Showing papers by "Laura Colombo published in 2022"

NMR-Driven Identification of Cinnamon Bud and Bark Components With Anti-Aβ Activity

Abstract: The anti-Alzheimer disease (AD) activity reported for an aqueous cinnamon bark extract prompted us to investigate and compare the anti-amyloidogenic properties of cinnamon extracts obtained from both bark and bud, the latter being a very little explored matrix. We prepared the extracts with different procedures (alcoholic, hydroalcoholic, or aqueous extractions). An efficient protocol for the rapid analysis of NMR spectra of cinnamon bud and bark extracts was set up, enabling the automatic identification and quantification of metabolites. Moreover, we exploited preparative reverse-phase (RP) chromatography to prepare fractions enriched in polyphenols, further characterized by UPLC-HR-MS. Then, we combined NMR-based molecular recognition studies, atomic force microscopy, and in vitro biochemical and cellular assays to investigate the anti-amyloidogenic activity of our extracts. Both bud and bark extracts showed a potent anti-amyloidogenic activity. Flavanols, particularly procyanidins, and cinnamaldehydes, are the chemical components of cinnamon hindering Aβ peptide on-pathway aggregation and toxicity in a human neuroblastoma SH-SY5Y cell line. Together with the previously reported ability to hinder tau aggregation and filament formation, these data indicate cinnamon polyphenols as natural products possessing multitarget anti-AD activity. Since cinnamon is a spice increasingly present in the human diet, our results support its use to prepare nutraceuticals useful in preventing AD through an active contrast to the biochemical processes that underlie the onset of this disease. Moreover, the structures of cinnamon components responsible for cinnamon anti-AD activities represent molecular templates for designing and synthesizing new anti-amyloidogenic drugs.

Micro- and Nanoplastics’ Effects on Protein Folding and Amyloidosis

Abstract: A significant portion of the world’s plastic is not properly disposed of and, through various processes, is degraded into microscopic particles termed micro- and nanoplastics. Marine and terrestrial faunae, including humans, inevitably get in contact and may inhale and ingest these microscopic plastics which can deposit throughout the body, potentially altering cellular and molecular functions in the nervous and other systems. For instance, at the cellular level, studies in animal models have shown that plastic particles can cross the blood–brain barrier and interact with neurons, and thus affect cognition. At the molecular level, plastics may specifically influence the folding of proteins, induce the formation of aberrant amyloid proteins, and therefore potentially trigger the development of systemic and local amyloidosis. In this review, we discuss the general issue of plastic micro- and nanoparticle generation, with a focus on their effects on protein folding, misfolding, and their possible clinical implications.

Alzheimer’s Disease Prevention through Natural Compounds: Cell-Free, In Vitro, and In Vivo Dissection of Hop (Humulus lupulus L.) Multitarget Activity

Abstract: The relevant social and economic costs associated with aging and neurodegenerative diseases, particularly Alzheimer’s disease (AD), entail considerable efforts to develop effective preventive and therapeutic strategies. The search for natural compounds, whose intake through diet can help prevent the main biochemical mechanisms responsible for AD onset, led us to screen hops, one of the main ingredients of beer. To explore the chemical variability of hops, we characterized four hop varieties, i.e., Cascade, Saaz, Tettnang, and Summit. We investigated the potential multitarget hop activity, in particular its ability to hinder Aβ1–42 peptide aggregation and cytotoxicity, its antioxidant properties, and its ability to enhance autophagy, promoting the clearance of misfolded and aggregated proteins in a human neuroblastoma SH-SY5Y cell line. Moreover, we provided evidence of in vivo hop efficacy using the transgenic CL2006Caenorhabditis elegans strain expressing the Aβ3–42 peptide. By combining cell-free and in vitro assays with nuclear magnetic resonance (NMR) and MS-based metabolomics, NMR molecular recognition studies, and atomic force microscopy, we identified feruloyl and p-coumaroylquinic acids flavan-3-ol glycosides and procyanidins as the main anti-Aβ components of hop.

Does slow release oral morphine have impact on craving and impulsivity in heroin dependent individuals?

Abstract: Craving and impulsivity are addiction components which explain why heroin-dependant individuals (HDI), continue using heroin despite not wanting to do so. Opioid maintenance treatment (OMT), such as slow-release oral morphine (SROM), is the most effective treatment for opioid dependence. However, the impact of SROM on craving and impulsivity remains unclear. In this observational study, 23 HDI receiving SROM, their usual OMT, took part in the experiment. Each of the participants filled in the perceived level of craving with a visual analog scale. Their impulsivity was assessed via three laboratory tasks, the stop-signal reaction time, the Balloon Analogue Risk Task and delay discounting. Each evaluation was performed before and after SROM administration. Craving was significantly reduced after administration of SROM (difference 2.83; P = 0.0010), whereas there were no significant differences in performance in the three laboratory tasks. In the long term, we observed an improvement on delay discounting correlated with the duration and dosage of SROM. The acute impact of SROM appears to significantly reduce craving, without impacting impulsivity. Observation of the correlation between delay discounting and the duration and dosage of OMT is of great interest and should be studied further.

I17 Sustained benefits of brain-permeable cholesterol-loaded nanoparticles in zQ175DN mouse model

Abstract:

Background

Huntington’s disease (HD) is associated with reduced synthesis of brain cholesterol (chol) and mounting evidence highlights the concept that strategies aimed at delivering chol to the brain is beneficial in HD. More recently, we demonstrated that the systemic administration of the most advanced formulation of brain-permeable chol-loaded nanoparticles (hybrid-g7-NPs-chol) prevents cognitive decline and ameliorates some motor defects in the fast-progressing R6/2 mouse model.

Aims and Methods

Here we employed the slowly progressing zQ175DN (delta neo) heterozygous (het) knock-in HD mouse model to explore the long-term potential of hybrid-g7-NPs-chol through the evaluation of cognitive and motor tasks, electrophysiological analysis, and neuropathological assays. Response of the immune system and histological analysis in all organs were also examined to explore potential side effects.

Results

By testing different treatment regimens, we demonstrated that one cycle of hybrid-g7-NPs-chol, either at pre-symptomatic or symptomatic stage, is sufficient to prevent or normalize several behavioral defects for a long time. More cycles of hybrid-g7-NPs-chol are needed to obtain lasting and complete therapeutical benefits without long-term side effects. Sustained chol delivery to the brain of zQ175DN mice also reduces mutant Huntingtin aggregates both in striatum and cortex and completely normalizes glutamatergic communication in the striatal medium spiny neurons compared to saline-treated HD mice.

Conclusions

Our results show that chol delivery through brain-permeable nanoparticles is a safe and versatile therapeutic option to reverse behavioral decline and HD-related neuropathological signs in a long-term manner, highlighting the potential to translate cholesterol-based strategies in HD patients.

Synaptic and functional alterations in the development of mutant huntingtin expressing hiPSC‐derived neurons

Abstract: Huntington’s disease (HD) is a monogenic disease that results in a combination of motor, psychiatric, and cognitive symptoms. It is caused by a CAG trinucleotide repeat expansion in the exon 1 of the huntingtin (HTT) gene, which results in the production of a mutant HTT protein (mHTT) with an extended polyglutamine tract (PolyQ). Severe motor symptoms are a hallmark of HD and typically appear during middle age; however, mild cognitive and personality changes often occur already during early adolescence. Wild-type HTT is a regulator of synaptic functions and plays a role in axon guidance, neurotransmitter release, and synaptic vesicle trafficking. These functions are important for proper synapse assembly during neuronal network formation. In the present study, we assessed the effect of mHTT exon1 isoform on the synaptic and functional maturation of human induced pluripotent stem cell (hiPSC)-derived neurons. We used a relatively fast-maturing hiPSC line carrying a doxycycline-inducible pro-neuronal transcription factor, (iNGN2), and generated a double transgenic line by introducing only the exon 1 of HTT, which carries the mutant CAG (mHTTEx1). The characterization of our cell lines revealed that the presence of mHTTEx1 in hiPSC-derived neurons alters the synaptic protein appearance, decreases synaptic contacts, and causes a delay in the development of a mature neuronal activity pattern, recapitulating some of the developmental alterations observed in HD models, nonetheless in a shorted time window. Our data support the notion that HD has a neurodevelopmental component and is not solely a degenerative disease.

D14 Plasma levels of 24S-hydroxycholesterol are reduced in Huntington disease subjects: preliminary results of a 2-year longitudinal study

Abstract:

Objectives

Brain cholesterol is produced in situ and its turn-over is ensured by the conversion into 24S-hydroxycholesterol (24-OHC) which can cross the blood-brain barrier. Brain biosynthesis was shown to be reduced in murine models of Huntington’s disease (HD) and 24-OHC plasma concentrations were found reduced in HD patients. We aimed to investigate 24-OHC longitudinal changes and correlate the plasma levels with disease progression, basal ganglia MRI volumes, and neurofilament concentrations.

Participants and Methods

We conducted a 2-year observational study in 78 HD subjects and 64 healthy controls. Cholesterol and its metabolites were measured using two different in-house developed and validated methods based on liquid chromatography and mass spectrometry. Fifty-eight subjects underwent 3T-MRI for brain morphometry. Neurofilament plasma measures are ongoing. HD subjects were classified using the novel Huntington Disease Integrated Staging System (HD-ISS).

Results

Twenty-one subjects were in stage 0-1; 11 in stage 2; and 46 in stage 3(a-c). Preliminary analyses of baseline data showed 24-OHC significantly reduced in stage 3b and 3c patients in comparison with controls (p=0.03; p<0.02 respectively). We also observed a trend of reduction of 24-OHC from prodromal disease stages (0-1) to the late manifest disease stages. 24-OHC levels were 40.+/-1.9 ng/ml (mean +/- SEM) in controls; 33.6+/-3.8 in HD-stage 0-1; 34.3+/-5.5 in HD-stage 2; 30.9+/-3.9 in HD-stage 3a; 29.3+/-2.5 in HD-stage 3b; and 23.3+/-1.9 in HD-stage 3c.

Conclusions

Monitoring 24-OHC plasma concentrations may contribute in following disease progression and may represent a valuable outcome measure in clinical trials testing cholesterol as a candidate drug in HD.