Plasma microglial-derived extracellular vesicles are increased in frail patients with Mild Cognitive Impairment and exert a neurotoxic effect

Extracellular vesicles (EVs) are mediators of cellular communication that can be released by almost all cell types in both physiological and pathological conditions and are present in most biological fluids. Such characteristics make them attractive in the research of biomarkers for age-related pathological conditions. Based on this, the aim of the present study was to examine the changes in EV concentration and size in the context of frailty, a geriatric syndrome associated with a progressive physical and cognitive decline. Specifically, total EVs and neural and microglial-derived EVs (NDVs and MDVs respectively) were investigated in plasma of frail and non-frail controls (CTRL), mild cognitive impairment (MCI) subjects, and in Alzheimer's disease (AD) patients. Results provided evidence that AD patients displayed diminished NDV concentration (3.61 × 10⁹ ± 1.92 × 10⁹ vs 7.16 × 10⁹ ± 4.3 × 10⁹ particles/ml) and showed high diagnostic performance. They are able to discriminate between AD and CTRL with an area under the curve of 0.80, a sensitivity of 78.95% and a specificity of 85.7%, considering the cut-off of 5.27 × 10⁹ particles/ml. Importantly, we also found that MDV concentration was increased in frail MCI patients compared to CTRL (5.89 × 10⁹ ± 3.98 × 10⁹ vs 3.16 × 10⁹ ± 3.04 × 10⁹ particles/ml, P < 0.05) and showed high neurotoxic effect on neurons. MDV concentration discriminate frail MCI vs non-frail CTRL (AUC = 0.76) with a sensitivity of 80% and a specificity of 70%, considering the cut-off of 2.69 × 10⁹ particles/ml. Altogether, these results demonstrated an alteration in NDV and MDV release during cognitive decline, providing important insight into the role of EVs in frailty status.

Inflammatory expression profile in peripheral blood mononuclear cells from patients with Nasu-Hakola Disease

Homozygous mutations in Triggering Receptor Expressed on Myeloid cells 2 gene (TREM2) are one of the major causes of Nasu Hakola Disease (NHD). We analysed Peripheral Blood Mononuclear Cells (PBMC) profile of 164 inflammatory factors in patients with NHD carrying the TREM2 Q33X mutation as compared with heterozygous and wild type individuals. Several molecules related to bone formation and angiogenesis were altered in NHD compared to non-carriers: Bone Morphogenetic Protein (BMP)-1 mRNA levels were significantly increased in PBMC (2.32 fold-increase; P = 0.01), as were Transforming Growth Factor Beta (TGFB)3 levels (1.51 fold-increase; P = 0.02). Conversely, CXCL5 and Pro Platelet Basic Protein (PPBP) were strongly downregulated (-28.26, -9.85 fold-decrease over non-carriers, respectively, P = 0.01), as well as Platelet Factor 4 Variant 1 (PF4V1; -41.44, P = 0.03). Among other inflammatory factors evaluated, Interleukin (IL)-15 and Tumor Necrosis Factor Superfamily Member (TNFSF)4 mRNA levels were decreased in NHD as compared with non-carriers (-2.25 and -3.87 fold-decrease, P = 0.01 and 0.001, respectively). In heterozygous individuals, no significant differences were observed, apart from IL-15 mRNA levels, that were decreased at the same extent as NHD (-2.05 fold-decrease over non-carriers, P = 0.002). We identified a signature in PBMC from patients with NHD consisting of strongly decreased mRNA levels of CXCL5, PPBP, PF4V1, mildly decreased IL-15 and TNFSF4 and mildly increased BMP-1 and TGFB3.

Inflammatory molecules in Frontotemporal Dementia: cerebrospinal fluid signature of progranulin mutation carriers

Mutations in progranulin gene (GRN) are one of the major causes of autosomal dominant Frontotemporal Lobar Degeneration (FTLD). Progranulin displays anti-inflammatory properties and is likely a ligand of Tumor Necrosis Factor (TNF) receptor 2, expressed on microglia. A few cytokines and chemokines are altered in cerebrospinal fluid (CSF) from patients with sporadic FTLD, whereas no information is available in familial cases. We evaluated, through BioPlex, levels of 27 inflammatory molecules, including cytokines, chemokines, and related receptors, in CSF and matched serum, from FTLD patients carrying GRN mutations as compared with sporadic FTLD with no GRN mutations and controls. Mean±SD Monocyte Chemoattractant Protein-1 (MCP-1) levels were significantly increased in CSF from sporadic FTLD patients as compared with controls (334.27±151.5 versus 159.7±49pg/ml; P⩽0.05). In GRN mutation carriers versus controls, CSF levels of MCP-1 were unchanged, whereas Interferon-γ-inducible protein-10 (IP-10) levels were increased (809.17±240.0 versus 436.61±202.5pg/ml; P=0.012). In the same group, TNFα and Interleukin (IL)-15 levels were decreased (3.18±1.41 versus 35.68±30.5pg/ml; P=0.013 and 9.34±5.54 versus 19.15±10.03pg/ml; P=0.023, respectively). Conversely, Regulated upon Activation, Normal T-cell Expressed, and Secreted (RANTES) levels were decreased in patients, with or without mutations, as compared with controls (4.63±3.30 and 2.58±20 versus 87.57±70pg/ml, respectively; P<0.05). Moreover, IP-10, IL-15 and RANTES CSF levels were not influenced by age, whereas MCP-1 levels increased with age (ρ=0.48; P=0.007). In conclusion, inflammatory de-regulation was observed in both sporadic FTLD and GRN carriers compared to controls, with a specific inflammatory profile for the latter group.

GenMapDB: a database of mapped human BAC clones

GenMapDB (http://genomics.med.upenn.edu/genmapdb) is a repository of human bacterial artificial chromosome (BAC) clones mapped by our laboratory to sequence-tagged site markers. Currently, GenMapDB contains over 3000 mapped clones that span 19 chromosomes, chromosomes 2, 4, 5, 9-22, X and Y. This database provides positional information about human BAC clones from the RPCI-11 human male BAC library. It also contains restriction fragment analysis data and end sequences of the clones. GenMapDB is freely available to the public. The main purpose of GenMapDB is to organize the mapping data and to allow the research community to search for mapped BAC clones that can be used in gene mapping studies and chromosomal mutation analysis projects.