Randomized Trial to Evaluate Tandosporine in Geographic Atrophy Secondary to Age-Related Macular Degeneration: the GATE Study.

PURPOSE To determine the safety and efficacy of AL-8309B (tandospirone) in the management of patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD) and obtain standardized data on GA lesion growth progression. DESIGN Prospective, controlled, double-masked, randomized, multicenter phase 3 clinical trial. METHODS Setting: 48 clinical sites. PATIENTS Patients with GA associated with AMD were enrolled. All patients were followed for a minimum of 30 months, and up to 36 months. Intervention Procedures: Patients were randomized (1:1:1) to receive AL-8309B ophthalmic solution 1.0%, 1.75%, or vehicle, administered as a twice-daily topical ocular drop. MAIN OUTCOME MEASURES The primary efficacy endpoint was mean annualized lesion enlargement from baseline as assessed with fundus autofluorescence (FAF) imaging. RESULTS A total of 768 eyes of 768 patients were enrolled and treated with AL-8309B 1.0% (N=250), AL-8309B 1.75% (N=258), or vehicle (N= 260). An increase in mean lesion size was observed in both the AL-8309B and vehicle treatment groups, and growth rates were similar in all treatment groups. Annualized lesion growth rates were 1.73, 1.76 and 1.71 mm(2) for AL-8309B 1.0%, AL-8309B 1.75%, and vehicle, respectively. CONCLUSIONS AL-8309B 1.0% and 1.75% did not affect lesion growth in eyes with GA secondary to AMD. There were no clinically relevant safety issues identified for AL-8309B. The large natural history dataset from this study is a valuable repository for future comparisons.

Central and peripheral defects in motor units of the diaphragm of spinal muscular atrophy mice.

Spinal muscular atrophy (SMA) is characterized by motoneuron loss and muscle weakness. However, the structural and functional deficits that lead to the impairment of the neuromuscular system remain poorly defined. By electron microscopy, we previously found that neuromuscular junctions (NMJs) and muscle fibres of the diaphragm are among the earliest affected structures in the severe mouse SMA model. Because of certain anatomical features, i.e. its thinness and its innervation from the cervical segments of the spinal cord, the diaphragm is particularly suitable to characterize both central and peripheral events. Here we show by immunohistochemistry that, at postnatal day 3, the cervical motoneurons of SMA mice receive less stimulatory synaptic inputs. Moreover, their mitochondria become less elongated which might represent an early stage of degeneration. The NMJs of the diaphragm of SMA mice show a loss of synaptic vesicles and active zones. Moreover, the partly innervated endplates lack S100 positive perisynaptic Schwann cells (PSCs). We also demonstrate the feasibility of comparing the proteomic composition between diaphragm regions enriched and poor in NMJs. By this approach we have identified two proteins that are significantly upregulated only in the NMJ-specific regions of SMA mice. These are apoptosis inducing factor 1 (AIFM1), a mitochondrial flavoprotein that initiates apoptosis in a caspase-independent pathway, and four and a half Lim domain protein 1 (FHL1), a regulator of skeletal muscle mass that has been implicated in several myopathies.

Natural History of Geographic Atrophy Progression Secondary to Age-Related Macular Degeneration (Geographic Atrophy Progression Study).

PURPOSE The Geographic Atrophy Progression (GAP) study was designed to assess the rate of geographic atrophy (GA) progression and to identify prognostic factors by measuring the enlargement of the atrophic lesions using fundus autofluorescence (FAF) and color fundus photography (CFP). DESIGN Prospective, multicenter, noninterventional natural history study. PARTICIPANTS A total of 603 participants were enrolled in the study; 413 of those had gradable lesion data from FAF or CFP, and 321 had gradable lesion data from both FAF and CFP. METHODS Atrophic lesion areas were measured by FAF and CFP to assess lesion progression over time. Lesion size assessments and best-corrected visual acuity (BCVA) were conducted at screening/baseline (day 0) and at 3 follow-up visits: month 6, month 12, and month 18 (or early exit). MAIN OUTCOME MEASURES The GA lesion progression rate in disease subgroups and mean change from baseline visual acuity. RESULTS Mean (standard error) lesion size changes from baseline, determined by FAF and CFP, respectively, were 0.88 (0.1) and 0.78 (0.1) mm(2) at 6 months, 1.85 (0.1) and 1.57 (0.1) mm(2) at 12 months, and 3.14 (0.4) and 3.17 (0.5) mm(2) at 18 months. The mean change in lesion size from baseline to month 12 was significantly greater in participants who had eyes with multifocal atrophic spots compared with those with unifocal spots (P < 0.001) and those with extrafoveal lesions compared with those with foveal lesions (P = 0.001). The mean (standard deviation) decrease in visual acuity was 6.2 ± 15.6 letters for patients with image data available. Atrophic lesions with a diffuse (mean 0.95 mm(2)) or banded (mean 1.01 mm(2)) FAF pattern grew more rapidly by month 6 compared with those with the "none" (mean, 0.13 mm(2)) and focal (mean, 0.36 mm(2)) FAF patterns. CONCLUSIONS Although differences were observed in mean lesion size measurements using FAF imaging compared with CFP, the measurements were highly correlated with one another. Significant differences were found in lesion progression rates in participants stratified by hyperfluorescence pattern subtype. This large GA natural history study provides a strong foundation for future clinical trials.

STUDIES INTO THE MOLECULAR MECHANISMS REGULATING MUSCULAR ATROPHY RESULTING FROM HINDLIMB IMMOBILIZATION IN THE RAT (PROTEIN, SYNTHESIS, RNA)

The purpose of the work performed in this dissertation was to examine some of the possible regulatory mechanisms involved in the initiation of muscular atrophy during periods of decreased muscle utilization resulting from hindlimb immobilization in the rat. A 37% decrease in the rate of total muscle protein synthesis which has been observed to occur in the first 6 h of immobilization contributes significantly to the observed loss of protein during immobilization.^ The rates of cytochrome c and actin synthesis were determined in adult rat red vastus lateralis and gastrocnemius muscles, respectively, by the constant infusion and incorporation of ('3)H-tyrosine into protein. The fractional synthesis rates of both actin and cytochrome c were significantly decreased (P < 0.05) in the 6th h of hindlimb immobilization.^ RHA was extracted from adult rat gastrocnemius muscle by modification of the phenol: chloroform: SDS extraction procedures commonly used for preparation of RNA for hybridization analysis from other mammalian tissues. RNA content of rat gastrocnemius muscle, as determined by this method of extraction and its subsequent quantification by UV absorbance and orcinol assay, was significantly greater than the RNA content previously determined for adult rat gastrocnemius by other commonly employed methods.^ RNA extracted by this method from gastrocnemius muscles of control and 6h immobilized rats was subjected to "dot blot" hybridization to ('32)P-labelled probe from plasmid p749, containing a cDNA sequence complementary to (alpha)-actin mRNA and from rat skeletal muscle. (alpha)-Actin specific mRNA content as estimated by this procedure is not significantly decreased in rat gastrocnemius following 6h or hindlimb immobilization. However, (alpha)-actin specific mRNA content is significantly decreased (P < 0.05) in adult rat gastrocnemius (alpha)-actin specific mRNA is not decreased in adult rat gastrocnemius muscle following 6h of immobilization, a time when actin synthesis is significantly decreased, it is concluded that a change in (alpha)-actin specific mRNA content is not the initiating event responsible for the early decrease in actin synthesis observed in the 6th h of immobilization. ^

Rates of ubiquitin conjugation increase when muscles atrophy, largely through activation of the N-end rule pathway

The rapid loss of muscle mass that accompanies many disease states, such as cancer or sepsis, is primarily a result of increased protein breakdown in muscle, and several observations have suggested an activation of the ubiquitin–proteasome system. Accordingly, in extracts of atrophying muscles from tumor-bearing or septic rats, rates of 125I-ubiquitin conjugation to endogenous proteins were found to be higher than in control extracts. On the other hand, in extracts of muscles from hypothyroid rats, where overall proteolysis is reduced below normal, the conjugation of 125I-ubiquitin to soluble proteins decreased by 50%, and treatment with triiodothyronine (T3) restored ubiquitination to control levels. Surprisingly, the N-end rule pathway, which selectively degrades proteins with basic or large hydrophobic N-terminal residues, was found to be responsible for most of these changes in ubiquitin conjugation. Competitive inhibitors of this pathway that specifically block the ubiquitin ligase, E3α, suppressed most of the increased ubiquitin conjugation in the muscle extracts from tumor-bearing and septic rats. These inhibitors also suppressed ubiquitination in normal extracts toward levels in hypothyroid extracts, which showed little E3α-dependent ubiquitination. Thus, the inhibitors eliminated most of the differences in ubiquitination under these different pathological conditions. Moreover, 125I-lysozyme, a model N-end rule substrate, was ubiquitinated more rapidly in extracts from tumor-bearing and septic rats, and more slowly in those from hypothyroid rats, than in controls. Thus, the rate of ubiquitin conjugation increases in atrophying muscles, and these hormone- and cytokine-dependent responses are in large part due to activation of the N-end rule pathway.

Histopathological Defects in Intestine in Severe Spinal Muscular Atrophy Mice Are Improved by Systemic Antisense Oligonucleotide Treatment

Funding: This study is supported by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London (FM and HZ), the Medical Research Council grant (grant reference MR/L013142/1, FM), SMA-Europe grant (FM and HZ) and Great Ormond Street Hospital Children’s Charity grants (FM and JM). JEM is supported by Great Ormond Street Hospital Children’s Charity. PS is supported by Bill Marshall Fellowship and The CP Charitable Trust at Great Ormond Street Hospital and UCL. SHP is supported by SMA Trust and Euan MacDonald Centre for Motor Neurone Disease Research.

Inactivation of the survival motor neuron gene, a candidate gene for human spinal muscular atrophy, leads to massive cell death in early mouse embryos

Proximal spinal muscular atrophy is an autosomal recessive human disease of spinal motor neurons leading to muscular weakness with onset predominantly in infancy and childhood. With an estimated heterozygote frequency of 1/40 it is the most common monogenic disorder lethal to infants; milder forms represent the second most common pediatric neuromuscular disorder. Two candidate genes—survival motor neuron (SMN) and neuronal apoptosis inhibitory protein have been identified on chromosome 5q13 by positional cloning. However, the functional impact of these genes and the mechanism leading to a degeneration of motor neurons remain to be defined. To analyze the role of the SMN gene product in vivo we generated SMN-deficient mice. In contrast to the human genome, which contains two copies, the mouse genome contains only one SMN gene. Mice with homozygous SMN disruption display massive cell death during early embryonic development, indicating that the SMN gene product is necessary for cellular survival and function.

Acetylcholine receptor ɛ-subunit deletion causes muscle weakness and atrophy in juvenile and adult mice

In mammalian muscle a postnatal switch in functional properties of neuromuscular transmission occurs when miniature end plate currents become shorter and the conductance and Ca2+ permeability of end plate channels increases. These changes are due to replacement during early neonatal development of the γ-subunit of the fetal acetylcholine receptor (AChR) by the ɛ-subunit. The long-term functional consequences of this switch for neuromuscular transmission and motor behavior of the animal remained elusive. We report that deletion of the ɛ-subunit gene caused in homozygous mutant mice the persistence of γ-subunit gene expression in juvenile and adult animals. Neuromuscular transmission in these animals is based on fetal type AChRs present in the end plate at reduced density. Impaired neuromuscular transmission, progressive muscle weakness, and atrophy caused premature death 2 to 3 months after birth. The results demonstrate that postnatal incorporation into the end plate of ɛ-subunit containing AChRs is essential for normal development of skeletal muscle.

A single nucleotide in the SMN gene regulates splicing and is responsible for spinal muscular atrophy

SMN1 and SMN2 (survival motor neuron) encode identical proteins. A critical question is why only the homozygous loss of SMN1, and not SMN2, results in spinal muscular atrophy (SMA). Analysis of transcripts from SMN1/SMN2 hybrid genes and a new SMN1 mutation showed a direct relationship between presence of disease and exon 7 skipping. We have reported previously that the exon-skipped product SMNΔ7 is partially defective for self-association and SMN self-oligomerization correlated with clinical severity. To evaluate systematically which of the five nucleotides that differ between SMN1 and SMN2 effect alternative splicing of exon 7, a series of SMN minigenes was engineered and transfected into cultured cells, and their transcripts were characterized. Of these nucleotide differences, the exon 7 C-to-T transition at codon 280, a translationally silent variance, was necessary and sufficient to dictate exon 7 alternative splicing. Thus, the failure of SMN2 to fully compensate for SMN1 and protect from SMA is due to a nucleotide exchange (C/T) that attenuates activity of an exonic enhancer. These findings demonstrate the molecular genetic basis for the nature and pathogenesis of SMA and illustrate a novel disease mechanism. Because individuals with SMA retain the SMN2 allele, therapy targeted at preventing exon 7 skipping could modify clinical outcome.

Hippocampal atrophy in recurrent major depression.

Hippocampal volumes of subjects with a history of major depressive episodes but currently in remission and with no known medical comorbidity were compared to matched normal controls by using volumetric magnetic resonance images. Subjects with a history of major depression had significantly smaller left and right hippocampal volumes with no differences in total cerebral volumes. The degree of hippocampal volume reduction correlated with total duration of major depression. In addition, large (diameter > or = 4.5 mm)-hippocampal low signal foci (LSF) were found within the hippocampus, and their number also correlated with the total number of days depressed. These results suggest that depression is associated with hippocampal atrophy, perhaps due to a progressive process mediated by glucocorticoid neurotoxicity.

Expressed cadherin pseudogenes are localized to the critical region of the spinal muscular atrophy gene.

Low-copy repeats have been associated with genomic rearrangements and have been implicated in the generation of mutations in several diseases. Here we characterize a subset of low-copy repeats in the spinal muscular atrophy (SMA) region in human chromosome 5q13. We show that this repeated sequence, named c41-cad, is a highly expressed pseudogene derived from an intact neuronal cadherin gene, Br-cadherin, situated on 5p13-14. Br-cadherin is expressed specifically in the brain, whereas the c41-cad transcripts are 10-15 times more abundant and are present in all tissues examined. We speculate that the c41-cad repeats, separately or in concert with other repeats in the SMA region, are involved in the pathogenesis of SMA by promoting rearrangements and deletions.

Diferenciación sexual del lenguado de California Paralichthys californicus y control de la proporción sexual mediante la utilización de la hormona 17β-estradiol

El lenguado de California Paralichthys californicus es una especie con alto valor comercial debido a su gran tamaño y calidad de su carne. Esta especie presenta dimorfismo sexual en el crecimiento donde las hembras crecen más rápido que los machos, por lo tanto el cultivo monosexual de hembras resulta favorable para la producción. En el presente estudio se registró el proceso de diferenciación sexual mediante cortes histológicos de las larvas y gónadas del lenguado de California asimismo se probó el efecto de diferentes concentraciones de 17β-estradiol (E2) (2.5, 5 y 10 mg/kg) a través de la dieta para incrementar la proporción de hembras en el cultivo. A los 25 días después de la eclosión (DDE) se observó el primordio gonadal en ejemplares con una longitud total promedio de 6.96 ± 0.92 mm, hasta el día 75 DDE (37.58 ± 6.58 mm) se observó una gónada indiferenciada evidenciada por la presencia de células germinales primordiales. La primera evidencia de diferenciación se registró a los 115 DDE (55.93 ± 14.67 mm) donde se observó la cavidad ovárica y posteriormente a los 180 DDE (115.70 ± 17.02 mm) se evidencian ovarios con ovocitos en crecimiento y testículos con espermátidas. Por lo tanto, el periodo lábil para la diferenciación sexual se encuentra entre los días 75 y 115 después de la eclosión. Por otro lado, el suministro de E2 a través de la dieta a concentraciones de 2.5, 5 y 10 mg/kg incrementó el porcentaje de hembras de 26.67% (control, no adición de E2) a un 100% en todos los tratamientos. Se encontraron diferencias en la proporción de los tipos celulares (ovogonias, ovocitos primarios en fase I y II) entre el control y los tratamientos mientras que no se registraron alteraciones histológicas como atrofia gonadal en ninguno de los casos.

Macular atrophy in patients with long-term anti-VEGF treatment for neovascular age-related macular degeneration.

PURPOSE To identify the prevalence and progression of macular atrophy (MA) in neovascular age-related macular degeneration (AMD) patients under long-term anti-vascular endothelial growth factor (VEGF) therapy and to determine risk factors. METHOD This retrospective study included patients with neovascular AMD and ≥30 anti-VEGF injections. Macular atrophy (MA) was measured using near infrared and spectral-domain optical coherence tomography (SD-OCT). Yearly growth rate was estimated using square-root transformation to adjust for baseline area and allow for linearization of growth rate. Multiple regression with Akaike information criterion (AIC) as model selection criterion was used to estimate the influence of various parameters on MA area. RESULTS Forty-nine eyes (47 patients, mean age 77 ± 14) were included with a mean of 48 ± 13 intravitreal anti-VEGF injections (ranibizumab:37 ± 11, aflibercept:11 ± 6, mean number of injections/year 8 ± 2.1) over a mean treatment period of 6.2 ± 1.3 years (range 4-8.5). Mean best-corrected visual acuity improved from 57 ± 17 letters at baseline (= treatment start) to 60 ± 16 letters at last follow-up. The MA prevalence within and outside the choroidal neovascularization (CNV) border at initial measurement was 45% and increased to 74%. Mean MA area increased from 1.8 ± 2.7 mm(2) within and 0.5 ± 0.98 mm(2) outside the CNV boundary to 2.7 ± 3.4 mm(2) and 1.7 ± 1.8 mm(2) , respectively. Multivariate regression determined posterior vitreous detachment (PVD) and presence/development of intraretinal cysts (IRCs) as significant factors for total MA size (R(2) = 0.16, p = 0.02). Macular atrophy (MA) area outside the CNV border was best explained by the presence of reticular pseudodrusen (RPD) and IRC (R(2) = 0.24, p = 0.02). CONCLUSION A majority of patients show MA after long-term anti-VEGF treatment. Reticular pseudodrusen (RPD), IRC and PVD but not number of injections or treatment duration seem to be associated with the MA size.

Mapping of autosomal recessive chronic distal spinal muscular atrophy to chromosome 11q13

Distal spinal muscular atrophy is a heterogeneous group of neuromuscular disorders caused by progressive anterior born cell degeneration and characterized by progressive motor weakness and muscular atrophy, predominantly in the distal parts of the limbs. Here we report on chronic autosomal recessive distal spinal muscular atrophy in a large, inbred family with onset at various ages. Because this condition had some of the same clinical features as spinal muscular atrophy with respiratory distress, we tested the disease gene for linkage to chromosome 11q and mapped the disease locus to chromosome 11q13 in the genetic interval that included the spinal muscular atrophy with respiratory distress gene (D11S1889-D11S1321, Z(max) = 4.59 at theta = 0 at locus D11S4136). The sequencing of IGHMBP2, the human homologue of the mouse neuromuscular degeneration gene (nmd) that accounts for spinal muscular atrophy with respiratory distress, failed to detect any mutation in our chronic distal spinal muscular atrophy patients, suggesting that spinal muscular atrophy with respiratory distress and chronic distal spinal muscular atrophy are caused by distinct genes located in the so-me chromosomal region. In addition, the high intrafamilial variability in age at onset raises the question of whether nonallelic modifying genes could be involved in chronic distal spinal muscular atrophy.

Comparative proteomic analysis to study molecular events during gonad development in mice

Sex determination represents a critical bifurcation in the road of embryonic development. It is based on a finely regulated network of gene activity, as well as protein-protein interactions and activation or silencing of signaling pathways. Despite the identification of a number of critical genes, many aspects of the molecular cascade that drives the differentiation of the embryonic gonad into either a testis or an ovary remain poorly understood. To identify new proteins involved in this cascade, we employed two-dimensional gel electrophoresis and mass spectrometry to compare the protein expression profiles of fetal mouse testes and ovaries. Three proteins, hnRPA1, TRA1, and HSC71, were found to be expressed in a male-specific manner and this expression was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization. Moreover, HSC71 was found to be hyperphosphorylated in male compared to female gonads, emphasizing the advantage of the proteomic approach in allowing the detection of posttranslational modifications.