Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
Biochem Biophys Rep ; 39: 101799, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39161576

RESUMO

Neurodegenerative diseases including glaucoma affect insulin signaling, and insulin treatment has been shown to reverse the neurodegenerative loss of dendritic complexity in retinal ganglion cells. Therefore, strategies for enhancing or maintaining insulin signaling are worth pursuing to establish new therapies for these diseases. In the present study, we generated constitutively active insulin receptor (F-iIR) and insulin-like growth factor-1 receptor (F-iIGF1R) using a system that forces membrane localization of the intracellular domains of these receptors by farnesylation. Immunohistochemistry and Western blot analysis revealed that F-iIR and F-iIGF1R caused the activation of ERK and AKT in the absence of ligands in vitro. Our results suggest that in vivo effects of F-iIR and F-iIGF1R on the progression of neurodegenerative diseases should be investigated in the future.

2.
Neuropathology ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775061

RESUMO

Multiple sclerosis (MS), the leading cause of disability in young adults, is an inflammatory disease of the central nervous system characterized by localized areas of demyelination. Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that has been shown to be implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Interestingly, ASK1 signaling regulates glial cell interactions and drives neuroinflammation in EAE mice. To further investigate its clinical significance, in the present study, we examined the activation of ASK1 in the post-mortem brain of MS patients. ASK1 activation was found in active lesions of the corpus callosum in both microglia/macrophages and astrocytes. Moreover, ASK1 activation in astrocytes was higher than that in microglia/macrophages, which was in line with our findings in EAE mice. Our results suggest an important role of ASK1 in glial cells, indicating that ASK1 might be a good therapeutic target for MS.

3.
J Pharmacol Sci ; 154(4): 326-333, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485351

RESUMO

PURPOSE: To determine whether combination of topical ripasudil and brimonidine has more effective neuroprotection on retinal ganglion cells (RGCs) following injury to axons composing the optic nerve. METHODS: Topical ripasudil, brimonidine, or mixture of both drugs were administered to adult mice after optic nerve injury (ONI). The influence of drug conditions on RGC health were evaluated by the quantifications of surviving RGCs, phosphorylated p38 mitogen-activated protein kinase (phospho-p38), and expressions of trophic factors and proinflammatory mediators in the retina. RESULTS: Topical ripasudil and brimonidine suppressed ONI-induced RGC death respectively, and mixture of both drugs further stimulated RGC survival. Topical ripasudil and brimonidine suppressed ONI-induced phospho-p38 in the whole retina. In addition, topical ripasudil suppressed expression levels of TNFα, IL-1ß and monocyte chemotactic protein-1 (MCP-1), whereas topical brimonidine increased the expression level of basic fibroblast growth factor (bFGF). CONCLUSIONS: Combination of topical ripasudil and brimonidine may enhance RGC protection by modulating multiple signaling pathways in the retina.


Assuntos
Isoquinolinas , Traumatismos do Nervo Óptico , Sulfonamidas , Camundongos , Animais , Tartarato de Brimonidina , Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/metabolismo , Neuroproteção , Combinação de Medicamentos
4.
Cell Death Discov ; 9(1): 166, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37188749

RESUMO

Dedicator of cytokinesis 3 (DOCK3) is an atypical member of the guanine nucleotide exchange factors (GEFs) and plays important roles in neurite outgrowth. DOCK3 forms a complex with Engulfment and cell motility protein 1 (Elmo1) and effectively activates Rac1 and actin dynamics. In this study, we screened 462,169 low-molecular-weight compounds and identified the hit compounds that stimulate the interaction between DOCK3 and Elmo1, and neurite outgrowth in vitro. Some of the derivatives from the hit compound stimulated neuroprotection and axon regeneration in a mouse model of optic nerve injury. Our findings suggest that the low-molecular-weight DOCK3 activators could be a potential therapeutic candidate for treating axonal injury and neurodegenerative diseases including glaucoma.

5.
Neurosci Lett ; 799: 137124, 2023 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-36780941

RESUMO

Visual disturbance after optic nerve injury is a serious problem. Attempts have been made to enhance the intrinsic ability of retinal ganglion cells (RGCs) to regenerate their axons, and the importance of PI3K/Akt and RAF/MEK/ERK signal activation has been suggested. Since these signals are shared with oncogenic signaling cascades, in this study, we focused on a constitutively active form of K-Ras, K-RasV12, to determine if overexpression of this molecule could stimulate axon regeneration. We confirmed that K-RasV12 phosphorylated Akt and ERK in vitro. Intravitreal delivery of AAV2-K-RasV12 increased the number of surviving RGCs and promoted 1.0 mm of axon regeneration one week after optic nerve injury without inducing abnormal proliferative effects in the RGCs. In addition, AAV2-K-RasV12 induced robust RGC axon regeneration, reaching as far as approximately 2.5 mm from the injury site, in eight weeks. Our findings suggest that AAV2-K-RasV12 could provide a good model for speedy and efficient analysis of the mechanism underlying axon regeneration in vivo.


Assuntos
Traumatismos do Nervo Óptico , Humanos , Axônios/fisiologia , Proteínas Proto-Oncogênicas c-akt , Fosfatidilinositol 3-Quinases , Regeneração Nervosa/fisiologia
6.
Mol Ther ; 31(3): 810-824, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36463402

RESUMO

Activation of neurotrophic factor signaling is a promising therapy for neurodegeneration. However, the transient nature of ligand-dependent activation limits its effectiveness. In this study, we solved this problem by inventing a system that forces membrane localization of the intracellular domain of tropomyosin receptor kinase B (iTrkB), which results in constitutive activation without ligands. Our system overcomes the small size limitation of the genome packaging in adeno-associated virus (AAV) and allows high expression of the transgene. Using AAV-mediated gene therapy in the eyes, we demonstrate that iTrkB expression enhances neuroprotection in mouse models of glaucoma and stimulates robust axon regeneration after optic nerve injury. In addition, iTrkB expression in the retina was also effective in an optic tract transection model, in which the injury site is near the superior colliculus. Regenerating axons successfully formed pathways to their brain targets, resulting in partial recovery of visual behavior. Our system may also be applicable to other trophic factor signaling pathways and lead to a significant advance in the field of gene therapy for neurotrauma and neurodegenerative disorders, including glaucoma.


Assuntos
Glaucoma , Células Ganglionares da Retina , Camundongos , Animais , Células Ganglionares da Retina/metabolismo , Axônios/fisiologia , Regeneração Nervosa/genética , Retina , Glaucoma/genética , Glaucoma/terapia , Glaucoma/metabolismo , Modelos Animais de Doenças
7.
Exp Eye Res ; 226: 109314, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36400285

RESUMO

Glaucoma is one of the most common causes of blindness worldwide. It is thought to be a multifactorial disease with underlying mechanisms that include mitochondrial dysfunction and oxidative stress. Here, we used NF-E2 related factor 2 (Nrf2) knockout (KO) mice, which are vulnerable to oxidative stress, to examine a neuroprotective effect against oxidative stress due to rotenone, a mitochondrial complex I inhibitor. Wild-type (WT) and Nrf2 KO mice received an oral solution of rotenone for 30 days. We then extracted the retinas and performed immunohistochemistry and quantitative RT-PCR. We also prepared a primary Müller cell culture of samples from each mouse, added 30 µM rotenone, and then measured cell viability, cytotoxicity and CellRox absorbance. We also examined gene expression. We found a significant increase in the number of 8-OHdG-positive retinal ganglion cells (RGCs) after rotenone administration in both the WT and Nrf2 KO mice. There was no difference in the number of RNA-binding protein with multiple splicing (RBPMS)-positive RGCs in the WT and Nrf2 KO mice, but Nrf2 KO mice that were given rotenone had significantly less retinal gene expression of RBPMS than Nrf2 KO mice given a control. Moreover, there was significantly higher mRNA gene expression of vimentin and glial fibrillary acidic protein (GFAP) in Nrf2 KO mice that received rotenone than WT mice that received rotenone. A statistical analysis of the in vitro experiment showed that cell viability was lower, cytotoxicity was higher, and oxidative stress was higher in the Müller cells of the Nrf2 KO mice than the WT mice. Finally, brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor (bFGF) were significantly higher in the Müller cells of the Nrf2 KO mice than the WT mice. These findings suggest that in Nrf2 KO mice under oxidative stress caused by rotenone, temporary neurotrophic factors are secreted from the Müller cells, conferring neuroprotection in these cells.


Assuntos
Fator 2 Relacionado a NF-E2 , Rotenona , Camundongos , Animais , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Rotenona/toxicidade , Rotenona/metabolismo , Fatores de Crescimento Neural/metabolismo , Estresse Oxidativo , Neuroglia/metabolismo , Camundongos Endogâmicos C57BL
8.
Front Ophthalmol (Lausanne) ; 3: 1310226, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38983026

RESUMO

Glial cells, a type of non-neuronal cell found in the central nervous system (CNS), play a critical role in maintaining homeostasis and regulating CNS functions. Recent advancements in technology have paved the way for new therapeutic strategies in the fight against glaucoma. While intraocular pressure (IOP) is the most well-known modifiable risk factor, a significant number of glaucoma patients have normal IOP levels. Because glaucoma is a complex, multifactorial disease influenced by various factors that contribute to its onset and progression, it is imperative that we consider factors beyond IOP to effectively prevent or slow down the disease's advancement. In the realm of CNS neurodegenerative diseases, glial cells have emerged as key players due to their pivotal roles in initiating and hastening disease progression. The inhibition of dysregulated glial function holds the potential to protect neurons and restore brain function. Consequently, glial cells represent an enticing therapeutic candidate for glaucoma, even though the majority of glaucoma research has historically concentrated solely on retinal ganglion cells (RGCs). In addition to the neuroprotection of RGCs, the proper regulation of glial cell function can also facilitate structural and functional recovery in the retina. In this review, we offer an overview of recent advancements in understanding the non-cell-autonomous mechanisms underlying the pathogenesis of glaucoma. Furthermore, state-of-the-art technologies have opened up possibilities for regenerating the optic nerve, which was previously believed to be incapable of regeneration. We will also delve into the potential roles of glial cells in the regeneration of the optic nerve and the restoration of visual function.

9.
Sci Adv ; 8(44): eabq1081, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36332025

RESUMO

Astrocyte abnormalities have received great attention for their association with various diseases in the brain but not so much in the eye. Recent independent genome-wide association studies of glaucoma, optic neuropathy characterized by retinal ganglion cell (RGC) degeneration, and vision loss found that single-nucleotide polymorphisms near the ABCA1 locus were common risk factors. Here, we show that Abca1 loss in retinal astrocytes causes glaucoma-like optic neuropathy in aged mice. ABCA1 was highly expressed in retinal astrocytes in mice. Thus, we generated macroglia-specific Abca1-deficient mice (Glia-KO) and found that aged Glia-KO mice had RGC degeneration and ocular dysfunction without affected intraocular pressure, a conventional risk factor for glaucoma. Single-cell RNA sequencing revealed that Abca1 deficiency in aged Glia-KO mice caused astrocyte-triggered inflammation and increased the susceptibility of certain RGC clusters to excitotoxicity. Together, astrocytes play a pivotal role in eye diseases, and loss of ABCA1 in astrocytes causes glaucoma-like neuropathy.

10.
Genes Cells ; 27(8): 526-536, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35703119

RESUMO

Glaucoma is a neurodegenerative disorder caused by the death of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) is a cause of glaucoma. However, glaucoma often develops with normal IOP and is known as normal-tension glaucoma (NTG). Glutamate neurotoxicity is considered as one of the significant causes of NTG, resulting in excessive stimulation of retinal neurons via the N-methyl-D-aspartate (NMDA) receptors. The present study examined the phosphorylation of collapsin response mediator protein-2 (CRMP2), a protein that is abundantly expressed in neurons and involved in their development. In two mouse models, NMDA-injection and glutamate/aspartate transporter (GLAST) mutant, CRMP2 phosphorylation at the cyclin-dependent kinase-5 (Cdk5) site was elevated in RGCs. We confirmed that the decrease in the number of RGCs and thickness of the inner retinal layer (IRL) could be suppressed after NMDA administration in CRMP2KI/KI mice with genetically inhibited CRMP2 phosphorylation. Next, we investigated GLAST heterozygotes (GLAST+/-) with CRMP2KI/KI (GLAST+/-;CRMP2KI/KI) and GLAST knockout (GLAST-/-) mice with CRMP2KI/KI (GLAST-/-;CRMP2KI/KI) mice and compared them with GLAST+/- and GLAST-/- mice. pCRMP2 (S522) inhibition significantly reduced RGC loss and IRL thinning. These results suggest that the inhibition of CRMP2 phosphorylation could be a novel strategy for treating NTG.


Assuntos
Glaucoma , Células Ganglionares da Retina , Animais , Modelos Animais de Doenças , Glaucoma/genética , Glaucoma/metabolismo , Ácido Glutâmico/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos , N-Metilaspartato , Proteínas do Tecido Nervoso , Fosforilação , Células Ganglionares da Retina/metabolismo
11.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35101972

RESUMO

Neuroinflammation is well known to be associated with neurodegenerative diseases. Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that has been implicated in neuroinflammation, but its precise cellular and molecular mechanisms remain unknown. In this study, we generated conditional knockout (CKO) mice that lack ASK1 in T cells, dendritic cells, microglia/macrophages, microglia, or astrocytes, to assess the roles of ASK1 during experimental autoimmune encephalomyelitis (EAE). We found that neuroinflammation was reduced in both the early and later stages of EAE in microglia/macrophage-specific ASK1 knockout mice, whereas only the later-stage neuroinflammation was ameliorated in astrocyte-specific ASK1 knockout mice. ASK1 deficiency in T cells and dendritic cells had no significant effects on EAE severity. Further, we found that ASK1 in microglia/macrophages induces a proinflammatory environment, which subsequently activates astrocytes to exacerbate neuroinflammation. Microglia-specific ASK1 deletion was achieved using a CX3CR1CreER system, and we found that ASK1 signaling in microglia played a major role in generating and maintaining disease. Activated astrocytes produce key inflammatory mediators, including CCL2, that further activated and recruited microglia/macrophages, in an astrocytic ASK1-dependent manner. Astrocyte-specific analysis revealed CCL2 expression was higher in the later stage compared with the early stage, suggesting a greater proinflammatory role of astrocytes in the later stage. Our findings demonstrate cell-type-specific roles of ASK1 and suggest phase-specific ASK1-dependent glial cell interactions in EAE pathophysiology. We propose glial ASK1 as a promising therapeutic target for reducing neuroinflammation.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , MAP Quinase Quinase Quinase 5/imunologia , Microglia/imunologia , Esclerose Múltipla/imunologia , Transdução de Sinais/imunologia , Animais , Células Dendríticas/imunologia , Encefalomielite Autoimune Experimental/genética , Inflamação/genética , Inflamação/imunologia , MAP Quinase Quinase Quinase 5/genética , Macrófagos/imunologia , Camundongos , Camundongos Knockout , Esclerose Múltipla/genética , Transdução de Sinais/genética , Linfócitos T/imunologia
12.
Biochem Biophys Rep ; 29: 101197, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35028438

RESUMO

Lighting conditions may affect the development of retinal degenerative diseases such as macular degeneration. In this study, to determine whether the lighting environment affects the progression of degeneration of retinal ganglion cells (RGCs), we examined glutamate/aspartate transporter (GLAST) heterozygous (GLAST+/-) mice, a mouse model of normal tension glaucoma. GLAST+/- mice were reared under a 12-h light-dark cycle (Light/Dark) or complete darkness (Dark/Dark) condition after birth. The total RGC number in the Dark/Dark group was significantly decreased compared with the Light/Dark group at 3 weeks old, while the number of osteopontin-positive αRGCs were similar in both groups. At 6 and 12 weeks old, the total RGC number were not significantly different in both conditions. In addition, the retinal function examined by multifocal electroretinogram were similar at 12 weeks old. These results suggest that lighting conditions may regulate the progression of RGC degeneration in some types of glaucoma.

13.
J Diabetes Investig ; 13(4): 628-637, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34693664

RESUMO

AIMS/INTRODUCTION: Inhibition of peroxisome proliferator-activated receptor gamma (PPARγ) phosphorylation mediated by cyclin-dependent kinase 5 (Cdk5) is one of the main mechanisms of action of antidiabetic drugs. In this study, we analyzed the ocular expression and activation of Cdk5 in patients with proliferative diabetic retinopathy (PDR). MATERIALS AND METHODS: The concentrations of PPARγ, Cdk5 and its activating subunit (p35) were determined in the vitreous body of 24 PDR and 63 control eyes by enzyme-linked immunosorbent assay. In addition, the messenger ribonucleic acid and protein expression levels of PPARγ, Cdk5 and p35 were measured in proliferative neovascular membranes from seven PDR eyes and non-neovascular epiretinal membranes from five control eyes by quantitative real-time polymerase chain reaction and immunohistochemical analysis. RESULTS: PPARγ, Cdk5 and p35 concentrations in the vitreous body were significantly higher in the PDR group compared with the control group. There was also a positive significant correlation of Cdk5 with PPARγ and p35 in the PDR group. Furthermore, the messenger ribonucleic acid expression levels of PPARγ, Cdk5 and p35 in proliferative neovascular membranes were significantly higher in the PDR group compared with the control group. Immunostaining showed increased protein expression levels of PPARγ, Cdk5 and p35 in proliferative neovascular membranes in the PDR group compared with the control group. CONCLUSIONS: Cdk5 activation is involved in PDR pathogenesis through PPARγ expression, and inhibition of Cdk5-mediated PPARγ phosphorylation might be a new therapeutic target for treatment of PDR.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Diabetes Mellitus , Retinopatia Diabética , Diabetes Mellitus/metabolismo , Retinopatia Diabética/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Corpo Vítreo/metabolismo
14.
Br J Pharmacol ; 178(22): 4552-4571, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34309010

RESUMO

BACKGROUND AND PURPOSE: Glaucoma, the leading cause of blindness, damages the retinal ganglion cells. Elevated intraocular pressure (IOP) is a high-risk factor for glaucoma, so topical hypotensive drugs are usually used for treatment. Because not all patients do not respond adequately to current treatments, there is a need to identify a new molecular target to reduce IOP. Here, we have assessed the role of P2Y1 receptors in mediating elevated IOP. EXPERIMENTAL APPROACH: P2Y1 receptor agonist was instilled into the eyes of mice, and the IOP changes were measured by a rebound-type tonometer. Expression of P2Y1 receptors was estimated by immunohistochemistry. Ocular function was measured by a multifocal electroretinogram. KEY RESULTS: A single dose of the P2Y1 receptor agonist transiently reduced IOP and such effects were absent in P2Y1 receptor-deficient (P2Y1 KO) mice. P2Y1 receptors were functionally expressed in the ciliary body, trabecular meshwork and Schlemm's canal. Activation of P2Y1 receptors negatively regulated aquaporin 4 (AQP4) function but up-regulated endothelial NOS (eNOS). P2Y1 KO mice showed chronic ocular hypertension regardless of age. P2Y1 KO mice at 3 months old showed no damage to retinal ganglion cells, whereas 12-month-old mice showed a significant loss of these cells and impairment of ocular functions. Damage to retinal ganglion cells was attenuated by chronic administration of an IOP-reducing agent. CONCLUSION AND IMPLICATIONS: Activation of P2Y1 receptors reduced IOP via dual pathways including AQP4 and eNOS. Loss of P2Y1 receptors resulted in glaucomatous optic neuropathy, suggesting that P2Y1 receptors might provide an effective target in the treatment of glaucoma.


Assuntos
Glaucoma , Hipertensão Ocular , Animais , Modelos Animais de Doenças , Glaucoma/tratamento farmacológico , Humanos , Pressão Intraocular , Camundongos , Células Ganglionares da Retina , Transdução de Sinais
15.
Sci Rep ; 10(1): 15709, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973242

RESUMO

Optic nerve injury induces optic nerve degeneration and retinal ganglion cell (RGC) death that lead to visual disturbance. In this study, we examined if topical ripasudil has therapeutic potential in adult mice after optic nerve crush (ONC). Topical ripasudil suppressed ONC-induced phosphorylation of p38 mitogen-activated protein kinase and ameliorated RGC death. In addition, topical ripasudil significantly suppressed the phosphorylation of collapsin response mediator protein 2 and cofilin, and promoted optic nerve regeneration. These results suggest that topical ripasudil promotes RGC protection and optic nerve regeneration by modulating multiple signaling pathways associated with neural cell death, microtubule assembly and actin polymerization.


Assuntos
Axônios/efeitos dos fármacos , Isoquinolinas/uso terapêutico , Regeneração Nervosa/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Traumatismos do Nervo Óptico/tratamento farmacológico , Sulfonamidas/uso terapêutico , Animais , Axônios/fisiologia , Isoquinolinas/administração & dosagem , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Compressão Nervosa , Regeneração Nervosa/fisiologia , Fármacos Neuroprotetores/administração & dosagem , Traumatismos do Nervo Óptico/metabolismo , Traumatismos do Nervo Óptico/fisiopatologia , Fosforilação/efeitos dos fármacos , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/metabolismo , Sulfonamidas/administração & dosagem
16.
Antioxidants (Basel) ; 9(9)2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32947996

RESUMO

Glaucoma is a neurodegenerative disease of the eye, which involves degeneration of retinal ganglion cells (RGCs): the output neurons of the retina to the brain, which with their axons comprise the optic nerve. Recent studies have shown the possible involvement of oxidative stress in the pathogenesis of glaucoma, especially in the subtype of normal tension glaucoma. Basic experiments utilizing rodent and primate models of glaucoma revealed that antioxidants protect RGCs under various pathological conditions including glutamate neurotoxicity and optic nerve injury. These results suggested that existing drugs and food factors may be useful for prevention and hence therapy of glaucoma. In this review, we highlight some therapeutic candidates, particularly those with antioxidant properties, and discuss the therapeutic potential of RGC protection by modulating gene expressions that prevent and ameliorate glaucoma.

17.
Biochem Biophys Res Commun ; 529(4): 943-949, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32819603

RESUMO

Glaucoma is one of the leading causes of blindness characterized by progressive loss of retinal ganglion cells (RGCs) and their axons. We reported that glutamate/aspartate transporter (GLAST) knockout mice showed progressive RGC loss and optic nerve degeneration that are similar to glaucoma. To explore the possibility that rare variants in the EAAT1 gene (the human homolog of GLAST) cause susceptibility to glaucoma, we performed targeted sequencing of EAAT1 in 440 patients with glaucoma and 450 control subjects. We identified 8 rare variants in 20 out of 440 patients, including 4 synonymous and 4 missense variants located at protein coding regions. One of these rare variants (rs117295512) showed significant association with the risk of glaucoma (OR = 10.44, P = 0.005). Furthermore, the allele frequency for loss-of-function EAAT1 variants, pAla169Gly and pAla329Thr, was 5.5 folds higher in the glaucoma (1.1%) compared with the control cohort (0.2%). These findings suggest that these rare variants may contribute to the pathogenesis of glaucoma and that loss-of-function variants in EAAT1 are present in a small number of patients with glaucoma.


Assuntos
Transportador 1 de Aminoácido Excitatório/genética , Glaucoma de Ângulo Aberto/genética , Glaucoma de Baixa Tensão/genética , Mutação de Sentido Incorreto , Mutação Silenciosa , Alelos , Sequência de Aminoácidos , Animais , Estudos de Casos e Controles , Linhagem Celular , Transportador 1 de Aminoácido Excitatório/deficiência , Expressão Gênica , Frequência do Gene , Glaucoma de Ângulo Aberto/metabolismo , Glaucoma de Ângulo Aberto/patologia , Humanos , Pressão Intraocular , Glaucoma de Baixa Tensão/metabolismo , Glaucoma de Baixa Tensão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/patologia , Fatores de Risco , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
18.
J Biol Chem ; 295(19): 6710-6720, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32241915

RESUMO

The DOCK-D (dedicator of cytokinesis D) family proteins are atypical guanine nucleotide exchange factors that regulate Rho GTPase activity. The family consists of Zizimin1 (DOCK9), Zizimin2 (DOCK11), and Zizimin3 (DOCK10). Functions of the DOCK-D family proteins are presently not well-explored, and the role of the DOCK-D family in neuroinflammation is unknown. In this study, we generated three mouse lines in which DOCK9 (DOCK9-/-), DOCK10 (DOCK10-/-), or DOCK11 (DOCK11-/-) had been deleted and examined the phenotypic effects of these gene deletions in MOG35-55 peptide-induced experimental autoimmune encephalomyelitis, an animal model of the neuroinflammatory disorder multiple sclerosis. We found that all the gene knockout lines were healthy and viable. The only phenotype observed under normal conditions was a slightly smaller proportion of B cells in splenocytes in DOCK10-/- mice than in the other mouse lines. We also found that the migration ability of macrophages is impaired in DOCK10-/- and DOCK11-/- mice and that the severity of experimental autoimmune encephalomyelitis was ameliorated only in DOCK10-/- mice. No apparent phenotype was observed for DOCK9-/- mice. Further investigations indicated that lipopolysaccharide stimulation up-regulates DOCK10 expression in microglia and that microglial migration is decreased in DOCK10-/- mice. Up-regulation of C-C motif chemokine ligand 2 (CCL2) expression induced by activation of Toll-like receptor 4 or 9 signaling was reduced in DOCK10-/- astrocytes compared with WT astrocytes. Taken together, our findings suggest that DOCK10 plays a role in innate immunity and neuroinflammation and might represent a potential therapeutic target for managing multiple sclerosis.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/metabolismo , Esclerose Múltipla/metabolismo , Animais , Astrócitos/patologia , Modelos Animais de Doenças , Camundongos , Microglia/patologia , Esclerose Múltipla/patologia
19.
Sci Rep ; 9(1): 14852, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619716

RESUMO

The common marmoset (Callithrix jacchus) is a non-human primate that provides valuable models for neuroscience and aging research due to its anatomical similarities to humans and relatively short lifespan. This study was carried out to examine whether aged marmosets develop glaucoma, as seen in humans. We found that 11% of the aged marmosets presented with glaucoma-like characteristics; this incident rate is very similar to that in humans. Magnetic resonance imaging showed a significant volume loss in the visual cortex, and histological analyses confirmed the degeneration of the lateral geniculate nuclei and visual cortex in the affected marmosets. These marmosets did not have elevated intraocular pressure, but showed an increased oxidative stress level, low cerebrospinal fluid (CSF) pressure, and low brain-derived neurotrophic factor (BDNF) and TrkB expression in the retina, optic nerve head and CSF. Our findings suggest that marmosets have potential to provide useful information for the research of eye and the visual system.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Glaucoma de Baixa Tensão , Disco Óptico/metabolismo , Receptor trkB/metabolismo , Córtex Visual , Envelhecimento , Animais , Callithrix , Modelos Animais de Doenças , Feminino , Glaucoma de Baixa Tensão/metabolismo , Glaucoma de Baixa Tensão/fisiopatologia , Masculino , Retina/metabolismo , Córtex Visual/metabolismo , Córtex Visual/fisiopatologia
20.
Invest Ophthalmol Vis Sci ; 60(12): 3696-3707, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31487370

RESUMO

Purpose: We assess if α retinal ganglion cells (αRGCs) and intrinsically photosensitive retinal ganglion cells (ipRGCs) survive in mouse models of glaucoma. Methods: Two microliters of N-methyl-D-aspartate (NMDA; 1 mM) or PBS were injected intraocularly 7 days before sacrifice. Immunohistochemical analyses of the retina were performed using antibodies against RNA-binding protein with multiple splicing (RBPMS), osteopontin, and melanopsin. Immunohistochemical analyses also were performed in adult mice with glutamate/aspartate transporter (GLAST) deletion (GLAST knockout [KO] mice), a mouse model of normal tension glaucoma. Results: NMDA-induced loss of RBPMS-positive total RGCs was 58.4% ± 0.4% compared to PBS-treated controls, whereas the loss of osteopontin-positive αRGCs was 5.0% ± 0.6% and that of melanopsin-positive ipRGCs was 7.6% ± 1.6%. In GLAST KO mice, the loss of total RGCs was 48.4% ± 0.9% compared to wild-type mice, whereas the loss of αRGCs and ipRGCs was 3.9% ± 0.4% and 9.3% ± 0.5%, respectively. The distribution of survived total RGCs, αRGCs, and ipRGCs was similar regardless of the location of the retina. Conclusions: These results suggest that αRGC and ipRGC are highly tolerant to NMDA-induced neurotoxicity and NTG-like neurodegeneration in GLAST KO mice.


Assuntos
Modelos Animais de Doenças , Agonistas de Aminoácidos Excitatórios/toxicidade , Glaucoma de Baixa Tensão/prevenção & controle , N-Metilaspartato/toxicidade , Disco Óptico/efeitos dos fármacos , Células Ganglionares da Retina/efeitos dos fármacos , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Sobrevivência Celular/fisiologia , Técnica Indireta de Fluorescência para Anticorpo , Injeções Intravítreas , Luz , Glaucoma de Baixa Tensão/metabolismo , Glaucoma de Baixa Tensão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , Disco Óptico/metabolismo , Disco Óptico/efeitos da radiação , Osteopontina/metabolismo , Proteínas de Ligação a RNA/metabolismo , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Degeneração Retiniana/prevenção & controle , Células Ganglionares da Retina/classificação , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA