Combined thermal and mild electrical stimulations modulate heat shock protein and VEGF in retinal pigment epithelial cells under high glucose.

OBJECTIVE

Macular laser for diabetic macular edema (DME) is known to increase heat shock protein (HSP) expression in retinal pigment epithelial (RPE) cells, and increased HSP expression may be a mechanism for improving macular edema. Furthermore, the effectiveness of mild electrical stimulation (MES) as a cofactor in further enhancing HSP expression by thermal stimulation has been reported. In the current study, the effect of this combination treatment was examined in an in vitro HG (high glucose) + DFX (deferoxamine mesylate salt) model that simulates DME using a human RPE cell line (ARPE-19).

RESULTS

Combined thermal stimulation and MES significantly increased HSP70 expression in both the control and HG + DFX model groups, while suppressing VEGF and inflammatory cytokine levels in HG + DFX model. The combined treatment also showed a protective effect on the blood-retinal barrier integrity, although transient, as measured by TEER. These findings suggest that combined thermal stimulation and MES represent a promising therapeutic approach for managing DME, by modulating HSP and VEGF expression and potentially reducing inflammation and promoting protective mechanisms in the retina.