Heavy Metals and Trace Elements in Human Breast Milk from Industrial/Mining and Agricultural Zones of Southeastern Spain

© 2021 The authors. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the published version of a published work that appeared in final form in International Journal of Environmental Research and Public Health.Human breast milk is the most complete foodstuff for infants but can also be a potential source of exposure to toxic chemicals. The aim of this study was to assess the levels of metal pollution in the breast milk of women living in agricultural and industrial/mining areas of the Region of Murcia (Spain) that are well known for their cases of environmental pollution. Human milk samples were collected from 50 mothers and inorganic contaminants were analyzed using inductively coupled plasma mass spectrometry (ICP‐MS). The mean or maximum concentrations of the different inorganic elements analyzed in breast milk, with the exception of manganese, exceeded the maximum limits established by the WHO and could constitute a high risk for pregnant mothers and their children. The breast milk of women living in the industrial/mining zone presented the highest levels of aluminum, zinc, arsenic, lead, mercury and nickel. On the contrary, the highest concentrations of manganese, chromium and iron were determined in the milk of women living in the agricultural zone. These results suggested and confirmed different profiles of environmental contamination of these areas

Insulin-like growth factor I (IGF-I)-induced chronic gliosis and retinal stress lead to neurodegeneration in a mouse model of retinopathy

Insulin-like growth factor I (IGF-I) exerts multiple effects on different retinal cell types in both physiological and pathological conditions. Despite the growth factor's extensively described neuroprotective actions, transgenic mice with increased intraocular levels of IGF-I showed progressive impairment of electroretinographic amplitudes up to complete loss of response, with loss of photoreceptors and bipolar, ganglion, and amacrine neurons. Neurodegeneration was preceded by the overexpression of genes related to retinal stress, acute-phase response, and gliosis, suggesting that IGF-I altered normal retinal homeostasis. Indeed, gliosis and microgliosis were present from an early age in transgenic mice, before other alterations occurred, and were accompanied by signs of oxidative stress and impaired glutamate recycling. Older mice also showed overproduction of pro-inflammatory cytokines. Our results suggest that, when chronically increased, intraocular IGF-I is responsible for the induction of deleterious cellular processes that can lead to neurodegeneration, and they highlight the importance that this growth factor may have in the pathogenesis of conditions such as ischemic or diabetic retinopathy

Whole body correction of mucopolysaccharidosis IIIA by intracerebrospinal fluid gene therapy

For most lysosomal storage diseases (LSDs) affecting the CNS, there is currently no cure. The BBB, which limits the bioavailability of drugs administered systemically, and the short half-life of lysosomal enzymes, hamper the development of effective therapies. Mucopolysaccharidosis type IIIA (MPS IIIA) is an autosomic recessive LSD caused by a deficiency in sulfamidase, a sulfatase involved in the stepwise degradation of glycosaminoglycan (GAG) heparan sulfate. Here, we demonstrate that intracerebrospinal fluid (intra-CSF) administration of serotype 9 adenoassociated viral vectors (AAV9s) encoding sulfamidase corrects both CNS and somatic pathology in MPS IIIA mice. Following vector administration, enzymatic activity increased throughout the brain and in serum, leading to whole body correction of GAG accumulation and lysosomal pathology, normalization of behavioral deficits, and prolonged survival. To test this strategy in a larger animal, we treated beagle dogs using intracisternal or intracerebroventricular delivery. Administration of sulfamidase-encoding AAV9 resulted in transgenic expression throughout the CNS and liver and increased sulfamidase activity in CSF. High-titer serum antibodies against AAV9 only partially blocked CSF-mediated gene transfer to the brains of dogs. Consistently, anti-AAV antibody titers were lower in CSF than in serum collected from healthy and MPS IIIA-affected children. These results support the clinical translation of this approach for the treatment of MPS IIIA and other LSDs with CNS involvement

FGF21 gene therapy as treatment for obesity and insulin resistance

Prevalence of type 2 diabetes (T2D) and obesity is increasing worldwide. Currently available therapies are not suited for all patients in the heterogeneous obese/T2D population, hence the need for novel treatments. Fibroblast growth factor 21 (FGF21) is considered a promising therapeutic agent for T2D/obesity. Native FGF21 has, however, poor pharmacokinetic properties, making gene therapy an attractive strategy to achieve sustained circulating levels of this protein. Here, adeno-associated viral vectors (AAV) were used to genetically engineer liver, adipose tissue, or skeletal muscle to secrete FGF21. Treatment of animals under long-term high-fat diet feeding or of ob/ob mice resulted in marked reductions in body weight, adipose tissue hypertrophy and inflammation, hepatic steatosis, inflammation and fibrosis, and insulin resistance for > 1 year. This therapeutic effect was achieved in the absence of side effects despite continuously elevated serum FGF21. Furthermore, FGF21 overproduction in healthy animals fed a standard diet prevented the increase in weight and insulin resistance associated with aging. Our study underscores the potential of FGF21 gene therapy to treat obesity, insulin resistance, and T2D.This work was supported by grants from Ministerio de Economía y Competi- tividad (MINECO) and FEDER, Plan Nacional I+D+I (SAF2014-54866R), andGeneralitat de Catalunya (2014SGR1669and ICREA Academia Award to F.B.), Spain, from the European Commission (MYOCURE, PHC-14-2015 667751) and the European Foundation for the Study of Diabetes (EFSD/MSD European Research Programme on Novel Therapies for Type 2 Diabetes,2013). V.J. was recipient of a post-doctoral research fellowship from EFSD/ Lilly. E.C., V.S., and C.M. received a predoctoral fellowship from Ministerio de Educación, Cultura y Deporte, and J.R. from Ministerio de Economía y Competitividad, Spain. The authors thank Marta Moya and Maria Molas for technical assistance.S

Whole body correction of mucopolysaccharidosis IIIA by intracerebrospinal fluid gene therapy

For most lysosomal storage diseases (LSDs) affecting the CNS, there is currently no cure. The BBB, which limits the bioavailability of drugs administered systemically, and the short half-life of lysosomal enzymes, hamper the development of effective therapies. Mucopolysaccharidosis type IIIA (MPS IIIA) is an autosomic recessive LSD caused by a deficiency in sulfamidase, a sulfatase involved in the stepwise degradation of glycosaminoglycan (GAG) heparan sulfate. Here, we demonstrate that intracerebrospinal fluid (intra-CSF) administration of serotype 9 adenoassociated viral vectors (AAV9s) encoding sulfamidase corrects both CNS and somatic pathology in MPS IIIA mice. Following vector administration, enzymatic activity increased throughout the brain and in serum, leading to whole body correction of GAG accumulation and lysosomal pathology, normalization of behavioral deficits, and prolonged survival. To test this strategy in a larger animal, we treated beagle dogs using intracisternal or intracerebroventricular delivery. Administration of sulfamidase-encoding AAV9 resulted in transgenic expression throughout the CNS and liver and increased sulfamidase activity in CSF. High-titer serum antibodies against AAV9 only partially blocked CSF-mediated gene transfer to the brains of dogs. Consistently, anti-AAV antibody titers were lower in CSF than in serum collected from healthy and MPS IIIA-affected children. These results support the clinical translation of this approach for the treatment of MPS IIIA and other LSDs with CNS involvement

Occurrence and ecological risk assessment of organic UV filters in coastal waters of the Iberian Peninsula

This study aimed to assess the presence of 21 UVFs and metabolites in coastal regions of the Iberian Peninsula, to evaluate their environmental risk, and identify possible influential factors affecting their measured concentrations. Sampling was carried out in spring and summer to assess possible seasonal variations. UVFs were detected in 43 of the 46 sampling sites. Only 5 were found above LOD: BP4, OC, BP3 and metabolites BP1 and BP8. Samples collected in Mar Menor had the greatest variety of compounds per sample and the highest cumulative concentrations. The risk was characterized using Risk Quotients (RQ). BP1 showed a Low environmental Risk in 2 sites while for OC the RQ indicated a Moderate Risk in 22 points. The variables that contribute most to the variation are population density, sampling season, whether it was an open bay or not, and level of urbanization. The presence of WWTPs had a lower influence.We thank the Rey Juan Carlos University Internal Program for the Promotion and Development of Research and Innovation – Bridge Grants 2020; the Spanish Ministry of Education and Professional Development, and the “Salvador Madariaga” Program in Support of Research Stays for Professor and Senior Researchers in Foreign Research Centres. A. Rico acknowledges the funding provided by the Talented Researcher Support Programme – PlanGenT(CIDEGENT/2020/043) of the Generalitat Valenciana. G. Quintana acknowledges the Spanish Ministry of Science and Innovation (Project CEX2018-000794-S) for his fellowship.Peer reviewe

Progressive neurologic and somatic disease in a novel mouse model of human mucopolysaccharidosis type IIIC

Mucopolysaccharidosis type IIIC (MPSIIIC) is a severe lysosomal storage disease caused by deficiency in activity of the transmembrane enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT) that catalyses the N-acetylation of α-glucosamine residues of heparan sulfate. Enzyme deficiency causes abnormal substrate accumulation in lysosomes, leading to progressive and severe neurodegeneration, somatic pathology and early death. There is no cure for MPSIIIC, and development of new therapies is challenging because of the unfeasibility of cross-correction. In this study, we generated a new mouse model of MPSIIIC by targeted disruption of the Hgsnat gene. Successful targeting left LacZ expression under control of the Hgsnat promoter, allowing investigation into sites of endogenous expression, which was particularly prominent in the CNS, but was also detectable in peripheral organs. Signs of CNS storage pathology, including glycosaminoglycan accumulation, lysosomal distension, lysosomal dysfunction and neuroinflammation were detected in 2-month-old animals and progressed with age. Glycosaminoglycan accumulation and ultrastructural changes were also observed in most somatic organs, but lysosomal pathology seemed most severe in liver. Furthermore, HGSNAT-deficient mice had altered locomotor and exploratory activity and shortened lifespan. Hence, this animal model recapitulates human MPSIIIC and provides a useful tool for the study of disease physiopathology and the development of new therapeutic approaches. Summary: A new animal model of the severe neurodegenerative lysosomal disorder mucopolysaccharidosis IIIC recapitulates the human disease, with progressive CNS and somatic lysosomal pathology, and shortened lifespan

Gene therapy for the treatment of neurologic and somatic mucopolysaccharidosis type II (hunter syndrome)

La Mucopolisacaridosis tipus II (MPSII), o síndrome de Hunter, és una malaltia d’acumulació lisosòmica d’herència recessiva lligada al cromosoma X i està causada per la deficiència de l’Iduronat-2-sulfatasa (IDS), enzim que actua en la via de degradació dels glicosaminoglicans (GAGs) heparan sulfat (HS) i dermatan sulfat (DS). Aquests GAGs no degradats s’acumulen als lisosomes de manera patològica, causant disfunció cel·lular. La forma més severa i també més prevalent de la MPSII es caracteritza per una neurodegeneració crònica i progressiva del sistema nerviós central (SNC) acompanyada de disfunció multisistèmica. Com a conseqüència, els pacients de MPSII solen morir durant la segona dècada de vida. Actualment, la única opció terapèutica disponible pels pacients amb Hunter és la teràpia de substitució enzimàtica (TSE), la qual consisteix en la infusió setmanal de l’enzim recombinant. No obstant, degut a la presència de la barrera hemato-encefàlica, la TSE no és efectiva en la correcció del deteriorament neurològic, a més de presentar altres inconvenients. Per tant, el desenvolupament d’una teràpia eficient pel tractament de la patologia neurodegenerativa característica de la MPSII és una necessitat mèdica no coberta. La teràpia gènica in vivo basada en l’administració de vectors virals derivats dels virus adeno-associat (AAV) representa una alternativa atractiva pel tractament d’aquesta malaltia, ja que ofereix la possibilitat d’obtenir benefici terapèutic de per vida després d’una única administració del producte terapèutic. Així doncs, la present tesi doctoral s’ha centrat en el desenvolupament d’una estratègia de teràpia gènica per a la MPSII basada en l’administració de vectors directe al líquid cefaloraquidi (LCR) amb la finalitat de tractar simultàniament tant la patologia neurologia com la somàtica de la malaltia. Mitjançant un procediment poc invasiu, es van administrar vectors AAV de serotip 9 (AAV9) que contenien el gen murí Ids (AAV9-Ids) al LCR de ratolins MPSII de 2 mesos d’edat, els quals ja presentaven una patologia ben establerta tant a nivell del SNC com a nivell somàtic. Transcorreguts 4 i 8 mesos després de l’administració, es va avaluar l’eficàcia del tractament en contrarestar la patologia de la MPSII. A nivell del SNC, l’augment d’activitat enzimàtica IDS obtinguda mitjançant el tractament va donar lloc a la completa correcció de les lesions lisosomals característiques a la MPSII. El tractament també va donar lloc a la correcció de la disfunció lisosomal del SNC, a la normalització de l’expressió gènica del cervell i a la eradicació de la neuroinflamació característica de la malaltia. A més, mitjançant l’administració al LCR, vectors AAV9-Ids també van transduir el fetge, convertit aquest òrgan en una font de la proteïna terapèutica a nivell perifèric. En conseqüència, l’enzim IDS produït al fetge de ratolins MPSII tractats va donar lloc a la correcció de la patologia somàtica. A més, la reversió de la patologia observada en aquells teixits somàtics no transduits pel vector AAV9-Ids va evidenciar el mecanisme de correcció creuada aconseguit mitjançant l’enzim IDS circulant. A banda d’aquests efectes, el tractament també va comportar una normalització de les alteracions de comportament característiques de la malaltia, així com també un augment significatiu de la supervivència dels ratolins MPSII. L’eficàcia obtinguda mitjançant l’administració de vectors AAV9 que contenien la seqüència codificant humana IDS també es va avaluar en ratolins MPSII. Després de 1,5 mesos de tractament, es va observar un increment en l’activitat IDS al cervell, fetge i sèrum, fet que va donar lloc a la correcció del contingut de GAGs tant a nivell del SNC com a nivell somàtic. Conjuntament, els resultats obtinguts en aquest treball recolzen la translació clínica de l’aproximació de teràpia gènica basada en l’administració al LCR de vectors AAV9-IDS pel tractament de pacients de Hunter amb afectació neurològica.Mucopolysaccharidosis type II (MPSII), or Hunter syndrome, is an X-linked recessive lysosomal storage disease (LSD) caused by the deficiency in Iduronate-2-sulfatase (IDS), an enzyme involved in the stepwise degradation of the glycosaminoglycans (GAGs) heparan sulfate (HS) and dermatan sulfate (DS). The pathological accumulation of undegraded HS and DS in the lysosomes leads to cell dysfunction, causing severe neurologic and somatic disease. The most severe and most prevalent form of Hunter syndrome is characterized by chronic and progressive neurodegeneration of the central nervous system (CNS) and multisystem dysfunction; patients usually die during the second decade of life. To date, weekly intravenous enzyme replacement therapy (ERT) constitutes the only approved therapeutic option for MPSII. However, the inability of recombinant IDS to efficiently cross the blood-brain barrier (BBB) limits the efficacy of ERT in treating neurological symptoms. The therapy has several other drawbacks. Thus, an efficient therapy for the treatment of the neurodegeneration of MPSII disease represents a highly unmet medical need. In vivo gene therapy with adeno-associated vectors offers the possibility of lifelong therapeutic benefit following a single administration. Therefore, the present work was focused on the development of a new gene therapy approach for MPSII based on the delivery of vectors to the cerebrospinal fluid (CSF) and aimed at counteracting simultaneously the neurological and somatic pathology characteristic of the disease. Adeno-associated virus serotype 9 vectors (AAV9) containing the murine Ids gene were administered through a minimal invasive procedure to the CSF of 2-month-old MPSII mice, which already presented established pathology. The efficacy of AAV9-Ids vectors to counteract MPSII pathology after a single intra-CSF injection was evaluated 4 and 8 months after treatment. AAV9-mediated Ids gene transfer led to a significant increase in IDS activity throughout the encephalon, which resulted in full reversion of lysosomal storage lesions. In addition, correction of lysosomal dysfunction in the CNS, normalization of brain transcriptomic signature and disappearance of neuroinflammation were achieved after gene transfer. Moreover, after AAV9-Ids delivery to the CSF, vectors also transduced the liver, providing a peripheral source of the therapeutic protein that corrected storage pathology in visceral organs of treated MPSII mice. The reversion of the pathology in non-transduced somatic organs provided evidence of cross-correction by circulating enzyme. Importantly, AAV9-Ids treatment also resulted in normalization of behavioural deficits and considerably prolonged the survival of treated MPSII mice. The efficacy of the intra-CSF administration of AAV9 vectors containing the human IDS coding sequence was also evaluated in MPSII mice. One and a half months after gene transfer, a significant increase in IDS activity was documented throughout the encephalon, an in the liver and serum of treated MPSII mice. Consequently, pathological GAG content was reduced, or even normalized, in the CNS and in most somatic tissues of MPSII mice that received the vectors. Altogether, the results obtained in the present work provide a strong proof of concept that supports the clinical translation of the intra-CSF AAV9-IDS gene therapy for the treatment of Hunter patients with cognitive impairment

Gene therapy for the treatment of neurologic and somatic mucopolysaccharidosis type II (hunter syndrome)

La Mucopolisacaridosis tipus II (MPSII), o síndrome de Hunter, és una malaltia d'acumulació lisosòmica d'herència recessiva lligada al cromosoma X i està causada per la deficiència de l'Iduronat-2-sulfatasa (IDS), enzim que actua en la via de degradació dels glicosaminoglicans (GAGs) heparan sulfat (HS) i dermatan sulfat (DS). Aquests GAGs no degradats s'acumulen als lisosomes de manera patològica, causant disfunció cel·lular. La forma més severa i també més prevalent de la MPSII es caracteritza per una neurodegeneració crònica i progressiva del sistema nerviós central (SNC) acompanyada de disfunció multisistèmica. Com a conseqüència, els pacients de MPSII solen morir durant la segona dècada de vida. Actualment, la única opció terapèutica disponible pels pacients amb Hunter és la teràpia de substitució enzimàtica (TSE), la qual consisteix en la infusió setmanal de l'enzim recombinant. No obstant, degut a la presència de la barrera hemato-encefàlica, la TSE no és efectiva en la correcció del deteriorament neurològic, a més de presentar altres inconvenients. Per tant, el desenvolupament d'una teràpia eficient pel tractament de la patologia neurodegenerativa característica de la MPSII és una necessitat mèdica no coberta. La teràpia gènica in vivo basada en l'administració de vectors virals derivats dels virus adeno-associat (16V) representa una alternativa atractiva pel tractament d'aquesta malaltia, ja que ofereix la possibilitat d'obtenir benefici terapèutic de per vida després d'una única administració del producte terapèutic. Així doncs, la present tesi doctoral s'ha centrat en el desenvolupament d'una estratègia de teràpia gènica per a la MPSII basada en l'administració de vectors directe al líquid cefaloraquidi (LCR) amb la finalitat de tractar simultàniament tant la patologia neurologia com la somàtica de la malaltia. Mitjançant un procediment poc invasiu, es van administrar vectors 16V de serotip 9 (16V9) que contenien el gen murí Ids (16V9-Ids) al LCR de ratolins MPSII de 2 mesos d'edat, els quals ja presentaven una patologia ben establerta tant a nivell del SNC com a nivell somàtic. Transcorreguts 4 i 8 mesos després de l'administració, es va avaluar l'eficàcia del tractament en contrarestar la patologia de la MPSII. A nivell del SNC, l'augment d'activitat enzimàtica IDS obtinguda mitjançant el tractament va donar lloc a la completa correcció de les lesions lisosomals característiques a la MPSII. El tractament també va donar lloc a la correcció de la disfunció lisosomal del SNC, a la normalització de l'expressió gènica del cervell i a la eradicació de la neuroinflamació característica de la malaltia. A més, mitjançant l'administració al LCR, vectors 16V9-Ids també van transduir el fetge, convertit aquest òrgan en una font de la proteïna terapèutica a nivell perifèric. En conseqüència, l'enzim IDS produït al fetge de ratolins MPSII tractats va donar lloc a la correcció de la patologia somàtica. A més, la reversió de la patologia observada en aquells teixits somàtics no transduits pel vector 16V9-Ids va evidenciar el mecanisme de correcció creuada aconseguit mitjançant l'enzim IDS circulant. A banda d'aquests efectes, el tractament també va comportar una normalització de les alteracions de comportament característiques de la malaltia, així com també un augment significatiu de la supervivència dels ratolins MPSII. L'eficàcia obtinguda mitjançant l'administració de vectors 16V9 que contenien la seqüència codificant humana IDS també es va avaluar en ratolins MPSII. Després de 1,5 mesos de tractament, es va observar un increment en l'activitat IDS al cervell, fetge i sèrum, fet que va donar lloc a la correcció del contingut de GAGs tant a nivell del SNC com a nivell somàtic. Conjuntament, els resultats obtinguts en aquest treball recolzen la translació clínica de l'aproximació de teràpia gènica basada en l'administració al LCR de vectors 16V9-IDS pel tractament de pacients de Hunter amb afectació neurològica.Mucopolysaccharidosis type II (MPSII), or Hunter syndrome, is an X-linked recessive lysosomal storage disease (LSD) caused by the deficiency in Iduronate-2-sulfatase (IDS), an enzyme involved in the stepwise degradation of the glycosaminoglycans (GAGs) heparan sulfate (HS) and dermatan sulfate (DS). The pathological accumulation of undegraded HS and DS in the lysosomes leads to cell dysfunction, causing severe neurologic and somatic disease. The most severe and most prevalent form of Hunter syndrome is characterized by chronic and progressive neurodegeneration of the central nervous system (CNS) and multisystem dysfunction; patients usually die during the second decade of life. To date, weekly intravenous enzyme replacement therapy (ERT) constitutes the only approved therapeutic option for MPSII. However, the inability of recombinant IDS to efficiently cross the blood-brain barrier (BBB) limits the efficacy of ERT in treating neurological symptoms. The therapy has several other drawbacks. Thus, an efficient therapy for the treatment of the neurodegeneration of MPSII disease represents a highly unmet medical need. In vivo gene therapy with adeno-associated vectors offers the possibility of lifelong therapeutic benefit following a single administration. Therefore, the present work was focused on the development of a new gene therapy approach for MPSII based on the delivery of vectors to the cerebrospinal fluid (CSF) and aimed at counteracting simultaneously the neurological and somatic pathology characteristic of the disease. Adeno-associated virus serotype 9 vectors (AAV9) containing the murine Ids gene were administered through a minimal invasive procedure to the CSF of 2-month-old MPSII mice, which already presented established pathology. The efficacy of AAV9-Ids vectors to counteract MPSII pathology after a single intra-CSF injection was evaluated 4 and 8 months after treatment. AAV9-mediated Ids gene transfer led to a significant increase in IDS activity throughout the encephalon, which resulted in full reversion of lysosomal storage lesions. In addition, correction of lysosomal dysfunction in the CNS, normalization of brain transcriptomic signature and disappearance of neuroinflammation were achieved after gene transfer. Moreover, after AAV9-Ids delivery to the CSF, vectors also transduced the liver, providing a peripheral source of the therapeutic protein that corrected storage pathology in visceral organs of treated MPSII mice. The reversion of the pathology in non-transduced somatic organs provided evidence of cross-correction by circulating enzyme. Importantly, AAV9-Ids treatment also resulted in normalization of behavioural deficits and considerably prolonged the survival of treated MPSII mice. The efficacy of the intra-CSF administration of AAV9 vectors containing the human IDS coding sequence was also evaluated in MPSII mice. One and a half months after gene transfer, a significant increase in IDS activity was documented throughout the encephalon, an in the liver and serum of treated MPSII mice. Consequently, pathological GAG content was reduced, or even normalized, in the CNS and in most somatic tissues of MPSII mice that received the vectors. Altogether, the results obtained in the present work provide a strong proof of concept that supports the clinical translation of the intra-CSF AAV9-IDS gene therapy for the treatment of Hunter patients with cognitive impairment

Insulin-like growth factor I (IGF-I)-induced chronic gliosis and retinal stress lead to neurodegeneration in a mouse model of retinopathy

Insulin-like growth factor I (IGF-I) exerts multiple effects on different retinal cell types in both physiological and pathological conditions. Despite the growth factor's extensively described neuroprotective actions, transgenic mice with increased intraocular levels of IGF-I showed progressive impairment of electroretinographic amplitudes up to complete loss of response, with loss of photoreceptors and bipolar, ganglion, and amacrine neurons. Neurodegeneration was preceded by the overexpression of genes related to retinal stress, acute-phase response, and gliosis, suggesting that IGF-I altered normal retinal homeostasis. Indeed, gliosis and microgliosis were present from an early age in transgenic mice, before other alterations occurred, and were accompanied by signs of oxidative stress and impaired glutamate recycling. Older mice also showed overproduction of pro-inflammatory cytokines. Our results suggest that, when chronically increased, intraocular IGF-I is responsible for the induction of deleterious cellular processes that can lead to neurodegeneration, and they highlight the importance that this growth factor may have in the pathogenesis of conditions such as ischemic or diabetic retinopathy