Midkine, a novel neurotrophic factor, is present in senile plaques of Alzheimer disease

An affinity purified antibody specific for midkine (MK) stained senile plaques in the brain of Alzheimer disease (AD) patients. After formic acid treatment, plaque staining was dramatically enhanced, and almost all beta-amyloid protein (BAP) deposits were also immunoreactive for MK. MK-immunoreactivity was not observed in normal cellular components nor in other pathological lesions including tangles in AD brain. Control brain sections were not immunoreactive for MK. The presence of MK in AD brain but not in control brain was confirmed by Western blotting. MK appears to be involved in the pathological process leading to senile plaque formation.     

Glial fibrillary acidic protein-apolipoprotein E (apoE) transgenic mice: astrocyte-specific expression and differing biological effects of astrocyte-secreted apoE3 and apoE4 lipoproteins

The epsilon4 allele of apolipoprotein E (apoE) is associated with increased risk for Alzheimer's disease (AD) and poor outcome after brain injury. In the CNS, apoE is expressed by glia, predominantly astrocytes. To define the potential biological functions of different human apoE isoforms produced within the brain, transgenic mice were generated in which human apoE3 and apoE4 expression is under control of the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter. These animals were then bred back to apoE knock-out mice. Human apoE protein is found within astrocytes and the neuropil throughout development and into the adult period, as assessed by immunocytochemistry and immunoblot analysis in several GFAP-apoE3 and E4 lines. Cultured astrocytes from these mice secrete apoE3 and apoE4 in lipoproteins that are high-density lipoprotein-like in size. When primary hippocampal neurons are grown in the presence of astrocyte monolayers derived from these transgenic mice, there is significantly greater neurite outgrowth from neurons grown in the presence of apoE3-secreting astrocytes compared with apoE4-secreting or apoE knock-out astrocytes. These effects are not dependent on direct astrocyte-neuron contact and appear to require the low-density lipoprotein receptor-related protein. These data suggest that astrocyte-secreted, apoE3-containing lipoproteins have different biological effects than apoE4-containing lipoproteins. In addition to providing information regarding the role of astrocyte-secreted apoE lipoproteins in the normal brain, these animals will also be useful in models of both AD and CNS injury.     

Laparoscopic management of a noncommunicating uterine horn in a patient with an acute abdomen

INTRODUCTION: The presence of the apolipoprotein E4 allele (apoE4) has been recognized as a risk factor for the development of presenile and senile forms of Alzheimer's dementia (AD). MATERIAL AND METHODS: The apoE alleles frequency of 71 normal controls (NC), 60 demented controls (DC) and 50 senile type AD subjects was determined by polymerase chain reaction in order to get data about the apoE polymorphism of the Hungarian AD population. RESULTS: The apoE3/3 genotype was the most common in all groups. The apoE4 frequency was significantly higher (28%) in the AD group than that was (7% and 9%) in the NC and DC populations, respectively. No apoE4 homozygotes were found in the DC group and the number of heterozygotes was lower in the DC than in the AD group. CONCLUSION: The results are in good agreement with others in the literature and support the occurrence of an increased apoE4 allele frequency in Hungarian senile AD population.     

Apolipoprotein E in the brain and its role in Alzheimer's disease

Recent evidence indicates that apolipoprotein E (apoE) plays a central role in the brain response to injury. The coordinated expression of apoE and its main receptor, the apoE/apoB (LDL) receptor, appears to regulate the transport of cholesterol and phospholipids during the different phases of the reinnervation process. The recent discovery that a peculiar form of apoE, the apoE4, is strongly linked to both sporadic and familial late onset Alzheimer's disease (AD) raises the possibility that a dysfunction of the lipid transport system associated with compensatory sprouting and synaptic remodelling could be central to the AD process. The role of apoE in the central nervous system (CNS) is particularly important in relation to the function of the cholinergic system which relies to a certain extent on the integrity of phospholipid homeostasis in neurons. Recent evidence suggests that apoE4 allele has a direct impact on cholinergic function in AD.     

Apolipoprotein E accumulates with the progression of A beta deposition in transgenic mice

To study the role of apolipoprotein E (apoE) in vivo in deposits of amyloid beta protein (A beta), a major component of senile plaque amyloid in the brain of patients with Alzheimer disease, the transgenic mice were examined by apoE immunostaining. The mice were systemically overexpressing signal peptide and 99 amino acid residues of the carboxy-terminal fragment of human amyloid beta protein precursor (betaAPP) under control of the powerful cytomegalovirus enhancer/chicken beta-actin promotor. A beta deposits appeared at 4 months and increased with aging in the acinar cells of the transgenic pancreas. Similarly, apoE deposits appeared in the pancreatic acinar cells at 4 months old. The number and size of apoE deposits increased with aging and correlated with the progression of A beta deposits. Interstitial macrophages labeled by apoE immunostaining appeared at 8 months after birth and their number increased with aging. On serial section of the pancreata of 24-month-old mice, approximately 70% of A beta deposits were labeled with the apoE antiserum. ApoE was detected in the highly insoluble formic acid fraction of the transgenic pancreas by an immunoblot study. The Northern blot study revealed no increase in synthesis of endogenous apoE mRNA. These findings indicate that apoE is closely related to progression of A beta deposits with aging and suggest that A beta deposition in the transgenic pancreas is similar to that in the senile plaque of Alzheimer brains. Therefore, our experimental system using transgenic mice will provide a useful tool to analyze the molecular mechanism of A beta deposition in association with apoE in vivo.     

In situ hybridization analysis of presenilin 1 mRNA in Alzheimer disease and in lesioned rat brain

Presenilin-1 (PS-1) gene mutations are responsible for the majority of the early onset familial forms of Alzheimer disease (AD). Neither PS-1's anatomic distribution in brain nor expression in AD have been reported. Using in situ hybridization in the rat forebrain, we show that PS-1 mRNA expression is primarily in cortical and hippocampal neurons, with less expression in subcortical structures, in a regional pattern similar to APP695. Excitotoxic lesions lead to loss of PS-1 signal. A neuronal pattern of expression of PS-1 mRNA was also observed in the human hippocampal formation. AD and control levels did not differ. PS-1 is expressed in brain areas vulnerable to AD changes more so than in areas spared in AD; however, PS-1 expression is not sufficient to mark vulnerable regions. Collectively, these data suggest that the neuropathogenic process consequent to PS-1 mutations begins in neuronal cell populations.     

Brain infarction and the clinical expression of Alzheimer disease. The Nun Study

OBJECTIVE: To determine the relationship of brain infarction to the clinical expression of Alzheimer disease (AD). DESIGN: Cognitive function and the prevalence of dementia were determined for participants in the Nun Study who later died. At autopsy, lacunar and larger brain infarcts were identified, and senile plaques and neurofibrillary tangles in the neocortex were quantitated. Participants with abundant senile plaques and some neurofibrillary tangles in the neocortex were classified as having met the neuropathologic criteria for AD. SETTING: Convents in the Midwestern, Eastern, and Southern United States. PARTICIPANTS: A total of 102 college-educated women aged 76 to 100 years. MAIN OUTCOME MEASURES: Cognitive function assessed by standard tests and dementia and AD assessed by clinical and neuropathologic criteria. RESULTS: Among 61 participants who met the neuropathologic criteria for AD, those with brain infarcts had poorer cognitive function and a higher prevalence of dementia than those without infarcts. Participants with lacunar infarcts in the basal ganglia, thalamus, or deep white matter had an especially high prevalence of dementia, compared with those without infarcts (the odds ratio [OR] for dementia was 20.7, 95% confidence interval [95% CI], 1.5-288.0). Fewer neuropathologic lesions of AD appeared to result in dementia in those with lacunar infarcts in the basal ganglia, thalamus, or deep white matter than in those without infarcts. In contrast, among 41 participants who did not meet the neuropathologic criteria for AD, brain infarcts were only weakly associated with poor cognitive function and dementia. Among all 102 participants, atherosclerosis of the circle of Willis was strongly associated with lacunar and large brain infarcts. CONCLUSION: These findings suggest that cerebrovascular disease may play an important role in determining the presence and severity of the clinical symptoms of AD.     

Immunolocalization and redistribution of the FAC1 protein in Alzheimer's disease

The presence of senile plaques and neurofibrillary tangles are hallmark neuropathologic features of Alzheimer's disease (AD). Many proteins have previously been immunolocalized to amyloid-containing plaques in AD brain. Using a monoclonal antibody to a recently described developmentally regulated gene product, we demonstrate the presence of FAC1 protein in a subset of diffuse and neuritic plaques in AD brain. FAC1 is not observed in neurofibrillary tangles common in the hippocampus or entorhinal cortex, nor is it localized in diffuse plaques of nondemented elderly control subjects. FAC1 protein is also immunolocalized in swollen dendrites of hippocampal pyramidal cells observed in some cases of early stage AD. Therefore, FAC1 is a novel protein localized in early pathologic features of AD and in a subset of plaques.     

Fibroblast growth factor (FGF)-9 immunoreactivity in senile plaques

We examined fibroblast growth factor (FGF)-9 immunoreactivity in human hippocampal sections of Alzheimer's disease (AD). FGF-9 immunoreactivity was observed in dystrophic neurites of senile plaques in AD and control cases, in addition to the hippocampal and cortical neurons. The amyloid core and neurofibrillary tangles lacked immunoreactivity. FGF-9 immunoreactive astrocytes were conspicuous in AD brains. FGF-9 may be involved in the neuropathology of AD.     

Physiological actions of the neuropeptide Antho-RNamide on antagonistic muscle systems in sea anemones

Several studies have reported that the bulk aluminum (Al) concentration is increased in the brain in Alzheimer disease (AD), while other studies have failed to demonstrate an increase. Most of these investigations have had one or more methodological deficiencies, including lack of adequate neuropathological assessment; failure to age-match the control samples; small sample sizes, lacking statistical power; and geographical heterogeneity in the AD and control populations. The present population-based study of 92 clinically and histopathologically diagnosed AD patients and normal elderly nursing home residents was designed to avoid these potential biases. When a subsample of AD cases with the most severe brain pathology was compared with controls having no or minimal pathology, no statistically significant differences were found in the bulk aluminum concentration measured by graphite furnace atomic absorption spectrometry in frontal cortex (1.8 +/- 0.7 vs. 1.7 +/- 0.7 micrograms/g dry wt), temporal cortex (1.4 +/- 0.3 vs. 1.5 +/- 0.5 micrograms/g dry wt), liver (2.0 +/- 1.3 vs. 2.0 +/- 1.2 micrograms/g dry wt), or head of femur (2.4 +/- 1.6 vs. 2.2 +/- 1.0 micrograms/g ash wt). Within the whole series of 92 cases, there was no difference in the bulk aluminum concentration of the frontal cortex between individuals diagnosed as definite, probable, and possible cases of AD using the CERAD (Consortium to Establish a Registry for Alzheimer's Disease) criteria. The density of senile plaques and neurofibrillary tangles in frontal and temporal cortex showed no correlation with the bulk aluminum concentration. Logistic regression analyses, which controlled for age and sex, did not influence outcome for any of the comparisons. The data show conclusively that in AD, bulk aluminum concentration is not increased in two cortical brain regions that are selectively vulnerable to the neuropathological changes associated with this disorder.     

Chromosomal disorders and autism

Two major risk factors for late-onset familial and sporadic Alzheimer disease (AD), a leading cause of dementia worldwide, are increasing age and inheritance of the epsilon4 allele of the apolipoprotein E gene (APOE4). Several isoform-specific effects of apoE have been proposed; however, the mechanisms by which apoE isoforms influence the pathogenesis of AD are unknown. Also associated with AD is increased lipid peroxidation in the regions of the brain most damaged by disease. 4-hydroxynonenal (HNE), the most potent neurotoxic product of lipid peroxidation, is thought to be deleterious to cells through reactions with protein nucleophiles. We tested the hypothesis that accumulation of the most common forms of HNE-protein adducts, borohydride-reducible adducts, is associated with AD and examined whether there was a relationship to APOE. Our results demonstrated that reducible HNE adducts were increased in the hippocampus, entorhinal cortex, and temporal cortex of patients with AD. Furthermore, our data showed that the pattern of reducible HNE adduct accumulation was related to APOE genotype; AD patients homozygous for APOE4 had pyramidal neuron cytoplasmic accumulation of reducible HNE adducts, while AD APOE3 homozygotes had both pyramidal neuron and astrocyte accumulation of reducible HNE adducts. This is in contrast to our previous observations that a distinct HNE protein adduct, the pyrrole adduct, accumulates on neurofibrillary tangles in AD patients. We conclude that APOE genotype influences the cellular distribution of increased reducible HNE adduct accumulation in AD.     

Cerebrovascular transport of Alzheimer's amyloid beta and apolipoproteins J and E: possible anti-amyloidogenic role of the blood-brain barrier

It is uncertain whether soluble circulating amyloid beta (sA beta) is the precursor of amyloid beta (A beta) found in cerebrovascular and parenchymal amyloid lesions in Alzheimer's Disease, and if so, how the transition to the filamentous form is brought about. Several lines of evidence suggest that apolipoprotein E (apoE) and apolipoprotein J (apoJ) may be involved in the regulation of amyloidogenesis. They both bind sA beta/A beta in vivo and in vitro. It has been suggested that apoE may modulate beta-pleated conformation of A beta and therefore act as a proamyloidogenic factor. On the other hand, apoJ as a major carrier protein of sA beta in body fluids may keep the peptide in a soluble form, thus having an anti-amyloidogenic effect. Using a well established guinea-pig brain perfusion model we have studied the blood-brain barrier (BBB) processes involved in the regulation of cerebral capillary sequestration, transport and metabolism of i) sA beta 1-40 and sA beta 1-42, synthetic peptides identical to the 40 and 42 residue forms of A beta, found primarily in vascular deposits and senile plaques, respectively; and ii) apoJ, apoE3 and apoE4 alone, and in a complex with sA beta. Specific saturable BBB luminal binding of both peptides was followed by transport into brain parenchyma and metabolism at the abluminal side of the BBB and/or in brain. The capillary sequestration of sA beta 1-40 was significant, while retention by the microvasculature of sA beta 1-42 was negligible. Binding to microvessels and blood-to-brain transport of both intact apoJ and sA beta 1-40 apoJ complexes were among the highest ever recorded for peptides and proteins at the BBB in vivo. These processes appear to be mediated by glycoprotein 330 (gp330/megalin), a receptor for multiple ligands, including apoJ. In contrast, capillary retention and transport of apoE3, apoE4 and sA beta 1-40-apoE3 complex were low to negligible, while blood-brain transport of sA beta 1-40-apoE4 was moderate. It is suggested that normal BBB may have predominantly anti-amyloidogenic functions by i) degrading sA beta during blood-to-brain transport; ii) favoring sequestration and transport of apoJ alone and in complex with sA beta via gp330 receptor-mediated mechanism and iii) excluding apoE3 and apoE4 isoforms from brain.     

Novel large apolipoprotein E-containing lipoproteins of density 1.006-1.060 g/ml in human cerebrospinal fluid

Although the critical role of apolipoprotein E (apoE) allelic variation in Alzheimer's disease and in the outcome of CNS injury is now recognized, the functions of apoE in the CNS remain obscure, particularly with regard to lipid metabolism. We used density gradient ultracentrifugation to identify apoE-containing lipoproteins in human CSF. CSF apoE lipoproteins, previously identified only in the 1.063-1.21 g/ml density range, were also demonstrated in the 1.006-1.060 g/ml density range. Plasma lipoproteins in this density range include low-density lipoprotein and high-density lipoprotein (HDL) subfraction 1 (HDL1). The novel CSF apoE lipoproteins are designated HDL1. No immunoreactive apolipoprotein A-I (apo A-I) or B could be identified in the CSF HDL1 fractions. Large lipoproteins 18.3 +/- 6.6 nm in diameter (mean +/- SD) in the HDL1 density range were demonstrated by electron microscopy. Following fast protein liquid chromatography of CSF at physiologic ionic strength, apoE was demonstrated in particles of average size greater than particles containing apoA-I. The largest lipoproteins separated by this technique contained apoE without apoA-I. Thus, the presence of large apoE-containing lipoproteins was confirmed without ultracentrifugation. Interconversion between the more abundant smaller apoE-HDL subfractions 2 and 3 and the novel larger apoE-HDL1 is postulated to mediate a role in cholesterol redistribution in brain.     

Multiple processes are involved in the uptake of chylomicron remnants by mouse peritoneal macrophages

The processes responsible for the uptake of chylomicron remnants by macrophages were investigated using freshly isolated cells from low density lipoprotein (LDL) receptor, very low density lipoprotein (VLDL) receptor and apolipoprotein E knockout mice. In peritoneal macrophages from normal mice, the metabolism of chylomicron remnants was inhibited 40% by anti-LDL receptor antibody and 60% by a high concentration of receptor-associated protein (RAP). Together they reduced the amount processed by 70%. Digestion of cell proteoglycans decreased remnant degradation by 20% while the addition of acetyl-LDL had no effect. When LDL receptors were absent, the absolute rates of metabolism were less than that of normal cells and were not inhibited by the anti-LDL receptor antibody; the rates, however, were reduced to less than half by RAP. These suggest that the LDL receptor-related protein (LRP) or another LDL receptor family member(s) contributes to chylomicron remnant uptake and becomes the major mechanism of uptake when LDL receptors are absent. In contrast, the VLDL receptor was not involved as its absence did not affect chylomicron remnant metabolism. Similarly, the absence of apoE production did not affect the amount of remnant uptake; however, the proportion that was sensitive to RAP was eliminated. The level of LRP expression was not altered in these cells whereas there was a decrease in LDL receptors. This suggests that the apoE content of chylomicron remnants is sufficient for its recognition by LDL receptors but additional apoE is required for its uptake by the LRP and that there is an up-regulation of a non-LDL receptor family mechanism in apoE deficiency. Together these studies suggest that even in the absence of LDL receptors or apoE secretion, chylomicron remnants could contribute to lipid accumulation in the artery wall during atherogenesis.     

Alzheimer disease, markers in the cerebrospinal fluid. Support of physiopathologic hypotheses

CERTAIN DIAGNOSIS: Because the certainty diagnosis of Alzheimer's disease is defined after autopsy or brain biopsy by the presence of neurofibrillar degeneration (NFD), extracellular senile plaques and vascular deposits of amyloid in the hippocampus amygdalus and the cerebral cortex, some authors have searched for biological ante-mortem markers of AD, particularly in the cerebrospinal fluid (CSF) which is essentially derived from brain tissue. SEARCH FOR MARKERS: Studies have investigated the CSF level of neurotransmitters, neuropeptides, amino acids, trace elements, constituents of NFD and senile plaques in a diagnostic and pathogenic perspective. HOPE FOR DIAGNOSIS: Even though ethical, technical and methodological difficulties met by authors are important and even though many clinical and biological parameters must be taken into account, these studies bring important pathogenic evidence and allow hope that markers of AD which are so necessary for early diagnosis and objective study of therapies will be found.     

Pilocarpine tablets for the treatment of dry mouth and dry eye symptoms in patients with Sj?gren syndrome: a randomized, placebo-controlled, fixed-dose, multicenter trial. P92-01 Study Group

The sequestration of RNA in Alzheimer's disease (AD) senile plaques (SPs) and the production of intraneuronal amyloid-beta peptides (Abeta) prompted analysis of the mRNA profile in single immunocytochemically identified SPs in sections of AD hippocampus. By using amplified RNA expression profiling, polymerase chain reaction, and in situ hybridization, we assessed the presence and abundance of 51 mRNAs that encode proteins implicated in the pathogenesis of AD. The mRNAs in SPs were compared with those in individual CA1 neurons and the surrounding neuropil of control subjects. The remarkable demonstration here, that neuronal mRNAs predominate in SPs, implies that these mRNAs are nonproteinaceous components of SPs, and, moreover, that mRNAs may interact with Abeta protein and that SPs form at sites where neurons degenerate in the AD brain.