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The multiplicity of systems affected in Alzheimer’s disease (AD) brains calls for multi-target therapies. Although mesenchymal stem cells (MSC) are promising candidates, their clinical application is limited because of risks related to their direct implantation in the host. This could be overcome by exploiting their paracrine action. We herein demonstrate that in vivo systemic administration of secretome collected from MSC exposed in vitro to AD mouse brain homogenates (MSC-CS), fully replicates the cell-mediated neuroreparative effects in APP/PS1 AD mice. We found a complete but transient memory recovery by 7 days, which vanished by 14 days, after a single MSC-CS intravenous administration in 12-month or 22–24-month-old mice. Treatment significantly reduced plaque load, microglia activation, and expression of cytokines in astrocytes in younger, but not aged, mice at 7 days. To optimize efficacy, we established a sustained treatment protocol in aged mice through intranasal route. Once-weekly intranasal administration of MSC-CS induced persistent memory recovery, with dramatic reduction of plaques surrounded by a lower density of β-amyloid oligomers. Gliosis and the phagocytic marker CD68 were decreased. We found a higher neuronal density in cortex and hippocampus, associated with a reduction in hippocampal shrinkage and a longer lifespan indicating healthier conditions of MSC-CS-treated compared to vehicle-treated APP/PS1 mice. Our data prove that MSC-CS displays a great multi-level therapeutic potential, and lay the foundation for identifying the therapeutic secretome bioreactors leading to the development of an efficacious multi-reparative cocktail drug, towards abrogating the need for MSC implantation and risks related to their direct use.

A 79 year old female individual presented to the hospital and complained of 1 month melena and anemia due to chronic gastrointestinal bleeding because of cavernous hemangiomatosis of the small bowel. After undergoing an initial video laparoscopic jejunal–ileal resection surgery 7 days after first hospitalization, given the persistence of anemia, she underwent laparotomic duodenojejunal resection surgery again 2 months later. Multiple cavernous hemangiomatosis is a rare vascular disease (7–10% of all benign small bowel tumors), and it often manifests with bleeding, which may be occult or massive; more rarely, it manifests with intestinal occlusion or perforation. Diagnoses often require the use of multiple radiological and endoscopic methods; video capsule endoscopy has significantly increased the diagnostic rate. The gold standard of treatment is surgical resection, whenever possible, balancing the need for radicality with the possible metabolic consequences of massive small intestine resections.

[...]a major obstacle that still hinders the broader success of nucleic acid-based therapies and vaccines lies in the inefficient delivery of these biopolymers to human cells, as well as in ensuring their subsequent intracellular release and optimal performance. In their research article,Bai et al.present a nucleoside-modified Rabies mRNA-lipid nanoparticle vaccine able to induce prolonged immune responses in animal models, whileRice at al.employ heterologous vaccination to elicit robust cellular immunogenicity with increased protection against the emerging variants of SARS-CoV-2 infection. [...]it is imperative to focus research efforts on the design of nucleic acids that can induce controlled inflammation in a limited manner, both temporally and anatomically. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher. 1TsengHFAckersonBKLuoYSyLSTalaricoCATianY.Effectiveness of mRNA-1273 against SARS-CoV-2 Omicron and Delta variants.Nat Med(2022)28(5):1063–71. doi:10.1038/s41591-022-01753-y 2JacksonLAAndersonEJRouphaelNGRobertsPCMakheneMColerRN.An mRNA Vaccine against SARS-CoV-2 - Preliminary Report.N Engl J Med(2020)383(20):1920–31. doi:10.1056/NEJMoa2022483 3KulkarniJAWitzigmannDThomsonSBChenSLeavittBRCullisPR.The current landscape of nucleic acid therapeutics.Nat Nanotechnol(2021)16(6):630–43. doi:10.1038/s41565-021-00898-0 4JohnsonMBChandlerMAfoninKA.Nucleic acid nanoparticles (NANPs) as molecular tools to direct desirable and avoid undesirable immunological effects.Adv Drug Deliver Rev(2021)173:427–38. doi:10.1016/j.addr.2021.04.011 5AfoninKADobrovolskaiaMAChurchGBatheM.Opportunities, barriers, and a strategy for overcoming translational challenges to therapeutic nucleic acid nanotechnology.ACS Nano(2020)14(8):9221–7. doi:10.1021/acsnano.0c04753 6LeppekKByeonGWKladwangWWayment-SteeleHKKerrCHXuAF.Combinatorial optimization of mRNA structure, stability, and translation for RNA-based therapeutics.Nat Commun(2022)13(1):1536. doi:10.1038/s41467-022-28776-w 7ZhangHZhangLLinAXuCLiZLiuK.Algorithm for optimized mRNA design improves stability and immunogenicity.Nature(2023). doi:10.1038/s41586-023-06127-z 8PulendranBSAPO'HaganDT.Emerging concepts in the science of vaccine adjuvants.Nat Rev Drug Discovery(2021)20(6):454–75. doi:10.1038/s41573-021-00163-y 9ChandlerMJainSHalmanJHongEDobrovolskaiaMAZakharovAV.Artificial immune cell, AI-cell, a new tool to predict interferon production by peripheral blood monocytes in response to nucleic acid nanoparticles.Small(2022)18(46):e2204941. doi:10.1002/smll.202204941 10HongEHalmanJRShahABKhisamutdinovEFDobrovolskaiaMAAfoninKA.Structure and composition define immunorecognition of nucleic acid nanoparticles.Nano Lett(2018)18(7):4309–21. doi:10.1021/acs.nanolett.8b01283 11ChandlerMRolbandLJohnsonMBShiDAvilaYICedroneE.Expanding structural space for immunomodulatory nucleic acid nanoparticles (Nanps) via spatial arrangement of their therapeutic moieties.Adv Funct Mater(2022)32(43):2205581. doi:10.1002/adfm.202205581 12JohnsonMBHalmanJRMillerDKCooperJSKhisamutdinovEFMarriottI.The immunorecognition, subcellular compartmentalization, and physicochemical properties of nucleic

The blood–brain barrier (BBB) is a highly selective barrier that strictly controls the passage of substances and cells into the brain, protecting it from potential harm while preserving homeostasis. It is composed of specialised endothelial cells (ECs), along with surrounding cells, such as pericytes and astrocytes. In glioblastoma (GBM), the most prevalent primary malignant brain tumour in adults, the BBB is heterogeneously dysfunctional. In the tumour microenvironment, regions enriched with glioblastoma stem cells (GSCs) are protected by an intact BBB. However, the influence of GSCs on BBB function remains largely unexplored. In this study, the impact of patient-derived GSC (PD GSC) secretomes on human brain capillary ECs has been investigated in vitro. Results showed that secretomes decrease the BBB permeability, leading to an increase of transendothelial electrical resistance and of tight junction protein claudin-5 (CLDN5) levels. Moreover, the receptor for advanced glycation endproducts (RAGE), which is involved in cancer and chemotherapy resistance, modulates CLDN5 expression by activating the pERK/ERK signaling pathway and influences junctional organization. These findings suggest a functional pathway through which PD GSC secretomes can modulate BBB permeability, potentially impacting therapeutic efficacy.

The characterization of nanoparticle-based drug-delivery systems represents a crucial step in achieving a comprehensive overview of their physical, chemical, and biological features and evaluating their efficacy and safety in biological systems. We propose Raman Spectroscopy (RS) for the characterization of liposomes (LPs) to be tested for the control of neuroinflammation and microglial dysfunctions in Glioblastoma multiforme and Alzheimer’s disease. Drug-loaded LPs were functionalized to cross the blood–brain barrier and to guarantee localized and controlled drug release. The Raman spectra of each LP component were used to evaluate their contribution in the LP Raman fingerprint. Raman data analysis made it possible to statistically discriminate LPs with different functionalization patterns, showing that each molecular component has an influence in the Raman spectrum of the final LP formulation. Moreover, CLS analysis on Raman data revealed a good level of synthetic reproducibility of the formulations and confirmed their stability within one month from their synthesis, demonstrating the ability of the technique to evaluate the efficacy of LP synthesis using small amount of sample. RS represents a valuable tool for a fast, sensitive and label free biochemical characterization of LPs that could be used for quality control of nanoparticle-based therapeutics.

Activation of the NLRP3 inflammasome in response to either exogenous (PAMPs) or endogenous (DAMPs) stimuli results in the production of IL-18, caspase-1 and IL-1β. These cytokines have a beneficial role in promoting inflammation, but an excessive activation of the inflammasome and the consequent constitutive inflammatory status plays a role in human pathologies, including Alzheimer’s disease (AD). Autophagic removal of NLRP3 inflammasome activators can reduce inflammasome activation and inflammation. Likewise, inflammasome signaling pathways regulate autophagy, allowing the development of inflammatory responses but preventing excessive and detrimental inflammation. Nanotechnology led to the development of liposome engineered nanovectors (NVs) that can load and carry drugs. We verified in an in vitro model of AD-associated inflammation the ability of Glibenclamide-loaded NVs (GNVs) to modulate the balance between inflammasome activation and autophagy. Human THP1dM cells were LPS-primed and oligomeric Aß-stimulated in the presence/absence of GNVs. IL-1β, IL-18 and activated caspase-1 production was evaluated by the Automated Immunoassay System (ELLA); ASC speck formation (a marker of NLRP3 activation) was analyzed by FlowSight Imaging flow-cytometer (AMNIS); the expression of autophagy targets was investigated by RT-PCR and Western blot (WB); and the modulation of autophagy-related up-stream signaling pathways and Tau phosphorylation were WB-quantified. Results showed that GNVs reduce activation of the NLRP3 inflammasome and prevent the Aß-induced phosphorylation of ERK, AKT, and p70S6 kinases, potentiating autophagic flux and counteracting Tau phosphorylation. These preliminary results support the investigation of GNVs as a possible novel strategy in disease and rehabilitation to reduce inflammasome-associated inflammation.

Objective The purpose of this study was to evaluate cholesterol esterification and HDL subclasses in plasma and cerebrospinal fluid (CSF) of Alzheimer’s disease (AD) patients. Methods The study enrolled 70 AD patients and 74 cognitively normal controls comparable for age and sex. Lipoprotein profile, cholesterol esterification, and cholesterol efflux capacity (CEC) were evaluated in plasma and CSF. Results AD patients have normal plasma lipids but significantly reduced unesterified cholesterol and unesterified/total cholesterol ratio. Lecithin:cholesterol acyltransferase (LCAT) activity and cholesterol esterification rate (CER), two measures of the efficiency of the esterification process, were reduced by 29% and 16%, respectively, in the plasma of AD patients. Plasma HDL subclass distribution in AD patients was comparable to that of controls but the content of small discoidal preβ-HDL particles was significantly reduced. In agreement with the reduced preβ-HDL particles, cholesterol efflux capacity mediated by the transporters ABCA1 and ABCG1 was reduced in AD patients’ plasma. The CSF unesterified to total cholesterol ratio was increased in AD patients, and CSF CER and CEC from astrocytes were significantly reduced in AD patients. In the AD group, a significant positive correlation was observed between plasma unesterified cholesterol and unesterified/total cholesterol ratio with Aβ 1-42 CSF content. Conclusion Taken together our data indicate that cholesterol esterification is hampered in plasma and CSF of AD patients and that plasma cholesterol esterification biomarkers (unesterified cholesterol and unesterified/total cholesterol ratio) are significantly associated to disease biomarkers (i.e., CSF Aβ 1-42 ).

The anti-hyperglycemic drug glibenclamide (Glb) might represent an interesting therapeutic option in human neurodegenerative diseases because of its anti-inflammatory activity and its ability to downregulate activation of the NLRP3 inflammasome. Bi-functionalized liposomes that can cross the blood–brain barrier (BBB) may be used to release Glb into the central nervous system (CNS), overcoming its poor solubility and bioavailability. Here, we analyzed in vitro the effect of Glb-loaded nanovectors (GNVs) and Glb itself on NLRP3 inflammasome activation using a lipopolysaccharide- and nigericine-activated THP-1 cell model. Apoptosis-associated speck-like protein containing a CARD (ASC) aggregation and NLRP3-related cytokine (IL-1β, caspase 1, and IL-18) production and gene expression, as well as the concentration of miR-223-3p and miR-7-1-5p, known to modulate the NLRP3 inflammasome, were evaluated in all conditions. Results showed that both GNVs and Glb reduced significantly ASC-speck oligomerization, transcription and translation of NLRP3, as well as the secretion of caspase 1 and IL-1β (p < 0.05 for all). Unexpectedly, GNVs/Glb significantly suppressed miR-223-3p and upregulated miR-7-1-5p expression (p < 0.01). These preliminary results thus suggest that GNVs, similarly to Glb, are able to dampen NLRP3 inflammasome activation, inflammatory cytokine release, and modulate miR-223-3p/miR-7-1-5p. Although the mechanisms underlying the complex relation among these elements remain to be further investigated, these results can open new roads to the use of GNVs as a novel strategy to reduce inflammasome activation in disease and rehabilitation.

Much evidence suggests a protective role of high-density lipoprotein (HDL) and its major apolipoprotein apoA-I, in Alzheimer's disease (AD). The biogenesis of nascent HDL derived from a first lipidation of apoA-I, which is synthesized by the liver and intestine but not in the brain, in a process mediated by ABCA1. The maturation of nascent HDL in mature spherical HDL is due to a subsequent lipidation step, LCAT-mediated cholesterol esterification, and the change of apoA-I conformation. Therefore, different subclasses of apoA-I-HDL simultaneously exist in the blood circulation. Here, we investigated if and how the lipidation state affects the ability of apoA-I-HDL to target and modulate the cerebral β-amyloid (Aβ) content from the periphery, that is thus far unclear. In particular, different subclasses of HDL, each with different apoA-I lipidation state, were purified from human plasma and their ability to cross the blood-brain barrier (BBB), to interact with Aβ aggregates, and to affect Aβ efflux across the BBB was assessed using a transwell system. The results showed that discoidal HDL displayed a superior capability to promote Aβ efflux (9 × 10 cm/min), when compared to apoA-I in other lipidation states. In particular, no effect on Aβ efflux was detected when apoA-I was in mature spherical HDL, suggesting that apoA-I conformation, and lipidation could play a role in Aβ clearance from the brain. Finally, when apoA-I folded its structure in discoidal HDL, rather than in spherical ones, it was able to cross the BBB and strongly destabilize the conformation of Aβ fibrils by decreasing the order of the fibril structure (-24%) and the β-sheet content (-14%). These data suggest that the extent of apoA-I lipidation, and consequently its conformation, may represent crucial features that could exert their protective role in AD pathogenesis.

Background: Inflammasomes regulate the activation of caspases resulting in inflammation; inflammasome activation is dysregulated in Alzheimer’s disease (AD) and plays a role in the pathogenesis of this condition. Glibenclamide, an anti-inflammatory drug, could be an interesting way to down-modulate neuroinflammation. Methods: In this pilot study we verified with ex vivo experiments whether a glibenclamide-loaded nanovector (GNV) could reduce the NLRP3-inflammasome cascade in cells of AD patients. Monocytes isolated from healthy controls (HC) and AD patients were cultured in medium, alone or stimulated with LPS + nigericin in presence/absence of GNV. ASC-speck positive cells and inflammasome-related genes, proteins, and miRNAs expressions were measured. The polymorphisms of ApoE (Apolipoprotein E), specifically rs7412 and rs429358, as well as those of NLRP3, namely rs35829419, rs10733113, and rs4925663, were also investigated. Results: Results showed that ASC-speck+ cells and Caspase-1, IL-1β, and IL-18 production was significantly reduced (p < 0.005 in all cases) by GNV in LPS + nigericin-stimulated cells of both AD and HC. Notably, the NLRP3 rs10733113 AG genotype was associated with excessive inflammasome-related gene and protein expression. GNV significantly down-regulates inflammasome activation in primary monocytes, at least at protein levels, and its efficacy seems to partially depend on the presence of the NLRP3 rs10733113 genotype. Conclusions: All together, these results showed that GNV is able to dampen inflammation and NLRP-3 inflammasome activation in an ex vivo monocyte model, suggesting a possible role for GNV in controlling AD-associated neuroinflammation.