The identification of men motivated and able to afford protection for group members would have favored perceptual awareness toward morphological features diagnostic of their formidability. Within this calculus for coalitional decision-making could be an interest in identifying men especially capable of protecting offspring, an advantage both for men and women in identifying suitable mates and safe allies. One route through which formidability inferences emerge is facial width-to-height ratio (fWHR), a facial structure that heuristically informs perceptions of men’s physical prowess based on various sexually selected components. We conducted four experiments to determine how fWHR informs perceptions of men’s parental abilities and motives. Perceivers ascribed more effectiveness in protecting offspring in high-fWHR men (Study 1) and chose them more readily for protective roles (Study 2). Inferences of men’s paternal ability tracked both configural and featural processing (Study 3) and expected motivations for protection (Study 4). Results contribute to a functional perspective of how fWHR informs perceptions of motivational costs and benefits in parenting for men.

Apolipoprotein AV (APOA5) regulates intravascular triglyceride metabolism by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its ability to unfold the native conformation of lipoprotein lipase (LPL). LPL unfolding results in loss of catalytic activity and the detachment of LPL from the surface of cells. An APOA5 truncation mutation (identified in two patients with hypertriglyceridemia) had suggested that the last 35 amino acids of APOA5 are important for its function. We reasoned that a monoclonal antibody (mAb) against carboxyl-terminal sequences in APOA5 could clarify functionally important amino acid residues in APOA5 and assist in elucidating the mechanism by which APOA5 regulates plasma triglyceride metabolism. Because carboxyl-terminal APOA5 sequences are evolutionarily conserved, we began by screening a human Fab bacteriophage library for binders of carboxyl-terminal APOA5 sequences. We identified one such binder and used phage DNA sequences to build a chimeric IgG1 mAb (IBA707) against APOA5. The binding of IBA707 to APOA5 was abolished by nonconservative amino acid substitutions in conserved sequences (residues L337-I348) within a C-terminal α-helix in APOA5. The same substitutions disrupted APOA5's ability to bind and inhibit ANGPTL3/8 activity. IBA707-mediated blockade of APOA5 function reduced intracapillary LPL levels and triggered elevated plasma levels of triglycerides and ANGPTL3/8 in both fasted and refed mice. IBA707 was cleared rapidly from the plasma in Apoa5+/+ mice but slowly in Apoa5-/- mice. Our studies identified functionally important amino acids in APOA5 and revealed that APOA5 controls plasma triglyceride metabolism in part by modulating plasma levels of ANGPTL3/8.

In peripheral tissues, lipoprotein lipase (LPL) is secreted by parenchymal cells (adipocytes, myocytes) into the interstitial spaces, where it is captured by GPIHBP1 (a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells) and escorted to the luminal surface of capillaries. The LPL inside capillaries hydrolyzes glycerolipids in the plasma lipoproteins, releasing fatty acids for parenchymal cells. In the central nervous system, LPL is synthesized by multiple cell types [e.g., microglia, oligodendrocyte precursor cells (OPCs)] and secreted into the interstitium, but a binding site for the LPL has never been identified. By examining single nuclei RNA-seq databases of the human brain, we found that GPIHBP1 is expressed by oligodendrocytes but not by OPCs. This gene-expression profile (high in oligodendrocytes, low in OPCs) is also observed in genes for myelin structural proteins, fatty acid binding and transport proteins, and lipid biosynthetic enzymes. GPIHBP1 expression in oligodendrocytes was confirmed by in situ hybridization studies of human brain and by immunohistochemical staining. Of note, GPIHBP1 and LPL are colocalized on oligodendrocytes in the human brain. Our findings identify GPIHBP1 as a principal binding site for interstitial LPL in the human brain and suggest that GPIHBP1-bound LPL could hydrolyze interstitial lipids and thereby supply oligodendrocytes with fatty acid nutrients.

Fenofibrate and other fibrates are peroxisome proliferator-activated receptor alpha agonists that are used to lower plasma triglyceride (TG) levels. Although fibrates are effective in decreasing TG, their ability to reduce adverse cardiovascular events and cardiovascular mortality in clinical trials has been disappointing. Peroxisome proliferator-activated receptor alpha agonists influence the expression of dozens of genes, but the mechanisms by which they lower TG levels are incompletely understood. Apolipoprotein A5 (APOA5) and angiopoietin-like proteins 3, 4, and 8 (ANGPTL3/4/8) are important regulators of intravascular TG metabolism. To explore if their regulation might explain the TG-lowering effect of fibrates, we examined the impact of fenofibrate on the expression of APOA5 and the ANGPTL3/4/8 proteins in mice and humans. In WT mice, fenofibrate reduced plasma TG levels, increased Angptl4 and Angptl3 transcripts in the liver, and reduced Angptl8 and Apoa5 transcripts. Fenofibrate also decreased plasma APOA5 levels and increased levels of ANGPTL3, ANGPTL3/8, ANGPTL4/8, and the C-terminal domain of ANGPTL4 (CD-ANGPTL4). These changes would be predicted to increase rather than decrease TG levels. The TG reduction by fenofibrate was maintained in Apoa5-deficient mice, further indicating that APOA5 is not involved in TG lowering by fenofibrate. In humans, fenofibrate reduced TG without increasing APOA5 levels or reducing ANGPTL3/8 levels. In addition, fenofibrate treatment increased levels of ANGPTL3, ANGPTL4/8, and CD-ANGPTL4. The collective human and mouse data suggest that APOA5 and ANGPTL3/4/8 proteins do not mediate fenofibrate-induced TG lowering. Our findings are noteworthy because elevated levels of ANGPTL3, ANGPTL4/8, and CD-ANGPTL4 are associated with increased cardiovascular mortality.

Abstract Endolysosomal membrane damage is a detrimental process in mammalian cells that results in leakage of the luminal contents into the cytosol. However, the nature and extent of the leakage during membrane damage is unknown. Here, we show that endomembrane damage induces the rapid formation of intraluminal condensates in endolysosomes. A subset of resident luminal proteins undergo spatially coordinated condensation upon endomembrane damage. Electron microscopy reveals distinct luminal morphology, and cryo-electron tomography confirms the condensed ultrastructure in their native state. Condensate formation occurs across mechanistically distinct modes of membrane injury and is reversibly dissociated upon lysosomal recovery. Remarkably, these condensates impose a previously unrecognised barrier to endolysosomal escape of therapeutic oligonucleotides. Despite endomembrane damage, luminal oligonucleotide therapeutics are sequestered in damaged endolysosomes through condensate-mediated biophysical immobilisation. Targeting condensate sequestration could represent a novel strategy to improve oligonucleotide-based therapeutics.

Understanding how osteoblasts build and remodel bone matrix in vivo remains a fundamental challenge because cellular metabolism and matrix turnover are difficult to resolve across time and space within mineralized tissues. Here, we developed an integrated imaging platform combining stable isotope labeling with correlative electron microscopy and nanoscale secondary ion mass spectrometry (NanoSIMS) to visualize bone cell metabolism and matrix dynamics at nanometer resolution in vivo. This approach revealed rapid incorporation of dietary amino acids into osteoblast subcellular compartments within minutes of oral administration, followed by deposition of newly labeled extracellular matrix within hours. By linking elemental composition, isotope incorporation, and ultrastructure, we further show that cellular phosphorus signal is associated with early osteoblast amino acid incorporation. Multiday labeling revealed that newly deposited matrix is spatially associated with local osteocyte process architecture. Long-term amino acid tracing uncovered localized matrix turnover at osteocyte and osteoclast interfaces, including osteocyte-associated pericellular matrix remodeling and osteoclast association with newly formed, old, and mixed matrix regions. Finally, aging was associated with reduced osteoblast amino acid incorporation, diminished matrix deposition, and impaired osteocyte process-associated activity. Together, this work establishes a high-resolution platform for linking bone cell metabolism with matrix deposition and turnover in vivo, providing a broadly adaptable strategy to investigate skeletal aging, tissue remodeling, and metabolic dysfunction in disease.

Genetic and dietary cues are known drivers of obesity, yet how they converge at the molecular level is incompletely understood. Here we show that PPARγ supports hypertrophic expansion of adipose tissue via transcriptional control of LPCAT3, an endoplasmic reticulum (ER)-resident O-acyltransferase that selectively enriches diet-derived omega-6 polyunsaturated fatty acids (n-6 PUFAs) in the membrane lipidome. In mice fed a high-fat diet, lowering membrane n-6 PUFA levels through genetic or dietary interventions results in aberrant adipose triglyceride (TG) turnover, ectopic fat deposition and insulin resistance. Additionally, we detail a non-canonical adaptive response in ‘lipodystrophic’ Lpcat3–/– adipose tissues that engages a futile lipid cycle to increase metabolic rate and offset lipid overflow to ectopic sites. Live-cell imaging, lipidomics and molecular dynamics simulations reveal that adipocyte LPCAT3 activity enriches n-6 arachidonate in the phosphatidylethanolamine (PE)-dense ER–lipid droplet interface. Functionally, this localized PE remodelling optimizes TG storage by driving the formation of large droplets that exhibit greater resistance to adipose TG lipase activity. These findings highlight the PPARγ–LPCAT3 axis as a mechanistic link between dietary n-6 PUFA intake, adipose expandability and systemic energy balance. Dietary n-6 PUFAs enhance adipose tissue expandability through the PPARγ–LPCAT3 membrane remodelling axis.

In peripheral tissues, an endothelial cell (EC) protein, GPIHBP1, captures lipoprotein lipase (LPL) from the interstitial spaces and transports it to the capillary lumen. LPL mediates the margination of triglyceride-rich (TG-rich) lipoproteins (TRLs) along capillaries, allowing the lipolytic processing of TRLs to proceed. TRL-derived fatty acids are used for fuel in oxidative tissues or stored in adipose tissue. In mice, GPIHBP1 is absent from capillary ECs of the brain (which uses glucose for fuel); consequently, LPL and TRL margination are absent in mouse brain capillaries. However, because fatty acids were reported to play signaling roles in the brain, we hypothesized that LPL-mediated TRL processing might occur within specialized vascular beds within the central nervous system. Here, we show that GPIHBP1 is expressed in capillary ECs of human and mouse choroid plexus (ChP) and that GPIHBP1 transports LPL (produced by adjacent ChP cells) to the capillary lumen. The LPL in ChP capillaries mediates both TRL margination and processing. Intracapillary LPL and TRL margination are absent in the ChP of Gpihbp1-/- mice. GPIHBP1 expression, intracapillary LPL, and TRL margination were also observed in the median eminence and subfornical organ, circumventricular organs implicated in the regulation of food intake.

The intrinsic pathways that control membrane organization in immune cells and their impact on cellular functions are poorly defined. We found that the nonvesicular cholesterol transporter Aster-A linked plasma membrane (PM) cholesterol availability in CD4 T cells to systemic metabolism. Aster-A was recruited to the PM during T cell receptor (TCR) activation, where it facilitated the removal of accessible cholesterol. Loss of Aster-A increased cholesterol accumulation in the PM, which enhanced TCR nanoclustering and signaling. Aster-A associated with stromal interaction molecule 1 (STIM1) and negatively regulated calcium (Ca2+) flux. Aster-A deficiency promoted CD4 T cells to acquire a T helper 17 (TH17) phenotype and stimulated interleukin-22 production, which reduced intestinal fat absorption and conferred resistance to diet-induced obesity. These findings delineate how immune cell membrane homeostasis links to systemic physiology.

This study reanalyzed endothelial cell (EC) gene expression in the mouse aorta utilizing eight single-cell RNA-sequencing datasets. Contrary to the assumption that all ECs originated from the luminal surface, we identified two distinct sites of origin: aortic lumen (Cytl1-positive ECs) and peri-aortic microvascular (Gpihbp1-positive ECs). The proportions of these EC subtypes varied extensively across the eight datasets, likely due to differing experimental procedures. We deduced complete transcriptomes for each EC subtype, revealing differential gene expression and predicted functional properties. We provide marker lists and an accessible online database for gene-by-gene analysis to aid in correct cell identification and in gauging the impact of patho/physiological parameters on aortic EC gene expression.

Lipoprotein lipase (LPL) carries out the lipolytic processing of triglyceride-rich lipoproteins (TRL) along the luminal surface of capillaries. LPL activity is regulated by the angiopoietin-like proteins (ANGPTL3, ANGPTL4, ANGPTL8), which control the delivery of TRL-derived lipid nutrients to tissues in a temporal and spatial fashion. This regulation of LPL mediates the partitioning of lipid delivery to adipose tissue and striated muscle according to nutritional status. A complex between ANGPTL3 and ANGPTL8 (ANGPTL3/8) inhibits LPL activity in oxidative tissues, but its mode of action has remained unknown. Here, we used biophysical techniques to define how ANGPTL3/8 and ANGPTL3 interact with LPL and how they drive LPL inactivation. We demonstrate, by mass photometry, that ANGPTL3/8 is a heterotrimer with a 2:1 ANGPTL3:ANGPTL8 stoichiometry and that ANGPTL3 is a homotrimer. Hydrogen–deuterium exchange mass spectrometry (HDX-MS) studies revealed that ANGPTL3/8 and ANGPTL3 use the proximal portion of their N-terminal α-helices to interact with sequences surrounding the catalytic pocket in LPL. That binding event triggers unfolding of LPL’s α/β -hydrolase domain and irreversible loss of LPL catalytic activity. The binding of LPL to its endothelial transporter protein (GPIHBP1) or to heparan-sulfate proteoglycans protects LPL from unfolding and inactivation, particularly against the unfolding triggered by ANGPTL3. Pulse-labeling HDX-MS studies revealed that ANGPTL3/8 and ANGPTL3 catalyze LPL unfolding in an ATP-independent fashion, which categorizes these LPL inhibitors as atypical unfoldases. The catalytic nature of LPL unfolding by ANGPTL3/8 explains why low plasma concentrations of ANGPTL3/8 are effective in inhibiting a molar excess of LPL in capillaries.

Hutchinson-Gilford progeria syndrome (HGPS) is caused by progerin, an internally truncated prelamin A that does not undergo the ZMPSTE24 processing step that releases prelamin A’s farnesylated carboxyl terminus; consequently, progerin remains farnesylated. Progerin and full-length farnesyl-prelamin A are equivalent in their abilities to disrupt the nuclear lamina and trigger nuclear membrane ruptures and cell death, but they differ markedly in their abilities to cause arterial pathology. In HGPS mice (LmnaG609G), progerin causes loss of aortic smooth muscle cells (SMCs) by 12 weeks, whereas farnesyl-prelamin A in Zmpste24−/− mice does not trigger SMC loss—even at 21 weeks. In young mice, farnesyl-prelamin A levels in Zmpste24−/− aortas and progerin levels in LmnaG609G aortas are identical; however, progerin levels in LmnaG609G aortas increase progressively with age, whereas farnesyl-prelamin A levels in Zmpste24−/− aortas remain the same or decline. SMC loss in Zmpste24−/− aortas occurs only with supraphysiologic levels of prelamin A synthesis (mimicking the accumulation of progerin). AKT activity (which mediates prelamin A phosphorylation and triggers prelamin A turnover) is lower in LmnaG609G aortas than in wild-type or Zmpste24−/− aortas. Our studies show that the progressive accumulation of progerin in the aorta underlies the arterial pathology in HGPS.

Cold stress elicits dynamic remodeling of the mitochondrial lipidome in brown adipose tissue (BAT), marked by an increase in arachidonoyl-phosphatidylethanolamine (AA-PE). However, the function of membrane lipid rewiring in thermoregulatory physiology has been a longstanding mystery. Here, we identify LPCAT3 as a cold-regulated O-acyltransferase driving the highly selective accrual of AA-PE in BAT mitochondria. Lipid-based proteomics, molecular dynamics simulations, and bioenergetic analyses reveal that AA-PE partitions at the COX4I1 interface of the Cytochrome c oxidase complex, enhancing electron transport chain (ETC) efficiency. Accordingly, fat-specific Lpcat3 -knockout mice have defects in respiratory-dependent BAT thermogenesis and cold tolerance, despite intact β-adrenergic signaling and UCP1 function. Under cold acclimation, Lpcat3 -/- BAT exhibits ETC dysfunction and activation of the integrated stress-response. Thus, our study illuminates a cold-regulated lipid-protein interaction as a gating factor in UCP1-dependent thermogenesis.

The intrinsic pathways that control membrane organization in immune cells and the impact of such pathways on cellular function are not well defined. Here we report that the non-vesicular cholesterol transporter Aster-A links plasma membrane (PM) cholesterol availability in T cells to immune signaling and systemic metabolism. Aster-A is recruited to the PM during T-cell receptor (TCR) activation, where it facilitates the removal of newly generated "accessible" membrane cholesterol. Loss of Aster-A leads to excess PM cholesterol accumulation, resulting in enhanced TCR nano-clustering and signaling, and Th17 cytokine production. Finally, we show that the mucosal Th17 response is restrained by PM cholesterol remodeling. Ablation of Aster-A in T cells leads to enhanced IL-22 production, reduced intestinal fatty acid absorption, and resistance to diet-induced obesity. These findings delineate a multi-tiered regulatory scheme linking immune cell lipid flux to nutrient absorption and systemic physiology.

Aster proteins mediate the nonvesicular transport of cholesterol from the plasma membrane (PM) to the endoplasmic reticulum (ER). However, the importance of nonvesicular sterol movement for physiology and pathophysiology in various tissues is incompletely understood. Here we show that loss of Aster-B leads to diet-induced obesity in female but not in male mice, and that this sex difference is abolished by ovariectomy. We further demonstrate that Aster-B deficiency impairs nonvesicular cholesterol transport from the PM to the ER in ovaries in vivo, leading to hypogonadism and reduced estradiol synthesis. Female Aster-B-deficient mice exhibit reduced locomotor activity and energy expenditure, consistent with established effects of estrogens on systemic metabolism. Administration of exogenous estradiol ameliorates the diet-induced obesity phenotype of Aster-B-deficient female mice. These findings highlight the key role of Aster-B-dependent nonvesicular cholesterol transport in regulating estradiol production and protecting females from obesity.

Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5A35"). We found that wild- type (WT) human APOA5, but not APOA5A35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C- terminal amino acids ("APOA5A40"). Mouse WT- APOA5, but not APOA5A40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT- APOA5, but not APOA5A40, increased intracapillary LPL levels and reduced plasma TG levels in WT- APOA5, but not APOA5A40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C- terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.

To support in vivo and in vitro studies of intravascular triglyceride metabolism in mice, we created rat monoclonal antibodies (mAbs) against mouse LPL. Two mAbs, mAbs 23A1 and 31A5, were used to develop a sandwich ELISA for mouse LPL. The detection of mouse LPL by the ELISA was linear in concentrations ranging from 0.31 ng/ml to 20 ng/ml. The sensitivity of the ELISA made it possible to quantify LPL in serum and in both pre-heparin and post-heparin plasma samples (including in grossly lipemic samples). LPL mass and activity levels in the post-heparin plasma were lower in Gpihbp1−/− mice than in wild-type mice. In both groups of mice, LPL mass and activity levels were positively correlated. Our mAb-based sandwich ELISA for mouse LPL will be useful for any investigator who uses mouse models to study LPL-mediated intravascular lipolysis.

Apolipoprotein AV (APOA5) deficiency causes hypertriglyceridemia in mice and humans. For years, the cause remained a mystery, but the mechanisms have now come into focus. Here, we review progress in defining APOA5 's function in plasma triglyceride metabolism. Biochemical studies revealed that APOA5 binds to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppresses its ability to inhibit the activity of lipoprotein lipase (LPL). Thus, APOA5 deficiency is accompanied by increased ANGPTL3/8 activity and lower levels of LPL activity. APOA5 deficiency also reduces amounts of LPL in capillaries of oxidative tissues (e.g., heart, brown adipose tissue). Cell culture experiments revealed the likely explanation: ANGPTL3/8 detaches LPL from its binding sites on the surface of cells, and that effect is blocked by APOA5. Both the low intracapillary LPL levels and the high plasma triglyceride levels in Apoa5 - / - mice are normalized by recombinant APOA5. Carboxylterminal sequences in APOA5 are crucial for its function; a mutant APOA5 lacking 40-carboxyl-terminal residues cannot bind to ANGPTL3/8 and lacks the ability to change intracapillary LPL levels or plasma triglyceride levels in Apoa5 - / - mice. Also, an antibody against the last 26 amino acids of APOA5 reduces intracapillary LPL levels and increases plasma triglyceride levels in wild-type mice. An inhibitory ANGPTL3/8-specific antibody functions as an APOA5-mimetic reagent, increasing intracapillary LPL levels and lowering plasma triglyceride levels in both Apoa5 - / - and wild-type mice. That antibody is a potentially attractive strategy for treating elevated plasma lipid levels in human patients.

Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.

Four studies explore the role of perceptual fluency in attenuating bullshit receptivity, or the tendency for individuals to rate otherwise meaningless statements as "profound". Across four studies, we presented participants with a sample of pseudoprofound bullshit statements in either a fluent or disfluent font and found that overall, disfluency attenuated bullshit receptivity while also finding little evidence that this effect was moderated by cognitive thinking style. In all studies, we measured participants' cognitive reflection, need for cognition, faith in intuition, and superstitious beliefs. Superstition strongly predicted bullshit receptivity regardless of fluency. Inconclusive results were found for the remaining scales. Potential links for the role of perceptual disfluency in promoting analytic thinking are discussed.