670 nm light mitigates oxygen-induced degeneration in C57BL/6J mouse retina

Abstract

BackgroundIrradiation with light wavelengths from the far red (FR) to the near infrared (NIR) spectrum (600 nm -1000 nm) has been shown to have beneficial effects in several disease models. In this study, we aim to examine whether 670 nm red light pretreatment can provide protection against hyperoxia-induced damage in the C57BL/6J mouse retina. Adult mice (90–110 days) were pretreated with 9 J/cm2 of 670 nm light once daily for 5 consecutive days prior to being placed in hyperoxic environment (75% oxygen). Control groups were exposed to hyperoxia, but received no 670 nm light pretreatment. Retinas were collected after 0, 3, 7, 10 or 14 days of hyperoxia exposure (n = 12/group) and prepared either for histological analysis, or RNA extraction and quantitative polymerase chain reaction (qPCR). Photoreceptor damage and loss were quantified by counting photoreceptors undergoing cell death and measuring photoreceptor layer thickness. Localization of acrolein, and cytochrome c oxidase subunit Va (Cox Va) were identified through immunohistochemistry. Expression of heme oxygenase-1 (Hmox-1), complement component 3 (C3) and fibroblast growth factor 2 (Fgf-2) genes were quantified using qPCR.ResultsThe hyperoxia-induced photoreceptor loss was accompanied by reduction of metabolic marker, Cox Va, and increased expression of oxidative stress indicator, acrolein and Hmox-1. Pretreatment with 670 nm red light reduced expression of markers of oxidative stress and C3, and slowed, but did not prevent, photoreceptor loss over the time course of hyperoxia exposure.ConclusionThe damaging effects of hyperoxia on photoreceptors were ameliorated following pretreatment with 670 nm light in hyperoxic mouse retinas. These results suggest that pretreatment with 670 nm light may provide stability to photoreceptors in conditions of oxidative stress.

Aging retinal function is improved by near infrared light (670 nm) that is associated with corrected mitochondrial decline

“…This mirrors findings where 670 nm light has been used to protect against light induced photoreceptor degeneration, significant protection was afforded, but this did not provide complete protection (Albarracin et al., 2011). However, ERGs are relatively crude, and are thought to be about 2 log units less sensitive than psychophysical responses (Ruseckaite et al., 2011).…”

Targeting Neurovascular Interaction in Retinal Disorders

“…Clinically, it has shown promise in aiding wound healing [207], neurological neck pain [208], chronic joint disorders [208], peripheral nerve recovery [209], stroke recovery [210], and traumatic brain injury [211]. Photobiomodulation has also gained interest for the treatment of retinal disorders, having had positive effects in several mouse retinopathy models such as in light induced injury [212,213], OIR [214,215], streptozotocin-induced diabetes [216], methanol induced degeneration [217], and a model of complement factor H related degeneration [218]. These promising results have led to clinical trials in humans with AMD.…”

Retinal pigment epithelium in the pathogenesis of age‐related macular degeneration and photobiomodulation as a potential therapy?

“…154 More recently, focus has turned to the potential beneficial effects of photobiomodulation as a treatment for blinding retinal diseases. Treatment effects from photobiomodulation has been demonstrated in various retinal disease animal models including light-induced retinal degeneration, 155,156 AMD, 157 retinitis pigmentosa, 158 diabetic retinopathy 159 and retinopathy of prematurity 160,161 as evidenced by improved ERG, decreased inflammatory markers and diminished cell loss.…”