1
|
Reynisson H, Kalloniatis M, Fletcher EL, Shivdasani MN, Nivison-Smith L. Loss of Müller cell glutamine synthetase immunoreactivity is associated with neuronal changes in late-stage retinal degeneration. Front Neuroanat 2023; 17:997722. [PMID: 36960036 PMCID: PMC10029270 DOI: 10.3389/fnana.2023.997722] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 07/19/2022] [Accepted: 01/31/2023] [Indexed: 03/09/2023] Open
Abstract
Introduction A hallmark of photoreceptor degenerations is progressive, aberrant remodeling of the surviving retinal neurons and glia following photoreceptor loss. The exact relationship between neurons and glia remodeling in this late stage of retinal degeneration, however, is unclear. This study assessed this by examining Müller cell dysfunction via glutamine synthetase immunoreactivity and its spatial association with retinal neuron subpopulations through various cell markers. Methods Aged Rd1 mice retinae (P150 - P536, n = minimum 5 per age) and control heterozygous rd1 mice retinae (P536, n = 5) were isolated, fixed and cryosectioned. Fluorescent immunolabeling of glutamine synthetase was performed and retinal areas quantified as having low glutamine synthetase immunoreactivity if proportion of labeled pixels in an area was less than two standard deviations of the mean of the total retina. Other Müller cell markers such as Sox9 and Glial fibrillary acidic protein along with neuronal cell markers Calbindin, Calretinin, recoverin, Protein kinase C-α, Glutamic acid decarboxylase 67, and Islet-1 were then quantified within areas of low and normal synthetase immunoreactivity. Results Glutamine synthetase immunoreactivity was lost as a function of age in the rd1 mouse retina (P150 - P536). Immunoreactivity of other Müller cell markers, however, were unaffected suggesting Müller cells were still present in these low glutamine synthetase immunoreactive regions. Glutamine synthetase immunoreactivity loss affected specific neuronal populations: Type 2, Type 8 cone, and rod bipolar cells, as well as AII amacrine cells based on reduced recoverin, protein kinase Ca and parvalbumin immunoreactivity, respectively. The number of cell nuclei within regions of low glutamine synthetase immunoreactivity was also reduced suggesting possible neuronal loss rather than reduced cell marker immunoreactivity. Conclusion These findings further support a strong interplay between glia-neuronal alterations in late-stage degeneration and highlight a need for future studies and consideration in intervention development.
Collapse
Affiliation(s)
- Hallur Reynisson
- School of Optometry and Vision Science, UNSW Sydney, Sydney, NSW, Australia
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, NSW, Australia
| | - Michael Kalloniatis
- School of Optometry and Vision Science, UNSW Sydney, Sydney, NSW, Australia
- Faculty of Medicine (Optometry), Deakin University, Waurn Ponds, VIC, Australia
| | - Erica L. Fletcher
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Mohit N. Shivdasani
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, NSW, Australia
- Bionics and Bio-robotics, Tyree Foundation Institute of Health Engineering, Kensington, NSW, Australia
| | - Lisa Nivison-Smith
- School of Optometry and Vision Science, UNSW Sydney, Sydney, NSW, Australia
- *Correspondence: Lisa Nivison-Smith,
| |
Collapse
|
2
|
Mishra A, Mohan KV, Nagarajan P, Iyer S, Kesarwani A, Nath M, Moksha L, Bhattacharjee J, Das B, Jain K, Sahu P, Sinha P, Velapandian T, Upadhyay P. Peripheral blood-derived monocytes show neuronal properties and integration in immune-deficient rd1 mouse model upon phenotypic differentiation and induction with retinal growth factors. Stem Cell Res Ther 2020; 11:412. [PMID: 32967734 PMCID: PMC7510317 DOI: 10.1186/s13287-020-01925-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 06/11/2020] [Revised: 08/17/2020] [Accepted: 09/04/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cell therapy is one of the most promising therapeutic interventions for retinitis pigmentosa. In the current study, we aimed to assess if peripheral blood-derived monocytes which are highly abundant and accessible could be utilized as a potential candidate for phenotypic differentiation into neuron-like cells. METHODS The peripheral blood-derived monocytes were reconditioned phenotypically using extrinsic growth factors to induce pluripotency and proliferation. The reconditioned monocytes (RM) were further incubated with a cocktail of growth factors involved in retinal development and growth to induce retinal neuron-like properties. These cells, termed as retinal neuron-like cells (RNLCs) were characterized for their morphological, molecular and functional behaviour in vitro and in vivo. RESULTS The monocytes de-differentiated in vitro and acquired pluripotency with the expression of prominent stem cell markers. Treatment of RM with retinal growth factors led to an upregulation of neuronal and retinal lineage markers and downregulation of myeloid markers. These cells show morphological alterations resembling retinal neuron-like cells and expressed photoreceptor (PR) markers. The induced RNLCs also exhibited relative membrane potential change upon light exposure suggesting that they have gained some neuronal characteristics. Further studies showed that RNLCs could also integrate in an immune-deficient retinitis pigmentosa mouse model NOD.SCID-rd1 upon sub-retinal transplantation. The RNLCs engrafted in the inner nuclear layer (INL) and ganglion cell layer (GCL) of the RP afflicted retina. Mice transplanted with RNLCs showed improvement in depth perception, exploratory behaviour and the optokinetic response. CONCLUSIONS This proof-of-concept study demonstrates that reconditioned monocytes can be induced to acquire retinal neuron-like properties through differentiation using a defined growth media and can be a potential candidate for cell therapy-based interventions and disease modelling for ocular diseases.
Collapse
Affiliation(s)
- Alaknanda Mishra
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - K Varsha Mohan
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Perumal Nagarajan
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Srikanth Iyer
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ashwani Kesarwani
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Madhu Nath
- Department of Ocular Pharmacology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Laxmi Moksha
- Department of Ocular Pharmacology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, 110029, India
| | | | - Barun Das
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kshama Jain
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Parul Sahu
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Prakriti Sinha
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - T Velapandian
- Department of Ocular Pharmacology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Pramod Upadhyay
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
3
|
van Wyk M, Hulliger EC, Girod L, Ebneter A, Kleinlogel S. Present Molecular Limitations of ON-Bipolar Cell Targeted Gene Therapy. Front Neurosci 2017; 11:161. [PMID: 28424574 PMCID: PMC5372788 DOI: 10.3389/fnins.2017.00161] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 01/31/2017] [Accepted: 03/13/2017] [Indexed: 11/13/2022] Open
Abstract
Recent studies have demonstrated the safety and efficacy of ocular gene therapy based on adeno-associated viral vectors (AAVs). Accordingly, a surge in promising new gene therapies is entering clinical trials, including the first optogenetic therapy for vision restoration. To date, optogenetic therapies for vision restoration target either the retinal ganglion cells (GCs) or presynaptic ON-bipolar cells (OBCs). Initiating light responses at the level of the OBCs has significant advantages over optogenetic activation of GCs. For example, important neural circuitries in the inner retina, which shape the receptive fields of GCs, remain intact when activating the OBCs. Current drawbacks of AAV-mediated gene therapies targeting OBCs include (1) a low transduction efficiency, (2) off-target expression in unwanted cell populations, and (3) a poor performance in human tissue compared to the murine retina. Here, we examined side-by-side the performance of three state-of-the art AAV capsid variants, AAV7m8, AAVBP2, and AAV7m8(Y444F) in combination with the 4xGRM6-SV40 promoter construct in the healthy and degenerated mouse retina and in human post-mortem retinal explants. We find that (1) the 4xGRM6-SV40 promoter is not OBC specific, (2) that all AAV variants possess broad cellular transduction patterns, with differences between the transduction patterns of capsid variants AAVBP2 and AAV7m8 and, most importantly, (3) that all vectors target OBCs in healthy tissue but not in the degenerated rd1 mouse model, potentially limiting the possibilities for an OBC-targeted optogenetic therapy for vision restoration in the blind.
Collapse
Affiliation(s)
- Michiel van Wyk
- Institute of Physiology, University of BernBern, Switzerland
| | | | - Lara Girod
- Institute of Physiology, University of BernBern, Switzerland
| | - Andreas Ebneter
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of BernBern, Switzerland
| | | |
Collapse
|