation, whereas phosphorylation of the upstream MAPKs MAP kinase kinase 3 (MKK3) and MKK6, was virtually undetectable, indicating that non-canonical p38 activation may exist for other GPCRs. Indeed, in EA.hy926 cells, thrombin- and histamine-stimulated p38 activation depended on TAB1-TAB2, whereas in primary HUVECs, both TAB1-TAB2 and TAB1-TAB3 were required for p38 activation. In HDMECs, thrombin-induced p38 activation depended on TAB1-TAB3, but histamine-induced p38 activation required TAB1-TAB2. Moreover, thrombin- and histamine-stimulated interleukin-6 production required both TAB1-TAB2 and TAB1-TAB3 in HUVEC. We conclude that multiple GPCR agonists utilize non-canonical TAB1-TAB2 and TAB1-TAB3-dependent p38 activation to promote endothelial inflammatory responses.

Cover page of Vascular endothelial function is impaired by aerosol from a single IQOS HeatStick to the same extent as by cigarette smoke.

Vascular endothelial function is impaired by aerosol from a single IQOS HeatStick to the same extent as by cigarette smoke.

(2018)

BACKGROUND:Heated tobacco products (also called 'heat-not-burn' products) heat tobacco at temperatures below that of combustion, causing nicotine and other compounds to aerosolise. One such product, IQOS from Philip Morris International, is being marketed internationally with claims of harm reduction. We sought to determine whether exposure to IQOS aerosol impairs arterial flow-mediated dilation (FMD), a measure of vascular endothelial function that is impaired by tobacco smoke. METHODS:We exposed anaesthetised rats (n=8/group) via nose cone to IQOS aerosol from single HeatSticks, mainstream smoke from single Marlboro Red cigarettes or clean air for a series of consecutive 30 s cycles over 1.5-5 min. Each cycle consisted of 15 or 5 s of exposure followed by removal from the nose cone. We measured pre-exposure and postexposure FMD, and postexposure serum nicotine and cotinine. RESULTS:FMD was impaired comparably by ten 15 s exposures and ten 5 s exposures to IQOS aerosol and to cigarette smoke, but not by clean air. Serum nicotine levels were similar to plasma levels after humans have smoked one cigarette, confirming that exposure conditions had real-world relevance. Postexposure nicotine levels were ~4.5-fold higher in rats exposed to IQOS than to cigarettes, despite nicotine being measured in the IQOS aerosol at ~63% the amount measured in smoke. When IQOS exposure was briefer, leading to comparable serum nicotine levels to the cigarette group, FMD was still comparably impaired. CONCLUSIONS:Acute exposures to IQOS aerosol impairs FMD in rats. IQOS use does not necessarily avoid the adverse cardiovascular effects of smoking cigarettes.

Cover page of Integrin αvβ8-expressing tumor cells evade host immunity by regulating TGF-β activation in immune cells.

Integrin αvβ8-expressing tumor cells evade host immunity by regulating TGF-β activation in immune cells.

(2018)

TGF-β is a promising immunotherapeutic target. It is expressed ubiquitously in a latent form that must be activated to function. Determination of where and how latent TGF-β (L-TGF-β) is activated in the tumor microenvironment could facilitate cell- and mechanism-specific approaches to immunotherapeutically target TGF-β. Binding of L-TGF-β to integrin αvβ8 results in activation of TGF-β. We engineered and used αvβ8 antibodies optimized for blocking or detection, which - respectively - inhibit tumor growth in syngeneic tumor models or sensitively and specifically detect β8 in human tumors. Inhibition of αvβ8 potentiates cytotoxic T cell responses and recruitment of immune cells to tumor centers - effects that are independent of PD-1/PD-L1. β8 is expressed on the cell surface at high levels by tumor cells, not immune cells, while the reverse is true of L-TGF-β, suggesting that tumor cell αvβ8 serves as a platform for activating cell-surface L-TGF-β presented by immune cells. Transcriptome analysis of tumor-associated lymphoid cells reveals macrophages as a key cell type responsive to β8 inhibition with major increases in chemokine and tumor-eliminating genes. High β8 expression in tumor cells is seen in 20%-80% of various cancers, which rarely coincides with high PD-L1 expression. These data suggest tumor cell αvβ8 is a PD-1/PD-L1-independent immunotherapeutic target.

Cover page of Tobacco control in California compared with the rest of the USA: Trends in adult per capita cigarette consumption

Tobacco control in California compared with the rest of the USA: Trends in adult per capita cigarette consumption

(2018)

© Article author(s) 2018. Background In the 1990s, California led the USA in state-level tobacco control strategies. However, after 2000, California lost ground on cigarette taxes, although it maintained higher levels of smoke-free homes among smokers. Methods Trends in per capita cigarette consumption were assessed through taxed sales data and from self-report in repeated national cross-sectional surveys. Linear regressions identified changes in trends after year 2000 separately for California and the rest of the USA. Using data from each state, a linear regression tested the association between different tobacco control strategies and per capita consumption. Change in self-reported per capita consumption was partitioned into contributions associated with initiation, quitting and reduction in cigarette consumption level. Results Both taxed cigarette sales and per capita consumption declined rapidly in the USA from 1985 to 2015. Declines were particularly fast in California before 2000 but slowed thereafter. In 2014, per capita consumption in California was 29.4 packs/adult/year, but 90% higher in the rest of the USA. Modelling state-level data, every $1 increase in cigarette taxes reduced consumption by 4.8 (95% CI 2.9 to 6.8) packs/adult/year. Every 5% increase in the proportion of smokers with smoke-free homes reduced consumption by 8.0 (95% CI 7.0 to 8.9) packs/adult/year. The different patterns in California and the rest of the USA are at least partially explained by these two variables. The slow down in per capita consumption in California can be attributed to changes in initiation, quitting and especially smokers reducing their consumption level. Conclusions Tobacco control strategies need to be continually updated to maintain momentum towards a smoke-free society.

Cover page of A randomized controlled evaluation of the tobacco status project, a Facebook intervention for young adults

A randomized controlled evaluation of the tobacco status project, a Facebook intervention for young adults

(2018)

© 2018 Society for the Study of Addiction Aims: To test the efficacy of the Tobacco Status Project (TSP) Facebook smoking cessation intervention for young adults relative to referral to an on-line program on biochemically verified 7-day abstinence from smoking. Design: Two-group parallel randomized controlled trial, comparing TSP (n = 251) to on-line control (n = 249) with follow-up to 12 months. Setting: On-line, throughout the United States. Participants: Young adult cigarette smokers (mean age 21 years; 73% white, 55% female, 87% daily smokers). Interventions and comparator: TSP provided private Facebook groups tailored to stage of change to quit smoking, daily contacts, weekly live counseling sessions, and for those ready to quit, six cognitive behavioral therapy counseling sessions. Some TSP groups were assigned randomly to receive a monetary incentive for engagement. Control provided referral to the National Cancer Institute Smokefree.gov website. Measurements: primary outcome: Biochemically verified 7-day abstinence over 12 months. Secondary outcomes: Post-treatment (3-month) abstinence; reported abstinence, quit attempt, reduction in smoking, readiness to quit smoking over 12 months. Findings: Verified 7-day abstinence was not significantly different for intervention compared with control over 1 year: month 3 (8.3 versus 3.2%), 6 (6.2 versus 6.0%), and 12 (5.9 versus 10.0%); odds ratio (OR) = 1.07; 95% confidence interval (CI) = 0.23, 4.97; retention = 71%. There was an effect at 3 months (OR = 2.52; CI = 1.56, 4.04; P < 0.0001). There were no 12-month treatment effects for reported abstinence (P = 0.746), reduction in smoking by 50% or more (P = 0.533), likelihood of having made a quit attempt (P = 0.387) or stage of change over time (0.968). Participants in TSP engaged more and rated the intervention more favorably than those in the control condition. Conclusions: Compared with referral to a smoking cessation website, a novel USA-focused Facebook smoking cessation intervention did not improve abstinence from smoking over 1 year, but increased abstinence at the end of treatment and was engaging to participants.

Cover page of The Healing and Empowering Alaskan Lives Toward Healthy-Hearts (HEALTHH) Project: Study protocol for a randomized controlled trial of an intervention for tobacco use and other cardiovascular risk behaviors for Alaska Native People

The Healing and Empowering Alaskan Lives Toward Healthy-Hearts (HEALTHH) Project: Study protocol for a randomized controlled trial of an intervention for tobacco use and other cardiovascular risk behaviors for Alaska Native People

(2018)

© 2018 Elsevier Inc. Background: Tobacco use and tobacco-related diseases disproportionately affect Alaska Native (AN) people. Using telemedicine, this study aims to identify culturally-tailored, theoretically-driven, efficacious interventions for tobacco use and other cardiovascular disease (CVD) risk behaviors among AN people in remote areas. Design: Randomized clinical trial with two intervention arms: 1) tobacco and physical activity; 2) medication adherence and a heart-healthy AN diet. Participants: Participants are N = 300 AN men and women current smokers with high blood pressure or high cholesterol. Interventions: All participants receive motivational, stage-tailored, telemedicine-delivered counseling sessions at baseline and 3, 6, and 12 months follow-up; an individualized behavior change plan that is updated at each contact; and a behavior change manual. In Group 1, the focus is on tobacco and physical activity; a pedometer is provided and nicotine replacement therapy is offered. In Group 2, the focus is on medication adherence for treating hypertension and/or hypercholesterolemia; a medication bag and traditional food guide are provided. Measurements: With assessments at baseline, 3, 6, 12, and 18 months, the primary outcome is smoking status, assessed as 7-day point prevalence abstinence, biochemically verified with urine anabasine. Secondary outcomes include physical activity, blood pressure and cholesterol, medication compliance, diet, multiple risk behavior change indices, and cost-effectiveness. Comments: The current study has the potential to identify novel, feasible, acceptable, and efficacious interventions for treating the co-occurrence of CVD risk factors in AN people. Findings may inform personalized treatment and the development of effective and cost-effective intervention strategies for use in remote indigenous communities more broadly. Clinical Trial Registration # NCT02137902

Cover page of Technical Note: FreeCT_ICD: An open-source implementation of a model-based iterative reconstruction method using coordinate descent optimization for CT imaging investigations

Technical Note: FreeCT_ICD: An open-source implementation of a model-based iterative reconstruction method using coordinate descent optimization for CT imaging investigations

(2018)

To facilitate investigations into the impacts of acquisition and reconstruction parameters on quantitative imaging, radiomics and CAD using CT imaging, we previously released an open-source implementation of a conventional weighted filtered backprojection reconstruction called FreeCT_wFBP. Our purpose was to extend that work by providing an open-source implementation of a model-based iterative reconstruction method using coordinate descent optimization, called FreeCT_ICD.Model-based iterative reconstruction offers the potential for substantial radiation dose reduction, but can impose substantial computational processing and storage requirements. FreeCT_ICD is an open-source implementation of a model-based iterative reconstruction method that provides a reasonable tradeoff between these requirements. This was accomplished by adapting a previously proposed method that allows the system matrix to be stored with a reasonable memory requirement. The method amounts to describing the attenuation coefficient using rotating slices that follow the helical geometry. In the initially proposed version, the rotating slices are themselves described using blobs. We have replaced this description by a unique model that relies on trilinear interpolation together with the principles of Joseph's method. This model offers an improvement in memory requirement while still allowing highly accurate reconstruction for conventional CT geometries. The system matrix is stored column-wise and combined with an iterative coordinate descent (ICD) optimization. The result is FreeCT_ICD, which is a reconstruction program developed on the Linux platform using C++ libraries and released under the open-source GNU GPL v2.0 license. The software is capable of reconstructing raw projection data of helical CT scans. In this work, the software has been described and evaluated by reconstructing datasets exported from a clinical scanner which consisted of an ACR accreditation phantom dataset and a clinical pediatric thoracic scan.For the ACR phantom, image quality was comparable to clinical reconstructions as well as reconstructions using open-source FreeCT_wFBP software. The pediatric thoracic scan also yielded acceptable results. In addition, we did not observe any deleterious impact in image quality associated with the utilization of rotating slices. These evaluations also demonstrated reasonable tradeoffs in storage requirements and computational demands.FreeCT_ICD is an open-source implementation of a model-based iterative reconstruction method that extends the capabilities of previously released open-source reconstruction software and provides the ability to perform vendor-independent reconstructions of clinically acquired raw projection data. This implementation represents a reasonable tradeoff between storage and computational requirements and has demonstrated acceptable image quality in both simulated and clinical image datasets.