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Deoxynivalenol (DON), a type B trichothecene mycotoxin contaminating grain, promotes nausea, emesis, and anorexia. With DON exposure, circulating levels of intestinally derived satiation hormones, including glucagon-like peptide 1 (GLP-1), are elevated. To directly test whether GLP-1 signaling mediates the effects of DON, we examined the response of GLP-1 or GLP-1R-deficient mice to DON injection. We found comparable anorectic and conditioned taste avoidance learning responses in GLP-1/GLP-1R-deficient mice compared with control littermates, suggesting that GLP-1 is not necessary for the effects of DON on food intake and visceral illness. We then used our previously published data from translating ribosome affinity purification with RNA sequencing (TRAP-seq) analysis of area postrema neurons that express the receptor for the circulating cytokine growth differentiation factor (GDF15), GDNF family receptor α-like (GFRAL). Interestingly, this analysis showed that a cell surface receptor for DON, a calcium-sensing receptor (CaSR), is heavily enriched in GFRAL neurons. Given that GDF15 potently reduces food intake and can cause visceral illness by signaling through GFRAL neurons, we hypothesized that DON may also signal by activating CaSR on GFRAL neurons. Indeed, circulating GDF15 levels are elevated after DON administration, but both GFRAL knockout and GFRAL neuron-ablated mice exhibited similar anorectic and conditioned taste avoidance responses compared with WT littermates. Thus, GLP-1 signaling and GFRAL signaling and neurons are not required for DON-induced visceral illness or anorexia.

Exercise is a first-line treatment for type 2 diabetes and preserves β-cell function by hitherto unknown mechanisms. We postulated that proteins from contracting skeletal muscle may act as cellular signals to regulate pancreatic β-cell function. We employed electric pulse stimulation (EPS) to induce contraction in C2C12 myotubes and found that treatment of β-cells with EPS-conditioned media (EPS-CM) enhanced glucose-stimulated insulin secretion (GSIS). Transcriptomics and subsequent targeted validation revealed Growth Differentiation Factor 15 (GDF15) as a central component of the skeletal muscle secretome. Exposure to recombinant GDF15 enhanced GSIS in cells, islets, and mice. GDF15 enhanced GSIS by upregulating the insulin secretion pathway in β-cells, which was abrogated in the presence of a GDF15 neutralizing antibody. The effect of GDF15 on GSIS was also observed in islets from GFRAL-deficient mice. Circulating GDF15 was incrementally elevated in patients with pre- and type 2 diabetes and positively associated with C-peptide in humans with overweight/obesity. Six weeks of high intensity exercise training increased circulating GDF15 concentrations, which positively correlated with improvements in β-cell function in patients with type 2 diabetes. Taken together, GDF15 can function as a contraction-induced protein that enhances GSIS through activating the canonical signaling pathway in a GFRAL-independent manner.

Obesity promotes triple-negative breast cancer (TNBC), and effective interventions are urgently needed to break the obesity-TNBC link. Epidemiologic studies indicate that bariatric surgery reduces TNBC risk, while evidence is limited or conflicted for weight loss via low-fat diet (LFD) or calorie restriction (CR). Using a murine model of obesity- driven TNBC, we compared the antitumor effects of vertical sleeve gastrectomy (VSG) with LFD, chronic CR, and intermittent CR. Each intervention generated weight and fat loss and suppressed tumor growth relative to obese mice (greatest suppression with CR). VSG and CR regimens exerted both similar and unique effects, as assessed using multi-omic approaches, in reversing obesity-associated transcriptional, epigenetic, secretome, and microbiota changes and restoring antitumor immunity. Thus, in a murine model of TNBC, bariatric surgery and CR each reverse obesity-driven tumor growth via shared and distinct antitumor mechanisms, and CR is superior to VSG in reversing obesity’s procancer effects.

The HPTN 071(PopART) study was a community-randomised trial in Zambia and South Africa, examining the impact of combination-prevention including universal testing and treatment (UTT), on HIV-incidence. This sub-study evaluated factors associated with IPV (physical and/or sexual) to identify differences by HIV status. During 2015-16, a random subset of adults who participated in the first year of the PopART intervention were recruited and standardised questionnaires were administered. Logistic regression was performed to estimate odds ratios of factors associated with IPV. Among700 women studied (300 HIV-negative;400 HIV-positive), ~ 20% reported experiencing physical and/or sexual violence in the last 12-months. Sexual violence was similar by HIV status, but physical violence and reporting both physical/sexual violence was more common among HIV-positive women. Spending nights away from the community in the last 12-months was associated with higher odds of IPV among both HIV-negative (aOR 3.17, 95% CI 1.02-9.81) and HIV-positive women (aOR 1.79, 95% CI 0.99-3.24). Among HIV-positive women, financial autonomy was associated with reduced IPV (aOR:0.41,95%CI:0.23-0.75) while pregnancy in the last 12-months (aOR 2.25, 95% CI 1.07-4.74), risk of alcohol dependence (aOR 2.75, 95% CI 1.51-5.00) and risk of mental distress (aOR 2.62, 95% CI 1.33-5.16) were associated with increased IPV. Among HIV-negative women reporting sex in the last 12-months, transactional sex (aOR 3.97, 95% CI 1.02-15.37) and not knowing partner's HIV status (aOR 3.01, 95% CI 1.24-7.29) were associated with IPV. IPV was commonly reported in the study population and factors associated with IPV differed by HIV status. The association of mobility with IPV warrants further research. The high prevalence of harmful alcohol use and mental distress, and their association with IPV among HIV-positive women require urgent attention.El estudio HPTN 071 (PopART) fue un ensayo aleatorio-comunitario realizado en Zambia y Sudáfrica, que examinó el impacto de la prevención combinada, incluyendo las pruebas y tratamiento universal (UTT), en la incidencia del VIH. Este subestudio evaluó los factores asociados con la IPV (físicos y / o sexuales) para identificar diferencias en el estado del VIH. Durante 2015-16, un subconjunto aleatorio de adultos fueron reclutados para participar en el primer año de intervención de PopART, donde se administraron cuestionarios estandarizados. Se realizó una regresión logística para estimar las ratios de probabilidad de los factores asociados con la VPI. Entre las700 mujeres estudiadas (300 VIH negativas; 400 VIH positivas), ~ 20% informó haber experimentado violencia física y / o sexual en los últimos 12 meses. La violencia sexual fue similar en cuanto al estado del VIH. La denuncia de violencia física y sexual fue más común entre las mujeres VIH positivas. Pasar noches fuera de la comunidad en los últimos 12 meses, se asoció con mayores probabilidades de VPI entre las mujeres VIH negativas (ORa 3,17, 95% IC 1,02–9,81) y las mujeres VIH positivas (ORa 1,79, 95% IC 0,99–3,24). Entre las mujeres VIH positivas, la autonomía financiera se asoció con una reducción de la VPI (ORa 0,41; IC del 95% 0,23-0,75) mientras que en el embarazo en los últimos 12 meses (ORa 2,25; IC del 95% 1,07–4,74), riesgo a la dependencia del alcohol (ORa 2,75% IC 1,51–5,00) y el riesgo de angustia mental (ORa 2,62% IC del 95% 1,33–5,16) se asociaron con un aumento de la VPI. Entre las mujeres VIH negativas que informaron haber tenido relaciones sexuales en los últimos 12 meses, el sexo transaccional (ORa 3.97, 95% CI 1.02–15.37) y el desconocimiento del estado de VIH de la pareja (ORa 3.01, 95% CI 1.24–7.29) se asociaron con IPV. La IPV fue notificada mayoritariamente en la población de estudio y los factores asociados con la IPV diferían según el estado del VIH. La asociación de la movilidad con la IPV justifica una mayor investigación. La alta prevalencia de l consumo nocivo de alcohol y la angustia mental, y su asociación con la VPI entre las mujeres seropositivas, requieren atención urgente.

Compelling evidence shows that glucagon-like peptide-1 (GLP-1) has a profound effect in restoring normoglycemia in type 2 diabetic patients by increasing pancreatic insulin secretion. Although L-cells are the primary source of circulating GLP-1, the current therapies do not target L-cells to increase GLP-1 levels. Our study aimed to determine the molecular underpinnings of GLP-1 secretion as an impetus to identify new interventions to target endogenous L-cells.We used genetic mouse models of intestine-specific overexpression of hypoxia-inducible factor (HIF)-1α and HIF-2α (VhlOur data show that intestinal HIF signaling improved glucose homeostasis in a GLP-1-dependent manner. Intestinal HIF potentiated GLP-1 secretion via the lipid sensor G-protein-coupled receptor (GPR)40 enriched in L-cells. We show that HIF-2α regulates GPR40 in L-cells and potentiates fatty acid-induced GLP-1 secretion via extracellular regulated kinase (ERK). Using a genetic model of intestine-specific overexpression of HIF-2α, we show that HIF-2α is sufficient to increase GLP-1 levels and attenuate diet-induced metabolic perturbations such as visceral adiposity, glucose intolerance, and hepatic steatosis. Lastly, we show that intestinal HIF-2α signaling acts as a priming mechanism crucial for postprandial lipid-mediated GLP-1 secretion. Thus, disruption of intestinal HIF-2α decreases GLP-1 secretion.In summary, we show that intestinal HIF signaling, particularly HIF-2α, regulates the lipid sensor GPR40, which is crucial for the lipid-mediated GLP-1 secretion, and suggest that HIF-2α is a potential target to induce endogenous GLP-1 secretion.

Growth differentiation factor 15 (GDF15), a TGFβ superfamily cytokine, acts through its receptor, cell line-derived neurotrophic factorfamily receptor α-like (GFRAL), to suppress food intake and promote nausea. GDF15 is broadly expressed at low levels but increases in states of disease such as cancer, cachexia, and sepsis. Whether GDF15 is necessary for inducing sepsis-associated anorexia and body weight loss is currently unclear. To test this we used a model of moderate systemic infection in GDF15KO and GFRALKO mice with lipopolysaccharide (LPS) treatment to define the role of GDF15 signaling in infection-mediated physiologic responses. Since physiological responses to LPS depend on housing temperature, we tested the effects of subthermoneutral and thermoneutral conditions on eliciting anorexia and inducing GDF15. Our data demonstrate a conserved LPS-mediated increase in circulating GDF15 levels in mouse, rat, and human. However, we did not detect differences in LPS-induced anorexia between WT and GDF15KO or GFRALKO mice. Furthermore, there were no differences in anorexia or circulating GDF15 levels at either thermoneutral or subthermoneutral housing conditions in LPS-treated mice. These data demonstrate that GDF15 is not necessary to drive food intake suppression in response to moderate doses of LPS. NEW & NOTEWORTHY Although many responses to LPS depend on housing temperature, the anorexic response to LPS does not. LPS results in a potent and rapid increase in circulating levels of GDF15 in mice, rats, and humans. Nevertheless, GDF15 and its receptor (GFRAL) are not required for the anorexic response to systemic LPS administration. The anorexic response to LPS likely involves a myriad of complex physiological alterations.

Vascular reactivity of adipose tissue (AT) is hypothesized to play an important role in the development of obesity. However, the exact role of vascular reactivity in the development of obesity remains unclear. In this study, we investigated the chronological changes in vascular reactivity and the microenvironments of the visceral AT (VAT) and subcutaneous AT (SAT) in lean and obese mice. Changes in blood flow levels induced by a β-adrenoceptor agonist (isoproterenol) were significantly lower in the VAT of the mice fed a high-fat diet (HFD) for 1 and 12 weeks than those in the VAT of the mice fed a low-fat diet (LFD) for the same period; no significant change was observed in the SAT of any mouse group, suggesting depot-specific vascular reactivity of AT. Moreover, the hypoxic area and the expression of genes associated with angiogenesis and macrophage recruitment were increased in the VAT (but not in the SAT) of mice fed an HFD for 1 week compared with mice fed an LFD. These changes occurred with no morphological changes, including those related to adipocyte size, AT vessel density, and the diameter and pericyte coverage of the endothelium, suggesting a determinant role of vascular reactivity in the type of AT remodeling. The suppression of vascular reactivity was accompanied by increased endothelin1 (Edn1) gene expression and extracellular matrix (ECM) stiffness only in the VAT, implying enhanced contractile activities of the vasculature and ECM. The results suggest a depot-specific role of vascular reactivity in AT remodeling during the development of obesity.

Previously we showed that mice lacking the protein optic atrophy 1 (OPA1 BKO) in brown adipose tissue (BAT) have induction of the activating transcription factor 4 (ATF4), which promotes fibroblast growth factor 21 (FGF21) secretion as a batokine. FGF21 increases metabolic rates at baseline conditions but is dispensable for the resistance to diet-induced obesity (DIO) reported in OPA1 BKO mice [1]. To determine alternative mediators of this phenotype, we performed transcriptome analysis, which revealed increased levels of growth differentiation factor 15 (GDF15) in BAT. To determine if ATF4 induction was mediated by the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), and to evaluate the contribution of GDF15 to the resistance to DIO, we selectively deleted PERK or GDF15 in OPA1 BKO mice. Mice lacking both OPA1 and PERK in BAT had preserved induction of ATF4. Importantly, simultaneous deletion of OPA1 and GDF15 partially reversed the resistance to diet-induced obesity and abrogated the improvements in glucose tolerance. Furthermore, GDF15 mediated cold-induced thermogenesis, likely via sympathetic activation of iWAT. Taken together, our data indicate that PERK is dispensable for ATF4 induction, but GDF15 contributes to the resistance to DIO, and is required for glucose homeostasis and thermoregulation in OPA1 BKO mice.

Bariatric surgery is still the most effective long-term weight-loss therapy. Recent data indicate that surgical outcomes may be affected by diurnal food intake patterns. In this study, we aimed to investigate how surgery-induced metabolic adaptations (i.e. weight loss) interact with circadian clock function. For that reason, vertical sleeve gastrectomy (VSG) was performed in obese mice and rhythms in behavior, tissue rhythmicity, and white adipose tissue transcriptome were evaluated. VSG under constant darkness conditions led to a maximum weight loss of 18% compared to a loss of 3% after sham surgery. Post-surgical weight development was characterized by two distinct intervals of catabolic and subsequent anabolic metabolic state. Locomotor activity was not affected. However, VSG significantly increased active phase meal frequency in the anabolic state. No significant effects on clock gene rhythmicity were detected in adrenal and white adipose tissue (WAT) explant cultures. Transcriptome rhythm analyses of subcutaneous WAT revealed a reduction of cycling genes after VSG (sham: 2493 vs VSG: 1013) independent of sustained rhythms in core clock gene expression. This may be a consequence of weight loss-induced morphological reconstruction of WAT that overwrites the direct influence of the local clock machinery on the transcriptome. However, VSG altered rhythmic transcriptional regulation of WAT lipid metabolism pathways. Thus, our data suggest a reorganization of diurnal metabolic rhythms after VSG downstream of the molecular clock machinery.

BACKGROUND: Accurate staging of newly diagnosed or recurrent malignancy is essential for effective treatment. An important first step in staging involves the use of PET/CT to identify areas of FDG avidity. PET/CT however has limitations, including false positive FDG uptake from benign causes. In this paper we characterize an uncommon yet clinically important cause of false positive PET/CTs, that of benign anthracotic lymphadenitis (BAL). We examine the clinical, radiographic and histologic characteristics of BAL in patients referred for endobronchial ultrasound (EBUS) guided biopsies and discuss its context in relation to existing literature. METHODS: We performed a retrospective observational case series of 20 patients who were referred for EBUS guided biopsies of PET positive mediastinal and hilar lymph nodes during the work-up or treatment of suspected malignancy. RESULTS: To be included, all patients received PET imaging as well as an EBUS guided biopsy of FDG avid lymph nodes which demonstrated anthracotic pigment as the only histologic abnormality. The key findings were that 90% of patients in this cohort were born outside of the US, 90% had bilateral FDG avid lymph nodes with an average standardized uptake value (SUV) of 7.9±2.2. Most patients, based on their history, had a likely exposure to biomass fuel or urban pollution. CONCLUSIONS: BAL may be an underrecognized cause for PET positive lymph nodes in patients undergoing work-up for malignancy. These findings support the importance of sampling mediastinal and hilar lymph nodes even when SUVs are highly suggestive of malignancy.

Obesity and its sequelae have a major impact on human health. The stomach contributes to obesity in ways that extend beyond its role in digestion, including through effects on the microbiome. Gastrokine-1 (GKN1) is an anti-amyloidogenic protein abundantly and specifically secreted into the stomach lumen. We examined whether GKN1 plays a role in the development of obesity and regulation of the gut microbiome. Gkn1−/− mice were resistant to diet-induced obesity and hepatic steatosis (high fat diet (HFD) fat mass (g) = 10.4 ± 3.0 (WT) versus 2.9 ± 2.3 (Gkn1−/−) p −/−) p −/− mice also exhibited increased expression of the lipid-regulating hormone ANGPTL4 in the small bowel. The microbiome of Gkn1−/− mice exhibited reduced populations of microbes implicated in obesity, namely Firmicutes of the class Erysipelotrichia. Altered metabolism consistent with use of fat as an energy source was evident in Gkn1−/− mice during the sleep period. GKN1 may contribute to the effects of the stomach on the microbiome and obesity. Inhibition of GKN1 may be a means to prevent obesity.

Bariatric surgery is the most effective treatment for obesity and its comorbidities. However, our understanding of the molecular mechanisms behind its beneficial effects is limited. Extracellular vesicles (EVs) comprise an important mode of intercellular communication. They carry nucleic acids, hormones, and signaling molecules and regulate multiple processes. Our aim was to test the role of EVs in the effects of vertical sleeve gastrectomy (VSG) using a mouse model. Small intestinal EVs were obtained from the mice that underwent VSG or control surgery and were on chow or high-fat diet or diet-restricted, and then they were subjected to the proteomic analysis. Enteroid and bacterial cultures were treated with EVs to evaluate their survival effect. A mouse cohort received intraduodenal administration of EVs from VSG or Sham mice for 10 days. Body weight, glucose metabolism, and intestinal morphology were evaluated. EVs were enriched in the intestinal lumen and mucus of VSG compared with Sham mice. Protein composition of VSG and Sham-derived EVs was highly distinct. When introduced into culture, VSG EVs decreased survival of intestinal enteroids and, conversely, promoted proliferation of bacteria. Mice administered with EVs obtained from VSG and Sham groups did not show differences in body weight, food intake, or glucose metabolism. Intestinal morphology was altered, as VSG EVs caused reduction of ileal villi length and decreased epithelial proliferation in the jejunum and ileum. VSG causes remodeling of intestinal EVs, which results in unique protein composition. VSG-derived EVs exhibit cytotoxic effects on epithelial cells and reduce proliferation of intestinal progenitor cells in mice. NEW & NOTEWORTHY This is the first study that investigates the impact of bariatric surgery on protein composition of intestinal extracellular vesicles. Extracellular vesicle composition is greatly altered after vertical sleeve gastrectomy and may potentially modulate various signaling pathways. In our study, extracellular vesicles from vertical sleeve gastrectomy-treated mice promote bacterial proliferation but exhibit cytotoxic effect on epithelial cells and reduce proliferation of intestinal progenitor cells in mice.

Growing evidence supports that pharmacological application of growth differentiation factor 15 (GDF15) suppresses appetite but also promotes sickness-like behaviors in rodents via GDNF family receptor α-like (GFRAL)-dependent mechanisms. Conversely, the endogenous regulation of GDF15 and its physiological effects on energy homeostasis and behavior remain elusive. Here we show, in four independent human studies that prolonged endurance exercise increases circulating GDF15 to levels otherwise only observed in pathophysiological conditions. This exercise-induced increase can be recapitulated in mice and is accompanied by increased Gdf15 expression in the liver, skeletal muscle, and heart muscle. However, whereas pharmacological GDF15 inhibits appetite and suppresses voluntary running activity via GFRAL, the physiological induction of GDF15 by exercise does not. In summary, exercise-induced circulating GDF15 correlates with the duration of endurance exercise. Yet, higher GDF15 levels after exercise are not sufficient to evoke canonical pharmacological GDF15 effects on appetite or responsible for diminishing exercise motivation., The physiological role of GDF15 remains poorly defined. Here, the authors show that circulating GDF15 increases in response to prolonged exercise, but that this exercise-induced GDF15, unlike pharmacological GDF15, does not affect post-exercise food intake or exercise motivation.

While numerous techniques can be used to measure and analyze insulin secretion in isolated islets in culture, assessments of insulin secretion in vivo are typically indirect and only semiquantitative. The CpepSfGFP reporter mouse line allows the in vivo imaging of insulin secretion from individual islets after a glucose stimulation, in live, anesthetized mice. Imaging the whole pancreas at high resolution in live mice to track the response of each individual islet over time includes numerous technical challenges and previous reports were only limited in scope and non-quantitative. Elaborating on this previous model—through the development of an improved methodology addressing anesthesia, temperature control and motion blur—we were able to track and quantify longitudinally insulin content throughout a glucose challenge in up to two hundred individual islets simultaneously. Through this approach we demonstrate quantitatively for the first time that while isolated islets respond homogeneously to glucose in culture, their profiles differ significantly in vivo. Independent of size or location, some islets respond sharply to a glucose stimulation while others barely secrete at all. This platform therefore provides a powerful approach to study the impact of disease, diet, surgery or pharmacological treatments on insulin secretion in the intact pancreas in vivo.

Recurrent pleural effusions are a major cause of morbidity and frequently lead to hospitalization. Indwelling pleural catheters (IPCs) are tunneled catheters that allow ambulatory intermittent drainage of pleural fluid without repeated thoracentesis. Despite the efficacy and safety of IPCs, data supporting postplacement follow-up is limited and variable. Our study aims to characterize the impact of a dedicated pleural clinic (PC) on patient outcomes as they relate to IPCs.Patients who underwent IPC placement between 2015 and 2021 were included in this retrospective study. Differences in outcomes were analyzed between patients with an IPC placed and managed by Interventional Pulmonology (IP) through the PC and those placed by non-IP services (non-PC providers) before and after the PC implementation.In total, 371 patients received IPCs. Since the implementation of the PC, there was an increase in ambulatory IPC placement (31/133 pre-PC vs. 96/238 post-PC; P=0.001). There were fewer admissions before IPC placement (18/103 vs. 43/133; P=0.01), and fewer thoracenteses per patient (2.7±2.5 in PC cohort vs. 4±5.1 in non-PC cohort; P0.01). The frequency of pleurodesis was higher in the PC cohort (40/103 vs. 41/268; P0.001). A Fine and Gray competing risks model indicated higher likelihood of pleurodesis in the PC cohort (adjusted subhazard ratio 3.8, 95% CI: 2.5-5.87).Our experience suggests that the implementation of a dedicated PC can lead to improved patient outcomes including fewer procedures and admissions before IPC placement, and increased rates of pleurodesis with IPC removal.

To compare the proteomic composition of follicular fluid from women with normal weight vs. women with obesity but without a history of polycystic ovary syndrome or known ovarian dysfunction undergoing in vitro fertilization.Cross-sectional.Academic medical center.Eight women with normal weight and 8 women with obesity undergoing in vitro fertilization and without a history of polycystic ovary syndrome, ovulatory dysfunction, diminished ovarian reserve, or known endometriosis were included in the analysis.Not applicable.Proteomic assessment using liquid chromatography-mass spectrometry analysis.The mean age of women with normal weight was similar to that of women with obesity (32.9 vs. 32.6 years, not significant). The mean body mass index of women with normal weight was 21.2 kg/mObesity is associated with dysregulation at the level of the follicle, including alterations in proteins related to inflammation and metabolism. These include proteins with emerging roles in energy homeostasis and follicular regulation.

Background: Fluid and vasopressor management in septic shock remains controversial. In this randomized controlled trial, we evaluated the efficacy of dynamic measures (stroke volume change during passive leg raise) to guide resuscitation and improve patient outcome. Research Question: Will resuscitation guided by dynamic assessments of fluid responsiveness in patients with septic shock improve patient outcomes? Study Design and Methods: Prospective, multicenter, randomized clinical trial at 13 hospitals in the United States and United Kingdom. Patients presented to Emergency Rooms with sepsis associated hypotension and anticipated Intensive Care Unit (ICU) admission. Intervention arm patients were assessed for fluid responsiveness before clinically driven fluid bolus or increase in vasopressors. The protocol included reassessment and therapy as indicated by the PLR result. The control arm received Usual Care. Primary clinical outcome was positive fluid balance at 72 hours or ICU discharge, whichever occurred first. Results: In modified-ITT (mITT) analysis including 83 Intervention and 41 Usual Care eligible patients, fluid balance at 72 hours or ICU discharge was significantly lower (-1.37L favoring Intervention arm, 0.65 ± 2.85L Intervention arm vs. 2.02 ± 3.44L Usual Care arm, p=0.021. Fewer patients required renal replacement therapy (5.1% vs 17.5%, p=0.04) or mechanical ventilation (17.7% vs 34.1%, p=0.04) in the Intervention arm compared to Usual Care. In the allrandomized Intent to Treat (ITT) population (102 Intervention, 48 Usual Care) there were no significant differences in safety signals. Interpretation: Physiologically informed fluid and vasopressor resuscitation using passive leg raise-induced stroke volume change to guide management of septic shock is safe and demonstrated lower net fluid balance and reductions in the risk of renal and respiratory failure. Dynamic assessments to guide fluid administration may improve outcomes for septic shock patients compared with Usual Care. Trial Registration clinicaltrials.gov identifier: NCT02837731

The opsin family of G-protein-coupled receptors are used as light detectors in animals. Opsin 5 (also known as neuropsin or OPN5) is a highly conserved opsin that is sensitive to visible violet light1,2. In mice, OPN5 is a known photoreceptor in the retina3 and skin4 but is also expressed in the hypothalamic preoptic area (POA)5. Here we describe a light-sensing pathway in which POA neurons that express Opn5 regulate thermogenesis in brown adipose tissue (BAT). We show that Opn5 is expressed in glutamatergic warm-sensing POA neurons that receive synaptic input from several thermoregulatory nuclei. We further show that Opn5 POA neurons project to BAT and decrease its activity under chemogenetic stimulation. Opn5-null mice show overactive BAT, increased body temperature, and exaggerated thermogenesis when cold-challenged. Moreover, violet photostimulation during cold exposure acutely suppresses BAT temperature in wild-type mice but not in Opn5-null mice. Direct measurements of intracellular cAMP ex vivo show that Opn5 POA neurons increase cAMP when stimulated with violet light. This analysis thus identifies a violet light-sensitive deep brain photoreceptor that normally suppresses BAT thermogenesis. Mice possess neurons in the preoptic area of the hypothalamus that are sensitive to violet light; these deep brain neurons sense light via OPN5 and regulate adaptive thermogenesis in brown fat.

Purpose Previous studies assessing impact of acute respiratory distress syndrome (ARDS) on mortality have shown conflicting results. We sought to assess the independent association of ARDS with in-hospital mortality among intensive care unit (ICU) patients with sepsis. Methods We studied two prospective sepsis cohorts drawn from the Early Assessment of Renal and Lung Injury (EARLI; n = 474) and Validating Acute Lung Injury markers for Diagnosis (VALID; n = 337) cohorts. ARDS was defined by Berlin criteria. We used logistic regression to compare in-hospital mortality in patients with and without ARDS, controlling for baseline severity of illness. We also estimated attributable mortality, adjusted for illness severity by stratification. Results ARDS occurred in 195 EARLI patients (41%) and 99 VALID patients (29%). ARDS was independently associated with risk of hospital death in multivariate analysis, even after controlling for severity of illness, as measured by APACHE II (odds ratio [OR] 1.65 (95% confidence interval [CI] 1.02, 2.67), p = 0.04 in EARLI; OR 2.12 (CI 1.16, 3.92), p = 0.02 in VALID). Patients with severe ARDS (P/F

Objective Post–bariatric surgery hypoglycemia (PBH) is defined as the presence of neuroglycopenic symptoms accompanied by postprandial hypoglycemia in bariatric surgery patients. Recent clinical studies using continuous glucose monitoring (CGM) technology revealed that PBH is more frequently observed in vertical sleeve gastrectomy (VSG) patients than previously recognized. PBH cannot be alleviated by current medication. Therefore, a model system to investigate the mechanism and treatment is required. Methods We used CGM in a rat model of VSG and monitored the occurrence of glycemic variability and hypoglycemia in various meal conditions for 4 weeks after surgery. Another cohort of VSG rats with CGM was used to investigate whether the blockade of glucagon-like peptide-1 receptor (GLP-1R) signaling alleviates these symptoms. A mouse VSG model was used to investigate whether the impaired glucose counterregulatory system causes postprandial hypoglycemia. Results Like in humans, rats have increased glycemic variability and hypoglycemia after VSG. Postprandial hypoglycemia was specifically detected after liquid versus solid meals. Further, the blockade of GLP-1R signaling raises the glucose nadir but does not affect glycemic variability. Conclusions Rat bariatric surgery duplicates many features of human post–bariatric surgery hypoglycemia including postprandial hypoglycemia and glycemic variability, while blockade of GLP-1R signaling prevents hypoglycemia but not the variability., Highlights • VSG causes glycemic variability during ad lib feeding condition. • Single liquid meal ingestion causes post-VSG hypoglycemia. • Blockade of GLP-1 receptor prevents post-VSG hypoglycemia.

Glucagon-like peptide-1 (GLP-1) is an enteral peptide that contributes to the incretin effect. GLP-1 action is typically described as endocrine, but this mechanism has been questioned because rapid inactivation in the circulation by dipeptidylpeptidase 4 (DPP4) results in a short half-life, limiting the amount of the hormone that can reach the pancreatic islet. An alternative mechanism for GLP-1 to regulate insulin secretion through neuroendocrine signaling originating from sensors in the portal vein has been proposed. We hypothesized that portal infusion of GLP-1 would cause greater glucose-stimulated insulin secretion than equimolar administration into the jugular vein. To test this, hyperglycemic clamps with superimposed graded infusions of GLP-1 into the jugular or portal veins of male rats were performed. These experiments were repeated with pharmacologic DPP4 inhibition to determine the effect of GLP-1 metabolism in the jugular and portal venous beds. Contrary to our hypothesis, we found a higher insulinotropic effect with jugular compared with portal GLP-1, which was associated with higher plasma concentrations of intact GLP-1. The greater insulinotropic effect of jugular venous GLP-1 persisted even with pharmacological DPP4 inhibition. These findings do not support an important role of portal vein GLP-1 signaling for the incretin effect but highlight the hepatoportal bed as a major site of GLP-1 degradation that persists even with pharmacological inhibition. Together, these results support rapid inactivation of enterally released GLP-1 in the liver as limiting endocrine actions on the β-cell and raise questions about the conventional endocrine model of pharmacologic effects of DPP4 inhibitors.

Bromocriptine, a dopamine D2 receptor agonist originally used for the treatment of hyperprolactinemia, is largely successful in reducing hyperglycemia and improving glucose tolerance in type 2 diabetics. However, the mechanism behind bromocriptine’s effect on glucose intolerance is unclear. Here, we tested three hypotheses, that bromocriptine may exert its effects on glucose metabolism by 1) decreasing prolactin secretion, 2) indirectly increasing activity of key melanocortin receptors in the central nervous system, or 3) improving/restoring circadian rhythms. Using a diet-induced obese (DIO) mouse model, we established that a 2-wk treatment of bromocriptine is robustly effective at improving glucose tolerance. We then demonstrated that bromocriptine is effective at improving the glucose tolerance of both DIO prolactin-deficient and melanocortin-4 receptor (MC4R)-deficient mice, pointing to bromocriptine’s ability to affect glucose tolerance independently of prolactin or MC4R signaling. Finally, we tested bromocriptine’s dependence on the circadian system by testing its effectiveness in environmental (e.g., repeated shifts to the light-dark cycle) and genetic (e.g., the Clock mutant mouse) models of circadian disruption. In both models of circadian disruption, bromocriptine was effective at improving glucose tolerance, indicating that a functional or well-aligned endogenous clock is not necessary for bromocriptine’s effects on glucose metabolism. Taken together, these results do not support the role of prolactin, MC4R, or the circadian clock as integral to bromocriptine’s underlying mechanism. Instead, we find that bromocriptine is a robust diabetic treatment and resilient to genetically induced obesity, diabetes, and circadian disruption.

Objective Vertical Sleeve Gastrectomy (VSG) is one of the most efficacious treatments for obesity and its comorbidities. Although a range of evidence suggests that alterations of the microbiota in the distal gut following VSG are pivotal to these metabolic improvements, the effect of surgery to alter the microbiota of the proximal intestine and its effect on host physiology remain largely unknown. As the main bacteria in the upper small intestine, Lactobacillus subspecies have been appreciated as important regulators of gut function. These bacteria also regulate intestinal Hypoxia- Inducible Factor 2α (HIF2α) signaling that plays an integral role in gut physiology and iron absorption. In the present study, we sought to determine the impact of VSG on Lactobacillus spp. in the small intestine and potential downstream impacts of Lactobacillus spp. on HIF2α, specifically in the duodenum. Methods To determine the effects of VSG on the microbiota and HIF2α signaling in the duodenum, VSG surgeries were performed on diet-induced obese mice. To further probe the relationship between Lactobacillus spp. and HIF2α signaling in the duodenum, we applied a customized high-fat but iron-deficient diet on mice to increase duodenal HIF2α signaling and determined alterations of gut bacteria. To explore the causal role of Lactobacillus spp. in duodenal HIF2α signaling activation, we chronically administered probiotics containing Lactobacillus spp. to high-fat-fed obese mice. Lastly, we studied the effect of lactate, the major metabolite of Lactobacilli, on HIF2α in ex vivo duodenal organoids. Results There were pronounced increases in the abundance of Lactobacillus spp. in samples isolated from duodenal epithelium in VSG-operated mice as compared to sham-operated mice. This was accompanied by an increase in the expression of genes that are targets of HIF2α in the duodenum of VSG-treated mice. Activating HIF2α signaling with a high-fat but iron-deficient diet resulted in weight loss, improvements in glucose regulation, and increased Lactobacillus spp. richness in the duodenum as compared to mice on an iron-replete diet. Chronic administration of probiotics containing Lactobacillus spp. not only increased HIF2α signaling in the duodenum such as occurs after VSG but also resulted in reduced weight gain and improved glucose tolerance in high-fat-fed mice. Furthermore, lactate was able to activate HIF2α in ex vivo duodenal organoids. Conclusions These results support a model whereby VSG increases duodenal Lactobacillus richness and potentially stimulates intestinal HIF2α signaling via increased lactate production., Graphical abstract Image 1, Highlights • Vertical sleeve gastrectomy increases Lactobacillus richness in the duodenum. • Vertical sleeve gastrectomy activates HIF2α signaling in the duodenum. • Increased Lactobacillus is linked to diet-induced HIF2α activation in the duodenum. • Probiotics containing Lactobacillus spp. activate HIF2α signaling in the duodenum. • Lactate can directly activate HIF2α signaling in the intestinal cells.

SUMMARYMetformin is a blood glucose lowering medication with physiological effects that extend beyond its anti-diabetic indication. Recently, it was reported that metformin lowers body weight via induction of growth differentiation factor 15 (GDF15), which suppresses food intake by binding to the GDNF family receptor α-like (GFRAL) in the hindbrain. At the same time, we demonstrated that recombinant GDF15 suppresses voluntary exercise in a GFRAL-dependent fashion. Here, we corroborate that metformin increases circulating GDF15 in mice and humans, but that it does not reduce voluntary running activity in mice. Unexpectedly, we fail to confirm previous reports that the GDF15-GFRAL pathway is necessary for the weight-lowering effects of metformin. Instead, our studies in wild-type, GDF15 knockout and GFRAL knockout mice suggest that the GDF15-GFRAL pathway is dispensable for the effects of metformin on energy balance. The data presented here question whether metformin is a sufficiently strong stimulator of GDF15 to drive anorexia and weight loss and emphasize that additional work is needed to untangle the relationship among metformin, GDF15 and energy balance.

GNPDA2 has been associated with human obesity and type-2 diabetes by using a GWAS approach. GNPDA2 is an enzyme involved in the hexosamine biosynthesis pathway, which is known to be important for nutrient sensing in various organism. Its counter enzyme, GFAT, has previously been shown to be important to the development of insulin resistance in diabetes. The implication of GNPDA2 and GFAT in metabolism is scarce and the effect of both enzymes over appetite and glucose homeostasis is unknown.Aim: Identify the role of GNPDA2 and GFAT in nutrient sensing circuits of the CNS that are important for the regulation of both appetite and glucose homeostasis.Methods: Using Long Evans rats, we administered either a GNPDA2 or GFAT antagonist or vehicle in i3vt.Key Findings:GNPDA2 is highly expressed in hypothalamus and adipose tissue, followed by muscle and liver. GNPDA2 is expressed in different hypothalamic nuclei (ARC, DMH, LHA, PVN). GNPDA2 is downregulated in hypothalamus under diet-induced obesity (as previously described), but GFAT expression does not change. Moreover, i3vt infusion of GNPDA2 or GFAT inhibitor resulted in increased c-Fos in areas related to appetite and glucose homeostasis control as PVN and DMH and to a lesser extent in the LHA and ARC. Central inhibition of GNPDA2 does not alter either acute food intake or body weight; however, GFAT inhibition diminished appetite and body weight due to visceral illness. In addition, central administration of the GNPDA2 antagonist, prior to an intraperitoneal glucose tolerance test, resulted in glucose intolerance in comparison to vehicle without altering insulin levels.Significance: These results suggest that central GNPDA2 does not control appetite, but regulates glucose homeostasis.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used to treat diabetes and obesity and reduce rates of major cardiovascular events, such as stroke and myocardial infarction. Nevertheless, the identity of GLP-1R–expressing cell types mediating the cardiovascular benefits of GLP-1RA remains incompletely characterized. Herein, we investigated the importance of murine Glp1r expression within endothelial and hematopoietic cells. Mice with targeted inactivation of Glp1r in Tie2+ cells exhibited reduced levels of Glp1r mRNA transcripts in aorta, liver, spleen, blood, and gut. Glp1r expression in bone marrow cells was very low and not further reduced in Glp1rTie2–/– mice. The GLP-1RA semaglutide reduced the development of atherosclerosis induced by viral PCSK9 expression in both Glp1rTie2+/+ and Glp1rTie2–/– mice. Hepatic Glp1r mRNA transcripts were reduced in Glp1rTie2–/– mice, and liver Glp1r expression was localized to γδ T cells. Moreover, semaglutide reduced hepatic Tnf, Abcg1, Tgfb1, Cd3g, Ccl2, and Il2 expression; triglyceride content; and collagen accumulation in high-fat, high-cholesterol diet–fed Glp1rTie2+/+ mice but not Glp1rTie2–/– mice. Collectively, these findings demonstrate that Tie2+ endothelial or hematopoietic cell GLP-1Rs are dispensable for the antiatherogenic actions of GLP-1RA, whereas Tie2-targeted GLP-1R+ cells are required for a subset of the antiinflammatory actions of semaglutide in the liver.

Standfirst: Some “species differences” between mouse and human can be diminished simply by housing mice at warmer temperatures. Failure to strategically turn up the thermostat may undermine translation of findings in mice into insights on human metabolic diseases.

Changing composition of the gut microbiome is an important component of the gut adaptation to various environments, which have been implicated in various metabolic diseases including obesity and type 2 diabetes, but the mechanisms by which the microbiota influence host physiology remain contentious. Here we find that both diets high in the fermentable fiber inulin and vertical sleeve gastrectomy increase intestinal expression and circulating levels of the anti-microbial peptide Reg3g. Moreover, a number of beneficial effects of these manipulations on gut function, energy balance, and glucose regulation are absent in Reg3g knockout mice. Peripheral administration of various preparations of Reg3g improves glucose tolerance, and this effect is dependent on the putative receptor Extl3 in the pancreas. These data suggest Reg3g acts both within the lumen and as a gut hormone to link the intestinal microbiome to various aspects of host physiology that may be leveraged for novel treatment strategies.

Gut intraepithelial lymphocytes (IELs) are thought to calibrate glucagon-like peptide 1 (GLP-1) bioavailability, thereby regulating systemic glucose and lipid metabolism. Here, we show that the gut IEL GLP-1 receptor (GLP-1R) is not required for enteroendocrine L cell GLP-1 secretion and glucose homeostasis nor for the metabolic benefits of GLP-1R agonists (GLP-1RAs). Instead, the gut IEL GLP-1R is essential for the full effects of GLP-1RAs on gut microbiota. Moreover, independent of glucose control or weight loss, the anti-inflammatory actions of GLP-1RAs require the gut IEL GLP-1R to selectively restrain local and systemic T cell-induced, but not lipopolysaccharide-induced, inflammation. Such effects are mediated by the suppression of gut IEL effector functions linked to the dampening of proximal T cell receptor signaling in a protein-kinase-A-dependent manner. These data reposition key roles of the L cell-gut IEL GLP-1R axis, revealing mechanisms linking GLP-1R activation in gut IELs to modulation of microbiota composition and control of intestinal and systemic inflammation.