RESUMEN
Epigenetic modifiers are increasingly being investigated as potential therapeutics to modify and overcome disease phenotypes. Diseases of the nervous system present a particular problem as neurons are postmitotic and demonstrate relatively stable gene expression patterns and chromatin organization. We have explored the ability of epigenetic modifiers to prevent degeneration of rod photoreceptors in a mouse model of retinitis pigmentosa (RP), using rd10 mice of both sexes. The histone modification eraser enzymes lysine demethylase 1 (LSD1) and histone deacetylase 1 (HDAC1) are known to have dramatic effects on the development of rod photoreceptors. In the RP mouse model, inhibitors of these enzymes blocked rod degeneration, preserved vision, and affected the expression of multiple genes including maintenance of rod-specific transcripts and downregulation of those involved in inflammation, gliosis, and cell death. The neuroprotective activity of LSD1 inhibitors includes two pathways. First, through targeting histone modifications, they increase accessibility of chromatin and upregulate neuroprotective genes, such as from the Wnt pathway. We propose that this process is going in rod photoreceptors. Second, through nonhistone targets, they inhibit transcription of inflammatory genes and inflammation. This process is going in microglia, and lack of inflammation keeps rod photoreceptors alive.SIGNIFICANCE STATEMENT Retinal degenerations are a leading cause of vision loss. RP is genetically very heterogeneous, and the multiple pathways leading to cell death are one reason for the slow progress in identifying suitable treatments for patients. Here we demonstrate that inhibition of LSD1and HDAC1 in a mouse model of RP leads to preservation of rod photoreceptors and visual function, retaining of expression of rod-specific genes, and with decreased inflammation, cell death, and Müller cell gliosis. We propose that these epigenetic inhibitors cause more open and accessible chromatin, allowing expression of neuroprotective genes. A second mechanism that allows rod photoreceptor survival is suppression of inflammation by epigenetic inhibitors in microglia. Manipulation of epigenetic modifiers is a new strategy to fight neurodegeneration in RP.
Asunto(s)
Histona Desacetilasa 1/antagonistas & inhibidores , Histona Demetilasas/antagonistas & inhibidores , Degeneración Nerviosa/patología , Células Fotorreceptoras Retinianas Bastones/patología , Retinitis Pigmentosa/metabolismo , Animales , Muerte Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Epigénesis Genética/efectos de los fármacos , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Células Fotorreceptoras Retinianas Bastones/efectos de los fármacos , Células Fotorreceptoras Retinianas Bastones/metabolismo , Retinitis Pigmentosa/patología , Tranilcipromina/farmacologíaRESUMEN
Transcriptome complexity is substantially increased by the use of multiple transcription start sites for a given gene. By utilizing a rod photoreceptor-specific chromatin signature, and the RefSeq database of established transcription start sites, we have identified essentially all known rod photoreceptor genes as well as a group of novel genes that have a high probability of being expressed in rod photoreceptors. Approximately half of these novel rod genes are transcribed into multiple mRNA and/or protein isoforms through alternative transcriptional start sites (ATSS), only one of which has a rod-specific epigenetic signature and gives rise to a rod transcript. This suggests that, during retina development, some genes use ATSS to regulate cell type and temporal specificity, effectively generating a rod transcript from otherwise ubiquitously expressed genes. Biological confirmation of the relationship between epigenetic signatures and gene expression, as well as comparison of our genome-wide chromatin signature maps with available data sets for retina, namely a ChIP-on-Chip study of Polymerase-II (Pol-II) binding sites, ChIP-Seq studies for NRL- and CRX- binding sites and DHS (University of Washington data, available on UCSC mouse Genome Browser as a part of ENCODE project) fully support our hypothesis and together accurately identify and predict an array of new rod transcripts. The same approach was used to identify a number of TSS that are not currently in RefSeq. Biological conformation of the use of some of these TSS suggests that this method will be valuable for exploring the range of transcriptional complexity in many tissues. Comparison of mouse and human genome-wide data indicates that most of these alternate TSS appear to be present in both species, indicating that our approach can be useful for identification of regulatory regions that might play a role in human retinal disease.
Asunto(s)
Biología Computacional , Células Fotorreceptoras Retinianas Bastones/metabolismo , Sitio de Iniciación de la Transcripción , Transcriptoma , Animales , Epigénesis Genética , Ratones , Especificidad de Órganos , Isoformas de Proteínas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Epigenetic modifiers can work in concert with transcription factors to control the transition of cells from proliferating progenitors into quiescent terminally differentiated cells. This transition involves changes in histone methylation and one of the key regulators of this is the H3K4me2/1 histone demethylase LSD1. Here, we show that the highest expression of LSD1 occurs in postmitotic retinal cells during the peak period of rod photoreceptor differentiation. Pharmacological inhibition of LSD1 in retinal explants cultured from PN1 to PN8 had three major effects. It prevented the normal decrease in expression of genes associated with progenitor function, it blocked rod photoreceptor development, and it increased expression of genes associated with other retinal cell types. The maintained expression of progenitor genes was associated with a maintained level of H3K4me2 over the gene and its promoter. Among the genes whose expression was maintained was Hes1, a repressor known to block rod photoreceptor development. The inhibition of rod photoreceptor gene expression occurred in spite of the normal expression of transcription factors CRX and NRL, and the normal accumulation of H3K4me2 marks over the promoter and gene body. We suggest that LSD1 acts in concert with a series of nuclear receptors to modify chromatin structure and repress progenitor genes as well as to inhibit ectopic patterns of gene expression in the differentiating postmitotic retinal cells.
Asunto(s)
Diferenciación Celular/fisiología , Desmetilación , Histona Demetilasas/biosíntesis , Histonas/biosíntesis , Células-Madre Neurales/metabolismo , Células Fotorreceptoras Retinianas Bastones/metabolismo , Animales , Animales Recién Nacidos , Redes Reguladoras de Genes/fisiología , Ratones , Ratones Endogámicos C57BL , Neurogénesis/fisiología , Técnicas de Cultivo de ÓrganosRESUMEN
Signal pathways that reduce the levels of tyrosine-phosphorylated STAT3 (pSTAT3) allow late retinal progenitors to exit the cell cycle and enter a terminal differentiation pathway into rod photoreceptors. In the mouse retina, we previously identified PKC-ß1 and PKC-γ isoforms as essential components of a key signal pathway and IGF-1 as a major extrinsic factor regulating rod formation. In this manuscript, we demonstrate that PKC decreases phosphotyrosine but not phosphoserine on STAT3 in neonatal mouse retinas. Neither IGF-1 nor PMA induced a significant change in the levels of STAT3 or in the levels of the key proteins regulating STAT3 degradation, SOCS3, and PIAS3. Treatment of neonatal mouse retinal explants with sodium orthovanadate inhibited the PKC-mediated reduction in pSTAT3, indicating a role for a phosphatase. Addition of the PTEN inhibitor bpV(phen) to explant cultures treated with IGF-1 or PMA had no effect on the reduction in pSTAT3 levels, but the effect of both IGF-1 and PMA was blocked by a concentration of the inhibitor NSC87877 that is selective for the phosphatases Shp1 and Shp2. Inhibition of Shp1/2 phosphatases was also sufficient to abolish the IGF1-mediated induction of rod photoreceptor differentiation in the retina explant cultures. We conclude that one or both of these phosphatases are key components regulating the formation of rod photoreceptors in mouse retina.
Asunto(s)
Células-Madre Neurales/metabolismo , Neurogénesis , Proteína Tirosina Fosfatasa no Receptora Tipo 11/antagonistas & inhibidores , Proteína Tirosina Fosfatasa no Receptora Tipo 6/antagonistas & inhibidores , Células Fotorreceptoras Retinianas Bastones/metabolismo , Factor de Transcripción STAT3/metabolismo , Animales , Ratones , Ratones Endogámicos C57BL , Células-Madre Neurales/citología , Proteínas Inhibidoras de STAT Activados/metabolismo , Quinolinas/farmacología , Células Fotorreceptoras Retinianas Bastones/citología , Factor de Transcripción STAT3/genética , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/metabolismoRESUMEN
We have used ChIP-seq to map the distribution of two important histone H3 modifications, H3K4me2 and H3K27me3, over the whole genome at multiple time points during late mouse retina development. We merged these data with our previous retina developmental expression profiles and show that there are several epigenetic signatures specific for different functional groups of genes. The main conclusion from our study is that epigenetic signatures defined by H3K4me2 and H3K27me3 can distinguish cell-type specific genes from widespread transcripts and may be reflective of cell specificity during retina maturation. Rod photoreceptor-specific genes have a striking signature, a de novo accumulation of H3K4me2 and a complete absence of H3K27me3. We were able to use this signature in an unbiased search of the whole genome and identified essentially all the known rod photoreceptor genes as well as a group of novel genes that have a high probability of being rod photoreceptor specific. Comparison of our genome-wide chromatin signature maps with available data sets for Polymerase-II (Pol-II) and CRX binding sites and DNase1 Hypersensitive Sites (DHS) for retina shows great agreement. Because our approach is not dependent on high levels of gene expression, it provides a new way of identifying cell type-specific genes, particularly genes that may be involved in retinal diseases.
Asunto(s)
Epigénesis Genética/genética , Regulación del Desarrollo de la Expresión Génica , Retina/citología , Retina/embriología , Células Fotorreceptoras Retinianas Bastones/fisiología , Animales , Estudio de Asociación del Genoma Completo , Ratones , Retina/fisiologíaRESUMEN
Warm ischemia/reperfusion (I/R) is a common clinical problem during liver transplantation and liver resection. Warm ischemia also occurs during trauma and shock. However, there is still no safe and promising strategy for protecting the liver from I/R injury. Signal transducer and activator of transcription 3 (STAT3) is a major immediate response molecule for protecting cell survival. In this study, we first confirmed that a pharmacological STAT3 inhibitor, (E)-2-cyano-3-(3,4-dihydrophenyl)-N-(phenylmethyl)-2-propenamide (AG490), significantly reduced the survival of HepG2 cells, regardless of the serum condition. Furthermore, we created hepatocyte-specific STAT3-deficient mice with the cyclization recombination-locus of X-over P1 (Cre-LoxP) system to study the mechanisms of STAT3 in liver I/R injury. We found that the alanine aminotransferase level was significantly higher in hepatocyte-specific STAT3-deficient mice versus wild-type (WT) mice in a 70% liver I/R injury model. A histopathological examination showed that hepatocyte-specific STAT3-deficient mice suffered more severe damage than WT mice despite similar numbers of polymorphonuclear neutrophils in the 2 groups. These results indicate that endogenous STAT3 signaling in hepatocytes is required for protection of the liver in vitro and in vivo against warm I/R injury. In conclusion, endogenous STAT3 plays an important role in protecting the liver against I/R injury, and STAT3-targeting therapy could be a therapeutic approach to combating liver I/R injury.
Asunto(s)
Hepatocitos/metabolismo , Trasplante de Hígado/métodos , Daño por Reperfusión/metabolismo , Factor de Transcripción STAT3/metabolismo , Alanina Transaminasa/metabolismo , Animales , Proliferación Celular , Supervivencia Celular , Modelos Animales de Enfermedad , Genotipo , Células Hep G2 , Hepatocitos/citología , Hepatocitos/patología , Humanos , Isquemia/patología , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/citología , Fosforilación , Daño por Reperfusión/patología , Factor de Transcripción STAT3/antagonistas & inhibidores , Tirosina/química , Tirfostinos/farmacología , Isquemia TibiaRESUMEN
UNLABELLED: The high rate of mortality and frequent incidence of recurrence associated with hepatocellular carcinoma (HCC) reveal the need for new therapeutic approaches. In this study we evaluated the efficacy of a novel chemoimmunotherapeutic strategy to control HCC and investigated the underlying mechanism that increased the antitumor immune response. We developed a novel orthotopic mouse model of HCC through seeding of tumorigenic hepatocytes from SV40 T antigen (Tag) transgenic MTD2 mice into the livers of syngeneic C57BL/6 mice. These MTD2-derived hepatocytes form Tag-expressing HCC tumors specifically within the liver. This approach provides a platform to test therapeutic strategies and antigen-specific immune-directed therapy in an immunocompetent murine model. Using this model we tested the efficacy of a combination of oral sunitinib, a small molecule multitargeted receptor tyrosine kinase (RTK) inhibitor, and adoptive transfer of tumor antigen-specific CD8(+) T cells to eliminate HCC. Sunitinib treatment alone promoted a transient reduction in tumor size. Sunitinib treatment combined with adoptive transfer of tumor antigen-specific CD8(+) T cells led to elimination of established tumors without recurrence. In vitro studies revealed that HCC growth was inhibited through suppression of STAT3 signaling. In addition, sunitinib treatment of tumor-bearing mice was associated with suppression of STAT3 and a block in T-cell tolerance. CONCLUSION: These findings indicate that sunitinib inhibits HCC tumor growth directly through the STAT3 pathway and prevents tumor antigen-specific CD8(+) T-cell tolerance, thus defining a synergistic chemoimmunotherapeutic approach for HCC.
Asunto(s)
Traslado Adoptivo/métodos , Antineoplásicos/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Indoles/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Pirroles/farmacología , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/inmunología , Adenocarcinoma/patología , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/trasplante , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/patología , Terapia Combinada , Modelos Animales de Enfermedad , Células Hep G2 , Hepatocitos/inmunología , Hepatocitos/trasplante , Humanos , Tolerancia Inmunológica/inmunología , Inmunocompetencia/inmunología , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Factor de Transcripción STAT3/inmunología , Factor de Transcripción STAT3/metabolismo , SunitinibRESUMEN
PURPOSE: Use of microperimetry to compare macular light sensitivity in early and moderate primary open-angle glaucoma (POAG), chronic angle-closure glaucoma (CACG), and normal controls. PATIENTS AND METHODS: A cross-sectional, case-control, comparative study. A total of 126 eyes from 126 subjects, 53 normal eyes, 50 POAG eyes, and 23 CACG eyes were studied. A macular 10° program was performed with MP-1 microperimetry. The mean sensitivities (MS) of the central 2°, 6°, and 10° visual fields were compared among the POAG, CACG, and normal controls. The mean light sensitivities of the four quadrants in the central 6° were also analyzed in each group. RESULTS: The MS of the central 2°, 6°, 10°, and total macular areas in the POAG patients were significantly reduced compared with those for the normal controls (all P < 0.05). The MS of the central 6°, 10°, and total areas, except those at the central 2°, in the CACG patients were significantly reduced. In the central 6°, more severe loss of MS was observed in the inferotemporal quadrant in the POAG group. In the CACG group, the reduction in the MS among the four quadrants was not significantly different (P = 0.623). CONCLUSIONS: Different patterns of macular function damage were identified in both early and moderate stage POAG and in CACG patients.
Asunto(s)
Glaucoma de Ángulo Cerrado/fisiopatología , Glaucoma de Ángulo Abierto/fisiopatología , Retina/fisiopatología , Pruebas del Campo Visual , Campos Visuales/fisiología , Adulto , Femenino , Humanos , Presión Intraocular/fisiología , Luz , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Refracción Ocular/fisiología , Retina/efectos de la radiación , Umbral Sensorial , Agudeza Visual/fisiologíaRESUMEN
The protein kinase C (PKC) family of enzymes regulates cell physiology through phosphorylation of serine and threonine residues of many proteins in most cell types. Here we identify PKC-ß1 and PKC-γ as isoforms that are essential for rod photoreceptor differentiation in mouse retinas. Using ex vivo retinal explants, we found that phorbol ester 12-myristate 13-acetate and insulin-like growth factor 1 (IGF1) induced rod differentiation, as defined by opsin or Crx expression, in a PKC-dependent manner days ahead of rod development in untreated explants. PKC-ß1 and PKC-γ were colocalized with proliferating cell nuclear antigen (PCNA)- and STAT3-positive progenitors through the later differentiation period. Pharmacological or genetic inhibition of either isoform resulted in a partial reduction in the appearance of rods, whereas removing both isoforms resulted in their complete absence. Furthermore, a significant decline of STAT3 tyrosine phosphorylation was observed by activation of PKC, while inhibition of PKC resulted in an increase of phosphorylated STAT3 along with a delayed cell cycle exit of progenitors with prolonged PCNA expression. In adult retinas, IGF1 activates PI-3 kinase (PI3K), but in neonatal retinas its action is identical to the action of an PI3K inhibitor. These data unveil a novel signaling cascade that coordinates and regulates rod differentiation through specific PKC isoforms in mammals.
Asunto(s)
Diferenciación Celular/fisiología , Proteína Quinasa C/metabolismo , Células Fotorreceptoras Retinianas Bastones/enzimología , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Factor I del Crecimiento Similar a la Insulina/farmacología , Isoenzimas/genética , Isoenzimas/metabolismo , Ratones , Ratones Noqueados , Fosforilación/efectos de los fármacos , Proteína Quinasa C/genética , Células Fotorreceptoras Retinianas Bastones/citología , Células Fotorreceptoras Retinianas Bastones/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
We incorporate optics and an ICCD to record the two-dimensional angular optical scattering (TAOS) patterns retrieved from single aerosolized cells. We analyze these patterns by performing autocorrelations and demonstrate that we are able to retrieve cell size from the locations of the secondary maxima. Additional morphological information is contained in the autocorrelation functions and decay rate of the heights of the autocorrelation peaks. We demonstrate these techniques with C6 and Y79 cells, which are readily distinguishable. One key advantage of this methodology is that there is no requirement for antibody and fluorescent labeling molecules.
Asunto(s)
Células/citología , Citofotometría/métodos , Luz , Dispersión de Radiación , Animales , Línea Celular Tumoral , Citofotometría/instrumentación , Rayos Láser , Modelos Teóricos , RatasRESUMEN
Study of retina specific genes would offer insights into retinal diseases and treatment. Based on the information from the gene expression profiles of mouse retinas, we here identified a mitochondria-localized glutamic acid-rich protein (MGARP/OSAP) as one of the highly expressed proteins in retina. Sequence analysis revealed that mouse and rat MGARPs have an extra insertion of four consecutive amino acid repeats at the C-terminus, while other homologues do not. MGARP was demonstrated to be localized to the mitochondria and overexpression of MGARP missing N-terminal region causes severe mitochondrial aggregation, implying an important role of MGARP in maintaining mitochondrial morphology. MGARP is highly expressed in mitochondria-rich layers, including inner segment of the photoreceptor, outer plexiform layer and ganglion cell layers of mouse retina. Far-UV CD spectrum analysis suggested that MGARP exhibits a large area of intrinsic disorder and the unusual position of its Tyr fluorescence suggested that Tyr residues in MGARP might form excimer and exist in an ionized state. These findings implied that MGARP be a good candidate for assembling certain ion channels on mitochondria membrane and have great potential to be involved in retinal energetic metabolism through mitochondria related pathway.
Asunto(s)
Proteínas del Ojo/química , Proteínas del Ojo/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/química , Proteínas Mitocondriales/metabolismo , Retina/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas del Ojo/genética , Células HeLa , Humanos , Proteínas de la Membrana/genética , Ratones , Proteínas Mitocondriales/genética , Datos de Secuencia Molecular , Ratas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Retina/citología , Enfermedades de la Retina/metabolismo , Alineación de Secuencia , Distribución TisularRESUMEN
PURPOSE: To compare the efficacy of topical tetrandrine (an alkaloid isolated from the Chinese medicinal herb Radix Stephania tetrandrae S) and timolol 0.5% ophthalmic solution on lowering the intraocular pressure (IOP) in ocular normotensive and hypertensive rats. METHODS: The experiment was designed as 2 parts. In the first part, normal male Sprague-Dawley rats were divided into 4 groups followed by topical administration once of 0.1%, 0.2%, 0.3% tetrandrine, and 0.5% timolol in the right eye, 0.9% saline was administered once at the opposite eye as control. In the second part, the ocular hypertension model was induced unilaterally in the rats by a diode laser treatment. Twice daily applications of the above drugs were delivered to hypertensive eyes. The control group was administered 0.9% saline. The TonoPen XL tonometer was used to determine the IOP levels. RESULTS: No lowering effect on IOP was detected in the normotensive rats treated with tetrandrine whereas timolol significantly reduced IOP in normotensive eyes. Both tetrandrine and timolol significantly reduced the IOP levels in the hypertensive eyes compared with the levels in the saline-treated groups. All concentrations of tetrandrine used in this study showed significant reduction of IOP in the laser-induced hypertensive eyes. Tetrandrine 0.3% had a similar efficacy as 0.5% timolol in reducing elevated IOP in ocular hypertensive eyes. CONCLUSIONS: This study provides evidence that tetrandrine has a major effect on lowering IOP levels in the ocular hypertension rat model. The functional mechanisms of tetrandrine require further investigation.
Asunto(s)
Antihipertensivos/farmacología , Bencilisoquinolinas/farmacología , Modelos Animales de Enfermedad , Medicamentos Herbarios Chinos/farmacología , Presión Intraocular/efectos de los fármacos , Hipertensión Ocular/tratamiento farmacológico , Administración Tópica , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Timolol/farmacología , Tonometría Ocular , Resultado del TratamientoRESUMEN
The Müller cell is the only glial cell type generated from the retinal neuroepithelium. This cell type controls normal retina homeostasis and has been suggested to play a neuroprotective role. Recent evidence suggests that mammalian Müller cells can de-differentiate and return to a progenitor or stem cell stage following injury or disease. In vivo exploration of the molecular mechanisms of Müller cell differentiation and proliferation will add essential information to manipulate Müller cell functions. Signal transduction pathways that regulate Müller cell responses and activity are a critical part of their cellular machinery. In this study, we focus on mitogen-activated protein kinase (MAPK) signaling pathway during Müller glial cell differentiation and proliferation. We found that both MAPK and STAT3 signaling pathways are present during Müller glial cell development. Ciliary neurotrophic factor (CNTF)-stimulated Müller glial cell proliferation is associated with early developmental stages. Specific inhibition of MAPK phosphorylation significantly reduced the number of Müller glial cells with or without CNTF stimulation. These results suggested that the MAPK signal transduction pathway is important in the formation of Müller glial cells during retina development.
RESUMEN
PURPOSE: The purpose of this study is to compare human serum levels of TH1 and TH2 cytokines between 2 stages of primary open-angle glaucoma (POAG) and nonglaucomatous controls. METHODS: Thirty-two patients with primary POAG and 26 normal control subjects were enrolled into this study. The 32 patients with POAG were divided into 2 subgroups according to their mean defect (MD) with MD better than -12 dB and worse than -12 dB on the visual field. Enzyme-linked immunosorbent assay was used to assay for the levels of TH1 cytokines serum soluble interleukin-2 receptor (sIL-2R), interleukin (IL)-2, IL-12p40, IL-12p70, IL-23, tumor necrosis factor (TNF)-alpha, interferon-gamma, and TH2 cytokines IL-4, IL-6 in the peripheral serum. RESULTS: Patients with mild glaucomatous neuropathy exhibited significant elevations in IL-4 (P<0.0001) and IL-6 (P=0.0302) compared with the controls, whereas higher concentrations of IL-4 (P<0.0001) and IL-6 (P=0.0084) were found in patients with severe glaucomatous neuropathy. The level of IL-12p70 was significantly increased in both the MD >/=12 dB (P<0.0001) and MD <12 dB (P<0.0001) groups. A significant decrease in TNF-alpha levels were observed in MD <12 dB group compared with the controls (P=0.0464), and TNF-alpha levels in MD <12 dB group were lower than MD >/=12 dB group (P=0.0328). No significant differences in serum concentrations of IL-2, sIL-2R IL-12p40, IL-23 and interferon-gamma were found between MD <12 dB group, MD >or=12 dB group, and control group. CONCLUSIONS: Significant alterations of serum TH1 and TH2 cytokines are associated with glaucoma, suggesting the possibility that abnormal immune environments contribute to the glaucomatous neuropathy of POAG.
Asunto(s)
Citocinas/sangre , Glaucoma de Ángulo Abierto/sangre , Enfermedades del Nervio Óptico/sangre , Anciano , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
The mechanistic study of glaucoma pathogenesis has shifted to seeking to understand the effects of immune responses on retinal ganglion cell damage and protection. Cytokines are the hormonal factors that mediate most of the biological effects in both the immune and nonimmune systems. CD4-expressing T helper cells are a major source of cytokine production and regulation. Type 1 helper T (Th1) cells are characterized by the production of proinflammatory cytokines such as interferon-gamma, interleukin (IL)-2, IL-12, IL-23, and tumor necrosis factor-alpha while type 2 helper T (Th2) cells are characterized by the production of IL-4, IL-5, IL-6, and IL-10. The balance of Th1/Th2 cytokine production influences many pathological processes and plays both causative and protective roles in neuron damages. Growing evidence indicates that imbalances of Th1/Th2 cytokine production are involved in neural damage or protection in many neurological diseases. In this review, we discuss the possible roles of Th1/Th2 cytokine production and imbalance of Th1/Th2 cytokines in retina, especially glaucomatous optic neuropathy.
RESUMEN
The mechanistic study of glaucoma pathogenesis has shifted to seeking to understand the effects of immune responses on retinal ganglion cell damage and protection. Cytokines are the hormonal factors that mediate most of the biological effects in both the immune and nonimmune systems. CD4-expressing T helper cells are a major source of cytokine production and regulation. Type 1 helper T (Th1) cells are characterized by the production of proinflammatory cytokines such as interferon-gamma, interleukin (IL)-2, IL-12, IL-23, and tumor necrosis factor-alpha while type 2 helper T (Th2) cells are characterized by the production of IL-4, IL-5, IL-6, and IL-10. The balance of Th1/Th2 cytokine production influences many pathological processes and plays both causative and protective roles in neuronal damage. Growing evidence indicates that imbalances of Th1/Th2 cytokine production are involved in neural damage or protection in many neurological diseases. In this review, we discuss the possible roles of Th1/Th2 cytokine production and imbalance of Th1/Th2 cytokines in retina, especially glaucomatous optic neuropathy.[This corrects the article on p. in vol. .].
RESUMEN
UNLABELLED: Retina explants are widely used as a model of neural development. To define the molecular basis of differences between the development of retina in vivo and in vitro during the early postnatal period, we carried out a series of microarray comparisons using mouse retinas. About 75% of 8,880 expressed genes from retina explants kept the same expression volume and pattern as the retina in vivo. Fewer than 6% of the total gene population was changed at two consecutive time points, and only about 1% genes showed more than a threefold change at any time point studied. Functional Gene Ontology (GO) mapping for both changed and unchanged genes showed similar distribution patterns, except that more genes were changed in the GO clusters of response to stimuli and carbohydrate metabolism. Three distinct expression patterns of genes preferentially expressed in rod photoreceptors were observed in the retina explants. Some genes showed a lag in increased expression, some showed no change, and some continued to have a reduced level of expression. An early downregulation of cyclin D1 in the explanted retina might explain the reduction in numbers of precursors in explanted retina and suggests that external factors are required for maintenance of cyclin D1. The global view of gene profiles presented in this study will help define the molecular changes in retina explants over time and will provide criteria to define future changes that improve this model system. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12177-008-9009-z) contains supplementary material, which is available to authorized users.
RESUMEN
Age-related macular degeneration (AMD), the most common cause of irreversible vision loss in individuals aged older than 50 years, is classified as either wet (neovascular) or dry (nonneovascular). Inherited variation in the complement factor H gene is a major risk factor for drusen in dry AMD. Here we report that a single-nucleotide polymorphism in the promoter region of HTRA1, a serine protease gene on chromosome 10q26, is a major genetic risk factor for wet AMD. A whole-genome association mapping strategy was applied to a Chinese population, yielding a P value of <10(-11). Individuals with the risk-associated genotype were estimated to have a likelihood of developing wet AMD 10 times that of individuals with the wild-type genotype.
Asunto(s)
Predisposición Genética a la Enfermedad , Degeneración Macular/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Serina Endopeptidasas/genética , Anciano , Anciano de 80 o más Años , Envejecimiento , Pueblo Asiatico/genética , Inmunoprecipitación de Cromatina , Cromosomas Humanos Par 10/genética , Femenino , Genotipo , Células HeLa , Serina Peptidasa A1 que Requiere Temperaturas Altas , Humanos , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Neovascularización Retiniana , Factor de Respuesta Sérica/metabolismo , Factor de Transcripción AP-2/metabolismoRESUMEN
BACKGROUND: Between embryonic day 12 and postnatal day 21, six major neuronal and one glia cell type are generated from multipotential progenitors in a characteristic sequence during mouse retina development. We investigated expression patterns of retina transcripts during the major embryonic and postnatal developmental stages to provide a systematic view of normal mouse retina development, RESULTS: A tissue-specific cDNA microarray was generated using a set of sequence non-redundant EST clones collected from mouse retina. Eleven stages of mouse retina, from embryonic day 12.5 (El2.5) to postnatal day 21 (PN21), were collected for RNA isolation. Non-amplified RNAs were labeled for microarray experiments and three sets of data were analyzed for significance, hierarchical relationships, and functional clustering. Six individual gene expression clusters were identified based on expression patterns of transcripts through retina development. Two developmental phases were clearly divided with postnatal day 5 (PN5) as a separate cluster. Among 4,180 transcripts that changed significantly during development, approximately 2/3 of the genes were expressed at high levels up until PN5 and then declined whereas the other 1/3 of the genes increased expression from PN5 and remained at the higher levels until at least PN21. Less than 1% of the genes observed showed a peak of expression between the two phases. Among the later increased population, only about 40% genes are correlated with rod photoreceptors, indicating that multiple cell types contributed to gene expression in this phase. Within the same functional classes, however, different gene populations were expressed in distinct developmental phases. A correlation coefficient analysis of gene expression during retina development between previous SAGE studies and this study was also carried out. CONCLUSION: This study provides a complementary genome-wide view of common gene dynamics and a broad molecular classification of mouse retina development. Different genes in the same functional clusters are expressed in the different developmental stages, suggesting that cells might change gene expression profiles from differentiation to maturation stages. We propose that large-scale changes in gene regulation during development are necessary for the final maturation and function of the retina.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Retina/embriología , Retina/metabolismo , Animales , Animales Recién Nacidos , Desarrollo Embrionario , Proteínas del Ojo/clasificación , Proteínas del Ojo/metabolismo , Perfilación de la Expresión Génica/métodos , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , Especificidad de Órganos , Retina/crecimiento & desarrollo , Células Fotorreceptoras Retinianas Bastones/metabolismoRESUMEN
BACKGROUND: Pigment epithelium derived factor (PEDF), a member of the serpin family, regulates cell proliferation, promotes survival of neurons, and blocks growth of new blood vessels in mammals. Defining the molecular phylogeny of PEDF by bioinformatic analysis is one approach to understanding the link between its gene structure and its function in these biological processes. RESULTS: From a comprehensive search of available DNA databases we identified a single PEDF gene in all vertebrate species examined. These included four mammalian and six non-mammalian vertebrate species in which PEDF had not previously been described. A five gene cluster around PEDF was found in an approximate 100 kb region in mammals, birds, and amphibians. In ray-finned fish these genes are scattered over three chromosomes although only one PEDF gene was consistently found. The PEDF gene is absent in invertebrates including Drosophila melanogaster (D. melanogaster), Caenorhabditis elegans (C. elegans), and sea squirt (C. intestinalis). The PEDF gene is transcribed in all vertebrate phyla, suggesting it is biologically active throughout vertebrate evolution. The multiple actions of PEDF are likely conserved in evolution since it has the same gene structure across phyla, although the size of the gene ranges from 48.3 kb in X. tropicalis to 2.9 kb in fugu, with human PEDF at a size of 15.6 kb. A strong similarity in the proximal 200 bp of the PEDF promoter in mammals suggests the existence of a possible regulatory region across phyla. Using a non-synonymous/synonymous substitution rate ratio we show that mammalian and fish PEDFs have similar ratios of <0.13, reflecting a strong purifying selection of PEDF gene. A large number of repetitive transposable elements of the SINE and LINE class were found with random distribution in both the promoter and introns of mammalian PEDF. CONCLUSION: The PEDF gene first appears in vertebrates and our studies suggest that the regulation and biological actions of this gene are preserved across vertebrates. This comprehensive analysis of the PEDF gene across phyla provides new information that will aid further characterization of common functional motifs of this serpin in biological processes.