Mutational mechanism for DAB1 (ATTTC) n insertion in SCA37: ATTTT repeat lengthening and nucleotide substitution

Dynamic mutations by microsatellite instability are the molecular basis of a growing number of neuromuscular and neurodegenerative diseases. Repetitive stretches in the human genome may drive pathogenicity, either by expansion above a given threshold, or by insertion of abnormal tracts in nonpathogenic polymorphic repetitive regions, as is the case in spinocerebellar ataxia type 37 (SCA37). We have recently established that this neurodegenerative disease is caused by an (ATTTC)n insertion within an (ATTTT)n in a noncoding region of DAB1. We now investigated the mutational mechanism that originated the (ATTTC)n insertion within an ancestral (ATTTT)n . Approximately 3% of nonpathogenic (ATTTT)n alleles are interspersed by AT-rich motifs, contrarily to mutant alleles that are composed of pure (ATTTT)n and (ATTTC)n stretches. Haplotype studies in unaffected chromosomes suggested that the primary mutational mechanism, leading to the (ATTTC)n insertion, was likely one or more T>C substitutions in an (ATTTT)n pure allele of approximately 200 repeats. Then, the (ATTTC)n expanded in size, originating a deleterious allele in DAB1 that leads to SCA37. This is likely the mutational mechanism in three similar (TTTCA)n insertions responsible for familial myoclonic epilepsy. Because (ATTTT)n tracts are frequent in the human genome, many loci could be at risk for this mutational process.We are grateful to the families and individuals who participated in this work. We thank Patricia Ribeiro for technical assistance. This study was financed by Fundo Europeu de Desenvolvimento Regional (FEDER), through the COMPETE 2020 Operational Pro- gram for Competitiveness and Internationalization (POCI) of Portugal 2020, and by the Fundacão para a Ciência e a Tecnologia (FCT) and Ministério da Ciência, Tecnologia e Ensino Superior (Portugal), in the framework of the project POCI-01-0145-FEDER-029255; (PTDC/MED-GEN/29255/2017) to I.S. J.R.L. and C.L.O. were sup- ported by scholarships from PEst-C/SAU/LA0002/2013. S.M. is funded by the project IF/00930/2013/ CP1184/CT0002 from FCT. This work was also funded by the Porto Neurosciences and Neurologic Disease Research Initiative at the Instituto de Investigação e Inovação em Saúde (Norte-01-0145-FEDER- 000008), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTU- GAL 2020 Partnership Agreement with FEDER

A pentanucleotide ATTTC repeat insertion in the non-coding region of DAB1, mapping to SCA37, causes spinocerebellar ataxia.

Advances in human genetics in recent years have largely been driven by next-generation sequencing (NGS); however, the discovery of disease-related gene mutations has been biased toward the exome because the large and very repetitive regions that characterize the non-coding genome remain difficult to reach by that technology. For autosomal-dominant spinocerebellar ataxias (SCAs), 28 genes have been identified, but only five SCAs originate from non-coding mutations. Over half of SCA-affected families, however, remain without a genetic diagnosis. We used genome-wide linkage analysis, NGS, and repeat analysis to identify an (ATTTC)n insertion in a polymorphic ATTTT repeat in DAB1 in chromosomal region 1p32.2 as the cause of autosomal-dominant SCA; this region has been previously linked to SCA37. The non-pathogenic and pathogenic alleles have the configurations [(ATTTT)7-400] and [(ATTTT)60-79(ATTTC)31-75(ATTTT)58-90], respectively. (ATTTC)n insertions are present on a distinct haplotype and show an inverse correlation between size and age of onset. In the DAB1-oriented strand, (ATTTC)n is located in 5' UTR introns of cerebellar-specific transcripts arising mostly during human fetal brain development from the usage of alternative promoters, but it is maintained in the adult cerebellum. Overexpression of the transfected (ATTTC)58 insertion, but not (ATTTT)n, leads to abnormal nuclear RNA accumulation. Zebrafish embryos injected with RNA of the (AUUUC)58 insertion, but not (AUUUU)n, showed lethal developmental malformations. Together, these results establish an unstable repeat insertion in DAB1 as a cause of cerebellar degeneration; on the basis of the genetic and phenotypic evidence, we propose this mutation as the molecular basis for SCA37.We thank the families who participated in this study. We are grateful to Goncalo Abecasis, Miguel Costa, Tito Vieira, and Andre Torres for help with MERLIN analysis; Beatriz Sobrino, Jorge Amigo, and Pilar Cacheiro for next-generation sequencing analysis, performed at the Santiago de Compostela node of the Spanish National Genotyping Center; Nuno Santarem and Anabela Cordeiro-da-Silva for assistance with cloning; Antonio Amorim, Laura Vilarinho, and Paula Jorge for samples from the Portuguese population; and Paula Magalhaes from the Institute for Molecular and Cell Biology Cell Culture and Genotyping Core for DNA extraction. This work was financed by Fundo Europeu de Desenvolvimento Regional (FEDER) funds through the COMPETE 2020 Operational Program for Competitiveness and Internationalization (POCI) of Portugal 2020 and by Portuguese funds through the Fundacao para a Ciencia e a Tecnologia (FCT) and Ministerio da Ciencia, Tecnologia, e Inovacao in the framework of the project "Institute for Research and Innovation in Health Sciences" (POCI-01-0145-FEDER-007274); and by FCT grant PTDC/SAU-GMG/098305/2008 to I.S. A. I.S. was the recipient of an FCT scholarship (SFRH/BD/30702/2006). J.R.L. was supported by scholarships from PEst-C/SAU/LA0002/2013 and the European Molecular Biology Organization (ASTF494-2015). C.L.O. was supported by a scholarship from PEst-C/SAU/LA0002/2013. This work was also financed by the Porto Neurosciences and Neurologic Disease Research Initiative at the Instituto de Investigacao e Inovacao em Saude (Norte-01-0145-FEDER-000008), supported by Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement through FEDER, and by the Fondo de Investigacion Sanitaria of the Instituto de Salud Carlos III (grant PI12/00742)

Hypertension Is Associated With Intestinal Microbiota Dysbiosis and Inflammation in a Brazilian Population

Hypertension is a major global health challenge, as it represents the main risk factor for stroke and cardiovascular disease. It is a multifactorial clinical condition characterized by high and sustained levels of blood pressure, likely resulting from a complex interplay of endogenous and environmental factors. The gut microbiota has been strongly supposed to be involved but its role in hypertension is still poorly understood. In an attempt to fill this gap, here we characterized the microbial composition of fecal samples from 48 hypertensive and 32 normotensive Brazilian individuals by next-generation sequencing of the 16S rRNA gene. In addition, the cytokine production of peripheral blood samples was investigated to build an immunological profile of these individuals. We identified a dysbiosis of the intestinal microbiota in hypertensive subjects, featured by reduced biodiversity and distinct bacterial signatures compared with the normotensive counterpart. Along with a reduction in Bacteroidetes members, hypertensive individuals were indeed mainly characterized by increased proportions of Lactobacillus and Akkermansia while decreased relative abundances of well-known butyrate-producing commensals, including Roseburia and Faecalibacterium within the Lachnospiraceae and Ruminococcaceae families. We also observed an inflamed immune profile in hypertensive individuals with an increase in TNF/IFN-\u3b3 ratio, and in TNF and IL-6 production when compared to normotensive ones. Our work provides the first evidence of association of hypertension with altered gut microbiota and inflammation in a Brazilian population. While lending support to the existence of potential microbial signatures of hypertension, likely to be robust to age and geography, our findings point to largely neglected bacteria as potential contributors to intestinal homeostasis loss and emphasize the high vulnerability of hypertensive individuals to inflammation-related disorders

Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

We analyze the one-loop vacuum stability and perturbativity bounds on a singlet extension of the Standard Model (SM) scalar sector containing a scalar dark matter candidate. We show that the presence of the singlet-doublet quartic interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a function of the cutoff and lowers the corresponding upper bound based on perturbativity considerations. We also find that vacuum stability requirements may place a lower bound on the singlet dark matter mass for given singlet quartic self coupling, leading to restrictions on the parameter space consistent with the observed relic density. We argue that discovery of a light singlet scalar dark matter particle could provide indirect information on the singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text discussions of other references, changed coloring of figures for easier black and white viewin

Using an oblique incident laser beam to measure the optical properties of stomach mucosa/submucosa tissue

<p>Abstract</p> <p>Background</p> <p>The purpose of the study is to determine the optical properties and their differences for normal human stomach mucosa/submucosa tissue in the cardiac orifice <it>in vitro </it>at 635, 730, 808, 890 and 980 nm wavelengths of laser.</p> <p>Methods</p> <p>The measurements were performed using a CCD detector, and the optical properties were assessed from the measurements using the spatially resolved reflectance, and nonlinear fitting of diffusion equation.</p> <p>Results</p> <p>The results of measurement showed that the absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at five different wavelengths vary with a change of wavelength. The maximum absorption coefficient for tissue samples is 0.265 mm^-1at 980 nm, and the minimum absorption coefficient is 0.0332 mm^-1at 730 nm, and the maximum difference in the absorption coefficients is 698% between 730 and 980 nm, and the minimum difference is 1.61% between 635 and 808 nm. The maximum reduced scattering coefficient for tissue samples is 1.19 mm^-1at 635 nm, and the minimum reduced scattering coefficient is 0.521 mm^-1at 980 nm, and the maximum difference in the reduced scattering coefficients is 128% between 635 and 980 nm, and the minimum difference is 1.15% between 890 and 980 nm. The maximum optical penetration depth for tissue samples is 3.57 mm at 808 nm, and the minimum optical penetration depth is 1.43 mm at 980 nm. The maximum diffusion constant for tissue samples is 0.608 mm at 890 nm, and the minimum diffusion constant is 0.278 mm at 635 nm. The maximum diffuse reflectance is 3.57 mm^-1at 808 nm, and the minimum diffuse reflectance is 1.43 mm^-1at 980 nm. The maximum shift Δx of diffuse reflectance is 1.11 mm^-1at 890 nm, and the minimum shift Δx of diffuse reflectance is 0.507 mm^-1at 635 nm.</p> <p>Conclusion</p> <p>The absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at 635, 730, 808, 890 and 980 nm wavelengths vary with a change of wavelength. There were significant differences in the optical properties for tissue samples at five different wavelengths (<it>P </it>< 0.01).</p

Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

Detection of Prion Protein in Urine-Derived Injectable Fertility Products by a Targeted Proteomic Approach

BACKGROUND: Iatrogenic transmission of human prion disease can occur through medical or surgical procedures, including injection of hormones such as gonadotropins extracted from cadaver pituitaries. Annually, more than 300,000 women in the United States and Canada are prescribed urine-derived gonadotropins for infertility. Although menopausal urine donors are screened for symptomatic neurological disease, incubation of Creutzfeldt-Jakob disease (CJD) is impossible to exclude by non-invasive testing. Risk of carrier status of variant CJD (vCJD), a disease associated with decades-long peripheral incubation, is estimated to be on the order of 100 per million population in the United Kingdom. Studies showing infectious prions in the urine of experimental animals with and without renal disease suggest that prions could be present in asymptomatic urine donors. Several human fertility products are derived from donated urine; recently prion protein has been detected in preparations of human menopausal gonadotropin (hMG). METHODOLOGY/PRINCIPAL FINDINGS: Using a classical proteomic approach, 33 and 34 non-gonadotropin proteins were identified in urinary human chorionic gonadotropin (u-hCG) and highly-purified urinary human menopausal gonadotropin (hMG-HP) products, respectively. Prion protein was identified as a major contaminant in u-hCG preparations for the first time. An advanced prion protein targeted proteomic approach was subsequently used to conduct a survey of gonadotropin products; this approach detected human prion protein peptides in urine-derived injectable fertility products containing hCG, hMG and hMG-HP, but not in recombinant products. CONCLUSIONS/SIGNIFICANCE: The presence of protease-sensitive prion protein in urinary-derived injectable fertility products containing hCG, hMG, and hMG-HP suggests that prions may co-purify in these products. Intramuscular injection is a relatively efficient route of transmission of human prion disease, and young women exposed to prions can be expected to survive an incubation period associated with a minimal inoculum. The risks of urine-derived fertility products could now outweigh their benefits, particularly considering the availability of recombinant products

Dark Matter from Minimal Flavor Violation

We consider theories of flavored dark matter, in which the dark matter particle is part of a multiplet transforming nontrivially under the flavor group of the Standard Model in a manner consistent with the principle of Minimal Flavor Violation (MFV). MFV automatically leads to the stability of the lightest state for a large number of flavor multiplets. If neutral, this particle is an excellent dark matter candidate. Furthermore, MFV implies specific patterns of mass splittings among the flavors of dark matter and governs the structure of the couplings between dark matter and ordinary particles, leading to a rich and predictive cosmology and phenomenology. We present an illustrative phenomenological study of an effective theory of a flavor SU(3)_Q triplet, gauge singlet scalar.Comment: 10 pages, 2 figures; v2: references added, minor changes to collider analysis, conclusions unchange