Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization （EVC） model by multiple in vivo and...Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization （EVC） model by multiple in vivo and in vitro evidences.Methods Wistar rat was used in this study.The elevated intraocular pressure （IOP） was induced by cauterization of three episcleral veins.lOP was monitored with Tono-Pen XL tonometer.Time-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence tomography.The function of retina was evaluated by electroretinogram （ERG）.Survival of retinal ganglion cells （RGCs） was quantified by retrograde labeling.Histology study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear antigen.Retina and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha （TNF-α） and alpha-2 macroglobulin （α2m） were measured with Western blotting.Results EVC is a relatively facile intervention,with low failure rates （＜5％）.After surgical intervention,chronic mild lOP elevation （about 1.6-fold over normal,P ＜0.05） was induced for at least 6 weeks without requiring a second intervention.High lOP causes chronic and progressive loss of RGCs （averaging about 4％ per week）,progressive thinning of neuronal retinal layers （3-5 μm per week）,and reduction of a-and b-wave in ERG.EVC method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α2m.Conclusion EVC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.展开更多
e-related macular degeneration （AMD） causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests fr...e-related macular degeneration （AMD） causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer＇s-linked amyloid beta （Aβ） group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer＇s disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.展开更多
Cell therapy offers great promises in replacing the neurons lost due to neurodegenerative diseases or injuries.However,a key challenge is the cellular source for transplantation which is often limited by donor availab...Cell therapy offers great promises in replacing the neurons lost due to neurodegenerative diseases or injuries.However,a key challenge is the cellular source for transplantation which is often limited by donor availability.Direct reprogramming provides an exciting avenue to generate specialized neuron subtypes in vitro,which have the potential to be used for autologous transplantation,as well as generation of patient-specific disease models in the lab for drug discovery and testing gene therapy.Here we present a detailed review on transcription factors that promote direct reprogramming of specific neuronal subtypes with particular focus on glutamatergic,GABAergic,dopaminergic,sensory and retinal neurons.We will discuss the developmental role of master transcriptional regulators and specification factors for neuronal subtypes,and summarize their use in promoting direct reprogramming into different neuronal subtypes.Furthermore,we will discuss up-and-coming technologies that advance the cell reprogramming field,including the use of computational prediction of reprogramming factors,opportunity of cellular reprogramming using small chemicals and microRNA,as well as the exciting potential for applying direct reprogramming in vivo as a novel approach to promote neuro-regeneration within the body.Finally,we will highlight the clinical potential of direct reprogramming and discuss the hurdles that need to be overcome for clinical translation.展开更多
Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plast...Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plastic plates and coverslips coated with poly-lysine or ethylene imine polymer for primary culture.The cultured cells were divided into following groups:1.Culture medium changed every 2 tp 3 days vs changed only once;2.Cytosine arabinoside(Ara-C)added to the culture medium vs not added.The cells were observed and pictured under inverted phase contrast microscope.The cells were identified through immunocytochemistry.Results:The immunofluorescence showed that most of the cultured cells were neurons,among them were a few retinal ganglion cells.In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c,the neurons intended to aggregate into clusters with relatively straight neurites.In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c,the neurons grew dispersively with bent neurites.Both of them survived for 2 to 3 weeks.The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks.In the group of which medium changed several times,the survival time of neurons was shorter than that in the medium changed only once.Conclusions:The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth.It is not favorable for the growth of the neurons by changing culture medium many times.Ara-c may possibly have side effect on the growth of retinal neurons.展开更多
基金This work was supported by grants from Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme （2010）, Key Project of Guangdong Province Natural Science Foundation （No. 10251008901000028）.
文摘Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization （EVC） model by multiple in vivo and in vitro evidences.Methods Wistar rat was used in this study.The elevated intraocular pressure （IOP） was induced by cauterization of three episcleral veins.lOP was monitored with Tono-Pen XL tonometer.Time-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence tomography.The function of retina was evaluated by electroretinogram （ERG）.Survival of retinal ganglion cells （RGCs） was quantified by retrograde labeling.Histology study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear antigen.Retina and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha （TNF-α） and alpha-2 macroglobulin （α2m） were measured with Western blotting.Results EVC is a relatively facile intervention,with low failure rates （＜5％）.After surgical intervention,chronic mild lOP elevation （about 1.6-fold over normal,P ＜0.05） was induced for at least 6 weeks without requiring a second intervention.High lOP causes chronic and progressive loss of RGCs （averaging about 4％ per week）,progressive thinning of neuronal retinal layers （3-5 μm per week）,and reduction of a-and b-wave in ERG.EVC method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α2m.Conclusion EVC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.
基金funded by the National Centre for the Replacement Refinement&Reduction of Animals in Research(NC3R:Grant#NC/L001152/1)the Macular Society,UK,National Eye Research Centrethe Gift of Sight Appeal
文摘e-related macular degeneration （AMD） causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer＇s-linked amyloid beta （Aβ） group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer＇s disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.
基金Supported by funding from the Ophthalmic Research Institute of Australia,the University of Melbourne De Brettville Trustthe Kel and Rosie Day Foundationthe Centre for Eye Research Australia
文摘Cell therapy offers great promises in replacing the neurons lost due to neurodegenerative diseases or injuries.However,a key challenge is the cellular source for transplantation which is often limited by donor availability.Direct reprogramming provides an exciting avenue to generate specialized neuron subtypes in vitro,which have the potential to be used for autologous transplantation,as well as generation of patient-specific disease models in the lab for drug discovery and testing gene therapy.Here we present a detailed review on transcription factors that promote direct reprogramming of specific neuronal subtypes with particular focus on glutamatergic,GABAergic,dopaminergic,sensory and retinal neurons.We will discuss the developmental role of master transcriptional regulators and specification factors for neuronal subtypes,and summarize their use in promoting direct reprogramming into different neuronal subtypes.Furthermore,we will discuss up-and-coming technologies that advance the cell reprogramming field,including the use of computational prediction of reprogramming factors,opportunity of cellular reprogramming using small chemicals and microRNA,as well as the exciting potential for applying direct reprogramming in vivo as a novel approach to promote neuro-regeneration within the body.Finally,we will highlight the clinical potential of direct reprogramming and discuss the hurdles that need to be overcome for clinical translation.
基金by National Natural Sciences Foundation of China (No.39770789)Natural Sciences Foundation of Guangdong Province (No.990092)
文摘Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plastic plates and coverslips coated with poly-lysine or ethylene imine polymer for primary culture.The cultured cells were divided into following groups:1.Culture medium changed every 2 tp 3 days vs changed only once;2.Cytosine arabinoside(Ara-C)added to the culture medium vs not added.The cells were observed and pictured under inverted phase contrast microscope.The cells were identified through immunocytochemistry.Results:The immunofluorescence showed that most of the cultured cells were neurons,among them were a few retinal ganglion cells.In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c,the neurons intended to aggregate into clusters with relatively straight neurites.In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c,the neurons grew dispersively with bent neurites.Both of them survived for 2 to 3 weeks.The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks.In the group of which medium changed several times,the survival time of neurons was shorter than that in the medium changed only once.Conclusions:The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth.It is not favorable for the growth of the neurons by changing culture medium many times.Ara-c may possibly have side effect on the growth of retinal neurons.
