Energy Shortage in Human and Mouse Models ofSLC4A11-Associated Corneal Endothelial Dystrophies

P urpose To elucidate the molecular events in solute carrier family 4 member 11 (SLC4A11)-deficient corneal endothelium that lead to the endothelial dysfunction that characterizes the dystrophies associated with SLC4A11 mutations, congenital hereditary endothelial dystrophy (CHED) and Fuchs endothelial corneal dystrophy 4. M ethods Comparative transcriptomic analysis (CTA) was performed in primary human corneal endothelial cells (pHCEnC) and murine corneal endothelial cells (MCEnC) with normal and reduced levels of SLC4A11 ( SLC4A11 KD pHCEnC) and Slc4a11 ( Slc4a11 −/− MCEnC), respectively. Validation of differentially expressed genes was performed using immunofluorescence staining of CHED corneal endothelium, as well as western blot and quantitative PCR analysis of SLC4A11 KD pHCEnC and Slc4a11 −/− MCEnC. Functional analyses were performed to investigate potential functional changes associated with the observed transcriptomic alterations. R esults CTA revealed inhibition of cell metabolism and ion transport function as well as mitochondrial dysfunction, leading to reduced adenosine triphosphate (ATP) production, in SLC4A11 KD pHCEnC and Slc4a11 −/− MCEnC. Co-localization of SNARE protein STX17 with mitochondria marker COX4 was observed in CHED corneal endothelium, as was activation of AMPK–p53/ULK1 in both SLC4A11 KD pHCEnC and Slc4a11 −/− MCEnC, providing additional evidence of mitochondrial dysfunction and mitophagy. Reduced Na + -dependent HCO 3 − transport activity and altered NH 4 Cl-induced membrane potential changes were observed in Slc4a11 −/− MCEnC. C onclusions Reduced steady-state ATP levels and subsequent activation of the AMPK–p53 pathway provide a link between the metabolic functional deficit and transcriptome alterations, as well as evidence of insufficient ATP to maintain the Na + /K + -ATPase corneal endothelial pump as the cause of the edema that characterizes SLC4A11 -associated corneal endothelial dystrophies.