Protein lysine acetylation has emerged as a key posttranslational modification in cellular regulation, in particular through the modification of histones and nuclear transcription regulators. We show that lysine acetylation is a prevalent modification in enzymes that catalyze intermediate metabolism. Virtually every enzyme in glycolysis, gluconeogenesis, the tricarboxylic acid (TCA) cycle, the urea cycle, fatty acid metabolism, and glycogen metabolism was found to be acetylated in human liver tissue. The concentration of metabolic fuels, such as glucose, amino acids, and fatty acids, influenced the acetylation status of metabolic enzymes. Acetylation activated enoyl–coenzyme A hydratase/3-hydroxyacyl–coenzyme A dehydrogenase in fatty acid oxidation and malate dehydrogenase in the TCA cycle, inhibited argininosuccinate lyase in the urea cycle, and destabilized phosphoenolpyruvate carboxykinase in gluconeogenesis. Our study reveals that acetylation plays a major role in metabolic regulation.

The Brain and Body Donation Program (BBDP) at Banner Sun Health Research Institute (http://www.brainandbodydonationprogram.org) started in 1987 with brain-only donations and currently has banked more than 1600 brains. More than 430 whole-body donations have been received since this service was commenced in 2005. The collective academic output of the BBDP is now described as the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND). Most BBDP subjects are enrolled as cognitively normal volunteers residing in the retirement communities of metropolitan Phoenix, Arizona. Specific recruitment efforts are also directed at subjects with Alzheimer’s disease, Parkinson’s disease and cancer. The median age at death is 82. Subjects receive standardized general medical, neurological, neuropsychological and movement disorders assessments during life and more than 90% receive full pathological examinations by medically licensed pathologists after death. The Program has been funded through a combination of internal, federal and state of Arizona grants as well as user fees and pharmaceutical industry collaborations. Subsets of the Program are utilized by the US National Institute on Aging Arizona Alzheimer’s Disease Core Center and the US National Institute of Neurological Disorders and Stroke National Brain and Tissue Resource for Parkinson’s Disease and Related Disorders. Substantial funding has also been received from the Michael J. Fox Foundation for Parkinson’s Research. The Program has made rapid autopsy a priority, with a 3.0-hour median postmortem interval for the entire collection. The median RNA Integrity Number (RIN) for frozen brain and body tissue is 8.9 and 7.4, respectively. More than 2500 tissue requests have been served and currently about 200 are served annually. These requests have been made by more than 400 investigators located in 32 US states and 15 countries. Tissue from the BBDP has contributed to more than 350 publications and more than 200 grant-funded projects.

Objective Age-related cognitive decline trajectories were compared in apolipoprotein E (APOE) e4 homozygotes (HMZ), heterozygotes (HTZ), and noncarriers (NC) in the absence of mild cognitive impairment (MCI) and Alzheimer’s dementia (AD). Background At how young an age memory decline diverges from that of noncarriers in healthy people with elevated genetic risk for late-onset AD due to APOE e4 is unknown. Methods Cognitively normal participants age 21-97 years were recruited with local ads, grouped using an APOE e4 enrichment paradigm, and had longitudinal neuropsychological testing. Anyone who developed MCI or dementia during followup was excluded. Acceleration of the rates of decline for predetermined cognitive measures were compared between APOE e4/4 HMZ, e3/4 HTZ, and e4 NC using a mixed model for longitudinal change with age. Results 79 e4 HMZ, 238 HTZ and 498 NC were included. APOE e4 carriers were younger (mean 58.0 vs 61.4 years, p<0.001) and had more years of followup (5.3 v 4.7 years, p=0.01), with equivalent education (15.4 years) and gender (69% women). With accelerating declines beginning prior to age 60 in e4 carriers, longitudinal decline in memory in e4 carriers accelerated more than in NC (p=0.0253) with a possible e4 gene-dose effect (p=0.0231) in which longitudinal decline in e4 HMZ accelerated more than in NC (p=0.0087). Weaker similar effects were also found on a visuospatial and general mental status measure. Conclusions Age-related memory decline in APOE e4 carriers diverges from NC prior to age 60 and appears most severe in HMZ despite ongoing normal clinical status.

Introduction There are dozens of drugs in development for AD with billions of dollars invested. Despite the massive investment in AD drugs and a burgeoning pipeline, there have been more setbacks and failures than treatment successes. Areas Covered The classes of drugs that have failed to date include the monoclonal antibodies, the gamma secretase inhibitors, dimebon, neurochemical enhances and one tau drug. Data for these compounds was sought through pubmed search and clinicaltrials.gov search. Expert opinion The obvious question to be posed is: Why are they failing? Is the treatment of symptomatic dementia too late? Are the therapeutic targets incorrect? Are the clinical methodologies imprecise, misleading or inaccurate? This review summarizes the drugs that have failed 2010–2015 and offers possible theories as to why they have failed.

In vivo imaging of brain β-amyloid, a hallmark of Alzheimer disease, may assist in the clinical assessment of suspected Alzheimer disease. OBJECTIVE To determine the sensitivity and specificity of positron emission tomography imaging with flutemetamol injection labeled with radioactive fluorine 18 to detect β-amyloid in the brain using neuropathologically determined neuritic plaque levels as the standard of truth. DESIGN, SETTING, AND PARTICIPANTS Open-label multicenter imaging study that took place at dementia clinics, memory centers, and hospice centers in the United States and England from June 22, 2010, to November 23, 2011. Participants included terminally ill patients who were 55 years or older with a life expectancy of less than 1 year. INTERVENTIONS Flutemetamol injection labeled with radioactive fluorine 18 (Vizamyl; GE Healthcare) administration followed by positron emission tomography imaging and subsequent brain donation. MAIN OUTCOMES AND MEASURES Sensitivity and specificity of flutemetamol injection labeled with radioactive fluorine 18 positron emission tomography imaging for brain β-amyloid. Images were reviewed without and with computed tomography scans and classified as positive or negative for β-amyloid by 5 readers who were blind to patient information. In patients who died, neuropathologically determined neuritic plaque levels were used to confirm scan interpretations and determine sensitivity and specificity. RESULTS Of 176 patients with evaluable images, 68 patients (38%) died during the study, were autopsied, and had neuritic plaque levels determined; 25 brains (37%) were β-amyloid negative; and 43 brains (63%) were β-amyloid positive. Imaging was performed a mean of 3.5 months (range, 0 to 13 months) before death. Sensitivity without computed tomography was 81% to 93% (median, 88%). Median specificity was 88%, with 4 of 5 of the readers having specificity greater than 80%. When scans were interpreted with computed tomography images, sensitivity and specificity improved for most readers but the differences were not significant. The area under the receiver operating curve was 0.90. There were no clinically meaningful findings in safety parameters. CONCLUSIONS AND RELEVANCE This study showed that flutemetamol injection labeled with radioactive fluorine 18 was safe and had high sensitivity and specificity in an end-of-life population. In vivo detection of brain β-amyloid plaque density may increase diagnostic accuracy in cognitively impaired patients.

Background and Purpose-17␤-Estradiol (E2) has been reported to exert neuroprotective effects when administered before an ischemic insult. This study was designed to determine whether E2 treatment after ischemia exerts the same effects and, if so, how long this therapeutic window remains open, and whether the effects are related to changes in cerebral blood flow (CBF). Methods-Female Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). In protocol 1, E2 was administered (100 g/kg IV followed immediately by subcutaneous implantation of crystalline E2 in a silicone elastomer tube) to ovariectomized females (OVXϩE2) at 0.5 (nϭ8), 1 (nϭ6), 2 (nϭ7), 3 (nϭ6), or 4 (nϭ9) hours after MCAO. Intact (INT; nϭ6) and ovariectomized females (OVX; nϭ12) were subjected to MCAO and received vehicle instead of E2. Two days after MCAO the animals were killed, and ischemic lesion volume was determined by 2,3,5-triphenyltetrazolium chloride staining. In protocol 2, CBF was monitored before and at 1, 24, and 48 hours in a group of animals receiving E2 or vehicle 0.5 hour after ischemia induction (INT, nϭ6; OVX, nϭ8; OVXϩE2, nϭ6). Results-Lesion volume was 20.9Ϯ2.2% and 21.8Ϯ1.2% in the INT and OVX groups, respectively. E2 was found to decrease lesion volume significantly when administered within 3 hours after MCAO. The lesion volumes were 6.3Ϯ0.5%, 10.3Ϯ2.1%, 11.8Ϯ1.8%, 13.5Ϯ1.6%, and 17.9Ϯ2.8% when E2 was administered at 0.5, 1, 2, 3, or 4 hours after MCAO, respectively. CBF decreased to 43.1Ϯ2.2% and 25.4Ϯ1.0% in the INT and OVX animals, respectively, at 5 minutes after MCAO. In comparison to OVX rats, CBF was not different at 1 hour after E2 administration but was increased significantly in the OVXϩE2 group 1 and 2 days after E2 administration. Conclusions-E2 exerts neuroprotective effects when administered after ischemia, with a therapeutic window in a permanent focal cerebral ischemia model of approximately 3 hours. This effect of estradiol was associated with no immediate change in blood flow but with a delayed increase in CBF. (Stroke. 2000;31:745-750.)Key Words: cerebral blood flow Ⅲ estrogens Ⅲ ischemia Ⅲ neuroprotection B oth retrospective and prospective epidemiological studies have demonstrated beneficial effects of estrogen replacement therapy in reducing stroke-related mortality that is associated with stroke in postmenopausal women. 1,2 Recently, several laboratory studies have also emphasized the neuroprotective effects of estrogens. [3][4][5][6] Both chronic and acute pretreatment can reduce ischemic damage in focal cerebral ischemia, indicating that estrogens may be a new therapeutic class of drugs to prevent neuronal damage associated with cerebral ischemia.Presently, it is not known whether postischemic treatment with estrogen is beneficial. The purpose of this study was to determine (1) whether 17␤-estradiol (E2) can protect against brain injury when administered after cerebral ischemia; (2) the duration of any therapeutic window offered by E2, and (3) whether any E2 neuroprotec...

BackgroundChemokine (C-X3-C motif) ligand 1 (CX3CL1)/ CX3C chemokine receptor 1 (CX3CR1) signaling is important in modulating the communication between neurons and resident microglia/migrated macrophages in the central nervous system (CNS). Although CX3CR1 deficiency is associated with an improved outcome following ischemic brain injury, the mechanism of this observation is largely unknown. The aim of this study was to investigate how CX3CR1 deficiency influences microglia/macrophage functions in the context of its protection following brain ischemia.MethodsWild-type (WT) and CX3CR1-deficient (CX3CR1-/-) mice were subjected to transient middle cerebral artery occlusion (MCAO) and reperfusion. The ischemic brain damage was monitored by rodent high-field magnetic resonance imaging. Neurological deficit was assessed daily. Neuronal apoptotic death and reactive oxygen species (ROS) production were analyzed by immunostaining and live imaging. Activation/inflammatory response of microglia/macrophage were assessed using immunohistochemistry, flow cytometry, 5-bromo-2-deoxyuridine labeling, cytokine ELISA, and real-time PCR.ResultsCX3CR1-/- mice displayed significantly smaller infarcts and less severe neurological deficits compared to WT controls, following MCAO. In addition, CX3CR1-/- MCAO mice displayed fewer apoptotic neurons and reduced ROS levels. Impaired CX3CR1 signaling abrogated the recruitment of monocyte-derived macrophages from the periphery, suppressed the proliferation of CNS microglia and infiltrated macrophage, facilitated the alternative activation (M2 state) of microglia/macrophages, and attenuated their ability to synthesize and release inflammatory cytokines.ConclusionOur results suggest that inhibition of CX3CR1 signaling could function as a therapeutic modality in ischemic brain injury, by reducing recruitment of peripheral macrophages and expansion/activation of CNS microglia and macrophages, resulting in protection of neurological function.

We have studied the ultrastructural features of vascular lesions and mitochondria in brain vascular wall cells from human AD brain biopsy, human short postmortem brain tissues, and yeast artificial chromosome (YAC) and C57B6/SJL transgenic positive (Tg+) mice overexpressing amyloid beta precursor protein (AbetaPP). In situ hybridization using mitochondrial DNA (mtDNA) probes for human wild type, 5 kb deleted, and mouse mtDNA was performed, along with immunocytochemistry using antibodies against amyloid precursor protein (APP), 8-hydroxy-2'-guanosine (8-OHG), and cytochrome c oxidase (COX). There was a higher degree of amyloid deposition in the vascular walls of the human AD, YAC, and C57B6/SJL Tg (+) mice compared to age-matched controls. In addition, vessels with more severe lesions showed immunopositive staining for APP and possessed large, lipid-laden vacuoles in the cytoplasm of endothelial cells (EC). Significantly more mitochondrial abnormalities were seen in human AD, YAC, and C57B6/SJL Tg (+) mouse microvessels where lesions occurred. In situ hybridization using wild and chimera (5 kb) mtDNA probes revealed positive signals in damaged mitochondria from the vascular endothelium and in perivascular cells of lesioned microvessels close to regions of large amyloid deposition. These features were absent in undamaged regions of human AD tissues, YAC and C57B6/SJL Tg (+) mouse tissues, and in age-matched control subjects. In addition, vessels with atherosclerotic lesions revealed endothelium and perivascular cells possessing clusters of wild and deleted mtDNA positive probes. These mtDNA deletions were accompanied by increased amounts of immunoreactive APP, 8-OHG, and COX in the same cellular compartment. Our observations demonstrate that vascular wall cells, especially their mitochondria, appear to be a central target for oxidative stress-induced damage.