RESUMO
Neuroprotection after injury or in neurodegenerative disease remains a major goal for basic and translational neuroscience. Retinal ganglion cells (RGCs), the projection neurons of the eye, degenerate in optic neuropathies after axon injury, and there are no clinical therapies to prevent their loss or restore their connectivity to targets in the brain. Here we demonstrate a profound neuroprotective effect of the exogenous expression of various Ca2+/calmodulin-dependent protein kinase II (CaMKII) isoforms in mice. A dramatic increase in RGC survival following the optic nerve trauma was elicited by the expression of constitutively active variants of multiple CaMKII isoforms in RGCs using adeno-associated viral (AAV) vectors across a 100-fold range of AAV dosing in vivo. Despite this neuroprotection, however, short-distance RGC axon sprouting was suppressed by CaMKII, and long-distance axon regeneration elicited by several pro-axon growth treatments was likewise inhibited even as CaMKII further enhanced RGC survival. Notably, in a dose-escalation study, AAV-expressed CaMKII was more potent for axon growth suppression than the promotion of survival. That diffuse overexpression of constitutively active CaMKII strongly promotes RGC survival after axon injury may be clinically valuable for neuroprotection per se. However, the associated strong suppression of the optic nerve axon regeneration demonstrates the need for understanding the intracellular domain- and target-specific CaMKII activities to the development of CaMKII signaling pathway-directed strategies for the treatment of optic neuropathies.
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Doenças Neurodegenerativas , Doenças do Nervo Óptico , Traumatismos do Nervo Óptico , Camundongos , Animais , Células Ganglionares da Retina/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Axônios/metabolismo , Doenças Neurodegenerativas/metabolismo , Regeneração Nervosa/fisiologia , Doenças do Nervo Óptico/metabolismo , Isoformas de Proteínas/metabolismo , Sobrevivência Celular/fisiologiaRESUMO
Esterification of anthocyanins with saturated fatty acids have been widely investigated, while that with unsaturated fatty acids is little understood. In this study, crude extract (purity â¼ 35 %) of cyanidin-3-O-glucoside (C3G) from black bean seed coat was utilized as reaction substrate, and enzymatically acylated with unsaturated fatty acid (oleic acid). Optimization of various reaction parameters finally resulted in the highest acylation rate of 54.3 %. HPLC-MS/MS and NMR analyses elucidated the structure of cyanidin-3-O-glucoside-oleic acid ester (C3G-OA) to be cyanidin-3-O-(6â³-octadecene)-glucoside. Introduction of oleic acid into C3G improved the lipophilicity, antioxidant ability, and antibacterial activity. Further, the color and substance stability analyses showed that the susceptibility of C3G and C3G-OA to different thermal, peroxidative, and illuminant treatments were highly pH dependent, which suggested individual application guidelines. Moreover, C3G-OA showed lower toxicity to normal cell (QSG-7701) and better inhibitory effect on the proliferation of HepG2 cells than C3G, which indicated its potential anti-tumor bioactivity.
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Antocianinas , Ácido Oleico , Antocianinas/química , Humanos , Ácido Oleico/química , Esterificação , Extratos Vegetais/química , Antioxidantes/química , Antioxidantes/farmacologia , Células Hep G2 , Phaseolus/química , Antibacterianos/química , Antibacterianos/farmacologia , Estrutura MolecularRESUMO
Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.
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Glaucoma , Doenças Neurodegenerativas , Doenças do Nervo Óptico , Humanos , Animais , Glaucoma/tratamento farmacológico , Glaucoma/patologia , Células Ganglionares da Retina/patologia , Doenças do Nervo Óptico/terapia , Doenças do Nervo Óptico/patologia , Progressão da Doença , Doenças Neurodegenerativas/patologia , Modelos Animais de DoençasRESUMO
Retinal ganglion cell (RGC) death in glaucoma and other optic neuropathies results in irreversible vision loss due to the mammalian central nervous system's limited regenerative capacity. RGC repopulation is a promising therapeutic approach to reverse vision loss from optic neuropathies if the newly introduced neurons can reestablish functional retinal and thalamic circuits. In theory, RGCs might be repopulated through the transplantation of stem cell-derived neurons or via the induction of endogenous transdifferentiation. The RGC Repopulation, Stem Cell Transplantation, and Optic Nerve Regeneration (RReSTORe) Consortium was established to address the challenges associated with the therapeutic repair of the visual pathway in optic neuropathy. In 2022, the RReSTORe Consortium initiated ongoing international collaborative discussions to advance the RGC repopulation field and has identified five critical areas of focus: (1) RGC development and differentiation, (2) Transplantation methods and models, (3) RGC survival, maturation, and host interactions, (4) Inner retinal wiring, and (5) Eye-to-brain connectivity. Here, we discuss the most pertinent questions and challenges that exist on the path to clinical translation and suggest experimental directions to propel this work going forward. Using these five subtopic discussion groups (SDGs) as a framework, we suggest multidisciplinary approaches to restore the diseased visual pathway by leveraging groundbreaking insights from developmental neuroscience, stem cell biology, molecular biology, optical imaging, animal models of optic neuropathy, immunology & immunotolerance, neuropathology & neuroprotection, materials science & biomedical engineering, and regenerative neuroscience. While significant hurdles remain, the RReSTORe Consortium's efforts provide a comprehensive roadmap for advancing the RGC repopulation field and hold potential for transformative progress in restoring vision in patients suffering from optic neuropathies.
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Doenças do Nervo Óptico , Células Ganglionares da Retina , Animais , Humanos , Retina , Encéfalo , Diferenciação Celular , MamíferosRESUMO
There is an unmet need for a safer and more effective approach for antimetabolite application to prevent bleb fibrosis after glaucoma filtering surgery. Here, we utilized our previously developed thermosensitive sustained-release agent, mitomycin C-loaded poly(trimethylene carbonate)15-F127-poly(trimethylene carbonate)15 (MMC-hydrogel), aiming to further evaluate the efficacy and safety of MMC-hydrogel in high intraocular pressure (IOP) primate eyes. Twelve primate eyes after high IOP induction were randomly divided into three groups, which respectively received phosphate-buffered saline (PBS)-hydrogel, MMC-hydrogel, and MMC treatment during trabeculectomy. IOP and bleb volume were measured using a Tonopen and anterior segment optical coherence tomography over 28 days. At the end of the experiment, all experimental primate eyes were enucleated. Histopathology and immunohistochemistry were performed to reveal myofibroblast cells and collagen deposition of filtering blebs. The MMC-hydrogel group had satisfactory IOP control (9.25 ± 4.80 mmHg) and maintained well-functioning blebs for a longer time. Fibrosis and scarring were significantly alleviated in this MMC-hydrogel group. There was no obvious toxicity to ocular surfaces or intraocular structures. Taken together, these data suggest that PTMC15-F127-PTMC15-loaded MMC-hydrogel plays a role in functional maintenance and scarring inhibition, showing high efficacy in reducing post-filtering surgery bleb fibrosis. This MMC-hydrogel may offer a new solution for filtering bleb management after glaucoma surgery.
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Purpose: Axon transport of organelles and neurotrophic factors is necessary for maintaining cellular function and survival of retinal ganglion cells (RGCs). However, it is not clear how trafficking of mitochondria, essential for RGC growth and maturation, changes during RGC development. The purpose of this study was to understand the dynamics and regulation of mitochondrial transport during RGC maturation using acutely purified RGCs as a model system. Methods: Primary RGCs were immunopanned from rats of either sex during three stages of development. MitoTracker dye and live-cell imaging were used to quantify mitochondrial motility. Analysis of single-cell RNA sequencing was used to identify Kinesin family member 5A (Kif5a) as a relevant motor candidate for mitochondrial transport. Kif5a expression was manipulated with either short hairpin RNA (shRNA) or exogenous expression adeno-associated virus viral vectors. Results: Anterograde and retrograde mitochondrial trafficking and motility decreased through RGC development. Similarly, the expression of Kif5a, a motor protein that transports mitochondria, also decreased during development. Kif5a knockdown decreased anterograde mitochondrial transport, while Kif5a expression increased general mitochondrial motility and anterograde mitochondrial transport. Conclusions: Our results suggested that Kif5a directly regulates mitochondrial axonal transport in developing RGCs. Future work exploring the role of Kif5a in vivo in RGCs is indicated.
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Mitocôndrias , Células Ganglionares da Retina , Animais , Ratos , Transporte Axonal , Cinesinas/genética , Modelos Biológicos , RNA Interferente Pequeno/genéticaRESUMO
Retinal ganglion cell (RGC) replacement therapy could restore vision in glaucoma and other optic neuropathies. We developed a rapid protocol for directly induced RGC (iRGC) differentiation from human stem cells, leveraging overexpression of NGN2. Neuronal morphology and neurite growth were observed within 1 week of induction; characteristic RGC-specific gene expression confirmed identity. Calcium imaging demonstrated γ-aminobutyric acid (GABA)-induced excitation characteristic of immature RGCs. Single-cell RNA sequencing showed more similarities between iRGCs and early-stage fetal human RGCs than retinal organoid-derived RGCs. Intravitreally transplanted iRGCs survived and migrated into host retinas independent of prior optic nerve trauma, but iRGCs protected host RGCs from neurodegeneration. These data demonstrate rapid iRGC generation in vitro into an immature cell with high similarity to human fetal RGCs and capacity for retinal integration after transplantation and neuroprotective function after optic nerve injury. The simplicity of this system may benefit translational studies on human RGCs.
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Glaucoma , Traumatismos do Nervo Óptico , Humanos , Células Ganglionares da Retina , Traumatismos do Nervo Óptico/metabolismo , Retina , Células-TroncoRESUMO
Transplantation of stem cell-derived retinal neurons is a promising regenerative therapy for optic neuropathy. However, significant anatomic differences compromise its efficacy in large animal models. The present study describes the procedure and outcomes of human-induced pluripotent stem cell (hiPSC)-derived retinal sheet transplantation in primate models using biodegradable materials. Stem cell-derived retinal organoids were seeded on polylactic-coglycolic acid (PLGA) scaffolds and directed toward a retinal ganglion cell (RGC) fate. The seeded tissues showed active proliferation, typical neuronal morphology, and electrical excitability. The cellular scaffolds were then epiretinally transplanted onto the inner surface of rhesus monkey retinas. With sufficient graft-host contact provided by the scaffold, the transplanted tissues survived for up to 1 year without tumorigenesis. Histological examinations indicated survival, further maturation, and migration. Moreover, green fluorescent protein-labeled axonal projections toward the host optic nerve were observed. Cryopreserved organoids were also able to survive and migrate after transplantation. Our results suggest the potential efficacy of RGC replacement therapy in the repair of optic neuropathy for the restoration of visual function. STATEMENT OF SIGNIFICANCE: In the present study, we generated a human retinal sheet by seeding hiPSC-retinal organoid-derived RGCs on a biodegradable PLGA scaffold. We transplanted this retinal sheet onto the inner surface of the rhesus monkey retina. With scaffold support, donor cells survive, migrate and project their axons into the host optic nerve. Furthermore, an effective cryopreservation strategy for retinal organoids was developed, and the thawed organoids were also observed to survive and show cell migration after transplantation.
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Células-Tronco Pluripotentes Induzidas , Animais , Axônios , Nervo Óptico , Retina , Células Ganglionares da RetinaRESUMO
BACKGROUND: BAM15 is a novel mitochondrial protonophore uncoupler capable of protecting mammals from acute renal ischemic-reperfusion injury and cold-induced microtubule damage. The purpose of our study was to investigate the effect of BAM15 on apoptosis during 5-day transportation of human-induced pluripotent stem (hiPS)-differentiated retinal tissue. METHODS: Retinal tissues of 30 days and 60 days were transported with or without BAM15 for 5 days in the laboratory or by real express. Immunofluorescence staining of apoptosis marker cleaved caspase3, proliferation marker Ki67, and neural axon marker NEFL was performed. And expression of apoptotic-related factors p53, NFkappaB, and TNF-a was detected by real-time PCR. Also, location of ganglion cells, photoreceptor cells, amacrine cells, and precursors of neuronal cell types in retinal tissue was stained by immunofluorescence after transportation. Furthermore, cell viability was assessed by CCK8 assay. RESULTS: Results showed transportation remarkably intensified expression of apoptotic factor cleaved caspase3, p53, NFkappaB, and TNF-a, which could be reduced by supplement of BAM15. In addition, neurons were severely injured after transportation, with axons manifesting disrupted and tortuous by staining NEFL. And the addition of BAM15 in transportation was able to protect neuronal structure and increase cell viability without affecting subtypes cells location of retinal tissue. CONCLUSIONS: BAM15 might be used as a protective reagent on apoptosis during transporting retinal tissues, holding great potential in research and clinical applications.
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Diferenciação Celular/efeitos dos fármacos , Diaminas/farmacologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Oxidiazóis/farmacologia , Substâncias Protetoras/farmacologia , Pirazinas/farmacologia , Retina/metabolismo , Meios de Transporte , Células Amácrinas/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Caspase 3/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Antígeno Ki-67/genética , Proteínas de Neurofilamentos/genética , Neurônios/efeitos dos fármacos , Células Fotorreceptoras/efeitos dos fármacos , Retina/efeitos dos fármacos , Retina/transplante , Células Ganglionares da Retina/efeitos dos fármacos , Manejo de Espécimes/métodos , Fator de Necrose Tumoral alfa/genética , Proteína Supressora de Tumor p53/genéticaRESUMO
BACKGROUND: To develop an effective surgical procedure for cellular scaffold epiretinal implantation in rhesus, facilitating subsequent epiretinal stem cell transplantation. METHODS: Retinal progenitors were seeded onto a poly(lactic-co-glycolic) acid (PLGA) scaffold. First, the cellular scaffolds were delivered by 18G catheter or retinal forceps into rabbit epiretinal space (n = 50). Then, the cell survival rate was evaluated by Cell Counting Kit-8 (CCK-8). Second, three methods of scaffold fixation, including adhesion after gas-liquid exchange (n = 1), tamponade by hydrogel (n = 1), and fixation by retinal tacks (n = 4), were performed in rhesus monkeys. After one month, fundus photography and SD-OCT were performed to assess the outcomes, and histological examination was performed to evaluate proliferation. RESULTS: The cell survival rate was significantly higher in the catheter group. Follow-up examination showed that retinal tack fixation was the only method to maintain the scaffolds attached to host retina for at least 3 weeks, which is the minimal time required for cell integration. Histological staining demonstrated slight glial fibrillary acidic protein (GFAP) accumulation in the retinal tack insertion area. CONCLUSIONS: The established surgical procedure offers a new insight into research of epiretinal cell replacement therapy in rhesus eyes. The successful delivery and long-term fixation provide a prerequisite for cell migration and integration.
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This study was conducted to investigate the use of Alpha 1-antitrypsin (AAT) to inhibit microglia activation in chronic hypertension model and provide a permissive environment for stem cell transplantation. Chronic ocular hypertension of C57BL/6 mice using magnetic microbead injection was induced 3â¯weeks prior to iPSCs transplantation. The ocular hypertension model was assessed histologically and intraocular pressure was measured. Survival of grafted cells and microglia activation were examined by flow cytometry and immunofluorescence in AAT and PBS treated hosts. Retinal cytokines expression was also detected by real-time PCR. Chronic ocular hypertension resulted in persistent microglia activation and stem cell grafts loss. AAT treatment significantly inhibited microglia activation and facilitated the survival of transplant iPSCs 4w post transplantation compared to PBS treatment. AAT holds tremendous potential for the clinical application to control neuroinflammation factor in glaucoma and improve the stem cell replacement therapy of retinal neurodegenerative disease.
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Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Hipertensão Ocular/terapia , alfa 1-Antitripsina/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Hipertensão/terapia , Pressão Intraocular/fisiologia , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Doenças Neurodegenerativas , Neuroimunomodulação/efeitos dos fármacos , Transplante de Células-Tronco/métodosRESUMO
Numerous therapeutic procedures in modern medical research rely on the use of tissue engineering for the treatment of retinal diseases. However, the cell source and the transplantation method are still a limitation. Previously, it was reported that a self-organizing three-dimensional neural retina can be induced from human-induced pluripotent stem cells (hiPSCs). In this study, we disclose the generation of retinal ganglion cells (RGCs) from the neural retina and their seeding on a biodegradable poly (lactic-co-glycolic acid) (PLGA) scaffold to create an engineered RGC-scaffold biomaterial. Moreover, we explored the dendritic arbor, branching point, functional axon and action potential of the biomaterial. Finally, the cell-scaffold was transplanted into the intraocular environment of rabbits and rhesus monkeys. STATEMENT OF SIGNIFICANCE: As a part of the mammalian central nervous system (CNS), the retinal ganglion cell (RGC) shows little regenerative capacity. With the use of medical biomaterial for cells seeding and deliver, a new domain is now emerging that uses tissue engineering therapy for retinal disease. However, previous studies utilized RGCs from rodent model, which has limitations for human disease treatment. In the present study, we generated RGCs from hiPSCs-3D neural retina and then seeded these RGCs on PLGA scaffold to create an engineered RGC-scaffold biomaterial. Moreover, we assessed the transplantation method for biomaterial in vivo. Our study provides a technique to produce the engineered human RGC-scaffold biomaterial.