Rockefeller University

About: Rockefeller University is a education organization based out in New York, New York, United States. It is known for research contribution in the topics: Population & Gene. The organization has 15867 authors who have published 32938 publications receiving 2940261 citations. The organization is also known as: Rockefeller University & Rockefeller Institute.

Sleep deprivation as a neurobiologic and physiologic stressor: Allostasis and allostatic load.

Abstract: Sleep has important homeostatic functions, and sleep deprivation is a stressor that has consequences for the brain, as well as many body systems. Whether sleep deprivation is due to anxiety, depression, or a hectic lifestyle, there are consequences of chronic sleep deprivation that impair brain functions and contribute to allostatic load throughout the body. Allostatic load refers to the cumulative wear and tear on body systems caused by too much stress and/or inefficient management of the systems that promote adaptation through allostasis. Chronic sleep deprivation in young healthy volunteers has been reported to increase appetite and energy expenditure, increase levels of proinflammatory cytokines, decrease parasympathetic and increase sympathetic tone, increase blood pressure, increase evening cortisol levels, as well as elevate insulin and blood glucose. Repeated stress in animal models causes brain regions involved in memory and emotions, such as hippocampus, amygdala, and prefrontal cortex, to undergo structural remodeling with the result that memory is impaired and anxiety and aggression are increased. Structural and functional magnetic resonance imaging studies in depression and Cushing's disease, as well as anxiety disorders, provide evidence that the human brain may be similarly affected. Moreover, brain regions such as the hippocampus are sensitive to glucose and insulin, and both type 1 and type 2 diabetes mellitus are associated with cognitive impairment and (for type 2 diabetes mellitus) increased risk for Alzheimer's disease. Animal models of chronic sleep deprivation indicate that memory is impaired along with depletion of glycogen stores and increases in oxidative stress and free radical production. Taken together, these changes in brain and body are further evidence that sleep deprivation is a chronic stressor and that the resulting allostatic load can contribute to cognitive problems, which can, in turn, further exacerbate pathways that lead to disease.

Synapsins as mediators of BDNF- enhanced neurotransmitter release

Abstract: We examined enhancement of synaptic transmission by neurotrophins at the presynaptic level. In a synaptosomal preparation, brain-derived neurotrophic factor (BDNF) increased mitogen-activated protein (MAP) kinase-dependent synapsin I phosphorylation and acutely facilitated evoked glutamate release. PD98059, used to inhibit MAP kinase activity, markedly decreased synapsin I phosphorylation and concomitantly reduced neurotransmitter release. The stimulation of glutamate release by BDNF was strongly attenuated in mice lacking synapsin I and/or synapsin II. These results indicate a causal link of synapsin phosphorylation via BDNF, TrkB receptors and MAP kinase with downstream facilitation of neurotransmitter release.

Dendritic Cells: Features and Functions

Abstract: Dendritic cells (DC) are irregularly shaped cells that were initially identified in the glass and plastic adherent population of mouse spleen. DC are la*, Ig", thy-1" bone marrow derived elements that show little or no endocytic activity for several tracers. DC occur in low frequency accounting for less than 1 *% of the cells in all organs we have studied. However, methods have been developed for their enrichment. DC in small numbers stimulate allogeneic and syngeneic mixed leukocyte reactions (MLR) and serve as accessory cells for the development of in viiro immune responses. This review will consider several topics: a) the principal features of DC that are useful in their identification, purification, and differentiation from mononuclear phagocytes the other cell type most often considered in studies of accessory cell functions; b) surface markers of DC including expression of la antigens; c) properties of DC in situ; and d) functional capacities of DC in vitro.

Intravenous gammaglobulin suppresses inflammation through a novel T H 2 pathway

Abstract: High-dose intravenous immunoglobulin is a widely used therapeutic preparation of highly purified immunoglobulin G (IgG) antibodies. It is administered at high doses (1-2 grams per kilogram) for the suppression of autoantibody-triggered inflammation in a variety of clinical settings. This anti-inflammatory activity of intravenous immunoglobulin is triggered by a minor population of IgG crystallizable fragments (Fcs), with glycans terminating in α2,6 sialic acids (sFc) that target myeloid regulatory cells expressing the lectin dendritic-cell-specific ICAM-3 grabbing non-integrin (DC-SIGN; also known as CD209). Here, to characterize this response in detail, we generated humanized DC-SIGN mice (hDC-SIGN), and demonstrate that the anti-inflammatory activity of intravenous immunoglobulin can be recapitulated by the transfer of bone-marrow-derived sFc-treated hDC-SIGN(+) macrophages or dendritic cells into naive recipients. Furthermore, sFc administration results in the production of IL-33, which, in turn, induces expansion of IL-4-producing basophils that promote increased expression of the inhibitory Fc receptor FcγRIIB on effector macrophages. Systemic administration of the T(H)2 cytokines IL-33 or IL-4 upregulates FcγRIIB on macrophages, and suppresses serum-induced arthritis. Consistent with these results, transfer of IL-33-treated basophils suppressed induced arthritic inflammation. This novel DC-SIGN-T(H)2 pathway initiated by an endogenous ligand, sFc, provides an intrinsic mechanism for maintaining immune homeostasis that could be manipulated to provide therapeutic benefit in autoimmune diseases.

Hypertriglyceridemia as a result of human apo CIII gene expression in transgenic mice.

Abstract: Primary and secondary hypertriglyceridemia is common in the general population, but the biochemical basis for this disease is largely unknown. With the use of transgenic technology, two lines of mice were created that express the human apolipoprotein CIII gene. One of these mouse lines with 100 copies of the gene was found to express large amounts of the protein and to be severely hypertriglyceridemic. The other mouse line with one to two copies of the gene expressed low amounts of the protein, but nevertheless manifested mild hypertriglyceridemia. Thus, overexpression of apolipoprotein CIII can be a primary cause of hypertriglyceridemia in vivo and may provide one possible etiology for this common disorder in humans.