BODIPY‐Cholesterol: A New Tool to Visualize Sterol Trafficking in Living Cells and Organisms

Abstract

Analysis of sterol distribution and transport in living cells has been hampered by the lack of bright, photostable fluorescent sterol derivatives that closely resemble cholesterol. In this study, we employed atomistic simulations and experiments to characterize a cholesterol compound with fluorescent boron dipyrromethene difluoride linked to sterol carbon-24 (BODIPY-cholesterol). This probe packed in the membrane and behaved similarly to cholesterol both in normal and in cholesterol-storage disease cells and with trace amounts allowed the visualization of sterol movement in living systems. Upon injection into the yolk sac, BODIPYcholesterol did not disturb zebrafish development and was targeted to sterol-enriched brain regions in live fish. We conclude that this new probe closely mimics the membrane partitioning and trafficking of cholesterol and, because of its excellent fluorescent properties, enables the direct monitoring of sterol movement by time-lapse imaging using trace amounts of the probe. This is, to our knowledge, the first cholesterol probe that fulfills these prerequisites.

Recent Developments in the Study of the Behavior of Fluorescent Membrane Probes in Lipid Bilayers: Molecular Dynamics Approach

“…This behavior is at odds with the well-known orientation of cholesterol, with the hydroxyl group towards the interface, and the long axis approximately perpendicular to the bilayer plane (Franks, 1976;Worcester & Franks, 1976). Therefore, this study seems to confirm that both 22-and 25-NBD-cholesterol are inappropriate cholesterol analogs, probably at variance with BODIPY-cholesterol (see section further ahead), whose orientation in the bilayer resembles that of cholesterol (Hölttä-Vuori et al, 2008). …”

“…1G) was found to partition into ordered domains in model membranes (Shaw et al, 2006). A recent work using BODIPY-cholesterol combined live cell imaging (which established that the probe closely mimics the membrane partitioning and trafficking of cholesterol) with MD simulations (Hölttä-Vuori et al, 2008). Focusing on the latter, systems with both DPPC and N-palmitoylsphingomyelin (SM) at T=323 K, were simulated for a duration of ≥60 ns in each case.…”

Influence of the sterol aliphatic side chain on membrane properties: a molecular dynamics study

“…lanosterol, desmosterol, and 7-dehydrocholesterol), with modified polar group and methyl substitution, and reiterated the role of sterol tilt as a key parameter regarding its effect on lipid membranes. An inverse relationship between y and the ordering effects of a given sterol has been verified in subsequent studies, for diverse molecules such as intrinsically 13,14 or extrinsically 15,16 fluorescent sterols, 25-hydroxycholesterol, 17 cholesteryl hemisuccinate, 18 or b-sitosterol. 19 While a direct relationship between sterol tilt and ordering capability appears to be clear, it should be recognized that the tilt itself depends on the sterol structure, and numerous types of chemical modifications affect sterol orientation within membranes, 20 as evident from the above examples.…”

LTP-triggered cholesterol redistribution activates Cdc42 and drives AMPA receptor synaptic delivery

“…Bodipy-cholesterol was injected in hippocampal slices in closed proximity to CA1 neurons 24 h before the experiment. This long incubation time allows labeled cholesterol to equilibrate with the endogenous cholesterol of neurons and reach intracellular membranes (Hölttä-Vuori et al, 2008). Under these conditions, Bodipy-cholesterol was mostly observed in what appeared to be intracellular compartments ( Fig.…”

“…To try and visualize this effect, and also to monitor cholesterol content specifically in neurons, we performed imaging experiments using Bodipy-labeled cholesterol (Hölttä-Vuori et al, 2008;Marks et al, 2008). Bodipy-cholesterol was injected in hippocampal slices in closed proximity to CA1 neurons 24 h before the experiment.…”