Structural Patterns of Rhamnogalacturonans Modulating Hsp-27 Expression in Cultured Human Keratinocytes

Abstract

Polysaccharide extracts were obtained from chestnut bran (Castanea sativa), grape marc (Vitis vinifera) and apple marc (Malus spp.) and fractionated by size exclusion chromatography after endopolygalacturonase degradation. Compositional and linkage analyses by GC and GC-MS showed the characteristic rhamnogalacturonan structure with specific arabinan (apple marc) and type II arabinogalactan (chestnut bran, grape marc) side chains. Type II arabinogalactan rhamnogalacturonan from chestnut bran significantly stimulated the in vitro differentiation of human keratinocytes, giving evidence of a tight structure-function relationship. This molecule comprises short and ramified 3- and 3,6-β-d-galactan and 5- and 3,5-α-l-arabinan side chains, but also contains significant amounts of t‑Xyl and 4‑Xyl with a characteristic 2:1 ratio. Enzymatic hydrolysis of this polysaccharide produced fragments of lower molecular weight with unchanged xylose content which conserved the same ability to stimulate human keratinocyte differentiation. It could be then speculated that dimeric xylosyl-xylose and/or longer oligomeric xylose side chains attached to a galacturonan and closely associated to hairy rhamno-galacturonan domains are essential patterns that could determine the biological activity of pectins.

Pectic substances: From simple pectic polysaccharides to complex pectins—A new hypothetical model

“…XGAs are generally susceptible to Exo-PGs, but seldom degraded by Endo-PGs, though an Endo-PG has recently been found to accommodate a xylosylated GalA residue of the backbone just following the hydrolysis site (Mort, Zheng, Qiu, Nimtz, & Bell-Eunice, 2008). Some other reported sources of XGAs are tragacanthic acid (of gum tragacanth from Astralgus gummifer, Leguminosae), kidney and red bean cotyledons, Japanese radish, pea hulls, onion bulbs, cotton seeds, potato tubers, chestnut bran, and grape, pear, apple, citrus and yellow passion fruit rinds (Cui, 2005;Gloaguen et al, 2008;Yapo, 2007Yapo, , 2009a. XGAs are usually found in storage tissues of reproductive organs, and therefore may have specialised functions in these tissues (Albersheim et al, 1996), though they have been identified in non-reproductive organs (roots, stems, and leaves) of diverse plants (Pilarska, Czaplicki, & Konieczny, 2007;Xia, Liu, Zhang, & Luo, 2008;Zandleven et al, 2007), thus suggesting a larger array of functionalities.…”

Arabinogalactans from Mimosa tenuiflora (Willd.) Poiret bark as active principles for wound-healing properties: Specific enhancement of dermal fibroblast activity and minor influence on HaCaT keratinocytes

“…Strongly stimulating effects of plant polysaccharides on human skin cell physiology have been shown for several times in the recent 0378 (Gloaguen et al, 2008;Deters et al, 2005a,b;Brunold et al, 2004). Especially the strong enhancement of cell viability and proliferation rates in human skin fibroblasts and keratinocytes suggest a positive impact of certain carbohydrates on the regeneration after skin lesions.…”