| First Author | Glass J | Year | 2023 |
| Journal | Invest Ophthalmol Vis Sci | Volume | 64 |
| Issue | 15 | Pages | 1 |
| PubMed ID | 38038619 | Mgi Jnum | J:343463 |
| Mgi Id | MGI:7564763 | Doi | 10.1167/iovs.64.15.1 |
| Citation | Glass J, et al. (2023) Diabetic Muller-Glial-Cell-Specific Il6ra Knockout Mice Exhibit Accelerated Retinal Functional Decline and Thinning of the Inner Nuclear Layer. Invest Ophthalmol Vis Sci 64(15):1 |
| abstractText | PURPOSE: Interleukin-6 (IL-6) is implicated in the pathology of diabetic retinopathy (DR). IL-6 trans-signaling via soluble IL-6 receptor (IL-6R) is primarily responsible for its pro-inflammatory functions, whereas cis-signaling via membrane-bound IL-6R is anti-inflammatory. Using a Muller-glial-cell-specific Il6ra-/- mouse, we examined how loss of IL-6 cis-signaling in Muller glial cells (MGCs) affected retinal thinning and electroretinography (ERG) response over 9 months of diabetes. METHODS: Diabetes was induced in wildtype and knockout mice with streptozotocin (40 mg/kg, daily for 5 days). Spectral domain optical coherence tomography (SD-OCT), ERG, and fundoscopy/fluorescein angiography (FA) were assessed at 2, 6, and 9 months of diabetes. MGCs and bipolar neurons were examined in retinal tissue sections by immunofluorescence. RESULTS: Diabetic MGC Il6ra-/- mice had significantly thinner retinas than diabetic wildtype mice at 2 (-7.6 microm), 6 (-12.0 microm), and 9 months (-5.0 microm) of diabetes, as well as significant thinning of the inner nuclear layer (INL). Diabetic MGC Il6ra-/- mice also showed a reduction in scotopic B-wave amplitude and B-wave/A-wave ratio earlier than wildtype diabetic mice. In retinal sections, we found a decrease in bipolar neuronal marker PKCalpha only in diabetic MGC Il6ra-/- mice, which was significantly lower than both controls and diabetic wildtype mice. Glutamine synthetase, a Muller cell marker, was reduced in both wildtype and MGC Il6ra-/- diabetic mice compared to their respective controls. CONCLUSIONS: IL-6 cis-signaling in MGCs contributes to maintenance of the INL in diabetes, and loss of the IL-6 receptor reduces MGC-mediated neuroprotection of bipolar neurons in the diabetic retina. |
