Hyaluronan synthesis by developing cortical neurons in vitro

Abstract

Hyaluronan is a linear glycosaminoglycan that forms the backbone of perineuronal nets around neurons in the cerebral cortex. However, it remains controversial whether neurons are capable of independent hyaluronan synthesis. Herein, we examined the expression of hyaluronan and hyaluronan synthases (HASs) throughout cortical neuron development in vitro. Enriched cultures of cortical neurons were established from E16 rats. Neurons were collected at days in vitro (DIV) 0 (4 h), 1, 3, 7, 14, and 21 for qPCR or immunocytochemistry. In the relative absence of glia, neurons exhibited HAS1–3 mRNA at all time-points. By immunocytochemistry, puncta of HAS2–3 protein and hyaluronan were located on neuronal cell bodies, neurites, and lamellipodia/growth cones from as early as 4 h in culture. As neurons matured, hyaluronan was also detected on dendrites, filopodia, and axons, and around synapses. Percentages of hyaluronan-positive neurons increased with culture time to ~93% by DIV21, while only half of neurons at DIV21 expressed the perineuronal net marker Wisteria floribunda agglutinin. These data clearly demonstrate that neurons in vitro can independently synthesise hyaluronan throughout all maturational stages, and that hyaluronan production is not limited to neurons expressing perineuronal nets. The specific structural localisation of hyaluronan suggests potential roles in neuronal development and function.

Keratan sulfate (KS)‐proteoglycans and neuronal regulation in health and disease: the importance ofKS‐glycodynamics and interactive capability with neuroregulatory ligands

“…; Fowke et al . ). The depolarization of the neural plasma membrane by HA represents a novel signal transduction pathway (Hagenfeld et al .…”

A Photoresponsive Hyaluronan Hydrogel Nanocomposite for Dynamic Macrophage Immunomodulation

“…Hyaluronan (HA) is one example of a native ECM composite found in human tissue, and its accumulation and turnover has been implicated to modulate inflammatory responses of macrophages in physiological and pathological conditions . HA's structural and biological properties are important to mediate cell signaling during stages of development, disease, or tissue repair . The increase of HA deposition into sites of tissue injury and during inflammatory diseases inspired incorporating HA as a building block ECM protein in 3D hydrogels for immunomodulation in regenerative medicine .…”

The Role of Brain Microvascular Endothelial Cell and Blood-Brain Barrier Dysfunction in Schizophrenia

“…BMEC and pericytes produce ECM components such as collagen type IV (COL4A), fibronectin (FN), laminin 1 (LAMA1), and LAMA2 [17,101], while astrocytes provide additional support by secreting LAMA1, LAMA2, and nidogen (NID1) [17]. Other ECM components include reelin, chondroitin sulfate proteoglycans, hyaluronic acid (HA), and heparan sulfate proteoglycans perlecan (HSPG2) and agrin (AGRN), which have surface receptors that sequester and interact with growth factors [100][101][102][103]. Heparan sulfate proteoglycans are metabolized by N-deacetylase/N-sulfotransferase 3 (NDST3), a brain enzyme involved in leukocyte adhesion at the BBB [13,104].…”