New zebrafish models of neurodegeneration

In modern biomedicine, the increasing need to develop experimental models to further our understanding of disease conditions and delineate innovative treatments has found in the zebrafish (Danio rerio) an experimental model, and indeed a valuable asset, to close the gap between in vitro and in vivo assays. Translation of ideas at a faster pace is vital in the field of neurodegeneration, with the attempt to slow or prevent the dramatic impact on the society's welfare being an essential priority. Our research group has pioneered the use of zebrafish to contribute to the quest for faster and improved understanding and treatment of neurodegeneration in concert with, and inspired by, many others who have primed the study of the zebrafish to understand and search for a cure for disorders of the nervous system. Aware of the many advantages this vertebrate model holds, here, we present an update on the recent zebrafish models available to study neurodegeneration with the goal of stimulating further interest and increasing the number of diseases and applications for which they can be exploited. We shall do so by citing and commenting on recent breakthroughs made possible via zebrafish, highlighting their benefits for the testing of therapeutics and dissecting of disease mechanisms

Variants in the non-coding region of the TLR2 gene associated with infectious subphenotypes in pediatric sickle cell anemia

International audienceSickle cell anemia (SCA) is characterized by chronic hemolysis, severe vasoocclusive crises (VOCs), and recurrent often severe infections. A cohort of 95 SCA pediatric patients was the background for genotype-to-phenotype association of the patient's infectious disease phenotype and three non-coding polymorphic regions of the TLR2 gene, the -196 to -174 indel, SNP rs4696480, and a (GT)n short tandem repeat. The infectious subphenotypes included (A) recurrent respiratory infections and (B) severe bacterial infection at least once during the patient's follow-up. The absence of the haplotype [Del]-T-[n ≥ 17] (Hap7) in homozygocity protected against subphenotype (B), in a statistically significant association, resisting correction for multiple testing. For the individual loci, the same association tendencies were observed as in the haplotype, including a deleterious association between the SNP rs4696480 T allele and subphenotype (A), whereas the A/A genotype was protective, and a deleterious effect of the A/T genotype with subphenotype (B), as well as including the protective effect of -196 to -174 insert (Ins) and deleterious effect of the deletion (Del) in homozygocity, against subphenotype (B). Moreover, a reduction in the incidence rate of severe bacterial infection was associated to a rise in the hemolytic score, fetal hemoglobin levels (prior to hydroxyurea treatment), and 3.7-kb alpha-thalassemia. Interestingly, differences between the effects of the two latter covariables favoring a reduction in the incidence rate of subphenotype (B) contrast with a resulting increase in relation to subphenotype (A). These results could have practical implications in health care strategies to lower the morbidity and mortality of SCA patients

Limb-girdle muscular dystrophy: an immunohistochemical diagnostic approach Distrofias musculares de cinturas: uma abordagem diagnóstica imuno-histoquímica

The limb-girdle muscle dystrophy (LGMD) represents a heterogeneous group of muscular diseases with dominant and recessive inheritance, individualized by gene mutation. A group of 56 patients, 32 males and 24 females, with suggestive LGMD diagnosis were submitted to clinical evaluation, serum muscle enzymes, electromyography, muscle biopsy, and the immunoidentification (ID) of sarcoglycans (SG) alpha, beta, gamma and delta, dysferlin and western blot for calpain-3. All the patients had normal ID for dystrophin (rod domain, carboxyl and amine terminal). The alpha-SG was normal in 42 patients, beta-SG in 28, beta-SG in 45, delta-SG in 32, dysferlin in 37 and calpain-3 in 9. There was a reduction in the alpha-SG in 7 patients, beta-SG in 4, gamma-SG in 2, and delta-SG in 8. There was deficiency of alpha-SG in 7 patients, beta-SG in 6, gamma-SG in 9, delta-SG in 5, dysferlin in 8, and calpain-3 in 5. The patients were grouped according the ID as sarcoglycans deficiency 18 cases, dysferlin deficiency 8 cases and calpain-3 deficiency 5 cases. Only the sarcoglycans deficiency group showed calf hypertrophy. The dysferlin deficiency group was more frequent in females and the onset was later than sarcoglycan and calpain-3 deficiency groups. The calpain-3 deficiency group occurred only in males and showed an earlier onset and weaker muscular strength.<br>As distrofias musculares de cinturas (DMC) representam grupo heterogêneo de doenças musculares com heranças autossômicas dominante ou recessivas, caracterizadas geneticamente por mutações gênicas específicas. Cinqüenta e seis pacientes, 32 masculinos e 24 femininos, com diagnóstico sugestivo de DMC, foram submetidos a avaliação clínica, dosagem séricas das enzimas musculares, eletromiografia, biópsia muscular e imunoidentificação (ID) das proteínas sarcoglicanas (SG) alfa, beta, gama e delta, disferlina e calpaína-3. A ID da distrofina (domínio rod e terminais carboxila e amino) era normal em todos os pacientes. Apresentaram ID normal para alfa-SG 42 casos, beta-SG 28, gama,-SG 45, delta-SG 32, disferlina 37 e calpaína-3 9. Foi observada redução de alfa-SG em 7 pacientes, beta-SG em 4, gama-SG em 2 e delta-SG em 8. Houve deficiência de alfa-SG em 7 pacientes, beta-SG em 6, gama-SG 9, delta-SG em 5, disferlina em 8 e calpaína-3 em 5. Os pacientes foram classificados de acordo com a ID em deficiência de SG em 18 casos, disferlina em 8 e calpaína-3 em 5. A hipertrofia de panturrilhas foi observada apenas no grupo com deficiência de SG. O grupo com deficiência de disferlina teve maior número de mulheres acometidas e a idade de início dos sintomas foi mais tardio em relação aos grupos com deficiência de SG e calpaína-3. O grupo com deficiência de calpaína-3 ocorreu apenas em pacientes do sexo masculino, a idade do início dos sintomas foi menor e teve maior fraqueza muscular