Distribution Analysis of Deacetylase SIRT1 in Rodent and Human Nervous Systems

Abstract

Sirtuins function with other biogenic molecules to promote adaptation to caloric restriction in a broad spectrum of eukaryotic species. Sirtuin pathways also converge in the mammalian brain where they appear to protect neurons from nutrient stress. However, few anatomical studies on sirtuins (e.g., SIRT1) are available, particularly those detailing the spatial distribution and subcellular localization pattern of SIRT1 in the brain parenchyma. Here, we report the characterization of a panel of SIRT1-specific antibodies within rodent (i.e., rat and mouse) and human central nervous systems. Immunocytochemical and Western blot analyses indicate that the subcellular localization of SIRT1 is predominantly nuclear throughout the rodent brain and spinal cord. A similar subcellular distribution pattern of SIRT1 was detected in human central nervous system material. SIRT1 is ubiquitously present in areas of the brain especially susceptible to age-related neurodegenerative states (e.g., the prefrontal cortex, hippocampus and basal ganglia). Further, we show no apparent species-specific differences in the subcellular localization pattern of rodent versus human SIRT1. Finally, we identify the chemical phenotype of SIRT1-containing neurons in a number of brain sites that are strongly compromised by aging. These data provide additional and important anatomical findings for the role of SIRT1 in the mammalian brain and suggest that SIRT1 pathways are broadly distributed in neurons most susceptible to senescence injury. Activating endogenous sirtuin pathways may, therefore, offer a therapeutic approach to delay and/or treat human agerelated diseases. Anat Rec, 293:1024Rec, 293: -1032Rec, 293: , 2010. V V C 2010 Wiley-Liss, Inc.Key words: basal ganglia; hippocampus; parvalbumin; prefrontal cortex; tyrosine hydroxylaseSirtuins are histone nicotinamide adenosine dinucleotide (NAD)-dependent deacetylases widely recognized for their link to eukaryotic life span (Guarente and Picard, 2005;Michan and Sinclair, 2007). Silent information regulator 1 (SIRT1), the most studied among the seven mammalian sirtuins, increases when situations favor longevity, such as caloric restriction or following treatment with the polyphenol resveratrol. SIRT1 resides primarily in the cell nucleus where it targets several nonhistone transcriptional regulators including p53, heat shock factor 1 (HSF1), forkhead transcription factor (FOXO), NF-jB, and peroxisome proliferator-activator receptor-c coactivator-1a (PGC-1a). These factors promote adaptation to caloric restriction by regulating agerelated programs of replicative senescence, protein homeostasis, inflammatory function, and energy metabolism (Vaziri et al., 2001;Motta et al., 2004;Yeung et al.,

Molecular Imaging of Sirtuin1 Expression–Activity in Rat Brain Using Positron-Emission Tomography–Magnetic-Resonance Imaging with [18F]-2-Fluorobenzoylaminohexanoicanilide

“…High levels of 2-[ 18 F]BzAHA-derived radioactivity and SIRT1 immunofluorescence observed in the hippocampus (Figures 3, S8−S10, and S14) are consistent with previous studies using ISH, 38a IHC, 38b and IF. 39 SIRT1 is involved in mechanisms of learning and memory (both short- and long-term); it modulates synaptic plasticity through transcriptional regulation of a brain-derived neurotrophic factor via MeCP2 deacetylation.…”

Viral genome silencing by neuronal sirtuin 1

“…In contrast, there is no visible nuclear Sirt1 staining within the satellite cells of the DRG although a few cells exhibited cytoplasmic staining. In the central nervous system, neuronal Sirt1 expression and distribution were shown to be equivalent in adult rats and humans (Zakhary et al 2010). Our results provide the first evidence of Sirt1 expression in adult DRG neurons and contrast with previous reports of expression only occurring during embryogenesis (Sakamoto et al 2004b).…”

Reduced expression of SIRT1 and SOD-1 and the correlation between these levels in various regions of the brains of patients with Alzheimer's disease

“…SIRT1 is localised predominantly in the cytoplasm and nuclei of cells throughout the rodent brain and spinal cord, as well as the human central nervous system 26. Another study detected high levels of SIRT1 in the cortex and hippocampus, and low levels in the white matter of rat brains 27.…”