A proteomic analysis of the interactions between poly(L-lactic acid) nanofibers and SH-SY5Y neuronal-like cells

Poly (L-lactic acid) (PLLA) is a biodegradable and biocompatible polymer that has been put forward as a promising material for therapeutic approaches aiming to restore neuronal function. The topographic cues present in PLLA-based scaffolds, defined by the technique used in their preparation, have been shown to play a role on the cellular behavior of adherent cells. Even though this interaction has been shown to influence the regenerative output of the scaffold, there is a lack of studies addressing this response at the proteomic level. Hence, this work focuses on the effect of electrospun PLLA-based nanofibers on the proteome, cellular processes and signaling pathways of SH-SY5Y neuroblastoma cells. It also further explores how these molecular mediators might influence cell proliferation and differentiation upon in vitro culture. For that, mass spectrometry followed by bioinformatics analysis was firstly performed and further complemented with Western blot, cell viability and imaging assays. Results show that PLLA nanofibers differentially activate and inhibit specific cellular functions and signaling pathways related to cell division, apoptosis, actin remodeling, among others. These ultimately block cellular proliferation and induce morphological rearrangements through cytoskeleton remodeling, adaptations that turn cells more prone to differentiate. In synthesis, PLLA nanofibers shift the SH-SY5Y cells proteome towards a state more responsive to differentiation-inductive cues such as the retinoic acid. Unveiling cells responses to nanomaterials is an important step to increase the tools available for their manipulation and potentiate their use in neural tissue engineering. Further studies should be performed to compare the effects of other topographic cues on cellular behavior

Monitoring clusterin and fibrillar structures in aging and dementia

Objective: Clusterin is involved in a variety of physiological processes, including proteostasis. Several clusterin polymorphisms were associated with an increased risk of developing Alzheimer’s disease, the world-leading cause of dementia. Herein, the effect of a clusterin polymorphism, aging and dementia in the levels of clusterin in human plasma were analysed in a primary care-based cohort, and the association of this chaperone with fibrillar structures discussed. Methods: 64 individuals with dementia (CDR≥1) and 64 age- and sex-matched Controls from a Portuguese cohort were genotyped for CLU rs1136000 polymorphism, and the plasma levels of clusterin and fibrils were assessed. Results: An increased prevalence of the CC genotype was observed for the dementia group, although no significant robustness was achieved. CLU rs11136000 SNP did not significantly change plasma clusterin levels in demented individuals. Instead, clusterin levels decreased with aging and even more in individuals with dementia. Importantly, plasma clusterin levels correlated with the presence of fibrillar structures in Control individuals, but not in those with dementia. Conclusion: This study reveals a significant decrease in plasma clusterin in demented individuals with aging, which related to altered clusterin-fibrils dynamics. Potentially, plasma clusterin and its association with fibrillar structures can be used to monitor dementia progression along aging

Potential of FTIR spectroscopy applied to exosomes for Alzheimer’s disease discrimination: a pilot study

Alzheimer's disease (AD) diagnosis is based on psychological and imaging tests but can also include monitoring cerebrospinal fluid (CSF) biomarkers. However, CSF based-neurochemical approaches are expensive and invasive, limiting their use to well-equipped settings. In contrast, blood-based biomarkers are minimally invasive, cost-effective, and a widely accessible alternative. Blood-derived exosomes have recently emerged as a reliable AD biomarker source, carrying disease-specific cargo. Fourier-transformed infrared (FTIR) spectroscopy meets the criteria for an ideal diagnostic methodology since it is rapid, easy to implement, and has high reproducibility. This metabolome-based technique is useful for diagnosing a broad range of diseases, although to our knowledge, no reports for FTIR spectroscopy applied to exosomes in AD exist. In this ground-breaking pilot study, FTIR spectra of serum and serum-derived exosomes from two independent cohorts were acquired and analyzed using multivariate analysis. The regional UA-cohort includes 9 individuals, clinically diagnosed with AD, mean age of 78.7 years old; and the UMG-cohort comprises 12 individuals, clinically diagnosed with AD (based on molecular and/or imaging data), mean age of 73.2 years old. Unsupervised principal component analysis of FTIR spectra of serum-derived exosomes revealed higher discriminatory value for AD cases when compared to serum as a whole. Consistently, the partial least-squares analysis revealed that serum-derived exosomes present higher correlations than serum. In addition, the second derivative peak area calculation also revealed significant differences among Controls and AD cases. The results obtained suggest that this methodology can discriminate cases from Controls and thus be potential useful to assist in AD clinical diagnosis.info:eu-repo/semantics/publishedVersio

Development of a library of thiophene-based drug-like LEGO molecules: evaluation of their anion binding, transport properties and cytotoxicity

The anion binding and transport properties of an extensive library of thiophene-based molecules are reported. Seventeen bis-urea positional isomers, with different binding conformations and lipophilicities, were synthetized by the appendage of α-, β-thiophene or α-, β-, γ-benzo[b]thiophene motifs to the ortho-phenylenediamine central core, yielding six subsets of positional isomers. Through 1H NMR, X-ray crystallography, molecular modelling and anion efflux studies, it was demonstrated that the most active transporters display a pre-organised binding conformation able to promote the recognition of chloride using urea and C-H binding groups in a cooperative fashion. Additional LUV based assays, carried out under electroneutral and electrogenic conditions, together with NMDG-Cl assays, indicate that anion efflux occurs mainly through H+/Cl– symport mechanism. On the other hand, the most efficient anion transporter displays cytotoxicity against tumour cell lines while having no effects on a cystic fibrosis cell line