TY - JOUR

T1 - Optical properties of the human lens constituents

AU - Zelentsova, Ekaterina A.

AU - Yanshole, Lyudmila V.

AU - Fursova, Anjella Zh

AU - Tsentalovich, Yuri P.

N1 - Copyright © 2017 Elsevier B.V. All rights reserved.

PY - 2017/8/1

Y1 - 2017/8/1

N2 - The absorption and fluorescence properties of the metabolomic (MET), water-soluble and urea-soluble protein fractions from the middle-age, aged, and cataractous human lenses have been measured. At 280 nm and 300 nm the major lens absorbers are crystallins, which absorb more than 90% of light in the UV-B region (280–315 nm). In middle-aged lenses, the absorption at 360 nm is mostly provided by UV filters contained in the MET fraction. With aging, and especially with the cataract development, the absorption of MET fraction in UV-A region (315–400 nm) decreases due to the drop of the UV filter concentration, while the absorption of protein fractions increases due to the accumulation of post-translational modifications. Consequently, the contribution of the MET fraction into the total lens absorption at 360 nm decays from 63% in middle-aged lenses to 25% in aged lenses to 3% in cataractous lenses. The fluorescence yield of the MET fraction from cataractous lenses also significantly increases. Therefore, the protection of the lens tissue against UV radiation in aged and cataractous lenses weakens: the absorption of UV-A light is mostly provided by modified crystallins and non-UV-filter metabolites, which are photochemically more active than the UV filters. The obtained data indicate that the aged and cataractous human lenses are more vulnerable to UV-A light than the middle-aged lenses.

AB - The absorption and fluorescence properties of the metabolomic (MET), water-soluble and urea-soluble protein fractions from the middle-age, aged, and cataractous human lenses have been measured. At 280 nm and 300 nm the major lens absorbers are crystallins, which absorb more than 90% of light in the UV-B region (280–315 nm). In middle-aged lenses, the absorption at 360 nm is mostly provided by UV filters contained in the MET fraction. With aging, and especially with the cataract development, the absorption of MET fraction in UV-A region (315–400 nm) decreases due to the drop of the UV filter concentration, while the absorption of protein fractions increases due to the accumulation of post-translational modifications. Consequently, the contribution of the MET fraction into the total lens absorption at 360 nm decays from 63% in middle-aged lenses to 25% in aged lenses to 3% in cataractous lenses. The fluorescence yield of the MET fraction from cataractous lenses also significantly increases. Therefore, the protection of the lens tissue against UV radiation in aged and cataractous lenses weakens: the absorption of UV-A light is mostly provided by modified crystallins and non-UV-filter metabolites, which are photochemically more active than the UV filters. The obtained data indicate that the aged and cataractous human lenses are more vulnerable to UV-A light than the middle-aged lenses.

KW - Absorption

KW - Cataract

KW - Fluorescence

KW - Human lens

KW - Aging/metabolism

KW - Humans

KW - Middle Aged

KW - Male

KW - Optical Phenomena

KW - Aged, 80 and over

KW - Cataract/metabolism

KW - Lens, Crystalline/metabolism

KW - Adult

KW - Female

KW - Aged

KW - Ultraviolet Rays/adverse effects

UR - http://www.scopus.com/inward/record.url?scp=85020750565&partnerID=8YFLogxK

U2 - 10.1016/j.jphotobiol.2017.06.005

DO - 10.1016/j.jphotobiol.2017.06.005

M3 - Article

C2 - 28624737

AN - SCOPUS:85020750565

VL - 173

SP - 318

EP - 324

JO - Journal of Photochemistry and Photobiology B: Biology

JF - Journal of Photochemistry and Photobiology B: Biology

SN - 1011-1344

ER -