West Lafayette, IN, United States
West Lafayette, IN, United States

Time filter

Source Type

Torregrosa R.,Neurogate Therapeutics, Inc. | Yang X.-F.,University of Arizona | Dustrude E.T.,Paul and Carole Stark Neurosciences Research Institute | Wang Y.,University of Arizona | And 10 more authors.
Journal of Medicinal Chemistry | Year: 2014

We prepared 13 derivatives of N-(biphenyl-4′-yl)methyl (R)-2-acetamido-3-methoxypropionamide that differed in type and placement of a R-substituent in the terminal aryl unit. We demonstrated that the R-substituent impacted the compound's whole animal and cellular pharmacological activities. In rodents, select compounds exhibited excellent anticonvulsant activities and protective indices (PI = TD50/ED50) that compared favorably with clinical antiseizure drugs. Compounds with a polar, aprotic R-substituent potently promoted Na+ channel slow inactivation and displayed frequency (use) inhibition of Na+ currents at low micromolar concentrations. The possible advantage of affecting these two pathways to decrease neurological hyperexcitability is discussed. © 2014 American Chemical Society.


Ju W.,Indiana University | Ju W.,Jilin University | Wilson S.M.,Paul and Carole Stark Neurosciences Research Institute | Brittain J.M.,Paul and Carole Stark Neurosciences Research Institute | And 4 more authors.
Channels | Year: 2013

The axon/dendrite specification collapsin response mediator protein 2 (CRMP2) bidirectionally modulates N-type voltagegated Ca2+ channels (CaV2.2). Here we demonstrate that small ubiquitin-like modifier (SUMO) protein modifies CRMP2 via the SUMO E2-conjugating enzyme Ubc9 in vivo. Removal of a SUMO conjugation site KMD in CRMP2 (K374A/M375A/D376A; CRMP2AAA) resulted in loss of SUMOylated CRMP2 without compromising neurite branching, a canonical hallmark of CRMP2 function. Increasing SUMOylation levels correlated inversely with calcium influx in sensory neurons. CRMP2 de SUMOylation by SUMO proteases SENP1 and SENP2 normalized calcium influx to those in the CRMP2 AAA mutant. Thus, our results identify a novel role for SUMO modification in CRMP2/CaV2.2 signaling pathway. ©2013 Landes Bioscience.


PubMed | Paul and Carole Stark Neurosciences Research Institute, Indiana University and Janssen Research and Development LLC
Type: | Journal: Psychoneuroendocrinology | Year: 2016

Distressing symptoms such as hot flashes and sleep disturbances affect over 70% of women approaching menopause for an average of 4-7 years, and recent large cohort studies have shown that anxiety and stress are strongly associated with more severe and persistent hot flashes and can induce hot flashes. Although high estrogen doses alleviate symptoms, extended use increases health risks, and current non-hormonal therapies are marginally better than placebo. The lack of effective non-hormonal treatments is largely due to the limited understanding of the mechanisms that underlie menopausal symptoms. One mechanistic pathway that has not been explored is the wake-promoting orexin neuropeptide system. Orexin is exclusively synthesized in the estrogen receptor rich perifornical hypothalamic region, and has an emerging role in anxiety and thermoregulation. In female rodents, estrogens tonically inhibit expression of orexin, and estrogen replacement normalizes severely elevated central orexin levels in postmenopausal women. Using an ovariectomy menopause model, we demonstrated that an anxiogenic compound elicited exacerbated hot flash-associated increases in tail skin temperature (TST, that is blocked with estrogen), and cellular responses in orexin neurons and efferent targets. Furthermore, systemic administration of centrally active, selective orexin 1 or 2 and dual receptor antagonists attenuated or blocked TST responses, respectively. This included the reformulated Suvorexant, which was recently FDA-approved for treating insomnia. Collectively, our data support the hypothesis that dramatic loss of estrogen tone during menopausal states leads to a hyperactive orexin system that contributes to symptoms such as anxiety, insomnia, and more severe hot flashes. Additionally, orexin receptor antagonists may represent a novel non-hormonal therapy for treating menopausal symptoms, with minimal side effects.


Ju W.,Paul and Carole Stark Neurosciences Research Institute | Ju W.,Jilin University | Li Q.,Jilin University | Allette Y.M.,Paul and Carole Stark Neurosciences Research Institute | And 4 more authors.
Journal of Neurochemistry | Year: 2013

The N-type voltage-gated calcium channel (CaV2.2) is a clinically endorsed target in chronic pain treatments. As directly targeting the channel can lead to multiple adverse side effects, targeting modulators of CaV2.2 may prove better. We previously identified ST1-104, a short peptide from the collapsin response mediator protein 2 (CRMP2), which disrupted the CaV2.2-CRMP2 interaction and suppressed a model of HIV-related neuropathy induced by anti-retroviral therapy but not traumatic neuropathy. Here, we report ST2-104 -a peptide wherein the cell-penetrating TAT motif has been supplanted with a homopolyarginine motif, which dose-dependently inhibits the CaV2.2-CRMP2 interaction and inhibits depolarization-evoked Ca2+ influx in sensory neurons. Ca2+ influx via activation of vanilloid receptors is not affected by either peptide. Systemic administration of ST2-104 does not affect thermal or tactile nociceptive behavioral changes. Importantly, ST2-104 transiently reduces persistent mechanical hypersensitivity induced by systemic administration of the anti-retroviral drug 2′,3′-dideoxycytidine (ddC) and following tibial nerve injury (TNI). Possible mechanistic explanations for the broader efficacy of ST2-104 are discussed. Chronic neuropathic pain remains a worldwide medical problem with few effective therapies. Drugs targeting calcium channels are in clinical use as first-line treatments for alleviation of neuropathic pain. However, targeting these channels can lead to serious complications. Here, we report that a peptide derived from CRMP2 - a modulator of calcium channels, offers problem-free pain relief in rodent models of neuropathic pain. © 2012 International Society for Neurochemistry.


Khanna R.,Paul and Carole Stark Neurosciences Research Institute | Khanna R.,Indiana University | Khanna R.,Sophia Therapeutics LLC | Wilson S.M.,Paul and Carole Stark Neurosciences Research Institute | And 5 more authors.
Future Neurology | Year: 2012

CRMP2, also known as DPYSL2/DRP2, Unc-33, Ulip or TUC2, is a cytosolic phosphoprotein that mediates axon/dendrite specification and axonal growth. Mapping the CRMP2 interactome has revealed previously unappreciated functions subserved by this protein. Together with its canonical roles in neurite growth and retraction and kinesin-dependent axonal transport, it is now known that CRMP2 interacts with numerous binding partners to affect microtubule dynamics; protein endocytosis and vesicular cycling, synaptic assembly, calcium channel regulation and neurotransmitter release. CRMP2 signaling is regulated by post-translational modifications, including glycosylation, oxidation, proteolysis and phosphorylation; the latter being a fulcrum of CRMP2 functions. Here, the putative roles of CRMP2 in a panoply of neurodegenerative, sensory and motor neuron, and central disorders are discussed and evidence is presented for therapeutic strategies targeting CRMP2 functions. © 2012 Future Medicine Ltd.


Dustrude E.T.,Paul and Carole Stark Neurosciences Research Institute | Wilson S.M.,Paul and Carole Stark Neurosciences Research Institute | Ju W.,Indiana University | Xiao Y.,Indiana University | And 2 more authors.
Journal of Biological Chemistry | Year: 2013

Background: Post-translational modifications of CRMP2 protein direct its regulation of effector proteins. Results: Destruction of a CRMP2 SUMOylation site reduces surface expression and current density of sodium channel NaV1.7. Conclusion: CRMP2 SUMOylation choreographs NaV1.7, but not NaV1.1 or NaV1.3, trafficking. Significance: Learning how neuronal NaV1.7 trafficking is modulated by CRMP2 is important for understanding the mechanism of action of NaV-targeted anti-epileptic and anti-nociceptive drugs. Voltage-gated sodium channel (NaV) trafficking is incompletely understood. Post-translational modifications of NaVs and/or auxiliary subunits and protein-protein interactions have been posited as NaV-trafficking mechanisms. Here, we tested if modification of the axonal collapsin response mediator protein 2 (CRMP2) by a small ubiquitin-like modifier (SUMO) could affect NaV trafficking; CRMP2 alters the extent of NaV slow inactivation conferred by the anti-epileptic (R)-lacosamide, implying NaV-CRMP2 functional coupling. Expression of a CRMP2 SUMOylation-incompetent mutant (CRMP2-K374A) in neuronal model catecholamine A differentiated (CAD) cells did not alter lacosamide-induced NaV slow inactivation compared with CAD cells expressing wild type CRMP2. Like wild type CRMP2, CRMP2-K374A expressed robustly in CAD cells. Neurite outgrowth, a canonical CRMP2 function, was moderately reduced by the mutation but was still significantly higher than enhanced GFP-transfected cortical neurons. Notably, huwentoxin-IV-sensitive NaV1.7 currents, which predominate inCADcells, were significantly reduced inCADcells expressing CRMP2-K374A. Increasing deSUMOylation with sentrin/SUMO-specific protease SENP1 or SENP2 in wild type CRMP2-expressing CAD cells decreased NaV1.7 currents. Consistent with a reduction in current density, biotinylation revealed a significant reduction in surface NaV1.7 levels in CAD cells expressing CRMP2-K374A; surface NaV1.7 expression was also decreased by SENP1 + SENP2 overexpression. Currents in HEK293 cells stably expressing NaV1.7 were reduced by CRMP2-K374A in a manner dependent on the E2-conjugating enzyme Ubc9. No decrement in current density was observed in HEK293 cells co-expressing CRMP2-K374A and NaV1.1 or NaV1.3. Diminution of sodium currents, largely NaV1.7, was recapitulated in sensory neurons expressing CRMP2-K374A. Our study elucidates a novel regulatory mechanism that utilizes CRMP2 SUMOylation to choreograph NaV1.7 trafficking. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.


Piekarz A.D.,Indianapolis | Due M.R.,Health Information and Translational science Building | Khanna M.,Health Information and Translational science Building | Wang B.,Health Information and Translational science Building | And 13 more authors.
Molecular Pain | Year: 2012

Background: The ubiquity of protein-protein interactions in biological signaling offers ample opportunities for therapeutic intervention. We previously identified a peptide, designated CBD3, that suppressed inflammatory and neuropathic behavioral hypersensitivity in rodents by inhibiting the ability of collapsin response mediator protein 2 (CRMP-2) to bind to N-type voltage-activated calcium channels (CaV2.2) [Brittain et al. Nature Medicine 17:822-829 (2011)].Results and discussion: Here, we utilized SPOTScan analysis to identify an optimized variation of the CBD3 peptide (CBD3A6K) that bound with greater affinity to Ca2+ channels. Molecular dynamics simulations demonstrated that the CBD3A6K peptide was more stable and less prone to the unfolding observed with the parent CBD3 peptide. This mutant peptide, conjugated to the cell penetrating motif of the HIV transduction domain protein TAT, exhibited greater anti-nociception in a rodent model of AIDS therapy-induced peripheral neuropathy when compared to the parent TAT-CBD3 peptide. Remarkably, intraperitoneal administration of TAT-CBD3A6K produced none of the minor side effects (i.e. tail kinking, body contortion) observed with the parent peptide. Interestingly, excitability of dissociated small diameter sensory neurons isolated from rats was also reduced by TAT-CBD3A6K peptide suggesting that suppression of excitability may be due to inhibition of T- and R-type Ca2+ channels. TAT-CBD3A6K had no effect on depolarization-evoked calcitonin gene related peptide (CGRP) release compared to vehicle control.Conclusions: Collectively, these results establish TAT-CBD3A6K as a peptide therapeutic with greater efficacy in an AIDS therapy-induced model of peripheral neuropathy than its parent peptide, TAT-CBD3. Structural modifications of the CBD3 scaffold peptide may result in peptides with selectivity against a particular subset of voltage-gated calcium channels resulting in a multipharmacology of action on the target. © 2012 Piekarz et al.; licensee BioMed Central Ltd.


Park K.D.,University of North Carolina at Chapel Hill | Park K.D.,Korea Institute of Science and Technology | Yang X.-F.,University of Arizona | Dustrude E.T.,Paul and Carole Stark Neurosciences Research Institute | And 6 more authors.
ACS Chemical Neuroscience | Year: 2015

The functionalized amino acid, lacosamide ((R)-2), and the α-aminoamide, safinamide ((S)-3), are neurological agents that have been extensively investigated and have displayed potent anticonvulsant activities in seizure models. Both compounds have been reported to modulate voltage-gated sodium channel activity. We have prepared a series of chimeric compounds, (R)-7-(R)-10, by merging key structural units in these two clinical agents, and then compared their activities with (R)-2 and (S)-3. Compounds were assessed for their ability to alter sodium channel kinetics for inactivation, frequency (use)-dependence, and steady-state activation and fast inactivation. We report that chimeric compounds (R)-7-(R)-10 in catecholamine A-differentiated (CAD) cells and embryonic rat cortical neurons robustly enhanced sodium channel inactivation at concentrations far lower than those required for (R)-2 and (S)-3, and that (R)-9 and (R)-10, unlike (R)-2 and (S)-3, produce sodium channel frequency (use)-dependence at low micromolar concentrations. We further show that (R)-7-(R)-10 displayed excellent anticonvulsant activities and pain-attenuating properties in the animal formalin model. Of these compounds, only (R)-7 reversed mechanical hypersensitivity in the tibial-nerve injury model for neuropathic pain in rats. © 2014 American Chemical Society.


PubMed | Paul and Carole Stark Neurosciences Research Institute
Type: Journal Article | Journal: Journal of neurochemistry | Year: 2013

The N-type voltage-gated calcium channel (CaV2.2) is a clinically endorsed target in chronic pain treatments. As directly targeting the channel can lead to multiple adverse side effects, targeting modulators of CaV2.2 may prove better. We previously identified ST1-104, a short peptide from the collapsin response mediator protein 2 (CRMP2), which disrupted the CaV2.2-CRMP2 interaction and suppressed a model of HIV-related neuropathy induced by anti-retroviral therapy but not traumatic neuropathy. Here, we report ST2-104 -a peptide wherein the cell-penetrating TAT motif has been supplanted with a homopolyarginine motif, which dose-dependently inhibits the CaV2.2-CRMP2 interaction and inhibits depolarization-evoked Ca(2+) influx in sensory neurons. Ca(2+) influx via activation of vanilloid receptors is not affected by either peptide. Systemic administration of ST2-104 does not affect thermal or tactile nociceptive behavioral changes. Importantly, ST2-104 transiently reduces persistent mechanical hypersensitivity induced by systemic administration of the anti-retroviral drug 2,3-dideoxycytidine (ddC) and following tibial nerve injury (TNI). Possible mechanistic explanations for the broader efficacy of ST2-104 are discussed.


PubMed | Indiana University and Paul and Carole Stark Neurosciences Research Institute
Type: Journal Article | Journal: Science translational medicine | Year: 2014

Traumatic brain injury (TBI) results in systemic inflammatory responses that affect the lung. This is especially critical in the setting of lung transplantation, where more than half of donor allografts are obtained postmortem from individuals with TBI. The mechanism by which TBI causes pulmonary dysfunction remains unclear but may involve the interaction of high-mobility group box-1 (HMGB1) protein with the receptor for advanced glycation end products (RAGE). To investigate the role of HMGB1 and RAGE in TBI-induced lung dysfunction, RAGE-sufficient (wild-type) or RAGE-deficient (RAGE(-/-)) C57BL/6 mice were subjected to TBI through controlled cortical impact and studied for cardiopulmonary injury. Compared to control animals, TBI induced systemic hypoxia, acute lung injury, pulmonary neutrophilia, and decreased compliance (a measure of the lungs ability to expand), all of which were attenuated in RAGE(-/-) mice. Neutralizing systemic HMGB1 induced by TBI reversed hypoxia and improved lung compliance. Compared to wild-type donors, lungs from RAGE(-/-) TBI donors did not develop acute lung injury after transplantation. In a study of clinical transplantation, elevated systemic HMGB1 in donors correlated with impaired systemic oxygenation of the donor lung before transplantation and predicted impaired oxygenation after transplantation. These data suggest that the HMGB1-RAGE axis plays a role in the mechanism by which TBI induces lung dysfunction and that targeting this pathway before transplant may improve recipient outcomes after lung transplantation.

Loading Paul and Carole Stark Neurosciences Research Institute collaborators
Loading Paul and Carole Stark Neurosciences Research Institute collaborators