VitroJet: new features and case studies.

Single-particle cryo-electron microscopy has become a widely adopted method in structural biology due to many recent technological advances in microscopes, detectors and image processing. Before being able to inspect a biological sample in an electron microscope, it needs to be deposited in a thin layer on a grid and rapidly frozen. The VitroJet was designed with this aim, as well as avoiding the delicate manual handling and transfer steps that occur during the conventional grid-preparation process. Since its creation, numerous technical developments have resulted in a device that is now widely utilized in multiple laboratories worldwide. It features plasma treatment, low-volume sample deposition through pin printing, optical ice-thickness measurement and cryofixation of pre-clipped Autogrids through jet vitrification. This paper presents recent technical improvements to the VitroJet and the benefits that it brings to the cryo-EM workflow. A wide variety of applications are shown: membrane proteins, nucleosomes, fatty-acid synthase, Tobacco mosaic virus, lipid nanoparticles, tick-borne encephalitis viruses and bacteriophages. These case studies illustrate the advancement of the VitroJet into an instrument that enables accurate control and reproducibility, demonstrating its suitability for time-efficient cryo-EM structure determination.

Reducing risk for chronic disease: evaluation of a collective community approach to sustainable evidence-based health programming.

BACKGROUND: Community initiatives can shape health behaviors, such as physical activity and dietary habits, across a population and help reduce the risk of developing chronic disease. To achieve this goal and impact health outcomes, Pasadena Vibrant Community aimed to engage communities in an ongoing dialogue about the importance of healthy behaviors, implement and advance community-based strategies to promote health, and improve diet and physical activity behaviors. The initiative was centered around a collaboration between a backbone organization, steering committee, and 7 collaborating organizations funded to implement multicomponent, evidence-based programs.. The common agenda was detailed in a community action plan, which included 19 interventions targeting healthy eating and active living among adults and youth in Pasadena, Texas. METHODS: A mixed methods evaluation of the initiative was conducted over 4 years. Data sources included document reviews of quarterly progress reports (n = 86) and supplemental data reports (n = 16) provided by collaborating organizations, annual Steering Committee surveys (n = 4), and interviews conducted with staff from a subset of Collaborating Organizations (n = 4). RESULTS: The initiative reached over 50,000 community members per year through 19 evidence-based interventions and impacted health outcomes, including knowledge and adoption of healthy eating practices and increased physical activity. Thirty-one systems-level changes were implemented during the initiative, including 16 environmental changes. Steering Committee meetings and shared goals enabled connections, communication, and cooperation, which allowed Collaborating Organizations to address challenges and combine resources to deliver their programs. CONCLUSIONS: Community initiatives can effectively permeate the community by reaching individuals, improving physical activity and dietary habits, and ensuring sustainability. Based on the experience reported here, the success of a community initiative can be facilitated if collaborating organizations come together to implement evidence-based interventions and tailor them to the community, and if they are empowered by significant leadership and supportive collaboration and aligned by a common agenda.

Be Well Communities™: mobilizing communities to promote wellness and stop cancer before it starts.

PURPOSE: Increasingly, cancer centers are delivering population-based approaches to narrow the gap between known cancer prevention strategies and their effective implementation. Leveraging successful healthy community initiatives, MD Anderson developed Be Well Communities™, a model that implements evidence-based actions to directly impact people's lives. METHODS: In partnership with local organizations, MD Anderson's Be Well Communities team executed and evaluated 16 evidence-based interventions to address community priorities in healthy diets, physical activity, and sun safety. Evaluation included assessing the effectiveness of evidence-based interventions, stakeholders' perceptions of collaboration, and the population-level impact on dietary and physical activity behaviors among students using the School Physical Activity and Nutrition Survey and the System for Observing Fitness Instruction Time. Two-tailed t-tests were used to compare tested parameters at baseline and follow-up. p values less than .05 were considered significant. RESULTS: This model achieved its early outcomes, including effectively implementing evidence-based interventions, building strong partnerships, increasing access to healthy foods, improving the built environment, and increasing healthy food and water consumption and moderate to vigorous physical activity among students (p < .001). CONCLUSIONS: Be Well Communities is an effective model for positively impacting community health which could be leveraged by others to deliver evidence-based actions to improve population health.

Structure-Based Design of Potent and Orally Active Isoindolinone Inhibitors of MDM2-p53 Protein-Protein Interaction.

Inhibition of murine double minute 2 (MDM2)-p53 protein-protein interaction with small molecules has been shown to reactivate p53 and inhibit tumor growth. Here, we describe rational, structure-guided, design of novel isoindolinone-based MDM2 inhibitors. MDM2 X-ray crystallography, quantum mechanics ligand-based design, and metabolite identification all contributed toward the discovery of potent in vitro and in vivo inhibitors of the MDM2-p53 interaction with representative compounds inducing cytostasis in an SJSA-1 osteosarcoma xenograft model following once-daily oral administration.

Fragment-based drug discovery using cryo-EM.

Recent advances in electron cryo-microscopy (cryo-EM) structure determination have pushed the resolutions obtainable by the method into the range widely considered to be of utility for drug discovery. Here, we review the use of cryo-EM in fragment-based drug discovery (FBDD) based on in-house method development. We demonstrate not only that cryo-EM can reveal details of the molecular interactions between fragments and a protein, but also that the current reproducibility, quality, and throughput are compatible with FBDD. We exemplify this using the test system ß-galactosidase (Bgal) and the oncology target pyruvate kinase 2 (PKM2).

A Fragment-Derived Clinical Candidate for Antagonism of X-Linked and Cellular Inhibitor of Apoptosis Proteins: 1-(6-[(4-Fluorophenyl)methyl]-5-(hydroxymethyl)-3,3-dimethyl-1 H,2 H,3 H-pyrrolo[3,2- b]pyridin-1-yl)-2-[(2 R,5 R)-5-methyl-2-([(3R)-3-methylmorpholin-4-yl]methyl)piperazin-1-yl]ethan-1-one (ASTX660).

Inhibitor of apoptosis proteins (IAPs) are promising anticancer targets, given their roles in the evasion of apoptosis. Several peptidomimetic IAP antagonists, with inherent selectivity for cellular IAP (cIAP) over X-linked IAP (XIAP), have been tested in the clinic. A fragment screening approach followed by structure-based optimization has previously been reported that resulted in a low-nanomolar cIAP1 and XIAP antagonist lead molecule with a more balanced cIAP-XIAP profile. We now report the further structure-guided optimization of the lead, with a view to improving the metabolic stability and cardiac safety profile, to give the nonpeptidomimetic antagonist clinical candidate 27 (ASTX660), currently being tested in a phase 1/2 clinical trial (NCT02503423).

ASTX660, a Novel Non-peptidomimetic Antagonist of cIAP1/2 and XIAP, Potently Induces TNFα-Dependent Apoptosis in Cancer Cell Lines and Inhibits Tumor Growth.

Because of their roles in the evasion of apoptosis, inhibitor of apoptosis proteins (IAP) are considered attractive targets for anticancer therapy. Antagonists of these proteins have the potential to switch prosurvival signaling pathways in cancer cells toward cell death. Various SMAC-peptidomimetics with inherent cIAP selectivity have been tested clinically and demonstrated minimal single-agent efficacy. ASTX660 is a potent, non-peptidomimetic antagonist of cIAP1/2 and XIAP, discovered using fragment-based drug design. The antagonism of XIAP and cIAP1 by ASTX660 was demonstrated on purified proteins, cells, and in vivo in xenograft models. The compound binds to the isolated BIR3 domains of both XIAP and cIAP1 with nanomolar potencies. In cells and xenograft tissue, direct antagonism of XIAP was demonstrated by measuring its displacement from caspase-9 or SMAC. Compound-induced proteasomal degradation of cIAP1 and 2, resulting in downstream effects of NIK stabilization and activation of noncanonical NF-κB signaling, demonstrated cIAP1/2 antagonism. Treatment with ASTX660 led to TNFα-dependent induction of apoptosis in various cancer cell lines in vitro, whereas dosing in mice bearing breast and melanoma tumor xenografts inhibited tumor growth. ASTX660 is currently being tested in a phase I-II clinical trial (NCT02503423), and we propose that its antagonism of cIAP1/2 and XIAP may offer improved efficacy over first-generation antagonists that are more cIAP1/2 selective. Mol Cancer Ther; 17(7); 1381-91. ©2018 AACR.

Discovery of a Potent Nonpeptidomimetic, Small-Molecule Antagonist of Cellular Inhibitor of Apoptosis Protein 1 (cIAP1) and X-Linked Inhibitor of Apoptosis Protein (XIAP).

XIAP and cIAP1 are members of the inhibitor of apoptosis protein (IAP) family and are key regulators of anti-apoptotic and pro-survival signaling pathways. Overexpression of IAPs occurs in various cancers and has been associated with tumor progression and resistance to treatment. Structure-based drug design (SBDD) guided by structural information from X-ray crystallography, computational studies, and NMR solution conformational analysis was successfully applied to a fragment-derived lead resulting in AT-IAP, a potent, orally bioavailable, dual antagonist of XIAP and cIAP1 and a structurally novel chemical probe for IAP biology.

Public and Opinion Leader Willingness to Fund Obesity-Focused Policies in Kansas.

Obesity increases the risk for leading causes of death, including cardiovascular disease and some cancers. Midwestern and southern states have the highest obesity rates-in Kansas, one in every three adults is obese. We compared the willingness of Kansas adults and opinion leaders to pay more in taxes to fund obesity prevention policies. In 2014, we asked a representative sample of 2,203 Kansas adults (response rate 15.7%) and 912 opinion leaders (response rate 55%) drawn from elected office and other sectors, including business and health, whether they would pay an additional $50 in annual taxes to support five policies that improve access to healthy foods and opportunities for physical activity. We used adjusted Wald tests to compare public and opinion leaders' responses, and regression analysis to assess whether differences in respondents' gender, age, location (urban/rural), race/ethnicity, and political stance affected results. Adjusting for demographic differences, Kansas adults were more willing than opinion leaders to pay $50 in taxes for each of the five policy interventions. This study demonstrates a willingness among residents of a fiscally conservative state to pay increased taxes for policies that could reduce population obesity rates. Health professionals, including nurses, can use these findings to educate policy makers in Kansas and geopolitically similar states about widespread public support for obesity prevention policies. Public health and other nurses could also apply our methods to assess support for obesity prevention policies in their jurisdictions.

Adding a Social Marketing Campaign to a School-Based Nutrition Education Program Improves Children's Dietary Intake: A Quasi-Experimental Study.

BACKGROUND: Evidence supports the use of social marketing campaigns to improve nutrition knowledge and reinforce the effects of nutrition education programs. However, the additional effects of parent-focused social marketing with nutrition education have received little attention. OBJECTIVE: Our aim was to assess the impact of the Iowa Nutrition Network's school-based nutrition education program (Building and Strengthening Iowa Community Support for Nutrition and Physical Activity [BASICS]) and the benefits of adding a multichannel social marketing intervention (BASICS Plus) to increase parent-directed communication. DESIGN AND INTERVENTION: A quasi-experimental design with three study conditions compared a school-based nutrition education program (BASICS) with a school-based and social marketing intervention (BASICS Plus) and a no-treatment comparison group. PARTICIPANTS/SETTING: The study included 1,037 third-grade students attending 33 elementary schools and their parents. MAIN OUTCOME MEASURES: Measures included parents' reports of their children's in-home consumption of fruits and vegetables (F/V) and use of low-fat/fat-free milk. Data on F/V were collected using a modified version of the University of California Cooperative Extension Food Behavior Checklist; and data on milk use were collected using two questions from the National Health and Nutrition Examination Survey. STATISTICAL ANALYSES: Multilevel, mixed-effect regression models that account for correlation within repeated measures and children within school were used to compare the mean change over time in the outcome variable for one study group with the mean change over time for another study group. RESULTS: Children in BASICS increased mean consumption of fruit by 0.16 cups (P=0.04) compared with children in the comparison group. Children in BASICS Plus increased mean consumption of fruit by 0.17 cups (P=0.03) and mean consumption of vegetables by 0.13 cups (P=0.02). Children in BASICS Plus were 1.3 times (P=0.05) more likely to use low-fat/fat-free milk than children in either the BASICS group or the comparison group. CONCLUSIONS: Gaining parents' attention and engaging them in healthy eating practices for their children can be a useful way to increase the effectiveness of school-based nutrition education programs. This study demonstrates the benefits of incorporating a parent-focused social marketing campaign in nutrition education interventions.

Fragment-Based Drug Discovery Targeting Inhibitor of Apoptosis Proteins: Discovery of a Non-Alanine Lead Series with Dual Activity Against cIAP1 and XIAP.

Inhibitor of apoptosis proteins (IAPs) are important regulators of apoptosis and pro-survival signaling pathways whose deregulation is often associated with tumor genesis and tumor growth. IAPs have been proposed as targets for anticancer therapy, and a number of peptidomimetic IAP antagonists have entered clinical trials. Using our fragment-based screening approach, we identified nonpeptidic fragments binding with millimolar affinities to both cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP). Structure-based hit optimization together with an analysis of protein-ligand electrostatic potential complementarity allowed us to significantly increase binding affinity of the starting hits. Subsequent optimization gave a potent nonalanine IAP antagonist structurally distinct from all IAP antagonists previously reported. The lead compound had activity in cell-based assays and in a mouse xenograft efficacy model and represents a highly promising start point for further optimization.

Evaluating the Impact of Six Supplemental Nutrition Assistance Program Education Interventions on Children's At-Home Diets.

BACKGROUND: Nutrition education in the Supplemental Nutrition Assistance Program Education (SNAP-Ed) is designed to promote healthy eating behaviors in a low-income target population. PURPOSE: To evaluate the effectiveness of six SNAP-Ed interventions delivered in child care centers or elementary school settings in increasing participating children's at-home fruit and vegetable (F/V) consumption by 0.3 cups per day and use of fat-free or low-fat milk instead of whole or reduced-fat milk during the prior week. METHOD: Clustered randomized or quasi-experimental clustered trials took place in child care centers or elementary schools between 2010 and 2012. Parents of children at intervention and control sites completed baseline and follow-up surveys about their child's at home F/V consumption and other dietary behaviors. RESULTS: One of the six interventions was successful in meeting the objective of increasing children's F/V consumption by 0.3 cups per day. For three of the six interventions, there was a small but statistically significant increase in F/V consumption and/or use of low-fat or fat-free milk. CONCLUSION: Although not all interventions were effective, these findings suggest that it is possible for some SNAP-Ed interventions to improve dietary habits among low-income children among some families. The effective interventions appear to have benefited from implementation experience and sustained efforts at intervention refinement and improvement.

Structure of the BTB domain of Keap1 and its interaction with the triterpenoid antagonist CDDO.

The protein Keap1 is central to the regulation of the Nrf2-mediated cytoprotective response, and is increasingly recognized as an important target for therapeutic intervention in a range of diseases involving excessive oxidative stress and inflammation. The BTB domain of Keap1 plays key roles in sensing environmental electrophiles and in mediating interactions with the Cul3/Rbx1 E3 ubiquitin ligase system, and is believed to be the target for several small molecule covalent activators of the Nrf2 pathway. However, despite structural information being available for several BTB domains from related proteins, there have been no reported crystal structures of Keap1 BTB, and this has precluded a detailed understanding of its mechanism of action and interaction with antagonists. We report here the first structure of the BTB domain of Keap1, which is thought to contain the key cysteine residue responsible for interaction with electrophiles, as well as structures of the covalent complex with the antagonist CDDO/bardoxolone, and of the constitutively inactive C151W BTB mutant. In addition to providing the first structural confirmation of antagonist binding to Keap1 BTB, we also present biochemical evidence that adduction of Cys 151 by CDDO is capable of inhibiting the binding of Cul3 to Keap1, and discuss how this class of compound might exert Nrf2 activation through disruption of the BTB-Cul3 interface.

Nutrition-education program improves preschoolers' at-home diet: a group randomized trial.

OBJECTIVE: This study evaluated whether a nutrition-education program in child-care centers improved children's at-home daily consumption of fruits and vegetables, at-home use of low-fat/fat-free milk, and other at-home dietary behaviors. MATERIALS AND METHODS: Twenty-four child-care centers serving low-income families were matched by region, type, and size, and then randomly assigned to either an intervention or control condition. In the 12 intervention centers, registered dietitian nutritionists provided nutrition education to children and parents separately during a 6- to 10-week period. They also held two training sessions for center staff, to educate them on healthy eating and physical activity policies at the centers, and distributed weekly parent newsletters that included activities and recipes. Parents (n=1,143) completed a mail or telephone survey at baseline and follow-up to report information on their child's fruit, vegetable, and milk consumption and other dietary behaviors at home. This study used general and generalized linear mixed models to evaluate program impacts, while accounting for the clustering of children within centers. This study included child age, child sex, household size, respondent race/ethnicity, respondent age, and respondent sex as covariates. RESULTS: The program had a substantial impact on children's at-home daily consumption of vegetables and use of low-fat/fat-free milk. This study also found a significant increase in the frequency of child-initiated vegetable snacking, which might have contributed to the significant increase in vegetable consumption. The program did not have a significant impact on fruit consumption or parental offerings of fruits and vegetables, child-initiated fruit snacking, or child fruit consumption. CONCLUSIONS: This intervention in child-care settings that emphasized children, parents, and teachers significantly increased at-home vegetable and low-fat/fat-free milk consumption among low-income preschoolers.

A prospective analysis of the influence of older age on physician and patient decision-making when considering enrollment in breast cancer clinical trials (SWOG S0316).

PURPOSE: Patients older than 65 years are underrepresented in clinical trials. We conducted a prospective study (SWOG S0316) to determine physician- and patient-perceived barriers to breast cancer clinical trial enrollment for older patients. METHODS: Eight geographically diverse SWOG institutions participated. The study assessed patients' and physicians' decisions to enroll in or decline clinical treatment trials, including demographics, trial availability, and eligibility. Patient and physician questionnaires elicited concerns related to treatment, medical status, age, family, and financial or transportation concerns. RESULTS: A total of 1,079 patients were registered and eligible and 909 (84%) returned for follow-up. The major reason for nonaccrual was either trial unavailability or ineligibility (60%). Older patients were less likely to be eligible for trials (65% for age ≥65 years vs. 78% for age <65 years). If eligible, trial participation rates did not differ significantly by age (34% for age ≥65 years vs. 40% for age <65 years). Patients ≥65 years more often were concerned about side effects, had friends opposed to participation, or believed that participation would not benefit other generations. When trials were available and patients were eligible, physicians discussed trial participation with 76% of patients <65 years versus 58% of patients ≥65 years of age. For patients ≥65 years, 11% of physicians indicated age as a reason they did not enroll a patient in a clinical trial. CONCLUSION: Trial unavailability or patient ineligibility were the major reasons for lack of enrollment in breast cancer clinical trials for patients of all ages in this prospective study. Older patients were less likely to be eligible for trials, but if eligible they participated at similar rates to younger patients.

Cytochrome rC552, formed during expression of the truncated, Thermus thermophilus cytochrome c552 gene in the cytoplasm of Escherichia coli, reacts spontaneously to form protein-bound 2-formyl-4-vinyl (Spirographis) heme.

Expression of the truncated (lacking an N-terminal signal sequence) structural gene of Thermus thermophilus cytochrome c(552) in the cytoplasm of Escherichia coli yields both dimeric (rC(557)) and monomeric (rC(552)) cytochrome c-like proteins [Keightley, J. A., et al. (1998) J. Biol. Chem. 273, 12006-12016], which form spontaneously without the involvement of cytochrome c maturation factors. Cytochrome rC(557) is comprised of a dimer and has been structurally characterized [McRee, D., et al. (2001) J. Biol. Chem. 276, 6537-6544]. Unexpectedly, the monomeric rC(552) transforms spontaneously to a cytochrome-like chromophore having, in its reduced state, the Q(oo) transition (alpha-band) at 572 nm (therefore called p572). The X-ray crystallographic structure of rC(552), at 1.41 A resolution, shows that the 2-vinyl group of heme ring I is converted to a [heme-CO-CH(2)-S-CH(2)-C(alpha)] conjugate with cysteine 11. Electron density maps obtained from isomorphous crystals of p572 at 1.61 A resolution reveal that the 2-vinyl group has been oxidized to a formyl group. This explains the lower energy of the Q(oo)() transition, the presence of a new, high-frequency band in the resonance Raman spectra at 1666 cm(-1) for oxidized and at 1646 cm(-1) for reduced samples, and the greatly altered, paramagnetically shifted (1)H NMR spectrum observed for this species. The overall process defines a novel mechanism for oxidation of the 2-vinyl group to a 2-formyl group and adds to the surprising array of chemical reactions that occur in the interaction of heme with the CXXCH sequence motif in apocytochromes c.

Crystal structures of human cytochrome P450 3A4 bound to metyrapone and progesterone.

Cytochromes P450 (P450s) metabolize a wide range of endogenous compounds and xenobiotics, such as pollutants, environmental compounds, and drug molecules. The microsomal, membrane-associated, P450 isoforms CYP3A4, CYP2D6, CYP2C9, CYP2C19, CYP2E1, and CYP1A2 are responsible for the oxidative metabolism of more than 90% of marketed drugs. Cytochrome P450 3A4 (CYP3A4) metabolizes more drug molecules than all other isoforms combined. Here we report three crystal structures of CYP3A4: unliganded, bound to the inhibitor metyrapone, and bound to the substrate progesterone. The structures revealed a surprisingly small active site, with little conformational change associated with the binding of either compound. An unexpected peripheral binding site is identified, located above a phenylalanine cluster, which may be involved in the initial recognition of substrates or allosteric effectors.

Crystal structure of Pasteurella haemolytica ferric ion-binding protein A reveals a novel class of bacterial iron-binding proteins.

Pasteurellosis caused by the Gram-negative pathogen Pasteurella haemolytica is a serious disease leading to death in cattle. To scavenge growth-limiting iron from the host, the pathogen utilizes the periplasmic ferric ion-binding protein A (PhFbpA) as a component of an ATP-binding cassette transport pathway. We report the 1.2-A structure of the iron-free (apo) form of PhFbpA, which is a member of the transferrin structural superfamily. The protein structure adopts a closed conformation, allowing us to reliably assign putative iron-coordinating residues. Based on our analysis, PhFbpA utilizes a unique constellation of binding site residues and anions to octahedrally coordinate an iron atom. A surprising finding in the structure is the presence of two formate anions on opposite sides of the iron-binding pocket. The formate ions tether the N- and C-terminal domains of the protein and stabilize the closed structure, also providing clues as to probable candidates for synergistic anions in the iron-loaded state. PhFbpA represents a new class of bacterial iron-binding proteins.