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Tsytsarev V, Sopova JV, Leonova EI, Inyushin M, Markina AA, Chirinskaite AV, Volnova AB. Neurophotonic methods in approach to in vivo animal epileptic models: Advantages and limitations. Epilepsia 2024; 65:600-614. [PMID: 38115808 PMCID: PMC10948300 DOI: 10.1111/epi.17870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Neurophotonic technology is a rapidly growing group of techniques that are based on the interactions of light with natural or genetically modified cells of the neural system. New optical technologies make it possible to considerably extend the tools of neurophysiological research, from the visualization of functional activity changes to control of brain tissue excitability. This opens new perspectives for studying the mechanisms underlying the development of human neurological diseases. Epilepsy is one of the most common brain disorders; it is characterized by recurrent seizures and affects >1% of the world's population. However, how seizures occur, spread, and terminate in a healthy brain is still unclear. Therefore, it is extremely important to develop appropriate models to accurately explore the causal relationship of epileptic activity. The use of neurophotonic technologies in epilepsy research falls into two broad categories: the visualization of neural epileptic activity, and the direct optical influence on neurons to induce or suppress epileptic activity. An optogenetic variant of the classical kindling model of epileptic seizures, in which activatable cells are genetically defined, is called optokindling. Research is also underway concerning the application of neurophotonic techniques for suppressing epileptic activity, aiming to bring these methods into clinical practice. This review aims to systematize and describe new approaches that use combinations of different neurophotonic methods to work with in vivo models of epilepsy. These approaches overcome many of the shortcomings associated with classical animal models of epilepsy and thus increase the effectiveness of developing new diagnostic methods and antiepileptic therapy.
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Affiliation(s)
- Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Neurobiology 20 Penn St, HSF-2, 21201 MD, Baltimore, United States
| | - Julia V. Sopova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena I. Leonova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA
| | - Alisa A. Markina
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
| | - Angelina V. Chirinskaite
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anna B. Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
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2
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De Freitas-Suarez A, Espinosa-Ponce N, Alvarez-Roger N, Cabrera-Suarez AI, Jiménez-Jordán G, Vega-Roman R, Inyushin M, Alves JM. An Integrative Approach to the Current Treatment of HIV-Associated Neurocognitive Disorders and the Implementation of Leukemia Inhibitor Factor as a Mediator of Neurocognitive Preservation. Life (Basel) 2023; 13:2194. [PMID: 38004334 PMCID: PMC10672511 DOI: 10.3390/life13112194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/23/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
HIV-associated neurocognitive disorders (HANDs) continue to impact patients despite antiretroviral therapy. A combination of antiretroviral therapies can diminish the HIV viral load to near undetectable levels, but fails to preserve neurocognitive integrity. The cytokine leukemia inhibitory factor (LIF) has shown neuroprotective properties that could mitigate neurodegeneration in HANDs. The LIF promotes neurogenesis, neural cell differentiation, and survival. Combination antiretroviral therapy reduces severe forms of HANDs, but neurocognitive impairment persists; additionally, some antiretrovirals have additional adverse neurotoxic effects. The LIF counteracts neurotoxic viral proteins and limits neural cell damage in models of neuroinflammation. Adding the LIF as an adjuvant therapy to enhance neuroprotection merits further research for managing HANDs. The successful implementation of the LIF to current therapies would contribute to achieving a better quality of life for the affected population.
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Affiliation(s)
| | - Natalia Espinosa-Ponce
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, Bayamón, PR 00960, USA; (N.E.-P.); (A.I.C.-S.)
| | - Natalia Alvarez-Roger
- Department of Medicine, Universidad Central del Caribe, Bayamón, PR 00956, USA; (N.A.-R.); (R.V.-R.)
| | - Arianna Iris Cabrera-Suarez
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, Bayamón, PR 00960, USA; (N.E.-P.); (A.I.C.-S.)
| | | | - Rocio Vega-Roman
- Department of Medicine, Universidad Central del Caribe, Bayamón, PR 00956, USA; (N.A.-R.); (R.V.-R.)
| | - Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe School of Medicine, Bayamón, PR 00960, USA;
| | - Janaina M. Alves
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, Bayamón, PR 00960, USA; (N.E.-P.); (A.I.C.-S.)
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Ortiz Rivera J, Velez Crespo G, Inyushin M, Kucheryavykh Y, Kucheryavykh L. Pyk2/FAK Signaling Is Upregulated in Recurrent Glioblastoma Tumors in a C57BL/6/GL261 Glioma Implantation Model. Int J Mol Sci 2023; 24:13467. [PMID: 37686276 PMCID: PMC10487692 DOI: 10.3390/ijms241713467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The majority of glioblastomas (GBMs) recur shortly after tumor resection and recurrent tumors differ significantly from newly diagnosed GBMs, phenotypically and genetically. In this study, using a Gl261-C57Bl/6 mouse glioma implantation model, we identified significant upregulation of proline-rich tyrosine kinase Pyk2 and focal adhesion kinase (FAK) phosphorylation levels-pPyk2 (579/580) and pFAK (925)-without significant modifications in total Pyk2 and FAK protein expression in tumors regrown after surgical resection, compared with primary implanted tumors. Previously, we demonstrated that Pyk2 and FAK are involved in the regulation of tumor cell invasion and proliferation and are associated with reduced overall survival. We hypothesized that the use of inhibitors of Pyk2/FAK in the postsurgical period may reduce the growth of recurrent tumors. Using Western blot analysis and confocal immunofluorescence approaches, we demonstrated upregulation of Cyclin D1 and the Ki67 proliferation index in tumors regrown after resection, compared with primary implanted tumors. Treatment with Pyk2/FAK inhibitor PF-562271, administered through oral gavage at 50 mg/kg daily for two weeks beginning 2 days before tumor resection, reversed Pyk2/FAK signaling upregulation in recurrent tumors, reduced tumor volume, and increased animal survival. In conclusion, the use of Pyk2/FAK inhibitors can contribute to a delay in GBM tumor regrowth after surgical resection.
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Affiliation(s)
- Jescelica Ortiz Rivera
- Department of Biochemistry, School of Medicine, Universidad Central de Caribe, Bayamon, PR 00956, USA; (G.V.C.); (M.I.); (Y.K.); (L.K.)
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Sibarov DA, Tsytsarev V, Volnova A, Vaganova AN, Alves J, Rojas L, Sanabria P, Ignashchenkova A, Savage ED, Inyushin M. Arc protein, a remnant of ancient retrovirus, forms virus-like particles, which are abundantly generated by neurons during epileptic seizures, and affects epileptic susceptibility in rodent models. Front Neurol 2023; 14:1201104. [PMID: 37483450 PMCID: PMC10361770 DOI: 10.3389/fneur.2023.1201104] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/02/2023] [Indexed: 07/25/2023] Open
Abstract
A product of the immediate early gene Arc (Activity-regulated cytoskeleton-associated protein or Arc protein) of retroviral ancestry resides in the genome of all tetrapods for millions of years and is expressed endogenously in neurons. It is a well-known protein, very important for synaptic plasticity and memory consolidation. Activity-dependent Arc expression concentrated in glutamatergic synapses affects the long-time synaptic strength of those excitatory synapses. Because it modulates excitatory-inhibitory balance in a neuronal network, the Arc gene itself was found to be related to the pathogenesis of epilepsy. General Arc knockout rodent models develop a susceptibility to epileptic seizures. Because of activity dependence, synaptic Arc protein synthesis also is affected by seizures. Interestingly, it was found that Arc protein in synapses of active neurons self-assemble in capsids of retrovirus-like particles, which can transfer genetic information between neurons, at least across neuronal synaptic boutons. Released Arc particles can be accumulated in astrocytes after seizures. It is still not known how capsid assembling and transmission timescale is affected by seizures. This scientific field is relatively novel and is experiencing swift transformation as it grapples with difficult concepts in light of evolving experimental findings. We summarize the emergent literature on the subject and also discuss the specific rodent models for studying Arc effects in epilepsy. We summarized both to clarify the possible role of Arc-related pseudo-viral particles in epileptic disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Dmitry A. Sibarov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Anastasia N. Vaganova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Janaina Alves
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Legier Rojas
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Priscila Sanabria
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | | | | | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
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Crespo GV, Ortiz J, O'Farrill EH, Vlaar CP, Inyushin M, Kucheryavykh Y, Kucheryavykh L. The Rac inhibitor HV-107 as a potential therapeutic for metastatic breast cancer. Mol Med 2023; 29:75. [PMID: 37316799 PMCID: PMC10268403 DOI: 10.1186/s10020-023-00678-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND The significant challenge in treating triple-negative breast cancer (TNBC) lies in its high rate of distant metastasis. To address this, inhibiting metastasis formation in TNBC is vital. Rac is a key player in cancer metastasis. Previously, we developed Ehop-016, a Rac inhibitor that successfully reduced tumor growth and metastasis in mice. In this study, we assessed the effectiveness of HV-107, a derivative of Ehop-016, in inhibiting TNBC metastasis at lower doses. METHODS Rho GTPases activity assays were performed with the use of GST-PAK beads and Rac, Rho, and Cdc42 GLISA. Cell viability was assessed through trypan blue exclusion and MTT assays. Cell cycle analysis was conducted using flow cytometry. To evaluate invading capabilities, transwell assays and invadopodia formation assays were performed. Metastasis formation studies were conducted using a breast cancer xenograft mouse model. RESULTS HV-107 inhibited Rac activity by 50% in MDA-MB-231 and MDA-MB-468 cells at concentrations of 250-2000 nM, leading to a 90% decrease in invasion and invadopodia activity. Concentrations of 500 nM and above caused dose-dependent reductions in cell viability, resulting in up to 20% cell death after 72 h. Concentrations exceeding 1000 nM upregulated PAK1, PAK2, FAK, Pyk2, Cdc42, and Rho signallings, while Pyk2 was downregulated at 100-500 nM. Through in vitro experiments, optimal concentrations of HV-107 ranging from 250 to 500 nM were identified, effectively inhibiting Rac activity and invasion while minimizing off-target effects. In a breast cancer xenograft model, administration of 5 mg/kg HV-107 (administered intraperitoneally, 5 days a week) reduced Rac activity by 20% in tumors and decreased metastasis by 50% in the lungs and liver. No observed toxicity was noted at the tested doses. CONCLUSION The findings indicate that HV-107 exhibits promising potential as a therapeutic medication utilizing Rac inhibition mechanisms to address metastasis formation in TNBC.
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Affiliation(s)
- Grace Velez Crespo
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico.
| | - Jescelica Ortiz
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico
| | - Eliud Hernández O'Farrill
- Department of Pharmaceutical Science, School of Pharmacy, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Cornelis P Vlaar
- Department of Biochemistry, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, Bayamón, Puerto Rico
| | - Yuriy Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico
| | - Lilia Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico
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Jang S, Chorna N, Rodríguez-Graciani KM, Inyushin M, Fossati S, Javadov S. The Effects of Amyloid-β on Metabolomic Profiles of Cardiomyocytes and Coronary Endothelial Cells. J Alzheimers Dis 2023; 93:307-319. [PMID: 36970904 DOI: 10.3233/jad-221199] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
BACKGROUND An increasing number of experimental and clinical studies show a link between Alzheimer's disease and heart diseases such as heart failure, ischemic heart disease, and atrial fibrillation. However, the mechanisms underlying the potential role of amyloid-β (Aβ) in the pathogenesis of cardiac dysfunction in Alzheimer's disease remain unknown. We have recently shown the effects of Aβ 1 - 40 and Aβ 1 - 42 on cell viability and mitochondrial function in cardiomyocytes and coronary artery endothelial cells. OBJECTIVE In this study, we investigated the effects of Aβ 1 - 40 and Aβ 1 - 42 on the metabolism of cardiomyocytes and coronary artery endothelial cells. METHODS Gas chromatography-mass spectrometry was used to analyze metabolomic profiles of cardiomyocytes and coronary artery endothelial cells treated with Aβ 1 - 40 and Aβ 1 - 42. In addition, we determined mitochondrial respiration and lipid peroxidation in these cells. RESULTS We found that the metabolism of different amino acids was affected by Aβ 1 - 42 in each cell type, whereas the fatty acid metabolism is consistently disrupted in both types of cells. Lipid peroxidation was significantly increased, whereas mitochondrial respiration was reduced in both cell types in response to Aβ 1 - 42. CONCLUSION This study revealed the disruptive effects of Aβ on lipid metabolism and mitochondria function in cardiac cells.
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Affiliation(s)
- Sehwan Jang
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, USA
| | - Nataliya Chorna
- Department of Biochemistry, University of Puerto Rico School of Medicine, San Juan, PR, USA
| | | | - Mikhail Inyushin
- Department of Physiology, School of Medicine, Universidad Central del Caribe, Bayamon, PR, USA
| | - Silvia Fossati
- Alzheimer's Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, USA
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Alves JM, Inyushin M, Tsytsarev V, Roldan-Kalil JA, Miranda-Valentin E, Maldonado-Martinez G, Ramos-Feliciano KM, Hunter-Mellado R. Adjuvant effect of dendritic cells activator Imiquimod in genetic immunization with HIV-1 p55 Gag. J Immunol Tech Infect Dis 2023; 12:330. [PMID: 37205236 PMCID: PMC10191261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dendritic cells (DC) are important antigen-presenting cells that have abilities to induce and maintain T-cell immunity, or attenuate it during hyperimmunization. Additional activation of DCs may be useful for vaccination purposes. Imiquimod is known to be a specific agonist of the Toll-like receptors (TLR7), which are located mainly on DCs. To study the effect of DC stimulation on the effectiveness of an HIV-1 p55 gag DNA vaccine in a mice model, we employed 25, 50, and 100 nM of Imiquimod as an adjuvant. Subsequently, Western blot analysis was used to quantify p55 protein production after the immunization. To characterize T-cells immune response, both the frequency of IFN-γ -secreting cells and IFN-γ and IL-4 production were measured, via an ELIspot assay and ELISA, respectively. Low concentrations of Imiquimod were found to effectively stimulate Gag production and the magnitude of the T-cell immune response, whereas higher concentrations reduced vaccination effects. Our results show that the adjuvant effects of Imiquimod depend on concentration. The use of Imiquimod may be helpful to study DC to T cell communication, including possible induction of immunotolerance.
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Affiliation(s)
- Janaina M Alves
- Universidad Central del Caribe School of Medicine, Bayamón, Puerto Rico 00960
| | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamón, Puerto Rico 00960
| | | | | | - Eric Miranda-Valentin
- University of Puerto Rico, Medical Sciences Campus School of Medicine, San Juan, Puerto Rico
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Roldan-Kalil J, Zueva L, Alves J, Tsytsarev V, Sanabria P, Inyushin M. Amount of Melanin Granules in Human Hair Defines the Absorption and Conversion to Heat of Light Energy in the Visible Spectrum. Photochem Photobiol 2022. [PMID: 36403200 DOI: 10.1111/php.13744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022]
Abstract
One of the known important functions of hair is protection from extensive sunlight. This protection is accomplished in large part due to natural hair pigmentation which is known to reflect the number of melanin granules (melanosomes) in the hair shaft, and melanin variants. Melanin takes in excessive light energy and converts it to heat in a process called absorption; heat is then dissipated into the environment as infrared radiation, thereby protecting the underlying skin. We used transmission electron microscopy (TEM) to visualize the melanosome counts in samples of human hair, and used thermal microscopy to measure the temperature changes of the samples when exposed to green and blue light lasers. In our experiments green light conversion to heat was highly correlated to the number of melanosomes, whereas blue light conversion to heat was less correlated, which may be because the reddish melanosomes it contains are less effective in absorbing energy from the blue spectrum of light. Anyway, we have shown the metals accumulation in the melanin can be easily visualized with TEM. We confirmed that the amount of melanin granules in human hair defines the conversion to heat of light energy in the visible spectrum.
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Affiliation(s)
| | - Lidia Zueva
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | - Janaina Alves
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | | | - Priscila Sanabria
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
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Zueva L, Zayas-Santiago A, Rojas L, Sanabria P, Alves J, Tsytsarev V, Inyushin M. Multilayer subwavelength gratings or sandwiches with periodic structure shape light reflection in the tapetum lucidum of taxonomically diverse vertebrate animals. J Biophotonics 2022; 15:e202200002. [PMID: 35243792 PMCID: PMC9487202 DOI: 10.1002/jbio.202200002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/09/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Eye shine in the dark has attracted many researchers to the field of eye optics, but the initial studies of subwavelength arrangements in tapetum began only with the development of electronic microscopy at the end of the 20th century. As a result of a number of studies, it was shown that the reflective properties of the tapetum are due to their specialized cellular subwavelength microstructure (photonic crystals). These properties, together with the mutual orientation of the crystals, lead to a significant increase in reflection, which, in turn, enhances the sensitivity of the eye. In addition, research confirmed that optical mechanisms of reflection in the tapetum are very similar even for widely separated species. Due to progress in the field of nano-optics, researchers now have a better understanding of the main principles of this phenomenon. In this review, we summarize electron microscopic and functional studies of tapetal structures in the main vertebrate classes. This allows data on the microstructure of the tapetum to be used to improve our understanding of the visual system.
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Affiliation(s)
- Lidia Zueva
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Legier Rojas
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Priscila Sanabria
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Janaina Alves
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
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Volnova A, Tsytsarev V, Ganina O, Vélez-Crespo GE, Alves JM, Ignashchenkova A, Inyushin M. The Anti-Epileptic Effects of Carbenoxolone In Vitro and In Vivo. Int J Mol Sci 2022; 23:ijms23020663. [PMID: 35054848 PMCID: PMC8775396 DOI: 10.3390/ijms23020663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 12/14/2022] Open
Abstract
Gap junctions (GJs) are intercellular junctions that allow the direct transfer of ions and small molecules between neighboring cells, and GJs between astrocytes play an important role in the development of various pathologies of the brain, including regulation of the pathological neuronal synchronization underlying epileptic seizures. Recently, we found that a pathological change is observed in astrocytes during the ictal and interictal phases of 4-aminopyridin (4-AP)-elicited epileptic activity in vitro, which was correlated with neuronal synchronization and extracellular epileptic electrical activity. This finding raises the question: Does this signal depend on GJs between astrocytes? In this study we investigated the effect of the GJ blocker, carbenoxolone (CBX), on epileptic activity in vitro and in vivo. Based on the results obtained, we came to the conclusion that the astrocytic syncytium formed by GJ-associated astrocytes, which is responsible for the regulation of potassium, affects the formation of epileptic activity in astrocytes in vitro and epileptic seizure onset. This effect is probably an important, but not the only, mechanism by which CBX suppresses epileptic activity. It is likely that the mechanisms of selective inhibition of GJs between astrocytes will show important translational benefits in anti-epileptic therapies.
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Affiliation(s)
- Anna Volnova
- Biological Faculty, Saint Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 St. Petersburg, Russia;
- Correspondence: (A.V.); (M.I.)
| | | | - Olga Ganina
- Nevsky Center of Scientific Collaboration, 192119 St. Petersburg, Russia;
| | - Grace E. Vélez-Crespo
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
| | - Janaina M. Alves
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
| | - Alla Ignashchenkova
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 St. Petersburg, Russia;
- Nevsky Center of Scientific Collaboration, 192119 St. Petersburg, Russia;
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
- Correspondence: (A.V.); (M.I.)
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11
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Zayas‐Santiago A, Martínez‐Montemayor MM, Colón‐Vázquez J, Ortiz‐Soto G, Cirino‐Simonet JG, Inyushin M. Accumulation of amyloid beta (Aβ) and amyloid precursor protein (APP) in tumors formed by a mouse xenograft model of inflammatory breast cancer. FEBS Open Bio 2022; 12:95-105. [PMID: 34592066 PMCID: PMC8727955 DOI: 10.1002/2211-5463.13308] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/16/2021] [Accepted: 10/29/2021] [Indexed: 02/06/2023] Open
Abstract
Accumulation of amyloid in breast cancer is a well-known phenomenon, but only immunoglobulin light-chain amyloidosis (AL) or transthyretin (TTR) amyloid had been detected in human breast tumor samples previously. We recently reported that another amyloidogenic peptide, amyloid beta (Aβ), is present in an aggregated form in animal and human high-grade gliomas and suggested that it originates systemically from the blood, possibly generated by platelets. To study whether breast cancers are also associated with these Aβ peptides and in what form, we used a nude mouse model inoculated with triple-negative inflammatory breast cancer cell (SUM-149) xenografts, which develop noticeable tumors. Immunostaining with two types of specific antibodies for Aβ identified the clear presence of Aβ peptides associated with (a) carcinoma cells and (b) extracellular aggregated amyloid (also revealed by Congo red and thioflavin S staining). Aβ peptides, in both cells and in aggregated amyloid, were distributed in clear gradients, with maximum levels near blood vessels. We detected significant presence of amyloid precursor protein (APP) in the walls of blood vessels of tumor samples, as well as in carcinoma cells. Finally, we used ELISA to confirm the presence of elevated levels of mouse-generated Aβ40 in tumors. We conclude that Aβ in inflammatory breast cancer tumors, at least in a mouse model, is always present and is concentrated near blood vessels. We also discuss here the possible pathways of Aβ accumulation in tumors and whether this phenomenon could represent the specific signature of high-grade cancers.
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Affiliation(s)
| | | | | | | | | | - Mikhail Inyushin
- Department of PhysiologyUniversidad Central del CaribeBayamónPRUSA
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12
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Inyushin M, Zayas-Santiago A, Rojas L, Kucheryavykh L. On the Role of Platelet-Generated Amyloid Beta Peptides in Certain Amyloidosis Health Complications. Front Immunol 2020; 11:571083. [PMID: 33123145 PMCID: PMC7567018 DOI: 10.3389/fimmu.2020.571083] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/15/2020] [Indexed: 12/15/2022] Open
Abstract
As do many other immunity-related blood cells, platelets release antimicrobial peptides that kill bacteria, fungi, and even certain viruses. Here we review the literature suggesting that there is a similarity between the antimicrobials released by other blood cells and the amyloid-related Aβ peptide released by platelets. Analyzing the literature, we also propose that platelet-generated Aβ amyloidosis may be more common than currently recognized. This systemic Aβ from a platelet source may participate in various forms of amyloidosis in pathologies ranging from brain cancer, glaucoma, skin Aβ accumulation, and preeclampsia to Alzheimer’s disease and late-stage Parkinson’s disease. We also discuss the advantages and disadvantages of specific animal models for studying platelet-related Aβ. This field is undergoing rapid change, as it evaluates competing ideas in the light of new experimental observations. We summarized both in order to clarify the role of platelet-generated Aβ peptides in amyloidosis-related health disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Astrid Zayas-Santiago
- Department of Pathology & Laboratory Medicine, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Legier Rojas
- Department of Physiology, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Lilia Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamon, Puerto Rico
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13
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Zayas-Santiago A, Díaz-García A, Nuñez-Rodríguez R, Inyushin M. Accumulation of amyloid beta in human glioblastomas. Clin Exp Immunol 2020; 202:325-334. [PMID: 32654112 PMCID: PMC7670151 DOI: 10.1111/cei.13493] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
Many cancer types are intrinsically associated with specific types of amyloidosis, in which amyloid is accumulated locally inside tumors or systemically. Usually, this condition relates to the hyperproduction of specific amylogenic proteins. Recently, we found that the accumulation of amyloid beta (Aβ) peptide immunofluorescence is linked to glioma cells in mouse tumors. Here we report that amyloid-specific histochemical dyes reveal amyloid accumulation in all human glioma samples. Application of two different antibodies against Aβ peptide (a polyclonal antibody against human Aβ1-42 and a monoclonal pan-specific mAb-2 antibody against Aβ) showed that the amyloid in glioma samples contains Aβ. Amyloid was linked to glioma cells expressing glial-specific fibrillary acidic protein (GFAP) and to glioma blood vessels. Astrocytes close to the glioma site and to affected vessels also accumulated Aβ. We discuss whether amyloid is produced by glioma cells or is the result of systemic production of Aβ in response to glioma development due to an innate immunity reaction. We conclude that amyloid build-up in glioma tumors is a part of the tumor environment, and may be used as a target for developing a novel class of anti-tumor drugs and as an antigen for glioma visualization.
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Affiliation(s)
- A Zayas-Santiago
- Physiology Department, Medical School, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - A Díaz-García
- Physiology Department, Medical School, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - R Nuñez-Rodríguez
- Biochemistry Department, Medical School, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - M Inyushin
- Physiology Department, Medical School, Universidad Central del Caribe, Bayamon, Puerto Rico
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14
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Zueva L, Golubeva T, Korneeva E, Resto O, Inyushin M, Khmelinskii I, Makarov V. Electron microscopy study of the central retinal fovea in Pied flycatcher: evidence of a mechanism of light energy transmission through the retina. Heliyon 2020; 6:e04146. [PMID: 32566783 PMCID: PMC7298408 DOI: 10.1016/j.heliyon.2020.e04146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/11/2020] [Accepted: 06/02/2020] [Indexed: 11/29/2022] Open
Abstract
We present unique ultrastructural data on avian retinal cells. Presently and earlier (Zueva et al., 2016) we explored distribution of intermediate filaments (IFs) in retinal cells of the Pied flycatcher (Ficedula hypoleuca, Passeriformes, Aves) in the central foveolar zone. This retinal zone only contains single and double cone photoreceptors. Previously we found that continuous IFs span Müller cells (MC) lengthwise from the retinal inner limiting membrane (ILM) layer up to the outer limiting membrane (OLM) layer. Here we describe long cylindrical bundles of IFs (IFBs) inside the cone inner segments (CIS) adjoining the cone plasma membrane, with these IFBs following along the cone lengthwise, and surrounding the cone at equal spacing one from the other. Double cones form a combined unit, wherein they are separated by their respective plasma membranes. Double cones thus have a common external ring of IFBs, surrounding both cone components. In the layer of cilia, the IFBs that continue into the cone outer segment (COS) follow on to the cone apical tip along the direction of incident light, with single IFs separating from the IFB, touching, and sometimes passing in-between the light-sensitive lamellae of the COS. These new data support our previous hypothesis on the quantum mechanism of light energy propagation through the vertebrate retina (Zueva et al., 2016, 2019).
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Affiliation(s)
- Lidia Zueva
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez pr. 44, 194223, St-Petersburg, Russia
- Universidad Central del Caribe, Bayamón, PR 00960-6032, USA
| | - Tatiana Golubeva
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119992, Moscow, Russia
| | - Elena Korneeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova str., 5a, 117485, Moscow, Russia
| | - Oscar Resto
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
| | | | - Igor Khmelinskii
- University of the Algarve, FCT, DQF and CEOT, 8005-139, Faro, Portugal
| | - Vladimir Makarov
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
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15
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Martins AH, Zayas-Santiago A, Ferrer-Acosta Y, Martinez-Jimenez SM, Zueva L, Diaz-Garcia A, Inyushin M. Accumulation of Amyloid Beta (Aβ) Peptide on Blood Vessel Walls in the Damaged Brain after Transient Middle Cerebral Artery Occlusion. Biomolecules 2019; 9:biom9080350. [PMID: 31398804 PMCID: PMC6723874 DOI: 10.3390/biom9080350] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/03/2019] [Accepted: 08/03/2019] [Indexed: 02/06/2023] Open
Abstract
It is well known that amyloid beta (Aβ) peptides are generated in blood vessels, released into the brain during thrombosis, and temporarily accumulate in this organ after injury. Here we demonstrate that 24 h after transient middle cerebral artery occlusion (tMCAO), one of the standard models of focal ischemic stroke, Aβ peptide accumulates in the brain, concentrating on the blood vessel walls. Because Aβ oligomers are known to induce significant damage to brain cells, they act as an additional damaging factor during ischemic stroke. Considering that they have been shown to form ion channels in cells, affecting osmotic balance, we used an Aβ peptide channel blocker, tromethamine (2-amino-2-(hydroxymethyl) propane-1,3-diol), to prevent this additional injury. Tromethamine injected 0.1 g/100 g body weight intraperitoneally at 5 min before tMCAO decreased water content in the damaged hemisphere, as measured by dry brain weight. Congo red staining, which binds only to Aβ oligomer plaques (amyloid), showed that there was no significant presence of plaques. Therefore, we suggest that Aβ peptide oligomers are responsible for some of the brain damage during stroke and that blockage of the ion channels that they form could be beneficial in treating this complex neurological syndrome.
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Affiliation(s)
- Antonio Henrique Martins
- Pharmacology and Toxicology Department, University of Puerto Rico, Medical Sciences Campus, Guillermo Arbona, Área de Centro Médico Río Piedras, PR 00935, USA
| | - Astrid Zayas-Santiago
- Department of Physiology, Universidad Central del Caribe Ave. Laurel #100, Santa Juanita, Bayamón, PR 00956, USA
| | - Yancy Ferrer-Acosta
- Department of Neuroscience, Universidad Central del Caribe Ave. Laurel #U26, Santa Juanita, Bayamón, PR 00956, USA
| | - Solianne M Martinez-Jimenez
- Department of Neuroscience, Universidad Central del Caribe Ave. Laurel #U26, Santa Juanita, Bayamón, PR 00956, USA
| | - Lidia Zueva
- Department of Physiology, Universidad Central del Caribe Ave. Laurel #100, Santa Juanita, Bayamón, PR 00956, USA
| | - Amanda Diaz-Garcia
- Department of Physiology, Universidad Central del Caribe Ave. Laurel #100, Santa Juanita, Bayamón, PR 00956, USA
| | - Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe Ave. Laurel #100, Santa Juanita, Bayamón, PR 00956, USA.
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16
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Zueva L, Golubeva T, Korneeva E, Resto O, Inyushin M, Khmelinskii I, Makarov V. Quantum mechanism of light energy propagation through an avian retina. J Photochem Photobiol B 2019; 197:111543. [PMID: 31279896 PMCID: PMC6711473 DOI: 10.1016/j.jphotobiol.2019.111543] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/16/2022]
Abstract
Taking into account the ultrastructure of the Pied Flycatcher foveal retina reported earlier and the earlier reported properties of Müller cell (MC) intermediate filaments (IFs) isolated from vertebrate retina, we proposed a quantum mechanism (QM) of light energy transfer from the inner limiting membrane level to visual pigments in the photoreceptor cells. This mechanism involves electronic excitation energy transfer in a donor-acceptor system, with the IFs excited by photons acting as energy donors, and visual pigments in the photoreceptor cells acting as energy acceptors. It was shown earlier that IFs with diameter 10 nm and length 117 μm isolated from vertebrate eye retina demonstrate properties of light energy guide, where exciton propagates along such IFs from MC endfeet area to photoreceptor cell area. The energy is mostly transferred via the contact exchange quantum mechanism. Our estimates demonstrate that energy transfer efficiencies in such systems may exceed 80-90%. Thus, the presently developed quantum mechanism of light energy transfer in the inverted retina complements the generally accepted classic optical mechanism and the mechanism whereby Müller cells transmit light like optical fibers. The proposed QM of light energy transfer in the inverted retina explains the high image contrast achieved in photopic conditions by an avian eye, being probably also active in other vertebrates.
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Affiliation(s)
- Lidia Zueva
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA; Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez pr. 44, 194223 St-Petersburg, Russia; Universidad Central del Caribe, Bayamón, PR 00960-6032, USA
| | - Tatiana Golubeva
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Elena Korneeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova st., 5a, 117485 Moscow, Russia
| | - Oscar Resto
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
| | | | - Igor Khmelinskii
- Universidade do Algarve, FCT, DQB and CEOT, 8005-139 Faro, Portugal
| | - Vladimir Makarov
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA.
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17
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Inyushin M, Zayas-Santiago A, Rojas L, Kucheryavykh Y, Kucheryavykh L. Platelet-generated amyloid beta peptides in Alzheimer's disease and glaucoma. Histol Histopathol 2019; 34:843-856. [PMID: 30945258 PMCID: PMC6667289 DOI: 10.14670/hh-18-111] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyloid beta (Aβ) peptides have been implicated in both Alzheimer's disease (AD) and glaucoma and have been shown to be the key etiological factor in these dangerous health complications. On the other hand, it is well known that Aβ peptide can be generated from its precursor protein and massively released from the blood to nearby tissue upon the activation of platelets due to their involvement in innate immunity and inflammation processes. Here we review evidence about the development of AD and glaucoma neuronal damage showing their dependence on platelet count and activation. The correlation between the effect on platelet count and the effectiveness of anti-AD and anti-glaucoma therapies suggest that platelets may be an important player in these diseases.
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Affiliation(s)
- Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe (UCC), PR, USA.
| | | | - Legier Rojas
- School of Medicine, Universidad Central del Caribe (UCC), PR, USA
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18
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Khmelinskii I, Golubeva T, Korneeva E, Inyushin M, Zueva L, Makarov V. Spectral selectivity model for light transmission by the intermediate filaments in Müller cells. J Photochem Photobiol B 2017; 173:282-290. [PMID: 28623820 PMCID: PMC5642305 DOI: 10.1016/j.jphotobiol.2017.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 06/01/2017] [Accepted: 06/02/2017] [Indexed: 11/16/2022]
Abstract
Presently we continue our studies of the quantum mechanism of light energy transmission in the form of excitons by axisymmetric nanostructures with electrically conductive walls. Using our theoretical model, we analyzed the light energy transmission by biopolymers forming optical channels within retinal Müller cells. There are specialized intermediate filaments (IF) 10-18nm in diameter, built of electrically conductive polypeptides. Presently, we analyzed the spectral selectivity of these nanostructures. We found that their transmission spectrum depends on their diameter and wall thickness. We also considered the classical approach, comparing the results with those predicted by the quantum mechanism. We performed experimental measurements on model quantum waveguides, made of rectangular nanometer-thick chromium (Cr) tracks. The optical spectrum of such waveguides varied with their thickness. We compared the experimental absorption/transmission spectra with those predicted by our model, with good agreement between the two. We report that the observed spectra may be explained by the same mechanisms as operating in metal nanolayers. Both the models and the experiment show that Cr nanotracks have high light transmission efficiency in a narrow spectral range, with the spectral maximum dependent on the layer thickness. Therefore, a set of intermediate filaments with different geometries may provide light transmission over the entire visible spectrum with a very high (~90%) efficiency. Thus, we believe that high contrast and visual resolution in daylight are provided by the quantum mechanism of energy transfer in the form of excitons, whereas the ultimate retinal sensitivity of the night vision is provided by the classical mechanism of photons transmitted by the Müller cell light-guides.
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Affiliation(s)
- Igor Khmelinskii
- Universidade do Algarve, FCT, DQF and CIQA, 8005-139 Faro, Portugal
| | - Tatiana Golubeva
- Lomonosov Moscow State University, Department of Vertebrate Zoology, Moscow 119992, Russia
| | - Elena Korneeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova st., 5a, 117485 Moscow, Russia
| | | | - Lidia Zueva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia; University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
| | - Vladimir Makarov
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA.
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19
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Makarov V, Zueva L, Golubeva T, Korneeva E, Khmelinskii I, Inyushin M. Quantum mechanism of light transmission by the intermediate filaments in some specialized optically transparent cells. Neurophotonics 2017; 4:011005. [PMID: 27570792 PMCID: PMC4985621 DOI: 10.1117/1.nph.4.1.011005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/20/2016] [Indexed: 06/02/2023]
Abstract
Some very transparent cells in the optical tract of vertebrates, such as the lens fiber cells, possess certain types of specialized intermediate filaments (IFs) that have essential significance for their transparency. The exact mechanism describing why the IFs are so important for transparency is unknown. Recently, transparency was described also in the retinal Müller cells (MCs). We report that the main processes of the MCs contain bundles of long specialized IFs, each about 10 nm in diameter; most likely, these filaments are the channels providing light transmission to the photoreceptor cells in mammalian and avian retinas. We interpret the transmission of light in such channels using the notions of quantum confinement, describing energy transport in structures with electroconductive walls and diameter much smaller than the wavelength of the respective photons. Model calculations produce photon transmission efficiency in such channels exceeding 0.8, in optimized geometry. We infer that protein molecules make up the channels, proposing a qualitative mechanism of light transmission by such structures. The developed model may be used to describe light transmission by the IFs in any transparent cells.
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Affiliation(s)
- Vladimir Makarov
- University of Puerto Rico, Department of Physics, Rio Piedras Campus, P.O. Box 23343, San Juan 00931-3343, Puerto Rico
| | - Lidia Zueva
- Russian Academy of Sciences, Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia
| | - Tatiana Golubeva
- Lomonosov State University, Department of Vertebrate Zoology, Moscow 119992, Russia
| | - Elena Korneeva
- Russian Academy of Sciences, Institute of Higher Nervous Activity and Neurophysiology, Butlerova Street 5a, Moscow 117485, Russia
| | - Igor Khmelinskii
- Universidade do Algarve, Centro de Investigação em Química do Algarve (CIQA), Faro 8005-139, Portugal
| | - Mikhail Inyushin
- Universidad Central del Caribe, School of Medicine, Department of Physiology, Bayamón 00960-6032, Puerto Rico
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20
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Makarov V, Zueva L, Golubeva T, Korneeva E, Khmelinskii I, Inyushin M. Errata: Quantum mechanism of light transmission by the intermediate filaments in some specialized optically transparent cells. Neurophotonics 2017; 4:019801. [PMID: 27660802 PMCID: PMC5020596 DOI: 10.1117/1.nph.4.1.019801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
[This corrects the article DOI: 10.1117/1.NPh.4.1.011005.].
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Affiliation(s)
- Vladimir Makarov
- University of Puerto Rico , Department of Physics, Rio Piedras Campus, P.O. Box 23343, San Juan 00931-3343, Puerto Rico
| | - Lidia Zueva
- Russian Academy of Sciences , Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia
| | - Tatiana Golubeva
- Lomonosov State University , Department of Vertebrate Zoology, Moscow 119992, Russia
| | - Elena Korneeva
- Russian Academy of Sciences , Institute of Higher Nervous Activity and Neurophysiology, Butlerova Street 5a, Moscow 117485, Russia
| | - Igor Khmelinskii
- Universidade do Algarve , Centro de Investigação em Química do Algarve (CIQA), Faro 8005-139, Portugal
| | - Mikhail Inyushin
- Universidad Central del Caribe, School of Medicine, Department of Physiology, Bayamón 00960-6032, Puerto Rico
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Morales-Cruz M, Cruz-Montañez A, Figueroa CM, González-Robles T, Davila J, Inyushin M, Loza-Rosas SA, Molina AM, Muñoz-Perez L, Kucheryavykh LY, Tinoco AD, Griebenow K. Combining Stimulus-Triggered Release and Active Targeting Strategies Improves Cytotoxicity of Cytochrome c Nanoparticles in Tumor Cells. Mol Pharm 2016; 13:2844-54. [PMID: 27283751 DOI: 10.1021/acs.molpharmaceut.6b00461] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Proteins often possess highly specific biological activities that make them potential therapeutics, but their physical and chemical instabilities during formulation, storage, and delivery have limited their medical use. Therefore, engineering of nanosized vehicles to stabilize protein therapeutics and to allow for targeted treatment of complex diseases, such as cancer, is of considerable interest. A micelle-like nanoparticle (NP) was designed for both, tumor targeting and stimulus-triggered release of the apoptotic protein cytochrome c (Cyt c). This system is composed of a Cyt c NP stabilized by a folate-receptor targeting amphiphilic copolymer (FA-PEG-PLGA) attached to Cyt c through a redox-sensitive bond. FA-PEG-PLGA-S-S-Cyt c NPs exhibited excellent stability under extracellular physiological conditions, whereas once in the intracellular reducing environment, Cyt c was released from the conjugate. Under the same conditions, the folate-decorated NP reduced folate receptor positive HeLa cell viability to 20%, while the same complex without FA only reduced it to 80%. Confocal microscopy showed that the FA-PEG-PLGA-S-S-Cyt c NPs were internalized by HeLa cells and were capable of endosomal escape. The specificity of the folate receptor-mediated internalization was confirmed by the lack of uptake by two folate receptor deficient cell lines: A549 and NIH-3T3. Finally, the potential as antitumor therapy of our folate-decorated Cyt c-based NPs was confirmed with an in vivo brain tumor model. In conclusion, we were able to create a stable, selective, and smart nanosized Cyt c delivery system.
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Affiliation(s)
- Moraima Morales-Cruz
- Department of Biology, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Alejandra Cruz-Montañez
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Cindy M Figueroa
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Tania González-Robles
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Josue Davila
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine , Bayamón 00560, Puerto Rico
| | - Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, School of Medicine , Bayamón 00560, Puerto Rico
| | - Sergio A Loza-Rosas
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Anna M Molina
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Laura Muñoz-Perez
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Lilia Y Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine , Bayamón 00560, Puerto Rico
| | - Arthur D Tinoco
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
| | - Kai Griebenow
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan 00931, Puerto Rico
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22
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Zueva L, Golubeva T, Korneeva E, Makarov V, Khmelinskii I, Inyushin M. Foveolar Müller Cells of the Pied Flycatcher: Morphology and Distribution of Intermediate Filaments Regarding Cell Transparency. Microsc Microanal 2016; 22:379-386. [PMID: 26926795 PMCID: PMC4940978 DOI: 10.1017/s1431927616000507] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Specialized intermediate filaments (IFs) have critical importance for the clearness and uncommon transparency of vertebrate lens fiber cells, although the physical mechanisms involved are poorly understood. Recently, an unusual low-scattering light transport was also described in retinal Müller cells. Exploring the function of IFs in Müller cells, we have studied the morphology and distribution pattern of IFs and other cytoskeletal filaments inside the Müller cell main processes in the foveolar part of the avian (pied flycatcher) retina. We found that some IFs surrounded by globular nanoparticles (that we suggest are crystallines) are present in almost every part of the Müller cells that span the retina, including the microvilli. Unlike IFs implicated in the mechanical architecture of the cell, these IFs are not connected to any specific cellular membranes. Instead, they are organized into bundles, passing inside the cell from the endfeet to the photoreceptor, following the geometry of the processes, and repeatedly circumventing numerous obstacles. We believe that the presently reported data effectively confirm that the model of nanooptical channels built of the IFs may provide a viable explanation of Müller cell transparency.
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Affiliation(s)
- Lidia Zueva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St-Petersburg, Russia,
| | - Tatiana Golubeva
- Lomonosov Moscow State University, Department of Vertebrate Zoology, 119992, Moscow, Russia,
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485, Moscow, Russia,
| | - Elena Korneeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485, Moscow, Russia,
| | - Vladimir Makarov
- University of Puerto Rico, Department of Physics, San Juan, PR 00931, USA,
| | - Igor Khmelinskii
- University of the Algarve, Faculty of Sciences and Technology, Faro 8005-139, Algarve, Portugal,
| | - Mikhail Inyushin
- Central University of the Caribbean, Department of Physiology, Bayamon, PR 00956, USA,
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Rolón-Reyes K, Kucheryavykh YV, Cubano LA, Inyushin M, Skatchkov SN, Eaton MJ, Harrison JK, Kucheryavykh LY. Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway. PLoS One 2015; 10:e0131059. [PMID: 26098895 PMCID: PMC4476590 DOI: 10.1371/journal.pone.0131059] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/27/2015] [Indexed: 01/03/2023] Open
Abstract
Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration through a mechanism independent of extracellular matrix degradation. Using western blot analysis, we found upregulation of proline rich tyrosine kinase 2 (Pyk2) protein phosphorylated at Tyr579/580 in glioma cells treated with microglia conditioned medium. This upregulation occurred in rodent C6 and GL261 as well as in human glioma cell lines with varying levels of invasiveness (U-87MG, A172, and HS683). siRNA knock-down of Pyk2 protein and pharmacological blockade by the Pyk2/focal-adhesion kinase (FAK) inhibitor PF-562,271 reversed the stimulatory effect of microglia on glioma migration in all cell lines. A lower concentration of PF-562,271 that selectively inhibits FAK, but not Pyk2, did not have any effect on glioma cell migration. Moreover, with the use of the CD11b-HSVTK microglia ablation mouse model we demonstrated that elimination of microglia in the implanted tumors (GL261 glioma cells were used for brain implantation) by the local in-tumor administration of Ganciclovir, significantly reduced the phosphorylation of Pyk2 at Tyr579/580 in implanted tumor cells. Taken together, these data indicate that microglial cells activate glioma cell migration/dispersal through the pro-migratory Pyk2 signaling pathway in glioma cells.
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Affiliation(s)
- Kimberleve Rolón-Reyes
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Yuriy V. Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Luis A. Cubano
- Department of Anatomy and Cell Biology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Serguei N. Skatchkov
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Misty J. Eaton
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
| | - Jeffrey K. Harrison
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida
| | - Lilia Y. Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico, United States of America
- * E-mail:
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Zueva L, Makarov V, Zayas-Santiago A, Golubeva T, Korneeva E, Savvinov A, Eaton M, Skatchkov S, Inyushin M. Müller Cell Alignment in Bird Fovea: Possible Role in Vision. ACTA ACUST UNITED AC 2014; 3:85-91. [DOI: 10.1166/jnsne.2014.1104] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zayas-Santiago A, Agte S, Rivera Y, Benedikt J, Ulbricht E, Karl A, Dávila J, Savvinov A, Kucheryavykh Y, Inyushin M, Cubano LA, Pannicke T, Veh RW, Francke M, Verkhratsky A, Eaton MJ, Reichenbach A, Skatchkov SN. Unidirectional photoreceptor-to-Müller glia coupling and unique K+ channel expression in Caiman retina. PLoS One 2014; 9:e97155. [PMID: 24831221 PMCID: PMC4022631 DOI: 10.1371/journal.pone.0097155] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/15/2014] [Indexed: 02/07/2023] Open
Abstract
Background Müller cells, the principal glial cells of the vertebrate retina, are fundamental for the maintenance and function of neuronal cells. In most vertebrates, including humans, Müller cells abundantly express Kir4.1 inwardly rectifying potassium channels responsible for hyperpolarized membrane potential and for various vital functions such as potassium buffering and glutamate clearance; inter-species differences in Kir4.1 expression were, however, observed. Localization and function of potassium channels in Müller cells from the retina of crocodiles remain, hitherto, unknown. Methods We studied retinae of the Spectacled caiman (Caiman crocodilus fuscus), endowed with both diurnal and nocturnal vision, by (i) immunohistochemistry, (ii) whole-cell voltage-clamp, and (iii) fluorescent dye tracing to investigate K+ channel distribution and glia-to-neuron communications. Results Immunohistochemistry revealed that caiman Müller cells, similarly to other vertebrates, express vimentin, GFAP, S100β, and glutamine synthetase. In contrast, Kir4.1 channel protein was not found in Müller cells but was localized in photoreceptor cells. Instead, 2P-domain TASK-1 channels were expressed in Müller cells. Electrophysiological properties of enzymatically dissociated Müller cells without photoreceptors and isolated Müller cells with adhering photoreceptors were significantly different. This suggests ion coupling between Müller cells and photoreceptors in the caiman retina. Sulforhodamine-B injected into cones permeated to adhering Müller cells thus revealing a uni-directional dye coupling. Conclusion Our data indicate that caiman Müller glial cells are unique among vertebrates studied so far by predominantly expressing TASK-1 rather than Kir4.1 K+ channels and by bi-directional ion and uni-directional dye coupling to photoreceptor cells. This coupling may play an important role in specific glia-neuron signaling pathways and in a new type of K+ buffering.
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Affiliation(s)
- Astrid Zayas-Santiago
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Silke Agte
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Division of Soft Matter Physics, Department of Physics, University of Leipzig, Leipzig, Germany
| | - Yomarie Rivera
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Jan Benedikt
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Elke Ulbricht
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Anett Karl
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - José Dávila
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Alexey Savvinov
- Department of Physical Sciences, Universidad de Puerto Rico, Recinto de Río Piedras, Río Piedras, Puerto Rico, United States of America
| | - Yuriy Kucheryavykh
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Mikhail Inyushin
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Luis A. Cubano
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Thomas Pannicke
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | | | - Mike Francke
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Translational Centre for Regenerative Medicine (TRM) University of Leipzig, Leipzig, Germany
| | - Alexei Verkhratsky
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Misty J. Eaton
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Andreas Reichenbach
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Serguei N. Skatchkov
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
- * E-mail:
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Kucheryavykh LY, Rolón-Reyes K, Kucheryavykh YV, Skatchkov S, Eaton MJ, Sanabria P, Wessinger WD, Inyushin M. Glioblastoma development in mouse brain: general reduction of OCTs and mislocalization of OCT3 transporter and subsequent uptake of ASP + substrate to the nuclei. ACTA ACUST UNITED AC 2014; 3:3-9. [PMID: 25165637 DOI: 10.1166/jnsne.2014.1091] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Organic cation transporters (OCTs) were first found and then isolated from cultured glioma cells. When glioma cells are implanted into brain the fate of OCTs varies with time after implantation and transporter type. Here we report that OCT1, OCT2 and OCT3 immunofluorescence is significantly reduced over time in implanted GL261 glioma cells, during tumor development in the brain. By day 21 after glioma implantation, OCT1, OCT2 and OCT3 immunofluorescence was reduced more than 10-fold in the cytoplasm of glioma cells, while OCT3 immunofluorescence became concentrated in the nucleus. The well-known fluorescent substrate for OCT transporters, 4-(4-(dimethylamino)-styryl)-N-methylpyridinium iodide (ASP+), previously shown to accumulate in glioma-cell cytoplasm in in vivo slices, began to accumulate in the nucleus of these cells, but not in cytoplasm, after 21 days post-implantation. Considering this mislocalization phenomenon, and other literature on similar nuclear mislocalization of different transporters, receptors and channels in glioma cells, we suggest that it is one of the "omens" preceding the motility and aggressivity changes in glioma behavior.
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Affiliation(s)
| | | | | | - Serguei Skatchkov
- Dept. of Biochemistry and Physiology, Universidad Central del Caribe, Bayamon, PR 00960, USA
| | - Misty J Eaton
- Dept. of Biochemistry, Universidad Central del Caribe, Bayamon, PR 00960, USA
| | - Priscila Sanabria
- Dept. of Physiology, Universidad Central del Caribe, Bayamon, PR 00960, USA
| | - William D Wessinger
- Dept. of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Mikhail Inyushin
- Dept. of Physiology, Universidad Central del Caribe, Bayamon, PR 00960, USA
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Sala-Rabanal M, Li DC, Dake GR, Kurata HT, Inyushin M, Skatchkov SN, Nichols CG. Polyamine transport by the polyspecific organic cation transporters OCT1, OCT2, and OCT3. Mol Pharm 2013; 10:1450-8. [PMID: 23458604 DOI: 10.1021/mp400024d] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Polyamines are ubiquitous organic cations implicated in many physiological processes. Because they are positively charged at physiological pH, carrier-mediated systems are necessary for effective membrane permeation, but the identity of specific polyamine transporter proteins in eukaryotic cells remains unclear. Polyspecific organic cation transporters (OCTs) interact with many natural and xenobiotic monovalent cations and have been reported to transport dicationic compounds, including the short polyamine putrescine. In this study, we used Xenopus oocytes expressing mammalian OCT1 (SLC22A1), OCT2 (SLC22A2), or OCT3 (SLC22A3) to assess binding and transport of longer-chain polyvalent polyamines. In OCT-expressing oocytes, [(3)H]MPP(+) uptake rates were 15- to 35-fold higher than in noninjected oocytes, whereas those for [(3)H]spermidine increased more modestly above the background, up to 3-fold. This reflected up to 20-fold lower affinity for spermidine than for MPP(+); thus, K(0.5) for MPP(+) was ~50 μM in OCT1, ~170 μM in OCT2, and ~60 μM in OCT3, whereas for spermidine, K(0.5) was ~1 mM in OCT1, OCT2, and OCT3. J(max) values for MPP(+) and spermidine were within the same range, suggesting that both compounds are transported at a similar turnover rate. To gain further insight into OCT substrate specificity, we screened a selection of structural polyamine analogues for effect on [(3)H]MPP(+) uptake. In general, blocking potency increased with overall hydrophobic character, which indicates that, as for monovalent cations, hydrophobicity is a major requirement for recognition in polyvalent OCT substrates and inhibitors. Our results demonstrate that the natural polyamines are low affinity, but relatively high turnover, substrates for OCTs. The identification of OCTs as polyamine transport systems may contribute to further understanding of the mechanisms involved in polyamine homeostasis and aid in the design of polyamine-like OCT-targeted drugs.
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Affiliation(s)
- Monica Sala-Rabanal
- Department of Cell Biology and Physiology, and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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Inyushin M, Kucheryavykh LY, Kucheryavykh YV, Nichols CG, Buono RJ, Ferraro TN, Skatchkov SN, Eaton MJ. Potassium channel activity and glutamate uptake are impaired in astrocytes of seizure-susceptible DBA/2 mice. Epilepsia 2010; 51:1707-13. [PMID: 20831751 DOI: 10.1111/j.1528-1167.2010.02592.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE KCNJ10 encodes subunits of inward rectifying potassium (Kir) channel Kir4.1 found predominantly in glial cells within the brain. Genetic inactivation of these channels in glia impairs extracellular K(+) and glutamate clearance and produces a seizure phenotype. In both mice and humans, polymorphisms and mutations in the KCNJ10 gene have been associated with seizure susceptibility. The purpose of the present study was to determine whether there are differences in Kir channel activity and potassium- and glutamate-buffering capabilities between astrocytes from seizure resistant C57BL/6 (B6) and seizure susceptible DBA/2 (D2) mice that are consistent with an altered K(+) channel activity as a result of genetic polymorphism of KCNJ10. METHODS Using cultured astrocytes and hippocampal brain slices together with whole-cell patch-clamp, we determined the electrophysiologic properties, particularly K(+) conductances, of B6 and D2 mouse astrocytes. Using a colorimetric assay, we determined glutamate clearance capacity by B6 and D2 astrocytes. RESULTS Barium-sensitive Kir currents elicited from B6 astrocytes are substantially larger than those elicited from D2 astrocytes. In addition, potassium and glutamate buffering by D2 cortical astrocytes is impaired, relative to buffering by B6 astrocytes. DISCUSSION In summary, the activity of Kir4.1 channels differs between seizure-susceptible D2 and seizure-resistant B6 mice. Reduced activity of Kir4.1 channels in astrocytes of D2 mice is associated with deficits in potassium and glutamate buffering. These deficits may, in part, explain the relatively low seizure threshold of D2 mice.
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Affiliation(s)
- Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico 00960-6032, USA
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Inyushin M, Kucheryavykh Y, Kucheryavykh L, Sanabria P, Jiménez-Rivera C, Struganova I, Eaton M, Skatchkov S. Membrane potential and pH-dependent accumulation of decynium-22 (1,1'-diethyl-2,2'-cyanine iodide) flourencence through OCT transporters in astrocytes. Bol Asoc Med P R 2010; 102:5-12. [PMID: 23875515 PMCID: PMC3721433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
1,1 '-Diethyl-2,2'-cyanine iodide (decynium22; D22) is a potent blocker of the organic cation family of transporters (EMT/OCT) known to move endogenous monoamines like dopamine and norepinephrine across cell membranes. Decynium22 is a cation with a relatively high affinity for all members of the OCT family in both human and rat cells. The mechanism through which decynium22 blocks OCT transporters are poorly understood. We tested the hypothesis that denynium22 may compete with monoamines utilizing OCT to permeate the cells. Using the ability of D22 to aggregate and produce fluorescence at 570 nm, we measured D22 uptake in cultured astrocytes. The rate of D22 uptake was strongly depressed by acid pH and by elevated external K+. The rate of uptake was similar to that displayed by 4-(4-(dimethylamino)-styryl)-N-methylpyridinium (ASP+), a well established substrate for OCT and high-affinity Na+-dependent monoamine transporters. These data were supported by measurement of electrogenic uptake using whole cell voltage clamp recording. Decynium22 depressed norepinephrine, but not glutamate uptake. These data are also consistent with the described OCT transporter characteristics. Taken together, our results suggest that decynium22 accumulation might be a useful instrument to study monoamine transport in the brain, and particularly in astrocytes, where they may play a prominent role in monoamine uptake during brain dysfunction related to monoamines (like Parkinson disease) and drug addiction.
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Affiliation(s)
- Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, PR
| | - Yuri Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, PR
| | - Lilia Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, PR
| | - Priscilla Sanabria
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, PR
| | - Carlos Jiménez-Rivera
- Department of Physiology, University of Puerto Rico, Medical Sciences Campus, San Juan, PR
| | | | - Misty Eaton
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, PR
| | - Serguei Skatchkov
- Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, PR
- Department of Biochemistry, Universidad Central del Caribe, School of Medicine, Bayamón, PR
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Kucheryavykh LY, Kucheryavykh YV, Inyushin M, Shuba YM, Sanabria P, Cubano LA, Skatchkov SN, Eaton MJ. Ischemia Increases TREK-2 Channel Expression in Astrocytes: Relevance to Glutamate Clearance. ACTA ACUST UNITED AC 2009; 3:40-47. [PMID: 19890471 DOI: 10.2174/1874082000903010040] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The extent of an ischemic insult is less in brain regions enriched in astrocytes suggesting that astrocytes maintain function and buffer glutamate during ischemia. Astrocytes express a wide variety of potassium channels to support their functions including TREK-2 channels which are regulated by polyunsaturated fatty acids, intracellular acidosis and swelling; conditions that pertain to ischemia. The present study investigated the possible involvement of TREK-2 channels in cultured cortical astrocytes during experimental ischemia (anoxia/hypoglycemia) by examining TREK-2 protein levels, channel activity and ability to clear glutamate. We found that TREK-2 protein levels were increased rapidly within 2 hrs of the onset of simulated ischemia. This increase corresponded to an increase in temperature-sensitive TREK-2-like channel conductance and the ability of astrocytes to buffer extracellular glutamate even during ischemia. Together, these data suggest that up-regulation of TREK-2 channels may help rescue astrocyte function and lower extracellular glutamate during ischemia.
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Affiliation(s)
- Lilia Y Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico
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