Brain inflammation co-localizes highly with tau in mild cognitive impairment due to early-onset Alzheimer's disease.

Brain inflammation, with an increased density of microglia and macrophages, is an important component of Alzheimer's disease (AD) and a potential therapeutic target. However, it is incompletely characterized, particularly in patients whose disease begins before the age of 65 years and, thus, have few co-pathologies. Inflammation has been usefully imaged with translocator protein (TSPO) positron emission tomography (PET), but most inflammation PET tracers cannot image subjects with a low-binder TSPO rs6971 genotype. In an important development, participants with any TSPO genotype can be imaged with a novel tracer, [11C]ER176, that has a high binding potential and a more favorable metabolite profile than other TSPO tracers currently available. We applied [11C]ER176 to detect brain inflammation in mild cognitive impairment (MCI) caused by early-onset AD. Furthermore, we sought to correlate the brain localization of inflammation, volume loss, elevated Aß and tau. We studied brain inflammation in 25 patients with early-onset amnestic MCI (average age 59 ± 4.5 years, 10 women) and 23 healthy controls (average age 65 ± 6.0 years, 12 women), both groups with a similar proportion of all three TSPO-binding affinities. [11C]ER176 total distribution volume (VT), obtained with an arterial input function, was compared across patients and controls using voxel-wise and region-wise analyses. In addition to inflammation PET, most MCI patients had Aß (n=23), and tau PET (n=21). For Aß and tau tracers, standard uptake value ratios (SUVRs) were calculated using cerebellar grey matter as region of reference. Regional correlations among the three tracers were determined. Data were corrected for partial volume effect. Cognitive performance was studied with standard neuropsychological tools. In MCI caused by early-onset AD, there was inflammation in the default network, reaching statistical significance in precuneus and lateral temporal and parietal association cortex bilaterally, and in the right amygdala. Topographically, inflammation co-localized most strongly with tau (r= 0.63 ± 0.24). This correlation was higher than the co-localization of Aß with tau (r= 0.55±0.25) and of inflammation with Aß (0.43±0.22). Inflammation co-localized least with atrophy (-0.29±0.26). These regional correlations could be detected in participants with any of the three rs6971 TSPO polymorphisms. Inflammation in AD-related regions correlated with impaired cognitive scores. Our data highlight the importance of inflammation, a potential therapeutic target, in the AD process. Furthermore, they support the notion that, as shown in experimental tissue and animal models, the propagation of tau in humans is associated with brain inflammation.

A Novel Body Mass Index-Based Thromboembolic Risk Score for Overweight Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND: A novel risk prediction model appears to be urgently required to improve the assessment of thrombotic risk in overweight patients with nonvalvular atrial fibrillation (NVAF). We developed a novel body mass index (BMI)-based thromboembolic risk score (namely AB2S score) for these patients. METHODS: A total of 952 overweight patients with NVAF were retrospectively enrolled in this study with a 12-month follow-up. The primary endpoint was 1-year systemic thromboembolism and the time to thrombosis (TTT). The candidate risk variables identified by logistic regression analysis were included in the final nomogram model to construct AB2S score. The measures of model fit were evaluated using area under the curve (AUC), C-statistic, and calibration curve. The performance comparison of the AB2S score to the CHADS2 and CHA2DS2-VASc score was performed in terms of the AUC and decision analysis curve (DAC). RESULTS: The AB2S score was constructed using 7 candidate risk variables, including a 3-category BMI (25 to 30, 30 to 34, or ≥35 kg/m2). It yielded a c-index of 0.885 (95% CI, 0.814-0.954) and an AUC of 0.885 (95% CI, 0.815-0.955) for predicting 1-year systemic thromboembolism in patients with NVAF. Compared to the CHADS2 score and CHA2DS2-VASc score, the AB2S score had greater AUC and DAC values in predicting the thromboembolic risk and better risk stratification in TTT (P <.0001, P =.082, respectively). CONCLUSION: Our results highlighted the importance of a BMI-based AB2S score in determining systemic thromboembolism risk in overweight patients with NVAF, which may aid in decision-making for these patients to balance the effectiveness of anticoagulation from the underlying thrombotic risk.

A retrospective cohort study of the effectiveness and safety of dabigatran versus rivaroxaban in overweight patients with nonvalvular atrial fibrillation.

BACKGROUND: Guidance for dabigatran and rivaroxaban in overweight patients diagnosed with non-valvular atrial fibrillation (NVAF) is still lacking. AIM: Compare the effectiveness and safety of dabigatran and rivaroxaban for the treatment of NVAF in the overweight population. METHOD: A total of 396 out of 1029 overweight patients with NVAF at Zhongshan Hospital, Fudan University, from January 2017 and December 2018 were retrospectively enrolled using propensity score matching analysis. The clinical outcomes were analyzed by chi-square test and Kaplan-Meier analyses. The risk of bleeding and thrombosis was assessed using a Cox regression analysis and validated using a nomogram model. RESULTS: In terms of effectiveness, the incidence of thrombosis events and the time to thrombosis were similar in the dabigatran and rivaroxaban groups (P > 0.05). Regarding safety, compared to dabigatran, the rivaroxaban group had a higher incidence of bleeding events (8.6% vs. 3.5%, χ2 = 4.435, P = 0.035), a shorter time to bleeding (11.3 ± 0.18 months vs. 11.6 ± 0.14 months, P = 0.038) and an increased risk of bleeding (hazard ratio HR = 2.452, 95% confidence interval CI 1.017-5.913, P = 0.046), especially in those patients with heart failure (HR = 3.207, 95% CI 1.183-8.694, P = 0.022). CONCLUSION: Dabigatran therapy was shown to be equally effective. It may be superior in reducing bleeding risk in an overweight population with NVAF than rivaroxaban. Further prospective studies are encouraged for analysis.

Investigating the Molecular Mechanism of Quercetin Protecting against Podocyte Injury to Attenuate Diabetic Nephropathy through Network Pharmacology, MicroarrayData Analysis, and Molecular Docking.

Quercetin (QUE), a health supplement, can improve renal function in diabetic nephropathy (DN) rats by ameliorating podocyte injury. Its clinical trial for renal insufficiency in advanced diabetes (NCT02848131) is currently underway. This study aimed to investigate the mechanism of QUE protecting against podocyte injury to attenuate DN through network pharmacology, microarray data analysis, and molecular docking. QUE-associated targets, genes related to both DN, and podocyte injury were obtained from different comprehensive databases and were intersected and analyzed to obtain mapping targets. Candidate targets were identified by constructing network of protein-protein interaction (PPI) of mapping targets and ranked to obtain key targets. The major pathways were obtained from Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) term enrichment analysis of candidate targets via ClueGO plug-in and R project software, respectively. Potential receptor-ligand interactions between QUE and key targets were evaluated via Autodocktools-1.5.6. 41. Candidate targets, of which three key targets (TNF, VEGFA, and AKT1), and the major AGE-RAGE signaling pathway in diabetic complications were ascertained and associated with QUE against podocyte injury in DN. Molecular docking models showed that QUE could closely bind to the key targets. This study revealed that QUE could protect against podocyte injury in DN through the following mechanisms: downregulating inflammatory cytokine of TNF, reducing VEGF-induced vascular permeability, inhibiting apoptosis by stimulating AKT1 phosphorylation, and suppressing the AGE-induced oxidative stress via the AGE-RAGE signaling pathway.

The PET tracer [11C]MK-6884 quantifies M4 muscarinic receptor in rhesus monkeys and patients with Alzheimer's disease.

Positron emission tomography (PET) ligands play an important role in the development of therapeutics by serving as target engagement or pharmacodynamic biomarkers. Here, we describe the discovery and translation of the PET tracer [11C]MK-6884 from rhesus monkeys to patients with Alzheimer's disease (AD). [3H]MK-6884/[11C]MK-6884 binds with high binding affinity and good selectivity to an allosteric site on M4 muscarinic cholinergic receptors (M4Rs) in vitro and shows a regional distribution in the brain consistent with M4R localization in vivo. The tracer demonstrates target engagement of positive allosteric modulators of the M4R (M4 PAMs) through competitive binding interactions. [11C]MK-6884 binding is enhanced in vitro by the orthosteric M4R agonist carbachol and indirectly in vivo by the acetylcholinesterase inhibitor donepezil in rhesus monkeys and healthy volunteers, consistent with its pharmacology as a highly cooperative M4 PAM. PET imaging of [11C]MK-6884 in patients with AD identified substantial regional differences quantified as nondisplaceable binding potential (BPND) of [11C]MK-6884. These results suggest that [11C]MK-6884 is a useful target engagement biomarker for M4 PAMs but may also act as a sensitive probe of neuropathological changes in the brains of patients with AD.

Microglia Activation in Basal Ganglia Is a Late Event in Huntington Disease Pathophysiology.

OBJECTIVE: To define the role played by microglia in different stages of Huntington disease (HD), we used the TSPO radioligand [11C]-ER176 and PET to evaluate microglial activation in relation to neurodegeneration and in relation to the clinical features seen at premanifest and manifest stages of the disease. METHODS: This is a cross-sectional study in which 18 subjects (6 controls, 6 premanifest, and 6 manifest HD gene carriers) underwent a [11C]-ER176 PET scan and an MRI for anatomic localization. Segmentation of regions of interest (ROIs) was performed, and group differences in [11C]-ER176 binding (used to evaluate the extent of microglial activation) were assessed by the standardized uptake value ratio (SUVR). Microglial activation was correlated with ROIs volumes, disease burden, and the scores obtained in the clinical scales. As an exploratory aim, we evaluated the dynamic functions of microglia in vitro, by using induced microglia-like (iMG) cells from peripheral blood monocytes. RESULTS: Individuals with manifest HD present higher [11C]-ER176 SUVR in both globi pallidi and putamina in comparison with controls. No differences were observed when we compared premanifest HD with controls or with manifest HD. We also found a significant correlation between increased microglial activation and cumulative disease burden, and with reduced volumes. iMG from controls, premanifest HD, and manifest HD patients showed similar phagocytic capacity. CONCLUSIONS: Altogether, our data demonstrate that microglial activation is involved in HD pathophysiology and is associated with disease progression.

Neuroinflammation is highest in areas of disease progression in semantic dementia.

Despite epidemiological and genetic data linking semantic dementia to inflammation, the topography of neuroinflammation in semantic dementia, also known as the semantic variant of primary progressive aphasia, remains unclear. The pathology starts at the tip of the left temporal lobe where, in addition to cortical atrophy, a strong signal appears with the tau PET tracer 18F-flortaucipir, even though the disease is not typically associated with tau but with TDP-43 protein aggregates. Here, we characterized the topography of inflammation in semantic variant primary progressive aphasia using high-resolution PET and the tracer 11C-PBR28 as a marker of microglial activation. We also tested the hypothesis that inflammation, by providing non-specific binding targets, could explain the 18F-flortaucipir signal in semantic variant primary progressive aphasia. Eight amyloid-PET-negative patients with semantic variant primary progressive aphasia underwent 11C-PBR28 and 18F-flortaucipir PET. Healthy controls underwent 11C-PBR28 PET (n = 12) or 18F-flortaucipir PET (n = 12). Inflammation in PET with 11C-PBR28 was analysed using Logan graphical analysis with a metabolite-corrected arterial input function. 18F-flortaucipir standardized uptake value ratios were calculated using the cerebellum as the reference region. Since monoamine oxidase B receptors are expressed by astrocytes in affected tissue, selegiline was administered to one patient with semantic variant primary progressive aphasia before repeating 18F-flortaucipir scanning to test whether monoamine oxidase B inhibition blocked flortaucipir binding, which it did not. While 11C-PBR28 uptake was mostly cortical, 18F-flortaucipir uptake was greatest in the white matter. The uptake of both tracers was increased in the left temporal lobe and in the right temporal pole, as well as in regions adjoining the left temporal pole such as insula and orbitofrontal cortex. However, peak uptake of 18F-flortaucipir localized to the left temporal pole, the epicentre of pathology, while the peak of inflammation 11C-PBR28 uptake localized to a more posterior, mid-temporal region and left insula and orbitofrontal cortex, in the periphery of the damage core. Neuroinflammation, greatest in the areas of progression of the pathological process in semantic variant primary progressive aphasia, should be further studied as a possible therapeutic target to slow disease progression.

Investigation into molecular mechanisms and high-frequency core TCM for pulmonary fibrosis secondary to COVID-19 based on network pharmacology and data mining.

BACKGROUND: The complication, pulmonary fibrosis (PF) secondary to COVID-19, may have a second wave of late mortality, given the huge number of individuals infected by COVID-19. However, the molecular mechanisms of PF secondary to COVID-19 haven't been fully elucidated, making the identification of novel strategies for targeted therapy challenging. This study aimed to systematically identify the molecular mechanisms and high-frequency core traditional Chinese medicine (TCM) targeting PF secondary to COVID-19 through network pharmacology and data mining. METHODS: The molecular mechanisms of PF secondary to COVID-19 were identified by mapping the COVID-19 differentially expressed gene and known targets associated with PF, protein-protein interactions network analysis, and enrichment pathway analysis; then the high-frequency core TCM targeting PF secondary to COVID-19 were identified by data mining and "Key targets related to PF secondary to COVID-19 - Ingredients" and "Key ingredients-key herbs" network analysis; and last we validated the interaction between the key ingredients and key targets by molecular docking. RESULTS: The molecular mechanisms of PF secondary to COVID-19 were mainly related to tumor necrosis factor (TNF) signaling pathway, cytokine-cytokine receptor interaction pathway, and NF-κB signaling pathway. Among these, cytokines interleukin 6 (IL-6), TNF, and IL-1ß were identified as the key targets associated with PF secondary to COVID-19. The high-frequency core TCM targeting these key targets were identified, including ingredients of quercetin, epigallocatechin-3-gallate, emodin, triptolide, resveratrol, and herb of Polygonum cuspidatum. Finally, our results were validated by quercetin and resveratrol both well docked to IL-6, TNF, and IL-1ß protein, with the estimated docking energy <0 kcal/mol. CONCLUSIONS: This study identified the cytokines-related molecular mechanisms of PF secondary to COVID-19, and the high-frequency core TCM against PF by targeting IL-6, TNF, and IL-1ß. Which provides new ideas for the discovery of small molecular compounds with potential therapeutic effects on PF secondary to COVID-19.

Parametric Mapping for TSPO PET Imaging with Spectral Analysis Impulsive Response Function.

PURPOSE: The aim of this study was to investigate the use of spectral analysis (SA) for voxel-wise analysis of TSPO PET imaging studies. TSPO PET quantification is methodologically complicated by the heterogeneity of TSPO expression and its cell-dependent modulation during neuroinflammatory response. Compartmental models to account for this complexity exist, but they are unreliable at the high noise typical of voxel data. On the contrary, SA is noise-robust for parametric mapping and provides useful information about tracer kinetics with a free compartmental structure. PROCEDURES: SA impulse response function (IRF) calculated at 90 min after tracer injection was used as main parameter of interest in 3 independent PET imaging studies to investigate its sensitivity to (1) a TSPO genetic polymorphism (rs6971) known to affect tracer binding in a cross-sectional analysis of healthy controls scanned with [11C]PBR28 PET; (2) TSPO density with [11C]PBR28 in a competitive blocking study with a TSPO blocker, XBD173; and (3) the higher affinity of a second radiotracer for TSPO, by using data from a head-to-head comparison between [11C]PBR28 and [11C]ER176 scans. RESULTS: SA-IRF produced parametric maps of visually good quality. These were sensitive to TSPO genotype (mean relative difference between high- and mixed-affinity binders = 25 %) and TSPO availability (mean signal displacement after 90 mg oral administration of XBD173 = 39 %). Regional averages of voxel-wise IRF estimates were strongly associated with regional total distribution volume (VT) estimated with a 2-tissue compartmental model with vascular compartment (Pearson's r = 0.86 ± 0.11) but less strongly with standard 2TCM-VT (Pearson's r = 0.76 ± 0.32). Finally, SA-IRF estimates for [11C]ER176 were significantly higher than [11C]PBR28 ones, consistent with the higher amount of specific binding of the former tracer. CONCLUSIONS: SA-IRF can be used for voxel-wise quantification of TSPO PET data because it generates high-quality parametric maps, it is sensitive to TSPO availability and genotype, and it accounts for the complexity of TSPO tracer kinetics with no additional assumptions.

Compound XiongShao Capsule ameliorates streptozotocin-induced diabetic peripheral neuropathy in rats via inhibiting apoptosis, oxidative - nitrosative stress and advanced glycation end products.

ETHNOPHARMACOLOGICAL RELEVANCE: Compound XiongShao Capsule (CXSC), a traditional herb formula, has been approved for using to treat diabetic peripheral neuropathy (DPN) by the Shanghai Food and Drug Administration, with significant efficacy in clinic. AIM OF THE STUDY: This study aimed to investigate the multidimensional pharmacological mechanisms and synergism of CXSC against DPN in rats. METHODS: The quality analysis of CXSC was performed by high-performance liquid chromatography (HPLC) and thin-layer chromatography. Rats with DPNinduced by streptozotocin/high-fat diet for 4 weeks were treated with CXSC at three doses (1.2 g/kg, 0.36 g/kg, and 0.12 g/kg), or epalrestat (15 mg/kg) daily for 8 weeks continuously. During the treatment period, body weight, serum glucose levels, and nerve function, including nerve conduction velocity (NCV), and mechanical and thermal hyperalgesia were tested and assessed every 4 weeks. In the 13th week, the histopathological examination in the sciatic nerve was performed using a transmission electron microscope. The expression of apoptosis-related proteins of BAX, BCL2, and caspase-3 in the sciatic nerve was examined using hematoxylin and eosin staining. The serum levels of advanced glycation end products (AGEs), oxidative-nitrosative stress biomarkers of superoxide dismutase (SOD), and nitric oxide synthase (NOS) were measured using a rat-specific ELISA kit. RESULTS: CXSC had no significant effect on body weight or serum glucose levels (P > 0.05), but it significantly improved mechanical hyperalgesia (F5,36 = 18.24, P < 0.0001), thermal hyperalgesia (F5,36 = 8.45, P < 0.0001), and NCV (motor NCV: F5,36 = 7.644, P < 0.0001, sensory NCV: F5,36 = 12.83, P < 0.0001). Besides, it maintained myelin and axonal structure integrity, downregulated the expression of apoptosis-related proteins in the sciatic nerve tissue, reduced AGEs and NOS levels, and enhanced antioxidant enzyme SOD activities in the serum. CONCLUSION: CXSC exerted neuroprotective effects against rats with DPN through multidimensional pharmacological mechanisms including antiapoptotic activity in the sciatic nerve and downregulation of the level of serum NOS, SOD and AGEs.

Shikonin induces tumor apoptosis in glioma cells via endoplasmic reticulum stress, and Bax/Bak mediated mitochondrial outer membrane permeability.

ETHNOPHARMACOLOGICAL RELEVANCE: Shikonin, one of the main active ingredients of Chinese herbal medicine Lithospermum erythrorhizon, has been widely used to treat various disease including virus infection and inflammation in clinical. Its anti-tumor activity has been recorded in "Chinese herbal medicine". Recently, some studies about its anti-glioma effects have been reported. However, little is known about the molecular pharmacological activity of Shikonin in glioma. AIM: This study aimed to systematically uncover and validate the pharmacological mechanism of Shikonin against glioma. MATERIAL AND METHODS: Network pharmacology approach, survival analysis, and Pearson co-expression analysis were performed to uncover and test the pharmacological mechanisms of Shikonin in glioma. Apoptosis assay, Caspase-3 activity assay and immunoblot analysis were practiced to validate the mechanisms. RESULTS: Network pharmacology results suggested, anti-glioma effect of Shikonin by interfering endoplasmic reticulum (ER) stress-mediated tumor apoptosis targeting Caspase-3, and Bax/Bak-induced mitochondrial outer membrane permeabilization (MOMP) triggering cancer cell apoptosis. Survival analysis suggested the association of CASP3 with glioma (P < 0.05). Pearson correlation analysis indicated possible interaction of CASP3 with PERK through positive feedback regulation. Shikonin or in combination with 14G2a induced cell apoptosis in oligodendroglioma Hs683 cells in a dose-dependent manner with at a maximum apoptosis rate of 33%-37.5%, and 73%-77% respectively. Immunoblot analysis showed that Shikonin increased Caspase-3 activity to about 4.29 times, and increased 9 times when it combined with 14G2a. Shikonin increased also the expression levels of the proteins PERK and CHOP by about 4.4 and 5.6 folds, respectively, when it combined with 14G2a. CONCLUSIONS: This study highlights the pharmacological mechanisms of Shikonin in the induction of tumor apoptosis in glioma cells.

Validation of the Key Active Ingredients and Anti-Inflammatory and Analgesic Effects of Shenjin Huoxue Mixture Against Osteoarthritis by Integrating Network Pharmacology Approach and Thin-Layer Chromatography Analysis.

BACKGROUND: Shenjin Huoxue Mixture (SHM), a classic traditional herb mixture has shown significant clinical efficacy against osteoarthritis (OA). Our previous experimental study has confirmed its anti-inflammatory and analgesic effect on acute soft tissue injury in rats, with the compound of glycyrrhizinate in SHM identified and the content of paeoniflorin in SHM determined by high-performance liquid chromatography (HPLC). However, the components and its pharmacological mechanisms of SHM against OA have not been systematically elucidated yet. Thus this study aimed to predict the key active ingredients and potential pharmacological mechanisms of SHM in the treatment of OA by network pharmacology approach and thin-layer chromatography (TLC) validation. METHODS: The active ingredients of SHM and their targets, as well as OA-related targets, were identified from databases. The key active ingredients were defined and ranked by the number of articles retrieved in PubMed using the keyword "(the active ingredients [Title/Abstract]) AND Osteoarthritis[Title/Abstract] ", and validated partially by TLC. The pharmacological mechanisms of SHM against OA were displayed by GO term and Reactome pathway enrichment analysis with Discovery Studio 3.0 software docking to testing the reliability. RESULTS: Finally, 16 key active ingredients were identified and ranked, including quercetin validated through TLC. Inflammatory response, IL-6 signaling pathway and toll-like receptor (TLR) cascades pathway were predicted as the main pharmacological mechanisms of SHM against OA. Especially, 12 out of 16 key active ingredients, including validated quercetin, were well docked to IL-6 proteins. CONCLUSION: Our results confirmed the anti-inflammatory and analgesic effect of SHM against OA through multiple components, multiple targets and multiple pathways, which revealed the theoretical basis of SHM against OA and may provide a new drug option for treating OA.

Identifying Synergistic Mechanisms of Multiple Ingredients in Shuangbai Tablets against Proteinuria by Virtual Screening and a Network Pharmacology Approach.

Shuangbai Tablets (SBT), a traditional herbal mixture, has shown substantial clinical efficacy. However, a systematic mechanism of its active ingredients and pharmacological mechanisms of action against proteinuria continues being lacking. A network pharmacology approach was effectual in discovering the relationship of multiple ingredients and targets of the herbal mixture. This study aimed to identify key targets, major active ingredients, and pathways of SBT against proteinuria by network pharmacology approach combined with thin layer chromatography (TLC). Human phenotype (HP) disease analysis, gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and molecular docking were used in this study. To this end, a total of 48 candidate targets of 118 active ingredients of SBT were identified. Network analysis showed PTGS2, ESR1, and NOS2 to be the three key targets, and beta-sitosterol, quercetin, and berberine were the three major active ingredients; among them one of the major active ingredients, quercetin, was discriminated by TLC. These results of the functional enrichment analysis indicated that the most relevant disease including these 48 candidate proteins is proteinuria, SBT treated proteinuria by sympathetically regulating multiple biological pathways, such as the HIF-1, RAS, AGE-RAGE, and VEGF signaling pathways. Additionally, molecular docking validation suggested that major active ingredients of SBT were capable of binding to HIF-1A and VEGFA of the main pathways. Consequently, key targets, major active ingredients, and pathways based on data analysis of SBT against proteinuria were systematically identified confirming its utility and providing a new drug against proteinuria.

Multimodal 18F-AV-1451 and MRI Findings in Nonfluent Variant of Primary Progressive Aphasia: Possible Insights on Nodal Propagation of Tau Protein Across the Syntactic Network.

Although abnormally folded tau protein has been found to self-propagate from neuron to connected neuron, similar propagation through human brain networks has not been fully documented. We studied tau propagation in the left hemispheric syntactic network, which comprises an anterior frontal node and a posterior temporal node connected by the white matter of the left arcuate fasciculus. This network is affected in the nonfluent variant of primary progressive aphasia, a neurodegenerative disorder with tau accumulation. Methods: Eight patients with the nonfluent variant of primary progressive aphasia (age, 67.0 ± 7.4 y; 4 women) and 8 healthy controls (age, 69.6 ± 7.0 y; 4 women) were scanned with 18F-AV-1451 tau PET to determine tau deposition in the brain and with MRI to determine the fractional anisotropy of the arcuate fasciculus. Normal syntactic network characteristics were confirmed with structural MRI diffusion imaging in our healthy controls and with blood oxygenation level-dependent functional imaging in 35 healthy participants from the Alzheimer Disease Neuroimaging Initiative database. Results: Language scores in patients indicated dysfunction of the anterior node. 18F-AV-1451 deposition was greatest in the 2 nodes of the syntactic network. The left arcuate fasciculus had decreased fractional anisotropy, particularly near the anterior node. Normal MRI structural connectivity from an area similar to the one containing tau in the anterior frontal node projected to an area similar to the one containing tau in the patients in the posterior temporal node. Conclusion: Tau accumulation likely started in the more affected anterior node and, at the disease stage at which we studied these patients, appeared as well in the brain region (in the temporal lobe) spatially separate from but most connected with it. The arcuate fasciculus, connecting both of them, was most severely affected anteriorly, as would correspond to a loss of axons from the anterior node. These findings are suggestive of tau propagation from node to connected node in a natural human brain network and support the idea that neurons that wire together die together.

Head-to-head comparison of 11C-PBR28 and 11C-ER176 for quantification of the translocator protein in the human brain.

INTRODUCTION: 11C-ER176 is a new PET tracer to quantify the translocator protein (TSPO), a biomarker for inflammation. The aim of this study was to perform a head-to-head comparison between 11C-ER176 and the widely used 11C-PBR28. METHODS: Seven healthy volunteers had a 90-min PET scan and metabolite-corrected arterial input function with 11C-PBR28 in the morning and 11C-ER176 in the afternoon. Binding was quantified at the regional level in terms of VT with a two-tissue compartmental model. By using VND values from the literature obtained with pharmacological blockade, we derived the binding potential BPND for both tracers. RESULTS: 11C-ER176 was more stable in arterial blood than 11C-PBR28 (the percentages of unmetabolized parent in plasma at 90 min were 29.0 ± 8.3% and 8.8 ± 2.9% respectively). The brain time-activity curves for both tracers were well fitted by the two-tissue model, but 11C-ER176 had higher VT values than 11C-PBR28 (5.74 ± 1.54 vs 4.43 ± 1.99 ml/cm3) and a lower coefficient of variation. The BPND of 11C-ER176 was more than 4 times larger than that of 11C-PBR28 for high-affinity binders, and more than 9 times larger for mixed-affinity binders. CONCLUSION: 11C-ER176 displays a higher binding potential and a smaller variability of VT values. Thanks to these characteristics, clinical studies performed with 11C-ER176 are expected to have higher statistical power and thus require fewer subjects.

Identify the Key Active Ingredients and Pharmacological Mechanisms of Compound XiongShao Capsule in Treating Diabetic Peripheral Neuropathy by Network Pharmacology Approach.

Compound XiongShao Capsule (CXSC), a traditional herb mixture, has shown significant clinical efficacy against diabetic peripheral neuropathy (DPN). However, its multicomponent and multitarget features cause difficulty in deciphering its molecular mechanisms. Our study aimed to identify the key active ingredients and potential pharmacological mechanisms of CXSC in treating DPN by network pharmacology and provide scientific evidence of its clinical efficacy. CXSC active ingredients were identified from both the Traditional Chinese Medicine Systems Pharmacology database, with parameters of oral bioavailability ≥ 30% and drug-likeness ≥ 0.18, and the Herbal Ingredients' Targets (HIT) database. The targets of those active ingredients were identified using ChemMapper based on 3D-structure similarity and using HIT database. DPN-related genes were acquired from microarray dataset GSE95849 and five widely used databases (TTD, Drugbank, KEGG, DisGeNET, and OMIM). Next, we obtained candidate targets with therapeutic effects against DPN by mapping active ingredient targets and DPN-related genes and identifying the proteins interacting with those candidate targets using STITCH 5.0. We constructed an "active ingredients-candidate targets-proteins" network using Cytoscape 3.61 and identified key active ingredients and key targets in the network. We identified 172 active ingredients in CXSC, 898 targets of the active ingredients, 110 DPN-related genes, and 38 candidate targets with therapeutic effects against DPN. Three key active ingredients, namely, quercetin, kaempferol, and baicalein, and 25 key targets were identified. Next, we input all key targets into ClueGO plugin for KEGG enrichment and molecular function analyses. The AGE-RAGE signaling pathway in diabetic complications and MAP kinase activity were determined as the main KEGG pathway and molecular function involved, respectively. We determined quercetin, kaempferol, and baicalein as the key active ingredients of CXSC and the AGE-RAGE signaling pathway and MAP kinase activity as the main pharmacological mechanisms of CXSC against DPN, proving the clinical efficacy of CXSC against DPN.

Head-to-Head Comparison of 11C-PBR28 and 18F-GE180 for Quantification of the Translocator Protein in the Human Brain.

18F-GE180 is a third-generation PET tracer for quantifying the translocator protein (TSPO), a biomarker for inflammation. The aim of this study was to perform a head-to-head comparison of 18F-GE180 and the well-established TSPO tracer 11C-PBR28 by scanning with both tracers during the same day in the same subjects. Methods: Five subjects underwent a 90-min PET scan with 11C-PBR28 in the morning and 18F-GE180 in the afternoon. A metabolite-corrected arterial input function was obtained in each subject for both tracers, and the brain uptake was quantified with a 2-tissue-compartment model. Results: The rate of metabolism of 18F-GE180 in arterial blood was slower than that of 11C-PBR28 (the percentages of nonmetabolized parent in plasma at 90 min were 74.9% ± 4.15% [mean ± SD] and 11.2% ± 1.90%, respectively). The plasma free fractions were similar for both tracers: 3.5% ± 1.1% for 18F-GE180 and 4.1% ± 1.1% for 11C-PBR28. The average total volume of distribution (VT) of 18F-GE180 was about 20 times smaller than that of 11C-PBR28 (0.15 ± 0.03 mL/cm3 for 18F-GE180 and 3.27 ± 0.66 mL/cm3 for 11C-PBR28). 18F-GE180 was characterized by poor transfer from the vascular compartment to the brain (its plasma-to-tissue rate constant [K1] was about 10 times smaller than that of 11C-PBR28). Moreover, kinetic modeling was more difficult with 18F-GE180, as its VT values were identified with a lower precision than those of 11C-PBR28 and outlying values were more frequent. Conclusion: The VT of 18F-GE180 was about 20 times smaller than that of 11C-PBR28 because of low penetration into the brain from the vascular compartment. In addition, kinetic modeling of 18F-GE180 was more challenging than that of 11C-PBR28. Therefore, compared with 11C-PBR28, 18F-GE180 had unfavorable characteristics for TSPO imaging of the brain.

Cu2+-labeled dansyl compounds as fluorescent and PET probes for imaging apoptosis.

Compound DNSTT-Cu2+, a novel chelate of Cu2+ with DOTA conjugated to a fluorescent dansyl fragment, is developed for imaging cell apoptosis. Apoptotic U-87MG cells could be selectively visualized by the fluorescence of DNSTT-Cu2+ from cytoplasm of cells, confirmed by the fluorescence of apoptosis cells co-labeled with Alexa Fluor 568-labeled annexin V, a conventional probe for selectively labeling membranes of apoptosis cells. A radioactive 64Cu2+ analog, DNSTT-64Cu2+, was easily synthesized, providing a potential PET probe for imaging apoptosis in vivo.

Blood pressure is associated with higher brain amyloid burden and lower glucose metabolism in healthy late middle-age persons.

Epidemiological studies suggest that elevated blood pressure (BP) in midlife is associated with increased risk of Alzheimer's disease (AD) in late life. In this preliminary study, we investigated the extent to which BP measurements are related to positron emission tomography (PET) measurements of fibrillar amyloid-beta burden using Pittsburgh Compound-B (PiB) and fluorodeoxyglucose (FDG) PET measures of cerebral metabolic rate for glucose metabolism (CMRgl) in cognitively normal, late middle-aged to older adult apolipoprotein E (APOE) ε4 homozygotes, heterozygotes and noncarriers. PiB PET results revealed that systolic BP (SBP) and pulse pressure (PP) were each positively correlated with cerebral-to-cerebellar PiB distribution volume ratio (DVR) in frontal, temporal, and posterior-cingulate/precuneus regions, whereas no significant positive correlations were found between PiB distribution volume ratios and diastolic BP (DBP). FDG PET results revealed significant inverse correlations between each of the BP measures and lower glucose metabolism in frontal and temporal brain regions. These preliminary findings provide additional evidence that higher BP, likely a reflection of arterial stiffness, during late midlife may be associated with increased risk of presymptomatic AD.

Fibrillar amyloid-beta burden in cognitively normal people at 3 levels of genetic risk for Alzheimer's disease.

Fibrillar amyloid-beta (Abeta) is found in the brains of many cognitively normal older people. Whether or not this reflects a predisposition to Alzheimer's disease (AD) is unknown. We used Pittsburgh Compound B (PiB) PET to characterize the relationship between fibrillar Abeta burden and this predisposition in cognitively normal older people at 3 mean levels of genetic risk for AD. Dynamic PiB PET scans, the Logan method, statistical parametric mapping, and automatically labeled regions of interest (ROIs) were used to characterize and compare cerebral-to-cerebellar PIB distribution volume ratios, reflecting fibrillar Abeta burden, in 28 cognitively normal persons (mean age, 64 years) with a reported family history of AD and 2 copies, 1 copy, and no copies of the apolipoprotein E (APOE) epsilon4 allele. The 8 epsilon4 homozygotes, 8 heterozygotes, and 12 noncarriers did not differ significantly in terms of age, sex, or cognitive scores. Fibrillar Abeta was significantly associated with APOE epsilon4 carrier status and epsilon4 gene dose in AD-affected mean cortical, frontal, temporal, posterior cingulate-precuneus, parietal, and basal ganglia ROIs, and was highest in an additional homozygote who had recently developed mild cognitive impairment. These findings suggest that fibrillar Abeta burden in cognitively normal older people is associated with APOE epsilon4 gene dose, the major genetic risk factor for AD. Additional studies are needed to track fibrillar Abeta accumulation in persons with different kinds and levels of AD risk; to determine the extent to which fibrillar Abeta, alone or in combination with other biomarkers and risk factors, predicts rates of cognitive decline and conversion to clinical AD; and to establish the role of fibrillar Abeta imaging in primary prevention trials.