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(1 - 7 of 7)
- Title
- Reciprocal regulation between taurine and glutamate response via Ca2+ - dependent pathways in retinal third-order neurons.
- Creator
- Bulley, Simon, Shen, Wen
- Date Issued
- 2010-08-24
- PURL
- http://purl.flvc.org/fcla/dt/3327274
- Subject Headings
- Amacrine Cells*/cytology, Amacrine Cells*/drug effects, Amacrine Cells*/metabolism, Ambystoma, Calcium/metabolism, Calcium Channels/metabolism, Cells, Cultured, Enzyme Inhibitors/metabolism, Excitatory Amino Acid Agonists/pharmacology, GABA Antagonists/pharmacology, Glutamic Acid/metabolism, Glycine Agents/pharmacology, Kainic Acid/pharmacology, Membrane Glycoproteins, Membrane Potentials, Neurotransmitter Agents, Retinal Ganglion Cells, Signal Transduction, Synaptic Transmission
- Format
- Document (PDF)
- Title
- Angiographic Changes of Blood Vessels in the Photoreceptor Degenerative Mouse Retina.
- Creator
- Nguyen, Matthew, Shen, Wen, Office of Undergraduate Research and Inquiry
- Abstract/Description
-
Tortuous, or twisted, arteries and veins are commonly observed in humans and animals diagnosed with diseases caused by the degeneration of photoreceptor cells. However, the mechanisms of their formation and development are poorly understood. We used immunocytochemical, confocal imaging and computer remodeling techniques to map the angiographic changes in the photoreceptor degenerative mouse model, pde6d (rd1) mice. We found that mechanical instability and rewiring in the distal retina of rd1...
Show moreTortuous, or twisted, arteries and veins are commonly observed in humans and animals diagnosed with diseases caused by the degeneration of photoreceptor cells. However, the mechanisms of their formation and development are poorly understood. We used immunocytochemical, confocal imaging and computer remodeling techniques to map the angiographic changes in the photoreceptor degenerative mouse model, pde6d (rd1) mice. We found that mechanical instability and rewiring in the distal retina of rd1 mice could be mechanisms for the initiation and development of these tortuous vessels. We also found that in the late stages of retinal degeneration, severe tortuosity leads to ischemic attack in the distal retina. This study provides valuable insights into understanding the pathologic changes of retinal blood vessels in the development of diseases in humans and animals.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00005594
- Subject Headings
- College students --Research --United States.
- Format
- Document (PDF)
- Title
- Destructive Changes in the Neuronal Structure of the FVB/N Mouse Retina.
- Creator
- Yang, Jinnan, Nan, Changlong, Ripps, Harris, Shen, Wen, Barnes, Steven
- Date Issued
- 2015-06-19
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000114
- Format
- Citation
- Title
- Green tea extract catechin improves internal cardiac muscle relaxation in RCM mice.
- Creator
- Wang, Xiaoqin, Zhang, Zhengyu, Wu, Gang, Nan, Changlong, Shen, Wen, Hua, Yimin, Huang, Xupei
- Date Issued
- 2016-12-28
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000199
- Format
- Citation
- Title
- An investigation of membrane transporter proteins in the distal vertebrate retina: excitatory amino acid transporters and sodium potassium chloride cotransporters.
- Creator
- Purpura, Lauren Angeline, Shen, Wen, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Neurons are able to maintain membrane potential and synaptic integrity by an intricate equilibrium of membrane transporter proteins and ion channels. Two membrane proteins of particular importance in the vertebrate retina are the excitatory amino acid transporters (EAATs) which are responsible for the reuptake of glutamate into both glial and neuronal cells and the sodium potassium chloride cotransporters (NKCCs) that are responsible for the uptake of chloride ions into the cell. NKCCs are...
Show moreNeurons are able to maintain membrane potential and synaptic integrity by an intricate equilibrium of membrane transporter proteins and ion channels. Two membrane proteins of particular importance in the vertebrate retina are the excitatory amino acid transporters (EAATs) which are responsible for the reuptake of glutamate into both glial and neuronal cells and the sodium potassium chloride cotransporters (NKCCs) that are responsible for the uptake of chloride ions into the cell. NKCCs are electro-neutral with the uptake of 2 Cl- coupled to an exchange of a potassium and Na+ ion into the cells. Therefore, there is little change of cell membrane potential in the action of NKCCs. In this study the localization and function of EAATs in the distal retina is investigated. Whole cell patch clamp recordings in lower vertebrate retina have demonstrated that EAAT2 is the main synaptic EAATs in rod photoreceptors and it is localized to the axon terminals. Furthermore, the action of the transporter seems to be modified by intracellular calcium concentration. There is also evidence that EAAT2 might be regulated by feedback from the neuron network by glycinergic and GABAergic mechanisms. The second half of this study investigates expression of NKCCs in the retina by western blot analysis and quantitative polymerase chain reaction. There are two forms of NKCCs, NKCC1 and NKCC2. NKCC1 is mostly expressed in the central nervous system and NKCC2 was thought to only be expressed in the kidneys. NKCC1 is responsible for the majority of chloride uptake into neuronal and epithelial cells and NKCC1 is expressed in the distal retina where photoreceptors synapse on second order horizontal and bipolar cells. This study found the expression of NKCC1 in the distal retina to be regulated by temporal light and dark adaptation. Light adaptation increased phosphorylated NKCC1 expression (the active form of the cotransporter). The increase in NKCC1 expression during light adaptation was modulated by dopamine. Specifically, a D1 receptor agonist increased phosphorylated NKCC1 expression. Dopamine is an essential chemical and receptor known for initiating light adaptation in retina. Finally, an NKCC1 knockout mouse model was examined and it revealed that both forms of NKCC are expressed in the vertebrate retina.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004224, http://purl.flvc.org/fau/fd/FA00004224
- Subject Headings
- Biological transport, Carrier proteins, Cellular signal transduction, Neural receptors, Retina -- Cytology
- Format
- Document (PDF)
- Title
- PHOTORECEPTOR DEGENERATION AND ABNORMAL RETINAL VASCULOGENESIS.
- Creator
- Nguyen, Matthew, Shen, Wen, Florida Atlantic University, Department of Biomedical Science, Charles E. Schmidt College of Medicine
- Abstract/Description
-
Abnormal vasculature in the retina, specifically tortuous blood vessels, are common to many of the most prevalent retinal degenerative diseases currently affecting millions across the world. The mechanisms of their formation and development in the context of retinal degenerative disease, however, are still poorly understood. The rd1 and rd10 mice are relatively well-studied animal models of retinal degenerative disease, however, there lacks a systematic characterization of vascular changes co...
Show moreAbnormal vasculature in the retina, specifically tortuous blood vessels, are common to many of the most prevalent retinal degenerative diseases currently affecting millions across the world. The mechanisms of their formation and development in the context of retinal degenerative disease, however, are still poorly understood. The rd1 and rd10 mice are relatively well-studied animal models of retinal degenerative disease, however, there lacks a systematic characterization of vascular changes co-related to photoreceptor degeneration in the rd1 and rd10 retina. Here, we utilize advancements in confocal microscopy, immunohistochemistry, and image analysis software in order to systematically characterize vascular changes before and after retinal development in the rd1 and rd10 mice. We show that there are plexus specific changes in the retinal vasculature that parallel photoreceptor degeneration. Such information will be of particular use to future studies investigating the role of vascular changes in retinal degenerative disease therapies.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013818
- Subject Headings
- Retinal Degeneration, Retinal Vessels--pathology, Retina—Diseases, Photoreceptors
- Format
- Document (PDF)
- Title
- A CELL BIOLOGICAL AND ELECTROPHYSIOLOGICAL STUDY OF MOUSE RETINA.
- Creator
- Sullivan, James P., Shen, Wen, Prentice, Howard, Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Both proliferative diabetic retinopathy and exudative age-related macular degeneration are major causes of blindness which are caused by growth of defective, leaky and tortuous blood vessels in the retina. Hypoxia is implicated in triggering both of these diseases and results in induction of HIF-1alpha transcription factor in addition to the angiogenic factor VEGF. Müller cells are the major glial cell in the retina and they contribute to neovascularization in hypoxic regions of the retina...
Show moreBoth proliferative diabetic retinopathy and exudative age-related macular degeneration are major causes of blindness which are caused by growth of defective, leaky and tortuous blood vessels in the retina. Hypoxia is implicated in triggering both of these diseases and results in induction of HIF-1alpha transcription factor in addition to the angiogenic factor VEGF. Müller cells are the major glial cell in the retina and they contribute to neovascularization in hypoxic regions of the retina through eliciting secretion of growth factors, cytokines and angiogenic factors. As Müller cells span the breadth of the retina they can secrete angiostatic factors as well as neuroprotective trophic factors, the Müller cell is a valuable cell type for targeting by potential new gene therapies. The current investigation tests the hypoxia responsiveness of an AAV vector containing a hybrid hypoxia response element together with a GFAP promoter, and this vector encodes the angiostatic protein decorin, a well characterized multi-receptor tyrosine kinase inhibitor. Decorin may have advantages over other key angiostatic factors such as endostatin or angiostatin by virtue of its multiple anti-angiogenic signaling modalities. We employed Q-RT-PCR to evaluate the cell specificity and hypoxia responsiveness of an AAV-Vector termed AAV-REG-Decorin containing a hybrid HRE and GFAP promoter driving expression of the decorin transgene. The vector also contains a silencer element between the HRE and the GFAP domains to enable low basal expression in normoxia as well as high level inducibility in hypoxia. AAV-REGDecorin was found to elicit high level expression of decorin mRNA in hypoxia with greater than 9 – fold induction of the transgene in hypoxic conditions in astrocytes by comparison to normoxic astrocytes. AAV-REG-Decorin showed low levels of transgene expression by comparison to the positive control vector AAV-CMV -decorin containing the ubiquitously active CMV-promoter. The expression levels of decorin mRNA from AAV-REG-Decorin and from AAV-GFAP-Decorin were low in the PC12 neuronal cell model and in the ARPE19 line of retinal pigment epithelial cells with respect to those of AAV-CMV-decorin and no induction of Decorin mRNA was found with AAV-REGDecorin in these two control cell lines. Our novel gene therapy vector will serve as a platform for testing efficacy in rodent disease models (OIR and laser induced choroidal neovascularization) for assessment of the benefits of tightly regulated antiangiogenic gene therapy eliciting decorin transgene expression, both in terms of timing and the cellular source of production, during the progression of the retinal pathophysiology.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013725
- Subject Headings
- Macular Degeneration, Retina, Gene therapy, Decorin
- Format
- Document (PDF)
