Impact of Glycans on Lipid Membrane Dynamics at the Nanoscale Unveiled by Planar Plasmonic Nanogap Antennas and Atomic Force Spectroscopy

Abstract

Lateral compartmentalization of the plasma membrane is a prominent feature present at multiple spatiotemporal scales that regulates key cellular functions. The extracellular glycocalyx matrix has recently emerged as an important player that modulates the organization of specific receptors and patterns the lipid bilayer itself. However, experimental limitations in investigating its impact on the membrane nanoscale dynamics have hampered detailed studies. Here, we used photonic nanoantenna arrays combined with fluorescence correlation spectroscopy to investigate the influence of hyaluronic acid (HA), a prominent glycosaminoglycan, on the nanoscale organization of mimetic lipid bilayers. Using atomic force microscopy and force spectroscopy, we further correlated our dynamic measurements with the morphology and mechanical properties of bilayers at the nanoscale. Overall, we find that HA has a profound effect on the dynamics, nanoscale organization, and mechanical properties of lipid bilayers that are enriched in sphingolipids and/or cholesterol, such as those present in living cells.

The Sentient Cell: Implications for Osteopathic Medicine

“…Another model that follows the previous one is the membrane nanodomains (MND) (lipid microdomains or lipid rafts), which explains cellular behavior with the presence of lipids inside the membrane. Cholesterol and sphingomyelin molecules (lipid rafts) allow the membrane to be maintained in a state of fluidity, albeit in a mechanistic manner [11,16]. The cell is understood as a compartmentalization, where each molecule responds in a mirror-like manner to the biochemical information it receives [16].…”

“…Cholesterol and sphingomyelin molecules (lipid rafts) allow the membrane to be maintained in a state of fluidity, albeit in a mechanistic manner [11,16]. The cell is understood as a compartmentalization, where each molecule responds in a mirror-like manner to the biochemical information it receives [16].…”

Correlative nanophotonic approaches to enlighten the nanoscale dynamics of living cell membranes

“…The large-scale availability of planar nanogap antenna arrays facilitate their implementation for live-cell imaging including the adaptation of established biological sample preparation protocols. Additionally, these types of platforms accommodate gap sizes between 10 to 50 nm which have been exploited to perform so-called ‘spot-variation FCS' [ 114 ] at the nanoscale [ 18 , 113 , 115 , 116 ], at scales significantly smaller than possible with sSTED-FCS [ 50 ] or ZMWs [ 117 , 118 ]. Moreover, a planar nanoantenna platform can be readily combined with other techniques to increase the information content of the sample under study.…”

“…Moreover, a planar nanoantenna platform can be readily combined with other techniques to increase the information content of the sample under study. For instance, correlative studies of antenna-FCS and atomic force microscopy (AFM) and spectroscopy permitted to resolve the influence of hyaluronic acid, an abundant ECM component, on the nanoscale lipid organization of model lipid membranes [ 115 ]. This shows the potential to use the planar nanogap antennas for correlative measurements, albeit requiring substrate optimization.…”

Host Cell Response to Rotavirus Infection with Emphasis on Virus–Glycan Interactions, Cholesterol Metabolism, and Innate Immunity

“…In addition to the presence of receptors for RVA entry/attachment, some components of the plasma membrane, such as cholesterol, have been demonstrated to play a critical role in RVA replication [ 22 , 23 ]. Moreover, there is strong evidence that cellular glycans can directly bind cholesterol and alter lipid membrane dynamics and organization [ 24 , 25 ]. This suggests that differential interactions with host glycans are likely to be associated with variable effects of RVAs on cholesterol/lipid metabolism.…”