Evidence of Spaceflight-Induced Adverse Effects on Photoreceptors and Retinal Function in the Mouse Eye.
Xiao Wen MaoSeta StanboulyJacob HolleyMichael J PecautJames CrapoPublished in: International journal of molecular sciences (2023)
The goal of the present study was to characterize acute oxidative damage in ocular structure and retinal function after exposure to spaceflight, and to evaluate the efficacy of an antioxidant in reducing spaceflight-induced changes in the retina. Ten-week-old adult C57BL/6 male mice were flown aboard the ISS on Space-X 24 over 35 days, and returned to Earth alive. The mice received a weekly injection of a superoxide dismutase mimic, MnTnBuOE-2-PyP 5+ (BuOE), before launch and during their stay onboard the ISS. Ground control mice were maintained on Earth under identical environmental conditions. Before the launch, intraocular pressure (IOP) was measured using a handheld tonometer and retinal function was evaluated using electroretinogram (ERG). ERG signals were recorded when the mouse eye was under dark-adapted conditions in response to ultraviolet monochromatic light flashes. Within 20 h after splashdown, IOP and ERG assessments were repeated before euthanasia. There were significant increases in body weight for habitat control groups post-flight compared to pre-flight measurements. However, the body weights were similar among flight groups before launch and after splashdown. The IOP measurements were similar between pre- and post-flight groups with no significant differences between BuOE-treated and saline controls. Immunofluorescence evaluation showed increases in retinal oxidative stress and apoptotic cell death after spaceflight. BuOE treatment significantly decreased the level of the oxidative stress biomarker. ERG data showed that the average amplitudes of the a- and b-wave were significantly decreased (39% and 32% by spaceflight, respectively) compared to that of habitat ground controls. These data indicate that spaceflight conditions induce oxidative stress in the retina, which may lead to photoreceptor cell damage and retinal function impairment.
Keyphrases
- oxidative stress
- diabetic retinopathy
- optic nerve
- optical coherence tomography
- cell death
- diabetic rats
- body weight
- dna damage
- ischemia reperfusion injury
- climate change
- induced apoptosis
- electronic health record
- drug induced
- randomized controlled trial
- single cell
- big data
- hydrogen peroxide
- computed tomography
- metabolic syndrome
- magnetic resonance
- intensive care unit
- endothelial cells
- cell therapy
- signaling pathway
- acute respiratory distress syndrome
- image quality
- heat shock
- smoking cessation
- type diabetes
- extracorporeal membrane oxygenation
- nitric oxide
- skeletal muscle