Evidence for structural changes in dermatan sulfate and hyaluronic acid with aging

Three dermatan sulfates (DS18, DS28, and DS35) were isolated from women's skin of ages 19 +/- 2.5, 35 +/- 3.5, 47 +/- 1.7, 60 +/- 0.8, and 75 +/- 5 years. They sequentially precipitated with 18, 28, and 35% ethanol. Their sulfate content was: 23.5, 25.3, and 29.0% (w/w) for DS18 at ages 19-35, 47, and 60 years, respectively; 29.0, 24.0, and 18.8% for DS28; and 18.0, 20.0, and 20.6% for DS35 at ages 19-47, 60, and 75 years, respectively. Both DS18 and DS28 decreased, respectively, from 0.030% (of wet-skin weight) to traces at age 75, and from 0.020 to 0.010% at 60 years. At age 75, DS28 apparently increased by 30%. The DS35 values (traces-0.006%) had no age-related trend. Hyaluronic acid (HA) precipitated with 45% ethanol, was 0.030% of skin-weight at ages 19-47, and decreased to 0.015 and 0.007% at 60 and 75 years, respectively. Its electrophoretic mobility was slower at age 47. In the oldest group, i.r. spectra of HA and DS35 displayed no bands at 1650-1600, 1380, and 1320 cm-1, and a new band at 1560 cm-1. Moreover, ninhydrin-positive material of HA and DS35 increased by 75 and 95%, respectively, and the reducing GlcNAc content of HA decreased. These data showed three chemically different dermatan sulfates (two of which were preponderant) and N-deacetylation of HA and DS35 of the oldest group. After age 47, total DS and HA considerably decreased, DS18 and DS35 were oversulfated, and DS28 became undersulfated with aging.