Metabolic flux analysis in adipose tissue reprogramming.

Obesity is a growing epidemic in the United States and worldwide and is associated with insulin resistance and cardiovascular disease, among other comorbidities. Understanding of the pathology that links overnutrition to these disease processes is ongoing. Adipose tissue is a heterogeneous organ comprised of multiple different cell types and it is likely that dysregulated metabolism within these cell populations disrupts both inter- and intracellular interactions and is a key driver of human disease. In recent years, metabolic flux analysis, which offers a precise quantification of metabolic pathway fluxes in biological systems, has emerged as a candidate strategy for uncovering the metabolic changes that stoke these disease processes. In this mini review, we discuss metabolic flux analysis as an experimental tool, with a specific emphasis on mass spectrometry with isotope tracing as this is the technique most frequently used for metabolic flux analysis in adipocytes. Furthermore, we examine existing literature that uses metabolic flux analysis to further our understanding of adipose tissue biology. Our group has a specific interest in understanding the role of white adipose tissue inflammation in the progression of cardiometabolic disease, as we know that in obesity the accumulation of pro-inflammatory adipose tissue macrophages is associated with significant morbidity, so we use this as a paradigm throughout our review for framing the application of these experimental techniques. However, there are many other biological applications to which they can be applied to further understanding of not only adipose tissue biology but also systemic homeostasis.

Active antennal movements in Drosophila can tune wind encoding.

Insects use their antennae to smell odors,1,2 detect auditory cues,3,4 and sense mechanosensory stimuli such as wind5 and objects,6,7,8 frequently by combining sensory processing with active movements. Genetic access to antennal motor systems would therefore provide a powerful tool for dissecting the circuit mechanisms underlying active sensing, but little is known about how the most genetically tractable insect, Drosophila melanogaster, moves its antennae. Here, we use deep learning to measure how tethered Drosophila move their antennae in the presence of sensory stimuli and identify genetic reagents for controlling antennal movement. We find that flies perform both slow adaptive movements and fast flicking movements in response to wind-induced deflections, but not the attractive odor apple cider vinegar. Next, we describe four muscles in the first antennal segment that control antennal movements and identify genetic driver lines that provide access to two groups of antennal motor neurons and an antennal muscle. Through optogenetic inactivation, we provide evidence that antennal motor neurons contribute to active movements with different time courses. Finally, we show that activation of antennal motor neurons and muscles can adjust the gain and acuity of wind direction encoding by antennal displacement. Together, our experiments provide insight into the neural control of antennal movement and suggest that active antennal positioning in Drosophila may tune the precision of wind encoding.

A neural circuit for wind-guided olfactory navigation.

To navigate towards a food source, animals frequently combine odor cues about source identity with wind direction cues about source location. Where and how these two cues are integrated to support navigation is unclear. Here we describe a pathway to the Drosophila fan-shaped body that encodes attractive odor and promotes upwind navigation. We show that neurons throughout this pathway encode odor, but not wind direction. Using connectomics, we identify fan-shaped body local neurons called h∆C that receive input from this odor pathway and a previously described wind pathway. We show that h∆C neurons exhibit odor-gated, wind direction-tuned activity, that sparse activation of h∆C neurons promotes navigation in a reproducible direction, and that h∆C activity is required for persistent upwind orientation during odor. Based on connectome data, we develop a computational model showing how h∆C activity can promote navigation towards a goal such as an upwind odor source. Our results suggest that odor and wind cues are processed by separate pathways and integrated within the fan-shaped body to support goal-directed navigation.

Reach and representativeness of ethnic minority women in the Health Is Power Study: a longitudinal analysis.

Reach is a key factor in translating research to practical application. This study examined reach and representativeness of a multi-city, randomized controlled community health trial in African American (AA) and Hispanic or Latina (HL) women. Participants completed measures of demographics, body mass index (BMI), percent body fat, resting heart rate, and blood pressure followed by a run-in procedure and a randomization meeting. AA were more likely to be screened out initially; HL were more likely to drop out. Participation did not differ by city or recruitment method. Women who completed the post-intervention assessment were more likely to be AA, older, and have higher socioeconomic status (p values < .05). This study showed moderate levels of reach but overrepresented higher educated, wealthier, and older women at the completion of the study. Representativeness can change over the course of the study and impact the practicality of translating research to practice.

Concordance and correlates of direct and indirect built environment measurement among minority women.

PURPOSE: To measure the concordance of directly and indirectly measured neighborhood attributes and to determine the correlates of the concordance between directly and indirectly measured built environment attributes. DESIGN: Environmental cross-sectional design. SETTING: Urban and suburban neighborhoods within Harris County, Houston, and Travis County, Austin, Texas. SUBJECTS: Community-dwelling African-American and Hispanic or Latina women. MEASURES: Physical activity resource accessibility, path maintenance, and pedestrian and bicycle facilities were measured directly and indirectly. Directly or objectively measured neighborhood attributes were measured by the Physical Activity Resource Assessment and Pedestrian Environmental Data Scan instruments. Indirectly measured or self-reported neighborhood attributes were measured by the International Physical Activity Prevalence Study environmental survey module. ANALYSIS: Logistic regression was used to measure the concordance between directly and indirectly measured neighborhood attributes with ethnicity as a covariate. Residual values were calculated to determine the strength and direction of concordance. RESULTS: Participants' (N  =  409) average body mass index (BMI) was classified as obese (MBMI  =  34.5 kg/m(2), SD  =  7.9), and the mean body fat percentage was 42.8% (SD  =  7.1). The correlates BMI, body fat percentage, physical activity, and ethnicity were not significantly associated with any built environment attribute or concordance value, and none of our models significantly predicted indirectly measured built environment attributes. CONCLUSION: Being less familiar with certain built environment attributes may not be associated with weight status or physical activity levels among African-American and Hispanic or Latina women.

Mediating effects of group cohesion on physical activity and diet in women of color: health is power.

PURPOSE: To determine the effects and mediating factors of a physical activity (PA) or vegetable and fruit (VF) group cohesion intervention. DESIGN: Longitudinal design. SETTING: Harris County and Travis County, Texas. PARTICIPANTS: Community-dwelling African-American and Hispanic or Latina women. INTERVENTION: Three hundred ten women were randomized to a PA (n  =  204) or VF (n  =  106) intervention group. Women met in groups six times over the course of 6 months and were exposed to a group cohesion intervention to promote walking or to increase VF consumption. MEASURES: Women completed the International PA Questionnaire, National Cancer Institute VF and fat screeners, PA Group Environment Questionnaire, and 7-day accelerometer protocol at baseline and post-intervention. ANALYSES: The direct and mediated effects of the intervention on outcomes were evaluated using a mediational chain model, controlling for baseline values and covariates using path analysis. RESULTS: Women were middle aged (mean  =  44.4 years) and overweight or obese (mean body mass index  =  34.0 kg/m(2)). PA increased and fat consumption decreased for both groups, whereas VF consumption increased for women in VF group only (all p < .05). Increased task cohesion led to hypothesized increases in psychosocial factors in the PA group but not to behavioral changes. CONCLUSIONS: Group cohesion interventions may have psychological and physical health benefits for African-American and Hispanic or Latina women, but refinement of measures and intervention delivery is needed to determine whether hypothesized mediational pathways are valid.

Neighborhood factors influence physical activity among African American and Hispanic or Latina women.

This study investigated the relationship between neighborhood street-scale elements, such as traffic lights and crossing aids, and physical activity (PA) adoption and maintenance in African American and Hispanic or Latina women. Women (N=309) participated in a 6-month intervention and completed baseline and post-intervention assessments of PA. Trained field assessors completed the Pedestrian Environment Data Scan in participants' neighborhoods. Adjusted linear regression models found attractiveness for bicycling significantly predicted post-intervention accelerometer-measured PA. Greater traffic control devices and crossing aids were associated with greater PA among women assigned to the PA intervention group, and greater street amenities were associated with greater PA among those in the comparison group. Neighborhood factors may interact favorably with behavioral interventions to promote PA adoption and maintenance, and should be considered in health promotion efforts.

The concordance of directly and indirectly measured built environment attributes and physical activity adoption.

BACKGROUND: Physical activity (PA) adoption is essential for obesity prevention and control, yet ethnic minority women report lower levels of PA and are at higher risk for obesity and its comorbidities compared to Caucasians. Epidemiological studies and ecologic models of health behavior suggest that built environmental factors are associated with health behaviors like PA, but few studies have examined the association between built environment attribute concordance and PA, and no known studies have examined attribute concordance and PA adoption. PURPOSE: The purpose of this study was to associate the degree of concordance between directly and indirectly measured built environment attributes with changes in PA over time among African American and Hispanic Latina women participating in a PA intervention. METHOD: Women (N = 410) completed measures of PA at Time 1 (T1) and Time 2 (T2); environmental data collected at T1 were used to compute concordance between directly and indirectly measured built environment attributes. The association between changes in PA and the degree of concordance between each directly and indirectly measured environmental attribute was assessed using repeated measures analyses. RESULTS: There were no significant associations between built environment attribute concordance values and change in self-reported or objectively measured PA. Self-reported PA significantly increased over time (F(1,184) = 7.82, p = .006), but this increase did not vary by ethnicity or any built environment attribute concordance variable. CONCLUSIONS: Built environment attribute concordance may not be associated with PA changes over time among minority women. In an effort to promote PA, investigators should clarify specific built environment attributes that are important for PA adoption and whether accurate perceptions of these attributes are necessary, particularly among the vulnerable population of minority women.

Health is Power: an ecological, theory-based health intervention for women of color.

OBJECTIVE: Physical inactivity and poor dietary habits plague Americans as health challenges, with women of color most vulnerable to their detrimental effects. Individually focused interventions have not demonstrated lasting success, possibly due to the lack of focus on sustainable social and physical environment factors. This manuscript describes the rationale, design and methodology of Health Is Power (HIP), a transcultural, community based, randomized controlled trial that investigated the effectiveness of a group cohesion intervention to increase physical activity and improve dietary habits in African American and Hispanic or Latina women in Houston and Austin, Texas. METHODS: The intervention development was guided by group dynamics principles anchored within an ecologic model. RESULTS: Women participated in three health assessments and a six month face to face intervention that included evidence-based behavioral methods - integrated into strategies to promote group cohesion - framed to account for environmental factors contributing to health disparities. Women participated in team building activities, environmental mapping exercises, and supervised walks or taste tests. CONCLUSIONS: Neighborhood contextual and environmental measures are described to test ecologic factors that may contribute to behavioral maintenance. Theoretically guided interventions that account for multiple levels of influence in behavior initiation and maintenance stand to improve health outcomes in vulnerable populations.

Multiple measures of physical activity, dietary habits and weight status in African American and Hispanic or Latina women.

Compared measures of physical activity and dietary habits used in the Health Is Power (HIP) study, and described the associations of physical activity and dietary habits among African American and Hispanic or Latino women, adjusted for weight status. Cross-sectional baseline data were compared for community dwelling, healthy African American (N = 262) and Hispanic or Latina women (N = 148) who participated in HIP. Physical activity was measured using the International Physical Activity Questionnaire (IPAQ) long form, the Check And Line Questionnaire (CALQ) log and accelerometry. Dietary habits were measured using NCI 24-h recall screeners, vegetable and fruit (VF) logs and the NCI Diet History Questionnaire (DHQ). Differences in physical activity and dietary habits were assessed using simultaneous 2 (ethnicity) × 3 (weight status) ANCOVAs adjusted for age and socioeconomic status. Women (M age = 44.4 ± 10.9 years) were obese (M = 34.0 ± 9.7 kg/m(2)), did not meet physical activity guidelines as measured by accelerometry (M = 19.4 ± 19.1 min MVPA/day) and ate few VF (M = 2.8 ± 2.7 servings/day). DHQ variables differed by weight status. IPAQ was associated with CALQ, and CALQ with accelerometry (P < .05). IPAQ was not associated with accelerometry. Regardless of ethnicity, normal weight women did more physical activity, reported more VF consumption, and consumed more fat calories than overweight and obese women (Ps < .05). African American women did more MVPA than Hispanic or Latino women (P < .001). Relationships between behaviors and weight status suggest accelerometry and DHQ are preferable, regardless of ethnicity; and studies may capture different domains of physical activity and dietary habits depending on measure used.

Neighborhood and PA: neighborhood factors and physical activity in African American public housing residents.

BACKGROUND: In the US, public housing developments are typically located in lower socioeconomic status neighborhoods that may have poorer quality street level conditions, placing residents in neighborhoods that are less supportive for physical activity (PA). This study investigated the relationship of detailed, objectively assessed street-level pedestrian features with self-reported and measured PA in African American public housing residents. METHODS: Every street segment (N = 2093) within an 800 m radius surrounding each housing development (N = 12) was systematically assessed using the Pedestrian Environment Data Scan (PEDS). Participants completed an interviewer administered International Physical Activity Questionnaire (IPAQ) Short Form and wore a pedometer for 1 week. RESULTS: Women reported significantly less vigorous (mean = 1955 vs. 2896 METs), moderate (mean = 733 vs. 1309 mets), walking (mean = 1080 vs. 1376 METs), and total (mean = 3768 vs. 5581 METs) PA on the IPAQ compared with men (all P <.05). Women took fewer pedometer steps per day (M = 3753 vs. 4589) compared with men, but this was not statistically significant. Regression analyses showed that for women, lower speed limits were associated with vigorous; higher street segment density was associated with more moderate PA; lower speed limits, fewer crossing aids, and more lanes were associated with more walking; and, fewer lanes was associated with more overall PA. For men, fewer sidewalk connections were associated with more moderate PA; lower speed limits were associated with more walking; and, lower speed limits was associated with more overall PA. CONCLUSIONS: Neighborhood factors influence physical activity; in particular, lower speed limits appear most commonly linked with increased physical activity in both men and women.

SALSA : SAving Lives Staying Active to Promote Physical Activity and Healthy Eating.

Physical inactivity, poor dietary habits, and obesity are vexing problems among minorities. SAving Lives, Staying Active (SALSA) was an 8-week randomized controlled crossover design, pilot study to promote regular physical activity (PA) and fruit and vegetable (FV) consumption as a means to preventing weight gain among women of color. Participants completed measures of demographics, PA, and dietary habits. Women (N = 50; M = 42 years) who participated were overweight (MBMI = 29.7 kg/m(2); Mbody fat = 38.5%) and reported low levels of leisure time PA (M = 10.7 MET-min/wk) and FV consumption (M = 4.2 servings/day). All were randomized to a four-week (1) semiweekly Latin dance group or (2) internet-based dietary education group. All participants reported a significant increase in weekly leisure time PA from baseline (M = 10.7 MET-min/wk) to follow up (M = 34.0 MET-min/wk, P < .001), and FV consumption increased over time by group (P = .02). Data suggest that Latin dance interventions to improve PA and web-based interventions to improve dietary habits show promise for improving health among women of color.

A picture of the healthful food environment in two diverse urban cities.

BACKGROUND: Local food environments influence fresh produce purchase and consumption, and previous research has found disparities in local food environments by income and ethnicity. Other existing studies have begun to quantify the distribution of food sources, but there has been limited attention to important features or types of healthful food that are available or their quality or cost. Two studies assessed the type, quantity, quality and cost of healthful food from two diverse urban cities, Kansas City, Kansas and Missouri and Honolulu, Hawaii, and evaluated differences by neighborhood income and ethnic composition. METHOD: A total of 343 food stores in urban neighborhoods were assessed using the one-page Understanding Neighborhood Determinants of Obesity (UNDO) Food Stores Assessment (FSA) measuring healthful foods. US Census data were used to define median household income and ethnic minority concentration. RESULTS: In Study 1, most low socioeconomic status (SES), high ethnic minority neighborhoods had primarily convenience, liquor or small grocery stores. Quality of produce was typically lower, and prices of some foods were more than in comparison neighborhoods. In Study 2, low SES neighborhoods had more convenience and grocery stores. Farmers' markets and supermarkets had the best produce availability and quality, and farmers' markets and pharmacies had the lowest prices. CONCLUSIONS: Messages emphasizing eating more fruits and vegetables are not realistic in urban, low SES, high ethnic concentration neighborhoods. Farmers' markets and supermarkets provided the best opportunities for fresh produce. Increasing access to farmers' markets and supermarkets or reducing prices could improve the local food environment.

Neighborhood sampling: how many streets must an auditor walk?

This study tested the representativeness of four street segment sampling protocols using the Pedestrian Environment Data Scan (PEDS) in eleven neighborhoods surrounding public housing developments in Houston, TX. The following four street segment sampling protocols were used (1) all segments, both residential and arterial, contained within the 400 meter radius buffer from the center point of the housing development (the core) were compared with all segments contained between the 400 meter radius buffer and the 800 meter radius buffer (the ring); all residential segments in the core were compared with (2) 75% (3) 50% and (4) 25% samples of randomly selected residential street segments in the core. Analyses were conducted on five key variables: sidewalk presence; ratings of attractiveness and safety for walking; connectivity; and number of traffic lanes. Some differences were found when comparing all street segments, both residential and arterial, in the core to the ring. Findings suggested that sampling 25% of residential street segments within the 400 m radius of a residence sufficiently represents the pedestrian built environment. Conclusions support more cost effective environmental data collection for physical activity research.