Frailty and rehabilitation outcome in older patients with cardiorespiratory disease: preliminary multidimensional data.

Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are two clinical conditions often associated with cognitive dysfunctions, psychological distress, poor quality of life (QoL), and functional worsening. In addition, since patients suffering from these conditions are often older adults, frailty syndrome represents a further and important issue to be investigated. The present preliminary study aimed to perform a multidimensional assessment of CHF and/or COPD older patients (age ≥65) undergoing cardiac or pulmonary rehabilitation. The characteristics of the included patients (30 CHF and 30 COPD) resulted almost similar, except for the COPD patients' longer duration of illness and better performances in Addenbrooke's cognitive examination III subtests and short physical performance battery (SPPB). No significant differences were found in the frailty evaluation, but a consistent number of patients resulted to be frail (CHF=36.7% vs COPD=26.6%). After the rehabilitation program, a significant improvement was found in the whole sample concerning the executive functions (14.34±2.49 vs 15.62±2.22, p=0.001), quality of life (58.77±18.87 vs 65.82±18.45, p=0.003), depressive and anxious symptoms (6.27±4.21 vs 3.77±3.39, p=0.001 and 5.17±3.40 vs 3.38±3.21, p=0.001), frailty status [4.00 (3.00,5.00) vs 3.00 (3.00,5.00) p=0.035] and functional exercise abilities [SPPB, 7.40±3.10 vs 9.51±3.67, p=0.0002; timed up and go test, 14.62±4.90 vs 11.97±4.51, p<0.0001; 6-minute walking test, 353.85±127.62 vs 392.59±123.14, p=0.0002]. Preliminary results showed a substantial homogeneity of CHF and COPD older patients' cognitive, psychosocial, frailty, and functional characteristics. Nevertheless, the specific rehabilitation intervention appears promising in both clinical populations. This trial has been registered with the ClinicalTrials.gov, NCT05230927 registration number (clinicaltrials.gov/ct2/show/NCT05230927).

Metal cation responsive anionic microgels: behaviour towards biologically relevant divalent and trivalent ions.

Anionic poly(vinylcaprolactam-co-itaconicacid-co-dimethylitaconate) microgels were synthesized via dispersion polymerization and their responsiveness towards cations, namely Mg2+, Sr2+, Cu2+ and Fe3+, was investigated. The itaconic moieties chelate the metal ions which act as a crosslinker and decrease the electrostatic repulsion within the network, leading to a decrease in the gel size. The responsiveness towards the metal ion concentration has been studied via dynamic light scattering (DLS) and the number of ions bonded within the network has been quantified with ion chromatography. Through the protonation of the carboxylate groups in the gel network, their interaction with the cations is significantly lowered, and the metals are consequently released back in solution. The number of ions released was assessed also via ion chromatography for all four ions, whilst Mg2+ was also used as a model ion to display the reversibility of the system. The microgels can bond and release divalent cations over multiple cycles without undergoing any loss of functionality. Moreover, these gels also selectively entrap Fe3+ with respect to the remaining divalent cations, opening the possibility of using the proposed gels in the digestive tract as biocompatible chelating agents to fight iron overaccumulation.

Silica-Coated TiN Particles for Killing Cancer Cells.

Photothermal therapy (PTT) using plasmonic nanoparticles for cancer treatment is on the verge of clinical application. Titanium nitride (TiN) nanoparticles offer a promising alternative to commonly used gold-based systems at a fraction of the costs. Little is known, however, about the relationship between TiN particle characteristics and their optical properties in colloidal systems. Here, TiN nanoparticles with closely controlled characteristics are prepared by nitridation of TiO2, and their use as PTT agents is explored. Emphasis is placed on the particle surface and core oxygen content, which dominate the TiN optical properties. Colloidal suspensions were studied under UV-vis and near-infrared (NIR) laser irradiation and correlated to particle characteristics. High nitridation temperatures and long residence times lead to increased NIR light absorption. Too high nitridation temperatures, however, lead to particle aggregation that deteriorated their optical properties. This was overcome with SiO2 coating of TiO2 nanoparticles prior to nitridation: the resulting SiO2-coated TiN particles exhibited increased plasmonic performance compared to bare TiN, which is attributed to reduced plasmonic coupling effects. The optimized SiO2-coated TiN had a photothermal efficiency of 58.5% and mass extinction coefficient of 31.6 L g-1 cm-1, outperforming commercial gold nanoshells that are used in clinical trials. The potential of SiO2-coated TiN for photothermal therapy was demonstrated by controllably killing HeLa cells in vitro.

Synthesis and screening of N-acyl thiolated chitosans for antibacterial applications.

Low-molecular weight chitosan-thioglycolic acid has shown significant antibacterial properties against different microorganisms. In order to explore the potential and structure-activity relationships of newly synthesized alkyl thiomers, chitosan has been functionalized with a series of thio-acids with increasing alkyl chain length. All thiomers were characterized with special emphasis on the determination of their degree of deacetylation and substitution, as well as on their molecular weight and amount of thiol groups. The pre-screened chitosan-thiomers were further investigated with plate counting on Pseudomonas aeruginosa, Streptococcus sobrinus and Streptococcus mutans. Furthermore, LIVE/DEAD assays supported the efficiency of chitosan-thiomers against the above microorganisms. All fully characterized chitosan-thiomers showed comparable or enhanced antimicrobial activity compared to pristine chitosan. Our comprehensive approach paves the way to detailed explorations of much sought-after structure activity relationships in the complex chitosan parameter room, starting from correlations between alkyl chain length and antimicrobial activity.

A complex equilibrium among partially unfolded conformations in monomeric transthyretin.

Aggregation of transthyretin (TTR) is known to be linked to the development of systemic and localized amyloidoses. It also appears that TTR exerts a protective role against aggregation of the Aß peptide, a process linked to Alzheimer's disease. In vitro, both processes correlate with the ability of TTR to populate a monomeric state, yet a complete description of the possible conformational states populated by monomeric TTR in vitro at physiological pH is missing. Using an array of biophysical methods and kinetic tests, we show that once monomers of transthyretin are released from the tetramer, equilibrium is established between a set of conformational states possessing different degrees of disorder. A molten globular state appears in equilibrium with the fully folded monomer, whereas an off-pathway species accumulates transiently during refolding of TTR. These two conformational ensembles are distinct in terms of structure, kinetics, and their pathways of formation. Further subpopulations of the protein fold differently because of the occurrence of proline isomerism. The identification of conformational states unrevealed in previous studies opens the way for further characterization of the amyloidogenicity of TTR and its protective role in Alzheimer's disease.

TDP-43 inclusion bodies formed in bacteria are structurally amorphous, non-amyloid and inherently toxic to neuroblastoma cells.

Accumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs) and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein.

Transthyretin suppresses the toxicity of oligomers formed by misfolded proteins in vitro.

Although human transthyretin (TTR) is associated with systemic amyloidoses, an anti-amyloidogenic effect that prevents Aß fibril formation in vitro and in animal models has been observed. Here we studied the ability of three different types of TTR, namely human tetramers (hTTR), mouse tetramers (muTTR) and an engineered monomer of the human protein (M-TTR), to suppress the toxicity of oligomers formed by two different amyloidogenic peptides/proteins (HypF-N and Aß42). muTTR is the most stable homotetramer, hTTR can dissociate into partially unfolded monomers, whereas M-TTR maintains a monomeric state. Preformed toxic HypF-N and Aß42 oligomers were incubated in the presence of each TTR then added to cell culture media. hTTR, and to a greater extent M-TTR, were found to protect human neuroblastoma cells and rat primary neurons against oligomer-induced toxicity, whereas muTTR had no protective effect. The thioflavin T assay and site-directed labeling experiments using pyrene ruled out disaggregation and structural reorganization within the discrete oligomers following incubation with TTRs, while confocal microscopy, SDS-PAGE, and intrinsic fluorescence measurements indicated tight binding between oligomers and hTTR, particularly M-TTR. Moreover, atomic force microscopy (AFM), light scattering and turbidimetry analyses indicated that larger assemblies of oligomers are formed in the presence of M-TTR and, to a lesser extent, with hTTR. Overall, the data suggest a generic capacity of TTR to efficiently neutralize the toxicity of oligomers formed by misfolded proteins and reveal that such neutralization occurs through a mechanism of TTR-mediated assembly of protein oligomers into larger species, with an efficiency that correlates inversely with TTR tetramer stability.

Extracellular chaperones prevent Aß42-induced toxicity in rat brains.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by cognitive decline, formation of the extracellular amyloid ß (Aß42) plaques, neuronal and synapse loss, and activated microglia and astrocytes. Extracellular chaperones, which are known to inhibit amyloid fibril formation and promote clearance of misfolded aggregates, have recently been shown to reduce efficiently the toxicity of HypF-N misfolded oligomers to immortalised cell lines, by binding and clustering them into large species. However, the role of extracellular chaperones on Aß oligomer toxicity remains unclear, with reports often appearing contradictory. In this study we microinjected into the hippocampus of rat brains Aß42 oligomers pre-incubated for 1h with two extracellular chaperones, namely clusterin and α2-macroglobulin. The chaperones were found to prevent Aß42-induced learning and memory impairments, as assessed by the Morris Water Maze test, and reduce Aß42-induced glia inflammation and neuronal degeneration in rat brains, as probed by fluorescent immunohistochemical analyses. Moreover, the chaperones were able to prevent Aß42 colocalisation with PSD-95 at post-synaptic terminals of rat primary neurons, suppressing oligomer cytotoxicity. All such effects were not effective by adding pre-formed oligomers and chaperones without preincubation. Molecular chaperones have therefore the potential to prevent the early symptoms of AD, not just by inhibiting Aß42 aggregation, as previously demonstrated, but also by suppressing the toxicity of Aß42 oligomers after they are formed. These findings elect them as novel neuroprotectors against amyloid-induced injury and excellent candidates for the design of therapeutic strategies against AD.

Protective properties of novel S-acyl-glutathione thioesters against ultraviolet-induced oxidative stress.

UV-induced toxicity is characterized by marked oxidative stress, accompanied by the depletion of key cellular antioxidants, particularly glutathione (GSH). Replenishing cellular GSH may represent a means of counteracting UV-induced toxicity: however, treatment with free GSH is not therapeutically effective due to its unfavorable pharmacokinetic properties. In this study, we show that S-acyl-glutathione (acyl-SG) derivatives, which consist of an acyl chain (of variable length and saturation) linked via a thioester bond to GSH, increase intracellular levels of reduced GSH in primary skin fibroblasts, adenocarcinoma HeLa and neuroblastoma SH-SY5Y cells. Consistent with this, acyl-SG derivatives protect against UV-induced reactive oxygen species (ROS) production and UV-B/C-mediated lipid peroxidation and caspase-3 activation in the analyzed cell lines, with unsaturated thioesters displaying a significantly greater protective effect. Taken together, our findings suggest that acyl-SG thioesters may be therapeutically effective in the treatment of UV-related skin disorders and oxidative stress-mediated conditions in general.

Genetic variants in miR-146a, miR-149, miR-196a2, miR-499 and their influence on relative expression in lung cancers.

BACKGROUND: The presence of sequence variants in miRNA genes may influence their processing, expression and binding to target mRNAs. Since single miRNA can have a large number of potential mRNA targets, even minor variations in its expression can have influences on hundreds of putative mRNAs. METHODS: Here, we evaluated 101 paired samples (cancer and normal tissues) from non-small cell lung carcinoma (NSCLC) patients to study the genotype distribution of single nucleotide polymorphisms (SNPs) in miR-146a (rs2910164 C-G), miR-149 (rs2292832 C-T), miR-196a2 (rs11614913 C-T) and miR-499 (rs3746444 G-A) and their influence on the expression of respective miRNAs. RESULTS: Relative expression of miR-146a, miR-149 and miR-499 were comparable in NSCLC and in paired control tissues. On the contrary, we clearly detected a significant increase (p<0.001) of miR-196a2 expression in NSCLC. In particular we found a significant association between miR-196a2 CC genotype and high expression, whereas TT geno-type showed a very low expression in comparison to both CT (p<0.005) and CC patients (p<0.01). We did not find any association between miR-149, miR-196a2 and miR-499 genotype and risk of NSCLC. Conversely, CG genotype of miR-146a appeared associated to an increased risk for NSCLC (p=0.042 and 1.77 OR). CONCLUSIONS: Our results seem to demonstrate that sequence variants of miR-196a2 can have an influence on its expression, while miR-146a can have a role in increasing the risk of NSCLC.