Laser injury promotes migration and integration of retinal progenitor cells into host retina

PurposeThe migration and integration of grafted cells into diseased host tissue remains a critical challenge, particularly in the field of retinal progenitor cell (RPC) transplantation. It seems that natural physical barriers at the outer retina can impede the migration of grafted RPCs into the host retina. The purpose of this study was to investigate the integration and differentiation of murine RPCs transplanted into the subretinal space of mice with laser-induced damage to the outer retina.MethodsRPCs were harvested from the neural retinas of postnatal day 1 enhanced green fluorescent protein (GFP) mice. Retinal photocoagulation was performed using a diode laser. Two µl containing ~6×105 expanded RPCs in suspension were injected into the subretinal space of the recipient animals following laser treatment. Cell morphometry was performed to assess the integration of donor cells. Immunohistochemistry and western blot were performed on recipient retinas.ResultsThree weeks after transplantation, 1,158±320 cells per eye had migrated into the recipient outer nuclear layer (ONL). Most of these cells resided in the ONL around the retinal laser lesion. A subpopulation of these cells developed morphological features reminiscent of mature photoreceptors, expressed photoreceptor specific proteins including synaptic protein, and appeared to form synaptic connections with bipolar neurons. Retinal photocoagulation resulted in a significantly increased expression of matrix metalloproteinase-2 (MMP-2), MMP-9, and cluster differentiation 44 (CD44s), and a decreased expression of neurocan.ConclusionsTransplanted RPCs migrate and integrate into the laser-injured ONL where they differentiate into photoreceptors with morphological features reminiscent of mature photoreceptors, express synaptic protein, and appear to form synaptic connections with retinal bipolar neurons. Following retinal photocoagulation, the enhanced level of integration of grafted RPCs is partially associated with increased expression of MMP-2 and, to a lesser extent, MMP-9, together with decreased levels of inhibitory molecules

Müller cell activation, proliferation and migration following laser injury.

PurposeMüller cells are well known for their critical role in normal retinal structure and function, but their reaction to retinal injury and subsequent role in retinal remodeling is less well characterized. In this study we used a mouse model of retinal laser photocoagulation to examine injury-induced Müller glial reaction, and determine how this reaction was related to injury-induced retinal regeneration and cellular repopulation.MethodsExperiments were performed on 3-4-week-old C57BL/6 mice. Retinal laser photocoagulation was used to induce small, circumscribed injuries; these were principally confined to the outer nuclear layer, and surrounded by apparently healthy retinal tissue. Western blotting and immunohistochemical analyses were used to determine the level and location of protein expression. Live cell imaging of green fluorescent protein (GFP)-infected Müller cells (AAV-GFAP-GFP) were used to identify the rate and location of retinal Müller cell nuclear migration.ResultsUpon injury, Müller cells directly at the burn site become reactive, as evidenced by increased expression of the intermediate filament proteins glial fibrillary acidic protein (GFAP) and nestin. These reactive cells re-enter the cell cycle as shown by expression of the markers Cyclin D1 and D3, and their nuclei begin to migrate toward the injury site at a rate of approximately 12 microm/hr. However, unlike other reports, evidence for Müller cell transdifferentiation was not identified in this model.ConclusionsRetinal laser photocoagulation is capable of stimulating a significant glial reaction, marked by activation of cell cycle progression and retinal reorganization, but is not capable of stimulating cellular transdifferentiation or neurogenesis

Transplantation of Adult Mouse iPS Cell-Derived Photoreceptor Precursors Restores Retinal Structure and Function in Degenerative Mice

This study was designed to determine whether adult mouse induced pluripotent stem cells (iPSCs), could be used to produce retinal precursors and subsequently photoreceptor cells for retinal transplantation to restore retinal function in degenerative hosts. iPSCs were generated using adult dsRed mouse dermal fibroblasts via retroviral induction of the transcription factors Oct4, Sox2, KLF4 and c-Myc. As with normal mouse ES cells, adult dsRed iPSCs expressed the pluripotency genes SSEA1, Oct4, Sox2, KLF4, c-Myc and Nanog. Following transplantation into the eye of immune-compromised retinal degenerative mice these cells proceeded to form teratomas containing tissue comprising all three germ layers. At 33 days post-differentiation a large proportion of the cells expressed the retinal progenitor cell marker Pax6 and went on to express the photoreceptor markers, CRX, recoverin, and rhodopsin. When tested using calcium imaging these cells were shown to exhibit characteristics of normal retinal physiology, responding to delivery of neurotransmitters. Following subretinal transplantation into degenerative hosts differentiated iPSCs took up residence in the retinal outer nuclear layer and gave rise to increased electro retinal function as determined by ERG and functional anatomy. As such, adult fibroblast-derived iPSCs provide a viable source for the production of retinal precursors to be used for transplantation and treatment of retinal degenerative disease

Pseudophakic monovision is an important surgical approach to being spectacle-free

There are few studies on pseudophakic monovision even though it is widely applied. We reviewed the published literature on pseudophakic monovision. Surgeons select patients who not only have a strong desire to be free of glasses after surgery, but also fully understand monovision design and its drawbacks. However, other criteria adopted for pseudophakic monovision are very different. Both traditional monovision and cross monovision are used in pseudophakic monovision, and the target binocular anisometropia ranges from -1.0 D to -2.75 D. Postoperative results were acceptable in every study and most patients were satisfied, with vision being improved and presbyopia corrected. Complications were decreased stereopsis, contrast sensitivity, and visual fields, similar to other types of monovision. The term "pseudophakic monovision" should include more than just monocular intraocular lens implantation in two eyes, and further studies are required

Laser injury promotes migration and integration of retinal progenitor cells into host retina

PurposeThe migration and integration of grafted cells into diseased host tissue remains a critical challenge, particularly in the field of retinal progenitor cell (RPC) transplantation. It seems that natural physical barriers at the outer retina can impede the migration of grafted RPCs into the host retina. The purpose of this study was to investigate the integration and differentiation of murine RPCs transplanted into the subretinal space of mice with laser-induced damage to the outer retina.MethodsRPCs were harvested from the neural retinas of postnatal day 1 enhanced green fluorescent protein (GFP) mice. Retinal photocoagulation was performed using a diode laser. Two µl containing ~6×105 expanded RPCs in suspension were injected into the subretinal space of the recipient animals following laser treatment. Cell morphometry was performed to assess the integration of donor cells. Immunohistochemistry and western blot were performed on recipient retinas.ResultsThree weeks after transplantation, 1,158±320 cells per eye had migrated into the recipient outer nuclear layer (ONL). Most of these cells resided in the ONL around the retinal laser lesion. A subpopulation of these cells developed morphological features reminiscent of mature photoreceptors, expressed photoreceptor specific proteins including synaptic protein, and appeared to form synaptic connections with bipolar neurons. Retinal photocoagulation resulted in a significantly increased expression of matrix metalloproteinase-2 (MMP-2), MMP-9, and cluster differentiation 44 (CD44s), and a decreased expression of neurocan.ConclusionsTransplanted RPCs migrate and integrate into the laser-injured ONL where they differentiate into photoreceptors with morphological features reminiscent of mature photoreceptors, express synaptic protein, and appear to form synaptic connections with retinal bipolar neurons. Following retinal photocoagulation, the enhanced level of integration of grafted RPCs is partially associated with increased expression of MMP-2 and, to a lesser extent, MMP-9, together with decreased levels of inhibitory molecules

A new classification for epidemiological study of mechanical eye injuries

【Abstract】Objective: Considering the difficulty in classifying some cases with eye trauma by Birmingham Eye Trauma Terminology (BETT) in our epidemiological study, we introduce a new classification for epidemiological study of mechanical eye injuries based on BETT. Methods: A retrospective investigation was carried out in 31 hospitals from January 2005 to December 2010. All medical records of inpatients with eye injuries were reviewed. A total of 10 718 patients (11 227 eyes) were diagnosed as mechanical eye injuries. All mechanical eye injuries were tried to be classified using BETT. While some eye injuries were difficult to categorize. We recorded the injury type and case number. A new classification based on BETT was also used for the same project. Results: Of 10 718 patients (11 227 eyes) with mechanical eye injuries, the following cases cannot be classified by BETT: 1 488 patients (1 559 eyes) with merely orbital or ocular adnexa injury, 1 961 (2 054) globe injuries associated with orbital or ocular adnexa injury, 271 (284) ocular surface foreign body (OSFB) or ocular wall foreign body (OWFB), 77 (89) contusion, 9 (11) lamellar laceration associated with OSFB or OWFB, 29 (30) rupture associated with OSFB, OWFB or intraocular foreign body and 60 (62) laceration associated with OSFB or OWFB. While according to our new classification, all eye injuries can be categorized without any difficulty. Conclusion: Difficulty in classifying some eye injuries in epidemiological study by BETT brings some trouble to our study, which can be solved by our new eye injury classification to some extent. It is hoped that other ophthalmologists present better ones to make the classification more perfect

Intravitreal injections of GDNF-loaded biodegradable microspheres are neuroprotective in a rat model of glaucoma.

To evaluate the efficacy of intravitreal injection of GDNF-loaded biodegradable microspheres in promoting the survival of retinal ganglion cells (RGCs) and their axons in a rat model of chronically elevated intraocular pressure (IOP).Chronic elevation of IOP was induced in Brown Norway rats through injection of hypertonic saline (1.9 M) into the episcleral veins. After injection, IOP was measured twice a week in rats using topical anesthesia. Poly DL-lactide-co-glycolide (PLGA) microspheres were fabricated using a modified version of the spontaneous emulsification technique. Two and ten percent of volume solutions of microspheres loaded with glial cell line-derived neurotrophic factor (GDNF) were injected into the vitreous cavity of rats with elevated IOP, with injections of blank microspheres and PBS serving as controls. Histological analysis was used to quantify surviving RGCs and axons and provide comparison among different groups. In addition, the thickness of the retinal inner plexiform layer (IPL) and the level of glial fibrillary acidic protein (GFAP) expression within the retina and optic nerve were quantitatively compared.IOP was significantly increased in eyes with episcleral vein injection over untreated eyes (p<0.001) but did not show a significant difference among groups that received intravitreal injections of GDNF microspheres, blank microspheres, or PBS (p=0.1852). The duration of IOP elevation in this experiment was eight weeks. Expression of GDNF and its receptors localizes to the adult rat RGCs. Ten percent of the GDNF microsphere treatment significantly increased RGC survival and axon survival (p<0.001), reduced the loss of retinal IPL thickness (p<0.001), and decreased glial cell activation in the retina and optic nerve (p<0.001) compared with blank microspheres and PBS. In addition, GDNF microsphere treatment moderately reduced cupping of the optic nerve head.Delivery of GDNF via biodegradable microspheres significantly increased the survival of RGCs and their axons, preserved IPL thickness, and decreased retina and optic nerve glial cell activation in an experimental glaucoma model. This study suggests that GDNF delivered by PLGA microspheres may be useful as a neuroprotective tool in the treatment of glaucomatous optic neuropathy

Intravitreal injections of GDNF-loaded biodegradable microspheres are neuroprotective in a rat model of glaucoma.

To evaluate the efficacy of intravitreal injection of GDNF-loaded biodegradable microspheres in promoting the survival of retinal ganglion cells (RGCs) and their axons in a rat model of chronically elevated intraocular pressure (IOP).Chronic elevation of IOP was induced in Brown Norway rats through injection of hypertonic saline (1.9 M) into the episcleral veins. After injection, IOP was measured twice a week in rats using topical anesthesia. Poly DL-lactide-co-glycolide (PLGA) microspheres were fabricated using a modified version of the spontaneous emulsification technique. Two and ten percent of volume solutions of microspheres loaded with glial cell line-derived neurotrophic factor (GDNF) were injected into the vitreous cavity of rats with elevated IOP, with injections of blank microspheres and PBS serving as controls. Histological analysis was used to quantify surviving RGCs and axons and provide comparison among different groups. In addition, the thickness of the retinal inner plexiform layer (IPL) and the level of glial fibrillary acidic protein (GFAP) expression within the retina and optic nerve were quantitatively compared.IOP was significantly increased in eyes with episcleral vein injection over untreated eyes (p<0.001) but did not show a significant difference among groups that received intravitreal injections of GDNF microspheres, blank microspheres, or PBS (p=0.1852). The duration of IOP elevation in this experiment was eight weeks. Expression of GDNF and its receptors localizes to the adult rat RGCs. Ten percent of the GDNF microsphere treatment significantly increased RGC survival and axon survival (p<0.001), reduced the loss of retinal IPL thickness (p<0.001), and decreased glial cell activation in the retina and optic nerve (p<0.001) compared with blank microspheres and PBS. In addition, GDNF microsphere treatment moderately reduced cupping of the optic nerve head.Delivery of GDNF via biodegradable microspheres significantly increased the survival of RGCs and their axons, preserved IPL thickness, and decreased retina and optic nerve glial cell activation in an experimental glaucoma model. This study suggests that GDNF delivered by PLGA microspheres may be useful as a neuroprotective tool in the treatment of glaucomatous optic neuropathy

The complete chloroplast genome of Cinnamomum camphora and its comparison with related Lauraceae species

Cinnamomum camphora, a member of the Lauraceae family, is a valuable aromatic and timber tree that is indigenous to the south of China and Japan. All parts of Cinnamomum camphora have secretory cells containing different volatile chemical compounds that are utilized as herbal medicines and essential oils. Here, we reported the complete sequencing of the chloroplast genome of Cinnamomum camphora using illumina technology. The chloroplast genome of Cinnamomum camphora is 152,570 bp in length and characterized by a relatively conserved quadripartite structure containing a large single copy region of 93,705 bp, a small single copy region of 19,093 bp and two inverted repeat (IR) regions of 19,886 bp. Overall, the genome contained 123 coding regions, of which 15 were repeated in the IR regions. An analysis of chloroplast sequence divergence revealed that the small single copy region was highly variable among the different genera in the Lauraceae family. A total of 40 repeat structures and 83 simple sequence repeats were detected in both the coding and non-coding regions. A phylogenetic analysis indicated that Calycanthus is most closely related to Lauraceae, both being members of Laurales, which forms a sister group to Magnoliids. The complete sequence of the chloroplast of Cinnamomum camphora will aid in in-depth taxonomical studies of the Lauraceae family in the future. The genetic sequence information will also have valuable applications for chloroplast genetic engineering