RESUMEN
In this study, we characterise the binding site of the human N-methyl-d-aspartate (NMDA) receptor subunit NR3A. Saturation radioligand binding of the NMDA receptor agonists [(3)H]-glycine and [(3)H]-glutamate showed that only glycine binds to human NR3A (hNR3A) with high affinity (K(d)=535nM (277-793nM)). Eight amino acids, which correspond to amino acids that are critical for ligand binding to other NMDA receptor subunits, situated within the S1S2 predicted ligand binding domain of hNR3A were mutated, which resulted in complete or near complete loss of [(3)H]-glycine binding to hNR3A. The NMDA NR1 glycine site agonist d-serine and partial agonist HA-966 (3-amino-1-hydroxypyrrolid-2-one), similarly to glycine displaced [(3)H]-glycine monophasically, suggesting a single common binding site. However, neither the partial agonist d-cycloserine nor the antagonist 7-chlorokynurenic acid displaced [(3)H]-glycine. Using homology modelling, a model of the NR3A binding pocket was generated which we suggest can be used to identify candidate agonists and antagonists. Our data show that glycine is a ligand, and most probably the endogenous ligand, for native NR3A at a binding site with unique pharmacological characteristics.
Asunto(s)
Unión Competitiva/efectos de los fármacos , Glicina/metabolismo , Receptores de N-Metil-D-Aspartato/fisiología , Animales , Encéfalo/efectos de los fármacos , Línea Celular Transformada , Cicloserina/farmacología , Relación Dosis-Respuesta a Droga , Antagonistas de Aminoácidos Excitadores/farmacología , Glicina/agonistas , Glicina/antagonistas & inhibidores , Humanos , Ácido Quinurénico/análogos & derivados , Ácido Quinurénico/farmacología , Modelos Moleculares , Mutación/fisiología , Unión Proteica/efectos de los fármacos , Ratas , Receptores de N-Metil-D-Aspartato/química , Receptores de N-Metil-D-Aspartato/efectos de los fármacos , TransfecciónRESUMEN
beta-amyloid (Abeta) is the main constituent of senile plaques seen in Alzheimer's disease. Abeta is derived from the amyloid precursor protein (APP) via proteolytic cleavage by proteases beta- and gamma-secretase. In this study, we examined content and localization of beta-secretase-cleaved APP (beta-sAPP) in brain tissue sections from the frontal, temporal and occipital lobe. Strong granular beta-sAPP staining was found throughout the gray matter of all three areas, while white matter staining was considerably weaker. beta-sAPP was found to be localized in astrocytes and in axons. We found the beta-sAPP immunostaining to be stronger and more extensive in gray matter in Alzheimer disease (AD) cases than controls. The axonal beta-sAPP staining was patchy and unevenly distributed for the AD cases, indicating impaired axonal transport. beta-sAPP was also found surrounding senile plaques and cerebral blood vessels. The results presented here show altered beta-sAPP staining in the AD brain, suggestive of abnormal processing and transport of APP.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Encéfalo/patología , Secretasas de la Proteína Precursora del Amiloide , Astrocitos/metabolismo , Axones/metabolismo , Endopeptidasas , Humanos , Inmunohistoquímica , Microscopía FluorescenteRESUMEN
Alzheimer's disease (AD) is characterized by the degeneration and loss of neurons, intracellular neurofibrillary tangles and the accumulation of extracellular senile plaques consisting mainly of beta-amyloid (A beta). A beta is generated from the amyloid precursor protein (APP) by sequential beta- and gamma-secretase cleavage. Alternatively, APP may be cleaved within the A beta region by alpha-secretase, preventing A beta formation. Here we investigated APP processing and secretion in primary neurons, using either colchicine or the calcium ionophore A23187 to induce apoptosis. Cell viability was determined by MTT measurements and apoptosis was further confirmed by annexin V and propidium iodide staining. We found that exposure to A23187 significantly decreased the secretion of soluble beta-secretase cleaved APP (beta-sAPP) in a caspase-dependent manner, although the secretion of total soluble APP beta sAPP) did not change. In addition, caspase inhibition restored cell viability to control levels. Exposure to colchicine did not change the amount of either secreted beta-sAPP or total sAPP and caspase inhibition was only partially able to restore cell viability. We conclude that calcium homeostasis is an important apoptotic effector specifically affecting the beta-secretase cleavage of APP.
Asunto(s)
Precursor de Proteína beta-Amiloide/metabolismo , Apoptosis/efectos de los fármacos , Calcimicina/farmacología , Calcio/fisiología , Corteza Cerebral/citología , Ionóforos/farmacología , Neuronas/efectos de los fármacos , Clorometilcetonas de Aminoácidos/farmacología , Secretasas de la Proteína Precursora del Amiloide , Animales , Anexina A5/análisis , Apoptosis/fisiología , Ácido Aspártico Endopeptidasas/metabolismo , Transporte Biológico/efectos de los fármacos , Western Blotting , Células Cultivadas/efectos de los fármacos , Células Cultivadas/metabolismo , Corteza Cerebral/embriología , Colchicina/farmacología , Medios de Cultivo Condicionados/análisis , Inhibidores de Cisteína Proteinasa/farmacología , Citoesqueleto/efectos de los fármacos , Endopeptidasas , Neuronas/enzimología , Neuronas/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region of the hippocampus. Multiple isoforms are transiently activated in the induction phase of long-term potentiation (LTP). In contrast, a single species, zeta, is persistently activated during the maintenance phase of LTP through the formation of an independent, constitutively active catalytic domain, protein kinase Mzeta (PKMzeta). In this study, we used immunoblot and immunocytochemical techniques with isoform-specific antisera to examine the distribution of the complete family of PKC isozymes and PKMzeta in rat brain. Each form of PKC showed a widespread distribution in the brain with a distinct regional pattern of high and low levels of expression. PKMzeta, the predominant form of PKM in brain, had high levels in hippocampus, frontal and occipital cortex, striatum, and hypothalamus. In the hippocampus, each isoform was expressed in a characteristic pattern, with zeta prominent in the CA1 stratum radiatum. These results suggest that the compartmentalization of PKC isoforms in neurons may contribute to their function, with the location of PKMzeta prominent in areas notable for long-term synaptic plasticity.
Asunto(s)
Encéfalo/enzimología , Proteína Quinasa C/metabolismo , Ratas/metabolismo , Animales , Cerebelo/enzimología , Hipocampo/enzimología , Immunoblotting , Inmunohistoquímica , Isoenzimas/metabolismo , Ratas Sprague-Dawley , Distribución TisularAsunto(s)
ADN Mitocondrial/genética , Variación Genética , Haplotipos , Humanos , Islandia , Polimorfismo GenéticoRESUMEN
Mutations in the presenilin-1 (PS1) and presenilin-2 (PS2) genes account for the majority of early-onset familial Alzheimer's disease cases. Recent studies suggest that presenilin gene mutations predispose cells to apoptosis by mechanisms involving altered calcium homeostasis and oxidative damage. In the present study, we determined whether PS1 mutations also sensitize cells to hyperosmotic stress-induced apoptosis. For this, we established SH-SY5Y neuroblastoma cell lines stably transfected with wild-type PS1 or either the PS1 exon 9 deletion (deltaE9) or PS1 L250S mutants. Cultured cells were exposed to an overnight (17 h) serum deprivation, followed by a 30 min treatment with either 20 mM glucose, 10 nM insulin-like growth factor-1 or 20 mM glucose + 10 nM insulin-like growth factor-1. Cells were then cultured for a further 3, 6 or 24 h and stained for apoptotic condensed nuclei using propidium iodide. Confirmation that cells were undergoing an active apoptotic process was achieved by labelling of DNA strand breaks using the terminal dUTP nick end labelling (TUNEL) technique. We also determined cell viability using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Propidium iodide staining revealed that all cell lines and controls showed an increased number of apoptotic cells appearing with condensed nuclei at 24 h compared with 6 h and 3 h. High glucose-induced hyperosmotic stress resulted in significantly more apoptotic cells in the PS1 deltaE9 and PS1 L250S mutation cell lines at 24 h, compared with the wild-type PS1 lines (P < 0.001, ANOVA for both comparisons). Mean values (+/-S.D.) for the percentage number of apoptotic cells at 24 h following high glucose treatment were 16.1 +/- 3.5%, 26.7 +/- 5.5% and 31.0 +/- 5.7% for the wild-type PS1, PS1 deltaE9 and PS1 L250S lines, respectively. The pro-apoptotic effects of high glucose treatment were reversed by 10 nM insulin-like growth factor-1, although to a lesser extent in the mutation cell lines (5.8 +/- 2.4%, 15.2 +/- 7.3% and 13.2 +/- 2.0% for the wild-type PS1, PS1 deltaE9 (P < 0.01 for comparison with wild-type PS1) and PS1 L250S (P < 0.01 for comparison with wild-type PS1) transfected lines, respectively. TUNEL labelling of cells at 24 h following treatment gave essentially the same results pattern as obtained using propidium iodide. The percentage number of apoptotic cells with DNA strand breaks (means +/- S.D.) following high glucose treatment was 15.4 +/- 2.6% for the wild-type PS1, 26.8 +/- 3.2% for the PS1 deltaE9 (P < 0.001 for comparison with wild-type PS1) and 29.7 +/- 6.1% for the PS1 L250S transfected lines (P < 0.001 for comparison with wild-type PS1). The PS1 deltaE9 and PS1 L250S transfected lines also showed a higher number of apoptotic cells with DNA strand breaks at 24 h following high glucose plus insulin-like growth factor-1 treatment (11.4 +/- 2.0% and 14.3 +/- 2.8%, respectively), compared with values for the wild-type PS1 lines (8.5 +/- 2.4%). These differences were significant (P < 0.01) for the comparison of wild-type PS1 and PS1 L250S, but not PS1 deltaE9 lines. The mutation-related increases in number of apoptotic cells at 24 h following high glucose treatment were not accompanied by significant differences in cell viability at this time-point. Our results indicate that PS1 mutations predispose to hyperosmotic stress-induced apoptosis and that the anti-apoptotic effects of insulin-like growth factor-1 are compromised by these mutations. Perturbations of insulin-like growth factor-1 signalling may be involved in PS1 mutation-related apoptotic neuronal cell death in Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer/genética , Apoptosis/genética , Eliminación de Gen , Proteínas de la Membrana/genética , Enfermedad de Alzheimer/patología , Neoplasias Encefálicas , Movimiento Celular/fisiología , Colorantes , Glucosa/metabolismo , Humanos , Soluciones Hipertónicas , Etiquetado Corte-Fin in Situ , Factor I del Crecimiento Similar a la Insulina/metabolismo , Mutación , Neuritas/fisiología , Neuroblastoma , Presión Osmótica , Presenilina-1 , Transducción de Señal/fisiología , Sales de Tetrazolio , Tiazoles , Transfección , Células Tumorales Cultivadas/citología , Células Tumorales Cultivadas/metabolismoRESUMEN
Alternative cleavage of the amyloid precursor protein (APP) results in generation and secretion of both soluble APP (sAPP) and beta-amyloid (Abeta). Abeta is the main component of the amyloid depositions in the brains of Alzheimer's disease (AD) patients. Using Western blotting, we compared the levels of alpha-secretase cleaved sAPP, beta-secretase cleaved sAPP and total sAPP, in cerebrospinal fluid (CSF) from 13 sporadic AD patients and 13 healthy controls. Our findings show significant amounts of beta-secretase cleaved sAPP in CSF. There was no statistically significant difference in the levels of beta-secretase cleaved sAPP between AD patients and controls. The levels of alpha-secretase cleaved sAPP and total sAPP were, however, found to be significantly lower in the AD patients than in the controls.
Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Precursor de Proteína beta-Amiloide/líquido cefalorraquídeo , Precursor de Proteína beta-Amiloide/química , Ácido Aspártico Endopeptidasas/metabolismo , Endopeptidasas/metabolismo , Anciano , Secretasas de la Proteína Precursora del Amiloide , Western Blotting , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de ReferenciaRESUMEN
Tau proteins are central to the neuropathology of Alzheimer's disease and tau levels in cerebrospinal fluid are elevated in affected individuals. In this study, we investigated the presence of tau in plasma from subjects with Alzheimer's disease (n = 16), frontotemporal dementia (n = 10), vascular dementia (n = 16) and from healthy controls (n = 15). By using an ELISA with monoclonal tau antibodies, tau immunoreactivity was detected in approximately 20% of the subjects. However, no difference between the disease and control groups was seen. After gel filtration of tau immunopositive plasma, the peak reactivity was found in the 160-kD fraction, indicating the source to be tau-like molecules of high-molecular-weight or polymers of low-molecular-weight tau isoforms. We conclude that measurements of tau in plasma cannot be utilized diagnostically for Alzheimer's disease or for the other dementias investigated. Copyrightz1999S.KargerAG,Basel
Asunto(s)
Demencia/sangre , Proteínas tau/sangre , Anciano , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/patología , Apolipoproteínas E/genética , Cromatografía en Gel , Demencia/líquido cefalorraquídeo , Demencia/patología , Demencia Vascular/sangre , Demencia Vascular/líquido cefalorraquídeo , Demencia Vascular/patología , Ensayo de Inmunoadsorción Enzimática , Femenino , Lóbulo Frontal/patología , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Temporal/patología , Proteínas tau/líquido cefalorraquídeoRESUMEN
An important gap in our understanding of the pathogenesis of the amyloidoses is the identification of the cellular events that lead from synthesis of an amyloid precursor protein to its conversion to the amyloid fiber subunit. We address this question by characterizing the effects of an amyloidogenic mutation on the intracellular processing of its protein product. The protein, a mutant of the cysteine protease inhibitor cystatin C, is the amyloid precursor protein in Hereditary Cerebral Hemorrhage with Amyloidosis--Icelandic type (HCHWA-I). The amyloid fibers are composed of mutant cystatin C (L68Q) that lacks the first 10 amino acids. We have previously shown that processing of wild-type cystatin C entails formation of a transient intracellular dimer that dissociates prior to secretion, such that extracellular cystatin C is monomeric. We report here that the cystatin C mutation engenders several alterations in its intracellular trafficking. It forms a stable intracellular dimer that is partially retained in the endoplasmic reticulum and degraded. The bulk of mutant cystatin C that is secreted does not dissociate and is secreted as an inactive dimer. Thus, formation of the stable mutant cystatin C dimer is an early event in the pathogenesis of this disease.
Asunto(s)
Amiloidosis/genética , Hemorragia Cerebral/metabolismo , Cistatinas/metabolismo , Procesamiento Proteico-Postraduccional , Secuencia de Aminoácidos , Animales , Transporte Biológico , Células CHO , Hemorragia Cerebral/genética , Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Cricetinae , Cistatina C , Cistatinas/genética , Cistatinas/aislamiento & purificación , Cisteína Endopeptidasas/metabolismo , Dimerización , Retículo Endoplásmico/metabolismo , Humanos , MutaciónRESUMEN
To define the cellular processing of human cystatin C as well as to lay the groundwork for investigating its contribution to lcelandic Hereditary Cerebral Hemorrhage with Amyloidosis (HCHWA-I), we have characterized the trafficking, secretion, and extracellular fate of human cystatin C in transfected Chinese hamster ovary (CHO) cells. It is constitutively secreted with an intracellular half-life of 72 min. Gel filtration of cell lysates revealed the presence of three cystatin C immunoreactive species; an 11 kDa species corresponding to monomeric cystatin C, a 33 kDa complex that is most likely dimeric cystatin C and immunoreactive material, > or = 70 kDa, whose composition is unknown. Intracellular monomeric cystatin C is functionally active as a cysteine protease inhibitor, while the dimer is not. Medium from the transfected CHO cells contained only active monomeric cystatin C indicating that the cystatin C dimer, formed during intracellular trafficking, is converted to monomer at or before secretion. Cells in which exit from the endoplasmic reticulum (ER) was blocked with brefeldin A contained the 33 kDa species, indicating that cystatin C dimerization occurs in the ER. After removal of brefeldin A, there was a large increase in intracellular monomer suggesting that dimer dissociation occurs later in the secretion pathway, after exiting the ER but prior to release from the cell. Extracellular monomeric cystatin C was found to be internalized into lysosomes where it again dimerized, presumably as a consequence of the low pH of late endosome/lysosomes. As a dimer, cystatin C would be prevented from inhibiting the lysosomal cysteine proteases. These results reveal a novel mechanism, transient dimerization, by which cystatin C is inactivated during the early part of its trafficking through the secretory pathway and then reactivated prior to secretion. Similarly, its uptake by the cell also leads to its redimerization in the lysosomal pathway.
Asunto(s)
Cistatinas/metabolismo , Orgánulos/metabolismo , Animales , Brefeldino A , Células CHO , Células Cultivadas , Células Clonales , Cricetinae , Cicloheximida/farmacología , Ciclopentanos/farmacología , Cistatina C , Cistatinas/biosíntesis , Cistatinas/química , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/metabolismo , Dimerización , Retículo Endoplásmico/metabolismo , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , Humanos , Lisosomas/metabolismo , Orgánulos/efectos de los fármacos , Papaína/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Piel/citología , Piel/metabolismo , TransfecciónRESUMEN
A total of 66 skin biopsies from persons with Alzheimer's disease (AD) or Down's syndrome (DS) and from persons without AD were used in this study. The age range was from 7 to 89 years. Positive immunoreactivity of skin biopsies to monoclonal antibody 4G8, which is reactive to amino acid residue 17-24 of synthetic amyloid beta protein (A beta), and 4G8-Fab (the antigen-binding fragment of 4G8 IgG, reactive only to amyloid plaque) was observed in the epidermis-dermis junction or the basement membrane of the epidermis and in some blood vessels of the biopsy skins of 13/18 (72%) AD, 9/10 (90%) DS, and 14/38 (37%) non-AD control cases. The Fisher exact probability test revealed a significant difference (P = 0.0415 one-tailed) in immunoreactivity between AD and age-matched controls. There was also a significant difference (P = 0.0152 one-tailed; P = 0.0200 two-tailed) between DS and age-matched control in the same test. Immuno-gold electron microscopy examination of these cases with positive immunoreactivity revealed that the gold particles were deposited along the basement membrane of the epidermis. Amyloid fibrils were not observed in the regions with gold particles. Results of this study suggest that A beta is associated with the basement membrane of skin and is present in amorphous, non-fibrillar form as soluble A beta.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Síndrome de Down/metabolismo , Piel/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Biopsia , Niño , Preescolar , Síndrome de Down/patología , Femenino , Humanos , Inmunohistoquímica , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Valores de Referencia , Piel/patologíaRESUMEN
Viral vectors derived from herpes simplex virus, type-1 (HSV), can transfer and express genes into fully differentiated, post-mitotic neurons. These vectors also transduce cells effectively in organotypic hippocampal slice cultures. Nanoliter quantities of a virus stock of HSVlac, an HSV vector that directs expression of E. coli beta-galactosidase (beta-gal), were microapplied into stratum pyramidale or stratum granulosum of slice cultures. Twenty-four hours later, a cluster of transduced cells expressing beta-gal was observed at the microapplication site. Gene transfer by microapplication was both effective and rapid. The titer of the HSVlac stocks was determined on NIH3T3 cells. Eighty-three percent of the beta-gal forming units successfully transduced beta-gal after microapplication to slice cultures. beta-Gal expression was detected as rapidly as 4 h after transduction into cultures of fibroblasts or hippocampal slices. The rapid expression of beta-gal by HSVlac allowed efficient transduction of acute hippocampal slices. Many genes have been transduced and expressed using HSV vectors; therefore, this microapplication method can be applied to many neurobiological questions.
Asunto(s)
Técnicas de Transferencia de Gen , Hipocampo/metabolismo , Animales , Escherichia coli/enzimología , Escherichia coli/genética , Vectores Genéticos/fisiología , Herpesvirus Humano 1/enzimología , Herpesvirus Humano 1/genética , Hipocampo/citología , Técnicas In Vitro , Neuronas/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción Genética , beta-Galactosidasa/biosíntesis , beta-Galactosidasa/genéticaRESUMEN
Loss of hippocampal interneurons has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainate. We investigated the relationship between KA induced epileptiform discharge and loss of interneurons in hippocampal slice cultures. Application of KA (1 microM) produced reversible epileptiform discharge without neurotoxicity. KA (5 microM), in contrast, produced irreversible epileptiform discharge and neurotoxicity, suggesting that the irreversible epileptiform discharge was required for the neuronal loss. Loss of CA3 pyramidal cells and parvalbumin-like immunoreactive (PV-I) interneurons preceded loss of somatostatin-like immunoreactive (SS-I) interneurons suggesting a different time course of KA neurotoxicity in these subpopulations of interneurons.
Asunto(s)
Hipocampo/fisiología , Interneuronas/fisiología , Ácido Kaínico/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Epilepsia/inducido químicamente , Epilepsia/fisiopatología , Potenciales Evocados/efectos de los fármacos , Hipocampo/efectos de los fármacos , Hipocampo/patología , Inmunohistoquímica , Interneuronas/efectos de los fármacos , Interneuronas/patología , Fibras Nerviosas/fisiología , Técnicas de Cultivo de Órganos , Parvalbúminas/análisis , Parvalbúminas/metabolismo , Células Piramidales/efectos de los fármacos , Células Piramidales/patología , Células Piramidales/fisiología , Somatostatina/análisis , Somatostatina/metabolismo , Factores de TiempoRESUMEN
In organotypic hippocampal slice cultures, kainate (KA) specifically induces cell loss in the CA3 region while N-methyl-D-aspartate induces cell loss in the CA1 region. The sensitivity of slice cultures to KA toxicity appears only after 2 weeks in vitro which parallels the appearance of mossy fibers. KA toxicity is potentiated by co-application with the GABA-A antagonist, picrotoxin. These data suggest that the excitotoxicity of KA in slice cultures is modulated by both excitatory and inhibitory synapses.
Asunto(s)
Hipocampo/efectos de los fármacos , Ácido Kaínico/toxicidad , Animales , Animales Recién Nacidos , Hipocampo/citología , N-Metilaspartato/farmacología , Fibras Nerviosas/efectos de los fármacos , Vías Nerviosas/citología , Vías Nerviosas/efectos de los fármacos , Neuronas/efectos de los fármacos , Técnicas de Cultivo de Órganos , Picrotoxina/farmacología , Ratas , Ratas Sprague-Dawley , Sinapsis/efectos de los fármacosRESUMEN
Nineteen cases of hereditary cystatin C amyloidosis with cerebral haemorrhage are described. The first haemorrhage occurred between the ages of 20 and 41 years and the period of survival varied from 10 days to 23 years after the first insult. Progressive dementia was a striking clinical symptom in 17 of the patients and in two cases dementia was the first sign. At the last examination severe dementia and pronounced pathological EEG were established in the majority of the patients. Infiltration of amyloid substance positive for anti-cystatin C was found in the proximity of the blood vessels and in their walls. Lesions in the cerebral microvascular system together with haemorrhages and infarcts caused thereby were considered to be an adequate explanation of the dementia in these patients. In view of the discovery of amyloid discharges in tissues outside the CNS it is adjudged more correct to use the name Hereditary Cystatin C Amyloidosis (HCCA).
Asunto(s)
Amiloidosis/metabolismo , Hemorragia Cerebral/genética , Cistatinas/metabolismo , Demencia/etiología , Adulto , Factores de Edad , Amiloidosis/patología , Encéfalo/patología , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/metabolismo , Proteínas del Líquido Cefalorraquídeo/metabolismo , Cistatina C , Femenino , Humanos , MasculinoRESUMEN
Clinically normal skin from 47 individuals aged 9-70 years was investigated. Cystatin C amyloid deposits were found in various locations of the skin by light and/or electron microscopy, in all 12 patients with a clinical history of hereditary cystatin C amyloidosis (HCCA). Six asymptomatic individuals, who had the Alu 1 restriction fragment length polymorphism (RFLP) marker reported to cosegregate with the disease, also had cystatin C amyloid deposits in the skin. Three asymptomatic individuals (age 17-46) belonging to the HCCA families were without amyloid in the skin but had Alu 1 RFLP marker. Skin from 12 individuals who served as controls and skin from 14 close relatives of the patients was negative for amyloid. Punch biopsy of the skin is a simple procedure which is of value for the diagnosis of HCCA, even before the appearance of clinical symptoms. This method might also be of use in following progression of the disease.
Asunto(s)
Amiloide/análisis , Amiloidosis/metabolismo , Cistatinas/análisis , Piel/química , Adolescente , Adulto , Amiloidosis/patología , Cistatina C , Femenino , Enfermedades Genéticas Congénitas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Piel/ultraestructuraRESUMEN
Nineteen cases with verified Hereditary Cystatin C Amyloid Angiopathy are presented. All of the cases had one or more cerebrovascular insults starting at the age of 20-41 years and survived from 10 days to 23 years after the first insult. Progressive dementia was a prominent clinical feature in seventeen cases of whom two presented with dementia. At the last examination the majority had severe dementia and severely abnormal EEG. Anti-cystatin C positive amyloid vascular and perivascular infiltrates were found. The resulting damage to the microvasculature of the brain and secondary hemorrhages and infarctions were considered to be an adequate explanation for the dementia in these cases. Skin biopsies can now probably be used to demonstrate cystatin C positive amyloid deposits conclusively in the tissues of these patients.
Asunto(s)
Amiloidosis/complicaciones , Cistatinas , Demencia/etiología , Adolescente , Adulto , Amiloidosis/genética , Amiloidosis/patología , Anticuerpos/análisis , Encéfalo/patología , Arterias Cerebrales/patología , Cistatina C , Cistatinas/análisis , Cistatinas/inmunología , Demencia/patología , Femenino , Humanos , Islandia , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Brain biopsies from two patients with non-hereditary cerebral hemorrhages and eighty autopsied cases with the clinical diagnosis of dementia are presented. The biopsied cases, both males aged 64 and 59, had a sudden onset of cerebral hemorrhage, mild progressive dementia and cystatin C cerebral amyloid angiopathy. Of the autopsied cases 59 had senile plaques and cerebral amyloid angiopathy was also found in 36 of them. Both senile plaques and the blood vessel amyloid stained positively with beta-protein antibodies, and five of them also showed a positive reaction to cystatin C antibodies. These cystatin C positive cases were three males aged 76, 80 and 83, and one female 93 years old and the fifth case was a female aged 47 with Down's syndrome.