Enzymatic removal of hyaluronan affects routing of axons in the mouse optic chiasm

Abstract

Perturbations of interaction of hyaluronan (HA) with its receptor CD44 cause multiple errors in axon routing at the mouse optic chiasm. To investigate this interaction further on the chiasm routing, we studied the axon routing after enzymatic removal of HA from slice preparations of the optic pathway. Hyaluronidase treatment produced an obvious reduction in midline crossing of the first generated axons in E13 chiasms, but had no influence on routing ofthe uncrossed axons in E15 and E16 slices. These findings support a direct role of HA, acting probably through CD44, on axon decussation during early phase of chiasm development, but argue against a direct function of HA on the turning of uncrossed axons in the mouse optic chiasm.

Hyaluronan synthesis by developing cortical neurons in vitro

“…‘Axonal coats’ of aggrecan are also present in various human basal ganglia regions60, in the human lateral geniculate body61, and in the rat thalamus62, often independently of perineuronal nets. Interestingly, there is evidence that hyaluronan can control axonal outgrowth of optic tract and locus ceruleus neurons636465. Further, removal of hyaluronan promotes regeneration of severed axons in the rat brain66, although addition of low molecular weight hyaluronan oligosaccharides enhances axonal regrowth following spinal cord injury67.…”

Calcite Biohybrids as Microenvironment for Stem Cells

“…In the tissue engineering field, HA has been utilized to repair defects of the skin or of the musculoskeletal system, including cartilage, bone, ligament, and intervertebral discs [28][29][30][31][32][33]. To decrease it's in vitro and in vivo degradation rates, HA usually undergoes chemical modification before being used in tissue engineering [34][35][36][37].…”

Axon guidance and neuronal migration research in China

“…These proteoglycans include sulphated molecules chondroitin sulphate proteoglycans (CS-PGs) and heparan sulfate proteoglycans (HS-PGs), a type of nonsulfated linear glycosaminoglycan hyaluronan (HA), and the cell surface carbohydrate molecule SSEA-1, which is also known as CD15 (leukocyte cluster of differentiation 15) and Lewis-x, a member of the Lewis blood group antigens in humans [24]. By immunohistochemisty using antibodies specific for different glycan epitopes and antibodies against carrier proteins of glycans, they observed specific expression of each of these proteoglycans along the retinofugal pathway [11,13,14,17,19,20,22]. They found that cell adhesion molecules that may recognize these proteoglycans [25,26], including L1, the poly-sialylated form of NCAM (PSA-NCAM) and CD44, are also expressed in a site-specific pattern along the optic pathway at comparable developmental stages [15,16], consistent with the previous reports [27,28].…”

“…The potential contributions of glycan molecules present in developing brain tissues have long been overlooked. Chan SunOn and colleagues [10][11][12][13][14][15][16][17][18][19][20][21][22][23] explored the potential role of a group of proteoglycans expressed in the ventral diencephalon and in retina, in the routing and organization of optic fibers at the chiasm. These proteoglycans include sulphated molecules chondroitin sulphate proteoglycans (CS-PGs) and heparan sulfate proteoglycans (HS-PGs), a type of nonsulfated linear glycosaminoglycan hyaluronan (HA), and the cell surface carbohydrate molecule SSEA-1, which is also known as CD15 (leukocyte cluster of differentiation 15) and Lewis-x, a member of the Lewis blood group antigens in humans [24].…”

“…In the slice culture preparation of retinofugal projections, specific enzymatic digestion of the CS or HA sugar epitopes from the ventral diencephalon tissue dramatically perturbed the midline choices and chronic organization of optic fibers [12,20]. Interestingly, the treatment with specific antibodies [15], which disturb the interaction between HA and CD44, or the treatment with exogenous HA [21], which probably displaces the endogenous HA from binding to CD44, also produced similar defects in midline crossing of retinal axons as the enzymatic removal of HA [21].…”