Integrin CD11b Deficiency Aggravates Retinal Microglial Activation and RGCs Degeneration After Acute Optic Nerve Injury.

Abstract

Neuroinflammation plays a vital role in the process of a variety of retinal ganglion cells (RGCs) degenerative diseases including traumatic optic neuropathy (TON). Retinal microglial activation is believed as a harbinger of TON, and robust microglial activation can aggravate trauma-induced RGCs degeneration, which ultimately leads to RGCs loss. Toll like receptor 4 (TLR4)-triggered inflammation is of great importance in retinal inflammatory response after optic nerve injury. CD11b on macrophage and brain microglia can inhibit TLR4-triggered inflammation. However, the functional role of CD11b in retinal microglia is not well understood. Here, using an optic nerve crush model and CD11b gene deficient mice, we found that CD11b protein expression was mainly on retinal microglia, significantly increased after optic nerve injury, and still maintained at a high level till at least 28 days post crush. Compared with wild type mice, following acute optic nerve injury, CD11b deficient retinae exhibited more exacerbated microglial activation, accelerated RGCs degeneration, less growth associated protein-43 expression, as well as more proinflammatory cytokines such as interleukin-6 and tumor necrosis factor α while less anti-inflammatory factors such as arginase-1 and interleukin-10 production. We conclude that CD11b is essential in regulating retinal microglial activation and neuroinflammatory responses after acute optic nerve injury, which is critical for subsequent RGCs degeneration and loss.

• Authors: Xiao-Feng Cai, Sen Lin, Zhao Geng, Lin-Lin Luo, Yun-Jia Liu, Zhou Zhang, Wen-Yi Liu, Xi Chen, Xue Li, Jun Yan, Jian Ye
• Journal: Neurochemical research (Neurochem Res) Vol. 45 Issue 5 Pg. 1072-1085 (May 2020) ISSN: 1573-6903 [Electronic] United States
• PMID: 32052258 (Publication Type: Journal Article)

Chemical References

• CD11b Antigen
• Integrins

Topics

• Animals
• CD11b Antigen (deficiency)
• Integrins (deficiency)
• Male
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Microglia (metabolism, pathology)
• Optic Nerve Injuries (metabolism, pathology)
• Organ Culture Techniques
• Retinal Degeneration (metabolism, pathology)
• Retinal Ganglion Cells (metabolism, pathology)