Juliet Klasing Knowles

All Publications

• Refractory focal epilepsy in a paediatric patient with primary familial brain calcification. Seizure Knowles, J. K., Santoro, J. D., Porter, B. E., Baumer, F. M. 2018; 56: 50–52

  Abstract

  Primary familial brain calcification (PFBC), otherwise known as Fahr's disease, is a rare autosomal dominant condition with manifestations of movement disorders, neuropsychiatric symptoms, and epilepsy in a minority of PFBC patients. The clinical presentation of epilepsy in PFBC has not been described in detail. We present a paediatric patient with PFBC and refractory focal epilepsy based on seizure semiology and ictal EEG, but with generalized interictal EEG abnormalities. The patient was found to have a SLC20A2 mutation known to be pathogenic in PFBC, as well as a variant of unknown significance in SCN2A. This case demonstrates that the ictal EEG is important for accurately classifying epilepsy in affected subjects with PFBC. Further, epilepsy in PFBC may be a polygenic disorder.

  View details for DOI 10.1016/j.seizure.2018.02.001

  View details for PubMedID 29448117

• A Small Molecule p75NTR Ligand, LM11A-31, Reverses Cholinergic Neurite Dystrophy in Alzheimer's Disease Mouse Models with Mid- to Late-Stage Disease Progression. PloS one Simmons, D. A., Knowles, J. K., Belichenko, N. P., Banerjee, G., Finkle, C., Massa, S. M., Longo, F. M. 2014; 9 (8): e102136

  Abstract

  Degeneration of basal forebrain cholinergic neurons contributes significantly to the cognitive deficits associated with Alzheimer's disease (AD) and has been attributed to aberrant signaling through the neurotrophin receptor p75 (p75NTR). Thus, modulating p75NTR signaling is considered a promising therapeutic strategy for AD. Accordingly, our laboratory has developed small molecule p75NTR ligands that increase survival signaling and inhibit amyloid-β-induced degenerative signaling in in vitro studies. Previous work found that a lead p75NTR ligand, LM11A-31, prevents degeneration of cholinergic neurites when given to an AD mouse model in the early stages of disease pathology. To extend its potential clinical applications, we sought to determine whether LM11A-31 could reverse cholinergic neurite atrophy when treatment begins in AD mouse models having mid- to late stages of pathology. Reversing pathology may have particular clinical relevance as most AD studies involve patients that are at an advanced pathological stage. In this study, LM11A-31 (50 or 75 mg/kg) was administered orally to two AD mouse models, Thy-1 hAPPLond/Swe (APPL/S) and Tg2576, at age ranges during which marked AD-like pathology manifests. In mid-stage male APPL/S mice, LM11A-31 administered for 3 months starting at 6-8 months of age prevented and/or reversed atrophy of basal forebrain cholinergic neurites and cortical dystrophic neurites. Importantly, a 1 month LM11A-31 treatment given to male APPL/S mice (12-13 months old) with late-stage pathology reversed the degeneration of cholinergic neurites in basal forebrain, ameliorated cortical dystrophic neurites, and normalized increased basal forebrain levels of p75NTR. Similar results were seen in female Tg2576 mice. These findings suggest that LM11A-31 can reduce and/or reverse fundamental AD pathologies in late-stage AD mice. Thus, targeting p75NTR is a promising approach to reducing AD-related degenerative processes that have progressed beyond early stages.

  View details for DOI 10.1371/journal.pone.0102136

  View details for PubMedID 25153701

  View details for PubMedCentralID PMC4143160

• A small molecule p75(NTR) ligand prevents cognitive deficits and neurite degeneration in an Alzheimer's mouse model. Neurobiology of aging Knowles, J. K., Simmons, D. A., Nguyen, T. V., Vander Griend, L., Xie, Y., Zhang, H., Yang, T., Pollak, J., Chang, T., Arancio, O., Buckwalter, M. S., Wyss-Coray, T., Massa, S. M., Longo, F. M. 2013; 34 (8): 2052-2063

  Abstract

  The p75 neurotrophin receptor (p75(NTR)) is associated with multiple mechanisms linked to Alzheimer's disease (AD); hence, modulating its function might confer therapeutic effects. In previous in vitro work, we developed small molecule p75(NTR) ligands that inhibited amyloid-β-induced degenerative signaling and prevented neurite degeneration. In the present study, a prototype p75(NTR) ligand, LM11A-31, was administered orally to the Thy-1 hAPP(Lond/Swe) (APP(L/S)) AD mouse model. LM11A-31 reached brain concentrations known to inhibit degenerative signaling without toxicity or induction of hyperalgesia. It prevented deficits in novel object recognition after 2.5 months and, in a separate cohort, deficits in Y-maze performance after 3 months of treatment. Stereology studies found that the number and size of basal forebrain cholinergic neurons, which are normal in APP(L/S) mice, were unaffected. Neuritic dystrophy, however, was readily apparent in the basal forebrain, hippocampus and cortex, and was significantly reduced by LM11A-31, with no effect on amyloid levels. These studies reveal that p75(NTR) is an important and tractable in vivo drug target for AD, with LM11A-31 representing a novel class of therapeutic candidates.

  View details for DOI 10.1016/j.neurobiolaging.2013.02.015

  View details for PubMedID 23545424

• The p75 Neurotrophin Receptor Promotes Amyloid-beta(1-42)-Induced Neuritic Dystrophy In Vitro and In Vivo JOURNAL OF NEUROSCIENCE Knowles, J. K., Rajadas, J., Nguyen, T. V., Yang, T., LeMieux, M. C., Griend, L. V., Ishikawa, C., Massa, S. M., Wyss-Coray, T., Longo, F. M. 2009; 29 (34): 10627-10637

  Abstract

  Oligomeric forms of amyloid-beta (Abeta) are thought to play a causal role in Alzheimer's disease (AD), and the p75 neurotrophin receptor (p75(NTR)) has been implicated in Abeta-induced neurodegeneration. To further define the functions of p75(NTR) in AD, we examined the interaction of oligomeric Abeta(1-42) with p75(NTR), and the effects of that interaction on neurite integrity in neuron cultures and in a chronic AD mouse model. Atomic force microscopy was used to ascertain the aggregated state of Abeta, and fluorescence resonance energy transfer analysis revealed that Abeta oligomers interact with the extracellular domain of p75(NTR). In vitro studies of Abeta-induced death in neuron cultures isolated from wild-type and p75(NTR-/-) mice, in which the p75(NTR) extracellular domain is deleted, showed reduced sensitivity of mutant cells to Abeta-induced cell death. Interestingly, Abeta-induced neuritic dystrophy and activation of c-Jun, a known mediator of Abeta-induced deleterious signaling, were completely prevented in p75(NTR-/-) neuron cultures. Thy1-hAPP(Lond/Swe) x p75(NTR-/-) mice exhibited significantly diminished hippocampal neuritic dystrophy and complete reversal of basal forebrain cholinergic neurite degeneration relative to those expressing wild-type p75(NTR). Abeta levels were not affected, suggesting that removal of p75(NTR) extracellular domain reduced the ability of excess Abeta to promote neuritic degeneration. These findings indicate that although p75(NTR) likely does not mediate all Abeta effects, it does play a significant role in enabling Abeta-induced neurodegeneration in vitro and in vivo, establishing p75(NTR) as an important therapeutic target for AD.

  View details for DOI 10.1523/JNEUROSCI.0620-09.2009

  View details for Web of Science ID 000269317900017

  View details for PubMedID 19710315

  View details for PubMedCentralID PMC2771439

• Small Molecule, Non-Peptide p75(NTR) Ligands Inhibit A beta-Induced Neurodegeneration and Synaptic Impairment PLOS ONE Yang, T., Knowles, J. K., Lu, Q., Zhang, H., Arancio, O., Moore, L. A., Chang, T., Wang, Q., Andreasson, K., Rajadas, J., Fuller, G. G., Xie, Y., Massa, S. M., Longo, F. M. 2008; 3 (11)

  Abstract

  The p75 neurotrophin receptor (p75(NTR)) is expressed by neurons particularly vulnerable in Alzheimer's disease (AD). We tested the hypothesis that non-peptide, small molecule p75(NTR) ligands found to promote survival signaling might prevent Abeta-induced degeneration and synaptic dysfunction. These ligands inhibited Abeta-induced neuritic dystrophy, death of cultured neurons and Abeta-induced death of pyramidal neurons in hippocampal slice cultures. Moreover, ligands inhibited Abeta-induced activation of molecules involved in AD pathology including calpain/cdk5, GSK3beta and c-Jun, and tau phosphorylation, and prevented Abeta-induced inactivation of AKT and CREB. Finally, a p75(NTR) ligand blocked Abeta-induced hippocampal LTP impairment. These studies support an extensive intersection between p75(NTR) signaling and Abeta pathogenic mechanisms, and introduce a class of specific small molecule ligands with the unique ability to block multiple fundamental AD-related signaling pathways, reverse synaptic impairment and inhibit Abeta-induced neuronal dystrophy and death.

  View details for DOI 10.1371/journal.pone.0003604

  View details for Web of Science ID 000265134200003

  View details for PubMedID 18978948

  View details for PubMedCentralID PMC2575383

• Small molecule neurotrophin receptor ligands: Novel strategies for targeting Alzheimer's disease mechanisms 7th International Conference on Alzheimers Disease Drug Discovery Longo, F. M., Yang, T., Knowles, J. K., Xie, Y., Moore, L. A., Massa, S. M. BENTHAM SCIENCE PUBL LTD. 2007: 503–6

  Abstract

  A number of factors limit the therapeutic application of neurotrophin proteins, such as nerve growth factor (NGF) and brain-derived growth factor (BDNF), for Alzheimer's and other neurodegenerative diseases. These factors include unfavorable pharmacological properties typical of proteins and the pleiotropic effects mediated by protein-ligand interactions with p75(NTR), Trk, and sortilin neurotrophin receptors. Targeted modulation of p75(NTR) provides a strategy for preventing degeneration without promoting TrkA-mediated deleterious effects, and targeted activation of TrkB might achieve more favorable neurotrophic effects than those achieved by concomitant activation of p75(NTR) and TrkB. The discovery of small molecules functioning as ligands at specific neurotrophin receptors has made possible for the first time approaches for modulating selected components of neurotrophin signaling processes for the purpose of modulating underlying Alzheimer's disease mechanisms.

  View details for Web of Science ID 000253592000002

  View details for PubMedID 18220511