Premature primary tooth eruption in cognitive/motor-delayed ADNP-mutated children

This corrects the article DOI: 10.1038/tp.2017.27.

Premature primary tooth eruption in cognitive/motor-delayed ADNP-mutated children

A major flaw in autism spectrum disorder (ASD) management is late diagnosis. Activity-dependent neuroprotective protein (ADNP) is a most frequent de novo mutated ASD-related gene. Functionally, ADNP protects nerve cells against electrical blockade. In mice, complete Adnp deficiency results in dysregulation of over 400 genes and failure to form a brain. Adnp haploinsufficiency results in cognitive and social deficiencies coupled to sex- and age-dependent deficits in the key microtubule and ion channel pathways. Here, collaborating with parents/caregivers globally, we discovered premature tooth eruption as a potential early diagnostic biomarker for ADNP mutation. The parents of 44/54 ADNP-mutated children reported an almost full erupted dentition by 1 year of age, including molars and only 10 of the children had teeth within the normal developmental time range. Looking at Adnp-deficient mice, by computed tomography, showed significantly smaller dental sacs and tooth buds at 5 days of age in the deficient mice compared to littermate controls. There was only trending at 2 days, implicating age-dependent dysregulation of teething in Adnp-deficient mice. Allen Atlas analysis showed Adnp expression in the jaw area. RNA sequencing (RNAseq) and gene array analysis of human ADNP-mutated lymphoblastoids, whole-mouse embryos and mouse brains identified dysregulation of bone/nervous system-controlling genes resulting from ADNP mutation/deficiency (for example, BMP1 and BMP4). AKAP6, discovered here as a major gene regulated by ADNP, also links cognition and bone maintenance. To the best of our knowledge, this is the first time that early primary (deciduous) teething is related to the ADNP syndrome, providing for early/simple diagnosis and paving the path to early intervention/specialized treatment plan.

NAP has no effect on spatial memory after short-term treatment in advanced stage Alzheimer's disease mouse model

NAPVSIPQ (NAP) is a small, active fragment of activity-dependent neuroprotective protein that has neuroprotective and memory enhancing properties at very low concentrations. Previous research demonstrated that 1-2 weeks of treatment provided memory enhancing effects in normal middle-aged and cholinergically lesioned rats. Improvement in cognitive performance was shown in 12-month-old C57Bl6/J mice after 10 days of oral treatment with D-NAP and D-SALLRSIPA. Additionally, NAP-related cognitive benefits on spatial memory were observed in a 3xTg Alzheimer mouse model after 6 months of chronic administration at a moderate stage of disease. In this study, the potential memory enhancing effect of NAP was investigated using the APP23 transgenic mouse model for Alzheimer's disease. Twelve-month-old male heterozygous APP23 mice and their wild-type control littermates were intraperitoneally injected with 0.3 microg NAP/g body weight or with saline vehicle for 22 consecutive days. Cognitive performance training in the Morris Water Maze (MWM) started on day 8 of treatment. The internal validity of our study was demonstrated by the fact that the APP23 mice performed significantly worse in the MWM than wild-type animals. Treatment with NAP, however, did not exert any significant effects on MWM performance. Although we failed to show significant memory enhancing effects in this study, NAP might be a promising peptide for disease-modifying therapy in neurodegenerative disease, but short-term effects are probably not to be expected. Also, most likely, treatment should start in an early stage, i.e. before full-blown pathology is eminent, and the necessary treatment period should enclose several months.

Usefulness of a novel Caco-2 cell perfusion system II. Characterization of monolayer properties and peptidase activity

In this study, the enzymatic activity and the influence of support filters and extracellular matrix proteins on the differentiation of Caco-2 cells grown in a perfusion system (Minucells and MinutissueTM) were examined and compared to traditional culturing approaches. Differences were observed regarding the differentiation of Caco-2 cells using the traditional approach and perfusion system such that the cell monolayers grown in a perfusion system showed a significant increase in dipeptidase activities (18.20 +/- 0.43nmol x min(-1) x cm(-2)) compared to the cells cultivated using the 21-day protocol (9.45 +/- 0.50 nmol x min(-1) x cm(-2)). The peptidase activity of Caco-2 cells was strikingly inhibited when Matrigel extracellular protein was used for coating polycarbonate support filters. While the enzymatic activities of the cell monolayers differentiated in the perfusion system were up-regulated, the transepithelial electrical resistance values of the cell monolayers (171 +/- 52 and 251 +/- 62 omega x cm2 for polycarbonate and polyester, respectively) decreased compared to the traditional Snapwell inserts (644 +/- 119 omega x cm2). The results suggested that the perfusion systems were useful permeability models which reduce workload, resources and manpower needed to obtain useful Caco-2 monolayers. In addition, the approach offers an efficient tool for long-term culturing of highly differentiated Caco-2 cell monolayers.

Parallel artificial membrane permeability assay (PAMPA) combined with a 10-day multiscreen Caco-2 cell culture as a tool for assessing new drug candidates

The parallel artificial membrane permeability assay (PAMPA) is extensively used for the evaluation of early drug candidates. It is high throughput, low cost and is amenable to automation. This method has been shown useful in assessing transmembrane, non-energy dependent, diffusion of drugs such that reasonable predictability with in vivo (passive) absorption is possible. Cell cultures mimicking the gastrointestinal tract such as the CACO-2 cultures have the advantage of taking into account other transport mechanism including paracellular and carrier-mediated uptake but are lower throughput and labor-intensive. In this study, the applicability of two high throughput permeability assays namely PAMPA (PSR4p, pION Inc.) and 96-well Caco-2 cell assay (MultiScreen, Millipore) were used to rank drug permeability as well as to predict passive and active drug absorption/secretion for a series of marketed drugs as well as a collection of structurally diverse drug candidates. CACO-2 cells were cultured using MultiScreen hardware over a period of 10 days with the integrity of the cells assessed using transepithelial electrical resistance (TEER) and by the ability of the monolayer to the transport a paracellular marker, sodium fluorescence. Effective permeability (Peff) data were calculated using spectrophotometric data and were binned based on a pre-defined cut-off values as either highly and poorly permeable. A comparison of a well characterized drug training set indicate at least 85% concordance between the data generated from PAMPA and Caco-2 MultiScreen. The values obtained using the MultiScreen approach were also similar to data obtained from the literature using the conventional 21-day Caco-2 cell assay. Differences between PAMPA and CACO-2 ranking were useful indicators of either drug efflux (PAMPA (Peff) > CACO-2 (Peff)) or absorptive transport (CACO-2 (Peff) > PAMPA (Peff)). These results indicate that PAMPA combined with the MultiScreen Caco-2 cell culture may be a useful high throughput screening for predicting passive diffusion and active transport of new drugs.

Delivery of a DNAzyme targeting c-myc to HT29 colon carcinoma cells using a gold nanoparticulate approach

The objective of the current study was to develop cellular delivery approaches for catalytic DNA enzymes (DNAzymes) which cleave targeted messenger RNA, using vectors based on colloidal gold. The model DNAzyme was a 32mer oligonucleotide designed to specifically interact with and cleave c-myc mRNA. Colloidal gold particles were prepared by reduction of tetrachlororauric [III] acid with sodium citrate. Particles could be produced in the 1-90 nm range. A cationic substrate linked to transferrin was electrostatically/hydrophobically bound to the gold particle. These vectors were then treated with the DNAzyme to yield the condensed DNA-cationic polymer-particulate product. The pH (4-11.5), the quantity of the DNAzymes (0.079-0.567 microg/probe), the cationic polymer (polylysine (PL) or polyethylenimine (PEI)) as well as the surfactant (PVP) concentration (0-0.5%) were varied to give stable constructs which decomplexed under the desired conditions (i.e., in lysosomes and at lower pH values). Cellular uptake of the FITC-labelled c-myc DNAzyme incorporated in this vector was measured using FACS analysis in human HT29 colon carcinoma cells. Data suggested that PEI gave better delivery efficiencies than PL. The use of PVP to stabilize the formed dispersions was detrimental to DNAzyme delivery when PL was used but had little effect in the PEI systems. In the best cases, delivery to 77% of the cells was possible using PEI with the PVP stabilizer and completing the DNA condensation at pH 5.5 with 0.118 microg of DNAzyme/probe. In contrast, the best conditions for PL gave only transfection to 43% of the cells (no PVP, condensed at pH 5.7 and with a loading of 0.079 microg DNAzyme/probe). The PL probe tended to be more toxic than the PEI-based systems (65% cell death in PL transfected cells compared to 22% for PEI). These results suggest that cellular targeting using colloidal gold appears feasible for DNAzyme delivery.

The use of polymer-based electrospun nanofibers containing amorphous drug dispersions for the delivery of poorly water-soluble pharmaceuticals

Electrostatic spinning was applied to the preparation of drug-laden nanofiber for potential use in oral and topical drug delivery. While this technique is in its infancy with regard to pharmaceutical applications, a number of recent publications suggest that it may be of high value in the formulation of poorly water-soluble drugs by combining nanotechnology and solid solution/dispersion methodologies. The purpose of this article is to describe some of these recently published applications. For immediate release oral application, a water-soluble cellulose polymer was selected (i.e., hydroxypropylmethylcellulose, HPMC) while for topical application, a nonbiodegradable, water-insoluble polymer was investigated (i.e., a segmented polyurethane, SPU). Solutions of the polymer and the drugs in appropriate solvents could be spun across various potentials (16-24 kV) generating nanofibers with diameters ranging from 300 to 2000 nm. Dissolution studies found that the non-woven fabrics derived from HPMC and containing itraconazole dissolved over a time course of minutes to hours depending on the formulation used as well as the drug/polymer ratios. Drug release from the SPU samples was dependent on the incorporated drug as well as nanostructure obtained.

Sensitive visualization of antigen-antibody reactions in dot and blot immune overlay assays with immunogold and immunogold/silver staining

The use of colloidal gold and colloidal gold followed by silver enhancement as marker for dot or blot immune overlays is described. Colloidal gold probes concentrating at the sites of immune reaction gradually develop a pinkish colour during incubation that can be seen with the naked eye. With a physical developer, very high sensitivity and contrast is obtained by silver precipitation on the gold marker. Comparison of the immunogold and immunogold/silver staining methods with the indirect, PAP and ABC immunoperoxidase methods demonstrates that colloidal gold probes are excellent markers for immune overlay assays.