Survival Bias and Crosstalk between Chronological and Behavioral Age: Age- and Genotype-Sensitivity Tests Define Behavioral Signatures in Middle-Aged, Old, and Long-Lived Mice with Normal and AD-Associated Aging

Malaltia d'Alzheimer; Envelliment; SupervivènciaAlzheimer’s disease; Aging; SurvivalEnfermedad de Alzheimer; Envejecimiento; SupervivenciaNew evidence refers to a high degree of heterogeneity in normal but also Alzheimer’s disease (AD) clinical and temporal patterns, increased mortality, and the need to find specific end-of-life prognosticators. This heterogeneity is scarcely explored in very old male AD mice models due to their reduced survival. In the present work, using 915 (432 APP23 and 483 C57BL/6 littermates) mice, we confirmed the better survival curves in male than female APP23 mice and respective wildtypes, providing the chance to characterize behavioral signatures in middle-aged, old, and long-lived male animals. The sensitivity of a battery of seven paradigms for comprehensive screening of motor (activity and gait analysis), neuropsychiatric and cognitive symptoms was analyzed using a cohort of 56 animals, composed of 12-, 18- and 24-month-old male APP23 mice and wildtype littermates. Most variables analyzed detected age-related differences. However, variables related to coping with stress, thigmotaxis, frailty, gait, and poor cognition better discriminated the behavioral phenotype of male APP23 mice through the three old ages compared with controls. Most importantly, non-linear age- and genotype-dependent behavioral signatures were found in long-lived animals, suggesting crosstalk between chronological and biological/behavioral ages useful to study underlying mechanisms and distinct compensations through physiological and AD-associated aging.This work was funded by the BrightFocus Foundation, US (A2017243S). The Neurovascular Research Laboratory is part of the INVICTUS+network, Instituto de Salud Carlos III (ISCIII), Spain [RD16/0019/0021], co-financed by the European Regional Development Fund FEDER. P.M. held a predoctoral fellowship from the Vall d’Hebron Research Institute

Impact of Cerebral Amyloid Angiopathy in Two Transgenic Mouse Models of Cerebral β-Amyloidosis: A Neuropathological Study

Microhemorragias cerebrales; Beta-amiloidosis cerebral; Resonancia magnética preclínicaCerebral microbleeds; Cerebral beta-amyloidosis; Preclinical MRIMicrohemorràgies cerebrals; Beta-amiloidosi cerebral; Ressonància magnètica preclínicaThe pathological accumulation of parenchymal and vascular amyloid-beta (Aβ) are the main hallmarks of Alzheimer’s disease (AD) and Cerebral Amyloid Angiopathy (CAA), respectively. Emerging evidence raises an important contribution of vascular dysfunction in AD pathology that could partially explain the failure of anti-Aβ therapies in this field. Transgenic mice models of cerebral β-amyloidosis are essential to a better understanding of the mechanisms underlying amyloid accumulation in the cerebrovasculature and its interactions with neuritic plaque deposition. Here, our main objective was to evaluate the progression of both parenchymal and vascular deposition in APP23 and 5xFAD transgenic mice in relation to age and sex. We first showed a significant age-dependent accumulation of extracellular Aβ deposits in both transgenic models, with a greater increase in APP23 females. We confirmed that CAA pathology was more prominent in the APP23 mice, demonstrating a higher progression of Aβ-positive vessels with age, but not linked to sex, and detecting a pronounced burden of cerebral microbleeds (cMBs) by magnetic resonance imaging (MRI). In contrast, 5xFAD mice did not present CAA, as shown by the negligible Aβ presence in cerebral vessels and the occurrence of occasional cMBs comparable to WT mice. In conclusion, the APP23 mouse model is an interesting tool to study the overlap between vascular and parenchymal Aβ deposition and to evaluate future disease-modifying therapy before its translation to the clinic.This work was funded by the Instituto de Salud Carlos III (ISCIII), (PI20/00465) and co-financed by the European Regional Development Fund (FEDER). The Neurovascular Research Laboratory is part of the RICORS-ICTUS-Enfermedades Vasculares Cerebrales network, ISCIII, Spain (RD21/0006/0007)

Brain ApoA-I, ApoJ and ApoE Immunodetection in Cerebral Amyloid Angiopathy

ApoA-I; ApoE; Cerebral amyloid angiopathyApoA-I; ApoE; Angiopatía amiloide cerebralApoA-I; ApoE; Angiopatia amiloide cerebralCerebral amyloid angiopathy (CAA) is a common cause of lobar intracerebral hemorrhage (ICH) in elderly individuals and it is the result of the cerebrovascular deposition of beta-amyloid (Aβ) protein. CAA is frequently found in patients with Alzheimer's disease (AD), although it has an independent contribution to the cognitive deterioration associated with age. Specific apolipoproteins (Apo) have been associated with Aβ fibrillization and clearance from the brain. In this regard, in the present study, we analyzed the brain levels of ApoE, ApoA-I, and ApoJ/clusterin in autopsy brains from 20 post-mortem cases with CAA type I, CAA type II, with parenchymal Aβ deposits or without Aβ deposits. Our objective was to find a possible differential pattern of apolipoproteins distribution in the brain depending on the CAA pathological presentation. The protein expression levels were adjusted by the APOE genotype of the patients included in the study. We found that ApoE and ApoJ were abundantly present in meningeal, cortical, and capillary vessels of the brains with vascular Aβ accumulation. ApoE and ApoJ also deposited extracellularly in the parenchyma, especially in cases presenting Aβ diffuse and neuritic parenchymal deposits. In contrast, ApoA-I staining was only relevant in capillary walls in CAA type I cases. On the other hand, ICH was the principal cause of death among CAA patients in our cohort. We found that CAA patients with ICH more commonly had APOEε2 compared with CAA patients without ICH. In addition, patients who suffered an ICH presented higher vascular ApoE levels in brain. However, higher ApoE presence in cortical arteries was the only independent predictor of suffering an ICH in our cohort after adjusting by age and APOE genotype. In conclusion, while ApoE and ApoJ appear to be involved in both vascular and parenchymal Aβ pathology, ApoA-I seems to be mainly associated with CAA, especially in CAA type I pathology. We consider that our study helps to molecularly characterize the distribution subtypes of Aβ deposition within the brain

Efectes de l'administració de tpa combinat amb dipyridamole sobre cèl·lules endotelials cerebrals humanes sotmeses a deprivació d'oxigen i glucosa

El DP és un agent usat de forma comú en la prevenció secundària de l'ictus per les seves propietats antiplaquetars. Ha estat proposat com a possible teràpia coadjuvant del tractament trombolític en fase aguda de l'ictus isquèmic amb rtPA neuroprotector per les seves propietats neuroprotectores, antiinflamatòries i antioxidants. En el present treball s'analitza la toxicitat de l'administració d'rtPA en cèl·lules endotelials cerebrals humanes sotmeses a isquèmia, així com els seus efectes sobre l'activació de MMPs. Posteriorment es combina l'administració d'rtPA amb Dipyridamole i s'analitzen els efectes en la toxicitat cel·lular i l'expressió d'MMPs

Association of candidate genetic variants and circulating levels of ApoE/ApoJ with common neuroimaging features of cerebral amyloid angiopathy

MRI; LipoproteinsRessonància magnètica; LipoproteïnesResonancia magnética; LipoproteínasIntroduction: Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of amyloid-β (Aβ) in brain vessels and is a main cause of lobar intracerebral hemorrhage (ICH) in the elderly. CAA is associated with magnetic resonance imaging (MRI) markers of small vessel disease (SVD). Since Aβ is also accumulated in Alzheimer’s disease (AD) in the brain parenchyma, we aimed to study if several single nucleotide polymorphisms (SNPs) previously associated with AD were also associated with CAA pathology. Furthermore, we also studied the influence of APOE and CLU genetic variants in apolipoprotein E (ApoE) and clusterin/apolipoprotein J (ApoJ) circulating levels and their distribution among lipoproteins. Methods: The study was carried out in a multicentric cohort of 126 patients with lobar ICH and clinical suspicion of CAA. Results: We observed several SNPs associated with CAA neuroimaging MRI markers [cortical superficial siderosis (cSS), enlarged perivascular spaces in the centrum semiovale (CSO-EPVS), lobar cerebral microbleeds (CMB), white matter hyperintensities (WMH), corticosubcortical atrophy and CAA-SVD burden score]. Concretely, ABCA7 (rs3764650), CLU (rs9331896 and rs933188), EPHA1 (rs11767557), and TREML2 (rs3747742) were significantly associated with a CAA-SVD burden score. Regarding circulating levels of apolipoproteins, protective AD SNPs of CLU [rs11136000 (T) and rs9331896 (C)] were significantly associated with higher HDL ApoJ content in the lobar ICH cohort. APOEε2 carriers presented higher plasma and LDL-associated ApoE levels whereas APOEε4 carriers presented lower plasma ApoE levels. Additionally, we observed that lower circulating ApoJ and ApoE levels were significantly associated with CAA-related MRI markers. More specifically, lower LDL-associated ApoJ and plasma and HDL-associated ApoE levels were significantly associated with CSO-EPVS, lower ApoJ content in HDL with brain atrophy and lower ApoE content in LDL with the extent of cSS. Discussion: This study reinforces the relevance of lipid metabolism in CAA and cerebrovascular functionality. We propose that ApoJ and ApoE distribution among lipoproteins may be associated with pathological features related to CAA with higher ApoE and ApoJ levels in HDL possibly enhancing atheroprotective, antioxidative, and anti-inflammatory responses in cerebral β-amyloidosis.This work was funded by the Instituto de Salud Carlos III (ISCIII), (PI17/00275, PI019/00421, PI20/00465, and PI20/00334) and co-financed by the European Regional Development Fund (FEDER). The Neurovascular Research Laboratory was part of the RICORS-ICTUS-Enfermedades Vasculares Cerebrales Network, ISCIII, Spain (RD21/0006/0007). CIBERDEM (CB07/08/0016) was an ISCIII Project

Association of CD2AP neuronal deposits with Braak neurofibrillary stage in Alzheimer’s disease

Alzheimer; CD2AP; Enfermedad de PickAlzheimer's disease; CD2AP; Pick's diseaseAlzheimer; CD2AP; Malaltia de PickGenome-wide association studies have described several genes as genetic susceptibility loci for Alzheimer's disease (AD). Among them, CD2AP encodes CD2-associated protein, a scaffold protein implicated in dynamic actin remodeling and membrane trafficking during endocytosis and cytokinesis. Although a clear link between CD2AP defects and glomerular pathology has been described, little is known about the function of CD2AP in the brain. The aim of this study was to analyze the distribution of CD2AP in the AD brain and its potential associations with tau aggregation and β-amyloid (Aβ) deposition. First, we performed immunohistochemical analysis of CD2AP expression in brain tissue from AD patients and controls (N = 60). Our results showed granular CD2AP immunoreactivity in the human brain endothelium in all samples. In AD cases, no CD2AP was found to be associated with Aβ deposits in vessels or parenchymal plaques. CD2AP neuronal inclusions similar to neurofibrillary tangles (NFT) and neuropil thread-like deposits were found only in AD samples. Moreover, immunofluorescence analysis revealed that CD2AP colocalized with pTau. Regarding CD2AP neuronal distribution, a hierarchical progression from the entorhinal to the temporal and occipital cortex was detected. We found that CD2AP immunodetection in neurons was strongly and positively associated with Braak neurofibrillary stage, independent of age and other pathological hallmarks. To further investigate the association between pTau and CD2AP, we included samples from cases of primary tauopathies (corticobasal degeneration [CBD], progressive supranuclear palsy [PSP], and Pick's disease [PiD]) in our study. Among these cases, CD2AP positivity was only found in PiD samples as neurofibrillary tangle-like and Pick body-like deposits, whereas no neuronal CD2AP deposits were detected in PSP or CBD samples, which suggested an association of CD2AP neuronal expression with 3R-Tau-diseases. In conclusion, our findings open a new road to investigate the complex cellular mechanism underlying the tangle conformation and tau pathology in the brain.This work was funded by Instituto de Salud Carlos III (ISCIII) (PI17/00275, PI20/00465), cofinanced by the European Regional Development Fund (FEDER). The Neurovascular Research Laboratory is part of the INVICTUS+ network, ISCIII, Spain (RD16/0019/0021). M.H.-G. is supported by the Miguel Servet Programme, ISCIII, Spain (CPII17/00010

Comparison of Plasma Lipoprotein Composition and Function in Cerebral Amyloid Angiopathy and Alzheimer’s Disease

Malaltia d'Alzheimer; Apolipoproteïnes; Angiopatia amiloide cerebralEnfermedad de Alzheimer; Apolipoproteínas; Angiopatía amiloide cerebralAlzheimer’s disease; Apolipoproteins; Cerebral amyloid angiopathyCerebral amyloid angiopathy (CAA) refers to beta-amyloid (Aβ) deposition in brain vessels and is clinically the main cause of lobar intracerebral hemorrhage (ICH). Aβ can also accumulate in brain parenchyma forming neuritic plaques in Alzheimer’s disease (AD). Our study aimed to determine whether the peripheral lipid profile and lipoprotein composition are associated with cerebral beta-amyloidosis pathology and may reflect biological differences in AD and CAA. For this purpose, lipid and apolipoproteins levels were analyzed in plasma from 51 ICH-CAA patients (collected during the chronic phase of the disease), 60 AD patients, and 60 control subjects. Lipoproteins (VLDL, LDL, and HDL) were isolated and their composition and pro/antioxidant ability were determined. We observed that alterations in the lipid profile and lipoprotein composition were remarkable in the ICH-CAA group compared to control subjects, whereas the AD group presented no specific alterations compared with controls. ICH-CAA patients presented an atheroprotective profile, which consisted of lower total and LDL cholesterol levels. Plasma from chronic ICH-CAA patients also showed a redistribution of ApoC-III from HDL to VLDL and a higher ApoE/ApoC-III ratio in HDL. Whether these alterations reflect a protective response or have a causative effect on the pathology requires further investigation.This research was funded by Instituto de Salud Carlos III (co-financed by the European Regional Development Fund FEDER “Una manera de hacer Europa”), grant numbers PI13/00364, PI16/00471, PI14/01134 and PI17/00275. A.R.-U. was funded by Instituto de Salud Carlos III predoctoral contract FI17/00031. The Neurovascular Research Laboratory is part of the INVICTUS+ network, ISCIII, Spain [RD16/0019/0021]. J.L.S.-Q. is a member of the CIBER of Diabetes and Metabolism (CIBERDEM), ISCIII, Spain. M.H.-G. is supported by the Miguel Servet programme, ISCIII, Spain [CPII17/00010]. A.R.-U., N.P., S.B. and J.L.S.-Q. are members of the Quality Research Group 2017-SGR-1149 from Generalitat de Catalunya. A.R.-U., N.P., S.B. and J.L.S.-Q. are members of the Group of Vascular Biology from the Spanish Atherosclerosis Society

MFG-E8 (LACTADHERIN): a novel marker associated with cerebral amyloid angiopathy

Malaltia d'Alzheimer; Biomarcadors; Microdissecció de captura làserAlzheimer's disease; Biomarkers; Laser capture microdissectionEnfermedad de Alzheimer; Biomarcadores; Microdisección por captura láserBrain accumulation of amyloid-beta (Aβ) is a crucial feature in Alzheimer´s disease (AD) and cerebral amyloid angiopathy (CAA), although the pathophysiological relationship between these diseases remains unclear. Numerous proteins are associated with Aβ deposited in parenchymal plaques and/or cerebral vessels. We hypothesized that the study of these proteins would increase our understanding of the overlap and biological differences between these two pathologies and may yield new diagnostic tools and specific therapeutic targets. We used a laser capture microdissection approach combined with mass spectrometry in the APP23 transgenic mouse model of cerebral-β-amyloidosis to specifically identify vascular Aβ-associated proteins. We focused on one of the main proteins detected in the Aβ-affected cerebrovasculature: MFG-E8 (milk fat globule-EGF factor 8), also known as lactadherin. We first validated the presence of MFG-E8 in mouse and human brains. Immunofluorescence and immunoblotting studies revealed that MFG-E8 brain levels were higher in APP23 mice than in WT mice. Furthermore, MFG-E8 was strongly detected in Aβ-positive vessels in human postmortem CAA brains, whereas MFG-E8 was not present in parenchymal Aβ deposits. Levels of MFG-E8 were additionally analysed in serum and cerebrospinal fluid (CSF) from patients diagnosed with CAA, patients with AD and control subjects. Whereas no differences were found in MFG-E8 serum levels between groups, MFG-E8 concentration was significantly lower in the CSF of CAA patients compared to controls and AD patients. Finally, in human vascular smooth muscle cells MFG-E8 was protective against the toxic effects of the treatment with the Aβ40 peptide containing the Dutch mutation. In summary, our study shows that MFG-E8 is highly associated with CAA pathology and highlights MFG-E8 as a new CSF biomarker that could potentially be used to differentiate cerebrovascular Aβ pathology from parenchymal Aβ deposition.This work was funded by the Instituto de Salud Carlos III (ISCIII), (PI20/00465), co-financed by the European Regional Development Fund (FEDER). The Neurovascular Research Laboratory is part of the INVICTUS + network, ISCIII, Spain (RD16/0019/0021). P.M. held a predoctoral fellowship from the Vall d’Hebron Research Institute. MMV is supported by the BIONIC project (no. 733050822, which has been made possible by ZonMW as part of ‘Memorabel’, the research and innovation program for dementia, as part of the Dutch national ‘Deltaplan for Dementia’:the CAFÉ project (the National Institutes of Health, USA, grant number 5R01NS104147-02), and a grant from the Selfridges Group Foundation (NR170024). The BIONIC project is a consortium of Radboudumc, LUMC, ADX Neurosciences, and Rhode Island University

Update on the Serum Biomarkers and Genetic Factors Associated with Safety and Efficacy of rt-PA Treatment in Acute Stroke Patients

An accurate understanding of the mechanisms underlying an individual's response to rt-PA treatment is critical to improve stroke patients' management. We thus reviewed the literature in order to identify biochemical and genetic factors that have been associated with safety and efficacy of rt-PA administration after stroke

Circulating AQP4 Levels in Patients with Cerebral Amyloid Angiopathy-Associated Intracerebral Hemorrhage

Cerebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage (ICH) in elderly patients. Growing evidence suggests a potential role of aquaporin 4 (AQP4) in amyloid-beta-associated diseases, including CAA pathology. Our aim was to investigate the circulating levels of AQP4 in a cohort of patients who had suffered a lobar ICH with a clinical diagnosis of CAA. AQP4 levels were analyzed in the serum of 60 CAA-related ICH patients and 19 non-stroke subjects by enzyme-linked immunosorbent assay (ELISA). The CAA-ICH cohort was divided according to the time point of the functional outcome evaluation: mid-term (12 +/- 18.6 months) and long-term (38.5 +/- 32.9 months) after the last ICH. Although no differences were found in AQP4 serum levels between cases and controls, lower levels were found in CAA patients presenting specific hemorrhagic features such as >= 2 lobar ICHs and >= 5 lobar microbleeds detected by magnetic resonance imaging (MRI). In addition, CAA-related ICH patients who presented a long-term good functional outcome had higher circulating AQP4 levels than subjects with a poor outcome or controls. Our data suggest that AQP4 could potentially predict a long-term functional outcome and may play a protective role after a lobar ICH