Amiloidose renal familiar em cães da raça Shar-Pei / Family renal amyloidosis in Shar-Pei dogs / Amiloidosis renal familiar en perros Shar-Pei

A amiloidose renal familiar é uma doença incomum em cães, que afeta os rins e está associada ao acúmulo anormal de proteínas amiloides, com capacidade de promover danos orgânicos progressivos com comprometimento de funcionalidade. Caracterizada pela presença de conteúdo proteináceo glomerular, a amiloidose frequentemente está associada a quadros de falência renal, com presença de sinais clínicos variados, sendo uma condição grave e complexa. O presente artigo tem como objetivo descrever os achados clínico-laboratoriais, de imagem e histopatológicos de amiloidose familiar em dois cães da raça Shar-pei. Os animais apresentavam parentesco direto e evidenciavam sinais de cansaço, prostração e emagrecimento progressivo. As evidências clínico-laboratoriais e ultrassonográficas sugeriram a presença de glomerulonefropatia, sendo essa confirmada por exame histopatológico. Os dois cães, diante da gravidade do quadro, foram a óbito. A análise histopatológica evidenciou deposição de material proteináceo fibrilar na região glomerular e tubular, bem como infiltrado linfoplasmocítico, característicos de amiloidose renal. É essencial lembrar que a amiloidose renal familiar em cães é uma doença complexa e que as origens devem ser investigadas. O tratamento é desafiador, diante da inexistência de um manejo terapêutico definido para a doença, sendo este muitas vezes ineficaz. A empatia e o cuidado no manejo dessa condição podem ajudar a melhorar a qualidade de vida do paciente e fornecer conforto ao proprietário durante esse processo desafiador.

Family renal amyloidosis is an uncommon disease in dogs, which affects the kidneys and is associated with abnormal accumulation of amyloid proteins, capable of promoting progressive organic damage with impairment of functionality. Characterized by the presence of glomerular proteinaceous content, amyloidosis is often associated with renal failure, with the presence of varied clinical signs, being a serious and complex condition. This article aims to describe the clinical, laboratory, imaging and histopathological findings of familial amyloidosis in two Shar-pei dogs. The animals were directly related and evidenced signs of tiredness, prostration and progressive weight loss. Clinical, laboratory and ultrasonographic evidence suggested the presence of glomerulonephropathy, which was confirmed by histopathological examination. The two dogs, given the severity of the condition, died. Histopathological analysis showed deposition of fibrillar proteinaceous material in the glomerular and tubular region, as well as lymphoplasmocytic infiltrate, characteristic of renal amyloidosis. It is essential to remember that family renal amyloidosis in dogs is a complex disease and that the origins must be investigated. The treatment is challenging, given the lack of a defined therapeutic management for the disease, which is often ineffective. Empathy and care in managing this condition can help improve the patient's quality of life and provide comfort to the owner during this challenging process.

La amiloidosis renal familiar es una enfermedad poco común en perros, que afecta a los riñones y se asocia con la acumulación anormal de proteínas amiloides, con capacidad de promover daño orgánico progresivo con compromiso de la funcionalidad. Caracterizada por la presencia de contenido proteico glomerular, la amiloidosis suele asociarse a insuficiencia renal, con la presencia de signos clínicos variados, siendo una afección grave y compleja. El presente artículo tiene como objetivo describir los hallazgos clínico-laboratorios, imagenológicos e histopatológicos de la amiloidosis familiar en dos perros Sharpei. Los animales estaban directamente emparentados y presentaban signos de cansancio, postración y pérdida progresiva de peso. Los datos clínico-laboratorios y ecográficos sugirieron la presencia de glomerulonefropatía, la cual fue confirmada mediante examen histopatológico. Los dos perros, dada la gravedad del cuadro, fallecieron. El análisis histopatológico mostró depósito de material proteico fibrilar en la región glomerular y tubular, así como infiltrado linfoplasmocitario, característico de la amiloidosis renal. Es fundamental recordar que la amiloidosis renal familiar en perros es una enfermedad compleja y que es necesario investigar sus orígenes. El tratamiento es un desafío, dada la falta de un manejo terapéutico definido para la enfermedad, que muchas veces resulta ineficaz. La empatía y el cuidado en el manejo de esta afección pueden ayudar a mejorar la calidad de vida del paciente y brindar comodidad al propietario durante este desafiante proceso.

Synthesis and biological activity evaluation of phthalimide-donepezil hybrids / 药学学报

A series of phthalimide-donepezil (PTA-DPZ) hybrids (5a-e, 6a-l) were designed, synthesized and evaluated as selective inhibitors of acetylcholinesterase (AChE). The results showed that some hybrids had strong AChE inhibitory activity with half maximal inhibitory concentration (IC50) at nanomolar range, which was better than the control drugs galanthamine and tacrine, and equivalent to DPZ. Compound 6k exhibited the strongest inhibition to AChE with an IC50 value of 0.13 μmol·L-1. Kinetic and molecular modeling studies showed that 6k targeted both catalytic active site and peripheral anionic site of AChE. Moreover, some compounds could inhibit AChE-induced β-amyloid (Aβ) aggregation. In addition, absorption, distribution, metabolism and excretion prediction results showed 6k conforms to the Lipinski's rule of five and had high partition coefficient P value. These compounds, especially 6k, may be considered as a dual-functional lead compound for in-depth research.

Huanglian Jiedutang Regulates HIF-1α/VEGF Signaling Pathway to Improve Learning and Memory Abilities of APP/PS1 Transgenic Mice / 中国实验方剂学杂志

ObjectiveTo reveal the effects of Huanglian Jiedutang （HLJDT） on the learning and memory abilities of APP/PS1 transgenic mice via hypoxia-inducible factor-1α （HIF-1α）/vascular endothelial growth factor （VEGF） signaling pathway. MethodForty 5-month-old β-amyloid precursor protein （APP）/presenilin 1（PS1） mice were randomized into the model， donepezil （0.001 g·kg-1·d-1）， and low-， medium-， and high-dose （1.5， 3， 6 g·kg-1·d-1， respectively） HLJDT groups， and 8 C57BL/6 mice were taken as the normal group. After 45 days of continuous administration， Morris water maze test was conducted， and the organ indexes were calculated. The morphological structure of cerebral vascular endothelial cells in mice was observed under a transmission electron microscope. Western blot was employed to measure the protein levels of APP， HIF-1α， VEGF，VEGFA， and brain-derived neurotrophic factor （BDNF） in the hippocampus. The mRNA levels of APP， HIF-1α， and VEGF were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the normal group， the model group showed prolonged escape latency （P<0.05）， reduced distance and time around the target platform （P<0.05）， decrease brain and spleen indexes （P<0.05）， vascular endothelial cells with karyopyknosis and not abundant cytoplasm， up-regulated protein levels of APP， HIF-1α， VEGF， and VEGFA （P<0.05）， down-regulated protein level of BDNF （P<0.05）， and up-regulated mRNA levels of APP， HIF-1α， and VEGF （P<0.05） in the hippocampus. Compared with the model group， high-dose HLJDT shortened the escape latency （P<0.05）， increased the distance and time around the target platform （P<0.05）， raised the brain and spleen indexes （P<0.05）， repaired the organelles of vascular endothelial cells， down-regulated the protein levels of APP， HIF-1α， VEGF， and VEGFA （P<0.05）， up-regulated the protein level of BDNF （P<0.05）， and down-regulated the mRNA levels of APP， HIF-1α， and VEGF （P<0.05） in the hippocampus. ConclusionHLJDT can improve the learning and memory abilities of mice by reducing the expression of HIF-1α and VEGF， thus protecting the nerves.

The past, present and future of Alzheimer's disease - part 1: the past / O passado, presente e futuro da doença de Alzheimer - parte 1: o passado

Abstract Background Alzheimer's disease (AD) was described in 1907, and since then it changed from a relatively rare condition to one of the most prevalent diseases. Objective To describe the evolution of the notions of dementias and AD, and to investigate the reasons for the increase in scientific interest in AD. Methods A historical analysis was carried out on knowledge about dementia, the site of mental activity, the relationships between brain diseases and mental activity, and on the advances in research about AD, since its discovery until the publication of the amyloid cascade hypothesis in 1992. A search was carried out in the National Library of Medicine (PubMed) for scientific articles that included the terms dementia or AD over 50 years, from 1972 to 2021. Results The scientific research on AD increased from 615 papers with the term AD in the first decade (1972-1981), to 100,028 papers in the last decade (2012-2021): an increase of 162.6 times whereas publications with the term dementia increased 28.6 times in the same period. In the 1960s and 1970s, a consensus was reached that AD is responsible for the majority of cases of dementia previously known as senile dementia. In the 1980s, beta-amyloid peptide was identified in the core of the senile plaque, hyperphosphorylated tau protein was found in neurofibrillary tangles, and a mutation was discovered in a hereditary form of AD. Conclusion The expansion of the concept of AD to include senile dementia, and the discoveries that occurred in the 1980s greatly expanded research in AD.

Resumo Antecedentes A doença de Alzheimer (DA) foi descrita em 1907 e, desde então, deixou de ser relativamente rara para se tornar uma das doenças mais prevalentes. Objetivo Descrever a evolução das noções sobre demências e DA e investigar as razões do aumento do interesse científico pela DA. Métodos Foi realizada uma análise histórica dos conhecimentos sobre demência, o local da atividade mental, as relações entre doenças cerebrais e a atividade mental, e sobre os avanços na pesquisa sobre a DA, desde a sua descoberta até a publicação da hipótese da cascata amiloide em 1992. Foi realizada uma busca na Biblioteca Nacional de Medicina dos Estados Unidos da América (PubMed) por artigos científicos que incluíssem os termos demência ou DA nos 50 anos, de 1972 a 2021. Resultados A pesquisa científica sobre DA aumentou de 615 artigos com o termo doença de Alzheimer na primeira década (1972-1981), para 100.028 artigos na última década (2012-2021): um aumento de 162,6 vezes enquanto as publicações com o termo demência aumentaram 28,6 vezes no mesmo período. Nas décadas de 1960 e 1970, chegou-se a um consenso de que a DA é responsável pela maioria dos casos de demência, anteriormente conhecida como demência senil. Na década de 1980, o peptídeo beta-amiloide foi identificado no núcleo da placa senil, a proteína tau hiperfosforilada foi encontrada em emaranhados neurofibrilares e uma mutação foi descoberta em uma forma hereditária de DA. Conclusão A expansão do conceito de DA para incluir a demência senil e as descobertas ocorridas na década de 1980 ampliaram enormemente a pesquisa em DA.

¿Qué hay de nuevo en el diagnóstico de amiloidosis? / What is new in diagnosis of amyloidosis?

La amiloidosis siempre ha representado un desafío diagnóstico. En el año 2020, el Grupo de Estudio de Amiloidosis (GEA), confeccionó la Guía de Práctica Clínica para el Diagnóstico de Amiloidosis. Nuevas líneas de investigación se han desarrollado posteriormente. Esta revisión narrativa tiene como intención explorar el estado del arte en el diagnóstico de la amiloidosis. En pacientes con amiloidosis se recomienda la tipificación de la proteína mediante espectrometría de masa, técnica de difícil ejecución por requerir de microdisectores láser para la preparación de la muestra. Algunas publicaciones recientes proponen otros métodos para obtener la muestra de amiloide que se va a analizar, permitiendo prescindir de la microdisección. Por otra parte, en pacientes con Amiloidosis ATTR confirmada, la recomendación de secuenciar el gen amiloidogénico se encontraba destinada a los casos sospechosos de ATTR hereditaria (ATTRv,), pero actualmente esta se ha extendido a todos los pacientes sin importar la edad. En lo que respecta a los estudios complementarios orientados al diagnóstico de compromiso cardíaco, se ha propuesto el uso de la inteligencia artificial para su interpretación, permitiendo la detección temprana de la enfermedad y el correcto diagnóstico diferencial. Para el diagnóstico de neuropatía, las últimas publicaciones proponen el uso de la cadena ligera de neurofilamento sérica, que también podría resultar un indicador útil para seguimiento. Finalmente, con referencia a la amiloidosis AL, la comunidad científica se encuentra interesada en definir qué características determinan el carácter amiloidogénico de las cadenas livianas. La N-glicosilación de dichas proteínas impresiona ser uno de los determinantes en cuestión. (AU)

Amyloidosis has always represented a diagnostic challenge. In 2020, the Amyloidosis Study Group (ASG) developed the "Clinical Practice Guideline for the Diagnosis of Amyloidosis". New lines of research have subsequently emerged. This narrative review aims to explore the state of the art in the diagnosis of amyloidosis diagnosis. In patients with amyloidosis, protein typing by mass spectrometry is recommended, a technique hard to perform because it requires laser microdissection for sample preparation. Recent publications propose other methods to obtain the amyloid sample to be analyzed, making it possible to dispense with microdissection. On the other hand, in patients with confirmed TTR amyloidosis (aTTR), the recommendation to sequence the amyloidogenic gene was intended for suspected cases of hereditary aTTR but has now been extended to all patients regardless of age. (AU)

Hemorragia digestiva como forma de presentación poco usual de amiloidosis intestinal primaria: reporte de caso

La amiloidosis intestinal es una enfermedad sistémica rara y subdiagnosticada, la cual se caracteriza por el depósito extracelular de proteínas que se agrupan en fibras amiloides. Esta entidad es infrecuente y suele ser una forma de presentación en el contexto de una amiloidosis sistémica, cuyo diagnóstico se basa en la presencia a amiloide en la histología. La clínica suele ser inespecífica; diarrea crónica, pérdida de peso, dolor y distensión abdominal; siendo la hemorragia digestiva una manifestación muy poco frecuente. Se presenta el caso de una mujer de 61 años con clínica de baja de peso, distención abdominal, náuseas, vómitos y melena. En la tomografía se evidenció un engrosamiento mural de asas yeyunales con captación de contraste, hallazgo que se corroboró con enteroscopia anterógrada a doble balón en el cual se evidenciaron múltiples úlceras en yeyuno, signos de atrofia, friabilidad y dilatación de luz yeyunal. En la anatomía patológica se aprecia arquitectura vellositaria distorsionada y ulcerada con histoquímica positiva a Rojo Congo e inmunohistoquímica lambda (+++). Además, se realizó aspirado de médula ósea y biopsia de hueso compatible con infiltración de mieloma múltiple monoclonal a cadena Lambda. Durante la estancia hospitalaria la paciente cursó con complicaciones como la desnutrición crónica, infección recurrente y varios episodios de suboclusión intestinal; caracterizada por neumatosis intestinal; debido a múltiples episodios de estas complicaciones la paciente fallece. Dentro de la práctica clínica en gastroenterología la amiloidosis intestinal como parte del diagnóstico diferencial de la hemorragia digestiva alta es infrecuente, por lo que los antecedentes de diagnóstico de mieloma múltiple u otras gammapatías monoclonales asociadas a cadenas ligeras es crucial para un diagnóstico precoz y tratamiento adecuado.

Intestinal amyloidosis is a rare and underdiagnosed systemic disease, which is characterized by the extracellular deposition of proteins that are grouped into amyloid fibers. This entity is rare and is usually a form of presentation in the context of systemic amyloidosis, the diagnosis of which is based on the presence of amyloid in histology. The clinic is usually non-specific; chronic diarrhea, weight loss, abdominal pain and bloating; Gastrointestinal bleeding is a very rare manifestation. The case of a 61-year-old woman with symptoms of weight loss, abdominal distension, nausea, vomiting and long hair is presented. Tomographically, a wall thickening of jejunal loops with contrast uptake was evidenced, a finding that was corroborated by a double-balloon anterograde stereoscopy in which multiple were evidenced. The pathology shows distorted and ulcerated villous architecture with positive histochemistry for Congo Red and LAMBDA (+++) immunohistochemistry. In addition, bone marrow aspirate and bone biopsy compatible with infiltration of Lambda chain monoclonal multiple myeloma were performed. During the hospital stay, the patient developed complications such as chronic malnutrition, recurrent infection and several episodes of intestinal subocclusion; characterized by intestinal pneumatosis; due to multiple episodes of these complications, the patient died. Within clinical practice in gastroenterology, intestinal amyloidosis as part of the differential diagnosis of upper gastrointestinal bleeding is infrequent, so a history of diagnosis of multiple myeloma or other monoclonal gammopathy associated with light chains is crucial for early diagnosis and adequate treatment.

Brazilian consensus for diagnosis, management and treatment of hereditary transthyretin amyloidosis with peripheral neuropathy: second edition / Consenso brasileiro para o diagnóstico, manejo e tratamento da polineuropatia amiloidótica familiar associada à transtirretina: segunda edição

Abstract Hereditary transthyretin amyloidosis with peripheral neuropathy (ATTRv-PN) is an autosomal dominant inherited sensorimotor and autonomic polyneuropathy with over 130 pathogenic variants identified in the TTR gene. Hereditary transthyretin amyloidosis with peripheral neuropathy is a disabling, progressive and life-threatening genetic condition that leads to death in ~ 10 years if untreated. The prospects for ATTRv-PN have changed in the last decades, as it has become a treatable neuropathy. In addition to liver transplantation, initiated in 1990, there are now at least 3 drugs approved in many countries, including Brazil, and many more are being developed. The first Brazilian consensus on ATTRv-PN was held in the city of Fortaleza, Brazil, in June 2017. Given the new advances in the area over the last 5 years, the Peripheral Neuropathy Scientific Department of the Brazilian Academy of Neurology organized a second edition of the consensus. Each panelist was responsible for reviewing the literature and updating a section of the previous paper. Thereafter, the 18 panelists got together virtually after careful review of the draft, discussed each section of the text, and reached a consensus for the final version of the manuscript.

Resumo Polineuropatia amiloidótica familiar associada a transtirretina (ATTRv-PN) é uma polineuropatia sensitivo-motora e autonômica hereditária autossômica dominante com mais de 130 variantes patogênicas já identificadas no gene TTR. A ATTRv-PN é uma condição genética debilitante, progressiva e que ameaça a vida, levando à morte em ~ 10 anos se não for tratada. Nas últimas décadas, a ATTRv-PN se tornou uma neuropatia tratável. Além do transplante de fígado, iniciado em 1990, temos agora 3 medicamentos modificadores de doença aprovados em muitos países, incluindo o Brasil, e muitas outras medicações estão em desenvolvimento. O primeiro consenso brasileiro em ATTRv-PN foi realizado em Fortaleza em junho de 2017. Devido aos novos avanços nesta área nos últimos 5 anos, o Departamento Científico de Neuropatias Periféricas da Academia Brasileira de Neurologia organizou uma segunda edição do consenso. Cada panelista ficou responsável por rever a literatura e atualizar uma parte do manuscrito. Finalmente, os 18 panelistas se reuniram virtualmente após revisão da primeira versão, discutiram cada parte do artigo e chegaram a um consenso sobre a versão final do manuscrito.

Amyloid spell – A close mimic of transient ischemic attack!

Transient focal neurological episodes, also called amyloid spells occur as recurrent, transient episodes of spreading paresthesia seen in 14% of cerebral amyloid angiopathy (CAA) patients. An 81-year-old gentleman with coronary artery disease and a left ventricular clot was on anticoagulant treatment. He presented with three episodes of tingling in the left fingers spreading to the left arm and left leg, each lasting for 10 min. Magnetic resonance imaging of the brain with susceptibility imaging showed convexity hemorrhage, and curvilinear blooming in sulcal spaces of the right cerebral convexity and left precuneus. Warfarin was stopped. He was treated with clobazam, aspirin, and atorvastatin. He improved, so was discharged after 2 days. Amyloid spells can be confused with transient ischemic attack (TIA) or its mimics and the treatment given for TIA can lead to intracranial hemorrhage in CAA patients. Radiological features aid in the diagnosis of CAA and antiplatelets need to be administered cautiously in patients with suspected TIA.

A rare case of sulcal hemorrhage after ischemic stroke � A case report

Atraumatic Non-aneurysmal sulcal subarachnoid hemorrhage is very rare. Sulcal subarachnoid hemorrhage (sSAH) is characterized by isolated bleeding in one or a few adjacent sulci. Central sulcus hemorrhage is a rare imaging finding. There are many causes for sSAH. In older patients, sSAH is due to Cerebral Amyloid Angiopathy (CAA), while in younger patients, reversible cerebral vasoconstriction syndrome (RCVS) is the most frequent etiology. Imaging studies help in the evaluation of sSAH. We report a rare case of an isolated central sulcus hemorrhage on computed tomography. sSAH usually occur on the side with acute ischemic stroke, and it is unusual for sSAH to occur on the opposite side of the infarct territory, but in our case sSAH occurred on opposite side, but after a gap of 3 years.

Clinical profile of patients with cardiac amyloidosis in India

Limited data exists on patients with cardiac amyloidosis (CA) in India, due to underdiagnosis and late presentation. We present single centre data from 13 patients over a 4 year period with a median age of 65 years. A majority presented with symptomatic heart failure (69%) and eight patients had confirmed AL amyloidosis. At the end of the follow up period, 46% patients died, with 30% of the overall cohort dead within six months. Among the survivors, 71% continue to have NYHA grade III/IV symptoms. A suggested algorithm for earlier diagnosis in resource constrained settings is also presented.

Masked ocular amyloidosis simulating xanthelasma and follicular conjunctivitis: case reports / Amiloidose ocular mascarada simulando xantelasma e conjuntivite folicular: relatos de casos

ABSTRACT Amyloidosis is a rare disease in which ocular involvement may occur as an isolated event or associated with a systemic disease. This paper describes two clinical cases of ophthalmologic manifestations of amyloidosis: a bilateral eyelid lesion similar to xanthelasma and tarsal conjunctival disease similar to follicular conjunctivitis. The anatomopathological analysis confirmed the diagnosis.

RESUMO A amiloidose é uma doença rara que pode ter o acometimento ocular como forma isolada ou estar associada a doenças sistêmicas. Neste relato, são descritos dois casos clínicos de alterações oftalmológicas da amiloidose: um que se manifestou por meio de lesão palpebral bilateral de aspecto similar ao xantelasma. O outro era uma afecção em conjuntiva tarsal, semelhante à conjuntivite folicular. O estudo anatomopatológico confirmou o diagnóstico.

Effect of silibinin and trans-chalcone in an Alzheimer's disease-like model generated by insulin amyloids

Amyloid fibrils are characteristic of several disorders including Alzheimer's disease (AD), with no cure or preventive therapy. Diminishing amyloid deposits using aromatic compounds is an interesting approach toward AD treatment. The present study examined the anti-fibrillogenic effects of silibinin and trans-chalcone in vitro, in vivo, and in silico on insulin amyloids. In vitro incubation of insulin at 37°C for 24 h induced amyloid formation. Addition of trans-chalcone and silibinin to insulin led to reduced amounts of fibrils as shown by thioflavin S fluorescence and Congo red absorption spectroscopy, with a better effect observed for silibinin. In vivo bilateral injection of fibrils formed by incubation of insulin in the presence or absence of silibinin and trans-chalcone or insulin fibrils plus the compounds in rats' hippocampus was performed to obtain AD characteristics. Passive avoidance (PA) test showed that treatment with both compounds efficiently increased latency compared with the model group. Histological investigation of the hippocampus in the cornu ammonis (CA1) and dentate gyrus (DG) regions of the rat's brain stained with hematoxylin-eosin and thioflavin S showed an inhibitory effect on amyloid aggregation and markedly reduced amyloid plaques. In silico, a docking experiment on native and fibrillar forms of insulin provided an insight onto the possible binding site of the compounds. In conclusion, these small aromatic compounds are suggested to have a protective effect on AD.

Serum amyloid A in children and adolescents: association with overweight and carotid intima-media thickness

ABSTRACT Objective To compare serum amyloid A concentrations between overweight and eutrophic children and adolescents and to relate it to lipid profiles, glucose tolerance, and carotid intima-media thickness. Methods One hundred children and adolescents (mean age: 10.8±3.16 years) were included and divided into two groups: overweight and non-overweight. The following were evaluated: Z-score body mass index, carotid intima-media thickness, lipid metabolism biomarkers (lipid profile and apolipoproteins A1 and B), inflammatory biomarkers (ultra-sensitive C-reactive protein and serum amyloid A), and glucose homeostasis model assessment of insulin resistance. Results The groups were homogeneous in age, sex, and pubertal stage. Higher levels of triglycerides, apolipoprotein B, homeostasis model assessment of insulin resistance, ultrasensitive C-reactive protein, serum amyloid A, and carotid intima-media thickness were observed in the overweight group. In the multivariate analysis, age (OR=1.73; 95%CI: 1.16-2.60, p=0.007), Z-score body mass index (OR=3.76; 95%CI: 1.64-8.59, p=0.002), apolipoprotein-B (OR=1.1; 95%CI: 1.01-1.2, p=0.030), and carotid intima-media thickness (OR=5.00; 95%CI: 1.38-18.04, p=0.014) were independently associated with serum amyloid A levels above the fourth quartile of the studied sample (>9.4mg/dL). Conclusion Overweight children and adolescents had higher serum amyloid A concentrations than eutrophic children. There was an independent association between higher concentrations of serum amyloid A and Z-score, body mass index, apolipoprotein B, and carotid intima-media thickness, indicating the importance of this inflammatory biomarker in identifying the early risk of atherosclerosis.

Expression, purification and micelle reconstruction of the transmembrane domain of the human amyloid precursor protein for NMR studies / 生物工程学报

The multiple-step cleavage of amyloid precursor protein (APP) generates amyloid-β peptides (Aβ), highly toxic molecules causing Alzheimer's disease (AD). The nonspecific cleavage between the transmembrane region of APP (APPTM) and γ-secretase is the key step of Aβ generation. Reconstituting APPTM under physiologically-relevant conditions is crucial to investigate how it interacts with γ-secretase and for future AD drug discovery. Although producing recombinant APPTM was reported before, the large scale purification was hindered by the use of biological protease in the presence of membrane protein. Here, we expressed recombinant APPTM in Escherichia coli using the pMM-LR6 vector and recovered the fusion protein from inclusion bodies. By combining Ni-NTA chromatography, cyanogen bromide cleavage, and reverse phase high performance liquid chromatography (RP-HPLC), isotopically-labeled APPTM was obtained in high yield and high purity. The reconstitution of APPTM into dodecylphosphocholine (DPC) micelle generated mono dispersed 2D 15N-1H HSQC spectra in high quality. We successfully established an efficient and reliable method for the expression, purification and reconstruction of APPTM, which may facilitate future investigation of APPTM and its complex in more native like membrane mimetics such as bicelle and nanodiscs.

Elevated Levels of Naturally-Occurring Autoantibodies Against the Extracellular Domain of p75NTR Aggravate the Pathology of Alzheimer's Disease / 神经科学通报·英文版

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.

A state-of-the-art review on miRNA in prevention and treatment of Alzheimer 's disease / 浙江大学学报·医学版

Alzheimer's disease (AD) is a multifactorial and heterogenic disorder. MiRNA is a class of non-coding RNAs with 19-22 nucleotides in length that can regulate the expression of target genes in the post-transcriptional level. It has been found that the miRNAome in AD patients is significantly altered in brain tissues, cerebrospinal fluid and blood circulation, as compared to healthy subjects. Experimental studies have suggested that expression changes in miRNA could drive AD onset and development via different mechanisms. Therefore, targeting miRNA expression to regulate the key genes involved in AD progression is anticipated to be a promising approach for AD prevention and treatment. Rodent AD models have demonstrated that targeting miRNAs could block biogenesis and toxicity of amyloid β, inhibit the production and hyper-phosphorylation of τ protein, prevent neuronal apoptosis and promote neurogenesis, maintain neural synaptic and calcium homeostasis, as well as mitigate neuroinflammation mediated by microglia. In addition, animal and human studies support the view that miRNAs are critical players contributing to the beneficial effects of cell therapy and lifestyle intervention to AD. This article reviews the most recent advances in the roles, mechanisms and applications of targeting miRNA in AD prevention and treatment based on rodent AD models and human intervention studies. The potential opportunities and challenges in clinical application of targeting miRNA for AD patients are also discussed.

Resveratrol and Sir2 Reverse Sleep and Memory Defects Induced by Amyloid Precursor Protein / 神经科学通报·英文版

Resveratrol (RES), a natural polyphenolic phytochemical, has been suggested as a putative anti-aging molecule for the prevention and treatment of Alzheimer's disease (AD) by the activation of sirtuin 1 (Sirt1/Sir2). In this study, we tested the effects of RES and Sirt1/Sir2 on sleep and courtship memory in a Drosophila model by overexpression of amyloid precursor protein (APP), whose duplications and mutations cause familial AD. We found a mild but significant transcriptional increase of Drosophila Sir2 (dSir2) by RES supplementation for up to 17 days in APP flies, but not for 7 days. RES and dSir2 almost completely reversed the sleep and memory deficits in APP flies. We further demonstrated that dSir2 acts as a sleep promotor in Drosophila neurons. Interestingly, RES increased sleep in the absence of dSir2 in dSir2-null mutants, and RES further enhanced sleep when dSir2 was either overexpressed or knocked down in APP flies. Finally, we showed that Aβ aggregates in APP flies were reduced by RES and dSir2, probably via inhibiting Drosophila β-secretase (dBACE). Our data suggest that RES rescues the APP-induced behavioral deficits and Aβ burden largely, but not exclusively, via dSir2.

Establishing and evaluating a robust method based on LC-MS/MS for simultaneous determination of Aβ1-42,Aβ1-40 and A β1-38 in cerebrospinal fluid / 中华检验医学杂志

Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.

Anti-amyloid-β disease-modifying therapies for Alzheimer′s disease: the dawn of a new era / 中华神经科杂志

Alzheimer′s disease (AD) is the most common neurodegenerative disease. Its etiology and pathogenesis remain unclear. Since its inception, the amyloid-β (Aβ) cascade hypothesis has dominated the field of AD research and has provided the intellectual framework for disease-modifying therapies. Nowadays, many Aβ-targeted therapies have been accelerated approval or received Food and Drug Administration′s breakthrough therapy designation which offers a new dawn for disease-modifying treating AD. This article reviews the research progress of clinical trials of Aβ-targeting modification therapies, and summarizes the lessons learned from the clinical failure with several classes of anti-Aβ drugs. Although many challenges remain, anti-Aβ therapies have become a promising treatment strategy for AD.

Advances in molecular imaging of cerebral amyloid angiopathy / 中华神经科杂志

Cerebral amyloid angiopathy (CAA) is a common age-related small vessel disease characterized by amyloid-β (Aβ) deposition in the wall of small arterioles and capillaries of the leptomeninges and cerebral cortex. Several molecular imaging technologies such as amyloid-β positron-emission tomography (PET) and 18F-fluorodeoxyglucose-PET have been successfully applied in the patients with CAA. Amyloid-PET may indicate the distribution and burden of Aβ deposition by the tracer′s specific binding to the pathological markers, providing qualitative and quantitative information for the diagnosis of CAA. However, amyloid-β PET is inadequate to differentiate CAA from other Aβ-related diseases like Alzheimer′s disease. Other novel techniques of molecular imaging including tau-PET, single photon emission computed tomography and other highly selective PET radioligands have been investigated widely at present. This article mainly reviewed the advances in molecular imaging of CAA.