Cockayne syndrome mice reflect human kidney disease and are defective in de novo NAD biosynthesis

Cockayne Syndrome (CS) is a multi-system premature aging disorder caused by mutations in the genes involved in repairing DNA damage. CS patients display features including short stature, microcephaly, premature aging, neurodegeneration, photosensitivity, vision impairment, hearing loss, and bone and kidney abnormalities. Intracellular nicotinamide dinucleotide (NAD+) deprivation is one of the key molecular characteristics of CS patient-derived cells. NAD+ has critical roles in regulating cellular health, stress responses, and is important for maintaining renal homeostasis. While kidney dysfunction has been reported to be an important cause of death in CS patients, the molecular pathogenesis and potential linkage to NAD+ is not understood. In this study, we report kidney pathology in CS model mice, including renal atrophy, decreased glomerular filtration, and various types of lesions centering around the tubular epithelial cells. We further find that the NAD+ biosynthetic pathways are impaired in CS kidney from mice and in human cells.