Data-Independent Acquisition Mass Spectrometry Measurement of Protein Networks in the Aging Human Lens and Lens Influx Pathways

Abstract

The ocular lens is responsible for focusing of light onto the retina and must maintain transparency to effectively transmit light. Age related nuclear cataract is the most common cause of blindness worldwide, and cataract opacification of the lens is a currently unavoidable consequence of human and mammalian aging. To prevent accumulation of oxidative stress and subsequent aggregation, the lens proteome is densely populated by small heat-shock protein -crystallin, but it is hypothesized that antioxidants and other nutrients are delivered to the lens core through a microcirculatory system comprised of lower abundance lens proteins that support influx to the lens nucleus through sutures on the polar axis, and efflux through the lens equator. Since human lenses unavoidably experience cataract formation with age, it is critical to measure which protein networks contribute to and are affected by process of aging in an effort to molecularly characterize age-related cataract formation. This research approach pairs high-sensitivity proteomics methods to characterize how lens protein networks are changed as a function of cellular age and human age in addition to a sensitive measurement of influx networks along the suture with respect to cellular age. This work resulted in the identification of proteins and protein networks that are disrupted by the aging process, particularly as it is related to calcium accumulation, and the transport of antioxidants, metabolites, and their waste products.