Browsing by Subject "Axotomy"

Now showing 1 - 11 of 11
  • Thumbnail Image
    Publication
    Open Access
    7,8-Dihydroxiflavone protects adult rat axotomized retinal ganglion cells through MAPK/ERK and PI3K/AKT activation
    (MDPI, 2021-10-08) Galindo Romero, Caridad; Vidal-Villegas, Beatriz; Asís-Martínez, Javier; Lucas Ruiz, Fernando; Gallego Ortega, Alejandro; Vidal Sanz, Manuel; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultad de Óptica y Optometría
    We analyze the 7,8-dihydroxyflavone (DHF)/TrkB signaling activation of two main intracellular pathways, mitogen-activated protein kinase (MAPK)/ERK and phosphatidylinositol 3 kinase (PI3K)/AKT, in the neuroprotection of axotomized retinal ganglion cells (RGCs). Methods: Adult albino Sprague-Dawley rats received left intraorbital optic nerve transection (IONT) and were divided in two groups. One group received daily intraperitoneal DHF (5 mg/kg) and another vehicle (1%DMSO in 0.9%NaCl) from one day before IONT until processing. Additional intact rats were employed as control (n = 4). At 1, 3 or 7 days (d) after IONT, phosphorylated (p)AKT, p-MAPK, and non-phosphorylated AKT and MAPK expression levels were analyzed in the retina by Western blotting (n = 4/group). Radial sections were also immunodetected for the above-mentioned proteins, and for Brn3a and vimentin to identify RGCs and Müller cells (MCs), respectively (n = 3/group). Results: IONT induced increased levels of p-MAPK and MAPK at 3d in DHF- or vehicle-treated retinas and at 7d in DHF-treated retinas. IONT induced a fast decrease in AKT in retinas treated with DHF or vehicle, with higher levels of phosphorylation in DHF-treated retinas at 7d. In intact retinas and vehicle-treated groups, no p-MAPK or MAPK expression in RGCs was observed. In DHF- treated retinas p-MAPK and MAPK were expressed in the ganglion cell layer and in the RGC nuclei 3 and 7d after IONT. AKT was observed in intact and axotomized RGCs, but the signal intensity of p-AKT was stronger in DHF-treated retinas. Finally, MCs expressed higher quantities of both MAPK and AKT at 3d in both DHF- and vehicle-treated retinas, and at 7d the phosphorylation of p-MAPK was higher in DHF-treated groups. Conclusions: Phosphorylation and increased levels of AKT and MAPK through MCs and RGCs in retinas after DHF-treatment may be responsible for the increased and long-lasting RGC protection afforded by DHF after IONT.
  • Thumbnail Image
    Publication
    Restricted
    Brain derived neurotrophic factor maintains Brn3a expression in axotomized rat retinal ganglion cells
    (Elsevier, 2009-08-16) Sánchez Migallón, María del Cielo; Nadal-Nicolás, Francisco Manuel; Jiménez López, Manuel; Sobrado Calvo, Paloma; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    The transcription factor Brn3a has been reported to be a good marker for adult rat retinal ganglion cells in control and injured retinas. However, it is still unclear if Brn3a expression declines progressively by the injury itself or otherwise its expression is maintained in retinal ganglion cells that, though being injured, are still alive, as might occur when assessing neuroprotective therapies. Therefore, we have automatically quantified the whole population of surviving Brn3a positive retinal ganglion cells in retinas subjected to intraorbital optic nerve transection and treated with either brain derived neurotrophic factor or vehicle. Brain derived neurotrophic factor is known to delay retinal ganglion cell death after axotomy. Thus, comparison of both groups would inform of the suitability of Brn3a as a retinal ganglion cell marker when testing neuroprotective molecules. As internal control, retinal ganglion cells were, as well, identified in all retinas by retrogradely tracing them with fluorogold. Our data show that at all the analyzed times post-lesion, the numbers of Brn3a positive retinal ganglion cells and of fluorogold positive retinal ganglion cells are significantly higher in the brain derived neurotrophic factor-treated retinas compared to the vehicle-treated ones. Moreover, detailed isodensity maps of the surviving Brn3a positive retinal ganglion cells show that a single injection of brain derived neurotrophic factor protects retinal ganglion cells throughout the entire retina. In conclusion, Brn3a is a reliable retinal ganglion cell marker that can be used to accurately measure the potential effect of a given neuroprotective therapy.
  • Thumbnail Image
    Publication
    Open Access
    Comparison of retinal nerve fiber layer thinning and retinal ganglion cell loss after optic nerve transection in adult albino rats
    (Association for Research in Vision and Ophthalmology., 2015-07-15) Rovere, Giuseppe; Nadal-Nicolás, Francisco Manuel; Agudo Barriuso, Marta; Sobrado Calvo, Paloma; Nieto López, Leticia; Nucci, Carlo; Villegas Pérez, Maria Paz; Vidal Sanz, Manuel; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    PURPOSE. We compared the time-course and magnitude of retinal nerve fiber layer (RNFL) thinning with that of retinal ganglion cell (RGC) loss after intraorbital optic nerve transection (IONT) in adult rats. METHODS. At 3, 7, 12, or 21 days, or 1, 2, or 4 months after ONT, the retinas were imaged with spectral-domain optical coherence tomography (SD-OCT) using the circular-peripapillary scan and volume scan raster pattern (61 horizontal sections equally spaced) both centered in the optic nerve. In all sections, the RNFL and retinal thickness were measured to obtain the total values of the peripapillary scan and the values of three concentric sectors (400, 1200, and 2400 lm in diameter) from the volume scan. After SD-OCT, retinas were dissected and immunoreacted for Brn3a and neurofilaments (pNFH) to identify RGCs and their intraretinal axons, respectively. Total numbers of RGCs were quantified. RESULTS. Thinning of the RNFL was first observed at 12 days in peripapillary scan (10% decrease) and progressed up to 4 months (72% decrease). The volume scan showed transient RNFL swelling in central and medial sectors at 3, 7, and 12 days followed by progressive significant thinning first observed at 21 days (central sector, 30%; medial sector, 40%) and 12 days (peripheral sector, 15%), respectively. Following IONT, Brn3aþ RGCs decreased to approximately 80%, 52%, 17%, 9%, 5%, 3%, and 2% at 3, 7, 12, 21 days, and at 1, 2, and 4 months, respectively. Retinal ganglion cell axon immunodetection decreased from 12 days onwards. CONCLUSIONS. After IONT, RGC death is more severe and precedes thinning of the RNFL.
  • Thumbnail Image
    Publication
    Open Access
    Displaced retinal ganglion cells in albino and pigmented rats
    (Frontiers Media , 2014-10-06) Nadal-Nicolás, Francisco Manuel; Salinas Navarro, Manuel Ángel; Jiménez López, Manuel; Sobrado Calvo, Paloma; Villegas Pérez, Maria Paz; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    We have studied in parallel the population of displaced retinal ganglion cells (dRGCs) and normally placed (orthotopic RGCs, oRGCs) in albino and pigmented rats. Using retrograde tracing from the optic nerve, from both superior colliculi (SC) or from the ipsilateral SC in conjunction with Brn3 and melanopsin immunodetection, we report for the first time their total number and topography as well as the number and distribution of those dRGCs and oRGCs that project ipsi- or contralaterally and/or that express any of the three Brn3 isoforms or melanopsin. The total number of RGCs (oRGCs+dRGCs) is 84,706 ± 1249 in albino and 90,440 ± 2236 in pigmented, out of which 2383 and 2428 are melanopsin positive (m-RGCs), respectively. Regarding dRGCs: i/ albino rats have a significantly lower number of dRGCs than pigmented animals (0.5% of the total number of RGCs vs. 2.5%, respectively), ii/ dRGCs project massively to the contralateral SC, iii/ the percentage of ipsilaterality is higher for dRGCs than for oRGCs, iv/ a higher proportion of ipsilateral dRGCs is observed in albino than pigmented animals, v/ dRGC topography is very specific, they predominate in the equatorial temporal retina, being densest where the oRGCs are densest, vi/ Brn3a detects all dRGCs except half of the ipsilateral ones and those that express melanopsin, vii/ the proportion of dRGCs that express Brn3b or Brn3c is slightly lower than in the oRGC population, viii/ a higher percentage of dRGCs (13% albino, 9% pigmented) than oRGCs (2.6%) express melanopsin, ix/ few m-RGCs (displaced and orthotopic) project to the ipsilateral SC, x/ the topography of m-dRGCs does not resemble the general distribution of dRGCs, xi/ The soma size in m-oRGCs ranges from 10 to 21 μm and in m-dRGCs from 8 to 15 μm, xii/ oRGCs and dRGCs have the same susceptibility to axonal injury and ocular hypertension. Although the role of mammalian dRGCs remains to be determined, our data suggest that they are not misplaced by an ontogenic mistake.
  • Thumbnail Image
    Publication
    Open Access
    Electron microscopic study of sprouting dendrites in the ciliary ganglia of cat and monkey (Macaca fascicularís) following pre- and post-ganglionic axotomy
    (Murcia : F. Hernández, 1997) Zhang, Y.L.; Tan, C.K.; Wong, W. C.
    The present paper reports the ultrastructure of dendritic sprouting and formation of associated synapses in the ciliary ganglion of cat and monkey induced by pre- and post-ganglionic axotomy. In both series of experiments, sprouting dendrites were observed mostly at 3-5 days postoperatively; such profiles were identified by their dense packing of mitochondria and glycogen-like granules. In longitudinal section, such profiles appeared as expanded extensions from the normal-looking dendritic trunks. None were observed to arise directly from the neuronal soma. After preganglionic nerve section, the cross-sectional diameters of such profiles measured 2.211 .O pm (range: 0.9-6.2 pm) in cat and 2.4I0.7 y m (range: 0.9-5.5 pm) in monkey. After postganglionic nerve section, the crosssectional diameters of such profiles measured 2.110.7 pm (range: 0.8-4.5 pm) in cat and 2.811.4 pm (range: 1.1-7 .O p m) in monkey. After preganglionic axotomy, in both cat and monkey, the axon terminals began to degenerate at 3 days postoperatively and disappeared by 5 days postoperatively. However, at later postoperative survival periods, the axon terminals reappeared and were observed to make synaptic contacts with the sprouting dendrites. Some of the sprouting dendrites were observed to degenerate, some as early as 3 days postoperatively; such profiles did not appear to have any synapse on them. After postganglionic axotomy, such sprouting dendritic profiles were also observed to make synaptic contacts with axon terminals; some were only closely associated with profiles filled with synaptic vesicles. The results thus suggest that through the formation of new synapses, sprouting of dendrites may have a role to play in neuronal survival after axotomy.
  • Thumbnail Image
    Publication
    Open Access
    Human Wharton’s jelly mesenchymal stem cells protect axotomized rat retinal ganglion cells via secretion of antiinflammatory and neurotrophic factors
    (Springer Nature, 2018-11-02) Millán-Rivero, J.E; Sobrado-Calvo, P.; Blanquer, M.; Moraleda, J.M.; Vidal-Sanz, M.A.; Agudo-Barriuso, M.; Nadal-Nicolás, Francisco Manuel; García Bernal, David; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica
    El artículo muestra los resultados del estudio de la capacidad neuroprotectora de las células mesenquimales derivadas de cordón umbilical (CMCU) sobre las células ganglionares de la retina (CGR) tras axotomía por aplastamiento del nervio óptico. Se quería saber, no solo si existía efecto neuroprotector, si no también si el trasplante de estas células tenía algún efecto tóxico en retina, y dilucidar los posibles mecanismos a través de los cuales se produjeran estos efectos. En una primera parte del estudio, demostramos que las CMCU suprimen la proliferación de células T e inhiben la producción de citocinas proinflamatorias, confirmando que su efecto inmunomodulador es mayor que el de las células mesequimales derivadas de médula ósea. También observamos que tras la inyección intravítrea de CMCU, estas se integran en la capa de CGR, extendiéndose por toda la retina, observándose una reducción importante a los 30 días, y no observando la formación de tumoración. En retinas intactas no se observó efecto tóxico sobre las CGR, si bien sí hubo alteración de la arquitectura de la retina por la infiltración masiva de células Iba1+ (microglía o macrófagos), que se reduce mucho a los 30 días y da señales de restauración de dicha arquitectura. Por otra parte, en retinas axotomizadas se encontró un aumento muy importante de la supervivencia de las CGR de los animales tratados.
  • Thumbnail Image
    Publication
    Open Access
    Metabolomic changes in the rat retina after optic nerve crush
    (Association for Research in Vision and Ophthalmology, 2013-06-21) Agudo Barriuso, Marta; Lahoz, Agustín; Nadal-Nicolás, Francisco Manuel; Sobrado Calvo, Paloma; Piquer Gil, Marina; Díaz Llopis, Manuel; Vidal Sanz, Manuel; Mullor, José L.; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    Purpose: To identify metabolic pathways and metabolites affected by optic nerve crush that can act as predictors of the disease or therapeutic targets. Methods: The left optic nerve of adult rats was intraorbitally crushed and retinas were dissected 24 hours or 14 days after the lesion (n = 10 per group). Metabolic profiling analysis was carried out by Metabolon, Inc. A total of 195 metabolites were unambiguously detected. Data were normalized and the regulated metabolites were identified after comparing the different conditions. Metabolite concentration changes were analyzed using single and multivariate statistical analysis to detect discriminatory metabolites. Functional clustering and meta-analysis of the regulated metabolites was run through the Metacore platform. Results: Comparison of 24 hours versus control, 14 days versus control samples, and 24 hours versus 14 days identified 9, 19, and 32 regulated metabolites, respectively. Single and multivariate analysis identified a total of 27 and 36 metabolites to discriminate between control and 14 days and between 24 hours and 14 days, respectively. Enrichment analysis showed alterations in the amino acid, carbohydrate, and lipid metabolism, which were further linked to translation, oxidative stress, energy (glucose and tricarboxylic acid cycle), and apoptosis through ceramide pathways. Conclusions: Our analysis differentiates a set of metabolites that clearly discriminate control and early-injury samples from late-injury samples. These metabolites could have potential use as diagnostic molecules.
  • Thumbnail Image
    Publication
    Open Access
    Nerve fibre layer degeneration and retinal ganglion cell loss long term after optic nerve crush or transection in adult mice
    (Elsevier, 2018-02-13) Sánchez-Migallón Carreras, María del Cielo; Valiente Soriano, Francisco Javier; Salinas Navarro, Manuel Ángel; Nadal-Nicolás, Francisco Manuel; Jiménez-López, M.; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultad de Medicina
    We have investigated the long term effects of two different models of unilateral optic nerve (ON) lesion on retinal ganglion cells (RGCs) and their axons, in the injured and contralateral retinas of adult albino mice. Intact animals were used as controls. The left ON was intraorbitally crushed or transected at 0.5 mm from the optic disk and both retinas were analyzed at 2, 3, 5, 7, 14, 30, 45 or 90 days after injury. RGCs were immunoidentified with anti-Brn3a, and their axons with anti-highly phosphorylated axonal neurofilament subunit H (pNFH). After both lesions, RGC death in the injured retinas is first significant at day 3, and progresses quickly up to 7 days slowing down till 90 days. In the same retinas, the anatomical loss of RGC axons is not evident until day 30. However, by two days after both lesions there are changes in the expression pattern of pNFH: axonal beads, axonal club- or bulb-like formations, and pNFH+RGC somas. The number of pNFH+RGC somata peak at day 5 after either lesion and is significantly higher than in intact retinas at all time points. pNFH+RGC somata are distributed across the retina, in accordance with the pattern of RGC death which is diffuse and homogenous. In the contralateral retinas there is no RGC loss, but there are few pNFH+RGCs from day 2 to day 90. In conclusion, in albino mice, axotomy-induced RGC death precedes the loss of their intraretinal axons and occurs in two phases, a rapid and a slower, but steady, one. Injured retinas show similar changes in the pattern of pNFH expression and a comparable course of RGC loss
  • Thumbnail Image
    Publication
    Open Access
    Restorative potential of ciliary body cells in a retinal ganglion cell degeneration model
    (Nature Research, 2025-05-03) Fernández-Nogales, Marta; Herrera, Macarena; Herrera, Eloisa ; Lucas Ruiz, Fernando; Valiente Soriano, Francisco Javier; Nadal-Nicolás, Francisco Manuel; Agudo Barriuso, Marta; Lucas Ruiz, Fernando; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    The ciliary body (CB) has been proposed as a niche of neural stem cells because, in vitro, cells from this area are able to form neurospheres, proliferate and differentiate. Here, we explore the potential of CB cells to differentiate and replace degenerated retinal ganglion cells (RGCs) in vivo. CB cells and cells from the subventricular zone (SVZ) were isolated from adult or postnatal C57BL/6Tg(CAG-EGFP) mice, respectively, and intravitreally injected into intact retinas, immediately after optic nerve crush or 45 days after the lesion of adult C57/BL/6 mice. Retinas were analysed in whole mounts or cross sections at different time points. Controls were matched untreated retinas. Neither cell type caused gliosis or toxicity when injected into intact retinas. When CB or SVZ cells were injected right after axotomy, they formed an epimembrane without integrating in the retina. However, when CB cells were administered in retinas depleted of RGCs, they integrated into the ganglion cell layer and expressed RGC and neuronal markers. Although SVZ cells were also able to integrate into RGC depleted retinas they did so more slowly than CB cells. These results shed light in the long-standing question of whether cells in the CB have the potential to transdifferentiate in vivo and point to the CB as a suitable source of cells that could be used in cell-replacement therapies for neurodegenerative diseases of the retina.
  • Thumbnail Image
    Publication
    Open Access
    Shared and differential retinal responses against optic nerve injury and ocular hypertension
    (Frontiers Media SA., 2017-04-26) Vidal Sanz, Manuel; Galindo Romero, Caridad; Valiente-Soriano, Francisco J.; Nadal-Nicolás, Francisco Manuel; Ortín-Martínez, Arturo; Rovere, Giuseppe; Salinas Navarro, Manuel Ángel; Lucas Ruiz, Fernando; Sánchez-Migallón, María C.; Sobrado Calvo, Paloma; Avilés Trigueros, Marcelino; Villegas Pérez, Maria Paz; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultad de Medicina
    Glaucoma, one of the leading causes of blindness worldwide, affects primarily retinal ganglion cells (RGCs) and their axons. The pathophysiology of glaucoma is not fully understood, but it is currently believed that damage to RGC axons at the optic nerve head plays a major role. Rodent models to study glaucoma include those that mimic either ocular hypertension or optic nerve injury. Here we review the anatomical loss of the general population of RGCs (that express Brn3a; Brn3a+RGCs) and of the intrinsically photosensitive RGCs (that express melanopsin; m+RGCs) after chronic (LP-OHT) or acute (A-OHT) ocular hypertension and after complete intraorbital optic nerve transection (ONT) or crush (ONC). Our studies show that all of these insults trigger RGC death. Compared to Brn3a+RGCs, m+RGCs are more resilient to ONT, ONC, and A-OHT but not to LP-OHT. There are differences in the course of RGC loss both between these RGC types and among injuries. An important difference between the damage caused by ocular hypertension or optic nerve injury appears in the outer retina. Both axotomy and LP-OHT induce selective loss of RGCs but LP-OHT also induces a protracted loss of cone photoreceptors. This review outlines our current understanding of the anatomical changes occurring in rodent models of glaucoma and discusses the advantages of each one and their translational value.
  • Thumbnail Image
    Publication
    Restricted
    Systemic treatment with 7,8-Dihydroxiflavone activates TtkB and affords protection of two different retinal ganglion cell populations against axotomy in adult rats
    (Elsevier, 2021-07-08) Vidal-Villegas, Beatriz; Di Pierdomenico, Johnny; Gallego Ortega, Alejandro; Galindo Romero, Caridad; Martínez-de-la-Casa, José M.; García-Feijoo, Julián; Villegas Pérez, Maria Paz; Vidal Sanz, Manuel; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultad de Óptica y Optometría
    Purpose: To analyze responses of different RGC populations to left intraorbital optic nerve transection (IONT) and intraperitoneal (i.p.) treatment with 7,8-Dihydroxyflavone (DHF), a potent selective TrkB agonist. Methods: Adult albino Sprague-Dawley rats received, following IONT, daily i.p. injections of vehicle (1%DMSO in 0.9%NaCl) or DHF. Group-1 (n = 58) assessed at 7days (d) the optimal DHF amount (1–25 mg/kg). Group-2, using freshly dissected naïve or treated retinas (n = 28), investigated if DHF treatment was associated with TrkB activation using Western-blotting at 1, 3 or 7d. Group-3 (n = 98) explored persistence of protection and was analyzed at survival intervals from 7 to 60d after IONT. Groups 2–3 received daily i.p. vehicle or DHF (5 mg/kg). Retinal wholemounts were immunolabelled for Brn3a and melanopsin to identify Brn3a+RGCs and m+RGCs, respectively. Results: Optimal neuroprotection was achieved with 5 mg/kg DHF and resulted in TrkB phosphorylation. The percentage of surviving Brn3a+RGCs in vehicle treated rats was 60, 28, 18, 13, 12 or 8% of the original value at 7, 10, 14, 21, 30 or 60d, respectively, while in DHF treated retinas was 94, 70, 64, 17, 10 or 9% at the same time intervals. The percentages of m+RGCs diminished by 7d–13%, and recovered by 14d–38% in vehicle-treated and to 48% in DHF-treated retinas, without further variations. Conclusions: DHF neuroprotects Brn3a + RGCs and m + RGCs; its protective effects for Brn3a+RGCs are maximal at 7 days but still significant at 21d, whereas for m+RGCs neuroprotection was significant at 14d and permanent.