Identification of SOD1 as the mutated protein in a significant subset of familial amyotrophic lateral sclerosis (FALS) cases has led to the generation of transgenic rodent models of autosomal dominant SOD1 FALS. Mice carrying 23 copies of the human SOD1(G93A) transgene are considered the standard model for FALS and ALS therapeutic studies. To date, there have been at least 50 publications describing therapeutic agents that extend the lifespan of this mouse. However, no therapeutic agent besides riluzole has shown corresponding clinical efficacy. We used computer modeling and statistical analysis of 5429 SOD1(G93A) mice from our efficacy studies to quantify the impact of several critical confounding biological variables that must be appreciated and should be controlled for when designing and interpreting efficacy studies. Having identified the most critical of these biological variables, we subsequently instituted parameters for optimal study design in the SOD1(G93A) mouse model. We retested several compounds reported in major animal studies (minocycline, creatine, celecoxib, sodium phenylbutyrate, ceftriaxone, WHI-P131, thalidomide, and riluzole) using this optimal study design and found no survival benefit in the SOD1(G93A) mouse for any compounds (including riluzole) administered by their previously reported routes and doses. The presence of these uncontrolled confounding variables in the screening system, and the failure of these several drugs to demonstrate efficacy in adequately designed and powered repeat studies, leads us to conclude that the majority of published effects are most likely measurements of noise in the distribution of survival means as opposed to actual drug effect. We recommend a minimum study design for this mouse model to best address and manage this inherent noise and to facilitate more significant and reproducible results among all laboratories employing the SOD1(G93A) mouse.

The mitogen-activated protein (MAP) kinase homologue FUS3 mediates both transcription and Gl arrest in a pheromone-induced signal transduction cascade in Saccharomyces cerevisiae. We report an in vitro kinase assay for FUS3 and its use in identifying candidate substrates. The assay requires catalytically active FUS3 and pheromone induction. STE7, a MAP kinase kinase homologue, is needed for maximal activity. At least seven proteins that specifically associate with FUS3 are phosphorylated in the assay. Many of these substrates are physiologically relevant and are affected by in vivo levels of numerous signal transduction components. One substrate is likely to be the transcription factor STE12. A second is likely to be FAR1, a protein required for Gl arrest. FAR1 was isolated as a multicopy suppressor of a nonarresting fus3 mutant and interacts with FUS3 in a two hybrid system. Consistent with this FAR1 is a good substrate in vitro and generates a FUS3-associated substrate of expected size. These data support a model in which FUS3 mediates transcription and Gi arrest by direct activation of STE12 and FAR1 and phosphorylates many other proteins involved in the response to pheromone.

Somatic mutations in CREBBP occur frequently in B-cell lymphoma. Here, we show that loss of CREBBP facilitates development of germinal center derived lymphomas in mice. In both human and murine lymphomas CREBBP loss of function resulted in focal depletion of enhancer H3K27 acetylation and aberrant transcriptional silencing of genes that regulate B-cell signaling and immune responses including class II MHC. Mechanistically, CREBBP regulated enhancers are counter-regulated by the BCL6 transcriptional repressor in a complex with SMRT and HDAC3, which we find bind extensively to MHC class II loci. HDAC3 loss of function rescued repression of these enhancers and corresponding genes including MHC class II, and more profoundly suppress CREBPP mutant lymphomas in vitro and in vivo. Hence CREBBP loss of function contributes to lymphomagenesis by enabling unopposed suppression of enhancers by BCL6/SMRT/HDAC3 complexes, suggesting HDAC3 targeted therapy as a precision approach for CREBBP mutant lymphomas.

The Schizophrenia Psychiatric Genome-Wide Association Consortium (PGC) highlighted 81 single nucleotide polymorphisms (SNPs) with moderate evidence for association to schizophrenia. After follow up in independent samples, 7 loci attained genome wide significance (GWS), but multi-locus tests suggested some SNPs that did not do so represented true associations. We tested 78 of the 81 SNPs in 2640 individuals with a clinical diagnosis of schizophrenia attending a clozapine clinic (CLOZUK), 2504 cases with a research diagnosis of bipolar disorder, and 2878 controls. In CLOZUK, we obtained significant replication to the PGC-associated allele for no fewer than 37 (47%) of the SNPs, including many prior GWS MHC SNPs as well as 3/6 non-MHC SNPs for which we had data that were reported as GWS by the PGC. After combining the new schizophrenia data with those of the PGC, variants at three loci (ITIH3/4, CACNA1C and SDCCAG8) that had not previously been GWS in schizophrenia attained that level of support. In bipolar disorder, we also obtained significant evidence for association for 21% of the alleles that had been associated with schizophrenia in the PGC. Our study independently confirms association to 3 loci previously reported to be GWS in schizophrenia and identifies the first GWS evidence in schizophrenia for a further 3 loci. Given the number of independent replications and the power of our sample, we estimate 98% (C.I. 78–100%) of the original set of 78 SNPs represent true associations. We also provide strong evidence for overlap in genetic risk between schizophrenia and bipolar disorder.