Thioctic acid derivatives as building blocks to incorporate DNA oligonucleotides onto gold nanoparticles

Oligonucleotide gold nanoparticle conjugates are being used as diagnostic tools and gene silencing experiments. Thiol-chemistry is mostly used to functionalize gold nanoparticles with oligonucleotides and to incorporate DNA or RNA molecules onto gold surfaces. However, the stability of such nucleic acid-gold nanoparticle conjugates in certain conditions may be a limitation due to premature break of the thiol-gold bonds followed by aggregation processes. Here, we describe a straightforward synthesis of oligonucleotides carrying thioctic acid moiety based on the use of several thioctic acid-L- Threoninol derivatives containing different spacers, including triglycine, short polyethyleneglycol, or aliphatic spacers. The novel thioctic-oligonucleotides were used for the functionalization of gold nanoparticles and the surface coverage and stability of the resulting thioctic-oligonucleotide gold nanoparticles were assessed. In all cases gold nanoparticles functionalized with thioctic-oligonucleotides had higher loadings and higher stability in the presence of thiols than gold nanoparticles prepared with commercially available thiol-oligonucleotides. Furthermore, the thioctic derivative carrying the triglycine linker is sensitive to cathepsin B present in endosomes. In this way this derivative may be interesting for the cellular delivery of therapeutic oligonucleotides as these results provides the basis for a potential endosomal escape.This work is supported by the European Commission (Grants FP7-NMP-213382-2, FUNMOL and NMP4-LA-2011-262943, MULTIFUN), by the Spanish Ministry of Education (Grant CTQ2010-20541), the Generalitat de Catalunya (2009/SGR/208) and the Instituto de Salud Carlos III (CB06_01_0019). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

Functionalization and Self-Assembly of DNA Bidimensional Arrays

Oligonucleotides carrying amino, thiol groups, as well as fluorescein, c-myc peptide sequence and nanogold at internal positions were prepared and used for the assembly of bidimensional DNA arrays

Modulation of the stability of i-motif structures using an acyclic threoninol cytidine derivative

The effect of aTNA (acyclic threoninol nucleic acids) units on the stability of intramolecular i-motifs was investigated by spectroscopic techniques. The replacement of selected positions of the C-core can modulate the stability at different pH ranges.This work was supported by Spanish Ministry of Economy and Competitiveness (grants CTQ2014-52588-R and CTQ2012-38616-C02-02), the Generalitat de Catalunya (grant 2014 SGR 1106; 2014 SGR 187) and the Communities MULTIFUN (contract NMP4-LA-2011-262943). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Peer reviewe

Synthesis, Cell-Surface Binding, and Cellular Uptake of Fluorescently Labeled Glucose−DNA Conjugates with Different Carbohydrate Presentation

8 páginas, 5 figurasOligonucleotide conjugates carrying carbohydrates at the 5′-end have been prepared. Glucose, fucose, and saccharides containing glucose at the nonreducing end were attached to DNA strands using the classical phosphoramidite chemistry. Two types of spacers and a dendron scaffold helped to obtain a diversity of sugar presentations in the DNA conjugates. Cellular surface adsorption and cellular uptake of carbohydrate oligonucleotide antisense sequences were measured using flow cytometric analysis. Conjugates with the glucose moiety linked through long spacers (15 to 18 atom distances) were internalized better than those with short linkers (4 atom distance) and than DNA control strands without sugar modification. Conjugates with tetravalent presentation of glucose did not improve cell uptake.This work was supported by Consejo Superior de Investigaciones Científicas (PIF06-045); Spanish Ministry of Science (grants BFU2007-63287, BFU2007-62062, CTQ2006-01123,CTQ2009-13705), Generalitat de Catalunya (2009/SGR/208),and Instituto de Salud Carlos III (CIBER-BNN, CB06_01_0019). RL thanks CSIC for a JAE contract.Peer reviewe

Materialidad pictórica. Estudio y percepción de la pintura tardogótica en la actualidad

Estudio con carácter científico e interdisciplinar de los estudios físicos, químicos y visuales de los aspectos materiales e históricos de las pinturas tardogóticas en Castilla, y su difusión a través de las redes sociales de forma visual y didáctica

Lack of Annexin A6 exacerbates liver dysfunction and reduces lifespan of Niemann-Pick type C protein-deficient mice

Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized by cholesterol accumulation caused by loss-of-function mutations in the Npc1 gene. NPC disease primarily affects the brain, causing neuronal damage and affecting motor coordination. In addition, considerable liver malfunction in NPC disease is common. Recently, we found that the depletion of annexin A6 (ANXA6), which is most abundant in the liver and involved in cholesterol transport, ameliorated cholesterol accumulation in Npc1 mutant cells. To evaluate the potential contribution of ANXA6 in the progression of NPC disease, double-knockout mice (Npc1-/-/Anxa6-/-) were generated and examined for lifespan, eurologic and hepatic functions, as well as liver histology and ultrastructure. Interestingly, lack of ANXA6 in NPC1-deficient animals did not prevent the cerebellar degeneration phenotype, but further deteriorated their compromised hepatic functions and reduced their lifespan. Moreover, livers of Npc1-/-/Anxa6-/- mice contained a significantly elevated number of foam cells congesting the sinusoidal space, a feature commonly associated with inflammation. We hypothesize that ANXA6 deficiency in Npc1-/- mice not only does not reverse neurologic and motor dysfunction, but further worsens overall liver function, exacerbating hepatic failure in NPC disease

Stabilization of telomeric i-motif structures by (2'S)-2'-deoxy-2'-C-methyl-cytidine residues

G-quadruplex and i-motif are tetraplex structures present in telomeres and promoter regions of oncogenes. The possibility of producing nanodevices with pH-sensitive functions has triggered the interest for modified oligonucleotides with improved structural properties. We synthesized C-rich oligonucleotides carrying conformationally restricted (2'S)-2'-deoxy-2'-C-methyl-cytidine units. The effect of this modified nucleoside on the stability of intramolecular i-motifs related to vertebrate telomere was investigated by means of spectroscopic methods (UV, CD and NMR). The replacement of selected positions of the C-core by the appropriate C-modified residues induces the formation of stable intercalated tetraplexes at pHs near neutrality. The study demonstrates the possibility of enhancing the stability of i-motif by chemical modifications

A randomized, double-blind study on the efficacy of oral domperidone versus placebo for reducing SARS-CoV-2 viral load in mild-to-moderate COVID-19 patients in primary health care

15 p.-3 fig.-3 tab.Introduction:The clinical effect of domperidone against COVID-19 has been investigated in a double-blind phase III clinical trial (EudraCT number 2021-001228-17). Domperidone has shown in vitro antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential immudolatory properties through the stimulation of prolactin secretion.Patients and methods:The efficacy of oral domperidone plus standard of care (SOC; n = 87) versus placebo plus SOC (n = 86) was evaluated in a 28-day randomized double-blind multicentre study in primary health care centres. A total of 173 outpatients with mild-to-moderate COVID-19 were included. Three daily doses of 10 mg (30 mg/day) of domperidone or placebo were administered for 7 days. Reduction of viral load on day 4 was the primary efficay endpoint. It was estimated in saliva samples by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), as the cycle thresholds detected ORF1ab, N Protein and S Protein genes.Results:A significant reduction in the viral load was observed (p < 0.001) from baseline to days 4, 7 and 14 of the three genes studied with non-significant differences between domperidone and placebo groups. Twenty-three patients (13.3%) experienced adverse events, 14 patients in the domperidone group (16.1%) and 9 patients in the placebo group (10.5%). No patients needed to be hospitalized.Conclusion: Results do not prove the use of domperidone as antiviral in patients with COVID-19.This research was funded by CSIC (grant no. PIE 201980E024) and by the European Commission: NextGeneration EU (Regulation EU 2020/2094) through CSIC’s Global Health Platform (PTI Salud Global). The study sponsor was Agencia Estatal Consejo Superior de Investigaciones Científicas, M.P. (CSIC), Madrid, Spain. The sponsor was involved in the design, data interpretation, manuscript review and the decision to submit the article for publication.Peer reviewe