Potassium Channel Modulators to Treat Fragile X

With $246,000 in funding from FRAXA over 2012-2014, the Yale University team of Leonard Kaczmarek, PhD, showed that loss of FMRP leads to an increased Kv3.1 potassium currents and decreased Slack potassium currents in neurons. Both of these changes impair timing of action potentials in auditory neurons (and likely others throughout the brain). The team also found that the firing pattern of neurons in response to repeated stimulation is severely abnormal in Fragile X mice. Based on these results, they are collaborating with the UK-based company Autifony to develop and test advanced compounds which may reverse these deficits.

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Fragile X Syndrome Protein Linked to Breast Cancer Progression

Claudia Bagni (VIB/KU Leuven, Belgium, and the University of Rome, Italy) and colleagues have identified the way Fragile X Mental Retardation Protein or FMRP contributes to the progression of breast cancer. The researchers demonstrated that FMRP acts as a master switch controlling the levels of several proteins involved in different stages of aggressive breast cancer, including the invasion of cancer cells into blood vessels and the spread of these cancer cells to other tissues forming metastasis.

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Social Behavior as an Outcome Measure for Fragile X Clinical Trials

One of the features of the Fragile X mouse model which is relevant to the human Fragile X syndrome (and autism) is social behavior. Several tests show consistent social behavioral abnormalities in the Fragile X mouse model. With a $140,000 grant from FRAXA Research Foundation in 2012-2013, Dr. Willemsen at Erasmus University used social behavior tests to measure the effectiveness of several drug strategies.

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Development of a Novel GABA-A Agonist in Fragile X Syndrome

Tori Shaeffer

Of the many genes known to be regulated by FMRP, the gamma-aminobutyric acid receptor A (GABA(A)), is gaining attention as a potential target for the treatment of FXS. Mounting evidence suggests decreased expression and functioning of GABA(A) is involved in the pathophysiology of FXS. Non-selective GABA(A) agonism in animal models of FXS has been associated with normalization of morphological features, GABA(A) expression, and behavior. However, the clinical use of these agents in Fragile X is associated with unwanted side-effects, such as sedation, dulling of cognition, and occasional paradoxical agitation, which limits their use.

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Matrix Metalloproteinase Therapeutic Treatments for Fragile X Syndrome

Kendal Broadie

With a $157,000 grant from the FRAXA Research Foundation in 2012-2013, Dr. Kendal Broadie and Dr. Cheryl Gatto worked to define the distinct but also overlapping roles for MMP-1 and MMP-2 in synaptic structural and functional development. In drug studies with Fragile X fruit flies, they will be testing a range of MMPIs in drug treatments to compare effectiveness during development and at maturity, in order to define the contributions of FXS developmental impairments and adult recovery/plasticity.

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Lovastatin Discovery in Fragile X Mice Leads FRAXA to Fund Clinical Trials

Dr. Emily Osterweil

Dr. Emily Osterweil was awarded the FRAXA Pioneer Award at the opening dinner of the 2011 FRAXA Investigators Meeting in Southbridge, MA for her work demonstrating that Lovastatin could treat Fragile X. Dr. Osterweil conducted her experiments in the MIT laboratory of Dr. Mark Bear and has since established her own laboratory at the University of Edinburgh. The team discovered that lovastatin, a drug widely prescribed for high cholesterol, can correct excess hippocampal protein synthesis in the mouse model of FXS and can prevent epileptogenesis. The work is published in the prestigious neuroscience journal Neuron: Lovastatin Corrects Excess Protein Synthesis and Prevents Epileptogenesis in a Mouse Model of Fragile X Syndrome.

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Treatment of Fragile X Syndrome via Dopamine Enhancers and Glutamate Inhibitors

Justin Cowan, PhD

FRAXA Awards $50,000 in 2011 and $50,000 in 2010 to Patricia Cogram, PhD for treatment of Fragile X syndrome via Dopamine Enhancers and Glutamate Inhibitors. This project aims to follow up our and others observations that the dopamine receptor is under expressed in the Fragile X syndrome and thus determine the effectiveness of targeted pharmacological treatments in Fragile X syndrome.

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Developing IPS cells to Screen Drugs which can Reactivate the FMR1 Gene

Anita Bhattacharyya, PhD

With $146,000 grant from FRAXA Research Foundation over 2012-2013, Drs. Anita Bhattacharyya and Xinyu Zhao at the University of Wisconsin developed a new mouse model of Fragile X syndrome which will enable testing of gene reactivation and gene therapy approaches to treatment. They transplanted human Fragile X neural cells differentiated from induced pluripotent stem cells into brains of neonatal mice and then testing for FMR1 reactivation. In 2015, The John Merck Fund assumed support for this work with a generous grant of $750,000 to the scientists. Results published.

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A Developmental Switch Exists in the Effects of FMRP

Dr. Kimberly Huber

With a $90,00 grant from FRAXA Research Foundation for 2010-2011, Dr. Kimberly Huber and her team at the University of Texas at Southwestern found that there is a developmental switch of postsynaptic FMRP on synaptic function. This switch is controlled by MEF2 transcriptional activity. Proper synapse maturation and elimination is crucial for the establishment of appropriate neural circuits that underlie sensory processing and cognition. Neuron of Fragile X patients as well as in the mouse model of Fragile X, Fmr1 KO mice, display more dendritic spines, the point of contact for excitatory synapses, as well as long and thin filopodia resembling immature spines. This suggests Fragile X mental retardation protein (FMRP) has a role in promoting synapse maturation and elimination.

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Synaptic Actin Signaling Pathways in Fragile X

With a $163,356 grant from FRAXA Research Foundation in 2010-12, Dr. Scott Soderling and Dr. Hwan Kim at Duke University bred the standard mouse model of Fragile X syndrome to their lines of mice that express reduced levels of several key proteins that modulate synaptic actin. These compound mutant mice were compared to FXS mice to determine if genetically impairing pathways to the actin cytoskeleton can rescue deficits in the FXS mice.

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Inherited Channelopathies in Cortical Circuits of Fmr1 KO Mice

Andreas Frick, PhD

With this two year award of $90,000, Dr. Zhang and Principal Investigator Dr. Andreas Frick at Neurocentre Magendie in France investigated channelopathies using Fragile X mice. Many other proteins are misregulated as a result of the absence of FMRP. It is known that many ion channels, the pores in the cell membrane which allow neurons to conduct electrical impulses, have altered levels in Fragile X. This state is sometime called a “channelopathy” in the pharma world. This group is studying the effect of specific alterations in ion channels, and potential therapeutic effects of drugs which open and close these channels.

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