Origin of the myotonic dystrophy type 1 mutation in Mexican population and influence of Amerindian ancestry on CTG repeat allelic distribution

Myotonic dystrophy type 1 is caused by expansion of a CTG trinucleotide repeat situated in the DMPK gene. Worldwide genetic studies suggest a single or limited number of mutational events cause the disease. However, distribution of CTG alleles and disease incidence varies among ethnicities. Due to the great ethnic diversity of the Mexican population, the present study was aimed at analyzing the impact of different lineages in shaping the CTG-repeat allelic distribution in the contemporary Mexican-Mestizo population as well as to shed light on the DM1 ancestral origin. Distribution of CTG-repeat alleles was similar among Mestizo and Amerindian subpopulations with (CTG)_11-13 being the most frequent alleles in both groups, which implies that Mexican-Mestizo allelic distribution has been modeled by Amerindian ancestry. We diagnosed a relatively high number of cases, consistent with the high frequency of large-normal alleles found in Mexican subpopulations. Haplotype analysis using various polymorphic-markers in proximity to DMPK gene indicates that a single founder mutation originates myotonic dystrophy type 1 in Mexico; however, Y-STR haplogroups data and the presence of pre-mutated and large normal alleles in Amerindians support the hypothesis that both European and Amerindian ancestral chromosomes might have introduced the disease to the Mexican population, which was further disseminated through mestizaje.

Corticoids synergize with IL-1 in the induction of LCN2

OBJECTIVE

Lipocalin-2 (LCN2) is an adipokine that was first identified in neutrophil granules. In the last years it was recognized as a factor that could impair chondrocyte phenotype, cartilage homeostasis as well as growth plate development. Both pro-inflammatory cytokines and glucocorticoids (GCs) modulate LCN2 expression. Actually, GCs were found to be LCN2 inducers, suggesting that part of the negative actions exerted by these anti-inflammatory drugs at cartilage level could be mediated by this adipokine. So, in this study we wanted to investigate whether corticoids were able to act in synergy with IL-1 in the induction of LCN2 and the signaling pathway involved in this process.

MATERIALS AND METHODS

For the realization of this work, ATDC5 mouse chondrogenic cell line was used. We determined the mRNA and protein expression of LCN2 by real-time reverse transcription-polymerase chain reaction (RT-qPCR) and western blot respectively, after GC or mineralcorticoid treatment. Different signaling pathways inhibitors were also used.

RESULTS

GC and mineralcorticoid were able to induce the expression of LCN2 in ATDC5 cells. Interestingly, both corticoids synergized with IL-1 in the induction of LCN2. The effect of these corticoids on the expression of LCN2 occurred through GC or mineralcorticoid receptors and the kinases PI3K, ERK1/2 and JAK2.

CONCLUSIONS

Prolonged use of corticoids may have detrimental effects on cartilage homeostasis. Based on our results, we conclude that corticoids could increase the negative actions exerted by IL-1 by increasing the expression of LCN2.

Regeneration of three pine species in a Mediterranean forest: A study to test predictions from species distribution models under changing climates

The study tested the hypothesis that future changes in the composition of tree communities, as predicted by species distribution models, could already be apparent in the current regeneration patterns of three pine species (Pinus pinaster, P. nigra and P. sylvestris)inhabiting the central-eastern mountains of Spain. We carried out both an observational study and a seed-sowing experiment to analyze, along an altitudinal and latitudinal gradient, whether recent recruitment patterns indicate an expansion of P. pinaster forests to the detriment of P. nigra ones in the low-altitude southern sites of these mountains; or whether P. sylvestris is being replaced by P. nigra in the high-altitude sites from the same area. The observational study gathered data from 561 plots of the Spanish National Forest Inventory. The seed-sowing experiment tested the effects of irrigation and stand basal area on seedling emergence and survival. Data were analyzed by means of Generalized Linear Models and Generalized Linear Mixed Models. Regeneration of the three pine species responded similarly to the explicative factors studied, but the density of tree seedlings and saplings exhibited a wide spatial heterogeneity. This result suggested that a mosaic of site- and species-specific responses to climate change might mislead model projections on the future forest occupancy of tree species. Yet, we found no indications of neither an expansion nor a contraction of the near future forest occupancy of the tree species studied.

[Randomised clinical trial to evaluate the efficacy and safety of a new pediculicide made with saponified olive oil in the eradication of Pediculus humanus capitis]

INTRODUCTION

The aim of the study was to evaluate the efficacy and safety of a new pediculicide in the eradication of Pediculus humanus capitis infestation.

MATERIAL AND METHODS

A randomised clinical trial was designed, in which children aged between 5 and 15 years diagnosed with pediculosis were selected. Treatment was administered on days 1 and 7 after selection, and they were evaluated in 4 visits (day 2, 7, 9, and 14). The product under evaluation with saponified olive oil was Inex Pediculicide Soap^®, which was compared with Paranix^®, with a similar mechanism of action. The primary efficacy endpoint was the eradication of the parasite by day 14 (louse-free rate), using an intention to treat analysis.

RESULTS

Six paediatricians from 5 Primary Health Care centres in the Community of Madrid (Spain) and one private clinic participated in the study. A total of 45 children were included, of which 75.6% were girls (n=34). The mean age was 7.1 years (95% CI 6.3-7.9). The large majority (80%) were middle class, and 82.2% had a history of previous pediculosis. The efficacy at 14 days was 76.2% (95% CI 52.8-91.8) in the group treated with Inex Pediculicide Soap^® group, and 79.2% (95% CI 57.9-92.9) in Paranix^® group (NNT=33.3). No adverse effects were observed with treatment.

CONCLUSIONS

The 2 products were effective and safe in the eradication therapy Pediculus humanus capitis, with no statistical differences.

Novel Water-Soluble Mucoadhesive Carbosilane Dendrimers for Ocular Administration

The purpose of this research was to determine the potential use of water-soluble anionic and cationic carbosilane dendrimers (generations 1-3) as mucoadhesive polymers in eyedrop formulations. Cationic carbosilane dendrimers decorated with ammonium -NH3(+) groups were prepared by hydrosylilation of Boc-protected allylamine and followed by deprotection with HCl. Anionic carbosilane dendrimers with terminal carboxylate groups were also employed in this study. In vitro and in vivo tolerance studies were performed in human ocular epithelial cell lines and rabbit eyes respectively. The interaction of dendrimers with transmembrane ocular mucins was evaluated with a surface biosensor. As proof of concept, the hypotensive effect of a carbosilane dendrimer eyedrop formulation containing acetazolamide (ACZ), a poorly water-soluble drug with limited ocular penetration, was tested after instillation in normotensive rabbits. The methodology used to synthesize cationic dendrimers avoids the difficulty of obtaining neutral -NH2 dendrimers that require harsher reaction conditions and also present high aggregation tendency. Tolerance studies demonstrated that both prototypes of water-soluble anionic and cationic carbosilane dendrimers were well tolerated in a range of concentrations between 5 and 10 μM. Permanent interactions between cationic carbosilane dendrimers and ocular mucins were observed using biosensor assays, predominantly for the generation-three (G3) dendrimer. An eyedrop formulation containing G3 cationic carbosilane dendrimers (5 μM) and ACZ (0.07%) (289.4 mOsm; 5.6 pH; 41.7 mN/m) induced a rapid (onset time 1 h) and extended (up to 7 h) hypotensive effect, and led to a significant increment in the efficacy determined by AUC0(8h) and maximal intraocular pressure reduction. This work takes advantage of the high-affinity interaction between cationic carbosilane dendrimers and ocular transmembrane mucins, as well as the tensioactive behavior observed for these polymers. Our results indicate that low amounts of cationic carbosilane dendrimers are well tolerated and able to improve the hypotensive effect of an acetazolamide solution. Our results suggest that carbosilane dendrimers can be used in a safe range of concentrations to enhance the bioavailability of drugs topically administered in the eye.

In vitro anti-Acanthamoeba synergistic effect of chlorhexidine and cationic carbosilane dendrimers against both trophozoite and cyst forms

Acanthamoeba sp. are the causative agents of severe illnesses in humans such as Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). Medical therapy is not yet well established. Treatments of AK last for several months and generate toxicity, resistances appear due to the cysts stage and recurrences can occur. In this study has been demonstrated that the combination of chlorhexidine digluconate (CLX) and carbosilane dendrimers containing ammonium or guanidine moieties has in vitro synergistic effect against Acanthamoeba polyphaga. This synergy provokes an important reduction in the minimal trophozoite amoebicidal concentration (MTAC) of CLX, which means a reduction of their toxic effects on human cells. Moreover, some CLX/dendrimer combinations show important activity against the cyst resistance stage.

Photocatalytic Degradation of Phenol Using Al2O3-SnO2 Mixed Oxide

Al2O3 and SnO2 mixed oxide were obtained by the coprecipitation method at different Sn4+ contents, from the urea hydrolysis at 95 degrees C using nitrate salt as metal precursor. The studies of X-ray diffraction and reflectance diffuse UV-Vis spectroscopies and N2 adsorption-desorption show important changes. The photocatalytic efficiency test for the mineralization of phenol was determined from UV-Vis spectroscopy. The Al2O3-SnO2 mixed oxide with 10% mol of Sn4+ improved the photocatalytic activity in the elimination of phenol under UV light irradiation, where the photodegradation rate was 2 times more active than Al2O3 unmodified and 1.4 times more active than the reference photocatalyst TiO2-P25. The high activity observed was discussed as a function of the small particle size of SnO2.

Ultrasound-assisted selective hydrogenation of C-5 acetylene alcohols with Lindlar catalysts

The selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) was performed in the presence of Lindlar catalyst, comparing conventional stirring with sonication at different frequencies of 40, 380 and 850 kHz. Under conventional stirring, the reaction rates were limited by intrinsic kinetics, while in the case of sonication, the reaction rates were 50-90% slower. However, the apparent reaction rates were found to be significantly frequency dependent with the highest rate observed at 40 kHz. The original and the recovered catalysts after the hydrogenation reaction were compared using bulk elemental analysis, powder X-ray diffraction and scanning and transmission electron microscopy coupled with energy-dispersive X-ray analysis. The studies showed that sonication led to the frequency-dependent fracturing of polycrystalline support particles with the highest impact caused by 40 kHz sonication, while monocrystals were undamaged. In contrast, the leaching of Pd/Pb particles did not depend on the frequency, which suggests that sonication removed only loosely-bound catalyst particles.

Optimizing CIGB-300 intralesional delivery in locally advanced cervical cancer

BACKGROUND

We conducted a phase 1 trial in patients with locally advanced cervical cancer by injecting 0.5 ml of the CK2-antagonist CIGB-300 in two different sites on tumours to assess tumour uptake, safety, pharmacodynamic activity and identify the recommended dose.

METHODS

Fourteen patients were treated with intralesional injections containing 35 or 70 mg of CIGB-300 in three alternate cycles of three consecutive days each before standard chemoradiotherapy. Tumour uptake was determined using (99)Tc-radiolabelled peptide. In situ B23/nucleophosmin was determined by immunohistochemistry.

RESULTS

Maximum tumour uptake for CIGB-300 70-mg dose was significantly higher than the one observed for 35 mg: 16.1 ± 8.9 vs 31.3 ± 12.9 mg (P = 0.01). Both, AUC24h and biological half-life were also significantly higher using 70 mg of CIGB-300 (P < 0.001). Unincorporated CIGB-300 diffused rapidly to blood and was mainly distributed towards kidneys, and marginally in liver, lungs, heart and spleen. There was no DLT and moderate allergic-like reactions were the most common systemic side effect with strong correlation between unincorporated CIGB-300 and histamine levels in blood. CIGB-300, 70 mg, downregulated B23/nucleophosmin (P = 0.03) in tumour specimens.

CONCLUSION

Intralesional injections of 70 mg CIGB-300 in two sites (0.5 ml per injection) and this treatment plan are recommended to be evaluated in phase 2 studies.

Interethnic variation of the MMP-9 microsatellite in Amerindian and Mexican Mestizo populations: considerations for genetic association studies

We studied the interethnic variation of the MMP-9 microsatellite in the Mestizo and Amerindian populations using blood samples collected from 435 healthy unrelated individuals from the Central Valley of Mexico. DNA samples were genotyped using the -90 (CA)12-27 repeat near the MMP transcriptional start site using capillary electrophoresis. Our data were compared with those from African, Asian, and European populations (N = 729). Both Mestizo and Amerindian populations were in Hardy-Weinberg equilibrium (P ≥ 0.05). However, strong genetic heterogeneity was found within the Mestizo population (94%, P ≤ 0.0001), which exhibited the highest frequency of Amerindian, African, and European alleles. Likewise, Amerindians showed 6.7% variation among populations (P ≤ 0.0001), suggesting a genetic substructure potentially associated with linguistic affiliations. These findings were corroborated with principal component and population differentiation analyses, which showed relative proximity among the Mestizos and their historical parental populations: Asian (FST ≥ 0.05), European (FST ≥ 0.09), and African (FST ≥ 0.02). Nevertheless, important differences were found between Mestizo and Nahuas (P ≤ 0.0001), and between Mestizo and Me'Phaas (P ≤ 0.0001). These findings highlight the importance of determining local-specific patterns to establish the population variability of MMP-9 and other polymorphic markers. Validation of candidate markers is critical to identifying risk factors; however, this depends on knowledge of population genetic variation, which increases the possibility of finding true causative variants. We also show that dissimilar ethnic backgrounds might lead to spurious associations. Our study provides useful considerations for greater accuracy and robustness in future genetic association studies.

Expression of NAT2 in immune system cells and the relation of NAT2 gene polymorphisms in the anti-tuberculosis therapy in Mexican mestizo population

Arylamine N-acetyltransferase 2 (NAT2) metabolizes isoniazid (INH) and Single Nucleotide Polymorphisms (SNP) responsible for its activity has been reported. The aim of this study in the Mexican mestizo population was to evaluate NAT2 expression at the protein level in immune cells, as well as the distribution and frequency of six NAT2 SNPs and their association with anti-TB therapy, by measuring the plasma levels of INH and Acetyl-INH (AcINH). We performed genotyping assays of NAT2 SNPs in 40 TB patients and 121 healthy volunteers by real-time PCR. A method for detecting NAT2 in immune cells using flow cytometry was developed. Plasma concentrations of INH and AcINH were obtained by HPLC in TB patients and the Metabolic Ratio (MR) was calculated. The phenotypes obtained in the healthy volunteers were as follows; 18.87 % of subjects had the rapid acetylator phenotype, 45.45 % had the intermediate phenotype and 39.66 % exhibited the slow acetylator phenotype. In the TB patient group, 35 % of patients had the rapid acetylator phenotype, 32.5 % were intermediate and 32.5 % showed the slow acetylator phenotype. A higher expression level of NAT2 in innate immune cells from TB patients compared to those from healthy volunteers was detected (P < 0.013). In TB patients the MR showed a bimodal distribution with an antimode of 0.7, which was used as a threshold value for acetylator classification. A high correspondence between the rapid and slow acetylator phenotype with MR was demonstrated. In conclusion, the 282C>T, 341T>C, 481C>T, 590G>A, 803A>G, 857G>A SNPs of NAT2 gene provides accurate for prediction of the acetylator phenotype in Mexican mestizo population. A statistical difference was found in frequency of rapid metabolizer phenotype, which was higher in TB patients. In addition, the expression of NAT2 protein in immune cells can lead to further studies related to its functional role in the innate immune response against M. tuberculosis and other xenobiotics metabolized by this enzyme.

Inhibition of Delta-like 4 mediated signaling induces abortion in mice due to deregulation of decidual angiogenesis

OBJECTIVE

To explore whether the Dll4/Notch1 pathway plays a key role in regulating the vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) driven decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype.

METHODS

Progesterone-replaced ovariectomized pregnant mice received a single injection of YW152F (Dll4 blocking antibody, BAb) or placebo at embryonic day (E) 4.5. Animals were sacrificed at different time points; blood and uterus were collected for further analysis. Number of embryos and implantation site, uteri weight, and serum progesterone levels were assessed. Alterations in the tip/stalk phenotype were determined by quantitative immunofluorescent analysis of vascularization, Dll4 expression, cellular proliferation and apoptosis in uterine sections.

RESULTS

Abrogation of Dll4 signaling leads to a promiscuous expression of Dll4, increased cell proliferation, apoptosis and vascularization at E 6.5. Such an abrogation was associated with a dramatic disruption of embryo growth and development starting at E 9.5.

DISCUSSION

The observed promiscuous expression of Dll4 and the increase in cell proliferation, apoptosis and vascularization are events compatible with loss of the tip/stalk phenotype. Excessive (although very likely defective) decidual angiogenesis due to such vascular alterations is the most likely cause of subsequent interruption of embryo development and related pregnancy in Dll4 treated mice.

CONCLUSIONS

Dll4 plays a key role in regulating decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype.