Effect of blood collection tube containing protease inhibitors on the pre-analytical stability of Alzheimer's disease plasma biomarkers.

The reliability of plasma biomarkers of Alzheimer's disease (AD) can be compromised by protease-induced degradation. This can limit the feasibility of conducting plasma biomarker studies in environments that lack the capacity for immediate processing and appropriate storage of blood samples. We hypothesized that blood collection tube supplementation with protease inhibitors can improve the stability of plasma biomarkers at room temperatures (RT). In this study, we conducted a comparative analysis of blood biomarker stability in traditional ethylenediaminetetraacetic acid (EDTA) tubes versus BD™ P100 collection tubes, the latter being coated with a protease inhibitor cocktail. The stability of six plasma AD biomarkers was evaluated over time under RT conditions. We evaluated three experimental approaches. In Approach 1, pooled plasma samples underwent storage at RT for up to 96 h. In Approach 2, plasma samples isolated upfront from whole blood collected into EDTA or P100 tubes were stored at RT for 0 h or 24 h before biomarker measurements. In Approach 3, whole blood samples were collected into paired EDTA and P100 tubes, followed by storage at RT for 0 h or 24 h before isolating the plasma for analyses. Biomarkers were measured with Single Molecule Array (Simoa) and immunoprecipitation-mass spectrometry (IP-MS) assays. Both the IP-MS and Simoa methods revealed that the use of P100 tubes significantly improves the stability of Aß42 and Aß40 across all approaches. However, the Aß42/Aß40 ratio levels were significantly stabilized only in the IP-MS assay in Approach 3. No significant differences were observed in the levels of plasma p-tau181, GFAP, and NfL for samples collected using either tube type in any of the approaches. Supplementation of blood collection tubes with protease inhibitors could reduce the protease-induced degradation of plasma Aß42 and Aß40, and the Aß42/40 ratio for the IP-MS assay. These findings have crucial implications for preanalytical procedures, particularly in resource-limited settings.

T-cell immune profile in blood of systemic mastocytosis: Association with disease features.

BACKGROUND: Systemic mastocytosis (SM) is a heterogeneous disease characterized by an expansion of KIT-mutated mast cells (MC). KIT-mutated MC display activated features and release MC mediators that might act on the tumour microenvironment and other immune cells. Here, we investigated the distribution of lymphocyte subsets in blood of patients with distinct subtypes of SM and determined its association with other disease features. METHODS: We studied the distribution of TCD4+ and TCD4- cytotoxic cells and their subsets, as well as total NK- and B cells, in blood of 115 SM patients-38 bone marrow mastocytosis (BMM), 67 indolent SM (ISM), 10 aggressive SM (ASM)- and 83 age-matched healthy donors (HD), using spectral flow cytometry and the EuroFlow Immunomonitoring panel, and correlated it with multilineage KITD816V , the alpha-tryptasemia genotype (HαT) and the clinical manifestations of the disease. RESULTS: SM patients showed decreased counts (vs. HD) of TCD4- cytotoxic cells, NK cells and several functional subsets of TCD4+ cells (total Th1, Th2-effector memory, Th22-terminal effector and Th1-like Tregs), together with increased T-follicular-helper and Th1/Th17-like Treg counts, associated with different immune profiles per diagnostic subtype of SM, in multilineal versus MC-restricted KITD816V and in cases with a HαT+ versus HαT- genotype. Unique immune profiles were found among BMM and ISM patients with MC-restricted KITD816V who displayed HαT, anaphylaxis, hymenoptera venom allergy, bone disease, pruritus, flushing and GI symptoms. CONCLUSION: Our results reveal altered T- and NK-cell immune profiles in blood of SM, which vary per disease subtype, the pattern of involvement of haematopoiesis by KITD816V , the HαT genotype and specific clinical manifestations of the disease.

Genome-wide analysis identifies novel loci influencing plasma apolipoprotein E concentration and Alzheimer's disease risk.

The APOE 2/3/4 polymorphism is the greatest genetic risk factor for Alzheimer's disease (AD). This polymorphism is also associated with variation in plasma ApoE level; while APOE*4 lowers, APOE*2 increases ApoE level. Lower plasma ApoE level has also been suggested to be a risk factor for incident dementia. To our knowledge, no large genome-wide association study (GWAS) has been reported on plasma ApoE level. This study aimed to identify new genetic variants affecting plasma ApoE level as well as to test if baseline ApoE level is associated with cognitive function and incident dementia in a longitudinally followed cohort of the Ginkgo Evaluation of Memory (GEM) study. Baseline plasma ApoE concentration was measured in 3031 participants (95.4% European Americans (EAs)). GWAS analysis was performed on 2580 self-identified EAs where both genotype and plasma ApoE data were available. Lower ApoE concentration was associated with worse cognitive function, but not with incident dementia. As expected, the risk for AD increased from E2/2 through to E4/4 genotypes (P for trend = 4.8E-75). In addition to confirming the expected and opposite associations of APOE*2 (P = 4.73E-79) and APOE*4 (P = 8.73E-12) with ApoE level, GWAS analysis revealed nine additional independent signals in the APOE region, and together they explained about 22% of the variance in plasma ApoE level. We also identified seven new loci on chromosomes 1, 4, 5, 7, 11, 12 and 20 (P range = 5.49E-08 to 5.36E-10) that explained about 9% of the variance in ApoE level. Plasma ApoE level-associated independent variants, especially in the APOE region, were also associated with AD risk and amyloid deposition in the brain, indicating that genetically determined ApoE level variation may be a risk factor for developing AD. These results improve our understanding of the genetic determinants of plasma ApoE level and their potential value in affecting AD risk.

Genetic risk for attention-deficit/hyperactivity disorder predicts cognitive decline and development of Alzheimer's disease pathophysiology in cognitively unimpaired older adults.

Attention-deficit/hyperactivity disorder (ADHD) persists in older age and is postulated as a risk factor for cognitive impairment and Alzheimer's Disease (AD). However, these findings rely primarily on electronic health records and can present biased estimates of disease prevalence. An obstacle to investigating age-related cognitive decline in ADHD is the absence of large-scale studies following patients with ADHD into older age. Alternatively, this study aimed to determine whether genetic liability for ADHD, as measured by a well-validated ADHD polygenic risk score (ADHD-PRS), is associated with cognitive decline and the development of AD pathophysiology in cognitively unimpaired (CU) older adults. We calculated a weighted ADHD-PRS in 212 CU individuals without a clinical diagnosis of ADHD (55-90 years). These individuals had baseline amyloid-ß (Aß) positron emission tomography, longitudinal cerebrospinal fluid (CSF) phosphorylated tau at threonine 181 (p-tau181), magnetic resonance imaging, and cognitive assessments for up to 6 years. Linear mixed-effects models were used to test the association of ADHD-PRS with cognition and AD biomarkers. Higher ADHD-PRS was associated with greater cognitive decline over 6 years. The combined effect between high ADHD-PRS and brain Aß deposition on cognitive deterioration was more significant than each individually. Additionally, higher ADHD-PRS was associated with increased CSF p-tau181 levels and frontoparietal atrophy in CU Aß-positive individuals. Our results suggest that genetic liability for ADHD is associated with cognitive deterioration and the development of AD pathophysiology. Findings were mostly observed in Aß-positive individuals, suggesting that the genetic liability for ADHD increases susceptibility to the harmful effects of Aß pathology.

Coumarin-azasugar-benzyl conjugates as non-neurotoxic dual inhibitors of butyrylcholinesterase and cancer cell growth.

We have applied the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction to prepare a library of ten coumarin-azasugar-benzyl conjugates and two phthalimide-azasugar-benzyl conjugates with potential anti-Alzheimer and anti-cancer properties. The compounds were evaluated as cholinesterase inhibitors, demonstrating a general preference, of up to 676-fold, for the inhibition of butyrylcholinesterase (BuChE) over acetylcholinesterase (AChE). Nine of the compounds behaved as stronger BuChE inhibitors than galantamine, one of the few drugs in clinical use against Alzheimer's disease. The most potent BuChE inhibitor (IC50 = 74 nM) was found to exhibit dual activities, as it also showed high activity (GI50 = 5.6 ± 1.1 µM) for inhibiting the growth of WiDr (colon cancer cells). In vitro studies on this dual-activity compound on Cerebellar Granule Neurons (CGNs) demonstrated that it displays no neurotoxicity.

Coumarins-lipophilic cations conjugates: Efficient mitocans targeting carbonic anhydrases.

Being aware of the need to develop more efficient therapies against cancer, herein we disclose an innovative approach for the design of selective antiproliferative agents. We have accomplished the conjugation of a coumarin fragment with lipophilic cations (triphenylphosphonium salts, guanidinium) for providing mitochondriotropic agents that simultaneously target also carbonic anhydrases IX and XII, involved in the development and progression of cancer. The new compounds prepared herein turned out to be strong inhibitors of carbonic anhydrases IX and XII of human origin (low-to-mid nM range), also endowed with high selectivity, exhibiting negligible activity towards cytosolic CA isoforms. Key interactions with the enzyme were analysed using docking and molecular dynamics simulations. Regarding their in vitro antiproliferative activities, an increase of the tether length connecting both pharmacophores led to a clear improvement in potency, reaching the submicromolar range for the lead compounds, and an outstanding selectivity towards tumour cell lines (S.I. up to >357). Cytotoxic effects were also analysed on MDR cell lines under hypoxic and normoxic conditions. Chemoresistance exhibited by phosphonium salts, and not by guanidines, against MDR cells was based on the fact that the former were found to be substrates of P-glycoprotein (P-gp), the pump responsible for extruding foreign chemicals; this situation was reversed by administrating tariquidar, a third generation P-gp inhibitor. Moreover, phosphonium salts provoked a profound depolarization of mitochondria membranes from tumour cells, thus probably compromising their oxidative metabolism. To gain insight into the mode of action of title compounds, continuous live cell microscopy was employed; interestingly, this technique revealed two different antiproliferative mechanisms for both families of mitocans. Whereas phosphonium salts had a cytostatic effect, blocking cell division, guanidines led to cell death via apoptosis.

ATN cerebrospinal fluid biomarkers in dementia with Lewy bodies: Initial results from the United States Dementia with Lewy Bodies Consortium.

INTRODUCTION: The National Institute on Aging - Alzheimer's Association (NIA-AA) ATN research framework proposes to use biomarkers for amyloid (A), tau (T), and neurodegeneration (N) to stage individuals with AD pathological features and track changes longitudinally. The overall aim was to utilize this framework to characterize pre-mortem ATN status longitudinally in a clinically diagnosed cohort of dementia with Lewy bodies (DLB) and to correlate it with the post mortem diagnosis. METHODS: The cohort was subtyped by cerebrospinal fluid (CSF) ATN category. A subcohort had longitudinal data, and a subgroup was neuropathologically evaluated. RESULTS: We observed a significant difference in Aß42/40 after 12 months in the A+T- group. Post mortem neuropathologic analyses indicated that most of the p-Tau 181 positive (T+) cases also had a high Braak stage. DISCUSSION: This suggests that DLB patients who are A+ but T- may need to be monitored to determine whether they remain A+ or ever progress to T positivity. HIGHLIGHTS: Some A+T- DLB subjects transition from A+ to negative after 12-months. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Monitoring of the A+T- sub-type of DLB may be necessary.

KITD816V mutation in blood for the diagnostic screening of systemic mastocytosis and mast cell activation syndromes.

BACKGROUND: Current diagnostic algorithms for systemic mastocytosis (SM) rely on the detection of KITD816V in blood to trigger subsequent bone marrow (BM) investigations. METHODS: Here, we correlated the KITD816V mutational status of paired blood and BM samples from 368 adults diagnosed with mast cell activation syndrome (MCAS) and mastocytosis and determined the potential utility of investigating KITD816V in genomic DNA from blood-purified myeloid cell populations to increase diagnostic sensitivity. In a subset of 69 patients, we further evaluated the kinetics of the KITD816V cell burden during follow-up and its association with disease outcome. RESULTS: Our results showed a high correlation (P < .0001) between the KITD816V mutation burden in blood and BM (74% concordant samples), but with a lower mean of KITD816V-mutated cells in blood (P = .0004) and a high rate of discordant BM+ /blood- samples particularly among clonal MCAS (73%) and BM mastocytosis (51%), but also in cutaneous mastocytosis (9%), indolent SM (15%), and well-differentiated variants of indolent SM (7%). Purification of different compartments of blood-derived myeloid cells was done in 28 patients who were BM mast cell (MC)+ /blood- for KITD816V, revealing KITD816V-mutated eosinophils (56%), basophils (25%), neutrophils (29%), and/or monocytes (31%) in most (61%) patients. Prognostically, the presence of ≥3.5% KITD816V-mutated cells (P < .0001) and an unstable KITD816V mutation cell burden (P < .0001) in blood and/or BM were both associated with a significantly shortened progression-free survival (PFS). CONCLUSIONS: These results confirm the high specificity but limited sensitivity of KITD816V analysis in whole blood for the diagnostic screening of SM and other primary MCAS, which might be overcome by assessing the mutation in blood-purified myeloid cell populations.

Immune cell kinetics and antibody response in COVID-19 patients with low-count monoclonal B-cell lymphocytosis.

Low-count monoclonal B-cell lymphocytosis (MBLlo ) has been associated with an underlying immunodeficiency and has recently emerged as a new risk factor for severe COVID-19. Here, we investigated the kinetics of immune cell and antibody responses in blood during COVID-19 of MBLlo versus non-MBL patients. For this study, we analyzed the kinetics of immune cells in blood of 336 COVID-19 patients (74 MBLlo and 262 non-MBL), who had not been vaccinated against SARS-CoV-2, over a period of 43 weeks since the onset of infection, using high-sensitivity flow cytometry. Plasma levels of anti-SARS-CoV-2 antibodies were measured in parallel by ELISA. Overall, early after the onset of symptoms, MBLlo COVID-19 patients showed increased neutrophil, monocyte, and particularly, plasma cell (PC) counts, whereas eosinophil, dendritic cell, basophil, and lymphocyte counts were markedly decreased in blood of a variable percentage of samples, and with a tendency toward normal levels from week +5 of infection onward. Compared with non-MBL patients, MBLlo COVID-19 patients presented higher neutrophil counts, together with decreased pre-GC B-cell, dendritic cell, and innate-like T-cell counts. Higher PC levels, together with a delayed PC peak and greater plasma levels of anti-SARS-CoV-2-specific antibodies (at week +2 to week +4) were also observed in MBLlo patients. In summary, MBLlo COVID-19 patients share immune profiles previously described for patients with severe SARS-CoV-2 infection, associated with a delayed but more pronounced PC and antibody humoral response once compared with non-MBL patients.

Relationship between Helicobacter pylori and undifferentiated non-granulomatous anterior uveitis.

PURPOSE: The relationship of Helicobacter pylori infection with ocular diseases, including anterior uveitis, has been reported. The objective of this study was to determine the presence of anti-H. pylori IgG antibodies in patients with idiopathic non-granulomatous anterior uveitis and compare the results with a control group. METHODS: A prospective, comparative, and cross-sectional study was conducted. Patients with idiopathic granulomatous anterior uveitis and a group of control subjects were included. The presence of anti-H. pylori IgG antibodies was determined. The chi-square test was performed for comparative analysis with GraphPad Prism V5.0 software. RESULTS: Thirty patients with idiopathic non-granulomatous anterior uveitis and 35 control subjects were included. In the determination of anti-H. pylori IgG antibodies, 24 (80%) patients and 19 (54%) control subjects were positive. A significant difference (p = 0.0263) was found between the groups and an odds ratio (OR) of 3.37. CONCLUSIONS: A direct relationship was found between the presence of anti-H. pylori IgG antibodies and idiopathic non-granulomatous anterior uveitis. An association can be established between idiopathic non-granulomatous anterior uveitis and H. pylori infection, without this being a causal or physiopathogenic relationship.

Molecular Alumo- and Gallosilicate Hydrides Functionalized with Terminal M(NR2)3 and Bridging M(NR2)2 (M = Ti, Zr, Hf; R = Me, Et) Moieties.

A general synthetic strategy for the systematic synthesis of group 4 MIV heterometallic complexes LMIII(H)(µ-O)Si(µ-O)(OtBu)2}nMIV(NR2)4-n (L = {[HC{C(Me)N(2,6-iPr2C6H3)}2; MIII = Al or Ga; n = 1 or 2; MIV = Ti, Zr, Hf; R = Me, Et), based on alumo- or gallosilicate hydride ligands bearing a Si-OH moiety, is presented. The challenging isolation of these metalloligands involved two strategies. On the one hand, the acid-base reaction of LAlH2 with (HO)2Si(OtBu)2 yielded LAlH(µ-O)Si(OH)(OtBu)2 (1), while on the other hand, the oxidative addition of (HO)2Si(OtBu)2 to LGa produced the gallium analog (2). These metalloligands successfully stabilized two hydrogen atoms with different acid-base properties (MIII-H and SiO-H) in the same molecule. Reactivity studies between 1 and 2 and group 4 amides MIV(NR2)4 (MIV = Ti, Zr, Hf; R = Me, Et) and tuning the reactions conditions and stoichiometry led to isolation and structural characterization of heterometallic complexes 3-11 with a 1:1 or 2:1 metalloligand/MIV ratio. Notably, some of these molecular heterometallic silicate complexes stabilize for the first time terminal (O3Si-O-)MIV(NR2)3 moieties known from single-site silica-grafted species. Furthermore, the aluminum-containing heterometallic complexes possess Al-H vibrational energies similar to those reported for modified alumina surfaces, which makes them potentially suitable models for the proposed MIV species grafted onto silica/alumina surfaces with hydride and dihydride architectures.

Design and synthesis of sulfonamides incorporating a biotin moiety: Carbonic anhydrase inhibitory effects, antiproliferative activity and molecular modeling studies.

Sulfonamides constitute an important class of classical carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. Herein we have accomplished the conjugation of biotin with an ample number of sulfonamide motifs with the aim of testing them in vitro as inhibitors of the human carbonic anhydrase (hCA) isoforms I and II (cytosolic isozymes), as well as hCA IX and XII (transmembrane, tumor-associated enzymes). Most of these newly synthesized compounds exhibited interesting inhibition profiles, with activities in the nanomolar range. The presence of a 4-F-C6H4 moiety, also found in SLC-0111, afforded an excellent selectivity towards the tumor-associated hypoxia-induced hCA isoform XII with an inhibition constant (KI) of 4.5 nM. The 2-naphthyl derivative was the most potent inhibitor against hCA IX (KI = 6.2 nM), 4-fold stronger than AAZ (KI = 25 nM) with very good selectivity. Some compounds were chosen for antiproliferative activity testing against a panel of 3 human tumor cell lines, one compound showing anti-proliferative activity on glioblastoma, triple-negative breast cancer, and pancreatic carcinoma cell lines.

11C-PiB PET can underestimate brain amyloid-ß burden when cotton wool plaques are numerous.

Individuals with familial Alzheimer's disease due to PSEN1 mutations develop high cortical fibrillar amyloid-ß load but often have lower cortical 11C-Pittsburgh compound B (PiB) retention than Individuals with sporadic Alzheimer's disease. We hypothesized this is influenced by limited interactions of Pittsburgh compound B with cotton wool plaques, an amyloid-ß plaque type common in familial Alzheimer's disease but rare in sporadic Alzheimer's disease. Histological sections of frontal and temporal cortex, caudate nucleus and cerebellum were obtained from 14 cases with sporadic Alzheimer's disease, 12 cases with familial Alzheimer's disease due to PSEN1 mutations, two relatives of a PSEN1 mutation carrier but without genotype information and three non-Alzheimer's disease cases. Sections were processed immunohistochemically using amyloid-ß-targeting antibodies and the fluorescent amyloid stains cyano-PiB and X-34. Plaque load was quantified by percentage area analysis. Frozen homogenates from the same brain regions from five sporadic Alzheimer's disease and three familial Alzheimer's disease cases were analysed for 3H-PiB in vitro binding and concentrations of amyloid-ß1-40 and amyloid-ß1-42. Nine sporadic Alzheimer's disease, three familial Alzheimer's disease and three non-Alzheimer's disease participants had 11C-PiB PET with standardized uptake value ratios calculated using the cerebellum as the reference region. Cotton wool plaques were present in the neocortex of all familial Alzheimer's disease cases and one sporadic Alzheimer's disease case, in the caudate nucleus from four familial Alzheimer's disease cases, but not in the cerebellum. Cotton wool plaques immunolabelled robustly with 4G8 and amyloid-ß42 antibodies but weakly with amyloid-ß40 and amyloid-ßN3pE antibodies and had only background cyano-PiB fluorescence despite labelling with X-34. Relative to amyloid-ß plaque load, cyano-Pittsburgh compound B plaque load was similar in sporadic Alzheimer's disease while in familial Alzheimer's disease it was lower in the neocortex and the caudate nucleus. In both regions, insoluble amyloid-ß1-42 and amyloid-ß1-40 concentrations were similar in familial Alzheimer's disease and sporadic Alzheimer's disease groups, while 3H-PiB binding was lower in the familial Alzheimer's disease than the sporadic Alzheimer's disease group. Higher amyloid-ß1-42 concentration associated with higher 3H-PiB binding in sporadic Alzheimer's disease but not familial Alzheimer's disease. 11C-PiB retention correlated with region-matched post-mortem amyloid-ß plaque load; however, familial Alzheimer's disease cases with abundant cotton wool plaques had lower 11C-PiB retention than sporadic Alzheimer's disease cases with similar amyloid-ß plaque loads. PiB has limited ability to detect amyloid-ß aggregates in cotton wool plaques and may underestimate total amyloid-ß plaque burden in brain regions with abundant cotton wool plaques.

Gene-mapping study of extremes of cerebral small vessel disease reveals TRIM47 as a strong candidate.

Cerebral small vessel disease is a leading cause of stroke and a major contributor to cognitive decline and dementia, but our understanding of specific genes underlying the cause of sporadic cerebral small vessel disease is limited. We report a genome-wide association study and a whole-exome association study on a composite extreme phenotype of cerebral small vessel disease derived from its most common MRI features: white matter hyperintensities and lacunes. Seventeen population-based cohorts of older persons with MRI measurements and genome-wide genotyping (n = 41 326), whole-exome sequencing (n = 15 965), or exome chip (n = 5249) data contributed 13 776 and 7079 extreme small vessel disease samples for the genome-wide association study and whole-exome association study, respectively. The genome-wide association study identified significant association of common variants in 11 loci with extreme small vessel disease, of which the chr12q24.11 locus was not previously reported to be associated with any MRI marker of cerebral small vessel disease. The whole-exome association study identified significant associations of extreme small vessel disease with common variants in the 5' UTR region of EFEMP1 (chr2p16.1) and one probably damaging common missense variant in TRIM47 (chr17q25.1). Mendelian randomization supports the causal association of extensive small vessel disease severity with increased risk of stroke and Alzheimer's disease. Combined evidence from summary-based Mendelian randomization studies and profiling of human loss-of-function allele carriers showed an inverse relation between TRIM47 expression in the brain and blood vessels and extensive small vessel disease severity. We observed significant enrichment of Trim47 in isolated brain vessel preparations compared to total brain fraction in mice, in line with the literature showing Trim47 enrichment in brain endothelial cells at single cell level. Functional evaluation of TRIM47 by small interfering RNAs-mediated knockdown in human brain endothelial cells showed increased endothelial permeability, an important hallmark of cerebral small vessel disease pathology. Overall, our comprehensive gene-mapping study and preliminary functional evaluation suggests a putative role of TRIM47 in the pathophysiology of cerebral small vessel disease, making it an important candidate for extensive in vivo explorations and future translational work.

Biotinylated selenocyanates: Potent and selective cytostatic agents.

Most of the currently available cytotoxic agents for tackling cancer are devoid of selectivity, thus causing severe side-effects. This situation stimulated us to develop new antiproliferative agents with enhanced affinity towards tumour cells. We focused our attention on novel chalcogen-containing compounds (thiosemicarbazones, disulfides, selenoureas, thio- and selenocyanates), and particularly on selenium derivatives, as it has been documented that this kind of compounds might act as prodrugs releasing selenium-based reactive species on tumour cells. Particularly interesting in terms of potency and selectivity was a pharmacophore comprised by a selenocyanato-alkyl fragment connected to a p-phenylenediamine residue, where the nature of the second amino moiety (free, Boc-protected, enamine-protected) provided a wide variety of antiproliferative activities, ranging from the low micromolar to the nanomolar values. The optimized structure was in turn conjugated through a peptide linkage with biotin (vitamin B7), a cellular growth promoter, whose receptor is overexpressed in numerous cancer cells; the purpose was to develop a selective vector towards malignant cells. Such biotinylated derivative behaved as a very strong antiproliferative agent, achieving GI50 values in the low nM range for most of the tested cancer cells; moreover, it was featured with an outstanding selectivity, with GI50 > 100 µM against human fibroblasts. Mechanistic studies on the mode of inhibition of the biotinylated selenocyanate revealed (Annexin-V assay) a remarkable increase in the number of apoptotic cells compared to the control experiment; moreover, depolarization of the mitochondrial membrane was detected by flow cytometry analysis, and with fluorescent microscopy, what supports the apoptotic cell death. Prior to the apoptotic events, cytostatic effects were observed against SW1573 cells using label-free cell-living imaging; therefore, tumour cell division was prevented. Multidrug resistant cell lines exhibited a reduced sensitivity towards the biotinylated selenocyanate, probably due to its P-gp-mediated efflux. Remarkably, antiproliferative levels could be restored by co-administration with tariquidar, a P-gp inhibitor; this approach can, therefore, overcome multidrug resistance mediated by the P-gp efflux system.

Feasibility, safety, and tolerability of two modalities of plasma exchange with albumin replacement to treat elderly patients with Alzheimer's disease in the AMBAR study.

BACKGROUND: In the Alzheimer Management by Albumin Replacement (AMBAR) study, mild-to-moderate Alzheimer's disease (AD) patients were treated with a plasma exchange (PE) program. Feasibility and safety of PE in this specific population are poorly understood and were analyzed in detail in this study. METHODS: Qualified patients were treated with 6 weeks of weekly conventional therapeutic plasma exchange (TPE) with albumin replacement followed by monthly low-volume plasma exchange (LVPE) for 12 months. The patients were divided into four groups: placebo (sham PE treatment), low-albumin (20 g), low-albumin + intravenous immunoglobulin (IVIG) (10 g), and high-albumin (40 g) + IVIG (20 g). Adverse events (AEs) were recorded and analyzed for all PE treatment groups and PE modalities. RESULTS: PE procedure-related AEs were more common in the active treatment groups (16.9% out of 1283 TPE and 12.5% out of 2203 LVPE were associated with at least one AE, a similar rate than in other PE indications) than in the placebo group (0.7% out of 1223 sham PE). Percentage of procedures with at least one AEs was higher with central venous access compared to peripheral venous access in all three active treatment groups (20.1% vs 13.1%, respectively). CONCLUSION: The TPE and LVPE procedures used in the AMBAR study on mild-to-moderate AD population were as safe and feasible as in other therapeutic applications of PE or routine plasmapheresis.

Investigation of the enantioselectivity of acetylcholinesterase and butyrylcholinesterase upon inhibition by tacrine-iminosugar heterodimers.

The copper-catalysed azide-alkyne cycloaddition was applied to prepare three enantiomeric pairs of heterodimers containing a tacrine residue and a 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) or 1,4-dideoxy-1,4-imino-L-arabinitol (LAB) moiety held together via linkers of variable lengths containing a 1,2,3-triazole ring and 3, 4, or 7 CH2 groups. The heterodimers were tested as inhibitors of butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). The enantiomeric heterodimers with the longest linkers exhibited the highest inhibition potencies for AChE (IC50 = 9.7 nM and 11 nM) and BuChE (IC50 = 8.1 nM and 9.1 nM). AChE exhibited the highest enantioselectivity (ca. 4-fold). The enantiomeric pairs of the heterodimers were found to be inactive (GI50 > 100 µM), or to have weak antiproliferative properties (GI50 = 84-97 µM) against a panel of human cancer cells.

Meta-analysis of age-related cognitive decline reveals a novel locus for the attention domain and implicates a COVID-19-related gene for global cognitive function.

INTRODUCTION: Cognitive abilities have substantial heritability throughout life, as shown by twin- and population-based studies. However, there is limited understanding of the genetic factors related to cognitive decline in aging across neurocognitive domains. METHODS: We conducted a meta-analysis on 3045 individuals aged ≥65, derived from three population-based cohorts, to identify genetic variants associated with the decline of five neurocognitive domains (attention, memory, executive function, language, visuospatial function) and global cognitive decline. We also conducted gene-based and functional bioinformatics analyses. RESULTS: Apolipoprotein E (APOE)4 was significantly associated with decline of memory (p = 5.58E-09) and global cognitive function (p = 1.84E-08). We identified a novel association with attention decline on chromosome 9, rs6559700 (p = 2.69E-08), near RASEF. Gene-based analysis also identified a novel gene, TMPRSS11D, involved in the activation of SARS-CoV-2, to be associated with the decline in global cognitive function (p = 4.28E-07). DISCUSSION: Domain-specific genetic studies can aid in the identification of novel genes and pathways associated with decline across neurocognitive domains. HIGHLIGHTS: rs6559700 was associated with decline of attention. APOE4 was associated with decline of memory and global cognitive decline. TMPRSS11D, a gene involved in the activation of SARS-CoV-2, was implicated in global cognitive decline. Cognitive domain abilities had both unique and shared molecular pathways across the domains.

Air pollution and dementia in older adults in the Ginkgo Evaluation of Memory Study.

INTRODUCTION: Growing evidence implicates air pollution as a risk factor for dementia, but prior work is limited by challenges in diagnostic accuracy and assessing exposures in the decades prior to disease development. We evaluated the impact of long-term fine particulate matter (PM2.5 ) exposures on incident dementia (all-cause, Alzheimer's disease [AD], and vascular dementia [VaD]) in older adults. METHODS: A panel of neurologists adjudicated dementia cases based on extensive neuropsychological testing and magnetic resonance imaging. We applied validated fine-scale air pollutant models to reconstructed residential histories to assess exposures. RESULTS: An interquartile range increase in 20-year PM2.5 was associated with a 20% higher risk of dementia (95% confidence interval [CI]: 5%, 37%) and an increased risk of mixed VaD/AD but not AD alone. DISCUSSION: Our findings suggest that air pollutant exposures over decades contribute to dementia and that effects of current exposures may be experienced years into the future.

Serum NfL and GFAP are associated with incident dementia and dementia mortality in older adults: The cardiovascular health study.

INTRODUCTION: Circulating neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) have been independently associated with dementia risk. Their additive association, and their associations with dementia-specific mortality, have not been investigated. METHODS: We associated serum NfL, GFAP, total tau ,and ubiquitin carboxyl-terminal hydrolase-L1, measured in 1712 dementia-free adults, with 19-year incident dementia and dementia-specific mortality risk, and with 3-year cognitive decline. RESULTS: In adjusted models, being in the highest versus lowest tertile of NfL or GFAP associated with a hazard ratio (HR) of 1.49 (1.20-1.84) and 1.38 (1.15-1.66) for incident dementia, and 2.87 (1.79-4.61) and 2.76 (1.73-4.40) for dementia-specific mortality. Joint third versus first tertile exposure further increased risk; HR = 2.06 (1.60-2.67) and 9.22 (4.48-18.9). NfL was independently associated with accelerated cognitive decline. DISCUSSION: Circulating NfL and GFAP may, independently and jointly, provide useful clinical insight regarding dementia risk and prognosis.