Rubicon, a Key Molecule for Oxidative Stress-Mediated DNA Damage, in Ovarian Granulosa Cells

Aging increases oxidative stress (OS) in the ovaries, leading to infertility-related dis-orders. Granulosa cells (GCs), which support folliculogenesis in the ovaries, are chron-ically exposed to excessive OS under pathological conditions. Here, we demonstrate the significant role of Rubicon, an autophagy suppressor, as a DNA damage mediator in GCs under OS. Hydrogen peroxide (H2O2) decreased cell viability in the human GC cell line, HGrC1, due to DNA damage, without affecting autophagic activity. However, activation of autophagy increased OS resistance in HGrC1 cells, and vice versa. Among several materials that are considered safer for clinical use, trehalose, a disaccharide, exerted a protective effect as an autophagy activator against H2O2-induced cytotoxici-ty. Trehalose significantly increased autophagic activity, accompanied by a reduction in Rubicon, compared to other carbohydrates. It also reduced the expression of DNA damage-responsive proteins and the production of reactive oxygen species. The reduc-tion in Rubicon expression by siRNA mitigated DNA damage caused by OS, while overexpression of Rubicon enhanced DNA damage and decreased HGrC1 cell viability. Trehalose enhanced OS resistance by activating autophagy and suppressing Rubicon in a bidirectional manner. As Rubicon expression increases in aged human ovaries, tre-halose may improve ovarian function in patients with infertility and other OS-related diseases.