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Marsel Mesulam

Publications and source records attributed to Marsel Mesulam.

10 recordsLinked to original sources
PubMed2011

Common variants at MS4A4/MS4A6E, CD2AP, CD33 and EPHA1 are associated with late-onset Alzheimer's disease.

The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study of late-onset Alzheimer disease using a three-stage design consisting of a discovery stage (stage 1) and two replication stages (stages 2 and 3). Both joint analysis and meta-analysis approaches were used. We obtained genome-wide significant results at MS4A4A (rs4938933; stages 1 and 2, meta-analysis P (P(M)) = 1.7 × 10(-9), joint analysis P (P(J)) = 1.7 × 10(-9); stages 1, 2 and 3, P(M) = 8.2 × 10(-12)), CD2AP (rs9349407; stages 1, 2 and 3, P(M) = 8.6 × 10(-9)), EPHA1 (rs11767557; stages 1, 2 and 3, P(M) = 6.0 × 10(-10)) and CD33 (rs3865444; stages 1, 2 and 3, P(M) = 1.6 × 10(-9)). We also replicated previous associations at CR1 (rs6701713; P(M) = 4.6 × 10(-10), P(J) = 5.2 × 10(-11)), CLU (rs1532278; P(M) = 8.3 × 10(-8), P(J) = 1.9 × 10(-8)), BIN1 (rs7561528; P(M) = 4.0 × 10(-14), P(J) = 5.2 × 10(-14)) and PICALM (rs561655; P(M) = 7.0 × 10(-11), P(J) = 1.0 × 10(-10)), but not at EXOC3L2, to late-onset Alzheimer's disease susceptibility.

Adaptor Proteins, Signal Transducing↗
PubMed2007

Progranulin mutations in primary progressive aphasia: the PPA1 and PPA3 families.

BACKGROUND: Primary progressive aphasia (PPA) is a language-based dementia characterized by fluent or nonfluent language disorder as its principal feature. OBJECTIVE: To describe progranulin gene mutations in 2 families with PPA. DESIGN: Report of affected families. SETTING: Academic research. PATIENTS: Two families, PPA1 and PPA3, were studied. Genomic DNA was isolated from 3 of 4 siblings in PPA1, from all 3 siblings in PPA3, and from more than 200 control subjects. MAIN OUTCOME MEASURES: All 12 coding exons of the progranulin gene and the 5" and 3" untranslated regions were amplified by polymerase chain reaction and were sequenced in both directions using relevant primers. RESULTS: Both affected members of PPA1 for whom DNA was available and both affected sisters of PPA3 had a progranulin gene mutation not found in the unaffected siblings or in the controls. The mutations likely cause a null allele and a reduction in the level of functional progranulin protein. Both affected members of PPA1 with autopsies had frontotemporal lobar degeneration with tau-negative ubiquinated inclusions. CONCLUSIONS: To our knowledge, these are the only known families in which affected members display phenotypical homogeneity for PPA in the initial stages of the disease. In both families, the disease segregated with progranulin gene mutations. Whether progranulin dysfunction also extends to sporadic PPA and how it affects the initial anatomical specificity of neurodegeneration remain to be determined.

Aged↗
PubMed2006

Mutations in progranulin are a major cause of ubiquitin-positive frontotemporal lobar degeneration.

Null mutations in the progranulin gene (PGRN) were recently reported to cause tau-negative frontotemporal dementia linked to chromosome 17. We assessed the genetic contribution of PGRN mutations in an extended population of patients with frontotemporal lobar degeneration (FTLD) (N=378). Mutations were identified in 10% of the total FTLD population and 23% of patients with a positive family history. This mutation frequency dropped to 5% when analysis was restricted to an unbiased FTLD subpopulation (N=167) derived from patients referred to Alzheimer's Disease Research Centers (ADRC). Among the ADRC patients, PGRN mutations were equally frequent as mutations in the tau gene (MAPT). We identified 23 different pathogenic PGRN mutations, including a total of 21 nonsense, frameshift and splice-site mutations that cause premature termination of the coding sequence and degradation of the mutant RNA by nonsense-mediated decay. We also observed an unusual splice-site mutation in the exon 1 5' splice site, which leads to loss of the Kozac sequence, and a missense mutation in the hydrophobic core of the PGRN signal peptide. Both mutations revealed novel mechanisms that result in loss of functional PGRN. One mutation, c.1477C>T (p.Arg493X), was detected in eight independently ascertained familial FTLD patients who were shown to share a common extended haplotype over the PGRN genomic region. Clinical examination of patients with PGRN mutations revealed highly variable onset ages with language dysfunction as a common presenting symptom. Neuropathological examination showed FTLD with ubiquitin-positive cytoplasmic and intranuclear inclusions in all PGRN mutation carriers.

Adult↗
PubMed2004

Left hemicranial hypoplasia in 2 patients with primary progressive aphasia.

BACKGROUND: Primary progressive aphasia (PPA) leads to a gradual and relatively isolated dissolution of language function. The factors that determine the selectivity of the disease process remain unknown. We had speculated that PPA may occasionally arise as a tardive manifestation of genetic or acquired vulnerabilities involving the language network of the brain. OBJECTIVE: To explore predisposing factors for PPA. RESULTS: In 2 patients, PPA developed with a background of mild left hemicranial hypoplasia. CONCLUSION: In keeping with other observations of PPA in patients with dyslexia and childhood injury to the left temporal lobe, these 2 patients support the contention that some cases of PPA may arise in settings where the language network has become a locus of least resistance.

Activities of Daily Living↗
PubMed2004

Cholinergic nucleus basalis tauopathy emerges early in the aging-MCI-AD continuum.

The cholinergic denervation in Alzheimer's disease (AD) provides the rationale for treatments with anticholinesterases. The presence of this cholinergic lesion is solidly established in advanced AD. Whether it also exists in early disease remains unsettled. This question was addressed with thioflavin-S histofluorescence to identify neurofibrillary tangles (NFT) and two tau antibodies (AT8, Alz-50) to identify pre-tangle cytopathology in the nucleus basalis, the source of cortical cholinergic innervation. Methods for the concurrent visualization of tauopathy and choline acetyltransferase were used to determine if the cytopathology was selectively located within cholinergic neurons. Five elderly index cases who had died at the stage of mild cognitive impairment (MCI) or early AD were identified by longitudinal neuropsychological and behavioral assessments. They were compared to 7 age-matched cognitively normal subjects. NFT and AT8 (or Alz-50) immunostaining in cholinergic nucleus basalis neurons existed even in the cognitively normal subjects. The percentage of tauopathy-containing nucleus basalis neurons was greater in the cognitively impaired and showed a significant correlation with memory scores obtained 1-18 months prior to death. These results show that cytopathology in cortical cholinergic pathways is a very early event in the course of the continuum that leads from advanced age to MCI and AD.

Acetylcholine↗
PubMed2003

Cholinergic denervation in a pure multi-infarct state: observations on CADASIL.

Circumstantial evidence suggests that vascular dementia (VaD) may be associated with cholinergic denervation. The specificity of this association has been difficult to assess because many of the patients are elderly and have the additional cholinergic lesions of aging and AD. A patient with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) who died at age 36 showed that pure white matter infarcts, similar to those seen in VaD, can cause cortical cholinergic denervation, but in patterns that vary from those seen in AD.

Acetylcholinesterase↗
PubMed2002

Widely spread butyrylcholinesterase can hydrolyze acetylcholine in the normal and Alzheimer brain.

BACKGROUND: Butyrylcholinesterase (BChE), also known as the "pseudo" or "non-neuronal" cholinesterase, is traditionally thought to have a restricted CNS distribution and to play little, if any, role in cholinergic transmission. OBJECTIVE: To reanalyze the role of BChE in the human brain with more sensitive methodology. METHODS: Three brains were examined with acetylcholinesterase and BChE histochemistry. The sections were examined with bright- and dark-field microscopy. RESULTS: The histochemical parameters used in the present experiments showed that BChE activity was present in all hippocampal and temporal neocortical areas known to receive cholinergic input. At all of these locations, the BChE enzyme could hydrolyze the acetylcholine surrogate acetylthiocholine. A substantial portion of the hippocampal and neocortical BChE appeared to be located within neuroglia and their processes. CONCLUSIONS: Butyrylcholinesterase may have a greater role in cholinergic transmission than previously surmised, making BChE inhibition an important therapeutic goal in Alzheimer's disease. The results also suggest that the role of neuroglia in cholinergic transmission may be analogous to their well known role in glutamatergic transmission.

Acetylcholine↗
PubMedDate not supplied

The cholinergic lesion of Alzheimer's disease: pivotal factor or side show?

A profound loss of cortical cholinergic innervation is a nearly invariant feature of advanced Alzheimer's disease (AD). The temporal course of this lesion and its relationship to other aspects of the disease have not yet been fully clarified. Despite assertions to the contrary, a review of the evidence suggests that a perturbation of cholinergic innervation is likely to be present even in the very early stages of AD. This cholinergic lesion is unlikely to be a major determinant of the clinical symptoms or of the neuropathological lesions. Nonetheless, it almost certainly contributes to the severity of the cognitive and behavioral deficits, especially in the areas of memory and attention. The cholinergic lesion may also influence the progression of the neuropathological process through complex interactions with amyloidogenesis, tau phosphorylation and neuroplasticity.

Acetylcholine↗