Stereochemical Behavior of Pyrrolo-Pyrazole Peptidomimetics Promoting Phase-Selective Supramolecular Organogels

Supramolecular gels were developed by taking advantage of an assembly of small dipeptides containing pyrrolo-pyrazole scaffolds. The dipeptides were prepared through a robust and ecofriendly synthetic approach from the commercially available starting materials of diazoalkanes and maleimides. By playing with the functionalization of the scaffold, the choice of the natural amino acid, and the stereochemistry, we were able to obtain phase-selective gels. In particular, one peptidomimetic showed gelation ability and thermoreversibility in aromatic solvents at very low concentrations. Rheology tests showed a typical viscoelastic solid profile, indicating the formation of strong gels that were stable under high mechanical deformation. NMR studies were performed, allowing us to determine the conformational and stereochemical features at the base of the supramolecular interactions.

Smart Electrospun Nanofibers from Short Peptidomimetics Based on Pyrrolo-pyrazole Scaffold

We prepared a small library of short peptidomimetics based on 3-pyrrolo-pyrazole carboxylate, a non-coded γ-amino acid, and glycine or alanine. The robust and eco-friendly synthetic approach adopted allows to obtain the dipeptides in two steps from commercial starting materials. This gives the possibility to shape these materials by electrospinning into micro- and nanofibers, in amounts required to be useful for coating surfaces of biomedical relevance. To promote high quality of electrospun fibers, different substitution patterns were evaluated, all for pure peptide fibers, free of any polymer or additive. The best candidate, which affords a homogeneous fibrous matrix, was prepared in larger amounts, and its biocompatibility was verified. This successful work is the first step to develop a new biomaterial able to produce pristine peptide-based nanofibers to be used as helpful component or stand-alone scaffolds for tissue engineering or for the surface modification of medical devices.

Spatial Multiomics of Lipids, N-Glycans, and Tryptic Peptides on a Single FFPE Tissue Section

Mass spectrometry imaging (MSI) is an emerging technology that is capable of mapping various biomolecules within their native spatial context, and performing spatial multiomics on formalin-fixed paraffin-embedded (FFPE) tissues may further increase the molecular characterization of pathological states. Here we present a novel workflow which enables the sequential MSI of lipids, N-glycans, and tryptic peptides on a single FFPE tissue section and highlight the enhanced molecular characterization that is offered by combining the multiple spatial omics data sets. In murine brain and clear cell renal cell carcinoma (ccRCC) tissue, the three molecular levels provided complementary information and characterized different histological regions. Moreover, when the spatial omics data was integrated, the different histopathological regions of the ccRCC tissue could be better discriminated with respect to the imaging data set of any single omics class. Taken together, these promising findings demonstrate the capability to more comprehensively map the molecular complexity within pathological tissue.

Cytomolecular Classification of Thyroid Nodules Using Fine-Needle Washes Aspiration Biopsies

Fine-needle aspiration biopsies (FNA) represent the gold standard to exclude the malignant nature of thyroid nodules. After cytomorphology, 20–30% of cases are deemed “indeterminate for malignancy” and undergo surgery. However, after thyroidectomy, 70–80% of these nodules are benign. The identification of tools for improving FNA’s diagnostic performances is explored by matrix-assisted laser-desorption ionization mass spectrometry imaging (MALDI-MSI). A clinical study was conducted in order to build a classification model for the characterization of thyroid nodules on a large cohort of 240 samples, showing that MALDI-MSI can be effective in separating areas with benign/malignant cells. The model had optimal performances in the internal validation set (n = 70), with 100.0% (95% CI = 83.2–100.0%) sensitivity and 96.0% (95% CI = 86.3–99.5%) specificity. The external validation (n = 170) showed a specificity of 82.9% (95% CI = 74.3–89.5%) and a sensitivity of 43.1% (95% CI = 30.9–56.0%). The performance of the model was hampered in the presence of poor and/or noisy spectra. Consequently, restricting the evaluation to the subset of FNAs with adequate cellularity, sensitivity improved up to 76.5% (95% CI = 58.8–89.3). Results also suggest the putative role of MALDI-MSI in routine clinical triage, with a three levels diagnostic classification that accounts for an indeterminate gray zone of nodules requiring a strict follow-up.

Ultrashort Peptides and Gold Nanoparticles: Influence of Constrained Amino Acids on Colloidal Stability

Poor colloidal stability of gold nanoparticles (AuNPs) in physiological environments remains one of the major limitations that contribute to their difficult translation from bench to clinic. For this reason, an active research field is the development of molecules able to hamper AuNPs aggregation tendency in physiological environments. In this context, synthetic peptides are gaining an increased interest as an alternative to the use of biomacromolecules and polymers, due to their easiness of synthesis and their profitable pharmacokinetic profile. In this work, we reported on the use of ultrashort peptides containing conformationally constrained amino acids (AAs) for the stabilization of AuNPs. A small library of non-natural self-assembled oligopeptides were synthesized and used to functionalize spherical AuNPs of 20 nm diameter, via the ligand exchange method. The aim was to investigate the role of the constrained AA, the anchor point (at C- or N-terminus) and the peptide length on their potential use as gold binding motif. Ultrashort Aib containing peptides were identified as effective tools for AuNPs colloidal stabilization. Furthermore, peptide coated AuNPs were found to be storable as powders without losing the stabilization properties once re-dispersed in water. Finally, the possibility to exploit the developed systems for binding proteins via molecular recognition was also evaluated using biotin as model.

Lipidomic Typing of Colorectal Cancer Tissue Containing Tumour-Infiltrating Lymphocytes by MALDI Mass Spectrometry Imaging

Predicting the prognosis of colorectal cancer (CRC) patients remains challenging and a characterisation of the tumour immune environment represents one of the most crucial avenues when attempting to do so. For this reason, molecular approaches which are capable of classifying the immune environments associated with tumour infiltrating lymphocytes (TILs) are being readily investigated. In this proof of concept study, we aim to explore the feasibility of using spatial lipidomics by MALDI-MSI to distinguish CRC tissue based upon their TIL content. Formalin-fixed paraffin-embedded tissue from human thymus and tonsil was first analysed by MALDI-MSI to obtain a curated mass list from a pool of single positive T lymphocytes, whose putative identities were annotated using an LC-MS-based lipidomic approach. A CRC tissue microarray (TMA, n = 30) was then investigated to determine whether these cases could be distinguished based upon their TIL content in the tumour and its microenvironment. MALDI-MSI from the pool of mature T lymphocytes resulted in the generation of a curated mass list containing 18 annotated m/z features. Initially, subsets of T lymphocytes were then distinguished based on their state of maturation and differentiation in the human thymus and tonsil tissue. Then, when applied to a CRC TMA containing differing amounts of T lymphocyte infiltration, those cases with a high TIL content were distinguishable from those with a lower TIL content, especially within the tumour microenvironment, with three lipid signals being shown to have the greatest impact on this separation (p < 0.05). On the whole, this preliminary study represents a promising starting point and suggests that a lipidomics MALDI-MSI approach could be a promising tool for subtyping the diverse immune environments in CRC.

Peptide-Based Electrospun Fibers: Current Status and Emerging Developments

Electrospinning is a well-known, straightforward, and versatile technique, widely used for the preparation of fibers by electrifying a polymer solution. However, a high molecular weight is not essential for obtaining uniform electrospun fibers; in fact, the primary criterion to succeed is the presence of sufficient intermolecular interactions, which function similar to chain entanglements. Some small molecules able to self-assemble have been electrospun from solution into fibers and, among them, peptides containing both natural and non-natural amino acids are of particular relevance. Nowadays, the use of peptides for this purpose is at an early stage, but it is gaining more and more interest, and we are now witnessing the transition from basic research towards applications. Considering the novelty in the relevant processing, the aim of this review is to analyze the state of the art from the early 2000s on. Moreover, advantages and drawbacks in using peptides as the main or sole component for generating electrospun nanofibers will be discussed. Characterization techniques that are specifically targeted to the produced peptide fibers are presented.

Peptide grafting strategies before and after electrospinning of nanofibers

Nanofiber films produced by electrospinning currently provide a promising platform for different applications. Although nonfunctionalized nanofiber films from natural or synthetic polymers are extensively used, electrospun materials combined with peptides are gaining more interest. In fact, the selection of specific peptides improves the performance of the material for biological applications and mainly for tissue engineering, mostly by maintaining similar mechanical properties with respect to the simple polymer. The main drawback in using peptides blended with a polymer is the quick release of the peptides. To avoid this problem, covalent linking of the peptide is more beneficial. Here, we reviewed synthetic protocols that enable covalent grafting of peptides to polymers before or after the electrospinning procedures to obtain more robust electrospun materials. Applications and the performance of the new material compared to that of the starting polymer are discussed.

Ex vivo thyroid fine needle aspirations as an alternative for MALDI-MSI proteomic investigation: intra-patient comparison

Fine needle aspiration (FNA) is the reference standard for the diagnosis of thyroid nodules. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has been successfully used to discriminate the proteomic profiles of benign and malignant thyroid FNAs within the scope of providing support to pathologists for the classification of morphologically borderline cases. However, real FNAs provide a limited amount of material due to sample collection restrictions. Ex vivo FNAs could represent a valuable alternative, increasing sample size and the power of statistical conclusions. In this study, we compared the real and ex vivo MALDI-MSI proteomic profiles, extracted from thyrocyte containing regions of interest, of 13 patients in order to verify their similarity. Statistical analysis demonstrated the mass spectra similarity of the proteomic profiles by performing intra-patient comparison, using statistical similarity systems. In conclusion, these results show that post-surgical FNAs represent a possible alternative source of material for MALDI-MSI proteomic investigations in instances where pre-surgical samples are unavailable or the number of cells is scarce.

Diastereoselective Synthesis of Pyrazolines by Metal-Free Rearrangement of Bicyclic Triazolines

The metal-free preparation of diazoalkanes through the ring rearrangement of bicyclic triazolines is reported here. Their use in 1,3-dipolar cycloaddition reactions with electron-withdrawing alkenes was investigated. This synthetic procedure allows differently substituted pyrazolines to be obtained in few steps and with high atom economy.

Non-natural 3-Arylmorpholino-β-amino Acid as a PPII Helix Inducer

A new non-natural β-amino acid, named 3-Ar-β-Morph, was designed and synthesized via a regio- and diastereoselective Pd-catalyzed C(sp3)H-arylation of the corresponding 2S,6S-(6-methoxymorpholin-2-yl)carboxylic acid, readily available from glucose. According to the computational prevision and confirmed by IR and NMR data, the insertion of 3-Ar-β-Morph in a model foldamer represents a way to stabilize a PPII-like helix through the presence of two γ-turns, secondary structure motifs induced by the morpholine ring, and the trans-tertiary amide bond.

Antigen Retrieval and Its Effect on the MALDI-MSI of Lipids in Formalin-Fixed Paraffin-Embedded Tissue

Formalin-fixed paraffin-embedded (FFPE) tissue represents the primary source of clinical tissue and is routinely used in MALDI-MSI studies. However, it is not particularly suitable for lipidomics imaging given that many species are depleted during tissue processing. Irrespective, a number of solvent-resistant lipids remain, but their extraction may be hindered by the cross-link between proteins. Therefore, an antigen retrieval step could enable the extraction of a greater number of lipids and may provide information that is complementary to that which can be obtained from other biomolecules, such as proteins. In this short communication, we aim to address the effect of performing antigen retrieval prior to MALDI-MSI of lipids in FFPE tissue. As a result, an increased number of lipid signals could be detected and may have derived from lipid species that are known to be implicated in the lipid-protein cross-linking that is formed as a result of formalin fixation. Human renal cancer tissue was used as a proof of concept to determine whether using these detected lipid signals were also able to highlight the histopathological regions that were present. These preliminary findings may highlight the potential to enhance the clinical relevance of the lipidomic information obtained from FFPE tissue.

Molecular trait of follicular-patterned thyroid neoplasms defined by MALDI-imaging

In the field of thyroid neoplasms, the most interesting recent change regards the introduction of a new terminology for follicular-patterned thyroid tumors, named Noninvasive Thyroid Neoplasm with Papillary-like Nuclear Features (NIFTP). This pre-malignant tumor is considered to be the putative precursor of invasive carcinoma. However, given that several issues are still unresolved, the application of ancillary tools, based on omics-techniques, may improve the clinical management of these challenging cases. The present paper highlights the proteomic profiles of a series of NIFTPs submitted to Fine Needle Aspirations (FNAs) and analysed by MALDI-imaging in order to confirm the heterogeneous phenotype of nodules included in the present NIFTP terminology and to underline the necessity of more accurate biomarkers that can be used for their characterization. Ethical and economic implications in terms of healthcare costs, operative risks, morbidity, as well as the potential need for lifelong hormone replacement therapy, seem to be significant reasons to approach the characterization of NIFTPs using alternative tools such as MALDI-MSI.

Analysis of Hashimoto's thyroiditis on fine needle aspiration samples by MALDI-Imaging

Matrix-Assisted Laser Desorption/Ionization (MALDI)-Mass Spectrometry imaging (MSI) has been applied in various diseases aimed to biomarkers discovery. In this study diagnosis and prognosis of Hashimoto Thyroiditis (HT) in cytopathology by MALDI-MSI has been investigated. Specimens from a routine series of subjects who underwent UltraSound-guided thyroid Fine Needle Aspirations (FNAs) were used. The molecular classifier trained in a previous study was modified to include HT as a separate entity in the group of benign lesions, in the diagnostic proteomic triage of thyroid nodules. The statistical analysis confirmed the existence of signals that HT shares with hyperplastic lesions and others that are specific and characterize this subgroup. Statistically relevant HT-related peaks were included in the model. Then, the discriminatory capability of the classifier was tested in a second validation phase, showing a good agreement with cytological diagnoses. The possibility to overlap the molecular signatures of both the lymphocytes and epithelial cells components (ROIs or pixel-by-pixel analysis) confirmed the composite proteomic background of HT. These results open the way to their possible translation as alternative serum biomarkers of this autoimmune condition.

P0354MATRIX ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY IN PROTEIN ALTERATIONS ASSOCIATED WITH THE PROGRESSION OF IGA NEPHROPATHY DISCOVERY

Background and Aims

IgA nephropathy (IgAN) is one of the most diffuse glomerulonephrites worldwide, but there are still many issues regarding its prognosis and pathogenesis understanding. Although the diagnosis is established by renal biopsy examination, there are still remaining pitfalls in primary origin discrimination, and therefore for prognosis and outcome for the patient.

Method

In this pilot study we performed matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) with a high spatial resolution (raster sampling of 20 μm) on formalin fixed paraffin embedded renal biopsies obtained from patients with IgAN (n=11) and other mesangioproliferative glomerulonephrites (MesPGN, n=6) attempting to enlighten proteomic alterations that may be associated with the progression of IgAN. The patients in both disease groups were separated according to their CKD stage (CKDI, CKDII, CKDIII and more). After MALDI-MSI analysis, all biopsies were stained with hematoxylin and eosin, scanned and overlaid with molecular image in order to verify the signals’ spatial distribution.

Results

Using MALDI-MSI we detected clear differences in the proteomic profiles of IgAN and other MesPGN tissues. Fourteen signals (AUC ≥ 0.8) were observed to have an altered intensity among the different CKD stages within the IgAN group. In particular, large increases in the intensity of these signals could be observed at CKD stages II and above. Putatively identified, these signals primarily corresponded to proteins involved in inflammatory and healing pathways and their increased intensity was localised within regions of tissue with large amounts of inflammatory cells or sclerosis (Figure 1), verified by immunohistochemical staining (Figure 2).

Conclusion

The capability of MALDI-MSI to provide highly spatially resolved proteomics analysis of complex renal tissue demonstrates it a useful additional diagnostic and prognostic tool and a promising approach in the search for prognostic or predictive markers in glomerular diseases.

Self-assembled hydrophobic Ala-Aib peptide encapsulating curcumin: a convenient system for water insoluble drugs

The exploitation of self-assembled systems to improve the solubility of drugs is getting more and more attention. Among the different types of self-assembled biomaterials, peptides and in particular peptides containing non-coded amino acids (NCAPs) are promising because their use opens the door to more stable materials inducing increased stability to proteolysis. New classes of NCAP, Ac-Ala-X-Ala-Aib-AlaCONH2 (X = alpha-aminoisobutyric acid (Aib) or X = cyclopentane amino acid (Ac5c)) have been prepared and the correlation between the different secondary peptide structure and solvent (i.e. CD3CN, CD3OH, H2O/D2O) verified by NMR. Furthermore, the formation of a nanocolloidal system in water was deeply studied by DLS and the morphology of the obtained spherical aggregates with nanometric dimensions was assessed by TEM. Aib containing pentapeptide was selected for greater ease of synthesis. Its ability to encapsulate curcumin, as a model insoluble drug molecule, was investigated using fluorescence emission and confocal microscopy analyses. Two different approaches were used to study the interaction between curcumin and peptide aggregates. In the first approach peptide aggregates were formed in the presence of curcumin, while in the second approach curcumin was added to the already formed peptide aggregates. We succeeded in our challenge by using the second approach and 53.8% of added curcumin had been encapsulated.

In-Depth Mapping of the Urinary N-Glycoproteome: Distinct Signatures of ccRCC-related Progression

Protein N-glycosylation is one of the most important post-translational modifications and is involved in many biological processes, with aberrant changes in protein N-glycosylation patterns being closely associated with several diseases, including the progression and spreading of tumours. In light of this, identifying these aberrant protein glycoforms in tumours could be useful for understanding the molecular mechanism of this multifactorial disease, developing specific biomarkers and finding novel therapeutic targets. We investigated the urinary N-glycoproteome of clear cell renal cell carcinoma (ccRCC) patients at different stages (n = 15 at pT1 and n = 15 at pT3), and of non-ccRCC subjects (n = 15), using an N-glyco-FASP-based method. Using label-free nLC-ESI MS/MS, we identified and quantified several N-glycoproteins with altered expression and abnormal changes affecting the occupancy of the glycosylation site in the urine of RCC patients compared to control. In particular, nine of them had a specific trend that was directly related to the stage progression: CD97, COCH and P3IP1 were up-expressed whilst APOB, FINC, CERU, CFAH, HPT and PLTP were down-expressed in ccRCC patients. Overall, these results expand our knowledge related to the role of this post-translational modification in ccRCC and translation of this information into pre-clinical studies could have a significant impact on the discovery of novel biomarkers and therapeutic target in kidney cancer.

Tuning PFKFB3 Bisphosphatase Activity Through Allosteric Interference

The human inducible phospho-fructokinase bisphosphatase isoform 3, PFKFB3, is a crucial regulatory node in the cellular metabolism. The enzyme is an important modulator regulating the intracellular fructose-2,6-bisphosphate level. PFKFB3 is a bifunctional enzyme with an exceptionally high kinase to phosphatase ratio around 740:1. Its kinase activity can be directly inhibited by small molecules acting directly on the kinase active site. On the other hand, here we propose an innovative and indirect strategy for the modulation of PFKFB3 activity, achieved through allosteric bisphosphatase activation. A library of small peptides targeting an allosteric site was discovered and synthesized. The binding affinity was evaluated by microscale thermophoresis (MST). Furthermore, a LC-MS/MS analytical method for assessing the bisphosphatase activity of PFKFB3 was developed. The new method was applied for measuring the activation on bisphosphatase activity with the PFKFB3-binding peptides. The molecular mechanical connection between the newly discovered allosteric site to the bisphosphatase activity was also investigated using both experimental and computational methods.

MALDI-MSI as a Complementary Diagnostic Tool in Cytopathology: A Pilot Study for the Characterization of Thyroid Nodules

The present study applies for the first time as Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry Imaging (MSI) on real thyroid Fine Needle Aspirations (FNAs) to test its possible complementary role in routine cytology in the diagnosis of thyroid nodules. The primary aim is to evaluate the potential employment of MALDI-MSI in cytopathology, using challenging samples such as needle washes. Firstly, we designed a statistical model based on the analysis of Regions of Interest (ROIs), according to the morphological triage performed by the pathologist. Successively, the capability of the model to predict the classification of the FNAs was validated in a different group of patients on ROI and pixel-by-pixel approach. Results are very promising and highlight the possibility to introduce MALDI-MSI as a complementary tool for the diagnostic characterization of thyroid nodules.

Fluoro-Aryl Substituted α,β2,3-Peptides in the Development of Foldameric Antiparallel β-Sheets: A Conformational Study

α,β^2,3-Disteroisomeric foldamers of general formula Boc(S-Ala-β-2R,3R-Fpg)_nOMe or Boc(S-Ala-β-2S,3S-Fpg)_nOMe were prepared from both enantiomers of syn H-2-(2-F-Phe)-h-PheGly-OH (named β-Fpg) and S-alanine. Our peptides show two appealing features for biomedical applications: the presence of fluorine, attractive for non-covalent interactions, and aryl groups, crucial for π-stacking. A conformational study was performed, using IR, NMR and computational studies of diastereoisomeric tetra- and hexapeptides containing the β^2,3-amino acid in the R,R- and S,S-stereochemistry, respectively. We found that the stability of peptide conformation is dependent on the stereochemistry of the β-amino acid. Combining S-Ala with β-2R,3R-Fpg, a stable extended β-strand conformation was obtained. Furthermore, β-2R,3R-Fpg containing hexapeptide self-assembles to form antiparallel β-sheet structure stabilized by intermolecular H-bonds and π,π-interactions. These features make peptides containing the β^2,3-fluoro amino acid very appealing for the development of bioactive proteolytically stable foldameric β-sheets as modulators of protein-protein interaction (PPI).

From glucose to enantiopure morpholino β-amino acid: a new tool for stabilizing γ-turns in peptides

“Environmentally sustainable” synthesis of a new enantiopure morpholino β-amino acid from glucose: a new tool for exotic peptide architectures.

Electrospinning of pyrazole-isothiazole derivatives: nanofibers from small molecules

We investigate the electrospinning of small molecules, specifically designed peptide derivatives of the pyrazole-isothiazole scaffold. Such non-natural peptides enhance the spectrum of fundamental materials used for electrospinning. Unlike standard electrospun materials, our peptides are not polymeric, but able to aggregate in solution and especially during processing. They contain donor/acceptor groups that can form hydrogen bonds, and groups that are able to generate π-stacking interactions, which are known as important requirements for assembly processes. The pyrazole-isothiazole derivatives were synthesized by means of a 1,3-dipolar cycloaddition reaction, which is completely regioselective, affording only one isomer. We demonstrate that our compounds can be electrospun from fluoroalcohol solution into solid, quasi-endless micro- and nanofibers. The electrospinnability varies substantially, depending on the amino acids linked to the scaffold. Some compounds provide only short fibers, while Fmoc-glycyl-(N-benzyl)-pyrazole-isothiazole-tert-butyl carboxylate-1,1-dioxide forms continuous, homogenous, and bead-free fibers (droplet-like beads are a common problem in electrospinning). We analyzed the compounds and the fibers with various spectroscopic techniques (MS, IR and Raman). Electrospinning does not change chemical composition and configuration, suggesting the monomeric form of the compounds even in the fibers. Interestingly, we found that the stereochemistry of the scaffold can affect the ability of the peptide to be electrospun.

Pyrazole-isothiazole monomers are electrospun from solution into solid, quasi-endless micro- and nanofibers.

Identification of the first enantiopure Rac1-Tiam1 protein-protein interaction inhibitor and its optimized synthesis via phosphine free remote group directed hydroarylation

A phospine free hydroarylation reaction applied to norbornene derivatives is described for the first time and was exploited for the regioselective gram scale synthesis of AR-148, a known Rac1-Tiam1 PPI inhibitor. Umpolung conversion of the nitro group into free amine allowed the regiocontrol of the key arylation step via a long range effect. The effect of AR-148 in comparison with its enantiomers on Rac1 activation of has been evaluated and (-)AR-148 has been identified as the first enantiomerically pure inhibitor of Rac1-Tiam1 PPI.

Body Mass Index Predicts Progression of Mild Cognitive Impairment to Dementia

AIMS

To examine the relationship between body mass index (BMI) and progression to dementia and Alzheimer's disease (AD) in mild cognitive impairment (MCI).

MATERIALS AND METHODS

Two hundred and twenty-eight MCI subjects (mean age 74.04 ± 6.94 years; 57% female) from a memory clinic were followed for 2.40 ± 1.58 years. Baseline height and weight were used to calculate the BMI. The main outcome was progression to dementia (DSM-IV criteria) and AD (NINCDS-ADRDA criteria). Cox proportional hazard models were used to assess the longitudinal association of BMI with dementia and AD, adjusting for a comprehensive set of covariates, including vascular risk factors/diseases and neuroimaging profiles.

RESULTS

Out of 228 subjects with MCI, 117 (51.3%) progressed to dementia. Eighty-nine (76%) of the incident dementia cases had AD. In both unadjusted and multi-adjusted models, a higher BMI was associated with a reduced risk of dementia (multi-adjusted HR 0.9; 95% CI 0.8-0.9) and AD (multi-adjusted HR 0.9; 95% CI 0.8-0.9). Being underweight increased the risk of all types of dementia (multi-adjusted HR 2.5; 95% CI 1.2-5.1) but was not specifically associated with AD (multi-adjusted HR 2.2; 95% CI 0.9-5.3).

CONCLUSIONS

BMI predicted progression of MCI to dementia and AD. In particular, a higher BMI was associated with a lower risk of dementia and AD, and underweight was associated with a higher risk of dementia. BMI assessment may improve the prognostic accuracy of MCI in clinical practice.

Tandem Tetrahydroisoquinoline-4-carboxylic Acid/β-Alanine as a New Construct Able To Induce a Flexible Turn

Tetrahydroisoquinoline-4-carboxylic acid, a constrained β² -amino acid named β-TIC, was synthesised for the first time in enantiopure form. The biocatalytic route applied herein represents one of the few successful examples of enzymatic resolution of β² -amino acids. Model tetrapeptides, namely, Fmoc-l-Ala-β-TIC-β-Ala-l-Val-OBn (Fmoc=fluorenylmethyloxycarbonyl, Bn=benzyl), containing both isomers of β-TIC, were prepared. Both computational and NMR spectroscopy studies were performed. A reverse-turn conformation was observed in the case of (R)-β-TIC enantiomer that was obtained in 99 % enantiomeric excess by enzymatic resolution. The β-TIC/β-Ala construct represents the first example of a flexible turn mimetic containing a cyclic and an acyclic β-amino acid. Furthermore, the presence of an aromatic ring of β-TIC could facilitate non-covalent interactions to increase the potential of this scaffold for the preparation of protein-protein interaction modulators.

In situ MoS2 Decoration of Laser-Induced Graphene as Flexible Supercapacitor Electrodes

Herein, we are reporting a rapid one-pot synthesis of MoS2-decorated laser-induced graphene (MoS2-LIG) by direct writing of polyimide foils. By covering the polymer surface with a layer of MoS2 dispersion before processing, it is possible to obtain an in situ decoration of a porous graphene network during laser writing. The resulting material is a three-dimensional arrangement of agglomerated and wrinkled graphene flakes decorated by MoS2 nanosheets with good electrical properties and high surface area, suitable to be employed as electrodes for supercapacitors, enabling both electric double-layer and pseudo-capacitance behaviors. A deep investigation of the material properties has been performed to understand the chemical and physical characteristics of the hybrid MoS2-graphene-like material. Symmetric supercapacitors have been assembled in planar configuration exploiting the polymeric electrolyte; the resulting performances of the here-proposed material allow the prediction of the enormous potentialities of these flexible energy-storage devices for industrial-scale production.

Weight Loss Predicts Progression of Mild Cognitive Impairment to Alzheimer's Disease

Background

Weight loss is common in people with Alzheimer’s disease (AD) and it could be a marker of impending AD in Mild Cognitive Impairment (MCI) and improve prognostic accuracy, if accelerated progression to AD would be shown.

Aims

To assess weight loss as a predictor of dementia and AD in MCI.

Methods

One hundred twenty-five subjects with MCI (age 73.8 ± 7.1 years) were followed for an average of 4 years. Two weight measurements were carried out at a minimum time interval of one year. Dementia was defined according to DSM-IV criteria and AD according to NINCDS-ADRDA criteria. Weight loss was defined as a ≥4% decrease in baseline weight.

Results

Fifty-three (42.4%) MCI progressed to dementia, which was of the AD-type in half of the cases. Weight loss was associated with a 3.4-fold increased risk of dementia (95% CI = 1.5–6.9) and a 3.2-fold increased risk of AD (95% CI = 1.4–8.3). In terms of years lived without disease, weight loss was associated to a 2.3 and 2.5 years earlier onset of dementia and AD.

Conclusions

Accelerated progression towards dementia and AD is expected when weight loss is observed in MCI patients. Weight should be closely monitored in elderly with mild cognitive impairment.

Aqueous self-assembly of short hydrophobic peptides containing norbornene amino acid into supramolecular structures with spherical shape

The preparation and self-assembly of short hydrophobic peptides containing the non-coded norbornene amino acid is reported. The formation of a supramolecular assembly in water was assessed by TEM and DLS.

Cognitive impairment is a negative short-term and long-term prognostic factor in elderly patients with hip fracture

BACKGROUND

Subjects with severe cognitive impairment (CI) have a high-risk of hip fractures with increased rate of adverse postoperative functional outcomes and mortality.

AIM

To evaluate the impact of different degrees of CI on functional recovery and mortality after hip fracture.

DESIGN

Prospective observational study.

SETTING

Two orthopedic surgery units.

POPULATION

Two hundred twenty-eight consecutive patients after a hip surgery.

METHODS

Patients were assessed at baseline through the Short Portable Mental Status Questionnaire (SPMSQ), an instrument that allows to categorize subjects as follows: cognitively intact (SPMSQ≥8) or with mild (SPMSQ=6-7), moderate (SPMSQ=3-5) and severe CI (SPMSQ<3). Barthel Index (BI) was used to assess functional disability. All patients underwent rehabilitation from the day after surgery to discharge (mean length of stay =10.2±3.4). Outcome measures were: (1) overall mortality up to 12 months after surgery; (2) motor ability achieved at discharge from the orthopedic ward (sitting, standing, walking); (3) BI and SPMSQ at 1, 3, 6 and 12 months postoperatively.

RESULTS

All degrees of severity of CI were inversely correlated to the ability to walk at hospital discharge. At one year from surgery, the majority of patients with CI were functionally severely dependent, whereas about half of the cognitively intact ones gained a functional independence status. CI and the level of premorbid disability influenced the risk of death.

CONCLUSION

CI for all degrees of severity is a negative prognostic factor in elderly patients with hip fracture.

CLINICAL REHABILITATION IMPACT

We suggest evaluating the cognitive status of patients with hip fracture as it affects both the short and long-term functional recovery at any degree of severity.

MediaChrom: Discovering a Class of Pyrimidoindolone-Based Polarity-Sensitive Dyes

A small library of six polarity-sensitive fluorescent dyes, nicknamed MediaChrom, was prepared. This class of dyes is characterized by a pyrimidoindolone core fitted out with a conjugated push-pull system and a carboxy linker for a conceivable coupling with biomolecules. The optimized eight-step synthetic strategy involves a highly chemo- and regioselective gold-catalyzed cycloisomerization reaction. The photophysical properties of MediaChrom dyes have been evaluated in-depth. In particular, the MediaChrom bearing a diethylamino as an electron-donating group and a trifluoromethyl as an electron-withdrawing group displays the most interesting and advantageous spectroscopic features (e.g., absorption and emission in the visible range and a good quantum yield). Promising results in terms of sensitivity have been obtained in vitro on this dye as a membrane/lipophilic probe and as a peptide fluorescent label.

General cognition predicts post-stroke recovery defined through minimal clinically important difference (MCID): a cohort study in an Italian rehabilitation clinic

BACKGROUND

In the field of rehabilitation it is crucial to define if changes in functional scores correspond to relevant clinical improvements.

AIM

To assess whether cognition affects motor recovery in post-stroke patients using a clinical meaningful criterion: the minimal clinically important difference (MCID).

DESIGN

Retrospective cohort study.

SETTING

Inpatient rehabilitation clinic

POPULATION

Two hundred nine first-ever stroke patients undergoing a post-acute inpatient rehabilitation.

METHODS

Cognitive status was assessed with the cognitive FIM and the Mini-Mental State Examination (MMSE). The response to the rehabilitation was defined as the achievement of the MCID between admission and discharge in the motor FIM (responder) and both in the motor and in the cognitive FIM (best-responder).

RESULTS

Subjects with a baseline higher MMSE>24.9 had a near four-fold higher probability of being responder (OR 3.91; 95% CI 1.72-8.89) and a two-fold higher probability of being best-responder (OR 2.69; 95% CI 1.24-5.84) on motor FIM as compared to those with a MMSE≤24.9. A duration of the rehabilitation of 55-61 days implies a three-fold higher probability (OR 3.17; 95% CI 1.15-8.72) to be responder as compared to shorter period of treatment; a treatment >61 days does not involve a greater probability of response.

CONCLUSIONS

This is the first study that examined post-stroke motor recovery mainly in terms of clinical relevance (MCID). Subjects with a higher cognitive level are more likely to achieve a clinically meaningful recovery.

CLINICAL REHABILITATION IMPACT

MCID can be applied extensively to post-stroke patients undergoing to an inpatient rehabilitation in order to have a clinically useful instrument that assess the recovery.

Transmembrane protein 106B gene (TMEM106B) variability and influence on progranulin plasma levels in patients with Alzheimer's disease

We carried out an association study of transmembrane protein 106B gene (TMEM106B) rs1020004 A/G, rs6966915C/T, and rs1990622 A/G in a population of 656 patients with Alzheimer's disease (AD) and 619 controls, and tested whether the rs1990622 influences plasma progranulin levels. No differences in allele and genotype distribution were observed between cases and controls, even stratifying according to APOE status (p > 0.05). No differences in progranulin plasma levels were found between carriers of the rs1990622 and non-carriers. TMEM106b variability does not influence AD risk or plasma levels. Replication, preferably in a population with pathological confirmation, is required to confirm these results.

Estimating the inheritance of frontotemporal lobar degeneration in the Italian population

Frontotemporal dementia (FTD) has a strong genetic basis, with familial forms occurring in 30-50% of cases. Causative genes have been identified, with an autosomal dominant pattern of inheritance. Notwithstanding, in a number of cases with positive family history no pathogenetic mutation has been reported, and the role of genetics in sporadic cases is still unclear. In the present study, we aim to estimate the genetic contribution to FTD using concordance among parent-offspring pairs. Heritability of early-onset (EO, <65 years) and late-onset (LO, ≥65 years) FTD was estimated by examining the concordance between parents and offspring. Probands with at least one parent whose dementia status was known were recruited from 15 Italian centers, and the presence or absence of dementia was considered in siblings. Different prevalence estimates, as available by literature data, were tested. A total of 260 probands and 1619 family members were considered in this study. We found that parent-offspring concordance in FTD was 6.25%, resulting in hereditability of 98.5% (95% confidence interval (CI): 85.0%-100.0%). Equal heritability for both sexes regardless of parental gender was reported. EO-FTD showed hereditability of 86.3% (95% CI: 77.0%-95.0%) and LO-FTD of 75.7% (95% CI: 65.0%-86.0%). Estimating the contribution of genetics in FTD may help in driving future genetic studies to identify new pathogenetic determinants. We suggest that in most of the cases FTD is a genetic-based disease, even in the elderly. Different inheritance modality might be considered in future work, beyond autosomal dominant disease.

Model peptides containing the 3-sulfanyl-norbornene amino acid, a conformationally constrained cysteine analogue effective inducer of 310-helix secondary structures

Two model peptides containing the 3-benzylsulfanylnorbornene amino acid (NRB) was prepared. Theoretical calculations, spectroscopic and X-ray analyses confirmed that both NRB enantiomers possess a strong right-handed helicogenic effect.

Expression of the transcription factor Sp1 and its regulatory hsa-miR-29b in peripheral blood mononuclear cells from patients with Alzheimer's disease

Altered gene expression occurs in central nervous system disorders, including Alzheimer's disease (AD). Transcription factor Sp1 (specificity protein 1) can regulate the expression of several AD-related proteins, including amyloid-β protein precursor and tau. Sp1 is regulated by oxidative stress, and Sp1 mRNA was found to be upregulated in AD cortex and hippocampus. The distribution of three single nucleotide polymorphisms (SNPs), including rs7300593, rs17695156, and rs12821290, covering 100% Sp1 genetic variability, has been determined in a population of 393 AD patients as compared with 412 controls. In addition, expression analysis of Sp1 and its regulatory microRNAs (hsa-miR-29b and hsa-miR-375) has been performed in peripheral blood mononuclear cells (PBMCs), together with Sp1 protein analysis. No differences in all three SNP distributions were observed in AD patients as compared with controls. Stratifying according to gender, a significantly decreased frequency of Sp1 rs17695156 T allele was observed in male patients versus male controls. Significantly increased Sp1 relative expression levels were observed in PBMCs from AD patients as compared with controls. Western blot analysis paralleled mRNA increase in AD patients versus controls and correlated positively with Sp1 mRNA levels. Significantly decreased relative expression levels of hsa-miR-29b, but not of hsa-miR-375, were observed in AD patients versus controls and correlated negatively with Sp1 mRNA levels. According to these results, Sp1 and its regulatory hsa-miR-29b are deregulated in AD patients, possibly leading to aberrant production of downstream target genes involved in the pathogenesis. Moreover, Sp1 rs176951056 T allele is likely a protective factor in the male population.