Mineralized calcium in tooth enamel may be linked to drusen deposits.
This article was reviewed by Dinusha Rajapakse, PhD
A team of investigators at the National Eye Institute (NEI) has determined that a protein associated with deposition of mineralized calcium in tooth enamel may be related to drusen deposits in patients with dry age-related macular degeneration (AMD).
“The protein is amelotin, which seems to be specific to dry AMD, and may potentially prove to be a therapeutic target in the disease,” said Dinusha Rajapakse, PhD, the first author of the study and a visiting research fellow at the NEI, in Bethesda, MD, working in the laboratory of Graeme Wistow, PhD, chief of the NEI Section on Molecular Structure and Functional Genomics and senior investigator of the study cited in Translational Research.1
This finding may ultimately prove to be a boon for patients with dry AMD because, unlike wet AMD, there is currently no treatment available for the dry form of the disease.
Hydroxyapatite is a component of bone and tooth enamel. In their study, the investigators corroborated that hydroxyapatite, a calcium-rich mineral compound previously associated with AMD progression, is deposited in dry AMD.
Small spherules of hydroxyapatite filled with cholesterol were identified in drusen from patients with dry AMD.
In the study, when the retinal pigment epithelium (RPE) cells were starved of serum for 9 days, the investigators saw formation of amelotin deposits.
Dr. Rajapakse and colleagues reported that amelotin “was strongly upregulated after extended starvation and is responsible for the mineralization of [hydroxyapatite] in their cell culture model. Blocking this pathway in the RPE cell line also blocked the production of these drusen-like deposits.”
Translational Research 2020. doi: 10.1016/j.trsl.2020.02.007.