Maternal high-fructose diet induced early-onset retinopathy via the suppression of synaptic plasticity mediated by mitochondrial dysfunction.

Retinopathy is a leading cause of blindness, and there is currently no cure. Earlier identification of the progression of retinopathy could provide a better chance for intervention. Diet has profound effects on retinal function. A maternal high-fructose diet (HFD) triggers diseases in multiple organs. However, whether maternal HFD impairs retinal function in adult offspring is currently unknown. By using the rodent model of maternal HFD during pregnancy and lactation, our data indicated a reduced b-wave of electroretinography (ERG) in HFD female offspring at 3 mo of age compared with age-matched offspring of dams fed regular chow (ND). Immunofluorescence and Western blot analyses indicated that the distributions and expressions of synaptophysin, postsynaptic density protein 95 (PSD95), and phospho(p)-Ca/calmodulin-stimulated protein kinase IIα (CaMKIIα) were significantly suppressed in the HFD group. Furthermore, the ATP content and the mitochondrial respiratory protein, Mt CPX 4-2, were decreased. Moreover, the expressions of peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and mitochondrial transcription factor A (TFAM) in the retina of the HFD group were downregulated. Treatment with coenzyme Q (Q10), a key mediator of the electron transport chain, effectively reversed these abovementioned dysfunctions. Together, these results suggested that maternal HFD impaired retinal function in adult female offspring. The mechanism underlying early-onset retinopathy may involve the reduction in the capacity of mitochondrial energy production and the suppression of synaptic plasticity. Most importantly, mitochondria could be a feasible target to reprogram maternal HFD-damaged retinal function. In this study, we provide novel evidence that maternal high-fructose diet during gestation and lactation could induce early-onset retinopathy in adult female offspring. Of note, the insufficient energy content, downregulated mitochondrial respiratory complex 4-2, and impaired mitochondrial biogenesis might contribute to the decrease of synaptic plasticity resulting in retinal function suppression. Oral application with coenzyme Q for 4 wk could at least partially reverse the aforementioned molecular events and retinal function.