title: Determination of hyaluronan molecular mass distribution in human breast milk.
abstract: Hyaluronan (HA) in human milk mediates host responses to microbial infection via TLR4- and CD44-dependent signaling. Signaling by HA is generally size specific. Because pure HA with average molecular mass (M) of 35 kDa can elicit a protective response in intestinal epithelial cells, it has been proposed that human milk HA may have a bioactive low-M component. Here we report the size distribution of HA in human milk samples from 20 unique donors. A new method for HA analysis, employing ion exchange (IEX) chromatography to fractionate HA by size and specific quantification of each size fraction by competitive enzyme-linked sorbent assay (ELSA), was developed. When separated into four fractions, milk HA with M⩽20 kDa, M∼20 to 60 kDa, and M∼60 to 110 kDa comprised averages of 1.5, 1.4, and 2.0% of the total HA, respectively. The remaining 95% was HA with M⩾110 kDa. Electrophoretic analysis of the higher M HA from 13 samples showed nearly identical M distributions, with an average M of approximately 440 kDa. This higher M HA component in human milk is proposed to bind to CD44 and to enhance human beta defensin 2 (HBD2) induction by the low-M HA components.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Polytechnic School of Engineering, New York University, Brooklyn, NY 11201, USA.
authors.forename: Han
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Department of Chemical and Biomolecular Engineering, Polytechnic School of Engineering, New York University, Brooklyn, NY 11201, USA; Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Colorectal Surgery, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Ripal
authors.initials: R
authors.lastname: Amin
authors.affiliation: Department of Chemical and Biomolecular Engineering, Polytechnic School of Engineering, New York University, Brooklyn, NY 11201, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Colorectal Surgery, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: de la Motte
authors.affiliation: Department of Chemical and Biomolecular Engineering, Polytechnic School of Engineering, New York University, Brooklyn, NY 11201, USA. Electronic address: mary.cowman@nyu.edu.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Cowman
mesh_terms: D002138:Calibration; D005591:Chemical Fractionation; D003720:Densitometry; D004586:Electrophoresis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry* / Q000302:isolation & purification; D007474:Ion Exchange; D008895:Milk, Human / Q000737:chemistry*; D008970:Molecular Weight
chemical_list: D006820:Hyaluronic Acid
keywords: Electrophoresis; Hyaluronan; Ion exchange; Milk; Molecular mass; Quantification