7T MRI Predicts Amelioration of Neurodegeneration in the Brain after AAV Gene Therapy.

GM1 gangliosidosis (GM1) is a fatal neurodegenerative lysosomal storage disease that occurs most commonly in young children, with no effective treatment available. Long-term follow-up of GM1 cats treated by bilateral thalamic and deep cerebellar nuclei (DCN) injection of adeno-associated virus (AAV)-mediated gene therapy has increased lifespan to 8 years of age, compared with an untreated lifespan of ~8 months. Due to risks associated with cerebellar injection in humans, the lateral ventricle was tested as a replacement route to deliver an AAVrh8 vector expressing feline ß-galactosidase (ß-gal), the defective enzyme in GM1. Treatment via the thalamus and lateral ventricle corrected storage, myelination, astrogliosis, and neuronal morphology in areas where ß-gal was effectively delivered. Oligodendrocyte number increased, but only in areas where myelination was corrected. Reduced AAV and ß-gal distribution were noted in the cerebellum with subsequent increases in storage, demyelination, astrogliosis, and neuronal degeneration. These postmortem findings were correlated with endpoint MRI and magnetic resonance spectroscopy (MRS). Compared with the moderate dose with which most cats were treated, a higher AAV dose produced superior survival, currently 6.5 years. Thus, MRI and MRS can predict therapeutic efficacy of AAV gene therapy and non-invasively monitor cellular events within the GM1 brain.

Antioxidants and Male Fertility: from Molecular Studies to Clinical Evidence.

Spermatozoa are physiologically exposed to reactive oxygen species (ROS) that play a pivotal role on several sperm functions through activation of different intracellular mechanisms involved in physiological functions such as sperm capacitation associated-events. However, ROS overproduction depletes sperm antioxidant system, which leads to a condition of oxidative stress (OS). Subfertile and infertile men are known to present higher amount of ROS in the reproductive tract which causes sperm DNA damage and results in lower fertility and pregnancy rates. Thus, there is a growing number of couples seeking fertility treatment and assisted reproductive technologies (ART) due to OS-related problems in the male partner. Interestingly, although ART can be successfully used, it is also related with an increase in ROS production. This has led to a debate if antioxidants should be proposed as part of a fertility treatment in an attempt to decrease non-physiological elevated levels of ROS. However, the rationale behind oral antioxidants intake and positive effects on male reproduction outcome is only supported by few studies. In addition, it is unclear whether negative effects may arise from oral antioxidants intake. Although there are some contrasting reports, oral consumption of compounds with antioxidant activity appears to improve sperm parameters, such as motility and concentration, and decrease DNA damage, but there is not sufficient evidence that fertility rates and live birth really improve after antioxidants intake. Moreover, it depends on the type of antioxidants, treatment duration, and even the diagnostics of the man's fertility, among other factors. Literature also suggests that the main advantage of antioxidant therapy is to extend sperm preservation to be used during ART. Herein, we discuss ROS production and its relevance in male fertility and antioxidant therapy with focus on molecular mechanisms and clinical evidence.

Pendred syndrome in a large consanguineous Brazilian family caused by a homozygous mutation in the SLC26A4 gene / Síndrome de Pendred causada por mutação em homozigoze no gene SLC26A4 em uma família brasileira consangüínea

Pendred Syndrome (PS) is an autossomal recessive disorder characterized by sensorineural deafness, goiter and iodide organification defect. The hearing loss is associated with inner ear abnormalities, ranging from an isolated enlarged vestibular aqueduct (EVA) to a typical coclear dysplasia. Mutations in the gene that encodes pendrin (SLC26A4), a chloride/iodide transporter, have been shown to be associated with PS. We describe the clinical and molecular characteristics of a large consanguineous family harboring a mutation in the SLC26A4 gene. The proband was a 26-year-old deaf Brazilian woman who presented a bulky multinodular goiter and hypothyroidism since puberty. Five other siblings were deaf: one brother had a similar phenotype, three siblings also had goiters but normal thyroid function tests, and one brother had only a subtle thyroid enlargement. Other 4 siblings had no thyroid or hearing disorder. Parents were first degree cousins and had normal hearing. The mother was healthy, except for subclinical hypothyroidism; the father was deceased. A perchlorate test in the proband showed a discharge of 21 percent of the incorporated iodide 2h after the administration of 1g of KClO4. Audiological examinations showed profound hearing loss in all deaf subjects; CT and MRI of the temporal bones showed EVA in all of them. Genomic DNA was isolated from whole blood, from the 6 affected and 4 unaffected siblings, the mother and control. The coding region of the PDS gene (exons 2-21), including exon/intron boundaries, were amplified by PCR and sequenced. A single base-pair (T) deletion at position 1197 of exon 10 was detected in homozygous state in the 6 deaf siblings. The mother and 2 unaffected siblings were heterozygous for this mutation, which has been described by Everett et al. The 1197delT mutation is predicted to result in a frameshift and a truncated protein. The existence of PS phenocopies and intrafamilial phenotypic variability are...

A syndrome de Pendred (SP) é uma doença autossômica recessiva caracterizada por surdez neurossensorial, bócio e defeito de organificação do iodo. A perda auditiva está associada a anormalidades do ouvido interno, desde a dilatação isolada do aqueduto vestibular (DAV) até uma típica displasia coclear. Mutações no gene que codifica a pendrina (SLC26A4), um transportador de cloreto/iodeto, têm sido associadas à SP. Descrevemos as características clínicas e moleculares de uma grande família consangüínea portadora de uma mutação no gene SLC26A4. O caso-índice era uma paciente do sexo feminino, brasileira, 26 anos, portadora de surdez congênita, que apresentava um volumoso bócio multinodular e hipotireoidismo desde a puberdade. Outros cinco irmãos eram surdos: um irmão tinha fenotipo semelhante, três também tinham bócio, porém com função tiroideana normal e um irmão tinha apenas um discreto aumento da tiróide. Outros quatro irmãos não apresentavam alteração tiroideana ou auditiva. Os pais eram primos de primeiro grau e tinham audição normal. A mãe era saudável, exceto por hipotireoidismo subclínico; o pai era falecido. O teste do perclorato no caso-índice revelou a liberação de 21 por cento do iodo incorporado duas horas após a administração de 1 g de KClO4. Os exames audiológicos mostraram perda auditiva profunda em todos os indivíduos afetados; TC e RMN dos ossos temporais mostraram DAV em todos eles. O DNA genômico foi isolado do sangue total dos seis irmãos afetados e dos quatro não-afetados, da mãe e do controle. A região codificante do gene PDS (éxons 2-21), incluindo as junções éxon/íntron, foram amplificadas por PCR e seqüenciadas. Foi detectada a deleção de uma base (T) na posição 1197 do éxon 10, em homozigoze, nos seis irmãos afetados. A mãe e dois irmãos não-afetados eram heterozigotos para a mutação, que foi descrita inicialmente por Everett e cols. A mutação 1197delT provavelmente resulta em um erro de fase de leitura (frameshift)...

Pendred syndrome in a large consanguineous Brazilian family caused by a homozygous mutation in the SLC26A4 gene.

Pendred Syndrome (PS) is an autossomal recessive disorder characterized by sensorineural deafness, goiter and iodide organification defect. The hearing loss is associated with inner ear abnormalities, ranging from an isolated enlarged vestibular aqueduct (EVA) to a typical coclear dysplasia. Mutations in the gene that encodes pendrin (SLC26A4), a chloride/iodide transporter, have been shown to be associated with PS. We describe the clinical and molecular characteristics of a large consanguineous family harboring a mutation in the SLC26A4 gene. The proband was a 26-year-old deaf Brazilian woman who presented a bulky multinodular goiter and hypothyroidism since puberty. Five other siblings were deaf: one brother had a similar phenotype, three siblings also had goiters but normal thyroid function tests, and one brother had only a subtle thyroid enlargement. Other 4 siblings had no thyroid or hearing disorder. Parents were first degree cousins and had normal hearing. The mother was healthy, except for subclinical hypothyroidism; the father was deceased. A perchlorate test in the proband showed a discharge of 21% of the incorporated iodide 2h after the administration of 1g of KClO4. Audiological examinations showed profound hearing loss in all deaf subjects; CT and MRI of the temporal bones showed EVA in all of them. Genomic DNA was isolated from whole blood, from the 6 affected and 4 unaffected siblings, the mother and control. The coding region of the PDS gene (exons 2-21), including exon/intron boundaries, were amplified by PCR and sequenced. A single base-pair (T) deletion at position 1197 of exon 10 was detected in homozygous state in the 6 deaf siblings. The mother and 2 unaffected siblings were heterozygous for this mutation, which has been described by Everett et al. The 1197delT mutation is predicted to result in a frameshift and a truncated protein. The existence of PS phenocopies and intrafamilial phenotypic variability are well documented. The definite diagnosis requires molecular analysis. Our study illustrates the value and challenges of mutational analysis in selected patients with PS.