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The Ediacaran of eastern Newfoundland preserves the world's oldest known eumetazoan body fossils, as well as the earliest known record of fossilized muscular tissue. Re-examination of the holotype of the eight-armed Haootia quadriformis in terms of its morphology, the arrangement of its muscle filament bundles, and hitherto undescribed aspects of its anatomy support its interpretation as a crown staurozoan. We also document several new fossils preserving muscle tissue with a different muscular architecture to Haootia , but with only four arms. This new material allows us to describe a new crown group staurozoan, Mamsetia manunis gen. et sp. nov. This work confirms the presence of crown group medusozoan cnidarians of the Staurozoa in the Ediacaran of Newfoundland circa 565 Ma.

Immune system dysfunction is increasingly recognized as a significant feature that contributes to Alzheimer's disease (AD) pathogenesis, reflected by alterations in central and peripheral responses leading to detrimental mechanisms that can contribute to the worsening of the disease. The damaging alterations in the peripheral immune system may disrupt the peripheral-central immune crosstalk, implicating the gut microbiota in this complex interaction. The central hypothesis posits that the immune signature inherently harbored in bone marrow (BM) cells can be transferred through allogeneic transplantation, influencing the recipient's immune system and modulating peripheral, gut, and brain immune responses. Employing a genetically modified mouse model to develop AD-type pathology we found that recipient wild-type (WT) mice engrafted with AD-derived BM, recapitulated the peripheral immune inflammatory donor phenotype, associated with a significant acceleration of cognitive deterioration in the absence of any overt change in AD-type amyloid neuropathology. Moreover, transcriptomic and phylogenetic 16S microbiome analysis evidence on these animals revealed a significantly impaired expression of genes associated with synaptic plasticity and neurotransmission in the brain and reduced bacteria diversity, respectively, compared to mice engrafted with WT BM. This investigation sheds light on the pivotal role of the peripheral immune system in the brain-gut-periphery axis and its profound potential to shape the trajectory of AD. In summary, this study advances our understanding of the complex interplay among the peripheral immune system, brain functionality, and the gut microbiome, which collectively influence AD onset and progression., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Aims: The Gulf War Illness programs (GWI) of the United States Department of Veteran Affairs and the Department of Defense Congressionally Directed Medical Research Program collaborated with experts to develop Common Data Elements (CDEs) to standardize and systematically collect, analyze, and share data across the (GWI) research community., Main Methods: A collective working group of GWI advocates, Veterans, clinicians, and researchers convened to provide consensus on instruments, case report forms, and guidelines for GWI research. A similar initiative, supported by the National Institute of Neurologic Disorders and Stroke (NINDS) was completed for a comparative illness, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and provided the foundation for this undertaking. The GWI working group divided into two sub-groups (symptoms and systems assessment). Both groups reviewed the applicability of instruments and forms recommended by the NINDS ME/CFS CDE to GWI research within specific domains and selected assessments of deployment exposures. The GWI CDE recommendations were finalized in March 2018 after soliciting public comments., Key Findings: GWI CDE recommendations are organized in 12 domains that include instruments, case report forms, and guidelines. Recommendations were categorized as core (essential), supplemental-highly recommended (essential for specified conditions, study types, or designs), supplemental (commonly collected, but not required), and exploratory (reasonable to use, but require further validation). Recommendations will continually be updated as GWI research progresses., Significance: The GWI CDEs reflect the consensus recommendations of GWI research community stakeholders and will allow studies to standardize data collection, enhance data quality, and facilitate data sharing., (Copyright © 2018. Published by Elsevier Inc.)

Both plant and mammalian cells express glucuronosyltransferases that catalyze glucuronidation of polyphenols such as flavonoids and other small molecules. Oral administration of select polyphenolic compounds leads to the accumulation of the corresponding glucuronidated metabolites at μM and sub-μM concentrations in the brain, associated with amelioration of a range of neurological symptoms. Determining the mechanisms whereby botanical extracts impact cognitive wellbeing and psychological resiliency will require investigation of the modes of action of the brain-targeted metabolites. Unfortunately, many of these compounds are not commercially available. This article describes the latest approaches for the analysis and synthesis of glucuronidated flavonoids. Synthetic schemes include both standard organic synthesis, semisynthesis, enzymatic synthesis and use of synthetic biology utilizing heterologous enzymes in microbial platform organisms.

Grape seed polyphenolic extract (GSPE) rich in the flavan-3-ols (+)-catechin and (-)-epicatechin beneficially modulates Alzheimer's Disease phenotypes in animal models. The parent molecules in the extract are converted to a series of methylated and glucuronidated derivatives. To fully characterize these metabolites and establish a robust quantitative assay of their levels in biological fluids, we have implemented a partial synthetic approach utilizing chemical methylation followed by enzymatic glucuronidation. Liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS) and nuclear magnetic resonance (NMR) spectroscopy were used to assign unequivocal structures to the compounds. An analytical method using solid-phase extraction and LC-MS/MS in selective reaction monitoring mode (SRM) was validated for their quantitation in plasma. These studies provide a basis for improvements in future work on the bioavailability, metabolism, and mechanism of action of metabolites derived from dietary flavan-3-ols in a range of interventions.

Axonal damage is a prominent cause of disability and yet its pathogenesis is incompletely understood. Using a xenogeneic system, here we define the bioenergetic changes induced in rat neurons by exposure to cerebrospinal fluid samples from patients with multiple sclerosis compared to control subjects. A first discovery cohort of cerebrospinal fluid from 13 patients with multiple sclerosis and 10 control subjects showed that acute exposure to cerebrospinal fluid from patients with multiple sclerosis induced oxidative stress and decreased expression of neuroprotective genes, while increasing expression of genes involved in lipid signalling and in the response to oxidative stress. Protracted exposure of neurons to stress led to neurotoxicity and bioenergetics failure after cerebrospinal fluid exposure and positively correlated with the levels of neurofilament light chain. These findings were validated using a second independent cohort of cerebrospinal fluid samples (eight patients with multiple sclerosis and eight control subjects), collected at a different centre. The toxic effect of cerebrospinal fluid on neurons was not attributable to differences in IgG content, glucose, lactate or glutamate levels or differences in cytokine levels. A lipidomic profiling approach led to the identification of increased levels of ceramide C16:0 and C24:0 in the cerebrospinal fluid from patients with multiple sclerosis. Exposure of cultured neurons to micelles composed of these ceramide species was sufficient to recapitulate the bioenergetic dysfunction and oxidative damage induced by exposure to cerebrospinal fluid from patients with multiple sclerosis. Therefore, our data suggest that C16:0 and C24:0 ceramides are enriched in the cerebrospinal fluid of patients with multiple sclerosis and are sufficient to induce neuronal mitochondrial dysfunction and axonal damage., (© The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Diffuse axonal injury is a common pathological consequence of Traumatic Brain Injury (TBI). Diffusion Tensor Imaging is an ideal technique to study white matter integrity using the Fractional Anisotropy (FA) index which is a measure of axonal integrity and coherence. There have been several reports showing reduced FA in individuals with TBI, which suggest demyelination or reduced fiber density in white matter tracts secondary to injury. Individuals with TBI are usually diagnosed with cognitive deficits such as reduced attention span, memory and executive function. In this study we sought to investigate correlations between brain functional networks, white matter integrity, and TBI severity in individuals with TBI ranging from mild to severe. A resting state functional magnetic resonance imaging protocol was used to study the default mode network in subjects at rest. FA values were decreased throughout all white matter tracts in the mild to severe TBI subjects. FA values were also negatively correlated with TBI injury severity ratings. The default mode network showed several brain regions in which connectivity measures were higher among individuals with TBI relative to control subjects. These findings suggest that, subsequent to TBI, the brain may undergo adaptation responses at the cellular level to compensate for functional impairment due to axonal injury.

The identification of biomarkers represents a fundamental medical advance that can lead to an improved understanding of disease pathogenesis, and holds the potential to define surrogate diagnostic and prognostic endpoints. Because of the inherent difficulties in assessing brain function in patients and objectively identifying neurological and cognitive/emotional symptoms, future application of biomarkers to neurological and psychiatric disorders is extremely desirable. This article discusses the biomarker potential of the granin family, a group of acidic proteins present in the secretory granules of a wide variety of endocrine, neuronal and neuroendocrine cells: chromogranin A (CgA), CgB, Secretogranin II (SgII), SgIII, HISL-19 antigen, 7B2, NESP55, VGF and ProSAAS. Their relative abundance, functional significance, and secretion into the cerebrospinal fluid (CSF), saliva, and the general circulation have made granins tractable targets as biomarkers for many diseases of neuronal and endocrine origin, recently impacting diagnosis of a number of neurological and psychiatric disorders including amyotrophic lateral sclerosis (ALS), Alzheimer's disease, frontotemporal dementia, and schizophrenia. Although research has not yet validated the clinical utility of granins as surrogate endpoints for the progression or treatment of neurological or psychiatric disease, a growing body of experimental evidence indicates that the use of granins as biomarkers might be of great potential clinical interest. Advances that further elucidate the mechanism(s) of action of granins, coupled with improvements in biomarker technology and direct clinical application, should increase the translational effectiveness of this family of proteins in disease diagnosis and drug discovery., (Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.)

Epidemiological evidence suggests that hypertension may accelerate the onset and progression of Alzheimer's disease (AD). In this study, we explored the role of hypertension in the neurodegenerative changes associated with Abeta and tau aggregation. We induced hypertension in APP(swe) Tg2576 and P301L-tauTg mouse models. In Tg2576 mice, experimental hypertension was associated with a significant increase of the accumulation of Amyloid-beta (Abeta) peptides in brain tissue and a significant reduction of Abeta peptides in serum (P < .05). These results indicate that hypertension may promote AD-type Abeta neuropathology in Tg2576. In P301L-tauTg mice we found that the presence of hypertension was significantly associated with aggravated motor function assessed by hindlimb extension test (P = .01). These results suggest that hypertension may play a role in accelerating the progression of motor dysfunction associated with tau-related alterations. Our studies suggest that the management of blood pressure (BP) may alleviate AD-type Abeta neuropathology and neurological disorders associated with abnormal tau metabolism.

Cyclooxygenase-2 (COX-2) is up-regulated during ischemia. However, the role of COX-2 in neuronal injury is still unclear. In this study we tested whether neuronal overexpression of human COX-2 in a transgenic mouse model potentiates neuronal injury after global ischemic insult. Further, we tested whether the neuronal injury could be ameliorated by intra-ischemic mild hypothermia (33-34 degrees C) alone or in combination with diet treatment of rofecoxib, a COX-2 specific inhibitor. Global ischemia with intra-ischemic normothermia (36-37 degrees C) resulted in significantly higher neuronal damage in the CA1 region of hippocampus of transgenic mice than in wild type controls, confirming a deleterious role of COX-2 in ischemic neuronal damage. Hypothermia significantly reduced neuronal damage in both transgenic mice and wild type controls to the same extent, suggesting that the aggravating effect of COX-2 could be largely eliminated by hypothermia. When hypothermia was combined with rofecoxib treatment, neuronal damage was further reduced in response to global ischemia. The results suggest that COX-2 inhibition by prophylactic treatment with rofecoxib coupled with hypothermia at the time of acute stroke insult could be an effective therapeutic approach in early stages of stroke treatment in high risk patients.

Background: The clinical diagnosis of ALS is based entirely on clinical features. Identification of biomarkers for ALS would be important for diagnosis and might also provide clues to pathogenesis., Objective: To determine if there is a specific protein profile in the CSF that distinguishes patients with ALS from those with purely motor peripheral neuropathy (PN) and healthy control subjects., Methods: CSF obtained from patients with ALS, disease controls (patients with other neurologic disorders), and normal controls were analyzed using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry proteomics technique. Biomarker sensitivity and specificity was calculated with receiver operating characteristic curve methodology. ALS biomarkers were purified and sequence identified by mass spectrometry-directed peptide sequencing., Results: In initial proteomic discovery studies, three protein species (4.8-, 6.7-, and 13.4-kDa) that were significantly lower in concentration in the CSF from patients with ALS (n = 36) than in normal controls (n = 21) were identified. A combination of three protein species (the "three-protein" model) correctly identified patients with ALS with 95% accuracy, 91% sensitivity, and 97% specificity from the controls. Independent validation studies using separate cohorts of ALS (n = 13), healthy control (n = 25), and PN (n = 7) subjects confirmed the ability of the three CSF protein species to separate patients with ALS from other diseases. Protein sequence analysis identified the 13.4-kDa protein species as cystatin C and the 4.8-kDa protein species as a peptic fragment of the neurosecretory protein VGF., Conclusion: Additional application of a "three-protein" biomarker model to current diagnostic criteria may provide an objective biomarker pattern to help identify patients with ALS.

The present study was designed to further explore the potential cause/effect relationship between the expression of both the N141I presenilin (PS)2 mutant familial Alzheimer's disease (FAD) gene and cyclooxgenase (COX) in respect to the mechanism associated with programmed cell death in Alzheimer's disease (AD). We found that expression of mutant N141I PS2 resulting in apoptotic cell death in H4 neuronal cells coincided with >4-fold induction in the expression of the inducible form of COX-2, but not the constitutive COX-1. Moreover, we found that the expression of the N141I PS2 FAD gene strongly promoted (>2-fold) glycogen synthase kinase (GSK)-3beta activity coincidental with a reduction in the level of beta-catenin translocated from the cytoplasmic to the nuclear compartment. Most interestingly, we found that inhibition of COX-2-mediated generation of prostaglandin (PG)-E2 in H4 neuronal cells with the preferential COX-2 inhibitor nimesulide protects against N141I PS2-mediated apoptotic cell death coincidental with an inhibition of GSK-3beta activity and subsequent normalization of beta-catenin cellular distribution. The clinical relevance of this finding was confirmed by the evidence that COX-2 protein and PG-E2 concentrations were selectively increased >2-fold in the cerebral cortex of subjects harboring the N141I PS2 FAD mutation relative to wild-type PS2 AD cases. This study demonstrates for the first time that COX-2 may be a downstream effector of mutant N141I PS2-mediated apoptotic cell death and that inhibition of COX-2 may neuroprotect in AD through modulation of a GSK-3beta-beta-catenin-mediated response. The study provides support for the potential pharmacogenomic identification of N141I PS2 FAD cases that might preferentially benefit from inhibition of COX-2 during the progression of clinical dementia.

We have reported recently that the microtubule-associated protein tau is phosphorylated in vitro by Akt, an important kinase in anti-apoptotic signaling regulated by insulin and growth factors. We also established that Akt phosphorylates tau separately at T212 and S214, two sites previously shown to be phosphorylated by glycogen synthase kinase 3beta (GSK3beta) and protein kinase A (PKA), respectively. In the present studies, we examined the relationship between Akt and T212/S214 in primary cultures of human neurons and astrocytes, and evaluated the contribution of two other kinases. In intact cells, we found a very low content of active (phospho-S473) form of Akt. We also found a low content of phospho-S214 but not phospho-T212 of tau, suggesting that only phospho-S212 may depend on Akt activity in situ. We upregulated Akt activity using two experimental models: treatment with a protein phosphatase inhibitor, okadaic acid, and transfection with a constitutively active Akt gene construct (c-Akt). Under these conditions, phosphorylation of tau at T212 and S214 was regulated independently, with little change or downregulation of phospho-T212 and dynamic upregulation of phospho-S214. Our studies revealed that Akt may influence the phospho-S214 content in a meaningful manner. They also revealed that PKA may only partially contribute to the phosphorylation of S214. In comparison, okadaic acid treatment severely depleted the content of GSK3beta and downregulated the remaining GSK3beta activity by Akt-dependent inhibition, consistent with minimal changes in phospho-T212. In summary, these results strongly suggest that in primary cultures, Akt selectively phosphorylates tau at S214 rather than T212. Our studies raise the possibility that tau S214 may participate in Akt-mediated anti-apoptotic signaling.

In exploring the causative role of the most common Pro(301)-to-Leu (TauP301L) tau missense mutation associated with neurodegenerative tauopathies, we examined TauP301L-mediated apoptotic cell death and the expression of a cluster of genes involved in the inhibition of apoptosis (IAPs) in human neuroblastoma SH-SY5Y cells. Our research found that the expression of TauP301L, but not wild-type tau, down regulated the expression of IAPs, including survivin, which plays a role in the mitotic spindle checkpoint. The inhibition of IAPs coincided with the activation of the pro-apoptotic caspase 3, but preceded apoptotic cell death by TUNEL. Furthermore, TauP301L altered the expression of the cell cycle regulatory proteins and induced the cell cycle arrest at G(2)/M phase. Our studies demonstrate that TauP301L downregulates the expression of genes that protect against apoptosis and regulate cell cycle progression. These results suggest a novel mechanism of apoptotic cell death in TauP301L-expressing cells that involves survivin-mediated activation of cell cycle checkpoint.

Recent studies indicate that the proinflammatory enzyme cyclooxygenase (COX)-2, an enzyme involved in inflammatory cascades but also normal neuronal activities, is elevated in the brain and spinal cord of amyotrophic lateral sclerosis (ALS) patients and ALS mouse model systems. On the basis of this evidence, we explored the impact of COX-2 inhibition on the onset and progression of ALS-like disease in the G93A human superoxide dismutase (SOD)1 mouse model of ALS. We found that prophylactic administration of nimesulide, a preferential COX-2 inhibitor, in the feed resulted in a significant delay in the onset of ALS type motor impairment. This delay of ALS symptomatology temporally overlapped with the inhibition of prostaglandin E2 elevation in the spinal cord of SOD1-G93A transgenic mice relative to untreated SOD1-G93A controls. This study strongly supports a role for COX-2 in the pathophysiology of ALS and provides the first experimental evidence that prophylactic treatment with COX-2 inhibitors can significantly delay the onset of motor dysfunction in the SOD1-G93A transgenic mouse model of ALS.

Objective: The goal of this study was to derive a systematic approach for the identification of protein species profiles that selectively identify subgroups of similar but distinct pain models and correlate with the therapeutic efficacy (or lack thereof) of drug intervention., Methods: Using high-throughput surface-enhanced laser desorption ionization (SELDI) mass spectrometry proteomic technology based on ProteinChip arrays, we conducted a comparative analysis of the profile of protein expression in cerebral spinal fluid (CSF) from rats exposed to either injection of complete Freund's adjuvant (CFA) [a model of inflammatory pain] or chronic constriction injury (CCI) [a model of neuropathic pain]. The CFA model was then further studied for the effects of treatment with the NSAID, nimesulide (a preferential cyclo-oxygenase [COX]-2 inhibitor)., Results: Among other observations, we found that the content of two metal (copper) binding protein species (2.9 and 3.2kDa) and three anionic protein species (4.0, 6.9 and 8.2kDa) were increased in the CSF of rats with inflammatory pain in a time-dependent fashion, at 7 and 14 days after CFA injection. These changes were highly selective for the CFA model, as no detectable increase in these protein biomarkers was found in the CCI neuropathic pain model. Further, we found that most of the changes in the biomarker protein species induced by the inflammatory pain were prevented by treatment with nimesulide and correlated with the antihyperalgesic effect of this drug., Conclusion: This study demonstrates that CSF biomarker profiles, as detected by SELDI technology, can consistently and reproducibly differentiate inflammatory from neuropathic pain, and reflect the analgesic action produced by the preferential COX-2 inhibitor, nimesulide. The characterisation and identification of these biomarkers will provide invaluable insight into the pathophysiology of pain mechanisms, in addition to further understanding of the value of nimesulide in the treatment of inflammatory pain.

We previously found that the cyclooxygenase (COX)-2 preferential inhibitor nimesulide protects rodents' chondrocytes against apoptotic death in vitro. In the present study, we found that nimesulide also reduces staurosporine-mediated apoptotic death in human chondrocytes in vitro. Using cDNA microarrays, we explored alterations in gene expression during human chondrocytic apoptosis, and the influence of nimesulide therapy on these changes. Based on their known biologic activities, candidate gene products with altered expression were assigned to clusters of biological functions and mechanisms, and analysed for specific sets of alterations. We found that the expression of genes involved in cell proliferation is differentially regulated during staurosporine-mediated apoptotic death in human chondrocytes. Treatment with nimesulide reversed the staurosporine-mediated effects on these gene products during protection against apoptosis. The study suggests that nimesulide, in addition to its analgesic effect, may confer chondroprotection through mechanisms beyond classical COX inhibition.

Background: Nonsteroidal anti-inflammatory drugs (NSAID) may be useful in the treatment of AD. Clinical and laboratory experience with nimesulide, an NSAID with preferential cyclooxygenase-2 inhibition, suggests that it may be a good candidate for AD therapy., Methods: This pilot study investigated the clinical feasibility of nimesulide treatment in AD. Forty persons with probable AD, most of whom were taking cholinesterase inhibitors, were enrolled in a randomized, controlled, parallel-group trial designed to assess tolerability and short-term cognitive/behavioral effects of nimesulide. In the initial 12-week double-blind phase, participants were treated with nimesulide 100 mg by mouth twice daily or matching placebo; during the second 12-week phase all participants received active drug. Participants who tolerated the drug well and perceived benefit were invited to continue open-label nimesulide treatment., Results: Short-term therapy with nimesulide, compared with placebo, had no significant effect on total assessment scores of measures of cognition, clinical status, activities of daily living, affect, and behavior. Long-term therapy was well tolerated for periods exceeding 2 years., Conclusion: These findings support the feasibility of nimesulide therapy in AD; assessment of efficacy will require a larger, long-term treatment study.

Alzheimer's disease (AD) is the most common form of dementia, affecting as many as 4 million older persons and results from abnormal changes in the brain that most likely begin long before cognitive impairment and other clinical symptoms become apparent. Thus, efforts aimed at identifying methods of early detection and diagnosis for improving AD care might be the most appropriate strategy to initiate promising new treatments and/or prevention. We used cDNA microarray technology to investigate the sequence of changes in gene expression in brain that may take place during the transition from normal cognitive functioning through the early stages of impairment to frank AD. We examined the expression of approximately 7,000 genes in the brains of cases at the early stage of AD dementia using reference sample cases characterized by normal cognitive status. Genes that are differentially regulated in early AD cases were identified and were categorized into gene clusters based on similarities in biological functions. This analysis revealed that selected biological processes, including protein and amino acid metabolism, cytoskeleton integrity, and fatty acid metabolism, are involved in early phases of AD dementia. Most notable is the observation that selected genes involved in neurotransmitter release are differentially regulated in the brains of cases at high risk for dementia. This evidence supports the feasibility and usefulness of cDNA microarray techniques to study sequential changes of distinctive gene-expression patterns in the brain as a function of the progression of AD dementia. The study suggests new means to dissect and classify stages of AD dementia, or neuropathology, at the molecular level., (Copyright 2001 Wiley-Liss, Inc.)

To provide a global analysis of the influence of Tau neuropathology at molecular level, we used cDNA arrays representing 8832 genes to determine the mRNA expression profile in transgenic mice expressing the most common frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) Tau mutation (P301L) (Nat. Genet. (2000) 402). Genes whose expression is associated with development of neurofibrillary tangles and neuron loss in P301L mice with motor and behavioral deficits were identified. The data suggest that a major mechanism underlying P301LTau neurodegeneration primarily involved altered expression of genes contributing to inhibition of apoptosis and intracellular transport. We propose that the expression of mutated P301L may lead to select altered expression of genes which may cause neurodegeneration in FTDP-17.

Industry and academia are devoting a tremendous amount of resources to the testing of anti-inflammatory drugs for the treatment of Alzheimer's disease (AD). This trend is the result of the growing consensus supporting the inflammatory hypothesis of AD. If anti-inflammatory strategies succeed in slowing the rate of disease progression, the impact on patients and families could be enormous. However, given the large number of candidates in the pool of anti-inflammatory drugs and given their widely divergent activities, it is essential to use methods which optimizes drug selection and study design. Pilot studies of anti-inflammatory regimens are useful in determining tolerability. However, these studies have limited value in estimating effective size since disease-modification, rather than symptomatic improvement, is the ultimate goal. Better understanding of the influence of inflammatory activity and the specific mechanisms which play an early role in the progression of the disease, will improve the likelihood of successfully identifying an effective anti-inflammatory treatment strategy. This review outlines directions in research that address possible contributions of cyclooxygenase (COX)-2, COX-1 and other inflammatory mediators to AD neurodegeneration. Finally, this article addresses potential interventions designed to control segments of classical inflammatory cascades in the brain in which cyclooxygenase is highly implicated. These considerations are critical to understand the role of cyclooxygenase in the clinical progression of AD.

We previously reported that pretreatment of murine cortico-hippocampal neuronal cultures with the complement-derived anaphylatoxin C5a, protects against glutamate neurotoxicity. In this study we explored the potential mechanisms involved in C5a-mediated neuroprotection. We found that C5a neuroprotects in vitro through inhibition of apoptotic death because pretreatment with human recombinant (hr)C5a prevented nuclear DNA fragmentation coincidental to inhibition of the pro-apoptotic caspase 3 activity mediated by glutamate treatment. Also, hrC5a-mediated responses appeared to be receptor-mediated because pretreatment of cultures with the specific C5a receptor antagonist C177, prevented hrC5a-mediated neuroprotection. Based on this evidence, we further explored possible signaling pathways involved in hrC5a inhibition of caspase 3 activation and apoptotic neuronal death. We found that treatment of cultures with the mitogen-activated protein kinase (MAPK) pathway inhibitor PD98059 prevented hrC5a-mediated inhibition of caspase 3 and apoptotic neuron death. MAPK pathways, whose activation by hrC5a is inhibited by PD98059 and C177, include the extracellular signal-regulated kinase (ERK)2 and, to a lesser extent, ERK1. The study suggests that C5a may protect against glutamate-induced apoptosis in neurons through MAPK-mediated regulation of caspase cascades.

Background: Prior studies have shown that cyclooxygenase 2 (COX-2), an enzyme involved in inflammatory mechanisms and neuronal activities, is up-regulated in the brain with Alzheimer disease (AD) and may represent a therapeutic target for anti-inflammatory treatments., Objective: To explore COX-2 expression in the brain as a function of clinical progression of early AD., Design and Main Outcome Measures: Using semiquantitative immunocytochemistry, we analyzed COX-2 protein content in the hippocampal formation in 54 postmortem brain specimens from patients with normal or impaired cognitive status., Setting and Patients: Postmortem study of nursing home residents., Results: The immunointensity of COX-2 signal in the CA3 and CA2 but not CA1 subdivisions of the pyramidal layers of the hippocampal formation of the AD brain increased as the disease progressed from questionable to mild clinical dementia as assessed by Clinical Dementia Rating. COX-2 signal was increased in all 3 regions examined among cases characterized by severe dementia., Conclusion: Neuronal COX-2 content in subsets of hippocampal pyramidal neurons may be an indicator of progression of dementia in early AD.

Using a cDNA microarray representing 6794 distinct human genes, we identified candidate genes whose expression is altered in cerebral cortex of cases of early Alzheimer's disease (AD); among these was the synaptic vesicle protein synapsin II, which plays an important role in neurotransmitter release. While other candidate genes are presently under investigation in our lab, in this study we discuss the regulation of synapsin gene expression during the transition from normal cognitive function to early AD. We found a selective decrease in the expression of the synapsin splice variants I-III of the a-type isoform in the entorhinal (EC, BM36) but not visual cortex (VC, BM17) of cases characterized by the earliest clinically detectable stage of AD. In contrast, we found no changes in synapsin splice variant II of the b-type isoform. Alteration of synapsin expression at the earliest clinical stage of AD may suggest novel strategies for improved treatment.

Alzheimer's disease (AD) is the most common form of dementia, affecting as many as four million elderly people. lt results from abnormal changes in the brain that most likely begin long before cognitive impairment and other clinical symptoms become apparent. Little is known about the changes preceding or accompanying initiation of the disease. Using cDNA microarray, we previously reported candidate gene products whose expression is altered in the cerebral cortex of cases at risk for AD dementia. However, it is possible that the cDNA microarray evidence might have underestimated post-transcriptional modifications, and as a result, provided only a partial view of the biological problem of interest. Based on this hypothesis, we initiated a series of parallel high-throughput proteomic studies. We found that, consistent with the cDNA microarray evidence, the expression of proteins involved in synaptic activities was also altered in the brains of early AD cases. These studies support the feasibility and usefulness of high-throughput cDNA and protein microarray techniques to examine the sequential changes of distinctive gene expression patterns in the brain as a function of the progression of AD dementia. Our preliminary results also support the utility of high-throughput proteomic methodologies as a means to identify novel AD biomarkers from cerebral spinal fluid and/or from serum.

Recent evidence suggests that the degradation of cartilage in osteoarthritis is characterized by chondrocyte apoptosis, but little is known about the molecular mechanisms involved or potential protective measures. In the present study, we used an immortalized chondrocyte cell line to explore the mechanisms of apoptotic chondrocyte cell death. We found that staurosporine-mediated chondrocyte death depended on the concentration and time of incubation, and coincided with increased Bax:Bcl-X mRNA expression, cytochrome C release, and activation of caspase-3. Pre-treatment of the cultures with nimesulide, a preferential cyclooxygenase (COX)-2 inhibitor, or with ibuprofen, a non-selective COX-1/COX-2 inhibitor, protected the chondrocytes against the staurosporine-mediated nuclear damage and cell death in a concentration-dependent manner (10(-12) to 10(-6) M). Cell protection coincided with inhibition of the staurosporine-mediated induction of caspase-3 activation. Notably, the selective COX-2 inhibitor NS-398 (10(-6) M, 24 hr pre-treatment) did not protect the cells against staurosporine-mediated apoptotic death. The data suggest that nimesulide and ibuprofen, in addition to their anti-inflammatory and analgesic benefits, may also have a protective effect in osteoarthritis through the inhibition of apoptosis in chondrocytes.

We assessed plasma neopterin level as a marker of inflammation in Alzheimer disease (AD). Plasma neopterin levels were higher in 51 patients with AD (9.3 +/- 5.9 ng/mL) than in 38 age-matched control subjects (6.3 +/- 2.6 ng/ml, p = 0.002). There was no correlation between neopterin levels and Mini-Mental State Examination score or duration of disease; there was a weak association between neopterin level and age (r = 0.26, p = 0.02). Although measurement of plasma neopterin levels is not useful for diagnosis, this assay may provide guidance for the development of anti-inflammatory treatment strategies for AD.

Background: Inflammatory cytokines have been linked to Alzheimer disease (AD) neurodegeneration, but little is known about the temporal control of their expression in relationship to clinical measurements of AD dementia progression., Design and Main Outcome Measures: We measured inflammatory cytokine messenger RNA (mRNA) expression in postmortem brain specimens of elderly subjects at different clinical stages of dementia and neuropathological dysfunction., Setting and Patients: Postmortem study of nursing home patients., Results: In brains of cognitively normal control subjects, higher interleukin 6 (IL-6) and transforming growth factor beta1 (TGF-beta1) mRNA expression was observed in the entorhinal cortex and superior temporal gyrus compared with the occipital cortex. Compared with age-matched controls, subjects with severe/terminal dementia, but not subjects at earlier disease stages, had higher IL-6 and TGF-beta1 mRNA expression in the entorhinal cortex (P<.01) and superior temporal gyrus (P<.01). When stratified by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropathological criteria, IL-6 mRNA expression in both the entorhinal cortex (P<.05) and superior temporal gyrus (P<.01) correlated with the level of neurofibrillary tangles but not neuritic plaques. However, in the entorhinal cortex, TGF-beta1 mRNA did not correlate with the level of either neurofibrillary tangles or neuritic plaques. Interestingly, in the superior temporal gyrus, TGF-beta1 mRNA expression negatively correlated with neurofibrillary tangles (P<.01) and showed no relationship to the pathological features of neuritic plaques., Conclusions: The data are consistent with the hypothesis that cytokine expression may differentially contribute to the vulnerability of independent cortical regions during the clinical progression of AD and suggest that an inflammatory cytokine response to the pathological effects of AD does not occur until the late stages of the disease. These findings have implications for the design of anti-inflammatory treatment strategies. Arch Neurol. 2000;57:1153-1160

There is evidence that the complement system, a major component of inflammatory responses, may play an important role in neurodegenerative conditions such as Alzheimer's disease (AD). Work from our lab demonstrated that mice genetically deficient in the complement component C5 are more susceptible to hippocampal excitotoxic lesions (Pasinetti et al., 1996) and that the C5-derived ana;hylatoxin C5a may protect against excitotoxicity in vitro and in vivo (Osaka et al., 1999). Potential mechanisms identified in C5a-mediated neuroprotection include activation of mitogen activated protein (MAP)-kinase (Osaka et al., 1998; Osaka et al., 1999). This novel neuroprotective role of C5a complicates current theories that complement proteins augment beta-amyloid (Abeta) toxicity in AD. In view of the fact that the complement system represents a target for therapeutic interventions in AD, further characterization of the complex role of complement proteins is essential. Towards this aim, we have characterized a transgenic C5a receptor (C5aR) knockout (KO) mouse. Recent studies in the lab using C5aR-KO mice show that disruption of C5aR alters calcium calmodulin kinase (CaM-KII) signal transduction in brain cells. We are presently using C5aR-KO mice to study the role of C5a in caspase mediated apoptotic neuronal death. In this review we will attempt to delineate possible neuroprotective roles for C5a in mechanisms of neurotoxicity pertaining to AD.

Inflammation clearly occurs in pathologically vulnerable regions of the Alzheimer's disease (AD) brain, and it does so with the full complexity of local peripheral inflammatory responses. In the periphery, degenerating tissue and the deposition of highly insoluble abnormal materials are classical stimulants of inflammation. Likewise, in the AD brain damaged neurons and neurites and highly insoluble amyloid beta peptide deposits and neurofibrillary tangles provide obvious stimuli for inflammation. Because these stimuli are discrete, microlocalized, and present from early preclinical to terminal stages of AD, local upregulation of complement, cytokines, acute phase reactants, and other inflammatory mediators is also discrete, microlocalized, and chronic. Cumulated over many years, direct and bystander damage from AD inflammatory mechanisms is likely to significantly exacerbate the very pathogenic processes that gave rise to it. Thus, animal models and clinical studies, although still in their infancy, strongly suggest that AD inflammation significantly contributes to AD pathogenesis. By better understanding AD inflammatory and immunoregulatory processes, it should be possible to develop anti-inflammatory approaches that may not cure AD but will likely help slow the progression or delay the onset of this devastating disorder.

Protein kinase C (PKC) has been implicated in the pathophysiology of Alzheimer's disease (AD). The levels of particular isoforms and the activation of PKC are reduced in postmortem brain cortex of AD subjects. Receptors for activated C kinase (RACK) are a family of proteins involved in anchoring activated PKCs to relevant subcellular compartments. Recent evidence has indicated that the impaired activation (translocation) of PKC in the aging brain is associated with a deficit in RACK1, the most well-characterized member of this family. The present study was conducted to determine whether alterations in RACK1 occurred in cortical areas where an impaired translocation of PKC has been demonstrated in AD. Here we report the presence of RACK1 immunoreactivity in human brain frontal cortex for the first time and demonstrate a decrease in RACK1 content in cytosol and membrane extracts in AD when compared with non-AD controls. By comparison, the levels of the RACK1-related PKCbetaII were not modified in the same membrane extracts. These observations add a new perspective in understanding the disease-associated defective PKC signal transduction and indicate that a decrease in an anchoring protein for PKC is an additional determinant of this deficit., (Copyright 1999 Academic Press.)

In this study we describe the generation of a transgenic mouse model with neuronal overexpression of the human cyclooxygenase-2, h(COX)-2, to explore its role in excitotoxicity. We report that overexpression of neuronal hCOX-2 potentiates the intensity and lethality of kainic acid excitotoxicity in coincidence with potentiation of expression of the immediate early genes c-fos and zif-268. In vitro studies extended the in vivo findings and revealed that glutamate excitotoxicity is potentiated in primary cortico-hippocampal neurons derived from hCOX-2 transgenic mice, possibly through potentiation of mitochondrial impairment. This study is the first to demonstrate a cause-effect relationship between neuronal COX-2 expression and excitotoxicity. This model system will allow the systematic examination of the role of COX-2 in mechanisms of neurodegeneration that involve excitatory amino acid pathways.

Cyclooxygenase-2 (COX-2), a key enzyme in prostanoid biosynthesis, may represent an important therapeutic target in Alzheimer's disease (AD). In the present study, we explored the regulation of COX-2 in the hippocampal formation in sporadic AD. Using semiquantitative immunocytochemical techniques, we found that in AD cases (vs. age-matched controls) neurons of the CA1-CA4 subdivisions of the hippocampal pyramidal layer showed elevation of COX-2 signal; COX-2 levels correlated with amyloid plaque density. In contrast, the level of COX-2 immunostaining in the dentate gyrus granule neurons was not elevated in AD. No expression of COX-2 in cells with glial morphology was found in any case examined. In parallel, in vitro studies found that neurons derived from transgenic mice with neuronal overexpression of COX-2 are more susceptible to beta-amyloid (Abeta) toxicity, with potentiation of redox impairment. The results indicate elevated expression of neuronal COX-2 in subregions of the hippocampal formation in AD and that such elevation may potentiate Abeta-mediated oxidative stress., (Copyright 1999 Wiley-Liss, Inc.)

Previous work from this laboratory indicates a role for the complement component C5 in neuroprotection against excitotoxicity. In the present study, we tested the hypothesis that the C5-derived anaphylatoxin C5a protects against kainic acid (KA)-induced neurodegeneration and investigated the mechanism of C5a neuronal activity in vitro. Brain intraventricular infusion of KA into adult mice caused neuronal morphological features of apoptosis in the pyramidal layer of the hippocampal formation as indicated by counts of neurons with pyknotic/condensed nuclei associated with cytoplasmic eosinophilia. Co-intraventricular infusion of human recombinant C5a with KA resulted in a marked reduction of morphological features of apoptotic neuronal death. In vitro studies confirmed C5a neuroprotection: treatment of primary murine corticohippocampal neurons with human or mouse recombinant C5a reduced glutamate neurotoxicity, as measured by trypan blue exclusion assay. This protection concurred with inhibition of glutamate-mediated induction of the caspase-3-related cysteine protease and coincided with marked reduction of neurons with morphological features of apoptosis, as found in vivo. Our studies indicate that C5a may inhibit glutamate-mediated neuronal death through partial inhibition of caspase-3 activity. These findings suggest a novel noninflammatory role for C5a in modulating neuronal responses to excitotoxins.

Prior studies indicated that glycoprotein 330 (gp330)/megalin mediates transcytosis of apolipoprotein J (apoJ) with Alzheimer's amyloide-peptide (Abeta) across the vascular membranes of the central nervous system (CNS). Here we show the presence of gp330/megalin mRNA and gp330-like immunoepitopes in brain capillaries and choroid plexus and their absence from brain parenchyma. By polymerase chain reaction (PCR) we estimated 1.2 x 10(5) molecules (1 pg) of gp330/megalin mRNA/microg total brain capillary RNA, which is 3% of that in kidney RNA. However, gp330 mRNA was not detected by in situ hybridization in vascular CNS tissue, presumably because of low transcript prevalence. The ratio of gp330 protein:RNA was 17-fold higher in choroid plexus vs brain capillaries, which implies tissue specific regulation of the protein and mRNA prevalence. We conclude that gp330/megalin mRNA and protein are expressed in brain capillaries and choroid plexus in small amounts that are consistent with the observed activities of this endocytosing receptor in the regulation of apoJ and Abeta uptake by the CNS., (Copyright 1999 Academic Press.)

The male rat striatum was examined for age-related changes in mRNAs expressed in astrocytes and microglia in two rat genotypes that differ by 35% in mean and maximum life spans: F344 and the longer-lived F1 (BN x F344) hybrid. The findings extend the established age-related increases in GFAP (glial fibrillary acidic protein) to other glial mRNAs: two lipoprotein mRNAs that are predominantly expressed in striatal astrocytes, apoE (apolipoprotein E) and apoJ (apolipoprotein J, clusterin, CLI, or SGP-2), and two mRNAs expressed in striatal microglia, TGF-beta1 and complement C1qB. By Northern blot hybridization, both genotypes showed progressive increases of GFAP mRNA to > 2.5-fold by the lifespan. Although the rat strains differed 35% in life span, the slope of the GFAP mRNA regression on age did not differ. Relative to GFAP, the increases of apoE, apoJ, C1q, and TGF-beta1 mRNAs were smaller, < or = 1.5-fold. Because prior studies showed that acute damage to striatal afferents induced astrocyte gene expression increases resembling those that also occur during aging, we examined long-term effects of damage to substantia nigra neurons on striatal astrocyte changes during aging. Young F344 rats were given 6-OHDA lesions that cause striatal dopamine deficits and induce GFAP. When examined 15 months later at age 18 months, there was no effect during prior lesions on the age-related elevation of GFAP mRNA. We conclude that aging changes in striatal GFAP mRNAs do not interact with loss of dopaminergic output to the striatum from 6-OHDA lesions and may be independent of the relatively modest dopaminergic losses during normal aging.

In this study we explored the potential role of the complement derived anaphylatoxin C5a and the expression of its receptor in mouse brain. Using in situ hybridization, we found that C5a receptor messenger RNA is expressed in mouse brain. In response to intraventricular kainic acid injection, there was marked increase in the C5a receptor messenger RNA expression, particularly in hippocampal formation and cerebral cortex. C5a ligand-binding autoradiography confirmed the functional expression and elevation of the C5a receptor post-lesioning. The expression of C5a receptor messenger RNA in brain was confirmed by northern blot hybridization of total RNA from neuronal and glial cells in vitro. Based on these findings we explored the role of C5a in mechanisms of signal transduction in brain cells. Treatment of primary cultures of mouse astrocytes with human recombinant C5a resulted in the activation of mitogen-activated extracellular signal-regulated protein kinase. This response appeared to be mediated by the C5a receptor since astrocyte cultures derived from C5a receptor knockout mice were not responsive to the treatment. Understanding the regulation of C5a receptor in brain and mechanisms by which pro-inflammatory C5a modulates specific signal transduction pathways in brain cells is crucial to studies of inflammatory mechanisms in neurodegeneration.

The importance of inflammatory/immune mechanisms in Alzheimer's disease is supported by evidence that the human leukocyte antigen (HLA)-DR genotype influences risk of the disease, with a protective effect associated with the HLA-DR4 allele. We investigated the influence of the HLA-DR4 allele on glial activity, assessed by quantification of glial fibrillary acidic protein (GFAP), in hippocampal tissue from subjects with Alzheimer's disease. The mean GFAP level was significantly higher in Alzheimer's disease hippocampal specimens lacking the HLA-DR4 allele compared to specimens with similar neuropathological findings that were HLA-DR4 positive. Apolipoprotein E genotype had no influence on GFAP levels. These results indicate that HLA-DR4 may exert a protective influence on Alzheimer's disease via modulation of glial activity.

Many epidemiological studies suggest that use of nonsteroidal anti-inflammatory drugs delays or slows the clinical expression of Alzheimer's disease, but the mechanism by which these drugs might affect pathophysiological processes relevant to Alzheimer's disease has been unclear. Non-steroidal anti-inflammatory drugs are presumed to act by inhibiting cyclooxygenase, a key enzyme in the metabolism of membrane-derived arachidonic acid into prostaglandins. In recent years, two distinct isoforms of cyclooxygenase have been characterized, a constitutive form, cyclooxygenase-1, and a mitogen-inducible form, cyclooxygenase-2. Cyclooxygenase-2 has been identified in rodent brain. Excitotoxic lesions cause up-regulation of cyclooxygenase-2 expression coincident with the onset of expression of markers of apoptosis; cyclooxygenase-2 thus represents a possible target of non-steroidal anti-inflammatory drug action in neurodegenerative mechanisms. In the present study, we examined cyclooxygenase-2 gene expression in Alzheimer's disease and control cases. We found up-regulation of cyclooxygenase-2 expression in Alzheimer's disease frontal cortex. Further, we found that synthetic beta-amyloid peptides induced cyclooxygenase-2 expression in SH-SY5Y neuroblastoma cells in vitro, suggesting a mechanism for cyclooxygenase-2 up-regulation in Alzheimer's disease. These findings support the investigation of selective cyclooxygenase-2 inhibitors for the treatment of Alzheimer's disease.

Many epidemiological studies suggest that use of non-steroidal anti-inflammatory drugs (NSAIDs) delay or slow the clinical expression of Alzheimer's disease (AD). While it has been demonstrated that neurodegeneration in AD is accompanied by specific inflammatory mechanisms, including activation of the complement cascade and the accumulation and activation of microglia, the mechanism by which NSAIDs might affect these or other pathophysiological processes relevant to AD has been unclear. New evidence that cyclooxygenase (COX) is involved in neurodegeneration along with the development of selective COX inhibitors has led to renewed interest in the therapeutic potential of NSAIDs in AD.

In this study we assessed the regulation of cyclooxygenase (COX)-2 in models of apoptotic cell death in vivo and in vitro. By 6 h after hippocampal colchicine injection in rat, COX-2 (but not COX-1) mRNA expression was elevated. The induction of COX-2 mRNA expression preceded temporally and overlapped anatomically the cellular morphological features of apoptosis in the granule cell layer of the dentate gyrus. Similarly, in an established in vitro model of apoptosis in P19 cells, COX-2 induction preceded apoptosis in response to serum deprivation by 12 h. These studies suggest that COX-2 may be involved in the early mechanisms leading to apoptosis.

Imaging investigations and other findings observed in a term infant with a multicentric hepatic hemangioendothelioma, admitted to the Intensive Care Unit at the age of 13 days because of non specified feeding difficulties and dyspnoea, are presented. Physical examination revealed cardiac bruit and congestive heart failure with marked hepatomegaly; in addition there were multiple small skin hemangiomas. Echocardiography was negative, abdominal sonography showed multiple round lesions of mixed echogenicity in the liver, large vascular channels, a right hepatic artery and hepatic veins enlarged, a caliber of the aorta below the level of the superior mesenteric artery reduced. The infant was additionally investigated by whole-body scintigraphy with 99mTc-labeled red blood cells to determine the possibility of coexistence of other visceral hemangiomas and by MR, in which the tumor manifested as multiple well-circumscribed space-occupying nodules of high signal intensity on T2-weighted images with evidence of fast flow. The baby underwent furosemide and steroid therapy: serial two-dimensional US scans showed change in echogenicity, responding to therapy. Doppler sonography has proven to be also very useful in the monitoring therapy determining changes in flow pattern and velocity at the level of hepatic, cerebral and renal vessels: before therapy we observed a reduction of the diastolic flow until the zero line through the internal carotid artery and renal artery with an increase of the Resistance Index. It means that this important component can be compromised in the presence of a hepatic hemangioendothelioma.

The inflammatory hypothesis of Alzheimer's disease states that specific inflammatory mechanisms, including the cytokine-driven acute-phase response, complement activation and microglial activation, contribute to neurodegeneration. If the hypothesis is correct, anti-inflammatory treatment aimed at suppression of these mechanisms could slow the rate of disease progression. Towards this goal, a multicentre trial of prednisone in Alzheimer's disease is under way and pilot studies of other anti-inflammatory regimens are being conducted.

Using mice genetically deficient in the complement (C)-system component C5, this study explored a potential novel role of the C-system in Ca(2+)-mediated control of glutamate AMPA receptor functions. We found that Ca2+ preincubation of frozen brain tissue sections enhances AMPA binding capacity more dynamically in C5 deficient (C5-) than congenic C5 sufficient (C5+) mice. The Ca(2+)-mediated response was mostly localized to the CA3 and CA1 subdivisions of the pyramidal layers of the hippocampal formation. In C5- mice, kainic acid (KA) excitotoxicity that models hippocampal neurodegeneration abolished the Ca(2+)-mediated induction of hippocampal AMPA binding. The changes in AMPA binding preceded temporally and overlapped anatomically the appearance of apoptotic features in the same hippocampal neuron layers. C5- mice showed greater hippocampal neurodegeneration then C5+ mice. NMDA binding controlled for specificity of glutamate-mediated changes and found no C5 genotypic influences. The study gives further credence to the role of the C-system in modifying the intensity and outcome during response to conditions leading to hippocampal neurodegeneration.

We explored the constitutive expression, maturational regulation, and relation to kainic-acid-induced apoptosis of cyclooxygenase (COX)-2 mRNA in rat brain. In adult rats, COX-2 mRNA was expressed primarily in limbic structures. Constitutive COX-2 mRNA expression increased markedly between Postnatal Day 7 (P7) and P14, reaching adult levels by P21. Despite intense KA-induced seizures, no COX-2 mRNA induction was found before P14 in any brain region examined. During response to KA-induced seizures in adult brain, COX-2 mRNA induction paralleled temporally and overlapped anatomically the appearance of cellular morphological features of apoptosis in subsets of cells of the pyramidal neuron layer of the hippocampal formation, amygdaloid complex, and pyriform cortex. While COX-2 mRNA showed KA-induced elevation in the granule cell layer of the dentate gyrus, no detectable morphological features of apoptosis were found in this region. Finally, monotypic culture of rat corticohippocampal neurons confirmed the neuronal expression of COX-2 in vitro and revealed that COX-2 is induced during response to glutamate treatment, leading to neuron death. These studies may provide novel insights into the role of COX-2 and mechanisms of action of nonsteroidal anti-inflammatory drugs in Alzheimer's disease.

This review discusses key findings indicating potential roles of the complement (C)-system in chronic inflammation in Alzheimer's disease (AD) brain. Although there is no means to cure or prevent the disease, recent studies suggest that antiinflammatory drugs may delay the onset of AD dementia. One target of these drugs may be the (C)-system, which is best known for its roles in inflammatory processes in peripheral tissues. However, recent data show C-system expression and regulation in brain cells, and C-system protein deposition in AD plaques. It is still nuclear whether C-system activation contributes to neuropathology in the AD brain, as shown in multiple sclerosis (MS). New clinical studies with antiinflammatory agents are now under general consideration by the Alzheimer's Disease Cooperative Study program. In this review I outline research directions which address possible C-system contributions to neurodegeneration. Finally, I discuss potential pharmacological interventions designed to control segments of classical inflammatory cascades in which the C-system is highly implicated. These aspects are critical to the understanding of C-mediated responses in normal and pathologic brain.

This study explored the role of clusterin in mechanisms of cell adhesion and apoptosis in P19 embryonic carcinoma cells. We found that serum deprivation induced transient but dramatic elevation in cell adhesion strength to the culture substrate and eventually led to apoptotic cell death. The time course of cell-adhesion increase overlapped temporally with the elevation of clusterin mRNA (peak 8 h after serum deprivation). The coincidental elevation of clusterin expression and cell adhesion strength preceded the schedule of apoptotic cell death. Clusterin antiserum partially antagonized cell adhesion, but did not modify the course of apoptosis. These data suggest that clusterin expression may partially control cell adhesion with no influence on apoptosis in P19 cells, under defined conditions.

Possible roles of the complement (C) system in the normal and injured brain were explored with inbred mice that carried a frameshift mutation in the C5 gene. A congenic pair was used: the C5-sufficient (C5+) B10.D2/nSnJ strain with the functional allele (Hc1) from the C57BL/10J donor strain was compared with the C5-deficient (C5-) B10.D2/oSnJ with the Hc0 allele from the C5-deficient DBA/2J donor strain. In response to the excitotoxin kainic acid (KA), C5- mice had more hippocampal pyramidal neuron death and greater induction of astrocyte mRNAs (GFAP, apoE, apoJ). In primary astrocyte cultures from unlesioned mice, an inflammatory stimulus (LPS) caused greater production of IL-6 and TNF production in C5- mice. These enhanced responses to KA and LPS suggest that hereditary C5 deficits modify responses to neurodegenerative stimuli of neurons and astrocytes. Moreover, unlesioned C5- mice had smaller input-output slopes for the NMDA component of the EPSP amplitude, but enhanced the Ca(+2)-dependent AMPA binding. Thus, C5 deficits also modify basal properties of glutamatergic neurotransmission that pertain to synaptic plasticity. These findings are also discussed in relation to roles of the C-system in Alzheimer disease (AD). C5 deficiencies may also be considered in the choice of strains as transgene hosts and for genetic analysis of normal and pathological brain functions. In recent transgenic studies for AD, C5- hosts showed greater neurodegeneration, consistent with the present data. These pleiotropic associations of C5 deficiency indicate roles for the C-system in neurodegeneration, but also in normal neural functions.