Charles Gilman - Academia.edu (original) (raw)

Papers by Charles Gilman

Research paper thumbnail of Top soil physical and chemical properties in Kazakhstan across a north-south gradient

Research paper thumbnail of A Preparative TLC Applicator

Journal of Chemical Education, 2001

Research paper thumbnail of An in vitro model of caloric restriction

Experimental Gerontology, 2003

Research paper thumbnail of RyR1 S-Nitrosylation Underlies Environmental Heat Stroke and Sudden Death in Y522S RyR1 Knockin Mice

Research paper thumbnail of Apoptotic and genotoxic effects of low-intensity ultrasound on healthy and leukemic human peripheral mononuclear blood cells

Journal of Medical Ultrasonics

To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound c... more To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound contrast agent (SonoVue; Bracco Diagnostics Inc., EU) on human peripheral mononuclear blood cells (PMBCs). PMBCs were subjected to a low-intensity ultrasound field (1-MHz frequency; spatial peak temporal average intensity 0.18 W/cm2) followed by analysis for apoptosis and DNA damage (single-strand breaks + double-strand breaks). The comet assay was then repeated after 2 h to examine the ability of cells to repair DNA breaks. The results demonstrated that low-intensity ultrasound was capable of selectively inducing apoptosis in leukemic PMBCs, but not in healthy cells. The introduction of ultrasound contrast agent SonoVue resulted in an increase in apoptosis in both groups. DNA analysis after ultrasound exposure indicated that ultrasound triggered DNA damage in leukemic PMBCs (66.05 ± 13.36%), while the damage was minimal (7.01 ± 0.89%) in control PMBCs. However, both cell lines demonstrated an ability to repair DNA single- and double-strand breaks 2 h after sonication. The study demonstrated that low-intensity ultrasound selectively induced apoptosis in cancer PMBCs. Ultrasound-induced DNA damage was observed primarily in leukemic PMBCs. Nevertheless, both cell lines were able to repair ultrasound-mediated DNA strand breaks.

Research paper thumbnail of Novel Small Molecule Inhibitors of Cancer Stem Cell Signaling Pathways

Stem Cell Reviews and Reports, 2015

The main aim of oncologists worldwide is to understand and then intervene in the primary tumor in... more The main aim of oncologists worldwide is to understand and then intervene in the primary tumor initiation and propagation mechanisms. This is essential to allow targeted elimination of cancer cells without altering normal mitotic cells. Currently, there are two main rival theories describing the process of tumorigenesis. According to the Stochastic Model, potentially any cell, once defunct, is capable of initiating carcinogenesis. Alternatively the Cancer Stem Cell (CSC) Model posits that only a small fraction of undifferentiated tumor cells are capable of triggering carcinogenesis. Like healthy stem cells, CSCs are also characterized by a capacity for self-renewal and the ability to generate differentiated progeny, possibly mediating treatment resistance, thus leading to tumor recurrence and metastasis. Moreover, molecular signaling profiles are similar between CSCs and normal stem cells, including Wnt, Notch and Hedgehog pathways. Therefore, development of novel chemotherapeutic agents and proteins (e.g., enzymes and antibodies) specifically targeting CSCs are attractive pharmaceutical candidates. This article describes small molecule inhibitors of stem cell pathways Wnt, Notch and Hedgehog, and their recent chemotherapy clinical trials.

Research paper thumbnail of Management of Super-Refractory Status Epilepticus with Isoflurane and Hypothermia

Frontiers in Neurology, 2015

Super-refractory status epilepticus (SRSE) is defined as status epilepticus that continues 24 h o... more Super-refractory status epilepticus (SRSE) is defined as status epilepticus that continues 24 h or more after the onset of anesthesia, and includes those cases in which epilepsy is recurrent upon treatment reduction. We describe the presentation and successful management of a male patient with SRSE using the inhaled anesthetic isoflurane, and mild hypothermia (HT). The potential utility of combined HT and volatile anesthesia is discussed.

Research paper thumbnail of Chapter 6 Calcium and the pathogenesis of neurodegenerative disorders

Advances in Cell Aging and Gerontology, 2002

Research paper thumbnail of Towards a Comprehensive Catalog of Zebrafish Behavior 1.0 and Beyond

Zebrafish, 2013

Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavior... more Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.

Research paper thumbnail of Do Apoptotic Mechanisms Regulate Synaptic Plasticity and Growth-Cone Motility?

NeuroMolecular Medicine, 2002

Research paper thumbnail of Glucagon-like peptide 1 modulates calcium responses to glutamate and membrane depolarization in hippocampal neurons

Journal of Neurochemistry, 2003

Glucagon-like peptide 1 (GLP-1) activates receptors coupled to cAMP production and calcium influx... more Glucagon-like peptide 1 (GLP-1) activates receptors coupled to cAMP production and calcium influx in pancreatic cells, resulting in enhanced glucose sensitivity and insulin secretion. Despite evidence that the GLP-1 receptor is present and active in neurons, little is known of the roles of GLP-1 in neuronal physiology. As GLP-1 modulates calcium homeostasis in pancreatic beta cells, and because calcium plays important roles in neuronal plasticity and neurodegenerative processes, we examined the effects of GLP-1 on calcium regulation in cultured rat hippocampal neurons. When neurons were pre-treated with GLP-1, calcium responses to glutamate and membrane depolarization were attenuated. Whole-cell patch clamp analyses showed that glutamateinduced currents and currents through voltage-dependent calcium channels were significantly decreased in neurons pretreated with GLP-1. Pre-treatment of neurons with GLP-1 significantly decreased their vulnerability to death induced by glutamate. Acute application of GLP-1 resulted in a transient elevation of intracellular calcium levels, consistent with the established effects of GLP-1 on cAMP production and activation of cAMP response element-binding protein. Collectively, our findings suggest that, by modulating calcium responses to glutamate and membrane depolarization, GLP-1 may play important roles in regulating neuronal plasticity and cell survival.

Research paper thumbnail of Identification of Cysteines Involved in S-Nitrosylation, S-Glutathionylation, and Oxidation to Disulfides in Ryanodine Receptor Type 1

Journal of Biological Chemistry, 2006

The skeletal muscle Ca 2؉-release channel (ryanodine receptor type 1 (RyR1)) is a redox sensor, s... more The skeletal muscle Ca 2؉-release channel (ryanodine receptor type 1 (RyR1)) is a redox sensor, susceptible to reversible S-nitrosylation, S-glutathionylation, and disulfide oxidation. So far, Cys-3635 remains the only cysteine residue identified as functionally relevant to the redox sensing properties of the channel. We demonstrate that expression of the C3635A-RyR1 mutant in RyR1-null myotubes alters the sensitivity of the ryanodine receptor to activation by voltage, indicating that Cys-3635 is involved in voltage-gated excitation-contraction coupling. However, H 2 O 2 treatment of C3635A-RyR1 channels or wildtype RyR1, following their expression in human embryonic kidney cells, enhances [ 3 H]ryanodine binding to the same extent, suggesting that cysteines other than Cys-3635 are responsible for the oxidative enhancement of channel activity. Using a combination of Western blotting and sulfhydryl-directed fluorescent labeling, we found that two large regions of RyR1 (amino acids 1-2401 and 3120-4475), previously shown to be involved in disulfide bond formation, are also major sites of both S-nitrosylation and S-glutathionylation. Using selective isotopecoded affinity tag labeling of RyR1 and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy, we identified, out of the 100 cysteines in each RyR1 subunit, 9 that are endogenously modified (Cys-36, Cys-315, Cys-811, Cys-906, Cys-1591, Cys-2326, Cys-2363, Cys-3193, and Cys-3635) and another 3 residues that were only modified with exogenous redox agents (Cys-253, Cys-1040, and Cys-1303). We also identified the types of redox modification each of these cysteines can undergo. In summary, we have identified a discrete subset of cysteines that are likely to be involved in the functional response of RyR1 to different redox modifications (S-nitrosylation, S-glutathionylation, and oxidation to disulfides). Ca 2ϩ-release channels, also known as ryanodine receptors (RyRs), 2 play crucial roles in several cellular Ca 2ϩ-signaling pathways. These channels contribute to muscle contraction, secretion, synaptic plasticity and learning, fecundation, and apoptosis. Consistent with these important roles in cell signaling, RyRs are tightly regulated by a variety of ions and small molecules, protein-protein interactions, and post-translational modifications (for recent reviews see Refs. 1-3). RyRs, homotetramers with subunits that are Ͼ5000 amino acids, are the largest integral membrane proteins reported to date (ϳ2.3 MDa). In rabbit skeletal muscle, each subunit of the type 1 RyR (RyR1; Swiss Prot accession P11716) is comprised of 5037 amino acid residues, of which 100 are cysteines (4). Sulfhydryl reagents, however, modify only a few of these cysteines at physiological pH, which are known as the "hyper-reactive" cysteines (5). Modification of these hyper-reactive cysteine residues has marked effects on RyR1 channel open probability. RyR1 activity is enhanced in vitro by molecular oxygen (O 2), superoxide anion (O 2 .), hydrogen peroxide (H 2 O 2), hydroxyl

Research paper thumbnail of Do apoptotic mechanisms regulate synaptic plasticity and growth-cone motility?

Neuromolecular Medicine, 2002

Signals between neurons are transduced primarily by receptors, and second messenger and kinase ca... more Signals between neurons are transduced primarily by receptors, and second messenger and kinase cascades, located in pre- and postsynaptic terminals. Such synaptic signaling pathways include those activated by neurotransmitters, cytokines, neurotrophic factors, and cell-adhesion molecules. Many of these signaling systems are also localized in the growth cones of axons and dendrites, where they control pathfinding and synaptogenesis during development. Although

Research paper thumbnail of Top soil physical and chemical properties in Kazakhstan across a north-south gradient

Research paper thumbnail of A Preparative TLC Applicator

Journal of Chemical Education, 2001

Research paper thumbnail of An in vitro model of caloric restriction

Experimental Gerontology, 2003

Research paper thumbnail of RyR1 S-Nitrosylation Underlies Environmental Heat Stroke and Sudden Death in Y522S RyR1 Knockin Mice

Research paper thumbnail of Apoptotic and genotoxic effects of low-intensity ultrasound on healthy and leukemic human peripheral mononuclear blood cells

Journal of Medical Ultrasonics

To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound c... more To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound contrast agent (SonoVue; Bracco Diagnostics Inc., EU) on human peripheral mononuclear blood cells (PMBCs). PMBCs were subjected to a low-intensity ultrasound field (1-MHz frequency; spatial peak temporal average intensity 0.18 W/cm2) followed by analysis for apoptosis and DNA damage (single-strand breaks + double-strand breaks). The comet assay was then repeated after 2 h to examine the ability of cells to repair DNA breaks. The results demonstrated that low-intensity ultrasound was capable of selectively inducing apoptosis in leukemic PMBCs, but not in healthy cells. The introduction of ultrasound contrast agent SonoVue resulted in an increase in apoptosis in both groups. DNA analysis after ultrasound exposure indicated that ultrasound triggered DNA damage in leukemic PMBCs (66.05 ± 13.36%), while the damage was minimal (7.01 ± 0.89%) in control PMBCs. However, both cell lines demonstrated an ability to repair DNA single- and double-strand breaks 2 h after sonication. The study demonstrated that low-intensity ultrasound selectively induced apoptosis in cancer PMBCs. Ultrasound-induced DNA damage was observed primarily in leukemic PMBCs. Nevertheless, both cell lines were able to repair ultrasound-mediated DNA strand breaks.

Research paper thumbnail of Novel Small Molecule Inhibitors of Cancer Stem Cell Signaling Pathways

Stem Cell Reviews and Reports, 2015

The main aim of oncologists worldwide is to understand and then intervene in the primary tumor in... more The main aim of oncologists worldwide is to understand and then intervene in the primary tumor initiation and propagation mechanisms. This is essential to allow targeted elimination of cancer cells without altering normal mitotic cells. Currently, there are two main rival theories describing the process of tumorigenesis. According to the Stochastic Model, potentially any cell, once defunct, is capable of initiating carcinogenesis. Alternatively the Cancer Stem Cell (CSC) Model posits that only a small fraction of undifferentiated tumor cells are capable of triggering carcinogenesis. Like healthy stem cells, CSCs are also characterized by a capacity for self-renewal and the ability to generate differentiated progeny, possibly mediating treatment resistance, thus leading to tumor recurrence and metastasis. Moreover, molecular signaling profiles are similar between CSCs and normal stem cells, including Wnt, Notch and Hedgehog pathways. Therefore, development of novel chemotherapeutic agents and proteins (e.g., enzymes and antibodies) specifically targeting CSCs are attractive pharmaceutical candidates. This article describes small molecule inhibitors of stem cell pathways Wnt, Notch and Hedgehog, and their recent chemotherapy clinical trials.

Research paper thumbnail of Management of Super-Refractory Status Epilepticus with Isoflurane and Hypothermia

Frontiers in Neurology, 2015

Super-refractory status epilepticus (SRSE) is defined as status epilepticus that continues 24 h o... more Super-refractory status epilepticus (SRSE) is defined as status epilepticus that continues 24 h or more after the onset of anesthesia, and includes those cases in which epilepsy is recurrent upon treatment reduction. We describe the presentation and successful management of a male patient with SRSE using the inhaled anesthetic isoflurane, and mild hypothermia (HT). The potential utility of combined HT and volatile anesthesia is discussed.

Research paper thumbnail of Chapter 6 Calcium and the pathogenesis of neurodegenerative disorders

Advances in Cell Aging and Gerontology, 2002

Research paper thumbnail of Towards a Comprehensive Catalog of Zebrafish Behavior 1.0 and Beyond

Zebrafish, 2013

Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavior... more Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.

Research paper thumbnail of Do Apoptotic Mechanisms Regulate Synaptic Plasticity and Growth-Cone Motility?

NeuroMolecular Medicine, 2002

Research paper thumbnail of Glucagon-like peptide 1 modulates calcium responses to glutamate and membrane depolarization in hippocampal neurons

Journal of Neurochemistry, 2003

Glucagon-like peptide 1 (GLP-1) activates receptors coupled to cAMP production and calcium influx... more Glucagon-like peptide 1 (GLP-1) activates receptors coupled to cAMP production and calcium influx in pancreatic cells, resulting in enhanced glucose sensitivity and insulin secretion. Despite evidence that the GLP-1 receptor is present and active in neurons, little is known of the roles of GLP-1 in neuronal physiology. As GLP-1 modulates calcium homeostasis in pancreatic beta cells, and because calcium plays important roles in neuronal plasticity and neurodegenerative processes, we examined the effects of GLP-1 on calcium regulation in cultured rat hippocampal neurons. When neurons were pre-treated with GLP-1, calcium responses to glutamate and membrane depolarization were attenuated. Whole-cell patch clamp analyses showed that glutamateinduced currents and currents through voltage-dependent calcium channels were significantly decreased in neurons pretreated with GLP-1. Pre-treatment of neurons with GLP-1 significantly decreased their vulnerability to death induced by glutamate. Acute application of GLP-1 resulted in a transient elevation of intracellular calcium levels, consistent with the established effects of GLP-1 on cAMP production and activation of cAMP response element-binding protein. Collectively, our findings suggest that, by modulating calcium responses to glutamate and membrane depolarization, GLP-1 may play important roles in regulating neuronal plasticity and cell survival.

Research paper thumbnail of Identification of Cysteines Involved in S-Nitrosylation, S-Glutathionylation, and Oxidation to Disulfides in Ryanodine Receptor Type 1

Journal of Biological Chemistry, 2006

The skeletal muscle Ca 2؉-release channel (ryanodine receptor type 1 (RyR1)) is a redox sensor, s... more The skeletal muscle Ca 2؉-release channel (ryanodine receptor type 1 (RyR1)) is a redox sensor, susceptible to reversible S-nitrosylation, S-glutathionylation, and disulfide oxidation. So far, Cys-3635 remains the only cysteine residue identified as functionally relevant to the redox sensing properties of the channel. We demonstrate that expression of the C3635A-RyR1 mutant in RyR1-null myotubes alters the sensitivity of the ryanodine receptor to activation by voltage, indicating that Cys-3635 is involved in voltage-gated excitation-contraction coupling. However, H 2 O 2 treatment of C3635A-RyR1 channels or wildtype RyR1, following their expression in human embryonic kidney cells, enhances [ 3 H]ryanodine binding to the same extent, suggesting that cysteines other than Cys-3635 are responsible for the oxidative enhancement of channel activity. Using a combination of Western blotting and sulfhydryl-directed fluorescent labeling, we found that two large regions of RyR1 (amino acids 1-2401 and 3120-4475), previously shown to be involved in disulfide bond formation, are also major sites of both S-nitrosylation and S-glutathionylation. Using selective isotopecoded affinity tag labeling of RyR1 and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy, we identified, out of the 100 cysteines in each RyR1 subunit, 9 that are endogenously modified (Cys-36, Cys-315, Cys-811, Cys-906, Cys-1591, Cys-2326, Cys-2363, Cys-3193, and Cys-3635) and another 3 residues that were only modified with exogenous redox agents (Cys-253, Cys-1040, and Cys-1303). We also identified the types of redox modification each of these cysteines can undergo. In summary, we have identified a discrete subset of cysteines that are likely to be involved in the functional response of RyR1 to different redox modifications (S-nitrosylation, S-glutathionylation, and oxidation to disulfides). Ca 2ϩ-release channels, also known as ryanodine receptors (RyRs), 2 play crucial roles in several cellular Ca 2ϩ-signaling pathways. These channels contribute to muscle contraction, secretion, synaptic plasticity and learning, fecundation, and apoptosis. Consistent with these important roles in cell signaling, RyRs are tightly regulated by a variety of ions and small molecules, protein-protein interactions, and post-translational modifications (for recent reviews see Refs. 1-3). RyRs, homotetramers with subunits that are Ͼ5000 amino acids, are the largest integral membrane proteins reported to date (ϳ2.3 MDa). In rabbit skeletal muscle, each subunit of the type 1 RyR (RyR1; Swiss Prot accession P11716) is comprised of 5037 amino acid residues, of which 100 are cysteines (4). Sulfhydryl reagents, however, modify only a few of these cysteines at physiological pH, which are known as the "hyper-reactive" cysteines (5). Modification of these hyper-reactive cysteine residues has marked effects on RyR1 channel open probability. RyR1 activity is enhanced in vitro by molecular oxygen (O 2), superoxide anion (O 2 .), hydrogen peroxide (H 2 O 2), hydroxyl

Research paper thumbnail of Do apoptotic mechanisms regulate synaptic plasticity and growth-cone motility?

Neuromolecular Medicine, 2002

Signals between neurons are transduced primarily by receptors, and second messenger and kinase ca... more Signals between neurons are transduced primarily by receptors, and second messenger and kinase cascades, located in pre- and postsynaptic terminals. Such synaptic signaling pathways include those activated by neurotransmitters, cytokines, neurotrophic factors, and cell-adhesion molecules. Many of these signaling systems are also localized in the growth cones of axons and dendrites, where they control pathfinding and synaptogenesis during development. Although