We identified a gene in the ovine hypothalamus encoding for RFamide-related peptide-3 (RFRP-3), and tested the hypothesis that this system produces a hypophysiotropic hormone that inhibits the function of pituitary gonadotropes. The RFRP-3 gene encodes for a peptide that appears identical to human RFRP-3 homolog. Using an antiserum raised against RFRP-3, cells were localized to the dorsomedial hypothalamic nucleus/paraventricular nucleus of the ovine brain and shown to project to the neurosecretory zone of the ovine median eminence, predicating a role for this peptide in the regulation of anterior pituitary gland function. Ovine RFRP-3 peptide was tested for biological activity in vitro and in vivo, and was shown to reduce LH and FSH secretion in a specific manner. RFRP-3 potently inhibited GnRH-stimulated mobilization of intracellular calcium in gonadotropes. These data indicate that RFRP-3 is a specific and potent mammalian gonadotropin-inhibiting hormone, and that it acts upon pituitary gonadotropes to reduce GnRH-stimulated gonadotropin secretion.
Background-We hypothesized that molecular imaging of endothelial cell adhesion molecule expression could noninvasively evaluate prelesion atherogenic phenotype. Methods and Results-Mice deficient for the LDL-receptor and the Apobec-1 editing peptide (DKO mice) were studied as an age-dependent model of atherosclerosis. At 10, 20, and 40 weeks of age, ultrasound molecular imaging of the proximal thoracic aorta was performed with contrast agents targeted to P-selectin and VCAM-1. Atherosclerotic lesion severity and content were assessed by ultrahigh frequency ultrasound, histology, and immunohistochemistry. In wild-type mice at all ages, there was neither aortic thickening nor targeted tracer signal enhancement. In DKO mice, lesions progressed from sparse mild intimal thickening at 10 weeks to widespread severe lesions with luminal encroachment at 40 weeks. Molecular imaging for P-selectin and VCAM-1 demonstrated selective signal enhancement (PϽ0.01 versus nontargeted agent) at all ages for DKO mice. P-selectin and VCAM-1 signal in DKO mice were greater by 3-fold at 10 weeks, 4-to 6-fold at 20 weeks, and 9-to 10-fold at 40 weeks compared to wild-type mice. En face microscopy demonstrated preferential attachment of targeted microbubbles to regions of lesion formation.
Conclusions-Noninvasive
Prader-Willi syndrome (PWS) is the predominant genetic cause of obesity in humans. Recent clinical reports have suggested that micro-deletion of the Snord116 gene cluster can lead to PWS, however, the extent of the contributions of the encoded snoRNAs is unknown. Here we show that mice lacking Snord116 globally have low birth weight, increased body weight gain, energy expenditure and hyperphagia. Consistent with this, microarray analysis of hypothalamic gene expression revealed a significant alteration in feeding related pathways that was also confirmed by in situ hybridisation. Importantly, selective deletion of Snord116 only from NPY expressing neurons mimics almost exactly the global deletion phenotype including the persistent low birth weight, increased body weight gain in early adulthood, increased energy expenditure and hyperphagia. Mechanistically, the lack of Snord116 in NPY neurons leads to the upregulation of NPY mRNA consistent with the hyperphagic phenotype and suggests a critical role of Snord116 in the control of NPY neuronal functions that might be dysregulated in PWS.
ObjectivesInsulin signaling in the brain has been implicated in the control of satiety, glucose homeostasis and energy balance. However, insulin signaling is dispensable in energy homeostasis controlling AgRP or POMC neurons and it is unclear which other neurons regulate these effects. Here we describe an ancient insulin/NPY neuronal network that governs energy homeostasis across phyla.MethodsTo address the role of insulin action specifically in NPY neurons, we generated a variety of models by selectively removing insulin signaling in NPY neurons in flies and mice and testing the consequences on energy homeostasis.ResultsBy specifically targeting the insulin receptor in both fly and mouse NPY expressing neurons, we found NPY-specific insulin signaling controls food intake and energy expenditure, and lack of insulin signaling in NPY neurons leads to increased energy stores and an obese phenotype. Additionally, the lack of insulin signaling in NPY neurons leads to a dysregulation of GH/IGF-1 axis and to altered insulin sensitivity.ConclusionsTaken together, these results suggest that insulin actions in NPY neurons is critical for maintaining energy balance and an impairment of this pathway may be causally linked to the development of metabolic diseases.
Highlights d Central amygdala NPY neurons control feeding d Stress combined with a high-caloric diet increases NPY expression in the central amygdala d Insulin controls NPY expression in central amygdala neurons d Stress combined with a high-caloric diet causes insulin resistance in central amygdala
The effect of 2017 American College of Cardiology/American Heart Association stage 1 hypertension on cardiovascular risk is evidenced in young and middle-aged Chinese adults, but not in those age ≥60 years.
An important strategy in primary prevention of cardiovascular diseases (CVD) is the early identification of high-risk individuals. Effective implementation of a strategy to identify these individuals in a clinical setting is reliant on the availability of appropriate CVD risk-assessment models and guideline recommendations. Several well-known models for CVD risk assessment have been developed and utilized in the USA and Europe, but might not be suitable for use in other regions or countries. Very few reports have discussed the development of risk-assessment models and recommendations from a global perspective. In this Review, we discuss why risk-assessment methods developed from studies in one geographical region or ethnic population might not be suitable for other regions or populations, and examine the availability and characteristics of predictive models in areas beyond the USA or Europe. In addition, we compare the differences in risk-assessment recommendations outlined in CVD clinical guidelines from developed and developing countries, and consider their potential effect on clinical practice. This overview of cardiovascular risk assessment from a global perspective can potentially guide low-to-middle-income countries in the development or validation of their own CVD risk-assessment models, and the formulation of recommendations in their own clinical guidelines according to local requirements.
Taken together, we demonstrated three two-locus pairs of polymorphisms with synergistic effect out of three genes in RAAS and found significant haplotype-phenotype interaction. Functional studies to confirm or refute these findings are warranted.
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