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Rajendran Nair DS, Camarillo JCM, Lu G, Thomas BB. Measuring spatial visual loss in rats by retinotopic mapping of the superior colliculus using a novel multi-electrode array technique. J Neurosci Methods 2024; 405:110095. [PMID: 38403001 DOI: 10.1016/j.jneumeth.2024.110095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/06/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND The retinotopic map property of the superior colliculus (SC) is a reliable indicator of visual functional changes in rodents. Electrophysiological mapping of the SC using a single electrode has been employed for measuring visual function in rat and mouse disease models. Single electrode mapping is highly laborious requiring long-term exposure to the SC surface and prolonged anesthetic conditions that can adversely affect the mapping data. NEW METHOD To avoid the above-mentioned issues, we fabricated a fifty-six (56) electrode multi-electrode array (MEA) for rapid and reliable visual functional mapping of the SC. Since SC is a dome-shaped structure, the array was made of electrodes with dissimilar tip lengths to enable simultaneous and uniform penetration of the SC. RESULTS SC mapping using the new MEA was conducted in retinal degenerate (RD) Royal College of Surgeons (RCS) rats and rats with focal retinal damage induced by green diode laser. For SC mapping, the MEA was advanced into the SC surface and the visual activities were recorded during full-filed light stimulation of the eye. Based on the morphological examination, the MEA electrodes covered most of the exposed SC area and penetrated the SC surface at a relatively uniform depth. MEA mapping in RCS rats (n=9) demonstrated progressive development of a scotoma in the SC that corresponded to the degree of photoreceptor loss. MEA mapping in the laser damaged rats demonstrated the presence of a scotoma in the SC area that corresponded to the location of retinal laser injury. COMPARISON WITH EXISTING METHODS AND CONCLUSIONS The use of MEA for SC mapping is advantageous over single electrode recording by enabling faster recordings and reducing anesthesia time. This study establishes the feasibility of the MEA technique for rapid and efficient SC mapping, particularly advantageous for evaluating therapeutic effects in retinal degenerate rat disease models.
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Affiliation(s)
- Deepthi S Rajendran Nair
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States
| | - Juan Carlos-Martinez Camarillo
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, United States
| | - Gengxi Lu
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States
| | - Biju B Thomas
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, United States; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, United States.
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Ahluwalia K, Du Z, Martinez-Camarillo JC, Naik A, Thomas BB, Pollalis D, Lee SY, Dave P, Zhou E, Li Z, Chester C, Humayun MS, Louie SG. Unveiling Drivers of Retinal Degeneration in RCS Rats: Functional, Morphological, and Molecular Insights. Int J Mol Sci 2024; 25:3749. [PMID: 38612560 PMCID: PMC11011632 DOI: 10.3390/ijms25073749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/12/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024] Open
Abstract
Retinal degenerative diseases, including age-related macular degeneration and retinitis pigmentosa, significantly contribute to adult blindness. The Royal College of Surgeons (RCS) rat is a well-established disease model for studying these dystrophies; however, molecular investigations remain limited. We conducted a comprehensive analysis of retinal degeneration in RCS rats, including an immunodeficient RCS (iRCS) sub-strain, using ocular coherence tomography, electroretinography, histology, and molecular dissection using transcriptomics and immunofluorescence. No significant differences in retinal degeneration progression were observed between the iRCS and immunocompetent RCS rats, suggesting a minimal role of adaptive immune responses in disease. Transcriptomic alterations were primarily in inflammatory signaling pathways, characterized by the strong upregulation of Tnfa, an inflammatory signaling molecule, and Nox1, a contributor to reactive oxygen species (ROS) generation. Additionally, a notable decrease in Alox15 expression was observed, pointing to a possible reduction in anti-inflammatory and pro-resolving lipid mediators. These findings were corroborated by immunostaining, which demonstrated increased photoreceptor lipid peroxidation (4HNE) and photoreceptor citrullination (CitH3) during retinal degeneration. Our work enhances the understanding of molecular changes associated with retinal degeneration in RCS rats and offers potential therapeutic targets within inflammatory and oxidative stress pathways for confirmatory research and development.
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Affiliation(s)
- Kabir Ahluwalia
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Zhaodong Du
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
| | - Juan Carlos Martinez-Camarillo
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Aditya Naik
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Biju B. Thomas
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Dimitrios Pollalis
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Sun Young Lee
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- Department of Physiology & Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Priyal Dave
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Eugene Zhou
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Zeyang Li
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Catherine Chester
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
| | - Mark S. Humayun
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Stan G. Louie
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.); (P.D.); (E.Z.); (Z.L.); (C.C.)
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (Z.D.); (J.C.M.-C.); (B.B.T.); (D.P.); (S.Y.L.); (M.S.H.)
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3
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Pollalis D, Calle AG, Martinez-Camarillo JC, Ahluwalia K, Hinman C, Mitra D, Lebkowski J, Lee SY, Thomas BB, Ahmed F, Chan V, Junge JA, Fraser S, Louie S, Humayun M. Scaling up polarized RPE cell supernatant production on parylene membrane. Exp Eye Res 2024; 240:109789. [PMID: 38242423 DOI: 10.1016/j.exer.2024.109789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/21/2024]
Abstract
Age-related macular degeneration (AMD), a leading cause of vision loss, primarily arises from the degeneration of retinal pigment epithelium (RPE) and photoreceptors. Current therapeutic options for dry AMD are limited. Encouragingly, cultured RPE cells on parylene-based biomimetic Bruch's membrane demonstrate characteristics akin to the native RPE layer. In this study, we cultivated human embryonic stem cell-derived polarized RPE (hESC-PRPE) cells on parylene membranes at both small- and large-scale settings, collecting conditioned supernatant, denoted as PRPE-SF. We conducted a comprehensive analysis of the morphology of the cultured hESC-RPE cells and the secreted growth factors in PRPE-SF. To evaluate the in vivo efficacy of these products, the product was administered via intravitreal injections of PRPE-SF in immunodeficient Royal College of Surgeons (iRCS) rats, a model for retinal degeneration. Our study not only demonstrated the scalability of PRPE-SF production while maintaining RPE cell phenotype but also showed consistent protein concentrations between small- and large-scale batches. We consistently identified 10 key factors in PRPE-SF, including BMP-7, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, MANF, PEDF, PDGF-AA, TGFβ1, and VEGF. Following intravitreal administration of PRPE-SF, we observed a significant increase in the thickness of the outer nuclear layer (ONL) and photoreceptor preservation in iRCS rats. Furthermore, correlation analysis revealed that IGFBP-3, IGFBP-4, MANF, PEDF, and TGFβ1 displayed positive associations with in vivo bioactivity, while GDF-15 exhibited a negative correlation. Overall, this study highlights the feasibility of scaling up PRPE-SF production on parylene membranes without compromising its essential constituents. The outcomes of PRPE-SF administration in an animal model of retinal degeneration present substantial potential for photoreceptor preservation. Moreover, the identification of candidate surrogate potency markers, showing strong positive associations with in vivo bioactivity, lays a solid foundation for the development of a promising therapeutic intervention for retinal degenerative diseases.
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Affiliation(s)
- Dimitrios Pollalis
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Alejandra Gonzalez Calle
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Juan Carlos Martinez-Camarillo
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Kabir Ahluwalia
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; USC Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Cassidy Hinman
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Debbie Mitra
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Jane Lebkowski
- Regenerative Patch Technologies LLC, Menlo Park, CA 94028, USA
| | - Sun Young Lee
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B Thomas
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Faizah Ahmed
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Victoria Chan
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Jason A Junge
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Scott Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Stan Louie
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; USC Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Mark Humayun
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA.
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Zhang J, Gong C, Yang Z, Wei F, Sun X, Ji J, Zeng Y, Chang CF, Liu X, Nair DSR, Thomas BB, Zhou Q. Ultrasound Flow Imaging Study on Rat Brain with Ultrasound and Light Stimulations. Bioengineering (Basel) 2024; 11:174. [PMID: 38391660 PMCID: PMC10886342 DOI: 10.3390/bioengineering11020174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/29/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024] Open
Abstract
Functional ultrasound (fUS) flow imaging provides a non-invasive method for the in vivo study of cerebral blood flow and neural activity. This study used functional flow imaging to investigate rat brain's response to ultrasound and colored-light stimuli. Male Long-Evan rats were exposed to direct full-field strobe flashes light and ultrasound stimulation to their retinas, while brain activity was measured using high-frequency ultrasound imaging. Our study found that light stimuli, particularly blue light, elicited strong responses in the visual cortex and lateral geniculate nucleus (LGN), as evidenced by changes in cerebral blood volume (CBV). In contrast, ultrasound stimulation elicited responses undetectable with fUS flow imaging, although these were observable when directly measuring the brain's electrical signals. These findings suggest that fUS flow imaging can effectively differentiate neural responses to visual stimuli, with potential applications in understanding visual processing and developing new diagnostic tools.
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Affiliation(s)
- Junhang Zhang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
| | - Chen Gong
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
| | - Zihan Yang
- Caruso Department of Otolaryngology-Head & Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA
| | - Fan Wei
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Xin Sun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Jie Ji
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Yushun Zeng
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Chi-Feng Chang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
| | - Xunan Liu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Deepthi S Rajendran Nair
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B Thomas
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA
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Lu JY, Lu G, Thomas BB, Humayun MS, Zhou Q. Ultrasound Concave 2-D Ring Array for Retinal Stimulation. IEEE Trans Ultrason Ferroelectr Freq Control 2023; 70:1527-1535. [PMID: 37792653 PMCID: PMC10657748 DOI: 10.1109/tuffc.2023.3321871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
An ultrasound concave 2-D ring array transducer was designed for applications in visual stimulation of the retina with a long-term goal to restore vision in individuals with intact neurons but suffering blindness due to retinopathies. The array was synthesized and has a frequency of 20 MHz (0.075-mm wavelengths in water), 18-mm focal length (the curvature of the concave array), 1004 elements (with a pitch of 4.0 wavelengths), and inner and outer diameters of 9 and 14 mm, respectively. Wave patterns produced with the array at the focal distance were simulated. Results show that the wave patterns obtained can achieve a full-width-at-half-maximum (FWHM) resolution of 0.147 mm that is very close to the FWHM diffraction limit (0.136 mm). In addition, a scaled experiment at a lower frequency of 2.5 MHz was performed. The result is very close to those obtained with the simulations.
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Ahluwalia K, Martinez-Camarillo JC, Thomas BB, Naik A, Gonzalez-Calle A, Pollalis D, Lebkowski J, Lee SY, Mitra D, Louie SG, Humayun MS. Polarized RPE Secretome Preserves Photoreceptors in Retinal Dystrophic RCS Rats. Cells 2023; 12:1689. [PMID: 37443724 PMCID: PMC10340490 DOI: 10.3390/cells12131689] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Retinal degenerative diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa, lack effective therapies. Conventional monotherapeutic approaches fail to target the multiple affected pathways in retinal degeneration. However, the retinal pigment epithelium (RPE) secretes several neurotrophic factors addressing diverse cellular pathways, potentially preserving photoreceptors. This study explored human embryonic stem cell-derived, polarized RPE soluble factors (PRPE-SF) as a combination treatment for retinal degeneration. PRPE-SF promoted retinal progenitor cell survival, reduced oxidative stress in ARPE-19 cells, and demonstrated critical antioxidant and anti-inflammatory effects for preventing retinal degeneration in the Royal College of Surgeons (RCS) rat model. Importantly, PRPE-SF treatment preserved retinal structure and scotopic b-wave amplitudes, suggesting therapeutic potential for delaying retinal degeneration. PRPE-SF is uniquely produced using biomimetic membranes for RPE polarization and maturation, promoting a protective RPE secretome phenotype. Additionally, PRPE-SF is produced without animal serum to avoid immunogenicity in future clinical development. Lastly, PRPE-SF is a combination of neurotrophic factors, potentially ameliorating multiple dysfunctions in retinal degenerations. In conclusion, PRPE-SF offers a promising therapeutic candidate for retinal degenerative diseases, advancing the development of effective therapeutic strategies for these debilitating conditions.
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Affiliation(s)
- Kabir Ahluwalia
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.)
| | - Juan-Carlos Martinez-Camarillo
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Aditya Naik
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.)
| | - Alejandra Gonzalez-Calle
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Dimitrios Pollalis
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jane Lebkowski
- Regenerative Patch Technologies LLC, Menlo Park, CA 94028, USA;
| | - Sun Young Lee
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- Department of Physiology & Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Debbie Mitra
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
| | - Stan G. Louie
- Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA; (K.A.); (A.N.)
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
| | - Mark S. Humayun
- USC Ginsburg Institute of for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; (J.-C.M.-C.); (B.B.T.); (A.G.-C.); (D.P.); (S.Y.L.); (D.M.)
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Gong C, Li R, Lu G, Ji J, Zeng Y, Chen J, Chang C, Zhang J, Xia L, Nair DSR, Thomas BB, Song BJ, Humayun MS, Zhou Q. Non-Invasive Hybrid Ultrasound Stimulation of Visual Cortex In Vivo. Bioengineering (Basel) 2023; 10:bioengineering10050577. [PMID: 37237647 DOI: 10.3390/bioengineering10050577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/06/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
The optic nerve is the second cranial nerve (CN II) that connects and transmits visual information between the retina and the brain. Severe damage to the optic nerve often leads to distorted vision, vision loss, and even blindness. Such damage can be caused by various types of degenerative diseases, such as glaucoma and traumatic optic neuropathy, and result in an impaired visual pathway. To date, researchers have not found a viable therapeutic method to restore the impaired visual pathway; however, in this paper, a newly synthesized model is proposed to bypass the damaged portion of the visual pathway and set up a direct connection between a stimulated visual input and the visual cortex (VC) using Low-frequency Ring-transducer Ultrasound Stimulation (LRUS). In this study, by utilizing and integrating various advanced ultrasonic and neurological technologies, the following advantages are achieved by the proposed LRUS model: 1. This is a non-invasive procedure that uses enhanced sound field intensity to overcome the loss of ultrasound signal due to the blockage of the skull. 2. The simulated visual signal generated by LRUS in the visual-cortex-elicited neuronal response in the visual cortex is comparable to light stimulation of the retina. The result was confirmed by a combination of real-time electrophysiology and fiber photometry. 3. VC showed a faster response rate under LRUS than light stimulation through the retina. These results suggest a potential non-invasive therapeutic method for restoring vision in optic-nerve-impaired patients using ultrasound stimulation (US).
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Affiliation(s)
- Chen Gong
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Runze Li
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Gengxi Lu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Jie Ji
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Yushun Zeng
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiawen Chen
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Chifeng Chang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Junhang Zhang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Lily Xia
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Deepthi S Rajendran Nair
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B Thomas
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Brian J Song
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Mark S Humayun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
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Martinez Camarillo JC, Hu Y, Thomas BB, Zhu D, Hinton DR, Mitra D, Mora Correa JM, Rajendran Nair DS, Lebkowski J, Humayun MS. Development of a Surgical Technique for Subretinal Implants in Rats. J Vis Exp 2022. [DOI: 10.3791/64585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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9
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Lu G, Qian X, Gong C, Ji J, Thomas BB, Humayun MS, Zhou Q. Ultrasound Retinal Stimulation: A Mini-Review of Recent Developments. IEEE Trans Ultrason Ferroelectr Freq Control 2022; 69:3224-3231. [PMID: 36343006 PMCID: PMC10424795 DOI: 10.1109/tuffc.2022.3220568] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Ultrasound neuromodulation is an emerging technology. A significant amount of effort has been devoted to investigating the feasibility of noninvasive ultrasound retinal stimulation. Recent studies have shown that ultrasound can activate neurons in healthy and degenerated retinas. Specifically, high-frequency ultrasound can evoke localized neuron responses and generate patterns in visual circuits. In this review, we recapitulate pilot studies on ultrasound retinal stimulation, compare it with other neuromodulation technologies, and discuss its advantages and limitations. An overview of the opportunities and challenges to develop a noninvasive retinal prosthesis using high-frequency ultrasound is also provided.
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10
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Ahmed F, Rajendran Nair DS, Thomas BB. A New Optokinetic Testing Method to Measure Rat Vision. J Vis Exp 2022. [PMID: 35969051 PMCID: PMC10081576 DOI: 10.3791/63357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Optokinetic nystagmus (OKN) is a reflexive eye movement initiated by the motion of visual stimuli in the field of vision. The head-tracking movement associated with OKN is commonly used as a measure of visual function in rodents. To record OKN responses in normal and experimental rats, a simple and inexpensive apparatus has been developed. This setup uses two tablet screens to display the OKN visual stimulus consisting of high contrast black and white stripes generated using the OKN Stripes Visualization Web Application, a freely available software. The rat is placed inside a clear Plexiglass holder that limits movement so that the rat's head continuously faces the OKN display screen. The position of the rat holder can be changed to adjust the distance between the rat and the display screen. A micro-camera positioned above the rat holder is used to record the rat's visual activities. These recordings can be used for quantitative assessments. Based on the presence or absence of clear head-tracking, the OKN responses at different spatial frequencies can be determined. The collected data demonstrates a novel technique for reliable measurement of visual acuity in normal and retinal degenerate rats.
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Affiliation(s)
- Faizah Ahmed
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California
| | - Deepthi S Rajendran Nair
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California
| | - Biju B Thomas
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California;
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11
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Qian X, Lu G, Thomas BB, Li R, Chen X, Shung KK, Humayun M, Zhou Q. Noninvasive Ultrasound Retinal Stimulation for Vision Restoration at High Spatiotemporal Resolution. BME Front 2022; 2022:9829316. [PMID: 37850175 PMCID: PMC10521738 DOI: 10.34133/2022/9829316] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/05/2022] [Indexed: 10/19/2023] Open
Abstract
Objective. Retinal degeneration involving progressive deterioration and loss of function of photoreceptors is a major cause of permanent vision loss worldwide. Strategies to treat these incurable conditions incorporate retinal prostheses via electrically stimulating surviving retinal neurons with implanted devices in the eye, optogenetic therapy, and sonogenetic therapy. Existing challenges of these strategies include invasive manner, complex implantation surgeries, and risky gene therapy. Methods and Results. Here, we show that direct ultrasound stimulation on the retina can evoke neuron activities from the visual centers including the superior colliculus and the primary visual cortex (V1), in either normal-sighted or retinal degenerated blind rats in vivo. The neuron activities induced by the customized spherically focused 3.1 MHz ultrasound transducer have shown both good spatial resolution of 250 μm and temporal resolution of 5 Hz in the rat visual centers. An additional customized 4.4 MHz helical transducer was further implemented to generate a static stimulation pattern of letter forms. Conclusion. Our findings demonstrate that ultrasound stimulation of the retina in vivo is a safe and effective approach with high spatiotemporal resolution, indicating a promising future of ultrasound stimulation as a novel and noninvasive visual prosthesis for translational applications in blind patients.
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Affiliation(s)
- Xuejun Qian
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Gengxi Lu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Runze Li
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Xiaoyang Chen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - K. Kirk Shung
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Mark Humayun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
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12
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Nair DSR, Thomas BB. Stem Cell-based Treatment Strategies for Degenerative Diseases of the Retina. Curr Stem Cell Res Ther 2022; 17:214-225. [PMID: 34348629 PMCID: PMC9129886 DOI: 10.2174/1574888x16666210804112104] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/18/2021] [Accepted: 05/26/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND The main cause of progressive vision impairment in retinal degenerative diseases is the dysfunction of photoreceptors and the underlying retinal pigment epithelial cells. The inadequate regenerative capacity of the neural retina and lack of established therapeutic options demand the development of clinical-grade protocols to halt the degenerative process in the eye or replace the damaged cells by using stem cell-derived products. Recently, stem cell-based regenerative therapies have been at the forefront of clinical investigations for retinal dystrophies. OBJECTIVE This article will review different stem cell-based therapies currently employed for retinal degenerative diseases, recent clinical trials, and major challenges in the translation of these therapies from bench to bedside. METHODOLOGY A systematic literature review was conducted to identify potentially relevant articles published in MEDLINE/PubMed, Embase, ClinicalTrials.gov, Drugs@FDA, European Medicines Agency, and World Health Organization International Clinical Trials Registry Platform. RESULTS Transplantation of healthy cells to replace damaged cells in the outer retina is a clinically relevant concept because the inner retina that communicates with the visual areas of the brain remains functional even after the photoreceptors are completely lost. Various methods have been established for the differentiation of pluripotent stem cells into different retinal cell types that can be used for therapies. Factors released from transplanted somatic stem cells showed trophic support and photoreceptor rescue during the early stages of the disease. Several preclinical and phase I/II clinical studies using terminally differentiated photoreceptor/retinal pigment epithelial cells derived from pluripotent stem cells have shown proof of concept for visual restoration in Age-related Macular Degeneration (AMD), Stargardt disease, and Retinitis Pigmentosa (RP). CONCLUSION Cell replacement therapy has great potential for vision restoration. The results obtained from the initial clinical trials are encouraging and indicate its therapeutic benefits. The current status of the therapies suggests that there is a long way to go before these results can be applied to routine clinical practice. Input from the ongoing multicentre clinical trials will give a more refined idea for the future design of clinical-grade protocols to transplant GMP level HLA matched cells.
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Affiliation(s)
- Deepthi S. Rajendran Nair
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Biju B. Thomas
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA,USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, California, USA,Correspondence: , Tel: 323-442-5593
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13
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Rajendran Nair DS, Zhu D, Sharma R, Martinez Camarillo JC, Bharti K, Hinton DR, Humayun MS, Thomas BB. Long-Term Transplant Effects of iPSC-RPE Monolayer in Immunodeficient RCS Rats. Cells 2021; 10:cells10112951. [PMID: 34831174 PMCID: PMC8616297 DOI: 10.3390/cells10112951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 12/29/2022] Open
Abstract
Retinal pigment epithelium (RPE) replacement therapy is evolving as a feasible approach to treat age-related macular degeneration (AMD). In many preclinical studies, RPE cells are transplanted as a cell suspension into immunosuppressed animal eyes and transplant effects have been monitored only short-term. We investigated the long-term effects of human Induced pluripotent stem-cell-derived RPE (iPSC-RPE) transplants in an immunodeficient Royal College of Surgeons (RCS) rat model, in which RPE dysfunction led to photoreceptor degeneration. iPSC-RPE cultured as a polarized monolayer on a nanoengineered ultrathin parylene C scaffold was transplanted into the subretinal space of 28-day-old immunodeficient RCS rat pups and evaluated after 1, 4, and 11 months. Assessment at early time points showed good iPSC-RPE survival. The transplants remained as a monolayer, expressed RPE-specific markers, performed phagocytic function, and contributed to vision preservation. At 11-months post-implantation, RPE survival was observed in only 50% of the eyes that were concomitant with vision preservation. Loss of RPE monolayer characteristics at the 11-month time point was associated with peri-membrane fibrosis, immune reaction through the activation of macrophages (CD 68 expression), and the transition of cell fate (expression of mesenchymal markers). The overall study outcome supports the therapeutic potential of RPE grafts despite the loss of some transplant benefits during long-term observations.
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Affiliation(s)
- Deepthi S. Rajendran Nair
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
| | - Danhong Zhu
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.Z.); (D.R.H.)
| | - Ruchi Sharma
- Unit on Ocular and Stem Cell Translational Research, National Eye Institute, NIH, Bethesda, MD 20892, USA; (R.S.); (K.B.)
| | - Juan Carlos Martinez Camarillo
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Kapil Bharti
- Unit on Ocular and Stem Cell Translational Research, National Eye Institute, NIH, Bethesda, MD 20892, USA; (R.S.); (K.B.)
| | - David R. Hinton
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.Z.); (D.R.H.)
| | - Mark S. Humayun
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
- Correspondence: ; Tel.: +1-323-442-5593
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14
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Thomas BB, Lin B, Martinez-Camarillo JC, Zhu D, McLelland BT, Nistor G, Keirstead HS, Humayun MS, Seiler MJ. Co-grafts of Human Embryonic Stem Cell Derived Retina Organoids and Retinal Pigment Epithelium for Retinal Reconstruction in Immunodeficient Retinal Degenerate Royal College of Surgeons Rats. Front Neurosci 2021; 15:752958. [PMID: 34764853 PMCID: PMC8576198 DOI: 10.3389/fnins.2021.752958] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/04/2021] [Indexed: 12/15/2022] Open
Abstract
End-stage age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are two major retinal degenerative (RD) conditions that result in irreversible vision loss. Permanent eye damage can also occur in battlefields or due to accidents. This suggests there is an unmet need for developing effective strategies for treating permanent retinal damages. In previous studies, co-grafted sheets of fetal retina with its retinal pigment epithelium (RPE) have demonstrated vision improvement in rat retinal disease models and in patients, but this has not yet been attempted with stem-cell derived tissue. Here we demonstrate a cellular therapy for irreversible retinal eye injuries using a "total retina patch" consisting of retinal photoreceptor progenitor sheets and healthy RPE cells on an artificial Bruch's membrane (BM). For this, retina organoids (ROs) (cultured in suspension) and polarized RPE sheets (cultured on an ultrathin parylene substrate) were made into a co-graft using bio-adhesives [gelatin, growth factor-reduced matrigel, and medium viscosity (MVG) alginate]. In vivo transplantation experiments were conducted in immunodeficient Royal College of Surgeons (RCS) rats at advanced stages of retinal degeneration. Structural reconstruction of the severely damaged retina was observed based on histological assessments and optical coherence tomography (OCT) imaging. Visual functional assessments were conducted by optokinetic behavioral testing and superior colliculus electrophysiology. Long-term survival of the co-graft in the rat subretinal space and improvement in visual function were observed. Immunohistochemistry showed that co-grafts grew, generated new photoreceptors and developed neuronal processes that were integrated into the host retina. This novel approach can be considered as a new therapy for complete replacement of a degenerated retina.
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Affiliation(s)
- Biju B. Thomas
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, United States
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, United States
| | - Bin Lin
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, Irvine, CA, United States
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States
| | - Juan Carlos Martinez-Camarillo
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, United States
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, United States
| | - Danhong Zhu
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, United States
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Bryce T. McLelland
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, Irvine, CA, United States
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States
| | | | | | - Mark S. Humayun
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, United States
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, United States
| | - Magdalene J. Seiler
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, Irvine, CA, United States
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States
- Department of Ophthalmology, University of California, Irvine, Irvine, CA, United States
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA, United States
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15
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Lin B, McLelland BT, Aramant RB, Thomas BB, Nistor G, Keirstead HS, Seiler MJ. Retina Organoid Transplants Develop Photoreceptors and Improve Visual Function in RCS Rats With RPE Dysfunction. Invest Ophthalmol Vis Sci 2021; 61:34. [PMID: 32945842 PMCID: PMC7509771 DOI: 10.1167/iovs.61.11.34] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose To study if human embryonic stem cell-derived photoreceptors could survive and function without the support of retinal pigment epithelium (RPE) after transplantation into Royal College of Surgeons rats, a rat model of retinal degeneration caused by RPE dysfunction. Methods CSC14 human embryonic stem cells were differentiated into primordial eye structures called retinal organoids. Retinal organoids were analyzed by quantitative PCR and immunofluorescence and compared with human fetal retina. Retinal organoid sheets (30-70 day of differentiation) were transplanted into immunodeficient RCS rats, aged 44 to 56 days. The development of transplant organoids in vivo in relation to the host was examined by optical coherence tomography. Visual function was assessed by optokinetic testing, electroretinogram, and superior colliculus electrophysiologic recording. Cryostat sections were analyzed for various retinal, synaptic, and donor markers. Results Retinal organoids showed similar gene expression to human fetal retina transplanted rats demonstrated significant improvement in visual function compared with RCS nonsurgery and sham surgery controls by ERGs at 2 months after surgery (but not later), optokinetic testing (up to 6 months after surgery) and electrophysiologic superior colliculus recordings (6-8 months after surgery). The transplanted organoids survived more than 7 months; developed photoreceptors with inner and outer segments, and other retinal cells; and were well-integrated within the host. Conclusions This study, to our knowledge, is the first to show that transplanted photoreceptors survive and function even with host's dysfunctional RPE. Our findings suggest that transplantation of organoid sheets from stem cells may be a promising approach/therapeutic for blinding diseases.
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Affiliation(s)
- Bin Lin
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Bryce T McLelland
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Robert B Aramant
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Biju B Thomas
- USC Roski Eye Institute, Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
| | - Gabriel Nistor
- AIVITA Biomedical Inc., Irvine, California, United States
| | | | - Magdalene J Seiler
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States.,Ophthalmology, University of California at Irvine, School of Medicine, Irvine, California, United States.,Anatomy & Neurobiology, University of California at Irvine School of Medicine, Irvine, California, United States
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16
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Pennington BO, Bailey JK, Faynus MA, Hinman C, Hee MN, Ritts R, Nadar V, Zhu D, Mitra D, Martinez-Camarillo JC, Lin TC, Thomas BB, Hinton DR, Humayun MS, Lebkowski J, Johnson LV, Clegg DO. Xeno-free cryopreservation of adherent retinal pigmented epithelium yields viable and functional cells in vitro and in vivo. Sci Rep 2021; 11:6286. [PMID: 33737600 PMCID: PMC7973769 DOI: 10.1038/s41598-021-85631-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/03/2021] [Indexed: 01/31/2023] Open
Abstract
Age-related macular degeneration (AMD) is the primary cause of blindness in adults over 60 years of age, and clinical trials are currently assessing the therapeutic potential of retinal pigmented epithelial (RPE) cell monolayers on implantable scaffolds to treat this disease. However, challenges related to the culture, long-term storage, and long-distance transport of such implants currently limit the widespread use of adherent RPE cells as therapeutics. Here we report a xeno-free protocol to cryopreserve a confluent monolayer of clinical-grade, human embryonic stem cell-derived RPE cells on a parylene scaffold (REPS) that yields viable, polarized, and functional RPE cells post-thaw. Thawed cells exhibit ≥ 95% viability, have morphology, pigmentation, and gene expression characteristic of mature RPE cells, and secrete the neuroprotective protein, pigment epithelium-derived factor (PEDF). Stability under liquid nitrogen (LN2) storage has been confirmed through one year. REPS were administered immediately post-thaw into the subretinal space of a mammalian model, the Royal College of Surgeons (RCS)/nude rat. Implanted REPS were assessed at 30, 60, and 90 days post-implantation, and thawed cells demonstrate survival as an intact monolayer on the parylene scaffold. Furthermore, immunoreactivity for the maturation marker, RPE65, significantly increased over the post-implantation period in vivo, and cells demonstrated functional attributes similar to non-cryopreserved controls. The capacity to cryopreserve adherent cellular therapeutics permits extended storage and stable transport to surgical sites, enabling broad distribution for the treatment of prevalent diseases such as AMD.
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Affiliation(s)
- Britney O. Pennington
- grid.133342.40000 0004 1936 9676Center for Stem Cell Biology and Engineering, Neuroscience Research Institute, University of California, 6131 Biology 2 Bldg 571, NRI, UC Santa Barbara, Santa Barbara, CA 93106 USA ,Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | - Jeffrey K. Bailey
- grid.133342.40000 0004 1936 9676Center for Stem Cell Biology and Engineering, Neuroscience Research Institute, University of California, 6131 Biology 2 Bldg 571, NRI, UC Santa Barbara, Santa Barbara, CA 93106 USA ,Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | - Mohamed A. Faynus
- grid.133342.40000 0004 1936 9676Center for Stem Cell Biology and Engineering, Neuroscience Research Institute, University of California, 6131 Biology 2 Bldg 571, NRI, UC Santa Barbara, Santa Barbara, CA 93106 USA ,Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | - Cassidy Hinman
- grid.133342.40000 0004 1936 9676Center for Stem Cell Biology and Engineering, Neuroscience Research Institute, University of California, 6131 Biology 2 Bldg 571, NRI, UC Santa Barbara, Santa Barbara, CA 93106 USA ,Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | - Mitchell N. Hee
- grid.133342.40000 0004 1936 9676College of Creative Studies, Biology, University of California, Santa Barbara, CA USA
| | - Rory Ritts
- grid.133342.40000 0004 1936 9676Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, CA USA
| | - Vignesh Nadar
- Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | - Danhong Zhu
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - Debbie Mitra
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - Juan Carlos Martinez-Camarillo
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA USA
| | - Tai-Chi Lin
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - Biju B. Thomas
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA USA
| | - David R. Hinton
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA USA
| | - Mark S. Humayun
- grid.42505.360000 0001 2156 6853Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853Department of Biomedical Engineering, Denney Research Center (DRB) of the University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA USA
| | - Jane Lebkowski
- Regenerative Patch Technologies LLC, Portola Valley, CA USA
| | | | - Dennis O. Clegg
- grid.133342.40000 0004 1936 9676Center for Stem Cell Biology and Engineering, Neuroscience Research Institute, University of California, 6131 Biology 2 Bldg 571, NRI, UC Santa Barbara, Santa Barbara, CA 93106 USA ,Regenerative Patch Technologies LLC, Portola Valley, CA USA ,grid.133342.40000 0004 1936 9676Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, CA USA
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Abstract
The retina is a complex and fragile photosensitive part of the central nervous system which is prone to degenerative diseases leading to permanent vision loss. No proven treatment strategies exist to treat or reverse the degenerative conditions. Recent investigations demonstrate that cell transplantation therapies to replace the dysfunctional retinal pigment epithelial (RPE) cells and or the degenerating photoreceptors (PRs) are viable options to restore vision. Pluripotent stem cells, retinal progenitor cells, and somatic stem cells are the main cell sources used for cell transplantation therapies. The success of retinal transplantation based on cell suspension injection is hindered by limited cell survival and lack of cellular integration. Recent advances in material science helped to develop strategies to grow cells as intact monolayers or as sheets on biomaterial scaffolds for transplantation into the eyes. Such implants are found to be more promising than the bolus injection approach. Tissue engineering techniques are specifically designed to construct biodegradable or non-degradable polymer scaffolds to grow cells as a monolayer and construct implantable grafts. The engineered cell construct along with the extracellular matrix formed, can hold the cells in place to enable easy survival, better integration, and improved visual function. This article reviews the advances in the use of scaffolds for transplantation studies in animal models and their application in current clinical trials.
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Affiliation(s)
- Deepthi S. Rajendran Nair
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Magdalene J. Seiler
- Departments of Physical Medicine & Rehabilitation, Ophthalmology, Anatomy & Neurobiology, Sue and Bill Gross Stem Cell Research Centre, University of California, Irvine, CA 92697-1705, USA
| | - Kahini H. Patel
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Vinoy Thomas
- Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Juan Carlos Martinez Camarillo
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Mark S. Humayun
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
- Correspondence:
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Lu G, Qian X, Castillo J, Li R, Jiang L, Lu H, Kirk Shung K, Humayun MS, Thomas BB, Zhou Q. Transcranial Focused Ultrasound for Noninvasive Neuromodulation of the Visual Cortex. IEEE Trans Ultrason Ferroelectr Freq Control 2021; 68:21-28. [PMID: 32746196 PMCID: PMC8153235 DOI: 10.1109/tuffc.2020.3005670] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Currently, blindness cannot be cured and patients' living quality can be compromised severely. Ultrasonic (US) neuromodulation is a promising technology for the development of noninvasive cortical visual prosthesis. We investigated the feasibility of transcranial focused ultrasound (tFUS) for noninvasive stimulation of the visual cortex (VC) to develop improved visual prosthesis. tFUS was used to successfully evoke neural activities in the VC of both normal and retinal degenerate (RD) blind rats. Our results showed that blind rats showed more robust responses to ultrasound stimulation when compared with normal rats. ( , two-sample t-test). Three different types of ultrasound waveforms were used in the three experimental groups. Different types of cortical activities were observed when different US waveforms were used. In all rats, when stimulated with continuous ultrasound waves, only short-duration responses were observed at "US on and off" time points. In comparison, pulsed waves (PWs) evoked longer low-frequency responses. Testing different parameters of PWs showed that a pulse repetition frequency higher than 100 Hz is required to obtain the low-frequency responses. Based on the observed cortical activities, we inferred that acoustic radiation force (ARF) is the predominant physical mechanism of ultrasound neuromodulation.
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McLelland BT, Lin B, Mathur A, Aramant RB, Thomas BB, Nistor G, Keirstead HS, Seiler MJ. Transplanted hESC-Derived Retina Organoid Sheets Differentiate, Integrate, and Improve Visual Function in Retinal Degenerate Rats. Invest Ophthalmol Vis Sci 2019; 59:2586-2603. [PMID: 29847666 PMCID: PMC5968836 DOI: 10.1167/iovs.17-23646] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose To investigate whether sheets of retina organoids derived from human embryonic stem cells (hESCs) can differentiate, integrate, and improve visual function in an immunodeficient rat model of severe retinal degeneration (RD). Methods 3D hESC-derived retina organoids were analyzed by quantitative PCR and immunofluorescence. Sheets dissected from retina organoids (30–65 days of differentiation) were transplanted into the subretinal space of immunodeficient rho S334ter-3 rats. Visual function was tested by optokinetic testing and electrophysiologic recording in the superior colliculus. Transplants were analyzed at 54 to 300 days postsurgery by immunohistochemistry for donor and retinal markers. Results Retina organoids contained multiple retinal cell types, including progenitor populations capable of developing new cones and rods. After transplantation into an immunodeficient rat model of severe RD, the transplanted sheets differentiated, integrated, and produced functional photoreceptors and other retinal cells, according to the longer human developmental timetable. Maturation of the transplanted retinal cells created visual improvements that were measured by optokinetic testing and electrophysiologic recording in the superior colliculus. Immunohistochemistry analysis indicated that the donor cells were synaptically active. Extensive transplant projections could be seen within the host RD retina. Optical coherence tomography imaging monitored long-term transplant growth and survival up to 10 months postsurgery. Conclusions These data demonstrate that the transplantation of sheets dissected from hESC-derived retina organoids is a potential therapeutic method for restoring vision in advanced stages of RD.
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Affiliation(s)
- Bryce T McLelland
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California Irvine, School of Medicine, Irvine, California, United States
| | - Bin Lin
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California Irvine, School of Medicine, Irvine, California, United States
| | - Anuradha Mathur
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California Irvine, School of Medicine, Irvine, California, United States
| | - Robert B Aramant
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California Irvine, School of Medicine, Irvine, California, United States
| | - Biju B Thomas
- University of Southern California Roski Eye Institute, Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
| | - Gabriel Nistor
- AIVITA Biomedical, Inc., Irvine, California, United States
| | | | - Magdalene J Seiler
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California Irvine, School of Medicine, Irvine, California, United States
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Thomas BB, Zhu D, Lin TC, Kim YC, Seiler MJ, Martinez-Camarillo JC, Lin B, Shad Y, Hinton DR, Humayun MS. A new immunodeficient retinal dystrophic rat model for transplantation studies using human-derived cells. Graefes Arch Clin Exp Ophthalmol 2018; 256:2113-2125. [PMID: 30215097 DOI: 10.1007/s00417-018-4134-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 08/28/2018] [Accepted: 09/03/2018] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To create new immunodeficient Royal College of Surgeons (RCS) rats by introducing the defective MerTK gene into athymic nude rats. METHODS Female homozygous RCS (RCS-p+/RCS-p+) and male nude rats (Hsd:RH-Foxn1mu, mutation in the foxn1 gene; no T cells) were crossed to produce heterozygous F1 progeny. Double homozygous F2 progeny obtained by crossing the F1 heterozygotes was identified phenotypically (hair loss) and genotypically (RCS-p+ gene determined by PCR). Retinal degenerative status was confirmed by optical coherence tomography (OCT) imaging, electroretinography (ERG), optokinetic (OKN) testing, superior colliculus (SC) electrophysiology, and by histology. The effect of xenografts was assessed by transplantation of human embryonic stem cell-derived retinal pigment epithelium (hESC-RPE) and human-induced pluripotent stem cell-derived RPE (iPS-RPE) into the eye. Morphological analysis was conducted based on hematoxylin and eosin (H&E) and immunostaining. Age-matched pigmented athymic nude rats were used as control. RESULTS Approximately 6% of the F2 pups (11/172) were homozygous for RCS-p+ gene and Foxn1mu gene. Homozygous males crossed with heterozygous females resulted in 50% homozygous progeny for experimentation. OCT imaging demonstrated significant loss of retinal thickness in homozygous rats. H&E staining showed photoreceptor thickness reduced to 1-3 layers at 12 weeks of age. Progressive loss of visual function was evidenced by OKN testing, ERG, and SC electrophysiology. Transplantation experiments demonstrated survival of human-derived cells and absence of apparent immune rejection. CONCLUSIONS This new rat animal model developed by crossing RCS rats and athymic nude rats is suitable for conducting retinal transplantation experiments involving xenografts.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA.
- USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA.
| | - Danhong Zhu
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Tai-Chi Lin
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Young Chang Kim
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Magdalene J Seiler
- Department of Physical Medicine & Rehabilitation, University of California-Irvine, Irvine, CA, USA
- Stem Cell Research Center, University of California-Irvine, Irvine, CA, USA
| | - Juan Carlos Martinez-Camarillo
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA
| | - Bin Lin
- Department of Physical Medicine & Rehabilitation, University of California-Irvine, Irvine, CA, USA
- Stem Cell Research Center, University of California-Irvine, Irvine, CA, USA
| | - Yousuf Shad
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
| | - David R Hinton
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Mark S Humayun
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, 90033, USA
- USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA
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Kashani AH, Lebkowski JS, Rahhal FM, Avery RL, Salehi-Had H, Dang W, Lin CM, Mitra D, Zhu D, Thomas BB, Hikita ST, Pennington BO, Johnson LV, Clegg DO, Hinton DR, Humayun MS. A bioengineered retinal pigment epithelial monolayer for advanced, dry age-related macular degeneration. Sci Transl Med 2018; 10:10/435/eaao4097. [DOI: 10.1126/scitranslmed.aao4097] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/28/2017] [Accepted: 03/23/2018] [Indexed: 11/02/2022]
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Seiler MJ, Lin RE, McLelland BT, Mathur A, Lin B, Sigman J, De Guzman AT, Kitzes LM, Aramant RB, Thomas BB. Vision Recovery and Connectivity by Fetal Retinal Sheet Transplantation in an Immunodeficient Retinal Degenerate Rat Model. Invest Ophthalmol Vis Sci 2017; 58:614-630. [PMID: 28129425 PMCID: PMC6020716 DOI: 10.1167/iovs.15-19028] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 11/29/2016] [Indexed: 01/28/2023] Open
Abstract
Purpose To characterize a recently developed model, the retinal degenerate immunodeficient S334ter line-3 rat (SD-Foxn1 Tg(S334ter)3Lav) (RD nude rat), and to test whether transplanted rat fetal retinal sheets can elicit lost responses to light. Methods National Institutes of Health nude rats (SD-Foxn1 Tg) with normal retina were compared to RD nude rats with and without transplant for morphology and visual function. Retinal sheets from transgenic rats expressing human placental alkaline phosphatase (hPAP) were transplanted into the subretinal space of RD nude rats between postnatal day (P) 26 and P38. Transplant morphology was examined in vivo using optical coherence tomography (OCT). Visual function was assessed by optokinetic (OKN) testing, electroretinogram (ERG), and superior colliculus (SC) electrophysiology. Cryostat sections were analyzed for various retinal/synaptic markers and for the expression of donor hPAP. Results Optical coherence tomography scans showed the placement and laminar development of retinal sheet transplants in the subretinal space. Optokinetic testing demonstrated a deficit in visual acuity in RD nude rats that was improved after retinal sheet transplantation. No ERG responses were detected in the RD nude rats with or without transplantation. Superior colliculus responses were absent in age-matched control and sham surgery RD nude rats; however, robust light-evoked responses were observed in a specific location in the SC of transplanted RD nude rats. Responsive regions corresponded to the area of transplant placement in the eye. The quality of visual responses correlated with transplant organization and placement. Conclusions The data suggest that retinal sheet transplants integrate into the host retina of RD nude rats and recover significant visual function.
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Affiliation(s)
- Magdalene J. Seiler
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
- Department of Physical Medicine & Rehabilitation, University of California-Irvine, Irvine, California, United States
| | - Robert E. Lin
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Bryce T. McLelland
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Anuradha Mathur
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Bin Lin
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Jaclyn Sigman
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Alexander T. De Guzman
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
- Department of Physical Medicine & Rehabilitation, University of California-Irvine, Irvine, California, United States
| | - Leonard M. Kitzes
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
- Department of Anatomy & Neurobiology, University of California-Irvine, Irvine, California, United States
| | - Robert B. Aramant
- Stem Cell Research Center, University of California-Irvine, Irvine, California, United States
| | - Biju B. Thomas
- USC Roski Eye Institute, Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
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Thomas BB, Zhu D, Zhang L, Thomas PB, Hu Y, Nazari H, Stefanini F, Falabella P, Clegg DO, Hinton DR, Humayun MS. Survival and Functionality of hESC-Derived Retinal Pigment Epithelium Cells Cultured as a Monolayer on Polymer Substrates Transplanted in RCS Rats. ACTA ACUST UNITED AC 2016; 57:2877-87. [DOI: 10.1167/iovs.16-19238] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Biju B. Thomas
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States 2USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, California, United States
| | - Danhong Zhu
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States 3Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - Li Zhang
- Eye Center, Second Affiliated Hospital, Medical School of Zhejiang University, Hangzhou, China
| | - Padmaja B. Thomas
- Cellular Therapies Production Center, City of Hope, Duarte, California, United States
| | - Yuntao Hu
- Department of Ophthalmology, Beijing Tsinghua Changgung Hospital, Tsinghua University Medical Center, Beijing, China
| | - Hossein Nazari
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States
| | - Francisco Stefanini
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States
| | - Paulo Falabella
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States
| | - Dennis O. Clegg
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California, United States
| | - David R. Hinton
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States 3Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - Mark S. Humayun
- Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, United States 2USC Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, California, United States
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Zhang L, Liu L, Philip AL, Martinez JC, Guttierez JC, Marella M, Patki G, Matsuno-Yagi A, Yagi T, Thomas BB. Long-term evaluation of Leber's hereditary optic neuropathy-like symptoms in rotenone administered rats. Neurosci Lett 2014; 585:171-6. [PMID: 25481764 DOI: 10.1016/j.neulet.2014.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/27/2014] [Accepted: 12/01/2014] [Indexed: 12/21/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is an inherited disorder affecting the retinal ganglion cells (RGCs) and their axons that lead to the loss of central vision. This study is aimed at evaluating the LHON symptoms in rats administered with rotenone microspheres into the superior colliculus (SC). Optical coherence tomography (OCT) analysis showed substantial loss of retinal nerve fiber layer (RNFL) thickness in rotenone injected rats. Optokinetic testing in rotenone treated rats showed decrease in head-tracking response. Electrophysiological mapping of the SC surface demonstrated attenuation of visually evoked responses; however, no changes were observed in the ERG data. The progressive pattern of disease manifestation in rotenone administered rats demonstrated several similarities with human disease symptoms. These rats with LHON-like symptoms can serve as a model for future investigators to design and implement reliable tests to assess the beneficial effects of therapeutic interventions for LHON disease.
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Affiliation(s)
- Li Zhang
- Eye Center, Second Affiliated Hospital, Medical School of Zhejiang University, Hangzhou, China; Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA,USA
| | - Laura Liu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Ann L Philip
- Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA,USA
| | - Juan C Martinez
- Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA,USA
| | - Juan C Guttierez
- Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA,USA
| | - Mathieu Marella
- Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA,USA
| | - Gaurav Patki
- Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA,USA
| | - Akemi Matsuno-Yagi
- Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA,USA
| | - Takao Yagi
- Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA,USA
| | - Biju B Thomas
- Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA,USA.
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Ribeiro RM, Oregon A, Diniz B, Fernandes RB, Koss MJ, Charafeddin W, Hu Y, Thomas P, Thomas BB, Maia M, Chader GJ, Hinton DR, Humayun MS. In vivo detection of hESC-RPE cells via confocal near-infrared fundus reflectance. Ophthalmic Surg Lasers Imaging Retina 2014; 44:380-4. [PMID: 23883533 DOI: 10.3928/23258160-20130715-09] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 04/19/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND OBJECTIVE To investigate whether the confocal near-infrared reflectance (NIR) imaging modality could detect the in vivo presence of retinal pigment epithelium cells derived from embryonic human stem cells (hESC-RPE) implanted into the subretinal space of the Royal College of Surgeons (RCS) rat. MATERIALS AND METHODS Monthly NIR images were obtained from RCS rats implanted with either hESC-RPE seeded on a parylene membrane (n = 14) or parylene membrane without cells (n = 14). Two independent, masked investigators graded the images. Histology and immunohistochemistry were performed at different time points (150, 210, and 270 postnatal days of age). RESULTS NIR images revealed that an average of 20.53% of the parylene membrane area was covered by hESC-RPE. RPE-65 and TRA-1-85 confirmed the presence of human-specific RPE cells in those animals. No areas corresponding to cells were found in the group implanted with membrane only. Intergrader agreement was high (r = 0.89-0.92). CONCLUSION The NIR mode was suitable to detect the presence of hESC-RPE seeded on a membrane and implanted into the subretinal space of the RCS rat.
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Affiliation(s)
- Ramiro M Ribeiro
- Doheny Eye Institute, 1355 San Pablo Street, Los Angeles, CA 90033, USA.
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Hu Y, Liu L, Lu B, Zhu D, Ribeiro R, Diniz B, Thomas PB, Ahuja AK, Hinton DR, Tai YC, Hikita ST, Johnson LV, Clegg DO, Thomas BB, Humayun MS. A novel approach for subretinal implantation of ultrathin substrates containing stem cell-derived retinal pigment epithelium monolayer. Ophthalmic Res 2012; 48:186-91. [PMID: 22868580 DOI: 10.1159/000338749] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 03/21/2012] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To evaluate the feasibility of a new technique for the implantation of ultrathin substrates containing stem cell-derived retinal pigment epithelium (RPE) cells into the subretinal space of retina-degenerate Royal College of Surgeon (RCS) rats. METHODS A platform device was used for the implantation of 4-µm-thick parylene substrates containing a monolayer of human embryonic stem cell-derived RPE (hESC-RPE). Normal Copenhagen rats (n = 6) and RCS rats (n = 5) were used for the study. Spectral-domain optical coherence tomography (SD-OCT) scanning and histological examinations were performed to confirm placement location of the implant. hESC-RPE cells attached to the substrate before and after implantation were evaluated using standard cell counting techniques. RESULTS SD-OCT scanning and histological examination revealed that the substrates were precisely placed in the rat's subretinal space. The hESC-RPE cell monolayer that covered the surface of the substrate was found to be intact after implantation. Cell counting data showed that less than 2% of cells were lost from the substrate due to the implantation procedure (preimplantation count 2,792 ± 74.09 cells versus postimplantation count 2,741 ± 62.08 cells). Detailed microscopic examination suggested that the cell loss occurred mostly along the edges of the implant. CONCLUSION With the help of this platform device, it is possible to implant ultrathin substrates containing an RPE monolayer into the rat's subretinal space. This technique can be a useful approach for stem cell-based tissue bioengineering techniques in retinal transplantation research.
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Affiliation(s)
- Yuntao Hu
- Doheny Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
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Marella M, Seo BB, Thomas BB, Matsuno-Yagi A, Yagi T. Successful amelioration of mitochondrial optic neuropathy using the yeast NDI1 gene in a rat animal model. PLoS One 2010; 5:e11472. [PMID: 20628600 PMCID: PMC2900204 DOI: 10.1371/journal.pone.0011472] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 06/15/2010] [Indexed: 01/31/2023] Open
Abstract
Background Leber's hereditary optic neuropathy (LHON) is a maternally inherited disorder with point mutations in mitochondrial DNA which result in loss of vision in young adults. The majority of mutations reported to date are within the genes encoding the subunits of the mitochondrial NADH-quinone oxidoreductase, complex I. Establishment of animal models of LHON should help elucidate mechanism of the disease and could be utilized for possible development of therapeutic strategies. Methodology/Principal Findings We established a rat model which involves injection of rotenone-loaded microspheres into the optic layer of the rat superior colliculus. The animals exhibited the most common features of LHON. Visual loss was observed within 2 weeks of rotenone administration with no apparent effect on retinal ganglion cells. Death of retinal ganglion cells occurred at a later stage. Using our rat model, we investigated the effect of the yeast alternative NADH dehydrogenase, Ndi1. We were able to achieve efficient expression of the Ndi1 protein in the mitochondria of all regions of retinal ganglion cells and axons by delivering the NDI1 gene into the optical layer of the superior colliculus. Remarkably, even after the vision of the rats was severely impaired, treatment of the animals with the NDI1 gene led to a complete restoration of the vision to the normal level. Control groups that received either empty vector or the GFP gene had no effects. Conclusions/Significance The present study reports successful manifestation of LHON-like symptoms in rats and demonstrates the potential of the NDI1 gene therapy on mitochondrial optic neuropathies. Our results indicate a window of opportunity for the gene therapy to be applied successfully after the onset of the disease symptoms.
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Affiliation(s)
- Mathieu Marella
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Byoung Boo Seo
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Biju B. Thomas
- Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Akemi Matsuno-Yagi
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Takao Yagi
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Thomas BB, Shi D, Khine K, Kim LA, Sadda SR. Modulatory influence of stimulus parameters on optokinetic head-tracking response. Neurosci Lett 2010; 479:92-6. [PMID: 20488227 DOI: 10.1016/j.neulet.2010.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 03/17/2010] [Accepted: 05/11/2010] [Indexed: 01/31/2023]
Abstract
Optokinetic testing is a non-invasive technique, widely used for visual functional evaluation in rodents. The modulatory influence of optokinetic stimulus parameters such as contrast level and grating speed on head-tracking response in normal and retinal degenerate (RD) mice (rd10) and rats (S334ter-line-3) was evaluated using a computer-based testing apparatus. In normal (non-RD) mice and rats, specific stripe width and grating speed was found to evoke maximum optokinetic head-tracking response. In line-3 RD rats, the contrast sensitivity loss was slow and remained close to the baseline (normal control) level until very late in the disease, whereas, in rd10 mice the progression of the contrast sensitivity loss was more rapid. Observed differences between rd10 mice and line-3 RD rats in the progression of contrast sensitivity loss may not be directly related to the degree of photoreceptor loss. In young RD mice, the modulatory influence of stimulus parameters on optokinetic head-tracking response was similar to normal control animals. During later stages, slower grating speed was required to evoke the maximum optokinetic response. Grating speed had lesser apparent influence on the response properties of line-3 RD rats. Discrepancies between the two RD models in the modulatory influence of optokinetic stimulus parameters can be the manifestation of fundamental species differences and/or differences in the degeneration pattern. This study highlights the importance of careful selection of appropriate stimulus parameters for testing optokinetic head-tracking response in RD animals.
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Affiliation(s)
- Biju B Thomas
- Doheny Retina Institute, Doheny Eye Institute, 1450 San Pablo St., Los Angeles, CA 90033, United States.
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Seiler MJ, Aramant RB, Thomas BB, Peng Q, Sadda SR, Keirstead HS. Visual restoration and transplant connectivity in degenerate rats implanted with retinal progenitor sheets. Eur J Neurosci 2010; 31:508-20. [PMID: 20105230 PMCID: PMC2875871 DOI: 10.1111/j.1460-9568.2010.07085.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this study was to determine whether retinal progenitor layer transplants form synaptic connections with the host and restore vision. Donor retinal sheets, isolated from embryonic day 19 rat fetuses expressing human placental alkaline phosphatase (hPAP), were transplanted to the subretinal space of 18 S334ter-3 rats with fast retinal degeneration at the age of 0.8-1.3 months. Recipients were killed at the age of 1.6-11.8 months. Frozen sections were analysed by confocal immunohistochemistry for the donor cell label hPAP and synaptic markers. Vibratome slices were stained for hPAP, and processed for electron microscopy. Visual responses were recorded by electrophysiology from the superior colliculus (SC) in 12 rats at the age of 5.3-11.8 months. All recorded transplanted rats had restored or preserved visual responses in the SC corresponding to the transplant location in the retina, with thresholds between -2.8 and -3.4 log cd/m(2). No such responses were found in age-matched S334ter-3 rats without transplants, or in those with sham surgery. Donor cells and processes were identified in the host by light and electron microscopy. Transplant processes penetrated the inner host retina in spite of occasional glial barriers between transplant and host. Labeled neuronal processes were found in the host inner plexiform layer, and formed apparent synapses with unlabeled cells, presumably of host origin. In conclusion, synaptic connections between graft and host cells, together with visual responses from corresponding locations in the brain, support the hypothesis that functional connections develop following transplantation of retinal layers into rodent models of retinal degeneration.
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Affiliation(s)
- M J Seiler
- Reeve-Irvine Research Center, Gillespie Neuroscience Research Facility, School of Medicine, University of California at Irvine, Irvine, CA 92697-4292, USA
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Abstract
PURPOSE To evaluate retinal sheet transplants in S334ter-line-3 retinal degenerate rats by comparing visual responses recorded electrophysiologically with morphology based on light and electron microscopy. METHODS S334ter-line-3 retinal degenerate rats (n = 7) received retinal sheet transplants between postnatal days 28 and 31. The donor tissue was derived from transgenic embryonic day 19 (E19) rat retinae expressing human placental alkaline phosphatase (hPAP). Fresh retinal sheets were gently transplanted into the subretinal space of the left eye with the help of a custom-made implantation tool. Selected rats (n = 5) were subjected to electrophysiologic evaluation of visual responses from the superior colliculus about 84-121 days after surgery. Transplanted eyes were processed for light microscopy (LM) and electron microscopy (EM) evaluations. RESULTS All the transplanted rats that were evaluated for visual responses in the brain showed responses to very low light stimulation (-3.42 to -2.8 log cd/m(2)) of the eye in a small area of the superior colliculus corresponding with the placement of the transplant in the host retina. Histologic evaluation showed that most of the transplants contained well-laminated areas with correct polarity in the subretinal space. Inside the transplant areas, rosettes of photoreceptors with inner and outer segments were found. In the laminated areas, the outer segments of photoreceptors were facing the host retinal pigment epithelium (RPE). Immunohistochemical evaluation of hPAP donor cells revealed areas with specific staining of the transplants in the subretinal space. Electron microscopic evaluation showed a glial demarcation membrane between the host and the transplant, however, processes originating from the transplant were observed inside the host retina. CONCLUSIONS Sheets of E19 rat retina transplanted into the subretinal space of S334ter-line-3 rats survived without immune rejection and continued to show visual function when tested after 3 months. Well-developed photoreceptors and many synapse types were seen within the transplants. hPAP staining showed a certain degree of integration between the host retina and the transplant suggesting that transplanted photoreceptors contributed to the restored light sensitivity.
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Affiliation(s)
- Qing Peng
- Department of Ophthalmology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
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Chan LH, Ray A, Thomas BB, Humayun MS, Weiland JD. In vivo study of response threshold in retinal degenerate model at different degenerate stages. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2008:1781-4. [PMID: 19163026 DOI: 10.1109/iembs.2008.4649523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Retinal prostheses are being developed to apply electrical stimulation to the retina in order to restore vision of individuals who suffer from diseases such as retinitis pigmentosa (RP) and aged related macular degeneration (AMD). Various electrical stimulus parameters have been extensively studied in both experimental and clinical settings. Both electrophysiological and psychophysical results have shown that outer retina disease exhibit higher stimulus threshold in one degenerate group versus the control group. Fewer studies have been conducted to investigate the change in threshold currents as a function of different degenerate stages. We propose to study the electrophysiological change in degenerate rat retinas by using an in vivo recording method. We recorded retinal-driven superior colliculus cells response in two control groups and four degenerate groups. Current pulses of seven different stimulus pulse durations were applied to the retinas to obtain strength duration curve per group. Preliminary results showed that for the postnatal (P) day 90 and 180 degenerate groups, threshold currents were not significantly different from the normal control group (P90 and P230). For P300 degenerate group, the threshold currents progressively increased. For P760 degenerate group, threshold currents were significantly elevated across all the stimulus pulse durations tested. Charge densities calculated for P760 degenerate group exceeded the safe limit of the stimulating electrode. Cell morphology in all control and degenerate groups is still under investigation for a correlation study.
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Affiliation(s)
- L H Chan
- Biomedical Engineering Department, University of Southern California, Los Angeles 90033, USA.
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Seiler MJ, Thomas BB, Chen Z, Wu R, Sadda SR, Aramant RB. Retinal transplants restore visual responses: trans-synaptic tracing from visually responsive sites labels transplant neurons. Eur J Neurosci 2008; 28:208-20. [DOI: 10.1111/j.1460-9568.2008.06279.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Seiler MJ, Thomas BB, Chen Z, Arai S, Chadalavada S, Mahoney MJ, Sadda SR, Aramant RB. BDNF-treated retinal progenitor sheets transplanted to degenerate rats: improved restoration of visual function. Exp Eye Res 2007; 86:92-104. [PMID: 17983616 DOI: 10.1016/j.exer.2007.09.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 08/28/2007] [Accepted: 09/26/2007] [Indexed: 02/07/2023]
Abstract
The aim of this study was to evaluate the functional efficacy of retinal progenitor cell (RPC) containing sheets with BDNF microspheres following subretinal transplantation in a rat model of retinal degeneration. Sheets of E19 RPCs derived from human placental alkaline phosphatase (hPAP) expressing transgenic rats were coated with poly-lactide-co-glycolide (PLGA) microspheres containing brain-derived neurotrophic factor (BDNF) and transplanted into the subretinal space of S334ter line 3 rhodopsin retinal degenerate rats. Controls received transplants without BDNF or BDNF microspheres alone. Visual function was monitored using optokinetic head-tracking behavior. Visually evoked responses to varying light intensities were recorded from the superior colliculus (SC) by electrophysiology at 60days after surgery. Frozen sections were studied by immunohistochemistry for photoreceptor and synaptic markers. Visual head tracking was significantly improved in rats that received BDNF-coated RPC sheets. Relatively more BDNF-treated transplanted rats (80%) compared to non-BDNF transplants (57%) responded to a "low light" intensity of 1cd/m2 in a confined SC area. With bright light, the onset latency of SC responses was restored to a nearly normal level in BDNF-treated transplants. No significant improvement was observed in the BDNF-only and no surgery transgenic control rats. The bipolar synaptic markers mGluR6 and PSD-95 showed normal distribution in transplants and abnormal distribution of the host retina, both with or without BDNF treatment. Red-green cones were significantly reduced in the host retina overlying the transplant in the BDNF-treated group. In summary, BDNF coating improved the functional efficacy of RPC grafts. The mechanism of the BDNF effects--either promoting functional integration between the transplant and the host retina and/or synergistic action with other putative humoral factors released by the RPCs--still needs to be elucidated.
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Thomas BB, Seiler MJ, Aramant RB, Samant D, Qiu G, Vyas N, Arai S, Chen Z, Sadda SR. Visual functional effects of constant blue light in a retinal degenerate rat model. Photochem Photobiol 2007; 83:759-65. [PMID: 17115798 DOI: 10.1562/2006-09-19-ra-1044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Retinal degenerative conditions increase susceptibility to light damage, but rapid retinal degeneration (RD) models show less susceptibility to cyclic dim light. We investigated whether constant blue light (BL) exposure can eliminate the residual visual responses in a comparatively rapid RD rat model. Pigmented rhodopsin mutant S334ter line-3 rat pups (21 days old) were exposed for 5-6 consecutive days to constant BL. Visual behavior was evaluated with an optokinetic head tracking apparatus. Electrophysiological recordings were made from the superior colliculus (SC). S-antigen, red-green opsin and rhodopsin immunoreactive residual photoreceptors were counted. Following BL exposure, head tracking was significantly reduced at 0.25 cycles degree(-1) in 38-day-old line 3 rats. With a 0.125 cycles degree(-1) stimulus, the head tracking performance of 80-day-old BL rats were similar to that of 220-day-old no-BL-treated line-3 rats. SC recordings also revealed a significant decrease in the residual photoreceptor activity. Histological evaluation showed reduction of the rod population in the central area of the light-damaged retina. Exposure to constant BL considerably reduces the residual visual responses in a rapid degenerating RD rat model.
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Affiliation(s)
- Biju B Thomas
- Doheny Retina Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
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Qiu G, Seiler MJ, Thomas BB, Wu K, Radosevich M, Sadda SR. Revisiting nestin expression in retinal progenitor cells in vitro and after transplantation in vivo. Exp Eye Res 2007; 84:1047-59. [PMID: 17451684 DOI: 10.1016/j.exer.2007.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Revised: 01/13/2007] [Accepted: 01/16/2007] [Indexed: 10/23/2022]
Abstract
The purpose of this study is to characterize the co-expression of nestin--a neuroectodermal stem cell and a reactive glial marker-with various mature retinal cell markers in retinal progenitor cells (RPCs) expanded in vitro, followed either by in vitro induction or subretinal transplantation. Rat RPCs derived from embryonic day (E) 17 rat retina were expanded in serum free defined culture, and induced to differentiate by all-trans retinoic acid (RA). Following induction, cells were stained for nestin in combination with retinal neuronal and glial markers. Cultured cells were collected for quantitative RT-PCR gene expression analysis prior to and after induction. In a second series, passage 2 RPCs were transplanted into the subretinal space of S334ter-3 retinal degeneration rats at postnatal day 28. After 1-4 weeks, sections through the transplant were double immunostained for nestin and various retinal specific neuronal markers. The cultured RPCs treated with RA exhibited nestin co-expression with various retinal specific markers, including protein kinase C alpha (PKC), neurofilament 200 (NF200), cellular retinaldehyde binding protein (CRALBP), and rhodopsin. Following RA induction, quantitative RT-PCR analysis demonstrated downregulation of nestin, PAX-6, thy1.1, and PKCalpha, and upregulation of rhodopsin, glial fibrillary acidic protein (GFAP), and CrX. No nestin coexpression was observed with any of the retinal specific neuronal markers in RPC transplants in vivo except for some nestin-immunoreactivity overlapping with GFAP positive cells in the host retina. The role of nestin as a unique neural stem/progenitor cell marker should be reconsidered. Nestin expression during RPC maturation appears to be different in vitro versus in vivo.
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Affiliation(s)
- Guanting Qiu
- Department of Ophthalmology, Doheny Retina Institute, Keck School of Medicine, at the University of Southern California, 1450 Pablo St - DEI 3610, Los Angeles, CA, 90033-3699, USA
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Thomas BB, Samant DM, Seiler MJ, Aramant RB, Sheikholeslami S, Zhang K, Chen Z, Sadda SR. Behavioral evaluation of visual function of rats using a visual discrimination apparatus. J Neurosci Methods 2007; 162:84-90. [PMID: 17289151 PMCID: PMC3074943 DOI: 10.1016/j.jneumeth.2006.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 12/13/2006] [Accepted: 12/14/2006] [Indexed: 09/30/2022]
Abstract
A visual discrimination apparatus was developed to evaluate the visual sensitivity of normal pigmented rats (n=13) and S334ter-line-3 retinal degenerate (RD) rats (n=15). The apparatus is a modified Y maze consisting of two chambers leading to the rats' home cage. Rats were trained to find a one-way exit door leading into their home cage, based on distinguishing between two different visual alternatives (either a dark background or black and white stripes at varying luminance levels) which were randomly displayed on the back of each chamber. Within 2 weeks of training, all rats were able to distinguish between these two visual patterns. The discrimination threshold of normal pigmented rats was a luminance level of -5.37+/-0.05 log cd/m(2); whereas the threshold level of 100-day-old RD rats was -1.14+/-0.09 log cd/m(2) with considerable variability in performance. When tested at a later age (about 150 days), the threshold level of RD rats was significantly increased (-0.82+/-0.09 log cd/m(2), p<0.03, paired t-test). This apparatus could be useful to train rats at a very early age to distinguish between two different visual stimuli and may be effective for visual functional evaluations following therapeutic interventions.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Thomas BB, Aramant RB, Sadda SR, Seiler MJ. Retinal transplantation. A treatment strategy for retinal degenerative diseases. Adv Exp Med Biol 2006; 572:367-76. [PMID: 17249598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Retinal transplantation is one among the various treatment strategies aimed to prevent and restore visual loss. Sheets of fetal retina with or without retinal pigment epithelium (RPE) are transplanted into the subretinal space. Retinal transplants have been shown to substantially improve visual responses in rat retinal degeneration models following retinal transplantation, based on behavior and electrophysiology. The transplantation effects may be influenced by several factors such as the age of the recipient at transplantation and the type of species used. Modified functional evaluation techniques permit better understanding of the physiological mechanisms underlying visual improvement in animal models.
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Affiliation(s)
- Biju B Thomas
- Dept. Ophthalmology, Doheny Retina Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Thomas BB, Aramant RB, Sadda SR, Seiler MJ. Light response differences in the superior colliculus of albino and pigmented rats. Neurosci Lett 2005; 385:143-7. [PMID: 15950381 DOI: 10.1016/j.neulet.2005.05.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2005] [Revised: 05/12/2005] [Accepted: 05/14/2005] [Indexed: 11/23/2022]
Abstract
Multi-unit visual responses to light intensities ranging from -6.46 to 0.81 logcd/m2 were recorded from the surface of the superior colliculus of dark-adapted normal pigmented and normal albino rats. Light sensitivity was significantly higher in albinos. The response onset latency was inversely proportional to the stimulus intensity. The progression of the stimulus intensity versus response onset latency curve showed a considerable difference between pigmented and albino rats. At low light levels, longer response onset latencies were recorded in pigmented rats than in albinos. This can be attributed to the transmission of rod-driven responses. The differences observed in the light response characteristics of albino rats may be indicative of their visual abnormalities.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Retina Institute, Doheny Eye Institute, Keck School of Medicine, University of Southern California, DVRC 402, 1355 San Pablo St., Los Angeles, CA 90033, USA
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Thomas BB, Arai S, Ikai Y, Qiu G, Chen Z, Aramant RB, Sadda SR, Seiler MJ. Retinal transplants evaluated by optical coherence tomography in photoreceptor degenerate rats. J Neurosci Methods 2005; 151:186-93. [PMID: 16129495 DOI: 10.1016/j.jneumeth.2005.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 06/17/2005] [Accepted: 07/13/2005] [Indexed: 11/28/2022]
Abstract
Optical coherence tomography (OCT), a non-invasive method, was used for qualitative assessment of fetal retinal sheet transplants by non-invasive imaging. Rhodopsin-mutant S334ter-line-3 rats with fast retinal degeneration (28-37-day old) were transplanted with fetal retinal sheets from embryonic day (E) 18-19 pigmented normal rats. Retinal thickness measurements from transplanted (n = 51), no surgery control (n = 8), and normal pigmented rat eyes (n = 6) were obtained using a Zeiss stratus OCT-3 scanning instrument. Frozen retinal sections were stained with hematoxylin/eosin. S334ter-line-3 rats showed significant reduction in OCT retinal thickness (p<0.001) compared to normal pigmented rats at the age of 21 days. In 62% of the transplanted rats, OCT scanning revealed the presence of a subretinal graft, which was confirmed by subsequent histology. Retinal thickness in the transplant area was significantly increased compared to the area outside the transplant and to non-transplanted eyes (p<0.001). While most of the transplants with single-band OCT images (87%) had rosetted transplants, a considerable proportion of transplants having a multi-band OCT image were found to have well-laminated areas in the graft after histological evaluation. Following retinal transplantation in rodents, OCT imaging data correlated mostly with transplant morphology. OCT is a useful technique for in vivo screening and evaluation of retinal transplants. This technique determines surgical outcomes at a much earlier stage.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Retina Institute, Keck School of Medicine, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033, USA
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Abstract
The aim of this study was to establish synapses between a transplant and a degenerated retina. To tackle this difficult task, a little-known but well-established CNS method was chosen: trans-synaptic pseudorabies virus (PRV) tracing. Sheets of E19 rat retina with or without retinal pigment epithelium (RPE) were transplanted to the subretinal space in 33 Royal College of Surgeons (RCS) and transgenic s334ter-5 rats with retinal degeneration. Several months later, PRV-BaBlu (expressing E. colibeta-galactosidase) or PRV-Bartha was injected into an area of the exposed superior colliculus (SC), topographically corresponding to the transplant placement in the retina. Twenty normal rats served as controls. After survival times of 1-5 days, retinas were examined for virus by X-gal histochemistry, immunohistochemistry and electron microscopy. In normal controls, virus was first seen in retinal ganglion cells and Müller glia after 1-1.5 days, and had spread to all retinal layers after 2-3 days. Virus-labeled cells were found in 16 of 19 transplants where the virus injection had retrogradely labeled the topographically correct transplant area of the host retina. Electron microscopically, enveloped and nonenveloped virus could clearly be detected in infected cells. Enveloped virus was found only in neurons. Infected glial cells contained only nonenveloped virus. Neurons in retinal transplants are labeled after PRV injection into the host brain, indicating synaptic connectivity between transplants and degenerated host retinas. This study provides evidence that PRV spreads in the retina as in other parts of the CNS and is useful to outline transplant-host circuitry.
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Affiliation(s)
- Magdalene J Seiler
- Department of Ophthalmology & Visual Sciences, University of Louisville, Louisville, KY, USA.
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Arai S, Thomas BB, Seiler MJ, Aramant RB, Qiu G, Mui C, de Juan E, Sadda SR. Restoration of visual responses following transplantation of intact retinal sheets in rd mice. Exp Eye Res 2004; 79:331-41. [PMID: 15336495 DOI: 10.1016/j.exer.2004.05.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Accepted: 05/13/2004] [Indexed: 11/17/2022]
Abstract
PURPOSE To correlate the functional outcomes with histologic findings following transplantation of fetal retinal sheets in rd mice, and to investigate the mechanisms of visual function restoration. METHODS Twenty-one postnatal day 31-38 rd/rd (C3H/HeJ) mice were transplanted in one eye with retinal sheets (1.0 x 0.4 mm) obtained from embryonic day (E) 17 enhanced-green-fluorescent protein (eGFP) mice. Five mice underwent sham surgery without insertion of tissue. Four to five weeks after transplantation, visual responses to a light flash were recorded across the superior colliculus (SC) in seven eyes of seven transplanted mice that had clear corneas and lenses, and in all five sham surgery mice. Following the SC recording, the eyes were enucleated and processed for immunohistochemistry and examined using confocal microscopy. RESULTS In three out of the seven eyes (43%), positive responses were recorded in the SC in an area topographically corresponding to the placement of the transplant in the host retina. No responses were recorded in the untreated eyes of 5-week-old and 9-week-old rd/rd mice, and in the 9-week-old sham surgery mice. In contrast, visual responses were recorded over the entire SC in normal eyes. The response onset latencies of the 3 transplanted mice with responses were similar to those of normal control mice. The organization of the graft did not appear to correlate as expected with the electrophysiology results, as eyes with well-organized, laminated grafts showed no response whereas the three light-responsive eyes had rosetted or disorganized grafts. All three light-responsive eyes demonstrated much higher levels of recoverin immunoreactivity in the host retina overlying the graft compared with untreated age-matched rd/rd mice. CONCLUSION Restoration of the SC visual response does not appear to depend on a well-organized transplant in the rd mouse. Increased recoverin-staining in the host retina in light-responsive animals suggested that host cone rescue was the likely mechanism of vision restoration in this transplant model.
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Affiliation(s)
- S Arai
- Doheny Retina Institute, Keck School of Medicine, University of Southern California, DEI 3610, 1450 San Pablo Street, Los Angeles 90033-3699, USA
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Thomas BB, Seiler MJ, Sadda SR, Coffey PJ, Aramant RB. Optokinetic test to evaluate visual acuity of each eye independently. J Neurosci Methods 2004; 138:7-13. [PMID: 15325106 DOI: 10.1016/j.jneumeth.2004.03.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 02/28/2004] [Accepted: 03/04/2004] [Indexed: 10/26/2022]
Abstract
A previously described optokinetic testing apparatus [Nat. Neurosci. 5 (2002) 53] was modified to measure vision in each eye separately for evaluation of monocular treatments. This apparatus consists also of a striped rotating drum. Ca. 170 degrees of the drum are illuminated from outside and ca. 190 degrees of the drum move behind a stationary black wall. The rat sits unrestrained in the drum center in a tube so that one eye is unexposed to the rotating stripes. Normal pigmented and retinal degenerate transgenic S334ter-3 rats were tested with the original and the modified apparatus. The usefulness of this method was tested in retinal degenerate rats with retinal transplants in one eye. In retinal degenerate animals, the amount of time (seconds) spent for head-tracking tended to be higher with the original method, possibly due to simultaneous stimulation of both eyes. In rats with retinal transplants, visual responses were significantly preserved in transplanted eyes at late stages of retinal degeneration. In conclusion, contributions from the fellow eye to the optokinetic tracking response can be limited by this testing modification, which is useful for evaluation of treatment effects to one eye.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Retina Institute/DVRC 402, Keck School of Medicine at the University of Southern California, 1355 San Pablo St., Los Angeles, CA 90033, USA
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Thomas BB, Seiler MJ, Sadda SR, Aramant RB. Superior colliculus responses to light – preserved by transplantation in a slow degeneration rat model. Exp Eye Res 2004; 79:29-39. [PMID: 15183098 DOI: 10.1016/j.exer.2004.02.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Accepted: 02/24/2004] [Indexed: 12/01/2022]
Abstract
PURPOSE To determine whether retinal transplantation can preserve visual responses in the superior colliculus (SC) of the S334ter-line-5 rat, a transgenic model for slow photoreceptor degeneration, which is more similar to human retinitis pigmentosa than the fast degeneration line 3 S334ter rat. METHODS Visual responses to a light flash were recorded in the SC. Rats that had received embryonic day (E) 19-20 fetal retinal sheet transplants at the age of 26-30 days were tested at the ages of 200-254 days. Controls were age-matched rats without surgery and with sham surgery. As a baseline, in no-surgery line-5 rats, the temporal pattern of visual sensitivity loss was evaluated electrophysiologically in the SC from 60 days up to one year of age. RESULTS In untreated S334ter-line-5 rats, decline in visual sensitivity in the SC was parallel to the photoreceptor loss. At 109 day of age, a relative scotoma developed in the area of the SC corresponding to the nasal retinal region. At 200-254 days of age, the majority of the SC was devoid of any light-driven responses. In contrast, at this time point, transplanted rats with 'good' retinal grafts with normal lamination had visual responses in the caudal region of the SC, the area corresponding topographically to the transplant location in the retina. In these rats, the various parameters of SC responses such as the latency of the onset of the visual response, the response peak amplitude and the consistency of the visual response were significantly different from the control groups (no-surgery, sham surgery, 'poor' transplants) and were more comparable to normal albino rats, however, with a slightly longer latency (70-90 vs. 30-50 msec). CONCLUSIONS Fetal retinal sheet transplantation showed a long-term rescue effect on visual function in this animal model of slow photoreceptor degeneration.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Eye Institute, University of Southern California, 1450 San Pablo St, Los Angeles, CA 90033, USA
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Abstract
The effects of exposure to constant light (CL) and blinding on male reproductive behavioral physiology of South Indian gerbils (Tatera indica cuvieri) were assessed. Exposure to CL diminished reproductive efficiency of males with a reduction in the proportion of ejaculating males. This is further evidenced by increase in the number and duration of intromissions and intromission latency. Concomitantly, reproductive organ weight and epididymal sperm count were also reduced. However, in weanlings CL did not induce changes either in their maturational process or their reproductive organs' weight. Blinding of adult reproductively inactive males resulted in a considerable proportion of them exhibiting sexual activity, which is reflected in the seminal vesicle weight and epididymal sperm count. Blinded weanlings showed earlier testicular descent and higher seminal vesicle weight. These studies reveal that blinding (constant darkness) has a stimulatory effect whereas CL is inhibitory in the reproduction of the tropical rodent Tatera indica cuvieri. J. Exp. Zool. 289:59-65, 2001.
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Affiliation(s)
- B B Thomas
- Department of Zoology, University of Kerala, Kariavattom P.O-695 581, Trivandrum, Kerala State, India 0471-418906, 555494
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Thomas BB, Oommen MM. Effect of photic changes and olfactory impairment on reproduction in female south Indian gerbil. Indian J Exp Biol 1999; 37:1201-4. [PMID: 10865888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Effect of exposure to constant light (CL), blinding and olfactory bulbectomy (OBX) on reproduction of adult and weanling female Tatera indica cuvieri was investigated. In adult females, CL induced changes in estrus cyclicity. Weanlings subjected to CL showed reduced ovarian weight. Blinding did not bring about changes in estrus cyclicity and reproductive organ weight (ovary and uterus) of either adults or weanlings. Estrus cyclicity of both adults and weanlings were affected consequent to OBX. In weanlings, OBX lowered the ovarian and uterine weight.
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Affiliation(s)
- B B Thomas
- Department of Zoology, University of Kerala, Kariavattom, Trivandrum, India
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Thomas BB, Oommen MM. Olfactory bulbectomy-induced changes in the reproductive behaviour of the south Indian gerbil, Tatera indica cuvieri. Indian J Exp Biol 1999; 37:296-9. [PMID: 10641161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Male South Indian gerbils (T. indica cuvieri), both adults and weanlings, were olfactory bulbectomized (OBX) and changes in male reproductive behaviour were assessed. Consequent to OBX, majority of the adult males failed to ejaculate, and courtship behaviour has also been considerably reduced. All OBX weanlings were rendered incapable of ejaculation. However, maturational parameters, and organ weights (testes, epididymis and seminal vesicle) remained unchanged in OBX males.
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Affiliation(s)
- B B Thomas
- Department of Zoology, University of Kerala, Kariavattom, Trivandrum, India
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Thomas BB, Oommen MM. Reproductive behaviour of the South Indian gerbil Tatera indica cuvieri with a note on the role of postejaculatory copulations. ACTA ACUST UNITED AC 1998. [DOI: 10.4098/at.arch.98-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Waugh R, McLean K, Flavell AJ, Pearce SR, Kumar A, Thomas BB, Powell W. Genetic distribution of Bare-1-like retrotransposable elements in the barley genome revealed by sequence-specific amplification polymorphisms (S-SAP). Mol Gen Genet 1997; 253:687-94. [PMID: 9079879 DOI: 10.1007/s004380050372] [Citation(s) in RCA: 349] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Retrotransposons are present in high copy number in many plant genomes. They show a considerable degree of sequence heterogeneity and insertional polymorphism, both within and between species. We describe here a polymerase chain reaction (PCR)-based method which exploits this polymorphism for the generation of molecular markers in barley. The method produces amplified fragments containing a Bare-1-like retrotransposon long terminal repeat (LTR) sequence at one end and a flanking host restriction site at the other. The level of polymorphism is higher than that revealed by amplified fragment length polymorphism (AFLP) in barley. Segregation data for 55 fragments, which were polymorphic in a doubled haploid barley population, were analysed alongside an existing framework of some 400 other markers. The markers showed a widespread distribution over the seven linkage groups, which is consistent with the distribution of the Bare-1 class of retrotransposons in the barley genome based on in situ hybridisation data. The potential applicability of this method to the mapping of other multicopy sequences in plants is discussed.
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Affiliation(s)
- R Waugh
- Department of Cell and Molecular Genetics, Scottish Crop Research Institute, Invergowrie, Dundee, UK
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Thomas BB, McAdam J, Bell B, Wodak J. Learning to live with death and grieving. UNA Nurs J 1971; 69:9-17. [PMID: 5208054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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