The tripartite influence model (TIM) explains how socially-constructed appearance pressures shape body image ideals and subsequent disordered eating in diverse populations, including sexual minoritized men (SMM). Previous research on the TIM in SMM is cross-sectional. Given the implications of temporal precedence, the omission of longitudinal research on the TIM is a critical gap. Two hundred and twenty-five cisgender SMM (Mage=25.79) were recruited via Prolific at baseline. Participants completed surveys at baseline (T1), three-month follow-up (T2), and six-month follow-up (T3). Prospective serial mediation models examined T2 body-ideal internalization and T2 body dissatisfaction, or T2 appearance comparisons and T2 body dissatisfaction, as serial mediators of links between T1 appearance pressures and T3 disordered eating. Adjusting for baseline age, BMI, and the outcome variable (i.e., disordered eating), greater T1 appearance pressures was associated with greater T2 appearance comparisons (b=.20, p < .001), which was associated with greater T2 thinness-oriented body dissatisfaction (b=.25, p = .02) and, in turn, greater T3 thinness-oriented disordered eating (b=.15, p = .004). Furthermore, greater T1 appearance pressures was associated with greater T2 appearance comparisons (b=.25, p < .001), which was associated with greater T2 muscularity-oriented body dissatisfaction (b=.60, p = .001) and, in turn, greater T3 muscularity-oriented disordered eating (b=.12, p = .02). T2 body-ideal internalization did not significantly mediate prospective associations between appearance pressures and disordered eating. Appearance comparisons and body dissatisfaction may explain prospective links between appearance pressures and disordered eating in SMM. Future research considering unique body-ideal internalization manifestations (thinness and muscularity) may support revisions of the TIM as an explanatory framework of disordered eating among SMM.
Abstract Background Comprehending sex differences in stress vulnerability and the associated neurocircuitry has been elusive until the development of a method for investigating social defeat in female mice. Methods The Stress Alternatives Model (SAM) uses conditioning-induced agonistic behavior from novel male aggressors to separate distinct phenotypes characterized by stress-resilient active avoidance (Escape) or vulnerability (no Escape = Stay). Results Unlike males, females predominantly display Escape behavior, which is reversible (to Stay) by adding more social stress to behavioral environments. Despite this, females exhibit both stress-resilient and vulnerable phenotypic segregation. Stress-vulnerable females exhibit double conditioning-induced corticosterone secretion, more contextual fear conditioning, and reduced social preference. Systemic and intra-BLA injections of Orx2R or α2 antagonists resulted in slower escape (EscapeS), increased social avoidance, as well as increased cued and contextual freezing in stress-vulnerable females. Neurons in BLA express Orx2R mRNA (Hcrtr2) predominantly in cholecystokinin-positive GABA neurons. In slower escape (EscapeS) females expression of Hcrtr2 and Adra2a in BLA is elevated. Conclusions Female and male mice exposed to social stress exhibit distinct behavioral adaptations, but similarly, separate into resilient and susceptible subpopulations. Inhibiting Orx2R promotes stress-vulnerable behavior in females, and modifies transcription in BLA microcircuits, suggesting a role for Orx2R defining stress behavior.
G protein α-subunit (Gαs), encoded by GNAS, mediates G protein-coupled receptor (GPCR) signaling through the cAMP second messenger pathways, and plays a pivotal role in craniofacial morphogenesis and osteoblast differentiation. Craniosynostosis, one of the most prevalent craniofacial developmental anomalies, is characterized by the premature fusion of cranial sutures. Here, we identify germline heterozygous variants in GNAS as a novel genetic cause of craniosynostosis. Affected individuals presented with multiple-suture synostosis, recognizable dysmorphic features, brachydactyly, short stature, with or without hormone resistance. We identified 3 de novo missense variants (c.286A > G;p.K96E, c.758A > G;p.Y253C, and c.691C > T;p.R231C) and 1 maternally inherited splicing variant (c.1039-2A > G). Functional analyses using bioluminescence resonance energy transfer assays compared these variants to well-characterized activating variants p.R201H and p.Q227L. All tested variants impaired trimeric G protein assembly to varying degrees and exhibited reduced coupling with PTHR1. While the p.R201H and p.Q227L variants induced excessive cAMP production, the craniosynostosis-associated variants either displayed decreased basal cAMP levels or reduced agonist-induced cAMP production compared to WT, suggesting an inactivating nature. In zebrafish models, heterozygous gnas inactivation recapitulated human phenotypes, including multiple-suture synostosis, craniofacial abnormalities, and short stature. Mechanistically, GNAS knockdown in human MSCs promoted osteogenic differentiation through disrupted cAMP-cAMP response element-binding protein signaling, which relieved SMAD6-mediated repression of RUNX2 transcription. This study establishes inactivating GNAS variants as a genetic cause of craniosynostosis, and uncovers a disease mechanism linking G protein inactivation to craniosynostosis through defective GPCR signal transduction.
Abstract Primary cilia are conserved, antenna-like organelles that protrude from the surface of most vertebrate cells. They function as specialized sensory compartments that detect extracellular cues and convert them into downstream signaling events essential for embryogenesis and tissue homeostasis. The cilium is physically separated from the cytoplasm and contains specialized subcompartments, including the basal body, the transition zone, and the ciliary tip, all of which are critical for its structure, function, and signaling output. Mutations in ciliary genes that disrupt these subcompartments can lead to a wide range of developmental disorders collectively known as ciliopathies. Analysis of these submicron ciliary domains is often time-consuming, repetitive, and prone to user bias. In addition, automated tools for subdomain analysis remain limited, requiring the development of novel, unbiased, and precise segmentation tools applicable to both healthy and pathological conditions. Here, we introduce Cilia SubQ, a versatile suite of flexible pipelines for ZEISS arivis Pro that enables segmentation of the primary cilium, pericentriolar material, basal body, transition zone, and ciliary tip, achieving an approximately eightfold reduction in analysis time with controlled manual intervention. These pipelines are built on our newly developed Cilia.AI, a machine-learning model that recognizes primary cilia with minimal manual correction. The suite also includes a validated script for generating kymographs to assess intraflagellar transport (IFT) dynamics in mammalian primary cilia. Cilia SubQ files and video tutorials are publicly available through the Open Science Framework (OSF) at https://osf.io/hm38f/ . Together, the Cilia SubQ pipelines provide batch, high-throughput, and reproducible quantification of primary cilia and ciliary subdomains, delivering greater data output with reduced hand-on analysis.
OBJECTIVE:While loss of control (LOC) eating is associated with poor outcomes following metabolic and bariatric surgery (MBS), the mechanisms driving it are less understood. This study used momentary, naturalistic data to examine glucose as a biological correlate of LOC eating after Roux-en-Y gastric bypass (RYGB). METHOD:Participants (45 adults one-year post-RYGB) completed 10 days of ecological momentary assessment (EMA) while wearing a continuous glucose monitor (CGM). Eating episodes reported in EMA were time-matched to CGM readings 3 hours before and after eating episodes. Four CGM metrics (mean, variability, time in hyper- and hypo-glycaemia) were used in multilevel models to test whether glucose functioning was a significant antecedent and/or consequence of LOC eating. RESULTS:Greater mean glucose levels and variability each significantly predicted engagement in an eating episode, while more time spent in hyperglycemia predicted the absence of eating. Significantly higher mean glucose was observed after eating. No glucose metric specifically predicted engagement in LOC eating; however, LOC eating resulted in significantly greater glucose variability. CONCLUSIONS:Glucose level and variability predicted subsequent eating, but not LOC eating. However, LOC eating was associated with subsequent glucose variability, which might help explain how LOC eating is associated with poorer outcomes following RYGB.
