Acetylcholine-synthesizing macrophages in subcutaneous fat are regulated by ß2 -adrenergic signaling.

Non-neuronal cholinergic signaling, mediated by acetylcholine, plays important roles in physiological processes including inflammation and immunity. Our group first discovered evidence of non-neuronal cholinergic circuitry in adipose tissue, whereby immune cells secrete acetylcholine to activate beige adipocytes during adaptive thermogenesis. Here, we reveal that macrophages are the cellular protagonists responsible for secreting acetylcholine to regulate thermogenic activation in subcutaneous fat, and we term these cells cholinergic adipose macrophages (ChAMs). An adaptive increase in ChAM abundance is evident following acute cold exposure, and macrophage-specific deletion of choline acetyltransferase (ChAT), the enzyme for acetylcholine biosynthesis, impairs the cold-induced thermogenic capacity of mice. Further, using pharmacological and genetic approaches, we show that ChAMs are regulated via adrenergic signaling, specifically through the ß2 adrenergic receptor. These findings demonstrate that macrophages are an essential adipose tissue source of acetylcholine for the regulation of adaptive thermogenesis, and may be useful for therapeutic targeting in metabolic diseases.

Immune cell cholinergic signaling in adipose thermoregulation and immunometabolism.

Research focusing on adipose immunometabolism has been expanded from inflammation in white fat during obesity development to immune cell function regulating thermogenic fat, energy expenditure, and systemic metabolism. This opinion discusses our current understanding of how resident immune cells within the thermogenic fat niche may regulate whole-body energy homeostasis. Furthermore, various types of immune cells can synthesize acetylcholine (ACh) and regulate important physiological functions. We highlight a unique subset of cholinergic macrophages within subcutaneous adipose tissue, termed cholinergic adipose macrophages (ChAMs); these macrophages interact with beige adipocytes through cholinergic receptor nicotinic alpha 2 subunit (CHRNA2) signaling to induce adaptive thermogenesis. We posit that these newly identified thermoregulatory macrophages may broaden our view of immune system functions for maintaining metabolic homeostasis and potentially treating obesity and metabolic disorders.

Investigating the effects of suicide exposure among a clinical sample of active duty service members.

Suicide exposure warrants further investigation as a risk factor for suicide among military service members. This study aimed to examine associations among suicide exposure, suicidal ideation (SI), and psychological symptoms in a clinical sample of service members (N = 1,565, 64.4% suicide-exposed) and identify how one's relationship with the deceased impacts suicidality and psychological health in exposed individuals. A secondary analysis of cross-sectional survey data was conducted. Generalized linear regression analyses were used to identify associations between suicide exposure and both current SI and psychological symptoms among all participants; the associations between suicide exposure characteristics and psychological symptoms were only examined among exposed individuals. Exposure was not significantly associated with higher SI, ß = .007, SE = .16, p = .965, but was associated with PTSD, ß = 1.60, SE = 0.49, p = .001; anxiety, ß = .68, SE = .31, p = .031; and insomnia symptoms, ß = .98, SE = .25, p < .001. Among participants who had been exposed, high/long impact of exposure was positively associated with SI, ß = 0.94, SE = .26, p < .001, and psychological symptoms, PTSD: ß = 2.32, SE = .77, p = .002; anxiety: ß = 1.39, SE = .50, p = .005; insomnia: ß = .96, SE = .39, p = .015. Results illustrate the significant issue of suicide exposure within the military and show consideration of suicide exposure as a potential risk factor for adverse psychological outcomes is warranted.

Internalization of muscularity and thinness ideals: Associations with body dissatisfaction, eating disorder symptoms, and muscle dysmorphic symptoms in at risk sexual minority men.

OBJECTIVE: In the tripartite influence model, appearance-ideal internalization is identified as a prominent risk factor for the development of body dissatisfaction and subsequent eating disorder (ED) behaviors. For men, prior research has emphasized the importance of both thin-ideal internalization and muscular-ideal internalization in explaining later ED behaviors and muscle dysmorphia (MD) symptoms. Previous research in heterosexual men has shown that the associations between muscular-ideal internalization and ED or MD symptoms may depend on whether the individual has also internalized the thin ideal. However, this interaction has not been examined in research with sexual minority men (SMM). METHOD: The current study collected self-report data from 452 at risk SMM (i.e., endorsed body dissatisfaction), with ages ranging from 18 to 35 years. Linear regression models were conducted to test the interaction effects between thinness and muscularity internalization on ED symptoms, MD behaviors, and general body dissatisfaction. Simple slopes and the Johnson-Neyman technique were used to investigate significant interaction terms. RESULTS: Thin- and muscular-ideal internalization were positively associated with muscular appearance intolerance and dietary restriction with no significant interaction. Muscular drive for size was highest when both muscularity internalization and thinness internalization were high. Muscular-ideal internalization was positively associated with both cognitive restraint and general body dissatisfaction, but only at lower levels of thinness internalization. DISCUSSION: Given the interacting association between thinness and muscularity internalization and aspects of body dissatisfaction, attitudes, and behavior, prevention and intervention programs for EDs and MDs in SMM should seek to dismantle both thinness and muscularity internalization. PUBLIC SIGNIFICANCE STATEMENT: Internalizing-or adopting as one's own-the ideal of a body with low body fat and high muscularity has been shown to lead to muscle dysmorphia and eating disorder symptoms in men. The current study examines whether the combination of thin-ideal and muscular-ideal internalization is associated with worse symptoms than either facet alone in sexual minority men. Treatment efforts in sexual minority men should address both types of internalization.

Directing ricin-based immunotoxins with targeting affibodies and KDEL signal peptide to cancer cells effectively induces apoptosis and tumor suppression.

The plant toxin ricin, especially its cytotoxic A chain (RTA), can be genetically engineered with targeting ligands to develop specific anti-cancer recombinant immunotoxins (RITs). Here, we used affibody molecules targeting two cancer biomarkers, the receptors HER2 and EGFR, along with the KDEL signal peptide to construct two cancer-specific ricin-based RITs, HER2Afb-RTA-KDEL and EGFRAfb-RTA-KDEL. The affibodies successfully provided target-specificity and subsequent receptor-mediated endocytosis and the KDEL signal peptide routed the RITs through the retrograde transport pathway, effectively delivering RTA to the cytosol as well as avoiding the alternate recycling pathway that typical cancer cells frequently have. The in vivo efficacy of RITs was enhanced by introducing the albumin binding domain (AlBD) to construct AlBD/HER2Afb/RTA-KDEL. Systemic administration of AlBD-containing RITs to tumor-bearing mice significantly suppressed tumor growth without any noticeable side-effects. Collectively, combining target-selective affibody molecules, a cytotoxic RTA, and an intracellularly designating peptide, we successfully developed cancer-specific and efficacious ricin-based RITs. This approach can be applied to develop novel protein-based "magic bullets" to effectively suppress tumors that are resistant to conventional anti-cancer drugs.

A critical role for hepatic protein arginine methyltransferase 1 isoform 2 in glycemic control.

Appropriate control of hepatic gluconeogenesis is essential for the organismal survival upon prolonged fasting and maintaining systemic homeostasis under metabolic stress. Here, we show protein arginine methyltransferase 1 (PRMT1), a key enzyme that catalyzes the protein arginine methylation process, particularly the isoform encoded by Prmt1 variant 2 (PRMT1V2), is critical in regulating gluconeogenesis in the liver. Liver-specific deletion of Prmt1 reduced gluconeogenic capacity in cultured hepatocytes and in the liver. Prmt1v2 was expressed at a higher level compared to Prmt1v1 in hepatic tissue and cells. Gain-of-function of PRMT1V2 clearly activated the gluconeogenic program in hepatocytes via interactions with PGC1α, a key transcriptional coactivator regulating gluconeogenesis, enhancing its activity via arginine methylation, while no effects of PRMT1V1 were observed. Similar stimulatory effects of PRMT1V2 in controlling gluconeogenesis were observed in human HepG2 cells. PRMT1, specifically PRMT1V2, was stabilized in fasted liver and hepatocytes treated with glucagon, in a PGC1α-dependent manner. PRMT1, particularly Prmt1v2, was significantly induced in the liver of streptozocin-induced type 1 diabetes and high fat diet-induced type 2 diabetes mouse models and liver-specific Prmt1 deficiency drastically ameliorated diabetic hyperglycemia. These findings reveal that PRMT1 modulates gluconeogenesis and mediates glucose homeostasis under physiological and pathological conditions, suggesting that deeper understanding how PRMT1 contributes to the coordinated efforts in glycemic control may ultimately present novel therapeutic strategies that counteracts hyperglycemia in disease settings.

Structural stigma and sexual orientation-related reproductive health disparities in a longitudinal cohort study of female adolescents.

INTRODUCTION: Sexual minority female adolescents have worse reproductive health than heterosexual peers; research into the origins of these disparities is limited. Our objective was to examine whether exposure to structural stigma (e.g., societal-level conditions, cultural norms, institutional policies/practices that constrain the lives of the stigmatized) is associated with sexually transmitted infections (STIs) and teen pregnancy in sexual minority female adolescents. METHODS: Longitudinal data were utilized from 6581 female adolescents aged 9-14 years at baseline (1996) in the U.S.-based Growing Up Today Study and followed through 2007. We used a previously-validated structural stigma scale composed of four state-level items (e.g., employment non-discrimination policies) with one item added relevant to reproductive health. Risk ratios were generated from multivariate models. RESULTS: Sexual minority female adolescents were significantly more likely than heterosexual peers to have an STI diagnosis and teen pregnancy. Sexual minority female adolescents living in states with lower, compared to higher, levels of structural stigma were significantly less likely to have an STI diagnosis, after adjustment for individual- and state-level covariates (relative risk [RR] = 0.70, 95% confidence interval [CI]: 0.51, 0.97). In contrast, among completely heterosexual adolescents, structural stigma was not associated with STI diagnosis. Teen pregnancy risk-a rare outcome-did not vary by level of structural stigma for sexual minority or heterosexual adolescents. CONCLUSIONS: Structural stigma is a potential risk factor for adverse reproductive health among sexual minority female adolescents. Changing laws and policies to be inclusive of all people, regardless of sexual orientation, can help alleviate entrenched reproductive health disparities.

Formation and activation of thermogenic fat.

Thermogenic fat cells that convert chemical energy into heat are present in both mice and humans. Recent years have witnessed great advances in our understanding of the regulation of these adipocytes and an increased appreciation of the potential these cells have to counteract obesity. We summarize recent efforts to understand the formation of these fat cells and critically review genetic models and other experimental tools currently available to further investigate the development and activation of both classical brown and inducible beige fat cells. We also discuss recent discoveries about the epigenetic regulation of these adipocytes, and finally present emerging evidence revealing the metabolic impacts of thermogenic fat in humans.

Developmental Latent Patterns of Identification as Mostly Heterosexual Versus Lesbian, Gay, or Bisexual.

Scant research exists on the development of mostly heterosexual identity, the largest sexual orientation minority subgroup. We used longitudinal latent class analysis to characterize the patterns of identification with lesbian, gay, bisexual (LGB), or mostly heterosexual identities from ages 12 to 23 in 13,859 youth (57% female) in a U.S. national cohort. Three classes emerged: completely heterosexual (88.2%), mostly heterosexual (9.5%), and LGB (2.4%). LGB class youth generally identified with sexual minority identities by ages 12-17. In contrast, mostly heterosexual class youth identified with sexual minority identities gradually, with steady increases in endorsement starting at the age of 14. Developmental implications of these differential patterns are discussed.

Food ordering for children in restaurants: multiple sources of influence on decision making.

OBJECTIVE: Restaurants are playing an increasingly important role in children's dietary intake. Interventions to promote healthy ordering in restaurants have primarily targeted adults. Much remains unknown about how to influence ordering for and by children. Using an ecological lens, the present study sought to identify sources of influence on ordering behaviour for and by children in restaurants. DESIGN: A mixed-methods study was conducted using unobtrusive observations of dining parties with children and post-order interviews. Observational data included: child's gender, person ordering for the child and server interactions with the dining party. Interview data included: child's age, restaurant visit frequency, timing of child's decision making, and factors influencing decision making. SETTING: Ten independent, table-service restaurants in San Diego, CA, USA participated. SUBJECTS: Complete observational and interview data were obtained from 102 dining parties with 150 children (aged 3-14 years). RESULTS: Taste preferences, family influences and menus impacted ordering. However, most children knew what they intended to order before arriving at the restaurant, especially if they dined there at least monthly. Furthermore, about one-third of children shared their meals with others and all shared meals were ordered from adult (v. children's) menus. Parents placed most orders, although parental involvement in ordering was less frequent with older children. Servers interacted frequently with children but generally did not recommend menu items or prompt use of the children's menu. CONCLUSIONS: Interventions to promote healthy ordering should consider the multiple sources of influence that are operating when ordering for and by children in restaurants.

A restaurant-based intervention to promote sales of healthy children's menu items: the Kids' Choice Restaurant Program cluster randomized trial.

BACKGROUND: Away-from-home eating is an important dietary behavior with implications on diet quality. Thus, it is an important behavior to target to prevent and control childhood obesity and other chronic health conditions. Numerous studies have been conducted to improve children's dietary intake at home, in early care and education, and in schools; however, few studies have sought to modify the restaurant food environment for children. This study adds to this body of research by describing the development and launch of an innovative intervention to promote sales of healthy children's menu items in independent restaurants in Southern California, United States. METHODS: This is a cluster randomized trial with eight pair-matched restaurants in San Diego, California. Restaurants were randomized to a menu-only versus menu-plus intervention condition. The menu-only intervention condition involves manager/owner collaboration on the addition of pre-determined healthy children's menu items and kitchen manager/owner collaboration to prepare and plate these items and train kitchen staff. The menu-plus intervention condition involves more extensive manager/owner collaboration and kitchen staff training to select, prepare, and plate new healthy children's menu items, and a healthy children's menu campaign that includes marketing materials and server training to promote the items. The primary outcome is sales of healthy children's menu items over an 18-week period. In addition, dining parties consisting of adults with children under 18 years of age are being observed unobtrusively while ordering and then interviewed throughout the 18-week study period to determine the impact of the intervention on ordering behaviors. Manager/owner interviews and restaurant audits provide additional evidence of impact on customers, employees, and the restaurant environment. Our process evaluation assesses dose delivered, dose received, and intervention fidelity. DISCUSSION: Successful recruitment of the restaurants has been completed, providing evidence that the restaurant industry is open to working on the public health challenge of childhood obesity. Determining whether a restaurant intervention can promote sales of healthy children's menu items will provide evidence for how to create environments that support the healthy choices needed to prevent and control obesity. Despite these strengths, collection of sales data that will allow comprehensive analysis of intervention effects remains a challenge. TRIAL REGISTRATION: NCT02511938.

Linalool is a PPARα ligand that reduces plasma TG levels and rewires the hepatic transcriptome and plasma metabolome.

We investigated the hypotriglyceridemic mechanism of action of linalool, an aromatic monoterpene present in teas and fragrant herbs. Reporter gene and time-resolved fluorescence resonance energy transfer assays demonstrated that linalool is a direct ligand of PPARα. Linalool stimulation reduced cellular lipid accumulation regulating PPARα-responsive genes and significantly induced FA oxidation, and its effects were markedly attenuated by silencing PPARα expression. In mice, the oral administration of linalool for 3 weeks reduced plasma TG concentrations in Western-diet-fed C57BL/6J mice (31%, P < 0.05) and human apo E2 mice (50%, P < 0.05) and regulated hepatic PPARα target genes. However, no such effects were seen in PPARα-deficient mice. Transcriptome profiling revealed that linalool stimulation rewired global gene expression in lipid-loaded hepatocytes and that the effects of 1 mM linalool were comparable to those of 0.1 mM fenofibrate. Metabolomic analysis of the mouse plasma revealed that the global metabolite profiles were significantly distinguishable between linalool-fed mice and controls. Notably, the concentrations of saturated FAs were significantly reduced in linalool-fed mice. These findings suggest that the appropriate intake of a natural aromatic compound could exert beneficial metabolic effects by regulating a cellular nutrient sensor.

Cyanidin is an agonistic ligand for peroxisome proliferator-activated receptor-alpha reducing hepatic lipid.

To investigate the underlying mechanism of targets of cyanidin, a flavonoid, which exhibits potent anti-atherogenic activities in vitro and in vivo, a natural chemical library that identified potent agonistic activity between cyanidin and peroxisome proliferator-activated receptors (PPAR) was performed. Cyanidin induced transactivation activity in all three PPAR subtypes in a reporter gene assay and time-resolved fluorescence energy transfer analyses. Cyanidin also bound directly to all three subtypes, as assessed by surface plasmon resonance experiments, and showed the greatest affinity to PPARα. These effects were confirmed by measuring the expression of unique genes of each PPAR subtype. Cyanidin significantly reduced cellular lipid concentrations in lipid-loaded steatotic hepatocytes. In addition, transcriptome profiling in lipid-loaded primary hepatocytes revealed that the net effects of stimulation with cyanidin on lipid metabolic pathways were similar to those elicited by hypolipidemic drugs. Cyanidin likely acts as a physiological PPARα agonist and potentially for PPARß/δ and γ, and reduces hepatic lipid concentrations by rewiring the expression of genes involved in lipid metabolic pathways.

Structural stigma and cigarette smoking in a prospective cohort study of sexual minority and heterosexual youth.

BACKGROUND: Sexual minority youth are more likely to smoke cigarettes than heterosexuals, but research into the determinants of these disparities is lacking. PURPOSE: This study aimed to examine whether exposure to structural stigma predicts cigarette smoking in sexual minority youth. METHODS: Prospective data from adolescents participating in the Growing Up Today Study (2000-2005) were utilized. RESULTS: Among sexual minority youth, living in low structural stigma states (e.g., states with non-discrimination policies inclusive of sexual orientation) was associated with a lower risk of cigarette smoking after adjustment for individual-level risk factors (relative risk [RR] = 0.97; 95 % confidence interval [CI], 0.96, 0.99; p = 0.02). This association was marginally significant after additional controls for potential state-level confounders (RR = 0.97; 95 % CI, 0.93, 1.00; p = 0.06). In contrast, among heterosexual youth, structural stigma was not associated with past-year smoking rates, documenting specificity of these effects to sexual minority youth. CONCLUSIONS: Structural stigma represents a potential risk factor for cigarette smoking among sexual minority adolescents.

trans-Caryophyllene is a natural agonistic ligand for peroxisome proliferator-activated receptor-α.

Intake of dietary aroma compounds may regulate cellular lipid metabolism. We demonstrated that trans-caryophyllene, a flavor compound in plant foods and teas, activates peroxisome proliferator-activated receptor (PPAR)-α through direct interaction with the ligand-binding domain of PPAR-α. The agonistic activity of trans-caryophyllene was investigated by the luciferase reporter assay, surface plasmon resonance, and time-resolved fluorescence resonance energy transfer assay. Following the stimulation of cells with trans-caryophyllene, intracellular triglyceride concentrations were significantly reduced by 17%, and hepatic fatty acid uptake was significantly increased by 31%. The rate of fatty acid oxidation was also significantly increased. The expressions of PPAR-α and its target genes and proteins in fatty acid uptake and oxidation were significantly up-regulated as well. In HepG2 cells transfected with small interfering RNA of PPAR-α, the effects of trans-caryophyllene on PPAR-α responsive gene expressions, intracellular triglyceride, fatty acid uptake and oxidation were disappeared. These results indicate that the aroma compound, trans-caryophyllene, is PPAR-α agonist thus regulates cellular lipid metabolism in PPAR-α dependent manners.

NT-PGC-1α protein is sufficient to link ß3-adrenergic receptor activation to transcriptional and physiological components of adaptive thermogenesis.

PGC-1α is an inducible transcriptional coactivator that regulates cellular energy metabolism and adaptation to environmental and nutritional stimuli. In tissues expressing PGC-1α, alternative splicing produces a truncated protein (NT-PGC-1α) corresponding to the first 267 amino acids of PGC-1α. Brown adipose tissue also expresses two novel exon 1b-derived isoforms of PGC-1α and NT-PGC-1α, which are 4 and 13 amino acids shorter in the N termini than canonical PGC-1α and NT-PGC-1α, respectively. To evaluate the ability of NT-PGC-1α to substitute for PGC-1α and assess the isoform-specific role of NT-PGC-1α, adaptive thermogenic responses of adipose tissue were evaluated in mice lacking full-length PGC-1α (FL-PGC-1(-/-)) but expressing slightly shorter but functionally equivalent forms of NT-PGC-1α (NT-PGC-1α(254)). At room temperature, NT-PGC-1α and NT-PGC-1α(254) were produced from conventional exon 1a-derived transcripts in brown adipose tissue of wild type and FL-PGC-1α(-/-) mice, respectively. However, cold exposure shifted transcription to exon 1b, increasing exon 1b-derived mRNA levels. The resulting transcriptional responses produced comparable increases in energy expenditure and maintenance of core body temperature in WT and FL-PGC-1α(-/-) mice. Moreover, treatment of the two genotypes with a selective ß(3)-adrenergic receptor agonist produced similar increases in energy expenditure, mitochondrial DNA, and reductions in adiposity. Collectively, these findings illustrate that the transcriptional and physiological responses to sympathetic input are unabridged in FL-PGC-1α(-/-) mice, and that NT-PGC-1α is sufficient to link ß(3)-androgenic receptor activation to adaptive thermogenesis in adipose tissue. Furthermore, the transcriptional shift from exon 1a to 1b supports isoform-specific roles for NT-PGC-1α in basal and adaptive thermogenesis.

Induction of ABCA1 and ABCG1 expression by the liver X receptor modulator cineole in macrophages.

We investigated the effect of cineole on the expression of genes related to reverse cholesterol transport and hepatic fatty acid metabolism. Cineole, a small aroma compound in teas and herbs, significantly stimulated the transactivation of liver X receptor modulator (LXR)-α and LXR-ß. The mRNA and protein expression of LXRs and their target genes, including ABCA1 and ABCG1, was significantly increased in macrophages stimulated with cineole. This led to the subsequent removal of cholesterol from the cells. Interestingly, cineole showed tissue-selective LXR induction: hepatocytes stimulated with cineole showed significantly reduced expression of LXR-α and LXR-α-responsive genes, including FAS and SCD-1 (P <0.05). Accordingly, hepatocytes treated with cineole displayed reduced cellular lipid accumulation compared with control cells, as assessed by Oil Red O lipid staining and cholesterol quantification. These results suggest that cineole is a selective LXR modulator that regulates the expression of key genes in reverse cholesterol transport in macrophages without inducing lipogenesis in hepatocytes. This selective LXR modulator may have practical implications for the development of hypocholesterolemic or anti-atherosclerotic agents and also suggests.

Cyanidin, a natural flavonoid, is an agonistic ligand for liver X receptor alpha and beta and reduces cellular lipid accumulation in macrophages and hepatocytes.

Cyanidin, a natural flavonoid abundant in fruits and vegetables, is known to regulate cellular lipid metabolism; however, its underlying mechanism of action and protein targets remain unknown. Here, the ligand binding activity of cyanidin on liver X receptors (LXRs) was investigated utilizing surface plasmon resonance and time-resolved fluorescence energy transfer (TR-FRET) analyses. LXRs are nuclear receptors which function as critical transcription factors in the regulation of cellular lipid and glucose metabolism. This includes the stimulation of high-density-lipoprotein synthesis and activation of reverse cholesterol transport. The present findings show that cyanidin induces the transactivation of LXRs and binds directly to the ligand-binding domain of both LXRα and LXRß with dissociation constants of 2.2 and 73.2µM, respectively. Cell-free FRET analysis demonstrated that cyanidin induces the recruitment of co-activator peptide for LXRα and LXRß with EC50 of 3.5µM and 125.2µM, respectively. In addition, intracellular cholesterol and triglyceride (TG) concentrations were reduced in macrophages following cyanidin stimulation. In cultured hepatocytes, cyanidin mildly induced SREBP1c gene expression but marginally affected cellular TG concentrations as well as reduced cellular cholesterol accumulations which activated the expression of genes for reverse cholesterol transport. Two cyanidin metabolites, procatechic acid and phloroglucinaldehyde, did not directly bind or activate LXRs. These results demonstrate that cyanidin is a direct ligand for both LXRα and LXRß, suggesting that cyanidin may operate, at least in part, through modulation of cellular LXR activity.

Sexual-orientation disparities in cigarette smoking in a longitudinal cohort study of adolescents.

INTRODUCTION: Youths with a minority sexual orientation (i.e., gay, lesbian, bisexual, and mostly heterosexual) are at high risk for cigarette smoking. We examined sexual-orientation disparities in smoking during adolescence and emerging adulthood and investigated the role of age at first smoking in contributing to smoking disparities. METHODS: We used data from the Growing Up Today Study, a large longitudinal cohort of adolescents followed from ages 12 to 24 years (N = 13,913). Self-administered questionnaires filled out annually or biennially assessed age at first smoking, current smoking, frequency of smoking, number of cigarettes smoked daily, and nicotine dependence. Proportional hazards survival analysis and repeated measures regression estimated sexual-orientation differences in smoking. RESULTS: Compared with completely heterosexuals, lesbian/gay, bisexual, and mostly heterosexual youths smoked their first cigarette at younger ages, were more likely to be current smokers, and had higher frequency of smoking. Among past-year smokers, sexual-minority females smoked more cigarettes daily and scored higher on nicotine dependence than completely heterosexual females. In some instances, gender and age modified relationships between sexual orientation and smoking, with relative risk accentuated in female sexual minorities and in sexual minorities during younger ages. Younger age of smoking onset contributed to elevated smoking in mostly heterosexuals and bisexuals, and to a lesser extent in lesbians, but not in gay males. CONCLUSIONS: Sexual-orientation minorities are at greater risk for smoking during adolescence and emerging adulthood than heterosexuals. Disparities are larger in females and evident in early adolescence. Prevention and cessation efforts should target this population, preferably beginning in early adolescence.

Lactate oxidase/vSIRPα conjugates efficiently consume tumor-produced lactates and locally produce tumor-necrotic H2O2 to suppress tumor growth.

Aggressive tumor formation often leads to excessive anaerobic glycolysis and massive production and accumulation of lactate in the tumor microenvironment (TME). To significantly curb lactate accumulation in TME, in this study, lactate oxidase (LOX) was used as a potential therapeutic enzyme and signal regulatory protein α variant (vSIRPα) as a tumor cell targeting ligand. SpyCatcher protein and SpyTag peptide were genetically fused to LOX and vSIRPα, respectively, to form SC-LOX and ST-vSIRPα and tumor-targeting LOX/vSIRPα conjugates were constructed via a SpyCatcher/SpyTag protein ligation system. LOX/vSIRPα conjugates selectively bound to the CD47-overexpressing mouse melanoma B16-F10 cells and effectively consumed lactate produced by the B16-F10 cells, generating adequate amounts of hydrogen peroxide (H2O2), which induces drastic necrotic tumor cell death. Local treatments of B16-F10 tumor-bearing mice with LOX/vSIRPα conjugates significantly suppressed B16-F10 tumor growth in vivo without any severe side effects. Tumor-targeting vSIRPα may allow longer retention of LOX in tumor sites, effectively consuming surrounding lactate in TME and locally generating adequate amounts of cytotoxic H2O2 to suppress tumor growth. The approach restraining the local lactate concentration and H2O2 in TME using LOX and vSIRPα could offer new opportunities for developing enzyme/targeting ligand conjugate-based therapeutic tools for tumor treatment.