POS0222 POLYARTICULAR ARTHRITIS AND ADULT-ONSET OSTEOLYSIS CAUSED BY MUTATIONS IN THE ASAH1 GENE: FARBER DISEASE CLINICAL PRESENTATIONS IN THE CONTEXT OF A FIRST-EVER NATURAL HISTORY STUDY

Background

Farber disease is frequently misdiagnosed as polyarticular juvenile idiopathic arthritis or seronegative rheumatoid arthritis which leads to a delay in diagnosis for many patients. Farber disease is an ultra-rare lysosomal storage disease caused by mutations in the ASAH1 gene. The resulting deficiency of the acid ceramidase enzyme leads to accumulation of the pro-inflammatory and pro-apoptotic sphingolipid ceramide. Accumulation of ceramide throughout the body leads to the symptoms of Farber disease. Cardinal symptoms include joint disease (polyarticular arthritis and contractures), subcutaneous nodules, and a hoarse or weak voice due to laryngeal nodules. The phenotypic spectrum of Farber disease ranges from rapidly progressive disease causing death in infancy to moderate or slowly progressive disease with survival into late adulthood. Symptoms may vary in severity across patients and phenotypes.

Objectives

To further define the symptoms of Farber disease, including joint disease, subcutaneous nodules, dysphonia, and osteolysis, which can lead to referral to rheumatology or related specialties. To understand the clinical presentation and broad phenotypic spectrum of this rare disease to aid in clinical diagnosis and reduce diagnostic delay.

Methods

The Observational and Cross-Sectional Cohort Study of the Natural History and Phenotypic Spectrum of Farber Disease (NCT03233841) was the first systematic clinical study of the natural history of Farber disease. The study collected retrospective and prospective data on living and deceased patients, including demographics, clinical presentation, phenotype, diagnostic history, and patient reported outcomes.

Results

45 patients with Farber disease (27 living, 18 deceased) who had or had not undergone hematopoietic stem cell transplant (HSCT) were enrolled from 16 centers in 9 countries. A cohort of 24 living non-HSCT patients were followed prospectively. The patients represented the broad phenotypic spectrum of Farber disease, from rapidly progressive (severe) to slowly progressive (attenuated). In patients whose data was available for analysis, the average age of patients at enrollment was 7.2 years (range 1 to 28 years). The average age of onset of joint disease (arthritis and/or contractures) was 15 months (range 3 months to 7 years), of subcutaneous nodules was 13 months (range 3 months to 5 years), and of dysphonia was 13 months (range birth to 8 years). The average time from onset of symptoms to Farber disease diagnosis was 2 years (range <1 to 12 years). At baseline, the mean number of joints affected with active arthritis was 11.3 (range 0-36) and the mean number affected with contractures was 18 (range 0-38). 12.5% of patients were reported to have a bone disorder such as osteoporosis or osteolysis. The Child Health Assessment Questionnaire Disability Index (CHAQ) ranging from 0 (no impairment) to 3 (unable to do) was high, with mean scores of 2.62-3.00 across visits.

Conclusion

Data from the Farber disease natural history study further defined the cardinal symptoms, phenotypic spectrum, and high disease-related burden in patients with Farber disease. The large number of joints affected with arthritis or contractures reflects that patients with Farber disease are often referred to rheumatology and can be misdiagnosed with polyarticular juvenile idiopathic arthritis or seronegative rheumatoid arthritis. Demographic information and numbers of patients enrolled indicate that Farber disease is likely not as rare as previously thought. ASAH1 genetic testing for adult and pediatric patients referred to the rheumatology clinic with symptoms including polyarticular arthritis, subcutaneous nodules, dysphonia, or osteolysis, may shorten the time to diagnosis in patients with Farber disease.

Disclosure of Interests

Lothar Seefried Speakers bureau: Aceragen, Amgen, Alexion, Biomarin, Chiesi, KyowaKirin, Novartis, Theramex, and UCB, Consultant of: Amgen, Alexion, Biomarin, Chiesi, KyowaKirin, Novartis, Theramex, and UCB, Grant/research support from: Alexion, KyowaKirin and Novartis, Kathleen Crosby Employee of: Aceragen, Alexander Solyom Employee of: Aceragen

Tissue-specific activation of gene expression by the Synergistic Activation Mediator (SAM) CRISPRa system in mice

CRISPR-based transcriptional activation is a powerful tool for functional gene interrogation; however, delivery difficulties have limited its applications in vivo. Here, we created a mouse model expressing all components of the CRISPR-Cas9 guide RNA-directed Synergistic Activation Mediator (SAM) from a single transcript that is capable of activating target genes in a tissue-specific manner. We optimized Lipid Nanoparticles and Adeno-Associated Virus guide RNA delivery approaches to achieve expression modulation of one or more genes in vivo. We utilized the SAM mouse model to generate a hypercholesteremia disease state that we could bidirectionally modulate with various guide RNAs. Additionally, we applied SAM to optimize gene expression in a humanized Transthyretin mouse model to recapitulate human expression levels. These results demonstrate that the SAM gene activation platform can facilitate in vivo research and drug discovery.

Changes in proteome solubility indicate widespread proteostatic disruption in mouse models of neurodegenerative disease

The deposition of pathologic misfolded proteins in neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, frontotemporal dementia and amyotrophic lateral sclerosis is hypothesized to burden protein homeostatic (proteostatic) machinery, potentially leading to insufficient capacity to maintain the proteome. This hypothesis has been supported by previous work in our laboratory, as evidenced by the perturbation of cytosolic protein solubility in response to amyloid plaques in a mouse model of Alzheimer's amyloidosis. In the current study, we demonstrate changes in proteome solubility are a common pathology to mouse models of neurodegenerative disease. Pathological accumulations of misfolded tau, α-synuclein and mutant superoxide dismutase 1 in CNS tissues of transgenic mice were associated with changes in the solubility of hundreds of CNS proteins in each model. We observed that changes in proteome solubility were progressive and, using the rTg4510 model of inducible tau pathology, demonstrated that these changes were dependent upon sustained expression of the primary pathologic protein. In all of the models examined, changes in proteome solubility were robust, easily detected, and provided a sensitive indicator of proteostatic disruption. Interestingly, a subset of the proteins that display a shift towards insolubility were common between these different models, suggesting that a specific subset of the proteome is vulnerable to proteostatic disruption. Overall, our data suggest that neurodegenerative proteinopathies modeled in mice impose a burden on the proteostatic network that diminishes the ability of neural cells to prevent aberrant conformational changes that alter the solubility of hundreds of abundant cellular proteins.

Loss of charge mutations in solvent exposed Lys residues of superoxide dismutase 1 do not induce inclusion formation in cultured cell models

Mutations in superoxide dismutase 1 (SOD1) associated with familial amyotrophic lateral sclerosis (fALS) induce the protein to misfold and aggregate. Missense mutations at more than 80 different amino acid positions have been associated with disease. How these mutations heighten the propensity of SOD1 to misfold and aggregate is unclear. With so many mutations, it is possible that more than one mechanism of aggregation may be involved. Of many possible mechanisms to explain heightened aggregation, one that has been suggested is that mutations that eliminate charged amino acids could diminish repulsive forces that would inhibit aberrant protein:protein interactions. Mutations at twenty-one charged residues in SOD1 have been associated with fALS, but of the 11 Lys residues in the protein, only 1 has been identified as mutated in ALS patients. Here, we examined whether loss of positively charged surface Lys residues in SOD1 would induce misfolding and formation of intracellular inclusions. We mutated four different Lys residues (K30, K36, K75, K91) in SOD1 that are not particularly well conserved, and expressed these variants as fusion proteins with yellow fluorescent protein (YFP) to assess inclusion formation. We also assessed whether these mutations induced binding to a conformation-restricted SOD1 antibody, designated C4F6, which recognizes non-natively folded protein. Although we observed some mutations to cause enhanced C4F6 binding, we did not observe that mutations that reduce charge at these positions caused the protein to form intracellular inclusions. Our findings may have implications for the low frequency of mutations at Lys residues SOD1 in ALS patients.

Heterogeneity of Matrin 3 in the developing and aging murine central nervous system

Mutations in the MATR3 gene encoding the nucleotide binding protein Matrin 3 have recently been identified as causing a subset of familial amyotrophic lateral sclerosis (fALS) and more rarely causing distal myopathy. Translating the identification of MATR3 mutations into an understanding of disease pathogenesis and the creation of mouse models requires a complete understanding of normal Matrin 3 levels and distribution in vivo. Consequently, we examined the levels of murine Matrin 3 in body tissues and regions of the central nervous system (CNS). We observed a significant degree of variability in Matrin 3 protein levels among different tissues of adult animals, with the highest levels found in reproductive organs and the lowest in muscle. Within the adult CNS, Matrin 3 levels were lowest in spinal cord. Further, we found that Matrin 3 declines significantly in CNS through early development and young adulthood before stabilizing. As previously reported, antibodies to Matrin 3 primarily stain nuclei, but the intensity of staining was not uniform in all nuclei. The low levels of Matrin 3 in spinal cord and muscle could mean that that these tissues are particularly vulnerable to alterations in Matrin 3 function. Our study is the first to characterize endogenous Matrin 3 in rodents across the lifespan, providing the groundwork for deciphering disease mechanisms and developing mouse models of MATR3-linked ALS. J. Comp. Neurol. 524:2740-2752, 2016. © 2016 Wiley Periodicals, Inc.

An analysis of interactions between fluorescently-tagged mutant and wild-type SOD1 in intracellular inclusions

BACKGROUND

By mechanisms yet to be discerned, the co-expression of high levels of wild-type human superoxide dismutase 1 (hSOD1) with variants of hSOD1 encoding mutations linked familial amyotrophic lateral sclerosis (fALS) hastens the onset of motor neuron degeneration in transgenic mice. Although it is known that spinal cords of paralyzed mice accumulate detergent insoluble forms of WT hSOD1 along with mutant hSOD1, it has been difficult to determine whether there is co-deposition of the proteins in inclusion structures.

METHODOLOGY/PRINCIPAL FINDINGS

In the present study, we use cell culture models of mutant SOD1 aggregation, focusing on the A4V, G37R, and G85R variants, to examine interactions between WT-hSOD1 and misfolded mutant SOD1. In these studies, we fuse WT and mutant proteins to either yellow or red fluorescent protein so that the two proteins can be distinguished within inclusions structures.

CONCLUSIONS/SIGNIFICANCE

Although the interpretation of the data is not entirely straightforward because we have strong evidence that the nature of the fused fluorophores affects the organization of the inclusions that form, our data are most consistent with the idea that normal dimeric WT-hSOD1 does not readily interact with misfolded forms of mutant hSOD1. We also demonstrate the monomerization of WT-hSOD1 by experimental mutation does induce the protein to aggregate, although such monomerization may enable interactions with misfolded mutant SOD1. Our data suggest that WT-hSOD1 is not prone to become intimately associated with misfolded mutant hSOD1 within intracellular inclusions that can be generated in cultured cells.

Features of wild-type human SOD1 limit interactions with misfolded aggregates of mouse G86R Sod1

Mutations in the gene encoding superoxide dismutase 1 (SOD1) account for about 20% of the cases of familial amyotrophic lateral sclerosis (fALS). It is well established that mutations in SOD1, associated with fALS, heighten the propensity of the protein to misfold and aggregate. Although aggregation appears to be a factor in the toxicity of mutant SOD1s, the precise nature of this toxicity has not been elucidated. A number of other studies have now firmly established that raising the levels of wild-type (WT) human SOD1 (hSOD1) proteins can in some manner augment the toxicity of mutant hSOD1 proteins. However, a recent study demonstrated that raising the levels of WT-hSOD1 did not affect disease in mice that harbor a mouse Sod1 gene (mSod1) encoding a well characterized fALS mutation (G86R). In the present study, we sought a potential explanation for the differing effects with WT-hSOD1 on the toxicity of mutant hSOD1 versus mutant mSod1. In the cell culture models used here, we observe poor interactions between WT-hSOD1 and misfolded G86R-mSod1, possibly explaining why over-expression of WT-hSOD1 does not synergize with mutant mSod1 to accelerate the course of the disease in mice.

Capsid serotype and timing of injection determines AAV transduction in the neonatal mice brain

Adeno-associated virus (AAV) mediated gene expression is a powerful tool for gene therapy and preclinical studies. A comprehensive analysis of CNS cell type tropism, expression levels and biodistribution of different capsid serotypes has not yet been undertaken in neonatal rodents. Our previous studies show that intracerebroventricular injection with AAV2/1 on neonatal day P0 results in widespread CNS expression but the biodistribution is limited if injected beyond neonatal day P1. To extend these observations we explored the effect of timing of injection on tropism and biodistribution of six commonly used pseudotyped AAVs delivered in the cerebral ventricles of neonatal mice. We demonstrate that AAV2/8 and 2/9 resulted in the most widespread biodistribution in the brain. Most serotypes showed varying biodistribution depending on the day of injection. Injection on neonatal day P0 resulted in mostly neuronal transduction, whereas administration in later periods of development (24–84 hours postnatal) resulted in more non-neuronal transduction. AAV2/5 showed widespread transduction of astrocytes irrespective of the time of injection. None of the serotypes tested showed any microglial transduction. This study demonstrates that both capsid serotype and timing of injection influence the regional and cell-type distribution of AAV in neonatal rodents, and emphasizes the utility of pseudotyped AAV vectors for translational gene therapy paradigms.

Renal tumour suppressor function of the Birt-Hogg-Dubé syndrome gene product folliculin

BACKGROUND

Renal cell carcinoma (RCC) comprises five major molecular and histological subtypes. The Birt-Hogg-Dubé (BHD) syndrome is a hereditary human cancer syndrome that predisposes affected individuals to develop renal carcinoma of nearly all subtypes, in addition to benign fibrofolliculomas, and pulmonary and renal cysts. BHD is caused by loss-of-function mutations in the folliculin (FLCN) protein. The molecular function of FLCN is still largely unknown; opposite and conflicting evidence of the role of FLCN in mammalian target of rapamycin signalling/phosphorylated ribosomal protein S6 (p-S6) activation had recently been reported.

RESULTS AND METHODS

Here, the expression pattern of murine Flcn was described, and it was observed that homozygous disruption of Flcn results in embryonic lethality early during development. Importantly, heterozygous animals manifest early preneoplastic kidney lesions, devoid of Flcn expression, that progress towards malignancy, including cystopapillary adenomas. A bona fide tumour suppressor activity of FLCN was confirmed by nude mouse xenograft assays of two human RCC cell lines with either diminished or re-expressed FLCN. It was observed that loss of FLCN expression leads to context-dependent effects on S6 activation. Indeed, solid tumours and normal kidneys show decreased p-S6 upon diminished FLCN expression. Conversely, p-S6 is found to be elevated or absent in FLCN-negative renal cysts.

CONCLUSION

In accordance with clinical data showing distinct renal malignancies arising in BHD patients, in this study FLCN is shown as a general tumour suppressor in the kidney.

The efficacy of Herceptin therapies is influenced by the expression of other erbB receptors, their ligands and the activation of downstream signalling proteins

ErbB2 and EGFR are attractive oncology therapeutic targets as their overexpression in tumors predicts a poorer clinical outcome in a variety of epithelial malignancies. However, clinical results with therapeutic compounds targeting these receptors have been mixed. Therefore, there is a need for improved predictive biomarkers for these targeted therapeutics. In this study we analysed tissue microarrays of patients treated with combination chemotherapy and Herceptin for expression or phosphorylation of signalling proteins associated with erbB receptors to identify protein biomarkers that are predictive of breast cancer patient response. A comparison of expression or phosphorylation of these markers with patient outcome revealed that response to Herceptin depended not only on expression levels of erbB2 but also on expression of EGFR, expression of erbB ligands, expression of other receptors and phosphorylation of downstream proteins. Elucidating the biological effects of EGFR/erbB2 targeted therapeutics will enable patient tumor profiling to identify likely responders and the determination of biologically effective doses that allows chronic administration of these agents in order to maximise efficacy.

The Evolutionary History and Diversity of Australian Mammals

Palaeodiversity and relationships of all groups of Australian mammals are reviewed. The fossil record spanning this time is of variable quality. &apos;Dark Ages&apos; about which nothing is known in terms of Australian mammal evolution include the late Triassic to late Jurassic, late Cretaceous to late Paleocene and middle Eocene to middle Oligocene. Very little is known about the early Cretaceous and late Miocene. The late Oligocene to middle Miocene record documents the highest levels of biodiversity known for the continent, comparable to that which characterises the lowland rainforests of Borneo and Brazil. Order Monotremata spans at least the last 110 million years and includes four families. The enigmatic Ausktribosphenos from 115 million-year-old sediments in Victoria may represent an archaic monotreme, specialised peramurid or previously undocumented order of mammals but is unlikely to represent a placental as suggested in the initial description. Order Microbiotheria is represented in the early Eocene (~55 mya) by two genera similar in morphology to early Eocene taxa from Argentina. Order Peramelemorphia spans the early Eocene to Holocene and includes at least five families. Order Dasyuromorphia spans at least the late Oligocene to Holocene and includes at least three families. Other dasyuromorphian-like marsupials are indeterminate in terms of family-level affinities. Order Notoryctemorphia spans the early Miocene to Holocene with one family. Order Yalkaparidontia spans the late Oligocene to middle Miocene with one genus. Order Diprotodontia spans the late Oligocene to Holocene, represented throughout by three major groups: Phalangerida (eight families), Vombatomorphia (seven families) and Macropodoidea (at least three families). A possible placental condylarth (Tingamarra) has been recorded from the early Eocene. An archaeonycteridid bat (Australonycteris) is known from the early Eocene. Among bats, the late Oligocene to middle Miocene is dominated by rhinolophoids, many of which have European, Asian and African affinities. Mystacinids, megadermatids, hipposiderids and molossids are well-represented in the Oligocene to Miocene deposits. Vespertilionids are uncommon in the Oligocene to Miocene but become more diverse in the Pliocene to Holocene. Emballonurids and rhinolophids appear for the first time in the Plio-Pleistocene. Pteropodids are unknown prior to the Holocene. Murids span the early Pliocene to Holocene. In the oldest assemblage at Riversleigh, one undescribed lineage resembles archaic forms otherwise only known from the fossil records of Africa and Eurasia.

Schedules for Clinical Assessment in Neuropsychiatry (SCAN): introduction to WV's mental health community

The Schedules for Clinical Assessment in Neuropsychiatry (SCAN) is a semi-structured clinical interview used by trained clinicians to assess and diagnose psychiatric disorders among adults. The SCAN core is the Present State Examination (PSE) which has been developed and tested globally during the past four decades with good validity and reliability. The SCAN was developed within the framework of the World Health Organization (WHO) and the National Institute of Mental Health (NIMH) Joint Project on Diagnosis and Classification of Mental Disorders, Alcohol and Related Problems (1). The use of the SCAN gives the flexibility to diagnose mental disorders based on the current International Classification of Disease (ICD), Diagnostic and Statistical Manual (DSM) systems or other diagnostic systems that may develop in the future. A major purpose of the SCAN is to allow comparisons of psychiatric diagnoses to be made across the world.

Suicide by fire: a contemporary method of political protest

Suicide by fire (self-incineration)for the purpose of political protest has appeared in several countries during the previous decade. In this paper, the history of this form of suicide has been explored. The authors examined all cases of suicide by fire reported in the London Times and New York Times between 1790 and 1972. Seventy-one per cent of these reported suicides occurred during the most recent decade, 1963 to 1972, with all cases of political self-incineration occurring during this period. The socio-cultural context in which this form of protest may occur, and the psychological factors in individuals who choose this method of suicide are both discussed. It is suggested that the occurrence of self-incineration as a means of political protest may be yielding to more aggressive acts of terrorism as popular methods of forcing political change.