The preoptic area (POA) regulates body temperature, but is not considered a site for body weight control. A subpopulation of POA neurons express leptin receptors (LepRb POA neurons) and modulate reproductive function. However, LepRb POA neurons project to sympathetic premotor neurons that control brown adipose tissue (BAT) thermogenesis, suggesting an additional role in energy homeostasis and body weight regulation. We determined the role of LepRb POA neurons in energy homeostasis using cre-dependent viral vectors to selectively activate these neurons and analyzed functional outcomes in mice. We show that LepRb POA neurons mediate homeostatic adaptations to ambient temperature changes, and their pharmacogenetic activation drives robust suppression of energy expenditure and food intake, which lowers body temperature and body weight. Surprisingly, our data show that hypothermia-inducing LepRb POA neurons are glutamatergic, while GABAergic POA neurons, originally thought to mediate warm-induced inhibition of sympathetic premotor neurons, have no effect on energy expenditure. Our data suggest a new view into the neurochemical and functional properties of BAT-related POA circuits and highlight their additional role in modulating food intake and body weight.

ObjectiveLeptin responsive neurons play an important role in energy homeostasis, controlling specific autonomic, behavioral, and neuroendocrine functions. We have previously identified a population of leptin receptor (LepRb) expressing neurons within the dorsomedial hypothalamus/dorsal hypothalamic area (DMH/DHA) which are related to neuronal circuits that control brown adipose tissue (BAT) thermogenesis. Intra-DMH leptin injections also activate sympathetic outflow to BAT, but whether such effects are mediated directly via DMH/DHA LepRb neurons and whether this is physiologically relevant for whole body energy expenditure and body weight regulation has yet to be determined.MethodsWe used pharmacosynthetic receptors (DREADDs) to selectively activate DMH/DHA LepRb neurons. We further deleted LepRb with virally driven cre-recombinase from DMH/DHA neurons and determined the physiological importance of DMH/DHA LepRb neurons in whole body energy homeostasis.ResultsNeuronal activation of DMH/DHA LepRb neurons with DREADDs promoted BAT thermogenesis and locomotor activity, which robustly induced energy expenditure (p < 0.001) and decreases body weight (p < 0.001). Similarly, intra-DMH/DHA leptin injections normalized hypothermia and attenuated body weight gain in leptin-deficient ob/ob mice. Conversely, ablation of LepRb from DMH/DHA neurons remarkably drives weight gain (p < 0.001) by reducing energy expenditure (p < 0.001) and locomotor activity (p < 0.001). The observed changes in body weight were largely independent of food intake.ConclusionTaken together, our data highlight that DMH/DHA LepRb neurons are sufficient and necessary to regulate energy expenditure and body weight.

Porcine arterial endothelial cells (PAECs)Pulmonary arterial endothelial cells were obtained from freshly slaughtered pigs by exposure of the excised pulmonary artery to 0.1 % collagenase for 12-15 min. Cells were cultured in medium 199 containing 10 % fetal calf serum (GIBCO, Karlsruhe, Germany), passaged and characterized as described by Suttorp et al. (1988). Only cultures of passages 2-5 were used.Cell culture studies Cells were grown on coverslips, coated with gelatin cross-linked with glutaraldehyde (Schnittler et al. 1993). Toxin B was added to R. H. Adamson and others 296

Oxidative stress and vascular inflammatory response are key mediators of endothelial dysfunction that leads to cardiovascular diseases. A novel peptide, IRW, was previously characterized from egg protein with angiotensin converting enzyme inhibitory activity. The purpose of the study was to investigate the effects and molecular mechanisms of IRW on regulating inflammatory response in endothelial cells. The results showed that tumor necrosis factor-α (TNF-α) significantly increased the protein levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1), whereas pretreatment with IRW inhibited TNF-α-induced increases of ICAM-1, VCAM-1, and MCP-1 production in a concentration-dependent manner. IRW also reduced the levels of superoxide ions in the presence and absence of TNF-α. These results indicate the potential role of IRW in preventing cardiovascular disease as a functional food ingredient or nutraceutical.