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Remodeling Anaplastic Thyroid Cancer's Aggressive Profile And Metabolic Signature By Natural Alkaloid Berberine, Tara Elizabeth Jarboe Mar 2024

Remodeling Anaplastic Thyroid Cancer's Aggressive Profile And Metabolic Signature By Natural Alkaloid Berberine, Tara Elizabeth Jarboe

NYMC Student Theses and Dissertations

Anaplastic thyroid cancer is a rare, fatal cancer with a five-year survival of 4%. Universally diagnosed at stage IV, anaplastic thyroid cancer is characterized by its lack of differentiation, rapid proliferative rate, highly inflammatory tumor microenvironment, and metabolic dysregulation. Refractory to all established therapies, anaplastic thyroid cancer requires a novel therapeutic approach that targets all of these drivers of anaplastic thyroid cancer carcinogenesis. We propose natural alkaloid berberine as a therapeutic with multitarget efficacy to alter mitochondrial metabolism and reprogram anaplastic thyroid cancer’s aggressive phenotype. Our in vitro model uses monocyte cell line U937, anaplastic thyroid cancer cell lines T238 …


Nrh:Quinone Oxidoreductase 2 (Nqo2) And Glutaminase (Gls) Both Play A Role In Large Extracellular Vesicles (Lev) Formation In Preclinical Lncap-C4-2b Prostate Cancer Model Of Progressive Metastasis, Thambi Dorai, Ankeeta Shah, Faith Summers, Rajamma Mathew, Jing Huang, Tze-Chen Hsieh, Joseph M. Wu Nov 2018

Nrh:Quinone Oxidoreductase 2 (Nqo2) And Glutaminase (Gls) Both Play A Role In Large Extracellular Vesicles (Lev) Formation In Preclinical Lncap-C4-2b Prostate Cancer Model Of Progressive Metastasis, Thambi Dorai, Ankeeta Shah, Faith Summers, Rajamma Mathew, Jing Huang, Tze-Chen Hsieh, Joseph M. Wu

NYMC Faculty Publications

In the course of studies aimed at the role of oxidative stress in the development of metastatic potential in the LNCaP-C4-2B prostate cancer progression model system, we found a relative decrease in the level of expression of the cytoplasmic nicotinamide riboside: quinone oxidoreductase (NQO2) and an increase in the oxidative stress in C4-2B cells compared to that in LNCaP or its derivatives C4 and C4-2. It was also found that C4-2B cells specifically shed large extracellular vesicles (LEVs) suggesting that these LEVs and their cargo could participate in the establishment of the osseous metastases. The level of expression of caveolin-1 …


Anti-Tumor Activity Of Phenoxybenzamine And Its Inhibition Of Histone Deacetylases, Mario A. Inchiosa Jun 2018

Anti-Tumor Activity Of Phenoxybenzamine And Its Inhibition Of Histone Deacetylases, Mario A. Inchiosa

NYMC Faculty Publications

The principal finding from this study was the recognition that the α-adrenergic antagonist, phenoxybenzamine, possesses histone deacetylase inhibitory activity. Phenoxybenzamine is approved by the United States Food and Drug Administration for the treatment of hypertensive crises associated with tumors of the adrenal medulla, pheochromocytomas. It has several "off label" indications relative to its capacity to relax vascular smooth muscle and smooth muscle of the urogenital tract. The drug also has a long history of apparent efficacy in ameliorating, and perhaps reversing, the severe symptoms of neuropathic pain syndromes. Our interest in this feature of the drug relates to the fact …


Application Of Open-Access Databases To Determine Functional Connectivity Between Resveratrol-Binding Protein Qr2 And Colorectal Carcinoma, Barbara B. Doonan, Evelien Schaafsma, John T. Pinto, Joseph M. Wu, Tze-Chen Hsieh Aug 2017

Application Of Open-Access Databases To Determine Functional Connectivity Between Resveratrol-Binding Protein Qr2 And Colorectal Carcinoma, Barbara B. Doonan, Evelien Schaafsma, John T. Pinto, Joseph M. Wu, Tze-Chen Hsieh

NYMC Faculty Publications

Colorectal cancer (CRC) is a major cause of cancer-associated deaths worldwide. Recently, oral administration of resveratrol (trans-3,5,4'-trihydroxystilbene) has been reported to significantly reduce tumor proliferation in colorectal cancer patients, however, with little specific information on functional connections. The pathogenesis and development of colorectal cancer is a multistep process that can be categorized using three phenotypic pathways, respectively, chromosome instability (CIN), microsatellite instability (MSI), and CpG island methylator (CIMP). Targets of resveratrol, including a high-affinity binding protein, quinone reductase 2 (QR2), have been identified with little information on disease association. We hypothesize that the relationship between resveratrol and different CRC etiologies …


Syk Inhibitors In Clinical Development For Hematological Malignancies, Delong Liu, Aleksandra Mamorska-Dyga Jul 2017

Syk Inhibitors In Clinical Development For Hematological Malignancies, Delong Liu, Aleksandra Mamorska-Dyga

NYMC Faculty Publications

Spleen tyrosine kinase (Syk) is a cytosolic non-receptor protein tyrosine kinase (PTK) and is mainly expressed in hematopoietic cells. Syk was recognized as a critical element in the B-cell receptor signaling pathway. Syk is also a key component in signal transduction from other immune receptors like Fc receptors and adhesion receptors. Several oral Syk inhibitors including fostamatinib (R788), entospletinib (GS-9973), cerdulatinib (PRT062070), and TAK-659 are being assessed in clinical trials. The second generation compound, entospletinib, showed promising results in clinical trials against B-cell malignancies, mainly chronic lymphoid leukemia. Syk inhibitors are being evaluated in combination regimens in multiple malignancies.


Regulation And Modulation Of Human Dna Polymerase Δ Activity And Function, Marietta Y W T Lee, Xiaoxiao Wang, Sufang Zhang, Zhongtao Zhang, Ernest Y C Lee Jul 2017

Regulation And Modulation Of Human Dna Polymerase Δ Activity And Function, Marietta Y W T Lee, Xiaoxiao Wang, Sufang Zhang, Zhongtao Zhang, Ernest Y C Lee

NYMC Faculty Publications

This review focuses on the regulation and modulation of human DNA polymerase δ (Pol δ). The emphasis is on the mechanisms that regulate the activity and properties of Pol δ in DNA repair and replication. The areas covered are the degradation of the p12 subunit of Pol δ, which converts it from a heterotetramer (Pol δ4) to a heterotrimer (Pol δ3), in response to DNA damage and also during the cell cycle. The biochemical mechanisms that lead to degradation of p12 are reviewed, as well as the properties of Pol δ4 and Pol δ3 that provide insights into their functions …


Gene 33/Mig6 Regulates Apoptosis And The Dna Damage Response Through Independent Mechanisms, Cen Li, Soyoung Park, Leonard M. Eisenberg, Hong Zhao, Zbigniew Darzynkiewicz, Dazhong Xu Mar 2017

Gene 33/Mig6 Regulates Apoptosis And The Dna Damage Response Through Independent Mechanisms, Cen Li, Soyoung Park, Leonard M. Eisenberg, Hong Zhao, Zbigniew Darzynkiewicz, Dazhong Xu

NYMC Faculty Posters

Gene 33 (Mig6, ERRFI1) is an inducible adaptor/scaffold protein whose expression can be induced by both stress and mitogenic signals. It contains multiple domains for protein-protein interaction and is involved in a broad spectrum of cellular functions. Gene 33 promotes apoptosis in a cell type-dependent manner. A recent study has linked Gene 33 to the DNA damage response (DDR) induced by hexavalent chromium [Cr(VI)]. Here we show that Gene 33 induces apoptosis via both c-Abl/p73 and EGFR/AKT-dependent pathways in lung epithelial and lung carcinoma cells. Ectopic expression of Gene 33 also triggers DDR in an ATM-dependent fashion and through pathways …


Role Of Inflammation In 20-Hete Regulation Of Ischemia-Induced Angiogenesis, Elizabeth Berry, Rachel John, Samantha Tang, Austin M. Guo Mar 2017

Role Of Inflammation In 20-Hete Regulation Of Ischemia-Induced Angiogenesis, Elizabeth Berry, Rachel John, Samantha Tang, Austin M. Guo

NYMC Faculty Posters

Objective: 20-Hydroxyeicosatetraenoic acid (20-HETE), an important bioactive lipid metabolite, has recently been identified to be a novel contributor of angiogenesis secondary to ischemia. Moreover, an inflammatory response is required for the initiation of ischemic angiogenesis, in response to ischemic tissue injury. The goal of this study is to investigate the role of inflammation in 20-HETE regulation of ischemia-induced angiogenesis.

Methods: We first established a mouse hind limb ischemia model for immunocompetent Balb/C mice and immunodeficient NOD-SCID mice by femoral artery ligation. Groups of Balb/C and NOD-SCID mice were administered a 20-HETE synthesis inhibitor, DDMS, or saline as a solvent control. …


Pdip46 Is Involved In Replication Timing Control, Hsiao H. Chao, Hong Zhao, Sufang Zhang Mar 2017

Pdip46 Is Involved In Replication Timing Control, Hsiao H. Chao, Hong Zhao, Sufang Zhang

NYMC Faculty Posters

No abstract provided.


Pnaktide Attenuates Steatohepatitis And Atherosclerosis By Blocking Na/K-Atpase/Ros Amplification In C57bi6 And Apoe Knockout Mice Fed A Western Diet, Komal Sodhi, K Srikanthan, P Goguet-Rubio, A Nichols, A Mallick, A Nawab, R Martin, P Shah, M Chaudhry, S Sigdel, M El-Hamdani, J Liu, Z Xie, Nader Abraham, J Shapiro Mar 2017

Pnaktide Attenuates Steatohepatitis And Atherosclerosis By Blocking Na/K-Atpase/Ros Amplification In C57bi6 And Apoe Knockout Mice Fed A Western Diet, Komal Sodhi, K Srikanthan, P Goguet-Rubio, A Nichols, A Mallick, A Nawab, R Martin, P Shah, M Chaudhry, S Sigdel, M El-Hamdani, J Liu, Z Xie, Nader Abraham, J Shapiro

NYMC Faculty Publications

We have previously reported that the alpha1 subunit of sodium potassium adenosine triphosphatase (Na/K-ATPase), acts as a receptor and an amplifier for reactive oxygen species, in addition to its distinct pumping function. On this background, we speculated that blockade of Na/K-ATPase-induced ROS amplification with a specific peptide, pNaKtide, might attenuate the development of steatohepatitis. To test this hypothesis, pNaKtide was administered to a murine model of NASH: the C57Bl6 mouse fed a "western" diet containing high amounts of fat and fructose. The administration of pNaKtide reduced obesity as well as hepatic steatosis, inflammation and fibrosis. Of interest, we also noted …


Maysin And Its Flavonoid Derivative From Centipedegrass Attenuates Amyloid Plaques By Inducting Humoral Immune Response With Th2 Skewed Cytokine Response In The Tg (Appswe, Ps1de9) Alzheimer's Mouse Model, Yuno Song, Hong-Duck Kim, Min-Kwon Lee, Il-Hwa Hong, Chung-Kil Won, Seung Sik Lee, Jae-Hyeon Cho Jan 2017

Maysin And Its Flavonoid Derivative From Centipedegrass Attenuates Amyloid Plaques By Inducting Humoral Immune Response With Th2 Skewed Cytokine Response In The Tg (Appswe, Ps1de9) Alzheimer's Mouse Model, Yuno Song, Hong-Duck Kim, Min-Kwon Lee, Il-Hwa Hong, Chung-Kil Won, Seung Sik Lee, Jae-Hyeon Cho

NYMC Faculty Publications

Alzheimer's disease (AD) is a slow, progressive neurodegenerative disease and the most common type of dementia in the elderly. The etiology of AD and its underlying mechanism are still not clear. In a previous study, we found that an ethyl acetate extract of Centipedegrass (CG) (i.e., EA-CG) contained 4 types of Maysin derivatives, including Luteolin, Isoorientin, Rhamnosylisoorientin, and Derhamnosylmaysin, and showed protective effects against Amyloid beta (Aβ) by inhibiting oligomeric Aβ in cellular and in vitro models. Here, we examined the preventative effects of EA-CG treatment on the Aβ burden in the Tg (Mo/Hu APPswe PS1dE9) AD mouse model. We …


221 Newborn-Screened Neonates With Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency: Findings From The Inborn Errors Of Metabolism Collaborative, K Bentler, S Zhai, S Elsbecker, G Arnold, B Burton, J Vockley, C Cameron, S Hiner, M Edick, S Berry, J Thomas, M Dodge, R Singh, S Lakshman, David Kronn, Inborn Errors Of Metabolism Collaborative Sep 2016

221 Newborn-Screened Neonates With Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency: Findings From The Inborn Errors Of Metabolism Collaborative, K Bentler, S Zhai, S Elsbecker, G Arnold, B Burton, J Vockley, C Cameron, S Hiner, M Edick, S Berry, J Thomas, M Dodge, R Singh, S Lakshman, David Kronn, Inborn Errors Of Metabolism Collaborative

NYMC Faculty Publications

Introduction: There is limited understanding of relationships between genotype, phenotype and other conditions contributing to health in neonates with medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) identified through newborn screening. Methods: Retrospective analysis of comprehensive data from a cohort of 221 newborn-screened subjects identified as affected with MCADD in the Inborn Errors of Metabolism-Information System (IBEM-IS), a long term follow-up database of the Inborn Errors of Metabolism Collaborative, was performed. Results: The average age at notification of first newborn screen results to primary care or metabolic providers was 7.45 days. The average octanoylcamitine (C8) value on first newborn screen was 11.2 …


Sweetening Of Glutamine Metabolism In Cancer Cells By Rho Gtpases Through Convergence Of Multiple Oncogenic Signaling Pathways, Thambi Dorai, John T. Pinto, Arthur J. L. Cooper Aug 2016

Sweetening Of Glutamine Metabolism In Cancer Cells By Rho Gtpases Through Convergence Of Multiple Oncogenic Signaling Pathways, Thambi Dorai, John T. Pinto, Arthur J. L. Cooper

NYMC Faculty Publications

Comment on: Lukey MJ, Greene KS, Erickson JW, et al. The oncogenic transcription factor c-Jun regulates glutaminase expression and sensitizes cells to glutaminase-targeted therapy. Nat Commun 2016;7:11321.


Postprandial Paraoxonase 1 Activity Following Consumption Of Recommended Amounts Of Mixed Meals In Healthy Males, Noriko Kameyama, Chizuko Maruyama, Kazuhiko Kotani, Russell Caccavello, Alejandro Gugliucci, Sadako Matsui, Taro Maruyama Jan 2016

Postprandial Paraoxonase 1 Activity Following Consumption Of Recommended Amounts Of Mixed Meals In Healthy Males, Noriko Kameyama, Chizuko Maruyama, Kazuhiko Kotani, Russell Caccavello, Alejandro Gugliucci, Sadako Matsui, Taro Maruyama

Faculty Publications & Research of the TUC College of Osteopathic Medicine

Aim: Postprandial lipid level increases induce oxidative stress, which is involved in atherogenesis. The antioxidant properties of paraoxonase 1 (PON1) have attracted attention. However, changes in postprandial PON1 levels differ across prior studies, and changes in PON1 lactonase activity, potentially relevant to PON1 physiology, after the consumption of ordinary meals are unknown. Herein we evaluated postprandial serum lipid levels and PON1 changes following mixed-meal consumption of the amounts recommended for ordinary meals.
Methods: Nine healthy male volunteers consumed three different meals in a randomized cross-over design. The test meals were as follows: S, white rice; SMF, S with …


Artificial Sweeteners And Weight Gain: Fighting Or Feeding The Obesity Epidemic?, Shanna Frisch Jan 2016

Artificial Sweeteners And Weight Gain: Fighting Or Feeding The Obesity Epidemic?, Shanna Frisch

The Science Journal of the Lander College of Arts and Sciences

Our world has developed an obsession with weight control and, as a result, has begun replacing high calorie foods with low-fat and non-caloric substitutes. Artificial sweeteners are a widely used solution to this growing problem. Though the intention when using artificial sweeteners is to lose weight, studies have shown that the opposite sometimes occurs. Researchers attempt to explain this surprising phenomenon with multiple hypotheses. Lack of appetite suppression and reward response may cause individuals to search for more food and to consume more calories. Artificial sweeteners can also have negative affects on biological mechanisms such as resting metabolic rate, as …


Orexin Receptor Activation Generates Gamma Band Input To Cholinergic And Serotonergic Arousal System Neurons And Drives An Intrinsic Ca(2+)-Dependent Resonance In Ldt And Ppt Cholinergic Neurons, Masaru Ishibashi, Iryna Gumenchuk, Bryan Kang, Catherine Steger, Elizabeth Lynn, Nancy Molina, Leonard M. Eisenberg, Christopher S. Leonard Jun 2015

Orexin Receptor Activation Generates Gamma Band Input To Cholinergic And Serotonergic Arousal System Neurons And Drives An Intrinsic Ca(2+)-Dependent Resonance In Ldt And Ppt Cholinergic Neurons, Masaru Ishibashi, Iryna Gumenchuk, Bryan Kang, Catherine Steger, Elizabeth Lynn, Nancy Molina, Leonard M. Eisenberg, Christopher S. Leonard

NYMC Faculty Publications

A hallmark of the waking state is a shift in EEG power to higher frequencies with epochs of synchronized intracortical gamma activity (30-60 Hz) - a process associated with high-level cognitive functions. The ascending arousal system, including cholinergic laterodorsal (LDT) and pedunculopontine (PPT) tegmental neurons and serotonergic dorsal raphe (DR) neurons, promotes this state. Recently, this system has been proposed as a gamma wave generator, in part, because some neurons produce high-threshold, Ca(2+)-dependent oscillations at gamma frequencies. However, it is not known whether arousal-related inputs to these neurons generate such oscillations, or whether such oscillations are ever transmitted to neuronal …


A Microrna-1280/Jag2 Network Comprises A Novel Biological Target In High-Risk Medulloblastoma, Fengfei Wang, Marc Remke, Tze-Chen Hsieh, Lizi Wu, Cynthia Hawkins, Joseph M. Wu, Erxi Wu Dec 2014

A Microrna-1280/Jag2 Network Comprises A Novel Biological Target In High-Risk Medulloblastoma, Fengfei Wang, Marc Remke, Tze-Chen Hsieh, Lizi Wu, Cynthia Hawkins, Joseph M. Wu, Erxi Wu

NYMC Faculty Publications

Over-expression of PDGF receptors (PDGFRs) has been previously implicated in high-risk medulloblastoma (MB) pathogenesis. However, the exact biological functions of PDGFRα and PDGFRβ signaling in MB biology remain poorly understood. Here, we report the subgroup specific expression of PDGFRα and PDGFRβ and their associated biological pathways in MB tumors. c-MYC, a downstream target of PDGFRβ but not PDGFRα, is involved in PDGFRβ signaling associated with cell proliferation, cell death, and invasion. Concurrent inhibition of PDGFRβ and c-MYC blocks MB cell proliferation and migration synergistically. Integrated analysis of miRNA and miRNA targets regulated by both PDGFRβ and c-MYC reveals that increased …


Hydroxamic Acid-Based Histone Deacetylase (Hdac) Inhibitors Can Mediate Neuroprotection Independent Of Hdac Inhibition, Sama Sleiman, Yan-Ling Zhang, Jennifer Gale, Manuela Basso, Giovanni Coppola, John T. Pinto, Rajiv Ratan Oct 2014

Hydroxamic Acid-Based Histone Deacetylase (Hdac) Inhibitors Can Mediate Neuroprotection Independent Of Hdac Inhibition, Sama Sleiman, Yan-Ling Zhang, Jennifer Gale, Manuela Basso, Giovanni Coppola, John T. Pinto, Rajiv Ratan

NYMC Faculty Publications

Histone deacetylase (HDAC) inhibition improves function and extends survival in rodent models of a host of neurological conditions, including stroke, and neurodegenerative diseases. Our understanding, however, of the contribution of individual HDAC isoforms to neuronal death is limited. In this study, we used selective chemical probes to assess the individual roles of the Class I HDAC isoforms in protecting Mus musculus primary cortical neurons from oxidative death. We demonstrated that the selective HDAC8 inhibitor PCI-34051 is a potent neuroprotective agent; and by taking advantage of both pharmacological and genetic tools, we established that HDAC8 is not critically involved in PCI-34051's …


Hdac8 And Stat3 Repress Bmf Gene Activity In Colon Cancer Cells, Y Kang, Hui Nian, P Rajendran, W Dashwood, John T. Pinto, E Ho, R Dashwood Oct 2014

Hdac8 And Stat3 Repress Bmf Gene Activity In Colon Cancer Cells, Y Kang, Hui Nian, P Rajendran, W Dashwood, John T. Pinto, E Ho, R Dashwood

NYMC Faculty Publications

Histone deacetylase (HDAC) inhibitors are undergoing clinical trials as anticancer agents, but some exhibit resistance mechanisms linked to anti-apoptotic Bcl-2 functions, such as BH3-only protein silencing. HDAC inhibitors that reactivate BH3-only family members might offer an improved therapeutic approach. We show here that a novel seleno-α-keto acid triggers global histone acetylation in human colon cancer cells and activates apoptosis in a p21-independent manner. Profiling of multiple survival factors identified a critical role for the BH3-only member Bcl-2-modifying factor (Bmf). On the corresponding BMF gene promoter, loss of HDAC8 was associated with signal transducer and activator of transcription 3 (STAT3)/specificity protein …


Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard Dec 2013

Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard

NYMC Faculty Publications

Orexin neuropeptides influence multiple homeostatic functions and play an essential role in the expression of normal sleep-wake behavior. While their two known receptors (OX1 and OX2) are targets for novel pharmacotherapeutics, the actions mediated by each receptor remain largely unexplored. Using brain slices from mice constitutively lacking either receptor, we used whole-cell and Ca(2+) imaging methods to delineate the cellular actions of each receptor within cholinergic [laterodorsal tegmental nucleus (LDT)] and monoaminergic [dorsal raphe (DR) and locus coeruleus (LC)] brainstem nuclei-where orexins promote arousal and suppress REM sleep. In slices from OX(-/-) 2 mice, orexin-A (300 nM) elicited wild-type responses …


What Is New For An Old Molecule? Systematic Review And Recommendations On The Use Of Resveratrol, Ole Vang, Nihal Ahmad, Karen Brown, Anna Csiszar, Thomas Szekeres, Thomas Walle, Joseph M. Wu Jun 2011

What Is New For An Old Molecule? Systematic Review And Recommendations On The Use Of Resveratrol, Ole Vang, Nihal Ahmad, Karen Brown, Anna Csiszar, Thomas Szekeres, Thomas Walle, Joseph M. Wu

NYMC Faculty Publications

BACKGROUND: Resveratrol is a natural compound suggested to have beneficial health effects. However, people are consuming resveratrol for this reason without having the adequate scientific evidence for its effects in humans. Therefore, scientific valid recommendations concerning the human intake of resveratrol based on available published scientific data are necessary. Such recommendations were formulated after the Resveratrol 2010 conference, held in September 2010 in Helsingør, Denmark.

METHODOLOGY: Literature search in databases as PUBMED and ISI Web of Science in combination with manual search was used to answer the following five questions: (1)Can resveratrol be recommended in the prevention or treatment of …


Mechanisms Of Oxidant Generation By Catalase, Diane E. Heck, Michael Shakarjian, Hong-Duck Kim, Jeffrey Laskin, Anna M. Vetrano Aug 2010

Mechanisms Of Oxidant Generation By Catalase, Diane E. Heck, Michael Shakarjian, Hong-Duck Kim, Jeffrey Laskin, Anna M. Vetrano

NYMC Faculty Publications

The enzyme catalase converts solar radiation into reactive oxidant species (ROS). In this study, we report that several bacterial catalases (hydroperoxidases, HP), including Escherichia coli HP-I and HP-II also generate reactive oxidants in response to ultraviolet B light (UVB). HP-I and HP-II are identical except for the presence of NADPH. We found that only one of the catalases, HPI, produces oxidants in response to UVB light, indicating a potential role for the nucleotide in ROS production. This prompts us to speculate that NADPH may act as a cofactor regulating ROS generation by mammalian catalases. Structural analysis of the NADPH domains …


Atf4 Is An Oxidative Stress–Inducible, Prodeath Transcription Factor In Neurons In Vitro And In Vivo, Philipp Lange, Juan Chavez, John T. Pinto, Giovanni Coppola, Chiao-Wang Sun, Tim Townes, Rajiv Ratan May 2008

Atf4 Is An Oxidative Stress–Inducible, Prodeath Transcription Factor In Neurons In Vitro And In Vivo, Philipp Lange, Juan Chavez, John T. Pinto, Giovanni Coppola, Chiao-Wang Sun, Tim Townes, Rajiv Ratan

NYMC Faculty Publications

Oxidative stress is pathogenic in neurological diseases, including stroke. The identity of oxidative stress-inducible transcription factors and their role in propagating the death cascade are not well known. In an in vitro model of oxidative stress, the expression of the bZip transcription factor activating transcription factor 4 (ATF4) was induced by glutathione depletion and localized to the promoter of a putative death gene in neurons. Germline deletion of ATF4 resulted in a profound reduction in oxidative stress-induced gene expression and resistance to oxidative death. In neurons, ATF4 modulates an early, upstream event in the death pathway, as resistance to oxidative …


Specific Functions Of Synaptically Localized Potassium Channels In Synaptic Transmission At The Neocortical Gabaergic Fast-Spiking Cell Synapse, Ethan Goldberg, Shigeo Watanabe, Su Ying Chang, Rolf Joho, Z Josh Huang, Christopher S. Leonard, Bernardo Rudy May 2005

Specific Functions Of Synaptically Localized Potassium Channels In Synaptic Transmission At The Neocortical Gabaergic Fast-Spiking Cell Synapse, Ethan Goldberg, Shigeo Watanabe, Su Ying Chang, Rolf Joho, Z Josh Huang, Christopher S. Leonard, Bernardo Rudy

NYMC Faculty Publications

Potassium (K+) channel subunits of the Kv3 subfamily (Kv3.1-Kv3.4) display a positively shifted voltage dependence of activation and fast activation/deactivation kinetics when compared with other voltage-gated K+ channels, features that confer on Kv3 channels the ability to accelerate the repolarization of the action potential (AP) efficiently and specifically. In the cortex, the Kv3.1 and Kv3.2 proteins are expressed prominently in a subset of GABAergic interneurons known as fast-spiking (FS) cells and in fact are a significant determinant of the fast-spiking discharge pattern. However, in addition to expression at FS cell somata, Kv3.1 and Kv3.2 proteins also are expressed prominently at …


Direct And Indirect Excitation Of Laterodorsal Tegmental Neurons By Hypocretin/Orexin Peptides: Implications For Wakefulness And Narcolepsy, Sophie Burlet, Christopher Tyler, Christopher S. Leonard Apr 2002

Direct And Indirect Excitation Of Laterodorsal Tegmental Neurons By Hypocretin/Orexin Peptides: Implications For Wakefulness And Narcolepsy, Sophie Burlet, Christopher Tyler, Christopher S. Leonard

NYMC Faculty Publications

Compelling evidence links the recently discovered hypothalamic peptides Hypocretin/Orexin (Hcrt/Orx) to rapid eye movement sleep (REM) control and the sleep disorder narcolepsy, yet how they influence sleep-related systems is not well understood. We investigated the action of Hcrt/Orx on mesopontine cholinergic (MPCh) neurons of the laterodorsal tegmental nucleus (LDT), a target group whose function is altered in canine narcolepsy and appears pivotal for normal REM and wakefulness. Extracellular recordings from mouse brainstem slices revealed that Hcrt/Orx evoked prolonged firing of LDT neurons. Whole-cell recordings revealed that Hcrt/Orx had actions on both presynaptic neurons and at postsynaptic sites. Hcrt/Orx produced an …


Impaired Fast-Spiking, Suppressed Cortical Inhibition, And Increased Susceptibility To Seizures In Mice Lacking Kv3.2 K+ Channel Proteins, David Lau, Eleazar Vega-Saenz De Miera, Diego Contreras, Alan Chow, Richard Paylor, Christopher S. Leonard, Bernardo Rudy Dec 2000

Impaired Fast-Spiking, Suppressed Cortical Inhibition, And Increased Susceptibility To Seizures In Mice Lacking Kv3.2 K+ Channel Proteins, David Lau, Eleazar Vega-Saenz De Miera, Diego Contreras, Alan Chow, Richard Paylor, Christopher S. Leonard, Bernardo Rudy

NYMC Faculty Publications

Voltage-gated K(+) channels of the Kv3 subfamily have unusual electrophysiological properties, including activation at very depolarized voltages (positive to -10 mV) and very fast deactivation rates, suggesting special roles in neuronal excitability. In the brain, Kv3 channels are prominently expressed in select neuronal populations, which include fast-spiking (FS) GABAergic interneurons of the neocortex, hippocampus, and caudate, as well as other high-frequency firing neurons. Although evidence points to a key role in high-frequency firing, a definitive understanding of the function of these channels has been hampered by a lack of selective pharmacological tools. We therefore generated mouse lines in which one …