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Cholinergic regulation of bone. Eimar H,Tamimi I,Murshed M,Tamimi F Journal of musculoskeletal & neuronal interactions Bone remodeling is regulated by the two branches of the autonomic nervous system: the adrenergic and the cholinergic branches. Adrenergic activity favors bone loss, whereas cholinergic activity has been recently shown to favor bone mass accrual. In vitro studies have reported that cholinergic activity induces proliferation and differentiation of bone cells. In vivo studies have shown that the inhibition of cholinergic activity favors bone loss, whereas its stimulation favors bone mass accrual. Clinical studies have shown that bone density is associated with the function of many cholinergic-regulated tissues such as the hypothalamus, salivary glands, lacrimal glands and langerhans cells, suggesting a common mechanism of control. Altogether, these observations and linked findings are of great significance since they improve our understanding of bone physiology. These discoveries have been successfully used recently to investigate new promising therapies for bone diseases based on cholinergic stimulation. Here, we review the current understanding of the cholinergic activity and its association with bone health.
Pituitary-bone connection in skeletal regulation. Zaidi Mone,Sun Li,Liu Peng,Davies Terry F,New Maria,Zallone Alberta,Yuen Tony Hormone molecular biology and clinical investigation Pituitary hormones have traditionally been thought to exert specific, but limited function on target tissues. More recently, the discovery of these hormones and their receptors in organs such as the skeleton suggests that pituitary hormones have more ubiquitous functions. Here, we discuss the interaction of growth hormone (GH), follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin and arginine vasopressin (AVP) with bone. The direct skeletal action of pituitary hormones therefore provides new insights and therapeutic opportunities for metabolic bone diseases, prominently osteoporosis. 10.1515/hmbci-2016-0015
Hypothalamic sensing of fatty acids. Lam Tony K T,Schwartz Gary J,Rossetti Luciano Nature neuroscience Selective regions of the brain, including the hypothalamus, are capable of gathering information on the body's nutritional status in order to implement appropriate behavioral and metabolic responses to changes in fuel availability. This review focuses on direct metabolic signaling within the hypothalamus. There is growing evidence supporting the idea that fatty acid metabolism within discrete hypothalamic regions can function as a sensor for nutrient availability that can integrate multiple nutritional and hormonal signals. 10.1038/nn1456
Brain lipid sensing and the neural control of energy balance. Magnan Christophe,Levin Barry E,Luquet Serge Molecular and cellular endocrinology Fatty acid (FA) -sensitive neurons are present in the brain, especially the hypothalamus, and play a key role in the neural control of energy and glucose homeostasis including feeding behavior, secretion insulin and action. Subpopulations of neurons in the arcuate and ventromedial hypothalamic nuclei are selectively either activated or inhibited by FA. Molecular effectors of these FA effects include ion channels such as chloride, potassium or calcium. In addition, at least half of the responses in the hypothalamic ventromedial FA neurons are mediated through interaction with the FA translocator/receptor, FAT/CD36, that does not require metabolism to activate intracellular signaling downstream. Recently, an important role of lipoprotein lipase in FA detection has also been demonstrated not only in the hypothalamus, but also in the hippocampus and striatum. Finally, FA could overload energy homeostasis via increased hypothalamic ceramide synthesis which could, in turn, contribute to the pathogenesis of diabetes of obesity and/or type 2 in predisposed individuals by disrupting the endocrine signaling pathways of insulin and/or leptin. 10.1016/j.mce.2015.09.019
Development and Function of the Blood-Brain Barrier in the Context of Metabolic Control. Haddad-Tóvolli Roberta,Dragano Nathalia R V,Ramalho Albina F S,Velloso Licio A Frontiers in neuroscience Under physiological conditions, the brain consumes over 20% of the whole body energy supply. The blood-brain barrier (BBB) allows dynamic interactions between blood capillaries and the neuronal network in order to provide an adequate control of molecules that are transported in and out of the brain. Alterations in the BBB structure and function affecting brain accessibility to nutrients and exit of toxins are found in a number of diseases, which in turn may disturb brain function and nutrient signaling. In this review we explore the major advances obtained in the understanding of the BBB development and how its structure impacts on function. Furthermore, we focus on the particularities of the barrier permeability in the hypothalamus, its role in metabolic control and the potential impact of hypothalamic BBB abnormities in metabolic related diseases. 10.3389/fnins.2017.00224