Targeting Iron - Respiratory Reciprocity Promotes Bacterial Death.

Discovering new bacterial signaling pathways offers unique antibiotic strategies. Here, through an unbiased resistance screen of 3,884 gene knockout strains, we uncovered a previously unknown non-lytic bactericidal mechanism that sequentially couples three transporters and downstream transcription to lethally suppress respiration of the highly virulent P. aeruginosa strain PA14 - one of three species on the WHO's 'Priority 1: Critical' list. By targeting outer membrane YaiW, cationic lacritin peptide 'N-104' translocates into the periplasm where it ligates outer loops 4 and 2 of the inner membrane transporters FeoB and PotH, respectively, to suppress both ferrous iron and polyamine uptake. This broadly shuts down transcription of many biofilm-associated genes, including ferrous iron-dependent TauD and ExbB1. The mechanism is innate to the surface of the eye and is enhanced by synergistic coupling with thrombin peptide GKY20. This is the first example of an inhibitor of multiple bacterial transporters.

Chemoproteomic capture of RNA binding activity in living cells.

Proteomic methods for RNA interactome capture (RIC) rely principally on crosslinking native or labeled cellular RNA to enrich and investigate RNA-binding protein (RBP) composition and function in cells. The ability to measure RBP activity at individual binding sites by RIC, however, has been more challenging due to the heterogenous nature of peptide adducts derived from the RNA-protein crosslinked site. Here, we present an orthogonal strategy that utilizes clickable electrophilic purines to directly quantify protein-RNA interactions on proteins through photoaffinity competition with 4-thiouridine (4SU)-labeled RNA in cells. Our photo-activatable-competition and chemoproteomic enrichment (PACCE) method facilitated detection of >5500 cysteine sites across ~3000 proteins displaying RNA-sensitive alterations in probe binding. Importantly, PACCE enabled functional profiling of canonical RNA-binding domains as well as discovery of moonlighting RNA binding activity in the human proteome. Collectively, we present a chemoproteomic platform for global quantification of protein-RNA binding activity in living cells.

An Agenda for Advancing Research and Prevention at the Nexus of Work Organization, Occupational Stress, and Mental Health and Well-Being.

Work characteristics and worker well-being are inextricably connected. In particular, the characteristics of work organization shape and perpetuate occupational stress, which contributes to worker mental health and well-being outcomes. Consequently, the importance of understanding and addressing connections between work organization, occupational stress, and mental health and well-being-the focus of this Special Issue-increasingly demand attention from those affected by these issues. Thus, focusing on these issues in the long-haul truck driver (LHTD) sector as an illustrative example, the purpose of this commentary is as follows: (1) to outline current research approaches and the extant knowledge base regarding the connections between work organization, occupational stress, and mental health; (2) to provide an overview of current intervention strategies and public policy solutions associated with the current knowledge base to protect and promote worker mental health and well-being; and (3) to propose a two-pronged agenda for advancing research and prevention for workers during the 21st century. It is anticipated that this commentary, and this Special Issue more broadly, will both echo numerous other calls for building knowledge and engaging in this area and motivate further research within complementary current and novel research frameworks.

Predicting small molecule binding pockets on diacylglycerol kinases using chemoproteomics and AlphaFold.

Diacylglycerol kinases (DGKs) are metabolic kinases involved in regulating cellular levels of diacylglycerol and phosphatidic lipid messengers. The development of selective inhibitors for individual DGKs would benefit from discovery of protein pockets available for inhibitor binding in cellular environments. Here we utilized a sulfonyl-triazole probe (TH211) bearing a DGK fragment ligand for covalent binding to tyrosine and lysine sites on DGKs in cells that map to predicted small molecule binding pockets in AlphaFold structures. We apply this chemoproteomics-AlphaFold approach to evaluate probe binding of DGK chimera proteins engineered to exchange regulatory C1 domains between DGK subtypes (DGKα and DGKζ). Specifically, we discovered loss of TH211 binding to a predicted pocket in the catalytic domain when C1 domains on DGKα were exchanged that correlated with impaired biochemical activity as measured by a DAG phosphorylation assay. Collectively, we provide a family-wide assessment of accessible sites for covalent targeting that combined with AlphaFold revealed predicted small molecule binding pockets for guiding future inhibitor development of the DGK superfamily.

The Next Generation of Microbial Ecology and Its Importance in Environmental Sustainability.

Collectively, we have been reviewers for microbial ecology, genetics and genomics studies that include environmental DNA (eDNA), microbiome studies, and whole bacterial genome biology for Microbial Ecology and other journals for about three decades. Here, we wish to point out trends and point to areas of study that readers, especially those moving into the next generation of microbial ecology research, might learn and consider. In this communication, we are not saying the work currently being accomplished in microbial ecology and restoration biology is inadequate. What we are saying is that a significant milestone in microbial ecology has been reached, and approaches that may have been overlooked or were unable to be completed before should be reconsidered in moving forward into a new more ecological era where restoration of the ecological trajectory of systems has become critical. It is our hope that this introduction, along with the papers that make up this special issue, will address the sense of immediacy and focus needed to move into the next generation of microbial ecology study.

Rethinking Efforts to Improve Dietary Patterns Among Long-Haul Truck Drivers: Transforming Truck Stop Retail Food Environments Through Upstream Change.

A multitude of upstream occupational exposures influence poor dietary patterns that contribute to cardiometabolic health disparities among long-haul truck drivers in the United States. Herein, we delineate the unique characteristics of the truck driving profession that shape dietary patterns. Next, we discuss current health promotion efforts and why they are unlikely to be sufficient for improving population-level dietary patterns. We then advocate for prioritizing health promotion efforts that target upstream factors that influence population dietary patterns and have the potential to holistically and sustainably support drivers' nutrition. Finally, we propose novel research directions to catalyze upstream-oriented health promotion efforts.

Complex systems and participatory approaches to address maternal health disparities: Findings from a system dynamics group model building project in North Texas.

Focusing on non-Hispanic Black women (NHBW) in North Texas, this study employed participatory system dynamics modeling to explore three hypotheses: (1) stakeholders will conceptualize structural racism is a pervasive macrostructural force that exerts downstream impacts to shape and perpetuate maternal health disparities among NHBW; (2) stakeholders will identify key causal forces and leverage points that exist across levels of influence; and (3) stakeholders will identify complex interactions, in the form of circular causality, that are present among the key causal forces and leverage points that shape NHBW maternal health disparities. Nine participants engaged in a virtual system dynamics group model-building session that focused on eliciting key variables, behavior-over-time graphs (BOTGs), causal loop diagram (CLD), and targets for action. Participants identified 83 key variables. BOTGs included an average of 6.56 notations and time horizons that, on average, started in 1956. The CLD featured 11 reinforcing and seven balancing feedback loops. Eleven targets for action were identified. Structural racism was revealed as a pervasive macrostructural force that shaped maternal health outcomes among NHBW. Key causal forces and leverage points were identified across levels of influence. Finally, feedback loops within the CLD exhibited circular causality.

Metabolic syndrome among commercial truck drivers: The relationship between condition prevalence and crashes.

BACKGROUND: Metabolic syndrome (MetS) is especially prevalent among US truck drivers. However, there has been limited research exploring associations between MetS conditions with roadway crashes among truck drivers. The objective of this paper is to assess relationships between specific combinations of individual MetS components and crashes and near-misses. METHODS: Survey, biometric, and anthropometric data were collected from 817 truck drivers across 6 diverse US states. Survey data focused on demographics and roadway safety outcomes, and anthropometric/biometric data corresponded to five MetS conditions (waist circumference blood pressure, hemoglobin A1c, triglycerides, and high-density lipoprotein [HDL] cholesterol). Logistic regression was used to calculate odds ratios of lifetime crashes and near-miss 1-month period prevalence associated with: 1) specific MetS conditions regardless of presence or absence of other MetS conditions, and 2) specific MetS conditions and counts of other accompanying MetS conditions. RESULTS: Hypertension was the MetS characteristic most strongly associated with lifetime crash and 1-month near-miss outcomes, while high triglycerides, low HDL cholesterol, and large waist circumference were most commonly present among groups of conditions associated with crashes and near-misses. Overall, an increasing number of specific co-occurring MetS conditions were associated with higher reporting of roadway crashes. CONCLUSIONS: Specific combinations and higher prevalence of MetS conditions were associated with increased frequency of reported crashes. Moreover, when the co-occurrence of MetS conditions is aggregated, a dose-response relationship with crashes appears. These results suggest that policy changes and interventions addressing MetS may increase driver health and reduce crash risk.

Macrophage acetyl-CoA carboxylase regulates acute inflammation through control of glucose and lipid metabolism.

Acetyl-CoA carboxylase (ACC) regulates lipid synthesis; however, its role in inflammatory regulation in macrophages remains unclear. We generated mice that are deficient in both ACC isoforms in myeloid cells. ACC deficiency altered the lipidomic, transcriptomic, and bioenergetic profile of bone marrow-derived macrophages, resulting in a blunted response to proinflammatory stimulation. In response to lipopolysaccharide (LPS), ACC is required for the early metabolic switch to glycolysis and remodeling of the macrophage lipidome. ACC deficiency also resulted in impaired macrophage innate immune functions, including bacterial clearance. Myeloid-specific deletion or pharmacological inhibition of ACC in mice attenuated LPS-induced expression of proinflammatory cytokines interleukin-6 (IL-6) and IL-1ß, while pharmacological inhibition of ACC increased susceptibility to bacterial peritonitis in wild-type mice. Together, we identify a critical role for ACC in metabolic regulation of the innate immune response in macrophages, and thus a clinically relevant, unexpected consequence of pharmacological ACC inhibition.

Feeding desensitizes A1 adenosine receptors in adipose through FOXO1-mediated transcriptional regulation.

OBJECTIVE: Adipose tissue is a critical regulator of energy balance that must rapidly shift its metabolism between fasting and feeding to maintain homeostasis. Adenosine has been characterized as an important regulator of adipocyte metabolism primarily through its actions on A1 adenosine receptors (A1R). We sought to understand the role A1R plays specifically in adipocytes during fasting and feeding to regulate glucose and lipid metabolism. METHODS: We used Adora1 floxed mice with an inducible, adiponectin-Cre to generate FAdora1-/- mice, where F designates a fat-specific deletion of A1R. We used these FAdora1-/- mice along with specific agonists and antagonists of A1R to investigate changes in adenosine signaling within adipocytes between the fasted and fed state. RESULTS: We found that the adipose tissue response to adenosine is not static, but changes dynamically according to nutrient conditions through the insulin-Akt-FOXO1 axis. We show that under fasted conditions, FAdora1-/- mice had impairments in the suppression of lipolysis by insulin on normal chow and impaired glucose tolerance on high-fat diet. FAdora1-/- mice also exhibited a higher lipolytic response to isoproterenol than WT controls when fasted, however this difference was lost after a 4-hour refeeding period. We demonstrate that FOXO1 binds to the A1R promoter, and refeeding leads to a rapid downregulation of A1R transcript and desensitization of adipocytes to A1R agonism. Obesity also desensitizes adipocyte A1R, and this is accompanied by a disruption of cyclical changes in A1R transcription between fasting and refeeding. CONCLUSIONS: We propose that FOXO1 drives high A1R expression under fasted conditions to limit excess lipolysis during stress and augment insulin action upon feeding. Subsequent downregulation of A1R under fed conditions leads to desensitization of these receptors in adipose tissue. This regulation of A1R may facilitate reentrance into the catabolic state upon fasting.

Rural-urban, age, and gender disparities and trends in suicide and homicide: Multistate evidence across 12 years.

PURPOSE: Few studies have simultaneously assessed age and gender trends in homicide and suicide across the rural-urban continuum. Herein, we examine geographic and demographic trends in suicide and homicide death rates by: (1) determining overall macro and disaggregated trends; (2) examining differences in trends based on rural-urban county classification; and (3) identifying differences in stratified trends among age and gender classifications. METHODS: A retrospective study design used suicide and homicide data (n = 199,456) from years 2005to 2017 across 16 US states. Suicide and homicide deaths were grouped by age, gender, and rural-urban classification for descriptive analyses, and trends were analyzed using Joinpoint trend analysis software. FINDINGS: Violence resulted in 142,470 suicide and 56,986 homicide deaths between 2005 and 2017. Among both males and females, overall macro trends of suicide and homicide rates generally increased with greater rurality, and trends in rural rates differed from those in nonrural areas. Joinpoint trend analysis revealed significant increases in male suicide rates in large metropolitan (1.66%), micropolitan (1.78%), and rural areas (1.77%); female suicide rates in large metropolitan (2.17%), small metropolitan (3.25%), and micropolitan areas (3.26%); male homicide rates in large metropolitan areas (10.19%); and female homicide rates in rural areas (8.29%). Finally, when stratified by age, several significant trends were found, including increases in suicide rates among females aged 64 and older in rural areas (11.71%). CONCLUSIONS: Heterogeneous trends were found in suicide and homicide rates within specific rural-urban, age, and gender subgroups. Prevention efforts should proactively target those subgroups identified herein as most at-risk of violence.

Exploring the complexity of firearm homicides in Harris County, Texas, from 2009 to 2021: Implications for theory and prevention.

Firearm violence is a major health problem in the United States that clusters asymmetrically across geographic and demographic lines, and the persistence and unequal distribution of firearm violence suggests that novel causal explanations and theoretical frameworks may be warranted to guide preventive strategies. Thus, this study explores the following three hypotheses that are grounded in complex systems theory: 1) trends in firearm homicides risks have shifted heterogeneously in Harris County across endemic degree of risk; 2) firearm homicides clusters have remained resilient in Harris County across the study time period; and 3), the associations between known contextual correlates of firearm homicides and the distribution of firearm homicides risks in Harris County have manifested as nonlinear. Using a retrospective study design (n = 4,397) from January 1, 2009-June 31, 2021, medicolegal death investigation data from the Harris County Institute of Forensic Sciences and estimates of community characteristics from the American Community Survey were analyzed using Joinpoint trend analysis, kernel density geospatial analysis, and proportion tests. Trend analyses revealed that firearm homicides risks shifted heterogeneously across endemic degree of risk, with geographical areas with lower initial firearm homicides risks experiencing more profound upward shifts across the time period of the study. Geospatial analyses identified the resiliency of firearm homicides clusters across the study period, particularly in central, southern, and south-western districts of the city. Finally, the relationships between known contextual correlates and the distribution of firearm homicides risks in Harris County appeared to be nonlinear, particularly regarding ethnicity. This study provides data-driven results that suggest the plausibility of complex systems theory in advancing the understanding of causality in firearm homicides. Further, these findings support the urgent need for complex systems-informed preventive efforts that account for spatiotemporal heterogeneity, key interactions that generate nonlinearity, and latent feedback loops that underlie resiliency in firearm homicides.

Identification of ritanserin analogs that display DGK isoform specificity.

The diacylglycerol kinase (DGK) family of lipid enzymes catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid (PA). Both DAG and PA are lipid signaling molecules that are of notable importance in regulating cell processes such as proliferation, apoptosis, and migration. There are ten mammalian DGK enzymes that appear to have distinct biological functions. DGKα has emerged as a promising therapeutic target in numerous cancers including glioblastoma (GBM) and melanoma as treatment with small molecule DGKα inhibitors results in reduced tumor sizes and prolonged survival. Importantly, DGKα has also been identified as an immune checkpoint due to its promotion of T cell anergy, and its inhibition has been shown to improve T cell activation. There are few small molecule DGKα inhibitors currently available, and the application of existing compounds to clinical settings is hindered by species-dependent variability in potency, as well as concerns regarding isotype specificity particularly amongst other type I DGKs. In order to resolve these issues, we have screened a library of compounds structurally analogous to the DGKα inhibitor, ritanserin, in an effort to identify more potent and specific alternatives. We identified two compounds that more potently and selectively inhibit DGKα, one of which (JNJ-3790339) demonstrates similar cytotoxicity in GBM and melanoma cells as ritanserin. Consistent with its inhibitor profile towards DGKα, JNJ-3790339 also demonstrated improved activation of T cells compared with ritanserin. Together our data support efforts to identify DGK isoform-selective inhibitors as a mechanism to produce pharmacologically relevant cancer therapies.

Spatial social network research: a bibliometric analysis.

A restless and dynamic intellectual landscape has taken hold in the field of spatial social network studies, given the increasingly attention towards fine-scale human dynamics in this urbanizing and mobile world. The measuring parameters of such dramatic growth of the literature include scientific outputs, domain categories, major journals, countries, institutions, and frequently used keywords. The research in the field has been characterized by fast development of relevant scholarly articles and growing collaboration among and across institutions. The Journal of Economic Geography, Annals of the Association of American Geographers, and Urban Studies ranked first, second, and third, respectively, according to average citations. The United States, United Kingdom, and China were the countries that yielded the most published studies in the field. The number of international collaborative studies published in non-native English-speaking countries (such as France, Italy, and the Netherlands) were higher than native English-speaking countries. Wuhan University, the University of Oxford, and Harvard University were the universities that published the most in the field. "Twitter", "big data", "networks", "spatial analysis", and "social capital" have been the major keywords over the past 20 years. At the same time, the keywords such as "social media", "Twitter", "big data", "geography", "China", "human mobility", "machine learning", "GIS", "location-based social networks", "clustering", "data mining", and "location-based services" have attracted increasing attention in that same time frame, indicating the future research trends.